imgui-luau/build/imgui_love.lua

-- GENERATED by tools/bundle.py --target love - do not edit
local ffi = require("ffi")
local floor = math.floor
-- Luau standard library pieces the port uses, for LuaJIT (LÖVE). Prepended by `tools/bundle.py --target love` only:
-- the Roblox build uses Luau's native bit32/buffer/table/utf8 and never sees this file.

local bit = require("bit")
local TWO32 = 4294967296

-- bit32: unsigned 32-bit results like Luau/Lua 5.2 (LuaJIT's `bit` returns signed values)
if not bit32 then
    local band, bor, bxor, bnot, lshift, rshift, arshift, tobit = bit.band, bit.bor, bit.bxor, bit.bnot, bit.lshift, bit.rshift, bit.arshift, bit.tobit
    local function u(x) return x % TWO32 end
    local function t(x) return tobit(x % TWO32) end -- any number -> int32 (bit.* wraps doubles >= 2^31 unreliably)
    bit32 = {}
    function bit32.band(a, b, ...)
        if a == nil then return TWO32 - 1 end
        if b == nil then return u(t(a)) end
        local r = band(t(a), t(b))
        if ... ~= nil then for i = 1, select("#", ...) do r = band(r, t((select(i, ...)))) end end
        return u(r)
    end
    function bit32.bor(a, b, ...)
        if a == nil then return 0 end
        if b == nil then return u(t(a)) end
        local r = bor(t(a), t(b))
        if ... ~= nil then for i = 1, select("#", ...) do r = bor(r, t((select(i, ...)))) end end
        return u(r)
    end
    function bit32.bxor(a, b, ...)
        if a == nil then return 0 end
        if b == nil then return u(t(a)) end
        local r = bxor(t(a), t(b))
        if ... ~= nil then for i = 1, select("#", ...) do r = bxor(r, t((select(i, ...)))) end end
        return u(r)
    end
    function bit32.bnot(a) return u(bnot(t(a))) end
    function bit32.lshift(a, n) if n >= 32 or n <= -32 then return 0 end if n < 0 then return u(rshift(t(a), -n)) end return u(lshift(t(a), n)) end
    function bit32.rshift(a, n) if n >= 32 or n <= -32 then return 0 end if n < 0 then return u(lshift(t(a), -n)) end return u(rshift(t(a), n)) end
    function bit32.arshift(a, n) if n >= 32 then n = 31 end return u(arshift(t(a), n)) end
    function bit32.btest(...) return bit32.band(...) ~= 0 end
    function bit32.extract(n, field, width) width = width or 1; return u(band(rshift(t(n), field), 2 ^ width - 1)) end
end

-- buffer: fixed-size byte buffers (subset used by the port), on FFI memory. Little-endian like Luau.
if not buffer then
    ffi.cdef("void *memmove(void *dst, const void *src, size_t n); void *memset(void *s, int c, size_t n);")
    local C = ffi.C
    local u8p, u32p, f64p = ffi.typeof("uint8_t*"), ffi.typeof("uint32_t*"), ffi.typeof("double*")
    buffer = {}
    function buffer.create(n)
        local mem = ffi.new("uint8_t[?]", math.max(n, 1)) -- zero-filled
        return { p = ffi.cast(u8p, mem), n = n, mem = mem }
    end
    function buffer.len(b) return b.n end
    function buffer.readu8(b, o) return b.p[o] end
    function buffer.writeu8(b, o, v) b.p[o] = v end
    function buffer.readu32(b, o) return ffi.cast(u32p, b.p + o)[0] end
    function buffer.writeu32(b, o, v) ffi.cast(u32p, b.p + o)[0] = v % TWO32 end
    function buffer.readf64(b, o) return ffi.cast(f64p, b.p + o)[0] end
    function buffer.writef64(b, o, v) ffi.cast(f64p, b.p + o)[0] = v end
    function buffer.readstring(b, o, n) return ffi.string(b.p + o, n) end
    function buffer.writestring(b, o, s, n) ffi.copy(b.p + o, s, n or #s) end
    function buffer.copy(dst, doff, src, soff, n)
        soff = soff or 0
        n = n or (src.n - soff)
        if n > 0 then C.memmove(dst.p + doff, src.p + soff, n) end
    end
    function buffer.fill(b, o, v, n) n = n or (b.n - o); if n > 0 then C.memset(b.p + o, v, n) end end
    function buffer.tostring(b) return ffi.string(b.p, b.n) end
    function buffer.fromstring(s) local b = buffer.create(#s); ffi.copy(b.p, s, #s); return b end
end

-- table / math / utf8 additions from Luau / Lua 5.3
do
    local ok, clear = pcall(require, "table.clear")
    table.clear = table.clear or (ok and clear) or function(t) for k in pairs(t) do t[k] = nil end end
    table.unpack = table.unpack or unpack
    table.find = table.find or function(t, v, init) for i = init or 1, #t do if t[i] == v then return i end end end
    table.move = table.move or function(a1, f, e, t, a2)
        a2 = a2 or a1
        if e >= f then
            if t > f or t > e or a1 ~= a2 then for i = 0, e - f do a2[t + i] = a1[f + i] end
            else for i = e - f, 0, -1 do a2[t + i] = a1[f + i] end end
        end
        return a2
    end
    math.pow = math.pow or function(a, b) return a ^ b end
end

if not utf8 then
    utf8 = { charpattern = "[\0-\x7F\xC2-\xFD][\x80-\xBF]*" }
    function utf8.char(...)
        local out = {}
        for i = 1, select("#", ...) do
            local c = select(i, ...)
            if c < 0x80 then out[#out + 1] = string.char(c)
            elseif c < 0x800 then out[#out + 1] = string.char(0xC0 + floor(c / 64), 0x80 + c % 64)
            elseif c < 0x10000 then out[#out + 1] = string.char(0xE0 + floor(c / 4096), 0x80 + floor(c / 64) % 64, 0x80 + c % 64)
            else out[#out + 1] = string.char(0xF0 + floor(c / 262144), 0x80 + floor(c / 4096) % 64, 0x80 + floor(c / 64) % 64, 0x80 + c % 64) end
        end
        return table.concat(out)
    end
    local function decode(s, i)
        local c = s:byte(i)
        if not c then return nil end
        if c < 0x80 then return c, 1 end
        if c < 0xE0 then return (c % 32) * 64 + s:byte(i + 1) % 64, 2 end
        if c < 0xF0 then return (c % 16) * 4096 + (s:byte(i + 1) % 64) * 64 + s:byte(i + 2) % 64, 3 end
        return (c % 8) * 262144 + (s:byte(i + 1) % 64) * 4096 + (s:byte(i + 2) % 64) * 64 + s:byte(i + 3) % 64, 4
    end
    function utf8.codes(s)
        local i = 1
        return function()
            if i > #s then return nil end
            local c, n = decode(s, i)
            local p = i; i = i + n
            return p, c
        end
    end
    function utf8.codepoint(s, i, j)
        i = i or 1; j = j or i
        local out = {}
        while i <= j do local c, n = decode(s, i); out[#out + 1] = c; i = i + n end
        return unpack(out)
    end
    function utf8.len(s) local n = 0; for _ in utf8.codes(s) do n = n + 1 end return n end
    function utf8.offset(s, n, i)
        i = i or (n >= 0 and 1 or #s + 1)
        if n > 0 then
            n = n - 1
            while n > 0 and i <= #s do i = i + 1; while i <= #s and s:byte(i) >= 0x80 and s:byte(i) < 0xC0 do i = i + 1 end; n = n - 1 end
            if n > 0 then return nil end
            return i
        end
        return i
    end
end


local __FILES, __LOADED = {}, {}
function IM_INCLUDE(name)
    local r = __LOADED[name]
    if r == nil then r = __FILES[name](); if r == nil then r = true end; __LOADED[name] = r end
    return r
end

__FILES['imgui.lua'] = function()
-- dear imgui, v1.93 WIP (Luau port)
-- (main code and documentation)

-- This file is a Lua/Luau port of Dear ImGui's imgui.cpp (docking branch, 1.93 WIP), following imgui.cpp function by function.
-- It runs on Roblox (Luau, primary target) and LÖVE (LuaJIT). Upstream documentation, examples and the demo apply almost directly.

-- Help:
-- - Call and read ImGui.ShowDemoWindow() in imgui_demo.lua. All applications in examples/ are doing that.
-- - Read top of imgui.lua for more details, links and comments.
-- - ImVec2 and ImVec4 have arithmetic metamethods (a + b, a * 2.0, etc.); fields are .x, .y (.z, .w).
-- - See README.md "Differences from C++ Dear ImGui" for the Luau conventions (out-params become return values, flags enums, text buffers).

-- Resources:
-- - FAQ ........................ https://dearimgui.com/faq (in upstream repository as docs/FAQ.md)
-- - Homepage ................... https://github.com/ocornut/imgui
-- - Releases & Changelog ....... https://github.com/ocornut/imgui/releases
-- - Gallery .................... https://github.com/ocornut/imgui/issues?q=label%3Agallery (please post your screenshots/video there!)
-- - Wiki ....................... https://github.com/ocornut/imgui/wiki (lots of good stuff there)
--   - Getting Started            https://github.com/ocornut/imgui/wiki/Getting-Started (how to integrate in an existing app by adding ~25 lines of code)
--   - Third-party Extensions     https://github.com/ocornut/imgui/wiki/Useful-Extensions (ImPlot & many more)
--   - Bindings/Backends          https://github.com/ocornut/imgui/wiki/Bindings (language bindings + backends for various tech/engines)
--   - Debug Tools                https://github.com/ocornut/imgui/wiki/Debug-Tools
--   - Glossary                   https://github.com/ocornut/imgui/wiki/Glossary
--   - Software using Dear ImGui  https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui
-- - Issues & support ........... https://github.com/ocornut/imgui/issues (upstream; for issues specific to this port, use this port's repository)
-- - Test Engine & Automation ... https://github.com/ocornut/imgui_test_engine (test suite, test engine to automate your apps)
-- - Web version of the Demo .... https://pthom.github.io/imgui_explorer (w/ source code browser)

-- Copyright (c) 2014-2026 Omar Cornut
-- Developed by Omar Cornut and every direct or indirect contributors to the GitHub.
-- See LICENSE.txt for copyright and licensing details (standard MIT License).
-- This library is free but needs your support to sustain development and maintenance.
-- Businesses: you can support continued development via B2B invoiced technical support, maintenance and sponsoring contracts.
-- PLEASE reach out at omar AT discohello DOT com. See https://github.com/ocornut/imgui/wiki/Funding
-- Businesses: you can also purchase licenses for the Dear ImGui Automation/Test Engine.
-- This port is unofficial and not affiliated with the Dear ImGui project; it is distributed under the same license.

-- It is recommended that you don't modify imgui.lua! It will become difficult for you to update the library.
-- Note that 'ImGui' being a plain table, you can add functions into it from your own source files, without
-- modifying imgui.lua. You may use the internal functions and data structures (imgui_internal.lua), but they don't
-- come with any guarantee of forward compatibility. Discussing your changes on the GitHub Issue Tracker may lead you
-- to a better solution or official support for them.

--
-- Index of this file:
--
-- DOCUMENTATION
--
-- - MISSION STATEMENT
-- - CONTROLS GUIDE
-- - PROGRAMMER GUIDE
--   - READ FIRST
--   - HOW TO UPDATE TO A NEWER VERSION OF DEAR IMGUI
--   - GETTING STARTED WITH INTEGRATING DEAR IMGUI IN YOUR CODE/ENGINE
--   - HOW A SIMPLE APPLICATION MAY LOOK LIKE
--   - USING CUSTOM BACKEND / CUSTOM ENGINE
-- - API BREAKING CHANGES (read me when you update!)
-- - FREQUENTLY ASKED QUESTIONS (FAQ)
--   - Read all answers online: https://www.dearimgui.com/faq, or in docs/FAQ.md (with a Markdown viewer)
--
-- CODE
-- (search for "[SECTION]" in the code to find them)
--
-- [SECTION] INCLUDES
-- [SECTION] FORWARD DECLARATIONS
-- [SECTION] CONTEXT AND MEMORY ALLOCATORS
-- [SECTION] USER FACING STRUCTURES (ImGuiStyle, ImGuiIO, ImGuiPlatformIO)
-- [SECTION] MISC HELPERS/UTILITIES (Geometry functions)
-- [SECTION] MISC HELPERS/UTILITIES (String, Format, Hash functions)
-- [SECTION] MISC HELPERS/UTILITIES (File functions)
-- [SECTION] MISC HELPERS/UTILITIES (ImText* functions)
-- [SECTION] MISC HELPERS/UTILITIES (Color functions)
-- [SECTION] ImGuiStorage
-- [SECTION] ImGuiTextFilter
-- [SECTION] ImGuiTextBuffer, ImGuiTextIndex
-- [SECTION] ImGuiListClipper
-- [SECTION] STYLING
-- [SECTION] RENDER HELPERS
-- [SECTION] INITIALIZATION, SHUTDOWN
-- [SECTION] MAIN CODE (most of the code! lots of stuff, needs tidying up!)
-- [SECTION] FONTS, TEXTURES
-- [SECTION] ID STACK
-- [SECTION] INPUTS
-- [SECTION] ERROR CHECKING, STATE RECOVERY
-- [SECTION] ITEM SUBMISSION
-- [SECTION] LAYOUT
-- [SECTION] SCROLLING
-- [SECTION] TOOLTIPS
-- [SECTION] POPUPS
-- [SECTION] WINDOW FOCUS
-- [SECTION] KEYBOARD/GAMEPAD NAVIGATION
-- [SECTION] DRAG AND DROP
-- [SECTION] LOGGING/CAPTURING
-- [SECTION] SETTINGS
-- [SECTION] LOCALIZATION
-- [SECTION] VIEWPORTS, PLATFORM WINDOWS
-- [SECTION] DOCKING
-- [SECTION] PLATFORM DEPENDENT HELPERS
-- [SECTION] METRICS/DEBUGGER WINDOW
-- [SECTION] DEBUG LOG WINDOW
-- [SECTION] OTHER DEBUG TOOLS (ITEM PICKER, ID STACK TOOL)
--
-- (In this port, the sections keep upstream's names but may appear in a different order:
--  e.g. DRAG AND DROP and DOCKING are near the top of imgui.lua. Some are partial or empty, see docs/TODO.txt.)
--

-------------------------------------------------------------------------------
-- DOCUMENTATION
-------------------------------------------------------------------------------

--
--  MISSION STATEMENT
--  =================
--
--  - Easy to use to create code-driven and data-driven tools.
--  - Easy to use to create ad hoc short-lived tools and long-lived, more elaborate tools.
--  - Easy to hack and improve.
--  - Minimize setup and maintenance.
--  - Minimize state storage on user side.
--  - Minimize state synchronization.
--  - Portable, minimize dependencies, run on target (consoles, phones, etc.).
--  - Efficient runtime and memory consumption.
--
--  Designed primarily for developers and content-creators, not the typical end-user!
--  Some of the current weaknesses (which we aim to address in the future) includes:
--
--  - Doesn't look fancy by default.
--  - Limited layout features, intricate layouts are typically crafted in code.
--
--
--  CONTROLS GUIDE
--  ==============
--
--  - MOUSE CONTROLS
--    - Mouse wheel:                   Scroll vertically.
--    - Shift+Mouse wheel:             Scroll horizontally.
--    - Click [X]:                     Close a window, available when an 'open' value is passed to ImGui.Begin() (open = ImGui.Begin(name, open)).
--    - Click ^, Double-Click title:   Collapse window.
--    - Drag on corner/border:         Resize window (double-click to auto fit window to its contents).
--    - Drag on any empty space:       Move window (unless io.ConfigWindowsMoveFromTitleBarOnly = true).
--    - Left-click outside popup:      Close popup stack (right-click over underlying popup: Partially close popup stack).
--
--  - TEXT EDITOR
--    - Hold Shift or Drag Mouse:      Select text.
--    - Ctrl+Left/Right:               Word jump.
--    - Ctrl+Shift+Left/Right:         Select words.
--    - Ctrl+A or Double-Click:        Select All.
--    - Ctrl+X, Ctrl+C, Ctrl+V:        Use OS clipboard (on Roblox, requires ImGui_ImplRoblox.SetTextProxy(true)).
--    - Ctrl+Z                         Undo.
--    - Ctrl+Y or Ctrl+Shift+Z:        Redo.
--    - ESCAPE:                        Revert text to its original value.
--    - On macOS, controls are automatically adjusted to match standard macOS text editing and behaviors.
--      (for 99% of shortcuts, Ctrl is replaced by Cmd on macOS).
--
--  - KEYBOARD CONTROLS
--    - Basic:
--      - Tab, Shift+Tab               Cycle through text editable fields.
--      - Ctrl+Tab, Ctrl+Shift+Tab     Cycle through windows.
--      - Ctrl+Click                   Input text into a Slider or Drag widget.
--    - Extended features with `io.ConfigFlags = bit32.bor(io.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard)`:
--      - Tab, Shift+Tab:              Cycle through every items.
--      - Arrow keys                   Move through items using directional navigation. Tweak value.
--      - Arrow keys + Alt, Shift      Tweak slower, tweak faster (when using arrow keys).
--      - Enter                        Activate item (prefer text input when possible).
--      - Space                        Activate item (prefer tweaking with arrows when possible).
--      - Escape                       Deactivate item, leave child window, close popup.
--      - Page Up, Page Down           Previous page, next page.
--      - Home, End                    Scroll to top, scroll to bottom.
--      - Alt                          Toggle between scrolling layer and menu layer.
--      - Ctrl+Tab then Ctrl+Arrows    Move window. Hold Shift to resize instead of moving.
--      - Menu or Shift+F10            Open context menu.
--    - Output when ImGuiConfigFlags.NavEnableKeyboard set,
--      - io.WantCaptureKeyboard flag is set when keyboard is claimed.
--      - io.NavActive: true when a window is focused and it doesn't have the ImGuiWindowFlags.NoNavInputs flag set.
--      - io.NavVisible: true when the navigation cursor is visible (usually goes to back false when mouse is used).
--
--  - GAMEPAD CONTROLS
--    - Enable with 'io.ConfigFlags = bit32.bor(io.ConfigFlags, ImGuiConfigFlags.NavEnableGamepad)'.
--    - Particularly useful to use Dear ImGui on a console system (e.g. PlayStation, Switch, Xbox) without a mouse!
--    - Download controller mapping PNG/PSD at http://dearimgui.com/controls_sheets
--    - Backend support: backend needs to:
--       - Set 'io.BackendFlags = bit32.bor(io.BackendFlags, ImGuiBackendFlags.HasGamepad)' + call io:AddKeyEvent()/io:AddKeyAnalogEvent() with ImGuiKey.GamepadXXX keys.
--       - For analog values (0.0 to 1.0), backend is responsible to handling a dead-zone and rescaling inputs accordingly.
--         Backend code will probably need to transform your raw inputs (such as e.g. remapping your 0.2..0.9 raw input range to 0.0..1.0 imgui range, etc.).
--       - (The Roblox and LÖVE backends of this port currently handle mouse and keyboard only: gamepad and touch are not wired up yet.)
--    - If you need to share inputs between your game and the Dear ImGui interface, the easiest approach is to go all-or-nothing,
--      with a buttons combo to toggle the target. Please reach out if you think the game vs navigation input sharing could be improved.
--
--  - REMOTE INPUTS SHARING & MOUSE EMULATION
--    - See https://github.com/ocornut/imgui/wiki/Useful-Extensions#remoting for other remoting solutions.
--    - On a TV/console system where readability may be lower or mouse inputs may be awkward, you may want to set the io.ConfigNavMoveSetMousePos flag.
--      Enabling io.ConfigNavMoveSetMousePos + ImGuiBackendFlags.HasSetMousePos instructs Dear ImGui to move your mouse cursor along with navigation movements.
--      When enabled, the NewFrame() function may alter 'io.MousePos' and set 'io.WantSetMousePos' to notify you that it wants the mouse cursor to be moved.
--      When that happens your backend NEEDS to move the OS or underlying mouse cursor on the next frame.
--      (If you set the io.ConfigNavMoveSetMousePos flag but don't honor 'io.WantSetMousePos' properly, Dear ImGui will misbehave as it will see your mouse moving back & forth!)
--
--
--  PROGRAMMER GUIDE
--  ================
--
--  READ FIRST
--  ----------
--  - Remember to check the wonderful Wiki: https://github.com/ocornut/imgui/wiki
--  - Your code creates the UI every frame of your application loop, if your code doesn't run the UI is gone!
--    The UI can be highly dynamic, there are no construction or destruction steps, less superfluous
--    data retention on your side, less state duplication, less state synchronization, fewer bugs.
--  - Call and read ImGui.ShowDemoWindow() for demo code demonstrating most features (imgui_demo.lua, a port of imgui_demo.cpp).
--    Or browse pthom's online imgui_explorer: https://pthom.github.io/imgui_explorer for a web version w/ source code browser.
--  - Dear ImGui is an implementation of the IMGUI paradigm (immediate-mode graphical user interface, a term coined by Casey Muratori).
--    You can learn about IMGUI principles at http://www.johno.se/book/imgui.html, http://mollyrocket.com/861 & more links in Wiki.
--  - Dear ImGui is a "single pass" rasterizing implementation of the IMGUI paradigm, aimed at ease of use and high-performances.
--    For every application frame, your UI code will be called only once. This is in contrast to e.g. Unity's implementation of an IMGUI,
--    where the UI code is called multiple times ("multiple passes") from a single entry point. There are pros and cons to both approaches.
--  - Our origin is on the top-left. In axis aligned bounding boxes, Min = top-left, Max = bottom-right.
--  - IM_ASSERT() is used throughout the code, like upstream.
--    If you get an assert, read the messages and comments around the assert.
--  - This codebase aims to be highly optimized:
--    - A typical idle frame should allocate as little as possible (in Luau: avoid creating tables/closures per frame).
--    - We rely on a maximum of constant-time or O(N) algorithms. Limiting searches/scans as much as possible.
--  - This codebase aims to be both highly opinionated and highly flexible:
--    - This code works because of the things it choose to solve or not solve.
--    - The port keeps upstream's structure (ImGui is a table of free functions, structures are plain tables)
--      so that upstream code, comments and documentation map almost 1:1. See docs/PORTING.md for the porting rules.
--
--
--  HOW TO UPDATE TO A NEWER VERSION OF DEAR IMGUI
--  ----------------------------------------------
--  - Update by re-pulling this repository (or updating the Wally package / downloading a newer release),
--    then rebuild the bundle (python3 tools/bundle.py, or --target love) and overwrite every file.
--  - This port tracks upstream; read upstream's "API BREAKING CHANGES" (see below) when the tracked upstream version changes.
--    If a function/type has been renamed / or marked obsolete, try to fix the name in your code before it is permanently removed
--    from the public API. If you have a problem with a missing function/symbols, search for its name in the code, there will
--    likely be a comment about it. Please report any issue to the GitHub page!
--  - Try to keep your copy of Dear ImGui reasonably up to date!
--
--
--  GETTING STARTED WITH INTEGRATING DEAR IMGUI IN YOUR CODE/ENGINE
--  ---------------------------------------------------------------
--  - See https://github.com/ocornut/imgui/wiki/Getting-Started, and README.md of this repository.
--  - Run and study the examples and demo in imgui_demo.lua to get acquainted with the library.
--  - In the majority of cases you should be able to use unmodified backends files available in the backends/ folder
--    (backends/imgui_impl_roblox.lua for Roblox, backends/imgui_impl_love.lua for LÖVE).
--  - Build a single file with tools/bundle.py: build/ImGui.luau (Roblox ModuleScript) or build/imgui_love.lua (LÖVE),
--    then require() / load it. All exported names (ImGui, ImVec2, ImVec4, IM_COL32, every ImGui*Flags enum...) are fields of the returned table.
--  - When using Dear ImGui, your programming IDE is your friend: follow the declaration of variables, functions and types to find comments about them.
--  - Dear ImGui never touches or knows about your GPU state. The only function that knows about rendering is the draw function that you provide (the backend's RenderDrawData).
--    Effectively it means you can create widgets at any time in your code, regardless of considerations of being in "update" vs "render"
--    phases of your own application. All rendering information is stored into command-lists that you will retrieve after calling ImGui.Render().
--  - Refer to the backends and demo applications in the examples/ folder for instruction on how to setup your code.
--
--
--  HOW A SIMPLE APPLICATION MAY LOOK LIKE
--  --------------------------------------
--
--  USING THE EXAMPLE BACKENDS (= imgui_impl_XXX.lua files from the backends/ folder).
--  The sub-folders in examples/ contain examples applications following this structure.
--
--  Roblox (LocalScript, see examples/example_roblox/main.client.luau):
--
--      local G = require(ReplicatedStorage:WaitForChild("ImGui"))
--      local ImGui, ImGui_ImplRoblox = G.ImGui, G.ImGui_ImplRoblox
--
--      -- Application init: create a dear imgui context, setup some options, load fonts
--      ImGui.CreateContext()
--      local io = ImGui.GetIO()
--      -- TODO: Set optional io.ConfigFlags values, e.g. 'io.ConfigFlags = bit32.bor(io.ConfigFlags, G.ImGuiConfigFlags.NavEnableKeyboard)' to enable keyboard controls.
--      -- TODO: Fill optional fields of the io structure later.
--      -- TODO: Load TTF/OTF fonts if you don't want to use the default font.
--
--      -- Initialize helper Platform and Renderer backend (here we are using imgui_impl_roblox.lua)
--      ImGui_ImplRoblox.Init()
--
--      -- Application main loop
--      RunService.Stepped:Connect(function()
--          -- Feed inputs to dear imgui, start new frame
--          ImGui_ImplRoblox.NewFrame()
--          ImGui.NewFrame()
--
--          -- Any application code here
--          ImGui.Text("Hello, world!")
--
--          -- Render dear imgui
--          ImGui.Render()
--          ImGui_ImplRoblox.RenderDrawData(ImGui.GetDrawData())
--      end)
--
--      -- Shutdown
--      ImGui_ImplRoblox.Shutdown()
--      ImGui.DestroyContext()
--
--  LÖVE (see examples/example_love/main.lua):
--
--      function love.load()
--          ImGui.CreateContext()
--          G.ImGui_ImplLove.Init({ root = ROOT })
--      end
--      function love.update(dt)
--          G.ImGui_ImplLove.NewFrame()
--          ImGui.NewFrame()
--          ImGui.Text("Hello, world!")
--          ImGui.Render()
--      end
--      function love.draw()
--          G.ImGui_ImplLove.RenderDrawData(ImGui.GetDrawData())
--      end
--      -- + forward love.mousemoved/mousepressed/mousereleased/wheelmoved/keypressed/keyreleased/textinput/focus
--      --   to G.ImGui_ImplLove.MouseMoved/MousePressed/MouseReleased/WheelMoved/KeyPressed/KeyReleased/TextInput/Focus.
--
--  To decide whether to dispatch mouse/keyboard inputs to Dear ImGui to the rest of your application,
--  you should read the 'io.WantCaptureMouse', 'io.WantCaptureKeyboard' and 'io.WantTextInput' flags!
--  Please read the FAQ entry "How can I tell whether to dispatch mouse/keyboard to Dear ImGui or my application?" about this.
--
--
--  USAGE
--  -----
--
--  Widget functions are called every frame; their return values tell you what the user did.
--  Out-parameters of the C++ API (bool* p_open, float* v, int* v...) are passed by value and the new value is returned:
--
--      ImGui.Text("Hello, world %d", 123)
--      if ImGui.Button("Save") then
--          MySaveFunction()
--      end
--      ImGui.InputText("string", buf, 256)                -- buf = ImGui.NewTextBuffer("...", 256), edited in place
--      f = ImGui.SliderFloat("float", f, 0.0, 1.0)        -- returns (value, changed)
--      pressed, v = ImGui.Checkbox("checkbox", v)
--
--      -- Create a window called "My First Tool", with a menu bar.
--      my_tool_active = ImGui.Begin("My First Tool", my_tool_active, ImGuiWindowFlags.MenuBar)  -- returns (open, visible)
--      if ImGui.BeginMenuBar() then
--          if ImGui.BeginMenu("File") then
--              if ImGui.MenuItem("Close", "Ctrl+W") then my_tool_active = false end
--              ImGui.EndMenu()
--          end
--          ImGui.EndMenuBar()
--      end
--      ImGui.ColorEdit4("Color", my_color)                -- ImVec4 / arrays are edited in place
--      ImGui.End()
--
--
-- USING CUSTOM BACKEND / CUSTOM ENGINE
-- ------------------------------------
--
-- A backend implements the usual Dear ImGui contract: Init, NewFrame, RenderDrawData, inputs -> io:AddXXXEvent(),
-- texture updates via ImTextureData. Adding another Lua host means a new backends/imgui_impl_<name>.lua.
--  -> see https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md for basic instructions.
--  -> the backends in backends/imgui_impl_roblox.lua and backends/imgui_impl_love.lua are complete implementations.
--
--  Basic application/backend skeleton:
--
--      -- Application init: create a Dear ImGui context, setup some options, load fonts
--      ImGui.CreateContext()
--      local io = ImGui.GetIO()
--      -- TODO: set io.ConfigXXX values, e.g.
--      io.ConfigFlags = bit32.bor(io.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard)  -- Enable keyboard controls
--
--      -- TODO: Load TTF/OTF fonts if you don't want to use the default font.
--      io.Fonts:AddFontFromFileTTF("fonts/Roboto-Medium.ttf", 16.0)
--
--      -- Application main loop (called once per frame)
--      local function OnFrame(dt)
--          -- Setup low-level inputs, or write to those fields from your input event handlers, etc.
--          -- (In the examples/ app this is usually done within the ImGui_ImplXXX.NewFrame() function from one of the Backends)
--          io.DeltaTime = dt                           -- set the time elapsed since the previous frame (in seconds)
--          io.DisplaySize.x = 1920.0                   -- set the current display width
--          io.DisplaySize.y = 1280.0                   -- set the current display height here
--          io:AddMousePosEvent(mouse_x, mouse_y)       -- update mouse position
--          io:AddMouseButtonEvent(0, mouse_b0)         -- update mouse button states
--          io:AddMouseButtonEvent(1, mouse_b1)         -- update mouse button states
--
--          -- Call NewFrame(), after this point you can use ImGui.* functions anytime
--          -- (So you want to try calling NewFrame() as early as you can in your main loop to be able to use Dear ImGui everywhere)
--          ImGui.NewFrame()
--
--          -- Most of your application code here
--          ImGui.Text("Hello, world!")
--          MyGameUpdate() -- may use any Dear ImGui functions, e.g. ImGui.Begin("My window"); ImGui.Text("Hello, world!"); ImGui.End()
--          MyGameRender() -- may use any Dear ImGui functions as well!
--
--          -- End the dear imgui frame
--          -- (You want to try calling EndFrame/Render as late as you can, to be able to use Dear ImGui in your own game rendering code)
--          ImGui.EndFrame() -- this is automatically called by Render(), but available
--          ImGui.Render()
--
--          -- Update textures
--          local draw_data = ImGui.GetDrawData()
--          for _, tex in draw_data.Textures:iter() do
--              if tex.Status ~= ImTextureStatus.OK then
--                  MyImGuiBackend_UpdateTexture(tex)
--              end
--          end
--
--          -- Render dear imgui contents
--          MyImGuiBackend_RenderDrawData(draw_data)
--      end
--
--      -- Shutdown
--      ImGui.DestroyContext()
--
--
--
--  API BREAKING CHANGES
--  ====================
--
--  This port tracks upstream Dear ImGui 1.93 WIP (docking branch).
--  For the change-log of API breaking changes, see the top of upstream imgui.cpp, or https://github.com/ocornut/imgui/releases
--
--
--  FREQUENTLY ASKED QUESTIONS (FAQ)
--  ================================
--
--  Read all answers online:
--    https://www.dearimgui.com/faq or https://github.com/ocornut/imgui/blob/master/docs/FAQ.md (same url)
--  For questions specific to this port (Roblox, LÖVE, performance, differences from C++), see the FAQ in README.md of this repository.
--

--- Dear ImGui WIP
-- (Core Code)

--- Flags:
-- IMGUI_DISABLE_OBSOLETE_FUNCTIONS = true -- This flag is not implemented

-- NOTE: you must implement ImStd.ImFileOpen if you are not in GMod
IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS = true -- Don't implement ImStd.ImFileOpen/ImStd.ImFileClose/ImStd.ImFileRead/ImFileWrite so you can implement them yourself

IMGUI_DISABLE_DEBUG_TOOLS = false -- Disable metrics/debugger and other debug tools: ShowMetricsWindow(), ShowDebugLogWindow() and ShowIDStackToolWindow() will be empty

-- Current context pointer. Implicitly used by all Dear ImGui functions. Always assumed to be ~= nil.
-- - ImGui.CreateContext() will automatically set this pointer if it is nil.
--   Change to a different context by calling ImGui.SetCurrentContext().
--- @type ImGuiContext?
local GImGui = nil

ImGui = {}

ImStd = {} -- Contains functions that originally don't belong to cpp namespaces

-- IM_INCLUDE(name) is provided by the bundle (see tools/bundle.py): runs the bundled file once, returns its result.

function ImGui._GetTypeFunc() return type end

local function LUA_TableConstructorWrapper(T, size, userdata)
    local p = {}
    for i = 1, size do p[i] = T() end
    return p
end

-- Memory Allocator functions. Use SetAllocatorFunctions() to change them.
-- - You probably don't want to modify that mid-program.
local GImAllocatorAllocFunc = LUA_TableConstructorWrapper
local GImAllocatorFreeFunc = function(p0, p1, p2) end
local GImAllocatorUserData = nil

-- IM_ALLOC() == ImGui.MemAlloc()
--- @param constructor function
--- @param size        int
function ImGui.MemAlloc(constructor, size)
    local p = GImAllocatorAllocFunc(constructor, size, GImAllocatorUserData)
    local ctx = GImGui
    if ctx then
        ImGui.DebugAllocHook(ctx.DebugAllocInfo, ctx.FrameCount, p, size)
    end
    return p
end

-- IM_FREE() == ImGui.MemFree()
-- This does not set `owner[field]` to nil!
--- @param owner table
--- @param field string|int
function ImGui.MemFree(owner, field)
    if owner ~= nil then
        local ctx = GImGui
        if ctx then
            ImGui.DebugAllocHook(ctx.DebugAllocInfo, ctx.FrameCount, owner, -1)
        end
    end
    return GImAllocatorFreeFunc(owner, field, GImAllocatorUserData)
end

-- We record the number of allocation in recent frames, as a way to audit/sanitize our guiding principles of "no allocations on idle/repeating frames"
--- @param info        ImGuiDebugAllocInfo
--- @param frame_count int
--- @param ptr         table
--- @param size        size_t
function ImGui.DebugAllocHook(info, frame_count, ptr, size)
    local entry = info.LastEntriesBuf[info.LastEntriesIdx]
    if entry.FrameCount ~= frame_count then
        info.LastEntriesIdx = info.LastEntriesIdx % (#info.LastEntriesBuf) + 1
        entry = info.LastEntriesBuf[info.LastEntriesIdx]
        entry.FrameCount = frame_count
        entry.AllocCount = 0
        entry.FreeCount = 0
    end
    if size ~= -1 then
        -- print(string.format("[%05d] MemAlloc(%d) -> %p", frame_count, size, ptr))
        entry.AllocCount = entry.AllocCount + 1
        info.TotalAllocCount = info.TotalAllocCount + 1
    else
        -- print(string.format("[%05d] MemFree(%p)", frame_count, ptr))
        entry.FreeCount = entry.FreeCount + 1
        info.TotalFreeCount = info.TotalFreeCount + 1
    end
end

IM_INCLUDE"imgui_h.lua"

IM_INCLUDE"imgui_internal.lua"

IM_INCLUDE"imgui_draw.lua"

IM_INCLUDE"imgui_widgets.lua"

IM_INCLUDE"imgui_tables.lua"


do --[[ [SECTION] imgui_dragdrop (was imgui_dragdrop.lua) ]]
--- Dear ImGui
-- Drag and drop: 1:1 port of imgui.cpp [SECTION] DRAG AND DROP (docking branch)
-- Payload `Data` is any Lua value (no copy is made). `data_size` is optional and only kept for API parity.

-------------------------------------------------------------------------------
-- [SECTION] DRAG AND DROP
-------------------------------------------------------------------------------

function ImGui.IsDragDropActive()
    return ImGui.GetCurrentContext().DragDropActive
end

function ImGui.ClearDragDrop()
    local g = ImGui.GetCurrentContext()
    g.DragDropActive = false
    ImGuiPayload_Clear(g.DragDropPayload)
    g.DragDropAcceptFlagsCurr = ImGuiDragDropFlags.None
    g.DragDropAcceptIdCurr = 0
    g.DragDropAcceptIdPrev = 0
    g.DragDropAcceptIdCurrRectSurface = FLT_MAX
    g.DragDropAcceptFrameCount = -1
end

-- When this returns true you need to: a) call SetDragDropPayload() exactly once, b) you may render the payload visual/description, c) call EndDragDropSource()
-- If the item has an identifier:
-- - This assume/require the item to be activated (typically via ButtonBehavior).
-- - Therefore if you want to use this with a mouse button other than left mouse button, it is up to the item itself to activate with another button.
-- - We then pull and use the mouse button that was used to activate the item and use it to carry on the drag.
-- If the item has no identifier:
-- - Currently always assume left mouse button.
function ImGui.BeginDragDropSource(flags)
    if flags == nil then flags = 0 end
    local g = ImGui.GetCurrentContext()
    local window = g.CurrentWindow

    -- FIXME-DRAGDROP: While in the common-most "drag from non-zero active id" case we can tell the mouse button,
    -- in both SourceExtern and id==0 cases we may requires something else (explicit flags or some heuristic).
    local mouse_button = ImGuiMouseButton.Left

    local source_drag_active = false
    local source_id = 0
    local source_parent_id = 0
    if bit32.band(flags, ImGuiDragDropFlags.SourceExtern) == 0 then
        source_id = g.LastItemData.ID
        if source_id ~= 0 then
            -- Common path: items with ID
            if g.ActiveId ~= source_id then return false end
            if g.ActiveIdMouseButton ~= -1 then mouse_button = g.ActiveIdMouseButton end
            if g.IO.MouseDown[mouse_button] == false or window.SkipItems then return false end
            g.ActiveIdAllowOverlap = false
        else
            -- Uncommon path: items without ID
            if g.IO.MouseDown[mouse_button] == false or window.SkipItems then return false end
            if bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HoveredRect) == 0 and (g.ActiveId == 0 or g.ActiveIdWindow ~= window) then
                return false
            end

            -- If you want to use BeginDragDropSource() on an item with no unique identifier for interaction, such as Text() or Image(), you need to:
            -- A) Read the explanation below, B) Use the ImGuiDragDropFlags.SourceAllowNullID flag.
            if bit32.band(flags, ImGuiDragDropFlags.SourceAllowNullID) == 0 then
                IM_ASSERT(false, "Use ImGuiDragDropFlags.SourceAllowNullID for items without an ID")
                return false
            end

            -- Magic fallback to handle items with no assigned ID, e.g. Text(), Image()
            -- We build a throwaway ID based on current ID stack + relative AABB of items in window.
            -- THE IDENTIFIER WON'T SURVIVE ANY REPOSITIONING/RESIZING OF THE WIDGET, so if your widget moves your dragging operation will be canceled.
            -- We don't need to maintain/call ClearActiveID() as releasing the button will early out this function and trigger !ActiveIdIsAlive.
            -- Rely on keeping other window.LastItemXXX fields intact.
            source_id = window:GetIDFromRectangle(g.LastItemData.Rect)
            g.LastItemData.ID = source_id
            ImGui.KeepAliveID(source_id)
            local is_hovered = ImGui.ItemHoverable(g.LastItemData.Rect, source_id, g.LastItemData.ItemFlags)
            if is_hovered and g.IO.MouseClicked[mouse_button] then
                ImGui.SetActiveID(source_id, window)
                ImGui.FocusWindow(window)
            end
            if g.ActiveId == source_id then g.ActiveIdAllowOverlap = is_hovered end -- Allow the underlying widget to display/return hovered during the mouse release frame, else we would get a flicker.
        end
        if g.ActiveId ~= source_id then return false end
        source_parent_id = window.IDStack.Data[window.IDStack.Size]
        source_drag_active = ImGui.IsMouseDragging(mouse_button)

        -- Disable navigation and key inputs while dragging + cancel existing request if any
        ImGui.SetActiveIdUsingAllKeyboardKeys()
    else
        -- When ImGuiDragDropFlags.SourceExtern is set:
        window = nil
        source_id = ImHashStr("#SourceExtern")
        source_drag_active = true
        mouse_button = g.IO.MouseDown[0] and 0 or -1
        ImGui.KeepAliveID(source_id)
        ImGui.SetActiveID(source_id, nil)
    end

    IM_ASSERT(g.DragDropWithinTarget == false) -- Can't nest BeginDragDropSource() and BeginDragDropTarget()
    if not source_drag_active then return false end

    -- Activate drag and drop
    if not g.DragDropActive then
        IM_ASSERT(source_id ~= 0)
        ImGui.ClearDragDrop()
        local payload = g.DragDropPayload
        payload.SourceId = source_id
        payload.SourceParentId = source_parent_id
        g.DragDropActive = true
        g.DragDropSourceFlags = flags
        g.DragDropMouseButton = mouse_button
        if payload.SourceId == g.ActiveId then g.ActiveIdNoClearOnFocusLoss = true end
    end
    g.DragDropSourceFrameCount = g.FrameCount
    g.DragDropWithinSource = true

    if bit32.band(flags, ImGuiDragDropFlags.SourceNoPreviewTooltip) == 0 then
        -- Target can request the Source to not display its tooltip (we use a dedicated flag to make this request explicit)
        -- We unfortunately can't just modify the source flags and skip the call to BeginTooltip, as caller may be emitting contents.
        local ret
        if g.DragDropAcceptIdPrev ~= 0 and bit32.band(g.DragDropAcceptFlagsPrev, ImGuiDragDropFlags.AcceptNoPreviewTooltip) ~= 0 then
            ret = ImGui.BeginTooltipHidden()
        else
            ret = ImGui.BeginTooltip()
        end
        IM_ASSERT(ret) -- FIXME-NEWBEGIN: If this ever becomes false, we need to Begin("##Hidden", nil, ImGuiWindowFlags.NoSavedSettings) + SetWindowHiddenAndSkipItemsForCurrentFrame().
    end

    if bit32.band(flags, ImGuiDragDropFlags.SourceNoDisableHover) == 0 and bit32.band(flags, ImGuiDragDropFlags.SourceExtern) == 0 then
        g.LastItemData.StatusFlags = bit32.band(g.LastItemData.StatusFlags, bit32.bnot(ImGuiItemStatusFlags.HoveredRect))
    end
    return true
end

function ImGui.EndDragDropSource()
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(g.DragDropActive)
    IM_ASSERT(g.DragDropWithinSource, "Not after a BeginDragDropSource()?")

    if bit32.band(g.DragDropSourceFlags, ImGuiDragDropFlags.SourceNoPreviewTooltip) == 0 then
        ImGui.EndTooltip()
    end

    -- Discard the drag if have not called SetDragDropPayload()
    if g.DragDropPayload.DataFrameCount == -1 then ImGui.ClearDragDrop() end
    g.DragDropWithinSource = false
end

-- Use 'cond' to choose to submit payload on drag start or every frame
--- @param data any # any Lua value
--- @return bool accepted
function ImGui.SetDragDropPayload(type, data, data_size, cond)
    local g = ImGui.GetCurrentContext()
    local payload = g.DragDropPayload
    if cond == nil or cond == 0 then cond = ImGuiCond.Always end

    IM_ASSERT(type ~= nil)
    IM_ASSERT(#type < 32, "Payload type can be at most 32 characters long")
    IM_ASSERT(cond == ImGuiCond.Always or cond == ImGuiCond.Once)
    IM_ASSERT(payload.SourceId ~= 0) -- Not called between BeginDragDropSource() and EndDragDropSource()

    if cond == ImGuiCond.Always or payload.DataFrameCount == -1 then
        -- Copy payload
        payload.DataType = type
        payload.Data = data
        payload.DataSize = data_size or ((data ~= nil) and 1 or 0)
    end
    payload.DataFrameCount = g.FrameCount

    -- Return whether the payload has been accepted
    return (g.DragDropAcceptFrameCount == g.FrameCount) or (g.DragDropAcceptFrameCount == g.FrameCount - 1)
end

function ImGui.BeginDragDropTargetCustom(bb, id)
    local g = ImGui.GetCurrentContext()
    if not g.DragDropActive then return false end

    local window = g.CurrentWindow
    local hovered_window = g.HoveredWindowUnderMovingWindow
    if hovered_window == nil or window.RootWindowDockTree ~= hovered_window.RootWindowDockTree then return false end
    IM_ASSERT(id ~= 0)
    if not ImGui.IsMouseHoveringRect(bb.Min, bb.Max) or (id == g.DragDropPayload.SourceId) then return false end
    if window.SkipItems then return false end

    IM_ASSERT(g.DragDropWithinTarget == false and g.DragDropWithinSource == false) -- Can't nest BeginDragDropSource() and BeginDragDropTarget()
    g.DragDropTargetRect = ImRect(bb.Min, bb.Max)
    g.DragDropTargetClipRect = ImRect(window.ClipRect.Min, window.ClipRect.Max) -- May want to be overridden by user depending on use case?
    g.DragDropTargetId = id
    g.DragDropTargetFullViewport = 0
    g.DragDropWithinTarget = true
    return true
end

-- Typical usage would be:
--   if not ImGui.IsWindowHovered(bit32.bor(ImGuiHoveredFlags.AnyWindow, ImGuiHoveredFlags.AllowWhenBlockedByActiveItem)) then
--       if ImGui.BeginDragDropTargetViewport(ImGui.GetMainViewport(), nil) then
-- But we are leaving the hover test to the caller for maximum flexibility.
function ImGui.BeginDragDropTargetViewport(viewport, p_bb)
    local g = ImGui.GetCurrentContext()
    if not g.DragDropActive then return false end

    local bb = p_bb or viewport:GetWorkRect()
    local id = viewport.ID
    if g.MouseViewport ~= viewport or not ImGui.IsMouseHoveringRect(bb.Min, bb.Max, false) or (id == g.DragDropPayload.SourceId) then
        return false
    end

    IM_ASSERT(g.DragDropWithinTarget == false and g.DragDropWithinSource == false) -- Can't nest BeginDragDropSource() and BeginDragDropTarget()
    g.DragDropTargetRect = ImRect(bb.Min, bb.Max)
    g.DragDropTargetClipRect = ImRect(bb.Min, bb.Max)
    g.DragDropTargetId = id
    g.DragDropTargetFullViewport = id
    g.DragDropWithinTarget = true
    return true
end

-- We don't use BeginDragDropTargetCustom() and duplicate its code because:
-- 1) we use LastItemData's ImGuiItemStatusFlags.HoveredRect which handles items that push a temporarily clip rectangle in their code. Calling BeginDragDropTargetCustom(LastItemRect) would not handle them.
-- 2) and it's faster. as this code may be very frequently called, we want to early out as fast as we can.
-- Also note how the HoveredWindow test is positioned differently in both functions (in both functions we optimize for the cheapest early out case)
function ImGui.BeginDragDropTarget()
    local g = ImGui.GetCurrentContext()
    if not g.DragDropActive then return false end

    local window = g.CurrentWindow
    if bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HoveredRect) == 0 then return false end
    local hovered_window = g.HoveredWindowUnderMovingWindow
    if hovered_window == nil or window.RootWindowDockTree ~= hovered_window.RootWindowDockTree or window.SkipItems then return false end

    local display_rect = (bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HasDisplayRect) ~= 0) and g.LastItemData.DisplayRect or g.LastItemData.Rect
    local id = g.LastItemData.ID
    if id == 0 then
        id = window:GetIDFromRectangle(display_rect)
        ImGui.KeepAliveID(id)
    end
    if g.DragDropPayload.SourceId == id then return false end

    IM_ASSERT(g.DragDropWithinTarget == false and g.DragDropWithinSource == false) -- Can't nest BeginDragDropSource() and BeginDragDropTarget()
    g.DragDropTargetRect = ImRect(display_rect.Min, display_rect.Max)
    local clip = (bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HasClipRect) ~= 0) and g.LastItemData.ClipRect or window.ClipRect
    g.DragDropTargetClipRect = ImRect(clip.Min, clip.Max)
    g.DragDropTargetId = id
    g.DragDropWithinTarget = true
    return true
end

function ImGui.IsDragDropPayloadBeingAccepted()
    local g = ImGui.GetCurrentContext()
    return g.DragDropActive and g.DragDropAcceptIdPrev ~= 0
end

--- @return ImGuiPayload?
function ImGui.AcceptDragDropPayload(type, flags)
    if flags == nil then flags = 0 end
    local g = ImGui.GetCurrentContext()
    local payload = g.DragDropPayload
    IM_ASSERT(g.DragDropActive)                        -- Not called between BeginDragDropTarget() and EndDragDropTarget() ?
    IM_ASSERT(payload.DataFrameCount ~= -1)            -- Forgot to call EndDragDropTarget() ?
    if type ~= nil and not ImGuiPayload_IsDataType(payload, type) then return nil end

    -- Accept smallest drag target bounding box, this allows us to nest drag targets conveniently without ordering constraints.
    -- NB: We currently accept nil id as target. However, overlapping targets requires a unique ID to function!
    local was_accepted_previously = (g.DragDropAcceptIdPrev == g.DragDropTargetId)
    local r = g.DragDropTargetRect
    local r_surface = r:GetWidth() * r:GetHeight()
    if r_surface > g.DragDropAcceptIdCurrRectSurface then return nil end

    g.DragDropAcceptFlagsCurr = flags
    g.DragDropAcceptIdCurr = g.DragDropTargetId
    g.DragDropAcceptIdCurrRectSurface = r_surface
    -- IMGUI_DEBUG_LOG("AcceptDragDropPayload(): %08X: accept\n", g.DragDropTargetId)

    -- Render default drop visuals
    payload.Preview = was_accepted_previously
    flags = bit32.bor(flags, bit32.band(g.DragDropSourceFlags, ImGuiDragDropFlags.AcceptNoDrawDefaultRect)) -- Source can also inhibit the preview (useful for external sources that live for 1 frame)
    local draw_target_rect = payload.Preview and bit32.band(flags, ImGuiDragDropFlags.AcceptNoDrawDefaultRect) == 0
    if draw_target_rect and g.DragDropTargetFullViewport ~= 0 then
        ImGui.RenderDragDropTargetRectForViewport(g.DragDropTargetFullViewport, g.DragDropTargetRect)
    elseif draw_target_rect then
        ImGui.RenderDragDropTargetRectForItem(r)
    end

    g.DragDropAcceptFrameCount = g.FrameCount
    if bit32.band(g.DragDropSourceFlags, ImGuiDragDropFlags.SourceExtern) ~= 0 and g.DragDropMouseButton == -1 then
        payload.Delivery = was_accepted_previously and (g.DragDropSourceFrameCount < g.FrameCount)
    else
        payload.Delivery = was_accepted_previously and not ImGui.IsMouseDown(g.DragDropMouseButton) -- For extern drag sources affecting OS window focus, it's easier to just test not IsMouseDown() instead of IsMouseReleased()
    end
    if not payload.Delivery and bit32.band(flags, ImGuiDragDropFlags.AcceptBeforeDelivery) == 0 then return nil end
    return payload
end

-- FIXME-STYLE FIXME-DRAGDROP: Settle on a proper default visuals for drop target.
function ImGui.RenderDragDropTargetRectForItem(bb)
    local g = ImGui.GetCurrentContext()
    local window = g.CurrentWindow
    local bb_display = ImRect(bb.Min, bb.Max)
    bb_display:ClipWith(g.DragDropTargetClipRect) -- Clip THEN expand so we have a way to visualize that target is not entirely visible.
    bb_display:Expand(g.Style.DragDropTargetPadding)
    local push_clip_rect = not window.ClipRect:Contains(bb_display)
    if push_clip_rect then window.DrawList:PushClipRectFullScreen() end
    ImGui.RenderDragDropTargetRectEx(window.DrawList, bb_display, g.Style.DragDropTargetRounding)
    if push_clip_rect then window.DrawList:PopClipRect() end
end

function ImGui.RenderDragDropTargetRectForViewport(viewport_id, bb)
    local g = ImGui.GetCurrentContext()
    local viewport = ImGui.FindViewportByID(viewport_id)
    IM_ASSERT(viewport ~= nil)
    local bb_padded = ImRect(bb.Min, bb.Max)
    bb_padded:Expand(-g.Style.DragDropTargetPadding)
    ImGui.RenderDragDropTargetRectEx(ImGui.GetForegroundDrawList(viewport), bb_padded, g.Style.DragDropTargetRounding)
end

function ImGui.RenderDragDropTargetRectEx(draw_list, bb, rounding)
    local g = ImGui.GetCurrentContext()
    draw_list:AddRectFilled(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.DragDropTargetBg), rounding, 0)
    draw_list:AddRect(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.DragDropTarget), rounding, g.Style.DragDropTargetBorderSize)
end

--- @return ImGuiPayload?
function ImGui.GetDragDropPayload()
    local g = ImGui.GetCurrentContext()
    return (g.DragDropActive and g.DragDropPayload.DataFrameCount ~= -1) and g.DragDropPayload or nil
end

function ImGui.EndDragDropTarget()
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(g.DragDropActive)
    IM_ASSERT(g.DragDropWithinTarget)
    g.DragDropWithinTarget = false

    -- Clear drag and drop state payload right after delivery
    if g.DragDropPayload.Delivery then ImGui.ClearDragDrop() end
end

-- Payload methods (C++ ImGuiPayload members): payload:IsDataType(t) etc. also work through these globals
function ImGui.PayloadIsDataType(payload, t) return ImGuiPayload_IsDataType(payload, t) end
end --[[ [SECTION] imgui_dragdrop (was imgui_dragdrop.lua) ]]

do --[[ [SECTION] imgui_docking (was imgui_docking.lua) ]]
--- Dear ImGui
-- Docking: 1:1 port of imgui.cpp [SECTION] DOCKING (docking branch, 1.93 WIP)
--
-- Port notes:
-- - Main viewport only (no multi-viewports on Roblox): viewport creation/merging code paths are kept where cheap, but
--   windows always live in the main viewport.
-- - ImGuiDockContext.Nodes (ImGuiStorage in C++) is a Lua table ID -> node. Iterations that upstream does over the
--   sorted storage are done over a sorted snapshot of the IDs (DockContextNodesSorted) for deterministic order.
-- - node.ChildNodes is a table indexed [0] and [1] like upstream.
-- - ImGuiDockPreviewData.DropRectsDraw is indexed [dir + 1] with dir in -1..3 (so keys 0..4), like upstream.

-------------------------------------------------------------------------------
-- [SECTION] DOCKING
-------------------------------------------------------------------------------
-- Docking: Internal Types
-- Docking: Forward Declarations
-- Docking: ImGuiDockContext
-- Docking: ImGuiDockContext Docking/Undocking functions
-- Docking: ImGuiDockNode
-- Docking: ImGuiDockNode Tree manipulation functions
-- Docking: Public Functions (SetWindowDock, DockSpace, DockSpaceOverViewport)
-- Docking: Builder Functions
-- Docking: Begin/End Support Functions (called from Begin/End)
-- Docking: Settings
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
-- Typical Docking call flow: (root level is generally public API):
-------------------------------------------------------------------------------
-- - NewFrame()                               new dear imgui frame
--    | DockContextNewFrameUpdateUndocking()  - process queued undocking requests
--    | - DockContextProcessUndockWindow()    - process one window undocking request
--    | - DockContextProcessUndockNode()      - process one whole node undocking request
--    | DockContextNewFrameUpdateUndocking()  - process queue docking requests, create floating dock nodes
--    | - update g.HoveredDockNode            - [debug] update node hovered by mouse
--    | - DockContextProcessDock()            - process one docking request
--    | - DockNodeUpdate()
--    |   - DockNodeUpdateForRootNode()
--    |     - DockNodeUpdateFlagsAndCollapse()
--    |     - DockNodeFindInfo()
--    |   - destroy unused node or tab bar
--    |   - create dock node host window
--    |      - Begin() etc.
--    |   - DockNodeStartMouseMovingWindow()
--    |   - DockNodeTreeUpdatePosSize()
--    |   - DockNodeTreeUpdateSplitter()
--    |   - draw node background
--    |   - DockNodeUpdateTabBar()            - create/update tab bar for a docking node
--    |     - DockNodeAddTabBar()
--    |     - DockNodeWindowMenuUpdate()
--    |     - DockNodeCalcTabBarLayout()
--    |     - BeginTabBarEx()
--    |     - TabItemEx() calls
--    |     - EndTabBar()
--    |   - BeginDockableDragDropTarget()
--    |      - DockNodeUpdate()               - recurse into child nodes...
-------------------------------------------------------------------------------
-- - DockSpace()                              user submit a dockspace into a window
--    | Begin(Child)                          - create a child window
--    | DockNodeUpdate()                      - call main dock node update function
--    | End(Child)
--    | ItemSize()
-------------------------------------------------------------------------------
-- - Begin()
--    | BeginDocked()
--    | BeginDockableDragDropSource()
--    | BeginDockableDragDropTarget()
--    | - DockNodePreviewDockRender()
-------------------------------------------------------------------------------
-- - EndFrame()
--    | DockContextEndFrame()
-------------------------------------------------------------------------------

local MT = ImGui.GetMetatables()

IMGUI_PAYLOAD_TYPE_WINDOW = "_IMWINDOW" -- Payload == ImGuiWindow

local DOCKING_HOST_DRAW_CHANNEL_BG = 0 -- Dock host: background fill
local DOCKING_HOST_DRAW_CHANNEL_FG = 1 -- Dock host: decorations and contents

local DOCKING_SPLITTER_SIZE = 2.0

-------------------------------------------------------------------------------
-- Docking: flags & enums
-------------------------------------------------------------------------------

-- Flags for ImGui.DockSpace(), shared/inherited by child nodes.
-- (Some flags can be applied to individual nodes directly)
-- FIXME-DOCK: Also see ImGuiDockNodeFlagsPrivate_ which may involve using the WIP and internal DockBuilder api.
ImGuiDockNodeFlags = {
    None                         = 0,
    KeepAliveOnly                = bit32.lshift(1, 0),  --       -- Don't display the dockspace node but keep it alive. Windows docked into this dockspace node won't be undocked.
    -- NoCentralNode             = bit32.lshift(1, 1),  --       -- Disable Central Node (the node which can stay empty)
    NoDockingOverCentralNode     = bit32.lshift(1, 2),  --       -- Disable docking over the Central Node, which will be always kept empty.
    PassthruCentralNode          = bit32.lshift(1, 3),  --       -- Enable passthru dockspace: 1) DockSpace() will render a ImGuiCol.WindowBg background covering everything excepted the Central Node when empty. Meaning the host window should probably use SetNextWindowBgAlpha(0.0) prior to Begin() when using this. 2) When Central Node is empty: let inputs pass-through + won't display a DockingEmptyBg background. See demo for details.
    NoDockingSplit               = bit32.lshift(1, 4),  --       -- Disable other windows/nodes from splitting this node.
    NoResize                     = bit32.lshift(1, 5),  -- Saved -- Disable resizing node using the splitter/separators. Useful with programmatically setup dockspaces.
    AutoHideTabBar               = bit32.lshift(1, 6),  --       -- Tab bar will automatically hide when there is a single window in the dock node.
    NoUndocking                  = bit32.lshift(1, 7),  --       -- Disable undocking this node.

    -- Extend ImGuiDockNodeFlags_ (ImGuiDockNodeFlagsPrivate_)
    -- [Internal]
    DockSpace                    = bit32.lshift(1, 10), -- Saved -- A dockspace is a node that occupy space within an existing user window. Otherwise the node is floating and create its own window.
    CentralNode                  = bit32.lshift(1, 11), -- Saved -- The central node has 2 main properties: stay visible when empty, only use "remaining" spaces from its neighbor.
    NoTabBar                     = bit32.lshift(1, 12), -- Saved -- Tab bar is completely unavailable. No triangle in the corner to enable it back.
    HiddenTabBar                 = bit32.lshift(1, 13), -- Saved -- Tab bar is hidden, with a triangle in the corner to show it again (NB: actual tab-bar instance may be destroyed as this is only used for single-window tab bar)
    NoWindowMenuButton           = bit32.lshift(1, 14), -- Saved -- Disable window/docking menu (that one that appears instead of the collapse button)
    NoCloseButton                = bit32.lshift(1, 15), -- Saved -- Disable close button
    NoResizeX                    = bit32.lshift(1, 16), --       --
    NoResizeY                    = bit32.lshift(1, 17), --       --
    DockedWindowsInFocusRoute    = bit32.lshift(1, 18), --       -- Any docked window will be automatically be focus-route chained (window.ParentWindowForFocusRoute set to this) so Shortcut() in this window can run when any docked window is focused.

    -- Disable docking/undocking actions in this dockspace or individual node (existing docked nodes will be preserved)
    -- Those are not exposed in public because the desirable sharing/inheriting/copy-flag-on-split behaviors are quite difficult to design and understand.
    -- The two public flags ImGuiDockNodeFlags.NoDockingOverCentralNode/ImGuiDockNodeFlags.NoDockingSplit don't have those issues.
    NoDockingSplitOther          = bit32.lshift(1, 19), --       -- Disable this node from splitting other windows/nodes.
    NoDockingOverMe              = bit32.lshift(1, 20), --       -- Disable other windows/nodes from being docked over this node.
    NoDockingOverOther           = bit32.lshift(1, 21), --       -- Disable this node from being docked over another window or non-empty node.
    NoDockingOverEmpty           = bit32.lshift(1, 22), --       -- Disable this node from being docked over an empty node (e.g. DockSpace with no other windows)
}
do
    local F = ImGuiDockNodeFlags
    F.NoSplit = F.NoDockingSplit -- Renamed in 1.90
    F.NoDockingInCentralNode = F.NoDockingOverCentralNode -- Renamed in 1.90
    F.NoDocking = bit32.bor(F.NoDockingOverMe, F.NoDockingOverOther, F.NoDockingOverEmpty, F.NoDockingSplit, F.NoDockingSplitOther)
    -- Masks
    F.SharedFlagsInheritMask_ = 0xFFFFFFFF
    F.NoResizeFlagsMask_ = bit32.bor(F.NoResize, F.NoResizeX, F.NoResizeY)
    -- When splitting, those local flags are moved to the inheriting child, never duplicated
    F.LocalFlagsTransferMask_ = bit32.bor(F.NoDockingSplit, F.NoResizeFlagsMask_, F.AutoHideTabBar, F.CentralNode, F.NoTabBar, F.HiddenTabBar, F.NoWindowMenuButton, F.NoCloseButton)
    F.SavedFlagsMask_ = bit32.bor(F.NoResizeFlagsMask_, F.DockSpace, F.CentralNode, F.NoTabBar, F.HiddenTabBar, F.NoWindowMenuButton, F.NoCloseButton)
end

-- Store the source authority (dock node vs window) of a field
ImGuiDataAuthority = { Auto = 0, DockNode = 1, Window = 2 }

ImGuiDockNodeState = {
    Unknown = 0,
    HostWindowHiddenBecauseSingleWindow = 1,
    HostWindowHiddenBecauseWindowsAreResizing = 2,
    HostWindowVisible = 3,
}

-- List of colors that are stored at the time of Begin() into Docked Windows.
-- We currently store the packed colors in a simple array window.DockStyle.Colors[].
-- A better solution may involve appending into a log of colors in ImGuiContext + store offsets into those arrays in ImGuiWindow,
-- but it would be more complex as we'd need to double-buffer both as e.g. drop target may refer to window from last frame.
ImGuiWindowDockStyleCol = {
    Text = 0, TabHovered = 1, TabFocused = 2, TabSelected = 3, TabSelectedOverline = 4,
    TabDimmed = 5, TabDimmedSelected = 6, TabDimmedSelectedOverline = 7, UnsavedMarker = 8, COUNT = 9,
}

-------------------------------------------------------------------------------
-- Docking: Internal Types
-------------------------------------------------------------------------------
-- - ImGuiDockRequestType
-- - ImGuiDockRequest
-- - ImGuiDockPreviewData
-- - ImGuiDockNodeSettings
-- - ImGuiDockContext
-------------------------------------------------------------------------------

local ImGuiDockRequestType = { None = 0, Dock = 1, Undock = 2, Split = 3 } -- Split is the same as Dock but without a DockPayload

local function ImGuiDockRequest()
    return {
        Type = ImGuiDockRequestType.None,
        -- DockTargetWindow: Destination/Target Window to dock into (may be a loose window or a DockNode, might be nil in which case DockTargetNode cannot be nil)
        -- DockTargetNode: Destination/Target Node to dock into
        -- DockPayload: Source/Payload window to dock (may be a loose window or a DockNode), [Optional]
        DockTargetWindow = nil, DockTargetNode = nil, DockPayload = nil,
        DockSplitDir = ImGuiDir.None, DockSplitRatio = 0.5, DockSplitOuter = false,
        UndockTargetWindow = nil, UndockTargetNode = nil,
    }
end

-- Persistent Settings data, stored contiguously in SettingsNodes
local function ImGuiDockNodeSettings()
    return {
        ID = 0, ParentNodeId = 0, ParentWindowId = 0, SelectedTabId = 0,
        SplitAxis = ImGuiAxis.None, Depth = 0, Flags = 0, -- Flags: NB: We save individual flags one by one in ascii format (ImGuiDockNodeFlags.SavedFlagsMask_)
        Pos = ImVec2(0, 0), Size = ImVec2(0, 0), SizeRef = ImVec2(0, 0),
    }
end

function ImGuiDockContext()
    -- Nodes: Map ID -> ImGuiDockNode: Active nodes
    return { Nodes = {}, Requests = ImVector(), NodesSettings = ImVector(), WantFullRebuild = false }
end

MT.ImGuiDockNode = {}
MT.ImGuiDockNode.__index = MT.ImGuiDockNode
local DN = MT.ImGuiDockNode

function ImGuiDockNode(id)
    return setmetatable({
        ID = id,
        -- SharedFlags: (Write) Flags shared by all nodes of a same dockspace hierarchy (inherited from the root node)
        -- LocalFlags: (Write) Flags specific to this node
        -- LocalFlagsInWindows: (Write) Flags specific to this node, applied from windows
        -- MergedFlags: (Read)  Effective flags (== SharedFlags | LocalFlagsInNode | LocalFlagsInWindows)
        SharedFlags = 0, LocalFlags = 0, LocalFlagsInWindows = 0, MergedFlags = 0,
        State = ImGuiDockNodeState.Unknown,
        ParentNode = nil,
        ChildNodes = { [0] = nil, [1] = nil }, -- [Split node only] Child nodes (left/right or top/bottom). Consider switching to an array.
        Windows = ImVector(), -- Note: unordered list! Iterate TabBar.Tabs for user-order.
        TabBar = nil,
        -- Pos: Current position
        -- Size: Current size
        -- SizeRef: [Split node only] Last explicitly written-to size (overridden when using a splitter affecting the node), used to calculate Size.
        Pos = ImVec2(0, 0), Size = ImVec2(0, 0), SizeRef = ImVec2(0, 0),
        SplitAxis = ImGuiAxis.None, -- [Split node only] Split axis (X or Y)
        LastBgColor = IM_COL32_WHITE,
        WindowClass = ImGuiWindowClass(), -- [Root node only]
        -- VisibleWindow: Generally point to window which is ID is == SelectedTabID, but when CTRL+Tabbing this can be a different window.
        HostWindow = nil, VisibleWindow = nil,
        -- CentralNode: [Root node only] Pointer to central node.
        -- OnlyNodeWithWindows: [Root node only] Set when there is a single visible node within the hierarchy.
        CentralNode = nil, OnlyNodeWithWindows = nil,
        CountNodeWithWindows = 0, -- [Root node only]
        -- LastFrameAlive: Last frame number the node was updated or kept alive explicitly with DockSpace() + ImGuiDockNodeFlags.KeepAliveOnly
        -- LastFrameActive: Last frame number the node was updated.
        -- LastFrameFocused: Last frame number the node was focused.
        LastFrameAlive = -1, LastFrameActive = -1, LastFrameFocused = -1,
        -- LastFocusedNodeId: [Root node only] Which of our child docking node (any ancestor in the hierarchy) was last focused.
        -- SelectedTabId: [Leaf node only] Which of our tab/window is selected.
        -- WantCloseTabId: [Leaf node only] Set when closing a specific tab/window.
        -- RefViewportId: Reference viewport ID from visible window when HostWindow == nil.
        LastFocusedNodeId = 0, SelectedTabId = 0, WantCloseTabId = 0, RefViewportId = 0,
        AuthorityForPos = ImGuiDataAuthority.DockNode, AuthorityForSize = ImGuiDataAuthority.DockNode, -- ImGuiDataAuthority
        AuthorityForViewport = ImGuiDataAuthority.Auto,
        IsVisible = true, IsFocused = false, IsBgDrawnThisFrame = false, -- IsVisible: Set to false when the node is hidden (usually disabled as it has no active window)
        HasCloseButton = false, HasWindowMenuButton = false, HasCentralNodeChild = false, -- HasCloseButton: Provide space for a close button (if any of the docked window has one). Note that button may be hidden on window without one.
        -- WantCloseAll: Set when closing all tabs at once.
        -- WantMouseMove: After a node extraction we need to transition toward moving the newly created host window
        WantCloseAll = false, WantLockSizeOnce = false, WantMouseMove = false,
        WantHiddenTabBarUpdate = false, WantHiddenTabBarToggle = false,
    }, DN)
end

function DN:IsRootNode()     return self.ParentNode == nil end
function DN:IsDockSpace()    return bit32.band(self.MergedFlags, ImGuiDockNodeFlags.DockSpace) ~= 0 end
function DN:IsFloatingNode() return self.ParentNode == nil and bit32.band(self.MergedFlags, ImGuiDockNodeFlags.DockSpace) == 0 end
function DN:IsCentralNode()  return bit32.band(self.MergedFlags, ImGuiDockNodeFlags.CentralNode) ~= 0 end
function DN:IsHiddenTabBar() return bit32.band(self.MergedFlags, ImGuiDockNodeFlags.HiddenTabBar) ~= 0 end -- Hidden tab bar can be shown back by clicking the small triangle
function DN:IsNoTabBar()     return bit32.band(self.MergedFlags, ImGuiDockNodeFlags.NoTabBar) ~= 0 end     -- Never show a tab bar
function DN:IsSplitNode()    return self.ChildNodes[0] ~= nil end
function DN:IsLeafNode()     return self.ChildNodes[0] == nil end
function DN:IsEmpty()        return self.ChildNodes[0] == nil and self.Windows.Size == 0 end
function DN:Rect()           return ImRect(self.Pos.x, self.Pos.y, self.Pos.x + self.Size.x, self.Pos.y + self.Size.y) end
function DN:SetLocalFlags(flags) self.LocalFlags = flags; self:UpdateMergedFlags() end
function DN:UpdateMergedFlags() self.MergedFlags = bit32.bor(self.SharedFlags, self.LocalFlags, self.LocalFlagsInWindows) end

local function ImGuiDockPreviewData()
    local d = {
        FutureNode = ImGuiDockNode(0),
        -- IsSidesAvailable: Hold your breath, grammar freaks..
        -- IsSplitDirExplicit: Set when hovered the drop rect (vs. implicit SplitDir==None when hovered the window)
        IsDropAllowed = false, IsCenterAvailable = false, IsSidesAvailable = false, IsSplitDirExplicit = false,
        SplitNode = nil, SplitDir = ImGuiDir.None, SplitRatio = 0.0,
        DropRectsDraw = {}, -- May be slightly different from hit-testing drop rects used in DockNodeCalcDropRects()
    }
    for n = 0, 4 do d.DropRectsDraw[n] = ImRect(FLT_MAX, FLT_MAX, -FLT_MAX, -FLT_MAX) end
    return d
end

local function DockNodeGetHostWindowTitle(node)
    return string.format("##DockNode_%02X", node.ID)
end

local function IsRectInverted(r) return r.Min.x > r.Max.x or r.Min.y > r.Max.y end

--- Sorted snapshot of node IDs (upstream iterates ImGuiStorage which is sorted by key)
local function DockContextNodesSorted(ctx)
    local ids = {}
    for id in pairs(ctx.DockContext.Nodes) do ids[#ids + 1] = id end
    table.sort(ids)
    return ids
end
ImGui.DockContextNodesSorted = DockContextNodesSorted

-------------------------------------------------------------------------------
-- Docking: Forward Declarations
-------------------------------------------------------------------------------

-- Settings
local DockSettingsHandler_ClearAll, DockSettingsHandler_ApplyAll, DockSettingsHandler_ReadOpen, DockSettingsHandler_ReadLine, DockSettingsHandler_WriteAll
local DockSettingsRenameNodeReferences, DockSettingsRemoveNodeReferences, DockSettingsFindNodeSettings

-------------------------------------------------------------------------------
-- Docking: ImGuiDockContext
-------------------------------------------------------------------------------
-- The lifetime model is different from the one of regular windows: we always create a ImGuiDockNode for each ImGuiDockNodeSettings,
-- or we always hold the entire docking node tree. Nodes are frequently hidden, e.g. if the window(s) or child nodes they host are not active.
-- At boot time only, we run a simple GC to remove nodes that have no references.
-- Because dock node settings (which are small, contiguous structures) are always mirrored by their corresponding dock nodes (more complete structures),
-- we can also very easily recreate the nodes from scratch given the settings data (this is what DockContextRebuild() does).
-- This is convenient as docking reconfiguration can be implemented by mostly poking at the simpler settings data.
-------------------------------------------------------------------------------
-- - DockContextInitialize()
-- - DockContextShutdown()
-- - DockContextClearNodes()
-- - DockContextRebuildNodes()
-- - DockContextNewFrameUpdateUndocking()
-- - DockContextNewFrameUpdateDocking()
-- - DockContextEndFrame()
-- - DockContextFindNodeByID()
-- - DockContextBindNodeToWindow()
-- - DockContextGenNodeID()
-- - DockContextAddNode()
-- - DockContextRemoveNode()
-- - ImGuiDockContextPruneNodeData
-- - DockContextPruneUnusedSettingsNodes()
-- - DockContextBuildNodesFromSettings()
-- - DockContextBuildAddWindowsToNodes()
-------------------------------------------------------------------------------

function ImGui.DockContextInitialize(ctx)
    local g = ctx

    -- Add .ini handle for persistent docking data
    local ini_handler = ImGuiSettingsHandler()
    ini_handler.TypeName = "Docking"
    ini_handler.TypeHash = ImHashStr("Docking")
    ini_handler.ClearAllFn = DockSettingsHandler_ClearAll
    ini_handler.ReadInitFn = DockSettingsHandler_ClearAll -- Also clear on read
    ini_handler.ReadOpenFn = DockSettingsHandler_ReadOpen
    ini_handler.ReadLineFn = DockSettingsHandler_ReadLine
    ini_handler.ApplyAllFn = DockSettingsHandler_ApplyAll
    ini_handler.WriteAllFn = DockSettingsHandler_WriteAll
    g.SettingsHandlers:push_back(ini_handler)

    g.DockNodeWindowMenuHandler = ImGui.DockNodeWindowMenuHandler_Default
end

function ImGui.DockContextShutdown(ctx)
    for _, id in ipairs(DockContextNodesSorted(ctx)) do
        local node = ctx.DockContext.Nodes[id]
        if node then ImGui.DockContextDeleteNode(ctx, node) end
    end
end

function ImGui.DockContextClearNodes(ctx, root_id, clear_settings_refs)
    ImGui.DockBuilderRemoveNodeDockedWindows(root_id, clear_settings_refs)
    ImGui.DockBuilderRemoveNodeChildNodes(root_id)
end

-- [DEBUG] This function also acts as a defacto test to make sure we can rebuild from scratch without a glitch
-- (Different from DockSettingsHandler_ClearAll() + DockSettingsHandler_ApplyAll() because this reuses current settings!)
function ImGui.DockContextRebuildNodes(ctx)
    local dc = ctx.DockContext
    ImGui.SaveIniSettingsToMemory()
    local root_id = 0 -- Rebuild all
    ImGui.DockContextClearNodes(ctx, root_id, false)
    ImGui.DockContextBuildNodesFromSettings(ctx, dc.NodesSettings.Data, dc.NodesSettings.Size)
    ImGui.DockContextBuildAddWindowsToNodes(ctx, root_id)
end

-- Docking context update function, called by NewFrame()
function ImGui.DockContextNewFrameUpdateUndocking(ctx)
    local g = ctx
    local dc = ctx.DockContext
    if bit32.band(g.IO.ConfigFlags, ImGuiConfigFlags.DockingEnable) == 0 then
        if next(dc.Nodes) ~= nil or dc.Requests.Size > 0 then
            ImGui.DockContextClearNodes(ctx, 0, true)
        end
        return
    end

    -- Setting NoSplit at runtime merges all nodes
    if g.IO.ConfigDockingNoSplit then
        for _, id in ipairs(DockContextNodesSorted(ctx)) do
            local node = dc.Nodes[id]
            if node and node:IsRootNode() and node:IsSplitNode() then
                ImGui.DockBuilderRemoveNodeChildNodes(node.ID)
                -- dc.WantFullRebuild = true
            end
        end
    end

    -- Process full rebuild
    if dc.WantFullRebuild then
        ImGui.DockContextRebuildNodes(ctx)
        dc.WantFullRebuild = false
    end

    -- Process Undocking requests (we need to process them _before_ the UpdateMouseMovingWindowNewFrame call in NewFrame)
    for _, req in dc.Requests:iter() do
        if req.Type == ImGuiDockRequestType.Undock and req.UndockTargetWindow then
            ImGui.DockContextProcessUndockWindow(ctx, req.UndockTargetWindow)
        elseif req.Type == ImGuiDockRequestType.Undock and req.UndockTargetNode then
            ImGui.DockContextProcessUndockNode(ctx, req.UndockTargetNode)
        end
    end
end

-- Docking context update function, called by NewFrame()
function ImGui.DockContextNewFrameUpdateDocking(ctx)
    local g = ctx
    local dc = ctx.DockContext
    if bit32.band(g.IO.ConfigFlags, ImGuiConfigFlags.DockingEnable) == 0 then return end

    -- [DEBUG] Store hovered dock node.
    -- We could in theory use DockNodeTreeFindVisibleNodeByPos() on the root host dock node, but using .DockNode is a good shortcut.
    -- Note this is mostly a debug thing and isn't actually used for docking target, because docking involve more detailed filtering.
    g.DebugHoveredDockNode = nil
    local hovered_window = g.HoveredWindowUnderMovingWindow
    if hovered_window then
        if hovered_window.DockNodeAsHost then
            g.DebugHoveredDockNode = ImGui.DockNodeTreeFindVisibleNodeByPos(hovered_window.DockNodeAsHost, g.IO.MousePos)
        elseif hovered_window.RootWindow.DockNode then
            g.DebugHoveredDockNode = hovered_window.RootWindow.DockNode
        end
    end

    -- Process Docking requests
    for _, req in dc.Requests:iter() do
        if req.Type == ImGuiDockRequestType.Dock then
            ImGui.DockContextProcessDock(ctx, req)
        end
    end
    dc.Requests:resize(0)

    -- Create windows for each automatic docking nodes
    for _, id in ipairs(DockContextNodesSorted(ctx)) do
        local node = dc.Nodes[id]
        if node and node:IsFloatingNode() then
            ImGui.DockNodeUpdate(node)
        end
    end
end

function ImGui.DockContextEndFrame(ctx)
    -- Draw backgrounds of node missing their window
    local g = ctx
    local dc = g.DockContext
    for _, id in ipairs(DockContextNodesSorted(ctx)) do
        local node = dc.Nodes[id]
        if node and node.LastFrameActive == g.FrameCount and node.IsVisible and node.HostWindow and node:IsLeafNode() and not node.IsBgDrawnThisFrame then
            local bg_rect = ImRect(node.Pos + ImVec2(0.0, ImGui.GetFrameHeight()), node.Pos + node.Size)
            local bg_rounding_flags = ImGui.CalcRoundingFlagsForRectInRect(bg_rect, node.HostWindow:Rect(), g.Style.DockingSeparatorSize)
            node.HostWindow.DrawList:ChannelsSetCurrent(DOCKING_HOST_DRAW_CHANNEL_BG)
            node.HostWindow.DrawList:AddRectFilled(bg_rect.Min, bg_rect.Max, node.LastBgColor, node.HostWindow.WindowRounding, bg_rounding_flags)
        end
    end
end

function ImGui.DockContextFindNodeByID(ctx, id)
    return ctx.DockContext.Nodes[id]
end

function ImGui.DockContextGenNodeID(ctx)
    -- Generate an ID for new node (the exact ID value doesn't matter as long as it is not already used)
    -- FIXME-OPT FIXME-DOCK: This is suboptimal, even if the node count is small enough not to be a worry.0
    -- We should poke in ctx.Nodes to find a suitable ID faster. Even more so trivial that ctx.Nodes lookup is already sorted.
    local id = 0x0001
    while ImGui.DockContextFindNodeByID(ctx, id) ~= nil do id = id + 1 end
    return id
end

function ImGui.DockContextAddNode(ctx, id)
    -- Generate an ID for the new node (the exact ID value doesn't matter as long as it is not already used) and add the first window.
    if id == 0 then
        id = ImGui.DockContextGenNodeID(ctx)
    else
        IM_ASSERT(ImGui.DockContextFindNodeByID(ctx, id) == nil)
    end

    -- We don't set node.LastFrameAlive on construction. Nodes are always created at all time to reflect .ini settings!
    local node = ImGuiDockNode(id)
    ctx.DockContext.Nodes[node.ID] = node
    return node
end

function ImGui.DockContextRemoveNode(ctx, node, merge_sibling_into_parent_node)
    IM_ASSERT(ImGui.DockContextFindNodeByID(ctx, node.ID) == node)
    IM_ASSERT(node.ChildNodes[0] == nil and node.ChildNodes[1] == nil)
    IM_ASSERT(node.Windows.Size == 0)

    if node.HostWindow then node.HostWindow.DockNodeAsHost = nil end

    local parent_node = node.ParentNode
    local merge = (merge_sibling_into_parent_node and parent_node ~= nil)
    if merge then
        IM_ASSERT(parent_node.ChildNodes[0] == node or parent_node.ChildNodes[1] == node)
        local sibling_node = (parent_node.ChildNodes[0] == node) and parent_node.ChildNodes[1] or parent_node.ChildNodes[0]
        ImGui.DockNodeTreeMerge(ctx, parent_node, sibling_node)
    else
        if parent_node then
            for n = 0, 1 do
                if parent_node.ChildNodes[n] == node then node.ParentNode.ChildNodes[n] = nil end
            end
        end
        ImGui.DockContextDeleteNode(ctx, node)
    end
end

-- Raw-ish delete
function ImGui.DockContextDeleteNode(ctx, node)
    local dc = ctx.DockContext
    node.TabBar = nil
    dc.Nodes[node.ID] = nil
end

-- Garbage collect unused nodes (run once at init time)
function ImGui.DockContextPruneUnusedSettingsNodes(ctx)
    local g = ctx
    local dc = ctx.DockContext
    IM_ASSERT(g.Windows.Size == 0)

    local pool = {}
    local function GetOrAdd(id)
        local d = pool[id]
        if not d then d = { CountWindows = 0, CountChildWindows = 0, CountChildNodes = 0, RootId = 0 }; pool[id] = d end
        return d
    end

    -- Count child nodes and compute RootID
    for _, settings in dc.NodesSettings:iter() do
        if pool[settings.ID] ~= nil then
            settings.ID = 0 -- Duplicate
        else
            local parent_data = (settings.ParentNodeId ~= 0) and pool[settings.ParentNodeId] or nil
            GetOrAdd(settings.ID).RootId = parent_data and parent_data.RootId or settings.ID
            if settings.ParentNodeId ~= 0 then
                local p = GetOrAdd(settings.ParentNodeId)
                p.CountChildNodes = p.CountChildNodes + 1
            end
        end
    end

    -- Count reference to dock ids from dockspaces
    -- We track the 'auto-DockNode <- manual-Window <- manual-DockSpace' in order to avoid 'auto-DockNode' being ditched by DockContextPruneUnusedSettingsNodes()
    for _, settings in dc.NodesSettings:iter() do
        if settings.ParentWindowId ~= 0 then
            local window_settings = ImGui.FindWindowSettingsByID(settings.ParentWindowId)
            if window_settings and window_settings.DockId ~= 0 then
                local data = pool[window_settings.DockId]
                if data then data.CountChildNodes = data.CountChildNodes + 1 end
            end
        end
    end

    -- Count reference to dock ids from window settings
    -- We guard against the possibility of an invalid .ini file (RootID may point to a missing node)
    for _, settings in g.SettingsWindows:iter() do
        local dock_id = settings.DockId
        if dock_id and dock_id ~= 0 then
            local data = pool[dock_id]
            if data then
                data.CountWindows = data.CountWindows + 1
                local data_root = (data.RootId == dock_id) and data or pool[data.RootId]
                if data_root then data_root.CountChildWindows = data_root.CountChildWindows + 1 end
            end
        end
    end

    -- Prune
    for _, settings in dc.NodesSettings:iter() do
        local data = pool[settings.ID]
        if data ~= nil and data.CountWindows <= 1 then
            local data_root = (settings.ID == data.RootId) and data or pool[data.RootId]
            local data_parent = (settings.ParentNodeId ~= 0) and pool[settings.ParentNodeId] or nil

            local remove = false
            remove = remove or (data.CountWindows == 1 and settings.ParentNodeId == 0 and data.CountChildNodes == 0 and bit32.band(settings.Flags, ImGuiDockNodeFlags.CentralNode) == 0) -- Floating root node with only 1 window
            remove = remove or (data.CountWindows == 0 and settings.ParentNodeId == 0 and data.CountChildNodes == 0) -- Leaf nodes with 0 window
            remove = remove or (data_root == nil or data_root.CountChildWindows == 0)
            if remove then
                DockSettingsRemoveNodeReferences({ settings.ID }, 1)
                settings.ID = 0
            elseif data_parent and data_parent.CountChildNodes == 1 then
                DockSettingsRenameNodeReferences(settings.ID, settings.ParentNodeId)
                settings.ID = 0
            end
        end
    end
end

--- @param node_settings_array table # 1-based array
function ImGui.DockContextBuildNodesFromSettings(ctx, node_settings_array, node_settings_count)
    -- Build nodes
    for node_n = 1, node_settings_count do
        local settings = node_settings_array[node_n]
        if settings.ID ~= 0 and ImGui.DockContextFindNodeByID(ctx, settings.ID) == nil then
            local node = ImGui.DockContextAddNode(ctx, settings.ID)
            node.ParentNode = (settings.ParentNodeId ~= 0) and ImGui.DockContextFindNodeByID(ctx, settings.ParentNodeId) or nil
            node.Pos = ImVec2(settings.Pos.x, settings.Pos.y)
            node.Size = ImVec2(settings.Size.x, settings.Size.y)
            node.SizeRef = ImVec2(settings.SizeRef.x, settings.SizeRef.y)
            node.AuthorityForPos = ImGuiDataAuthority.DockNode
            node.AuthorityForSize = ImGuiDataAuthority.DockNode
            node.AuthorityForViewport = ImGuiDataAuthority.DockNode
            if node.ParentNode and node.ParentNode.ChildNodes[0] == nil then
                node.ParentNode.ChildNodes[0] = node
            elseif node.ParentNode and node.ParentNode.ChildNodes[1] == nil then
                node.ParentNode.ChildNodes[1] = node
            end
            node.SelectedTabId = settings.SelectedTabId
            node.SplitAxis = settings.SplitAxis
            node:SetLocalFlags(bit32.band(settings.Flags, ImGuiDockNodeFlags.SavedFlagsMask_))

            -- Bind host window immediately if it already exist (in case of a rebuild)
            -- This is useful as the RootWindowForTitleBarHighlight links necessary to highlight the currently focused node requires node.HostWindow to be set.
            local root_node = ImGui.DockNodeGetRootNode(node)
            node.HostWindow = ImGui.FindWindowByName(DockNodeGetHostWindowTitle(root_node))
        end
    end
end

function ImGui.DockContextBuildAddWindowsToNodes(ctx, root_id)
    -- Rebind all windows to nodes (they can also lazily rebind but we'll have a visible glitch during the first frame)
    local g = ctx
    for _, window in g.Windows:iter() do
        if window.DockId ~= 0 and window.LastFrameActive >= g.FrameCount - 1 and window.DockNode == nil then
            local node = ImGui.DockContextFindNodeByID(ctx, window.DockId)
            IM_ASSERT(node ~= nil)   -- This should have been called after DockContextBuildNodesFromSettings()
            if root_id == 0 or ImGui.DockNodeGetRootNode(node).ID == root_id then
                ImGui.DockNodeAddWindow(node, window, true)
            end
        end
    end
end

-------------------------------------------------------------------------------
-- Docking: ImGuiDockContext Docking/Undocking functions
-------------------------------------------------------------------------------
-- - DockContextQueueDock()
-- - DockContextQueueUndockWindow()
-- - DockContextQueueUndockNode()
-- - DockContextQueueNotifyRemovedNode()
-- - DockContextProcessDock()
-- - DockContextProcessUndockWindow()
-- - DockContextProcessUndockNode()
-- - DockContextCalcDropPosForDocking()
-------------------------------------------------------------------------------

function ImGui.DockContextQueueDock(ctx, target, target_node, payload, split_dir, split_ratio, split_outer)
    IM_ASSERT(target ~= payload)
    local req = ImGuiDockRequest()
    req.Type = ImGuiDockRequestType.Dock
    req.DockTargetWindow = target
    req.DockTargetNode = target_node
    req.DockPayload = payload
    req.DockSplitDir = split_dir
    req.DockSplitRatio = split_ratio
    req.DockSplitOuter = split_outer
    ctx.DockContext.Requests:push_back(req)
end

function ImGui.DockContextQueueUndockWindow(ctx, window)
    local req = ImGuiDockRequest()
    req.Type = ImGuiDockRequestType.Undock
    req.UndockTargetWindow = window
    ctx.DockContext.Requests:push_back(req)
end

function ImGui.DockContextQueueUndockNode(ctx, node)
    local req = ImGuiDockRequest()
    req.Type = ImGuiDockRequestType.Undock
    req.UndockTargetNode = node
    ctx.DockContext.Requests:push_back(req)
end

function ImGui.DockContextQueueNotifyRemovedNode(ctx, node)
    for _, req in ctx.DockContext.Requests:iter() do
        if req.DockTargetNode == node then req.Type = ImGuiDockRequestType.None end
    end
end

function ImGui.DockContextProcessDock(ctx, req)
    IM_ASSERT((req.Type == ImGuiDockRequestType.Dock and req.DockPayload ~= nil) or (req.Type == ImGuiDockRequestType.Split and req.DockPayload == nil))
    IM_ASSERT(req.DockTargetWindow ~= nil or req.DockTargetNode ~= nil)
    local g = ctx

    local payload_window = req.DockPayload     -- Optional
    local target_window = req.DockTargetWindow
    local node = req.DockTargetNode

    -- Decide which Tab will be selected at the end of the operation
    local next_selected_id = 0
    local payload_node = nil
    if payload_window then
        payload_node = payload_window.DockNodeAsHost
        payload_window.DockNodeAsHost = nil -- Important to clear this as the node will have its life as a child which might be merged/deleted later.
        if payload_node and payload_node:IsLeafNode() then
            next_selected_id = (payload_node.TabBar.NextSelectedTabId ~= 0) and payload_node.TabBar.NextSelectedTabId or payload_node.TabBar.SelectedTabId
        end
        if payload_node == nil then next_selected_id = payload_window.TabId end
    end

    -- FIXME-DOCK: When we are trying to dock an existing single-window node into a loose window, transfer Node ID as well
    -- When processing an interactive split, usually LastFrameAlive will be < g.FrameCount. But DockBuilder operations can make it ==.
    if node then IM_ASSERT(node.LastFrameAlive <= g.FrameCount) end
    if node and target_window and node == target_window.DockNodeAsHost then
        IM_ASSERT(node.Windows.Size > 0 or node:IsSplitNode() or node:IsCentralNode())
    end

    -- Create new node and add existing window to it
    if node == nil then
        node = ImGui.DockContextAddNode(ctx, 0)
        node.Pos = ImVec2(target_window.Pos.x, target_window.Pos.y)
        node.Size = ImVec2(target_window.Size.x, target_window.Size.y)
        if target_window.DockNodeAsHost == nil then
            ImGui.DockNodeAddWindow(node, target_window, true)
            local t0 = node.TabBar.Tabs.Data[1]
            t0.Flags = bit32.band(t0.Flags, bit32.bnot(ImGuiTabItemFlags.Unsorted))
            target_window.DockIsActive = true
        end
    end

    local split_dir = req.DockSplitDir
    if split_dir ~= ImGuiDir.None then
        -- Split into two, one side will be our payload node unless we are dropping a loose window
        local split_axis = (split_dir == ImGuiDir.Left or split_dir == ImGuiDir.Right) and ImGuiAxis.X or ImGuiAxis.Y
        local split_inheritor_child_idx = (split_dir == ImGuiDir.Left or split_dir == ImGuiDir.Up) and 1 or 0 -- Current contents will be moved to the opposite side
        local split_ratio = req.DockSplitRatio
        ImGui.DockNodeTreeSplit(ctx, node, split_axis, split_inheritor_child_idx, split_ratio, payload_node)  -- payload_node may be nil here!
        local new_node = node.ChildNodes[bit32.bxor(split_inheritor_child_idx, 1)]
        new_node.HostWindow = node.HostWindow
        node = new_node
    end
    node:SetLocalFlags(bit32.band(node.LocalFlags, bit32.bnot(ImGuiDockNodeFlags.HiddenTabBar)))

    if node ~= payload_node then
        -- Create tab bar before we call DockNodeMoveWindows (which would attempt to move the old tab-bar, which would lead us to payload tabs wrongly appearing before target tabs!)
        if node.Windows.Size > 0 and node.TabBar == nil then
            ImGui.DockNodeAddTabBar(node)
            for n = 1, node.Windows.Size do
                ImGui.TabBarAddTab(node.TabBar, ImGuiTabItemFlags.None, node.Windows.Data[n])
            end
        end

        if payload_node ~= nil then
            -- Transfer full payload node (with 1+ child windows or child nodes)
            if payload_node:IsSplitNode() then
                if node.Windows.Size > 0 then
                    -- We can dock a split payload into a node that already has windows _only_ if our payload is a node tree with a single visible node.
                    -- In this situation, we move the windows of the target node into the currently visible node of the payload.
                    -- This allows us to preserve some of the underlying dock tree settings nicely.
                    IM_ASSERT(payload_node.OnlyNodeWithWindows ~= nil) -- The docking should have been blocked by DockNodePreviewDockSetup() early on and never submitted.
                    local visible_node = payload_node.OnlyNodeWithWindows
                    if visible_node.TabBar then IM_ASSERT(visible_node.TabBar.Tabs.Size > 0) end
                    ImGui.DockNodeMoveWindows(node, visible_node)
                    ImGui.DockNodeMoveWindows(visible_node, node)
                    DockSettingsRenameNodeReferences(node.ID, visible_node.ID)
                end
                if node:IsCentralNode() then
                    -- Central node property needs to be moved to a leaf node, pick the last focused one.
                    -- FIXME-DOCK: If we had to transfer other flags here, what would the policy be?
                    local last_focused_node = ImGui.DockContextFindNodeByID(ctx, payload_node.LastFocusedNodeId)
                    IM_ASSERT(last_focused_node ~= nil)
                    local last_focused_root_node = ImGui.DockNodeGetRootNode(last_focused_node)
                    IM_ASSERT(last_focused_root_node == ImGui.DockNodeGetRootNode(payload_node))
                    last_focused_node:SetLocalFlags(bit32.bor(last_focused_node.LocalFlags, ImGuiDockNodeFlags.CentralNode))
                    node:SetLocalFlags(bit32.band(node.LocalFlags, bit32.bnot(ImGuiDockNodeFlags.CentralNode)))
                    last_focused_root_node.CentralNode = last_focused_node
                end

                IM_ASSERT(node.Windows.Size == 0)
                ImGui.DockNodeMoveChildNodes(node, payload_node)
            else
                local payload_dock_id = payload_node.ID
                ImGui.DockNodeMoveWindows(node, payload_node)
                DockSettingsRenameNodeReferences(payload_dock_id, node.ID)
            end
            ImGui.DockContextRemoveNode(ctx, payload_node, true)
        elseif payload_window then
            -- Transfer single window
            local payload_dock_id = payload_window.DockId
            node.VisibleWindow = payload_window
            ImGui.DockNodeAddWindow(node, payload_window, true)
            if payload_dock_id ~= 0 then
                DockSettingsRenameNodeReferences(payload_dock_id, node.ID)
            end
        end
    else
        -- When docking a floating single window node we want to reevaluate auto-hiding of the tab bar
        node.WantHiddenTabBarUpdate = true
    end

    -- Update selection immediately
    local tab_bar = node.TabBar
    if tab_bar then tab_bar.NextSelectedTabId = next_selected_id end
    ImGui.MarkIniSettingsDirty()
end

-- Problem:
--   Undocking a large (~full screen) window would leave it so large that the bottom right sizing corner would more
--   than likely be off the screen and the window would be hard to resize to fit on screen. This can be particularly problematic
--   with 'ConfigWindowsMoveFromTitleBarOnly=true' and/or with 'ConfigWindowsResizeFromEdges=false' as well (the later can be
--   due to missing ImGuiBackendFlags.HasMouseCursors backend flag).
-- Solution:
--   When undocking a window we currently force its maximum size to 90% of the host viewport.
-- Reevaluate this when we implement preserving docked/undocked size ("docking_wip/undocked_size" branch).
local function FixLargeWindowsWhenUndocking(size, ref_viewport)
    if ref_viewport == nil then return size end
    local max_size = ImTrunc(ref_viewport.WorkSize * 0.90)
    return ImVec2(ImMin(size.x, max_size.x), ImMin(size.y, max_size.y))
end

function ImGui.DockContextProcessUndockWindow(ctx, window, clear_persistent_docking_ref)
    if clear_persistent_docking_ref == nil then clear_persistent_docking_ref = true end -- C++ default argument
    if window.DockNode then
        ImGui.DockNodeRemoveWindow(window.DockNode, window, clear_persistent_docking_ref and 0 or window.DockId)
    else
        window.DockId = 0
    end
    window.Collapsed = false
    window.DockIsActive = false
    window.DockNodeIsVisible = false
    window.DockTabIsVisible = false
    local sz = FixLargeWindowsWhenUndocking(window.SizeFull, window.Viewport)
    ImVec2_Copy(window.Size, sz)
    ImVec2_Copy(window.SizeFull, sz)
    ImGui.MarkIniSettingsDirty()
end

function ImGui.DockContextProcessUndockNode(ctx, node)
    IM_ASSERT(node:IsLeafNode())
    IM_ASSERT(node.Windows.Size >= 1)

    if node:IsRootNode() or node:IsCentralNode() then
        -- In the case of a root node or central node, the node will have to stay in place. Create a new node to receive the payload.
        local new_node = ImGui.DockContextAddNode(ctx, 0)
        new_node.Pos = ImVec2(node.Pos.x, node.Pos.y)
        new_node.Size = ImVec2(node.Size.x, node.Size.y)
        new_node.SizeRef = ImVec2(node.SizeRef.x, node.SizeRef.y)
        ImGui.DockNodeMoveWindows(new_node, node)
        DockSettingsRenameNodeReferences(node.ID, new_node.ID)
        node = new_node
    else
        -- Otherwise extract our node and merge our sibling back into the parent node.
        IM_ASSERT(node.ParentNode.ChildNodes[0] == node or node.ParentNode.ChildNodes[1] == node)
        local index_in_parent = (node.ParentNode.ChildNodes[0] == node) and 0 or 1
        node.ParentNode.ChildNodes[index_in_parent] = nil
        ImGui.DockNodeTreeMerge(ctx, node.ParentNode, node.ParentNode.ChildNodes[bit32.bxor(index_in_parent, 1)])
        node.ParentNode.AuthorityForViewport = ImGuiDataAuthority.Window -- The node that stays in place keeps the viewport, so our newly dragged out node will create a new viewport
        node.ParentNode = nil
    end
    for _, window in node.Windows:iter() do
        window.Flags = bit32.band(window.Flags, bit32.bnot(ImGuiWindowFlags.ChildWindow))
        if window.ParentWindow then window.ParentWindow.DC.ChildWindows:find_erase(window) end
        ImGui.UpdateWindowParentAndRootLinks(window, window.Flags, nil)
    end
    node.AuthorityForPos = ImGuiDataAuthority.DockNode
    node.AuthorityForSize = ImGuiDataAuthority.DockNode
    node.Size = FixLargeWindowsWhenUndocking(node.Size, node.Windows.Data[1].Viewport)
    node.WantMouseMove = true
    ImGui.MarkIniSettingsDirty()
end

-- This is mostly used for automation.
--- @return bool ok, ImVec2? out_pos
function ImGui.DockContextCalcDropPosForDocking(target, target_node, payload_window, payload_node, split_dir, split_outer)
    if target ~= nil and target_node == nil then target_node = target.DockNode end

    -- In DockNodePreviewDockSetup() for a root central node instead of showing both "inner" and "outer" drop rects
    -- (which would be functionally identical) we only show the outer one. Reflect this here.
    if target_node and target_node.ParentNode == nil and target_node:IsCentralNode() and split_dir ~= ImGuiDir.None then
        split_outer = true
    end
    local split_data = ImGuiDockPreviewData()
    ImGui.DockNodePreviewDockSetup(target, target_node, payload_window, payload_node, split_data, false, split_outer)
    local r = split_data.DropRectsDraw[split_dir + 1]
    if IsRectInverted(r) then return false, nil end
    return true, r:GetCenter()
end

-------------------------------------------------------------------------------
-- Docking: ImGuiDockNode
-------------------------------------------------------------------------------
-- - DockNodeGetTabOrder()
-- - DockNodeAddWindow()
-- - DockNodeRemoveWindow()
-- - DockNodeMoveChildNodes()
-- - DockNodeMoveWindows()
-- - DockNodeApplyPosSizeToWindows()
-- - DockNodeHideHostWindow()
-- - ImGuiDockNodeFindInfoResults
-- - DockNodeFindInfo()
-- - DockNodeFindWindowByID()
-- - DockNodeUpdateFlagsAndCollapse()
-- - DockNodeUpdateHasCentralNodeFlag()
-- - DockNodeUpdateVisibleFlag()
-- - DockNodeStartMouseMovingWindow()
-- - DockNodeUpdate()
-- - DockNodeUpdateWindowMenu()
-- - DockNodeBeginAmendTabBar()
-- - DockNodeEndAmendTabBar()
-- - DockNodeUpdateTabBar()
-- - DockNodeAddTabBar()
-- - DockNodeRemoveTabBar()
-- - DockNodeIsDropAllowedOne()
-- - DockNodeIsDropAllowed()
-- - DockNodeCalcTabBarLayout()
-- - DockNodeCalcSplitRects()
-- - DockNodeCalcDropRectsAndTestMousePos()
-- - DockNodePreviewDockSetup()
-- - DockNodePreviewDockRender()
-------------------------------------------------------------------------------

function ImGui.DockNodeGetTabOrder(window)
    local tab_bar = window.DockNode.TabBar
    if tab_bar == nil then return -1 end
    local tab = ImGui.TabBarFindTabByID(tab_bar, window.TabId)
    return tab and ImGui.TabBarGetTabOrder(tab_bar, tab) or -1
end

local function DockNodeHideWindowDuringHostWindowCreation(window)
    window.Hidden = true
    window.HiddenFramesCanSkipItems = window.Active and 1 or 2
end

function ImGui.DockNodeAddWindow(node, window, add_to_tab_bar)
    if window.DockNode then
        -- Can overwrite an existing window.DockNode (e.g. pointing to a disabled DockSpace node)
        IM_ASSERT(window.DockNode.ID ~= node.ID)
        ImGui.DockNodeRemoveWindow(window.DockNode, window, 0)
    end
    IM_ASSERT(window.DockNode == nil or window.DockNodeAsHost == nil)

    -- If more than 2 windows appeared on the same frame leading to the creation of a new hosting window,
    -- we'll hide windows until the host window is ready. Hide the 1st window after its been output (so it is not visible for one frame).
    -- We will call DockNodeHideWindowDuringHostWindowCreation() on ourselves in Begin()
    if node.HostWindow == nil and node.Windows.Size == 1 and node.Windows.Data[1].WasActive == false then
        DockNodeHideWindowDuringHostWindowCreation(node.Windows.Data[1])
    end

    node.Windows:push_back(window)
    node.WantHiddenTabBarUpdate = true
    window.DockNode = node
    window.DockId = node.ID
    window.DockIsActive = (node.Windows.Size > 1)
    window.DockTabWantClose = false

    -- When reactivating a node with one or two loose window, the window pos/size/viewport are authoritative over the node storage.
    -- In particular it is important we init the viewport from the first window so we don't create two viewports and drop one.
    if node.HostWindow == nil and node:IsFloatingNode() then
        if node.AuthorityForPos == ImGuiDataAuthority.Auto then node.AuthorityForPos = ImGuiDataAuthority.Window end
        if node.AuthorityForSize == ImGuiDataAuthority.Auto then node.AuthorityForSize = ImGuiDataAuthority.Window end
        if node.AuthorityForViewport == ImGuiDataAuthority.Auto then node.AuthorityForViewport = ImGuiDataAuthority.Window end
    end

    -- Add to tab bar if requested
    if add_to_tab_bar then
        if node.TabBar == nil then
            ImGui.DockNodeAddTabBar(node)
            node.TabBar.SelectedTabId = node.SelectedTabId
            node.TabBar.NextSelectedTabId = node.SelectedTabId

            -- Add existing windows
            for n = 1, node.Windows.Size - 1 do
                ImGui.TabBarAddTab(node.TabBar, ImGuiTabItemFlags.None, node.Windows.Data[n])
            end
        end
        ImGui.TabBarAddTab(node.TabBar, ImGuiTabItemFlags.Unsorted, window)
    end

    ImGui.DockNodeUpdateVisibleFlag(node)

    -- Update this without waiting for the next time we Begin() in the window, so our host window will have the proper title bar color on its first frame.
    if node.HostWindow then
        ImGui.UpdateWindowParentAndRootLinks(window, bit32.bor(window.Flags, ImGuiWindowFlags.ChildWindow), node.HostWindow)
    end
end

function ImGui.DockNodeRemoveWindow(node, window, save_dock_id)
    IM_ASSERT(window.DockNode == node)
    -- IM_ASSERT(window.RootWindowDockTree == node.HostWindow)
    -- IM_ASSERT(window.LastFrameActive < g.FrameCount)    -- We may call this from Begin()
    IM_ASSERT(save_dock_id == 0 or save_dock_id == node.ID)

    window.DockNode = nil
    window.DockIsActive = false
    window.DockTabWantClose = false
    window.DockId = save_dock_id
    window.Flags = bit32.band(window.Flags, bit32.bnot(ImGuiWindowFlags.ChildWindow))
    if window.ParentWindow then window.ParentWindow.DC.ChildWindows:find_erase(window) end
    ImGui.UpdateWindowParentAndRootLinks(window, window.Flags, nil) -- Update immediately

    if node.HostWindow and node.HostWindow.ViewportOwned then
        -- When undocking from a user interaction this will always run in NewFrame() and have not much effect.
        -- But mid-frame, if we clear viewport we need to mark window as hidden as well.
        window.Viewport = nil
        window.ViewportId = 0
        window.ViewportOwned = false
        window.Hidden = true
    end

    -- Remove window
    local idx = node.Windows:find_index(window)
    IM_ASSERT(idx ~= nil)
    node.Windows:erase(idx)
    if node.VisibleWindow == window then node.VisibleWindow = nil end

    -- Remove tab and possibly tab bar
    node.WantHiddenTabBarUpdate = true
    if node.TabBar then
        ImGui.TabBarRemoveTab(node.TabBar, window.TabId)
        local tab_count_threshold_for_tab_bar = node:IsCentralNode() and 1 or 2
        if node.Windows.Size < tab_count_threshold_for_tab_bar then
            ImGui.DockNodeRemoveTabBar(node)
        end
    end

    if node.Windows.Size == 0 and not node:IsCentralNode() and not node:IsDockSpace() and window.DockId ~= node.ID then
        -- Automatic dock node delete themselves if they are not holding at least one tab
        ImGui.DockContextRemoveNode(ImGui.GetCurrentContext(), node, true)
        return
    end

    if node.Windows.Size == 1 and not node:IsCentralNode() and node.HostWindow then
        local remaining_window = node.Windows.Data[1]
        -- Note: we used to transport viewport ownership here.
        remaining_window.Collapsed = node.HostWindow.Collapsed
    end

    -- Update visibility immediately is required so the DockNodeUpdateRemoveInactiveChilds() processing can reflect changes up the tree
    ImGui.DockNodeUpdateVisibleFlag(node)
end

function ImGui.DockNodeMoveChildNodes(dst_node, src_node)
    IM_ASSERT(dst_node.Windows.Size == 0)
    dst_node.ChildNodes[0] = src_node.ChildNodes[0]
    dst_node.ChildNodes[1] = src_node.ChildNodes[1]
    if dst_node.ChildNodes[0] then dst_node.ChildNodes[0].ParentNode = dst_node end
    if dst_node.ChildNodes[1] then dst_node.ChildNodes[1].ParentNode = dst_node end
    dst_node.SplitAxis = src_node.SplitAxis
    dst_node.SizeRef = ImVec2(src_node.SizeRef.x, src_node.SizeRef.y)
    src_node.ChildNodes[0] = nil
    src_node.ChildNodes[1] = nil
end

function ImGui.DockNodeMoveWindows(dst_node, src_node)
    -- Insert tabs in the same orders as currently ordered (node.Windows isn't ordered)
    IM_ASSERT(src_node and dst_node and dst_node ~= src_node)
    local src_tab_bar = src_node.TabBar
    if src_tab_bar ~= nil then IM_ASSERT(src_node.Windows.Size <= src_node.TabBar.Tabs.Size) end

    -- If the dst_node is empty we can just move the entire tab bar (to preserve selection, scrolling, etc.)
    local move_tab_bar = (src_tab_bar ~= nil) and (dst_node.TabBar == nil)
    if move_tab_bar then
        dst_node.TabBar = src_node.TabBar
        src_node.TabBar = nil
    end

    -- Tab order is not important here, it is preserved by sorting in DockNodeUpdateTabBar().
    -- Snapshot: DockNodeAddWindow() won't touch src_node.Windows since window.DockNode is cleared first
    local windows = {}
    for i = 1, src_node.Windows.Size do windows[i] = src_node.Windows.Data[i] end
    for _, window in ipairs(windows) do
        window.DockNode = nil
        window.DockIsActive = false
        ImGui.DockNodeAddWindow(dst_node, window, not move_tab_bar)
    end
    src_node.Windows:clear()

    if not move_tab_bar and src_node.TabBar then
        if dst_node.TabBar then dst_node.TabBar.SelectedTabId = src_node.TabBar.SelectedTabId end
        ImGui.DockNodeRemoveTabBar(src_node)
    end
end

function ImGui.DockNodeApplyPosSizeToWindows(node)
    for _, window in node.Windows:iter() do
        ImGui.SetWindowPos(window, node.Pos, ImGuiCond.Always) -- We don't assign directly to Pos because it can break the calculation of SizeContents on next frame
        ImGui.SetWindowSize(window, node.Size, ImGuiCond.Always)
    end
end

function ImGui.DockNodeHideHostWindow(node)
    if node.HostWindow then
        if node.HostWindow.DockNodeAsHost == node then node.HostWindow.DockNodeAsHost = nil end
        node.HostWindow = nil
    end
    if node.Windows.Size == 1 then
        node.VisibleWindow = node.Windows.Data[1]
        node.Windows.Data[1].DockIsActive = false
    end
    if node.TabBar then ImGui.DockNodeRemoveTabBar(node) end
end

-- Search function called once by root node in DockNodeUpdate()
local function DockNodeFindInfo(node, info)
    if node.Windows.Size > 0 then
        if info.FirstNodeWithWindows == nil then info.FirstNodeWithWindows = node end
        info.CountNodesWithWindows = info.CountNodesWithWindows + 1
    end
    if node:IsCentralNode() then
        IM_ASSERT(info.CentralNode == nil) -- Should be only one
        IM_ASSERT(node:IsLeafNode(), "If you get this assert: please submit .ini file + repro of actions leading to this.")
        info.CentralNode = node
    end
    if info.CountNodesWithWindows > 1 and info.CentralNode ~= nil then return end
    if node.ChildNodes[0] then DockNodeFindInfo(node.ChildNodes[0], info) end
    if node.ChildNodes[1] then DockNodeFindInfo(node.ChildNodes[1], info) end
end

function ImGui.DockNodeFindWindowByID(node, id)
    IM_ASSERT(id ~= 0)
    for _, window in node.Windows:iter() do
        if window.ID == id then return window end
    end
    return nil
end

-- - Remove inactive windows/nodes.
-- - Update visibility flag.
function ImGui.DockNodeUpdateFlagsAndCollapse(node)
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(node.ParentNode == nil or node.ParentNode.ChildNodes[0] == node or node.ParentNode.ChildNodes[1] == node)

    -- Inherit most flags
    if node.ParentNode then
        node.SharedFlags = bit32.band(node.ParentNode.SharedFlags, ImGuiDockNodeFlags.SharedFlagsInheritMask_)
    end

    -- Recurse into children
    -- There is the possibility that one of our child becoming empty will delete itself and moving its sibling contents into 'node'.
    -- If 'node.ChildNode[0]' delete itself, then 'node.ChildNode[1].Windows' will be moved into 'node'
    -- If 'node.ChildNode[1]' delete itself, then 'node.ChildNode[0].Windows' will be moved into 'node' and the "remove inactive windows" loop will have run twice on those windows (harmless)
    node.HasCentralNodeChild = false
    if node.ChildNodes[0] then ImGui.DockNodeUpdateFlagsAndCollapse(node.ChildNodes[0]) end
    if node.ChildNodes[1] then ImGui.DockNodeUpdateFlagsAndCollapse(node.ChildNodes[1]) end

    -- Remove inactive windows, collapse nodes
    -- Merge node flags overrides stored in windows
    node.LocalFlagsInWindows = ImGuiDockNodeFlags.None
    local window_n = 1
    while window_n <= node.Windows.Size do
        local window = node.Windows.Data[window_n]
        IM_ASSERT(window.DockNode == node)

        local node_was_active = (node.LastFrameActive + 1 == g.FrameCount)
        local remove = false
        remove = remove or (node_was_active and (window.WasActive == false)) -- Can't use 'window.LastFrameActive + 1 < g.FrameCount'. (see #9151)
        remove = remove or (node_was_active and (node.WantCloseAll or node.WantCloseTabId == window.TabId) and window.HasCloseButton and bit32.band(window.Flags, ImGuiWindowFlags.UnsavedDocument) == 0)  -- Submit all _expected_ closure from last frame
        remove = remove or window.DockTabWantClose
        if remove then
            window.DockTabWantClose = false
            if node.Windows.Size == 1 and not node:IsCentralNode() then
                ImGui.DockNodeHideHostWindow(node)
                node.State = ImGuiDockNodeState.HostWindowHiddenBecauseSingleWindow
                ImGui.DockNodeRemoveWindow(node, window, node.ID) -- Will delete the node so it'll be invalid on return
                return
            end
            ImGui.DockNodeRemoveWindow(node, window, node.ID)
        else
            -- FIXME-DOCKING: Missing policies for conflict resolution, hence the "Experimental" tag on this.
            -- node.LocalFlagsInWindow = bit32.band(node.LocalFlagsInWindow, bit32.bnot(window.WindowClass.DockNodeFlagsOverrideClear))
            node.LocalFlagsInWindows = bit32.bor(node.LocalFlagsInWindows, window.WindowClass.DockNodeFlagsOverrideSet)
            window_n = window_n + 1
        end
    end
    node:UpdateMergedFlags()

    -- Auto-hide tab bar option
    local node_flags = node.MergedFlags
    if node.WantHiddenTabBarUpdate and node.Windows.Size == 1 and bit32.band(node_flags, ImGuiDockNodeFlags.AutoHideTabBar) ~= 0 and not node:IsHiddenTabBar() then
        node.WantHiddenTabBarToggle = true
    end
    node.WantHiddenTabBarUpdate = false

    -- Cancel toggling if we know our tab bar is enforced to be hidden at all times
    if node.WantHiddenTabBarToggle and node.VisibleWindow and bit32.band(node.VisibleWindow.WindowClass.DockNodeFlagsOverrideSet, ImGuiDockNodeFlags.HiddenTabBar) ~= 0 then
        node.WantHiddenTabBarToggle = false
    end

    -- Apply toggles at a single point of the frame (here!)
    local prev_local_flags = node.LocalFlags
    if node.Windows.Size > 1 then
        node:SetLocalFlags(bit32.band(node.LocalFlags, bit32.bnot(ImGuiDockNodeFlags.HiddenTabBar)))
    elseif node.WantHiddenTabBarToggle then
        node:SetLocalFlags(bit32.bxor(node.LocalFlags, ImGuiDockNodeFlags.HiddenTabBar))
    end
    if bit32.band(bit32.bxor(node.LocalFlags, prev_local_flags), ImGuiDockNodeFlags.SavedFlagsMask_) ~= 0 then
        ImGui.MarkIniSettingsDirty() -- Bit flaky to only do this here. Perhaps compare node flags every frame? #9380
    end
    node.WantHiddenTabBarToggle = false

    ImGui.DockNodeUpdateVisibleFlag(node)
end

-- This is rarely called as DockNodeUpdateForRootNode() generally does it most frames.
function ImGui.DockNodeUpdateHasCentralNodeChild(node)
    node.HasCentralNodeChild = false
    if node.ChildNodes[0] then ImGui.DockNodeUpdateHasCentralNodeChild(node.ChildNodes[0]) end
    if node.ChildNodes[1] then ImGui.DockNodeUpdateHasCentralNodeChild(node.ChildNodes[1]) end
    if node:IsRootNode() then
        local mark_node = node.CentralNode
        while mark_node do
            mark_node.HasCentralNodeChild = true
            mark_node = mark_node.ParentNode
        end
    end
end

function ImGui.DockNodeUpdateVisibleFlag(node)
    -- Update visibility flag
    local is_visible = (node.ParentNode == nil) and node:IsDockSpace() or node:IsCentralNode()
    is_visible = is_visible or (node.Windows.Size > 0)
    is_visible = is_visible or (node.ChildNodes[0] ~= nil and node.ChildNodes[0].IsVisible)
    is_visible = is_visible or (node.ChildNodes[1] ~= nil and node.ChildNodes[1].IsVisible)
    node.IsVisible = is_visible and true or false
end

function ImGui.DockNodeStartMouseMovingWindow(node, window)
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(node.WantMouseMove == true)
    ImGui.StartMouseMovingWindow(window)
    ImVec2_Copy(g.ActiveIdClickOffset, g.IO.MouseClickedPos[0] - node.Pos)
    g.MovingWindow = window -- If we are docked into a non moveable root window, StartMouseMovingWindow() won't set g.MovingWindow. Override that decision.
    node.WantMouseMove = false
end

-- Update CentralNode, OnlyNodeWithWindows, LastFocusedNodeID. Copy window class.
function ImGui.DockNodeUpdateForRootNode(node)
    ImGui.DockNodeUpdateFlagsAndCollapse(node)

    -- - Setup central node pointers
    -- - Find if there's only a single visible window in the hierarchy (in which case we need to display a regular title bar -> FIXME-DOCK: that last part is not done yet!)
    -- Cannot merge this with DockNodeUpdateFlagsAndCollapse() because FirstNodeWithWindows is found after window removal and child collapsing
    local info = { CentralNode = nil, FirstNodeWithWindows = nil, CountNodesWithWindows = 0 }
    DockNodeFindInfo(node, info)
    node.CentralNode = info.CentralNode
    node.OnlyNodeWithWindows = (info.CountNodesWithWindows == 1) and info.FirstNodeWithWindows or nil
    node.CountNodeWithWindows = info.CountNodesWithWindows
    if node.LastFocusedNodeId == 0 and info.FirstNodeWithWindows ~= nil then
        node.LastFocusedNodeId = info.FirstNodeWithWindows.ID
    end

    -- Copy the window class from of our first window so it can be used for proper dock filtering.
    -- When node has mixed windows, prioritize the class with the most constraint (DockingAllowUnclassed = false) as the reference to copy.
    -- FIXME-DOCK: We don't recurse properly, this code could be reworked to work from DockNodeUpdateScanRec.
    local first_node_with_windows = info.FirstNodeWithWindows
    if first_node_with_windows then
        node.WindowClass = first_node_with_windows.Windows.Data[1].WindowClass
        for n = 2, first_node_with_windows.Windows.Size do
            if first_node_with_windows.Windows.Data[n].WindowClass.DockingAllowUnclassed == false then
                node.WindowClass = first_node_with_windows.Windows.Data[n].WindowClass
                break
            end
        end
    end

    local mark_node = node.CentralNode
    while mark_node do
        mark_node.HasCentralNodeChild = true
        mark_node = mark_node.ParentNode
    end
end

local function DockNodeSetupHostWindow(node, host_window)
    -- Remove ourselves from any previous different host window
    -- This can happen if a user mistakenly does (see #4295 for details):
    --  - N+0: DockBuilderAddNode(id, 0)    -- missing ImGuiDockNodeFlags.DockSpace
    --  - N+1: NewFrame()                   -- will create floating host window for that node
    --  - N+1: DockSpace(id)                -- requalify node as dockspace, moving host window
    if node.HostWindow and node.HostWindow ~= host_window and node.HostWindow.DockNodeAsHost == node then
        node.HostWindow.DockNodeAsHost = nil
    end
    host_window.DockNodeAsHost = node
    node.HostWindow = host_window
end

function ImGui.DockNodeUpdate(node)
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(node.LastFrameActive ~= g.FrameCount)
    node.LastFrameAlive = g.FrameCount
    node.IsBgDrawnThisFrame = false

    node.CentralNode = nil
    node.OnlyNodeWithWindows = nil
    if node:IsRootNode() then ImGui.DockNodeUpdateForRootNode(node) end

    -- Remove tab bar if not needed
    if node.TabBar and node:IsNoTabBar() then ImGui.DockNodeRemoveTabBar(node) end

    -- Early out for hidden root dock nodes (when all DockId references are in inactive windows, or there is only 1 floating window holding on the DockId)
    local want_to_hide_host_window = false
    if node:IsFloatingNode() then
        if node.Windows.Size <= 1 and node:IsLeafNode() then
            if not g.IO.ConfigDockingAlwaysTabBar and (node.Windows.Size == 0 or not node.Windows.Data[1].WindowClass.DockingAlwaysTabBar) then
                want_to_hide_host_window = true
            end
        end
        if node.CountNodeWithWindows == 0 then want_to_hide_host_window = true end
    end
    if want_to_hide_host_window then
        if node.Windows.Size == 1 then
            -- Floating window pos/size is authoritative
            local single_window = node.Windows.Data[1]
            node.Pos = ImVec2(single_window.Pos.x, single_window.Pos.y)
            node.Size = ImVec2(single_window.SizeFull.x, single_window.SizeFull.y)
            node.AuthorityForPos = ImGuiDataAuthority.Window
            node.AuthorityForSize = ImGuiDataAuthority.Window
            node.AuthorityForViewport = ImGuiDataAuthority.Window

            -- Transfer focus immediately so when we revert to a regular window it is immediately selected
            if node.HostWindow and g.NavWindow == node.HostWindow then
                ImGui.FocusWindow(single_window)
            end
            if node.HostWindow then
                single_window.Viewport = node.HostWindow.Viewport
                single_window.ViewportId = node.HostWindow.ViewportId
            end
            node.RefViewportId = single_window.ViewportId or 0
        end

        ImGui.DockNodeHideHostWindow(node)
        node.State = ImGuiDockNodeState.HostWindowHiddenBecauseSingleWindow
        node.WantCloseAll = false
        node.WantCloseTabId = 0
        node.HasCloseButton = false
        node.HasWindowMenuButton = false
        node.LastFrameActive = g.FrameCount

        if node.WantMouseMove and node.Windows.Size == 1 then
            ImGui.DockNodeStartMouseMovingWindow(node, node.Windows.Data[1])
        end
        return
    end

    -- In some circumstance we will defer creating the host window (so everything will be kept hidden),
    -- while the expected visible window is resizing itself.
    -- This is important for first-time (no ini settings restored) single window when io.ConfigDockingAlwaysTabBar is enabled,
    -- otherwise the node ends up using the minimum window size. Effectively those windows will take an extra frame to show up:
    --   N+0: Begin(): window created (with no known size), node is created
    --   N+1: DockNodeUpdate(): node skip creating host window / Begin(): window size applied, not visible
    --   N+2: DockNodeUpdate(): node can create host window / Begin(): window becomes visible
    -- We could remove this frame if we could reliably calculate the expected window size during node update, before the Begin() code.
    -- It would require a generalization of CalcWindowExpectedSize(), probably extracting code away from Begin().
    -- In reality it isn't very important as user quickly ends up with size data in .ini file.
    if node.IsVisible and node.HostWindow == nil and node:IsFloatingNode() and node:IsLeafNode() then
        IM_ASSERT(node.Windows.Size > 0)
        local ref_window = nil
        -- Note that we prune single-window-node settings on .ini loading, so this is generally 0 for them!
        if node.SelectedTabId ~= 0 then ref_window = ImGui.DockNodeFindWindowByID(node, node.SelectedTabId) end
        if ref_window == nil then ref_window = node.Windows.Data[1] end
        if ref_window.AutoFitFramesX > 0 or ref_window.AutoFitFramesY > 0 then
            node.State = ImGuiDockNodeState.HostWindowHiddenBecauseWindowsAreResizing
            return
        end
    end

    local node_flags = node.MergedFlags

    -- Decide if the node will have a close button and a window menu button
    node.HasWindowMenuButton = (node.Windows.Size > 0) and bit32.band(node_flags, ImGuiDockNodeFlags.NoWindowMenuButton) == 0
    node.HasCloseButton = false
    for _, window in node.Windows:iter() do
        -- FIXME-DOCK: Setting DockIsActive here means that for single active window in a leaf node, DockIsActive will be cleared until the next Begin() call.
        node.HasCloseButton = node.HasCloseButton or window.HasCloseButton
        window.DockIsActive = (node.Windows.Size > 1)
    end
    if bit32.band(node_flags, ImGuiDockNodeFlags.NoCloseButton) ~= 0 or not g.Style.DockingNodeHasCloseButton then
        node.HasCloseButton = false
    end

    -- Bind or create host window
    local host_window = nil
    local beginned_into_host_window = false
    if node:IsDockSpace() then
        -- [Explicit root dockspace node]
        IM_ASSERT(node.HostWindow)
        host_window = node.HostWindow
    else
        -- [Automatic root or child nodes]
        if node:IsRootNode() and node.IsVisible then
            local ref_window = (node.Windows.Size > 0) and node.Windows.Data[1] or nil

            -- Sync Pos
            if node.AuthorityForPos == ImGuiDataAuthority.Window and ref_window then
                ImGui.SetNextWindowPos(ref_window.Pos)
            elseif node.AuthorityForPos == ImGuiDataAuthority.DockNode then
                ImGui.SetNextWindowPos(node.Pos)
            end

            -- Sync Size
            if node.AuthorityForSize == ImGuiDataAuthority.Window and ref_window then
                ImGui.SetNextWindowSize(ref_window.SizeFull)
            elseif node.AuthorityForSize == ImGuiDataAuthority.DockNode then
                ImGui.SetNextWindowSize(node.Size)
            end

            -- Sync Collapsed
            if node.AuthorityForSize == ImGuiDataAuthority.Window and ref_window then
                ImGui.SetNextWindowCollapsed(ref_window.Collapsed)
            end

            ImGui.SetNextWindowClass(node.WindowClass)

            -- Begin into the host window
            local window_label = DockNodeGetHostWindowTitle(node)
            local window_flags = bit32.bor(ImGuiWindowFlags.NoScrollbar, ImGuiWindowFlags.NoScrollWithMouse, ImGuiWindowFlags.DockNodeHost)
            window_flags = bit32.bor(window_flags, ImGuiWindowFlags.NoFocusOnAppearing)
            window_flags = bit32.bor(window_flags, ImGuiWindowFlags.NoSavedSettings, ImGuiWindowFlags.NoNavFocus, ImGuiWindowFlags.NoCollapse)
            window_flags = bit32.bor(window_flags, ImGuiWindowFlags.NoTitleBar)

            ImGui.SetNextWindowBgAlpha(0.0) -- Don't set ImGuiWindowFlags.NoBackground because it disables borders
            ImGui.PushStyleVar(ImGuiStyleVar.WindowPadding, ImVec2(0, 0))
            ImGui.Begin(window_label, nil, window_flags)
            ImGui.PopStyleVar()
            beginned_into_host_window = true

            host_window = g.CurrentWindow
            DockNodeSetupHostWindow(node, host_window)
            ImVec2_Copy(host_window.DC.CursorPos, host_window.Pos)
            node.Pos = ImVec2(host_window.Pos.x, host_window.Pos.y)
            node.Size = ImVec2(host_window.Size.x, host_window.Size.y)

            -- We set ImGuiWindowFlags.NoFocusOnAppearing because we don't want the host window to take full focus (e.g. steal NavWindow)
            -- But we still it bring it to the front of display. There's no way to choose this precise behavior via window flags.
            -- One simple case to ponder if: window A has a toggle to create windows B/C/D. Dock B/C/D together, clear the toggle and enable it again.
            -- When reappearing B/C/D will request focus and be moved to the top of the display pile, but they are not linked to the dock host window
            -- during the frame they appear. The dock host window would keep its old display order, and the sorting in EndFrame would move B/C/D back
            -- after the dock host window, losing their top-most status.
            if node.HostWindow.Appearing then ImGui.BringWindowToDisplayFront(node.HostWindow) end

            node.AuthorityForPos = ImGuiDataAuthority.Auto
            node.AuthorityForSize = ImGuiDataAuthority.Auto
            node.AuthorityForViewport = ImGuiDataAuthority.Auto
        elseif node.ParentNode then
            host_window = node.ParentNode.HostWindow
            node.HostWindow = host_window
            node.AuthorityForPos = ImGuiDataAuthority.Auto
            node.AuthorityForSize = ImGuiDataAuthority.Auto
            node.AuthorityForViewport = ImGuiDataAuthority.Auto
        end
        if node.WantMouseMove and node.HostWindow then
            ImGui.DockNodeStartMouseMovingWindow(node, node.HostWindow)
        end
    end
    node.RefViewportId = 0 -- Clear when we have a host window

    -- Update focused node (the one whose title bar is highlight) within a node tree
    if node:IsSplitNode() then IM_ASSERT(node.TabBar == nil) end
    if node:IsRootNode() then
        local p_window = g.NavWindow and g.NavWindow.RootWindow or nil
        while p_window ~= nil and p_window.DockNode ~= nil do
            local p_node = ImGui.DockNodeGetRootNode(p_window.DockNode)
            if p_node == node then
                node.LastFocusedNodeId = p_window.DockNode.ID -- Note: not using root node ID!
                break
            end
            p_window = p_node.HostWindow and p_node.HostWindow.RootWindow or nil
        end
    end

    -- Register a hit-test hole in the window unless we are currently dragging a window that is compatible with our dockspace
    local central_node = node.CentralNode
    local central_node_hole = node:IsRootNode() and host_window ~= nil and bit32.band(node_flags, ImGuiDockNodeFlags.PassthruCentralNode) ~= 0 and central_node ~= nil and central_node:IsEmpty()
    local central_node_hole_register_hit_test_hole = central_node_hole
    if central_node_hole then
        local payload = ImGui.GetDragDropPayload()
        if payload and ImGuiPayload_IsDataType(payload, IMGUI_PAYLOAD_TYPE_WINDOW) and ImGui.DockNodeIsDropAllowed(host_window, payload.Data) then
            central_node_hole_register_hit_test_hole = false
        end
    end
    if central_node_hole_register_hit_test_hole then
        -- We add a little padding to match the "resize from edges" behavior and allow grabbing the splitter easily.
        -- (But we only add it if there's something else on the other side of the hole, otherwise for e.g. fullscreen
        -- covering passthru node we'd have a gap on the edge not covered by the hole)
        IM_ASSERT(node:IsDockSpace()) -- We cannot pass this flag without the DockSpace() api. Testing this because we also setup the hole in host_window.ParentNode
        local root_node = ImGui.DockNodeGetRootNode(central_node)
        local root_rect = ImRect(root_node.Pos, root_node.Pos + root_node.Size)
        local hole_rect = ImRect(central_node.Pos, central_node.Pos + central_node.Size)
        if hole_rect.Min.x > root_rect.Min.x then hole_rect.Min.x = hole_rect.Min.x + g.WindowsBorderHoverPadding end
        if hole_rect.Max.x < root_rect.Max.x then hole_rect.Max.x = hole_rect.Max.x - g.WindowsBorderHoverPadding end
        if hole_rect.Min.y > root_rect.Min.y then hole_rect.Min.y = hole_rect.Min.y + g.WindowsBorderHoverPadding end
        if hole_rect.Max.y < root_rect.Max.y then hole_rect.Max.y = hole_rect.Max.y - g.WindowsBorderHoverPadding end
        -- GetForegroundDrawList():AddRect(hole_rect.Min, hole_rect.Max, IM_COL32(255, 0, 0, 255))
        if central_node_hole and not IsRectInverted(hole_rect) then
            ImGui.SetWindowHitTestHole(host_window, hole_rect.Min, hole_rect.Max - hole_rect.Min)
            if host_window.ParentWindow then
                ImGui.SetWindowHitTestHole(host_window.ParentWindow, hole_rect.Min, hole_rect.Max - hole_rect.Min)
            end
        end
    end

    -- Update position/size, process and draw resizing splitters
    if node:IsRootNode() and host_window then
        ImGui.DockNodeTreeUpdatePosSize(node, host_window.Pos, host_window.Size)
        ImGui.PushStyleColor(ImGuiCol.Separator, g.Style.Colors[ImGuiCol.Border])
        ImGui.PushStyleColor(ImGuiCol.SeparatorActive, g.Style.Colors[ImGuiCol.ResizeGripActive])
        ImGui.PushStyleColor(ImGuiCol.SeparatorHovered, g.Style.Colors[ImGuiCol.ResizeGripHovered])
        ImGui.DockNodeTreeUpdateSplitter(node)
        ImGui.PopStyleColor(3)
    end

    -- Draw empty node background (currently can only be the Central Node)
    if host_window and node:IsEmpty() and node.IsVisible then
        host_window.DrawList:ChannelsSetCurrent(DOCKING_HOST_DRAW_CHANNEL_BG)
        node.LastBgColor = (bit32.band(node_flags, ImGuiDockNodeFlags.PassthruCentralNode) ~= 0) and 0 or ImGui.GetColorU32(ImGuiCol.DockingEmptyBg)
        if node.LastBgColor ~= 0 then
            host_window.DrawList:AddRectFilled(node.Pos, node.Pos + node.Size, node.LastBgColor)
        end
        node.IsBgDrawnThisFrame = true
    end

    -- Draw whole dockspace background if ImGuiDockNodeFlags.PassthruCentralNode if set.
    -- We need to draw a background at the root level if requested by ImGuiDockNodeFlags.PassthruCentralNode, but we will only know the correct pos/size
    -- _after_ processing the resizing splitters. So we are using the DrawList channel splitting facility to submit drawing primitives out of order!
    local render_dockspace_bg = node:IsRootNode() and host_window ~= nil and bit32.band(node_flags, ImGuiDockNodeFlags.PassthruCentralNode) ~= 0
    if render_dockspace_bg and node.IsVisible then
        host_window.DrawList:ChannelsSetCurrent(DOCKING_HOST_DRAW_CHANNEL_BG)
        if central_node_hole then
            ImGui.RenderRectFilledWithHole(host_window.DrawList, node:Rect(), central_node:Rect(), ImGui.GetColorU32(ImGuiCol.WindowBg), 0.0)
        else
            host_window.DrawList:AddRectFilled(node.Pos, node.Pos + node.Size, ImGui.GetColorU32(ImGuiCol.WindowBg), 0.0)
        end
    end

    -- Draw and populate Tab Bar
    if host_window then host_window.DrawList:ChannelsSetCurrent(DOCKING_HOST_DRAW_CHANNEL_FG) end
    if host_window and node.Windows.Size > 0 then
        ImGui.DockNodeUpdateTabBar(node, host_window)
    else
        node.WantCloseAll = false
        node.WantCloseTabId = 0
        node.IsFocused = false
    end
    if node.TabBar and node.TabBar.SelectedTabId ~= 0 then
        node.SelectedTabId = node.TabBar.SelectedTabId
    elseif node.Windows.Size > 0 then
        node.SelectedTabId = node.Windows.Data[1].TabId
    end

    -- Draw payload drop target
    if host_window and node.IsVisible then
        if node:IsRootNode() and (g.MovingWindow == nil or g.MovingWindow.RootWindowDockTree ~= host_window) then
            ImGui.BeginDockableDragDropTarget(host_window)
        end
    end

    -- We update this after DockNodeUpdateTabBar()
    node.LastFrameActive = g.FrameCount

    -- Recurse into children
    -- FIXME-DOCK FIXME-OPT: Should not need to recurse into children
    if host_window then
        if node.ChildNodes[0] then ImGui.DockNodeUpdate(node.ChildNodes[0]) end
        if node.ChildNodes[1] then ImGui.DockNodeUpdate(node.ChildNodes[1]) end

        -- Render outer borders last (after the tab bar)
        if node:IsRootNode() then ImGui.RenderWindowOuterBorders(host_window) end
    end

    -- End host window
    if beginned_into_host_window then ImGui.End() end
end

local GWindowDockStyleColors = {
    [0] = ImGuiCol.Text, ImGuiCol.TabHovered, ImGuiCol.Tab, ImGuiCol.TabSelected, ImGuiCol.TabSelectedOverline,
    ImGuiCol.TabDimmed, ImGuiCol.TabDimmedSelected, ImGuiCol.TabDimmedSelectedOverline, ImGuiCol.UnsavedMarker,
}
ImGui.GWindowDockStyleColors = GWindowDockStyleColors

-- Compare TabItem nodes given the last known DockOrder (will persist in .ini file as hint), used to sort tabs when multiple tabs are added on the same frame.
local function TabItemComparerByDockOrder(ta, tb)
    local a, b = ta.Window, tb.Window
    local ao = (a.DockOrder == -1) and INT_MAX or a.DockOrder
    local bo = (b.DockOrder == -1) and INT_MAX or b.DockOrder
    if ao ~= bo then return ao < bo end
    return a.BeginOrderWithinContext < b.BeginOrderWithinContext
end

-- Default handler for g.DockNodeWindowMenuHandler(): display the list of windows for a given dock-node.
-- This is exceptionally stored in a function pointer to also user applications to tweak this menu (undocumented)
-- Custom overrides may want to decorate, group, sort entries.
-- Please note those are internal structures: if you copy this expect occasional breakage.
-- (if you don't need to modify the "Tabs.Size == 1" behavior/path it is recommend you call this function in your handler)
function ImGui.DockNodeWindowMenuHandler_Default(ctx, node, tab_bar)
    if tab_bar.Tabs.Size == 1 then
        -- "Hide tab bar" option. Being one of our rare user-facing string we pull it from a table.
        if ImGui.MenuItem(ImGui.LocalizeGetMsg(ImGuiLocKey.DockingHideTabBar), nil, node:IsHiddenTabBar()) then
            node.WantHiddenTabBarToggle = true
        end
    else
        -- Display a selectable list of windows in this docking node
        for tab_n = 1, tab_bar.Tabs.Size do
            local tab = tab_bar.Tabs.Data[tab_n]
            if bit32.band(tab.Flags, ImGuiTabItemFlags.Button) == 0 then
                if ImGui.Selectable(ImGui.TabBarGetTabName(tab_bar, tab), tab.ID == tab_bar.SelectedTabId) then
                    ImGui.TabBarQueueFocus(tab_bar, tab)
                end
                ImGui.SameLine()
                ImGui.Text("   ")
            end
        end
    end
end

function ImGui.DockNodeWindowMenuUpdate(node, tab_bar)
    -- Try to position the menu so it is more likely to stays within the same viewport
    local g = ImGui.GetCurrentContext()
    if g.Style.WindowMenuButtonPosition == ImGuiDir.Left then
        ImGui.SetNextWindowPos(ImVec2(node.Pos.x, node.Pos.y + ImGui.GetFrameHeight()), ImGuiCond.Always, ImVec2(0.0, 0.0))
    else
        ImGui.SetNextWindowPos(ImVec2(node.Pos.x + node.Size.x, node.Pos.y + ImGui.GetFrameHeight()), ImGuiCond.Always, ImVec2(1.0, 0.0))
    end
    if ImGui.BeginPopup("#WindowMenu") then
        node.IsFocused = true
        g.DockNodeWindowMenuHandler(g, node, tab_bar)
        ImGui.EndPopup()
    end
end

-- User helper to append/amend into a dock node tab bar. Most commonly used to add e.g. a "+" button.
function ImGui.DockNodeBeginAmendTabBar(node)
    if node.TabBar == nil or node.HostWindow == nil then return false end
    if bit32.band(node.MergedFlags, ImGuiDockNodeFlags.KeepAliveOnly) ~= 0 then return false end
    if node.TabBar.ID == 0 then return false end
    ImGui.Begin(node.HostWindow.Name)
    ImGui.PushOverrideID(node.ID)
    local ret = ImGui.BeginTabBarEx(node.TabBar, node.TabBar.BarRect, node.TabBar.Flags)
    IM_ASSERT(ret)
    return true
end

function ImGui.DockNodeEndAmendTabBar()
    ImGui.EndTabBar()
    ImGui.PopID()
    ImGui.End()
end

local function IsDockNodeTitleBarHighlighted(node, root_node)
    -- CTRL+Tab highlight (only highlighting leaf node, not whole hierarchy)
    local g = ImGui.GetCurrentContext()
    if g.NavWindowingTarget then
        return g.NavWindowingTarget.DockNode == node
    end

    -- FIXME-DOCKING: May want alternative to treat central node void differently? e.g. if (g.NavWindow == host_window)
    if g.NavWindow and root_node.LastFocusedNodeId == node.ID then
        -- FIXME: This could all be backed in RootWindowForTitleBarHighlight? Probably need to reorganize for both dock nodes + other RootWindowForTitleBarHighlight users (not-node)
        local parent_window = g.NavWindow.RootWindow
        while bit32.band(parent_window.Flags, ImGuiWindowFlags.ChildMenu) ~= 0 do
            parent_window = parent_window.ParentWindow.RootWindow
        end
        local parent_node = parent_window.DockNodeAsHost or parent_window.DockNode
        while parent_node ~= nil do
            parent_node = ImGui.DockNodeGetRootNode(parent_node)
            if parent_node == root_node then return true end
            parent_node = parent_node.HostWindow and parent_node.HostWindow.RootWindow.DockNode or nil
        end
    end
    return false
end

-- Submit the tab bar corresponding to a dock node and various housekeeping details.
function ImGui.DockNodeUpdateTabBar(node, host_window)
    local g = ImGui.GetCurrentContext()
    local style = g.Style

    local node_was_active = (node.LastFrameActive + 1 == g.FrameCount)
    node.WantCloseAll = false
    node.WantCloseTabId = 0

    -- Decide if we should use a focused title bar color
    local is_focused = false
    local root_node = ImGui.DockNodeGetRootNode(node)
    if IsDockNodeTitleBarHighlighted(node, root_node) then is_focused = true end

    -- Hidden tab bar will show a triangle on the upper-left (in Begin)
    if node:IsHiddenTabBar() or node:IsNoTabBar() then
        node.VisibleWindow = (node.Windows.Size > 0) and node.Windows.Data[1] or nil
        node.IsFocused = is_focused
        if is_focused then node.LastFrameFocused = g.FrameCount end
        if node.VisibleWindow then
            -- Notify root of visible window (used to display title in OS task bar)
            if is_focused or root_node.VisibleWindow == nil then root_node.VisibleWindow = node.VisibleWindow end
            if node.TabBar then node.TabBar.VisibleTabId = node.VisibleWindow.TabId end
        end
        return
    end

    -- Move ourselves to the Menu layer (so we can be accessed by tapping Alt) + undo SkipItems flag in order to draw over the title bar even if the window is collapsed
    local backup_skip_item = host_window.SkipItems
    if not node:IsDockSpace() then
        host_window.SkipItems = false
        host_window.DC.NavLayerCurrent = ImGuiNavLayer.Menu
    end

    -- Use PushOverrideID() instead of PushID() to use the node id _without_ the host window ID.
    -- This is to facilitate computing those ID from the outside, and will affect more or less only the ID of the collapse button, popup and tabs,
    -- as docked windows themselves will override the stack with their own root ID.
    ImGui.PushOverrideID(node.ID)
    local tab_bar = node.TabBar
    local tab_bar_is_recreated = (tab_bar == nil) -- Tab bar are automatically destroyed when a node gets hidden
    if tab_bar == nil then
        ImGui.DockNodeAddTabBar(node)
        tab_bar = node.TabBar
    end

    local focus_tab_id = 0
    node.IsFocused = is_focused

    local node_flags = node.MergedFlags
    local has_window_menu_button = bit32.band(node_flags, ImGuiDockNodeFlags.NoWindowMenuButton) == 0 and (style.WindowMenuButtonPosition ~= ImGuiDir.None)

    -- In a dock node, the Collapse Button turns into the Window Menu button.
    -- FIXME-DOCK FIXME-OPT: Could we recycle popups id across multiple dock nodes?
    if has_window_menu_button and ImGui.IsPopupOpen("#WindowMenu") then
        local next_selected_tab_id = tab_bar.NextSelectedTabId
        ImGui.DockNodeWindowMenuUpdate(node, tab_bar)
        if tab_bar.NextSelectedTabId ~= 0 and tab_bar.NextSelectedTabId ~= next_selected_tab_id then
            focus_tab_id = tab_bar.NextSelectedTabId
        end
        is_focused = is_focused or node.IsFocused
    end

    -- Layout
    local title_bar_rect, tab_bar_rect, window_menu_button_pos, close_button_pos = ImGui.DockNodeCalcTabBarLayout(node)

    -- Submit new tabs, they will be added as Unsorted and sorted below based on relative DockOrder value.
    local tabs_count_old = tab_bar.Tabs.Size
    for window_n = 1, node.Windows.Size do
        local window = node.Windows.Data[window_n]
        if ImGui.TabBarFindTabByID(tab_bar, window.TabId) == nil then
            ImGui.TabBarAddTab(tab_bar, ImGuiTabItemFlags.Unsorted, window)
        end
    end

    -- Title bar
    if is_focused then node.LastFrameFocused = g.FrameCount end
    local title_bar_col = ImGui.GetColorU32(host_window.Collapsed and ImGuiCol.TitleBgCollapsed or (is_focused and ImGuiCol.TitleBgActive or ImGuiCol.TitleBg))
    local rounding_flags = ImGui.CalcRoundingFlagsForRectInRect(title_bar_rect, host_window:Rect(), g.Style.DockingSeparatorSize)
    host_window.DrawList:AddRectFilled(title_bar_rect.Min, title_bar_rect.Max, title_bar_col, host_window.WindowRounding, rounding_flags)

    -- Docking/Collapse button
    if has_window_menu_button then
        if ImGui.CollapseButton(host_window:GetID("#COLLAPSE"), window_menu_button_pos, node) then -- == DockNodeGetWindowMenuButtonId(node)
            ImGui.OpenPopup("#WindowMenu")
        end
        if ImGui.IsItemActive() then focus_tab_id = tab_bar.SelectedTabId end
        if ImGui.IsItemHovered(bit32.bor(ImGuiHoveredFlags.ForTooltip, ImGuiHoveredFlags.DelayNormal)) and g.HoveredIdTimer > 0.5 then
            ImGui.SetTooltip("%s", ImGui.LocalizeGetMsg(ImGuiLocKey.DockingDragToUndockOrMoveNode))
        end
    end

    -- If multiple tabs are appearing on the same frame, sort them based on their persistent DockOrder value
    local tabs_unsorted_start = tab_bar.Tabs.Size -- 0-based
    local tab_n = tab_bar.Tabs.Size - 1
    while tab_n >= 0 and bit32.band(tab_bar.Tabs.Data[tab_n + 1].Flags, ImGuiTabItemFlags.Unsorted) ~= 0 do
        -- FIXME-DOCK: Consider only clearing the flag after the tab has been alive for a few consecutive frames, allowing late comers to not break sorting?
        local t = tab_bar.Tabs.Data[tab_n + 1]
        t.Flags = bit32.band(t.Flags, bit32.bnot(ImGuiTabItemFlags.Unsorted))
        tabs_unsorted_start = tab_n
        tab_n = tab_n - 1
    end
    if tab_bar.Tabs.Size > tabs_unsorted_start + 1 then
        local slice = {}
        for i = tabs_unsorted_start + 1, tab_bar.Tabs.Size do slice[#slice + 1] = tab_bar.Tabs.Data[i] end
        table.sort(slice, TabItemComparerByDockOrder)
        for i, t in ipairs(slice) do tab_bar.Tabs.Data[tabs_unsorted_start + i] = t end
    end

    -- Apply NavWindow focus back to the tab bar
    if g.NavWindow and g.NavWindow.RootWindow.DockNode == node then
        tab_bar.SelectedTabId = g.NavWindow.RootWindow.TabId
    end

    -- Selected newly added tabs, or persistent tab ID if the tab bar was just recreated
    if tab_bar_is_recreated and ImGui.TabBarFindTabByID(tab_bar, node.SelectedTabId) ~= nil then
        tab_bar.SelectedTabId = node.SelectedTabId
        tab_bar.NextSelectedTabId = node.SelectedTabId
    elseif tab_bar.Tabs.Size > tabs_count_old then
        tab_bar.SelectedTabId = tab_bar.Tabs.Data[tab_bar.Tabs.Size].Window.TabId
        tab_bar.NextSelectedTabId = tab_bar.SelectedTabId
    end

    -- Begin tab bar
    local tab_bar_flags = bit32.bor(ImGuiTabBarFlags.Reorderable, ImGuiTabBarFlags.AutoSelectNewTabs) -- | ImGuiTabBarFlags.NoTabListScrollingButtons)
    tab_bar_flags = bit32.bor(tab_bar_flags, ImGuiTabBarFlags.SaveSettings, ImGuiTabBarFlags.DockNode)
    tab_bar_flags = bit32.bor(tab_bar_flags, ImGuiTabBarFlags.FittingPolicyMixed) -- Enforce default policy. Since 1.92.2 this is now reasonable. May expose later if needed. (#8800, #3421)
    tab_bar_flags = bit32.bor(tab_bar_flags, ImGuiTabBarFlags.DrawSelectedOverline)
    if not host_window.Collapsed and is_focused then
        tab_bar_flags = bit32.bor(tab_bar_flags, ImGuiTabBarFlags.IsFocused)
    end
    tab_bar.ID = node.ID -- GetID("#TabBar")
    tab_bar.SeparatorMinX = node.Pos.x + host_window.WindowBorderSize -- Separator cover the whole node width
    tab_bar.SeparatorMaxX = node.Pos.x + node.Size.x - host_window.WindowBorderSize
    ImGui.BeginTabBarEx(tab_bar, tab_bar_rect, tab_bar_flags)
    -- host_window.DrawList:AddRect(tab_bar_rect.Min, tab_bar_rect.Max, IM_COL32(255,0,255,255))

    -- Backup style colors
    local backup_style_cols = {}
    for color_n = 0, ImGuiWindowDockStyleCol.COUNT - 1 do
        local c = g.Style.Colors[GWindowDockStyleColors[color_n]]
        backup_style_cols[color_n] = ImVec4(c.x, c.y, c.z, c.w)
    end

    -- Submit actual tabs
    node.VisibleWindow = nil
    for window_n = 1, node.Windows.Size do
        local window = node.Windows.Data[window_n]
        -- FIXME: Not sure if that's still taken/useful, as windows are normally removed in DockNodeUpdateFlagsAndCollapse().
        if not (window.LastFrameActive + 1 < g.FrameCount and node_was_active) then
            local tab_item_flags = 0
            tab_item_flags = bit32.bor(tab_item_flags, window.WindowClass.TabItemFlagsOverrideSet or 0)
            if bit32.band(window.Flags, ImGuiWindowFlags.UnsavedDocument) ~= 0 then
                tab_item_flags = bit32.bor(tab_item_flags, ImGuiTabItemFlags.UnsavedDocument)
            end
            if bit32.band(tab_bar.Flags, ImGuiTabBarFlags.NoCloseWithMiddleMouseButton) ~= 0 then
                tab_item_flags = bit32.bor(tab_item_flags, ImGuiTabItemFlags.NoCloseWithMiddleMouseButton)
            end

            -- Apply stored style overrides for the window
            for color_n = 0, ImGuiWindowDockStyleCol.COUNT - 1 do
                ImVec4_Copy(g.Style.Colors[GWindowDockStyleColors[color_n]], ImGui.ColorConvertU32ToFloat4(window.DockStyle.Colors[color_n]))
            end

            -- Note that TabItemEx() calls TabBarCalcTabID() so our tab item ID will ignore the current ID stack (rightly so)
            local _, tab_open = ImGui.TabItemEx(tab_bar, window.Name, window.HasCloseButton and true or nil, tab_item_flags, window)
            if tab_open == false then node.WantCloseTabId = window.TabId end
            if tab_bar.VisibleTabId == window.TabId then node.VisibleWindow = window end

            -- Store last item data so it can be queried with IsItemXXX functions after the user Begin() call
            window.DC.DockTabItemStatusFlags = g.LastItemData.StatusFlags
            window.DC.DockTabItemRect = ImRect(g.LastItemData.Rect.Min, g.LastItemData.Rect.Max)

            -- Update navigation ID on menu layer
            if g.NavWindow and g.NavWindow.RootWindow == window and bit32.band(window.DC.NavLayersActiveMask, bit32.lshift(1, ImGuiNavLayer.Menu)) == 0 then
                host_window.NavLastIds[1] = window.TabId
            end
        end
    end

    -- Restore style colors
    for color_n = 0, ImGuiWindowDockStyleCol.COUNT - 1 do
        ImVec4_Copy(g.Style.Colors[GWindowDockStyleColors[color_n]], backup_style_cols[color_n])
    end

    -- Notify root of visible window (used to display title in OS task bar)
    if node.VisibleWindow then
        if is_focused or root_node.VisibleWindow == nil then root_node.VisibleWindow = node.VisibleWindow end
    end

    -- Close button (after VisibleWindow was updated)
    -- Note that VisibleWindow may have been overrided by CTRL+Tabbing, so VisibleWindow.TabId may be ~= from tab_bar.SelectedTabId
    local close_button_is_enabled = node.HasCloseButton and node.VisibleWindow and node.VisibleWindow.HasCloseButton
    local close_button_is_visible = node.HasCloseButton
    -- local close_button_is_visible = close_button_is_enabled -- Most people would expect this behavior of not even showing the button (leaving a hole since we can't claim that space as other windows in the tba bar have one)
    if close_button_is_visible then
        if not close_button_is_enabled then
            ImGui.PushItemFlag(ImGuiItemFlags.Disabled, true)
            local tc = style.Colors[ImGuiCol.Text]
            ImGui.PushStyleColor(ImGuiCol.Text, ImVec4(tc.x, tc.y, tc.z, tc.w * 0.4))
        end
        if ImGui.CloseButton(host_window:GetID("#CLOSE"), close_button_pos) then
            node.WantCloseAll = true
            for n = 1, tab_bar.Tabs.Size do ImGui.TabBarCloseTab(tab_bar, tab_bar.Tabs.Data[n]) end
        end
        -- if IsItemActive() then
        --     focus_tab_id = tab_bar.SelectedTabId
        if not close_button_is_enabled then
            ImGui.PopStyleColor()
            ImGui.PopItemFlag()
        end
    end

    -- When clicking on the title bar outside of tabs, we still focus the selected tab for that node
    -- FIXME: TabItems submitted earlier use AllowItemOverlap so we manually perform a more specific test for now (hovered || held) in order to not cover them.
    local title_bar_id = host_window:GetID("#TITLEBAR")
    if g.HoveredId == 0 or g.HoveredId == title_bar_id or g.ActiveId == title_bar_id then
        -- AllowOverlap mode required for appending into dock node tab bar,
        -- otherwise dragging window will steal HoveredId and amended tabs cannot get them.
        ImGui.KeepAliveID(title_bar_id)
        local _, _, held = ImGui.ButtonBehavior(title_bar_rect, title_bar_id, ImGuiButtonFlags.AllowOverlap)
        if g.HoveredId == title_bar_id then g.LastItemData.ID = title_bar_id end
        if held then
            if ImGui.IsMouseClicked(0) then focus_tab_id = tab_bar.SelectedTabId end

            -- Forward moving request to selected window
            local tab = ImGui.TabBarFindTabByID(tab_bar, tab_bar.SelectedTabId)
            if tab then
                ImGui.StartMouseMovingWindowOrNode(tab.Window or node.HostWindow, node, false) -- Undock from tab bar empty space
            end
        end
    end

    -- Forward focus from host node to selected window
    -- if is_focused and g.NavWindow == host_window and not g.NavWindowingTarget then
    --     focus_tab_id = tab_bar.SelectedTabId

    -- When clicked on a tab we requested focus to the docked child
    -- This overrides the value set by "forward focus from host node to selected window".
    if tab_bar.NextSelectedTabId ~= 0 then focus_tab_id = tab_bar.NextSelectedTabId end

    -- Apply navigation focus
    if focus_tab_id ~= 0 then
        local tab = ImGui.TabBarFindTabByID(tab_bar, focus_tab_id)
        if tab and tab.Window then
            ImGui.FocusWindow(tab.Window)
            if g.NavId == 0 then ImGui.NavInitWindow(tab.Window, false) end -- only init if FocusWindow() didn't restore anything.
        end
    end

    ImGui.EndTabBar()
    ImGui.PopID()

    -- Restore SkipItems flag
    if not node:IsDockSpace() then
        host_window.DC.NavLayerCurrent = ImGuiNavLayer.Main
        host_window.SkipItems = backup_skip_item
    end
end

function ImGui.DockNodeAddTabBar(node)
    IM_ASSERT(node.TabBar == nil)
    node.TabBar = ImGuiTabBar()
end

function ImGui.DockNodeRemoveTabBar(node)
    if node.TabBar == nil then return end
    node.TabBar = nil
end

local function DockNodeIsDropAllowedOne(payload, host_window)
    if host_window.DockNodeAsHost and host_window.DockNodeAsHost:IsDockSpace() and payload.BeginOrderWithinContext < host_window.BeginOrderWithinContext then
        return false
    end

    local host_class = host_window.DockNodeAsHost and host_window.DockNodeAsHost.WindowClass or host_window.WindowClass
    local payload_class = payload.WindowClass
    if host_class.ClassId ~= payload_class.ClassId then
        local pass = false
        if host_class.ClassId ~= 0 and host_class.DockingAllowUnclassed and payload_class.ClassId == 0 then pass = true end
        if payload_class.ClassId ~= 0 and payload_class.DockingAllowUnclassed and host_class.ClassId == 0 then pass = true end
        if not pass then return false end
    end

    -- Prevent docking any window created above a popup
    -- Technically we should support it (e.g. in the case of a long-lived modal window that had fancy docking features),
    -- by e.g. adding a 'if not ImGui.IsWindowWithinBeginStackOf(host_window, popup_window)' test.
    -- But it would requires more work on our end because the dock host windows is technically created in NewFrame()
    -- and our .ParentXXX and .RootXXX pointers inside windows are currently mislading or lacking.
    local g = ImGui.GetCurrentContext()
    for i = g.OpenPopupStack.Size, 1, -1 do
        local popup_window = g.OpenPopupStack.Data[i].Window
        if popup_window and ImGui.IsWindowWithinBeginStackOf(payload, popup_window) then -- Payload is created from within a popup begin stack.
            return false
        end
    end
    return true
end

function ImGui.DockNodeIsDropAllowed(host_window, root_payload)
    if root_payload.DockNodeAsHost and root_payload.DockNodeAsHost:IsSplitNode() then return true end -- FIXME-DOCK: Missing filtering
    local payload_count = root_payload.DockNodeAsHost and root_payload.DockNodeAsHost.Windows.Size or 1
    for payload_n = 1, payload_count do
        local payload = root_payload.DockNodeAsHost and root_payload.DockNodeAsHost.Windows.Data[payload_n] or root_payload
        if DockNodeIsDropAllowedOne(payload, host_window) then return true end
    end
    return false
end

-- window menu button == collapse button when not in a dock node.
-- FIXME: This is similar to RenderWindowTitleBarContents(), may want to share code.
--- @return ImRect title_rect, ImRect tab_bar_rect, ImVec2 window_menu_button_pos, ImVec2? close_button_pos
function ImGui.DockNodeCalcTabBarLayout(node)
    local g = ImGui.GetCurrentContext()
    local style = g.Style

    local r = ImRect(node.Pos.x, node.Pos.y, node.Pos.x + node.Size.x, node.Pos.y + g.FontSize + g.Style.FramePadding.y * 2.0)
    local out_title_rect = ImRect(r.Min, r.Max)

    r.Min.x = r.Min.x + style.WindowBorderSize
    r.Max.x = r.Max.x - style.WindowBorderSize

    local button_sz = g.FontSize
    r.Min.x = r.Min.x + style.FramePadding.x
    r.Max.x = r.Max.x - style.FramePadding.x
    local window_menu_button_pos = ImVec2(r.Min.x, r.Min.y + style.FramePadding.y)
    local out_close_button_pos = nil
    if node.HasCloseButton then
        out_close_button_pos = ImVec2(r.Max.x - button_sz, r.Min.y + style.FramePadding.y)
        r.Max.x = r.Max.x - (button_sz + style.ItemInnerSpacing.x)
    end
    if node.HasWindowMenuButton and style.WindowMenuButtonPosition == ImGuiDir.Left then
        r.Min.x = r.Min.x + button_sz + style.ItemInnerSpacing.x
    elseif node.HasWindowMenuButton and style.WindowMenuButtonPosition == ImGuiDir.Right then
        window_menu_button_pos = ImVec2(r.Max.x - button_sz, r.Min.y + style.FramePadding.y)
        r.Max.x = r.Max.x - (button_sz + style.ItemInnerSpacing.x)
    end
    return out_title_rect, r, window_menu_button_pos, out_close_button_pos
end

--- Modifies pos_old/size_old/pos_new/size_new in place (ImVec2 tables)
function ImGui.DockNodeCalcSplitRects(pos_old, size_old, pos_new, size_new, dir, size_new_desired)
    local g = ImGui.GetCurrentContext()
    local dock_spacing = g.Style.ItemInnerSpacing.x
    local axis = (dir == ImGuiDir.Left or dir == ImGuiDir.Right) and ImGuiAxis.X or ImGuiAxis.Y
    local a, o = axis, 3 - axis -- the port's ImGuiAxis is 1-based (X=1,Y=2): it is directly the ImVec2 index
    pos_new[o] = pos_old[o]
    size_new[o] = size_old[o]

    -- Distribute size on given axis (with a desired size or equally)
    local w_avail = size_old[a] - dock_spacing
    if size_new_desired[a] > 0.0 and size_new_desired[a] <= w_avail * 0.5 then
        size_new[a] = size_new_desired[a]
        size_old[a] = IM_TRUNC(w_avail - size_new[a])
    else
        size_new[a] = IM_TRUNC(w_avail * 0.5)
        size_old[a] = IM_TRUNC(w_avail - size_new[a])
    end

    -- Position each node
    if dir == ImGuiDir.Right or dir == ImGuiDir.Down then
        pos_new[a] = pos_old[a] + size_old[a] + dock_spacing
    elseif dir == ImGuiDir.Left or dir == ImGuiDir.Up then
        pos_new[a] = pos_old[a]
        pos_old[a] = pos_new[a] + size_new[a] + dock_spacing
    end
end

local function ImGetDirQuadrantFromDeltaLocal(dx, dy)
    if math.abs(dx) > math.abs(dy) then
        return (dx > 0.0) and ImGuiDir.Right or ImGuiDir.Left
    end
    return (dy > 0.0) and ImGuiDir.Down or ImGuiDir.Up
end

-- Retrieve the drop rectangles for a given direction or for the center + perform hit testing.
--- @return bool hit, ImRect out_r
function ImGui.DockNodeCalcDropRectsAndTestMousePos(parent, dir, outer_docking, test_mouse_pos)
    local g = ImGui.GetCurrentContext()

    local parent_smaller_axis = ImMin(parent:GetWidth(), parent:GetHeight())
    local hs_for_central_nodes = ImMin(g.FontSize * 1.5, ImMax(g.FontSize * 0.5, parent_smaller_axis / 8.0))
    local hs_w, hs_h, off -- Half-size, longer axis / Half-size, smaller axis / Distance from edge or center
    if outer_docking then
        -- hs_w = ImTrunc(ImClamp(parent_smaller_axis - hs_for_central_nodes * 4.0, g.FontSize * 0.5, g.FontSize * 8.0))
        -- hs_h = ImTrunc(hs_w * 0.15)
        -- off = ImVec2(ImTrunc(parent:GetWidth() * 0.5 - GetFrameHeightWithSpacing() * 1.4 - hs_h), ImTrunc(parent:GetHeight() * 0.5 - GetFrameHeightWithSpacing() * 1.4 - hs_h))
        hs_w = ImTrunc(hs_for_central_nodes * 1.50)
        hs_h = ImTrunc(hs_for_central_nodes * 0.80)
        off = ImVec2(ImTrunc(parent:GetWidth() * 0.5 - hs_h), ImTrunc(parent:GetHeight() * 0.5 - hs_h))
    else
        hs_w = ImTrunc(hs_for_central_nodes)
        hs_h = ImTrunc(hs_for_central_nodes * 0.90)
        off = ImVec2(ImTrunc(hs_w * 2.40), ImTrunc(hs_w * 2.40))
    end

    local pc = parent:GetCenter()
    local c = ImVec2(ImTrunc(pc.x), ImTrunc(pc.y))
    local out_r
    if dir == ImGuiDir.None then out_r = ImRect(c.x - hs_w, c.y - hs_w, c.x + hs_w, c.y + hs_w)
    elseif dir == ImGuiDir.Up then out_r = ImRect(c.x - hs_w, c.y - off.y - hs_h, c.x + hs_w, c.y - off.y + hs_h)
    elseif dir == ImGuiDir.Down then out_r = ImRect(c.x - hs_w, c.y + off.y - hs_h, c.x + hs_w, c.y + off.y + hs_h)
    elseif dir == ImGuiDir.Left then out_r = ImRect(c.x - off.x - hs_h, c.y - hs_w, c.x - off.x + hs_h, c.y + hs_w)
    elseif dir == ImGuiDir.Right then out_r = ImRect(c.x + off.x - hs_h, c.y - hs_w, c.x + off.x + hs_h, c.y + hs_w) end

    if test_mouse_pos == nil then return false, out_r end

    local hit_r = ImRect(out_r.Min, out_r.Max)
    if not outer_docking then
        -- Custom hit testing for the 5-way selection, designed to reduce flickering when moving diagonally between sides
        hit_r:Expand(ImTrunc(hs_w * 0.30))
        local mdx, mdy = test_mouse_pos.x - c.x, test_mouse_pos.y - c.y
        local mouse_delta_len2 = mdx * mdx + mdy * mdy
        local r_threshold_center = hs_w * 1.4
        local r_threshold_sides = hs_w * (1.4 + 1.2)
        if mouse_delta_len2 < r_threshold_center * r_threshold_center then
            return (dir == ImGuiDir.None), out_r
        end
        if mouse_delta_len2 < r_threshold_sides * r_threshold_sides then
            return (dir == ImGetDirQuadrantFromDeltaLocal(mdx, mdy)), out_r
        end
    end
    return hit_r:Contains(test_mouse_pos), out_r
end

-- host_node may be nil if the window doesn't have a DockNode already.
-- FIXME-DOCK: This is misnamed since it's also doing the filtering.
function ImGui.DockNodePreviewDockSetup(host_window, host_node, payload_window, payload_node, data, is_explicit_target, is_outer_docking)
    local g = ImGui.GetCurrentContext()

    -- There is an edge case when docking into a dockspace which only has inactive nodes.
    -- In this case DockNodeTreeFindNodeByPos() will have selected a leaf node which is inactive.
    -- Because the inactive leaf node doesn't have proper pos/size yet, we'll use the root node as reference.
    if payload_node == nil then payload_node = payload_window.DockNodeAsHost end
    local ref_node_for_rect = (host_node and not host_node.IsVisible) and ImGui.DockNodeGetRootNode(host_node) or host_node
    if ref_node_for_rect then IM_ASSERT(ref_node_for_rect.IsVisible == true) end

    -- Filter, figure out where we are allowed to dock
    local src_node_flags = payload_node and payload_node.MergedFlags or payload_window.WindowClass.DockNodeFlagsOverrideSet
    local dst_node_flags = host_node and host_node.MergedFlags or host_window.WindowClass.DockNodeFlagsOverrideSet
    data.IsCenterAvailable = true
    if is_outer_docking then
        data.IsCenterAvailable = false
    elseif g.IO.ConfigDockingNoDockingOver then
        data.IsCenterAvailable = false
    elseif bit32.band(dst_node_flags, ImGuiDockNodeFlags.NoDockingOverMe) ~= 0 then
        data.IsCenterAvailable = false
    elseif host_node and bit32.band(dst_node_flags, ImGuiDockNodeFlags.NoDockingOverCentralNode) ~= 0 and host_node:IsCentralNode() then
        data.IsCenterAvailable = false
    elseif (not host_node or not host_node:IsEmpty()) and payload_node and payload_node:IsSplitNode() and (payload_node.OnlyNodeWithWindows == nil) then -- Is _visibly_ split?
        data.IsCenterAvailable = false
    elseif bit32.band(src_node_flags, ImGuiDockNodeFlags.NoDockingOverOther) ~= 0 and (not host_node or not host_node:IsEmpty()) then
        data.IsCenterAvailable = false
    elseif bit32.band(src_node_flags, ImGuiDockNodeFlags.NoDockingOverEmpty) ~= 0 and host_node and host_node:IsEmpty() then
        data.IsCenterAvailable = false
    end

    data.IsSidesAvailable = true
    if bit32.band(dst_node_flags, ImGuiDockNodeFlags.NoDockingSplit) ~= 0 or g.IO.ConfigDockingNoSplit then
        data.IsSidesAvailable = false
    elseif not is_outer_docking and host_node and host_node.ParentNode == nil and host_node:IsCentralNode() then
        data.IsSidesAvailable = false
    elseif bit32.band(src_node_flags, ImGuiDockNodeFlags.NoDockingSplitOther) ~= 0 then
        data.IsSidesAvailable = false
    end

    -- Build a tentative future node (reuse same structure because it is practical. Shape will be readjusted when previewing a split)
    data.FutureNode.HasCloseButton = (host_node and host_node.HasCloseButton or (not host_node and host_window.HasCloseButton)) or payload_window.HasCloseButton
    data.FutureNode.HasWindowMenuButton = host_node and true or (bit32.band(host_window.Flags, ImGuiWindowFlags.NoCollapse) == 0)
    local rp = ref_node_for_rect and ref_node_for_rect.Pos or host_window.Pos
    local rs = ref_node_for_rect and ref_node_for_rect.Size or host_window.Size
    data.FutureNode.Pos = ImVec2(rp.x, rp.y)
    data.FutureNode.Size = ImVec2(rs.x, rs.y)

    -- Calculate drop shapes geometry for allowed splitting directions
    data.SplitNode = host_node
    data.SplitDir = ImGuiDir.None
    data.IsSplitDirExplicit = false
    if not host_window.Collapsed then
        for dir = ImGuiDir.None, ImGuiDir.COUNT - 1 do
            if not ((dir == ImGuiDir.None and not data.IsCenterAvailable) or (dir ~= ImGuiDir.None and not data.IsSidesAvailable)) then
                local hit, r = ImGui.DockNodeCalcDropRectsAndTestMousePos(data.FutureNode:Rect(), dir, is_outer_docking, g.IO.MousePos)
                data.DropRectsDraw[dir + 1] = r
                if hit then
                    data.SplitDir = dir
                    data.IsSplitDirExplicit = true
                end
            end
        end
    end

    -- When docking without holding Shift, we only allow and preview docking when hovering over a drop rect or over the title bar
    data.IsDropAllowed = (data.SplitDir ~= ImGuiDir.None) or data.IsCenterAvailable
    if not is_explicit_target and not data.IsSplitDirExplicit and not g.IO.ConfigDockingWithShift then
        data.IsDropAllowed = false
    end

    -- Calculate split area
    data.SplitRatio = 0.0
    if data.SplitDir ~= ImGuiDir.None then
        local split_dir = data.SplitDir
        local split_axis = (split_dir == ImGuiDir.Left or split_dir == ImGuiDir.Right) and ImGuiAxis.X or ImGuiAxis.Y
        local pos_new, pos_old = ImVec2(0, 0), ImVec2(data.FutureNode.Pos.x, data.FutureNode.Pos.y)
        local size_new, size_old = ImVec2(0, 0), ImVec2(data.FutureNode.Size.x, data.FutureNode.Size.y)
        ImGui.DockNodeCalcSplitRects(pos_old, size_old, pos_new, size_new, split_dir, payload_window.Size)

        -- Calculate split ratio so we can pass it down the docking request
        local split_ratio = ImSaturate(size_new[split_axis] / data.FutureNode.Size[split_axis])
        data.FutureNode.Pos = pos_new
        data.FutureNode.Size = size_new
        data.SplitRatio = (split_dir == ImGuiDir.Right or split_dir == ImGuiDir.Down) and (1.0 - split_ratio) or split_ratio
    end
end

function ImGui.DockNodePreviewDockRender(host_window, host_node, root_payload, data)
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(g.CurrentWindow == host_window)   -- Because we rely on font size to calculate tab sizes

    -- With this option, we only display the preview on the target viewport, and the payload viewport is made transparent.
    -- To compensate for the single layer obstructed by the payload, we'll increase the alpha of the preview nodes.
    local is_transparent_payload = g.IO.ConfigDockingTransparentPayload

    local overlay_draw_lists = { ImGui.GetForegroundDrawList(host_window.Viewport) }

    -- Draw main preview rectangle
    local overlay_col_main = ImGui.GetColorU32(ImGuiCol.DockingPreview, is_transparent_payload and 0.60 or 0.40)
    local overlay_col_drop = ImGui.GetColorU32(ImGuiCol.DockingPreview, is_transparent_payload and 0.90 or 0.70)
    local overlay_col_drop_hovered = ImGui.GetColorU32(ImGuiCol.DockingPreview, is_transparent_payload and 1.20 or 1.00)
    local overlay_col_lines = ImGui.GetColorU32(ImGuiCol.NavWindowingHighlight, is_transparent_payload and 0.80 or 0.60)

    -- Display area preview
    local can_preview_tabs = (root_payload.DockNodeAsHost == nil or root_payload.DockNodeAsHost.Windows.Size > 0)
    if data.IsDropAllowed then
        local overlay_rect = data.FutureNode:Rect()
        if data.SplitDir == ImGuiDir.None and can_preview_tabs then
            overlay_rect.Min.y = overlay_rect.Min.y + ImGui.GetFrameHeight()
        end
        if data.SplitDir ~= ImGuiDir.None or data.IsCenterAvailable then
            for _, dl in ipairs(overlay_draw_lists) do
                dl:AddRectFilled(overlay_rect.Min, overlay_rect.Max, overlay_col_main, host_window.WindowRounding, ImGui.CalcRoundingFlagsForRectInRect(overlay_rect, host_window:Rect(), g.Style.DockingSeparatorSize))
            end
        end
    end

    -- Display tab shape/label preview unless we are splitting node (it generally makes the situation harder to read)
    if data.IsDropAllowed and can_preview_tabs and data.SplitDir == ImGuiDir.None and data.IsCenterAvailable then
        -- Compute target tab bar geometry so we can locate our preview tabs
        local _, tab_bar_rect = ImGui.DockNodeCalcTabBarLayout(data.FutureNode)
        local tab_pos = ImVec2(tab_bar_rect.Min.x, tab_bar_rect.Min.y)
        if host_node and host_node.TabBar then
            if not host_node:IsHiddenTabBar() and not host_node:IsNoTabBar() then
                tab_pos.x = tab_pos.x + host_node.TabBar.WidthAllTabs + g.Style.ItemInnerSpacing.x -- We don't use OffsetNewTab because when using non-persistent-order tab bar it is incremented with each Tab submission.
            else
                tab_pos.x = tab_pos.x + g.Style.ItemInnerSpacing.x + ImGui.TabItemCalcSize(host_node.Windows.Data[1]).x
            end
        elseif bit32.band(host_window.Flags, ImGuiWindowFlags.DockNodeHost) == 0 then
            tab_pos.x = tab_pos.x + g.Style.ItemInnerSpacing.x + ImGui.TabItemCalcSize(host_window).x -- Account for slight offset which will be added when changing from title bar to tab bar
        end

        -- Draw tab shape/label preview (payload may be a loose window or a host window carrying multiple tabbed windows)
        if root_payload.DockNodeAsHost then
            IM_ASSERT(root_payload.DockNodeAsHost.Windows.Size <= root_payload.DockNodeAsHost.TabBar.Tabs.Size)
        end
        local tab_bar_with_payload = root_payload.DockNodeAsHost and root_payload.DockNodeAsHost.TabBar or nil
        local payload_count = tab_bar_with_payload and tab_bar_with_payload.Tabs.Size or 1
        for payload_n = 1, payload_count do
            -- DockNode's TabBar may have non-window Tabs manually appended by user
            local payload_window = tab_bar_with_payload and tab_bar_with_payload.Tabs.Data[payload_n].Window or root_payload
            if not (tab_bar_with_payload and payload_window == nil) and DockNodeIsDropAllowedOne(payload_window, host_window) then
                -- Calculate the tab bounding box for each payload window
                local tab_size = ImGui.TabItemCalcSize(payload_window)
                local tab_bb = ImRect(tab_pos.x, tab_pos.y, tab_pos.x + tab_size.x, tab_pos.y + tab_size.y)
                tab_pos.x = tab_pos.x + tab_size.x + g.Style.ItemInnerSpacing.x
                local overlay_col_text = ImGui.GetColorU32(payload_window.DockStyle.Colors[ImGuiWindowDockStyleCol.Text], 1.0, true)
                local overlay_col_tabs = ImGui.GetColorU32(payload_window.DockStyle.Colors[ImGuiWindowDockStyleCol.TabSelected], 1.0, true)
                local overlay_col_unsaved_marker = ImGui.GetColorU32(payload_window.DockStyle.Colors[ImGuiWindowDockStyleCol.UnsavedMarker], 1.0, true)
                ImGui.PushStyleColor(ImGuiCol.Text, ImGui.ColorConvertU32ToFloat4(overlay_col_text))
                ImGui.PushStyleColor(ImGuiCol.UnsavedMarker, ImGui.ColorConvertU32ToFloat4(overlay_col_unsaved_marker))
                for _, dl in ipairs(overlay_draw_lists) do
                    local tab_flags = bit32.band(payload_window.Flags, ImGuiWindowFlags.UnsavedDocument) ~= 0 and ImGuiTabItemFlags.UnsavedDocument or 0
                    local contains = tab_bar_rect:Contains(tab_bb)
                    if not contains then dl:PushClipRect(tab_bar_rect.Min, tab_bar_rect.Max) end
                    ImGui.TabItemBackground(dl, tab_bb, tab_flags, overlay_col_tabs)
                    ImGui.TabItemLabelAndCloseButton(dl, tab_bb, tab_flags, g.Style.FramePadding, payload_window.Name, 0, 0, false)
                    if not contains then dl:PopClipRect() end
                end
                ImGui.PopStyleColor(2)
            end
        end
    end

    -- Display drop boxes
    local scale = g.Style._MainScale or 1.0 -- FIXME-DPI
    local overlay_rounding = ImMax(math.floor(3.0 * scale), g.Style.FrameRounding)
    for dir = ImGuiDir.None, ImGuiDir.COUNT - 1 do
        local draw_r = data.DropRectsDraw[dir + 1]
        if not IsRectInverted(draw_r) then
            local draw_r_in = ImRect(draw_r.Min, draw_r.Max)
            draw_r_in:Expand(math.floor(-2.0 * scale))
            local overlay_col = (data.SplitDir == dir and data.IsSplitDirExplicit) and overlay_col_drop_hovered or overlay_col_drop
            local thickness = math.floor(1.0 * scale)
            for _, dl in ipairs(overlay_draw_lists) do
                local cc = draw_r_in:GetCenter()
                local center = ImVec2(math.floor(cc.x), math.floor(cc.y))
                dl:AddRectFilled(draw_r.Min, draw_r.Max, overlay_col, overlay_rounding)
                dl:AddRect(draw_r_in.Min, draw_r_in.Max, overlay_col_lines, overlay_rounding, thickness)
                if dir == ImGuiDir.Left or dir == ImGuiDir.Right then
                    dl:AddLineV(center.x, draw_r_in.Min.y, draw_r_in.Max.y, overlay_col_lines, thickness)
                end
                if dir == ImGuiDir.Up or dir == ImGuiDir.Down then
                    dl:AddLineH(draw_r_in.Min.x, draw_r_in.Max.x, center.y, overlay_col_lines, thickness)
                end
            end
        end

        -- Stop after ImGuiDir.None
        if (host_node and bit32.band(host_node.MergedFlags, ImGuiDockNodeFlags.NoDockingSplit) ~= 0) or g.IO.ConfigDockingNoSplit then
            return
        end
    end
end

-------------------------------------------------------------------------------
-- Docking: ImGuiDockNode Tree manipulation functions
-------------------------------------------------------------------------------
-- - DockNodeTreeSplit()
-- - DockNodeTreeMerge()
-- - DockNodeTreeUpdatePosSize()
-- - DockNodeTreeUpdateSplitterFindTouchingNode()
-- - DockNodeTreeUpdateSplitter()
-- - DockNodeTreeFindFallbackLeafNode()
-- - DockNodeTreeFindNodeByPos()
-------------------------------------------------------------------------------

function ImGui.DockNodeTreeSplit(ctx, parent_node, split_axis, split_inheritor_child_idx, split_ratio, new_node)
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(split_axis ~= ImGuiAxis.None)

    local child_0 = (new_node and split_inheritor_child_idx ~= 0) and new_node or ImGui.DockContextAddNode(ctx, 0)
    child_0.ParentNode = parent_node

    local child_1 = (new_node and split_inheritor_child_idx ~= 1) and new_node or ImGui.DockContextAddNode(ctx, 0)
    child_1.ParentNode = parent_node

    local child_inheritor = (split_inheritor_child_idx == 0) and child_0 or child_1
    ImGui.DockNodeMoveChildNodes(child_inheritor, parent_node)
    parent_node.ChildNodes[0] = child_0
    parent_node.ChildNodes[1] = child_1
    parent_node.ChildNodes[split_inheritor_child_idx].VisibleWindow = parent_node.VisibleWindow
    parent_node.SplitAxis = split_axis
    parent_node.VisibleWindow = nil
    parent_node.AuthorityForPos = ImGuiDataAuthority.DockNode
    parent_node.AuthorityForSize = ImGuiDataAuthority.DockNode

    local a = split_axis
    local size_avail = parent_node.Size[a] - g.Style.DockingSeparatorSize
    size_avail = ImMax(size_avail, g.Style.WindowMinSize[a] * 2.0)
    IM_ASSERT(size_avail > 0.0) -- If you created a node manually with DockBuilderAddNode(), you need to also call DockBuilderSetNodeSize() before splitting.
    child_0.SizeRef = ImVec2(parent_node.Size.x, parent_node.Size.y)
    child_1.SizeRef = ImVec2(parent_node.Size.x, parent_node.Size.y)
    child_0.SizeRef[a] = ImTrunc(size_avail * split_ratio)
    child_1.SizeRef[a] = ImTrunc(size_avail - child_0.SizeRef[a])

    ImGui.DockNodeMoveWindows(parent_node.ChildNodes[split_inheritor_child_idx], parent_node)
    DockSettingsRenameNodeReferences(parent_node.ID, parent_node.ChildNodes[split_inheritor_child_idx].ID)
    ImGui.DockNodeUpdateHasCentralNodeChild(ImGui.DockNodeGetRootNode(parent_node))
    ImGui.DockNodeTreeUpdatePosSize(parent_node, parent_node.Pos, parent_node.Size)

    -- Flags transfer (e.g. this is where we transfer the ImGuiDockNodeFlags.CentralNode property)
    child_0.SharedFlags = bit32.band(parent_node.SharedFlags, ImGuiDockNodeFlags.SharedFlagsInheritMask_)
    child_1.SharedFlags = bit32.band(parent_node.SharedFlags, ImGuiDockNodeFlags.SharedFlagsInheritMask_)
    child_inheritor.LocalFlags = bit32.band(parent_node.LocalFlags, ImGuiDockNodeFlags.LocalFlagsTransferMask_)
    parent_node.LocalFlags = bit32.band(parent_node.LocalFlags, bit32.bnot(ImGuiDockNodeFlags.LocalFlagsTransferMask_))
    child_0:UpdateMergedFlags()
    child_1:UpdateMergedFlags()
    parent_node:UpdateMergedFlags()
    if child_inheritor:IsCentralNode() then
        ImGui.DockNodeGetRootNode(parent_node).CentralNode = child_inheritor
    end
end

function ImGui.DockNodeTreeMerge(ctx, parent_node, merge_lead_child)
    -- When called from DockContextProcessUndockNode() it is possible that one of the child is nil.
    local child_0 = parent_node.ChildNodes[0]
    local child_1 = parent_node.ChildNodes[1]
    IM_ASSERT(child_0 or child_1)
    IM_ASSERT(merge_lead_child == child_0 or merge_lead_child == child_1)
    if (child_0 and child_0.Windows.Size > 0) or (child_1 and child_1.Windows.Size > 0) then
        IM_ASSERT(parent_node.TabBar == nil)
        IM_ASSERT(parent_node.Windows.Size == 0)
    end

    local backup_last_explicit_size = ImVec2(parent_node.SizeRef.x, parent_node.SizeRef.y)
    ImGui.DockNodeMoveChildNodes(parent_node, merge_lead_child)
    if child_0 then
        ImGui.DockNodeMoveWindows(parent_node, child_0) -- Generally only 1 of the 2 child node will have windows
        DockSettingsRenameNodeReferences(child_0.ID, parent_node.ID)
    end
    if child_1 then
        ImGui.DockNodeMoveWindows(parent_node, child_1)
        DockSettingsRenameNodeReferences(child_1.ID, parent_node.ID)
    end
    ImGui.DockNodeApplyPosSizeToWindows(parent_node)
    parent_node.AuthorityForPos = ImGuiDataAuthority.Auto
    parent_node.AuthorityForSize = ImGuiDataAuthority.Auto
    parent_node.AuthorityForViewport = ImGuiDataAuthority.Auto
    parent_node.VisibleWindow = merge_lead_child.VisibleWindow
    parent_node.SizeRef = backup_last_explicit_size

    -- Flags transfer
    local M = ImGuiDockNodeFlags.LocalFlagsTransferMask_
    parent_node.LocalFlags = bit32.band(parent_node.LocalFlags, bit32.bnot(M)) -- Preserve Dockspace flag
    parent_node.LocalFlags = bit32.bor(parent_node.LocalFlags, bit32.band(child_0 and child_0.LocalFlags or 0, M))
    parent_node.LocalFlags = bit32.bor(parent_node.LocalFlags, bit32.band(child_1 and child_1.LocalFlags or 0, M))
    parent_node.LocalFlagsInWindows = bit32.bor(child_0 and child_0.LocalFlagsInWindows or 0, child_1 and child_1.LocalFlagsInWindows or 0) -- FIXME: Would be more consistent to update from actual windows
    parent_node:UpdateMergedFlags()

    if child_0 then ImGui.DockContextDeleteNode(ctx, child_0) end
    if child_1 then ImGui.DockContextDeleteNode(ctx, child_1) end
end

-- Update Pos/Size for a node hierarchy (don't affect child Windows yet)
-- (Depth-first, Pre-Order)
function ImGui.DockNodeTreeUpdatePosSize(node, pos, size, only_write_to_single_node)
    -- During the regular dock node update we write to all nodes.
    -- 'only_write_to_single_node' is only set when turning a node visible mid-frame and we need its size right-away.
    local g = ImGui.GetCurrentContext()
    local write_to_node = only_write_to_single_node == nil or only_write_to_single_node == node
    if write_to_node then
        node.Pos = ImVec2(pos.x, pos.y)
        node.Size = ImVec2(size.x, size.y)
    end

    if node:IsLeafNode() then return end

    local child_0 = node.ChildNodes[0]
    local child_1 = node.ChildNodes[1]
    local child_0_pos, child_1_pos = ImVec2(pos.x, pos.y), ImVec2(pos.x, pos.y)
    local child_0_size, child_1_size = ImVec2(size.x, size.y), ImVec2(size.x, size.y)

    local child_0_is_toward_single_node = (only_write_to_single_node ~= nil and ImGui.DockNodeIsInHierarchyOf(only_write_to_single_node, child_0))
    local child_1_is_toward_single_node = (only_write_to_single_node ~= nil and ImGui.DockNodeIsInHierarchyOf(only_write_to_single_node, child_1))
    local child_0_is_or_will_be_visible = child_0.IsVisible or child_0_is_toward_single_node
    local child_1_is_or_will_be_visible = child_1.IsVisible or child_1_is_toward_single_node

    if child_0_is_or_will_be_visible and child_1_is_or_will_be_visible then
        local spacing = g.Style.DockingSeparatorSize
        local a = node.SplitAxis
        local size_avail = ImMax(size[a] - spacing, 0.0)

        -- Size allocation policy
        -- 1) The first 0..WindowMinSize[axis]*2 are allocated evenly to both windows.
        local size_min_each = ImTrunc(ImMin(size_avail, g.Style.WindowMinSize[a] * 2.0) * 0.5)

        -- FIXME: Blocks 2) and 3) are essentially doing nearly the same thing.
        -- Difference are: write-back to SizeRef; application of a minimum size; rounding before ImTrunc()
        -- Clarify and rework differences between Size & SizeRef and purpose of WantLockSizeOnce

        -- 2) Process locked absolute size (during a splitter resize we preserve the child of nodes not touching the splitter edge)
        if child_0.WantLockSizeOnce and not child_1.WantLockSizeOnce then
            child_0_size[a] = ImMin(size_avail - 1.0, child_0.Size[a]); child_0.SizeRef[a] = child_0_size[a]
            child_1_size[a] = size_avail - child_0_size[a]; child_1.SizeRef[a] = child_1_size[a]
        elseif child_1.WantLockSizeOnce and not child_0.WantLockSizeOnce then
            child_1_size[a] = ImMin(size_avail - 1.0, child_1.Size[a]); child_1.SizeRef[a] = child_1_size[a]
            child_0_size[a] = size_avail - child_1_size[a]; child_0.SizeRef[a] = child_0_size[a]
        elseif child_0.WantLockSizeOnce and child_1.WantLockSizeOnce then
            -- FIXME-DOCK: We cannot honor the requested size, so apply ratio.
            -- Currently this path will only be taken if code programmatically sets WantLockSizeOnce
            local split_ratio = child_0_size[a] / (child_0_size[a] + child_1_size[a])
            child_0_size[a] = ImTrunc(size_avail * split_ratio); child_0.SizeRef[a] = child_0_size[a]
            child_1_size[a] = size_avail - child_0_size[a]; child_1.SizeRef[a] = child_1_size[a]

        -- 3) If one window is the central node (~ use remaining space, should be made explicit!), use explicit size from the other, and remainder for the central node
        elseif child_0.SizeRef[a] ~= 0.0 and child_1.HasCentralNodeChild then
            child_0_size[a] = ImMin(size_avail - size_min_each, child_0.SizeRef[a])
            child_1_size[a] = size_avail - child_0_size[a]
        elseif child_1.SizeRef[a] ~= 0.0 and child_0.HasCentralNodeChild then
            child_1_size[a] = ImMin(size_avail - size_min_each, child_1.SizeRef[a])
            child_0_size[a] = size_avail - child_1_size[a]
        else
            -- 4) Otherwise distribute according to the relative ratio of each SizeRef value
            local split_ratio = child_0.SizeRef[a] / (child_0.SizeRef[a] + child_1.SizeRef[a])
            child_0_size[a] = ImMax(size_min_each, ImTrunc(size_avail * split_ratio + 0.5))
            child_1_size[a] = size_avail - child_0_size[a]
        end

        child_1_pos[a] = child_1_pos[a] + spacing + child_0_size[a]
    end

    if only_write_to_single_node == nil then
        child_0.WantLockSizeOnce = false
        child_1.WantLockSizeOnce = false
    end
    local child_0_recurse = only_write_to_single_node and child_0_is_toward_single_node or (not only_write_to_single_node and child_0.IsVisible)
    local child_1_recurse = only_write_to_single_node and child_1_is_toward_single_node or (not only_write_to_single_node and child_1.IsVisible)
    if child_0_recurse then ImGui.DockNodeTreeUpdatePosSize(child_0, child_0_pos, child_0_size) end
    if child_1_recurse then ImGui.DockNodeTreeUpdatePosSize(child_1, child_1_pos, child_1_size) end
end

local function DockNodeTreeUpdateSplitterFindTouchingNode(node, axis, side, touching_nodes)
    if node:IsLeafNode() then
        table.insert(touching_nodes, node)
        return
    end
    if node.ChildNodes[0].IsVisible then
        if node.SplitAxis ~= axis or side == 0 or not node.ChildNodes[1].IsVisible then
            DockNodeTreeUpdateSplitterFindTouchingNode(node.ChildNodes[0], axis, side, touching_nodes)
        end
    end
    if node.ChildNodes[1].IsVisible then
        if node.SplitAxis ~= axis or side == 1 or not node.ChildNodes[0].IsVisible then
            DockNodeTreeUpdateSplitterFindTouchingNode(node.ChildNodes[1], axis, side, touching_nodes)
        end
    end
end

local WINDOWS_RESIZE_FROM_EDGES_FEEDBACK_TIMER = 0.04 -- Reduce visual noise by only highlighting the border after a certain time.

-- (Depth-First, Pre-Order)
function ImGui.DockNodeTreeUpdateSplitter(node)
    if node:IsLeafNode() then return end

    local g = ImGui.GetCurrentContext()

    local child_0 = node.ChildNodes[0]
    local child_1 = node.ChildNodes[1]
    if child_0.IsVisible and child_1.IsVisible then
        -- Bounding box of the splitter cover the space between both nodes (w = Spacing, h = Size[xy^1] for when splitting horizontally)
        local axis = node.SplitAxis
        IM_ASSERT(axis ~= ImGuiAxis.None)
        local a, o = axis, 3 - axis -- the port's ImGuiAxis is 1-based (X=1,Y=2): it is directly the ImVec2 index
        local bb = ImRect(ImVec2(child_0.Pos.x, child_0.Pos.y), ImVec2(child_1.Pos.x, child_1.Pos.y))
        bb.Min[a] = bb.Min[a] + child_0.Size[a]
        bb.Max[o] = bb.Max[o] + child_1.Size[o]
        -- if g.IO.KeyCtrl then GetForegroundDrawList(g.CurrentWindow.Viewport):AddRect(bb.Min, bb.Max, IM_COL32(255,0,255,255)) end

        local merged_flags = bit32.bor(child_0.MergedFlags, child_1.MergedFlags) -- Merged flags for BOTH childs
        local no_resize_axis_flag = (axis == ImGuiAxis.X) and ImGuiDockNodeFlags.NoResizeX or ImGuiDockNodeFlags.NoResizeY
        if bit32.band(merged_flags, ImGuiDockNodeFlags.NoResize) ~= 0 or bit32.band(merged_flags, no_resize_axis_flag) ~= 0 then
            local window = g.CurrentWindow
            window.DrawList:AddRectFilled(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.Separator), g.Style.FrameRounding)
        else
            -- bb.Min[axis] = bb.Min[axis] + 1 -- Display a little inward so highlight doesn't connect with nearby tabs on the neighbor node.
            -- bb.Max[axis] = bb.Max[axis] - 1
            ImGui.PushID(node.ID)

            -- Find resizing limits by gathering list of nodes that are touching the splitter line.
            local touching_nodes = { [0] = {}, [1] = {} }
            local min_size = g.Style.WindowMinSize[a]
            local resize_limits = { [0] = node.ChildNodes[0].Pos[a] + min_size, [1] = node.ChildNodes[1].Pos[a] + node.ChildNodes[1].Size[a] - min_size }

            local splitter_id = ImGui.GetID("##Splitter")
            if g.ActiveId == splitter_id then -- Only process when splitter is active
                DockNodeTreeUpdateSplitterFindTouchingNode(child_0, axis, 1, touching_nodes[0])
                DockNodeTreeUpdateSplitterFindTouchingNode(child_1, axis, 0, touching_nodes[1])
                for _, tn in ipairs(touching_nodes[0]) do
                    resize_limits[0] = ImMax(resize_limits[0], tn:Rect().Min[a] + min_size)
                end
                for _, tn in ipairs(touching_nodes[1]) do
                    resize_limits[1] = ImMin(resize_limits[1], tn:Rect().Max[a] - min_size)
                end
            end

            -- Use a short delay before highlighting the splitter (and changing the mouse cursor) in order for regular mouse movement to not highlight many splitters
            local cur_size_0 = child_0.Size[a]
            local cur_size_1 = child_1.Size[a]
            local min_size_0 = resize_limits[0] - child_0.Pos[a]
            local min_size_1 = child_1.Pos[a] + child_1.Size[a] - resize_limits[1]
            local bg_col = ImGui.GetColorU32(ImGuiCol.WindowBg)
            local changed
            changed, cur_size_0, cur_size_1 = ImGui.SplitterBehavior(bb, ImGui.GetID("##Splitter"), axis, cur_size_0, cur_size_1, min_size_0, min_size_1, g.WindowsBorderHoverPadding, WINDOWS_RESIZE_FROM_EDGES_FEEDBACK_TIMER, bg_col)
            if changed then
                if #touching_nodes[0] > 0 and #touching_nodes[1] > 0 then
                    child_0.Size[a] = cur_size_0; child_0.SizeRef[a] = cur_size_0
                    child_1.Pos[a] = child_1.Pos[a] - (cur_size_1 - child_1.Size[a])
                    child_1.Size[a] = cur_size_1; child_1.SizeRef[a] = cur_size_1

                    -- Lock the size of every node that is a sibling of the node we are touching
                    -- This might be less desirable if we can merge sibling of a same axis into the same parental level.
                    for side_n = 0, 1 do
                        for _, touching_node in ipairs(touching_nodes[side_n]) do
                            while touching_node.ParentNode ~= node do
                                if touching_node.ParentNode.SplitAxis == axis then
                                    -- Mark other node so its size will be preserved during the upcoming call to DockNodeTreeUpdatePosSize().
                                    local node_to_preserve = touching_node.ParentNode.ChildNodes[side_n]
                                    node_to_preserve.WantLockSizeOnce = true
                                end
                                touching_node = touching_node.ParentNode
                            end
                        end
                    end

                    ImGui.DockNodeTreeUpdatePosSize(child_0, child_0.Pos, child_0.Size)
                    ImGui.DockNodeTreeUpdatePosSize(child_1, child_1.Pos, child_1.Size)
                    ImGui.MarkIniSettingsDirty()
                end
            end
            ImGui.PopID()
        end
    end

    if child_0.IsVisible then ImGui.DockNodeTreeUpdateSplitter(child_0) end
    if child_1.IsVisible then ImGui.DockNodeTreeUpdateSplitter(child_1) end
end

function ImGui.DockNodeTreeFindFallbackLeafNode(node)
    if node:IsLeafNode() then return node end
    local leaf_node = ImGui.DockNodeTreeFindFallbackLeafNode(node.ChildNodes[0])
    if leaf_node then return leaf_node end
    leaf_node = ImGui.DockNodeTreeFindFallbackLeafNode(node.ChildNodes[1])
    if leaf_node then return leaf_node end
    return nil
end

function ImGui.DockNodeTreeFindVisibleNodeByPos(node, pos)
    if not node.IsVisible then return nil end

    local r = ImRect(node.Pos, node.Pos + node.Size)
    if not r:Contains(pos) then return nil end
    if node:IsLeafNode() then return node end
    local hovered_node = ImGui.DockNodeTreeFindVisibleNodeByPos(node.ChildNodes[0], pos)
    if hovered_node then return hovered_node end
    hovered_node = ImGui.DockNodeTreeFindVisibleNodeByPos(node.ChildNodes[1], pos)
    if hovered_node then return hovered_node end

    -- This means we are hovering over the splitter/spacing of a parent node
    return node
end

-------------------------------------------------------------------------------
-- Docking: Public Functions (SetWindowDock, DockSpace, DockSpaceOverViewport)
-------------------------------------------------------------------------------
-- - SetWindowDock() [Internal]
-- - DockSpace()
-- - DockSpaceOverViewport()
-------------------------------------------------------------------------------

-- [Internal] Called via SetNextWindowDockID()
function ImGui.SetWindowDock(window, dock_id, cond)
    -- Test condition (NB: bit 0 is always true) and clear flags for next time
    if cond and cond ~= 0 and bit32.band(window.SetWindowDockAllowFlags, cond) == 0 then return end
    window.SetWindowDockAllowFlags = bit32.band(window.SetWindowDockAllowFlags, bit32.bnot(bit32.bor(ImGuiCond.Once, ImGuiCond.FirstUseEver, ImGuiCond.Appearing)))

    if window.DockId == dock_id then return end

    -- If the user attempt to set a dock id that is a split node, we'll dig within to find a suitable docking spot
    local g = ImGui.GetCurrentContext()
    local new_node = ImGui.DockContextFindNodeByID(g, dock_id)
    if new_node and new_node:IsSplitNode() then
        -- Policy: Find central node or latest focused node. We first move back to our root node.
        new_node = ImGui.DockNodeGetRootNode(new_node)
        if new_node.CentralNode then
            IM_ASSERT(new_node.CentralNode:IsCentralNode())
            dock_id = new_node.CentralNode.ID
        else
            dock_id = new_node.LastFocusedNodeId
        end
    end

    if window.DockId == dock_id then return end

    if window.DockNode then ImGui.DockNodeRemoveWindow(window.DockNode, window, 0) end
    window.DockId = dock_id
end

-- Create an explicit dockspace node within an existing window. Also expose dock node flags and creates a CentralNode by default.
-- The Central Node is always displayed even when empty and shrink/extend according to the requested size of its neighbors.
-- DockSpace() needs to be submitted _before_ any window they can host. If you use a dockspace, submit it early in your app.
-- When ImGuiDockNodeFlags.KeepAliveOnly is set, nothing is submitted in the current window (function may be called from any location).
function ImGui.DockSpace(dockspace_id, size_arg, flags, window_class)
    if size_arg == nil then size_arg = ImVec2(0, 0) end
    if flags == nil then flags = 0 end
    local g = ImGui.GetCurrentContext()
    local window = ImGui.GetCurrentWindowRead()
    if bit32.band(g.IO.ConfigFlags, ImGuiConfigFlags.DockingEnable) == 0 then return 0 end

    -- Early out if parent window is hidden/collapsed
    -- This is faster but also DockNodeUpdateTabBar() relies on TabBarLayout() running (which won't if SkipItems=true) to set NextSelectedTabId = 0). See #2960.
    -- If for whichever reason this is causing problem we would need to ensure that DockNodeUpdateTabBar() ends up clearing NextSelectedTabId even if SkipItems=true.
    if window.SkipItems then flags = bit32.bor(flags, ImGuiDockNodeFlags.KeepAliveOnly) end
    if bit32.band(flags, ImGuiDockNodeFlags.KeepAliveOnly) == 0 then window = ImGui.GetCurrentWindow() end -- call to set window.WriteAccessed = true;

    IM_ASSERT(bit32.band(flags, ImGuiDockNodeFlags.DockSpace) == 0) -- Flag is automatically set by DockSpace() as LocalFlags, not SharedFlags!
    IM_ASSERT(bit32.band(flags, ImGuiDockNodeFlags.CentralNode) == 0) -- Flag is automatically set by DockSpace() as LocalFlags, not SharedFlags! (#8145)

    IM_ASSERT(dockspace_id ~= 0)
    local node = ImGui.DockContextFindNodeByID(g, dockspace_id)
    if node == nil then
        node = ImGui.DockContextAddNode(g, dockspace_id)
        node:SetLocalFlags(ImGuiDockNodeFlags.CentralNode)
    end
    node.SharedFlags = flags
    node.WindowClass = window_class or ImGuiWindowClass()

    -- When a DockSpace transitioned form implicit to explicit this may be called a second time
    -- It is possible that the node has already been claimed by a docked window which appeared before the DockSpace() node, so we overwrite IsDockSpace again.
    if node.LastFrameActive == g.FrameCount and bit32.band(flags, ImGuiDockNodeFlags.KeepAliveOnly) == 0 then
        IM_ASSERT(node:IsDockSpace() == false, "Cannot call DockSpace() twice a frame with the same ID")
        node:SetLocalFlags(bit32.bor(node.LocalFlags, ImGuiDockNodeFlags.DockSpace))
        return dockspace_id
    end
    node:SetLocalFlags(bit32.bor(node.LocalFlags, ImGuiDockNodeFlags.DockSpace))

    -- Keep alive mode, this is allow windows docked into this node so stay docked even if they are not visible
    if bit32.band(flags, ImGuiDockNodeFlags.KeepAliveOnly) ~= 0 then
        node.LastFrameAlive = g.FrameCount
        return dockspace_id
    end

    local content_avail = ImGui.GetContentRegionAvail()
    local size = ImVec2(ImTrunc(size_arg.x), ImTrunc(size_arg.y))
    if size.x <= 0.0 then size.x = ImMax(content_avail.x + size.x, 4.0) end -- Arbitrary minimum child size (0.0f causing too much issues)
    if size.y <= 0.0 then size.y = ImMax(content_avail.y + size.y, 4.0) end
    IM_ASSERT(size.x > 0.0 and size.y > 0.0)

    node.Pos = ImVec2(window.DC.CursorPos.x, window.DC.CursorPos.y)
    node.Size = ImVec2(size.x, size.y)
    node.SizeRef = ImVec2(size.x, size.y)
    ImGui.SetNextWindowPos(node.Pos)
    ImGui.SetNextWindowSize(node.Size)
    g.NextWindowData.PosUndock = false

    -- FIXME-DOCK: Why do we need a child window to host a dockspace, could we host it in the existing window?
    -- FIXME-DOCK: What is the reason for not simply calling BeginChild()? (OK to have a reason but should be commented)
    local window_flags = bit32.bor(ImGuiWindowFlags.ChildWindow, ImGuiWindowFlags.DockNodeHost)
    window_flags = bit32.bor(window_flags, ImGuiWindowFlags.NoSavedSettings, ImGuiWindowFlags.NoResize, ImGuiWindowFlags.NoCollapse, ImGuiWindowFlags.NoTitleBar)
    window_flags = bit32.bor(window_flags, ImGuiWindowFlags.NoScrollbar, ImGuiWindowFlags.NoScrollWithMouse)
    window_flags = bit32.bor(window_flags, ImGuiWindowFlags.NoBackground)

    local title = string.format("%s/DockSpace_%08X", window.Name, dockspace_id)

    ImGui.PushStyleVar(ImGuiStyleVar.ChildBorderSize, 0.0)
    ImGui.Begin(title, nil, window_flags)
    ImGui.PopStyleVar()

    local host_window = g.CurrentWindow
    DockNodeSetupHostWindow(node, host_window)
    host_window.ChildId = window:GetID(title)
    node.OnlyNodeWithWindows = nil

    IM_ASSERT(node:IsRootNode())

    -- We need to handle the rare case were a central node is missing.
    -- This can happen if the node was first created manually with DockBuilderAddNode() but _without_ the ImGuiDockNodeFlags.Dockspace.
    -- Doing it correctly would set the _CentralNode flags, which would then propagate according to subsequent split.
    -- It would also be ambiguous to attempt to assign a central node while there are split nodes, so we wait until there's a single node remaining.
    -- The specific sub-property of _CentralNode we are interested in recovering here is the "Don't delete when empty" property,
    -- as it doesn't make sense for an empty dockspace to not have this property.
    if node:IsLeafNode() and not node:IsCentralNode() then
        node:SetLocalFlags(bit32.bor(node.LocalFlags, ImGuiDockNodeFlags.CentralNode))
    end

    -- Update the node
    ImGui.DockNodeUpdate(node)

    ImGui.End()

    local bb = ImRect(node.Pos, node.Pos + size)
    ImGui.ItemSize(size)
    ImGui.ItemAdd(bb, dockspace_id, nil, ImGuiItemFlags.NoNav) -- Not a nav point (could be, would need to draw the nav rect and replicate/refactor activation from BeginChild(), but seems like CTRL+Tab works better here?)
    if bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HoveredRect) ~= 0 and ImGui.IsWindowChildOf(g.HoveredWindow, host_window, false, true) then -- To fullfill IsItemHovered(), similar to EndChild()
        g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HoveredWindow)
    end

    return dockspace_id
end

-- Tips: Use with ImGuiDockNodeFlags.PassthruCentralNode!
-- The limitation with this call is that your window won't have a local menu bar, but you can also use BeginMainMenuBar().
-- Even though we could pass window flags, it would also require the user to be able to call BeginMenuBar() somehow meaning we can't Begin/End in a single function.
-- If you really want a menu bar inside the same window as the one hosting the dockspace, you will need to copy this code somewhere and tweak it.
function ImGui.DockSpaceOverViewport(dockspace_id, viewport, dockspace_flags, window_class)
    if dockspace_id == nil then dockspace_id = 0 end
    if dockspace_flags == nil then dockspace_flags = 0 end
    if viewport == nil then viewport = ImGui.GetMainViewport() end

    -- Submit a window filling the entire viewport
    ImGui.SetNextWindowPos(viewport.WorkPos)
    ImGui.SetNextWindowSize(viewport.WorkSize)
    ImGui.SetNextWindowViewport(viewport.ID)

    local host_window_flags = 0
    host_window_flags = bit32.bor(host_window_flags, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoCollapse, ImGuiWindowFlags.NoResize, ImGuiWindowFlags.NoMove, ImGuiWindowFlags.NoDocking)
    host_window_flags = bit32.bor(host_window_flags, ImGuiWindowFlags.NoBringToFrontOnFocus, ImGuiWindowFlags.NoNavFocus)
    if bit32.band(dockspace_flags, ImGuiDockNodeFlags.PassthruCentralNode) ~= 0 then
        host_window_flags = bit32.bor(host_window_flags, ImGuiWindowFlags.NoBackground)
    end

    -- FIXME-OPT: When using ImGuiDockNodeFlags.KeepAliveOnly with DockSpaceOverViewport() we might be able to spare submitting the window,
    -- since DockSpace() with that flag doesn't need a window. We'd only need to compute the default ID accordingly.
    if bit32.band(dockspace_flags, ImGuiDockNodeFlags.KeepAliveOnly) ~= 0 then
        host_window_flags = bit32.bor(host_window_flags, ImGuiWindowFlags.NoMouseInputs)
    end

    local label = string.format("WindowOverViewport_%08X", viewport.ID)

    ImGui.PushStyleVar(ImGuiStyleVar.WindowRounding, 0.0)
    ImGui.PushStyleVar(ImGuiStyleVar.WindowBorderSize, 0.0)
    ImGui.PushStyleVar(ImGuiStyleVar.WindowPadding, ImVec2(0.0, 0.0))
    ImGui.Begin(label, nil, host_window_flags)
    ImGui.PopStyleVar(3)

    -- Submit the dockspace
    if dockspace_id == 0 then dockspace_id = ImGui.GetID("DockSpace") end
    ImGui.DockSpace(dockspace_id, ImVec2(0.0, 0.0), dockspace_flags, window_class)

    ImGui.End()

    return dockspace_id
end

-------------------------------------------------------------------------------
-- Docking: Builder Functions
-------------------------------------------------------------------------------
-- Very early end-user API to manipulate dock nodes.
-- Only available in imgui_internal.h. Expect this API to change/break!
-- It is expected that those functions are all called _before_ the dockspace node submission.
-------------------------------------------------------------------------------
-- - DockBuilderDockWindow()
-- - DockBuilderGetNode()
-- - DockBuilderSetNodePos()
-- - DockBuilderSetNodeSize()
-- - DockBuilderAddNode()
-- - DockBuilderRemoveNode()
-- - DockBuilderRemoveNodeChildNodes()
-- - DockBuilderRemoveNodeDockedWindows()
-- - DockBuilderSplitNode()
-- - DockBuilderCopyNodeRec()
-- - DockBuilderCopyNode()
-- - DockBuilderCopyWindowSettings()
-- - DockBuilderCopyDockSpace()
-- - DockBuilderFinish()
-------------------------------------------------------------------------------

function ImGui.DockBuilderDockWindow(window_name, node_id)
    -- We don't preserve relative order of multiple docked windows (by clearing DockOrder back to -1)
    local window_id = ImHashStr(window_name)
    local window = ImGui.FindWindowByID(window_id)
    if window then
        -- Apply to created window
        local prev_node_id = window.DockId
        ImGui.SetWindowDock(window, node_id, ImGuiCond.Always)
        if window.DockId ~= prev_node_id then window.DockOrder = -1 end
    else
        -- Apply to settings
        local settings = ImGui.FindWindowSettingsByID(window_id)
        if settings == nil then settings = ImGui.CreateNewWindowSettings(window_name) end
        if settings.DockId ~= node_id then settings.DockOrder = -1 end
        settings.DockId = node_id
    end
end

function ImGui.DockBuilderGetNode(node_id)
    return ImGui.DockContextFindNodeByID(ImGui.GetCurrentContext(), node_id)
end

function ImGui.DockBuilderGetCentralNode(node_id)
    local node = ImGui.DockBuilderGetNode(node_id)
    if not node then return nil end
    return ImGui.DockNodeGetRootNode(node).CentralNode
end

function ImGui.DockBuilderSetNodePos(node_id, pos)
    local node = ImGui.DockContextFindNodeByID(ImGui.GetCurrentContext(), node_id)
    if node == nil then return end
    node.Pos = ImVec2(pos.x, pos.y)
    node.AuthorityForPos = ImGuiDataAuthority.DockNode
end

function ImGui.DockBuilderSetNodeSize(node_id, size)
    local node = ImGui.DockContextFindNodeByID(ImGui.GetCurrentContext(), node_id)
    if node == nil then return end
    IM_ASSERT(size.x > 0.0 and size.y > 0.0)
    node.Size = ImVec2(size.x, size.y)
    node.SizeRef = ImVec2(size.x, size.y)
    node.AuthorityForSize = ImGuiDataAuthority.DockNode
end

-- Make sure to use the ImGuiDockNodeFlags.DockSpace flag to create a dockspace node! Otherwise this will create a floating node!
-- - Floating node: you can then call DockBuilderSetNodePos()/DockBuilderSetNodeSize() to position and size the floating node.
-- - Dockspace node: calling DockBuilderSetNodePos() is unnecessary.
-- - If you intend to split a node immediately after creation using DockBuilderSplitNode(), make sure to call DockBuilderSetNodeSize() beforehand!
--   For various reason, the splitting code currently needs a base size otherwise space may not be allocated as precisely as you would expect.
-- - Use (id == 0) to let the system allocate a node identifier.
-- - Existing node with a same id will be removed.
function ImGui.DockBuilderAddNode(node_id, flags)
    if node_id == nil then node_id = 0 end
    if flags == nil then flags = 0 end
    local g = ImGui.GetCurrentContext()
    if node_id ~= 0 then ImGui.DockBuilderRemoveNode(node_id) end

    local node
    if bit32.band(flags, ImGuiDockNodeFlags.DockSpace) ~= 0 then
        ImGui.DockSpace(node_id, ImVec2(0, 0), bit32.bor(bit32.band(flags, bit32.bnot(ImGuiDockNodeFlags.DockSpace)), ImGuiDockNodeFlags.KeepAliveOnly))
        node = ImGui.DockContextFindNodeByID(g, node_id)
    else
        node = ImGui.DockContextAddNode(g, node_id)
        node:SetLocalFlags(flags)
    end
    node.LastFrameAlive = g.FrameCount -- Set this otherwise BeginDocked will undock during the same frame.
    return node.ID
end

function ImGui.DockBuilderRemoveNode(node_id)
    local g = ImGui.GetCurrentContext()
    local node = ImGui.DockContextFindNodeByID(g, node_id)
    if node == nil then return end
    ImGui.DockBuilderRemoveNodeDockedWindows(node_id, true)
    ImGui.DockBuilderRemoveNodeChildNodes(node_id)
    -- Node may have moved or deleted if e.g. any merge happened
    node = ImGui.DockContextFindNodeByID(g, node_id)
    if node == nil then return end
    if node:IsCentralNode() and node.ParentNode then
        node.ParentNode:SetLocalFlags(bit32.bor(node.ParentNode.LocalFlags, ImGuiDockNodeFlags.CentralNode))
    end
    ImGui.DockContextRemoveNode(g, node, true)
end

-- root_id = 0 to remove all, root_id != 0 to remove child of given node.
function ImGui.DockBuilderRemoveNodeChildNodes(root_id)
    local g = ImGui.GetCurrentContext()
    local dc = g.DockContext

    local root_node = (root_id ~= 0) and ImGui.DockContextFindNodeByID(g, root_id) or nil
    if root_id ~= 0 and root_node == nil then return end
    local has_central_node = false

    local backup_root_node_authority_for_pos = root_node and root_node.AuthorityForPos or ImGuiDataAuthority.Auto
    local backup_root_node_authority_for_size = root_node and root_node.AuthorityForSize or ImGuiDataAuthority.Auto

    -- Process active windows
    local nodes_to_remove = {}
    for _, id in ipairs(DockContextNodesSorted(g)) do
        local node = dc.Nodes[id]
        if node then
            local want_removal = (root_id == 0) or (node.ID ~= root_id and ImGui.DockNodeGetRootNode(node).ID == root_id)
            if want_removal then
                if node:IsCentralNode() then has_central_node = true end
                if root_id ~= 0 then ImGui.DockContextQueueNotifyRemovedNode(g, node) end
                if root_node then
                    ImGui.DockNodeMoveWindows(root_node, node)
                    DockSettingsRenameNodeReferences(node.ID, root_node.ID)
                end
                table.insert(nodes_to_remove, node)
            end
        end
    end

    -- DockNodeMoveWindows->DockNodeAddWindow will normally set those when reaching two windows (which is only adequate during interactive merge)
    -- Make sure we don't lose our current pos/size. (FIXME-DOCK: Consider tidying up that code in DockNodeAddWindow instead)
    if root_node then
        root_node.AuthorityForPos = backup_root_node_authority_for_pos
        root_node.AuthorityForSize = backup_root_node_authority_for_size
    end

    -- Apply to settings
    for _, settings in g.SettingsWindows:iter() do
        local window_settings_dock_id = settings.DockId
        if window_settings_dock_id and window_settings_dock_id ~= 0 then
            for _, n in ipairs(nodes_to_remove) do
                if n.ID == window_settings_dock_id then
                    settings.DockId = root_id
                    break
                end
            end
        end
    end

    -- Not really efficient, but easier to destroy a whole hierarchy considering DockContextRemoveNode is attempting to merge nodes
    if #nodes_to_remove > 1 then
        local depth = {}
        for _, n in ipairs(nodes_to_remove) do depth[n] = ImGui.DockNodeGetDepth(n) end
        table.sort(nodes_to_remove, function(a, b) return depth[a] > depth[b] end)
    end
    for _, n in ipairs(nodes_to_remove) do
        ImGui.DockContextRemoveNode(g, n, false)
    end

    if root_id == 0 then
        dc.Nodes = {}
        dc.Requests:clear()
    elseif has_central_node then
        root_node.CentralNode = root_node
        root_node:SetLocalFlags(bit32.bor(root_node.LocalFlags, ImGuiDockNodeFlags.CentralNode))
    end
end

function ImGui.DockBuilderRemoveNodeDockedWindows(root_id, clear_settings_refs)
    if clear_settings_refs == nil then clear_settings_refs = true end
    -- Clear references in settings
    local g = ImGui.GetCurrentContext()
    if clear_settings_refs then
        for _, settings in g.SettingsWindows:iter() do
            local want_removal = (root_id == 0) or (settings.DockId == root_id)
            if not want_removal and settings.DockId ~= 0 then
                local node = ImGui.DockContextFindNodeByID(g, settings.DockId)
                if node and ImGui.DockNodeGetRootNode(node).ID == root_id then want_removal = true end
            end
            if want_removal then settings.DockId = 0 end
        end
    end

    -- Clear references in windows
    for n = 1, g.Windows.Size do
        local window = g.Windows.Data[n]
        local want_removal = (root_id == 0) or (window.DockNode and ImGui.DockNodeGetRootNode(window.DockNode).ID == root_id) or (window.DockNodeAsHost and window.DockNodeAsHost.ID == root_id)
        if want_removal then
            local backup_dock_id = window.DockId
            ImGui.DockContextProcessUndockWindow(g, window, clear_settings_refs)
            if not clear_settings_refs then IM_ASSERT(window.DockId == backup_dock_id) end
        end
    end
end

-- Returns (id_at_dir, id_at_opposite_dir): the IDs of the two new nodes created.
-- First return value is ID of the node at the specified direction.
-- FIXME-DOCK: We are not exposing nor using split_outer.
--- @return ImGuiID id_at_dir, ImGuiID id_at_opposite_dir
function ImGui.DockBuilderSplitNode(id, split_dir, size_ratio_for_node_at_dir)
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(split_dir ~= ImGuiDir.None)

    local node = ImGui.DockContextFindNodeByID(g, id)
    if node == nil then
        IM_ASSERT(node ~= nil)
        return 0, 0
    end

    local req = ImGuiDockRequest()
    req.Type = ImGuiDockRequestType.Split
    req.DockTargetWindow = nil
    req.DockTargetNode = node
    req.DockPayload = nil
    req.DockSplitDir = split_dir
    req.DockSplitRatio = ImSaturate((split_dir == ImGuiDir.Left or split_dir == ImGuiDir.Up) and size_ratio_for_node_at_dir or (1.0 - size_ratio_for_node_at_dir))
    req.DockSplitOuter = false
    ImGui.DockContextProcessDock(g, req)

    local first = (split_dir == ImGuiDir.Left or split_dir == ImGuiDir.Up)
    local id_at_dir = node.ChildNodes[first and 0 or 1].ID
    local id_at_opposite_dir = node.ChildNodes[first and 1 or 0].ID
    return id_at_dir, id_at_opposite_dir
end

local function DockBuilderCopyNodeRec(src_node, dst_node_id_if_known, out_node_remap_pairs)
    local g = ImGui.GetCurrentContext()
    local dst_node = ImGui.DockContextAddNode(g, dst_node_id_if_known)
    dst_node.SharedFlags = src_node.SharedFlags
    dst_node.LocalFlags = src_node.LocalFlags
    dst_node.LocalFlagsInWindows = ImGuiDockNodeFlags.None
    dst_node.Pos = ImVec2(src_node.Pos.x, src_node.Pos.y)
    dst_node.Size = ImVec2(src_node.Size.x, src_node.Size.y)
    dst_node.SizeRef = ImVec2(src_node.SizeRef.x, src_node.SizeRef.y)
    dst_node.SplitAxis = src_node.SplitAxis
    dst_node:UpdateMergedFlags()

    table.insert(out_node_remap_pairs, src_node.ID)
    table.insert(out_node_remap_pairs, dst_node.ID)

    for child_n = 0, 1 do
        if src_node.ChildNodes[child_n] then
            dst_node.ChildNodes[child_n] = DockBuilderCopyNodeRec(src_node.ChildNodes[child_n], 0, out_node_remap_pairs)
            dst_node.ChildNodes[child_n].ParentNode = dst_node
        end
    end
    return dst_node
end

--- @param out_node_remap_pairs table # 1-based array, cleared and filled with (src_id, dst_id) pairs
function ImGui.DockBuilderCopyNode(src_node_id, dst_node_id, out_node_remap_pairs)
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(src_node_id ~= 0)
    IM_ASSERT(dst_node_id ~= 0)
    IM_ASSERT(out_node_remap_pairs ~= nil)

    ImGui.DockBuilderRemoveNode(dst_node_id)

    local src_node = ImGui.DockContextFindNodeByID(g, src_node_id)
    IM_ASSERT(src_node ~= nil)

    for k in pairs(out_node_remap_pairs) do out_node_remap_pairs[k] = nil end
    DockBuilderCopyNodeRec(src_node, dst_node_id, out_node_remap_pairs)
    IM_ASSERT((#out_node_remap_pairs % 2) == 0)
end

function ImGui.DockBuilderCopyWindowSettings(src_name, dst_name)
    local src_window = ImGui.FindWindowByName(src_name)
    if src_window == nil then return end
    local dst_window = ImGui.FindWindowByName(dst_name)
    if dst_window then
        ImVec2_Copy(dst_window.Pos, src_window.Pos)
        ImVec2_Copy(dst_window.Size, src_window.Size)
        ImVec2_Copy(dst_window.SizeFull, src_window.SizeFull)
        dst_window.Collapsed = src_window.Collapsed
    else
        local dst_settings = ImGui.FindWindowSettingsByID(ImHashStr(dst_name))
        if not dst_settings then dst_settings = ImGui.CreateNewWindowSettings(dst_name) end
        local wx, wy = ImTrunc(src_window.Pos.x), ImTrunc(src_window.Pos.y)
        if src_window.ViewportId ~= 0 and src_window.ViewportId ~= 0x11111111 then
            ImVec2_CopyV(dst_settings.ViewportPos, wx, wy)
            dst_settings.ViewportId = src_window.ViewportId
            ImVec2_CopyV(dst_settings.Pos, 0, 0)
        else
            ImVec2_CopyV(dst_settings.Pos, wx, wy)
        end
        ImVec2_CopyV(dst_settings.Size, ImTrunc(src_window.SizeFull.x), ImTrunc(src_window.SizeFull.y))
        dst_settings.Collapsed = src_window.Collapsed
    end
end

-- FIXME: Will probably want to change this signature, in particular how the window remapping pairs are passed.
--- @param in_window_remap_pairs table # 1-based array of window names: src0, dst0, src1, dst1, ...
function ImGui.DockBuilderCopyDockSpace(src_dockspace_id, dst_dockspace_id, in_window_remap_pairs)
    IM_ASSERT(src_dockspace_id ~= 0)
    IM_ASSERT(dst_dockspace_id ~= 0)
    IM_ASSERT(in_window_remap_pairs ~= nil)
    IM_ASSERT((#in_window_remap_pairs % 2) == 0)

    -- Duplicate entire dock
    -- FIXME: When overwriting dst_dockspace_id, windows that aren't part of our dockspace window class but that are docked in a same node will be split apart,
    -- whereas we could attempt to at least keep them together in a new, same floating node.
    local node_remap_pairs = {}
    ImGui.DockBuilderCopyNode(src_dockspace_id, dst_dockspace_id, node_remap_pairs)

    -- Attempt to transition all the upcoming windows associated to dst_dockspace_id into the newly created hierarchy of dock nodes
    -- (The windows associated to src_dockspace_id are staying in place)
    local src_windows = {}
    for remap_window_n = 1, #in_window_remap_pairs, 2 do
        local src_window_name = in_window_remap_pairs[remap_window_n]
        local dst_window_name = in_window_remap_pairs[remap_window_n + 1]
        local src_window_id = ImHashStr(src_window_name)
        src_windows[src_window_id] = true

        -- Search in the remapping tables
        local src_dock_id = 0
        local src_window = ImGui.FindWindowByID(src_window_id)
        if src_window then
            src_dock_id = src_window.DockId
        else
            local src_window_settings = ImGui.FindWindowSettingsByID(src_window_id)
            if src_window_settings then src_dock_id = src_window_settings.DockId end
        end
        local dst_dock_id = 0
        for dock_remap_n = 1, #node_remap_pairs, 2 do
            if node_remap_pairs[dock_remap_n] == src_dock_id then
                dst_dock_id = node_remap_pairs[dock_remap_n + 1]
                --node_remap_pairs[dock_remap_n] = node_remap_pairs[dock_remap_n + 1] = 0 -- Clear
                break
            end
        end

        if dst_dock_id ~= 0 then
            -- Docked windows gets redocked into the new node hierarchy.
            ImGui.DockBuilderDockWindow(dst_window_name, dst_dock_id)
        else
            -- Floating windows gets their settings transferred (regardless of whether the new window already exist or not)
            -- When this is leading to a Copy and not a Move, we would get two overlapping floating windows. Could we possibly dock them together?
            ImGui.DockBuilderCopyWindowSettings(src_window_name, dst_window_name)
        end
    end

    -- Anything else in the source nodes of 'node_remap_pairs' are windows that are not included in the remapping list.
    -- Find those windows and move to them to the cloned dock node. This may be optional?
    -- Dock those are a second step as undocking would invalidate source dock nodes.
    local dock_remaining_windows = {}
    for dock_remap_n = 1, #node_remap_pairs, 2 do
        local src_dock_id = node_remap_pairs[dock_remap_n]
        if src_dock_id ~= 0 then
            local dst_dock_id = node_remap_pairs[dock_remap_n + 1]
            local node = ImGui.DockBuilderGetNode(src_dock_id)
            for _, window in node.Windows:iter() do
                if not src_windows[window.ID] then
                    -- Docked windows gets redocked into the new node hierarchy.
                    table.insert(dock_remaining_windows, { Window = window, DockId = dst_dock_id })
                end
            end
        end
    end
    for _, task in ipairs(dock_remaining_windows) do
        ImGui.DockBuilderDockWindow(task.Window.Name, task.DockId)
    end
end

-- FIXME-DOCK: This is awkward because in series of split user is likely to loose access to its root node.
function ImGui.DockBuilderFinish(root_id)
    --DockContextRebuild(g)
    ImGui.DockContextBuildAddWindowsToNodes(ImGui.GetCurrentContext(), root_id)
end

-------------------------------------------------------------------------------
-- Docking: Begin/End Support Functions (called from Begin/End)
-------------------------------------------------------------------------------
-- - GetWindowAlwaysWantOwnTabBar()
-- - DockContextBindNodeToWindow()
-- - BeginDocked()
-- - BeginDockableDragDropSource()
-- - BeginDockableDragDropTarget()
-------------------------------------------------------------------------------

function ImGui.GetWindowAlwaysWantOwnTabBar(window)
    local g = ImGui.GetCurrentContext()
    if g.IO.ConfigDockingAlwaysTabBar or window.WindowClass.DockingAlwaysTabBar then
        if bit32.band(window.Flags, bit32.bor(ImGuiWindowFlags.ChildWindow, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoDocking)) == 0 then
            if not window.IsFallbackWindow then return true end -- We don't support AlwaysTabBar on the fallback/implicit window to avoid unused dock-node overhead/noise
        end
    end
    return false
end

function ImGui.DockContextBindNodeToWindow(ctx, window)
    local g = ctx
    local node = ImGui.DockContextFindNodeByID(ctx, window.DockId)
    IM_ASSERT(window.DockNode == nil)

    -- We should not be docking into a split node (SetWindowDock should avoid this)
    if node and node:IsSplitNode() then
        ImGui.DockContextProcessUndockWindow(ctx, window)
        return nil
    end

    -- Create node
    if node == nil then
        node = ImGui.DockContextAddNode(ctx, window.DockId)
        node.AuthorityForPos = ImGuiDataAuthority.Window
        node.AuthorityForSize = ImGuiDataAuthority.Window
        node.AuthorityForViewport = ImGuiDataAuthority.Window
        node.LastFrameAlive = g.FrameCount
    end

    -- If the node just turned visible and is part of a hierarchy, it doesn't have a Size assigned by DockNodeTreeUpdatePosSize() yet,
    -- so we're forcing a Pos/Size update from the first ancestor that is already visible (often it will be the root node).
    -- If we don't do this, the window will be assigned a zero-size on its first frame, which won't ideally warm up the layout.
    -- This is a little wonky because we don't normally update the Pos/Size of visible node mid-frame.
    if not node.IsVisible then
        local ancestor_node = node
        while not ancestor_node.IsVisible and ancestor_node.ParentNode do
            ancestor_node = ancestor_node.ParentNode
        end
        IM_ASSERT(ancestor_node.Size.x > 0.0 and ancestor_node.Size.y > 0.0)
        ImGui.DockNodeUpdateHasCentralNodeChild(ImGui.DockNodeGetRootNode(ancestor_node))
        ImGui.DockNodeTreeUpdatePosSize(ancestor_node, ancestor_node.Pos, ancestor_node.Size, node)
    end

    -- Add window to node
    local node_was_visible = node.IsVisible
    ImGui.DockNodeAddWindow(node, window, true)
    node.IsVisible = node_was_visible -- Don't mark visible right away (so DockContextEndFrame() doesn't render it, maybe other side effects? will see)
    IM_ASSERT(node == window.DockNode)
    return node
end

local function StoreDockStyleForWindow(window)
    local g = ImGui.GetCurrentContext()
    for color_n = 0, ImGuiWindowDockStyleCol.COUNT - 1 do
        window.DockStyle.Colors[color_n] = ImGui.ColorConvertFloat4ToU32(g.Style.Colors[GWindowDockStyleColors[color_n]])
    end
end
ImGui.StoreDockStyleForWindow = StoreDockStyleForWindow

--- @return bool? p_open
function ImGui.BeginDocked(window, p_open)
    local g = ImGui.GetCurrentContext()

    -- Specific extra processing for fallback window (#9151), could be in Begin() as well.
    if window.IsFallbackWindow and not window.WasActive then
        DockNodeHideWindowDuringHostWindowCreation(window)
        return p_open
    end

    local auto_dock_node = ImGui.GetWindowAlwaysWantOwnTabBar(window)
    if auto_dock_node then
        if window.DockId == 0 then
            IM_ASSERT(window.DockNode == nil)
            window.DockId = ImGui.DockContextGenNodeID(g)
        end
    else
        -- Calling SetNextWindowPos() undock windows by default (by setting PosUndock)
        local want_undock = false
        want_undock = want_undock or bit32.band(window.Flags, ImGuiWindowFlags.NoDocking) ~= 0
        want_undock = want_undock or (bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasPos) ~= 0 and bit32.band(window.SetWindowPosAllowFlags, g.NextWindowData.PosCond) ~= 0 and g.NextWindowData.PosUndock)
        if want_undock then
            ImGui.DockContextProcessUndockWindow(g, window)
            return p_open
        end
    end

    -- Bind to our dock node
    local node = window.DockNode
    if node ~= nil then IM_ASSERT(window.DockId == node.ID) end
    if window.DockId ~= 0 and node == nil then
        node = ImGui.DockContextBindNodeToWindow(g, window)
        if node == nil then return p_open end
    end

    -- Undock if our dockspace node disappeared
    -- Note how we are testing for LastFrameAlive and NOT LastFrameActive. A DockSpace node can be maintained alive while being inactive with ImGuiDockNodeFlags.KeepAliveOnly.
    if node.LastFrameAlive < g.FrameCount then
        -- If the window has been orphaned, transition the docknode to an implicit node processed in DockContextNewFrameUpdateDocking()
        local root_node = ImGui.DockNodeGetRootNode(node)
        if root_node.LastFrameAlive < g.FrameCount then
            ImGui.DockContextProcessUndockWindow(g, window)
        else
            window.DockIsActive = true
        end
        return p_open
    end

    -- Store style overrides
    StoreDockStyleForWindow(window)

    -- Fast path return. It is common for windows to hold on a persistent DockId but be the only visible window,
    -- and never create neither a host window neither a tab bar.
    -- FIXME-DOCK: replace .HostWindow nil compare with something more explicit (~was initially intended as a first frame test)
    if node.HostWindow == nil then
        if node.State == ImGuiDockNodeState.HostWindowHiddenBecauseWindowsAreResizing then
            window.DockIsActive = true
        end
        if node.Windows.Size > 1 and window.Appearing then -- Only hide appearing window
            DockNodeHideWindowDuringHostWindowCreation(window)
        end
        return p_open
    end

    -- We can have zero-sized nodes (e.g. children of a small-size dockspace)
    IM_ASSERT(node.HostWindow)
    IM_ASSERT(node:IsLeafNode())
    IM_ASSERT(node.Size.x >= 0.0 and node.Size.y >= 0.0)
    node.State = ImGuiDockNodeState.HostWindowVisible

    -- Undock if we are submitted earlier than the host window
    if bit32.band(node.MergedFlags, ImGuiDockNodeFlags.KeepAliveOnly) == 0 and window.BeginOrderWithinContext < node.HostWindow.BeginOrderWithinContext then
        ImGui.DockContextProcessUndockWindow(g, window)
        return p_open
    end

    -- Position/Size window
    ImGui.SetNextWindowPos(node.Pos)
    ImGui.SetNextWindowSize(node.Size)
    g.NextWindowData.PosUndock = false -- Cancel implicit undocking of SetNextWindowPos()
    window.DockIsActive = true
    window.DockNodeIsVisible = true
    window.DockTabIsVisible = false
    if bit32.band(node.MergedFlags, ImGuiDockNodeFlags.KeepAliveOnly) ~= 0 then return p_open end

    -- When the window is selected we mark it as visible.
    if node.VisibleWindow == window then window.DockTabIsVisible = true end

    -- Update window flag
    IM_ASSERT(bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) == 0)
    window.Flags = bit32.bor(window.Flags, ImGuiWindowFlags.ChildWindow, ImGuiWindowFlags.NoResize)
    window.ChildFlags = bit32.bor(window.ChildFlags, ImGuiChildFlags.AlwaysUseWindowPadding)
    if node:IsHiddenTabBar() or node:IsNoTabBar() then
        window.Flags = bit32.bor(window.Flags, ImGuiWindowFlags.NoTitleBar)
    else
        window.Flags = bit32.band(window.Flags, bit32.bnot(ImGuiWindowFlags.NoTitleBar)) -- Clear the NoTitleBar flag in case the user set it: confusingly enough we need a title bar height so we are correctly offset, but it won't be displayed!
    end

    -- Save new dock order only if the window has been visible once already
    -- This allows multiple windows to be created in the same frame and have their respective dock orders preserved.
    if node.TabBar and window.WasActive then
        window.DockOrder = ImGui.DockNodeGetTabOrder(window)
    end

    if (node.WantCloseAll or node.WantCloseTabId == window.TabId) and p_open ~= nil then
        p_open = false
    end

    -- Update ChildId to allow returning from Child to Parent with Escape
    local parent_window = window.DockNode.HostWindow
    window.ChildId = parent_window:GetID(window.Name)
    return p_open
end

function ImGui.BeginDockableDragDropSource(window)
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(g.ActiveId == window.MoveId)
    IM_ASSERT(g.MovingWindow == window)
    IM_ASSERT(g.CurrentWindow == window)

    -- 0: Hold SHIFT to disable docking, 1: Hold SHIFT to enable docking.
    if g.IO.ConfigDockingWithShift ~= g.IO.KeyShift then
        -- When ConfigDockingWithShift is set, display a tooltip to increase UI affordance.
        -- We cannot set for HoveredWindowUnderMovingWindow ~= nil here, as it is only valid/useful when drag and drop is already active
        -- (because of the 'is_mouse_dragging_with_an_expected_destination' logic in UpdateViewportsNewFrame() function)
        if g.IO.ConfigDockingWithShift and g.MouseStationaryTimer >= 1.0 and g.ActiveId >= 1 then
            ImGui.SetTooltip("%s", ImGui.LocalizeGetMsg(ImGuiLocKey.DockingHoldShiftToDock))
        end
        return
    end

    g.LastItemData.ID = window.MoveId
    window = window.RootWindowDockTree
    IM_ASSERT(bit32.band(window.Flags, ImGuiWindowFlags.NoDocking) == 0)
    local is_drag_docking = g.IO.ConfigDockingWithShift or ImRect(0, 0, window.SizeFull.x, ImGui.GetFrameHeight()):Contains(g.ActiveIdClickOffset) -- FIXME-DOCKING: Need to make this stateful and explicit
    local drag_drop_flags = bit32.bor(ImGuiDragDropFlags.SourceNoPreviewTooltip, ImGuiDragDropFlags.SourceNoHoldToOpenOthers, ImGuiDragDropFlags.PayloadAutoExpire, ImGuiDragDropFlags.PayloadNoCrossContext, ImGuiDragDropFlags.PayloadNoCrossProcess)
    if is_drag_docking and ImGui.BeginDragDropSource(drag_drop_flags) then
        ImGui.SetDragDropPayload(IMGUI_PAYLOAD_TYPE_WINDOW, window)
        ImGui.EndDragDropSource()
        StoreDockStyleForWindow(window) -- Store style overrides while dragging (even when not docked) because docking preview may need it.
    end
end

function ImGui.BeginDockableDragDropTarget(window)
    local g = ImGui.GetCurrentContext()

    --IM_ASSERT(window.RootWindowDockTree == window) -- May also be a DockSpace
    IM_ASSERT(bit32.band(window.Flags, ImGuiWindowFlags.NoDocking) == 0)
    if not g.DragDropActive then return end
    --GetForegroundDrawList(window):AddRect(window.Pos, window.Pos + window.Size, IM_COL32(255, 255, 0, 255))
    if not ImGui.BeginDragDropTargetCustom(window:Rect(), window.ID) then return end

    -- Peek into the payload before calling AcceptDragDropPayload() so we can handle overlapping dock nodes with filtering
    -- (this is a little unusual pattern, normally most code would call AcceptDragDropPayload directly)
    local payload = g.DragDropPayload
    if not ImGuiPayload_IsDataType(payload, IMGUI_PAYLOAD_TYPE_WINDOW) or not ImGui.DockNodeIsDropAllowed(window, payload.Data) then
        ImGui.EndDragDropTarget()
        return
    end

    local payload_window = payload.Data
    if ImGui.AcceptDragDropPayload(IMGUI_PAYLOAD_TYPE_WINDOW, bit32.bor(ImGuiDragDropFlags.AcceptBeforeDelivery, ImGuiDragDropFlags.AcceptNoDrawDefaultRect)) then
        -- Select target node
        -- (Important: we cannot use g.HoveredDockNode here! Because each of our target node have filters based on payload, each candidate drop target will do its own evaluation)
        local dock_into_floating_window = false
        local node = nil
        if window.DockNodeAsHost then
            -- Cannot assume that node will ~= nil even though we passed the rectangle test: it depends on padding/spacing handled by DockNodeTreeFindVisibleNodeByPos().
            node = ImGui.DockNodeTreeFindVisibleNodeByPos(window.DockNodeAsHost, g.IO.MousePos)

            -- There is an edge case when docking into a dockspace which only has _inactive_ nodes (because none of the windows are active)
            -- In this case we need to fallback into any leaf mode, possibly the central node.
            -- FIXME-20181220: We should not have to test for IsLeafNode() here but we have another bug to fix first.
            if node and node:IsDockSpace() and node:IsRootNode() then
                node = (node.CentralNode and node:IsLeafNode()) and node.CentralNode or ImGui.DockNodeTreeFindFallbackLeafNode(node)
            end
        else
            if window.DockNode then
                node = window.DockNode
            else
                dock_into_floating_window = true -- Dock into a regular window
            end
        end

        local explicit_target_rect
        if node and node.TabBar and not node:IsHiddenTabBar() and not node:IsNoTabBar() then
            explicit_target_rect = node.TabBar.BarRect
        else
            explicit_target_rect = ImRect(window.Pos, window.Pos + ImVec2(window.Size.x, ImGui.GetFrameHeight()))
        end
        local is_explicit_target = g.IO.ConfigDockingWithShift or ImGui.IsMouseHoveringRect(explicit_target_rect.Min, explicit_target_rect.Max)

        -- Preview docking request and find out split direction/ratio
        --local do_preview = true -- Ignore testing for payload:IsPreview() which removes one frame of delay, but breaks overlapping drop targets within the same window.
        local do_preview = ImGuiPayload_IsPreview(payload) or ImGuiPayload_IsDelivery(payload)
        if do_preview and (node ~= nil or dock_into_floating_window) then
            -- If we have a non-leaf node it means we are hovering the border of a parent node, in which case only outer markers will appear.
            local split_inner = ImGuiDockPreviewData()
            local split_outer = ImGuiDockPreviewData()
            local split_data = split_inner
            if node and (node.ParentNode or node:IsCentralNode() or not node:IsLeafNode()) then
                local root_node = ImGui.DockNodeGetRootNode(node)
                if root_node then
                    ImGui.DockNodePreviewDockSetup(window, root_node, payload_window, nil, split_outer, is_explicit_target, true)
                    if split_outer.IsSplitDirExplicit then split_data = split_outer end
                end
            end
            if not node or node:IsLeafNode() then
                ImGui.DockNodePreviewDockSetup(window, node, payload_window, nil, split_inner, is_explicit_target, false)
            end
            if split_data == split_outer then split_inner.IsDropAllowed = false end

            -- Draw inner then outer, so that previewed tab (in inner data) will be behind the outer drop boxes
            ImGui.DockNodePreviewDockRender(window, node, payload_window, split_inner)
            ImGui.DockNodePreviewDockRender(window, node, payload_window, split_outer)

            -- Queue docking request
            if split_data.IsDropAllowed and ImGuiPayload_IsDelivery(payload) then
                ImGui.DockContextQueueDock(g, window, split_data.SplitNode, payload_window, split_data.SplitDir, split_data.SplitRatio, split_data == split_outer)
            end
        end
    end
    ImGui.EndDragDropTarget()
end

-------------------------------------------------------------------------------
-- Docking: Settings
-------------------------------------------------------------------------------
-- - DockSettingsRenameNodeReferences()
-- - DockSettingsRemoveNodeReferences()
-- - DockSettingsFindNodeSettings()
-- - DockSettingsHandler_ApplyAll()
-- - DockSettingsHandler_ReadOpen()
-- - DockSettingsHandler_ReadLine()
-- - DockSettingsHandler_DockNodeToSettings()
-- - DockSettingsHandler_WriteAll()
-------------------------------------------------------------------------------

DockSettingsRenameNodeReferences = function(old_node_id, new_node_id)
    local g = ImGui.GetCurrentContext()
    for _, window in g.Windows:iter() do
        if window.DockId == old_node_id and window.DockNode == nil then window.DockId = new_node_id end
    end
    ---- FIXME-OPT: We could remove this loop by storing the index in the map
    for _, settings in g.SettingsWindows:iter() do
        if settings.DockId == old_node_id then settings.DockId = new_node_id end
    end
end

-- Remove references stored in ImGuiWindowSettings to the given ImGuiDockNodeSettings
--- @param node_ids table # 1-based array
DockSettingsRemoveNodeReferences = function(node_ids, node_ids_count)
    local g = ImGui.GetCurrentContext()
    local found = 0
    ---- FIXME-OPT: We could remove this loop by storing the index in the map
    for _, settings in g.SettingsWindows:iter() do
        for node_n = 1, node_ids_count do
            if settings.DockId == node_ids[node_n] then
                settings.DockId = 0
                settings.DockOrder = -1
                found = found + 1
                if found < node_ids_count then break end
                return
            end
        end
    end
end

DockSettingsFindNodeSettings = function(ctx, id)
    -- FIXME-OPT
    for _, s in ctx.DockContext.NodesSettings:iter() do
        if s.ID == id then return s end
    end
    return nil
end

-- Clear settings data
DockSettingsHandler_ClearAll = function(ctx, handler)
    local dc = ctx.DockContext
    dc.NodesSettings:clear()
    ImGui.DockContextClearNodes(ctx, 0, true)
end

-- Recreate nodes based on settings data
DockSettingsHandler_ApplyAll = function(ctx, handler)
    -- Prune settings at boot time only
    local dc = ctx.DockContext
    if ctx.Windows.Size == 0 then ImGui.DockContextPruneUnusedSettingsNodes(ctx) end
    ImGui.DockContextBuildNodesFromSettings(ctx, dc.NodesSettings.Data or {}, dc.NodesSettings.Size)
    ImGui.DockContextBuildAddWindowsToNodes(ctx, 0)
end

DockSettingsHandler_ReadOpen = function(ctx, handler, name)
    if name ~= "Data" then return nil end
    return true
end

DockSettingsHandler_ReadLine = function(ctx, handler, entry, line)
    -- Parsing, e.g.
    -- " DockNode   ID=0x00000001 Pos=383,193 Size=201,322 Split=Y,0.506 "
    -- "   DockNode ID=0x00000002 Parent=0x00000001 "
    -- Important: this code expect currently fields in a fixed order.
    local node = ImGuiDockNodeSettings()
    line = line:gsub("^[ \t]+", "")
    if line:sub(1, 8) == "DockNode" then
        line = line:sub(9)
    elseif line:sub(1, 9) == "DockSpace" then
        line = line:sub(10)
        node.Flags = bit32.bor(node.Flags, ImGuiDockNodeFlags.DockSpace)
    else
        return
    end
    line = line:gsub("^[ \t]+", "")
    local function take(pattern)
        local caps = { line:match("^" .. pattern .. "()") }
        if #caps == 0 then return nil end
        line = line:sub(caps[#caps])
        caps[#caps] = nil
        return table.unpack(caps)
    end
    local v = take("ID=0x(%x+)")
    if not v then return end
    node.ID = tonumber(v, 16)
    v = take(" Parent=0x(%x+)")
    if v then node.ParentNodeId = tonumber(v, 16); if node.ParentNodeId == 0 then return end end
    v = take(" Window=0x(%x+)")
    if v then node.ParentWindowId = tonumber(v, 16); if node.ParentWindowId == 0 then return end end
    if node.ParentNodeId == 0 then
        local x, y = take(" Pos=(%-?%d+),(%-?%d+)")
        if not x then return end
        node.Pos = ImVec2(tonumber(x), tonumber(y))
        x, y = take(" Size=(%-?%d+),(%-?%d+)")
        if not x then return end
        node.Size = ImVec2(tonumber(x), tonumber(y))
    else
        local x, y = take(" SizeRef=(%-?%d+),(%-?%d+)")
        if x then node.SizeRef = ImVec2(tonumber(x), tonumber(y)) end
    end
    local c = take(" Split=(%a)")
    if c then
        if c == "X" then node.SplitAxis = ImGuiAxis.X elseif c == "Y" then node.SplitAxis = ImGuiAxis.Y end
    end
    local function flag(name, f)
        local x = take(" " .. name .. "=(%-?%d+)")
        if x and tonumber(x) ~= 0 then node.Flags = bit32.bor(node.Flags, f) end
    end
    flag("NoResize", ImGuiDockNodeFlags.NoResize)
    flag("CentralNode", ImGuiDockNodeFlags.CentralNode)
    flag("NoTabBar", ImGuiDockNodeFlags.NoTabBar)
    flag("HiddenTabBar", ImGuiDockNodeFlags.HiddenTabBar)
    flag("NoWindowMenuButton", ImGuiDockNodeFlags.NoWindowMenuButton)
    flag("NoCloseButton", ImGuiDockNodeFlags.NoCloseButton)
    v = take(" Selected=0x(%x+)")
    if v then node.SelectedTabId = tonumber(v, 16) end
    if node.ParentNodeId ~= 0 then
        local parent_settings = DockSettingsFindNodeSettings(ctx, node.ParentNodeId)
        if parent_settings then node.Depth = parent_settings.Depth + 1 end
    end
    ctx.DockContext.NodesSettings:push_back(node)
end

local function DockSettingsHandler_DockNodeToSettings(dc, node, depth)
    local node_settings = ImGuiDockNodeSettings()
    node_settings.ID = node.ID
    node_settings.ParentNodeId = node.ParentNode and node.ParentNode.ID or 0
    node_settings.ParentWindowId = (node:IsDockSpace() and node.HostWindow and node.HostWindow.ParentWindow) and node.HostWindow.ParentWindow.ID or 0
    node_settings.SelectedTabId = node.SelectedTabId
    node_settings.SplitAxis = node:IsSplitNode() and node.SplitAxis or ImGuiAxis.None
    node_settings.Depth = depth
    node_settings.Flags = bit32.band(node.LocalFlags, ImGuiDockNodeFlags.SavedFlagsMask_)
    node_settings.Pos = ImVec2(ImTrunc(node.Pos.x), ImTrunc(node.Pos.y))
    node_settings.Size = ImVec2(ImTrunc(node.Size.x), ImTrunc(node.Size.y))
    node_settings.SizeRef = ImVec2(ImTrunc(node.SizeRef.x), ImTrunc(node.SizeRef.y))
    dc.NodesSettings:push_back(node_settings)
    if node.ChildNodes[0] then DockSettingsHandler_DockNodeToSettings(dc, node.ChildNodes[0], depth + 1) end
    if node.ChildNodes[1] then DockSettingsHandler_DockNodeToSettings(dc, node.ChildNodes[1], depth + 1) end
end

DockSettingsHandler_WriteAll = function(ctx, handler, buf)
    local g = ctx
    local dc = ctx.DockContext
    if bit32.band(g.IO.ConfigFlags, ImGuiConfigFlags.DockingEnable) == 0 then return end

    -- Gather settings data
    -- (unlike our windows settings, because nodes are always built we can do a full rewrite of the SettingsNode buffer)
    dc.NodesSettings:resize(0)
    for _, id in ipairs(DockContextNodesSorted(ctx)) do
        local node = dc.Nodes[id]
        if node and node:IsRootNode() then
            DockSettingsHandler_DockNodeToSettings(dc, node, 0)
        end
    end

    local max_depth = 0
    for _, s in dc.NodesSettings:iter() do max_depth = ImMax(s.Depth, max_depth) end

    -- Write to text buffer
    buf:appendf("[%s][Data]\n", handler.TypeName)
    for _, s in dc.NodesSettings:iter() do
        buf:append(string.rep(" ", s.Depth * 2) .. ((bit32.band(s.Flags, ImGuiDockNodeFlags.DockSpace) ~= 0) and "DockSpace" or "DockNode ") .. string.rep(" ", (max_depth - s.Depth) * 2)) -- Text align nodes to facilitate looking at .ini file
        buf:appendf(" ID=0x%08X", s.ID)
        if s.ParentNodeId ~= 0 then
            buf:appendf(" Parent=0x%08X SizeRef=%d,%d", s.ParentNodeId, s.SizeRef.x, s.SizeRef.y)
        else
            if s.ParentWindowId ~= 0 then buf:appendf(" Window=0x%08X", s.ParentWindowId) end
            buf:appendf(" Pos=%d,%d Size=%d,%d", s.Pos.x, s.Pos.y, s.Size.x, s.Size.y)
        end
        if s.SplitAxis ~= ImGuiAxis.None then buf:appendf(" Split=%s", (s.SplitAxis == ImGuiAxis.X) and "X" or "Y") end
        if bit32.band(s.Flags, ImGuiDockNodeFlags.NoResize) ~= 0 then buf:append(" NoResize=1") end
        if bit32.band(s.Flags, ImGuiDockNodeFlags.CentralNode) ~= 0 then buf:append(" CentralNode=1") end
        if bit32.band(s.Flags, ImGuiDockNodeFlags.NoTabBar) ~= 0 then buf:append(" NoTabBar=1") end
        if bit32.band(s.Flags, ImGuiDockNodeFlags.HiddenTabBar) ~= 0 then buf:append(" HiddenTabBar=1") end
        if bit32.band(s.Flags, ImGuiDockNodeFlags.NoWindowMenuButton) ~= 0 then buf:append(" NoWindowMenuButton=1") end
        if bit32.band(s.Flags, ImGuiDockNodeFlags.NoCloseButton) ~= 0 then buf:append(" NoCloseButton=1") end
        if s.SelectedTabId ~= 0 then buf:appendf(" Selected=0x%08X", s.SelectedTabId) end
        buf:append("\n")
    end
    buf:append("\n")
end

-------------------------------------------------------------------------------
-- Docking: helpers (imgui_internal.h inlines) + widgets used by docking
-------------------------------------------------------------------------------

function ImGui.DockNodeGetRootNode(node)
    while node.ParentNode do node = node.ParentNode end
    return node
end

function ImGui.DockNodeIsInHierarchyOf(node, parent)
    while node do
        if node == parent then return true end
        node = node.ParentNode
    end
    return false
end

function ImGui.DockNodeGetDepth(node)
    local depth = 0
    while node.ParentNode do node = node.ParentNode; depth = depth + 1 end
    return depth
end

function ImGui.DockNodeGetWindowMenuButtonId(node)
    return ImHashStr("#COLLAPSE", nil, node.ID)
end

function ImGui.GetWindowDockID()
    return ImGui.GetCurrentContext().CurrentWindow.DockId
end

function ImGui.IsWindowDocked()
    return ImGui.GetCurrentContext().CurrentWindow.DockIsActive
end

function ImGui.SetNextWindowDockID(id, cond)
    local g = ImGui.GetCurrentContext()
    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasDock)
    g.NextWindowData.DockCond = (cond and cond ~= 0) and cond or ImGuiCond.Always
    g.NextWindowData.DockId = id
end

-- We use 'undock == false' when dragging from title bar to allow moving groups of floating nodes without undocking them.
function ImGui.StartMouseMovingWindowOrNode(window, node, undock)
    local g = ImGui.GetCurrentContext()
    local can_undock_node = false
    if undock and node ~= nil and node.VisibleWindow and bit32.band(node.VisibleWindow.Flags, ImGuiWindowFlags.NoMove) == 0 and bit32.band(node.MergedFlags, ImGuiDockNodeFlags.NoUndocking) == 0 then
        -- Can undock if:
        -- - part of a hierarchy with more than one visible node (if only one is visible, we'll just move the root window)
        -- - part of a dockspace node hierarchy: so we can undock the last single visible node too. Undocking from a fixed/central node will create a new node and copy windows.
        local root_node = ImGui.DockNodeGetRootNode(node)
        if root_node.OnlyNodeWithWindows ~= node or root_node.CentralNode ~= nil then
            can_undock_node = true
        end
    end

    local clicked = ImGui.IsMouseClicked(0)
    local dragging = ImGui.IsMouseDragging(0)
    if can_undock_node and dragging then
        ImGui.DockContextQueueUndockNode(g, node) -- Will lead to DockNodeStartMouseMovingWindow() -> StartMouseMovingWindow() being called next frame
    elseif not can_undock_node and (clicked or dragging) and g.MovingWindow ~= window then
        ImGui.StartMouseMovingWindow(window)
    end
end

-- This is less wide than RenderArrow() and we use in dock nodes instead of the regular RenderArrow() to denote a change of functionality,
-- and because the saved space means that the left-most tab label can stay at exactly the same position as the label of a loose window.
function ImGui.RenderArrowDockMenu(draw_list, p_min, sz, col)
    draw_list:AddRectFilled(p_min + ImVec2(sz * 0.20, sz * 0.15), p_min + ImVec2(sz * 0.80, sz * 0.30), col)
    ImGui.RenderArrowPointingAt(draw_list, p_min + ImVec2(sz * 0.50, sz * 0.85), ImVec2(sz * 0.30, sz * 0.40), ImGuiDir.Down, col)
end

-- Upstream CollapseButton (docking branch): replaces the port's simpler version
-- The Collapse button also functions as a Dock Menu button.
function ImGui.CollapseButton(id, pos, dock_node)
    local g = ImGui.GetCurrentContext()
    local window = g.CurrentWindow

    local bb = ImRect(pos, pos + ImVec2(g.FontSize, g.FontSize))
    local is_clipped = not ImGui.ItemAdd(bb, id)
    local pressed, hovered, held = ImGui.ButtonBehavior(bb, id, ImGuiButtonFlags.None)
    if is_clipped then return pressed end

    -- Render
    --local is_dock_menu = (window.DockNodeAsHost and not window.Collapsed)
    local bg_col = ImGui.GetColorU32((held and hovered) and ImGuiCol.ButtonActive or (hovered and ImGuiCol.ButtonHovered or ImGuiCol.Button))
    local text_col = ImGui.GetColorU32(ImGuiCol.Text)
    if hovered or held then
        window.DrawList:AddRectFilled(bb.Min, bb.Max, bg_col)
    end
    ImGui.RenderNavCursor(bb, id, ImGuiNavRenderCursorFlags and ImGuiNavRenderCursorFlags.Compact or nil)

    if dock_node then
        ImGui.RenderArrowDockMenu(window.DrawList, bb.Min, g.FontSize, text_col)
    else
        ImGui.RenderArrow(window.DrawList, bb.Min, text_col, window.Collapsed and ImGuiDir.Right or ImGuiDir.Down, 1.0)
    end

    -- Switch to moving the window after mouse is moved beyond the initial drag threshold
    if ImGui.IsItemActive() and ImGui.IsMouseDragging(0) then
        ImGui.StartMouseMovingWindowOrNode(window, dock_node, true) -- Undock from window/collapse menu button
    end

    return pressed
end

-- Using 'hover_visibility_delay' allows us to hide the highlight and mouse cursor for a short time, which can be convenient to reduce visual noise.
--- @return bool held, float size1, float size2
function ImGui.SplitterBehavior(bb, id, axis, size1, size2, min_size1, min_size2, hover_extend, hover_visibility_delay, bg_col)
    hover_extend = hover_extend or 0.0
    hover_visibility_delay = hover_visibility_delay or 0.0
    bg_col = bg_col or 0
    local g = ImGui.GetCurrentContext()
    local window = g.CurrentWindow

    if not ImGui.ItemAdd(bb, id, nil, ImGuiItemFlags.NoNav) then return false, size1, size2 end

    -- FIXME: AFAIK the only leftover reason for passing ImGuiButtonFlags.AllowOverlap here is
    -- to allow caller of SplitterBehavior() to call SetItemAllowOverlap() after the item.
    -- Nowadays we would instead want to use SetNextItemAllowOverlap() before the item.
    local button_flags = bit32.bor(ImGuiButtonFlags.FlattenChildren, ImGuiButtonFlags.AllowOverlap)

    local bb_interact = ImRect(bb.Min, bb.Max)
    bb_interact:Expand(axis == ImGuiAxis.Y and ImVec2(0.0, hover_extend) or ImVec2(hover_extend, 0.0))
    local _, hovered, held = ImGui.ButtonBehavior(bb_interact, id, button_flags)
    if hovered then
        g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HoveredRect) -- for IsItemHovered(), because bb_interact is larger than bb
    end

    if held or (hovered and g.HoveredIdPreviousFrame == id and g.HoveredIdTimer >= hover_visibility_delay) then
        ImGui.SetMouseCursor(axis == ImGuiAxis.Y and ImGuiMouseCursor.ResizeNS or ImGuiMouseCursor.ResizeEW)
    end

    local bb_render = ImRect(bb.Min, bb.Max)
    if held then
        local d = g.IO.MousePos - g.ActiveIdClickOffset - bb_interact.Min
        local mouse_delta = d[axis]

        -- Minimum pane size
        local size_1_maximum_delta = ImMax(0.0, size1 - min_size1)
        local size_2_maximum_delta = ImMax(0.0, size2 - min_size2)
        if mouse_delta < -size_1_maximum_delta then mouse_delta = -size_1_maximum_delta end
        if mouse_delta > size_2_maximum_delta then mouse_delta = size_2_maximum_delta end

        -- Apply resize
        if mouse_delta ~= 0.0 then
            size1 = ImMax(size1 + mouse_delta, min_size1)
            size2 = ImMax(size2 - mouse_delta, min_size2)
            bb_render:Translate(axis == ImGuiAxis.X and ImVec2(mouse_delta, 0.0) or ImVec2(0.0, mouse_delta))
            ImGui.MarkItemEdited(id)
        end
    end

    -- Render at new position
    if bit32.band(bg_col, IM_COL32_A_MASK) ~= 0 then
        window.DrawList:AddRectFilled(bb_render.Min, bb_render.Max, bg_col, 0.0)
    end
    local col = ImGui.GetColorU32(held and ImGuiCol.SeparatorActive or ((hovered and g.HoveredIdTimer >= hover_visibility_delay) and ImGuiCol.SeparatorHovered or ImGuiCol.Separator))
    window.DrawList:AddRectFilled(bb_render.Min, bb_render.Max, col, 0.0)

    return held, size1, size2
end
end --[[ [SECTION] imgui_docking (was imgui_docking.lua) ]]

-- Debug options
local IMGUI_DEBUG_NAV_SCORING = false -- Display navigation scoring preview when hovering items. Hold Ctrl to display for all candidates. Ctrl+Arrow to change last direction.
local IMGUI_DEBUG_NAV_RECTS = false -- Display the reference navigation rectangle for each window

-- Default font size if unspecified in both style.FontSizeBase and AddFontXXX() calls.
local FONT_DEFAULT_SIZE_BASE = 20

local WINDOWS_RESIZE_FROM_EDGES_FEEDBACK_TIMER = 0.04 -- Reduce visual noise by only highlighting the border after a certain time.
local WINDOWS_MOUSE_WHEEL_SCROLL_LOCK_TIMER    = 0.70 -- Lock scrolled window (so it doesn't pick child windows that are scrolling through) for a certain time, unless mouse moved.

-- Tooltip offset
local TOOLTIP_DEFAULT_OFFSET_MOUSE = ImVec2(16, 10)   -- Multiplied by g.Style.MouseCursorScale
local TOOLTIP_DEFAULT_OFFSET_TOUCH = ImVec2(0, -20)   -- Multiplied by g.Style.MouseCursorScale
local TOOLTIP_DEFAULT_PIVOT_TOUCH  = ImVec2(0.5, 1.0) -- Multiplied by g.Style.MouseCursorScale

local IMGUI_VIEWPORT_DEFAULT_ID = 0x11111111 -- Using an arbitrary constant instead of e.g. ImHashStr("ViewportDefault", 0); so it's easier to spot in the debugger. The exact value doesn't matter.

local string = string
ImFormatString = string.format -- TODO: an simplified version that operates on byte tables directly?

--- @module "imstd_minstdio"
ImStd.sscanf = IM_INCLUDE"imstd_minstdio.lua"

local math = math
local bit32 = bit32

-------------------------------------------------------------------------------
-- [SECTION] MISC HELPERS/UTILITIES (File functions)
-------------------------------------------------------------------------------

--- This closes the _file.
--- @param _file any # File object
function IM_FILE_CLOSE(_file) end

--- This returns the size of _file in bytes.
--- @param _file any # File object
--- @return int
function IM_FILE_SIZE(_file) return -1 end

--- This writes _str into _file.
--- @param _file any    # File object
--- @param _str  string
function IM_FILE_WRITE(_file, _str) end

--- This reads the specified _count of chars and returns them as a binary string.
--- @param _file any  # File object
--- @param _count int
--- @return string
function IM_FILE_READ(_file, _count) return "" end

--- This opens the file at _filename in _mode and returns the File object.
--- @param _filename string
--- @param _mode     string # e.g. "rb"
--- @return any
function ImStd.ImFileOpen(_filename, _mode) end

--- [GMod] Platform specific
if gmod then
    IM_FILE_CLOSE = FindMetaTable("File").Close --- @type function
    IM_FILE_SIZE  = FindMetaTable("File").Size  --- @type function
    IM_FILE_WRITE = FindMetaTable("File").Write --- @type function
    IM_FILE_READ  = FindMetaTable("File").Read  --- @type function
end

-- Default file functions
if not IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS then
    --- [GMod] Another Platform specific
    if gmod then
        function ImStd.ImFileOpen(filename, mode) return file.Open(filename, mode, "GAME") end
    end

    function ImStd.ImFileClose(f) IM_FILE_CLOSE(f) end
    function ImStd.ImFileGetSize(f) return IM_FILE_SIZE(f) end

    --- @param f     any   # File object
    --- @param data  table # 1-based table to store result data
    --- @param count int   # Amount of bytes to read from `f`
    function ImStd.ImFileRead(f, data, count)
        local CHUNK_SIZE = 8000 -- We don't read byte by byte
        local offset = 0

        while offset < count do
            local read_size = math.min(CHUNK_SIZE, count - offset)
            local str = IM_FILE_READ(f, read_size)

            local bytes = {string.byte(str, 1, read_size)}
            for i = 1, read_size do
                data[offset + i] = bytes[i]
            end

            offset = offset + read_size
        end
    end

    -- Helper: Load file content into memory
    -- This can't really be used with "rt" because fseek size won't match read size.
    --- @param filename string
    --- @param mode     string
    --- @return table?, integer?
    function ImStd.ImFileLoadToMemory(filename, mode)
        local f = ImStd.ImFileOpen(filename, mode)
        if not f then return end

        local file_size = ImStd.ImFileGetSize(f)
        if file_size <= 0 then
            ImStd.ImFileClose(f)
            return
        end

        local file_data = {}
        ImStd.ImFileRead(f, file_data, file_size)
        if #file_data == 0 then
            ImStd.ImFileClose(f)
            return
        end

        ImStd.ImFileClose(f)

        return file_data, file_size
    end
end

--- Forward Declarations
local CalcNextScrollFromScrollTargetAndClamp

local MT = ImGui.GetMetatables()

-- Scale all spacing/padding/thickness values. Do not scale fonts.
-- Consider not calling this if your initial scale factor if <1.0.
-- Important: This operation is lossy because we round all sizes to integer. If you need to change your scale multiples, call this over a freshly initialized ImGuiStyle structure rather than scaling multiple times.
--- @param scale_factor float
function MT.ImGuiStyle:ScaleAllSizes(scale_factor)
    self._MainScale = self._MainScale * scale_factor

    self.WindowPadding    = ImTrunc(self.WindowPadding * scale_factor)
    self.WindowRounding   = ImTrunc(self.WindowRounding * scale_factor)
    self.WindowBorderSize = ImTrunc(self.WindowBorderSize * scale_factor)
    self.WindowMinSize    = ImTrunc(self.WindowMinSize * scale_factor)
    self.WindowBorderHoverPadding = ImTrunc(self.WindowBorderHoverPadding * scale_factor)
    self.ChildRounding     = ImTrunc(self.ChildRounding * scale_factor)
    self.ChildBorderSize   = ImTrunc(self.ChildBorderSize * scale_factor)
    self.PopupRounding     = ImTrunc(self.PopupRounding * scale_factor)
    self.PopupBorderSize   = ImTrunc(self.PopupBorderSize * scale_factor)
    self.FramePadding      = ImTrunc(self.FramePadding * scale_factor)
    self.FrameBorderSize   = ImTrunc(self.FrameBorderSize * scale_factor)
    self.FrameRounding     = ImTrunc(self.FrameRounding * scale_factor)
    self.ItemSpacing       = ImTrunc(self.ItemSpacing * scale_factor)
    self.ItemInnerSpacing  = ImTrunc(self.ItemInnerSpacing * scale_factor)
    self.CellPadding       = ImTrunc(self.CellPadding * scale_factor)
    self.TouchExtraPadding = ImTrunc(self.TouchExtraPadding * scale_factor)
    self.IndentSpacing     = ImTrunc(self.IndentSpacing * scale_factor)
    self.ColumnsMinSpacing = ImTrunc(self.ColumnsMinSpacing * scale_factor)
    self.ScrollbarSize     = ImTrunc(self.ScrollbarSize * scale_factor)
    self.ScrollbarRounding = ImTrunc(self.ScrollbarRounding * scale_factor)
    self.ScrollbarPadding  = ImTrunc(self.ScrollbarPadding * scale_factor)
    self.GrabMinSize       = ImTrunc(self.GrabMinSize * scale_factor)
    self.GrabRounding      = ImTrunc(self.GrabRounding * scale_factor)
    self.LogSliderDeadzone = ImTrunc(self.LogSliderDeadzone * scale_factor)
    self.ImageRounding     = ImTrunc(self.ImageRounding * scale_factor)
    self.ImageBorderSize   = ImTrunc(self.ImageBorderSize * scale_factor)
    self.TabRounding       = ImTrunc(self.TabRounding * scale_factor)
    self.TabBorderSize     = ImTrunc(self.TabBorderSize * scale_factor)
    self.TabMinWidthBase   = ImTrunc(self.TabMinWidthBase * scale_factor)
    self.TabMinWidthShrink = ImTrunc(self.TabMinWidthShrink * scale_factor)
    self.TabCloseButtonMinWidthSelected   = (self.TabCloseButtonMinWidthSelected > 0.0 and self.TabCloseButtonMinWidthSelected ~= FLT_MAX) and ImTrunc(self.TabCloseButtonMinWidthSelected * scale_factor) or self.TabCloseButtonMinWidthSelected
    self.TabCloseButtonMinWidthUnselected = (self.TabCloseButtonMinWidthUnselected > 0.0 and self.TabCloseButtonMinWidthUnselected ~= FLT_MAX) and ImTrunc(self.TabCloseButtonMinWidthUnselected * scale_factor) or self.TabCloseButtonMinWidthUnselected
    self.TabBarBorderSize         = ImTrunc(self.TabBarBorderSize * scale_factor)
    self.TabBarOverlineSize       = ImTrunc(self.TabBarOverlineSize * scale_factor)
    self.TreeLinesSize            = ImTrunc(self.TreeLinesSize * scale_factor)
    self.TreeLinesRounding        = ImTrunc(self.TreeLinesRounding * scale_factor)
    self.MenuItemRounding         = ImTrunc(self.MenuItemRounding * scale_factor)
    self.SelectableRounding       = ImTrunc(self.SelectableRounding * scale_factor)
    self.DragDropTargetRounding   = ImTrunc(self.DragDropTargetRounding * scale_factor)
    self.DragDropTargetBorderSize = ImTrunc(self.DragDropTargetBorderSize * scale_factor)
    self.DragDropTargetPadding    = ImTrunc(self.DragDropTargetPadding * scale_factor)
    self.ColorMarkerSize          = ImTrunc(self.ColorMarkerSize * scale_factor)
    self.InputTextCursorSize      = ImTrunc(self.InputTextCursorSize * scale_factor)
    self.SeparatorSize            = ImTrunc(self.SeparatorSize * scale_factor)
    self.SeparatorTextBorderSize  = ImTrunc(self.SeparatorTextBorderSize * scale_factor)
    self.SeparatorTextPadding     = ImTrunc(self.SeparatorTextPadding * scale_factor)
    self.DockingSeparatorSize     = ImTrunc(self.DockingSeparatorSize * scale_factor)
    self.DisplayWindowPadding     = ImTrunc(self.DisplayWindowPadding * scale_factor)
    self.DisplaySafeAreaPadding   = ImTrunc(self.DisplaySafeAreaPadding * scale_factor)
    self.MouseCursorScale         = ImTrunc(self.MouseCursorScale * scale_factor)
end

-- Data for resizing from resize grip / corner
local ImGuiResizeGripDef = {
    {CornerPosN = ImVec2(1, 1), InnerDir = ImVec2(-1, -1), AngleMin12 = 0, AngleMax12 = 3}, -- Lower-right
    {CornerPosN = ImVec2(0, 1), InnerDir = ImVec2( 1, -1), AngleMin12 = 3, AngleMax12 = 6}  -- Lower-left
}

-- Data for resizing from borders
-- InnerDir: Normal toward inside, SegmentN1/SegmentN2: End positions, normalized (0,0: upper left), OuterAngle: Angle toward outside
--- [1] Left, [2] Right, [3] Up, [4] Down
local ImGuiResizeBorderDef = {
    {InnerDir = ImVec2( 1,  0), SegmentN1 = ImVec2( 0,  1), SegmentN2 = ImVec2( 0,  0), OuterAngle = IM_PI * 1.00}, -- Left
    {InnerDir = ImVec2(-1,  0), SegmentN1 = ImVec2( 1,  0), SegmentN2 = ImVec2( 1,  1), OuterAngle = IM_PI * 0.00}, -- Right
    {InnerDir = ImVec2( 0,  1), SegmentN1 = ImVec2( 0,  0), SegmentN2 = ImVec2( 1,  0), OuterAngle = IM_PI * 1.50}, -- Up
    {InnerDir = ImVec2( 0, -1), SegmentN1 = ImVec2( 1,  1), SegmentN2 = ImVec2( 0,  1), OuterAngle = IM_PI * 0.50}  -- Down
}

--- @param window       ImGuiWindow
--- @param border_n     int
--- @param perp_padding float
--- @param thickness    float
--- @return ImRect
--- @nodiscard
local function GetResizeBorderRect(window, border_n, perp_padding, thickness)
    local rect = window:Rect()
    if thickness == 0.0 then
        ImVec2_CopyV(rect.Max, rect.Max.x - 1, rect.Max.y - 1)
    end
    if border_n == ImGuiDir.Left then
        return ImRect(rect.Min.x - thickness, rect.Min.y + perp_padding, rect.Min.x + thickness, rect.Max.y - perp_padding)
    end
    if border_n == ImGuiDir.Right then
        return ImRect(rect.Max.x - thickness, rect.Min.y + perp_padding, rect.Max.x + thickness, rect.Max.y - perp_padding)
    end
    if border_n == ImGuiDir.Up then
        return ImRect(rect.Min.x + perp_padding, rect.Min.y - thickness, rect.Max.x - perp_padding, rect.Min.y + thickness)
    end
    if border_n == ImGuiDir.Down then
        return ImRect(rect.Min.x + perp_padding, rect.Max.y - thickness, rect.Max.x - perp_padding, rect.Max.y + thickness)
    end
    IM_ASSERT(false)
    return ImRect()
end

-- Known size hash
-- It is ok to call ImHashData on a string with known length but the ### operator won't be supported.
--- @param data table|number
--- @param size int?         # size = -1 to indicate that `data` is a single number
--- @param seed int?
--- @return int
function ImHashData(data, size, seed)
    seed = seed or 0

    local FNV_OFFSET_BASIS = 0x811C9DC5
    local FNV_PRIME = 0x01000193

    local hash = bit32.bxor(FNV_OFFSET_BASIS, seed)

    if size == -1 then --- @cast data number
        hash = bit32.bxor(hash, data)
        hash = bit32.band(hash * FNV_PRIME, 0xFFFFFFFF)
    else
        size = size or #data
        for i = 1, size do
            hash = bit32.bxor(hash, data[i])
            hash = bit32.band(hash * FNV_PRIME, 0xFFFFFFFF)
        end
    end

    return hash
end

-- Zero-terminated string hash, with support for ### to reset back to seed value.
-- e.g. "label###id" outputs the same hash as "id" (and "label" is generally displayed by the UI functions)
-- Use FNV1a, as one ImGui FIXME suggested
--- @param str  string
--- @param size int?
--- @param seed int?
--- @return int
-- [Luau] memo for whole-string hashes: labels are re-hashed with the same seed every frame.
-- ponytail: whole-memo reset at HASH_MEMO_MAX entries, LRU if ID churn makes it thrash
local hash_memo, hash_memo_n, HASH_MEMO_MAX = {}, 0, 16384
local ImHashStrRaw

function ImHashStr(str, size, seed)
    if seed == nil then seed = 0 end
    if size == nil or size == #str then
        local m = hash_memo[seed]
        if m == nil then m = {}; hash_memo[seed] = m end
        local h = m[str]
        if h == nil then
            if hash_memo_n >= HASH_MEMO_MAX then hash_memo = { [seed] = m }; table.clear(m); hash_memo_n = 0 end
            h = ImHashStrRaw(str, #str, seed)
            m[str] = h
            hash_memo_n = hash_memo_n + 1
        end
        return h
    end
    return ImHashStrRaw(str, size, seed)
end


function ImHashStrRaw(str, size, seed)

    if str == "" or size == 0 then
        return seed -- need to match cpp code edge case behavior while using FNV ourselves
    end

    local FNV_OFFSET_BASIS = 0x811C9DC5
    local FNV_PRIME = 0x01000193

    local hash = bit32.bxor(FNV_OFFSET_BASIS, seed)

    local i = 1
    local c
    while i <= size do
        c = string.byte(str, i)

        -- `###` to reset back to initial hash value
        if c == 35 and string.byte(str, i + 1) == 35 and string.byte(str, i + 2) == 35 then
            hash = bit32.bxor(FNV_OFFSET_BASIS, seed)
            i = i + 2
        else
            hash = bit32.bxor(hash, c)
            hash = bit32.band(hash * FNV_PRIME, 0xFFFFFFFF)
        end

        i = i + 1
    end

    return hash
end

do --[[CharFromUtf8]]

local lengths = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 3, 3, 4, 0}
local masks   = {0x00, 0x7f, 0x1f, 0x0f, 0x07}
local mins    = {0x400000, 0, 0x80, 0x800, 0x10000}
local shiftc  = {0, 18, 12, 6, 0}
local shifte  = {0, 6, 4, 2, 0}

local s = {0, 0, 0, 0}

-- Convert UTF-8 to 32-bit character, process single character input.
-- A nearly-branchless UTF-8 decoder, based on work of Christopher Wellons (https://github.com/skeeto/branchless-utf8).
-- We handle UTF-8 decoding error by skipping forward.
--- @param in_text     ImString
--- @param pos         int
--- @param in_text_end int
--- @return int          wanted
--- @return unsigned_int out_char
function ImStd.ImTextCharFromUtf8(in_text, pos, in_text_end)
    local len = lengths[bit32.rshift(ImStrByte(in_text, pos), 3) + 1]
    local wanted = len > 0 and len or 1

    -- IMPORTANT: if in_text_end == nil it assume we have enough space!
    if in_text_end == nil then
        in_text_end = pos + wanted -- Max length, nulls will be taken into account.
    end

    -- Copy at most 'len' bytes, stop copying at 0 or past in_text_end. Branch predictor does a good job here,
    -- so it is fast even with excessive branching.
    s[1] = (pos     < in_text_end) and ImStrByte(in_text, pos)     or 0
    s[2] = (pos + 1 < in_text_end) and ImStrByte(in_text, pos + 1) or 0
    s[3] = (pos + 2 < in_text_end) and ImStrByte(in_text, pos + 2) or 0
    s[4] = (pos + 3 < in_text_end) and ImStrByte(in_text, pos + 3) or 0

    -- Assume a four-byte character and load four bytes. Unused bits are shifted out.
    local out_char
    out_char = bit32.lshift(bit32.band(s[1], masks[len + 1]), 18)
    out_char = bit32.bor(out_char, bit32.lshift(bit32.band(s[2], 0x3f), 12))
    out_char = bit32.bor(out_char, bit32.lshift(bit32.band(s[3], 0x3f),  6))
    out_char = bit32.bor(out_char, bit32.lshift(bit32.band(s[4], 0x3f),  0))
    out_char = bit32.rshift(out_char, shiftc[len + 1])

    -- Accumulate the various error conditions.
    local e = 0
    e = bit32.lshift((out_char < mins[len + 1]) and 1 or 0, 6) -- non-canonical encoding
    e = bit32.bor(e, bit32.lshift((bit32.rshift(out_char, 11) == 0x1b) and 1 or 0, 7)) -- surrogate half?
    e = bit32.bor(e, bit32.lshift((out_char > IM_UNICODE_CODEPOINT_MAX) and 1 or 0, 8)) -- out of range we can store in ImWchar (FIXME: May evolve)
    e = bit32.bor(e, bit32.rshift(bit32.band(s[2], 0xc0), 2))
    e = bit32.bor(e, bit32.rshift(bit32.band(s[3], 0xc0), 4))
    e = bit32.bor(e, bit32.rshift(s[4], 6))
    e = bit32.bxor(e, 0x2a) -- top two bits of each tail byte correct?
    e = bit32.rshift(e, shifte[len + 1])

    if e ~= 0 then
        -- No bytes are consumed when in_text[pos] == 0 || pos == in_text_end.
        -- One byte is consumed in case of invalid first byte of in_text.
        -- All available bytes (at most `len` bytes) are consumed on incomplete/invalid second to last bytes.
        -- Invalid or incomplete input may consume less bytes than wanted, therefore every byte has to be inspected in s.
        wanted = ImMin(wanted, (s[1] ~= 0 and 1 or 0) + (s[2] ~= 0 and 1 or 0) + (s[3] ~= 0 and 1 or 0) + (s[4] ~= 0 and 1 or 0))
        out_char = IM_UNICODE_CODEPOINT_INVALID
    end

    return wanted, out_char
end

end

-- Based on stb_to_utf8() from github.com/nothings/stb/
--- @param buf      char[]
--- @param buf_size int
--- @param c        unsigned_int
local function ImTextCharToUtf8_inline(buf, buf_size, c)
    if c < 0x80 then
        buf[1] = c
        return 1
    end
    if c < 0x800 then
        if buf_size < 2 then
            return 0
        end
        buf[1] = (0xc0 + bit32.rshift(c, 6))
        buf[2] = (0x80 + bit32.band(c, 0x3f))
        return 2
    end
    if c < 0x10000 then
        if buf_size < 3 then
            return 0
        end
        buf[1] = (0xe0 + bit32.rshift(c, 12))
        buf[2] = (0x80 + bit32.band(bit32.rshift(c, 6), 0x3f))
        buf[3] = (0x80 + bit32.band(c, 0x3f))
        return 3
    end
    if c <= 0x10FFFF then
        if buf_size < 4 then
            return 0
        end
        buf[1] = (0xf0 + bit32.rshift(c, 18))
        buf[2] = (0x80 + bit32.band(bit32.rshift(c, 12), 0x3f))
        buf[3] = (0x80 + bit32.band(bit32.rshift(c, 6), 0x3f))
        buf[4] = (0x80 + bit32.band(c, 0x3f))
        return 4
    end

    -- Invalid code point, the max unicode is 0x10FFFF
    return 0
end

--- @param out_buf [char, char, char, char, char]
--- @param c       unsigned_int
function ImStd.ImTextCharToUtf8(out_buf, c)
    local count = ImTextCharToUtf8_inline(out_buf, 5, c)
    out_buf[count + 1] = 0
    return count
end

-- Not optimal but we very rarely use this function.
--- @param in_text     ImString
--- @param pos         int
--- @param in_text_end int
--- @return int
function ImStd.ImTextCountUtf8BytesFromChar(in_text, pos, in_text_end)
    local bytes, unused = ImStd.ImTextCharFromUtf8(in_text, pos, in_text_end)
    return bytes
end

--- @param text          ImString
--- @param in_text_start int
--- @param in_p          int
function ImStd.ImTextFindPreviousUtf8Codepoint(text, in_text_start, in_p)
    while in_p > in_text_start do
        in_p = in_p - 1
        if bit32.band(ImStrByte(text, in_p), 0xC0) ~= 0x80 then
            return in_p
        end
    end
    return in_text_start
end

--- @param text          ImString
--- @param in_text_start int
--- @param in_text_end   int
--- @param in_p          int
--- @return int
function ImStd.ImTextFindValidUtf8CodepointEnd(text, in_text_start, in_text_end, in_p)
    if in_text_start == in_p then
        return in_text_start
    end

    local prev = ImStd.ImTextFindPreviousUtf8Codepoint(text, in_text_start, in_p)
    local prev_c_len, prev_c = ImStd.ImTextCharFromUtf8(text, prev, in_text_end)

    -- Check if the previous character is valid and fits within the range
    if prev_c ~= IM_UNICODE_CODEPOINT_INVALID and prev_c_len <= (in_p - prev) then
        return in_p
    end
    return prev
end

--- @param a ImVec2
--- @param b ImVec2
--- @param p ImVec2
--- @return ImVec2
--- @nodiscard
function ImStd.ImLineClosestPoint(a, b, p)
    local ap = p - a
    local ab_dir = b - a
    local dot = ap.x * ab_dir.x + ap.y * ab_dir.y
    if dot < 0.0 then
        return a
    end
    local ab_len_sqr = ab_dir.x * ab_dir.x + ab_dir.y * ab_dir.y
    if dot > ab_len_sqr then
        return b
    end
    return a + ab_dir * (dot / ab_len_sqr)
end

--- @param a ImVec2
--- @param b ImVec2
--- @param c ImVec2
--- @param p ImVec2
function ImStd.ImTriangleContainsPoint(a, b, c, p)
    local b1 = ((p.x - b.x) * (a.y - b.y) - (p.y - b.y) * (a.x - b.x)) < 0.0
    local b2 = ((p.x - c.x) * (b.y - c.y) - (p.y - c.y) * (b.x - c.x)) < 0.0
    local b3 = ((p.x - a.x) * (c.y - a.y) - (p.y - a.y) * (c.x - a.x)) < 0.0
    return (b1 == b2) and (b2 == b3)
end

--- @param a ImVec2
--- @param b ImVec2
--- @param c ImVec2
--- @param p ImVec2
--- @return float, float, float
function ImStd.ImTriangleBarycentricCoords(a, b, c, p)
    local v0 = b - a
    local v1 = c - a
    local v2 = p - a

    local denom = v0.x * v1.y - v1.x * v0.y
    local out_v = (v2.x * v1.y - v1.x * v2.y) / denom
    local out_w = (v0.x * v2.y - v2.x * v0.y) / denom
    local out_u = 1.0 - out_v - out_w

    return out_u, out_v, out_w
end

--- @param a ImVec2
--- @param b ImVec2
--- @param c ImVec2
--- @param p ImVec2
--- @return ImVec2
--- @nodiscard
function ImStd.ImTriangleClosestPoint(a, b, c, p)
    local proj_ab = ImStd.ImLineClosestPoint(a, b, p)
    local proj_bc = ImStd.ImLineClosestPoint(b, c, p)
    local proj_ca = ImStd.ImLineClosestPoint(c, a, p)

    local dist2_ab = ImLengthSqr(p - proj_ab)
    local dist2_bc = ImLengthSqr(p - proj_bc)
    local dist2_ca = ImLengthSqr(p - proj_ca)

    local m = ImMin(dist2_ab, ImMin(dist2_bc, dist2_ca))

    if m == dist2_ab then
        return proj_ab
    elseif m == dist2_bc then
        return proj_bc
    else
        return proj_ca
    end
end

--- @param dst     char[]
--- @param dst_pos int
--- @param src     char[]
--- @param src_pos int
--- @param count   size_t
function ImStd.ImStrncpy(dst, dst_pos, src, src_pos, count)
    if count < 1 then
        return
    end
    if count > 1 then
        ImStd.memmove(dst, dst_pos, src, src_pos, count - 1)
    end
    dst[dst_pos + (count - 1)] = 0
end

-- find beginning-of-line
--- @param str      char[]
--- @param mid_line int
--- @param begin    int
function ImStd.ImStrbol(str, mid_line, begin)
    IM_ASSERT_PARANOID(mid_line >= begin and mid_line <= #str)
    while mid_line > begin and str[mid_line - 1] ~= 10 do
        mid_line = mid_line - 1
    end
    return mid_line
end

-- Trim str by offsetting contents when there's leading data + writing a \0 at the trailing position. We use this in situation where the cost is negligible.
--- @param buf char[]
function ImStd.ImStrTrimBlanks(buf)
    local p = 1 -- buf_begin
    while buf[p] == 32 or buf[p] == 9 do -- Leading blanks
        p = p + 1
    end
    local p_start = p
    while buf[p] ~= 0 do -- Find end of string
        p = p + 1
    end
    while p > p_start and (buf[p - 1] == 32 or buf[p - 1] == 9) do -- Trailing blanks
        p = p - 1
    end
    if p_start > 1 then -- Copy memory if we had leading blanks
        ImStd.memmove(buf, 1, buf, p_start, p - p_start)
    end
    buf[p - p_start + 1] = 0 -- Zero terminate
end

-------------------------------------------------------------------------------
-- [SECTION] FONTS, TEXTURES
-------------------------------------------------------------------------------
-- Most of the relevant font logic is in imgui_draw.cpp.
-- Those are high-level support functions.
-------------------------------------------------------------------------------
-- - UpdateTexturesNewFrame() [Internal]
-- - UpdateTexturesEndFrame() [Internal]
-- - UpdateFontsNewFrame() [Internal]
-- - UpdateFontsEndFrame() [Internal]
-- - GetDefaultFont() [Internal]
-- - RegisterFontAtlas() [Internal]
-- - UnregisterFontAtlas() [Internal]
-- - SetCurrentFont() [Internal]
-- - UpdateCurrentFontSize() [Internal]
-- - PushFont()
-- - PopFont()
-------------------------------------------------------------------------------

function ImGui.UpdateCurrentFontSize(restore_font_size_after_scaling)
    local g = GImGui
    local window = g.CurrentWindow

    g.Style.FontSizeBase = g.FontSizeBase

    -- Early out to avoid hidden window keeping bakes referenced and out of GC reach.
    -- - However this leave a pretty subtle and damning error surface area if g.FontBaked was mismatching.
    --   Probably needs to be reevaluated into e.g. setting g.FontBaked = nil to mark it as dirty.
    -- - Note that 'PushFont(); Begin(); End(); PopFont()' from within any collapsed window is not compromised, because Begin() calls SetCurrentWindow()->...->UpdateCurrentSize()
    -- if (window ~= nil and window.SkipItems) then
    --     local table = g.CurrentTable
    --     if (table == nil or (table.CurrentColumn ~= -1 and table.Columns[table.CurrentColumn].IsSkipItems == false)) then
    --         return
    --     end
    -- end

    -- Restoring is pretty much only used by PopFont()
    local final_size = (restore_font_size_after_scaling > 0.0) and restore_font_size_after_scaling or 0.0
    if final_size == 0.0 then
        final_size = g.FontSizeBase

        -- Global scale factors
        final_size = final_size * g.Style.FontScaleMain -- Main global scale factor
        final_size = final_size * g.Style.FontScaleDpi -- Per-monitor/viewport DPI scale factor (in docking branch: automatically updated when io.ConfigDpiScaleFonts is enabled).

        -- Window scale (mostly obsolete now)
        if window ~= nil then
            final_size = final_size * window.FontWindowScale
        end
    end

    -- Round font size
    -- - We started rounding in 1.90 WIP (18991) as our layout system currently doesn't support non-rounded font size well yet.
    -- - We may support it better later and remove this rounding.
    final_size = ImGui.GetRoundedFontSize(final_size)
    final_size = ImClamp(final_size, 4.0, IMGUI_FONT_SIZE_MAX)
    if (g.Font ~= nil and bit32.band(g.IO.BackendFlags, ImGuiBackendFlags.RendererHasTextures) ~= 0) then
        g.Font.CurrentRasterizerDensity = g.FontRasterizerDensity
    end
    g.FontSize = final_size
    g.FontBaked = (g.Font ~= nil and window ~= nil) and g.Font:GetFontBaked(final_size) or nil
    g.FontBakedScale = (g.FontBaked ~= nil) and (g.FontSize / g.FontBaked.Size) or 0.0
    g.DrawListSharedData.FontSize = g.FontSize
    g.DrawListSharedData.FontScale = g.FontBakedScale
end

-- Use ImDrawList:_SetTexture(), making our shared g.FontStack[] authoritative against window-local ImDrawList.
-- - Whereas ImDrawList:PushTexture()/PopTexture() is not to be used across Begin() calls.
-- - Note that we don't propagate current texture id when e.g. Begin()-ing into a new window, we never really did...
--   - Some code paths never really fully worked with multiple atlas textures.
--   - The right-ish solution may be to remove _SetTexture() and make AddText/RenderText lazily call PushTexture()/PopTexture()
--     the same way AddImage() does, but then all other primitives would also need to? I don't think we should tackle this problem
--     because we have a concrete need and a test bed for multiple atlas textures.
-- FIXME-NEWATLAS-V2: perhaps we can now leverage ImFontAtlasUpdateDrawListsTextures() ?
function ImGui.SetCurrentFont(font, font_size_before_scaling, font_size_after_scaling)
    local g = GImGui

    g.Font = font
    g.FontSizeBase = font_size_before_scaling
    ImGui.UpdateCurrentFontSize(font_size_after_scaling)

    if font ~= nil then
        IM_ASSERT(font and font:IsLoaded()) -- Font Atlas not created. Did you call io.Fonts:GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?
        local atlas = font.OwnerAtlas
        g.DrawListSharedData.FontAtlas = atlas
        g.DrawListSharedData.Font = font
        ImFontAtlasUpdateDrawListsSharedData(atlas)
        if (g.CurrentWindow ~= nil) then
            g.CurrentWindow.DrawList:_SetTexture(atlas.TexRef)
        end
    end
end

-- If you want to scale an existing font size! Read comments in imgui.h!
function ImGui.PushFont(font, font_size_base)
    local g = GImGui

    if font == nil then -- Before 1.92 (June 2025), PushFont(nil) == PushFont(GetDefaultFont())
        font = g.Font
    end

    IM_ASSERT(font ~= nil)
    IM_ASSERT(font_size_base >= 0.0)

    g.FontStack:push_back(ImFontStackData(font, g.FontSizeBase, g.FontSize))

    if font_size_base == 0.0 then
        font_size_base = g.FontSizeBase -- Keep current font size
    end

    ImGui.SetCurrentFont(font, font_size_base, 0.0)
end

function ImGui.PopFont()
    local g = GImGui

    if (g.FontStack.Size <= 0) then
        IM_ASSERT_USER_ERROR(0, "Calling PopFont() too many times!")

        return
    end

    local font_stack_data = g.FontStack:back()
    ImGui.SetCurrentFont(font_stack_data.Font, font_stack_data.FontSizeBeforeScaling, font_stack_data.FontSizeAfterScaling)

    g.FontStack:pop_back()
end

function ImGui.UpdateTexturesNewFrame()
    -- Cannot update every atlases based on atlas's FrameCount < g.FrameCount, because an atlas may be shared by multiple contexts with different frame count.
    local g = GImGui
    local has_textures = bit32.band(g.IO.BackendFlags, ImGuiBackendFlags.RendererHasTextures) ~= 0
    for _, atlas in g.FontAtlases:iter() do
        if (atlas.OwnerContext == g) then
            ImFontAtlasUpdateNewFrame(atlas, g.FrameCount, has_textures)
        else
            -- (1) If you manage font atlases yourself, e.g. create a ImFontAtlas yourself you need to call ImFontAtlasUpdateNewFrame() on it.
            -- Otherwise, calling ImGui.CreateContext() without parameter will create an atlas owned by the context.
            -- (2) If you have multiple font atlases, make sure the 'atlas.RendererHasTextures' as specified in the ImFontAtlasUpdateNewFrame() call matches for that.
            -- (3) If you have multiple imgui contexts, they also need to have a matching value for ImGuiBackendFlags.RendererHasTextures.
            IM_ASSERT(atlas.Builder ~= nil and atlas.Builder.FrameCount ~= -1)
            IM_ASSERT(atlas.RendererHasTextures == has_textures)
        end
    end

    for _, tex in g.UserTextures:iter() do
        ImTextureDataUpdateNewFrame(tex)
    end
end

-- Build a single texture list
function ImGui.UpdateTexturesEndFrame()
    local g = GImGui
    g.PlatformIO.Textures:resize(0)
    for _, atlas in g.FontAtlases:iter() do
        for _, tex in atlas.TexList:iter() do
            -- We provide this information so backends can decide whether to destroy textures.
            -- This means in practice that if N imgui contexts are created with a shared atlas, we assume all of them have a backend initialized.
            tex.RefCount = atlas.RefCount
            g.PlatformIO.Textures:push_back(tex)
        end
    end
    for _, tex in g.UserTextures:iter() do
        g.PlatformIO.Textures:push_back(tex)
    end
end

function ImGui.UpdateFontsNewFrame()
    local g = GImGui
    if (bit32.band(g.IO.BackendFlags, ImGuiBackendFlags.RendererHasTextures) == 0) then
        for _, atlas in g.FontAtlases:iter() do
            atlas.Locked = true
        end
    end

    if (g.Style._NextFrameFontSizeBase ~= 0.0) then
        g.Style.FontSizeBase = g.Style._NextFrameFontSizeBase
        g.Style._NextFrameFontSizeBase = 0.0
    end

    -- Apply default font size the first time
    local font = ImGui.GetDefaultFont()
    if g.Style.FontSizeBase <= 0.0 then
        g.Style.FontSizeBase = ((font.LegacySize > 0.0) and font.LegacySize or FONT_DEFAULT_SIZE_BASE)
    end

    -- Set initial font
    g.Font = font
    g.FontSizeBase = g.Style.FontSizeBase
    g.FontSize = 0.0
    local font_stack_data = ImFontStackData(font, g.Style.FontSizeBase, g.Style.FontSizeBase) -- <--- Will restore FontSize
    ImGui.SetCurrentFont(font_stack_data.Font, font_stack_data.FontSizeBeforeScaling, 0.0) -- <--- but use 0.0f to enable scale
    g.FontStack:push_back(font_stack_data)
    IM_ASSERT(g.Font:IsLoaded())
end

function ImGui.UpdateFontsEndFrame()
    ImGui.PopFont()
end

--- @return ImFont
function ImGui.GetDefaultFont()
    local g = GImGui
    local atlas = g.IO.Fonts
    if (atlas.Builder == nil or atlas.Fonts.Size == 0) then
        ImFontAtlasBuildMain(atlas)
    end
    return g.IO.FontDefault and g.IO.FontDefault or atlas.Fonts[1]
end

--- @param atlas ImFontAtlas
function ImGui.RegisterFontAtlas(atlas)
    local g = GImGui
    if (g.FontAtlases.Size == 0) then
        IM_ASSERT(atlas == g.IO.Fonts)
    end
    atlas.RefCount = atlas.RefCount + 1
    g.FontAtlases:push_back(atlas)
    ImFontAtlasAddDrawListSharedData(atlas, g.DrawListSharedData)
    for _, tex in atlas.TexList:iter() do
        tex.RefCount = atlas.RefCount
    end
end

--- @param atlas ImFontAtlas
function ImGui.UnregisterFontAtlas(atlas)
    local g = GImGui
    IM_ASSERT(atlas.RefCount > 0)
    ImFontAtlasRemoveDrawListSharedData(atlas, g.DrawListSharedData)
    g.FontAtlases:find_erase(atlas)
    atlas.RefCount = atlas.RefCount - 1
    for _, tex in atlas.TexList:iter() do
        tex.RefCount = atlas.RefCount
    end
end

-------------------------------------------------------------------------------
-- [SECTION] INITIALIZATION, SHUTDOWN
-------------------------------------------------------------------------------

-- Internal state access - if you want to share Dear ImGui state between modules (e.g. DLL) or allocate it yourself
function ImGui.GetCurrentContext()
    return GImGui
end

--- @param ctx ImGuiContext?
function ImGui.SetCurrentContext(ctx)
    GImGui = ctx

    ImGui._SetCurrentContext_Internal(ctx)
    ImGui._SetCurrentContext_Widgets(ctx)
    ImGui._SetCurrentContext_Tables(ctx)
end

--- @param alloc_func ImGuiMemAllocFunc
--- @param free_func  ImGuiMemFreeFunc
--- @param user_data  any
function ImGui.SetAllocatorFunctions(alloc_func, free_func, user_data)
    GImAllocatorAllocFunc = alloc_func
    GImAllocatorFreeFunc = free_func
    GImAllocatorUserData = user_data
end

--- @param key  ImGuiLocKey
--- @param text string
--- @return ImGuiLocEntry
--- @nodiscard
--- @package
local function ImGuiLocEntry(key, text)
    return { Key = key, Text = text }
end

-- IMPORTANT: interactive elements requires a fixed ###xxx suffix, it must be same in ALL languages to allow for automation.
local GLocalizationEntriesEnUS = {
    ImGuiLocEntry(ImGuiLocKey.VersionStr,                    "Dear ImGui WIP"),
    ImGuiLocEntry(ImGuiLocKey.TableSizeOne,                  "Size column to fit###SizeOne"),
    ImGuiLocEntry(ImGuiLocKey.TableSizeAllFit,               "Size all columns to fit###SizeAll"),
    ImGuiLocEntry(ImGuiLocKey.TableSizeAllDefault,           "Size all columns to default###SizeAll"),
    ImGuiLocEntry(ImGuiLocKey.TableReset,                    "Reset"),
  --ImGuiLocEntry(ImGuiLocKey.TableResetAll,                 "Reset to default###ResetAll"),
    ImGuiLocEntry(ImGuiLocKey.TableResetOrder,               "Reset order###ResetOrder"),
    ImGuiLocEntry(ImGuiLocKey.TableResetVisibility,          "Reset visibility###ResetVisibility"),
    ImGuiLocEntry(ImGuiLocKey.WindowingMainMenuBar,          "(Main menu bar)"),
    ImGuiLocEntry(ImGuiLocKey.WindowingPopup,                "(Popup)"),
    ImGuiLocEntry(ImGuiLocKey.WindowingUntitled,             "(Untitled)"),
    ImGuiLocEntry(ImGuiLocKey.OpenLink_s,                    "Open '%s'"),
    ImGuiLocEntry(ImGuiLocKey.CopyLink,                      "Copy Link###CopyLink"),
    ImGuiLocEntry(ImGuiLocKey.DockingHideTabBar,             "Hide tab bar###HideTabBar"),
    ImGuiLocEntry(ImGuiLocKey.DockingHoldShiftToDock,        "Hold SHIFT to enable Docking window."),
    ImGuiLocEntry(ImGuiLocKey.DockingDragToUndockOrMoveNode, "Click and drag to move or undock whole node."),
}

function ImGui.Initialize()
    local g = GImGui
    IM_ASSERT(not g.Initialized and not g.SettingsLoaded)

    -- Add .ini handle for ImGuiWindow and ImGuiTable types
    ImGui.WindowSettingsAddSettingsHandler()
    if ImGui.TableSettingsAddSettingsHandler then ImGui.TableSettingsAddSettingsHandler() end
    -- Initialize Docking
    ImGui.DockContextInitialize(g)
    -- Setup default localization table
    ImGui.LocalizeRegisterEntries(GLocalizationEntriesEnUS, #GLocalizationEntriesEnUS)

    -- Create default viewport
    local viewport = ImGuiViewportP()
    viewport.ID = IMGUI_VIEWPORT_DEFAULT_ID
    viewport.Idx = 1
    viewport.PlatformWindowCreated = true
    viewport.Flags = ImGuiViewportFlags.OwnedByApp
    g.Viewports:push_back(viewport)
    g.ViewportCreatedCount = g.ViewportCreatedCount + 1
    g.PlatformIO.Viewports:push_back(g.Viewports.Data[1])

    -- Build KeysMayBeCharInput[] lookup table (1 bit per named key)
    for key = ImGuiKey.NamedKey_BEGIN, ImGuiKey.NamedKey_END - 1 do
        if (key >= ImGuiKey.K0 and key <= ImGuiKey.K9) or (key >= ImGuiKey.A and key <= ImGuiKey.Z) or (key >= ImGuiKey.Keypad0 and key <= ImGuiKey.Keypad9)
            or key == ImGuiKey.Tab or key == ImGuiKey.Space or key == ImGuiKey.Apostrophe or key == ImGuiKey.Comma or key == ImGuiKey.Minus or key == ImGuiKey.Period
            or key == ImGuiKey.Slash or key == ImGuiKey.Semicolon or key == ImGuiKey.Equal or key == ImGuiKey.LeftBracket or key == ImGuiKey.RightBracket or key == ImGuiKey.GraveAccent
            or key == ImGuiKey.KeypadDecimal or key == ImGuiKey.KeypadDivide or key == ImGuiKey.KeypadMultiply or key == ImGuiKey.KeypadSubtract or key == ImGuiKey.KeypadAdd or key == ImGuiKey.KeypadEqual then
            g.KeysMayBeCharInput:SetBit(key + 1)
        end
    end

    -- ImDrawList/ImFontAtlas are designed to function without ImGui, and 99% of it works without an ImGui context.
    -- But this link allows us to facilitate/handle a few edge cases better.
    local atlas = g.IO.Fonts
    g.DrawListSharedData.Context = g
    ImGui.RegisterFontAtlas(atlas)

    g.Initialized = true
end

--- @param shared_font_atlas? ImFontAtlas
function ImGui.CreateContext(shared_font_atlas)
    local prev_ctx = ImGui.GetCurrentContext()
    local ctx = ImGuiContext(shared_font_atlas)
    ImGui.SetCurrentContext(ctx)
    ImGui.Initialize()
    if prev_ctx ~= nil then
        ImGui.SetCurrentContext(prev_ctx) -- Restore previous context if any, else keep new one
    end
    return ctx
end

--- @param ctx? ImGuiContext
function ImGui.DestroyContext(ctx)
    local prev_ctx = ImGui.GetCurrentContext()
    if ctx == nil then
        ctx = prev_ctx
    end
    ImGui.SetCurrentContext(ctx)
    ImGui.Shutdown()
    ImGui.SetCurrentContext((prev_ctx ~= ctx) and prev_ctx or nil)
end

-- This is faster if you are holding on a Window already as we don't need to perform a search.
--- @param window ImGuiWindow
--- @return any
function ImGui.FindWindowSettingsByWindow(window)
    local g = GImGui
    if window.SettingsOffset ~= -1 then
        return g.SettingsWindows[window.SettingsOffset + 1]
    end
    return ImGui.FindWindowSettingsByID(window.ID)
end

-- We don't provide a FindWindowSettingsByName() because Docking system doesn't always hold on names.
-- This is called once per window .ini entry + once per newly instantiated window.
--- @param id ImGuiID
--- @return any
function ImGui.FindWindowSettingsByID(id)
    local g = GImGui
    for _, settings in g.SettingsWindows:iter() do
        if settings.ID == id and not settings.WantDelete then
            return settings
        end
    end
    return nil
end

--- @param window ImGuiWindow
--- @return ImGuiWindow?
function ImGui.FindFrontMostVisibleChildWindow(window)
    for n = window.DC.ChildWindows.Size, 1, -1 do
        if ImGui.IsWindowActiveAndVisible(window.DC.ChildWindows.Data[n]) then
            return ImGui.FindFrontMostVisibleChildWindow(window.DC.ChildWindows.Data[n])
        end
    end
    return window
end

--- @param window ImGuiWindow
--- @param cond ImGuiCond
--- @param allow bool
local function SetWindowConditionAllowFlags(window, cond, allow)
    if allow then
        window.SetWindowPosAllowFlags = bit32.bor(window.SetWindowPosAllowFlags, cond)
        window.SetWindowSizeAllowFlags = bit32.bor(window.SetWindowSizeAllowFlags, cond)
        window.SetWindowCollapsedAllowFlags = bit32.bor(window.SetWindowCollapsedAllowFlags, cond)
    else
        window.SetWindowPosAllowFlags = bit32.band(window.SetWindowPosAllowFlags, bit32.bnot(cond))
        window.SetWindowSizeAllowFlags = bit32.band(window.SetWindowSizeAllowFlags, bit32.bnot(cond))
        window.SetWindowCollapsedAllowFlags = bit32.band(window.SetWindowCollapsedAllowFlags, bit32.bnot(cond))
    end
end

--- @param window ImGuiWindow
--- @param settings ImGuiWindowSettings
local function ApplyWindowSettings(window, settings)
    if settings ~= nil then
        local main_viewport = ImGui.GetMainViewport()
        ImVec2_Copy(window.ViewportPos, main_viewport.Pos)
        if (settings.ViewportId ~= 0) then
            window.ViewportId = settings.ViewportId
            ImVec2_Copy(window.ViewportPos, settings.ViewportPos)
        end
        window.Pos = ImTrunc(ImVec2(settings.Pos.x + window.ViewportPos.x, settings.Pos.y + window.ViewportPos.y))
        if settings.Size.x > 0 and settings.Size.y > 0 then
            local size = ImVec2(ImTrunc(settings.Size.x), ImTrunc(settings.Size.y))
            ImVec2_Copy(window.Size, size)
            ImVec2_Copy(window.SizeFull, size)
            window.AutoFitFramesX = 0; window.AutoFitFramesY = 0
        end
        window.Collapsed = settings.Collapsed
        window.DockId = settings.DockId or 0
        window.DockOrder = settings.DockOrder or -1
        SetWindowConditionAllowFlags(window, ImGuiCond.FirstUseEver, false)
    end

    -- So first call to CalcWindowContentSizes() doesn't return crazy values
    ImVec2_Copy(window.DC.CursorStartPos, window.Pos)
    ImVec2_Copy(window.DC.CursorMaxPos, window.Pos)
    ImVec2_Copy(window.DC.IdealMaxPos, window.Pos)
    if (bit32.band(window.Flags, ImGuiWindowFlags.AlwaysAutoResize) ~= 0) then
        window.AutoFitFramesX = 2; window.AutoFitFramesY = 2
        window.AutoFitOnlyGrows = false
    else
        window.AutoFitFramesX = (window.Size.x <= 0.0) and 2 or 0
        window.AutoFitFramesY = (window.Size.y <= 0.0) and 2 or 0
        window.AutoFitOnlyGrows = (window.AutoFitFramesX > 0) or (window.AutoFitFramesY > 0)
    end
end

-- Note that 'settings' may be nil.
-- Sets _Once, _Appearing, _FirstUseEver. _FirstUseEver will be cleared again if there are settings.
--- @param window ImGuiWindow
--- @param settings ImGuiWindowSettings
local function InitOrLoadWindowSettings(window, settings)
    -- Initial window state with e.g. default/arbitrary window position
    -- Use SetNextWindowPos() with the appropriate condition flag to change the initial position of a window.
    local main_viewport = ImGui.GetMainViewport()
    ImVec2_Copy(window.Pos, main_viewport.Pos + ImVec2(60, 60))
    ImVec2_Copy(window.Size, ImVec2(0, 0))
    ImVec2_Copy(window.SizeFull, ImVec2(0, 0))
    ImVec2_Copy(window.ViewportPos, main_viewport.Pos)
    window.SetWindowPosAllowFlags = bit32.bor(ImGuiCond.Always, ImGuiCond.Once, ImGuiCond.FirstUseEver, ImGuiCond.Appearing)
    window.SetWindowSizeAllowFlags = window.SetWindowPosAllowFlags
    window.SetWindowCollapsedAllowFlags = window.SetWindowPosAllowFlags
    window.SetWindowDockAllowFlags = window.SetWindowPosAllowFlags
    ApplyWindowSettings(window, settings)
    if settings ~= nil then
        -- TODO: settings.LastUsedDate = g.SessionDate
    end
end

--- @param name string
--- @param flags ImGuiWindowFlags
--- @return ImGuiWindow
local function CreateNewWindow(name, flags)
    -- Create window the first time
    --IMGUI_DEBUG_LOG("CreateNewWindow '%s', flags = 0x%08X\n", name, flags)
    local g = GImGui

    local window_id = ImHashStr(name)

    local window = ImGuiWindow(g, name)

    window.ID = window_id
    window.Flags = flags

    g.WindowsById[window_id] = window

    local settings = nil
    if bit32.band(window.Flags, ImGuiWindowFlags.NoSavedSettings) == 0 then
        settings = ImGui.FindWindowSettingsByWindow(window)
        if settings ~= nil then
            window.SettingsOffset = g.SettingsWindows:index_from_ptr(settings)
        end
    end

    InitOrLoadWindowSettings(window, settings)

    if bit32.band(flags, ImGuiWindowFlags.NoBringToFrontOnFocus) ~= 0 then
        g.Windows:push_front(window) -- Quite slow but rare and only once
    else
        g.Windows:push_back(window)
    end

    return window
end


-------------------------------------------------------------------------------
-- [SECTION] SETTINGS
-- (in-memory .ini; Roblox has no disk)
-------------------------------------------------------------------------------
-- - UpdateSettings() [Internal]
-- - MarkIniSettingsDirty() [Internal]
-- - FindSettingsHandler() [Internal]
-- - ClearIniSettings() [Internal]
-- - LoadIniSettingsFromDisk()
-- - LoadIniSettingsFromMemory()
-- - SaveIniSettingsToDisk()
-- - SaveIniSettingsToMemory()
-------------------------------------------------------------------------------
-- - CreateNewWindowSettings() [Internal]
-- - FindWindowSettingsByID() [Internal]
-- - FindWindowSettingsByWindow() [Internal]
-- - ClearWindowSettings() [Internal]
-- - WindowSettingsHandler_***() [Internal]
-------------------------------------------------------------------------------

-- Called by NewFrame()
function ImGui.UpdateSettings()
    -- Load settings on first frame (if not explicitly loaded manually before)
    local g = GImGui
    if not g.SettingsLoaded then
        if g.IO.IniFilename then ImGui.LoadIniSettingsFromDisk(g.IO.IniFilename) end
        g.SettingsLoaded = true
    end

    -- Save settings (with a delay after the last modification, so we don't spam disk too much)
    if g.SettingsDirtyTimer > 0.0 then
        g.SettingsDirtyTimer = g.SettingsDirtyTimer - g.IO.DeltaTime
        if g.SettingsDirtyTimer <= 0.0 then
            -- No disk: always let the user know they can call SaveIniSettingsToMemory()
            g.IO.WantSaveIniSettings = true -- Let user know they can call SaveIniSettingsToMemory(). user will need to clear io.WantSaveIniSettings themselves.
            g.SettingsDirtyTimer = 0.0
        end
    end
end

--- @param window? ImGuiWindow
function ImGui.MarkIniSettingsDirty(window)
    local g = GImGui
    if window ~= nil and bit32.band(window.Flags, ImGuiWindowFlags.NoSavedSettings) ~= 0 then return end
    if g.SettingsDirtyTimer <= 0.0 then
        g.SettingsDirtyTimer = g.IO.IniSavingRate
    end
end

--- @param handler ImGuiSettingsHandler
function ImGui.AddSettingsHandler(handler)
    local g = GImGui
    IM_ASSERT(ImGui.FindSettingsHandler(handler.TypeName) == nil)
    if handler.TypeHash == 0 or handler.TypeHash == nil then handler.TypeHash = ImHashStr(handler.TypeName) end
    g.SettingsHandlers:push_back(handler)
end

function ImGui.RemoveSettingsHandler(type_name)
    local g = GImGui
    local handler = ImGui.FindSettingsHandler(type_name)
    if handler then g.SettingsHandlers:find_erase(handler) end
end

function ImGui.FindSettingsHandler(type_name)
    local g = GImGui
    local type_hash = ImHashStr(type_name)
    for _, handler in g.SettingsHandlers:iter() do
        if handler.TypeHash == type_hash then return handler end
    end
    return nil
end

-- Clear all settings (windows, tables, docking etc.)
function ImGui.ClearIniSettings()
    local g = GImGui
    g.SettingsIniData = ""
    for _, handler in g.SettingsHandlers:iter() do
        if handler.ClearAllFn then handler.ClearAllFn(g, handler) end
    end
end

function ImGui.CleanupIniSettings(args)
    local g = GImGui
    if args.DiscardAll then
        for _, handler in g.SettingsHandlers:iter() do
            if (args.TypeHashFilter or 0) == 0 or handler.TypeHash == args.TypeHashFilter then
                if handler.ClearAllFn then handler.ClearAllFn(g, handler) end
            end
        end
    end
end

function ImGui.LoadIniSettingsFromDisk(ini_filename)
    local data = ImStd.ImFileLoadToMemory and ImStd.ImFileLoadToMemory(ini_filename, "rb")
    if not data or #data == 0 then return end
    local parts = {}
    for i = 1, #data do parts[i] = string.char(data[i]) end
    ImGui.LoadIniSettingsFromMemory(table.concat(parts))
end

-- Zero-tolerance, no error reporting, cheap .ini parsing
-- Set ini_size==0 (or nil) to use the whole string (Lua strings know their length).
function ImGui.LoadIniSettingsFromMemory(ini_data, ini_size)
    local g = GImGui
    IM_ASSERT(g.Initialized)
    --IM_ASSERT(not g.WithinFrameScope, "Cannot be called between NewFrame() and EndFrame()")
    --IM_ASSERT(g.SettingsLoaded == false and g.FrameCount == 0)

    -- For user convenience, we allow passing a non zero-terminated string (hence the ini_size parameter).
    if ini_size and ini_size > 0 then ini_data = ini_data:sub(1, ini_size) end
    g.SettingsIniData = ini_data

    -- Call pre-read handlers
    -- Some types will clear their data (e.g. dock information) some types will allow merge/override (window)
    for _, handler in g.SettingsHandlers:iter() do
        if handler.ReadInitFn then handler.ReadInitFn(g, handler) end
    end

    local entry_data, entry_handler = nil, nil
    for line in ini_data:gmatch("[^\r\n]+") do
        local c = line:sub(1, 1)
        if c == ";" then
            -- comment
        elseif c == "[" and line:sub(-1) == "]" then
            -- Parse "[Type][Name]". Note that 'Name' can itself contains [] characters, which is acceptable with the current format and parsing code.
            local type_name, name = line:match("^%[([^%]]*)%]%[(.*)%]$")
            if type_name then
                entry_handler = ImGui.FindSettingsHandler(type_name)
                entry_data = entry_handler and entry_handler.ReadOpenFn(g, entry_handler, name) or nil
            else
                entry_handler, entry_data = nil, nil
            end
        elseif entry_handler ~= nil and entry_data ~= nil then
            -- Let type handler parse the line
            entry_handler.ReadLineFn(g, entry_handler, entry_data, line)
        end
    end
    g.SettingsLoaded = true

    -- Call post-read handlers
    for _, handler in g.SettingsHandlers:iter() do
        if handler.ApplyAllFn then handler.ApplyAllFn(g, handler) end
    end
end

function ImGui.SaveIniSettingsToDisk(ini_filename)
    local g = GImGui
    g.SettingsDirtyTimer = 0.0
    -- Roblox: no disk. Call SaveIniSettingsToMemory() and persist the string yourself (e.g. DataStore).
end

-- Call registered handlers (e.g. SettingsHandlerWindow_WriteAll() + custom handlers) to write their stuff into a text buffer
--- @return string ini_data, int size
function ImGui.SaveIniSettingsToMemory()
    local g = GImGui
    g.SettingsDirtyTimer = 0.0
    local buf = ImGuiTextBuffer()
    for _, handler in g.SettingsHandlers:iter() do
        handler.WriteAllFn(g, handler, buf)
    end
    g.SettingsIniData = buf:c_str()
    return g.SettingsIniData, #g.SettingsIniData
end

function ImGui.CreateNewWindowSettings(name)
    local g = GImGui

    -- Preserve the full string when ConfigDebugVerboseIniSettings is set to make .ini inspection easier.
    if not g.IO.ConfigDebugIniSettings then
        -- ImHashSkipUncontributingPrefix: skip everything up to the last "###"
        local p = name:match("^.*()###")
        if p then name = name:sub(p) end
    end
    local settings = ImGuiWindowSettings()
    settings.ID = ImHashStr(name)
    settings.Name = name
    g.SettingsWindows:push_back(settings)
    return settings
end

-- This will revert window to its initial state, including enabling the ImGuiCond.FirstUseEver/ImGuiCond.Once conditions once more.
function ImGui.ClearWindowSettings(name)
    --IMGUI_DEBUG_LOG("ClearWindowSettings('%s')\n", name)
    local window = ImGui.FindWindowByName(name)
    if window ~= nil then
        window.Flags = bit32.bor(window.Flags, ImGuiWindowFlags.NoSavedSettings)
        InitOrLoadWindowSettings(window, nil)
        if window.DockId and window.DockId ~= 0 and ImGui.DockContextProcessUndockWindow then
            ImGui.DockContextProcessUndockWindow(GImGui, window, true)
        end
    end
    local settings = window and ImGui.FindWindowSettingsByWindow(window) or ImGui.FindWindowSettingsByID(ImHashStr(name))
    if settings then settings.WantDelete = true end
end

local function WindowSettingsHandler_ClearAll(ctx, handler)
    local g = ctx
    for _, window in g.Windows:iter() do window.SettingsOffset = -1 end
    g.SettingsWindows:clear()
end

local function WindowSettingsHandler_ReadOpen(ctx, handler, name)
    local id = ImHashStr(name)
    local settings = ImGui.FindWindowSettingsByID(id)
    if settings then
        -- Clear existing if recycling previous entry
        local fresh = ImGuiWindowSettings()
        for k, v in pairs(fresh) do settings[k] = v end
        settings.Name = name
    else
        settings = ImGui.CreateNewWindowSettings(name)
    end
    settings.ID = id
    settings.WantApply = true
    return settings
end

local function WindowSettingsHandler_ReadLine(ctx, handler, settings, line)
    local x, y = line:match("^Pos=(%-?%d+),(%-?%d+)")
    if x then ImVec2_CopyV(settings.Pos, tonumber(x), tonumber(y)) return end
    x, y = line:match("^Size=(%-?%d+),(%-?%d+)")
    if x then ImVec2_CopyV(settings.Size, tonumber(x), tonumber(y)) return end
    x = line:match("^ViewportId=0x(%x+)")
    if x then settings.ViewportId = tonumber(x, 16) return end
    x, y = line:match("^ViewportPos=(%-?%d+),(%-?%d+)")
    if x then ImVec2_CopyV(settings.ViewportPos, tonumber(x), tonumber(y)) return end
    x = line:match("^Collapsed=(%d+)")
    if x then settings.Collapsed = tonumber(x) ~= 0 return end
    x = line:match("^IsChild=(%d+)")
    if x then settings.IsChild = tonumber(x) ~= 0 return end
    x = line:match("^LastUsed=(%d+)")
    if x then settings.LastUsedDate = tonumber(x) return end
    x, y = line:match("^DockId=0x(%x+),(%-?%d+)")
    if x then settings.DockId = tonumber(x, 16); settings.DockOrder = tonumber(y) return end
    x = line:match("^DockId=0x(%x+)")
    if x then settings.DockId = tonumber(x, 16); settings.DockOrder = -1 return end
    x = line:match("^ClassId=0x(%x+)")
    if x then settings.ClassId = tonumber(x, 16) return end
end

-- Apply to existing windows (if any)
local function WindowSettingsHandler_ApplyAll(ctx, handler)
    local g = ctx
    for _, settings in g.SettingsWindows:iter() do
        if settings.WantApply then
            local window = ImGui.FindWindowByID(settings.ID)
            if window then ApplyWindowSettings(window, settings) end
            settings.WantApply = false
        end
    end
end

local function WindowSettingsHandler_WriteAll(ctx, handler, buf)
    -- Gather data from windows that were active during this session
    -- (if a window wasn't opened in this session we preserve its settings)
    local g = ctx
    for _, window in g.Windows:iter() do
        if bit32.band(window.Flags, ImGuiWindowFlags.NoSavedSettings) == 0 then
            local settings = ImGui.FindWindowSettingsByWindow(window)
            if not settings then
                settings = ImGui.CreateNewWindowSettings(window.Name)
                window.SettingsOffset = g.SettingsWindows:index_from_ptr(settings)
            end
            IM_ASSERT(settings.ID == window.ID)
            ImVec2_CopyV(settings.Pos, ImTrunc(window.Pos.x - window.ViewportPos.x), ImTrunc(window.Pos.y - window.ViewportPos.y))
            ImVec2_CopyV(settings.Size, ImTrunc(window.SizeFull.x), ImTrunc(window.SizeFull.y))
            settings.ViewportId = window.ViewportId or 0
            ImVec2_CopyV(settings.ViewportPos, ImTrunc(window.ViewportPos.x), ImTrunc(window.ViewportPos.y))
            settings.DockId = window.DockId or 0
            settings.ClassId = window.WindowClass and window.WindowClass.ClassId or 0
            settings.DockOrder = window.DockOrder or -1
            settings.Collapsed = window.Collapsed
            settings.IsChild = (window.RootWindow ~= window) -- Cannot rely on ImGuiWindowFlags.ChildWindow here as docked windows have this set.
            settings.WantDelete = false
        end
    end

    -- Write to text buffer
    for _, settings in g.SettingsWindows:iter() do
        if not settings.WantDelete then
            buf:appendf("[%s][%s]\n", handler.TypeName, settings.Name) -- [Window][name]
            if settings.IsChild then
                buf:appendf("IsChild=1\n")
                buf:appendf("Size=%d,%d\n", settings.Size.x, settings.Size.y)
            else
                if settings.ViewportId ~= 0 and settings.ViewportId ~= IMGUI_VIEWPORT_DEFAULT_ID then
                    buf:appendf("ViewportPos=%d,%d\n", settings.ViewportPos.x, settings.ViewportPos.y)
                    buf:appendf("ViewportId=0x%08X\n", settings.ViewportId)
                end
                if settings.Pos.x ~= 0 or settings.Pos.y ~= 0 or settings.ViewportId == IMGUI_VIEWPORT_DEFAULT_ID then
                    buf:appendf("Pos=%d,%d\n", settings.Pos.x, settings.Pos.y)
                end
                if settings.Size.x ~= 0 or settings.Size.y ~= 0 then
                    buf:appendf("Size=%d,%d\n", settings.Size.x, settings.Size.y)
                end
                buf:appendf("Collapsed=%d\n", settings.Collapsed and 1 or 0)
                if settings.DockId ~= 0 then
                    --buf:appendf("TabId=0x%08X\n", ImHashStr("#TAB", 4, settings.ID)) -- window.TabId: this is not read back but writing it makes "debugging" the .ini data easier.
                    if settings.DockOrder == -1 then
                        buf:appendf("DockId=0x%08X\n", settings.DockId)
                    else
                        buf:appendf("DockId=0x%08X,%d\n", settings.DockId, settings.DockOrder)
                    end
                    if settings.ClassId ~= 0 then buf:appendf("ClassId=0x%08X\n", settings.ClassId) end
                end
            end
            buf:append("\n")
        end
    end
end

function ImGui.WindowSettingsAddSettingsHandler()
    local ini_handler = ImGuiSettingsHandler()
    ini_handler.TypeName = "Window"
    ini_handler.TypeHash = ImHashStr("Window")
    ini_handler.ClearAllFn = WindowSettingsHandler_ClearAll
    ini_handler.ReadOpenFn = WindowSettingsHandler_ReadOpen
    ini_handler.ReadLineFn = WindowSettingsHandler_ReadLine
    ini_handler.ApplyAllFn = WindowSettingsHandler_ApplyAll
    ini_handler.WriteAllFn = WindowSettingsHandler_WriteAll
    ImGui.AddSettingsHandler(ini_handler)
end

-------------------------------------------------------------------------------
-- [SECTION] LOGGING/CAPTURING
-------------------------------------------------------------------------------
-- All text output from the interface can be captured into tty/file/clipboard.
-- By default, tree nodes are automatically opened during logging.
-------------------------------------------------------------------------------

ImGuiLogFlags = ImGuiLogFlags or {
    None = 0, OutputTTY = 1, OutputFile = 2, OutputBuffer = 4, OutputClipboard = 8, OutputMask_ = 15,
}

-- Pass text data straight to log (without being displayed)
local function LogTextV_Internal(g, fmt, ...)
    local s = (select("#", ...) > 0) and string.format(fmt, ...) or fmt
    if g.LogFile then
        print(s) -- TTY (the only "file" available on Roblox)
    else
        g.LogBuffer:append(s)
    end
end

function ImGui.LogText(fmt, ...)
    local g = GImGui
    if not g.LogEnabled then return end
    LogTextV_Internal(g, fmt, ...)
end
ImGui.LogTextV = ImGui.LogText

-- Internal version that takes a position to decide on newline placement and pad items according to their depth.
-- We split text into individual lines to add current tree level padding
-- FIXME: This code is a little complicated perhaps, considering simplifying the whole system.
--- `text` is a Lua string, `text_begin/text_end` optional 1-based byte range (text_end exclusive).
function ImGui.LogRenderedText(ref_pos, text, text_end, text_begin)
    local g = GImGui
    local window = g.CurrentWindow

    local prefix, suffix = g.LogNextPrefix, g.LogNextSuffix
    g.LogNextPrefix = nil; g.LogNextSuffix = nil

    text_begin = text_begin or 1
    if not text_end then text_end = ImGui.FindRenderedTextEnd(text, text_end) end

    local log_new_line = ref_pos and (ref_pos.y > g.LogLinePosY + ImMax(g.Style.FramePadding.y, g.Style.ItemSpacing.y) + 1)
    if ref_pos then g.LogLinePosY = ref_pos.y end
    if log_new_line then
        ImGui.LogText("\n")
        g.LogLineFirstItem = true
    end

    if prefix then ImGui.LogRenderedText(ref_pos, prefix, #prefix + 1) end -- Calculate end ourself to ensure "##" are included here.

    -- Re-adjust padding if we have popped out of our starting depth
    if g.LogDepthRef > window.DC.TreeDepth then g.LogDepthRef = window.DC.TreeDepth end
    local tree_depth = window.DC.TreeDepth - g.LogDepthRef

    local text_remaining = text_begin
    while true do
        -- Split the string. Each new line (after a '\n') is followed by indentation corresponding to the current depth of our log entry.
        -- We don't add a trailing \n yet to allow a subsequent item on the same line to be captured.
        local line_start = text_remaining
        local nl = string.find(text, "\n", line_start, true)
        local line_end = (nl and nl < text_end) and nl or text_end
        local is_last_line = (line_end == text_end)
        if line_start ~= line_end or not is_last_line then
            local indentation = g.LogLineFirstItem and tree_depth * 4 or 1
            ImGui.LogText(string.rep(" ", indentation) .. string.sub(text, line_start, line_end - 1))
            g.LogLineFirstItem = false
            if string.byte(text, line_end) == 10 then
                ImGui.LogText("\n")
                g.LogLineFirstItem = true
            end
        end
        if is_last_line then break end
        text_remaining = line_end + 1
    end

    if suffix then ImGui.LogRenderedText(ref_pos, suffix, #suffix + 1) end
end

-- Start logging/capturing text output
function ImGui.LogBegin(flags, auto_open_depth)
    local g = GImGui
    local window = g.CurrentWindow
    IM_ASSERT(g.LogEnabled == false)
    g.LogEnabled = true; g.ItemUnclipByLog = true
    g.LogFlags = flags
    g.LogWindow = window
    g.LogNextPrefix = nil; g.LogNextSuffix = nil
    g.LogDepthRef = window.DC.TreeDepth
    g.LogDepthToExpand = ((auto_open_depth or -1) >= 0) and auto_open_depth or g.LogDepthToExpandDefault
    g.LogLinePosY = FLT_MAX
    g.LogLineFirstItem = true
    g.LogBuffer = ImGuiTextBuffer()
end

-- Important: doesn't copy underlying data, use carefully (prefix/suffix must be in scope at the time of the next LogRenderedText)
function ImGui.LogSetNextTextDecoration(prefix, suffix)
    local g = GImGui
    g.LogNextPrefix = prefix
    g.LogNextSuffix = suffix
end

function ImGui.LogToTTY(auto_open_depth)
    local g = GImGui
    if g.LogEnabled then return end
    ImGui.LogBegin(ImGuiLogFlags.OutputTTY, auto_open_depth or -1)
    g.LogFile = "stdout"
end

-- Start logging/capturing text output to given file
function ImGui.LogToFile(auto_open_depth, filename)
    -- Roblox: no file access. Falls back to TTY (output window).
    ImGui.LogToTTY(auto_open_depth)
end

-- Start logging/capturing text output to clipboard
function ImGui.LogToClipboard(auto_open_depth)
    local g = GImGui
    if g.LogEnabled then return end
    ImGui.LogBegin(ImGuiLogFlags.OutputClipboard, auto_open_depth or -1)
end

function ImGui.LogToBuffer(auto_open_depth)
    local g = GImGui
    if g.LogEnabled then return end
    ImGui.LogBegin(ImGuiLogFlags.OutputBuffer, auto_open_depth or -1)
end

function ImGui.LogFinish()
    local g = GImGui
    if not g.LogEnabled then return end
    ImGui.LogText("\n")
    local out = bit32.band(g.LogFlags, ImGuiLogFlags.OutputMask_)
    if out == ImGuiLogFlags.OutputClipboard then
        if not g.LogBuffer:empty() then ImGui.SetClipboardText(g.LogBuffer:c_str()) end
    end
    g.LogEnabled = false; g.ItemUnclipByLog = false
    g.LogFlags = ImGuiLogFlags.None
    g.LogFile = nil
    g.LogBuffer = ImGuiTextBuffer()
end

-- Helper to display logging buttons
-- FIXME-OBSOLETE: We should probably obsolete this and let the user have their own helper (this is one of the oldest function alive!)
function ImGui.LogButtons()
    local g = GImGui
    ImGui.PushID("LogButtons")
    local log_to_tty = ImGui.Button("Log To TTY"); ImGui.SameLine()
    local log_to_file = ImGui.Button("Log To File"); ImGui.SameLine()
    local log_to_clipboard = ImGui.Button("Log To Clipboard"); ImGui.SameLine()
    ImGui.PushItemFlag(ImGuiItemFlags.NoTabStop, true)
    ImGui.SetNextItemWidth(ImGui.CalcTextSize("999").x)
    g.LogDepthToExpandDefault = ImGui.SliderInt("Default Depth", g.LogDepthToExpandDefault, 0, 9, nil)
    ImGui.PopItemFlag()
    ImGui.PopID()

    -- Start logging at the end of the function so that the buttons don't appear in the log
    if log_to_tty then ImGui.LogToTTY() end
    if log_to_file then ImGui.LogToFile() end
    if log_to_clipboard then ImGui.LogToClipboard() end
end

--- @param window ImGuiWindow
--- @return ImGuiWindow?
local function GetWindowForTitleDisplay(window)
    if window.DockNodeAsHost then
        return window.DockNodeAsHost.VisibleWindow
    else
        return window
    end
end

-- Code not using ItemAdd() may need to call this manually otherwise ActiveId will be cleared. In IMGUI_VERSION_NUM < 18717 this was called by GetID().
--- @param id ImGuiID

function ImGui.KeepAliveID(id)
    local g = GImGui

    if g.ActiveId == id then
        g.ActiveIdIsAlive = id
    end

    if g.DeactivatedItemData.ID == id then
        g.DeactivatedItemData.IsAlive = true
    end
end

-- Test if mouse cursor is hovering given rectangle
-- NB- Rectangle is clipped by our current clip setting
-- NB- Expand the rectangle to be generous on imprecise inputs systems (g.Style.TouchExtraPadding)
--- @param r_min  ImVec2
--- @param r_max  ImVec2
--- @param clip?  bool

function ImGui.IsMouseHoveringRect(r_min, r_max, clip)
    if clip == nil then clip = true end

    local g = GImGui
    -- [Luau] scalar version of: rect_clipped = ImRect(r_min, r_max); ClipWith(window.ClipRect); ContainsWithPad(); viewport Overlaps()
    -- Clip
    local x0, y0, x1, y1 = r_min.x, r_min.y, r_max.x, r_max.y
    if clip then
        local cr = g.CurrentWindow.ClipRect
        local cmin, cmax = cr.Min, cr.Max
        x0 = math.max(x0, cmin.x); y0 = math.max(y0, cmin.y)
        x1 = math.min(x1, cmax.x); y1 = math.min(y1, cmax.y)
    end

    -- Hit testing, expanded for touch input
    local p, pad = g.IO.MousePos, g.Style.TouchExtraPadding
    if not (p.x >= x0 - pad.x and p.y >= y0 - pad.y and p.x < x1 + pad.x and p.y < y1 + pad.y) then
        return false
    end
    local vp = g.MouseViewport
    local vx0, vy0 = vp.Pos.x, vp.Pos.y
    local vx1, vy1 = vx0 + vp.Size.x, vy0 + vp.Size.y
    if not (vx0 <= x1 and vx1 >= x0 and vy0 <= y1 and vy1 >= y0) then
        return false
    end

    return true
end

-- Return if a mouse click/drag went past the given threshold. Valid to call during the MouseReleased frame.
-- [Internal] This doesn't test if the button is pressed
--- @param button          ImGuiMouseButton
--- @param lock_threshold? float
function ImGui.IsMouseDragPastThreshold(button, lock_threshold)
    if lock_threshold == nil then lock_threshold = -1.0 end

    local g = GImGui
    IM_ASSERT(button >= 0 and button < 3) -- IM_COUNTOF(g.IO.MouseDown)
    if lock_threshold < 0.0 then
        lock_threshold = g.IO.MouseDragThreshold
    end
    return g.IO.MouseDragMaxDistanceSqr[button] >= lock_threshold * lock_threshold
end

--- @param button          ImGuiMouseButton
--- @param lock_threshold? float
function ImGui.IsMouseDragging(button, lock_threshold)
    if lock_threshold == nil then lock_threshold = -1.0 end

    local g = GImGui
    IM_ASSERT(button >= 0 and button < 3) -- IM_COUNTOF(g.IO.MouseDown)
    if not g.IO.MouseDown[button] then
        return false
    end
    return ImGui.IsMouseDragPastThreshold(button, lock_threshold)
end

-- This is called TeleportMousePos() and not SetMousePos() to emphasis that setting MousePosPrev will effectively clear mouse delta as well.
-- It is expected you only call this if (io.BackendFlags & ImGuiBackendFlags.HasSetMousePos) is set and supported by backend.
--- @param pos ImVec2
function ImGui.TeleportMousePos(pos)
    local g = GImGui
    ImVec2_Copy(g.IO.MousePos, pos)
    ImVec2_Copy(g.IO.MousePosPrev, pos)
    ImVec2_CopyV(g.IO.MouseDelta, 0.0, 0.0)
    g.IO.WantSetMousePos = true
    -- IMGUI_DEBUG_LOG_IO("TeleportMousePos: (%.1f,%.1f)", io.MousePos.x, io.MousePos.y)
end

-- Called from within ItemAdd: at this point we can read from NextItemData and write to LastItemData
--- @param id ImGuiID
function ImGui.ItemHandleShortcut(id)
    local g = GImGui
    local flags = g.NextItemData.ShortcutFlags
    IM_ASSERT(bit32.band(flags, bit32.bnot(ImGuiInputFlags.SupportedBySetNextItemShortcut)) == 0) -- Passing flags not supported by SetNextItemShortcut()!

    if bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.Disabled) ~= 0 then
        return
    end
    if bit32.band(flags, ImGuiInputFlags.Tooltip) ~= 0 then
        g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HasShortcut)
        g.LastItemData.Shortcut = g.NextItemData.Shortcut
    end
    if not ImGui.Shortcut(g.NextItemData.Shortcut, bit32.band(flags, ImGuiInputFlags.SupportedByShortcut), id) or g.NavActivateId ~= 0 then
        return
    end

    -- FIXME: Generalize Activation queue?
    g.NavActivateId = id -- Will effectively disable clipping.
    g.NavActivateFlags = bit32.bor(ImGuiActivateFlags.PreferInput, ImGuiActivateFlags.FromShortcut)
    -- if (g.ActiveId == 0 || g.ActiveId == id)
    g.NavActivateDownId = id
    g.NavActivatePressedId = id
    ImGui.NavHighlightActivated(id)
end

-- Declare item bounding box for clipping and interaction.
-- Note that the size can be different than the one provided to ItemSize(). Typically, widgets that spread over available surface
-- declare their minimum size requirement to ItemSize() and provide a larger region to ItemAdd() which is used drawing/interaction.
-- THIS IS IN THE PERFORMANCE CRITICAL PATH (UNTIL THE CLIPPING TEST AND EARLY-RETURN)
--- @param bb           ImRect
--- @param id           ImGuiID
--- @param nav_bb_arg?  ImRect
--- @param extra_flags? ImGuiItemFlags

function ImGui.ItemAdd(bb, id, nav_bb_arg, extra_flags)
    if extra_flags == nil then extra_flags = 0 end

    local g = GImGui
    local window = g.CurrentWindow
    local last_item_data, next_item_data = g.LastItemData, g.NextItemData -- [Luau] cached field reads

    -- Set item data
    -- (DisplayRect is left untouched, made valid when ImGuiItemStatusFlags.HasDisplayRect is set)
    last_item_data.ID = id
    -- [Luau] inline ImRect_Copy(g.LastItemData.Rect, bb); ImRect_Copy(g.LastItemData.NavRect, nav_bb_arg or bb)
    local bb_min, bb_max = bb.Min, bb.Max
    local r = last_item_data.Rect
    r.Min.x = bb_min.x; r.Min.y = bb_min.y; r.Max.x = bb_max.x; r.Max.y = bb_max.y
    local nav_bb = nav_bb_arg and nav_bb_arg or bb
    r = last_item_data.NavRect
    r.Min.x = nav_bb.Min.x; r.Min.y = nav_bb.Min.y; r.Max.x = nav_bb.Max.x; r.Max.y = nav_bb.Max.y
    last_item_data.ItemFlags = bit32.bor(g.CurrentItemFlags, next_item_data.ItemFlagsSet, extra_flags)
    last_item_data.StatusFlags = ImGuiItemStatusFlags.None
    -- Note: we don't copy 'g.NextItemData.SelectionUserData' to an hypothetical g.LastItemData.SelectionUserData: since the former is not cleared.

    if id ~= 0 then
        -- [Luau] inline ImGui.KeepAliveID(id)
        if g.ActiveId == id then g.ActiveIdIsAlive = id end
        if g.DeactivatedItemData.ID == id then g.DeactivatedItemData.IsAlive = true end

        -- Directional navigation processing
        -- Runs prior to clipping early-out
        --  (a) So that NavInitRequest can be honored, for newly opened windows to select a default widget
        --  (b) So that we can scroll up/down past clipped items. This adds a small O(N) cost to regular navigation requests
        --      unfortunately, but it is still limited to one window. It may not scale very well for windows with ten of
        --      thousands of item, but at least NavMoveRequest is only set on user interaction, aka maximum once a frame.
        --      We could early out with "if (is_clipped && !g.NavInitRequest) return false;" but when we wouldn't be able
        --      to reach unclipped widgets. This would work if user had explicit scrolling control (e.g. mapped on a stick).
        -- We intentionally don't check if g.NavWindow ~= nil because g.NavAnyRequest should only be set when it is non nil.
        -- If we crash on a nil g.NavWindow we need to fix the bug elsewhere.
        if bit32.band(last_item_data.ItemFlags, ImGuiItemFlags.NoNav) == 0 then
            -- FIXME-NAV: investigate changing the window tests into a simple 'if (g.NavFocusScopeId == g.CurrentFocusScopeId)' test.
            window.DC.NavLayersActiveMaskNext = bit32.bor(window.DC.NavLayersActiveMaskNext, bit32.lshift(1, window.DC.NavLayerCurrent))

            if g.NavId == id or g.NavAnyRequest then
                if g.NavWindow.RootWindowForNav == window.RootWindowForNav then
                    if window == g.NavWindow or bit32.band(bit32.bor(window.ChildFlags, g.NavWindow.ChildFlags), ImGuiChildFlags.NavFlattened) ~= 0 then
                        ImGui.NavProcessItem()
                    end
                end
            end
        end

        if bit32.band(next_item_data.HasFlags, ImGuiNextItemDataFlags.HasShortcut) ~= 0 then
            ImGui.ItemHandleShortcut(id)
        end
    end

    -- Lightweight clear of SetNextItemXXX data.
    next_item_data.HasFlags = ImGuiNextItemDataFlags.None
    next_item_data.ItemFlagsSet = ImGuiItemFlags.None

    -- Clipping test
    -- (this is an inline copy of IsClippedEx() so we can reuse the is_rect_visible value, otherwise we'd do 'if (IsClippedEx(bb, id)) return false')
    -- g.NavActivateId is not necessarily == g.NavId, in the case of remote activation (e.g. shortcuts)
    local bmin, bmax, cr = bb.Min, bb.Max, window.ClipRect
    local is_rect_visible = bmin.x <= cr.Max.x and bmax.x >= cr.Min.x and bmin.y <= cr.Max.y and bmax.y >= cr.Min.y
    if not is_rect_visible then
        if id == 0 or not (id == g.ActiveId or id == g.ActiveIdPreviousFrame or id == g.NavId or id == g.NavActivateId or g.ItemUnclipByLog) then
            return false
        end
    end

    if id ~= 0 and g.DeactivatedItemData.ID == id then
        g.DeactivatedItemData.ElapseFrame = g.FrameCount
    end

    -- We need to calculate this now to take account of the current clipping rectangle (as items like Selectable may change them)
    if is_rect_visible then
        last_item_data.StatusFlags = bit32.bor(last_item_data.StatusFlags, ImGuiItemStatusFlags.Visible)
    end

    if ImGui.IsMouseHoveringRect(bb.Min, bb.Max) then
        last_item_data.StatusFlags = bit32.bor(last_item_data.StatusFlags, ImGuiItemStatusFlags.HoveredRect)
    end

    return true
end

-------------------------------------------------------------------------------
-- [SECTION] LAYOUT
-------------------------------------------------------------------------------
-- - ItemSize()
-- - SameLine()
-- - GetCursorScreenPos()
-- - SetCursorScreenPos()
-- - GetCursorPos(), GetCursorPosX(), GetCursorPosY()
-- - SetCursorPos(), SetCursorPosX(), SetCursorPosY()
-- - GetCursorStartPos()
-- - Indent()
-- - Unindent()
-- - SetNextItemWidth()
-- - PushItemWidth()
-- - PushMultiItemsWidths()
-- - PopItemWidth()
-- - CalcItemWidth()
-- - CalcItemSize()
-- - GetTextLineHeight()
-- - GetTextLineHeightWithSpacing()
-- - GetFrameHeight()
-- - GetFrameHeightWithSpacing()
-- - GetContentRegionMax()
-- - GetContentRegionAvail(),
-- - BeginGroup()
-- - EndGroup()
-- Also see in imgui_widgets: tab bars, and in imgui_tables: tables, columns.
-------------------------------------------------------------------------------

-- Advance cursor given item size for layout.
-- Register minimum needed size so it can extend the bounding box used for auto-fit calculation.
-- See comments in ItemAdd() about how/why the size provided to ItemSize() vs ItemAdd() may often different.
-- THIS IS IN THE PERFORMANCE CRITICAL PATH.
--- @param size_or_bb       ImVec2|ImRect
--- @param text_baseline_y? float

function ImGui.ItemSize(size_or_bb, text_baseline_y)
    if text_baseline_y == nil then text_baseline_y = -1.0 end

    local size_x, size_y
    local bb_min = rawget(size_or_bb, "Min") -- [Luau] rawget: `.Min` on an ImVec2 would go through IM_VEC2.__index
    if bb_min then
        --- @cast size_or_bb ImRect
        size_x = size_or_bb.Max.x - bb_min.x; size_y = size_or_bb.Max.y - bb_min.y
    else
        --- @cast size_or_bb ImVec2
        size_x = size_or_bb.x; size_y = size_or_bb.y
    end

    local g = GImGui
    local window = g.CurrentWindow

    if window.SkipItems then
        return
    end
    local dc = window.DC
    local mathMax = math.max

    -- We increase the height in this function to accommodate for baseline offset.
    -- In theory we should be offsetting the starting position (window.DC.CursorPos), that will be the topic of a larger refactor,
    -- but since ItemSize() is not yet an API that moves the cursor (to handle e.g. wrapping) enlarging the height has the same effect.
    local offset_to_match_baseline_y
    if text_baseline_y >= 0 then
        offset_to_match_baseline_y = mathMax(0, dc.CurrLineTextBaseOffset - text_baseline_y)
    else
        offset_to_match_baseline_y = 0
    end

    local cursor, prev_line, max_pos = dc.CursorPos, dc.CursorPosPrevLine, dc.CursorMaxPos
    local line_y1
    if dc.IsSameLine then
        line_y1 = prev_line.y
    else
        line_y1 = cursor.y
    end

    local line_height = mathMax(dc.CurrLineSize.y, cursor.y - line_y1 + size_y + offset_to_match_baseline_y)
    local spacing_y = g.Style.ItemSpacing.y

    -- Always align ourselves on pixel boundaries
    -- if (g.IO.KeyAlt) window.DrawList:AddRect(window.DC.CursorPos, window.DC.CursorPos + ImVec2(size.x, line_height), IM_COL32(255,0,0,200)) -- [DEBUG]
    prev_line.x = cursor.x + size_x
    prev_line.y = line_y1
    cursor.x = math.floor(window.Pos.x + dc.Indent.x + dc.ColumnsOffset.x) -- Next line
    cursor.y = math.floor(line_y1 + line_height + spacing_y)               -- Next line
    max_pos.x = mathMax(max_pos.x, prev_line.x)
    max_pos.y = mathMax(max_pos.y, cursor.y - spacing_y)
    -- if (g.IO.KeyAlt) window.DrawList:AddCircle(window.DC.CursorMaxPos, 3.0, IM_COL32(255,0,0,255), 4) -- [DEBUG]

    dc.PrevLineSize.y = line_height
    dc.CurrLineSize.y = 0
    dc.PrevLineTextBaseOffset = mathMax(dc.CurrLineTextBaseOffset, text_baseline_y)
    dc.CurrLineTextBaseOffset = 0
    dc.IsSetPos = false
    dc.IsSameLine = false

    -- Horizontal layout mode
    if (dc.LayoutType == ImGuiLayoutType.Horizontal) then
        ImGui.SameLine()
    end
end

-- Gets back to previous line and continue with horizontal layout
--      offset_from_start_x == 0 : follow right after previous item
--      offset_from_start_x != 0 : align to specified x position (relative to window/group left)
--      spacing_w < 0            : use default spacing if offset_from_start_x == 0, no spacing if offset_from_start_x != 0
--      spacing_w >= 0           : enforce spacing amount
--- @param offset_from_start_x float?
--- @param spacing_w           float?

function ImGui.SameLine(offset_from_start_x, spacing_w)
    if offset_from_start_x == nil then offset_from_start_x =  0.0 end
    if spacing_w           == nil then spacing_w           = -1.0 end

    local g = GImGui
    local window = g.CurrentWindow

    if window.SkipItems then
        return
    end

    local dc = window.DC -- [Luau] cached field read
    if offset_from_start_x ~= 0.0 then
        if spacing_w < 0.0 then spacing_w = 0.0 end
        dc.CursorPos.x = window.Pos.x - window.Scroll.x + offset_from_start_x + spacing_w + dc.GroupOffset.x + dc.ColumnsOffset.x
        dc.CursorPos.y = dc.CursorPosPrevLine.y
    else
        if spacing_w < 0.0 then spacing_w = g.Style.ItemSpacing.x end
        dc.CursorPos.x = dc.CursorPosPrevLine.x + spacing_w
        dc.CursorPos.y = dc.CursorPosPrevLine.y
    end
    dc.CurrLineSize.x = dc.PrevLineSize.x; dc.CurrLineSize.y = dc.PrevLineSize.y -- [Luau] inline ImVec2_Copy()
    dc.CurrLineTextBaseOffset = dc.PrevLineTextBaseOffset
    dc.IsSameLine = true
end

--- @param indent_w? float
function ImGui.Indent(indent_w)
    if indent_w == nil then indent_w = 0.0 end

    local g = GImGui
    local window = ImGui.GetCurrentWindow()

    if indent_w ~= 0.0 then
        window.DC.Indent.x = window.DC.Indent.x + indent_w
    else
        window.DC.Indent.x = window.DC.Indent.x + g.Style.IndentSpacing
    end

    window.DC.CursorPos.x = window.Pos.x + window.DC.Indent.x + window.DC.ColumnsOffset.x
end

--- @param indent_w? float
function ImGui.Unindent(indent_w)
    if indent_w == nil then indent_w = 0.0 end

    local g = GImGui
    local window = ImGui.GetCurrentWindow()

    if indent_w ~= 0.0 then
        window.DC.Indent.x = window.DC.Indent.x - indent_w
    else
        window.DC.Indent.x = window.DC.Indent.x - g.Style.IndentSpacing
    end

    window.DC.CursorPos.x = window.Pos.x + window.DC.Indent.x + window.DC.ColumnsOffset.x
end

-- Affect large frame+labels widgets only.
--- @param item_width float
function ImGui.SetNextItemWidth(item_width)
    local g = GImGui
    g.NextItemData.HasFlags = bit32.bor(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasWidth)
    g.NextItemData.Width = item_width
end

-- FIXME: Remove the == 0.0f behavior?
--- @param item_width float
function ImGui.PushItemWidth(item_width)
    local g = GImGui
    local window = g.CurrentWindow
    -- [Luau] inline window.DC.ItemWidthStack:push_back(window.DC.ItemWidth) -- Backup current width
    local stack = window.DC.ItemWidthStack
    local n = stack.Size + 1
    if n > stack.Capacity then stack:push_back(window.DC.ItemWidth) else stack.Data[n] = window.DC.ItemWidth; stack.Size = n end
    window.DC.ItemWidth = (item_width == 0.0) and window.DC.ItemWidthDefault or item_width
    g.NextItemData.HasFlags = bit32.band(g.NextItemData.HasFlags, bit32.bnot(ImGuiNextItemDataFlags.HasWidth))
end

function ImGui.PopItemWidth()
    local g = GImGui
    local window = g.CurrentWindow
    if window.DC.ItemWidthStack.Size <= 0 then
        IM_ASSERT_USER_ERROR(false, "Calling PopItemWidth() too many times!")
        return
    end
    local stack = window.DC.ItemWidthStack
    window.DC.ItemWidth = stack.Data[stack.Size] -- [Luau] inline back()/pop_back()
    stack.Size = stack.Size - 1
end

--- @param components int
--- @param w_full     float
function ImGui.PushMultiItemsWidths(components, w_full)
    local g = GImGui
    local window = g.CurrentWindow
    IM_ASSERT(components > 0)
    local style = g.Style
    window.DC.ItemWidthStack:push_back(window.DC.ItemWidth) -- Backup current width
    local w_items = w_full - style.ItemInnerSpacing.x * (components - 1)
    local prev_split = w_items
    for i = components - 1, 1, -1 do
        local next_split = IM_TRUNC(w_items * i / components)
        window.DC.ItemWidthStack:push_back(ImMax(prev_split - next_split, 1.0))
        prev_split = next_split
    end
    window.DC.ItemWidth = ImMax(prev_split, 1.0)
    g.NextItemData.HasFlags = bit32.band(g.NextItemData.HasFlags, bit32.bnot(ImGuiNextItemDataFlags.HasWidth))
end

--- @return float
function ImGui.GetFrameHeight()
    local g = GImGui
    return g.FontSize + g.Style.FramePadding.y * 2.0
end

--- @return ImVec2
--- @nodiscard

function ImGui.GetContentRegionAvail()
    local g = GImGui
    local window = g.CurrentWindow

    local mx
    if window.DC.CurrentColumns or g.CurrentTable then
        mx = window.WorkRect.Max
    else
        mx = window.ContentRegionRect.Max
    end

    return ImVec2(mx.x - window.DC.CursorPos.x, mx.y - window.DC.CursorPos.y)
end

--- @return ImVec2
--- @nodiscard
function ImGui.GetCursorScreenPos()
    local window = ImGui.GetCurrentWindowRead()
    local ret = ImVec2()
    ImVec2_Copy(ret, window.DC.CursorPos)
    return ret
end

--- @param pos ImVec2
function ImGui.SetCursorScreenPos(pos)
    local window = ImGui.GetCurrentWindow()
    ImVec2_Copy(window.DC.CursorPos, pos)
    -- window.DC.CursorMaxPos = ImMax(window.DC.CursorMaxPos, window.DC.CursorPos)
    window.DC.IsSetPos = true
end

-- User generally sees positions in window coordinates. Internally we store CursorPos in absolute screen coordinates because it is more convenient.
-- Conversion happens as we pass the value to user, but it makes our naming convention confusing because GetCursorPos() == (DC.CursorPos - window.Pos). May want to rename 'DC.CursorPos'.
--- @return ImVec2
function ImGui.GetCursorPos()
    local window = ImGui.GetCurrentWindowRead()
    return ImVec2(window.DC.CursorPos.x - window.Pos.x + window.Scroll.x, window.DC.CursorPos.y - window.Pos.y + window.Scroll.y)
end

function ImGui.GetCursorPosX()
    local window = ImGui.GetCurrentWindowRead()
    return window.DC.CursorPos.x - window.Pos.x + window.Scroll.x
end

function ImGui.GetCursorPosY()
    local window = ImGui.GetCurrentWindowRead()
    return window.DC.CursorPos.y - window.Pos.y + window.Scroll.y
end

--- @param local_pos ImVec2
function ImGui.SetCursorPos(local_pos)
    local window = ImGui.GetCurrentWindow()
    ImVec2_CopyV(window.DC.CursorPos, window.Pos.x - window.Scroll.x + local_pos.x, window.Pos.y - window.Scroll.y + local_pos.y)
    -- window.DC.CursorMaxPos = ImMax(window.DC.CursorMaxPos, window.DC.CursorPos)
    window.DC.IsSetPos = true
end

--- @param x float
function ImGui.SetCursorPosX(x)
    local window = ImGui.GetCurrentWindow()
    window.DC.CursorPos.x = window.Pos.x - window.Scroll.x + x
    -- window.DC.CursorMaxPos.x = ImMax(window.DC.CursorMaxPos.x, window.DC.CursorPos.x)
    window.DC.IsSetPos = true
end

--- @param y float
function ImGui.SetCursorPosY(y)
    local window = ImGui.GetCurrentWindow()
    window.DC.CursorPos.y = window.Pos.y - window.Scroll.y + y
    -- window.DC.CursorMaxPos.y = ImMax(window.DC.CursorMaxPos.y, window.DC.CursorPos.y)
    window.DC.IsSetPos = true
end

--- @return ImVec2
function ImGui.GetCursorStartPos()
    local window = ImGui.GetCurrentWindowRead()
    return window.DC.CursorStartPos - window.Pos
end

function ImGui.GetFrameHeightWithSpacing()
    local g = GImGui
    return g.FontSize + g.Style.FramePadding.y * 2.0 + g.Style.ItemSpacing.y
end

function ImGui.GetTextLineHeightWithSpacing()
    local g = GImGui
    return g.FontSize + g.Style.ItemSpacing.y
end

-- You should never need those functions. Always use GetCursorScreenPos() and GetContentRegionAvail()!
-- They are bizarre local-coordinates which don't play well with scrolling.
--- @return ImVec2
function ImGui.GetContentRegionMax()
    local window = GImGui.CurrentWindow
    return ImGui.GetContentRegionAvail() + window.DC.CursorPos - window.Pos
end

--- @return ImVec2
function ImGui.GetWindowContentRegionMin()
    local window = GImGui.CurrentWindow
    return window.ContentRegionRect.Min - window.Pos
end

--- @return ImVec2
function ImGui.GetWindowContentRegionMax()
    local window = GImGui.CurrentWindow
    return window.ContentRegionRect.Max - window.Pos
end

-- Overloads: IsRectVisible(size) / IsRectVisible(rect_min, rect_max)
function ImGui.IsRectVisible(a, b)
    local window = GImGui.CurrentWindow
    if b == nil then
        return window.ClipRect:Overlaps(ImRect(window.DC.CursorPos, window.DC.CursorPos + a))
    end
    return window.ClipRect:Overlaps(ImRect(a, b))
end

-- Lock horizontal starting position + capture group bounding box into one "item" (so you can use IsItemHovered() or layout primitives such as SameLine() on whole group, etc.)
-- Groups are currently a mishmash of functionalities which should perhaps be clarified and separated.
-- FIXME-OPT: Could we safely early out on ->SkipItems?

function ImGui.BeginGroup()
    local g = GImGui
    local window = g.CurrentWindow

    local group_data = ImGuiGroupData()
    group_data.WindowID = window.ID
    ImVec2_Copy(group_data.BackupCursorPos, window.DC.CursorPos)
    ImVec2_Copy(group_data.BackupCursorPosPrevLine, window.DC.CursorPosPrevLine)
    ImVec2_Copy(group_data.BackupCursorMaxPos, window.DC.CursorMaxPos)
    ImVec1_Copy(group_data.BackupIndent, window.DC.Indent)
    ImVec1_Copy(group_data.BackupGroupOffset, window.DC.GroupOffset)
    ImVec2_Copy(group_data.BackupCurrLineSize, window.DC.CurrLineSize)
    group_data.BackupCurrLineTextBaseOffset = window.DC.CurrLineTextBaseOffset
    group_data.BackupActiveIdIsAlive = g.ActiveIdIsAlive
    group_data.BackupHoveredIdIsAlive = (g.HoveredId ~= 0)
    group_data.BackupIsSameLine = window.DC.IsSameLine
    group_data.BackupAnyIdHasBeenEditedThisFrame = g.AnyIdHasBeenEditedThisFrame
    group_data.BackupDeactivatedIdIsAlive = g.DeactivatedItemData.IsAlive
    group_data.EmitItem = true

    g.GroupStack:push_back(group_data)

    window.DC.GroupOffset.x = window.DC.CursorPos.x - window.Pos.x - window.DC.ColumnsOffset.x
    ImVec1_Copy(window.DC.Indent, window.DC.GroupOffset)
    ImVec2_Copy(window.DC.CursorMaxPos, window.DC.CursorPos)
    ImVec2_CopyV(window.DC.CurrLineSize, 0.0, 0.0)
    if (g.LogEnabled) then
        g.LogLinePosY = -FLT_MAX -- To enforce a carriage return
    end
end


function ImGui.EndGroup()
    local g = GImGui
    local window = g.CurrentWindow
    IM_ASSERT(g.GroupStack.Size > 0) -- Mismatched BeginGroup()/EndGroup() calls

    local group_data = g.GroupStack:back()
    IM_ASSERT(group_data.WindowID == window.ID) -- EndGroup() in wrong window?

    if (window.DC.IsSetPos) then
        -- TODO: ImGui.ErrorCheckUsingSetCursorPosToExtendParentBoundaries()
    end

    -- Include LastItemData.Rect.Max as a workaround for e.g. EndTable() undershooting with CursorMaxPos report. (#7543)
    local group_bb = ImRect(group_data.BackupCursorPos, ImMax(ImMax(window.DC.CursorMaxPos, g.LastItemData.Rect.Max), group_data.BackupCursorPos))
    ImVec2_Copy(window.DC.CursorPos, group_data.BackupCursorPos)
    ImVec2_Copy(window.DC.CursorPosPrevLine, group_data.BackupCursorPosPrevLine)
    ImVec2_Copy(window.DC.CursorMaxPos, ImMax(group_data.BackupCursorMaxPos, group_bb.Max))
    ImVec1_Copy(window.DC.Indent, group_data.BackupIndent)
    ImVec1_Copy(window.DC.GroupOffset, group_data.BackupGroupOffset)
    ImVec2_Copy(window.DC.CurrLineSize, group_data.BackupCurrLineSize)
    window.DC.CurrLineTextBaseOffset = group_data.BackupCurrLineTextBaseOffset
    window.DC.IsSameLine = group_data.BackupIsSameLine
    if (g.LogEnabled) then
        g.LogLinePosY = -FLT_MAX -- To enforce a carriage return
    end

    if (not group_data.EmitItem) then
        g.GroupStack:pop_back()
        return
    end

    window.DC.CurrLineTextBaseOffset = ImMax(window.DC.PrevLineTextBaseOffset, group_data.BackupCurrLineTextBaseOffset) -- FIXME: Incorrect, we should grab the base offset from the *first line* of the group but it is hard to obtain now.
    ImGui.ItemSize(group_bb:GetSize())
    ImGui.ItemAdd(group_bb, 0, nil, ImGuiItemFlags.NoTabStop)

    -- If the current ActiveId was declared within the boundary of our group, we copy it to LastItemId so IsItemActive(), IsItemDeactivated() etc. will be functional on the entire group.
    -- It would be neater if we replaced window.DC.LastItemId by e.g. 'bool LastItemIsActive', but would put a little more burden on individual widgets.
    -- Also if you grep for LastItemId you'll notice it is only used in that context.
    -- (The two tests not the same because ActiveIdIsAlive is an ID itself, in order to be able to handle ActiveId being overwritten during the frame.)
    local group_contains_curr_active_id = (group_data.BackupActiveIdIsAlive ~= g.ActiveId) and (g.ActiveIdIsAlive == g.ActiveId) and g.ActiveId
    local group_contains_deactivated_id = (group_data.BackupDeactivatedIdIsAlive == false) and (g.DeactivatedItemData.IsAlive == true)
    if group_contains_curr_active_id then
        g.LastItemData.ID = g.ActiveId
    elseif group_contains_deactivated_id then
        g.LastItemData.ID = g.DeactivatedItemData.ID
    end
    ImRect_Copy(g.LastItemData.Rect, group_bb)

    -- Forward Hovered flag
    local group_contains_curr_hovered_id = (group_data.BackupHoveredIdIsAlive == false) and g.HoveredId ~= 0
    if group_contains_curr_hovered_id then
        g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HoveredWindow)
    end

    -- Forward Edited flag
    if g.AnyIdHasBeenEditedThisFrame and not group_data.BackupAnyIdHasBeenEditedThisFrame then
        g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.Edited)
    end

    -- Forward Deactivated flag
    g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HasDeactivated)
    if group_contains_deactivated_id then
        g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.Deactivated)
    end

    g.GroupStack:pop_back()
    if g.DebugShowGroupRects then
        window.DrawList:AddRect(group_bb.Min, group_bb.Max, IM_COL32(255, 0, 255, 255)) -- [Debug]
    end
end

-- Calculate default item width given value passed to PushItemWidth() or SetNextItemWidth().
-- The SetNextItemWidth() data is generally cleared/consumed by ItemAdd() or NextItemData.ClearFlags()

function ImGui.CalcItemWidth()
    local g = GImGui
    local window = g.CurrentWindow

    local w
    if bit32.band(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasWidth) ~= 0 then
        w = g.NextItemData.Width
    else
        w = window.DC.ItemWidth
    end

    if w < 0.0 then
        -- [Luau] scalar GetContentRegionAvail().x, no temporary ImVec2
        local mx = (window.DC.CurrentColumns or g.CurrentTable) and window.WorkRect.Max or window.ContentRegionRect.Max
        local region_avail_x = mx.x - window.DC.CursorPos.x
        w = math.max(1.0, region_avail_x + w)
    end

    w = IM_TRUNC(w)
    return w
end

-- [Internal] Calculate full item size given user provided 'size' parameter and default width/height. Default width is often == CalcItemWidth().
-- Those two functions CalcItemWidth vs CalcItemSize are awkwardly named because they are not fully symmetrical.
-- Note that only CalcItemWidth() is publicly exposed.
-- The 4.0f here may be changed to match CalcItemWidth() and/or BeginChild() (right now we have a mismatch which is harmless but undesirable)
--- @param size      ImVec2
--- @param default_w float
--- @param default_h float
--- @return ImVec2
function ImGui.CalcItemSize(size, default_w, default_h)
    local avail_x, avail_y
    if size.x < 0.0 or size.y < 0.0 then
        -- [Luau] scalar GetContentRegionAvail(), no temporary ImVec2
        local g = GImGui
        local window = g.CurrentWindow
        local mx = (window.DC.CurrentColumns or g.CurrentTable) and window.WorkRect.Max or window.ContentRegionRect.Max
        avail_x = mx.x - window.DC.CursorPos.x; avail_y = mx.y - window.DC.CursorPos.y
    end

    if size.x == 0.0 then
        size.x = default_w
    elseif size.x < 0.0 then
        size.x = math.max(4.0, avail_x + size.x)  -- <-- size.x is negative here so we are subtracting
    end

    if size.y == 0.0 then
        size.y = default_h
    elseif size.y < 0.0 then
        size.y = math.max(4.0, avail_y + size.y)  -- <-- size.y is negative here so we are subtracting
    end

    return size
end

function ImGui.GetTextLineHeight()
    local g = GImGui
    return g.FontSize
end

function ImGui.IsItemActive()
    local g = GImGui

    if g.ActiveId ~= 0 then
        return g.ActiveId == g.LastItemData.ID
    end

    return false
end

-- == (GetItemID() == GetFocusID() && GetFocusID() != 0)
function ImGui.IsItemFocused()
    local g = GImGui
    if g.NavId ~= g.LastItemData.ID or g.NavId == 0 then
        return false
    end

    -- Special handling for the dummy item after Begin() which represent the title bar or tab.
    -- When the window is collapsed (SkipItems==true) that last item will never be overwritten so we need to detect the case.
    local window = g.CurrentWindow
    if g.LastItemData.ID == window.ID and window.WriteAccessed then
        return false
    end

    return true
end

function ImGui.IsItemDeactivated()
    local g = GImGui
    if bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HasDeactivated) ~= 0 then
        return bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.Deactivated) ~= 0
    end
    return g.DeactivatedItemData.ID == g.LastItemData.ID and g.LastItemData.ID ~= 0 and g.DeactivatedItemData.ElapseFrame >= g.FrameCount
end

-- Since 1.92.9: consider using NoLiveEdit flags if all you need to that values are not written bo backing variable while typing.
function ImGui.IsItemDeactivatedAfterEdit()
    local g = GImGui
    return ImGui.IsItemDeactivated() and g.DeactivatedItemData.HasBeenEditedBefore
end

function ImGui.IsItemActivated()
    local g = GImGui
    if g.ActiveId ~= 0 then
        if g.ActiveId == g.LastItemData.ID and g.ActiveIdPreviousFrame ~= g.LastItemData.ID then
            return true
        end
    end
    return false
end

-- Important: this can be useful but it is NOT equivalent to the behavior of e.g.Button()!
-- Most widgets have specific reactions based on mouse-up/down state, mouse position etc.
--- @param mouse_button? ImGuiMouseButton
function ImGui.IsItemClicked(mouse_button)
    if mouse_button == nil then mouse_button = 0 end
    return ImGui.IsMouseClicked(mouse_button) and ImGui.IsItemHovered(ImGuiHoveredFlags.None)
end

function ImGui.IsItemToggledOpen()
    return bit32.band(GImGui.LastItemData.StatusFlags, ImGuiItemStatusFlags.ToggledOpen) ~= 0
end

-- Call after a Selectable() or TreeNode() items inside a BeginMultiSelect()/EndMultiSelect() scope.
-- - Useful if you need the per-item information before reaching EndMultiSelect(), e.g. for rendering purpose.
-- Outside of a multi-select block:
-- - It would be misleading/ambiguous to report this signal, as widgets return e.g. a pressed event,
--   and user code is in charge of altering selection in ways we cannot predict.
--   Prefer using 'if (IsItemClicked() && !IsItemToggledOpen())' for a manual reimplementation of selection.
function ImGui.IsItemToggledSelection()
    local g = GImGui
    IM_ASSERT(g.CurrentMultiSelect ~= nil) -- Can only be used inside a BeginMultiSelect()/EndMultiSelect()
    return bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.ToggledSelection) ~= 0
end

-- IMPORTANT: If you are trying to check whether your mouse should be dispatched to Dear ImGui or to your underlying app,
-- you should not use this function! Use the 'io.WantCaptureMouse' boolean for that!
-- Refer to FAQ entry "How can I tell whether to dispatch mouse/keyboard to Dear ImGui or my application?" for details.
function ImGui.IsAnyItemHovered()
    local g = GImGui
    return g.HoveredId ~= 0 or g.HoveredIdPreviousFrame ~= 0
end

function ImGui.IsAnyItemActive()
    return GImGui.ActiveId ~= 0
end

function ImGui.IsAnyItemFocused()
    local g = GImGui
    return g.NavId ~= 0 and g.NavCursorVisible
end

function ImGui.IsItemVisible()
    return bit32.band(GImGui.LastItemData.StatusFlags, ImGuiItemStatusFlags.Visible) ~= 0
end

function ImGui.IsItemEdited()
    return bit32.band(GImGui.LastItemData.StatusFlags, ImGuiItemStatusFlags.Edited) ~= 0
end

-- Allow next item to be overlapped by subsequent items.
-- This works by requiring HoveredId to match for two subsequent frames,
-- so if a following items overwrite it our interactions will naturally be disabled.
function ImGui.SetNextItemAllowOverlap()
    local g = GImGui
    g.NextItemData.ItemFlagsSet = bit32.bor(g.NextItemData.ItemFlagsSet, ImGuiItemFlags.AllowOverlap)
end

function ImGui.GetItemID()
    return GImGui.LastItemData.ID
end

function ImGui.GetItemFlags()
    return GImGui.LastItemData.ItemFlags
end

--- @return ImVec2
function ImGui.GetItemRectSize()
    return GImGui.LastItemData.Rect:GetSize()
end

function ImGui.GetHoveredID()
    local g = GImGui
    return (g.HoveredId ~= 0) and g.HoveredId or g.HoveredIdPreviousFrame
end

-------------------------------------------------------------------------------
-- [SECTION] WINDOW FOCUS
-------------------------------------------------------------------------------
-- - SetWindowFocus()
-- - SetNextWindowFocus()
-- - IsWindowFocused()
-- - UpdateWindowInFocusOrderList() [Internal]
-- - BringWindowToFocusFront() [Internal]
-- - BringWindowToDisplayFront() [Internal]
-- - BringWindowToDisplayBack() [Internal]
-- - BringWindowToDisplayBehind() [Internal]
-- - FindWindowDisplayIndex() [Internal]
-- - FocusWindow() [Internal]
-- - FocusTopMostWindowUnderOne() [Internal]
-------------------------------------------------------------------------------

-- Moving window to front of display and set focus (which happens to be back of our sorted list)
--- @param window? ImGuiWindow
--- @param flags?  ImGuiFocusRequestFlags
function ImGui.FocusWindow(window, flags)
    if flags == nil then flags = 0 end

    local g = GImGui

    -- Modal check?
    if bit32.band(flags, ImGuiFocusRequestFlags.UnlessBelowModal) ~= 0 and g.NavWindow ~= window then -- Early out in common case.
        local blocking_modal = ImGui.FindBlockingModal(window)
        if blocking_modal then
            -- This block would typically be reached in two situations:
            -- - API call to FocusWindow() with a window under a modal and ImGuiFocusRequestFlags.UnlessBelowModal flag.
            -- - User clicking on void or anything behind a modal while a modal is open (window == nil)
            -- IMGUI_DEBUG_LOG_FOCUS("[focus] FocusWindow(\"%s\", UnlessBelowModal): prevented by \"%s\".", window ? window->Name : "<NULL>", blocking_modal->Name)
            if window and window == window.RootWindow and bit32.band(window.Flags, ImGuiWindowFlags.NoBringToFrontOnFocus) == 0 then
                ImGui.BringWindowToDisplayBehind(window, blocking_modal) -- Still bring right under modal. (FIXME: Could move in focus list too?)
            end
            ImGui.ClosePopupsOverWindow(ImGui.GetTopMostPopupModal(), false) -- Note how we need to use GetTopMostPopupModal() aad NOT blocking_modal, to handle nested modals
            return
        end
    end

    -- Find last focused child (if any) and focus it instead.
    if bit32.band(flags, ImGuiFocusRequestFlags.RestoreFocusedChild) ~= 0 and window ~= nil then
        window = ImGui.NavRestoreLastChildNavWindow(window)
    end

    -- Apply focus
    if g.NavWindow ~= window then
        ImGui.SetNavWindow(window)
        if window and g.NavHighlightItemUnderNav then
            g.NavMousePosDirty = true
        end
        g.NavId = window and window.NavLastIds[0] or 0 -- Restore NavId
        g.NavLayer = ImGuiNavLayer.Main
        ImGui.SetNavFocusScope(window and window.NavRootFocusScopeId or 0)
        g.NavIdIsAlive = false
        g.NavLastValidSelectionUserData = ImGuiSelectionUserData_Invalid

        -- Close popups if any
        ImGui.ClosePopupsOverWindow(window, false)
    end

    -- Move the root window to the top of the pile
    IM_ASSERT(window == nil or window.RootWindowDockTree ~= nil)
    local focus_front_window = window and window.RootWindow or nil
    local display_front_window = window and window.RootWindowDockTree or nil
    local dock_node = window and window.DockNode or nil
    local active_id_window_is_dock_node_host = g.ActiveIdWindow and dock_node and dock_node.HostWindow == g.ActiveIdWindow

    -- Steal active widgets. Some of the cases it triggers includes:
    -- - Focus a window while an InputText in another window is active, if focus happens before the old InputText can run.
    -- - When using Nav to activate menu items (due to timing of activating on press->new window appears->losing ActiveId)
    -- - Using dock host items (tab, collapse button) can trigger this before we redirect the ActiveIdWindow toward the child window.
    if g.ActiveId ~= 0 and g.ActiveIdWindow and g.ActiveIdWindow.RootWindow ~= focus_front_window then
        if not g.ActiveIdNoClearOnFocusLoss and not active_id_window_is_dock_node_host then
            ImGui.ClearActiveID()
        end
    end

    -- Passing nil allow to disable keyboard focus
    if not window then
        return
    end
    window.LastFrameJustFocused = g.FrameCount

    -- Select in dock node
    -- For #2304 we avoid applying focus immediately before the tabbar is visible.
    -- if (dock_node && dock_node->TabBar)
    --     dock_node->TabBar->SelectedTabId = dock_node->TabBar->NextSelectedTabId = window->TabId;

    -- Bring to front
    ImGui.BringWindowToFocusFront(focus_front_window)
    if bit32.band(bit32.bor(window.Flags, focus_front_window.Flags, display_front_window.Flags), ImGuiWindowFlags.NoBringToFrontOnFocus) == 0 then
        ImGui.BringWindowToDisplayFront(display_front_window)
    end
end

--- @param window ImGuiWindow
--- @return int
function ImGui.FindWindowFocusIndex(window)
    local g = GImGui
    -- IM_UNUSED(g)
    local order = window.FocusOrder
    IM_ASSERT(window.RootWindow == window) -- No child window (not testing _ChildWindow because of docking)
    IM_ASSERT(g.WindowsFocusOrder.Data[order] == window)
    return order
end

-- Can we focus this window with Ctrl+Tab (or PadMenu + PadFocusPrev/PadFocusNext)
-- Note that NoNavFocus makes the window not reachable with Ctrl+Tab but it can still be focused with mouse or programmatically.
-- If you want a window to never be focused, you may use the e.g. NoInputs flag.
--- @param window ImGuiWindow
--- @return bool
function ImGui.IsWindowNavFocusable(window)
    return window.WasActive and window == window.RootWindow and bit32.band(window.Flags, ImGuiWindowFlags.NoNavFocus) == 0
end

--- @param i_start int
--- @param i_stop  int
--- @param dir     int
--- @return ImGuiWindow?
function ImGui.FindWindowNavFocusable(i_start, i_stop, dir) -- FIXME-OPT O(N)
    local g = GImGui
    local i = i_start
    while i >= 1 and i <= g.WindowsFocusOrder.Size and i ~= i_stop do
        local window = g.WindowsFocusOrder.Data[i]
        if ImGui.IsWindowNavFocusable(window) then
            return window
        end
        i = i + dir
    end
    return nil
end

function ImGui.UpdateWindowInFocusOrderList(window, just_created, new_flags)
    local g = GImGui

    local new_is_explicit_child = (bit32.band(new_flags, ImGuiWindowFlags.ChildWindow) ~= 0) and ((bit32.band(new_flags, ImGuiWindowFlags.Popup) == 0) or (bit32.band(new_flags, ImGuiWindowFlags.ChildMenu) ~= 0))
    local child_flag_changed = (new_is_explicit_child ~= window.IsExplicitChild)

    if (just_created or child_flag_changed) and not new_is_explicit_child then
        IM_ASSERT(not g.WindowsFocusOrder:contains(window))
        g.WindowsFocusOrder:push_back(window)
        window.FocusOrder = g.WindowsFocusOrder.Size
    elseif not just_created and child_flag_changed and new_is_explicit_child then
        IM_ASSERT(g.WindowsFocusOrder.Data[window.FocusOrder] == window)

        for n = window.FocusOrder + 1, g.WindowsFocusOrder.Size do
            g.WindowsFocusOrder.Data[n].FocusOrder = g.WindowsFocusOrder.Data[n].FocusOrder - 1
        end

        g.WindowsFocusOrder:erase(window.FocusOrder)
        window.FocusOrder = -1
    end

    window.IsExplicitChild = new_is_explicit_child
end

--- @param window? ImGuiWindow
function ImGui.BringWindowToFocusFront(window)
    local g = GImGui
    IM_ASSERT(window == window.RootWindow)

    local cur_order = window.FocusOrder
    IM_ASSERT(g.WindowsFocusOrder.Data[cur_order] == window)

    if g.WindowsFocusOrder:back() == window then
        return
    end

    local new_order = g.WindowsFocusOrder.Size

    for n = cur_order, new_order - 1 do
        g.WindowsFocusOrder.Data[n] = g.WindowsFocusOrder.Data[n + 1]
        g.WindowsFocusOrder.Data[n].FocusOrder = g.WindowsFocusOrder.Data[n].FocusOrder - 1
        IM_ASSERT(g.WindowsFocusOrder.Data[n].FocusOrder == n)
    end

    g.WindowsFocusOrder.Data[new_order] = window
    window.FocusOrder = new_order
end

-- Note technically focus related but rather adjacent and close to BringWindowToFocusFront()
-- FIXME-FOCUS: Could opt-in/opt-out enable modal check like in FocusWindow().
--- @param window? ImGuiWindow
function ImGui.BringWindowToDisplayFront(window)
    local g = GImGui

    local current_front_window = g.Windows:back()

    if current_front_window == window or current_front_window.RootWindowDockTree == window then -- Cheap early out (could be better)
        return
    end

    for i, this_window in g.Windows:iter() do
        if this_window == window then
            g.Windows:erase(i)
            break
        end
    end

    g.Windows:push_back(window)
end

--- @param window        ImGuiWindow
--- @param behind_window ImGuiWindow
function ImGui.BringWindowToDisplayBehind(window, behind_window)
    IM_ASSERT(window ~= nil and behind_window ~= nil)
    local g = GImGui
    window = window.RootWindow
    behind_window = behind_window.RootWindow
    -- TODO:
end

--- @param under_this_window? ImGuiWindow
--- @param ignore_window?     ImGuiWindow
--- @param filter_viewport?   ImGuiViewport
--- @param flags              ImGuiFocusRequestFlags
function ImGui.FocusTopMostWindowUnderOne(under_this_window, ignore_window, filter_viewport, flags)
    local g = GImGui
    local start_idx = g.WindowsFocusOrder.Size
    if under_this_window ~= nil then
        -- Aim at root window behind us, if we are in a child window that's our own root (see #4640)
        local offset = -1
        while bit32.band(under_this_window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0 do
            under_this_window = under_this_window.ParentWindow
            offset = 0
        end
        --- @cast under_this_window ImGuiWindow
        start_idx = ImGui.FindWindowFocusIndex(under_this_window) + offset
    end
    for i = start_idx, 1, -1 do
        repeat
        -- We may later decide to test for different NoXXXInputs based on the active navigation input (mouse vs nav) but that may feel more confusing to the user.
        local window = g.WindowsFocusOrder.Data[i]
        if window == ignore_window or not window.WasActive then
            break
        end
        if filter_viewport ~= nil and window.Viewport ~= filter_viewport then
            break
        end
        if bit32.band(window.Flags, bit32.bor(ImGuiWindowFlags.NoMouseInputs, ImGuiWindowFlags.NoNavInputs)) ~= bit32.bor(ImGuiWindowFlags.NoMouseInputs, ImGuiWindowFlags.NoNavInputs) then
            -- FIXME-DOCK: When ImGuiFocusRequestFlags.RestoreFocusedChild is set...
            -- This is failing (lagging by one frame) for docked windows.
            -- If A and B are docked into window and B disappear, at the NewFrame() call site window.NavLastChildNavWindow will still point to B.
            -- We might leverage the tab order implicitly stored in window.DockNodeAsHost.TabBar (essentially the 'most_recently_selected_tab' code in tab bar will do that but on next update)
            -- to tell which is the "previous" window. Or we may leverage 'LastFrameFocused/LastFrameJustFocused' and have this function handle child window itself?
            ImGui.FocusWindow(window, flags)
            return
        end

        until true
    end
    ImGui.FocusWindow(nil, flags)
end

--- @param id     ImGuiID
--- @param window ImGuiWindow
function ImGui.SetFocusID(id, window)
    local g = GImGui
    IM_ASSERT(id ~= 0)

    if g.NavWindow ~= window then
        ImGui.SetNavWindow(window)
    end

    -- Assume that SetFocusID() is called in the context where its window.DC.NavLayerCurrent and g.CurrentFocusScopeId are valid.
    -- Note that window may be ~= g.CurrentWindow (e.g. SetFocusID call in InputTextEx for multi-line text)
    local nav_layer = window.DC.NavLayerCurrent
    g.NavId = id
    g.NavLayer = nav_layer
    ImGui.SetNavFocusScope(g.CurrentFocusScopeId)
    window.NavLastIds[nav_layer] = id
    if g.LastItemData.ID == id then
        ImRect_Copy(window.NavRectRel[nav_layer], ImGui.WindowRectAbsToRel(window, g.LastItemData.NavRect))
    end
    g.NavIdItemFlags = (g.LastItemData.ID == id) and g.LastItemData.ItemFlags or ImGuiItemFlags.None
    if id == g.ActiveIdIsAlive then
        g.NavIdIsAlive = true
    end

    if g.ActiveIdSource == ImGuiInputSource.Keyboard or g.ActiveIdSource == ImGuiInputSource.Gamepad then
        g.NavHighlightItemUnderNav = true
    elseif g.IO.ConfigNavCursorVisibleAuto then
        g.NavCursorVisible = false
    end

    -- Clear preferred scoring position (NavMoveRequestApplyResult() will tend to restore it)
    ImGui.NavClearPreferredPosForAxis(ImGuiAxis.X)
    ImGui.NavClearPreferredPosForAxis(ImGuiAxis.Y)
end

-- This is not 100% symmetric with StartMouseMovingWindow().
-- We do NOT clear ActiveID, because:
-- - It would lead to rather confusing recursive code paths. Caller can call ClearActiveID() if desired.
-- - Some code intentionally cancel moving but keep the ActiveID to lock inputs (e.g. code path taken when clicking a disabled item).
function ImGui.StopMouseMovingWindow()
    local g = GImGui
    local window = g.MovingWindow

    -- Ref commits 6b7766817, 36055213c for some partial history on checking if viewport ~= nil.
    if window and window.Viewport then
        -- Try to merge the window back into the main viewport.
        -- This works because MouseViewport should be ~= MovingWindow.Viewport on release (as per code in UpdateViewports)
        if bit32.band(g.ConfigFlagsCurrFrame, ImGuiConfigFlags.ViewportsEnable) ~= 0 then
            ImGui.UpdateTryMergeWindowIntoHostViewport(window.RootWindowDockTree, g.MouseViewport)
        end

        -- Restore the mouse viewport so that we don't hover the viewport _under_ the moved window during the frame we released the mouse button.
        if (not ImGui.IsDragDropPayloadBeingAccepted()) then
            g.MouseViewport = window.Viewport
        end

        -- Clear the NoInputs window flag set by the Viewport system in AddUpdateViewport()
        local window_can_use_inputs = bit32.band(window.Flags, ImGuiWindowFlags.NoMouseInputs) == 0 or bit32.band(window.Flags, ImGuiWindowFlags.NoNavInputs) == 0
        if window_can_use_inputs then
            window.Viewport.Flags = bit32.band(window.Viewport.Flags, bit32.bnot(ImGuiViewportFlags.NoInputs))
        end
    end

    g.MovingWindow = nil
end

--- @param id      ImGuiID
--- @param window? ImGuiWindow
function ImGui.SetActiveID(id, window)
    local g = GImGui

    -- Clear previous active id
    if g.ActiveId ~= 0 then
        -- Store deactivate data
        local deactivated_data = g.DeactivatedItemData
        deactivated_data.ID = g.ActiveId
        deactivated_data.ElapseFrame = (g.LastItemData.ID == g.ActiveId) and g.FrameCount or g.FrameCount + 1 -- FIXME: OK to use LastItemData?
        deactivated_data.HasBeenEditedBefore = g.ActiveIdHasBeenEditedBefore
        deactivated_data.IsAlive = (g.ActiveIdIsAlive == g.ActiveId)

        -- This could be written in a more general way (e.g associate a hook to ActiveId),
        -- but since this is currently quite an exception we'll leave it as is.
        -- One common scenario leading to this is: pressing Key ->NavMoveRequestApplyResult() -> ClearActiveID()
        if g.InputTextState.ID == g.ActiveId then
            ImGui.InputTextDeactivateHook(g.ActiveId)
        end

        -- While most behaved code would make an effort to not steal active id during window move/drag operations,
        -- we at least need to be resilient to it. Canceling the move is rather aggressive and users of 'master' branch
        -- may prefer the weird ill-defined half working situation ('docking' did assert), so may need to rework that.
        if g.MovingWindow and (g.ActiveId == g.MovingWindow.MoveId) then
            print("SetActiveID() cancel MovingWindow")
            ImGui.StopMouseMovingWindow()
        end
    end

    -- Set active id
    g.ActiveIdIsJustActivated = (g.ActiveId ~= id)
    if (g.ActiveIdIsJustActivated) then
        -- IMGUI_DEBUG_LOG_ACTIVEID("SetActiveID() 0x%08X in \"%s\"%*s(previously 0x%08X in \"%s\")\n", id, window ? window->Name : "",
        --     ImMax(0, 20 - (int)(window ? strlen(window->Name) : 0)), "", g.ActiveId, g.ActiveIdWindow ? g.ActiveIdWindow->Name : "");
        g.ActiveIdTimer = 0.0
        g.ActiveIdHasBeenPressedBefore = false
        g.ActiveIdHasBeenEditedBefore = false
        g.ActiveIdMouseButton = -1

        if id ~= 0 then
            g.LastActiveId = id
            g.LastActiveIdTimer = 0.0
        end
    end
    g.ActiveId = id
    g.ActiveIdAllowOverlap = false
    g.ActiveIdNoClearOnFocusLoss = false
    g.ActiveIdWindow = window
    g.ActiveIdHasBeenEditedThisFrame = false
    g.ActiveIdFromShortcut = false
    g.ActiveIdDisabledId = 0
    if id ~= 0 then
        g.ActiveIdIsAlive = id
        if g.NavActivateId == id or g.NavJustMovedToId == id then
            g.ActiveIdSource = g.NavInputSource
        else
            g.ActiveIdSource = ImGuiInputSource.Mouse
        end
        IM_ASSERT(g.ActiveIdSource ~= ImGuiInputSource.None)
    end

    -- Clear declaration of inputs claimed by the widget
    -- (Please note that this is WIP and not all keys/inputs are thoroughly declared by all widgets yet)
    g.ActiveIdUsingNavDirMask = 0x00
    g.ActiveIdUsingAllKeyboardKeys = false
end

function ImGui.ClearActiveID()
    ImGui.SetActiveID(0, nil) -- g.ActiveId = 0
end

-------------------------------------------------------------------------------
-- [SECTION] ID STACK
-------------------------------------------------------------------------------

--- @param str_id string|int

function ImGui.PushID(str_id)
    local g = GImGui
    local window = g.CurrentWindow
    local id = window:GetID(str_id)
    -- [Luau] inline window.IDStack:push_back(id)
    local stack = window.IDStack
    local n = stack.Size + 1
    if n > stack.Capacity then stack:push_back(id) else stack.Data[n] = id; stack.Size = n end
end

-- Push a given id value ignoring the ID stack as a seed.
--- @param id ImGuiID
function ImGui.PushOverrideID(id)
    local g = GImGui
    local window = g.CurrentWindow
    if g.DebugHookIdInfoId == id and id ~= 0 then
        ImGui.DebugHookIdInfo(id, ImGuiDataType.ID, nil)
    end
    -- [Luau] inline window.IDStack:push_back(id)
    local stack = window.IDStack
    local n = stack.Size + 1
    if n > stack.Capacity then stack:push_back(id) else stack.Data[n] = id; stack.Size = n end
end


function ImGui.PopID()
    local window = GImGui.CurrentWindow
    local stack = window.IDStack
    IM_ASSERT_USER_ERROR_RET(stack.Size > 1, "Calling PopID() too many times!")
    stack.Size = stack.Size - 1 -- [Luau] inline stack:pop_back()
end

-- This is one of the very rare legacy case where we use ImGuiWindow methods,
-- it should ideally be flattened at some point but it's been used a lots by widgets.
--- @param id string|int
--- @return ImGuiID

function MT.ImGuiWindow:GetID(id)
    local stack = self.IDStack
    local seed = stack.Data[stack.Size] -- [Luau] inline self.IDStack:back()

    local h
    if type(id) == "string" then
        h = ImHashStr(id, nil, seed)
    else --- @cast id int
        h = ImHashData(id, -1, seed)
    end
    local g = GImGui
    if g.DebugHookIdInfoId == h and h ~= 0 then
        ImGui.DebugHookIdInfo(h, (type(id) == "string") and ImGuiDataType.String or ImGuiDataType.S32, id)
    end
    return h
end

-- This is only used in rare/specific situations to manufacture an ID out of nowhere.
-- FIXME: Consider instead storing last non-zero ID + count of successive zero-ID, and combine those?
--- @param p_abs ImVec2
--- @return ImGuiID
function MT.ImGuiWindow:GetIDFromPos(p_abs)
    local seed = self.IDStack:back()
    local p_rel = ImGui.WindowPosAbsToRel(self, p_abs)
    return ImHashData(p_rel, 2, seed)
end

-- "
--- @param r_abs ImRect
--- @return ImGuiID
function MT.ImGuiWindow:GetIDFromRectangle(r_abs)
    local seed = self.IDStack:back()
    local r_rel = ImGui.WindowRectAbsToRel(self, r_abs)
    return ImHashData({ math.floor(r_rel.Min.x), math.floor(r_rel.Min.y), math.floor(r_rel.Max.x), math.floor(r_rel.Max.y) }, 4, seed)
end

-- Overloads: GetID(str_id) / GetID(str_id_begin, str_id_end) / GetID(int_id)
--- @param str_or_int string|int
--- @param str_end?   int # exclusive end (1-based byte position)
--- @return ImGuiID
function ImGui.GetID(str_or_int, str_end)
    local window = GImGui.CurrentWindow
    if str_end ~= nil and type(str_or_int) == "string" then
        return ImHashStr(str_or_int, str_end - 1, window.IDStack:back())
    end
    return window:GetID(str_or_int)
end

-- Helper to avoid a common series of PushOverrideID -> GetID() -> PopID() call
-- (note that when using this pattern, ID Stack Tool will tend to not display the intermediate stack level.
--  for that to work we would need to do PushOverrideID() -> ItemAdd() -> PopID() which would alter widget code a little more)
-- Overloads: GetIDWithSeed(str, str_end, seed) / GetIDWithSeed(n, seed)
function ImGui.GetIDWithSeed(a, b, c)
    local id
    if type(a) == "number" then
        id = ImHashData(a, -1, b)
    else
        id = ImHashStr(a, b and (b - 1) or nil, c)
    end
    if GImGui.DebugHookIdInfoId == id and id ~= 0 then
        ImGui.DebugHookIdInfo(id, (type(a) == "number") and ImGuiDataType.S32 or ImGuiDataType.String, (b and type(a) == "string") and string.sub(a, 1, b - 1) or a)
    end
    return id
end

--- @param id ImGuiID

function ImGui.SetHoveredID(id)
    local g = GImGui
    g.HoveredId = id
    g.HoveredIdAllowOverlap = false
    if id ~= 0 and g.HoveredIdPreviousFrame ~= id then
        g.HoveredIdTimer = 0.0
        g.HoveredIdNotActiveTimer = 0.0
    end
end

--- @param flags ImGuiHoveredFlags
--- @return float
local function CalcDelayFromHoveredFlags(flags)
    local g = GImGui
    if bit32.band(flags, ImGuiHoveredFlags.DelayNormal) ~= 0 then
        return g.Style.HoverDelayNormal
    end
    if bit32.band(flags, ImGuiHoveredFlags.DelayShort) ~= 0 then
        return g.Style.HoverDelayShort
    end
    return 0.0
end

--- @param user_flags   ImGuiHoveredFlags
--- @param shared_flags ImGuiHoveredFlags
local function ApplyHoverFlagsForTooltip(user_flags, shared_flags)
    -- Allow instance flags to override shared flags
    if bit32.band(user_flags, bit32.bor(ImGuiHoveredFlags.DelayNone, ImGuiHoveredFlags.DelayShort, ImGuiHoveredFlags.DelayNormal)) ~= 0 then
        shared_flags = bit32.band(shared_flags, bit32.bnot(bit32.bor(ImGuiHoveredFlags.DelayNone, ImGuiHoveredFlags.DelayShort, ImGuiHoveredFlags.DelayNormal)))
    end
    return bit32.bor(user_flags, shared_flags)
end

--- @param id ImGuiID
function ImGui.MarkItemEdited(id)
    -- This marking is to be able to provide info for IsItemDeactivatedAfterEdit().
    -- ActiveId might have been released by the time we call this (as in the typical press/release button behavior) but still need to fill the data.
    local g = GImGui

    -- IM_ASSERT(g.LastItemData.ID == id) -- Failing cases include: "widgets_inputtext_scrolling", "widgets_inputtext_multiline_status", "widgets_selectable_input" = case of e.g TempInputText() overlayed manually with different ID (#2718)
    g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.EditedInternal)
    if bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.NoMarkEdited) ~= 0 then
        return
    end
    g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.Edited)

    if g.ActiveId == id or g.ActiveId == 0 then
        -- FIXME: Can't we fully rely on LastItemData yet?
        g.AnyIdHasBeenEditedThisFrame = true
        g.ActiveIdHasBeenEditedThisFrame = true
        g.ActiveIdHasBeenEditedBefore = true
    end
    if g.DeactivatedItemData.ID == id then
        g.DeactivatedItemData.HasBeenEditedBefore = true
    end

    -- We accept a MarkItemEdited() on drag and drop targets (see https://github.com/ocornut/imgui/issues/1875#issuecomment-978243343)
    -- We accept 'ActiveIdPreviousFrame == id' for InputText() returning an edit after it has been taken ActiveId away (#4714)
    -- FIXME: This assert is getting a bit meaningless over time. It helped detect some unusual use cases but eventually it is becoming an unnecessary restriction.
    IM_ASSERT(g.DragDropActive or g.ActiveId == id or g.ActiveId == 0 or g.DeactivatedItemData.ID == id or g.ActiveIdPreviousFrame == id or g.NavJustMovedToId or (g.CurrentMultiSelect ~= nil and g.BoxSelectState.IsActive))

    -- IM_ASSERT(g.CurrentWindow.DC.LastItemId == id)
    g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.Edited)
end

--- @param window ImGuiWindow
--- @param flags  ImGuiHoveredFlags
function ImGui.IsWindowContentHoverable(window, flags)
    -- An active popup disable hovering on other windows (apart from its own children)
    -- FIXME-OPT: This could be cached/stored within the window.
    local g = GImGui
    if g.NavWindow then
        local focused_root_window = g.NavWindow.RootWindowDockTree
        if focused_root_window.WasActive and focused_root_window ~= window.RootWindowDockTree then
            -- For the purpose of those flags we differentiate "standard popup" from "modal popup"
            -- NB: The 'else' is important because Modal windows are also Popups.
            local want_inhibit = false
            if bit32.band(focused_root_window.Flags, ImGuiWindowFlags.Modal) ~= 0 then
                want_inhibit = true
            elseif (bit32.band(focused_root_window.Flags, ImGuiWindowFlags.Popup) ~= 0) and (bit32.band(flags, ImGuiHoveredFlags.AllowWhenBlockedByPopup) == 0) then
                want_inhibit = true
            end

            -- Inhibit hover unless the window is within the stack of our modal/popup
            if want_inhibit then
                if not ImGui.IsWindowWithinBeginStackOf(window.RootWindow, focused_root_window) then
                    return false
                end
            end
        end
    end

    -- Filter by viewport
    if (window.Viewport ~= g.MouseViewport) then
        if (g.MovingWindow == nil or window.RootWindowDockTree ~= g.MovingWindow.RootWindowDockTree) then
            return false
        end
    end

    return true
end

-- This is roughly matching the behavior of internal-facing ItemHoverable()
-- - we allow hovering to be true when ActiveId==window.MoveID, so that clicking on non-interactive items such as a Text() item still returns true with IsItemHovered()
-- - this should work even for non-interactive items that have no ID, so we cannot use LastItemId
--- @param flags? ImGuiHoveredFlags

function ImGui.IsItemHovered(flags)
    if flags == nil then flags = 0 end

    local g = GImGui
    local window = g.CurrentWindow
    IM_ASSERT_USER_ERROR(bit32.band(flags, bit32.bnot(ImGuiHoveredFlags.AllowedMaskForIsItemHovered)) == 0, "Invalid flags for IsItemHovered()!")

    if g.NavHighlightItemUnderNav and g.NavCursorVisible and bit32.band(flags, ImGuiHoveredFlags.NoNavOverride) == 0 then
        if not ImGui.IsItemFocused() then
            return false
        end
        if bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.Disabled) ~= 0 and bit32.band(flags, ImGuiHoveredFlags.AllowWhenDisabled) == 0 then
            return false
        end

        if bit32.band(flags, ImGuiHoveredFlags.ForTooltip) ~= 0 then
            flags = ApplyHoverFlagsForTooltip(flags, g.Style.HoverFlagsForTooltipNav)
        end
    else
        -- Test for bounding box overlap, as updated as ItemAdd()
        local status_flags = g.LastItemData.StatusFlags
        if bit32.band(status_flags, ImGuiItemStatusFlags.HoveredRect) == 0 then
            return false
        end

        if bit32.band(flags, ImGuiHoveredFlags.ForTooltip) ~= 0 then
            flags = ApplyHoverFlagsForTooltip(flags, g.Style.HoverFlagsForTooltipMouse)
        end

        -- Done with rectangle culling so we can perform heavier checks now
        -- Test if we are hovering the right window (our window could be behind another window)
        -- [2021/03/02] Reworked / reverted the revert, finally. Note we want e.g. BeginGroup/ItemAdd/EndGroup to work as well. (#3851)
        -- [2017/10/16] Reverted commit 344d48be3 and testing RootWindow instead. I believe it is correct to NOT test for RootWindow but this leaves us unable
        -- to use IsItemHovered() after EndChild() itself. Until a solution is found I believe reverting to the test from 2017/09/27 is safe since this was
        -- the test that has been running for a long while.
        if g.HoveredWindow ~= window and bit32.band(status_flags, ImGuiItemStatusFlags.HoveredWindow) == 0 then
            if bit32.band(flags, ImGuiHoveredFlags.AllowWhenOverlappedByWindow) == 0 then
                return false
            end
        end

        -- Test if another item is active (e.g. being dragged)
        local id = g.LastItemData.ID
        if bit32.band(flags, ImGuiHoveredFlags.AllowWhenBlockedByActiveItem) == 0 then
            if g.ActiveId ~= 0 and g.ActiveId ~= id and not g.ActiveIdAllowOverlap and not g.ActiveIdFromShortcut then
                -- When ActiveId == MoveId it means that either:
                -- - (1) user clicked on void _or_ an item with no id, which triggers moving window (ActiveId is set even when window has _NoMove flag)
                --   - the (id == 0) test handles it, however, IsItemHovered() will leak between id==0 items (mostly visible when using _NoMove). -- FIXME: May be fixed.
                -- - (2) user clicked a disabled item. UpdateMouseMovingWindowEndFrame() uses ActiveId == MoveId to avoid interference with item logic + sets ActiveIdDisabledId.
                local cancel_is_hovered = true
                if g.ActiveId == window.MoveId and (id == 0 or g.ActiveIdDisabledId == id) then
                    cancel_is_hovered = false
                end
                -- When ActiveId == TabId it means user clicked docking tab for the window.
                if g.ActiveId == window.TabId then
                    cancel_is_hovered = false
                end
                if cancel_is_hovered then
                    return false
                end
            end
        end

        -- Test if interactions on this window are blocked by an active popup or modal.
        -- The ImGuiHoveredFlags.AllowWhenBlockedByPopup flag will be tested here.
        if not ImGui.IsWindowContentHoverable(window, flags) and bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.NoWindowHoverableCheck) == 0 then
            return false
        end

        -- Test if the item is disabled
        if bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.Disabled) ~= 0 and bit32.band(flags, ImGuiHoveredFlags.AllowWhenDisabled) == 0 then
            return false
        end

        -- Special handling for calling after Begin() which represent the title bar or tab.
        -- When the window is skipped/collapsed (SkipItems==true) that last item (always .MoveId submitted by Begin)
        -- will never be overwritten so we need to detect the case.
        if id == window.MoveId and window.WriteAccessed then
            return false
        end

        -- Test if using AllowOverlap and overlapped
        if bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.AllowOverlap) ~= 0 and id ~= 0 then
            if bit32.band(flags, ImGuiHoveredFlags.AllowWhenOverlappedByItem) == 0 then
                if g.HoveredIdPreviousFrame ~= g.LastItemData.ID then
                    return false
                end
            end
        end
    end

    -- Handle hover delay
    -- (some ideas: https://www.nngroup.com/articles/timing-exposing-content)
    local delay = CalcDelayFromHoveredFlags(flags)
    if delay > 0.0 or bit32.band(flags, ImGuiHoveredFlags.Stationary) ~= 0 then
        local hover_delay_id
        if g.LastItemData.ID ~= 0 then
            hover_delay_id = g.LastItemData.ID
        else
            hover_delay_id = window:GetIDFromPos(g.LastItemData.Rect.Min)
        end
        if bit32.band(flags, ImGuiHoveredFlags.NoSharedDelay) ~= 0 and g.HoverItemDelayIdPreviousFrame ~= hover_delay_id then
            g.HoverItemDelayTimer = 0.0
        end
        g.HoverItemDelayId = hover_delay_id

        -- When changing hovered item we requires a bit of stationary delay before activating hover timer,
        -- but once unlocked on a given item we also moving.
        -- if (g.HoverDelayTimer >= delay && (g.HoverDelayTimer - g.IO.DeltaTime < delay || g.MouseStationaryTimer - g.IO.DeltaTime < g.Style.HoverStationaryDelay)) { IMGUI_DEBUG_LOG("HoverDelayTimer = %f/%f, MouseStationaryTimer = %f\n", g.HoverDelayTimer, delay, g.MouseStationaryTimer); }
        if bit32.band(flags, ImGuiHoveredFlags.Stationary) ~= 0 and g.HoverItemUnlockedStationaryId ~= hover_delay_id then
            return false
        end

        if g.HoverItemDelayTimer < delay then
            return false
        end
    end

    return true
end

-- Internal facing ItemHoverable() used when submitting widgets. THIS IS A SUBMISSION NOT A HOVER CHECK.
-- Returns whether the item was hovered, logic differs slightly from IsItemHovered().
-- (this does not rely on LastItemData it can be called from a ButtonBehavior() call not following an ItemAdd() call)
-- FIXME-LEGACY: the 'ImGuiItemFlags item_flags' parameter was added on 2023-06-28.
-- If you used this in your legacy/custom widgets code:
-- - Commonly: if your ItemHoverable() call comes after an ItemAdd() call: pass 'item_flags = g.LastItemData.ItemFlags'.
-- - Rare: otherwise you may pass 'item_flags = 0' (ImGuiItemFlags.None) unless you want to benefit from special behavior handled by ItemHoverable.
--- @param bb         ImRect
--- @param id         ImGuiID
--- @param item_flags ImGuiItemFlags

function ImGui.ItemHoverable(bb, id, item_flags)
    local g = GImGui
    local window = g.CurrentWindow

    -- Detect ID conflicts
    -- (this is specifically done here by comparing on hover because it allows us a detection of duplicates that is algorithmically extra cheap, 1 u32 compare per item. No O(log N) lookup whatsoever)
if not IMGUI_DISABLE_DEBUG_TOOLS then
    if id ~= 0 and g.HoveredIdPreviousFrame == id and bit32.band(item_flags, ImGuiItemFlags.AllowDuplicateId) == 0 then
        g.HoveredIdPreviousFrameItemCount = g.HoveredIdPreviousFrameItemCount + 1
        if g.DebugDrawIdConflictsId == id then
            window.DrawList:AddRect(bb.Min - ImVec2(1, 1), bb.Max + ImVec2(1, 1), IM_COL32(255, 0, 0, 255), 0.0, 2.0, ImDrawFlags.None)
        end
    end
end

    if g.HoveredWindow ~= window then
        return false
    end

    if not ImGui.IsMouseHoveringRect(bb.Min, bb.Max) then
        return false
    end

    if g.HoveredId ~= 0 and g.HoveredId ~= id and not g.HoveredIdAllowOverlap then
        return false
    end

    if g.ActiveId ~= 0 and g.ActiveId ~= id and not g.ActiveIdAllowOverlap then
        if not g.ActiveIdFromShortcut then
            return false
        end
    end

    -- We are done with rectangle culling so we can perform heavier checks now.
    if (bit32.band(item_flags, ImGuiItemFlags.NoWindowHoverableCheck) == 0) and not ImGui.IsWindowContentHoverable(window, ImGuiHoveredFlags.None) then
        g.HoveredIdIsDisabled = true
        return false
    end

    -- We exceptionally allow this function to be called with id==0 to allow using it for easy high-level
    -- hover test in widgets code. We could also decide to split this function is two.
    if id ~= 0 then
        -- Drag source doesn't report as hovered
        if g.DragDropActive and g.DragDropPayload.SourceId == id and (bit32.band(g.DragDropSourceFlags, ImGuiDragDropFlags.SourceNoDisableHover) == 0) then
            return false
        end

        ImGui.SetHoveredID(id)

        -- AllowOverlap mode (rarely used) requires previous frame HoveredId to be nil or to match.
        -- This allows using patterns where a later submitted widget overlaps a previous one. Generally perceived as a front-to-back hit-test.
        if bit32.band(item_flags, ImGuiItemFlags.AllowOverlap) ~= 0 then
            g.HoveredIdAllowOverlap = true
            if g.HoveredIdPreviousFrame ~= id then
                return false
            end
        end

        -- Display shortcut (only works with mouse)
        -- (ImGuiItemStatusFlags.HasShortcut in LastItemData denotes we want a tooltip)
        if id == g.LastItemData.ID and (bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HasShortcut) ~= 0) and g.ActiveId ~= id then
            if ImGui.IsItemHovered(bit32.bor(ImGuiHoveredFlags.ForTooltip, ImGuiHoveredFlags.DelayNormal)) then
                ImGui.SetTooltip("%s", ImGui.GetKeyChordName(g.LastItemData.Shortcut))
            end
        end
    end

    -- When disabled we'll return false but still set HoveredId
    if bit32.band(item_flags, ImGuiItemFlags.Disabled) ~= 0 then
        -- Release active id if turning disabled
        if g.ActiveId == id and id ~= 0 then
            ImGui.ClearActiveID()
        end
        g.HoveredIdIsDisabled = true
        return false
    end

    if g.NavHighlightItemUnderNav and (bit32.band(item_flags, ImGuiItemFlags.NoNavDisableMouseHover) == 0) then
        return false
    end

    return true
end

-- FIXME: This is inlined/duplicated in ItemAdd()
-- FIXME: The id ~= 0 path is not used by our codebase, may get rid of it?
--- @param bb ImRect
--- @param id ImGuiID
--- @return bool
function ImGui.IsClippedEx(bb, id)
    local g = GImGui
    local window = g.CurrentWindow
    -- [Luau] inline bb:Overlaps(window.ClipRect)
    local bmin, bmax, cr = bb.Min, bb.Max, window.ClipRect
    if not (bmin.x <= cr.Max.x and bmax.x >= cr.Min.x and bmin.y <= cr.Max.y and bmax.y >= cr.Min.y) then
        if id == 0 or (id ~= g.ActiveId and id ~= g.ActiveIdPreviousFrame and id ~= g.NavId and id ~= g.NavActivateId) then
            if not g.ItemUnclipByLog then
                return true
            end
        end
    end
    return false
end

-- This is also inlined in ItemAdd()
-- Note: if ImGuiItemStatusFlags.HasDisplayRect is set, user needs to set g.LastItemData.DisplayRect.
--- @param item_id      ImGuiID
--- @param item_flags   ImGuiItemFlags
--- @param status_flags ImGuiItemStatusFlags
--- @param item_rect    ImRect
function ImGui.SetLastItemData(item_id, item_flags, status_flags, item_rect)
    local g = GImGui
    g.LastItemData.ID = item_id
    g.LastItemData.ItemFlags = item_flags
    g.LastItemData.StatusFlags = status_flags
    ImRect_Copy(g.LastItemData.Rect, item_rect)
    ImRect_Copy(g.LastItemData.NavRect, item_rect)
end

--- @param window ImGuiWindow
--- @param rect   ImRect
function ImGui.SetLastItemDataForWindow(window, rect)
    local g = GImGui
    if window.DockIsActive then
        ImGui.SetLastItemData(window.MoveId, g.CurrentItemFlags, window.DC.DockTabItemStatusFlags, window.DC.DockTabItemRect)
    else
        ImGui.SetLastItemData(window.MoveId, g.CurrentItemFlags, window.DC.WindowItemStatusFlags, rect)
    end
end

-- Pass in translated ASCII characters for text input.
-- - with glfw you can get those from the callback set in glfwSetCharCallback()
-- - on Windows you can get those using ToAscii+keyboard state, or via the WM_CHAR message
-- FIXME: Should in theory be called "AddCharacterEvent()" to be consistent with new API
--- @param c unsigned_int
function MT.ImGuiIO:AddInputCharacter(c)
    IM_ASSERT(self.Ctx ~= nil)
    local g = self.Ctx
    if c == 0 or not self.AppAcceptingEvents then
        return
    end

    local e = ImGuiInputEvent()
    e.Type = ImGuiInputEventType.Text
    e.Source = ImGuiInputSource.Keyboard
    e.EventId = g.InputEventsNextEventId
    g.InputEventsNextEventId = g.InputEventsNextEventId + 1
    e.Text = ImGuiInputEventText()
    e.Text.Char = c

    g.InputEventsQueue:push_back(e)
end

-- UTF16 strings use surrogate pairs to encode codepoints >= 0x10000, so
-- we should save the high surrogate.
--- @param c ImWchar16
function MT.ImGuiIO:AddInputCharacterUTF16(c)
    if (c == 0 and self.InputQueueSurrogate == 0) or not self.AppAcceptingEvents then
        return
    end

    if bit32.band(c, 0xFC00) == 0xD800 then -- High surrogate, must save
        if self.InputQueueSurrogate ~= 0 then
            self:AddInputCharacter(IM_UNICODE_CODEPOINT_INVALID)
        end
        self.InputQueueSurrogate = c
        return
    end

    local cp = c
    if self.InputQueueSurrogate ~= 0 then
        if bit32.band(c, 0xFC00) ~= 0xDC00 then -- Invalid low surrogate
            self:AddInputCharacter(IM_UNICODE_CODEPOINT_INVALID)
        else
            -- #if IM_UNICODE_CODEPOINT_MAX == 0xFFFF
            cp = IM_UNICODE_CODEPOINT_INVALID -- Codepoint will not fit in ImWchar
            -- #endif
        end

        self.InputQueueSurrogate = 0
    end
    self:AddInputCharacter(cp)
end

-- Clear all incoming events.
function MT.ImGuiIO:ClearEventsQueue()
    IM_ASSERT(self.Ctx ~= nil)
    local g = GImGui
    g.InputEventsQueue:clear()
end

-- Clear current keyboard/gamepad state + current frame text input buffer. Equivalent to releasing all keys/buttons.
function MT.ImGuiIO:ClearInputKeys()
    local g = self.Ctx
    for key = ImGuiKey.NamedKey_BEGIN, ImGuiKey.NamedKey_END - 1 do
        if not ImGui.IsMouseKey(key) then
            local key_data = g.IO.KeysData[key - ImGuiKey.NamedKey_BEGIN]
            key_data.Down = false
            key_data.DownDuration = -1.0
            key_data.DownDurationPrev = -1.0
        end
    end
    self.KeyCtrl  = false
    self.KeyShift = false
    self.KeyAlt   = false
    self.KeySuper = false
    self.KeyMods  = ImGuiMod_None
    self.InputQueueCharacters:resize(0) -- Behavior of old ClearInputCharacters().
end

function MT.ImGuiIO:ClearInputMouse()
    for key = ImGuiKey_Mouse_BEGIN, ImGuiKey_Mouse_END - 1 do
        local key_data = self.KeysData[key - ImGuiKey.NamedKey_BEGIN]
        if key_data then
            key_data.Down = false
            key_data.DownDuration = -1.0
            key_data.DownDurationPrev = -1.0
        end
    end

    self.MousePos = ImVec2(-FLT_MAX, -FLT_MAX)

    for n = 0, 2 do -- IM_COUNTOF(MouseDown)
        self.MouseDown[n] = false
        self.MouseDownDuration[n] = -1.0
        self.MouseDownDurationPrev[n] = -1.0
    end

    self.MouseWheel = 0
    self.MouseWheelH = 0
end

--- @param ctx  ImGuiContext
--- @param type ImGuiInputEventType
--- @param arg? int
--- @return ImGuiInputEvent?
function MT.ImGuiIO:FindLatestInputEvent(ctx, type, arg)
    if arg == nil then arg = -1 end

    local g = ctx
    for n = g.InputEventsQueue.Size, 1, -1 do
        local e = g.InputEventsQueue.Data[n]

        if e.Type ~= type then
        elseif type == ImGuiInputEventType.Key and e.Key.Key ~= arg then
        elseif type == ImGuiInputEventType.MouseButton and e.MouseButton.Button ~= arg then
        else
            return e
        end
    end

    return nil
end

-- Queue a new key down/up event.
-- - ImGuiKey key:       Translated key (as in, generally ImGuiKey.A matches the key end-user would use to emit an 'A' character)
-- - bool down:          Is the key down? use false to signify a key release.
-- - float analog_value: 0.0f..1.0f
-- IMPORTANT: THIS FUNCTION AND OTHER "ADD" GRABS THE CONTEXT FROM OUR INSTANCE.
-- WE NEED TO ENSURE THAT ALL FUNCTION CALLS ARE FULFILLING THIS, WHICH IS WHY GetKeyData() HAS AN EXPLICIT CONTEXT.
--- @param key          ImGuiKey
--- @param down         bool
--- @param analog_value float
function MT.ImGuiIO:AddKeyAnalogEvent(key, down, analog_value)
    -- if (e->Down) { IMGUI_DEBUG_LOG_IO("AddKeyEvent() Key='%s' %d, NativeKeycode = %d, NativeScancode = %d\n", ImGui::GetKeyName(e->Key), e->Down, e->NativeKeycode, e->NativeScancode); }
    IM_ASSERT(self.Ctx ~= nil)
    if key == ImGuiKey.None or not self.AppAcceptingEvents then
        return
    end

    local g = self.Ctx
    IM_ASSERT(ImGui.IsNamedKeyOrMod(key)) -- Backend needs to pass a valid ImGuiKey constant. 0..511 values are legacy native key codes which are not accepted by this API.
    IM_ASSERT(ImGui.IsAliasKey(key) == false) -- Backend cannot submit ImGuiKey.MouseXXX values they are automatically inferred from AddMouseXXX() events.

    -- MacOS: swap Cmd(Super) and Ctrl
    if (g.IO.ConfigMacOSXBehaviors) then
        if (key == ImGuiMod_Super)          then key = ImGuiMod_Ctrl
        elseif (key == ImGuiMod_Ctrl)       then key = ImGuiMod_Super
        elseif (key == ImGuiKey.LeftSuper)  then key = ImGuiKey.LeftCtrl
        elseif (key == ImGuiKey.RightSuper) then key = ImGuiKey.RightCtrl
        elseif (key == ImGuiKey.LeftCtrl)   then key = ImGuiKey.LeftSuper
        elseif (key == ImGuiKey.RightCtrl)  then key = ImGuiKey.RightSuper
        end
    end

    -- Filter duplicate (in particular: key mods and gamepad analog values are commonly spammed)
    local latest_event = self:FindLatestInputEvent(g, ImGuiInputEventType.Key, key)
    local key_data = ImGui.GetKeyData(g, key)
    local latest_key_down = latest_event and latest_event.Key.Down or key_data.Down
    local latest_key_analog = latest_event and latest_event.Key.AnalogValue or key_data.AnalogValue
    if latest_key_down == down and latest_key_analog == analog_value then
        return
    end

    -- Add event
    local e = ImGuiInputEvent()
    e.Type = ImGuiInputEventType.Key
    e.Source = ImGui.IsGamepadKey(key) and ImGuiInputSource.Gamepad or ImGuiInputSource.Keyboard
    e.EventId = g.InputEventsNextEventId
    g.InputEventsNextEventId = g.InputEventsNextEventId + 1
    e.Key = ImGuiInputEventKey()
    e.Key.Key = key
    e.Key.Down = down
    e.Key.AnalogValue = analog_value
    g.InputEventsQueue:push_back(e)
end

--- @param key  ImGuiKey
--- @param down bool
function MT.ImGuiIO:AddKeyEvent(key, down)
    if not self.AppAcceptingEvents then
        return
    end
    self:AddKeyAnalogEvent(key, down, (down and 1.0 or 0.0))
end

-- Set master flag for accepting key/mouse/text events (default to true). Useful if you have native dialog boxes that are interrupting your application loop/refresh, and you want to disable events being queued while your app is frozen.
--- @param accepting_events bool
function MT.ImGuiIO:SetAppAcceptingEvents(accepting_events)
    self.AppAcceptingEvents = accepting_events
end

-- This is not a real event, the data is latched in order to be stored in actual Mouse events.
-- This is so that duplicate events (e.g. Windows sending extraneous WM_MOUSEMOVE) gets filtered and are not leading to actual source changes.
--- @param source ImGuiMouseSource
function MT.ImGuiIO:AddMouseSourceEvent(source)
    IM_ASSERT(self.Ctx ~= nil)
    local g = self.Ctx
    g.InputEventsNextMouseSource = source
end

--- @param viewport_id ImGuiID
function MT.ImGuiIO:AddMouseViewportEvent(viewport_id)
    IM_ASSERT(self.Ctx ~= nil)
    local g = self.Ctx
    -- IM_ASSERT(g.IO.BackendFlags & ImGuiBackendFlags.HasMouseHoveredViewport)
    if (not self.AppAcceptingEvents) then
        return
    end

    -- Filter duplicate
    local latest_event = self:FindLatestInputEvent(g, ImGuiInputEventType.MouseViewport)
    local latest_viewport_id
    if latest_event then
        latest_viewport_id = latest_event.MouseViewport.HoveredViewportID
    else
        latest_viewport_id = g.IO.MouseHoveredViewport
    end
    if (latest_viewport_id == viewport_id) then
        return
    end

    local e = ImGuiInputEvent()
    e.Type = ImGuiInputEventType.MouseViewport
    e.Source = ImGuiInputSource.Mouse
    e.MouseViewport = ImGuiInputEventMouseViewport()
    e.MouseViewport.HoveredViewportID = viewport_id
    g.InputEventsQueue:push_back(e)
end

--- @param focused bool
function MT.ImGuiIO:AddFocusEvent(focused)
    IM_ASSERT(self.Ctx ~= nil)
    local g = self.Ctx

    -- Filter duplicate
    local latest_event = self:FindLatestInputEvent(g, ImGuiInputEventType.Focus)
    local latest_focused = latest_event and latest_event.AppFocused.Focused or (not g.IO.AppFocusLost)
    if latest_focused == focused or (self.ConfigDebugIgnoreFocusLoss and not focused) then
        return
    end

    local e = ImGuiInputEvent()
    e.Type = ImGuiInputEventType.Focus
    e.EventId = g.InputEventsNextEventId
    g.InputEventsNextEventId = g.InputEventsNextEventId + 1
    e.AppFocused = ImGuiInputEventAppFocused()
    e.AppFocused.Focused = focused
    g.InputEventsQueue:push_back(e)
end

-- Queue a mouse move event
--- @param x float
--- @param y float
function MT.ImGuiIO:AddMousePosEvent(x, y)
    IM_ASSERT(self.Ctx ~= nil)
    if not self.AppAcceptingEvents then
        return
    end

    local g = self.Ctx

    -- Apply same flooring as UpdateMouseInputs()
    local x_val = x
    if x > -FLT_MAX then
        x_val = ImFloor(x)
    end
    local y_val = y
    if y > -FLT_MAX then
        y_val = ImFloor(y)
    end

    -- Filter duplicate
    local latest_event = self:FindLatestInputEvent(g, ImGuiInputEventType.MousePos)
    local latest_pos = latest_event and ImVec2(latest_event.MousePos.PosX, latest_event.MousePos.PosY) or self.MousePos
    if latest_pos.x == x_val and latest_pos.y == y_val then
        return
    end

    local e = ImGuiInputEvent()
    e.Type = ImGuiInputEventType.MousePos
    e.Source = ImGuiInputSource.Mouse
    e.EventId = g.InputEventsNextEventId
    g.InputEventsNextEventId = g.InputEventsNextEventId + 1
    e.MousePos = ImGuiInputEventMousePos()
    e.MousePos.PosX = x_val
    e.MousePos.PosY = y_val
    e.MousePos.MouseSource = g.InputEventsNextMouseSource
    g.InputEventsQueue:push_back(e)
end

--- @param mouse_button ImGuiMouseButton
--- @param down         bool
function MT.ImGuiIO:AddMouseButtonEvent(mouse_button, down)
    IM_ASSERT(self.Ctx ~= nil)
    local g = self.Ctx
    IM_ASSERT(mouse_button >= 0 and mouse_button < ImGuiMouseButton.COUNT)
    if not self.AppAcceptingEvents then
        return
    end

    -- On MacOS X: Convert Ctrl(Super)+Left click into Right-click: handle held button.
    if self.ConfigMacOSXBehaviors and mouse_button == 0 and g.IO.MouseCtrlLeftAsRightClick then
        -- Order of both statements matters: this event will still release mouse button 1
        mouse_button = 1
        if not down then
            self.MouseCtrlLeftAsRightClick = false
        end
    end

    -- Filter duplicate
    local latest_event = self:FindLatestInputEvent(g, ImGuiInputEventType.MouseButton, mouse_button)
    local latest_button_down = latest_event and latest_event.MouseButton.Down or self.MouseDown[mouse_button]
    if latest_button_down == down then
        return
    end

    -- On MacOS X: Convert Ctrl(Super)+Left click into Right-click.
    -- - Note that this is actual physical Ctrl which is ImGuiMod_Super for us.
    -- - At this point we want from !down to down, so this is handling the initial press.
    if self.ConfigMacOSXBehaviors and mouse_button == 0 and down then
        local latest_super_event = self:FindLatestInputEvent(g, ImGuiInputEventType.Key, ImGuiMod_Super)
        if latest_super_event and latest_super_event.Key.Down or self.KeySuper then
            -- IMGUI_DEBUG_LOG_IO("[io] Super+Left Click aliased into Right Click\n")
            self.MouseCtrlLeftAsRightClick = true
            self:AddMouseButtonEvent(1, true) -- This is just quicker to write that passing through, as we need to filter duplicate again.
            return
        end
    end

    local e = ImGuiInputEvent()
    e.Type = ImGuiInputEventType.MouseButton
    e.Source = ImGuiInputSource.Mouse
    e.EventId = g.InputEventsNextEventId
    g.InputEventsNextEventId = g.InputEventsNextEventId + 1
    e.MouseButton = ImGuiInputEventMouseButton()
    e.MouseButton.Button = mouse_button
    e.MouseButton.Down = down
    e.MouseButton.MouseSource = g.InputEventsNextMouseSource
    g.InputEventsQueue:push_back(e)
end

-- Queue a mouse wheel event (some mouse/API may only have a Y component)
--- @param wheel_x float
--- @param wheel_y float
function MT.ImGuiIO:AddMouseWheelEvent(wheel_x, wheel_y)
    IM_ASSERT(self.Ctx ~= nil)
    local g = self.Ctx
    -- Filter duplicate (unlike most events, wheel values are relative and easy to filter)
    if not self.AppAcceptingEvents or (wheel_x == 0 and wheel_y == 0) then
        return
    end

    local e = ImGuiInputEvent()
    e.Type = ImGuiInputEventType.MouseWheel
    e.Source = ImGuiInputSource.Mouse
    e.EventId = g.InputEventsNextEventId
    g.InputEventsNextEventId = g.InputEventsNextEventId + 1
    e.MouseWheel = ImGuiInputEventMouseWheel()
    e.MouseWheel.WheelX = wheel_x
    e.MouseWheel.WheelY = wheel_y
    e.MouseWheel.MouseSource = g.InputEventsNextMouseSource
    g.InputEventsQueue:push_back(e)
end

-------------------------------------------------------------------------------
-- [SECTION] INPUTS
-------------------------------------------------------------------------------
-- - GetModForLRModKey() [Internal]
-- - FixupKeyChord() [Internal]
-- - GetKeyData() [Internal]
-- - GetKeyIndex() [Internal]
-- - GetKeyName()
-- - GetKeyChordName() [Internal]
-- - CalcTypematicRepeatAmount() [Internal]
-- - GetTypematicRepeatRate() [Internal]
-- - GetKeyPressedAmount() [Internal]
-- - GetKeyMagnitude2d() [Internal]
-------------------------------------------------------------------------------
-- - UpdateKeyRoutingTable() [Internal]
-- - GetRoutingIdFromOwnerId() [Internal]
-- - GetShortcutRoutingData() [Internal]
-- - CalcRoutingScore() [Internal]
-- - SetShortcutRouting() [Internal]
-- - TestShortcutRouting() [Internal]
-------------------------------------------------------------------------------
-- - IsKeyDown()
-- - IsKeyPressed()
-- - IsKeyReleased()
-------------------------------------------------------------------------------
-- - IsMouseDown()
-- - IsMouseClicked()
-- - IsMouseReleased()
-- - IsMouseDoubleClicked()
-- - GetMouseClickedCount()
-- - GetItemClickedCountWithSingleClickDelay()
-- - IsMouseHoveringRect() [Internal]
-- - IsMouseDragPastThreshold() [Internal]
-- - IsMouseDragging()
-- - GetMousePos()
-- - SetMousePos() [Internal]
-- - GetMousePosOnOpeningCurrentPopup()
-- - IsMousePosValid()
-- - IsAnyMouseDown()
-- - GetMouseDragDelta()
-- - ResetMouseDragDelta()
-- - GetMouseCursor()
-- - SetMouseCursor()
-------------------------------------------------------------------------------
-- - UpdateAliasKey()
-- - GetMergedModsFromKeys()
-- - UpdateKeyboardInputs()
-- - UpdateMouseInputs()
-------------------------------------------------------------------------------
-- - LockWheelingWindow [Internal]
-- - FindBestWheelingWindow [Internal]
-- - UpdateMouseWheel() [Internal]
-------------------------------------------------------------------------------
-- - SetNextFrameWantCaptureKeyboard()
-- - SetNextFrameWantCaptureMouse()
-------------------------------------------------------------------------------
-- - GetInputSourceName() [Internal]
-- - DebugPrintInputEvent() [Internal]
-- - UpdateInputEvents() [Internal]
-------------------------------------------------------------------------------
-- - GetKeyOwner() [Internal]
-- - TestKeyOwner() [Internal]
-- - SetKeyOwner() [Internal]
-- - SetItemKeyOwner() [Internal]
-- - Shortcut() [Internal]
-------------------------------------------------------------------------------

--- @param key ImGuiKey
local function GetModForLRModKey(key)
    if key == ImGuiKey.LeftCtrl or key == ImGuiKey.RightCtrl then
        return ImGuiMod_Ctrl
    end
    if key == ImGuiKey.LeftShift or key == ImGuiKey.RightShift then
        return ImGuiMod_Shift
    end
    if key == ImGuiKey.LeftAlt or key == ImGuiKey.RightAlt then
        return ImGuiMod_Alt
    end
    if key == ImGuiKey.LeftSuper or key == ImGuiKey.RightSuper then
        return ImGuiMod_Super
    end
    return ImGuiMod_None
end

--- @param key_chord ImGuiKeyChord
function ImGui.FixupKeyChord(key_chord)
    -- Add ImGuiMod_XXXX when a corresponding ImGuiKey.LeftXXX/ImGuiKey.RightXXX is specified.
    local key = bit32.band(key_chord, bit32.bnot(ImGuiMod_Mask_))
    if ImGui.IsLRModKey(key) then
        key_chord = bit32.bor(key_chord, GetModForLRModKey(key))
    end
    return key_chord
end

--- @param ctx? ImGuiContext
--- @param key  ImGuiKey
--- @return ImGuiKeyData, int
function ImGui.GetKeyData(ctx, key)
    if ctx == nil then ctx = GImGui end

    -- Special storage location for mods
    if bit32.band(key, ImGuiMod_Mask_) ~= 0 then
        key = ImGui.ConvertSingleModFlagToKey(key)
    end

    IM_ASSERT(ImGui.IsNamedKey(key), "Support for user key indices was dropped in favor of ImGuiKey. Please update backend & user code.")
    local idx = key - ImGuiKey.NamedKey_BEGIN
    return ctx.IO.KeysData[idx], idx
end

-- Return 2D vector representing the combination of four cardinal direction, with analog value support (for e.g. ImGuiKey.GamepadLStick* values).
--- @param key_left  ImGuiKey
--- @param key_right ImGuiKey
--- @param key_up    ImGuiKey
--- @param key_down  ImGuiKey
function ImGui.GetKeyMagnitude2d(key_left, key_right, key_up, key_down)
    return ImVec2(
        ImGui.GetKeyData(nil, key_right).AnalogValue - ImGui.GetKeyData(nil, key_left).AnalogValue,
        ImGui.GetKeyData(nil, key_down).AnalogValue - ImGui.GetKeyData(nil, key_up).AnalogValue
    )
end

-- TestKeyOwner(..., ID)   : (owner == None || owner == ID)
-- TestKeyOwner(..., None) : (owner == None)
-- TestKeyOwner(..., Any)  : no owner test
-- All paths are also testing for key not being locked, for the rare cases that key have been locked with using ImGuiInputFlags.LockXXX flags.
--- @param key      ImGuiKey
--- @param owner_id ImGuiID
function ImGui.TestKeyOwner(key, owner_id)
    if not ImGui.IsNamedKeyOrMod(key) then
        return true
    end

    local g = GImGui --- @cast g ImGuiContext
    if g.ActiveIdUsingAllKeyboardKeys and owner_id ~= g.ActiveId and owner_id ~= ImGuiKeyOwner_Any then
        if key >= ImGuiKey_Keyboard_BEGIN and key < ImGuiKey_Keyboard_END then
            return false
        end
    end

    local owner_data = ImGui.GetKeyOwnerData(g, key)
    if owner_id == ImGuiKeyOwner_Any then
        return not owner_data.LockThisFrame
    end

    -- Note: SetKeyOwner() sets OwnerCurr. It is not strictly required for most mouse routing overlap (because of ActiveId/HoveredId
    -- are acting as filter before this has a chance to filter), but sane as soon as user tries to look into things.
    -- Setting OwnerCurr in SetKeyOwner() is more consistent than testing OwnerNext here: would be inconsistent with getter and other functions.
    if owner_data.OwnerCurr ~= owner_id then
        if owner_data.LockThisFrame then
            return false
        end
        if owner_data.OwnerCurr ~= ImGuiKeyOwner_NoOwner then
            return false
        end
    end

    return true
end

-- Note that Dear ImGui doesn't know the meaning/semantic of ImGuiKey from 0..511: they are legacy native keycodes.
-- Consider transitioning from 'IsKeyDown(MY_ENGINE_KEY_A)' (<1.87) to IsKeyDown(ImGuiKey.A) (>= 1.87)
--- @param key       ImGuiKey
--- @param owner_id? ImGuiID
function ImGui.IsKeyDown(key, owner_id)
    if owner_id == nil then owner_id = ImGuiKeyOwner_Any end

    local key_data = ImGui.GetKeyData(nil, key)
    if not key_data.Down then
        return false
    end
    if not ImGui.TestKeyOwner(key, owner_id) then
        return false
    end
    return true
end

--- @param key        ImGuiKey
--- @param is_repeat? bool
function ImGui.IsKeyPressed(key, is_repeat)
    if is_repeat == nil then is_repeat = true end

    return ImGui.IsKeyPressedEx(key, is_repeat and ImGuiInputFlags.Repeat or ImGuiInputFlags.None, ImGuiKeyOwner_Any)
end

--- @param key       ImGuiKey
--- @param owner_id? ImGuiID
--- @return bool
function ImGui.IsKeyReleased(key, owner_id)
    if owner_id == nil then owner_id = ImGuiKeyOwner_Any end

    local key_data = ImGui.GetKeyData(nil, key)
    if key_data.DownDurationPrev < 0.0 or key_data.Down then
        return false
    end
    if not ImGui.TestKeyOwner(key, owner_id) then
        return false
    end
    return true
end

-- Important: unlike legacy IsKeyPressed(ImGuiKey, bool repeat=true) which DEFAULT to repeat, this requires EXPLICIT repeat.
--- @param key       ImGuiKey
--- @param flags     ImGuiInputFlags
--- @param owner_id? ImGuiID
function ImGui.IsKeyPressedEx(key, flags, owner_id)
    if owner_id == nil then owner_id = 0 end

    local g = GImGui
    local key_data = ImGui.GetKeyData(g, key)

    if not key_data.Down then -- In theory this should already be encoded as (DownDuration < 0.0f), but testing this facilitates eating mechanism (until we finish work on key ownership)
        return false
    end
    local t = key_data.DownDuration
    if t < 0.0 then
        return false
    end
    IM_ASSERT(bit32.band(flags, bit32.bnot(ImGuiInputFlags.SupportedByIsKeyPressed)) == 0) -- Passing flags not supported by this function!
    if bit32.band(flags, bit32.bor(ImGuiInputFlags.RepeatRateMask_, ImGuiInputFlags.RepeatUntilMask_)) ~= 0 then -- Setting any _RepeatXXX option enables _Repeat
        flags = bit32.bor(flags, ImGuiInputFlags.Repeat)
    end

    local pressed = (t == 0.0)
    if not pressed and bit32.band(flags, ImGuiInputFlags.Repeat) ~= 0 then
        local repeat_delay, repeat_rate = ImGui.GetTypematicRepeatRate(flags)
        pressed = (t > repeat_delay) and (ImGui.GetKeyPressedAmount(key, repeat_delay, repeat_rate) > 0)
        if pressed and bit32.band(flags, ImGuiInputFlags.RepeatUntilMask_) ~= 0 then
            -- Slightly bias 'key_pressed_time' as DownDuration is an accumulation of DeltaTime which we compare to an absolute time value.
            -- Ideally we'd replace DownDuration with KeyPressedTime but it would break user's code.
            local key_pressed_time = g.Time - t + 0.00001
            if bit32.band(flags, ImGuiInputFlags.RepeatUntilKeyModsChange) ~= 0 and g.LastKeyModsChangeTime > key_pressed_time then
                pressed = false
            end
            if bit32.band(flags, ImGuiInputFlags.RepeatUntilKeyModsChangeFromNone) ~= 0 and g.LastKeyModsChangeFromNoneTime > key_pressed_time then
                pressed = false
            end
            if bit32.band(flags, ImGuiInputFlags.RepeatUntilOtherKeyPress) ~= 0 and g.LastKeyboardKeyPressTime > key_pressed_time then
                pressed = false
            end
        end
    end

    if not pressed then
        return false
    end
    if not ImGui.TestKeyOwner(key, owner_id) then
        return false
    end

    return true
end

-- TODO:
-- Return untranslated names: on macOS, Cmd key will show as Ctrl, Ctrl key will show as super.
function ImGui.GetKeyChordName(key_chord)
    local key = bit32.band(key_chord, bit32.bnot(ImGuiMod_Mask_))
    if ImGui.IsLRModKey(key) then
        key_chord = bit32.band(key_chord, bit32.bnot(GetModForLRModKey(key))) -- Return "Ctrl+LeftShift" instead of "Ctrl+Shift+LeftShift"
    end
    local s = ((bit32.band(key_chord, ImGuiMod_Ctrl) ~= 0) and "Ctrl+" or "")
        .. ((bit32.band(key_chord, ImGuiMod_Shift) ~= 0) and "Shift+" or "")
        .. ((bit32.band(key_chord, ImGuiMod_Alt) ~= 0) and "Alt+" or "")
        .. ((bit32.band(key_chord, ImGuiMod_Super) ~= 0) and "Super+" or "")
        .. ((key ~= ImGuiKey.None or key_chord == ImGuiKey.None) and ImGui.GetKeyName(key) or "")
    if key == ImGuiKey.None and key_chord ~= 0 and #s > 0 then
        s = string.sub(s, 1, #s - 1) -- Remove trailing '+'
    end
    return s
end

-- Those names are provided for debugging purpose and are not meant to be saved persistently nor compared.
local GKeyNames = {
    "Tab", "LeftArrow", "RightArrow", "UpArrow", "DownArrow", "PageUp", "PageDown",
    "Home", "End", "Insert", "Delete", "Backspace", "Space", "Enter", "Escape",
    "LeftCtrl", "LeftShift", "LeftAlt", "LeftSuper", "RightCtrl", "RightShift", "RightAlt", "RightSuper", "Menu",
    "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F", "G", "H",
    "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z",
    "F1", "F2", "F3", "F4", "F5", "F6", "F7", "F8", "F9", "F10", "F11", "F12",
    "F13", "F14", "F15", "F16", "F17", "F18", "F19", "F20", "F21", "F22", "F23", "F24",
    "Apostrophe", "Comma", "Minus", "Period", "Slash", "Semicolon", "Equal", "LeftBracket",
    "Backslash", "RightBracket", "GraveAccent", "CapsLock", "ScrollLock", "NumLock", "PrintScreen",
    "Pause", "Keypad0", "Keypad1", "Keypad2", "Keypad3", "Keypad4", "Keypad5", "Keypad6",
    "Keypad7", "Keypad8", "Keypad9", "KeypadDecimal", "KeypadDivide", "KeypadMultiply",
    "KeypadSubtract", "KeypadAdd", "KeypadEnter", "KeypadEqual",
    "AppBack", "AppForward", "Oem102",
    "GamepadStart", "GamepadBack",
    "GamepadFaceLeft", "GamepadFaceRight", "GamepadFaceUp", "GamepadFaceDown",
    "GamepadDpadLeft", "GamepadDpadRight", "GamepadDpadUp", "GamepadDpadDown",
    "GamepadL1", "GamepadR1", "GamepadL2", "GamepadR2", "GamepadL3", "GamepadR3",
    "GamepadLStickLeft", "GamepadLStickRight", "GamepadLStickUp", "GamepadLStickDown",
    "GamepadRStickLeft", "GamepadRStickRight", "GamepadRStickUp", "GamepadRStickDown",
    "MouseLeft", "MouseRight", "MouseMiddle", "MouseX1", "MouseX2", "MouseWheelX", "MouseWheelY",
    "ModCtrl", "ModShift", "ModAlt", "ModSuper", -- ReservedForModXXX are showing the ModXXX names.
}

--- @param key ImGuiKey
--- @return string
function ImGui.GetKeyName(key)
    if key == ImGuiKey.None then
        return "None"
    end
    IM_ASSERT(ImGui.IsNamedKeyOrMod(key), "Support for user key indices was dropped in favor of ImGuiKey. Please update backend and user code.")
    if bit32.band(key, ImGuiMod_Mask_) ~= 0 then
        key = ImGui.ConvertSingleModFlagToKey(key)
    end
    if not ImGui.IsNamedKey(key) then
        return "Unknown"
    end
    return GKeyNames[key - ImGuiKey.NamedKey_BEGIN + 1] or "Unknown"
end

--- @param key ImGuiKey
--- @return ImGuiID
function ImGui.GetKeyOwner(key)
    if not ImGui.IsNamedKeyOrMod(key) then
        return ImGuiKeyOwner_NoOwner
    end

    local g = GImGui
    local owner_data = ImGui.GetKeyOwnerData(g, key)
    local owner_id = owner_data.OwnerCurr

    if g.ActiveIdUsingAllKeyboardKeys and owner_id ~= g.ActiveId and owner_id ~= ImGuiKeyOwner_Any then
        if key >= ImGuiKey_Keyboard_BEGIN and key < ImGuiKey_Keyboard_END then
            return ImGuiKeyOwner_NoOwner
        end
    end

    return owner_id
end

-- t0 = previous time (e.g.: g.Time - g.IO.DeltaTime)
-- t1 = current time (e.g.: g.Time)
-- An event is triggered at:
--  t = 0.0f     t = repeat_delay,    t = repeat_delay + repeat_rate*N
--- @param t0           float
--- @param t1           float
--- @param repeat_delay float
--- @param repeat_rate  float
function ImGui.CalcTypematicRepeatAmount(t0, t1, repeat_delay, repeat_rate)
    if t1 == 0.0 then return 1 end
    if t0 >= t1 then return 0 end
    if repeat_rate <= 0.0 then
        if t0 < repeat_delay and t1 >= repeat_delay then
            return 1
        else
            return 0
        end
    end

    local count_t0
    if t0 < repeat_delay then
        count_t0 = -1
    else
        count_t0 = math.floor((t0 - repeat_delay) / repeat_rate)
    end

    local count_t1
    if t1 < repeat_delay then
        count_t1 = -1
    else
        count_t1 = math.floor((t1 - repeat_delay) / repeat_rate)
    end

    return count_t1 - count_t0
end

--- @param flags        ImGuiInputFlags
--- @return float repeat_delay
--- @return float repeat_rate
function ImGui.GetTypematicRepeatRate(flags)
    local g = GImGui
    flags = bit32.band(flags, ImGuiInputFlags.RepeatRateMask_)
    if     flags == ImGuiInputFlags.RepeatRateNavMove  then repeat_delay = g.IO.KeyRepeatDelay * 0.72; repeat_rate = g.IO.KeyRepeatRate * 0.80; return repeat_delay, repeat_rate
    elseif flags == ImGuiInputFlags.RepeatRateNavTweak then repeat_delay = g.IO.KeyRepeatDelay * 0.72; repeat_rate = g.IO.KeyRepeatRate * 0.30; return repeat_delay, repeat_rate
    else                                                    repeat_delay = g.IO.KeyRepeatDelay * 1.00; repeat_rate = g.IO.KeyRepeatRate * 1.00; return repeat_delay, repeat_rate end
end

-- Return value representing the number of presses in the last time period, for the given repeat rate
-- (most often returns 0 or 1. The result is generally only >1 when RepeatRate is smaller than DeltaTime, aka large DeltaTime or fast RepeatRate)
--- @param key          ImGuiKey
--- @param repeat_delay float
--- @param repeat_rate  float
function ImGui.GetKeyPressedAmount(key, repeat_delay, repeat_rate)
    local g = GImGui
    local key_data = ImGui.GetKeyData(g, key)
    if not key_data.Down then -- In theory this should already be encoded as (DownDuration < 0.0f), but testing this facilitates eating mechanism (until we finish work on key ownership)
        return 0
    end
    local t = key_data.DownDuration
    return ImGui.CalcTypematicRepeatAmount(t - g.IO.DeltaTime, t, repeat_delay, repeat_rate)
end

-- Rewrite routing data buffers to strip old entries + sort by key to make queries not touch scattered data.
--   Entries   D,A,B,B,A,C,B     --> A,A,B,B,B,C,D
--   Index     A:1 B:2 C:5 D:0   --> A:0 B:2 C:5 D:6
-- See 'Metrics->Key Owners & Shortcut Routing' to visualize the result of that operation.
--- @param rt ImGuiKeyRoutingTable
function ImGui.UpdateKeyRoutingTable(rt)
    local g = GImGui --[[@as ImGuiContext]]
    rt.EntriesNext:resize(0)
    for key = ImGuiKey.NamedKey_BEGIN, ImGuiKey.NamedKey_END - 1 do
        local new_routing_start_idx = rt.EntriesNext.Size + 1
        local routing_entry
        local old_routing_idx = rt.Index[key - ImGuiKey.NamedKey_BEGIN + 1]
        while old_routing_idx ~= -1 do
            repeat
            routing_entry = rt.Entries[old_routing_idx]
            routing_entry.RoutingCurrScore = routing_entry.RoutingNextScore
            routing_entry.RoutingCurr = routing_entry.RoutingNext -- Update entry
            routing_entry.RoutingNext = ImGuiKeyOwner_NoOwner
            routing_entry.RoutingNextScore = 0
            if routing_entry.RoutingCurr == ImGuiKeyOwner_NoOwner then
                break
            end

            rt.EntriesNext:push_back(routing_entry) -- Write alive ones into new buffer

            -- Apply routing to owner if there's no owner already (RoutingCurr == None at this point)
            -- This is the result of previous frame's SetShortcutRouting() call.
            if routing_entry.Mods == g.IO.KeyMods then
                local owner_data = ImGui.GetKeyOwnerData(g, key)
                if owner_data.OwnerCurr == ImGuiKeyOwner_NoOwner then
                    owner_data.OwnerCurr = routing_entry.RoutingCurr
                    -- IMGUI_DEBUG_LOG("SetKeyOwner(%s, owner_id=0x%08X) via Routing\n", GetKeyName(key), routing_entry->RoutingCurr);
                end
            end

            until true

            old_routing_idx = routing_entry.NextEntryIndex
        end

        -- Rewrite linked-list
        rt.Index[key - ImGuiKey.NamedKey_BEGIN + 1] = (new_routing_start_idx <= rt.EntriesNext.Size and new_routing_start_idx or -1)
        for n = new_routing_start_idx, rt.EntriesNext.Size do
            rt.EntriesNext[n].NextEntryIndex = (n + 1 <= rt.EntriesNext.Size) and (n + 1) or -1
        end
    end
    rt.Entries:swap(rt.EntriesNext) -- Swap new and old indexes
end

-- owner_id may be None/Any, but routing_id needs to be always be set, so we default to GetCurrentFocusScope().
--- @param owner_id ImGuiID
local function GetRoutingIdFromOwnerId(owner_id)
    local g = GImGui
    return (owner_id ~= ImGuiKeyOwner_NoOwner and owner_id ~= ImGuiKeyOwner_Any) and owner_id or g.CurrentFocusScopeId
end

--- @param key_chord ImGuiKeyChord
--- @return ImGuiKeyRoutingData
function ImGui.GetShortcutRoutingData(key_chord)
    -- Majority of shortcuts will be Key + any number of Mods
    -- We accept _Single_ mod with ImGuiKey.None.
    --  - Shortcut(ImGuiKey.S | ImGuiMod_Ctrl)                    -- Legal
    --  - Shortcut(ImGuiKey.S | ImGuiMod_Ctrl | ImGuiMod_Shift)   -- Legal
    --  - Shortcut(ImGuiMod_Ctrl)                                 -- Legal
    --  - Shortcut(ImGuiMod_Ctrl | ImGuiMod_Shift)                -- Not legal
    local g = GImGui
    local rt = g.KeysRoutingTable
    local key = bit32.band(key_chord, bit32.bnot(ImGuiMod_Mask_))
    local mods = bit32.band(key_chord, ImGuiMod_Mask_)
    if key == ImGuiKey.None then
        key = ImGui.ConvertSingleModFlagToKey(mods)
    end
    IM_ASSERT(ImGui.IsNamedKey(key))

    -- Get (in the majority of case, the linked list will have one element so this should be 2 reads.
    -- Subsequent elements will be contiguous in memory as list is sorted/rebuilt in NewFrame).
    local routing_data
    local idx = rt.Index[key - ImGuiKey.NamedKey_BEGIN + 1]
    while idx ~= -1 do
        routing_data = rt.Entries.Data[idx]
        if routing_data.Mods == mods then
            return routing_data
        end

        idx = routing_data.NextEntryIndex
    end

    -- Add to linked-list
    local routing_data_idx = rt.Entries.Size + 1
    rt.Entries:push_back(ImGuiKeyRoutingData())
    routing_data = rt.Entries[routing_data_idx]
    routing_data.Mods = mods
    routing_data.NextEntryIndex = rt.Index[key - ImGuiKey.NamedKey_BEGIN + 1] -- Setup linked list
    rt.Index[key - ImGuiKey.NamedKey_BEGIN + 1] = routing_data_idx

    return routing_data
end

-- Current score encoding
--  -        0: Never route
--  -        1: ImGuiInputFlags.RouteGlobal    (lower priority)
--  - 100..199: ImGuiInputFlags.RouteFocused   (if window in focus-stack)
--         200: ImGuiInputFlags.RouteGlobal  | ImGuiInputFlags.RouteOverFocused
--         300: ImGuiInputFlags.RouteActive or ImGuiInputFlags.RouteFocused (if item active)
--         400: ImGuiInputFlags.RouteGlobal  | ImGuiInputFlags.RouteOverActive
--  - 500..599: ImGuiInputFlags.RouteFocused | ImGuiInputFlags.RouteOverActive (if window in focus-stack) (higher priority)
-- 'flags' should include an explicit routing policy
--- @param focus_scope_id ImGuiID
--- @param owner_id       ImGuiID
--- @param flags          ImGuiInputFlags
local function CalcRoutingScore(focus_scope_id, owner_id, flags)
    local g = GImGui
    if bit32.band(flags, ImGuiInputFlags.RouteFocused) ~= 0 then
        -- ActiveID gets high priority
        -- (we don't check g.ActiveIdUsingAllKeys here. Routing is applied but if input ownership is tested later it may discard it)
        if owner_id ~= 0 and g.ActiveId == owner_id then
            return 300
        end

        -- Score based on distance to focused window (lower is better)
        -- Assuming both windows are submitting a routing request,
        -- - When Window....... is focused -> Window scores 3 (best), Window/ChildB scores 255 (no match)
        -- - When Window/ChildB is focused -> Window scores 4,        Window/ChildB scores 3 (best)
        -- Assuming only WindowA is submitting a routing request,
        -- - When Window/ChildB is focused -> Window scores 4 (best), Window/ChildB doesn't have a score.
        -- This essentially follow the window.ParentWindowForFocusRoute chain.
        if focus_scope_id == 0 then
            return 0
        end
        for index_in_focus_path = 1, g.NavFocusRoute.Size do
            if g.NavFocusRoute.Data[index_in_focus_path].ID == focus_scope_id then
                if bit32.band(flags, ImGuiInputFlags.RouteOverActive) ~= 0 then -- && g.ActiveId != 0 && g.ActiveId != owner_id)
                    return 599 - (index_in_focus_path - 1)
                else
                    return 199 - (index_in_focus_path - 1)
                end
            end
        end
        return 0
    elseif bit32.band(flags, ImGuiInputFlags.RouteActive) ~= 0 then
        if owner_id ~= 0 and g.ActiveId == owner_id then
            return 300
        end
        return 0
    elseif bit32.band(flags, ImGuiInputFlags.RouteGlobal) ~= 0 then
        if bit32.band(flags, ImGuiInputFlags.RouteOverActive) ~= 0 then
            return 400
        end
        if owner_id ~= 0 and g.ActiveId == owner_id then
            return 300
        end
        if bit32.band(flags, ImGuiInputFlags.RouteOverFocused) ~= 0 then
            return 200
        end
        return 1
    end
    IM_ASSERT(false)
    return 0
end

-- - We need this to filter some Shortcut() routes when an item e.g. an InputText() is active
--   e.g. ImGuiKey.G won't be considered a shortcut when item is active, but ImGuiMod|ImGuiKey.G can be.
-- - This is also used by UpdateInputEvents() to avoid trickling in the most common case of e.g. pressing ImGuiKey.G also emitting a G character.
--- @param key_chord ImGuiKeyChord
local function IsKeyChordPotentiallyCharInput(key_chord)
    -- Mimic 'ignore_char_inputs' logic in InputText()
    local g = GImGui

    -- When the right mods are pressed it cannot be a char input so we won't filter the shortcut out.
    local mods = bit32.band(key_chord, ImGuiMod_Mask_)
    local ignore_char_inputs = ((bit32.band(mods, ImGuiMod_Ctrl) ~= 0) and (bit32.band(mods, ImGuiMod_Alt) == 0)) or (g.IO.ConfigMacOSXBehaviors and (bit32.band(mods, ImGuiMod_Ctrl) ~= 0))
    if ignore_char_inputs then
        return false
    end

    -- Return true for A-Z, 0-9 and other keys associated to char inputs. Other keys such as F1-F12 won't be filtered.
    local key = bit32.band(key_chord, bit32.bnot(ImGuiMod_Mask_))
    if key == ImGuiKey.None then
        return false
    end
    return g.KeysMayBeCharInput:TestBit(key + 1) -- TestBit requires 1-based index
end

-- Request a desired route for an input chord (key + mods).
-- Return true if the route is available this frame.
-- - Routes and key ownership are attributed at the beginning of next frame based on best score and mod state.
--   (Conceptually this does a "Submit for next frame" + "Test for current frame".
--   As such, it could be called TrySetXXX or SubmitXXX, or the Submit and Test operations should be separate.)
--- @param key_chord ImGuiKeyChord
--- @param flags     ImGuiInputFlags
--- @param owner_id  ImGuiID
function ImGui.SetShortcutRouting(key_chord, flags, owner_id)
    local g = GImGui

    if bit32.band(flags, ImGuiInputFlags.RouteTypeMask_) == 0 then
        flags = bit32.bor(flags, ImGuiInputFlags.RouteGlobal, ImGuiInputFlags.RouteOverFocused, ImGuiInputFlags.RouteOverActive) -- IMPORTANT: This is the default for SetShortcutRouting() but NOT Shortcut()
    else
        IM_ASSERT(ImIsPowerOfTwo(bit32.band(flags, ImGuiInputFlags.RouteTypeMask_))) -- Check that only 1 routing flag is used
    end
    IM_ASSERT(owner_id ~= ImGuiKeyOwner_Any and owner_id ~= ImGuiKeyOwner_NoOwner)
    if bit32.band(flags, bit32.bor(ImGuiInputFlags.RouteOverFocused, ImGuiInputFlags.RouteUnlessBgFocused)) ~= 0 then
        IM_ASSERT(bit32.band(flags, ImGuiInputFlags.RouteGlobal) ~= 0)
    end
    if bit32.band(flags, ImGuiInputFlags.RouteOverActive) ~= 0 then
        IM_ASSERT(bit32.band(flags, bit32.bor(ImGuiInputFlags.RouteGlobal, ImGuiInputFlags.RouteFocused)) ~= 0)
    end

    -- Add ImGuiMod_XXXX when a corresponding ImGuiKey.LeftXXX/ImGuiKey.RightXXX is specified.
    key_chord = ImGui.FixupKeyChord(key_chord)

    -- [DEBUG] Debug break requested by user
    if g.DebugBreakInShortcutRouting == key_chord then
        -- IM_DEBUG_BREAK()
    end

    if bit32.band(flags, ImGuiInputFlags.RouteUnlessBgFocused) ~= 0 then
        if g.NavWindow == nil then
            return false
        end
    end

    -- Note how ImGuiInputFlags.RouteAlways won't set routing and thus won't set owner. May want to rework this?
    if bit32.band(flags, ImGuiInputFlags.RouteAlways) ~= 0 then
        -- IMGUI_DEBUG_LOG_INPUTROUTING("SetShortcutRouting(%s, flags=%04X, owner_id=0x%08X) -> always, no register", ImGui.GetKeyChordName(key_chord), flags, owner_id)
        return true
    end

    -- Specific culling when there's an active item.
    if g.ActiveId ~= 0 and g.ActiveId ~= owner_id then
        if bit32.band(flags, ImGuiInputFlags.RouteActive) ~= 0 then
            return false
        end

        -- Cull shortcuts with no modifiers when it could generate a character.
        -- e.g. Shortcut(ImGuiKey.G) also generates 'g' character, should not trigger when InputText() is active.
        -- but  Shortcut(Ctrl+G) should generally trigger when InputText() is active.
        -- TL;DR: lettered shortcut with no mods or with only Alt mod will not trigger while an item reading text input is active.
        -- (We cannot filter based on io.InputQueueCharacters[] contents because of trickling and key<>chars submission order are undefined)
        if g.IO.WantTextInput and IsKeyChordPotentiallyCharInput(key_chord) then
            -- IMGUI_DEBUG_LOG_INPUTROUTING("SetShortcutRouting(%s, flags=%04X, owner_id=0x%08X) -> filtered as potential char input", ImGui.GetKeyChordName(key_chord), flags, owner_id)
            return false
        end

        -- ActiveIdUsingAllKeyboardKeys trumps all for ActiveId
        if bit32.band(flags, ImGuiInputFlags.RouteOverActive) == 0 and g.ActiveIdUsingAllKeyboardKeys then
            local key = bit32.band(key_chord, bit32.bnot(ImGuiMod_Mask_))
            if key == ImGuiKey.None then
                key = ImGui.ConvertSingleModFlagToKey(bit32.band(key_chord, ImGuiMod_Mask_))
            end
            if key >= ImGuiKey_Keyboard_BEGIN and key < ImGuiKey_Keyboard_END then
                return false
            end
        end
    end

    -- Where do we evaluate route for?
    local focus_scope_id = g.CurrentFocusScopeId
    if bit32.band(flags, ImGuiInputFlags.RouteFromRootWindow) ~= 0 then
        focus_scope_id = g.CurrentWindow.RootWindow.ID -- See PushFocusScope() call in Begin()
    end

    local score = CalcRoutingScore(focus_scope_id, owner_id, flags)
    -- IMGUI_DEBUG_LOG_INPUTROUTING("SetShortcutRouting(%s, flags=%04X, owner_id=0x%08X) -> score %d", ImGui.GetKeyChordName(key_chord), flags, owner_id, score)
    if score == 0 then
        return false
    end

    -- Submit routing for NEXT frame (assuming score is sufficient)
    -- FIXME: Could expose a way to use a "serve last" policy for same score resolution (using >= instead of >).
    local routing_data = ImGui.GetShortcutRoutingData(key_chord)
    -- const bool set_route = (flags & ImGuiInputFlags_ServeLast) ? (score >= routing_data->RoutingNextScore) : (score > routing_data->RoutingNextScore);
    if score > routing_data.RoutingNextScore then
        routing_data.RoutingNext = owner_id
        routing_data.RoutingNextScore = score
    end

    -- Return routing state for CURRENT frame
    if routing_data.RoutingCurr == owner_id then
        -- IMGUI_DEBUG_LOG_INPUTROUTING("--> granting current route")
    end
    return routing_data.RoutingCurr == owner_id
end

-- We typically use ImVec2(-FLT_MAX,-FLT_MAX) to denote an invalid mouse position.
--- @param mouse_pos? ImVec2
function ImGui.IsMousePosValid(mouse_pos)
    local MOUSE_INVALID = -256000.0
    local p
    if mouse_pos then p = mouse_pos else p = GImGui.IO.MousePos end
    return p.x >= MOUSE_INVALID and p.y >= MOUSE_INVALID
end

-- [WILL OBSOLETE] This was designed for backends, but prefer having backend maintain a mask of held mouse buttons, because upcoming input queue system will make this invalid.
--- @return bool
function ImGui.IsAnyMouseDown()
    local g = GImGui
    for n = 0, 2 do -- IM_COUNTOF(g.IO.MouseDown) - 1
        if g.IO.MouseDown[n] then
            return true
        end
    end
    return false
end

--- @param button    ImGuiMouseButton
--- @param owner_id? ImGuiID
function ImGui.IsMouseDown(button, owner_id)
    if owner_id == nil then owner_id = ImGuiKeyOwner_Any end

    local g = GImGui
    IM_ASSERT(button >= 0 and button < 3) -- IM_COUNTOF(g.IO.MouseDown)
    return g.IO.MouseDown[button] and ImGui.TestKeyOwner(ImGui.MouseButtonToKey(button), owner_id) -- Should be same as IsKeyDown(MouseButtonToKey(button), owner_id), but this allows legacy code hijacking the io.Mousedown[] array.
end

--- @param button     ImGuiMouseButton
--- @param is_repeat? bool
function ImGui.IsMouseClicked(button, is_repeat)
    if is_repeat == nil then is_repeat = false end

    return ImGui.IsMouseClickedEx(button, is_repeat and ImGuiInputFlags.Repeat or ImGuiInputFlags.None, ImGuiKeyOwner_Any)
end

--- @param button     ImGuiMouseButton
--- @param flags      ImGuiInputFlags
--- @param owner_id?  ImGuiID

function ImGui.IsMouseClickedEx(button, flags, owner_id)
    if owner_id  == nil  then owner_id = ImGuiKeyOwner_Any end

    local g = GImGui
    IM_ASSERT(button >= 0 and button < 3) -- IM_COUNTOF(g.IO.MouseDown)

    if not g.IO.MouseDown[button] then -- In theory this should already be encoded as (DownDuration < 0.0f), but testing this facilitates eating mechanism (until we finish work on key ownership)
        return false
    end
    local t = g.IO.MouseDownDuration[button]
    if t < 0.0 then
        return false
    end
    IM_ASSERT(bit32.band(flags, bit32.bnot(ImGuiInputFlags.SupportedByIsMouseClicked)) == 0) -- Passing flags not supported by this function! -- FIXME: Could support RepeatRate and RepeatUntil flags here.

    local is_repeat = (bit32.band(flags, ImGuiInputFlags.Repeat) ~= 0)
    local pressed = (t == 0.0) or (is_repeat and t > g.IO.KeyRepeatDelay and ImGui.CalcTypematicRepeatAmount(t - g.IO.DeltaTime, t, g.IO.KeyRepeatDelay, g.IO.KeyRepeatRate) > 0)

    if not pressed then
        return false
    end

    if not ImGui.TestKeyOwner(ImGui.MouseButtonToKey(button), owner_id) then
        return false
    end

    return true
end

--- @param button    ImGuiMouseButton
--- @param owner_id? ImGuiID
function ImGui.IsMouseReleased(button, owner_id)
    if owner_id == nil then owner_id = ImGuiKeyOwner_Any end

    local g = GImGui
    IM_ASSERT(button >= 0 and button < 3) -- IM_COUNTOF(g.IO.MouseDown)
    return g.IO.MouseReleased[button] and ImGui.TestKeyOwner(ImGui.MouseButtonToKey(button), owner_id) -- Should be same as IsKeyReleased(MouseButtonToKey(button), owner_id)
end

-- Prefer higher-level helper GetItemClickedCountWithSingleClickDelay()
-- Use if you absolutely need to distinguish single-click from double-click by introducing a delay.
-- Generally use with 'delay >= io.MouseDoubleClickTime' + combined with a 'io.MouseClickedLastCount == 1' test.
-- This is a very rarely used UI idiom, but some apps use this: e.g. MS Explorer single click on an icon to rename.
--- @param button ImGuiMouseButton
--- @param delay? float
function ImGui.IsMouseReleasedWithDelay(button, delay)
    if delay == nil then delay = -1.0 end
    local g = GImGui
    IM_ASSERT(button >= 0 and button < 3)
    if ImGui.IsMouseDown(button) then
        return false
    end
    if delay < 0.0 then
        delay = g.IO.MouseSingleClickDelay or 0.50
    end
    local time_since_release = g.Time - g.IO.MouseReleasedTime[button]
    return (time_since_release - g.IO.DeltaTime < delay) and (time_since_release >= delay)
end

--- @param button    ImGuiMouseButton
--- @param owner_id? ImGuiID
function ImGui.IsMouseDoubleClicked(button, owner_id)
    if owner_id == nil then owner_id = ImGuiKeyOwner_Any end
    local g = GImGui
    IM_ASSERT(button >= 0 and button < 3)
    return g.IO.MouseClickedCount[button] == 2 and ImGui.TestKeyOwner(ImGui.MouseButtonToKey(button), owner_id)
end

--- @param button ImGuiMouseButton
function ImGui.GetMouseClickedCount(button)
    local g = GImGui
    IM_ASSERT(button >= 0 and button < 3)
    return g.IO.MouseClickedCount[button]
end

-- FIXME: This is close to what BeginDragDropSource() is doing, maybe rework.
--- @param mouse_button ImGuiMouseButton
local function LastItemOverlayButtonForNullId(mouse_button)
    local g = GImGui
    IM_ASSERT(g.LastItemData.ID == 0)
    local window = g.CurrentWindow
    local id = window:GetIDFromRectangle(g.LastItemData.Rect)
    if g.IO.MouseClicked[mouse_button] and ImGui.ItemHoverable(g.LastItemData.Rect, id, g.LastItemData.ItemFlags) then
        ImGui.SetActiveID(id, window)
        ImGui.FocusWindow(window)
    elseif g.ActiveId == id then
        ImGui.KeepAliveID(id)
        if not g.IO.MouseDown[mouse_button] then
            ImGui.ClearActiveID()
        end
    end
    return id
end

-- [BETA] Building block for disambiguation between single-click and double-click.
-- - Returns 1 on single-click but delayed by io.MouseSingleClickDelay (which is always > io.MouseDoubleClickTime) after mouse release.
-- - Returns 2+ on double-click and subsequent repeated clicks.
-- In order use that to replicate Windows Explorer's "click on label to rename after a delay",
-- When the function returns 1 for a delayed single click, you can add with further tests:
-- - If you want to test that the mouse position AT THE TIME of the click (before the delay): you can use the 'io.MouseClickedPos[mouse_button]' position.
-- - If you want to test that the mouse position is still over the item at the end of delay: you can use '&& IsItemHovered()'.
-- - If you want to test that the item was selected or the sole selection AT THE TIME of the click (before the delay): you can test for 'g.LastActiveIdWasSelected' or 'g.LastActiveIdWasSoleSelected'.
-- e.g.
--   local click_count = ImGui.GetItemClickedCountWithSingleClickDelay(mouse_button)
--   if click_count == 1 and ImGui.GetCurrentContext().LastActiveIdWasSoleSelected then
--       StartRename()
--   end
--   if click_count == 2 then
--       Launch()
--   end
--- @param mouse_button? ImGuiMouseButton
--- @param delay?        float
--- @return int
function ImGui.GetItemClickedCountWithSingleClickDelay(mouse_button, delay)
    if mouse_button == nil then mouse_button = 0 end
    if delay == nil then delay = -1.0 end
    -- Action: double-click and subsequent clicks
    local g = GImGui
    if g.IO.MouseClickedCount[mouse_button] >= 2 and ImGui.IsItemClicked(mouse_button) then
        return g.IO.MouseClickedCount[mouse_button]
    end

    -- Action: second click, delayed
    local id = g.LastItemData.ID
    if id == 0 then
        id = LastItemOverlayButtonForNullId(mouse_button)
    end
    if g.LastActiveId == id then
        if delay >= 0.0 then
            delay = ImMax(delay, g.IO.MouseDoubleClickTime + 0.01)
        end
        if ImGui.IsMouseReleasedWithDelay(mouse_button, delay) and g.IO.MouseClickedLastCount[mouse_button] == 1 then
            return 1
        end
    end
    return 0
end

--- @return ImVec2 # Ref
function ImGui.GetMousePos()
    return GImGui.IO.MousePos
end

--- @return ImVec2
function ImGui.GetMousePosOnOpeningCurrentPopup()
    local g = GImGui
    if g.BeginPopupStack.Size > 0 then
        return g.BeginPopupStack.Data[g.BeginPopupStack.Size].OpenMousePos
    end
    return g.IO.MousePos
end

-- Return the delta from the initial clicking position while the mouse button is clicked or was just released.
-- This is locked and return 0.0f until the mouse moves past a distance threshold at least once.
-- NB: This is only valid if IsMousePosValid(). backends in theory should always keep mouse position valid when dragging even outside the client window.
--- @param button?         ImGuiMouseButton
--- @param lock_threshold? float
--- @return ImVec2
function ImGui.GetMouseDragDelta(button, lock_threshold)
    if button == nil then button = 0 end
    if lock_threshold == nil then lock_threshold = -1.0 end
    local g = GImGui
    IM_ASSERT(button >= 0 and button < 3)
    if lock_threshold < 0.0 then
        lock_threshold = g.IO.MouseDragThreshold
    end
    if g.IO.MouseDown[button] or g.IO.MouseReleased[button] then
        if g.IO.MouseDragMaxDistanceSqr[button] >= lock_threshold * lock_threshold then
            if ImGui.IsMousePosValid(g.IO.MousePos) and ImGui.IsMousePosValid(g.IO.MouseClickedPos[button]) then
                return g.IO.MousePos - g.IO.MouseClickedPos[button]
            end
        end
    end
    return ImVec2(0.0, 0.0)
end

--- @param button? ImGuiMouseButton
function ImGui.ResetMouseDragDelta(button)
    if button == nil then button = 0 end
    local g = GImGui
    IM_ASSERT(button >= 0 and button < 3)
    -- NB: We don't need to reset g.IO.MouseDragMaxDistanceSqr
    ImVec2_Copy(g.IO.MouseClickedPos[button], g.IO.MousePos)
end

do

local key_changed_mask = ImBitArray(ImGuiKey.NamedKey_COUNT)

-- Process input queue
-- We always call this with the value of 'bool g.IO.ConfigInputTrickleEventQueue'.
-- - trickle_fast_inputs = false : process all events, turn into flattened input state (e.g. successive down/up/down/up will be lost)
-- - trickle_fast_inputs = true  : process as many events as possible (successive down/up/down/up will be trickled over several frames so nothing is lost) (new feature in 1.87)
--- @param trickle_fast_inputs bool
function ImGui.UpdateInputEvents(trickle_fast_inputs)
    local g = GImGui
    local io = g.IO

    -- Only trickle chars<>key when working with InputText()
    -- FIXME: InputText() could parse event trail?
    -- FIXME: Could specialize chars<>keys trickling rules for control keys (those not typically associated to characters)
    local trickle_interleaved_nonchar_keys_and_text = trickle_fast_inputs and g.WantTextInputNextFrame == 1

    local mouse_moved          = false
    local mouse_wheeled        = false
    local key_changed          = false
    local key_changed_nonchar  = false
    local text_inputted        = false
    local mouse_button_changed = 0x00

    key_changed_mask:ClearAllBits()

    local event_n = 1
    local stop_3231 = false
    while event_n <= g.InputEventsQueue.Size do
        repeat
        local e = g.InputEventsQueue.Data[event_n]
        if e.Type == ImGuiInputEventType.MousePos then
            if g.IO.WantSetMousePos then
                break
            end
            -- Trickling Rule: Stop processing queued events if we already handled a mouse button change
            if trickle_fast_inputs and (mouse_button_changed ~= 0 or mouse_wheeled or key_changed or text_inputted) then
                stop_3231 = true; break
            end
            local event_pos = ImVec2(e.MousePos.PosX, e.MousePos.PosY)
            io.MousePos =  event_pos
            io.MouseSource = e.MousePos.MouseSource
            mouse_moved = true
        elseif e.Type == ImGuiInputEventType.MouseButton then
            -- Trickling Rule: Stop processing queued events if we got multiple action on the same button
            local button = e.MouseButton.Button
            IM_ASSERT(button >= 0 and button < ImGuiMouseButton.COUNT)
            if trickle_fast_inputs and ((bit32.band(mouse_button_changed, bit32.lshift(1, button)) ~= 0) or mouse_wheeled) then
                stop_3231 = true; break
            end
            if trickle_fast_inputs and e.MouseButton.MouseSource == ImGuiMouseSource.TouchScreen and mouse_moved then -- #2702: TouchScreen have no initial hover.
                stop_3231 = true; break
            end

            io.MouseDown[button] = e.MouseButton.Down
            io.MouseSource = e.MouseButton.MouseSource
            mouse_button_changed = bit32.bor(mouse_button_changed, bit32.lshift(1, button))
        elseif e.Type == ImGuiInputEventType.MouseWheel then
            -- Trickling Rule: Stop processing queued events if we got multiple action on the event
            if trickle_fast_inputs and (mouse_moved or mouse_button_changed ~= 0) then
                stop_3231 = true; break
            end

            io.MouseWheelH = io.MouseWheelH + e.MouseWheel.WheelX
            io.MouseWheel = io.MouseWheel + e.MouseWheel.WheelY
            io.MouseSource = e.MouseWheel.MouseSource
            mouse_wheeled = true
        elseif e.Type == ImGuiInputEventType.MouseViewport then
            io.MouseHoveredViewport = e.MouseViewport.HoveredViewportID
        elseif e.Type == ImGuiInputEventType.Key then
            -- Trickling Rule: Stop processing queued events if we got multiple action on the same button
            if bit32.band(io.ConfigFlags, ImGuiConfigFlags.NoKeyboard) ~= 0 then
                break
            end

            local key = e.Key.Key
            IM_ASSERT(key ~= ImGuiKey.None)

            -- TODO: Also gets 0-based index here, consider making key_data storage 1-based
            local key_data, key_data_index = ImGui.GetKeyData(g, key)

            if trickle_fast_inputs and key_data.Down ~= e.Key.Down and (key_changed_mask:TestBit(key_data_index + 1) or mouse_button_changed ~= 0) then
                stop_3231 = true; break
            end

            local key_is_potentially_for_char_input = IsKeyChordPotentiallyCharInput(bit32.bor(ImGui.GetMergedModsFromKeys(), key))
            if trickle_interleaved_nonchar_keys_and_text and (text_inputted and not key_is_potentially_for_char_input) then
                stop_3231 = true; break
            end

            if key_data.Down ~= e.Key.Down then -- Analog change only do not trigger this, so it won't block e.g. further mouse pos events testing key_changed.
                key_changed = true
                key_changed_mask:SetBit(key_data_index + 1)
                if trickle_interleaved_nonchar_keys_and_text and not key_is_potentially_for_char_input then
                    key_changed_nonchar = true
                end
            end

            key_data.Down = e.Key.Down
            key_data.AnalogValue = e.Key.AnalogValue
        elseif e.Type == ImGuiInputEventType.Text then
            if bit32.band(io.ConfigFlags, ImGuiConfigFlags.NoKeyboard) ~= 0 then
                break
            end
            -- Trickling Rule: Stop processing queued events if keys/mouse have been interacted with
            if trickle_fast_inputs and (mouse_button_changed ~= 0 or mouse_moved or mouse_wheeled) then
                stop_3231 = true; break
            end
            if trickle_interleaved_nonchar_keys_and_text and key_changed_nonchar then
                stop_3231 = true; break
            end
            local c = e.Text.Char
            io.InputQueueCharacters:push_back((c <= IM_UNICODE_CODEPOINT_MAX) and c or IM_UNICODE_CODEPOINT_INVALID)
            if trickle_interleaved_nonchar_keys_and_text then
                text_inputted = true
            end
        elseif e.Type == ImGuiInputEventType.Focus then
            -- We intentionally overwrite this and process in NewFrame(), in order to give a chance
            -- to multi-viewports backends to queue AddFocusEvent(false) + AddFocusEvent(true) in same frame.
            local focus_lost = not e.AppFocused.Focused
            io.AppFocusLost = focus_lost
        else
            IM_ASSERT(false, "Unknown event!")
        end

        until true
        if stop_3231 then break end

        event_n = event_n + 1
    end

    -- Remaining events will be processed on the next frame
    -- FIXME-MULTITHREADING: io.AddKeyEvent() etc. calls are mostly thread-safe apart from the fact they push to this
    -- queue which may be resized here. Could potentially rework this to narrow down the section needing a mutex? (#5772)
    if event_n == g.InputEventsQueue.Size + 1 then
        g.InputEventsQueue:resize(0)
    else
        for i = 1, event_n - 1 do
            g.InputEventsQueue:erase(1)
        end
    end

    -- Clear buttons state when focus is lost
    -- - this is useful so e.g. releasing Alt after focus loss on Alt-Tab doesn't trigger the Alt menu toggle.
    -- - we clear in EndFrame() and not now in order allow application/user code polling this flag
    --   (e.g. custom backend may want to clear additional data, custom widgets may want to react with a "canceling" event).
    if g.IO.AppFocusLost then
        g.IO:ClearInputKeys()
        g.IO:ClearInputMouse()
    end
end

end

-- _LockXXX flags are useful to lock keys away from code which is not input-owner aware.
-- When using _LockXXX flags, you can use ImGuiKeyOwner_Any to lock keys from everyone.
-- - SetKeyOwner(..., None)              : clears owner
-- - SetKeyOwner(..., Any, !Lock)        : illegal (assert)
-- - SetKeyOwner(..., Any or None, Lock) : set lock
-- Ownership is automatically released on the frame after a release, see code in UpdateKeyboardInputs().
--- @param key      ImGuiKey
--- @param owner_id ImGuiID
--- @param flags?   ImGuiInputFlags
function ImGui.SetKeyOwner(key, owner_id, flags)
    if flags == nil then flags = 0 end

    local g = GImGui --- @cast g ImGuiContext
    IM_ASSERT(ImGui.IsNamedKeyOrMod(key) and (owner_id ~= ImGuiKeyOwner_Any or (bit32.band(flags, bit32.bor(ImGuiInputFlags.LockThisFrame, ImGuiInputFlags.LockUntilRelease)) ~= 0)), "Can only use _Any with _LockXXX flags (to eat a key away without an ID to retrieve it)")
    IM_ASSERT(bit32.band(flags, bit32.bnot(ImGuiInputFlags.SupportedBySetKeyOwner)) == 0, "Passing flags not supported by this function!")
    -- IMGUI_DEBUG_LOG("SetKeyOwner(%s, owner_id=0x%08X, flags=%08X)\n", GetKeyName(key), owner_id, flags)

    local owner_data = ImGui.GetKeyOwnerData(g, key)
    owner_data.OwnerCurr = owner_id
    owner_data.OwnerNext = owner_id

    -- We cannot lock by default as it would likely break lots of legacy code.
    -- In the case of using LockUntilRelease while key is not down we still lock during the frame (no key_data.Down test)
    owner_data.LockUntilRelease = (bit32.band(flags, ImGuiInputFlags.LockUntilRelease) ~= 0)
    owner_data.LockThisFrame = (bit32.band(flags, ImGuiInputFlags.LockThisFrame) ~= 0) or owner_data.LockUntilRelease
end

-- Rarely used helper
--- @param key_chord ImGuiKeyChord
--- @param owner_id  ImGuiID
--- @param flags?    ImGuiInputFlags
function ImGui.SetKeyOwnersForKeyChord(key_chord, owner_id, flags)
    if flags == nil then flags = 0 end

    if bit32.band(key_chord, ImGuiMod_Ctrl) ~= 0 then
        ImGui.SetKeyOwner(ImGuiMod_Ctrl, owner_id, flags)
    end
    if bit32.band(key_chord, ImGuiMod_Shift) ~= 0 then
        ImGui.SetKeyOwner(ImGuiMod_Shift, owner_id, flags)
    end
    if bit32.band(key_chord, ImGuiMod_Alt) ~= 0 then
        ImGui.SetKeyOwner(ImGuiMod_Alt, owner_id, flags)
    end
    if bit32.band(key_chord, ImGuiMod_Super) ~= 0 then
        ImGui.SetKeyOwner(ImGuiMod_Super, owner_id, flags)
    end
    if bit32.band(key_chord, bit32.bnot(ImGuiMod_Mask_)) ~= 0 then
        ImGui.SetKeyOwner(bit32.band(key_chord, bit32.bnot(ImGuiMod_Mask_)), owner_id, flags)
    end
end

-- This is more or less equivalent to a fancier version of:
--   if (IsItemHovered() || IsItemActive())
--       SetKeyOwner(key, GetItemID());
-- Extensive uses of that (e.g. many calls for a single item) may want to manually perform the tests once and then call SetKeyOwner() multiple times.
-- More advanced usage scenarios may want to call SetKeyOwner() manually based on different condition.
-- Worth noting is that only one item can be hovered and only one item can be active, therefore this usage pattern doesn't need to bother with routing and priority.
--- @param key    ImGuiKey
--- @param flags? ImGuiInputFlags
function ImGui.SetItemKeyOwner(key, flags)
    if flags == nil then flags = ImGuiInputFlags.None end

    local g = GImGui
    local id = g.LastItemData.ID
    if id == 0 or (g.HoveredId ~= id and g.ActiveId ~= id) then
        return false
    end
    if bit32.band(flags, ImGuiInputFlags.CondMask_) == 0 then
        flags = bit32.bor(flags, ImGuiInputFlags.CondDefault_)
    end
    if (g.HoveredId == id and bit32.band(flags, ImGuiInputFlags.CondHovered) ~= 0) or (g.ActiveId == id and bit32.band(flags, ImGuiInputFlags.CondActive) ~= 0) then
        IM_ASSERT(bit32.band(flags, bit32.bnot(ImGuiInputFlags.SupportedBySetItemKeyOwner)) == 0) -- Passing flags not supported by this function!
        if not ImGui.TestKeyOwner(key, id) then
            return false
        end
        ImGui.SetKeyOwner(key, id, bit32.band(flags, bit32.bnot(ImGuiInputFlags.CondMask_)))
        return true
    end
    return false
end

-- This is equivalent to comparing KeyMods + doing a IsKeyPressed()
--- @param key_chord ImGuiKeyChord
--- @param flags     ImGuiInputFlags
--- @param owner_id  ImGuiID
function ImGui.IsKeyChordPressed(key_chord, flags, owner_id)
    local g = GImGui
    key_chord = ImGui.FixupKeyChord(key_chord)
    local mods = bit32.band(key_chord, ImGuiMod_Mask_)
    if g.IO.KeyMods ~= mods then
        return false
    end

    -- Special storage location for mods
    local key = bit32.band(key_chord, bit32.bnot(ImGuiMod_Mask_))
    if key == ImGuiKey.None then
        key = ImGui.ConvertSingleModFlagToKey(mods)
    end
    if not ImGui.IsKeyPressedEx(key, bit32.band(flags, ImGuiInputFlags.RepeatMask_), owner_id) then
        return false
    end
    return true
end

--- @param key_chord ImGuiKeyChord
--- @param flags?    ImGuiInputFlags
function ImGui.SetNextItemShortcut(key_chord, flags)
    if flags == nil then flags = 0 end

    local g = GImGui
    g.NextItemData.HasFlags = bit32.bor(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasShortcut)
    g.NextItemData.Shortcut = key_chord
    g.NextItemData.ShortcutFlags = flags
end

--- @param key_chord ImGuiKeyChord
--- @param flags     ImGuiInputFlags
--- @param owner_id  ImGuiID
function ImGui.Shortcut(key_chord, flags, owner_id)
    local g = GImGui
    -- IMGUI_DEBUG_LOG("Shortcut(%s, flags=%X, owner_id=0x%08X)\n", ImGui.GetKeyChordName(key_chord, g.TempBuffer.Data, g.TempBuffer.Size), flags, owner_id)

    -- When using (owner_id == 0/Any): SetShortcutRouting() will use CurrentFocusScopeId and filter with this, so IsKeyPressed() is fine with he 0/Any.
    if bit32.band(flags, ImGuiInputFlags.RouteTypeMask_) == 0 then
        flags = bit32.bor(flags, ImGuiInputFlags.RouteFocused)
    end

    -- Using 'owner_id == ImGuiKeyOwner_Any/0': auto-assign an owner based on current focus scope (each window has its focus scope by default)
    -- Effectively makes Shortcut() always input-owner aware.
    if owner_id == ImGuiKeyOwner_Any or owner_id == ImGuiKeyOwner_NoOwner then
        owner_id = GetRoutingIdFromOwnerId(owner_id)
    end

    if bit32.band(g.CurrentItemFlags, ImGuiItemFlags.Disabled) ~= 0 then
        return false
    end

    -- Submit route
    if not ImGui.SetShortcutRouting(key_chord, flags, owner_id) then
        return false
    end

    -- Default repeat behavior for Shortcut()
    -- So e.g. pressing Ctrl+W and releasing Ctrl while holding W will not trigger the W shortcut.
    if bit32.band(flags, ImGuiInputFlags.Repeat) ~= 0 and bit32.band(flags, ImGuiInputFlags.RepeatUntilMask_) == 0 then
        flags = bit32.bor(flags, ImGuiInputFlags.RepeatUntilKeyModsChange)
    end

    if not ImGui.IsKeyChordPressed(key_chord, flags, owner_id) then
        return false
    end

    -- Claim mods during the press
    ImGui.SetKeyOwnersForKeyChord(bit32.band(key_chord, ImGuiMod_Mask_), owner_id)

    IM_ASSERT(bit32.band(flags, bit32.bnot(ImGuiInputFlags.SupportedByShortcut)) == 0) -- Passing flags not supported by this function!
    return true
end

--- @param window ImGuiWindow
--- @return bool
function ImGui.IsWindowActiveAndVisible(window)
    return window.Active and not window.Hidden
end

--- @param window ImGuiWindow
--- @nodiscard
local function CalcWindowMinSize(window)
    -- We give windows non-zero minimum size to facilitate understanding problematic cases (e.g. empty popups)
    -- FIXME: Essentially we want to restrict manual resizing to WindowMinSize+Decoration, and allow api resizing to be smaller.
    -- Perhaps should tend further a neater test for this.
    local g = GImGui

    local size_min = ImVec2()

    if (bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0) and (bit32.band(window.Flags, ImGuiWindowFlags.Popup) == 0) then
        if bit32.band(window.ChildFlags, ImGuiChildFlags.ResizeX) ~= 0 then
            size_min.x = g.Style.WindowMinSize.x
        else
            size_min.x = IMGUI_WINDOW_HARD_MIN_SIZE
        end

        if bit32.band(window.ChildFlags, ImGuiChildFlags.ResizeY) ~= 0 then
            size_min.y = g.Style.WindowMinSize.y
        else
            size_min.y = IMGUI_WINDOW_HARD_MIN_SIZE
        end
    else
        if bit32.band(window.Flags, ImGuiWindowFlags.AlwaysAutoResize) == 0 then
            size_min.x = g.Style.WindowMinSize.x
        else
            size_min.x = IMGUI_WINDOW_HARD_MIN_SIZE
        end

        if bit32.band(window.Flags, ImGuiWindowFlags.AlwaysAutoResize) == 0 then
            size_min.y = g.Style.WindowMinSize.y
        else
            size_min.y = IMGUI_WINDOW_HARD_MIN_SIZE
        end
    end

    -- Reduce artifacts with very small windows
    local window_for_height = window
    size_min.y = ImMax(size_min.y, window_for_height.TitleBarHeight + window_for_height.MenuBarHeight + ImMax(0, g.Style.WindowRounding - 1))

    return size_min
end

--- @param window       ImGuiWindow
--- @param size_desired ImVec2
--- @return ImVec2
--- @nodiscard
local function CalcWindowSizeAfterConstraint(window, size_desired)
    local g = GImGui

    local new_size = ImVec2()
    ImVec2_Copy(new_size, size_desired)

    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasSizeConstraint) ~= 0 then
        -- See comments in SetNextWindowSizeConstraints() for details about setting size_min an size_max.
        local cr = ImRect()
        ImRect_Copy(cr, g.NextWindowData.SizeConstraintRect)

        new_size.x = (cr.Min.x >= 0 and cr.Max.x >= 0) and ImClamp(new_size.x, cr.Min.x, cr.Max.x) or window.SizeFull.x
        new_size.y = (cr.Min.y >= 0 and cr.Max.y >= 0) and ImClamp(new_size.y, cr.Min.y, cr.Max.y) or window.SizeFull.y
        if g.NextWindowData.SizeCallback then
            local data = {} -- TODO: ImGuiSizeCallbackData
            data.UserData = g.NextWindowData.SizeCallbackUserData
            data.Pos = ImVec2(window.Pos.x, window.Pos.y)
            data.CurrentSize = ImVec2(window.SizeFull.x, window.SizeFull.y)
            data.DesiredSize = ImVec2(new_size.x, new_size.y)
            g.NextWindowData.SizeCallback(data)
            new_size.x = data.DesiredSize.x
            new_size.y = data.DesiredSize.y
        end
        new_size.x = IM_TRUNC(new_size.x)
        new_size.y = IM_TRUNC(new_size.y)
    end

    -- Minimum size
    local size_min = CalcWindowMinSize(window)
    return ImMax(new_size, size_min)
end

--- @param window               ImGuiWindow
--- @param content_size_current ImVec2
--- @param content_size_ideal   ImVec2
local function CalcWindowContentSizes(window, content_size_current, content_size_ideal)
    local preserve_old_content_sizes = false
    if (window.Collapsed and window.AutoFitFramesX <= 0 and window.AutoFitFramesY <= 0) then
        preserve_old_content_sizes = true
    elseif (window.Hidden and window.HiddenFramesCannotSkipItems == 0 and window.HiddenFramesCanSkipItems > 0) then
        preserve_old_content_sizes = true
    end
    if preserve_old_content_sizes then
        content_size_current.x = window.ContentSize.x
        content_size_current.y = window.ContentSize.y
        content_size_ideal.x = window.ContentSizeIdeal.x
        content_size_ideal.y = window.ContentSizeIdeal.y
        return
    end

    if (window.ContentSizeExplicit.x ~= 0.0) then content_size_current.x = window.ContentSizeExplicit.x else content_size_current.x = ImTrunc64(window.DC.CursorMaxPos.x - window.DC.CursorStartPos.x) end
    if (window.ContentSizeExplicit.y ~= 0.0) then content_size_current.y = window.ContentSizeExplicit.y else content_size_current.y = ImTrunc64(window.DC.CursorMaxPos.y - window.DC.CursorStartPos.y) end
    if (window.ContentSizeExplicit.x ~= 0.0) then content_size_ideal.x = window.ContentSizeExplicit.x else content_size_ideal.x = ImTrunc64(ImMax(window.DC.CursorMaxPos.x, window.DC.IdealMaxPos.x) - window.DC.CursorStartPos.x) end
    if (window.ContentSizeExplicit.y ~= 0.0) then content_size_ideal.y = window.ContentSizeExplicit.y else content_size_ideal.y = ImTrunc64(ImMax(window.DC.CursorMaxPos.y, window.DC.IdealMaxPos.y) - window.DC.CursorStartPos.y) end
end

--- @param window        ImGuiWindow # The window to calculate auto-fit size for
--- @param size_contents ImVec2      # The content size
--- @param axis_mask     int         # The axis mask to determine which axes to auto-fit
--- @return ImVec2                   # The auto-fit size
local function CalcWindowAutoFitSize(window, size_contents, axis_mask)
    local g = GImGui
    local style = g.Style
    local decoration_w_without_scrollbars = window.DecoOuterSizeX1 + window.DecoOuterSizeX2 - window.ScrollbarSizes.x
    local decoration_h_without_scrollbars = window.DecoOuterSizeY1 + window.DecoOuterSizeY2 - window.ScrollbarSizes.y
    local size_pad = ImVec2(window.WindowPadding.x * 2, window.WindowPadding.y * 2)
    local size_desired = ImVec2()
    size_desired.x = (bit32.band(axis_mask, 1) ~= 0) and (size_contents.x + size_pad.x + decoration_w_without_scrollbars) or window.Size.x
    size_desired.y = (bit32.band(axis_mask, 2) ~= 0) and (size_contents.y + size_pad.y + decoration_h_without_scrollbars) or window.Size.y

    -- Determine maximum window size
    -- Child windows are laid within their parent (unless they are also popups/menus) and thus have no restriction
    local size_max = ImVec2(FLT_MAX, FLT_MAX)
    if bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) == 0 or bit32.band(window.Flags, ImGuiWindowFlags.Popup) ~= 0 then
        if not window.ViewportOwned then
            size_max = ImGui.GetMainViewport().WorkSize - style.DisplaySafeAreaPadding * 2.0
        end
        local monitor_idx = window.ViewportAllowPlatformMonitorExtend
        if monitor_idx >= 1 and monitor_idx <= g.PlatformIO.Monitors.Size then
            size_max = g.PlatformIO.Monitors.Data[monitor_idx].WorkSize - style.DisplaySafeAreaPadding * 2.0
        end
    end

    if bit32.band(window.Flags, ImGuiWindowFlags.Tooltip) ~= 0 then
        -- Tooltip always resize (up to maximum size)
        return ImMin(size_desired, size_max)
    else
        local size_min = CalcWindowMinSize(window)
        local size_auto_fit = ImClamp(size_desired, ImMin(size_min, size_max), size_max)

        -- When the window cannot fit all contents (either because of constraints, either because screen is too small),
        -- we are growing the size on the other axis to compensate for expected scrollbar. FIXME: Might turn bigger than ViewportSize-WindowPadding.
        local size_auto_fit_after_constraint = CalcWindowSizeAfterConstraint(window, size_auto_fit)
        local size_contents_for_scrollbar_x = (bit32.band(axis_mask, 1) ~= 0) and size_contents.x or window.ContentSize.x -- See #9352. In theory this should use same logic as `window.ScrollbarY = ...` codepath in Begin(). Needs some plumbling.
        local size_contents_for_scrollbar_y = (bit32.band(axis_mask, 2) ~= 0) and size_contents.y or window.ContentSize.y
        local will_have_scrollbar_x = (size_auto_fit_after_constraint.x < size_contents_for_scrollbar_x + size_pad.x + decoration_w_without_scrollbars and bit32.band(window.Flags, ImGuiWindowFlags.NoScrollbar) == 0 and bit32.band(window.Flags, ImGuiWindowFlags.HorizontalScrollbar) ~= 0) or bit32.band(window.Flags, ImGuiWindowFlags.AlwaysHorizontalScrollbar) ~= 0
        local will_have_scrollbar_y = (size_auto_fit_after_constraint.y < size_contents_for_scrollbar_y + size_pad.y + decoration_h_without_scrollbars and bit32.band(window.Flags, ImGuiWindowFlags.NoScrollbar) == 0) or bit32.band(window.Flags, ImGuiWindowFlags.AlwaysVerticalScrollbar) ~= 0
        if will_have_scrollbar_x then
            size_auto_fit.y = size_auto_fit.y + style.ScrollbarSize
        end
        if will_have_scrollbar_y then
            size_auto_fit.x = size_auto_fit.x + style.ScrollbarSize
        end
        return size_auto_fit
    end
end

--- @param window ImGuiWindow
--- @return ImVec2
function ImGui.CalcWindowNextAutoFitSize(window)
    local size_contents_current = ImVec2()
    local size_contents_ideal = ImVec2()
    CalcWindowContentSizes(window, size_contents_current, size_contents_ideal)
    local size_auto_fit = CalcWindowAutoFitSize(window, size_contents_ideal, -1)
    local size_final = CalcWindowSizeAfterConstraint(window, size_auto_fit)
    return size_final
end

--- @param window ImGuiWindow
--- @return ImGuiCol
local function GetWindowBgColorIdx(window)
    if bit32.band(window.Flags, bit32.bor(ImGuiWindowFlags.Tooltip, ImGuiWindowFlags.Popup)) ~= 0 then
        return ImGuiCol.PopupBg
    elseif bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0 and not window.DockIsActive then
        return ImGuiCol.ChildBg
    else
        return ImGuiCol.WindowBg
    end
end

--- @param window            ImGuiWindow
--- @param corner_target_arg ImVec2
--- @param corner_norm       ImVec2
--- @return ImVec2, ImVec2
--- @nodiscard
local function CalcResizePosSizeFromAnyCorner(window, corner_target_arg, corner_norm)
    local corner_target = ImVec2()
    ImVec2_Copy(corner_target, corner_target_arg)

    if bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0 then -- Clamp resizing of childs within parent
        local parent_window = window.ParentWindow
        local parent_flags = parent_window.Flags

        local limit_rect = ImRect()
        ImRect_Copy(limit_rect, parent_window.InnerRect)
        limit_rect:Expand(ImVec2(-ImMax(parent_window.WindowPadding.x, parent_window.WindowBorderSize), -ImMax(parent_window.WindowPadding.y, parent_window.WindowBorderSize)))

        if (bit32.band(parent_flags, bit32.bor(ImGuiWindowFlags.HorizontalScrollbar, ImGuiWindowFlags.AlwaysHorizontalScrollbar)) == 0) or (bit32.band(parent_flags, ImGuiWindowFlags.NoScrollbar) ~= 0) then
            corner_target.x = ImClamp(corner_target.x, limit_rect.Min.x, limit_rect.Max.x)
        end
        if bit32.band(parent_flags, ImGuiWindowFlags.NoScrollbar) ~= 0 then
            corner_target.y = ImClamp(corner_target.y, limit_rect.Min.y, limit_rect.Max.y)
        end
    end
    local pos_min = ImLerp(corner_target, window.Pos, corner_norm)                -- Expected window upper-left
    local pos_max = ImLerp(window.Pos + window.Size, corner_target, corner_norm) -- Expected window lower-right
    local size_expected = pos_max - pos_min
    local size_constrained = CalcWindowSizeAfterConstraint(window, size_expected)

    local out_pos = pos_min
    if corner_norm.x == 0.0 then
        out_pos.x = out_pos.x - (size_constrained.x - size_expected.x)
    end
    if corner_norm.y == 0.0 then
        out_pos.y = out_pos.y - (size_constrained.y - size_expected.y)
    end

    return out_pos, size_constrained
end

-- Handle resize for: Resize Grips, Borders, Gamepad
-- Return true when using auto-fit (double-click on resize grip)
-- Returns (ret_auto_fit_mask, border_hovered, border_held)
--- @param window            ImGuiWindow
--- @param resize_grip_count int
--- @param resize_grip_col   table
--- @param visibility_rect   ImRect
--- @return int, int, int
local function UpdateWindowManualResize(window, resize_grip_count, resize_grip_col, visibility_rect)
    local g = GImGui
    local flags = window.Flags

    if (bit32.band(flags, ImGuiWindowFlags.NoResize) ~= 0 or window.AutoFitFramesX > 0 or window.AutoFitFramesY > 0) then
        return 0, -1, -1
    end
    if (bit32.band(flags, ImGuiWindowFlags.AlwaysAutoResize) ~= 0 and bit32.band(window.ChildFlags, bit32.bor(ImGuiChildFlags.ResizeX, ImGuiChildFlags.ResizeY)) == 0) then
        return 0, -1, -1
    end
    if window.WasActive == false then -- Early out to avoid running this code for e.g. a hidden implicit/fallback Debug window.
        return 0, -1, -1
    end

    local border_hovered = -1
    local border_held = -1

    local ret_auto_fit_mask = 0x00
    local grip_draw_size = IM_TRUNC(ImMax(g.FontSize * 1.35, g.Style.WindowRounding + 1.0 + g.FontSize * 0.2))
    local grip_hover_inner_size = (resize_grip_count > 0) and IM_TRUNC(grip_draw_size * 0.75) or 0.0
    local grip_hover_outer_size = g.WindowsBorderHoverPadding + 1

    ImGui.PushID("#RESIZE")

    local pos_target = ImVec2(FLT_MAX, FLT_MAX)
    local size_target = ImVec2(FLT_MAX, FLT_MAX)

    -- Clip mouse interaction rectangles within the viewport rectangle (in practice the narrowing is going to happen most of the time).
    -- - Not narrowing would mostly benefit the situation where OS windows _without_ decoration have a threshold for hovering when outside their limits.
    --   This is however not the case with current backends under Win32, but a custom borderless window implementation would benefit from it.
    -- - When decoration are enabled we typically benefit from that distance, but then our resize elements would be conflicting with OS resize elements, so we also narrow.
    -- - Note that we are unable to tell if the platform setup allows hovering with a distance threshold (on Win32, decorated window have such threshold).
    -- We only clip interaction so we overwrite window.ClipRect, cannot call PushClipRect() yet as DrawList is not yet setup.
    local clip_with_viewport_rect = bit32.band(g.IO.BackendFlags, ImGuiBackendFlags.HasMouseHoveredViewport) == 0 or g.IO.MouseHoveredViewport ~= window.ViewportId or bit32.band(window.Viewport.Flags, ImGuiViewportFlags.NoDecoration) == 0
    if (clip_with_viewport_rect) then
        ImRect_Copy(window.ClipRect, window.Viewport:GetMainRect())
    end

    local clamp_rect = ImRect()
    ImRect_Copy(clamp_rect, visibility_rect)

    local window_move_from_title_bar = (bit32.band(window.BgClickFlags, ImGuiWindowBgClickFlags.Move) == 0) and (bit32.band(window.Flags, ImGuiWindowFlags.NoTitleBar) == 0)
    if window_move_from_title_bar then
        clamp_rect.Min.y = clamp_rect.Min.y - window.TitleBarHeight
    end

    for resize_grip_n = 0, resize_grip_count - 1 do
        local def = ImGuiResizeGripDef[resize_grip_n + 1]
        local corner_pos = def.CornerPosN
        local inner_dir = def.InnerDir

        local corner = ImVec2(window.Pos.x + corner_pos.x * window.Size.x, window.Pos.y + corner_pos.y * window.Size.y)

        -- Using the FlattenChilds button flag we make the resize button accessible even if we are hovering over a child window
        local resize_rect = ImRect(corner - inner_dir * grip_hover_outer_size, corner + inner_dir * grip_hover_inner_size)

        if resize_rect.Min.x > resize_rect.Max.x then resize_rect.Min.x, resize_rect.Max.x = resize_rect.Max.x, resize_rect.Min.x end
        if resize_rect.Min.y > resize_rect.Max.y then resize_rect.Min.y, resize_rect.Max.y = resize_rect.Max.y, resize_rect.Min.y end

        local resize_grip_id = window:GetID(resize_grip_n) -- == GetWindowResizeCornerID()

        ImGui.ItemAdd(resize_rect, resize_grip_id, nil, ImGuiItemFlags.NoNav)
        local _, hovered, held = ImGui.ButtonBehavior(resize_rect, resize_grip_id, bit32.bor(ImGuiButtonFlags.FlattenChildren, ImGuiButtonFlags.NoNavFocus))
        -- GetForegroundDrawList(window):AddRect(resize_rect.Min, resize_rect.Max, IM_COL32(255, 255, 0, 255))

        if hovered or held then
            ImGui.SetMouseCursor((bit32.band(resize_grip_n, 1) ~= 0) and ImGuiMouseCursor.ResizeNESW or ImGuiMouseCursor.ResizeNWSE)
        end

        if held and g.IO.MouseDoubleClicked[0] then
            -- Auto-fit when double-clicking
            local size_auto_fit = CalcWindowAutoFitSize(window, window.ContentSizeIdeal, -1)
            size_target = CalcWindowSizeAfterConstraint(window, size_auto_fit)
            ret_auto_fit_mask = 0x03 -- Both axes
            ImGui.ClearActiveID()
        elseif held then
            -- Resize from any of the four corners
            -- We don't use an incremental MouseDelta but rather compute an absolute target size based on mouse position
            local clamp_min = ImVec2((corner_pos.x == 1.0) and clamp_rect.Min.x or -FLT_MAX, (corner_pos.y == 1.0) and clamp_rect.Min.y or -FLT_MAX)
            local clamp_max = ImVec2((corner_pos.x == 0.0) and clamp_rect.Max.x or FLT_MAX, (corner_pos.y == 0.0) and clamp_rect.Max.y or FLT_MAX)
            local corner_target = g.IO.MousePos - g.ActiveIdClickOffset + ImLerp(def.InnerDir * grip_hover_outer_size, def.InnerDir * -grip_hover_inner_size, def.CornerPosN) -- Corner of the window corresponding to our corner grip

            corner_target = ImClamp(corner_target, clamp_min, clamp_max)

            pos_target, size_target = CalcResizePosSizeFromAnyCorner(window, corner_target, corner_pos)
        end

        -- Only lower-left grip is visible before hovering/activating
        local resize_grip_visible = held or hovered or (resize_grip_n == 0 and bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) == 0)
        if resize_grip_visible then
            local color
            if held then
                color = ImGui.GetColorU32(ImGuiCol.ResizeGripActive)
            else
                if hovered then
                    color = ImGui.GetColorU32(ImGuiCol.ResizeGripHovered)
                else
                    color = ImGui.GetColorU32(ImGuiCol.ResizeGrip)
                end
            end
            resize_grip_col[resize_grip_n + 1] = color
        end
    end

    local resize_border_mask = 0x00
    if bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0 then
        local mask_x = (bit32.band(window.ChildFlags, ImGuiChildFlags.ResizeX) ~= 0) and 0x02 or 0
        local mask_y = (bit32.band(window.ChildFlags, ImGuiChildFlags.ResizeY) ~= 0) and 0x08 or 0
        resize_border_mask = bit32.bor(mask_x, mask_y)
    else
        resize_border_mask = g.IO.ConfigWindowsResizeFromEdges and 0x0F or 0x00
    end

    for border_n = 0, 3 do
        repeat
        if bit32.band(resize_border_mask, bit32.lshift(1, border_n)) == 0 then
            break
        end

        local def = ImGuiResizeBorderDef[border_n + 1]
        local axis
        if border_n == ImGuiDir.Left or border_n == ImGuiDir.Right then
            axis = ImGuiAxis.X
        else
            axis = ImGuiAxis.Y
        end

        local border_rect = GetResizeBorderRect(window, border_n, grip_hover_inner_size, g.WindowsBorderHoverPadding)
        local border_id = window:GetID(border_n + 4) -- == GetWindowResizeBorderID()
        ImGui.ItemAdd(border_rect, border_id, nil, ImGuiItemFlags.NoNav)
        local _, hovered, held = ImGui.ButtonBehavior(border_rect, border_id, bit32.bor(ImGuiButtonFlags.FlattenChildren, ImGuiButtonFlags.NoNavFocus))
        -- GetForegroundDrawList(window):AddRect(border_rect.Min, border_rect.Max, IM_COL32(255, 255, 0, 255))

        if hovered and g.HoveredIdTimer <= WINDOWS_RESIZE_FROM_EDGES_FEEDBACK_TIMER then
            hovered = false
        end
        if hovered or held then
            ImGui.SetMouseCursor((axis == ImGuiAxis.X) and ImGuiMouseCursor.ResizeEW or ImGuiMouseCursor.ResizeNS)
        end
        if held and g.IO.MouseDoubleClicked[0] then
            -- Double-clicking bottom or right border auto-fit on this axis
            -- FIXME: Support top and right borders: rework CalcResizePosSizeFromAnyCorner() to be reusable in both cases.
            if border_n == 1 or border_n == 3 then -- Right and bottom border
                local size_auto_fit = CalcWindowAutoFitSize(window, window.ContentSizeIdeal, bit32.lshift(1, axis - 1))
                size_target[axis] = CalcWindowSizeAfterConstraint(window, size_auto_fit)[axis]
                ret_auto_fit_mask = bit32.bor(ret_auto_fit_mask, bit32.lshift(1, axis - 1))
                hovered = false
                held = false -- So border doesn't show highlighted at new position
            end
            ImGui.ClearActiveID()
        elseif held then
            -- Switch to relative resizing mode when border geometry moved (e.g. resizing a child altering parent scroll), in order to avoid resizing feedback loop.
            -- Currently only using relative mode on resizable child windows, as the problem to solve is more likely noticeable for them, but could apply for all windows eventually.
            -- FIXME: May want to generalize this idiom at lower-level, so more widgets can use it!
            local just_scrolled_manually_while_resizing = (g.WheelingWindow ~= nil and g.WheelingWindowScrolledFrame == g.FrameCount and ImGui.IsWindowChildOf(window, g.WheelingWindow, false, true))
            if g.ActiveIdIsJustActivated or just_scrolled_manually_while_resizing then
                g.WindowResizeBorderExpectedRect = border_rect
                g.WindowResizeRelativeMode = false
            end

            if (bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0) and g.WindowResizeBorderExpectedRect ~= border_rect then
                g.WindowResizeRelativeMode = true
            end

            local border_curr = window.Pos + ImMin(def.SegmentN1, def.SegmentN2) * window.Size
            local border_target_rel_mode_for_axis
            local border_target_abs_mode_for_axis
            border_target_rel_mode_for_axis = border_curr[axis] + g.IO.MouseDelta[axis]
            border_target_abs_mode_for_axis = g.IO.MousePos[axis] - g.ActiveIdClickOffset[axis] + g.WindowsBorderHoverPadding -- Match ButtonBehavior() padding above.

            -- Use absolute mode position
            local border_target = ImVec2()
            ImVec2_Copy(border_target, window.Pos)
            border_target[axis] = border_target_abs_mode_for_axis

            -- Use relative mode target for child window, ignore resize when moving back toward the ideal absolute position.
            local ignore_resize = false
            if g.WindowResizeRelativeMode then
                -- GetForegroundDrawList():AddText(GetMainViewport().WorkPos, IM_COL32_WHITE, "Relative Mode")
                border_target[axis] = border_target_rel_mode_for_axis
                if g.IO.MouseDelta[axis] == 0.0 or ((g.IO.MouseDelta[axis] > 0.0) == (border_target_rel_mode_for_axis > border_target_abs_mode_for_axis)) then
                    ignore_resize = true
                end
            end

            -- Clamp, apply
            local clamp_min = ImVec2((border_n == ImGuiDir.Right) and clamp_rect.Min.x or -FLT_MAX, (border_n == ImGuiDir.Down or (border_n == ImGuiDir.Up and window_move_from_title_bar)) and clamp_rect.Min.y or -FLT_MAX)
            local clamp_max = ImVec2((border_n == ImGuiDir.Left) and clamp_rect.Max.x or FLT_MAX, (border_n == ImGuiDir.Up) and clamp_rect.Max.y or FLT_MAX)
            border_target = ImClamp(border_target, clamp_min, clamp_max)

            if not ignore_resize then
                pos_target, size_target = CalcResizePosSizeFromAnyCorner(window, border_target, ImMin(def.SegmentN1, def.SegmentN2))
            end
        end
        if hovered then
            border_hovered = border_n
        end
        if held then
            border_held = border_n
        end

        until true
    end
    ImGui.PopID()

    -- Restore nav layer
    window.DC.NavLayerCurrent = ImGuiNavLayer.Main

    -- Apply back modified position/size to window
    if size_target.x ~= FLT_MAX and (window.Size.x ~= size_target.x or window.SizeFull.x ~= size_target.x) then
        window.Size.x = size_target.x
        window.SizeFull.x = size_target.x
    end

    if size_target.y ~= FLT_MAX and (window.Size.y ~= size_target.y or window.SizeFull.y ~= size_target.y) then
        window.Size.y = size_target.y
        window.SizeFull.y = size_target.y
    end

    if pos_target.x ~= FLT_MAX and window.Pos.x ~= ImFloor(pos_target.x) then
        window.Pos.x = ImFloor(pos_target.x)
    end

    if pos_target.y ~= FLT_MAX and window.Pos.y ~= ImFloor(pos_target.y) then
        window.Pos.y = ImFloor(pos_target.y)
    end

    -- Recalculate next expected border expected coordinates
    if border_held ~= -1 then
        g.WindowResizeBorderExpectedRect = GetResizeBorderRect(window, border_held, grip_hover_inner_size, g.WindowsBorderHoverPadding)
    end

    return ret_auto_fit_mask, border_hovered, border_held
end

--- @param pos        ImVec2
--- @param wrap_pos_x float
--- @return float
function ImGui.CalcWrapWidthForPos(pos, wrap_pos_x)
    if wrap_pos_x < 0.0 then
        return 0.0
    end

    local g = GImGui
    local window = g.CurrentWindow
    if wrap_pos_x == 0.0 then
        -- We could decide to setup a default wrapping max point for auto-resizing windows,
        -- or have auto-wrap (with unspecified wrapping pos) behave as a ContentSize extending function?
        -- if (window.Hidden and (window.Flags & ImGuiWindowFlags.AlwaysAutoResize))
        --     wrap_pos_x = ImMax(window.WorkRect.Min.x + g.FontSize * 10.0, window.WorkRect.Max.x)
        -- else
        wrap_pos_x = window.WorkRect.Max.x
    elseif wrap_pos_x > 0.0 then
        wrap_pos_x = wrap_pos_x + window.Pos.x - window.Scroll.x -- wrap_pos_x is provided is window local space
    end

    return math.max(wrap_pos_x - pos.x, 1.0)
end

-------------------------------------------------------------------------------
-- [SECTION] RENDER HELPERS
-- Some of those (internal) functions are currently quite a legacy mess - their signature and behavior will change,
-- we need a nicer separation between low-level functions and high-level functions relying on the ImGui context.
-- Also see imgui_draw.cpp for some more which have been reworked to not rely on ImGui:: context.
-------------------------------------------------------------------------------

--- @param text     ImString
--- @param text_end int?
--- @return int # Exclusive upper bound

function ImGui.FindRenderedTextEnd(text, text_end)
    local text_display_end = 1
    local text_len = #text
    if not text_end then
        text_end = text_len + 1
    end

    text_display_end = ImMemchr(text, "##", 1) or text_end
    text_display_end = math.min(text_display_end, text_end) -- [Luau] scalar ImMin()

    return text_display_end
end

-- Internal ImGui functions to render text
-- RenderText***() functions calls ImDrawList::AddText() calls ImBitmapFont::RenderText()
--- @param pos                  ImVec2
--- @param text                 string
--- @param text_begin           int?
--- @param text_end             int?
--- @param hide_text_after_hash bool?  # true by default

function ImGui.RenderText(pos, text, text_begin, text_end, hide_text_after_hash)
    if text_begin           == nil then text_begin = 1 end
    if hide_text_after_hash == nil then hide_text_after_hash = true end

    local g = GImGui
    local window = g.CurrentWindow

    -- Hide anything after a '##' string
    local text_display_end
    if hide_text_after_hash then
        text_display_end = ImGui.FindRenderedTextEnd(text, text_end)
    else
        if text_end == nil then
            text_end = #text + 1 -- FIXME-OPT (not reached by our internal calls)
        end
        text_display_end = text_end
    end

    if text ~= "" and text_display_end > 1 then
        window.DrawList:AddText(g.Font, g.FontSize, pos, ImGui.GetColorU32(ImGuiCol.Text), text, text_begin, text_display_end, 0.0)
        if g.LogEnabled then
            -- ImGui.LogRenderedText(&pos, text, text_display_end);
        end
    end
end

--- @param pos        ImVec2
--- @param text       string
--- @param text_end   int?
--- @param wrap_width float
function ImGui.RenderTextWrapped(pos, text, text_end, wrap_width)
    local g = GImGui
    local window = g.CurrentWindow

    if text_end == nil then
        text_end = #text + 1 -- FIXME-OPT (not reached by our internal calls)
    end

    if text ~= "" then
        window.DrawList:AddText(g.Font, g.FontSize, pos, ImGui.GetColorU32(ImGuiCol.Text), text, 1, text_end, wrap_width)
    end
end

-- Default clip_rect uses (pos_min,pos_max)
-- Handle clipping on CPU immediately (vs typically let the GPU clip the triangles that are overlapping the clipping rectangle edges)
-- FIXME-OPT: Since we have or calculate text_size we could coarse clip whole block immediately, especially for text above draw_list->DrawList.
-- Effectively as this is called from widget doing their own coarse clipping it's not very valuable presently. Next time function will take
-- better advantage of the render function taking size into account for coarse clipping.
-- DOES NOT CALL LogRenderedText(), unlike RenderTextClipped!!!
--- @param draw_list           ImDrawList
--- @param pos_min             ImVec2
--- @param pos_max             ImVec2
--- @param text                string
--- @param text_begin          int
--- @param text_display_end    int
--- @param text_size_if_known? ImVec2
--- @param align?              ImVec2
--- @param clip_rect?          ImRect
local RenderTextClipped_align0 = ImVec2(0, 0) -- [Luau] shared read-only default
local RenderTextClippedEx_pos = ImVec2()      -- [Luau] scratch: AddText() only reads pos
local RenderTextClippedEx_fine_clip = ImVec4() -- [Luau] scratch: AddText() only reads it


function ImGui.RenderTextClippedEx(draw_list, pos_min, pos_max, text, text_begin, text_display_end, text_size_if_known, align, clip_rect)
    if not align then align = RenderTextClipped_align0 end

    -- Perform CPU side clipping for single clipped element to avoid using scissor state
    local pos = RenderTextClippedEx_pos
    pos.x = pos_min.x; pos.y = pos_min.y

    local text_size = text_size_if_known or ImGui.CalcTextSize(text, text_display_end, false, 0.0)

    local clip_min = clip_rect and clip_rect.Min or pos_min
    local clip_max = clip_rect and clip_rect.Max or pos_max
    local need_clipping = (pos.x + text_size.x >= clip_max.x) or (pos.y + text_size.y >= clip_max.y)
    if (clip_rect) then -- If we had no explicit clipping rectangle then pos==clip_min
        need_clipping = need_clipping or ((pos.x < clip_min.x) or (pos.y < clip_min.y))
    end

    -- Align whole block. We should defer that to the better rendering function when we'll have support for individual line alignment.
    if (align.x > 0.0) then pos.x = math.max(pos.x, pos.x + (pos_max.x - pos.x - text_size.x) * align.x) end
    if (align.y > 0.0) then pos.y = math.max(pos.y, pos.y + (pos_max.y - pos.y - text_size.y) * align.y) end

    -- Render
    if (need_clipping) then
        local fine_clip_rect = RenderTextClippedEx_fine_clip
        fine_clip_rect.x = clip_min.x; fine_clip_rect.y = clip_min.y; fine_clip_rect.z = clip_max.x; fine_clip_rect.w = clip_max.y
        draw_list:AddText(nil, 0.0, pos, ImGui.GetColorU32(ImGuiCol.Text), text, text_begin, text_display_end, 0.0, fine_clip_rect)
    else
        draw_list:AddText(nil, 0.0, pos, ImGui.GetColorU32(ImGuiCol.Text), text, text_begin, text_display_end, 0.0, nil)
    end
end

--- @param pos_min             ImVec2
--- @param pos_max             ImVec2
--- @param text                string
--- @param text_end?           int
--- @param text_size_if_known? ImVec2
--- @param align?              ImVec2
--- @param clip_rect?          ImRect
function ImGui.RenderTextClipped(pos_min, pos_max, text, text_end, text_size_if_known, align, clip_rect)
    if not align then align = RenderTextClipped_align0 end

    -- Hide anything after a '##' string
    local text_display_end = ImGui.FindRenderedTextEnd(text, text_end)
    local text_len = text_display_end - 1

    if text_len == 0 then
        return
    end

    local g = GImGui
    local window = g.CurrentWindow
    ImGui.RenderTextClippedEx(window.DrawList, pos_min, pos_max, text, 1, text_display_end, text_size_if_known, align, clip_rect)
    -- if (g.LogEnabled)
    --     ImGui.LogRenderedText(&pos_min, text, text_display_end);
end

--- @param bb        ImRect
--- @param id        ImGuiID
--- @param flags?    ImGuiNavRenderCursorFlags
--- @param rounding? float

function ImGui.RenderNavCursor(bb, id, flags, rounding)
    if flags    == nil then flags    = ImGuiNavRenderCursorFlags.None end
    if rounding == nil then rounding = -1.0 end

    local g = GImGui
    if id ~= g.NavId then
        return
    end
    if not g.NavCursorVisible and bit32.band(flags, ImGuiNavRenderCursorFlags.AlwaysDraw) == 0 then
        return
    end
    if id == g.LastItemData.ID and bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.NoNav) ~= 0 then
        return
    end

    -- We don't early out on 'window.Flags & ImGuiWindowFlags.NoNavInputs' because it would be inconsistent with
    -- other code directly checking NavCursorVisible. Instead we aim for NavCursorVisible to always be false.
    local window = g.CurrentWindow
    if window.DC.NavHideHighlightOneFrame then
        return
    end

    if rounding < 0.0 then
        rounding = g.Style.FrameRounding
    end

    local display_rect = ImRect()
    ImRect_Copy(display_rect, bb)
    display_rect:ClipWith(window.ClipRect)
    local scale_factor = ImGui.GetScale() -- FIXME-DPI
    local thickness = ImTrunc(ImMax(2.0, 1.5 * scale_factor))
    if bit32.band(flags, ImGuiNavRenderCursorFlags.Compact) ~= 0 then
        window.DrawList:AddRect(display_rect.Min, display_rect.Max, ImGui.GetColorU32(ImGuiCol.NavCursor), rounding, thickness)
    else
        local distance = ImTrunc(3.0 + thickness * 0.5)
        display_rect:Expand(ImVec2(distance, distance))
        local fully_visible = window.ClipRect:Contains(display_rect)
        if not fully_visible then
            window.DrawList:PushClipRect(display_rect.Min, display_rect.Max)
        end
        window.DrawList:AddRect(display_rect.Min, display_rect.Max, ImGui.GetColorU32(ImGuiCol.NavCursor), rounding, thickness)
        if not fully_visible then
            window.DrawList:PopClipRect()
        end
    end
end

do --[[ImGui.RenderMouseCursor]]

local offset = ImVec2()
local size   = ImVec2()
local uv_border = {ImVec2(), ImVec2()}
local uv_fill   = {ImVec2(), ImVec2()}

--- @param base_pos     ImVec2
--- @param base_scale   float
--- @param mouse_cursor ImGuiMouseCursor
--- @param col_fill     ImU32
--- @param col_border   ImU32
--- @param col_shadow   ImU32
function ImGui.RenderMouseCursor(base_pos, base_scale, mouse_cursor, col_fill, col_border, col_shadow)
    local g = GImGui
    if mouse_cursor <= ImGuiMouseCursor.None or mouse_cursor >= ImGuiMouseCursor.COUNT then -- We intentionally accept out of bound values.
        mouse_cursor = ImGuiMouseCursor.Arrow
    end
    local font_atlas = g.DrawListSharedData.FontAtlas

    for _, viewport in g.Viewports:iter() do
        repeat
        -- We scale cursor with current viewport/monitor, however Windows 10 for its own hardware cursor seems to be using a different scale factor.
        if not ImFontAtlasGetMouseCursorTexData(font_atlas, mouse_cursor, offset, size, uv_border, uv_fill) then
            break
        end

        local pos = base_pos - offset
        local scale = base_scale * viewport.DpiScale
        if not viewport:GetMainRect():Overlaps(ImRect(pos, pos + ImVec2(size.x + 2, size.y + 2) * scale)) then
            break
        end

        local draw_list = ImGui.GetForegroundDrawList(viewport)
        local tex_ref = font_atlas.TexRef
        draw_list:PushTexture(tex_ref);
        draw_list:AddImage(tex_ref, pos + ImVec2(1, 0) * scale, pos + (ImVec2(1, 0) + size) * scale, uv_fill[1], uv_fill[2], col_shadow)
        draw_list:AddImage(tex_ref, pos + ImVec2(2, 0) * scale, pos + (ImVec2(2, 0) + size) * scale, uv_fill[1], uv_fill[2], col_shadow)
        draw_list:AddImage(tex_ref, pos,                        pos + size * scale,                  uv_fill[1], uv_fill[2], col_border)
        draw_list:AddImage(tex_ref, pos,                        pos + size * scale,                  uv_border[1], uv_border[2], col_fill)
        if mouse_cursor == ImGuiMouseCursor.Wait or mouse_cursor == ImGuiMouseCursor.Progress then
            local a_min = ImFmod(g.Time * 5.0, 2.0 * IM_PI)
            local a_max = a_min + IM_PI * 1.65
            draw_list:PathArcTo(pos + ImVec2(14, -1) * scale, 6.0 * scale, a_min, a_max)
            draw_list:PathStroke(col_fill, 3.0 * scale)
        end
        draw_list:PopTexture()

        until true
    end
end

end

-- Another overly complex function until we reorganize everything into a nice all-in-one helper.
-- This is made more complex because we have dissociated the layout rectangle (pos_min..pos_max) from 'ellipsis_max_x' which may be beyond it.
-- This is because in the context of tabs we selectively hide part of the text when the Close Button appears, but we don't want the ellipsis to move.
-- (BREAKING) On 2025/04/16 we removed the 'float clip_max_x' parameters which was preceding 'float ellipsis_max' and was the same value for 99% of users.
--- @param draw_list           ImDrawList
--- @param pos_min             ImVec2
--- @param pos_max             ImVec2
--- @param ellipsis_max_x      float
--- @param text                string
--- @param text_end_full?      int
--- @param text_size_if_known? ImVec2
function ImGui.RenderTextEllipsis(draw_list, pos_min, pos_max, ellipsis_max_x, text, text_end_full, text_size_if_known)
    local g = GImGui

    if text_end_full == nil then
        text_end_full = ImGui.FindRenderedTextEnd(text)
    end

    local text_size
    if text_size_if_known then
        text_size = ImVec2()
        ImVec2_Copy(text_size, text_size_if_known)
    else
        text_size = ImGui.CalcTextSize(text, text_end_full, false, 0.0)
    end

    -- draw_list:AddLineV(pos_max.x, pos_min.y - 4, pos_max.y + 6, IM_COL32(0, 0, 255, 255))
    -- draw_list:AddLineV(ellipsis_max_x, pos_min.y - 2, pos_max.y + 3, IM_COL32(0, 255, 0, 255))

    -- FIXME: We could technically remove (last_glyph->AdvanceX - last_glyph->X1) from text_size.x here and save a few pixels.
    if text_size.x > pos_max.x - pos_min.x then
        -- Hello wo...
        -- |       |   |
        -- min   max   ellipsis_max
        --          <-> this is generally some padding value

        local font = draw_list._Data.Font
        local font_size = draw_list._Data.FontSize
        local font_scale = draw_list._Data.FontScale
        local text_end_ellipsis = nil
        local baked = font:GetFontBaked(font_size)
        local ellipsis_width = baked:GetCharAdvance(font.EllipsisChar) * font_scale

        -- We can now claim the space between pos_max.x and ellipsis_max.x
        local text_avail_width = ImMax((ImMax(pos_max.x, ellipsis_max_x) - ellipsis_width) - pos_min.x, 1.0)
        local text_size_clipped
        text_size_clipped, text_end_ellipsis = font:CalcTextSizeA(font_size, text_avail_width, 0.0, text, 1, text_end_full)
        local text_size_clipped_x = text_size_clipped.x

        -- Render text, render ellipsis
        ImGui.RenderTextClippedEx(draw_list, pos_min, pos_max, text, 1, text_end_ellipsis, text_size, ImVec2(0.0, 0.0))
        local cpu_fine_clip_rect = ImVec4(pos_min.x, pos_min.y, pos_max.x, pos_max.y)
        local ellipsis_pos = ImTrunc(ImVec2(pos_min.x + text_size_clipped_x, pos_min.y))
        font:RenderChar(draw_list, font_size, ellipsis_pos, ImGui.GetColorU32(ImGuiCol.Text), font.EllipsisChar, cpu_fine_clip_rect)
    else
        ImGui.RenderTextClippedEx(draw_list, pos_min, pos_max, text, 1, text_end_full, text_size, ImVec2(0.0, 0.0))
    end

    if g.LogEnabled then
        ImGui.LogRenderedText(pos_min, text, text_end_full)
    end
end

-- Render a rectangle shaped with optional rounding and borders
--- @param p_min     ImVec2
--- @param p_max     ImVec2
--- @param fill_col  ImU32
--- @param borders?  bool
--- @param rounding? float

function ImGui.RenderFrame(p_min, p_max, fill_col, borders, rounding)
    if borders  == nil then borders  = true end
    if rounding == nil then rounding = 0.0 end

    local g = GImGui
    local window = g.CurrentWindow

    window.DrawList:AddRectFilled(p_min, p_max, fill_col, rounding)

    local border_size = g.Style.FrameBorderSize
    if borders and border_size > 0 then
        window.DrawList:AddRect(p_min + ImVec2(1, 1), p_max + ImVec2(1, 1), ImGui.GetColorU32(ImGuiCol.BorderShadow), rounding, border_size, 0)
        window.DrawList:AddRect(p_min, p_max, ImGui.GetColorU32(ImGuiCol.Border), rounding, border_size, 0)
    end
end

--- @param p_min    ImVec2
--- @param p_max    ImVec2
--- @param rounding float

function ImGui.RenderFrameBorder(p_min, p_max, rounding)
    local g = GImGui
    local window = g.CurrentWindow
    local border_size = g.Style.FrameBorderSize
    if border_size > 0.0 then
        window.DrawList:AddRect(p_min + ImVec2(1, 1), p_max + ImVec2(1, 1), ImGui.GetColorU32(ImGuiCol.BorderShadow), rounding, border_size, 0)
        window.DrawList:AddRect(p_min, p_max, ImGui.GetColorU32(ImGuiCol.Border), rounding, border_size, 0)
    end
end

--- @param bb       ImRect
--- @param col      ImU32
--- @param rounding float
function ImGui.RenderColorComponentMarker(bb, col, rounding)
    if bb.Min.x + 1 >= bb.Max.x then
        return
    end
    local g = GImGui
    local window = g.CurrentWindow
    ImGui.RenderRectFilledInRangeH(window.DrawList, bb, col, bb.Min.x, ImMin(bb.Min.x + g.Style.ColorMarkerSize, bb.Max.x), rounding)
end

--- @param window      ImGuiWindow
--- @param border_n    int
--- @param border_col  ImU32
--- @param border_size float
local function RenderWindowOuterSingleBorder(window, border_n, border_col, border_size)
    local def = ImGuiResizeBorderDef[border_n + 1]
    local rounding = window.WindowRounding
    local border_r = GetResizeBorderRect(window, border_n, rounding, 0.0)
    window.DrawList:PathArcTo(ImLerp(border_r.Min, border_r.Max, def.SegmentN1) + ImVec2(0.5, 0.5) + def.InnerDir * rounding, rounding, def.OuterAngle - IM_PI * 0.25, def.OuterAngle)
    window.DrawList:PathArcTo(ImLerp(border_r.Min, border_r.Max, def.SegmentN2) + ImVec2(0.5, 0.5) + def.InnerDir * rounding, rounding, def.OuterAngle, def.OuterAngle + IM_PI * 0.25)
    window.DrawList:PathStroke(border_col, border_size)
end

local function RenderWindowOuterBorders(window)
    local g = GImGui
    local border_size = window.WindowBorderSize
    local border_col = ImGui.GetColorU32(ImGuiCol.Border)
    if border_size > 0.0 and (bit32.band(window.Flags, ImGuiWindowFlags.NoBackground) == 0) then
        window.DrawList:AddRect(window.Pos, window.Pos + window.Size, border_col, window.WindowRounding, window.WindowBorderSize, 0)
    elseif border_size > 0.0 then
        if bit32.band(window.ChildFlags, ImGuiChildFlags.ResizeX) ~= 0 then -- Similar code as 'resize_border_mask' computation in UpdateWindowManualResize() but we specifically only always draw explicit child resize border.
            RenderWindowOuterSingleBorder(window, 1, border_col, border_size)
        end
        if bit32.band(window.ChildFlags, ImGuiChildFlags.ResizeY) ~= 0 then
            RenderWindowOuterSingleBorder(window, 3, border_col, border_size)
        end
    end

    if window.ResizeBorderHovered ~= -1 or window.ResizeBorderHeld ~= -1 then
        local border_n = (window.ResizeBorderHeld ~= -1) and window.ResizeBorderHeld or window.ResizeBorderHovered
        local border_col_resizing = ImGui.GetColorU32((window.ResizeBorderHeld ~= -1) and ImGuiCol.SeparatorActive or ImGuiCol.SeparatorHovered)
        RenderWindowOuterSingleBorder(window, border_n, border_col_resizing, ImMax(2.0, window.WindowBorderSize)) -- Thicker than usual
    end

    if g.Style.FrameBorderSize > 0 and (bit32.band(window.Flags, ImGuiWindowFlags.NoTitleBar) == 0) and not window.DockIsActive then
        local y = window.Pos.y + window.TitleBarHeight - 1
        window.DrawList:AddLineH(window.Pos.x + border_size * 0.5, window.Pos.x + window.Size.x - border_size * 0.5, y, border_col, g.Style.FrameBorderSize)
    end
end

-- Draw background and borders
-- Draw and handle scrollbars
--- @param window                          ImGuiWindow
--- @param title_bar_rect                  ImRect
--- @param title_bar_is_highlight          bool
--- @param handle_borders_and_resize_grips bool
--- @param resize_grip_col                 ImU32[]
--- @param resize_grip_draw_size           float
local function RenderWindowDecorations(window, title_bar_rect, title_bar_is_highlight, handle_borders_and_resize_grips, resize_grip_col, resize_grip_draw_size)
    local g = GImGui
    local style = g.Style
    local flags = window.Flags

    -- Draw window + handle manual resize
    -- As we highlight the title bar when want_focus is set, multiple reappearing windows will have their title bar highlighted on their reappearing frame.
    local window_rounding = window.WindowRounding
    local window_border_size = window.WindowBorderSize

    if window.Collapsed then
        -- Title bar only
        local backup_border_size = style.FrameBorderSize
        g.Style.FrameBorderSize = window.WindowBorderSize

        local title_bar_col = ImGui.GetColorU32((title_bar_is_highlight and g.NavCursorVisible) and ImGuiCol.TitleBgActive or ImGuiCol.TitleBgCollapsed)
        ImGui.RenderFrame(title_bar_rect.Min, title_bar_rect.Max, title_bar_col, true, window_rounding)
        g.Style.FrameBorderSize = backup_border_size
    else
        -- Window background
        if bit32.band(flags, ImGuiWindowFlags.NoBackground) == 0 then
            local bg_col = ImGui.GetColorU32(GetWindowBgColorIdx(window))
            -- Adjust alpha. For docking
            local override_alpha = false
            local alpha = 1.0

            if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasBgAlpha) ~= 0 then
                alpha = g.NextWindowData.BgAlphaVal
                override_alpha = true
            end

            if override_alpha then
                bg_col = bit32.bor(bit32.band(bg_col, bit32.bnot(IM_COL32_A_MASK)), bit32.lshift(IM_F32_TO_INT8_SAT(alpha), IM_COL32_A_SHIFT))
            end

            -- Render, for docked windows and host windows we ensure BG goes before decorations
            if window.DockIsActive then window.DockNode.LastBgColor = bg_col end
            if bit32.band(flags, ImGuiWindowFlags.DockNodeHost) ~= 0 then bg_col = 0 end

            if bit32.band(bg_col, IM_COL32_A_MASK) ~= 0 then
                local bg_rect = ImRect(window.Pos + ImVec2(0, window.TitleBarHeight), window.Pos + window.Size)
                local bg_rounding_flags
                if window.DockIsActive then
                    bg_rounding_flags = ImGui.CalcRoundingFlagsForRectInRect(bg_rect, window.DockNode.HostWindow:Rect(), 0.0)
                else
                    bg_rounding_flags = (bit32.band(flags, ImGuiWindowFlags.NoTitleBar) ~= 0) and ImDrawFlags.RoundCornersAll or ImDrawFlags.RoundCornersBottom
                end
                local bg_draw_list = window.DockIsActive and window.DockNode.HostWindow.DrawList or window.DrawList
                if window.DockIsActive then bg_draw_list:ChannelsSetCurrent(0) end
                bg_draw_list:AddRectFilled(bg_rect.Min, bg_rect.Max, bg_col, window_rounding, bg_rounding_flags)
                if window.DockIsActive then bg_draw_list:ChannelsSetCurrent(1) end
            end
        end
        if window.DockIsActive then window.DockNode.IsBgDrawnThisFrame = true end

        -- Title bar
        -- (when docked, DockNode are drawing their own title bar. Individual windows however do NOT set the _NoTitleBar flag,
        -- in order for their pos/size to be matching their undocking state.)
        if bit32.band(flags, ImGuiWindowFlags.NoTitleBar) == 0 and not window.DockIsActive then
            local title_bar_col = ImGui.GetColorU32(title_bar_is_highlight and ImGuiCol.TitleBgActive or ImGuiCol.TitleBg)
            window.DrawList:AddRectFilled(title_bar_rect.Min, title_bar_rect.Max, title_bar_col, window_rounding, ImDrawFlags.RoundCornersTop)
        end

        -- Menu bar
        if bit32.band(flags, ImGuiWindowFlags.MenuBar) ~= 0 then
            local menu_bar_rect = window:MenuBarRect()
            menu_bar_rect:ClipWith(window:Rect()) -- Soft clipping, in particular child window don't have minimum size covering the menu bar so this is useful for them.
            window.DrawList:AddRectFilled(menu_bar_rect.Min, menu_bar_rect.Max, ImGui.GetColorU32(ImGuiCol.MenuBarBg), (bit32.band(flags, ImGuiWindowFlags.NoTitleBar) ~= 0) and window_rounding or 0.0, ImDrawFlags.RoundCornersTop)
            if style.FrameBorderSize > 0.0 and menu_bar_rect.Max.y < window.Pos.y + window.Size.y then
                window.DrawList:AddLineH(menu_bar_rect.Min.x + window_border_size * 0.5, menu_bar_rect.Max.x - window_border_size * 0.5, menu_bar_rect.Max.y, ImGui.GetColorU32(ImGuiCol.Border), style.FrameBorderSize)
            end
        end

        -- Docking: Unhide tab bar (small triangle in the corner), drag from small triangle to quickly undock
        local node = window.DockNode
        if window.DockIsActive and node:IsHiddenTabBar() and not node:IsNoTabBar() then
            local unhide_sz_draw = ImTrunc(g.FontSize * 0.70)
            local unhide_sz_hit = ImTrunc(g.FontSize * 0.55)
            local p = node.Pos
            local r = ImRect(p, p + ImVec2(unhide_sz_hit, unhide_sz_hit))
            local unhide_id = window:GetID("#UNHIDE")
            ImGui.KeepAliveID(unhide_id)
            local pressed, hovered, held = ImGui.ButtonBehavior(r, unhide_id, ImGuiButtonFlags.FlattenChildren)
            if pressed then
                node.WantHiddenTabBarToggle = true
            elseif held and ImGui.IsMouseDragging(0) then
                ImGui.StartMouseMovingWindowOrNode(window, node, true) -- Undock from tab-bar triangle = same as window/collapse menu button
            end

            -- FIXME-DOCK: Ideally we'd use ImGuiCol.TitleBgActive/ImGuiCol.TitleBg here, but neither is guaranteed to be visible enough at this sort of size..
            local col = ImGui.GetColorU32(((held and hovered) or (node.IsFocused and not hovered)) and ImGuiCol.ButtonActive or (hovered and ImGuiCol.ButtonHovered or ImGuiCol.Button))
            window.DrawList:AddTriangleFilled(p, p + ImVec2(unhide_sz_draw, 0.0), p + ImVec2(0.0, unhide_sz_draw), col)
        end

        -- Scrollbars
        if window.ScrollbarX then
            ImGui.Scrollbar(ImGuiAxis.X)
        end
        if window.ScrollbarY then
            ImGui.Scrollbar(ImGuiAxis.Y)
        end

        -- Render resize grips (after their input handling so we don't have a frame of latency)
        if handle_borders_and_resize_grips and (bit32.band(flags, ImGuiWindowFlags.NoResize) == 0) then
            for resize_grip_n = 1, #ImGuiResizeGripDef do
                repeat
                local col = resize_grip_col[resize_grip_n]
                if bit32.band(col, IM_COL32_A_MASK) == 0 then
                    break
                end

                local grip = ImGuiResizeGripDef[resize_grip_n]
                local corner = ImLerp(window.Pos, window.Pos + window.Size, grip.CornerPosN)
                local border_inner = IM_ROUND(window_border_size * 0.5)
                window.DrawList:PathLineTo(corner + grip.InnerDir * ((resize_grip_n % 2 == 0) and ImVec2(border_inner, resize_grip_draw_size) or ImVec2(resize_grip_draw_size, border_inner)))
                window.DrawList:PathLineTo(corner + grip.InnerDir * ((resize_grip_n % 2 == 0) and ImVec2(resize_grip_draw_size, border_inner) or ImVec2(border_inner, resize_grip_draw_size)))
                window.DrawList:PathArcToFast(ImVec2(corner.x + grip.InnerDir.x * (window_rounding + border_inner), corner.y + grip.InnerDir.y * (window_rounding + border_inner)), window_rounding, grip.AngleMin12, grip.AngleMax12)
                window.DrawList:PathFillConvex(col)

                until true
            end
        end

        -- Borders (for dock node host they will be rendered over after the tab bar)
        if handle_borders_and_resize_grips and not window.DockNodeAsHost then
            RenderWindowOuterBorders(window)
        end
    end

    window.DC.NavLayerCurrent = ImGuiNavLayer.Main
end
ImGui.RenderWindowOuterBorders = RenderWindowOuterBorders

-- When inside a dock node, this is handled in DockNodeCalcTabBarLayout() instead.
-- Render title text, collapse button, close button
-- Returns the updated 'open' value (nil when there is no close button)
--- @param window         ImGuiWindow
--- @param title_bar_rect ImRect
--- @param name           string
--- @param open           bool?
--- @return bool?
local function RenderWindowTitleBarContents(window, title_bar_rect, name, open)
    local g = GImGui
    local style = g.Style
    local flags = window.Flags

    local has_close_button = (open ~= nil)
    local has_collapse_button = bit32.band(flags, ImGuiWindowFlags.NoCollapse) == 0 and (style.WindowMenuButtonPosition ~= ImGuiDir.None)

    -- Close & Collapse button are on the Menu NavLayer and don't default focus (unless there's nothing else on that layer)
    -- FIXME-NAV: Might want (or not?) to set the equivalent of ImGuiButtonFlags.NoNavFocus so that mouse clicks on standard title bar items don't necessarily set nav/keyboard ref?
    local item_flags_backup = g.CurrentItemFlags
    g.CurrentItemFlags = bit32.bor(g.CurrentItemFlags, ImGuiItemFlags.NoNavDefaultFocus)
    window.DC.NavLayerCurrent = ImGuiNavLayer.Menu

    -- Layout buttons
    -- FIXME: Would be nice to generalize the subtleties expressed here into reusable code.
    local pad_l = g.Style.FramePadding.x
    local pad_r = g.Style.FramePadding.x
    local button_sz = g.FontSize
    local close_button_pos
    local collapse_button_pos
    if has_close_button then
        close_button_pos = ImVec2(title_bar_rect.Max.x - pad_r - button_sz, title_bar_rect.Min.y + style.FramePadding.y)
        pad_r = pad_r + button_sz + style.ItemInnerSpacing.x
    end
    if has_collapse_button and style.WindowMenuButtonPosition == ImGuiDir.Right then
        collapse_button_pos = ImVec2(title_bar_rect.Max.x - pad_r - button_sz, title_bar_rect.Min.y + style.FramePadding.y)
        pad_r = pad_r + button_sz + style.ItemInnerSpacing.x
    end
    if has_collapse_button and style.WindowMenuButtonPosition == ImGuiDir.Left then
        collapse_button_pos = ImVec2(title_bar_rect.Min.x + pad_l, title_bar_rect.Min.y + style.FramePadding.y)
        pad_l = pad_l + button_sz + style.ItemInnerSpacing.x
    end

    -- Collapse button (submitting first so it gets priority when choosing a navigation init fallback)
    if has_collapse_button then
        if ImGui.CollapseButton(window:GetID("#COLLAPSE"), collapse_button_pos) then
            window.WantCollapseToggle = true -- Defer actual collapsing to next frame as we are too far in the Begin() function
        end
    end

    -- Close button
    if has_close_button then
        local backup_item_flags = g.CurrentItemFlags
        g.CurrentItemFlags = bit32.bor(g.CurrentItemFlags, ImGuiItemFlags.NoFocus)
        if ImGui.CloseButton(window:GetID("#CLOSE"), close_button_pos) then
            open = false
        end
        g.CurrentItemFlags = backup_item_flags
    end

    window.DC.NavLayerCurrent = ImGuiNavLayer.Main
    g.CurrentItemFlags = item_flags_backup

    -- Title bar text (with: horizontal alignment, avoiding collapse/close button, optional "unsaved document" marker)
    -- FIXME: Refactor text alignment facilities along with RenderText helpers, this is WAY too much messy code..
    local marker_size_x = (bit32.band(flags, ImGuiWindowFlags.UnsavedDocument) ~= 0) and (button_sz * 0.80) or 0.0
    local text_size = ImGui.CalcTextSize(name, nil, true) + ImVec2(marker_size_x, 0.0)

    -- As a nice touch we try to ensure that centered title text doesn't get affected by visibility of Close/Collapse button,
    -- while uncentered title text will still reach edges correctly.
    if (pad_l > style.FramePadding.x) then
        pad_l = pad_l + g.Style.ItemInnerSpacing.x
    end
    if (pad_r > style.FramePadding.x) then
        pad_r = pad_r + g.Style.ItemInnerSpacing.x
    end
    if (style.WindowTitleAlign.x > 0.0 and style.WindowTitleAlign.x < 1.0) then
        local centerness = ImSaturate(1.0 - ImFabs(style.WindowTitleAlign.x - 0.5) * 2.0) -- 0.0 on either edges, 1.0 on center
        local pad_extend = ImMin(ImMax(pad_l, pad_r), title_bar_rect:GetWidth() - pad_l - pad_r - text_size.x)
        pad_l = ImMax(pad_l, pad_extend * centerness)
        pad_r = ImMax(pad_r, pad_extend * centerness)
    end

    local layout_r = ImRect(title_bar_rect.Min.x + pad_l, title_bar_rect.Min.y, title_bar_rect.Max.x - pad_r, title_bar_rect.Max.y)
    local clip_r = ImRect(layout_r.Min.x, layout_r.Min.y, ImMin(layout_r.Max.x + g.Style.ItemInnerSpacing.x, title_bar_rect.Max.x), layout_r.Max.y)

    if bit32.band(flags, ImGuiWindowFlags.UnsavedDocument) ~= 0 then
        local marker_pos = ImVec2()
        marker_pos.x = ImClamp(layout_r.Min.x + (layout_r:GetWidth() - text_size.x) * style.WindowTitleAlign.x + text_size.x, layout_r.Min.x, layout_r.Max.x)
        marker_pos.y = (layout_r.Min.y + layout_r.Max.y) * 0.5
        if marker_pos.x > layout_r.Min.x then
            ImGui.RenderBullet(window.DrawList, marker_pos, ImGui.GetColorU32(ImGuiCol.UnsavedMarker))
            clip_r.Max.x = ImMin(clip_r.Max.x, marker_pos.x - math.floor(marker_size_x * 0.5))
        end
    end
    -- if (g.IO.KeyShift) window.DrawList:AddRect(layout_r.Min, layout_r.Max, IM_COL32(255, 128, 0, 255)) -- [DEBUG]
    -- if (g.IO.KeyCtrl) window.DrawList:AddRect(clip_r.Min, clip_r.Max, IM_COL32(255, 128, 0, 255)) -- [DEBUG]
    ImGui.RenderTextClipped(layout_r.Min, layout_r.Max, name, nil, text_size, style.WindowTitleAlign, clip_r)

    return open
end

--- @param window         ImGuiWindow
--- @param flags          ImGuiWindowFlags
--- @param parent_window? ImGuiWindow
function ImGui.UpdateWindowParentAndRootLinks(window, flags, parent_window)
    window.ParentWindow = parent_window
    window.RootWindow = window
    window.RootWindowPopupTree = window
    window.RootWindowDockTree = window
    window.RootWindowForTitleBarHighlight = window
    window.RootWindowForNav = window

    if parent_window and (bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0) and (bit32.band(flags, ImGuiWindowFlags.Tooltip) == 0) then
        window.RootWindowDockTree = parent_window.RootWindowDockTree
        if not window.DockIsActive and (bit32.band(parent_window.Flags, ImGuiWindowFlags.DockNodeHost) == 0) then
            window.RootWindow = parent_window.RootWindow
        end
    end
    if parent_window and (bit32.band(flags, ImGuiWindowFlags.Popup) ~= 0) then
        window.RootWindowPopupTree = parent_window.RootWindowPopupTree
    end
    if parent_window and (bit32.band(flags, ImGuiWindowFlags.Modal) == 0) and (bit32.band(flags, bit32.bor(ImGuiWindowFlags.ChildWindow, ImGuiWindowFlags.Popup, ImGuiWindowFlags.Tooltip)) ~= 0) then -- FIXME: simply use _NoTitleBar ?
        window.RootWindowForTitleBarHighlight = parent_window.RootWindowForTitleBarHighlight
    end

    while bit32.band(window.RootWindowForNav.ChildFlags, ImGuiChildFlags.NavFlattened) ~= 0 do
        IM_ASSERT(window.RootWindowForNav.ParentWindow ~= nil)
        window.RootWindowForNav = window.RootWindowForNav.ParentWindow
    end
end

-- [EXPERIMENTAL] Called by Begin(). NextWindowData is valid at this point.
-- This is designed as a toy/test-bed for
--- @param window ImGuiWindow
function ImGui.UpdateWindowSkipRefresh(window)
    local g = GImGui
    window.SkipRefresh = false

    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasRefreshPolicy) == 0 then
        return
    end

    if bit32.band(g.NextWindowData.RefreshFlagsVal, ImGuiWindowRefreshFlags.TryToAvoidRefresh) ~= 0 then
        -- [Port] SetNextWindowCached(): refresh on any change since the last refresh (and one frame after being busy)
        if g.NextWindowData.CacheKeySet then
            local function related(w) return w ~= nil and (w.RootWindow == window.RootWindow or ImGui.IsWindowWithinBeginStackOf(w.RootWindow, window)) end
            local busy = window.Appearing or window.Hidden or window.DockIsActive or related(g.HoveredWindow) or related(g.NavWindow) or related(g.ActiveIdWindow) or (g.MovingWindow ~= nil and related(g.MovingWindow))
            local c, key, ds, tex = window.CacheSnap, g.NextWindowData.CacheKeyVal, g.IO.DisplaySize, g.IO.Fonts.TexData
            if busy or c == nil or c.Busy or c.Key ~= key or c.Tex ~= tex or c.Collapsed ~= window.Collapsed
                or c.PosX ~= window.Pos.x or c.PosY ~= window.Pos.y or c.SizeX ~= window.SizeFull.x or c.SizeY ~= window.SizeFull.y
                or c.ScrollX ~= window.Scroll.x or c.ScrollY ~= window.Scroll.y or window.ScrollTarget.x < FLT_MAX or window.ScrollTarget.y < FLT_MAX
                or c.DisplayX ~= ds.x or c.DisplayY ~= ds.y then
                c = c or {}
                window.CacheSnap = c
                c.Busy, c.Key, c.Tex, c.Collapsed = busy, key, tex, window.Collapsed
                c.PosX, c.PosY, c.SizeX, c.SizeY = window.Pos.x, window.Pos.y, window.SizeFull.x, window.SizeFull.y
                c.ScrollX, c.ScrollY, c.DisplayX, c.DisplayY = window.Scroll.x, window.Scroll.y, ds.x, ds.y
                return
            end
            -- skip: widgets early-out on SkipItems and Begin() returns visible=false; End() restores it
            window.CacheSkipItemsBackup = window.SkipItems
            window.SkipItems = true
        end
        -- FIXME-IDLE: Tests for e.g. mouse clicks or keyboard while focused.
        if window.Appearing then -- If currently appearing
            return
        end
        if window.Hidden then -- If was hidden (previous frame)
            return
        end
        if bit32.band(g.NextWindowData.RefreshFlagsVal, ImGuiWindowRefreshFlags.RefreshOnHover) ~= 0 and g.HoveredWindow then
            if window.RootWindow == g.HoveredWindow.RootWindow or ImGui.IsWindowWithinBeginStackOf(g.HoveredWindow.RootWindow, window) then
                return
            end
        end
        if bit32.band(g.NextWindowData.RefreshFlagsVal, ImGuiWindowRefreshFlags.RefreshOnFocus) ~= 0 and g.NavWindow then
            if window.RootWindow == g.NavWindow.RootWindow or ImGui.IsWindowWithinBeginStackOf(g.NavWindow.RootWindow, window) then
                return
            end
        end
        window.DrawList = nil
        window.SkipRefresh = true
    end
end

--- @param window ImGuiWindow
local function SetWindowActiveForSkipRefresh(window)
    window.Active = true
    for _, child in window.DC.ChildWindows:iter() do
        if not child.Hidden then
            child.Active = true
            child.SkipRefresh = true
            SetWindowActiveForSkipRefresh(child)
        end
    end
end

--- @param window ImGuiWindow?
local function SetCurrentWindow(window)
    local g = GImGui
    --- @diagnostic disable-next-line
    g.CurrentWindow = window
    g.CurrentTable = (window and window.DC.CurrentTableIdx ~= -1) and g.Tables:GetByIndex(window.DC.CurrentTableIdx) or nil

    if window then
        if bit32.band(g.IO.BackendFlags, ImGuiBackendFlags.RendererHasTextures) ~= 0 then
            local viewport = window.Viewport
            g.FontRasterizerDensity = (viewport.FramebufferScale.x ~= 0.0) and viewport.FramebufferScale.x or g.IO.DisplayFramebufferScale.x
        end

        local backup_skip_items = window.SkipItems
        window.SkipItems = false
        ImGui.UpdateCurrentFontSize(0.0)
        window.SkipItems = backup_skip_items
        ImGui.NavUpdateCurrentWindowIsScrollPushableX()
    end
end

-- TODO:
function ImGui.GcCompactTransientMiscBuffers()
    local g = GImGui
    g.ItemFlagsStack:clear()
    g.GroupStack:clear()
    g.InputTextLineIndex:clear()
    ImGui.TableGcCompactSettings()
    for _, atlas in g.FontAtlases:iter() do
        atlas:CompactCache()
    end
end

-- Free up/compact internal window buffers, we can use this when a window becomes unused.
-- Not freed:
-- - ImGuiWindow, ImGuiWindowSettings, Name, StateStorage, ColumnsStorage (may hold useful data)
-- This should have no noticeable visual effect. When the window reappear however, expect new allocation/buffer growth/copy cost.
-- FIXME: Consider exposing of elaborating GC policy, e.g. being able to trim excessive ImDrawList gaps. (#9303)
--- @param window ImGuiWindow
function ImGui.GcCompactTransientWindowBuffers(window)
    window.MemoryCompacted = true
    window.MemoryDrawListIdxCapacity = ImMin(math.floor(window.DrawList.IdxBuffer.Size * 1.05), window.DrawList.IdxBuffer.Capacity)
    window.MemoryDrawListVtxCapacity = ImMin(math.floor(window.DrawList.VtxBuffer.Size * 1.05), window.DrawList.VtxBuffer.Capacity)
    window.IDStack:clear()
    window.DrawList:_ClearFreeMemory()
    window.DC.ChildWindows:clear()
    window.DC.ItemWidthStack:clear()
    window.DC.TextWrapPosStack:clear()
end

--- @param window ImGuiWindow
function ImGui.GcAwakeTransientWindowBuffers(window)
    -- We stored capacity of the ImDrawList buffer to reduce growth-caused allocation/copy when awakening.
    -- The other buffers tends to amortize much faster.
    window.MemoryCompacted = false
    window.DrawList.IdxBuffer:reserve(window.MemoryDrawListIdxCapacity)
    window.DrawList.VtxBuffer:reserve(window.MemoryDrawListVtxCapacity)
    window.MemoryDrawListIdxCapacity = 0
    window.MemoryDrawListVtxCapacity = 0
end

function ImGui.GetWindowWidth()
    local window = GImGui.CurrentWindow
    return window.Size.x
end

--- @param window ImGuiWindow
--- @param pos    ImVec2
--- @param cond?  ImGuiCond
function ImGui.SetWindowPos(window, pos, cond)
    -- Overloads: SetWindowPos(pos, cond) / SetWindowPos(name, pos, cond) / SetWindowPos(window, pos, cond)
    if type(window) == "string" then
        window = ImGui.FindWindowByName(window)
        if window == nil then return end
    elseif window.SetWindowPosAllowFlags == nil then
        window, pos, cond = ImGui.GetCurrentWindowRead(), window, pos
    end
    if cond == nil then cond = 0 end

    -- Test condition (NB: bit 0 is always true) and clear flags for next time
    if (cond ~= 0) and (bit32.band(window.SetWindowPosAllowFlags, cond) == 0) then
        return
    end

    IM_ASSERT(cond == 0 or ImIsPowerOfTwo(cond)) -- Make sure the user doesn't attempt to combine multiple condition flags.
    window.SetWindowPosAllowFlags = bit32.band(window.SetWindowPosAllowFlags, bit32.bnot(bit32.bor(ImGuiCond.Once, ImGuiCond.FirstUseEver, ImGuiCond.Appearing)))
    ImVec2_Copy(window.SetWindowPosVal, ImVec2(FLT_MAX, FLT_MAX))

    -- Set
    local old_pos = ImVec2()
    ImVec2_Copy(old_pos, window.Pos)

    window.Pos.x = ImTrunc(pos.x)
    window.Pos.y = ImTrunc(pos.y)

    local offset = window.Pos - old_pos

    if offset.x == 0 and offset.y == 0 then
        return
    end
    ImGui.MarkIniSettingsDirty(window)
    -- FIXME: share code with TranslateWindow(), need to confirm whether the 3 rect modified by TranslateWindow() are desirable here.
    ImVec2_Copy(window.DC.CursorPos, window.DC.CursorPos + offset)       -- As we happen to move the window while it is being appended to (which is a bad idea - will smear) let's at least offset the cursor
    ImVec2_Copy(window.DC.CursorMaxPos, window.DC.CursorMaxPos + offset) -- And more importantly we need to offset CursorMaxPos/CursorStartPos this so ContentSize calculation doesn't get affected.
    ImVec2_Copy(window.DC.IdealMaxPos, window.DC.IdealMaxPos + offset)
    ImVec2_Copy(window.DC.CursorStartPos, window.DC.CursorStartPos + offset)
end

--- @param window ImGuiWindow
--- @param size   ImVec2
--- @param cond?  ImGuiCond
function ImGui.SetWindowSize(window, size, cond)
    -- Overloads: SetWindowSize(size, cond) / SetWindowSize(name, size, cond) / SetWindowSize(window, size, cond)
    if type(window) == "string" then
        window = ImGui.FindWindowByName(window)
        if window == nil then return end
    elseif window.SetWindowSizeAllowFlags == nil then
        window, size, cond = GImGui.CurrentWindow, window, size
    end
    if cond == nil then cond = 0 end

    -- Test condition (NB: bit 0 is always true) and clear flags for next time
    if ((cond ~= 0) and bit32.band(window.SetWindowSizeAllowFlags, cond) == 0) then
        return
    end

    IM_ASSERT(cond == 0 or ImIsPowerOfTwo(cond)) -- Make sure the user doesn't attempt to combine multiple condition flags.
    window.SetWindowSizeAllowFlags = bit32.band(window.SetWindowSizeAllowFlags, bit32.bnot(bit32.bor(ImGuiCond.Once, ImGuiCond.FirstUseEver, ImGuiCond.Appearing)))

    -- Enable auto-fit (not done in BeginChild() path unless appearing or combined with ImGuiChildFlags.AlwaysAutoResize)
    if bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) == 0 or window.Appearing or bit32.band(window.ChildFlags, ImGuiChildFlags.AlwaysAutoResize) ~= 0 then
        window.AutoFitFramesX = (size.x <= 0.0) and 2 or 0
    end
    if bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) == 0 or window.Appearing or bit32.band(window.ChildFlags, ImGuiChildFlags.AlwaysAutoResize) ~= 0 then
        window.AutoFitFramesY = (size.y <= 0.0) and 2 or 0
    end

    -- Set
    local old_size_x, old_size_y = window.SizeFull.x, window.SizeFull.y

    if size.x <= 0.0 then
        window.AutoFitOnlyGrows = false
    else
        window.SizeFull.x = IM_TRUNC(size.x)
    end
    if size.y <= 0.0 then
        window.AutoFitOnlyGrows = false
    else
        window.SizeFull.y = IM_TRUNC(size.y)
    end
    if old_size_x ~= window.SizeFull.x or old_size_y ~= window.SizeFull.y then
        ImGui.MarkIniSettingsDirty(window)
    end
end

--- Overloads: SetWindowCollapsed(collapsed, cond) / SetWindowCollapsed(name, collapsed, cond) / SetWindowCollapsed(window, collapsed, cond)
function ImGui.SetWindowCollapsed(window, collapsed, cond)
    if type(window) == "string" then
        window = ImGui.FindWindowByName(window)
        if window == nil then return end
    elseif type(window) == "boolean" then
        window, collapsed, cond = GImGui.CurrentWindow, window, collapsed
    end
    if cond == nil then cond = 0 end
    -- Test condition (NB: bit 0 is always true) and clear flags for next time
    if cond ~= 0 and bit32.band(window.SetWindowCollapsedAllowFlags, cond) == 0 then
        return
    end
    window.SetWindowCollapsedAllowFlags = bit32.band(window.SetWindowCollapsedAllowFlags, bit32.bnot(bit32.bor(ImGuiCond.Once, ImGuiCond.FirstUseEver, ImGuiCond.Appearing)))

    -- Queue applying in Begin()
    if window.WantCollapseToggle then
        window.Collapsed = not window.Collapsed
    end
    window.WantCollapseToggle = (window.Collapsed ~= collapsed)
end

--- @param window ImGuiWindow
--- @param pos    ImVec2
--- @param size   ImVec2
function ImGui.SetWindowHitTestHole(window, pos, size)
    IM_ASSERT(window.HitTestHoleSize.x == 0) -- We don't support multiple holes/hit test filters
    window.HitTestHoleSize = ImVec2(math.floor(size.x), math.floor(size.y))
    window.HitTestHoleOffset = ImVec2(math.floor(pos.x - window.Pos.x), math.floor(pos.y - window.Pos.y))
end

function ImGui.IsWindowCollapsed()
    return ImGui.GetCurrentWindowRead().Collapsed
end

function ImGui.IsWindowAppearing()
    return ImGui.GetCurrentWindowRead().Appearing
end

function ImGui.GetWindowHeight()
    return GImGui.CurrentWindow.Size.y
end

--- @return ImVec2 # Ref, do not modify
function ImGui.GetWindowPos()
    return GImGui.CurrentWindow.Pos
end

--- @return ImVec2 # Ref, do not modify
function ImGui.GetWindowSize()
    return ImGui.GetCurrentWindowRead().Size
end

-- Overloads: SetWindowFocus() / SetWindowFocus(name). Passing nil name removes focus.
--- @param name? string
function ImGui.SetWindowFocus(...)
    if select("#", ...) == 0 then
        ImGui.FocusWindow(GImGui.CurrentWindow)
        return
    end
    local name = ...
    if name then
        local window = ImGui.FindWindowByName(name)
        if window then
            ImGui.FocusWindow(window)
        end
    else
        ImGui.FocusWindow(nil)
    end
end

--- @param window ImGuiWindow
function ImGui.SetWindowHiddenAndSkipItemsForCurrentFrame(window)
    window.Hidden = true
    window.SkipItems = true
    window.HiddenFramesCanSkipItems = 1
end

--- @param pos    ImVec2
--- @param cond?  ImGuiCond
--- @param pivot? ImVec2
function ImGui.SetNextWindowPos(pos, cond, pivot)
    if cond  == nil then cond  = 0            end
    if pivot == nil then pivot = ImVec2(0, 0) end

    local g = GImGui
    IM_ASSERT(cond == 0 or ImIsPowerOfTwo(cond)) -- Make sure the user doesn't attempt to combine multiple condition flags.

    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasPos)
    ImVec2_Copy(g.NextWindowData.PosVal, pos)
    ImVec2_Copy(g.NextWindowData.PosPivotVal, pivot)
    g.NextWindowData.PosCond = (cond ~= 0) and cond or ImGuiCond.Always
    g.NextWindowData.PosUndock = true
end

--- @param size  ImVec2
--- @param cond? ImGuiCond
function ImGui.SetNextWindowSize(size, cond)
    if cond == nil then cond = 0 end

    local g = GImGui
    IM_ASSERT(cond == 0 or ImIsPowerOfTwo(cond)) -- Make sure the user doesn't attempt to combine multiple condition flags.

    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasSize)
    ImVec2_Copy(g.NextWindowData.SizeVal, size)
    g.NextWindowData.SizeCond = (cond ~= 0) and cond or ImGuiCond.Always
end

-- For each axis:
-- - Use 0.0f as min or FLT_MAX as max if you don't want limits, e.g. size_min = (500.0f, 0.0f), size_max = (FLT_MAX, FLT_MAX) sets a minimum width.
-- - Use -1 for both min and max of same axis to preserve current size which itself is a constraint.
-- - See "Demo->Examples->Constrained-resizing window" for examples.
--- @param size_min                   ImVec2
--- @param size_max                   ImVec2
--- @param custom_callback?           function
--- @param custom_callback_user_data? any
function ImGui.SetNextWindowSizeConstraints(size_min, size_max, custom_callback, custom_callback_user_data)
    local g = GImGui
    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasSizeConstraint)
    g.NextWindowData.SizeConstraintRect = ImRect(size_min, size_max)
    g.NextWindowData.SizeCallback = custom_callback
    g.NextWindowData.SizeCallbackUserData = custom_callback_user_data
end

--- @param alpha float
function ImGui.SetNextWindowBgAlpha(alpha)
    local g = GImGui
    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasBgAlpha)
    g.NextWindowData.BgAlphaVal = alpha
end

function ImGui.GetWindowDrawList()
    local window = ImGui.GetCurrentWindow()
    return window.DrawList
end

function ImGui.GetFont()
    return GImGui.Font
end

-- Get current font size (= height in pixels) of current font, with global scale factors applied.
-- - Use style.FontSizeBase to get value before global scale factors.
-- - recap: ImGui.GetFontSize() == style.FontSizeBase * (style.FontScaleMain * style.FontScaleDpi * other_scaling_factors)
function ImGui.GetFontSize()
    return GImGui.FontSize
end

--- @return ImVec2
function ImGui.GetFontTexUvWhitePixel()
    return GImGui.DrawListSharedData.TexUvWhitePixel
end

-- This is a shortcut for not taking ownership of 100+ keys, frequently used by drag operations.
-- FIXME: It might be undesirable that this will likely disable KeyOwner-aware shortcuts systems. Consider a more fine-tuned version if needed?
function ImGui.SetActiveIdUsingAllKeyboardKeys()
    local g = GImGui
    IM_ASSERT(g.ActiveId ~= 0)
    g.ActiveIdUsingNavDirMask = (bit32.lshift(1, ImGuiDir.COUNT) - 1)
    g.ActiveIdUsingAllKeyboardKeys = true
    ImGui.NavMoveRequestCancel()
end

--- @return ImVec2 # Ref
function ImGui.GetItemRectMin()
    local g = GImGui
    return g.LastItemData.Rect.Min
end

--- @return ImVec2 # Ref
function ImGui.GetItemRectMax()
    local g = GImGui
    return g.LastItemData.Rect.Max
end

--- @param name         string
--- @param id           ImGuiID
--- @param size_arg     ImVec2
--- @param child_flags  ImGuiChildFlags
--- @param window_flags ImGuiWindowFlags
function ImGui.BeginChildEx(name, id, size_arg, child_flags, window_flags)
    local g = GImGui
    local parent_window = g.CurrentWindow
    IM_ASSERT(id ~= 0)
    if child_flags == nil then child_flags = 0 end
    if window_flags == nil then window_flags = 0 end
    if size_arg == nil then size_arg = ImVec2(0, 0) end

    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasChildFlags) ~= 0 then
        child_flags = bit32.band(bit32.bor(child_flags, g.NextWindowData.ChildFlagsSet), bit32.bnot(g.NextWindowData.ChildFlagsClear))
    end

    -- Sanity check as it is likely that some user will accidentally pass ImGuiWindowFlags into the ImGuiChildFlags argument.
    local ImGuiChildFlags_SupportedMask_ = bit32.bor(ImGuiChildFlags.Borders, ImGuiChildFlags.AlwaysUseWindowPadding, ImGuiChildFlags.ResizeX, ImGuiChildFlags.ResizeY, ImGuiChildFlags.AutoResizeX, ImGuiChildFlags.AutoResizeY, ImGuiChildFlags.AlwaysAutoResize, ImGuiChildFlags.FrameStyle, ImGuiChildFlags.NavFlattened)
    -- IM_UNUSED(ImGuiChildFlags_SupportedMask_)
    IM_ASSERT(bit32.band(child_flags, bit32.bnot(ImGuiChildFlags_SupportedMask_)) == 0, "Illegal ImGuiChildFlags value. Did you pass ImGuiWindowFlags values instead of ImGuiChildFlags?")
    IM_ASSERT(bit32.band(window_flags, ImGuiWindowFlags.AlwaysAutoResize) == 0, "Cannot specify ImGuiWindowFlags.AlwaysAutoResize for BeginChild(). Use ImGuiChildFlags.AlwaysAutoResize!")
    if bit32.band(child_flags, ImGuiChildFlags.AlwaysAutoResize) ~= 0 then
        IM_ASSERT(bit32.band(child_flags, bit32.bor(ImGuiChildFlags.ResizeX, ImGuiChildFlags.ResizeY)) == 0, "Cannot use ImGuiChildFlags.ResizeX or ImGuiChildFlags.ResizeY with ImGuiChildFlags.AlwaysAutoResize!")
        IM_ASSERT(bit32.band(child_flags, bit32.bor(ImGuiChildFlags.AutoResizeX, ImGuiChildFlags.AutoResizeY)) ~= 0, "Must use ImGuiChildFlags.AutoResizeX or ImGuiChildFlags.AutoResizeY with ImGuiChildFlags.AlwaysAutoResize!")
    end
    if bit32.band(child_flags, ImGuiChildFlags.AutoResizeX) ~= 0 then
        child_flags = bit32.band(child_flags, bit32.bnot(ImGuiChildFlags.ResizeX))
    end
    if bit32.band(child_flags, ImGuiChildFlags.AutoResizeY) ~= 0 then
        child_flags = bit32.band(child_flags, bit32.bnot(ImGuiChildFlags.ResizeY))
    end

    -- Set window flags
    window_flags = bit32.bor(window_flags, ImGuiWindowFlags.ChildWindow, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoDocking)
    window_flags = bit32.bor(window_flags, bit32.band(parent_window.Flags, ImGuiWindowFlags.NoMove)) -- Inherit the NoMove flag
    if bit32.band(child_flags, bit32.bor(ImGuiChildFlags.AutoResizeX, ImGuiChildFlags.AutoResizeY, ImGuiChildFlags.AlwaysAutoResize)) ~= 0 then
        window_flags = bit32.bor(window_flags, ImGuiWindowFlags.AlwaysAutoResize) -- FIXME: Would be sane to not make single-axis flag set this. (#9355)
    end
    if bit32.band(child_flags, bit32.bor(ImGuiChildFlags.ResizeX, ImGuiChildFlags.ResizeY)) == 0 then
        window_flags = bit32.bor(window_flags, ImGuiWindowFlags.NoResize, ImGuiWindowFlags.NoSavedSettings)
    end

    -- Special framed style
    if bit32.band(child_flags, ImGuiChildFlags.FrameStyle) ~= 0 then
        ImGui.PushStyleColor(ImGuiCol.ChildBg, g.Style.Colors[ImGuiCol.FrameBg])
        ImGui.PushStyleVar(ImGuiStyleVar.ChildRounding, g.Style.FrameRounding)
        ImGui.PushStyleVar(ImGuiStyleVar.ChildBorderSize, g.Style.FrameBorderSize)
        ImGui.PushStyleVar(ImGuiStyleVar.WindowPadding, g.Style.FramePadding)
        child_flags = bit32.bor(child_flags, ImGuiChildFlags.Borders, ImGuiChildFlags.AlwaysUseWindowPadding)
        window_flags = bit32.bor(window_flags, ImGuiWindowFlags.NoMove)
    end

    -- Forward size
    -- Important: Begin() has special processing to switch condition to ImGuiCond.FirstUseEver for a given axis when ImGuiChildFlags.ResizeXXX is set.
    -- (the alternative would to store conditional flags per axis, which is possible but more code)
    local size_avail = ImGui.GetContentRegionAvail()
    local size_default = ImVec2((bit32.band(child_flags, ImGuiChildFlags.AutoResizeX) ~= 0) and 0.0 or size_avail.x, (bit32.band(child_flags, ImGuiChildFlags.AutoResizeY) ~= 0) and 0.0 or size_avail.y)
    local size = ImGui.CalcItemSize(size_arg, size_default.x, size_default.y)

    -- A SetNextWindowSize() call always has priority (#8020)
    -- (since the code in Begin() never supported SizeVal==0.0 aka auto-resize via SetNextWindowSize() call, we don't support it here for now)
    -- FIXME: We only support ImGuiCond.Always in this path. Supporting other paths would requires to obtain window pointer.
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasSize) ~= 0 and bit32.band(g.NextWindowData.SizeCond, ImGuiCond.Always) ~= 0 then
        if g.NextWindowData.SizeVal.x > 0.0 then
            size.x = g.NextWindowData.SizeVal.x
            child_flags = bit32.band(child_flags, bit32.bnot(ImGuiChildFlags.ResizeX))
        end
        if g.NextWindowData.SizeVal.y > 0.0 then
            size.y = g.NextWindowData.SizeVal.y
            child_flags = bit32.band(child_flags, bit32.bnot(ImGuiChildFlags.ResizeY))
        end
    end
    ImGui.SetNextWindowSize(size)
    ImGui.SetNextWindowChildFlags(child_flags, true)

    -- Build up name. If you need to append to a same child from multiple location in the ID stack, use BeginChild(ImGuiID id) with a stable value.
    -- FIXME: 2023/11/14: commented out shorted version. We had an issue with multiple ### in child window path names, which the trailing hash helped workaround.
    -- e.g. "ParentName###ParentIdentifier/ChildName###ChildIdentifier" would get hashed incorrectly by ImHashStr(), trailing _%08X somehow fixes it.
    local temp_window_name
    -- if (name and parent_window.IDStack:back() == parent_window.ID)
    --     temp_window_name = ImFormatString("%s/%s", parent_window.Name, name) -- May omit ID if in root of ID stack
    -- else
    if name then
        temp_window_name = ImFormatString("%s/%s_%08X", parent_window.Name, name, id)
    else
        temp_window_name = ImFormatString("%s/%08X", parent_window.Name, id)
    end

    -- Set style
    local backup_border_size = g.Style.ChildBorderSize
    if bit32.band(child_flags, ImGuiChildFlags.Borders) == 0 then
        g.Style.ChildBorderSize = 0.0
    end

    -- Begin into window
    local _, ret = ImGui.Begin(temp_window_name, nil, window_flags)

    -- Restore style
    g.Style.ChildBorderSize = backup_border_size

    if bit32.band(child_flags, ImGuiChildFlags.FrameStyle) ~= 0 then
        ImGui.PopStyleVar(3)
        ImGui.PopStyleColor()
    end

    local child_window = g.CurrentWindow
    child_window.ChildId = id

    -- Set the cursor to handle case where the user called SetNextWindowPos()+BeginChild() manually.
    -- While this is not really documented/defined, it seems that the expected thing to do.
    if child_window.BeginCount == 1 then
        ImVec2_Copy(parent_window.DC.CursorPos, child_window.Pos)
    end

    -- Process navigation-in immediately so NavInit can run on first frame
    -- Can enter a child if (A) it has navigable items or (B) it can be scrolled.
    local temp_id_for_activation = ImHashStr("##Child", nil, id)
    if g.ActiveId == temp_id_for_activation then
        ImGui.ClearActiveID()
    end
    if g.NavActivateId == id and bit32.band(child_flags, ImGuiChildFlags.NavFlattened) == 0 and (child_window.DC.NavLayersActiveMask ~= 0 or child_window.DC.NavWindowHasScrollY) then
        ImGui.FocusWindow(child_window)
        ImGui.NavInitWindow(child_window, false)
        ImGui.SetActiveID(temp_id_for_activation, child_window) -- Steal ActiveId with another arbitrary id so that key-press won't activate child item
        g.ActiveIdSource = g.NavInputSource
    end

    return ret
end

-- Prior to v1.90 2023/10/16, the BeginChild() function took a 'bool border = false' parameter instead of 'ImGuiChildFlags child_flags = 0'.
-- ImGuiChildFlags.Borders is defined as always == 1 in order to allow old code passing 'true'. Read comments in imgui.h for details!
-- `true` is accepted as ImGuiChildFlags.Borders for legacy code.
--- @param str_id_or_id string|ImGuiID
--- @param size_arg?     ImVec2
--- @param child_flags?  ImGuiChildFlags|bool
--- @param window_flags? ImGuiWindowFlags
--- @return bool # visible (always call EndChild()!)
function ImGui.BeginChild(str_id_or_id, size_arg, child_flags, window_flags)
    if child_flags == true then child_flags = ImGuiChildFlags.Borders elseif not child_flags then child_flags = 0 end
    if type(str_id_or_id) == "number" then
        return ImGui.BeginChildEx(nil, str_id_or_id, size_arg, child_flags, window_flags)
    end
    local id = ImGui.GetCurrentWindow():GetID(str_id_or_id)
    return ImGui.BeginChildEx(str_id_or_id, id, size_arg, child_flags, window_flags)
end

--- @param window ImGuiWindow
--- @param rect   ImRect
function ImGui.SetLastItemDataForChildWindowItem(window, rect)
    local g = GImGui
    ImGui.SetLastItemData(window.ChildId, g.CurrentItemFlags, window.DC.ChildItemStatusFlags or 0, rect)
end

function ImGui.EndChild()
    local g = GImGui
    local child_window = g.CurrentWindow

    local backup_within_end_child_id = g.WithinEndChildID
    IM_ASSERT(bit32.band(child_window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0) -- Mismatched BeginChild()/EndChild() calls

    g.WithinEndChildID = child_window.ID
    local child_size = ImVec2(child_window.Size.x, child_window.Size.y)
    ImGui.End()
    if child_window.BeginCount == 1 then
        local parent_window = g.CurrentWindow
        local bb = ImRect(parent_window.DC.CursorPos, parent_window.DC.CursorPos + child_size)
        ImGui.ItemSize(child_size)
        local nav_flattened = bit32.band(child_window.ChildFlags, ImGuiChildFlags.NavFlattened) ~= 0
        if (child_window.DC.NavLayersActiveMask ~= 0 or child_window.DC.NavWindowHasScrollY) and not nav_flattened then
            ImGui.ItemAdd(bb, child_window.ChildId)
            ImGui.RenderNavCursor(bb, child_window.ChildId)

            -- When browsing a window that has no activable items (scroll only) we keep a highlight on the child (pass g.NavId to trick into always displaying)
            if child_window.DC.NavLayersActiveMask == 0 and child_window == g.NavWindow then
                ImGui.RenderNavCursor(ImRect(bb.Min - ImVec2(2, 2), bb.Max + ImVec2(2, 2)), g.NavId, ImGuiNavRenderCursorFlags.Compact)
            end
        else
            -- Not navigable into
            -- - This is a bit of a fringe use case, mostly useful for undecorated, non-scrolling contents childs, or empty childs.
            -- - We could later decide to not apply this path if ImGuiChildFlags.FrameStyle or ImGuiChildFlags.Borders is set.
            ImGui.ItemAdd(bb, child_window.ChildId, nil, ImGuiItemFlags.NoNav)

            -- But when flattened we directly reach items, adjust active layer mask accordingly
            if nav_flattened then
                parent_window.DC.NavLayersActiveMaskNext = bit32.bor(parent_window.DC.NavLayersActiveMaskNext, child_window.DC.NavLayersActiveMaskNext)
            end
        end
        if g.HoveredWindow == child_window then
            g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HoveredWindow)
        end
        child_window.DC.ChildItemStatusFlags = g.LastItemData.StatusFlags
        -- SetLastItemDataForChildWindowItem(child_window, child_window:Rect()) -- Not needed, effectively done by ItemAdd()
    else
        ImGui.SetLastItemDataForChildWindowItem(child_window, child_window:Rect())
    end

    g.WithinEndChildID = backup_within_end_child_id
    g.LogLinePosY = -FLT_MAX -- To enforce a carriage return
end

--- @param flags   ImGuiChildFlags
--- @param enabled bool
function ImGui.SetNextWindowChildFlags(flags, enabled)
    local g = GImGui
    local nwd = g.NextWindowData
    if bit32.band(nwd.HasFlags, ImGuiNextWindowDataFlags.HasChildFlags) == 0 then
        nwd.ChildFlagsSet = 0; nwd.ChildFlagsClear = 0
    end
    if enabled then
        nwd.ChildFlagsSet = bit32.bor(nwd.ChildFlagsSet, flags)
        nwd.ChildFlagsClear = bit32.band(nwd.ChildFlagsClear, bit32.bnot(flags))
    else
        nwd.ChildFlagsSet = bit32.band(nwd.ChildFlagsSet, bit32.bnot(flags))
        nwd.ChildFlagsClear = bit32.bor(nwd.ChildFlagsClear, flags)
    end
    nwd.HasFlags = bit32.bor(nwd.HasFlags, ImGuiNextWindowDataFlags.HasChildFlags)
end

--- @param flags   ImGuiWindowFlags
--- @param enabled bool
function ImGui.SetNextWindowFlags(flags, enabled)
    local g = GImGui
    local nwd = g.NextWindowData
    if bit32.band(nwd.HasFlags, ImGuiNextWindowDataFlags.HasWindowFlags) == 0 then
        nwd.WindowFlagsSet = 0; nwd.WindowFlagsClear = 0
    end
    if enabled then
        nwd.WindowFlagsSet = bit32.bor(nwd.WindowFlagsSet, flags)
        nwd.WindowFlagsClear = bit32.band(nwd.WindowFlagsClear, bit32.bnot(flags))
    else
        nwd.WindowFlagsSet = bit32.band(nwd.WindowFlagsSet, bit32.bnot(flags))
        nwd.WindowFlagsClear = bit32.bor(nwd.WindowFlagsClear, flags)
    end
    nwd.HasFlags = bit32.bor(nwd.HasFlags, ImGuiNextWindowDataFlags.HasWindowFlags)
end

-- Content size = inner scrollable rectangle, padded with WindowPadding.
-- SetNextWindowContentSize(ImVec2(100,100)) + ImGuiWindowFlags.AlwaysAutoResize will always allow submitting a 100x100 item.
--- @param size ImVec2
function ImGui.SetNextWindowContentSize(size)
    local g = GImGui
    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasContentSize)
    ImVec2_CopyV(g.NextWindowData.ContentSizeVal, ImTrunc(size.x), ImTrunc(size.y))
end

--- @param scroll ImVec2
function ImGui.SetNextWindowScroll(scroll)
    local g = GImGui
    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasScroll)
    ImVec2_Copy(g.NextWindowData.ScrollVal, scroll)
end

--- @param collapsed bool
--- @param cond?     ImGuiCond
function ImGui.SetNextWindowCollapsed(collapsed, cond)
    if cond == nil then cond = 0 end
    local g = GImGui
    IM_ASSERT(cond == 0 or ImIsPowerOfTwo(cond)) -- Make sure the user doesn't attempt to combine multiple condition flags.
    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasCollapsed)
    g.NextWindowData.CollapsedVal = collapsed
    g.NextWindowData.CollapsedCond = (cond ~= 0) and cond or ImGuiCond.Always
end

function ImGui.SetNextWindowFocus()
    local g = GImGui
    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasFocus)
end

--- @param id ImGuiID
function ImGui.SetNextWindowViewport(id)
    local g = GImGui
    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasViewport)
    g.NextWindowData.ViewportId = id
end

--- @param window_class ImGuiWindowClass
function ImGui.SetNextWindowClass(window_class)
    local g = GImGui
    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasWindowClass)
    local wc = ImGuiWindowClass()
    for k, v in pairs(window_class) do wc[k] = v end -- C++ copies the struct
    g.NextWindowData.WindowClass = wc
end

-- This is experimental and meant to be a toy for exploring a future/wider range of features.
--- @param flags ImGuiWindowRefreshFlags
function ImGui.SetNextWindowRefreshPolicy(flags)
    local g = GImGui
    g.NextWindowData.HasFlags = bit32.bor(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasRefreshPolicy)
    g.NextWindowData.RefreshFlagsVal = flags
    g.NextWindowData.CacheKeySet = false
end

-- [Port] Opt-in cached window (built on the refresh policy above). While nothing that could change the window
-- happened, Begin() keeps last frame's draw list and returns visible=false, so `if visible then ... end` skips your code.
-- It refreshes when `key` changes (pass e.g. a version number of the data shown), while the window (or a popup/child
-- of it) is hovered, focused or active and for one frame after, and when it appears, moves, resizes, scrolls,
-- collapses, is docked, or the display size or font atlas texture changes.
-- Anything else that changes the contents (style, fonts, time) must be part of `key`.
function ImGui.SetNextWindowCached(key)
    local g = GImGui
    ImGui.SetNextWindowRefreshPolicy(bit32.bor(ImGuiWindowRefreshFlags.TryToAvoidRefresh, ImGuiWindowRefreshFlags.RefreshOnHover, ImGuiWindowRefreshFlags.RefreshOnFocus))
    g.NextWindowData.CacheKeySet = true
    g.NextWindowData.CacheKeyVal = key
end

function ImGui.GetWindowDpiScale()
    return 1.0 -- Roblox: single viewport, no DPI scaling
end

function ImGui.GetWindowViewport()
    local g = GImGui
    return g.CurrentViewport or ImGui.GetMainViewport()
end

-- Prefer using PushFont(nil, style.FontSizeBase * factor), or use style.FontScaleMain to scale all windows.
--- @param scale float
function ImGui.SetWindowFontScale(scale)
    IM_ASSERT(scale > 0.0)
    local window = ImGui.GetCurrentWindow()
    window.FontWindowScale = scale
    ImGui.UpdateCurrentFontSize(0.0)
end

--- @param window ImGuiWindow
function ImGui.StartMouseMovingWindow(window)
    -- Set ActiveId even if the _NoMove flag is set. Without it, dragging away from a window with _NoMove would activate hover on other windows.
    -- We _also_ call this when clicking in a window empty space when io.ConfigWindowsMoveFromTitleBarOnly is set, but clear g.MovingWindow afterward.
    -- This is because we want ActiveId to be set even when the window is not permitted to move.
    local g = GImGui
    ImGui.FocusWindow(window)
    ImGui.SetActiveID(window.MoveId, window)
    if (g.IO.ConfigNavCursorVisibleAuto) then
        g.NavCursorVisible = false
    end
    g.ActiveIdClickOffset = g.IO.MouseClickedPos[0] - window.RootWindowDockTree.Pos
    g.ActiveIdNoClearOnFocusLoss = true
    ImGui.SetActiveIdUsingAllKeyboardKeys()

    local can_move_window = true
    if bit32.band(window.Flags, ImGuiWindowFlags.NoMove) ~= 0 or bit32.band(window.RootWindowDockTree.Flags, ImGuiWindowFlags.NoMove) ~= 0 then
        can_move_window = false
    end
    local node = window.DockNodeAsHost
    if node and node.VisibleWindow and bit32.band(node.VisibleWindow.Flags, ImGuiWindowFlags.NoMove) ~= 0 then
        can_move_window = false
    end
    if can_move_window then
        g.MovingWindow = window
    end
end

-- Handle mouse moving window
-- Note: moving window with the navigation keys (Square + d-pad / Ctrl+Tab + Arrows) are processed in NavUpdateWindowing()
-- FIXME: We don't have strong guarantee that g.MovingWindow stay synced with g.ActiveId == g.MovingWindow.MoveId.
-- This is currently enforced by the fact that BeginDragDropSource() is setting all g.ActiveIdUsingXXXX flags to inhibit navigation inputs,
-- but if we should more thoroughly test cases where g.ActiveId or g.MovingWindow gets changed and not the other.
function ImGui.UpdateMouseMovingWindowNewFrame()
    local g = GImGui

    if g.MovingWindow then
        -- We actually want to move the root window. g.MovingWindow == window we clicked on (could be a child window).
        -- We track it to preserve Focus and so that generally ActiveIdWindow == MovingWindow and ActiveId == MovingWindow.MoveId for consistency.
        ImGui.KeepAliveID(g.ActiveId)
        IM_ASSERT(g.MovingWindow and g.MovingWindow.RootWindowDockTree)

        local moving_window = g.MovingWindow.RootWindowDockTree

        -- When a window stop being submitted while being dragged, it may will its viewport until next Begin()
        local window_disappeared = (not moving_window.WasActive and not moving_window.Active)
        if g.IO.MouseDown[0] and ImGui.IsMousePosValid(g.IO.MousePos) and not window_disappeared then
            local pos = g.IO.MousePos - g.ActiveIdClickOffset
            if moving_window.Pos.x ~= pos.x or moving_window.Pos.y ~= pos.y then
                ImGui.SetWindowPos(moving_window, pos, ImGuiCond.Always)
                if moving_window.Viewport and moving_window.ViewportOwned then -- Synchronize viewport immediately because some overlays may relies on clipping rectangle before we Begin() into the window.
                    ImVec2_Copy(moving_window.Viewport.Pos, pos)
                    moving_window.Viewport:UpdateWorkRect()
                end
            end
            ImGui.FocusWindow(g.MovingWindow)
        else
            ImGui.StopMouseMovingWindow()
            ImGui.ClearActiveID()
        end
    else
        -- When clicking/dragging from a window that has the _NoMove flag, we still set the ActiveId in order to prevent hovering others.
        if (g.ActiveIdWindow and g.ActiveIdWindow.MoveId == g.ActiveId) then
            ImGui.KeepAliveID(g.ActiveId)

            if not g.IO.MouseDown[0] then
                ImGui.ClearActiveID()
            end
        end
    end
end

function ImGui.GetDrawListSharedData()
    return GImGui.DrawListSharedData
end

-- Supported flags: ImGuiPopupFlags.AnyPopupId, ImGuiPopupFlags.AnyPopupLevel
--- @param id          ImGuiID
--- @param popup_flags ImGuiPopupFlags
function ImGui.IsPopupOpen(id, popup_flags)
    local g = GImGui
    if popup_flags == nil then popup_flags = 0 end
    if type(id) == "string" then
        -- str_id overload: with AnyPopupId the id must be 0, otherwise it is hashed with the current window's ID stack
        id = (bit32.band(popup_flags, ImGuiPopupFlags.AnyPopupId) ~= 0) and 0 or g.CurrentWindow:GetID(id)
    end

    if bit32.band(popup_flags, ImGuiPopupFlags.AnyPopupId) ~= 0 then
        -- Return true if any popup is open at the current BeginPopup() level of the popup stack
        -- This may be used to e.g. test for another popups already opened to handle popups priorities at the same level.
        IM_ASSERT(id == 0)
        if bit32.band(popup_flags, ImGuiPopupFlags.AnyPopupLevel) ~= 0 then
            return g.OpenPopupStack.Size > 0
        else
            return g.OpenPopupStack.Size > g.BeginPopupStack.Size
        end
    else
        if bit32.band(popup_flags, ImGuiPopupFlags.AnyPopupLevel) ~= 0 then
            -- Return true if the popup is open anywhere in the popup stack
            for n = 1, g.OpenPopupStack.Size do
                if g.OpenPopupStack.Data[n].PopupId == id then
                    return true
                end
            end
            return false
        else
            -- Return true if the popup is open at the current BeginPopup() level of the popup stack (this is the most-common query)
            return g.OpenPopupStack.Size > g.BeginPopupStack.Size and g.OpenPopupStack.Data[g.BeginPopupStack.Size + 1].PopupId == id
        end
    end
end

-- Also see FindBlockingModal(nil)
--- @return ImGuiWindow?
function ImGui.GetTopMostPopupModal()
    local g = GImGui
    for n = g.OpenPopupStack.Size, 1, -1 do
        local popup = g.OpenPopupStack.Data[n].Window
        if popup then
            if bit32.band(popup.Flags, ImGuiWindowFlags.Modal) ~= 0 then
                return popup
            end
        end
    end
    return nil
end

-- Initiate focusing and moving window when clicking on empty space or title bar.
-- Initiate focusing window when clicking on a disabled item.
-- Handle left-click and right-click focus.
function ImGui.UpdateMouseMovingWindowEndFrame()
    local g = GImGui

    if g.ActiveId ~= 0 or (g.HoveredId ~= 0 and not g.HoveredIdIsDisabled) then
        return
    end

    -- Unless we just made a window/popup appear
    if g.NavWindow and g.NavWindow.Appearing then
        return
    end

    local hovered_window = g.HoveredWindow

    -- Click on empty space to focus window and start moving
    -- (after we're done with all our widgets, so e.g. clicking on docking tab-bar which have set HoveredId already and not get us here!)
    if ImGui.IsMouseClickedEx(0, ImGuiInputFlags.None, ImGuiKeyOwner_NoOwner) then
        -- Handle the edge case of a popup being closed while clicking in its empty space.
        -- If we try to focus it, FocusWindow() > ClosePopupsOverWindow() will accidentally close any parent popups because they are not linked together any more.
        local hovered_root
        if hovered_window then
            hovered_root = hovered_window.RootWindow
        else
            hovered_root = nil
        end
        local is_closed_popup = hovered_root and (bit32.band(hovered_root.Flags, ImGuiWindowFlags.Popup) ~= 0) and not ImGui.IsPopupOpen(hovered_root.PopupId, ImGuiPopupFlags.AnyPopupLevel)
        local is_queued_focus_request = g.NavMoveSubmitted and (bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.FocusApi) ~= 0)

        if hovered_window ~= nil and not is_closed_popup and not is_queued_focus_request then
            ImGui.StartMouseMovingWindow(hovered_window)

            -- FIXME: In principle we might be able to call StopMouseMovingWindow() below.
            -- Please note how StartMouseMovingWindow() and StopMouseMovingWindow() and not entirely symmetrical, at the later doesn't clear ActiveId.

            -- Cancel moving if clicked outside of title bar
            if bit32.band(hovered_window.BgClickFlags, ImGuiWindowBgClickFlags.Move) == 0 then -- set by io.ConfigWindowsMoveFromTitleBarOnly
                if bit32.band(hovered_root.Flags, ImGuiWindowFlags.NoTitleBar) == 0 then
                    if not hovered_root:TitleBarRect():Contains(g.IO.MouseClickedPos[0]) then
                        g.MovingWindow = nil
                    end
                end
            end

            -- Cancel moving if clicked over an item which was disabled or inhibited by popups
            -- (when g.HoveredIdIsDisabled == true && g.HoveredId == 0 we are inhibited by popups, when g.HoveredIdIsDisabled == true && g.HoveredId != 0 we are over a disabled item)
            if g.HoveredIdIsDisabled then
                g.MovingWindow = nil
                g.ActiveIdDisabledId = g.HoveredId
            end
        elseif hovered_window == nil and g.NavWindow ~= nil then
            -- Clicking on void disable focus
            ImGui.FocusWindow(nil, ImGuiFocusRequestFlags.UnlessBelowModal)
        end
    end

    -- With right mouse button we close popups without changing focus based on where the mouse is aimed
    -- Instead, focus will be restored to the window under the bottom-most closed popup.
    -- (The left mouse button path calls FocusWindow on the hovered window, which will lead NewFrame->ClosePopupsOverWindow to trigger)
    if g.HoveredId == 0 and ImGui.IsMouseClickedEx(1, ImGuiInputFlags.None, ImGuiKeyOwner_NoOwner) then
        -- Find the top-most window between HoveredWindow and the top-most Modal Window.
        -- This is where we can trim the popup stack.
        local modal = ImGui.GetTopMostPopupModal()
        local hovered_window_above_modal = hovered_window and (modal == nil or ImGui.IsWindowAbove(hovered_window, modal))
        ImGui.ClosePopupsOverWindow(hovered_window_above_modal and hovered_window or modal, true)
    end
end

-- This is called during NewFrame()->UpdateViewportsNewFrame() only.
-- Need to keep in sync with SetWindowPos()
--- @param window ImGuiWindow
--- @param delta  ImVec2
function ImGui.TranslateWindow(window, delta)
    ImVec2_Copy(window.Pos, window.Pos + delta)
    window.ClipRect:Translate(delta)
    window.OuterRectClipped:Translate(delta)
    window.InnerRect:Translate(delta)

    ImVec2_Copy(window.DC.CursorPos, window.DC.CursorPos + delta)
    ImVec2_Copy(window.DC.CursorStartPos, window.DC.CursorStartPos + delta)
    ImVec2_Copy(window.DC.CursorMaxPos, window.DC.CursorMaxPos + delta)
    ImVec2_Copy(window.DC.IdealMaxPos, window.DC.IdealMaxPos + delta)
end

--- ImGui::FindWindowByID
function ImGui.FindWindowByID(id)
    local g = GImGui

    if not g then return end

    return g.WindowsById[id]
end

--- @param name string
--- @return ImGuiWindow?
function ImGui.FindWindowByName(name)
    local id = ImHashStr(name)
    return ImGui.FindWindowByID(id)
end

-- Push a new Dear ImGui window to add widgets to.
-- - A default window called "Debug" is automatically stacked at the beginning of every frame so you can use widgets without explicitly calling a Begin/End pair.
-- - Begin/End can be called multiple times during the frame with the same window name to append content.
-- - The window name is used as a unique identifier to preserve window information across frames (and save rudimentary information to the .ini file).
--   You can use the "##" or "###" markers to use the same label with different id, or same id with different label. See documentation at the top of this file.
-- - Return false when window is collapsed, so you can early out in your code. You always need to call ImGui.End() even if false is returned.
-- - Passing a non-nil 'open' displays a Close button on the upper-right corner of the window, the returned 'is_open' value will be false when the button is pressed.
--- @param name     string
--- @param open?    bool
--- @param flags?   ImGuiWindowFlags
--- @return bool is_open       # The updated `open` passed in
--- @return bool no_skip_items # You always need to call `ImGui.End()` even if false is returned
function ImGui.Begin(name, open, flags)
    if flags == nil then flags = 0 end

    local g = GImGui
    local style = g.Style

    IM_ASSERT(name ~= nil and name ~= "")       -- Window name required
    IM_ASSERT(g.WithinFrameScope)               -- Forgot to call ImGui.NewFrame()
    IM_ASSERT(g.FrameCountEnded ~= g.FrameCount) -- Called ImGui.Render() or ImGui.EndFrame() and haven't called ImGui.NewFrame() again yet

    -- Find or create
    local window = ImGui.FindWindowByName(name)
    local window_just_created = (window == nil)
    if window_just_created then
        window = CreateNewWindow(name, flags) --- @cast window ImGuiWindow
    end

    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasWindowFlags) ~= 0 then
        flags = bit32.band(bit32.bor(flags, g.NextWindowData.WindowFlagsSet), bit32.bnot(g.NextWindowData.WindowFlagsClear))
    end

    -- Automatically disable manual moving/resizing when NoInputs is set
    if bit32.band(flags, ImGuiWindowFlags.NoInputs) == ImGuiWindowFlags.NoInputs then
        flags = bit32.bor(flags, ImGuiWindowFlags.NoMove, ImGuiWindowFlags.NoResize)
    end

    local current_frame = g.FrameCount
    local first_begin_of_the_frame = (window.LastFrameActive ~= current_frame)
    window.IsFallbackWindow = (g.CurrentWindowStack.Size == 0 and g.WithinFrameScopeWithImplicitWindow)

    -- Update the Appearing flag (note: the BeginDocked() path may also set this to true later)
    local window_just_activated_by_user = (window.LastFrameActive < (current_frame - 1)) -- Not using !WasActive because the implicit "Debug" window would always toggle off->on
    if bit32.band(flags, ImGuiWindowFlags.Popup) ~= 0 then
        local popup_ref = g.OpenPopupStack.Data[g.BeginPopupStack.Size + 1]
        window_just_activated_by_user = window_just_activated_by_user or (window.PopupId ~= popup_ref.PopupId) -- We recycle popups so treat window as activated if popup id changed
        window_just_activated_by_user = window_just_activated_by_user or (window ~= popup_ref.Window)
    end

    -- Update Flags, LastFrameActive, BeginOrderXXX fields
    local window_was_appearing = window.Appearing
    if first_begin_of_the_frame then
        ImGui.UpdateWindowInFocusOrderList(window, window_just_created, flags)
        window.Appearing = window_just_activated_by_user
        if (window.Appearing) then
            SetWindowConditionAllowFlags(window, ImGuiCond.Appearing, true)
        end
        window.FlagsPreviousFrame = window.Flags
        window.Flags = flags
        window.ChildFlags = (bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasChildFlags) ~= 0) and g.NextWindowData.ChildFlagsSet or 0
        window.LastFrameActive = current_frame
        window.LastTimeActive = g.Time
        window.BeginOrderWithinParent = 0
        window.BeginOrderWithinContext = g.WindowsActiveCount
        g.WindowsActiveCount = g.WindowsActiveCount + 1
    else
        flags = window.Flags
    end

    -- Docking
    -- (NB: during the frame dock nodes are created, it is possible that (window->DockIsActive == false) even though (window->DockNode->Windows.Size > 1)
    IM_ASSERT(window.DockNode == nil or window.DockNodeAsHost == nil) -- Cannot be both
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasDock) ~= 0 then
        ImGui.SetWindowDock(window, g.NextWindowData.DockId, g.NextWindowData.DockCond)
    end
    if first_begin_of_the_frame then
        local has_dock_node = (window.DockId ~= 0 or window.DockNode ~= nil)
        local new_auto_dock_node = not has_dock_node and ImGui.GetWindowAlwaysWantOwnTabBar(window)
        local dock_node_was_visible = window.DockNodeIsVisible
        local dock_tab_was_visible = window.DockTabIsVisible
        window.DockIsActive = false
        window.DockNodeIsVisible = false
        window.DockTabIsVisible = false

        if has_dock_node or new_auto_dock_node then
            open = ImGui.BeginDocked(window, open)
            flags = window.Flags
            if window.DockIsActive then
                IM_ASSERT(window.DockNode ~= nil)
                g.NextWindowData.HasFlags = bit32.band(g.NextWindowData.HasFlags, bit32.bnot(ImGuiNextWindowDataFlags.HasSizeConstraint)) -- Docking currently override constraints
            end

            -- Amend the Appearing flag
            if window.DockTabIsVisible and not dock_tab_was_visible and dock_node_was_visible and not window.Appearing and not window_was_appearing then
                window.Appearing = true
                SetWindowConditionAllowFlags(window, ImGuiCond.Appearing, true)
            end
        end
    end

    -- Parent window is latched only on the first call to Begin() of the frame, so further append-calls can be done from a different window stack
    local parent_window_in_stack
    if window.DockIsActive and window.DockNode.HostWindow then
        parent_window_in_stack = window.DockNode.HostWindow
    elseif g.CurrentWindowStack:empty() then
        parent_window_in_stack = nil
    else
        parent_window_in_stack = g.CurrentWindowStack:back().Window
    end
    local parent_window
    if first_begin_of_the_frame then
        if (bit32.band(flags, bit32.bor(ImGuiWindowFlags.ChildWindow, ImGuiWindowFlags.Popup, ImGuiWindowFlags.Tooltip)) ~= 0) then
            parent_window = parent_window_in_stack
        else
            parent_window = nil
        end
    else
        parent_window = window.ParentWindow
    end

    -- We allow window memory to be compacted so recreate the base stack when needed.
    if window.IDStack.Size == 0 then
        window.IDStack:push_back(window.ID)
    end

    -- Add to stack
    g.CurrentWindow = window
    g.CurrentWindowStack:resize(g.CurrentWindowStack.Size + 1)
    g.CurrentWindowStack.Data[g.CurrentWindowStack.Size] = ImGuiWindowStackData()
    local window_stack_data = g.CurrentWindowStack.Data[g.CurrentWindowStack.Size]
    window_stack_data.Window = window
    ImGuiLastItemData_Copy(window_stack_data.ParentLastItemDataBackup, g.LastItemData)
    window_stack_data.DisabledOverrideReenable = (bit32.band(flags, ImGuiWindowFlags.Tooltip) ~= 0) and (bit32.band(g.CurrentItemFlags, ImGuiItemFlags.Disabled) ~= 0)
    window_stack_data.DisabledOverrideReenableAlphaBackup = 0.0
    window_stack_data.StackSizesInBegin = ImGuiErrorRecoveryState()
    ImGui.ErrorRecoveryStoreState(window_stack_data.StackSizesInBegin)
    g.StackSizesInBeginForCurrentWindow = window_stack_data.StackSizesInBegin
    if bit32.band(flags, ImGuiWindowFlags.ChildMenu) ~= 0 then
        g.BeginMenuDepth = g.BeginMenuDepth + 1
    end

    -- Update .RootWindow and others pointers (before any possible call to FocusWindow)
    if first_begin_of_the_frame then
        ImGui.UpdateWindowParentAndRootLinks(window, flags, parent_window)
        window.ParentWindowInBeginStack = parent_window_in_stack

        -- Focus route
        -- There's little point to expose a flag to set this: because the interesting cases won't be using parent_window_in_stack,
        -- Use for e.g. linking a tool window in a standalone viewport to a document window, regardless of their Begin() stack parenting. (#6798)
        if window.RootWindow ~= window then
            window.ParentWindowForFocusRoute = parent_window_in_stack
        else
            window.ParentWindowForFocusRoute = nil
        end
        if window.ParentWindowForFocusRoute == nil and window.DockNode ~= nil then
            if bit32.band(window.DockNode.MergedFlags, ImGuiDockNodeFlags.DockedWindowsInFocusRoute) ~= 0 then
                window.ParentWindowForFocusRoute = window.DockNode.HostWindow
            end
        end
        -- Override with SetNextWindowClass() field or direct call to SetWindowParentWindowForFocusRoute()
        if window.WindowClass and window.WindowClass.FocusRouteParentWindowId ~= nil and window.WindowClass.FocusRouteParentWindowId ~= 0 then
            window.ParentWindowForFocusRoute = ImGui.FindWindowByID(window.WindowClass.FocusRouteParentWindowId)
        end

        -- Inherit SetWindowFontScale() from parent until we fix this system...
        if parent_window then
            window.FontWindowScaleParents = parent_window.FontWindowScaleParents * parent_window.FontWindowScale
        else
            window.FontWindowScaleParents = 1.0
        end
    end

    -- Add to focus scope stack
    ImGui.PushFocusScope((bit32.band(window.ChildFlags, ImGuiChildFlags.NavFlattened) ~= 0) and g.CurrentFocusScopeId or window.ID)
    window.NavRootFocusScopeId = g.CurrentFocusScopeId

    -- Add to popup stacks: update OpenPopupStack[] data, push to BeginPopupStack[]
    if bit32.band(flags, ImGuiWindowFlags.Popup) ~= 0 then
        local popup_ref = g.OpenPopupStack.Data[g.BeginPopupStack.Size + 1]
        popup_ref.Window = window
        popup_ref.ParentNavLayer = parent_window_in_stack.DC.NavLayerCurrent
        g.BeginPopupStack:push_back(popup_ref)
        window.PopupId = popup_ref.PopupId
    end

    -- Process SetNextWindow***() calls
    -- (FIXME: Consider splitting the HasXXX flags into X/Y components)
    local window_pos_set_by_api = false
    local window_size_x_set_by_api = false
    local window_size_y_set_by_api = false
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasPos) ~= 0 then
        window_pos_set_by_api = (bit32.band(window.SetWindowPosAllowFlags, g.NextWindowData.PosCond) ~= 0)
        if window_pos_set_by_api and ImLengthSqr(g.NextWindowData.PosPivotVal) > 1e-5 then
            -- May be processed on the next frame if this is our first frame and we are measuring size
            -- FIXME: Look into removing the branch so everything can go through this same code path for consistency.
            ImVec2_Copy(window.SetWindowPosVal, g.NextWindowData.PosVal)
            ImVec2_Copy(window.SetWindowPosPivot, g.NextWindowData.PosPivotVal)
            window.SetWindowPosAllowFlags = bit32.band(window.SetWindowPosAllowFlags, bit32.bnot(bit32.bor(ImGuiCond.Once, ImGuiCond.FirstUseEver, ImGuiCond.Appearing)))
        else
            ImGui.SetWindowPos(window, g.NextWindowData.PosVal, g.NextWindowData.PosCond)
        end
    end
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasSize) ~= 0 then
        window_size_x_set_by_api = (bit32.band(window.SetWindowSizeAllowFlags, g.NextWindowData.SizeCond) ~= 0) and (g.NextWindowData.SizeVal.x > 0.0)
        window_size_y_set_by_api = (bit32.band(window.SetWindowSizeAllowFlags, g.NextWindowData.SizeCond) ~= 0) and (g.NextWindowData.SizeVal.y > 0.0)
        if (bit32.band(window.ChildFlags, ImGuiChildFlags.ResizeX) ~= 0 and bit32.band(window.SetWindowSizeAllowFlags, ImGuiCond.FirstUseEver) == 0) then -- Axis-specific conditions for BeginChild()
            g.NextWindowData.SizeVal.x = window.SizeFull.x
        end
        if (bit32.band(window.ChildFlags, ImGuiChildFlags.ResizeY) ~= 0 and bit32.band(window.SetWindowSizeAllowFlags, ImGuiCond.FirstUseEver) == 0) then
            g.NextWindowData.SizeVal.y = window.SizeFull.y
        end
        ImGui.SetWindowSize(window, g.NextWindowData.SizeVal, g.NextWindowData.SizeCond);
    end
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasScroll) ~= 0 then
        if g.NextWindowData.ScrollVal.x >= 0.0 then
            window.ScrollTarget.x = g.NextWindowData.ScrollVal.x
            window.ScrollTargetCenterRatio.x = 0.0
        end
        if g.NextWindowData.ScrollVal.y >= 0.0 then
            window.ScrollTarget.y = g.NextWindowData.ScrollVal.y
            window.ScrollTargetCenterRatio.y = 0.0
        end
    end
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasContentSize) ~= 0 then
        ImVec2_Copy(window.ContentSizeExplicit, g.NextWindowData.ContentSizeVal)
    elseif first_begin_of_the_frame then
        window.ContentSizeExplicit = ImVec2(0.0, 0.0)
    end
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasWindowClass) ~= 0 then
        window.WindowClass = g.NextWindowData.WindowClass
    end
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasCollapsed) ~= 0 then
        ImGui.SetWindowCollapsed(window, g.NextWindowData.CollapsedVal, g.NextWindowData.CollapsedCond)
    end
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasFocus) ~= 0 then
        ImGui.FocusWindow(window)
    end
    if window.Appearing then
        SetWindowConditionAllowFlags(window, ImGuiCond.Appearing, false)
    end

    -- [EXPERIMENTAL] Skip Refresh mode
    ImGui.UpdateWindowSkipRefresh(window)

    -- Nested root windows (typically tooltips) override disabled state
    if window_stack_data.DisabledOverrideReenable and window.RootWindow == window then
        ImGui.BeginDisabledOverrideReenable()
    end

    -- We intentionally set g.CurrentWindow to nil to prevent usage until when the viewport is set, then will call SetCurrentWindow()
    g.CurrentWindow = nil

    -- When reusing window again multiple times a frame, just append content (don't need to setup again)
    if first_begin_of_the_frame and not window.SkipRefresh then
        -- Initialize
        local window_is_child_tooltip = (bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0 and bit32.band(flags, ImGuiWindowFlags.Tooltip) ~= 0) -- FIXME-WIP: Undocumented behavior of Child+Tooltip for pinned tooltip (#1345)
        local window_just_appearing_after_hidden_for_resize = (window.HiddenFramesCannotSkipItems > 0)

        window.Active = true
        window.HasCloseButton = (open ~= nil)
        ImRect_CopyFromV4(window.ClipRect, ImVec4(-FLT_MAX, -FLT_MAX, FLT_MAX, FLT_MAX))

        window.IDStack:resize(1)

        window.DrawList:_ResetForNewFrame()
        window.DC.CurrentTableIdx = -1
        if bit32.band(flags, ImGuiWindowFlags.DockNodeHost) ~= 0 then
            window.DrawList:ChannelsSplit(2)
            window.DrawList:ChannelsSetCurrent(1) -- DOCKING_HOST_DRAW_CHANNEL_FG: Render decorations on channel 1 as we will render the backgrounds manually later
        end

        -- Restore buffer capacity when woken from a compacted state, to avoid
        if window.MemoryCompacted then
            ImGui.GcAwakeTransientWindowBuffers(window)
        end

        -- UPDATE CONTENTS SIZE, UPDATE HIDDEN STATUS

        -- Update contents size from last frame for auto-fitting (or use explicit size)
        CalcWindowContentSizes(window, window.ContentSize, window.ContentSizeIdeal)

        -- FIXME: These flags are decremented before they are used. This means that in order to have these fields produce their intended behaviors
        -- for one frame we must set them to at least 2, which is counter-intuitive. HiddenFramesCannotSkipItems is a more complicated case because
        -- it has a single usage before this code block and may be set below before it is finally checked.
        if window.HiddenFramesCanSkipItems > 0 then
            window.HiddenFramesCanSkipItems = window.HiddenFramesCanSkipItems - 1
        end
        if window.HiddenFramesCannotSkipItems > 0 then
            window.HiddenFramesCannotSkipItems = window.HiddenFramesCannotSkipItems - 1
        end
        if window.HiddenFramesForRenderOnly > 0 then
            window.HiddenFramesForRenderOnly = window.HiddenFramesForRenderOnly - 1
        end

        -- Hide new windows for one frame until they calculate their size
        if window_just_created and (not window_size_x_set_by_api or not window_size_y_set_by_api) then
            window.HiddenFramesCannotSkipItems = 1
        end

        -- Hide popup/tooltip window when re-opening while we measure size (because we recycle the windows)
        -- We reset Size/ContentSize for reappearing popups/tooltips early in this function, so further code won't be tempted to use the old size.
        if window_just_activated_by_user and bit32.band(flags, bit32.bor(ImGuiWindowFlags.Popup, ImGuiWindowFlags.Tooltip)) ~= 0 then
            window.HiddenFramesCannotSkipItems = 1
            if bit32.band(flags, ImGuiWindowFlags.AlwaysAutoResize) ~= 0 then
                if not window_size_x_set_by_api then
                    window.SizeFull.x = 0.0
                    window.Size.x = 0.0
                end
                if not window_size_y_set_by_api then
                    window.SizeFull.y = 0.0
                    window.Size.y = 0.0
                end
                ImVec2_Copy(window.ContentSize, ImVec2(0.0, 0.0))
                ImVec2_Copy(window.ContentSizeIdeal, ImVec2(0.0, 0.0))
            end
        end

        -- SELECT VIEWPORT
        -- We need to do this before using any style/font sizes, as viewport with a different DPI may affect font sizes.

        ImGui.WindowSelectViewport(window)
        ImGui.SetCurrentViewport(window, window.Viewport)
        SetCurrentWindow(window)
        flags = window.Flags

        -- LOCK BORDER SIZE AND PADDING FOR THE FRAME (so that altering them doesn't cause inconsistencies)
        -- We read Style data after the call to UpdateSelectWindowViewport() which might be swapping the style.

        if not window.DockIsActive and bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0 then
            window.WindowBorderSize = style.ChildBorderSize
        else
            window.WindowBorderSize = (bit32.band(flags, bit32.bor(ImGuiWindowFlags.Popup, ImGuiWindowFlags.Tooltip)) ~= 0 and bit32.band(flags, ImGuiWindowFlags.Modal) == 0) and style.PopupBorderSize or style.WindowBorderSize
        end
        window.WindowPadding = style.WindowPadding
        if not window.DockIsActive and (bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0) and (bit32.band(flags, ImGuiWindowFlags.Popup) == 0) and (bit32.band(window.ChildFlags, ImGuiChildFlags.AlwaysUseWindowPadding) == 0) and window.WindowBorderSize == 0.0 then
            if bit32.band(flags, ImGuiWindowFlags.MenuBar) ~= 0 then
                window.WindowPadding = ImVec2(0.0, style.WindowPadding.y)
            else
                window.WindowPadding = ImVec2(0.0, 0.0)
            end
        end

        -- Lock menu offset so size calculation can use it as menu-bar windows need a minimum size.
        window.DC.MenuBarOffset.x = ImMax(ImMax(window.WindowPadding.x, style.ItemSpacing.x), g.NextWindowData.MenuBarOffsetMinVal.x)
        window.DC.MenuBarOffset.y = g.NextWindowData.MenuBarOffsetMinVal.y

        if bit32.band(flags, ImGuiWindowFlags.NoTitleBar) ~= 0 then
            window.TitleBarHeight = 0.0
        else
            window.TitleBarHeight = g.FontSize + g.Style.FramePadding.y * 2.0
        end

        if bit32.band(flags, ImGuiWindowFlags.MenuBar) ~= 0 then
            window.MenuBarHeight = window.DC.MenuBarOffset.y + g.FontSize + g.Style.FramePadding.y * 2.0
        else
            window.MenuBarHeight = 0.0
        end

        window.TitleBarHeight = (bit32.band(flags, ImGuiWindowFlags.NoTitleBar) ~= 0) and 0 or g.FontSize + g.Style.FramePadding.y * 2

        window.FontRefSize = g.FontSize -- Lock this to discourage calling window:CalcFontSize() outside of current window.

        -- Depending on condition we use previous or current window size to compare against contents size to decide if a scrollbar should be visible.
        -- Those flags will be altered further down in the function depending on more conditions.
        local use_current_size_for_scrollbar_x = window_just_created
        local use_current_size_for_scrollbar_y = window_just_created
        if window_size_x_set_by_api and window.ContentSizeExplicit.x ~= 0.0 then
            use_current_size_for_scrollbar_x = true
        end
        if window_size_y_set_by_api and window.ContentSizeExplicit.y ~= 0.0 then -- #7252
            use_current_size_for_scrollbar_y = true
        end

        -- Collapse window by double-clicking on title bar
        -- At this point we don't have a clipping rectangle setup yet, so we can use the title bar area for hit detection and drawing
        if bit32.band(flags, ImGuiWindowFlags.NoTitleBar) == 0 and bit32.band(flags, ImGuiWindowFlags.NoCollapse) == 0 and not window.DockIsActive then
            -- We don't use a regular button+id to test for double-click on title bar (mostly due to legacy reason, could be fixed),
            -- so verify that we don't have items over the title bar.
            local title_bar_rect = window:TitleBarRect()
            if g.HoveredWindow == window and g.HoveredId == 0 and g.HoveredIdPreviousFrame == 0 and g.ActiveId == 0 and ImGui.IsMouseHoveringRect(title_bar_rect.Min, title_bar_rect.Max) then
                if g.IO.MouseClickedCount[0] == 2 and ImGui.GetKeyOwner(ImGuiKey.MouseLeft) == ImGuiKeyOwner_NoOwner then
                    window.WantCollapseToggle = true
                    ImGui.SetKeyOwner(ImGuiKey.MouseLeft, window.MoveId) -- Claim input the same way ButtonBehavior() does. Prevent a same-frame move from triggering other items. (#9439)
                end
            end
            if window.WantCollapseToggle then
                window.Collapsed = not window.Collapsed
                if not window.Collapsed then
                    use_current_size_for_scrollbar_y = true
                end
                ImGui.MarkIniSettingsDirty(window)
            end
        else
            window.Collapsed = false
        end
        window.WantCollapseToggle = false

        -- SIZE

        -- Outer Decoration Sizes
        -- (we need to clear ScrollbarSize immediately as CalcWindowAutoFitSize() needs it and can be called from other locations).
        local scrollbar_sizes_from_last_frame = ImVec2()
        ImVec2_Copy(scrollbar_sizes_from_last_frame, window.ScrollbarSizes)

        window.DecoOuterSizeX1 = 0.0
        window.DecoOuterSizeX2 = 0.0
        window.DecoOuterSizeY1 = window.TitleBarHeight + window.MenuBarHeight
        window.DecoOuterSizeY2 = 0.0
        window.ScrollbarSizes = ImVec2(0.0, 0.0)

        -- Calculate auto-fit size, handle automatic resize
        -- - Using SetNextWindowSize() overrides ImGuiWindowFlags.AlwaysAutoResize, so it can be used on tooltips/popups, etc.
        -- - We still process initial auto-fit on collapsed windows to get a window width, but otherwise don't honor ImGuiWindowFlags.AlwaysAutoResize when collapsed.
        -- - Auto-fit may only grow window during the first few frames.
        do
            local size_auto_fit_x_always = not window_size_x_set_by_api and (bit32.band(flags, ImGuiWindowFlags.AlwaysAutoResize) ~= 0) and not window.Collapsed
            local size_auto_fit_y_always = not window_size_y_set_by_api and (bit32.band(flags, ImGuiWindowFlags.AlwaysAutoResize) ~= 0) and not window.Collapsed
            local size_auto_fit_x_current = not window_size_x_set_by_api and (window.AutoFitFramesX > 0)
            local size_auto_fit_y_current = not window_size_y_set_by_api and (window.AutoFitFramesY > 0)

            local size_auto_fit_mask = 0
            if size_auto_fit_x_always or size_auto_fit_x_current then
                size_auto_fit_mask = bit32.bor(size_auto_fit_mask, bit32.lshift(1, ImGuiAxis.X - 1))
            end
            if size_auto_fit_y_always or size_auto_fit_y_current then
                size_auto_fit_mask = bit32.bor(size_auto_fit_mask, bit32.lshift(1, ImGuiAxis.Y - 1))
            end

            local size_auto_fit = CalcWindowAutoFitSize(window, window.ContentSizeIdeal, size_auto_fit_mask)
            local old_size = ImVec2(window.SizeFull.x, window.SizeFull.y)

            if size_auto_fit_x_always or size_auto_fit_x_current then
                if size_auto_fit_x_always then
                    window.SizeFull.x = size_auto_fit.x
                else
                    if window.AutoFitOnlyGrows then
                        window.SizeFull.x = ImMax(window.SizeFull.x, size_auto_fit.x)
                    else
                        window.SizeFull.x = size_auto_fit.x
                    end
                end
                use_current_size_for_scrollbar_x = true
            end
            if size_auto_fit_y_always or size_auto_fit_y_current then
                if size_auto_fit_y_always then
                    window.SizeFull.y = size_auto_fit.y
                else
                    if window.AutoFitOnlyGrows then
                        window.SizeFull.y = ImMax(window.SizeFull.y, size_auto_fit.y)
                    else
                        window.SizeFull.y = size_auto_fit.y
                    end
                end
                use_current_size_for_scrollbar_y = true
            end

            if old_size.x ~= window.SizeFull.x or old_size.y ~= window.SizeFull.y then
                ImGui.MarkIniSettingsDirty(window)
            end
        end

        -- Apply minimum/maximum window size constraints and final size
        ImVec2_Copy(window.SizeFull, CalcWindowSizeAfterConstraint(window, window.SizeFull))
        ImVec2_Copy(window.Size, (window.Collapsed and bit32.band(flags, ImGuiWindowFlags.ChildWindow) == 0) and window:TitleBarRect():GetSize() or window.SizeFull)

        -- POSITION

        -- Popup latch its initial position, will position itself when it appears next frame
        if window_just_activated_by_user then
            window.AutoPosLastDirection = ImGuiDir.None
            if bit32.band(flags, ImGuiWindowFlags.Popup) ~= 0 and bit32.band(flags, ImGuiWindowFlags.Modal) == 0 and not window_pos_set_by_api then -- FIXME: BeginPopup() could use SetNextWindowPos()
                ImVec2_Copy(window.Pos, g.BeginPopupStack:back().OpenPopupPos)
            end
        end

        -- Position child window
        if bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0 then
            IM_ASSERT(parent_window and parent_window.Active)
            window.BeginOrderWithinParent = parent_window.DC.ChildWindows.Size
            parent_window.DC.ChildWindows:push_back(window)
            if (bit32.band(flags, ImGuiWindowFlags.Popup) == 0) and not window_pos_set_by_api and not window_is_child_tooltip then
                ImVec2_Copy(window.Pos, parent_window.DC.CursorPos)
            end
        end

        local window_pos_with_pivot = (window.SetWindowPosVal.x ~= FLT_MAX and window.HiddenFramesCannotSkipItems == 0)
        if window_pos_with_pivot then
            ImGui.SetWindowPos(window, window.SetWindowPosVal - window.Size * window.SetWindowPosPivot, 0) -- Position given a pivot (e.g. for centering)
        elseif (bit32.band(flags, ImGuiWindowFlags.ChildMenu) ~= 0) then
            ImVec2_Copy(window.Pos, ImGui.FindBestWindowPosForPopup(window))
        elseif (bit32.band(flags, ImGuiWindowFlags.Popup) ~= 0) and not window_pos_set_by_api and window_just_appearing_after_hidden_for_resize then
            ImVec2_Copy(window.Pos, ImGui.FindBestWindowPosForPopup(window))
        elseif (bit32.band(flags, ImGuiWindowFlags.Tooltip) ~= 0) and not window_pos_set_by_api and not window_is_child_tooltip then
            ImVec2_Copy(window.Pos, ImGui.FindBestWindowPosForPopup(window))
        end

        -- Late create viewport if we don't fit within our current host viewport.
        if window.ViewportAllowPlatformMonitorExtend >= 0 and not window.ViewportOwned and bit32.band(window.Viewport.Flags, ImGuiViewportFlags.IsMinimized) == 0 then
            if not window.Viewport:GetMainRect():Contains(window:Rect()) then
                -- This is based on the assumption that the DPI will be known ahead (same as the DPI of the selection done in UpdateSelectWindowViewport)
                -- local old_viewport = window.Viewport
                window.Viewport = ImGui.AddUpdateViewport(window, window.ID, window.Pos, window.Size, ImGuiViewportFlags.NoFocusOnAppearing)

                -- FIXME-DPI
                -- IM_ASSERT(old_viewport.DpiScale == window.Viewport.DpiScale) -- FIXME-DPI: Something went wrong
                ImGui.SetCurrentViewport(window, window.Viewport)
                SetCurrentWindow(window)
            end
        end

        if window.ViewportOwned then
            ImGui.WindowSyncOwnedViewport(window, parent_window_in_stack)
        end

        -- Calculate the range of allowed position for that window (to be movable and visible past safe area padding)
        -- When clamping to stay visible, we will enforce that window.Pos stays inside of visibility_rect.
        local viewport_rect = window.Viewport:GetMainRect()
        local viewport_work_rect = window.Viewport:GetWorkRect()
        local visibility_padding = ImMax(style.DisplayWindowPadding, style.DisplaySafeAreaPadding)
        local visibility_rect = ImRect(viewport_work_rect.Min + visibility_padding, viewport_work_rect.Max - visibility_padding)

        -- Clamp position/size so window stays visible within its viewport or monitor
        -- Ignore zero-sized display explicitly to avoid losing positions if a window manager reports zero-sized window when initializing or minimizing.
        -- FIXME: Similar to code in GetWindowAllowedExtentRect()
        if not window_pos_set_by_api and bit32.band(flags, ImGuiWindowFlags.ChildWindow) == 0 then
            if not window.ViewportOwned and viewport_rect:GetWidth() > 0 and viewport_rect:GetHeight() > 0.0 then
                local size_for_clamping_y = window.Size.y
                if bit32.band(window.BgClickFlags, ImGuiWindowBgClickFlags.Move) == 0 and bit32.band(window.Flags, ImGuiWindowFlags.NoTitleBar) == 0 then
                    size_for_clamping_y = window.TitleBarHeight
                end
                window.Pos.x = ImClamp(window.Pos.x, visibility_rect.Min.x - window.Size.x, visibility_rect.Max.x)
                window.Pos.y = ImClamp(window.Pos.y, visibility_rect.Min.y - size_for_clamping_y, visibility_rect.Max.y)
            end
        end
        window.Pos.x = ImTrunc(window.Pos.x) window.Pos.y = ImTrunc(window.Pos.y)

        -- Apply window focus (new and reactivated windows are moved to front)
        local want_focus = false
        if (window_just_activated_by_user and bit32.band(flags, ImGuiWindowFlags.NoFocusOnAppearing) == 0) then
            if bit32.band(flags, ImGuiWindowFlags.Popup) ~= 0 then
                want_focus = true
            elseif (window.DockIsActive or bit32.band(flags, ImGuiWindowFlags.ChildWindow) == 0) and bit32.band(flags, ImGuiWindowFlags.Tooltip) == 0 then
                want_focus = true
            end
        end

        -- Lock window rounding for the frame (so that altering them doesn't cause inconsistencies)
        -- Large values tend to lead to variety of artifacts and are not recommended.
        if bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0 and not window.DockIsActive then
            window.WindowRounding = style.ChildRounding
        elseif window.RootWindowDockTree.ViewportOwned then
            window.WindowRounding = 0.0
        else
            if (bit32.band(flags, ImGuiWindowFlags.Popup) ~= 0 and bit32.band(flags, ImGuiWindowFlags.Modal) == 0) then
                window.WindowRounding = style.PopupRounding
            else
                window.WindowRounding = style.WindowRounding
            end
        end

        -- Decide if we are going to handle borders and resize grips
        -- 'window.SkipItems' is not updated yet so for child windows we rely on ParentWindow to avoid submitting decorations. (#8815)
        -- Whenever we add support for full decorated child windows we will likely make this logic more general.
        local handle_borders_and_resize_grips = (window.DockNodeAsHost ~= nil or not window.DockIsActive)
        if bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0 and window.ParentWindow.SkipItems then
            handle_borders_and_resize_grips = false
        end

        -- Handle manual resize: Resize Grips, Borders, Gamepad
        -- Child windows can only be resized when they have the flags set. The resize grip allows resizing in both directions, so it should appear only if both flags are set.
        local border_hovered, border_held = -1, -1
        local resize_grip_col = {0, 0, 0, 0}

        local resize_grip_count
        if (bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0) and (bit32.band(flags, ImGuiWindowFlags.Popup) == 0) then
            if (bit32.band(window.ChildFlags, ImGuiChildFlags.ResizeX) ~= 0) and (bit32.band(window.ChildFlags, ImGuiChildFlags.ResizeY) ~= 0) then
                resize_grip_count = 1
            else
                resize_grip_count = 0
            end
        else
            resize_grip_count = g.IO.ConfigWindowsResizeFromEdges and 2 or 1 -- Allow resize from lower-left if we have the mouse cursor feedback for it.
        end

        local resize_grip_draw_size = ImTrunc(ImMax(g.FontSize * 1.10, g.Style.WindowRounding + 1.0 + g.FontSize * 0.2))
        if handle_borders_and_resize_grips and not window.Collapsed then
            local auto_fit_mask
            auto_fit_mask, border_hovered, border_held = UpdateWindowManualResize(window, resize_grip_count, resize_grip_col, visibility_rect)
            if auto_fit_mask ~= 0 then
                if bit32.band(auto_fit_mask, bit32.lshift(1, ImGuiAxis.X - 1)) ~= 0 then
                    use_current_size_for_scrollbar_x = true
                end
                if bit32.band(auto_fit_mask, bit32.lshift(1, ImGuiAxis.Y - 1)) ~= 0 then
                    use_current_size_for_scrollbar_y = true
                end
            end
        end
        window.ResizeBorderHovered = border_hovered
        window.ResizeBorderHeld = border_held

        -- Synchronize window --> viewport again and one last time (clamping and manual resize may have affected either)
        if window.ViewportOwned then
            if not window.Viewport.PlatformRequestMove then
                ImVec2_Copy(window.Viewport.Pos, window.Pos)
            end
            if not window.Viewport.PlatformRequestResize then
                ImVec2_Copy(window.Viewport.Size, window.Size)
            end
            window.Viewport:UpdateWorkRect()
            viewport_rect = window.Viewport:GetMainRect()
        end

        -- Save last known viewport position within the window itself (so it can be saved in .ini file and restored)
        ImVec2_Copy(window.ViewportPos, window.Viewport.Pos)

        -- SCROLLBAR VISIBILITY

        -- Update scrollbar visibility (based on the Size that was effective during last frame or the auto-resized Size).
        if not window.Collapsed then
            -- When reading the current size we need to read it after size constraints have been applied.
            -- Intentionally use previous frame values for InnerRect and ScrollbarSizes.
            -- And when we use window.DecorationUp here it doesn't have ScrollbarSizes.y applied yet.
            local avail_size_from_current_frame = ImVec2(window.SizeFull.x, window.SizeFull.y - (window.DecoOuterSizeY1 + window.DecoOuterSizeY2))
            local avail_size_from_last_frame = window.InnerRect:GetSize() + scrollbar_sizes_from_last_frame
            local needed_size_from_last_frame = window_just_created and ImVec2(0, 0) or window.ContentSize + window.WindowPadding * 2.0

            local size_for_scrollbars_x = use_current_size_for_scrollbar_x and avail_size_from_current_frame.x or avail_size_from_last_frame.x
            local size_for_scrollbars_y = use_current_size_for_scrollbar_y and avail_size_from_current_frame.y or avail_size_from_last_frame.y

            local scrollbar_x_prev = window.ScrollbarX
            -- local scrollbar_y_from_last_frame = window.ScrollbarY -- FIXME: May want to use that in the ScrollbarX expression? How many pros vs cons?

            window.ScrollbarY = (bit32.band(flags, ImGuiWindowFlags.AlwaysVerticalScrollbar) ~= 0) or ((needed_size_from_last_frame.y > size_for_scrollbars_y) and not (bit32.band(flags, ImGuiWindowFlags.NoScrollbar) ~= 0))
            window.ScrollbarX = (bit32.band(flags, ImGuiWindowFlags.AlwaysHorizontalScrollbar) ~= 0) or ((needed_size_from_last_frame.x > size_for_scrollbars_x - (window.ScrollbarY and style.ScrollbarSize or 0.0)) and not (bit32.band(flags, ImGuiWindowFlags.NoScrollbar) ~= 0) and (bit32.band(flags, ImGuiWindowFlags.HorizontalScrollbar) ~= 0))

            -- Track when ScrollbarX visibility keeps toggling, which is a sign of a feedback loop, and stabilize by enforcing visibility (#3285, #8488)
            -- (Feedback loops of this sort can manifest in various situations, but combining horizontal + vertical scrollbar + using a clipper with varying width items is one frequent cause.
            --  The better solution is to, either (1) enforce visibility by using ImGuiWindowFlags.AlwaysHorizontalScrollbar or (2) declare stable contents width with SetNextWindowContentSize(), if you can compute it)
            window.ScrollbarXStabilizeToggledHistory = bit32.lshift(window.ScrollbarXStabilizeToggledHistory, 1)
            if scrollbar_x_prev ~= window.ScrollbarX then
                window.ScrollbarXStabilizeToggledHistory = bit32.bor(window.ScrollbarXStabilizeToggledHistory, 0x01)
            end

            local scrollbar_x_stabilize = (window.ScrollbarXStabilizeToggledHistory ~= 0) and ImCountSetBits(window.ScrollbarXStabilizeToggledHistory) >= 4 -- 4 == half of bits in our U8 history.
            if scrollbar_x_stabilize then
                window.ScrollbarX = true
            end

            -- if scrollbar_x_stabilize and not window.ScrollbarXStabilizeEnabled then
            --     IMGUI_DEBUG_LOG("[scroll] Stabilize ScrollbarX for Window '%s'\n", window.Name)
            -- end
            window.ScrollbarXStabilizeEnabled = scrollbar_x_stabilize

            if window.ScrollbarX and not window.ScrollbarY then
                window.ScrollbarY = (needed_size_from_last_frame.y > size_for_scrollbars_y - style.ScrollbarSize) and not (bit32.band(flags, ImGuiWindowFlags.NoScrollbar) ~= 0)
            end

            window.ScrollbarSizes = ImVec2(window.ScrollbarY and style.ScrollbarSize or 0.0, window.ScrollbarX and style.ScrollbarSize or 0.0)

            -- Amend the partially filled window.DecorationXXX values.
            window.DecoOuterSizeX2 = window.DecoOuterSizeX2 + window.ScrollbarSizes.x
            window.DecoOuterSizeY2 = window.DecoOuterSizeY2 + window.ScrollbarSizes.y
        end

        -- UPDATE RECTANGLES (1- THOSE NOT AFFECTED BY SCROLLING)
        -- Update various regions. Variables they depend on should be set above in this function.
        -- We set this up after processing the resize grip so that our rectangles doesn't lag by a frame.

        -- Outer rectangle
        -- Not affected by window border size. Used by:
        -- - FindHoveredWindow() (w/ extra padding when border resize is enabled)
        -- - Begin() initial clipping rect for drawing window background and borders.
        -- - Begin() clipping whole child
        local host_rect
        if (bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0 and bit32.band(flags, ImGuiWindowFlags.Popup) == 0 and not window_is_child_tooltip) then
            host_rect = parent_window.ClipRect
        else
            host_rect = viewport_rect
        end
        local outer_rect = window:Rect()
        local title_bar_rect = window:TitleBarRect()
        ImRect_Copy(window.OuterRectClipped, outer_rect)
        if window.DockIsActive then
            window.OuterRectClipped.Min.y = window.OuterRectClipped.Min.y + window.TitleBarHeight
        end
        window.OuterRectClipped:ClipWith(host_rect)

        -- Inner rectangle
        -- Not affected by window border size. Used by:
        -- - InnerClipRect
        -- - ScrollToRectEx()
        -- - NavUpdatePageUpPageDown()
        -- - Scrollbar()
        window.InnerRect.Min.x = window.Pos.x + window.DecoOuterSizeX1
        window.InnerRect.Min.y = window.Pos.y + window.DecoOuterSizeY1
        window.InnerRect.Max.x = window.Pos.x + window.Size.x - window.DecoOuterSizeX2
        window.InnerRect.Max.y = window.Pos.y + window.Size.y - window.DecoOuterSizeY2

        -- Inner clipping rectangle.
        -- - Extend a outside of normal work region up to borders.
        -- - This is to allow e.g. Selectable or CollapsingHeader or some separators to cover that space.
        -- - It also makes clipped items be more noticeable.
        -- - And is consistent on both axis (prior to 2024/05/03 ClipRect used WindowPadding.x * 0.5 on left and right edge), see #3312
        -- - Force round operator last to ensure that e.g. (int)(max.x-min.x) in user's render code produce correct result.
        -- Note that if our window is collapsed we will end up with an inverted (~null) clipping rectangle which is the correct behavior.
        -- Affected by window/frame border size. Used by:
        -- - Begin() initial clip rect
        local top_border_size = ((bit32.band(flags, ImGuiWindowFlags.MenuBar) ~= 0 or bit32.band(flags, ImGuiWindowFlags.NoTitleBar) == 0) and style.FrameBorderSize or window.WindowBorderSize)

        -- Try to match the fact that our border is drawn centered over the window rectangle, rather than inner.
        -- This is why we do a *0.5 here. We don't currently even technically support large values for WindowBorderSize,
        -- see e.g #7887 #7888, but may do after we move the window border to become an inner border (and then we can remove the 0.5 here).
        window.InnerClipRect.Min.x = ImFloor(0.5 + window.InnerRect.Min.x + window.WindowBorderSize * 0.5)
        window.InnerClipRect.Min.y = ImFloor(0.5 + window.InnerRect.Min.y + top_border_size * 0.5)
        window.InnerClipRect.Max.x = ImFloor(window.InnerRect.Max.x - window.WindowBorderSize * 0.5)
        window.InnerClipRect.Max.y = ImFloor(window.InnerRect.Max.y - window.WindowBorderSize * 0.5)
        window.InnerClipRect:ClipWithFull(host_rect)

        -- SCROLLING

        -- Lock down maximum scrolling
        -- The value of ScrollMax are ahead from ScrollbarX/ScrollbarY which is intentionally using InnerRect from previous rect in order to accommodate
        -- for right/bottom aligned items without creating a scrollbar.
        window.ScrollMax.x = ImMax(0.0, window.ContentSize.x + window.WindowPadding.x * 2.0 - window.InnerRect:GetWidth())
        window.ScrollMax.y = ImMax(0.0, window.ContentSize.y + window.WindowPadding.y * 2.0 - window.InnerRect:GetHeight())

        -- Apply scrolling
        ImVec2_Copy(window.Scroll, CalcNextScrollFromScrollTargetAndClamp(window))
        ImVec2_CopyV(window.ScrollTarget, FLT_MAX, FLT_MAX)
        window.DecoInnerSizeX1 = 0.0; window.DecoInnerSizeY1 = 0.0

        -- DRAWING

        -- Setup draw list and outer clipping rectangle
        IM_ASSERT(window.DrawList.CmdBuffer.Size == 1 and window.DrawList.CmdBuffer.Data[1].ElemCount == 0)
        window.DrawList:PushTexture(g.Font.OwnerAtlas.TexRef)
        ImGui.PushClipRect(host_rect.Min, host_rect.Max, false)

        -- Child windows can render their decoration (bg color, border, scrollbars, etc.) within their parent to save a draw call (since 1.71)
        -- When using overlapping child windows, this will break the assumption that child z-order is mapped to submission order.
        -- FIXME: User code may rely on explicit sorting of overlapping child window and would need to disable this somehow. Please get in contact if you are affected (github #4493)
        local is_undocked_or_docked_visible = not window.DockIsActive or window.DockTabIsVisible
        if is_undocked_or_docked_visible then
            local render_decorations_in_parent = false
            if (bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0) and (bit32.band(flags, ImGuiWindowFlags.Popup) == 0) and not window_is_child_tooltip then
                -- - We test overlap with the previous child window only (testing all would end up being O(log N) not a good investment here)
                -- - We disable this when the parent window has zero vertices, which is a common pattern leading to laying out multiple overlapping childs
                local previous_child
                if parent_window.DC.ChildWindows.Size >= 2 then
                    previous_child = parent_window.DC.ChildWindows.Data[parent_window.DC.ChildWindows.Size - 1]
                else
                    previous_child = nil
                end
                local previous_child_overlapping
                if previous_child ~= nil then
                    previous_child_overlapping = previous_child:Rect():Overlaps(window:Rect())
                else
                    previous_child_overlapping = false
                end
                local parent_is_empty = (parent_window.DrawList.VtxBuffer.Size == 0)
                if (window.DrawList.CmdBuffer:back().ElemCount == 0 and not parent_is_empty and not previous_child_overlapping) then
                    render_decorations_in_parent = true
                end
            end

            if render_decorations_in_parent then
                window.DrawList = parent_window.DrawList
            end

            -- Handle title bar, scrollbar, resize grips and resize borders
            local window_to_highlight = g.NavWindowingTarget or g.NavWindow
            local title_bar_is_highlight = want_focus or (window_to_highlight ~= nil and (window.RootWindowForTitleBarHighlight == window_to_highlight.RootWindowForTitleBarHighlight or (window.DockNode ~= nil and window.DockNode == window_to_highlight.DockNode)))

            RenderWindowDecorations(window, title_bar_rect, title_bar_is_highlight, handle_borders_and_resize_grips, resize_grip_col, resize_grip_draw_size)

            if render_decorations_in_parent then
                window.DrawList = window.DrawListInst
            end
        end

        -- UPDATE RECTANGLES (2- THOSE AFFECTED BY SCROLLING)

        -- Work rectangle.
        -- Affected by window padding and border size. Used by:
        -- - Columns() for right-most edge
        -- - TreeNode(), CollapsingHeader() for right-most edge
        -- - BeginTabBar() for right-most edge
        local allow_scrollbar_x = (bit32.band(flags, ImGuiWindowFlags.NoScrollbar) == 0) and (bit32.band(flags, ImGuiWindowFlags.HorizontalScrollbar) ~= 0)
        local allow_scrollbar_y = (bit32.band(flags, ImGuiWindowFlags.NoScrollbar) == 0)

        local work_rect_size_x
        if window.ContentSizeExplicit.x ~= 0.0 then
            work_rect_size_x = window.ContentSizeExplicit.x
        else
            local content_size_x = allow_scrollbar_x and (window.ContentSize and window.ContentSize.x or 0.0) or 0.0
            local window_size_x = window.Size.x - window.WindowPadding.x * 2.0 - (window.DecoOuterSizeX1 + window.DecoOuterSizeX2)
            work_rect_size_x = ImMax(content_size_x, window_size_x)
        end

        local work_rect_size_y
        if window.ContentSizeExplicit.y ~= 0.0 then
            work_rect_size_y = window.ContentSizeExplicit.y
        else
            local content_size_y = allow_scrollbar_y and (window.ContentSize and window.ContentSize.y or 0.0) or 0.0
            local window_size_y = window.Size.y - window.WindowPadding.y * 2.0 - (window.DecoOuterSizeY1 + window.DecoOuterSizeY2)
            work_rect_size_y = ImMax(content_size_y, window_size_y)
        end

        window.WorkRect.Min.x = ImTrunc(window.InnerRect.Min.x - window.Scroll.x + ImMax(window.WindowPadding.x, window.WindowBorderSize))
        window.WorkRect.Min.y = ImTrunc(window.InnerRect.Min.y - window.Scroll.y + ImMax(window.WindowPadding.y, window.WindowBorderSize))
        window.WorkRect.Max.x = window.WorkRect.Min.x + work_rect_size_x
        window.WorkRect.Max.y = window.WorkRect.Min.y + work_rect_size_y
        window.ParentWorkRect = window.WorkRect

        -- [LEGACY] Content Region
        -- FIXME-OBSOLETE: window.ContentRegionRect.Max is currently very misleading / partly faulty, but some BeginChild() patterns relies on it.
        -- Unless explicit content size is specified by user, this currently represent the region leading to no scrolling.
        -- Used by:
        -- - Mouse wheel scrolling + many other things
        window.ContentRegionRect.Min.x = window.Pos.x - window.Scroll.x + window.WindowPadding.x + window.DecoOuterSizeX1
        window.ContentRegionRect.Min.y = window.Pos.y - window.Scroll.y + window.WindowPadding.y + window.DecoOuterSizeY1
        window.ContentRegionRect.Max.x = window.ContentRegionRect.Min.x + (window.ContentSizeExplicit.x ~= 0.0 and window.ContentSizeExplicit.x or (window.Size.x - window.WindowPadding.x * 2.0 - (window.DecoOuterSizeX1 + window.DecoOuterSizeX2)))
        window.ContentRegionRect.Max.y = window.ContentRegionRect.Min.y + (window.ContentSizeExplicit.y ~= 0.0 and window.ContentSizeExplicit.y or (window.Size.y - window.WindowPadding.y * 2.0 - (window.DecoOuterSizeY1 + window.DecoOuterSizeY2)))

        -- Setup drawing context
        -- (NB: That term "drawing context / DC" lost its meaning a long time ago. Initially was meant to hold transient data only. Nowadays difference between window. and window.DC. is dubious.)
        window.DC.Indent.x = window.DecoOuterSizeX1 + window.WindowPadding.x - window.Scroll.x
        window.DC.GroupOffset.x = 0.0
        window.DC.ColumnsOffset.x = 0.0

        -- Record the loss of precision of CursorStartPos which can happen due to really large scrolling amount.
        -- This is used by clipper to compensate and fix the most common use case of large scroll area. Easy and cheap, next best thing compared to switching everything to double or ImU64.
        local start_pos_highp_x = window.Pos.x + window.WindowPadding.x - window.Scroll.x + window.DecoOuterSizeX1 + window.DC.ColumnsOffset.x
        local start_pos_highp_y = window.Pos.y + window.WindowPadding.y - window.Scroll.y + window.DecoOuterSizeY1
        ImVec2_CopyV(window.DC.CursorStartPos, start_pos_highp_x, start_pos_highp_y)
        ImVec2_CopyV(window.DC.CursorStartPosLossyness, start_pos_highp_x - window.DC.CursorStartPos.x, start_pos_highp_y - window.DC.CursorStartPos.y)
        ImVec2_Copy(window.DC.CursorPos, window.DC.CursorStartPos)
        ImVec2_Copy(window.DC.CursorPosPrevLine, window.DC.CursorPos)
        ImVec2_Copy(window.DC.CursorMaxPos, window.DC.CursorStartPos)
        ImVec2_Copy(window.DC.IdealMaxPos, window.DC.CursorStartPos)
        ImVec2_CopyV(window.DC.CurrLineSize, 0.0, 0.0)
        ImVec2_CopyV(window.DC.PrevLineSize, 0.0, 0.0)
        window.DC.CurrLineTextBaseOffset = 0.0
        window.DC.PrevLineTextBaseOffset = 0.0
        window.DC.IsSameLine = false
        window.DC.IsSetPos = false

        window.DC.NavLayerCurrent = ImGuiNavLayer.Main
        window.DC.NavLayersActiveMask = window.DC.NavLayersActiveMaskNext
        window.DC.NavLayersActiveMaskNext = 0x00
        window.DC.NavIsScrollPushableX = true
        window.DC.NavHideHighlightOneFrame = false
        window.DC.NavWindowHasScrollY = window.ScrollMax.y > 0.0

        window.DC.MenuBarAppending = false
        window.DC.MenuColumns:Update(style.ItemSpacing.x, window_just_activated_by_user)
        window.DC.TreeDepth = 0
        window.DC.TreeHasStackDataDepthMask = 0x00
        window.DC.TreeRecordsClippedNodesY2Mask = 0x00
        window.DC.ChildWindows:resize(0)
        window.DC.StateStorage = window.StateStorage
        window.DC.CurrentColumns = nil
        window.DC.LayoutType = ImGuiLayoutType.Vertical
        window.DC.ParentLayoutType = (parent_window ~= nil) and parent_window.DC.LayoutType or ImGuiLayoutType.Vertical

        -- Default item width. Make it proportional to window size if window can be manually resized.
        -- (we cannot use AutoFitFramesX/AutoFitFramesY which is a temporary state)
        local is_resizable_width
        if bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0 and not window.DockIsActive then
            is_resizable_width = (window.Size.x > 0.0) and (bit32.band(window.ChildFlags, bit32.bor(ImGuiChildFlags.AutoResizeX, ImGuiChildFlags.AlwaysAutoResize)) == 0)
        else
            is_resizable_width = (window.Size.x > 0.0) and (bit32.band(flags, ImGuiWindowFlags.AlwaysAutoResize) == 0)
        end

        if is_resizable_width then
            window.DC.ItemWidthDefault = ImTrunc(window.Size.x * 0.65)
        else
            window.DC.ItemWidthDefault = ImTrunc(g.FontSize * 16.0)
        end
        window.DC.ItemWidth = window.DC.ItemWidthDefault
        window.DC.ItemWidthStack:resize(0)
        window.DC.TextWrapPos = -1.0 -- Disabled
        window.DC.TextWrapPosStack:resize(0)
        if bit32.band(flags, ImGuiWindowFlags.Modal) ~= 0 then
            window.DC.ModalDimBgColor = ImGui.ColorConvertFloat4ToU32(ImGui.GetStyleColorVec4(ImGuiCol.ModalWindowDimBg))
        end

        if window.AutoFitFramesX > 0 then
            window.AutoFitFramesX = window.AutoFitFramesX - 1
        end
        if window.AutoFitFramesY > 0 then
            window.AutoFitFramesY = window.AutoFitFramesY - 1
        end

        -- Clear SetNextWindowXXX data (can aim to move this higher in the function)
        g.NextWindowData:ClearFlags()

        -- Apply focus (we need to call FocusWindow() AFTER setting DC.CursorStartPos so our initial navigation reference rectangle can start around there)
        -- We ImGuiFocusRequestFlags.UnlessBelowModal to:
        -- - Avoid focusing a window that is created outside of a modal. This will prevent active modal from being closed.
        -- - Position window behind the modal that is not a begin-parent of this window.
        if want_focus then
            ImGui.FocusWindow(window, ImGuiFocusRequestFlags.UnlessBelowModal)
        end
        if want_focus and window == g.NavWindow then
            ImGui.NavInitWindow(window, false) -- <-- this is in the way for us to be able to defer and sort reappearing FocusWindow() calls
        end

        -- Pressing Ctrl+C copy window content into the clipboard
        -- [EXPERIMENTAL] Breaks on nested Begin/End pairs. We need to work that out and add better logging scope.
        -- [EXPERIMENTAL] Text outputs has many issues.
        if g.IO.ConfigWindowsCopyContentsWithCtrlC then
            if g.NavWindow and g.NavWindow.RootWindow == window and g.ActiveId == 0 and ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.C)) then
                ImGui.LogToClipboard(0)
            end
        end

        -- Title bar
        if bit32.band(flags, ImGuiWindowFlags.NoTitleBar) == 0 and not window.DockIsActive then
            open = RenderWindowTitleBarContents(window, ImRect(title_bar_rect.Min.x + window.WindowBorderSize, title_bar_rect.Min.y, title_bar_rect.Max.x - window.WindowBorderSize, title_bar_rect.Max.y), name, open)
        elseif bit32.band(flags, ImGuiWindowFlags.NoTitleBar) == 0 and window.DockIsActive then
            ImGui.LogText("%s\n", string.sub(window.Name, 1, ImGui.FindRenderedTextEnd(window.Name) - 1))
        end

        -- Clear hit test shape every frame
        window.HitTestHoleSize.x = 0; window.HitTestHoleSize.y = 0

        if bit32.band(flags, ImGuiWindowFlags.Tooltip) ~= 0 then
            g.TooltipPreviousWindow = window
        end

        if bit32.band(g.IO.ConfigFlags, ImGuiConfigFlags.DockingEnable) ~= 0 then
            -- Docking: Dragging a dockable window (or any of its child) turns it into a drag and drop source.
            -- We need to do this _before_ we overwrite window.DC.LastItemId below because BeginDockableDragDropSource() also overwrites it.
            if g.MovingWindow == window and bit32.band(window.RootWindowDockTree.Flags, ImGuiWindowFlags.NoDocking) == 0 then
                ImGui.BeginDockableDragDropSource(window)
            end

            -- Docking: Any dockable window can act as a target. For dock node hosts we call BeginDockableDragDropTarget() in DockNodeUpdate() instead.
            if g.DragDropActive and bit32.band(flags, ImGuiWindowFlags.NoDocking) == 0 then
                if g.MovingWindow == nil or g.MovingWindow.RootWindowDockTree ~= window then
                    if window == window.RootWindowDockTree and bit32.band(window.Flags, ImGuiWindowFlags.DockNodeHost) == 0 then
                        ImGui.BeginDockableDragDropTarget(window)
                    end
                end
            end
        end

        -- Set default BgClickFlags
        -- This is set at the end of this function, so UpdateWindowManualResize()/ClampWindowPos() may use last-frame value if overridden by user code.
        -- FIXME: The general intent is that we will later expose config options to default to enable scrolling + select scrolling mouse button.
        if bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0 then
            window.BgClickFlags = parent_window.BgClickFlags
        else
            window.BgClickFlags = g.IO.ConfigWindowsMoveFromTitleBarOnly and ImGuiWindowBgClickFlags.None or ImGuiWindowBgClickFlags.Move
        end

        -- We fill last item data based on Title Bar/Tab, in order for IsItemHovered() and IsItemActive() to be usable after Begin().
        -- This is useful to allow creating context menus on title bar only, etc.
        window.DC.WindowItemStatusFlags = ImGuiItemStatusFlags.None

        if ImGui.IsMouseHoveringRect(title_bar_rect.Min, title_bar_rect.Max, false) then
            window.DC.WindowItemStatusFlags = bit32.bor(window.DC.WindowItemStatusFlags, ImGuiItemStatusFlags.HoveredRect)
        end
        ImGui.SetLastItemDataForWindow(window, title_bar_rect)
    else
        -- Skip refresh always mark active
        if (window.SkipRefresh) then
            SetWindowActiveForSkipRefresh(window)
        end

        -- Append
        ImGui.SetCurrentViewport(window, window.Viewport)
        SetCurrentWindow(window)
        g.NextWindowData:ClearFlags()
        ImGui.SetLastItemDataForWindow(window, window:TitleBarRect())
    end

    if bit32.band(flags, ImGuiWindowFlags.DockNodeHost) == 0 and not window.SkipRefresh then
        ImGui.PushClipRect(window.InnerClipRect.Min, window.InnerClipRect.Max, true)
        -- [Roblox backend] content clip + scroll origin: lets the backend move scrolled content instead of redrawing it
        local dl, cr = window.DrawList, window.DrawList._CmdHeader.ClipRect
        dl._ContentClipX0, dl._ContentClipY0, dl._ContentClipX1, dl._ContentClipY1 = cr.x, cr.y, cr.z, cr.w
        dl._ScrollOriginX, dl._ScrollOriginY = window.Pos.x - window.Scroll.x, window.Pos.y - window.Scroll.y
    end

    -- Clear 'accessed' flag last thing (After PushClipRect which will set the flag. We want the flag to stay false when the default "Debug" window is unused)
    window.WriteAccessed = false
    window.BeginCount = window.BeginCount + 1
    g.NextWindowData:ClearFlags()

    -- Update visibility
    if first_begin_of_the_frame and not window.SkipRefresh then
        -- When we are about to select this tab (which will only be visible on the _next frame_), flag it with a non-zero HiddenFramesCannotSkipItems.
        -- This will have the important effect of actually returning true in Begin() and not setting SkipItems, allowing an earlier submission of the window contents.
        -- This is analogous to regular windows being hidden from one frame.
        -- It is especially important as e.g. nested TabBars would otherwise generate flicker in the form of one empty frame, or focus requests won't be processed.
        if window.DockIsActive and not window.DockTabIsVisible then
            if window.LastFrameJustFocused == g.FrameCount then
                window.HiddenFramesCannotSkipItems = 1
            else
                window.HiddenFramesCanSkipItems = 1
            end
        end

        if (bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0) and (bit32.band(flags, ImGuiWindowFlags.ChildMenu) == 0) then
            -- Child window can be out of sight and have "negative" clip windows.
            -- Mark them as collapsed so commands are skipped earlier (we can't manually collapse them because they have no title bar).
            IM_ASSERT((bit32.band(flags, ImGuiWindowFlags.NoTitleBar) ~= 0) or window.DockIsActive)

            local nav_request = (bit32.band(window.ChildFlags, ImGuiChildFlags.NavFlattened) ~= 0) and (g.NavAnyRequest and g.NavWindow and g.NavWindow.RootWindowForNav == window.RootWindowForNav)

            if not g.LogEnabled and not nav_request then
                if window.OuterRectClipped.Min.x >= window.OuterRectClipped.Max.x or window.OuterRectClipped.Min.y >= window.OuterRectClipped.Max.y then
                    if window.AutoFitFramesX > 0 or window.AutoFitFramesY > 0 then
                        window.HiddenFramesCannotSkipItems = 1
                    else
                        window.HiddenFramesCanSkipItems = 1
                    end
                end
            end

            -- Hide along with parent or if parent is collapsed
            if parent_window and (parent_window.Collapsed or parent_window.HiddenFramesCanSkipItems > 0) then
                window.HiddenFramesCanSkipItems = 1
            end
            if parent_window and parent_window.HiddenFramesCannotSkipItems > 0 then
                window.HiddenFramesCannotSkipItems = 1
            end
        end

        -- Don't render if style alpha is 0.0 at the time of Begin(). This is arbitrary and inconsistent but has been there for a long while (may remove at some point)
        if style.Alpha <= 0.0 then
            window.HiddenFramesCanSkipItems = 1
        end

        -- Update the Hidden flag
        local hidden_regular = (window.HiddenFramesCanSkipItems > 0) or (window.HiddenFramesCannotSkipItems > 0)
        window.Hidden = hidden_regular or (window.HiddenFramesForRenderOnly > 0)

        -- Disable inputs for requested number of frames
        if window.DisableInputsFrames > 0 then
            window.DisableInputsFrames = window.DisableInputsFrames - 1
            window.Flags = bit32.bor(window.Flags, ImGuiWindowFlags.NoInputs)
        end

        -- Update the SkipItems flag, used to early out of all items functions (no layout required)
        local skip_items = false
        if window.Collapsed or not window.Active or hidden_regular then
            if window.AutoFitFramesX <= 0 and window.AutoFitFramesY <= 0 and window.HiddenFramesCannotSkipItems <= 0 then
                skip_items = true
            end
        end
        window.SkipItems = skip_items

        -- Restore NavLayersActiveMaskNext to previous value when not visible, so a CTRL+Tab back can use a safe value.
        if window.SkipItems then
            window.DC.NavLayersActiveMaskNext = window.DC.NavLayersActiveMask
        end
    elseif first_begin_of_the_frame then
        -- Skip refresh mode
        window.SkipItems = true
    end

    if open == nil then open = true end
    return open, not window.SkipItems
end

function ImGui.End()
    local g = GImGui
    local window = g.CurrentWindow

    -- Error checking: verify that user hasn't called End() too many times!
    if (g.CurrentWindowStack.Size <= 1 and g.WithinFrameScopeWithImplicitWindow) then
        IM_ASSERT_USER_ERROR(g.CurrentWindowStack.Size > 1, "Calling End() too many times!")

        return
    end
    local window_stack_data = g.CurrentWindowStack:back()

    -- Error checking: verify that user doesn't directly call End() on a child window.
    if bit32.band(window.Flags, ImGuiWindowFlags.Popup) ~= 0 then
        IM_ASSERT_USER_ERROR(g.WithinEndPopupID == window.ID, "Must call EndPopup() and not End()!")
    end
    if bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0 and bit32.band(window.Flags, ImGuiWindowFlags.DockNodeHost) == 0 and not window.DockIsActive then
        IM_ASSERT_USER_ERROR(g.WithinEndChildID == window.ID, "Must call EndChild() and not End()!")
    end

    -- Close anything that is open
    if window.DC.CurrentColumns then
        ImGui.EndColumns()
    end
    if bit32.band(window.Flags, ImGuiWindowFlags.DockNodeHost) == 0 and not window.SkipRefresh then -- Pop inner window clip rectangle
        ImGui.PopClipRect()
    end
    ImGui.PopFocusScope()

    if window_stack_data.DisabledOverrideReenable and window.RootWindow == window then
        ImGui.EndDisabledOverrideReenable()
    end

    if (window.SkipRefresh) then
        IM_ASSERT(window.DrawList == nil)
        window.DrawList = window.DrawListInst
    end
    if window.CacheSkipItemsBackup ~= nil then -- [Port] SetNextWindowCached()
        window.SkipItems = window.CacheSkipItemsBackup
        window.CacheSkipItemsBackup = nil
    end

    -- Stop logging
    if g.LogWindow == window then -- FIXME: add more options for scope of logging
        ImGui.LogFinish()
    end

    if window.DC.IsSetPos then
        ImGui.ErrorCheckUsingSetCursorPosToExtendParentBoundaries()
    end

    -- Docking: report contents sizes to parent to allow for auto-resize
    if window.DockNode and window.DockTabIsVisible then
        local host_window = window.DockNode.HostWindow -- FIXME-DOCK
        if host_window then
            ImVec2_Copy(host_window.DC.CursorMaxPos, window.DC.CursorMaxPos + window.WindowPadding - host_window.WindowPadding)
        end
    end

    -- Pop from window stack
    ImGuiLastItemData_Copy(g.LastItemData, window_stack_data.ParentLastItemDataBackup)
    if bit32.band(window.Flags, ImGuiWindowFlags.ChildMenu) ~= 0 then
        g.BeginMenuDepth = g.BeginMenuDepth - 1
    end
    if bit32.band(window.Flags, ImGuiWindowFlags.Popup) ~= 0 then
        g.BeginPopupStack:pop_back()
    end

    -- Error handling, state recovery
    if g.IO.ConfigErrorRecovery and window_stack_data.StackSizesInBegin then
        ImGui.ErrorRecoveryTryToRecoverWindowState(window_stack_data.StackSizesInBegin)
    end

    g.CurrentWindowStack:pop_back()

    -- LUA: No "Ternary Operator", since lua (... and (1) or (2)) will eval (1) and (2) no matter what
    -- so something like `SetCurrentWindow((g.CurrentWindowStack.Size == 0) and nil or g.CurrentWindowStack:back().Window)` will error
    if (g.CurrentWindowStack.Size == 0) then
        SetCurrentWindow(nil)
    else
        SetCurrentWindow(g.CurrentWindowStack:back().Window)
    end
    if g.CurrentWindow then
        ImGui.SetCurrentViewport(g.CurrentWindow, g.CurrentWindow.Viewport)
    end
end

--- @param option  ImGuiItemFlags
--- @param enabled bool
function ImGui.PushItemFlag(option, enabled)
    local g = GImGui
    local item_flags = g.CurrentItemFlags
    IM_ASSERT(item_flags == g.ItemFlagsStack:back())

    if enabled then
        item_flags = bit32.bor(item_flags, option)
    else
        item_flags = bit32.band(item_flags, bit32.bnot(option))
    end

    g.CurrentItemFlags = item_flags
    g.ItemFlagsStack:push_back(item_flags)
end

function ImGui.PopItemFlag()
    local g = GImGui
    IM_ASSERT_USER_ERROR_RET(g.ItemFlagsStack.Size > 1, "Calling PopItemFlag() too many times!")
    g.ItemFlagsStack:pop_back()
    g.CurrentItemFlags = g.ItemFlagsStack:back()
end

-- BeginDisabled()/EndDisabled()
-- - Those can be nested but it cannot be used to enable an already disabled section (a single BeginDisabled(true) in the stack is enough to keep everything disabled)
-- - Visually this is currently altering alpha, but it is expected that in a future styling system this would work differently.
-- - Feedback welcome at https://github.com/ocornut/imgui/issues/211
-- - BeginDisabled(false)/EndDisabled() essentially does nothing but is provided to facilitate use of boolean expressions.
--   (as a micro-optimization: if you have tens of thousands of BeginDisabled(false)/EndDisabled() pairs, you might want to reformulate your code to avoid making those calls)
-- - Note: mixing up BeginDisabled() and PushItemFlag(ImGuiItemFlags.Disabled) is currently NOT SUPPORTED.
--- @param disabled? bool
function ImGui.BeginDisabled(disabled)
    if disabled == nil then disabled = true end

    local g = GImGui
    local was_disabled = bit32.band(g.CurrentItemFlags, ImGuiItemFlags.Disabled) ~= 0
    if not was_disabled and disabled then
        g.DisabledAlphaBackup = g.Style.Alpha
        g.Style.Alpha = g.Style.Alpha * g.Style.DisabledAlpha -- PushStyleVar(ImGuiStyleVar.Alpha, g.Style.Alpha * g.Style.DisabledAlpha)
    end
    if was_disabled or disabled then
        g.CurrentItemFlags = bit32.bor(g.CurrentItemFlags, ImGuiItemFlags.Disabled)
    end
    g.ItemFlagsStack:push_back(g.CurrentItemFlags) -- FIXME-OPT: can we simply skip this and use DisabledStackSize?
    g.DisabledStackSize = g.DisabledStackSize + 1
end

function ImGui.EndDisabled()
    local g = GImGui
    IM_ASSERT_USER_ERROR_RET(g.DisabledStackSize > 0, "Calling EndDisabled() too many times!")
    g.DisabledStackSize = g.DisabledStackSize - 1
    local was_disabled = bit32.band(g.CurrentItemFlags, ImGuiItemFlags.Disabled) ~= 0
    -- PopItemFlag()
    g.ItemFlagsStack:pop_back()
    g.CurrentItemFlags = g.ItemFlagsStack:back()
    if was_disabled and bit32.band(g.CurrentItemFlags, ImGuiItemFlags.Disabled) == 0 then
        g.Style.Alpha = g.DisabledAlphaBackup -- PopStyleVar()
    end
end

-- Could have been called BeginDisabledDisable() but it didn't want to be award nominated for most awkward function name.
-- Ideally we would use a shared e.g. BeginDisabled()->BeginDisabledEx() but earlier needs to be optimal.
-- The whole code for this is awkward, will reevaluate if we find a way to implement SetNextItemDisabled().
function ImGui.BeginDisabledOverrideReenable()
    local g = GImGui
    IM_ASSERT(bit32.band(g.CurrentItemFlags, ImGuiItemFlags.Disabled) ~= 0)

    g.CurrentWindowStack.Data[g.CurrentWindowStack.Size].DisabledOverrideReenableAlphaBackup = g.Style.Alpha
    g.Style.Alpha = g.DisabledAlphaBackup
    g.CurrentItemFlags = bit32.band(g.CurrentItemFlags, bit32.bnot(ImGuiItemFlags.Disabled))
    g.ItemFlagsStack:push_back(g.CurrentItemFlags)
    g.DisabledStackSize = g.DisabledStackSize + 1
end

function ImGui.EndDisabledOverrideReenable()
    local g = GImGui
    IM_ASSERT(g.DisabledStackSize > 0)
    g.DisabledStackSize = g.DisabledStackSize - 1
    g.ItemFlagsStack:pop_back()
    g.CurrentItemFlags = g.ItemFlagsStack:back()
    g.Style.Alpha = g.CurrentWindowStack:back().DisabledOverrideReenableAlphaBackup
end

-- Find window given position, search front-to-back
-- - Typically write output back to g.HoveredWindow and g.HoveredWindowUnderMovingWindow.
-- - FIXME: Note that we have an inconsequential lag here: OuterRectClipped is updated in Begin(), so windows moved programmatically
--   with SetWindowPos() and not SetNextWindowPos() will have that rectangle lagging by a frame at the time FindHoveredWindow() is
--   called, aka before the next Begin(). Moving window isn't affected.
-- - The 'find_first_and_in_any_viewport = true' mode is only used by TestEngine. It is simpler to maintain here.
--- @param pos                            ImVec2
--- @param find_first_and_in_any_viewport bool
--- @return ImGuiWindow, ImGuiWindow?
local function FindHoveredWindowEx(pos, find_first_and_in_any_viewport)
    local g = GImGui
    local hovered_window = nil
    local hovered_window_under_moving_window = nil

    -- Special handling for the window being moved: Ignore the mouse viewport check (because it may reset/lose its viewport during the undocking frame)
    hovered_window = g.MovingWindow
    local backup_moving_window_viewport = nil
    if (find_first_and_in_any_viewport == false and g.MovingWindow) then
        backup_moving_window_viewport = g.MovingWindow.Viewport
        g.MovingWindow.Viewport = g.MouseViewport
        if (bit32.band(g.MovingWindow.Flags, ImGuiWindowFlags.NoMouseInputs) == 0) then
            hovered_window = g.MovingWindow
        end
    end

    local padding_regular = g.Style.TouchExtraPadding
    local padding_for_resize = ImMax(g.Style.TouchExtraPadding, ImVec2(g.Style.WindowBorderHoverPadding, g.Style.WindowBorderHoverPadding))

    local window
    local stop_6075 = false
    for i = g.Windows.Size, 1, -1 do
        repeat
        window = g.Windows.Data[i]
        if not window.WasActive or window.Hidden then
            break
        end
        if bit32.band(window.Flags, ImGuiWindowFlags.NoMouseInputs) ~= 0 then
            break
        end

        IM_ASSERT(window.Viewport)
        if (window.Viewport ~= g.MouseViewport) then
            break
        end

        -- Using the clipped AABB, a child window will typically be clipped by its parent (not always)
        local hit_padding
        if bit32.band(window.Flags, bit32.bor(ImGuiWindowFlags.NoResize, ImGuiWindowFlags.AlwaysAutoResize)) ~= 0 then
            hit_padding = padding_regular
        else
            hit_padding = padding_for_resize
        end
        if not window.OuterRectClipped:ContainsWithPad(pos, hit_padding) then
            break
        end

        -- Support for one rectangular hole in any given window
        -- FIXME: Consider generalizing hit-testing override (with more generic data, callback, etc.) (#1512)
        if window.HitTestHoleSize.x ~= 0 then
            local hx, hy = window.Pos.x + window.HitTestHoleOffset.x, window.Pos.y + window.HitTestHoleOffset.y
            if pos.x >= hx and pos.y >= hy and pos.x < hx + window.HitTestHoleSize.x and pos.y < hy + window.HitTestHoleSize.y then
                break -- continue
            end
        end

        if find_first_and_in_any_viewport then
            hovered_window = window
            stop_6075 = true; break
        else
            if hovered_window == nil then
                hovered_window = window
            end

            if hovered_window_under_moving_window == nil and (not g.MovingWindow or window.RootWindowDockTree ~= g.MovingWindow.RootWindowDockTree) then
                hovered_window_under_moving_window = window
            end

            if hovered_window and hovered_window_under_moving_window then
                stop_6075 = true; break
            end
        end

        until true
        if stop_6075 then break end
    end

    if (find_first_and_in_any_viewport == false and g.MovingWindow) then
        g.MovingWindow.Viewport = backup_moving_window_viewport
    end

    return hovered_window, hovered_window_under_moving_window
end

-- TODO:
-- The reason this is exposed in imgui_internal.h is: on touch-based system that don't have hovering, we want to dispatch inputs to the right target (imgui vs imgui+app)
function ImGui.UpdateHoveredWindowAndCaptureFlags(mouse_pos)
    local g = GImGui
    local io = g.IO

    -- FIXME-DPI: This storage was added on 2021/03/31 for test engine, but if we want to multiply WINDOWS_HOVER_PADDING
    -- by DpiScale, we need to make this window-agnostic anyhow, maybe need storing inside ImGuiWindow.
    g.WindowsBorderHoverPadding = ImMax(ImMax(g.Style.TouchExtraPadding.x, g.Style.TouchExtraPadding.y), g.Style.WindowBorderHoverPadding)

    -- Find the window hovered by mouse:
    -- - Child windows can extend beyond the limit of their parent so we need to derive HoveredRootWindow from HoveredWindow.
    -- - When moving a window we can skip the search, which also conveniently bypasses the fact that window.WindowRectClipped is lagging as this point of the frame.
    -- - We also support the moved window toggling the NoInputs flag after moving has started in order to be able to detect windows below it, which is useful for e.g. docking mechanisms.
    local clear_hovered_windows = false
    g.HoveredWindow, g.HoveredWindowUnderMovingWindow = FindHoveredWindowEx(mouse_pos, false)
    IM_ASSERT(g.HoveredWindow == nil or g.HoveredWindow == g.MovingWindow or g.HoveredWindow.Viewport == g.MouseViewport)
    g.HoveredWindowBeforeClear = g.HoveredWindow

    -- Modal windows prevents mouse from hovering behind them.
    local modal_window = ImGui.GetTopMostPopupModal()
    if modal_window and g.HoveredWindow and not ImGui.IsWindowWithinBeginStackOf(g.HoveredWindow.RootWindow, modal_window) then -- FIXME-MERGE: RootWindowDockTree ?
        clear_hovered_windows = true
    end

    -- Disabled mouse hovering (we don't currently clear MousePos, we could)
    if bit32.band(io.ConfigFlags, ImGuiConfigFlags.NoMouse) ~= 0 then
        clear_hovered_windows = true
    end

    -- We track click ownership. When clicked outside of a window the click is owned by the application and
    -- won't report hovering nor request capture even while dragging over our windows afterward.
    local has_open_popup = (g.OpenPopupStack.Size > 0)
    local has_open_modal = (modal_window ~= nil)
    local mouse_earliest_down = -1
    local mouse_any_down = false

    for i = 0, 2 do -- IM_COUNTOF(io.MouseDown)
        if io.MouseClicked[i] then
            io.MouseDownOwned[i] = (g.HoveredWindow ~= nil) or has_open_popup
            io.MouseDownOwnedUnlessPopupClose[i] = (g.HoveredWindow ~= nil) or has_open_modal
        end

        mouse_any_down = mouse_any_down or io.MouseDown[i]
        if (io.MouseDown[i] or io.MouseReleased[i]) then -- Increase release frame for our evaluation of earliest button (#1392)
            if (mouse_earliest_down == -1 or (io.MouseClickedTime[i] < io.MouseClickedTime[mouse_earliest_down])) then
                mouse_earliest_down = i
            end
        end
    end

    local mouse_avail = (mouse_earliest_down == -1) or io.MouseDownOwned[mouse_earliest_down]
    local mouse_avail_unless_popup_close = (mouse_earliest_down == -1) or io.MouseDownOwnedUnlessPopupClose[mouse_earliest_down]

    -- If mouse was first clicked outside of ImGui bounds we also cancel out hovering.
    -- FIXME: For patterns of drag and drop across OS windows, we may need to rework/remove this test (first committed 311c0ca9 on 2015/02)
    local mouse_dragging_extern_payload = g.DragDropActive and bit32.band(g.DragDropSourceFlags, ImGuiDragDropFlags.SourceExtern) ~= 0
    if not mouse_avail and not mouse_dragging_extern_payload then
        clear_hovered_windows = true
    end

    if clear_hovered_windows then
        g.HoveredWindow = nil
        g.HoveredWindowUnderMovingWindow = nil
    end

    -- Update io.WantCaptureMouse for the user application (true = dispatch mouse info to Dear ImGui only, false = dispatch mouse to Dear ImGui + underlying app)
    -- Update io.WantCaptureMouseAllowPopupClose (experimental) to give a chance for app to react to popup closure with a drag
    if (g.WantCaptureMouseNextFrame ~= -1) then
        io.WantCaptureMouse = (g.WantCaptureMouseNextFrame ~= 0)
        io.WantCaptureMouseUnlessPopupClose = io.WantCaptureMouse
    else
        io.WantCaptureMouse = (mouse_avail and (g.HoveredWindow ~= nil or mouse_any_down)) or has_open_popup
        io.WantCaptureMouseUnlessPopupClose = (mouse_avail_unless_popup_close and (g.HoveredWindow ~= nil or mouse_any_down)) or has_open_modal
    end

    -- Update io.WantCaptureKeyboard for the user application (true = dispatch keyboard info to Dear ImGui only, false = dispatch keyboard info to Dear ImGui + underlying app)
    io.WantCaptureKeyboard = false
    if bit32.band(io.ConfigFlags, ImGuiConfigFlags.NoKeyboard) == 0 then
        if (g.ActiveId ~= 0) or (modal_window ~= nil) then
            io.WantCaptureKeyboard = true
        elseif io.NavActive and bit32.band(io.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard) ~= 0 and io.ConfigNavCaptureKeyboard then
            io.WantCaptureKeyboard = true
        end
    end
    if g.WantCaptureKeyboardNextFrame ~= -1 then -- Manual override
        io.WantCaptureKeyboard = (g.WantCaptureKeyboardNextFrame ~= 0)
    end

    -- Update io.WantTextInput flag, this is to allow systems without a keyboard (e.g. mobile, hand-held) to show a software keyboard if possible
    io.WantTextInput = (g.WantTextInputNextFrame ~= -1) and (g.WantTextInputNextFrame ~= 0) or false
end

--- @param key          ImGuiKey
--- @param v            bool
--- @param analog_value float
function ImGui.UpdateAliasKey(key, v, analog_value)
    IM_ASSERT(ImGui.IsAliasKey(key))
    local key_data = ImGui.GetKeyData(nil, key)
    key_data.Down = v
    key_data.AnalogValue = analog_value
end

-- [Internal] Do not use directly
function ImGui.GetMergedModsFromKeys()
    local g = GImGui
    -- Bypass IsKeyDown() for the unlikely case where user used a ImGuiInputFlags.LockXXXX on those.
    local mods = 0

    if ImGui.GetKeyData(g, ImGuiMod_Ctrl).Down then mods  = bit32.bor(mods, ImGuiMod_Ctrl) end
    if ImGui.GetKeyData(g, ImGuiMod_Shift).Down then mods = bit32.bor(mods, ImGuiMod_Shift) end
    if ImGui.GetKeyData(g, ImGuiMod_Alt).Down then mods   = bit32.bor(mods, ImGuiMod_Alt) end
    if ImGui.GetKeyData(g, ImGuiMod_Super).Down then mods = bit32.bor(mods, ImGuiMod_Super) end

    return mods
end

function ImGui.UpdateKeyboardInputs()
    local g = GImGui
    local io = g.IO

    if bit32.band(io.ConfigFlags, ImGuiConfigFlags.NoKeyboard) ~= 0 then
        io:ClearInputKeys()
    end

    -- Update aliases
    for n = 0, 2 do -- TODO: ImGuiMouseButton.COUNT - 1
        ImGui.UpdateAliasKey(ImGui.MouseButtonToKey(n), io.MouseDown[n], io.MouseDown[n] and 1.0 or 0.0)
    end
    ImGui.UpdateAliasKey(ImGuiKey.MouseWheelX, io.MouseWheelH ~= 0.0, io.MouseWheelH)
    ImGui.UpdateAliasKey(ImGuiKey.MouseWheelY, io.MouseWheel ~= 0.0, io.MouseWheel)

    -- Synchronize io.KeyMods and io.KeyCtrl/io.KeyShift/etc. values.
    -- - New backends (1.87+): send io.AddKeyEvent(ImGuiMod_XXX) ->                                      -> (here) deriving io.KeyMods + io.KeyXXX from key array.
    -- - Legacy backends:      set io.KeyXXX bools               -> (above) set key array from io.KeyXXX -> (here) deriving io.KeyMods + io.KeyXXX from key array.
    -- So with legacy backends the 4 values will do a unnecessary back-and-forth but it makes the code simpler and future facing.
    local prev_key_mods = io.KeyMods
    io.KeyMods = ImGui.GetMergedModsFromKeys()
    io.KeyCtrl = bit32.band(io.KeyMods, ImGuiMod_Ctrl) ~= 0
    io.KeyShift = bit32.band(io.KeyMods, ImGuiMod_Shift) ~= 0
    io.KeyAlt = bit32.band(io.KeyMods, ImGuiMod_Alt) ~= 0
    io.KeySuper = bit32.band(io.KeyMods, ImGuiMod_Super) ~= 0
    if prev_key_mods ~= io.KeyMods then
        g.LastKeyModsChangeTime = g.Time
    end
    if prev_key_mods ~= io.KeyMods and prev_key_mods == 0 then
        g.LastKeyModsChangeFromNoneTime = g.Time
    end

    -- Clear gamepad data if disabled
    if bit32.band(io.BackendFlags, ImGuiBackendFlags.HasGamepad) == 0 then
        for key = ImGuiKey_Gamepad_BEGIN, ImGuiKey_Gamepad_END - 1 do
            io.KeysData[key - ImGuiKey.NamedKey_BEGIN].Down = false
            io.KeysData[key - ImGuiKey.NamedKey_BEGIN].AnalogValue = 0.0
        end
    end

    -- Update keys
    for key = ImGuiKey.NamedKey_BEGIN, ImGuiKey.NamedKey_END - 1 do
        local key_data = io.KeysData[key - ImGuiKey.NamedKey_BEGIN]
        key_data.DownDurationPrev = key_data.DownDuration
        if key_data.Down then
            if key_data.DownDuration < 0.0 then
                key_data.DownDuration = 0.0
            else
                key_data.DownDuration = key_data.DownDuration + io.DeltaTime
            end
        else
            key_data.DownDuration = -1.0
        end
        if key_data.DownDuration == 0.0 then
            if ImGui.IsKeyboardKey(key) then
                g.LastKeyboardKeyPressTime = g.Time
            elseif key == ImGuiKey.ReservedForModCtrl or key == ImGuiKey.ReservedForModShift or key == ImGuiKey.ReservedForModAlt or key == ImGuiKey.ReservedForModSuper then
                g.LastKeyboardKeyPressTime = g.Time
            end
        end
    end

    -- Update keys/input owner (named keys only): one entry per key
    for key = ImGuiKey.NamedKey_BEGIN, ImGuiKey.NamedKey_END - 1 do
        local key_data = io.KeysData[key - ImGuiKey.NamedKey_BEGIN]
        local owner_data = g.KeysOwnerData[key - ImGuiKey.NamedKey_BEGIN]
        owner_data.OwnerCurr = owner_data.OwnerNext
        if not key_data.Down then -- Important: ownership is released on the frame after a release. Ensure a 'MouseDown -> CloseWindow -> MouseUp' chain doesn't lead to someone else seeing the MouseUp.
            owner_data.OwnerNext = ImGuiKeyOwner_NoOwner
        end
        owner_data.LockThisFrame = owner_data.LockUntilRelease and key_data.Down
        owner_data.LockUntilRelease = owner_data.LockUntilRelease and key_data.Down  -- Clear LockUntilRelease when key is not Down anymore
    end

    -- Update key routing (for e.g. shortcuts)
    ImGui.UpdateKeyRoutingTable(g.KeysRoutingTable)
end

function ImGui.UpdateMouseInputs()
    local g = GImGui
    local io = g.IO

    -- Mouse Wheel swapping flag
    -- As a standard behavior holding Shift while using Vertical Mouse Wheel triggers Horizontal scroll instead
    -- - We avoid doing it on OSX as it the OS input layer handles this already.
    -- - FIXME: However this means when running on OSX over Emscripten, Shift+WheelY will incur two swapping (1 in OS, 1 here), canceling the feature.
    -- - FIXME: When we can distinguish e.g. touchpad scroll events from mouse ones, we'll set this accordingly based on input source.
    io.MouseWheelRequestAxisSwap = io.KeyShift and not io.ConfigMacOSXBehaviors

    -- Round mouse position to avoid spreading non-rounded position (e.g. UpdateManualResize doesn't support them well)
    if (ImGui.IsMousePosValid(io.MousePos)) then
        local x_val = ImFloor(io.MousePos.x)
        local y_val = ImFloor(io.MousePos.y)

        io.MousePos = ImVec2(x_val, y_val)
        g.MouseLastValidPos = ImVec2(x_val, y_val)
    end

    -- If mouse just appeared or disappeared (usually denoted by -FLT_MAX components) we cancel out movement in MouseDelta
    if (ImGui.IsMousePosValid(io.MousePos) and ImGui.IsMousePosValid(io.MousePosPrev)) then
        io.MouseDelta = io.MousePos - io.MousePosPrev
    else
        io.MouseDelta = ImVec2(0.0, 0.0)
    end

    -- Update stationary timer.
    -- FIXME: May need to rework again to have some tolerance for occasional small movement, while being functional on high-framerates.
    local mouse_stationary_threshold = (io.MouseSource == ImGuiMouseSource.Mouse) and 2.0 or 3.0 -- Slightly higher threshold for ImGuiMouseSource.TouchScreen/ImGuiMouseSource.Pen, may need rework.
    local mouse_stationary = (ImLengthSqr(io.MouseDelta) <= mouse_stationary_threshold * mouse_stationary_threshold)
    g.MouseStationaryTimer = mouse_stationary and (g.MouseStationaryTimer + io.DeltaTime) or 0.0
    -- IMGUI_DEBUG_LOG("%.4f\n", g.MouseStationaryTimer)

    -- If mouse moved we re-enable mouse hovering in case it was disabled by keyboard/gamepad. In theory should use a >0.0f threshold but would need to reset in everywhere we set this to true.
    if io.MouseDelta.x ~= 0.0 or io.MouseDelta.y ~= 0.0 then
        g.NavHighlightItemUnderNav = false
    end

    for i = 0, 2 do -- IM_COUNTOF(io.MouseDown)
        io.MouseClicked[i] = io.MouseDown[i] and (io.MouseDownDuration[i] < 0.0)
        io.MouseClickedCount[i] = 0 -- Will be filled below
        io.MouseReleased[i] = not io.MouseDown[i] and (io.MouseDownDuration[i] >= 0.0)
        if (io.MouseReleased[i]) then
            io.MouseReleasedTime[i] = g.Time
        end
        io.MouseDownDurationPrev[i] = io.MouseDownDuration[i]
        if io.MouseDown[i] then
            if io.MouseDownDuration[i] < 0.0 then
                io.MouseDownDuration[i] = 0.0
            else
                io.MouseDownDuration[i] = io.MouseDownDuration[i] + io.DeltaTime
            end
        else
            io.MouseDownDuration[i] = -1.0
        end

        if io.MouseClicked[i] then
            local is_repeated_click = false
            if (g.Time - io.MouseClickedTime[i]) < io.MouseDoubleClickTime then
                local delta_from_click_pos
                if ImGui.IsMousePosValid(io.MousePos) then
                    delta_from_click_pos = io.MousePos - io.MouseClickedPos[i]
                else
                    delta_from_click_pos = ImVec2(0.0, 0.0)
                end

                if ImLengthSqr(delta_from_click_pos) < io.MouseDoubleClickMaxDist * io.MouseDoubleClickMaxDist then
                    is_repeated_click = true
                end
            end

            if is_repeated_click then
                io.MouseClickedLastCount[i] = io.MouseClickedLastCount[i] + 1
            else
                io.MouseClickedLastCount[i] = 1
            end

            io.MouseClickedTime[i] = g.Time
            io.MouseClickedPos[i] = io.MousePos
            io.MouseClickedCount[i] = io.MouseClickedLastCount[i]
            ImVec2_Copy(io.MouseDragMaxDistanceAbs[i], ImVec2(0.0, 0.0))
            io.MouseDragMaxDistanceSqr[i] = 0.0
        elseif io.MouseDown[i] then
            -- Maintain the maximum distance we reaching from the initial click position, which is used with dragging threshold
            local delta_from_click_pos
            if ImGui.IsMousePosValid(io.MousePos) then
                delta_from_click_pos = (io.MousePos - io.MouseClickedPos[i])
            else
                delta_from_click_pos = ImVec2(0.0, 0.0)
            end
            io.MouseDragMaxDistanceSqr[i] = ImMax(io.MouseDragMaxDistanceSqr[i], ImLengthSqr(delta_from_click_pos))
            io.MouseDragMaxDistanceAbs[i].x = ImMax(io.MouseDragMaxDistanceAbs[i].x, (delta_from_click_pos.x < 0.0) and -delta_from_click_pos.x or delta_from_click_pos.x)
            io.MouseDragMaxDistanceAbs[i].y = ImMax(io.MouseDragMaxDistanceAbs[i].y, (delta_from_click_pos.y < 0.0) and -delta_from_click_pos.y or delta_from_click_pos.y)
        end

        -- We provide io.MouseDoubleClicked[] as a legacy service
        io.MouseDoubleClicked[i] = (io.MouseClickedCount[i] == 2)

        -- Clicking any mouse button reactivate mouse hovering which may have been deactivated by keyboard/gamepad navigation
        if (io.MouseClicked[i]) then
            g.NavHighlightItemUnderNav = false
        end
    end
end

--- @param window?      ImGuiWindow
--- @param wheel_amount float
local function LockWheelingWindow(window, wheel_amount)
    local g = GImGui
    if window then
        g.WheelingWindowReleaseTimer = ImMin(g.WheelingWindowReleaseTimer + ImAbs(wheel_amount) * WINDOWS_MOUSE_WHEEL_SCROLL_LOCK_TIMER, WINDOWS_MOUSE_WHEEL_SCROLL_LOCK_TIMER)
    else
        g.WheelingWindowReleaseTimer = 0.0
    end
    if (g.WheelingWindow == window) then
        return
    end
    -- IMGUI_DEBUG_LOG_IO("[io] LockWheelingWindow() \"%s\"\n", window ? window->Name : "NULL")
    g.WheelingWindow = window
    ImVec2_Copy(g.WheelingWindowRefMousePos, g.IO.MousePos)
    if window == nil then
        g.WheelingWindowStartFrame = -1
        g.WheelingAxisAvg = ImVec2(0.0, 0.0)
    end
end

--- @param wheel ImVec2
--- @return ImGuiWindow?
local function FindBestWheelingWindow(wheel)
    -- For each axis, find window in the hierarchy that may want to use scrolling
    local g = GImGui
    local windows = {nil, nil}
    for axis = ImGuiAxis.X, ImGuiAxis.Y do
        if wheel[axis] ~= 0.0 then
            windows[axis] = g.HoveredWindow
            local window = g.HoveredWindow
            while bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0 do
                -- Bubble up into parent window if:
                -- - a child window doesn't allow any scrolling.
                -- - a child window has the ImGuiWindowFlags.NoScrollWithMouse flag.
                -- -- - a child window doesn't need scrolling because it is already at the edge for the direction we are going in (FIXME-WIP)
                local has_scrolling = (window.ScrollMax[axis] ~= 0.0)
                local inputs_disabled = (bit32.band(window.Flags, ImGuiWindowFlags.NoScrollWithMouse) ~= 0) and not (bit32.band(window.Flags, ImGuiWindowFlags.NoMouseInputs) ~= 0)
                -- local scrolling_past_limits = (wheel_v < 0.0) and (window.Scroll[axis] <= 0.0) or (window.Scroll[axis] >= window.ScrollMax[axis])

                if has_scrolling and not inputs_disabled then -- and not scrolling_past_limits
                    break -- select this window
                end

                windows[axis] = window.ParentWindow
                window = window.ParentWindow
            end
        end
    end
    if windows[1] == nil and windows[2] == nil then
        return nil
    end

    -- If there's only one window or only one axis then there's no ambiguity
    if (windows[1] == windows[2] or windows[1] == nil or windows[2] == nil) then
        return windows[2] and windows[2] or windows[1]
    end

    -- If candidate are different windows we need to decide which one to prioritize
    -- - First frame: only find a winner if one axis is zero.
    -- - Subsequent frames: only find a winner when one is more than the other.
    if (g.WheelingWindowStartFrame == -1) then
        g.WheelingWindowStartFrame = g.FrameCount
    end
    if ((g.WheelingWindowStartFrame == g.FrameCount and wheel.x ~= 0.0 and wheel.y ~= 0.0) or (g.WheelingAxisAvg.x == g.WheelingAxisAvg.y)) then
        ImVec2_Copy(g.WheelingWindowWheelRemainder, wheel)

        return nil
    end
    return (g.WheelingAxisAvg.x > g.WheelingAxisAvg.y) and windows[1] or windows[2]
end

-- Called by NewFrame()
function ImGui.UpdateMouseWheel()
    -- Reset the locked window if we move the mouse or after the timer elapses.
    -- FIXME: Ideally we could refactor to have one timer for "changing window w/ same axis" and a shorter timer for "changing window or axis w/ other axis" (#3795)
    local g = GImGui
    if g.WheelingWindow ~= nil then
        g.WheelingWindowReleaseTimer = g.WheelingWindowReleaseTimer - g.IO.DeltaTime
        if ImGui.IsMousePosValid() and ImLengthSqr(g.IO.MousePos - g.WheelingWindowRefMousePos) > g.IO.MouseDragThreshold * g.IO.MouseDragThreshold then
            g.WheelingWindowReleaseTimer = 0.0
        end

        if g.WheelingWindowReleaseTimer <= 0.0 then
            LockWheelingWindow(nil, 0.0)
        end
    end

    local mouse_window = g.WheelingWindow and g.WheelingWindow or g.HoveredWindow
    if not mouse_window or mouse_window.Collapsed then
        return
    end

    local owner_id = mouse_window.ID
    local wheel = ImVec2()
    wheel.x = ImGui.TestKeyOwner(ImGuiKey.MouseWheelX, owner_id) and g.IO.MouseWheelH or 0.0
    wheel.y = ImGui.TestKeyOwner(ImGuiKey.MouseWheelY, owner_id) and g.IO.MouseWheel or 0.0
    -- IMGUI_DEBUG_LOG("MouseWheel X:%.3f Y:%.3f\n", wheel_x, wheel_y)
    if g.WheelingWindow ~= nil then
        ImGui.SetKeyOwner(ImGuiKey.MouseWheelX, owner_id)
        ImGui.SetKeyOwner(ImGuiKey.MouseWheelY, owner_id)
    end

    -- Zoom / Scale window
    -- FIXME-OBSOLETE: This is an old feature, it still works but pretty much nobody is using it and may be best redesigned.
    if wheel.y ~= 0.0 and g.IO.KeyCtrl and g.IO.FontAllowUserScaling then
        LockWheelingWindow(mouse_window, wheel.y)
        local window = mouse_window
        local new_font_scale = ImClamp(window.FontWindowScale + g.IO.MouseWheel * 0.10, 0.50, 2.50)
        local scale = new_font_scale / window.FontWindowScale
        window.FontWindowScale = new_font_scale
        if window == window.RootWindow then
            local offset = window.Size * (1.0 - scale) * (g.IO.MousePos - window.Pos) / window.Size
            ImGui.SetWindowPos(window, window.Pos + offset, 0)
            -- MarkIniSettingsDirty(window)
        end
        return
    end
    if g.IO.KeyCtrl then
        return
    end

    -- Mouse wheel scrolling
    -- Read about io.MouseWheelRequestAxisSwap and its issue on Mac+Emscripten in UpdateMouseInputs()
    if (g.IO.MouseWheelRequestAxisSwap) then
        wheel = ImVec2(wheel.y, 0.0)
    end

    -- Maintain a rough average of moving magnitude on both axes
    -- FIXME: should by based on wall clock time rather than frame-counter
    g.WheelingAxisAvg.x = ImStd.ImExponentialMovingAverage(g.WheelingAxisAvg.x, ImAbs(wheel.x), 30)
    g.WheelingAxisAvg.y = ImStd.ImExponentialMovingAverage(g.WheelingAxisAvg.y, ImAbs(wheel.y), 30)

    -- In the rare situation where FindBestWheelingWindow() had to defer first frame of wheeling due to ambiguous main axis, reinject it now.
    wheel = wheel + g.WheelingWindowWheelRemainder
    g.WheelingWindowWheelRemainder = ImVec2(0.0, 0.0)
    if (wheel.x == 0.0 and wheel.y == 0.0) then
        return
    end

    -- Mouse wheel scrolling: find target and apply
    -- - don't renew lock if axis doesn't apply on the window.
    -- - select a main axis when both axes are being moved.
    local window
    if g.WheelingWindow then
        window = g.WheelingWindow
    else
        window = FindBestWheelingWindow(wheel)
    end
    if window then
        if not (bit32.band(window.Flags, ImGuiWindowFlags.NoScrollWithMouse) ~= 0) and not (bit32.band(window.Flags, ImGuiWindowFlags.NoMouseInputs) ~= 0) then
            local do_scroll = { wheel.x ~= 0.0 and window.ScrollMax.x ~= 0.0, wheel.y ~= 0.0 and window.ScrollMax.y ~= 0.0 }

            if do_scroll[ImGuiAxis.X] and do_scroll[ImGuiAxis.Y] then
                do_scroll[(g.WheelingAxisAvg.x > g.WheelingAxisAvg.y) and ImGuiAxis.Y or ImGuiAxis.X] = false
            end

            if do_scroll[ImGuiAxis.X] then
                LockWheelingWindow(window, wheel.x)
                local max_step = window.InnerRect:GetWidth() * 0.67
                local scroll_step = ImTrunc(ImMin(2 * window.FontRefSize, max_step))
                ImGui.SetScrollX(window, window.Scroll.x - wheel.x * scroll_step)
                g.WheelingWindowScrolledFrame = g.FrameCount
            end

            if do_scroll[ImGuiAxis.Y] then
                LockWheelingWindow(window, wheel.y)
                local max_step = window.InnerRect:GetHeight() * 0.67
                local scroll_step = ImTrunc(ImMin(5 * window.FontRefSize, max_step))
                ImGui.SetScrollY(window, window.Scroll.y - wheel.y * scroll_step)
                g.WheelingWindowScrolledFrame = g.FrameCount
            end
        end
    end
end

-- Called once a frame. Followed by SetCurrentFont() which sets up the remaining data.
-- FIXME-VIEWPORT: the concept of a single ClipRectFullscreen is not ideal!
local function SetupDrawListSharedData()
    local g = GImGui
    local virtual_space = ImRect(FLT_MAX, FLT_MAX, -FLT_MAX, -FLT_MAX)
    for _, viewport in g.Viewports:iter() do
        virtual_space:Add(viewport:GetMainRect())
    end
    g.DrawListSharedData.ClipRectFullscreen = virtual_space:ToVec4()
    g.DrawListSharedData.CurveTessellationTol = g.Style.CurveTessellationTol
    g.DrawListSharedData:SetCircleTessellationMaxError(g.Style.CircleTessellationMaxError)
    g.DrawListSharedData.InitialFlags = ImDrawListFlags.None
    if g.Style.AntiAliasedLines then
        g.DrawListSharedData.InitialFlags = bit32.bor(g.DrawListSharedData.InitialFlags, ImDrawListFlags.AntiAliasedLines)
    end
    if g.Style.AntiAliasedLinesUseTex and not bit32.band(g.IO.Fonts.Flags, ImFontAtlasFlags.NoBakedLines) then
        g.DrawListSharedData.InitialFlags = bit32.bor(g.DrawListSharedData.InitialFlags, ImDrawListFlags.AntiAliasedLinesUseTex)
    end
    if g.Style.AntiAliasedFill then
        g.DrawListSharedData.InitialFlags = bit32.bor(g.DrawListSharedData.InitialFlags, ImDrawListFlags.AntiAliasedFill)
    end
    if bit32.band(g.IO.BackendFlags, ImGuiBackendFlags.RendererHasVtxOffset) then
        g.DrawListSharedData.InitialFlags = bit32.bor(g.DrawListSharedData.InitialFlags, ImDrawListFlags.AllowVtxOffset)
    end
    g.DrawListSharedData.InitialFringeScale = 1.0
end

--- @param viewport ImGuiViewportP
local function InitViewportDrawData(viewport)
    local g = GImGui
    local draw_data = viewport.DrawDataP

    viewport.DrawData = draw_data -- Make publicly accessible
    viewport.DrawDataBuilder.Layers[1] = draw_data.CmdLists
    viewport.DrawDataBuilder.Layers[2] = viewport.DrawDataBuilder.LayerData1
    viewport.DrawDataBuilder.Layers[1]:resize(0)
    viewport.DrawDataBuilder.Layers[2]:resize(0)

    -- When minimized, we report draw_data->DisplaySize as zero to be consistent with non-viewport mode,
    -- and to allow applications/backends to easily skip rendering.
    -- FIXME: Note that we however do NOT attempt to report "zero drawlist / vertices" into the ImDrawData structure.
    -- This is because the work has been done already, and its wasted! We should fix that and add optimizations for
    -- it earlier in the pipeline, rather than pretend to hide the data at the end of the pipeline.
    local is_minimized = bit32.band(viewport.Flags, ImGuiViewportFlags.IsMinimized) ~= 0

    draw_data.Valid         = true
    draw_data.FrameCount    = g.FrameCount
    draw_data.TotalVtxCount = 0
    draw_data.TotalIdxCount = 0
    draw_data.DisplayPos    = viewport.Pos
    if is_minimized then
        draw_data.DisplaySize = ImVec2(0.0, 0.0)
    else
        ImVec2_Copy(draw_data.DisplaySize, viewport.Size)
    end
    if viewport.FramebufferScale.x ~= 0.0 then
        draw_data.FramebufferScale = viewport.FramebufferScale
    else
        draw_data.FramebufferScale = g.IO.DisplayFramebufferScale
    end

    draw_data.OwnerViewport = viewport
    draw_data.Textures      = g.PlatformIO.Textures
end

-- FIXME-DPI: PLEASE DO NOT USE. I don't want to formalize this just yet. Because reasons.
function ImGui.GetScale()
    local g = GImGui
    return g.Style._MainScale
end

--- @return ImGuiWindow
function ImGui.GetCurrentWindowRead()
    local g = GImGui
    return g.CurrentWindow
end

--- @return ImGuiWindow

function ImGui.GetCurrentWindow()
    local g = GImGui
    g.CurrentWindow.WriteAccessed = true
    return g.CurrentWindow
end

-- Push a clipping rectangle for both ImGui logic (hit-testing etc.) and low-level ImDrawList rendering.
-- - When using this function it is sane to ensure that float are perfectly rounded to integer values,
--   so that e.g. (int)(max.x-min.x) in user's render produce correct result.
-- - If the code here changes, may need to update code of functions like NextColumn() and PushColumnClipRect():
--   some frequently called functions which to modify both channels and clipping simultaneously tend to use the
--   more specialized SetWindowClipRectBeforeSetChannel() to avoid extraneous updates of underlying ImDrawCmds.
-- - This is analogous to PushFont()/PopFont() in the sense that are a mixing a global stack and a window stack,
--   which in the case of ClipRect is not so problematic but tends to be more restrictive for fonts.
--- @param clip_rect_min                     ImVec2
--- @param clip_rect_max                     ImVec2
--- @param intersect_with_current_clip_rect? bool

function ImGui.PushClipRect(clip_rect_min, clip_rect_max, intersect_with_current_clip_rect)
    local window = GImGui.CurrentWindow -- [Luau] inline GetCurrentWindow()
    window.WriteAccessed = true
    local draw_list = window.DrawList
    draw_list:PushClipRect(clip_rect_min, clip_rect_max, intersect_with_current_clip_rect)
    local stack = draw_list._ClipRectStack
    ImRect_CopyFromV4(window.ClipRect, stack.Data[stack.Size]) -- [Luau] inline back()
end

function ImGui.PopClipRect()
    local window = GImGui.CurrentWindow -- [Luau] inline GetCurrentWindow()
    window.WriteAccessed = true
    local draw_list = window.DrawList
    draw_list:PopClipRect()
    local stack = draw_list._ClipRectStack
    ImRect_CopyFromV4(window.ClipRect, stack.Data[stack.Size]) -- [Luau] inline back()
end

--- @param viewport      ImGuiViewportP
--- @param drawlist_no   size_t         # background(1), foreground(2)
--- @param drawlist_name string
--- @return ImDrawList
local function GetViewportBgFgDrawList(viewport, drawlist_no, drawlist_name)
    -- Create the draw list on demand, because they are not frequently used for all viewports
    local g = GImGui
    IM_ASSERT(drawlist_no <= 2) -- IM_COUNTOF(viewport->BgFgDrawLists)
    local draw_list = viewport.BgFgDrawLists[drawlist_no]
    if draw_list == nil then
        draw_list = ImDrawList(g.DrawListSharedData)
        draw_list._OwnerName = drawlist_name
        viewport.BgFgDrawLists[drawlist_no] = draw_list
    end

    -- Our ImDrawList system requires that there is always a command
    if viewport.BgFgDrawListsLastTimeActive[drawlist_no] ~= g.Time then
        draw_list:_ResetForNewFrame()
        draw_list:PushTexture(g.IO.Fonts.TexRef)
        draw_list:PushClipRect(viewport.Pos, viewport.Pos + viewport.Size, false)
        viewport.BgFgDrawListsLastTimeActive[drawlist_no] = g.Time
    end

    return draw_list
end

--- @param viewport? ImGuiViewport
function ImGui.GetBackgroundDrawList(viewport)
    local g = GImGui

    if (viewport == nil) then
        viewport = g.CurrentWindow.Viewport
    end

    --- @cast viewport ImGuiViewportP
    return GetViewportBgFgDrawList(viewport, 1, "##Background")
end

--- @param viewport? ImGuiViewport
function ImGui.GetForegroundDrawList(viewport)
    local g = GImGui

    if (viewport == nil) then
        viewport = g.CurrentWindow.Viewport
    end

    --- @cast viewport ImGuiViewportP
    return GetViewportBgFgDrawList(viewport, 2, "##Foreground")
end

-- FIXME: Add a more explicit sort order in the window structure.
--- @param lhs ImGuiWindow
--- @param rhs ImGuiWindow
local function ChildWindowComparer(lhs, rhs)
    local a, b = lhs, rhs
    local d = (bit32.band(a.Flags, ImGuiWindowFlags.Popup) ~= 0 and 1 or 0) - (bit32.band(b.Flags, ImGuiWindowFlags.Popup) ~= 0 and 1 or 0)
    if d ~= 0 then
        return (d < 0)
    end
    d = (bit32.band(a.Flags, ImGuiWindowFlags.Tooltip) ~= 0 and 1 or 0) - (bit32.band(b.Flags, ImGuiWindowFlags.Tooltip) ~= 0 and 1 or 0)
    if d ~= 0 then
        return (d < 0)
    end
    return (a.BeginOrderWithinParent - b.BeginOrderWithinParent < 0)
end

--- @param out_sorted_windows ImVector<ImGuiWindow>
--- @param window             ImGuiWindow
local function AddWindowToSortBuffer(out_sorted_windows, window)
    out_sorted_windows:push_back(window)
    if window.Active then
        local count = window.DC.ChildWindows.Size
        ImStd.ImQsort(window.DC.ChildWindows.Data, count, ChildWindowComparer)
        for i = 1, count do
            local child = window.DC.ChildWindows[i]
            if child.Active then
                AddWindowToSortBuffer(out_sorted_windows, child)
            end
        end
    end
end

local function AddWindowToDrawData(window, layer)
    local g = GImGui
    local viewport = window.Viewport
    g.IO.MetricsRenderWindows = g.IO.MetricsRenderWindows + 1
    if window.DrawList._Splitter._Count > 1 then
        window.DrawList:ChannelsMerge() -- Merge if user forgot to merge back. Also required in Docking branch for ImGuiWindowFlags.DockNodeHost windows.
    end
    ImGui.AddDrawListToDrawDataEx(viewport.DrawDataP, viewport.DrawDataBuilder.Layers[layer], window.DrawList)
    for _, child in window.DC.ChildWindows:iter() do
        if (ImGui.IsWindowActiveAndVisible(child)) then -- Clipped children may have been marked not active
            AddWindowToDrawData(child, layer)
        end
    end
end

--- @param window ImGuiWindow
local function GetWindowDisplayLayer(window)
    return (bit32.band(window.Flags, ImGuiWindowFlags.Tooltip) ~= 0) and 2 or 1
end

-- Layer is locked for the root window, however child windows may use a different viewport (e.g. extruding menu)
--- @param window ImGuiWindow
local function AddRootWindowToDrawData(window)
    AddWindowToDrawData(window, GetWindowDisplayLayer(window))
end

--- @param builder ImDrawDataBuilder
local function FlattenDrawDataIntoSingleLayer(builder)
    local n = builder.Layers[1].Size
    local full_size = n

    for i = 2, #builder.Layers do
        full_size = full_size + builder.Layers[i].Size
    end

    builder.Layers[1]:resize(full_size)

    for layer_n = 2, #builder.Layers do
        local layer = builder.Layers[layer_n]
        if not layer:empty() then
            for i = 1, layer.Size do
                builder.Layers[1].Data[n + i] = layer.Data[i]
            end

            n = n + layer.Size

            layer:resize(0)
        end
    end
end

function ImGui.NewFrame()
    IM_ASSERT(GImGui ~= nil, "No current context. Did you call ImGui::CreateContext() and ImGui::SetCurrentContext() ?")
    local g = GImGui

    g.ConfigFlagsLastFrame = g.ConfigFlagsCurrFrame
    g.ConfigFlagsCurrFrame = g.IO.ConfigFlags

    -- Load settings on first frame, save settings when modified (after a delay)
    ImGui.UpdateSettings()

    g.Time = g.Time + g.IO.DeltaTime

    g.FrameCount = g.FrameCount + 1
    g.TooltipOverrideCount = 0
    g.WindowsActiveCount = 0
    g.MenusIdSubmittedThisFrame:resize(0)

    -- Calculate frame-rate for the user, as a purely luxurious feature
    -- FIXME: are lines below correct and necessary
    g.FramerateSecPerFrameAccum = g.FramerateSecPerFrameAccum + (g.IO.DeltaTime - g.FramerateSecPerFrame[g.FramerateSecPerFrameIdx])
    g.FramerateSecPerFrame[g.FramerateSecPerFrameIdx] = g.IO.DeltaTime
    g.FramerateSecPerFrameIdx = (g.FramerateSecPerFrameIdx + 1) % 60
    g.FramerateSecPerFrameCount = ImMin(g.FramerateSecPerFrameCount + 1, 60)
    if g.FramerateSecPerFrameAccum > 0 then
        g.IO.Framerate = (1.0 / (g.FramerateSecPerFrameAccum / g.FramerateSecPerFrameCount))
    else
        g.IO.Framerate = FLT_MAX
    end

    -- Process input queue (trickle as many events as possible), turn events into writes to IO structure
    ImGui.UpdateInputEvents(g.IO.ConfigInputTrickleEventQueue)

    -- Update viewports (after processing input queue, so io.MouseHoveredViewport is set)
    ImGui.UpdateViewportsNewFrame()

    -- Update texture list (collect destroyed textures, etc.)
    ImGui.UpdateTexturesNewFrame()

    -- Setup current font and draw list shared data
    SetupDrawListSharedData()
    ImGui.UpdateFontsNewFrame()

    g.WithinFrameScope = true

    -- Mark rendering data as invalid to prevent user who may have a handle on it to use it.
    for _, viewport in g.Viewports:iter() do
        viewport.DrawData = nil
        viewport.DrawDataP.Valid = false
    end

    -- Drag and drop keep the source ID alive so even if the source disappear our state is consistent
    if g.DragDropActive and g.DragDropPayload.SourceId == g.ActiveId then
        ImGui.KeepAliveID(g.DragDropPayload.SourceId)
    end

    -- [DEBUG]
    if not g.IO.ConfigDebugHighlightIdConflicts or not g.IO.KeyCtrl then -- Count is locked while holding Ctrl
        g.DebugDrawIdConflictsId = 0
    end
    if g.IO.ConfigDebugHighlightIdConflicts and g.HoveredIdPreviousFrameItemCount > 1 then
        g.DebugDrawIdConflictsId = g.HoveredIdPreviousFrame
    end

    -- Update HoveredId data
    if not g.HoveredIdPreviousFrame then
        g.HoveredIdTimer = 0.0
    end
    if not g.HoveredIdPreviousFrame or (g.HoveredId and g.ActiveId == g.HoveredId) then
        g.HoveredIdNotActiveTimer = 0.0
    end
    if g.HoveredId then
        g.HoveredIdTimer = g.HoveredIdTimer + g.IO.DeltaTime
    end
    if g.HoveredId and g.ActiveId ~= g.HoveredId then
        g.HoveredIdNotActiveTimer = g.HoveredIdNotActiveTimer + g.IO.DeltaTime
    end
    g.HoveredIdPreviousFrame = g.HoveredId
    g.HoveredIdPreviousFrameItemCount = 0
    g.HoveredId = 0
    g.HoveredIdAllowOverlap = false
    g.HoveredIdIsDisabled = false

    -- Clear ActiveID if the item is not alive anymore.
    -- In 1.87, the common most call to KeepAliveID() was moved from GetID() to ItemAdd().
    -- As a result, custom widget using ButtonBehavior() _without_ ItemAdd() need to call KeepAliveID() themselves.
    if (g.ActiveId ~= 0 and g.ActiveIdIsAlive ~= g.ActiveId and g.ActiveIdPreviousFrame == g.ActiveId) then
        IMGUI_DEBUG_LOG_ACTIVEID("NewFrame(): ClearActiveID() 0x%08X because it isn't marked alive anymore!", g.ActiveId)

        ImGui.ClearActiveID()
    end

    -- Update ActiveId data (clear reference to active widget if the widget isn't alive anymore)
    if g.ActiveId then
        g.ActiveIdTimer = g.ActiveIdTimer + g.IO.DeltaTime
    end
    if g.ActiveId and g.ActiveId == g.LastActiveId then
        g.LastActiveIdWasSelected = g.ActiveIdWasSelected
        g.LastActiveIdWasSoleSelected = g.ActiveIdWasSoleSelected
    end

    g.LastActiveIdTimer = g.LastActiveIdTimer + g.IO.DeltaTime
    g.ActiveIdPreviousFrame = g.ActiveId
    g.ActiveIdIsAlive = 0
    g.AnyIdHasBeenEditedThisFrame = false
    g.ActiveIdHasBeenEditedThisFrame = false
    g.ActiveIdIsJustActivated = false
    if g.TempInputId ~= 0 and g.ActiveId ~= g.TempInputId then
        g.TempInputId = 0
    end
    if g.InputTextReactivateId ~= 0 and g.InputTextReactivateId ~= g.DeactivatedItemData.ID then
        g.InputTextReactivateId = 0
    end
    if g.ActiveId == 0 then
        g.ActiveIdUsingNavDirMask = 0x00
        g.ActiveIdUsingAllKeyboardKeys = false
    end
    if g.DeactivatedItemData.ElapseFrame < g.FrameCount then
        g.DeactivatedItemData.ID = 0
    end
    g.DeactivatedItemData.IsAlive = false
    if g.InputTextDeactivatedState.ElapseFrame < g.FrameCount then
        g.InputTextDeactivatedState.ID = 0
    end

    -- Record when we have been stationary as this state is preserved while over same item.
    -- FIXME: The way this is expressed means user cannot alter HoverStationaryDelay during the frame to use varying values.
    -- To allow this we should store HoverItemMaxStationaryTime+ID and perform the >= check in IsItemHovered() function.
    if g.HoverItemDelayId ~= 0 and g.MouseStationaryTimer >= g.Style.HoverStationaryDelay then
        g.HoverItemUnlockedStationaryId = g.HoverItemDelayId
    elseif g.HoverItemDelayId == 0 then
        g.HoverItemUnlockedStationaryId = 0
    end
    if g.HoveredWindow ~= nil and g.MouseStationaryTimer >= g.Style.HoverStationaryDelay then
        g.HoverWindowUnlockedStationaryId = g.HoveredWindow.ID
    elseif g.HoveredWindow == nil then
        g.HoverWindowUnlockedStationaryId = 0
    end

    -- Update hover delay for IsItemHovered() with delays and tooltips
    g.HoverItemDelayIdPreviousFrame = g.HoverItemDelayId
    if g.HoverItemDelayId ~= 0 then
        g.HoverItemDelayTimer = g.HoverItemDelayTimer + g.IO.DeltaTime
        g.HoverItemDelayClearTimer = 0.0
        g.HoverItemDelayId = 0
    elseif g.HoverItemDelayTimer > 0.0 then
        -- This gives a little bit of leeway before clearing the hover timer, allowing mouse to cross gaps
        -- We could expose 0.25f as style.HoverClearDelay but I am not sure of the logic yet, this is particularly subtle.
        g.HoverItemDelayClearTimer = g.HoverItemDelayClearTimer + g.IO.DeltaTime
        if g.HoverItemDelayClearTimer >= ImMax(0.25, g.IO.DeltaTime * 2.0) then  -- ~7 frames at 30 Hz + allow for low framerate
            g.HoverItemDelayTimer = 0.0
            g.HoverItemDelayClearTimer = 0.0  -- May want a decaying timer, in which case need to clamp at max first, based on max of caller last requested timer.
        end
    end

    -- Close popups on focus lost (currently wip/opt-in)
    -- if (g.IO.AppFocusLost)
    --     ClosePopupsExceptModals();

    -- Update keyboard input state
    ImGui.UpdateKeyboardInputs()

    -- IM_ASSERT(g.IO.KeyCtrl == IsKeyDown(ImGuiKey_LeftCtrl) || IsKeyDown(ImGuiKey_RightCtrl));
    -- IM_ASSERT(g.IO.KeyShift == IsKeyDown(ImGuiKey_LeftShift) || IsKeyDown(ImGuiKey_RightShift));
    -- IM_ASSERT(g.IO.KeyAlt == IsKeyDown(ImGuiKey_LeftAlt) || IsKeyDown(ImGuiKey_RightAlt));
    -- IM_ASSERT(g.IO.KeySuper == IsKeyDown(ImGuiKey_LeftSuper) || IsKeyDown(ImGuiKey_RightSuper));

    -- Drag and drop
    g.DragDropAcceptIdPrev = g.DragDropAcceptIdCurr
    g.DragDropAcceptIdCurr = 0
    g.DragDropAcceptFlagsPrev = g.DragDropAcceptFlagsCurr
    g.DragDropAcceptFlagsCurr = ImGuiDragDropFlags.None
    g.DragDropAcceptIdCurrRectSurface = FLT_MAX
    g.DragDropWithinSource = false
    g.DragDropWithinTarget = false
    g.DragDropHoldJustPressedId = 0
    if g.DragDropActive then
        -- Also works when g.ActiveId==0 (aka leftover payload in progress, no active id)
        -- You may disable this externally by hijacking the input route:
        --  'if (GetDragDropPayload() ~= nil) then Shortcut(ImGuiKey.Escape, ImGuiInputFlags.RouteGlobal | ImGuiInputFlags.RouteOverActive) end
        -- but you will not get a return value from Shortcut() due to ActiveIdUsingAllKeyboardKeys logic. You can however poll IsKeyPressed(ImGuiKey.Escape) afterwards.
        local owner_id = (g.ActiveId ~= 0) and g.ActiveId or ImHashStr("##DragDropCancelHandler")
        if ImGui.Shortcut(ImGuiKey.Escape, ImGuiInputFlags.RouteGlobal, owner_id) then
            ImGui.ClearActiveID()
            ImGui.ClearDragDrop()
        end
    end
    g.TooltipPreviousWindow = nil

    -- Update keyboard/gamepad navigation
    ImGui.NavUpdate()

    -- Update mouse input state
    ImGui.UpdateMouseInputs()

    -- Undocking
    -- (needs to be before UpdateMouseMovingWindowNewFrame so the window is already offset and following the mouse on the detaching frame)
    ImGui.DockContextNewFrameUpdateUndocking(g)

    -- Mark all windows as not visible and compact unused memory.
    IM_ASSERT(g.WindowsFocusOrder.Size <= g.Windows.Size)
    local gc_all = g.GcCompactAll or g.IO.ConfigMemoryCompactTimer < 0.0
    local memory_compact_start_time = gc_all and FLT_MAX or (g.Time - g.IO.ConfigMemoryCompactTimer)

    for _, window in g.Windows:iter() do
        window.WasActive = window.Active
        window.Active = false
        window.WriteAccessed = false
        window.BeginCountPreviousFrame = window.BeginCount
        window.BeginCount = 0

        -- Garbage collect transient buffers of recently unused windows
        if (not window.WasActive or gc_all) and not window.MemoryCompacted and window.LastTimeActive < memory_compact_start_time then
            ImGui.GcCompactTransientWindowBuffers(window)
        end
    end

    -- Find hovered window
    -- (needs to be before UpdateMouseMovingWindowNewFrame so we fill g.HoveredWindowUnderMovingWindow on the mouse release frame)
    -- (currently needs to be done after the WasActive=Active loop and FindHoveredWindowEx uses ->Active)
    ImGui.UpdateHoveredWindowAndCaptureFlags(g.IO.MousePos)

    -- Handle user moving window with mouse (at the beginning of the frame to avoid input lag or sheering)
    ImGui.UpdateMouseMovingWindowNewFrame()

    -- Background darkening/whitening
    if ImGui.GetTopMostPopupModal() ~= nil or (g.NavWindowingTarget ~= nil and g.NavWindowingHighlightAlpha > 0.0) then
        g.DimBgRatio = ImMin(g.DimBgRatio + g.IO.DeltaTime * 6.0, 1.0)
    else
        g.DimBgRatio = ImMax(g.DimBgRatio - g.IO.DeltaTime * 10.0, 0.0)
    end

    g.MouseCursor = ImGuiMouseCursor.Arrow
    g.WantCaptureMouseNextFrame = -1
    g.WantCaptureKeyboardNextFrame = -1
    g.WantTextInputNextFrame = -1

    -- Platform IME data: reset for the frame
    ImGuiPlatformImeData_Copy(g.PlatformImeDataPrev, g.PlatformImeData)
    g.PlatformImeData.WantVisible = false
    g.PlatformImeData.WantTextInput = false

    -- Mouse wheel scrolling, scale
    ImGui.UpdateMouseWheel()

    -- Garbage collect transient buffers of recently unused tables
    for i = 1, g.TablesLastTimeActive.Size do
        if g.TablesLastTimeActive.Data[i] >= 0.0 and g.TablesLastTimeActive.Data[i] < memory_compact_start_time then
            ImGui.TableGcCompactTransientBuffers(g.Tables:GetByIndex(i - 1))
        end
    end
    for _, table_temp_data in g.TablesTempData:iter() do
        table_temp_data.ReconcileColumnsRequests:clear() -- Unusual: clear every frame because this is rarely used.
        if table_temp_data.LastTimeActive >= 0.0 and table_temp_data.LastTimeActive < memory_compact_start_time then
            ImGui.TableGcCompactTransientBuffers(table_temp_data)
        end
    end
    if g.GcCompactAll then
        ImGui.GcCompactTransientMiscBuffers()
    end
    g.GcCompactAll = false

    -- Closing the focused window restore focus to the first active root window in descending z-order
    if (g.NavWindow and not g.NavWindow.WasActive) then
        ImGui.FocusTopMostWindowUnderOne(nil, nil, nil, ImGuiFocusRequestFlags.RestoreFocusedChild)
    end

    -- No window should be open at the beginning of the frame.
    -- But in order to allow the user to call NewFrame() multiple times without calling Render(), we are doing an explicit clear.
    g.CurrentWindowStack:resize(0)
    g.BeginPopupStack:resize(0)
    g.ItemFlagsStack:resize(0)
    g.ItemFlagsStack:push_back(ImGuiItemFlags.Default_) -- Default flags
    g.CurrentItemFlags = g.ItemFlagsStack:back()
    g.GroupStack:resize(0)

    -- [DEBUG] ID Stack Tool query
    ImGui.UpdateDebugToolItemPathQuery()

    -- Docking
    ImGui.DockContextNewFrameUpdateDocking(g)

    -- Create implicit/fallback window - which we will only render it if the user has added something to it.
    -- We don't use "Debug" to avoid colliding with user trying to create a "Debug" window with custom flags.
    -- This fallback is particularly important as it prevents ImGui:: calls from crashing.
    g.WithinFrameScopeWithImplicitWindow = true
    ImGui.SetNextWindowSize(ImVec2(400, 400), ImGuiCond.FirstUseEver)
    ImGui.Begin("Debug##Default")
    IM_ASSERT(g.CurrentWindow.IsFallbackWindow == true)

    -- Store stack sizes
    g.ErrorCountCurrentFrame = 0
    g.StackSizesInNewFrame = g.StackSizesInNewFrame or ImGuiErrorRecoveryState()
    ImGui.ErrorRecoveryStoreState(g.StackSizesInNewFrame)
end

-- This is normally called by Render(). You may want to call it directly if you want to avoid calling Render() but the gain will be very minimal.
function ImGui.EndFrame()
    local g = GImGui
    IM_ASSERT(g.Initialized)

    -- Don't process EndFrame() multiple times.
    if g.FrameCountEnded == g.FrameCount then
        return
    end
    IM_ASSERT_USER_ERROR(g.WithinFrameScope, "Forgot to call ImGui::NewFrame()?")

    -- [EXPERIMENTAL] Recover from errors
    if g.IO.ConfigErrorRecovery and g.StackSizesInNewFrame then
        ImGui.ErrorRecoveryTryToRecoverState(g.StackSizesInNewFrame)
    end
    ImGui.ErrorCheckEndFrameFinalizeErrorTooltip()

    -- Notify Platform/OS when our Input Method Editor cursor has moved (e.g. CJK inputs using Microsoft IME)
    local ime_data = g.PlatformImeData
    if g.PlatformIO.Platform_SetImeDataFn ~= nil and not ImGuiPlatformImeData_Compare(ime_data, g.PlatformImeDataPrev) then
        local viewport = ImGui.FindViewportByID(ime_data.ViewportId)
        if viewport == nil then
            viewport = ImGui.GetMainViewport()
        end
        -- IMGUI_DEBUG_LOG_IO("[io] Calling Platform_SetImeDataFn(): WantVisible: %d, InputPos (%.2f,%.2f) for Viewport 0x%08X", ime_data.WantVisible, ime_data.InputPos.x, ime_data.InputPos.y, viewport.ID)
        g.PlatformIO.Platform_SetImeDataFn(g, viewport, ime_data)
    end
    g.WantTextInputNextFrame = ime_data.WantTextInput

    -- Hide implicit/fallback "Debug" window if it hasn't been used
    g.WithinFrameScopeWithImplicitWindow = false
    if (g.CurrentWindow and g.CurrentWindow.IsFallbackWindow and g.CurrentWindow.WriteAccessed == false) then
        g.CurrentWindow.Active = false
    end
    ImGui.End()

    -- Update navigation: Ctrl+Tab, wrap-around requests
    ImGui.NavEndFrame()

    -- Update docking
    ImGui.DockContextEndFrame(g)

    ImGui.SetCurrentViewport(nil, nil)

    -- Drag and Drop: Elapse payload (if delivered, or if source stops being submitted)
    if g.DragDropActive then
        local is_delivered = g.DragDropPayload.Delivery
        local is_elapsed = (g.DragDropSourceFrameCount + 1 < g.FrameCount) and (bit32.band(g.DragDropSourceFlags, ImGuiDragDropFlags.PayloadAutoExpire) ~= 0 or g.DragDropMouseButton == -1 or not ImGui.IsMouseDown(g.DragDropMouseButton))
        if is_delivered or is_elapsed then ImGui.ClearDragDrop() end
    end

    -- Drag and Drop: Fallback for missing source tooltip. This is not ideal but better than nothing.
    -- If you want to handle source item disappearing: instead of submitting your description tooltip
    -- in the BeginDragDropSource() block of the dragged item, you can submit them from a safe single spot
    -- (e.g. end of your item loop, or before EndFrame) by reading payload data.
    -- In the typical case, the contents of drag tooltip should be possible to infer solely from payload data.
    if g.DragDropActive and g.DragDropSourceFrameCount + 1 < g.FrameCount and (bit32.band(g.DragDropSourceFlags, ImGuiDragDropFlags.SourceNoPreviewTooltip) == 0) then
        g.DragDropWithinSource = true
        ImGui.SetTooltip("...")
        g.DragDropWithinSource = false
    end

    -- End frame
    g.WithinFrameScope = false
    g.FrameCountEnded = g.FrameCount
    ImGui.UpdateFontsEndFrame()

    -- Initiate moving window + handle left-click and right-click focus
    ImGui.UpdateMouseMovingWindowEndFrame()

    -- Update user-facing viewport list (g.Viewports -> g.PlatformIO.Viewports after filtering out some)
    ImGui.UpdateViewportsEndFrame()

    -- Sort the window list so that all child windows are after their parent
    -- We cannot do that on FocusWindow() because children may not exist yet
    g.WindowsTempSortBuffer:resize(0)
    g.WindowsTempSortBuffer:reserve(g.Windows.Size)
    for _, window in g.Windows:iter() do
        repeat
        if window.Active and bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0 then -- if a child is active its parent will add it
            break
        end

        AddWindowToSortBuffer(g.WindowsTempSortBuffer, window)

        until true
    end

    -- This usually assert if there is a mismatch between the ImGuiWindowFlags.ChildWindow / ParentWindow values and DC.ChildWindows[] in parents, aka we've done something wrong.
    IM_ASSERT(g.Windows.Size == g.WindowsTempSortBuffer.Size)
    g.Windows:swap(g.WindowsTempSortBuffer)
    g.IO.MetricsActiveWindows = g.WindowsActiveCount

    ImGui.UpdateTexturesEndFrame()

    -- Unlock font atlas
    for _, atlas in g.FontAtlases:iter() do
        atlas.Locked = false
    end

    -- Clear Input data for next frame
    ImVec2_Copy(g.IO.MousePosPrev, g.IO.MousePos)
    g.IO.AppFocusLost = false
    g.IO.MouseWheel = 0.0
    g.IO.MouseWheelH = 0.0
    g.IO.InputQueueCharacters:resize(0)
end

-- TODO:
-- Prepare the data for rendering so you can call GetDrawData()
-- (As with anything within the ImGui:: namespace this doesn't touch your GPU or graphics API at all:
-- it is the role of the ImGui_ImplXXXX_RenderDrawData() function provided by the renderer backend)
function ImGui.Render()
    local g = GImGui
    IM_ASSERT(g.Initialized)

    if g.FrameCountEnded ~= g.FrameCount then
        ImGui.EndFrame()
    end
    if g.FrameCountRendered == g.FrameCount then return end
    g.FrameCountRendered = g.FrameCount

    g.IO.MetricsRenderWindows = 0

    -- Add background ImDrawList (for each active viewport)
    for _, viewport in g.Viewports:iter() do
        InitViewportDrawData(viewport)
        if viewport.BgFgDrawLists[1] ~= nil and viewport.BgFgDrawListsLastTimeActive[1] == g.Time then
            ImGui.AddDrawListToDrawDataEx(viewport.DrawDataP, viewport.DrawDataBuilder.Layers[1], ImGui.GetBackgroundDrawList(viewport))
        end
    end

    -- Draw modal/window whitening backgrounds
    ImGui.RenderDimmedBackgrounds()

    -- Add ImDrawList to render
    local windows_to_render_top_most = {nil, nil}
    windows_to_render_top_most[1] = (g.NavWindowingTarget and (bit32.band(g.NavWindowingTarget.Flags, ImGuiWindowFlags.NoBringToFrontOnFocus) == 0)) and g.NavWindowingTarget.RootWindowDockTree or nil
    windows_to_render_top_most[2] = g.NavWindowingTarget and g.NavWindowingListWindow or nil
    for _, window in g.Windows:iter() do
        if ImGui.IsWindowActiveAndVisible(window) and (bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) == 0) and window ~= windows_to_render_top_most[1] and window ~= windows_to_render_top_most[2] then
            AddRootWindowToDrawData(window)
        end
    end
    for n = 1, 2 do
        if windows_to_render_top_most[n] and ImGui.IsWindowActiveAndVisible(windows_to_render_top_most[n]) then  -- NavWindowingTarget is always temporarily displayed as the top-most window
            AddRootWindowToDrawData(windows_to_render_top_most[n])
        end
    end

    -- Draw software mouse cursor if requested by io.MouseDrawCursor flag
    if g.IO.MouseDrawCursor and g.MouseCursor ~= ImGuiMouseCursor.None then
        ImGui.RenderMouseCursor(g.IO.MousePos, g.Style.MouseCursorScale, g.MouseCursor, IM_COL32_WHITE, IM_COL32_BLACK, IM_COL32(0, 0, 0, 48))
    end

    -- Setup ImDrawData structures for end-user
    g.IO.MetricsRenderVertices = 0
    g.IO.MetricsRenderIndices = 0
    for _, viewport in g.Viewports:iter() do
        FlattenDrawDataIntoSingleLayer(viewport.DrawDataBuilder)

        -- Add foreground ImDrawList (for each active viewport)
        if viewport.BgFgDrawLists[2] ~= nil and viewport.BgFgDrawListsLastTimeActive[2] == g.Time then
            ImGui.AddDrawListToDrawDataEx(viewport.DrawDataP, viewport.DrawDataBuilder.Layers[1], ImGui.GetForegroundDrawList(viewport))
        end

        -- We call _PopUnusedDrawCmd() last thing, as RenderDimmedBackgrounds() rely on a valid command being there (especially in docking branch).
        local draw_data = viewport.DrawDataP
        for _, draw_list in draw_data.CmdLists:iter() do
            draw_list:_PopUnusedDrawCmd()
        end

        g.IO.MetricsRenderVertices = g.IO.MetricsRenderVertices + draw_data.TotalVtxCount
        g.IO.MetricsRenderIndices = g.IO.MetricsRenderIndices + draw_data.TotalIdxCount
    end
end

-- Calculate text size. Text can be multi-line. Optionally ignore text after a ## marker.
-- CalcTextSize("") should return ImVec2(0.0, g.FontSize)
--- @param text                         ImString
--- @param text_end?                    int    # Exclusive upper bound
--- @param hide_text_after_double_hash? bool
--- @param wrap_width?                  float
--- @return ImVec2

function ImGui.CalcTextSize(text, text_end, hide_text_after_double_hash, wrap_width)
    return ImGui.CalcTextSizeEx(text, 1, text_end, hide_text_after_double_hash, wrap_width)
end

--- @param text                         ImString
--- @param text_begin                   int
--- @param text_end?                    int    # Exclusive upper bound
--- @param hide_text_after_double_hash? bool
--- @param wrap_width?                  float
--- @return ImVec2

function ImGui.CalcTextSizeEx(text, text_begin, text_end, hide_text_after_double_hash, wrap_width)
    if hide_text_after_double_hash == nil then hide_text_after_double_hash = false end
    if wrap_width                  == nil then wrap_width                  = -1.0  end

    local g = GImGui

    local text_display_end
    if hide_text_after_double_hash then
        text_display_end = ImGui.FindRenderedTextEnd(text, text_end) -- Hide anything after a '##' string
    else
        text_display_end = text_end
    end

    local font = g.Font
    local font_size = g.FontSize
    if text == "" or (text_end and text_end <= text_begin) then
        return ImVec2(0.0, font_size)
    end
    local text_size = ImFontCalcTextSizeEx(font, font_size, FLT_MAX, wrap_width, text, text_begin, text_display_end, text_display_end, nil, ImDrawTextFlags.None) -- [Luau] inline font:CalcTextSizeA()

    -- Round
    -- (see 7b0bf230, 4622fa4b6, #791 for details about this.)
    -- FIXME: Add a way to disable this.
    text_size.x = math.ceil(text_size.x) -- [Luau] == ImCeilFast() for all finite values, builtin

    return text_size
end

-- Pass this to your backend rendering function! Valid after Render() and until the next call to NewFrame()
function ImGui.GetDrawData()
    local g = GImGui
    local viewport = g.Viewports[1]
    return viewport.DrawDataP.Valid and viewport.DrawDataP or nil
end

function ImGui.GetTime()
    return GImGui.Time
end

-- This function is merely here to free heap allocations.
function ImGui.Shutdown()
    local g = GImGui
    IM_ASSERT_USER_ERROR(g.IO.BackendPlatformUserData == nil, "Forgot to shutdown Platform backend?")
    IM_ASSERT_USER_ERROR(g.IO.BackendRendererUserData == nil, "Forgot to shutdown Renderer backend?")
    for _, viewport in g.Viewports:iter() do
        -- IM_UNUSED(viewport)
        IM_ASSERT_USER_ERROR(viewport.RendererUserData == nil and viewport.PlatformUserData == nil and viewport.PlatformHandle == nil, "Backend or app forgot to call DestroyPlatformWindows()?")
    end

    -- The fonts atlas can be used prior to calling NewFrame(), so we clear it even if g.Initialized is FALSE (which would happen if we never called NewFrame)
    for _, atlas in g.FontAtlases:iter() do
        ImGui.UnregisterFontAtlas(atlas)
        if atlas.OwnerContext == g then
            IM_ASSERT(atlas.RefCount == 0, "Destroying context owning a ImFontAtlas which is still used elsewhere!")
            if atlas.RefCount == 0 then
                atlas.Locked = false
            end
        end
    end
    g.DrawListSharedData.TempBuffer:clear()

    -- Shutdown extensions
    ImGui.DockContextShutdown(g)

    -- Cleanup of other data are conditional on actually having initialized Dear ImGui.
    if not g.Initialized then
        return
    end
    -- TODO:

    -- Clear everything else
    g.MenusIdSubmittedThisFrame:clear()
end

-- A conformant backend should return nil on failure (e.g. clipboard data is not text).
--- @return string?
function ImGui.GetClipboardText()
    local g = GImGui
    return g.PlatformIO.Platform_GetClipboardTextFn and g.PlatformIO.Platform_GetClipboardTextFn(g) or nil
end

--- @param text string
function ImGui.SetClipboardText(text)
    local g = GImGui
    if g.PlatformIO.Platform_SetClipboardTextFn ~= nil then
        g.PlatformIO.Platform_SetClipboardTextFn(g, text)
    end
end

function ImGui.GetIO() return GImGui.IO end

--- @return ImGuiPlatformIO
function ImGui.GetPlatformIO()
    IM_ASSERT(GImGui ~= nil, "No current context. Did you call ImGui.CreateContext() and ImGui.SetCurrentContext()?")
    return GImGui.PlatformIO
end

-- Get desired mouse cursor shape.
-- Important: this is meant to be used by a platform backend, it is reset in ImGui.NewFrame(),
-- updated during the frame, and locked in EndFrame()/Render().
-- If you use software rendering by setting io.MouseDrawCursor then Dear ImGui will render those for you
function ImGui.GetMouseCursor()
    local g = GImGui
    return g.MouseCursor
end

-- We intentionally accept values of ImGuiMouseCursor that are outside our bounds, in case users needs to hack-in a custom cursor value.
-- Custom cursors may be handled by custom backends. If you are using a standard backend and want to hack in a custom cursor, you may
-- handle it before the backend _NewFrame() call and temporarily set ImGuiConfigFlags.NoMouseCursorChange during the backend _NewFrame() call.
--- @param cursor_type ImGuiMouseCursor
function ImGui.SetMouseCursor(cursor_type)
    local g = GImGui
    g.MouseCursor = cursor_type
end

-------------------------------------------------------------------------------
-- [SECTION] MISC HELPERS/UTILITIES (Color functions)
-- Note: The Convert functions are early design which are not consistent with other API.
-------------------------------------------------------------------------------

--- @param col_a ImU32
--- @param col_b ImU32
--- @return ImU32
function ImStd.ImAlphaBlendColors(col_a, col_b)
    local t = bit32.band(bit32.rshift(col_b, IM_COL32_A_SHIFT), 0xFF) / 255.0
    local r = ImLerp(bit32.band(bit32.rshift(col_a, IM_COL32_R_SHIFT), 0xFF), bit32.band(bit32.rshift(col_b, IM_COL32_R_SHIFT), 0xFF), t)
    local g = ImLerp(bit32.band(bit32.rshift(col_a, IM_COL32_G_SHIFT), 0xFF), bit32.band(bit32.rshift(col_b, IM_COL32_G_SHIFT), 0xFF), t)
    local b = ImLerp(bit32.band(bit32.rshift(col_a, IM_COL32_B_SHIFT), 0xFF), bit32.band(bit32.rshift(col_b, IM_COL32_B_SHIFT), 0xFF), t)
    return IM_COL32(r, g, b, 0xFF)
end

--- @param in_col  ImU32
--- @param out_col ImVec4?
--- @return ImVec4?
function ImGui.ColorConvertU32ToFloat4(in_col, out_col)
    local s = 1.0 / 255.0
    local r = bit32.band(bit32.rshift(in_col, IM_COL32_R_SHIFT), 0xFF) * s
    local g = bit32.band(bit32.rshift(in_col, IM_COL32_G_SHIFT), 0xFF) * s
    local b = bit32.band(bit32.rshift(in_col, IM_COL32_B_SHIFT), 0xFF) * s
    local a = bit32.band(bit32.rshift(in_col, IM_COL32_A_SHIFT), 0xFF) * s

    if out_col then
        out_col[1] = r; out_col[2] = g; out_col[3] = b; out_col[4] = a
    else
        return ImVec4(r, g, b, a)
    end
end

--- @param in_col ImVec4
--- @return ImU32
local function F32ToU8Sat(v) if v < 0.0 then v = 0.0 elseif v > 1.0 then v = 1.0 end return math.floor(v * 255.0 + 0.5) end


function ImGui.ColorConvertFloat4ToU32(in_col)
    return bit32.bor(F32ToU8Sat(in_col.x), bit32.lshift(F32ToU8Sat(in_col.y), 8), bit32.lshift(F32ToU8Sat(in_col.z), 16), bit32.lshift(F32ToU8Sat(in_col.w), 24))
end

-- Convert rgb floats ([0-1],[0-1],[0-1]) to hsv floats ([0-1],[0-1],[0-1]), from Foley & van Dam p592
-- Optimized http://lolengine.net/blog/2013/01/13/fast-rgb-to-hsv
--- @param r float
--- @param g float
--- @param b float
--- @return float, float, float

function ImGui.ColorConvertRGBtoHSV(r, g, b)
    local K = 0.0
    if g < b then
        g, b = b, g
        K = -1.0
    end
    if r < g then
        r, g = g, r
        K = -2.0 / 6.0 - K
    end

    local chroma = r - (g < b and g or b)
    local out_h = ImFabs(K + (g - b) / (6.0 * chroma + 1e-20))
    local out_s = chroma / (r + 1e-20)
    local out_v = r
    return out_h, out_s, out_v
end

-- Convert hsv floats ([0-1],[0-1],[0-1]) to rgb floats ([0-1],[0-1],[0-1]), from Foley & van Dam p593
-- also http://en.wikipedia.org/wiki/HSL_and_HSV
--- @param h float
--- @param s float
--- @param v float
--- @return float, float, float

function ImGui.ColorConvertHSVtoRGB(h, s, v)
    if s == 0.0 then
        -- gray
        return v, v, v
    end

    h = ImFmod(h, 1.0) / (60.0 / 360.0)
    local i = math.floor(h)
    local f = h - i
    local p = v * (1.0 - s)
    local q = v * (1.0 - s * f)
    local t = v * (1.0 - s * (1.0 - f))

    if i == 0 then
        return v, t, p
    elseif i == 1 then
        return q, v, p
    elseif i == 2 then
        return p, v, t
    elseif i == 3 then
        return p, q, v
    elseif i == 4 then
        return t, p, v
    else -- i == 5 or default
        return v, p, q
    end
end

-- Generic helper, equivalent to old ImGui.CalcListClipping() but stateless
--- @param clip_rect    ImRect
--- @param pos          ImVec2
--- @param items_height float
function ImGui.CalcClipRectVisibleItemsY(clip_rect, pos, items_height)
    local visible_start = ImMax(ImTrunc((clip_rect.Min.y - pos.y) / items_height), 0)
    local visible_end = ImMax(ImTrunc(ImCeil((clip_rect.Max.y - pos.y) / items_height)), visible_start)
    return visible_start + 1, visible_end + 1
end

-------------------------------------------------------------------------------
-- [SECTION] STYLING
-------------------------------------------------------------------------------

function ImGui.GetStyle()
    IM_ASSERT(GImGui ~= nil, "No current context. Did you call ImGui::CreateContext() and ImGui::SetCurrentContext() ?")
    return GImGui.Style
end

do

local c = ImVec4()

--- @param col         ImGuiCol|ImVec4|ImU32
--- @param alpha_mul?  float
--- @param col_is_u32? bool                  # must be truthy if `col` is `ImU32`
--- @return ImU32

function ImGui.GetColorU32(col, alpha_mul, col_is_u32)
    if alpha_mul == nil then alpha_mul = 1.0 end

    local style = GImGui.Style

    if not col_is_u32 then
        --- @cast col ImVec4|ImGuiCol
        local w
        if type(col) == "number" then
            col = style.Colors[col]
            w = col.w * style.Alpha * alpha_mul
        else --- @cast col ImVec4
            w = col.w * style.Alpha
        end
        -- [Luau] inline F32ToU8Sat() x4
        local x, y, z = col.x, col.y, col.z
        if x < 0.0 then x = 0.0 elseif x > 1.0 then x = 1.0 end
        if y < 0.0 then y = 0.0 elseif y > 1.0 then y = 1.0 end
        if z < 0.0 then z = 0.0 elseif z > 1.0 then z = 1.0 end
        if w < 0.0 then w = 0.0 elseif w > 1.0 then w = 1.0 end
        return bit32.bor(math.floor(x * 255.0 + 0.5), bit32.lshift(math.floor(y * 255.0 + 0.5), 8), bit32.lshift(math.floor(z * 255.0 + 0.5), 16), bit32.lshift(math.floor(w * 255.0 + 0.5), 24))
    else
        --- @cast col ImU32
        alpha_mul = alpha_mul * style.Alpha
        if alpha_mul >= 1.0 then
            return col
        end
        local a = bit32.rshift(bit32.band(col, IM_COL32_A_MASK), IM_COL32_A_SHIFT)
        a = math.floor(a * alpha_mul) -- We don't need to clamp 0..255 because alpha is in 0..1 range.
        return bit32.bor(bit32.band(col, bit32.bnot(IM_COL32_A_MASK)), bit32.lshift(a, IM_COL32_A_SHIFT))
    end
end

end

-- FIXME: This may incur a round-trip (if the end user got their data from a float4) but eventually we aim to store the in-flight colors as ImU32
--- @param idx ImGuiCol
--- @param col ImU32|ImVec4
function ImGui.PushStyleColor(idx, col)
    local g = GImGui
    local backup = ImGuiColorMod(idx, g.Style.Colors[idx])
    -- [Luau] inline g.ColorStack:push_back(backup)
    local stack = g.ColorStack
    local n = stack.Size + 1
    if n > stack.Capacity then stack:push_back(backup) else stack.Data[n] = backup; stack.Size = n end
    if g.DebugFlashStyleColorIdx ~= idx then
        if type(col) == "number" then
            ImGui.ColorConvertU32ToFloat4(col, g.Style.Colors[idx])
        else --- @cast col ImVec4
            ImVec4_Copy(g.Style.Colors[idx], col)
        end
    end
end

--- @param count? int
function ImGui.PopStyleColor(count)
    if count == nil then count = 1 end

    local g = GImGui
    if g.ColorStack.Size < count then
        IM_ASSERT_USER_ERROR(false, "Calling PopStyleColor() too many times!")
        count = g.ColorStack.Size
    end

    local stack = g.ColorStack
    while count > 0 do
        local backup = stack.Data[stack.Size] -- [Luau] inline back()/pop_back()
        ImVec4_Copy(g.Style.Colors[backup.Col], backup.BackupValue)
        stack.Size = stack.Size - 1
        count = count - 1
    end
end

local GStyleVarsInfo = {
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "Alpha"), -- ImGuiStyleVar.Alpha
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "DisabledAlpha"), -- ImGuiStyleVar.DisabledAlpha
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "WindowPadding"), -- ImGuiStyleVar.WindowPadding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "WindowRounding"), -- ImGuiStyleVar.WindowRounding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "WindowBorderSize"), -- ImGuiStyleVar.WindowBorderSize
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "WindowMinSize"), -- ImGuiStyleVar.WindowMinSize
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "WindowTitleAlign"), -- ImGuiStyleVar.WindowTitleAlign
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "ChildRounding"), -- ImGuiStyleVar.ChildRounding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "ChildBorderSize"), -- ImGuiStyleVar.ChildBorderSize
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "PopupRounding"), -- ImGuiStyleVar.PopupRounding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "PopupBorderSize"), -- ImGuiStyleVar.PopupBorderSize
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "FramePadding"), -- ImGuiStyleVar.FramePadding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "FrameRounding"), -- ImGuiStyleVar.FrameRounding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "FrameBorderSize"), -- ImGuiStyleVar.FrameBorderSize
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "ItemSpacing"), -- ImGuiStyleVar.ItemSpacing
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "ItemInnerSpacing"), -- ImGuiStyleVar.ItemInnerSpacing
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "IndentSpacing"), -- ImGuiStyleVar.IndentSpacing
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "CellPadding"), -- ImGuiStyleVar.CellPadding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "ScrollbarSize"), -- ImGuiStyleVar.ScrollbarSize
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "ScrollbarRounding"), -- ImGuiStyleVar.ScrollbarRounding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "ScrollbarPadding"), -- ImGuiStyleVar.ScrollbarPadding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "GrabMinSize"), -- ImGuiStyleVar.GrabMinSize
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "GrabRounding"), -- ImGuiStyleVar.GrabRounding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "ImageRounding"), -- ImGuiStyleVar.ImageRounding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "ImageBorderSize"), -- ImGuiStyleVar.ImageBorderSize
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "TabRounding"), -- ImGuiStyleVar.TabRounding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "TabBorderSize"), -- ImGuiStyleVar.TabBorderSize
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "TabMinWidthBase"), -- ImGuiStyleVar.TabMinWidthBase
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "TabMinWidthShrink"), -- ImGuiStyleVar.TabMinWidthShrink
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "TabBarBorderSize"), -- ImGuiStyleVar.TabBarBorderSize
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "TabBarOverlineSize"), -- ImGuiStyleVar.TabBarOverlineSize
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "TableAngledHeadersAngle"), -- ImGuiStyleVar.TableAngledHeadersAngle
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "TableAngledHeadersTextAlign"), -- ImGuiStyleVar.TableAngledHeadersTextAlign
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "TreeLinesSize"), -- ImGuiStyleVar.TreeLinesSize
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "TreeLinesRounding"), -- ImGuiStyleVar.TreeLinesRounding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "MenuItemRounding"), -- ImGuiStyleVar.MenuItemRounding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "SelectableRounding"), -- ImGuiStyleVar.SelectableRounding
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "DragDropTargetRounding"), -- ImGuiStyleVar.DragDropTargetRounding
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "ButtonTextAlign"), -- ImGuiStyleVar.ButtonTextAlign
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "SelectableTextAlign"), -- ImGuiStyleVar.SelectableTextAlign
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "SeparatorSize"), -- ImGuiStyleVar.SeparatorSize
    ImGuiStyleVarInfo(1, ImGuiDataType.Float, "SeparatorTextBorderSize"), -- ImGuiStyleVar.SeparatorTextBorderSize
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "SeparatorTextAlign"), -- ImGuiStyleVar.SeparatorTextAlign
    ImGuiStyleVarInfo(2, ImGuiDataType.Float, "SeparatorTextPadding") -- ImGuiStyleVar.SeparatorTextPadding
}

--- @param idx ImGuiStyleVar
--- @return ImGuiStyleVarInfo
function ImGui.GetStyleVarInfo(idx)
    IM_ASSERT(idx >= 0 and idx < ImGuiStyleVar.COUNT)
    -- IM_STATIC_ASSERT(IM_COUNTOF(GStyleVarsInfo) == ImGuiStyleVar.COUNT)
    return GStyleVarsInfo[idx + 1]
end

--- @param idx ImGuiStyleVar
--- @param val float|ImVec2
function ImGui.PushStyleVar(idx, val)
    local g = GImGui
    local var_info = ImGui.GetStyleVarInfo(idx)
    if type(val) == "number" then
        IM_ASSERT_USER_ERROR_RET(var_info.DataType == ImGuiDataType.Float and var_info.Count == 1, "Calling PushStyleVar() with wrong type!")
    else -- ImVec2
        IM_ASSERT_USER_ERROR_RET(var_info.DataType == ImGuiDataType.Float and var_info.Count == 2, "Calling PushStyleVar() with wrong type!")
    end
    local var = g.Style[var_info.Key]
    g.StyleVarStack:push_back(ImGuiStyleMod(idx, var))
    if type(val) == "number" then
        g.Style[var_info.Key] = val
    else -- copy into the style's own ImVec2: storing the caller's vector would alias it into the style forever
        var.x = val.x; var.y = val.y
    end
end

--- @param idx   ImGuiStyleVar
--- @param val_x float
function ImGui.PushStyleVarX(idx, val_x)
    local g = GImGui
    local var_info = ImGui.GetStyleVarInfo(idx)
    IM_ASSERT_USER_ERROR_RET(var_info.DataType == ImGuiDataType.Float and var_info.Count == 2, "Calling PushStyleVarX() with wrong type!")
    local pvar = g.Style[var_info.Key]
    g.StyleVarStack:push_back(ImGuiStyleMod(idx, pvar))
    pvar.x = val_x
end

--- @param idx   ImGuiStyleVar
--- @param val_y float
function ImGui.PushStyleVarY(idx, val_y)
    local g = GImGui
    local var_info = ImGui.GetStyleVarInfo(idx)
    IM_ASSERT_USER_ERROR_RET(var_info.DataType == ImGuiDataType.Float and var_info.Count == 2, "Calling PushStyleVarY() with wrong type!")
    local pvar = g.Style[var_info.Key]
    g.StyleVarStack:push_back(ImGuiStyleMod(idx, pvar))
    pvar.y = val_y
end

--- @param count? int
function ImGui.PopStyleVar(count)
    if count == nil then count = 1 end

    local g = GImGui
    if g.StyleVarStack.Size < count then
        IM_ASSERT_USER_ERROR(0, "Calling PopStyleVar() too many times!")
        count = g.StyleVarStack.Size
    end
    local stack = g.StyleVarStack
    while count > 0 do
        local backup = stack.Data[stack.Size] -- [Luau] inline back()/pop_back()
        local var_info = ImGui.GetStyleVarInfo(backup.VarIdx)
        local data = g.Style[var_info.Key]
        if (var_info.DataType == ImGuiDataType.Float and var_info.Count == 1) then
            g.Style[var_info.Key] = backup.BackupVal[1]
        elseif (var_info.DataType == ImGuiDataType.Float and var_info.Count == 2) then
            data.x = backup.BackupVal[1]; data.y = backup.BackupVal[2]
        end
        stack.Size = stack.Size - 1
        count = count - 1
    end
end

-- ATTENTION THIS IS IN LEGACY LOCAL SPACE.
--- @param wrap_local_pos_x float
function ImGui.PushTextWrapPos(wrap_local_pos_x)
    local g = GImGui
    local window = g.CurrentWindow
    -- [Luau] inline window.DC.TextWrapPosStack:push_back(window.DC.TextWrapPos)
    local dc = window.DC
    local stack = dc.TextWrapPosStack
    local n = stack.Size + 1
    if n > stack.Capacity then stack:push_back(dc.TextWrapPos) else stack.Data[n] = dc.TextWrapPos; stack.Size = n end
    dc.TextWrapPos = wrap_local_pos_x
end

function ImGui.PopTextWrapPos()
    local g = GImGui
    local window = g.CurrentWindow
    local stack = window.DC.TextWrapPosStack
    IM_ASSERT_USER_ERROR_RET(stack.Size > 0, "Calling PopTextWrapPos() too many times!")
    window.DC.TextWrapPos = stack.Data[stack.Size] -- [Luau] inline back()/pop_back()
    stack.Size = stack.Size - 1
end

--- @param window          ImGuiWindow
--- @param popup_hierarchy bool
--- @param dock_hierarchy  bool
local function GetCombinedRootWindow(window, popup_hierarchy, dock_hierarchy)
    local last_window = nil
    while last_window ~= window do
        last_window = window
        window = window.RootWindow
        if popup_hierarchy then
            window = window.RootWindowPopupTree
        end
        if dock_hierarchy then
            window = window.RootWindowDockTree
        end
    end
    return window
end

--- @param window           ImGuiWindow
--- @param potential_parent ImGuiWindow
--- @param popup_hierarchy  bool
--- @param dock_hierarchy   bool
function ImGui.IsWindowChildOf(window, potential_parent, popup_hierarchy, dock_hierarchy)
    local window_root = GetCombinedRootWindow(window, popup_hierarchy, dock_hierarchy)
    if window_root == potential_parent then
        return true
    end

    while window ~= nil do
        if window == potential_parent then
            return true
        end
        if window == window_root then -- end of chain
            return false
        end
        window = window.ParentWindow
    end

    return false
end

--- @param window ImGuiWindow
function ImGui.IsWindowInBeginStack(window)
    local g = GImGui
    for n = g.CurrentWindowStack.Size, 1, -1 do
        if g.CurrentWindowStack.Data[n].Window == window then
            return true
        end
    end
    return false
end

--- @param window           ImGuiWindow
--- @param potential_parent ImGuiWindow
function ImGui.IsWindowWithinBeginStackOf(window, potential_parent)
    if window.RootWindow == potential_parent then
        return true
    end

    while window ~= nil do
        if window == potential_parent then
            return true
        end
        window = window.ParentWindowInBeginStack
    end

    return false
end

--- @param potential_above ImGuiWindow
--- @param potential_below ImGuiWindow
--- @return bool
function ImGui.IsWindowAbove(potential_above, potential_below)
    local g = GImGui

    -- It would be saner to ensure that display layer is always reflected in the g.Windows[] order, which would likely requires altering all manipulations of that array
    local display_layer_delta = GetWindowDisplayLayer(potential_above) - GetWindowDisplayLayer(potential_below)
    if display_layer_delta ~= 0 then
        return display_layer_delta > 0
    end

    for i = g.Windows.Size, 1, -1 do
        local candidate_window = g.Windows.Data[i]
        if candidate_window == potential_above then
            return true
        end
        if candidate_window == potential_below then
            return false
        end
    end
    return false
end

-- Is current window hovered and hoverable (e.g. not blocked by a popup/modal)? See ImGuiHoveredFlags for options.
-- IMPORTANT: If you are trying to check whether your mouse should be dispatched to Dear ImGui or to your underlying app,
-- you should not use this function! Use the 'io.WantCaptureMouse' boolean for that!
-- Refer to FAQ entry "How can I tell whether to dispatch mouse/keyboard to Dear ImGui or my application?" for details.
--- @param flags? ImGuiHoveredFlags
function ImGui.IsWindowHovered(flags)
    if flags == nil then flags = 0 end
    local g = GImGui
    IM_ASSERT_USER_ERROR(bit32.band(flags, bit32.bnot(ImGuiHoveredFlags.AllowedMaskForIsWindowHovered)) == 0, "Invalid flags for IsWindowHovered()!")

    local ref_window = g.HoveredWindow
    local cur_window = g.CurrentWindow
    if ref_window == nil then
        return false
    end

    if bit32.band(flags, ImGuiHoveredFlags.AnyWindow) == 0 then
        IM_ASSERT(cur_window) -- Not inside a Begin()/End()
        local popup_hierarchy = bit32.band(flags, ImGuiHoveredFlags.NoPopupHierarchy) == 0
        local dock_hierarchy = bit32.band(flags, ImGuiHoveredFlags.DockHierarchy) ~= 0
        if bit32.band(flags, ImGuiHoveredFlags.RootWindow) ~= 0 then
            cur_window = GetCombinedRootWindow(cur_window, popup_hierarchy, dock_hierarchy)
        end

        local result
        if bit32.band(flags, ImGuiHoveredFlags.ChildWindows) ~= 0 then
            result = ImGui.IsWindowChildOf(ref_window, cur_window, popup_hierarchy, dock_hierarchy)
        else
            result = (ref_window == cur_window)
        end
        if not result then
            return false
        end
    end

    if not ImGui.IsWindowContentHoverable(ref_window, flags) then
        return false
    end
    if bit32.band(flags, ImGuiHoveredFlags.AllowWhenBlockedByActiveItem) == 0 then
        if g.ActiveId ~= 0 and not g.ActiveIdAllowOverlap and g.ActiveId ~= ref_window.MoveId then
            return false
        end
    end

    -- When changing hovered window we requires a bit of stationary delay before activating hover timer.
    -- FIXME: We don't support delay other than stationary one for now, other delay would need a way
    -- to fulfill the possibility that multiple IsWindowHovered() with varying flag could return true
    -- for different windows of the hierarchy. Possibly need a Hash(Current+Flags) ==> (Timer) cache.
    -- We can implement this for _Stationary because the data is linked to HoveredWindow rather than CurrentWindow.
    if bit32.band(flags, ImGuiHoveredFlags.ForTooltip) ~= 0 then
        flags = ApplyHoverFlagsForTooltip(flags, g.Style.HoverFlagsForTooltipMouse)
    end
    if bit32.band(flags, ImGuiHoveredFlags.Stationary) ~= 0 and g.HoverWindowUnlockedStationaryId ~= ref_window.ID then
        return false
    end

    return true
end

-- Similar to IsWindowHovered()
--- @param flags? ImGuiFocusedFlags
function ImGui.IsWindowFocused(flags)
    if flags == nil then flags = 0 end
    local g = GImGui
    local ref_window = g.NavWindow
    local cur_window = g.CurrentWindow

    if ref_window == nil then
        return false
    end
    if bit32.band(flags, ImGuiFocusedFlags.AnyWindow) ~= 0 then
        return true
    end

    IM_ASSERT(cur_window) -- Not inside a Begin()/End()
    local popup_hierarchy = bit32.band(flags, ImGuiFocusedFlags.NoPopupHierarchy) == 0
    local dock_hierarchy = bit32.band(flags, ImGuiFocusedFlags.DockHierarchy) ~= 0
    if bit32.band(flags, ImGuiFocusedFlags.RootWindow) ~= 0 then
        cur_window = GetCombinedRootWindow(cur_window, popup_hierarchy, dock_hierarchy)
    end

    if bit32.band(flags, ImGuiFocusedFlags.ChildWindows) ~= 0 then
        return ImGui.IsWindowChildOf(ref_window, cur_window, popup_hierarchy, dock_hierarchy)
    else
        return ref_window == cur_window
    end
end

--- @param window ImGuiWindow
--- @param scale  float
local function ScaleWindow(window, scale)
    local origin = window.Viewport.Pos
    ImVec2_Copy(window.Pos, ImFloor((window.Pos - origin) * scale + origin))
    ImVec2_Copy(window.Size, ImTrunc(window.Size * scale))
    ImVec2_Copy(window.SizeFull, ImTrunc(window.SizeFull * scale))
    ImVec2_Copy(window.ContentSize, ImTrunc(window.ContentSize * scale))
end

-- Scale all windows (position, size). Use when e.g. changing DPI. (This is a lossy operation!)
--- @param viewport ImGuiViewportP
--- @param scale    float
function ImGui.ScaleWindowsInViewport(viewport, scale)
    local g = GImGui
    -- IMGUI_DEBUG_LOG_VIEWPORT("[viewport] ScaleWindowsInViewport 0x%08X\n", viewport.ID)

    if viewport.Window then
        ScaleWindow(viewport.Window, scale)
    else
        for _, window in g.Windows:iter() do
            if window.Viewport == viewport then
                ScaleWindow(window, scale)
            end
        end
    end
end

-------------------------------------------------------------------------------
-- [SECTION] SCROLLING
-------------------------------------------------------------------------------

-- Helper to snap on edges when aiming at an item very close to the edge,
-- So the difference between WindowPadding and ItemSpacing will be in the visible area after scrolling.
-- When we refactor the scrolling API this may be configurable with a flag?
-- Note that the effect for this won't be visible on X axis with default Style settings as WindowPadding.x == ItemSpacing.x by default.
--- @param target         float
--- @param snap_min       float
--- @param snap_max       float
--- @param snap_threshold float
--- @param center_ratio   float
local function CalcScrollEdgeSnap(target, snap_min, snap_max, snap_threshold, center_ratio)
    if target <= snap_min + snap_threshold then
        return ImLerp(snap_min, target, center_ratio)
    end
    if target >= snap_max - snap_threshold then
        return ImLerp(target, snap_max, center_ratio)
    end
    return target
end

--- @param window ImGuiWindow
function CalcNextScrollFromScrollTargetAndClamp(window)
    local scroll = ImVec2()
    ImVec2_Copy(scroll, window.Scroll)
    local decoration_size = ImVec2(window.DecoOuterSizeX1 + window.DecoInnerSizeX1 + window.DecoOuterSizeX2, window.DecoOuterSizeY1 + window.DecoInnerSizeY1 + window.DecoOuterSizeY2)

    for axis_n = ImGuiAxis.X, ImGuiAxis.Y do
        local axis = (axis_n == ImGuiAxis.X) and "x" or "y" -- [Luau] named key: ImVec2[1]/[2] go through IM_VEC2.__index
        if window.ScrollTarget[axis] < FLT_MAX then
            local center_ratio = window.ScrollTargetCenterRatio[axis]
            local scroll_target = window.ScrollTarget[axis]

            if window.ScrollTargetEdgeSnapDist[axis] > 0.0 then
                local snap_min = 0.0
                local snap_max = window.ScrollMax[axis] + window.SizeFull[axis] - decoration_size[axis]
                scroll_target = CalcScrollEdgeSnap(scroll_target, snap_min, snap_max, window.ScrollTargetEdgeSnapDist[axis], center_ratio)
            end

            scroll[axis] = scroll_target - center_ratio * (window.SizeFull[axis] - decoration_size[axis])
        end
        scroll[axis] = ImRound64(ImMax(scroll[axis], 0.0))
        if not window.Collapsed and not window.SkipItems then
            scroll[axis] = ImMin(scroll[axis], window.ScrollMax[axis])
        end
    end

    return scroll
end

-- Scroll to keep newly navigated item fully into view
--- @param window    ImGuiWindow
--- @param item_rect ImRect
--- @param flags?    ImGuiScrollFlags
function ImGui.ScrollToRectEx(window, item_rect, flags)
    if flags == nil then flags = 0 end

    local g = GImGui
    local scroll_rect = ImRect(window.InnerRect.Min - ImVec2(1, 1), window.InnerRect.Max + ImVec2(1, 1))
    scroll_rect.Min.x = ImMin(scroll_rect.Min.x + window.DecoInnerSizeX1, scroll_rect.Max.x)
    scroll_rect.Min.y = ImMin(scroll_rect.Min.y + window.DecoInnerSizeY1, scroll_rect.Max.y)
    -- GetForegroundDrawList(window):AddRect(item_rect.Min, item_rect.Max, IM_COL32(255,0,0,255), 0.0, 0, 5.0) -- [DEBUG]
    -- GetForegroundDrawList(window):AddRect(scroll_rect.Min, scroll_rect.Max, IM_COL32_WHITE) -- [DEBUG]

    -- Check that only one behavior is selected per axis
    IM_ASSERT(bit32.band(flags, ImGuiScrollFlags.MaskX_) == 0 or ImIsPowerOfTwo(bit32.band(flags, ImGuiScrollFlags.MaskX_)))
    IM_ASSERT(bit32.band(flags, ImGuiScrollFlags.MaskY_) == 0 or ImIsPowerOfTwo(bit32.band(flags, ImGuiScrollFlags.MaskY_)))

    -- Defaults
    local in_flags = flags
    if bit32.band(flags, ImGuiScrollFlags.MaskX_) == 0 and window.ScrollbarX then
        flags = bit32.bor(flags, ImGuiScrollFlags.KeepVisibleEdgeX)
    end
    if bit32.band(flags, ImGuiScrollFlags.MaskY_) == 0 then
        flags = bit32.bor(flags, window.Appearing and ImGuiScrollFlags.AlwaysCenterY or ImGuiScrollFlags.KeepVisibleEdgeY)
    end

    local fully_visible_x = item_rect.Min.x >= scroll_rect.Min.x and item_rect.Max.x <= scroll_rect.Max.x
    local fully_visible_y = item_rect.Min.y >= scroll_rect.Min.y and item_rect.Max.y <= scroll_rect.Max.y
    local can_be_fully_visible_x = (item_rect:GetWidth() + g.Style.ItemSpacing.x * 2.0) <= scroll_rect:GetWidth() or (window.AutoFitFramesX > 0) or bit32.band(window.Flags, ImGuiWindowFlags.AlwaysAutoResize) ~= 0
    local can_be_fully_visible_y = (item_rect:GetHeight() + g.Style.ItemSpacing.y * 2.0) <= scroll_rect:GetHeight() or (window.AutoFitFramesY > 0) or bit32.band(window.Flags, ImGuiWindowFlags.AlwaysAutoResize) ~= 0

    if bit32.band(flags, ImGuiScrollFlags.KeepVisibleEdgeX) ~= 0 and not fully_visible_x then
        if item_rect.Min.x < scroll_rect.Min.x or not can_be_fully_visible_x then
            ImGui.SetScrollFromPosX(window, item_rect.Min.x - g.Style.ItemSpacing.x - window.Pos.x, 0.0)
        elseif item_rect.Max.x >= scroll_rect.Max.x then
            ImGui.SetScrollFromPosX(window, item_rect.Max.x + g.Style.ItemSpacing.x - window.Pos.x, 1.0)
        end
    elseif (bit32.band(flags, ImGuiScrollFlags.KeepVisibleCenterX) ~= 0 and not fully_visible_x) or bit32.band(flags, ImGuiScrollFlags.AlwaysCenterX) ~= 0 then
        if can_be_fully_visible_x then
            ImGui.SetScrollFromPosX(window, ImTrunc((item_rect.Min.x + item_rect.Max.x) * 0.5) - window.Pos.x, 0.5)
        else
            ImGui.SetScrollFromPosX(window, item_rect.Min.x - window.Pos.x, 0.0)
        end
    end

    if bit32.band(flags, ImGuiScrollFlags.KeepVisibleEdgeY) ~= 0 and not fully_visible_y then
        if item_rect.Min.y < scroll_rect.Min.y or not can_be_fully_visible_y then
            ImGui.SetScrollFromPosY(window, item_rect.Min.y - g.Style.ItemSpacing.y - window.Pos.y, 0.0)
        elseif item_rect.Max.y >= scroll_rect.Max.y then
            ImGui.SetScrollFromPosY(window, item_rect.Max.y + g.Style.ItemSpacing.y - window.Pos.y, 1.0)
        end
    elseif (bit32.band(flags, ImGuiScrollFlags.KeepVisibleCenterY) ~= 0 and not fully_visible_y) or bit32.band(flags, ImGuiScrollFlags.AlwaysCenterY) ~= 0 then
        if can_be_fully_visible_y then
            ImGui.SetScrollFromPosY(window, ImTrunc((item_rect.Min.y + item_rect.Max.y) * 0.5) - window.Pos.y, 0.5)
        else
            ImGui.SetScrollFromPosY(window, item_rect.Min.y - window.Pos.y, 0.0)
        end
    end

    local next_scroll = CalcNextScrollFromScrollTargetAndClamp(window)
    local delta_scroll = next_scroll - window.Scroll

    -- Also scroll parent window to keep us into view if necessary
    if bit32.band(flags, ImGuiScrollFlags.NoScrollParent) == 0 and bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0 then
        -- FIXME-SCROLL: May be an option?
        if bit32.band(in_flags, bit32.bor(ImGuiScrollFlags.AlwaysCenterX, ImGuiScrollFlags.KeepVisibleCenterX)) ~= 0 then
            in_flags = bit32.bor(bit32.band(in_flags, bit32.bnot(ImGuiScrollFlags.MaskX_)), ImGuiScrollFlags.KeepVisibleEdgeX)
        end
        if bit32.band(in_flags, bit32.bor(ImGuiScrollFlags.AlwaysCenterY, ImGuiScrollFlags.KeepVisibleCenterY)) ~= 0 then
            in_flags = bit32.bor(bit32.band(in_flags, bit32.bnot(ImGuiScrollFlags.MaskY_)), ImGuiScrollFlags.KeepVisibleEdgeY)
        end
        local parent_delta = ImGui.ScrollToRectEx(window.ParentWindow, ImRect(item_rect.Min - delta_scroll, item_rect.Max - delta_scroll), in_flags)
        delta_scroll = delta_scroll + parent_delta
    end

    return delta_scroll
end

--- @return float
function ImGui.GetScrollMaxY()
    local window = GImGui.CurrentWindow
    return window.ScrollMax.y
end

function ImGui.GetScrollMaxX()
    return GImGui.CurrentWindow.ScrollMax.x
end

function ImGui.GetScrollX()
    return GImGui.CurrentWindow.Scroll.x
end

function ImGui.GetScrollY()
    return GImGui.CurrentWindow.Scroll.y
end

--- @param flags? ImGuiScrollFlags
function ImGui.ScrollToItem(flags)
    local g = GImGui
    ImGui.ScrollToRectEx(g.CurrentWindow, g.LastItemData.NavRect, flags or 0)
end

--- @param window    ImGuiWindow
--- @param item_rect ImRect
--- @param flags?    ImGuiScrollFlags
function ImGui.ScrollToRect(window, item_rect, flags)
    ImGui.ScrollToRectEx(window, item_rect, flags or 0)
end

-- center_x_ratio: 0.0 left of last item, 0.5 horizontal center of last item, 1.0 right of last item.
--- @param center_x_ratio? float
function ImGui.SetScrollHereX(center_x_ratio)
    if center_x_ratio == nil then center_x_ratio = 0.5 end
    local g = GImGui
    local window = g.CurrentWindow
    local spacing_x = ImMax(window.WindowPadding.x, g.Style.ItemSpacing.x)
    local target_pos_x = ImLerp(g.LastItemData.Rect.Min.x - spacing_x, g.LastItemData.Rect.Max.x + spacing_x, center_x_ratio)
    ImGui.SetScrollFromPosX(window, target_pos_x - window.Pos.x, center_x_ratio) -- Convert from absolute to local pos

    -- Tweak: snap on edges when aiming at an item very close to the edge
    window.ScrollTargetEdgeSnapDist.x = ImMax(0.0, window.WindowPadding.x - spacing_x)
end

-- center_y_ratio: 0.0 top of last item, 0.5 vertical center of last item, 1.0 bottom of last item.
--- @param center_y_ratio? float
function ImGui.SetScrollHereY(center_y_ratio)
    if center_y_ratio == nil then center_y_ratio = 0.5 end
    local g = GImGui
    local window = g.CurrentWindow
    local spacing_y = ImMax(window.WindowPadding.y, g.Style.ItemSpacing.y)
    local target_pos_y = ImLerp(window.DC.CursorPosPrevLine.y - spacing_y, window.DC.CursorPosPrevLine.y + window.DC.PrevLineSize.y + spacing_y, center_y_ratio)
    ImGui.SetScrollFromPosY(window, target_pos_y - window.Pos.y, center_y_ratio) -- Convert from absolute to local pos

    -- Tweak: snap on edges when aiming at an item very close to the edge
    window.ScrollTargetEdgeSnapDist.y = ImMax(0.0, window.WindowPadding.y - spacing_y)
end

-- Overloads: SetScrollX(scroll_x) / SetScrollX(window, scroll_x)
--- @param window   ImGuiWindow|float
--- @param scroll_x float?
function ImGui.SetScrollX(window, scroll_x)
    if type(window) == "number" then window, scroll_x = GImGui.CurrentWindow, window end
    window.ScrollTarget.x = scroll_x
    window.ScrollTargetCenterRatio.x = 0.0
    window.ScrollTargetEdgeSnapDist.x = 0.0
end

--- @param window   ImGuiWindow
--- @param scroll_y float
function ImGui.SetScrollY(window, scroll_y)
    if type(window) == "number" then window, scroll_y = GImGui.CurrentWindow, window end
    window.ScrollTarget.y = scroll_y
    window.ScrollTargetCenterRatio.y = 0.0
    window.ScrollTargetEdgeSnapDist.y = 0.0
end

-- Note that a local position will vary depending on initial scroll value,
-- This is a little bit confusing so bear with us:
--  - local_pos = (absolution_pos - window.Pos)
--  - So local_x/local_y are 0.0 for a position at the upper-left corner of a window,
--    and generally local_x/local_y are >(padding+decoration) && <(size-padding-decoration) when in the visible area.
--  - They mostly exist because of legacy API.
-- Following the rules above, when trying to work with scrolling code, consider that:
--  - SetScrollFromPosY(0.0) == SetScrollY(0.0 + scroll.y) == has no effect!
--  - SetScrollFromPosY(-scroll.y) == SetScrollY(-scroll.y + scroll.y) == SetScrollY(0.0) == reset scroll. Of course writing SetScrollY(0.0) directly then makes more sense
-- We store a target position so centering and clamping can occur on the next frame when we are guaranteed to have a known window size
--- @param window         ImGuiWindow
--- @param local_x        float
--- @param center_x_ratio float
function ImGui.SetScrollFromPosX(window, local_x, center_x_ratio)
    if type(window) == "number" then window, local_x, center_x_ratio = GImGui.CurrentWindow, window, local_x end
    if center_x_ratio == nil then center_x_ratio = 0.5 end
    IM_ASSERT(center_x_ratio >= 0.0 and center_x_ratio <= 1.0)
    window.ScrollTarget.x = IM_TRUNC(local_x - window.DecoOuterSizeX1 - window.DecoInnerSizeX1 + window.Scroll.x) -- Convert local position to scroll offset
    window.ScrollTargetCenterRatio.x = center_x_ratio
    window.ScrollTargetEdgeSnapDist.x = 0.0
end

--- @param window         ImGuiWindow
--- @param local_y        float
--- @param center_y_ratio float
function ImGui.SetScrollFromPosY(window, local_y, center_y_ratio)
    if type(window) == "number" then window, local_y, center_y_ratio = GImGui.CurrentWindow, window, local_y end
    if center_y_ratio == nil then center_y_ratio = 0.5 end
    IM_ASSERT(center_y_ratio >= 0.0 and center_y_ratio <= 1.0)
    window.ScrollTarget.y = IM_TRUNC(local_y - window.DecoOuterSizeY1 - window.DecoInnerSizeY1 + window.Scroll.y) -- Convert local position to scroll offset
    window.ScrollTargetCenterRatio.y = center_y_ratio
    window.ScrollTargetEdgeSnapDist.y = 0.0
end

-------------------------------------------------------------------------------
-- [SECTION] TOOLTIPS
-------------------------------------------------------------------------------

--- @param tooltip_flags      ImGuiTooltipFlags
--- @param extra_window_flags ImGuiWindowFlags
function ImGui.BeginTooltipEx(tooltip_flags, extra_window_flags)
    local g = GImGui

    local is_dragdrop_tooltip = g.DragDropWithinSource or g.DragDropWithinTarget
    if is_dragdrop_tooltip then
        -- Drag and Drop tooltips are positioning differently than other tooltips:
        -- - offset visibility to increase visibility around mouse.
        -- - never clamp within outer viewport boundary.
        -- We call SetNextWindowPos() to enforce position and disable clamping.
        -- See FindBestWindowPosForPopup() for positioning logic of other tooltips (not drag and drop ones).
        -- local tooltip_pos = g.IO.MousePos - g.ActiveIdClickOffset - g.Style.WindowPadding
        local is_touchscreen = (g.IO.MouseSource == ImGuiMouseSource.TouchScreen)

        if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasPos) == 0 then
            local tooltip_pos
            if is_touchscreen then
                tooltip_pos = g.IO.MousePos + TOOLTIP_DEFAULT_OFFSET_TOUCH * g.Style.MouseCursorScale
            else
                tooltip_pos = g.IO.MousePos + TOOLTIP_DEFAULT_OFFSET_MOUSE * g.Style.MouseCursorScale
            end

            local tooltip_pivot = is_touchscreen and TOOLTIP_DEFAULT_PIVOT_TOUCH or ImVec2(0.0, 0.0)
            ImGui.SetNextWindowPos(tooltip_pos, ImGuiCond.None, tooltip_pivot)
        end

        local bg_alpha = g.Style.Colors[ImGuiCol.PopupBg].w * 0.60
        ImGui.SetNextWindowBgAlpha(bg_alpha)
        -- PushStyleVar(ImGuiStyleVar.Alpha, g.Style.Alpha * 0.60) -- This would be nice but e.g ColorButton with checkerboard has issue with transparent colors :(

        tooltip_flags = bit32.bor(tooltip_flags, ImGuiTooltipFlags.OverridePrevious)
    end

    -- Hide previous tooltip from being displayed. We can't easily "reset" the content of a window so we create a new one.
    if (bit32.band(tooltip_flags, ImGuiTooltipFlags.OverridePrevious) ~= 0) and g.TooltipPreviousWindow ~= nil and g.TooltipPreviousWindow.Active and not ImGui.IsWindowInBeginStack(g.TooltipPreviousWindow) then
        -- IMGUI_DEBUG_LOG("[tooltip] '%s' already active, using +1 for this frame\n", window_name)
        ImGui.SetWindowHiddenAndSkipItemsForCurrentFrame(g.TooltipPreviousWindow)
        g.TooltipOverrideCount = g.TooltipOverrideCount + 1
    end

    local window_name_template = is_dragdrop_tooltip and "##Tooltip_DragDrop_%02d" or "##Tooltip_%02d"
    local window_name = ImFormatString(window_name_template, g.TooltipOverrideCount)

    local flags = bit32.bor(ImGuiWindowFlags.Tooltip, ImGuiWindowFlags.NoInputs, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoMove, ImGuiWindowFlags.NoResize, ImGuiWindowFlags.NoSavedSettings, ImGuiWindowFlags.AlwaysAutoResize)

    ImGui.Begin(window_name, nil, bit32.bor(flags, extra_window_flags))
    -- 2023-03-09: Added bool return value to the API, but currently always returning true.
    -- If this ever returns false we need to update BeginDragDropSource() accordingly.
    -- if (!ret)
    --     End();
    -- return ret;
    return true
end

function ImGui.BeginTooltip()
    return ImGui.BeginTooltipEx(ImGuiTooltipFlags.None, ImGuiWindowFlags.None)
end

function ImGui.BeginItemTooltip()
    if not ImGui.IsItemHovered(ImGuiHoveredFlags.ForTooltip) then
        return false
    end
    return ImGui.BeginTooltipEx(ImGuiTooltipFlags.None, ImGuiWindowFlags.None)
end

function ImGui.EndTooltip()
    IM_ASSERT(bit32.band(ImGui.GetCurrentWindowRead().Flags, ImGuiWindowFlags.Tooltip) ~= 0) -- Mismatched BeginTooltip()/EndTooltip() calls
    ImGui.End()
end

--- @param fmt string
--- @param ... any
function ImGui.SetTooltip(fmt, ...)
    if not ImGui.BeginTooltipEx(ImGuiTooltipFlags.OverridePrevious, ImGuiWindowFlags.None) then
        return
    end
    ImGui.TextV(fmt, ...)
    ImGui.EndTooltip()
end

-- Shortcut to use 'style.HoverFlagsForTooltipMouse' or 'style.HoverFlagsForTooltipNav'.
-- Defaults to == ImGuiHoveredFlags.Stationary | ImGuiHoveredFlags.DelayShort when using the mouse.
--- @param fmt string
--- @param ... any
function ImGui.SetItemTooltip(fmt, ...)
    if ImGui.IsItemHovered(ImGuiHoveredFlags.ForTooltip) then
        ImGui.SetTooltip(fmt, ...)
    end
end

-------------------------------------------------------------------------------
-- [SECTION] POPUPS
-------------------------------------------------------------------------------

-- When a modal popup is open, newly created windows that want focus (i.e. are not popups and do not specify ImGuiWindowFlags.NoFocusOnAppearing)
-- should be positioned behind that modal window, unless the window was created inside the modal begin-stack.
-- In case of multiple stacked modals newly created window honors begin stack order and does not go below its own modal parent.
-- - WindowA            -- FindBlockingModal() returns Modal1
--   - WindowB          --                  .. returns Modal1
--   - Modal1           --                  .. returns Modal2
--      - WindowC       --                  .. returns Modal2
--          - WindowD   --                  .. returns Modal2
--          - Modal2    --                  .. returns Modal2
--            - WindowE --                  .. returns nil
-- Notes:
-- - FindBlockingModal(nil) == nil is generally equivalent to GetTopMostPopupModal() == nil.
--   Only difference is here we check for .Active/WasActive but it may be unnecessary.
--- @param window? ImGuiWindow
function ImGui.FindBlockingModal(window)
    local g = GImGui
    if g.OpenPopupStack.Size <= 0 then
        return nil
    end

    -- Find a modal that has common parent with specified window. Specified window should be positioned behind that modal.
    for i = 1, g.OpenPopupStack.Size do
        repeat
        local popup_data = g.OpenPopupStack.Data[i]
        local popup_window = popup_data.Window
        if popup_window == nil or bit32.band(popup_window.Flags, ImGuiWindowFlags.Modal) == 0 then
            break
        end
        if not popup_window.Active and not popup_window.WasActive then -- Check WasActive, because this code may run before popup renders on current frame, also check Active to handle newly created windows.
            break
        end
        if window == nil then -- FindBlockingModal(nil) test for if FocusWindow(nil) is naturally possible via a mouse click.
            return popup_window
        end
        if ImGui.IsWindowWithinBeginStackOf(window, popup_window) then -- Window may be over modal
            break
        end

        do return popup_window end -- Place window right below first block modal

        until true
    end
    return nil
end

--- @param id           ImGuiID|string
--- @param popup_flags? ImGuiPopupFlags
function ImGui.OpenPopup(id, popup_flags)
    if popup_flags == nil then popup_flags = 0 end

    if type(id) == "number" then
        return ImGui.OpenPopupEx(id, popup_flags)
    else --- @cast id string
        local g = GImGui
        local _id = g.CurrentWindow:GetID(id)
        IMGUI_DEBUG_LOG_POPUP("[popup] OpenPopup(\"%s\" -> 0x%08X)", id, _id)
        return ImGui.OpenPopupEx(_id, popup_flags)
    end
end

-- Mark popup as open (toggle toward open state).
-- - Return true when the popup is toggled open, which allows you to capture local state if needed.
--   You may also call IsWindowAppearing() inside the later BeginPopup() scope if you need to prepare/compute data for the popup.
-- - Popups are closed when user click outside, or activate a pressable item, or CloseCurrentPopup() is called within a BeginPopup()/EndPopup() block.
-- - Popup identifiers are relative to the current ID-stack (so OpenPopup and BeginPopup needs to be at the same level).
-- - One open popup per level of the popup hierarchy (NB: when assigning we reset the Window member of ImGuiPopupRef to nil).
--- @param id          ImGuiID
--- @param popup_flags ImGuiPopupFlags
function ImGui.OpenPopupEx(id, popup_flags)
    local g = GImGui
    local parent_window = g.CurrentWindow
    local current_stack_size = g.BeginPopupStack.Size

    if bit32.band(popup_flags, ImGuiPopupFlags.NoOpenOverExistingPopup) ~= 0 then
        if ImGui.IsPopupOpen(0, ImGuiPopupFlags.AnyPopupId) then
            return false
        end
    end

    local popup_ref = ImGuiPopupData() -- Tagged as new ref as Window will be set back to nil if we write this into OpenPopupStack.
    popup_ref.PopupId = id
    popup_ref.Window = nil
    popup_ref.RestoreNavWindow = g.NavWindow -- When popup closes focus may be restored to NavWindow (depend on window type).
    popup_ref.OpenFrameCount = g.FrameCount
    popup_ref.OpenParentId = parent_window.IDStack:back()
    ImVec2_Copy(popup_ref.OpenPopupPos, ImGui.NavCalcPreferredRefPos(ImGuiWindowFlags.Popup))
    if ImGui.IsMousePosValid(g.IO.MousePos) then
        ImVec2_Copy(popup_ref.OpenMousePos, g.IO.MousePos)
    else
        ImVec2_Copy(popup_ref.OpenMousePos, popup_ref.OpenPopupPos)
    end

    -- IMGUI_DEBUG_LOG_POPUP("[popup] OpenPopupEx(0x%08X)\n", id)
    if g.OpenPopupStack.Size < current_stack_size + 1 then
        g.OpenPopupStack:push_back(popup_ref)
        return true
    else
        -- Gently handle the user mistakenly calling OpenPopup() every frames: it is likely a programming mistake!
        -- However, if we were to run the regular code path, the ui would become completely unusable because the popup will always be
        -- in hidden-while-calculating-size state _while_ claiming focus. Which is extremely confusing situation for the programmer.
        -- Instead, for successive frames calls to OpenPopup(), we silently avoid reopening even if ImGuiPopupFlags.NoReopen is not specified.

        local keep_existing = false
        if g.OpenPopupStack.Data[current_stack_size + 1].PopupId == id then
            if (g.OpenPopupStack.Data[current_stack_size + 1].OpenFrameCount == g.FrameCount - 1) or (bit32.band(popup_flags, ImGuiPopupFlags.NoReopen) ~= 0) then
                keep_existing = true
            end
        end

        if keep_existing then
            -- No reopen
            g.OpenPopupStack.Data[current_stack_size + 1].OpenFrameCount = popup_ref.OpenFrameCount
        else
            -- Reopen: close child popups if any, then flag popup for open/reopen (set position, focus, init navigation)
            ImGui.ClosePopupToLevel(current_stack_size, true)
            g.OpenPopupStack:push_back(popup_ref)
        end

        -- When reopening a popup we first refocus its parent, otherwise if its parent is itself a popup it would get closed by ClosePopupsOverWindow().
        -- This is equivalent to what ClosePopupToLevel() does.
        -- if (g.OpenPopupStack[current_stack_size + 1].PopupId == id)
        --     FocusWindow(parent_window);

        return not keep_existing
    end
end

-- When popups are stacked, clicking on a lower level popups puts focus back to it and close popups above it.
-- This function closes any popups that are over 'ref_window'.
--- @param ref_window?                         ImGuiWindow
--- @param restore_focus_to_window_under_popup bool
function ImGui.ClosePopupsOverWindow(ref_window, restore_focus_to_window_under_popup)
    local g = GImGui
    if g.OpenPopupStack.Size == 0 then
        return
    end

    -- Don't close our own child popup windows.
    -- IMGUI_DEBUG_LOG_POPUP("[popup] ClosePopupsOverWindow(\"%s\") restore_under=%d\n", ref_window and ref_window.Name or "<NULL>", restore_focus_to_window_under_popup)
    local popup_count_to_keep = 0
    if ref_window then
        -- Find the highest popup which is a descendant of the reference window (generally reference window = NavWindow)
        local ref_window_is_descendent_of_popup
        local stop_8041 = false
        while popup_count_to_keep < g.OpenPopupStack.Size do
            repeat
            local popup = g.OpenPopupStack.Data[popup_count_to_keep + 1]
            if not popup.Window then
                break
            end

            IM_ASSERT(bit32.band(popup.Window.Flags, ImGuiWindowFlags.Popup) ~= 0)

            -- Trim the stack unless the popup is a direct parent of the reference window (the reference window is often the NavWindow)
            -- - Clicking/Focusing Window2 won't close Popup1:
            --     Window -> Popup1 -> Window2(Ref)
            -- - Clicking/focusing Popup1 will close Popup2 and Popup3:
            --     Window -> Popup1(Ref) -> Popup2 -> Popup3
            -- - Each popups may contain child windows, which is why we compare .RootWindowDockTree!
            --     Window -> Popup1 -> Popup1_Child -> Popup2 -> Popup2_Child
            -- We step through every popup from bottom to top to validate their position relative to reference window.
            ref_window_is_descendent_of_popup = false
            for n = popup_count_to_keep, g.OpenPopupStack.Size - 1 do
                local popup_window = g.OpenPopupStack.Data[n + 1].Window
                -- if (popup_window.RootWindowDockTree == ref_window.RootWindowDockTree) -- FIXME-MERGE
                if popup_window and ImGui.IsWindowWithinBeginStackOf(ref_window, popup_window) then
                    ref_window_is_descendent_of_popup = true
                    break
                end
            end

            if not ref_window_is_descendent_of_popup then
                stop_8041 = true; break
            end

            until true
            if stop_8041 then break end

            popup_count_to_keep = popup_count_to_keep + 1
        end
    end
    if popup_count_to_keep < g.OpenPopupStack.Size then -- This test is not required but it allows to set a convenient breakpoint on the statement below
        -- IMGUI_DEBUG_LOG_POPUP("[popup] ClosePopupsOverWindow(\"%s\")\n", ref_window and ref_window.Name or "<NULL>")
        ImGui.ClosePopupToLevel(popup_count_to_keep, restore_focus_to_window_under_popup)
    end
end

--- @param remaining                           int  # 0-based
--- @param restore_focus_to_window_under_popup bool
function ImGui.ClosePopupToLevel(remaining, restore_focus_to_window_under_popup)
    local g = GImGui
    -- IMGUI_DEBUG_LOG_POPUP("[popup] ClosePopupToLevel(%d), restore_under=%d\n", remaining, restore_focus_to_window_under_popup)
    IM_ASSERT(remaining >= 0 and remaining < g.OpenPopupStack.Size)
    -- if bit32.band(g.DebugLogFlags, ImGuiDebugLogFlags.EventPopup) ~= 0 then
    --     for n = remaining + 1, g.OpenPopupStack.Size do
    --         local popup = g.OpenPopupStack.Data[n]
    --         IMGUI_DEBUG_LOG_POPUP("[popup] - Closing PopupID 0x%08X Window \"%s\"", popup.PopupId, popup.Window and popup.Window.Name or nil)
    --     end
    -- end

    -- Trim open popup stack
    -- FIXME: is it safer to full copy here?
    local prev_popup = g.OpenPopupStack.Data[remaining + 1]
    g.OpenPopupStack:resize(remaining)

    -- Restore focus (unless popup window was not yet submitted, and didn't have a chance to take focus anyhow. See #7325 for an edge case)
    if restore_focus_to_window_under_popup and prev_popup.Window then
        local popup_window = prev_popup.Window
        local focus_window
        if bit32.band(popup_window.Flags, ImGuiWindowFlags.ChildMenu) ~= 0 then
            focus_window = popup_window.ParentWindow
        else
            focus_window = prev_popup.RestoreNavWindow
        end

        if focus_window and not focus_window.WasActive then
            ImGui.FocusTopMostWindowUnderOne(popup_window, nil, nil, ImGuiFocusRequestFlags.RestoreFocusedChild) -- Fallback
        else
            local focus_flags = (g.NavLayer == ImGuiNavLayer.Main) and ImGuiFocusRequestFlags.RestoreFocusedChild or ImGuiFocusRequestFlags.None
            ImGui.FocusWindow(focus_window, focus_flags)
        end
    end
end

-- Close the popup we have begin-ed into.
function ImGui.CloseCurrentPopup()
    local g = GImGui
    local popup_idx = g.BeginPopupStack.Size
    if popup_idx < 1 or popup_idx > g.OpenPopupStack.Size or g.BeginPopupStack.Data[popup_idx].PopupId ~= g.OpenPopupStack.Data[popup_idx].PopupId then
        return
    end

    -- Closing a menu closes its top-most parent popup (unless a modal)
    while popup_idx > 1 do
        local popup_window = g.OpenPopupStack.Data[popup_idx].Window
        local parent_popup_window = g.OpenPopupStack.Data[popup_idx - 1].Window
        local close_parent = false
        if popup_window and bit32.band(popup_window.Flags, ImGuiWindowFlags.ChildMenu) ~= 0 then
            if parent_popup_window and not (bit32.band(parent_popup_window.Flags, ImGuiWindowFlags.MenuBar) ~= 0) then
                close_parent = true
            end
        end

        if not close_parent then
            break
        end

        popup_idx = popup_idx - 1
    end

    -- IMGUI_DEBUG_LOG_POPUP("[popup] CloseCurrentPopup %d -> %d\n", g.BeginPopupStack.Size, popup_idx)
    ImGui.ClosePopupToLevel(popup_idx - 1, true)

    -- A common pattern is to close a popup when selecting a menu item/selectable that will open another window.
    -- To improve this usage pattern, we avoid nav highlight for a single frame in the parent window.
    -- Similarly, we could avoid mouse hover highlight in this window but it is less visually problematic.
    local window = g.NavWindow
    if window then
        window.DC.NavHideHighlightOneFrame = true
    end
end

-- Attention! BeginPopup() adds default flags when calling BeginPopupEx()!
--- @param id                 ImGuiID
--- @param extra_window_flags ImGuiWindowFlags
function ImGui.BeginPopupEx(id, extra_window_flags)
    local g = GImGui
    if not ImGui.IsPopupOpen(id, ImGuiPopupFlags.None) then
        g.NextWindowData:ClearFlags() -- We behave like Begin() and need to consume those values
        return false
    end

    IM_ASSERT(bit32.band(extra_window_flags, ImGuiWindowFlags.ChildMenu) == 0) -- Use BeginPopupMenuEx()
    local name = ImFormatString("##Popup_%08x", id) -- No recycling, so we can close/open during the same frame

    local is_open
    _, is_open = ImGui.Begin(name, nil, bit32.bor(extra_window_flags, ImGuiWindowFlags.Popup, ImGuiWindowFlags.NoDocking))

    if not is_open then -- NB: Begin can return false when the popup is completely clipped (e.g. zero size display)
        ImGui.EndPopup()
    end
    -- g.CurrentWindow.FocusRouteParentWindow = g.CurrentWindow.ParentWindowInBeginStack
    return is_open
end

--- @param id                 ImGuiID
--- @param label              any
--- @param extra_window_flags ImGuiWindowFlags
function ImGui.BeginPopupMenuEx(id, label, extra_window_flags)
    local g = GImGui
    if not ImGui.IsPopupOpen(id, ImGuiPopupFlags.None) then
        g.NextWindowData:ClearFlags() -- We behave like Begin() and need to consume those values
        return false
    end

    -- As we bypass BeginChild(), set ImGuiChildFlags.AlwaysAutoResize as it is checked independently from ImGuiWindowFlags.AlwaysAutoResize for now (see #9355)
    -- Ideally we should remove setting ImGuiWindowFlags.AlwaysAutoResize in BeginChild().
    if bit32.band(extra_window_flags, ImGuiWindowFlags.ChildWindow) ~= 0 and bit32.band(extra_window_flags, ImGuiWindowFlags.AlwaysAutoResize) ~= 0 then
        ImGui.SetNextWindowChildFlags(ImGuiChildFlags.AlwaysAutoResize, true)
    end

    IM_ASSERT(bit32.band(extra_window_flags, ImGuiWindowFlags.ChildMenu) ~= 0)
    local name = ImFormatString("%s###Menu_%02d", label, g.BeginMenuDepth) -- Recycle windows based on depth
    local is_open
    _, is_open = ImGui.Begin(name, nil, bit32.bor(extra_window_flags, ImGuiWindowFlags.Popup))
    if not is_open then -- NB: Begin can return false when the popup is completely clipped (e.g. zero size display)
        ImGui.EndPopup()
    end
    -- g.CurrentWindow.FocusRouteParentWindow = g.CurrentWindow.ParentWindowInBeginStack
    return is_open
end

--- @param str_id string
--- @param flags? ImGuiWindowFlags
function ImGui.BeginPopup(str_id, flags)
    if flags == nil then flags = 0 end

    local g = GImGui
    if g.OpenPopupStack.Size <= g.BeginPopupStack.Size then -- Early out for performance
        g.NextWindowData:ClearFlags() -- We behave like Begin() and need to consume those values
        return false
    end
    flags = bit32.bor(flags, ImGuiWindowFlags.AlwaysAutoResize, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoSavedSettings)
    local id = g.CurrentWindow:GetID(str_id)
    return ImGui.BeginPopupEx(id, flags)
end

function ImGui.EndPopup()
    local g = GImGui
    local window = g.CurrentWindow
    IM_ASSERT_USER_ERROR_RET((bit32.band(window.Flags, ImGuiWindowFlags.Popup) ~= 0) and (g.BeginPopupStack.Size > 0), "Calling EndPopup() in wrong window!")

    -- Make all menus and popups wrap around for now, may need to expose that policy (e.g. focus scope could include wrap/loop policy flags used by new move requests)
    if g.NavWindow == window then
        ImGui.NavMoveRequestTryWrapping(window, ImGuiNavMoveFlags.LoopY)
    end

    -- Child-popups don't need to be laid out
    local backup_within_end_popup_id = g.WithinEndPopupID
    local backup_within_end_child_id = g.WithinEndChildID
    g.WithinEndPopupID = window.ID
    if bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0 then
        g.WithinEndChildID = window.ID
    end

    ImGui.End()
    g.WithinEndPopupID = backup_within_end_popup_id
    g.WithinEndChildID = backup_within_end_child_id
end

-- r_avoid = the rectangle to avoid (e.g. for tooltip it is a rectangle around the mouse cursor which we want to avoid. for popups it's a small point around the cursor.)
-- r_outer = the visible area rectangle, minus safe area padding. If our popup size won't fit because of safe area padding we ignore it.
-- (r_outer is usually equivalent to the viewport rectangle minus padding, but when multi-viewports are enabled and monitor
--  information are available, it may represent the entire platform monitor from the frame of reference of the current viewport.
--  this allows us to have tooltips/popups displayed out of the parent viewport.)
--- @param ref_pos  ImVec2
--- @param size     ImVec2
--- @param last_dir ImGuiDir
--- @param r_outer  ImRect
--- @param r_avoid  ImRect
--- @param policy   ImGuiPopupPositionPolicy
--- @return ImVec2 # Best Window Pos For Popup
--- @return int    # Updated last_dir
--- @nodiscard
function ImGui.FindBestWindowPosForPopupEx(ref_pos, size, last_dir, r_outer, r_avoid, policy)
    local base_pos_clamped

    -- Combo Box policy (we want a connecting edge)
    if policy == ImGuiPopupPositionPolicy.ComboBox then
        local dir_preferred_order = {ImGuiDir.Down, ImGuiDir.Right, ImGuiDir.Left, ImGuiDir.Up}

        for n = (last_dir ~= ImGuiDir.None) and 0 or 1, ImGuiDir.COUNT do
            repeat
            local dir = (n == 0) and last_dir or dir_preferred_order[n]

            if n ~= 0 and dir == last_dir then -- Already tried this direction?
                break
            end

            local pos
            if     dir == ImGuiDir.Down  then pos = ImVec2(r_avoid.Min.x, r_avoid.Max.y)                   -- Below, Toward Right (default)
            elseif dir == ImGuiDir.Right then pos = ImVec2(r_avoid.Min.x, r_avoid.Min.y - size.y)          -- Above, Toward Right
            elseif dir == ImGuiDir.Left  then pos = ImVec2(r_avoid.Max.x - size.x, r_avoid.Max.y)          -- Below, Toward Left
            elseif dir == ImGuiDir.Up    then pos = ImVec2(r_avoid.Max.x - size.x, r_avoid.Min.y - size.y) -- Above, Toward Left
            end

            if not r_outer:Contains(ImRect(pos, pos + size)) then
                break
            end

            last_dir = dir
            do return pos, last_dir end

            until true
        end
    end

    -- Tooltip and Default popup policy
    -- (Always first try the direction we used on the last frame, if any)
    if policy == ImGuiPopupPositionPolicy.Tooltip or policy == ImGuiPopupPositionPolicy.Default then
        local dir_preferred_order = {ImGuiDir.Right, ImGuiDir.Down, ImGuiDir.Up, ImGuiDir.Left}

        for n = (last_dir ~= ImGuiDir.None) and 0 or 1, ImGuiDir.COUNT do
            repeat
            local dir = (n == 0) and last_dir or dir_preferred_order[n]

            if n ~= 0 and dir == last_dir then -- Already tried this direction?
                break
            end

            local avail_w = ((dir == ImGuiDir.Left) and r_avoid.Min.x or r_outer.Max.x) - ((dir == ImGuiDir.Right) and r_avoid.Max.x or r_outer.Min.x)
            local avail_h = ((dir == ImGuiDir.Up)   and r_avoid.Min.y or r_outer.Max.y) - ((dir == ImGuiDir.Down)  and r_avoid.Max.y or r_outer.Min.y)

            -- If there's not enough room on one axis, there's no point in positioning on a side on this axis (e.g. when not enough width, use a top/bottom position to maximize available width)
            if avail_w < size.x and (dir == ImGuiDir.Left or dir == ImGuiDir.Right) then
                break
            end

            if avail_h < size.y and (dir == ImGuiDir.Up or dir == ImGuiDir.Down) then
                break
            end

            base_pos_clamped = ImClamp(ref_pos, r_outer.Min, r_outer.Max - size)
            local pos = ImVec2()
            pos.x = (dir == ImGuiDir.Left) and (r_avoid.Min.x - size.x) or ((dir == ImGuiDir.Right) and r_avoid.Max.x or base_pos_clamped.x)
            pos.y = (dir == ImGuiDir.Up)   and (r_avoid.Min.y - size.y) or ((dir == ImGuiDir.Down)  and r_avoid.Max.y or base_pos_clamped.y)

            -- Clamp top-left corner of popup
            pos.x = ImMax(pos.x, r_outer.Min.x)
            pos.y = ImMax(pos.y, r_outer.Min.y)

            last_dir = dir
            do return pos, last_dir end

            until true
        end
    end

    -- Fallback when not enough room:
    last_dir = ImGuiDir.None

    -- For tooltip we prefer avoiding the cursor at all cost even if it means that part of the tooltip won't be visible.
    if policy == ImGuiPopupPositionPolicy.Tooltip then
        return ref_pos + ImVec2(2, 2), last_dir
    end

    -- Otherwise try to keep within display
    local pos = ImVec2(ref_pos.x, ref_pos.y)
    pos.x = ImMax(ImMin(pos.x + size.x, r_outer.Max.x) - size.x, r_outer.Min.x)
    pos.y = ImMax(ImMin(pos.y + size.y, r_outer.Max.y) - size.y, r_outer.Min.y)
    return pos, last_dir
end

-- Note that this is used for popups, which can overlap the non work-area of individual viewports.
--- @param window ImGuiWindow
--- @return ImRect
--- @nodiscard
function ImGui.GetPopupAllowedExtentRect(window)
    local g = GImGui
    local r_screen = ImRect()

    if window.ViewportAllowPlatformMonitorExtend >= 1 then
        -- Extent with be in the frame of reference of the given viewport (so Min is likely to be negative here)
        local monitor = g.PlatformIO.Monitors.Data[window.ViewportAllowPlatformMonitorExtend]
        ImVec2_Copy(r_screen.Min, monitor.WorkPos)
        ImVec2_Copy(r_screen.Max, monitor.WorkPos + monitor.WorkSize)
    else
        -- Use the full viewport area (not work area) for popups
        r_screen = window.Viewport:GetMainRect()
    end

    local padding = g.Style.DisplaySafeAreaPadding
    r_screen:Expand(ImVec2((r_screen:GetWidth() > padding.x * 2) and -padding.x or 0.0, (r_screen:GetHeight() > padding.y * 2) and -padding.y or 0.0))

    return r_screen
end

--- @param window ImGuiWindow
--- @return ImVec2
--- @nodiscard
function ImGui.FindBestWindowPosForPopup(window)
    local g = GImGui

    local r_outer = ImGui.GetPopupAllowedExtentRect(window)

    if bit32.band(window.Flags, ImGuiWindowFlags.ChildMenu) ~= 0 then
        -- Child menus typically request _any_ position within the parent menu item, and then we move the new menu outside the parent bounds.
        -- This is how we end up with child menus appearing (most-commonly) on the right of the parent menu.
        local parent_window = window.ParentWindow
        local horizontal_overlap = g.Style.ItemInnerSpacing.x  -- We want some overlap to convey the relative depth of each menu (currently the amount of overlap is hard-coded to style.ItemSpacing.x).

        local r_avoid
        if parent_window.DC.MenuBarAppending then
            r_avoid = ImRect(-FLT_MAX, parent_window.ClipRect.Min.y, FLT_MAX, parent_window.ClipRect.Max.y)  -- Avoid parent menu-bar. If we wanted multi-line menu-bar, we may instead want to have the calling window setup e.g. a NextWindowData.PosConstraintAvoidRect field
        else
            r_avoid = ImRect(parent_window.Pos.x + horizontal_overlap, -FLT_MAX, parent_window.Pos.x + parent_window.Size.x - horizontal_overlap - parent_window.ScrollbarSizes.x, FLT_MAX)
        end

        local pos
        pos, window.AutoPosLastDirection = ImGui.FindBestWindowPosForPopupEx(window.Pos, window.Size, window.AutoPosLastDirection, r_outer, r_avoid, ImGuiPopupPositionPolicy.Default)
        return pos
    end

    if bit32.band(window.Flags, ImGuiWindowFlags.Popup) ~= 0 then
        local pos
        pos, window.AutoPosLastDirection = ImGui.FindBestWindowPosForPopupEx(window.Pos, window.Size, window.AutoPosLastDirection, r_outer, ImRect(window.Pos, window.Pos), ImGuiPopupPositionPolicy.Default)  -- Ideally we'd disable r_avoid here
        return pos
    end

    if bit32.band(window.Flags, ImGuiWindowFlags.Tooltip) ~= 0 then
        -- Position tooltip (always follows mouse + clamp within outer boundaries)
        -- FIXME:
        -- - Too many paths. One problem is that FindBestWindowPosForPopupEx() doesn't allow passing a suggested position (so touch screen path doesn't use it by default).
        -- - Drag and drop tooltips are not using this path either: BeginTooltipEx() manually sets their position.
        -- - Require some tidying up. In theory we could handle both cases in same location, but requires a bit of shuffling
        --   as drag and drop tooltips are calling SetNextWindowPos() leading to 'window_pos_set_by_api' being set in Begin().
        IM_ASSERT(g.CurrentWindow == window)
        local scale = g.Style.MouseCursorScale
        local ref_pos = ImGui.NavCalcPreferredRefPos(ImGuiWindowFlags.Tooltip)

        if g.IO.MouseSource == ImGuiMouseSource.TouchScreen and ImGui.NavCalcPreferredRefPosSource(ImGuiWindowFlags.Tooltip) == ImGuiInputSource.Mouse then
            local tooltip_pos = ref_pos + TOOLTIP_DEFAULT_OFFSET_TOUCH * scale - TOOLTIP_DEFAULT_PIVOT_TOUCH * window.Size
            if r_outer:Contains(ImRect(tooltip_pos, tooltip_pos + window.Size)) then
                return tooltip_pos
            end
        end

        local tooltip_pos = ref_pos + TOOLTIP_DEFAULT_OFFSET_MOUSE * scale
        local r_avoid
        if g.NavCursorVisible and g.NavHighlightItemUnderNav and not g.IO.ConfigNavMoveSetMousePos then
            r_avoid = ImRect(ref_pos.x - 16, ref_pos.y - 8, ref_pos.x + 16, ref_pos.y + 8)
        else
            r_avoid = ImRect(ref_pos.x - 16, ref_pos.y - 8, ref_pos.x + 24 * scale, ref_pos.y + 24 * scale)  -- FIXME: Hard-coded based on mouse cursor shape expectation. Exact dimension not very important.
        end
        -- ImGui.GetForegroundDrawList():AddRect(r_avoid.Min, r_avoid.Max, IM_COL32(255, 0, 255, 255))

        local pos
        pos, window.AutoPosLastDirection = ImGui.FindBestWindowPosForPopupEx(tooltip_pos, window.Size, window.AutoPosLastDirection, r_outer, r_avoid, ImGuiPopupPositionPolicy.Tooltip)
        return pos
    end

    IM_ASSERT(false)

    return window.Pos
end

--- @param flags ImGuiPopupFlags
--- @return ImGuiMouseButton
function ImGui.GetMouseButtonFromPopupFlags(flags)
    IM_ASSERT(bit32.band(flags, ImGuiPopupFlags.InvalidMask_) == 0)
    if bit32.band(flags, ImGuiPopupFlags.MouseButtonMask_) ~= 0 then
        return bit32.rshift(bit32.band(flags, ImGuiPopupFlags.MouseButtonMask_), ImGuiPopupFlags.MouseButtonShift_) - 1
    end

    return ImGuiMouseButton.Right -- Default == 1
end

--- @param popup_flags ImGuiPopupFlags
--- @param id          ImGuiID

function ImGui.IsPopupOpenRequestForItem(popup_flags, id)
    local g = GImGui
    local mouse_button = ImGui.GetMouseButtonFromPopupFlags(popup_flags)
    if ImGui.IsMouseReleased(mouse_button) and ImGui.IsItemHovered(ImGuiHoveredFlags.AllowWhenBlockedByPopup) then
        return true
    end
    if g.NavOpenContextMenuItemId == id and (ImGui.IsItemFocused() or id == g.CurrentWindow.MoveId) then
        return true
    end
    return false
end

-- Helper to open a popup if mouse button is released over the item
-- - This is essentially the same as BeginPopupContextItem() but without the trailing BeginPopup()
--- @param str_id?      string
--- @param popup_flags? ImGuiPopupFlags

function ImGui.OpenPopupOnItemClick(str_id, popup_flags)
    if popup_flags == nil then popup_flags = 0 end

    local g = GImGui
    if ImGui.IsPopupOpenRequestForItem(popup_flags, g.LastItemData.ID) then
        local window = g.CurrentWindow
        local id
        if str_id then id = window:GetID(str_id) else id = g.LastItemData.ID end -- If user hasn't passed an ID, we can use the LastItemID. Using LastItemID as a Popup ID won't conflict!
        IM_ASSERT(id ~= 0)                                                         -- You cannot pass a nil str_id if the last item has no identifier (e.g. a Text() item)
        return ImGui.OpenPopupEx(id, popup_flags)
    end

    return false
end

-- This is a helper to handle the simplest case of associating one named popup to one given widget.
-- - To create a popup associated to the last item, you generally want to pass a nil value to str_id.
-- - To create a popup with a specific identifier, pass it in str_id.
--    - This is useful when using BeginPopupContextItem() on an item which doesn't have an identifier, e.g. a Text() call.
--    - This is useful when multiple code locations may want to manipulate/open the same popup, given an explicit id.
-- - You may want to handle the whole on user side if you have specific needs (e.g. tweaking IsItemHovered() parameters).
--   This is essentially the same as:
--       id = str_id ? GetID(str_id) : GetItemID();
--       OpenPopupOnItemClick(str_id, ImGuiPopupFlags_MouseButtonRight);
--       return BeginPopup(id);
--   Which is essentially the same as:
--       id = str_id ? GetID(str_id) : GetItemID();
--       if (IsItemHovered() && IsMouseReleased(ImGuiMouseButton_Right))
--           OpenPopup(id);
--       return BeginPopup(id);
--   The main difference being that this is tweaked to avoid computing the ID twice.
--- @param str_id?      string
--- @param popup_flags? ImGuiPopupFlags
--- @return bool
function ImGui.BeginPopupContextItem(str_id, popup_flags)
    if popup_flags == nil then popup_flags = 0 end

    local g = GImGui
    local window = g.CurrentWindow
    if window.SkipItems then
        return false
    end
    local id
    if str_id then id = window:GetID(str_id) else id = g.LastItemData.ID end -- If user hasn't passed an ID, we can use the LastItem ID. Using LastItem ID as a Popup ID won't conflict!
    IM_ASSERT(id ~= 0)                                                         -- You cannot pass a nil str_id if the last item has no identifier (e.g. a Text() item)
    if ImGui.IsPopupOpenRequestForItem(popup_flags, g.LastItemData.ID) then
        ImGui.OpenPopupEx(id, popup_flags)
    end
    return ImGui.BeginPopupEx(id, bit32.bor(ImGuiWindowFlags.AlwaysAutoResize, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoSavedSettings))
end

-------------------------------------------------------------------------------
-- [SECTION] KEYBOARD/GAMEPAD NAVIGATION
-------------------------------------------------------------------------------

-- FIXME-NAV: The existence of SetNavID vs SetFocusID vs FocusWindow() needs to be clarified/reworked.
-- In our terminology those should be interchangeable, yet right now this is super confusing.
-- Those two functions are merely a legacy artifact, so at minimum naming should be clarified.

--- @param id ImGuiID
function ImGui.PushFocusScope(id)
    local g = GImGui
    local data = ImGuiFocusScopeData()
    data.ID = id
    data.WindowID = g.CurrentWindow.ID
    g.FocusScopeStack:push_back(data)
    g.CurrentFocusScopeId = id
end

function ImGui.PopFocusScope()
    local g = GImGui
    -- TODO: IM_ASSERT_USER_ERROR_RET(g.FocusScopeStack.Size > g.StackSizesInBeginForCurrentWindow.SizeOfFocusScopeStack, "Calling PopFocusScope() too many times!")
    g.FocusScopeStack:pop_back()
    if g.FocusScopeStack.Size > 0 then
        g.CurrentFocusScopeId = g.FocusScopeStack:back().ID
    else
        g.CurrentFocusScopeId = 0
    end
end

--- @param focus_scope_id ImGuiID
function ImGui.IsInNavFocusRoute(focus_scope_id)
    local g = GImGui
    if g.NavFocusScopeId == focus_scope_id then
        return true
    end
    for _, focus_scope in g.NavFocusRoute:iter() do
        if focus_scope.ID == focus_scope_id then
            return true
        end
    end
    return false
end

--- @param focus_scope_id ImGuiID
function ImGui.SetNavFocusScope(focus_scope_id)
    local g = GImGui
    g.NavFocusScopeId = focus_scope_id
    g.NavFocusRoute:resize(0) -- Invalidate
    if focus_scope_id == 0 then
        return
    end
    IM_ASSERT(g.NavWindow ~= nil)

    -- Store current path (in reverse order)
    if focus_scope_id == g.CurrentFocusScopeId then
        -- Top of focus stack contains local focus scopes inside current window
        for n = g.FocusScopeStack.Size, 1, -1 do
            local data = g.FocusScopeStack.Data[n]
            if data.WindowID ~= g.CurrentWindow.ID then
                break
            end
            g.NavFocusRoute:push_back(data)
        end
    elseif focus_scope_id == g.NavWindow.NavRootFocusScopeId then
        local data = ImGuiFocusScopeData()
        data.ID = focus_scope_id
        data.WindowID = g.NavWindow.ID
        g.NavFocusRoute:push_back(data)
    else
        return
    end

    -- Then follow on manually set ParentWindowForFocusRoute field (#6798)
    local window = g.NavWindow.ParentWindowForFocusRoute
    while window ~= nil do
        local data = ImGuiFocusScopeData()
        data.ID = window.NavRootFocusScopeId
        data.WindowID = window.ID
        g.NavFocusRoute:push_back(data)
        window = window.ParentWindowForFocusRoute
    end
    IM_ASSERT(g.NavFocusRoute.Size < 100) -- Maximum depth is technically 251 as per CalcRoutingScore(): 254 - 3
end

function ImGui.SetItemDefaultFocus()
    local g = GImGui
    local window = g.CurrentWindow
    if not window.Appearing then
        return
    end
    if g.NavWindow ~= window.RootWindowForNav or (not g.NavInitRequest and g.NavInitResult.ID == 0) or g.NavLayer ~= window.DC.NavLayerCurrent then
        return
    end

    g.NavInitRequest = false
    ImGui.NavApplyItemToResult(g.NavInitResult)
    ImGui.NavUpdateAnyRequestFlag()

    -- Scroll could be done in NavInitRequestApplyResult() via an opt-in flag (we however don't want regular init requests to scroll)
    if not window.ClipRect:Contains(g.LastItemData.Rect) then
        ImGui.ScrollToRectEx(window, g.LastItemData.Rect, ImGuiScrollFlags.None)
    end
end

-- (was called NavRestoreHighlightAfterMove() before 1.91.4)
function ImGui.SetNavCursorVisibleAfterMove()
    local g = GImGui
    if g.NavWindow and (bit32.band(g.NavWindow.Flags, ImGuiWindowFlags.NoNavInputs) ~= 0) then
        g.NavCursorVisible = false
    elseif g.NavInputSource == ImGuiInputSource.Keyboard and (bit32.band(g.IO.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard) == 0) then
        g.NavCursorVisible = false
    elseif g.NavInputSource == ImGuiInputSource.Gamepad and (bit32.band(g.IO.ConfigFlags, ImGuiConfigFlags.NavEnableGamepad) == 0) then
        g.NavCursorVisible = false
    elseif g.IO.ConfigNavCursorVisibleAuto then
        g.NavCursorVisible = true
    end
    g.NavHighlightItemUnderNav = true
    g.NavMousePosDirty = true
end

--- @param window? ImGuiWindow
function ImGui.SetNavWindow(window)
    local g = GImGui
    if g.NavWindow ~= window then
        -- IMGUI_DEBUG_LOG_FOCUS("[focus] SetNavWindow(\"%s\")", window and window.Name or "<NULL>")
        g.NavWindow = window
        g.NavLastValidSelectionUserData = ImGuiSelectionUserData_Invalid
    end
    g.NavInitRequest = false
    g.NavMoveSubmitted = false
    g.NavMoveScoringItems = false
    ImGui.NavUpdateAnyRequestFlag()
end

--- @param axis ImGuiAxis
function ImGui.NavClearPreferredPosForAxis(axis)
    local g = GImGui
    g.NavWindow.RootWindowForNav.NavPreferredScoringPosRel[g.NavLayer][axis] = FLT_MAX
end

--- @param id             ImGuiID
--- @param nav_layer      ImGuiNavLayer
--- @param focus_scope_id ImGuiID
--- @param rect_rel       ImRect
function ImGui.SetNavID(id, nav_layer, focus_scope_id, rect_rel)
    local g = GImGui
    IM_ASSERT(g.NavWindow ~= nil)
    IM_ASSERT(nav_layer == ImGuiNavLayer.Main or nav_layer == ImGuiNavLayer.Menu)
    g.NavId = id
    g.NavLayer = nav_layer
    ImGui.SetNavFocusScope(focus_scope_id)
    g.NavWindow.NavLastIds[nav_layer] = id
    ImRect_Copy(g.NavWindow.NavRectRel[nav_layer], rect_rel)

    -- Clear preferred scoring position (NavMoveRequestApplyResult() will tend to restore it)
    ImGui.NavClearPreferredPosForAxis(ImGuiAxis.X)
    ImGui.NavClearPreferredPosForAxis(ImGuiAxis.Y)
end

-- FIXME: This could be replaced by updating a frame number in each window when (window == NavWindow) and (NavLayer == 0).
-- This way we could find the last focused window among our children. It would be much less confusing this way?
--- @param nav_window ImGuiWindow
function ImGui.NavSaveLastChildNavWindowIntoParent(nav_window)
    local parent = nav_window
    while parent and parent.RootWindow ~= parent and bit32.band(parent.Flags, bit32.bor(ImGuiWindowFlags.Popup, ImGuiWindowFlags.ChildMenu)) == 0 do
        parent = parent.ParentWindow
    end
    if parent and parent ~= nav_window then
        parent.NavLastChildNavWindow = nav_window
    end
end

-- Restore the last focused child.
-- Call when we are expected to land on the Main Layer (0) after FocusWindow()
--- @param window ImGuiWindow
function ImGui.NavRestoreLastChildNavWindow(window)
    if window.NavLastChildNavWindow and window.NavLastChildNavWindow.WasActive then
        return window.NavLastChildNavWindow
    end
    return window
end

--- @param layer ImGuiNavLayer
function ImGui.NavRestoreLayer(layer)
    local g = GImGui
    if layer == ImGuiNavLayer.Main then
        local prev_nav_window = g.NavWindow
        g.NavWindow = ImGui.NavRestoreLastChildNavWindow(g.NavWindow) -- FIXME-NAV: Should clear ongoing nav requests?
        g.NavLastValidSelectionUserData = ImGuiSelectionUserData_Invalid
        -- if (prev_nav_window) IMGUI_DEBUG_LOG_FOCUS("[focus] NavRestoreLayer: from \"%s\" to SetNavWindow(\"%s\")\n", prev_nav_window->Name, g.NavWindow->Name)
    end
    local window = g.NavWindow
    if window.NavLastIds[layer] ~= 0 then
        ImGui.SetNavID(window.NavLastIds[layer], layer, 0, window.NavRectRel[layer])
    else
        g.NavLayer = layer
        ImGui.NavInitWindow(window, true)
    end
end

--- @param id ImGuiID
function ImGui.NavHighlightActivated(id)
    local g = GImGui
    g.NavHighlightActivatedId = id
    g.NavHighlightActivatedTimer = NAV_ACTIVATE_HIGHLIGHT_TIMER
end

function ImGui.NavUpdateAnyRequestFlag()
    local g = GImGui
    g.NavAnyRequest = g.NavMoveScoringItems or g.NavInitRequest or (IMGUI_DEBUG_NAV_SCORING and g.NavWindow ~= nil)
    if g.NavAnyRequest then
        IM_ASSERT(g.NavWindow ~= nil)
    end
end

-- This needs to be called before we submit any widget (aka in or before Begin)
--- @param window       ImGuiWindow
--- @param force_reinit bool
function ImGui.NavInitWindow(window, force_reinit)
    -- FIXME: ChildWindow test here is wrong for docking
    local g = GImGui
    IM_ASSERT(window == g.NavWindow)

    if bit32.band(window.Flags, ImGuiWindowFlags.NoNavInputs) ~= 0 then
        g.NavId = 0
        ImGui.SetNavFocusScope(window.NavRootFocusScopeId)
        return
    end

    local init_for_nav = false
    if window == window.RootWindow or bit32.band(window.Flags, ImGuiWindowFlags.Popup) ~= 0 or window.NavLastIds[0] == 0 or force_reinit then
        init_for_nav = true
    end
    -- IMGUI_DEBUG_LOG_NAV("[nav] NavInitRequest: from NavInitWindow(), init_for_nav=%d, window=\"%s\", layer=%d", init_for_nav, window->Name, g.NavLayer)
    if init_for_nav then
        ImGui.SetNavID(0, g.NavLayer, window.NavRootFocusScopeId, ImRect())
        g.NavInitRequest = true
        g.NavInitRequestFromMove = false
        g.NavInitResult.ID = 0
        ImGui.NavUpdateAnyRequestFlag()
    else
        g.NavId = window.NavLastIds[0]
        ImGui.SetNavFocusScope(window.NavRootFocusScopeId)
    end
end

-- Positioning logic altered slightly for remote activation: for Popup we want to use item rect, for Tooltip we leave things alone. (#9138)
-- When calling for ImGuiWindowFlags.Popup we use LastItemData.
--- @param window_type ImGuiWindowFlags
--- @return ImGuiInputSource
function ImGui.NavCalcPreferredRefPosSource(window_type)
    local g = GImGui
    local window = g.NavWindow

    local activated_shortcut = g.ActiveId ~= 0 and g.ActiveIdFromShortcut and g.ActiveId == g.LastItemData.ID
    if (bit32.band(window_type, ImGuiWindowFlags.Popup) ~= 0) and activated_shortcut then
        return ImGuiInputSource.Keyboard
    end

    if not g.NavCursorVisible or not g.NavHighlightItemUnderNav or not window then
        return ImGuiInputSource.Mouse
    else
        return ImGuiInputSource.Keyboard  -- or Nav in general
    end
end

--- @param window_type ImGuiWindowFlags
--- @return ImVec2
--- @nodiscard
function ImGui.NavCalcPreferredRefPos(window_type)
    local g = GImGui
    local window = g.NavWindow
    local source = ImGui.NavCalcPreferredRefPosSource(window_type)

    if source == ImGuiInputSource.Mouse then
        -- Mouse (we need a fallback in case the mouse becomes invalid after being used)
        -- The +1.0f offset when stored by OpenPopupEx() allows reopening this or another popup (same or another mouse button) while not moving the mouse, it is pretty standard.
        -- In theory we could move that +1.0f offset in OpenPopupEx()
        local p = ImGui.IsMousePosValid(g.IO.MousePos) and g.IO.MousePos or g.MouseLastValidPos
        return ImVec2(p.x + 1.0, p.y)
    else
        -- When navigation is active and mouse is disabled, pick a position around the bottom left of the currently navigated item
        local activated_shortcut = g.ActiveId ~= 0 and g.ActiveIdFromShortcut and g.ActiveId == g.LastItemData.ID

        local ref_rect = ImRect()
        if activated_shortcut and (bit32.band(window_type, ImGuiWindowFlags.Popup) ~= 0) then
            ImRect_Copy(ref_rect, g.LastItemData.NavRect)
        elseif window ~= nil then
            ImRect_Copy(ref_rect, ImGui.WindowRectRelToAbs(window, window.NavRectRel[g.NavLayer]))
        end

        -- Take account of upcoming scrolling (maybe set mouse pos should be done in EndFrame?)
        if window ~= nil and window.LastFrameActive ~= g.FrameCount and (window.ScrollTarget.x ~= FLT_MAX or window.ScrollTarget.y ~= FLT_MAX) then
            local next_scroll = CalcNextScrollFromScrollTargetAndClamp(window)
            ref_rect:Translate(window.Scroll - next_scroll)
        end

        local pos = ImVec2(ref_rect.Min.x + ImMin(g.Style.FramePadding.x * 4, ref_rect:GetWidth()), ref_rect.Max.y - ImMin(g.Style.FramePadding.y, ref_rect:GetHeight()))
        if window ~= nil then
            local viewport = window.Viewport
            if viewport then
                pos = ImClamp(pos, viewport.Pos, viewport.Pos + viewport.Size)
            end
        end

        return ImTrunc(pos) -- ImTrunc() is important because non-integer mouse position application in backend might be lossy and result in undesirable non-zero delta.
    end
end

--- @param axis ImGuiAxis
--- @return float
function ImGui.GetNavTweakPressedAmount(axis)
    local g = GImGui
    local repeat_delay, repeat_rate = ImGui.GetTypematicRepeatRate(ImGuiInputFlags.RepeatRateNavTweak)

    local key_less, key_more
    if g.NavInputSource == ImGuiInputSource.Gamepad then
        key_less = (axis == ImGuiAxis.X) and ImGuiKey.GamepadDpadLeft or ImGuiKey.GamepadDpadUp
        key_more = (axis == ImGuiAxis.X) and ImGuiKey.GamepadDpadRight or ImGuiKey.GamepadDpadDown
    else
        key_less = (axis == ImGuiAxis.X) and ImGuiKey.LeftArrow or ImGuiKey.UpArrow
        key_more = (axis == ImGuiAxis.X) and ImGuiKey.RightArrow or ImGuiKey.DownArrow
    end

    local amount = ImGui.GetKeyPressedAmount(key_more, repeat_delay, repeat_rate) - ImGui.GetKeyPressedAmount(key_less, repeat_delay, repeat_rate)

    if amount ~= 0.0 and ImGui.IsKeyDown(key_less) and ImGui.IsKeyDown(key_more) then -- Cancel when opposite directions are held, regardless of repeat phase
        amount = 0.0
    end

    return amount
end

do

local nav_gamepad_keys_to_change_source = { ImGuiKey.GamepadFaceRight, ImGuiKey.GamepadFaceLeft, ImGuiKey.GamepadFaceUp, ImGuiKey.GamepadFaceDown, ImGuiKey.GamepadDpadRight, ImGuiKey.GamepadDpadLeft, ImGuiKey.GamepadDpadUp, ImGuiKey.GamepadDpadDown }
local nav_keyboard_keys_to_change_source = { ImGuiKey.Space, ImGuiKey.Enter, ImGuiKey.Escape, ImGuiKey.RightArrow, ImGuiKey.LeftArrow, ImGuiKey.UpArrow, ImGuiKey.DownArrow }

--- @param focus_change_dir int
function ImGui.NavUpdateWindowingTarget(focus_change_dir)
    local g = GImGui
    IM_ASSERT(g.NavWindowingTarget)
    if bit32.band(g.NavWindowingTarget.Flags, ImGuiWindowFlags.Modal) ~= 0 then
        return
    end

    local i_current = ImGui.FindWindowFocusIndex(g.NavWindowingTarget)
    local window_target = ImGui.FindWindowNavFocusable(i_current + focus_change_dir, 0, focus_change_dir)
    if window_target == nil then
        window_target = ImGui.FindWindowNavFocusable((focus_change_dir < 0) and g.WindowsFocusOrder.Size or 1, i_current, focus_change_dir)
    end
    if window_target then -- Don't reset windowing target if there's a single window in the list
        g.NavWindowingTarget = window_target
        g.NavWindowingTargetAnim = window_target
        ImVec2_CopyV(g.NavWindowingAccumDeltaPos, 0.0, 0.0)
        ImVec2_CopyV(g.NavWindowingAccumDeltaSize, 0.0, 0.0)
    end
    g.NavWindowingToggleLayer = false
end

-- Apply focus and close overlay
--- @param apply_focus_window ImGuiWindow
function ImGui.NavUpdateWindowingApplyFocus(apply_focus_window)
    -- FIXME: Many actions here could be part of a higher-level/reused function. Why aren't they in FocusWindow() ?
    -- Investigate for each of them: ClearActiveID(), NavRestoreHighlightAfterMove(), NavRestoreLastChildNavWindow(), ClosePopupsOverWindow(), NavInitWindow()
    local g = GImGui
    if g.NavWindow == nil or apply_focus_window ~= g.NavWindow.RootWindow then
        local previous_viewport = g.NavWindow and g.NavWindow.Viewport or nil
        ImGui.ClearActiveID()
        ImGui.SetNavCursorVisibleAfterMove()
        ImGui.ClosePopupsOverWindow(apply_focus_window, false)
        ImGui.FocusWindow(apply_focus_window, ImGuiFocusRequestFlags.RestoreFocusedChild)
        IM_ASSERT(g.NavWindow ~= nil)
        apply_focus_window = g.NavWindow
        if apply_focus_window.NavLastIds[ImGuiNavLayer.Main] == 0 then -- FIXME: This is the equivalent of the 'if (g.NavId == 0) { NavInitWindow() }' in DockNodeUpdateTabBar().
            ImGui.NavInitWindow(apply_focus_window, false)
        end

        -- If the window has ONLY a menu layer (no main layer), select it directly
        -- Use NavLayersActiveMaskNext since windows didn't have a chance to be Begin()-ed on this frame,
        -- so Ctrl+Tab where the keys are only held for 1 frame will be able to use correct layers mask since
        -- the target window as already been previewed once.
        -- FIXME-NAV: This should be done in NavInit.. or in FocusWindow... However in both of those cases,
        -- we won't have a guarantee that windows has been visible before and therefore NavLayersActiveMask*
        -- won't be valid.
        if apply_focus_window.DC.NavLayersActiveMaskNext == bit32.lshift(1, ImGuiNavLayer.Menu) then
            g.NavLayer = ImGuiNavLayer.Menu
        end

        -- Request OS level focus
        if apply_focus_window.Viewport ~= previous_viewport and g.PlatformIO.Platform_SetWindowFocus then
            g.PlatformIO.Platform_SetWindowFocus(apply_focus_window.Viewport)
        end
    end
    g.NavWindowingTarget = nil
end

-- Windowing management mode
-- Keyboard: Ctrl+Tab (change focus/move/resize), Alt (toggle menu layer)
-- Gamepad:  Hold Menu/Square (change focus/move/resize), Tap Menu/Square (toggle menu layer)
function ImGui.NavUpdateWindowing()
    local g = GImGui
    local io = g.IO

    local apply_focus_window = nil
    local apply_toggle_layer = false

    local modal_window = ImGui.GetTopMostPopupModal()
    local allow_windowing = (modal_window == nil) -- FIXME: This prevent Ctrl+Tab from being usable with windows that are inside the Begin-stack of that modal.
    if not allow_windowing then
        g.NavWindowingTarget = nil
    end

    -- Fade out
    if g.NavWindowingTargetAnim and g.NavWindowingTarget == nil then
        g.NavWindowingHighlightAlpha = ImMax(g.NavWindowingHighlightAlpha - io.DeltaTime * 10.0, 0.0)
        if g.DimBgRatio <= 0.0 and g.NavWindowingHighlightAlpha <= 0.0 then
            g.NavWindowingTargetAnim = nil
        end
    end

    -- Start Ctrl+Tab or Square+L/R window selection
    -- (g.ConfigNavWindowingKeyNext/g.ConfigNavWindowingKeyPrev defaults are ImGuiMod_Ctrl|ImGuiKey.Tab and ImGuiMod_Ctrl|ImGuiMod_Shift|ImGuiKey.Tab)
    local owner_id = ImHashStr("##NavUpdateWindowing")
    local nav_gamepad_active = bit32.band(io.ConfigFlags, ImGuiConfigFlags.NavEnableGamepad) ~= 0 and bit32.band(io.BackendFlags, ImGuiBackendFlags.HasGamepad) ~= 0
    local nav_keyboard_active = bit32.band(io.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard) ~= 0
    local keyboard_next_window = allow_windowing and g.ConfigNavWindowingKeyNext ~= 0 and ImGui.Shortcut(g.ConfigNavWindowingKeyNext, bit32.bor(ImGuiInputFlags.Repeat, ImGuiInputFlags.RouteAlways), owner_id)
    local keyboard_prev_window = allow_windowing and g.ConfigNavWindowingKeyPrev ~= 0 and ImGui.Shortcut(g.ConfigNavWindowingKeyPrev, bit32.bor(ImGuiInputFlags.Repeat, ImGuiInputFlags.RouteAlways), owner_id)
    local start_toggling_with_gamepad = nav_gamepad_active and g.NavWindowingTarget == nil and ImGui.Shortcut(ImGuiKey.NavGamepadMenu, ImGuiInputFlags.RouteAlways, owner_id)
    local start_windowing_with_gamepad = allow_windowing and start_toggling_with_gamepad
    local start_windowing_with_keyboard = allow_windowing and g.NavWindowingTarget == nil and (keyboard_next_window or keyboard_prev_window) -- Note: enabled even without NavEnableKeyboard!
    local just_started_windowing_from_null_focus = false
    if start_toggling_with_gamepad then
        g.NavWindowingToggleLayer = true -- Gamepad starts toggling layer
        g.NavWindowingToggleKey = ImGuiKey.NavGamepadMenu
        g.NavWindowingInputSource = ImGuiInputSource.Gamepad
        g.NavInputSource = ImGuiInputSource.Gamepad
    end
    if start_windowing_with_gamepad or start_windowing_with_keyboard then
        local window = (g.NavWindow and ImGui.IsWindowNavFocusable(g.NavWindow)) and g.NavWindow or ImGui.FindWindowNavFocusable(g.WindowsFocusOrder.Size, 0, -1)
        if window then
            if start_windowing_with_keyboard or g.ConfigNavWindowingWithGamepad then
                g.NavWindowingTarget = window.RootWindow
                g.NavWindowingTargetAnim = window.RootWindow -- Current location
            end
            g.NavWindowingTimer = 0.0
            g.NavWindowingHighlightAlpha = 0.0
            ImVec2_CopyV(g.NavWindowingAccumDeltaPos, 0.0, 0.0)
            ImVec2_CopyV(g.NavWindowingAccumDeltaSize, 0.0, 0.0)
            g.NavWindowingInputSource = start_windowing_with_keyboard and ImGuiInputSource.Keyboard or ImGuiInputSource.Gamepad
            g.NavInputSource = g.NavWindowingInputSource
            if g.NavWindow == nil then
                just_started_windowing_from_null_focus = true
            end

            -- Manually register ownership of our mods. Using a global route in the Shortcut() calls instead would probably be correct but may have more side-effects.
            if keyboard_next_window or keyboard_prev_window then
                ImGui.SetKeyOwnersForKeyChord(bit32.band(bit32.bor(g.ConfigNavWindowingKeyNext, g.ConfigNavWindowingKeyPrev), ImGuiMod_Mask_), owner_id)
            end
        end
    end

    -- Gamepad update
    if (g.NavWindowingTarget or g.NavWindowingToggleLayer) and g.NavWindowingInputSource == ImGuiInputSource.Gamepad then
        if g.NavWindowingTarget ~= nil then
            -- Highlight only appears after a brief time holding the button, so that a fast tap on ImGuiKey.NavGamepadMenu (to toggle NavLayer) doesn't add visual noise
            -- However inputs are accepted immediately, so you press ImGuiKey.NavGamepadMenu + L1/R1 fast.
            g.NavWindowingTimer = g.NavWindowingTimer + io.DeltaTime
            g.NavWindowingHighlightAlpha = ImMax(g.NavWindowingHighlightAlpha, ImSaturate((g.NavWindowingTimer - NAV_WINDOWING_HIGHLIGHT_DELAY) / 0.05))

            -- Select window to focus
            local focus_change_dir = (ImGui.IsKeyPressedEx(ImGuiKey.GamepadL1, ImGuiInputFlags.None, ImGuiKeyOwner_Any) and 1 or 0) - (ImGui.IsKeyPressedEx(ImGuiKey.GamepadR1, ImGuiInputFlags.None, ImGuiKeyOwner_Any) and 1 or 0)
            if focus_change_dir ~= 0 and not just_started_windowing_from_null_focus then
                ImGui.NavUpdateWindowingTarget(focus_change_dir)
                g.NavWindowingHighlightAlpha = 1.0
            end
        end

        -- Single press toggles NavLayer, long press with L/R apply actual focus on release (until then the window was merely rendered top-most)
        if not ImGui.IsKeyDown(ImGuiKey.NavGamepadMenu) then
            g.NavWindowingToggleLayer = g.NavWindowingToggleLayer and (g.NavWindowingHighlightAlpha < 1.0) -- Once button was held long enough we don't consider it a tap-to-toggle-layer press anymore.
            if g.NavWindowingToggleLayer and g.NavWindow then
                apply_toggle_layer = true
            elseif not g.NavWindowingToggleLayer then
                apply_focus_window = g.NavWindowingTarget
            end
            g.NavWindowingTarget = nil
            g.NavWindowingToggleLayer = false
        end
    end

    -- Keyboard: Focus
    if g.NavWindowingTarget and g.NavWindowingInputSource == ImGuiInputSource.Keyboard then
        -- Visuals only appears after a brief time after pressing TAB the first time, so that a fast Ctrl+Tab doesn't add visual noise
        local shared_mods = bit32.band(
            bit32.band((g.ConfigNavWindowingKeyNext ~= 0) and g.ConfigNavWindowingKeyNext or ImGuiMod_Mask_, (g.ConfigNavWindowingKeyPrev ~= 0) and g.ConfigNavWindowingKeyPrev or ImGuiMod_Mask_),
            ImGuiMod_Mask_)
        IM_ASSERT(shared_mods ~= 0) -- Next/Prev shortcut currently needs a shared modifier to "hold", otherwise Prev actions would keep cycling between two windows.
        g.NavWindowingTimer = g.NavWindowingTimer + io.DeltaTime
        g.NavWindowingHighlightAlpha = ImMax(g.NavWindowingHighlightAlpha, ImSaturate((g.NavWindowingTimer - NAV_WINDOWING_HIGHLIGHT_DELAY) / 0.05)) -- 1.0f
        if (keyboard_next_window or keyboard_prev_window) and not just_started_windowing_from_null_focus then
            ImGui.NavUpdateWindowingTarget(keyboard_next_window and -1 or 1)
        elseif bit32.band(io.KeyMods, shared_mods) ~= shared_mods then
            apply_focus_window = g.NavWindowingTarget
        end
    end

    -- Keyboard: Press and Release Alt to toggle menu layer
    local windowing_toggle_keys = { ImGuiKey.LeftAlt, ImGuiKey.RightAlt }
    local windowing_toggle_layer_start = false
    if g.NavWindow and bit32.band(g.NavWindow.Flags, ImGuiWindowFlags.NoNavInputs) == 0 then
        for _, windowing_toggle_key in ipairs(windowing_toggle_keys) do
            if nav_keyboard_active and ImGui.IsKeyPressedEx(windowing_toggle_key, ImGuiInputFlags.None, ImGuiKeyOwner_NoOwner) then
                windowing_toggle_layer_start = true
                g.NavWindowingToggleLayer = true
                g.NavWindowingToggleKey = windowing_toggle_key
                g.NavWindowingInputSource = ImGuiInputSource.Keyboard
                g.NavInputSource = ImGuiInputSource.Keyboard
                break
            end
        end
    end
    if g.NavWindowingToggleLayer and g.NavWindowingInputSource == ImGuiInputSource.Keyboard then
        -- We cancel toggling nav layer when any text has been typed (generally while holding Alt). (See #370)
        -- We cancel toggling nav layer when other modifiers are pressed. (See #4439)
        -- - AltGR is Alt+Ctrl on some layout but we can't reliably detect it (not all backends/systems/layout emit it as Alt+Ctrl).
        -- We cancel toggling nav layer if an owner has claimed the key.
        if io.InputQueueCharacters.Size > 0 or io.KeyCtrl or io.KeyShift or io.KeySuper then
            g.NavWindowingToggleLayer = false
        elseif windowing_toggle_layer_start == false and g.LastKeyboardKeyPressTime == g.Time then
            g.NavWindowingToggleLayer = false
        elseif ImGui.TestKeyOwner(g.NavWindowingToggleKey, ImGuiKeyOwner_NoOwner) == false or ImGui.TestKeyOwner(ImGuiMod_Alt, ImGuiKeyOwner_NoOwner) == false then
            g.NavWindowingToggleLayer = false
        end

        -- Apply layer toggle on Alt release
        -- Important: as before version <18314 we lacked an explicit IO event for focus gain/loss, we also compare mouse validity to detect old backends clearing mouse pos on focus loss.
        if ImGui.IsKeyReleased(g.NavWindowingToggleKey) and g.NavWindowingToggleLayer then
            if g.ActiveId == 0 or g.ActiveIdAllowOverlap then
                if ImGui.IsMousePosValid(io.MousePos) == ImGui.IsMousePosValid(io.MousePosPrev) then
                    apply_toggle_layer = true
                end
            end
        end
        if not ImGui.IsKeyDown(g.NavWindowingToggleKey) then
            g.NavWindowingToggleLayer = false
        end
    end

    -- Move window
    if g.NavWindowingTarget and bit32.band(g.NavWindowingTarget.Flags, ImGuiWindowFlags.NoMove) == 0 then
        local nav_move_dir
        if g.NavInputSource == ImGuiInputSource.Keyboard and not io.KeyShift then
            nav_move_dir = ImGui.GetKeyMagnitude2d(ImGuiKey.LeftArrow, ImGuiKey.RightArrow, ImGuiKey.UpArrow, ImGuiKey.DownArrow)
        end
        if g.NavInputSource == ImGuiInputSource.Gamepad then
            nav_move_dir = ImGui.GetKeyMagnitude2d(ImGuiKey.GamepadLStickLeft, ImGuiKey.GamepadLStickRight, ImGuiKey.GamepadLStickUp, ImGuiKey.GamepadLStickDown)
        end
        if nav_move_dir and (nav_move_dir.x ~= 0.0 or nav_move_dir.y ~= 0.0) then
            local NAV_MOVE_SPEED = 800.0
            local move_step = NAV_MOVE_SPEED * io.DeltaTime * ImGui.GetScale()
            ImVec2_Copy(g.NavWindowingAccumDeltaPos, g.NavWindowingAccumDeltaPos + nav_move_dir * move_step)
            g.NavHighlightItemUnderNav = true
            local accum_floored = ImTrunc(g.NavWindowingAccumDeltaPos)
            if accum_floored.x ~= 0.0 or accum_floored.y ~= 0.0 then
                local moving_window = g.NavWindowingTarget.RootWindowDockTree
                ImGui.SetWindowPos(moving_window, moving_window.Pos + accum_floored, ImGuiCond.Always)
                ImVec2_Copy(g.NavWindowingAccumDeltaPos, g.NavWindowingAccumDeltaPos - accum_floored)
            end
        end
    end

    -- Apply final focus
    if apply_focus_window then
        ImGui.NavUpdateWindowingApplyFocus(apply_focus_window)
    end

    -- Apply menu/layer toggle
    if apply_toggle_layer and g.NavWindow then
        ImGui.ClearActiveID()

        -- Move to parent menu if necessary
        local new_nav_window = g.NavWindow
        while new_nav_window.ParentWindow
            and bit32.band(new_nav_window.DC.NavLayersActiveMask, bit32.lshift(1, ImGuiNavLayer.Menu)) == 0
            and bit32.band(new_nav_window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0
            and bit32.band(new_nav_window.Flags, bit32.bor(ImGuiWindowFlags.Popup, ImGuiWindowFlags.ChildMenu)) == 0 do
            new_nav_window = new_nav_window.ParentWindow
        end
        if new_nav_window ~= g.NavWindow then
            local old_nav_window = g.NavWindow
            ImGui.FocusWindow(new_nav_window)
            new_nav_window.NavLastChildNavWindow = old_nav_window
        end

        -- Toggle layer
        local new_nav_layer = (bit32.band(g.NavWindow.DC.NavLayersActiveMask, bit32.lshift(1, ImGuiNavLayer.Menu)) ~= 0) and bit32.bxor(g.NavLayer, 1) or ImGuiNavLayer.Main
        if new_nav_layer ~= g.NavLayer then
            -- Reinitialize navigation when entering menu bar with the Alt key (FIXME: could be a properly of the layer?)
            local preserve_layer_1_nav_id = (new_nav_window.DockNodeAsHost ~= nil)
            if new_nav_layer == ImGuiNavLayer.Menu and not preserve_layer_1_nav_id then
                g.NavWindow.NavLastIds[new_nav_layer] = 0
            end
            ImGui.NavRestoreLayer(new_nav_layer)
            ImGui.SetNavCursorVisibleAfterMove()
        end
    end
end

function ImGui.NavUpdateContextMenuRequest()
    local g = GImGui
    local io = g.IO
    g.NavOpenContextMenuItemId = 0
    g.NavOpenContextMenuWindowId = 0
    local nav_keyboard_active = bit32.band(io.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard) ~= 0
    local nav_gamepad_active = bit32.band(io.ConfigFlags, ImGuiConfigFlags.NavEnableGamepad) ~= 0
    if (not nav_keyboard_active and not nav_gamepad_active) or g.NavWindow == nil then
        return
    end

    local request = false
    request = request or (nav_keyboard_active and (ImGui.IsKeyReleased(ImGuiKey.Menu, ImGuiKeyOwner_NoOwner) or (ImGui.IsKeyPressedEx(ImGuiKey.F10, ImGuiInputFlags.None, ImGuiKeyOwner_NoOwner) and io.KeyMods == ImGuiMod_Shift)))
    request = request or (nav_gamepad_active and ImGui.IsKeyPressedEx(ImGuiKey.NavGamepadContextMenu, ImGuiInputFlags.None, ImGuiKeyOwner_NoOwner))
    if not request then
        return
    end

    g.NavOpenContextMenuItemId = g.NavId
    g.NavOpenContextMenuWindowId = g.NavWindow.ID

    -- Allow triggering for Begin()..BeginPopupContextItem(). A possible alternative would be to use g.NavLayer == ImGuiNavLayer.Menu.
    if g.NavId == g.NavWindow:GetID("#CLOSE") or g.NavId == g.NavWindow:GetID("#COLLAPSE") then
        g.NavOpenContextMenuItemId = g.NavWindow.MoveId
    end

    g.NavInputSource = ImGuiInputSource.Keyboard
    ImGui.SetNavCursorVisibleAfterMove()
end

-- FIXME: ScoringRect is not set
--- @param move_dir     ImGuiDir
--- @param clip_dir     ImGuiDir
--- @param move_flags   ImGuiNavMoveFlags
--- @param scroll_flags ImGuiScrollFlags
function ImGui.NavMoveRequestSubmit(move_dir, clip_dir, move_flags, scroll_flags)
    local g = GImGui
    IM_ASSERT(g.NavWindow ~= nil)
    -- IMGUI_DEBUG_LOG_NAV("[nav] NavMoveRequestSubmit: dir %c, window \"%s\"\n", "-WENS"[move_dir + 1], g.NavWindow->Name)

    if bit32.band(move_flags, ImGuiNavMoveFlags.IsTabbing) ~= 0 then
        move_flags = bit32.bor(move_flags, ImGuiNavMoveFlags.AllowCurrentNavId)
    end
    g.NavMoveSubmitted = true; g.NavMoveScoringItems = true
    g.NavMoveDir = move_dir
    g.NavMoveDirForDebug = move_dir
    g.NavMoveClipDir = clip_dir
    g.NavMoveFlags = move_flags
    g.NavMoveScrollFlags = scroll_flags
    g.NavMoveForwardToNextFrame = false
    g.NavMoveKeyMods = (bit32.band(move_flags, ImGuiNavMoveFlags.FocusApi) ~= 0) and 0 or g.IO.KeyMods
    g.NavMoveResultLocal:Clear()
    g.NavMoveResultLocalVisible:Clear()
    g.NavMoveResultOther:Clear()
    g.NavTabbingCounter = 0
    g.NavTabbingResultFirst:Clear()
    ImGui.NavUpdateAnyRequestFlag()
end

-- Bias scoring rect ahead of scoring + update preferred pos (if missing) using source position
--- @param r                 ImRect
--- @param preferred_pos_rel ImVec2
--- @param move_dir          ImGuiDir
--- @param move_flags        ImGuiNavMoveFlags
function ImGui.NavBiasScoringRect(r, preferred_pos_rel, move_dir, move_flags)
    -- Bias initial rect
    local g = GImGui
    local rel_to_abs_offset = g.NavWindow.DC.CursorStartPos

    -- Initialize bias on departure if we don't have any. So mouse-click + arrow will record bias.
    -- - We default to L/U bias, so moving down from a large source item into several columns will land on left-most column.
    -- - But each successful move sets new bias on one axis, only cleared when using mouse.
    if bit32.band(move_flags, ImGuiNavMoveFlags.Forwarded) == 0 then
        if preferred_pos_rel.x == FLT_MAX then
            preferred_pos_rel.x = ImMin(r.Min.x + 1.0, r.Max.x) - rel_to_abs_offset.x
        end
        if preferred_pos_rel.y == FLT_MAX then
            preferred_pos_rel.y = r:GetCenter().y - rel_to_abs_offset.y
        end
    end

    -- Apply general bias on the other axis
    if (move_dir == ImGuiDir.Up or move_dir == ImGuiDir.Down) and preferred_pos_rel.x ~= FLT_MAX then
        local new_x = preferred_pos_rel.x + rel_to_abs_offset.x
        r.Min.x = new_x; r.Max.x = new_x
    elseif (move_dir == ImGuiDir.Left or move_dir == ImGuiDir.Right) and preferred_pos_rel.y ~= FLT_MAX then
        local new_y = preferred_pos_rel.y + rel_to_abs_offset.y
        r.Min.y = new_y; r.Max.y = new_y
    end
end

-- Handle PageUp/PageDown/Home/End keys
-- Called from NavUpdateCreateMoveRequest() which will use our output to create a move request
-- FIXME-NAV: This doesn't work properly with NavFlattened siblings as we use NavWindow rectangle for reference
-- FIXME-NAV: how to get Home/End to aim at the beginning/end of a 2D grid?
--- @return float
function ImGui.NavUpdatePageUpPageDown()
    local g = GImGui
    local window = g.NavWindow
    if bit32.band(window.Flags, ImGuiWindowFlags.NoNavInputs) ~= 0 or g.NavWindowingTarget ~= nil then
        return 0.0
    end

    local page_up_held = ImGui.IsKeyDown(ImGuiKey.PageUp, ImGuiKeyOwner_NoOwner)
    local page_down_held = ImGui.IsKeyDown(ImGuiKey.PageDown, ImGuiKeyOwner_NoOwner)
    local home_pressed = ImGui.IsKeyPressedEx(ImGuiKey.Home, ImGuiInputFlags.Repeat, ImGuiKeyOwner_NoOwner)
    local end_pressed = ImGui.IsKeyPressedEx(ImGuiKey.End, ImGuiInputFlags.Repeat, ImGuiKeyOwner_NoOwner)
    if page_up_held == page_down_held and home_pressed == end_pressed then -- Proceed if either (not both) are pressed, otherwise early out
        return 0.0
    end

    if g.NavLayer ~= ImGuiNavLayer.Main then
        ImGui.NavRestoreLayer(ImGuiNavLayer.Main)
    end

    if bit32.band(window.DC.NavLayersActiveMask, bit32.lshift(1, ImGuiNavLayer.Main)) == 0 and window.DC.NavWindowHasScrollY then
        -- Fallback manual-scroll when window has no navigable item
        if ImGui.IsKeyPressedEx(ImGuiKey.PageUp, ImGuiInputFlags.Repeat, ImGuiKeyOwner_NoOwner) then
            ImGui.SetScrollY(window, window.Scroll.y - window.InnerRect:GetHeight())
        elseif ImGui.IsKeyPressedEx(ImGuiKey.PageDown, ImGuiInputFlags.Repeat, ImGuiKeyOwner_NoOwner) then
            ImGui.SetScrollY(window, window.Scroll.y + window.InnerRect:GetHeight())
        elseif home_pressed then
            ImGui.SetScrollY(window, 0.0)
        elseif end_pressed then
            ImGui.SetScrollY(window, window.ScrollMax.y)
        end
    else
        local nav_rect_rel = window.NavRectRel[g.NavLayer]
        local page_offset_y = ImMax(0.0, window.InnerRect:GetHeight() - window.FontRefSize * 1.0 + nav_rect_rel:GetHeight())
        local nav_scoring_rect_offset_y = 0.0
        if ImGui.IsKeyPressedEx(ImGuiKey.PageUp, ImGuiInputFlags.Repeat, ImGuiKeyOwner_NoOwner) then
            nav_scoring_rect_offset_y = -page_offset_y
            g.NavMoveDir = ImGuiDir.Down -- Because our scoring rect is offset up, we request the down direction (so we can always land on the last item)
            g.NavMoveClipDir = ImGuiDir.Up
            g.NavMoveFlags = bit32.bor(ImGuiNavMoveFlags.AllowCurrentNavId, ImGuiNavMoveFlags.IsPageMove) -- ImGuiNavMoveFlags.AlsoScoreVisibleSet may be added later
        elseif ImGui.IsKeyPressedEx(ImGuiKey.PageDown, ImGuiInputFlags.Repeat, ImGuiKeyOwner_NoOwner) then
            nav_scoring_rect_offset_y = page_offset_y
            g.NavMoveDir = ImGuiDir.Up -- Because our scoring rect is offset down, we request the up direction (so we can always land on the last item)
            g.NavMoveClipDir = ImGuiDir.Down
            g.NavMoveFlags = bit32.bor(ImGuiNavMoveFlags.AllowCurrentNavId, ImGuiNavMoveFlags.IsPageMove) -- ImGuiNavMoveFlags.AlsoScoreVisibleSet may be added later
        elseif home_pressed then
            -- FIXME-NAV: handling of Home/End is assuming that the top/bottom most item will be visible with Scroll.y == 0/ScrollMax.y
            -- Scrolling will be handled via the ImGuiNavMoveFlags.ScrollToEdgeY flag, we don't scroll immediately to avoid scrolling happening before nav result.
            -- Preserve current horizontal position if we have any.
            nav_rect_rel.Min.y = 0.0; nav_rect_rel.Max.y = 0.0
            if nav_rect_rel:IsInverted() then
                nav_rect_rel.Min.x = 0.0; nav_rect_rel.Max.x = 0.0
            end
            g.NavMoveDir = ImGuiDir.Down
            g.NavMoveFlags = bit32.bor(ImGuiNavMoveFlags.AllowCurrentNavId, ImGuiNavMoveFlags.ScrollToEdgeY)
            -- FIXME-NAV: MoveClipDir left to _None, intentional?
        elseif end_pressed then
            nav_rect_rel.Min.y = window.ContentSize.y; nav_rect_rel.Max.y = window.ContentSize.y
            if nav_rect_rel:IsInverted() then
                nav_rect_rel.Min.x = 0.0; nav_rect_rel.Max.x = 0.0
            end
            g.NavMoveDir = ImGuiDir.Up
            g.NavMoveFlags = bit32.bor(ImGuiNavMoveFlags.AllowCurrentNavId, ImGuiNavMoveFlags.ScrollToEdgeY)
            -- FIXME-NAV: MoveClipDir left to _None, intentional?
        end
        return nav_scoring_rect_offset_y
    end
    return 0.0
end

function ImGui.NavUpdateCreateMoveRequest()
    local g = GImGui
    local io = g.IO
    local window = g.NavWindow
    local nav_gamepad_active = bit32.band(io.ConfigFlags, ImGuiConfigFlags.NavEnableGamepad) ~= 0 and bit32.band(io.BackendFlags, ImGuiBackendFlags.HasGamepad) ~= 0
    local nav_keyboard_active = bit32.band(io.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard) ~= 0

    if g.NavMoveForwardToNextFrame and window ~= nil then
        -- Forwarding previous request (which has been modified, e.g. wrap around menus rewrite the requests with a starting rectangle at the other side of the window)
        -- (preserve most state, which were already set by the NavMoveRequestForward() function)
        IM_ASSERT(g.NavMoveDir ~= ImGuiDir.None and g.NavMoveClipDir ~= ImGuiDir.None)
        IM_ASSERT(bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.Forwarded) ~= 0)
        -- IMGUI_DEBUG_LOG_NAV("[nav] NavMoveRequestForward %d\n", g.NavMoveDir)
    else
        -- Initiate directional inputs request
        g.NavMoveDir = ImGuiDir.None
        g.NavMoveFlags = ImGuiNavMoveFlags.None
        g.NavMoveScrollFlags = ImGuiScrollFlags.None
        if window and not g.NavWindowingTarget and bit32.band(window.Flags, ImGuiWindowFlags.NoNavInputs) == 0 then
            local repeat_mode = bit32.bor(ImGuiInputFlags.Repeat, ImGuiInputFlags.RepeatRateNavMove)
            if not ImGui.IsActiveIdUsingNavDir(ImGuiDir.Left)  and ((nav_gamepad_active and ImGui.IsKeyPressedEx(ImGuiKey.GamepadDpadLeft,  repeat_mode, ImGuiKeyOwner_NoOwner)) or (nav_keyboard_active and ImGui.IsKeyPressedEx(ImGuiKey.LeftArrow,  repeat_mode, ImGuiKeyOwner_NoOwner))) then g.NavMoveDir = ImGuiDir.Left end
            if not ImGui.IsActiveIdUsingNavDir(ImGuiDir.Right) and ((nav_gamepad_active and ImGui.IsKeyPressedEx(ImGuiKey.GamepadDpadRight, repeat_mode, ImGuiKeyOwner_NoOwner)) or (nav_keyboard_active and ImGui.IsKeyPressedEx(ImGuiKey.RightArrow, repeat_mode, ImGuiKeyOwner_NoOwner))) then g.NavMoveDir = ImGuiDir.Right end
            if not ImGui.IsActiveIdUsingNavDir(ImGuiDir.Up)    and ((nav_gamepad_active and ImGui.IsKeyPressedEx(ImGuiKey.GamepadDpadUp,    repeat_mode, ImGuiKeyOwner_NoOwner)) or (nav_keyboard_active and ImGui.IsKeyPressedEx(ImGuiKey.UpArrow,    repeat_mode, ImGuiKeyOwner_NoOwner))) then g.NavMoveDir = ImGuiDir.Up end
            if not ImGui.IsActiveIdUsingNavDir(ImGuiDir.Down)  and ((nav_gamepad_active and ImGui.IsKeyPressedEx(ImGuiKey.GamepadDpadDown,  repeat_mode, ImGuiKeyOwner_NoOwner)) or (nav_keyboard_active and ImGui.IsKeyPressedEx(ImGuiKey.DownArrow,  repeat_mode, ImGuiKeyOwner_NoOwner))) then g.NavMoveDir = ImGuiDir.Down end
        end
        g.NavMoveClipDir = g.NavMoveDir
        ImRect_Copy(g.NavScoringNoClipRect, ImRect(FLT_MAX, FLT_MAX, -FLT_MAX, -FLT_MAX))
    end

    -- Update PageUp/PageDown/Home/End scroll
    -- FIXME-NAV: Consider enabling those keys even without the master ImGuiConfigFlags.NavEnableKeyboard flag?
    local scoring_page_offset_y = 0.0
    if window and g.NavMoveDir == ImGuiDir.None and nav_keyboard_active then
        scoring_page_offset_y = ImGui.NavUpdatePageUpPageDown()
    end

    -- Submit
    g.NavMoveForwardToNextFrame = false
    if g.NavMoveDir ~= ImGuiDir.None then
        ImGui.NavMoveRequestSubmit(g.NavMoveDir, g.NavMoveClipDir, g.NavMoveFlags, g.NavMoveScrollFlags)
    end

    -- Moving with no reference triggers an init request (will be used as a fallback if the direction fails to find a match)
    if g.NavMoveSubmitted and g.NavId == 0 then
        -- IMGUI_DEBUG_LOG_NAV("[nav] NavInitRequest: from move, window \"%s\", layer=%d\n", window ? window->Name : "<NULL>", g.NavLayer)
        g.NavInitRequest = true; g.NavInitRequestFromMove = true
        g.NavInitResult.ID = 0
        if g.IO.ConfigNavCursorVisibleAuto then -- NO check for _NoNavInputs here as we assume MoveRequests cannot be created.
            g.NavCursorVisible = true
        end
    end

    -- When using gamepad, we project the reference nav bounding box into window visible area.
    -- This is to allow resuming navigation inside the visible area after doing a large amount of scrolling,
    -- since with gamepad all movements are relative (can't focus a visible object like we can with the mouse).
    if g.NavMoveSubmitted and g.NavInputSource == ImGuiInputSource.Gamepad and g.NavLayer == ImGuiNavLayer.Main and window ~= nil then -- and (g.NavMoveFlags & ImGuiNavMoveFlags_Forwarded))
        local clamp_x = bit32.band(g.NavMoveFlags, bit32.bor(ImGuiNavMoveFlags.LoopX, ImGuiNavMoveFlags.WrapX)) == 0
        local clamp_y = bit32.band(g.NavMoveFlags, bit32.bor(ImGuiNavMoveFlags.LoopY, ImGuiNavMoveFlags.WrapY)) == 0
        local inner_rect_rel = ImGui.WindowRectAbsToRel(window, ImRect(ImVec2(window.InnerRect.Min.x - 1, window.InnerRect.Min.y - 1), ImVec2(window.InnerRect.Max.x + 1, window.InnerRect.Max.y + 1)))

        -- Take account of changing scroll to handle triggering a new move request on a scrolling frame. (#6171)
        -- Otherwise 'inner_rect_rel' would be off on the move result frame.
        local next_scroll = CalcNextScrollFromScrollTargetAndClamp(window)
        inner_rect_rel:Translate(ImVec2(next_scroll.x - window.Scroll.x, next_scroll.y - window.Scroll.y))

        if (clamp_x or clamp_y) and not inner_rect_rel:Contains(window.NavRectRel[g.NavLayer]) then
            -- IMGUI_DEBUG_LOG_NAV("[nav] NavMoveRequest: clamp NavRectRel for gamepad move\n")
            local pad_x = ImMin(inner_rect_rel:GetWidth(), window.FontRefSize * 0.5)
            local pad_y = ImMin(inner_rect_rel:GetHeight(), window.FontRefSize * 0.5) -- Terrible approximation for the intent of starting navigation from first fully visible item
            inner_rect_rel.Min.x = clamp_x and (inner_rect_rel.Min.x + pad_x) or -FLT_MAX
            inner_rect_rel.Max.x = clamp_x and (inner_rect_rel.Max.x - pad_x) or FLT_MAX
            inner_rect_rel.Min.y = clamp_y and (inner_rect_rel.Min.y + pad_y) or -FLT_MAX
            inner_rect_rel.Max.y = clamp_y and (inner_rect_rel.Max.y - pad_y) or FLT_MAX
            window.NavRectRel[g.NavLayer]:ClipWithFull(inner_rect_rel)
            g.NavId = 0
        end
    end

    -- Prepare scoring rectangle.
    -- For scoring we use a single segment on the left side our current item bounding box (not touching the edge to avoid box overlap with zero-spaced items)
    local scoring_rect = ImRect()
    if window ~= nil then
        local nav_rect_rel = ImRect()
        if not window.NavRectRel[g.NavLayer]:IsInverted() then
            ImRect_Copy(nav_rect_rel, window.NavRectRel[g.NavLayer])
        end
        scoring_rect = ImGui.WindowRectRelToAbs(window, nav_rect_rel)

        if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.IsPageMove) ~= 0 then
            -- When we start from a visible location, score visible items and prioritize this result.
            if window.InnerRect:Contains(scoring_rect) then
                g.NavMoveFlags = bit32.bor(g.NavMoveFlags, ImGuiNavMoveFlags.AlsoScoreVisibleSet)
            end
            ImRect_Copy(g.NavScoringNoClipRect, scoring_rect)
            scoring_rect:TranslateY(scoring_page_offset_y)
            g.NavScoringNoClipRect:Add(scoring_rect)
        end

        -- ImGui.GetForegroundDrawList():AddRectFilled(scoring_rect.Min - ImVec2(1, 1), scoring_rect.Max + ImVec2(1, 1), IM_COL32(255, 100, 0, 80)) -- [DEBUG] Pre-bias
        if g.NavMoveSubmitted then
            ImGui.NavBiasScoringRect(scoring_rect, window.RootWindowForNav.NavPreferredScoringPosRel[g.NavLayer], g.NavMoveDir, g.NavMoveFlags)
        end
        IM_ASSERT(not scoring_rect:IsInverted()) -- Ensure we have a non-inverted bounding box here will allow us to remove extraneous ImFabs() calls in NavScoreItem().
        -- ImGui.GetForegroundDrawList():AddRectFilled(scoring_rect.Min - ImVec2(1, 1), scoring_rect.Max + ImVec2(1, 1), IM_COL32(255, 100, 0, 80)) -- [DEBUG] Post-bias
        -- if not g.NavScoringNoClipRect:IsInverted() then ImGui.GetForegroundDrawList():AddRectFilled(g.NavScoringNoClipRect.Min, g.NavScoringNoClipRect.Max, IM_COL32(100, 255, 0, 80)) end -- [DEBUG]
    end
    ImRect_Copy(g.NavScoringRect, scoring_rect)
    -- g.NavScoringNoClipRect:Add(scoring_rect)
end

function ImGui.NavUpdateCreateTabbingRequest()
    local g = GImGui
    local window = g.NavWindow
    IM_ASSERT(g.NavMoveDir == ImGuiDir.None)
    if window == nil or g.NavWindowingTarget ~= nil or bit32.band(window.Flags, ImGuiWindowFlags.NoNavInputs) ~= 0 or not g.ConfigNavEnableTabbing then
        return
    end

    local tab_pressed = ImGui.IsKeyPressedEx(ImGuiKey.Tab, ImGuiInputFlags.Repeat, ImGuiKeyOwner_NoOwner) and not g.IO.KeyCtrl and not g.IO.KeyAlt
    if not tab_pressed then
        return
    end

    -- Initiate tabbing request
    -- (this is ALWAYS ENABLED, regardless of ImGuiConfigFlags.NavEnableKeyboard flag!)
    -- See NavProcessItemForTabbingRequest() for a description of the various forward/backward tabbing cases with and without wrapping.
    local nav_keyboard_active = bit32.band(g.IO.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard) ~= 0
    if nav_keyboard_active then
        g.NavTabbingDir = g.IO.KeyShift and -1 or ((g.NavCursorVisible == false and g.ActiveId == 0) and 0 or 1)
    else
        g.NavTabbingDir = g.IO.KeyShift and -1 or ((g.ActiveId == 0) and 0 or 1)
    end
    local move_flags = bit32.bor(ImGuiNavMoveFlags.IsTabbing, ImGuiNavMoveFlags.Activate)
    local scroll_flags = window.Appearing and bit32.bor(ImGuiScrollFlags.KeepVisibleEdgeX, ImGuiScrollFlags.AlwaysCenterY) or bit32.bor(ImGuiScrollFlags.KeepVisibleEdgeX, ImGuiScrollFlags.KeepVisibleEdgeY)
    local clip_dir = (g.NavTabbingDir < 0) and ImGuiDir.Up or ImGuiDir.Down
    ImGui.NavMoveRequestSubmit(ImGuiDir.None, clip_dir, move_flags, scroll_flags) -- FIXME-NAV: Once we refactor tabbing, add LegacyApi flag to not activate non-inputable.
    g.NavTabbingCounter = -1
end

function ImGui.NavUpdate()
    local g = GImGui
    local io = g.IO

    io.WantSetMousePos = false
    -- if g.NavScoringDebugCount > 0 then IMGUI_DEBUG_LOG_NAV("[nav] NavScoringDebugCount %d for '%s' layer %d (Init:%d, Move:%d)\n", g.NavScoringDebugCount, g.NavWindow ? g.NavWindow->Name : "NULL", g.NavLayer, g.NavInitRequest || g.NavInitResultId != 0, g.NavMoveRequest) end

    -- Set input source based on which keys are last pressed (as some features differs when used with Gamepad vs Keyboard)
    -- FIXME-NAV: Now that keys are separated maybe we can get rid of NavInputSource?
    local nav_gamepad_active = bit32.band(io.ConfigFlags, ImGuiConfigFlags.NavEnableGamepad) ~= 0 and bit32.band(io.BackendFlags, ImGuiBackendFlags.HasGamepad) ~= 0
    if nav_gamepad_active and g.NavInputSource ~= ImGuiInputSource.Gamepad then
        for _, key in ipairs(nav_gamepad_keys_to_change_source) do
            if ImGui.IsKeyDown(key) then
                g.NavInputSource = ImGuiInputSource.Gamepad
            end
        end
    end

    local nav_keyboard_active = bit32.band(io.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard) ~= 0
    if nav_keyboard_active and g.NavInputSource ~= ImGuiInputSource.Keyboard then
        for _, key in ipairs(nav_keyboard_keys_to_change_source) do
            if ImGui.IsKeyDown(key) then
                g.NavInputSource = ImGuiInputSource.Keyboard
            end
        end
    end

    -- Process navigation init request (select first/default focus)
    g.NavJustMovedToId = 0
    g.NavJustMovedToFocusScopeId = 0
    g.NavJustMovedFromFocusScopeId = 0
    if g.NavInitResult.ID ~= 0 then
        ImGui.NavInitRequestApplyResult()
    end
    g.NavInitRequest = false
    g.NavInitRequestFromMove = false
    g.NavInitResult.ID = 0

    -- Process navigation move request
    if g.NavMoveSubmitted then
        ImGui.NavMoveRequestApplyResult()
    end
    g.NavTabbingCounter = 0
    g.NavMoveSubmitted = false
    g.NavMoveScoringItems = false
    if g.NavCursorHideFrames > 0 then
        g.NavCursorHideFrames = g.NavCursorHideFrames - 1
        if g.NavCursorHideFrames == 0 then
            g.NavCursorVisible = true
        end
    end

    -- Schedule mouse position update (will be done at the bottom of this function, after 1) processing all move requests and 2) updating scrolling)
    local set_mouse_pos = false
    if g.NavMousePosDirty and g.NavIdIsAlive then
        if g.NavCursorVisible and g.NavHighlightItemUnderNav and g.NavWindow then
            set_mouse_pos = true
        end
    end
    g.NavMousePosDirty = false
    IM_ASSERT(g.NavLayer == ImGuiNavLayer.Main or g.NavLayer == ImGuiNavLayer.Menu)

    -- Store our return window (for returning from Menu Layer to Main Layer) and clear it as soon as we step back in our own Layer 0
    if g.NavWindow then
        ImGui.NavSaveLastChildNavWindowIntoParent(g.NavWindow)
    end
    if g.NavWindow and g.NavWindow.NavLastChildNavWindow ~= nil and g.NavLayer == ImGuiNavLayer.Main then
        g.NavWindow.NavLastChildNavWindow = nil
    end

    -- Update Ctrl+Tab and Windowing features (hold Square to move/resize/etc.)
    ImGui.NavUpdateWindowing()

    -- Set output flags for user application
    io.NavActive = (nav_keyboard_active or nav_gamepad_active) and g.NavWindow and bit32.band(g.NavWindow.Flags, ImGuiWindowFlags.NoNavInputs) == 0
    io.NavVisible = (io.NavActive and g.NavId ~= 0 and g.NavCursorVisible) or (g.NavWindowingTarget ~= nil)

    -- Process NavCancel input (to close a popup, get back to parent, clear focus)
    ImGui.NavUpdateCancelRequest()
    ImGui.NavUpdateContextMenuRequest()

    -- Process manual activation request
    g.NavActivateId = 0
    g.NavActivateDownId = 0
    g.NavActivatePressedId = 0
    g.NavActivateFlags = ImGuiActivateFlags.None

    if g.NavId ~= 0 and g.NavCursorVisible and not g.NavWindowingTarget and g.NavWindow and bit32.band(g.NavWindow.Flags, ImGuiWindowFlags.NoNavInputs) == 0 then
        local activate_down = (nav_keyboard_active and ImGui.IsKeyDown(ImGuiKey.Space, ImGuiKeyOwner_NoOwner)) or (nav_gamepad_active and ImGui.IsKeyDown(ImGuiKey.NavGamepadActivate, ImGuiKeyOwner_NoOwner))
        local activate_pressed = activate_down and ((nav_keyboard_active and ImGui.IsKeyPressedEx(ImGuiKey.Space, ImGuiInputFlags.None, ImGuiKeyOwner_NoOwner)) or (nav_gamepad_active and ImGui.IsKeyPressedEx(ImGuiKey.NavGamepadActivate, ImGuiInputFlags.None, ImGuiKeyOwner_NoOwner)))
        local input_pressed_keyboard = nav_keyboard_active and (ImGui.IsKeyPressedEx(ImGuiKey.Enter, ImGuiInputFlags.None, ImGuiKeyOwner_NoOwner) or ImGui.IsKeyPressedEx(ImGuiKey.KeypadEnter, ImGuiInputFlags.None, ImGuiKeyOwner_NoOwner))
        local input_pressed_gamepad = false
        if activate_down and nav_gamepad_active and ImGui.IsKeyDown(ImGuiKey.NavGamepadActivate, ImGuiKeyOwner_NoOwner) and bit32.band(g.NavIdItemFlags, ImGuiItemFlags.Inputable) ~= 0 then -- requires ImGuiItemFlags.Inputable to avoid retriggering regular buttons.
            if ImGui.GetKeyData(g, ImGuiKey.NavGamepadActivate).DownDurationPrev < NAV_ACTIVATE_INPUT_WITH_GAMEPAD_DELAY and ImGui.GetKeyData(g, ImGuiKey.NavGamepadActivate).DownDuration >= NAV_ACTIVATE_INPUT_WITH_GAMEPAD_DELAY then
                input_pressed_gamepad = true
            end
        end

        if g.ActiveId == 0 and activate_pressed then
            g.NavActivateId = g.NavId
            g.NavActivateFlags = ImGuiActivateFlags.PreferTweak
        end
        if (g.ActiveId == 0 or g.ActiveId == g.NavId) and (input_pressed_keyboard or input_pressed_gamepad) then
            g.NavActivateId = g.NavId
            g.NavActivateFlags = ImGuiActivateFlags.PreferInput
        end
        if (g.ActiveId == 0 or g.ActiveId == g.NavId) and (activate_down or input_pressed_keyboard or input_pressed_gamepad) then -- FIXME-NAV: Unsure why input_pressed_xxx (migrated from input_down which was already dubious)
            g.NavActivateDownId = g.NavId
        end
        if (g.ActiveId == 0 or g.ActiveId == g.NavId) and (activate_pressed or input_pressed_keyboard or input_pressed_gamepad) then
            g.NavActivatePressedId = g.NavId
            ImGui.NavHighlightActivated(g.NavId)
        end
    end
    if g.NavWindow and bit32.band(g.NavWindow.Flags, ImGuiWindowFlags.NoNavInputs) ~= 0 then
        g.NavCursorVisible = false
    elseif g.IO.ConfigNavCursorVisibleAlways and g.NavCursorHideFrames == 0 then
        g.NavCursorVisible = true
    end
    if g.NavActivateId ~= 0 then
        IM_ASSERT(g.NavActivateDownId == g.NavActivateId)
    end

    -- Highlight
    if g.NavHighlightActivatedTimer > 0.0 then
        g.NavHighlightActivatedTimer = ImMax(0.0, g.NavHighlightActivatedTimer - io.DeltaTime)
    end
    if g.NavHighlightActivatedTimer == 0.0 then
        g.NavHighlightActivatedId = 0
    end

    -- Process programmatic activation request
    -- FIXME-NAV: Those should eventually be queued (unlike focus they don't cancel each others)
    if g.NavNextActivateId ~= 0 then
        g.NavActivateId = g.NavNextActivateId
        g.NavActivateDownId = g.NavNextActivateId
        g.NavActivatePressedId = g.NavNextActivateId
        g.NavActivateFlags = g.NavNextActivateFlags
    end
    g.NavNextActivateId = 0

    -- Process move requests
    ImGui.NavUpdateCreateMoveRequest()
    if g.NavMoveDir == ImGuiDir.None then
        ImGui.NavUpdateCreateTabbingRequest()
    end
    ImGui.NavUpdateAnyRequestFlag()
    g.NavIdIsAlive = false

    -- Scrolling
    if g.NavWindow and bit32.band(g.NavWindow.Flags, ImGuiWindowFlags.NoNavInputs) == 0 and not g.NavWindowingTarget then
        -- *Fallback* manual-scroll with Nav directional keys when window has no navigable item
        local window = g.NavWindow
        local scroll_speed = IM_ROUND(window.FontRefSize * 100 * io.DeltaTime) -- We need round the scrolling speed because sub-pixel scroll isn't reliably supported.
        local move_dir = g.NavMoveDir
        if window.DC.NavLayersActiveMask == 0x00 and window.DC.NavWindowHasScrollY and move_dir ~= ImGuiDir.None then
            if move_dir == ImGuiDir.Left or move_dir == ImGuiDir.Right then
                local delta = (move_dir == ImGuiDir.Left) and -1.0 or 1.0
                ImGui.SetScrollX(window, ImTrunc(window.Scroll.x + delta * scroll_speed))
            end
            if move_dir == ImGuiDir.Up or move_dir == ImGuiDir.Down then
                local delta = (move_dir == ImGuiDir.Up) and -1.0 or 1.0
                ImGui.SetScrollY(window, ImTrunc(window.Scroll.y + delta * scroll_speed))
            end
        end

        -- *Normal* Manual scroll with LStick
        -- Next movement request will clamp the NavId reference rectangle to the visible area, so navigation will resume within those bounds.
        if nav_gamepad_active then
            local scroll_dir = ImGui.GetKeyMagnitude2d(ImGuiKey.GamepadLStickLeft, ImGuiKey.GamepadLStickRight, ImGuiKey.GamepadLStickUp, ImGuiKey.GamepadLStickDown)
            local tweak_factor = 1.0
            if ImGui.IsKeyDown(ImGuiKey.NavGamepadTweakSlow) then
                tweak_factor = 1.0 / 10.0
            elseif ImGui.IsKeyDown(ImGuiKey.NavGamepadTweakFast) then
                tweak_factor = 10.0
            end
            if scroll_dir.x ~= 0.0 and window.ScrollbarX then
                ImGui.SetScrollX(window, ImTrunc(window.Scroll.x + scroll_dir.x * scroll_speed * tweak_factor))
            end
            if scroll_dir.y ~= 0.0 then
                ImGui.SetScrollY(window, ImTrunc(window.Scroll.y + scroll_dir.y * scroll_speed * tweak_factor))
            end
        end
    end

    -- Always prioritize mouse highlight if navigation is disabled
    if not nav_keyboard_active and not nav_gamepad_active then
        g.NavCursorVisible = false
        g.NavHighlightItemUnderNav = false
        set_mouse_pos = false
    end

    -- Update mouse position if requested
    -- (This will take into account the possibility that a Scroll was queued in the window to offset our absolute mouse position before scroll has been applied)
    if set_mouse_pos and io.ConfigNavMoveSetMousePos and bit32.band(io.BackendFlags, ImGuiBackendFlags.HasSetMousePos) ~= 0 then
        ImGui.TeleportMousePos(ImGui.NavCalcPreferredRefPos(ImGuiWindowFlags.Popup))
    end

    -- [DEBUG]
    g.NavScoringDebugCount = 0
end

end

-- Process Escape/NavCancel input (to close a popup, get back to parent, clear focus)
-- FIXME: In order to support e.g. Escape to clear a selection we'll need:
-- - either to store the equivalent of ActiveIdUsingKeyInputMask for a FocusScope and test for it.
-- - either to move most/all of those tests to the epilogue/end functions of the scope they are dealing with (e.g. exit child window in EndChild()) or in EndFrame(), to allow an earlier intercept
function ImGui.NavUpdateCancelRequest()
    local g = GImGui
    local nav_gamepad_active = bit32.band(g.IO.ConfigFlags, ImGuiConfigFlags.NavEnableGamepad) ~= 0 and bit32.band(g.IO.BackendFlags, ImGuiBackendFlags.HasGamepad) ~= 0
    local nav_keyboard_active = bit32.band(g.IO.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard) ~= 0
    if not (nav_keyboard_active and ImGui.IsKeyPressedEx(ImGuiKey.Escape, 0, ImGuiKeyOwner_NoOwner)) and not (nav_gamepad_active and ImGui.IsKeyPressedEx(ImGuiKey.NavGamepadCancel, 0, ImGuiKeyOwner_NoOwner)) then
        return
    end

    -- IMGUI_DEBUG_LOG_NAV("[nav] NavUpdateCancelRequest()")
    if g.ActiveId ~= 0 then
        ImGui.ClearActiveID()
    elseif g.NavLayer ~= ImGuiNavLayer.Main then
        -- Leave the "menu" layer
        ImGui.NavRestoreLayer(ImGuiNavLayer.Main)
        ImGui.SetNavCursorVisibleAfterMove()
    elseif g.NavWindow and g.NavWindow ~= g.NavWindow.RootWindow and bit32.band(g.NavWindow.RootWindowForNav.Flags, ImGuiWindowFlags.Popup) == 0 and g.NavWindow.RootWindowForNav.ParentWindow then
        -- Exit child window
        local child_window = g.NavWindow.RootWindowForNav
        local parent_window = child_window.ParentWindow
        IM_ASSERT(child_window.ChildId ~= 0)
        ImGui.FocusWindow(parent_window)
        ImGui.SetNavID(child_window.ChildId, ImGuiNavLayer.Main, 0, ImGui.WindowRectAbsToRel(parent_window, child_window:Rect()))
        ImGui.SetNavCursorVisibleAfterMove()
    elseif g.OpenPopupStack.Size > 0 and g.OpenPopupStack:back().Window ~= nil and bit32.band(g.OpenPopupStack:back().Window.Flags, ImGuiWindowFlags.Modal) == 0 then
        -- Close open popup/menu
        ImGui.ClosePopupToLevel(g.OpenPopupStack.Size - 1, true)
    else
        -- Clear NavLastId for popups but keep it for regular child window so we can leave one and come back where we were
        -- FIXME-NAV: This should happen on window appearing.
        if g.IO.ConfigNavEscapeClearFocusItem or g.IO.ConfigNavEscapeClearFocusWindow then
            if g.NavWindow and bit32.band(g.NavWindow.Flags, ImGuiWindowFlags.Popup) ~= 0 then -- or not (g.NavWindow.Flags & ImGuiWindowFlags.ChildWindow)
                g.NavWindow.NavLastIds[0] = 0
            end
        end

        -- Clear nav focus
        if g.IO.ConfigNavEscapeClearFocusItem or g.IO.ConfigNavEscapeClearFocusWindow then
            g.NavId = 0
        end
        if g.IO.ConfigNavEscapeClearFocusWindow then
            ImGui.FocusWindow(nil)
        end
    end
end

function ImGui.NavMoveRequestButNoResultYet()
    local g = GImGui
    return g.NavMoveScoringItems and g.NavMoveResultLocal.ID == 0 and g.NavMoveResultOther.ID == 0
end

local function ImGetDirQuadrantFromDelta(dx, dy)
    if ImFabs(dx) > ImFabs(dy) then
        return (dx > 0.0) and ImGuiDir.Right or ImGuiDir.Left
    end
    return (dy > 0.0) and ImGuiDir.Down or ImGuiDir.Up
end

local function NavScoreItemDistInterval(cand_min, cand_max, curr_min, curr_max)
    if cand_max < curr_min then
        return cand_max - curr_min
    end
    if curr_max < cand_min then
        return cand_min - curr_max
    end
    return 0.0
end

-- Scoring function for keyboard/gamepad directional navigation. Based on https://gist.github.com/rygorous/6981057
--- @param result ImGuiNavItemData
--- @param nav_bb ImRect
--- @return bool
function ImGui.NavScoreItem(result, nav_bb)
    local g = GImGui
    local window = g.CurrentWindow
    if g.NavLayer ~= window.DC.NavLayerCurrent then
        return false
    end

    -- FIXME: Those are not good variables names
    local cand = ImRect()
    ImRect_Copy(cand, nav_bb)       -- Current item nav rectangle
    local curr = g.NavScoringRect   -- Current modified source rect (NB: we've applied Max.x = Min.x in NavUpdate() to inhibit the effect of having varied item width)
    g.NavScoringDebugCount = g.NavScoringDebugCount + 1

    -- When entering through a NavFlattened border, we consider child window items as fully clipped for scoring
    if window.ParentWindow == g.NavWindow then
        IM_ASSERT(bit32.band(bit32.bor(window.ChildFlags, g.NavWindow.ChildFlags), ImGuiChildFlags.NavFlattened) ~= 0)
        if not window.ClipRect:Overlaps(cand) then
            return false
        end
        cand:ClipWithFull(window.ClipRect) -- This allows the scored item to not overlap other candidates in the parent window
    end

    -- Compute distance between boxes
    -- FIXME-NAV: Introducing biases for vertical navigation, needs to be removed.
    local dbx = NavScoreItemDistInterval(cand.Min.x, cand.Max.x, curr.Min.x, curr.Max.x)
    local dby = NavScoreItemDistInterval(ImLerp(cand.Min.y, cand.Max.y, 0.2), ImLerp(cand.Min.y, cand.Max.y, 0.8), ImLerp(curr.Min.y, curr.Max.y, 0.2), ImLerp(curr.Min.y, curr.Max.y, 0.8)) -- Scale down on Y to keep using box-distance for vertically touching items
    if dby ~= 0.0 and dbx ~= 0.0 then
        dbx = (dbx / 1000.0) + ((dbx > 0.0) and 1.0 or -1.0)
    end
    local dist_box = ImFabs(dbx) + ImFabs(dby)

    -- Compute distance between centers (this is off by a factor of 2, but we only compare center distances with each other so it doesn't matter)
    local dcx = (cand.Min.x + cand.Max.x) - (curr.Min.x + curr.Max.x)
    local dcy = (cand.Min.y + cand.Max.y) - (curr.Min.y + curr.Max.y)
    local dist_center = ImFabs(dcx) + ImFabs(dcy) -- L1 metric (need this for our connectedness guarantee)

    -- Determine which quadrant of 'curr' our candidate item 'cand' lies in based on distance
    local quadrant
    local dax = 0.0
    local day = 0.0
    local dist_axial = 0.0
    if dbx ~= 0.0 or dby ~= 0.0 then
        -- For non-overlapping boxes, use distance between boxes
        -- FIXME-NAV: Quadrant may be incorrect because of (1) dbx bias and (2) curr.Max.y bias applied by NavBiasScoringRect() where typically curr.Max.y==curr.Min.y
        -- One typical case where this happens, with style.WindowMenuButtonPosition == ImGuiDir.Right, pressing Left to navigate from Close to Collapse tends to fail.
        -- Also see #6344. Calling ImGetDirQuadrantFromDelta() with unbiased values may be good but side-effects are plenty.
        dax = dbx
        day = dby
        dist_axial = dist_box
        quadrant = ImGetDirQuadrantFromDelta(dbx, dby)
    elseif dcx ~= 0.0 or dcy ~= 0.0 then
        -- For overlapping boxes with different centers, use distance between centers
        dax = dcx
        day = dcy
        dist_axial = dist_center
        quadrant = ImGetDirQuadrantFromDelta(dcx, dcy)
    else
        -- Degenerate case: two overlapping buttons with same center, break ties arbitrarily (note that LastItemId here is really the _previous_ item order, but it doesn't matter)
        quadrant = (g.LastItemData.ID < g.NavId) and ImGuiDir.Left or ImGuiDir.Right
    end

    local move_dir = g.NavMoveDir

    -- Is it in the quadrant we're interested in moving to?
    local new_best = false
    if quadrant == move_dir then
        -- Does it beat the current best candidate?
        if dist_box < result.DistBox then
            result.DistBox = dist_box
            result.DistCenter = dist_center
            return true
        end
        if dist_box == result.DistBox then
            -- Try using distance between center points to break ties
            if dist_center < result.DistCenter then
                result.DistCenter = dist_center
                new_best = true
            elseif dist_center == result.DistCenter then
                -- Still tied! we need to be extra-careful to make sure everything gets linked properly. We consistently break ties by symbolically moving "later" items
                -- (with higher index) to the right/downwards by an infinitesimal amount since we the current "best" button already (so it must have a lower index),
                -- this is fairly easy. This rule ensures that all buttons with dx==dy==0 will end up being linked in order of appearance along the x axis.
                if (((move_dir == ImGuiDir.Up or move_dir == ImGuiDir.Down) and dby) or dbx) < 0.0 then -- moving bj to the right/down decreases distance
                    new_best = true
                end
            end
        end
    end

    -- Axial check: if 'curr' has no link at all in some direction and 'cand' lies roughly in that direction, add a tentative link. This will only be kept if no "real" matches
    -- are found, so it only augments the graph produced by the above method using extra links. (important, since it doesn't guarantee strong connectedness)
    -- This is just to avoid buttons having no links in a particular direction when there's a suitable neighbor. you get good graphs without this too.
    -- 2017/09/29: FIXME: This now currently only enabled inside menu bars, ideally we'd disable it everywhere. Menus in particular need to catch failure. For general navigation it feels awkward.
    -- Disabling it may lead to disconnected graphs when nodes are very spaced out on different axis. Perhaps consider offering this as an option?
    if result.DistBox == FLT_MAX and dist_axial < result.DistAxial then -- Check axial match
        if g.NavLayer == ImGuiNavLayer.Menu and bit32.band(g.NavWindow.Flags, ImGuiWindowFlags.ChildMenu) == 0 then
            if (move_dir == ImGuiDir.Left and dax < 0.0) or (move_dir == ImGuiDir.Right and dax > 0.0) or (move_dir == ImGuiDir.Up and day < 0.0) or (move_dir == ImGuiDir.Down and day > 0.0) then
                result.DistAxial = dist_axial
                new_best = true
            end
        end
    end

    return new_best
end

--- @param result ImGuiNavItemData
function ImGui.NavApplyItemToResult(result)
    local g = GImGui
    local window = g.CurrentWindow
    result.Window = window
    result.ID = g.LastItemData.ID
    result.FocusScopeId = g.CurrentFocusScopeId
    result.ItemFlags = g.LastItemData.ItemFlags
    ImRect_Copy(result.RectRel, ImGui.WindowRectAbsToRel(window, g.LastItemData.NavRect))
    if bit32.band(result.ItemFlags, ImGuiItemFlags.HasSelectionUserData) ~= 0 then
        IM_ASSERT(g.NextItemData.SelectionUserData ~= ImGuiSelectionUserData_Invalid)
        result.SelectionUserData = g.NextItemData.SelectionUserData -- INTENTIONAL: At this point this field is not cleared in NextItemData. Avoid unnecessary copy to LastItemData.
    end
end

--- @param result ImGuiNavItemData
function ImGui.NavMoveRequestResolveWithLastItem(result)
    local g = GImGui
    g.NavMoveScoringItems = false -- Ensure request doesn't need more processing
    ImGui.NavApplyItemToResult(result)
    ImGui.NavUpdateAnyRequestFlag()
end

-- Handle "scoring" of an item for a tabbing/focusing request initiated by NavUpdateCreateTabbingRequest().
-- Note that SetKeyboardFocusHere() API calls are considered tabbing requests!
-- - Case 1: no nav/active id:    set result to first eligible item, stop storing.
-- - Case 2: tab forward:         on ref id set counter, on counter elapse store result
-- - Case 3: tab forward wrap:    set result to first eligible item (preemptively), on ref id set counter, on next frame if counter hasn't elapsed store result. -- FIXME-TABBING: Could be done as a next-frame forwarded request
-- - Case 4: tab backward:        store all results, on ref id pick prev, stop storing
-- - Case 5: tab backward wrap:   store all results, on ref id if no result keep storing until last -- FIXME-TABBING: Could be done as next-frame forwarded requested
--- @param id         ImGuiID
--- @param item_flags ImGuiItemFlags
--- @param move_flags ImGuiNavMoveFlags
function ImGui.NavProcessItemForTabbingRequest(id, item_flags, move_flags)
    local g = GImGui

    if bit32.band(move_flags, ImGuiNavMoveFlags.FocusApi) == 0 then
        if g.NavLayer ~= g.CurrentWindow.DC.NavLayerCurrent then
            return
        end
        if g.NavFocusScopeId ~= g.CurrentFocusScopeId then
            return
        end
    end

    -- - Can always land on an item when using API call.
    -- - Tabbing with _NavEnableKeyboard (space/enter/arrows): goes through every item.
    -- - Tabbing without _NavEnableKeyboard: goes through inputable items only.
    local can_stop
    if bit32.band(move_flags, ImGuiNavMoveFlags.FocusApi) ~= 0 then
        can_stop = true
    else
        can_stop = bit32.band(item_flags, ImGuiItemFlags.NoTabStop) == 0 and (bit32.band(g.IO.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard) ~= 0 or bit32.band(item_flags, ImGuiItemFlags.Inputable) ~= 0)
    end

    -- Always store in NavMoveResultLocal (unlike directional request which uses NavMoveResultOther on sibling/flattened windows)
    local result = g.NavMoveResultLocal
    if g.NavTabbingDir == 1 then
        -- Tab Forward or SetKeyboardFocusHere() with >= 0
        if can_stop and g.NavTabbingResultFirst.ID == 0 then
            ImGui.NavApplyItemToResult(g.NavTabbingResultFirst)
        end
        if can_stop and g.NavTabbingCounter > 0 then
            g.NavTabbingCounter = g.NavTabbingCounter - 1
            if g.NavTabbingCounter == 0 then
                ImGui.NavMoveRequestResolveWithLastItem(result)
            end
        elseif g.NavId == id then
            g.NavTabbingCounter = 1
        end
    elseif g.NavTabbingDir == -1 then
        -- Tab Backward
        if g.NavId == id then
            if result.ID ~= 0 then
                g.NavMoveScoringItems = false
                ImGui.NavUpdateAnyRequestFlag()
            end
        elseif can_stop then
            -- Keep applying until reaching NavId
            ImGui.NavApplyItemToResult(result)
        end
    elseif g.NavTabbingDir == 0 then
        if can_stop and g.NavId == id then
            ImGui.NavMoveRequestResolveWithLastItem(result)
        end
        if can_stop and g.NavTabbingResultFirst.ID == 0 then -- Tab init
            ImGui.NavApplyItemToResult(g.NavTabbingResultFirst)
        end
    end
end

-- We get there when either NavId == id, or when g.NavAnyRequest is set (which is updated by NavUpdateAnyRequestFlag above)
-- This is called after LastItemData is set, but NextItemData is also still valid.
function ImGui.NavProcessItem()
    local g = GImGui
    local window = g.CurrentWindow
    local id = g.LastItemData.ID
    local item_flags = g.LastItemData.ItemFlags

    -- When inside a container that isn't scrollable with Left<>Right, clip NavRect accordingly (#2221, #8816, #7994)
    local nav_bb = ImRect()
    ImRect_Copy(nav_bb, g.LastItemData.NavRect)
    if window.DC.NavIsScrollPushableX == false then
        nav_bb.Min.x = ImClamp(nav_bb.Min.x, window.ClipRect.Min.x, window.ClipRect.Max.x)
        nav_bb.Max.x = ImClamp(nav_bb.Max.x, window.ClipRect.Min.x, window.ClipRect.Max.x)
    end

    -- Process Init Request
    if g.NavInitRequest and g.NavLayer == window.DC.NavLayerCurrent and bit32.band(item_flags, ImGuiItemFlags.Disabled) == 0 then
        -- Even if 'ImGuiItemFlags.NoNavDefaultFocus' is on (typically collapse/close button) we record the first ResultId so they can be used as a fallback
        local candidate_for_nav_default_focus = bit32.band(item_flags, ImGuiItemFlags.NoNavDefaultFocus) == 0
        if candidate_for_nav_default_focus or g.NavInitResult.ID == 0 then
            ImGui.NavApplyItemToResult(g.NavInitResult)
        end
        if candidate_for_nav_default_focus then
            g.NavInitRequest = false -- Found a match, clear request
            ImGui.NavUpdateAnyRequestFlag()
        end
    end

    -- Process Move Request (scoring for navigation)
    -- FIXME-NAV: Consider policy for double scoring (scoring from NavScoringRect + scoring from a rect wrapped according to current wrapping policy)
    if g.NavMoveScoringItems and bit32.band(item_flags, ImGuiItemFlags.Disabled) == 0 then
        if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.FocusApi) ~= 0 or bit32.band(window.Flags, ImGuiWindowFlags.NoNavInputs) == 0 then
            local is_tabbing = bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.IsTabbing) ~= 0
            if is_tabbing then
                ImGui.NavProcessItemForTabbingRequest(id, item_flags, g.NavMoveFlags)
            elseif g.NavId ~= id or bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.AllowCurrentNavId) ~= 0 then
                local result = (window == g.NavWindow) and g.NavMoveResultLocal or g.NavMoveResultOther
                if ImGui.NavScoreItem(result, nav_bb) then
                    ImGui.NavApplyItemToResult(result)
                end

                -- Features like PageUp/PageDown need to maintain a separate score for the visible set of items.
                local VISIBLE_RATIO = 0.70
                if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.AlsoScoreVisibleSet) ~= 0 then
                    local r = window.InnerRect -- window.ClipRect
                    if r:Overlaps(nav_bb) then
                        if ImClamp(nav_bb.Max.y, r.Min.y, r.Max.y) - ImClamp(nav_bb.Min.y, r.Min.y, r.Max.y) >= (nav_bb.Max.y - nav_bb.Min.y) * VISIBLE_RATIO then
                            if ImGui.NavScoreItem(g.NavMoveResultLocalVisible, nav_bb) then
                                ImGui.NavApplyItemToResult(g.NavMoveResultLocalVisible)
                            end
                        end
                    end
                end
            end
        end
    end

    -- Update information for currently focused/navigated item
    if g.NavId == id then
        if g.NavWindow ~= window then
            ImGui.SetNavWindow(window) -- Always refresh g.NavWindow, because some operations such as FocusItem() may not have a window.
        end
        g.NavLayer = window.DC.NavLayerCurrent
        ImGui.SetNavFocusScope(g.CurrentFocusScopeId) -- Will set g.NavFocusScopeId AND store g.NavFocusScopePath
        g.NavFocusScopeId = g.CurrentFocusScopeId
        g.NavIdIsAlive = true
        g.NavIdItemFlags = item_flags
        if bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.HasSelectionUserData) ~= 0 then
            IM_ASSERT(g.NextItemData.SelectionUserData ~= ImGuiSelectionUserData_Invalid)
            g.NavLastValidSelectionUserData = g.NextItemData.SelectionUserData -- INTENTIONAL: At this point this field is not cleared in NextItemData. Avoid unnecessary copy to LastItemData.
        end
        window.NavRectRel[window.DC.NavLayerCurrent] = ImGui.WindowRectAbsToRel(window, nav_bb) -- Store item bounding box (relative to window position)
    end
end

function ImGui.NavInitRequestApplyResult()
    -- In very rare cases g.NavWindow may be null (e.g. clearing focus after requesting an init request, which does happen when releasing Alt while clicking on void)
    local g = GImGui
    if not g.NavWindow then
        return
    end

    local result = g.NavInitResult
    if g.NavId ~= result.ID then
        g.NavJustMovedFromFocusScopeId = g.NavFocusScopeId
        g.NavJustMovedToId = result.ID
        g.NavJustMovedToFocusScopeId = result.FocusScopeId
        g.NavJustMovedToKeyMods = 0
        g.NavJustMovedToIsTabbing = false
        g.NavJustMovedToHasSelectionData = bit32.band(result.ItemFlags, ImGuiItemFlags.HasSelectionUserData) ~= 0
    end

    -- Apply result from previous navigation init request (will typically select the first item, unless SetItemDefaultFocus() has been called)
    -- FIXME-NAV: On _NavFlattened windows, g.NavWindow will only be updated during subsequent frame. Not a problem currently.
    -- IMGUI_DEBUG_LOG_NAV("[nav] NavInitRequest: ApplyResult: NavID 0x%08X in Layer %d Window \"%s\"\n", result->ID, g.NavLayer, g.NavWindow->Name)
    ImGui.SetNavID(result.ID, g.NavLayer, result.FocusScopeId, result.RectRel)
    g.NavIdIsAlive = true -- Mark as alive from previous frame as we got a result
    if result.SelectionUserData ~= ImGuiSelectionUserData_Invalid then
        g.NavLastValidSelectionUserData = result.SelectionUserData
    end
    if g.NavInitRequestFromMove then
        ImGui.SetNavCursorVisibleAfterMove()
    end
end

-- Apply result from previous frame navigation directional move request. Always called from NavUpdate()
function ImGui.NavMoveRequestApplyResult()
    local g = GImGui

    -- Select which result to use
    local result
    if g.NavMoveResultLocal.ID ~= 0 then
        result = g.NavMoveResultLocal
    elseif g.NavMoveResultOther.ID ~= 0 then
        result = g.NavMoveResultOther
    else
        result = nil
    end

    -- Tabbing forward wrap
    if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.IsTabbing) ~= 0 and result == nil then
        if (g.NavTabbingCounter == 1 or g.NavTabbingDir == 0) and g.NavTabbingResultFirst.ID ~= 0 then
            result = g.NavTabbingResultFirst
        end
    end

    -- In a situation when there are no results but NavId != 0, re-enable the Navigation highlight (because g.NavId is not considered as a possible result)
    local axis = (g.NavMoveDir == ImGuiDir.Up or g.NavMoveDir == ImGuiDir.Down) and ImGuiAxis.Y or ImGuiAxis.X
    if result == nil then
        if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.IsTabbing) ~= 0 then
            g.NavMoveFlags = bit32.bor(g.NavMoveFlags, ImGuiNavMoveFlags.NoSetNavCursorVisible)
        end
        if g.NavId ~= 0 and bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.NoSetNavCursorVisible) == 0 then
            ImGui.SetNavCursorVisibleAfterMove()
        end
        ImGui.NavClearPreferredPosForAxis(axis) -- On a failed move, clear preferred pos for this axis.
        -- IMGUI_DEBUG_LOG_NAV("[nav] NavMoveSubmitted but not led to a result!\n")
        return
    end

    -- PageUp/PageDown behavior first jumps to the bottom/top mostly visible item, _otherwise_ use the result from the previous/next page.
    if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.AlsoScoreVisibleSet) ~= 0
        and g.NavMoveResultLocalVisible.ID ~= 0 and g.NavMoveResultLocalVisible.ID ~= g.NavId then
        result = g.NavMoveResultLocalVisible
    end

    -- Maybe entering a flattened child from the outside? In this case solve the tie using the regular scoring rules.
    if result ~= g.NavMoveResultOther and g.NavMoveResultOther.ID ~= 0 and g.NavMoveResultOther.Window.ParentWindow == g.NavWindow then
        if g.NavMoveResultOther.DistBox < result.DistBox
            or (g.NavMoveResultOther.DistBox == result.DistBox and g.NavMoveResultOther.DistCenter < result.DistCenter) then
            result = g.NavMoveResultOther
        end
    end
    IM_ASSERT(g.NavWindow and result.Window)

    -- Scroll to keep newly navigated item fully into view.
    if g.NavLayer == ImGuiNavLayer.Main then
        local rect_abs = ImGui.WindowRectRelToAbs(result.Window, result.RectRel)
        ImGui.ScrollToRectEx(result.Window, rect_abs, g.NavMoveScrollFlags)

        if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.ScrollToEdgeY) ~= 0 then
            -- FIXME: Should remove this? Or make more precise: use ScrollToRectEx() with edge?
            local scroll_target = (g.NavMoveDir == ImGuiDir.Up) and result.Window.ScrollMax.y or 0.0
            ImGui.SetScrollY(result.Window, scroll_target)
        end
    end

    if g.NavWindow ~= result.Window then
        -- IMGUI_DEBUG_LOG_FOCUS("[focus] NavMoveRequest: SetNavWindow(\"%s\")\n", result->Window->Name)
        g.NavWindow = result.Window
        g.NavLastValidSelectionUserData = ImGuiSelectionUserData_Invalid
    end

    -- Clear active id unless requested not to
    -- FIXME: ImGuiNavMoveFlags.NoClearActiveId is currently unused as we don't have a clear strategy to preserve active id after interaction,
    -- so this is mostly provided as a gateway for further experiments (see #1418, #2890)
    if g.ActiveId ~= result.ID and bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.NoClearActiveId) == 0 then
        ImGui.ClearActiveID()
    end

    -- Don't set NavJustMovedToId if just landed on the same spot (which may happen with ImGuiNavMoveFlags.AllowCurrentNavId)
    -- PageUp/PageDown however sets always set NavJustMovedTo (vs Home/End which doesn't) mimicking Windows behavior.
    if (g.NavId ~= result.ID or bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.IsPageMove) ~= 0)
        and bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.NoSelect) == 0 then
        g.NavJustMovedFromFocusScopeId = g.NavFocusScopeId
        g.NavJustMovedToId = result.ID
        g.NavJustMovedToFocusScopeId = result.FocusScopeId
        g.NavJustMovedToKeyMods = g.NavMoveKeyMods
        g.NavJustMovedToIsTabbing = bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.IsTabbing) ~= 0
        g.NavJustMovedToHasSelectionData = bit32.band(result.ItemFlags, ImGuiItemFlags.HasSelectionUserData) ~= 0
        -- IMGUI_DEBUG_LOG_NAV("[nav] NavJustMovedFromFocusScopeId = 0x%08X, NavJustMovedToFocusScopeId = 0x%08X\n", g.NavJustMovedFromFocusScopeId, g.NavJustMovedToFocusScopeId)
    end

    -- Apply new NavID/Focus
    -- IMGUI_DEBUG_LOG_NAV("[nav] NavMoveRequest: result NavID 0x%08X in Layer %d Window \"%s\"\n", result->ID, g.NavLayer, g.NavWindow->Name)
    local root_for_nav = g.NavWindow.RootWindowForNav
    local preferred_scoring_pos_rel = ImVec2()
    ImVec2_Copy(preferred_scoring_pos_rel, root_for_nav.NavPreferredScoringPosRel[g.NavLayer])
    ImGui.SetNavID(result.ID, g.NavLayer, result.FocusScopeId, result.RectRel)
    if result.SelectionUserData ~= ImGuiSelectionUserData_Invalid then
        g.NavLastValidSelectionUserData = result.SelectionUserData
    end

    -- Restore last preferred position for current axis
    -- (storing in RootWindowForNav-> as the info is desirable at the beginning of a Move Request. In theory all storage should use RootWindowForNav..)
    if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.IsTabbing) == 0 then
        preferred_scoring_pos_rel[axis] = result.RectRel:GetCenter()[axis]
        ImVec2_Copy(root_for_nav.NavPreferredScoringPosRel[g.NavLayer], preferred_scoring_pos_rel)
    end

    -- Tabbing: Activates Inputable, otherwise only Focus
    if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.IsTabbing) ~= 0
        and bit32.band(result.ItemFlags, ImGuiItemFlags.Inputable) == 0 then
        g.NavMoveFlags = bit32.band(g.NavMoveFlags, bit32.bnot(ImGuiNavMoveFlags.Activate))
    end

    -- Activate
    if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.Activate) ~= 0 then
        g.NavNextActivateId = result.ID
        g.NavNextActivateFlags = ImGuiActivateFlags.None
        if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.FocusApi) ~= 0 then
            g.NavNextActivateFlags = bit32.bor(g.NavNextActivateFlags, ImGuiActivateFlags.FromFocusApi)
        end
        if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.IsTabbing) ~= 0 then
            g.NavNextActivateFlags = bit32.bor(g.NavNextActivateFlags, ImGuiActivateFlags.PreferInput, ImGuiActivateFlags.TryToPreserveState, ImGuiActivateFlags.FromTabbing)
        end
    end

    -- Make nav cursor visible
    if bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.NoSetNavCursorVisible) == 0 then
        ImGui.SetNavCursorVisibleAfterMove()
    end
end

-- True when current work location may be scrolled horizontally when moving left / right.
-- This is generally always true UNLESS within a column. We don't have a vertical equivalent.
function ImGui.NavUpdateCurrentWindowIsScrollPushableX()
    local g = GImGui
    local window = g.CurrentWindow
    window.DC.NavIsScrollPushableX = (g.CurrentTable == nil and window.DC.CurrentColumns == nil)
end

-- Called by TreePop() to implement ImGuiTreeNodeFlags.NavLeftJumpsToParent
--- @param result         ImGuiNavItemData
--- @param tree_node_data ImGuiTreeNodeStackData
function ImGui.NavMoveRequestResolveWithPastTreeNode(result, tree_node_data)
    local g = GImGui
    g.NavMoveScoringItems = false
    g.LastItemData.ID = tree_node_data.ID
    g.LastItemData.ItemFlags = bit32.band(tree_node_data.ItemFlags, bit32.bnot(ImGuiItemFlags.HasSelectionUserData)) -- Losing SelectionUserData, recovered next-frame (cheaper).
    ImRect_Copy(g.LastItemData.NavRect, tree_node_data.NavRect)
    ImGui.NavApplyItemToResult(result) -- Result this instead of implementing a NavApplyPastTreeNodeToResult()
    ImGui.NavClearPreferredPosForAxis(ImGuiAxis.Y)
    ImGui.NavUpdateAnyRequestFlag()
end

function ImGui.NavMoveRequestCancel()
    local g = GImGui
    g.NavMoveSubmitted = false
    g.NavMoveScoringItems = false
    ImGui.NavUpdateAnyRequestFlag()
end

-- Forward will reuse the move request again on the next frame (generally with modifications done to it)
--- @param move_dir     ImGuiDir
--- @param clip_dir     ImGuiDir
--- @param move_flags   ImGuiNavMoveFlags
--- @param scroll_flags ImGuiScrollFlags
function ImGui.NavMoveRequestForward(move_dir, clip_dir, move_flags, scroll_flags)
    local g = GImGui
    IM_ASSERT(g.NavMoveForwardToNextFrame == false)
    ImGui.NavMoveRequestCancel()
    g.NavMoveForwardToNextFrame = true
    g.NavMoveDir = move_dir
    g.NavMoveClipDir = clip_dir
    g.NavMoveFlags = bit32.bor(move_flags, ImGuiNavMoveFlags.Forwarded)
    g.NavMoveScrollFlags = scroll_flags
end

-- Navigation wrap-around logic is delayed to the end of the frame because this operation is only valid after entire
-- popup is assembled and in case of appended popups it is not clear which EndPopup() call is final.
--- @param window     ImGuiWindow
--- @param wrap_flags ImGuiNavMoveFlags
function ImGui.NavMoveRequestTryWrapping(window, wrap_flags)
    local g = GImGui
    IM_ASSERT(bit32.band(wrap_flags, ImGuiNavMoveFlags.WrapMask_) ~= 0 and bit32.band(wrap_flags, bit32.bnot(ImGuiNavMoveFlags.WrapMask_)) == 0) -- Call with _WrapX, _WrapY, _LoopX, _LoopY

    -- In theory we should test for NavMoveRequestButNoResultYet() but there's no point doing it:
    -- as NavEndFrame() will do the same test. It will end up calling NavUpdateCreateWrappingRequest().
    if g.NavWindow == window and g.NavMoveScoringItems and g.NavLayer == window.DC.NavLayerCurrent then
        g.NavMoveFlags = bit32.bor(bit32.band(g.NavMoveFlags, bit32.bnot(ImGuiNavMoveFlags.WrapMask_)), wrap_flags)
    end
end

-------------------------------------------------------------------------------
-- [SECTION] DRAG AND DROP
-------------------------------------------------------------------------------

function ImGui.IsDragDropPayloadBeingAccepted()
    local g = GImGui
    return g.DragDropActive and g.DragDropAcceptIdPrev ~= 0
end

-------------------------------------------------------------------------------
-- [SECTION] LOCALIZATION
-------------------------------------------------------------------------------

--- @param entries ImGuiLocEntry[]
--- @param count   int
function ImGui.LocalizeRegisterEntries(entries, count)
    local g = GImGui
    for n = 1, count do
        g.LocalizationTable[entries[n].Key] = entries[n].Text
    end
end

-------------------------------------------------------------------------------
-- [SECTION] VIEWPORTS, PLATFORM WINDOWS
-------------------------------------------------------------------------------
-- - GetMainViewport()
-- - FindViewportByID()
-- - SetCurrentViewport() [Internal]
-- - SetWindowViewport() [Internal]
-- - GetWindowAlwaysWantOwnViewport() [Internal]
-- - UpdateTryMergeWindowIntoHostViewport() [Internal]
-- - UpdateTryMergeWindowIntoHostViewports() [Internal]
-- - TranslateWindowsInViewport() [Internal]
-- - ScaleWindowsInViewport() [Internal]
-- - FindHoveredViewportFromPlatformWindowStack() [Internal]
-- - UpdateViewportsNewFrame() [Internal]
-- - UpdateViewportsEndFrame() [Internal]
-- - AddUpdateViewport() [Internal]
-- - WindowSelectViewport() [Internal]
-- - WindowSyncOwnedViewport() [Internal]
-- - UpdatePlatformWindows()
-- - RenderPlatformWindowsDefault()
-- - FindPlatformMonitorForPos() [Internal]
-- - FindPlatformMonitorForRect() [Internal]
-- - UpdateViewportPlatformMonitor() [Internal]
-- - DestroyPlatformWindow() [Internal]
-- - DestroyPlatformWindows()
-------------------------------------------------------------------------------

function MT.ImGuiViewport:GetDebugName()
    local viewport = self
    return viewport.Window and viewport.Window.Name or "n/a"
end

function MT.ImGuiPlatformIO:ClearPlatformHandlers()
    self.Platform_GetClipboardTextFn = nil; self.Platform_SetClipboardTextFn = nil
    self.Platform_ClipboardUserData  = nil
    self.Platform_OpenInShellFn = nil; self.Platform_OpenInShellUserData = nil
    self.Platform_SetImeDataFn = nil; self.Platform_ImeUserData = nil
    self.Platform_CreateWindow = nil; self.Platform_DestroyWindow = nil; self.Platform_ShowWindow = nil
    self.Platform_SetWindowPos   = nil; self.Platform_SetWindowSize  = nil
    self.Platform_GetWindowPos   = nil; self.Platform_GetWindowSize  = nil; self.Platform_GetWindowFramebufferScale = nil
    self.Platform_SetWindowFocus = nil; self.Platform_GetWindowFocus = nil; self.Platform_GetWindowMinimized        = nil
    self.Platform_SetWindowTitle = nil; self.Platform_SetWindowAlpha = nil; self.Platform_UpdateWindow              = nil
    self.Platform_RenderWindow   = nil; self.Platform_SwapBuffers    = nil; self.Platform_GetWindowDpiScale         = nil
    self.Platform_OnChangedViewport = nil; self.Platform_GetWindowWorkAreaInsets = nil; self.Platform_CreateVkSurface = nil
end

function MT.ImGuiPlatformIO:ClearRendererHandlers()
    self.Renderer_TextureMaxWidth = 0; self.Renderer_TextureMaxHeight = 0
    self.Renderer_RenderState     = nil
    self.Renderer_CreateWindow    = nil; self.Renderer_DestroyWindow  = nil
    self.Renderer_SetWindowSize   = nil
    self.Renderer_RenderWindow    = nil; self.Renderer_SwapBuffers    = nil
end

--- @return ImGuiViewport
function ImGui.GetMainViewport()
    local g = GImGui

    return g.Viewports.Data[1] -- [Luau] .Data[]: no IM_VECTOR.__index
end

-- FIXME: This leaks access to viewports not listed in PlatformIO.Viewports[]. Problematic? (#4236)
--- @param viewport_id ImGuiID
--- @return ImGuiViewport?
function ImGui.FindViewportByID(viewport_id)
    local g = GImGui
    for _, viewport in g.Viewports:iter() do
        if viewport.ID == viewport_id then
            return viewport
        end
    end
    return nil
end

--- @param current_window? ImGuiWindow
--- @param viewport?       ImGuiViewportP
function ImGui.SetCurrentViewport(current_window, viewport)
    local g = GImGui

    if viewport then
        viewport.LastFrameActive = g.FrameCount
    end
    if g.CurrentViewport == viewport then
        return
    end

    g.CurrentDpiScale = viewport and viewport.DpiScale or 1.0
    g.CurrentViewport = viewport
    IM_ASSERT(g.CurrentDpiScale > 0.0 and g.CurrentDpiScale < 99.0)  -- Typical correct values would be between 1.0f and 4.0f
    -- IMGUI_DEBUG_LOG_VIEWPORT("[viewport] SetCurrentViewport changed '%s' 0x%08X", current_window and current_window.Name or "NULL", viewport and viewport.ID or 0)

    if g.IO.ConfigDpiScaleFonts then
        g.Style.FontScaleDpi = g.CurrentDpiScale
    end

    -- Notify platform layer of viewport changes
    -- FIXME-DPI: This is only currently used for experimenting with handling of multiple DPI
    if g.CurrentViewport and g.PlatformIO.Platform_OnChangedViewport then
        g.PlatformIO.Platform_OnChangedViewport(g.CurrentViewport)
    end
end

--- @param window   ImGuiWindow
--- @param viewport ImGuiViewportP
function ImGui.SetWindowViewport(window, viewport)
    -- Abandon viewport
    if window.ViewportOwned and window.Viewport.Window == window then
        window.Viewport.Size = ImVec2(0.0, 0.0)
    end

    window.Viewport = viewport
    window.ViewportId = viewport.ID
    window.ViewportOwned = (viewport.Window == window)
end

--- @param window ImGuiWindow
--- @return bool
function ImGui.GetWindowAlwaysWantOwnViewport(window)
    -- Tooltips and menus are not automatically forced into their own viewport when the NoMerge flag is set, however the multiplication of viewports makes them more likely to protrude and create their own.
    local g = GImGui
    if g.IO.ConfigViewportsNoAutoMerge or (bit32.band(window.WindowClass.ViewportFlagsOverrideSet, ImGuiViewportFlags.NoAutoMerge) ~= 0) then
        if bit32.band(g.ConfigFlagsCurrFrame, ImGuiConfigFlags.ViewportsEnable) ~= 0 then
            if not window.DockIsActive then
                if bit32.band(window.Flags, bit32.bor(ImGuiWindowFlags.ChildWindow, ImGuiWindowFlags.ChildMenu, ImGuiWindowFlags.Tooltip)) == 0 then
                    if bit32.band(window.Flags, ImGuiWindowFlags.Popup) == 0 or bit32.band(window.Flags, ImGuiWindowFlags.Modal) ~= 0 then
                        return true
                    end
                end
            end
        end
    end
    return false
end

-- Heuristic, see #8948: depends on how backends handle OS-level parenting.
-- Due to how parent viewport stack is layed out, note that IsViewportAbove(a,b) isn't always the same as !IsViewportAbove(b,a).
--- @param potential_above ImGuiViewportP
--- @param potential_below ImGuiViewportP
--- @return bool
function ImGui.IsViewportAbove(potential_above, potential_below)
    -- If ImGuiBackendFlags.HasParentViewport if set, ->ParentViewport chain should be accurate.
    local g = GImGui
    if bit32.band(g.IO.BackendFlags, ImGuiBackendFlags.HasParentViewport) ~= 0 then
        local v = potential_above --[[@as ImGuiViewport]]
        while v ~= nil and v.ParentViewport do
            if v.ParentViewport == potential_below then
                return true
            end
            v = v.ParentViewport
        end
    else
        if potential_above.ParentViewport == potential_below then
            return true
        end
    end

    if potential_above.LastFocusedStampCount > potential_below.LastFocusedStampCount then
        return true
    end
    return false
end

--- @param window       ImGuiWindow
--- @param viewport_dst ImGuiViewportP
function ImGui.UpdateTryMergeWindowIntoHostViewport(window, viewport_dst)
    local g = GImGui
    IM_ASSERT(window == window.RootWindowDockTree)

    local viewport_src = window.Viewport -- Current viewport
    if viewport_src == viewport_dst then
        return false
    end
    if bit32.band(viewport_dst.Flags, ImGuiViewportFlags.CanHostOtherWindows) == 0 then
        return false
    end
    if bit32.band(viewport_dst.Flags, ImGuiViewportFlags.IsMinimized) ~= 0 then
        return false
    end
    if not viewport_dst:GetMainRect():Contains(window:Rect()) then
        return false
    end
    if ImGui.GetWindowAlwaysWantOwnViewport(window) then
        return false
    end

    for _, viewport_obstructing in g.Viewports:iter() do
        repeat
        if viewport_obstructing == viewport_src or viewport_obstructing == viewport_dst or not viewport_obstructing.PlatformWindowCreated then
            break
        end

        if viewport_obstructing:GetMainRect():Overlaps(window:Rect()) then
            if ImGui.IsViewportAbove(viewport_obstructing, viewport_dst) then
                if viewport_src == nil or ImGui.IsViewportAbove(viewport_src, viewport_obstructing) then
                    return false  -- viewport_obstructing is between viewport_src and viewport_dst -> Cannot merge.
                end
            end
        end

        until true
    end

    -- Move to the existing viewport, Move child/hosted windows as well (FIXME-OPT: iterate child)
    IMGUI_DEBUG_LOG_VIEWPORT("[viewport] Window '%s' merge into Viewport 0X%08X", window.Name, viewport_dst.ID)
    if window.ViewportOwned then
        for n = 1, g.Windows.Size do
            if g.Windows.Data[n].Viewport == viewport_src then
                ImGui.SetWindowViewport(g.Windows.Data[n], viewport_dst)
            end
        end
    end

    ImGui.SetWindowViewport(window, viewport_dst)

    if bit32.band(window.Flags, ImGuiWindowFlags.NoBringToFrontOnFocus) == 0 then
        ImGui.BringWindowToDisplayFront(window)
    end

    return true
end

-- FIXME: handle 0 to N host viewports
--- @param window ImGuiWindow
--- @return bool
function ImGui.UpdateTryMergeWindowIntoHostViewports(window)
    local g = GImGui
    return ImGui.UpdateTryMergeWindowIntoHostViewport(window, g.Viewports.Data[1])
end

-- Translate Dear ImGui windows when a Host Viewport has been moved
-- (This additionally keeps windows at the same place when ImGuiConfigFlags.ViewportsEnable is toggled!)
--- @param viewport ImGuiViewportP
--- @param old_pos  ImVec2
--- @param new_pos  ImVec2
--- @param old_size ImVec2
--- @param new_size ImVec2
function ImGui.TranslateWindowsInViewport(viewport, old_pos, new_pos, old_size, new_size)
    local g = GImGui
    -- IMGUI_DEBUG_LOG_VIEWPORT("[viewport] TranslateWindowsInViewport 0x%08X", viewport.ID)
    IM_ASSERT(viewport.Window == nil and (bit32.band(viewport.Flags, ImGuiViewportFlags.CanHostOtherWindows) ~= 0))

    -- 1) We test if ImGuiConfigFlags.ViewportsEnable was just toggled, which allows us to conveniently
    -- translate imgui windows from OS-window-local to absolute coordinates or vice-versa.
    -- 2) If it's not going to fit into the new size, keep it at same absolute position.
    -- One problem with this is that most Win32 applications doesn't update their render while dragging,
    -- and so the window will appear to teleport when releasing the mouse.
    local translate_all_windows = (bit32.band(g.ConfigFlagsCurrFrame, ImGuiConfigFlags.ViewportsEnable) ~= bit32.band(g.ConfigFlagsLastFrame, ImGuiConfigFlags.ViewportsEnable))
    local test_still_fit_rect = ImRect(old_pos, old_pos + old_size)
    local delta_pos = new_pos - old_pos

    for _, window in g.Windows:iter() do  -- FIXME-OPT
        if translate_all_windows or (window.Viewport == viewport and (old_size == new_size or test_still_fit_rect:Contains(window:Rect()))) then
            ImGui.TranslateWindow(window, delta_pos)
        end
    end
end

-- If the backend doesn't support ImGuiBackendFlags.HasMouseHoveredViewport or doesn't honor ImGuiViewportFlags.NoInputs for it, we do a search ourselves.
-- A) It won't take account of the possibility that non-imgui windows may be in-between our dragged window and our target window.
-- B) It requires Platform_GetWindowFocus to be implemented by backend.
--- @param mouse_platform_pos ImVec2
--- @return ImGuiViewportP?
function ImGui.FindHoveredViewportFromPlatformWindowStack(mouse_platform_pos)
    local g = GImGui
    local best_candidate = nil
    for _, viewport in g.Viewports:iter() do
        if bit32.band(viewport.Flags, bit32.bor(ImGuiViewportFlags.NoInputs, ImGuiViewportFlags.IsMinimized)) == 0 and viewport:GetMainRect():Contains(mouse_platform_pos) then
            if best_candidate == nil or best_candidate.LastFocusedStampCount < viewport.LastFocusedStampCount then
                if viewport.PlatformWindowCreated then
                    best_candidate = viewport
                end
            end
        end
    end
    return best_candidate
end

-- Update viewports and monitor infos
-- Note that this is running even if 'ImGuiConfigFlags.ViewportsEnable' is not set, in order to clear unused viewports (if any) and update monitor info.
function ImGui.UpdateViewportsNewFrame()
    local g = GImGui
    IM_ASSERT(g.PlatformIO.Viewports.Size <= g.Viewports.Size)

    -- Update Minimized status (we need it first in order to decide if we'll apply Pos/Size of the main viewport)
    -- Update Focused status
    local viewports_enabled = (bit32.band(g.ConfigFlagsCurrFrame, ImGuiConfigFlags.ViewportsEnable) ~= 0)
    if viewports_enabled then
        local focused_viewport = nil

        for i = 1, g.Viewports.Size do
            local viewport = g.Viewports.Data[i]
            local platform_funcs_available = viewport.PlatformWindowCreated

            if g.PlatformIO.Platform_GetWindowMinimized and platform_funcs_available then
                local is_minimized = g.PlatformIO.Platform_GetWindowMinimized(viewport)
                if is_minimized then
                    viewport.Flags = bit32.bor(viewport.Flags, ImGuiViewportFlags.IsMinimized)
                else
                    viewport.Flags = bit32.band(viewport.Flags, bit32.bnot(ImGuiViewportFlags.IsMinimized))
                end
            end

            -- Update our implicit z-order knowledge of platform windows, which is used when the backend cannot provide io.MouseHoveredViewport.
            -- When setting Platform_GetWindowFocus, it is expected that the platform backend can handle calls without crashing if it doesn't have data stored.
            if g.PlatformIO.Platform_GetWindowFocus and platform_funcs_available then
                local is_focused = g.PlatformIO.Platform_GetWindowFocus(viewport)
                if is_focused then
                    viewport.Flags = bit32.bor(viewport.Flags, ImGuiViewportFlags.IsFocused)
                else
                    viewport.Flags = bit32.band(viewport.Flags, bit32.bnot(ImGuiViewportFlags.IsFocused))
                end
                if is_focused then
                    focused_viewport = viewport
                end
            end
        end

        -- Focused viewport has changed?
        if focused_viewport and g.PlatformLastFocusedViewportId ~= focused_viewport.ID then
            IMGUI_DEBUG_LOG_VIEWPORT("[viewport] Focused viewport changed %08X -> %08X '%s', attempting to apply our focus.", g.PlatformLastFocusedViewportId, focused_viewport.ID, focused_viewport.Window and focused_viewport.Window.Name or "n/a")
            local prev_focused_viewport = ImGui.FindViewportByID(g.PlatformLastFocusedViewportId)
            local prev_focused_has_been_destroyed = (prev_focused_viewport == nil) or (not prev_focused_viewport.PlatformWindowCreated)

            -- Store a tag so we can infer z-order easily from all our windows
            -- We compare PlatformLastFocusedViewportId so newly created viewports with _NoFocusOnAppearing flag
            -- will keep the front most stamp instead of losing it back to their parent viewport.
            if focused_viewport.LastFocusedStampCount ~= g.ViewportFocusedStampCount then
                g.ViewportFocusedStampCount = g.ViewportFocusedStampCount + 1
                focused_viewport.LastFocusedStampCount = g.ViewportFocusedStampCount
            end
            g.PlatformLastFocusedViewportId = focused_viewport.ID

            -- Focus associated dear imgui window
            -- - if focus didn't happen with a click within imgui boundaries, e.g. Clicking platform title bar. (#6299)
            -- - if focus didn't happen because we destroyed another window (#6462)
            -- FIXME: perhaps 'FocusTopMostWindowUnderOne()' can handle the 'focused_window.Window ~= nil' case as well.
            local apply_imgui_focus_on_focused_viewport = not ImGui.IsAnyMouseDown() and not prev_focused_has_been_destroyed
            if apply_imgui_focus_on_focused_viewport and g.IO.ConfigViewportsPlatformFocusSetsImGuiFocus then
                focused_viewport.LastFocusedHadNavWindow = focused_viewport.LastFocusedHadNavWindow or (g.NavWindow ~= nil and g.NavWindow.Viewport == focused_viewport)  -- Update so a window changing viewport won't lose focus.

                local focus_request_flags = bit32.bor(ImGuiFocusRequestFlags.UnlessBelowModal, ImGuiFocusRequestFlags.RestoreFocusedChild)
                if focused_viewport.Window ~= nil then
                    ImGui.FocusWindow(focused_viewport.Window, focus_request_flags)
                elseif focused_viewport.LastFocusedHadNavWindow then
                    ImGui.FocusTopMostWindowUnderOne(nil, nil, focused_viewport, focus_request_flags)  -- Focus top most in viewport
                else
                    ImGui.FocusWindow(nil, focus_request_flags)  -- No window had focus last time viewport was focused
                end
            end
        end

        if focused_viewport then
            focused_viewport.LastFocusedHadNavWindow = (g.NavWindow ~= nil) and (g.NavWindow.Viewport == focused_viewport)
        end
    end

    -- Create/update main viewport with current platform position.
    -- FIXME-VIEWPORT: Size is driven by backend/user code for backward-compatibility but we should aim to make this more consistent.
    local main_viewport = g.Viewports.Data[1]
    IM_ASSERT(main_viewport.ID == IMGUI_VIEWPORT_DEFAULT_ID)
    IM_ASSERT(main_viewport.Window == nil)

    local main_viewport_pos
    if viewports_enabled then
        main_viewport_pos = g.PlatformIO.Platform_GetWindowPos(main_viewport)
    else
        main_viewport_pos = ImVec2(0.0, 0.0)
    end
    local main_viewport_size = g.IO.DisplaySize
    local main_viewport_framebuffer_scale = g.IO.DisplayFramebufferScale

    if viewports_enabled and (bit32.band(main_viewport.Flags, ImGuiViewportFlags.IsMinimized) ~= 0) then
        ImVec2_Copy(main_viewport_pos, main_viewport.Pos) -- Preserve last pos/size when minimized (FIXME: We don't do the same for Size outside of the viewport path)
        ImVec2_Copy(main_viewport_size, main_viewport.Size)
        main_viewport_framebuffer_scale = main_viewport.FramebufferScale
    end

    ImGui.AddUpdateViewport(nil, IMGUI_VIEWPORT_DEFAULT_ID, main_viewport_pos, main_viewport_size, bit32.bor(ImGuiViewportFlags.OwnedByApp, ImGuiViewportFlags.CanHostOtherWindows))

    local memory_compact_start_time = (g.GcCompactAll or g.IO.ConfigMemoryCompactTimer < 0.0) and FLT_MAX or (g.Time - g.IO.ConfigMemoryCompactTimer)

    g.CurrentDpiScale = 0.0
    g.CurrentViewport = nil
    g.MouseViewport = nil

    local n = 1
    while n <= g.Viewports.Size do
        local viewport = g.Viewports.Data[n]
        viewport.Idx = n

        -- Erase unused viewports
        if n > 1 and viewport.LastFrameActive < g.FrameCount - 2 then
            ImGui.DestroyViewport(viewport)
            -- n stays the same because we removed an element
        else
            local platform_funcs_available = viewport.PlatformWindowCreated

            if viewports_enabled then
                -- Update Position and Size (from Platform Window to ImGui) if requested.
                -- We do it early in the frame instead of waiting for UpdatePlatformWindows() to avoid a frame of lag when moving/resizing using OS facilities.
                if (bit32.band(viewport.Flags, ImGuiViewportFlags.IsMinimized) == 0) and platform_funcs_available then
                    -- Viewport->WorkPos and WorkSize will be updated below
                    if viewport.PlatformRequestMove then
                        ImVec2_Copy(viewport.Pos, g.PlatformIO.Platform_GetWindowPos(viewport))
                        ImVec2_Copy(viewport.LastPlatformPos, viewport.Pos)
                    end
                    if viewport.PlatformRequestResize then
                        viewport.Size = g.PlatformIO.Platform_GetWindowSize(viewport)
                        ImVec2_Copy(viewport.LastPlatformSize, viewport.Size)
                    end
                    if g.PlatformIO.Platform_GetWindowFramebufferScale ~= nil then
                        viewport.FramebufferScale = g.PlatformIO.Platform_GetWindowFramebufferScale(viewport)
                    end
                end
            end

            -- Update/copy monitor info
            ImGui.UpdateViewportPlatformMonitor(viewport)

            -- Lock down space taken by menu bars and status bars + query initial insets from backend
            -- Setup initial value for functions like BeginMainMenuBar(), DockSpaceOverViewport() etc.
            viewport.WorkInsetMin = viewport.BuildWorkInsetMin
            viewport.WorkInsetMax = viewport.BuildWorkInsetMax
            viewport.BuildWorkInsetMin = ImVec2(0.0, 0.0)
            viewport.BuildWorkInsetMax = ImVec2(0.0, 0.0)

            if g.PlatformIO.Platform_GetWindowWorkAreaInsets ~= nil and platform_funcs_available then
                local insets = g.PlatformIO.Platform_GetWindowWorkAreaInsets(viewport)
                IM_ASSERT(insets.x >= 0.0 and insets.y >= 0.0 and insets.z >= 0.0 and insets.w >= 0.0)
                viewport.BuildWorkInsetMin = ImVec2(insets.x, insets.y)
                viewport.BuildWorkInsetMax = ImVec2(insets.z, insets.w)
            end

            viewport:UpdateWorkRect()

            -- Garbage collect transient buffers of recently BG/FG drawlists
            for dl_n = 1, 2 do -- IM_COUNTOF(viewport->BgFgDrawLists)
                if viewport.BgFgDrawListsLastTimeActive[dl_n] < memory_compact_start_time and viewport.BgFgDrawLists[dl_n] ~= nil then
                    IM_DELETE(viewport.BgFgDrawLists, dl_n)
                end
            end

            -- Reset alpha every frame. Users of transparency (docking) needs to request a lower alpha back.
            viewport.Alpha = 1.0

            -- Translate Dear ImGui windows when a Host Viewport has been moved
            -- (This additionally keeps windows at the same place when ImGuiConfigFlags.ViewportsEnable is toggled!)
            local viewport_delta_pos = viewport.Pos - viewport.LastPos
            if (bit32.band(viewport.Flags, ImGuiViewportFlags.CanHostOtherWindows) ~= 0) and (viewport_delta_pos.x ~= 0.0 or viewport_delta_pos.y ~= 0.0) then
                ImGui.TranslateWindowsInViewport(viewport, viewport.LastPos, viewport.Pos, viewport.LastSize, viewport.Size)
            end

            -- Update DPI scale
            local new_dpi_scale
            if g.PlatformIO.Platform_GetWindowDpiScale and platform_funcs_available then
                new_dpi_scale = g.PlatformIO.Platform_GetWindowDpiScale(viewport)
            elseif viewport.PlatformMonitor ~= -1 then
                new_dpi_scale = g.PlatformIO.Monitors.Data[viewport.PlatformMonitor].DpiScale
            else
                new_dpi_scale = (viewport.DpiScale ~= 0.0) and viewport.DpiScale or 1.0
            end

            IM_ASSERT(new_dpi_scale > 0.0 and new_dpi_scale < 99.0)  -- Typical correct values would be between 1.0f and 4.0f

            if viewport.DpiScale ~= 0.0 and new_dpi_scale ~= viewport.DpiScale then
                local scale_factor = new_dpi_scale / viewport.DpiScale
                if g.IO.ConfigDpiScaleViewports then
                    ImGui.ScaleWindowsInViewport(viewport, scale_factor)
                end
                -- if viewport == ImGui.GetMainViewport() then
                --     g.PlatformInterface.SetWindowSize(viewport, viewport.Size * scale_factor)
                -- end

                -- Scale our window moving pivot so that the window will rescale roughly around the mouse position.
                -- FIXME-VIEWPORT: This currently creates a resizing feedback loop when a window is straddling a DPI transition border.
                -- (Minor: since our sizes do not perfectly linearly scale, deferring the click offset scale until we know the actual window scale ratio may get us slightly more precise mouse positioning.)
                -- if g.MovingWindow ~= nil and g.MovingWindow.Viewport == viewport then
                --     g.ActiveIdClickOffset = ImTrunc(g.ActiveIdClickOffset * scale_factor)
                -- end
            end

            viewport.DpiScale = new_dpi_scale
            n = n + 1
        end
    end

    -- Update fallback monitor
    g.PlatformMonitorsFullWorkRect = ImRect(FLT_MAX, FLT_MAX, -FLT_MAX, -FLT_MAX)

    if g.PlatformIO.Monitors.Size == 0 then
        local monitor = g.FallbackMonitor
        ImVec2_Copy(monitor.MainPos, main_viewport.Pos)
        ImVec2_Copy(monitor.MainSize, main_viewport.Size)
        ImVec2_Copy(monitor.WorkPos, main_viewport.WorkPos)
        ImVec2_Copy(monitor.WorkSize, main_viewport.WorkSize)
        monitor.DpiScale = main_viewport.DpiScale

        g.PlatformMonitorsFullWorkRect:Add(monitor.WorkPos)
        g.PlatformMonitorsFullWorkRect:Add(monitor.WorkPos + monitor.WorkSize)
    else
        g.FallbackMonitor = g.PlatformIO.Monitors.Data[1]
    end

    for i = 1, g.PlatformIO.Monitors.Size do
        local monitor = g.PlatformIO.Monitors.Data[i]
        g.PlatformMonitorsFullWorkRect:Add(monitor.WorkPos)
        g.PlatformMonitorsFullWorkRect:Add(monitor.WorkPos + monitor.WorkSize)
    end

    if not viewports_enabled then
        g.MouseViewport = main_viewport
        return
    end

    -- Mouse handling: decide on the actual mouse viewport for this frame between the active/focused viewport and the hovered viewport.
    -- Note that 'viewport_hovered' should skip over any viewport that has the ImGuiViewportFlags.NoInputs flags set.
    local viewport_hovered = nil

    if bit32.band(g.IO.BackendFlags, ImGuiBackendFlags.HasMouseHoveredViewport) ~= 0 then
        viewport_hovered = g.IO.MouseHoveredViewport and ImGui.FindViewportByID(g.IO.MouseHoveredViewport) or nil
        if viewport_hovered and (bit32.band(viewport_hovered.Flags, ImGuiViewportFlags.NoInputs) ~= 0) then
            viewport_hovered = ImGui.FindHoveredViewportFromPlatformWindowStack(g.IO.MousePos)  -- Backend failed to handle _NoInputs viewport: revert to our fallback.
        end
    else
        -- If the backend doesn't know how to honor ImGuiViewportFlags.NoInputs, we do a search ourselves. Note that this search:
        -- A) won't take account of the possibility that non-imgui windows may be in-between our dragged window and our target window.
        -- B) won't take account of how the backend apply parent<>child relationship to secondary viewports, which affects their Z order.
        -- C) uses LastFocusedStampCount as a flawed replacement for the last time a window was focused (we could/should fix that by introducing Focus functions in PlatformIO)
        viewport_hovered = ImGui.FindHoveredViewportFromPlatformWindowStack(g.IO.MousePos)
    end

    if viewport_hovered ~= nil then
        g.MouseLastHoveredViewport = viewport_hovered
    elseif g.MouseLastHoveredViewport == nil then
        g.MouseLastHoveredViewport = g.Viewports.Data[1]
    end

    -- Update mouse reference viewport
    -- (when moving a window we aim at its viewport, but this will be overwritten below if we go in drag and drop mode)
    -- (MovingViewport->Viewport will be nil in the rare situation where the window disappared while moving, set UpdateMouseMovingWindowNewFrame() for details)
    if g.MovingWindow and g.MovingWindow.Viewport then
        g.MouseViewport = g.MovingWindow.Viewport
    else
        g.MouseViewport = g.MouseLastHoveredViewport
    end

    -- When dragging something, always refer to the last hovered viewport.
    -- - when releasing a moving window we will revert to aiming behind (at viewport_hovered)
    -- - when we are between viewports, our dragged preview will tend to show in the last viewport _even_ if we don't have tooltips in their viewports (when lacking monitor info)
    -- - consider the case of holding on a menu item to browse child menus: even thou a mouse button is held, there's no active id because menu items only react on mouse release.
    -- FIXME-VIEWPORT: This is essentially broken, when ImGuiBackendFlags.HasMouseHoveredViewport is set we want to trust when viewport_hovered==nil and use that.
    local is_mouse_dragging_with_an_expected_destination = g.DragDropActive
    if is_mouse_dragging_with_an_expected_destination and viewport_hovered == nil then
        viewport_hovered = g.MouseLastHoveredViewport
    end

    if is_mouse_dragging_with_an_expected_destination or g.ActiveId == 0 or not ImGui.IsAnyMouseDown() then
        if viewport_hovered ~= nil and viewport_hovered ~= g.MouseViewport and (bit32.band(viewport_hovered.Flags, ImGuiViewportFlags.NoInputs) == 0) then
            g.MouseViewport = viewport_hovered
        end
    end

    IM_ASSERT(g.MouseViewport ~= nil)
end

-- Update user-facing viewport list (g.Viewports -> g.PlatformIO.Viewports after filtering out some)
function ImGui.UpdateViewportsEndFrame()
    local g = GImGui
    g.PlatformIO.Viewports:resize(0)

    for i = 1, g.Viewports.Size do
        repeat
        local viewport = g.Viewports.Data[i]
        ImVec2_Copy(viewport.LastPos, ImVec2(viewport.Pos.x, viewport.Pos.y))
        ImVec2_Copy(viewport.LastSize, ImVec2(viewport.Size.x, viewport.Size.y))

        if (viewport.LastFrameActive < g.FrameCount or viewport.Size.x <= 0.0 or viewport.Size.y <= 0.0) and (i > 1) then -- Always include main viewport in the list
            break
        end
        if viewport.Window and not ImGui.IsWindowActiveAndVisible(viewport.Window) then
            break
        end
        if i > 1 then
            IM_ASSERT(viewport.Window ~= nil)
        end
        g.PlatformIO.Viewports:push_back(viewport)

        until true
    end

    g.Viewports.Data[1]:ClearRequestFlags()  -- Clear main viewport flags because UpdatePlatformWindows() won't do it and may not even be called
end

-- FIXME: We should ideally refactor the system to call this every frame (we currently don't)
--- @param window? ImGuiWindow
--- @param id      ImGuiID
--- @param pos     ImVec2
--- @param size    ImVec2
--- @param flags   ImGuiViewportFlags
--- @return ImGuiViewportP
function ImGui.AddUpdateViewport(window, id, pos, size, flags)
    local g = GImGui
    IM_ASSERT(id ~= 0)

    flags = bit32.bor(flags, ImGuiViewportFlags.IsPlatformWindow)
    if window ~= nil then
        local window_can_use_inputs = (bit32.band(window.Flags, bit32.bor(ImGuiWindowFlags.NoMouseInputs, ImGuiWindowFlags.NoNavInputs)) == 0)
        if g.MovingWindow and g.MovingWindow.RootWindowDockTree == window then
            flags = bit32.bor(flags, ImGuiViewportFlags.NoInputs, ImGuiViewportFlags.NoFocusOnAppearing)
        end
        if not window_can_use_inputs then
            flags = bit32.bor(flags, ImGuiViewportFlags.NoInputs)
        end
        if bit32.band(window.Flags, ImGuiWindowFlags.NoFocusOnAppearing) ~= 0 then
            flags = bit32.bor(flags, ImGuiViewportFlags.NoFocusOnAppearing)
        end
    end

    local viewport = ImGui.FindViewportByID(id)
    if viewport then
        --- @cast viewport ImGuiViewportP

        -- Always update for main viewport as we are already pulling correct platform pos/size (see #4900)
        local prev_pos = ImVec2(viewport.Pos.x, viewport.Pos.y)
        local prev_size = ImVec2(viewport.Size.x, viewport.Size.y)
        if not viewport.PlatformRequestMove or viewport.ID == IMGUI_VIEWPORT_DEFAULT_ID then
            ImVec2_Copy(viewport.Pos, pos)
        end
        if not viewport.PlatformRequestResize or viewport.ID == IMGUI_VIEWPORT_DEFAULT_ID then
            ImVec2_Copy(viewport.Size, size)
        end
        viewport.Flags = bit32.bor(flags, bit32.band(viewport.Flags, bit32.bor(ImGuiViewportFlags.IsMinimized, ImGuiViewportFlags.IsFocused))) -- Preserve existing flags
        if prev_pos.x ~= viewport.Pos.x or prev_pos.y ~= viewport.Pos.y or prev_size.x ~= viewport.Size.x or prev_size.y ~= viewport.Size.y then
            ImGui.UpdateViewportPlatformMonitor(viewport)
        end
    else
        -- New viewport
        viewport = ImGuiViewportP()
        viewport.ID = id
        viewport.Idx = g.Viewports.Size
        ImVec2_Copy(viewport.Pos, pos)
        ImVec2_Copy(viewport.LastPos, pos)
        ImVec2_Copy(viewport.Size, size)
        ImVec2_Copy(viewport.LastSize, size)
        viewport.Flags = flags
        ImGui.UpdateViewportPlatformMonitor(viewport)
        g.Viewports:push_back(viewport)
        g.ViewportCreatedCount = g.ViewportCreatedCount + 1
        IMGUI_DEBUG_LOG_VIEWPORT("[viewport] Add Viewport %08X '%s'", id, window and window.Name or "<NULL>")

        -- We assume the window becomes front-most (even when ImGuiViewportFlags.NoFocusOnAppearing is used).
        -- This is useful for our platform z-order heuristic when io.MouseHoveredViewport is not available.
        g.ViewportFocusedStampCount = g.ViewportFocusedStampCount + 1
        viewport.LastFocusedStampCount = g.ViewportFocusedStampCount

        -- We normally setup for all viewports in NewFrame() but here need to handle the mid-frame creation of a new viewport.
        -- We need to extend the fullscreen clip rect so the OverlayDrawList clip is correct for that the first frame
        g.DrawListSharedData.ClipRectFullscreen.x = ImMin(g.DrawListSharedData.ClipRectFullscreen.x, viewport.Pos.x)
        g.DrawListSharedData.ClipRectFullscreen.y = ImMin(g.DrawListSharedData.ClipRectFullscreen.y, viewport.Pos.y)
        g.DrawListSharedData.ClipRectFullscreen.z = ImMax(g.DrawListSharedData.ClipRectFullscreen.z, viewport.Pos.x + viewport.Size.x)
        g.DrawListSharedData.ClipRectFullscreen.w = ImMax(g.DrawListSharedData.ClipRectFullscreen.w, viewport.Pos.y + viewport.Size.y)

        -- Store initial DpiScale before the OS platform window creation, based on expected monitor data.
        -- This is so we can select an appropriate font size on the first frame of our window lifetime
        viewport.DpiScale = ImGui.GetViewportPlatformMonitor(viewport).DpiScale
    end

    viewport.Window = window
    viewport.LastFrameActive = g.FrameCount
    viewport:UpdateWorkRect()
    IM_ASSERT(window == nil or viewport.ID == window.ID)

    if window ~= nil then
        window.ViewportOwned = true
    end

    return viewport
end

--- @param viewport ImGuiViewportP
function ImGui.DestroyViewport(viewport)
    -- Clear references to this viewport in windows (window->ViewportId becomes the master data)
    local g = GImGui
    for i = 1, g.Windows.Size do
        local window = g.Windows.Data[i]
        if window.Viewport == viewport then
            window.Viewport = nil
            window.ViewportOwned = false
        end
    end

    if viewport == g.MouseLastHoveredViewport then
        g.MouseLastHoveredViewport = nil
    end

    -- Destroy
    IMGUI_DEBUG_LOG_VIEWPORT("[viewport] Delete Viewport %08X '%s'", viewport.ID, viewport.Window and viewport.Window.Name or "n/a")
    ImGui.DestroyPlatformWindow(viewport)  -- In most circumstances the platform window will already be destroyed here.
    IM_ASSERT(not g.PlatformIO.Viewports:contains(viewport))
    IM_ASSERT(g.Viewports.Data[viewport.Idx] == viewport)
    g.Viewports:erase(viewport.Idx)
    -- IM_DELETE(viewport)
end

-- FIXME-VIEWPORT: This is all super messy and ought to be clarified or rewritten.
--- @param window ImGuiWindow
function ImGui.WindowSelectViewport(window)
    local g = GImGui
    local flags = window.Flags
    window.ViewportAllowPlatformMonitorExtend = -1

    -- Restore main viewport if multi-viewport is not supported by the backend
    local main_viewport = ImGui.GetMainViewport() --[[@as ImGuiViewportP]]
    if bit32.band(g.ConfigFlagsCurrFrame, ImGuiConfigFlags.ViewportsEnable) == 0 then
        ImGui.SetWindowViewport(window, main_viewport)
        return
    end
    window.ViewportOwned = false

    -- Appearing popups reset their viewport so they can inherit again
    if bit32.band(flags, bit32.bor(ImGuiWindowFlags.Popup, ImGuiWindowFlags.Tooltip)) ~= 0 and window.Appearing then
        window.Viewport = nil
        window.ViewportId = 0
    end

    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasViewport) == 0 then
        -- By default inherit from parent window
        if window.Viewport == nil and window.ParentWindow and (not window.ParentWindow.IsFallbackWindow or window.ParentWindow.WasActive) then
            window.Viewport = window.ParentWindow.Viewport
        end

        -- Attempt to restore saved viewport id (= window that hasn't been activated yet), try to restore the viewport based on saved 'window->ViewportPos' restored from .ini file
        if window.Viewport == nil and window.ViewportId ~= 0 then
            window.Viewport = ImGui.FindViewportByID(window.ViewportId) --[[@as ImGuiViewportP]]
            if window.Viewport == nil and window.ViewportPos.x ~= FLT_MAX and window.ViewportPos.y ~= FLT_MAX then
                window.Viewport = ImGui.AddUpdateViewport(window, window.ID, window.ViewportPos, window.Size, ImGuiViewportFlags.None)
            end
        end
    end

    local lock_viewport = false
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasViewport) ~= 0 then
        -- Code explicitly request a viewport
        window.Viewport = ImGui.FindViewportByID(g.NextWindowData.ViewportId) --[[@as ImGuiViewportP]]
        window.ViewportId = g.NextWindowData.ViewportId  -- Store ID even if Viewport isn't resolved yet.
        if window.Viewport and bit32.band(window.Flags, ImGuiWindowFlags.DockNodeHost) ~= 0 and window.Viewport.Window ~= nil then
            window.Viewport.Window = window
            window.Viewport.ID = window.ID
            window.ViewportId = window.ID  -- Overwrite ID (always owned by node)
        end
        lock_viewport = true
    elseif bit32.band(flags, ImGuiWindowFlags.ChildWindow) ~= 0 or bit32.band(flags, ImGuiWindowFlags.ChildMenu) ~= 0 then
        -- Always inherit viewport from parent window
        if window.DockNode and window.DockNode.HostWindow then
            IM_ASSERT(window.DockNode.HostWindow.Viewport == window.ParentWindow.Viewport)
        end
        window.Viewport = window.ParentWindow.Viewport
    elseif window.DockNode and window.DockNode.HostWindow then
        -- This covers the "always inherit viewport from parent window" case for when a window reattach to a node that was just created mid-frame
        window.Viewport = window.DockNode.HostWindow.Viewport
    elseif bit32.band(flags, ImGuiWindowFlags.Tooltip) ~= 0 then
        window.Viewport = g.MouseViewport
    elseif ImGui.GetWindowAlwaysWantOwnViewport(window) then
        window.Viewport = ImGui.AddUpdateViewport(window, window.ID, window.Pos, window.Size, ImGuiViewportFlags.None)
    elseif g.MovingWindow and g.MovingWindow.RootWindowDockTree == window and ImGui.IsMousePosValid() then
        if window.Viewport ~= nil and window.Viewport.Window == window then
            window.Viewport = ImGui.AddUpdateViewport(window, window.ID, window.Pos, window.Size, ImGuiViewportFlags.None)
        end
    else
        -- Merge into host viewport?
        -- We cannot test window->ViewportOwned as it set lower in the function.
        -- Testing (g.ActiveId == 0 || g.ActiveIdAllowOverlap) to avoid merging during a short-term widget interaction. Main intent was to avoid during resize (see #4212)
        local try_to_merge_into_host_viewport = (window.Viewport and window == window.Viewport.Window and (g.ActiveId == 0 or g.ActiveIdAllowOverlap))
        if try_to_merge_into_host_viewport then
            ImGui.UpdateTryMergeWindowIntoHostViewports(window)
        end
    end

    -- Fallback: merge in default viewport if z-order matches, otherwise create a new viewport
    if window.Viewport == nil then
        --- @cast main_viewport ImGuiViewportP
        if not ImGui.UpdateTryMergeWindowIntoHostViewport(window, main_viewport) then
            window.Viewport = ImGui.AddUpdateViewport(window, window.ID, window.Pos, window.Size, ImGuiViewportFlags.None)
        end
    end

    -- Mark window as allowed to protrude outside of its viewport and into the current monitor
    if not lock_viewport then
        if bit32.band(flags, bit32.bor(ImGuiWindowFlags.Tooltip, ImGuiWindowFlags.Popup)) ~= 0 then
            -- We need to take account of the possibility that mouse may become invalid.
            -- Popups/Tooltip always set ViewportAllowPlatformMonitorExtend so GetWindowAllowedExtentRect() will return full monitor bounds.
            local mouse_ref = bit32.band(flags, ImGuiWindowFlags.Tooltip) ~= 0 and g.IO.MousePos or g.BeginPopupStack.Data[g.BeginPopupStack.Size].OpenMousePos
            local use_mouse_ref = not g.NavCursorVisible or not g.NavHighlightItemUnderNav or not g.NavWindow
            local mouse_valid = ImGui.IsMousePosValid(mouse_ref)
            if (window.Appearing or bit32.band(flags, bit32.bor(ImGuiWindowFlags.Tooltip, ImGuiWindowFlags.ChildMenu)) ~= 0) and (not use_mouse_ref or mouse_valid) then
                local pos_to_use = (use_mouse_ref and mouse_valid) and mouse_ref or ImGui.NavCalcPreferredRefPos(window.Flags)
                window.ViewportAllowPlatformMonitorExtend = ImGui.FindPlatformMonitorForPos(pos_to_use)
            else
                window.ViewportAllowPlatformMonitorExtend = window.Viewport.PlatformMonitor
            end
        elseif window.Viewport and window ~= window.Viewport.Window and window.Viewport.Window and bit32.band(flags, ImGuiWindowFlags.ChildWindow) == 0 and window.DockNode == nil then
            -- When called from Begin() we don't have access to a proper version of the Hidden flag yet, so we replicate this code.
            local will_be_visible = (window.DockIsActive and not window.DockTabIsVisible) and false or true
            if bit32.band(window.Flags, ImGuiWindowFlags.DockNodeHost) ~= 0 and window.Viewport.LastFrameActive < g.FrameCount and will_be_visible then
                -- Steal/transfer ownership
                IMGUI_DEBUG_LOG_VIEWPORT("[viewport] Window '%s' steal Viewport %08X from Window '%s'", window.Name, window.Viewport.ID, window.Viewport.Window.Name)
                window.Viewport.Window = window
                window.Viewport.ID = window.ID
                window.Viewport.LastNameHash = 0
            elseif not ImGui.UpdateTryMergeWindowIntoHostViewports(window) then  -- Merge?
                -- New viewport
                window.Viewport = ImGui.AddUpdateViewport(window, window.ID, window.Pos, window.Size, ImGuiViewportFlags.NoFocusOnAppearing)
            end
        elseif window.ViewportAllowPlatformMonitorExtend < 0 and bit32.band(flags, ImGuiWindowFlags.ChildWindow) == 0 then
            -- Regular (non-child, non-popup) windows by default are also allowed to protrude
            -- Child windows are kept contained within their parent.
            window.ViewportAllowPlatformMonitorExtend = window.Viewport.PlatformMonitor
        end
    end

    -- Update flags
    window.ViewportOwned = (window == window.Viewport.Window)
    window.ViewportId = window.Viewport.ID

    -- If the OS window has a title bar, hide our imgui title bar
    -- if window.ViewportOwned and bit32.band(window.Viewport.Flags, ImGuiViewportFlags.NoDecoration) == 0 then
    --     window.Flags = bit32.bor(window.Flags, ImGuiWindowFlags.NoTitleBar)
    -- end
end

--- @param window                  ImGuiWindow
--- @param parent_window_in_stack? ImGuiWindow
function ImGui.WindowSyncOwnedViewport(window, parent_window_in_stack)
    local g = GImGui
    local viewport_rect_changed = false

    -- Synchronize window --> viewport in most situations
    -- Synchronize viewport -> window in case the platform window has been moved or resized from the OS/WM
    if window.Viewport.PlatformRequestMove then
        ImVec2_Copy(window.Pos, window.Viewport.Pos)
        -- ImGui.MarkIniSettingsDirty(window)
    elseif window.Viewport.Pos.x ~= window.Pos.x or window.Viewport.Pos.y ~= window.Pos.y then
        viewport_rect_changed = true
        ImVec2_Copy(window.Viewport.Pos, window.Pos)
    end

    if window.Viewport.PlatformRequestResize then
        ImVec2_Copy(window.Size, window.Viewport.Size)
        ImVec2_Copy(window.SizeFull, window.Viewport.Size)
        -- ImGui.MarkIniSettingsDirty(window)
    elseif window.Viewport.Size.x ~= window.Size.x or window.Viewport.Size.y ~= window.Size.y then
        viewport_rect_changed = true
        ImVec2_Copy(window.Viewport.Size, window.Size)
    end
    window.Viewport:UpdateWorkRect()

    -- The viewport may have changed monitor since the global update in UpdateViewportsNewFrame()
    -- Either a SetNextWindowPos() call in the current frame or a SetWindowPos() call in the previous frame may have this effect.
    if viewport_rect_changed then
        ImGui.UpdateViewportPlatformMonitor(window.Viewport)
    end

    -- Update common viewport flags
    local viewport_flags_to_clear = bit32.bor(ImGuiViewportFlags.TopMost, ImGuiViewportFlags.NoTaskBarIcon, ImGuiViewportFlags.NoDecoration, ImGuiViewportFlags.NoRendererClear)
    local viewport_flags = bit32.band(window.Viewport.Flags, bit32.bnot(viewport_flags_to_clear))
    local window_flags = window.Flags
    local is_modal = bit32.band(window_flags, ImGuiWindowFlags.Modal) ~= 0
    local is_short_lived_floating_window = bit32.band(window_flags, bit32.bor(ImGuiWindowFlags.ChildMenu, ImGuiWindowFlags.Tooltip, ImGuiWindowFlags.Popup)) ~= 0

    if bit32.band(window_flags, ImGuiWindowFlags.Tooltip) ~= 0 then
        viewport_flags = bit32.bor(viewport_flags, ImGuiViewportFlags.TopMost)
    end

    if (g.IO.ConfigViewportsNoTaskBarIcon or is_short_lived_floating_window) and not is_modal then
        viewport_flags = bit32.bor(viewport_flags, ImGuiViewportFlags.NoTaskBarIcon)
    end

    if g.IO.ConfigViewportsNoDecoration or is_short_lived_floating_window then
        viewport_flags = bit32.bor(viewport_flags, ImGuiViewportFlags.NoDecoration)
    end

    -- Not correct to set modal as topmost because:
    -- - Because other popups can be stacked above a modal (e.g. combo box in a modal)
    -- - ImGuiViewportFlags.TopMost is currently handled different in backends: in Win32 it is "appear top most" whereas in GLFW and SDL it is "stay topmost"
    -- if bit32.band(window_flags, ImGuiWindowFlags.Modal) ~= 0 then
    --     viewport_flags = bit32.bor(viewport_flags, ImGuiViewportFlags.TopMost)
    -- end

    -- For popups and menus that may be protruding out of their parent viewport, we enable _NoFocusOnClick so that clicking on them
    -- won't steal the OS focus away from their parent window (which may be reflected in OS the title bar decoration).
    -- Setting _NoFocusOnClick would technically prevent us from bringing back to front in case they are being covered by an OS window from a different app,
    -- but it shouldn't be much of a problem considering those are already popups that are closed when clicking elsewhere.
    if is_short_lived_floating_window and not is_modal then
        viewport_flags = bit32.bor(viewport_flags, ImGuiViewportFlags.NoFocusOnAppearing, ImGuiViewportFlags.NoFocusOnClick)
    end

    -- We can overwrite viewport flags using ImGuiWindowClass (advanced users)
    if window.WindowClass.ViewportFlagsOverrideSet ~= 0 then
        viewport_flags = bit32.bor(viewport_flags, window.WindowClass.ViewportFlagsOverrideSet)
    end
    if window.WindowClass.ViewportFlagsOverrideClear ~= 0 then
        viewport_flags = bit32.band(viewport_flags, bit32.bnot(window.WindowClass.ViewportFlagsOverrideClear))
    end

    -- We can also tell the backend that clearing the platform window won't be necessary,
    -- as our window background is filling the viewport and we have disabled BgAlpha.
    -- FIXME: Work on support for per-viewport transparency (#2766)
    if bit32.band(window_flags, ImGuiWindowFlags.NoBackground) == 0 then
        viewport_flags = bit32.bor(viewport_flags, ImGuiViewportFlags.NoRendererClear)
    end

    window.Viewport.Flags = viewport_flags

    -- Update parent viewport ID
    -- (the !IsFallbackWindow test mimic the one done in WindowSelectViewport())
    if window.WindowClass.ParentViewportId ~= 0xFFFFFFFF then
        local old_parent_viewport_id = window.Viewport.ParentViewportId
        window.Viewport.ParentViewportId = window.WindowClass.ParentViewportId
        if window.Viewport.ParentViewportId ~= old_parent_viewport_id then
            window.Viewport.ParentViewport = ImGui.FindViewportByID(window.Viewport.ParentViewportId) --[[@as ImGuiViewport]]
        end
    elseif bit32.band(window_flags, bit32.bor(ImGuiWindowFlags.Popup, ImGuiWindowFlags.Tooltip)) ~= 0 and parent_window_in_stack and (not parent_window_in_stack.IsFallbackWindow or parent_window_in_stack.WasActive) then
        window.Viewport.ParentViewport = parent_window_in_stack.Viewport
        window.Viewport.ParentViewportId = parent_window_in_stack.Viewport.ID
    else
        if g.IO.ConfigViewportsNoDefaultParent then
            window.Viewport.ParentViewport = nil
        else
            window.Viewport.ParentViewport = ImGui.GetMainViewport()
        end
        window.Viewport.ParentViewportId = g.IO.ConfigViewportsNoDefaultParent and 0 or IMGUI_VIEWPORT_DEFAULT_ID
    end
end

-- Called by user at the end of the main loop, after EndFrame()
-- This will handle the creation/update of all OS windows via function defined in the ImGuiPlatformIO api.
function ImGui.UpdatePlatformWindows()
    local g = GImGui
    IM_ASSERT(g.FrameCountEnded == g.FrameCount, "Forgot to call Render() or EndFrame() before UpdatePlatformWindows()?")
    IM_ASSERT(g.FrameCountPlatformEnded < g.FrameCount)
    g.FrameCountPlatformEnded = g.FrameCount
    if bit32.band(g.ConfigFlagsCurrFrame, ImGuiConfigFlags.ViewportsEnable) == 0 then
        return
    end

    -- Create/resize/destroy platform windows to match each active viewport.
    -- Skip the main viewport (index 0), which is always fully handled by the application!
    for i = 2, g.Viewports.Size do
        repeat
        local viewport = g.Viewports.Data[i]

        -- Destroy platform window if the viewport hasn't been submitted or if it is hosting a hidden window
        -- (the implicit/fallback Debug##Default window will be registering its viewport then be disabled, causing a dummy DestroyPlatformWindow to be made each frame)
        local destroy_platform_window = false
        destroy_platform_window = destroy_platform_window or (viewport.LastFrameActive < g.FrameCount - 1)
        destroy_platform_window = destroy_platform_window or (viewport.Window and not ImGui.IsWindowActiveAndVisible(viewport.Window)) --[[@as bool]]
        if destroy_platform_window then
            ImGui.DestroyPlatformWindow(viewport)
            break
        end

        -- New windows that appears directly in a new viewport won't always have a size on their first frame
        if viewport.LastFrameActive < g.FrameCount or viewport.Size.x <= 0 or viewport.Size.y <= 0 then
            break
        end

        -- Create window
        local is_new_platform_window = not viewport.PlatformWindowCreated
        if is_new_platform_window then
            IMGUI_DEBUG_LOG_VIEWPORT("[viewport] Create Platform Window %08X '%s'", viewport.ID, viewport.Window and viewport.Window.Name or "n/a")
            g.PlatformIO.Platform_CreateWindow(viewport)
            if g.PlatformIO.Renderer_CreateWindow ~= nil then
                g.PlatformIO.Renderer_CreateWindow(viewport)
            end
            g.PlatformWindowsCreatedCount = g.PlatformWindowsCreatedCount + 1
            viewport.LastNameHash = 0
            ImVec2_CopyV(viewport.LastPlatformPos, FLT_MAX, FLT_MAX)
            ImVec2_CopyV(viewport.LastPlatformSize, FLT_MAX, FLT_MAX) -- By clearing those we'll enforce a call to Platform_SetWindowPos/Size below, before Platform_ShowWindow (FIXME: Is that necessary?)
            ImVec2_Copy(viewport.LastRendererSize, viewport.Size)     -- We don't need to call Renderer_SetWindowSize() as it is expected Renderer_CreateWindow() already did it.
            viewport.PlatformWindowCreated = true
        end

        -- Apply Position and Size (from ImGui to Platform/Renderer backends)
        if (viewport.LastPlatformPos.x ~= viewport.Pos.x or viewport.LastPlatformPos.y ~= viewport.Pos.y) and not viewport.PlatformRequestMove then
            g.PlatformIO.Platform_SetWindowPos(viewport, viewport.Pos)
        end
        if (viewport.LastPlatformSize.x ~= viewport.Size.x or viewport.LastPlatformSize.y ~= viewport.Size.y) and not viewport.PlatformRequestResize then
            g.PlatformIO.Platform_SetWindowSize(viewport, viewport.Size)
        end
        if (viewport.LastRendererSize.x ~= viewport.Size.x or viewport.LastRendererSize.y ~= viewport.Size.y) and g.PlatformIO.Renderer_SetWindowSize ~= nil then
            g.PlatformIO.Renderer_SetWindowSize(viewport, viewport.Size)
        end
        ImVec2_Copy(viewport.LastPlatformPos, viewport.Pos)
        ImVec2_Copy(viewport.LastPlatformSize, viewport.Size)
        ImVec2_Copy(viewport.LastRendererSize, viewport.Size)

        -- Update title bar (if it changed)
        local window_for_title = GetWindowForTitleDisplay(viewport.Window)
        if window_for_title ~= nil then
            local title = window_for_title.Name
            local title_begin = 1
            local title_end = ImGui.FindRenderedTextEnd(title)
            local title_hash = ImHashStr(title, title_end - title_begin)
            if viewport.LastNameHash ~= title_hash then
                -- This still creates new strings
                g.PlatformIO.Platform_SetWindowTitle(viewport, string.sub(title, title_begin, title_end - 1))
                viewport.LastNameHash = title_hash
            end
        end

        -- Update alpha (if it changed)
        if viewport.LastAlpha ~= viewport.Alpha and g.PlatformIO.Platform_SetWindowAlpha ~= nil then
            g.PlatformIO.Platform_SetWindowAlpha(viewport, viewport.Alpha)
        end
        viewport.LastAlpha = viewport.Alpha

        -- Optional, general purpose call to allow the backend to perform general book-keeping even if things haven't changed.
        if g.PlatformIO.Platform_UpdateWindow ~= nil then
            g.PlatformIO.Platform_UpdateWindow(viewport)
        end

        if is_new_platform_window then
            -- On startup ensure new platform window don't steal focus (give it a few frames, as nested contents may lead to viewport being created a few frames late)
            if g.FrameCount < 3 then
                viewport.Flags = bit32.bor(viewport.Flags, ImGuiViewportFlags.NoFocusOnAppearing)
            end

            -- Show window
            g.PlatformIO.Platform_ShowWindow(viewport)
        end

        -- Clear request flags
        viewport:ClearRequestFlags()

        until true
    end
end

-- This is a default/basic function for performing the rendering/swap of multiple Platform Windows.
-- Custom renderers may prefer to not call this function at all, and instead iterate the publicly exposed platform data and handle rendering/sync themselves.
-- The Render/Swap functions stored in ImGuiPlatformIO are merely here to allow for this helper to exist, but you can do it yourself:
--
--    local platform_io = ImGui.GetPlatformIO()
--    for i = 2, platform_io.Viewports.Size do
--        if bit32.band(platform_io.Viewports.Data[i].Flags, ImGuiViewportFlags.IsMinimized) == 0 then
--            MyRenderFunction(platform_io.Viewports.Data[i], my_args)
--        end
--    end
--    for i = 2, platform_io.Viewports.Size do
--        if bit32.band(platform_io.Viewports.Data[i].Flags, ImGuiViewportFlags.IsMinimized) == 0 then
--            MySwapBufferFunction(platform_io.Viewports.Data[i], my_args)
--        end
--    end
--
function ImGui.RenderPlatformWindowsDefault(platform_render_arg, renderer_render_arg)
    -- Skip the main viewport (index 1 in Lua), which is always fully handled by the application!
    local platform_io = ImGui.GetPlatformIO()

    -- First pass: render all windows
    for i = 2, platform_io.Viewports.Size do
        local viewport = platform_io.Viewports.Data[i]
        if bit32.band(viewport.Flags, ImGuiViewportFlags.IsMinimized) == 0 then
            if platform_io.Platform_RenderWindow then
                platform_io.Platform_RenderWindow(viewport, platform_render_arg)
            end
            if platform_io.Renderer_RenderWindow then
                platform_io.Renderer_RenderWindow(viewport, renderer_render_arg)
            end
        end
    end

    -- Second pass: swap buffers for all windows
    for i = 2, platform_io.Viewports.Size do
        local viewport = platform_io.Viewports.Data[i]
        if bit32.band(viewport.Flags, ImGuiViewportFlags.IsMinimized) == 0 then
            if platform_io.Platform_SwapBuffers then
                platform_io.Platform_SwapBuffers(viewport, platform_render_arg)
            end
            if platform_io.Renderer_SwapBuffers then
                platform_io.Renderer_SwapBuffers(viewport, renderer_render_arg)
            end
        end
    end
end

--- @param pos ImVec2
function ImGui.FindPlatformMonitorForPos(pos)
    local g = GImGui
    for monitor_n = 1, g.PlatformIO.Monitors.Size do
        local monitor = g.PlatformIO.Monitors.Data[monitor_n]
        if ImRect(monitor.MainPos, monitor.MainPos + monitor.MainSize):Contains(pos) then
            return monitor_n
        end
    end
    return -1
end

-- Search for the monitor with the largest intersection area with the given rectangle
-- We generally try to avoid searching loops but the monitor count should be very small here
-- FIXME-OPT: We could test the last monitor used for that viewport first, and early
--- @param rect ImRect
--- @return int
function ImGui.FindPlatformMonitorForRect(rect)
    local g = GImGui
    local monitor_count = g.PlatformIO.Monitors.Size

    if monitor_count <= 1 then
        return monitor_count
    end

    -- Use a minimum threshold of 1.0f so a zero-sized rect won't false positive, and will still find the correct monitor given its position.
    -- This is necessary for tooltips which always resize down to zero at first.
    local surface_threshold = math.max(rect:GetWidth() * rect:GetHeight() * 0.5, 1.0)
    local best_monitor_n = 1  -- Default to the first monitor as fallback
    local best_monitor_surface = 0.001

    for monitor_n = 1, g.PlatformIO.Monitors.Size do
        if best_monitor_surface >= surface_threshold then
            break
        end

        local monitor = g.PlatformIO.Monitors.Data[monitor_n]
        local monitor_rect = ImRect(monitor.MainPos, monitor.MainPos + monitor.MainSize)

        if monitor_rect:Contains(rect) then
            return monitor_n
        end

        local overlapping_rect = ImRect(rect.Min.x, rect.Min.y, rect.Max.x, rect.Max.y)
        overlapping_rect:ClipWithFull(monitor_rect)
        local overlapping_surface = overlapping_rect:GetWidth() * overlapping_rect:GetHeight()

        if overlapping_surface > best_monitor_surface then
            best_monitor_surface = overlapping_surface
            best_monitor_n = monitor_n
        end
    end

    return best_monitor_n
end

-- Update monitor from viewport rectangle (we'll use this info to clamp windows and save windows lost in a removed monitor)
--- @param viewport ImGuiViewportP
function ImGui.UpdateViewportPlatformMonitor(viewport)
    viewport.PlatformMonitor = ImGui.FindPlatformMonitorForRect(viewport:GetMainRect())
end

-- Return value is always ~= nil, but don't hold on it across frames.
--- @param viewport_p ImGuiViewport
--- @return ImGuiPlatformMonitor
function ImGui.GetViewportPlatformMonitor(viewport_p)
    local g = GImGui
    local viewport = viewport_p --- @cast viewport ImGuiViewportP

    local monitor_idx = viewport.PlatformMonitor
    if monitor_idx >= 1 and monitor_idx <= g.PlatformIO.Monitors.Size then
        return g.PlatformIO.Monitors.Data[monitor_idx]
    end
    return g.FallbackMonitor
end

--- @param viewport ImGuiViewportP
function ImGui.DestroyPlatformWindow(viewport)
    local g = GImGui
    if viewport.PlatformWindowCreated then
        IMGUI_DEBUG_LOG_VIEWPORT("[viewport] Destroy Platform Window %08X '%s'", viewport.ID, viewport.Window and viewport.Window.Name or "n/a")
        if g.PlatformIO.Renderer_DestroyWindow then
            g.PlatformIO.Renderer_DestroyWindow(viewport)
        end
        if g.PlatformIO.Platform_DestroyWindow then
            g.PlatformIO.Platform_DestroyWindow(viewport)
        end
        IM_ASSERT(viewport.RendererUserData == nil and viewport.PlatformUserData == nil)

        -- Don't clear PlatformWindowCreated for the main viewport, as we initially set that up to true in Initialize()
        -- The righter way may be to leave it to the backend to set this flag all-together, and made the flag public.
        if viewport.ID ~= IMGUI_VIEWPORT_DEFAULT_ID then
            viewport.PlatformWindowCreated = false
        end
    else
        IM_ASSERT(viewport.RendererUserData == nil and viewport.PlatformUserData == nil and viewport.PlatformHandle == nil)
    end
    viewport.RendererUserData = nil
    viewport.PlatformUserData = nil
    viewport.PlatformHandle = nil
    viewport:ClearRequestFlags()
end

function ImGui.DestroyPlatformWindows()
    -- We call the destroy window on every viewport (including the main viewport, index 1) to give a chance to the backend
    -- to clear any data they may have stored in e.g. PlatformUserData, RendererUserData.
    -- It is convenient for the platform backend code to store something in the main viewport, in order for e.g. the mouse handling
    -- code to operator a consistent manner.
    -- It is expected that the backend can handle calls to Renderer_DestroyWindow/Platform_DestroyWindow without
    -- crashing if it doesn't have data stored.
    local g = GImGui
    for _, viewport in g.Viewports:iter() do
        ImGui.DestroyPlatformWindow(viewport)
    end
end

-------------------------------------------------------------------------------
-- [SECTION] METRICS/DEBUGGER WINDOW
-------------------------------------------------------------------------------
-- - DebugRenderViewportThumbnail() [Internal]
-- - RenderViewportsThumbnails() [Internal]
-------------------------------------------------------------------------------

--- @param draw_list ImDrawList
--- @param viewport  ImGuiViewport
--- @param bb        ImRect
function ImGui.DebugRenderViewportThumbnail(draw_list, viewport, bb)
    local g = GImGui
    local window = g.CurrentWindow

    local scale = bb:GetSize() / viewport.Size
    local off = bb.Min - viewport.Pos * scale
    local alpha_mul = (bit32.band(viewport.Flags, ImGuiViewportFlags.IsMinimized) ~= 0) and 0.30 or 1.00
    window.DrawList:AddRectFilled(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.Border, alpha_mul * 0.40))

    for _, thumb_window in g.Windows:iter() do
        repeat
        if not thumb_window.WasActive or bit32.band(thumb_window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0 then
            break
        end
        if thumb_window.Viewport ~= viewport then
            break
        end

        local thumb_r = thumb_window:Rect()
        local title_r = thumb_window:TitleBarRect()
        thumb_r = ImRect(ImTrunc(off + thumb_r.Min * scale), ImTrunc(off + thumb_r.Max * scale))
        title_r = ImRect(ImTrunc(off + title_r.Min * scale), ImTrunc(off + ImVec2(title_r.Max.x, title_r.Min.y + title_r:GetHeight() * 3.0) * scale)) -- Exaggerate title bar height
        thumb_r:ClipWithFull(bb)
        title_r:ClipWithFull(bb)
        local window_is_focused = g.NavWindow and thumb_window.RootWindowForTitleBarHighlight == g.NavWindow.RootWindowForTitleBarHighlight
        window.DrawList:AddRectFilled(thumb_r.Min, thumb_r.Max, ImGui.GetColorU32(ImGuiCol.WindowBg, alpha_mul))
        window.DrawList:AddRectFilled(title_r.Min, title_r.Max, ImGui.GetColorU32(window_is_focused and ImGuiCol.TitleBgActive or ImGuiCol.TitleBg, alpha_mul))
        window.DrawList:AddRect(thumb_r.Min, thumb_r.Max, ImGui.GetColorU32(ImGuiCol.Border, alpha_mul))
        window.DrawList:AddText(g.Font, g.FontSize * 1.0, title_r.Min, ImGui.GetColorU32(ImGuiCol.Text, alpha_mul), thumb_window.Name, 1, ImGui.FindRenderedTextEnd(thumb_window.Name))

        until true
    end

    draw_list:AddRect(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.Border, alpha_mul))
    if viewport.ID == g.DebugMetricsConfig.HighlightViewportID then
        window.DrawList:AddRect(bb.Min, bb.Max, IM_COL32(255, 255, 0, 255))
    end
end

function ImGui.RenderViewportsThumbnails()
    local g = GImGui
    local window = g.CurrentWindow

    -- Draw monitor and calculate their boundaries
    local SCALE = 1.0 / 8.0
    local bb_full = ImRect(FLT_MAX, FLT_MAX, -FLT_MAX, -FLT_MAX)
    for _, monitor in g.PlatformIO.Monitors:iter() do
        bb_full:Add(ImRect(monitor.MainPos, monitor.MainPos + monitor.MainSize))
    end

    local p = window.DC.CursorPos
    local off = p - bb_full.Min * SCALE
    for _, monitor in g.PlatformIO.Monitors:iter() do
        local monitor_draw_bb = ImRect(off + monitor.MainPos * SCALE, off + (monitor.MainPos + monitor.MainSize) * SCALE)
        window.DrawList:AddRect(monitor_draw_bb.Min, monitor_draw_bb.Max, (g.DebugMetricsConfig.HighlightMonitorIdx == g.PlatformIO.Monitors:index_from_ptr(monitor)) and IM_COL32(255, 255, 0, 255) or ImGui.GetColorU32(ImGuiCol.Border), 4.0)
        window.DrawList:AddRectFilled(monitor_draw_bb.Min, monitor_draw_bb.Max, ImGui.GetColorU32(ImGuiCol.Border, 0.10), 4.0)
    end

    -- Draw viewports
    for _, viewport in g.Viewports:iter() do
        local viewport_draw_bb = ImRect(off + viewport.Pos * SCALE, off + (viewport.Pos + viewport.Size) * SCALE)
        ImGui.DebugRenderViewportThumbnail(window.DrawList, viewport, viewport_draw_bb)
    end
    ImGui.Dummy(bb_full:GetSize() * SCALE)
end




--- @param idx ImGuiCol
--- @return ImVec4  # live reference to the style color (like upstream's const&)
function ImGui.GetStyleColorVec4(idx)
    return GImGui.Style.Colors[idx]
end

-- Until 1.89 (August 2022, IMGUI_VERSION_NUM < 18814) it was legal to use SetCursorPos()/SetCursorScreenPos()
-- to extend contents size of our parent container (e.g. window contents size, which is used for auto-resizing
-- windows, table column contents size used for auto-resizing columns, group size).
-- This was causing issues and ambiguities and we needed to retire that.
--
-- Advanced:
-- - For reference, old logic was causing issues because it meant that SetCursorScreenPos(GetCursorScreenPos())
--   had a side-effect on layout! In particular this caused problem to compute group boundaries.
--   e.g. BeginGroup() + SomeItem() + SetCursorScreenPos(GetCursorScreenPos()) + EndGroup() would cause the
--   group to be taller because auto-sizing generally adds padding on bottom and right side.
-- - While this code is a little twisted, no-one would expect SetXXX(GetXXX()) to have a side-effect.
--   Using vertical alignment patterns would frequently trigger this sorts of issue.
-- - See https://github.com/ocornut/imgui/issues/5548 for more details.
function ImGui.ErrorCheckUsingSetCursorPosToExtendParentBoundaries()
    local g = GImGui
    local window = g.CurrentWindow
    IM_ASSERT(window.DC.IsSetPos)
    window.DC.IsSetPos = false
    if window.DC.CursorPos.x <= window.DC.CursorMaxPos.x and window.DC.CursorPos.y <= window.DC.CursorMaxPos.y then return end
    if window.SkipItems then return end
    -- Upstream asserts (user error): "Code uses SetCursorPos()/SetCursorScreenPos() to extend window/parent boundaries.
    -- Please submit an item e.g. Dummy() afterwards". We keep the old, tolerant behavior instead of erroring.
    window.DC.CursorMaxPos = ImMax(window.DC.CursorMaxPos, window.DC.CursorPos)
end

-------------------------------------------------------------------------------
-- [SECTION] POPUPS: modals, context popups, dimming
-------------------------------------------------------------------------------

local function GetWindowDisplayLayer(window)
    return (bit32.band(window.Flags, ImGuiWindowFlags.Tooltip) ~= 0) and 1 or 0
end

--- @return int # 0-based display index (like upstream), -1 if not found
function ImGui.FindWindowDisplayIndex(window)
    local g = GImGui
    local i = g.Windows:find_index(window)
    return i and (i - 1) or -1
end

function ImGui.BringWindowToDisplayBack(window)
    local g = GImGui
    if g.Windows.Data[1] == window then return end
    local i = g.Windows:find_index(window)
    if i then
        table.remove(g.Windows.Data, i)
        table.insert(g.Windows.Data, 1, window)
    end
end

function ImGui.FindBottomMostVisibleWindowWithinBeginStack(parent_window)
    local g = GImGui
    local bottom_most_visible_window = parent_window
    for i = ImGui.FindWindowDisplayIndex(parent_window), 0, -1 do
        local window = g.Windows.Data[i + 1]
        if bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) == 0 then
            if not ImGui.IsWindowWithinBeginStackOf(window, parent_window) then break end
            if ImGui.IsWindowActiveAndVisible(window) and GetWindowDisplayLayer(window) <= GetWindowDisplayLayer(parent_window) then
                bottom_most_visible_window = window
            end
        end
    end
    return bottom_most_visible_window
end

-- See Demo->Stacked Modal to confirm what this is for.
function ImGui.GetTopMostAndVisiblePopupModal()
    local g = GImGui
    for n = g.OpenPopupStack.Size, 1, -1 do
        local popup = g.OpenPopupStack.Data[n].Window
        if popup and bit32.band(popup.Flags, ImGuiWindowFlags.Modal) ~= 0 and ImGui.IsWindowActiveAndVisible(popup) then
            return popup
        end
    end
    return nil
end

function ImGui.RenderDimmedBackgroundBehindWindow(window, col)
    if bit32.band(col, IM_COL32_A_MASK) == 0 then return end
    local viewport = window.Viewport
    local viewport_rect = viewport:GetMainRect()
    -- Draw behind window by moving the draw command at the FRONT of the draw list
    -- Draw list have been trimmed already, hence the explicit recreation of a draw command if missing.
    -- FIXME: This is a little bit complicated, solely to avoid creating/injecting an extra drawlist in drawdata.
    local draw_list = (window.RootWindowDockTree or window.RootWindow).DrawList
    draw_list:ChannelsMerge()
    if draw_list.CmdBuffer.Size == 0 then draw_list:AddDrawCmd() end
    draw_list:PushClipRect(viewport_rect.Min - ImVec2(1, 1), viewport_rect.Max + ImVec2(1, 1), false) -- FIXME: Need to strictly ensure ImDrawCmd are not merged
    draw_list:AddRectFilled(viewport_rect.Min, viewport_rect.Max, col)
    local cmd = draw_list.CmdBuffer.Data[draw_list.CmdBuffer.Size]
    draw_list.CmdBuffer:pop_back()
    draw_list.CmdBuffer:push_front(cmd)
    draw_list:AddDrawCmd() -- We need to create a command as CmdBuffer.back().IdxOffset won't be correct if we append to same command.
    draw_list:PopClipRect()
end

-- Important: AddWindowToDrawData() has not been called yet, meaning DockNodeHost windows needs a DrawList:ChannelsMerge() before usage.
-- We call ChannelsMerge() lazily here at it is faster that doing a full iteration of g.Windows[] prior to calling RenderDimmedBackgrounds().
function ImGui.RenderDimmedBackgrounds()
    local g = GImGui
    local modal_window = ImGui.GetTopMostAndVisiblePopupModal()
    if g.DimBgRatio <= 0.0 and g.NavWindowingHighlightAlpha <= 0.0 then return end
    local dim_bg_for_modal = (modal_window ~= nil)
    local dim_bg_for_window_list = (g.NavWindowingTargetAnim ~= nil and g.NavWindowingTargetAnim.Active)
    if not dim_bg_for_modal and not dim_bg_for_window_list then return end

    if dim_bg_for_modal then
        -- Draw dimming behind modal or a begin stack child, whichever comes first in draw order.
        local dim_behind_window = ImGui.FindBottomMostVisibleWindowWithinBeginStack(modal_window)
        ImGui.RenderDimmedBackgroundBehindWindow(dim_behind_window, ImGui.GetColorU32(modal_window.DC.ModalDimBgColor, g.DimBgRatio, true))
    elseif dim_bg_for_window_list then
        -- Draw dimming behind Ctrl+Tab target window and behind Ctrl+Tab UI window
        ImGui.RenderDimmedBackgroundBehindWindow(g.NavWindowingTargetAnim, ImGui.GetColorU32(ImGuiCol.NavWindowingDimBg, g.DimBgRatio))
        if g.NavWindowingListWindow ~= nil and g.NavWindowingListWindow.Active and g.NavWindowingListWindow.Viewport and g.NavWindowingListWindow.Viewport ~= g.NavWindowingTargetAnim.Viewport then
            ImGui.RenderDimmedBackgroundBehindWindow(g.NavWindowingListWindow, ImGui.GetColorU32(ImGuiCol.NavWindowingDimBg, g.DimBgRatio))
        end

        -- Draw border around Ctrl+Tab target window
        local window = g.NavWindowingTargetAnim
        local viewport = window.Viewport
        local distance = g.FontSize
        local bb = window:Rect()
        bb:Expand(distance)
        if bb:GetWidth() >= viewport.Size.x and bb:GetHeight() >= viewport.Size.y then bb:Expand(-distance - 1.0) end -- If a window fits the entire viewport, adjust its highlight inward
        window.DrawList:ChannelsMerge()
        if window.DrawList.CmdBuffer.Size == 0 then window.DrawList:AddDrawCmd() end
        window.DrawList:PushClipRect(viewport.Pos, viewport.Pos + viewport.Size)
        window.DrawList:AddRect(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.NavWindowingHighlight, g.NavWindowingHighlightAlpha), window.WindowRounding, 0, 3.0) -- FIXME-DPI
        window.DrawList:PopClipRect()
    end
end

function ImGui.ClosePopupsExceptModals()
    local g = GImGui
    local popup_count_to_keep = g.OpenPopupStack.Size
    while popup_count_to_keep > 0 do
        local window = g.OpenPopupStack.Data[popup_count_to_keep].Window
        if not window or bit32.band(window.Flags, ImGuiWindowFlags.Modal) ~= 0 then break end
        popup_count_to_keep = popup_count_to_keep - 1
    end
    if popup_count_to_keep < g.OpenPopupStack.Size then -- This test is not required but it allows to set a convenient breakpoint on the statement below
        ImGui.ClosePopupToLevel(popup_count_to_keep, true)
    end
end

-- If 'p_open' is specified for a modal popup window, the popup will have a regular close button which will close the popup.
-- Note that popup visibility status is owned by Dear ImGui (and manipulated with e.g. OpenPopup).
-- - p_open is returned set back to false by BeginPopupModal() when popup is not open.
-- - if you set p_open to false before calling BeginPopupModal(), it will close the popup.
--- @return bool visible, bool? p_open   # p_open is the updated value of the optional close button flag
function ImGui.BeginPopupModal(name, p_open, flags)
    if flags == nil then flags = 0 end
    local g = GImGui
    local window = g.CurrentWindow
    local id = window:GetID(name)
    if not ImGui.IsPopupOpen(id, ImGuiPopupFlags.None) then
        g.NextWindowData:ClearFlags() -- We behave like Begin() and need to consume those values
        if p_open then p_open = false end
        return false, p_open
    end

    -- Center modal windows by default for increased visibility
    -- (this won't really last as settings will kick in, and is mostly for backward compatibility. user may do the same themselves)
    -- FIXME: Should test for (PosCond & window.SetWindowPosAllowFlags) with the upcoming window.
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasPos) == 0 then
        local viewport = window.WasActive and window.Viewport or ImGui.GetMainViewport() -- FIXME-VIEWPORT: What may be our reference viewport?
        ImGui.SetNextWindowPos(viewport:GetCenter(), ImGuiCond.FirstUseEver, ImVec2(0.5, 0.5))
    end

    flags = bit32.bor(flags, ImGuiWindowFlags.Popup, ImGuiWindowFlags.Modal, ImGuiWindowFlags.NoCollapse, ImGuiWindowFlags.NoDocking)
    local is_open
    p_open, is_open = ImGui.Begin(name, p_open, flags)
    if not is_open or (p_open ~= nil and not p_open) then -- NB: is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
        ImGui.EndPopup()
        if is_open then ImGui.ClosePopupToLevel(g.BeginPopupStack.Size, true) end
        return false, p_open
    end
    return is_open, p_open
end

function ImGui.IsPopupOpenRequestForWindow(popup_flags)
    local g = GImGui
    local mouse_button = ImGui.GetMouseButtonFromPopupFlags(popup_flags)
    if ImGui.IsMouseReleased(mouse_button, ImGuiKeyOwner_NoOwner) and ImGui.IsWindowHovered(ImGuiHoveredFlags.AllowWhenBlockedByPopup) then
        if bit32.band(popup_flags, ImGuiPopupFlags.NoOpenOverItems) == 0 or not ImGui.IsAnyItemHovered() then
            return true
        end
    end
    if g.NavOpenContextMenuWindowId and g.NavOpenContextMenuWindowId ~= 0 and g.CurrentWindow.ID ~= 0 then
        if ImGui.IsWindowChildOf(g.NavWindow, g.CurrentWindow, false, false) then return true end -- This enable ordering to be used to disambiguate item vs window (#8803)
    end
    return false
end

function ImGui.BeginPopupContextWindow(str_id, popup_flags)
    if popup_flags == nil then popup_flags = 0 end
    local g = GImGui
    local window = g.CurrentWindow
    if not str_id then str_id = "window_context" end
    local id = window:GetID(str_id)
    if ImGui.IsPopupOpenRequestForWindow(popup_flags) then ImGui.OpenPopupEx(id, popup_flags) end
    return ImGui.BeginPopupEx(id, bit32.bor(ImGuiWindowFlags.AlwaysAutoResize, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoSavedSettings))
end

function ImGui.BeginPopupContextVoid(str_id, popup_flags)
    if popup_flags == nil then popup_flags = 0 end
    local g = GImGui
    local window = g.CurrentWindow
    if not str_id then str_id = "void_context" end
    local id = window:GetID(str_id) -- FIXME: Use a global ID?
    local mouse_button = ImGui.GetMouseButtonFromPopupFlags(popup_flags)
    if ImGui.IsMouseReleased(mouse_button, id) and not ImGui.IsWindowHovered(ImGuiHoveredFlags.AnyWindow) then
        if ImGui.GetTopMostPopupModal() == nil then ImGui.OpenPopupEx(id, popup_flags) end
    end
    return ImGui.BeginPopupEx(id, bit32.bor(ImGuiWindowFlags.AlwaysAutoResize, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoSavedSettings))
end

function ImGui.BeginTooltipHidden()
    local g = GImGui
    local _, ret = ImGui.Begin("##Tooltip_Hidden", nil, bit32.bor(ImGuiWindowFlags.Tooltip, ImGuiWindowFlags.NoInputs, ImGuiWindowFlags.NoTitleBar,
        ImGuiWindowFlags.NoMove, ImGuiWindowFlags.NoResize, ImGuiWindowFlags.NoSavedSettings, ImGuiWindowFlags.AlwaysAutoResize))
    ImGui.SetWindowHiddenAndSkipItemsForCurrentFrame(g.CurrentWindow)
    return ret
end

-------------------------------------------------------------------------------
-- [SECTION] MISC GETTERS/SETTERS, FOCUS
-------------------------------------------------------------------------------

function ImGui.NavMoveRequestResolveWithLastItem(result)
    local g = GImGui
    g.NavMoveScoringItems = false -- Ensure request doesn't need more processing
    ImGui.NavApplyItemToResult(result)
    ImGui.NavUpdateAnyRequestFlag()
end

-- Note: this will likely be called ActivateItem() once we rework our Focus/Activation system!
-- But ActivateItem() should function without altering scroll/focus?
function ImGui.SetKeyboardFocusHere(offset)
    if offset == nil then offset = 0 end
    local g = GImGui
    local window = g.CurrentWindow
    IM_ASSERT(offset >= -1) -- -1 is allowed but not below

    -- It makes sense in the vast majority of cases to never interrupt a drag and drop.
    -- When we refactor this function into ActivateItem() we may want to make this an option.
    -- MovingWindow is protected from most user inputs using SetActiveIdUsingNavAndKeys(), but
    -- is also automatically dropped in the event g.ActiveId is stolen.
    if g.DragDropActive or g.MovingWindow ~= nil then
        return
    end

    ImGui.SetNavWindow(window)

    local move_flags = bit32.bor(ImGuiNavMoveFlags.IsTabbing, ImGuiNavMoveFlags.Activate, ImGuiNavMoveFlags.FocusApi, ImGuiNavMoveFlags.NoSetNavCursorVisible)
    local scroll_flags = window.Appearing and bit32.bor(ImGuiScrollFlags.KeepVisibleEdgeX, ImGuiScrollFlags.AlwaysCenterY) or bit32.bor(ImGuiScrollFlags.KeepVisibleEdgeX, ImGuiScrollFlags.KeepVisibleEdgeY)
    ImGui.NavMoveRequestSubmit(ImGuiDir.None, (offset < 0) and ImGuiDir.Up or ImGuiDir.Down, move_flags, scroll_flags) -- FIXME-NAV: Once we refactor tabbing, add LegacyApi flag to not activate non-inputable.
    if offset == -1 then
        ImGui.NavMoveRequestResolveWithLastItem(g.NavMoveResultLocal)
    else
        g.NavTabbingDir = 1
        g.NavTabbingCounter = offset + 1
    end
end

-- Focus = move navigation cursor, set scrolling, set focus window.
function ImGui.FocusItem()
    local g = GImGui
    local window = g.CurrentWindow
    if g.DragDropActive or g.MovingWindow ~= nil then -- FIXME: Opt-in flags for this?
        return
    end
    local move_flags = bit32.bor(ImGuiNavMoveFlags.IsTabbing, ImGuiNavMoveFlags.FocusApi, ImGuiNavMoveFlags.NoSetNavCursorVisible, ImGuiNavMoveFlags.NoSelect)
    local scroll_flags = window.Appearing and bit32.bor(ImGuiScrollFlags.KeepVisibleEdgeX, ImGuiScrollFlags.AlwaysCenterY) or bit32.bor(ImGuiScrollFlags.KeepVisibleEdgeX, ImGuiScrollFlags.KeepVisibleEdgeY)
    ImGui.SetNavWindow(window)
    ImGui.NavMoveRequestSubmit(ImGuiDir.None, ImGuiDir.Up, move_flags, scroll_flags)
    ImGui.NavMoveRequestResolveWithLastItem(g.NavMoveResultLocal)
end

function ImGui.ActivateItemByID(id)
    local g = GImGui
    g.NavNextActivateId = id
    g.NavNextActivateFlags = ImGuiActivateFlags.None
end

function ImGui.SetNavCursorVisible(visible)
    local g = GImGui
    if g.NavWindow and bit32.band(g.NavWindow.Flags, ImGuiWindowFlags.NoNavInputs) ~= 0 then
        visible = false
    elseif g.IO.ConfigNavCursorVisibleAlways then
        visible = true
    end
    g.NavCursorVisible = visible
end

function ImGui.GetFrameCount() return GImGui.FrameCount end
function ImGui.GetStateStorage() return GImGui.CurrentWindow.DC.StateStorage end
function ImGui.SetStateStorage(tree)
    local window = GImGui.CurrentWindow
    window.DC.StateStorage = tree or window.StateStorage
end
function ImGui.SetNextFrameWantCaptureKeyboard(want) GImGui.WantCaptureKeyboardNextFrame = want and 1 or 0 end
function ImGui.SetNextFrameWantCaptureMouse(want) GImGui.WantCaptureMouseNextFrame = want and 1 or 0 end
function ImGui.GetVersion() return IMGUI_VERSION end

local StyleColorNames = nil
function ImGui.GetStyleColorName(idx)
    if StyleColorNames == nil then
        StyleColorNames = {}
        for k, v in pairs(ImGuiCol) do if k ~= "COUNT" then StyleColorNames[v] = k end end
    end
    return StyleColorNames[idx] or "Unknown"
end

-------------------------------------------------------------------------------
-- [SECTION] NAV END FRAME
-------------------------------------------------------------------------------

local NAV_WINDOWING_LIST_APPEAR_DELAY = 0.15

-- Window has already passed the IsWindowNavFocusable()
local function GetFallbackWindowNameForWindowingList(window)
    if bit32.band(window.Flags, ImGuiWindowFlags.Popup) ~= 0 then
        return "(Popup)"
    end
    if bit32.band(window.Flags, ImGuiWindowFlags.MenuBar) ~= 0 and window.Name == "##MainMenuBar" then
        return "(Main menu bar)"
    end
    if window.DockNodeAsHost then
        return "(Dock node)" -- Not normally shown to user.
    end
    return "(Untitled)"
end

-- Overlay displayed when using Ctrl+Tab. Called by EndFrame().
function ImGui.NavUpdateWindowingOverlay()
    local g = GImGui
    IM_ASSERT(g.NavWindowingTarget ~= nil)

    if g.NavWindowingTimer < NAV_WINDOWING_LIST_APPEAR_DELAY then
        return
    end

    local viewport = ImGui.GetMainViewport()
    ImGui.SetNextWindowSizeConstraints(ImVec2(viewport.Size.x * 0.20, viewport.Size.y * 0.20), ImVec2(FLT_MAX, FLT_MAX))
    ImGui.SetNextWindowPos(viewport:GetCenter(), ImGuiCond.Always, ImVec2(0.5, 0.5))
    ImGui.PushStyleVar(ImGuiStyleVar.WindowPadding, g.Style.WindowPadding * 2.0)
    ImGui.Begin("##NavWindowingOverlay", nil, bit32.bor(ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoFocusOnAppearing, ImGuiWindowFlags.NoResize, ImGuiWindowFlags.NoMove, ImGuiWindowFlags.NoInputs, ImGuiWindowFlags.AlwaysAutoResize, ImGuiWindowFlags.NoSavedSettings))
    g.NavWindowingListWindow = g.CurrentWindow
    for n = g.WindowsFocusOrder.Size, 1, -1 do
        local window = g.WindowsFocusOrder.Data[n]
        IM_ASSERT(window ~= nil) -- Fix static analyzers
        if ImGui.IsWindowNavFocusable(window) then
            local label = window.Name
            if ImGui.FindRenderedTextEnd(label) == 1 then
                label = GetFallbackWindowNameForWindowingList(window)
            end
            ImGui.Selectable(label, g.NavWindowingTarget == window)
        end
    end
    ImGui.End()
    ImGui.PopStyleVar()
end

local function NavUpdateCreateWrappingRequest()
    local g = GImGui
    local window = g.NavWindow

    local do_forward = false
    local src = window.NavRectRel[g.NavLayer]
    local bb_rel = ImRect(src.Min.x, src.Min.y, src.Max.x, src.Max.y)
    local clip_dir = g.NavMoveDir

    local move_flags = g.NavMoveFlags
    -- local move_axis = (g.NavMoveDir == ImGuiDir.Up or g.NavMoveDir == ImGuiDir.Down) and ImGuiAxis.Y or ImGuiAxis.X

    -- Menu layer does not maintain scrolling / content size (#9178)
    local wrap_size = (g.NavLayer == ImGuiNavLayer.Menu) and window.Size or (window.ContentSize + window.WindowPadding)

    if g.NavMoveDir == ImGuiDir.Left and bit32.band(move_flags, bit32.bor(ImGuiNavMoveFlags.WrapX, ImGuiNavMoveFlags.LoopX)) ~= 0 then
        bb_rel.Min.x = wrap_size.x; bb_rel.Max.x = wrap_size.x
        if bit32.band(move_flags, ImGuiNavMoveFlags.WrapX) ~= 0 then
            bb_rel:TranslateY(-bb_rel:GetHeight()) -- Previous row
            clip_dir = ImGuiDir.Up
        end
        do_forward = true
    end
    if g.NavMoveDir == ImGuiDir.Right and bit32.band(move_flags, bit32.bor(ImGuiNavMoveFlags.WrapX, ImGuiNavMoveFlags.LoopX)) ~= 0 then
        bb_rel.Min.x = -window.WindowPadding.x; bb_rel.Max.x = -window.WindowPadding.x
        if bit32.band(move_flags, ImGuiNavMoveFlags.WrapX) ~= 0 then
            bb_rel:TranslateY(bb_rel:GetHeight()) -- Next row
            clip_dir = ImGuiDir.Down
        end
        do_forward = true
    end
    if g.NavMoveDir == ImGuiDir.Up and bit32.band(move_flags, bit32.bor(ImGuiNavMoveFlags.WrapY, ImGuiNavMoveFlags.LoopY)) ~= 0 then
        bb_rel.Min.y = wrap_size.y; bb_rel.Max.y = wrap_size.y
        if bit32.band(move_flags, ImGuiNavMoveFlags.WrapY) ~= 0 then
            bb_rel:TranslateX(-bb_rel:GetWidth()) -- Previous column
            clip_dir = ImGuiDir.Left
        end
        do_forward = true
    end
    if g.NavMoveDir == ImGuiDir.Down and bit32.band(move_flags, bit32.bor(ImGuiNavMoveFlags.WrapY, ImGuiNavMoveFlags.LoopY)) ~= 0 then
        bb_rel.Min.y = -window.WindowPadding.y; bb_rel.Max.y = -window.WindowPadding.y
        if bit32.band(move_flags, ImGuiNavMoveFlags.WrapY) ~= 0 then
            bb_rel:TranslateX(bb_rel:GetWidth()) -- Next column
            clip_dir = ImGuiDir.Right
        end
        do_forward = true
    end
    if not do_forward then
        return
    end
    window.NavRectRel[g.NavLayer] = bb_rel
    ImGui.NavClearPreferredPosForAxis(ImGuiAxis.X)
    ImGui.NavClearPreferredPosForAxis(ImGuiAxis.Y)
    ImGui.NavMoveRequestForward(g.NavMoveDir, clip_dir, move_flags, g.NavMoveScrollFlags)
end

function ImGui.NavEndFrame()
    local g = GImGui

    -- Show Ctrl+Tab list window
    if g.NavWindowingTarget ~= nil then
        ImGui.NavUpdateWindowingOverlay()
    end

    -- Perform wrap-around in menus
    -- FIXME-NAV: Wrap may need to apply a weight bias on the other axis. e.g. 4x4 grid with 2 last items missing on last item won't handle LoopY/WrapY correctly.
    -- FIXME-NAV: Wrap (not Loop) support could be handled by the scoring function and then WrapX would function without an extra frame.
    if g.NavWindow and ImGui.NavMoveRequestButNoResultYet() and bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.WrapMask_) ~= 0 and bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.Forwarded) == 0 then
        NavUpdateCreateWrappingRequest()
    end
end

-------------------------------------------------------------------------------
-- [SECTION] ImGuiTextFilter
-------------------------------------------------------------------------------

--- @class ImGuiTextFilter
MT.ImGuiTextFilter = {}
MT.ImGuiTextFilter.__index = MT.ImGuiTextFilter

-- Helper: Parse and apply text filters e.g. 'aaa bbb -ccc'.
--- @param default_filter? string
function ImGuiTextFilter(default_filter)
    local this = setmetatable({ InputBuf = {}, _CountExclude = 0, _Items = ImVector() }, MT.ImGuiTextFilter)
    for i = 1, 256 do this.InputBuf[i] = 0 end
    if default_filter and default_filter ~= "" then
        for i = 1, ImMin(#default_filter, 255) do this.InputBuf[i] = string.byte(default_filter, i) end
        this:Build()
    end
    return this
end

function MT.ImGuiTextFilter:Draw(label, width)
    if label == nil then label = "Filter (inc,-exc)" end
    if width ~= nil and width ~= 0.0 then ImGui.SetNextItemWidth(width) end
    return self:DrawWithHint(label, "incl -excl")
end

-- Use ImGui.SetNextItemWidth() manually if you want to use this.
function MT.ImGuiTextFilter:DrawWithHint(label, hint)
    if label == nil then label = "Filter" end
    if hint == nil then hint = "incl -excl" end
    local value_changed = ImGui.InputTextWithHint(label, hint, self.InputBuf, 256)
    if value_changed then
        self:Build()
    end
    return value_changed
end

function MT.ImGuiTextFilter:Clear() self.InputBuf[1] = 0; self:Build() end
function MT.ImGuiTextFilter:IsActive() return self._Items.Size ~= 0 end

-- Parse filter and split into a format optimal for PassFilter()
-- Items are { Text = string (lowercased), CountInclude = int }
function MT.ImGuiTextFilter:Build()
    local items = self._Items
    items:resize(0)
    self._CountExclude = 0

    local n = 0
    while self.InputBuf[n + 1] ~= nil and self.InputBuf[n + 1] ~= 0 do n = n + 1 end
    local buf = ImGui._ByteArrayToString(self.InputBuf, 1, n + 1)
    local buf_e = n + 1 -- exclusive, 1-based
    local word_b = 1
    local seq_start_idx = -1 -- 1-based index into items, -1 = none
    while word_b < buf_e do
        -- Trim blanks
        while word_b < buf_e and ImCharIsBlankA(string.byte(buf, word_b)) do
            word_b = word_b + 1
        end
        local is_excl = word_b < buf_e and string.byte(buf, word_b) == 45 -- '-'
        if is_excl then word_b = word_b + 1 end
        local is_quote = word_b < buf_e and string.byte(buf, word_b) == 34 -- '"'
        local word_e
        if is_quote then
            -- Parsing quotes. Omit storing leading/trailing quotes.
            word_b = word_b + 1
            word_e = string.find(buf, '"', word_b, true) or buf_e
            if word_e > buf_e then word_e = buf_e end
        else
            -- Handle both ' ' and ',' separators.
            word_e = word_b
            while word_e < buf_e do
                local c = string.byte(buf, word_e)
                if c == 32 or c == 44 then break end
                word_e = word_e + 1
            end
        end

        -- Min length
        if word_e - word_b > 0 then
            -- Add to list. The '-' is not stored in items but implicitly inferred using (n < CountExclude).
            local item = { Text = string.lower(string.sub(buf, word_b, word_e - 1)), CountInclude = 0 }
            if is_excl then
                items:insert(self._CountExclude + 1, item)
                self._CountExclude = self._CountExclude + 1
                if seq_start_idx ~= -1 then seq_start_idx = seq_start_idx + 1 end
            else
                if seq_start_idx == -1 then seq_start_idx = items.Size + 1 end
                items:push_back(item)
                items.Data[seq_start_idx].CountInclude = items.Data[seq_start_idx].CountInclude + 1
            end
        end

        -- Next sequence
        if word_e < buf_e and string.byte(buf, word_e) == 44 then -- ','
            seq_start_idx = -1
        end
        word_b = word_e + 1
    end
end

-- FIXME: Could use a specialized ImStristr() + pre-convert our filter to uppercase.
--- @param text      string?
--- @param text_end? int     # exclusive, 1-based
function MT.ImGuiTextFilter:PassFilter(text, text_end)
    local items = self._Items
    if items.Size == 0 then return true end
    if text == nil then text = "" end
    if text_end ~= nil then text = string.sub(text, 1, text_end - 1) end
    text = string.lower(text)

    -- Filters are sorted so that '-' ones are always leading.
    local seq = 1
    local seq_excl_end = self._CountExclude + 1
    while seq < seq_excl_end do
        if string.find(text, items.Data[seq].Text, 1, true) then return false end
        seq = seq + 1
    end

    -- Process includes
    local seq_end = items.Size + 1
    if seq == seq_end then return true end -- When no inclusion are specified (only exclusions) we implicitly pass
    while seq < seq_end do
        local seq_incl_end = seq + items.Data[seq].CountInclude
        while seq < seq_incl_end do
            if not string.find(text, items.Data[seq].Text, 1, true) then break end
            seq = seq + 1
        end
        if seq == seq_incl_end then return true end -- All matched
        seq = seq_incl_end -- Try next
    end
    return false
end

-------------------------------------------------------------------------------
-- [SECTION] ImGuiListClipper
-------------------------------------------------------------------------------

ImGuiListClipperFlags = ImGuiListClipperFlags or { None = 0, NoSetTableRowCounters = bit32.lshift(1, 0) }

-- FIXME-TABLE: This prevents us from using ImGuiListClipper _inside_ a table cell.
-- The problem we have is that without a Begin/End scheme for rows using the clipper is ambiguous.
local function GetSkipItemForListClipping()
    local g = GImGui
    if g.CurrentTable then return g.CurrentTable.HostSkipItems end
    return g.CurrentWindow.SkipItems
end

local function ClipperRangeFromIndices(min, max) return { Min = min, Max = max, PosToIndexConvert = false, PosToIndexOffsetMin = 0, PosToIndexOffsetMax = 0 } end
local function ClipperRangeFromPositions(y1, y2, off_min, off_max) return { Min = y1, Max = y2, PosToIndexConvert = true, PosToIndexOffsetMin = off_min, PosToIndexOffsetMax = off_max } end

-- `offset` is a 0-based count of leading ranges to leave alone
local function ImGuiListClipper_SortAndFuseRanges(ranges, offset)
    if offset == nil then offset = 0 end
    if ranges.Size - offset <= 1 then return end
    local d = ranges.Data
    -- Helper to order ranges and fuse them together if possible (bubble sort is fine as we are only sorting 2-3 entries)
    for sort_end = ranges.Size - offset - 1, 1, -1 do
        for i = offset + 1, sort_end + offset do
            if d[i].Min > d[i + 1].Min then d[i], d[i + 1] = d[i + 1], d[i] end
        end
    end
    -- Now fuse ranges together as much as possible.
    local i = 2 + offset
    while i <= ranges.Size do
        IM_ASSERT(not d[i].PosToIndexConvert and not d[i - 1].PosToIndexConvert)
        if d[i - 1].Max < d[i].Min then
            i = i + 1
        else
            d[i - 1].Min = ImMin(d[i - 1].Min, d[i].Min)
            d[i - 1].Max = ImMax(d[i - 1].Max, d[i].Max)
            ranges:erase(i)
        end
    end
end

local function ImGuiListClipper_SeekCursorAndSetupPrevLine(clipper, pos_y, line_height)
    -- Set cursor position and a few other things so that SetScrollHereY() and Columns() can work when seeking cursor.
    -- FIXME: It is problematic that we have to do that here, because custom/equivalent end-user code would stumble on the same issue.
    -- The clipper should probably have a final step to display the last item in a regular manner, maybe with an opt-out flag for data sets which may have costly seek?
    local g = GImGui
    local window = g.CurrentWindow
    local off_y = pos_y - window.DC.CursorPos.y
    window.DC.CursorPos.y = pos_y
    window.DC.CursorMaxPos.y = ImMax(window.DC.CursorMaxPos.y, pos_y - g.Style.ItemSpacing.y)
    window.DC.CursorPosPrevLine.y = window.DC.CursorPos.y - line_height  -- Setting those fields so that SetScrollHereY() can properly function after the end of our clipper usage.
    window.DC.PrevLineSize.y = (line_height - g.Style.ItemSpacing.y)      -- If we end up needing more accurate data (to e.g. use SameLine) we may as well make the clipper have a fourth step to let user process and display the last item in their list.
    local columns = window.DC.CurrentColumns
    if columns then
        columns.LineMinY = window.DC.CursorPos.y -- Setting this so that cell Y position are set properly
    end
    local tbl = g.CurrentTable
    if tbl then
        if tbl.IsInsideRow then
            ImGui.TableEndRow(tbl)
        end
        local row_increase = math.floor((off_y / line_height) + 0.5)
        if row_increase > 0 and bit32.band(clipper.Flags, ImGuiListClipperFlags.NoSetTableRowCounters) == 0 then -- If your clipper item height is ~= from actual table row height, consider using ImGuiListClipperFlags.NoSetTableRowCounters. See #8886.
            tbl.CurrentRow = tbl.CurrentRow + row_increase
            tbl.RowBgColorCounter = tbl.RowBgColorCounter + row_increase
        end
        tbl.RowPosY2 = window.DC.CursorPos.y
    end
end

--- @class ImGuiListClipper
MT.ImGuiListClipper = {}
MT.ImGuiListClipper.__index = MT.ImGuiListClipper

function ImGuiListClipper()
    return setmetatable({ DisplayStart = 0, DisplayEnd = 0, UserIndex = 0, ItemsCount = 0, ItemsHeight = 0.0, Flags = 0,
        StartPosY = 0.0, StartSeekOffsetY = 0.0, Ctx = nil, TempData = nil }, MT.ImGuiListClipper)
end

--- @param items_count   int
--- @param items_height? float
function MT.ImGuiListClipper:Begin(items_count, items_height)
    if items_height == nil then items_height = -1.0 end
    self.Ctx = ImGui.GetCurrentContext()
    local g = self.Ctx
    local window = g.CurrentWindow

    local tbl = g.CurrentTable
    if tbl and tbl.IsInsideRow then
        ImGui.TableEndRow(tbl)
    end

    self.StartPosY = window.DC.CursorPos.y
    self.ItemsHeight = items_height
    self.ItemsCount = items_count
    self.DisplayStart = -1
    self.DisplayEnd = 0

    -- Acquire temporary buffer
    g.ClipperTempDataStacked = g.ClipperTempDataStacked + 1
    while g.ClipperTempDataStacked > g.ClipperTempData.Size do
        g.ClipperTempData:push_back({ ListClipper = nil, LossynessOffset = 0.0, StepNo = 0, ItemsFrozen = 0, Ranges = ImVector() })
    end
    local data = g.ClipperTempData.Data[g.ClipperTempDataStacked]
    data.ListClipper = self; data.StepNo = 0; data.ItemsFrozen = 0; data.Ranges:resize(0)
    data.LossynessOffset = window.DC.CursorStartPosLossyness.y
    self.TempData = data
    self.StartSeekOffsetY = data.LossynessOffset
end

function MT.ImGuiListClipper:End()
    local data = self.TempData
    if data then
        -- In theory here we should assert that we are already at the right position, but it seems saner to just seek at the end and not assert/crash the user.
        local g = self.Ctx
        if self.ItemsCount >= 0 and self.ItemsCount < INT_MAX and self.DisplayStart >= 0 then
            self:SeekCursorForItem(self.ItemsCount)
        end

        -- Restore temporary buffer and fix back pointers which may be invalidated when nesting
        IM_ASSERT(data.ListClipper == self)
        data.StepNo = data.Ranges.Size
        g.ClipperTempDataStacked = g.ClipperTempDataStacked - 1
        if g.ClipperTempDataStacked > 0 then
            data = g.ClipperTempData.Data[g.ClipperTempDataStacked]
            data.ListClipper.TempData = data
        end
        self.TempData = nil
    end
    self.DisplayStart = self.ItemsCount -- Clear this so code which may be reused past last Step() won't trip on a non-empty range.
    self.DisplayEnd = self.ItemsCount
    self.ItemsCount = -1
end

function MT.ImGuiListClipper:IncludeItemByIndex(item_index) self:IncludeItemsByIndex(item_index, item_index + 1) end

function MT.ImGuiListClipper:IncludeItemsByIndex(item_begin, item_end)
    local data = self.TempData
    IM_ASSERT(self.DisplayStart < 0) -- Only allowed after Begin() and if there has not been a specified range yet.
    IM_ASSERT(item_begin <= item_end)
    if item_begin < item_end then
        data.Ranges:push_back(ClipperRangeFromIndices(item_begin, item_end))
    end
end

-- This is already called while stepping.
-- The ONLY reason you may want to call this is if you passed INT_MAX to ImGuiListClipper:Begin() because you couldn't step item count beforehand.
function MT.ImGuiListClipper:SeekCursorForItem(item_n)
    -- - StartPosY starts from ItemsFrozen, by adding SeekOffsetY we generally cancel that out (SeekOffsetY == LossynessOffset - ItemsFrozen * ItemsHeight).
    -- - The reason we store SeekOffsetY instead of inferring it, is because we want to allow user to perform Seek after the last step, where ImGuiListClipperData is already done.
    local pos_y = self.StartPosY + self.StartSeekOffsetY + item_n * self.ItemsHeight
    ImGuiListClipper_SeekCursorAndSetupPrevLine(self, pos_y, self.ItemsHeight)
end

local function ImGuiListClipper_StepInternal(clipper)
    local g = clipper.Ctx
    local window = g.CurrentWindow
    local data = clipper.TempData
    IM_ASSERT(data ~= nil, "Called ImGuiListClipper::Step() too many times, or before ImGuiListClipper::Begin() ?")

    local tbl = g.CurrentTable
    if tbl and tbl.IsInsideRow then
        ImGui.TableEndRow(tbl)
    end

    -- No items
    if clipper.ItemsCount == 0 or GetSkipItemForListClipping() then
        return false
    end

    -- While we are in frozen row state, keep displaying items one by one, unclipped
    -- FIXME: Could be stored as a table-agnostic state.
    if data.StepNo == 0 and tbl ~= nil and not tbl.IsUnfrozenRows then
        clipper.DisplayStart = data.ItemsFrozen
        clipper.DisplayEnd = ImMin(data.ItemsFrozen + 1, clipper.ItemsCount)
        if clipper.DisplayStart < clipper.DisplayEnd then
            data.ItemsFrozen = data.ItemsFrozen + 1
        end
        return true
    end

    -- Step 0: Let you process the first element (regardless of it being visible or not, so we can measure the element height)
    local calc_clipping = false
    if data.StepNo == 0 then
        clipper.StartPosY = window.DC.CursorPos.y
        if clipper.ItemsHeight <= 0.0 then
            -- Submit the first item (or range) so we can measure its height (generally the first range is 0..1)
            data.Ranges:push_front(ClipperRangeFromIndices(data.ItemsFrozen, data.ItemsFrozen + 1))
            clipper.DisplayStart = ImMax(data.Ranges.Data[1].Min, data.ItemsFrozen)
            clipper.DisplayEnd = ImMin(data.Ranges.Data[1].Max, clipper.ItemsCount)
            data.StepNo = 1
            return true
        end
        calc_clipping = true -- If on the first step with known item height, calculate clipping.
    end

    -- Step 1: Let the clipper infer height from first range
    if clipper.ItemsHeight <= 0.0 then
        IM_ASSERT(data.StepNo == 1)
        -- (no float precision mitigation needed: Luau numbers are doubles)
        clipper.ItemsHeight = (window.DC.CursorPos.y - clipper.StartPosY) / (clipper.DisplayEnd - clipper.DisplayStart)
        if clipper.ItemsHeight == 0.0 and clipper.ItemsCount == INT_MAX then -- Accept that no item have been submitted if in indeterminate mode.
            return false
        end
        if clipper.ItemsHeight <= 0.0 then
            IM_ASSERT_USER_ERROR(clipper.ItemsHeight > 0.0, "ImGuiListClipper: Failed to calculate item height! First item hasn't been submitted by user code, or has not moved the cursor vertically!")
            return false
        end
        calc_clipping = true -- If item height had to be calculated, calculate clipping afterwards.
    end

    -- Step 0 or 1: Calculate the actual ranges of visible elements.
    local already_submitted = clipper.DisplayEnd
    if calc_clipping then
        -- Record seek offset, this is so ImGuiListClipper:Seek() can be called after ImGuiListClipperData is done
        clipper.StartSeekOffsetY = data.LossynessOffset - data.ItemsFrozen * clipper.ItemsHeight

        if g.LogEnabled then
            -- If logging is active, do not perform any clipping
            data.Ranges:push_back(ClipperRangeFromIndices(0, clipper.ItemsCount))
        else
            -- Add range selected to be included for navigation
            local is_nav_request = (g.NavMoveScoringItems and g.NavWindow and g.NavWindow.RootWindowForNav == window.RootWindowForNav) and true or false
            local nav_off_min = (is_nav_request and g.NavMoveClipDir == ImGuiDir.Up) and -1 or 0
            local nav_off_max = (is_nav_request and g.NavMoveClipDir == ImGuiDir.Down) and 1 or 0
            if is_nav_request then
                data.Ranges:push_back(ClipperRangeFromPositions(g.NavScoringRect.Min.y, g.NavScoringRect.Max.y, nav_off_min, nav_off_max))
                if not g.NavScoringNoClipRect:IsInverted() then
                    data.Ranges:push_back(ClipperRangeFromPositions(g.NavScoringNoClipRect.Min.y, g.NavScoringNoClipRect.Max.y, nav_off_min, nav_off_max))
                end
            end
            if is_nav_request and bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.IsTabbing) ~= 0 and g.NavTabbingDir == -1 then
                data.Ranges:push_back(ClipperRangeFromIndices(clipper.ItemsCount - 1, clipper.ItemsCount))
            end

            -- Add focused/active item
            local nav_rect_abs = ImGui.WindowRectRelToAbs(window, window.NavRectRel[0])
            if g.NavId ~= 0 and window.NavLastIds[0] == g.NavId then
                data.Ranges:push_back(ClipperRangeFromPositions(nav_rect_abs.Min.y, nav_rect_abs.Max.y, 0, 0))
            end

            local min_y = window.ClipRect.Min.y
            local max_y = window.ClipRect.Max.y

            -- Add box selection range
            local bs = g.BoxSelectState
            if bs and bs.IsActive and bs.Window == window then
                -- FIXME: Selectable() use of half-ItemSpacing isn't consistent in matter of layout, as ItemAdd(bb) stray above ItemSize()'s CursorPos.
                -- RangeSelect's BoxSelect relies on comparing overlap of previous and current rectangle and is sensitive to that.
                -- As a workaround we currently half ItemSpacing worth on each side.
                local pad_y = g.Style.ItemSpacing.y
                min_y = min_y - pad_y
                max_y = max_y + pad_y

                -- Box-select on 2D area requires different clipping.
                -- (best adding pad_y here than in BeginBoxSelect() as we are closer to current state)
                if bs.UnclipMode then
                    data.Ranges:push_back(ClipperRangeFromPositions(bs.UnclipRect.Min.y - pad_y, bs.UnclipRect.Max.y + pad_y, 0, 0))
                end
            end

            -- Add main visible range
            data.Ranges:push_back(ClipperRangeFromPositions(min_y, max_y, nav_off_min, nav_off_max))
        end

        -- Convert position ranges to item index ranges
        -- - Very important: when a starting position is after our maximum item, we set Min to (ItemsCount - 1). This allows us to handle most forms of wrapping.
        -- - Due to how Selectable extra padding they tend to be "unaligned" with exact unit in the item list,
        --   which with the flooring/ceiling tend to lead to 2 items instead of one being submitted.
        for _, range in data.Ranges:iter() do
            if range.PosToIndexConvert then
                local m1 = ImTrunc((range.Min - window.DC.CursorPos.y - data.LossynessOffset) / clipper.ItemsHeight)
                local m2 = ImTrunc(((range.Max - window.DC.CursorPos.y - data.LossynessOffset) / clipper.ItemsHeight) + 0.999999)
                range.Min = ImClamp(already_submitted + m1 + range.PosToIndexOffsetMin, already_submitted, clipper.ItemsCount - 1)
                range.Max = ImClamp(already_submitted + m2 + range.PosToIndexOffsetMax, range.Min + 1, clipper.ItemsCount)
                range.PosToIndexConvert = false
            end
        end
        ImGuiListClipper_SortAndFuseRanges(data.Ranges, data.StepNo)
    end

    -- Step 0+ (if item height is given in advance) or 1+: Display the next range in line.
    while data.StepNo < data.Ranges.Size do
        local r = data.Ranges.Data[data.StepNo + 1]
        clipper.DisplayStart = ImMax(r.Min, already_submitted)
        clipper.DisplayEnd = ImMin(r.Max, clipper.ItemsCount)
        data.StepNo = data.StepNo + 1
        if clipper.DisplayStart < clipper.DisplayEnd then
            if clipper.DisplayStart > already_submitted then
                clipper:SeekCursorForItem(clipper.DisplayStart)
            end
            return true
        end
    end

    -- After the last step: Let the clipper validate that we have reached the expected Y position (corresponding to element DisplayEnd),
    -- Advance the cursor to the end of the list and then returns 'false' to end the loop.
    if clipper.ItemsCount < INT_MAX then
        clipper:SeekCursorForItem(clipper.ItemsCount)
    end
    return false
end

function MT.ImGuiListClipper:Step()
    local ret = ImGuiListClipper_StepInternal(self)
    if ret and (self.DisplayStart >= self.DisplayEnd) then
        ret = false
    end
    if not ret then
        self:End()
    end
    return ret
end

-- Generic helper, equivalent to old ImGui.CalcListClipping() but stateless
-- Returns (out_visible_start, out_visible_end)
function ImGui.CalcClipRectVisibleItemsY(clip_rect, pos, items_height)
    local out_visible_start = ImMax(ImTrunc((clip_rect.Min.y - pos.y) / items_height), 0)
    local out_visible_end = ImMax(ImTrunc(ImCeil((clip_rect.Max.y - pos.y) / items_height)), out_visible_start)
    return out_visible_start, out_visible_end
end

-------------------------------------------------------------------------------
-- [SECTION] ERROR CHECKING, STATE RECOVERY
-------------------------------------------------------------------------------
-- - ErrorRecoveryStoreState()
-- - ErrorRecoveryTryToRecoverState()
-- - ErrorRecoveryTryToRecoverWindowState()
-- - ErrorLog()
-------------------------------------------------------------------------------

function ImGuiErrorRecoveryState()
    return { SizeOfWindowStack = 0, SizeOfIDStack = 0, SizeOfTreeStack = 0, SizeOfColorStack = 0, SizeOfStyleVarStack = 0,
             SizeOfFontStack = 0, SizeOfFocusScopeStack = 0, SizeOfGroupStack = 0, SizeOfItemFlagsStack = 0,
             SizeOfBeginPopupStack = 0, SizeOfDisabledStack = 0 }
end

-- Save current stack sizes. Called e.g. by NewFrame() and by Begin() but may be called for manual recovery.
function ImGui.ErrorRecoveryStoreState(state_out)
    local g = GImGui
    state_out.SizeOfWindowStack = g.CurrentWindowStack.Size
    state_out.SizeOfIDStack = g.CurrentWindow.IDStack.Size
    state_out.SizeOfTreeStack = g.CurrentWindow.DC.TreeDepth -- NOT g.TreeNodeStack.Size which is a partial stack!
    state_out.SizeOfColorStack = g.ColorStack.Size
    state_out.SizeOfStyleVarStack = g.StyleVarStack.Size
    state_out.SizeOfFontStack = g.FontStack.Size
    state_out.SizeOfFocusScopeStack = g.FocusScopeStack.Size
    state_out.SizeOfGroupStack = g.GroupStack.Size
    state_out.SizeOfItemFlagsStack = g.ItemFlagsStack.Size
    state_out.SizeOfBeginPopupStack = g.BeginPopupStack.Size
    state_out.SizeOfDisabledStack = g.DisabledStackSize
end

-- Chosen name "Try to recover" over e.g. "Restore" to suggest this is not a 100% guaranteed recovery.
-- Called by e.g. EndFrame() but may be called for manual recovery.
-- Attempt to recover full window stack.
function ImGui.ErrorRecoveryTryToRecoverState(state_in)
    local g = GImGui
    while g.CurrentWindowStack.Size > state_in.SizeOfWindowStack do
        -- Recap:
        -- - Begin()/BeginChild() return false to indicate the window is collapsed or fully clipped.
        -- - Always call a matching End() for each Begin() call, regardless of its return value!
        -- - Begin/End and BeginChild/EndChild logic is KNOWN TO BE INCONSISTENT WITH ALL OTHER BEGIN/END FUNCTIONS.
        -- - We will fix that in a future major update.
        local window = g.CurrentWindow
        if bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0 then
            if g.CurrentTable ~= nil and g.CurrentTable.InnerWindow == g.CurrentWindow then
                IM_ASSERT_USER_ERROR(false, "Missing EndTable()")
                ImGui.EndTable()
            else
                IM_ASSERT_USER_ERROR(false, "Missing EndChild()")
                ImGui.EndChild()
            end
        else
            IM_ASSERT_USER_ERROR(false, "Missing End()")
            ImGui.End()
        end
    end
    if g.CurrentWindowStack.Size == state_in.SizeOfWindowStack then
        ImGui.ErrorRecoveryTryToRecoverWindowState(state_in)
    end
end

-- Called by e.g. End() but may be called for manual recovery.
-- Attempt to recover from incorrect usage of BeginXXX/EndXXX/PushXXX/PopXXX calls.
function ImGui.ErrorRecoveryTryToRecoverWindowState(state_in)
    local g = GImGui

    while g.CurrentTable ~= nil and g.CurrentTable.InnerWindow == g.CurrentWindow do
        IM_ASSERT_USER_ERROR(false, "Missing EndTable()")
        ImGui.EndTable()
    end

    local window = g.CurrentWindow

    -- FIXME: Can't recover from inside BeginTabItem/EndTabItem yet.
    while g.CurrentTabBar ~= nil and g.CurrentTabBar.Window == window do
        IM_ASSERT_USER_ERROR(false, "Missing EndTabBar()")
        ImGui.EndTabBar()
    end
    while g.CurrentMultiSelect ~= nil and g.CurrentMultiSelect.Storage.Window == window and ImGui.EndMultiSelect do
        IM_ASSERT_USER_ERROR(false, "Missing EndMultiSelect()")
        ImGui.EndMultiSelect()
    end
    if window.DC.MenuBarAppending then
        IM_ASSERT_USER_ERROR(false, "Missing EndMenuBar()")
        ImGui.EndMenuBar()
    end
    while window.DC.TreeDepth > state_in.SizeOfTreeStack do
        IM_ASSERT_USER_ERROR(false, "Missing TreePop()")
        ImGui.TreePop()
    end
    while g.GroupStack.Size > state_in.SizeOfGroupStack do
        IM_ASSERT_USER_ERROR(false, "Missing EndGroup()")
        ImGui.EndGroup()
    end
    IM_ASSERT(g.GroupStack.Size == state_in.SizeOfGroupStack)
    while window.IDStack.Size > state_in.SizeOfIDStack do
        IM_ASSERT_USER_ERROR(false, "Missing PopID()")
        ImGui.PopID()
    end
    while g.DisabledStackSize > state_in.SizeOfDisabledStack do
        IM_ASSERT_USER_ERROR(false, "Missing EndDisabled()")
        if bit32.band(g.CurrentItemFlags, ImGuiItemFlags.Disabled) ~= 0 then
            ImGui.EndDisabled()
        else
            ImGui.EndDisabledOverrideReenable()
            g.CurrentWindowStack:back().DisabledOverrideReenable = false
        end
    end
    IM_ASSERT(g.DisabledStackSize == state_in.SizeOfDisabledStack)
    while g.ColorStack.Size > state_in.SizeOfColorStack do
        IM_ASSERT_USER_ERROR(false, "Missing PopStyleColor()")
        ImGui.PopStyleColor()
    end
    while g.ItemFlagsStack.Size > state_in.SizeOfItemFlagsStack do
        IM_ASSERT_USER_ERROR(false, "Missing PopItemFlag()")
        ImGui.PopItemFlag()
    end
    while g.StyleVarStack.Size > state_in.SizeOfStyleVarStack do
        IM_ASSERT_USER_ERROR(false, "Missing PopStyleVar()")
        ImGui.PopStyleVar()
    end
    while g.FontStack.Size > state_in.SizeOfFontStack do
        IM_ASSERT_USER_ERROR(false, "Missing PopFont()")
        ImGui.PopFont()
    end
    while g.FocusScopeStack.Size > state_in.SizeOfFocusScopeStack do
        IM_ASSERT_USER_ERROR(false, "Missing PopFocusScope()")
        ImGui.PopFocusScope()
    end
    -- IM_ASSERT(g.FocusScopeStack.Size == state_in.SizeOfFocusScopeStack)
end

-- Lines are stored in g.DebugLogBuf (one chunk per call)
function ImGui.DebugLog(fmt, ...)
    local g = GImGui
    g.DebugLogBuf = g.DebugLogBuf or ImGuiTextBuffer()
    local str = string.format("[%05d] ", g.FrameCount) .. ((select("#", ...) > 0) and string.format(fmt, ...) or fmt)
    g.DebugLogBuf:append(str)
    -- Line index (upstream: g.DebugLogIndex). Lines are complete strings without '\n'.
    local lines = g.DebugLogLines
    if lines == nil then lines = { "" }; g.DebugLogLines = lines end
    for part, nl in string.gmatch(str, "([^\n]*)(\n?)") do
        lines[#lines] = lines[#lines] .. part
        if nl ~= "" then lines[#lines + 1] = "" end
        if part == "" and nl == "" then break end
    end
    if bit32.band(g.DebugLogFlags, ImGuiDebugLogFlags.OutputToTTY) ~= 0 then
        print((string.gsub(str, "\n$", "")))
    end
end

--- @return bool should_assert
function ImGui.ErrorLog(msg)
    local g = GImGui
    if g == nil then return true end
    -- Output to debug log
    local window = g.CurrentWindow

    if g.IO.ConfigErrorRecoveryEnableDebugLog then
        if g.ErrorFirst then
            ImGui.DebugLog(string.format("[imgui-error] (current settings: Assert=%d, Log=%d, Tooltip=%d)\n",
                g.IO.ConfigErrorRecoveryEnableAssert and 1 or 0, g.IO.ConfigErrorRecoveryEnableDebugLog and 1 or 0, g.IO.ConfigErrorRecoveryEnableTooltip and 1 or 0))
        end
        ImGui.DebugLog(string.format("[imgui-error] In window '%s': %s\n", window and window.Name or "NULL", tostring(msg)))
    end
    g.ErrorFirst = false

    -- Output to tooltip
    if g.IO.ConfigErrorRecoveryEnableTooltip then
        if g.WithinFrameScope and ImGui.BeginErrorTooltip() then
            if g.ErrorCountCurrentFrame < 20 then
                ImGui.Text("In window '%s': %s", window and window.Name or "NULL", tostring(msg))
                if window and (not window.IsFallbackWindow or window.WasActive) then
                    ImGui.GetForegroundDrawList(window.Viewport):AddRect(window.Pos, window.Pos + window.Size, IM_COL32(255, 0, 0, 255))
                end
            end
            if g.ErrorCountCurrentFrame == 20 then
                ImGui.Text("(and more errors)")
            end
            -- EndFrame() will amend debug buttons to this window, after all errors have been submitted.
            ImGui.EndErrorTooltip()
        end
        g.ErrorCountCurrentFrame = g.ErrorCountCurrentFrame + 1
    end

    -- Output to callback
    if g.ErrorCallback ~= nil then
        g.ErrorCallback(g, g.ErrorCallbackUserData, msg)
    end

    -- Return whether we should assert
    return g.IO.ConfigErrorRecoveryEnableAssert
end

-- Display an error tooltip when same ID as HoveredId was submitted multiple times.
-- See code in ItemHoverable() for an explanation of why we associate this error to HoveredId + code drawing of rectangles over individual items instances.
function ImGui.ErrorCheckEndFrameFinalizeErrorTooltip()
    local g = GImGui
    if g.DebugDrawIdConflictsId ~= 0 and g.IO.KeyCtrl == false then
        g.DebugDrawIdConflictsCount = g.HoveredIdPreviousFrameItemCount
    end
    if g.DebugDrawIdConflictsId ~= 0 and not g.DebugItemPickerActive and ImGui.BeginErrorTooltip() then
        ImGui.Text("Programmer error: %d visible items with conflicting ID!", g.DebugDrawIdConflictsCount)
        ImGui.BulletText("Code should use PushID()/PopID() in loops, or append \"##xx\" to same-label identifiers!")
        ImGui.BulletText("Empty label e.g. Button(\"\") == same ID as parent widget/node. Use Button(\"##xx\") instead!")
        -- ImGui.BulletText("Code intending to use duplicate ID may use e.g. PushItemFlag(ImGuiItemFlags.AllowDuplicateId, true); ... PopItemFlag()") -- Not making this too visible for fear of it being abused.
        ImGui.BulletText("Set io.ConfigDebugHighlightIdConflicts=false to disable this warning in non-programmers builds.")
        ImGui.Separator()
        ImGui.Text("(Hold Ctrl to: ")
        ImGui.SameLine(0.0, 0.0)
        ImGui.TextLinkOpenURL("read FAQ \"About ID Stack System\"", "https://github.com/ocornut/imgui/blob/master/docs/FAQ.md#qa-usage")
        ImGui.SameLine(0.0, 0.0)
        ImGui.Text(")")
        ImGui.EndErrorTooltip()
    end

    if g.ErrorCountCurrentFrame > 0 and ImGui.BeginErrorTooltip() then -- Amend at end of frame
        ImGui.Separator()
        ImGui.Text("(Hold Ctrl to: ")
        ImGui.SameLine(0.0, 0.0)
        if ImGui.SmallButton("Enable Asserts") then
            g.IO.ConfigErrorRecoveryEnableAssert = true
        end
        -- ImGui.SameLine()
        -- if ImGui.SmallButton("Hide Error Tooltips") then
        --     g.IO.ConfigErrorRecoveryEnableTooltip = false -- Too dangerous
        -- end
        ImGui.SameLine(0, 0)
        ImGui.Text(")")
        ImGui.EndErrorTooltip()
    end
end

-- Pseudo-tooltip. Follow mouse until Ctrl is held. When Ctrl is held we lock position, allowing to click it.
function ImGui.BeginErrorTooltip()
    local g = GImGui
    local window = ImGui.FindWindowByName("##Tooltip_Error")
    local use_locked_pos = g.IO.KeyCtrl and window ~= nil and window.WasActive
    local c = g.Style.Colors[ImGuiCol.PopupBg]
    ImGui.PushStyleColor(ImGuiCol.PopupBg, ImVec4(ImLerp(c.x, 1.0, 0.15), ImLerp(c.y, 0.0, 0.15), ImLerp(c.z, 0.0, 0.15), ImLerp(c.w, 1.0, 0.15)))
    if use_locked_pos then
        ImGui.SetNextWindowPos(g.ErrorTooltipLockedPos)
    end
    local _, is_visible = ImGui.Begin("##Tooltip_Error", nil, bit32.bor(ImGuiWindowFlags.Tooltip, ImGuiWindowFlags.NoDecoration, ImGuiWindowFlags.NoMove, ImGuiWindowFlags.NoResize, ImGuiWindowFlags.NoSavedSettings, ImGuiWindowFlags.AlwaysAutoResize))
    ImGui.PopStyleColor()
    if is_visible and g.CurrentWindow.BeginCount == 1 then
        ImGui.SeparatorText("MESSAGE FROM DEAR IMGUI")
        ImGui.BringWindowToDisplayFront(g.CurrentWindow)
        ImGui.BringWindowToFocusFront(g.CurrentWindow)
        g.ErrorTooltipLockedPos = ImGui.GetWindowPos()
    elseif not is_visible then
        ImGui.End()
    end
    return is_visible
end

function ImGui.EndErrorTooltip()
    ImGui.End()
end


do --[[ [SECTION] METRICS/DEBUGGER WINDOW, DEBUG LOG, ID STACK TOOL, FONT DEBUG ]]

-------------------------------------------------------------------------------
-- [SECTION] Font atlas / font debugging
-------------------------------------------------------------------------------

-- byte buffers for InputText (same as the demo's DemoBuf/DemoBufStr; kept here so the library doesn't need the demo)
local function DemoBuf(str, size)
    local t = {}
    for i = 1, #str do t[i] = string.byte(str, i) end
    t[#str + 1] = 0
    if size then for i = #str + 2, size do t[i] = 0 end end
    return t
end
local function DemoBufStr(buf)
    local n = 0
    while buf[n + 1] ~= nil and buf[n + 1] ~= 0 do n = n + 1 end
    if n == 0 then return "" end
    return ImGui._ByteArrayToString(buf, 1, n + 1)
end

-- Avoid naming collision with imgui_demo's HelpMarker() for unity builds.
local function MetricsHelpMarker(desc)
    ImGui.TextDisabled("(?)")
    if ImGui.BeginItemTooltip() then
        ImGui.PushTextWrapPos(ImGui.GetFontSize() * 35.0)
        ImGui.TextUnformatted(desc)
        ImGui.PopTextWrapPos()
        ImGui.EndTooltip()
    end
end
ImGui.MetricsHelpMarker = MetricsHelpMarker

local function U8(c) return (c and c > 0) and utf8.char(c) or "" end

-- Demo helper function to select among loaded fonts.
-- Here we use the regular BeginCombo()/EndCombo() api which is the more flexible one.
function ImGui.ShowFontSelector(label)
    local io = ImGui.GetIO()
    local font_current = ImGui.GetFont()
    if ImGui.BeginCombo(label, font_current:GetDebugName()) then
        for i, font in io.Fonts.Fonts:iter() do
            ImGui.PushID(i)
            if ImGui.Selectable(font:GetDebugName(), font == font_current, ImGuiSelectableFlags.SelectOnNav) then io.FontDefault = font end
            if font == font_current then ImGui.SetItemDefaultFocus() end
            ImGui.PopID()
        end
        ImGui.EndCombo()
    end
    ImGui.SameLine()
    MetricsHelpMarker("- Load additional fonts with io.Fonts->AddFontXXX() functions.\n- On Roblox: register the .ttf bytes with ImGui_ImplRoblox.AddFile() first.\n- Read FAQ and docs/FONTS.md for more details.")
end

function ImGui.DebugNodeFontGlyph(font, glyph)
    ImGui.Text("Codepoint: U+%04X", glyph.Codepoint)
    ImGui.Separator()
    ImGui.Text("Visible: %d", glyph.Visible and 1 or 0)
    ImGui.Text("AdvanceX: %.1f", glyph.AdvanceX)
    ImGui.Text("Pos: (%.2f,%.2f)->(%.2f,%.2f)", glyph.X0, glyph.Y0, glyph.X1, glyph.Y1)
    ImGui.Text("UV: (%.3f,%.3f)->(%.3f,%.3f)", glyph.U0, glyph.V0, glyph.U1, glyph.V1)
    if glyph.PackId >= 0 then
        local r = { uv0 = ImVec2(), uv1 = ImVec2() }
        if font.OwnerAtlas:GetCustomRect(glyph.PackId, r) then ImGui.Text("PackId: 0x%X (%dx%d rect at %d,%d)", glyph.PackId, r.w, r.h, r.x, r.y) end
    end
    ImGui.Text("SourceIdx: %d", glyph.SourceIdx)
end

function ImGui.DebugNodeFontGlyphsForSrcMask(font, baked, src_mask)
    local draw_list = ImGui.GetWindowDrawList()
    local glyph_col = ImGui.GetColorU32(ImGuiCol.Text)
    local cell_size = baked.Size * 1
    local cell_spacing = ImGui.GetStyle().ItemSpacing.y
    -- [port] only scans loaded codepoints (IndexLookup range) instead of the whole 0..0xFFFF range
    local max_c = baked.IndexLookup.Size - 1
    local base = 0
    while base <= max_c do
        local count = 0
        -- [Luau] inline IsGlyphLoaded() + FindGlyphNoFallback() (a loaded glyph never needs loading): 0xFFFF = IM_FONTGLYPH_INDEX_UNUSED, 0xFFFE = IM_FONTGLYPH_INDEX_NOT_FOUND
        local lookup, lookup_n, glyphs = baked.IndexLookup.Data, baked.IndexLookup.Size, baked.Glyphs.Data
        for n = 0, 255 do
            local c = base + n
            if c < lookup_n then
                local i = lookup[c + 1]
                if i ~= 0xFFFF and i ~= 0xFFFE then
                    local glyph = glyphs[i]
                    if glyph and bit32.band(src_mask, bit32.lshift(1, glyph.SourceIdx)) ~= 0 then count = count + 1 end
                end
            end
        end
        if count > 0 and ImGui.TreeNode(base, "U+%04X..U+%04X (%d %s)", base, base + 255, count, (count > 1) and "glyphs" or "glyph") then
            -- Draw a 16x16 grid of glyphs
            local base_pos = ImGui.GetCursorScreenPos()
            local cell_p1, cell_p2 = ImVec2(), ImVec2()
            for n = 0, 255 do
                local c = base + n
                -- We use ImFont:RenderChar as a shortcut because we don't have UTF-8 conversion functions
                -- available here and thus cannot easily generate a zero-terminated UTF-8 encoded string.
                -- [Luau] reused per cell: AddRect()/RenderChar()/IsMouseHoveringRect() only read them
                cell_p1.x = base_pos.x + (n % 16) * (cell_size + cell_spacing); cell_p1.y = base_pos.y + math.floor(n / 16) * (cell_size + cell_spacing)
                cell_p2.x = cell_p1.x + cell_size; cell_p2.y = cell_p1.y + cell_size
                local glyph = nil -- [Luau] inline IsGlyphLoaded() + FindGlyphNoFallback(), see above
                if c < baked.IndexLookup.Size then
                    local i = baked.IndexLookup.Data[c + 1]
                    if i ~= 0xFFFF and i ~= 0xFFFE then glyph = baked.Glyphs.Data[i] end
                end
                draw_list:AddRect(cell_p1, cell_p2, glyph and IM_COL32(255, 255, 255, 100) or IM_COL32(255, 255, 255, 50))
                if glyph and bit32.band(src_mask, bit32.lshift(1, glyph.SourceIdx)) ~= 0 then
                    font:RenderChar(draw_list, cell_size, cell_p1, glyph_col, c)
                    if ImGui.IsMouseHoveringRect(cell_p1, cell_p2) and ImGui.BeginTooltip() then
                        ImGui.DebugNodeFontGlyph(font, glyph)
                        ImGui.EndTooltip()
                    end
                end
            end
            ImGui.Dummy(ImVec2((cell_size + cell_spacing) * 16, (cell_size + cell_spacing) * 16))
            ImGui.TreePop()
        end
        base = base + 256
    end
end

-- [DEBUG] Display details for a single font, called by ShowStyleEditor().
function ImGui.DebugNodeFont(font)
    local g = ImGui.GetCurrentContext()
    local cfg = g.DebugMetricsConfig
    local atlas = font.OwnerAtlas
    local opened = ImGui.TreeNode(tostring(font), "Font: \"%s\": %d sources(s)", font:GetDebugName(), font.Sources.Size)

    -- Display preview text
    if not opened then ImGui.Indent() end
    ImGui.Indent()
    if cfg.ShowFontPreview then
        ImGui.PushFont(font, 0.0)
        ImGui.Text("The quick brown fox jumps over the lazy dog")
        ImGui.PopFont()
    end
    if not opened then
        ImGui.Unindent()
        ImGui.Unindent()
        return
    end
    if ImGui.SmallButton("Set as default") then ImGui.GetIO().FontDefault = font end
    ImGui.SameLine()
    ImGui.BeginDisabled(atlas.Fonts.Size <= 1 or atlas.Locked == true or atlas.RemoveFont == nil)
    if ImGui.SmallButton("Remove") and atlas.RemoveFont then atlas:RemoveFont(font) end
    ImGui.EndDisabled()
    ImGui.SameLine()
    if ImGui.SmallButton("Clear bakes") then ImFontAtlasFontDiscardBakes(atlas, font, 0) end
    ImGui.SameLine()
    if ImGui.SmallButton("Clear unused") then ImFontAtlasFontDiscardBakes(atlas, font, 2) end

    -- Display details
    ImGui.Text("Fallback character: '%s' (U+%04X)", U8(font.FallbackChar), font.FallbackChar or 0)
    ImGui.Text("Ellipsis character: '%s' (U+%04X)", U8(font.EllipsisChar), font.EllipsisChar or 0)
    for src_n, src in font.Sources:iter() do
        if ImGui.TreeNode(tostring(src), "Input %d: '%s' [%d], Oversample: %d,%d, PixelSnapH: %d, Offset: (%.1f,%.1f)",
            src_n - 1, src.Name or "", src.FontNo or 0, src.OversampleH or 0, src.OversampleV or 0, src.PixelSnapH and 1 or 0, src.GlyphOffset.x, src.GlyphOffset.y) then
            local loader = src.FontLoader or atlas.FontLoader
            ImGui.Text("Loader: '%s'", (loader and loader.Name) or "N/A")

            -- if ImGui.DragFloat("ExtraSizeScale", src.ExtraSizeScale, 0.01, 0.10, 2.0) then
            --     ImFontAtlasFontRebuildOutput(atlas, font)
            -- end
            ImGui.TreePop()
        end
    end

    -- Display all glyphs of the fonts in separate pages of 256 characters
    local builder = atlas.Builder
    if builder then
        for _, baked in builder.BakedPool:iter() do
            if baked.OwnerFont == font then
                ImGui.PushID(baked.BakedId)
                if ImGui.TreeNode("Glyphs", "Baked at { %.2fpx, d.%.2f }: %d glyphs%s", baked.Size, baked.RasterizerDensity, baked.Glyphs.Size,
                    (baked.LastUsedFrame < (builder.FrameCount or 0) - 1) and " *Unused*" or "") then
                    if ImGui.SmallButton("Load all") then
                        for c = 0, 0x7F do baked:FindGlyph(c) end -- [port] ASCII only: loading the whole BMP in Luau stalls for seconds
                    end
                    local surface_sqrt = math.floor(math.sqrt(baked.MetricsTotalSurface))
                    ImGui.Text("Ascent: %f, Descent: %f, Ascent-Descent: %f", baked.Ascent, baked.Descent, baked.Ascent - baked.Descent)
                    ImGui.Text("Texture Area: about %d px ~%dx%d px", baked.MetricsTotalSurface, surface_sqrt, surface_sqrt)
                    for src_n, src in font.Sources:iter() do
                        ImGui.BulletText("Input %d: '%s', Oversample: (%d,%d), PixelSnapH: %d, Offset: (%.1f,%.1f)",
                            src_n - 1, src.Name or "", src.OversampleH or 0, src.OversampleV or 0, src.PixelSnapH and 1 or 0, src.GlyphOffset.x, src.GlyphOffset.y)
                    end
                    ImGui.DebugNodeFontGlyphsForSrcMask(font, baked, bit32.bnot(0))
                    ImGui.TreePop()
                end
                ImGui.PopID()
            end
        end
    end
    ImGui.TreePop()
    ImGui.Unindent()
end

local StatusNames = { [0] = "OK", "Destroyed", "WantCreate", "WantUpdates", "WantDestroy" }
local FormatNames = { [0] = "RGBA32", "Alpha8" }

function ImGui.DebugNodeTexture(tex, int_id, highlight_rect)
    local g = ImGui.GetCurrentContext()
    ImGui.PushID(int_id)
    if ImGui.TreeNode("", "Texture #%03d (%dx%d pixels)", tex.UniqueID or 0, tex.Width, tex.Height) then
        local cfg = g.DebugMetricsConfig
        _, cfg.ShowTextureUsedRect = ImGui.Checkbox("Show used rect", cfg.ShowTextureUsedRect)
        ImGui.PushStyleVar(ImGuiStyleVar.ImageBorderSize, math.max(1.0, g.Style.ImageBorderSize))
        local p = ImGui.GetCursorScreenPos()
        if tex.Status == ImTextureStatus.WantDestroy or tex.Status == ImTextureStatus.Destroyed then
            ImGui.Dummy(ImVec2(tex.Width, tex.Height))
        else
            local ref = ImTextureRef(); ref._TexData = tex
            ImGui.ImageWithBg(ref, ImVec2(tex.Width, tex.Height), ImVec2(0.0, 0.0), ImVec2(1.0, 1.0), ImVec4(0.0, 0.0, 0.0, 1.0))
        end
        if cfg.ShowTextureUsedRect and tex.UsedRect then
            local u = tex.UsedRect
            ImGui.GetWindowDrawList():AddRect(ImVec2(p.x + u.x, p.y + u.y), ImVec2(p.x + u.x + u.w, p.y + u.y + u.h), IM_COL32(255, 0, 255, 255))
        end
        if highlight_rect ~= nil then
            local r_outer = ImRect(p.x, p.y, p.x + tex.Width, p.y + tex.Height)
            local r_inner = ImRect(p.x + highlight_rect.x, p.y + highlight_rect.y, p.x + highlight_rect.x + highlight_rect.w, p.y + highlight_rect.y + highlight_rect.h)
            ImGui.RenderRectFilledWithHole(ImGui.GetWindowDrawList(), r_outer, r_inner, IM_COL32(0, 0, 0, 100), 0.0)
            ImGui.GetWindowDrawList():AddRect(r_inner.Min - ImVec2(1, 1), r_inner.Max + ImVec2(1, 1), IM_COL32(255, 255, 0, 255))
        end
        ImGui.PopStyleVar()
        ImGui.Text("Status = %s (%d), Format = %s (%d), UseColors = %d", StatusNames[tex.Status] or "?", tex.Status, FormatNames[tex.Format] or "?", tex.Format, tex.UseColors and 1 or 0)
        ImGui.Text("TexID = %s", tostring(tex.TexID))
        ImGui.TreePop()
    end
    ImGui.PopID()
end

-- [DEBUG] List fonts in a font atlas and display its texture
function ImGui.ShowFontAtlas(atlas)
    local g = ImGui.GetCurrentContext()
    local io = g.IO
    local style = g.Style
    ImGui.BeginDisabled()
    ImGui.CheckboxFlags("io.BackendFlags: RendererHasTextures", io.BackendFlags, ImGuiBackendFlags.RendererHasTextures)
    ImGui.EndDisabled()
    ImGui.ShowFontSelector("Font")
    local changed
    style.FontSizeBase, changed = ImGui.DragFloat("FontSizeBase", style.FontSizeBase, 0.20, 5.0, 100.0, "%.0f")
    if changed then style._NextFrameFontSizeBase = style.FontSizeBase end -- FIXME: Temporary hack until we finish remaining work.
    ImGui.SameLine(0.0, 0.0); ImGui.Text(" (out %.2f)", ImGui.GetFontSize())
    ImGui.SameLine(); MetricsHelpMarker("- This is scaling font only. General scaling will come later.")
    style.FontScaleMain = ImGui.DragFloat("FontScaleMain", style.FontScaleMain, 0.02, 0.5, 4.0)
    style.FontScaleDpi = ImGui.DragFloat("FontScaleDpi", style.FontScaleDpi, 0.02, 0.5, 4.0)
    ImGui.BulletText("Load a nice font for better results!")
    ImGui.BulletText("Please submit feedback:")
    ImGui.SameLine(); ImGui.TextLinkOpenURL("#8465", "https://github.com/ocornut/imgui/issues/8465")
    ImGui.BulletText("Read FAQ for more details:")
    ImGui.SameLine(); ImGui.TextLinkOpenURL("dearimgui.com/faq", "https://www.dearimgui.com/faq/")

    ImGui.SeparatorText("Font List")
    local cfg = g.DebugMetricsConfig
    _, cfg.ShowFontPreview = ImGui.Checkbox("Show font preview", cfg.ShowFontPreview == true)
    -- Font loaders
    if ImGui.TreeNode("Loader", "Loader: '%s'", atlas.FontLoaderName or "NULL") then
        ImGui.BeginDisabled()
        ImGui.RadioButtonEx("stb_truetype", true)
        ImGui.SameLine()
        ImGui.RadioButtonEx("FreeType", false)
        ImGui.SetItemTooltip("Not available on Roblox.")
        ImGui.EndDisabled()
        ImGui.TreePop()
    end
    -- Font list
    for i, font in atlas.Fonts:iter() do
        ImGui.PushID(i)
        ImGui.DebugNodeFont(font)
        ImGui.PopID()
    end

    ImGui.SeparatorText("Font Atlas")
    if ImGui.Button("Compact") then atlas:CompactCache() end
    ImGui.SameLine()
    if ImGui.Button("Grow") then ImFontAtlasTextureGrow(atlas) end
    ImGui.SameLine()
    if ImGui.Button("Clear All") then ImFontAtlasBuildClear(atlas) end
    ImGui.SetItemTooltip("Destroy cache and custom rectangles.")
    for tex_n, tex in atlas.TexList:iter() do
        if tex_n > 1 then ImGui.SameLine() end
        ImGui.Text("Tex: %dx%d", tex.Width, tex.Height)
    end
    local b = atlas.Builder
    if b then
        local packed_sqrt = math.floor(math.sqrt(b.RectsPackedSurface or 0))
        local discarded_sqrt = math.floor(math.sqrt(b.RectsDiscardedSurface or 0))
        ImGui.Text("Packed rects: %d, area: about %d px ~%dx%d px", b.RectsPackedCount or 0, b.RectsPackedSurface or 0, packed_sqrt, packed_sqrt)
        ImGui.Text("incl. Discarded rects: %d, area: about %d px ~%dx%d px", b.RectsDiscardedCount or 0, b.RectsDiscardedSurface or 0, discarded_sqrt, discarded_sqrt)
    end
    -- Texture list
    -- (ensure the last texture always use the same ID, so we can keep it open neatly)
    for tex_n, tex in atlas.TexList:iter() do
        if tex_n == atlas.TexList.Size then ImGui.SetNextItemOpen(true, ImGuiCond.Once) end
        ImGui.DebugNodeTexture(tex, atlas.TexList.Size - tex_n, nil)
    end
end

-------------------------------------------------------------------------------
-- [SECTION] DEBUG LOG WINDOW
-------------------------------------------------------------------------------

-- FIXME-LAYOUT: To be done automatically via layout mode once we rework ItemSize/ItemAdd into ItemLayout.
local function SameLineOrWrap(size)
    local g = ImGui.GetCurrentContext()
    local window = g.CurrentWindow
    local pos = ImVec2(window.DC.CursorPosPrevLine.x + g.Style.ItemSpacing.x, window.DC.CursorPosPrevLine.y)
    if window.WorkRect:Contains(ImRect(pos, pos + size)) then ImGui.SameLine() end
end

local function ShowDebugLogFlag(name, flags)
    local g = ImGui.GetCurrentContext()
    local size = ImVec2(ImGui.GetFrameHeight() + g.Style.ItemInnerSpacing.x + ImGui.CalcTextSize(name).x, ImGui.GetFrameHeight())
    SameLineOrWrap(size) -- FIXME-LAYOUT: To be done automatically once we rework ItemSize/ItemAdd into ItemLayout.
    local pressed
    pressed, g.DebugLogFlags = ImGui.CheckboxFlags(name, g.DebugLogFlags, flags)
    if pressed and g.IO.KeyShift and bit32.band(g.DebugLogFlags, flags) ~= 0 then
        g.DebugLogAutoDisableFrames = 2
        g.DebugLogAutoDisableFlags = bit32.bor(g.DebugLogAutoDisableFlags or 0, flags)
    end
    ImGui.SetItemTooltip("Hold Shift when clicking to enable for 2 frames only (useful for spammy log entries)")
end

function ImGui.ShowDebugLogWindow(p_open)
    local g = ImGui.GetCurrentContext()
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasSize) == 0 then
        ImGui.SetNextWindowSize(ImVec2(0.0, ImGui.GetFontSize() * 12.0), ImGuiCond.FirstUseEver)
    end
    local visible
    p_open, visible = ImGui.Begin("Dear ImGui Debug Log", p_open)
    if not visible or ImGui.GetCurrentWindow().BeginCount > 1 then
        ImGui.End()
        return p_open
    end
    local L = ImGuiDebugLogFlags
    local all_enable_flags = bit32.band(L.EventMask_, bit32.bnot(L.EventInputRouting))
    _, g.DebugLogFlags = ImGui.CheckboxFlags("All", g.DebugLogFlags, all_enable_flags)
    ImGui.SetItemTooltip("(except InputRouting which is spammy)")
    for _, e in ipairs({ { "Errors", L.EventError }, { "ActiveId", L.EventActiveId }, { "Clipper", L.EventClipper }, { "Docking", L.EventDocking },
        { "Focus", L.EventFocus }, { "IO", L.EventIO }, { "Font", L.EventFont }, { "Nav", L.EventNav }, { "Popup", L.EventPopup },
        { "Selection", L.EventSelection }, { "Table", L.EventTable }, { "Viewport", L.EventViewport }, { "InputRouting", L.EventInputRouting } }) do
        ShowDebugLogFlag(e[1], e[2])
    end
    if ImGui.SmallButton("Clear") then
        if g.DebugLogBuf then g.DebugLogBuf:clear() end
        g.DebugLogLines = { "" }
    end
    ImGui.SameLine()
    if ImGui.SmallButton("Copy") then ImGui.SetClipboardText(g.DebugLogBuf and g.DebugLogBuf:c_str() or "") end
    ImGui.SameLine()
    if ImGui.SmallButton("Configure Outputs..") then ImGui.OpenPopup("Outputs") end
    if ImGui.BeginPopup("Outputs") then
        _, g.DebugLogFlags = ImGui.CheckboxFlags("OutputToTTY", g.DebugLogFlags, L.OutputToTTY)
        ImGui.BeginDisabled()
        _, g.DebugLogFlags = ImGui.CheckboxFlags("OutputToDebugger", g.DebugLogFlags, L.OutputToDebugger)
        _, g.DebugLogFlags = ImGui.CheckboxFlags("OutputToTestEngine", g.DebugLogFlags, L.OutputToTestEngine)
        ImGui.EndDisabled()
        ImGui.EndPopup()
    end

    ImGui.BeginChild("##log", ImVec2(0.0, 0.0), ImGuiChildFlags.Borders, bit32.bor(ImGuiWindowFlags.AlwaysVerticalScrollbar, ImGuiWindowFlags.AlwaysHorizontalScrollbar))
    local backup_log_flags = g.DebugLogFlags
    g.DebugLogFlags = bit32.band(g.DebugLogFlags, bit32.bnot(L.EventClipper))
    local lines = g.DebugLogLines or { "" }
    local count = #lines
    if lines[count] == "" then count = count - 1 end -- trailing partial line
    local clipper = ImGuiListClipper()
    clipper:Begin(count)
    while clipper:Step() do
        for line_no = clipper.DisplayStart, clipper.DisplayEnd - 1 do ImGui.TextUnformatted(lines[line_no + 1]) end
    end
    g.DebugLogFlags = backup_log_flags
    if ImGui.GetScrollY() >= ImGui.GetScrollMaxY() then ImGui.SetScrollHereY(1.0) end
    ImGui.EndChild()
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] OTHER DEBUG TOOLS (ITEM PICKER, ID STACK TOOL)
-------------------------------------------------------------------------------

local function PathQuery(g)
    local q = g.DebugItemPathQuery
    if q == nil then
        q = { MainID = 0, Active = false, Complete = false, Step = -1, Results = {} }
        g.DebugItemPathQuery = q
        g.DebugIDStackTool = { LastActiveFrame = -1, OptHexEncodeNonAsciiChars = true, OptCopyToClipboardOnCtrlC = false, CopyToClipboardLastTime = -FLT_MAX }
    end
    return q
end

-- Update queries. The steps are: -1: query Stack, >= 0: query each stack item
-- We can only perform 1 ID Info query every frame. This is designed so the GetID() tests are cheap and constant-time
local function DebugItemPathQuery_UpdateAndGetHookId(query, id)
    -- Update query. Clear hook when no active query
    if query.MainID ~= id then
        query.MainID = id
        query.Step = -1
        query.Complete = false
        query.Results = {}
    end
    query.Active = false
    if id == 0 then return 0 end
    local res = query.Results
    -- Advance to next stack level when we got our result, or after 2 frames (in case we never get a result)
    if query.Step >= 0 and query.Step < #res then
        if res[query.Step + 1].QuerySuccess or res[query.Step + 1].QueryFrameCount > 2 then query.Step = query.Step + 1 end
    end
    -- Update status and hook
    query.Complete = (query.Step == #res)
    if query.Step == -1 then
        query.Active = true
        return id
    elseif query.Step >= 0 and query.Step < #res then
        res[query.Step + 1].QueryFrameCount = res[query.Step + 1].QueryFrameCount + 1
        query.Active = true
        return res[query.Step + 1].ID
    end
    return 0
end

-- [DEBUG] ID Stack Tool: update query. Called by NewFrame()
function ImGui.UpdateDebugToolItemPathQuery()
    local g = ImGui.GetCurrentContext()
    local q = PathQuery(g)
    local id = 0
    if g.DebugIDStackTool.LastActiveFrame + 1 == g.FrameCount then
        id = (g.HoveredIdPreviousFrame ~= 0 and g.HoveredIdPreviousFrame) or g.ActiveId
    end
    g.DebugHookIdInfoId = DebugItemPathQuery_UpdateAndGetHookId(q, id)
end

-- [DEBUG] ID Stack tool: hooks called by GetID() family functions
-- `data_id` is the string/number that was hashed.
function ImGui.DebugHookIdInfo(id, data_type, data_id)
    local g = ImGui.GetCurrentContext()
    local query = PathQuery(g)
    if not query.Active then return end
    local window = g.CurrentWindow

    -- Step -1: stack query
    -- This assumes that the ID was computed with the current ID stack, which tends to be the case for our widget.
    if query.Step == -1 then
        query.Step = 0
        query.Results = {}
        for n = 0, window.IDStack.Size do
            query.Results[n + 1] = { ID = (n < window.IDStack.Size) and window.IDStack.Data[n + 1] or id, QueryFrameCount = 0, QuerySuccess = false, DataType = -1, Desc = nil }
        end
        return
    end
    -- Step 0+: query for individual level
    if query.Step ~= window.IDStack.Size then return end
    local info = query.Results[query.Step + 1]
    if info == nil or info.ID ~= id then return end
    if info.Desc == nil then
        if data_type == ImGuiDataType.S32 then info.Desc = string.format("%d", data_id)
        elseif data_type == ImGuiDataType.String then info.Desc = tostring(data_id)
        else info.Desc = string.format("0x%08X [override]", id) end -- PushOverrideID() is often used to avoid hashing twice, which would lead to 2 calls to DebugHookIdInfo(). We prioritize the first one.
    end
    info.QuerySuccess = true
    if info.DataType == -1 then info.DataType = data_type end
end

local function SkipUncontributingPrefix(label)
    local p = string.find(label, "###", 1, true)
    if p then return string.sub(label, p) end
    return label
end

local function FormatLevelInfo(g, query, n, format_for_ui)
    local info = query.Results[n + 1]
    local window = (info.Desc == nil and n == 0) and ImGui.FindWindowByID(info.ID) or nil
    if window then return string.format(format_for_ui and "\"%s\" [window]" or "%s", SkipUncontributingPrefix(window.Name)) end -- Source: window name (because the root ID don't call GetID() and so doesn't get hooked)
    if info.QuerySuccess then return string.format((format_for_ui and info.DataType == ImGuiDataType.String) and "\"%s\"" or "%s", SkipUncontributingPrefix(info.Desc)) end -- Source: GetID() hooks (prioritize over ItemInfo() because we frequently use patterns like: PushID(str), Button("") where they both have same id)
    if query.Step < #query.Results then return "" end -- Only start using fallback below when all queries are done, so during queries we don't flickering ??? markers.
    return "???"
end

local function GetResultAsPath(g, query, hex_encode_non_ascii_chars)
    local out = {}
    for n = 0, #query.Results - 1 do
        local desc = FormatLevelInfo(g, query, n, false)
        out[#out + 1] = (n == 0) and "//" or "/"
        desc = string.gsub(desc, "/", "\\/")
        if hex_encode_non_ascii_chars then
            desc = string.gsub(desc, "[\128-\255]", function(c) return string.format("\\x%02x", string.byte(c)) end)
        end
        out[#out + 1] = desc
    end
    return table.concat(out)
end

-- ID Stack Tool: Display UI
function ImGui.ShowIDStackToolWindow(p_open)
    local g = ImGui.GetCurrentContext()
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasSize) == 0 then
        ImGui.SetNextWindowSize(ImVec2(0.0, ImGui.GetFontSize() * 8.0), ImGuiCond.FirstUseEver)
    end
    local visible
    p_open, visible = ImGui.Begin("Dear ImGui ID Stack Tool", p_open)
    if not visible or ImGui.GetCurrentWindow().BeginCount > 1 then
        ImGui.End()
        return p_open
    end
    local query = PathQuery(g)
    local tool = g.DebugIDStackTool
    tool.LastActiveFrame = g.FrameCount
    local result_path = GetResultAsPath(g, query, tool.OptHexEncodeNonAsciiChars)
    ImGui.Text("0x%08X", query.MainID)
    ImGui.SameLine()
    MetricsHelpMarker("Hover an item with the mouse to display elements of the ID Stack leading to the item's final ID.\nEach level of the stack correspond to a PushID() call.\nAll levels of the stack are hashed together to make the final ID of a widget (ID displayed at the bottom level of the stack).\nRead FAQ entry about the ID stack for details.")

    -- Ctrl+C to copy path
    local time_since_copy = g.Time - tool.CopyToClipboardLastTime
    ImGui.PushStyleVarY(ImGuiStyleVar.FramePadding, 0.0)
    _, tool.OptHexEncodeNonAsciiChars = ImGui.Checkbox("Hex-encode non-ASCII", tool.OptHexEncodeNonAsciiChars)
    ImGui.SameLine()
    _, tool.OptCopyToClipboardOnCtrlC = ImGui.Checkbox("Ctrl+C: copy path", tool.OptCopyToClipboardOnCtrlC)
    ImGui.PopStyleVar()
    ImGui.SameLine()
    ImGui.TextColored((time_since_copy >= 0.0 and time_since_copy < 0.75 and math.fmod(time_since_copy, 0.25) < 0.25 * 0.5) and ImVec4(1.0, 1.0, 0.3, 1.0) or ImVec4(), "*COPIED*")
    if tool.OptCopyToClipboardOnCtrlC and ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.C), bit32.bor(ImGuiInputFlags.RouteGlobal, ImGuiInputFlags.RouteOverFocused)) then
        tool.CopyToClipboardLastTime = g.Time
        ImGui.SetClipboardText(result_path)
    end
    ImGui.Text("- Path \"%s\"", query.Complete and result_path or "")
    ImGui.Separator()

    -- Display decorated stack
    if #query.Results > 0 and ImGui.BeginTable("##table", 3, ImGuiTableFlags.Borders) then
        local id_width = ImGui.CalcTextSize("0xDDDDDDDD").x
        ImGui.TableSetupColumn("Seed", ImGuiTableColumnFlags.WidthFixed, id_width)
        ImGui.TableSetupColumn("PushID", ImGuiTableColumnFlags.WidthStretch)
        ImGui.TableSetupColumn("Result", ImGuiTableColumnFlags.WidthFixed, id_width)
        ImGui.TableHeadersRow()
        for n = 0, #query.Results - 1 do
            local info = query.Results[n + 1]
            ImGui.TableNextColumn()
            ImGui.Text("0x%08X", (n > 0) and query.Results[n].ID or 0)
            ImGui.TableNextColumn()
            ImGui.TextUnformatted(FormatLevelInfo(g, query, n, true))
            ImGui.TableNextColumn()
            ImGui.Text("0x%08X", info.ID)
            if n == #query.Results - 1 then ImGui.TableSetBgColor(ImGuiTableBgTarget.CellBg, ImGui.GetColorU32(ImGuiCol.Header)) end
        end
        ImGui.EndTable()
    end
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] METRICS/DEBUGGER WINDOW
-------------------------------------------------------------------------------
-- - DebugTextEncoding()
-- - ShowMetricsWindow()
-- - DebugNodeColumns() [Internal]
-- - DebugNodeDockNode() [Internal]
-- - DebugNodeDrawList() [Internal]
-- - DebugNodeStorage() [Internal]
-- - DebugNodeTabBar() [Internal]
-- - DebugNodeTable() [Internal]
-- - DebugNodeTableSettings() [Internal]
-- - DebugNodeViewport() [Internal]
-- - DebugNodeWindow() [Internal]
-- - DebugNodeWindowSettings() [Internal]
-- - DebugNodeWindowsList() [Internal]
-- - DebugNodeWindowsListByBeginStackParent() [Internal]
-------------------------------------------------------------------------------

local function B(v) return v and 1 or 0 end
local function FG(window) return ImGui.GetForegroundDrawList(window and window.Viewport or ImGui.GetMainViewport()) end
local function YellowRect(window, min, max) FG(window):AddRect(min, max, IM_COL32(255, 255, 0, 255)) end

-- [DEBUG] Display contents of Columns
function ImGui.DebugNodeColumns(columns)
    if not ImGui.TreeNode(columns.ID, "Columns Id: 0x%08X, Count: %d, Flags: 0x%04X", columns.ID, columns.Count, columns.Flags) then return end
    ImGui.BulletText("Width: %.1f (MinX: %.1f, MaxX: %.1f)", columns.OffMaxX - columns.OffMinX, columns.OffMinX, columns.OffMaxX)
    for i, column in columns.Columns:iter() do
        ImGui.BulletText("Column %02d: OffsetNorm %.3f (= %.1f px)", i - 1, column.OffsetNorm, ImGui.GetColumnOffsetFromNorm(columns, column.OffsetNorm))
    end
    ImGui.TreePop()
end

-- [DEBUG] Display contents of ImGuiStorage
function ImGui.DebugNodeStorage(storage, label)
    local n = 0
    for _ in pairs(storage) do n = n + 1 end
    if not ImGui.TreeNode(label, "%s: %d entries", label, n) then return end
    for k, v in pairs(storage) do
        ImGui.BulletText("Key 0x%08X Value { %s }", tonumber(k) or 0, tostring(v))
    end
    ImGui.TreePop()
end

-- [DEBUG] Display contents of ImDrawList
-- Note that both 'window' and 'viewport' may be nil here. Viewport is generally nil of destroyed popups which previously owned a viewport.
function ImGui.DebugNodeDrawList(window, viewport, draw_list, label)
    local g = ImGui.GetCurrentContext()
    local cfg = g.DebugMetricsConfig
    local cmd_count = draw_list.CmdBuffer.Size
    if cmd_count > 0 and draw_list.CmdBuffer.Data[cmd_count].ElemCount == 0 and draw_list.CmdBuffer.Data[cmd_count].UserCallback == nil then
        cmd_count = cmd_count - 1
    end
    local node_open = ImGui.TreeNode(tostring(draw_list), "%s: '%s' %d vtx, %d indices, %d cmds", label, draw_list._OwnerName or "", draw_list.VtxBuffer.Size, draw_list.IdxBuffer.Size, cmd_count)
    if draw_list == ImGui.GetWindowDrawList() then
        ImGui.SameLine()
        ImGui.TextColored(ImVec4(1.0, 0.4, 0.4, 1.0), "CURRENTLY APPENDING") -- Can't display stats for active draw list! (we don't have the data double-buffered)
        if node_open then ImGui.TreePop() end
        return
    end
    local fg_draw_list = viewport and ImGui.GetForegroundDrawList(viewport) or nil -- Render additional visuals into the top-most draw list
    if window and ImGui.IsItemHovered() and fg_draw_list then
        fg_draw_list:AddRect(window.Pos, window.Pos + window.Size, IM_COL32(255, 255, 0, 255))
    end
    if not node_open then return end
    if window and not window.WasActive then ImGui.TextDisabled("Warning: owning Window is inactive. This DrawList is not being rendered!") end

    local vtx, idx = draw_list.VtxBuffer.Buf, draw_list.IdxBuffer.Data
    for cmd_n = 1, cmd_count do
        local pcmd = draw_list.CmdBuffer.Data[cmd_n]
        if pcmd.UserCallback then
            ImGui.BulletText("Callback %s", tostring(pcmd.UserCallback))
        else
            local cr = pcmd.ClipRect
            local open = ImGui.TreeNode(cmd_n, "DrawCmd:%5d tris, Tex %s, ClipRect (%4.0f,%4.0f)-(%4.0f,%4.0f)", math.floor(pcmd.ElemCount / 3), tostring(pcmd.TexRef and (pcmd.TexRef._TexID or pcmd.TexRef._TexData)), cr.x, cr.y, cr.z, cr.w)
            local function ShowMesh(show_mesh, show_aabb)
                if not fg_draw_list then return end
                local clip_rect = ImRect(cr.x, cr.y, cr.z, cr.w)
                local vtxs_rect = ImRect(FLT_MAX, FLT_MAX, -FLT_MAX, -FLT_MAX)
                local base = pcmd.IdxOffset
                for i = base, base + pcmd.ElemCount - 1, 3 do
                    local tri = {}
                    for n = 0, 2 do
                        local vi = idx[i + n + 1] + pcmd.VtxOffset
                        if vi > draw_list.VtxBuffer.Size then return end
                        tri[n + 1] = ImVec2(ImDrawVtx_Pos(vtx, vi))
                        vtxs_rect:Add(tri[n + 1])
                    end
                    if show_mesh then fg_draw_list:AddPolyline(tri, 3, IM_COL32(255, 255, 0, 255), 1.0, ImDrawFlags.Closed) end -- In yellow: mesh triangles
                end
                if show_aabb then
                    fg_draw_list:AddRect(ImTrunc(clip_rect.Min), ImTrunc(clip_rect.Max), IM_COL32(255, 0, 255, 255)) -- In pink: clipping rectangle submitted to GPU
                    fg_draw_list:AddRect(ImTrunc(vtxs_rect.Min), ImTrunc(vtxs_rect.Max), IM_COL32(0, 255, 255, 255)) -- In cyan: bounding box of triangles
                end
            end
            if ImGui.IsItemHovered() and (cfg.ShowDrawCmdMesh or cfg.ShowDrawCmdBoundingBoxes) then ShowMesh(cfg.ShowDrawCmdMesh, cfg.ShowDrawCmdBoundingBoxes) end
            if open then
                ImGui.Selectable(string.format("Mesh: ElemCount: %d, VtxOffset: +%d, IdxOffset: +%d", pcmd.ElemCount, pcmd.VtxOffset, pcmd.IdxOffset))
                if ImGui.IsItemHovered() then ShowMesh(true, false) end
                ImGui.TreePop()
            end
        end
    end
    ImGui.TreePop()
end

-- [DEBUG] Display contents of ImGuiTabBar
function ImGui.DebugNodeTabBar(tab_bar, label)
    -- Standalone tab bars (not associated to docking/windows functionality) currently hold no discernible strings.
    local g = ImGui.GetCurrentContext()
    local is_active = (tab_bar.PrevFrameVisible >= ImGui.GetFrameCount() - 2)
    local names = {}
    for tab_n = 1, math.min(tab_bar.Tabs.Size, 3) do
        local tab = tab_bar.Tabs.Data[tab_n]
        names[#names + 1] = "'" .. (ImGui.TabBarGetTabName and ImGui.TabBarGetTabName(tab_bar, tab) or "?") .. "'"
    end
    local buf = string.format("%s 0x%08X (%d tabs)%s  { %s%s", label, tab_bar.ID, tab_bar.Tabs.Size, is_active and "" or " *Inactive*", table.concat(names, ", "), (tab_bar.Tabs.Size > 3) and " ... }" or " } ")
    if not is_active then ImGui.PushStyleColor(ImGuiCol.Text, g.Style.Colors[ImGuiCol.TextDisabled]) end
    local open = ImGui.TreeNode(label, "%s", buf)
    if not is_active then ImGui.PopStyleColor() end
    if is_active and ImGui.IsItemHovered() then
        local dl = FG(tab_bar.Window)
        dl:AddRect(tab_bar.BarRect.Min, tab_bar.BarRect.Max, IM_COL32(255, 255, 0, 255))
        dl:AddLine(ImVec2(tab_bar.ScrollingRectMinX, tab_bar.BarRect.Min.y), ImVec2(tab_bar.ScrollingRectMinX, tab_bar.BarRect.Max.y), IM_COL32(0, 255, 0, 255))
        dl:AddLine(ImVec2(tab_bar.ScrollingRectMaxX, tab_bar.BarRect.Min.y), ImVec2(tab_bar.ScrollingRectMaxX, tab_bar.BarRect.Max.y), IM_COL32(0, 255, 0, 255))
    end
    if open then
        for tab_n, tab in tab_bar.Tabs:iter() do
            ImGui.PushID(tab_n)
            if ImGui.SmallButton("<") and ImGui.TabBarQueueReorder then ImGui.TabBarQueueReorder(tab_bar, tab, -1) end ImGui.SameLine(0, 2)
            if ImGui.SmallButton(">") and ImGui.TabBarQueueReorder then ImGui.TabBarQueueReorder(tab_bar, tab, 1) end ImGui.SameLine()
            ImGui.Text("%02d%s Tab 0x%08X '%s' Offset: %.2f, Width: %.2f/%.2f", tab_n - 1, (tab.ID == tab_bar.SelectedTabId) and "*" or " ", tab.ID,
                ImGui.TabBarGetTabName and ImGui.TabBarGetTabName(tab_bar, tab) or "?", tab.Offset, tab.Width, tab.ContentWidth)
            ImGui.PopID()
        end
        ImGui.TreePop()
    end
end

local function SizingDesc(f)
    local TF = ImGuiTableFlags
    f = bit32.band(f, TF.SizingMask_)
    if f == TF.SizingFixedFit then return "FixedFit" elseif f == TF.SizingFixedSame then return "FixedSame"
    elseif f == TF.SizingStretchProp then return "StretchProp" elseif f == TF.SizingStretchSame then return "StretchSame" end
    return "N/A"
end

function ImGui.DebugNodeTableSettings(settings, tbl)
    local open = ImGui.TreeNode(tostring(settings), "Settings 0x%08X (%d columns)", settings.ID, settings.ColumnsCount)
    local hovered = ImGui.IsItemHovered()
    if hovered and tbl == nil and settings.ID ~= 0 then tbl = ImGui.TableFindByID(settings.ID) end
    if hovered and tbl ~= nil then YellowRect(tbl.OuterWindow, tbl.OuterRect.Min, tbl.OuterRect.Max) end
    if open then
        ImGui.BulletText("SaveFlags: 0x%08X", settings.SaveFlags)
        ImGui.BulletText("ColumnsCount: %d (max %d)", settings.ColumnsCount, settings.ColumnsCountMax)
        for n = 0, settings.ColumnsCount - 1 do
            local c = settings.Columns[n]
            local dir = (c.SortOrder ~= -1) and c.SortDirection or ImGuiSortDirection.None
            ImGui.BulletText("Column %d Order %d SortOrder %2d %s Vis %d %s %7.3f ID 0x%08X", n, c.DisplayOrder, c.SortOrder,
                (dir == ImGuiSortDirection.Ascending) and "Asc" or ((dir == ImGuiSortDirection.Descending) and "Des" or "---"), c.IsEnabled, (c.IsStretch ~= 0) and "Weight" or "Width ", c.WidthOrWeight, c.ID)
        end
        ImGui.TreePop()
    end
end

function ImGui.DebugNodeTable(tbl)
    local g = ImGui.GetCurrentContext()
    local is_active = (tbl.LastFrameActive >= g.FrameCount - 2) -- Note that fully clipped early out scrolling tables will appear as inactive here.
    if not is_active then ImGui.PushStyleColor(ImGuiCol.Text, g.Style.Colors[ImGuiCol.TextDisabled]) end
    local open = ImGui.TreeNode(tostring(tbl), "Table 0x%08X (%d columns, in '%s')%s", tbl.ID, tbl.ColumnsCount, tbl.OuterWindow and tbl.OuterWindow.Name or "?", is_active and "" or " *Inactive*")
    if not is_active then ImGui.PopStyleColor() end
    if ImGui.IsItemHovered() then YellowRect(tbl.OuterWindow, tbl.OuterRect.Min, tbl.OuterRect.Max) end
    if not open then return end
    if tbl.InstanceCurrent > 0 then ImGui.Text("** %d instances of same table! Some data below will refer to last instance.", tbl.InstanceCurrent + 1) end
    local clear_settings = ImGui.SmallButton("Clear settings")
    ImGui.BulletText("OuterRect: Pos: (%.1f,%.1f) Size: (%.1f,%.1f) Sizing: '%s'", tbl.OuterRect.Min.x, tbl.OuterRect.Min.y, tbl.OuterRect:GetWidth(), tbl.OuterRect:GetHeight(), SizingDesc(tbl.Flags))
    ImGui.BulletText("ColumnsGivenWidth: %.1f, ColumnsAutoFitWidth: %.1f, InnerWidth: %.1f%s", tbl.ColumnsGivenWidth, tbl.ColumnsAutoFitWidth, tbl.InnerWidth, (tbl.InnerWidth == 0.0) and " (auto)" or "")
    ImGui.BulletText("CellPaddingX: %.1f, CellSpacingX: %.1f/%.1f, OuterPaddingX: %.1f", tbl.CellPaddingX, tbl.CellSpacingX1, tbl.CellSpacingX2, tbl.OuterPaddingX)
    ImGui.BulletText("HoveredColumnBody: %d, HoveredColumnBorder: %d", tbl.HoveredColumnBody, tbl.HoveredColumnBorder)
    ImGui.BulletText("ResizedColumn: %d, HeldHeaderColumn: %d, ReorderColumn: %d", tbl.LastResizedColumn, tbl.LastHeldHeaderColumn, tbl.ReorderColumn)
    for n = 0, tbl.InstanceCurrent do
        local inst = ImGui.TableGetInstanceData(tbl, n)
        ImGui.BulletText("Instance %d: HoveredRow: %d, LastOuterHeight: %.2f", n, inst.HoveredRowLast, inst.LastOuterHeight)
    end
    local sum_weights = 0.0
    for n = 0, tbl.ColumnsCount - 1 do
        if bit32.band(tbl.Columns[n].Flags, ImGuiTableColumnFlags.WidthStretch) ~= 0 then sum_weights = sum_weights + tbl.Columns[n].StretchWeight end
    end
    for n = 0, tbl.ColumnsCount - 1 do
        local c = tbl.Columns[n]
        local CF = ImGuiTableColumnFlags
        local buf = string.format(
            "Column %d order %d '%s': offset %+.2f to %+.2f%s\nEnabled: %d, VisibleX/Y: %d/%d, RequestOutput: %d, SkipItems: %d, DrawChannels: %d,%d\n" ..
            "WidthGiven: %.1f, Request/Auto: %.1f/%.1f, StretchWeight: %.3f (%.1f%%)\nMinX: %.1f, MaxX: %.1f (%+.1f), ClipRect: %.1f to %.1f (+%.1f)\n" ..
            "ContentWidth: %.1f,%.1f, HeadersUsed/Ideal %.1f/%.1f\nSort: %d%s, UserData: 0x%08X, Flags: 0x%04X: %s%s%s..",
            n, c.DisplayOrder, ImGui.TableGetColumnName(tbl, n) or "", c.MinX - tbl.WorkRect.Min.x, c.MaxX - tbl.WorkRect.Min.x, (n < tbl.FreezeColumnsRequest) and " (Frozen)" or "",
            B(c.IsEnabled), B(c.IsVisibleX), B(c.IsVisibleY), B(c.IsRequestOutput), B(c.IsSkipItems), c.DrawChannelFrozen, c.DrawChannelUnfrozen,
            c.WidthGiven, c.WidthRequest, c.WidthAuto, c.StretchWeight, (c.StretchWeight > 0.0 and sum_weights > 0) and (c.StretchWeight / sum_weights) * 100.0 or 0.0,
            c.MinX, c.MaxX, c.MaxX - c.MinX, c.ClipRect.Min.x, c.ClipRect.Max.x, c.ClipRect.Max.x - c.ClipRect.Min.x,
            c.ContentMaxXFrozen - c.WorkMinX, c.ContentMaxXUnfrozen - c.WorkMinX, c.ContentMaxXHeadersUsed - c.WorkMinX, c.ContentMaxXHeadersIdeal - c.WorkMinX,
            c.SortOrder, (c.SortDirection == ImGuiSortDirection.Ascending) and " (Asc)" or ((c.SortDirection == ImGuiSortDirection.Descending) and " (Des)" or ""), tonumber(c.UserData) or 0, c.Flags,
            (bit32.band(c.Flags, CF.WidthStretch) ~= 0) and "WidthStretch " or "", (bit32.band(c.Flags, CF.WidthFixed) ~= 0) and "WidthFixed " or "", (bit32.band(c.Flags, CF.NoResize) ~= 0) and "NoResize " or "")
        ImGui.Bullet()
        ImGui.Selectable(buf)
        if ImGui.IsItemHovered() then YellowRect(tbl.OuterWindow, ImVec2(c.MinX, tbl.OuterRect.Min.y), ImVec2(c.MaxX, tbl.OuterRect.Max.y)) end
    end
    local settings = ImGui.TableGetBoundSettings(tbl)
    if settings then ImGui.DebugNodeTableSettings(settings, tbl) end
    if clear_settings then tbl.IsResetAllRequest = true end -- Queue a call to TableResetSettings()
    ImGui.TreePop()
end

local function DebugNodeDockNodeFlags(flags, label, enabled)
    local D = ImGuiDockNodeFlags
    ImGui.PushID(label)
    ImGui.PushStyleVar(ImGuiStyleVar.FramePadding, ImVec2(0.0, 0.0))
    ImGui.Text("%s:", label)
    if not enabled then ImGui.BeginDisabled() end
    for _, n in ipairs({ "NoResize", "NoResizeX", "NoResizeY", "NoTabBar", "HiddenTabBar", "NoWindowMenuButton", "NoCloseButton", "DockedWindowsInFocusRoute",
        "NoDocking", "NoDockingSplit", "NoDockingSplitOther", "NoDockingOverMe", "NoDockingOverOther", "NoDockingOverEmpty", "NoUndocking" }) do
        if D[n] then _, flags = ImGui.CheckboxFlags(n, flags, D[n]) end
    end
    if not enabled then ImGui.EndDisabled() end
    ImGui.PopStyleVar()
    ImGui.PopID()
    return flags
end

-- [DEBUG] Display contents of ImDockNode
function ImGui.DebugNodeDockNode(node, label)
    local g = ImGui.GetCurrentContext()
    local is_alive = (g.FrameCount - node.LastFrameAlive < 2)    -- Submitted with ImGuiDockNodeFlags.KeepAliveOnly
    local is_active = (g.FrameCount - node.LastFrameActive < 2)  -- Submitted
    if not is_alive then ImGui.PushStyleColor(ImGuiCol.Text, g.Style.Colors[ImGuiCol.TextDisabled]) end
    local tree_node_flags = node.IsFocused and ImGuiTreeNodeFlags.Selected or ImGuiTreeNodeFlags.None
    local open
    if node.Windows.Size > 0 then
        open = ImGui.TreeNodeEx(node.ID, tree_node_flags, "%s 0x%04X%s: %d windows (vis: '%s')", label, node.ID, node.IsVisible and "" or " (hidden)", node.Windows.Size, node.VisibleWindow and node.VisibleWindow.Name or "NULL")
    else
        local kind = (node.SplitAxis == ImGuiAxis.X) and "horizontal split" or ((node.SplitAxis == ImGuiAxis.Y) and "vertical split" or "empty")
        open = ImGui.TreeNodeEx(node.ID, tree_node_flags, "%s 0x%04X%s: %s (vis: '%s')", label, node.ID, node.IsVisible and "" or " (hidden)", kind, node.VisibleWindow and node.VisibleWindow.Name or "NULL")
    end
    if not is_alive then ImGui.PopStyleColor() end
    if is_active and ImGui.IsItemHovered() then
        local window = node.HostWindow or node.VisibleWindow
        if window then YellowRect(window, node.Pos, node.Pos + node.Size) end
    end
    if open then
        ImGui.BulletText("Pos (%.0f,%.0f), Size (%.0f, %.0f) Ref (%.0f, %.0f)", node.Pos.x, node.Pos.y, node.Size.x, node.Size.y, node.SizeRef.x, node.SizeRef.y)
        ImGui.DebugNodeWindow(node.HostWindow, "HostWindow")
        ImGui.DebugNodeWindow(node.VisibleWindow, "VisibleWindow")
        ImGui.BulletText("SelectedTabID: 0x%08X, LastFocusedNodeID: 0x%08X", node.SelectedTabId, node.LastFocusedNodeId)
        ImGui.BulletText("Misc:%s%s%s%s%s%s%s", node:IsDockSpace() and " IsDockSpace" or "", node:IsCentralNode() and " IsCentralNode" or "",
            is_alive and " IsAlive" or "", is_active and " IsActive" or "", node.IsFocused and " IsFocused" or "", node.WantLockSizeOnce and " WantLockSizeOnce" or "", node.HasCentralNodeChild and " HasCentralNodeChild" or "")
        if ImGui.TreeNode("flags", "Flags Merged: 0x%04X, Local: 0x%04X, InWindows: 0x%04X, Shared: 0x%04X", node.MergedFlags, node.LocalFlags, node.LocalFlagsInWindows, node.SharedFlags) then
            if ImGui.BeginTable("flags", 4) then
                ImGui.TableNextColumn(); DebugNodeDockNodeFlags(node.MergedFlags, "MergedFlags", false)
                ImGui.TableNextColumn(); node.LocalFlags = DebugNodeDockNodeFlags(node.LocalFlags, "LocalFlags", true)
                ImGui.TableNextColumn(); DebugNodeDockNodeFlags(node.LocalFlagsInWindows, "LocalFlagsInWindows", false)
                ImGui.TableNextColumn(); node.SharedFlags = DebugNodeDockNodeFlags(node.SharedFlags, "SharedFlags", true)
                ImGui.EndTable()
            end
            ImGui.TreePop()
        end
        if node.ParentNode then ImGui.DebugNodeDockNode(node.ParentNode, "ParentNode") end
        if node.ChildNodes[0] then ImGui.DebugNodeDockNode(node.ChildNodes[0], "Child[0]") end
        if node.ChildNodes[1] then ImGui.DebugNodeDockNode(node.ChildNodes[1], "Child[1]") end
        if node.TabBar then ImGui.DebugNodeTabBar(node.TabBar, "TabBar") end
        ImGui.DebugNodeWindowsList(node.Windows, "Windows")
        ImGui.TreePop()
    end
end

function ImGui.DebugNodeWindow(window, label)
    if window == nil then
        ImGui.BulletText("%s: NULL", label)
        return
    end
    local g = ImGui.GetCurrentContext()
    local is_active = window.WasActive
    local tree_node_flags = (window == g.NavWindow) and ImGuiTreeNodeFlags.Selected or ImGuiTreeNodeFlags.None
    if not is_active then ImGui.PushStyleColor(ImGuiCol.Text, g.Style.Colors[ImGuiCol.TextDisabled]) end
    local open = ImGui.TreeNodeEx(label, tree_node_flags, "%s '%s'%s", label, window.Name, is_active and "" or " *Inactive*")
    if not is_active then ImGui.PopStyleColor() end
    if ImGui.IsItemHovered() and is_active then YellowRect(window, window.Pos, window.Pos + window.Size) end
    if not open then return end
    if window.MemoryCompacted then ImGui.TextDisabled("Note: some memory buffers have been compacted/freed.") end
    local W = ImGuiWindowFlags
    local flags = window.Flags
    local function F(f, s) return (bit32.band(flags, f) ~= 0) and s or "" end
    ImGui.DebugNodeDrawList(window, window.Viewport, window.DrawList, "DrawList")
    ImGui.BulletText("Pos: (%.1f,%.1f), Size: (%.1f,%.1f), ContentSize (%.1f,%.1f) Ideal (%.1f,%.1f)", window.Pos.x, window.Pos.y, window.Size.x, window.Size.y, window.ContentSize.x, window.ContentSize.y, window.ContentSizeIdeal.x, window.ContentSizeIdeal.y)
    ImGui.BulletText("Flags: 0x%08X (%s%s%s%s%s%s%s%s%s..)", flags, F(W.ChildWindow, "Child "), F(W.Tooltip, "Tooltip "), F(W.Popup, "Popup "), F(W.Modal, "Modal "), F(W.ChildMenu, "ChildMenu "),
        F(W.NoSavedSettings, "NoSavedSettings "), F(W.NoMouseInputs, "NoMouseInputs"), F(W.NoNavInputs, "NoNavInputs"), F(W.AlwaysAutoResize, "AlwaysAutoResize"))
    if bit32.band(flags, W.ChildWindow) ~= 0 then
        local cf = window.ChildFlags or 0
        local C = ImGuiChildFlags
        ImGui.BulletText("ChildFlags: 0x%08X (%s%s%s%s..)", cf, (bit32.band(cf, C.Borders) ~= 0) and "Borders " or "", (bit32.band(cf, C.ResizeX) ~= 0) and "ResizeX " or "",
            (bit32.band(cf, C.ResizeY) ~= 0) and "ResizeY " or "", (bit32.band(cf, C.NavFlattened) ~= 0) and "NavFlattened " or "")
    end
    ImGui.BulletText("WindowClassId: 0x%08X", window.WindowClass and window.WindowClass.ClassId or 0)
    ImGui.BulletText("Scroll: (%.2f/%.2f,%.2f/%.2f) Scrollbar:%s%s", window.Scroll.x, window.ScrollMax.x, window.Scroll.y, window.ScrollMax.y, window.ScrollbarX and "X" or "", window.ScrollbarY and "Y" or "")
    ImGui.BulletText("Active: %d/%d, WriteAccessed: %d, BeginOrderWithinContext: %d", B(window.Active), B(window.WasActive), B(window.WriteAccessed), (window.Active or window.WasActive) and window.BeginOrderWithinContext or -1)
    ImGui.BulletText("Appearing: %d, Hidden: %d (CanSkip %d Cannot %d), SkipItems: %d", B(window.Appearing), B(window.Hidden), window.HiddenFramesCanSkipItems, window.HiddenFramesCannotSkipItems, B(window.SkipItems))
    for layer = 0, 1 do
        local r = window.NavRectRel[layer]
        if r.Min.x >= r.Max.x and r.Min.y >= r.Max.y then
            ImGui.BulletText("NavLastIds[%d]: 0x%08X", layer, window.NavLastIds[layer])
        else
            ImGui.BulletText("NavLastIds[%d]: 0x%08X at +(%.1f,%.1f)(%.1f,%.1f)", layer, window.NavLastIds[layer], r.Min.x, r.Min.y, r.Max.x, r.Max.y)
        end
    end
    ImGui.BulletText("NavLayersActiveMask: %X, NavLastChildNavWindow: %s", window.DC.NavLayersActiveMask, window.NavLastChildNavWindow and window.NavLastChildNavWindow.Name or "NULL")
    ImGui.BulletText("Viewport: %d%s, ViewportId: 0x%08X, ViewportPos: (%.1f,%.1f)", window.Viewport and (window.Viewport.Idx or 0) or -1, window.ViewportOwned and " (Owned)" or "", window.ViewportId or 0, window.ViewportPos.x, window.ViewportPos.y)
    ImGui.BulletText("DockId: 0x%04X, DockOrder: %d, Act: %d, Vis: %d", window.DockId or 0, window.DockOrder or -1, B(window.DockIsActive), B(window.DockTabIsVisible))
    if window.DockNode or window.DockNodeAsHost then
        ImGui.DebugNodeDockNode(window.DockNodeAsHost or window.DockNode, window.DockNodeAsHost and "DockNodeAsHost" or "DockNode")
    end
    if window.RootWindow ~= window then ImGui.DebugNodeWindow(window.RootWindow, "RootWindow") end
    if window.RootWindowDockTree and window.RootWindowDockTree ~= window.RootWindow then ImGui.DebugNodeWindow(window.RootWindowDockTree, "RootWindowDockTree") end
    if window.ParentWindow ~= nil then ImGui.DebugNodeWindow(window.ParentWindow, "ParentWindow") end
    if window.ParentWindowForFocusRoute ~= nil then ImGui.DebugNodeWindow(window.ParentWindowForFocusRoute, "ParentWindowForFocusRoute") end
    if window.DC.ChildWindows.Size > 0 then ImGui.DebugNodeWindowsList(window.DC.ChildWindows, "ChildWindows") end
    if window.ColumnsStorage.Size > 0 and ImGui.TreeNode("Columns", "Columns sets (%d)", window.ColumnsStorage.Size) then
        for _, columns in window.ColumnsStorage:iter() do ImGui.DebugNodeColumns(columns) end
        ImGui.TreePop()
    end
    ImGui.DebugNodeStorage(window.StateStorage, "Storage")
    ImGui.TreePop()
end

function ImGui.DebugNodeWindowSettings(settings)
    if settings.WantDelete then ImGui.BeginDisabled() end
    ImGui.BulletText("0x%08X \"%s\" Pos (%d,%d) Size (%d,%d) Collapsed=%d", settings.ID, settings.Name or "", settings.Pos.x, settings.Pos.y, settings.Size.x, settings.Size.y, B(settings.Collapsed))
    if settings.WantDelete then ImGui.EndDisabled() end
end

function ImGui.DebugNodeWindowsList(windows, label)
    if not ImGui.TreeNode(label, "%s (%d)", label, windows.Size) then return end
    for i = windows.Size, 1, -1 do -- Iterate front to back
        ImGui.PushID(tostring(windows.Data[i]))
        ImGui.DebugNodeWindow(windows.Data[i], "Window")
        ImGui.PopID()
    end
    ImGui.TreePop()
end

-- FIXME-OPT: This is technically suboptimal, but it is simpler this way.
function ImGui.DebugNodeWindowsListByBeginStackParent(windows, first, last, parent_in_begin_stack)
    for i = first, last do
        local window = windows[i]
        if window.ParentWindowInBeginStack == parent_in_begin_stack then
            local buf = string.format("[%04d] Window", window.BeginOrderWithinContext)
            -- ImGui.BulletText("[%04d] Window '%s'", window.BeginOrderWithinContext, window.Name)
            ImGui.DebugNodeWindow(window, buf)
            ImGui.TreePush(buf)
            ImGui.DebugNodeWindowsListByBeginStackParent(windows, i + 1, last, window)
            ImGui.TreePop()
        end
    end
end

function ImGui.DebugNodeViewport(viewport)
    local g = ImGui.GetCurrentContext()
    ImGui.SetNextItemOpen(true, ImGuiCond.Once)
    local open = ImGui.TreeNode(viewport.ID, "Viewport #%d, ID: 0x%08X, Parent: 0x%08X, Window: \"%s\"", viewport.Idx or 0, viewport.ID, viewport.ParentViewportId or 0, viewport.Window and viewport.Window.Name or "N/A")
    if ImGui.IsItemHovered() then g.DebugMetricsConfig.HighlightViewportID = viewport.ID end
    if open then
        ImGui.BulletText("Main Pos: (%.0f,%.0f), Size: (%.0f,%.0f)\nFrameBufferScale: (%.2f,%.2f)\nWorkArea Inset Left: %.0f Top: %.0f, Right: %.0f, Bottom: %.0f\nMonitor: %d, DpiScale: %.0f%%",
            viewport.Pos.x, viewport.Pos.y, viewport.Size.x, viewport.Size.y, viewport.FramebufferScale and viewport.FramebufferScale.x or 1, viewport.FramebufferScale and viewport.FramebufferScale.y or 1,
            viewport.WorkInsetMin.x, viewport.WorkInsetMin.y, viewport.WorkInsetMax.x, viewport.WorkInsetMax.y, viewport.PlatformMonitor or 0, (viewport.DpiScale or 1) * 100.0)
        ImGui.BulletText("Flags: 0x%04X", viewport.Flags or 0)
        if viewport.DrawDataP then
            for _, draw_list in viewport.DrawDataP.CmdLists:iter() do ImGui.DebugNodeDrawList(nil, viewport, draw_list, "DrawList") end
        end
        ImGui.TreePop()
    end
end

-- Helper tool to diagnose between text encoding issues and font loading issues. Pass your UTF-8 string and verify that there are correct.
function ImGui.DebugTextEncoding(str)
    ImGui.Text("Text: \"%s\"", str)
    if not ImGui.BeginTable("##DebugTextEncoding", 4, bit32.bor(ImGuiTableFlags.Borders, ImGuiTableFlags.RowBg, ImGuiTableFlags.SizingFixedFit, ImGuiTableFlags.Resizable)) then return end
    ImGui.TableSetupColumn("Offset")
    ImGui.TableSetupColumn("UTF-8")
    ImGui.TableSetupColumn("Glyph")
    ImGui.TableSetupColumn("Codepoint")
    ImGui.TableHeadersRow()
    for pos, c in utf8.codes(str) do
        local nxt = utf8.offset(str, 2, pos) or (#str + 1)
        ImGui.TableNextColumn()
        ImGui.Text("%d", pos - 1)
        ImGui.TableNextColumn()
        for b = pos, nxt - 1 do
            if b > pos then ImGui.SameLine() end
            ImGui.Text("0x%02X", string.byte(str, b))
        end
        ImGui.TableNextColumn()
        ImGui.TextUnformatted(string.sub(str, pos, nxt - 1))
        ImGui.TableNextColumn()
        ImGui.Text("U+%04X", c)
    end
    ImGui.EndTable()
end

-- Debugging enums
local WRT_Names = { "OuterRect", "OuterRectClipped", "InnerRect", "InnerClipRect", "WorkRect", "Content", "ContentIdeal", "ContentRegionRect" }
local TRT_Names = { "OuterRect", "InnerRect", "WorkRect", "HostClipRect", "InnerClipRect", "BackgroundClipRect", "ColumnsRect", "ColumnsWorkRect", "ColumnsClipRect",
    "ColumnsContentHeadersUsed", "ColumnsContentHeadersIdeal", "ColumnsContentFrozen", "ColumnsContentUnfrozen" }
local TRT_ColumnsRect = 6

local function GetWindowRect(window, t)
    if t == 0 then return window:Rect()
    elseif t == 1 then return window.OuterRectClipped
    elseif t == 2 then return window.InnerRect
    elseif t == 3 then return window.InnerClipRect
    elseif t == 4 then return window.WorkRect
    elseif t == 5 then local m = window.InnerRect.Min - window.Scroll + window.WindowPadding; return ImRect(m, m + window.ContentSize)
    elseif t == 6 then local m = window.InnerRect.Min - window.Scroll + window.WindowPadding; return ImRect(m, m + window.ContentSizeIdeal)
    else return window.ContentRegionRect end
end

local function GetTableRect(tbl, t, n)
    local inst = ImGui.TableGetInstanceData(tbl, tbl.InstanceCurrent) -- Always using last submitted instance
    if t == 0 then return tbl.OuterRect elseif t == 1 then return tbl.InnerRect elseif t == 2 then return tbl.WorkRect
    elseif t == 3 then return tbl.HostClipRect elseif t == 4 then return tbl.InnerClipRect elseif t == 5 then return tbl.BgClipRect end
    local c = tbl.Columns[n]
    if t == 6 then return ImRect(c.MinX, tbl.InnerClipRect.Min.y, c.MaxX, tbl.InnerClipRect.Min.y + inst.LastOuterHeight)
    elseif t == 7 then return ImRect(c.WorkMinX, tbl.WorkRect.Min.y, c.WorkMaxX, tbl.WorkRect.Max.y)
    elseif t == 8 then return c.ClipRect
    elseif t == 9 then return ImRect(c.WorkMinX, tbl.InnerClipRect.Min.y, c.ContentMaxXHeadersUsed, tbl.InnerClipRect.Min.y + inst.LastTopHeadersRowHeight) -- Note: y1/y2 not always accurate
    elseif t == 10 then return ImRect(c.WorkMinX, tbl.InnerClipRect.Min.y, c.ContentMaxXHeadersIdeal, tbl.InnerClipRect.Min.y + inst.LastTopHeadersRowHeight)
    elseif t == 11 then return ImRect(c.WorkMinX, tbl.InnerClipRect.Min.y, c.ContentMaxXFrozen, tbl.InnerClipRect.Min.y + inst.LastFrozenHeight)
    else return ImRect(c.WorkMinX, tbl.InnerClipRect.Min.y + inst.LastFrozenHeight, c.ContentMaxXUnfrozen, tbl.InnerClipRect.Max.y) end
end

local function ForEachTable(g, fn)
    for i = 0, g.Tables:GetMapSize() - 1 do
        local t = g.Tables:GetByIndex(i)
        if t then fn(t) end
    end
end

local MetricsEncodingBuf = nil
local MetricsDockRootOnly = true
function ImGui.ShowMetricsWindow(p_open)
    local g = ImGui.GetCurrentContext()
    local io = g.IO
    local cfg = g.DebugMetricsConfig
    if cfg.ShowDebugLog then cfg.ShowDebugLog = ImGui.ShowDebugLogWindow(cfg.ShowDebugLog) end
    if cfg.ShowIDStackTool then cfg.ShowIDStackTool = ImGui.ShowIDStackToolWindow(cfg.ShowIDStackTool) end

    local visible
    p_open, visible = ImGui.Begin("Dear ImGui Metrics/Debugger", p_open)
    if not visible or ImGui.GetCurrentWindow().BeginCount > 1 then
        ImGui.End()
        return p_open
    end

    -- Basic info
    ImGui.Text("Dear ImGui %s (%d)", IMGUI_VERSION, IMGUI_VERSION_NUM)
    ImGui.Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0 / math.max(io.Framerate, 0.0001), io.Framerate)
    ImGui.Text("%d vertices, %d indices (%d triangles)", io.MetricsRenderVertices, io.MetricsRenderIndices, math.floor(io.MetricsRenderIndices / 3))
    ImGui.Text("%d visible windows, %d current allocations", io.MetricsRenderWindows, g.DebugAllocInfo.TotalAllocCount - g.DebugAllocInfo.TotalFreeCount)
    ImGui.Separator()

    if cfg.ShowWindowsRectsType == nil or cfg.ShowWindowsRectsType < 0 then cfg.ShowWindowsRectsType = 4 end
    if cfg.ShowTablesRectsType == nil or cfg.ShowTablesRectsType < 0 then cfg.ShowTablesRectsType = 2 end

    -- Tools
    if ImGui.TreeNode("Tools") then
        ImGui.SeparatorText("Visualize")
        _, cfg.ShowDebugLog = ImGui.Checkbox("Show Debug Log", cfg.ShowDebugLog == true)
        ImGui.SameLine(); MetricsHelpMarker("You can also call ImGui::ShowDebugLogWindow() from your code.")
        _, cfg.ShowIDStackTool = ImGui.Checkbox("Show ID Stack Tool", cfg.ShowIDStackTool == true)
        ImGui.SameLine(); MetricsHelpMarker("You can also call ImGui::ShowIDStackToolWindow() from your code.")
        _, cfg.ShowWindowsBeginOrder = ImGui.Checkbox("Show windows begin order", cfg.ShowWindowsBeginOrder == true)
        _, cfg.ShowWindowsRects = ImGui.Checkbox("Show windows rectangles", cfg.ShowWindowsRects == true)
        ImGui.SameLine()
        ImGui.SetNextItemWidth(ImGui.GetFontSize() * 12)
        local changed
        cfg.ShowWindowsRectsType, changed = ImGui.Combo("##show_windows_rect_type", cfg.ShowWindowsRectsType, WRT_Names, #WRT_Names, #WRT_Names)
        cfg.ShowWindowsRects = cfg.ShowWindowsRects or changed
        if cfg.ShowWindowsRects and g.NavWindow ~= nil then
            ImGui.BulletText("'%s':", g.NavWindow.Name)
            ImGui.Indent()
            for rect_n = 0, #WRT_Names - 1 do
                local r = GetWindowRect(g.NavWindow, rect_n)
                ImGui.Text("(%6.1f,%6.1f) (%6.1f,%6.1f) Size (%6.1f,%6.1f) %s", r.Min.x, r.Min.y, r.Max.x, r.Max.y, r:GetWidth(), r:GetHeight(), WRT_Names[rect_n + 1])
            end
            ImGui.Unindent()
        end
        _, cfg.ShowTablesRects = ImGui.Checkbox("Show tables rectangles", cfg.ShowTablesRects == true)
        ImGui.SameLine()
        ImGui.SetNextItemWidth(ImGui.GetFontSize() * 12)
        cfg.ShowTablesRectsType, changed = ImGui.Combo("##show_table_rects_type", cfg.ShowTablesRectsType, TRT_Names, #TRT_Names, #TRT_Names)
        cfg.ShowTablesRects = cfg.ShowTablesRects or changed
        _, g.DebugShowGroupRects = ImGui.Checkbox("Show groups rectangles", g.DebugShowGroupRects == true) -- Storing in context as this is used by group code and prefers to be in hot-data

        ImGui.SeparatorText("Validate")
        _, io.ConfigDebugBeginReturnValueLoop = ImGui.Checkbox("Debug Begin/BeginChild return value", io.ConfigDebugBeginReturnValueLoop == true)
        ImGui.SameLine(); MetricsHelpMarker("Some calls to Begin()/BeginChild() will return false.\n\nWill cycle through window depths then repeat. Windows should be flickering while running.")
        _, cfg.ShowTextEncodingViewer = ImGui.Checkbox("UTF-8 Encoding viewer", cfg.ShowTextEncodingViewer == true)
        ImGui.SameLine(); MetricsHelpMarker("You can also call ImGui::DebugTextEncoding() from your code with a given string to test that your UTF-8 encoding settings are correct.")
        if cfg.ShowTextEncodingViewer then
            MetricsEncodingBuf = MetricsEncodingBuf or DemoBuf("", 64)
            ImGui.SetNextItemWidth(-FLT_MIN)
            ImGui.InputText("##DebugTextEncodingBuf", MetricsEncodingBuf, 64)
            local str = DemoBufStr(MetricsEncodingBuf)
            if str ~= "" then ImGui.DebugTextEncoding(str) end
        end
        ImGui.TreePop()
    end

    -- Windows
    if ImGui.TreeNode("Windows", "Windows (%d)", g.Windows.Size) then
        -- ImGui.SetNextItemOpen(true, ImGuiCond.Once)
        ImGui.DebugNodeWindowsList(g.Windows, "By display order")
        ImGui.DebugNodeWindowsList(g.WindowsFocusOrder, "By focus order (root windows)")
        if ImGui.TreeNode("By submission order (begin stack)") then
            -- Here we display windows in their submitted order/hierarchy, however note that the Begin stack doesn't constitute a Parent<>Child relationship!
            local tmp = {}
            for _, window in g.Windows:iter() do
                if window.LastFrameActive + 1 >= g.FrameCount then tmp[#tmp + 1] = window end
            end
            table.sort(tmp, function(a, b) return a.BeginOrderWithinContext < b.BeginOrderWithinContext end)
            ImGui.DebugNodeWindowsListByBeginStackParent(tmp, 1, #tmp, nil)
            ImGui.TreePop()
        end
        ImGui.TreePop()
    end

    -- DrawLists
    local drawlist_count = 0
    for _, viewport in g.Viewports:iter() do drawlist_count = drawlist_count + viewport.DrawDataP.CmdLists.Size end
    if ImGui.TreeNode("DrawLists", "DrawLists (%d)", drawlist_count) then
        _, cfg.ShowDrawCmdMesh = ImGui.Checkbox("Show ImDrawCmd mesh when hovering", cfg.ShowDrawCmdMesh ~= false)
        _, cfg.ShowDrawCmdBoundingBoxes = ImGui.Checkbox("Show ImDrawCmd bounding boxes when hovering", cfg.ShowDrawCmdBoundingBoxes ~= false)
        for _, viewport in g.Viewports:iter() do
            local has = false
            for _, draw_list in viewport.DrawDataP.CmdLists:iter() do
                if not has then ImGui.Text("Active DrawLists in Viewport #%d, ID: 0x%08X", viewport.Idx or 0, viewport.ID) end
                has = true
                ImGui.DebugNodeDrawList(nil, viewport, draw_list, "DrawList")
            end
        end
        ImGui.TreePop()
    end

    -- Viewports
    if ImGui.TreeNode("Viewports", "Viewports (%d)", g.Viewports.Size) then
        ImGui.SetNextItemOpen(true, ImGuiCond.Once)
        if ImGui.TreeNode("Windows Minimap") then
            ImGui.RenderViewportsThumbnails()
            ImGui.TreePop()
        end
        cfg.HighlightViewportID = 0
        for _, viewport in g.Viewports:iter() do ImGui.DebugNodeViewport(viewport) end
        ImGui.TreePop()
    end

    -- Details for Fonts
    for i, atlas in g.FontAtlases:iter() do
        if ImGui.TreeNode(tostring(atlas), "Fonts (%d), Textures (%d)", atlas.Fonts.Size, atlas.TexList.Size) then
            ImGui.ShowFontAtlas(atlas)
            ImGui.TreePop()
        end
    end

    -- Details for Popups
    if ImGui.TreeNode("Popups", "Popups (%d)", g.OpenPopupStack.Size) then
        for _, popup_data in g.OpenPopupStack:iter() do
            -- As it's difficult to interact with tree nodes while popups are open, we display everything inline.
            local window = popup_data.Window
            local W = ImGuiWindowFlags
            ImGui.BulletText("PopupID: %08x, Window: '%s' (%s%s), RestoreNavWindow '%s', ParentWindow '%s'", popup_data.PopupId, window and window.Name or "NULL",
                (window and bit32.band(window.Flags, W.ChildWindow) ~= 0) and "Child;" or "", (window and bit32.band(window.Flags, W.ChildMenu) ~= 0) and "Menu;" or "",
                popup_data.RestoreNavWindow and popup_data.RestoreNavWindow.Name or "NULL", (window and window.ParentWindow) and window.ParentWindow.Name or "NULL")
        end
        ImGui.TreePop()
    end

    -- Details for TabBars
    if ImGui.TreeNode("TabBars", "Tab Bars (%d)", g.TabBars.AliveCount) then
        for n = 0, g.TabBars:GetMapSize() - 1 do
            local tab_bar = g.TabBars:GetByIndex(n)
            if tab_bar then
                ImGui.PushID(n)
                ImGui.DebugNodeTabBar(tab_bar, "TabBar")
                ImGui.PopID()
            end
        end
        ImGui.TreePop()
    end

    -- Details for Tables
    if ImGui.TreeNode("Tables", "Tables (%d)", g.Tables.AliveCount) then
        ForEachTable(g, ImGui.DebugNodeTable)
        ImGui.TreePop()
    end

    -- Details for Docking
    if ImGui.TreeNode("Docking") then
        local dc = g.DockContext
        _, MetricsDockRootOnly = ImGui.Checkbox("List root nodes", MetricsDockRootOnly)
        _, cfg.ShowDockingNodes = ImGui.Checkbox("Ctrl shows window dock info", cfg.ShowDockingNodes == true)
        if ImGui.SmallButton("Clear nodes") then ImGui.DockContextClearNodes(g, 0, true) end
        ImGui.SameLine()
        if ImGui.SmallButton("Rebuild all") then dc.WantFullRebuild = true end
        local ids = {}
        for id in pairs(dc.Nodes) do ids[#ids + 1] = id end
        table.sort(ids)
        for _, id in ipairs(ids) do
            local node = dc.Nodes[id]
            if node and (not MetricsDockRootOnly or node:IsRootNode()) then ImGui.DebugNodeDockNode(node, "Node") end
        end
        ImGui.TreePop()
    end

    -- Settings
    if ImGui.TreeNode("Settings") then
        if ImGui.SmallButton("Clear") then ImGui.ClearIniSettings() end
        ImGui.SameLine()
        if ImGui.SmallButton("Save to memory") then ImGui.SaveIniSettingsToMemory() end
        ImGui.SameLine()
        ImGui.TextUnformatted(io.IniFilename and ("\"" .. io.IniFilename .. "\"") or "<NULL>")
        ImGui.Text("SettingsDirtyTimer %.2f", g.SettingsDirtyTimer)
        if ImGui.TreeNode("SettingsHandlers", "Settings handlers: (%d)", g.SettingsHandlers.Size) then
            for _, handler in g.SettingsHandlers:iter() do ImGui.BulletText("\"%s\"", handler.TypeName) end
            ImGui.TreePop()
        end
        if ImGui.TreeNode("SettingsWindows", "Settings packed data: Windows: %d entries", g.SettingsWindows.Size) then
            for _, settings in g.SettingsWindows:iter() do ImGui.DebugNodeWindowSettings(settings) end
            ImGui.TreePop()
        end
        if ImGui.TreeNode("SettingsTables", "Settings packed data: Tables: %d entries", g.SettingsTables.Size) then
            for _, settings in g.SettingsTables:iter() do ImGui.DebugNodeTableSettings(settings, nil) end
            ImGui.TreePop()
        end
        if ImGui.TreeNode("SettingsDocking", "Settings packed data: Docking") then
            local dc = g.DockContext
            ImGui.Text("In SettingsWindows:")
            for _, settings in g.SettingsWindows:iter() do
                if (settings.DockId or 0) ~= 0 then ImGui.BulletText("Window '%s' -> DockId %08X DockOrder=%d", settings.Name or "", settings.DockId, settings.DockOrder or -1) end
            end
            ImGui.Text("In SettingsNodes:")
            for _, settings in dc.NodesSettings:iter() do
                local selected_tab_name = nil
                if (settings.SelectedTabId or 0) ~= 0 then
                    local window = ImGui.FindWindowByID(settings.SelectedTabId)
                    selected_tab_name = window and window.Name or nil
                end
                ImGui.BulletText("Node %08X, Parent %08X, SelectedTab %08X ('%s')", settings.ID, settings.ParentNodeId or 0, settings.SelectedTabId or 0, selected_tab_name or ((settings.SelectedTabId or 0) ~= 0 and "N/A" or ""))
            end
            ImGui.TreePop()
        end
        local ini = g.SettingsIniData or ""
        if ImGui.TreeNode("SettingsIniData", "Settings unpacked data (.ini): %d bytes", #ini) then
            ImGui.InputTextMultiline("##Ini", DemoBuf(ini, #ini + 1), #ini + 1, ImVec2(-FLT_MIN, ImGui.GetTextLineHeight() * 20), ImGuiInputTextFlags.ReadOnly)
            ImGui.TreePop()
        end
        ImGui.TreePop()
    end

    -- Inputs
    if ImGui.TreeNode("Inputs") then
        ImGui.Text("KEYBOARD/GAMEPAD/MOUSE KEYS")
        -- User code should never have to go through such hoops! You can generally iterate between ImGuiKey.NamedKey_BEGIN and ImGuiKey.NamedKey_END.
        ImGui.Indent()
        ImGui.Text("Keys down:")
        for key = ImGuiKey.NamedKey_BEGIN, ImGuiKey.NamedKey_END - 1 do
            if ImGui.IsKeyDown(key) then ImGui.SameLine(); ImGui.Text("\"%s\"", ImGui.GetKeyName(key)) end
        end
        ImGui.Text("Keys pressed:")
        for key = ImGuiKey.NamedKey_BEGIN, ImGuiKey.NamedKey_END - 1 do
            if ImGui.IsKeyPressed(key) then ImGui.SameLine(); ImGui.Text("\"%s\"", ImGui.GetKeyName(key)) end
        end
        ImGui.Text("Keys released:")
        for key = ImGuiKey.NamedKey_BEGIN, ImGuiKey.NamedKey_END - 1 do
            if ImGui.IsKeyReleased(key) then ImGui.SameLine(); ImGui.Text("\"%s\"", ImGui.GetKeyName(key)) end
        end
        ImGui.Text("Keys mods: %s%s%s%s", io.KeyCtrl and "Ctrl " or "", io.KeyShift and "Shift " or "", io.KeyAlt and "Alt " or "", io.KeySuper and "Super " or "")
        ImGui.Unindent()
        ImGui.Text("MOUSE STATE")
        ImGui.Indent()
        if ImGui.IsMousePosValid() then ImGui.Text("Mouse pos: (%g, %g)", io.MousePos.x, io.MousePos.y) else ImGui.Text("Mouse pos: <INVALID>") end
        ImGui.Text("Mouse delta: (%g, %g)", io.MouseDelta.x, io.MouseDelta.y)
        ImGui.Text("Mouse down:")
        for i = 0, 2 do if ImGui.IsMouseDown(i) then ImGui.SameLine(); ImGui.Text("b%d (%.02f secs)", i, io.MouseDownDuration[i]) end end
        ImGui.Text("Mouse clicked:")
        for i = 0, 2 do if ImGui.IsMouseClicked(i) then ImGui.SameLine(); ImGui.Text("b%d (%d)", i, io.MouseClickedCount[i]) end end
        ImGui.Text("Mouse released:")
        for i = 0, 2 do if ImGui.IsMouseReleased(i) then ImGui.SameLine(); ImGui.Text("b%d", i) end end
        ImGui.Text("Mouse wheel: %.1f", io.MouseWheel)
        ImGui.Text("MouseStationaryTimer: %.2f", g.MouseStationaryTimer)
        ImGui.Unindent()
        ImGui.Text("MOUSE WHEELING")
        ImGui.Indent()
        ImGui.Text("WheelingWindow: '%s'", g.WheelingWindow and g.WheelingWindow.Name or "NULL")
        ImGui.Text("WheelingWindowReleaseTimer: %.2f", g.WheelingWindowReleaseTimer or 0)
        ImGui.Text("WheelingAxisAvg[] = { %.3f, %.3f }", g.WheelingAxisAvg.x, g.WheelingAxisAvg.y)
        ImGui.Unindent()
        ImGui.TreePop()
    end

    -- Internal state
    if ImGui.TreeNode("Internal state") then
        local function N(w) return w and w.Name or "NULL" end
        ImGui.Text("WINDOWING")
        ImGui.Indent()
        ImGui.Text("HoveredWindow: '%s'", N(g.HoveredWindow))
        ImGui.Text("HoveredWindow->Root: '%s'", g.HoveredWindow and N(g.HoveredWindow.RootWindowDockTree) or "NULL")
        ImGui.Text("HoveredWindowUnderMovingWindow: '%s'", N(g.HoveredWindowUnderMovingWindow))
        ImGui.Text("HoveredDockNode: 0x%08X", g.DebugHoveredDockNode and g.DebugHoveredDockNode.ID or 0)
        ImGui.Text("MovingWindow: '%s'", N(g.MovingWindow))
        ImGui.Unindent()
        ImGui.Text("ITEMS")
        ImGui.Indent()
        ImGui.Text("ActiveId: 0x%08X/0x%08X (%.2f sec), AllowOverlap: %d", g.ActiveId, g.ActiveIdPreviousFrame, g.ActiveIdTimer, B(g.ActiveIdAllowOverlap))
        ImGui.Text("ActiveIdWindow: '%s'", N(g.ActiveIdWindow))
        ImGui.Text("HoveredId: 0x%08X (%.2f sec), AllowOverlap: %d", g.HoveredIdPreviousFrame, g.HoveredIdTimer, B(g.HoveredIdAllowOverlap)) -- Not displaying g.HoveredId as it is update mid-frame
        ImGui.Text("HoverItemDelayId: 0x%08X, Timer: %.2f, ClearTimer: %.2f", g.HoverItemDelayId or 0, g.HoverItemDelayTimer or 0, g.HoverItemDelayClearTimer or 0)
        ImGui.Text("DragDrop: %d, SourceId = 0x%08X, Payload \"%s\"", B(g.DragDropActive), g.DragDropPayload.SourceId or 0, tostring(g.DragDropPayload.DataType or ""))
        ImGui.Unindent()
        ImGui.Text("NAV,FOCUS")
        ImGui.Indent()
        ImGui.Text("NavWindow: '%s'", N(g.NavWindow))
        ImGui.Text("NavId: 0x%08X, NavLayer: %d", g.NavId, g.NavLayer)
        ImGui.Text("NavActive: %d, NavVisible: %d", B(io.NavActive), B(io.NavVisible))
        ImGui.Text("NavActivateId/DownId/PressedId: %08X/%08X/%08X", g.NavActivateId, g.NavActivateDownId or 0, g.NavActivatePressedId or 0)
        ImGui.Text("NavActivateFlags: %04X", g.NavActivateFlags or 0)
        ImGui.Text("NavCursorVisible: %d, NavHighlightItemUnderNav: %d", B(g.NavCursorVisible), B(g.NavHighlightItemUnderNav))
        ImGui.Text("NavFocusScopeId = 0x%08X", g.NavFocusScopeId or 0)
        ImGui.Text("NavWindowingTarget: '%s'", N(g.NavWindowingTarget))
        ImGui.Unindent()
        ImGui.TreePop()
    end

    -- Overlay: Display windows Rectangles and Begin Order
    if cfg.ShowWindowsRects or cfg.ShowWindowsBeginOrder then
        for _, window in g.Windows:iter() do
            if window.WasActive then
                local draw_list = FG(window)
                if cfg.ShowWindowsRects then
                    local r = GetWindowRect(window, cfg.ShowWindowsRectsType)
                    draw_list:AddRect(r.Min, r.Max, IM_COL32(255, 0, 128, 255))
                end
                if cfg.ShowWindowsBeginOrder and bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) == 0 then
                    local font_size = ImGui.GetFontSize()
                    draw_list:AddRectFilled(window.Pos, window.Pos + ImVec2(font_size, font_size), IM_COL32(200, 100, 100, 255))
                    draw_list:AddText(window.Pos, IM_COL32(255, 255, 255, 255), tostring(window.BeginOrderWithinContext))
                end
            end
        end
    end

    -- Overlay: Display Tables Rectangles
    if cfg.ShowTablesRects then
        ForEachTable(g, function(tbl)
            if tbl.LastFrameActive < g.FrameCount - 1 then return end
            local draw_list = FG(tbl.OuterWindow)
            if cfg.ShowTablesRectsType >= TRT_ColumnsRect then
                for column_n = 0, tbl.ColumnsCount - 1 do
                    local r = GetTableRect(tbl, cfg.ShowTablesRectsType, column_n)
                    local hot = (tbl.HoveredColumnBody == column_n)
                    draw_list:AddRect(r.Min, r.Max, hot and IM_COL32(255, 255, 128, 255) or IM_COL32(255, 0, 128, 255), 0.0, hot and 3.0 or 1.0)
                end
            else
                local r = GetTableRect(tbl, cfg.ShowTablesRectsType, -1)
                draw_list:AddRect(r.Min, r.Max, IM_COL32(255, 0, 128, 255))
            end
        end)
    end

    ImGui.End()
    return p_open
end
end --[[ [SECTION] METRICS/DEBUGGER WINDOW, DEBUG LOG, ID STACK TOOL, FONT DEBUG ]]

return true -- [Roblox] ModuleScripts must return exactly one value
end

__FILES['imgui_demo.lua'] = function()
-- dear imgui demo (Luau port of imgui_demo.cpp). Optional: the library never calls into this file.

do --[[ imgui_demo.lua ]]
-- dear imgui, v1.93.0 WIP
-- (demo code) Port of imgui_demo.cpp (docking branch)
-- This file: shared demo helpers, ShowDemoWindow(), DemoWindowMenuBar(), DemoWindowWidgets() dispatcher, example tree/image viewer helpers.
-- Other parts (all global functions, loaded from the same bundle):

-- Help:
-- - Read FAQ at http://dearimgui.com/faq
-- - Call and read ImGui.ShowDemoWindow() in imgui_demo.lua.
-- - Need help integrating Dear ImGui in your codebase?
--   - Read Getting Started https://github.com/ocornut/imgui/wiki/Getting-Started
-- Read top of imgui.cpp and imgui.h for many details, documentation, comments, links.
-- Get the latest version at https://github.com/ocornut/imgui

-- How to easily locate code?
-- - Use Tools->Item Picker to debug break in code by clicking any widgets: https://github.com/ocornut/imgui/wiki/Debug-Tools
-- - Browse pthom's online imgui_explorer: web version the demo w/ source code browser: https://pthom.github.io/imgui_explorer
-- - Find a visible string and search for it in the code!

-----------------------------------------------------
-- PLEASE DO NOT REMOVE THIS FILE FROM YOUR PROJECT!
-----------------------------------------------------
-- Message to the person tempted to delete this file when integrating Dear ImGui into their codebase:
-- Think again! It is the most useful reference code that you and other coders will want to refer to and call.
-- Have the ImGui.ShowDemoWindow() function wired in an always-available debug menu of your game/app!
-- Also include Metrics! ItemPicker! DebugLog! and other debug features.
-- Removing this file from your project is hindering access to documentation for everyone in your team,
-- likely leading you to poorer usage of the library.
-- Whenever you have Dear ImGui available you probably want this to be available for reference.
-- Thank you,
-- -Your beloved friend, imgui_demo.cpp (which you won't delete)

----------------------------------------------
-- ABOUT THE MEANING OF THE 'static' KEYWORD:
----------------------------------------------
-- In the upstream C++ demo code, 'static' variables inside functions are frequently used.
-- A static variable persists across calls. It is essentially a global variable but declared inside the scope of the function.
-- Think of "static int n = 0;" as "global int n = 0;" !
-- (PORT: Lua has no function-local statics; this port keeps them as fields of file-level tables, e.g. `S`, `SL`, `ST`.)
-- We do this IN THE DEMO because we want:
-- - to gather code and data in the same place.
-- - to make the demo source code faster to read, faster to change, smaller in size.
-- - it is also a convenient way of storing simple UI related information as long as your function
--   doesn't need to be reentrant or used in multiple threads.
-- This might be a pattern you will want to use in your code, but most of the data you would be working
-- with in a complex codebase is likely going to be stored outside your functions.

-------------------------------------------
-- ABOUT THE CODING STYLE OF OUR DEMO CODE
-------------------------------------------
-- The Demo code in this file is designed to be easy to copy-and-paste into your application!
-- Because of this:
-- - We never omit the ImGui. prefix when calling functions.

-- Navigating this file:
-- - You can search/grep for all sections listed in the index to find the section.

-- Index of this file:
--
-- [SECTION] Helpers
-- [SECTION] Demo Window / ShowDemoWindow()
-- [SECTION] Helpers: ExampleTreeNode, ExampleMemberInfo (for use by Property Editor & Multi-Select demos)
-- [SECTION] Helpers: ExampleImageViewer
-- [SECTION] DemoWindowWidgetsBasic()
-- [SECTION] DemoWindowWidgetsBullets()
-- [SECTION] DemoWindowWidgetsCollapsingHeaders()
-- [SECTION] DemoWindowWidgetsComboBoxes()
-- [SECTION] DemoWindowWidgetsColorAndPickers()
-- [SECTION] DemoWindowWidgetsDataTypes()
-- [SECTION] DemoWindowWidgetsDisableBlocks()
-- [SECTION] DemoWindowWidgetsDragAndDrop()
-- [SECTION] DemoWindowWidgetsDragsAndSliders()
-- [SECTION] DemoWindowWidgetsFonts()
-- [SECTION] DemoWindowWidgetsImages()
-- [SECTION] DemoWindowWidgetsListBoxes()
-- [SECTION] DemoWindowWidgetsLiveEdit()
-- [SECTION] DemoWindowWidgetsMixedValues()
-- [SECTION] DemoWindowWidgetsMultiComponents()
-- [SECTION] DemoWindowWidgetsPlotting()
-- [SECTION] DemoWindowWidgetsProgressBars()
-- [SECTION] DemoWindowWidgetsQueryingStatuses()
-- [SECTION] DemoWindowWidgetsSelectables()
-- [SECTION] DemoWindowWidgetsTabs()
-- [SECTION] DemoWindowWidgetsText()
-- [SECTION] DemoWindowWidgetsTextFilter()
-- [SECTION] DemoWindowWidgetsTextInput()
-- [SECTION] DemoWindowWidgetsTooltips()
-- [SECTION] DemoWindowWidgetsTreeNodes()
-- [SECTION] DemoWindowWidgetsVerticalSliders()
-- [SECTION] DemoWindowWidgets()
-- [SECTION] DemoWindowLayout()
-- [SECTION] DemoWindowPopups()
-- [SECTION] DemoWindowTables()
-- [SECTION] About Window / ShowAboutWindow()
-- [SECTION] Style Editor / ShowStyleEditor()
-- [SECTION] User Guide / ShowUserGuide()
-- [SECTION] Example App: Main Menu Bar / ShowExampleAppMainMenuBar()
-- [SECTION] Example App: Debug Console / ShowExampleAppConsole()
-- [SECTION] Example App: Debug Log / ShowExampleAppLog()
-- [SECTION] Example App: Simple Layout / ShowExampleAppLayout()
-- [SECTION] Example App: Property Editor / ShowExampleAppPropertyEditor()
-- [SECTION] Example App: Long Text / ShowExampleAppLongText()
-- [SECTION] Example App: Auto Resize / ShowExampleAppAutoResize()
-- [SECTION] Example App: Constrained Resize / ShowExampleAppConstrainedResize()
-- [SECTION] Example App: Simple overlay / ShowExampleAppSimpleOverlay()
-- [SECTION] Example App: Fullscreen window / ShowExampleAppFullscreen()
-- [SECTION] Example App: Manipulating window titles / ShowExampleAppWindowTitles()
-- [SECTION] Example App: Custom Rendering using ImDrawList API / ShowExampleAppCustomRendering()
-- [SECTION] Example App: Docking, DockSpace / ShowExampleAppDockSpace()
-- [SECTION] Example App: Documents Handling / ShowExampleAppDocuments()

local _

-------------------------------------------------------------------------------
-- [SECTION] Helpers
-------------------------------------------------------------------------------

-- Helper to wire demo markers located in code to an interactive browser (e.g. https://pthom.github.io/imgui_explorer)
function IMGUI_DEMO_MARKER(_) end -- upstream hook, no-op here

-- Helper to display a little (?) mark which shows a tooltip when hovered.
-- In your own code you may want to display an actual icon if you are using a merged icon fonts (see docs/FONTS.md)
function HelpMarker(desc)
    ImGui.TextDisabled("(?)")
    if ImGui.BeginItemTooltip() then
        ImGui.PushTextWrapPos(ImGui.GetFontSize() * 35.0)
        ImGui.TextUnformatted(desc)
        ImGui.PopTextWrapPos()
        ImGui.EndTooltip()
    end
end

function ShowDockingDisabledMessage()
    local io = ImGui.GetIO()
    ImGui.Text("ERROR: Docking is not enabled! See Demo > Configuration.")
    ImGui.Text("Set io.ConfigFlags |= ImGuiConfigFlags_DockingEnable in your code, or ")
    ImGui.SameLine(0.0, 0.0)
    if ImGui.SmallButton("click here") then
        io.ConfigFlags = bit32.bor(io.ConfigFlags, ImGuiConfigFlags.DockingEnable)
    end
end

function DemoNotSupported() ImGui.TextDisabled("(not supported on Roblox)") end
function DemoNotPorted(what) ImGui.TextDisabled("(not ported yet%s)", what and (": " .. what) or "") end
function DemoB2I(b) return b and 1 or 0 end
function DemoHas(flags, f) return bit32.band(flags, f) ~= 0 end
function DemoClamp(v, mn, mx) return (v < mn) and mn or (v > mx) and mx or v end

--- `char buf[size] = "str"` -> zero-terminated byte table
function DemoBuf(str, size)
    local t = {}
    for i = 1, #str do t[i] = string.byte(str, i) end
    t[#str + 1] = 0
    if size then for i = #str + 2, size do t[i] = 0 end end
    return t
end
--- byte table -> Lua string (up to the zero terminator)
function DemoBufStr(buf)
    local n = 0
    while buf[n + 1] ~= nil and buf[n + 1] ~= 0 do n = n + 1 end
    if n == 0 then return "" end
    return ImGui._ByteArrayToString(buf, 1, n + 1)
end

--- "a\0b\0c\0\0" -> { "a", "b", "c" }
function DemoItems(s)
    if type(s) == "table" then return s end
    local t = {}
    for item in string.gmatch(s, "([^%z]+)") do t[#t + 1] = item end
    return t
end

--- Combo() one-liner. `idx` is 0-based; `items` is a table of strings (1-based) or a "\0"-separated string.
--- Uses ImGui.Combo if it exists, falls back to BeginCombo/Selectable.
--- @return int idx, bool changed
function DemoCombo(label, idx, items, popup_max_height_in_items)
    items = DemoItems(items)
    if ImGui.Combo then
        return ImGui.Combo(label, idx, items, #items, popup_max_height_in_items or -1)
    end
    local changed = false
    local preview = (idx >= 0 and idx < #items) and items[idx + 1] or ""
    if ImGui.BeginCombo(label, preview) then
        for n = 0, #items - 1 do
            local is_selected = (idx == n)
            if ImGui.Selectable(items[n + 1], is_selected) then
                idx = n
                changed = true
            end
            if is_selected then ImGui.SetItemDefaultFocus() end
        end
        ImGui.EndCombo()
    end
    return idx, changed
end

--- ListBox() one-liner (see DemoCombo)
function DemoListBox(label, idx, items, height_in_items)
    items = DemoItems(items)
    if ImGui.ListBox then
        return ImGui.ListBox(label, idx, items, #items, height_in_items or -1)
    end
    local changed = false
    if height_in_items == nil or height_in_items < 0 then height_in_items = math.min(#items, 7) end
    local height_in_items_f = height_in_items + 0.25
    local height_in_pixels = math.floor(ImGui.GetTextLineHeightWithSpacing() * height_in_items_f + ImGui.GetStyle().FramePadding.y * 2.0)
    if ImGui.BeginListBox and ImGui.BeginListBox(label, ImVec2(0.0, height_in_pixels)) then
        for n = 0, #items - 1 do
            local is_selected = (idx == n)
            if ImGui.Selectable(items[n + 1], is_selected) then
                idx = n
                changed = true
            end
            if is_selected then ImGui.SetItemDefaultFocus() end
        end
        ImGui.EndListBox()
    elseif not ImGui.BeginListBox then
        DemoNotPorted("ListBox")
    end
    return idx, changed
end

--- Closable header: CollapsingHeader(label, &p_open). Returns visible, open.
function DemoCollapsingHeaderClosable(label, open)
    return ImGui.CollapsingHeader(label, open)
end

--- ImColor::HSV() as ImVec4
function DemoHSV(h, s, v, a)
    local r, g, b = ImGui.ColorConvertHSVtoRGB(h, s, v)
    return ImVec4(r, g, b, a or 1.0)
end

--- Minimal ImGuiTextFilter when the library one isn't available (Draw/DrawWithHint/PassFilter/Clear/IsActive)
function DemoTextFilter()
    if ImGuiTextFilter then return ImGuiTextFilter() end
    local f = { InputBuf = DemoBuf("", 256) }
    local function parse(self)
        local inc, exc = {}, {}
        for tok in string.gmatch(string.lower(DemoBufStr(self.InputBuf)), "[^,%s]+") do
            if string.sub(tok, 1, 1) == "-" then
                if #tok > 1 then exc[#exc + 1] = string.sub(tok, 2) end
            else
                inc[#inc + 1] = tok
            end
        end
        return inc, exc
    end
    function f:Draw(label, width)
        if width and width ~= 0 then ImGui.SetNextItemWidth(width) end
        return ImGui.InputText(label or "Filter (inc,-exc)", self.InputBuf, 256)
    end
    function f:DrawWithHint(label, hint, width)
        if width and width ~= 0 then ImGui.SetNextItemWidth(width) end
        return ImGui.InputTextWithHint(label, hint, self.InputBuf, 256)
    end
    function f:Clear() self.InputBuf[1] = 0 end
    function f:IsActive() return self.InputBuf[1] ~= 0 and self.InputBuf[1] ~= nil end
    function f:PassFilter(text)
        local inc, exc = parse(self)
        text = string.lower(text)
        for _, e in ipairs(exc) do if string.find(text, e, 1, true) then return false end end
        if #inc == 0 then return true end
        for _, i in ipairs(inc) do if string.find(text, i, 1, true) then return true end end
        return false
    end
    return f
end

-------------------------------------------------------------------------------
-- [SECTION] Demo Window data
-------------------------------------------------------------------------------

--- Data to be shared across different functions of the demo.
function ImGuiDemoWindowData()
    return {
        -- Examples Apps (accessible from the "Examples" menu)
        ShowMainMenuBar = false,
        ShowAppAssetsBrowser = false,
        ShowAppConsole = false,
        ShowAppCustomRendering = false,
        ShowAppDocuments = false,
        ShowAppDockSpace = false,
        ShowAppImageViewer = false,
        ShowAppLog = false,
        ShowAppLayout = false,
        ShowAppPropertyEditor = false,
        ShowAppSimpleOverlay = false,
        ShowAppAutoResize = false,
        ShowAppConstrainedResize = false,
        ShowAppFullscreen = false,
        ShowAppLongText = false,
        ShowAppWindowTitles = false,

        -- Dear ImGui Tools (accessible from the "Tools" menu)
        ShowMetrics = false,
        ShowDebugLog = false,
        ShowIDStackTool = false,
        ShowStyleEditor = false,
        ShowAbout = false,

        -- Other data
        DisableSections = false,
        LiveEditOverride = false,
        LiveEditFlags = ImGuiItemFlags.LiveEditOnInputText or 0,
        DemoTree = nil,
    }
end

-------------------------------------------------------------------------------
-- [SECTION] Helpers: ExampleTreeNode, ExampleMemberInfo (for use by Property Editor & Multi-Select demos)
-------------------------------------------------------------------------------

-- Simple representation for a tree
-- (this is designed to be simple to understand for our demos, not to be fancy or efficient etc.)
function ExampleTreeNode()
    return {
        -- Tree structure
        Name = "",
        UID = 0,
        Parent = nil,
        Childs = {},         -- 1-based
        IndexInParent = 0,   -- 0-based. Maintaining this allows us to implement linear traversal more easily

        -- Leaf Data
        HasData = false,     -- All leaves have data
        DataMyBool = true,
        DataMyInt = 128,
        DataMyVec2 = ImVec2(0.0, 3.141592),
    }
end

function ExampleTree_CreateNode(name, uid, parent)
    local node = ExampleTreeNode()
    node.Name = string.sub(name, 1, 27)
    node.UID = uid
    node.Parent = parent
    node.IndexInParent = parent and #parent.Childs or 0
    if parent then
        parent.Childs[#parent.Childs + 1] = node
    end
    return node
end

function ExampleTree_DestroyNode(node) end -- GC

-- Create example tree data
-- (warning: this can allocates MANY MANY more times than other code in all of Dear ImGui + demo combined)
-- (a real application managing one million nodes would likely store its tree data differently)
function ExampleTree_CreateDemoTree()
    --     20 root nodes ->    211 total nodes,   ~261 allocs.
    --   1000 root nodes ->   ~11K total nodes,   ~14K allocs.
    --  10000 root nodes ->  ~123K total nodes,  ~154K allocs.
    -- 100000 root nodes -> ~1338K total nodes, ~1666K allocs.
    local ROOT_ITEMS_COUNT = 20
    local category_names = { "Apple", "Banana", "Cherry", "Kiwi", "Mango", "Orange", "Pear", "Pineapple", "Strawberry", "Watermelon" }
    local category_count = #category_names
    local uid = 0
    uid = uid + 1
    local node_L0 = ExampleTree_CreateNode("<ROOT>", uid, nil)
    for idx_L0 = 0, ROOT_ITEMS_COUNT - 1 do
        local name_buf = string.format("%s %d", category_names[math.floor(idx_L0 / math.floor(ROOT_ITEMS_COUNT / category_count)) + 1], idx_L0 % math.floor(ROOT_ITEMS_COUNT / category_count))
        uid = uid + 1
        local node_L1 = ExampleTree_CreateNode(name_buf, uid, node_L0)
        local number_of_childs = #node_L1.Name
        for idx_L1 = 0, number_of_childs - 1 do
            uid = uid + 1
            local node_L2 = ExampleTree_CreateNode(string.format("Child %d", idx_L1), uid, node_L1)
            node_L2.HasData = true
            if idx_L1 == 0 then
                uid = uid + 1
                local node_L3 = ExampleTree_CreateNode(string.format("Sub-child %d", 0), uid, node_L2)
                node_L3.HasData = true
            end
        end
    end
    return node_L0
end

-------------------------------------------------------------------------------
-- [SECTION] Helpers: ExampleImageViewer
-------------------------------------------------------------------------------

function ExampleImageViewerData()
    return {
        ImageBgColor = IM_COL32(100, 100, 100, 255),
        GridColor    = IM_COL32(255, 255, 255, 100),
        GridEnabled  = true,
        ViewReset    = true,
        ViewOffset   = ImVec2(0, 0), -- in image space
        Zoom         = 10.0,
        ZoomMin      = 1.0,
        ZoomMax      = 10000.0,
    }
end

function ExampleImageViewer_DrawOptions(data)
    ImGui.SetNextItemShortcut(ImGuiKey.G, ImGuiInputFlags.Tooltip) -- | ImGuiInputFlags.RouteGlobal
    _, data.GridEnabled = ImGui.Checkbox("Grid", data.GridEnabled)
    ImGui.SameLine()
    ImGui.SetNextItemWidth(ImGui.GetFontSize() * 10.0)
    local zoom_100 = data.Zoom * 100.0
    local changed
    zoom_100, changed = ImGui.DragFloat("##Zoom", zoom_100, 5.0, data.ZoomMin * 100.0, data.ZoomMax * 100.0, "%.0f%%", ImGuiSliderFlags.AlwaysClamp)
    if changed then
        data.Zoom = zoom_100 / 100.0
    end
end

function ExampleImageViewer_DrawCanvas(data, canvas_size, image_tex_ref, image_w, image_h)
    local io = ImGui.GetIO()
    local platform_io = ImGui.GetPlatformIO()
    local draw_list = ImGui.GetWindowDrawList()
    IM_ASSERT(canvas_size.x >= 0.0 and canvas_size.y >= 0.0)

    -- Layout canvas
    ImGui.InvisibleButton("##Canvas", canvas_size)
    local canvas_min = ImGui.GetItemRectMin()
    local canvas_max = ImGui.GetItemRectMax()

    if data.ViewReset then
        data.ViewOffset = ImVec2((canvas_size.x * 0.5 / data.Zoom) - 0.5, (canvas_size.y * 0.5 / data.Zoom) - 0.5) -- Add half a pixel padding
    end
    data.ViewReset = false

    -- Handle inputs
    if ImGui.SetItemKeyOwner(ImGuiKey.MouseWheelY) then
        if io.MouseWheel ~= 0.0 then
            data.Zoom = DemoClamp(data.Zoom * (1.0 + io.MouseWheel * 0.10), data.ZoomMin, data.ZoomMax)
        end
    end
    local zoom = data.Zoom -- (float)(int)ViewZoom;
    if ImGui.IsItemActive() and ImGui.IsMouseDragging(0) then
        data.ViewOffset.x = data.ViewOffset.x - io.MouseDelta.x / zoom
        data.ViewOffset.y = data.ViewOffset.y - io.MouseDelta.y / zoom
    end

    -- Display image
    local image_min = ImVec2(); local image_max = ImVec2()
    image_min.x = math.floor((canvas_min.x - (data.ViewOffset.x * zoom)) + (canvas_size.x * 0.5))
    image_min.y = math.floor((canvas_min.y - (data.ViewOffset.y * zoom)) + (canvas_size.y * 0.5))
    image_max.x = math.floor(image_min.x + image_w * zoom)
    image_max.y = math.floor(image_min.y + image_h * zoom)
    draw_list:AddRect(ImVec2(canvas_min.x - 1.0, canvas_min.y - 1.0), ImVec2(canvas_max.x + 1.0, canvas_max.y + 1.0), IM_COL32(255, 255, 255, 255))
    draw_list:PushClipRect(canvas_min, canvas_max, true)
    draw_list:AddRectFilled(image_min, image_max, data.ImageBgColor)
    if platform_io.DrawCallback_SetSamplerNearest ~= nil then
        draw_list:AddCallback(platform_io.DrawCallback_SetSamplerNearest)
    end
    draw_list:AddImage(image_tex_ref, image_min, image_max)
    if platform_io.DrawCallback_SetSamplerLinear ~= nil then
        draw_list:AddCallback(ImGui.GetPlatformIO().DrawCallback_SetSamplerLinear)
    end

    -- Display grid lines for visible pixels
    if data.GridEnabled and zoom > 6.0 then
        local step = zoom
        for px = math.floor((canvas_min.x - image_min.x) / step), math.floor((canvas_max.x - image_min.x) / step) do
            draw_list:AddLineV(image_min.x + px * step, canvas_min.y, canvas_max.y, data.GridColor, 1.0)
        end
        for py = math.floor((canvas_min.y - image_min.y) / step), math.floor((canvas_max.y - image_min.y) / step) do
            draw_list:AddLineH(canvas_min.x, canvas_max.x, image_min.y + py * step, data.GridColor, 1.0)
        end
    end
    draw_list:PopClipRect()
end

-------------------------------------------------------------------------------
-- [SECTION] Demo Window / ShowDemoWindow()
-------------------------------------------------------------------------------

-- Stored data
local demo_data = ImGuiDemoWindowData()

local no_titlebar       = false
local no_scrollbar      = false
local no_menu           = false
local no_move           = false
local no_resize         = false
local no_collapse       = false
local no_close          = false
local no_nav            = false
local no_background     = false
local no_bring_to_front = false
local no_docking        = false
local unsaved_document  = false

--- Shows an example app: `if X then X.open = X(open) end`. Example apps return the new p_open.
local function RunApp(fn, key, ...)
    if fn then
        demo_data[key] = fn(demo_data[key], ...)
        if demo_data[key] == nil then demo_data[key] = false end
    else
        demo_data[key] = false
    end
end

local function DemoWindowMenuBar(data)
    if ImGui.BeginMenuBar() then
        if ImGui.BeginMenu("Menu") then
            IMGUI_DEMO_MARKER("Menu/File")
            ShowExampleMenuFile()
            ImGui.EndMenu()
        end
        if ImGui.BeginMenu("Examples") then
            IMGUI_DEMO_MARKER("Menu/Examples")
            _, data.ShowMainMenuBar = ImGui.MenuItem("Main menu bar", nil, data.ShowMainMenuBar)

            ImGui.SeparatorText("Mini apps")
            _, data.ShowAppAssetsBrowser = ImGui.MenuItem("Assets Browser", nil, data.ShowAppAssetsBrowser)
            _, data.ShowAppConsole = ImGui.MenuItem("Console", nil, data.ShowAppConsole)
            _, data.ShowAppCustomRendering = ImGui.MenuItem("Custom rendering", nil, data.ShowAppCustomRendering)
            _, data.ShowAppDocuments = ImGui.MenuItem("Documents", nil, data.ShowAppDocuments)
            _, data.ShowAppDockSpace = ImGui.MenuItem("Dockspace", nil, data.ShowAppDockSpace)
            _, data.ShowAppImageViewer = ImGui.MenuItem("Image Viewer", nil, data.ShowAppImageViewer)
            _, data.ShowAppLog = ImGui.MenuItem("Log", nil, data.ShowAppLog)
            _, data.ShowAppPropertyEditor = ImGui.MenuItem("Property editor", nil, data.ShowAppPropertyEditor)
            _, data.ShowAppLayout = ImGui.MenuItem("Simple layout", nil, data.ShowAppLayout)
            _, data.ShowAppSimpleOverlay = ImGui.MenuItem("Simple overlay", nil, data.ShowAppSimpleOverlay)

            ImGui.SeparatorText("Concepts")
            _, data.ShowAppAutoResize = ImGui.MenuItem("Auto-resizing window", nil, data.ShowAppAutoResize)
            _, data.ShowAppConstrainedResize = ImGui.MenuItem("Constrained-resizing window", nil, data.ShowAppConstrainedResize)
            _, data.ShowAppFullscreen = ImGui.MenuItem("Fullscreen window", nil, data.ShowAppFullscreen)
            _, data.ShowAppLongText = ImGui.MenuItem("Long text display", nil, data.ShowAppLongText)
            _, data.ShowAppWindowTitles = ImGui.MenuItem("Manipulating window titles", nil, data.ShowAppWindowTitles)

            ImGui.EndMenu()
        end
        -- if ImGui.MenuItem("MenuItem") then end -- You can also use MenuItem() inside a menu bar!
        if ImGui.BeginMenu("Tools") then
            IMGUI_DEMO_MARKER("Menu/Tools")
            local io = ImGui.GetIO()
            local has_debug_tools = not IMGUI_DISABLE_DEBUG_TOOLS
            _, data.ShowMetrics = ImGui.MenuItem("Metrics/Debugger", nil, data.ShowMetrics, has_debug_tools and ImGui.ShowMetricsWindow ~= nil)
            if ImGui.BeginMenu("Debug Options") then
                ImGui.BeginDisabled(not has_debug_tools)
                _, io.ConfigDebugHighlightIdConflicts = ImGui.Checkbox("Highlight ID Conflicts", io.ConfigDebugHighlightIdConflicts)
                ImGui.EndDisabled()
                _, io.ConfigErrorRecoveryEnableAssert = ImGui.Checkbox("Assert on error recovery", io.ConfigErrorRecoveryEnableAssert)
                ImGui.TextDisabled("(see Demo->Configuration for more)")
                ImGui.EndMenu()
            end
            _, data.ShowDebugLog = ImGui.MenuItem("Debug Log", nil, data.ShowDebugLog, has_debug_tools and ImGui.ShowDebugLogWindow ~= nil)
            _, data.ShowIDStackTool = ImGui.MenuItem("ID Stack Tool", nil, data.ShowIDStackTool, has_debug_tools and ImGui.ShowIDStackToolWindow ~= nil)
            local is_debugger_present = io.ConfigDebugIsDebuggerPresent
            if ImGui.MenuItem("Item Picker", nil, false, has_debug_tools and ImGui.DebugStartItemPicker ~= nil) then -- and is_debugger_present
                ImGui.DebugStartItemPicker()
            end
            if not is_debugger_present then
                ImGui.SetItemTooltip("Requires io.ConfigDebugIsDebuggerPresent=true to be set.\n\nWe otherwise disable some extra features to avoid casual users crashing the application.")
            end
            _, data.ShowStyleEditor = ImGui.MenuItem("Style Editor", nil, data.ShowStyleEditor)
            _, data.ShowAbout = ImGui.MenuItem("About Dear ImGui", nil, data.ShowAbout)

            ImGui.EndMenu()
        end
        ImGui.EndMenuBar()
    end
end

--- Configuration header contents (split from ShowDemoWindow to keep the function small)
local function DemoWindowConfiguration(io)
    local F = ImGuiConfigFlags
    local function CF(label, flag)
        local pressed
        pressed, io.ConfigFlags = ImGui.CheckboxFlags(label, io.ConfigFlags, flag)
        return pressed
    end
    local function CB(label, field)
        local pressed
        pressed, io[field] = ImGui.Checkbox(label, io[field])
        return pressed
    end
    local function HM(desc) ImGui.SameLine(); HelpMarker(desc) end

    if ImGui.TreeNode("Configuration##2") then
        IMGUI_DEMO_MARKER("Configuration")
        ImGui.SeparatorText("General")
        CF("io.ConfigFlags: NavEnableKeyboard", F.NavEnableKeyboard)
        HM("Enable keyboard controls.")
        CF("io.ConfigFlags: NavEnableGamepad", F.NavEnableGamepad)
        HM("Enable gamepad controls. Require backend to set io.BackendFlags |= ImGuiBackendFlags_HasGamepad.\n\nRead instructions in imgui.cpp for details.")
        CF("io.ConfigFlags: NoMouse", F.NoMouse)
        HM("Instruct dear imgui to disable mouse inputs and interactions.")

        -- The "NoMouse" option can get us stuck with a disabled mouse! Let's provide an alternative way to fix it:
        if DemoHas(io.ConfigFlags, F.NoMouse) then
            if (ImGui.GetTime() % 0.40) < 0.20 then
                ImGui.SameLine()
                ImGui.Text("<<PRESS SPACE TO DISABLE>>")
            end
            -- Prevent both being checked
            if ImGui.IsKeyPressed(ImGuiKey.Space) or DemoHas(io.ConfigFlags, F.NoKeyboard) then
                io.ConfigFlags = bit32.band(io.ConfigFlags, bit32.bnot(F.NoMouse))
            end
        end

        CF("io.ConfigFlags: NoMouseCursorChange", F.NoMouseCursorChange)
        HM("Instruct backend to not alter mouse cursor shape and visibility.")
        CF("io.ConfigFlags: NoKeyboard", F.NoKeyboard)
        HM("Instruct dear imgui to disable keyboard inputs and interactions.")

        CB("io.ConfigInputTrickleEventQueue", "ConfigInputTrickleEventQueue")
        HM("Enable input queue trickling: some types of events submitted during the same frame (e.g. button down + up) will be spread over multiple frames, improving interactions with low framerates.")
        CB("io.MouseDrawCursor", "MouseDrawCursor")
        HM("Instruct Dear ImGui to render a mouse cursor itself. Note that a mouse cursor rendered via your application GPU rendering path will feel more laggy than hardware cursor, but will be more in sync with your other visuals.\n\nSome desktop applications may use both kinds of cursors (e.g. enable software cursor only when resizing/dragging something).")

        ImGui.SeparatorText("Keyboard/Gamepad Navigation")
        CB("io.ConfigNavSwapGamepadButtons", "ConfigNavSwapGamepadButtons")
        CB("io.ConfigNavMoveSetMousePos", "ConfigNavMoveSetMousePos")
        HM("Directional/tabbing navigation teleports the mouse cursor. May be useful on TV/console systems where moving a virtual mouse is difficult")
        CB("io.ConfigNavCaptureKeyboard", "ConfigNavCaptureKeyboard")
        CB("io.ConfigNavEscapeClearFocusItem", "ConfigNavEscapeClearFocusItem")
        HM("Pressing Escape clears focused item.")
        CB("io.ConfigNavEscapeClearFocusWindow", "ConfigNavEscapeClearFocusWindow")
        HM("Pressing Escape clears focused window.")
        CB("io.ConfigNavCursorVisibleAuto", "ConfigNavCursorVisibleAuto")
        HM("Using directional navigation key makes the cursor visible. Mouse click hides the cursor.")
        CB("io.ConfigNavCursorVisibleAlways", "ConfigNavCursorVisibleAlways")
        HM("Navigation cursor is always visible.")

        ImGui.SeparatorText("Docking")
        CF("io.ConfigFlags: DockingEnable", F.DockingEnable)
        ImGui.SameLine()
        if io.ConfigDockingWithShift then
            HelpMarker("Drag from window title bar or their tab to dock/undock. Hold SHIFT to enable docking.\n\nDrag from window menu button (upper-left button) to undock an entire node (all windows).")
        else
            HelpMarker("Drag from window title bar or their tab to dock/undock. Hold SHIFT to disable docking.\n\nDrag from window menu button (upper-left button) to undock an entire node (all windows).")
        end
        if DemoHas(io.ConfigFlags, F.DockingEnable) then
            ImGui.Indent()
            CB("io.ConfigDockingNoSplit", "ConfigDockingNoSplit")
            HM("Simplified docking mode: disable window splitting, so docking is limited to merging multiple windows together into tab-bars.")
            CB("io.ConfigDockingNoDockingOver", "ConfigDockingNoDockingOver")
            HM("Simplified docking mode: disable window merging into a same tab-bar, so docking is limited to splitting windows.")
            CB("io.ConfigDockingWithShift", "ConfigDockingWithShift")
            HM("Enable docking when holding Shift only (allow to drop in wider space, reduce visual noise)")
            CB("io.ConfigDockingAlwaysTabBar", "ConfigDockingAlwaysTabBar")
            HM("Create a docking node and tab-bar on single floating windows.")
            CB("io.ConfigDockingTransparentPayload", "ConfigDockingTransparentPayload")
            HM("Make window or viewport transparent when docking and only display docking boxes on the target viewport. Useful if rendering of multiple viewport cannot be synced. Best used with ConfigViewportsNoAutoMerge.")
            ImGui.Unindent()
        end

        ImGui.SeparatorText("Multi-viewports")
        CF("io.ConfigFlags: ViewportsEnable", F.ViewportsEnable)
        HM("[beta] Enable beta multi-viewports support. See ImGuiPlatformIO for details.")
        if DemoHas(io.ConfigFlags, F.ViewportsEnable) then
            ImGui.Indent()
            DemoNotSupported()
            ImGui.Unindent()
        end

        -- ImGui.SeparatorText("DPI/Scaling")
        -- CB("io.ConfigDpiScaleFonts", "ConfigDpiScaleFonts")
        -- HM("Experimental: Automatically update style.FontScaleDpi when Monitor DPI changes. This will scale fonts but NOT style sizes/padding for now.")
        -- CB("io.ConfigDpiScaleViewports", "ConfigDpiScaleViewports")
        -- HM("Experimental: Scale Dear ImGui and Platform Windows when Monitor DPI changes.")

        ImGui.SeparatorText("Windows")
        CB("io.ConfigWindowsResizeFromEdges", "ConfigWindowsResizeFromEdges")
        HM("Enable resizing of windows from their edges and from the lower-left corner.\nThis requires ImGuiBackendFlags_HasMouseCursors for better mouse cursor feedback.")
        CB("io.ConfigWindowsMoveFromTitleBarOnly", "ConfigWindowsMoveFromTitleBarOnly")
        CB("io.ConfigWindowsCopyContentsWithCtrlC", "ConfigWindowsCopyContentsWithCtrlC") -- [EXPERIMENTAL]
        HM("*EXPERIMENTAL* Ctrl+C copy the contents of focused window into the clipboard.\n\nExperimental because:\n- (1) has known issues with nested Begin/End pairs.\n- (2) text output quality varies.\n- (3) text output is in submission order rather than spatial order.")
        CB("io.ConfigScrollbarScrollByPage", "ConfigScrollbarScrollByPage")
        HM("Enable scrolling page by page when clicking outside the scrollbar grab.\nWhen disabled, always scroll to clicked location.\nWhen enabled, Shift+Click scrolls to clicked location.")

        ImGui.SeparatorText("Widgets")
        CB("io.ConfigInputTextCursorBlink", "ConfigInputTextCursorBlink")
        HM("Enable blinking cursor (optional as some users consider it to be distracting).")
        CB("io.ConfigInputTextEnterKeepActive", "ConfigInputTextEnterKeepActive")
        HM("Pressing Enter will reactivate item and select all text (single-line only).")
        CB("io.ConfigDragClickToInputText", "ConfigDragClickToInputText")
        HM("Enable turning DragXXX widgets into text input with a simple mouse click-release (without moving).")
        CB("io.ConfigMacOSXBehaviors", "ConfigMacOSXBehaviors")
        HM("Swap Cmd<>Ctrl keys, enable various MacOS style behaviors.")
        ImGui.Text("Also see Style->Rendering for rendering options.")

        ImGui.SeparatorText("Settings")
        CB("io.ConfigIniSettingsSaveLastUsedDate", "ConfigIniSettingsSaveLastUsedDate")

        -- Also read: https://github.com/ocornut/imgui/wiki/Error-Handling
        ImGui.SeparatorText("Error Handling")

        CB("io.ConfigErrorRecovery", "ConfigErrorRecovery")
        HM(
            "Options to configure how we handle recoverable errors.\n" ..
            "- Error recovery is not perfect nor guaranteed! It is a feature to ease development.\n" ..
            "- You not are not supposed to rely on it in the course of a normal application run.\n" ..
            "- Possible usage: facilitate recovery from errors triggered from a scripting language or after specific exceptions handlers.\n" ..
            "- Always ensure that on programmers seat you have at minimum Asserts or Tooltips enabled when making direct imgui API call! " ..
            "Otherwise it would severely hinder your ability to catch and correct mistakes!")
        CB("io.ConfigErrorRecoveryEnableAssert", "ConfigErrorRecoveryEnableAssert")
        CB("io.ConfigErrorRecoveryEnableDebugLog", "ConfigErrorRecoveryEnableDebugLog")
        CB("io.ConfigErrorRecoveryEnableTooltip", "ConfigErrorRecoveryEnableTooltip")
        if not io.ConfigErrorRecoveryEnableAssert and not io.ConfigErrorRecoveryEnableDebugLog and not io.ConfigErrorRecoveryEnableTooltip then
            io.ConfigErrorRecoveryEnableAssert = true
            io.ConfigErrorRecoveryEnableDebugLog = true
            io.ConfigErrorRecoveryEnableTooltip = true
        end

        -- Also read: https://github.com/ocornut/imgui/wiki/Debug-Tools
        ImGui.SeparatorText("Debug")
        CB("io.ConfigDebugIsDebuggerPresent", "ConfigDebugIsDebuggerPresent")
        HM("Enable various tools calling IM_DEBUG_BREAK().\n\nRequires a debugger being attached, otherwise IM_DEBUG_BREAK() options will appear to crash your application.")
        CB("io.ConfigDebugHighlightIdConflicts", "ConfigDebugHighlightIdConflicts")
        HM("Highlight and show an error message when multiple items have conflicting identifiers.")
        ImGui.BeginDisabled()
        CB("io.ConfigDebugBeginReturnValueOnce", "ConfigDebugBeginReturnValueOnce")
        ImGui.EndDisabled()
        HM("First calls to Begin()/BeginChild() will return false.\n\nTHIS OPTION IS DISABLED because it needs to be set at application boot-time to make sense. Showing the disabled option is a way to make this feature easier to discover.")
        CB("io.ConfigDebugBeginReturnValueLoop", "ConfigDebugBeginReturnValueLoop")
        HM("Some calls to Begin()/BeginChild() will return false.\n\nWill cycle through window depths then repeat. Windows should be flickering while running.")
        CB("io.ConfigDebugIgnoreFocusLoss", "ConfigDebugIgnoreFocusLoss")
        HM("Option to deactivate io.AddFocusEvent(false) handling. May facilitate interactions with a debugger when focus loss leads to clearing inputs data.")
        CB("io.ConfigDebugDrawListDefaultsToStrokeLegacy", "ConfigDebugDrawListDefaultsToStrokeLegacy")
        HM("Option to default all ImDrawList to ImDrawFlags_StrokeLegacy mode, mimicking pre-1.93.0 rendering.")
        CB("io.ConfigDebugIniSettings", "ConfigDebugIniSettings")
        HM("Option to save .ini data with extra comments (particularly helpful for Docking, but makes saving slower).")

        ImGui.TreePop()
        ImGui.Spacing()
    end

    if ImGui.TreeNode("Backend Flags") then
        IMGUI_DEMO_MARKER("Configuration/Backend Flags")
        HelpMarker(
            "Those flags are set by the backends (imgui_impl_xxx files) to specify their capabilities.\n" ..
            "Here we expose them as read-only fields to avoid breaking interactions with your backend.")

        -- Make a local copy to avoid modifying actual backend flags.
        -- FIXME: Maybe we need a BeginReadonly() equivalent to keep label bright?
        local B = ImGuiBackendFlags
        local backend_flags = io.BackendFlags
        ImGui.BeginDisabled()
        _, backend_flags = ImGui.CheckboxFlags("io.BackendFlags: HasGamepad", backend_flags, B.HasGamepad)
        _, backend_flags = ImGui.CheckboxFlags("io.BackendFlags: HasMouseCursors", backend_flags, B.HasMouseCursors)
        _, backend_flags = ImGui.CheckboxFlags("io.BackendFlags: HasSetMousePos", backend_flags, B.HasSetMousePos)
        _, backend_flags = ImGui.CheckboxFlags("io.BackendFlags: PlatformHasViewports", backend_flags, B.PlatformHasViewports)
        _, backend_flags = ImGui.CheckboxFlags("io.BackendFlags: HasMouseHoveredViewport", backend_flags, B.HasMouseHoveredViewport)
        _, backend_flags = ImGui.CheckboxFlags("io.BackendFlags: HasParentViewport", backend_flags, B.HasParentViewport)
        _, backend_flags = ImGui.CheckboxFlags("io.BackendFlags: RendererHasVtxOffset", backend_flags, B.RendererHasVtxOffset)
        _, backend_flags = ImGui.CheckboxFlags("io.BackendFlags: RendererHasTextures", backend_flags, B.RendererHasTextures)
        _, backend_flags = ImGui.CheckboxFlags("io.BackendFlags: RendererHasViewports", backend_flags, B.RendererHasViewports)
        ImGui.EndDisabled()

        ImGui.TreePop()
        ImGui.Spacing()
    end

    if ImGui.TreeNode("Style, Fonts") then
        IMGUI_DEMO_MARKER("Configuration/Style, Fonts")
        _, demo_data.ShowStyleEditor = ImGui.Checkbox("Style Editor", demo_data.ShowStyleEditor)
        ImGui.SameLine()
        HelpMarker("The same contents can be accessed in 'Tools->Style Editor' or by calling the ShowStyleEditor() function.")
        ImGui.TreePop()
        ImGui.Spacing()
    end

    if ImGui.TreeNode("Capture/Logging") then
        IMGUI_DEMO_MARKER("Configuration/Capture, Logging")
        HelpMarker(
            "The logging API redirects all text output so you can easily capture the content of " ..
            "a window or a block. Tree nodes can be automatically expanded.\n" ..
            "Try opening any of the contents below in this window and then click one of the \"Log To\" button.")
        if ImGui.LogButtons then
            ImGui.LogButtons()
        else
            DemoNotPorted("LogButtons")
        end

        HelpMarker("You can also call ImGui::LogText() to output directly to the log without a visual output.")
        if ImGui.Button("Copy \"Hello, world!\" to clipboard") then
            if ImGui.LogToClipboard then
                ImGui.LogToClipboard()
                ImGui.LogText("Hello, world!")
                ImGui.LogFinish()
            else
                ImGui.SetClipboardText("Hello, world!") -- internal clipboard only on Roblox
            end
        end
        ImGui.TreePop()
    end
end

-- Demonstrate most Dear ImGui features (this is big function!)
-- You may execute this function to experiment with the UI and understand what it does.
-- You may then search for keywords in the code when you are interested by a specific feature.
--- @param p_open? bool
--- @return bool? p_open
function ImGui.ShowDemoWindow(p_open)
    -- Exceptionally add an extra assert here for people confused about initial Dear ImGui setup
    -- Most functions would normally just assert/crash if the context is missing.
    IM_ASSERT(ImGui.GetCurrentContext() ~= nil, "Missing Dear ImGui context. Refer to examples app!")

    local data = demo_data

    -- Examples Apps (accessible from the "Examples" menu)
    if data.ShowMainMenuBar then
        if ShowExampleAppMainMenuBar then ShowExampleAppMainMenuBar() end
    end
    if data.ShowAppDockSpace then RunApp(ShowExampleAppDockSpace, "ShowAppDockSpace") end -- Important: Process the Docking app first, as explicit DockSpace() nodes needs to be submitted early (read comments near the DockSpace function)
    if data.ShowAppDocuments then RunApp(ShowExampleAppDocuments, "ShowAppDocuments") end -- ...process the Document app next, as it may also use a DockSpace()
    if data.ShowAppAssetsBrowser then RunApp(ShowExampleAppAssetsBrowser, "ShowAppAssetsBrowser") end
    if data.ShowAppConsole then RunApp(ShowExampleAppConsole, "ShowAppConsole") end
    if data.ShowAppCustomRendering then RunApp(ShowExampleAppCustomRendering, "ShowAppCustomRendering") end
    if data.ShowAppImageViewer then RunApp(ShowExampleAppImageViewer, "ShowAppImageViewer") end
    if data.ShowAppLog then RunApp(ShowExampleAppLog, "ShowAppLog") end
    if data.ShowAppLayout then RunApp(ShowExampleAppLayout, "ShowAppLayout") end
    if data.ShowAppPropertyEditor then RunApp(ShowExampleAppPropertyEditor, "ShowAppPropertyEditor", data) end
    if data.ShowAppSimpleOverlay then RunApp(ShowExampleAppSimpleOverlay, "ShowAppSimpleOverlay") end
    if data.ShowAppAutoResize then RunApp(ShowExampleAppAutoResize, "ShowAppAutoResize") end
    if data.ShowAppConstrainedResize then RunApp(ShowExampleAppConstrainedResize, "ShowAppConstrainedResize") end
    if data.ShowAppFullscreen then RunApp(ShowExampleAppFullscreen, "ShowAppFullscreen") end
    if data.ShowAppLongText then RunApp(ShowExampleAppLongText, "ShowAppLongText") end
    if data.ShowAppWindowTitles then RunApp(ShowExampleAppWindowTitles, "ShowAppWindowTitles") end

    -- Dear ImGui Tools (accessible from the "Tools" menu)
    if data.ShowMetrics then RunApp(ImGui.ShowMetricsWindow, "ShowMetrics") end
    if data.ShowDebugLog then RunApp(ImGui.ShowDebugLogWindow, "ShowDebugLog") end
    if data.ShowIDStackTool then RunApp(ImGui.ShowIDStackToolWindow, "ShowIDStackTool") end
    if data.ShowAbout then RunApp(ImGui.ShowAboutWindow, "ShowAbout") end
    if data.ShowStyleEditor then
        local visible
        data.ShowStyleEditor, visible = ImGui.Begin("Dear ImGui Style Editor", data.ShowStyleEditor)
        if visible then
            ImGui.ShowStyleEditor()
        end
        ImGui.End()
    end

    -- Demonstrate the various window flags. Typically you would just use the default!
    local W = ImGuiWindowFlags
    local window_flags = 0
    if no_titlebar       then window_flags = bit32.bor(window_flags, W.NoTitleBar) end
    if no_scrollbar      then window_flags = bit32.bor(window_flags, W.NoScrollbar) end
    if not no_menu       then window_flags = bit32.bor(window_flags, W.MenuBar) end
    if no_move           then window_flags = bit32.bor(window_flags, W.NoMove) end
    if no_resize         then window_flags = bit32.bor(window_flags, W.NoResize) end
    if no_collapse       then window_flags = bit32.bor(window_flags, W.NoCollapse) end
    if no_nav            then window_flags = bit32.bor(window_flags, W.NoNav) end
    if no_background     then window_flags = bit32.bor(window_flags, W.NoBackground) end
    if no_bring_to_front then window_flags = bit32.bor(window_flags, W.NoBringToFrontOnFocus) end
    if no_docking        then window_flags = bit32.bor(window_flags, W.NoDocking) end
    if unsaved_document  then window_flags = bit32.bor(window_flags, W.UnsavedDocument) end
    if no_close          then p_open = nil end -- Don't pass our bool* to Begin

    -- We specify a default position/size in case there's no data in the .ini file.
    -- We only do it to make the demo applications a little more welcoming, but typically this isn't required.
    local main_viewport = ImGui.GetMainViewport()
    ImGui.SetNextWindowPos(ImVec2(main_viewport.WorkPos.x + 650, main_viewport.WorkPos.y + 20), ImGuiCond.FirstUseEver)
    ImGui.SetNextWindowSize(ImVec2(550, 680), ImGuiCond.FirstUseEver)

    -- Main body of the Demo window starts here.
    local visible
    p_open, visible = ImGui.Begin("Dear ImGui Demo", p_open, window_flags)
    if no_close then p_open = nil end
    if not visible then
        -- Early out if the window is collapsed, as an optimization.
        ImGui.End()
        return p_open
    end

    -- Most framed widgets share a common width settings. Remaining width is used for the label.
    -- The width of the frame may be changed with PushItemWidth() or SetNextItemWidth().
    -- - Positive value for absolute size, negative value for right-alignment.
    -- - The default value is about GetWindowWidth() * 0.65f.
    -- - See 'Demo->Layout->Widgets Width' for details.
    -- Here we change the frame width based on how much width we want to give to the label.
    local label_width_base = ImGui.GetFontSize() * 12                  -- Some amount of width for label, based on font size.
    local label_width_max = ImGui.GetContentRegionAvail().x * 0.40     -- ...but always leave some room for framed widgets.
    local label_width = math.min(label_width_base, label_width_max)
    ImGui.PushItemWidth(-label_width)                                  -- Right-align: framed items will leave 'label_width' available for the label.
    -- ImGui.PushItemWidth(ImGui.GetContentRegionAvail().x * 0.40)      -- e.g. Use 40% width for framed widgets, leaving 60% width for labels.
    -- ImGui.PushItemWidth(-ImGui.GetContentRegionAvail().x * 0.40)     -- e.g. Use 40% width for labels, leaving 60% width for framed widgets.
    -- ImGui.PushItemWidth(ImGui.GetFontSize() * -12)                   -- e.g. Use XXX width for labels, leaving the rest for framed widgets.

    -- Menu Bar
    DemoWindowMenuBar(data)

    ImGui.Text("Dear ImGui says hello! (%s) (%d)", IMGUI_VERSION or "WIP", IMGUI_VERSION_NUM or 0)
    ImGui.Spacing()

    if ImGui.CollapsingHeader("Help") then
        IMGUI_DEMO_MARKER("Help")
        ImGui.SeparatorText("ABOUT THIS DEMO:")
        ImGui.BulletText("Sections below are demonstrating many aspects of the library.")
        ImGui.BulletText("The \"Examples\" menu above leads to more demo contents.")
        ImGui.BulletText("The \"Tools\" menu above gives access to: About Box, Style Editor,\n" ..
                         "and Metrics/Debugger (general purpose Dear ImGui debugging tool).")
        ImGui.BulletText("Web demo (w/ source code browser): ")
        ImGui.SameLine(0, 0)
        ImGui.TextLinkOpenURL("https://pthom.github.io/imgui_explorer")

        ImGui.SeparatorText("PROGRAMMER GUIDE:")
        ImGui.BulletText("See the ShowDemoWindow() code in imgui_demo.lua. <- you are here!")
        ImGui.BulletText("See comments in imgui.lua.")
        ImGui.BulletText("See example applications in the examples/ folder.")
        ImGui.BulletText("Read the FAQ at ")
        ImGui.SameLine(0, 0)
        ImGui.TextLinkOpenURL("https://www.dearimgui.com/faq/")
        ImGui.BulletText("Set 'io.ConfigFlags |= NavEnableKeyboard' for keyboard controls.")
        ImGui.BulletText("Set 'io.ConfigFlags |= NavEnableGamepad' for gamepad controls.")

        ImGui.SeparatorText("USER GUIDE:")
        ImGui.ShowUserGuide()
    end

    if ImGui.CollapsingHeader("Configuration") then
        DemoWindowConfiguration(ImGui.GetIO())
    end

    if ImGui.CollapsingHeader("Window options") then
        IMGUI_DEMO_MARKER("Window options")
        if ImGui.BeginTable("split", 3) then
            ImGui.TableNextColumn(); _, no_titlebar       = ImGui.Checkbox("No titlebar", no_titlebar)
            ImGui.TableNextColumn(); _, no_scrollbar      = ImGui.Checkbox("No scrollbar", no_scrollbar)
            ImGui.TableNextColumn(); _, no_menu           = ImGui.Checkbox("No menu", no_menu)
            ImGui.TableNextColumn(); _, no_move           = ImGui.Checkbox("No move", no_move)
            ImGui.TableNextColumn(); _, no_resize         = ImGui.Checkbox("No resize", no_resize)
            ImGui.TableNextColumn(); _, no_collapse       = ImGui.Checkbox("No collapse", no_collapse)
            ImGui.TableNextColumn(); _, no_close          = ImGui.Checkbox("No close", no_close)
            ImGui.TableNextColumn(); _, no_nav            = ImGui.Checkbox("No nav", no_nav)
            ImGui.TableNextColumn(); _, no_background     = ImGui.Checkbox("No background", no_background)
            ImGui.TableNextColumn(); _, no_bring_to_front = ImGui.Checkbox("No bring to front", no_bring_to_front)
            ImGui.TableNextColumn(); _, no_docking        = ImGui.Checkbox("No docking", no_docking)
            ImGui.TableNextColumn(); _, unsaved_document  = ImGui.Checkbox("Unsaved document", unsaved_document)
            ImGui.EndTable()
        end
    end

    -- All demo contents
    DemoWindowWidgets(data)
    if DemoWindowLayout then DemoWindowLayout() end
    if DemoWindowPopups then DemoWindowPopups() end
    if DemoWindowTables then DemoWindowTables() end
    if DemoWindowInputs then DemoWindowInputs() end

    -- End of ShowDemoWindow()
    ImGui.PopItemWidth()
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgets()
-------------------------------------------------------------------------------

--- Calls a (global) demo section if it exists, otherwise shows a placeholder
local function Sub(fn, title, ...)
    if fn then fn(...) else
        if ImGui.TreeNode(title) then DemoNotPorted(title) ImGui.TreePop() end
    end
end

function DemoWindowWidgets(data)
    -- ImGui.SetNextItemOpen(true, ImGuiCond.Once)
    if not ImGui.CollapsingHeader("Widgets") then
        return
    end
    -- IMGUI_DEMO_MARKER("Widgets")

    local disable_all = data.DisableSections -- The Checkbox for that is inside the "Disabled" section at the bottom
    local override_liveedit = data.LiveEditOverride
    if disable_all then
        ImGui.BeginDisabled()
    end
    if override_liveedit then
        ImGui.PushItemFlag(ImGuiItemFlags.LiveEditOnInputText, DemoHas(data.LiveEditFlags, ImGuiItemFlags.LiveEditOnInputText))
        ImGui.PushItemFlag(ImGuiItemFlags.LiveEditOnInputScalar, DemoHas(data.LiveEditFlags, ImGuiItemFlags.LiveEditOnInputScalar))
    end

    Sub(DemoWindowWidgetsBasic, "Basic")
    Sub(DemoWindowWidgetsBullets, "Bullets")
    Sub(DemoWindowWidgetsCollapsingHeaders, "Collapsing Headers")
    Sub(DemoWindowWidgetsComboBoxes, "Combo")
    Sub(DemoWindowWidgetsColorAndPickers, "Color/Picker Widgets")
    Sub(DemoWindowWidgetsDataTypes, "Data Types")

    if disable_all then
        ImGui.EndDisabled()
    end
    Sub(DemoWindowWidgetsDisableBlocks, "Disable Blocks", data)
    if disable_all then
        ImGui.BeginDisabled()
    end

    Sub(DemoWindowWidgetsDragAndDrop, "Drag and Drop")
    Sub(DemoWindowWidgetsDragsAndSliders, "Drag/Slider Flags")
    Sub(DemoWindowWidgetsFonts, "Fonts")
    Sub(DemoWindowWidgetsImages, "Images")
    Sub(DemoWindowWidgetsListBoxes, "List Boxes")
    Sub(DemoWindowWidgetsLiveEdit, "Live Edit Flags", data)
    Sub(DemoWindowWidgetsMixedValues, "Mixed Values")
    Sub(DemoWindowWidgetsMultiComponents, "Multi-component Widgets")
    Sub(DemoWindowWidgetsPlotting, "Plotting")
    Sub(DemoWindowWidgetsProgressBars, "Progress Bars")
    Sub(DemoWindowWidgetsQueryingStatuses, "Querying Item Status (Edited/Active/Hovered etc.)")
    Sub(DemoWindowWidgetsSelectables, "Selectables")
    Sub(DemoWindowWidgetsSelectionAndMultiSelect, "Selection State & Multi-Select", data)
    Sub(DemoWindowWidgetsTabs, "Tabs")
    Sub(DemoWindowWidgetsText, "Text")
    Sub(DemoWindowWidgetsTextFilter, "Text Filter")
    Sub(DemoWindowWidgetsTextInput, "Text Input")
    Sub(DemoWindowWidgetsTooltips, "Tooltips")
    Sub(DemoWindowWidgetsTreeNodes, "Tree Nodes")
    Sub(DemoWindowWidgetsVerticalSliders, "Vertical Sliders")

    if override_liveedit then
        ImGui.PopItemFlag()
        ImGui.PopItemFlag()
    end
    if disable_all then
        ImGui.EndDisabled()
    end
end

-------------------------------------------------------------------------------
-- [SECTION] User Guide / ShowUserGuide()
-------------------------------------------------------------------------------

function ImGui.ShowUserGuide()
    local io = ImGui.GetIO()
    ImGui.BulletText("Double-click on title bar to collapse window.")
    ImGui.BulletText(
        "Click and drag on lower corner or border to resize window.\n" ..
        "(double-click to auto fit window to its contents)")
    ImGui.BulletText("Ctrl+Click on a slider or drag box to input value as text.")
    ImGui.BulletText("Tab/Shift+Tab to cycle through keyboard editable fields.")
    ImGui.BulletText("Ctrl+Tab/Ctrl+Shift+Tab to focus windows.")
    if io.FontAllowUserScaling then
        ImGui.BulletText("Ctrl+Mouse Wheel to zoom window contents.")
    end
    ImGui.BulletText("While inputting text:\n")
    ImGui.Indent()
    ImGui.BulletText("Ctrl+Left/Right to word jump.")
    ImGui.BulletText("Ctrl+A or double-click to select all.")
    ImGui.BulletText("Ctrl+X/C/V to use clipboard cut/copy/paste.")
    ImGui.BulletText("Ctrl+Z to undo, Ctrl+Y/Ctrl+Shift+Z to redo.")
    ImGui.BulletText("Escape to revert.")
    ImGui.Unindent()
    ImGui.BulletText("With Keyboard controls enabled:")
    ImGui.Indent()
    ImGui.BulletText("Arrow keys or Home/End/PageUp/PageDown to navigate.")
    ImGui.BulletText("Space to activate a widget.")
    ImGui.BulletText("Return to input text into a widget.")
    ImGui.BulletText("Escape to deactivate a widget, close popup,\nexit a child window or the menu layer, clear focus.")
    ImGui.BulletText("Alt to jump to the menu layer of a window.")
    ImGui.BulletText("Menu or Shift+F10 to open a context menu.")
    ImGui.Unindent()
    ImGui.BulletText("With Gamepad controls enabled:")
    ImGui.Indent()
    ImGui.BulletText("D-Pad: Navigate / Tweak / Resize (in Windowing mode).")
    ImGui.BulletText("%s Face button: Activate / Open / Toggle. Hold: activate with text input.", io.ConfigNavSwapGamepadButtons and "East" or "South")
    ImGui.BulletText("%s Face button: Cancel / Close / Exit.", io.ConfigNavSwapGamepadButtons and "South" or "East")
    ImGui.BulletText("West Face button: Toggle Menu. Hold for Windowing mode (Focus/Move/Resize windows).")
    ImGui.BulletText("North Face button: Open Context Menu.")
    ImGui.BulletText("L1/R1: Tweak Slower/Faster, Focus Previous/Next (in Windowing Mode).")
    ImGui.Unindent()
end
end --[[ imgui_demo.lua ]]

do --[[ imgui_demo_2.lua ]]
--- Dear ImGui WIP
-- (Demo Code, part 2): DemoWindowLayout(), DemoWindowPopups(), DemoWindowTables(), DemoWindowColumns(),
-- DemoWindowInputs() and all ShowExampleAppXXX() example apps.
-- Port of imgui_demo.cpp (docking branch). Globals are shared with imgui_demo.lua (HelpMarker, ShowExampleMenuFile, ...)

-- Helpers macros
-- We normally try to not use many helpers in imgui_demo.cpp in order to make code easier to copy and paste,
-- but making an exception here as those are largely simplifying code...
-- In other imgui sources we can use nicer internal functions from imgui_internal.h (ImMin/ImMax) but not in the demo.
local IM_MIN = math.min
local IM_MAX = math.max
local function IM_CLAMP(V, MN, MX) return (V < MN) and MN or (V > MX) and MX or V end
local _
local function IMGUI_DEMO_MARKER(_) end -- upstream hook, no-op here

--- `char buf[size] = "str"` -> zero-terminated byte table
local function Buf(str, size)
    local t = {}
    for i = 1, #str do t[i] = string.byte(str, i) end
    t[#str + 1] = 0
    if size then for i = #str + 2, size do t[i] = 0 end end
    return t
end
--- byte table -> Lua string (up to the zero terminator)
local function BufStr(buf)
    local n = 0
    while buf[n + 1] ~= nil and buf[n + 1] ~= 0 do n = n + 1 end
    return ImGui._ByteArrayToString(buf, 1, n + 1)
end
local function BufSet(buf, str)
    for i = 1, #str do buf[i] = string.byte(str, i) end
    buf[#str + 1] = 0
end

--- ImColor::HSV() as ImVec4
local function HSV(h, s, v, a)
    local r, g, b = ImGui.ColorConvertHSVtoRGB(h, s, v)
    return ImVec4(r, g, b, a or 1.0)
end
local function B2I(b) return b and 1 or 0 end

local function Has(flags, f) return bit32.band(flags, f) ~= 0 end
local function NotSupported() ImGui.TextDisabled("(not supported on Roblox)") end
local function NotPorted(what) ImGui.TextDisabled("(not ported yet%s)", what and (": " .. what) or "") end

local function DemoHelpMarker(desc)
    if HelpMarker then HelpMarker(desc) return end
    ImGui.TextDisabled("(?)")
    if ImGui.BeginItemTooltip() then
        ImGui.PushTextWrapPos(ImGui.GetFontSize() * 35.0)
        ImGui.TextUnformatted(desc)
        ImGui.PopTextWrapPos()
        ImGui.EndTooltip()
    end
end
local function DemoMenuFile() if ShowExampleMenuFile then ShowExampleMenuFile() end end

--- Minimal ImGuiTextFilter stand-in when the library one isn't available
local function MakeTextFilter()
    if ImGuiTextFilter then return ImGuiTextFilter() end
    local f = { InputBuf = Buf("", 256) }
    function f:Draw(label, width)
        if width and width ~= 0 then ImGui.SetNextItemWidth(width) end
        return ImGui.InputText(label or "Filter (inc,-exc)", self.InputBuf, 256)
    end
    function f:IsActive() return self.InputBuf[1] ~= 0 end
    function f:Clear() self.InputBuf[1] = 0 end
    function f:Build() end
    function f:PassFilter(text, text_end)
        if text_end then text = string.sub(text, 1, text_end - 1) end
        local s = BufStr(self.InputBuf)
        if s == "" then return true end
        local any_inc, pass_inc = false, false
        for tok in string.gmatch(s, "[^,]+") do
            tok = string.match(tok, "^%s*(.-)%s*$")
            if tok ~= "" then
                if string.sub(tok, 1, 1) == "-" then
                    if #tok > 1 and string.find(string.lower(text), string.lower(string.sub(tok, 2)), 1, true) then return false end
                else
                    any_inc = true
                    if string.find(string.lower(text), string.lower(tok), 1, true) then pass_inc = true end
                end
            end
        end
        return (not any_inc) or pass_inc
    end
    return f
end

-- ImGuiInputTextCallbackData helpers (the port's callback data has no methods). Buf is a 1-based zero-terminated
-- byte table, positions are 0-based like C++.
local function CB_DeleteChars(data, pos, bytes_count)
    local buf = data.Buf
    local len = data.BufTextLen
    for i = pos + 1, len - bytes_count + 1 do buf[i] = buf[i + bytes_count] end
    for i = len - bytes_count + 2, len + 1 do buf[i] = 0 end
    if data.CursorPos >= pos + bytes_count then data.CursorPos = data.CursorPos - bytes_count
    elseif data.CursorPos >= pos then data.CursorPos = pos end
    data.SelectionStart = data.CursorPos; data.SelectionEnd = data.CursorPos
    data.BufDirty = true
    data.BufTextLen = len - bytes_count
end
local function CB_InsertChars(data, pos, text)
    local n = #text
    if n == 0 then return end
    if data.BufTextLen + n >= data.BufSize then return end
    local buf = data.Buf
    for i = data.BufTextLen + 1, pos + 1, -1 do buf[i + n] = buf[i] end
    for i = 1, n do buf[pos + i] = string.byte(text, i) end
    if data.CursorPos >= pos then data.CursorPos = data.CursorPos + n end
    data.SelectionStart = data.CursorPos; data.SelectionEnd = data.CursorPos
    data.BufDirty = true
    data.BufTextLen = data.BufTextLen + n
end
local function CB_SelectAll(data) data.SelectionStart = 0; data.SelectionEnd = data.BufTextLen end

--- ImGui::BeginChild() wrapper accepting upstream args
local function BeginChild(id, size, child_flags, window_flags)
    return ImGui.BeginChild(id, size or ImVec2(0, 0), child_flags or 0, window_flags or 0)
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowLayout()
-------------------------------------------------------------------------------

local SL = {
    disable_mouse_wheel = false, disable_menu = false,
    draw_lines = 3, max_height_in_lines = 10,
    offset_x = 0, override_bg_color = true, child_flags = nil,
    f = 0.0, show_indented_items = true,
    c1 = false, c2 = false, c3 = false, c4 = false,
    f0 = 1.0, f1 = 2.0, f2 = 3.0, item = -1, selection = { 0, 1, 2, 3 },
    track_item = 50, enable_track = true, enable_extra_decorations = false, scroll_to_off_px = 0.0, scroll_to_pos_px = 200.0,
    lines = 7, show_horizontal_contents_size_demo_window = false,
    show_h_scrollbar = true, show_button = true, show_tree_nodes = true, show_text_wrapped = false, show_columns = true,
    show_tab_bar = true, show_child = false, explicit_content_size = false, contents_size_x = 300.0,
    clip_size = nil, clip_offset = nil,
    enable_allow_overlap = true,
}

local function DemoWindowLayout_ChildWindows()
    IMGUI_DEMO_MARKER("Layout/Child windows")
    ImGui.SeparatorText("Child windows")

    DemoHelpMarker("Use child windows to begin into a self-contained independent scrolling/clipping regions within a host window.")
    _, SL.disable_mouse_wheel = ImGui.Checkbox("Disable Mouse Wheel", SL.disable_mouse_wheel)
    _, SL.disable_menu = ImGui.Checkbox("Disable Menu", SL.disable_menu)

    -- Child 1: no border, enable horizontal scrollbar
    do
        local window_flags = ImGuiWindowFlags.HorizontalScrollbar
        if SL.disable_mouse_wheel then
            window_flags = bit32.bor(window_flags, ImGuiWindowFlags.NoScrollWithMouse)
        end
        BeginChild("ChildL", ImVec2(ImGui.GetContentRegionAvail().x * 0.5, 260), ImGuiChildFlags.None, window_flags)
        for i = 0, 99 do
            ImGui.Text("%04d: scrollable region", i)
        end
        ImGui.EndChild()
    end

    ImGui.SameLine()

    -- Child 2: rounded border
    do
        local window_flags = ImGuiWindowFlags.None
        if SL.disable_mouse_wheel then
            window_flags = bit32.bor(window_flags, ImGuiWindowFlags.NoScrollWithMouse)
        end
        if not SL.disable_menu then
            window_flags = bit32.bor(window_flags, ImGuiWindowFlags.MenuBar)
        end
        ImGui.PushStyleVar(ImGuiStyleVar.ChildRounding, 5.0)
        BeginChild("ChildR", ImVec2(0, 260), ImGuiChildFlags.Borders, window_flags)
        if not SL.disable_menu and ImGui.BeginMenuBar() then
            if ImGui.BeginMenu("Menu") then
                DemoMenuFile()
                ImGui.EndMenu()
            end
            ImGui.EndMenuBar()
        end
        if ImGui.BeginTable("split", 2, bit32.bor(ImGuiTableFlags.Resizable, ImGuiTableFlags.NoSavedSettings)) then
            for i = 0, 99 do
                local buf = string.format("%03d", i)
                ImGui.TableNextColumn()
                ImGui.Button(buf, ImVec2(-FLT_MIN, 0.0))
            end
            ImGui.EndTable()
        end
        ImGui.EndChild()
        ImGui.PopStyleVar()
    end

    -- Child 3: manual-resize
    ImGui.SeparatorText("Manual-resize")
    do
        DemoHelpMarker("Drag bottom border to resize. Double-click bottom border to auto-fit to vertical contents.")
        -- if ImGui.Button("Set Height to 200") then
        --     ImGui.SetNextWindowSize(ImVec2(-FLT_MIN, 200.0))
        -- end

        ImGui.PushStyleColor(ImGuiCol.ChildBg, ImGui.GetStyleColorVec4(ImGuiCol.FrameBg))
        if BeginChild("ResizableChild", ImVec2(-FLT_MIN, ImGui.GetTextLineHeightWithSpacing() * 8), bit32.bor(ImGuiChildFlags.Borders, ImGuiChildFlags.ResizeY)) then
            for n = 0, 9 do
                ImGui.Text("Line %04d", n)
            end
        end
        ImGui.PopStyleColor()
        ImGui.EndChild()
    end

    -- Child 4: auto-resizing height with a limit
    ImGui.SeparatorText("Auto-resize with constraints")
    do
        ImGui.SetNextItemWidth(ImGui.GetFontSize() * 8)
        SL.draw_lines = ImGui.DragInt("Lines Count", SL.draw_lines, 0.2)
        ImGui.SetNextItemWidth(ImGui.GetFontSize() * 8)
        SL.max_height_in_lines = ImGui.DragInt("Max Height (in Lines)", SL.max_height_in_lines, 0.2)

        ImGui.SetNextWindowSizeConstraints(ImVec2(0.0, ImGui.GetTextLineHeightWithSpacing() * 1), ImVec2(FLT_MAX, ImGui.GetTextLineHeightWithSpacing() * SL.max_height_in_lines))
        if BeginChild("ConstrainedChild", ImVec2(-FLT_MIN, 0.0), bit32.bor(ImGuiChildFlags.Borders, ImGuiChildFlags.AutoResizeY)) then
            for n = 0, SL.draw_lines - 1 do
                ImGui.Text("Line %04d", n)
            end
        end
        ImGui.EndChild()
    end

    ImGui.SeparatorText("Misc/Advanced")

    -- Demonstrate a few extra things
    -- - Changing ImGuiCol.ChildBg (which is transparent black in default styles)
    -- - Using SetCursorPos() to position child window (the child window is an item from the POV of parent window)
    --   You can also call SetNextWindowPos() to position the child window. The parent window will effectively
    --   layout from this position.
    -- - Using ImGui.GetItemRectMin/Max() to query the "item" state (because the child window is an item from
    --   the POV of the parent window). See 'Demo->Querying Status (Edited/Active/Hovered etc.)' for details.
    do
        if SL.child_flags == nil then SL.child_flags = bit32.bor(ImGuiChildFlags.Borders, ImGuiChildFlags.ResizeX, ImGuiChildFlags.ResizeY) end
        ImGui.SetNextItemWidth(ImGui.GetFontSize() * 8)
        SL.offset_x = ImGui.DragInt("Offset X", SL.offset_x, 1.0, -1000, 1000)
        _, SL.override_bg_color = ImGui.Checkbox("Override ChildBg color", SL.override_bg_color)
        _, SL.child_flags = ImGui.CheckboxFlags("ImGuiChildFlags_Borders", SL.child_flags, ImGuiChildFlags.Borders)
        _, SL.child_flags = ImGui.CheckboxFlags("ImGuiChildFlags_AlwaysUseWindowPadding", SL.child_flags, ImGuiChildFlags.AlwaysUseWindowPadding)
        _, SL.child_flags = ImGui.CheckboxFlags("ImGuiChildFlags_ResizeX", SL.child_flags, ImGuiChildFlags.ResizeX)
        _, SL.child_flags = ImGui.CheckboxFlags("ImGuiChildFlags_ResizeY", SL.child_flags, ImGuiChildFlags.ResizeY)
        _, SL.child_flags = ImGui.CheckboxFlags("ImGuiChildFlags_FrameStyle", SL.child_flags, ImGuiChildFlags.FrameStyle)
        ImGui.SameLine(); DemoHelpMarker("Style the child window like a framed item: use FrameBg, FrameRounding, FrameBorderSize, FramePadding instead of ChildBg, ChildRounding, ChildBorderSize, WindowPadding.")
        if Has(SL.child_flags, ImGuiChildFlags.FrameStyle) then
            SL.override_bg_color = false
        end

        ImGui.SetCursorPosX(ImGui.GetCursorPosX() + SL.offset_x)
        if SL.override_bg_color then
            ImGui.PushStyleColor(ImGuiCol.ChildBg, IM_COL32(255, 0, 0, 100))
        end
        BeginChild("Red", ImVec2(200, 100), SL.child_flags, ImGuiWindowFlags.None)
        if SL.override_bg_color then
            ImGui.PopStyleColor()
        end

        for n = 0, 49 do
            ImGui.Text("Some test %d", n)
        end
        ImGui.EndChild()
        local child_is_hovered = ImGui.IsItemHovered()
        local child_rect_min = ImGui.GetItemRectMin()
        local child_rect_max = ImGui.GetItemRectMax()
        ImGui.Text("Hovered: %d", B2I(child_is_hovered))
        ImGui.Text("Rect of child window is: (%.0f,%.0f) (%.0f,%.0f)", child_rect_min.x, child_rect_min.y, child_rect_max.x, child_rect_max.y)
    end
end

local function DemoWindowLayout_WidgetsWidth()
    IMGUI_DEMO_MARKER("Layout/Widgets Width")
    _, SL.show_indented_items = ImGui.Checkbox("Show indented items", SL.show_indented_items)

    -- Use SetNextItemWidth() to set the width of a single upcoming item.
    -- Use PushItemWidth()/PopItemWidth() to set the width of a group of items.
    -- In real code use you'll probably want to choose width values that are proportional to your font size
    -- e.g. Using '20.0f * GetFontSize()' as width instead of '200.0f', etc.

    local function block(text, help, width, l1, l2)
        ImGui.Text(text)
        if help then ImGui.SameLine(); DemoHelpMarker(help) end
        ImGui.PushItemWidth(width)
        SL.f = ImGui.DragFloat(l1, SL.f)
        if SL.show_indented_items then
            ImGui.Indent()
            SL.f = ImGui.DragFloat(l2, SL.f)
            ImGui.Unindent()
        end
        ImGui.PopItemWidth()
    end
    block("SetNextItemWidth/PushItemWidth(100)", "Fixed width.", 100, "float##1b", "float (indented)##1b")
    block("SetNextItemWidth/PushItemWidth(-100)", "Align to right edge minus 100", -100, "float##2a", "float (indented)##2b")
    block("SetNextItemWidth/PushItemWidth(GetContentRegionAvail().x * 0.5f)", "Half of available width.\n(~ right-cursor_pos)\n(works within a column set)", ImGui.GetContentRegionAvail().x * 0.5, "float##3a", "float (indented)##3b")
    block("SetNextItemWidth/PushItemWidth(-GetContentRegionAvail().x * 0.5f)", "Align to right edge minus half", -ImGui.GetContentRegionAvail().x * 0.5, "float##4a", "float (indented)##4b")
    block("SetNextItemWidth/PushItemWidth(-Min(GetContentRegionAvail().x * 0.40f, GetFontSize() * 12))", nil, -IM_MIN(ImGui.GetFontSize() * 12, ImGui.GetContentRegionAvail().x * 0.40), "float##5a", "float (indented)##5b")
    -- Demonstrate using PushItemWidth to surround three items.
    -- Calling SetNextItemWidth() before each of them would have the same effect.
    block("SetNextItemWidth/PushItemWidth(-FLT_MIN)", "Align to right edge", -FLT_MIN, "##float6a", "float (indented)##6b")
end

local function DemoWindowLayout_BasicHorizontal()
    IMGUI_DEMO_MARKER("Layout/Basic Horizontal Layout")
    ImGui.TextWrapped("(Use ImGui::SameLine() to keep adding items to the right of the preceding item)")

    -- Text
    IMGUI_DEMO_MARKER("Layout/Basic Horizontal Layout/SameLine")
    ImGui.Text("Two items: Hello"); ImGui.SameLine()
    ImGui.TextColored(ImVec4(1, 1, 0, 1), "Sailor")

    -- Adjust spacing
    ImGui.Text("More spacing: Hello"); ImGui.SameLine(0, 20)
    ImGui.TextColored(ImVec4(1, 1, 0, 1), "Sailor")

    -- Button
    ImGui.AlignTextToFramePadding()
    ImGui.Text("Normal buttons"); ImGui.SameLine()
    ImGui.Button("Banana"); ImGui.SameLine()
    ImGui.Button("Apple"); ImGui.SameLine()
    ImGui.Button("Corniflower")

    -- Button
    ImGui.Text("Small buttons"); ImGui.SameLine()
    ImGui.SmallButton("Like this one"); ImGui.SameLine()
    ImGui.Text("can fit within a text block.")

    -- Aligned to arbitrary position. Easy/cheap column.
    IMGUI_DEMO_MARKER("Layout/Basic Horizontal Layout/SameLine (with offset)")
    ImGui.Text("Aligned")
    ImGui.SameLine(150); ImGui.Text("x=150")
    ImGui.SameLine(300); ImGui.Text("x=300")
    ImGui.Text("Aligned")
    ImGui.SameLine(150); ImGui.SmallButton("x=150")
    ImGui.SameLine(300); ImGui.SmallButton("x=300")

    -- Checkbox
    IMGUI_DEMO_MARKER("Layout/Basic Horizontal Layout/SameLine (more)")
    _, SL.c1 = ImGui.Checkbox("My", SL.c1); ImGui.SameLine()
    _, SL.c2 = ImGui.Checkbox("Tailor", SL.c2); ImGui.SameLine()
    _, SL.c3 = ImGui.Checkbox("Is", SL.c3); ImGui.SameLine()
    _, SL.c4 = ImGui.Checkbox("Rich", SL.c4)

    -- Various
    ImGui.PushItemWidth(ImGui.CalcTextSize("AAAAAAA").x)
    local items = { "AAAA", "BBBB", "CCCC", "DDDD" }
    if ImGui.Combo then
        SL.item = ImGui.Combo("Combo", SL.item, items, #items)
    else
        NotPorted("Combo")
    end
    ImGui.SameLine()
    SL.f0 = ImGui.SliderFloat("X", SL.f0, 0.0, 5.0); ImGui.SameLine()
    SL.f1 = ImGui.SliderFloat("Y", SL.f1, 0.0, 5.0); ImGui.SameLine()
    SL.f2 = ImGui.SliderFloat("Z", SL.f2, 0.0, 5.0)

    ImGui.Text("Lists:")
    for i = 1, 4 do
        if i > 1 then ImGui.SameLine() end
        ImGui.PushID(i - 1)
        if ImGui.ListBox then
            SL.selection[i] = ImGui.ListBox("", SL.selection[i], items, #items)
        else
            NotPorted("ListBox")
        end
        ImGui.PopID()
        -- ImGui.SetItemTooltip("ListBox %d hovered", i)
    end
    ImGui.PopItemWidth()

    -- Dummy
    IMGUI_DEMO_MARKER("Layout/Basic Horizontal Layout/Dummy")
    local button_sz = ImVec2(40, 40)
    ImGui.Button("A", button_sz); ImGui.SameLine()
    ImGui.Dummy(button_sz); ImGui.SameLine()
    ImGui.Button("B", button_sz)

    -- Manually wrapping
    -- (we should eventually provide this as an automatic layout feature, but for now you can do it manually)
    IMGUI_DEMO_MARKER("Layout/Basic Horizontal Layout/Manual wrapping")
    ImGui.Text("Manual wrapping:")
    local style = ImGui.GetStyle()
    local buttons_count = 20
    local window_visible_x2 = ImGui.GetCursorScreenPos().x + ImGui.GetContentRegionAvail().x
    for n = 0, buttons_count - 1 do
        ImGui.PushID(n)
        ImGui.Button("Box", button_sz)
        local last_button_x2 = ImGui.GetItemRectMax().x
        local next_button_x2 = last_button_x2 + style.ItemSpacing.x + button_sz.x -- Expected position if next button was on same line
        if n + 1 < buttons_count and next_button_x2 < window_visible_x2 then
            ImGui.SameLine()
        end
        ImGui.PopID()
    end
end

local function DemoWindowLayout_Groups()
    IMGUI_DEMO_MARKER("Layout/Groups")
    DemoHelpMarker(
        "BeginGroup() basically locks the horizontal position for new line. " ..
        "EndGroup() bundles the whole group so that you can use \"item\" functions such as " ..
        "IsItemHovered()/IsItemActive() or SameLine() etc. on the whole group.")
    ImGui.BeginGroup()
    do
        ImGui.BeginGroup()
        ImGui.Button("AAA")
        ImGui.SameLine()
        ImGui.Button("BBB")
        ImGui.SameLine()
        ImGui.BeginGroup()
        ImGui.Button("CCC")
        ImGui.Button("DDD")
        ImGui.EndGroup()
        ImGui.SameLine()
        ImGui.Button("EEE")
        ImGui.EndGroup()
        ImGui.SetItemTooltip("First group hovered")
    end
    -- Capture the group size and create widgets using the same size
    local size = ImGui.GetItemRectSize()
    local values = { 0.5, 0.20, 0.80, 0.60, 0.25 }
    ImGui.PlotHistogram("##values", values, nil, #values, 0, nil, 0.0, 1.0, size)

    ImGui.Button("ACTION", ImVec2((size.x - ImGui.GetStyle().ItemSpacing.x) * 0.5, size.y))
    ImGui.SameLine()
    ImGui.Button("REACTION", ImVec2((size.x - ImGui.GetStyle().ItemSpacing.x) * 0.5, size.y))
    ImGui.EndGroup()
    ImGui.SameLine()

    ImGui.Button("LEVERAGE\nBUZZWORD", size)
    ImGui.SameLine()

    if ImGui.BeginListBox and ImGui.BeginListBox("List", size) then
        ImGui.Selectable("Selected", true)
        ImGui.Selectable("Not Selected", false)
        ImGui.EndListBox()
    end
end

local function DemoWindowLayout_TextBaseline()
    IMGUI_DEMO_MARKER("Layout/Text Baseline Alignment")
    do
        ImGui.BulletText("Text baseline:")
        ImGui.SameLine(); DemoHelpMarker(
            "This is testing the vertical alignment that gets applied on text to keep it aligned with widgets. " ..
            "Lines only composed of text or \"small\" widgets use less vertical space than lines with framed widgets.")
        ImGui.Indent()

        ImGui.Text("KO Blahblah"); ImGui.SameLine()
        ImGui.Button("Some framed item"); ImGui.SameLine()
        DemoHelpMarker("Baseline of button will look misaligned with text..")

        -- If your line starts with text, call AlignTextToFramePadding() to align text to upcoming widgets.
        -- (because we don't know what's coming after the Text() statement, we need to move the text baseline
        -- down by FramePadding.y ahead of time)
        ImGui.AlignTextToFramePadding()
        ImGui.Text("OK Blahblah"); ImGui.SameLine()
        ImGui.Button("Some framed item##2"); ImGui.SameLine()
        DemoHelpMarker("We call AlignTextToFramePadding() to vertically align the text baseline by +FramePadding.y")

        -- SmallButton() uses the same vertical padding as Text
        ImGui.Button("TEST##1"); ImGui.SameLine()
        ImGui.Text("TEST"); ImGui.SameLine()
        ImGui.SmallButton("TEST##2")

        -- If your line starts with text, call AlignTextToFramePadding() to align text to upcoming widgets.
        ImGui.AlignTextToFramePadding()
        ImGui.Text("Text aligned to framed item"); ImGui.SameLine()
        ImGui.Button("Item##1"); ImGui.SameLine()
        ImGui.Text("Item"); ImGui.SameLine()
        ImGui.SmallButton("Item##2"); ImGui.SameLine()
        ImGui.Button("Item##3")

        ImGui.Unindent()
    end

    ImGui.Spacing()

    do
        ImGui.BulletText("Multi-line text:")
        ImGui.Indent()
        ImGui.Text("One\nTwo\nThree"); ImGui.SameLine()
        ImGui.Text("Hello\nWorld"); ImGui.SameLine()
        ImGui.Text("Banana")

        ImGui.Text("Banana"); ImGui.SameLine()
        ImGui.Text("Hello\nWorld"); ImGui.SameLine()
        ImGui.Text("One\nTwo\nThree")

        ImGui.Button("HOP##1"); ImGui.SameLine()
        ImGui.Text("Banana"); ImGui.SameLine()
        ImGui.Text("Hello\nWorld"); ImGui.SameLine()
        ImGui.Text("Banana")

        ImGui.Button("HOP##2"); ImGui.SameLine()
        ImGui.Text("Hello\nWorld"); ImGui.SameLine()
        ImGui.Text("Banana")
        ImGui.Unindent()
    end

    ImGui.Spacing()

    do
        ImGui.BulletText("Misc items:")
        ImGui.Indent()

        -- SmallButton() sets FramePadding to zero. Text baseline is aligned to match baseline of previous Button.
        ImGui.Button("80x80", ImVec2(80, 80))
        ImGui.SameLine()
        ImGui.Button("50x50", ImVec2(50, 50))
        ImGui.SameLine()
        ImGui.Button("Button()")
        ImGui.SameLine()
        ImGui.SmallButton("SmallButton()")

        -- Tree
        -- (here the node appears after a button and has odd intent, so we use ImGuiTreeNodeFlags.DrawLinesNone to disable hierarchy outline)
        local spacing = ImGui.GetStyle().ItemInnerSpacing.x
        ImGui.Button("Button##1") -- Will make line higher
        ImGui.SameLine(0.0, spacing)
        if ImGui.TreeNodeEx("Node##1", ImGuiTreeNodeFlags.DrawLinesNone) then
            -- Placeholder tree data
            for i = 0, 5 do
                ImGui.BulletText("Item %d..", i)
            end
            ImGui.TreePop()
        end

        local padding = math.floor(ImGui.GetFontSize() * 1.20) -- Large padding
        ImGui.PushStyleVarY(ImGuiStyleVar.FramePadding, padding)
        ImGui.Button("Button##2")
        ImGui.PopStyleVar()
        ImGui.SameLine(0.0, spacing)
        if ImGui.TreeNodeEx("Node##2", ImGuiTreeNodeFlags.DrawLinesNone) then
            ImGui.TreePop()
        end

        -- Vertically align text node a bit lower so it'll be vertically centered with upcoming widget.
        -- Otherwise you can use SmallButton() (smaller fit).
        ImGui.AlignTextToFramePadding()

        -- Common mistake to avoid: if we want to SameLine after TreeNode we need to do it before we add
        -- other contents "inside" the node.
        local node_open = ImGui.TreeNode("Node##3")
        ImGui.SameLine(0.0, spacing); ImGui.Button("Button##3")
        if node_open then
            -- Placeholder tree data
            for i = 0, 5 do
                ImGui.BulletText("Item %d..", i)
            end
            ImGui.TreePop()
        end

        -- Bullet
        ImGui.Button("Button##4")
        ImGui.SameLine(0.0, spacing)
        ImGui.BulletText("Bullet text")

        ImGui.AlignTextToFramePadding()
        ImGui.BulletText("Node")
        ImGui.SameLine(0.0, spacing); ImGui.Button("Button##5")
        ImGui.Unindent()
    end
end

local function DemoWindowLayout_HorizontalContentsSizeWindow()
    if SL.explicit_content_size then
        ImGui.SetNextWindowContentSize(ImVec2(SL.contents_size_x, 0.0))
    end
    SL.show_horizontal_contents_size_demo_window = ImGui.Begin("Horizontal contents size demo window", SL.show_horizontal_contents_size_demo_window, SL.show_h_scrollbar and ImGuiWindowFlags.HorizontalScrollbar or 0)
    IMGUI_DEMO_MARKER("Layout/Scrolling/Horizontal contents size demo window")
    ImGui.PushStyleVar(ImGuiStyleVar.ItemSpacing, ImVec2(2, 0))
    ImGui.PushStyleVar(ImGuiStyleVar.FramePadding, ImVec2(2, 0))
    DemoHelpMarker(
        "Test how different widgets react and impact the work rectangle growing when horizontal scrolling is enabled.\n\n" ..
        "Use 'Metrics->Tools->Show windows rectangles' to visualize rectangles.")
    _, SL.show_h_scrollbar = ImGui.Checkbox("H-scrollbar", SL.show_h_scrollbar)
    _, SL.show_button = ImGui.Checkbox("Button", SL.show_button) -- Will grow contents size (unless explicitly overwritten)
    _, SL.show_tree_nodes = ImGui.Checkbox("Tree nodes", SL.show_tree_nodes) -- Will grow contents size and display highlight over full width
    _, SL.show_text_wrapped = ImGui.Checkbox("Text wrapped", SL.show_text_wrapped) -- Will grow and use contents size
    _, SL.show_columns = ImGui.Checkbox("Columns", SL.show_columns) -- Will use contents size
    _, SL.show_tab_bar = ImGui.Checkbox("Tab bar", SL.show_tab_bar) -- Will use contents size
    _, SL.show_child = ImGui.Checkbox("Child", SL.show_child) -- Will grow and use contents size
    _, SL.explicit_content_size = ImGui.Checkbox("Explicit content size", SL.explicit_content_size)
    ImGui.Text("Scroll %.1f/%.1f %.1f/%.1f", ImGui.GetScrollX(), ImGui.GetScrollMaxX(), ImGui.GetScrollY(), ImGui.GetScrollMaxY())
    if SL.explicit_content_size then
        ImGui.SameLine()
        ImGui.SetNextItemWidth(ImGui.CalcTextSize("123456").x)
        SL.contents_size_x = ImGui.DragFloat("##csx", SL.contents_size_x)
        local p = ImGui.GetCursorScreenPos()
        ImGui.GetWindowDrawList():AddRectFilled(p, ImVec2(p.x + 10, p.y + 10), IM_COL32_WHITE)
        ImGui.GetWindowDrawList():AddRectFilled(ImVec2(p.x + SL.contents_size_x - 10, p.y), ImVec2(p.x + SL.contents_size_x, p.y + 10), IM_COL32_WHITE)
        ImGui.Dummy(ImVec2(0, 10))
    end
    ImGui.PopStyleVar(2)
    ImGui.Separator()
    if SL.show_button then
        ImGui.Button("this is a 300-wide button", ImVec2(300, 0))
    end
    if SL.show_tree_nodes then
        local open = true
        if ImGui.TreeNode("this is a tree node") then
            if ImGui.TreeNode("another one of those tree node...") then
                ImGui.Text("Some tree contents")
                ImGui.TreePop()
            end
            ImGui.TreePop()
        end
        ImGui.CollapsingHeader("CollapsingHeader", open)
    end
    if SL.show_text_wrapped then
        ImGui.TextWrapped("This text should automatically wrap on the edge of the work rectangle.")
    end
    if SL.show_columns then
        ImGui.Text("Tables:")
        if ImGui.BeginTable("table", 4, ImGuiTableFlags.Borders) then
            for n = 0, 3 do
                ImGui.TableNextColumn()
                ImGui.Text("Width %.2f", ImGui.GetContentRegionAvail().x)
            end
            ImGui.EndTable()
        end
        ImGui.Text("Columns:")
        if ImGui.Columns then
            ImGui.Columns(4)
            for n = 0, 3 do
                ImGui.Text("Width %.2f", ImGui.GetColumnWidth())
                ImGui.NextColumn()
            end
            ImGui.Columns(1)
        else
            NotPorted("Columns")
        end
    end
    if SL.show_tab_bar and ImGui.BeginTabBar and ImGui.BeginTabBar("Hello") then
        if ImGui.BeginTabItem("OneOneOne") then ImGui.EndTabItem() end
        if ImGui.BeginTabItem("TwoTwoTwo") then ImGui.EndTabItem() end
        if ImGui.BeginTabItem("ThreeThreeThree") then ImGui.EndTabItem() end
        if ImGui.BeginTabItem("FourFourFour") then ImGui.EndTabItem() end
        ImGui.EndTabBar()
    end
    if SL.show_child then
        BeginChild("child", ImVec2(0, 0), ImGuiChildFlags.Borders)
        ImGui.EndChild()
    end
    ImGui.End()
end

local function DemoWindowLayout_Scrolling()
    IMGUI_DEMO_MARKER("Layout/Scrolling/Vertical")
    -- Vertical scroll functions
    DemoHelpMarker("Use SetScrollHereY() or SetScrollFromPosY() to scroll to a given vertical position.")

    _, SL.enable_extra_decorations = ImGui.Checkbox("Decoration", SL.enable_extra_decorations)

    ImGui.PushItemWidth(ImGui.GetFontSize() * 10)
    local changed
    SL.track_item, changed = ImGui.DragInt("##item", SL.track_item, 0.25, 0, 99, "Item = %d")
    SL.enable_track = SL.enable_track or changed
    ImGui.SameLine()
    _, SL.enable_track = ImGui.Checkbox("Track", SL.enable_track)

    local scroll_to_off
    SL.scroll_to_off_px, scroll_to_off = ImGui.DragFloat("##off", SL.scroll_to_off_px, 1.00, 0, FLT_MAX, "+%.0f px")
    ImGui.SameLine()
    scroll_to_off = ImGui.Button("Scroll Offset") or scroll_to_off

    local scroll_to_pos
    SL.scroll_to_pos_px, scroll_to_pos = ImGui.DragFloat("##pos", SL.scroll_to_pos_px, 1.00, -10, FLT_MAX, "X/Y = %.0f px")
    ImGui.SameLine()
    scroll_to_pos = ImGui.Button("Scroll To Pos") or scroll_to_pos
    ImGui.PopItemWidth()

    if scroll_to_off or scroll_to_pos then
        SL.enable_track = false
    end

    local style = ImGui.GetStyle()
    local child_w = (ImGui.GetContentRegionAvail().x - 4 * style.ItemSpacing.x) / 5
    if child_w < 1.0 then
        child_w = 1.0
    end
    ImGui.PushID("##VerticalScrolling")
    local vnames = { "Top", "25%", "Center", "75%", "Bottom" }
    for i = 0, 4 do
        if i > 0 then ImGui.SameLine() end
        ImGui.BeginGroup()
        ImGui.TextUnformatted(vnames[i + 1])

        local child_flags = SL.enable_extra_decorations and ImGuiWindowFlags.MenuBar or 0
        local child_id = ImGui.GetID(i)
        local child_is_visible = BeginChild(child_id, ImVec2(child_w, 200.0), ImGuiChildFlags.Borders, child_flags)
        if ImGui.BeginMenuBar() then
            ImGui.TextUnformatted("abc")
            ImGui.EndMenuBar()
        end
        if scroll_to_off then
            ImGui.SetScrollY(SL.scroll_to_off_px)
        end
        if scroll_to_pos then
            ImGui.SetScrollFromPosY(ImGui.GetCursorStartPos().y + SL.scroll_to_pos_px, i * 0.25)
        end
        if child_is_visible then -- Avoid calling SetScrollHereY when running with culled items
            for item = 0, 99 do
                if SL.enable_track and item == SL.track_item then
                    ImGui.TextColored(ImVec4(1, 1, 0, 1), "Item %d", item)
                    ImGui.SetScrollHereY(i * 0.25) -- 0.0f:top, 0.5f:center, 1.0f:bottom
                else
                    ImGui.Text("Item %d", item)
                end
            end
        end
        local scroll_y = ImGui.GetScrollY()
        local scroll_max_y = ImGui.GetScrollMaxY()
        ImGui.EndChild()
        ImGui.Text("%.0f/%.0f", scroll_y, scroll_max_y)
        ImGui.EndGroup()
    end
    ImGui.PopID()

    -- Horizontal scroll functions
    IMGUI_DEMO_MARKER("Layout/Scrolling/Horizontal")
    ImGui.Spacing()
    DemoHelpMarker(
        "Use SetScrollHereX() or SetScrollFromPosX() to scroll to a given horizontal position.\n\n" ..
        "Because the clipping rectangle of most window hides half worth of WindowPadding on the " ..
        "left/right, using SetScrollFromPosX(+1) will usually result in clipped text whereas the " ..
        "equivalent SetScrollFromPosY(+1) wouldn't.")
    ImGui.PushID("##HorizontalScrolling")
    local hnames = { "Left", "25%", "Center", "75%", "Right" }
    for i = 0, 4 do
        local child_height = ImGui.GetTextLineHeight() + style.ScrollbarSize + style.WindowPadding.y * 2.0
        local child_flags = bit32.bor(ImGuiWindowFlags.HorizontalScrollbar, SL.enable_extra_decorations and ImGuiWindowFlags.AlwaysVerticalScrollbar or 0)
        local child_id = ImGui.GetID(i)
        local child_is_visible = BeginChild(child_id, ImVec2(-100, child_height), ImGuiChildFlags.Borders, child_flags)
        if scroll_to_off then
            ImGui.SetScrollX(SL.scroll_to_off_px)
        end
        if scroll_to_pos then
            ImGui.SetScrollFromPosX(ImGui.GetCursorStartPos().x + SL.scroll_to_pos_px, i * 0.25)
        end
        if child_is_visible then -- Avoid calling SetScrollHereY when running with culled items
            for item = 0, 99 do
                if item > 0 then
                    ImGui.SameLine()
                end
                if SL.enable_track and item == SL.track_item then
                    ImGui.TextColored(ImVec4(1, 1, 0, 1), "Item %d", item)
                    ImGui.SetScrollHereX(i * 0.25) -- 0.0f:left, 0.5f:center, 1.0f:right
                else
                    ImGui.Text("Item %d", item)
                end
            end
        end
        local scroll_x = ImGui.GetScrollX()
        local scroll_max_x = ImGui.GetScrollMaxX()
        ImGui.EndChild()
        ImGui.SameLine()
        ImGui.Text("%s\n%.0f/%.0f", hnames[i + 1], scroll_x, scroll_max_x)
        ImGui.Spacing()
    end
    ImGui.PopID()

    -- Miscellaneous Horizontal Scrolling Demo
    IMGUI_DEMO_MARKER("Layout/Scrolling/Horizontal (more)")
    DemoHelpMarker(
        "Horizontal scrolling for a window is enabled via the ImGuiWindowFlags_HorizontalScrollbar flag.\n\n" ..
        "You may want to also explicitly specify content width by using SetNextWindowContentWidth() before Begin().")
    SL.lines = ImGui.SliderInt("Lines", SL.lines, 1, 15)
    ImGui.PushStyleVar(ImGuiStyleVar.FrameRounding, 3.0)
    ImGui.PushStyleVar(ImGuiStyleVar.FramePadding, ImVec2(2.0, 1.0))
    local scrolling_child_size = ImVec2(0, ImGui.GetFrameHeightWithSpacing() * 7 + 30)
    BeginChild("scrolling", scrolling_child_size, ImGuiChildFlags.Borders, ImGuiWindowFlags.HorizontalScrollbar)
    for line = 0, SL.lines - 1 do
        -- Display random stuff. For the sake of this trivial demo we are using basic Button() + SameLine()
        -- If you want to create your own time line for a real application you may be better off manipulating
        -- the cursor position yourself, aka using SetCursorPos/SetCursorScreenPos to position the widgets
        -- yourself. You may also want to use the lower-level ImDrawList API.
        local num_buttons = 10 + ((line % 2 == 1) and line * 9 or line * 3)
        local base_w = ImGui.GetFontSize() * 3
        for n = 0, num_buttons - 1 do
            if n > 0 then ImGui.SameLine() end
            ImGui.PushID(n + line * 1000)
            local label = (n % 15 == 0) and "FizzBuzz" or (n % 3 == 0) and "Fizz" or (n % 5 == 0) and "Buzz" or tostring(n)
            local hue = n * 0.05
            ImGui.PushStyleColor(ImGuiCol.Button, HSV(hue, 0.6, 0.6))
            ImGui.PushStyleColor(ImGuiCol.ButtonHovered, HSV(hue, 0.7, 0.7))
            ImGui.PushStyleColor(ImGuiCol.ButtonActive, HSV(hue, 0.8, 0.8))
            ImGui.Button(label, ImVec2(base_w + math.sin(line + n) * base_w * 0.5, 0.0))
            ImGui.PopStyleColor(3)
            ImGui.PopID()
        end
    end
    local scroll_x = ImGui.GetScrollX()
    local scroll_max_x = ImGui.GetScrollMaxX()
    ImGui.EndChild()
    ImGui.PopStyleVar(2)
    local scroll_x_delta = 0.0
    ImGui.SmallButton("<<")
    if ImGui.IsItemActive() then
        scroll_x_delta = -ImGui.GetIO().DeltaTime * 1000.0
    end
    ImGui.SameLine()
    ImGui.Text("Scroll from code"); ImGui.SameLine()
    ImGui.SmallButton(">>")
    if ImGui.IsItemActive() then
        scroll_x_delta = ImGui.GetIO().DeltaTime * 1000.0
    end
    ImGui.SameLine()
    ImGui.Text("%.0f/%.0f", scroll_x, scroll_max_x)
    if scroll_x_delta ~= 0.0 then
        -- Demonstrate a trick: you can use Begin to set yourself in the context of another window
        -- (here we are already out of your child window)
        BeginChild("scrolling")
        ImGui.SetScrollX(ImGui.GetScrollX() + scroll_x_delta)
        ImGui.EndChild()
    end
    ImGui.Spacing()

    _, SL.show_horizontal_contents_size_demo_window = ImGui.Checkbox("Show Horizontal contents size demo window", SL.show_horizontal_contents_size_demo_window)

    if SL.show_horizontal_contents_size_demo_window then
        DemoWindowLayout_HorizontalContentsSizeWindow()
    end
end

local function DemoWindowLayout_TextClipping()
    IMGUI_DEMO_MARKER("Layout/Text Clipping")
    if SL.clip_size == nil then SL.clip_size = { 100.0, 100.0 }; SL.clip_offset = ImVec2(30.0, 30.0) end
    ImGui.DragFloat2("size", SL.clip_size, 0.5, 1.0, 200.0, "%.0f")
    ImGui.TextWrapped("(Click and drag to scroll)")

    DemoHelpMarker(
        "(Left) Using ImGui::PushClipRect():\n" ..
        "Will alter ImGui hit-testing logic + ImDrawList rendering.\n" ..
        "(use this if you want your clipping rectangle to affect interactions)\n\n" ..
        "(Center) Using ImDrawList::PushClipRect():\n" ..
        "Will alter ImDrawList rendering only.\n" ..
        "(use this as a shortcut if you are only using ImDrawList calls)\n\n" ..
        "(Right) Using ImDrawList::AddText() with a fine ClipRect:\n" ..
        "Will alter only this specific ImDrawList::AddText() rendering.\n" ..
        "This is often used internally to avoid altering the clipping rectangle and minimize draw calls.")

    local size = ImVec2(SL.clip_size[1], SL.clip_size[2])
    local offset = SL.clip_offset
    for n = 0, 2 do repeat
        if n > 0 then
            ImGui.SameLine()
        end

        ImGui.PushID(n)
        ImGui.InvisibleButton("##canvas", size)
        if ImGui.IsItemActive() and ImGui.IsMouseDragging(ImGuiMouseButton.Left) then
            offset.x = offset.x + ImGui.GetIO().MouseDelta.x
            offset.y = offset.y + ImGui.GetIO().MouseDelta.y
        end
        ImGui.PopID()
        if not ImGui.IsItemVisible() then -- Skip rendering as ImDrawList elements are not clipped.
            break
        end

        local p0 = ImGui.GetItemRectMin()
        local p1 = ImGui.GetItemRectMax()
        local text_str = "Line 1 hello\nLine 2 clip me!"
        local text_pos = ImVec2(p0.x + offset.x, p0.y + offset.y)
        local draw_list = ImGui.GetWindowDrawList()
        if n == 0 then
            ImGui.PushClipRect(p0, p1, true)
            draw_list:AddRectFilled(p0, p1, IM_COL32(90, 90, 120, 255))
            draw_list:AddText(text_pos, IM_COL32_WHITE, text_str)
            ImGui.PopClipRect()
        elseif n == 1 then
            draw_list:PushClipRect(p0, p1, true)
            draw_list:AddRectFilled(p0, p1, IM_COL32(90, 90, 120, 255))
            draw_list:AddText(text_pos, IM_COL32_WHITE, text_str)
            draw_list:PopClipRect()
        else
            local clip_rect = ImVec4(p0.x, p0.y, p1.x, p1.y) -- AddText() takes a ImVec4 here so let's convert.
            draw_list:AddRectFilled(p0, p1, IM_COL32(90, 90, 120, 255))
            draw_list:AddText(ImGui.GetFont(), ImGui.GetFontSize(), text_pos, IM_COL32_WHITE, text_str, 1, #text_str + 1, 0.0, clip_rect)
        end
    until true end
end

local function DemoWindowLayout_OverlapMode()
    IMGUI_DEMO_MARKER("Layout/Overlap Mode")
    DemoHelpMarker(
        "Hit-testing is by default performed in item submission order, which generally is perceived as 'back-to-front'.\n\n" ..
        "By using SetNextItemAllowOverlap() you can notify that an item may be overlapped by another. " ..
        "Doing so alters the hovering logic: items using AllowOverlap mode requires an extra frame to accept hovered state.")
    _, SL.enable_allow_overlap = ImGui.Checkbox("Enable AllowOverlap", SL.enable_allow_overlap)

    local button1_pos = ImGui.GetCursorScreenPos()
    local button2_pos = ImVec2(button1_pos.x + 50.0, button1_pos.y + 50.0)
    if SL.enable_allow_overlap then
        ImGui.SetNextItemAllowOverlap()
    end
    ImGui.Button("Button 1", ImVec2(80, 80))
    ImGui.SetCursorScreenPos(button2_pos)
    ImGui.Button("Button 2", ImVec2(80, 80))

    -- This is typically used with width-spanning items.
    -- (note that Selectable() has a dedicated flag ImGuiSelectableFlags.AllowOverlap, which is a shortcut
    -- for using SetNextItemAllowOverlap(). For demo purpose we use SetNextItemAllowOverlap() here.)
    if SL.enable_allow_overlap then
        ImGui.SetNextItemAllowOverlap()
    end
    ImGui.Selectable("Some Selectable", false)
    ImGui.SameLine()
    ImGui.SmallButton("++")
end

function DemoWindowLayout()
    if not ImGui.CollapsingHeader("Layout & Scrolling") then
        return
    end
    if ImGui.TreeNode("Child windows") then DemoWindowLayout_ChildWindows(); ImGui.TreePop() end
    if ImGui.TreeNode("Widgets Width") then DemoWindowLayout_WidgetsWidth(); ImGui.TreePop() end
    if ImGui.TreeNode("Basic Horizontal Layout") then DemoWindowLayout_BasicHorizontal(); ImGui.TreePop() end
    if ImGui.TreeNode("Groups") then DemoWindowLayout_Groups(); ImGui.TreePop() end
    if ImGui.TreeNode("Text Baseline Alignment") then DemoWindowLayout_TextBaseline(); ImGui.TreePop() end
    if ImGui.TreeNode("Scrolling") then DemoWindowLayout_Scrolling(); ImGui.TreePop() end
    if ImGui.TreeNode("Text Clipping") then DemoWindowLayout_TextClipping(); ImGui.TreePop() end
    if ImGui.TreeNode("Overlap Mode") then DemoWindowLayout_OverlapMode(); ImGui.TreePop() end
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowPopups()
-------------------------------------------------------------------------------

local SP = {
    selected_fish = -1, toggles = { true, false, false, false, false },
    ctx_selected = -1, value = 0.5, name = nil,
    dont_ask_me_next_time = false, item = 1, color = { 0.4, 0.7, 0.0, 0.5 },
}

local function DemoWindowPopups_Popups()
    IMGUI_DEMO_MARKER("Popups/Popups")
    ImGui.TextWrapped(
        "When a popup is active, it inhibits interacting with windows that are behind the popup. " ..
        "Clicking outside the popup closes it.")

    local names = { "Bream", "Haddock", "Mackerel", "Pollock", "Tilefish" }
    local toggles = SP.toggles

    -- Simple selection popup (if you want to show the current selection inside the Button itself,
    -- you may want to build a string using the "###" operator to preserve a constant ID with a variable label)
    if ImGui.Button("Select..") then
        ImGui.OpenPopup("my_select_popup")
    end
    ImGui.SameLine()
    ImGui.TextUnformatted(SP.selected_fish == -1 and "<None>" or names[SP.selected_fish + 1])
    if ImGui.BeginPopup("my_select_popup") then
        ImGui.SeparatorText("Aquarium")
        for i = 1, #names do
            if ImGui.Selectable(names[i]) then
                SP.selected_fish = i - 1
            end
        end
        ImGui.EndPopup()
    end

    -- Showing a menu with toggles
    if ImGui.Button("Toggle..") then
        ImGui.OpenPopup("my_toggle_popup")
    end
    if ImGui.BeginPopup("my_toggle_popup") then
        for i = 1, #names do
            _, toggles[i] = ImGui.MenuItem(names[i], "", toggles[i])
        end
        if ImGui.BeginMenu("Sub-menu") then
            ImGui.MenuItem("Click me")
            ImGui.EndMenu()
        end

        ImGui.Separator()
        ImGui.Text("Tooltip here")
        ImGui.SetItemTooltip("I am a tooltip over a popup")

        if ImGui.Button("Stacked Popup") then
            ImGui.OpenPopup("another popup")
        end
        if ImGui.BeginPopup("another popup") then
            for i = 1, #names do
                _, toggles[i] = ImGui.MenuItem(names[i], "", toggles[i])
            end
            if ImGui.BeginMenu("Sub-menu") then
                ImGui.MenuItem("Click me")
                if ImGui.Button("Stacked Popup") then
                    ImGui.OpenPopup("another popup")
                end
                if ImGui.BeginPopup("another popup") then
                    ImGui.Text("I am the last one here.")
                    ImGui.EndPopup()
                end
                ImGui.EndMenu()
            end
            ImGui.EndPopup()
        end
        ImGui.EndPopup()
    end

    -- Call the more complete ShowExampleMenuFile which we use in various places of this demo
    if ImGui.Button("With a menu..") then
        ImGui.OpenPopup("my_file_popup")
    end
    if ImGui.BeginPopup("my_file_popup", ImGuiWindowFlags.MenuBar) then
        if ImGui.BeginMenuBar() then
            if ImGui.BeginMenu("File") then
                DemoMenuFile()
                ImGui.EndMenu()
            end
            if ImGui.BeginMenu("Edit") then
                ImGui.MenuItem("Dummy")
                ImGui.EndMenu()
            end
            ImGui.EndMenuBar()
        end
        ImGui.Text("Hello from popup!")
        ImGui.Button("This is a dummy button..")
        ImGui.EndPopup()
    end
end

local function DemoWindowPopups_ContextMenus()
    IMGUI_DEMO_MARKER("Popups/Context menus")
    DemoHelpMarker("\"Context\" functions are simple helpers to associate a Popup to a given Item or Window identifier.")

    -- BeginPopupContextItem() is a helper to provide common/simple popup behavior of essentially doing:
    --     if id == 0 then
    --         id = GetItemID() -- Use last item id
    --     end
    --     if IsItemHovered() and IsMouseReleased(ImGuiMouseButton.Right) then
    --         OpenPopup(id)
    --     end
    --     return BeginPopup(id)
    -- For advanced uses you may want to replicate and customize this code.
    -- See more details in BeginPopupContextItem().

    -- Example 1
    -- When used after an item that has an ID (e.g. Button), we can skip providing an ID to BeginPopupContextItem(),
    -- and BeginPopupContextItem() will use the last item ID as the popup ID.
    do
        local names = { "Label1", "Label2", "Label3", "Label4", "Label5" }
        for n = 0, 4 do
            if ImGui.Selectable(names[n + 1], SP.ctx_selected == n) then
                SP.ctx_selected = n
            end
            if ImGui.BeginPopupContextItem() then -- <-- use last item id as popup id
                SP.ctx_selected = n
                ImGui.Text("This is a popup for \"%s\"!", names[n + 1])
                if ImGui.Button("Close") then
                    ImGui.CloseCurrentPopup()
                end
                ImGui.EndPopup()
            end
            ImGui.SetItemTooltip("Right-click to open popup")
        end
    end

    -- Example 2
    -- Popup on a Text() element which doesn't have an identifier: we need to provide an identifier to BeginPopupContextItem().
    -- Using an explicit identifier is also convenient if you want to activate the popups from different locations.
    do
        DemoHelpMarker("Text() elements don't have stable identifiers so we need to provide one.")
        ImGui.Text("Value = %.3f <-- (1) right-click this text", SP.value)
        if ImGui.BeginPopupContextItem("my popup") then
            if ImGui.Selectable("Set to zero") then SP.value = 0.0 end
            if ImGui.Selectable("Set to PI") then SP.value = 3.1415 end
            ImGui.SetNextItemWidth(-FLT_MIN)
            SP.value = ImGui.DragFloat("##Value", SP.value, 0.1, 0.0, 0.0)
            ImGui.EndPopup()
        end

        -- We can also use OpenPopupOnItemClick() to toggle the visibility of a given popup.
        -- Here we make it that right-clicking this other text element opens the same popup as above.
        -- The popup itself will be submitted by the code above.
        ImGui.Text("(2) Or right-click this text")
        ImGui.OpenPopupOnItemClick("my popup", ImGuiPopupFlags.MouseButtonRight)

        -- Back to square one: manually open the same popup.
        if ImGui.Button("(3) Or click this button") then
            ImGui.OpenPopup("my popup")
        end
    end

    -- Example 3
    -- When using BeginPopupContextItem() with an implicit identifier (nil == use last item ID),
    -- we need to make sure your item identifier is stable.
    -- In this example we showcase altering the item label while preserving its identifier, using the ### operator (see FAQ).
    do
        DemoHelpMarker("Showcase using a popup ID linked to item ID, with the item having a changing label + stable ID using the ### operator.")
        if SP.name == nil then SP.name = Buf("Label1", 32) end
        local buf = string.format("Button: %s###Button", BufStr(SP.name)) -- ### operator override ID ignoring the preceding label
        ImGui.Button(buf)
        if ImGui.BeginPopupContextItem() then
            ImGui.Text("Edit name:")
            ImGui.InputText("##edit", SP.name, 32)
            if ImGui.Button("Close") then
                ImGui.CloseCurrentPopup()
            end
            ImGui.EndPopup()
        end
        ImGui.SameLine(); ImGui.Text("(<-- right-click here)")
    end
end

local function DemoWindowPopups_Modals()
    IMGUI_DEMO_MARKER("Popups/Modals")
    ImGui.TextWrapped("Modal windows are like popups but the user cannot close them by clicking outside.")

    if ImGui.Button("Delete..") then
        ImGui.OpenPopup("Delete?")
    end

    -- Always center this window when appearing
    local center = ImGui.GetMainViewport():GetCenter()
    ImGui.SetNextWindowPos(center, ImGuiCond.Appearing, ImVec2(0.5, 0.5))

    if ImGui.BeginPopupModal("Delete?", nil, ImGuiWindowFlags.AlwaysAutoResize) then
        ImGui.Text("All those beautiful files will be deleted.\nThis operation cannot be undone!")
        ImGui.Separator()

        -- local unused_i = 0
        -- unused_i = ImGui.Combo("Combo", unused_i, "Delete\0Delete harder\0")

        ImGui.PushStyleVar(ImGuiStyleVar.FramePadding, ImVec2(0, 0))
        _, SP.dont_ask_me_next_time = ImGui.Checkbox("Don't ask me next time", SP.dont_ask_me_next_time)
        ImGui.PopStyleVar()

        if ImGui.Button("OK", ImVec2(120, 0)) then ImGui.CloseCurrentPopup() end
        ImGui.SetItemDefaultFocus()
        ImGui.SameLine()
        if ImGui.Button("Cancel", ImVec2(120, 0)) then ImGui.CloseCurrentPopup() end
        ImGui.EndPopup()
    end

    if ImGui.Button("Stacked modals..") then
        ImGui.OpenPopup("Stacked 1")
    end
    if ImGui.BeginPopupModal("Stacked 1", nil, ImGuiWindowFlags.MenuBar) then
        if ImGui.BeginMenuBar() then
            if ImGui.BeginMenu("File") then
                if ImGui.MenuItem("Some menu item") then end
                ImGui.EndMenu()
            end
            ImGui.EndMenuBar()
        end
        ImGui.Text("Hello from Stacked The First\nUsing style.Colors[ImGuiCol_ModalWindowDimBg] behind it.")

        -- Testing behavior of widgets stacking their own regular popups over the modal.
        if ImGui.Combo then
            SP.item = ImGui.Combo("Combo", SP.item, { "aaaa", "bbbb", "cccc", "dddd", "eeee" }, 5)
        else
            NotPorted("Combo")
        end
        ImGui.ColorEdit4("Color", SP.color)

        if ImGui.Button("Add another modal..") then
            ImGui.OpenPopup("Stacked 2")
        end

        -- Also demonstrate passing a p_open bool to BeginPopupModal(), this will create a regular close button which
        -- will close the popup. Note that the visibility state of popups is owned by imgui, so the input value
        -- of the bool actually doesn't matter here.
        local unused_open = true
        if ImGui.BeginPopupModal("Stacked 2", unused_open) then
            ImGui.Text("Hello from Stacked The Second!")
            ImGui.ColorEdit4("Color", SP.color) -- Allow opening another nested popup
            if ImGui.Button("Close") then
                ImGui.CloseCurrentPopup()
            end
            ImGui.EndPopup()
        end

        if ImGui.Button("Close") then
            ImGui.CloseCurrentPopup()
        end
        ImGui.EndPopup()
    end
end

function DemoWindowPopups()
    if not ImGui.CollapsingHeader("Popups & Modal windows") then
        return
    end

    -- The properties of popups windows are:
    -- - They block normal mouse hovering detection outside them. (*)
    -- - Unless modal, they can be closed by clicking anywhere outside them, or by pressing ESCAPE.
    -- - Their visibility state (~bool) is held internally by Dear ImGui instead of being held by the programmer as
    --   we are used to with regular Begin() calls. User can manipulate the visibility state by calling OpenPopup().
    -- (*) One can use IsItemHovered(ImGuiHoveredFlags.AllowWhenBlockedByPopup) to bypass it and detect hovering even
    --     when normally blocked by a popup.
    -- Those three properties are connected. The library needs to hold their visibility state BECAUSE it can close
    -- popups at any time.

    -- Typical use for regular windows:
    --   local my_tool_is_active = false; if ImGui.Button("Open") then my_tool_is_active = true end; [...] if my_tool_is_active then my_tool_is_active, visible = ImGui.Begin("My Tool", my_tool_is_active); [...] ImGui.End() end
    -- Typical use for popups:
    --   if ImGui.Button("Open") then ImGui.OpenPopup("MyPopup") end; if ImGui.BeginPopup("MyPopup") then [...] ImGui.EndPopup() end

    -- With popups we have to go through a library call (here OpenPopup) to manipulate the visibility state.
    -- This may be a bit confusing at first but it should quickly make sense. Follow on the examples below.

    if ImGui.TreeNode("Popups") then DemoWindowPopups_Popups(); ImGui.TreePop() end
    if ImGui.TreeNode("Context menus") then DemoWindowPopups_ContextMenus(); ImGui.TreePop() end
    if ImGui.TreeNode("Modals") then
        if ImGui.BeginPopupModal then DemoWindowPopups_Modals() else NotPorted("BeginPopupModal") end
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Menus inside a regular window") then
        IMGUI_DEMO_MARKER("Popups/Menus inside a regular window")
        ImGui.TextWrapped("Below we are testing adding menu items to a regular window. It's rather unusual but should work!")
        ImGui.Separator()

        ImGui.MenuItem("Menu item", "Ctrl+M")
        if ImGui.BeginMenu("Menu inside a regular window") then
            DemoMenuFile()
            ImGui.EndMenu()
        end
        ImGui.Separator()
        ImGui.TreePop()
    end
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowTables()
-------------------------------------------------------------------------------

-- Dummy data structure that we use for the Table demo.
-- We are passing our own identifier to TableSetupColumn() to facilitate identifying columns in the sorting code.
-- This identifier will be passed down into ImGuiTableSortSpec::ColumnUserID.
-- But it is possible to omit the user id parameter of TableSetupColumn() and just use the column index instead! (ImGuiTableSortSpec::ColumnIndex)
-- If you don't use sorting, you will generally never care about giving column an ID!
-- MyItemColumnID
local MyItemColumnID_ID, MyItemColumnID_Name, MyItemColumnID_Action, MyItemColumnID_Quantity, MyItemColumnID_Description = 0, 1, 2, 3, 4

local function MyItem(id, name, quantity) return { ID = id, Name = name, Quantity = quantity } end

--- Sort a Lua array (1-based) of MyItem with ImGuiTableSortSpecs (Specs is 1-based array or ImVector)
local function MyItem_SortWithSortSpecs(sort_specs, items, items_count)
    if items_count <= 1 then return end
    local specs = sort_specs.Specs
    local function get_spec(n) -- n: 0-based
        if specs.Data then return specs.Data[n + 1] end
        return specs[n + 1]
    end
    local function cmp(a, b) -- returns <0, 0, >0
        for n = 0, sort_specs.SpecsCount - 1 do
            -- Here we identify columns using the ColumnUserID value that we ourselves passed to TableSetupColumn()
            -- We could also choose to identify columns based on their index (sort_spec.ColumnIndex), which is simpler!
            local sort_spec = get_spec(n)
            local delta = 0
            local uid = sort_spec.ColumnUserID
            if uid == MyItemColumnID_ID then delta = a.ID - b.ID
            elseif uid == MyItemColumnID_Name then delta = (a.Name < b.Name) and -1 or (a.Name > b.Name) and 1 or 0
            elseif uid == MyItemColumnID_Quantity then delta = a.Quantity - b.Quantity
            elseif uid == MyItemColumnID_Description then delta = (a.Name < b.Name) and -1 or (a.Name > b.Name) and 1 or 0
            else IM_ASSERT(false) end
            if delta > 0 then
                return (sort_spec.SortDirection == ImGuiSortDirection.Ascending) and 1 or -1
            end
            if delta < 0 then
                return (sort_spec.SortDirection == ImGuiSortDirection.Ascending) and -1 or 1
            end
        end

        -- table.sort() is instable so always return a way to differentiate items.
        -- Your own compare function may want to avoid fallback on implicit sort specs.
        -- e.g. a Name compare if it wasn't already part of the sort specs.
        return a.ID - b.ID
    end
    local arr = items.Data or items
    if items.Data then
        -- ImVector: sort only the used range
        local tmp = {}
        for i = 1, items_count do tmp[i] = arr[i] end
        table.sort(tmp, function(a, b) return cmp(a, b) < 0 end)
        for i = 1, items_count do arr[i] = tmp[i] end
    else
        table.sort(arr, function(a, b) return cmp(a, b) < 0 end)
    end
end

-- Make the UI compact because there are so many fields
local function PushStyleCompact()
    local style = ImGui.GetStyle()
    ImGui.PushStyleVarY(ImGuiStyleVar.FramePadding, math.floor(style.FramePadding.y * 0.60))
    ImGui.PushStyleVarY(ImGuiStyleVar.ItemSpacing, math.floor(style.ItemSpacing.y * 0.60))
end

local function PopStyleCompact()
    ImGui.PopStyleVar(2)
end

local table_sizing_policies = nil
-- Show a combo box with a choice of sizing policies
local function EditTableSizingFlags(flags)
    if table_sizing_policies == nil then
        table_sizing_policies = {
            { Value = ImGuiTableFlags.None,              Name = "Default",                           Tooltip = "Use default sizing policy:\n- ImGuiTableFlags_SizingFixedFit if ScrollX is on or if host window has ImGuiWindowFlags_AlwaysAutoResize.\n- ImGuiTableFlags_SizingStretchSame otherwise." },
            { Value = ImGuiTableFlags.SizingFixedFit,    Name = "ImGuiTableFlags_SizingFixedFit",    Tooltip = "Columns default to _WidthFixed (if resizable) or _WidthAuto (if not resizable), matching contents width." },
            { Value = ImGuiTableFlags.SizingFixedSame,   Name = "ImGuiTableFlags_SizingFixedSame",   Tooltip = "Columns are all the same width, matching the maximum contents width.\nImplicitly disable ImGuiTableFlags_Resizable and enable ImGuiTableFlags_NoKeepColumnsVisible." },
            { Value = ImGuiTableFlags.SizingStretchProp, Name = "ImGuiTableFlags_SizingStretchProp", Tooltip = "Columns default to _WidthStretch with weights proportional to their widths." },
            { Value = ImGuiTableFlags.SizingStretchSame, Name = "ImGuiTableFlags_SizingStretchSame", Tooltip = "Columns default to _WidthStretch with same weights." },
        }
    end
    local policies = table_sizing_policies
    local idx = 1
    while idx <= #policies do
        if policies[idx].Value == bit32.band(flags, ImGuiTableFlags.SizingMask_) then break end
        idx = idx + 1
    end
    local preview_text = (idx <= #policies) and (idx > 1 and string.sub(policies[idx].Name, #"ImGuiTableFlags" + 1) or policies[idx].Name) or ""
    if ImGui.BeginCombo("Sizing Policy", preview_text) then
        for n = 1, #policies do
            if ImGui.Selectable(policies[n].Name, idx == n) then
                flags = bit32.bor(bit32.band(flags, bit32.bnot(ImGuiTableFlags.SizingMask_)), policies[n].Value)
            end
        end
        ImGui.EndCombo()
    end
    ImGui.SameLine()
    ImGui.TextDisabled("(?)")
    if ImGui.BeginItemTooltip() then
        ImGui.PushTextWrapPos(ImGui.GetFontSize() * 50.0)
        for m = 1, #policies do
            ImGui.Separator()
            ImGui.Text("%s:", policies[m].Name)
            ImGui.Separator()
            ImGui.SetCursorPosX(ImGui.GetCursorPosX() + ImGui.GetStyle().IndentSpacing * 0.5)
            ImGui.TextUnformatted(policies[m].Tooltip)
        end
        ImGui.PopTextWrapPos()
        ImGui.EndTooltip()
    end
    return flags
end

local function EditTableColumnsFlags(f)
    local p
    local F = ImGuiTableColumnFlags
    _, f = ImGui.CheckboxFlags("_Disabled", f, F.Disabled); ImGui.SameLine(); DemoHelpMarker("Master disable flag (also hide from context menu)")
    _, f = ImGui.CheckboxFlags("_DefaultHide", f, F.DefaultHide)
    _, f = ImGui.CheckboxFlags("_DefaultSort", f, F.DefaultSort)
    p, f = ImGui.CheckboxFlags("_WidthStretch", f, F.WidthStretch)
    if p then f = bit32.band(f, bit32.bnot(bit32.bxor(F.WidthMask_, F.WidthStretch))) end
    p, f = ImGui.CheckboxFlags("_WidthFixed", f, F.WidthFixed)
    if p then f = bit32.band(f, bit32.bnot(bit32.bxor(F.WidthMask_, F.WidthFixed))) end
    _, f = ImGui.CheckboxFlags("_NoResize", f, F.NoResize)
    _, f = ImGui.CheckboxFlags("_NoReorder", f, F.NoReorder)
    _, f = ImGui.CheckboxFlags("_NoHide", f, F.NoHide)
    _, f = ImGui.CheckboxFlags("_NoClip", f, F.NoClip)
    _, f = ImGui.CheckboxFlags("_NoSort", f, F.NoSort)
    _, f = ImGui.CheckboxFlags("_NoSortAscending", f, F.NoSortAscending)
    _, f = ImGui.CheckboxFlags("_NoSortDescending", f, F.NoSortDescending)
    _, f = ImGui.CheckboxFlags("_NoHeaderLabel", f, F.NoHeaderLabel)
    _, f = ImGui.CheckboxFlags("_NoHeaderWidth", f, F.NoHeaderWidth)
    _, f = ImGui.CheckboxFlags("_PreferSortAscending", f, F.PreferSortAscending)
    _, f = ImGui.CheckboxFlags("_PreferSortDescending", f, F.PreferSortDescending)
    _, f = ImGui.CheckboxFlags("_IndentEnable", f, F.IndentEnable); ImGui.SameLine(); DemoHelpMarker("Default for column 0")
    _, f = ImGui.CheckboxFlags("_IndentDisable", f, F.IndentDisable); ImGui.SameLine(); DemoHelpMarker("Default for column >0")
    _, f = ImGui.CheckboxFlags("_AngledHeader", f, F.AngledHeader)
    return f
end

local function ShowTableColumnsStatusFlags(flags)
    ImGui.CheckboxFlags("_IsEnabled", flags, ImGuiTableColumnFlags.IsEnabled)
    ImGui.CheckboxFlags("_IsVisible", flags, ImGuiTableColumnFlags.IsVisible)
    ImGui.CheckboxFlags("_IsSorted", flags, ImGuiTableColumnFlags.IsSorted)
    ImGui.CheckboxFlags("_IsHovered", flags, ImGuiTableColumnFlags.IsHovered)
end

local function bor(...) return bit32.bor(...) end
local TF = setmetatable({}, { __index = function(_, k) return ImGuiTableFlags[k] end })

local ST = {} -- statics for DemoWindowTables (one sub-table per section)
-- Using those as a base value to create width/height that are factor of the size of our font
local TEXT_BASE_WIDTH, TEXT_BASE_HEIGHT = 0, 0

local function Tables_Basic()
    IMGUI_DEMO_MARKER("Tables/Basic")
    -- Here we will showcase three different ways to output a table.
    -- They are very simple variations of a same thing!

    -- [Method 1] Using TableNextRow() to create a new row, and TableSetColumnIndex() to select the column.
    -- In many situations, this is the most flexible and easy to use pattern.
    DemoHelpMarker("Using TableNextRow() + calling TableSetColumnIndex() _before_ each cell, in a loop.")
    if ImGui.BeginTable("table1", 3) then
        for row = 0, 3 do
            ImGui.TableNextRow()
            for column = 0, 2 do
                ImGui.TableSetColumnIndex(column)
                ImGui.Text("Row %d Column %d", row, column)
            end
        end
        ImGui.EndTable()
    end

    -- [Method 2] Using TableNextColumn() called multiple times, instead of using a for loop + TableSetColumnIndex().
    -- This is generally more convenient when you have code manually submitting the contents of each column.
    DemoHelpMarker("Using TableNextRow() + calling TableNextColumn() _before_ each cell, manually.")
    if ImGui.BeginTable("table2", 3) then
        for row = 0, 3 do
            ImGui.TableNextRow()
            ImGui.TableNextColumn()
            ImGui.Text("Row %d", row)
            ImGui.TableNextColumn()
            ImGui.Text("Some contents")
            ImGui.TableNextColumn()
            ImGui.Text("123.456")
        end
        ImGui.EndTable()
    end

    -- [Method 3] We call TableNextColumn() _before_ each cell. We never call TableNextRow(),
    -- as TableNextColumn() will automatically wrap around and create new rows as needed.
    -- This is generally more convenient when your cells all contains the same type of data.
    DemoHelpMarker(
        "Only using TableNextColumn(), which tends to be convenient for tables where every cell contains " ..
        "the same type of contents.\n This is also more similar to the old NextColumn() function of the " ..
        "Columns API, and provided to facilitate the Columns->Tables API transition.")
    if ImGui.BeginTable("table3", 3) then
        for item = 0, 13 do
            ImGui.TableNextColumn()
            ImGui.Text("Item %d", item)
        end
        ImGui.EndTable()
    end
end

local function Tables_BordersBackground()
    IMGUI_DEMO_MARKER("Tables/Borders, background")
    -- Expose a few Borders related flags interactively
    local CT_Text, CT_FillButton = 0, 1
    local s = ST.borders
    if s == nil then s = { flags = bor(TF.Borders, TF.RowBg), display_headers = false, contents_type = CT_Text }; ST.borders = s end

    PushStyleCompact()
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_RowBg", s.flags, TF.RowBg)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Borders", s.flags, TF.Borders)
    ImGui.SameLine(); DemoHelpMarker("ImGuiTableFlags_Borders\n = ImGuiTableFlags_BordersInnerV\n | ImGuiTableFlags_BordersOuterV\n | ImGuiTableFlags_BordersInnerH\n | ImGuiTableFlags_BordersOuterH")
    ImGui.Indent()

    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersH", s.flags, TF.BordersH)
    ImGui.Indent()
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersOuterH", s.flags, TF.BordersOuterH)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersInnerH", s.flags, TF.BordersInnerH)
    ImGui.Unindent()

    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersV", s.flags, TF.BordersV)
    ImGui.Indent()
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersOuterV", s.flags, TF.BordersOuterV)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersInnerV", s.flags, TF.BordersInnerV)
    ImGui.Unindent()

    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersOuter", s.flags, TF.BordersOuter)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersInner", s.flags, TF.BordersInner)
    ImGui.Unindent()

    ImGui.AlignTextToFramePadding(); ImGui.Text("Cell contents:")
    ImGui.SameLine(); _, s.contents_type = ImGui.RadioButton("Text", s.contents_type, CT_Text)
    ImGui.SameLine(); _, s.contents_type = ImGui.RadioButton("FillButton", s.contents_type, CT_FillButton)
    _, s.display_headers = ImGui.Checkbox("Display headers", s.display_headers)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoBordersInBody", s.flags, TF.NoBordersInBody); ImGui.SameLine(); DemoHelpMarker("Disable vertical borders in columns Body (borders will always appear in Headers)")
    PopStyleCompact()

    if ImGui.BeginTable("table1", 3, s.flags) then
        -- Display headers so we can inspect their interaction with borders
        -- (Headers are not the main purpose of this section of the demo, so we are not elaborating on them now. See other sections for details)
        if s.display_headers then
            ImGui.TableSetupColumn("One")
            ImGui.TableSetupColumn("Two")
            ImGui.TableSetupColumn("Three")
            ImGui.TableHeadersRow()
        end

        for row = 0, 4 do
            ImGui.TableNextRow()
            for column = 0, 2 do
                ImGui.TableSetColumnIndex(column)
                local buf = string.format("Hello %d,%d", column, row)
                if s.contents_type == CT_Text then
                    ImGui.TextUnformatted(buf)
                elseif s.contents_type == CT_FillButton then
                    ImGui.Button(buf, ImVec2(-FLT_MIN, 0.0))
                end
            end
        end
        ImGui.EndTable()
    end
end

local function Tables_HelloGrid(id, flags, rows, cols, fmt)
    if ImGui.BeginTable(id, cols, flags) then
        for row = 0, rows - 1 do
            ImGui.TableNextRow()
            for column = 0, cols - 1 do
                ImGui.TableSetColumnIndex(column)
                ImGui.Text(fmt or "Hello %d,%d", column, row)
            end
        end
        ImGui.EndTable()
    end
end

local function Tables_ResizableStretch()
    IMGUI_DEMO_MARKER("Tables/Resizable, stretch")
    -- By default, if we don't enable ScrollX the sizing policy for each column is "Stretch"
    -- All columns maintain a sizing weight, and they will occupy all available width.
    local s = ST.rstretch
    if s == nil then s = { flags = bor(TF.SizingStretchSame, TF.Resizable, TF.BordersOuter, TF.BordersV, TF.ContextMenuInBody) }; ST.rstretch = s end
    PushStyleCompact()
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Resizable", s.flags, TF.Resizable)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersV", s.flags, TF.BordersV)
    ImGui.SameLine(); DemoHelpMarker(
        "Using the _Resizable flag automatically enables the _BordersInnerV flag as well, " ..
        "this is why the resize borders are still showing when unchecking this.")
    PopStyleCompact()

    Tables_HelloGrid("table1", s.flags, 5, 3)
end

local function Tables_ResizableFixed()
    IMGUI_DEMO_MARKER("Tables/Resizable, fixed")
    -- Here we use ImGuiTableFlags.SizingFixedFit (even though _ScrollX is not set)
    -- So columns will adopt the "Fixed" policy and will maintain a fixed width regardless of the whole available width (unless table is small)
    -- If there is not enough available width to fit all columns, they will however be resized down.
    -- FIXME-TABLE: Providing a stretch-on-init would make sense especially for tables which don't have saved settings
    DemoHelpMarker(
        "Using _Resizable + _SizingFixedFit flags.\n" ..
        "Fixed-width columns generally makes more sense if you want to use horizontal scrolling.\n\n" ..
        "Double-click a column border to auto-fit the column to its contents.")
    PushStyleCompact()
    local s = ST.rfixed
    if s == nil then s = { flags = bor(TF.SizingFixedFit, TF.Resizable, TF.BordersOuter, TF.BordersV, TF.ContextMenuInBody) }; ST.rfixed = s end
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoHostExtendX", s.flags, TF.NoHostExtendX)
    PopStyleCompact()

    Tables_HelloGrid("table1", s.flags, 5, 3)
end

local function Tables_ResizableMixed()
    IMGUI_DEMO_MARKER("Tables/Resizable, mixed")
    DemoHelpMarker(
        "Using TableSetupColumn() to alter resizing policy on a per-column basis.\n\n" ..
        "When combining Fixed and Stretch columns, generally you only want one, maybe two trailing columns to use _WidthStretch.")
    local flags = bor(TF.SizingFixedFit, TF.RowBg, TF.Borders, TF.Resizable, TF.Reorderable, TF.Hideable)
    local CF = ImGuiTableColumnFlags

    if ImGui.BeginTable("table1", 3, flags) then
        ImGui.TableSetupColumn("AAA", CF.WidthFixed)
        ImGui.TableSetupColumn("BBB", CF.WidthFixed)
        ImGui.TableSetupColumn("CCC", CF.WidthStretch)
        ImGui.TableHeadersRow()
        for row = 0, 4 do
            ImGui.TableNextRow()
            for column = 0, 2 do
                ImGui.TableSetColumnIndex(column)
                ImGui.Text("%s %d,%d", (column == 2) and "Stretch" or "Fixed", column, row)
            end
        end
        ImGui.EndTable()
    end
    if ImGui.BeginTable("table2", 6, flags) then
        ImGui.TableSetupColumn("AAA", CF.WidthFixed)
        ImGui.TableSetupColumn("BBB", CF.WidthFixed)
        ImGui.TableSetupColumn("CCC", bor(CF.WidthFixed, CF.DefaultHide))
        ImGui.TableSetupColumn("DDD", CF.WidthStretch)
        ImGui.TableSetupColumn("EEE", CF.WidthStretch)
        ImGui.TableSetupColumn("FFF", bor(CF.WidthStretch, CF.DefaultHide))
        ImGui.TableHeadersRow()
        for row = 0, 4 do
            ImGui.TableNextRow()
            for column = 0, 5 do
                ImGui.TableSetColumnIndex(column)
                ImGui.Text("%s %d,%d", (column >= 3) and "Stretch" or "Fixed", column, row)
            end
        end
        ImGui.EndTable()
    end
end

local function Tables_Reorderable()
    IMGUI_DEMO_MARKER("Tables/Reorderable, hideable, with headers")
    DemoHelpMarker(
        "Click and drag column headers to reorder columns.\n\n" ..
        "Right-click on a header to open a context menu.")
    local s = ST.reorder
    if s == nil then s = { flags = bor(TF.Resizable, TF.Reorderable, TF.Hideable, TF.BordersOuter, TF.BordersV) }; ST.reorder = s end
    PushStyleCompact()
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Resizable", s.flags, TF.Resizable)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Reorderable", s.flags, TF.Reorderable)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Hideable", s.flags, TF.Hideable)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoBordersInBody", s.flags, TF.NoBordersInBody)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoBordersInBodyUntilResize", s.flags, TF.NoBordersInBodyUntilResize); ImGui.SameLine(); DemoHelpMarker("Disable vertical borders in columns Body until hovered for resize (borders will always appear in Headers)")
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_HighlightHoveredColumn", s.flags, TF.HighlightHoveredColumn)
    PopStyleCompact()

    if ImGui.BeginTable("table1", 3, s.flags) then
        -- Submit columns name with TableSetupColumn() and call TableHeadersRow() to create a row with a header in each column.
        -- (Later we will show how TableSetupColumn() has other uses, optional flags, sizing weight etc.)
        ImGui.TableSetupColumn("One")
        ImGui.TableSetupColumn("Two")
        ImGui.TableSetupColumn("Three")
        ImGui.TableHeadersRow()
        for row = 0, 5 do
            ImGui.TableNextRow()
            for column = 0, 2 do
                ImGui.TableSetColumnIndex(column)
                ImGui.Text("Hello %d,%d", column, row)
            end
        end
        ImGui.EndTable()
    end

    -- Use outer_size.x == 0.0f instead of default to make the table as tight as possible
    -- (only valid when no scrolling and no stretch column)
    if ImGui.BeginTable("table2", 3, bor(s.flags, TF.SizingFixedFit), ImVec2(0.0, 0.0)) then
        ImGui.TableSetupColumn("One")
        ImGui.TableSetupColumn("Two")
        ImGui.TableSetupColumn("Three")
        ImGui.TableHeadersRow()
        for row = 0, 5 do
            ImGui.TableNextRow()
            for column = 0, 2 do
                ImGui.TableSetColumnIndex(column)
                ImGui.Text("Fixed %d,%d", column, row)
            end
        end
        ImGui.EndTable()
    end
end

local function Tables_Padding()
    IMGUI_DEMO_MARKER("Tables/Padding")
    -- First example: showcase use of padding flags and effect of BorderOuterV/BorderInnerV on X padding.
    -- We don't expose BorderOuterH/BorderInnerH here because they have no effect on X padding.
    DemoHelpMarker(
        "We often want outer padding activated when any using features which makes the edges of a column visible:\n" ..
        "e.g.:\n" ..
        "- BorderOuterV\n" ..
        "- any form of row selection\n" ..
        "Because of this, activating BorderOuterV sets the default to PadOuterX. " ..
        "Using PadOuterX or NoPadOuterX you can override the default.\n\n" ..
        "Actual padding values are using style.CellPadding.\n\n" ..
        "In this demo we don't show horizontal borders to emphasize how they don't affect default horizontal padding.")

    local s = ST.padding
    if s == nil then
        s = { flags1 = TF.BordersV, show_headers = false, flags2 = bor(TF.Borders, TF.RowBg), cell_padding = ImVec2(0.0, 0.0),
              show_widget_frame_bg = true, text_bufs = {}, init = true } -- text_bufs: Mini text storage for 3x5 cells
        ST.padding = s
    end
    PushStyleCompact()
    _, s.flags1 = ImGui.CheckboxFlags("ImGuiTableFlags_PadOuterX", s.flags1, TF.PadOuterX)
    ImGui.SameLine(); DemoHelpMarker("Enable outer-most padding (default if ImGuiTableFlags_BordersOuterV is set)")
    _, s.flags1 = ImGui.CheckboxFlags("ImGuiTableFlags_NoPadOuterX", s.flags1, TF.NoPadOuterX)
    ImGui.SameLine(); DemoHelpMarker("Disable outer-most padding (default if ImGuiTableFlags_BordersOuterV is not set)")
    _, s.flags1 = ImGui.CheckboxFlags("ImGuiTableFlags_NoPadInnerX", s.flags1, TF.NoPadInnerX)
    ImGui.SameLine(); DemoHelpMarker("Disable inner padding between columns (double inner padding if BordersOuterV is on, single inner padding if BordersOuterV is off)")
    _, s.flags1 = ImGui.CheckboxFlags("ImGuiTableFlags_BordersOuterV", s.flags1, TF.BordersOuterV)
    _, s.flags1 = ImGui.CheckboxFlags("ImGuiTableFlags_BordersInnerV", s.flags1, TF.BordersInnerV)
    _, s.show_headers = ImGui.Checkbox("show_headers", s.show_headers)
    PopStyleCompact()

    if ImGui.BeginTable("table_padding", 3, s.flags1) then
        if s.show_headers then
            ImGui.TableSetupColumn("One")
            ImGui.TableSetupColumn("Two")
            ImGui.TableSetupColumn("Three")
            ImGui.TableHeadersRow()
        end

        for row = 0, 4 do
            ImGui.TableNextRow()
            for column = 0, 2 do
                ImGui.TableSetColumnIndex(column)
                if row == 0 then
                    ImGui.Text("Avail %.2f", ImGui.GetContentRegionAvail().x)
                else
                    local buf = string.format("Hello %d,%d", column, row)
                    ImGui.Button(buf, ImVec2(-FLT_MIN, 0.0))
                end
                -- if bit32.band(ImGui.TableGetColumnFlags(), ImGuiTableColumnFlags.IsHovered) ~= 0 then
                --     ImGui.TableSetBgColor(ImGuiTableBgTarget.CellBg, IM_COL32(0, 100, 0, 255))
                -- end
            end
        end
        ImGui.EndTable()
    end

    -- Second example: set style.CellPadding to (0.0) or a custom value.
    -- FIXME-TABLE: Vertical border effectively not displayed the same way as horizontal one...
    DemoHelpMarker("Setting style.CellPadding to (0,0) or a custom value.")

    PushStyleCompact()
    _, s.flags2 = ImGui.CheckboxFlags("ImGuiTableFlags_Borders", s.flags2, TF.Borders)
    _, s.flags2 = ImGui.CheckboxFlags("ImGuiTableFlags_BordersH", s.flags2, TF.BordersH)
    _, s.flags2 = ImGui.CheckboxFlags("ImGuiTableFlags_BordersV", s.flags2, TF.BordersV)
    _, s.flags2 = ImGui.CheckboxFlags("ImGuiTableFlags_BordersInner", s.flags2, TF.BordersInner)
    _, s.flags2 = ImGui.CheckboxFlags("ImGuiTableFlags_BordersOuter", s.flags2, TF.BordersOuter)
    _, s.flags2 = ImGui.CheckboxFlags("ImGuiTableFlags_RowBg", s.flags2, TF.RowBg)
    _, s.flags2 = ImGui.CheckboxFlags("ImGuiTableFlags_Resizable", s.flags2, TF.Resizable)
    _, s.show_widget_frame_bg = ImGui.Checkbox("show_widget_frame_bg", s.show_widget_frame_bg)
    ImGui.SliderFloat2("CellPadding", s.cell_padding, 0.0, 10.0, "%.0f")
    PopStyleCompact()

    ImGui.PushStyleVar(ImGuiStyleVar.CellPadding, s.cell_padding)
    if ImGui.BeginTable("table_padding_2", 3, s.flags2) then
        if not s.show_widget_frame_bg then
            ImGui.PushStyleColor(ImGuiCol.FrameBg, 0)
        end
        for cell = 0, 3 * 5 - 1 do
            ImGui.TableNextColumn()
            if s.init then
                s.text_bufs[cell + 1] = Buf("edit me", 16)
            end
            ImGui.SetNextItemWidth(-FLT_MIN)
            ImGui.PushID(cell)
            ImGui.InputText("##cell", s.text_bufs[cell + 1], 16)
            ImGui.PopID()
        end
        if not s.show_widget_frame_bg then
            ImGui.PopStyleColor()
        end
        s.init = false
        ImGui.EndTable()
    end
    ImGui.PopStyleVar()
end

local function Tables_SizingPolicies()
    IMGUI_DEMO_MARKER("Tables/Explicit widths")
    local s = ST.sizing
    if s == nil then
        s = { flags1 = bor(TF.BordersV, TF.BordersOuterH, TF.RowBg, TF.ContextMenuInBody),
              sizing_policy_flags = { TF.SizingFixedFit, TF.SizingFixedSame, TF.SizingStretchProp, TF.SizingStretchSame },
              flags = bor(TF.ScrollY, TF.Borders, TF.RowBg, TF.Resizable), contents_type = 0, column_count = 3, text_buf = Buf("", 32) }
        ST.sizing = s
    end
    PushStyleCompact()
    _, s.flags1 = ImGui.CheckboxFlags("ImGuiTableFlags_Resizable", s.flags1, TF.Resizable)
    _, s.flags1 = ImGui.CheckboxFlags("ImGuiTableFlags_NoHostExtendX", s.flags1, TF.NoHostExtendX)
    PopStyleCompact()

    for table_n = 0, 3 do
        ImGui.PushID(table_n)
        ImGui.SetNextItemWidth(TEXT_BASE_WIDTH * 30)
        s.sizing_policy_flags[table_n + 1] = EditTableSizingFlags(s.sizing_policy_flags[table_n + 1])

        -- To make it easier to understand the different sizing policy,
        -- For each policy: we display one table where the columns have equal contents width,
        -- and one where the columns have different contents width.
        if ImGui.BeginTable("table1", 3, bor(s.sizing_policy_flags[table_n + 1], s.flags1)) then
            for row = 0, 2 do
                ImGui.TableNextRow()
                ImGui.TableNextColumn(); ImGui.Text("Oh dear")
                ImGui.TableNextColumn(); ImGui.Text("Oh dear")
                ImGui.TableNextColumn(); ImGui.Text("Oh dear")
            end
            ImGui.EndTable()
        end
        if ImGui.BeginTable("table2", 3, bor(s.sizing_policy_flags[table_n + 1], s.flags1)) then
            for row = 0, 2 do
                ImGui.TableNextRow()
                ImGui.TableNextColumn(); ImGui.Text("AAAA")
                ImGui.TableNextColumn(); ImGui.Text("BBBBBBBB")
                ImGui.TableNextColumn(); ImGui.Text("CCCCCCCCCCCC")
            end
            ImGui.EndTable()
        end
        ImGui.PopID()
    end

    ImGui.Spacing()
    ImGui.TextUnformatted("Advanced")
    ImGui.SameLine()
    DemoHelpMarker(
        "This section allows you to interact and see the effect of various sizing policies " ..
        "depending on whether Scroll is enabled and the contents of your columns.")

    local CT_ShowWidth, CT_ShortText, CT_LongText, CT_Button, CT_FillButton, CT_InputText = 0, 1, 2, 3, 4, 5

    PushStyleCompact()
    ImGui.PushID("Advanced")
    ImGui.PushItemWidth(TEXT_BASE_WIDTH * 30)
    s.flags = EditTableSizingFlags(s.flags)
    if ImGui.Combo then
        s.contents_type = ImGui.Combo("Contents", s.contents_type, { "Show width", "Short Text", "Long Text", "Button", "Fill Button", "InputText" }, 6)
    else
        NotPorted("Combo")
    end
    if s.contents_type == CT_FillButton then
        ImGui.SameLine()
        DemoHelpMarker(
            "Be mindful that using right-alignment (e.g. size.x = -FLT_MIN) creates a feedback loop " ..
            "where contents width can feed into auto-column width can feed into contents width.")
    end
    s.column_count = ImGui.DragInt("Columns", s.column_count, 0.1, 1, 64, "%d", ImGuiSliderFlags.AlwaysClamp)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Resizable", s.flags, TF.Resizable)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_PreciseWidths", s.flags, TF.PreciseWidths)
    ImGui.SameLine(); DemoHelpMarker("Disable distributing remainder width to stretched columns (width allocation on a 100-wide table with 3 columns: Without this flag: 33,33,34. With this flag: 33,33,33). With larger number of columns, resizing will appear to be less smooth.")
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_ScrollX", s.flags, TF.ScrollX)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_ScrollY", s.flags, TF.ScrollY)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoClip", s.flags, TF.NoClip)
    ImGui.PopItemWidth()
    ImGui.PopID()
    PopStyleCompact()

    if ImGui.BeginTable("table2", s.column_count, s.flags, ImVec2(0.0, TEXT_BASE_HEIGHT * 7)) then
        for cell = 0, 10 * s.column_count - 1 do
            ImGui.TableNextColumn()
            local column = ImGui.TableGetColumnIndex()
            local row = ImGui.TableGetRowIndex()

            ImGui.PushID(cell)
            local label = string.format("Hello %d,%d", column, row)
            local ct = s.contents_type
            if ct == CT_ShortText then ImGui.TextUnformatted(label)
            elseif ct == CT_LongText then ImGui.Text("Some %s text %d,%d\nOver two lines..", column == 0 and "long" or "longeeer", column, row)
            elseif ct == CT_ShowWidth then ImGui.Text("W: %.1f", ImGui.GetContentRegionAvail().x)
            elseif ct == CT_Button then ImGui.Button(label)
            elseif ct == CT_FillButton then ImGui.Button(label, ImVec2(-FLT_MIN, 0.0))
            elseif ct == CT_InputText then ImGui.SetNextItemWidth(-FLT_MIN); ImGui.InputText("##", s.text_buf, 32)
            end
            ImGui.PopID()
        end
        ImGui.EndTable()
    end
end

local function Tables_VerticalScrolling()
    IMGUI_DEMO_MARKER("Tables/Vertical scrolling, with clipping")
    DemoHelpMarker(
        "Here we activate ScrollY, which will create a child window container to allow hosting scrollable contents.\n\n" ..
        "We also demonstrate using ImGuiListClipper to virtualize the submission of many items.")
    local s = ST.vscroll
    if s == nil then s = { flags = bor(TF.ScrollY, TF.RowBg, TF.BordersOuter, TF.BordersV, TF.Resizable, TF.Reorderable, TF.Hideable) }; ST.vscroll = s end

    PushStyleCompact()
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_ScrollY", s.flags, TF.ScrollY)
    PopStyleCompact()

    -- When using ScrollX or ScrollY we need to specify a size for our table container!
    -- Otherwise by default the table will fit all available space, like a BeginChild() call.
    local outer_size = ImVec2(0.0, TEXT_BASE_HEIGHT * 8)
    if ImGui.BeginTable("table_scrolly", 3, s.flags, outer_size) then
        ImGui.TableSetupScrollFreeze(0, 1) -- Make top row always visible
        ImGui.TableSetupColumn("One", ImGuiTableColumnFlags.None)
        ImGui.TableSetupColumn("Two", ImGuiTableColumnFlags.None)
        ImGui.TableSetupColumn("Three", ImGuiTableColumnFlags.None)
        ImGui.TableHeadersRow()

        -- Demonstrate using clipper for large vertical lists
        local clipper = ImGuiListClipper()
        clipper:Begin(1000)
        while clipper:Step() do
            for row = clipper.DisplayStart, clipper.DisplayEnd - 1 do
                ImGui.TableNextRow()
                for column = 0, 2 do
                    ImGui.TableSetColumnIndex(column)
                    ImGui.Text("Hello %d,%d", column, row)
                end
            end
        end
        ImGui.EndTable()
    end
end

local function Tables_HorizontalScrolling()
    IMGUI_DEMO_MARKER("Tables/Horizontal scrolling")
    DemoHelpMarker(
        "When ScrollX is enabled, the default sizing policy becomes ImGuiTableFlags_SizingFixedFit, " ..
        "as automatically stretching columns doesn't make much sense with horizontal scrolling.\n\n" ..
        "Also note that as of the current version, you will almost always want to enable ScrollY along with ScrollX, " ..
        "because the container window won't automatically extend vertically to fix contents " ..
        "(this may be improved in future versions).")
    local s = ST.hscroll
    if s == nil then
        s = { flags = bor(TF.ScrollX, TF.ScrollY, TF.RowBg, TF.BordersOuter, TF.BordersV, TF.Resizable, TF.Reorderable, TF.Hideable),
              freeze_cols = 1, freeze_rows = 1,
              flags2 = bor(TF.SizingStretchSame, TF.ScrollX, TF.ScrollY, TF.BordersOuter, TF.RowBg, TF.ContextMenuInBody), inner_width = 1000.0 }
        ST.hscroll = s
    end

    PushStyleCompact()
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Resizable", s.flags, TF.Resizable)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_ScrollX", s.flags, TF.ScrollX)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_ScrollY", s.flags, TF.ScrollY)
    ImGui.SetNextItemWidth(ImGui.GetFrameHeight())
    s.freeze_cols = ImGui.DragInt("freeze_cols", s.freeze_cols, 0.2, 0, 9, nil, ImGuiSliderFlags.NoInput)
    ImGui.SetNextItemWidth(ImGui.GetFrameHeight())
    s.freeze_rows = ImGui.DragInt("freeze_rows", s.freeze_rows, 0.2, 0, 9, nil, ImGuiSliderFlags.NoInput)
    PopStyleCompact()

    -- When using ScrollX or ScrollY we need to specify a size for our table container!
    -- Otherwise by default the table will fit all available space, like a BeginChild() call.
    local outer_size = ImVec2(0.0, TEXT_BASE_HEIGHT * 8)
    if ImGui.BeginTable("table_scrollx", 7, s.flags, outer_size) then
        ImGui.TableSetupScrollFreeze(s.freeze_cols, s.freeze_rows)
        ImGui.TableSetupColumn("Line #", ImGuiTableColumnFlags.NoHide) -- Make the first column not hideable to match our use of TableSetupScrollFreeze()
        ImGui.TableSetupColumn("One")
        ImGui.TableSetupColumn("Two")
        ImGui.TableSetupColumn("Three")
        ImGui.TableSetupColumn("Four")
        ImGui.TableSetupColumn("Five")
        ImGui.TableSetupColumn("Six")
        ImGui.TableHeadersRow()
        for row = 0, 19 do
            ImGui.TableNextRow()
            for column = 0, 6 do repeat
                -- Both TableNextColumn() and TableSetColumnIndex() return true when a column is visible or performing width measurement.
                -- Because here we know that:
                -- - A) all our columns are contributing the same to row height
                -- - B) column 0 is always visible,
                -- We only always submit this one column and can skip others.
                -- More advanced per-column clipping behaviors may benefit from polling the status flags via TableGetColumnFlags().
                if not ImGui.TableSetColumnIndex(column) and column > 0 then
                    break -- continue
                end
                if column == 0 then
                    ImGui.Text("Line %d", row)
                else
                    ImGui.Text("Hello world %d,%d", column, row)
                end
            until true end
        end
        ImGui.EndTable()
    end

    ImGui.Spacing()
    ImGui.TextUnformatted("Stretch + ScrollX")
    ImGui.SameLine()
    DemoHelpMarker(
        "Showcase using Stretch columns + ScrollX together: " ..
        "this is rather unusual and only makes sense when specifying an 'inner_width' for the table!\n" ..
        "Without an explicit value, inner_width is == outer_size.x and therefore using Stretch columns " ..
        "along with ScrollX doesn't make sense.")
    PushStyleCompact()
    ImGui.PushID("flags3")
    ImGui.PushItemWidth(TEXT_BASE_WIDTH * 30)
    _, s.flags2 = ImGui.CheckboxFlags("ImGuiTableFlags_ScrollX", s.flags2, TF.ScrollX)
    s.inner_width = ImGui.DragFloat("inner_width", s.inner_width, 1.0, 0.0, FLT_MAX, "%.1f")
    ImGui.PopItemWidth()
    ImGui.PopID()
    PopStyleCompact()
    if ImGui.BeginTable("table2", 7, s.flags2, outer_size, s.inner_width) then
        for cell = 0, 20 * 7 - 1 do
            ImGui.TableNextColumn()
            ImGui.Text("Hello world %d,%d", ImGui.TableGetColumnIndex(), ImGui.TableGetRowIndex())
        end
        ImGui.EndTable()
    end
end

local function Tables_ColumnsFlags()
    IMGUI_DEMO_MARKER("Tables/Columns flags")
    -- Create a first table just to show all the options/flags we want to make visible in our example!
    local column_count = 3
    local column_names = { "One", "Two", "Three" }
    local s = ST.colflags
    if s == nil then
        s = { column_flags = { ImGuiTableColumnFlags.DefaultSort, ImGuiTableColumnFlags.None, ImGuiTableColumnFlags.DefaultHide }, column_flags_out = { 0, 0, 0 } } -- column_flags_out: Output from TableGetColumnFlags()
        ST.colflags = s
    end

    if ImGui.BeginTable("table_columns_flags_checkboxes", column_count, ImGuiTableFlags.None) then
        PushStyleCompact()
        for column = 1, column_count do
            ImGui.TableNextColumn()
            ImGui.PushID(column - 1)
            ImGui.AlignTextToFramePadding() -- FIXME-TABLE: Workaround for wrong text baseline propagation across columns
            ImGui.Text("'%s'", column_names[column])
            ImGui.Spacing()
            ImGui.Text("Input flags:")
            s.column_flags[column] = EditTableColumnsFlags(s.column_flags[column])
            ImGui.Spacing()
            ImGui.Text("Output flags:")
            ImGui.BeginDisabled()
            ShowTableColumnsStatusFlags(s.column_flags_out[column])
            ImGui.EndDisabled()
            ImGui.PopID()
        end
        PopStyleCompact()
        ImGui.EndTable()
    end

    -- Create the real table we care about for the example!
    -- We use a scrolling table to be able to showcase the difference between the _IsEnabled and _IsVisible flags above,
    -- otherwise in a non-scrolling table columns are always visible (unless using ImGuiTableFlags_NoKeepColumnsVisible
    -- + resizing the parent window down).
    local flags = bor(TF.SizingFixedFit, TF.ScrollX, TF.ScrollY, TF.RowBg, TF.BordersOuter, TF.BordersV, TF.Resizable, TF.Reorderable, TF.Hideable, TF.Sortable)
    local outer_size = ImVec2(0.0, TEXT_BASE_HEIGHT * 9)
    if ImGui.BeginTable("table_columns_flags", column_count, flags, outer_size) then
        local has_angled_header = false
        for column = 1, column_count do
            has_angled_header = has_angled_header or Has(s.column_flags[column], ImGuiTableColumnFlags.AngledHeader)
            ImGui.TableSetupColumn(column_names[column], s.column_flags[column])
        end
        if has_angled_header then
            ImGui.TableAngledHeadersRow()
        end
        ImGui.TableHeadersRow()
        for column = 1, column_count do
            s.column_flags_out[column] = ImGui.TableGetColumnFlags(column - 1)
        end
        local indent_step = math.floor(math.floor(TEXT_BASE_WIDTH) / 2)
        for row = 0, 7 do
            -- Add some indentation to demonstrate usage of per-column IndentEnable/IndentDisable flags.
            ImGui.Indent(indent_step)
            ImGui.TableNextRow()
            for column = 0, column_count - 1 do
                ImGui.TableSetColumnIndex(column)
                ImGui.Text("%s %s", (column == 0) and "Indented" or "Hello", ImGui.TableGetColumnName(column))
            end
        end
        ImGui.Unindent(indent_step * 8.0)

        ImGui.EndTable()
    end
end

local function Tables_ColumnsWidths()
    IMGUI_DEMO_MARKER("Tables/Columns widths")
    DemoHelpMarker("Using TableSetupColumn() to setup default width.")
    local s = ST.colwidths
    if s == nil then s = { flags1 = bor(TF.Borders, TF.NoBordersInBodyUntilResize), flags2 = TF.None }; ST.colwidths = s end
    local CF = ImGuiTableColumnFlags

    PushStyleCompact()
    _, s.flags1 = ImGui.CheckboxFlags("ImGuiTableFlags_Resizable", s.flags1, TF.Resizable)
    _, s.flags1 = ImGui.CheckboxFlags("ImGuiTableFlags_NoBordersInBodyUntilResize", s.flags1, TF.NoBordersInBodyUntilResize)
    PopStyleCompact()
    if ImGui.BeginTable("table1", 3, s.flags1) then
        -- We could also set ImGuiTableFlags_SizingFixedFit on the table and all columns will default to ImGuiTableColumnFlags_WidthFixed.
        ImGui.TableSetupColumn("one", CF.WidthFixed, 100.0) -- Default to 100.0f
        ImGui.TableSetupColumn("two", CF.WidthFixed, 200.0) -- Default to 200.0f
        ImGui.TableSetupColumn("three", CF.WidthFixed)      -- Default to auto
        ImGui.TableHeadersRow()
        for row = 0, 3 do
            ImGui.TableNextRow()
            for column = 0, 2 do
                ImGui.TableSetColumnIndex(column)
                if row == 0 then
                    ImGui.Text("(w: %5.1f)", ImGui.GetContentRegionAvail().x)
                else
                    ImGui.Text("Hello %d,%d", column, row)
                end
            end
        end
        ImGui.EndTable()
    end

    DemoHelpMarker(
        "Using TableSetupColumn() to setup explicit width.\n\nUnless _NoKeepColumnsVisible is set, " ..
        "fixed columns with set width may still be shrunk down if there's not enough space in the host.")

    PushStyleCompact()
    _, s.flags2 = ImGui.CheckboxFlags("ImGuiTableFlags_NoKeepColumnsVisible", s.flags2, TF.NoKeepColumnsVisible)
    _, s.flags2 = ImGui.CheckboxFlags("ImGuiTableFlags_BordersInnerV", s.flags2, TF.BordersInnerV)
    _, s.flags2 = ImGui.CheckboxFlags("ImGuiTableFlags_BordersOuterV", s.flags2, TF.BordersOuterV)
    PopStyleCompact()
    if ImGui.BeginTable("table2", 4, s.flags2) then
        -- We could also set ImGuiTableFlags_SizingFixedFit on the table and then all columns
        -- will default to ImGuiTableColumnFlags_WidthFixed.
        ImGui.TableSetupColumn("", CF.WidthFixed, 100.0)
        ImGui.TableSetupColumn("", CF.WidthFixed, TEXT_BASE_WIDTH * 15.0)
        ImGui.TableSetupColumn("", CF.WidthFixed, TEXT_BASE_WIDTH * 30.0)
        ImGui.TableSetupColumn("", CF.WidthFixed, TEXT_BASE_WIDTH * 15.0)
        for row = 0, 4 do
            ImGui.TableNextRow()
            for column = 0, 3 do
                ImGui.TableSetColumnIndex(column)
                if row == 0 then
                    ImGui.Text("(w: %5.1f)", ImGui.GetContentRegionAvail().x)
                else
                    ImGui.Text("Hello %d,%d", column, row)
                end
            end
        end
        ImGui.EndTable()
    end
end

local function Tables_Nested()
    IMGUI_DEMO_MARKER("Tables/Nested tables")
    DemoHelpMarker("This demonstrates embedding a table into another table cell.")

    if ImGui.BeginTable("table_nested1", 2, bor(TF.Borders, TF.Resizable, TF.Reorderable, TF.Hideable)) then
        ImGui.TableSetupColumn("A0")
        ImGui.TableSetupColumn("A1")
        ImGui.TableHeadersRow()

        ImGui.TableNextColumn()
        ImGui.Text("A0 Row 0")
        do
            local rows_height = (TEXT_BASE_HEIGHT * 2.0) + (ImGui.GetStyle().CellPadding.y * 2.0)
            if ImGui.BeginTable("table_nested2", 2, bor(TF.Borders, TF.Resizable, TF.Reorderable, TF.Hideable)) then
                ImGui.TableSetupColumn("B0")
                ImGui.TableSetupColumn("B1")
                ImGui.TableHeadersRow()

                ImGui.TableNextRow(ImGuiTableRowFlags.None, rows_height)
                ImGui.TableNextColumn()
                ImGui.Text("B0 Row 0")
                ImGui.TableNextColumn()
                ImGui.Text("B1 Row 0")
                ImGui.TableNextRow(ImGuiTableRowFlags.None, rows_height)
                ImGui.TableNextColumn()
                ImGui.Text("B0 Row 1")
                ImGui.TableNextColumn()
                ImGui.Text("B1 Row 1")

                ImGui.EndTable()
            end
        end
        ImGui.TableNextColumn(); ImGui.Text("A1 Row 0")
        ImGui.TableNextColumn(); ImGui.Text("A0 Row 1")
        ImGui.TableNextColumn(); ImGui.Text("A1 Row 1")
        ImGui.EndTable()
    end
end

local function Tables_RowHeight()
    IMGUI_DEMO_MARKER("Tables/Row height")
    DemoHelpMarker(
        "You can pass a 'min_row_height' to TableNextRow().\n\nRows are padded with 'style.CellPadding.y' on top and bottom, " ..
        "so effectively the minimum row height will always be >= 'style.CellPadding.y * 2.0f'.\n\n" ..
        "We cannot honor a _maximum_ row height as that would require a unique clipping rectangle per row.")
    if ImGui.BeginTable("table_row_height", 1, TF.Borders) then
        for row = 0, 7 do
            local min_row_height = math.floor(TEXT_BASE_HEIGHT * 0.30 * row + ImGui.GetStyle().CellPadding.y * 2.0)
            ImGui.TableNextRow(ImGuiTableRowFlags.None, min_row_height)
            ImGui.TableNextColumn()
            ImGui.Text("min_row_height = %.2f", min_row_height)
        end
        ImGui.EndTable()
    end

    DemoHelpMarker(
        "Showcase using SameLine(0,0) to share Current Line Height between cells.\n\n" ..
        "Please note that Tables Row Height is not the same thing as Current Line Height, " ..
        "as a table cell may contains multiple lines.")
    if ImGui.BeginTable("table_share_lineheight", 2, TF.Borders) then
        ImGui.TableNextRow()
        ImGui.TableNextColumn()
        ImGui.ColorButton("##1", ImVec4(0.13, 0.26, 0.40, 1.0), ImGuiColorEditFlags.None, ImVec2(40, 40))
        ImGui.TableNextColumn()
        ImGui.Text("Line 1")
        ImGui.Text("Line 2")

        ImGui.TableNextRow()
        ImGui.TableNextColumn()
        ImGui.ColorButton("##2", ImVec4(0.13, 0.26, 0.40, 1.0), ImGuiColorEditFlags.None, ImVec2(40, 40))
        ImGui.TableNextColumn()
        ImGui.SameLine(0.0, 0.0) -- Reuse line height from previous column
        ImGui.Text("Line 1, with SameLine(0,0)")
        ImGui.Text("Line 2")

        ImGui.EndTable()
    end

    DemoHelpMarker("Showcase altering CellPadding.y between rows. Note that CellPadding.x is locked for the entire table.")
    if ImGui.BeginTable("table_changing_cellpadding_y", 1, TF.Borders) then
        local style = ImGui.GetStyle()
        for row = 0, 7 do
            if (row % 3) == 2 then
                ImGui.PushStyleVarY(ImGuiStyleVar.CellPadding, 20.0)
            end
            ImGui.TableNextRow(ImGuiTableRowFlags.None)
            ImGui.TableNextColumn()
            ImGui.Text("CellPadding.y = %.2f", style.CellPadding.y)
            if (row % 3) == 2 then
                ImGui.PopStyleVar()
            end
        end
        ImGui.EndTable()
    end
end

local function Tables_OuterSize()
    IMGUI_DEMO_MARKER("Tables/Outer size")
    -- Showcasing use of ImGuiTableFlags_NoHostExtendX and ImGuiTableFlags_NoHostExtendY
    -- Important to that note how the two flags have slightly different behaviors!
    ImGui.Text("Using NoHostExtendX and NoHostExtendY:")
    PushStyleCompact()
    local s = ST.outer
    if s == nil then s = { flags = bor(TF.Borders, TF.Resizable, TF.ContextMenuInBody, TF.RowBg, TF.SizingFixedFit, TF.NoHostExtendX) }; ST.outer = s end
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoHostExtendX", s.flags, TF.NoHostExtendX)
    ImGui.SameLine(); DemoHelpMarker("Make outer width auto-fit to columns, overriding outer_size.x value.\n\nOnly available when ScrollX/ScrollY are disabled and Stretch columns are not used.")
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoHostExtendY", s.flags, TF.NoHostExtendY)
    ImGui.SameLine(); DemoHelpMarker("Make outer height stop exactly at outer_size.y (prevent auto-extending table past the limit).\n\nOnly available when ScrollX/ScrollY are disabled. Data below the limit will be clipped and not visible.")
    PopStyleCompact()

    local outer_size = ImVec2(0.0, TEXT_BASE_HEIGHT * 5.5)
    if ImGui.BeginTable("table1", 3, s.flags, outer_size) then
        for row = 0, 9 do
            ImGui.TableNextRow()
            for column = 0, 2 do
                ImGui.TableNextColumn()
                ImGui.Text("Cell %d,%d", column, row)
            end
        end
        ImGui.EndTable()
    end
    ImGui.SameLine()
    ImGui.Text("Hello!")

    ImGui.Spacing()

    ImGui.Text("Using explicit size:")
    if ImGui.BeginTable("table2", 3, bor(TF.Borders, TF.RowBg), ImVec2(TEXT_BASE_WIDTH * 30, 0.0)) then
        for row = 0, 4 do
            ImGui.TableNextRow()
            for column = 0, 2 do
                ImGui.TableNextColumn()
                ImGui.Text("Cell %d,%d", column, row)
            end
        end
        ImGui.EndTable()
    end
    ImGui.SameLine()
    if ImGui.BeginTable("table3", 3, bor(TF.Borders, TF.RowBg), ImVec2(TEXT_BASE_WIDTH * 30, 0.0)) then
        local rows_height = TEXT_BASE_HEIGHT * 1.5 + ImGui.GetStyle().CellPadding.y * 2.0
        for row = 0, 2 do
            ImGui.TableNextRow(0, rows_height)
            for column = 0, 2 do
                ImGui.TableNextColumn()
                ImGui.Text("Cell %d,%d", column, row)
            end
        end
        ImGui.EndTable()
    end
end

local function Tables_BackgroundColor()
    IMGUI_DEMO_MARKER("Tables/Background color")
    local s = ST.bgcolor
    if s == nil then s = { flags = TF.RowBg, row_bg_type = 1, row_bg_target = 1, cell_bg_type = 1 }; ST.bgcolor = s end

    PushStyleCompact()
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Borders", s.flags, TF.Borders)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_RowBg", s.flags, TF.RowBg)
    ImGui.SameLine(); DemoHelpMarker("ImGuiTableFlags_RowBg automatically sets RowBg0 to alternative colors pulled from the Style.")
    if ImGui.Combo then
        s.row_bg_type = ImGui.Combo("row bg type", s.row_bg_type, { "None", "Red", "Gradient" }, 3)
        s.row_bg_target = ImGui.Combo("row bg target", s.row_bg_target, { "RowBg0", "RowBg1" }, 2); ImGui.SameLine(); DemoHelpMarker("Target RowBg0 to override the alternating odd/even colors,\nTarget RowBg1 to blend with them.")
        s.cell_bg_type = ImGui.Combo("cell bg type", s.cell_bg_type, { "None", "Blue" }, 2); ImGui.SameLine(); DemoHelpMarker("We are colorizing cells to B1->C2 here.")
    else
        NotPorted("Combo")
    end
    IM_ASSERT(s.row_bg_type >= 0 and s.row_bg_type <= 2)
    IM_ASSERT(s.row_bg_target >= 0 and s.row_bg_target <= 1)
    IM_ASSERT(s.cell_bg_type >= 0 and s.cell_bg_type <= 1)
    PopStyleCompact()

    if ImGui.BeginTable("table1", 5, s.flags) then
        for row = 0, 5 do
            ImGui.TableNextRow()

            -- Demonstrate setting a row background color with 'ImGui.TableSetBgColor(ImGuiTableBgTarget.RowBgX, ...)'
            -- We use a transparent color so we can see the one behind in case our target is RowBg1 and RowBg0 was already targeted by the ImGuiTableFlags_RowBg flag.
            if s.row_bg_type ~= 0 then
                local row_bg_color = ImGui.GetColorU32(s.row_bg_type == 1 and ImVec4(0.7, 0.3, 0.3, 0.65) or ImVec4(0.2 + row * 0.1, 0.2, 0.2, 0.65)) -- Flat or Gradient?
                ImGui.TableSetBgColor(ImGuiTableBgTarget.RowBg0 + s.row_bg_target, row_bg_color)
            end

            -- Fill cells
            for column = 0, 4 do
                ImGui.TableSetColumnIndex(column)
                ImGui.Text("%s%s", string.char(65 + row), string.char(48 + column))

                -- Change background of Cells B1->C2
                -- Demonstrate setting a cell background color with 'ImGui.TableSetBgColor(ImGuiTableBgTarget.CellBg, ...)'
                -- (the CellBg color will be blended over the RowBg and ColumnBg colors)
                -- We can also pass a column number as a third parameter to TableSetBgColor() and do this outside the column loop.
                if row >= 1 and row <= 2 and column >= 1 and column <= 2 and s.cell_bg_type == 1 then
                    local cell_bg_color = ImGui.GetColorU32(ImVec4(0.3, 0.3, 0.7, 0.65))
                    ImGui.TableSetBgColor(ImGuiTableBgTarget.CellBg, cell_bg_color)
                end
            end
        end
        ImGui.EndTable()
    end
end

-- Simple storage to output a dummy file-system.
local tree_view_nodes = {
    { Name = "Root with Long Name",           Type = "Folder",      Size = -1,     ChildIdx = 1,  ChildCount = 3  }, -- 0
    { Name = "Music",                         Type = "Folder",      Size = -1,     ChildIdx = 4,  ChildCount = 2  }, -- 1
    { Name = "Textures",                      Type = "Folder",      Size = -1,     ChildIdx = 6,  ChildCount = 3  }, -- 2
    { Name = "desktop.ini",                   Type = "System file", Size = 1024,   ChildIdx = -1, ChildCount = -1 }, -- 3
    { Name = "File1_a.wav",                   Type = "Audio file",  Size = 123000, ChildIdx = -1, ChildCount = -1 }, -- 4
    { Name = "File1_b.wav",                   Type = "Audio file",  Size = 456000, ChildIdx = -1, ChildCount = -1 }, -- 5
    { Name = "Image001.png",                  Type = "Image file",  Size = 203128, ChildIdx = -1, ChildCount = -1 }, -- 6
    { Name = "Copy of Image001.png",          Type = "Image file",  Size = 203256, ChildIdx = -1, ChildCount = -1 }, -- 7
    { Name = "Copy of Image001 (Final2).png", Type = "Image file",  Size = 203512, ChildIdx = -1, ChildCount = -1 }, -- 8
}

local function MyTreeNode_DisplayNode(node, all_nodes, tree_node_flags_base)
    ImGui.TableNextRow()
    ImGui.TableNextColumn()
    local is_folder = (node.ChildCount > 0)

    local node_flags = tree_node_flags_base
    if node ~= all_nodes[1] then
        node_flags = bit32.band(node_flags, bit32.bnot(ImGuiTreeNodeFlags.LabelSpanAllColumns)) -- Only demonstrate this on the root node.
    end

    if is_folder then
        local open = ImGui.TreeNodeEx(node.Name, node_flags)
        if bit32.band(node_flags, ImGuiTreeNodeFlags.LabelSpanAllColumns) == 0 then
            ImGui.TableNextColumn()
            ImGui.TextDisabled("--")
            ImGui.TableNextColumn()
            ImGui.TextUnformatted(node.Type)
        end
        if open then
            for child_n = 0, node.ChildCount - 1 do
                MyTreeNode_DisplayNode(all_nodes[node.ChildIdx + child_n + 1], all_nodes, tree_node_flags_base)
            end
            ImGui.TreePop()
        end
    else
        ImGui.TreeNodeEx(node.Name, bor(node_flags, ImGuiTreeNodeFlags.Leaf, ImGuiTreeNodeFlags.Bullet, ImGuiTreeNodeFlags.NoTreePushOnOpen))
        ImGui.TableNextColumn()
        ImGui.Text("%d", node.Size)
        ImGui.TableNextColumn()
        ImGui.TextUnformatted(node.Type)
    end
end

local function Tables_TreeView()
    IMGUI_DEMO_MARKER("Tables/Tree view")
    local s = ST.treeview
    if s == nil then
        s = { table_flags = bor(TF.BordersV, TF.BordersOuterH, TF.Resizable, TF.RowBg, TF.NoBordersInBody),
              tree_node_flags_base = bor(ImGuiTreeNodeFlags.SpanAllColumns, ImGuiTreeNodeFlags.DefaultOpen, ImGuiTreeNodeFlags.DrawLinesFull) }
        ST.treeview = s
    end
    _, s.tree_node_flags_base = ImGui.CheckboxFlags("ImGuiTreeNodeFlags_SpanFullWidth", s.tree_node_flags_base, ImGuiTreeNodeFlags.SpanFullWidth)
    _, s.tree_node_flags_base = ImGui.CheckboxFlags("ImGuiTreeNodeFlags_SpanLabelWidth", s.tree_node_flags_base, ImGuiTreeNodeFlags.SpanLabelWidth)
    _, s.tree_node_flags_base = ImGui.CheckboxFlags("ImGuiTreeNodeFlags_SpanAllColumns", s.tree_node_flags_base, ImGuiTreeNodeFlags.SpanAllColumns)
    _, s.tree_node_flags_base = ImGui.CheckboxFlags("ImGuiTreeNodeFlags_LabelSpanAllColumns", s.tree_node_flags_base, ImGuiTreeNodeFlags.LabelSpanAllColumns)
    ImGui.SameLine(); DemoHelpMarker("Useful if you know that you aren't displaying contents in other columns")

    DemoHelpMarker("See \"Columns flags\" section to configure how indentation is applied to individual columns.")
    if ImGui.BeginTable("3ways", 3, s.table_flags) then
        -- The first column will use the default _WidthStretch when ScrollX is Off and _WidthFixed when ScrollX is On
        ImGui.TableSetupColumn("Name", ImGuiTableColumnFlags.NoHide)
        ImGui.TableSetupColumn("Size", ImGuiTableColumnFlags.WidthFixed, TEXT_BASE_WIDTH * 12.0)
        ImGui.TableSetupColumn("Type", ImGuiTableColumnFlags.WidthFixed, TEXT_BASE_WIDTH * 18.0)
        ImGui.TableHeadersRow()

        MyTreeNode_DisplayNode(tree_view_nodes[1], tree_view_nodes, s.tree_node_flags_base)

        ImGui.EndTable()
    end
end

local function Tables_ItemWidth()
    IMGUI_DEMO_MARKER("Tables/Item width")
    DemoHelpMarker(
        "Showcase using PushItemWidth() and how it is preserved on a per-column basis.\n\n" ..
        "Note that on auto-resizing non-resizable fixed columns, querying the content width for " ..
        "e.g. right-alignment doesn't make sense.")
    if ImGui.BeginTable("table_item_width", 3, TF.Borders) then
        ImGui.TableSetupColumn("small")
        ImGui.TableSetupColumn("half")
        ImGui.TableSetupColumn("right-align")
        ImGui.TableHeadersRow()

        for row = 0, 2 do
            ImGui.TableNextRow()
            if row == 0 then
                -- Setup ItemWidth once (instead of setting up every time, which is also possible but less efficient)
                ImGui.TableSetColumnIndex(0)
                ImGui.PushItemWidth(TEXT_BASE_WIDTH * 3.0) -- Small
                ImGui.TableSetColumnIndex(1)
                ImGui.PushItemWidth(-ImGui.GetContentRegionAvail().x * 0.5)
                ImGui.TableSetColumnIndex(2)
                ImGui.PushItemWidth(-FLT_MIN) -- Right-aligned
            end

            -- Draw our contents
            ImGui.PushID(row)
            ImGui.TableSetColumnIndex(0)
            ST.dummy_f = ImGui.SliderFloat("float0", ST.dummy_f or 0.0, 0.0, 1.0)
            ImGui.TableSetColumnIndex(1)
            ST.dummy_f = ImGui.SliderFloat("float1", ST.dummy_f, 0.0, 1.0)
            ImGui.TableSetColumnIndex(2)
            ST.dummy_f = ImGui.SliderFloat("##float2", ST.dummy_f, 0.0, 1.0) -- No visible label since right-aligned
            ImGui.PopID()
        end
        ImGui.EndTable()
    end
end

-- Demonstrate using TableHeader() calls instead of TableHeadersRow()
local function Tables_CustomHeaders()
    IMGUI_DEMO_MARKER("Tables/Custom headers")
    local COLUMNS_COUNT = 3
    if ImGui.BeginTable("table_custom_headers", COLUMNS_COUNT, bor(TF.Borders, TF.Reorderable, TF.Hideable)) then
        ImGui.TableSetupColumn("Apricot")
        ImGui.TableSetupColumn("Banana")
        ImGui.TableSetupColumn("Cherry")

        -- Dummy entire-column selection storage
        -- FIXME: It would be nice to actually demonstrate full-featured selection using those checkbox.
        if ST.column_selected == nil then ST.column_selected = { false, false, false } end
        local column_selected = ST.column_selected

        -- Instead of calling TableHeadersRow() we'll submit custom headers ourselves.
        -- (A different approach is also possible:
        --    - Specify ImGuiTableColumnFlags_NoHeaderLabel in some TableSetupColumn() call.
        --    - Call TableHeadersRow() normally. This will submit TableHeader() with no name.
        --    - Then call TableSetColumnIndex() to position yourself in the column and submit your stuff e.g. Checkbox().)
        ImGui.TableNextRow(ImGuiTableRowFlags.Headers)
        for column = 0, COLUMNS_COUNT - 1 do
            ImGui.TableSetColumnIndex(column)
            local column_name = ImGui.TableGetColumnName(column) -- Retrieve name passed to TableSetupColumn()
            ImGui.PushID(column)
            ImGui.PushStyleVar(ImGuiStyleVar.FramePadding, ImVec2(0, 0))
            _, column_selected[column + 1] = ImGui.Checkbox("##checkall", column_selected[column + 1])
            ImGui.PopStyleVar()
            ImGui.SameLine(0.0, ImGui.GetStyle().ItemInnerSpacing.x)
            ImGui.TableHeader(column_name)
            ImGui.PopID()
        end

        -- Submit table contents
        for row = 0, 4 do
            ImGui.TableNextRow()
            for column = 0, 2 do
                local buf = string.format("Cell %d,%d", column, row)
                ImGui.TableSetColumnIndex(column)
                ImGui.Selectable(buf, column_selected[column + 1])
            end
        end
        ImGui.EndTable()
    end
end

-- Demonstrate using ImGuiTableColumnFlags_AngledHeader flag to create angled headers
local function Tables_AngledHeaders()
    IMGUI_DEMO_MARKER("Tables/Angled headers")
    local column_names = { "Track", "cabasa", "ride", "smash", "tom-hi", "tom-mid", "tom-low", "hihat-o", "hihat-c", "snare-s", "snare-c", "clap", "rim", "kick" }
    local columns_count = #column_names
    local rows_count = 12

    local s = ST.angled
    if s == nil then
        s = { table_flags = bor(TF.SizingFixedFit, TF.ScrollX, TF.ScrollY, TF.BordersOuter, TF.BordersInnerH, TF.Hideable, TF.Resizable, TF.Reorderable, TF.HighlightHoveredColumn),
              column_flags = bor(ImGuiTableColumnFlags.AngledHeader, ImGuiTableColumnFlags.WidthFixed),
              bools = {}, frozen_cols = 1, frozen_rows = 2 } -- bools: Dummy storage selection storage
        for i = 1, columns_count * rows_count do s.bools[i] = false end
        ST.angled = s
    end
    _, s.table_flags = ImGui.CheckboxFlags("_ScrollX", s.table_flags, TF.ScrollX)
    _, s.table_flags = ImGui.CheckboxFlags("_ScrollY", s.table_flags, TF.ScrollY)
    _, s.table_flags = ImGui.CheckboxFlags("_Resizable", s.table_flags, TF.Resizable)
    _, s.table_flags = ImGui.CheckboxFlags("_Sortable", s.table_flags, TF.Sortable)
    _, s.table_flags = ImGui.CheckboxFlags("_NoBordersInBody", s.table_flags, TF.NoBordersInBody)
    _, s.table_flags = ImGui.CheckboxFlags("_HighlightHoveredColumn", s.table_flags, TF.HighlightHoveredColumn)
    ImGui.SetNextItemWidth(ImGui.GetFontSize() * 8)
    s.frozen_cols = ImGui.SliderInt("Frozen columns", s.frozen_cols, 0, 2)
    ImGui.SetNextItemWidth(ImGui.GetFontSize() * 8)
    s.frozen_rows = ImGui.SliderInt("Frozen rows", s.frozen_rows, 0, 2)
    _, s.column_flags = ImGui.CheckboxFlags("Disable header contributing to column width", s.column_flags, ImGuiTableColumnFlags.NoHeaderWidth)

    if ImGui.TreeNode("Style settings") then
        ImGui.SameLine()
        DemoHelpMarker("Giving access to some ImGuiStyle value in this demo for convenience.")
        ImGui.SetNextItemWidth(ImGui.GetFontSize() * 8)
        local style = ImGui.GetStyle()
        style.TableAngledHeadersAngle = ImGui.SliderAngle("style.TableAngledHeadersAngle", style.TableAngledHeadersAngle, -50.0, 50.0)
        ImGui.SetNextItemWidth(ImGui.GetFontSize() * 8)
        ImGui.SliderFloat2("style.TableAngledHeadersTextAlign", style.TableAngledHeadersTextAlign, 0.0, 1.0, "%.2f")
        ImGui.TreePop()
    end

    if ImGui.BeginTable("table_angled_headers", columns_count, s.table_flags, ImVec2(0.0, TEXT_BASE_HEIGHT * 12)) then
        ImGui.TableSetupColumn(column_names[1], bor(ImGuiTableColumnFlags.NoHide, ImGuiTableColumnFlags.NoReorder))
        for n = 2, columns_count do
            ImGui.TableSetupColumn(column_names[n], s.column_flags)
        end
        ImGui.TableSetupScrollFreeze(s.frozen_cols, s.frozen_rows)

        ImGui.TableAngledHeadersRow() -- Draw angled headers for all columns with the ImGuiTableColumnFlags_AngledHeader flag.
        ImGui.TableHeadersRow()       -- Draw remaining headers and allow access to context-menu and other functions.
        for row = 0, rows_count - 1 do
            ImGui.PushID(row)
            ImGui.TableNextRow()
            ImGui.TableSetColumnIndex(0)
            ImGui.AlignTextToFramePadding()
            ImGui.Text("Track %d", row)
            for column = 1, columns_count - 1 do
                if ImGui.TableSetColumnIndex(column) then
                    ImGui.PushID(column)
                    local idx = row * columns_count + column + 1
                    _, s.bools[idx] = ImGui.Checkbox("", s.bools[idx])
                    ImGui.PopID()
                end
            end
            ImGui.PopID()
        end
        ImGui.EndTable()
    end
end

-- Demonstrate creating custom context menus inside columns,
-- while playing it nice with context menus provided by TableHeadersRow()/TableHeader()
local function Tables_ContextMenus()
    IMGUI_DEMO_MARKER("Tables/Context menus")
    DemoHelpMarker(
        "By default, right-clicking over a TableHeadersRow()/TableHeader() line will open the default context-menu.\n" ..
        "Using ImGuiTableFlags_ContextMenuInBody we also allow right-clicking over columns body.")
    local s = ST.ctxmenu
    if s == nil then s = { flags1 = bor(TF.Resizable, TF.Reorderable, TF.Hideable, TF.Borders, TF.ContextMenuInBody) }; ST.ctxmenu = s end

    PushStyleCompact()
    _, s.flags1 = ImGui.CheckboxFlags("ImGuiTableFlags_ContextMenuInBody", s.flags1, TF.ContextMenuInBody)
    PopStyleCompact()

    -- Context Menus: first example
    -- [1.1] Right-click on the TableHeadersRow() line to open the default table context menu.
    -- [1.2] Right-click in columns also open the default table context menu (if ImGuiTableFlags_ContextMenuInBody is set)
    local COLUMNS_COUNT = 3
    if ImGui.BeginTable("table_context_menu", COLUMNS_COUNT, s.flags1) then
        ImGui.TableSetupColumn("One")
        ImGui.TableSetupColumn("Two")
        ImGui.TableSetupColumn("Three")

        -- [1.1]] Right-click on the TableHeadersRow() line to open the default table context menu.
        ImGui.TableHeadersRow()

        -- Submit dummy contents
        for row = 0, 3 do
            ImGui.TableNextRow()
            for column = 0, COLUMNS_COUNT - 1 do
                ImGui.TableSetColumnIndex(column)
                ImGui.Text("Cell %d,%d", column, row)
            end
        end
        ImGui.EndTable()
    end

    -- Context Menus: second example
    -- [2.1] Right-click on the TableHeadersRow() line to open the default table context menu.
    -- [2.2] Right-click on the ".." to open a custom popup
    -- [2.3] Right-click in columns to open another custom popup
    DemoHelpMarker(
        "Demonstrate mixing table context menu (over header), item context button (over button) " ..
        "and custom per-column context menu (over column body).")
    local flags2 = bor(TF.Resizable, TF.SizingFixedFit, TF.Reorderable, TF.Hideable, TF.Borders)
    if ImGui.BeginTable("table_context_menu_2", COLUMNS_COUNT, flags2) then
        ImGui.TableSetupColumn("One")
        ImGui.TableSetupColumn("Two")
        ImGui.TableSetupColumn("Three")

        -- [2.1] Right-click on the TableHeadersRow() line to open the default table context menu.
        ImGui.TableHeadersRow()
        for row = 0, 3 do
            ImGui.TableNextRow()
            for column = 0, COLUMNS_COUNT - 1 do
                -- Submit dummy contents
                ImGui.TableSetColumnIndex(column)
                ImGui.Text("Cell %d,%d", column, row)
                ImGui.SameLine()

                -- [2.2] Right-click on the ".." to open a custom popup
                ImGui.PushID(row * COLUMNS_COUNT + column)
                ImGui.SmallButton("..")
                if ImGui.BeginPopupContextItem() then
                    ImGui.Text("This is the popup for Button(\"..\") in Cell %d,%d", column, row)
                    if ImGui.Button("Close") then
                        ImGui.CloseCurrentPopup()
                    end
                    ImGui.EndPopup()
                end
                ImGui.PopID()
            end
        end

        -- [2.3] Right-click anywhere in columns to open another custom popup
        -- (instead of testing for not IsAnyItemHovered() we could also call OpenPopup() with ImGuiPopupFlags_NoOpenOverExistingPopup
        -- to manage popup priority as the popups triggers, here "are we hovering a column" are overlapping)
        local hovered_column = -1
        for column = 0, COLUMNS_COUNT do
            ImGui.PushID(column)
            if Has(ImGui.TableGetColumnFlags(column), ImGuiTableColumnFlags.IsHovered) then
                hovered_column = column
            end
            if hovered_column == column and not ImGui.IsAnyItemHovered() and ImGui.IsMouseReleased(1) then
                ImGui.OpenPopup("MyPopup")
            end
            if ImGui.BeginPopup("MyPopup") then
                if column == COLUMNS_COUNT then
                    ImGui.Text("This is a custom popup for unused space after the last column.")
                else
                    ImGui.Text("This is a custom popup for Column %d", column)
                end
                if ImGui.Button("Close") then
                    ImGui.CloseCurrentPopup()
                end
                ImGui.EndPopup()
            end
            ImGui.PopID()
        end

        ImGui.EndTable()
        ImGui.Text("Hovered column: %d", hovered_column)
    end
end

-- Demonstrate creating multiple tables with the same ID
local function Tables_SyncedInstances()
    IMGUI_DEMO_MARKER("Tables/Synced instances")
    DemoHelpMarker("Multiple tables with the same identifier will share their settings, width, visibility, order etc.")

    local s = ST.synced
    if s == nil then s = { flags = bor(TF.Resizable, TF.Reorderable, TF.Hideable, TF.Borders, TF.SizingFixedFit, TF.NoSavedSettings) }; ST.synced = s end
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Resizable", s.flags, TF.Resizable)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_ScrollY", s.flags, TF.ScrollY)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_SizingFixedFit", s.flags, TF.SizingFixedFit)
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_HighlightHoveredColumn", s.flags, TF.HighlightHoveredColumn)
    for n = 0, 2 do
        local buf = string.format("Synced Table %d", n)
        local open = ImGui.CollapsingHeader(buf, ImGuiTreeNodeFlags.DefaultOpen)
        if open and ImGui.BeginTable("Table", 3, s.flags, ImVec2(0.0, ImGui.GetTextLineHeightWithSpacing() * 5)) then
            ImGui.TableSetupColumn("One")
            ImGui.TableSetupColumn("Two")
            ImGui.TableSetupColumn("Three")
            ImGui.TableHeadersRow()
            local cell_count = (n == 1) and 27 or 9 -- Make second table have a scrollbar to verify that additional decoration is not affecting column positions.
            for cell = 0, cell_count - 1 do
                ImGui.TableNextColumn()
                ImGui.Text("this cell %d", cell)
            end
            ImGui.EndTable()
        end
    end
end

-- Demonstrate using Sorting facilities
-- This is a simplified version of the "Advanced" example, where we mostly focus on the code necessary to handle sorting.
-- Note that the "Advanced" example also showcase manually triggering a sort (e.g. if item quantities have been modified)
local template_items_names = {
    "Banana", "Apple", "Cherry", "Watermelon", "Grapefruit", "Strawberry", "Mango",
    "Kiwi", "Orange", "Pineapple", "Blueberry", "Plum", "Coconut", "Pear", "Apricot"
}

local function Tables_Sorting()
    IMGUI_DEMO_MARKER("Tables/Sorting")
    -- Create item list
    local s = ST.sorting
    if s == nil then
        s = { items = {},
              flags = bor(TF.Resizable, TF.Reorderable, TF.Hideable, TF.Sortable, TF.SortMulti, TF.RowBg, TF.BordersOuter, TF.BordersV, TF.NoBordersInBody, TF.ScrollY) }
        for n = 0, 49 do
            local template_n = n % #template_items_names
            s.items[n + 1] = MyItem(n, template_items_names[template_n + 1], (n * n - n) % 20) -- Assign default quantities
        end
        ST.sorting = s
    end
    local items = s.items

    -- Options
    PushStyleCompact()
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_SortMulti", s.flags, TF.SortMulti)
    ImGui.SameLine(); DemoHelpMarker("When sorting is enabled: hold shift when clicking headers to sort on multiple column. TableGetSortSpecs() may return specs where (SpecsCount > 1).")
    _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_SortTristate", s.flags, TF.SortTristate)
    ImGui.SameLine(); DemoHelpMarker("When sorting is enabled: allow no sorting, disable default sorting. TableGetSortSpecs() may return specs where (SpecsCount == 0).")
    PopStyleCompact()

    if ImGui.BeginTable("table_sorting", 4, s.flags, ImVec2(0.0, TEXT_BASE_HEIGHT * 15), 0.0) then
        local CF = ImGuiTableColumnFlags
        -- Declare columns
        -- We use the "user_id" parameter of TableSetupColumn() to specify a user id that will be stored in the sort specifications.
        -- This is so our sort function can identify a column given our own identifier. We could also identify them based on their index!
        -- Demonstrate using a mixture of flags among available sort-related flags:
        -- - ImGuiTableColumnFlags_DefaultSort
        -- - ImGuiTableColumnFlags_NoSort / ImGuiTableColumnFlags_NoSortAscending / ImGuiTableColumnFlags_NoSortDescending
        -- - ImGuiTableColumnFlags_PreferSortAscending / ImGuiTableColumnFlags_PreferSortDescending
        ImGui.TableSetupColumn("ID",       bor(CF.DefaultSort, CF.WidthFixed),            0.0, MyItemColumnID_ID)
        ImGui.TableSetupColumn("Name",     CF.WidthFixed,                                 0.0, MyItemColumnID_Name)
        ImGui.TableSetupColumn("Action",   bor(CF.NoSort, CF.WidthFixed),                 0.0, MyItemColumnID_Action)
        ImGui.TableSetupColumn("Quantity", bor(CF.PreferSortDescending, CF.WidthStretch), 0.0, MyItemColumnID_Quantity)
        ImGui.TableSetupScrollFreeze(0, 1) -- Make row always visible
        ImGui.TableHeadersRow()

        -- Sort our data if sort specs have been changed!
        local sort_specs = ImGui.TableGetSortSpecs()
        if sort_specs and sort_specs.SpecsDirty then
            MyItem_SortWithSortSpecs(sort_specs, items, #items)
            sort_specs.SpecsDirty = false
        end

        -- Demonstrate using clipper for large vertical lists
        local clipper = ImGuiListClipper()
        clipper:Begin(#items)
        while clipper:Step() do
            for row_n = clipper.DisplayStart, clipper.DisplayEnd - 1 do
                -- Display a data item
                local item = items[row_n + 1]
                ImGui.PushID(item.ID)
                ImGui.TableNextRow()
                ImGui.TableNextColumn()
                ImGui.Text("%04d", item.ID)
                ImGui.TableNextColumn()
                ImGui.TextUnformatted(item.Name)
                ImGui.TableNextColumn()
                ImGui.SmallButton("None")
                ImGui.TableNextColumn()
                ImGui.Text("%d", item.Quantity)
                ImGui.PopID()
            end
        end
        ImGui.EndTable()
    end
end

local function Tables_AdvancedOptions(s)
    -- Make the UI compact because there are so many fields
    PushStyleCompact()
    ImGui.PushItemWidth(TEXT_BASE_WIDTH * 28.0)

    if ImGui.TreeNodeEx("Features:", ImGuiTreeNodeFlags.DefaultOpen) then
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Resizable", s.flags, TF.Resizable)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Reorderable", s.flags, TF.Reorderable)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Hideable", s.flags, TF.Hideable)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_Sortable", s.flags, TF.Sortable)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoSavedSettings", s.flags, TF.NoSavedSettings)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_ContextMenuInBody", s.flags, TF.ContextMenuInBody)
        ImGui.TreePop()
    end

    if ImGui.TreeNodeEx("Decorations:", ImGuiTreeNodeFlags.DefaultOpen) then
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_RowBg", s.flags, TF.RowBg)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersV", s.flags, TF.BordersV)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersOuterV", s.flags, TF.BordersOuterV)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersInnerV", s.flags, TF.BordersInnerV)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersH", s.flags, TF.BordersH)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersOuterH", s.flags, TF.BordersOuterH)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_BordersInnerH", s.flags, TF.BordersInnerH)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoBordersInBody", s.flags, TF.NoBordersInBody); ImGui.SameLine(); DemoHelpMarker("Disable vertical borders in columns Body (borders will always appear in Headers)")
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoBordersInBodyUntilResize", s.flags, TF.NoBordersInBodyUntilResize); ImGui.SameLine(); DemoHelpMarker("Disable vertical borders in columns Body until hovered for resize (borders will always appear in Headers)")
        ImGui.TreePop()
    end

    if ImGui.TreeNodeEx("Sizing:", ImGuiTreeNodeFlags.DefaultOpen) then
        s.flags = EditTableSizingFlags(s.flags)
        ImGui.SameLine(); DemoHelpMarker("In the Advanced demo we override the policy of each column so those table-wide settings have less effect that typical.")
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoHostExtendX", s.flags, TF.NoHostExtendX)
        ImGui.SameLine(); DemoHelpMarker("Make outer width auto-fit to columns, overriding outer_size.x value.\n\nOnly available when ScrollX/ScrollY are disabled and Stretch columns are not used.")
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoHostExtendY", s.flags, TF.NoHostExtendY)
        ImGui.SameLine(); DemoHelpMarker("Make outer height stop exactly at outer_size.y (prevent auto-extending table past the limit).\n\nOnly available when ScrollX/ScrollY are disabled. Data below the limit will be clipped and not visible.")
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoKeepColumnsVisible", s.flags, TF.NoKeepColumnsVisible)
        ImGui.SameLine(); DemoHelpMarker("Only available if ScrollX is disabled.")
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_PreciseWidths", s.flags, TF.PreciseWidths)
        ImGui.SameLine(); DemoHelpMarker("Disable distributing remainder width to stretched columns (width allocation on a 100-wide table with 3 columns: Without this flag: 33,33,34. With this flag: 33,33,33). With larger number of columns, resizing will appear to be less smooth.")
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoClip", s.flags, TF.NoClip)
        ImGui.SameLine(); DemoHelpMarker("Disable clipping rectangle for every individual columns (reduce draw command count, items will be able to overflow into other columns). Generally incompatible with ScrollFreeze options.")
        ImGui.TreePop()
    end

    if ImGui.TreeNodeEx("Padding:", ImGuiTreeNodeFlags.DefaultOpen) then
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_PadOuterX", s.flags, TF.PadOuterX)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoPadOuterX", s.flags, TF.NoPadOuterX)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_NoPadInnerX", s.flags, TF.NoPadInnerX)
        ImGui.TreePop()
    end

    if ImGui.TreeNodeEx("Scrolling:", ImGuiTreeNodeFlags.DefaultOpen) then
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_ScrollX", s.flags, TF.ScrollX)
        ImGui.SameLine()
        ImGui.SetNextItemWidth(ImGui.GetFrameHeight())
        s.freeze_cols = ImGui.DragInt("freeze_cols", s.freeze_cols, 0.2, 0, 9, nil, ImGuiSliderFlags.NoInput)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_ScrollY", s.flags, TF.ScrollY)
        ImGui.SameLine()
        ImGui.SetNextItemWidth(ImGui.GetFrameHeight())
        s.freeze_rows = ImGui.DragInt("freeze_rows", s.freeze_rows, 0.2, 0, 9, nil, ImGuiSliderFlags.NoInput)
        ImGui.TreePop()
    end

    if ImGui.TreeNodeEx("Sorting:", ImGuiTreeNodeFlags.DefaultOpen) then
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_SortMulti", s.flags, TF.SortMulti)
        ImGui.SameLine(); DemoHelpMarker("When sorting is enabled: hold shift when clicking headers to sort on multiple column. TableGetSortSpecs() may return specs where (SpecsCount > 1).")
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_SortTristate", s.flags, TF.SortTristate)
        ImGui.SameLine(); DemoHelpMarker("When sorting is enabled: allow no sorting, disable default sorting. TableGetSortSpecs() may return specs where (SpecsCount == 0).")
        ImGui.TreePop()
    end

    if ImGui.TreeNodeEx("Headers:", ImGuiTreeNodeFlags.DefaultOpen) then
        _, s.show_headers = ImGui.Checkbox("show_headers", s.show_headers)
        _, s.flags = ImGui.CheckboxFlags("ImGuiTableFlags_HighlightHoveredColumn", s.flags, TF.HighlightHoveredColumn)
        _, s.columns_base_flags = ImGui.CheckboxFlags("ImGuiTableColumnFlags_AngledHeader", s.columns_base_flags, ImGuiTableColumnFlags.AngledHeader)
        ImGui.SameLine(); DemoHelpMarker("Enable AngledHeader on all columns. Best enabled on selected narrow columns (see \"Angled headers\" section of the demo).")
        ImGui.TreePop()
    end

    if ImGui.TreeNodeEx("Other:", ImGuiTreeNodeFlags.DefaultOpen) then
        _, s.show_wrapped_text = ImGui.Checkbox("show_wrapped_text", s.show_wrapped_text)

        ImGui.DragFloat2("##OuterSize", s.outer_size_value)
        ImGui.SameLine(0.0, ImGui.GetStyle().ItemInnerSpacing.x)
        _, s.outer_size_enabled = ImGui.Checkbox("outer_size", s.outer_size_enabled)
        ImGui.SameLine()
        DemoHelpMarker("If scrolling is disabled (ScrollX and ScrollY not set):\n" ..
            "- The table is output directly in the parent window.\n" ..
            "- OuterSize.x < 0.0f will right-align the table.\n" ..
            "- OuterSize.x = 0.0f will narrow fit the table unless there are any Stretch columns.\n" ..
            "- OuterSize.y then becomes the minimum size for the table, which will extend vertically if there are more rows (unless NoHostExtendY is set).")

        -- From a user point of view we will tend to use 'inner_width' differently depending on whether our table is embedding scrolling.
        -- To facilitate toying with this demo we will actually pass 0.0f to the BeginTable() when ScrollX is disabled.
        s.inner_width_with_scroll = ImGui.DragFloat("inner_width (when ScrollX active)", s.inner_width_with_scroll, 1.0, 0.0, FLT_MAX)

        s.row_min_height = ImGui.DragFloat("row_min_height", s.row_min_height, 1.0, 0.0, FLT_MAX)
        ImGui.SameLine(); DemoHelpMarker("Specify height of the Selectable item.")

        s.items_count = ImGui.DragInt("items_count", s.items_count, 0.1, 0, 9999)
        local contents_type_names = { "Text", "Button", "SmallButton", "FillButton", "Selectable", "Selectable (span row)" }
        if ImGui.Combo then
            s.contents_type = ImGui.Combo("items_type (first column)", s.contents_type, contents_type_names, #contents_type_names)
        else
            NotPorted("Combo")
        end
        ImGui.TreePop()
    end

    ImGui.PopItemWidth()
    PopStyleCompact()
    ImGui.Spacing()
end

-- In this example we'll expose most table flags and settings.
-- For specific flags and settings refer to the corresponding section for more detailed explanation.
-- This section is mostly useful to experiment with combining certain flags or settings with each others.
local function Tables_Advanced()
    IMGUI_DEMO_MARKER("Tables/Advanced")
    local CT_Text, CT_Button, CT_SmallButton, CT_FillButton, CT_Selectable, CT_SelectableSpanRow = 0, 1, 2, 3, 4, 5
    local s = ST.advanced
    if s == nil then
        s = { flags = bor(TF.Resizable, TF.Reorderable, TF.Hideable, TF.Sortable, TF.SortMulti, TF.RowBg, TF.Borders, TF.NoBordersInBody, TF.ScrollX, TF.ScrollY, TF.SizingFixedFit),
              columns_base_flags = ImGuiTableColumnFlags.None, contents_type = CT_SelectableSpanRow,
              freeze_cols = 1, freeze_rows = 1, items_count = #template_items_names * 2,
              outer_size_value = ImVec2(0.0, TEXT_BASE_HEIGHT * 12), row_min_height = 0.0, inner_width_with_scroll = 0.0,
              outer_size_enabled = true, show_headers = true, show_wrapped_text = false,
              items = {}, selection = {}, items_need_sort = false, show_debug_details = false }
        ST.advanced = s
    end
    --ImGui.SetNextItemOpen(true, ImGuiCond.Once) -- FIXME-TABLE: Enabling this results in initial clipped first pass on table which tend to affect column sizing
    if ImGui.TreeNode("Options") then
        Tables_AdvancedOptions(s)
        ImGui.TreePop()
    end

    -- Update item list if we changed the number of items
    local items = s.items
    local selection = s.selection
    if #items ~= s.items_count then
        for n = #items, s.items_count + 1, -1 do items[n] = nil end
        for n = 0, s.items_count - 1 do
            local template_n = n % #template_items_names
            items[n + 1] = MyItem(n, template_items_names[template_n + 1], (template_n == 3) and 10 or (template_n == 4) and 20 or 0) -- Assign default quantities
        end
    end

    local parent_draw_list = ImGui.GetWindowDrawList()
    local parent_draw_list_draw_cmd_count = parent_draw_list.CmdBuffer.Size
    local table_scroll_cur, table_scroll_max -- For debug display
    local table_draw_list = nil  -- "

    -- Submit table
    local flags = s.flags
    local columns_base_flags = s.columns_base_flags
    local inner_width_to_use = Has(flags, TF.ScrollX) and s.inner_width_with_scroll or 0.0
    local CF = ImGuiTableColumnFlags
    if ImGui.BeginTable("table_advanced", 6, flags, s.outer_size_enabled and s.outer_size_value or ImVec2(0, 0), inner_width_to_use) then
        -- Declare columns
        -- We use the "user_id" parameter of TableSetupColumn() to specify a user id that will be stored in the sort specifications.
        -- This is so our sort function can identify a column given our own identifier. We could also identify them based on their index!
        ImGui.TableSetupColumn("ID",          bor(columns_base_flags, CF.DefaultSort, CF.WidthFixed, CF.NoHide), 0.0, MyItemColumnID_ID)
        ImGui.TableSetupColumn("Name",        bor(columns_base_flags, CF.WidthFixed), 0.0, MyItemColumnID_Name)
        ImGui.TableSetupColumn("Action",      bor(columns_base_flags, CF.NoSort, CF.WidthFixed), 0.0, MyItemColumnID_Action)
        ImGui.TableSetupColumn("Quantity",    bor(columns_base_flags, CF.PreferSortDescending), 0.0, MyItemColumnID_Quantity)
        ImGui.TableSetupColumn("Description", bor(columns_base_flags, Has(flags, TF.NoHostExtendX) and 0 or CF.WidthStretch), 0.0, MyItemColumnID_Description)
        ImGui.TableSetupColumn("Hidden",      bor(columns_base_flags, CF.DefaultHide, CF.NoSort))
        ImGui.TableSetupScrollFreeze(s.freeze_cols, s.freeze_rows)

        -- Sort our data if sort specs have been changed!
        local sort_specs = ImGui.TableGetSortSpecs()
        if sort_specs and sort_specs.SpecsDirty then
            s.items_need_sort = true
        end
        if sort_specs and s.items_need_sort and #items > 1 then
            MyItem_SortWithSortSpecs(sort_specs, items, #items)
            sort_specs.SpecsDirty = false
        end
        s.items_need_sort = false

        -- Take note of whether we are currently sorting based on the Quantity field,
        -- we will use this to trigger sorting when we know the data of this column has been modified.
        local sorts_specs_using_quantity = Has(ImGui.TableGetColumnFlags(3), CF.IsSorted)

        -- Show headers
        if s.show_headers and Has(columns_base_flags, CF.AngledHeader) then
            ImGui.TableAngledHeadersRow()
        end
        if s.show_headers then
            ImGui.TableHeadersRow()
        end

        -- Show data
        -- FIXME-TABLE FIXME-NAV: How we can get decent up/down even though we have the buttons here?
        -- Demonstrate using clipper for large vertical lists
        local clipper = ImGuiListClipper()
        clipper:Begin(#items)
        while clipper:Step() do
            for row_n = clipper.DisplayStart, clipper.DisplayEnd - 1 do
                local item = items[row_n + 1]

                local item_is_selected = table.find(selection, item.ID) ~= nil
                ImGui.PushID(item.ID)
                ImGui.TableNextRow(ImGuiTableRowFlags.None, s.row_min_height)

                -- For the demo purpose we can select among different type of items submitted in the first column
                ImGui.TableSetColumnIndex(0)
                local label = string.format("%04d", item.ID)
                local ct = s.contents_type
                if ct == CT_Text then
                    ImGui.TextUnformatted(label)
                elseif ct == CT_Button then
                    ImGui.Button(label)
                elseif ct == CT_SmallButton then
                    ImGui.SmallButton(label)
                elseif ct == CT_FillButton then
                    ImGui.Button(label, ImVec2(-FLT_MIN, 0.0))
                elseif ct == CT_Selectable or ct == CT_SelectableSpanRow then
                    local selectable_flags = (ct == CT_SelectableSpanRow) and bor(ImGuiSelectableFlags.SpanAllColumns, ImGuiSelectableFlags.AllowOverlap) or ImGuiSelectableFlags.None
                    if ImGui.Selectable(label, item_is_selected, selectable_flags, ImVec2(0, s.row_min_height)) then
                        if ImGui.GetIO().KeyCtrl then
                            if item_is_selected then
                                table.remove(selection, table.find(selection, item.ID))
                            else
                                table.insert(selection, item.ID)
                            end
                        else
                            table.clear(selection)
                            table.insert(selection, item.ID)
                        end
                    end
                end

                if ImGui.TableSetColumnIndex(1) then
                    ImGui.TextUnformatted(item.Name)
                end

                -- Here we demonstrate marking our data set as needing to be sorted again if we modified a quantity,
                -- and we are currently sorting on the column showing the Quantity.
                -- To avoid triggering a sort while holding the button, we only trigger it when the button has been released.
                -- You will probably need some extra logic if you want to automatically sort when a specific entry changes.
                if ImGui.TableSetColumnIndex(2) then
                    if ImGui.SmallButton("Chop") then item.Quantity = item.Quantity + 1 end
                    if sorts_specs_using_quantity and ImGui.IsItemDeactivated() then s.items_need_sort = true end
                    ImGui.SameLine()
                    if ImGui.SmallButton("Eat") then item.Quantity = item.Quantity - 1 end
                    if sorts_specs_using_quantity and ImGui.IsItemDeactivated() then s.items_need_sort = true end
                end

                if ImGui.TableSetColumnIndex(3) then
                    ImGui.Text("%d", item.Quantity)
                end

                ImGui.TableSetColumnIndex(4)
                if s.show_wrapped_text then
                    ImGui.TextWrapped("Lorem ipsum dolor sit amet")
                else
                    ImGui.Text("Lorem ipsum dolor sit amet")
                end

                if ImGui.TableSetColumnIndex(5) then
                    ImGui.Text("1234")
                end

                ImGui.PopID()
            end
        end

        -- Store some info to display debug details below
        table_scroll_cur = ImVec2(ImGui.GetScrollX(), ImGui.GetScrollY())
        table_scroll_max = ImVec2(ImGui.GetScrollMaxX(), ImGui.GetScrollMaxY())
        table_draw_list = ImGui.GetWindowDrawList()
        ImGui.EndTable()
    end
    _, s.show_debug_details = ImGui.Checkbox("Debug details", s.show_debug_details)
    if s.show_debug_details and table_draw_list then
        ImGui.SameLine(0.0, 0.0)
        local table_draw_list_draw_cmd_count = table_draw_list.CmdBuffer.Size
        if table_draw_list == parent_draw_list then
            ImGui.Text(": DrawCmd: +%d (in same window)",
                table_draw_list_draw_cmd_count - parent_draw_list_draw_cmd_count)
        else
            ImGui.Text(": DrawCmd: +%d (in child window), Scroll: (%.f/%.f) (%.f/%.f)",
                table_draw_list_draw_cmd_count - 1, table_scroll_cur.x, table_scroll_max.x, table_scroll_cur.y, table_scroll_max.y)
        end
    end
end

local DCS = { selected = -1, h_borders = true, v_borders = true, columns_count = 4, foo = 1.0, bar = 1.0 }

-- Demonstrate old/legacy Columns API!
-- [2020: Columns are under-featured and not maintained. Prefer using the more flexible and powerful BeginTable() API!]
local function DemoWindowColumns()
    local open = ImGui.TreeNode("Legacy Columns API")
    ImGui.SameLine()
    DemoHelpMarker("Columns() is an old API! Prefer using the more flexible and powerful BeginTable() API!")
    if not open then
        return
    end

    -- Basic columns
    if ImGui.TreeNode("Basic") then
        IMGUI_DEMO_MARKER("Columns (legacy API)/Basic")
        ImGui.Text("Without border:")
        ImGui.Columns(3, "mycolumns3", false) -- 3-ways, no border
        ImGui.Separator()
        for n = 0, 13 do
            local label = string.format("Item %d", n)
            if ImGui.Selectable(label) then end
            --if ImGui.Button(label, ImVec2(-FLT_MIN,0.0)) then end
            ImGui.NextColumn()
        end
        ImGui.Columns(1)
        ImGui.Separator()

        ImGui.Text("With border:")
        ImGui.Columns(4, "mycolumns") -- 4-ways, with border
        ImGui.Separator()
        ImGui.Text("ID"); ImGui.NextColumn()
        ImGui.Text("Name"); ImGui.NextColumn()
        ImGui.Text("Path"); ImGui.NextColumn()
        ImGui.Text("Hovered"); ImGui.NextColumn()
        ImGui.Separator()
        local names = { "One", "Two", "Three" }
        local paths = { "/path/one", "/path/two", "/path/three" }
        for i = 0, 2 do
            local label = string.format("%04d", i)
            if ImGui.Selectable(label, DCS.selected == i, ImGuiSelectableFlags.SpanAllColumns) then
                DCS.selected = i
            end
            local hovered = ImGui.IsItemHovered()
            ImGui.NextColumn()
            ImGui.Text(names[i + 1]); ImGui.NextColumn()
            ImGui.Text(paths[i + 1]); ImGui.NextColumn()
            ImGui.Text("%d", hovered and 1 or 0); ImGui.NextColumn()
        end
        ImGui.Columns(1)
        ImGui.Separator()
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Borders") then
        IMGUI_DEMO_MARKER("Columns (legacy API)/Borders")
        -- NB: Future columns API should allow automatic horizontal borders.
        local lines_count = 3
        ImGui.SetNextItemWidth(ImGui.GetFontSize() * 8)
        DCS.columns_count = ImGui.DragInt("##columns_count", DCS.columns_count, 0.1, 2, 10, "%d columns")
        if DCS.columns_count < 2 then
            DCS.columns_count = 2
        end
        ImGui.SameLine()
        _, DCS.h_borders = ImGui.Checkbox("horizontal", DCS.h_borders)
        ImGui.SameLine()
        _, DCS.v_borders = ImGui.Checkbox("vertical", DCS.v_borders)
        ImGui.Columns(DCS.columns_count, nil, DCS.v_borders)
        for i = 0, DCS.columns_count * lines_count - 1 do
            if DCS.h_borders and ImGui.GetColumnIndex() == 0 then
                ImGui.Separator()
            end
            ImGui.PushID(i)
            local c = string.char(string.byte("a") + i)
            ImGui.Text("%s%s%s", c, c, c)
            ImGui.Text("Width %.2f", ImGui.GetColumnWidth())
            ImGui.Text("Avail %.2f", ImGui.GetContentRegionAvail().x)
            ImGui.Text("Offset %.2f", ImGui.GetColumnOffset())
            ImGui.Text("Long text that is likely to clip")
            ImGui.Button("Button", ImVec2(-FLT_MIN, 0.0))
            ImGui.PopID()
            ImGui.NextColumn()
        end
        ImGui.Columns(1)
        if DCS.h_borders then
            ImGui.Separator()
        end
        ImGui.TreePop()
    end

    -- Create multiple items in a same cell before switching to next column
    if ImGui.TreeNode("Mixed items") then
        IMGUI_DEMO_MARKER("Columns (legacy API)/Mixed items")
        ImGui.Columns(3, "mixed")
        ImGui.Separator()

        ImGui.Text("Hello")
        ImGui.Button("Banana")
        ImGui.NextColumn()

        ImGui.Text("ImGui")
        ImGui.Button("Apple")
        DCS.foo = ImGui.InputFloat("red", DCS.foo, 0.05, 0, "%.3f")
        ImGui.Text("An extra line here.")
        ImGui.NextColumn()

        ImGui.Text("Sailor")
        ImGui.Button("Corniflower")
        DCS.bar = ImGui.InputFloat("blue", DCS.bar, 0.05, 0, "%.3f")
        ImGui.NextColumn()

        if ImGui.CollapsingHeader("Category A") then ImGui.Text("Blah blah blah") end ImGui.NextColumn()
        if ImGui.CollapsingHeader("Category B") then ImGui.Text("Blah blah blah") end ImGui.NextColumn()
        if ImGui.CollapsingHeader("Category C") then ImGui.Text("Blah blah blah") end ImGui.NextColumn()
        ImGui.Columns(1)
        ImGui.Separator()
        ImGui.TreePop()
    end

    -- Word wrapping
    if ImGui.TreeNode("Word-wrapping") then
        IMGUI_DEMO_MARKER("Columns (legacy API)/Word-wrapping")
        ImGui.Columns(2, "word-wrapping")
        ImGui.Separator()
        ImGui.TextWrapped("The quick brown fox jumps over the lazy dog.")
        ImGui.TextWrapped("Hello Left")
        ImGui.NextColumn()
        ImGui.TextWrapped("The quick brown fox jumps over the lazy dog.")
        ImGui.TextWrapped("Hello Right")
        ImGui.Columns(1)
        ImGui.Separator()
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Horizontal Scrolling") then
        IMGUI_DEMO_MARKER("Columns (legacy API)/Horizontal Scrolling")
        ImGui.SetNextWindowContentSize(ImVec2(1500.0, 0.0))
        local child_size = ImVec2(0, ImGui.GetFontSize() * 20.0)
        ImGui.BeginChild("##ScrollingRegion", child_size, ImGuiChildFlags.None, ImGuiWindowFlags.HorizontalScrollbar)
        ImGui.Columns(10)

        -- Also demonstrate using clipper for large vertical lists
        local ITEMS_COUNT = 2000
        local clipper = ImGuiListClipper()
        clipper:Begin(ITEMS_COUNT)
        while clipper:Step() do
            for i = clipper.DisplayStart, clipper.DisplayEnd - 1 do
                for j = 0, 9 do
                    ImGui.Text("Line %d Column %d...", i, j)
                    ImGui.NextColumn()
                end
            end
        end
        ImGui.Columns(1)
        ImGui.EndChild()
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Tree") then
        IMGUI_DEMO_MARKER("Columns (legacy API)/Tree")
        ImGui.Columns(2, "tree", true)
        for x = 0, 2 do
            local open1 = ImGui.TreeNode(x, "Node%d", x)
            ImGui.NextColumn()
            ImGui.Text("Node contents")
            ImGui.NextColumn()
            if open1 then
                for y = 0, 2 do
                    local open2 = ImGui.TreeNode(y, "Node%d.%d", x, y)
                    ImGui.NextColumn()
                    ImGui.Text("Node contents")
                    if open2 then
                        ImGui.Text("Even more contents")
                        if ImGui.TreeNode("Tree in column") then
                            ImGui.Text("The quick brown fox jumps over the lazy dog")
                            ImGui.TreePop()
                        end
                    end
                    ImGui.NextColumn()
                    if open2 then
                        ImGui.TreePop()
                    end
                end
                ImGui.TreePop()
            end
        end
        ImGui.Columns(1)
        ImGui.TreePop()
    end

    ImGui.TreePop()
end

local tables_sections = {
    { "Basic", Tables_Basic },
    { "Borders, background", Tables_BordersBackground },
    { "Resizable, stretch", Tables_ResizableStretch },
    { "Resizable, fixed", Tables_ResizableFixed },
    { "Resizable, mixed", Tables_ResizableMixed },
    { "Reorderable, hideable, with headers", Tables_Reorderable },
    { "Padding", Tables_Padding },
    { "Sizing policies", Tables_SizingPolicies },
    { "Vertical scrolling, with clipping", Tables_VerticalScrolling },
    { "Horizontal scrolling", Tables_HorizontalScrolling },
    { "Columns flags", Tables_ColumnsFlags },
    { "Columns widths", Tables_ColumnsWidths },
    { "Nested tables", Tables_Nested },
    { "Row height", Tables_RowHeight },
    { "Outer size", Tables_OuterSize },
    { "Background color", Tables_BackgroundColor },
    { "Tree view", Tables_TreeView },
    { "Item width", Tables_ItemWidth },
    { "Custom headers", Tables_CustomHeaders },
    { "Angled headers", Tables_AngledHeaders },
    { "Context menus", Tables_ContextMenus },
    { "Synced instances", Tables_SyncedInstances },
    { "Sorting", Tables_Sorting },
    { "Advanced", Tables_Advanced },
}

function DemoWindowTables()
    --ImGui.SetNextItemOpen(true, ImGuiCond.Once)
    if not ImGui.CollapsingHeader("Tables & Columns") then
        return
    end

    -- Using those as a base value to create width/height that are factor of the size of our font
    TEXT_BASE_WIDTH = ImGui.CalcTextSize("A").x
    TEXT_BASE_HEIGHT = ImGui.GetTextLineHeightWithSpacing()

    ImGui.PushID("Tables")

    local open_action = -1
    if ImGui.Button("Expand all") then
        open_action = 1
    end
    ImGui.SameLine()
    if ImGui.Button("Collapse all") then
        open_action = 0
    end
    ImGui.SameLine()

    -- Options
    _, ST.disable_indent = ImGui.Checkbox("Disable tree indentation", ST.disable_indent or false)
    ImGui.SameLine()
    DemoHelpMarker("Disable the indenting of tree nodes so demo tables can use the full window width.")
    ImGui.Separator()
    local disable_indent = ST.disable_indent
    if disable_indent then
        ImGui.PushStyleVar(ImGuiStyleVar.IndentSpacing, 0.0)
    end

    -- About Styling of tables
    -- Most settings are configured on a per-table basis via the flags passed to BeginTable() and TableSetupColumns APIs.
    -- There are however a few settings that a shared and part of the ImGuiStyle structure:
    --   style.CellPadding                          -- Padding within each cell
    --   style.Colors[ImGuiCol.TableHeaderBg]       -- Table header background
    --   style.Colors[ImGuiCol.TableBorderStrong]   -- Table outer and header borders
    --   style.Colors[ImGuiCol.TableBorderLight]    -- Table inner borders
    --   style.Colors[ImGuiCol.TableRowBg]          -- Table row background when ImGuiTableFlags_RowBg is enabled (even rows)
    --   style.Colors[ImGuiCol.TableRowBgAlt]       -- Table row background when ImGuiTableFlags_RowBg is enabled (odds rows)

    -- Demos
    for _, sec in ipairs(tables_sections) do
        if open_action ~= -1 then
            ImGui.SetNextItemOpen(open_action ~= 0)
        end
        if ImGui.TreeNode(sec[1]) then
            sec[2]()
            ImGui.TreePop()
        end
    end

    ImGui.PopID()

    DemoWindowColumns()

    if disable_indent then
        ImGui.PopStyleVar()
    end
end
end --[[ imgui_demo_2.lua ]]

do --[[ imgui_demo_apps.lua ]]
-- Demo: Example apps (port of imgui_demo.cpp "Example App" sections). Each ShowExampleAppXXX(p_open) returns the new p_open.
local _
local Buf, BufStr = DemoBuf, DemoBufStr

local function BufSet(buf, str)
    for i = 1, #str do buf[i] = string.byte(str, i) end
    buf[#str + 1] = 0
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Debug Console / ShowExampleAppConsole()
-------------------------------------------------------------------------------

-- Demonstrate creating a simple console window, with scrolling, filtering, completion and history.
-- For the console example, we are using a more C++ like approach of declaring a class to hold both data and functions.
local Console = nil
local function ConsoleNew()
    -- HistoryPos: -1: new line, 0..#History-1 browsing history.
    -- "CLASSIFY" is here to provide the test case where "C"+[tab] completes to "CL" and display multiple matches.
    local c = { InputBuf = Buf("", 256), Items = {}, Commands = { "HELP", "HISTORY", "CLEAR", "CLASSIFY" }, History = {},
        HistoryPos = -1, Filter = ImGuiTextFilter(), AutoScroll = true, ScrollToBottom = false }
    function c:ClearLog() self.Items = {} end
    function c:AddLog(fmt, ...)
        -- FIXME-OPT
        local s = (select("#", ...) > 0) and string.format(fmt, ...) or fmt
        self.Items[#self.Items + 1] = s
    end
    function c:ExecCommand(command_line)
        self:AddLog("# %s\n", command_line)

        -- Insert into history. First find match and delete it so it can be pushed to the back.
        -- This isn't trying to be smart or optimal.
        self.HistoryPos = -1
        for i = #self.History, 1, -1 do
            if string.upper(self.History[i]) == string.upper(command_line) then table.remove(self.History, i); break end
        end
        self.History[#self.History + 1] = command_line

        -- Process command
        local cmd = string.upper(command_line)
        if cmd == "CLEAR" then
            self:ClearLog()
        elseif cmd == "HELP" then
            self:AddLog("Commands:")
            for i = 1, #self.Commands do self:AddLog("- %s", self.Commands[i]) end
        elseif cmd == "HISTORY" then
            local first = #self.History - 10
            for i = math.max(first, 0), #self.History - 1 do self:AddLog("%3d: %s\n", i, self.History[i + 1]) end
        else
            self:AddLog("Unknown command: '%s'\n", command_line)
        end

        -- On command input, we scroll to bottom even if AutoScroll==false
        self.ScrollToBottom = true
    end
    function c:TextEditCallback(data)
        --self:AddLog("cursor: %d, selection: %d-%d", data.CursorPos, data.SelectionStart, data.SelectionEnd)
        if data.EventFlag == ImGuiInputTextFlags.CallbackCompletion then
            -- Example of TEXT COMPLETION

            -- Locate beginning of current word (positions are 0-based offsets into data.Buf)
            local word_end = data.CursorPos
            local word_start = word_end
            while word_start > 0 do
                local ch = data.Buf[word_start]
                if ch == 32 or ch == 9 or ch == 44 or ch == 59 then break end
                word_start = word_start - 1
            end
            local word = ""
            for i = word_start + 1, word_end do word = word .. string.char(data.Buf[i]) end

            -- Build a list of candidates
            local candidates = {}
            for i = 1, #self.Commands do
                if string.upper(string.sub(self.Commands[i], 1, #word)) == string.upper(word) then candidates[#candidates + 1] = self.Commands[i] end
            end
            if #candidates == 0 then
                -- No match
                self:AddLog("No match for \"%s\"!\n", word)
            elseif #candidates == 1 then
                -- Single match. Delete the beginning of the word and replace it entirely so we've got nice casing.
                data:DeleteChars(word_start, word_end - word_start)
                data:InsertChars(data.CursorPos, candidates[1])
                data:InsertChars(data.CursorPos, " ")
            else
                -- Multiple matches. Complete as much as we can..
                -- So inputting "C"+Tab will complete to "CL" then display "CLEAR" and "CLASSIFY" as matches.
                local match_len = word_end - word_start
                while true do
                    local ch, all_match = nil, true
                    for i = 1, #candidates do
                        local cc = string.upper(string.sub(candidates[i], match_len + 1, match_len + 1))
                        if i == 1 then ch = cc elseif ch == "" or ch ~= cc then all_match = false; break end
                    end
                    if not all_match or ch == "" then break end
                    match_len = match_len + 1
                end
                if match_len > 0 then
                    data:DeleteChars(word_start, word_end - word_start)
                    data:InsertChars(data.CursorPos, string.sub(candidates[1], 1, match_len))
                end

                -- List matches
                self:AddLog("Possible matches:\n")
                for i = 1, #candidates do self:AddLog("- %s\n", candidates[i]) end
            end
        elseif data.EventFlag == ImGuiInputTextFlags.CallbackHistory then
            -- Example of HISTORY
            local prev_history_pos = self.HistoryPos
            if data.EventKey == ImGuiKey.UpArrow then
                if self.HistoryPos == -1 then self.HistoryPos = #self.History - 1
                elseif self.HistoryPos > 0 then self.HistoryPos = self.HistoryPos - 1 end
            elseif data.EventKey == ImGuiKey.DownArrow then
                if self.HistoryPos ~= -1 then
                    self.HistoryPos = self.HistoryPos + 1
                    if self.HistoryPos >= #self.History then self.HistoryPos = -1 end
                end
            end

            -- A better implementation would preserve the data on the current input line along with cursor position.
            if prev_history_pos ~= self.HistoryPos then
                local history_str = (self.HistoryPos >= 0) and self.History[self.HistoryPos + 1] or ""
                data:DeleteChars(0, data.BufTextLen)
                data:InsertChars(0, history_str)
            end
        end
        return 0
    end
    function c:Draw(title, p_open)
        ImGui.SetNextWindowSize(ImVec2(520, 600), ImGuiCond.FirstUseEver)
        local visible
        p_open, visible = ImGui.Begin(title, p_open)
        if not visible then ImGui.End(); return p_open end

        -- As a specific feature guaranteed by the library, after calling Begin() the last Item represent the title bar.
        -- So e.g. IsItemHovered() will return true when hovering the title bar.
        -- Here we create a context menu only available from the title bar.
        if ImGui.BeginPopupContextItem() then
            if ImGui.MenuItem("Close Console") then p_open = false end
            ImGui.EndPopup()
        end
        ImGui.TextWrapped("This example implements a console with basic coloring, completion (TAB key) and history (Up/Down keys). A more elaborate implementation may want to store entries along with extra data such as timestamp, emitter, etc.")
        ImGui.TextWrapped("Enter 'HELP' for help.")

        -- TODO: display items starting from the bottom

        if ImGui.SmallButton("Add Debug Text") then self:AddLog("%d some text", #self.Items); self:AddLog("some more text"); self:AddLog("display very important message here!") end
        ImGui.SameLine()
        if ImGui.SmallButton("Add Debug Error") then self:AddLog("[error] something went wrong") end
        ImGui.SameLine()
        if ImGui.SmallButton("Clear") then self:ClearLog() end
        ImGui.SameLine()
        local copy_to_clipboard = ImGui.SmallButton("Copy")
        --local t = 0.0; if ImGui.GetTime() - t > 0.02 then t = ImGui.GetTime(); self:AddLog("Spam %f", t) end

        ImGui.Separator()

        -- Options menu
        if ImGui.BeginPopup("Options") then
            _, self.AutoScroll = ImGui.Checkbox("Auto-scroll", self.AutoScroll)
            ImGui.EndPopup()
        end

        -- Options, Filter
        ImGui.SetNextItemShortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.O), ImGuiInputFlags.Tooltip)
        if ImGui.Button("Options") then ImGui.OpenPopup("Options") end
        ImGui.SameLine()
        ImGui.SetNextItemShortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.F), ImGuiInputFlags.Tooltip)
        ImGui.SetNextItemWidth(-FLT_MIN)
        self.Filter:DrawWithHint("##Filter", "Filter (incl -excl)")
        ImGui.Separator()

        -- Reserve enough left-over height for 1 separator + 1 input text
        local style = ImGui.GetStyle()
        local footer_height_to_reserve = (style.SeparatorSize or 1.0) + style.ItemSpacing.y + ImGui.GetFrameHeightWithSpacing()
        if ImGui.BeginChild("ScrollingRegion", ImVec2(0, -footer_height_to_reserve), ImGuiChildFlags.NavFlattened, ImGuiWindowFlags.HorizontalScrollbar) then
            if ImGui.BeginPopupContextWindow() then
                if ImGui.Selectable("Clear") then self:ClearLog() end
                ImGui.EndPopup()
            end

            -- Display every line as a separate entry so we can change their color or add custom widgets.
            -- If you only want raw text you can use ImGui.TextUnformatted(log.begin(), log.end())
            -- NB- if you have thousands of entries this approach may be too inefficient and may require user-side clipping
            -- to only process visible items. The clipper will automatically measure the height of your first item and then
            -- "seek" to display only items in the visible area.
            -- To use the clipper we can replace your standard loop:
            --      for i = 1, #Items do
            --   With:
            --      local clipper = ImGuiListClipper()
            --      clipper:Begin(#Items)
            --      while clipper:Step() do
            --         for i = clipper.DisplayStart, clipper.DisplayEnd - 1 do
            -- - That your items are evenly spaced (same height)
            -- - That you have cheap random access to your elements (you can access them given their index,
            --   without processing all the ones before)
            -- You cannot this code as-is if a filter is active because it breaks the 'cheap random-access' property.
            -- We would need random-access on the post-filtered list.
            -- A typical application wanting coarse clipping and filtering may want to pre-compute an array of indices
            -- or offsets of items that passed the filtering test, recomputing this array when user changes the filter,
            -- and appending newly elements as they are inserted. This is left as a task to the user until we can manage
            -- to improve this example code!
            -- If your items are of variable height:
            -- - Split them into same height items would be simpler and facilitate random-seeking into your list.
            -- - Consider using manual call to IsRectVisible() and skipping extraneous decoration from your items.
            ImGui.PushStyleVar(ImGuiStyleVar.ItemSpacing, ImVec2(4, 1)) -- Tighten spacing
            if copy_to_clipboard then ImGui.LogToClipboard() end
            for _, item in ipairs(self.Items) do
                if self.Filter:PassFilter(item) then
                    -- Normally you would store more information in your item than just a string.
                    -- (e.g. make Items[] an array of structure, store color/type etc.)
                    local color
                    if string.find(item, "[error]", 1, true) then color = ImVec4(1.0, 0.4, 0.4, 1.0)
                    elseif string.sub(item, 1, 2) == "# " then color = ImVec4(1.0, 0.8, 0.6, 1.0) end
                    if color then ImGui.PushStyleColor(ImGuiCol.Text, color) end
                    ImGui.TextUnformatted(item)
                    if color then ImGui.PopStyleColor() end
                end
            end
            if copy_to_clipboard then ImGui.LogFinish() end

            -- Keep up at the bottom of the scroll region if we were already at the bottom at the beginning of the frame.
            -- Using a scrollbar or mouse-wheel will take away from the bottom edge.
            if self.ScrollToBottom or (self.AutoScroll and ImGui.GetScrollY() >= ImGui.GetScrollMaxY()) then ImGui.SetScrollHereY(1.0) end
            self.ScrollToBottom = false
            ImGui.PopStyleVar()
        end
        ImGui.EndChild()
        ImGui.Separator()

        -- Command-line
        local reclaim_focus = false
        local IT = ImGuiInputTextFlags
        local input_text_flags = bit32.bor(IT.EnterReturnsTrue, IT.EscapeClearsAll, IT.CallbackCompletion, IT.CallbackHistory)
        if ImGui.InputText("Input", self.InputBuf, 256, input_text_flags, function(data) return self:TextEditCallback(data) end) then
            local s = string.gsub(BufStr(self.InputBuf), " +$", "")
            if s ~= "" then self:ExecCommand(s) end
            self.InputBuf[1] = 0
            reclaim_focus = true
        end

        -- Auto-focus on window apparition
        ImGui.SetItemDefaultFocus()
        if reclaim_focus then ImGui.SetKeyboardFocusHere(-1) end -- Auto focus previous widget
        ImGui.End()
        return p_open
    end
    c:AddLog("Welcome to Dear ImGui!")
    return c
end

function ShowExampleAppConsole(p_open)
    Console = Console or ConsoleNew()
    return Console:Draw("Example: Console", p_open)
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Debug Log / ShowExampleAppLog()
-------------------------------------------------------------------------------

-- Usage:
--  local my_log = ExampleAppLog()
--  my_log:AddLog("Hello %d world\n", 123)
--  my_log:Draw("title")
-- Lines are stored as a Lua array (equivalent of Buf + LineOffsets)
local function ExampleAppLog()
    local l = { Lines = { "" }, Filter = ImGuiTextFilter(), AutoScroll = true } -- AutoScroll: Keep scrolling if already at the bottom.
    function l:Clear() self.Lines = { "" } end
    function l:AddLog(fmt, ...)
        local s = (select("#", ...) > 0) and string.format(fmt, ...) or fmt
        local lines = self.Lines
        for part, nl in string.gmatch(s, "([^\n]*)(\n?)") do
            lines[#lines] = lines[#lines] .. part
            if nl ~= "" then lines[#lines + 1] = "" end
            if part == "" and nl == "" then break end
        end
    end
    function l:Draw(title, p_open)
        local visible
        p_open, visible = ImGui.Begin(title, p_open)
        if not visible then ImGui.End(); return p_open end

        -- Options menu
        if ImGui.BeginPopup("Options") then
            _, self.AutoScroll = ImGui.Checkbox("Auto-scroll", self.AutoScroll)
            ImGui.EndPopup()
        end

        -- Main window
        if ImGui.Button("Options") then ImGui.OpenPopup("Options") end
        ImGui.SameLine()
        local clear = ImGui.Button("Clear")
        ImGui.SameLine()
        local copy = ImGui.Button("Copy")
        ImGui.SameLine()
        ImGui.SetNextItemWidth(-FLT_MIN)
        self.Filter:DrawWithHint("##Filter", "Filter (incl -excl)")
        ImGui.Separator()
        if ImGui.BeginChild("scrolling", ImVec2(0, 0), ImGuiChildFlags.None, ImGuiWindowFlags.HorizontalScrollbar) then
            if clear then self:Clear() end
            if copy then ImGui.LogToClipboard() end
            ImGui.PushStyleVar(ImGuiStyleVar.ItemSpacing, ImVec2(0, 0))
            local lines = self.Lines
            if self.Filter:IsActive() then
                -- In this example we don't use the clipper when Filter is enabled.
                -- This is because we don't have random access to the result of our filter.
                -- A real application processing logs with ten of thousands of entries may want to store the result of
                -- search/filter.. especially if the filtering function is not trivial (e.g. reg-exp).
                for line_no = 1, #lines do
                    if self.Filter:PassFilter(lines[line_no]) then ImGui.TextUnformatted(lines[line_no]) end
                end
            else
                -- The simplest and easy way to display the entire buffer:
                --   ImGui.TextUnformatted(buf_begin, buf_end)
                -- And it'll just work. TextUnformatted() has specialization for large blob of text and will fast-forward
                -- to skip non-visible lines. Here we instead demonstrate using the clipper to only process lines that are
                -- within the visible area.
                -- If you have tens of thousands of items and their processing cost is non-negligible, coarse clipping them
                -- on your side is recommended. Using ImGuiListClipper requires
                -- - A) random access into your data
                -- - B) items all being the  same height,
                -- both of which we can handle since we have an array pointing to the beginning of each line of text.
                -- When using the filter (in the block of code above) we don't have random access into the data to display
                -- anymore, which is why we don't use the clipper. Storing or skimming through the search result would make
                -- it possible (and would be recommended if you want to search through tens of thousands of entries).
                local clipper = ImGuiListClipper()
                clipper:Begin(#lines)
                while clipper:Step() do
                    for line_no = clipper.DisplayStart, clipper.DisplayEnd - 1 do ImGui.TextUnformatted(lines[line_no + 1]) end
                end
                clipper:End()
            end
            ImGui.PopStyleVar()
            if copy then ImGui.LogFinish() end

            -- Keep up at the bottom of the scroll region if we were already at the bottom at the beginning of the frame.
            -- Using a scrollbar or mouse-wheel will take away from the bottom edge.
            if self.AutoScroll and ImGui.GetScrollY() >= ImGui.GetScrollMaxY() then ImGui.SetScrollHereY(1.0) end
        end
        ImGui.EndChild()
        ImGui.End()
        return p_open
    end
    return l
end

-- Demonstrate creating a simple log window with basic filtering.
local AppLog, AppLogCounter = nil, 0
function ShowExampleAppLog(p_open)
    AppLog = AppLog or ExampleAppLog()

    -- For the demo: add a debug button _BEFORE_ the normal log window contents
    -- We take advantage of a rarely used feature: multiple calls to Begin()/End() are appending to the _same_ window.
    -- Most of the contents of the window will be added by the log:Draw() call.
    ImGui.SetNextWindowSize(ImVec2(500, 400), ImGuiCond.FirstUseEver)
    p_open = ImGui.Begin("Example: Log", p_open)
    if ImGui.SmallButton("[Debug] Add 5 entries") then
        local categories = { "info", "warn", "error" }
        local words = { "Bumfuzzled", "Cattywampus", "Snickersnee", "Abibliophobia", "Absquatulate", "Nincompoop", "Pauciloquent" }
        for _ = 1, 5 do
            local category = categories[AppLogCounter % #categories + 1]
            local word = words[AppLogCounter % #words + 1]
            AppLog:AddLog("[%05d] [%s] Hello, current time is %.1f, here's a word: '%s'\n", ImGui.GetFrameCount(), category, ImGui.GetTime(), word)
            AppLogCounter = AppLogCounter + 1
        end
    end
    ImGui.End()

    -- Actually call in the regular Log helper (which will Begin() into the same window as we just did)
    return AppLog:Draw("Example: Log", p_open)
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Simple Layout / ShowExampleAppLayout()
-------------------------------------------------------------------------------

-- Demonstrate create a window with multiple child windows.
local LayoutSelected = 0
function ShowExampleAppLayout(p_open)
    ImGui.SetNextWindowSize(ImVec2(500, 440), ImGuiCond.FirstUseEver)
    local visible
    p_open, visible = ImGui.Begin("Example: Simple layout", p_open, ImGuiWindowFlags.MenuBar)
    if visible then
        if ImGui.BeginMenuBar() then
            if ImGui.BeginMenu("File") then
                if ImGui.MenuItem("Close", "Ctrl+W") then p_open = false end
                ImGui.EndMenu()
            end
            ImGui.EndMenuBar()
        end

        -- Left
        ImGui.BeginChild("left pane", ImVec2(150, 0), bit32.bor(ImGuiChildFlags.Borders, ImGuiChildFlags.ResizeX))
        for i = 0, 99 do
            if ImGui.Selectable(string.format("MyObject %d", i), LayoutSelected == i, ImGuiSelectableFlags.SelectOnNav) then LayoutSelected = i end
        end
        ImGui.EndChild()
        ImGui.SameLine()

        -- Right
        ImGui.BeginGroup()
        ImGui.BeginChild("item view", ImVec2(0, -ImGui.GetFrameHeightWithSpacing())) -- Leave room for 1 line below us
        ImGui.Text("MyObject: %d", LayoutSelected)
        ImGui.Separator()
        if ImGui.BeginTabBar("##Tabs", ImGuiTabBarFlags.None) then
            if ImGui.BeginTabItem("Description") then
                ImGui.TextWrapped("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. ")
                ImGui.EndTabItem()
            end
            if ImGui.BeginTabItem("Details") then
                ImGui.Text("ID: 0123456789")
                ImGui.EndTabItem()
            end
            ImGui.EndTabBar()
        end
        ImGui.EndChild()
        if ImGui.Button("Revert") then end
        ImGui.SameLine()
        if ImGui.Button("Save") then end
        ImGui.EndGroup()
    end
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Property Editor / ShowExampleAppPropertyEditor()
-------------------------------------------------------------------------------
-- Some of the interactions are a bit lack-luster:
-- - We would want pressing validating or leaving the filter to somehow restore focus.
-- - We may want more advanced filtering (child nodes) and clipper support: both will need extra work.
-- - We would want to customize some keyboard interactions to easily keyboard navigate between the tree and the properties.
-------------------------------------------------------------------------------

-- ExampleMemberInfo equivalent: field name, data type, component count
local ExampleTreeNodeMemberInfos = {
    { Name = "MyName", DataType = ImGuiDataType.String, DataCount = 1, Field = "Name" },
    { Name = "MyBool", DataType = ImGuiDataType.Bool,   DataCount = 1, Field = "DataMyBool" },
    { Name = "MyInt",  DataType = ImGuiDataType.S32,    DataCount = 1, Field = "DataMyInt" },
    { Name = "MyVec2", DataType = ImGuiDataType.Float,  DataCount = 2, Field = "DataMyVec2" },
}

local PropEd = { Filter = nil, SelectedNode = nil, UseClipper = false, NameBufs = setmetatable({}, { __mode = "k" }) }

-- Custom search filter
-- - Here we apply on root node only.
-- - This does a case insensitive stristr which is pretty heavy. In a real large-scale app you would likely store a filtered list which in turns would be trivial to linearize.
function PropEd:IsNodePassingFilter(node)
    return node.Parent.Parent ~= nil or self.Filter:PassFilter(node.Name)
end

-- To support node with same name we incorporate node.UID into the item ID.
-- (this would more naturally be done using PushID(node.UID) + TreeNodeEx(node.Name, tree_flags),
--   but it would require in DrawClippedTreeNodeAndAdvanceToNext() to add PushID() before TreePush(), and PopID() after TreePop(),
--   so instead we use TreeNodeEx(node.UID, tree_flags, "%s", node.Name) here)
function PropEd:DrawTreeNode(node)
    local TN = ImGuiTreeNodeFlags
    ImGui.TableNextRow()
    ImGui.TableNextColumn()
    -- OpenOnArrow | OpenOnDoubleClick: Standard opening mode as we are likely to want to add selection afterwards
    -- NavLeftJumpsToParent: Left arrow support
    -- SpanFullWidth: Span full width for easier mouse reach
    -- DrawLinesToNodes: Always draw hierarchy outlines
    local tree_flags = bit32.bor(TN.OpenOnArrow, TN.OpenOnDoubleClick, TN.NavLeftJumpsToParent, TN.SpanFullWidth, TN.DrawLinesToNodes)
    if node == self.SelectedNode then tree_flags = bit32.bor(tree_flags, TN.Selected) end -- Draw selection highlight
    if #node.Childs == 0 then tree_flags = bit32.bor(tree_flags, TN.Leaf, TN.Bullet, TN.NoTreePushOnOpen) end -- Use _NoTreePushOnOpen + set is_open=false to avoid unnecessarily push/pop on leaves.
    if node.DataMyBool == false then ImGui.PushStyleColor(ImGuiCol.Text, ImGui.GetStyle().Colors[ImGuiCol.TextDisabled]) end
    ImGui.SetNextItemStorageID(node.UID) -- Use node.UID as storage id
    local is_open = ImGui.TreeNodeEx(node.UID, tree_flags, "%s", node.Name)
    if #node.Childs == 0 then is_open = false end
    if node.DataMyBool == false then ImGui.PopStyleColor() end
    if ImGui.IsItemFocused() then self.SelectedNode = node end
    return is_open
end

-- Basic version, recursive. This is how you would generally draw a tree.
-- - Simple but going to be noticeably costly if you have a large amount of nodes as DrawTreeNode() is called for all of them.
-- - On my desktop PC (2020), for 10K nodes in an optimized build this takes ~1.2 ms
-- - Unlike arrays or grids which are very easy to clip, trees are currently more difficult to clip.
function PropEd:DrawTree(node)
    for _, child in ipairs(node.Childs) do
        if self:IsNodePassingFilter(child) and self:DrawTreeNode(child) then
            self:DrawTree(child)
            ImGui.TreePop()
        end
    end
end

function PropEd:DrawClippedTreeNodeAndAdvanceToNext(clipper, node)
    if self:IsNodePassingFilter(node) then
        -- Draw node if within visible range
        local is_open
        if clipper.UserIndex >= clipper.DisplayStart and clipper.UserIndex < clipper.DisplayEnd then
            is_open = self:DrawTreeNode(node)
        else
            is_open = (#node.Childs > 0 and ImGui.TreeNodeGetOpen(node.UID))
            if is_open then ImGui.TreePush(node.Name) end
        end
        clipper.UserIndex = clipper.UserIndex + 1

        -- Next node: recurse into childs
        if is_open then return node.Childs[1] end
    end

    -- Next node: next sibling, otherwise move back to parent
    while node ~= nil do
        if node.IndexInParent + 1 < #node.Parent.Childs then
            return node.Parent.Childs[node.IndexInParent + 2]
        end
        node = node.Parent
        if node.Parent == nil then break end
        ImGui.TreePop()
    end
    return nil
end

-- More advanced version. Use a alternative clipping technique: fast-forwarding through non-visible chunks.
-- - On my desktop PC (2020), for 10K nodes in an optimized build this takes ~0.1 ms
--   (in ExampleTree_CreateDemoTree(), change 'ROOT_ITEMS_COUNT = 10000' to try with this amount of root nodes).
-- - 1. Use clipper with indeterminate count (items_count = INT_MAX): we need to call SeekCursorForItem() at the end once we know the count.
-- - 2. Use SetNextItemStorageID() to specify ID used for open/close storage, making it easy to call TreeNodeGetOpen() on any arbitrary node.
-- - 3. Linearize tree during traversal: our tree data structure makes it easy to access sibling and parents.
-- - Unlike clipping for a regular array or grid which may be done using random access limited to visible areas,
--   this technique requires traversing most accessible nodes. This could be made more optimal with extra work,
--   but this is a decent simplicity<>speed trade-off.
-- See https://github.com/ocornut/imgui/issues/3823 for discussions about this.
function PropEd:DrawClippedTree(root_node)
    local node = root_node.Childs[1] -- First node
    local clipper = ImGuiListClipper()
    clipper:Begin(INT_MAX)
    while clipper:Step() do
        while clipper.UserIndex < clipper.DisplayEnd and node ~= nil do
            node = self:DrawClippedTreeNodeAndAdvanceToNext(clipper, node)
        end
    end

    -- Keep going to count nodes and submit final count so we have a reliable scrollbar.
    -- - One could consider caching this value and only refreshing it occasionally e.g. window is focused and an action occurs.
    -- - Incorrect but cheap approximation would be to use 'clipper_current_idx = IM_MAX(clipper_current_idx, #root_node.Childs)' instead.
    -- - If either of those is implemented, the general cost will approach zero when scrolling is at the top of the tree.
    while node ~= nil do
        node = self:DrawClippedTreeNodeAndAdvanceToNext(clipper, node)
    end
    --clipper.UserIndex = math.max(clipper.UserIndex, #root_node.Childs) -- <-- Cheap approximation instead of while() loop above.
    clipper:SeekCursorForItem(clipper.UserIndex)
end

function PropEd:Draw(root_node)
    self.Filter = self.Filter or ImGuiTextFilter()
    -- Left side: draw tree
    -- - Currently using a table to benefit from RowBg feature
    -- - Our tree node are all of equal height, facilitating the use of a clipper.
    if ImGui.BeginChild("##tree", ImVec2(300, 0), bit32.bor(ImGuiChildFlags.ResizeX, ImGuiChildFlags.Borders, ImGuiChildFlags.NavFlattened)) then
        ImGui.PushItemFlag(ImGuiItemFlags.NoNavDefaultFocus, true)
        _, self.UseClipper = ImGui.Checkbox("Use Clipper", self.UseClipper)
        ImGui.SameLine()
        ImGui.Text("(%d root nodes)", #root_node.Childs)
        ImGui.SetNextItemWidth(-FLT_MIN)
        ImGui.SetNextItemShortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.F), ImGuiInputFlags.Tooltip)
        if ImGui.InputTextWithHint("##Filter", "incl -excl", self.Filter.InputBuf, 256, ImGuiInputTextFlags.EscapeClearsAll) then
            self.Filter:Build()
        end
        ImGui.PopItemFlag()
        if ImGui.BeginTable("##list", 1, ImGuiTableFlags.RowBg) then
            if self.UseClipper then self:DrawClippedTree(root_node) else self:DrawTree(root_node) end
            ImGui.EndTable()
        end
    end
    ImGui.EndChild()

    -- Right side: draw properties
    ImGui.SameLine()

    ImGui.BeginGroup() -- Lock X position
    local node = self.SelectedNode
    if node then
        ImGui.Text("%s", node.Name)
        ImGui.TextDisabled("UID: 0x%08X", node.UID)
        ImGui.Separator()
        if ImGui.BeginTable("##properties", 2, bit32.bor(ImGuiTableFlags.Resizable, ImGuiTableFlags.ScrollY)) then
            -- Push object ID after we entered the table, so table is shared for all objects
            ImGui.PushID(node.UID)
            ImGui.TableSetupColumn("", ImGuiTableColumnFlags.WidthFixed)
            ImGui.TableSetupColumn("", ImGuiTableColumnFlags.WidthStretch, 2.0) -- Default twice larger
            if node.HasData then
                -- In a typical application, the structure description would be derived from a data-driven system.
                -- - We try to mimic this with our ExampleMemberInfo structure and the ExampleTreeNodeMemberInfos[] array.
                -- - Limits and some details are hard-coded to simplify the demo.
                for _, field_desc in ipairs(ExampleTreeNodeMemberInfos) do
                    ImGui.TableNextRow()
                    ImGui.PushID(field_desc.Name)
                    ImGui.TableNextColumn()
                    ImGui.AlignTextToFramePadding()
                    ImGui.TextUnformatted(field_desc.Name)
                    ImGui.TableNextColumn()
                    local DT = ImGuiDataType
                    if field_desc.DataType == DT.Bool then
                        _, node[field_desc.Field] = ImGui.Checkbox("##Editor", node[field_desc.Field])
                    elseif field_desc.DataType == DT.S32 then
                        ImGui.SetNextItemWidth(-FLT_MIN)
                        node[field_desc.Field] = ImGui.DragScalar("##Editor", DT.S32, node[field_desc.Field], 1.0, INT_MIN or -2147483648, INT_MAX)
                    elseif field_desc.DataType == DT.Float then
                        ImGui.SetNextItemWidth(-FLT_MIN)
                        ImGui.SliderScalarN("##Editor", DT.Float, node[field_desc.Field], field_desc.DataCount, 0.0, 1.0)
                    elseif field_desc.DataType == DT.String then
                        local b = self.NameBufs[node]
                        if b == nil then b = Buf(node.Name, 28); self.NameBufs[node] = b end
                        if ImGui.InputText("##Editor", b, 28) then node.Name = BufStr(b) end
                    end
                    ImGui.PopID()
                end
            end
            ImGui.PopID()
            ImGui.EndTable()
        end
    end
    ImGui.EndGroup()
end

-- Demonstrate creating a simple property editor.
local DemoTree = nil
function ShowExampleAppPropertyEditor(p_open, demo_data)
    ImGui.SetNextWindowSize(ImVec2(430, 450), ImGuiCond.FirstUseEver)
    local visible
    p_open, visible = ImGui.Begin("Example: Property editor", p_open)
    if not visible then ImGui.End(); return p_open end
    if demo_data and demo_data.DemoTree == nil then demo_data.DemoTree = ExampleTree_CreateDemoTree() end
    DemoTree = (demo_data and demo_data.DemoTree) or DemoTree or ExampleTree_CreateDemoTree()
    PropEd:Draw(DemoTree)
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Long Text / ShowExampleAppLongText()
-------------------------------------------------------------------------------

-- Demonstrate/test rendering huge amount of text, and the incidence of clipping.
local LT = { test_type = 0, log = {}, lines = 0, bytes = 0 }
function ShowExampleAppLongText(p_open)
    ImGui.SetNextWindowSize(ImVec2(520, 600), ImGuiCond.FirstUseEver)
    local visible
    p_open, visible = ImGui.Begin("Example: Long text display", p_open)
    if not visible then ImGui.End(); return p_open end
    ImGui.Text("Printing unusually long amount of text.")
    LT.test_type = ImGui.Combo("Test type", LT.test_type, "Single call to TextUnformatted()\0Multiple calls to Text(), clipped\0Multiple calls to Text(), not clipped (slow)\0")
    ImGui.Text("Buffer contents: %d lines, %d bytes", LT.lines, LT.bytes)
    if ImGui.Button("Clear") then LT.log = {}; LT.lines = 0; LT.bytes = 0; LT.text = nil end
    ImGui.SameLine()
    if ImGui.Button("Add 1000 lines") then
        for i = 0, 999 do
            local line = string.format("%i The quick brown fox jumps over the lazy dog\n", LT.lines + i)
            LT.log[#LT.log + 1] = line
            LT.bytes = LT.bytes + #line
        end
        LT.lines = LT.lines + 1000
        LT.text = nil
    end
    ImGui.BeginChild("Log")
    if LT.test_type == 0 then
        -- Single call to TextUnformatted() with a big buffer
        LT.text = LT.text or table.concat(LT.log)
        ImGui.TextUnformatted(LT.text)
    elseif LT.test_type == 1 then
        -- Multiple calls to Text(), manually coarsely clipped - demonstrate how to use the ImGuiListClipper helper.
        ImGui.PushStyleVar(ImGuiStyleVar.ItemSpacing, ImVec2(0, 0))
        local clipper = ImGuiListClipper()
        clipper:Begin(LT.lines)
        while clipper:Step() do
            for i = clipper.DisplayStart, clipper.DisplayEnd - 1 do ImGui.Text("%i The quick brown fox jumps over the lazy dog", i) end
        end
        ImGui.PopStyleVar()
    else
        -- Multiple calls to Text(), not clipped (slow)
        ImGui.PushStyleVar(ImGuiStyleVar.ItemSpacing, ImVec2(0, 0))
        for i = 0, LT.lines - 1 do ImGui.Text("%i The quick brown fox jumps over the lazy dog", i) end
        ImGui.PopStyleVar()
    end
    ImGui.EndChild()
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Auto Resize / ShowExampleAppAutoResize()
-------------------------------------------------------------------------------

-- Demonstrate creating a window which gets auto-resized according to its content.
local AutoResizeLines = 10
function ShowExampleAppAutoResize(p_open)
    local visible
    p_open, visible = ImGui.Begin("Example: Auto-resizing window", p_open, ImGuiWindowFlags.AlwaysAutoResize)
    if not visible then ImGui.End(); return p_open end
    ImGui.TextUnformatted("Window will resize every-frame to the size of its content.\nNote that you probably don't want to query the window size to\noutput your content because that would create a feedback loop.")
    AutoResizeLines = ImGui.SliderInt("Number of lines", AutoResizeLines, 1, 20)
    for i = 0, AutoResizeLines - 1 do ImGui.Text("%sThis is line %d", string.rep(" ", i * 4), i) end -- Pad with space to extend size horizontally
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Constrained Resize / ShowExampleAppConstrainedResize()
-------------------------------------------------------------------------------

-- Demonstrate creating a window with custom resize constraints.
-- Note that size constraints currently don't work on a docked window (when in 'docking' branch)
-- Options
local CR = { auto_resize = false, window_padding = true, type = 6, display_lines = 10 } -- type 6: Aspect Ratio
function ShowExampleAppConstrainedResize(p_open)
    -- Helper functions to demonstrate programmatic constraints
    -- FIXME: This doesn't take account of decoration size (e.g. title bar), library should make this easier.
    -- FIXME: None of the three demos works consistently when resizing from borders.
    local function AspectRatio(data) data.DesiredSize.y = math.floor(data.DesiredSize.x / data.UserData) end
    local function Square(data) local m = math.max(data.DesiredSize.x, data.DesiredSize.y); data.DesiredSize.x = m; data.DesiredSize.y = m end
    local function Step(data)
        local step = data.UserData
        data.DesiredSize = ImVec2(math.floor(data.DesiredSize.x / step + 0.5) * step, math.floor(data.DesiredSize.y / step + 0.5) * step)
    end
    local test_desc = { "Between 100x100 and 500x500", "At least 100x100", "Resize vertical + lock current width", "Resize horizontal + lock current height",
        "Width Between 400 and 500", "Height at least 400", "Custom: Aspect Ratio 16:9", "Custom: Always Square", "Custom: Fixed Steps (100)" }
    -- Submit constraint
    local t = CR.type
    if t == 0 then ImGui.SetNextWindowSizeConstraints(ImVec2(100, 100), ImVec2(500, 500)) end         -- Between 100x100 and 500x500
    if t == 1 then ImGui.SetNextWindowSizeConstraints(ImVec2(100, 100), ImVec2(FLT_MAX, FLT_MAX)) end -- Width > 100, Height > 100
    if t == 2 then ImGui.SetNextWindowSizeConstraints(ImVec2(-1, 0), ImVec2(-1, FLT_MAX)) end         -- Resize vertical + lock current width
    if t == 3 then ImGui.SetNextWindowSizeConstraints(ImVec2(0, -1), ImVec2(FLT_MAX, -1)) end         -- Resize horizontal + lock current height
    if t == 4 then ImGui.SetNextWindowSizeConstraints(ImVec2(400, -1), ImVec2(500, -1)) end           -- Width Between and 400 and 500
    if t == 5 then ImGui.SetNextWindowSizeConstraints(ImVec2(-1, 400), ImVec2(-1, FLT_MAX)) end       -- Height at least 400
    if t == 6 then ImGui.SetNextWindowSizeConstraints(ImVec2(0, 0), ImVec2(FLT_MAX, FLT_MAX), AspectRatio, 16.0 / 9.0) end -- Aspect ratio
    if t == 7 then ImGui.SetNextWindowSizeConstraints(ImVec2(0, 0), ImVec2(FLT_MAX, FLT_MAX), Square) end                  -- Always Square
    if t == 8 then ImGui.SetNextWindowSizeConstraints(ImVec2(0, 0), ImVec2(FLT_MAX, FLT_MAX), Step, 100.0) end             -- Fixed Step

    -- Submit window
    if not CR.window_padding then ImGui.PushStyleVar(ImGuiStyleVar.WindowPadding, ImVec2(0.0, 0.0)) end
    local window_flags = CR.auto_resize and ImGuiWindowFlags.AlwaysAutoResize or 0
    local window_open
    p_open, window_open = ImGui.Begin("Example: Constrained Resize", p_open, window_flags)
    if not CR.window_padding then ImGui.PopStyleVar() end
    if window_open then
        if ImGui.GetIO().KeyShift then
            -- Display a dummy viewport (in your real app you would likely use ImageButton() to display a texture)
            local avail_size = ImGui.GetContentRegionAvail()
            local pos = ImGui.GetCursorScreenPos()
            ImGui.ColorButton("viewport", ImVec4(0.5, 0.2, 0.5, 1.0), bit32.bor(ImGuiColorEditFlags.NoTooltip, ImGuiColorEditFlags.NoDragDrop), avail_size)
            ImGui.SetCursorScreenPos(ImVec2(pos.x + 10, pos.y + 10))
            ImGui.Text("%.2f x %.2f", avail_size.x, avail_size.y)
        else
            ImGui.Text("(Hold Shift to display a dummy viewport)")
            if ImGui.IsWindowDocked() then ImGui.Text("Warning: Sizing Constraints won't work if the window is docked!") end
            if ImGui.Button("Set 200x200") then ImGui.SetWindowSize(ImVec2(200, 200)) end ImGui.SameLine()
            if ImGui.Button("Set 500x500") then ImGui.SetWindowSize(ImVec2(500, 500)) end ImGui.SameLine()
            if ImGui.Button("Set 800x200") then ImGui.SetWindowSize(ImVec2(800, 200)) end
            ImGui.SetNextItemWidth(ImGui.GetFontSize() * 20)
            CR.type = ImGui.Combo("Constraint", CR.type, test_desc, #test_desc)
            ImGui.SetNextItemWidth(ImGui.GetFontSize() * 20)
            CR.display_lines = ImGui.DragInt("Lines", CR.display_lines, 0.2, 1, 100)
            _, CR.auto_resize = ImGui.Checkbox("Auto-resize", CR.auto_resize)
            _, CR.window_padding = ImGui.Checkbox("Window padding", CR.window_padding)
            for i = 0, CR.display_lines - 1 do ImGui.Text("%sHello, sailor! Making this line long enough for the example.", string.rep(" ", i * 4)) end
        end
    end
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Simple overlay / ShowExampleAppSimpleOverlay()
-------------------------------------------------------------------------------

-- Demonstrate creating a simple static window with no decoration
-- + a context-menu to choose which corner of the screen to use.
local OverlayLocation = 0
function ShowExampleAppSimpleOverlay(p_open)
    local io = ImGui.GetIO()
    local W = ImGuiWindowFlags
    local window_flags = bit32.bor(W.NoDecoration, W.NoDocking, W.AlwaysAutoResize, W.NoSavedSettings, W.NoFocusOnAppearing, W.NoNav)
    if OverlayLocation >= 0 then
        local PAD = 10.0
        local viewport = ImGui.GetMainViewport()
        local work_pos, work_size = viewport.WorkPos, viewport.WorkSize -- Use work area to avoid menu-bar/task-bar, if any!
        local right, bottom = OverlayLocation % 2 == 1, OverlayLocation >= 2
        local window_pos = ImVec2(right and (work_pos.x + work_size.x - PAD) or (work_pos.x + PAD), bottom and (work_pos.y + work_size.y - PAD) or (work_pos.y + PAD))
        local window_pos_pivot = ImVec2(right and 1.0 or 0.0, bottom and 1.0 or 0.0)
        ImGui.SetNextWindowPos(window_pos, ImGuiCond.Always, window_pos_pivot)
        ImGui.SetNextWindowViewport(viewport.ID)
        window_flags = bit32.bor(window_flags, W.NoMove)
    elseif OverlayLocation == -2 then
        -- Center window
        ImGui.SetNextWindowPos(ImGui.GetMainViewport():GetCenter(), ImGuiCond.Always, ImVec2(0.5, 0.5))
        window_flags = bit32.bor(window_flags, W.NoMove)
    end
    ImGui.SetNextWindowBgAlpha(0.35) -- Transparent background
    local visible
    p_open, visible = ImGui.Begin("Example: Simple overlay", p_open, window_flags)
    if visible then
        ImGui.Text("Simple overlay\n(right-click to change position)")
        ImGui.Separator()
        if ImGui.IsMousePosValid() then ImGui.Text("Mouse Position: (%.1f,%.1f)", io.MousePos.x, io.MousePos.y) else ImGui.Text("Mouse Position: <invalid>") end
        if ImGui.BeginPopupContextWindow() then
            if ImGui.MenuItem("Custom", nil, OverlayLocation == -1) then OverlayLocation = -1 end
            if ImGui.MenuItem("Center", nil, OverlayLocation == -2) then OverlayLocation = -2 end
            if ImGui.MenuItem("Top-left", nil, OverlayLocation == 0) then OverlayLocation = 0 end
            if ImGui.MenuItem("Top-right", nil, OverlayLocation == 1) then OverlayLocation = 1 end
            if ImGui.MenuItem("Bottom-left", nil, OverlayLocation == 2) then OverlayLocation = 2 end
            if ImGui.MenuItem("Bottom-right", nil, OverlayLocation == 3) then OverlayLocation = 3 end
            if p_open ~= nil and ImGui.MenuItem("Close") then p_open = false end
            ImGui.EndPopup()
        end
    end
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Fullscreen window / ShowExampleAppFullscreen()
-------------------------------------------------------------------------------

-- Demonstrate creating a window covering the entire screen/viewport
local FS = { use_work_area = true, flags = bit32.bor(ImGuiWindowFlags.NoDecoration, ImGuiWindowFlags.NoMove, ImGuiWindowFlags.NoSavedSettings) }
function ShowExampleAppFullscreen(p_open)
    -- We demonstrate using the full viewport area or the work area (without menu-bars, task-bars etc.)
    -- Based on your use case you may want one or the other.
    local viewport = ImGui.GetMainViewport()
    ImGui.SetNextWindowPos(FS.use_work_area and viewport.WorkPos or viewport.Pos)
    ImGui.SetNextWindowSize(FS.use_work_area and viewport.WorkSize or viewport.Size)
    local visible
    p_open, visible = ImGui.Begin("Example: Fullscreen window", p_open, FS.flags)
    if visible then
        _, FS.use_work_area = ImGui.Checkbox("Use work area instead of main area", FS.use_work_area)
        ImGui.SameLine()
        HelpMarker("Main Area = entire viewport,\nWork Area = entire viewport minus sections used by the main menu bars, task bars etc.\n\nEnable the main-menu bar in Examples menu to see the difference.")
        local W = ImGuiWindowFlags
        _, FS.flags = ImGui.CheckboxFlags("ImGuiWindowFlags_NoBackground", FS.flags, W.NoBackground)
        _, FS.flags = ImGui.CheckboxFlags("ImGuiWindowFlags_NoDecoration", FS.flags, W.NoDecoration)
        ImGui.Indent()
        _, FS.flags = ImGui.CheckboxFlags("ImGuiWindowFlags_NoTitleBar", FS.flags, W.NoTitleBar)
        _, FS.flags = ImGui.CheckboxFlags("ImGuiWindowFlags_NoCollapse", FS.flags, W.NoCollapse)
        _, FS.flags = ImGui.CheckboxFlags("ImGuiWindowFlags_NoScrollbar", FS.flags, W.NoScrollbar)
        ImGui.Unindent()
        if p_open ~= nil and ImGui.Button("Close this window") then p_open = false end
    end
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Manipulating Window Titles / ShowExampleAppWindowTitles()
-------------------------------------------------------------------------------

-- Demonstrate the use of "##" and "###" in identifiers to manipulate ID generation.
-- This applies to all regular items as well.
-- Read FAQ section "How can I have multiple widgets with the same label?" for details.
function ShowExampleAppWindowTitles(p_open)
    local viewport = ImGui.GetMainViewport()
    local base_pos = viewport.Pos

    -- By default, Windows are uniquely identified by their title.
    -- You can use the "##" and "###" markers to manipulate the display/ID.

    -- Using "##" to display same title but have unique identifier.
    ImGui.SetNextWindowPos(ImVec2(base_pos.x + 100, base_pos.y + 100), ImGuiCond.FirstUseEver)
    ImGui.Begin("Same title as another window##1")
    ImGui.Text("This is window 1.\nMy title is the same as window 2, but my identifier is unique.")
    ImGui.End()
    ImGui.SetNextWindowPos(ImVec2(base_pos.x + 100, base_pos.y + 200), ImGuiCond.FirstUseEver)
    ImGui.Begin("Same title as another window##2")
    ImGui.Text("This is window 2.\nMy title is the same as window 1, but my identifier is unique.")
    ImGui.End()

    -- Using "###" to display a changing title but keep a static identifier "AnimatedTitle"
    local spin = "|/-\\"
    local k = math.floor(ImGui.GetTime() / 0.25) % 4 + 1
    local buf = string.format("Animated title %s %d###AnimatedTitle", string.sub(spin, k, k), ImGui.GetFrameCount())
    ImGui.SetNextWindowPos(ImVec2(base_pos.x + 100, base_pos.y + 300), ImGuiCond.FirstUseEver)
    ImGui.Begin(buf)
    ImGui.Text("This window has a changing title.")
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Custom Rendering using ImDrawList API / ShowExampleAppCustomRendering()
-------------------------------------------------------------------------------

-- See our Wiki guides:
-- - ImDrawList Vector Rendering Reference: https://github.com/ocornut/imgui/wiki/Draw-List
-- - Pixel Perfect Anti-aliased Rendering: https://github.com/ocornut/imgui/wiki/Pixel-Perfect-Rendering
-- - How Anti-aliased Polyline Rendering is Implemented: https://github.com/ocornut/imgui/wiki/Polyline-Rendering

local CRS = { sz = 42.0, base_rounding = 8.0, base_thickness = 3.0, animate_rounding = false, animate_thickness = false, ngon_segments = 6,
    circle_override = false, circle_override_v = 12, curve_override = false, curve_override_v = 8,
    colf_stroke = ImVec4(1.000, 0.384, 0.169, 1.000), colf_fill = ImVec4(0.416, 0.378, 0.420, 1.000),
    points = {}, scrolling = ImVec2(0.0, 0.0), opt_enable_grid = true, opt_enable_context_menu = true, adding_line = false,
    draw_bg = true, draw_fg = true }

local function CustomRenderingPrimitives()
    local s = CRS
    ImGui.PushItemWidth(-ImGui.GetFontSize() * 15)
    ImGui.PushItemFlag(ImGuiItemFlags.LiveEditOnInput, true)
    local draw_list = ImGui.GetWindowDrawList()

    -- Draw gradients
    -- (note that those are currently exacerbating our sRGB/Linear issues)
    -- Calling ImGui.GetColorU32() multiplies the given colors by the current Style Alpha, but you may pass the IM_COL32() directly as well..
    ImGui.Text("Gradients")
    local gradient_size = ImVec2(ImGui.CalcItemWidth(), ImGui.GetFrameHeight())
    ImGui.InvisibleButton("##gradient1", gradient_size)
    local col_a, col_b = ImGui.GetColorU32(IM_COL32(0, 0, 0, 255), nil, true), ImGui.GetColorU32(IM_COL32(255, 255, 255, 255), nil, true)
    draw_list:AddRectFilledMultiColor(ImGui.GetItemRectMin(), ImGui.GetItemRectMax(), col_a, col_b, col_b, col_a)
    ImGui.InvisibleButton("##gradient2", gradient_size)
    col_a, col_b = ImGui.GetColorU32(IM_COL32(0, 255, 0, 255), nil, true), ImGui.GetColorU32(IM_COL32(255, 0, 0, 255), nil, true)
    draw_list:AddRectFilledMultiColor(ImGui.GetItemRectMin(), ImGui.GetItemRectMax(), col_a, col_b, col_b, col_a)

    -- Draw a bunch of primitives
    ImGui.Text("All primitives")
    s.sz = ImGui.DragFloat("Size", s.sz, 0.2, 0.2, 100.0, "%.0f")
    local t = ImGui.GetTime()
    local rounding_wave = 1.0 - math.abs((t % 3.0) * (2.0 / 3.0) - 1.0)
    local rounding = s.animate_rounding and (math.floor(rounding_wave * s.base_rounding * 10.0) / 10.0) or s.base_rounding -- Sub-integer rounding works but has discontinuities in small values, so best disable we
    s.base_rounding = ImGui.DragFloat("Rounding", s.base_rounding, 0.02, 0.0, 32.0, "%.1f"); ImGui.SameLine()
    _, s.animate_rounding = ImGui.Checkbox("Animate##rounding", s.animate_rounding); ImGui.SameLine()
    ImGui.Text("%.2f", rounding)
    local thickness_wave = 1.0 - math.abs((t % 5.0) * (2.0 / 5.0) - 1.0)
    local thickness = s.animate_thickness and (thickness_wave * s.base_thickness) or s.base_thickness
    s.base_thickness = ImGui.DragFloat("Thickness", s.base_thickness, 0.02, 0.0, 32.0, "%.02f"); ImGui.SameLine()
    _, s.animate_thickness = ImGui.Checkbox("Animate##thickness", s.animate_thickness); ImGui.SameLine()
    ImGui.Text("%.2f", thickness)
    s.ngon_segments = ImGui.SliderInt("N-gon sides", s.ngon_segments, 3, 12)
    local changed
    _, s.circle_override = ImGui.Checkbox("##CircleSegmentOverride", s.circle_override)
    ImGui.SameLine(0.0, ImGui.GetStyle().ItemInnerSpacing.x)
    s.circle_override_v, changed = ImGui.SliderInt("Circle segments override", s.circle_override_v, 3, 30)
    s.circle_override = s.circle_override or changed
    _, s.curve_override = ImGui.Checkbox("##CurvesSegmentOverride", s.curve_override)
    ImGui.SameLine(0.0, ImGui.GetStyle().ItemInnerSpacing.x)
    s.curve_override_v, changed = ImGui.SliderInt("Curves segments override", s.curve_override_v, 3, 30)
    s.curve_override = s.curve_override or changed
    ImGui.ColorEdit4("Stroke Color", s.colf_stroke)
    ImGui.ColorEdit4("Fill Color", s.colf_fill)
    ImGui.SeparatorText("Per primitive flags (AddXXX functions)")
    ImGui.TextDisabled("(stroke placement/AA flags: not ported, this port uses the 1.92 stroker)")
    ImGui.Spacing()

    local sz = s.sz
    local start_pos = ImGui.GetCursorScreenPos()
    local pi = 3.141592
    local step = sz + 10.0
    local corners_tl_br = bit32.bor(ImDrawFlags.RoundCornersTopLeft, ImDrawFlags.RoundCornersBottomRight)
    local half_sz = sz * 0.5
    local circle_segments = s.circle_override and s.circle_override_v or 0
    local curve_segments = s.curve_override and s.curve_override_v or 0
    local cp3 = { ImVec2(0.0, sz * 0.6), ImVec2(sz * 0.5, -sz * 0.4), ImVec2(sz, sz) } -- Control points for curves
    local cp4 = { ImVec2(0.0, 0.0), ImVec2(sz * 1.3, sz * 0.3), ImVec2(sz - sz * 1.3, sz - sz * 0.3), ImVec2(sz, sz) }
    local concave_shape = { { 0.0, 0.0 }, { 0.3, 0.0 }, { 0.3, 0.7 }, { 0.7, 0.7 }, { 0.7, 0.0 }, { 1.0, 0.0 }, { 1.0, 1.0 }, { 0.0, 1.0 } } -- |_| looking shape. Normalized.
    local zigzag_shape = { { 0.0, 0.0 }, { 0.9, 0.0 }, { 1.0, 0.1 }, { 1.0, 0.9 }, { 0.9, 1.0 }, { 0.3, 1.0 }, { 0.3, 0.4 }, { 0.9, 0.4 } }
    local rotating_square = {}
    for side = 0, 3 do
        local a = t * 0.1 + side * pi * 0.5
        rotating_square[side + 1] = ImVec2(math.cos(a) * half_sz, math.sin(a) * half_sz)
    end
    local function Shape(shape, x, y)
        for _, p in ipairs(shape) do draw_list:PathLineTo(ImVec2(x + math.floor(sz * p[1]), y + math.floor(sz * p[2]))) end
    end

    local y = start_pos.y
    for row = 0, 3 do
        local x = start_pos.x
        local draw_fill = (row == 2 or row == 3)
        local draw_strokes = (row == 0 or row == 1 or row == 3)
        if draw_fill then
            -- FILLED SHAPES
            local col = ImGui.ColorConvertFloat4ToU32(s.colf_fill)
            draw_list:AddNgonFilled(ImVec2(x + half_sz, y + half_sz), half_sz, col, s.ngon_segments); x = x + step -- N-gon
            draw_list:AddCircleFilled(ImVec2(x + half_sz, y + half_sz), half_sz, col, circle_segments); x = x + step -- Circle
            draw_list:AddEllipseFilled(ImVec2(x + half_sz, y + half_sz), ImVec2(half_sz, sz * 0.3), col, -0.3, circle_segments); x = x + step -- Ellipse
            draw_list:AddRectFilled(ImVec2(x, y), ImVec2(x + sz, y + sz), col); x = x + step -- Square
            draw_list:AddRectFilled(ImVec2(x, y), ImVec2(x + sz, y + sz), col, rounding); x = x + step -- Square with all rounded corners
            draw_list:AddRectFilled(ImVec2(x, y), ImVec2(x + sz, y + sz), col, rounding, corners_tl_br); x = x + step -- Square with two rounded corners
            draw_list:AddTriangleFilled(ImVec2(x + sz * 0.5, y), ImVec2(x + sz, y + sz), ImVec2(x, y + sz), col); x = x + step -- Triangle
            draw_list:AddTriangleFilled(ImVec2(x + sz * 0.2, y), ImVec2(x + sz * 0.4, y + sz), ImVec2(x, y + sz), col); x = x + step - math.floor(sz * 0.6) -- Thin triangle

            -- Concave shape: U
            Shape(concave_shape, x, y); draw_list:PathFillConcave(col); x = x + step

            -- Concave shape: Zig-Zag with sharp angles
            Shape(zigzag_shape, x, y); draw_list:PathFillConcave(col); x = x + step

            -- Horizontal/Vertical lines
            -- (here for consistency with the strokes section. AddRectFilled() is roughly close to AddLineH(), AddLineV()
            draw_list:AddRectFilled(ImVec2(x, y), ImVec2(x + sz, y + thickness), col); x = x + step
            draw_list:AddRectFilled(ImVec2(x, y), ImVec2(x + thickness, y + sz), col); x = x + step - math.floor(half_sz)
            if not (draw_fill and draw_strokes) then
                local block_sz, off = 1, 0
                while block_sz < 16 and off + block_sz <= sz do
                    draw_list:AddRectFilled(ImVec2(x, y + off), ImVec2(x + block_sz, y + off + block_sz), col)
                    off = off + block_sz + 1
                    block_sz = block_sz + 1
                end
            end
            x = x + step - math.floor(half_sz)

            -- Rotating square
            for n = 1, 4 do draw_list:PathLineTo(ImVec2(x + half_sz + rotating_square[n].x, y + half_sz + rotating_square[n].y)) end
            draw_list:PathFillConvex(col); x = x + step

            -- Path
            draw_list:PathArcTo(ImVec2(x + half_sz, y + half_sz), half_sz, pi * -0.5, pi * 1.1)
            draw_list:PathFillConvex(col); x = x + step

            -- Quadratic Bezier Curve (3 control points)
            draw_list:PathLineTo(ImVec2(x + cp3[1].x, y + cp3[1].y))
            draw_list:PathBezierQuadraticCurveTo(ImVec2(x + cp3[2].x, y + cp3[2].y), ImVec2(x + cp3[3].x, y + cp3[3].y), curve_segments)
            draw_list:PathFillConvex(col); x = x + step
            if not (draw_fill and draw_strokes) then
                draw_list:AddRectFilledMultiColor(ImVec2(x, y), ImVec2(x + sz, y + sz), IM_COL32(0, 0, 0, 255), IM_COL32(255, 0, 0, 255), IM_COL32(255, 255, 0, 255), IM_COL32(0, 255, 0, 255))
                x = x + step
            end
        end
        if draw_fill and draw_strokes then x = start_pos.x end
        if draw_strokes then
            -- STROKES
            -- First row uses a thickness of 1.0f, second row uses the configurable thickness
            local col = ImGui.ColorConvertFloat4ToU32(s.colf_stroke)
            local th = (row == 0) and 1.0 or thickness
            draw_list:AddNgon(ImVec2(x + half_sz, y + half_sz), half_sz, col, s.ngon_segments, th); x = x + step -- N-gon
            draw_list:AddCircle(ImVec2(x + half_sz, y + half_sz), half_sz, col, circle_segments, th); x = x + step -- Circle
            draw_list:AddEllipse(ImVec2(x + half_sz, y + half_sz), ImVec2(half_sz, sz * 0.3), col, -0.3, circle_segments, th); x = x + step -- Ellipse
            draw_list:AddRect(ImVec2(x, y), ImVec2(x + sz, y + sz), col, 0.0, th); x = x + step -- Square
            draw_list:AddRect(ImVec2(x, y), ImVec2(x + sz, y + sz), col, rounding, th); x = x + step -- Square with all rounded corners
            draw_list:AddRect(ImVec2(x, y), ImVec2(x + sz, y + sz), col, rounding, th, corners_tl_br); x = x + step -- Square with two rounded corners
            draw_list:AddTriangle(ImVec2(x + sz * 0.5, y), ImVec2(x + sz, y + sz), ImVec2(x, y + sz), col, th); x = x + step -- Triangle
            draw_list:AddTriangle(ImVec2(x + sz * 0.2, y), ImVec2(x + sz * 0.4, y + sz), ImVec2(x, y + sz), col, th); x = x + step - math.floor(sz * 0.6) -- Thin triangle

            -- Concave shape: U
            Shape(concave_shape, x, y); draw_list:PathStroke(col, th, ImDrawFlags.Closed); x = x + step

            -- Concave shape: Zig-Zag with sharp angles
            Shape(zigzag_shape, x, y); draw_list:PathStroke(col, th, ImDrawFlags.Closed); x = x + step

            -- Horizontal/Vertical/Diagonal lines
            local off = math.floor(sz * 0.4)
            draw_list:AddLine(ImVec2(x, y), ImVec2(x + sz, y), col, th)
            draw_list:AddLine(ImVec2(x, y + off), ImVec2(x + sz, y + off), col, th); x = x + step
            draw_list:AddLine(ImVec2(x, y), ImVec2(x, y + sz), col, th)
            draw_list:AddLine(ImVec2(x + off, y + sz), ImVec2(x + off, y), col, th); x = x + step - math.floor(half_sz)
            if not (draw_fill and draw_strokes) then
                draw_list:AddLine(ImVec2(x, y), ImVec2(x + half_sz, y + sz), col, th)
                draw_list:AddLine(ImVec2(x, y + sz), ImVec2(x + half_sz, y), col, th)
            end
            x = x + step - math.floor(half_sz)

            -- Rotating square
            for n = 1, 4 do draw_list:PathLineTo(ImVec2(x + half_sz + rotating_square[n].x, y + half_sz + rotating_square[n].y)) end
            draw_list:PathStroke(col, th, ImDrawFlags.Closed); x = x + step

            -- Path
            draw_list:PathArcTo(ImVec2(x + half_sz, y + half_sz), half_sz, pi * -0.5, pi * 1.1)
            draw_list:PathStroke(col, th); x = x + step

            -- Quadratic Bezier Curve (3 control points)
            draw_list:AddBezierQuadratic(ImVec2(x + cp3[1].x, y + cp3[1].y), ImVec2(x + cp3[2].x, y + cp3[2].y), ImVec2(x + cp3[3].x, y + cp3[3].y), col, th, curve_segments); x = x + step

            -- Cubic Bezier Curve (4 control points)
            if not (draw_fill and draw_strokes) then
                draw_list:AddBezierCubic(ImVec2(x + cp4[1].x, y + cp4[1].y), ImVec2(x + cp4[2].x, y + cp4[2].y), ImVec2(x + cp4[3].x, y + cp4[3].y), ImVec2(x + cp4[4].x, y + cp4[4].y), col, th, curve_segments)
                x = x + step
            end
        end
        y = y + step
    end
    ImGui.Dummy(ImVec2(step * 15.5, step * 4.0))
    ImGui.Text("ImDrawList Vector Rendering Reference:")
    ImGui.TextLinkOpenURL("https://github.com/ocornut/imgui/wiki/Draw-List")
    ImGui.PopItemFlag()
    ImGui.PopItemWidth()
end

local function CustomRenderingCanvas()
    local s = CRS
    _, s.opt_enable_grid = ImGui.Checkbox("Enable grid", s.opt_enable_grid)
    _, s.opt_enable_context_menu = ImGui.Checkbox("Enable context menu", s.opt_enable_context_menu)
    ImGui.Text("Mouse Left: drag to add lines,\nMouse Right: drag to scroll, click for context menu.")

    -- Typically you would use a BeginChild()/EndChild() pair to benefit from a clipping region + own scrolling.
    -- Here we demonstrate that this can be replaced by simple offsetting + custom drawing + PushClipRect/PopClipRect() calls.
    -- To use a child window instead we could use, e.g:
    --      ImGui.PushStyleVar(ImGuiStyleVar.WindowPadding, ImVec2(0, 0))      -- Disable padding
    --      ImGui.PushStyleColor(ImGuiCol.ChildBg, IM_COL32(50, 50, 50, 255))  -- Set a background color
    --      ImGui.BeginChild("canvas", ImVec2(0.0, 0.0), ImGuiChildFlags.Borders, ImGuiWindowFlags.NoMove)
    --      ImGui.PopStyleColor()
    --      ImGui.PopStyleVar()
    --      [...]
    --      ImGui.EndChild()

    -- Using InvisibleButton() as a convenience 1) it will advance the layout cursor and 2) allows us to use IsItemHovered()/IsItemActive()
    local canvas_p0 = ImGui.GetCursorScreenPos()      -- ImDrawList API uses screen coordinates!
    local canvas_sz = ImGui.GetContentRegionAvail()   -- Resize canvas to what's available
    if canvas_sz.x < 50.0 then canvas_sz.x = 50.0 end
    if canvas_sz.y < 50.0 then canvas_sz.y = 50.0 end
    local canvas_p1 = ImVec2(canvas_p0.x + canvas_sz.x, canvas_p0.y + canvas_sz.y)

    -- Draw border and background color
    local io = ImGui.GetIO()
    local draw_list = ImGui.GetWindowDrawList()
    draw_list:AddRectFilled(canvas_p0, canvas_p1, IM_COL32(50, 50, 50, 255))
    draw_list:AddRect(canvas_p0, canvas_p1, IM_COL32(255, 255, 255, 255))

    -- This will catch our interactions
    ImGui.InvisibleButton("canvas", canvas_sz, bit32.bor(ImGuiButtonFlags.MouseButtonLeft, ImGuiButtonFlags.MouseButtonRight))
    local is_hovered = ImGui.IsItemHovered() -- Hovered
    local is_active = ImGui.IsItemActive()   -- Held
    local origin = ImVec2(canvas_p0.x + s.scrolling.x, canvas_p0.y + s.scrolling.y) -- Lock scrolled origin
    local mouse_pos_in_canvas = ImVec2(io.MousePos.x - origin.x, io.MousePos.y - origin.y)
    local points = s.points

    -- Add first and second point
    if is_hovered and not s.adding_line and ImGui.IsMouseClicked(ImGuiMouseButton.Left) then
        points[#points + 1] = ImVec2(mouse_pos_in_canvas.x, mouse_pos_in_canvas.y)
        points[#points + 1] = ImVec2(mouse_pos_in_canvas.x, mouse_pos_in_canvas.y)
        s.adding_line = true
    end
    if s.adding_line then
        points[#points] = ImVec2(mouse_pos_in_canvas.x, mouse_pos_in_canvas.y)
        if not ImGui.IsMouseDown(ImGuiMouseButton.Left) then s.adding_line = false end
    end

    -- Pan (we use a zero mouse threshold when there's no context menu)
    -- You may decide to make that threshold dynamic based on whether the mouse is hovering something etc.
    local mouse_threshold_for_pan = s.opt_enable_context_menu and -1.0 or 0.0
    if is_active and ImGui.IsMouseDragging(ImGuiMouseButton.Right, mouse_threshold_for_pan) then
        s.scrolling.x = s.scrolling.x + io.MouseDelta.x
        s.scrolling.y = s.scrolling.y + io.MouseDelta.y
    end

    -- Context menu (under default mouse threshold)
    local drag_delta = ImGui.GetMouseDragDelta(ImGuiMouseButton.Right)
    if s.opt_enable_context_menu and drag_delta.x == 0.0 and drag_delta.y == 0.0 then
        ImGui.OpenPopupOnItemClick("context", ImGuiPopupFlags.MouseButtonRight)
    end
    if ImGui.BeginPopup("context") then
        if s.adding_line then points[#points] = nil; points[#points] = nil end
        s.adding_line = false
        if ImGui.MenuItem("Remove one", nil, false, #points > 0) then points[#points] = nil; points[#points] = nil end
        if ImGui.MenuItem("Remove all", nil, false, #points > 0) then table.clear(points) end
        ImGui.EndPopup()
    end

    -- Draw grid + all lines in the canvas
    draw_list:PushClipRect(canvas_p0, canvas_p1, true)
    if s.opt_enable_grid then
        local GRID_STEP = 64.0
        local x = math.fmod(s.scrolling.x, GRID_STEP)
        while x < canvas_sz.x do draw_list:AddLine(ImVec2(canvas_p0.x + x, canvas_p0.y), ImVec2(canvas_p0.x + x, canvas_p1.y), IM_COL32(200, 200, 200, 40)); x = x + GRID_STEP end
        local y = math.fmod(s.scrolling.y, GRID_STEP)
        while y < canvas_sz.y do draw_list:AddLine(ImVec2(canvas_p0.x, canvas_p0.y + y), ImVec2(canvas_p1.x, canvas_p0.y + y), IM_COL32(200, 200, 200, 40)); y = y + GRID_STEP end
    end
    for n = 1, #points - 1, 2 do
        draw_list:AddLine(ImVec2(origin.x + points[n].x, origin.y + points[n].y), ImVec2(origin.x + points[n + 1].x, origin.y + points[n + 1].y), IM_COL32(255, 255, 0, 255), 2.0)
    end
    draw_list:PopClipRect()
end

-- Demonstrate using the low-level ImDrawList to draw custom shapes.
function ShowExampleAppCustomRendering(p_open)
    local visible
    p_open, visible = ImGui.Begin("Example: Custom rendering", p_open)
    if not visible then ImGui.End(); return p_open end
    local s = CRS
    if ImGui.BeginTabBar("##TabBar") then
        if ImGui.BeginTabItem("Primitives") then CustomRenderingPrimitives(); ImGui.EndTabItem() end
        if ImGui.BeginTabItem("Canvas") then CustomRenderingCanvas(); ImGui.EndTabItem() end
        if ImGui.BeginTabItem("BG/FG draw lists") then
            _, s.draw_bg = ImGui.Checkbox("Draw in Background draw list", s.draw_bg)
            ImGui.SameLine(); HelpMarker("The Background draw list will be rendered below every Dear ImGui windows.")
            _, s.draw_fg = ImGui.Checkbox("Draw in Foreground draw list", s.draw_fg)
            ImGui.SameLine(); HelpMarker("The Foreground draw list will be rendered over every Dear ImGui windows.")
            local window_pos, window_size = ImGui.GetWindowPos(), ImGui.GetWindowSize()
            local window_center = ImVec2(window_pos.x + window_size.x * 0.5, window_pos.y + window_size.y * 0.5)
            if s.draw_bg then ImGui.GetBackgroundDrawList():AddCircle(window_center, window_size.x * 0.6, IM_COL32(255, 0, 0, 200), 0, 10 + 4) end
            if s.draw_fg then ImGui.GetForegroundDrawList():AddCircle(window_center, window_size.y * 0.6, IM_COL32(0, 255, 0, 200), 0, 10) end
            ImGui.EndTabItem()
        end

        -- Demonstrate out-of-order rendering via channels splitting
        -- We use functions in ImDrawList as each draw list contains a convenience splitter,
        -- but you can also instantiate your own ImDrawListSplitter if you need to nest them.
        if ImGui.BeginTabItem("Draw Channels") then
            local draw_list = ImGui.GetWindowDrawList()
            ImGui.Text("Blue shape is drawn first: appears in back")
            ImGui.Text("Red shape is drawn after: appears in front")
            local p0 = ImGui.GetCursorScreenPos()
            draw_list:AddRectFilled(ImVec2(p0.x, p0.y), ImVec2(p0.x + 50, p0.y + 50), IM_COL32(0, 0, 255, 255)) -- Blue
            draw_list:AddRectFilled(ImVec2(p0.x + 25, p0.y + 25), ImVec2(p0.x + 75, p0.y + 75), IM_COL32(255, 0, 0, 255)) -- Red
            ImGui.Dummy(ImVec2(75, 75))
            ImGui.Separator()
            ImGui.Text("Blue shape is drawn first, into channel 1: appears in front")
            ImGui.Text("Red shape is drawn after, into channel 0: appears in back")
            local p1 = ImGui.GetCursorScreenPos()

            -- Create 2 channels and draw a Blue shape THEN a Red shape.
            -- You can create any number of channels. Tables API use 1 channel per column in order to better batch draw calls.
            draw_list:ChannelsSplit(2)
            draw_list:ChannelsSetCurrent(1)
            draw_list:AddRectFilled(ImVec2(p1.x, p1.y), ImVec2(p1.x + 50, p1.y + 50), IM_COL32(0, 0, 255, 255)) -- Blue
            draw_list:ChannelsSetCurrent(0)
            draw_list:AddRectFilled(ImVec2(p1.x + 25, p1.y + 25), ImVec2(p1.x + 75, p1.y + 75), IM_COL32(255, 0, 0, 255)) -- Red

            -- Flatten/reorder channels. Red shape is in channel 0 and it appears below the Blue shape in channel 1.
            -- This works by copying draw indices only (vertices are not copied).
            draw_list:ChannelsMerge()
            ImGui.Dummy(ImVec2(75, 75))
            ImGui.Text("After reordering, contents of channel 0 appears below channel 1.")
            ImGui.EndTabItem()
        end
        ImGui.EndTabBar()
    end
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Docking, DockSpace / ShowExampleAppDockSpace()
-------------------------------------------------------------------------------

-- KeepWindowPadding: Keep WindowPadding to help understand that DockSpace() is a widget inside the window.
local DSA = { IsFullscreen = true, KeepWindowPadding = false, DockSpaceFlags = 0, opt_demo_mode = 0, opt_demo_mode_changed = false }

-- THIS IS A DEMO FOR ADVANCED USAGE OF DockSpace().
-- MOST REGULAR APPLICATIONS WANTING TO ALLOW DOCKING WINDOWS ON THE EDGE OF YOUR SCREEN CAN SIMPLY USE:
--    ImGui.NewFrame() + ImGui.DockSpaceOverViewport()                                                   -- Create a dockspace in main viewport
-- OR:
--    ImGui.NewFrame() + ImGui.DockSpaceOverViewport(0, nil, ImGuiDockNodeFlags.PassthruCentralNode)     -- Create a dockspace in main viewport, where central node is transparent.
-- Demonstrate using DockSpace() to create an explicit docking node within an existing window, with various options.
-- Read https://github.com/ocornut/imgui/wiki/Docking for details.
-- The reasons we do not use DockSpaceOverViewport() in this demo is because:
-- - (1) we allow the host window to be floating/moveable instead of filling the viewport (when args.IsFullscreen == false)
--       which is mostly to showcase the idea that DockSpace() may be submitted anywhere.
--       Also see 'Demo->Examples->Documents' for a less abstract version of this.
-- - (2) we allow the host window to have padding (when args.UsePadding == true)
-- - (3) we expose variety of other flags.
local function ShowExampleAppDockSpaceAdvanced(args, p_open)
    local dockspace_flags = args.DockSpaceFlags

    -- We are using the ImGuiWindowFlags_NoDocking flag to make the parent window not dockable into,
    -- because it would be confusing to have two docking targets within each others.
    local W = ImGuiWindowFlags
    local window_flags = W.NoDocking
    if args.IsFullscreen then
        -- Fullscreen dockspace: practically the same as calling DockSpaceOverViewport()
        local viewport = ImGui.GetMainViewport()
        ImGui.SetNextWindowPos(viewport.WorkPos)
        ImGui.SetNextWindowSize(viewport.WorkSize)
        ImGui.SetNextWindowViewport(viewport.ID)
        ImGui.PushStyleVar(ImGuiStyleVar.WindowRounding, 0.0)
        ImGui.PushStyleVar(ImGuiStyleVar.WindowBorderSize, 0.0)
        window_flags = bit32.bor(window_flags, W.NoTitleBar, W.NoCollapse, W.NoResize, W.NoMove, W.NoBringToFrontOnFocus, W.NoNavFocus, W.NoBackground)
    else
        -- Floating dockspace
        dockspace_flags = bit32.band(dockspace_flags, bit32.bnot(ImGuiDockNodeFlags.PassthruCentralNode))
    end

    -- Important: note that we proceed even if Begin() returns false (aka window is collapsed).
    -- This is because we want to keep our DockSpace() active. If a DockSpace() is inactive,
    -- all active windows docked into it will lose their parent and become undocked.
    -- We cannot preserve the docking relationship between an active window and an inactive docking, otherwise
    -- any change of dockspace/settings would lead to windows being stuck in limbo and never being visible.
    if not args.KeepWindowPadding then ImGui.PushStyleVar(ImGuiStyleVar.WindowPadding, ImVec2(0.0, 0.0)) end
    p_open = ImGui.Begin("Window with a DockSpace", p_open, window_flags)
    if not args.KeepWindowPadding then ImGui.PopStyleVar() end

    if args.IsFullscreen then ImGui.PopStyleVar(2) end

    -- Submit the DockSpace widget inside our window
    -- - Note that the id here is different from the one used by DockSpaceOverViewport(), so docking state won't get transfered between "Basic" and "Advanced" demos.
    -- - If we made the ShowExampleAppDockSpaceBasic() calculate its own ID and pass it to DockSpaceOverViewport() the ID could easily match.
    local dockspace_id = ImGui.GetID("MyDockSpace")
    ImGui.DockSpace(dockspace_id, ImVec2(0.0, 0.0), dockspace_flags)
    ImGui.End()
    return p_open
end

function ShowExampleAppDockSpace(p_open)
    local args = DSA
    if args.opt_demo_mode == 0 then
        -- Basic version which you can use in many apps:
        -- e.g:
        --   ImGui.DockSpaceOverViewport()
        -- or:
        --   ImGui.DockSpaceOverViewport(0, nil, ImGuiDockNodeFlags.PassthruCentralNode) -- Central node will be transparent
        -- or:
        --   local viewport = ImGui.GetMainViewport()
        --   ImGui.DockSpaceOverViewport(0, viewport, ImGuiDockNodeFlags.None)
        ImGui.DockSpaceOverViewport(0, nil, args.DockSpaceFlags)
    else
        p_open = ShowExampleAppDockSpaceAdvanced(args, p_open)
    end

    -- Refocus our window to minimize perceived loss of focus when changing mode (caused by the fact that each use a different window, which would not happen in a real app)
    if args.opt_demo_mode_changed then ImGui.SetNextWindowFocus() end
    p_open = ImGui.Begin("Examples: Dockspace", p_open, ImGuiWindowFlags.MenuBar)
    local c1, c2
    c1, args.opt_demo_mode = ImGui.RadioButton("Basic demo mode", args.opt_demo_mode, 0)
    c2, args.opt_demo_mode = ImGui.RadioButton("Advanced demo mode", args.opt_demo_mode, 1)
    args.opt_demo_mode_changed = c1 or c2
    ImGui.SeparatorText("Options")
    local D = ImGuiDockNodeFlags
    if bit32.band(ImGui.GetIO().ConfigFlags, ImGuiConfigFlags.DockingEnable) == 0 then
        ShowDockingDisabledMessage()
    elseif args.opt_demo_mode == 0 then
        args.DockSpaceFlags = bit32.band(args.DockSpaceFlags, D.PassthruCentralNode) -- Allowed flags
        _, args.DockSpaceFlags = ImGui.CheckboxFlags("Flag: PassthruCentralNode", args.DockSpaceFlags, D.PassthruCentralNode)
    else
        _, args.IsFullscreen = ImGui.Checkbox("Fullscreen", args.IsFullscreen)
        _, args.KeepWindowPadding = ImGui.Checkbox("Keep Window Padding", args.KeepWindowPadding)
        ImGui.SameLine()
        HelpMarker("This is mostly exposed to facilitate understanding that a DockSpace() is _inside_ a window.")
        ImGui.BeginDisabled(args.IsFullscreen == false)
        _, args.DockSpaceFlags = ImGui.CheckboxFlags("Flag: PassthruCentralNode", args.DockSpaceFlags, D.PassthruCentralNode)
        ImGui.EndDisabled()
        for _, n in ipairs({ "NoDockingOverCentralNode", "NoDockingSplit", "NoUndocking", "NoResize", "AutoHideTabBar" }) do
            if D[n] then _, args.DockSpaceFlags = ImGui.CheckboxFlags("Flag: " .. n, args.DockSpaceFlags, D[n]) end
        end
    end

    -- Show demo options and help
    if ImGui.BeginMenuBar() then
        if ImGui.BeginMenu("Help") then
            ImGui.TextUnformatted("This demonstrates the use of ImGui::DockSpace() which allows you to manually\ncreate a docking node _within_ another window.\nThe \"Basic\" version uses the ImGui::DockSpaceOverViewport() helper. Most applications can probably use this.")
            ImGui.Separator()
            ImGui.TextUnformatted("When docking is enabled, you can ALWAYS dock MOST window into another! Try it now!\n- Drag from window title bar or their tab to dock/undock.\n- Drag from window menu button (upper-left button) to undock an entire node (all windows).\n- Hold SHIFT to disable docking (if io.ConfigDockingWithShift == false, default)\n- Hold SHIFT to enable docking (if io.ConfigDockingWithShift == true)")
            ImGui.Separator()
            ImGui.TextUnformatted("More details:"); ImGui.Bullet(); ImGui.SameLine(); ImGui.TextLinkOpenURL("Docking Wiki page", "https://github.com/ocornut/imgui/wiki/Docking")
            ImGui.BulletText("Read comments in ShowExampleAppDockSpace()")
            ImGui.EndMenu()
        end
        ImGui.EndMenuBar()
    end
    ImGui.End()
    return p_open
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Documents Handling / ShowExampleAppDocuments()
-------------------------------------------------------------------------------

-- Simplified structure to mimic a Document model
-- NameBuf: Document title
-- UID: Unique ID (necessary as we can change title)
-- Open: Set when open (we keep an array of all available documents to simplify demo code!)
-- OpenPrev: Copy of Open from last update.
-- Dirty: Set when the document has been modified
-- Color: An arbitrary variable associated to the document
local function MyDocument(uid, name, open, color)
    if open == nil then open = true end
    local d = { UID = uid, NameBuf = Buf(name, 32), Open = open, OpenPrev = open, Dirty = false, Color = color or ImVec4(1.0, 1.0, 1.0, 1.0) }
    function d:Name() return BufStr(self.NameBuf) end
    function d:DoOpen() self.Open = true end
    function d:DoForceClose() self.Open = false; self.Dirty = false end
    function d:DoSave() self.Dirty = false end
    return d
end

local Docs = nil
local function DocsInit()
    local app = { Documents = {
        MyDocument(0, "Lettuce", true, ImVec4(0.4, 0.8, 0.4, 1.0)),
        MyDocument(1, "Eggplant", true, ImVec4(0.8, 0.5, 1.0, 1.0)),
        MyDocument(2, "Carrot", true, ImVec4(1.0, 0.8, 0.5, 1.0)),
        MyDocument(3, "Tomato", false, ImVec4(1.0, 0.3, 0.4, 1.0)),
        MyDocument(4, "A Rather Long Title", false, ImVec4(0.4, 0.8, 0.8, 1.0)),
        MyDocument(5, "Some Document", false, ImVec4(0.8, 0.8, 1.0, 1.0)),
    }, CloseQueue = {}, RenamingDoc = nil, RenamingStarted = false,
    opt_target = 1, opt_reorderable = true, opt_fitting_flags = ImGuiTabBarFlags.FittingPolicyDefault_ }
    function app:QueueClose(doc)
        for _, d in ipairs(self.CloseQueue) do if d == doc then return end end
        self.CloseQueue[#self.CloseQueue + 1] = doc
    end
    -- As we allow to change document name, we append a never-changing document ID so tabs are stable
    function app:GetTabName(doc) return string.format("%s###doc%d", doc:Name(), doc.UID) end
    -- Display placeholder contents for the Document
    function app:DisplayDocContents(doc)
        ImGui.PushID("doc" .. doc.UID)
        ImGui.Text("Document \"%s\"", doc:Name())
        ImGui.PushStyleColor(ImGuiCol.Text, doc.Color)
        ImGui.TextWrapped("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.")
        ImGui.PopStyleColor()

        ImGui.SetNextItemShortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.R), ImGuiInputFlags.Tooltip)
        if ImGui.Button("Rename..") then self.RenamingDoc = doc; self.RenamingStarted = true end
        ImGui.SameLine()
        ImGui.SetNextItemShortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.M), ImGuiInputFlags.Tooltip)
        if ImGui.Button("Modify") then doc.Dirty = true end
        ImGui.SameLine()
        ImGui.SetNextItemShortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.S), ImGuiInputFlags.Tooltip)
        if ImGui.Button("Save") then doc:DoSave() end
        ImGui.SameLine()
        ImGui.SetNextItemShortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.W), ImGuiInputFlags.Tooltip)
        if ImGui.Button("Close") then self:QueueClose(doc) end
        ImGui.ColorEdit3("color", doc.Color) -- Useful to test drag and drop and hold-dragged-to-open-tab behavior.
        ImGui.PopID()
    end
    -- Display context menu for the Document
    function app:DisplayDocContextMenu(doc)
        if not ImGui.BeginPopupContextItem() then return end
        if ImGui.MenuItem("Save " .. doc:Name(), "Ctrl+S", false, doc.Open) then doc:DoSave() end
        if ImGui.MenuItem("Rename...", "Ctrl+R", false, doc.Open) then self.RenamingDoc = doc end
        if ImGui.MenuItem("Close", "Ctrl+W", false, doc.Open) then self:QueueClose(doc) end
        ImGui.EndPopup()
    end
    -- [Optional] Notify the system of Tabs/Windows closure that happened outside the regular tab interface.
    -- If a tab has been closed programmatically (aka closed from another source such as the Checkbox() in the demo,
    -- as opposed to clicking on the regular tab closing button) and stops being submitted, it will take a frame for
    -- the tab bar to notice its absence. During this frame there will be a gap in the tab bar, and if the tab that has
    -- disappeared was the selected one, the tab bar will report no selected tab during the frame. This will effectively
    -- give the impression of a flicker for one frame.
    -- We call SetTabItemClosed() to manually notify the Tab Bar or Docking system of removed tabs to avoid this glitch.
    -- Note that this completely optional, and only affect tab bars with the ImGuiTabBarFlags.Reorderable flag.
    function app:NotifyOfDocumentsClosedElsewhere()
        for _, doc in ipairs(self.Documents) do
            if not doc.Open and doc.OpenPrev then ImGui.SetTabItemClosed(doc:Name()) end
            doc.OpenPrev = doc.Open
        end
    end
    return app
end

function ShowExampleAppDocuments(p_open)
    Docs = Docs or DocsInit()
    local app = Docs
    -- Options
    -- Target_Tab: Create documents as local tab into a local tab bar
    -- Target_DockSpaceAndWindow: Create documents as regular windows, and create an embedded dockspace
    local Target_Tab, Target_DockSpaceAndWindow = 1, 2

    -- When (opt_target == Target_DockSpaceAndWindow) there is the possibily that one of our child Document window (e.g. "Eggplant")
    -- that we emit gets docked into the same spot as the parent window ("Example: Documents").
    -- This would create a problematic feedback loop because selecting the "Eggplant" tab would make the "Example: Documents" tab
    -- not visible, which in turn would stop submitting the "Eggplant" window.
    -- We avoid this problem by submitting our documents window even if our parent window is not currently visible.
    -- Another solution may be to make the "Example: Documents" window use the ImGuiWindowFlags.NoDocking.

    local window_contents_visible
    p_open, window_contents_visible = ImGui.Begin("Example: Documents", p_open, ImGuiWindowFlags.MenuBar)
    if not window_contents_visible and app.opt_target ~= Target_DockSpaceAndWindow then
        ImGui.End()
        return p_open
    end

    -- Menu
    if ImGui.BeginMenuBar() then
        if ImGui.BeginMenu("File") then
            local open_count = 0
            for _, doc in ipairs(app.Documents) do if doc.Open then open_count = open_count + 1 end end
            if ImGui.BeginMenu("Open", open_count < #app.Documents) then
                for _, doc in ipairs(app.Documents) do
                    if not doc.Open and ImGui.MenuItem(doc:Name()) then doc:DoOpen() end
                end
                ImGui.EndMenu()
            end
            if ImGui.MenuItem("Close All Documents", nil, false, open_count > 0) then
                for _, doc in ipairs(app.Documents) do app:QueueClose(doc) end
            end
            if ImGui.MenuItem("Exit") and p_open ~= nil then p_open = false end
            ImGui.EndMenu()
        end
        ImGui.EndMenuBar()
    end

    -- [Debug] List documents with one checkbox for each
    for doc_n, doc in ipairs(app.Documents) do
        if doc_n > 1 then ImGui.SameLine() end
        ImGui.PushID("doc" .. doc.UID)
        local pressed
        pressed, doc.Open = ImGui.Checkbox(doc:Name(), doc.Open)
        if pressed and not doc.Open then doc:DoForceClose() end
        ImGui.PopID()
    end
    ImGui.PushItemWidth(ImGui.GetFontSize() * 12)
    app.opt_target = ImGui.Combo("Output", app.opt_target, "None\0TabBar+Tabs\0DockSpace+Window\0")
    ImGui.PopItemWidth()
    local redock_all = false
    if app.opt_target == Target_Tab then ImGui.SameLine(); _, app.opt_reorderable = ImGui.Checkbox("Reorderable Tabs", app.opt_reorderable) end
    if app.opt_target == Target_DockSpaceAndWindow then ImGui.SameLine(); redock_all = ImGui.Button("Redock all") end
    ImGui.Separator()

    -- About the ImGuiWindowFlags.UnsavedDocument / ImGuiTabItemFlags.UnsavedDocument flags.
    -- They have multiple effects:
    -- - Display a dot next to the title.
    -- - Tab is selected when clicking the X close button.
    -- - Closure is not assumed (will wait for user to stop submitting the tab).
    --   Otherwise closure is assumed when pressing the X, so if you keep submitting the tab may reappear at end of tab bar.
    --   We need to assume closure by default otherwise waiting for "lack of submission" on the next frame would leave an empty
    --   hole for one-frame, both in the tab-bar and in tab-contents when closing a tab/window.
    --   The rarely used SetTabItemClosed() function is a way to notify of programmatic closure to avoid the one-frame hole.

    -- Tabs
    if app.opt_target == Target_Tab then
        local tab_bar_flags = bit32.bor(app.opt_fitting_flags, app.opt_reorderable and ImGuiTabBarFlags.Reorderable or 0, ImGuiTabBarFlags.DrawSelectedOverline)
        if ImGui.BeginTabBar("##tabs", tab_bar_flags) then
            if app.opt_reorderable then app:NotifyOfDocumentsClosedElsewhere() end

            -- Submit Tabs
            for _, doc in ipairs(app.Documents) do
                if doc.Open then
                    -- As we allow to change document name, we append a never-changing document id so tabs are stable
                    local tab_flags = doc.Dirty and ImGuiTabItemFlags.UnsavedDocument or 0
                    local visible
                    visible, doc.Open = ImGui.BeginTabItem(app:GetTabName(doc), doc.Open, tab_flags)

                    -- Cancel attempt to close when unsaved add to save queue so we can display a popup.
                    if not doc.Open and doc.Dirty then
                        doc.Open = true
                        app:QueueClose(doc)
                    end
                    app:DisplayDocContextMenu(doc)
                    if visible then
                        app:DisplayDocContents(doc)
                        ImGui.EndTabItem()
                    end
                end
            end
            ImGui.EndTabBar()
        end
    elseif app.opt_target == Target_DockSpaceAndWindow then
        if bit32.band(ImGui.GetIO().ConfigFlags, ImGuiConfigFlags.DockingEnable) ~= 0 then
            app:NotifyOfDocumentsClosedElsewhere()

            -- Create a DockSpace node where any window can be docked
            local dockspace_id = ImGui.GetID("MyDockSpace")
            ImGui.DockSpace(dockspace_id)

            -- Create Windows
            for _, doc in ipairs(app.Documents) do
                if doc.Open then
                    ImGui.SetNextWindowDockID(dockspace_id, redock_all and ImGuiCond.Always or ImGuiCond.FirstUseEver)
                    local window_flags = doc.Dirty and ImGuiWindowFlags.UnsavedDocument or 0
                    local visible
                    doc.Open, visible = ImGui.Begin(doc:Name(), doc.Open, window_flags)

                    -- Cancel attempt to close when unsaved add to save queue so we can display a popup.
                    if not doc.Open and doc.Dirty then
                        doc.Open = true
                        app:QueueClose(doc)
                    end
                    app:DisplayDocContextMenu(doc)
                    if visible then app:DisplayDocContents(doc) end
                    ImGui.End()
                end
            end
        else
            ShowDockingDisabledMessage()
        end
    end

    -- Early out other contents
    if not window_contents_visible then
        ImGui.End()
        return p_open
    end

    -- Display renaming UI
    if app.RenamingDoc ~= nil then
        if app.RenamingStarted then ImGui.OpenPopup("Rename") end
        if ImGui.BeginPopup("Rename") then
            ImGui.SetNextItemWidth(ImGui.GetFontSize() * 30)
            if ImGui.InputText("###Name", app.RenamingDoc.NameBuf, 32, ImGuiInputTextFlags.EnterReturnsTrue) then
                ImGui.CloseCurrentPopup()
                app.RenamingDoc = nil
            end
            if app.RenamingStarted then ImGui.SetKeyboardFocusHere(-1) end
            ImGui.EndPopup()
        else
            app.RenamingDoc = nil
        end
        app.RenamingStarted = false
    end

    -- Display closing confirmation UI
    if #app.CloseQueue > 0 then
        local close_queue_unsaved_documents = 0
        for _, doc in ipairs(app.CloseQueue) do if doc.Dirty then close_queue_unsaved_documents = close_queue_unsaved_documents + 1 end end
        if close_queue_unsaved_documents == 0 then
            -- Close documents when all are unsaved
            for _, doc in ipairs(app.CloseQueue) do doc:DoForceClose() end
            app.CloseQueue = {}
        else
            if not ImGui.IsPopupOpen("Save?") then ImGui.OpenPopup("Save?") end
            if ImGui.BeginPopupModal("Save?", nil, ImGuiWindowFlags.AlwaysAutoResize) then
                ImGui.Text("Save change to the following items?")
                local item_height = ImGui.GetTextLineHeightWithSpacing()
                if ImGui.BeginChild(ImGui.GetID("frame"), ImVec2(-FLT_MIN, 6.25 * item_height), ImGuiChildFlags.FrameStyle) then
                    for _, doc in ipairs(app.CloseQueue) do if doc.Dirty then ImGui.Text("%s", doc:Name()) end end
                end
                ImGui.EndChild()
                local button_size = ImVec2(ImGui.GetFontSize() * 7.0, 0.0)
                if ImGui.Button("Yes", button_size) then
                    for _, doc in ipairs(app.CloseQueue) do
                        if doc.Dirty then doc:DoSave() end
                        doc:DoForceClose()
                    end
                    app.CloseQueue = {}
                    ImGui.CloseCurrentPopup()
                end
                ImGui.SameLine()
                if ImGui.Button("No", button_size) then
                    for _, doc in ipairs(app.CloseQueue) do doc:DoForceClose() end
                    app.CloseQueue = {}
                    ImGui.CloseCurrentPopup()
                end
                ImGui.SameLine()
                if ImGui.Button("Cancel", button_size) then
                    app.CloseQueue = {}
                    ImGui.CloseCurrentPopup()
                end
                ImGui.EndPopup()
            end
        end
    end
    ImGui.End()
    return p_open
end
end --[[ imgui_demo_apps.lua ]]

do --[[ imgui_demo_widgets.lua ]]
-- Demo: DemoWindowWidgets*() sections (port of imgui_demo.cpp). Globals picked up by DemoWindowWidgets() in imgui_demo.lua.
local _
local function HSV(h, s, v, a) local r, g, b = ImGui.ColorConvertHSVtoRGB(h, s, v) return ImVec4(r, g, b, a or 1.0) end
local Buf, BufStr = DemoBuf, DemoBufStr
local S = {} -- statics, one subtable per section

local ExampleNames = {
    "Artichoke", "Arugula", "Asparagus", "Avocado", "Bamboo Shoots", "Bean Sprouts", "Beans", "Beet", "Belgian Endive", "Bell Pepper",
    "Bitter Gourd", "Bok Choy", "Broccoli", "Brussels Sprouts", "Burdock Root", "Cabbage", "Calabash", "Capers", "Carrot", "Cassava",
    "Cauliflower", "Celery", "Celery Root", "Celcuce", "Chayote", "Chinese Broccoli", "Corn", "Cucumber" }

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsBasic()
-------------------------------------------------------------------------------

S.basic = { clicked = 0, check = true, e = 0, counter = 0, str0 = Buf("Hello, world!", 128), str1 = Buf("", 128),
    i0 = 123, f0 = 0.001, d0 = 999999.00000001, f1 = 1.e10, vec4a = { 0.10, 0.20, 0.30, 0.44 },
    di1 = 50, di2 = 42, di3 = 128, df1 = 1.0, df2 = 0.0067, si1 = 0, sf1 = 0.123, sf2 = 0.0, angle = 0.0, elem = 0,
    col1 = { 1.0, 0.0, 0.2 }, col2 = { 0.4, 0.7, 0.0, 0.5 }, combo = 0, listbox = 1 }

function DemoWindowWidgetsBasic()
    if not ImGui.TreeNode("Basic") then return end
    local s = S.basic
    ImGui.SeparatorText("General")
    if ImGui.Button("Button") then s.clicked = s.clicked + 1 end
    if s.clicked % 2 == 1 then ImGui.SameLine(); ImGui.Text("Thanks for clicking me!") end
    _, s.check = ImGui.Checkbox("checkbox", s.check)
    _, s.e = ImGui.RadioButton("radio a", s.e, 0); ImGui.SameLine()
    _, s.e = ImGui.RadioButton("radio b", s.e, 1); ImGui.SameLine()
    _, s.e = ImGui.RadioButton("radio c", s.e, 2)
    ImGui.AlignTextToFramePadding()
    ImGui.TextLinkOpenURL("Hyperlink", "https://github.com/ocornut/imgui/wiki/Error-Handling")

    -- Color buttons, demonstrate using PushID() to add unique identifier in the ID stack, and changing style.
    for i = 0, 6 do
        if i > 0 then ImGui.SameLine() end
        ImGui.PushID(i)
        ImGui.PushStyleColor(ImGuiCol.Button, HSV(i / 7.0, 0.6, 0.6))
        ImGui.PushStyleColor(ImGuiCol.ButtonHovered, HSV(i / 7.0, 0.7, 0.7))
        ImGui.PushStyleColor(ImGuiCol.ButtonActive, HSV(i / 7.0, 0.8, 0.8))
        ImGui.Button("Click")
        ImGui.PopStyleColor(3)
        ImGui.PopID()
    end

    -- Use AlignTextToFramePadding() to align text baseline to the baseline of framed widgets elements
    -- (otherwise a Text+SameLine+Button sequence will have the text a little too high by default!)
    -- See 'Demo->Layout->Text Baseline Alignment' for details.
    ImGui.AlignTextToFramePadding()
    ImGui.Text("Hold to repeat:")
    ImGui.SameLine()

    -- Arrow buttons with Repeater
    local spacing = ImGui.GetStyle().ItemInnerSpacing.x
    ImGui.PushItemFlag(ImGuiItemFlags.ButtonRepeat, true)
    if ImGui.ArrowButton("##left", ImGuiDir.Left) then s.counter = s.counter - 1 end
    ImGui.SameLine(0.0, spacing)
    if ImGui.ArrowButton("##right", ImGuiDir.Right) then s.counter = s.counter + 1 end
    ImGui.PopItemFlag()
    ImGui.SameLine()
    ImGui.Text("%d", s.counter)
    ImGui.Button("Tooltip")
    ImGui.SetItemTooltip("I am a tooltip")
    ImGui.LabelText("label", "Value")

    ImGui.SeparatorText("Inputs")
    ImGui.InputText("input text", s.str0, 128)
    ImGui.SameLine(); HelpMarker("USER:\nHold Shift or use mouse to select text.\nCtrl+Left/Right to word jump.\nCtrl+A or Double-Click to select all.\nCtrl+X,Ctrl+C,Ctrl+V for clipboard.\nCtrl+Z to undo, Ctrl+Y/Ctrl+Shift+Z to redo.\nEscape to revert.")
    ImGui.InputTextWithHint("input text (w/ hint)", "enter text here", s.str1, 128)
    s.i0 = ImGui.InputInt("input int", s.i0)
    s.f0 = ImGui.InputFloat("input float", s.f0, 0.01, 1.0, "%.3f")
    s.d0 = ImGui.InputDouble("input double", s.d0, 0.01, 1.0, "%.8f")
    s.f1 = ImGui.InputFloat("input scientific", s.f1, 0.0, 0.0, "%e")
    ImGui.SameLine(); HelpMarker("You can input value using the scientific notation,\n  e.g. \"1e+8\" becomes \"100000000\".")
    ImGui.InputFloat3("input float3", s.vec4a)

    ImGui.SeparatorText("Drags")
    s.di1 = ImGui.DragInt("drag int", s.di1, 1)
    ImGui.SameLine(); HelpMarker("Click and drag to edit value.\nHold Shift/Alt for faster/slower edit.\nDouble-Click or Ctrl+Click to input value.")
    s.di2 = ImGui.DragInt("drag int 0..100", s.di2, 1, 0, 100, "%d%%", ImGuiSliderFlags.AlwaysClamp)
    s.di3 = ImGui.DragInt("drag int wrap 100..200", s.di3, 1, 100, 200, "%d", ImGuiSliderFlags.WrapAround)
    s.df1 = ImGui.DragFloat("drag float", s.df1, 0.005)
    s.df2 = ImGui.DragFloat("drag small float", s.df2, 0.0001, 0.0, 0.0, "%.06f ns")
    -- ImGui.DragFloat("drag wrap -1..1", f3, 0.005, -1.0, 1.0, nil, ImGuiSliderFlags.WrapAround)

    ImGui.SeparatorText("Sliders")
    s.si1 = ImGui.SliderInt("slider int", s.si1, -1, 3)
    ImGui.SameLine(); HelpMarker("Ctrl+Click to input value.")
    s.sf1 = ImGui.SliderFloat("slider float", s.sf1, 0.0, 1.0, "ratio = %.3f")
    s.sf2 = ImGui.SliderFloat("slider float (log)", s.sf2, -10.0, 10.0, "%.4f", ImGuiSliderFlags.Logarithmic)
    s.angle = ImGui.SliderAngle("slider angle", s.angle)

    -- Using the format string to display a name instead of an integer.
    -- Here we completely omit '%d' from the format string, so it'll only display a name.
    -- This technique can also be used with DragInt().
    local elems_names = { "Fire", "Earth", "Air", "Water" }
    local elem_name = elems_names[s.elem + 1] or "Unknown"
    s.elem = ImGui.SliderInt("slider enum", s.elem, 0, 3, elem_name) -- Use ImGuiSliderFlags.NoInput flag to disable Ctrl+Click here.
    ImGui.SameLine(); HelpMarker("Using the format string parameter to display a name instead of the underlying integer.")

    ImGui.SeparatorText("Selectors/Pickers")
    ImGui.ColorEdit3("color 1", s.col1)
    ImGui.SameLine(); HelpMarker("Click on the color square to open a color picker.\nClick and hold to use drag and drop.\nRight-Click on the color square to show options.\nCtrl+Click on individual component to input value.\n")
    ImGui.ColorEdit4("color 2", s.col2)

    -- Using the _simplified_ one-liner Combo() api here
    -- See "Combo" section for examples of how to use the more flexible BeginCombo()/EndCombo() api.
    s.combo = ImGui.Combo("combo", s.combo, { "AAAA", "BBBB", "CCCC", "DDDD", "EEEE", "FFFF", "GGGG", "HHHH", "IIIIIII", "JJJJ", "KKKKKKK" })
    ImGui.SameLine(); HelpMarker("Using the simplified one-liner Combo API here.")

    -- Using the _simplified_ one-liner ListBox() api here
    -- See "List boxes" section for examples of how to use the more flexible BeginListBox()/EndListBox() api.
    s.listbox = ImGui.ListBox("listbox", s.listbox, { "Apple", "Banana", "Cherry", "Kiwi", "Mango", "Orange", "Pineapple", "Strawberry", "Watermelon" }, 9, 4)
    ImGui.SameLine(); HelpMarker("Using the simplified one-liner ListBox API here.")
    ImGui.TreePop()
end

S.chdr = { closable_group = true }

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsBullets()
-------------------------------------------------------------------------------

function DemoWindowWidgetsBullets()
    if not ImGui.TreeNode("Bullets") then return end
    ImGui.BulletText("Bullet point 1")
    ImGui.BulletText("Bullet point 2\nOn multiple lines")
    if ImGui.TreeNode("Tree node") then ImGui.BulletText("Another bullet point"); ImGui.TreePop() end
    ImGui.Bullet(); ImGui.Text("Bullet point 3 (two calls)")
    ImGui.Bullet(); ImGui.SmallButton("Button")
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsCollapsingHeaders()
-------------------------------------------------------------------------------

function DemoWindowWidgetsCollapsingHeaders()
    if not ImGui.TreeNode("Collapsing Headers") then return end
    local s = S.chdr
    _, s.closable_group = ImGui.Checkbox("Show 2nd header", s.closable_group)
    if ImGui.CollapsingHeader("Header", ImGuiTreeNodeFlags.None) then
        ImGui.Text("IsItemHovered: %d", ImGui.IsItemHovered() and 1 or 0)
        for i = 0, 4 do ImGui.Text("Some content %d", i) end
    end
    local open
    open, s.closable_group = ImGui.CollapsingHeader("Header with a close button", s.closable_group)
    if open then
        ImGui.Text("IsItemHovered: %d", ImGui.IsItemHovered() and 1 or 0)
        for i = 0, 4 do ImGui.Text("More content %d", i) end
    end
    -- if ImGui.CollapsingHeader("Header with a bullet", ImGuiTreeNodeFlags.Bullet) then
    --     ImGui.Text("IsItemHovered: %d", ImGui.IsItemHovered())
    -- end
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsColorAndPickers()
-------------------------------------------------------------------------------

IMGUI_PAYLOAD_TYPE_COLOR_3F = IMGUI_PAYLOAD_TYPE_COLOR_3F or "_COL3F"
IMGUI_PAYLOAD_TYPE_COLOR_4F = IMGUI_PAYLOAD_TYPE_COLOR_4F or "_COL4F"

S.color = { color = ImVec4(114.0 / 255.0, 144.0 / 255.0, 154.0 / 255.0, 200.0 / 255.0), base_flags = 0, palette = nil,
    backup = ImVec4(), no_border = false, ref_color = false, ref_color_v = ImVec4(1.0, 0.0, 1.0, 0.5), picker_mode = 0,
    display_mode = 0, picker_flags = ImGuiColorEditFlags.AlphaBar, hsv = ImVec4(0.23, 1.0, 1.0, 1.0) }

function DemoWindowWidgetsColorAndPickers()
    if not ImGui.TreeNode("Color/Picker Widgets") then return end
    local s = S.color
    local CE = ImGuiColorEditFlags
    local color = s.color

    ImGui.SeparatorText("Options")
    _, s.base_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_NoAlpha", s.base_flags, CE.NoAlpha)
    _, s.base_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_AlphaOpaque", s.base_flags, CE.AlphaOpaque)
    _, s.base_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_AlphaNoBg", s.base_flags, CE.AlphaNoBg)
    _, s.base_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_AlphaPreviewHalf", s.base_flags, CE.AlphaPreviewHalf)
    _, s.base_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_NoOptions", s.base_flags, CE.NoOptions); ImGui.SameLine(); HelpMarker("Right-click on the individual color widget to show options.")
    _, s.base_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_NoDragDrop", s.base_flags, CE.NoDragDrop)
    if CE.NoColorMarkers then _, s.base_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_NoColorMarkers", s.base_flags, CE.NoColorMarkers) end
    _, s.base_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_HDR", s.base_flags, CE.HDR); ImGui.SameLine(); HelpMarker("Currently all this does is to lift the 0..1 limits on dragging widgets.")
    local base_flags = s.base_flags

    ImGui.SeparatorText("Inline color editor")
    ImGui.Text("Color widget:")
    ImGui.SameLine(); HelpMarker("Click on the color square to open a color picker.\nCtrl+Click on individual component to input value.\n")
    ImGui.ColorEdit3("MyColor##1", color, base_flags)
    ImGui.Text("Color widget HSV with Alpha:")
    ImGui.ColorEdit4("MyColor##2", color, bit32.bor(CE.DisplayHSV, base_flags))
    ImGui.Text("Color widget with Float Display:")
    ImGui.ColorEdit4("MyColor##2f", color, bit32.bor(CE.Float, base_flags))
    ImGui.Text("Color button with Picker:")
    ImGui.SameLine(); HelpMarker("With the ImGuiColorEditFlags_NoInputs flag you can hide all the slider/text inputs.\nWith the ImGuiColorEditFlags_NoLabel flag you can pass a non-empty label which will only be used for the tooltip and picker popup.")
    ImGui.ColorEdit4("MyColor##3", color, bit32.bor(CE.NoInputs, CE.NoLabel, base_flags))

    ImGui.Text("Color button with Custom Picker Popup:")

    -- Generate a default palette. The palette will persist and can be edited.
    if s.palette == nil then
        s.palette = {}
        for n = 0, 31 do s.palette[n] = HSV(n / 31.0, 0.8, 0.8, 1.0) end -- Alpha = 1.0
    end
    local open_popup = ImGui.ColorButton("MyColor##3b", color, base_flags)
    ImGui.SameLine(0, ImGui.GetStyle().ItemInnerSpacing.x)
    open_popup = ImGui.Button("Palette") or open_popup
    if open_popup then
        ImGui.OpenPopup("mypicker")
        ImVec4_Copy(s.backup, color)
    end
    if ImGui.BeginPopup("mypicker") then
        ImGui.Text("MY CUSTOM COLOR PICKER WITH AN AMAZING PALETTE!")
        ImGui.Separator()
        ImGui.ColorPicker4("##picker", color, bit32.bor(base_flags, CE.NoSidePreview, CE.NoSmallPreview))
        ImGui.SameLine()
        ImGui.BeginGroup() -- Lock X position
        ImGui.Text("Current")
        ImGui.ColorButton("##current", color, bit32.bor(CE.NoPicker, CE.AlphaPreviewHalf), ImVec2(60, 40))
        ImGui.Text("Previous")
        if ImGui.ColorButton("##previous", s.backup, bit32.bor(CE.NoPicker, CE.AlphaPreviewHalf), ImVec2(60, 40)) then
            ImVec4_Copy(color, s.backup)
        end
        ImGui.Separator()
        ImGui.Text("Palette")
        for n = 0, 31 do
            ImGui.PushID(n)
            if n % 8 ~= 0 then ImGui.SameLine(0.0, ImGui.GetStyle().ItemSpacing.y) end
            local pal = s.palette[n]
            if ImGui.ColorButton("##palette", pal, bit32.bor(CE.NoAlpha, CE.NoPicker, CE.NoTooltip), ImVec2(20, 20)) then
                color.x = pal.x; color.y = pal.y; color.z = pal.z -- Preserve alpha!
            end

            -- Allow user to drop colors into each palette entry. Note that ColorButton() is already a
            -- drag source by default, unless specifying the ImGuiColorEditFlags.NoDragDrop flag.
            if ImGui.BeginDragDropTarget() then
                local payload = ImGui.AcceptDragDropPayload(IMGUI_PAYLOAD_TYPE_COLOR_3F)
                if payload and payload.Data then pal.x, pal.y, pal.z = payload.Data[1], payload.Data[2], payload.Data[3] end
                payload = ImGui.AcceptDragDropPayload(IMGUI_PAYLOAD_TYPE_COLOR_4F)
                if payload and payload.Data then pal.x, pal.y, pal.z, pal.w = payload.Data[1], payload.Data[2], payload.Data[3], payload.Data[4] end
                ImGui.EndDragDropTarget()
            end
            ImGui.PopID()
        end
        ImGui.EndGroup()
        ImGui.EndPopup()
    end

    ImGui.Text("Color button only:")
    _, s.no_border = ImGui.Checkbox("ImGuiColorEditFlags_NoBorder", s.no_border)
    ImGui.ColorButton("MyColor##3c", color, bit32.bor(base_flags, s.no_border and CE.NoBorder or 0), ImVec2(80, 80))

    ImGui.SeparatorText("Color picker")
    ImGui.PushID("Color picker")
    _, s.picker_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_NoAlpha", s.picker_flags, CE.NoAlpha)
    _, s.picker_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_AlphaBar", s.picker_flags, CE.AlphaBar)
    _, s.picker_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_NoSidePreview", s.picker_flags, CE.NoSidePreview)
    if bit32.band(s.picker_flags, CE.NoSidePreview) ~= 0 then
        ImGui.SameLine()
        _, s.ref_color = ImGui.Checkbox("With Ref Color", s.ref_color)
        if s.ref_color then
            ImGui.SameLine()
            ImGui.ColorEdit4("##RefColor", s.ref_color_v, bit32.bor(CE.NoInputs, base_flags))
        end
    end
    _, s.picker_flags = ImGui.CheckboxFlags("ImGuiColorEditFlags_PickerNoRotate", s.picker_flags, CE.PickerNoRotate)
    s.picker_mode = ImGui.Combo("Picker Mode", s.picker_mode, "Auto/Current\0ImGuiColorEditFlags_PickerHueBar\0ImGuiColorEditFlags_PickerHueWheel\0")
    ImGui.SameLine(); HelpMarker("When not specified explicitly, user can right-click the picker to change mode.")
    s.display_mode = ImGui.Combo("Display Mode", s.display_mode, "Auto/Current\0ImGuiColorEditFlags_NoInputs\0ImGuiColorEditFlags_DisplayRGB\0ImGuiColorEditFlags_DisplayHSV\0ImGuiColorEditFlags_DisplayHex\0")
    ImGui.SameLine(); HelpMarker("ColorEdit defaults to displaying RGB inputs if you don't specify a display mode, but the user can change it with a right-click on those inputs.\n\nColorPicker defaults to displaying RGB+HSV+Hex if you don't specify a display mode.\n\nYou can change the defaults using io.ConfigColorEditFlags.")
    local flags = bit32.bor(base_flags, s.picker_flags)
    if s.picker_mode == 1 then flags = bit32.bor(flags, CE.PickerHueBar) end
    if s.picker_mode == 2 then flags = bit32.bor(flags, CE.PickerHueWheel) end
    if s.display_mode == 1 then flags = bit32.bor(flags, CE.NoInputs) end -- Disable all RGB/HSV/Hex displays
    if s.display_mode == 2 then flags = bit32.bor(flags, CE.DisplayRGB) end -- Override display mode
    if s.display_mode == 3 then flags = bit32.bor(flags, CE.DisplayHSV) end
    if s.display_mode == 4 then flags = bit32.bor(flags, CE.DisplayHex) end
    ImGui.ColorPicker4("MyColor##4", color, flags, s.ref_color and s.ref_color_v or nil)

    ImGui.Text("Set defaults in code:")
    ImGui.SameLine(); HelpMarker("io.ConfigColorEditFlags is designed to allow you to set boot-time default.")
    if ImGui.Button("Overwrite default: Uint8 + HSV + Hue Bar") then
        ImGui.GetIO().ConfigColorEditFlags = bit32.bor(CE.Uint8, CE.DisplayHSV, CE.PickerHueBar, CE.InputRGB) -- [port] + InputRGB: upstream omits it and then trips its own InputMask_ assert
    end
    if ImGui.Button("Overwrite default: Float + HDR + Hue Wheel") then
        ImGui.GetIO().ConfigColorEditFlags = bit32.bor(CE.Float, CE.HDR, CE.PickerHueWheel, CE.DisplayRGB, CE.InputRGB)
    end

    -- Always display a small version of both types of pickers
    -- (that's in order to make it more visible in the demo to people who are skimming quickly through it)
    ImGui.Text("Both types:")
    local w = (ImGui.GetContentRegionAvail().x - ImGui.GetStyle().ItemSpacing.y) * 0.40
    ImGui.SetNextItemWidth(w)
    ImGui.ColorPicker3("##MyColor##5", color, bit32.bor(CE.PickerHueBar, CE.NoSidePreview, CE.NoInputs, CE.NoAlpha))
    ImGui.SameLine()
    ImGui.SetNextItemWidth(w)
    ImGui.ColorPicker3("##MyColor##6", color, bit32.bor(CE.PickerHueWheel, CE.NoSidePreview, CE.NoInputs, CE.NoAlpha))
    ImGui.PopID()

    -- HSV encoded support (to avoid RGB<>HSV round trips and singularities when S==0 or V==0)
    -- (s.hsv is stored as HSV!)
    ImGui.Spacing()
    ImGui.Text("HSV encoded colors")
    ImGui.SameLine(); HelpMarker("By default, colors are given to ColorEdit and ColorPicker in RGB, but ImGuiColorEditFlags_InputHSV allows you to store colors as HSV and pass them to ColorEdit and ColorPicker as HSV.")
    ImGui.Text("Color widget with InputHSV:")
    ImGui.ColorEdit4("HSV shown as RGB##1", s.hsv, bit32.bor(CE.DisplayRGB, CE.InputHSV, CE.Float))
    ImGui.ColorEdit4("HSV shown as HSV##1", s.hsv, bit32.bor(CE.DisplayHSV, CE.InputHSV, CE.Float))
    ImGui.DragFloat4("Raw HSV values", s.hsv, 0.01, 0.0, 1.0)
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsComboBoxes()
-------------------------------------------------------------------------------

S.combo = { flags = 0, sel = 0, filter = nil, c2 = 0, c3 = -1, c4 = 0 } -- sel: Here we store our selection data as an index.
function DemoWindowWidgetsComboBoxes()
    if not ImGui.TreeNode("Combo") then return end
    local s = S.combo
    local CF = ImGuiComboFlags
    local p
    -- Combo Boxes are also called "Dropdown" in other systems
    -- Expose flags as checkbox for the demo
    _, s.flags = ImGui.CheckboxFlags("ImGuiComboFlags_PopupAlignLeft", s.flags, CF.PopupAlignLeft)
    ImGui.SameLine(); HelpMarker("Only makes a difference if the popup is larger than the combo")
    p, s.flags = ImGui.CheckboxFlags("ImGuiComboFlags_NoArrowButton", s.flags, CF.NoArrowButton)
    if p then s.flags = bit32.band(s.flags, bit32.bnot(CF.NoPreview)) end -- Clear incompatible flags
    p, s.flags = ImGui.CheckboxFlags("ImGuiComboFlags_NoPreview", s.flags, CF.NoPreview)
    if p then s.flags = bit32.band(s.flags, bit32.bnot(bit32.bor(CF.NoArrowButton, CF.WidthFitPreview))) end -- Clear incompatible flags
    p, s.flags = ImGui.CheckboxFlags("ImGuiComboFlags_WidthFitPreview", s.flags, CF.WidthFitPreview)
    if p then s.flags = bit32.band(s.flags, bit32.bnot(CF.NoPreview)) end

    -- Override default popup height
    for _, h in ipairs({ "HeightSmall", "HeightRegular", "HeightLargest" }) do
        p, s.flags = ImGui.CheckboxFlags("ImGuiComboFlags_" .. h, s.flags, CF[h])
        if p then s.flags = bit32.band(s.flags, bit32.bnot(bit32.band(CF.HeightMask_, bit32.bnot(CF[h])))) end
    end

    -- Using the generic BeginCombo() API, you have full control over how to display the combo contents.
    -- (your selection data could be an index, a pointer to the object, an id for the object, a flag intrusively
    -- stored in the object itself, etc.)
    local items = { "AAAA", "BBBB", "CCCC", "DDDD", "EEEE", "FFFF", "GGGG", "HHHH", "IIII", "JJJJ", "KKKK", "LLLLLLL", "MMMM", "OOOOOOO" }

    -- Pass in the preview value visible before opening the combo (it could technically be different contents or not pulled from items[])
    local combo_preview_value = items[s.sel + 1]
    if ImGui.BeginCombo("combo 1", combo_preview_value, s.flags) then
        for n = 0, #items - 1 do
            local is_selected = (s.sel == n)
            if ImGui.Selectable(items[n + 1], is_selected) then s.sel = n end

            -- Set the initial focus when opening the combo (scrolling + keyboard navigation focus)
            if is_selected then ImGui.SetItemDefaultFocus() end
        end
        ImGui.EndCombo()
    end

    -- Show case embedding a filter using a simple trick: displaying the filter inside combo contents.
    -- See https://github.com/ocornut/imgui/issues/718 for advanced/esoteric alternatives.
    if ImGui.BeginCombo("combo 2 (w/ filter)", combo_preview_value, s.flags) then
        s.filter = s.filter or ImGuiTextFilter()
        if ImGui.IsWindowAppearing() then
            ImGui.SetKeyboardFocusHere()
            s.filter:Clear()
        end
        ImGui.SetNextItemShortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.F))
        ImGui.SetNextItemWidth(-FLT_MIN)
        s.filter:DrawWithHint("##Filter", "Filter (incl -excl)")
        for n = 0, #items - 1 do
            local is_selected = (s.sel == n)
            if s.filter:PassFilter(items[n + 1]) then
                if ImGui.Selectable(items[n + 1], is_selected) then s.sel = n end
            end
        end
        ImGui.EndCombo()
    end

    ImGui.Spacing()
    ImGui.SeparatorText("One-liner variants")
    HelpMarker("The Combo() function is not greatly useful apart from cases were you want to embed all options in a single strings.\nFlags above don't apply to this section.")

    -- Simplified one-liner Combo() API, using values packed in a single constant string
    -- This is a convenience for when the selection set is small and known at compile-time.
    s.c2 = ImGui.Combo("combo 3 (one-liner)", s.c2, "aaaa\0bbbb\0cccc\0dddd\0eeee\0\0")

    -- Simplified one-liner Combo() using an array of strings
    -- This is not very useful (may obsolete): prefer using BeginCombo()/EndCombo() for full control.
    s.c3 = ImGui.Combo("combo 4 (array)", s.c3, items, #items) -- If the selection isn't within 0..count, Combo won't display a preview

    -- Simplified one-liner Combo() using an accessor function
    s.c4 = ImGui.Combo("combo 5 (function)", s.c4, function(data, n) return data[n + 1] end, items, #items)
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsDataTypes()
-------------------------------------------------------------------------------

S.dt = { s8 = 127, u8 = 255, s16 = 32767, u16 = 65535, s32 = -1, u32 = 0xFFFFFFFF, s64 = -1, u64 = 0, f32 = 0.123, f64 = 90000.01234567890123456789,
    drag_clamp = false, inputs_step = true, flags = 0 }
function DemoWindowWidgetsDataTypes()
    if not ImGui.TreeNode("Data Types") then return end
    local s = S.dt
    local DT = ImGuiDataType
    -- DragScalar/InputScalar/SliderScalar functions allow various data types
    -- - signed/unsigned
    -- - 8/16/32/64-bits
    -- - integer/float/double
    -- To avoid polluting the public API with all possible combinations, we use the ImGuiDataType enum
    -- to pass the type.
    -- In practice, if you frequently use a given type that is not covered by the normal API entry points,
    -- you can wrap it yourself inside a 1 line function which can take typed argument as value,
    -- and then pass them to the generic function. For example:
    --   local function MySliderU32(label, value, min, max, format)
    --       return ImGui.SliderScalar(label, ImGuiDataType.U32, value, min or 0, max or 0, format or "%u")
    --   end

    -- ponytail: Luau numbers are doubles, so S64/U64 are shown with S32/Double here (no 64-bit integer type)
    -- Setup limits
    -- Note: SliderScalar() functions have a maximum usable range of half the natural type maximum, hence the /2.
    local s32_min, s32_max = math.floor(-2147483648 / 2), math.floor(2147483647 / 2)
    local u32_max = math.floor(4294967295 / 2)
    local drag_speed = 0.2
    ImGui.SeparatorText("Drags")
    _, s.drag_clamp = ImGui.Checkbox("Clamp integers to 0..50", s.drag_clamp)
    ImGui.SameLine(); HelpMarker("As with every widget in dear imgui, we never modify values unless there is a user interaction.\nYou can override the clamping limits by using Ctrl+Click to input a value.")
    local lo, hi = s.drag_clamp and 0 or nil, s.drag_clamp and 50 or nil
    s.s8  = ImGui.DragScalar("drag s8",      DT.S8,  s.s8,  drag_speed, lo, hi)
    s.u8  = ImGui.DragScalar("drag u8",      DT.U8,  s.u8,  drag_speed, lo, hi, "%u ms")
    s.s16 = ImGui.DragScalar("drag s16",     DT.S16, s.s16, drag_speed, lo, hi)
    s.u16 = ImGui.DragScalar("drag u16",     DT.U16, s.u16, drag_speed, lo, hi, "%u ms")
    s.s32 = ImGui.DragScalar("drag s32",     DT.S32, s.s32, drag_speed, lo, hi)
    s.s32 = ImGui.DragScalar("drag s32 hex", DT.S32, s.s32, drag_speed, lo, hi, "0x%08X")
    s.u32 = ImGui.DragScalar("drag u32",     DT.U32, s.u32, drag_speed, lo, hi, "%u ms")
    s.f32 = ImGui.DragScalar("drag float",     DT.Float,  s.f32, 0.005, 0.0, 1.0, "%f")
    s.f32 = ImGui.DragScalar("drag float log", DT.Float,  s.f32, 0.005, 0.0, 1.0, "%f", ImGuiSliderFlags.Logarithmic)
    s.f64 = ImGui.DragScalar("drag double",    DT.Double, s.f64, 0.0005, 0.0, nil, "%.10f grams")
    s.f64 = ImGui.DragScalar("drag double log",DT.Double, s.f64, 0.0005, 0.0, 1.0, "0 < %.10f < 1", ImGuiSliderFlags.Logarithmic)

    ImGui.SeparatorText("Sliders")
    s.s8  = ImGui.SliderScalar("slider s8 full",  DT.S8,  s.s8,  -128, 127, "%d")
    s.u8  = ImGui.SliderScalar("slider u8 full",  DT.U8,  s.u8,  0, 255, "%u")
    s.s16 = ImGui.SliderScalar("slider s16 full", DT.S16, s.s16, -32768, 32767, "%d")
    s.u16 = ImGui.SliderScalar("slider u16 full", DT.U16, s.u16, 0, 65535, "%u")
    s.s32 = ImGui.SliderScalar("slider s32 low",  DT.S32, s.s32, 0, 50, "%d")
    s.s32 = ImGui.SliderScalar("slider s32 high", DT.S32, s.s32, s32_max - 100, s32_max, "%d")
    s.s32 = ImGui.SliderScalar("slider s32 full", DT.S32, s.s32, s32_min, s32_max, "%d")
    s.s32 = ImGui.SliderScalar("slider s32 hex",  DT.S32, s.s32, 0, 50, "0x%04X")
    s.u32 = ImGui.SliderScalar("slider u32 low",  DT.U32, s.u32, 0, 50, "%u")
    s.u32 = ImGui.SliderScalar("slider u32 high", DT.U32, s.u32, u32_max - 100, u32_max, "%u")
    s.u32 = ImGui.SliderScalar("slider u32 full", DT.U32, s.u32, 0, u32_max, "%u")
    s.f32 = ImGui.SliderScalar("slider float low",      DT.Float, s.f32, 0.0, 1.0)
    s.f32 = ImGui.SliderScalar("slider float low log",  DT.Float, s.f32, 0.0, 1.0, "%.10f", ImGuiSliderFlags.Logarithmic)
    s.f32 = ImGui.SliderScalar("slider float high",     DT.Float, s.f32, -10000000000.0, 10000000000.0, "%e")
    s.f64 = ImGui.SliderScalar("slider double low",     DT.Double, s.f64, 0.0, 1.0, "%.10f grams")
    s.f64 = ImGui.SliderScalar("slider double low log", DT.Double, s.f64, 0.0, 1.0, "%.10f", ImGuiSliderFlags.Logarithmic)
    s.f64 = ImGui.SliderScalar("slider double high",    DT.Double, s.f64, -1000000000000000.0, 1000000000000000.0, "%e grams")

    ImGui.SeparatorText("Sliders (reverse)")
    s.s8  = ImGui.SliderScalar("slider s8 reverse",  DT.S8,  s.s8,  127, -128, "%d")
    s.u8  = ImGui.SliderScalar("slider u8 reverse",  DT.U8,  s.u8,  255, 0, "%u")
    s.s32 = ImGui.SliderScalar("slider s32 reverse", DT.S32, s.s32, 50, 0, "%d")
    s.u32 = ImGui.SliderScalar("slider u32 reverse", DT.U32, s.u32, 50, 0, "%u")

    ImGui.SeparatorText("Inputs")
    _, s.inputs_step = ImGui.Checkbox("Show step buttons", s.inputs_step)
    _, s.flags = ImGui.CheckboxFlags("ImGuiInputTextFlags_ReadOnly", s.flags, ImGuiInputTextFlags.ReadOnly)
    if ImGuiInputTextFlags.ParseEmptyRefVal then _, s.flags = ImGui.CheckboxFlags("ImGuiInputTextFlags_ParseEmptyRefVal", s.flags, ImGuiInputTextFlags.ParseEmptyRefVal) end
    if ImGuiInputTextFlags.DisplayEmptyRefVal then _, s.flags = ImGui.CheckboxFlags("ImGuiInputTextFlags_DisplayEmptyRefVal", s.flags, ImGuiInputTextFlags.DisplayEmptyRefVal) end
    local one = s.inputs_step and 1 or nil
    s.s8  = ImGui.InputScalar("input s8",      DT.S8,  s.s8,  one, nil, "%d", s.flags)
    s.u8  = ImGui.InputScalar("input u8",      DT.U8,  s.u8,  one, nil, "%u", s.flags)
    s.s16 = ImGui.InputScalar("input s16",     DT.S16, s.s16, one, nil, "%d", s.flags)
    s.u16 = ImGui.InputScalar("input u16",     DT.U16, s.u16, one, nil, "%u", s.flags)
    s.s32 = ImGui.InputScalar("input s32",     DT.S32, s.s32, one, nil, "%d", s.flags)
    s.s32 = ImGui.InputScalar("input s32 hex", DT.S32, s.s32, one, nil, "%04X", s.flags)
    s.u32 = ImGui.InputScalar("input u32",     DT.U32, s.u32, one, nil, "%u", s.flags)
    s.u32 = ImGui.InputScalar("input u32 hex", DT.U32, s.u32, one, nil, "%08X", s.flags)
    s.f32 = ImGui.InputScalar("input float",   DT.Float,  s.f32, s.inputs_step and 1.0 or nil, nil, nil, s.flags)
    s.f64 = ImGui.InputScalar("input double",  DT.Double, s.f64, s.inputs_step and 1.0 or nil, nil, nil, s.flags)
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsDisableBlocks()
-------------------------------------------------------------------------------

function DemoWindowWidgetsDisableBlocks(demo_data)
    if not ImGui.TreeNode("Disable Blocks") then return end
    _, demo_data.DisableSections = ImGui.Checkbox("Disable entire section above", demo_data.DisableSections)
    ImGui.SameLine(); HelpMarker("Demonstrate using BeginDisabled()/EndDisabled() across other sections.")
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsDragAndDrop()
-------------------------------------------------------------------------------

S.dnd = { col1 = { 1.0, 0.0, 0.2 }, col2 = { 0.4, 0.7, 0.0, 0.5 }, mode = 0,
    names = { "Bobby", "Beatrice", "Betty", "Brianna", "Barry", "Bernard", "Bibi", "Blaine", "Bryn" },
    item_names = { "Item One", "Item Two", "Item Three", "Item Four", "Item Five" }, col4 = ImVec4(1.0, 0.0, 0.2, 1.0) }
function DemoWindowWidgetsDragAndDrop()
    if not ImGui.TreeNode("Drag and Drop") then return end
    local s = S.dnd
    if ImGui.TreeNode("Drag and drop in standard widgets") then
        -- ColorEdit widgets automatically act as drag source and drag target.
        -- They are using standardized payload strings IMGUI_PAYLOAD_TYPE_COLOR_3F and IMGUI_PAYLOAD_TYPE_COLOR_4F
        -- to allow your own widgets to use colors in their drag and drop interaction.
        -- Also see 'Demo->Widgets->Color/Picker Widgets->Palette' demo.
        HelpMarker("You can drag from the color squares.")
        ImGui.ColorEdit3("color 1", s.col1)
        ImGui.ColorEdit4("color 2", s.col2)
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Drag and drop to copy/swap items") then
        local Mode_Copy, Mode_Move, Mode_Swap = 0, 1, 2
        if ImGui.RadioButtonEx("Copy", s.mode == Mode_Copy) then s.mode = Mode_Copy end ImGui.SameLine()
        if ImGui.RadioButtonEx("Move", s.mode == Mode_Move) then s.mode = Mode_Move end ImGui.SameLine()
        if ImGui.RadioButtonEx("Swap", s.mode == Mode_Swap) then s.mode = Mode_Swap end
        local names = s.names
        for n = 0, #names - 1 do
            ImGui.PushID(n)
            if n % 3 ~= 0 then ImGui.SameLine() end
            ImGui.Button(names[n + 1], ImVec2(60, 60))

            -- Our buttons are both drag sources and drag targets here!
            if ImGui.BeginDragDropSource(ImGuiDragDropFlags.None) then
                -- Set payload to carry the index of our item (could be anything)
                ImGui.SetDragDropPayload("DND_DEMO_CELL", n, 4)

                -- Display preview (could be anything, e.g. when dragging an image we could decide to display
                -- the filename and a small preview of the image, etc.)
                if s.mode == Mode_Copy then ImGui.Text("Copy %s", names[n + 1]) end
                if s.mode == Mode_Move then ImGui.Text("Move %s", names[n + 1]) end
                if s.mode == Mode_Swap then ImGui.Text("Swap %s", names[n + 1]) end
                ImGui.EndDragDropSource()
            end
            if ImGui.BeginDragDropTarget() then
                local payload = ImGui.AcceptDragDropPayload("DND_DEMO_CELL")
                if payload then
                    local payload_n = payload.Data
                    if s.mode == Mode_Copy then names[n + 1] = names[payload_n + 1] end
                    if s.mode == Mode_Move then names[n + 1] = names[payload_n + 1]; names[payload_n + 1] = "" end
                    if s.mode == Mode_Swap then names[n + 1], names[payload_n + 1] = names[payload_n + 1], names[n + 1] end
                end
                ImGui.EndDragDropTarget()
            end
            ImGui.PopID()
        end
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Drag to reorder items (simple)") then
        -- FIXME: there is temporary (usually single-frame) ID Conflict during reordering as a same item may be submitting twice.
        -- This code was always slightly faulty but in a way which was not easily noticeable.
        -- Until we fix this, enable ImGuiItemFlags.AllowDuplicateId to disable detecting the issue.
        ImGui.PushItemFlag(ImGuiItemFlags.AllowDuplicateId, true)

        -- Simple reordering
        HelpMarker("We don't use the drag and drop api at all here! Instead we query when the item is held but not hovered, and order items accordingly.")
        local item_names = s.item_names
        for n = 1, #item_names do
            local item = item_names[n]
            ImGui.Selectable(item)
            if ImGui.IsItemActive() and not ImGui.IsItemHovered() then
                local n_next = n + ((ImGui.GetMouseDragDelta(0).y < 0.0) and -1 or 1)
                if n_next >= 1 and n_next <= #item_names then
                    item_names[n] = item_names[n_next]
                    item_names[n_next] = item
                    ImGui.ResetMouseDragDelta()
                end
            end
        end
        ImGui.PopItemFlag()
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Tooltip at target location") then
        for n = 0, 1 do
            -- Drop targets
            ImGui.Button((n == 1) and "drop here##1" or "drop here##0")
            if ImGui.BeginDragDropTarget() then
                local drop_target_flags = bit32.bor(ImGuiDragDropFlags.AcceptBeforeDelivery, ImGuiDragDropFlags.AcceptNoPreviewTooltip)
                if ImGui.AcceptDragDropPayload(IMGUI_PAYLOAD_TYPE_COLOR_4F, drop_target_flags) then
                    ImGui.SetMouseCursor(ImGuiMouseCursor.NotAllowed)
                    ImGui.SetTooltip("Cannot drop here!")
                end
                ImGui.EndDragDropTarget()
            end

            -- Drop source
            if n == 0 then ImGui.ColorButton("drag me", s.col4) end
        end
        ImGui.TreePop()
    end
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsDragsAndSliders()
-------------------------------------------------------------------------------

S.ds = { flags = 0, drag_f = 0.5, drag_f4 = { 0, 0, 0, 0 }, drag_i = 50, slider_f = 0.5, slider_f4 = { 0, 0, 0, 0 }, slider_i = 50 }
function DemoWindowWidgetsDragsAndSliders()
    if not ImGui.TreeNode("Drag/Slider Flags") then return end
    -- Demonstrate using advanced flags for DragXXX and SliderXXX functions. Note that the flags are the same!
    local s = S.ds
    local SF = ImGuiSliderFlags
    local function F(name, help)
        if SF[name] == nil then return end
        _, s.flags = ImGui.CheckboxFlags("ImGuiSliderFlags_" .. name, s.flags, SF[name])
        if help then ImGui.SameLine(); HelpMarker(help) end
    end
    F("AlwaysClamp")
    F("ClampOnInput", "Clamp value to min/max bounds when input manually with Ctrl+Click. By default Ctrl+Click allows going out of bounds.")
    F("ClampZeroRange", "Clamp even if min==max==0.0f. Otherwise DragXXX functions don't clamp.")
    F("Logarithmic", "Enable logarithmic editing (more precision for small values).")
    F("NoRoundToFormat", "Disable rounding underlying value to match precision of the format string (e.g. %.3f values are rounded to those 3 digits).")
    F("NoInput", "Disable Ctrl+Click or Enter key allowing to input text directly into the widget.")
    F("NoSpeedTweaks", "Disable keyboard modifiers altering tweak speed. Useful if you want to alter tweak speed yourself based on your own logic.")
    F("WrapAround", "Enable wrapping around from max to min and from min to max (only supported by DragXXX() functions)")
    F("ColorMarkers")
    local flags = s.flags

    -- Drags
    ImGui.Text("Underlying float value: %f", s.drag_f)
    s.drag_f = ImGui.DragFloat("DragFloat (0 -> 1)", s.drag_f, 0.005, 0.0, 1.0, "%.3f", flags)
    s.drag_f = ImGui.DragFloat("DragFloat (0 -> +inf)", s.drag_f, 0.005, 0.0, FLT_MAX, "%.3f", flags)
    s.drag_f = ImGui.DragFloat("DragFloat (-inf -> 1)", s.drag_f, 0.005, -FLT_MAX, 1.0, "%.3f", flags)
    s.drag_f = ImGui.DragFloat("DragFloat (-inf -> +inf)", s.drag_f, 0.005, -FLT_MAX, FLT_MAX, "%.3f", flags)
    -- ImGui.DragFloat("DragFloat (0 -> 0)", drag_f, 0.005, 0.0, 0.0, "%.3f", flags)           -- To test ClampZeroRange
    -- ImGui.DragFloat("DragFloat (100 -> 100)", drag_f, 0.005, 100.0, 100.0, "%.3f", flags)
    s.drag_i = ImGui.DragInt("DragInt (0 -> 100)", s.drag_i, 0.5, 0, 100, "%d", flags)
    ImGui.DragFloat4("DragFloat4 (0 -> 1)", s.drag_f4, 0.005, 0.0, 1.0, "%.3f", flags) -- Multi-component item, mostly here to document the effect of ImGuiSliderFlags.ColorMarkers.

    -- Sliders
    local flags_for_sliders = bit32.band(flags, bit32.bnot(SF.WrapAround))
    ImGui.Text("Underlying float value: %f", s.slider_f)
    s.slider_f = ImGui.SliderFloat("SliderFloat (0 -> 1)", s.slider_f, 0.0, 1.0, "%.3f", flags_for_sliders)
    s.slider_i = ImGui.SliderInt("SliderInt (0 -> 100)", s.slider_i, 0, 100, "%d", flags_for_sliders)
    ImGui.SliderFloat4("SliderFloat4 (0 -> 1)", s.slider_f4, 0.0, 1.0, "%.3f", flags_for_sliders) -- Multi-component item, mostly here to document the effect of ImGuiSliderFlags.ColorMarkers.
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsFonts()
-------------------------------------------------------------------------------

function DemoWindowWidgetsFonts()
    if not ImGui.TreeNode("Fonts") then return end
    if ImGui.ShowFontAtlas then ImGui.ShowFontAtlas(ImGui.GetIO().Fonts) else DemoNotPorted("ShowFontAtlas") end
    -- FIXME-NEWATLAS: Provide a demo to add/create a procedural font?
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsImages()
-------------------------------------------------------------------------------

S.img = { viewer = nil, pressed_count = 0 }
function DemoWindowWidgetsImages()
    if not ImGui.TreeNode("Images") then return end
    local s = S.img
    local io = ImGui.GetIO()
    ImGui.TextWrapped("Below we are displaying the font texture (which is the only texture we have access to in this demo). Use the 'ImTextureID' type as storage to pass pointers or identifier to your own texture data. Hover the texture for a zoomed view!")

    -- Below we are displaying the font texture because it is the only texture we have access to inside the demo!
    -- Read description about ImTextureID/ImTextureRef and FAQ for details about texture identifiers.
    -- - You can use ShowMetricsWindow() to inspect the draw data that are being passed to your renderer,
    --   it will help you debug issues if you are confused about it.
    -- - Consider using the lower-level ImDrawList:AddImage() API, via ImGui.GetWindowDrawList():AddImage().
    -- - Read https://github.com/ocornut/imgui/blob/master/docs/FAQ.md
    -- - Read https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples

    -- Grab the current texture identifier used by the font atlas.
    local atlas = io.Fonts
    local my_tex_id = atlas.TexRef
    local my_tex_w = atlas.TexData and atlas.TexData.Width or 0 -- Regular user code should never have to care about TexData fields, but since we want to display the entire texture here, we pull Width/Height from it.
    local my_tex_h = atlas.TexData and atlas.TexData.Height or 0
    ImGui.Text("%.0fx%.0f", my_tex_w, my_tex_h)

    -- Basic drawing
    ImGui.SeparatorText("Image()/ImageWithBg() function")
    ImGui.PushStyleVar(ImGuiStyleVar.ImageBorderSize, math.max(1.0, ImGui.GetStyle().ImageBorderSize))
    ImGui.ImageWithBg(my_tex_id, ImVec2(my_tex_w, my_tex_h), ImVec2(0.0, 0.0), ImVec2(1.0, 1.0), ImVec4(0.0, 0.0, 0.0, 1.0)) -- uv_min: Top-left, uv_max: Lower-right
    ImGui.PopStyleVar()

    -- Fancy widget
    ImGui.SeparatorText("Interactive Image Viewer")
    s.viewer = s.viewer or ExampleImageViewerData()
    local canvas_size = ImVec2(ImGui.GetContentRegionAvail().x, my_tex_h * 2.0)
    ExampleImageViewer_DrawOptions(s.viewer)
    ExampleImageViewer_DrawCanvas(s.viewer, canvas_size, my_tex_id, my_tex_w, my_tex_h)

    ImGui.SeparatorText("Textured Buttons")
    ImGui.TextWrapped("And now some textured buttons..")
    for i = 0, 7 do
        -- UV coordinates are often (0.0, 0.0) and (1.0, 1.0) to display an entire textures.
        -- Here are trying to display only a 32x32 pixels area of the texture, hence the UV computation.
        -- Read about UV coordinates here: https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples
        ImGui.PushID(i)
        if i > 0 then ImGui.PushStyleVar(ImGuiStyleVar.FramePadding, ImVec2(i - 1.0, i - 1.0)) end
        local size = ImVec2(32.0, 32.0)                         -- Size of the image we want to make visible
        local uv0 = ImVec2(0.0, 0.0)                            -- UV coordinates for lower-left
        local uv1 = ImVec2(32.0 / my_tex_w, 32.0 / my_tex_h)    -- UV coordinates for (32,32) in our texture
        -- bg_col: Black background, tint_col: No tint
        if ImGui.ImageButton("", my_tex_id, size, uv0, uv1, ImVec4(0.0, 0.0, 0.0, 1.0), ImVec4(1.0, 1.0, 1.0, 1.0)) then
            s.pressed_count = s.pressed_count + 1
        end
        if i > 0 then ImGui.PopStyleVar() end
        ImGui.PopID()
        ImGui.SameLine()
    end
    ImGui.NewLine()
    ImGui.Text("Pressed %d times.", s.pressed_count)
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsListBoxes()
-------------------------------------------------------------------------------

S.lb = { sel = 0, highlight = false } -- sel: Here we store our selected data as an index.
function DemoWindowWidgetsListBoxes()
    if not ImGui.TreeNode("List Boxes") then return end
    -- BeginListBox() is essentially a thin wrapper to using BeginChild()/EndChild()
    -- using the ImGuiChildFlags.FrameStyle flag for stylistic changes + displaying a label.
    -- You may be tempted to simply use BeginChild() directly. However note that BeginChild() requires EndChild()
    -- to always be called (inconsistent with BeginListBox()/EndListBox()).

    -- Using the generic BeginListBox() API, you have full control over how to display the combo contents.
    -- (your selection data could be an index, a pointer to the object, an id for the object, a flag intrusively
    -- stored in the object itself, etc.)
    local s = S.lb
    local items = { "AAAA", "BBBB", "CCCC", "DDDD", "EEEE", "FFFF", "GGGG", "HHHH", "IIII", "JJJJ", "KKKK", "LLLLLLL", "MMMM", "OOOOOOO" }
    local item_highlighted_idx = -1 -- Here we store our highlighted data as an index.
    _, s.highlight = ImGui.Checkbox("Highlight hovered item in second listbox", s.highlight)
    if ImGui.BeginListBox("listbox 1") then
        for n = 0, #items - 1 do
            local is_selected = (s.sel == n)
            if ImGui.Selectable(items[n + 1], is_selected) then s.sel = n end
            if s.highlight and ImGui.IsItemHovered() then item_highlighted_idx = n end
            -- Set the initial focus when opening the combo (scrolling + keyboard navigation focus)
            if is_selected then ImGui.SetItemDefaultFocus() end
        end
        ImGui.EndListBox()
    end
    ImGui.SameLine(); HelpMarker("Here we are sharing selection state between both boxes.")

    -- Custom size: use all width, 5 items tall
    ImGui.Text("Full-width:")
    if ImGui.BeginListBox("##listbox 2", ImVec2(-FLT_MIN, 5 * ImGui.GetTextLineHeightWithSpacing())) then
        for n = 0, #items - 1 do
            local is_selected = (s.sel == n)
            local flags = (item_highlighted_idx == n) and ImGuiSelectableFlags.Highlight or 0
            if ImGui.Selectable(items[n + 1], is_selected, flags) then s.sel = n end
            -- Set the initial focus when opening the combo (scrolling + keyboard navigation focus)
            if is_selected then ImGui.SetItemDefaultFocus() end
        end
        ImGui.EndListBox()
    end
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsLiveEdit()
-------------------------------------------------------------------------------

S.le = { str = Buf("", 32), i = 0, f = 0.0 }
function DemoWindowWidgetsLiveEdit(demo_data)
    if not ImGui.TreeNode("Live Edit Flags") then return end
    local s = S.le
    ImGui.TextWrapped("Select whether to apply keyboard edits to backing variables _while_ typing.")
    _, demo_data.LiveEditOverride = ImGui.Checkbox("Override Live Edit Flags in Demo Window", demo_data.LiveEditOverride)
    if not demo_data.LiveEditOverride then demo_data.LiveEditFlags = ImGui.GetItemFlags() end
    ImGui.BeginDisabled(demo_data.LiveEditOverride == false)
    ImGui.Indent()
    _, demo_data.LiveEditFlags = ImGui.CheckboxFlags("ImGuiItemFlags_LiveEditOnInputText", demo_data.LiveEditFlags, ImGuiItemFlags.LiveEditOnInputText)
    _, demo_data.LiveEditFlags = ImGui.CheckboxFlags("ImGuiItemFlags_LiveEditOnInputScalar", demo_data.LiveEditFlags, ImGuiItemFlags.LiveEditOnInputScalar)
    ImGui.Unindent()
    ImGui.EndDisabled()
    ImGui.Text("Try typing '123' and seeing effect on backing value:")
    ImGui.InputText("str", s.str, 32)
    ImGui.Text("Backing value: \"%s\"", BufStr(s.str))
    s.i = ImGui.InputInt("int", s.i, 0, 0)
    ImGui.Text("Backing value: %d", s.i)
    s.f = ImGui.SliderFloat("float", s.f, 0.0, 100.0)
    ImGui.Text("Backing value: %f", s.f)
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsMixedValues()
-------------------------------------------------------------------------------

S.mv = { use_liveedit = false, items = { 12.0, 0.0, 0.0 } }
function DemoWindowWidgetsMixedValues()
    if not ImGui.TreeNode("Mixed Values") then return end
    local s = S.mv
    local items = s.items
    -- This is designed for advanced property editors which are generally reusable and data-driven.
    HelpMarker("Using ImGuiItemFlags_MixedValue.")
    _, s.use_liveedit = ImGui.Checkbox("ImGuiItemFlags_LiveEditOnInput", s.use_liveedit)
    ImGui.SeparatorText("Scalar/Text Widgets")
    local is_mixed = items[1] ~= items[2] or items[1] ~= items[3]

    -- Demonstrate Drags, Sliders, Inputs
    ImGui.PushItemFlag(ImGuiItemFlags.LiveEditOnInput, s.use_liveedit)
    ImGui.PushItemFlag(ImGuiItemFlags.MixedValue, is_mixed)
    local edited, e = false, false
    items[1], e = ImGui.DragFloat("DragFloat", items[1]); edited = edited or e
    items[1], e = ImGui.SliderFloat("SliderFloat", items[1], 0.0, 100.0); edited = edited or e
    items[1], e = ImGui.InputFloat("InputFloat", items[1], 1.0); edited = edited or e
    if edited then items[2] = items[1]; items[3] = items[1] end
    ImGui.PopItemFlag()
    ImGui.Text("Underlying data:")
    items[1] = ImGui.InputFloat("item 0 (ref)", items[1])
    items[2] = ImGui.InputFloat("item 1", items[2])
    items[3] = ImGui.InputFloat("item 2", items[3])
    ImGui.PopItemFlag()

    -- Demonstrate Checkbox(), RadioButton(), Combo(), ColorEdit4()
    ImGui.SeparatorText("Others Widgets")
    ImGui.Text("(note: edits are not applied in this demo)") -- <-- Would need more state tracking.
    ImGui.Checkbox("Checkbox On", true)
    ImGui.Checkbox("Checkbox Off", false)
    ImGui.PushItemFlag(ImGuiItemFlags.MixedValue, true)
    ImGui.Checkbox("Checkbox Mixed", false)
    ImGui.RadioButtonEx("RadioButton Mixed", true)
    ImGui.SameLine()
    ImGui.RadioButtonEx("RadioButton Mixed##2", true) -- Showing 2 radio buttons makes the example more clear
    ImGui.Combo("Combo", 0, "One\0Two\0Three\0")
    ImGui.ColorEdit4("ColorEdit4", ImVec4(0.5, 0.5, 0.5, 0.5))
    ImGui.PopItemFlag()
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsMultiComponents()
-------------------------------------------------------------------------------

S.mc = { vec4f = { 0.10, 0.20, 0.30, 0.44 }, vec4i = { 1, 5, 100, 255 }, flags = 0, b = 10, e = 90, bi = 100, ei = 1000 }
function DemoWindowWidgetsMultiComponents()
    if not ImGui.TreeNode("Multi-component Widgets") then return end
    local s = S.mc
    local f, i = s.vec4f, s.vec4i
    if ImGuiSliderFlags.ColorMarkers then _, s.flags = ImGui.CheckboxFlags("ImGuiSliderFlags_ColorMarkers", s.flags, ImGuiSliderFlags.ColorMarkers) end -- Only passing this to Drag/Sliders
    local flags = s.flags
    for _, n in ipairs({ 2, 3, 4 }) do
        ImGui.SeparatorText(n .. "-wide")
        ImGui["InputFloat" .. n]("input float" .. n, f)
        ImGui["InputInt" .. n]("input int" .. n, i)
        ImGui["DragFloat" .. n]("drag float" .. n, f, 0.01, 0.0, 1.0, nil, flags)
        ImGui["DragInt" .. n]("drag int" .. n, i, 1, 0, 255, nil, flags)
        ImGui["SliderFloat" .. n]("slider float" .. n, f, 0.0, 1.0, nil, flags)
        ImGui["SliderInt" .. n]("slider int" .. n, i, 0, 255, nil, flags)
    end
    ImGui.SeparatorText("Ranges")
    s.b, s.e = ImGui.DragFloatRange2("range float", s.b, s.e, 0.25, 0.0, 100.0, "Min: %.1f %%", "Max: %.1f %%", ImGuiSliderFlags.AlwaysClamp)
    s.bi, s.ei = ImGui.DragIntRange2("range int", s.bi, s.ei, 5, 0, 1000, "Min: %d units", "Max: %d units")
    s.bi, s.ei = ImGui.DragIntRange2("range int (no bounds)", s.bi, s.ei, 5, 0, 0, "Min: %d units", "Max: %d units")
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsPlotting()
-------------------------------------------------------------------------------

-- Plot/Graph widgets are not very good.
-- Consider using a third-party library such as ImPlot: https://github.com/epezent/implot
-- (see others https://github.com/ocornut/imgui/wiki/Useful-Extensions)
S.plot = { animate = true, arr = { 0.6, 0.1, 1.0, 0.5, 0.92, 0.1, 0.2 }, values = {}, values_offset = 0, refresh_time = 0.0, phase = 0.0,
    func_type = 0, display_count = 70 }
for n = 1, 90 do S.plot.values[n] = 0.0 end
function DemoWindowWidgetsPlotting()
    if not ImGui.TreeNode("Plotting") then return end
    local s = S.plot
    ImGui.Text("Need better plotting and graphing? Consider using ImPlot:")
    ImGui.TextLinkOpenURL("https://github.com/epezent/implot")
    ImGui.Separator()
    _, s.animate = ImGui.Checkbox("Animate", s.animate)

    -- Plot as lines and plot as histogram
    ImGui.PlotLines("Frame Times", s.arr, nil, #s.arr)
    ImGui.PlotHistogram("Histogram", s.arr, nil, #s.arr, 0, nil, 0.0, 1.0, ImVec2(0, 80.0))
    -- ImGui.SameLine(); HelpMarker("Consider using ImPlot instead!")

    -- Fill an array of contiguous float values to plot
    local values = s.values
    if not s.animate or s.refresh_time == 0.0 then s.refresh_time = ImGui.GetTime() end
    while s.refresh_time < ImGui.GetTime() do -- Create data at fixed 60 Hz rate for the demo
        values[s.values_offset + 1] = math.cos(s.phase)
        s.values_offset = (s.values_offset + 1) % #values
        s.phase = s.phase + 0.10 * s.values_offset
        s.refresh_time = s.refresh_time + 1.0 / 60.0
    end

    -- Plots can display overlay texts
    -- (in this example, we will display an average value)
    local average = 0.0
    for n = 1, #values do average = average + values[n] end
    average = average / #values
    ImGui.PlotLines("Lines", values, nil, #values, s.values_offset, string.format("avg %f", average), -1.0, 1.0, ImVec2(0, 80.0))

    -- Use functions to generate output
    -- FIXME: This is actually VERY awkward because current plot API only pass in indices.
    -- We probably want an API passing floats and user provide sample rate/count.
    -- Getters receive a 1-based index in this port
    local function Sin(_, i) return math.sin((i - 1) * 0.1) end
    local function Saw(_, i) return ((i - 1) % 2 == 1) and 1.0 or -1.0 end
    ImGui.SeparatorText("Functions")
    ImGui.SetNextItemWidth(ImGui.GetFontSize() * 8)
    s.func_type = ImGui.Combo("func", s.func_type, "Sin\0Saw\0")
    ImGui.SameLine()
    s.display_count = ImGui.SliderInt("Sample count", s.display_count, 1, 400)
    local func = (s.func_type == 0) and Sin or Saw
    ImGui.PlotLines("Lines##2", func, nil, s.display_count, 0, nil, -1.0, 1.0, ImVec2(0, 80))
    ImGui.PlotHistogram("Histogram##2", func, nil, s.display_count, 0, nil, -1.0, 1.0, ImVec2(0, 80))
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsProgressBars()
-------------------------------------------------------------------------------

S.pb = { accum = 0.0, dir = 1.0 }
function DemoWindowWidgetsProgressBars()
    if not ImGui.TreeNode("Progress Bars") then return end
    -- Animate a simple progress bar
    local s = S.pb
    s.accum = s.accum + s.dir * 0.4 * ImGui.GetIO().DeltaTime
    if s.accum >= 1.1 then s.accum = 1.1; s.dir = -s.dir end
    if s.accum <= -0.1 then s.accum = -0.1; s.dir = -s.dir end
    local progress = DemoClamp(s.accum, 0.0, 1.0)

    -- Typically we would use ImVec2(-1.0,0.0) or ImVec2(-FLT_MIN,0.0) to use all available width,
    -- or ImVec2(width,0.0) for a specified width. ImVec2(0.0,0.0) uses ItemWidth.
    ImGui.ProgressBar(progress, ImVec2(0.0, 0.0))
    ImGui.SameLine(0.0, ImGui.GetStyle().ItemInnerSpacing.x)
    ImGui.Text("Progress Bar")
    ImGui.ProgressBar(progress, ImVec2(0.0, 0.0), string.format("%d/%d", math.floor(progress * 1753), 1753))

    -- Pass an animated negative value, e.g. -1.0 * ImGui.GetTime() is the recommended value.
    -- Adjust the factor if you want to adjust the animation speed.
    ImGui.ProgressBar(-1.0 * ImGui.GetTime(), ImVec2(0.0, 0.0), "Searching..")
    ImGui.SameLine(0.0, ImGui.GetStyle().ItemInnerSpacing.x)
    ImGui.Text("Indeterminate")
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsQueryingStatuses()
-------------------------------------------------------------------------------

-- Selectable(label, bool* p_selected) overload: toggles on press
local function SelectableP(label, sel, flags, size)
    local pressed = ImGui.Selectable(label, sel, flags, size)
    if pressed then sel = not sel end
    return pressed, sel
end

local function B(v) return v and 1 or 0 end

S.qs = { item_type = 4, item_disabled = false, item_mixedvalue = false, liveedit_override = false, liveedit_flags = 0,
    b = false, col4f = { 1.0, 0.5, 0.0, 1.0 }, str = Buf("", 16), combo = 1, listbox = 1, unused = Buf("", 1),
    embed = false, test_window = false }
function DemoWindowWidgetsQueryingStatuses()
    local s = S.qs
    if ImGui.TreeNode("Querying Item Status (Edited/Active/Hovered etc.)") then
        -- Select an item type
        local item_names = { "Text", "Button", "Button (w/ repeat)", "Checkbox", "SliderFloat", "InputText", "InputTextMultiline", "InputFloat",
            "InputFloat3", "ColorEdit4", "Selectable", "MenuItem", "TreeNode", "TreeNode (w/ double-click)", "Combo", "ListBox" }
        s.item_type = ImGui.Combo("Item Type", s.item_type, item_names, #item_names, #item_names)
        ImGui.SameLine()
        HelpMarker("Testing how various types of items are interacting with the IsItemXXX functions. Note that the bool return value of most ImGui function is generally equivalent to calling ImGui::IsItemHovered().")
        _, s.item_disabled = ImGui.Checkbox("Item Disabled", s.item_disabled)
        _, s.item_mixedvalue = ImGui.Checkbox("Item MixedValue", s.item_mixedvalue)
        _, s.liveedit_override = ImGui.Checkbox("Override LiveEdit:", s.liveedit_override)
        ImGui.SameLine()
        if not s.liveedit_override then s.liveedit_flags = ImGui.GetItemFlags() end
        ImGui.BeginDisabled(s.liveedit_override == false)
        _, s.liveedit_flags = ImGui.CheckboxFlags("_LiveEditOnInput", s.liveedit_flags, ImGuiItemFlags.LiveEditOnInput)
        ImGui.SameLine()
        _, s.liveedit_flags = ImGui.CheckboxFlags("_LiveEditOnInputText", s.liveedit_flags, ImGuiItemFlags.LiveEditOnInputText)
        ImGui.SameLine()
        _, s.liveedit_flags = ImGui.CheckboxFlags("_LiveEditOnInputScalar", s.liveedit_flags, ImGuiItemFlags.LiveEditOnInputScalar)
        ImGui.EndDisabled()
        if s.liveedit_override then
            ImGui.PushItemFlag(ImGuiItemFlags.LiveEditOnInputText, bit32.band(s.liveedit_flags, ImGuiItemFlags.LiveEditOnInputText) ~= 0)
            ImGui.PushItemFlag(ImGuiItemFlags.LiveEditOnInputScalar, bit32.band(s.liveedit_flags, ImGuiItemFlags.LiveEditOnInputScalar) ~= 0)
        end

        -- Submit selected items so we can query their status in the code following it.
        local ret = false
        local t = s.item_type
        if s.item_disabled then ImGui.BeginDisabled(true) end
        if s.item_mixedvalue then ImGui.PushItemFlag(ImGuiItemFlags.MixedValue, true) end
        if t == 0 then ImGui.Text("ITEM: Text") end                                              -- Testing text items with no identifier/interaction
        if t == 1 then ret = ImGui.Button("ITEM: Button") end                                    -- Testing button
        if t == 2 then ImGui.PushItemFlag(ImGuiItemFlags.ButtonRepeat, true); ret = ImGui.Button("ITEM: Button"); ImGui.PopItemFlag() end -- Testing button (with repeater)
        if t == 3 then ret, s.b = ImGui.Checkbox("ITEM: Checkbox", s.b) end                      -- Testing checkbox
        if t == 4 then s.col4f[1], ret = ImGui.SliderFloat("ITEM: SliderFloat", s.col4f[1], 0.0, 1.0) end -- Testing basic item
        if t == 5 then ret = ImGui.InputText("ITEM: InputText", s.str, 16) end                   -- Testing input text (which handles tabbing)
        if t == 6 then ret = ImGui.InputTextMultiline("ITEM: InputTextMultiline", s.str, 16) end -- Testing input text (which uses a child window)
        if t == 7 then s.col4f[1], ret = ImGui.InputFloat("ITEM: InputFloat", s.col4f[1], 1.0) end -- Testing +/- buttons on scalar input
        if t == 8 then ret = ImGui.InputFloat3("ITEM: InputFloat3", s.col4f) end                 -- Testing multi-component items (IsItemXXX flags are reported merged)
        if t == 9 then ret = ImGui.ColorEdit4("ITEM: ColorEdit4", s.col4f) end                   -- Testing multi-component items (IsItemXXX flags are reported merged)
        if t == 10 then ret = ImGui.Selectable("ITEM: Selectable") end                           -- Testing selectable item
        if t == 11 then ret = ImGui.MenuItem("ITEM: MenuItem") end                               -- Testing menu item (they use ImGuiButtonFlags.PressedOnRelease button policy)
        if t == 12 then ret = ImGui.TreeNode("ITEM: TreeNode"); if ret then ImGui.TreePop() end end -- Testing tree node
        if t == 13 then ret = ImGui.TreeNodeEx("ITEM: TreeNode w/ ImGuiTreeNodeFlags_OpenOnDoubleClick", bit32.bor(ImGuiTreeNodeFlags.OpenOnDoubleClick, ImGuiTreeNodeFlags.NoTreePushOnOpen)) end -- Testing tree node with ImGuiButtonFlags.PressedOnDoubleClick button policy.
        if t == 14 then s.combo, ret = ImGui.Combo("ITEM: Combo", s.combo, { "Apple", "Banana", "Cherry", "Kiwi" }) end
        if t == 15 then s.listbox, ret = ImGui.ListBox("ITEM: ListBox", s.listbox, { "Apple", "Banana", "Cherry", "Kiwi" }, 4, 4) end

        local HF = ImGuiHoveredFlags
        local hovered_delay_none = ImGui.IsItemHovered()
        local hovered_delay_stationary = ImGui.IsItemHovered(HF.Stationary)
        local hovered_delay_short = ImGui.IsItemHovered(HF.DelayShort)
        local hovered_delay_normal = ImGui.IsItemHovered(HF.DelayNormal)
        local hovered_delay_tooltip = ImGui.IsItemHovered(HF.ForTooltip) -- = Normal + Stationary

        -- Display the values of IsItemHovered() and other common item state functions.
        -- Note that the ImGuiHoveredFlags.XXX flags can be combined.
        -- Because BulletText is an item itself and that would affect the output of IsItemXXX functions,
        -- we query every state in a single call to avoid storing them and to simplify the code.
        local rmin, rmax, rsize = ImGui.GetItemRectMin(), ImGui.GetItemRectMax(), ImGui.GetItemRectSize()
        ImGui.BulletText(
            "Return value = %d\nIsItemFocused() = %d\nIsItemHovered() = %d\nIsItemHovered(_AllowWhenBlockedByPopup) = %d\n" ..
            "IsItemHovered(_AllowWhenBlockedByActiveItem) = %d\nIsItemHovered(_AllowWhenOverlappedByItem) = %d\n" ..
            "IsItemHovered(_AllowWhenOverlappedByWindow) = %d\nIsItemHovered(_AllowWhenDisabled) = %d\nIsItemHovered(_RectOnly) = %d\n" ..
            "IsItemActive() = %d\nIsItemEdited() = %d\nIsItemActivated() = %d\nIsItemDeactivated() = %d\nIsItemDeactivatedAfterEdit() = %d\n" ..
            "IsItemVisible() = %d\nIsItemClicked() = %d\nIsItemToggledOpen() = %d\n" ..
            "GetItemRectMin() = (%.1f, %.1f)\nGetItemRectMax() = (%.1f, %.1f)\nGetItemRectSize() = (%.1f, %.1f)",
            B(ret), B(ImGui.IsItemFocused()), B(ImGui.IsItemHovered()), B(ImGui.IsItemHovered(HF.AllowWhenBlockedByPopup)),
            B(ImGui.IsItemHovered(HF.AllowWhenBlockedByActiveItem)), B(ImGui.IsItemHovered(HF.AllowWhenOverlappedByItem)),
            B(ImGui.IsItemHovered(HF.AllowWhenOverlappedByWindow)), B(ImGui.IsItemHovered(HF.AllowWhenDisabled)), B(ImGui.IsItemHovered(HF.RectOnly)),
            B(ImGui.IsItemActive()), B(ImGui.IsItemEdited()), B(ImGui.IsItemActivated()), B(ImGui.IsItemDeactivated()), B(ImGui.IsItemDeactivatedAfterEdit()),
            B(ImGui.IsItemVisible()), B(ImGui.IsItemClicked()), B(ImGui.IsItemToggledOpen()),
            rmin.x, rmin.y, rmax.x, rmax.y, rsize.x, rsize.y)
        ImGui.BulletText(
            "with Hovering Delay or Stationary test:\nIsItemHovered() = %d\nIsItemHovered(_Stationary) = %d\nIsItemHovered(_DelayShort) = %d\nIsItemHovered(_DelayNormal) = %d\nIsItemHovered(_Tooltip) = %d",
            B(hovered_delay_none), B(hovered_delay_stationary), B(hovered_delay_short), B(hovered_delay_normal), B(hovered_delay_tooltip))

        if s.liveedit_override then ImGui.PopItemFlag(); ImGui.PopItemFlag() end
        if s.item_mixedvalue then ImGui.PopItemFlag() end
        if s.item_disabled then ImGui.EndDisabled() end

        ImGui.InputText("unused", s.unused, 1, ImGuiInputTextFlags.ReadOnly)
        ImGui.SameLine()
        HelpMarker("This widget is only here to be able to tab-out of the widgets above and see e.g. Deactivated() status.")
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Querying Window Status (Focused/Hovered etc.)") then
        _, s.embed = ImGui.Checkbox("Embed everything inside a child window for testing _RootWindow flag.", s.embed)
        if s.embed then ImGui.BeginChild("outer_child", ImVec2(0, ImGui.GetFontSize() * 20.0), ImGuiChildFlags.Borders) end
        local FF, HF = ImGuiFocusedFlags, ImGuiHoveredFlags
        local bor = bit32.bor
        -- Testing IsWindowFocused() function with its various flags.
        ImGui.BulletText(
            "IsWindowFocused() = %d\nIsWindowFocused(_ChildWindows) = %d\nIsWindowFocused(_ChildWindows|_NoPopupHierarchy) = %d\n" ..
            "IsWindowFocused(_ChildWindows|_DockHierarchy) = %d\nIsWindowFocused(_ChildWindows|_RootWindow) = %d\n" ..
            "IsWindowFocused(_ChildWindows|_RootWindow|_NoPopupHierarchy) = %d\nIsWindowFocused(_ChildWindows|_RootWindow|_DockHierarchy) = %d\n" ..
            "IsWindowFocused(_RootWindow) = %d\nIsWindowFocused(_RootWindow|_NoPopupHierarchy) = %d\nIsWindowFocused(_RootWindow|_DockHierarchy) = %d\n" ..
            "IsWindowFocused(_AnyWindow) = %d\n",
            B(ImGui.IsWindowFocused()), B(ImGui.IsWindowFocused(FF.ChildWindows)), B(ImGui.IsWindowFocused(bor(FF.ChildWindows, FF.NoPopupHierarchy))),
            B(ImGui.IsWindowFocused(bor(FF.ChildWindows, FF.DockHierarchy))), B(ImGui.IsWindowFocused(bor(FF.ChildWindows, FF.RootWindow))),
            B(ImGui.IsWindowFocused(bor(FF.ChildWindows, FF.RootWindow, FF.NoPopupHierarchy))), B(ImGui.IsWindowFocused(bor(FF.ChildWindows, FF.RootWindow, FF.DockHierarchy))),
            B(ImGui.IsWindowFocused(FF.RootWindow)), B(ImGui.IsWindowFocused(bor(FF.RootWindow, FF.NoPopupHierarchy))), B(ImGui.IsWindowFocused(bor(FF.RootWindow, FF.DockHierarchy))),
            B(ImGui.IsWindowFocused(FF.AnyWindow)))

        -- Testing IsWindowHovered() function with its various flags.
        ImGui.BulletText(
            "IsWindowHovered() = %d\nIsWindowHovered(_AllowWhenBlockedByPopup) = %d\nIsWindowHovered(_AllowWhenBlockedByActiveItem) = %d\n" ..
            "IsWindowHovered(_ChildWindows) = %d\nIsWindowHovered(_ChildWindows|_NoPopupHierarchy) = %d\nIsWindowHovered(_ChildWindows|_DockHierarchy) = %d\n" ..
            "IsWindowHovered(_ChildWindows|_RootWindow) = %d\nIsWindowHovered(_ChildWindows|_RootWindow|_NoPopupHierarchy) = %d\n" ..
            "IsWindowHovered(_ChildWindows|_RootWindow|_DockHierarchy) = %d\nIsWindowHovered(_RootWindow) = %d\nIsWindowHovered(_RootWindow|_NoPopupHierarchy) = %d\n" ..
            "IsWindowHovered(_RootWindow|_DockHierarchy) = %d\nIsWindowHovered(_ChildWindows|_AllowWhenBlockedByPopup) = %d\nIsWindowHovered(_AnyWindow) = %d\n" ..
            "IsWindowHovered(_Stationary) = %d\n",
            B(ImGui.IsWindowHovered()), B(ImGui.IsWindowHovered(HF.AllowWhenBlockedByPopup)), B(ImGui.IsWindowHovered(HF.AllowWhenBlockedByActiveItem)),
            B(ImGui.IsWindowHovered(HF.ChildWindows)), B(ImGui.IsWindowHovered(bor(HF.ChildWindows, HF.NoPopupHierarchy))), B(ImGui.IsWindowHovered(bor(HF.ChildWindows, HF.DockHierarchy))),
            B(ImGui.IsWindowHovered(bor(HF.ChildWindows, HF.RootWindow))), B(ImGui.IsWindowHovered(bor(HF.ChildWindows, HF.RootWindow, HF.NoPopupHierarchy))),
            B(ImGui.IsWindowHovered(bor(HF.ChildWindows, HF.RootWindow, HF.DockHierarchy))), B(ImGui.IsWindowHovered(HF.RootWindow)), B(ImGui.IsWindowHovered(bor(HF.RootWindow, HF.NoPopupHierarchy))),
            B(ImGui.IsWindowHovered(bor(HF.RootWindow, HF.DockHierarchy))), B(ImGui.IsWindowHovered(bor(HF.ChildWindows, HF.AllowWhenBlockedByPopup))), B(ImGui.IsWindowHovered(HF.AnyWindow)),
            B(ImGui.IsWindowHovered(HF.Stationary)))
        ImGui.BeginChild("child", ImVec2(0, 50), ImGuiChildFlags.Borders)
        ImGui.Text("This is another child window for testing the _ChildWindows flag.")
        ImGui.EndChild()
        if s.embed then ImGui.EndChild() end

        -- Calling IsItemHovered() after begin returns the hovered status of the title bar.
        -- This is useful in particular if you want to create a context menu associated to the title bar of a window.
        -- This will also work when docked into a Tab (the Tab replace the Title Bar and guarantee the same properties).
        _, s.test_window = ImGui.Checkbox("Hovered/Active tests after Begin() for title bar testing", s.test_window)
        if s.test_window then
            -- FIXME-DOCK: This window cannot be docked within the ImGui Demo window, this will cause a feedback loop and get them stuck.
            -- Could we fix this through an ImGuiWindowClass feature? Or an API call to tag our parent as "don't skip items"?
            s.test_window = ImGui.Begin("Title bar Hovered/Active tests", s.test_window)
            if ImGui.BeginPopupContextItem() then -- <-- This is using IsItemHovered()
                if ImGui.MenuItem("Close") then s.test_window = false end
                ImGui.EndPopup()
            end
            ImGui.Text("IsItemHovered() after begin = %d (== is title bar hovered)\nIsItemActive() after begin = %d (== is window being clicked/moved)\n",
                B(ImGui.IsItemHovered()), B(ImGui.IsItemActive()))
            ImGui.End()
        end
        ImGui.TreePop()
    end
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsSelectables()
-------------------------------------------------------------------------------

S.sel = { basic = { false, true, false, false }, multi = { false, false, false }, checked = { false, false, false, false, false }, selected_n = 0,
    tables = {}, grid = { { 1, 0, 0, 0 }, { 0, 1, 0, 0 }, { 0, 0, 1, 0 }, { 0, 0, 0, 1 } },
    align = { true, false, true, false, true, false, true, false, true } }
for i = 1, 10 do S.sel.tables[i] = false end
function DemoWindowWidgetsSelectables()
    -- ImGui.SetNextItemOpen(true, ImGuiCond.Once)
    if not ImGui.TreeNode("Selectables") then return end
    local s = S.sel
    -- Selectable() has 2 overloads:
    -- - The one taking "bool selected" as a read-only selection information.
    --   When Selectable() has been clicked it returns true and you can alter selection state accordingly.
    -- - The one taking "bool* p_selected" as a read-write selection information (convenient in some cases)
    --   (in this port: the SelectableP() helper above, which returns (pressed, selected))
    -- The earlier is more flexible, as in real application your selection may be stored in many different ways
    -- and not necessarily inside a bool value (e.g. in flags within objects, as an external list, etc).
    if ImGui.TreeNode("Basic") then
        local b = s.basic
        _, b[1] = SelectableP("1. I am selectable", b[1])
        _, b[2] = SelectableP("2. I am selectable", b[2])
        _, b[3] = SelectableP("3. I am selectable", b[3])
        if ImGui.Selectable("4. I am double clickable", b[4], ImGuiSelectableFlags.AllowDoubleClick) then
            if ImGui.IsMouseDoubleClicked(0) then b[4] = not b[4] end
        end
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Multiple items on the same line") then
        -- - Using SetNextItemAllowOverlap()
        -- - Using the Selectable() override that takes "bool* p_selected" parameter, the bool value is toggled automatically.
        local m = s.multi
        ImGui.SetNextItemAllowOverlap(); _, m[1] = SelectableP("main.c", m[1]); ImGui.SameLine(); ImGui.SmallButton("Link 1")
        ImGui.SetNextItemAllowOverlap(); _, m[2] = SelectableP("hello.cpp", m[2]); ImGui.SameLine(); ImGui.SmallButton("Link 2")
        ImGui.SetNextItemAllowOverlap(); _, m[3] = SelectableP("hello.h", m[3]); ImGui.SameLine(); ImGui.SmallButton("Link 3")

        -- (2)
        -- - Using ImGuiSelectableFlags.AllowOverlap is a shortcut for calling SetNextItemAllowOverlap()
        -- - No visible label, display contents inside the selectable bounds.
        -- - We don't maintain actual selection in this example to keep things simple.
        ImGui.Spacing()
        local color_marker_w = ImGui.CalcTextSize("x").x
        for n = 0, 4 do
            ImGui.PushID(n)
            ImGui.AlignTextToFramePadding()
            if ImGui.Selectable("##selectable", s.selected_n == n, ImGuiSelectableFlags.AllowOverlap) then s.selected_n = n end
            ImGui.SameLine(0, 0)
            _, s.checked[n + 1] = ImGui.Checkbox("##check", s.checked[n + 1])
            ImGui.SameLine()
            local color = ImVec4((n % 2 == 1) and 1.0 or 0.2, (math.floor(n / 2) % 2 == 1) and 1.0 or 0.2, 0.2, 1.0)
            ImGui.ColorButton("##color", color, ImGuiColorEditFlags.NoTooltip, ImVec2(color_marker_w, 0))
            ImGui.SameLine()
            ImGui.Text("Some label")
            ImGui.PopID()
        end
        ImGui.TreePop()
    end

    if ImGui.TreeNode("In Tables") then
        local sel = s.tables
        local TF = ImGuiTableFlags
        if ImGui.BeginTable("split1", 3, bit32.bor(TF.Resizable, TF.NoSavedSettings, TF.Borders)) then
            for i = 0, 9 do
                ImGui.TableNextColumn()
                _, sel[i + 1] = SelectableP(string.format("Item %d", i), sel[i + 1]) -- FIXME-TABLE: Selection overlap
            end
            ImGui.EndTable()
        end
        ImGui.Spacing()
        if ImGui.BeginTable("split2", 3, bit32.bor(TF.Resizable, TF.NoSavedSettings, TF.Borders)) then
            for i = 0, 9 do
                ImGui.TableNextRow()
                ImGui.TableNextColumn()
                _, sel[i + 1] = SelectableP(string.format("Item %d", i), sel[i + 1], ImGuiSelectableFlags.SpanAllColumns)
                ImGui.TableNextColumn()
                ImGui.Text("Some other contents")
                ImGui.TableNextColumn()
                ImGui.Text("123456")
            end
            ImGui.EndTable()
        end
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Grid") then
        local g = s.grid

        -- Add in a bit of silly fun...
        local time = ImGui.GetTime()
        local winning_state = true
        for y = 1, 4 do for x = 1, 4 do if g[y][x] == 0 then winning_state = false end end end -- If all cells are selected...
        if winning_state then
            ImGui.PushStyleVar(ImGuiStyleVar.SelectableTextAlign, ImVec2(0.5 + 0.5 * math.cos(time * 2.0), 0.5 + 0.5 * math.sin(time * 3.0)))
        end
        local size = ImGui.CalcTextSize("Sailor").x
        for y = 1, 4 do
            for x = 1, 4 do
                if x > 1 then ImGui.SameLine() end
                ImGui.PushID((y - 1) * 4 + (x - 1))
                if ImGui.Selectable("Sailor", g[y][x] ~= 0, 0, ImVec2(size, size)) then
                    -- Toggle clicked cell + toggle neighbors
                    g[y][x] = 1 - g[y][x]
                    if x > 1 then g[y][x - 1] = 1 - g[y][x - 1] end
                    if x < 4 then g[y][x + 1] = 1 - g[y][x + 1] end
                    if y > 1 then g[y - 1][x] = 1 - g[y - 1][x] end
                    if y < 4 then g[y + 1][x] = 1 - g[y + 1][x] end
                end
                ImGui.PopID()
            end
        end
        if winning_state then ImGui.PopStyleVar() end
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Alignment") then
        HelpMarker("By default, Selectables uses style.SelectableTextAlign but it can be overridden on a per-item basis using PushStyleVar(). You'll probably want to always keep your default situation to left-align otherwise it becomes difficult to layout multiple items on a same line")
        local size = ImGui.CalcTextSize("(1.0,1.0)").x
        for y = 0, 2 do
            for x = 0, 2 do
                local alignment = ImVec2(x / 2.0, y / 2.0)
                local name = string.format("(%.1f,%.1f)", alignment.x, alignment.y)
                if x > 0 then ImGui.SameLine() end
                ImGui.PushStyleVar(ImGuiStyleVar.SelectableTextAlign, alignment)
                _, s.align[3 * y + x + 1] = SelectableP(name, s.align[3 * y + x + 1], ImGuiSelectableFlags.None, ImVec2(size, size))
                ImGui.PopStyleVar()
            end
        end
        ImGui.TreePop()
    end
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsTabs()
-------------------------------------------------------------------------------

local function EditTabBarFittingPolicyFlags(flags)
    local TB = ImGuiTabBarFlags
    if bit32.band(flags, TB.FittingPolicyMask_) == 0 then flags = bit32.bor(flags, TB.FittingPolicyDefault_) end
    for _, n in ipairs({ "FittingPolicyMixed", "FittingPolicyShrink", "FittingPolicyScroll" }) do
        local p
        p, flags = ImGui.CheckboxFlags("ImGuiTabBarFlags_" .. n, flags, TB[n])
        if p then flags = bit32.band(flags, bit32.bnot(bit32.bxor(TB.FittingPolicyMask_, TB[n]))) end
    end
    return flags
end

S.tabs = { adv_flags = ImGuiTabBarFlags.Reorderable, opened = { true, true, true, true }, active_tabs = {}, next_tab_id = 0,
    show_leading = true, show_trailing = true, show_lt_tabs = false,
    tib_flags = bit32.bor(ImGuiTabBarFlags.AutoSelectNewTabs, ImGuiTabBarFlags.Reorderable, ImGuiTabBarFlags.FittingPolicyMixed) }
function DemoWindowWidgetsTabs()
    if not ImGui.TreeNode("Tabs") then return end
    local s = S.tabs
    local TB, TI = ImGuiTabBarFlags, ImGuiTabItemFlags
    if ImGui.TreeNode("Basic") then
        if ImGui.BeginTabBar("MyTabBar", TB.None) then
            if ImGui.BeginTabItem("Avocado") then ImGui.Text("This is the Avocado tab!\nblah blah blah blah blah"); ImGui.EndTabItem() end
            if ImGui.BeginTabItem("Broccoli") then ImGui.Text("This is the Broccoli tab!\nblah blah blah blah blah"); ImGui.EndTabItem() end
            if ImGui.BeginTabItem("Cucumber") then ImGui.Text("This is the Cucumber tab!\nblah blah blah blah blah"); ImGui.EndTabItem() end
            ImGui.EndTabBar()
        end
        ImGui.Separator()
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Advanced & Close Button") then
        -- Expose a couple of the available flags. In most cases you may just call BeginTabBar() with no flags (0).
        for _, n in ipairs({ "Reorderable", "AutoSelectNewTabs", "TabListPopupButton", "NoCloseWithMiddleMouseButton", "DrawSelectedOverline" }) do
            _, s.adv_flags = ImGui.CheckboxFlags("ImGuiTabBarFlags_" .. n, s.adv_flags, TB[n])
        end
        s.adv_flags = EditTabBarFittingPolicyFlags(s.adv_flags)

        -- Tab Bar
        ImGui.AlignTextToFramePadding()
        ImGui.Text("Opened:")
        local names = { "Artichoke", "Beetroot", "Celery", "Daikon" }
        for n = 1, 4 do -- s.opened: Persistent user state
            ImGui.SameLine()
            _, s.opened[n] = ImGui.Checkbox(names[n], s.opened[n])
        end

        -- Passing an open flag to BeginTabItem() is similar to passing one to Begin():
        -- the returned open value will be false when the tab is closed.
        if ImGui.BeginTabBar("MyTabBar", s.adv_flags) then
            for n = 1, 4 do
                if s.opened[n] then
                    local visible
                    visible, s.opened[n] = ImGui.BeginTabItem(names[n], s.opened[n], TI.None)
                    if visible then
                        ImGui.Text("This is the %s tab!", names[n])
                        if (n - 1) % 2 == 1 then ImGui.Text("I am an odd tab.") end
                        ImGui.EndTabItem()
                    end
                end
            end
            ImGui.EndTabBar()
        end
        ImGui.Separator()
        ImGui.TreePop()
    end

    if ImGui.TreeNode("TabItemButton & Leading/Trailing flags") then
        if s.next_tab_id == 0 then -- Initialize with some default tabs
            for _ = 1, 3 do s.active_tabs[#s.active_tabs + 1] = s.next_tab_id; s.next_tab_id = s.next_tab_id + 1 end
        end

        -- TabItemButton() and Leading/Trailing flags are distinct features which we will demo together.
        -- (It is possible to submit regular tabs with Leading/Trailing flags, or TabItemButton tabs without Leading/Trailing flags...
        -- but they tend to make more sense together)
        _, s.show_leading = ImGui.Checkbox("Show Leading TabItemButton()", s.show_leading)
        _, s.show_trailing = ImGui.Checkbox("Show Trailing TabItemButton()", s.show_trailing)
        _, s.show_lt_tabs = ImGui.Checkbox("Show Leading+Trailing TabItem()", s.show_lt_tabs)

        -- Expose some other flags which are useful to showcase how they interact with Leading/Trailing tabs
        s.tib_flags = EditTabBarFittingPolicyFlags(s.tib_flags)

        if ImGui.BeginTabBar("MyTabBar", s.tib_flags) then
            -- Demo a Leading TabItemButton(): click the "?" button to open a menu
            if s.show_leading then
                if ImGui.TabItemButton("?", bit32.bor(TI.Leading, TI.NoTooltip)) then ImGui.OpenPopup("MyHelpMenu") end
            end
            if ImGui.BeginPopup("MyHelpMenu") then
                ImGui.Selectable("Hello!")
                ImGui.EndPopup()
            end

            -- Demo Leading/Trailing Tabs
            if s.show_lt_tabs then
                if ImGui.BeginTabItem("Leading", nil, TI.Leading) then ImGui.EndTabItem() end
                if ImGui.BeginTabItem("Trailing", nil, TI.Trailing) then ImGui.EndTabItem() end
            end

            -- Demo Trailing Tabs: click the "+" button to add a new tab.
            -- (In your app you may want to use a font icon instead of the "+")
            -- We submit it before the regular tabs, but thanks to the ImGuiTabItemFlags.Trailing flag it will always appear at the end.
            if s.show_trailing then
                if ImGui.TabItemButton("+", bit32.bor(TI.Trailing, TI.NoTooltip)) then
                    s.active_tabs[#s.active_tabs + 1] = s.next_tab_id; s.next_tab_id = s.next_tab_id + 1 -- Add new tab
                end
            end

            -- Submit our regular tabs
            local n = 1
            while n <= #s.active_tabs do
                local name = string.format("%04d", s.active_tabs[n])
                local visible, open = ImGui.BeginTabItem(name, true, TI.None)
                if visible then
                    ImGui.Text("This is the %s tab!", name)
                    ImGui.EndTabItem()
                end
                if open == false then table.remove(s.active_tabs, n) else n = n + 1 end
            end
            ImGui.EndTabBar()
        end
        ImGui.Separator()
        ImGui.TreePop()
    end
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsText()
-------------------------------------------------------------------------------

S.text = { custom_size = 16.0, custom_scale = 1.0, wrap_width = 200.0, utf8 = Buf("\xe6\x97\xa5\xe6\x9c\xac\xe8\xaa\x9e", 32) }
function DemoWindowWidgetsText()
    if not ImGui.TreeNode("Text") then return end
    local s = S.text
    if ImGui.TreeNode("Colorful Text") then
        -- Using shortcut. You can use PushStyleColor()/PopStyleColor() for more flexibility.
        ImGui.TextColored(ImVec4(1.0, 0.0, 1.0, 1.0), "Pink")
        ImGui.TextColored(ImVec4(1.0, 1.0, 0.0, 1.0), "Yellow")
        ImGui.TextDisabled("Disabled")
        ImGui.SameLine(); HelpMarker("The TextDisabled color is stored in ImGuiStyle.")
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Font Size") then
        local style = ImGui.GetStyle()
        local global_scale = style.FontScaleMain * style.FontScaleDpi
        ImGui.Text("style.FontScaleMain = %0.2f", style.FontScaleMain)
        ImGui.Text("style.FontScaleDpi = %0.2f", style.FontScaleDpi)
        ImGui.Text("global_scale = ~%0.2f", global_scale) -- This is not technically accurate as internal scales may apply, but conceptually let's pretend it is.
        ImGui.Text("FontSize = %0.2f", ImGui.GetFontSize())

        ImGui.SeparatorText("")
        s.custom_size = ImGui.SliderFloat("custom_size", s.custom_size, 10.0, 100.0, "%.0f")
        ImGui.Text("ImGui::PushFont(nullptr, custom_size);")
        ImGui.PushFont(nil, s.custom_size)
        ImGui.Text("FontSize = %.2f (== %.2f * global_scale)", ImGui.GetFontSize(), s.custom_size)
        ImGui.PopFont()
        ImGui.SeparatorText("")
        s.custom_scale = ImGui.SliderFloat("custom_scale", s.custom_scale, 0.5, 4.0, "%.2f")
        ImGui.Text("ImGui::PushFont(nullptr, style.FontSizeBase * custom_scale);")
        ImGui.PushFont(nil, style.FontSizeBase * s.custom_scale)
        ImGui.Text("FontSize = %.2f (== style.FontSizeBase * %.2f * global_scale)", ImGui.GetFontSize(), s.custom_scale)
        ImGui.PopFont()
        ImGui.SeparatorText("")
        local scaling = 0.5
        while scaling <= 4.0 do
            ImGui.PushFont(nil, style.FontSizeBase * scaling)
            ImGui.Text("FontSize = %.2f (== style.FontSizeBase * %.2f * global_scale)", ImGui.GetFontSize(), scaling)
            ImGui.PopFont()
            scaling = scaling + 0.5
        end
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Word Wrapping") then
        -- Using shortcut. You can use PushTextWrapPos()/PopTextWrapPos() for more flexibility.
        ImGui.TextWrapped("This text should automatically wrap on the edge of the window. The current implementation for text wrapping follows simple rules suitable for English and possibly other languages.")
        ImGui.Spacing()
        s.wrap_width = ImGui.SliderFloat("Wrap width", s.wrap_width, -20, 600, "%.0f")
        local draw_list = ImGui.GetWindowDrawList()
        for n = 0, 1 do
            ImGui.Text("Test paragraph %d:", n)
            local pos = ImGui.GetCursorScreenPos()
            local marker_min = ImVec2(pos.x + s.wrap_width, pos.y)
            local marker_max = ImVec2(pos.x + s.wrap_width + 10, pos.y + ImGui.GetTextLineHeight())
            ImGui.PushTextWrapPos(ImGui.GetCursorPos().x + s.wrap_width)
            if n == 0 then
                ImGui.Text("The lazy dog is a good dog. This paragraph should fit within %.0f pixels. Testing a 1 character word. The quick brown fox jumps over the lazy dog.", s.wrap_width)
            else
                ImGui.Text("aaaaaaaa bbbbbbbb, c cccccccc,dddddddd. d eeeeeeee   ffffffff. gggggggg!hhhhhhhh")
            end

            -- Draw actual text bounding box, following by marker of our expected limit (should not overlap!)
            draw_list:AddRect(ImGui.GetItemRectMin(), ImGui.GetItemRectMax(), IM_COL32(255, 255, 0, 255))
            draw_list:AddRectFilled(marker_min, marker_max, IM_COL32(255, 0, 255, 255))
            ImGui.PopTextWrapPos()
        end
        ImGui.TreePop()
    end

    if ImGui.TreeNode("UTF-8 Text") then
        -- UTF-8 test with Japanese characters
        -- (Needs a suitable font? Try "Google Noto" or "Arial Unicode". See docs/FONTS.md for details.)
        -- - FOR THIS DEMO FILE ONLY, WE ARE *NOT* INCLUDING RAW UTF-8
        --   CHARACTERS IN THIS SOURCE FILE. Instead we are encoding a few strings with hexadecimal escapes.
        -- Note that characters values are preserved even by InputText() if the font cannot be displayed,
        -- so you can safely copy & paste garbled characters into another application.
        ImGui.TextWrapped("CJK text will only appear if the font was loaded with the appropriate CJK character ranges. Call io.Fonts->AddFontFromFileTTF() manually to load extra character ranges. Read docs/FONTS.md for details.")
        ImGui.Text("Hiragana: \xe3\x81\x8b\xe3\x81\x8d\xe3\x81\x8f\xe3\x81\x91\xe3\x81\x93 (kakikukeko)")
        ImGui.Text("Kanjis: \xe6\x97\xa5\xe6\x9c\xac\xe8\xaa\x9e (nihongo)")
        ImGui.InputText("UTF-8 input", s.utf8, 32)
        ImGui.TreePop()
    end
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsTextFilter()
-------------------------------------------------------------------------------

S.tf = { filter = nil }
function DemoWindowWidgetsTextFilter()
    if not ImGui.TreeNode("Text Filter") then return end
    -- Helper class to easy setup a text filter.
    -- You may want to implement a more feature-full filtering scheme in your own application.
    S.tf.filter = S.tf.filter or ImGuiTextFilter()
    local filter = S.tf.filter
    HelpMarker("Not a widget per-se, but ImGuiTextFilter is a helper to perform simple filtering on text strings.")
    ImGui.Text("Filter usage:\n  \"\"         display all lines\n  xxx        display lines containing \"xxx\"\n  xxx yyy    display lines containing \"xxx\" and \"yyy\"\n  \"xxx yyy\"  display lines containing \"xxx yyy\"\n  xxx,yyy    display lines containing \"xxx\" or \"yyy\"\n  -xxx       hide lines containing \"xxx\"")
    ImGui.SetNextItemWidth(-FLT_MIN)
    filter:DrawWithHint("##Filter", "Filter (incl -excl)")
    if ImGui.BeginChild("##items", ImVec2(-FLT_MIN, ImGui.GetTextLineHeightWithSpacing() * 15), ImGuiChildFlags.FrameStyle) then
        for _, item in ipairs({ "aaa1.c", "bbb1.c", "ccc1.c", "aaa2.cpp", "bbb2.cpp", "ccc2.cpp", "abc.h", "hello, world" }) do
            if filter:PassFilter(item) then ImGui.TextUnformatted(item) end
        end
        for _, item in ipairs(ExampleNames) do
            if filter:PassFilter(item) then ImGui.TextUnformatted(item) end
        end
    end
    ImGui.EndChild()
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsTextInput()
-------------------------------------------------------------------------------

S.ti = {
    text = Buf("/*\n The Pentium F00F bug, shorthand for F0 0F C7 C8,\n the hexadecimal encoding of one offending instruction,\n more formally, the invalid operand with locked CMPXCHG8B\n instruction bug, is a design flaw in the majority of\n Intel Pentium, Pentium MMX, and Pentium OverDrive\n processors (all in the P5 microarchitecture).\n*/\n\nlabel:\n\tlock cmpxchg8b eax\n", 1024 * 16),
    ml_flags = ImGuiInputTextFlags.AllowTabInput,
    f = { Buf("", 32), Buf("", 32), Buf("", 32), Buf("", 32), Buf("", 32), Buf("", 32), Buf("", 32) },
    password = Buf("password123", 64), cb1 = Buf("", 64), cb2 = Buf("", 64), cb3 = Buf("", 64), edit_count = { 0 },
    rs_flags = 0, rs = Buf("", 1024),
    elide = Buf("/path/to/some/folder/with/long/filename.cpp", 128), elide_flags = ImGuiInputTextFlags.ElideLeft,
    misc = Buf("", 16), misc_flags = ImGuiInputTextFlags.EscapeClearsAll }
function DemoWindowWidgetsTextInput()
    if not ImGui.TreeNode("Text Input") then return end
    local s = S.ti
    local IT = ImGuiInputTextFlags
    local function FlagBox(key, name)
        if IT[name] then _, s[key] = ImGui.CheckboxFlags("ImGuiInputTextFlags_" .. name, s[key], IT[name]) end
    end
    if ImGui.TreeNode("Multi-line Text Input") then
        -- WE ARE USING A FIXED-SIZE BUFFER FOR SIMPLICITY HERE.
        HelpMarker("You can use the ImGuiInputTextFlags_CallbackResize facility if you need to wire InputTextMultiline() to a dynamic string type.")
        FlagBox("ml_flags", "ReadOnly")
        FlagBox("ml_flags", "WordWrap")
        ImGui.SameLine(); HelpMarker("Feature is currently in Beta. Please read comments in imgui.h")
        FlagBox("ml_flags", "AllowTabInput")
        ImGui.SameLine(); HelpMarker("When _AllowTabInput is set, passing through the widget with Tabbing doesn't automatically activate it, in order to also cycling through subsequent widgets.")
        FlagBox("ml_flags", "CtrlEnterForNewLine")
        ImGui.InputTextMultiline("##source", s.text, 1024 * 16, ImVec2(-FLT_MIN, ImGui.GetTextLineHeight() * 16), s.ml_flags)
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Filtered Text Input") then
        local a, z, A, Z = string.byte("a"), string.byte("z"), string.byte("A"), string.byte("Z")
        -- Modify character input by altering 'data.EventChar' (ImGuiInputTextFlags.CallbackCharFilter callback)
        local function FilterCasingSwap(data)
            local c = data.EventChar
            if c >= a and c <= z then data.EventChar = c - (a - A) -- Lowercase becomes uppercase
            elseif c >= A and c <= Z then data.EventChar = c + (a - A) end -- Uppercase becomes lowercase
            return 0
        end
        -- Return 0 (pass) if the character is 'i' or 'm' or 'g' or 'u' or 'i', otherwise return 1 (filter out)
        local function FilterImGuiLetters(data)
            local c = data.EventChar
            if c < 256 and string.find("imgui", string.char(c), 1, true) then return 0 end
            return 1
        end
        local f = s.f
        ImGui.InputText("default", f[1], 32)
        ImGui.InputText("decimal", f[2], 32, IT.CharsDecimal)
        ImGui.InputText("hexadecimal", f[3], 32, bit32.bor(IT.CharsHexadecimal, IT.CharsUppercase))
        ImGui.InputText("uppercase", f[4], 32, IT.CharsUppercase)
        ImGui.InputText("no blank", f[5], 32, IT.CharsNoBlank)
        ImGui.InputText("casing swap", f[6], 32, IT.CallbackCharFilter, FilterCasingSwap) -- Use CharFilter callback to replace characters.
        ImGui.InputText("\"imgui\"", f[7], 32, IT.CallbackCharFilter, FilterImGuiLetters) -- Use CharFilter callback to disable some characters.
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Password Input") then
        ImGui.InputText("password", s.password, 64, IT.Password)
        ImGui.SameLine(); HelpMarker("Display all characters as '*'.\nDisable clipboard cut and copy.\nDisable logging.\n")
        ImGui.InputTextWithHint("password (w/ hint)", "<password>", s.password, 64, IT.Password)
        ImGui.InputText("password (clear)", s.password, 64)
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Completion, History, Edit Callbacks") then
        local function MyCallback(data)
            if data.EventFlag == IT.CallbackCompletion then
                data:InsertChars(data.CursorPos, "..")
            elseif data.EventFlag == IT.CallbackHistory then
                if data.EventKey == ImGuiKey.UpArrow then
                    data:DeleteChars(0, data.BufTextLen)
                    data:InsertChars(0, "Pressed Up!")
                    data:SelectAll()
                elseif data.EventKey == ImGuiKey.DownArrow then
                    data:DeleteChars(0, data.BufTextLen)
                    data:InsertChars(0, "Pressed Down!")
                    data:SelectAll()
                end
            elseif data.EventFlag == IT.CallbackEdit then
                -- Toggle casing of first character
                local c = data.Buf[1]
                if (c >= 97 and c <= 122) or (c >= 65 and c <= 90) then data.Buf[1] = bit32.bxor(c, 32) end
                data.BufDirty = true

                -- Increment a counter
                local p_int = data.UserData
                p_int[1] = p_int[1] + 1
            end
            return 0
        end
        ImGui.InputText("Completion", s.cb1, 64, IT.CallbackCompletion, MyCallback)
        ImGui.SameLine(); HelpMarker("Here we append \"..\" each time Tab is pressed. See 'Examples>Console' for a more meaningful demonstration of using this callback.")
        ImGui.InputText("History", s.cb2, 64, IT.CallbackHistory, MyCallback)
        ImGui.SameLine(); HelpMarker("Here we replace and select text each time Up/Down are pressed. See 'Examples>Console' for a more meaningful demonstration of using this callback.")
        ImGui.InputText("Edit", s.cb3, 64, IT.CallbackEdit, MyCallback, s.edit_count)
        ImGui.SameLine(); HelpMarker("Here we toggle the casing of the first character on every edit + count edits.")
        ImGui.SameLine(); ImGui.Text("(%d)", s.edit_count[1])
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Resize Callback") then
        HelpMarker("Using ImGuiInputTextFlags_CallbackResize to wire your custom string type to InputText().\n\n(Lua port: fixed 1024 byte buffer, CallbackResize growth not supported)")
        FlagBox("rs_flags", "WordWrap")
        ImGui.InputTextMultiline("##MyStr", s.rs, 1024, ImVec2(-FLT_MIN, ImGui.GetTextLineHeight() * 16), s.rs_flags)
        ImGui.Text("Size: %d\nCapacity: %d", #BufStr(s.rs) + 1, 1024)
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Eliding, Alignment") then
        FlagBox("elide_flags", "ElideLeft")
        ImGui.InputText("Path", s.elide, 128, s.elide_flags)
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Miscellaneous") then
        FlagBox("misc_flags", "EscapeClearsAll")
        FlagBox("misc_flags", "ReadOnly")
        FlagBox("misc_flags", "NoUndoRedo")
        ImGui.InputText("Hello", s.misc, 16, s.misc_flags)
        ImGui.TreePop()
    end
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsTooltips()
-------------------------------------------------------------------------------

S.tt = { arr = { 0.6, 0.1, 1.0, 0.5, 0.92, 0.1, 0.2 }, always_on = 0 }
function DemoWindowWidgetsTooltips()
    if not ImGui.TreeNode("Tooltips") then return end
    local s = S.tt
    local HF = ImGuiHoveredFlags
    -- Tooltips are windows following the mouse. They do not take focus away.
    ImGui.SeparatorText("General")

    -- Typical use cases:
    -- - Short-form (text only):      SetItemTooltip("Hello")
    -- - Short-form (any contents):   if BeginItemTooltip() then Text("Hello"); EndTooltip() end

    -- - Full-form (text only):       if IsItemHovered(...) then SetTooltip("Hello") end
    -- - Full-form (any contents):    if IsItemHovered(...) and BeginTooltip() then Text("Hello"); EndTooltip() end

    HelpMarker("Tooltip are typically created by using a IsItemHovered() + SetTooltip() sequence.\n\nWe provide a helper SetItemTooltip() function to perform the two with standards flags.")
    local sz = ImVec2(-FLT_MIN, 0.0)
    ImGui.Button("Basic", sz)
    ImGui.SetItemTooltip("I am a tooltip")
    ImGui.Button("Fancy", sz)
    if ImGui.BeginItemTooltip() then
        ImGui.Text("I am a fancy tooltip")
        ImGui.PlotLines("Curve", s.arr, nil, #s.arr)
        ImGui.Text("Sin(time) = %f", math.sin(ImGui.GetTime()))
        ImGui.EndTooltip()
    end

    ImGui.SeparatorText("Always On")

    -- Showcase NOT relying on a IsItemHovered() to emit a tooltip.
    -- Here the tooltip is always emitted when 'always_on == true'.
    _, s.always_on = ImGui.RadioButton("Off", s.always_on, 0)
    ImGui.SameLine()
    _, s.always_on = ImGui.RadioButton("Always On (Simple)", s.always_on, 1)
    ImGui.SameLine()
    _, s.always_on = ImGui.RadioButton("Always On (Advanced)", s.always_on, 2)
    if s.always_on == 1 then
        ImGui.SetTooltip("I am following you around.")
    elseif s.always_on == 2 and ImGui.BeginTooltip() then
        ImGui.ProgressBar(math.sin(ImGui.GetTime()) * 0.5 + 0.5, ImVec2(ImGui.GetFontSize() * 25, 0.0))
        ImGui.EndTooltip()
    end

    ImGui.SeparatorText("Custom")
    HelpMarker("Passing ImGuiHoveredFlags_ForTooltip to IsItemHovered() is the preferred way to standardize tooltip activation details across your application. You may however decide to use custom flags for a specific tooltip instance.")

    -- The following examples are passed for documentation purpose but may not be useful to most users.
    -- Passing ImGuiHoveredFlags.ForTooltip to IsItemHovered() will pull ImGuiHoveredFlags flags values from
    -- 'style.HoverFlagsForTooltipMouse' or 'style.HoverFlagsForTooltipNav' depending on whether mouse or keyboard/gamepad is being used.
    -- With default settings, ImGuiHoveredFlags.ForTooltip is equivalent to ImGuiHoveredFlags.DelayShort + ImGuiHoveredFlags.Stationary.
    ImGui.Button("Manual", sz)
    if ImGui.IsItemHovered(HF.ForTooltip) then ImGui.SetTooltip("I am a manually emitted tooltip.") end
    ImGui.Button("DelayNone", sz)
    if ImGui.IsItemHovered(HF.DelayNone) then ImGui.SetTooltip("I am a tooltip with no delay.") end
    ImGui.Button("DelayShort", sz)
    if ImGui.IsItemHovered(bit32.bor(HF.DelayShort, HF.NoSharedDelay)) then ImGui.SetTooltip("I am a tooltip with a short delay (%0.2f sec).", ImGui.GetStyle().HoverDelayShort) end
    ImGui.Button("DelayLong", sz)
    if ImGui.IsItemHovered(bit32.bor(HF.DelayNormal, HF.NoSharedDelay)) then ImGui.SetTooltip("I am a tooltip with a long delay (%0.2f sec).", ImGui.GetStyle().HoverDelayNormal) end
    ImGui.Button("Stationary", sz)
    if ImGui.IsItemHovered(HF.Stationary) then ImGui.SetTooltip("I am a tooltip requiring mouse to be stationary before activating.") end

    -- Using ImGuiHoveredFlags.ForTooltip will pull flags from 'style.HoverFlagsForTooltipMouse' or 'style.HoverFlagsForTooltipNav',
    -- which default value include the ImGuiHoveredFlags.AllowWhenDisabled flag.
    ImGui.BeginDisabled()
    ImGui.Button("Disabled item", sz)
    if ImGui.IsItemHovered(HF.ForTooltip) then ImGui.SetTooltip("I am a tooltip for a disabled item.") end
    ImGui.EndDisabled()
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsTreeNodes()
-------------------------------------------------------------------------------

S.tn = { lines_flags = bit32.bor(ImGuiTreeNodeFlags.DrawLinesFull, ImGuiTreeNodeFlags.DefaultOpen), selection_mask = 0,
    adv_flags = bit32.bor(ImGuiTreeNodeFlags.OpenOnArrow, ImGuiTreeNodeFlags.OpenOnDoubleClick, ImGuiTreeNodeFlags.SpanAvailWidth),
    align_label = false, use_dnd = false }
function DemoWindowWidgetsTreeNodes()
    if not ImGui.TreeNode("Tree Nodes") then return end
    local s = S.tn
    local TN = ImGuiTreeNodeFlags
    -- See see "Examples -> Property Editor" (ShowExampleAppPropertyEditor() function) for a fancier, data-driven tree.
    if ImGui.TreeNode("Basic Trees") then
        for i = 0, 4 do
            -- Use SetNextItemOpen() so set the default state of a node to be open. We could
            -- also use TreeNodeEx() with the ImGuiTreeNodeFlags.DefaultOpen flag to achieve the same thing!
            if i == 0 then ImGui.SetNextItemOpen(true, ImGuiCond.Once) end

            -- Here we use PushID() to generate a unique base ID, and then the "" used as TreeNode id won't conflict.
            -- An alternative to using 'PushID() + TreeNode("", ...)' to generate a unique ID is to use 'TreeNode(i, ...)',
            -- aka pass a number value to be hashed. The demo below uses that technique. Both are fine.
            ImGui.PushID(i)
            if ImGui.TreeNode("", "Child %d", i) then
                ImGui.Text("blah blah")
                ImGui.SameLine()
                if ImGui.SmallButton("button") then end
                ImGui.TreePop()
            end
            ImGui.PopID()
        end
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Hierarchy Lines") then
        HelpMarker("Default option for DrawLinesXXX is stored in style.TreeLinesFlags")
        _, s.lines_flags = ImGui.CheckboxFlags("ImGuiTreeNodeFlags_DrawLinesNone", s.lines_flags, TN.DrawLinesNone)
        _, s.lines_flags = ImGui.CheckboxFlags("ImGuiTreeNodeFlags_DrawLinesFull", s.lines_flags, TN.DrawLinesFull)
        _, s.lines_flags = ImGui.CheckboxFlags("ImGuiTreeNodeFlags_DrawLinesToNodes", s.lines_flags, TN.DrawLinesToNodes)
        local f = s.lines_flags
        if ImGui.TreeNodeEx("Parent", f) then
            if ImGui.TreeNodeEx("Child 1", f) then ImGui.Button("Button for Child 1"); ImGui.TreePop() end
            if ImGui.TreeNodeEx("Child 2", f) then ImGui.Button("Button for Child 2"); ImGui.TreePop() end
            ImGui.Text("Remaining contents")
            ImGui.Text("Remaining contents")
            ImGui.TreePop()
        end
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Clipping Large Trees") then
        ImGui.TextWrapped("- Using ImGuiListClipper with trees is a less easy than on arrays or grids.\n- Refer to 'Demo->Examples->Property Editor' for an example of how to do that.\n- Discuss in #3823")
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Selectable Nodes") then
        HelpMarker("Manually implemented selectable nodes.\nClick to select, Ctrl+Click to toggle, click on arrows or double-click to open.")

        -- Hold in 'selection_mask' a simple representation of what may be user-side selection state.
        -- - You may retain selection state inside or outside your objects in whatever format you see fit.
        --   You may use ImGuiSelectionBasicStorage which is conceptually close to a set<> of identifiers.
        -- - We record which node was clicked and then apply selection at the end of the loop.
        -- - This is a manual and simplified reimplementation of multi-selection, which the full
        --   BeginMultiSelect() API implements better, but which is not trivial to wire for trees.
        local node_clicked_idx = -1
        for node_n = 0, 5 do
            -- Disable the default "open on single-click behavior" + set Selected flag according to our selection.
            -- To alter selection we use if 'IsItemClicked() and not IsItemToggledOpen()', so clicking on an arrow doesn't alter selection.
            -- In a BeginMultiSelect()/EndMultiSelect() we could use IsItemToggledSelection() but here we reimplement and use our own logic.
            local flags = bit32.bor(TN.OpenOnArrow, TN.OpenOnDoubleClick, TN.SpanAvailWidth)
            if bit32.band(s.selection_mask, bit32.lshift(1, node_n)) ~= 0 then flags = bit32.bor(flags, TN.Selected) end
            local is_open = ImGui.TreeNodeEx(node_n, flags, "Selectable Node %d", node_n)
            if ImGui.IsItemClicked() and not ImGui.IsItemToggledOpen() then node_clicked_idx = node_n end
            if is_open then
                ImGui.BulletText("<Node contents here>")
                ImGui.TreePop()
            end
        end
        if node_clicked_idx ~= -1 then
            -- Update selection state (process outside of tree loop to avoid visual inconsistencies during the clicking frame)
            if ImGui.GetIO().KeyCtrl then
                s.selection_mask = bit32.bxor(s.selection_mask, bit32.lshift(1, node_clicked_idx)) -- Ctrl+Click to toggle
            else -- if not (selection_mask & (1 << node_clicked_idx)) -- Depending on selection behavior you want, may want to preserve selection when clicking on item that is part of the selection
                s.selection_mask = bit32.lshift(1, node_clicked_idx) -- Click to single-select
            end
        end
        ImGui.TreePop()
    end

    if ImGui.TreeNode("Advanced") then
        local function FB(name, help)
            _, s.adv_flags = ImGui.CheckboxFlags("ImGuiTreeNodeFlags_" .. name, s.adv_flags, TN[name])
            if help then ImGui.SameLine(); HelpMarker(help) end
        end
        FB("OpenOnArrow"); FB("OpenOnDoubleClick")
        FB("SpanAvailWidth", "Extend hit area to all available width instead of allowing more items to be laid out after the node.")
        FB("SpanFullWidth")
        FB("SpanLabelWidth", "Reduce hit area to the text label and a bit of margin.")
        FB("SpanAllColumns", "For use in Tables only.")
        FB("AllowOverlap")
        FB("Framed", "Draw frame with background (e.g. for CollapsingHeader)")
        FB("FramePadding"); FB("NavLeftJumpsToParent")
        HelpMarker("Default option for DrawLinesXXX is stored in style.TreeLinesFlags")
        FB("DrawLinesNone"); FB("DrawLinesFull"); FB("DrawLinesToNodes")
        _, s.align_label = ImGui.Checkbox("Align label with current X position", s.align_label)
        _, s.use_dnd = ImGui.Checkbox("Make Tree Nodes as drag & drop sources", s.use_dnd)
        if s.align_label then ImGui.Unindent(ImGui.GetTreeNodeToLabelSpacing()) end
        for node_n = 0, 5 do
            local node_flags = s.adv_flags
            if node_n < 3 then
                -- Items 0..2 are Tree Node
                local is_open = ImGui.TreeNodeEx(node_n, node_flags, "Selectable Node %d", node_n)
                if s.use_dnd and ImGui.BeginDragDropSource() then
                    ImGui.SetDragDropPayload("MY_TREENODE_PAYLOAD_TYPE", nil, 0)
                    ImGui.Text("This is a drag and drop source")
                    ImGui.EndDragDropSource()
                end
                if node_n == 2 and bit32.band(s.adv_flags, TN.SpanLabelWidth) ~= 0 then
                    -- Item 2 has an additional inline button to help demonstrate SpanLabelWidth.
                    ImGui.SameLine()
                    if ImGui.SmallButton("button") then end
                end
                if is_open then
                    ImGui.BulletText("Blah blah\nBlah Blah")
                    ImGui.SameLine()
                    ImGui.SmallButton("Button")
                    ImGui.TreePop()
                end
            else
                -- Items 3..5 are Tree Leaves
                -- The only reason we use TreeNode at all is to allow selection of the leaf. Otherwise we can
                -- use BulletText() or advance the cursor by GetTreeNodeToLabelSpacing() and call Text().
                node_flags = bit32.bor(node_flags, TN.Leaf, TN.NoTreePushOnOpen) -- ImGuiTreeNodeFlags.Bullet
                ImGui.TreeNodeEx(node_n, node_flags, "Selectable Leaf %d", node_n)
                if s.use_dnd and ImGui.BeginDragDropSource() then
                    ImGui.SetDragDropPayload("MY_TREENODE_PAYLOAD_TYPE", nil, 0)
                    ImGui.Text("This is a drag and drop source")
                    ImGui.EndDragDropSource()
                end
            end
        end
        if s.align_label then ImGui.Indent(ImGui.GetTreeNodeToLabelSpacing()) end
        ImGui.TreePop()
    end
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] DemoWindowWidgetsVerticalSliders()
-------------------------------------------------------------------------------

S.vs = { int_value = 0, values = { 0.0, 0.60, 0.35, 0.9, 0.70, 0.20, 0.0 }, values2 = { 0.20, 0.80, 0.40, 0.25 } }
function DemoWindowWidgetsVerticalSliders()
    if not ImGui.TreeNode("Vertical Sliders") then return end
    local s = S.vs
    local spacing = 4
    ImGui.PushStyleVar(ImGuiStyleVar.ItemSpacing, ImVec2(spacing, spacing))
    s.int_value = ImGui.VSliderInt("##int", ImVec2(18, 160), s.int_value, 0, 5)
    ImGui.SameLine()
    local values = s.values
    ImGui.PushID("set1")
    for i = 0, 6 do
        if i > 0 then ImGui.SameLine() end
        ImGui.PushID(i)
        ImGui.PushStyleColor(ImGuiCol.FrameBg, HSV(i / 7.0, 0.5, 0.5))
        ImGui.PushStyleColor(ImGuiCol.FrameBgHovered, HSV(i / 7.0, 0.6, 0.5))
        ImGui.PushStyleColor(ImGuiCol.FrameBgActive, HSV(i / 7.0, 0.7, 0.5))
        ImGui.PushStyleColor(ImGuiCol.SliderGrab, HSV(i / 7.0, 0.9, 0.9))
        values[i + 1] = ImGui.VSliderFloat("##v", ImVec2(18, 160), values[i + 1], 0.0, 1.0, "")
        if ImGui.IsItemActive() or ImGui.IsItemHovered() then ImGui.SetTooltip("%.3f", values[i + 1]) end
        ImGui.PopStyleColor(4)
        ImGui.PopID()
    end
    ImGui.PopID()

    ImGui.SameLine()
    ImGui.PushID("set2")
    local rows = 3
    local small_slider_size = ImVec2(18, math.floor((160.0 - (rows - 1) * spacing) / rows))
    for nx = 0, 3 do
        if nx > 0 then ImGui.SameLine() end
        ImGui.BeginGroup()
        for ny = 0, rows - 1 do
            ImGui.PushID(nx * rows + ny)
            s.values2[nx + 1] = ImGui.VSliderFloat("##v", small_slider_size, s.values2[nx + 1], 0.0, 1.0, "")
            if ImGui.IsItemActive() or ImGui.IsItemHovered() then ImGui.SetTooltip("%.3f", s.values2[nx + 1]) end
            ImGui.PopID()
        end
        ImGui.EndGroup()
    end
    ImGui.PopID()

    ImGui.SameLine()
    ImGui.PushID("set3")
    for i = 0, 3 do
        if i > 0 then ImGui.SameLine() end
        ImGui.PushID(i)
        ImGui.PushStyleVar(ImGuiStyleVar.GrabMinSize, 40)
        values[i + 1] = ImGui.VSliderFloat("##v", ImVec2(40, 160), values[i + 1], 0.0, 1.0, "%.2f\nsec")
        ImGui.PopStyleVar()
        ImGui.PopID()
    end
    ImGui.PopID()
    ImGui.PopStyleVar()
    ImGui.TreePop()
end

-------------------------------------------------------------------------------
-- [SECTION] Example App: Main Menu Bar / ShowExampleAppMainMenuBar()
-------------------------------------------------------------------------------
-- - ShowExampleAppMainMenuBar()
-- - ShowExampleMenuFile()
-------------------------------------------------------------------------------

S.menu = { enabled = true, f = 0.5, n = 0, b = true }
-- Note that shortcuts are currently provided for display only
-- (future version will add explicit flags to BeginMenu() to request processing shortcuts)
function ShowExampleMenuFile()
    local s = S.menu
    ImGui.MenuItem("(demo menu)", nil, false, false)
    if ImGui.MenuItem("New") then end
    if ImGui.MenuItem("Open", "Ctrl+O") then end
    if ImGui.BeginMenu("Open Recent") then
        ImGui.MenuItem("fish_hat.c")
        ImGui.MenuItem("fish_hat.inl")
        ImGui.MenuItem("fish_hat.h")
        if ImGui.BeginMenu("More..") then
            ImGui.MenuItem("Hello")
            ImGui.MenuItem("Sailor")
            if ImGui.BeginMenu("Recurse..") then
                ShowExampleMenuFile()
                ImGui.EndMenu()
            end
            ImGui.EndMenu()
        end
        ImGui.EndMenu()
    end
    if ImGui.MenuItem("Save", "Ctrl+S") then end
    if ImGui.MenuItem("Save As..") then end

    ImGui.Separator()
    if ImGui.BeginMenu("Options") then
        _, s.enabled = ImGui.MenuItem("Enabled", "", s.enabled)
        ImGui.BeginChild("child", ImVec2(0, ImGui.GetTextLineHeightWithSpacing() * 5.0), ImGuiChildFlags.Borders)
        for i = 0, 9 do ImGui.Text("Scrolling Text %d", i) end
        ImGui.EndChild()
        s.f = ImGui.SliderFloat("Value", s.f, 0.0, 1.0)
        s.f = ImGui.InputFloat("Input", s.f, 0.1)
        s.n = ImGui.Combo("Combo", s.n, "Yes\0No\0Maybe\0\0")
        ImGui.EndMenu()
    end

    if ImGui.BeginMenu("Colors") then
        local sz = ImGui.GetTextLineHeight()
        for i = 0, ImGuiCol.COUNT - 1 do
            local name = ImGui.GetStyleColorName(i)
            local p = ImGui.GetCursorScreenPos()
            ImGui.GetWindowDrawList():AddRectFilled(p, ImVec2(p.x + sz, p.y + sz), ImGui.GetColorU32(i))
            ImGui.Dummy(ImVec2(sz, sz))
            ImGui.SameLine()
            ImGui.MenuItem(name)
        end
        ImGui.EndMenu()
    end

    -- Here we demonstrate appending again to the "Options" menu (which we already created above)
    -- Of course in this demo it is a little bit silly that this function calls BeginMenu("Options") twice.
    -- In a real code-base using it would make senses to use this feature from very different code locations.
    if ImGui.BeginMenu("Options") then -- <-- Append!
        _, s.b = ImGui.Checkbox("SomeOption", s.b)
        ImGui.EndMenu()
    end

    if ImGui.BeginMenu("Disabled", false) then -- Disabled
        IM_ASSERT(false)
    end
    if ImGui.MenuItem("Checked", nil, true) then end
    ImGui.Separator()
    if ImGui.MenuItem("Quit", "Alt+F4") then end
end

-- Demonstrate creating a "main" fullscreen menu bar and populating it.
-- Note the difference between BeginMainMenuBar() and BeginMenuBar():
-- - BeginMenuBar() = menu-bar inside current window (which needs the ImGuiWindowFlags.MenuBar flag!)
-- - BeginMainMenuBar() = helper to create menu-bar-sized window at the top of the main viewport + call BeginMenuBar() into it.
function ShowExampleAppMainMenuBar()
    if ImGui.BeginMainMenuBar() then
        if ImGui.BeginMenu("File") then
            ShowExampleMenuFile()
            ImGui.EndMenu()
        end
        if ImGui.BeginMenu("Edit") then
            if ImGui.MenuItem("Undo", "Ctrl+Z") then end
            if ImGui.MenuItem("Redo", "Ctrl+Y", false, false) then end -- Disabled item
            ImGui.Separator()
            if ImGui.MenuItem("Cut", "Ctrl+X") then end
            if ImGui.MenuItem("Copy", "Ctrl+C") then end
            if ImGui.MenuItem("Paste", "Ctrl+V") then end
            ImGui.EndMenu()
        end
        ImGui.EndMainMenuBar()
    end
end

-------------------------------------------------------------------------------
-- [SECTION] Style Editor / ShowStyleEditor()
-------------------------------------------------------------------------------
-- - ShowStyleSelector()
-- - ShowStyleEditor()
-------------------------------------------------------------------------------

-- Deep copy of an ImGuiStyle (ImVec2/ImVec4 fields and Colors[] are copied by value)
local function StyleCopy(dst, src)
    for k, v in pairs(src) do
        if k == "Colors" then
            dst.Colors = dst.Colors or {}
            for i, c in pairs(v) do
                if type(c) == "table" then dst.Colors[i] = dst.Colors[i] or ImVec4(); ImVec4_Copy(dst.Colors[i], c) else dst.Colors[i] = c end
            end
        elseif type(v) == "table" and getmetatable(v) ~= nil and type(v[1]) == "number" then
            local c = dst[k]
            if type(c) ~= "table" then c = setmetatable({}, getmetatable(v)); dst[k] = c end
            for _, key in ipairs({ "x", "y", "z", "w" }) do if rawget(v, key) ~= nil then rawset(c, key, rawget(v, key)) end end
        else
            dst[k] = v
        end
    end
    if getmetatable(dst) == nil then setmetatable(dst, getmetatable(src)) end
    return dst
end

local function ColorsEqual(a, b) return a[1] == b[1] and a[2] == b[2] and a[3] == b[3] and a[4] == b[4] end

S.ss = { style_idx = -1 }
-- Demo helper function to select among default colors. See ShowStyleEditor() for more advanced options.
function ImGui.ShowStyleSelector(label)
    -- FIXME: This is a bit tricky to get right as style are functions, they don't register a name nor the fact that one is active.
    -- So we keep track of last active one among our limited selection.
    local s = S.ss
    local style_names = { "Dark", "Light", "Classic" }
    local ret = false
    if ImGui.BeginCombo(label, style_names[s.style_idx + 1] or "") then
        for n = 0, 2 do
            if ImGui.Selectable(style_names[n + 1], s.style_idx == n, ImGuiSelectableFlags.SelectOnNav) then
                s.style_idx = n
                ret = true
                if n == 0 then ImGui.StyleColorsDark() elseif n == 1 then ImGui.StyleColorsLight() else ImGui.StyleColorsClassic() end
            elseif s.style_idx == n then
                ImGui.SetItemDefaultFocus()
            end
        end
        ImGui.EndCombo()
    end
    return ret
end

local function GetTreeLinesFlagsName(flags)
    local TN = ImGuiTreeNodeFlags
    if flags == TN.DrawLinesNone then return "DrawLinesNone" end
    if flags == TN.DrawLinesFull then return "DrawLinesFull" end
    if flags == TN.DrawLinesToNodes then return "DrawLinesToNodes" end
    return ""
end

S.se = { ref_saved_style = nil, init = true, output_dest = 0, output_only_modified = true, alpha_flags = 0, filter = nil }
function ImGui.ShowStyleEditor(ref)
    -- You can pass in a reference ImGuiStyle structure to compare to, revert to and save to
    -- (without a reference style, we will use one compared locally as a reference)
    local se = S.se
    local style = ImGui.GetStyle()
    if se.ref_saved_style == nil then se.ref_saved_style = {} end

    -- Default to using internal storage as reference
    if se.init and ref == nil then StyleCopy(se.ref_saved_style, style) end
    se.init = false
    if ref == nil then ref = se.ref_saved_style end

    -- The logic behind dynamically changing 'max_border_size' is to not encourage people to increase border size too much: it'll likely reveal lots of subtle rendering artifacts and this isn't a priority right now.
    -- Note that _MainScale is currently internal PLEASE DO NOT USE IN YOUR CODE.
    local default_border_size = math.floor(style._MainScale or 1.0)
    local max_border_size = math.max(default_border_size, 2.0)
    local function SF(name, mn, mx, fmt) if style[name] ~= nil then style[name] = ImGui.SliderFloat(name, style[name], mn, mx, fmt or "%.0f") end end
    local function SF2(name, mn, mx, fmt) if style[name] ~= nil then ImGui.SliderFloat2(name, style[name], mn, mx, fmt or "%.0f") end end
    local function DF(name, speed, mn, mx, fmt, flags) if style[name] ~= nil then style[name] = ImGui.DragFloat(name, style[name], speed, mn, mx, fmt or "%.0f", flags) end end

    ImGui.PushItemWidth(ImGui.GetWindowWidth() * 0.50)

    -- General
    ImGui.SeparatorText("General")
    if bit32.band(ImGui.GetIO().BackendFlags, ImGuiBackendFlags.RendererHasTextures) == 0 then
        ImGui.BulletText("Warning: Font scaling will NOT be smooth, because\nImGuiBackendFlags_RendererHasTextures is not set!")
        ImGui.BulletText("For instructions, see:")
        ImGui.SameLine()
        ImGui.TextLinkOpenURL("docs/BACKENDS.md", "https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md")
    end
    if ImGui.ShowStyleSelector("Colors##Selector") then StyleCopy(se.ref_saved_style, style) end
    if ImGui.ShowFontSelector then ImGui.ShowFontSelector("Fonts##Selector") end
    local changed
    style.FontSizeBase, changed = ImGui.DragFloat("FontSizeBase", style.FontSizeBase, 0.20, 5.0, 100.0, "%.0f")
    if changed then style._NextFrameFontSizeBase = style.FontSizeBase end -- FIXME: Temporary hack until we finish remaining work.
    ImGui.SameLine(0.0, 0.0); ImGui.Text(" (out %.2f)", ImGui.GetFontSize())
    style.FontScaleMain = ImGui.DragFloat("FontScaleMain", style.FontScaleMain, 0.02, 0.5, 4.0)
    ImGui.BeginDisabled(ImGui.GetIO().ConfigDpiScaleFonts == true)
    style.FontScaleDpi = ImGui.DragFloat("FontScaleDpi", style.FontScaleDpi, 0.02, 0.5, 4.0)
    ImGui.SetItemTooltip("When io.ConfigDpiScaleFonts is set, this value is automatically overwritten.")
    ImGui.EndDisabled()

    -- Simplified Settings (expose floating-pointer border sizes as boolean representing 0.0 or 1.0)
    style.FrameRounding, changed = ImGui.SliderFloat("FrameRounding", style.FrameRounding, 0.0, 12.0, "%.0f")
    if changed then style.GrabRounding = style.FrameRounding end -- Make GrabRounding always the same value as FrameRounding
    local p, border
    p, border = ImGui.Checkbox("WindowBorder", style.WindowBorderSize > 0.0); if p then style.WindowBorderSize = border and default_border_size or 0.0 end
    ImGui.SameLine()
    p, border = ImGui.Checkbox("FrameBorder", style.FrameBorderSize > 0.0); if p then style.FrameBorderSize = border and default_border_size or 0.0 end
    ImGui.SameLine()
    p, border = ImGui.Checkbox("PopupBorder", style.PopupBorderSize > 0.0); if p then style.PopupBorderSize = border and default_border_size or 0.0 end

    -- Save/Revert button
    if ImGui.Button("Save Ref") then StyleCopy(se.ref_saved_style, style); if ref ~= se.ref_saved_style then StyleCopy(ref, style) end end
    ImGui.SameLine()
    if ImGui.Button("Revert Ref") then StyleCopy(style, ref) end
    ImGui.SameLine()
    HelpMarker("Save/Revert in local non-persistent storage. Default Colors definition are not affected. Use \"Export\" below to save them somewhere.")

    ImGui.SeparatorText("Details")
    if ImGui.BeginTabBar("##tabs", ImGuiTabBarFlags.None) then
        if ImGui.BeginTabItem("Sizes") then
            ImGui.SeparatorText("Main")
            SF2("WindowPadding", 0.0, 20.0); SF2("FramePadding", 0.0, 20.0); SF2("ItemSpacing", 0.0, 20.0)
            SF2("ItemInnerSpacing", 0.0, 20.0); SF2("TouchExtraPadding", 0.0, 10.0)
            SF("IndentSpacing", 0.0, 30.0); SF("GrabMinSize", 1.0, 20.0)

            ImGui.SeparatorText("Borders")
            SF("WindowBorderSize", 0.0, max_border_size); SF("ChildBorderSize", 0.0, max_border_size)
            SF("PopupBorderSize", 0.0, max_border_size); SF("FrameBorderSize", 0.0, max_border_size)

            ImGui.SeparatorText("Rounding")
            SF("WindowRounding", 0.0, 12.0); SF("ChildRounding", 0.0, 12.0); SF("FrameRounding", 0.0, 12.0)
            SF("PopupRounding", 0.0, 12.0); SF("GrabRounding", 0.0, 12.0); SF("MenuItemRounding", 0.0, 12.0)
            -- NB: SelectableRounding is intentionally NOT made visible here. We don't want to encourage people using that.

            ImGui.SeparatorText("Scrollbar")
            SF("ScrollbarSize", 1.0, 20.0); SF("ScrollbarRounding", 0.0, 12.0); SF("ScrollbarPadding", 0.0, 10.0)

            ImGui.SeparatorText("Tabs")
            SF("TabBorderSize", 0.0, max_border_size); SF("TabBarBorderSize", 0.0, max_border_size)
            SF("TabBarOverlineSize", 0.0, math.max(3.0, max_border_size))
            ImGui.SameLine(); HelpMarker("Overline is only drawn over the selected tab when ImGuiTabBarFlags_DrawSelectedOverline is set.")
            DF("TabMinWidthBase", 0.5, 1.0, 500.0); DF("TabMinWidthShrink", 0.5, 1.0, 500.0, "%0.f")
            if style.TabCloseButtonMinWidthSelected ~= nil then
                DF("TabCloseButtonMinWidthSelected", 0.5, -1.0, 100.0, (style.TabCloseButtonMinWidthSelected < 0.0) and "%.0f (Always)" or "%.0f")
                DF("TabCloseButtonMinWidthUnselected", 0.5, -1.0, 100.0, (style.TabCloseButtonMinWidthUnselected < 0.0) and "%.0f (Always)" or "%.0f")
            end
            SF("TabRounding", 0.0, 12.0)

            ImGui.SeparatorText("Tables")
            SF2("CellPadding", 0.0, 20.0)
            style.TableAngledHeadersAngle = ImGui.SliderAngle("TableAngledHeadersAngle", style.TableAngledHeadersAngle, -50.0, 50.0)
            SF2("TableAngledHeadersTextAlign", 0.0, 1.0, "%.2f")

            ImGui.SeparatorText("Trees")
            local combo_open = ImGui.BeginCombo("TreeLinesFlags", GetTreeLinesFlagsName(style.TreeLinesFlags))
            ImGui.SameLine()
            HelpMarker("[Experimental] Tree lines may not work in all situations (e.g. using a clipper) and may incurs slight traversal overhead.\n\nImGuiTreeNodeFlags_DrawLinesFull is faster than ImGuiTreeNodeFlags_DrawLinesToNode.")
            if combo_open then
                local TN = ImGuiTreeNodeFlags
                for _, option in ipairs({ TN.DrawLinesNone, TN.DrawLinesFull, TN.DrawLinesToNodes }) do
                    if ImGui.Selectable(GetTreeLinesFlagsName(option), style.TreeLinesFlags == option) then style.TreeLinesFlags = option end
                end
                ImGui.EndCombo()
            end
            SF("TreeLinesSize", 0.0, max_border_size); SF("TreeLinesRounding", 0.0, 12.0)

            ImGui.SeparatorText("Windows")
            SF2("WindowTitleAlign", 0.0, 1.0, "%.2f"); SF("WindowBorderHoverPadding", 1.0, 20.0)
            local window_menu_button_position = style.WindowMenuButtonPosition + 1
            window_menu_button_position, changed = ImGui.Combo("WindowMenuButtonPosition", window_menu_button_position, "None\0Left\0Right\0")
            if changed then style.WindowMenuButtonPosition = window_menu_button_position - 1 end

            ImGui.SeparatorText("Widgets")
            SF("ColorMarkerSize", 0.0, 8.0)
            style.ColorButtonPosition = ImGui.Combo("ColorButtonPosition", style.ColorButtonPosition, "Left\0Right\0")
            SF2("ButtonTextAlign", 0.0, 1.0, "%.2f")
            ImGui.SameLine(); HelpMarker("Alignment applies when a button is larger than its text content.")
            SF2("SelectableTextAlign", 0.0, 1.0, "%.2f")
            ImGui.SameLine(); HelpMarker("Alignment applies when a selectable is larger than its text content.")
            SF("SeparatorSize", 0.0, 10.0); SF("SeparatorTextBorderSize", 0.0, 10.0)
            SF2("SeparatorTextAlign", 0.0, 1.0, "%.2f"); SF2("SeparatorTextPadding", 0.0, 40.0)
            SF("LogSliderDeadzone", 0.0, 12.0); SF("ImageRounding", 0.0, 12.0); SF("ImageBorderSize", 0.0, max_border_size)

            ImGui.SeparatorText("Docking")
            -- SetCursorPosX(GetCursorPosX() + CalcItemWidth() - GetFrameHeight())
            _, style.DockingNodeHasCloseButton = ImGui.Checkbox("DockingNodeHasCloseButton", style.DockingNodeHasCloseButton)
            SF("DockingSeparatorSize", 0.0, 12.0)

            ImGui.SeparatorText("Tooltips")
            for n = 0, 1 do
                local key = (n == 0) and "HoverFlagsForTooltipMouse" or "HoverFlagsForTooltipNav"
                if ImGui.TreeNodeEx(key) then
                    for _, f in ipairs({ "DelayNone", "DelayShort", "DelayNormal", "Stationary", "NoSharedDelay" }) do
                        _, style[key] = ImGui.CheckboxFlags("ImGuiHoveredFlags_" .. f, style[key], ImGuiHoveredFlags[f])
                    end
                    ImGui.TreePop()
                end
            end

            ImGui.SeparatorText("Misc")
            SF2("DisplayWindowPadding", 0.0, 30.0); ImGui.SameLine(); HelpMarker("Apply to regular windows: amount which we enforce to keep visible when moving near edges of your screen.")
            SF2("DisplaySafeAreaPadding", 0.0, 30.0); ImGui.SameLine(); HelpMarker("Apply to every windows, menus, popups, tooltips: amount where we avoid displaying contents. Adjust if you cannot see the edges of your screen (e.g. on a TV where scaling has not been configured).")
            ImGui.EndTabItem()
        end

        if ImGui.BeginTabItem("Colors") then
            if ImGui.Button("Export") then
                if se.output_dest == 0 then ImGui.LogToClipboard() else ImGui.LogToTTY() end
                ImGui.LogText("ImVec4* colors = GetStyle().Colors;\n")
                for i = 0, ImGuiCol.COUNT - 1 do
                    local col = style.Colors[i]
                    local name = ImGui.GetStyleColorName(i)
                    if not se.output_only_modified or not ColorsEqual(col, ref.Colors[i]) then
                        ImGui.LogText("colors[ImGuiCol_%s]%s= ImVec4(%.2ff, %.2ff, %.2ff, %.2ff);\n", name, string.rep(" ", math.max(0, 23 - #name)), col.x, col.y, col.z, col.w)
                    end
                end
                ImGui.LogFinish()
            end
            ImGui.SameLine(); ImGui.SetNextItemWidth(ImGui.GetFontSize() * 10)
            se.output_dest = ImGui.Combo("##output_type", se.output_dest, "To Clipboard\0To TTY\0")
            ImGui.SameLine(); _, se.output_only_modified = ImGui.Checkbox("Only Modified Colors", se.output_only_modified)

            local CE = ImGuiColorEditFlags
            if ImGui.RadioButtonEx("Opaque", se.alpha_flags == CE.AlphaOpaque) then se.alpha_flags = CE.AlphaOpaque end ImGui.SameLine()
            if ImGui.RadioButtonEx("Alpha", se.alpha_flags == CE.None) then se.alpha_flags = CE.None end ImGui.SameLine()
            if ImGui.RadioButtonEx("Both", se.alpha_flags == CE.AlphaPreviewHalf) then se.alpha_flags = CE.AlphaPreviewHalf end ImGui.SameLine()
            HelpMarker("In the color list:\nLeft-click on color square to open color picker,\nRight-click to open edit options menu.")

            se.filter = se.filter or ImGuiTextFilter()
            ImGui.SetNextItemWidth(-FLT_MIN)
            se.filter:DrawWithHint("##FilterColors", "Filter Colors (incl -excl)")

            ImGui.SetNextWindowSizeConstraints(ImVec2(0.0, ImGui.GetTextLineHeightWithSpacing() * 10), ImVec2(FLT_MAX, FLT_MAX))
            ImGui.BeginChild("##colors", ImVec2(0, 0), bit32.bor(ImGuiChildFlags.Borders, ImGuiChildFlags.NavFlattened), bit32.bor(ImGuiWindowFlags.AlwaysVerticalScrollbar, ImGuiWindowFlags.AlwaysHorizontalScrollbar))
            ImGui.PushItemWidth(ImGui.GetFontSize() * -12)
            -- [Luau] clipped: only visible rows are submitted (upstream submits every color)
            local visible_cols = {}
            for i = 0, ImGuiCol.COUNT - 1 do
                if se.filter:PassFilter(ImGui.GetStyleColorName(i)) then visible_cols[#visible_cols + 1] = i end
            end
            local clipper = ImGuiListClipper()
            clipper:Begin(#visible_cols)
            while clipper:Step() do for row = clipper.DisplayStart, clipper.DisplayEnd - 1 do
                local i = visible_cols[row + 1]
                local name = ImGui.GetStyleColorName(i)
                do
                    ImGui.PushID(i)
                    if ImGui.DebugFlashStyleColor then
                        if ImGui.Button("?") then ImGui.DebugFlashStyleColor(i) end
                        ImGui.SetItemTooltip("Flash given color to identify places where it is used.")
                        ImGui.SameLine()
                    end
                    ImGui.ColorEdit4("##color", style.Colors[i], bit32.bor(CE.AlphaBar, se.alpha_flags))
                    if not ColorsEqual(style.Colors[i], ref.Colors[i]) then
                        -- Tips: in a real user application, you may want to merge and use an icon font into the main font,
                        -- so instead of "Save"/"Revert" you'd use icons!
                        -- Read the FAQ and docs/FONTS.md about using icon fonts. It's really easy and super convenient!
                        ImGui.SameLine(0.0, style.ItemInnerSpacing.x); if ImGui.Button("Save") then ImVec4_Copy(ref.Colors[i], style.Colors[i]) end
                        ImGui.SameLine(0.0, style.ItemInnerSpacing.x); if ImGui.Button("Revert") then ImVec4_Copy(style.Colors[i], ref.Colors[i]) end
                    end
                    ImGui.SameLine(0.0, style.ItemInnerSpacing.x)
                    ImGui.TextUnformatted(name)
                    ImGui.PopID()
                end
            end end
            clipper:End()
            ImGui.PopItemWidth()
            ImGui.EndChild()
            ImGui.EndTabItem()
        end

        if ImGui.BeginTabItem("Fonts") then
            if ImGui.ShowFontAtlas then ImGui.ShowFontAtlas(ImGui.GetIO().Fonts) else DemoNotPorted("ShowFontAtlas") end
            ImGui.EndTabItem()
        end

        if ImGui.BeginTabItem("Rendering") then
            _, style.AntiAliasedLines = ImGui.Checkbox("Anti-aliased lines", style.AntiAliasedLines)
            ImGui.SameLine()
            HelpMarker("When disabling anti-aliasing lines, you'll probably want to disable borders in your style as well.")
            ImGui.BeginDisabled(style.AntiAliasedLines == false)
            _, style.AntiAliasedLineEnds = ImGui.Checkbox("Anti-aliased line ends", style.AntiAliasedLineEnds)
            ImGui.EndDisabled()
            _, style.AntiAliasedFill = ImGui.Checkbox("Anti-aliased fill", style.AntiAliasedFill)
            local io = ImGui.GetIO()
            _, io.ConfigDebugDrawListDefaultsToStrokeLegacy = ImGui.Checkbox("Debug: DrawList Defaults to _StrokeLegacy", io.ConfigDebugDrawListDefaultsToStrokeLegacy == true)

            ImGui.PushItemWidth(ImGui.GetFontSize() * 8)
            -- [port] library still stores the pre-1.93 CurveTessellationTol (== MaxError * MaxError)
            local curve_err = ImGui.DragFloat("Curve Tessellation Max Error", math.sqrt(style.CurveTessellationTol), 0.02, 0.10, 10.0, "%.2f")
            if curve_err < 0.10 then curve_err = 0.10 end
            style.CurveTessellationTol = curve_err * curve_err

            -- When editing the "Circle Segment Max Error" value, draw a preview of its effect on auto-tessellated circles.
            style.CircleTessellationMaxError = ImGui.DragFloat("Circle Tessellation Max Error", style.CircleTessellationMaxError, 0.005, 0.10, 5.0, "%.2f", ImGuiSliderFlags.AlwaysClamp)
            local show_samples = ImGui.IsItemActive()
            if show_samples then ImGui.SetNextWindowPos(ImGui.GetCursorScreenPos()) end
            if show_samples and ImGui.BeginTooltip() then
                ImGui.TextUnformatted("(R = radius, N = approx number of segments)")
                ImGui.Spacing()
                local draw_list = ImGui.GetWindowDrawList()
                local min_widget_width = ImGui.CalcTextSize("R: MMM\nN: MMM").x
                for n = 0, 7 do
                    local RAD_MIN, RAD_MAX = 5.0, 70.0
                    local rad = RAD_MIN + (RAD_MAX - RAD_MIN) * n / (8.0 - 1.0)
                    ImGui.BeginGroup()

                    -- N is not always exact here due to how PathArcTo() function work internally
                    ImGui.Text("R: %.f\nN: %d", rad, draw_list:_CalcCircleAutoSegmentCount(rad))
                    local canvas_width = math.max(min_widget_width, rad * 2.0)
                    local offset_x = math.floor(canvas_width * 0.5)
                    local offset_y = math.floor(RAD_MAX)
                    local p1 = ImGui.GetCursorScreenPos()
                    draw_list:AddCircle(ImVec2(p1.x + offset_x, p1.y + offset_y), rad, ImGui.GetColorU32(ImGuiCol.Text))
                    ImGui.Dummy(ImVec2(canvas_width, RAD_MAX * 2))

                    -- local p2 = ImGui.GetCursorScreenPos()
                    -- draw_list:AddCircleFilled(ImVec2(p2.x + offset_x, p2.y + offset_y), rad, ImGui.GetColorU32(ImGuiCol.Text))
                    -- ImGui.Dummy(ImVec2(canvas_width, RAD_MAX * 2))

                    ImGui.EndGroup()
                    ImGui.SameLine()
                end
                ImGui.EndTooltip()
            end
            ImGui.SameLine()
            HelpMarker("When drawing circle primitives with \"num_segments == 0\" tessellation will be calculated automatically.")
            style.Alpha = ImGui.DragFloat("Global Alpha", style.Alpha, 0.005, 0.20, 1.0, "%.2f") -- Not exposing zero here so user doesn't "lose" the UI (zero alpha clips all widgets). But application code could have a toggle to switch between zero and non-zero.
            style.DisabledAlpha = ImGui.DragFloat("Disabled Alpha", style.DisabledAlpha, 0.005, 0.0, 1.0, "%.2f")
            ImGui.SameLine(); HelpMarker("Additional alpha multiplier for disabled items (multiply over current value of Alpha).")
            ImGui.PopItemWidth()
            ImGui.EndTabItem()
        end
        ImGui.EndTabBar()
    end
    ImGui.PopItemWidth()
end
end --[[ imgui_demo_widgets.lua ]]

do --[[ About window ]]
-- Demo tools: ShowAboutWindow(), ShowFontAtlas(), ShowFontSelector(), ShowDebugLogWindow(), ShowIDStackToolWindow()
local _

-------------------------------------------------------------------------------
-- [SECTION] About Window / ShowAboutWindow()
-- Access from Dear ImGui Demo -> Tools -> About
-------------------------------------------------------------------------------

local show_config_info = false
function ImGui.ShowAboutWindow(p_open)
    local visible
    p_open, visible = ImGui.Begin("About Dear ImGui", p_open, ImGuiWindowFlags.AlwaysAutoResize)
    if not visible then ImGui.End(); return p_open end
    ImGui.Text("Dear ImGui %s (%d)", IMGUI_VERSION, IMGUI_VERSION_NUM)
    ImGui.TextLinkOpenURL("Homepage", "https://github.com/ocornut/imgui"); ImGui.SameLine()
    ImGui.TextLinkOpenURL("FAQ", "https://github.com/ocornut/imgui/blob/master/docs/FAQ.md"); ImGui.SameLine()
    ImGui.TextLinkOpenURL("Wiki", "https://github.com/ocornut/imgui/wiki"); ImGui.SameLine()
    ImGui.TextLinkOpenURL("Extensions", "https://github.com/ocornut/imgui/wiki/Useful-Extensions"); ImGui.SameLine()
    ImGui.TextLinkOpenURL("Releases", "https://github.com/ocornut/imgui/releases"); ImGui.SameLine()
    ImGui.TextLinkOpenURL("Funding", "https://github.com/ocornut/imgui/wiki/Funding")
    ImGui.Separator()
    ImGui.Text("(c) 2014-2026 Omar Cornut")
    ImGui.Text("Developed by Omar Cornut and all Dear ImGui contributors.")
    ImGui.Text("Dear ImGui is licensed under the MIT License, see LICENSE for more information.")
    ImGui.Text("If your company uses this, please consider funding the project.")
    ImGui.Text("Luau/Roblox port: imgui_impl_roblox (software rasterizer into EditableImage tiles).")

    _, show_config_info = ImGui.Checkbox("Config/Build Information", show_config_info)
    if show_config_info then
        local io = ImGui.GetIO()
        local style = ImGui.GetStyle()
        local copy_to_clipboard = ImGui.Button("Copy to clipboard")
        local child_size = ImVec2(0, ImGui.GetTextLineHeightWithSpacing() * 18)
        ImGui.BeginChild(ImGui.GetID("cfg_infos"), child_size, ImGuiChildFlags.FrameStyle)
        if copy_to_clipboard then
            ImGui.LogToClipboard()
            ImGui.LogText("// (Copy from the next line. Keep the ``` markers for formatting.)\n")
            ImGui.LogText("```cpp\n") -- Back quotes will make text appears without formatting when pasting on GitHub
        end
        ImGui.Text("Dear ImGui %s (%d)", IMGUI_VERSION, IMGUI_VERSION_NUM)
        ImGui.Separator()
        ImGui.Text("define: IMGUI_HAS_VIEWPORT")
        ImGui.Text("define: IMGUI_HAS_DOCK")
        ImGui.Text("runtime: Luau (%s)", _VERSION or "?")
        ImGui.Separator()
        ImGui.Text("io.BackendPlatformName: %s", io.BackendPlatformName or "NULL")
        ImGui.Text("io.BackendRendererName: %s", io.BackendRendererName or "NULL")
        ImGui.Text("io.ConfigFlags: 0x%08X", io.ConfigFlags)
        local CF = ImGuiConfigFlags
        for _, n in ipairs({ "NavEnableKeyboard", "NavEnableGamepad", "NoMouse", "NoMouseCursorChange", "NoKeyboard", "DockingEnable", "ViewportsEnable" }) do
            if CF[n] and bit32.band(io.ConfigFlags, CF[n]) ~= 0 then ImGui.Text(" %s", n) end
        end
        for _, n in ipairs({ "MouseDrawCursor", "ConfigDpiScaleFonts", "ConfigDpiScaleViewports", "ConfigViewportsNoAutoMerge", "ConfigViewportsNoTaskBarIcon",
            "ConfigViewportsNoDecoration", "ConfigViewportsNoDefaultParent", "ConfigDockingNoSplit", "ConfigDockingNoDockingOver", "ConfigDockingWithShift",
            "ConfigDockingAlwaysTabBar", "ConfigDockingTransparentPayload", "ConfigMacOSXBehaviors", "ConfigNavMoveSetMousePos", "ConfigNavCaptureKeyboard",
            "ConfigInputTextCursorBlink", "ConfigWindowsResizeFromEdges", "ConfigWindowsMoveFromTitleBarOnly" }) do
            if io[n] == true then ImGui.Text("io.%s", n) end
        end
        if (io.ConfigMemoryCompactTimer or -1) >= 0.0 then ImGui.Text("io.ConfigMemoryCompactTimer = %.1f", io.ConfigMemoryCompactTimer) end
        ImGui.Text("io.BackendFlags: 0x%08X", io.BackendFlags)
        local BF = ImGuiBackendFlags
        for _, n in ipairs({ "HasGamepad", "HasMouseCursors", "HasSetMousePos", "PlatformHasViewports", "HasMouseHoveredViewport", "HasParentViewport",
            "RendererHasVtxOffset", "RendererHasTextures", "RendererHasViewports" }) do
            if BF[n] and bit32.band(io.BackendFlags, BF[n]) ~= 0 then ImGui.Text(" %s", n) end
        end
        ImGui.Separator()
        local atlas = io.Fonts
        ImGui.Text("io.Fonts: %d fonts, Flags: 0x%08X, TexSize: %d,%d", atlas.Fonts.Size, atlas.Flags or 0, atlas.TexData and atlas.TexData.Width or 0, atlas.TexData and atlas.TexData.Height or 0)
        ImGui.Text("io.Fonts->FontLoaderName: %s", atlas.FontLoaderName or "NULL")
        ImGui.Text("io.DisplaySize: %.2f,%.2f", io.DisplaySize.x, io.DisplaySize.y)
        ImGui.Text("io.DisplayFramebufferScale: %.2f,%.2f", io.DisplayFramebufferScale.x, io.DisplayFramebufferScale.y)
        ImGui.Separator()
        ImGui.Text("style.WindowPadding: %.2f,%.2f", style.WindowPadding.x, style.WindowPadding.y)
        ImGui.Text("style.WindowBorderSize: %.2f", style.WindowBorderSize)
        ImGui.Text("style.FramePadding: %.2f,%.2f", style.FramePadding.x, style.FramePadding.y)
        ImGui.Text("style.FrameRounding: %.2f", style.FrameRounding)
        ImGui.Text("style.FrameBorderSize: %.2f", style.FrameBorderSize)
        ImGui.Text("style.ItemSpacing: %.2f,%.2f", style.ItemSpacing.x, style.ItemSpacing.y)
        ImGui.Text("style.ItemInnerSpacing: %.2f,%.2f", style.ItemInnerSpacing.x, style.ItemInnerSpacing.y)
        if copy_to_clipboard then
            ImGui.LogText("\n```\n")
            ImGui.LogFinish()
        end
        ImGui.EndChild()
    end
    ImGui.End()
    return p_open
end
end --[[ About window ]]

return true
end

__FILES['imgui_draw.lua'] = function()
--- Dear ImGui WIP
-- (drawing and font code)

--
-- Index of this file:
--
-- [SECTION] STB libraries implementation
-- [SECTION] Style functions
-- [SECTION] ImDrawList
-- [SECTION] ImTriangulator, ImDrawList concave polygon fill
-- [SECTION] ImDrawListSplitter
-- [SECTION] ImDrawData
-- [SECTION] Helpers ShadeVertsXXX functions
-- [SECTION] ImFontConfig
-- [SECTION] ImFontAtlas, ImFontAtlasBuilder
-- [SECTION] ImFontAtlas: backend for stb_truetype
-- [SECTION] ImFontAtlas: glyph ranges helpers
-- [SECTION] ImFontGlyphRangesBuilder
-- [SECTION] ImFontBaked, ImFont
-- [SECTION] ImGui Internal Render Helpers
-- [SECTION] Decompression code
-- [SECTION] Default font data (ProggyClean.ttf)
-- [SECTION] Default font data (ProggyForever.ttf)
--

FONT_ATLAS_DEFAULT_TEX_DATA_W = 122 -- Actual texture will be 2 times that + 1 spacing.
FONT_ATLAS_DEFAULT_TEX_DATA_H = 27

local IM_DRAWLIST_TEX_LINES_WIDTH_MAX = 32 -- The maximum line width to bake anti-aliased textures for.

local writef64, writeu32, readf64, readu32 = buffer.writef64, buffer.writeu32, buffer.readf64, buffer.readu32
-- Write vertex i (1-based) of a VtxBuffer.Buf
local function WV(b, i, x, y, u, v, col)
    local o = (i - 1) * 36
    writef64(b, o, x); writef64(b, o + 8, y); writef64(b, o + 16, u); writef64(b, o + 24, v); writeu32(b, o + 32, col)
end
local function WVP(b, i, p, uv, col) WV(b, i, p.x, p.y, uv.x, uv.y, col) end

local IM_FONTGLYPH_INDEX_UNUSED    = 0xFFFF -- ((ImU16)-1)
local IM_FONTGLYPH_INDEX_NOT_FOUND = 0xFFFE -- ((ImU16)-2)

--- @param str string
--- @return table
--- @nodiscard
--- @package
local function str_to_table(str)
    local t = {} for i = 1, #str do t[i] = string.sub(str, i, i) end return t
end

--- @param buf  char[] # 1-based
--- @param base int    # 1-based start index
--- @param u32  ImU32
local function write_u32(buf, base, u32)
    buf[base + 0] = bit32.band(u32, 0xFF)
    buf[base + 1] = bit32.band(bit32.rshift(u32, 8), 0xFF)
    buf[base + 2] = bit32.band(bit32.rshift(u32, 16), 0xFF)
    buf[base + 3] = bit32.band(bit32.rshift(u32, 24), 0xFF)
end

-- A work of art lies ahead! (. = white layer, X = black layer, others are blank)
-- The 2x2 white texels on the top left are the ones we'll use everywhere in Dear ImGui to render filled shapes.
-- (This is used when io.MouseDrawCursor = true)
local FONT_ATLAS_DEFAULT_TEX_DATA_PIXELS = str_to_table(
    "..-         -XXXXXXX-    X    -           X           -XXXXXXX          -          XXXXXXX-     XX          - XX       XX " ..
    "..-         -X.....X-   X.X   -          X.X          -X.....X          -          X.....X-    X..X         -X..X     X..X" ..
    "---         -XXX.XXX-  X...X  -         X...X         -X....X           -           X....X-    X..X         -X...X   X...X" ..
    "X           -  X.X  - X.....X -        X.....X        -X...X            -            X...X-    X..X         - X...X X...X " ..
    "XX          -  X.X  -X.......X-       X.......X       -X..X.X           -           X.X..X-    X..X         -  X...X...X  " ..
    "X.X         -  X.X  -XXXX.XXXX-       XXXX.XXXX       -X.X X.X          -          X.X X.X-    X..XXX       -   X.....X   " ..
    "X..X        -  X.X  -   X.X   -          X.X          -XX   X.X         -         X.X   XX-    X..X..XXX    -    X...X    " ..
    "X...X       -  X.X  -   X.X   -    XX    X.X    XX    -      X.X        -        X.X      -    X..X..X..XX  -     X.X     " ..
    "X....X      -  X.X  -   X.X   -   X.X    X.X    X.X   -       X.X       -       X.X       -    X..X..X..X.X -    X...X    " ..
    "X.....X     -  X.X  -   X.X   -  X..X    X.X    X..X  -        X.X      -      X.X        -XXX X..X..X..X..X-   X.....X   " ..
    "X......X    -  X.X  -   X.X   - X...XXXXXX.XXXXXX...X -         X.X   XX-XX   X.X         -X..XX........X..X-  X...X...X  " ..
    "X.......X   -  X.X  -   X.X   -X.....................X-          X.X X.X-X.X X.X          -X...X...........X- X...X X...X " ..
    "X........X  -  X.X  -   X.X   - X...XXXXXX.XXXXXX...X -           X.X..X-X..X.X           - X..............X-X...X   X...X" ..
    "X.........X -XXX.XXX-   X.X   -  X..X    X.X    X..X  -            X...X-X...X            -  X.............X-X..X     X..X" ..
    "X..........X-X.....X-   X.X   -   X.X    X.X    X.X   -           X....X-X....X           -  X.............X- XX       XX " ..
    "X......XXXXX-XXXXXXX-   X.X   -    XX    X.X    XX    -          X.....X-X.....X          -   X............X--------------" ..
    "X...X..X    ---------   X.X   -          X.X          -          XXXXXXX-XXXXXXX          -   X...........X -             " ..
    "X..X X..X   -       -XXXX.XXXX-       XXXX.XXXX       -------------------------------------    X..........X -             " ..
    "X.X  X..X   -       -X.......X-       X.......X       -    XX           XX    -           -    X..........X -             " ..
    "XX    X..X  -       - X.....X -        X.....X        -   X.X           X.X   -           -     X........X  -             " ..
    "      X..X  -       -  X...X  -         X...X         -  X..X           X..X  -           -     X........X  -             " ..
    "       XX   -       -   X.X   -          X.X          - X...XXXXXXXXXXXXX...X -           -     XXXXXXXXXX  -             " ..
    "-------------       -    X    -           X           -X.....................X-           -------------------             " ..
    "                    ----------------------------------- X...XXXXXXXXXXXXX...X -                                           " ..
    "                                                      -  X..X           X..X  -                                           " ..
    "                                                      -   X.X           X.X   -                                           " ..
    "                                                      -    XX           XX    -                                           "
)

local FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA = {
    -- Pos ..........  Size .........  Offset .......
    { ImVec2(  0,  3), ImVec2(12, 19), ImVec2( 0,  0) }, -- ImGuiMouseCursor.Arrow
    { ImVec2( 13,  0), ImVec2( 7, 16), ImVec2( 1,  8) }, -- ImGuiMouseCursor.TextInput
    { ImVec2( 31,  0), ImVec2(23, 23), ImVec2(11, 11) }, -- ImGuiMouseCursor.ResizeAll
    { ImVec2( 21,  0), ImVec2( 9, 23), ImVec2( 4, 11) }, -- ImGuiMouseCursor.ResizeNS
    { ImVec2( 55, 18), ImVec2(23,  9), ImVec2(11,  4) }, -- ImGuiMouseCursor.ResizeEW
    { ImVec2( 73,  0), ImVec2(17, 17), ImVec2( 8,  8) }, -- ImGuiMouseCursor.ResizeNESW
    { ImVec2( 55,  0), ImVec2(17, 17), ImVec2( 8,  8) }, -- ImGuiMouseCursor.ResizeNWSE
    { ImVec2( 91,  0), ImVec2(17, 22), ImVec2( 5,  0) }, -- ImGuiMouseCursor.Hand
    { ImVec2(  0,  3), ImVec2(12, 19), ImVec2( 0,  0) }, -- ImGuiMouseCursor.Wait     -- Arrow + custom code in ImGui.RenderMouseCursor()
    { ImVec2(  0,  3), ImVec2(12, 19), ImVec2( 0,  0) }, -- ImGuiMouseCursor.Progress -- Arrow + custom code in ImGui.RenderMouseCursor()
    { ImVec2(109,  0), ImVec2(13, 15), ImVec2( 6,  7) }, -- ImGuiMouseCursor.NotAllowed
}

local MT = ImGui.GetMetatables()

-------------------------------------------------------------------------------
-- [SECTION] STB libraries implementation (for stb_truetype and stb_rect_pack)
-------------------------------------------------------------------------------

--- @module "imstb_rectpack"
local stbrp = IM_INCLUDE("imstb_rectpack.lua")

--- @module "imstb_truetype"
local stbtt = IM_INCLUDE("imstb_truetype.lua")

-------------------------------------------------------------------------------
-- [SECTION] Style functions
-------------------------------------------------------------------------------

--- @param a ImVec4
--- @param b ImVec4
--- @param t float
local function ImLerpV4V4F(a, b, t) return ImVec4(a.x + (b.x - a.x) * t, a.y + (b.y - a.y) * t, a.z + (b.z - a.z) * t, a.w + (b.w - a.w) * t) end

--- @param dst? ImGuiStyle
function ImGui.StyleColorsDark(dst)
    local style = dst and dst or ImGui.GetStyle()
    local colors = style.Colors

    colors[ImGuiCol.Text]                      = ImVec4(1.00, 1.00, 1.00, 1.00)
    colors[ImGuiCol.TextDisabled]              = ImVec4(0.50, 0.50, 0.50, 1.00)
    colors[ImGuiCol.WindowBg]                  = ImVec4(0.06, 0.06, 0.06, 0.94)
    colors[ImGuiCol.ChildBg]                   = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.PopupBg]                   = ImVec4(0.08, 0.08, 0.08, 0.94)
    colors[ImGuiCol.Border]                    = ImVec4(0.43, 0.43, 0.50, 0.50)
    colors[ImGuiCol.BorderShadow]              = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.FrameBg]                   = ImVec4(0.16, 0.29, 0.48, 0.54)
    colors[ImGuiCol.FrameBgHovered]            = ImVec4(0.26, 0.59, 0.98, 0.40)
    colors[ImGuiCol.FrameBgActive]             = ImVec4(0.26, 0.59, 0.98, 0.67)
    colors[ImGuiCol.TitleBg]                   = ImVec4(0.04, 0.04, 0.04, 1.00)
    colors[ImGuiCol.TitleBgActive]             = ImVec4(0.16, 0.29, 0.48, 1.00)
    colors[ImGuiCol.TitleBgCollapsed]          = ImVec4(0.00, 0.00, 0.00, 0.51)
    colors[ImGuiCol.MenuBarBg]                 = ImVec4(0.14, 0.14, 0.14, 1.00)
    colors[ImGuiCol.ScrollbarBg]               = ImVec4(0.02, 0.02, 0.02, 0.53)
    colors[ImGuiCol.ScrollbarGrab]             = ImVec4(0.31, 0.31, 0.31, 1.00)
    colors[ImGuiCol.ScrollbarGrabHovered]      = ImVec4(0.41, 0.41, 0.41, 1.00)
    colors[ImGuiCol.ScrollbarGrabActive]       = ImVec4(0.51, 0.51, 0.51, 1.00)
    colors[ImGuiCol.CheckMark]                 = ImVec4(0.26, 0.59, 0.98, 1.00)
    colors[ImGuiCol.CheckboxSelectedBg]        = ImLerpV4V4F(colors[ImGuiCol.FrameBg], colors[ImGuiCol.FrameBgHovered], 0.65)
    colors[ImGuiCol.SliderGrab]                = ImVec4(0.24, 0.52, 0.88, 1.00)
    colors[ImGuiCol.SliderGrabActive]          = ImVec4(0.26, 0.59, 0.98, 1.00)
    colors[ImGuiCol.Button]                    = ImVec4(0.26, 0.59, 0.98, 0.40)
    colors[ImGuiCol.ButtonHovered]             = ImVec4(0.26, 0.59, 0.98, 1.00)
    colors[ImGuiCol.ButtonActive]              = ImVec4(0.06, 0.53, 0.98, 1.00)
    colors[ImGuiCol.Header]                    = ImVec4(0.26, 0.59, 0.98, 0.31)
    colors[ImGuiCol.HeaderHovered]             = ImVec4(0.26, 0.59, 0.98, 0.80)
    colors[ImGuiCol.HeaderActive]              = ImVec4(0.26, 0.59, 0.98, 1.00)
    colors[ImGuiCol.Separator]                 = colors[ImGuiCol.Border]
    colors[ImGuiCol.SeparatorHovered]          = ImVec4(0.10, 0.40, 0.75, 0.78)
    colors[ImGuiCol.SeparatorActive]           = ImVec4(0.10, 0.40, 0.75, 1.00)
    colors[ImGuiCol.ResizeGrip]                = ImVec4(0.26, 0.59, 0.98, 0.20)
    colors[ImGuiCol.ResizeGripHovered]         = ImVec4(0.26, 0.59, 0.98, 0.67)
    colors[ImGuiCol.ResizeGripActive]          = ImVec4(0.26, 0.59, 0.98, 0.95)
    colors[ImGuiCol.InputTextCursor]           = colors[ImGuiCol.Text]
    colors[ImGuiCol.TabHovered]                = colors[ImGuiCol.HeaderHovered]
    colors[ImGuiCol.Tab]                       = ImLerpV4V4F(colors[ImGuiCol.Header],       colors[ImGuiCol.TitleBgActive], 0.80)
    colors[ImGuiCol.TabSelected]               = ImLerpV4V4F(colors[ImGuiCol.HeaderActive], colors[ImGuiCol.TitleBgActive], 0.60)
    colors[ImGuiCol.TabSelectedOverline]       = colors[ImGuiCol.HeaderActive]
    colors[ImGuiCol.TabDimmed]                 = ImLerpV4V4F(colors[ImGuiCol.Tab],          colors[ImGuiCol.TitleBg], 0.80)
    colors[ImGuiCol.TabDimmedSelected]         = ImLerpV4V4F(colors[ImGuiCol.TabSelected],  colors[ImGuiCol.TitleBg], 0.40)
    colors[ImGuiCol.TabDimmedSelectedOverline] = ImVec4(0.50, 0.50, 0.50, 0.00)
    colors[ImGuiCol.DockingPreview] = ImVec4(colors[ImGuiCol.HeaderActive].x, colors[ImGuiCol.HeaderActive].y, colors[ImGuiCol.HeaderActive].z, colors[ImGuiCol.HeaderActive].w * 0.7)
    colors[ImGuiCol.DockingEmptyBg] = ImVec4(0.20, 0.20, 0.20, 1.00)
    colors[ImGuiCol.PlotLines]                 = ImVec4(0.61, 0.61, 0.61, 1.00)
    colors[ImGuiCol.PlotLinesHovered]          = ImVec4(1.00, 0.43, 0.35, 1.00)
    colors[ImGuiCol.PlotHistogram]             = ImVec4(0.90, 0.70, 0.00, 1.00)
    colors[ImGuiCol.PlotHistogramHovered]      = ImVec4(1.00, 0.60, 0.00, 1.00)
    colors[ImGuiCol.TableHeaderBg]             = ImVec4(0.19, 0.19, 0.20, 1.00)
    colors[ImGuiCol.TableBorderStrong]         = ImVec4(0.31, 0.31, 0.35, 1.00)   -- Prefer using Alpha=1.0 here
    colors[ImGuiCol.TableBorderLight]          = ImVec4(0.23, 0.23, 0.25, 1.00)   -- Prefer using Alpha=1.0 here
    colors[ImGuiCol.TableRowBg]                = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.TableRowBgAlt]             = ImVec4(1.00, 1.00, 1.00, 0.06)
    colors[ImGuiCol.TextLink]                  = colors[ImGuiCol.HeaderActive]
    colors[ImGuiCol.TextSelectedBg]            = ImVec4(0.26, 0.59, 0.98, 0.35)
    colors[ImGuiCol.TreeLines]                 = colors[ImGuiCol.Border]
    colors[ImGuiCol.DragDropTarget]            = ImVec4(1.00, 1.00, 0.00, 0.90)
    colors[ImGuiCol.DragDropTargetBg]          = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.UnsavedMarker]             = ImVec4(1.00, 1.00, 1.00, 1.00)
    colors[ImGuiCol.NavCursor]                 = ImVec4(0.26, 0.59, 0.98, 1.00)
    colors[ImGuiCol.NavWindowingHighlight]     = ImVec4(1.00, 1.00, 1.00, 0.70)
    colors[ImGuiCol.NavWindowingDimBg]         = ImVec4(0.80, 0.80, 0.80, 0.20)
    colors[ImGuiCol.ModalWindowDimBg]          = ImVec4(0.80, 0.80, 0.80, 0.35)
end

--- @param dst? ImGuiStyle
function ImGui.StyleColorsClassic(dst)
    local style = dst and dst or ImGui.GetStyle()
    local colors = style.Colors

    colors[ImGuiCol.Text]                      = ImVec4(0.90, 0.90, 0.90, 1.00)
    colors[ImGuiCol.TextDisabled]              = ImVec4(0.60, 0.60, 0.60, 1.00)
    colors[ImGuiCol.WindowBg]                  = ImVec4(0.00, 0.00, 0.00, 0.85)
    colors[ImGuiCol.ChildBg]                   = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.PopupBg]                   = ImVec4(0.11, 0.11, 0.14, 0.92)
    colors[ImGuiCol.Border]                    = ImVec4(0.50, 0.50, 0.50, 0.50)
    colors[ImGuiCol.BorderShadow]              = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.FrameBg]                   = ImVec4(0.43, 0.43, 0.43, 0.39)
    colors[ImGuiCol.FrameBgHovered]            = ImVec4(0.47, 0.47, 0.69, 0.40)
    colors[ImGuiCol.FrameBgActive]             = ImVec4(0.42, 0.41, 0.64, 0.69)
    colors[ImGuiCol.TitleBg]                   = ImVec4(0.27, 0.27, 0.54, 0.83)
    colors[ImGuiCol.TitleBgActive]             = ImVec4(0.32, 0.32, 0.63, 0.87)
    colors[ImGuiCol.TitleBgCollapsed]          = ImVec4(0.40, 0.40, 0.80, 0.20)
    colors[ImGuiCol.MenuBarBg]                 = ImVec4(0.40, 0.40, 0.55, 0.80)
    colors[ImGuiCol.ScrollbarBg]               = ImVec4(0.20, 0.25, 0.30, 0.60)
    colors[ImGuiCol.ScrollbarGrab]             = ImVec4(0.40, 0.40, 0.80, 0.30)
    colors[ImGuiCol.ScrollbarGrabHovered]      = ImVec4(0.40, 0.40, 0.80, 0.40)
    colors[ImGuiCol.ScrollbarGrabActive]       = ImVec4(0.41, 0.39, 0.80, 0.60)
    colors[ImGuiCol.CheckMark]                 = ImVec4(0.90, 0.90, 0.90, 0.50)
    colors[ImGuiCol.CheckboxSelectedBg]        = ImLerpV4V4F(colors[ImGuiCol.FrameBg], colors[ImGuiCol.FrameBgActive], 0.65)
    colors[ImGuiCol.SliderGrab]                = ImVec4(1.00, 1.00, 1.00, 0.30)
    colors[ImGuiCol.SliderGrabActive]          = ImVec4(0.41, 0.39, 0.80, 0.60)
    colors[ImGuiCol.Button]                    = ImVec4(0.35, 0.40, 0.61, 0.62)
    colors[ImGuiCol.ButtonHovered]             = ImVec4(0.40, 0.48, 0.71, 0.79)
    colors[ImGuiCol.ButtonActive]              = ImVec4(0.46, 0.54, 0.80, 1.00)
    colors[ImGuiCol.Header]                    = ImVec4(0.40, 0.40, 0.90, 0.45)
    colors[ImGuiCol.HeaderHovered]             = ImVec4(0.45, 0.45, 0.90, 0.80)
    colors[ImGuiCol.HeaderActive]              = ImVec4(0.53, 0.53, 0.87, 0.80)
    colors[ImGuiCol.Separator]                 = ImVec4(0.50, 0.50, 0.50, 0.60)
    colors[ImGuiCol.SeparatorHovered]          = ImVec4(0.60, 0.60, 0.70, 1.00)
    colors[ImGuiCol.SeparatorActive]           = ImVec4(0.70, 0.70, 0.90, 1.00)
    colors[ImGuiCol.ResizeGrip]                = ImVec4(1.00, 1.00, 1.00, 0.10)
    colors[ImGuiCol.ResizeGripHovered]         = ImVec4(0.78, 0.82, 1.00, 0.60)
    colors[ImGuiCol.ResizeGripActive]          = ImVec4(0.78, 0.82, 1.00, 0.90)
    colors[ImGuiCol.InputTextCursor]           = colors[ImGuiCol.Text]
    colors[ImGuiCol.TabHovered]                = colors[ImGuiCol.HeaderHovered]
    colors[ImGuiCol.Tab]                       = ImLerpV4V4F(colors[ImGuiCol.Header],       colors[ImGuiCol.TitleBgActive], 0.80)
    colors[ImGuiCol.TabSelected]               = ImLerpV4V4F(colors[ImGuiCol.HeaderActive], colors[ImGuiCol.TitleBgActive], 0.60)
    colors[ImGuiCol.TabSelectedOverline]       = colors[ImGuiCol.HeaderActive]
    colors[ImGuiCol.TabDimmed]                 = ImLerpV4V4F(colors[ImGuiCol.Tab],          colors[ImGuiCol.TitleBg], 0.80)
    colors[ImGuiCol.TabDimmedSelected]         = ImLerpV4V4F(colors[ImGuiCol.TabSelected],  colors[ImGuiCol.TitleBg], 0.40)
    colors[ImGuiCol.TabDimmedSelectedOverline] = ImVec4(0.53, 0.53, 0.87, 0.00)
    colors[ImGuiCol.DockingPreview] = ImVec4(colors[ImGuiCol.Header].x, colors[ImGuiCol.Header].y, colors[ImGuiCol.Header].z, colors[ImGuiCol.Header].w * 0.7)
    colors[ImGuiCol.DockingEmptyBg] = ImVec4(0.20, 0.20, 0.20, 1.00)
    colors[ImGuiCol.PlotLines]                 = ImVec4(1.00, 1.00, 1.00, 1.00)
    colors[ImGuiCol.PlotLinesHovered]          = ImVec4(0.90, 0.70, 0.00, 1.00)
    colors[ImGuiCol.PlotHistogram]             = ImVec4(0.90, 0.70, 0.00, 1.00)
    colors[ImGuiCol.PlotHistogramHovered]      = ImVec4(1.00, 0.60, 0.00, 1.00)
    colors[ImGuiCol.TableHeaderBg]             = ImVec4(0.27, 0.27, 0.38, 1.00)
    colors[ImGuiCol.TableBorderStrong]         = ImVec4(0.31, 0.31, 0.45, 1.00)   -- Prefer using Alpha=1.0 here
    colors[ImGuiCol.TableBorderLight]          = ImVec4(0.26, 0.26, 0.28, 1.00)   -- Prefer using Alpha=1.0 here
    colors[ImGuiCol.TableRowBg]                = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.TableRowBgAlt]             = ImVec4(1.00, 1.00, 1.00, 0.07)
    colors[ImGuiCol.TextLink]                  = colors[ImGuiCol.HeaderActive]
    colors[ImGuiCol.TextSelectedBg]            = ImVec4(0.00, 0.00, 1.00, 0.35)
    colors[ImGuiCol.TreeLines]                 = colors[ImGuiCol.Border]
    colors[ImGuiCol.DragDropTarget]            = ImVec4(1.00, 1.00, 0.00, 0.90)
    colors[ImGuiCol.DragDropTargetBg]          = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.UnsavedMarker]             = ImVec4(0.90, 0.90, 0.90, 1.00)
    colors[ImGuiCol.NavCursor]                 = colors[ImGuiCol.HeaderHovered]
    colors[ImGuiCol.NavWindowingHighlight]     = ImVec4(1.00, 1.00, 1.00, 0.70)
    colors[ImGuiCol.NavWindowingDimBg]         = ImVec4(0.80, 0.80, 0.80, 0.20)
    colors[ImGuiCol.ModalWindowDimBg]          = ImVec4(0.20, 0.20, 0.20, 0.35)
end

-- Those light colors are better suited with a thicker font than the default one + FrameBorder
--- @param dst? ImGuiStyle
function ImGui.StyleColorsLight(dst)
    local style = dst and dst or ImGui.GetStyle()
    local colors = style.Colors

    colors[ImGuiCol.Text]                      = ImVec4(0.00, 0.00, 0.00, 1.00)
    colors[ImGuiCol.TextDisabled]              = ImVec4(0.60, 0.60, 0.60, 1.00)
    colors[ImGuiCol.WindowBg]                  = ImVec4(0.94, 0.94, 0.94, 1.00)
    colors[ImGuiCol.ChildBg]                   = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.PopupBg]                   = ImVec4(1.00, 1.00, 1.00, 0.98)
    colors[ImGuiCol.Border]                    = ImVec4(0.00, 0.00, 0.00, 0.30)
    colors[ImGuiCol.BorderShadow]              = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.FrameBg]                   = ImVec4(1.00, 1.00, 1.00, 1.00)
    colors[ImGuiCol.FrameBgHovered]            = ImVec4(0.26, 0.59, 0.98, 0.40)
    colors[ImGuiCol.FrameBgActive]             = ImVec4(0.26, 0.59, 0.98, 0.67)
    colors[ImGuiCol.TitleBg]                   = ImVec4(0.96, 0.96, 0.96, 1.00)
    colors[ImGuiCol.TitleBgActive]             = ImVec4(0.82, 0.82, 0.82, 1.00)
    colors[ImGuiCol.TitleBgCollapsed]          = ImVec4(1.00, 1.00, 1.00, 0.51)
    colors[ImGuiCol.MenuBarBg]                 = ImVec4(0.86, 0.86, 0.86, 1.00)
    colors[ImGuiCol.ScrollbarBg]               = ImVec4(0.98, 0.98, 0.98, 0.53)
    colors[ImGuiCol.ScrollbarGrab]             = ImVec4(0.69, 0.69, 0.69, 0.80)
    colors[ImGuiCol.ScrollbarGrabHovered]      = ImVec4(0.49, 0.49, 0.49, 0.80)
    colors[ImGuiCol.ScrollbarGrabActive]       = ImVec4(0.49, 0.49, 0.49, 1.00)
    colors[ImGuiCol.CheckMark]                 = ImVec4(0.26, 0.59, 0.98, 1.00)
    colors[ImGuiCol.CheckboxSelectedBg]        = ImVec4(0.95, 0.97, 1.00, 1.00)
    colors[ImGuiCol.SliderGrab]                = ImVec4(0.26, 0.59, 0.98, 0.78)
    colors[ImGuiCol.SliderGrabActive]          = ImVec4(0.46, 0.54, 0.80, 0.60)
    colors[ImGuiCol.Button]                    = ImVec4(0.26, 0.59, 0.98, 0.40)
    colors[ImGuiCol.ButtonHovered]             = ImVec4(0.26, 0.59, 0.98, 1.00)
    colors[ImGuiCol.ButtonActive]              = ImVec4(0.06, 0.53, 0.98, 1.00)
    colors[ImGuiCol.Header]                    = ImVec4(0.26, 0.59, 0.98, 0.31)
    colors[ImGuiCol.HeaderHovered]             = ImVec4(0.26, 0.59, 0.98, 0.80)
    colors[ImGuiCol.HeaderActive]              = ImVec4(0.26, 0.59, 0.98, 1.00)
    colors[ImGuiCol.Separator]                 = ImVec4(0.39, 0.39, 0.39, 0.62)
    colors[ImGuiCol.SeparatorHovered]          = ImVec4(0.14, 0.44, 0.80, 0.78)
    colors[ImGuiCol.SeparatorActive]           = ImVec4(0.14, 0.44, 0.80, 1.00)
    colors[ImGuiCol.ResizeGrip]                = ImVec4(0.35, 0.35, 0.35, 0.17)
    colors[ImGuiCol.ResizeGripHovered]         = ImVec4(0.26, 0.59, 0.98, 0.67)
    colors[ImGuiCol.ResizeGripActive]          = ImVec4(0.26, 0.59, 0.98, 0.95)
    colors[ImGuiCol.InputTextCursor]           = colors[ImGuiCol.Text]
    colors[ImGuiCol.TabHovered]                = colors[ImGuiCol.HeaderHovered]
    colors[ImGuiCol.Tab]                       = ImLerpV4V4F(colors[ImGuiCol.Header],       colors[ImGuiCol.TitleBgActive], 0.90)
    colors[ImGuiCol.TabSelected]               = ImLerpV4V4F(colors[ImGuiCol.HeaderActive], colors[ImGuiCol.TitleBgActive], 0.60)
    colors[ImGuiCol.TabSelectedOverline]       = colors[ImGuiCol.HeaderActive]
    colors[ImGuiCol.TabDimmed]                 = ImLerpV4V4F(colors[ImGuiCol.Tab],          colors[ImGuiCol.TitleBg], 0.80)
    colors[ImGuiCol.TabDimmedSelected]         = ImLerpV4V4F(colors[ImGuiCol.TabSelected],  colors[ImGuiCol.TitleBg], 0.40)
    colors[ImGuiCol.TabDimmedSelectedOverline] = ImVec4(0.26, 0.59, 1.00, 0.00)
    colors[ImGuiCol.DockingPreview] = ImVec4(colors[ImGuiCol.Header].x, colors[ImGuiCol.Header].y, colors[ImGuiCol.Header].z, colors[ImGuiCol.Header].w * 0.7)
    colors[ImGuiCol.DockingEmptyBg] = ImVec4(0.68, 0.69, 0.73, 1.00)
    colors[ImGuiCol.PlotLines]                 = ImVec4(0.39, 0.39, 0.39, 1.00)
    colors[ImGuiCol.PlotLinesHovered]          = ImVec4(1.00, 0.43, 0.35, 1.00)
    colors[ImGuiCol.PlotHistogram]             = ImVec4(0.90, 0.70, 0.00, 1.00)
    colors[ImGuiCol.PlotHistogramHovered]      = ImVec4(1.00, 0.45, 0.00, 1.00)
    colors[ImGuiCol.TableHeaderBg]             = ImVec4(0.78, 0.87, 0.98, 1.00)
    colors[ImGuiCol.TableBorderStrong]         = ImVec4(0.57, 0.57, 0.64, 1.00)   -- Prefer using Alpha=1.0 here
    colors[ImGuiCol.TableBorderLight]          = ImVec4(0.68, 0.68, 0.74, 1.00)   -- Prefer using Alpha=1.0 here
    colors[ImGuiCol.TableRowBg]                = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.TableRowBgAlt]             = ImVec4(0.30, 0.30, 0.30, 0.09)
    colors[ImGuiCol.TextLink]                  = colors[ImGuiCol.HeaderActive]
    colors[ImGuiCol.TextSelectedBg]            = ImVec4(0.26, 0.59, 0.98, 0.35)
    colors[ImGuiCol.TreeLines]                 = colors[ImGuiCol.Border]
    colors[ImGuiCol.DragDropTarget]            = ImVec4(0.26, 0.59, 0.98, 0.95)
    colors[ImGuiCol.DragDropTargetBg]          = ImVec4(0.00, 0.00, 0.00, 0.00)
    colors[ImGuiCol.UnsavedMarker]             = ImVec4(0.00, 0.00, 0.00, 1.00)
    colors[ImGuiCol.NavCursor]                 = colors[ImGuiCol.HeaderHovered]
    colors[ImGuiCol.NavWindowingHighlight]     = ImVec4(0.70, 0.70, 0.70, 0.70)
    colors[ImGuiCol.NavWindowingDimBg]         = ImVec4(0.20, 0.20, 0.20, 0.20)
    colors[ImGuiCol.ModalWindowDimBg]          = ImVec4(0.20, 0.20, 0.20, 0.35)
end

-------------------------------------------------------------------------------
-- [SECTION] Helpers ShadeVertsXXX functions
-------------------------------------------------------------------------------

-- Generic linear color gradient, write to RGB fields, leave A untouched.
--- @param draw_list      ImDrawList
--- @param vert_start_idx int
--- @param vert_end_idx   int
--- @param gradient_p0    ImVec2
--- @param gradient_p1    ImVec2
--- @param col0           ImU32
--- @param col1           ImU32
function ImGui.ShadeVertsLinearColorGradientKeepAlpha(draw_list, vert_start_idx, vert_end_idx, gradient_p0, gradient_p1, col0, col1)
    local gradient_extent = gradient_p1 - gradient_p0
    local gradient_inv_length2 = 1.0 / ImLengthSqr(gradient_extent)

    local col0_r = bit32.band(bit32.rshift(col0, IM_COL32_R_SHIFT), 0xFF)
    local col0_g = bit32.band(bit32.rshift(col0, IM_COL32_G_SHIFT), 0xFF)
    local col0_b = bit32.band(bit32.rshift(col0, IM_COL32_B_SHIFT), 0xFF)

    local col_delta_r = bit32.band(bit32.rshift(col1, IM_COL32_R_SHIFT), 0xFF) - col0_r
    local col_delta_g = bit32.band(bit32.rshift(col1, IM_COL32_G_SHIFT), 0xFF) - col0_g
    local col_delta_b = bit32.band(bit32.rshift(col1, IM_COL32_B_SHIFT), 0xFF) - col0_b

    for vert_idx = vert_start_idx, vert_end_idx - 1 do
        local vb = draw_list.VtxBuffer.Buf
        local o = (vert_idx - 1) * 36
        local d = (readf64(vb, o) - gradient_p0.x) * gradient_extent.x + (readf64(vb, o + 8) - gradient_p0.y) * gradient_extent.y
        local t = ImClamp(d * gradient_inv_length2, 0.0, 1.0)

        local r = math.floor(col0_r + col_delta_r * t)
        local g = math.floor(col0_g + col_delta_g * t)
        local b = math.floor(col0_b + col_delta_b * t)

        writeu32(vb, o + 32, bit32.bor(bit32.lshift(r, IM_COL32_R_SHIFT), bit32.lshift(g, IM_COL32_G_SHIFT), bit32.lshift(b, IM_COL32_B_SHIFT), bit32.band(readu32(vb, o + 32), IM_COL32_A_MASK)))
    end
end

-- Rotate and translate vertices [vert_start_idx, vert_end_idx) (1-based, like _VtxCurrentIdx)
function ImGui.ShadeVertsTransformPos(draw_list, vert_start_idx, vert_end_idx, pivot_in, cos_a, sin_a, pivot_out)
    local data = draw_list.VtxBuffer.Buf
    local pix, piy, pox, poy = pivot_in.x, pivot_in.y, pivot_out.x, pivot_out.y
    for i = vert_start_idx, vert_end_idx - 1 do
        local o = (i - 1) * 36
        local x, y = readf64(data, o) - pix, readf64(data, o + 8) - piy
        writef64(data, o, x * cos_a - y * sin_a + pox)
        writef64(data, o + 8, x * sin_a + y * cos_a + poy)
    end
end

-- Distribute UV over (a, b) rectangle
--- @param draw_list      ImDrawList
--- @param vert_start_idx int
--- @param vert_end_idx   int
--- @param a              ImVec2
--- @param b              ImVec2
--- @param uv_a           ImVec2
--- @param uv_b           ImVec2
--- @param clamp          bool
function ImGui.ShadeVertsLinearUV(draw_list, vert_start_idx, vert_end_idx, a, b, uv_a, uv_b, clamp)
    local size = b - a
    local uv_size = uv_b - uv_a
    local scale = ImVec2(
        (size.x ~= 0.0) and (uv_size.x / size.x) or 0.0,
        (size.y ~= 0.0) and (uv_size.y / size.y) or 0.0
    )

    local vertex
    local verts = draw_list.VtxBuffer.Buf
    if clamp then
        local min = ImMin(uv_a, uv_b)
        local max = ImMax(uv_a, uv_b)
        for vert_idx = vert_start_idx, vert_end_idx - 1 do
            local o = (vert_idx - 1) * 36
            local uv = ImClamp(uv_a + ImMul(ImVec2(readf64(verts, o), readf64(verts, o + 8)) - a, scale), min, max)
            writef64(verts, o + 16, uv.x); writef64(verts, o + 24, uv.y)
        end
    else
        for vert_idx = vert_start_idx, vert_end_idx - 1 do
            local o = (vert_idx - 1) * 36
            local uv = uv_a + ImMul(ImVec2(readf64(verts, o), readf64(verts, o + 8)) - a, scale)
            writef64(verts, o + 16, uv.x); writef64(verts, o + 24, uv.y)
        end
    end
end

--- Forward Declarations
local ImFontAtlasTextureAdd
local ImFontAtlasTextureGrow
local ImFontAtlasTextureGetSizeEstimate
local ImFontAtlasTextureBlockCopy
local ImFontAtlasTextureBlockConvert
local ImFontAtlasTextureBlockPostProcess
local ImFontAtlasTextureBlockPostProcessMultiply
local ImFontAtlasTextureBlockQueueUpload
local ImFontAtlasTextureCompact
local ImFontAtlasPackInit
local ImFontAtlasPackAddRect
local ImFontAtlasPackGetRect
local ImFontAtlasPackGetRectSafe
local ImFontAtlasBakedAdd
local ImFontAtlasBakedAddFontGlyph
local ImFontAtlasBakedAddFontGlyphAdvancedX
local ImFontAtlasBakedDiscard
local ImFontAtlasBakedGetOrAdd
local ImFontAtlasBakedGetId
local ImFontAtlasBakedGetClosestMatch
local ImFontAtlasBuildInit
local ImFontAtlasBuildSetTexture
local ImFontAtlasBuildUpdateTexDataLines
local ImFontAtlasBuildUpdateTexDataBasic
local ImFontAtlasBuildSetupFontLoader
local ImFontAtlasBuildSetupFontSpecialGlyphs
local ImFontAtlasBuildSetupFontBakedBlanks
local ImFontAtlasBuildSetupFontBakedEllipsis
local ImFontAtlasBuildSetupFontBakedFallback
local ImFontAtlasBuildDestroy
local ImFontAtlasBuildAcceptCodepointForSource
local ImFontAtlasBuildNotifySetFont
local ImFontAtlasBuildRenderBitmapFromString
local ImFontAtlasFontSourceInit
local ImFontAtlasFontSourceAddToFont
local ImFontAtlasFontDestroySourceData
local ImFontAtlasFontDestroyOutput

local ImFontBaked_BuildGrowIndex
local ImFontBaked_BuildLoadGlyph
local ImFontBaked_BuildLoadGlyphAdvanceX

local ImTextInitClassifiers
local ImTextClassifierGet
local ImTextClassifierClear
local ImTextClassifierSetCharClass
local ImTextClassifierSetCharClassFromStr

local ImTextureDataGetFormatBytesPerPixel

-------------------------------------------------------------------------------
-- [SECTION] ImFontAtlas, ImFontAtlasBuilder
-------------------------------------------------------------------------------
-- - Default texture data encoded in ASCII
-- - ImFontAtlas()
-- - ImFontAtlas:Clear()
-- - ImFontAtlas:ClearFonts()
-- - ImFontAtlas:ClearInputData()
-- - ImFontAtlas:ClearTexData()
-- - ImFontAtlas:CompactCache()
-- - ImFontAtlas:SetFontLoader()
-------------------------------------------------------------------------------
-- - ImFontAtlasUpdateNewFrame()
-- - ImFontAtlasTextureBlockConvert()
-- - ImFontAtlasTextureBlockPostProcess()
-- - ImFontAtlasTextureBlockPostProcessMultiply()
-- - ImFontAtlasTextureBlockFill()
-- - ImFontAtlasTextureBlockCopy()
-- - ImFontAtlasTextureBlockQueueUpload()
-------------------------------------------------------------------------------
-- - ImFontAtlas:GetTexDataAsAlpha8() [legacy]
-- - ImFontAtlas:GetTexDataAsRGBA32() [legacy]
-- - ImFontAtlas:Build() [legacy]
-------------------------------------------------------------------------------
-- - ImFontAtlas:AddFont()
-- - ImFontAtlas:AddFontDefault()
-- - ImFontAtlas:AddFontDefaultBitmap()
-- - ImFontAtlas:AddFontDefaultVector()
-- - ImFontAtlas:AddFontFromFileTTF()
-- - ImFontAtlas:AddFontFromMemoryTTF()
-- - ImFontAtlas:AddFontFromMemoryCompressedTTF()
-- - ImFontAtlas:AddFontFromMemoryCompressedBase85TTF()
-- - ImFontAtlas:RemoveFont()
-- - ImFontAtlasBuildNotifySetFont()
-------------------------------------------------------------------------------
-- - ImFontAtlas:AddCustomRect()
-- - ImFontAtlas:RemoveCustomRect()
-- - ImFontAtlas:GetCustomRect()
-- - ImFontAtlas:AddCustomRectFontGlyph() [legacy]
-- - ImFontAtlas:AddCustomRectFontGlyphForSize() [legacy]
-- - ImFontAtlasGetMouseCursorTexData()
-------------------------------------------------------------------------------
-- - ImFontAtlasBuildMain()
-- - ImFontAtlasBuildSetupFontLoader()
-- - ImFontAtlasBuildPreloadAllGlyphRanges()
-- - ImFontAtlasBuildUpdatePointers()
-- - ImFontAtlasBuildRenderBitmapFromString()
-- - ImFontAtlasBuildAddFont()
-- - ImFontAtlasBuildSetupFontBakedEllipsis()
-- - ImFontAtlasBuildSetupFontBakedBlanks()
-- - ImFontAtlasBuildSetupFontBakedFallback()
-- - ImFontAtlasBuildSetupFontSpecialGlyphs()
-- - ImFontAtlasBuildDiscardBakes()
-- - ImFontAtlasBuildDiscardFontBakedGlyph()
-- - ImFontAtlasBuildDiscardFontBaked()
-- - ImFontAtlasBuildDiscardFontBakes()
-------------------------------------------------------------------------------
-- - ImFontAtlasAddDrawListSharedData()
-- - ImFontAtlasRemoveDrawListSharedData()
-- - ImFontAtlasUpdateDrawListsTextures()
-- - ImFontAtlasUpdateDrawListsSharedData()
-------------------------------------------------------------------------------
-- - ImFontAtlasBuildSetTexture()
-- - ImFontAtlasBuildUpdateTexData()
-- - ImFontAtlasTextureAdd()
-- - ImFontAtlasTextureRepack()
-- - ImFontAtlasTextureGrow()
-- - ImFontAtlasTextureMakeSpace()
-- - ImFontAtlasTextureGetSizeEstimate()
-- - ImFontAtlasBuildClear()
-- - ImFontAtlasTextureCompact()
-- - ImFontAtlasBuildInit()
-- - ImFontAtlasBuildDestroy()
-------------------------------------------------------------------------------
-- - ImFontAtlasPackInit()
-- - ImFontAtlasPackAllocRectEntry()
-- - ImFontAtlasPackReuseRectEntry()
-- - ImFontAtlasPackDiscardRect()
-- - ImFontAtlasPackAddRect()
-- - ImFontAtlasPackGetRect()
-------------------------------------------------------------------------------
-- - ImFontBaked_BuildGrowIndex()
-- - ImFontBaked_BuildLoadGlyph()
-- - ImFontBaked_BuildLoadGlyphAdvanceX()
-- - ImFontAtlasDebugLogTextureRequests()
-------------------------------------------------------------------------------
-- - ImFontAtlasGetFontLoaderForStbTruetype()
-------------------------------------------------------------------------------

-- You probably should not call this directly. It is not well specified.
-- If you want to replace all your fonts mid-frame, most likely you should instead call ClearFonts() then load the new fonts.
-- Calling this mid-frame will discard the CPU-side copy of the texture data which is generally unreliable as you may have textures queued for creation or updates.
function MT.ImFontAtlas:Clear()
    IMGUI_DEBUG_LOG_FONT("[font] ImFontAtlas:Clear()")
    local backup_renderer_has_textures = self.RendererHasTextures
    self.RendererHasTextures = false -- Full Clear() is supported, but ClearTexData() only isn't.
    self:ClearFonts()
    self:ClearTexData()
    self.RendererHasTextures = backup_renderer_has_textures
end

function MT.ImFontAtlas:SetFontLoader(font_loader)
    ImFontAtlasBuildSetupFontLoader(self, font_loader)
end

function MT.ImFontAtlas:ClearInputData()
    IM_ASSERT(not self.Locked, "Cannot modify a locked ImFontAtlas!")

    for _, font in self.Fonts:iter() do
        ImFontAtlasFontDestroyOutput(self, font)
    end
    for _, font_cfg in self.Sources:iter() do
        ImFontAtlasFontDestroySourceData(self, font_cfg)
    end
    for _, font in self.Fonts:iter() do
        -- When clearing this we lose access to the font name and other information used to build the font.
        font.Sources:clear()
        font.Flags = bit32.bor(font.Flags, ImFontFlags.NoLoadGlyphs)
    end
    self.Sources:clear()
end

-- Clear CPU-side copy of the texture data.
function MT.ImFontAtlas:ClearTexData()
    IM_ASSERT(not self.Locked, "Cannot modify a locked ImFontAtlas!")
    IM_ASSERT(self.RendererHasTextures == false, "Not supported for dynamic atlases, but you may call Clear().")

    for _, tex in self.TexList:iter() do
        tex:DestroyPixels()
    end
    --self.Locked = true -- Hoped to be able to lock this down but some reload patterns may not be happy with it.
end

function MT.ImFontAtlas:CompactCache()
    ImFontAtlasTextureCompact(self)
end

function MT.ImFontAtlas:ClearFonts()
    -- FIXME-NEWATLAS: Illegal to remove currently bound font.
    IMGUI_DEBUG_LOG_FONT("[font] ImFontAtlas:ClearFonts()")
    IM_ASSERT(not self.Locked, "Cannot modify a locked ImFontAtlas!")

    for _, font in self.Fonts:iter() do
        ImFontAtlasBuildNotifySetFont(self, font, nil)
    end

    ImFontAtlasBuildDestroy(self)
    self:ClearInputData()
    self.Fonts:clear_delete()
    self.TexIsBuilt = false

    for _, shared_data in self.DrawListSharedDatas:iter() do
        if shared_data.FontAtlas == self then
            shared_data.Font = nil
            shared_data.FontSize = 0.0
            shared_data.FontScale = 0.0
        end
    end
end

--- @param tex ImTextureData
function ImTextureDataUpdateNewFrame(tex)
    local remove_from_list = false
    if tex.Status == ImTextureStatus.OK then
        tex.Updates:resize(0)
        tex.UpdateRect.x = 65535 tex.UpdateRect.y = 65535
        tex.UpdateRect.w = 0     tex.UpdateRect.h = 0
    end

    -- Request destroy
    -- - Keep bool to true in order to differentiate a planned destroy vs a destroy decided by the backend.
    -- - We don't destroy pixels right away, as backend may have an in-flight copy from RAM.
    if (tex.WantDestroyNextFrame and tex.Status ~= ImTextureStatus.Destroyed and tex.Status ~= ImTextureStatus.WantDestroy) then
        IM_ASSERT(tex.Status == ImTextureStatus.OK or tex.Status == ImTextureStatus.WantCreate or tex.Status == ImTextureStatus.WantUpdates)
        tex.Status = ImTextureStatus.WantDestroy
    end

    -- If a texture has never reached the backend, they don't need to know about it.
    -- (note: backends between 1.92.0 and 1.92.4 could set an already destroyed texture to ImTextureStatus.WantDestroy
    --  when invalidating graphics objects twice, which would previously remove it from the list and crash.)
    if (tex.Status == ImTextureStatus.WantDestroy and tex.TexID == ImTextureID_Invalid and tex.BackendUserData == nil and tex.QueueUserData == nil) then
        tex.Status = ImTextureStatus.Destroyed
    end

    -- Process texture being destroyed
    if (tex.Status == ImTextureStatus.Destroyed) then
        IM_ASSERT(tex.TexID == ImTextureID_Invalid and tex.BackendUserData == nil, "Backend set texture Status to Destroyed but did not clear TexID/BackendUserData!")
        IM_ASSERT(tex.QueueUserData == nil, "Texture queue set Status to Destroyed but did not clear QueueUserData!")
        if (tex.WantDestroyNextFrame) then
            remove_from_list = true -- Destroy was scheduled by us
        else
            tex.Status = ImTextureStatus.WantCreate -- Destroy was done was backend: recreate it (e.g. freed resources mid-run)
        end
    end

    -- The backend may need defer destroying by a few frames, to handle texture used by previous in-flight rendering.
    -- We allow the texture staying in _WantDestroy state and increment a counter which the backend can use to take its decision.
    if (tex.Status == ImTextureStatus.WantDestroy) then
        tex.UnusedFrames = tex.UnusedFrames + 1
    end

    return remove_from_list
end

-- Called by NewFrame() for atlases owned by a context.
-- If you manually manage font atlases, you'll need to call this yourself.
-- - 'frame_count' needs to be provided because we can gc/prioritize baked fonts based on their age.
-- - 'frame_count' may not match those of all imgui contexts using this atlas, as contexts may be updated as different frequencies. But generally you can use ImGui.GetFrameCount() on one of your context.
--- @param atlas                 ImFontAtlas
--- @param frame_count           int
--- @param renderer_has_textures any
function ImFontAtlasUpdateNewFrame(atlas, frame_count, renderer_has_textures)
    IM_ASSERT(atlas.Builder == nil or atlas.Builder.FrameCount < frame_count) -- Protection against being called twice.
    atlas.RendererHasTextures = renderer_has_textures

    -- Update texture status and discard old textures.
    -- (we do this first thing to handle an edge case: if user mistakenly calls ClearFonts()+SetStatus(OK) during
    --  rendering, it would ImFontAtlasBuildMain() rebuilding before tex.Updates[] gets a chance to be cleared)
    -- (if somehow we need to move this back lower in the function, we could manually call the code to clear Updates[]).
    local tex_n = 1
    while tex_n <= atlas.TexList.Size do
        -- Update and remove if requested
        local tex = atlas.TexList.Data[tex_n]

        if (tex.Status == ImTextureStatus.WantCreate and atlas.RendererHasTextures) then
            IM_ASSERT(tex.TexID == ImTextureID_Invalid and tex.BackendUserData == nil, "Backend set texture's TexID/BackendUserData but did not update Status to OK.")
        end

        local remove_from_list = ImTextureDataUpdateNewFrame(tex)

        if remove_from_list then
            IM_ASSERT(atlas.TexData ~= tex)
            tex:DestroyPixels()
            atlas.TexList:erase(tex_n)
            tex_n = tex_n - 1
        end

        tex_n = tex_n + 1
    end

    -- Check that font atlas was built or backend support texture reload in which case we can build now
    if (atlas.RendererHasTextures) then
        atlas.TexIsBuilt = true
        if (atlas.Builder == nil) then -- This will only happen if fonts were not already loaded.
            ImFontAtlasBuildMain(atlas)
        end
    end
    -- Legacy backend
    if (not atlas.RendererHasTextures) then
        IM_ASSERT_USER_ERROR(atlas.TexIsBuilt, "Backend does not support ImGuiBackendFlags.RendererHasTextures, and font atlas is not built! Update backend OR make sure you called ImGui_ImplXXXX_NewFrame() function for renderer backend, which should call io.Fonts->GetTexDataAsRGBA32() / GetTexDataAsAlpha8().")
    end
    if (atlas.TexIsBuilt and atlas.Builder.PreloadedAllGlyphsRanges) then
        IM_ASSERT_USER_ERROR(atlas.RendererHasTextures == false, "Called ImFontAtlas::Build() before ImGuiBackendFlags.RendererHasTextures got set! With new backends: you don't need to call Build().")
    end

    -- Clear BakedCurrent cache, this is important because it ensure the uncached path gets taken once.
    -- We also rely on ImFontBaked pointers never crossing frames.
    local builder = atlas.Builder
    builder.FrameCount = frame_count
    for _, font in atlas.Fonts:iter() do
        font.LastBaked = nil
    end

    -- Garbage collect BakedPool
    if builder.BakedDiscardedCount > 0 then
        local dst_n = 1

        for src_n = 1, builder.BakedPool.Size do
            repeat
            local p_src = builder.BakedPool.Data[src_n]
            if p_src.WantDestroy then
                break
            end

            local p_dst = builder.BakedPool.Data[dst_n]
            dst_n = dst_n + 1
            if p_dst == p_src then
                break
            end

            builder.BakedPool.Data[dst_n - 1] = p_src
            builder.BakedMap[p_src.BakedId] = p_src

            until true
        end

        IM_ASSERT(dst_n - 1 + builder.BakedDiscardedCount == builder.BakedPool.Size)

        builder.BakedPool.Size = builder.BakedPool.Size - builder.BakedDiscardedCount
        builder.BakedDiscardedCount = 0
    end
end

--- @param src_pixels      unsigned_char[]
--- @param src_fmt         ImTextureFormat
--- @param src_pitch       int
--- @param dst_pixels      unsigned_char[]
--- @param dst_pixels_base int
--- @param dst_fmt         ImTextureFormat
--- @param dst_pitch       int
--- @param w               int
--- @param h               int
function ImFontAtlasTextureBlockConvert(src_pixels, src_fmt, src_pitch, dst_pixels, dst_pixels_base, dst_fmt, dst_pitch, w, h)
    IM_ASSERT(src_pixels ~= nil and dst_pixels ~= nil)
    local src_pixels_base = 1
    if src_fmt == dst_fmt then
        local line_sz = w * ImTextureDataGetFormatBytesPerPixel(src_fmt)
        for ny = h, 1, -1 do
            ImStd.memmove(dst_pixels, dst_pixels_base, src_pixels, src_pixels_base, line_sz)

            src_pixels_base = src_pixels_base + src_pitch
            dst_pixels_base = dst_pixels_base + dst_pitch
        end
    elseif src_fmt == ImTextureFormat.Alpha8 and dst_fmt == ImTextureFormat.RGBA32 then
        for ny = h, 1, -1 do
            for nx = w, 1, -1 do
                local alpha = src_pixels[src_pixels_base + 0]
                src_pixels_base = src_pixels_base + 1

                write_u32(dst_pixels, dst_pixels_base, IM_COL32(255, 255, 255, alpha))
                dst_pixels_base = dst_pixels_base + 4
            end

            src_pixels_base = src_pixels_base + (src_pitch - w)
            dst_pixels_base = dst_pixels_base + (dst_pitch - w * 4)
        end
    elseif src_fmt == ImTextureFormat.RGBA32 and dst_fmt == ImTextureFormat.Alpha8 then
        for ny = h, 1, -1 do
            for nx = w, 1, -1 do
                local alpha = src_pixels[src_pixels_base + 3]
                src_pixels_base = src_pixels_base + 4

                dst_pixels[dst_pixels_base + 0] = alpha
                dst_pixels_base = dst_pixels_base + 1
            end

            src_pixels_base = src_pixels_base + (src_pitch - w * 4)
            dst_pixels_base = dst_pixels_base + (dst_pitch - w)
        end
    else
        IM_ASSERT(false)
    end
end

-- Source buffer may be written to (used for in-place mods).
-- Post-process hooks may eventually be added here.
--- @param data ImFontAtlasPostProcessData
function ImFontAtlasTextureBlockPostProcess(data)
    -- Multiply operator (legacy)
    if data.FontSrc.RasterizerMultiply ~= 1.0 then
        ImFontAtlasTextureBlockPostProcessMultiply(data, data.FontSrc.RasterizerMultiply)
    end
end

--- @param data            ImFontAtlasPostProcessData
--- @param multiply_factor float
function ImFontAtlasTextureBlockPostProcessMultiply(data, multiply_factor)
    local pixels, pixels_base = data.Pixels, data._PixelsBase
    local pitch = data.Pitch
    if data.Format == ImTextureFormat.Alpha8 then
        for ny = data.Height, 1, -1 do
            local p = pixels_base
            for nx = data.Width, 1, -1 do
                local v = ImMin(ImFloor(pixels[p + 0] * multiply_factor), 255)
                pixels[p + 0] = v

                p = p + 1
            end

            pixels_base = pixels_base + pitch
        end
    elseif data.Format == ImTextureFormat.RGBA32 then
        for ny = data.Height, 1, -1 do
            local p = pixels_base
            for nx = data.Width, 1, -1 do
                local a = ImMin(ImFloor(pixels[p + 3] * multiply_factor), 255)

                write_u32(pixels, p, IM_COL32(pixels[p + 0], pixels[p + 1], pixels[p + 2], a))

                p = p + 4
            end

            pixels_base = pixels_base + pitch
        end
    else
        IM_ASSERT(false)
    end
end

-- Copy block from one texture to another
--- @param src_tex ImTextureData
--- @param src_x   int
--- @param src_y   int
--- @param dst_tex ImTextureData
--- @param dst_x   int
--- @param dst_y   int
--- @param w       int
--- @param h       int
function ImFontAtlasTextureBlockCopy(src_tex, src_x, src_y, dst_tex, dst_x, dst_y, w, h)
    IM_ASSERT(src_tex.Pixels ~= nil and dst_tex.Pixels ~= nil)
    IM_ASSERT(src_tex.Format == dst_tex.Format)
    IM_ASSERT(src_x >= 0 and src_x + w <= src_tex.Width)
    IM_ASSERT(src_y >= 0 and src_y + h <= src_tex.Height)
    IM_ASSERT(dst_x >= 0 and dst_x + w <= dst_tex.Width)
    IM_ASSERT(dst_y >= 0 and dst_y + h <= dst_tex.Height)
    for y = 0, h - 1 do
        local dst, dst_base = dst_tex:GetPixelsAt(dst_x, dst_y + y)
        local src, src_base = src_tex:GetPixelsAt(src_x, src_y + y)
        ImStd.memmove(dst, dst_base, src, src_base, w * dst_tex.BytesPerPixel)
    end
end

-- Queue texture block update for renderer backend
--- @param tex   ImTextureData
--- @param x     int
--- @param y     int
--- @param w     int
--- @param h     int
local function ImTextureDataQueueUpload(tex, x, y, w, h)
    IM_ASSERT(tex.Status ~= ImTextureStatus.WantDestroy and tex.Status ~= ImTextureStatus.Destroyed)
    IM_ASSERT(x >= 0 and x <= 0xFFFF and y >= 0 and y <= 0xFFFF and w >= 0 and x + w <= 0x10000 and h >= 0 and y + h <= 0x10000)

    local req = ImTextureRect(x, y, w, h) -- (unsigned short)
    local new_x1 = ImMax(tex.UpdateRect.w == 0 and 0 or tex.UpdateRect.x + tex.UpdateRect.w, req.x + req.w)
    local new_y1 = ImMax(tex.UpdateRect.h == 0 and 0 or tex.UpdateRect.y + tex.UpdateRect.h, req.y + req.h)
    tex.UpdateRect.x = ImMin(tex.UpdateRect.x, req.x)
    tex.UpdateRect.y = ImMin(tex.UpdateRect.y, req.y)
    tex.UpdateRect.w = (new_x1 - tex.UpdateRect.x) -- (unsigned short)
    tex.UpdateRect.h = (new_y1 - tex.UpdateRect.y) -- (unsigned short)
    tex.UsedRect.x = ImMin(tex.UsedRect.x, req.x)
    tex.UsedRect.y = ImMin(tex.UsedRect.y, req.y)
    tex.UsedRect.w = (ImMax(tex.UsedRect.x + tex.UsedRect.w, req.x + req.w) - tex.UsedRect.x) -- (unsigned short)
    tex.UsedRect.h = (ImMax(tex.UsedRect.y + tex.UsedRect.h, req.y + req.h) - tex.UsedRect.y) -- (unsigned short)

    -- No need to queue if status is == ImTextureStatus.WantCreate
    if (tex.Status == ImTextureStatus.OK or tex.Status == ImTextureStatus.WantUpdates) then
        tex.Status = ImTextureStatus.WantUpdates
        tex.Updates:push_back(req)
    end
end

--- @param atlas ImFontAtlas
--- @param tex   ImTextureData
--- @param x     int
--- @param y     int
--- @param w     int
--- @param h     int
function ImFontAtlasTextureBlockQueueUpload(atlas, tex, x, y, w, h)
    ImTextureDataQueueUpload(tex, x, y, w, h)
    atlas.TexIsBuilt = false
end

-- Copy to texture, post-process and queue update for backend
--- @param atlas      ImFontAtlas
--- @param baked      ImFontBaked
--- @param src        ImFontConfig
--- @param glyph      ImFontGlyph
--- @param r          ImTextureRect
--- @param src_pixels unsigned_char[]
--- @param src_fmt    ImTextureFormat
--- @param src_pitch  int
local function ImFontAtlasBakedSetFontGlyphBitmap(atlas, baked, src, glyph, r, src_pixels, src_fmt, src_pitch)
    local tex = atlas.TexData
    IM_ASSERT(r.x + r.w <= tex.Width and r.y + r.h <= tex.Height)
    local out_p, out_p_base = tex:GetPixelsAt(r.x, r.y)
    IM_ASSERT(out_p ~= nil)
    ImFontAtlasTextureBlockConvert(src_pixels, src_fmt, src_pitch, out_p, out_p_base, tex.Format, tex:GetPitch(), r.w, r.h)
    local pp_data = ImFontAtlasPostProcessData(atlas, baked.OwnerFont, src, baked, glyph, out_p, out_p_base, tex.Format, tex:GetPitch(), r.w, r.h)
    ImFontAtlasTextureBlockPostProcess(pp_data)
    ImFontAtlasTextureBlockQueueUpload(atlas, tex, r.x, r.y, r.w, r.h)
end

local function ImFontAtlasBuildGetOversampleFactors(src, baked)
    -- (Only used by stb_truetype builder)
    -- Automatically disable horizontal oversampling over size 36
    local raster_size = baked.Size * baked.RasterizerDensity * src.RasterizerDensity
    local out_oversample_h
    if src.OversampleH ~= 0 then
        out_oversample_h = src.OversampleH
    elseif raster_size > 36.0 or src.PixelSnapH then
        out_oversample_h = 1
    else
        out_oversample_h = 2
    end
    local out_oversample_v = (src.OversampleV ~= 0) and src.OversampleV or 1
    return out_oversample_h, out_oversample_v
end

-- use unused_frames==0 to discard everything.
local function ImFontAtlasBuildDiscardBakes(atlas, unused_frames)
    local builder = atlas.Builder

    for baked_n = 1, builder.BakedPool.Size do
        repeat
        local baked = builder.BakedPool[baked_n]
        if (baked.LastUsedFrame + unused_frames > atlas.Builder.FrameCount) then
            break
        end

        if (baked.WantDestroy or (bit32.band(baked.OwnerFont.Flags, ImFontFlags.LockBakedSizes) ~= 0)) then
            break
        end

        ImFontAtlasBakedDiscard(atlas, baked.OwnerFont, baked)

        until true
    end
end

-- Those functions are designed to facilitate changing the underlying structures for ImFontAtlas to store an array of ImDrawListSharedData
--- @param atlas ImFontAtlas
--- @param data  ImDrawListSharedData
function ImFontAtlasAddDrawListSharedData(atlas, data)
    IM_ASSERT(not atlas.DrawListSharedDatas:contains(data))
    atlas.DrawListSharedDatas:push_back(data)
end

--- @param atlas ImFontAtlas
--- @param data  ImDrawListSharedData
function ImFontAtlasRemoveDrawListSharedData(atlas, data)
    IM_ASSERT(atlas.DrawListSharedDatas:contains(data))
    atlas.DrawListSharedDatas:find_erase(data)
end

--- @param atlas ImFontAtlas
--- @param w     int
--- @param h     int
local function ImFontAtlasTextureRepack(atlas, w, h)
    local builder = atlas.Builder
    builder.LockDisableResize = true

    local old_tex = atlas.TexData
    local new_tex = ImFontAtlasTextureAdd(atlas, w, h)
    new_tex.UseColors = old_tex.UseColors

    IMGUI_DEBUG_LOG_FONT("[font] Texture #%03d: resize+repack %dx%d => Texture #%03d: %dx%d", old_tex.UniqueID, old_tex.Width, old_tex.Height, new_tex.UniqueID, new_tex.Width, new_tex.Height)
    --for baked_n = 1, builder.BakedPool.Size do
    --    IMGUI_DEBUG_LOG_FONT("[font] - Baked %.2fpx, %d glyphs, want_destroy=%d", builder.BakedPool[baked_n].FontSize, builder.BakedPool[baked_n].Glyphs.Size, builder.BakedPool[baked_n].WantDestroy)
    --end
    --IMGUI_DEBUG_LOG_FONT("[font] - Old packed rects: %d, area %d px", builder.RectsPackedCount, builder.RectsPackedSurface)
    --ImFontAtlasDebugWriteTexToDisk(old_tex, "Before Pack")

    -- Repack, lose discarded rectangle, copy pixels
    -- FIXME-NEWATLAS: This is unstable because packing order is based on RectsIndex
    -- FIXME-NEWATLAS-V2: Repacking in batch would be beneficial to packing heuristic, and fix stability.
    -- FIXME-NEWATLAS-TESTS: Test calling RepackTexture with size too small to fits existing rects.
    ImFontAtlasPackInit(atlas)
    local old_rects = ImVector()
    local old_index = builder.RectsIndex:copy()
    old_rects:swap(builder.Rects)

    for _, index_entry in builder.RectsIndex:iter() do
        repeat
        if index_entry.IsUsed == false then
            break
        end

        local old_r = old_rects[index_entry.TargetIndex + 1]
        if (old_r.w == 0 and old_r.h == 0) then
            break
        end

        local new_r_id = ImFontAtlasPackAddRect(atlas, old_r.w, old_r.h, index_entry)
        if new_r_id == ImFontAtlasRectId_Invalid then
            -- Undo, grow texture and try repacking again.
            -- FIXME-NEWATLAS-TESTS: This is a very rarely exercised path! It needs to be automatically tested properly.
            IMGUI_DEBUG_LOG_FONT("[font] Texture #%03d: resize failed. Will grow.", new_tex.UniqueID)

            new_tex.WantDestroyNextFrame = true
            builder.Rects:swap(old_rects)
            builder.RectsIndex = old_index
            ImFontAtlasBuildSetTexture(atlas, old_tex)
            ImFontAtlasTextureGrow(atlas, w, h) -- Recurse

            return
        end

        IM_ASSERT(ImFontAtlasRectId_GetIndex(new_r_id) == builder.RectsIndex:index_from_ptr(index_entry))

        local new_r = ImFontAtlasPackGetRect(atlas, new_r_id)
        ImFontAtlasTextureBlockCopy(old_tex, old_r.x, old_r.y, new_tex, new_r.x, new_r.y, new_r.w, new_r.h)

        until true
    end
    IM_ASSERT(old_rects.Size == builder.Rects.Size + builder.RectsDiscardedCount)
    builder.RectsDiscardedCount = 0
    builder.RectsDiscardedSurface = 0

    -- Patch glyphs UV
    for baked_n = 1, builder.BakedPool.Size do
        for _, glyph in builder.BakedPool[baked_n].Glyphs:iter() do
            if (glyph.PackId ~= ImFontAtlasRectId_Invalid) then
                local r = ImFontAtlasPackGetRect(atlas, glyph.PackId)
                glyph.U0 = (r.x) * atlas.TexUvScale.x
                glyph.V0 = (r.y) * atlas.TexUvScale.y
                glyph.U1 = (r.x + r.w) * atlas.TexUvScale.x
                glyph.V1 = (r.y + r.h) * atlas.TexUvScale.y
            end
        end
    end

    -- Update other cached UV
    ImFontAtlasBuildUpdateTexData(atlas)

    builder.LockDisableResize = false
    ImFontAtlasUpdateDrawListsSharedData(atlas)
    --ImFontAtlasDebugWriteTexToDisk(new_tex, "After Pack")
end

function ImFontAtlasTextureGrow(atlas, old_tex_w, old_tex_h)
    --ImFontAtlasDebugWriteTexToDisk(atlas.TexData, "Before Grow")
    local builder = atlas.Builder

    old_tex_w = old_tex_w or -1
    old_tex_h = old_tex_h or -1

    if (old_tex_w == -1) then
        old_tex_w = atlas.TexData.Width
    end
    if (old_tex_h == -1) then
        old_tex_h = atlas.TexData.Height
    end

    -- FIXME-NEWATLAS-V2: What to do when reaching limits exposed by backend?
    -- FIXME-NEWATLAS-V2: Does ImFontAtlasFlags.NoPowerOfTwoHeight makes sense now? Allow 'lock' and 'compact' operations?
    IM_ASSERT(ImIsPowerOfTwo(old_tex_w) and ImIsPowerOfTwo(old_tex_h))
    IM_ASSERT(ImIsPowerOfTwo(atlas.TexMinWidth) and ImIsPowerOfTwo(atlas.TexMaxWidth) and ImIsPowerOfTwo(atlas.TexMinHeight) and ImIsPowerOfTwo(atlas.TexMaxHeight))

    -- Grow texture so it follows roughly a square.
    -- - Grow height before width, as width imply more packing nodes.
    -- - Caller should be taking account of RectsDiscardedSurface and may not need to grow.
    local new_tex_w = (old_tex_h <= old_tex_w) and old_tex_w or old_tex_w * 2
    local new_tex_h = (old_tex_h <= old_tex_w) and old_tex_h * 2 or old_tex_h

    -- Handle minimum size first (for pathologically large packed rects)
    local pack_padding = atlas.TexGlyphPadding
    new_tex_w = ImMax(new_tex_w, ImUpperPowerOfTwo(builder.MaxRectSize.x + pack_padding))
    new_tex_h = ImMax(new_tex_h, ImUpperPowerOfTwo(builder.MaxRectSize.y + pack_padding))
    new_tex_w = ImClamp(new_tex_w, atlas.TexMinWidth, atlas.TexMaxWidth)
    new_tex_h = ImClamp(new_tex_h, atlas.TexMinHeight, atlas.TexMaxHeight)
    if (new_tex_w == old_tex_w and new_tex_h == old_tex_h) then
        return
    end

    ImFontAtlasTextureRepack(atlas, new_tex_w, new_tex_h)
end

--- @param atlas ImFontAtlas
local function ImFontAtlasTextureMakeSpace(atlas)
    -- Can some baked contents be ditched?
    --IMGUI_DEBUG_LOG_FONT("[font] ImFontAtlasBuildMakeSpace()")
    local builder = atlas.Builder
    ImFontAtlasBuildDiscardBakes(atlas, 2)

    -- Currently using a heuristic for repack without growing.
    if (builder.RectsDiscardedSurface < builder.RectsPackedSurface * 0.20) then
        ImFontAtlasTextureGrow(atlas)
    else
        ImFontAtlasTextureRepack(atlas, atlas.TexData.Width, atlas.TexData.Height)
    end
end

-- This is essentially a free-list pattern, it may be nice to wrap it into a dedicated type.
--- @param atlas    ImFontAtlas
--- @param rect_idx ImFontAtlasRectId
local function ImFontAtlasPackAllocRectEntry(atlas, rect_idx)
    local builder = atlas.Builder
    local index_idx, index_entry
    if builder.RectsIndexFreeListStart < 0 then
        builder.RectsIndex:resize(builder.RectsIndex.Size + 1)
        index_idx = builder.RectsIndex.Size - 1
        index_entry = ImFontAtlasRectEntry()
        builder.RectsIndex.Data[builder.RectsIndex.Size] = index_entry
    else
        index_idx = builder.RectsIndexFreeListStart
        index_entry = builder.RectsIndex[index_idx + 1]
        IM_ASSERT(index_entry.IsUsed == false and index_entry.Generation > 0) -- Generation is incremented during DiscardRect
        builder.RectsIndexFreeListStart = index_entry.TargetIndex
    end

    index_entry.TargetIndex = rect_idx
    index_entry.IsUsed = true

    return ImFontAtlasRectId_Make(index_idx, index_entry.Generation)
end

-- Overwrite existing entry
--- @param atlas       ImFontAtlas
--- @param index_entry ImFontAtlasRectEntry
local function ImFontAtlasPackReuseRectEntry(atlas, index_entry)
    IM_ASSERT(index_entry.IsUsed)
    index_entry.TargetIndex = atlas.Builder.Rects.Size - 1
    local index_idx = atlas.Builder.RectsIndex:index_from_ptr(index_entry)
    return ImFontAtlasRectId_Make(index_idx, index_entry.Generation)
end

-- This is expected to be called in batches and followed by a repack
--- @param atlas ImFontAtlas
--- @param id    ImFontAtlasRectId
function ImFontAtlasPackDiscardRect(atlas, id)
    IM_ASSERT(id ~= ImFontAtlasRectId_Invalid)

    local rect = ImFontAtlasPackGetRect(atlas, id)
    if (rect == nil) then
        return
    end

    local builder = atlas.Builder
    local index_idx = ImFontAtlasRectId_GetIndex(id)
    local index_entry = builder.RectsIndex.Data[index_idx + 1]
    IM_ASSERT(index_entry.IsUsed and index_entry.TargetIndex >= 0)
    index_entry.IsUsed = false
    index_entry.TargetIndex = builder.RectsIndexFreeListStart
    index_entry.Generation = index_entry.Generation + 1
    if (index_entry.Generation == 0) then
        index_entry.Generation = index_entry.Generation + 1 -- Keep non-zero on overflow
    end

    local pack_padding = atlas.TexGlyphPadding
    builder.RectsIndexFreeListStart = index_idx
    builder.RectsDiscardedCount = builder.RectsDiscardedCount + 1
    builder.RectsDiscardedSurface = builder.RectsDiscardedSurface + ((rect.w + pack_padding) * (rect.h + pack_padding))
    rect.w = 0 rect.h = 0 -- Clear rectangle so it won't be packed again
end

-- Important: Calling this may recreate a new texture and therefore change atlas.TexData
-- FIXME-NEWFONTS: Expose other glyph padding settings for custom alteration (e.g. drop shadows). See #7962
function ImFontAtlasPackAddRect(atlas, w, h, overwrite_entry)
    IM_ASSERT(w > 0 and w <= 0xFFFF)
    IM_ASSERT(h > 0 and h <= 0xFFFF)

    local builder = atlas.Builder
    local pack_padding = atlas.TexGlyphPadding
    builder.MaxRectSize.x = ImMax(builder.MaxRectSize.x, w)
    builder.MaxRectSize.y = ImMax(builder.MaxRectSize.y, h)

    -- Pack
    local r = ImTextureRect(0, 0, w, h)
    for attempts_remaining = 3, 0, -1 do
        -- Try packing
        local pack_r = stbrp.rect()
        pack_r.w = w + pack_padding
        pack_r.h = h + pack_padding
        stbrp.pack_rects(builder.PackContext, {pack_r}, 1)
        r.x = pack_r.x -- (unsigned short)
        r.y = pack_r.y -- (unsigned short)
        if pack_r.was_packed == 1 then
            break
        end

        -- If we ran out of attempts, return fallback
        if (attempts_remaining == 0 or builder.LockDisableResize) then
            IMGUI_DEBUG_LOG_FONT("[font] Failed packing %dx%d rectangle. Returning fallback.", w, h)

            return ImFontAtlasRectId_Invalid
        end

        -- Resize or repack atlas! (this should be a rare event)
        ImFontAtlasTextureMakeSpace(atlas)
    end

    builder.MaxRectBounds.x = ImMax(builder.MaxRectBounds.x, r.x + r.w + pack_padding)
    builder.MaxRectBounds.y = ImMax(builder.MaxRectBounds.y, r.y + r.h + pack_padding)
    builder.RectsPackedCount = builder.RectsPackedCount + 1
    builder.RectsPackedSurface = builder.RectsPackedSurface + (w + pack_padding) * (h + pack_padding)

    builder.Rects:push_back(r)
    if (overwrite_entry ~= nil) then
        return ImFontAtlasPackReuseRectEntry(atlas, overwrite_entry) -- Write into an existing entry instead of adding one (used during repack)
    else
        return ImFontAtlasPackAllocRectEntry(atlas, builder.Rects.Size - 1)
    end
end

-- Generally for non-user facing functions: assert on invalid ID.
--- @param atlas ImFontAtlas
--- @param id    ImFontAtlasRectId
--- @return ImTextureRect
function ImFontAtlasPackGetRect(atlas, id)
    IM_ASSERT(id ~= ImFontAtlasRectId_Invalid)
    local index_idx = ImFontAtlasRectId_GetIndex(id)
    local builder = atlas.Builder
    local index_entry = builder.RectsIndex.Data[index_idx + 1]
    IM_ASSERT(index_entry.Generation == ImFontAtlasRectId_GetGeneration(id))
    IM_ASSERT(index_entry.IsUsed)
    --- @type ImTextureRect
    return builder.Rects.Data[index_entry.TargetIndex + 1]
end

-- For user-facing functions: return nil on invalid ID.
-- Important: return value is valid until next call to AddRect(), e.g. FindGlyph(), CalcTextSize() can all potentially invalidate previous rects.
--- @param atlas ImFontAtlas
--- @param id    ImFontAtlasRectId
function ImFontAtlasPackGetRectSafe(atlas, id)
    if id == ImFontAtlasRectId_Invalid then
        return nil
    end

    local index_idx = ImFontAtlasRectId_GetIndex(id)
    if atlas.Builder == nil then
        ImFontAtlasBuildInit(atlas)
    end
    local builder = atlas.Builder
    if index_idx >= builder.RectsIndex.Size then
        return nil
    end
    local index_entry = builder.RectsIndex.Data[index_idx + 1]
    if (index_entry.Generation ~= ImFontAtlasRectId_GetGeneration(id) or not index_entry.IsUsed) then
        return nil
    end
    return builder.Rects.Data[index_entry.TargetIndex + 1]
end

-- Important! This assume by ImFontConfig.GlyphExcludeRanges[] is a SMALL ARRAY (e.g. <10 entries)
-- Use "Input Glyphs Overlap Detection Tool" to display a list of glyphs provided by multiple sources in order to set this array up.
--- @param src       ImFontConfig
--- @param codepoint ImWchar
--- @return bool
function ImFontAtlasBuildAcceptCodepointForSource(src, codepoint)
    local exclude_list = src.GlyphExcludeRanges
    if exclude_list then
        local i = 1
        while exclude_list[i] ~= 0 do
            if codepoint >= exclude_list[i] and codepoint <= exclude_list[i + 1] then
                return false
            end

            i = i + 2
        end
    end

    return true
end

--- @param baked    ImFontBaked
--- @param new_size int
function ImFontBaked_BuildGrowIndex(baked, new_size)
    IM_ASSERT(baked.IndexAdvanceX.Size == baked.IndexLookup.Size)
    if (new_size <= baked.IndexLookup.Size) then
        return
    end
    baked.IndexAdvanceX:resize(new_size, -1.0)
    baked.IndexLookup:resize(new_size, IM_FONTGLYPH_INDEX_UNUSED)
end

-------------------------------------------------------------------------------
-- [SECTION] ImFontAtlas: backend for stb_truetype
-------------------------------------------------------------------------------
-- (imstb_truetype.lua in included near the top of this file)
-------------------------------------------------------------------------------

-- One for each ConfigData
--- @class ImGui_ImplStbTrueType_FontSrcData
--- @field FontInfo    stbtt_fontinfo
--- @field ScaleFactor float

--- @return ImGui_ImplStbTrueType_FontSrcData
--- @nodiscard
local function ImGui_ImplStbTrueType_FontSrcData()
    return {
        FontInfo    = stbtt.fontinfo(),
        ScaleFactor = nil
    }
end

-- Need this in Lua since I don't want to include 'stbrp' just for context constructor
-- in ImFontAtlasBuilder def code. The cpp code has 'stbrp_context_opaque' which I don't/can't have here
--- @param atlas ImFontAtlas
local function ImGui_ImplStbTrueType_LoaderInit(atlas)
    atlas.Builder.PackContext = atlas.Builder.PackContext or stbrp.context()
end

local function ImGui_ImplStbTrueType_FontSrcInit(atlas, src)
    -- IM_UNUSED(atlas)

    --- @type ImGui_ImplStbTrueType_FontSrcData?
    local bd_font_data = ImGui_ImplStbTrueType_FontSrcData()
    IM_ASSERT(src.FontLoaderData == nil)

    -- Initialize helper structure for font loading and verify that the TTF/OTF data is correct
    local font_offset = stbtt.GetFontOffsetForIndex(src.FontData, src.FontNo)
    if font_offset < 0 then
        bd_font_data = nil
        IM_ASSERT_USER_ERROR(0, "stbtt_GetFontOffsetForIndex(): FontData is incorrect, or FontNo cannot be found.")
        return false
    end
    if (not stbtt.InitFont(bd_font_data.FontInfo, src.FontData, font_offset)) then
        bd_font_data = nil
        IM_ASSERT_USER_ERROR(0, "stbtt_InitFont(): failed to parse FontData. It is correct and complete? Check FontDataSize.")
        return false
    end
    src.FontLoaderData = bd_font_data

    local ref_size = src.DstFont.Sources[1].SizePixels
    if (src.MergeMode and src.SizePixels == 0.0) then
        src.SizePixels = ref_size
    end

    bd_font_data.ScaleFactor = stbtt.ScaleForPixelHeight(bd_font_data.FontInfo, 1.0)
    if (src.MergeMode and src.SizePixels ~= 0.0 and ref_size ~= 0.0) then
        bd_font_data.ScaleFactor = bd_font_data.ScaleFactor * (src.SizePixels / ref_size) -- FIXME-NEWATLAS: Should tidy up that a bit
    end
    bd_font_data.ScaleFactor = bd_font_data.ScaleFactor * src.ExtraSizeScale

    return true
end

local function ImGui_ImplStbTrueType_FontSrcDestroy(atlas, src)
    -- IM_UNUSED(atlas)
    src.FontLoaderData = nil
end

local function ImGui_ImplStbTrueType_FontSrcContainsGlyph(atlas, src, codepoint)
    -- IM_UNUSED(atlas)
    local bd_font_data = src.FontLoaderData
    IM_ASSERT(bd_font_data ~= nil)

    local glyph_index = stbtt.FindGlyphIndex(bd_font_data.FontInfo, codepoint)
    return (glyph_index ~= 0)
end

local function ImGui_ImplStbTrueType_FontBakedInit(atlas, src, baked)
    -- IM_UNUSED(atlas)

    local bd_font_data = src.FontLoaderData
    if (src.MergeMode == false) then
        -- FIXME-NEWFONTS: reevaluate how to use sizing metrics
        -- FIXME-NEWFONTS: make use of line gap value
        local scale_for_layout = bd_font_data.ScaleFactor * baked.Size / src.ExtraSizeScale
        local unscaled_ascent, unscaled_descent, unscaled_line_gap = stbtt.GetFontVMetrics(bd_font_data.FontInfo)

        baked.Ascent = ImCeil(unscaled_ascent * scale_for_layout)
        baked.Descent = ImFloor(unscaled_descent * scale_for_layout)
        -- FIXME: round to rasterizer density? (#9348)
    end

    return true
end

--- @param atlas      ImFontAtlas
--- @param src        ImFontConfig
--- @param baked      ImFontBaked
--- @param _          any
--- @param codepoint  ImWchar
--- @param out_glyph  ImFontGlyph
--- @param advance_x? float
--- @return bool
--- @return float? out_advance_x # Updated `advance_x`
local function ImGui_ImplStbTrueType_FontBakedLoadGlyph(atlas, src, baked, _, codepoint, out_glyph, advance_x)
    -- Search for first font which has the glyph
    local bd_font_data = src.FontLoaderData
    IM_ASSERT(bd_font_data ~= nil)
    local glyph_index = stbtt.FindGlyphIndex(bd_font_data.FontInfo, codepoint)
    if (glyph_index == 0) then
        return false, advance_x
    end

    -- Fonts unit to pixels
    local oversample_h, oversample_v = ImFontAtlasBuildGetOversampleFactors(src, baked)
    local scale_for_layout = bd_font_data.ScaleFactor * baked.Size
    local rasterizer_density = src.RasterizerDensity * baked.RasterizerDensity
    local scale_for_raster_x = bd_font_data.ScaleFactor * baked.Size * rasterizer_density * oversample_h
    local scale_for_raster_y = bd_font_data.ScaleFactor * baked.Size * rasterizer_density * oversample_v

    -- Obtain size and advance
    local x0, y0, x1, y1 = stbtt.GetGlyphBitmapBoxSubpixel(bd_font_data.FontInfo, glyph_index, scale_for_raster_x, scale_for_raster_y, 0, 0)
    local advance, lsb = stbtt.GetGlyphHMetrics(bd_font_data.FontInfo, glyph_index)

    -- Load metrics only mode
    if (advance_x ~= nil) then
        IM_ASSERT(out_glyph == nil)
        advance_x = advance * scale_for_layout

        return true, advance_x
    end

    -- Prepare glyph
    out_glyph.Codepoint = codepoint
    out_glyph.AdvanceX = advance * scale_for_layout

    -- Pack and retrieve position inside texture atlas
    -- (generally based on stbtt_PackFontRangesRenderIntoRects)
    local is_visible = (x0 ~= x1 and y0 ~= y1)
    if is_visible then
        local w = (x1 - x0 + oversample_h - 1)
        local h = (y1 - y0 + oversample_v - 1)
        local pack_id = ImFontAtlasPackAddRect(atlas, w, h)
        if (pack_id == ImFontAtlasRectId_Invalid) then
            -- Pathological out of memory case (TexMaxWidth/TexMaxHeight set too small?)
            IM_ASSERT(pack_id ~= ImFontAtlasRectId_Invalid, "Out of texture memory.")
            return false, advance_x
        end

        local r = ImFontAtlasPackGetRect(atlas, pack_id)

        -- Render
        x0, y0, x1, y1 = stbtt.GetGlyphBitmapBox(bd_font_data.FontInfo, glyph_index, scale_for_raster_x, scale_for_raster_y)
        local builder = atlas.Builder
        builder.TempBuffer:resize(w * h * 1)
        local bitmap_pixels = builder.TempBuffer.Data
        ImStd.memset(bitmap_pixels, 0, w * h * 1)

        -- Render with oversampling
        -- (those functions conveniently assert if pixels are not cleared, which is another safety layer)
        local sub_x, sub_y = stbtt.MakeGlyphBitmapSubpixelPrefilter(bd_font_data.FontInfo, bitmap_pixels, w, h, w,
            scale_for_raster_x, scale_for_raster_y, 0, 0, oversample_h, oversample_v, glyph_index)

        local ref_size = baked.OwnerFont.Sources[1].SizePixels
        local offsets_scale = (ref_size ~= 0.0) and (baked.Size / ref_size) or 1.0
        local font_off_x = ImFloor(src.GlyphOffset.x * offsets_scale + 0.5) -- Snap scaled offset.
        local font_off_y = ImFloor(src.GlyphOffset.y * offsets_scale + 0.5)
        font_off_x = font_off_x + sub_x
        font_off_y = font_off_y + (sub_y + IM_ROUND(baked.Ascent))
        local recip_h = 1.0 / (oversample_h * rasterizer_density)
        local recip_v = 1.0 / (oversample_v * rasterizer_density)

        -- Register glyph
        -- r.x r.y are coordinates inside texture (in pixels)
        -- glyph.X0, glyph.Y0 are drawing coordinates from base text position, and accounting for oversampling.
        out_glyph.X0 = x0 * recip_h + font_off_x
        out_glyph.Y0 = y0 * recip_v + font_off_y
        out_glyph.X1 = (x0 + r.w) * recip_h + font_off_x
        out_glyph.Y1 = (y0 + r.h) * recip_v + font_off_y
        out_glyph.Visible = true
        out_glyph.PackId = pack_id

        ImFontAtlasBakedSetFontGlyphBitmap(atlas, baked, src, out_glyph, r, bitmap_pixels, ImTextureFormat.Alpha8, w)
    end

    return true, advance_x
end

local function ImFontAtlasGetFontLoaderForStbTruetype()
    local loader = ImFontLoader()

    loader.Name                 = "stb_truetype"
    loader.LoaderInit           = ImGui_ImplStbTrueType_LoaderInit
    loader.FontSrcInit          = ImGui_ImplStbTrueType_FontSrcInit
    loader.FontSrcDestroy       = ImGui_ImplStbTrueType_FontSrcDestroy
    loader.FontSrcContainsGlyph = ImGui_ImplStbTrueType_FontSrcContainsGlyph
    loader.FontBakedInit        = ImGui_ImplStbTrueType_FontBakedInit
    loader.FontBakedDestroy     = nil
    loader.FontBakedLoadGlyph   = ImGui_ImplStbTrueType_FontBakedLoadGlyph

    return loader
end

--- @param atlas ImFontAtlas
--- @param baked ImFontBaked
function ImFontAtlasBuildSetupFontBakedBlanks(atlas, baked)
    -- Mark space as always hidden (not strictly correct/necessary. but some e.g. icons fonts don't have a space. it tends to look neater in previews)
    local space_glyph = baked:FindGlyphNoFallback(32)
    if space_glyph ~= nil then
        space_glyph.Visible = false
    end

    -- Setup Tab character.
    -- FIXME: Needs proper TAB handling but it needs to be contextualized (or we could arbitrary say that each string starts at "column 0" ?)
    if baked:FindGlyphNoFallback(9) == nil and space_glyph ~= nil then
        local tab_glyph = ImFontGlyph()
        tab_glyph.Codepoint = 9
        tab_glyph.AdvanceX = space_glyph.AdvanceX * IM_TABSIZE
        ImFontAtlasBakedAddFontGlyph(atlas, baked, nil, tab_glyph)
    end
end

--- @param atlas                   ImFontAtlas
--- @param font                    ImFont
--- @param font_size               float
--- @param font_rasterizer_density float
--- @param baked_id                ImGuiID
--- @return ImFontBaked?
function ImFontAtlasBakedAdd(atlas, font, font_size, font_rasterizer_density, baked_id)
    IMGUI_DEBUG_LOG_FONT("[font] Created baked %.2fpx", font_size)

    local baked = atlas.Builder.BakedPool:push_back(ImFontBaked())

    baked.Size              = font_size
    baked.RasterizerDensity = font_rasterizer_density
    baked.BakedId           = baked_id
    baked.OwnerFont         = font
    baked.LastUsedFrame     = atlas.Builder.FrameCount

    -- Initialize backend data
    local loader_data_size = 0
    for _, src in font.Sources:iter() do -- Cannot easily be cached as we allow changing backend
        local loader = src.FontLoader and src.FontLoader or atlas.FontLoader
        loader_data_size = loader_data_size + loader.FontBakedSrcLoaderDataSize
    end
    -- baked.FontLoaderDatas = (loader_data_size > 0) and IM_ALLOC(loader_data_size) or nil
    -- local loader_data_p = baked->FontLoaderDatas
    for _, src in font.Sources:iter() do
        local loader = src.FontLoader and src.FontLoader or atlas.FontLoader
        if (loader.FontBakedInit) then
            loader.FontBakedInit(atlas, src, baked--[[, loader_data_p--]])
        end
        -- loader_data_p += loader->FontBakedSrcLoaderDataSize
    end

    ImFontAtlasBuildSetupFontBakedBlanks(atlas, baked)
    return baked
end

-- FIXME-OPT: This is not a fast query. Adding a BakedCount field in Font might allow to take a shortcut for the most common case.
--- @param atlas                   ImFontAtlas
--- @param font                    ImFont
--- @param font_size               float
--- @param font_rasterizer_density float
--- @return ImFontBaked?
function ImFontAtlasBakedGetClosestMatch(atlas, font, font_size, font_rasterizer_density)
    local builder = atlas.Builder

    for step_n = 0, 1 do
        local closest_larger_match
        local closest_smaller_match
        for baked_n = 1, builder.BakedPool.Size do
            repeat
            local baked = builder.BakedPool[baked_n]
            if (baked.OwnerFont ~= font or baked.WantDestroy) then
                break
            end

            if (step_n == 0 and baked.RasterizerDensity ~= font_rasterizer_density) then -- First try with same density
                break
            end

            if (baked.Size > font_size and (closest_larger_match == nil or baked.Size < closest_larger_match.Size)) then
                closest_larger_match = baked
            end
            if (baked.Size < font_size and (closest_smaller_match == nil or baked.Size > closest_smaller_match.Size)) then
                closest_smaller_match = baked
            end

            until true
        end
        if (closest_larger_match) then
            if (closest_smaller_match == nil or (closest_larger_match.Size >= font_size * 2.0 and closest_smaller_match.Size > font_size * 0.5)) then
                return closest_larger_match
            end
        end
        if (closest_smaller_match) then
            return closest_smaller_match
        end
    end

    return nil
end

--- @param atlas ImFontAtlas
--- @param font  ImFont
--- @param baked ImFontBaked
function ImFontAtlasBakedDiscard(atlas, font, baked)
    local builder = atlas.Builder

    for _, glyph in baked.Glyphs:iter() do
        if glyph.PackId ~= ImFontAtlasRectId_Invalid then
            ImFontAtlasPackDiscardRect(atlas, glyph.PackId)
        end
    end

    -- char* loader_data_p = (char*)baked->FontLoaderDatas
    for _, src in font.Sources:iter() do
        local loader = src.FontLoader and src.FontLoader or atlas.FontLoader
        if loader.FontBakedDestroy then
            loader.FontBakedDestroy(atlas, src, baked)
        end
    end

    if baked.FontLoaderDatas then
        baked.FontLoaderDatas = nil
    end

    builder.BakedMap[baked.BakedId] = nil
    builder.BakedDiscardedCount = builder.BakedDiscardedCount + 1
    baked:ClearOutputData()
    baked.WantDestroy = true
    font.LastBaked = nil
end

-- use unused_frames==0 to discard everything.
function ImFontAtlasFontDiscardBakes(atlas, font, unused_frames)
    local builder = atlas.Builder
    if builder then -- This can be called from font destructor
        for baked_n = 1, builder.BakedPool.Size do
            repeat
            local baked = builder.BakedPool[baked_n]
            if baked.LastUsedFrame + unused_frames > atlas.Builder.FrameCount then
                break
            end

            if (baked.OwnerFont ~= font) or baked.WantDestroy then
                break
            end

            ImFontAtlasBakedDiscard(atlas, font, baked)

            until true
        end
    end
end

-- Was tempted to lazily init FontSrc but wouldn't save much + makes it more complicated to detect invalid data at AddFont()
function ImFontAtlasFontInitOutput(atlas, font)
    local ret = true
    for _, src in font.Sources:iter() do
        if not ImFontAtlasFontSourceInit(atlas, src) then
            ret = false
        end
    end
    IM_ASSERT(ret) -- Unclear how to react to this meaningfully. Assume that result will be same as initial AddFont() call.
    return ret
end

-- Keep source/input FontData
function ImFontAtlasFontDestroyOutput(atlas, font)
    font:ClearOutputData()
    for _, src in font.Sources:iter() do
        local loader = src.FontLoader and src.FontLoader or atlas.FontLoader
        if loader and loader.FontSrcDestroy ~= nil then
            loader.FontSrcDestroy(atlas, src)
        end
    end
end

--- @param atlas ImFontAtlas
--- @param src ImFontConfig
--- @return boolean
function ImFontAtlasFontSourceInit(atlas, src)
    local loader = (src.FontLoader) and src.FontLoader or atlas.FontLoader
    if (loader.FontSrcInit ~= nil and not loader.FontSrcInit(atlas, src)) then
        return false
    end
    return true
end

--- @param atlas ImFontAtlas
--- @param font ImFont
--- @param src ImFontConfig
function ImFontAtlasFontSourceAddToFont(atlas, font, src)
    if src.MergeMode == false then
        font:ClearOutputData()
        --font.FontSize = src.SizePixels
        font.OwnerAtlas = atlas
        IM_ASSERT(font.Sources[1] == src)
    end
    atlas.TexIsBuilt = false -- For legacy backends
    ImFontAtlasBuildSetupFontSpecialGlyphs(atlas, font, src)
end

--- @param atlas ImFontAtlas
--- @param src ImFontConfig
function ImFontAtlasFontDestroySourceData(atlas, src)
    -- IM_UNUSED(atlas)

    -- if src.FontDataOwnedByAtlas then
    --     IM_FREE(src.FontData)
    -- end
    src.FontData = nil
    -- if src.GlyphExcludeRanges then
    --     IM_FREE(src.GlyphExcludeRanges)
    -- end
    src.GlyphExcludeRanges = nil
end

-- Load/identify special glyphs
-- (note that this is called again for fonts with MergeMode)
--- @param atlas ImFontAtlas
--- @param font ImFont
--- @param src ImFontConfig
function ImFontAtlasBuildSetupFontSpecialGlyphs(atlas, font, src)
    -- IM_UNUSED(atlas)
    IM_ASSERT(font.Sources:contains(src))

    -- Find Fallback character. Actual glyph loaded in GetFontBaked().
    --- @type ImWchar[]
    local fallback_chars = {font.FallbackChar, IM_UNICODE_CODEPOINT_INVALID, 63, 32}
    if font.FallbackChar == 0 then
        for _, candidate_char in ipairs(fallback_chars) do
            if candidate_char ~= 0 and font:IsGlyphInFont(candidate_char) then
                font.FallbackChar = candidate_char

                break
            end
        end
    end

    -- Setup Ellipsis character. It is required for rendering elided text. We prefer using U+2026 (horizontal ellipsis).
    -- However some old fonts may contain ellipsis at U+0085. Here we auto-detect most suitable ellipsis character.
    -- FIXME: Note that 0x2026 is rarely included in our font ranges. Because of this we are more likely to use three individual dots.
    --- @type ImWchar[]
    local ellipsis_chars = {src.EllipsisChar, 0x2026, 0x0085}
    if font.EllipsisChar == 0 then
        for _, candidate_char in ipairs(ellipsis_chars) do
            if candidate_char ~= 0 and font:IsGlyphInFont(candidate_char) then
                font.EllipsisChar = candidate_char

                break
            end
        end
    end

    if font.EllipsisChar == 0 then
        font.EllipsisChar = 0x0085
        font.EllipsisAutoBake = true
    end
end

-- Create a compact, baked "..." if it doesn't exist, by using the ".".
-- This may seem overly complicated right now but the point is to exercise and improve a technique which should be increasingly used.
-- FIXME-NEWATLAS: This borrows too much from FontLoader's FontLoadGlyph() handlers and suggest that we should add further helpers.
--- @param atlas ImFontAtlas
--- @param baked ImFontBaked
--- @return ImFontGlyph?
function ImFontAtlasBuildSetupFontBakedEllipsis(atlas, baked)
    local font = baked.OwnerFont
    IM_ASSERT(font.EllipsisChar ~= 0)

    local dot_glyph = baked:FindGlyphNoFallback(46) -- '.'
    if (dot_glyph == nil) then
        dot_glyph = baked:FindGlyphNoFallback(0xFF0E)
    end
    if (dot_glyph == nil) then
        return nil
    end
    local dot_r_id = dot_glyph.PackId -- Deep copy to avoid invalidation of glyphs and rect pointers
    local dot_r = ImFontAtlasPackGetRect(atlas, dot_r_id)
    local dot_spacing = 1
    local dot_step = (dot_glyph.X1 - dot_glyph.X0) + dot_spacing

    local pack_id = ImFontAtlasPackAddRect(atlas, (dot_r.w * 3 + dot_spacing * 2), dot_r.h)
    local r = ImFontAtlasPackGetRect(atlas, pack_id)

    local glyph = ImFontGlyph()
    glyph.Codepoint = font.EllipsisChar
    glyph.AdvanceX = ImMax(dot_glyph.AdvanceX, dot_glyph.X0 + dot_step * 3.0 - dot_spacing) -- FIXME: Slightly odd for normally mono-space fonts but since this is used for trailing contents.
    glyph.X0 = dot_glyph.X0
    glyph.Y0 = dot_glyph.Y0
    glyph.X1 = dot_glyph.X0 + dot_step * 3 - dot_spacing
    glyph.Y1 = dot_glyph.Y1
    glyph.Visible = true
    glyph.PackId = pack_id
    glyph = ImFontAtlasBakedAddFontGlyph(atlas, baked, nil, glyph)
    dot_glyph = nil

    dot_r = ImFontAtlasPackGetRect(atlas, dot_r_id)
    local tex = atlas.TexData
    for n = 0, 2 do
        ImFontAtlasTextureBlockCopy(tex, dot_r.x, dot_r.y, tex, r.x + (dot_r.w + dot_spacing) * n, r.y, dot_r.w, dot_r.h)
    end
    ImFontAtlasTextureBlockQueueUpload(atlas, tex, r.x, r.y, r.w, r.h)

    return glyph
end

-- Load fallback in order to obtain its index
-- (this is called from in hot-path so we avoid extraneous parameters to minimize impact on code size)
--- @param baked ImFontBaked
function ImFontAtlasBuildSetupFontBakedFallback(baked)
    IM_ASSERT(baked.FallbackGlyphIndex == -1)
    IM_ASSERT(baked.FallbackAdvanceX == 0.0)
    local font = baked.OwnerFont
    local fallback_glyph
    if (font.FallbackChar ~= 0) then
        fallback_glyph = baked:FindGlyphNoFallback(font.FallbackChar)
    end
    if (fallback_glyph == nil) then
        local space_glyph = baked:FindGlyphNoFallback(32) -- ' '
        local glyph = ImFontGlyph()
        glyph.Codepoint = 0
        glyph.AdvanceX = space_glyph and space_glyph.AdvanceX or IM_ROUND(baked.Size * 0.40)
        fallback_glyph = ImFontAtlasBakedAddFontGlyph(font.OwnerAtlas, baked, nil, glyph)
    end
    baked.FallbackGlyphIndex = baked.Glyphs:index_from_ptr(fallback_glyph) + 1 -- Storing index avoid need to update pointer on growth and simplify inner loop code
    baked.FallbackAdvanceX = fallback_glyph.AdvanceX
end

-- Setup main font loader for the atlas
-- Every font source (ImFontConfig) will use this unless ImFontConfig.FontLoader specify a custom loader.
function ImFontAtlasBuildSetupFontLoader(atlas, font_loader)
    if atlas.FontLoader == font_loader then
        return
    end
    IM_ASSERT(not atlas.Locked, "Cannot modify a locked ImFontAtlas!")

    for _, font in atlas.Fonts:iter() do
        ImFontAtlasFontDestroyOutput(atlas, font)
    end
    if atlas.Builder and atlas.FontLoader and atlas.FontLoader.LoaderShutdown then
        atlas.FontLoader.LoaderShutdown(atlas)
    end

    atlas.FontLoader = font_loader
    atlas.FontLoaderName = font_loader and font_loader.Name or "NULL"
    IM_ASSERT(atlas.FontLoaderData == nil)

    if atlas.Builder and atlas.FontLoader and atlas.FontLoader.LoaderInit then
        atlas.FontLoader.LoaderInit(atlas)
    end
    for _, font in atlas.Fonts:iter() do
        ImFontAtlasFontInitOutput(atlas, font)
    end
    for _, font in atlas.Fonts:iter() do
        for _, src in font.Sources:iter() do
            ImFontAtlasFontSourceAddToFont(atlas, font, src)
        end
    end
end

local function ImFontAtlasBuildUpdateRendererHasTexturesFromContext(atlas)
    -- [LEGACY] Copy back the ImGuiBackendFlags.RendererHasTextures flag from ImGui context.
    -- - This is the 1% exceptional case where that dependency if useful, to bypass an issue where otherwise at the
    --   time of an early call to Build(), it would be impossible for us to tell if the backend supports texture update.
    -- - Without this hack, we would have quite a pitfall as many legacy codebases have an early call to Build().
    --   Whereas conversely, the portion of people using ImDrawList without ImGui is expected to be pathologically rare.
    for _, shared_data in atlas.DrawListSharedDatas:iter() do
        local imgui_ctx = shared_data.Context
        if (imgui_ctx) then
            atlas.RendererHasTextures = bit32.band(imgui_ctx.IO.BackendFlags, ImGuiBackendFlags.RendererHasTextures) ~= 0

            break
        end
    end
end

local function ImFontAtlasBuildUpdatePointers(atlas)
    -- for _, font in atlas.Fonts:iter() do
    --     font.Sources:resize(0)
    -- end
    -- for _, src in atlas.Sources:iter() do
    --     src.DstFont.Sources:push_back(src)
    -- end
end

-- Update texture identifier in all active draw lists
--- @param atlas   ImFontAtlas
--- @param old_tex ImTextureRef
--- @param new_tex ImTextureRef
local function ImFontAtlasUpdateDrawListsTextures(atlas, old_tex, new_tex)
    for _, shared_data in atlas.DrawListSharedDatas:iter() do
        repeat
        -- If Context 2 uses font owned by Context 1 which already called EndFrame()/Render(), we don't want to mess with draw commands for Context 1
        if (shared_data.Context and not shared_data.Context.WithinFrameScope) then
            break
        end

        for _, draw_list in shared_data.DrawLists:iter() do
            -- Replace in command-buffer
            -- (there is not need to replace in ImDrawListSplitter: current channel is in ImDrawList's CmdBuffer[],
            --  other channels will be on SetCurrentChannel() which already needs to compare CmdHeader anyhow)
            if (draw_list.CmdBuffer.Size > 0 and draw_list._CmdHeader.TexRef == old_tex) then
                draw_list:_SetTexture(new_tex)
            end

            -- Replace in stack
            for i, stacked_tex in draw_list._TextureStack:iter() do
                if (stacked_tex == old_tex) then
                    draw_list._TextureStack.Data[i] = new_tex
                end
            end
        end

        until true
    end
end

-- Set current texture. This is mostly called from AddTexture() + to handle a failed resize.
function ImFontAtlasBuildSetTexture(atlas, tex)
    local old_tex_ref = atlas.TexRef
    atlas.TexData = tex
    atlas.TexUvScale = ImVec2(1.0 / tex.Width, 1.0 / tex.Height)
    atlas.TexRef._TexData = tex
    --atlas.TexRef._TexID = tex.TexID -- <-- We intentionally don't do that. It would be misleading and betray promise that both fields aren't set.
    ImFontAtlasUpdateDrawListsTextures(atlas, old_tex_ref, atlas.TexRef)
end

--- @param atlas ImFontAtlas
function ImFontAtlasBuildUpdateTexData(atlas)
    ImFontAtlasBuildUpdateTexDataLines(atlas)
    ImFontAtlasBuildUpdateTexDataBasic(atlas)
end

-- Create a new texture, discard previous one
function ImFontAtlasTextureAdd(atlas, w, h)
    local old_tex = atlas.TexData
    local new_tex

    -- FIXME: Cannot reuse texture because old UV may have been used already (unless we remap UV).
    --if (old_tex ~= nil and old_tex.Status == ImTextureStatus.WantCreate) then
    --    -- Reuse texture not yet used by backend.
    --    IM_ASSERT(old_tex.TexID == ImTextureID_Invalid and old_tex.BackendUserData == nil)
    --    old_tex:DestroyPixels()
    --    old_tex.Updates:clear()
    --    new_tex = old_tex
    --    old_tex = nil
    --else
    -- Add new
    new_tex = ImTextureData()
    new_tex.UniqueID = atlas.TexNextUniqueID
    atlas.TexNextUniqueID = atlas.TexNextUniqueID + 1
    atlas.TexList:push_back(new_tex)

    if old_tex ~= nil then
        -- Queue old as to destroy next frame
        old_tex.WantDestroyNextFrame = true
        IM_ASSERT(old_tex.Status == ImTextureStatus.OK or old_tex.Status == ImTextureStatus.WantCreate or old_tex.Status == ImTextureStatus.WantUpdates)
    end

    new_tex:Create(atlas.TexDesiredFormat, w, h)
    atlas.TexIsBuilt = false

    ImFontAtlasBuildSetTexture(atlas, new_tex)

    return new_tex
end

--- @param atlas ImFontAtlas
--- @return ImVec2
function ImFontAtlasTextureGetSizeEstimate(atlas)
    local min_w = ImUpperPowerOfTwo(atlas.TexMinWidth)
    local min_h = ImUpperPowerOfTwo(atlas.TexMinHeight)
    if (atlas.Builder == nil or atlas.TexData == nil or atlas.TexData.Status == ImTextureStatus.WantDestroy) then
        return ImVec2(min_w, min_h) -- ImVec2i
    end

    local builder = atlas.Builder
    min_w = ImMax(ImUpperPowerOfTwo(builder.MaxRectSize.x), min_w)
    min_h = ImMax(ImUpperPowerOfTwo(builder.MaxRectSize.y), min_h)
    local surface_approx = builder.RectsPackedSurface - builder.RectsDiscardedSurface -- Expected surface after repack
    local surface_sqrt = ImFloor(ImSqrt(surface_approx))

    local new_tex_w
    local new_tex_h
    if (min_w >= min_h) then
        new_tex_w = ImMax(min_w, ImUpperPowerOfTwo(surface_sqrt))
        new_tex_h = ImMax(min_h, ImFloor((surface_approx + new_tex_w - 1) / new_tex_w))
        if (bit32.band(atlas.Flags, ImFontAtlasFlags.NoPowerOfTwoHeight) == 0) then
            new_tex_h = ImUpperPowerOfTwo(new_tex_h)
        end
    else
        new_tex_h = ImMax(min_h, ImUpperPowerOfTwo(surface_sqrt))
        if (bit32.band(atlas.Flags, ImFontAtlasFlags.NoPowerOfTwoHeight) == 0) then
            new_tex_h = ImUpperPowerOfTwo(new_tex_h)
        end
        new_tex_w = ImMax(min_w, ImFloor((surface_approx + new_tex_h - 1) / new_tex_h))
    end

    IM_ASSERT(ImIsPowerOfTwo(new_tex_w) and ImIsPowerOfTwo(new_tex_h))
    return ImVec2(new_tex_w, new_tex_h) -- ImVec2i
end

-- Clear all output. Invalidates all AddCustomRect() return values!
--- @param atlas ImFontAtlas
function ImFontAtlasBuildClear(atlas)
    local new_tex_size = ImFontAtlasTextureGetSizeEstimate(atlas) -- ImVec2i
    ImFontAtlasBuildDestroy(atlas)
    ImFontAtlasTextureAdd(atlas, new_tex_size.x, new_tex_size.y)
    ImFontAtlasBuildInit(atlas)
    for _, src in atlas.Sources:iter() do
        ImFontAtlasFontSourceInit(atlas, src)
    end
    for _, font in atlas.Fonts:iter() do
        for _, src in font.Sources:iter() do
            ImFontAtlasFontSourceAddToFont(atlas, font, src)
        end
    end
end

-- You should not need to call this manually!
-- If you think you do, let us know and we can advise about policies auto-compact.
--- @param atlas ImFontAtlas
function ImFontAtlasTextureCompact(atlas)
    local builder = atlas.Builder
    ImFontAtlasBuildDiscardBakes(atlas, 1)

    local old_tex = atlas.TexData
    local old_tex_size = ImVec2(old_tex.Width, old_tex.Height)
    local new_tex_size = ImFontAtlasTextureGetSizeEstimate(atlas)
    if (builder.RectsDiscardedCount == 0 and new_tex_size.x == old_tex_size.x and new_tex_size.y == old_tex_size.y) then
        return
    end

    ImFontAtlasTextureRepack(atlas, new_tex_size.x, new_tex_size.y)
end

--- @param atlas ImFontAtlas
function ImFontAtlasPackInit(atlas)
    local tex = atlas.TexData
    local builder = atlas.Builder

    -- In theory we could decide to reduce the number of nodes, e.g. halve them, and waste a little texture space, but it doesn't seem worth it.
    local pack_node_count = ImFloor(tex.Width / 2)
    builder.PackNodes:resize(pack_node_count)
    for i = 1, builder.PackNodes.Size do builder.PackNodes.Data[i] = stbrp.node() end

    stbrp.init_target(builder.PackContext, tex.Width, tex.Height, builder.PackNodes.Data, builder.PackNodes.Size)
    builder.RectsPackedCount = 0
    builder.RectsPackedSurface = 0
    builder.MaxRectSize = ImVec2(0, 0) -- ImVec2i
    builder.MaxRectBounds = ImVec2(0, 0) -- ImVec2i
end

--- @param atlas ImFontAtlas
function ImFontAtlasBuildUpdateTexDataLines(atlas)
    if bit32.band(atlas.Flags, ImFontAtlasFlags.NoBakedLines) ~= 0 then
        return
    end

    -- Pack and store identifier so we can refresh UV coordinates on texture resize.
    local tex = atlas.TexData
    local builder = atlas.Builder

    local r = ImFontAtlasRect()
    local add_and_draw = (atlas:GetCustomRect(builder.PackIdLinesTexData, r) == false)
    if add_and_draw then
        -- Register texture region for thick lines
        -- The +2 here is to give space for the end caps, whilst height +1 is to accommodate the fact we have a zero-width row
        local pack_size = ImVec2(IM_DRAWLIST_TEX_LINES_WIDTH_MAX + 2, IM_DRAWLIST_TEX_LINES_WIDTH_MAX + 1) -- ImVec2i
        builder.PackIdLinesTexData = atlas:AddCustomRect(pack_size.x, pack_size.y, r)
        IM_ASSERT(builder.PackIdLinesTexData ~= ImFontAtlasRectId_Invalid)
    end

    for n = 0, IM_DRAWLIST_TEX_LINES_WIDTH_MAX do -- +1 because of the zero-width row
        -- Each line consists of at least two empty pixels at the ends, with a line of solid pixels in the middle
        local y = n
        local line_width = n

        --- @type int # If not floored, will cause black and purple horizontal stripes appearing on the right of the arrow(triangle) in the upper-left most area of the atlas
        local pad_left = math.floor((r.w - line_width) / 2)
        --- @type int
        local pad_right = r.w - (pad_left + line_width)

        IM_ASSERT(pad_left + line_width + pad_right == r.w and y < r.h) -- Make sure we're inside the texture bounds before we start writing pixels

        -- Write each slice
        if (add_and_draw and tex.Format == ImTextureFormat.Alpha8) then
            local write_ptr, write_ptr_base = tex:GetPixelsAt(r.x, r.y + y)

            for i = 0, pad_left - 1 do
                write_ptr[write_ptr_base + i] = 0x00
            end

            for i = 0, line_width - 1 do
                write_ptr[write_ptr_base + pad_left + i] = 0xFF
            end

            for i = 0, pad_right - 1 do
                write_ptr[write_ptr_base + pad_left + line_width + i] = 0x00
            end
        elseif (add_and_draw and tex.Format == ImTextureFormat.RGBA32) then
            local write_ptr, write_ptr_base = tex:GetPixelsAt(r.x, r.y + y)

            for i = 0, pad_left - 1 do
                write_u32(write_ptr, write_ptr_base + i * 4, IM_COL32(255, 255, 255, 0))
            end

            for i = 0, line_width - 1 do
                write_u32(write_ptr, write_ptr_base + (pad_left + i) * 4, IM_COL32_WHITE)
            end

            for i = 0, pad_right - 1 do
                write_u32(write_ptr, write_ptr_base + (pad_left + line_width + i) * 4, IM_COL32(255, 255, 255, 0))
            end
        end

        -- Refresh UV coordinates
        local uv0 = ImVec2(r.x + pad_left - 1, r.y + y) * atlas.TexUvScale
        local uv1 = ImVec2(r.x + pad_left + line_width + 1, r.y + y + 1) * atlas.TexUvScale
        local half_v = (uv0.y + uv1.y) * 0.5 -- Calculate a constant V in the middle of the row to avoid sampling artifacts
        atlas.TexUvLines[n] = ImVec4(uv0.x, half_v, uv1.x, half_v)
    end
end

-- Render a white-colored bitmap encoded in a string
--- @param atlas          ImFontAtlas
--- @param x              int
--- @param y              int
--- @param w              int
--- @param h              int
--- @param in_str         string[]
--- @param in_marker_char string
function ImFontAtlasBuildRenderBitmapFromString(atlas, x, y, w, h, in_str, in_marker_char)
    local tex = atlas.TexData
    IM_ASSERT(x >= 0 and x + w <= tex.Width)
    IM_ASSERT(y >= 0 and y + h <= tex.Height)

    if tex.Format == ImTextureFormat.Alpha8 then
        local out_p, out_p_base = tex:GetPixelsAt(x, y)
        local str_base = 1
        for off_y = 0, h - 1 do
            for off_x = 0, w - 1 do
                out_p[out_p_base + off_x] = (in_str[str_base + off_x] == in_marker_char) and 0xFF or 0x00
            end

            out_p_base = out_p_base + tex.Width
            str_base = str_base + w
        end
    elseif tex.Format == ImTextureFormat.RGBA32 then
        local out_p, out_p_base = tex:GetPixelsAt(x, y)
        local str_base = 1
        for off_y = 0, h - 1 do
            for off_x = 0, w - 1 do
                write_u32(out_p, out_p_base + off_x * 4, (in_str[str_base + off_x] == in_marker_char) and IM_COL32_WHITE or IM_COL32_BLACK_TRANS)
            end

            out_p_base = out_p_base + tex.Width * 4
            str_base = str_base + w
        end
    end
end

--- @param atlas ImFontAtlas
function ImFontAtlasBuildUpdateTexDataBasic(atlas)
    -- Pack and store identifier so we can refresh UV coordinates on texture resize.
    -- FIXME-NEWATLAS: User/custom rects where user code wants to store UV coordinates will need to do the same thing.
    local builder = atlas.Builder
    local pack_size = (bit32.band(atlas.Flags, ImFontAtlasFlags.NoMouseCursors) ~= 0) and ImVec2(2, 2) or ImVec2(FONT_ATLAS_DEFAULT_TEX_DATA_W * 2 + 1, FONT_ATLAS_DEFAULT_TEX_DATA_H)

    local r = ImFontAtlasRect()
    local add_and_draw = (atlas:GetCustomRect(builder.PackIdMouseCursors, r) == false)
    if (add_and_draw) then
        builder.PackIdMouseCursors = atlas:AddCustomRect(pack_size.x, pack_size.y, r)
        IM_ASSERT(builder.PackIdMouseCursors ~= ImFontAtlasRectId_Invalid)

        -- Draw to texture
        if bit32.band(atlas.Flags, ImFontAtlasFlags.NoMouseCursors) ~= 0 then
            -- 2x2 white pixels
            ImFontAtlasBuildRenderBitmapFromString(atlas, r.x, r.y, 2, 2, {"X", "X", "X", "X"}, "X")
        else
            -- 2x2 white pixels + mouse cursors
            local x_for_white = r.x
            local x_for_black = r.x + FONT_ATLAS_DEFAULT_TEX_DATA_W + 1
            ImFontAtlasBuildRenderBitmapFromString(atlas, x_for_white, r.y, FONT_ATLAS_DEFAULT_TEX_DATA_W, FONT_ATLAS_DEFAULT_TEX_DATA_H, FONT_ATLAS_DEFAULT_TEX_DATA_PIXELS, ".")
            ImFontAtlasBuildRenderBitmapFromString(atlas, x_for_black, r.y, FONT_ATLAS_DEFAULT_TEX_DATA_W, FONT_ATLAS_DEFAULT_TEX_DATA_H, FONT_ATLAS_DEFAULT_TEX_DATA_PIXELS, "X")
        end
    end

    -- Refresh UV coordinates
    atlas.TexUvWhitePixel = ImVec2((r.x + 0.5) * atlas.TexUvScale.x, (r.y + 0.5) * atlas.TexUvScale.y)
end

-- Update texture coordinates in all draw list shared context
-- FIXME-NEWATLAS FIXME-OPT: Doesn't seem necessary to update for all, only one bound to current context?
function ImFontAtlasUpdateDrawListsSharedData(atlas)
    for _, shared_data in atlas.DrawListSharedDatas:iter() do
        if (shared_data.FontAtlas == atlas) then
            shared_data.TexUvWhitePixel = atlas.TexUvWhitePixel
            shared_data.TexUvLines = atlas.TexUvLines
        end
    end
end

-- Start packing over current empty texture
function ImFontAtlasBuildInit(atlas)
    -- Select Backend
    -- - Note that we do not reassign to atlas.FontLoader, since it is likely to point to static data which
    --   may mess with some hot-reloading schemes. If you need to assign to this (for dynamic selection) AND are
    --   using a hot-reloading scheme that messes up static data, store your own instance of FontLoader somewhere
    --   and point to it instead of pointing directly to return value of the GetFontLoaderXXX functions.
    if atlas.FontLoader == nil then
        -- IMGUI_ENABLE_STB_TRUETYPE
        atlas:SetFontLoader(ImFontAtlasGetFontLoaderForStbTruetype())
    end

    -- Create initial texture size
    if atlas.TexData == nil or atlas.TexData.Pixels == nil then
        ImFontAtlasTextureAdd(atlas, ImUpperPowerOfTwo(atlas.TexMinWidth), ImUpperPowerOfTwo(atlas.TexMinHeight))
    end
    atlas.Builder = ImFontAtlasBuilder()
    if atlas.FontLoader.LoaderInit then
        atlas.FontLoader.LoaderInit(atlas)
    end

    ImFontAtlasBuildUpdateRendererHasTexturesFromContext(atlas)

    ImFontAtlasPackInit(atlas)

    -- Add required texture data
    ImFontAtlasBuildUpdateTexData(atlas)

    -- Register fonts
    ImFontAtlasBuildUpdatePointers(atlas)

    -- Update UV coordinates etc. stored in bound ImDrawListSharedData instance
    ImFontAtlasUpdateDrawListsSharedData(atlas)

    --atlas.TexIsBuilt = true

    -- Lazily initialize char/text classifier
    -- FIXME: This could be practically anywhere, and should eventually be parameters to CalcTextSize/word-wrapping code, but there's no obvious spot now.
    ImTextInitClassifiers()
end

-- Destroy builder and all cached glyphs. Do not destroy actual fonts.
--- @param atlas ImFontAtlas
function ImFontAtlasBuildDestroy(atlas)
    for _, font in atlas.Fonts:iter() do
        ImFontAtlasFontDestroyOutput(atlas, font)
    end
    if atlas.Builder and atlas.FontLoader and atlas.FontLoader.LoaderShutdown then
        atlas.FontLoader.LoaderShutdown(atlas)
        IM_ASSERT(atlas.FontLoaderData == nil)
    end
    atlas.Builder = nil
end

-- On font removal we need to remove references (otherwise we could queue removal?)
-- We allow old_font == new_font which forces updating all values (e.g. sizes)
--- @param atlas    ImFontAtlas
--- @param old_font ImFont?
--- @param new_font ImFont?
function ImFontAtlasBuildNotifySetFont(atlas, old_font, new_font)
    for _, shared_data in atlas.DrawListSharedDatas:iter() do
        if shared_data.Font == old_font then
            shared_data.Font = new_font
        end
        local ctx = shared_data.Context
        if ctx then
            repeat
            -- While this should work either way, we save ourselves the bother / debugging confusion of running ImGui code so early when it is not needed.
            -- Also fixes erroneously rewriting style.FontSizeBase during init if adding default fonts.
            if old_font == nil and ctx.Font == nil and ctx.FontSizeBase == 0.0 then

                break
            end

            if ctx.IO.FontDefault == old_font then
                ctx.IO.FontDefault = new_font
            end
            if ctx.Font == old_font then
                local curr_ctx = ImGui.GetCurrentContext()
                local need_bind_ctx = ctx ~= curr_ctx
                if need_bind_ctx then
                    ImGui.SetCurrentContext(ctx)
                end
                ImGui.SetCurrentFont(new_font, ctx.FontSizeBase, ctx.FontSize)
                if need_bind_ctx then
                    ImGui.SetCurrentContext(curr_ctx)
                end
            end
            for _, font_stack_data in ctx.FontStack:iter() do
                if font_stack_data.Font == old_font then
                    font_stack_data.Font = new_font
                end
            end

            until true
        end
    end
end

-- When atlas.RendererHasTextures = true, this is only called if no font were loaded.
--- @param atlas ImFontAtlas
function ImFontAtlasBuildMain(atlas)
    IM_ASSERT(not atlas.Locked, "Cannot modify a locked ImFontAtlas!")
    if (atlas.TexData and atlas.TexData.Format ~= atlas.TexDesiredFormat) then
        ImFontAtlasBuildClear(atlas)
    end

    if atlas.Builder == nil then
        ImFontAtlasBuildInit(atlas)
    end

    -- Default font is none are specified
    if atlas.Sources.Size == 0 then
        atlas:AddFontDefault()
    end

    -- [LEGACY] For backends not supporting RendererHasTextures: preload all glyphs
    -- ImFontAtlasBuildUpdateRendererHasTexturesFromContext(atlas);
    -- if atlas.RendererHasTextures == false then -- ~ImGuiBackendFlags.RendererHasTextures
    --     ImFontAtlasBuildLegacyPreloadAllGlyphRanges(atlas)
    -- end

    atlas.TexIsBuilt = true
end

-------------------------------------------------------------------------------
-- [SECTION] ImTextureData
-------------------------------------------------------------------------------
-- - ImTextureData:Create()
-- - ImTextureData:DestroyPixels()
-------------------------------------------------------------------------------

function MT.ImTextureData:DestroyPixels()
    self.Pixels = nil
    self.UseColors = false
end

function ImTextureDataGetFormatBytesPerPixel(format)
    if format == ImTextureFormat.Alpha8 then
        return 1
    elseif format == ImTextureFormat.RGBA32 then
        return 4
    end
    IM_ASSERT(false)
    return 0
end

function MT.ImTextureData:Create(format, w, h)
    IM_ASSERT(self.Status == ImTextureStatus.Destroyed)
    self:DestroyPixels()
    self.Format = format
    self.Status = ImTextureStatus.WantCreate
    self.Width = w
    self.Height = h
    self.BytesPerPixel = ImTextureDataGetFormatBytesPerPixel(format)
    self.UseColors = false
    self.Pixels = {}
    ImStd.memset(self.Pixels, 0, self.Width * self.Height * self.BytesPerPixel)
    self.UsedRect.x = 0
    self.UsedRect.y = 0
    self.UsedRect.w = 0
    self.UsedRect.h = 0
    self.UpdateRect.x = 65535
    self.UpdateRect.y = 65535
    self.UpdateRect.w = 0
    self.UpdateRect.h = 0
end

-------------------------------------------------------------------------------
-- [SECTION] ImFontBaked, ImFont
-------------------------------------------------------------------------------

function MT.ImFontBaked:ClearOutputData()
    self.FallbackAdvanceX = 0.0
    self.Glyphs:clear()
    self.IndexAdvanceX:clear()
    self.IndexLookup:clear()
    self.FallbackGlyphIndex = -1
    self.Ascent = 0.0
    self.Descent = 0.0
    self.MetricsTotalSurface = 0
end

-- Find glyph, load if necessary, return fallback if missing
--- @param c ImWchar
--- @return ImFontGlyph?
function MT.ImFontBaked:FindGlyph(c)
    if c < self.IndexLookup.Size then
        local i = self.IndexLookup.Data[c + 1]
        if i == IM_FONTGLYPH_INDEX_NOT_FOUND then
            return self.Glyphs.Data[self.FallbackGlyphIndex]
        end
        if i ~= IM_FONTGLYPH_INDEX_UNUSED then
            return self.Glyphs.Data[i]
        end
    end

    local glyph = ImFontBaked_BuildLoadGlyph(self, c, nil)
    return (glyph) and glyph or self.Glyphs.Data[self.FallbackGlyphIndex]
end

function MT.ImFontBaked:IsGlyphLoaded(c)
    if c >= self.IndexLookup.Size then return false end
    return self.IndexLookup.Data[c + 1] ~= IM_FONTGLYPH_INDEX_UNUSED
end

-- Attempt to load but when missing, return nil instead of FallbackGlyph
--- @param c ImWchar
--- @return ImFontGlyph?
function MT.ImFontBaked:FindGlyphNoFallback(c)
    if c < self.IndexLookup.Size then -- IM_LIKELY
        local i = self.IndexLookup.Data[c + 1]
        if i == IM_FONTGLYPH_INDEX_NOT_FOUND then
            return nil
        end
        if i ~= IM_FONTGLYPH_INDEX_UNUSED then
            return self.Glyphs.Data[i]
        end
    end

    self.LoadNoFallback = true -- This is actually a rare call, not done in hot-loop, so we prioritize not adding extra cruft to ImFontBaked_BuildLoadGlyph() call sites.
    local glyph = ImFontBaked_BuildLoadGlyph(self, c, nil)
    self.LoadNoFallback = false
    return glyph
end

function MT.ImFont:ClearOutputData()
    local atlas = self.OwnerAtlas
    if atlas ~= nil then
        ImFontAtlasFontDiscardBakes(atlas, self, 0)
    end
    --self.FallbackChar = 0 self.EllipsisChar = 0

    for i = 1, (IM_UNICODE_CODEPOINT_MAX + 1) / 8192 / 8 do self.Used8kPagesMap[i] = 0 end
    self.LastBaked = nil
end

--- @param font_id            ImGuiID
--- @param baked_size         float
--- @param rasterizer_density float
--- @return ImGuiID
function ImFontAtlasBakedGetId(font_id, baked_size, rasterizer_density)
    local hashed_data = {font_id, baked_size, rasterizer_density}
    return ImHashData(hashed_data)
end

--- @param atlas                   ImFontAtlas
--- @param font                    ImFont
--- @param font_size               float
--- @param font_rasterizer_density float
--- @return ImFontBaked?
function ImFontAtlasBakedGetOrAdd(atlas, font, font_size, font_rasterizer_density)
    -- FIXME-NEWATLAS: Design for picking a nearest size based on some criteria?
    -- FIXME-NEWATLAS: Altering font density won't work right away.
    IM_ASSERT(font_size > 0.0 and font_rasterizer_density > 0.0)
    local baked_id = ImFontAtlasBakedGetId(font.FontId, font_size, font_rasterizer_density)
    local builder = atlas.Builder
    local baked = builder.BakedMap[baked_id]
    if baked ~= nil then
        IM_ASSERT(baked.Size == font_size and baked.OwnerFont == font and baked.BakedId == baked_id)

        return baked
    end

    -- If atlas is locked, find closest match
    -- FIXME-OPT: This is not an optimal query.
    if (bit32.band(font.Flags, ImFontFlags.LockBakedSizes) ~= 0 or atlas.Locked) then
        baked = ImFontAtlasBakedGetClosestMatch(atlas, font, font_size, font_rasterizer_density)
        if baked ~= nil then
            return baked
        end
        if atlas.Locked then
            IM_ASSERT(not atlas.Locked, "Cannot use dynamic font size with a locked ImFontAtlas!") -- Locked because rendering backend does not support ImGuiBackendFlags.RendererHasTextures!
            return nil
        end
    end

    -- Create new
    baked = ImFontAtlasBakedAdd(atlas, font, font_size, font_rasterizer_density, baked_id)
    builder.BakedMap[baked_id] = baked

    return baked
end

-- x0/y0/x1/y1 are offset from the character upper-left layout position, in pixels. Therefore x0/y0 are often fairly close to zero.
-- Not to be mistaken with texture coordinates, which are held by u0/v0/u1/v1 in normalized format (0.0..1.0 on each texture axis).
-- - 'src' is not necessarily == 'self.Sources' because multiple source fonts+configs can be used to build one target font.
--- @param atlas    ImFontAtlas
--- @param baked    ImFontBaked
--- @param src?     ImFontConfig
--- @param in_glyph ImFontGlyph
--- @return ImFontGlyph
function ImFontAtlasBakedAddFontGlyph(atlas, baked, src, in_glyph)
    local glyph_idx = baked.Glyphs.Size + 1
    baked.Glyphs:push_back(in_glyph)
    local glyph = baked.Glyphs.Data[glyph_idx]
    IM_ASSERT(baked.Glyphs.Size < 0xFFFE) -- IndexLookup[] hold 16-bit values and -1/-2 are reserved.

    -- Set UV from packed rectangle
    if (glyph.PackId ~= ImFontAtlasRectId_Invalid) then
        local r = ImFontAtlasPackGetRect(atlas, glyph.PackId)
        IM_ASSERT(glyph.U0 == 0.0 and glyph.V0 == 0.0 and glyph.U1 == 0.0 and glyph.V1 == 0.0)
        glyph.U0 = (r.x) * atlas.TexUvScale.x
        glyph.V0 = (r.y) * atlas.TexUvScale.y
        glyph.U1 = (r.x + r.w) * atlas.TexUvScale.x
        glyph.V1 = (r.y + r.h) * atlas.TexUvScale.y
        baked.MetricsTotalSurface = baked.MetricsTotalSurface + r.w * r.h
    end

    if (src ~= nil) then
        -- Clamp & recenter if needed
        local ref_size = baked.OwnerFont.Sources[1].SizePixels
        local offsets_scale = (ref_size ~= 0.0) and (baked.Size / ref_size) or 1.0
        local advance_x = ImClamp(glyph.AdvanceX, src.GlyphMinAdvanceX * offsets_scale, src.GlyphMaxAdvanceX * offsets_scale)
        if (advance_x ~= glyph.AdvanceX) then
            local char_off_x = src.PixelSnapH and ImTrunc((advance_x - glyph.AdvanceX) * 0.5) or (advance_x - glyph.AdvanceX) * 0.5
            glyph.X0 = glyph.X0 + char_off_x
            glyph.X1 = glyph.X1 + char_off_x
        end

        -- Snap to pixel
        if (src.PixelSnapH) then
            advance_x = IM_ROUND(advance_x)
        end

        -- Bake spacing
        glyph.AdvanceX = advance_x + src.GlyphExtraAdvanceX
    end
    if (glyph.Colored) then
        atlas.TexData.UseColors  = true
        atlas.TexPixelsUseColors = true
    end

    -- Update lookup tables
    local codepoint = glyph.Codepoint
    ImFontBaked_BuildGrowIndex(baked, codepoint + 1)
    baked.IndexAdvanceX.Data[codepoint + 1] = glyph.AdvanceX
    baked.IndexLookup.Data[codepoint + 1] = glyph_idx -- (ImU16)
    local page_n = math.floor(codepoint / 8192)
    baked.OwnerFont.Used8kPagesMap[bit32.rshift(page_n, 3) + 1] = bit32.bor(baked.OwnerFont.Used8kPagesMap[bit32.rshift(page_n, 3) + 1], bit32.lshift(1, bit32.band(page_n, 7)))

    return glyph
end

-- FIXME: Code is duplicated with code above.
--- @param atlas     ImFontAtlas
--- @param baked     ImFontBaked
--- @param src?      ImFontConfig
--- @param codepoint ImWchar
--- @param advance_x float
function ImFontAtlasBakedAddFontGlyphAdvancedX(atlas, baked, src, codepoint, advance_x)
    -- IM_UNUSED(atlas)
    if (src ~= nil) then
        -- Clamp & recenter if needed
        local ref_size = baked.OwnerFont.Sources[1].SizePixels
        local offsets_scale = (ref_size ~= 0.0) and (baked.Size / ref_size) or 1.0
        advance_x = ImClamp(advance_x, src.GlyphMinAdvanceX * offsets_scale, src.GlyphMaxAdvanceX * offsets_scale)

        -- Snap to pixel
        if (src.PixelSnapH) then
            advance_x = IM_ROUND(advance_x)
        end

        -- Bake spacing
        advance_x = advance_x + src.GlyphExtraAdvanceX
    end

    ImFontBaked_BuildGrowIndex(baked, codepoint + 1)
    baked.IndexAdvanceX.Data[codepoint + 1] = advance_x
end

-- ImFontBaked are valid for the entire frame but shall never be kept between frames.
--- @param size    float
--- @param density float?
--- @return ImFontBaked?
function MT.ImFont:GetFontBaked(size, density)
    if not density then density = -1.0 end

    --- @type ImFontBaked?
    local baked = self.LastBaked

    -- Round font size
    -- - ImGui.PushFont() will already round, but other paths calling GetFontBaked() directly also needs it (e.g. ImFontAtlasBuildPreloadAllGlyphRanges)
    size = math.floor(size + 0.5) -- [Luau] inline ImGui.GetRoundedFontSize() == IM_ROUND()

    if density < 0.0 then
        density = self.CurrentRasterizerDensity
    end
    if baked and baked.Size == size and baked.RasterizerDensity == density then
        return baked
    end

    local atlas = self.OwnerAtlas
    local builder = atlas.Builder
    baked = ImFontAtlasBakedGetOrAdd(atlas, self, size, density)
    if baked == nil then
        return nil
    end
    baked.LastUsedFrame = builder.FrameCount
    self.LastBaked = baked

    return baked
end

--- @param atlas ImFontAtlas
--- @param font  ImFont
--- @param c     ImWchar
--- @return ImWchar
--- @nodiscard
local function ImFontAtlas_FontHookRemapCodepoint(atlas, font, c)
    -- IM_UNUSED(atlas)
    if #font.RemapPairs > 0 then
        local ret = font.RemapPairs[c]
        return (ret ~= nil) and ret or c
    end

    return c
end

--- @param baked                ImFontBaked
--- @param codepoint            ImWchar
--- @param only_load_advance_x? float
--- @return ImFontGlyph?
--- @return float?       # Updated `only_load_advance_x`
function ImFontBaked_BuildLoadGlyph(baked, codepoint, only_load_advance_x)
    local font = baked.OwnerFont
    local atlas = font.OwnerAtlas
    if atlas.Locked or bit32.band(font.Flags, ImFontFlags.NoLoadGlyphs) ~= 0 then
        -- Lazily load fallback glyph
        if baked.FallbackGlyphIndex == -1 and baked.LoadNoFallback == false then
            ImFontAtlasBuildSetupFontBakedFallback(baked)
        end

        return nil, only_load_advance_x
    end

    -- User remapping hooks
    local src_codepoint = codepoint
    codepoint = ImFontAtlas_FontHookRemapCodepoint(atlas, font, codepoint)

    --IMGUI_DEBUG_LOG("[font] BuildLoadGlyph U+%04X (%s)", codepoint, ImTextCharToUtf8(codepoint))

    -- Special hook
    -- FIXME-NEWATLAS: it would be nicer if this used a more standardized way of hooking
    if (codepoint == font.EllipsisChar and font.EllipsisAutoBake) then
        local glyph = ImFontAtlasBuildSetupFontBakedEllipsis(atlas, baked)
        if (glyph) then
            return glyph, only_load_advance_x
        end
    end

    -- Call backend
    local loader_user_data_p = baked.FontLoaderDatas
    local src_n = 1
    for _, src in font.Sources:iter() do
        local loader = src.FontLoader and src.FontLoader or atlas.FontLoader

        if (not src.GlyphExcludeRanges or ImFontAtlasBuildAcceptCodepointForSource(src, codepoint)) then
            if only_load_advance_x == nil then
                local glyph_buf = ImFontGlyph()

                if loader.FontBakedLoadGlyph(atlas, src, baked, loader_user_data_p, codepoint, glyph_buf, nil) then
                    -- FIXME: Add hooks for e.g. #7962
                    glyph_buf.Codepoint = src_codepoint
                    glyph_buf.SourceIdx = src_n

                    return ImFontAtlasBakedAddFontGlyph(atlas, baked, src, glyph_buf)
                end
            else
                -- Special mode but only loading glyphs metrics. Will rasterize and pack later.
                local ret --[[@as bool]]
                ret, only_load_advance_x = loader.FontBakedLoadGlyph(atlas, src, baked, loader_user_data_p, codepoint, nil, only_load_advance_x)
                if ret then
                    --- @cast only_load_advance_x float
                    ImFontAtlasBakedAddFontGlyphAdvancedX(atlas, baked, src, codepoint, only_load_advance_x)

                    return nil, only_load_advance_x
                end
            end
        end

        -- loader_user_data_p = loader_user_data_p + loader.FontBakedSrcLoaderDataSize
        src_n = src_n + 1
    end

    -- Lazily load fallback glyph
    if (baked.LoadNoFallback) then
        return nil, only_load_advance_x
    end
    if (baked.FallbackGlyphIndex == -1) then
        ImFontAtlasBuildSetupFontBakedFallback(baked)
    end

    -- Mark index as not found, so we don't attempt the search twice
    ImFontBaked_BuildGrowIndex(baked, codepoint + 1);
    baked.IndexAdvanceX.Data[codepoint + 1] = baked.FallbackAdvanceX
    baked.IndexLookup.Data[codepoint + 1] = IM_FONTGLYPH_INDEX_NOT_FOUND

    return nil, only_load_advance_x
end

--- @param baked ImFontBaked
--- @param codepoint ImWchar
--- @return float
function ImFontBaked_BuildLoadGlyphAdvanceX(baked, codepoint)
    if (baked.Size >= IMGUI_FONT_SIZE_THRESHOLD_FOR_LOADADVANCEXONLYMODE) or baked.LoadNoRenderOnLayout then
        -- First load AdvanceX value used by CalcTextSize() API then load the rest when loaded by drawing API.
        local only_advance_x
        local glyph
        glyph, only_advance_x = ImFontBaked_BuildLoadGlyph(baked, codepoint, only_advance_x)
        --- @cast only_advance_x float
        return glyph and glyph.AdvanceX or only_advance_x
    else
        local glyph = ImFontBaked_BuildLoadGlyph(baked, codepoint, nil)
        return glyph and glyph.AdvanceX or baked.FallbackAdvanceX
    end
end

-- This is not fast query
--- @param c ImWchar
--- @return bool
function MT.ImFont:IsGlyphInFont(c)
    local atlas = self.OwnerAtlas
    c = ImFontAtlas_FontHookRemapCodepoint(atlas, self, c)
    for _, src in self.Sources:iter() do
        local loader = src.FontLoader and src.FontLoader or atlas.FontLoader
        if loader.FontSrcContainsGlyph ~= nil and loader.FontSrcContainsGlyph(atlas, src, c) then
            return true
        end
    end

    return false
end

-- This is manually inlined in CalcTextSizeA() and CalcWordWrapPosition(), with a non-inline call to BuildLoadGlyphGetAdvanceOrFallback().
--- @param c ImWchar
--- @return float
function MT.ImFontBaked:GetCharAdvance(c)
    if c < self.IndexAdvanceX.Size then
        -- Missing glyphs fitting inside index will have stored FallbackAdvanceX already.
        local x = self.IndexAdvanceX.Data[c + 1]
        if x >= 0.0 then
            return x
        end
    end
    return ImFontBaked_BuildLoadGlyphAdvanceX(self, c)
end

-- The point of this indirection is to not be inlined in debug mode in order to not bloat inner loop.b
function BuildLoadGlyphGetAdvanceOrFallback(baked, codepoint)
    return ImFontBaked_BuildLoadGlyphAdvanceX(baked, codepoint)
end

-- Trim trailing space and find beginning of next line
--- @param text       ImString
--- @param text_begin int
--- @param text_end   int
--- @param flags      ImDrawTextFlags
--- @return int
local function ImTextCalcWordWrapNextLineStart(text, text_begin, text_end, flags)
    local pos = text_begin

    if bit32.band(flags, ImDrawTextFlags.WrapKeepBlanks) == 0 then
        while pos < text_end and ImCharIsBlankA(ImStrByte(text, pos)) do
            pos = pos + 1
        end
    end

    if pos < text_end and ImStrByte(text, pos) == 10 then -- '\n'
        pos = pos + 1
    end

    return pos
end

--- @param bits          ImU32[]
--- @param codepoint_min unsigned_int
--- @param codepoint_end unsigned_int
--- @param char_class    ImWcharClass
function ImTextClassifierClear(bits, codepoint_min, codepoint_end, char_class)
    for c = codepoint_min, codepoint_end - 1 do
        ImTextClassifierSetCharClass(bits, codepoint_min, codepoint_end, char_class, c)
    end
end

--- @param bits          ImU32[]
--- @param codepoint_min unsigned_int
--- @param codepoint_end unsigned_int
--- @param char_class    ImWcharClass
--- @param c             unsigned_int
function ImTextClassifierSetCharClass(bits, codepoint_min, codepoint_end, char_class, c)
    IM_ASSERT(c >= codepoint_min and c < codepoint_end)
    -- IM_UNUSED(codepoint_end)
    c = c - codepoint_min
    local shift = bit32.lshift(bit32.band(c, 15), 1)
    bits[bit32.rshift(c, 4) + 1] = bit32.bor(bit32.band(bits[bit32.rshift(c, 4) + 1], bit32.bnot(bit32.lshift(0x03, shift))), bit32.lshift(char_class, shift))
end

function ImTextClassifierSetCharClassFromStr(bits, codepoint_min, codepoint_end, char_class, s)
    local s_end = #s + 1
    local pos = 1
    while (pos < s_end) do
        local wanted, c = ImStd.ImTextCharFromUtf8(s, pos, s_end)
        pos = pos + wanted
        ImTextClassifierSetCharClass(bits, codepoint_min, codepoint_end, char_class, c)
    end
end

function ImTextClassifierGet(_BITS, _CHAR_OFFSET)
    return bit32.band(bit32.rshift(_BITS[bit32.rshift(_CHAR_OFFSET, 4) + 1], bit32.lshift(bit32.band(_CHAR_OFFSET, 15), 1)), 0x03)
end

-- 2-bit per character
local g_CharClassifierIsSeparator_0000_007f = {} for i = 1, 128 / 16 do g_CharClassifierIsSeparator_0000_007f[i] = 0 end
local g_CharClassifierIsSeparator_3000_300f = {} for i = 1, 16 / 16 do g_CharClassifierIsSeparator_3000_300f[i] = 0 end

function ImTextInitClassifiers()
    if (ImTextClassifierGet(g_CharClassifierIsSeparator_0000_007f, 44) ~= 0) then -- ','
        return
    end

    -- List of hardcoded separators: .,;!?'"
    -- Making this dynamic given known ranges is trivial BUT requires us to standardize where you pass them as parameters. (#3002, #8503)
    ImTextClassifierClear(g_CharClassifierIsSeparator_0000_007f, 0, 128, ImWcharClass.Other)
    ImTextClassifierSetCharClassFromStr(g_CharClassifierIsSeparator_0000_007f, 0, 128, ImWcharClass.Blank, " \t")
    ImTextClassifierSetCharClassFromStr(g_CharClassifierIsSeparator_0000_007f, 0, 128, ImWcharClass.Punct, ".,;!?\"")

    ImTextClassifierClear(g_CharClassifierIsSeparator_3000_300f, 0x3000, 0x300F, ImWcharClass.Other)
    ImTextClassifierSetCharClass(g_CharClassifierIsSeparator_3000_300f, 0x3000, 0x300F, ImWcharClass.Blank, 0x3000)
    ImTextClassifierSetCharClass(g_CharClassifierIsSeparator_3000_300f, 0x3000, 0x300F, ImWcharClass.Punct, 0x3001)
    ImTextClassifierSetCharClass(g_CharClassifierIsSeparator_3000_300f, 0x3000, 0x300F, ImWcharClass.Punct, 0x3002)
end

-- Simple word-wrapping for English, not full-featured. Please submit failing cases!
-- This will return the next location to wrap from. If no wrapping if necessary, this will fast-forward to e.g. text_end.
-- Refer to imgui_test_suite's "drawlist_text_wordwrap_1" for tests.
--- @param font       ImFont
--- @param size       float
--- @param text       ImString
--- @param pos        int
--- @param text_end   int
--- @param wrap_width float
--- @param flags      ImDrawTextFlags
--- @return int
local ImFontCalcWordWrapPositionEx_Uncached
local WRAP_MEMO_MAX = 4096

function ImFontCalcWordWrapPositionEx(font, size, text, pos, text_end, wrap_width, flags)
    local baked = font:GetFontBaked(size)
    if type(text) ~= "string" then
        return ImFontCalcWordWrapPositionEx_Uncached(baked, size, text, pos, text_end, wrap_width, flags)
    end
    -- [Luau] memo per baked font and string: CalcTextSize() and RenderText() of wrapped text ask for the same wrap points
    -- (same text/pos/width) every frame. The result only depends on these inputs and the (immutable once loaded) glyph advances.
    -- ponytail: whole-memo reset at WRAP_MEMO_MAX strings, LRU if dynamic text churns it
    local memo = baked._WrapMemo
    if memo == nil or baked._WrapMemoN >= WRAP_MEMO_MAX then
        memo = {}; baked._WrapMemo = memo; baked._WrapMemoN = 0
    end
    local e = memo[text]
    if e == nil or e.ww ~= wrap_width or e.size ~= size or e.te ~= text_end or e.fl ~= flags then
        if e == nil then baked._WrapMemoN = baked._WrapMemoN + 1 end
        e = { ww = wrap_width, size = size, te = text_end, fl = flags }
        memo[text] = e
    else
        local r = e[pos]
        if r then return r end
    end
    local r = ImFontCalcWordWrapPositionEx_Uncached(baked, size, text, pos, text_end, wrap_width, flags)
    e[pos] = r
    return r
end


function ImFontCalcWordWrapPositionEx_Uncached(baked, size, text, pos, text_end, wrap_width, flags)
    -- For references, possible wrap point marked with ^
    --  "aaa bbb, ccc,ddd. eee   fff. ggg!"
    --      ^    ^    ^   ^   ^__    ^    ^

    -- Skip extra blanks after a line returns (that includes not counting them in width computation)
    -- e.g. "Hello    world" --> "Hello" "World"

    -- Cut words that cannot possibly fit within one line.
    -- e.g.: "The tropical fish" with ~5 characters worth of width --> "The tr" "opical" "fish"

    -- [Luau] baked = font:GetFontBaked(size) is done by the caller
    local scale = size / baked.Size

    local line_width = 0.0
    local blank_width = 0.0
    wrap_width = wrap_width / scale -- We work with unscaled widths to avoid scaling every characters

    local s = pos
    IM_ASSERT(text_end ~= nil)

    local prev_type = ImWcharClass.Other
    local keep_blanks = bit32.band(flags, ImDrawTextFlags.WrapKeepBlanks) ~= 0

    -- Find next wrapping point
    --local span_begin = s
    local span_end = s
    local span_width = 0.0

    local stop = false
    local text_is_str = type(text) == "string" -- [Luau] ImStrByte() inlined (once per character)
    local adv_data, adv_n = baked.IndexAdvanceX.Data, baked.IndexAdvanceX.Size -- [Luau] hoisted, refreshed after a glyph load
    local CLASS_BLANK, CLASS_PUNCT, CLASS_OTHER = ImWcharClass.Blank, ImWcharClass.Punct, ImWcharClass.Other
    local classifier_0000_007f = g_CharClassifierIsSeparator_0000_007f
    while s < text_end do
        repeat
        --- @type unsigned_int
        local c
        if text_is_str then c = string.byte(text, s) else c = text[s] end
        local next_s
        if c < 0x80 then
            next_s = s + 1
        else
            local wanted, out_char = ImStd.ImTextCharFromUtf8(text, s, text_end)
            c = out_char
            next_s = s + wanted
        end

        if c < 32 then
            if c == 10 then -- '\n'
                return s -- Direct return, skip "Wrap_width is too small to fit anything" path.
            end
            if c == 13 then -- '\r'
                s = next_s -- Fast-skip

                break
            end
        end

        -- Optimized inline version of 'float char_width = GetCharAdvance((ImWchar)c);'
        local char_width = (c < adv_n) and adv_data[c + 1] or -1.0
        if char_width < 0.0 then
            char_width = BuildLoadGlyphGetAdvanceOrFallback(baked, c)
            adv_data, adv_n = baked.IndexAdvanceX.Data, baked.IndexAdvanceX.Size
        end

        -- Classify current character
        local curr_type
        if c < 128 then -- [Luau] ImTextClassifierGet() inlined
            curr_type = bit32.band(bit32.rshift(classifier_0000_007f[bit32.rshift(c, 4) + 1], bit32.lshift(bit32.band(c, 15), 1)), 0x03)
        elseif (c >= 0x3000 and c < 0x3010) then
            curr_type = ImTextClassifierGet(g_CharClassifierIsSeparator_3000_300f, bit32.band(c, 15))
        else
            curr_type = CLASS_OTHER
        end

        if curr_type == CLASS_BLANK then
            -- End span: 'A ' or '. '
            if (prev_type ~= CLASS_BLANK and not keep_blanks) then
                span_end = s
                line_width = line_width + span_width
                span_width = 0.0
            end

            blank_width = blank_width + char_width
        else
            -- End span: '.X' unless X is a digit
            if (prev_type == CLASS_PUNCT and curr_type ~= CLASS_PUNCT and not (c >= 48 and c <= 57)) then -- FIXME: Digit checks might be removed if allow custom separators (#8503)
                span_end = s
                line_width = line_width + (span_width + blank_width)
                blank_width = 0.0
                span_width = 0.0
            -- End span: 'A ' or '. '
            elseif (prev_type == CLASS_BLANK and keep_blanks) then
                span_end = s
                line_width = line_width + (span_width + blank_width)
                blank_width = 0.0
                span_width = 0.0
            end

            span_width = span_width + char_width
        end

        if (span_width + blank_width + line_width > wrap_width) then
            if span_width + blank_width > wrap_width then
                stop = true; break
            end
            -- FIXME: Narrow wrapping e.g. "A quick brown" -> "Quic|k br|own", would require knowing if span is going to be longer than wrap_width.
            --if (span_width > wrap_width and not is_blank and not was_blank) then
            --    return s
            --end
            return span_end
        end

        prev_type = curr_type
        s = next_s

        until true
        if stop then break end
    end

    -- Wrap_width is too small to fit anything. Force displaying 1 character to minimize the height discontinuity.
    -- +1 may not be a character start point in UTF-8 but it's ok because caller loops use (text >= word_wrap_eol).
    if s == pos and s < text_end then
        local bytes = ImStd.ImTextCountUtf8BytesFromChar(text, s, text_end)

        return s + bytes
    end

    return s
end

--- @param font              ImFont
--- @param size              float
--- @param max_width         float
--- @param wrap_width        float
--- @param text              ImString
--- @param text_begin        int
--- @param text_end_display? int
--- @param text_end?         int
--- @param out_offset?       ImVec2
--- @param flags             ImDrawTextFlags
--- @return ImVec2 text_size
--- @return int    remaining
local TEXT_SIZE_CACHE_MAX = 4096


function ImFontCalcTextSizeEx(font, size, max_width, wrap_width, text, text_begin, text_end_display, text_end, out_offset, flags)
    local text_is_str = type(text) == "string"
    -- [Luau] cache for the common case (whole string, single pass, no wrap/limit): per baked font, text -> unscaled width, line count.
    -- Advances of a baked font never change once loaded, so entries stay valid. ponytail: whole-cache reset at TEXT_SIZE_CACHE_MAX entries, LRU if dynamic text churns it
    local cache_key = nil
    local wrap_cache = nil
    local text_len1 = text_is_str and #text + 1 or -1
    local cacheable = text_is_str and text_begin == 1 and out_offset == nil and max_width >= FLT_MAX
        and (text_end == nil or text_end == text_len1) and (text_end_display == nil or text_end_display == text_len1) and (flags == nil or bit32.band(flags, ImDrawTextFlags.StopOnNewLine) == 0)
    if cacheable and wrap_width <= 0.0 then
        local baked = font:GetFontBaked(size)
        local cache = baked._TextSizeCache
        if cache == nil or baked._TextSizeCacheN >= TEXT_SIZE_CACHE_MAX then
            cache = {}; baked._TextSizeCache = cache; baked._TextSizeCacheN = 0
        end
        local e = cache[text]
        if e then
            return ImVec2(e[1] * (size / baked.Size), e[2] * size), text_len1
        end
        cache_key = text
    elseif cacheable and wrap_width > 0.0 then
        -- [Luau] same for wrapped text (TextWrapped() measures every line every frame): exact results per (size, wrap width, text)
        local baked = font:GetFontBaked(size)
        local cache = baked._TextSizeCache
        if cache == nil or baked._TextSizeCacheN >= TEXT_SIZE_CACHE_MAX then
            cache = {}; baked._TextSizeCache = cache; baked._TextSizeCacheN = 0
        end
        local by_size = cache[size]
        if by_size == nil then by_size = {}; cache[size] = by_size end
        local by_wrap = by_size[wrap_width]
        if by_wrap == nil then by_wrap = {}; by_size[wrap_width] = by_wrap end
        local e = by_wrap[text]
        if e then
            return ImVec2(e[1], e[2]), e[3]
        end
        wrap_cache = by_wrap
    end
    if not text_end then
        text_end = #text + 1 -- FIXME-OPT: Need to avoid this.
    end
    if not text_end_display then
        text_end_display = text_end
    end

    local baked = font:GetFontBaked(size)
    local line_height = size
    local scale = line_height / baked.Size

    local text_size = ImVec2()
    local line_width = 0.0

    local word_wrap_enabled = (wrap_width > 0.0)
    local word_wrap_eol

    local s = text_begin
    local stop = false
    local adv_data, adv_n = baked.IndexAdvanceX.Data, baked.IndexAdvanceX.Size -- [Luau] hoisted, refreshed after a glyph load
    while s < text_end_display do
        repeat
        -- Word-wrapping
        if word_wrap_enabled then
            -- Calculate how far we can render. Requires two passes on the string data but keeps the code simple and not intrusive for what's essentially an uncommon feature.
            if not word_wrap_eol then
                word_wrap_eol = ImFontCalcWordWrapPositionEx(font, size, text, s, text_end, wrap_width - line_width, flags)
                adv_data, adv_n = baked.IndexAdvanceX.Data, baked.IndexAdvanceX.Size -- [Luau] may have loaded glyphs
            end

            if s >= word_wrap_eol then
                if text_size.x < line_width then
                    text_size.x = line_width
                end
                text_size.y = text_size.y + line_height
                line_width = 0.0
                s = ImTextCalcWordWrapNextLineStart(text, s, text_end, flags) -- Wrapping skips upcoming blanks
                if bit32.band(flags, ImDrawTextFlags.StopOnNewLine) ~= 0 then
                    stop = true; break
                end
                word_wrap_eol = nil

                break
            end
        end

        -- Decode and advance source
        local prev_s = s
        local c
        if text_is_str then c = string.byte(text, s) else c = text[s] end -- [Luau] ImStrByte() inlined
        if c < 0x80 then
            s = s + 1
        else
            local wanted, out_char = ImStd.ImTextCharFromUtf8(text, s, text_end)
            c = out_char
            s = s + wanted
        end

        if c == 10 then -- '\n'
            text_size.x = ImMax(text_size.x, line_width)
            text_size.y = text_size.y + line_height
            line_width = 0.0
            if bit32.band(flags, ImDrawTextFlags.StopOnNewLine) ~= 0 then
                stop = true; break
            end

            break
        end

        if c == 13 then -- '\r'
            break
        end

        -- Optimized inline version of 'float char_width = GetCharAdvance((ImWchar)c);'
        local char_width = (c < adv_n) and adv_data[c + 1] or -1.0
        if (char_width < 0.0) then
            char_width = BuildLoadGlyphGetAdvanceOrFallback(baked, c)
            adv_data, adv_n = baked.IndexAdvanceX.Data, baked.IndexAdvanceX.Size
        end
        char_width = char_width * scale

        if (line_width + char_width >= max_width) then
            s = prev_s
            stop = true; break
        end

        line_width = line_width + char_width

        until true
        if stop then break end
    end

    if (text_size.x < line_width) then
        text_size.x = line_width
    end

    if out_offset then -- offset allow for the possibility of sitting after a trailing \n
        out_offset.x = line_width
        out_offset.y = text_size.y + line_height
    end

    if (line_width > 0 or text_size.y == 0.0) then -- whereas size.y will ignore the trailing \n
        text_size.y = text_size.y + line_height
    end

    local out_remaining = s

    if cache_key then
        baked._TextSizeCache[cache_key] = { text_size.x / scale, text_size.y / line_height }
        baked._TextSizeCacheN = baked._TextSizeCacheN + 1
    elseif wrap_cache then
        wrap_cache[text] = { text_size.x, text_size.y, out_remaining }
        baked._TextSizeCacheN = baked._TextSizeCacheN + 1
    end

    return text_size, out_remaining
end

--- @param size       float
--- @param max_width  float
--- @param wrap_width float
--- @param text       ImString
--- @param text_begin int
--- @param text_end?  int
function MT.ImFont:CalcTextSizeA(size, max_width, wrap_width, text, text_begin, text_end)
    return ImFontCalcTextSizeEx(self, size, max_width, wrap_width, text, text_begin, text_end, text_end, nil, ImDrawTextFlags.None)
end

--- Note: as with every ImDrawList drawing function, this expects that the font atlas texture is bound.
--- @param draw_list     ImDrawList
--- @param size          float
--- @param pos           ImVec2
--- @param col           ImU32
--- @param c             ImWchar
--- @param cpu_fine_clip ImVec4
local RenderChar_a, RenderChar_c, RenderChar_uv_a, RenderChar_uv_c = ImVec2(), ImVec2(), ImVec2(), ImVec2()

function MT.ImFont:RenderChar(draw_list, size, pos, col, c, cpu_fine_clip)
    local baked = self:GetFontBaked(size)
    local glyph = baked:FindGlyph(c)
    if not glyph or not glyph.Visible then
        return
    end
    if glyph.Colored then
        col = bit32.bor(col, bit32.bnot(IM_COL32_A_MASK))
    end

    local scale
    if size >= 0.0 then
        scale = size / baked.Size
    else
        scale = 1.0
    end

    local x = pos.x
    local y = pos.y
    if bit32.band(draw_list.Flags, ImDrawListFlags.TextNoPixelSnap) == 0 then
        x = IM_TRUNC(x)
        y = IM_TRUNC(y)
    end

    local x1 = x + glyph.X0 * scale
    local x2 = x + glyph.X1 * scale
    if cpu_fine_clip and (x1 > cpu_fine_clip.z or x2 < cpu_fine_clip.x) then
        return
    end

    local y1 = y + glyph.Y0 * scale
    local y2 = y + glyph.Y1 * scale
    local u1 = glyph.U0
    local v1 = glyph.V0
    local u2 = glyph.U1
    local v2 = glyph.V1

    -- Always CPU fine clip. Code extracted from RenderText().
    -- CPU side clipping used to fit text in their frame when the frame is too small. Only does clipping for axis aligned quads.
    if cpu_fine_clip then
        if x1 < cpu_fine_clip.x then u1 = u1 + (1.0 - (x2 - cpu_fine_clip.x) / (x2 - x1)) * (u2 - u1); x1 = cpu_fine_clip.x end
        if y1 < cpu_fine_clip.y then v1 = v1 + (1.0 - (y2 - cpu_fine_clip.y) / (y2 - y1)) * (v2 - v1); y1 = cpu_fine_clip.y end
        if x2 > cpu_fine_clip.z then u2 = u1 + ((cpu_fine_clip.z - x1) / (x2 - x1)) * (u2 - u1); x2 = cpu_fine_clip.z end
        if y2 > cpu_fine_clip.w then v2 = v1 + ((cpu_fine_clip.w - y1) / (y2 - y1)) * (v2 - v1); y2 = cpu_fine_clip.w end
        if y1 >= y2 then return end
    end
    draw_list:PrimReserve(6, 4)
    -- [Luau] scratch vectors, PrimRectUV() only reads them
    local a, c, uv_a, uv_c = RenderChar_a, RenderChar_c, RenderChar_uv_a, RenderChar_uv_c
    a.x = x1; a.y = y1; c.x = x2; c.y = y2; uv_a.x = u1; uv_a.y = v1; uv_c.x = u2; uv_c.y = v2
    draw_list:PrimRectUV(a, c, uv_a, uv_c, col)
end

function MT.ImFontAtlas:AddFont(font_cfg_in)
    -- Sanity Checks
    IM_ASSERT(not self.Locked, "Cannot modify a locked ImFontAtlas!")
    IM_ASSERT((font_cfg_in.FontData ~= nil and font_cfg_in.FontDataSize > 0) or (font_cfg_in.FontLoader ~= nil))
    IM_ASSERT(font_cfg_in.SizePixels > 0.0, "Is ImFontConfig struct correctly initialized?")
    IM_ASSERT(font_cfg_in.RasterizerDensity > 0.0, "Is ImFontConfig struct correctly initialized?")

    if font_cfg_in.GlyphOffset.x ~= 0.0 or font_cfg_in.GlyphOffset.y ~= 0.0 or
        font_cfg_in.GlyphMinAdvanceX ~= 0.0 or font_cfg_in.GlyphMaxAdvanceX ~= FLT_MAX then
        IM_ASSERT(font_cfg_in.SizePixels ~= 0.0,
            "Specifying glyph offset/advances requires a reference size to base it on.")
    end

    -- Lazily create builder on the first call to AddFont
    if self.Builder == nil then
        ImFontAtlasBuildInit(self)
    end

    -- Create new font
    local is_first_font = (self.Fonts.Size == 0)
    local font
    if not font_cfg_in.MergeMode then
        font = ImFont()
        font.FontId = self.FontNextUniqueID
        self.FontNextUniqueID = self.FontNextUniqueID + 1
        font.Flags = font_cfg_in.Flags
        font.LegacySize = font_cfg_in.SizePixels
        font.CurrentRasterizerDensity = font_cfg_in.RasterizerDensity
        self.Fonts:push_back(font)
    else
        IM_ASSERT(self.Fonts.Size > 0, "Cannot use MergeMode for the first font!") -- When using MergeMode make sure that a font has already been added before.
        font = (font_cfg_in.DstFont ~= nil) and font_cfg_in.DstFont or self.Fonts:back()
        ImFontAtlasFontDiscardBakes(self, font, 0) -- Need to discard bakes if the font was already used, because baked->FontLoaderDatas[] will change size. (#9162)
    end

    -- Add to list
    self.Sources:push_back(font_cfg_in)
    local font_cfg = self.Sources:back()
    if (font_cfg.DstFont == nil) then
        font_cfg.DstFont = font
    end
    font.Sources:push_back(font_cfg)
    ImFontAtlasBuildUpdatePointers(self)

    -- Sanity check
    -- We don't round cfg.SizePixels yet as relative size of merged fonts are used afterwards.
    if font_cfg.GlyphExcludeRanges ~= nil then
        local size = 0
        for _, v in ipairs(font_cfg.GlyphExcludeRanges) do if v == 0 then break end size = size + 1 end
        IM_ASSERT(bit32.band(size, 1) == 0, "GlyphExcludeRanges[] size must be multiple of two!")
        IM_ASSERT(size <= 64, "GlyphExcludeRanges[] size must be small!")
    end

    if font_cfg.FontLoader ~= nil then
        IM_ASSERT(font_cfg.FontLoader.FontBakedLoadGlyph ~= nil)
        IM_ASSERT(font_cfg.FontLoader.LoaderInit == nil and font_cfg.FontLoader.LoaderShutdown == nil) -- FIXME-NEWATLAS: Unsupported yet.
    end
    --                             | Target w/ Implicit RefSize | Target w/ Explicit RefSize |
    -- Adding w/ Implicit RefSize: | OK (same scale)            | OK (same scale)            |
    -- Adding w/ Explicit RefSize: | KO                         | OK (custom scale)          |
    if font_cfg_in.MergeMode and font_cfg_in.SizePixels > 0 then
        IM_ASSERT(bit32.band(font.Flags, ImFontFlags.ImplicitRefSize) == 0, "Cannot use MergeMode with an explicit reference size when the destination font used an implicit reference size!")
    end
    IM_ASSERT(font_cfg.FontLoaderData == nil)

    if not ImFontAtlasFontSourceInit(self, font_cfg) then
        -- Rollback (this is a fragile/rarely exercised code-path. TestSuite's "misc_atlas_add_invalid_font" aim to test this)
        ImFontAtlasFontDestroySourceData(self, font_cfg)
        self.Sources:pop_back()
        font.Sources:pop_back()
        if not font_cfg.MergeMode then
            font = nil
            self.Fonts:pop_back()
        end
        return nil
    end
    ImFontAtlasFontSourceAddToFont(self, font, font_cfg)

    if (is_first_font) then
        ImFontAtlasBuildNotifySetFont(self, nil, font)
    end

    return font
end

-- This duplicates some of the logic in UpdateFontsNewFrame() which is a bit chicken-and-eggy/tricky to extract due to variety of codepaths and possible initialization ordering.
--- @param ctx ImGuiContext
--- @return float
local function GetExpectedContextFontSize(ctx)
    return ((ctx.Style.FontSizeBase > 0.0) and ctx.Style.FontSizeBase or 13.0) * ctx.Style.FontScaleMain * ctx.Style.FontScaleDpi
end

-- Legacy function with heuristic to select Pixel or Vector font.
-- The selection is based on (style.FontSizeBase * style.FontScaleMain * style.FontScaleDpi) reaching a small threshold at the time of adding the default font.
-- Prefer calling AddFontDefaultVector() or AddFontDefaultBitmap() based on your own logic.
--- @param font_cfg ImFontConfig
function MT.ImFontAtlas:AddFontDefault(font_cfg)
    if self.OwnerContext == nil or GetExpectedContextFontSize(self.OwnerContext) >= 15.0 then
        return self:AddFontDefaultVector(font_cfg)
    else
        return self:AddFontDefaultBitmap(font_cfg)
    end
end

function MT.ImFontAtlas:AddFontFromMemoryTTF(font_data, font_data_size, size_pixels, font_cfg_template, glyph_ranges)
    IM_ASSERT(not self.Locked, "Cannot modify a locked ImFontAtlas!")
    local font_cfg = font_cfg_template and font_cfg_template or ImFontConfig()
    IM_ASSERT(font_cfg.FontData == nil)
    IM_ASSERT(font_data_size > 100, "Incorrect value for font_data_size!") -- Heuristic to prevent accidentally passing a wrong value to font_data_size.
    font_cfg.FontData = font_data
    font_cfg.FontDataSize = font_data_size
    font_cfg.SizePixels = (size_pixels > 0.0) and size_pixels or font_cfg.SizePixels
    if glyph_ranges then
        font_cfg.GlyphRanges = glyph_ranges
    end
    return self:AddFont(font_cfg)
end

-- TODO: GetDefaultCompressedFontDataProggyClean, GetDefaultCompressedFontDataProggyForever
function MT.ImFontAtlas:AddFontFromMemoryCompressedTTF()
    -- TODO:
end

function MT.ImFontAtlas:AddFontFromFileTTF(filename, size_pixels, font_cfg_template, glyph_ranges)
    IM_ASSERT(not self.Locked, "Cannot modify a locked ImFontAtlas!")

    local data, data_size = ImStd.ImFileLoadToMemory(filename, "rb")
    if not data then
        if (font_cfg_template == nil or (bit32.band(font_cfg_template.Flags, ImFontFlags.NoLoadError) == 0)) then
            -- IMGUI_DEBUG_LOG("While loading '%s'\n", filename)
            IM_ASSERT_USER_ERROR(0, "Could not load font file!")
        end

        return nil
    end

    local font_cfg = font_cfg_template and font_cfg_template or ImFontConfig()
    if not font_cfg.Name or font_cfg.Name == "" then
        -- Store a short copy of filename into the font name for convenience
        for i = #filename, 1, -1 do
            local c = string.byte(filename, i, i)
            if (c == 47 or c == 92) then -- '/' or '\\'
                font_cfg.Name = string.sub(filename, i + 1)
                break
            end
        end
    end

    return self:AddFontFromMemoryTTF(data, data_size, size_pixels, font_cfg, glyph_ranges)
end

function GetDefaultFontDataProggyClean()
    return ImStd.ImFileLoadToMemory("fonts/ProggyClean.ttf", "rb")
end

function GetDefaultFontDataProggyForever()
    return ImStd.ImFileLoadToMemory("fonts/ProggyForever.ttf", "rb")
end

-- TODO: IMGUI_DISABLE_DEFAULT_FONT, IMGUI_DISABLE_DEFAULT_FONT_BITMAP
-- Load ProggyClean.ttf. Default size 13, disable oversampling.
-- If you want a similar font which may be better scaled, consider using AddFontDefaultVector().
--- @param font_cfg_template ImFontConfig
function MT.ImFontAtlas:AddFontDefaultBitmap(font_cfg_template)
    local font_cfg = font_cfg_template and font_cfg_template or ImFontConfig()
    if not font_cfg_template then
        font_cfg.PixelSnapH = true -- Prevents sub-integer scaling factors at lower-level layers.
    end
    if font_cfg.SizePixels <= 0.0 then
        font_cfg.SizePixels = 13.0 -- This only serves (1) as a reference for GlyphOffset.y setting and (2) as a default for pre-1.92 backend.
        font_cfg.Flags = bit32.bor(font_cfg.Flags, ImFontFlags.ImplicitRefSize)
    end
    if not font_cfg.Name or font_cfg.Name == "" then
        font_cfg.Name = "ProggyClean.ttf"
    end
    font_cfg.EllipsisChar = 0x0085
    font_cfg.GlyphOffset.y = font_cfg.GlyphOffset.y +  1.0 * (font_cfg.SizePixels / 13.0) -- Add +1 offset per 13 units

    local ttf_data, ttf_data_size = GetDefaultFontDataProggyClean()
    return self:AddFontFromMemoryTTF(ttf_data, ttf_data_size, font_cfg.SizePixels, font_cfg)
end

-- Load a minimal version of ProggyForever, designed to match our good old ProggyClean, but nicely scalable.
-- (See build script in https://github.com/ocornut/proggyforever for details)
--- @param font_cfg_template ImFontConfig
function MT.ImFontAtlas:AddFontDefaultVector(font_cfg_template)
    local font_cfg = font_cfg_template and font_cfg_template or ImFontConfig()
    if not font_cfg_template then
        font_cfg.PixelSnapH = true -- Precisely match ProggyClean, but prevents sub-integer scaling factors at lower-level layers.
    end
    if font_cfg.SizePixels <= 0.0 then
        font_cfg.SizePixels = 13.0
        font_cfg.Flags = bit32.bor(font_cfg.Flags, ImFontFlags.ImplicitRefSize)
    end
    if not font_cfg.Name or font_cfg.Name == "" then
        font_cfg.Name = "ProggyForever.ttf"
    end
    font_cfg.ExtraSizeScale = font_cfg.ExtraSizeScale * 1.015 -- Match ProggyClean
    font_cfg.GlyphOffset.y = font_cfg.GlyphOffset.y + 0.5 * (font_cfg.SizePixels / 16.0) -- Closer match ProggyClean + avoid descenders going too high (with current code).

    local ttf_data, ttf_data_size = GetDefaultFontDataProggyForever()
    return self:AddFontFromMemoryTTF(ttf_data, ttf_data_size, font_cfg.SizePixels, font_cfg)
end

function MT.ImFontAtlas:GetCustomRect(id, out_r)
    local r = ImFontAtlasPackGetRectSafe(self, id)
    if r == nil then
        return false
    end
    IM_ASSERT(self.TexData.Width > 0 and self.TexData.Height > 0) -- Font atlas needs to be built before we can calculate UV coordinates
    if out_r == nil then
        return true
    end
    out_r.x = r.x
    out_r.y = r.y
    out_r.w = r.w
    out_r.h = r.h
    ImVec2_Copy(out_r.uv0, ImVec2((r.x), (r.y)) * self.TexUvScale)
    ImVec2_Copy(out_r.uv1, ImVec2((r.x + r.w), (r.y + r.h)) * self.TexUvScale)

    return true
end

--- @param atlas         ImFontAtlas
--- @param cursor_type   ImGuiMouseCursor
--- @param out_offset    ImVec2
--- @param out_size      ImVec2
--- @param out_uv_border ImVec2[]
--- @param out_uv_fill   ImVec2[]
function ImFontAtlasGetMouseCursorTexData(atlas, cursor_type, out_offset, out_size, out_uv_border, out_uv_fill)
    if cursor_type <= ImGuiMouseCursor.None or cursor_type >= ImGuiMouseCursor.COUNT then
        return false
    end
    if bit32.band(atlas.Flags, ImFontAtlasFlags.NoMouseCursors) ~= 0 then
        return false
    end

    local r = ImFontAtlasPackGetRect(atlas, atlas.Builder.PackIdMouseCursors)
    local pos = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type + 1][1] + ImVec2(r.x, r.y)
    local size = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type + 1][2]
    ImVec2_Copy(out_size, size)
    ImVec2_Copy(out_offset, FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type + 1][3])
    ImVec2_Copy(out_uv_border[1], (pos) * atlas.TexUvScale)
    ImVec2_Copy(out_uv_border[2], (pos + size) * atlas.TexUvScale)
    pos.x = pos.x + (FONT_ATLAS_DEFAULT_TEX_DATA_W + 1)
    ImVec2_Copy(out_uv_fill[1], (pos) * atlas.TexUvScale)
    ImVec2_Copy(out_uv_fill[2], (pos + size) * atlas.TexUvScale)

    return true
end

-- At it is common to do an AddCustomRect() followed by a GetCustomRect(), we provide an optional 'out_r' argument to retrieve the info straight away.
function MT.ImFontAtlas:AddCustomRect(width, height, out_r)
    IM_ASSERT(width > 0 and width <= 0xFFFF)
    IM_ASSERT(height > 0 and height <= 0xFFFF)

    if (self.Builder == nil) then
        ImFontAtlasBuildInit(self)
    end

    local r_id = ImFontAtlasPackAddRect(self, width, height)
    if (r_id == ImFontAtlasRectId_Invalid) then
        return ImFontAtlasRectId_Invalid
    end
    if (out_r ~= nil) then
        self:GetCustomRect(r_id, out_r)
    end

    if (self.RendererHasTextures) then
        local r = ImFontAtlasPackGetRect(self, r_id)
        ImFontAtlasTextureBlockQueueUpload(self, self.TexData, r.x, r.y, r.w, r.h)
    end

    return r_id
end

local function IM_NORMALIZE2F_OVER_ZERO(VX, VY)
    local d2 = VX * VX + VY * VY
    if d2 > 0.0 then
        local inv_len = ImRsqrt(d2)
        VX = VX * inv_len
        VY = VY * inv_len
    end
    return VX, VY
end

local function IM_FIXNORMAL2F(VX, VY)
    local IM_FIXNORMAL2F_MAX_INVLEN2 = 100 -- 500.0f (see #4053, #3366)

    local d2 = VX * VX + VY * VY
    if d2 > 0.000001 then
        local inv_len2 = 1.0 / d2
        if inv_len2 > IM_FIXNORMAL2F_MAX_INVLEN2 then
            inv_len2 = IM_FIXNORMAL2F_MAX_INVLEN2
        end
        VX = VX * inv_len2
        VY = VY * inv_len2
    end
    return VX, VY
end

-------------------------------------------------------------------------------
-- [SECTION] ImDrawData
-------------------------------------------------------------------------------

function MT.ImDrawData:Clear()
    self.Valid = false
    self.FrameCount = 0; self.TotalIdxCount = 0; self.TotalVtxCount = 0
    self.CmdLists:resize(0) -- The ImDrawList are NOT owned by ImDrawData but e.g. by ImGuiContext, so we don't clear them.
    self.DisplayPos       = ImVec2(0.0, 0.0)
    self.DisplaySize      = ImVec2(0.0, 0.0)
    self.FramebufferScale = ImVec2(0.0, 0.0)
    self.OwnerViewport    = nil
    self.Textures         = nil
end

-- Important: 'out_list' is generally going to be draw_data.CmdLists, but may be another temporary list
-- as long at it is expected that the result will be later merged into draw_data.CmdLists[].
function ImGui.AddDrawListToDrawDataEx(draw_data, out_list, draw_list)
    if draw_list.CmdBuffer.Size == 0 then
        return
    end
    if draw_list.CmdBuffer.Size == 1 and draw_list.CmdBuffer.Data[1].ElemCount == 0 and draw_list.CmdBuffer.Data[1].UserCallback == nil then
        return
    end

    -- Draw list sanity check. Detect mismatch between PrimReserve() calls and incrementing _VtxCurrentIdx, _VtxWritePtr etc.
    -- May trigger for you if you are using PrimXXX functions incorrectly.
    IM_ASSERT(draw_list.VtxBuffer.Size == 0 or draw_list._VtxWritePtr == draw_list.VtxBuffer.Size + 1)
    IM_ASSERT(draw_list.IdxBuffer.Size == 0 or draw_list._IdxWritePtr == draw_list.IdxBuffer.Size + 1)
    if (bit32.band(draw_list.Flags, ImDrawListFlags.AllowVtxOffset) == 0) then
        IM_ASSERT(draw_list._VtxCurrentIdx == draw_list.VtxBuffer.Size + 1)
    end

    -- Add to output list + records state in ImDrawData
    out_list:push_back(draw_list)
    draw_data.TotalVtxCount = draw_data.TotalVtxCount + draw_list.VtxBuffer.Size
    draw_data.TotalIdxCount = draw_data.TotalIdxCount + draw_list.IdxBuffer.Size
end

function MT.ImDrawData:AddDrawList(draw_list)
    draw_list:_PopUnusedDrawCmd()
    ImGui.AddDrawListToDrawDataEx(self, self.CmdLists, draw_list)
end

local IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN = 4
local IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX = 512

local function IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(_RAD, _MAXERROR) return ImClamp(IM_ROUNDUP_TO_EVEN(ImCeil(IM_PI / ImAcos(1 - ImMin(_MAXERROR, _RAD) / _RAD))), IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN, IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX) end
local function IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC_R(_N, _MAXERROR) return (_MAXERROR / (1 - ImCos(IM_PI / ImMax(_N, IM_PI)))) end
local function IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC_ERROR(_N, _RAD)  return ((1 - ImCos(IM_PI / ImMax(_N, IM_PI))) / _RAD) end

-------------------------------------------------------------------------------
-- [SECTION] ImDrawList
-------------------------------------------------------------------------------

function MT.ImDrawListSharedData:SetCircleTessellationMaxError(max_error)
    if self.CircleTessellationMaxError == max_error then
        return
    end

    IM_ASSERT(max_error > 0)

    self.CircleTessellationMaxError = max_error
    for i = 1, 64 do -- IM_COUNTOF(CircleSegmentCounts)
        local radius = (i - 1)
        self.CircleSegmentCounts[i] = (i > 1) and IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(radius, self.CircleTessellationMaxError) or IM_DRAWLIST_ARCFAST_SAMPLE_MAX
    end

    self.ArcFastRadiusCutoff = IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC_R(IM_DRAWLIST_ARCFAST_SAMPLE_MAX, self.CircleTessellationMaxError)
end

--- @param data ImDrawListSharedData
function MT.ImDrawList:_SetDrawListSharedData(data)
    if self._Data ~= nil then
        self._Data.DrawLists:find_erase_unsorted(self)
    end
    self._Data = data
    if self._Data ~= nil then
        self._Data.DrawLists:push_back(self)
    end
end

-- Initialize before use in a new frame. We always have a command ready in the buffer.
-- In the majority of cases, you would want to call PushClipRect() and PushTexture() after this.
-- TODO:
function MT.ImDrawList:_ResetForNewFrame()
    self._ContentClipX0 = nil -- set again by Begin() (Roblox backend scroll reuse)
    if self._Splitter._Count > 1 then
        self._Splitter:Merge(self)
    end
    self._Splitter._Current = 0 -- [Lua] recover from an error thrown mid-split
    self._Splitter._Count = 1

    self.CmdBuffer:resize(0)
    self.IdxBuffer:resize(0)
    self.VtxBuffer:resize(0)
    self.Flags = self._Data.InitialFlags

    self._CmdHeader = ImDrawCmdHeader() -- memset(&_CmdHeader, 0, sizeof(_CmdHeader))

    self._VtxCurrentIdx = 1
    self._VtxWritePtr = 1
    self._IdxWritePtr = 1
    self._ClipRectStack:resize(0)
    self._TextureStack:resize(0)
    self._Path:resize(0)

    self.CmdBuffer:push_back(ImDrawCmd())

    self._FringeScale = self._Data.InitialFringeScale
end

function MT.ImDrawList:_ClearFreeMemory()
    self.CmdBuffer:clear()
    self.IdxBuffer:clear()
    self.VtxBuffer:clear()

    self.Flags = ImDrawListFlags.None

    self._VtxCurrentIdx = 1
    self._VtxWritePtr = 1
    self._IdxWritePtr = 1

    self._ClipRectStack:clear()
    self._TextureStack:clear()
    -- self._CallbacksDataBuf:clear()
    self._Path:clear()
    self._Splitter:ClearFreeMemory()
end

function MT.ImDrawList:AddDrawCmd()
    local draw_cmd = ImDrawCmd()

    ImVec4_Copy(draw_cmd.ClipRect, self._CmdHeader.ClipRect) -- Same as calling ImDrawCmd_HeaderCopy()
    draw_cmd.TexRef = self._CmdHeader.TexRef
    draw_cmd.VtxOffset = self._CmdHeader.VtxOffset
    draw_cmd.IdxOffset = self.IdxBuffer.Size

    IM_ASSERT(draw_cmd.ClipRect.x <= draw_cmd.ClipRect.z and draw_cmd.ClipRect.y <= draw_cmd.ClipRect.w)
    -- [Luau] inline self.CmdBuffer:push_back(draw_cmd)
    local cmd_buffer = self.CmdBuffer
    local n = cmd_buffer.Size + 1
    if n > cmd_buffer.Capacity then cmd_buffer:push_back(draw_cmd) else cmd_buffer.Data[n] = draw_cmd; cmd_buffer.Size = n end
end

-- Pop trailing draw command (used before merging or presenting to user)
-- Note that this leaves the ImDrawList in a state unfit for further commands, as most code assume that CmdBuffer.Size > 0 && CmdBuffer.back().UserCallback == nil
function MT.ImDrawList:_PopUnusedDrawCmd()
    while self.CmdBuffer.Size > 0 do
        local curr_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size]
        if curr_cmd.ElemCount ~= 0 or curr_cmd.UserCallback ~= nil then
            break -- return;// break;
        end

        self.CmdBuffer:pop_back()
    end
end

--- @param callback       ImDrawCallback
--- @param userdata       any
--- @param userdata_size? size_t
function MT.ImDrawList:AddCallback(callback, userdata, userdata_size)
    if userdata_size == nil then userdata_size = 0 end

    IM_ASSERT(callback ~= nil)
    IM_ASSERT_PARANOID(self.CmdBuffer.Size > 0)

    local curr_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size]
    IM_ASSERT(curr_cmd.UserCallback == nil)
    if curr_cmd.ElemCount ~= 0 then
        self:AddDrawCmd()
        curr_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size]
    end
    curr_cmd.UserCallback = callback
    -- TODO: _CallbacksDataBuf?
    if userdata_size == 0 then
        -- Store user data directly in command (no indirection)
        curr_cmd.UserCallbackData = userdata

    else
        IM_ASSERT(userdata ~= nil)
        IM_ASSERT(userdata_size < bit32.lshift(1, 31))

    end

    self:AddDrawCmd() -- Force a new command after us (see comment below)
end

--- Compare ClipRect, TexRef, VtxOffset
--- @param CMD_LHS ImDrawCmd|ImDrawCmdHeader
--- @param CMD_RHS ImDrawCmd|ImDrawCmdHeader
--- @return bool
local function ImDrawCmd_HeaderCompare(CMD_LHS, CMD_RHS)
    local lcr, rcr = CMD_LHS.ClipRect, CMD_RHS.ClipRect -- [Luau] cache
    if lcr.x ~= rcr.x or
        lcr.y ~= rcr.y or
        lcr.z ~= rcr.z or
        lcr.w ~= rcr.w then
        return false
    end

    local ltex, rtex = CMD_LHS.TexRef, CMD_RHS.TexRef
    if ltex ~= rtex and (ltex._TexData ~= rtex._TexData or
        ltex._TexID ~= rtex._TexID) then
        return false
    end

    if CMD_LHS.VtxOffset ~= CMD_RHS.VtxOffset then
        return false
    end

    return true
end

--- Copy ClipRect, TexRef, VtxOffset
--- @param CMD_DST ImDrawCmd|ImDrawCmdHeader
--- @param CMD_SRC ImDrawCmd|ImDrawCmdHeader
local function ImDrawCmd_HeaderCopy(CMD_DST, CMD_SRC)
    CMD_DST.ClipRect.x = CMD_SRC.ClipRect.x
    CMD_DST.ClipRect.y = CMD_SRC.ClipRect.y
    CMD_DST.ClipRect.z = CMD_SRC.ClipRect.z
    CMD_DST.ClipRect.w = CMD_SRC.ClipRect.w

    CMD_DST.TexRef._TexData = CMD_SRC.TexRef._TexData
    CMD_DST.TexRef._TexID = CMD_SRC.TexRef._TexID

    CMD_DST.VtxOffset = CMD_SRC.VtxOffset
end

--- @param CMD_0 ImDrawCmd
--- @param CMD_1 ImDrawCmd
local function ImDrawCmd_AreSequentialIdxOffset(CMD_0, CMD_1)
    return CMD_0.IdxOffset + CMD_0.ElemCount == CMD_1.IdxOffset
end

-- Try to merge two last draw commands
function MT.ImDrawList:_TryMergeDrawCmds()
    IM_ASSERT_PARANOID(self.CmdBuffer.Size > 0)
    local curr_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size]
    local prev_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size - 1]
    if ImDrawCmd_HeaderCompare(curr_cmd, prev_cmd) and ImDrawCmd_AreSequentialIdxOffset(prev_cmd, curr_cmd) and curr_cmd.UserCallback == nil and prev_cmd.UserCallback == nil then
        prev_cmd.ElemCount = prev_cmd.ElemCount + curr_cmd.ElemCount
        self.CmdBuffer:pop_back()
    end
end

-- Our scheme may appears a bit unusual, basically we want the most-common calls AddLine AddRect etc. to not have to perform any check so we always have a command ready in the stack.
-- The cost of figuring out if a new command has to be added or if we can merge is paid in those Update** functions only.
function MT.ImDrawList:_OnChangedClipRect()
    -- If current command is used with different settings we need to add a new command
    IM_ASSERT_PARANOID(self.CmdBuffer.Size > 0)
    local curr_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size]
    if curr_cmd.ElemCount ~= 0 then
        -- [Luau] inline IM_VEC4.__eq
        local hcr, ccr = self._CmdHeader.ClipRect, curr_cmd.ClipRect
        if hcr.x ~= ccr.x or hcr.y ~= ccr.y or hcr.z ~= ccr.z or hcr.w ~= ccr.w then
            self:AddDrawCmd()

            return
        end
    end

    IM_ASSERT(curr_cmd.UserCallback == nil)

    -- Try to merge with previous command if it matches, else use current command
    local prev_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size - 1]
    if (curr_cmd.ElemCount == 0 and self.CmdBuffer.Size > 1 and ImDrawCmd_HeaderCompare(self._CmdHeader, prev_cmd) and ImDrawCmd_AreSequentialIdxOffset(prev_cmd, curr_cmd) and prev_cmd.UserCallback == nil) then
        self.CmdBuffer:pop_back()

        return
    end

    ImVec4_Copy(curr_cmd.ClipRect, self._CmdHeader.ClipRect)
end

function MT.ImDrawList:_OnChangedTexture()
    -- If current command is used with different settings we need to add a new command
    IM_ASSERT_PARANOID(self.CmdBuffer.Size > 0)
    local curr_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size]
    if curr_cmd.ElemCount ~= 0 and curr_cmd.TexRef ~= self._CmdHeader.TexRef then
        self:AddDrawCmd()

        return
    end

    -- Unlike other _OnChangedXXX functions this may be called by ImFontAtlasUpdateDrawListsTextures() in more locations so we need to handle this case.
    if curr_cmd.UserCallback ~= nil then
        return
    end

    -- Try to merge with previous command if it matches, else use current command
    local prev_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size - 1]
    if curr_cmd.ElemCount == 0 and self.CmdBuffer.Size > 1 and ImDrawCmd_HeaderCompare(self._CmdHeader, prev_cmd) and ImDrawCmd_AreSequentialIdxOffset(prev_cmd, curr_cmd) and prev_cmd.UserCallback == nil then
        self.CmdBuffer:pop_back()

        return
    end

    curr_cmd.TexRef = self._CmdHeader.TexRef
end

function MT.ImDrawList:_OnChangedVtxOffset()
    -- We don't need to compare curr_cmd.VtxOffset ~= _CmdHeader.VtxOffset because we know it'll be different at the time we call this.
    self._VtxCurrentIdx = 1
    IM_ASSERT_PARANOID(self.CmdBuffer.Size > 0)

    local curr_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size]
    --IM_ASSERT(curr_cmd.VtxOffset ~= self._CmdHeader.VtxOffset) -- See #3349
    if curr_cmd.ElemCount ~= 0 then
        self:AddDrawCmd()
        return
    end
    IM_ASSERT(curr_cmd.UserCallback == nil)
    curr_cmd.VtxOffset = self._CmdHeader.VtxOffset
end

-------------------------------------------------------------------------------
-- [SECTION] ImDrawListSplitter
-------------------------------------------------------------------------------
-- FIXME: This may be a little confusing, trying to be a little too low-level/optimal instead of just doing vector swap..
-------------------------------------------------------------------------------
-- Lua: channels swap ImVector objects with the draw list (C++ memcpy of the vector headers).
-- Channel 0 holds nothing while it is the current channel (its buffers live in the draw list).

-- Copy ClipRect, TexRef, VtxOffset (TexRef is assigned by reference, never mutated)
local function ImDrawCmd_HeaderCopyRef(dst, src)
    ImVec4_Copy(dst.ClipRect, src.ClipRect)
    dst.TexRef = src.TexRef
    dst.VtxOffset = src.VtxOffset
end

function MT.ImDrawListSplitter:Clear()
    self._Current = 0
    self._Count = 1
end

function MT.ImDrawListSplitter:ClearFreeMemory()
    for i = 1, self._Channels.Size do
        local ch = self._Channels.Data[i]
        if i - 1 == self._Current then
            -- Current channel is a copy of CmdBuffer/IdxBuffer, don't destruct again
            self._Channels.Data[i] = ImDrawChannel()
        else
            ch._CmdBuffer:clear()
            ch._IdxBuffer:clear()
        end
    end
    self._Current = 0
    self._Count = 1
    self._Channels:clear()
end

--- @param draw_list      ImDrawList
--- @param channels_count int
function MT.ImDrawListSplitter:Split(draw_list, channels_count)
    IM_ASSERT(self._Current == 0 and self._Count <= 1, "Nested channel splitting is not supported. Please use separate instances of ImDrawListSplitter.")
    local old_channels_count = self._Channels.Size
    if old_channels_count < channels_count then
        self._Channels:reserve(channels_count) -- Avoid over reserving since this is likely to stay stable
        self._Channels:resize(channels_count)
    end
    self._Count = channels_count

    -- Channels[] hold storage that we'll swap with draw_list._CmdBuffer/_IdxBuffer
    -- The content of Channels[0] at this point doesn't matter. We clear it to make state tidy in a debugger but we don't strictly need to.
    -- When we switch to the next channel, we'll copy draw_list._CmdBuffer/_IdxBuffer into Channels[0] and then Channels[1] into draw_list.CmdBuffer/_IdxBuffer
    -- Channel 0 is the draw list itself (memset to 0 in C++)
    local channels = self._Channels.Data
    channels[1] = { _CmdBuffer = nil, _IdxBuffer = nil }
    for i = 2, channels_count do
        if i > old_channels_count or channels[i] == nil then
            channels[i] = ImDrawChannel()
        else
            channels[i]._CmdBuffer.Size = 0 -- [Luau] inline resize(0)
            channels[i]._IdxBuffer.Size = 0
        end
    end
end

--- @param draw_list ImDrawList
function MT.ImDrawListSplitter:Merge(draw_list)
    -- Note that we never use or rely on _Channels.Size because it is merely a buffer that we never shrink back to 0 to keep all sub-buffers ready for use.
    if self._Count <= 1 then
        return
    end

    self:SetCurrentChannel(draw_list, 0)
    draw_list:_PopUnusedDrawCmd()

    -- Calculate our final buffer sizes. Also fix the incorrect IdxOffset values in each command.
    local new_cmd_buffer_count = 0
    local new_idx_buffer_count = 0
    local last_cmd = (self._Count > 0 and draw_list.CmdBuffer.Size > 0) and draw_list.CmdBuffer.Data[draw_list.CmdBuffer.Size] or nil
    local idx_offset = last_cmd and (last_cmd.IdxOffset + last_cmd.ElemCount) or 0
    local channels = self._Channels.Data
    for i = 2, self._Count do
        local ch = channels[i]
        local cmds = ch._CmdBuffer
        if cmds.Size > 0 and cmds.Data[cmds.Size].ElemCount == 0 and cmds.Data[cmds.Size].UserCallback == nil then -- Equivalent of PopUnusedDrawCmd()
            cmds:pop_back()
        end

        if cmds.Size > 0 and last_cmd ~= nil then
            -- Do not include ImDrawCmd_AreSequentialIdxOffset() in the compare as we rebuild IdxOffset values ourselves.
            -- Manipulating IdxOffset (e.g. by reordering draw commands like done by RenderDimmedBackgroundBehindWindow()) is not supported within a splitter.
            local next_cmd = cmds.Data[1]
            if ImDrawCmd_HeaderCompare(last_cmd, next_cmd) and last_cmd.UserCallback == nil and next_cmd.UserCallback == nil then
                -- Merge previous channel last draw command with current channel first draw command if matching.
                last_cmd.ElemCount = last_cmd.ElemCount + next_cmd.ElemCount
                idx_offset = idx_offset + next_cmd.ElemCount
                cmds:erase(1) -- FIXME-OPT: Improve for multiple merges.
            end
        end
        if cmds.Size > 0 then
            last_cmd = cmds.Data[cmds.Size]
        end
        new_cmd_buffer_count = new_cmd_buffer_count + cmds.Size
        new_idx_buffer_count = new_idx_buffer_count + ch._IdxBuffer.Size
        for cmd_n = 1, cmds.Size do
            cmds.Data[cmd_n].IdxOffset = idx_offset
            idx_offset = idx_offset + cmds.Data[cmd_n].ElemCount
        end
    end
    local cmd_write = draw_list.CmdBuffer.Size + 1
    local idx_write = draw_list.IdxBuffer.Size + 1
    draw_list.CmdBuffer:resize(draw_list.CmdBuffer.Size + new_cmd_buffer_count)
    draw_list.IdxBuffer:resize(draw_list.IdxBuffer.Size + new_idx_buffer_count)

    -- Write commands and indices in order (they are fairly small structures, we don't copy vertices only indices)
    local dst_cmds = draw_list.CmdBuffer.Data
    local dst_idx = draw_list.IdxBuffer.Data
    for i = 2, self._Count do
        local ch = channels[i]
        -- [Luau] skip empty buffers: their .Data may be nil (reading it goes through IM_VECTOR.__index)
        if ch._CmdBuffer.Size > 0 then
            local src_cmds = ch._CmdBuffer.Data
            for n = 1, ch._CmdBuffer.Size do
                dst_cmds[cmd_write] = src_cmds[n]
                src_cmds[n] = nil -- ownership moved to the draw list
                cmd_write = cmd_write + 1
            end
        end
        if ch._IdxBuffer.Size > 0 then
            local src_idx = ch._IdxBuffer.Data
            for n = 1, ch._IdxBuffer.Size do
                dst_idx[idx_write] = src_idx[n]
                idx_write = idx_write + 1
            end
        end
    end
    draw_list._IdxWritePtr = idx_write

    -- Ensure there's always a non-callback draw command trailing the command-buffer
    if draw_list.CmdBuffer.Size == 0 or draw_list.CmdBuffer.Data[draw_list.CmdBuffer.Size].UserCallback ~= nil then
        draw_list:AddDrawCmd()
    end

    -- If current command is used with different settings we need to add a new command
    local curr_cmd = draw_list.CmdBuffer.Data[draw_list.CmdBuffer.Size]
    if curr_cmd.ElemCount == 0 then
        ImDrawCmd_HeaderCopyRef(curr_cmd, draw_list._CmdHeader) -- Copy ClipRect, TexRef, VtxOffset
    elseif not ImDrawCmd_HeaderCompare(curr_cmd, draw_list._CmdHeader) then
        draw_list:AddDrawCmd()
    end

    self._Count = 1
end

--- @param draw_list ImDrawList
--- @param idx       int # 0-based channel index

function MT.ImDrawListSplitter:SetCurrentChannel(draw_list, idx)
    IM_ASSERT(idx >= 0 and idx < self._Count)
    if self._Current == idx then
        return
    end

    -- Overwrite ImVector (12/16 bytes), four times. This is merely a silly optimization instead of doing .swap()
    local channels = self._Channels.Data
    local cur = channels[self._Current + 1]
    cur._CmdBuffer = draw_list.CmdBuffer
    cur._IdxBuffer = draw_list.IdxBuffer
    self._Current = idx
    local ch = channels[idx + 1]
    local cmd_buffer = ch._CmdBuffer
    local idx_buffer = ch._IdxBuffer
    draw_list.CmdBuffer = cmd_buffer
    draw_list.IdxBuffer = idx_buffer
    draw_list._IdxWritePtr = idx_buffer.Size + 1

    -- If current command is used with different settings we need to add a new command
    -- [Luau] ImDrawCmd_HeaderCopyRef() / ImDrawCmd_HeaderCompare() inlined
    local cmd_count = cmd_buffer.Size
    if cmd_count == 0 then
        draw_list:AddDrawCmd()
        return
    end
    local curr_cmd = cmd_buffer.Data[cmd_count]
    local header = draw_list._CmdHeader
    local hcr, ccr = header.ClipRect, curr_cmd.ClipRect
    if curr_cmd.ElemCount == 0 then
        ccr.x = hcr.x; ccr.y = hcr.y; ccr.z = hcr.z; ccr.w = hcr.w -- Copy ClipRect, TexRef, VtxOffset
        curr_cmd.TexRef = header.TexRef
        curr_cmd.VtxOffset = header.VtxOffset
    elseif ccr.x ~= hcr.x or ccr.y ~= hcr.y or ccr.z ~= hcr.z or ccr.w ~= hcr.w
        or curr_cmd.TexRef._TexData ~= header.TexRef._TexData or curr_cmd.TexRef._TexID ~= header.TexRef._TexID
        or curr_cmd.VtxOffset ~= header.VtxOffset then
        draw_list:AddDrawCmd()
    end
end

--- @param count int
function MT.ImDrawList:ChannelsSplit(count) self._Splitter:Split(self, count) end
function MT.ImDrawList:ChannelsMerge() self._Splitter:Merge(self) end
--- @param n int # 0-based
function MT.ImDrawList:ChannelsSetCurrent(n) self._Splitter:SetCurrentChannel(self, n) end

-- - We intentionally avoid using ImVec2 and its math operators here to reduce cost to a minimum for debug/non-inlined builds.
-- - Filled shapes must always use clockwise winding order. The anti-aliasing fringe depends on it. Counter-clockwise shapes will have "inward" anti-aliasing.
--- @param points       ImVec2[]
--- @param points_count int
--- @param col          ImU32

function MT.ImDrawList:AddConvexPolyFilled(points, points_count, col)
    if points_count < 3 or bit32.band(col, IM_COL32_A_MASK) == 0 then
        return
    end

    local uv = self._Data.TexUvWhitePixel

    if bit32.band(self.Flags, ImDrawListFlags.AntiAliasedFill) ~= 0 then
        local AA_SIZE = self._FringeScale
        local col_trans = bit32.band(col, bit32.bnot(IM_COL32_A_MASK))
        local idx_count = (points_count - 2) * 3 + points_count * 6
        local vtx_count = points_count * 2
        self:PrimReserve(idx_count, vtx_count)

        local vtx_inner_idx = self._VtxCurrentIdx
        local vtx_outer_idx = self._VtxCurrentIdx + 1
        local idx_data = self.IdxBuffer.Data
        local idx_write_ptr = self._IdxWritePtr -- [Luau] write pointers kept in locals, stored back after the loops
        for i = 2, points_count - 1 do
            idx_data[idx_write_ptr + 0] = vtx_inner_idx; idx_data[idx_write_ptr + 1] = vtx_inner_idx + ((i - 1) * 2); idx_data[idx_write_ptr + 2] = vtx_inner_idx + (i * 2)
            idx_write_ptr = idx_write_ptr + 3
        end

        -- Compute normals
        local temp_buffer = self._Data.TempBuffer
        if points_count > temp_buffer.Capacity then temp_buffer:reserve_discard(points_count) end -- [Luau] skip the method lookup when no growth is needed
        local temp_normals = self._Data.TempBuffer.Data

        local i0 = points_count
        for i1 = 1, points_count do
            local p0 = points[i0]
            local p1 = points[i1]
            local dx = p1.x - p0.x
            local dy = p1.y - p0.y
            dx, dy = IM_NORMALIZE2F_OVER_ZERO(dx, dy)
            temp_normals[i0].x = dy
            temp_normals[i0].y = -dx

            i0 = i1
        end

        local vtx_data = self.VtxBuffer.Buf
        local vtx_write_ptr = self._VtxWritePtr
        local uv_x, uv_y = uv.x, uv.y
        i0 = points_count
        for i1 = 1, points_count do
            local n0 = temp_normals[i0]
            local n1 = temp_normals[i1]
            local dm_x = (n0.x + n1.x) * 0.5
            local dm_y = (n0.y + n1.y) * 0.5
            dm_x, dm_y = IM_FIXNORMAL2F(dm_x, dm_y)
            dm_x = dm_x * AA_SIZE * 0.5
            dm_y = dm_y * AA_SIZE * 0.5

            local p1 = points[i1]
            WV(vtx_data, vtx_write_ptr + 0, p1.x - dm_x, p1.y - dm_y, uv_x, uv_y, col)
            WV(vtx_data, vtx_write_ptr + 1, p1.x + dm_x, p1.y + dm_y, uv_x, uv_y, col_trans)
            vtx_write_ptr = vtx_write_ptr + 2

            idx_data[idx_write_ptr + 0] = vtx_inner_idx + ((i1 - 1) * 2); idx_data[idx_write_ptr + 1] = vtx_inner_idx + ((i0 - 1) * 2); idx_data[idx_write_ptr + 2] = vtx_outer_idx + ((i0 - 1) * 2)
            idx_data[idx_write_ptr + 3] = vtx_outer_idx + ((i0 - 1) * 2); idx_data[idx_write_ptr + 4] = vtx_outer_idx + ((i1 - 1) * 2); idx_data[idx_write_ptr + 5] = vtx_inner_idx + ((i1 - 1) * 2)
            idx_write_ptr = idx_write_ptr + 6

            i0 = i1
        end
        self._VtxWritePtr = vtx_write_ptr
        self._IdxWritePtr = idx_write_ptr
        self._VtxCurrentIdx = self._VtxCurrentIdx + vtx_count
    else
        local idx_count = (points_count - 2) * 3
        local vtx_count = points_count
        self:PrimReserve(idx_count, vtx_count)

        local idx_data = self.IdxBuffer.Data; local vtx_data = self.VtxBuffer.Buf
        for i = 1, vtx_count do
            local vtx_write_ptr = self._VtxWritePtr
            WVP(vtx_data, vtx_write_ptr + 0, points[i], uv, col)
            self._VtxWritePtr = vtx_write_ptr + 1
        end
        for i = 3, points_count do
            local idx_write_ptr = self._IdxWritePtr
            idx_data[idx_write_ptr + 0] = self._VtxCurrentIdx; idx_data[idx_write_ptr + 1] = self._VtxCurrentIdx + i - 2; idx_data[idx_write_ptr + 2] = self._VtxCurrentIdx + i - 1
            self._IdxWritePtr = idx_write_ptr + 3
        end

        self._VtxCurrentIdx = self._VtxCurrentIdx + vtx_count
    end
end

function MT.ImDrawList:PushTexture(tex_ref)
    self._TextureStack:push_back(tex_ref)
    self._CmdHeader.TexRef = tex_ref
    if (tex_ref._TexData ~= nil) then
        IM_ASSERT(tex_ref._TexData.WantDestroyNextFrame == false)
    end
    self:_OnChangedTexture()
end

function MT.ImDrawList:PopTexture()
    self._TextureStack:pop_back()
    self._CmdHeader.TexRef = (self._TextureStack.Size == 0) and ImTextureRef() or self._TextureStack.Data[self._TextureStack.Size]
    self:_OnChangedTexture()
end

-- This is used by ImGui.PushFont()/PopFont(). It works because we never use _TextureIdStack[] elsewhere than in PushTexture()/PopTexture().
function MT.ImDrawList:_SetTexture(tex_ref)
    if (self._CmdHeader.TexRef == tex_ref) then
        return
    end
    self._CmdHeader.TexRef = tex_ref
    self._TextureStack.Data[self._TextureStack.Size] = tex_ref
    self:_OnChangedTexture()
end

-- Reserve space for a number of vertices and indices.
-- You must finish filling your reserved data before calling PrimReserve() again, as it may reallocate or
-- submit the intermediate results. PrimUnreserve() can be used to release unused allocations.
-- [Luau] local function (also MT.ImDrawList.PrimReserve): hot callers in this file skip the method lookup

local function PrimReserve(self, idx_count, vtx_count)
    -- Large mesh support (when enabled)
    IM_ASSERT_PARANOID(idx_count >= 0 and vtx_count >= 0)

    if (self._VtxCurrentIdx + vtx_count >= bit32.lshift(1, 16)) and (bit32.band(self.Flags, ImDrawListFlags.AllowVtxOffset) ~= 0) then
        -- FIXME: In theory we should be testing that vtx_count <64k here.
        -- In practice, RenderText() relies on reserving ahead for a worst case scenario so it is currently useful for us
        -- to not make that check until we rework the text functions to handle clipping and large horizontal lines better.
        self._CmdHeader.VtxOffset = self.VtxBuffer.Size + 1
        self:_OnChangedVtxOffset()
    end

    local draw_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size]
    draw_cmd.ElemCount = draw_cmd.ElemCount + idx_count

    -- [Luau] inline resize() when no growth is needed (IdxBuffer:resize goes through IM_VECTOR.__index)
    local vtx_buffer = self.VtxBuffer
    local vtx_buffer_old_size = vtx_buffer.Size
    local vtx_new_size = vtx_buffer_old_size + vtx_count
    if vtx_new_size > vtx_buffer.Capacity then vtx_buffer:resize(vtx_new_size) else vtx_buffer.Size = vtx_new_size end
    self._VtxWritePtr = vtx_buffer_old_size + 1

    local idx_buffer = self.IdxBuffer
    local idx_buffer_old_size = idx_buffer.Size
    local idx_new_size = idx_buffer_old_size + idx_count
    if idx_new_size > idx_buffer.Capacity then idx_buffer:resize(idx_new_size) else idx_buffer.Size = idx_new_size end
    self._IdxWritePtr = idx_buffer_old_size + 1
end
MT.ImDrawList.PrimReserve = PrimReserve

-- Release the number of reserved vertices/indices from the end of the last reservation made with PrimReserve().
function MT.ImDrawList:PrimUnreserve(idx_count, vtx_count)
    IM_ASSERT_PARANOID(idx_count >= 0 and vtx_count >= 0)

    local draw_cmd = self.CmdBuffer.Data[self.CmdBuffer.Size]
    draw_cmd.ElemCount = draw_cmd.ElemCount - idx_count

    self.VtxBuffer:shrink(self.VtxBuffer.Size - vtx_count)
    self.IdxBuffer:shrink(self.IdxBuffer.Size - idx_count)

    self._VtxWritePtr = self.VtxBuffer.Size + 1
    self._IdxWritePtr = self.IdxBuffer.Size + 1
end

-- Fully unrolled with inline call to keep our debug builds decently fast.
--- @param a   ImVec2
--- @param c   ImVec2
--- @param col ImU32
-- [Luau] scalar PrimRect (a = ax,ay; c = cx,cy): no ImVec2 needed by callers, vertex writes inlined

local function PrimRectXY(self, ax, ay, cx, cy, col)
    local uv = self._Data.TexUvWhitePixel

    local idx = self._VtxCurrentIdx
    local idx_data = self.IdxBuffer.Data; local b = self.VtxBuffer.Buf

    local idx_write_ptr = self._IdxWritePtr
    idx_data[idx_write_ptr + 0] = idx
    idx_data[idx_write_ptr + 1] = idx + 1
    idx_data[idx_write_ptr + 2] = idx + 2

    idx_data[idx_write_ptr + 3] = idx
    idx_data[idx_write_ptr + 4] = idx + 2
    idx_data[idx_write_ptr + 5] = idx + 3

    local vtx_write_ptr = self._VtxWritePtr
    local u, v = uv.x, uv.y
    local o = (vtx_write_ptr - 1) * 36
    writef64(b, o, ax); writef64(b, o + 8, ay); writef64(b, o + 16, u); writef64(b, o + 24, v); writeu32(b, o + 32, col)
    writef64(b, o + 36, cx); writef64(b, o + 44, ay); writef64(b, o + 52, u); writef64(b, o + 60, v); writeu32(b, o + 68, col)
    writef64(b, o + 72, cx); writef64(b, o + 80, cy); writef64(b, o + 88, u); writef64(b, o + 96, v); writeu32(b, o + 104, col)
    writef64(b, o + 108, ax); writef64(b, o + 116, cy); writef64(b, o + 124, u); writef64(b, o + 132, v); writeu32(b, o + 140, col)

    self._VtxWritePtr = vtx_write_ptr + 4
    self._VtxCurrentIdx = idx + 4
    self._IdxWritePtr = idx_write_ptr + 6
end

function MT.ImDrawList:PrimRect(a, c, col)
    PrimRectXY(self, a.x, a.y, c.x, c.y, col)
end

--- @param a    ImVec2
--- @param c    ImVec2
--- @param uv_a ImVec2
--- @param uv_c ImVec2
--- @param col  any
function MT.ImDrawList:PrimRectUV(a, c, uv_a, uv_c, col)
    local idx = self._VtxCurrentIdx
    local idx_data = self.IdxBuffer.Data; local vtx_data = self.VtxBuffer.Buf

    local idx_write_ptr = self._IdxWritePtr
    idx_data[idx_write_ptr + 0] = idx
    idx_data[idx_write_ptr + 1] = idx + 1
    idx_data[idx_write_ptr + 2] = idx + 2

    idx_data[idx_write_ptr + 3] = idx
    idx_data[idx_write_ptr + 4] = idx + 2
    idx_data[idx_write_ptr + 5] = idx + 3

    local vtx_write_ptr = self._VtxWritePtr
    WV(vtx_data, vtx_write_ptr + 0, a.x, a.y, uv_a.x, uv_a.y, col)
    WV(vtx_data, vtx_write_ptr + 1, c.x, a.y, uv_c.x, uv_a.y, col)
    WV(vtx_data, vtx_write_ptr + 2, c.x, c.y, uv_c.x, uv_c.y, col)
    WV(vtx_data, vtx_write_ptr + 3, a.x, c.y, uv_a.x, uv_c.y, col)

    self._VtxWritePtr   = vtx_write_ptr + 4
    self._VtxCurrentIdx = idx + 4
    self._IdxWritePtr   = idx_write_ptr + 6
end

--- @param points       ImVec2[]
--- @param points_count int
--- @param col          ImU32
--- @param thickness    float
--- @param flags?       ImDrawFlags

function MT.ImDrawList:AddPolyline(points, points_count, col, thickness, flags)
    if flags == nil then flags = 0 end

    if points_count < 2 or bit32.band(col, IM_COL32_A_MASK) == 0 then
        return
    end

    local closed = bit32.band(flags, ImDrawFlags.Closed) ~= 0
    local opaque_uv = self._Data.TexUvWhitePixel
    local count = closed and points_count or points_count - 1 -- Number of line segments
    local thick_line = thickness > self._FringeScale
    -- If this assert triggers on legacy code:
    -- - 1.92.8 (2025/05): swapped two last parameters order: flags, thickness --> thickness, flags. This should normally be caught by compile-time type-checking.
    -- - 1.92.8 (2025/05): changed value of ImDrawList_Closed which was previously guaranteed to be == 1. Hardcoded use of 1 or true should be replaced.
    -- Read more details near AddRect() + see "API BREAKING CHANGES" section for 1.82, 1.90 and 1.92.8.
    IM_ASSERT_USER_ERROR_RET(bit32.band(flags, ImDrawFlags.InvalidMask_) == 0, "Incorrect parameter. Did you swap 'thickness' and 'flags'?")

    if bit32.band(self.Flags, ImDrawListFlags.AntiAliasedLines) ~= 0 then
        -- Anti-aliased stroke
        local AA_SIZE = self._FringeScale
        local col_trans = bit32.band(col, bit32.bnot(IM_COL32_A_MASK))

        -- Thicknesses <1.0 should behave like thickness 1.0
        thickness = ImMax(thickness, 1.0)
        local integer_thickness = ImFloor(thickness)
        local fractional_thickness = thickness - integer_thickness

        -- Do we want to draw this line using a texture?
        local use_texture = bit32.band(self.Flags, ImDrawListFlags.AntiAliasedLinesUseTex) ~= 0 and integer_thickness < IM_DRAWLIST_TEX_LINES_WIDTH_MAX and fractional_thickness <= 0.00001 and AA_SIZE == 1.0

        IM_ASSERT_PARANOID((not use_texture) or bit32.band(self._Data.Font.OwnerAtlas.Flags, ImFontAtlasFlags.NoBakedLines) == 0)

        local idx_count = use_texture and (count * 6) or (thick_line and count * 18 or count * 12)
        local vtx_count = use_texture and (points_count * 2) or (thick_line and points_count * 4 or points_count * 3)
        PrimReserve(self, idx_count, vtx_count)

        -- Temporary buffer
        local temp_buffer_size = points_count * ((use_texture or not thick_line) and 3 or 5)
        local temp_buffer = self._Data.TempBuffer
        if temp_buffer_size > temp_buffer.Capacity then temp_buffer:reserve_discard(temp_buffer_size) end -- [Luau] skip the method lookup when no growth is needed
        local temp_normals = self._Data.TempBuffer.Data
        local temp_points = self._Data.TempBuffer.Data; local temp_points_start = points_count + 1

        -- Calculate normals for each line segment
        for i1 = 1, count do
            local i2 = (i1 == points_count) and 1 or i1 + 1
            local p1 = points[i1]
            local p2 = points[i2]
            local dx = p2.x - p1.x
            local dy = p2.y - p1.y
            dx, dy = IM_NORMALIZE2F_OVER_ZERO(dx, dy)
            temp_normals[i1].x = dy
            temp_normals[i1].y = -dx
        end
        if not closed then
            ImVec2_Copy(temp_normals[points_count], temp_normals[points_count - 1])
        end

        -- If we are drawing a one-pixel-wide line without a texture, or a textured line of any width
        if use_texture or not thick_line then
            -- [PATH 1] Texture-based lines (thick or non-thick)
            -- [PATH 2] Non texture-based lines (non-thick)
            local half_draw_size = use_texture and (thickness * 0.5 + 1) or AA_SIZE

            -- If line is not closed, the first and last points need to be generated differently
            if not closed then
                ImVec2_CopyV(temp_points[temp_points_start + 0], ImVec2_AddVA(points[1], ImVec2_MulVX(temp_normals[1], half_draw_size)))
                ImVec2_CopyV(temp_points[temp_points_start + 1], ImVec2_SubVA(points[1], ImVec2_MulVX(temp_normals[1], half_draw_size)))
                ImVec2_CopyV(temp_points[temp_points_start + (points_count - 1) * 2 + 0], ImVec2_AddVA(points[points_count], ImVec2_MulVX(temp_normals[points_count], half_draw_size)))
                ImVec2_CopyV(temp_points[temp_points_start + (points_count - 1) * 2 + 1], ImVec2_SubVA(points[points_count], ImVec2_MulVX(temp_normals[points_count], half_draw_size)))
            end

            -- Generate indices and vertices
            local idx1 = self._VtxCurrentIdx
            local idx_data = self.IdxBuffer.Data; local vtx_data = self.VtxBuffer.Buf
            local idx_write_ptr = self._IdxWritePtr -- [Luau] write pointers kept in locals, stored back after the loops
            for i1 = 1, count do
                local i2 = (i1 == points_count) and 1 or i1 + 1
                local idx2 = (i1 == points_count) and self._VtxCurrentIdx or (idx1 + (use_texture and 2 or 3))

                -- Average normals
                local dm_x = (temp_normals[i1].x + temp_normals[i2].x) * 0.5
                local dm_y = (temp_normals[i1].y + temp_normals[i2].y) * 0.5
                dm_x, dm_y = IM_FIXNORMAL2F(dm_x, dm_y)
                dm_x = dm_x * half_draw_size
                dm_y = dm_y * half_draw_size

                -- Add temporary vertices for the outer edges
                local out_off = (i2 - 1) * 2
                temp_points[temp_points_start + out_off + 0].x = points[i2].x + dm_x
                temp_points[temp_points_start + out_off + 0].y = points[i2].y + dm_y
                temp_points[temp_points_start + out_off + 1].x = points[i2].x - dm_x
                temp_points[temp_points_start + out_off + 1].y = points[i2].y - dm_y

                if use_texture then
                    -- Add indices for two triangles
                    idx_data[idx_write_ptr + 0] = idx2 + 0; idx_data[idx_write_ptr + 1] = idx1 + 0; idx_data[idx_write_ptr + 2] = idx1 + 1
                    idx_data[idx_write_ptr + 3] = idx2 + 1; idx_data[idx_write_ptr + 4] = idx1 + 1; idx_data[idx_write_ptr + 5] = idx2 + 0
                    idx_write_ptr = idx_write_ptr + 6
                else
                    -- Add indices for four triangles
                    idx_data[idx_write_ptr + 0] = idx2 + 0; idx_data[idx_write_ptr + 1] = idx1 + 0; idx_data[idx_write_ptr + 2] = idx1 + 2
                    idx_data[idx_write_ptr + 3] = idx1 + 2; idx_data[idx_write_ptr + 4] = idx2 + 2; idx_data[idx_write_ptr + 5] = idx2 + 0
                    idx_data[idx_write_ptr + 6] = idx2 + 1; idx_data[idx_write_ptr + 7] = idx1 + 1; idx_data[idx_write_ptr + 8] = idx1 + 0
                    idx_data[idx_write_ptr + 9] = idx1 + 0; idx_data[idx_write_ptr + 10] = idx2 + 0; idx_data[idx_write_ptr + 11] = idx2 + 1
                    idx_write_ptr = idx_write_ptr + 12
                end

                idx1 = idx2
            end
            self._IdxWritePtr = idx_write_ptr

            -- Add vertices
            local vtx_write_ptr = self._VtxWritePtr
            if use_texture then
                -- Texture-based: need to implement TexUvLines lookup
                local tex_uvs = self._Data.TexUvLines[integer_thickness]
                local tex_uv0 = ImVec2(tex_uvs.x, tex_uvs.y)
                local tex_uv1 = ImVec2(tex_uvs.z, tex_uvs.w)
                for i = 0, points_count - 1 do
                    WVP(vtx_data, vtx_write_ptr + 0, temp_points[temp_points_start + i * 2 + 0], tex_uv0, col)
                    WVP(vtx_data, vtx_write_ptr + 1, temp_points[temp_points_start + i * 2 + 1], tex_uv1, col)
                    vtx_write_ptr = vtx_write_ptr + 2
                end
            else
                -- If we're not using a texture, we need the center vertex as well
                for i = 0, points_count - 1 do
                    WVP(vtx_data, vtx_write_ptr + 0, points[i + 1], opaque_uv, col)
                    WVP(vtx_data, vtx_write_ptr + 1, temp_points[temp_points_start + i * 2 + 0], opaque_uv, col_trans)
                    WVP(vtx_data, vtx_write_ptr + 2, temp_points[temp_points_start + i * 2 + 1], opaque_uv, col_trans)
                    vtx_write_ptr = vtx_write_ptr + 3
                end
            end
            self._VtxWritePtr = vtx_write_ptr
        else
            -- [PATH 3] Non texture-based lines (thick)
            local half_inner_thickness = (thickness - AA_SIZE) * 0.5

            -- If line is not closed, handle first and last points
            if not closed then
                local points_last = points_count - 1
                ImVec2_CopyV(temp_points[temp_points_start + 0], ImVec2_AddVA(points[1], ImVec2_MulVX(temp_normals[1], (half_inner_thickness + AA_SIZE))))
                ImVec2_CopyV(temp_points[temp_points_start + 1], ImVec2_AddVA(points[1], ImVec2_MulVX(temp_normals[1], half_inner_thickness)))
                ImVec2_CopyV(temp_points[temp_points_start + 2], ImVec2_SubVA(points[1], ImVec2_MulVX(temp_normals[1], half_inner_thickness)))
                ImVec2_CopyV(temp_points[temp_points_start + 3], ImVec2_SubVA(points[1], ImVec2_MulVX(temp_normals[1], (half_inner_thickness + AA_SIZE))))
                ImVec2_CopyV(temp_points[temp_points_start + points_last * 4 + 0], ImVec2_AddVA(points[points_count], ImVec2_MulVX(temp_normals[points_last + 1], (half_inner_thickness + AA_SIZE))))
                ImVec2_CopyV(temp_points[temp_points_start + points_last * 4 + 1], ImVec2_AddVA(points[points_count], ImVec2_MulVX(temp_normals[points_last + 1], half_inner_thickness)))
                ImVec2_CopyV(temp_points[temp_points_start + points_last * 4 + 2], ImVec2_SubVA(points[points_count], ImVec2_MulVX(temp_normals[points_last + 1], half_inner_thickness)))
                ImVec2_CopyV(temp_points[temp_points_start + points_last * 4 + 3], ImVec2_SubVA(points[points_count], ImVec2_MulVX(temp_normals[points_last + 1], (half_inner_thickness + AA_SIZE))))
            end

            -- Generate indices and vertices
            local idx1 = self._VtxCurrentIdx
            local idx_data = self.IdxBuffer.Data; local vtx_data = self.VtxBuffer.Buf
            local idx_write_ptr = self._IdxWritePtr -- [Luau] write pointers kept in locals, stored back after the loops
            for i1 = 1, count do
                local i2 = (i1 == points_count) and 1 or i1 + 1
                local idx2 = (i1 == points_count) and self._VtxCurrentIdx or (idx1 + 4)

                -- Average normals
                local dm_x = (temp_normals[i1].x + temp_normals[i2].x) * 0.5
                local dm_y = (temp_normals[i1].y + temp_normals[i2].y) * 0.5
                dm_x, dm_y = IM_FIXNORMAL2F(dm_x, dm_y)
                local dm_out_x = dm_x * (half_inner_thickness + AA_SIZE)
                local dm_out_y = dm_y * (half_inner_thickness + AA_SIZE)
                local dm_in_x = dm_x * half_inner_thickness
                local dm_in_y = dm_y * half_inner_thickness

                -- Add temporary vertices
                local out_off = (i2 - 1) * 4
                temp_points[temp_points_start + out_off + 0].x = points[i2].x + dm_out_x
                temp_points[temp_points_start + out_off + 0].y = points[i2].y + dm_out_y
                temp_points[temp_points_start + out_off + 1].x = points[i2].x + dm_in_x
                temp_points[temp_points_start + out_off + 1].y = points[i2].y + dm_in_y
                temp_points[temp_points_start + out_off + 2].x = points[i2].x - dm_in_x
                temp_points[temp_points_start + out_off + 2].y = points[i2].y - dm_in_y
                temp_points[temp_points_start + out_off + 3].x = points[i2].x - dm_out_x
                temp_points[temp_points_start + out_off + 3].y = points[i2].y - dm_out_y

                -- Add indices
                idx_data[idx_write_ptr + 0] = idx2 + 1; idx_data[idx_write_ptr + 1] = idx1 + 1; idx_data[idx_write_ptr + 2] = idx1 + 2
                idx_data[idx_write_ptr + 3] = idx1 + 2; idx_data[idx_write_ptr + 4] = idx2 + 2; idx_data[idx_write_ptr + 5] = idx2 + 1
                idx_data[idx_write_ptr + 6] = idx2 + 1; idx_data[idx_write_ptr + 7] = idx1 + 1; idx_data[idx_write_ptr + 8] = idx1 + 0
                idx_data[idx_write_ptr + 9] = idx1 + 0; idx_data[idx_write_ptr + 10] = idx2 + 0; idx_data[idx_write_ptr + 11] = idx2 + 1
                idx_data[idx_write_ptr + 12] = idx2 + 2; idx_data[idx_write_ptr + 13] = idx1 + 2; idx_data[idx_write_ptr + 14] = idx1 + 3
                idx_data[idx_write_ptr + 15] = idx1 + 3; idx_data[idx_write_ptr + 16] = idx2 + 3; idx_data[idx_write_ptr + 17] = idx2 + 2
                idx_write_ptr = idx_write_ptr + 18

                idx1 = idx2
            end
            self._IdxWritePtr = idx_write_ptr

            -- Add vertices
            local vtx_write_ptr = self._VtxWritePtr
            for i = 0, points_count - 1 do
                WVP(vtx_data, vtx_write_ptr + 0, temp_points[temp_points_start + i * 4 + 0], opaque_uv, col_trans)
                WVP(vtx_data, vtx_write_ptr + 1, temp_points[temp_points_start + i * 4 + 1], opaque_uv, col)
                WVP(vtx_data, vtx_write_ptr + 2, temp_points[temp_points_start + i * 4 + 2], opaque_uv, col)
                WVP(vtx_data, vtx_write_ptr + 3, temp_points[temp_points_start + i * 4 + 3], opaque_uv, col_trans)
                vtx_write_ptr = vtx_write_ptr + 4
            end
            self._VtxWritePtr = vtx_write_ptr
        end
        self._VtxCurrentIdx = self._VtxCurrentIdx + vtx_count
    else
        -- [PATH 4] Non texture-based, Non anti-aliased lines
        local idx_count = count * 6
        local vtx_count = count * 4
        PrimReserve(self, idx_count, vtx_count)

        local idx_data = self.IdxBuffer.Data; local vtx_data = self.VtxBuffer.Buf
        for i1 = 1, count do
            local i2 = (i1 == points_count) and 1 or i1 + 1
            local p1 = points[i1]
            local p2 = points[i2]

            local dx = p2.x - p1.x
            local dy = p2.y - p1.y
            dx, dy = IM_NORMALIZE2F_OVER_ZERO(dx, dy)
            dx = dx * (thickness * 0.5)
            dy = dy * (thickness * 0.5)

            local vtx_write_ptr = self._VtxWritePtr
            WV(vtx_data, vtx_write_ptr + 0, p1.x + dy, p1.y - dx, opaque_uv.x, opaque_uv.y, col)
            WV(vtx_data, vtx_write_ptr + 1, p2.x + dy, p2.y - dx, opaque_uv.x, opaque_uv.y, col)
            WV(vtx_data, vtx_write_ptr + 2, p2.x - dy, p2.y + dx, opaque_uv.x, opaque_uv.y, col)
            WV(vtx_data, vtx_write_ptr + 3, p1.x - dy, p1.y + dx, opaque_uv.x, opaque_uv.y, col)
            self._VtxWritePtr = vtx_write_ptr + 4

            local idx_write_ptr = self._IdxWritePtr
            idx_data[idx_write_ptr + 0] = self._VtxCurrentIdx + 0; idx_data[idx_write_ptr + 1] = self._VtxCurrentIdx + 1; idx_data[idx_write_ptr + 2] = self._VtxCurrentIdx + 2
            idx_data[idx_write_ptr + 3] = self._VtxCurrentIdx + 0; idx_data[idx_write_ptr + 4] = self._VtxCurrentIdx + 2; idx_data[idx_write_ptr + 5] = self._VtxCurrentIdx + 3
            self._IdxWritePtr = idx_write_ptr + 6
            self._VtxCurrentIdx = self._VtxCurrentIdx + 4
        end
    end
end

-- [Luau] scalar PathLineTo(): no temporary ImVec2 (the path slot is written in place)
local function PathLineToXY(self, x, y)
    local path = self._Path
    local n = path.Size + 1
    if n > path.Capacity then path:push_back(ImVec2(x, y)) return end
    local dest = path.Data[n]
    dest.x = x; dest.y = y
    path.Size = n
end

local _PathArcToFastExXY -- [Luau] forward declaration, defined below with _PathArcToFastEx()

-- [Luau] scalar PathRect (a = ax,ay; b = bx,by); PathRect() below wraps it
local function PathRectXY(self, ax, ay, bx, by, rounding, flags)
    if not rounding then rounding = 0.0 end
    if not flags    then flags    = 0   end

    if rounding >= 0.5 then
        IM_ASSERT(bit32.band(flags, 0x0F) == 0, "Misuse of legacy hardcoded ImDrawCornerFlags values!")
        if bit32.band(flags, ImDrawFlags.RoundCornersMask_) == 0 then
            flags = bit32.bor(flags, ImDrawFlags.RoundCornersAll)
        end
        rounding = ImMin(rounding, ImAbs(bx - ax) * (((bit32.band(flags, ImDrawFlags.RoundCornersTop) == ImDrawFlags.RoundCornersTop) or (bit32.band(flags, ImDrawFlags.RoundCornersBottom) == ImDrawFlags.RoundCornersBottom)) and 0.5 or 1.0) - 1.0)
        rounding = ImMin(rounding, ImAbs(by - ay) * (((bit32.band(flags, ImDrawFlags.RoundCornersLeft) == ImDrawFlags.RoundCornersLeft) or (bit32.band(flags, ImDrawFlags.RoundCornersRight) == ImDrawFlags.RoundCornersRight)) and 0.5 or 1.0) - 1.0)
    end
    if rounding < 0.5 or (bit32.band(flags, ImDrawFlags.RoundCornersMask_) == ImDrawFlags.RoundCornersNone) then
        PathLineToXY(self, ax, ay)
        PathLineToXY(self, bx, ay)
        PathLineToXY(self, bx, by)
        PathLineToXY(self, ax, by)
    else
        local rounding_tl = (bit32.band(flags, ImDrawFlags.RoundCornersTopLeft) ~= 0) and rounding or 0.0
        local rounding_tr = (bit32.band(flags, ImDrawFlags.RoundCornersTopRight) ~= 0) and rounding or 0.0
        local rounding_br = (bit32.band(flags, ImDrawFlags.RoundCornersBottomRight) ~= 0) and rounding or 0.0
        local rounding_bl = (bit32.band(flags, ImDrawFlags.RoundCornersBottomLeft) ~= 0) and rounding or 0.0
        -- [Luau] inline PathArcToFast() (radius < 0.5 handled by _PathArcToFastExXY())
        _PathArcToFastExXY(self, ax + rounding_tl, ay + rounding_tl, rounding_tl, 6 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, 9 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, 0)
        _PathArcToFastExXY(self, bx - rounding_tr, ay + rounding_tr, rounding_tr, 9 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, 12 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, 0)
        _PathArcToFastExXY(self, bx - rounding_br, by - rounding_br, rounding_br, 0 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, 3 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, 0)
        _PathArcToFastExXY(self, ax + rounding_bl, by - rounding_bl, rounding_bl, 3 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, 6 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, 0)
    end
end

function MT.ImDrawList:PathRect(a, b, rounding, flags)
    PathRectXY(self, a.x, a.y, b.x, b.y, rounding, flags)
end


function MT.ImDrawList:AddRectFilled(p_min, p_max, col, rounding, flags)
    if not rounding then rounding = 0.0 end
    if not flags    then flags    = 0   end

    if bit32.band(col, IM_COL32_A_MASK) == 0 then return end

    if rounding < 0.5 or (bit32.band(flags, ImDrawFlags.RoundCornersMask_) == ImDrawFlags.RoundCornersNone) then
        PrimReserve(self, 6, 4) -- [Luau] local calls
        PrimRectXY(self, p_min.x, p_min.y, p_max.x, p_max.y, col)
    else
        PathRectXY(self, p_min.x, p_min.y, p_max.x, p_max.y, rounding, flags)
        self:PathFillConvex(col)
    end
end

-- p_min = upper-left, p_max = lower-right
-- Note: this does not support anti-aliasing when provided non-integer vertices.
--- @param p_min         ImVec2
--- @param p_max         ImVec2
--- @param col_upr_left  ImU32
--- @param col_upr_right ImU32
--- @param col_bot_right ImU32
--- @param col_bot_left  ImU32
function MT.ImDrawList:AddRectFilledMultiColor(p_min, p_max, col_upr_left, col_upr_right, col_bot_right, col_bot_left)
    if bit32.band(bit32.bor(col_upr_left, col_upr_right, col_bot_right, col_bot_left), IM_COL32_A_MASK) == 0 then
        return
    end

    local uv = self._Data.TexUvWhitePixel
    PrimReserve(self, 6, 4)
    -- [Luau] inline PrimWriteIdx()/PrimWriteVtx(): direct writes, no temporary ImVec2
    local idx, idx_data, idx_write_ptr = self._VtxCurrentIdx, self.IdxBuffer.Data, self._IdxWritePtr
    idx_data[idx_write_ptr] = idx; idx_data[idx_write_ptr + 1] = idx + 1; idx_data[idx_write_ptr + 2] = idx + 2
    idx_data[idx_write_ptr + 3] = idx; idx_data[idx_write_ptr + 4] = idx + 2; idx_data[idx_write_ptr + 5] = idx + 3
    self._IdxWritePtr = idx_write_ptr + 6
    local vtx_data, vtx_write_ptr = self.VtxBuffer.Buf, self._VtxWritePtr
    WV(vtx_data, vtx_write_ptr + 0, p_min.x, p_min.y, uv.x, uv.y, col_upr_left)
    WV(vtx_data, vtx_write_ptr + 1, p_max.x, p_min.y, uv.x, uv.y, col_upr_right)
    WV(vtx_data, vtx_write_ptr + 2, p_max.x, p_max.y, uv.x, uv.y, col_bot_right)
    WV(vtx_data, vtx_write_ptr + 3, p_min.x, p_max.y, uv.x, uv.y, col_bot_left)
    self._VtxWritePtr = vtx_write_ptr + 4
    self._VtxCurrentIdx = idx + 4
end

-- p_min = upper-left, p_max = lower-right
--- @param p_min      ImVec2
--- @param p_max      ImVec2
--- @param col        ImU32
--- @param rounding   float
--- @param thickness? float
--- @param flags?     ImDrawFlags

function MT.ImDrawList:AddRect(p_min, p_max, col, rounding, thickness, flags)
    if thickness == nil then thickness = 1.0 end
    if flags     == nil then flags     = 0   end

    -- If this assert triggers on legacy code:
    -- - 1.92.8 (2025/05): swapped two last parameters order: flags, thickness --> thickness, flags. This should normally be caught by compile-time type-checking.
    -- - 1.92.8 (2025/05): changed value of ImDrawList_Closed which was previously guaranteed to be == 1. Hardcoded use of 1 or true should be replaced.
    -- - 1.82.0 (2021/03): changed ImDrawCornerFlags to ImDrawFlags_RoundXXX values.
    --   If you used hard-coded 1 to 15 or ~0 in flags to configure corner rounding use the new flags!
    --   - Hard coded support for ~0 == ImDrawFlags_RoundAll.
    --   - Hard coded support for values 0x01 to 0x0F (matching 15 out of 16 old flags combinations) --> see FixRectCornerFlags() in <1.90 code.
    --   - Hard coded 0x00 with 'float rounding > 0.0f' --> replace with ImDrawFlags_RoundNone or use 'float rounding = 0.0f'.
    --   See "API BREAKING CHANGES" section for 1.82, 1.90 and 1.92.8.
    IM_ASSERT_USER_ERROR_RET(bit32.band(flags, ImDrawFlags.InvalidMask_) == 0, "Incorrect parameter. Did you swap 'thickness' and 'flags'?") -- Or misuse of legacy hard-coded ImDrawCornerFlags values

    if bit32.band(col, IM_COL32_A_MASK) == 0 then
        return
    end
    -- [Luau] square corners + whole-pixel thickness: 4 filled rects instead of a stroked path (same pixels, far cheaper here)
    if (rounding == nil or rounding < 0.5 or bit32.band(flags, ImDrawFlags.RoundCornersMask_) == ImDrawFlags.RoundCornersNone)
        and thickness >= 1.0 and thickness % 1 == 0 and p_max.x - p_min.x > 2 * thickness and p_max.y - p_min.y > 2 * thickness then
        local x0, y0, x1, y1, t = p_min.x, p_min.y, p_max.x, p_max.y, thickness
        PrimReserve(self, 24, 16)
        PrimRectXY(self, x0, y0, x1, y0 + t, col)
        PrimRectXY(self, x0, y1 - t, x1, y1, col)
        PrimRectXY(self, x0, y0 + t, x0 + t, y1 - t, col)
        PrimRectXY(self, x1 - t, y0 + t, x1, y1 - t, col)
        return
    end
    if bit32.band(self.Flags, ImDrawListFlags.AntiAliasedLines) ~= 0 then
        PathRectXY(self, p_min.x + 0.50, p_min.y + 0.50, p_max.x - 0.50, p_max.y - 0.50, rounding, flags) -- [Luau] scalar math, no temporary ImVec2
    else
        PathRectXY(self, p_min.x + 0.50, p_min.y + 0.50, p_max.x - 0.49, p_max.y - 0.49, rounding, flags) -- Better looking lower-right corner and rounded non-AA shapes.
    end

    self:PathStroke(col, thickness, ImDrawFlags.Closed)
end

function MT.ImDrawList:AddLine(p1, p2, col, thickness)
    if bit32.band(col, IM_COL32_A_MASK) == 0 then return end

    PathLineToXY(self, p1.x + 0.5, p1.y + 0.5) -- [Luau] scalar math, no temporary ImVec2
    PathLineToXY(self, p2.x + 0.5, p2.y + 0.5)
    self:PathStroke(col, thickness)
end

--- @param min_x      float
--- @param max_x      float
--- @param y          float
--- @param col        ImU32
--- @param thickness? float
function MT.ImDrawList:AddLineH(min_x, max_x, y, col, thickness)
    if thickness == nil then thickness = 1.0 end

    if bit32.band(col, IM_COL32_A_MASK) == 0 then
        return
    end
    PathLineToXY(self, min_x + 0.5, y + 0.5)
    PathLineToXY(self, max_x + 0.5, y + 0.5)
    self:PathStroke(col, thickness)
end

--- @param x          float
--- @param min_y      float
--- @param max_y      float
--- @param col        ImU32
--- @param thickness? float
function MT.ImDrawList:AddLineV(x, min_y, max_y, col, thickness)
    if thickness == nil then thickness = 1.0 end

    if bit32.band(col, IM_COL32_A_MASK) == 0 then
        return
    end
    PathLineToXY(self, x + 0.5, min_y + 0.5)
    PathLineToXY(self, x + 0.5, max_y + 0.5)
    self:PathStroke(col, thickness)
end

function MT.ImDrawList:AddTriangle(p1, p2, p3, col, thickness)
    if bit32.band(col, IM_COL32_A_MASK) == 0 then
        return
    end

    self:PathLineTo(p1)
    self:PathLineTo(p2)
    self:PathLineTo(p3)
    self:PathStroke(col, thickness, ImDrawFlags.Closed)
end

function MT.ImDrawList:AddQuad(p1, p2, p3, p4, col, thickness)
    if thickness == nil then thickness = 1.0 end
    if bit32.band(col, IM_COL32_A_MASK) == 0 then return end

    self:PathLineTo(p1)
    self:PathLineTo(p2)
    self:PathLineTo(p3)
    self:PathLineTo(p4)
    self:PathStroke(col, thickness, ImDrawFlags.Closed)
end

function MT.ImDrawList:AddQuadFilled(p1, p2, p3, p4, col)
    if bit32.band(col, IM_COL32_A_MASK) == 0 then return end

    self:PathLineTo(p1)
    self:PathLineTo(p2)
    self:PathLineTo(p3)
    self:PathLineTo(p4)
    self:PathFillConvex(col)
end

function MT.ImDrawList:AddTriangleFilled(p1, p2, p3, col)
    if bit32.band(col, IM_COL32_A_MASK) == 0 then return end

    self:PathLineTo(p1)
    self:PathLineTo(p2)
    self:PathLineTo(p3)
    self:PathFillConvex(col)
end

--- @param center       ImVec2
--- @param radius       float
--- @param col          ImU32
--- @param num_segments int
--- @param thickness    float
function MT.ImDrawList:AddCircle(center, radius, col, num_segments, thickness)
    if num_segments == nil then num_segments = 0   end
    if thickness    == nil then thickness    = 1.0 end

    if bit32.band(col, IM_COL32_A_MASK) == 0 or radius < 0.5 then
        return
    end

    if num_segments <= 0 then
        -- Use arc with automatic segment count
        _PathArcToFastExXY(self, center.x, center.y, radius - 0.5, 0, IM_DRAWLIST_ARCFAST_SAMPLE_MAX, 0)
        self._Path.Size = self._Path.Size - 1
    else
        -- Explicit segment count (still clamp to avoid drawing insanely tessellated shapes)
        num_segments = ImClamp(num_segments, 3, IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX)

        -- Because we are filling a closed shape we remove 1 from the count of segments/points
        local a_max = (IM_PI * 2.0) * (num_segments - 1) / num_segments
        self:PathArcTo(center, radius - 0.5, 0.0, a_max, num_segments - 1)
    end

    self:PathStroke(col, thickness, ImDrawFlags.Closed)
end

--- @param center       ImVec2
--- @param radius       float
--- @param col          ImU32
--- @param num_segments int
function MT.ImDrawList:AddCircleFilled(center, radius, col, num_segments)
    if num_segments == nil then num_segments = 0 end

    if bit32.band(col, IM_COL32_A_MASK) == 0 or radius < 0.5 then
        return
    end

    if num_segments <= 0 then
        -- Use arc with automatic segment count
        _PathArcToFastExXY(self, center.x, center.y, radius, 0, IM_DRAWLIST_ARCFAST_SAMPLE_MAX, 0)
        self._Path.Size = self._Path.Size - 1
    else
        -- Explicit segment count (still clamp to avoid drawing insanely tessellated shapes)
        num_segments = ImClamp(num_segments, 3, IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX)

        -- Because we are filling a closed shape we remove 1 from the count of segments/points
        local a_max = (IM_PI * 2.0) * (num_segments - 1) / num_segments
        self:PathArcTo(center, radius, 0.0, a_max, num_segments - 1)
    end

    self:PathFillConvex(col)
end

--- @param font                ImFont
--- @param font_size           float
--- @param pos                 ImVec2
--- @param col                 ImU32
--- @param text                string
--- @param text_begin?         int    # Defaults to 1
--- @param text_end            int
--- @param wrap_width          float
--- @param cpu_fine_clip_rect? ImVec4
local AddText_clip_rect = ImVec4()


function MT.ImDrawList:AddText(font, font_size, pos, col, text, text_begin, text_end, wrap_width, cpu_fine_clip_rect)
    -- Overload: AddText(pos, col, text, text_end?)
    if type(font) == "table" and type(font[1]) == "number" then
        font, font_size, pos, col, text, text_begin, text_end, wrap_width, cpu_fine_clip_rect = nil, 0.0, font, font_size, pos, 1, col, 0.0, nil
        if text_end == nil then text_end = #text + 1 end
    end
    if text_begin == nil then text_begin = 1 end

    if bit32.band(col, IM_COL32_A_MASK) == 0 then return end

    -- Accept null ranges
    if text_begin == text_end then
        return
    end
    -- No need to strlen() here: font:RenderText() will do it and may early out.

    -- Pull default font/size from the shared ImDrawListSharedData instance
    if font == nil then
        font = self._Data.Font
    end
    if font_size == 0.0 then
        font_size = self._Data.FontSize
    end

    local clip_rect = AddText_clip_rect -- Don't modify the clip rect! -- [Luau] scratch: ImFont:RenderText() only reads it
    local src = self._CmdHeader.ClipRect
    clip_rect.x = src.x; clip_rect.y = src.y; clip_rect.z = src.z; clip_rect.w = src.w
    if (cpu_fine_clip_rect) then
        clip_rect.x = math.max(clip_rect.x, cpu_fine_clip_rect.x)
        clip_rect.y = math.max(clip_rect.y, cpu_fine_clip_rect.y)
        clip_rect.z = math.min(clip_rect.z, cpu_fine_clip_rect.z)
        clip_rect.w = math.min(clip_rect.w, cpu_fine_clip_rect.w)
    end

    font:RenderText(self, font_size, pos, col, clip_rect, text, text_begin, text_end, wrap_width, (cpu_fine_clip_rect ~= nil) and ImDrawTextFlags.CpuFineClip or ImDrawTextFlags.None)
end

--- @param tex_ref ImTextureRef
--- @param p_min   ImVec2
--- @param p_max   ImVec2
--- @param uv_min? ImVec2
--- @param uv_max? ImVec2
--- @param col?    ImU32
function MT.ImDrawList:AddImage(tex_ref, p_min, p_max, uv_min, uv_max, col)
    if uv_min == nil then uv_min = ImVec2(0, 0)   end
    if uv_max == nil then uv_max = ImVec2(1, 1)   end
    if col    == nil then col    = IM_COL32_WHITE end

    if bit32.band(col, IM_COL32_A_MASK) == 0 then
        return
    end

    local push_texture_id = tex_ref ~= self._CmdHeader.TexRef
    if push_texture_id then
        self:PushTexture(tex_ref)
    end

    self:PrimReserve(6, 4)
    self:PrimRectUV(p_min, p_max, uv_min, uv_max, col)

    if push_texture_id then
        self:PopTexture()
    end
end

--- @param tex_ref  ImTextureRef
--- @param p_min    ImVec2
--- @param p_max    ImVec2
--- @param uv_min   ImVec2
--- @param uv_max   ImVec2
--- @param col      ImU32
--- @param rounding float
--- @param flags    ImDrawFlags
function MT.ImDrawList:AddImageRounded(tex_ref, p_min, p_max, uv_min, uv_max, col, rounding, flags)
    if bit32.band(col, IM_COL32_A_MASK) == 0 then
        return
    end

    IM_ASSERT(bit32.band(flags, 0x0F) == 0, "Misuse of legacy hardcoded ImDrawCornerFlags values!") -- If this assert triggers on legacy code: see comments in ImDrawList:PathRect().
    if bit32.band(flags, ImDrawFlags.RoundCornersMask_) == 0 then
        flags = bit32.bor(flags, ImDrawFlags.RoundCornersAll)
    end

    if rounding < 0.5 or bit32.band(flags, ImDrawFlags.RoundCornersMask_) == ImDrawFlags.RoundCornersNone then
        self:AddImage(tex_ref, p_min, p_max, uv_min, uv_max, col)
        return
    end

    local push_texture_id = (tex_ref ~= self._CmdHeader.TexRef)
    if push_texture_id then
        self:PushTexture(tex_ref)
    end

    local vert_start_idx = self.VtxBuffer.Size + 1
    self:PathRect(p_min, p_max, rounding, flags)
    self:PathFillConvex(col)
    local vert_end_idx = self.VtxBuffer.Size + 1
    ImGui.ShadeVertsLinearUV(self, vert_start_idx, vert_end_idx, p_min, p_max, uv_min, uv_max, true)

    if push_texture_id then
        self:PopTexture()
    end
end

--- @param radius float
function MT.ImDrawList:_CalcCircleAutoSegmentCount(radius)
    -- Automatic segment count
    local radius_idx = ImFloor(radius + 0.999) + 1 -- ceil to never reduce accuracy

    if radius_idx >= 1 and radius_idx <= 64 then -- IM_COUNTOF(_Data->CircleSegmentCounts)
        return self._Data.CircleSegmentCounts[radius_idx] -- Use cached value
    else
        return IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(radius, self._Data.CircleTessellationMaxError)
    end
end

-- Render-level scissoring. This is passed down to your render function but not used for CPU-side coarse clipping. Prefer using higher-level ImGui.PushClipRect() to affect logic (hit-testing and widget culling)
function MT.ImDrawList:PushClipRect(cr_min, cr_max, intersect_with_current_clip_rect)
    local cr = ImVec4(cr_min.x, cr_min.y, cr_max.x, cr_max.y)

    if intersect_with_current_clip_rect then
        local current = self._CmdHeader.ClipRect

        if cr.x < current.x then cr.x = current.x end -- = ClipWith(). Note that passing inverted range wouldn't be fixed here.
        if cr.y < current.y then cr.y = current.y end
        if cr.z > current.z then cr.z = current.z end
        if cr.w > current.w then cr.w = current.w end
    end

    cr.z = math.max(cr.x, cr.z)
    cr.w = math.max(cr.y, cr.w)

    -- [Luau] inline self._ClipRectStack:push_back(cr)
    local stack = self._ClipRectStack
    local n = stack.Size + 1
    if n > stack.Capacity then stack:push_back(cr) else stack.Data[n] = cr; stack.Size = n end
    ImVec4_Copy(self._CmdHeader.ClipRect, cr)
    self:_OnChangedClipRect()
end

function MT.ImDrawList:PopClipRect()
    local stack = self._ClipRectStack
    IM_ASSERT(stack.Size > 0)
    stack.Size = stack.Size - 1 -- [Luau] inline pop_back()
    if (stack.Size == 0) then -- LUA: No "Ternary Operator"
        ImVec4_Copy(self._CmdHeader.ClipRect, self._Data.ClipRectFullscreen)
    else
        ImVec4_Copy(self._CmdHeader.ClipRect, stack.Data[stack.Size])
    end
    self:_OnChangedClipRect()
end

--- @param center       ImVec2
--- @param radius       float
--- @param a_min_sample int
--- @param a_max_sample int
--- @param a_step       int
-- [Luau] scalar center (cx, cy); assigned to the forward-declared local, _PathArcToFastEx() wraps it

function _PathArcToFastExXY(self, cx, cy, radius, a_min_sample, a_max_sample, a_step)
    if radius < 0.5 then
        PathLineToXY(self, cx, cy)
        return
    end

    -- Calculate arc auto segment step size
    if a_step <= 0 then
        a_step = math.floor(IM_DRAWLIST_ARCFAST_SAMPLE_MAX / self:_CalcCircleAutoSegmentCount(radius))
    end

    -- Make sure we never do steps larger than one quarter of the circle
    a_step = ImClamp(a_step, 1, math.floor(IM_DRAWLIST_ARCFAST_TABLE_SIZE / 4))

    local sample_range = ImAbs(a_max_sample - a_min_sample)
    local a_next_step = a_step

    local samples = sample_range + 1
    local extra_max_sample = false
    if a_step > 1 then
        samples = math.floor(sample_range / a_step) + 1
        local overstep = sample_range % a_step

        if overstep > 0 then
            extra_max_sample = true
            samples = samples + 1

            -- When we have overstep to avoid awkwardly looking one long line and one tiny one at the end,
            -- distribute first step range evenly between them by reducing first step size.
            if sample_range > 0 then
                a_step = a_step - math.floor((a_step - overstep) / 2)
            end
        end
    end

    self._Path:resize(self._Path.Size + samples)
    local out_ptr = self._Path.Size - samples + 1

    local path_data, arc_fast_vtx = self._Path.Data, self._Data.ArcFastVtx -- [Luau] cache
    local sample_index = a_min_sample
    if sample_index < 0 or sample_index >= IM_DRAWLIST_ARCFAST_SAMPLE_MAX then
        sample_index = sample_index % IM_DRAWLIST_ARCFAST_SAMPLE_MAX
        if sample_index < 0 then
            sample_index = sample_index + IM_DRAWLIST_ARCFAST_SAMPLE_MAX
        end
    end

    if a_max_sample >= a_min_sample then
        local a = a_min_sample
        while a <= a_max_sample do
            -- a_step is clamped to IM_DRAWLIST_ARCFAST_SAMPLE_MAX, so we have guaranteed that it will not wrap over range twice or more
            if sample_index >= IM_DRAWLIST_ARCFAST_SAMPLE_MAX then
                sample_index = sample_index - IM_DRAWLIST_ARCFAST_SAMPLE_MAX
            end

            local s = arc_fast_vtx[sample_index + 1]
            local d = path_data[out_ptr]
            d.x = cx + s.x * radius; d.y = cy + s.y * radius
            out_ptr = out_ptr + 1

            a = a + a_step
            sample_index = sample_index + a_step
            a_step = a_next_step
        end
    else
        local a = a_min_sample
        while a >= a_max_sample do
            -- a_step is clamped to IM_DRAWLIST_ARCFAST_SAMPLE_MAX, so we have guaranteed that it will not wrap over range twice or more
            if sample_index < 0 then
                sample_index = sample_index + IM_DRAWLIST_ARCFAST_SAMPLE_MAX
            end

            local s = arc_fast_vtx[sample_index + 1]
            local d = path_data[out_ptr]
            d.x = cx + s.x * radius; d.y = cy + s.y * radius
            out_ptr = out_ptr + 1

            a = a - a_step
            sample_index = sample_index - a_step
            a_step = a_next_step
        end
    end

    if extra_max_sample then
        local normalized_max_sample = a_max_sample % IM_DRAWLIST_ARCFAST_SAMPLE_MAX
        if normalized_max_sample < 0 then
            normalized_max_sample = normalized_max_sample + IM_DRAWLIST_ARCFAST_SAMPLE_MAX
        end

        local s = arc_fast_vtx[normalized_max_sample + 1]
        local d = path_data[out_ptr]
        d.x = cx + s.x * radius; d.y = cy + s.y * radius
        out_ptr = out_ptr + 1
    end

    IM_ASSERT_PARANOID(self._Path.Size == out_ptr - 1)
end

function MT.ImDrawList:_PathArcToFastEx(center, radius, a_min_sample, a_max_sample, a_step)
    _PathArcToFastExXY(self, center.x, center.y, radius, a_min_sample, a_max_sample, a_step)
end

-- 0: East, 3: South, 6: West, 9: North, 12: East

function MT.ImDrawList:PathArcToFast(center, radius, a_min_of_12, a_max_of_12)
    if radius < 0.5 then
        self._Path:push_back(center)
        return
    end

    _PathArcToFastExXY(self, center.x, center.y, radius, a_min_of_12 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, a_max_of_12 * IM_DRAWLIST_ARCFAST_SAMPLE_MAX / 12, 0)
end

--- @param center       ImVec2
--- @param radius       float
--- @param a_min        float
--- @param a_max        float
--- @param num_segments int
function MT.ImDrawList:_PathArcToN(center, radius, a_min, a_max, num_segments)
    if radius < 0.5 then
        self._Path:push_back(center)
        return
    end

    -- Note that we are adding a point at both a_min and a_max.
    -- If you are trying to draw a full closed circle you don't want the overlapping points!
    local path = self._Path
    path:reserve(path.Size + (num_segments + 1))
    -- [Luau] write into the reserved ImVec2 slots: no temporary ImVec2, no push_back() method lookups
    local data, size = path.Data, path.Size
    for i = 0, num_segments do
        local a = a_min + (i / num_segments) * (a_max - a_min)
        size = size + 1
        local p = data[size]
        p.x = center.x + ImCos(a) * radius; p.y = center.y + ImSin(a) * radius
    end
    path.Size = size
end

--- @param center        ImVec2
--- @param radius        float
--- @param a_min         float
--- @param a_max         float
--- @param num_segments? int
function MT.ImDrawList:PathArcTo(center, radius, a_min, a_max, num_segments)
    if num_segments == nil then num_segments = 0 end

    if radius < 0.5 then
        self._Path:push_back(center)
        return
    end

    if num_segments > 0 then
        self:_PathArcToN(center, radius, a_min, a_max, num_segments)
        return
    end

    -- Automatic segment count
    if radius <= self._Data.ArcFastRadiusCutoff then
        local a_is_reverse = a_max < a_min

        -- We are going to use precomputed values for mid samples.
        -- Determine first and last sample in lookup table that belong to the arc.
        local a_min_sample_f = IM_DRAWLIST_ARCFAST_SAMPLE_MAX * a_min / (IM_PI * 2.0)
        local a_max_sample_f = IM_DRAWLIST_ARCFAST_SAMPLE_MAX * a_max / (IM_PI * 2.0)

        local a_min_sample = a_is_reverse and ImFloor(a_min_sample_f) or ImCeil(a_min_sample_f)
        local a_max_sample = a_is_reverse and ImCeil(a_max_sample_f) or ImFloor(a_max_sample_f)
        local a_mid_samples = a_is_reverse and ImMax(a_min_sample - a_max_sample, 0) or ImMax(a_max_sample - a_min_sample, 0)

        local a_min_segment_angle = a_min_sample * IM_PI * 2.0 / IM_DRAWLIST_ARCFAST_SAMPLE_MAX
        local a_max_segment_angle = a_max_sample * IM_PI * 2.0 / IM_DRAWLIST_ARCFAST_SAMPLE_MAX
        local a_emit_start = ImAbs(a_min_segment_angle - a_min) >= 1e-5
        local a_emit_end = ImAbs(a_max - a_max_segment_angle) >= 1e-5

        self._Path:reserve(self._Path.Size + (a_mid_samples + 1 + (a_emit_start and 1 or 0) + (a_emit_end and 1 or 0)))

        if a_emit_start      then PathLineToXY(self, center.x + ImCos(a_min) * radius, center.y + ImSin(a_min) * radius) end -- [Luau] no temporary ImVec2
        if a_mid_samples > 0 then _PathArcToFastExXY(self, center.x, center.y, radius, a_min_sample, a_max_sample, 0) end
        if a_emit_end        then PathLineToXY(self, center.x + ImCos(a_max) * radius, center.y + ImSin(a_max) * radius) end
    else
        local arc_length = ImAbs(a_max - a_min)
        local circle_segment_count = self:_CalcCircleAutoSegmentCount(radius)
        local arc_segment_count = ImMax(ImCeil(circle_segment_count * arc_length / (IM_PI * 2.0)), 1)

        self:_PathArcToN(center, radius, a_min, a_max, arc_segment_count)
    end
end

-- Note: as with every ImDrawList drawing function, this expects that the font atlas texture is bound.
-- DO NOT CALL DIRECTLY THIS WILL CHANGE WILDLY IN 2026. Use ImDrawList:AddText().
--- @param draw_list   ImDrawList
--- @param size        float
--- @param pos         ImVec2
--- @param col         ImU32
--- @param clip_rect   ImVec4
--- @param text        ImString
--- @param text_begin  int
--- @param text_end    int
--- @param wrap_width? float
--- @param flags?      ImDrawTextFlags

function MT.ImFont:RenderText(draw_list, size, pos, col, clip_rect, text, text_begin, text_end, wrap_width, flags)
    if wrap_width == nil then wrap_width = .0 end
    if flags      == nil then flags      = 0  end

    -- Align to be pixel perfect
    local x = pos.x
    local y = pos.y
    if y > clip_rect.w then
        return
    end
    if bit32.band(draw_list.Flags, ImDrawListFlags.TextNoPixelSnap) == 0 then
        x = IM_TRUNC(x)
        y = IM_TRUNC(y)
    end

    -- if not text_end then
    -- end

    local line_height = size
    local baked = self:GetFontBaked(size)

    local scale = size / baked.Size
    local origin_x = x
    local word_wrap_enabled = (wrap_width > 0.0)

    -- Fast-forward to first visible line
    local s = text_begin
    if y + line_height < clip_rect.y then
        while y + line_height < clip_rect.y and s < text_end do
            local line_end = ImMemchr(text, '\n', s)
            if word_wrap_enabled then
                -- FIXME-OPT: This is not optimal as do first do a search for \n before calling CalcWordWrapPosition().
                -- If the specs for CalcWordWrapPosition() were reworked to optionally return on \n we could combine both.
                -- However it is still better than nothing performing the fast-forward!
                s = ImFontCalcWordWrapPositionEx(self, size, text, s, (line_end ~= nil) and line_end or text_end, wrap_width, flags)
                s = ImTextCalcWordWrapNextLineStart(text, s, text_end, flags)
            else
                s = (line_end ~= nil) and (line_end + 1) or text_end
            end

            y = y + line_height
        end
    end

    -- For large text, scan for the last visible line in order to avoid over-reserving in the call to PrimReserve()
    -- Note that very large horizontal line will still be affected by the issue (e.g. a one megabyte string buffer without a newline will likely crash atm)
    if text_end - s > 1e4 and not word_wrap_enabled then
        local s_end = s
        local y_end = y
        while (y_end < clip_rect.w and s_end < text_end) do
            local _end = ImMemchr(text, '\n', s_end)
            s_end = (_end ~= nil) and (_end + 1) or text_end
            y_end = y_end + line_height
        end

        text_end = s_end
    end

    if s == text_end then
        return
    end

    -- Reserve vertices for remaining worse case (over-reserving is useful and easily amortized)
    local vtx_count_max = (text_end - s) * 4
    local idx_count_max = (text_end - s) * 6
    local idx_expected_size = draw_list.IdxBuffer.Size + idx_count_max
    draw_list:PrimReserve(idx_count_max, vtx_count_max)
    local vtx_write = draw_list._VtxWritePtr
    local idx_write = draw_list._IdxWritePtr
    local vtx_index = draw_list._VtxCurrentIdx
    local cmd_count = draw_list.CmdBuffer.Size
    local cpu_fine_clip = bit32.band(flags, ImDrawTextFlags.CpuFineClip) ~= 0

    local idx_data = draw_list.IdxBuffer.Data; local vtx_data = draw_list.VtxBuffer.Buf

    local color_untinted = bit32.bor(col, bit32.bnot(IM_COL32_A_MASK))

    local word_wrap_eol
    local stop = false
    local text_is_str = type(text) == "string"
    local lookup, lookup_n, glyphs = baked.IndexLookup.Data, baked.IndexLookup.Size, baked.Glyphs.Data

    while s < text_end do
        repeat
        if word_wrap_enabled then
            -- Calculate how far we can render. Requires two passes on the string data but keeps the code simple and not intrusive for what's essentially an uncommon feature.
            if not word_wrap_eol then
                word_wrap_eol = ImFontCalcWordWrapPositionEx(self, size, text, s, text_end, wrap_width - (x - origin_x), flags)
                lookup, lookup_n, glyphs = baked.IndexLookup.Data, baked.IndexLookup.Size, baked.Glyphs.Data -- [Luau] may have loaded glyphs
            end

            if s >= word_wrap_eol then
                x = origin_x
                y = y + line_height
                if y > clip_rect.w then
                    stop = true; break -- break out of main loop
                end
                word_wrap_eol = nil
                s = ImTextCalcWordWrapNextLineStart(text, s, text_end, flags) -- Wrapping skips upcoming blanks

                break
            end
        end

        -- Decode and advance source
        local c
        if text_is_str then c = string.byte(text, s) else c = text[s] end
        if c < 0x80 then
            s = s + 1
        else
            local wanted, out_char = ImStd.ImTextCharFromUtf8(text, s, text_end)
            c = out_char
            s = s + wanted
        end

        if c < 32 then
            if c == 10 then -- '\n'
                x = origin_x
                y = y + line_height
                if y > clip_rect.w then
                    stop = true; break -- break out of main loop
                end

                break
            end

            if c == 13 then -- '\r'
                break
            end
        end

        local glyph
        local gi = (c < lookup_n) and lookup[c + 1] or nil
        if gi ~= nil and gi ~= IM_FONTGLYPH_INDEX_NOT_FOUND and gi ~= IM_FONTGLYPH_INDEX_UNUSED then
            glyph = glyphs[gi]
        else
            glyph = baked:FindGlyph(c) -- may load the glyph and grow the tables
            lookup, lookup_n, glyphs = baked.IndexLookup.Data, baked.IndexLookup.Size, baked.Glyphs.Data
        end

        local char_width = glyph.AdvanceX * scale
        if glyph.Visible then
            -- We don't do a second finer clipping test on the Y axis as we've already skipped anything before clip_rect.y and exit once we pass clip_rect.w
            local x1 = x + glyph.X0 * scale
            local x2 = x + glyph.X1 * scale
            local y1 = y + glyph.Y0 * scale
            local y2 = y + glyph.Y1 * scale
            if x1 <= clip_rect.z and x2 >= clip_rect.x then
                -- Render a character
                local u1 = glyph.U0
                local v1 = glyph.V0
                local u2 = glyph.U1
                local v2 = glyph.V1

                -- CPU side clipping used to fit text in their frame when the frame is too small. Only does clipping for axis aligned quads.
                if (cpu_fine_clip) then
                    if (x1 < clip_rect.x) then
                        u1 = u1 + (1.0 - (x2 - clip_rect.x) / (x2 - x1)) * (u2 - u1)
                        x1 = clip_rect.x
                    end
                    if (y1 < clip_rect.y) then
                        v1 = v1 + (1.0 - (y2 - clip_rect.y) / (y2 - y1)) * (v2 - v1)
                        y1 = clip_rect.y
                    end
                    if (x2 > clip_rect.z) then
                        u2 = u1 + ((clip_rect.z - x1) / (x2 - x1)) * (u2 - u1)
                        x2 = clip_rect.z
                    end
                    if (y2 > clip_rect.w) then
                        v2 = v1 + ((clip_rect.w - y1) / (y2 - y1)) * (v2 - v1)
                        y2 = clip_rect.w
                    end
                    if (y1 >= y2) then
                        x = x + char_width

                        break
                    end
                end

                -- Support for untinted glyphs
                local glyph_col = glyph.Colored and color_untinted or col

                -- We are NOT calling PrimRectUV() here because non-inlined causes too much overhead in a debug builds. Inlined here:
                do
                    local o = (vtx_write - 1) * 36
                    writef64(vtx_data, o, x1); writef64(vtx_data, o + 8, y1); writef64(vtx_data, o + 16, u1); writef64(vtx_data, o + 24, v1); writeu32(vtx_data, o + 32, glyph_col)
                    writef64(vtx_data, o + 36, x2); writef64(vtx_data, o + 44, y1); writef64(vtx_data, o + 52, u2); writef64(vtx_data, o + 60, v1); writeu32(vtx_data, o + 68, glyph_col)
                    writef64(vtx_data, o + 72, x2); writef64(vtx_data, o + 80, y2); writef64(vtx_data, o + 88, u2); writef64(vtx_data, o + 96, v2); writeu32(vtx_data, o + 104, glyph_col)
                    writef64(vtx_data, o + 108, x1); writef64(vtx_data, o + 116, y2); writef64(vtx_data, o + 124, u1); writef64(vtx_data, o + 132, v2); writeu32(vtx_data, o + 140, glyph_col)
                    idx_data[idx_write + 0] = vtx_index; idx_data[idx_write + 1] = vtx_index + 1; idx_data[idx_write + 2] = vtx_index + 2;
                    idx_data[idx_write + 3] = vtx_index; idx_data[idx_write + 4] = vtx_index + 2; idx_data[idx_write + 5] = vtx_index + 3;
                    vtx_write = vtx_write + 4
                    vtx_index = vtx_index + 4
                    idx_write = idx_write + 6
                end
            end
        end

        x = x + char_width

        until true
        if stop then break end
    end

    -- Edge case: calling RenderText() with unloaded glyphs triggering texture change. It doesn't happen via ImGui.* calls because CalcTextSize() is always used.
    if cmd_count ~= draw_list.CmdBuffer.Size then
        IM_ASSERT(draw_list.CmdBuffer.Data[draw_list.CmdBuffer.Size].ElemCount == 0)
        draw_list.CmdBuffer:pop_back()
        draw_list:PrimUnreserve(idx_count_max, vtx_count_max)
        draw_list:AddDrawCmd()

        return self:RenderText(draw_list, size, pos, col, clip_rect, text, text_begin, text_end, wrap_width, flags) -- was `goto begin`
    end

    -- Give back unused vertices (clipped ones, blanks) ~ this is essentially a PrimUnreserve() action.
    draw_list.VtxBuffer.Size = vtx_write - 1 -- Same as calling shrink()
    draw_list.IdxBuffer.Size = idx_write - 1
    draw_list.CmdBuffer.Data[draw_list.CmdBuffer.Size].ElemCount = draw_list.CmdBuffer.Data[draw_list.CmdBuffer.Size].ElemCount - (idx_expected_size - draw_list.IdxBuffer.Size)
    draw_list._VtxWritePtr = vtx_write
    draw_list._IdxWritePtr = idx_write
    draw_list._VtxCurrentIdx = vtx_index
end

-------------------------------------------------------------------------------
-- [SECTION] ImGui Internal Render Helpers
-------------------------------------------------------------------------------
-- Vaguely redesigned to stop accessing ImGui global state:
-- - RenderArrow()
-- - RenderBullet()
-- - RenderCheckMark()
-- - RenderArrowPointingAt()
-- - RenderRectFilledInRangeH()
-- - RenderRectFilledWithHole()
-------------------------------------------------------------------------------
-- Function in need of a redesign (legacy mess)
-- - RenderColorRectWithAlphaCheckerboard()
-------------------------------------------------------------------------------

-- Render an arrow aimed to be aligned with text (p_min is a position in the same space text would be positioned). To e.g. denote expanded/collapsed state
--- @param draw_list ImDrawList
--- @param pos       ImVec2
--- @param color     ImU32
--- @param dir       ImGuiDir
--- @param scale?    float
local arrow_a, arrow_b, arrow_c = ImVec2(), ImVec2(), ImVec2() -- scratch: the path is consumed by AddTriangleFilled before returning

function ImGui.RenderArrow(draw_list, pos, color, dir, scale)
    if scale == nil then scale = 1.0 end

    local h = draw_list._Data.FontSize * 1.00
    local r = h * 0.40 * scale

    local cx, cy = pos.x + h * 0.50, pos.y + h * 0.50 * scale

    local ax, ay, bx, by, qx, qy
    if dir == ImGuiDir.Up or dir == ImGuiDir.Down then
        if dir == ImGuiDir.Up then r = -r end
        ax, ay = 0.000 * r, 0.750 * r
        bx, by = -0.866 * r, -0.750 * r
        qx, qy = 0.866 * r, -0.750 * r
    elseif dir == ImGuiDir.Left or dir == ImGuiDir.Right then
        if dir == ImGuiDir.Left then r = -r end
        ax, ay = 0.750 * r, 0.000 * r
        bx, by = -0.750 * r, 0.866 * r
        qx, qy = -0.750 * r, -0.866 * r
    else
        IM_ASSERT(false)
    end

    arrow_a.x, arrow_a.y = cx + ax, cy + ay
    arrow_b.x, arrow_b.y = cx + bx, cy + by
    arrow_c.x, arrow_c.y = cx + qx, cy + qy
    draw_list:AddTriangleFilled(arrow_a, arrow_b, arrow_c, color)
end

--- @param draw_list ImDrawList
--- @param pos       ImVec2
--- @param col       ImU32
function ImGui.RenderBullet(draw_list, pos, col)
    -- FIXME-OPT: This should be baked in font now that it's easier.
    local font_size = draw_list._Data.FontSize
    draw_list:AddCircleFilled(pos, font_size * 0.20, col, (font_size < 22) and 8 or ((font_size < 40) and 12 or 0)) -- Hardcode optimal/nice tessellation threshold
end

--- @param draw_list ImDrawList
--- @param pos       ImVec2
--- @param col       ImU32
--- @param sz        float
local checkmark_p = ImVec2() -- [Luau] scratch: PathLineTo() copies the point

function ImGui.RenderCheckMark(draw_list, pos, col, sz)
    local thickness = math.max(sz / 5.0, 1.0)
    sz = sz - thickness * 0.5
    local pos_x, pos_y = pos.x + thickness * 0.25, pos.y + thickness * 0.25 -- [Luau] scalar pos

    local third = sz / 3.0
    local bx = pos_x + third
    local by = pos_y + sz - third * 0.5

    local p = checkmark_p
    p.x = bx - third; p.y = by - third
    draw_list:PathLineTo(p)
    p.x = bx; p.y = by
    draw_list:PathLineTo(p)
    p.x = bx + third * 2.0; p.y = by - third * 2.0
    draw_list:PathLineTo(p)
    draw_list:PathStroke(col, thickness)
end

-- Render an arrow. 'pos' is position of the arrow tip. half_sz.x is length from base to tip. half_sz.y is length on each side.
--- @param draw_list ImDrawList
--- @param pos       ImVec2
--- @param half_sz   ImVec2
--- @param direction ImGuiDir
--- @param col       ImU32
function ImGui.RenderArrowPointingAt(draw_list, pos, half_sz, direction, col)
    if direction == ImGuiDir.Left then
        draw_list:AddTriangleFilled(ImVec2(pos.x + half_sz.x, pos.y - half_sz.y), ImVec2(pos.x + half_sz.x, pos.y + half_sz.y), pos, col)
    elseif direction == ImGuiDir.Right then
        draw_list:AddTriangleFilled(ImVec2(pos.x - half_sz.x, pos.y + half_sz.y), ImVec2(pos.x - half_sz.x, pos.y - half_sz.y), pos, col)
    elseif direction == ImGuiDir.Up then
        draw_list:AddTriangleFilled(ImVec2(pos.x + half_sz.x, pos.y + half_sz.y), ImVec2(pos.x - half_sz.x, pos.y + half_sz.y), pos, col)
    elseif direction == ImGuiDir.Down then
        draw_list:AddTriangleFilled(ImVec2(pos.x - half_sz.x, pos.y - half_sz.y), ImVec2(pos.x + half_sz.x, pos.y - half_sz.y), pos, col)
    elseif direction == ImGuiDir.None or direction == ImGuiDir.COUNT then -- Fix warnings
    end
end

local function ImAcos01(x)
    if x <= 0.0 then return IM_PI * 0.5 end
    if x >= 1.0 then return 0.0 end
    return ImAcos(x)
    --return (-0.69813170079773212 * x * x - 0.87266462599716477) * x + 1.5707963267948966 -- Cheap approximation, may be enough for what we do.
end

-- FIXME: Cleanup and move code to ImDrawList.
-- - Before 2025-12-04: RenderRectFilledRangeH()   with 'float x_start_norm, float x_end_norm` <- normalized
-- - After  2025-12-04: RenderRectFilledInRangeH() with 'float x1, float x2'                   <- absolute coords!!
--- @param draw_list ImDrawList
--- @param rect      ImRect
--- @param col       ImU32
--- @param fill_x0   float
--- @param fill_x1   float
--- @param rounding  float
function ImGui.RenderRectFilledInRangeH(draw_list, rect, col, fill_x0, fill_x1, rounding)
    if fill_x0 > fill_x1 then
        return
    end

    local p0 = ImVec2(fill_x0, rect.Min.y)
    local p1 = ImVec2(fill_x1, rect.Max.y)

    if rounding == 0.0 then
        draw_list:AddRectFilled(p0, p1, col, 0.0)
        return
    end

    rounding = ImClamp(ImMin((rect.Max.x - rect.Min.x) * 0.5, (rect.Max.y - rect.Min.y) * 0.5) - 1.0, 0.0, rounding)
    local inv_rounding = 1.0 / rounding
    local arc0_b = ImAcos01(1.0 - (p0.x - rect.Min.x) * inv_rounding)
    local arc0_e = ImAcos01(1.0 - (p1.x - rect.Min.x) * inv_rounding)
    local half_pi = IM_PI * 0.5 -- We will == compare to this because we know this is the exact value ImAcos01 can return.
    local x0 = ImMax(p0.x, rect.Min.x + rounding)

    if arc0_b == arc0_e then
        draw_list:PathLineTo(ImVec2(x0, p1.y))
        draw_list:PathLineTo(ImVec2(x0, p0.y))
    elseif arc0_b == 0.0 and arc0_e == half_pi then
        draw_list:PathArcToFast(ImVec2(x0, p1.y - rounding), rounding, 3, 6) -- BL
        draw_list:PathArcToFast(ImVec2(x0, p0.y + rounding), rounding, 6, 9) -- TR
    else
        draw_list:PathArcTo(ImVec2(x0, p1.y - rounding), rounding, math.pi - arc0_e, math.pi - arc0_b) -- BL
        draw_list:PathArcTo(ImVec2(x0, p0.y + rounding), rounding, math.pi + arc0_b, math.pi + arc0_e) -- TR
    end

    if p1.x > rect.Min.x + rounding then
        local arc1_b = ImAcos01(1.0 - (rect.Max.x - p1.x) * inv_rounding)
        local arc1_e = ImAcos01(1.0 - (rect.Max.x - p0.x) * inv_rounding)
        local x1 = ImMin(p1.x, rect.Max.x - rounding)

        if arc1_b == arc1_e then
            draw_list:PathLineTo(ImVec2(x1, p0.y))
            draw_list:PathLineTo(ImVec2(x1, p1.y))
        elseif arc1_b == 0.0 and arc1_e == half_pi then
            draw_list:PathArcToFast(ImVec2(x1, p0.y + rounding), rounding, 9, 12) -- TR
            draw_list:PathArcToFast(ImVec2(x1, p1.y - rounding), rounding, 0, 3)  -- BR
        else
            draw_list:PathArcTo(ImVec2(x1, p0.y + rounding), rounding, -arc1_e, -arc1_b) -- TR
            draw_list:PathArcTo(ImVec2(x1, p1.y - rounding), rounding, arc1_b, arc1_e)   -- BR
        end
    end

    draw_list:PathFillConvex(col)
end

--- @param r_in      ImRect
--- @param r_outer   ImRect
--- @param threshold float
--- @return ImDrawFlags
function ImGui.CalcRoundingFlagsForRectInRect(r_in, r_outer, threshold)
    local round_l = r_in.Min.x <= r_outer.Min.x + threshold
    local round_r = r_in.Max.x >= r_outer.Max.x - threshold
    local round_t = r_in.Min.y <= r_outer.Min.y + threshold
    local round_b = r_in.Max.y >= r_outer.Max.y - threshold

    local flags = ImDrawFlags.RoundCornersNone

    if round_t and round_l then
        flags = bit32.bor(flags, ImDrawFlags.RoundCornersTopLeft)
    end
    if round_t and round_r then
        flags = bit32.bor(flags, ImDrawFlags.RoundCornersTopRight)
    end
    if round_b and round_l then
        flags = bit32.bor(flags, ImDrawFlags.RoundCornersBottomLeft)
    end
    if round_b and round_r then
        flags = bit32.bor(flags, ImDrawFlags.RoundCornersBottomRight)
    end

    return flags
end

-- Helper for ColorPicker4()
-- NB: This is rather brittle and will show artifact when rounding this enabled if rounded corners overlap multiple cells. Caller currently responsible for avoiding that.
-- Spent a non reasonable amount of time trying to getting this right for ColorButton with rounding+anti-aliasing+ImGuiColorEditFlags_HalfAlphaPreview flag + various grid sizes and offsets, and eventually gave up... probably more reasonable to disable rounding altogether.
-- FIXME: uses ImGui.GetColorU32
--- @param draw_list ImDrawList
--- @param p_min     ImVec2
--- @param p_max     ImVec2
--- @param col       ImU32
--- @param grid_step float
--- @param grid_off  ImVec2
--- @param rounding? float
--- @param flags?    ImDrawFlags
function ImGui.RenderColorRectWithAlphaCheckerboard(draw_list, p_min, p_max, col, grid_step, grid_off, rounding, flags)
    if rounding == nil then rounding = 0.0 end
    if flags    == nil then flags    = 0   end

    if bit32.band(flags, ImDrawFlags.RoundCornersMask_) == 0 then
        flags = ImDrawFlags.RoundCornersDefault_
    end

    if bit32.rshift(bit32.band(col, IM_COL32_A_MASK), IM_COL32_A_SHIFT) < 0xFF then
        local col_bg1 = ImGui.GetColorU32(ImStd.ImAlphaBlendColors(IM_COL32(128, 128, 128, 255), col), nil, true)
        local col_bg2 = ImGui.GetColorU32(ImStd.ImAlphaBlendColors(IM_COL32(204, 204, 204, 255), col), nil, true)
        draw_list:AddRectFilled(p_min, p_max, col_bg1, rounding, flags)

        local yi = 0
        local y = p_min.y + grid_off.y
        local x_start
        local x
        local cell_flags
        while y < p_max.y do
            repeat
            local y1 = ImClamp(y, p_min.y, p_max.y)
            local y2 = ImMin(y + grid_step, p_max.y)

            if y2 <= y1 then
                break
            end

            x_start = p_min.x + grid_off.x + ((yi + 1) % 2) * grid_step
            x = x_start
            while x < p_max.x do
                repeat
                local x1 = ImClamp(x, p_min.x, p_max.x)
                local x2 = ImMin(x + grid_step, p_max.x)

                if x2 <= x1 then
                    break
                end

                cell_flags = ImDrawFlags.RoundCornersNone -- FIXME: Could use CalcRoundingFlagsForRectInRect()
                if y1 <= p_min.y then
                    if x1 <= p_min.x then cell_flags = bit32.bor(cell_flags, ImDrawFlags.RoundCornersTopLeft) end
                    if x2 >= p_max.x then cell_flags = bit32.bor(cell_flags, ImDrawFlags.RoundCornersTopRight) end
                end
                if y2 >= p_max.y then
                    if x1 <= p_min.x then cell_flags = bit32.bor(cell_flags, ImDrawFlags.RoundCornersBottomLeft) end
                    if x2 >= p_max.x then cell_flags = bit32.bor(cell_flags, ImDrawFlags.RoundCornersBottomRight) end
                end

                -- Combine flags
                if flags == ImDrawFlags.RoundCornersNone or cell_flags == ImDrawFlags.RoundCornersNone then
                    cell_flags = ImDrawFlags.RoundCornersNone
                else
                    cell_flags = bit32.band(cell_flags, flags)
                end
                draw_list:AddRectFilled(ImVec2(x1, y1), ImVec2(x2, y2), col_bg2, rounding, cell_flags)

                until true

                x = x + grid_step * 2.0
            end

            until true

            y = y + grid_step
            yi = yi + 1
        end
    else
        draw_list:AddRectFilled(p_min, p_max, col, rounding, flags)
    end
end



function ImGui.RenderRectFilledWithHole(draw_list, outer, inner, col, rounding)
    local fill_L = inner.Min.x > outer.Min.x
    local fill_R = inner.Max.x < outer.Max.x
    local fill_U = inner.Min.y > outer.Min.y
    local fill_D = inner.Max.y < outer.Max.y
    local D = ImDrawFlags
    local bor = bit32.bor
    local function f(c, v) return c and 0 or v end
    if fill_L then draw_list:AddRectFilled(ImVec2(outer.Min.x, inner.Min.y), ImVec2(inner.Min.x, inner.Max.y), col, rounding, bor(D.RoundCornersNone, f(fill_U, D.RoundCornersTopLeft), f(fill_D, D.RoundCornersBottomLeft))) end
    if fill_R then draw_list:AddRectFilled(ImVec2(inner.Max.x, inner.Min.y), ImVec2(outer.Max.x, inner.Max.y), col, rounding, bor(D.RoundCornersNone, f(fill_U, D.RoundCornersTopRight), f(fill_D, D.RoundCornersBottomRight))) end
    if fill_U then draw_list:AddRectFilled(ImVec2(inner.Min.x, outer.Min.y), ImVec2(inner.Max.x, inner.Min.y), col, rounding, bor(D.RoundCornersNone, f(fill_L, D.RoundCornersTopLeft), f(fill_R, D.RoundCornersTopRight))) end
    if fill_D then draw_list:AddRectFilled(ImVec2(inner.Min.x, inner.Max.y), ImVec2(inner.Max.x, outer.Max.y), col, rounding, bor(D.RoundCornersNone, f(fill_L, D.RoundCornersBottomLeft), f(fill_R, D.RoundCornersBottomRight))) end
    if fill_L and fill_U then draw_list:AddRectFilled(ImVec2(outer.Min.x, outer.Min.y), ImVec2(inner.Min.x, inner.Min.y), col, rounding, D.RoundCornersTopLeft) end
    if fill_R and fill_U then draw_list:AddRectFilled(ImVec2(inner.Max.x, outer.Min.y), ImVec2(outer.Max.x, inner.Min.y), col, rounding, D.RoundCornersTopRight) end
    if fill_L and fill_D then draw_list:AddRectFilled(ImVec2(outer.Min.x, inner.Max.y), ImVec2(inner.Min.x, outer.Max.y), col, rounding, D.RoundCornersBottomLeft) end
    if fill_R and fill_D then draw_list:AddRectFilled(ImVec2(inner.Max.x, inner.Max.y), ImVec2(outer.Max.x, outer.Max.y), col, rounding, D.RoundCornersBottomRight) end
end

-------------------------------------------------------------------------------
-- Extra primitives (Ngon, Ellipse, Bezier, concave fill)
-------------------------------------------------------------------------------
-- [port] These follow the 1.92 stroker this port uses (no ImDrawFlags_StrokeXXX placement flags).

function MT.ImDrawList:PathEllipticalArcTo(center, radius, rot, a_min, a_max, num_segments)
    if num_segments == nil or num_segments <= 0 then
        num_segments = self:_CalcCircleAutoSegmentCount(ImMax(radius.x, radius.y)) -- A bit pessimistic, maybe there's a better computation to do here.
    end
    local cos_rot, sin_rot = ImCos(rot), ImSin(rot)
    for i = 0, num_segments do
        local a = a_min + (i / num_segments) * (a_max - a_min)
        local px, py = ImCos(a) * radius.x, ImSin(a) * radius.y
        self._Path:push_back(ImVec2(px * cos_rot - py * sin_rot + center.x, px * sin_rot + py * cos_rot + center.y))
    end
end

function ImBezierCubicCalc(p1, p2, p3, p4, t)
    local u = 1.0 - t
    local w1, w2, w3, w4 = u * u * u, 3 * u * u * t, 3 * u * t * t, t * t * t
    return ImVec2(w1 * p1.x + w2 * p2.x + w3 * p3.x + w4 * p4.x, w1 * p1.y + w2 * p2.y + w3 * p3.y + w4 * p4.y)
end

function ImBezierQuadraticCalc(p1, p2, p3, t)
    local u = 1.0 - t
    local w1, w2, w3 = u * u, 2 * u * t, t * t
    return ImVec2(w1 * p1.x + w2 * p2.x + w3 * p3.x, w1 * p1.y + w2 * p2.y + w3 * p3.y)
end

-- Closely mimics ImBezierCubicClosestPointCasteljau() in imgui.cpp
local function PathBezierCubicCurveToCasteljau(path, x1, y1, x2, y2, x3, y3, x4, y4, tess_tol, level)
    local dx, dy = x4 - x1, y4 - y1
    local d2 = math.abs((x2 - x4) * dy - (y2 - y4) * dx)
    local d3 = math.abs((x3 - x4) * dy - (y3 - y4) * dx)
    if (d2 + d3) * (d2 + d3) < tess_tol * (dx * dx + dy * dy) then
        path:push_back(ImVec2(x4, y4))
    elseif level < 10 then
        local x12, y12 = (x1 + x2) * 0.5, (y1 + y2) * 0.5
        local x23, y23 = (x2 + x3) * 0.5, (y2 + y3) * 0.5
        local x34, y34 = (x3 + x4) * 0.5, (y3 + y4) * 0.5
        local x123, y123 = (x12 + x23) * 0.5, (y12 + y23) * 0.5
        local x234, y234 = (x23 + x34) * 0.5, (y23 + y34) * 0.5
        local x1234, y1234 = (x123 + x234) * 0.5, (y123 + y234) * 0.5
        PathBezierCubicCurveToCasteljau(path, x1, y1, x12, y12, x123, y123, x1234, y1234, tess_tol, level + 1)
        PathBezierCubicCurveToCasteljau(path, x1234, y1234, x234, y234, x34, y34, x4, y4, tess_tol, level + 1)
    end
end

local function PathBezierQuadraticCurveToCasteljau(path, x1, y1, x2, y2, x3, y3, tess_tol, level)
    local dx, dy = x3 - x1, y3 - y1
    local det = (x2 - x3) * dy - (y2 - y3) * dx
    if det * det * 4.0 < tess_tol * (dx * dx + dy * dy) then
        path:push_back(ImVec2(x3, y3))
    elseif level < 10 then
        local x12, y12 = (x1 + x2) * 0.5, (y1 + y2) * 0.5
        local x23, y23 = (x2 + x3) * 0.5, (y2 + y3) * 0.5
        local x123, y123 = (x12 + x23) * 0.5, (y12 + y23) * 0.5
        PathBezierQuadraticCurveToCasteljau(path, x1, y1, x12, y12, x123, y123, tess_tol, level + 1)
        PathBezierQuadraticCurveToCasteljau(path, x123, y123, x23, y23, x3, y3, tess_tol, level + 1)
    end
end

function MT.ImDrawList:PathBezierCubicCurveTo(p2, p3, p4, num_segments)
    local p1 = self._Path:back()
    if num_segments == nil or num_segments == 0 then
        PathBezierCubicCurveToCasteljau(self._Path, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, self._Data.CurveTessellationTol, 0) -- Auto-tessellated
    else
        local t_step = 1.0 / num_segments
        for i_step = 1, num_segments do self._Path:push_back(ImBezierCubicCalc(p1, p2, p3, p4, t_step * i_step)) end
    end
end

function MT.ImDrawList:PathBezierQuadraticCurveTo(p2, p3, num_segments)
    local p1 = self._Path:back()
    if num_segments == nil or num_segments == 0 then
        PathBezierQuadraticCurveToCasteljau(self._Path, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, self._Data.CurveTessellationTol, 0) -- Auto-tessellated
    else
        local t_step = 1.0 / num_segments
        for i_step = 1, num_segments do self._Path:push_back(ImBezierQuadraticCalc(p1, p2, p3, t_step * i_step)) end
    end
end

-- Guaranteed to honor 'num_segments'
function MT.ImDrawList:AddNgon(center, radius, col, num_segments, thickness)
    if thickness == nil then thickness = 1.0 end
    if bit32.band(col, IM_COL32_A_MASK) == 0 or num_segments <= 2 then return end
    -- Because we are filling a closed shape we remove 1 from the count of segments/points
    local a_max = (IM_PI * 2.0) * (num_segments - 1.0) / num_segments
    self:PathArcTo(center, radius - 0.5, 0.0, a_max, num_segments - 1)
    self:PathStroke(col, thickness, ImDrawFlags.Closed)
end

-- Guaranteed to honor 'num_segments'
function MT.ImDrawList:AddNgonFilled(center, radius, col, num_segments)
    if bit32.band(col, IM_COL32_A_MASK) == 0 or num_segments <= 2 then return end
    -- Because we are filling a closed shape we remove 1 from the count of segments/points
    local a_max = (IM_PI * 2.0) * (num_segments - 1.0) / num_segments
    self:PathArcTo(center, radius, 0.0, a_max, num_segments - 1)
    self:PathFillConvex(col)
end

-- Ellipse
function MT.ImDrawList:AddEllipse(center, radius, col, rot, num_segments, thickness)
    if rot == nil then rot = 0.0 end
    if thickness == nil then thickness = 1.0 end
    if bit32.band(col, IM_COL32_A_MASK) == 0 then return end
    if num_segments == nil or num_segments <= 0 then num_segments = self:_CalcCircleAutoSegmentCount(ImMax(radius.x, radius.y)) end -- A bit pessimistic, maybe there's a better computation to do here.
    -- Because we are filling a closed shape we remove 1 from the count of segments/points
    local a_max = IM_PI * 2.0 * (num_segments - 1.0) / num_segments
    self:PathEllipticalArcTo(center, radius, rot, 0.0, a_max, num_segments - 1)
    self:PathStroke(col, thickness, ImDrawFlags.Closed)
end

function MT.ImDrawList:AddEllipseFilled(center, radius, col, rot, num_segments)
    if rot == nil then rot = 0.0 end
    if bit32.band(col, IM_COL32_A_MASK) == 0 then return end
    if num_segments == nil or num_segments <= 0 then num_segments = self:_CalcCircleAutoSegmentCount(ImMax(radius.x, radius.y)) end -- A bit pessimistic, maybe there's a better computation to do here.
    -- Because we are filling a closed shape we remove 1 from the count of segments/points
    local a_max = IM_PI * 2.0 * (num_segments - 1.0) / num_segments
    self:PathEllipticalArcTo(center, radius, rot, 0.0, a_max, num_segments - 1)
    self:PathFillConvex(col)
end

-- Cubic Bezier takes 4 controls points
function MT.ImDrawList:AddBezierCubic(p1, p2, p3, p4, col, thickness, num_segments)
    if bit32.band(col, IM_COL32_A_MASK) == 0 then return end
    self:PathLineTo(p1)
    self:PathBezierCubicCurveTo(p2, p3, p4, num_segments or 0)
    self:PathStroke(col, thickness or 1.0)
end

-- Quadratic Bezier takes 3 controls points
function MT.ImDrawList:AddBezierQuadratic(p1, p2, p3, col, thickness, num_segments)
    if bit32.band(col, IM_COL32_A_MASK) == 0 then return end
    self:PathLineTo(p1)
    self:PathBezierQuadraticCurveTo(p2, p3, num_segments or 0)
    self:PathStroke(col, thickness or 1.0)
end

-- ponytail: ear-clipping, no anti-aliased fringe (upstream's AA triangulator not ported). O(n^2) is fine for UI polygons.
--- @param points ImVec2[] # 1-based
function MT.ImDrawList:AddConcavePolyFilled(points, points_count, col)
    if points_count < 3 or bit32.band(col, IM_COL32_A_MASK) == 0 then return end
    local idx = {}
    local area = 0.0
    for i = 1, points_count do
        idx[i] = i
        local a, b = points[i], points[i % points_count + 1]
        area = area + (a.x * b.y - b.x * a.y)
    end
    local sign = (area >= 0) and 1 or -1
    local function cross(o, a, b) return (a.x - o.x) * (b.y - o.y) - (a.y - o.y) * (b.x - o.x) end
    local guard = 0
    while #idx > 3 and guard < points_count * points_count do
        guard = guard + 1
        local n = #idx
        local clipped = false
        for i = 1, n do
            local ia, ib, ic = idx[(i - 2) % n + 1], idx[i], idx[i % n + 1]
            local a, b, c = points[ia], points[ib], points[ic]
            if cross(a, b, c) * sign > 0 then
                local inside = false
                for j = 1, n do
                    local p = idx[j]
                    if p ~= ia and p ~= ib and p ~= ic then
                        local q = points[p]
                        if cross(a, b, q) * sign >= 0 and cross(b, c, q) * sign >= 0 and cross(c, a, q) * sign >= 0 then inside = true; break end
                    end
                end
                if not inside then
                    self:AddTriangleFilled(a, b, c, col)
                    table.remove(idx, i)
                    clipped = true
                    break
                end
            end
        end
        if not clipped then break end
    end
    if #idx == 3 then self:AddTriangleFilled(points[idx[1]], points[idx[2]], points[idx[3]], col) end
end

function MT.ImDrawList:PathFillConcave(col)
    self:AddConcavePolyFilled(self._Path.Data, self._Path.Size, col)
    self._Path.Size = 0
end

return true -- [Roblox] ModuleScripts must return exactly one value
end

__FILES['imgui_h.lua'] = function()
-- dear imgui, v1.93.0 WIP
-- (headers)

-- Help:
-- - Call and read ImGui.ShowDemoWindow() in imgui_demo.lua. All applications in examples/ are doing that.
-- - Read top of imgui.lua for more details, links and comments.

-- Resources:
-- - FAQ ........................ https://dearimgui.com/faq
-- - Homepage ................... https://github.com/ocornut/imgui
-- - Releases & Changelog ....... https://github.com/ocornut/imgui/releases
-- - Wiki ....................... https://github.com/ocornut/imgui/wiki (lots of good stuff there)
-- - Issues & support ........... https://github.com/ocornut/imgui/issues

-- Index of this file:
-- [SECTION] Forward declarations and basic types
-- [SECTION] METATABLE MANAGEMENT
-- [SECTION] Helpers: Debug log, memory allocations macros, ImVector<>
-- [SECTION] Drawing API (ImDrawCmd, ImDrawIdx, ImDrawVert, ImDrawChannel, ImDrawListSplitter, ImDrawFlags, ImDrawList, ImDrawData)
-- [SECTION] Texture API (ImTextureFormat, ImTextureStatus, ImTextureRect, ImTextureData)
-- [SECTION] Texture identifiers (ImTextureID, ImTextureRef)
-- [SECTION] Font API (ImFontConfig, ImFontGlyph, ImFontGlyphRangesBuilder, ImFontAtlasFlags, ImFontAtlas, ImFontBaked, ImFont)
-- [SECTION] ImGuiIO
-- [SECTION] Viewports
-- [SECTION] ImGuiPlatformIO + other Platform Dependent Interfaces (ImGuiPlatformMonitor, ImGuiPlatformImeData)
-- [SECTION] Flags & Enumerations
-- [SECTION] Misc data structures (ImGuiInputTextCallbackData, ImGuiSizeCallbackData, ImGuiPayload)
-- [SECTION] Tables API flags and structures (ImGuiTableFlags, ImGuiTableColumnFlags, ImGuiTableRowFlags, ImGuiTableBgTarget, ImGuiTableSortSpecs, ImGuiTableColumnSortSpecs)
-- [SECTION] Helpers (ImGuiOnceUponAFrame, ImGuiTextFilter, ImGuiTextBuffer, ImGuiStorage, ImGuiListClipper, Math Operators, ImColor)

--- @meta

local type   = ImGui._GetTypeFunc()
local rawget = rawget; local rawset = rawset

-- [LuaBitOp](https://bitop.luajit.org/semantics.html)
local bitAnd    = bit32.band; local bitOr = bit32.bor
local bitLShift = bit32.lshift

-------------------------------------------------------------------------------
-- [SECTION] Forward declarations and basic types
-------------------------------------------------------------------------------

-- Scalar data types
--- @class char          : integer
--- @class unsigned_char : integer

--- @alias ImS8 char
--- @alias ImU8 unsigned_char

--- @class ImU16 : integer
--- @class ImS16 : integer

--- @class ImU32 : integer
--- @class ImS32 : integer

--- @param val number
--- @return ImU8
function ImU8(val) return bitAnd(val, 0xFF) end
--- @param val number
--- @return ImS8
function ImS8(val) return bitAnd(val, 0xFF) - (bitAnd(val, 0x80) ~= 0 and 0x100 or 0) end

--- @param val number
--- @return ImU16
function ImU16(val) return bitAnd(val, 0xFFFF) end
--- @param val number
--- @return ImS16
function ImS16(val) return bitAnd(val, 0xFFFF) - (bitAnd(val, 0x8000) ~= 0 and 0x10000 or 0) end

--- @param val number
--- @return ImU32
function ImU32(val) return bitAnd(val, 0xFFFFFFFF) end
--- @param val number
--- @return ImS32
function ImS32(val) return bitAnd(val, 0xFFFFFFFF) end

--- @alias float          number
--- @class double : number

--- @alias int            integer
--- @alias unsigned_int   integer

--- @alias short          integer
--- @alias unsigned_short integer

--- @alias size_t unsigned_int

-- Character types
-- (we generally use UTF-8 encoded string in the API. This is storage specifically for a decoded character used for keyboard input and display)
--- @alias ImWchar16 unsigned_short
--- @alias ImWchar   ImWchar16

--- @alias bool boolean

-- A unique ID used by widgets (typically the result of hashing a stack of string)
--- @alias ImGuiID unsigned_int

-- ImTextureID = backend specific, low-level identifier for a texture uploaded in GPU/graphics system.
-- [Compile-time configurable type]
-- - When a Rendered Backend creates a texture, it store its native identifier into a ImTextureID value.
--   (e.g. Used by DX11 backend to a `ID3D11ShaderResourceView*`; Used by OpenGL backends to store `GLuint`;
--         Used by SDLGPU backend to store a `SDL_GPUTextureSamplerBinding*`, etc.).
-- - User may submit their own textures to e.g. ImGui.Image() function by passing this value.
-- - During the rendering loop, the Renderer Backend retrieve the ImTextureID, which stored inside a
--   ImTextureRef, which is stored inside a ImDrawCmd.
--- @alias ImTextureID integer

-- ImGuiKey | ImGuiMod_XXX: for IsKeyChordPressed(), Shortcut() etc. an ImGuiKey optionally OR-ed with one or more ImGuiMod_XXX values.
--- @alias ImGuiKeyChord int

-- ImDrawIdx: vertex index. [Compile-time configurable type]
--- @alias ImDrawIdx unsigned_int

-- Library Version
-- (Integer encoded as XYYZZ for use in conditionals, e.g. 'if IMGUI_VERSION_NUM >= 12345')
IMGUI_VERSION     = "1.93.0 WIP"
IMGUI_VERSION_NUM = 19298

-- Helper: Unicode defines
IM_UNICODE_CODEPOINT_INVALID = 0xFFFD -- Invalid Unicode code point (standard value).
IM_UNICODE_CODEPOINT_MAX     = 0xFFFF -- Maximum Unicode code point supported by this build.

-- IM_ALLOC(), IM_FREE(), IM_DELETE()
IM_ALLOC = ImGui.MemAlloc
IM_FREE = ImGui.MemFree

--- @param owner table
--- @param field string|int
IM_DELETE = function(owner, field) if owner[field] ~= nil then owner[field] = nil; ImGui.MemFree(owner, field); end end

-------------------------------------------------------------------------------
-- [SECTION] METATABLE MANAGEMENT
-------------------------------------------------------------------------------

--- File-scope metatable storage
local MT = {}

function ImGui.GetMetatables() return MT end

--- @param _EXPR any
--- @param _MSG  string?
function IM_ASSERT(_EXPR, _MSG) assert((_EXPR), _MSG) end

IM_ASSERT_PARANOID = IM_ASSERT

-- A primary data type
--- Note that `S64` and `U64` are not supported
--- @enum ImGuiDataType
ImGuiDataType =
{
    S8     = 0, -- signed char / char (with sensible compilers)
    U8     = 1, -- unsigned char
    S16    = 2, -- short
    U16    = 3, -- unsigned short
    S32    = 4, -- int
    U32    = 5, -- unsigned int
    Float  = 6, -- float
    Double = 7, -- double
    Bool   = 8, -- bool (provided for user convenience, not supported by scalar widgets)
    String = 9, -- string (provided for user convenience, not supported by scalar widgets)
    COUNT  = 10
}
-- Extend ImGuiDataType_
ImGuiDataType.Pointer = 11 -- [internal]
ImGuiDataType.ID      = 12 -- [internal]

ImTextureID_Invalid = -1

-- We intentionally support a limited amount of texture formats to limit burden on CPU-side code and extension.
-- Most standard backends only support RGBA32 but we provide a single channel option for low-resource/embedded systems.
--- @enum ImTextureFormat
ImTextureFormat =
{
    RGBA32 = 0, -- 4 components per pixel, each is unsigned 8-bit. Total size = TexWidth * TexHeight * 4
    Alpha8 = 1, -- 1 component per pixel, each is unsigned 8-bit. Total size = TexWidth * TexHeight
}

-- Status of a texture to communicate with Renderer Backend.
--- @enum ImTextureStatus
ImTextureStatus =
{
    OK          = 0,
    Destroyed   = 1, -- Backend destroyed the texture.
    WantCreate  = 2, -- Requesting backend to create the texture. Set status OK when done.
    WantUpdates = 3, -- Requesting backend to update specific blocks of pixels (write to texture portions which have never been used before). Set status OK when done.
    WantDestroy = 4, -- Requesting backend to destroy the texture. Set status to Destroyed when done.
}

-- Flags for ImFontAtlas build
--- @enum ImFontAtlasFlags
ImFontAtlasFlags =
{
    None               = 0,
    NoPowerOfTwoHeight = bitLShift(1, 0), -- Don't round the height to next power of two
    NoMouseCursors     = bitLShift(1, 1), -- Don't build software mouse cursors into the atlas (save a little texture memory)
    NoBakedLines       = bitLShift(1, 2) -- Don't build anti-aliased line textures into the atlas (save a little texture memory). SINCE 1.93.0 THIS PREVENTS ANTI-ALIASED LINES FROM WORKING AND WILL DISABLE THEM.
}

-- A cardinal direction
--- @enum ImGuiDir
ImGuiDir =
{
    None  = -1,
    Left  = 0,
    Right = 1,
    Up    = 2,
    Down  = 3,
    COUNT = 4
}

-- Identify a mouse button.
-- Those values are guaranteed to be stable and we frequently use 0/1 directly. Named enums provided for convenience.
--- @enum ImGuiMouseButton
ImGuiMouseButton =
{
    Left   = 0,
    Right  = 1,
    Middle = 2,
    COUNT  = 5
}

-- Enumeration for GetMouseCursor()
-- User code may request backend to display given cursor by calling SetMouseCursor(), which is why we have some cursors that are marked unused here
--- @enum ImGuiMouseCursor
ImGuiMouseCursor =
{
    None       = -1,
    Arrow      = 0,
    TextInput  = 1, -- When hovering over InputText, etc.
    ResizeAll  = 2, -- (Unused by Dear ImGui functions)
    ResizeNS   = 3, -- When hovering over a horizontal border
    ResizeEW   = 4, -- When hovering over a vertical border or a column
    ResizeNESW = 5, -- When hovering over the bottom-left corner of a window
    ResizeNWSE = 6, -- When hovering over the bottom-right corner of a window
    Hand       = 7, -- (Unused by Dear ImGui functions. Use for e.g. hyperlinks)
    Wait       = 8, -- When waiting for something to process/load.
    Progress   = 9, -- When waiting for something to process/load, but application is still interactive.
    NotAllowed = 10, -- When hovering something with disallowed interaction. Usually a crossed circle.
    COUNT      = 11
}

-- Coordinates of a rectangle within a texture.
-- When a texture is in ImTextureStatus.WantUpdates state, we provide a list of individual rectangles to copy to the graphics system.
-- You may use ImTextureData::Updates[] for the list, or ImTextureData::UpdateBox for a single bounding box.
--- @class ImTextureRect
--- @field x unsigned_short
--- @field y unsigned_short
--- @field w unsigned_short
--- @field h unsigned_short

--- @param x? unsigned_short
--- @param y? unsigned_short
--- @param w? unsigned_short
--- @param h? unsigned_short
--- @return ImTextureRect
function ImTextureRect(x, y, w, h) return { x = x, y = y, w = w, h = h } end

-- ImVec2: 2D vector used to store positions, sizes etc. [Compile-time configurable type]
-- [Luau] Stored as named fields {x=, y=} so the common `.x`/`.y` access is a plain table read (no metamethod call).
-- Numeric keys 1, 2 still work through the metatable, but are slower: prefer .x/.y in hot code.
--- @class ImVec2
--- @operator add(ImVec2): ImVec2
--- @operator sub(ImVec2): ImVec2
--- @operator mul(number): ImVec2
--- @operator mul(ImVec2): ImVec2
--- @operator div(number): ImVec2
--- @operator div(ImVec2): ImVec2
--- @field x number
--- @field y number
local IM_VEC2 = {}
local VEC2_KEYS = { "x", "y" }

IM_VEC2.__index = function(t, k)
    local n = VEC2_KEYS[k]
    if n then return rawget(t, n) end
end

IM_VEC2.__newindex = function(t, k, v)
    local n = VEC2_KEYS[k]
    IM_ASSERT(n ~= nil)
    rawset(t, n, v)
end

--- @param x? number
--- @param y? number
--- @return ImVec2
--- @nodiscard

function ImVec2(x, y) return setmetatable({ x = x or 0, y = y or 0 }, IM_VEC2) end


function IM_VEC2.__add(lhs, rhs) return setmetatable({ x = lhs.x + rhs.x, y = lhs.y + rhs.y }, IM_VEC2) end

function IM_VEC2.__sub(lhs, rhs) return setmetatable({ x = lhs.x - rhs.x, y = lhs.y - rhs.y }, IM_VEC2) end


function IM_VEC2.__mul(lhs, rhs)
    if type(rhs) == "number" then return setmetatable({ x = lhs.x * rhs, y = lhs.y * rhs }, IM_VEC2) end
    return setmetatable({ x = lhs.x * rhs.x, y = lhs.y * rhs.y }, IM_VEC2)
end


function IM_VEC2.__div(lhs, rhs)
    if type(rhs) == "number" then return setmetatable({ x = lhs.x / rhs, y = lhs.y / rhs }, IM_VEC2) end
    return setmetatable({ x = lhs.x / rhs.x, y = lhs.y / rhs.y }, IM_VEC2)
end

function IM_VEC2.__eq(lhs, rhs) return lhs.x == rhs.x and lhs.y == rhs.y end

function IM_VEC2:__tostring() return string.format("ImVec2(%g, %g)", self.x, self.y) end

--- @param dest ImVec2
--- @param src  ImVec2

function ImVec2_Copy(dest, src) dest.x = src.x; dest.y = src.y end

function ImVec2_CopyV(dest, src_x, src_y) dest.x = src_x; dest.y = src_y end

function ImVec2_AddVA(v, add_x, add_y) return v.x + add_x, v.y + add_y end

function ImVec2_SubVA(v, sub_x, sub_y) return v.x - sub_x, v.y - sub_y end

function ImVec2_MulVX(a, scalar) return a.x * scalar, a.y * scalar end

--- An inlined version of `ImVec2_Copy` currently for use in certain ImVector<ImVec2> `push_back`
local function ImVec2_TCopy(t, k, v) local dest = t[k]; dest.x = v.x; dest.y = v.y; end

-- ImVec4: 4D vector used to store clipping rectangles, colors etc. [Compile-time configurable type]
-- [Luau] Same layout as ImVec2: named fields x, y, z, w; numeric keys 1..4 go through the metatable.
--- @class ImVec4
--- @operator add(ImVec4): ImVec4
--- @operator sub(ImVec4): ImVec4
--- @operator mul(number): ImVec4
--- @field x number
--- @field y number
--- @field z number
--- @field w number
local IM_VEC4 = {}
local VEC4_KEYS = { "x", "y", "z", "w" }

IM_VEC4.__index = function(t, k)
    local n = VEC4_KEYS[k]
    if n then return rawget(t, n) end
end

IM_VEC4.__newindex = function(t, k, v)
    local n = VEC4_KEYS[k]
    IM_ASSERT(n ~= nil)
    rawset(t, n, v)
end

--- @return ImVec4
--- @nodiscard

function ImVec4(x, y, z, w) return setmetatable({ x = x or 0, y = y or 0, z = z or 0, w = w or 0 }, IM_VEC4) end

function IM_VEC4.__add(lhs, rhs) return ImVec4(lhs.x + rhs.x, lhs.y + rhs.y, lhs.z + rhs.z, lhs.w + rhs.w) end
function IM_VEC4.__sub(lhs, rhs) return ImVec4(lhs.x - rhs.x, lhs.y - rhs.y, lhs.z - rhs.z, lhs.w - rhs.w) end
function IM_VEC4.__mul(lhs, rhs) return ImVec4(lhs.x * rhs, lhs.y * rhs, lhs.z * rhs, lhs.w * rhs) end
function IM_VEC4.__eq(lhs, rhs) return lhs.x == rhs.x and lhs.y == rhs.y and lhs.z == rhs.z and lhs.w == rhs.w end

function IM_VEC4:__tostring() return string.format("ImVec4(%g, %g, %g, %g)", self.x, self.y, self.z, self.w) end

--- @param dest ImVec4
--- @param src  ImVec4

function ImVec4_Copy(dest, src) dest.x = src.x; dest.y = src.y; dest.z = src.z; dest.w = src.w end

-------------------------------------------------------------------------------
-- [SECTION] Helpers: Debug log, memory allocations macros, ImVector<>
-------------------------------------------------------------------------------

-- ImVector<>
--- A compact ImVector clone
--- @class ImVector<T>
--- @field Data          T[] # 1-based table
--- @field Size          int # >= 0
--- @field _Constructor  function
--- @field _CopyFunc     function
local IM_VECTOR = {}

-- Support 1-based number key indexing while keep method accessing speed
--- @param t ImVector
--- @param k string|int
--- @return any
IM_VECTOR.__index = function(t, k)
    local m = IM_VECTOR[k] -- methods first (hot path)
    if m ~= nil then return m end
    if k == "Data" then return nil end -- Data has already been discarded
    return t.Data[IM_ASSERT(k >= 1 and k <= t.Size) or k] -- if the mt access turns out nil, the k must be int index into Data
end

--- @param t ImVector
--- @param k int
--- @param v any
IM_VECTOR.__newindex = function(t, k, v)
    if k == "Data" then rawset(t, "Data", v); return; end -- set new Data. old Data is already discarded
    IM_ASSERT(k >= 1 and k <= t.Size)
    t.Data[k] = v
end

local _default_constructor = function() return nil end
local _default_copyfunc = function(t, k, v) t[k] = v end

local function _grow_capacity(v, sz) local new_capacity = (v.Capacity ~= 0) and math.floor(v.Capacity + v.Capacity / 2) or 8; return (new_capacity > sz) and new_capacity or sz; end

--- @param T?         function
--- @param COPY_FUNC? function
--- @return ImVector
--- @nodiscard
function ImVector(T, COPY_FUNC) return setmetatable({Data = nil, Size = 0, Capacity = 0, _Constructor = T or _default_constructor, _CopyFunc = COPY_FUNC or _default_copyfunc}, IM_VECTOR) end

function IM_VECTOR:push_back(value) if self.Size == self.Capacity then self:reserve(_grow_capacity(self, self.Size + 1)) end; self._CopyFunc(self.Data, self.Size + 1, value); self.Size = self.Size + 1; return value end
function IM_VECTOR:pop_back() IM_ASSERT(self.Size > 0); self.Size = self.Size - 1; end
function IM_VECTOR:push_front(value) if self.Size == 0 then self:push_back(value) else self:insert(1, value) end end
function IM_VECTOR:clear() if self.Data then self.Size = 0; self.Capacity = 0; IM_FREE(self, "Data"); self.Data = nil end end
function IM_VECTOR:clear_delete() for i = 1, self.Size do self.Data[i] = nil end self.Size = 0 end
function IM_VECTOR:empty() return self.Size == 0 end
function IM_VECTOR:back()   IM_ASSERT(self.Size > 0) return self.Data[self.Size] end
function IM_VECTOR:erase(i) IM_ASSERT(i >= 1 and i <= self.Size) local removed = (table.remove(self.Data, i)) ~= nil self.Size = self.Size - 1 return removed end
local function _iter(v, i) i = i + 1 if i <= v.Size then return i, v.Data[i] end end
function IM_VECTOR:iter() return _iter, self, 0 end
function IM_VECTOR:find_index(value) for i = 1, self.Size do if self.Data[i] == value then return i end end return nil end
function IM_VECTOR:erase_unsorted(index) IM_ASSERT(index >= 1 and index <= self.Size) local last_idx = self.Size if index ~= last_idx then self.Data[index] = self.Data[last_idx] end self.Data[last_idx] = nil self.Size = self.Size - 1 return true end
function IM_VECTOR:find_erase(value) local idx = self:find_index(value) if idx then return self:erase(idx) end return false end
function IM_VECTOR:find_erase_unsorted(value) local idx = self:find_index(value) if idx then return self:erase_unsorted(idx) end return false end

function IM_VECTOR:reserve(new_capacity)
    if new_capacity <= self.Capacity then return end
    local new_data = IM_ALLOC(self._Constructor, new_capacity)
    if self.Data then
        ImStd.memmove(new_data, 1, self.Data, 1, self.Size)
        IM_FREE(self, "Data")
    end
    self.Data = new_data
    self.Capacity = new_capacity
end

function IM_VECTOR:reserve_discard(new_capacity)
    if new_capacity <= self.Capacity then return end
    if self.Data then IM_FREE(self, "Data") end
    self.Data = IM_ALLOC(self._Constructor, new_capacity)
    self.Capacity = new_capacity
end

function IM_VECTOR:shrink(new_size) IM_ASSERT(new_size <= self.Size) self.Size = new_size end

function IM_VECTOR:resize(new_size, v)
    if new_size > self.Capacity then self:reserve(_grow_capacity(self, new_size)) end
    if v ~= nil and new_size > self.Size then
        local data = self.Data
        for n = self.Size + 1, new_size do data[n] = v end
    end
    self.Size = new_size
end

function IM_VECTOR:swap(other) self.Size, other.Size = other.Size, self.Size; self.Capacity, other.Capacity = other.Capacity, self.Capacity; self.Data, other.Data = other.Data, self.Data end
function IM_VECTOR:contains(v) for i = 1, self.Size do if self.Data[i] == v then return true end end return false end

-- NOTE: This currently does not use type-aware copy!
function IM_VECTOR:insert(pos, value) IM_ASSERT(pos >= 1 and pos <= self.Size + 1); if self.Size == self.Capacity then self:reserve(_grow_capacity(self, self.Size + 1)) end; for i = self.Size, pos, -1 do self.Data[i + 1] = self.Data[i] end self.Data[pos] = value self.Size = self.Size + 1 return value end

-- NOTE: This currently does not copy type related info!
--- @nodiscard
function IM_VECTOR:copy()
    local v = ImVector(); v:resize(self.Size)
    local dest = v.Data; local src = self.Data
    for i = 1, v.Size do dest[i] = src[i] end
    return v
end

-- Not keeping value-key records inside `ImVector`, instead just find it
--- @return int # 0-based index
function IM_VECTOR:index_from_ptr(p)
    local data = self.Data; for i = 1, self.Size do if p == data[i] then return i - 1 end end
    --- @diagnostic disable-next-line
    IM_ASSERT(false, "index_from_ptr failed!")
end

-------------------------------------------------------------------------------
-- [SECTION] Drawing API (ImDrawCmd, ImDrawIdx, ImDrawVert, ImDrawChannel, ImDrawListSplitter, ImDrawFlags, ImDrawList, ImDrawData)
-------------------------------------------------------------------------------

-- Hold a series of drawing commands. The user provides a renderer for ImDrawData which essentially contains an array of ImDrawList.

-- Typically, 1 command = 1 GPU draw call (unless command is a callback)
-- - VtxOffset: When 'io.BackendFlags & ImGuiBackendFlags.RendererHasVtxOffset' is enabled,
--   this fields allow us to render meshes larger than 64K vertices while keeping 16-bit indices.
--   Backends made for <1.71. will typically ignore the VtxOffset fields.
--- @class ImDrawCmd
--- @field ClipRect               ImVec4
--- @field TexRef                 ImTextureRef
--- @field VtxOffset              unsigned_int
--- @field IdxOffset              unsigned_int
--- @field ElemCount              unsigned_int
--- @field UserCallback           ImDrawCallback
--- @field UserCallbackData       any
--- @field UserCallbackDataSize   int
--- @field UserCallbackDataOffset int
local IM_DRAWCMD = {}
IM_DRAWCMD.__index = IM_DRAWCMD

--- @return ImDrawCmd
--- @nodiscard
function ImDrawCmd()
    return setmetatable({
        ClipRect               = ImVec4(), -- 4*4  -- Clipping rectangle (x1, y1, x2, y2). Subtract ImDrawData->DisplayPos to get clipping rectangle in "viewport" coordinates
        TexRef                 = nil, -- 16   -- Reference to a font/texture atlas (where backend called ImTextureData::SetTexID()) or to a user-provided texture ID (via e.g. ImGui.Image() calls). Both will lead to a ImTextureID value.
        VtxOffset              = 0, -- 4    -- Start offset in vertex buffer. ImGuiBackendFlags.RendererHasVtxOffset: always 0, otherwise may be >0 to support meshes larger than 64K vertices with 16-bit indices.
        IdxOffset              = 0, -- 4    -- Start offset in index buffer.
        ElemCount              = 0, -- 4    -- Number of indices (multiple of 3) to be rendered as triangles. Vertices are stored in the callee ImDrawList's vtx_buffer[] array, indices in idx_buffer[].
        UserCallback           = nil, -- 4-8  -- If != nil, call the function instead of rendering the vertices. clip_rect and texture_id will be set normally.
        UserCallbackData       = nil, -- 4-8  -- Callback user data (when UserCallback != nil). If called AddCallback() with size == 0, this is a copy of the AddCallback() argument. If called AddCallback() with size > 0, this is pointing to a buffer where data is stored.
        UserCallbackDataSize   = 0, -- 4 -- Size of callback user data when using storage, otherwise 0.
        UserCallbackDataOffset = 0 -- 4 -- [Internal] Offset of callback user data when using storage, otherwise -1.
    }, IM_DRAWCMD)
end

--- @return ImTextureID
function IM_DRAWCMD:GetTexID()
    local tex_id = (self.TexRef._TexData) and self.TexRef._TexData.TexID or self.TexRef._TexID
    if self.TexRef._TexData ~= nil then
        IM_ASSERT(tex_id ~= ImTextureID_Invalid, "ImDrawCmd is referring to ImTextureData that wasn't uploaded to graphics system. Backend must call ImTextureData::SetTexID() after handling ImTextureStatus_WantCreate request!")
    end
    return tex_id
end

-- Vertex layout
--- @class ImDrawVert
--- @field [1] ImVec2 # pos
--- @field [2] ImVec2 # uv
--- @field [3] ImU32  # col

--- @return ImDrawVert
--- @nodiscard
function ImDrawVert() return { ImVec2(), ImVec2(), nil } end

-- [Luau] ImDrawList.VtxBuffer storage: one buffer, VTX_STRIDE bytes per vertex. Vertex i (1-based) is at
-- byte (i - 1) * VTX_STRIDE: f64 pos.x, f64 pos.y, f64 uv.x, f64 uv.y, u32 col. (f64 keeps results identical to tables.)
-- Same Size/Capacity/resize/reserve/shrink/clear interface as ImVector; elements are read with ImDrawVtx_* below.
VTX_STRIDE = 36
local IM_VTXBUF = {}
IM_VTXBUF.__index = IM_VTXBUF
function ImDrawVtxBuffer() return setmetatable({ Size = 0, Capacity = 0, Buf = buffer.create(0) }, IM_VTXBUF) end
function IM_VTXBUF:reserve(n)
    if n <= self.Capacity then return end
    local nb = buffer.create(n * VTX_STRIDE)
    buffer.copy(nb, 0, self.Buf, 0, self.Size * VTX_STRIDE)
    self.Buf = nb
    self.Capacity = n
end
function IM_VTXBUF:resize(n)
    if n > self.Capacity then self:reserve(math.max(n, math.floor(self.Capacity * 1.5), 64)) end
    self.Size = n
end
function IM_VTXBUF:shrink(n) self.Size = n end
function IM_VTXBUF:clear() self.Size = 0; self.Capacity = 0; self.Buf = buffer.create(0) end

function ImDrawVtx_Pos(b, i) local o = (i - 1) * VTX_STRIDE; return buffer.readf64(b, o), buffer.readf64(b, o + 8) end
function ImDrawVtx_Col(b, i) return buffer.readu32(b, (i - 1) * VTX_STRIDE + 32) end

-- [Internal] For use by ImDrawList
--- @class ImDrawCmdHeader
--- @field ClipRect  ImVec4
--- @field TexRef    ImTextureRef
--- @field VtxOffset unsigned_int

--- @return ImDrawCmdHeader
--- @nodiscard
function ImDrawCmdHeader() return { ClipRect = ImVec4(), TexRef = nil, VtxOffset = 0 } end

-- [Internal] For use by ImDrawListSplitter
--- @class ImDrawChannel
--- @field _CmdBuffer ImVector<ImDrawCmd>
--- @field _IdxBuffer ImVector<ImDrawIdx>

--- @return ImDrawChannel
--- @nodiscard
function ImDrawChannel() return { _CmdBuffer = ImVector(), _IdxBuffer = ImVector() } end

-- Split/Merge functions are used to split the draw list into different layers which can be drawn into out of order.
-- This is used by the Columns/Tables API, so items of each column can be batched together in a same draw call.
--- @class ImDrawListSplitter
--- @field _Current  int
--- @field _Count    int
--- @field _Channels ImVector<ImDrawChannel>

--- @return ImDrawListSplitter
--- @nodiscard
MT.ImDrawListSplitter = {} -- methods in imgui_draw.lua
MT.ImDrawListSplitter.__index = MT.ImDrawListSplitter
function ImDrawListSplitter() return setmetatable({ _Current = 0, _Count = 0, _Channels = ImVector() }, MT.ImDrawListSplitter) end

-- Draw command list
-- This is the low-level list of polygons that ImGui.* functions are filling. At the end of the frame,
-- all command lists are passed to your ImGuiIO::RenderDrawListFn function for rendering.
-- Each dear imgui window contains its own ImDrawList. You can use ImGui.GetWindowDrawList() to
-- access the current window draw list and draw custom primitives.
-- You can interleave normal ImGui.* calls and adding primitives to the current draw list.
-- In single viewport mode, top-left is == GetMainViewport()->Pos (generally 0,0), bottom-right is == GetMainViewport()->Pos+Size (generally io.DisplaySize).
-- You are totally free to apply whatever transformation matrix you want to the data (depending on the use of the transformation you may want to apply it to ClipRect as well!)
-- Important: Primitives are always added to the list and not culled (culling is done at higher-level by ImGui.* functions), if you use this API a lot consider coarse culling your drawn objects.
--- @class ImDrawList
--- @field CmdBuffer         ImVector<ImDrawCmd>
--- @field IdxBuffer         ImVector<ImDrawIdx>
--- @field VtxBuffer         ImVector<ImDrawVert>
--- @field Flags             ImDrawListFlags
--- @field _VtxCurrentIdx    unsigned_int         # 1-based, generally == (VtxBuffer.Size + 1)
--- @field _Data             ImDrawListSharedData # Pointes to shared draw data
--- @field _VtxWritePtr      unsigned_int         # 1-based, points to the current writing vertex in VtxBuffer (see ImDrawVtxBuffer)
--- @field _IdxWritePtr      unsigned_int         # 1-based, points to the current writing index in IdxBuffer.Data
--- @field _Path             ImVector<ImVec2>     # current path building
--- @field _CmdHeader        ImDrawCmdHeader      # template of active commands. Fields should match those of CmdBuffer:back()
--- @field _Splitter         ImDrawListSplitter
--- @field _ClipRectStack    ImVector<ImVec4>
--- @field _TextureStack     ImVector<ImTextureRef>
--- @field _CallbacksDataBuf any
--- @field _FringeScale      float
--- @field _OwnerName        string
MT.ImDrawList = {}
MT.ImDrawList.__index = MT.ImDrawList

--- @param pos ImVec2
--- @param uv  ImVec2
--- @param col ImU32
function MT.ImDrawList:PrimWriteVtx(pos, uv, col)
    local b, o = self.VtxBuffer.Buf, (self._VtxWritePtr - 1) * VTX_STRIDE
    buffer.writef64(b, o, pos.x); buffer.writef64(b, o + 8, pos.y)
    buffer.writef64(b, o + 16, uv.x); buffer.writef64(b, o + 24, uv.y)
    buffer.writeu32(b, o + 32, col)
    self._VtxWritePtr = self._VtxWritePtr + 1
    self._VtxCurrentIdx = self._VtxCurrentIdx + 1
end

--- @param idx ImDrawIdx
function MT.ImDrawList:PrimWriteIdx(idx)
    self.IdxBuffer.Data[self._IdxWritePtr] = idx
    self._IdxWritePtr = self._IdxWritePtr + 1
end

--- @param pos ImVec2
--- @param uv  ImVec2
--- @param col ImU32
function MT.ImDrawList:PrimVtx(pos, uv, col)
    self:PrimWriteIdx(self._VtxCurrentIdx)
    self:PrimWriteVtx(pos, uv, col)
end

--- @param data? ImDrawListSharedData
--- @return ImDrawList
--- @nodiscard
function ImDrawList(data)
    --- @type ImDrawList
    local this = setmetatable({
        -- This is what you have to render
        CmdBuffer = ImVector(), -- Draw commands. Typically 1 command = 1 GPU draw call, unless the command is a callback.
        IdxBuffer = ImVector(), -- Index buffer. Each command consume ImDrawCmd::ElemCount of those
        VtxBuffer = ImDrawVtxBuffer(), -- Vertex buffer.
        Flags     = 0, -- Current flags for drawing primitives.  Alter with PushDrawFlag()/PopDrawFlags() to adjust defaults to a given scope.

        -- [Internal, used while building lists]
        _VtxCurrentIdx = 1, -- [Internal] generally == VtxBuffer.Size unless we are past 64K vertices, in which case this gets reset to 0.
        _Data          = nil, -- Pointer to shared draw data (you can use ImGui.GetDrawListSharedData() to get the one from current ImGui context)
        _VtxWritePtr   = 1, -- [Internal] point within VtxBuffer.Data after each add command (to avoid using the ImVector<> operators too much)
        _IdxWritePtr   = 1, -- [Internal] point within IdxBuffer.Data after each add command (to avoid using the ImVector<> operators too much)
        _Path          = ImVector(ImVec2, ImVec2_TCopy), -- [Internal] current path building
        _CmdHeader     = ImDrawCmdHeader(), -- [Internal] template of active commands. Fields should match those of CmdBuffer.back().
        _Splitter      = ImDrawListSplitter(), -- [Internal] for channels api (note: prefer using your own persistent instance of ImDrawListSplitter!)
        _ClipRectStack = ImVector(), -- [Internal]
        _TextureStack  = ImVector(), -- [Internal]
        _CallbacksDataBuf = nil, -- [Internal]

        _FringeScale = 0, -- [Internal] anti-alias fringe is scaled by this value, this helps to keep things sharp while zooming at vertex buffer content
        _OwnerName = nil -- Pointer to owner window's name for debugging
    }, MT.ImDrawList)

    this:_SetDrawListSharedData(data)

    return this
end

-- All draw data to render a Dear ImGui frame
-- (NB: the style and the naming convention here is a little inconsistent, we currently preserve them for backward compatibility purpose,
-- as this is one of the oldest structure exposed by the library! Basically, ImDrawList == CmdList)
--- @class ImDrawData
--- @field Valid            bool
--- @field FrameCount       int
--- @field TotalIdxCount    int
--- @field TotalVtxCount    int
--- @field CmdLists         ImVector<ImDrawList>
--- @field DisplayPos       ImVec2
--- @field DisplaySize      ImVec2
--- @field FramebufferScale ImVec2
--- @field OwnerViewport    ImGuiViewport
--- @field Textures         ImVector<ImTextureData>
MT.ImDrawData = {}
MT.ImDrawData.__index = MT.ImDrawData

--- @return ImDrawData
function ImDrawData()
    --- @type ImDrawData
    local this = setmetatable({}, MT.ImDrawData)

    this.CmdLists = ImVector() -- Array of ImDrawList* to render. The ImDrawLists are owned by ImGuiContext and only pointed to from here.
    this:Clear()

    return this
end

-------------------------------------------------------------------------------
-- [SECTION] Texture API (ImTextureFormat, ImTextureStatus, ImTextureRect, ImTextureData)
-------------------------------------------------------------------------------

-- Specs and pixel storage for a texture used by Dear ImGui.
-- This is only useful for (1) core library and (2) backends. End-user/applications do not need to care about this.
-- Renderer Backends will create a GPU-side version of this.
-- Why does we store two identifiers: TexID and BackendUserData?
-- - ImTextureID    TexID           = lower-level identifier stored in ImDrawCmd. ImDrawCmd can refer to textures not created by the backend, and for which there's no ImTextureData.
-- - void*          BackendUserData = higher-level opaque storage for backend own book-keeping. Some backends may have enough with TexID and not need both.
-- In columns below: who reads/writes each fields? 'r'=read, 'w'=write, 'core'=main library, 'backend'=renderer backend
--- @class ImTextureData
--- @field UniqueID             int
--- @field Status               ImTextureStatus
--- @field BackendUserData      any
--- @field QueueUserData        any
--- @field TexID                ImTextureID
--- @field Format               ImTextureFormat
--- @field Width                int
--- @field Height               int
--- @field BytesPerPixel        int
--- @field Pixels               unsigned_char[]
--- @field UsedRect             ImTextureRect
--- @field UpdateRect           ImTextureRect
--- @field Updates              ImVector<ImTextureRect>
--- @field UnusedFrames         int
--- @field RefCount             unsigned_short
--- @field UseColors            bool
--- @field WantDestroyNextFrame bool
MT.ImTextureData = {}
MT.ImTextureData.__index = MT.ImTextureData

--- @return ImTextureData
--- @nodiscard
function ImTextureData()
    --- @type ImTextureData
    local this = setmetatable({}, MT.ImTextureData)

    -------------------------------------------- core / backend ---------------------------------------
    this.UniqueID             = 0 -- w    -   -- [DEBUG] Sequential index to facilitate identifying a texture when debugging/printing. Unique per atlas.
    this.Status               = ImTextureStatus.Destroyed -- rw   rw  -- ImTextureStatus.OK/_WantCreate/_WantUpdates/_WantDestroy. Always use SetStatus() to modify!
    this.BackendUserData      = nil -- -    rw  -- Convenience storage for backend. Some backends may have enough with TexID.
    this.TexID                = ImTextureID_Invalid -- r    w   -- Backend-specific texture identifier. Always use SetTexID() to modify! The identifier will stored in ImDrawCmd::GetTexID() and passed to backend's RenderDrawData function.
    this.Format               = 0 -- w    r   -- ImTextureFormat.RGBA32 (default) or ImTextureFormat.Alpha8
    this.Width                = 0 -- w    r   -- Texture width
    this.Height               = 0 -- w    r   -- Texture height
    this.BytesPerPixel        = 0 -- w    r   -- 4 or 1
    this.Pixels               = nil -- w    r   -- Pointer to whole texture buffer holding 'Width*Height' pixels and 'Width*Height*BytesPerPixels' bytes.
    this.UsedRect             = ImTextureRect() -- w    r   -- Bounding box encompassing all past and queued Updates[].
    this.UpdateRect           = ImTextureRect() -- w    r   -- Bounding box encompassing all queued Updates[].
    this.Updates              = ImVector() -- w    r   -- Array of individual updates.
    this.UnusedFrames         = 0 -- w    r   -- In order to facilitate handling Status==WantDestroy in some backend: this is a count successive frames where the texture was not used. Always >0 when Status==WantDestroy.
    this.RefCount             = 0 -- w    r   -- Number of contexts using this texture. Used during backend shutdown.
    this.UseColors            = false -- w    r   -- Tell whether our texture data is known to use colors (rather than just white + alpha).
    this.WantDestroyNextFrame = false -- rw   -   -- [Internal] Queued to set ImTextureStatus.WantDestroy next frame. May still be used in the current frame.

    return this
end

--- @param x int
--- @param y int
function MT.ImTextureData:GetPixelsAt(x, y)
    return self.Pixels, (x + y * self.Width) * self.BytesPerPixel + 1
end

function MT.ImTextureData:GetPitch() return self.Width * self.BytesPerPixel end
function MT.ImTextureData:GetTexID() return self.TexID end

--- @param tex_id ImTextureID
function MT.ImTextureData:SetTexID(tex_id) self.TexID = tex_id end

--- @param status ImTextureStatus
function MT.ImTextureData:SetStatus(status) self.Status = status if (status == ImTextureStatus.Destroyed and not self.WantDestroyNextFrame and self.Pixels ~= nil) then self.Status = ImTextureStatus.WantCreate end end

-------------------------------------------------------------------------------
-- [SECTION] Texture identifiers (ImTextureID, ImTextureRef)
-------------------------------------------------------------------------------

-- ImTextureRef = higher-level identifier for a texture. Store a ImTextureID _or_ a ImTextureData*.
-- The identifier is valid even before the texture has been uploaded to the GPU/graphics system.
-- This is what gets passed to functions such as `ImGui.Image()`, `ImDrawList::AddImage()`.
-- This is what gets stored in draw commands (`ImDrawCmd`) to identify a texture during rendering.
--- @class ImTextureRef
--- @field _TexData? ImTextureData
--- @field _TexID    ImTextureID
local IM_TEXTURE_REF = {}
IM_TEXTURE_REF.__index = IM_TEXTURE_REF

--- @return ImTextureRef
--- @nodiscard
function ImTextureRef(tex_id)
    return setmetatable({
        -- Members (either are set, never both!)
        _TexData = nil, -- A texture, generally owned by a ImFontAtlas. Will convert to ImTextureID during render loop, after texture has been uploaded.
        _TexID   = tex_id or ImTextureID_Invalid -- _OR_ Low-level backend texture identifier, if already uploaded or created by user/app. Generally provided to e.g. ImGui.Image() calls.
    }, IM_TEXTURE_REF)
end

-------------------------------------------------------------------------------
-- [SECTION] Font API (ImFontConfig, ImFontGlyph, ImFontGlyphRangesBuilder, ImFontAtlasFlags, ImFontAtlas, ImFontBaked, ImFont)
-------------------------------------------------------------------------------

-- Font runtime data for a given size
-- Important: pointers to ImFontBaked are only valid for the current frame.
--- @class ImFontBaked
--- @field IndexAdvanceX        ImVector<float>       # Glyphs->AdvanceX in a directly indexable way. Note that codepoint starts from 0, so IndexAdvanceX.Data[0 + 1] holds the advanceX of glyph at codepoint 0
--- @field FallbackAdvanceX     float
--- @field Size                 float
--- @field RasterizerDensity    float
--- @field IndexLookup          ImVector<ImU16>       # Index glyphs by Unicode codepoint. use IndexLookup.Data[codepoint + 1] for codepoint. Stores 1-based index!
--- @field Glyphs               ImVector<ImFontGlyph>
--- @field FallbackGlyphIndex   int                   # Initial value = -1, then becomes 1-based index if fallback char is set
--- @field Ascent               float
--- @field Descent              float
--- @field MetricsTotalSurface  unsigned_int
--- @field WantDestroy          bool
--- @field LoadNoFallback       bool
--- @field LoadNoRenderOnLayout bool
--- @field LastUsedFrame        int
--- @field BakedId              ImGuiID
--- @field OwnerFont            ImFont
--- @field FontLoaderDatas      any
MT.ImFontBaked = {}
MT.ImFontBaked.__index = MT.ImFontBaked

--- @return ImFontBaked
--- @nodiscard
function ImFontBaked()
    --- @type ImFontBaked
    local this = setmetatable({}, MT.ImFontBaked)

    -- [Internal] Members: Hot ~20/24 bytes (for CalcTextSize)
    this.IndexAdvanceX     = ImVector() -- 12-16 -- out -- Sparse. Glyphs->AdvanceX in a directly indexable way (cache-friendly for CalcTextSize functions which only this info, and are often bottleneck in large UI).
    this.FallbackAdvanceX  = 0 -- 4     -- out -- FindGlyph(FallbackChar)->AdvanceX
    this.Size              = 0 -- 4     -- in  -- Height of characters/line, set during loading (doesn't change after loading)
    this.RasterizerDensity = 0 -- 4     -- in  -- Density this is baked at

    -- [Internal] Members: Hot ~28/36 bytes (for RenderText loop)
    this.IndexLookup        = ImVector() -- 12-16 -- out -- Sparse. Index glyphs by Unicode code-point.
    this.Glyphs             = ImVector() -- 12-16 -- out -- All glyphs.
    this.FallbackGlyphIndex = -1 -- 4     -- out -- Index of FontFallbackChar

    -- [Internal] Members: Cold
    this.Ascent               = 0 -- 4+4   -- out -- Ascent: distance from top to bottom of e.g. 'A' [0..FontSize] (unscaled)
    this.Descent              = 0
    this.MetricsTotalSurface  = 0
    this.WantDestroy          = false
    this.LoadNoFallback       = false
    this.LoadNoRenderOnLayout = false
    this.LastUsedFrame        = 0 -- 4  --     -- Record of that time this was bounds
    this.BakedId              = 0 -- 4     --     -- Unique ID for this baked storage
    this.OwnerFont            = nil -- 4-8   -- in  -- Parent font
    this.FontLoaderDatas      = nil -- 4-8   --     -- Font loader opaque storage (per baked font * sources): single contiguous buffer allocated by imgui, passed to loader.

    return this
end

-- Font runtime data and rendering
-- - ImFontAtlas automatically loads a default embedded font for you if you didn't load one manually.
-- - Since 1.92.0 a font may be rendered as any size! Therefore a font doesn't have one specific size.
-- - Use 'font->GetFontBaked(size)' to retrieve the ImFontBaked* corresponding to a given size.
-- - If you used g.Font + g.FontSize (which is frequent from the ImGui layer), you can use g.FontBaked as a shortcut, as g.FontBaked == g.Font->GetFontBaked(g.FontSize).
--- @class ImFont
--- @field LastBaked                ImFontBaked
--- @field OwnerAtlas               ImFontAtlas
--- @field Flags                    ImFontFlags
--- @field CurrentRasterizerDensity float
--- @field FontId                   ImGuiID
--- @field LegacySize               float
--- @field Sources                  ImVector<ImFontConfig>
--- @field EllipsisChar             ImWchar
--- @field FallbackChar             ImWchar
--- @field Used8kPagesMap           ImU8[]                 # 1-based table
--- @field EllipsisAutoBake         bool
--- @field RemapPairs               table<ImGuiID, any>    # LUA: No ImGuiStorage
--- @field Scale                    float
MT.ImFont = {}
MT.ImFont.__index = MT.ImFont

function MT.ImFont:IsLoaded() return self.OwnerAtlas ~= nil end
function MT.ImFont:GetDebugName() if self.Sources.Size > 0 then return self.Sources[1].Name else return "<unknown>" end end

--- @return ImFont
--- @nodiscard
function ImFont()
    --- @type ImFont
    local this = setmetatable({}, MT.ImFont)

    -- [Internal] Members: Hot ~12-20 bytes
    this.LastBaked                = nil -- 4-8   -- Cache last bound baked. NEVER USE DIRECTLY. Use GetFontBaked().
    this.OwnerAtlas               = nil -- 4-8   -- What we have been loaded into.
    this.Flags                    = 0 -- 4     -- Font flags.
    this.CurrentRasterizerDensity = 0 -- Current rasterizer density. This is a varying state of the font.
    -- [Internal] Members: Cold ~24-52 bytes
    -- Conceptually Sources[] is the list of font sources merged to create this font.
    this.FontId           = 0 -- Unique identifier for the font
    this.LegacySize       = 0 -- 4     -- in  -- Font size passed to AddFont(). Use for old code calling PushFont() expecting to use that size. (use ImGui.GetFontBaked() to get font baked at current bound size).
    this.Sources          = ImVector() -- 16    -- in  -- List of sources. Pointers within OwnerAtlas->Sources[]
    this.EllipsisChar     = 0 -- 2-4   -- out -- Character used for ellipsis rendering ('...'). If you ever want to temporarily swap this for an alternative/dummy char, make sure to clear EllipsisAutoBake.
    this.FallbackChar     = 0 -- 2-4   -- out -- Character used if a glyph isn't found (U+FFFD, '?')
    this.Used8kPagesMap   = {}
    this.EllipsisAutoBake = false -- 1     --     -- Mark when the "..." glyph (== EllipsisChar) needs to be generated by combining multiple '.'.
    this.RemapPairs       = {} -- 16    --     -- Remapping pairs when using AddRemapCodepointXXX().
    this.Scale            = 0

    return this
end

-- A font input/source (we may rename this to ImFontSource in the future)
--- @class ImFontConfig
--- @field Name                 string
--- @field FontData             table
--- @field FontDataSize         int
--- @field FontDataOwnedByAtlas bool
--- @field MergeMode            bool
--- @field PixelSnapH           bool
--- @field OversampleH          ImS8
--- @field OversampleV          ImS8
--- @field EllipsisChar         ImWchar
--- @field SizePixels           float
--- @field GlyphRanges          ImWchar[]
--- @field GlyphExcludeRanges   ImWchar[]
--- @field GlyphOffset          ImVec2
--- @field GlyphMinAdvanceX     float
--- @field GlyphMaxAdvanceX     float
--- @field GlyphExtraAdvanceX   float
--- @field FontNo               ImU32
--- @field FontLoaderFlags      unsigned_int
--- @field RasterizerMultiply   float
--- @field RasterizerDensity    float
--- @field ExtraSizeScale       float
--- @field Flags                ImFontFlags
--- @field DstFont              ImFont
--- @field FontLoader           ImFontLoader
--- @field FontLoaderData       any
local IM_FONT_CONFIG = {}
IM_FONT_CONFIG.__index = IM_FONT_CONFIG

--- @return ImFontConfig
--- @nodiscard
function ImFontConfig()
    --- @type ImFontConfig
    local this = setmetatable({}, IM_FONT_CONFIG)

    -- Data Source
    this.Name                 = nil -- <auto>   -- Name (strictly to ease debugging, hence limited size buffer)
    this.FontData             = nil -- TTF/OTF data
    this.FontDataSize         = 0 -- TTF/OTF data size
    this.FontDataOwnedByAtlas = true -- true     -- TTF/OTF data ownership taken by the owner ImFontAtlas (will delete memory itself). SINCE 1.92, THE DATA NEEDS TO PERSIST FOR WHOLE DURATION OF ATLAS.

    -- Options
    this.MergeMode          = false -- false    -- Merge into previous ImFont, so you can combine multiple inputs font into one ImFont (e.g. ASCII font + icons + Japanese glyphs). You may want to use GlyphOffset.y when merge font of different heights.
    this.PixelSnapH         = false -- false    -- Align every glyph AdvanceX to pixel boundaries. Prevents fractional font size from working correctly! Useful e.g. if you are merging a non-pixel aligned font with the default font. If enabled, OversampleH/V will default to 1.
    this.OversampleH        = 0 -- 0 (2)    -- Rasterize at higher quality for sub-pixel positioning. 0 == auto == 1 or 2 depending on size. Note the difference between 2 and 3 is minimal. You can reduce this to 1 for large glyphs save memory. Read https://github.com/nothings/stb/blob/master/tests/oversample/README.md for details.
    this.OversampleV        = 0 -- 0 (1)    -- Rasterize at higher quality for sub-pixel positioning. 0 == auto == 1. This is not really useful as we don't use sub-pixel positions on the Y axis.
    this.EllipsisChar       = 0 -- 0        -- Explicitly specify Unicode codepoint of ellipsis character. When fonts are being merged first specified ellipsis will be used.
    this.SizePixels         = 0 -- Output size in pixels for rasterizer (more or less maps to the resulting font height).
    this.GlyphRanges        = nil -- nil     -- *LEGACY* THE ARRAY DATA NEEDS TO PERSIST AS LONG AS THE FONT IS ALIVE. Pointer to a user-provided list of Unicode range (2 value per range, values are inclusive, zero-terminated list).
    this.GlyphExcludeRanges = nil -- nil     -- Pointer to a small user-provided list of Unicode ranges (2 value per range, values are inclusive, zero-terminated list). This is very close to GlyphRanges[] but designed to exclude ranges from a font source, when merging fonts with overlapping glyphs. Use "Input Glyphs Overlap Detection Tool" to find about your overlapping ranges.
    this.GlyphOffset        = ImVec2() -- 0, 0     -- Offset (in pixels) all glyphs from this font input. Absolute value for default size, other sizes will scale this value.
    this.GlyphMinAdvanceX   = 0 -- 0        -- Minimum AdvanceX for glyphs, set Min to align font icons, set both Min/Max to enforce mono-space font. Absolute value for default size, other sizes will scale this value.
    this.GlyphMaxAdvanceX   = FLT_MAX -- FLT_MAX  -- Maximum AdvanceX for glyphs
    this.GlyphExtraAdvanceX = 0 -- 0        -- Extra spacing (in pixels) between glyphs. Please contact us if you are using this. -- FIXME-NEWATLAS: Intentionally unscaled
    this.FontNo             = 0 -- 0        -- Index of font within TTF/OTF file
    this.FontLoaderFlags    = 0 -- 0        -- Settings for custom font builder. THIS IS BUILDER IMPLEMENTATION DEPENDENT. Leave as zero if unsure.
    this.RasterizerMultiply = 1.0 -- 1.0f     -- Linearly brighten (>1.0f) or darken (<1.0f) font output. Brightening small fonts may be a good workaround to make them more readable. This is a silly thing we may remove in the future.
    this.RasterizerDensity  = 1.0 -- 1.0f     -- [LEGACY: this only makes sense when ImGuiBackendFlags.RendererHasTextures is not supported] DPI scale multiplier for rasterization. Not altering other font metrics: makes it easy to swap between e.g. a 100% and a 400% fonts for a zooming display, or handle Retina screen. IMPORTANT: If you change this it is expected that you increase/decrease font scale roughly to the inverse of this, otherwise quality may look lowered.
    this.ExtraSizeScale     = 1.0 -- 1.0f     -- Extra rasterizer scale over SizePixels.

    -- [Internal]
    this.Flags          = 0 -- Font flags (don't use just yet, will be exposed in upcoming 1.92.X updates)
    this.DstFont        = nil -- Target font (as we merging fonts, multiple ImFontConfig may target the same font)
    this.FontLoader     = nil -- Custom font backend for this source (default source is the one stored in ImFontAtlas)
    this.FontLoaderData = nil -- Font loader opaque storage (per font config)

    return this
end

-- Load and rasterize multiple TTF/OTF fonts into a same texture. The font atlas will build a single texture holding:
--  - One or more fonts.
--  - Custom graphics data needed to render the shapes needed by Dear ImGui.
--  - Mouse cursor shapes for software cursor rendering (unless setting 'Flags |= ImFontAtlasFlags.NoMouseCursors' in the font atlas).
--  - If you don't call any AddFont*** functions, the default font embedded in the code will be loaded for you.
-- It is the rendering backend responsibility to upload texture into your graphics API:
--  - ImGui_ImplXXXX_RenderDrawData() functions generally iterate platform_io->Textures[] to create/update/destroy each ImTextureData instance.
--  - Backend then set ImTextureData's TexID and BackendUserData.
--  - Texture id are passed back to you during rendering to identify the texture. Read FAQ entry about ImTextureID/ImTextureRef for more details.
--- @class ImFontAtlas
--- @field Flags               ImFontAtlasFlags
--- @field TexDesiredFormat    ImTextureFormat
--- @field TexGlyphPadding     int
--- @field TexMinWidth         int
--- @field TexMinHeight        int
--- @field TexMaxWidth         int
--- @field TexMaxHeight        int
--- @field TexRef              ImTextureRef
--- @field TexData             ImTextureData
--- @field TexList             ImVector<ImTextureData>
--- @field Locked              bool
--- @field RendererHasTextures bool
--- @field TexPixelsUseColors  bool
--- @field TexUvScale          ImVec2
--- @field TexUvWhitePixel     ImVec2
--- @field Fonts               ImVector<ImFont>
--- @field Sources             ImVector<ImFontConfig>
--- @field TexUvLines          ImVec4[]                       # 0-based table
--- @field TexNextUniqueID     int
--- @field FontNextUniqueID    int
--- @field DrawListSharedDatas ImVector<ImDrawListSharedData>
--- @field Builder             ImFontAtlasBuilder
--- @field FontLoader          ImFontLoader
--- @field FontLoaderName      string
--- @field FontLoaderData      any
--- @field FontLoaderFlags     unsigned_int
--- @field RefCount            int
--- @field OwnerContext        ImGuiContext
MT.ImFontAtlas = {}
MT.ImFontAtlas.__index = MT.ImFontAtlas

--- @return ImFontAtlas
--- @nodiscard
function ImFontAtlas()
    --- @type ImFontAtlas
    local this = setmetatable({}, MT.ImFontAtlas)

    -- Input
    this.Flags               = 0 -- Build flags (see ImFontAtlasFlags_)
    this.TexDesiredFormat    = ImTextureFormat.RGBA32 -- Desired texture format (default to ImTextureFormat.RGBA32 but may be changed to ImTextureFormat.Alpha8).
    this.TexGlyphPadding     = 1 -- FIXME: Should be called "TexPackPadding". Padding between glyphs within texture in pixels. Defaults to 1. If your rendering method never relies on bilinear filtering you may set this to 0.
    this.TexMinWidth         = 512 -- Minimum desired texture width. Must be a power of two. Default to 512.
    this.TexMinHeight        = 128 -- Minimum desired texture height. Must be a power of two. Default to 128.
    this.TexMaxWidth         = 8192 -- Maximum desired texture width. Must be a power of two. Default to 8192.
    this.TexMaxHeight        = 8192 -- Maximum desired texture height. Must be a power of two. Default to 8192.

    this.TexRef              = ImTextureRef()

    this.TexData             = nil -- Latest texture.

    -- [Internal]
    this.TexList             = ImVector() -- Texture list (most often TexList.Size == 1). TexData is always == TexList.back(). DO NOT USE DIRECTLY, USE GetDrawData().Textures[]/GetPlatformIO().Textures[] instead!
    this.Locked              = false -- Marked as locked during ImGui.NewFrame()..EndFrame() scope if TexUpdates are not supported. Any attempt to modify the atlas will assert.
    this.RendererHasTextures = false -- Copy of (BackendFlags & ImGuiBackendFlags.RendererHasTextures) from supporting context.
    this.TexPixelsUseColors  = nil -- Tell whether our texture data is known to use colors (rather than just alpha channel), in order to help backend select a format or conversion process.
    this.TexUvScale          = nil -- = (1.0f/TexData->TexWidth, 1.0f/TexData->TexHeight). May change as new texture gets created.
    this.TexUvWhitePixel     = nil -- Texture coordinates to a white pixel. May change as new texture gets created.
    this.Fonts               = ImVector() -- Hold all the fonts returned by AddFont*. Fonts[0] is the default font upon calling ImGui.NewFrame(), use ImGui.PushFont()/PopFont() to change the current font.
    this.Sources             = ImVector() -- Source/configuration data
    this.TexUvLines          = {}
    this.TexNextUniqueID     = 1 -- Next value to be stored in TexData->UniqueID
    this.FontNextUniqueID    = 1 -- Next value to be stored in ImFont->FontID
    this.DrawListSharedDatas = ImVector() -- List of users for this atlas. Typically one per Dear ImGui context.
    this.Builder             = nil -- Opaque interface to our data that doesn't need to be public and may be discarded when rebuilding.
    this.FontLoader          = nil -- Font loader opaque interface (default to use FreeType when IMGUI_ENABLE_FREETYPE is defined, otherwise default to use stb_truetype). Use SetFontLoader() to change this at runtime.
    this.FontLoaderName      = nil -- Font loader name (for display e.g. in About box) == FontLoader->Name
    this.FontLoaderData      = nil -- Font backend opaque storage
    this.FontLoaderFlags     = nil -- Shared flags (for all fonts) for font loader. THIS IS BUILD IMPLEMENTATION DEPENDENT (e.g. Per-font override is also available in ImFontConfig).
    this.RefCount            = 0 -- Number of contexts using this atlas
    this.OwnerContext        = nil -- Context which own the atlas will be in charge of updating and destroying it.

    return this
end

-- Output of ImFontAtlas::GetCustomRect() when using custom rectangles.
-- Those values may not be cached/stored as they are only valid for the current value of atlas->TexRef
-- (this is in theory derived from ImTextureRect but we use separate structures for reasons)
--- @class ImFontAtlasRect
--- @field x   unsigned_short
--- @field y   unsigned_short
--- @field w   unsigned_short
--- @field h   unsigned_short
--- @field uv0 ImVec2
--- @field uv1 ImVec2

-- An opaque identifier to a rectangle in the atlas. -1 when invalid.
-- The rectangle may move and UV may be invalidated, use GetCustomRect() to retrieve it.
--- @alias ImFontAtlasRectId int

ImFontAtlasRectId_Invalid = -1

--- @return ImFontAtlasRect
--- @nodiscard
function ImFontAtlasRect()
    return {
        x = nil, y = nil, -- Position (in current texture)
        w = nil, h = nil, -- Size
        uv0 = ImVec2(), -- UV coordinates (in current texture)
        uv1 = ImVec2()
    }
end

-- Hold rendering data for one glyph.
--- @class ImFontGlyph
--- @field Colored   boolean
--- @field Visible   boolean
--- @field SourceIdx unsigned_int
--- @field Codepoint unsigned_int
--- @field AdvanceX  float
--- @field X0        float
--- @field Y0        float
--- @field X1        float
--- @field Y1        float
--- @field U0        float
--- @field V0        float
--- @field U1        float
--- @field V1        float
--- @field PackId    int

--- @return ImFontGlyph
--- @nodiscard
function ImFontGlyph()
    return {
        Colored   = false,
        Visible   = false,
        SourceIdx = 0,
        Codepoint = 0,
        AdvanceX  = 0, -- Horizontal distance to advance cursor/layout position.

        X0 = 0, Y0 = 0, X1 = 0, Y1 = 0, -- Glyph corners. Offsets from current cursor/layout position.
        U0 = 0, V0 = 0, U1 = 0, V1 = 0, -- Texture coordinates for the current value of ImFontAtlas->TexRef. Cached equivalent of calling GetCustomRect() with PackId.

        PackId = -1 -- [Internal] ImFontAtlasRectId value (FIXME: Cold data, could be moved elsewhere?)
    }
end

-------------------------------------------------------------------------------
-- [SECTION] ImGuiIO
-------------------------------------------------------------------------------

-- Communicate most settings and inputs/outputs to Dear ImGui using this structure.
-- Access via ImGui.GetIO(). Read 'Programmer guide' section in .cpp file for general usage.
-- It is generally expected that:
-- - initialization: backends and user code writes to ImGuiIO.
-- - main loop: backends writes to ImGuiIO, user code and imgui code reads from ImGuiIO.
-------------------------------------------------------------------------------
-- Also see ImGui.GetPlatformIO() and ImGuiPlatformIO struct for OS/platform related functions: clipboard, IME etc.
-------------------------------------------------------------------------------

-- [Internal] Storage used by IsKeyDown(), IsKeyPressed() etc functions.
-- If prior to 1.87 you used io.KeysDownDuration[] (which was marked as internal), you should use GetKeyData(key)->DownDuration and *NOT* io.KeysData[key]->DownDuration.
--- @class ImGuiKeyData
--- @field Down             bool
--- @field DownDuration     float
--- @field DownDurationPrev float
--- @field AnalogValue      float

--- @return ImGuiKeyData
--- @nodiscard
function ImGuiKeyData() return { Down = false, DownDuration = 0.0, DownDurationPrev = 0.0, AnalogValue = 0.0 } end

-- Configuration flags stored in io.ConfigFlags. Set by user/application.
-- Note that nowadays most of our configuration options are in other ImGuiIO fields, e.g. io.ConfigWindowsMoveFromTitleBarOnly.
--- @enum ImGuiConfigFlags
ImGuiConfigFlags = {
    None                = 0,
    NavEnableKeyboard   = bitLShift(1, 0),
    NavEnableGamepad    = bitLShift(1, 1),
    NoMouse             = bitLShift(1, 4),
    NoMouseCursorChange = bitLShift(1, 5),
    NoKeyboard          = bitLShift(1, 6),
    DockingEnable       = bitLShift(1, 7),
    ViewportsEnable     = bitLShift(1, 10),
    IsSRGB              = bitLShift(1, 20),
    IsTouchScreen       = bitLShift(1, 21)
}

--- @class ImGuiIO
MT.ImGuiIO = {}
MT.ImGuiIO.__index = MT.ImGuiIO

--- @return ImGuiIO
function ImGuiIO()
    local this = {
        Ctx = nil, -- Parent UI context (needs to be set explicitly by parent).

        KeyCtrl  = false, -- Keyboard modifier down: Ctrl (non-macOS), Cmd (macOS)
        KeyShift = false, -- Keyboard modifier down: Shift
        KeyAlt   = false, -- Keyboard modifier down: Alt
        KeySuper = false, -- Keyboard modifier down: Windows/Super (non-macOS), Ctrl (macOS)

        -- Other state maintained from data above + IO function calls
        KeyMods  = nil, -- Key mods flags (any of ImGuiMod_Ctrl/ImGuiMod_Shift/ImGuiMod_Alt/ImGuiMod_Super flags, same as io.KeyCtrl/KeyShift/KeyAlt/KeySuper but merged into flags). Read-only, updated by NewFrame()

        BackendFlags = ImGuiBackendFlags.None, -- = 0              -- See ImGuiBackendFlags_ enum. Set by backend (imgui_impl_xxx files or custom backend) to communicate features supported by the backend.
        ConfigFlags  = ImGuiConfigFlags.None, -- = 0              -- See ImGuiConfigFlags_ enum. Set by user/application. Keyboard/Gamepad navigation options, etc.
        DisplaySize = ImVec2(-1.0, -1.0), -- <unset>          -- Main display size, in pixels (== GetMainViewport()->Size). May change every frame.

        DeltaTime = 1.0 / 60.0, -- = 1.0f/60.0f     -- Time elapsed since last frame, in seconds. May change every frame.

        DisplayFramebufferScale = ImVec2(1.0, 1.0), -- = (1, 1)         -- Main display density. For retina display where window coordinates are different from framebuffer coordinates. This will affect font density + will end up in ImDrawData::FramebufferScale.

        -- Main Input State
        -- (this block used to be written by backend, since 1.87 it is best to NOT write to those directly, call the AddXXX functions above instead)
        -- (reading from those variables is fair game, as they are extremely unlikely to be moving anywhere)
        MousePos = ImVec2(), -- Mouse position, in pixels. Set to ImVec2(-FLT_MAX, -FLT_MAX) if mouse is unavailable (on another screen, etc.)
        MousePosPrev = ImVec2(), -- Previous mouse position (note that MouseDelta is not necessary == MousePos-MousePosPrev, in case either position is invalid)

        WantSetMousePos = false, -- MousePos has been altered, backend should reposition mouse on next frame. Rarely used! Set only when io.ConfigNavMoveSetMousePos is enabled.

        MouseDelta = ImVec2(), -- Mouse delta. Note that this is zero if either current or previous position are invalid (-FLT_MAX,-FLT_MAX), so a disappearing/reappearing mouse won't have a huge delta.

        MouseDown = {[0] = false, [1] = false, [2] = false}, -- Mouse buttons: 0=left, 1=right, 2=middle + extras (ImGuiMouseButton.COUNT == 5). Dear ImGui mostly uses left and right buttons. Other buttons allow us to track if the mouse is being used by your application + available to user as a convenience via IsMouse** API.

        MouseWheel = 0, -- Mouse wheel Vertical: 1 unit scrolls about 5 lines text. >0 scrolls Up, <0 scrolls Down. Hold Shift to turn vertical scroll into horizontal scroll.
        MouseWheelH = 0, -- Mouse wheel Horizontal. >0 scrolls Left, <0 scrolls Right. Most users don't have a mouse with a horizontal wheel, may not be filled by all backends.

        MouseCtrlLeftAsRightClick = false, -- (OSX) Set to true when the current click was a Ctrl+Click that spawned a simulated right click

        MouseWheelRequestAxisSwap = false, -- On a non-Mac system, holding Shift requests WheelY to perform the equivalent of a WheelX event. On a Mac system this is already enforced by the system.

        ConfigColorEditFlags = ImGuiColorEditFlags.DefaultOptions_, -- = <defaults>     -- Current settings for ColorEdit/ColorPicker widgets. Must have one bit of ImGuiColorEditFlags.DisplayMask_, one bit of ImGuiColorEditFlags.DataTypeMask_, one bit of ImGuiColorEditFlags.PickerMask_, one bit of ImGuiColorEditFlags.InputMask_. Defaults to ImGuiColorEditFlags.DefaultOptions_. May be further edited by users, unless you also set ImGuiColorEditFlags.NoOptions.

        -- Widget options
        ConfigMacOSXBehaviors = false, -- Swap Cmd<>Ctrl keys + OS X style text editing cursor movement using Alt instead of Ctrl, Shortcuts using Cmd/Super instead of Ctrl, Line/Text Start and End using Cmd+Arrows instead of Home/End, Double click selects by word instead of selecting whole text, Multi-selection in lists uses Cmd/Super instead of Ctrl.
        ConfigNavCursorVisibleAuto = true, -- = true           -- Using directional navigation key makes the cursor visible. Mouse click hides the cursor.
        ConfigNavCursorVisibleAlways = false, -- = false          -- Navigation cursor is always visible.
        ConfigInputTrickleEventQueue = true, -- = true           -- Enable input queue trickling: some types of events submitted during the same frame (e.g. button down + up) will be spread over multiple frames, improving interactions with low framerates.
        ConfigWindowsResizeFromEdges = true, -- = true           -- Enable resizing of windows from their edges and from the lower-left corner. This requires ImGuiBackendFlags.HasMouseCursors for better mouse cursor feedback. (This used to be a per-window ImGuiWindowFlags.ResizeFromAnySide flag)

        ConfigDebugIniSettings = false, -- = false          -- Save .ini data with extra comments (particularly helpful for Docking, but makes saving slower)
        ConfigWindowsCopyContentsWithCtrlC = false, -- = false      -- [EXPERIMENTAL] Ctrl+C copy the contents of focused window into the clipboard. Experimental because: (1) has known issues with nested Begin/End pairs (2) text output quality varies (3) text output is in submission order rather than spatial order.
        ConfigWindowsMoveFromTitleBarOnly = false, -- = false      -- Enable allowing to move windows only when clicking on their title bar. Does not apply to windows without a title bar.
        -- Options to configure Error Handling and how we handle recoverable errors [EXPERIMENTAL]
        -- - Error recovery is provided as a way to facilitate:
        --    - Recovery after a programming error (native code or scripting language - the latter tends to facilitate iterating on code while running).
        --    - Recovery after running an exception handler or any error processing which may skip code after an error has been detected.
        -- - Error recovery is not perfect nor guaranteed! It is a feature to ease development.
        --   You not are not supposed to rely on it in the course of a normal application run.
        -- - Functions that support error recovery are using IM_ASSERT_USER_ERROR() instead of IM_ASSERT().
        -- - By design, we do NOT allow error recovery to be 100% silent. One of the three options needs to be checked!
        -- - Always ensure that on programmers seats you have at minimum Asserts or Tooltips enabled when making direct imgui API calls!
        --   Otherwise it would severely hinder your ability to catch and correct mistakes!
        -- Read https://github.com/ocornut/imgui/wiki/Error-Handling for details.
        -- - Programmer seats: keep asserts (default), or disable asserts and keep error tooltips (new and nice!)
        -- - Non-programmer seats: maybe disable asserts, but make sure errors are resurfaced (tooltips, visible log entries, use callback etc.)
        -- - Recovery after error/exception: record stack sizes with ErrorRecoveryStoreState(), disable assert, set log callback (to e.g. trigger high-level breakpoint), recover with ErrorRecoveryTryToRecoverState(), restore settings.
        ConfigErrorRecovery = true, -- = true       -- Enable error recovery support. Some errors won't be detected and lead to direct crashes if recovery is disabled.
        ConfigErrorRecoveryEnableAssert = true, -- = true       -- Enable asserts on recoverable error. By default call IM_ASSERT() when returning from a failing IM_ASSERT_USER_ERROR()
        ConfigErrorRecoveryEnableDebugLog = true, -- = true       -- Enable debug log output on recoverable errors.
        ConfigErrorRecoveryEnableTooltip = true, -- = true       -- Enable tooltip on recoverable errors. The tooltip include a way to enable asserts if they were disabled.
        -- Tools to detect code submitting items with conflicting/duplicate IDs
        -- - Code should use PushID()/PopID() in loops, or append "##xx" to same-label identifiers.
        -- - Empty label e.g. Button("") == same ID as parent widget/node. Use Button("##xx") instead!
        -- - See FAQ https://github.com/ocornut/imgui/blob/master/docs/FAQ.md#q-about-the-id-stack-system
        ConfigDebugHighlightIdConflicts = false, -- Highlight and show an error message popup when multiple items have conflicting identifiers.
        ConfigDebugHighlightIdConflictsShowItemPicker = true, -- =true -- Show "Item Picker" button in aforementioned popup.

        IniFilename = "imgui.ini", -- Roblox: no disk access, only used as a flag (nil disables .ini handling)
        IniSavingRate = 5.0, -- = 5.0f           -- Minimum time between saving positions/sizes to .ini file, in seconds.
        LogFilename = "imgui_log.txt", -- = "imgui_log.txt"-- Path to .log file (default parameter to ImGui.LogToFile when no file is specified).
        WantSaveIniSettings = false, -- When manual .ini load/save is active (io.IniFilename == nil), this will be set to notify your application that you can call SaveIniSettingsToMemory() and save yourself. Important: clear io.WantSaveIniSettings yourself after saving!

        -- Docking options (when ImGuiConfigFlags.DockingEnable is set)
        ConfigDockingNoSplit = false, -- = false          -- Simplified docking mode: disable window splitting, so docking is limited to merging multiple windows together into tab-bars.
        ConfigDockingNoDockingOver = false, -- = false          -- Simplified docking mode: disable window merging into a same tab-bar, so docking is limited to splitting windows.
        ConfigDockingWithShift = false, -- = false          -- Enable docking with holding Shift key (reduce visual noise, allows dropping in wider space)
        ConfigDockingAlwaysTabBar = false, -- = false          -- [BETA] [FIXME: This currently creates regression with auto-sizing and general overhead] Make every single floating window display within a docking node.
        ConfigDockingTransparentPayload = false, -- = false          -- [BETA] Make window or viewport transparent when docking and only display docking boxes on the target viewport. Useful if rendering of multiple viewport cannot be synced. Best used with ConfigViewportsNoAutoMerge.
        -- Viewport options (when ImGuiConfigFlags.ViewportsEnable is set)
        -- (sorry for the amount of "NoXXXX" flags, which may be harder to reason about! may rework someday)
        ConfigViewportsNoAutoMerge = false, -- = false;         -- Set to make all floating imgui windows always create their own viewport. Otherwise, they are merged into the main host viewports when overlapping it. May also set ImGuiViewportFlags.NoAutoMerge on individual viewport.
        ConfigViewportsNoTaskBarIcon = false, -- = false          -- Disable default OS task bar icon flag for secondary viewports. When a viewport doesn't want a task bar icon, ImGuiViewportFlags.NoTaskBarIcon will be set on it.
        ConfigViewportsNoDecoration = true, -- = true           -- Disable default OS window decoration flag for secondary viewports. When a viewport doesn't want window decorations, ImGuiViewportFlags.NoDecoration will be set on it. Enabling decoration can create subsequent issues at OS levels (e.g. minimum window size).
        ConfigViewportsNoDefaultParent = true, -- = true           -- Disable setting OS window parent to main viewport by default. The platform backend is expected to honor `viewport->ParentViewportID` to setup a parent/child relationship between the OS windows (supported if ImGuiBackendFlags.HasParentViewport is set). When parented: child windows always appear in front of their parent. Set to false if you want viewports to automatically be parent of main viewport, otherwise all viewports will be top-level OS windows. Parent/child relationship may be set on a per-window basis using ImGuiWindowClass.
        ConfigViewportsPlatformFocusSetsImGuiFocus = true, -- = true -- When a platform window is focused (e.g. using Alt+Tab, clicking Platform Title Bar), apply corresponding focus on imgui windows (may clear focus/active id from imgui windows location in other platform windows). In principle this is better enabled but we provide an opt-out, because some Linux window managers tend to eagerly focus windows (e.g. on mouse hover, or even a simple window pos/size change).

        ConfigMemoryCompactTimer = 60.0, -- = 60.0f          -- Timer (in seconds) to free transient windows/tables memory buffers when unused. Set to -1.0f to disable.

        -- Miscellaneous options
        -- (you can visualize and interact with all options in 'Demo->Configuration')
        MouseDrawCursor = false, -- = false          -- Request ImGui to draw a mouse cursor for you (if you are on a platform without a mouse cursor). Cannot be easily renamed to 'io.ConfigXXX' because this is frequently used by backend implementations.

        MouseClicked          = {[0] = false, [1] = false, [2] = false}, -- Mouse button went from !Down to Down (same as MouseClickedCount[x] != 0)
        MouseReleased         = {[0] = false, [1] = false, [2] = false}, -- Mouse button went from Down to !Down
        MouseClickedCount     = {[0] =  0, [1] =  0, [2] =  0}, -- == 0 (not clicked), == 1 (same as MouseClicked[]), == 2 (double-clicked), == 3 (triple-clicked) etc. when going from !Down to Down
        MouseClickedLastCount = {[0] =  0, [1] =  0, [2] =  0}, -- Count successive number of clicks. Stays valid after mouse release. Reset after another click is done.
        MouseDownDuration     = {[0] = -1, [1] = -1, [2] = -1}, -- Duration the mouse button has been down (0.0f == just clicked)
        MouseDownDurationPrev = {[0] = -1, [1] = -1, [2] = -1}, -- Previous time the mouse button has been down

        MouseDragMaxDistanceAbs = {[0] = ImVec2(), [1] = ImVec2(), [2] = ImVec2()}, -- Maximum distance, absolute, on each axis, of how much mouse has traveled from the clicking point
        MouseDragMaxDistanceSqr = {[0] = 0, [1] = 0, [2] = 0}, -- Squared maximum distance of how much mouse has traveled from the clicking point (used for moving thresholds)

        MouseDownOwned    = {[0] = nil, [1] = nil, [2] = nil}, -- Track if button was clicked inside a dear imgui window or over void blocked by a popup. We don't request mouse capture from the application if click started outside ImGui bounds.
        MouseDownOwnedUnlessPopupClose = {[0] = nil, [1] = nil, [2] = nil}, -- Track if button was clicked inside a dear imgui window.
        MouseClickedTime  = {[0] = 0, [1] = 0, [2] = 0}, -- Time of last click (used to figure out double-click)
        MouseReleasedTime = {[0] = 0, [1] = 0, [2] = 0}, -- Time of last released (rarely used! but useful to handle delayed single-click when trying to disambiguate them from double-click).
        MouseClickedPos   = {[0] = ImVec2(), [1] = ImVec2(), [2] = ImVec2()}, -- Position at time of clicking

        MouseDoubleClicked = {[0] = false, [1] = false, [2] = false}, -- Has mouse button been double-clicked? (same as MouseClickedCount[x] == 2)

        -- Inputs Behaviors
        -- (other variables, ones which are expected to be tweaked within UI code, are exposed in ImGuiStyle)
        MouseDoubleClickTime    = 0.30, -- = 0.30f          -- Time for consecutive clicks to account as a double-click, in seconds.
        MouseSingleClickDelay   = 0.50, -- Time for a delayed click when using GetItemClickedCountWithSingleClickDelay() or IsMouseReleasedWithDelay(), in seconds. Must be > io.MouseDoubleClickTime.
        MouseDoubleClickMaxDist = 6.0, -- = 6.0f           -- Distance threshold to stay in to validate a double-click or multiple clicks, in pixels.
        MouseDragThreshold      = 6.0, -- = 6.0f           -- Distance threshold before considering we are dragging.
        KeyRepeatDelay          = 0.275, -- = 0.275f         -- When holding a key/button, time before it starts repeating, in seconds (for buttons in Repeat mode, etc.).
        KeyRepeatRate           = 0.050, -- = 0.050f         -- When holding a key/button, rate at which it repeats, in seconds.

        KeysData = {}, -- size = ImGuiKey.NamedKey_COUNT

        WantCaptureMouse    = nil, -- Set when Dear ImGui will use mouse inputs, in this case do not dispatch them to your main game/application (either way, always pass on mouse inputs to imgui). (e.g. unclicked mouse is hovering over an imgui window, widget is active, mouse was clicked over an imgui window, etc.).
        WantCaptureKeyboard = nil, -- Set when Dear ImGui will use keyboard inputs, in this case do not dispatch them to your main game/application (either way, always pass keyboard inputs to imgui). (e.g. InputText active, or an imgui window is focused and navigation is enabled, etc.).
        WantTextInput       = nil, -- Mobile/console: when set, you may display an on-screen keyboard. This is set by Dear ImGui when it wants textual keyboard input to happen (e.g. when a InputText widget is active).

        Framerate = 0, -- Estimate of application framerate (rolling average over 60 frames, based on io.DeltaTime), in frame per second. Solely for convenience. Slow applications may not want to use a moving average or may want to reset underlying buffers occasionally.
        MetricsRenderVertices = 0, MetricsRenderIndices = 0, MetricsRenderWindows = 0, MetricsActiveWindows = 0,

        NavActive = false, -- Keyboard/Gamepad navigation is currently allowed (will handle ImGuiKey.NavXXX events) = a window is focused and it doesn't use the ImGuiWindowFlags.NoNavInputs flag.
        NavVisible = false, -- Keyboard/Gamepad navigation highlight is visible and allowed (will handle ImGuiKey.NavXXX events).

        MetricsRenderWindows = 0, -- Number of visible windows

        -- Font system
        Fonts = nil, -- <auto>           -- Font atlas: load, rasterize and pack one or more fonts into a single texture.
        FontDefault = nil, -- = nil           -- Font to use on NewFrame(). Use nil to uses Fonts->Fonts[0].

        BackendPlatformUserData = nil, -- = nil           -- User data for platform backend
        BackendRendererUserData = nil, -- = nil           -- User data for renderer backend

        InputQueueCharacters = ImVector(), -- Queue of _characters_ input (obtained by platform backend). Fill using AddInputCharacter() helper.

        AppAcceptingEvents = true, -- Only modify via SetAppAcceptingEvents()
        InputQueueSurrogate = 0 -- For AddInputCharacterUTF16()
    }

    for i = 0, ImGuiKey.NamedKey_COUNT - 1 do
        this.KeysData[i] = ImGuiKeyData()
    end

    return setmetatable(this, MT.ImGuiIO)
end

-- (Optional) Support for IME (Input Method Editor) via the platform_io.Platform_SetImeDataFn() function. Handler is called during EndFrame().
--- @class ImGuiPlatformImeData
--- @field WantVisible     bool
--- @field WantTextInput   bool
--- @field InputPos        ImVec2
--- @field InputLineHeight float
--- @field ViewportId      ImGuiID

--- @return ImGuiPlatformImeData
--- @nodiscard
function ImGuiPlatformImeData()
    return {
        WantVisible     = false, -- A widget wants the IME to be visible.
        WantTextInput   = false, -- A widget wants text input, not necessarily IME to be visible. This is automatically set to the upcoming value of io.WantTextInput.
        InputPos        = ImVec2(), -- Position of input cursor (for IME).
        InputLineHeight = 0.0, -- Line height (for IME).
        ViewportId      = 0 -- ID of platform window/viewport.
    }
end

--- @param dest ImGuiPlatformImeData
--- @param src  ImGuiPlatformImeData
function ImGuiPlatformImeData_Copy(dest, src)
    dest.WantVisible = src.WantVisible
    dest.WantTextInput = src.WantTextInput
    ImVec2_Copy(dest.InputPos, src.InputPos)
    dest.InputLineHeight = src.InputLineHeight
    dest.ViewportId = src.ViewportId
end

--- @param data1 ImGuiPlatformImeData
--- @param data2 ImGuiPlatformImeData
function ImGuiPlatformImeData_Compare(data1, data2)
    if data1.WantVisible ~= data2.WantVisible or
        data1.WantTextInput ~= data2.WantTextInput or
        data1.InputPos ~= data2.InputPos or
        data1.InputLineHeight ~= data2.InputLineHeight or
        data1.ViewportId ~= data2.ViewportId then
        return false
    end

    return true
end

-------------------------------------------------------------------------------
-- [SECTION] Viewports
-------------------------------------------------------------------------------

-- Flags stored in ImGuiViewport::Flags, giving indications to the platform backends.
--- @enum ImGuiViewportFlags
ImGuiViewportFlags = {
    None                = 0,
    IsPlatformWindow    = bitLShift(1, 0), -- Represent a Platform Window
    IsPlatformMonitor   = bitLShift(1, 1), -- Represent a Platform Monitor (unused yet)
    OwnedByApp          = bitLShift(1, 2), -- Platform Window: Is created/managed by the user application? (rather than our backend)
    NoDecoration        = bitLShift(1, 3), -- Platform Window: Disable platform decorations: title bar, borders, etc. (generally set all windows, but if ImGuiConfigFlags.ViewportsDecoration is set we only set this on popups/tooltips)
    NoTaskBarIcon       = bitLShift(1, 4), -- Platform Window: Disable platform task bar icon (generally set on popups/tooltips, or all windows if ImGuiConfigFlags.ViewportsNoTaskBarIcon is set)
    NoFocusOnAppearing  = bitLShift(1, 5), -- Platform Window: Don't take focus when created.
    NoFocusOnClick      = bitLShift(1, 6), -- Platform Window: Don't take focus when clicked on.
    NoInputs            = bitLShift(1, 7), -- Platform Window: Make mouse pass through so we can drag this window while peaking behind it.
    NoRendererClear     = bitLShift(1, 8), -- Platform Window: Renderer doesn't need to clear the framebuffer ahead (because we will fill it entirely).
    NoAutoMerge         = bitLShift(1, 9), -- Platform Window: Avoid merging this window into another host window. This can only be set via ImGuiWindowClass viewport flags override (because we need to now ahead if we are going to create a viewport in the first place!).
    TopMost             = bitLShift(1, 10), -- Platform Window: Display on top (for tooltips only).
    CanHostOtherWindows = bitLShift(1, 11), -- Viewport can host multiple imgui windows (secondary viewports are associated to a single window). -- FIXME: In practice there's still probably code making the assumption that this is always and only on the MainViewport. Will fix once we add support for "no main viewport".

    -- Output status flags (from Platform)
    IsMinimized = bitLShift(1, 12), -- Platform Window: Window is minimized, can skip render. When minimized we tend to avoid using the viewport pos/size for clipping window or testing if they are contained in the viewport.
    IsFocused   = bitLShift(1, 13) -- Platform Window: Window is focused (last call to Platform_GetWindowFocus() returned true)
}

-- - Currently represents the Platform Window created by the application which is hosting our Dear ImGui windows.
-- - With multi-viewport enabled, we extend this concept to have multiple active viewports.
-- - In the future we will extend this concept further to also represent Platform Monitor and support a "no main platform window" operation mode.
-- - About Main Area vs Work Area:
--   - Main Area = entire viewport.
--   - Work Area = entire viewport minus sections used by main menu bars (for platform windows), or by task bar (for platform monitor).
--   - Windows are generally trying to stay within the Work Area of their host viewport.
--- @class ImGuiViewport
--- @field ID                    ImGuiID
--- @field Flags                 ImGuiViewportFlags
--- @field Pos                   ImVec2
--- @field Size                  ImVec2
--- @field FramebufferScale      ImVec2
--- @field WorkPos               ImVec2
--- @field WorkSize              ImVec2
--- @field DpiScale              float
--- @field ParentViewportId      ImGuiID
--- @field ParentViewport        ImGuiViewport
--- @field DrawData              ImDrawData
--- @field RendererUserData      any
--- @field PlatformUserData      any
--- @field PlatformHandle        any
--- @field PlatformHandleRaw     any
--- @field PlatformWindowCreated bool
--- @field PlatformRequestMove   bool
--- @field PlatformRequestResize bool
--- @field PlatformRequestClose  bool
MT.ImGuiViewport = {}
MT.ImGuiViewport.__index = MT.ImGuiViewport

function MT.ImGuiViewport:GetCenter()
    return ImVec2(self.Pos.x + self.Size.x * 0.5, self.Pos.y + self.Size.y * 0.5)
end

function MT.ImGuiViewport:GetWorkCenter()
    return ImVec2(self.WorkPos.x + self.WorkSize.x * 0.5, self.WorkPos.y + self.WorkSize.y * 0.5)
end

--- @return ImGuiViewport
--- @nodiscard
function ImGuiViewport()
    return setmetatable({
        ID       = 0, -- Unique identifier for the viewport
        Flags    = 0, -- See ImGuiViewportFlags_
        Pos      = ImVec2(), -- Main Area: Position of the viewport (Dear ImGui coordinates are the same as OS desktop/native coordinates)
        Size     = ImVec2(), -- Main Area: Size of the viewport.
        FramebufferScale = ImVec2(), -- Density of the viewport for Retina display (always 1,1 on Windows, may be 2,2 etc on macOS/iOS). This will affect font rasterizer density.
        WorkPos  = ImVec2(), -- Work Area: Position of the viewport minus task bars, menus bars, status bars (>= Pos)
        WorkSize = ImVec2(), -- Work Area: Size of the viewport minus task bars, menu bars, status bars (<= Size)
        DpiScale = 0, -- 1.0f = 96 DPI = No extra scale.

        PlatformHandle = nil, -- void* to hold higher-level, platform window handle (e.g. HWND for Win32 backend, Uint32 WindowID for SDL, GLFWWindow* for GLFW), for FindViewportByPlatformHandle().
        PlatformHandleRaw = nil, -- void* to hold lower-level, platform-native window handle (always HWND on Win32 platform, unused for other platforms).
        PlatformWindowCreated = false -- Platform window has been created (Platform_CreateWindow() has been called). This is false during the first frame where a viewport is being created.
    }, MT.ImGuiViewport)
end

-------------------------------------------------------------------------------
-- [SECTION] ImGuiPlatformIO + other Platform Dependent Interfaces (ImGuiPlatformMonitor, ImGuiPlatformImeData)
-------------------------------------------------------------------------------

-- Access via ImGui.GetPlatformIO()
--- @class ImGuiPlatformIO
--- @field Platform_GetClipboardTextFn fun(ctx?: ImGuiContext): string
--- @field Platform_CreateWindow       fun(vp: ImGuiViewport)
--- @field Platform_OnChangedViewport  fun(vp: ImGuiViewport)
--- @field Monitors                    ImVector<ImGuiPlatformMonitor>
--- @field Textures                    ImVector<ImTextureData>
--- @field Viewports                   ImVector<ImGuiViewport>
MT.ImGuiPlatformIO = {}
MT.ImGuiPlatformIO.__index = MT.ImGuiPlatformIO

--- @return ImGuiPlatformIO
--- @nodiscard
function ImGuiPlatformIO()
    local this = {
        -------------------------------------------------------------------------------
        -- Input - Interface with OS and Platform backend (most common stuff)
        -------------------------------------------------------------------------------

        -- Optional: Access OS clipboard
        -- (default to use native Win32 clipboard on Windows, otherwise uses a private clipboard. Override to access OS clipboard on other architectures)
        Platform_GetClipboardTextFn = nil, -- Should return nil on failure (e.g. clipboard data is not text).
        Platform_SetClipboardTextFn = nil,

        -- Optional: Open link/folder/file in OS Shell
        -- (default to use ShellExecuteW() on Windows, system() on Linux/Mac. expected to return false on failure, but some platforms may always return true)
        Platform_OpenInShellFn = nil,
        Platform_OpenInShellUserData = nil,

        -------------------------------------------------------------------------------
        -- Input - Interface with Renderer Backend
        -------------------------------------------------------------------------------

        -- Optional: Maximum texture size supported by renderer (used to adjust how we size textures). 0 if not known.
        Renderer_TextureMaxWidth = 0,
        Renderer_TextureMaxHeight = 0,

        -- Written by some backends during ImGui_ImplXXXX_RenderDrawData() call to point backend_specific ImGui_ImplXXXX_RenderState* structure.
        Renderer_RenderState = nil,

        -- (Optional) Monitor list
        -- - Updated by: app/backend. Update every frame to dynamically support changing monitor or DPI configuration.
        -- - Used by: dear imgui to query DPI info, clamp popups/tooltips within same monitor and not have them straddle monitors.
        Monitors = ImVector(),
        -- Textures list (the list is updated by calling ImGui.EndFrame or ImGui.Render)
        -- The ImGui_ImplXXXX_RenderDrawData() function of each backend generally access this via ImDrawData::Textures which points to this. The array is available here mostly because backends will want to destroy textures on shutdown.
        Textures = ImVector(), -- List of textures used by Dear ImGui (most often 1) + contents of external texture list is automatically appended into this.
        -- Viewports list (the list is updated by calling ImGui.EndFrame or ImGui.Render)
        -- (in the future we will attempt to organize this feature to remove the need for a "main viewport")
        Viewports = ImVector(), -- Main viewports, followed by all secondary viewports.

        -- Optional: Platform locale
        -- [Experimental] Configure decimal point e.g. '.' or ',' useful for some languages (e.g. German), generally pulled from *localeconv()->decimal_point
        Platform_LocaleDecimalPoint = 46, -- '.'

        Platform_OnChangedViewport = nil, -- (Optional) [BETA] FIXME-DPI: DPI handling: Called during Begin() every time the viewport we are outputting into changes, so backend has a chance to swap fonts to adjust style.
    }

    return setmetatable(this, MT.ImGuiPlatformIO)
end

-- (Optional) This is required when enabling multi-viewport. Represent the bounds of each connected monitor/display and their DPI.
-- We use this information for multiple DPI support + clamping the position of popups and tooltips so they don't straddle multiple monitors.
--- @class ImGuiPlatformMonitor
--- @field MainPos        ImVec2
--- @field MainSize       ImVec2
--- @field WorkPos        ImVec2
--- @field WorkSize       ImVec2
--- @field DpiScale       float
--- @field PlatformHandle any

--- @return ImGuiPlatformMonitor
--- @nodiscard
function ImGuiPlatformMonitor()
    return {
        MainPos  = ImVec2(0, 0), -- Coordinates of the area displayed on this monitor (Min = upper left, Max = bottom right)
        MainSize = ImVec2(0, 0),
        WorkPos  = ImVec2(0, 0), -- Coordinates without task bars / side bars / menu bars. Used to avoid positioning popups/tooltips inside this region. If you don't have this info, please copy the value for MainPos/MainSize.
        WorkSize = ImVec2(0, 0),
        DpiScale = 1.0, -- 1.0f = 96 DPI

        PlatformHandle = nil -- Backend dependant data (e.g. HMONITOR, GLFWmonitor*, SDL Display Index, NSScreen*)
    }
end

-------------------------------------------------------------------------------
-- [SECTION] Flags & Enumerations
-------------------------------------------------------------------------------

-- Flags for ImGui.Begin()
-- (Those are per-window flags. There are shared flags in ImGuiIO: io.ConfigWindowsResizeFromEdges and io.ConfigWindowsMoveFromTitleBarOnly)
--- @enum ImGuiWindowFlags
ImGuiWindowFlags = {
    None                      = 0,
    NoTitleBar                = bitLShift(1, 0), -- Disable title-bar
    NoResize                  = bitLShift(1, 1), -- Disable user resizing with the lower-right grip
    NoMove                    = bitLShift(1, 2), -- Disable user moving the window
    NoScrollbar               = bitLShift(1, 3), -- Disable scrollbars (window can still scroll with mouse or programmatically)
    NoScrollWithMouse         = bitLShift(1, 4), -- Disable user vertically scrolling with mouse wheel. On child window, mouse wheel will be forwarded to the parent unless NoScrollbar is also set.
    NoCollapse                = bitLShift(1, 5), -- Disable user collapsing window by double-clicking on it. Also referred to as Window Menu Button (e.g. within a docking node).
    AlwaysAutoResize          = bitLShift(1, 6), -- Resize every window to its content every frame
    NoBackground              = bitLShift(1, 7), -- Disable drawing background color (WindowBg, etc.) and outside border. Similar as using SetNextWindowBgAlpha(0.0f).
    NoSavedSettings           = bitLShift(1, 8), -- Never load/save settings in .ini file
    NoMouseInputs             = bitLShift(1, 9), -- Disable catching mouse, hovering test with pass through.
    MenuBar                   = bitLShift(1, 10), -- Has a menu-bar
    HorizontalScrollbar       = bitLShift(1, 11), -- Allow horizontal scrollbar to appear (off by default). You may use SetNextWindowContentSize(ImVec2(width,0.0f)); prior to calling Begin() to specify width. Read code in imgui_demo in the "Horizontal Scrolling" section.
    NoFocusOnAppearing        = bitLShift(1, 12), -- Disable taking focus when transitioning from hidden to visible state
    NoBringToFrontOnFocus     = bitLShift(1, 13), -- Disable bringing window to front when taking focus (e.g. clicking on it or programmatically giving it focus)
    AlwaysVerticalScrollbar   = bitLShift(1, 14), -- Always show vertical scrollbar (even if ContentSize.y < Size.y)
    AlwaysHorizontalScrollbar = bitLShift(1, 15), -- Always show horizontal scrollbar (even if ContentSize.x < Size.x)
    NoNavInputs               = bitLShift(1, 16), -- No keyboard/gamepad navigation within the window
    NoNavFocus                = bitLShift(1, 17), -- No focusing toward this window with keyboard/gamepad navigation (e.g. skipped by Ctrl+Tab)
    UnsavedDocument           = bitLShift(1, 18), -- Display a dot next to the title. When used in a tab/docking context, tab is selected when clicking the X + closure is not assumed (will wait for user to stop submitting the tab). Otherwise closure is assumed when pressing the X, so if you keep submitting the tab may reappear at end of tab bar.
    NoDocking                 = bitLShift(1, 19), -- Disable docking of this window
    -- [Internal]
    DockNodeHost              = bitLShift(1, 23), -- Don't use! For internal use by Begin()/NewFrame()
    ChildWindow               = bitLShift(1, 24), -- Don't use! For internal use by BeginChild()
    Tooltip                   = bitLShift(1, 25), -- Don't use! For internal use by BeginTooltip()
    Popup                     = bitLShift(1, 26), -- Don't use! For internal use by BeginPopup()
    Modal                     = bitLShift(1, 27), -- Don't use! For internal use by BeginPopupModal()
    ChildMenu                 = bitLShift(1, 28) -- Don't use! For internal use by BeginMenu()
}

-- [Internal]
ImGuiWindowFlags.NoNav        = bitOr(ImGuiWindowFlags.NoNavInputs, ImGuiWindowFlags.NoNavFocus)
ImGuiWindowFlags.NoDecoration = bitOr(ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoResize, ImGuiWindowFlags.NoScrollbar, ImGuiWindowFlags.NoCollapse)
ImGuiWindowFlags.NoInputs     = bitOr(ImGuiWindowFlags.NoMouseInputs, ImGuiWindowFlags.NoNavInputs, ImGuiWindowFlags.NoNavFocus)

-- Flags for ImGui.PushItemFlag()
-- (Those are shared by all submitted items)
--- @enum ImGuiItemFlags
ImGuiItemFlags = {
    None                  = 0, -- Default:
    NoTabStop             = bitLShift(1, 0), -- false    -- Disable keyboard tabbing. This is a "lighter" version of ImGuiItemFlags.NoNav.
    NoNav                 = bitLShift(1, 1), -- false    -- Disable any form of focusing: keyboard/gamepad directional navigation and SetKeyboardFocusHere() calls.
    NoNavDefaultFocus     = bitLShift(1, 2), -- false    -- Disable item being a candidate for default focus (e.g. used by title bar items).
    ButtonRepeat          = bitLShift(1, 3), -- false    -- Any button-like behavior will have repeat mode enabled (based on io.KeyRepeatDelay and io.KeyRepeatRate values). Note that you can also call IsItemActive() after any button to tell if it is being held.
    AutoClosePopups       = bitLShift(1, 4), -- true     -- MenuItem()/Selectable() automatically close their parent popup window.
    AllowDuplicateId      = bitLShift(1, 5), -- false    -- Allow submitting an item with the same identifier as an item already submitted this frame without triggering a warning tooltip if io.ConfigDebugHighlightIdConflicts is set.
    Disabled              = bitLShift(1, 6), -- false    -- [Internal] Disable interactions. DOES NOT affect visuals. This is used by BeginDisabled()/EndDisabled() and only provided here so you can read back via GetItemFlags().
    -------------------------------------------------------------------------------
    -- LiveEdit refers to applying edits to backing variables _while_ typing a value using the keyboard.
    -- Widget:                          | Input:   | w/ LiveEdit:    | Output:
    --   InputText()                    |   "123"  |   on(default)   |  "1" then "12" then "123"
    --   InputText()                    |   "123"  |   off           |  "123" after validating or tabbing out or losing focus.
    --   DragFloat(), SliderInt(), etc. |   "123"  |   on*           |  1 then 12 then 123
    --   DragFloat(), SliderInt(), etc. |   "123"  |   off(default)* |  123 after validation or tabbing out or losing focus.
    -- (*) Since 1.92.9 (July 2026), ImGuiItemFlags.LiveEditOnInputScalar is OFF by default. In prior version it was ON for everything.
    -------------------------------------------------------------------------------
    LiveEditOnInputText   = bitLShift(1, 7), -- true     -- InputText: apply keyboard edits to backing value while typing. Otherwise, edits are applied when validating, tabbing out or losing focus.
    LiveEditOnInputScalar = bitLShift(1, 8) -- false    -- DragXXX, SliderXXX, InputScalar: apply keyboard edits to backing value while typing. Otherwise, edits are applied when validating, tabbing out or losing focus.
}

ImGuiItemFlags.LiveEditOnInput = bitOr(ImGuiItemFlags.LiveEditOnInputText, ImGuiItemFlags.LiveEditOnInputScalar)

-- Status flags for an already submitted item
-- - output: stored in g.LastItemData.StatusFlags
--- @enum ImGuiItemStatusFlags
ImGuiItemStatusFlags = {
    None             = 0,
    HoveredRect      = bitLShift(1, 0), -- Mouse position is within item rectangle (does NOT mean that the window is in correct z-order and can be hovered!, this is only one part of the most-common IsItemHovered test)
    HasDisplayRect   = bitLShift(1, 1), -- g.LastItemData.DisplayRect is valid
    Edited           = bitLShift(1, 2), -- Value exposed by item was edited in the current frame (should match the bool return value of most widgets)
    ToggledSelection = bitLShift(1, 3), -- Set when Selectable(), TreeNode() reports toggling a selection. We can't report "Selected", only state changes, in order to easily handle clipping with less issues.
    ToggledOpen      = bitLShift(1, 4), -- Set when TreeNode() reports toggling their open state.
    HasDeactivated   = bitLShift(1, 5), -- Set if the widget/group is able to provide data for the ImGuiItemStatusFlags.Deactivated flag.
    Deactivated      = bitLShift(1, 6), -- Only valid if ImGuiItemStatusFlags.HasDeactivated is set.
    HoveredWindow    = bitLShift(1, 7), -- Override the HoveredWindow test to allow cross-window hover testing.
    Visible          = bitLShift(1, 8), -- [WIP] Set when item is overlapping the current clipping rectangle (Used internally. Please don't use yet: API/system will change as we refactor Itemadd()).
    HasClipRect      = bitLShift(1, 9), -- g.LastItemData.ClipRect is valid.
    HasShortcut      = bitLShift(1, 10), -- g.LastItemData.Shortcut valid. Set by SetNextItemShortcut() -> ItemAdd().
    --ImGuiItemStatusFlags.FocusedByTabbing = 1 << 8,   -- Removed IN 1.90.1 (Dec 2023). The trigger is part of g.NavActivateId. See commit 54c1bdeceb.
    EditedInternal   = bitLShift(1, 11) -- Similar to ImGuiItemStatusFlags.Edited but bypassing ImGuiItemFlags.NoMarkEdited.
}

-- Flags for ImGui.BeginChild()
-- (Legacy: bit 0 must always correspond to ImGuiChildFlags.Borders to be backward compatible with old API using 'bool border = false'.)
-- About using AutoResizeX/AutoResizeY flags:
-- - May be combined with SetNextWindowSizeConstraints() to set a min/max size for each axis (see "Demo->Child->Auto-resize with Constraints").
-- - Size measurement for a given axis is only performed when the child window is within visible boundaries, or is just appearing.
--   - This allows BeginChild() to return false when not within boundaries (e.g. when scrolling), which is more optimal. BUT it won't update its auto-size while clipped.
--     While not perfect, it is a better default behavior as the always-on performance gain is more valuable than the occasional "resizing after becoming visible again" glitch.
--   - You may also use ImGuiChildFlags.AlwaysAutoResize to force an update even when child window is not in view.
--     HOWEVER PLEASE UNDERSTAND THAT DOING SO WILL PREVENT BeginChild() FROM EVER RETURNING FALSE, disabling benefits of coarse clipping.
--- @enum ImGuiChildFlags
ImGuiChildFlags = {
    None                   = 0,
    Borders                = bitLShift(1, 0), -- Show an outer border and enable WindowPadding. (IMPORTANT: this is always == 1 == true for legacy reason)
    AlwaysUseWindowPadding = bitLShift(1, 1), -- Pad with style.WindowPadding even if no border are drawn (no padding by default for non-bordered child windows because it makes more sense)
    ResizeX                = bitLShift(1, 2), -- Allow resize from right border (layout direction). Enable .ini saving (unless ImGuiWindowFlags.NoSavedSettings passed to window flags)
    ResizeY                = bitLShift(1, 3), -- Allow resize from bottom border (layout direction). "
    AutoResizeX            = bitLShift(1, 4), -- Enable auto-resizing width. Read "IMPORTANT: Size measurement" details above.
    AutoResizeY            = bitLShift(1, 5), -- Enable auto-resizing height. Read "IMPORTANT: Size measurement" details above.
    AlwaysAutoResize       = bitLShift(1, 6), -- Combined with AutoResizeX/AutoResizeY. Always measure size even when child is hidden, always return true, always disable clipping optimization! NOT RECOMMENDED.
    FrameStyle             = bitLShift(1, 7), -- Style the child window like a framed item: use FrameBg, FrameRounding, FrameBorderSize, FramePadding instead of ChildBg, ChildRounding, ChildBorderSize, WindowPadding.
    NavFlattened           = bitLShift(1, 8) -- [BETA] Share focus scope, allow keyboard/gamepad navigation to cross over parent border to this child or between sibling child windows.
}

ImGuiChildFlags.ResizeBoth = bitOr(ImGuiChildFlags.ResizeX, ImGuiChildFlags.ResizeY)
ImGuiChildFlags.ResizeXAndY = ImGuiChildFlags.ResizeBoth

--- @enum ImGuiNextItemDataFlags
ImGuiNextItemDataFlags = {
    None           = 0,
    HasWidth       = bitLShift(1, 0),
    HasOpen        = bitLShift(1, 1),
    HasShortcut    = bitLShift(1, 2),
    HasRefVal      = bitLShift(1, 3),
    HasStorageID   = bitLShift(1, 4),
    HasColorMarker = bitLShift(1, 5)
}

-- Flags for ImDrawList functions
--- @enum ImDrawFlags
ImDrawFlags = {
    None                    = 0,
    -- - Rounding default to ImDrawFlags.RoundCornersAll when 'rounding > 0'.
    -- - So you only need to use the ImDrawFlags.RoundCornersXXX flags if you want a special configuration (e.g. a rectangle with one rounded corner).
    -- Rounding for AddRectXXX(), PathRect() ------ -- Prim/Scope?
    RoundCornersTopLeft     = bitLShift(1, 4), -- OK   --    -- Round top-left corner only (when 'rounding > 0.0f', we default to all corners).
    RoundCornersTopRight    = bitLShift(1, 5), -- OK   --    -- Round top-right corner only (when 'rounding > 0.0f', we default to all corners).
    RoundCornersBottomLeft  = bitLShift(1, 6), -- OK   --    -- Round bottom-left corner only (when 'rounding > 0.0f', we default to all corners).
    RoundCornersBottomRight = bitLShift(1, 7), -- OK   --    -- Round bottom-right corner only (when 'rounding > 0.0f', we default to all corners).
    RoundCornersNone        = bitLShift(1, 8), -- OK   --    -- Disable rounding even when 'rounding > 0.0f'. This value is NOT zero, it is NOT an implicit flag!
    -- Stroke Options ----------------------------- -- Prim/Scope?
    Closed                  = bitLShift(1, 9) -- OK   --     -- PathStroke(), AddPolyline(): specify that shape should be closed.
}

ImDrawFlags.RoundCornersTop      = bitOr(ImDrawFlags.RoundCornersTopLeft, ImDrawFlags.RoundCornersTopRight)
ImDrawFlags.RoundCornersBottom   = bitOr(ImDrawFlags.RoundCornersBottomLeft, ImDrawFlags.RoundCornersBottomRight)
ImDrawFlags.RoundCornersLeft     = bitOr(ImDrawFlags.RoundCornersBottomLeft, ImDrawFlags.RoundCornersTopLeft)
ImDrawFlags.RoundCornersRight    = bitOr(ImDrawFlags.RoundCornersBottomRight, ImDrawFlags.RoundCornersTopRight)
ImDrawFlags.RoundCornersAll      = bitOr(ImDrawFlags.RoundCornersTopLeft, ImDrawFlags.RoundCornersTopRight, ImDrawFlags.RoundCornersBottomLeft, ImDrawFlags.RoundCornersBottomRight) -- (Default!!)
ImDrawFlags.RoundCornersDefault_ = ImDrawFlags.RoundCornersAll
ImDrawFlags.RoundCornersMask_    = bitOr(ImDrawFlags.RoundCornersAll, ImDrawFlags.RoundCornersNone) -- [Internal]
ImDrawFlags.InvalidMask_         = 0x8000000F -- [Internal] == 0x8000000F. Reserved to detect misuses.

--- @enum ImDrawListFlags
ImDrawListFlags = {
    None                   = 0,
    AntiAliasedLines       = bitLShift(1, 0),
    AntiAliasedLinesUseTex = bitLShift(1, 1),
    AntiAliasedFill        = bitLShift(1, 2),
    AllowVtxOffset         = bitLShift(1, 3),
    TextNoPixelSnap        = bitLShift(1, 4)
}

-- Font flags
-- (in future versions as we redesign font loading API, this will become more important and better documented. for now please consider this as internal/advanced use)
--- @enum ImFontFlags
ImFontFlags = {
    None            = 0,
    NoLoadError     = bitLShift(1, 1), -- Disable throwing an error/assert when calling AddFontXXX() with missing file/data. Calling code is expected to check AddFontXXX() return value.
    NoLoadGlyphs    = bitLShift(1, 2), -- [Internal] Disable loading new glyphs.
    LockBakedSizes  = bitLShift(1, 3), -- [Internal] Disable loading new baked sizes, disable garbage collecting current ones. e.g. if you want to lock a font to a single size. Important: if you use this to preload given sizes, consider the possibility of multiple font density used on Retina display.
    ImplicitRefSize = bitLShift(1, 4) -- [Internal] Reference size was not set explicitly.
}

-- Enumeration for AddMouseSourceEvent() actual source of Mouse Input data.
-- Historically we use "Mouse" terminology everywhere to indicate pointer data, e.g. MousePos, IsMousePressed(), io.AddMousePosEvent()
-- But that "Mouse" data can come from different source which occasionally may be useful for application to know about.
-- You can submit a change of pointer type using io.AddMouseSourceEvent().
--- @enum ImGuiMouseSource
ImGuiMouseSource = {
    Mouse       = 0, -- Input is coming from an actual mouse.
    TouchScreen = 1, -- Input is coming from a touch screen (no hovering prior to initial press, less precise initial press aiming, dual-axis wheeling possible).
    Pen         = 2, -- Input is coming from a pressure/magnetic pen (often used in conjunction with high-sampling rates).
    COUNT       = 3
}

-- Enumeration for ImGui.SetNextWindow***(), SetWindow***(), SetNextItem***() functions
-- Represent a condition.
-- Important: Treat as a regular enum! Do NOT combine multiple values using binary operators! All the functions above treat 0 as a shortcut to ImGuiCond.Always.
--- @enum ImGuiCond
ImGuiCond = {
    None          = 0, -- No condition (always set the variable), same as _Always
    Always        = bitLShift(1, 0), -- No condition (always set the variable), same as _None
    Once          = bitLShift(1, 1), -- Set the variable once per runtime session (only the first call will succeed)
    FirstUseEver  = bitLShift(1, 2), -- Set the variable if the object/window has no persistently saved data (no entry in .ini file)
    Appearing     = bitLShift(1, 3) -- Set the variable if the object/window is appearing after being hidden/inactive (or the first time)
}

-- Flags for Shortcut(), SetNextItemShortcut(),
-- (and for upcoming extended versions of IsKeyPressed(), IsMouseClicked(), Shortcut(), SetKeyOwner(), SetItemKeyOwner() that are still in imgui_internal.h)
-- Don't mistake with ImGuiInputTextFlags! (which is for ImGui.InputText() function)
--- @enum ImGuiInputFlags
ImGuiInputFlags = {
    None                 = 0,
    Repeat               = bitLShift(1, 0), -- Enable repeat. Return true on successive repeats. Default for legacy IsKeyPressed(). NOT Default for legacy IsMouseClicked(). MUST BE == 1.
    -- Flags for Shortcut(), SetNextItemShortcut()
    -- - Routing policies: RouteGlobal+OverActive >> RouteActive or RouteFocused (if owner is active item) >> RouteGlobal+OverFocused >> RouteFocused (if in focused window stack) >> RouteGlobal.
    -- - Default policy is RouteFocused. Can select only 1 policy among all available.
    RouteActive          = bitLShift(1, 10), -- Route to active item only.
    RouteFocused         = bitLShift(1, 11), -- Route to windows in the focus stack (DEFAULT). Deep-most focused window takes inputs. Active item takes inputs over deep-most focused window.
    RouteGlobal          = bitLShift(1, 12), -- Global route (unless a focused window or active item registered the route).
    RouteAlways          = bitLShift(1, 13), -- Do not register route, poll keys directly.
    -- - Routing options
    RouteOverFocused     = bitLShift(1, 14), -- Option: global route: higher priority than focused route (unless active item in focused route).
    RouteOverActive      = bitLShift(1, 15), -- Option: global route: higher priority than active item. Unlikely you need to use that: will interfere with every active items, e.g. Ctrl+A registered by InputText will be overridden by this. May not be fully honored as user/internal code is likely to always assume they can access keys when active.
    RouteUnlessBgFocused = bitLShift(1, 16), -- Option: global route: will not be applied if underlying background/void is focused (== no Dear ImGui windows are focused). Useful for overlay applications.
    RouteFromRootWindow  = bitLShift(1, 17), -- Option: route evaluated from the point of view of root window rather than current window.
    -- Flags for SetNextItemShortcut()
    Tooltip              = bitLShift(1, 18) -- Automatically display a tooltip when hovering item [BETA] Unsure of right api (opt-in/opt-out)
}

-- Flags for InvisibleButton() [extended in imgui_internal.h]
--- @enum ImGuiButtonFlags
ImGuiButtonFlags = {
    None                          = 0,
    MouseButtonLeft               = bitLShift(1, 0), -- React on left mouse button (default)
    MouseButtonRight              = bitLShift(1, 1), -- React on right mouse button
    MouseButtonMiddle             = bitLShift(1, 2), -- React on center mouse button
    EnableNav                     = bitLShift(1, 3), -- InvisibleButton(): do not disable navigation/tabbing. Otherwise disabled by default.
    PressedOnClick                = bitLShift(1, 4), -- return true on click (mouse down event)
    PressedOnClickRelease         = bitLShift(1, 5), -- [Default] return true on click + release on same item <-- this is what the majority of Button are using
    PressedOnClickReleaseAnywhere = bitLShift(1, 6), -- return true on click + release even if the release event is not done while hovering the item
    PressedOnRelease              = bitLShift(1, 7), -- return true on release (default requires click+release). Prior to 2026/03/20 this implied ImGuiButtonFlags.NoHoldingActiveId but they are separate now.
    PressedOnDoubleClick          = bitLShift(1, 8), -- return true on double-click (default requires click+release)
    PressedOnDragDropHold         = bitLShift(1, 9), -- return true when held into while we are drag and dropping another item (used by e.g. tree nodes, collapsing headers)
    --ImGuiButtonFlags.Repeat               = 1 << 10,  -- hold to repeat -> use ImGuiItemFlags.ButtonRepeat instead.
    FlattenChildren               = bitLShift(1, 11), -- allow interactions even if a child window is overlapping
    AllowOverlap                  = bitLShift(1, 12), -- Hit testing will allow subsequent widgets to overlap this one. Require previous frame HoveredId to match before being usable. Shortcut to calling SetNextItemAllowOverlap().
    --ImGuiButtonFlags.DontClosePopups      = 1 << 13,  -- disable automatically closing parent popup on press
    --ImGuiButtonFlags.Disabled             = 1 << 14,  -- disable interactions -> use BeginDisabled() or ImGuiItemFlags.Disabled
    AlignTextBaseLine             = bitLShift(1, 15), -- vertically align button to match text baseline - ButtonEx() only -- FIXME: Should be removed and handled by SmallButton(), not possible currently because of DC.CursorPosPrevLine
    NoKeyModsAllowed              = bitLShift(1, 16), -- disable mouse interaction if a key modifier is held
    NoHoldingActiveId             = bitLShift(1, 17), -- don't set ActiveId while holding the mouse (ImGuiButtonFlags.PressedOnClick only)
    NoNavFocus                    = bitLShift(1, 18), -- don't override navigation focus when activated (FIXME: this is essentially used every time an item uses ImGuiItemFlags.NoNav, but because legacy specs don't requires LastItemData to be set ButtonBehavior(), we can't poll g.LastItemData.ItemFlags)
    NoHoveredOnFocus              = bitLShift(1, 19), -- don't report as hovered when nav focus is on this item
    NoSetKeyOwner                 = bitLShift(1, 20), -- don't set key/input owner on the initial click (note: mouse buttons are keys! often, the key in question will be ImGuiKey.MouseLeft!)
    NoTestKeyOwner                = bitLShift(1, 21), -- don't test key/input owner when polling the key (note: mouse buttons are keys! often, the key in question will be ImGuiKey.MouseLeft!)
    NoFocus                       = bitLShift(1, 22) -- [EXPERIMENTAL: Not very well specced]. Don't focus parent window when clicking.
}

ImGuiButtonFlags.MouseButtonMask_  = bitOr(ImGuiButtonFlags.MouseButtonLeft, ImGuiButtonFlags.MouseButtonRight, ImGuiButtonFlags.MouseButtonMiddle) -- [Internal]
ImGuiButtonFlags.PressedOnMask_    = bitOr(ImGuiButtonFlags.PressedOnClick, ImGuiButtonFlags.PressedOnClickRelease, ImGuiButtonFlags.PressedOnClickReleaseAnywhere, ImGuiButtonFlags.PressedOnRelease, ImGuiButtonFlags.PressedOnDoubleClick, ImGuiButtonFlags.PressedOnDragDropHold)
ImGuiButtonFlags.PressedOnDefault_ = ImGuiButtonFlags.PressedOnClickRelease
ImGuiButtonFlags.NoKeyModifiers    = ImGuiButtonFlags.NoKeyModsAllowed

-- Enumeration for PushStyleVar() / PopStyleVar() to temporarily modify the ImGuiStyle structure.
-- - The enum only refers to fields of ImGuiStyle which makes sense to be pushed/popped inside UI code.
--   During initialization or between frames, feel free to just poke into ImGuiStyle directly.
-- - When changing this enum, you need to update the associated internal table GStyleVarInfo[] accordingly. This is where we link enum values to members offset/type.
--- @enum ImGuiStyleVar
ImGuiStyleVar = {
    -- Enum name -------------------------- -- Member in ImGuiStyle structure (see ImGuiStyle for descriptions)
    Alpha                       = 0, -- float     Alpha
    DisabledAlpha               = 1, -- float     DisabledAlpha
    WindowPadding               = 2, -- ImVec2    WindowPadding
    WindowRounding              = 3, -- float     WindowRounding
    WindowBorderSize            = 4, -- float     WindowBorderSize
    WindowMinSize               = 5, -- ImVec2    WindowMinSize
    WindowTitleAlign            = 6, -- ImVec2    WindowTitleAlign
    ChildRounding               = 7, -- float     ChildRounding
    ChildBorderSize             = 8, -- float     ChildBorderSize
    PopupRounding               = 9, -- float     PopupRounding
    PopupBorderSize             = 10, -- float     PopupBorderSize
    FramePadding                = 11, -- ImVec2    FramePadding
    FrameRounding               = 12, -- float     FrameRounding
    FrameBorderSize             = 13, -- float     FrameBorderSize
    ItemSpacing                 = 14, -- ImVec2    ItemSpacing
    ItemInnerSpacing            = 15, -- ImVec2    ItemInnerSpacing
    IndentSpacing               = 16, -- float     IndentSpacing
    CellPadding                 = 17, -- ImVec2    CellPadding
    ScrollbarSize               = 18, -- float     ScrollbarSize
    ScrollbarRounding           = 19, -- float     ScrollbarRounding
    ScrollbarPadding            = 20, -- float     ScrollbarPadding
    GrabMinSize                 = 21, -- float     GrabMinSize
    GrabRounding                = 22, -- float     GrabRounding
    ImageRounding               = 23, -- float     ImageRounding
    ImageBorderSize             = 24, -- float     ImageBorderSize
    TabRounding                 = 25, -- float     TabRounding
    TabBorderSize               = 26, -- float     TabBorderSize
    TabMinWidthBase             = 27, -- float     TabMinWidthBase
    TabMinWidthShrink           = 28, -- float     TabMinWidthShrink
    TabBarBorderSize            = 29, -- float     TabBarBorderSize
    TabBarOverlineSize          = 30, -- float     TabBarOverlineSize
    TableAngledHeadersAngle     = 31, -- float     TableAngledHeadersAngle
    TableAngledHeadersTextAlign = 32, -- ImVec2  TableAngledHeadersTextAlign
    TreeLinesSize               = 33, -- float     TreeLinesSize
    TreeLinesRounding           = 34, -- float     TreeLinesRounding
    MenuItemRounding            = 35, -- float     MenuItemRounding
    SelectableRounding          = 36, -- float     SelectableRounding
    DragDropTargetRounding      = 37, -- float     DragDropTargetRounding
    ButtonTextAlign             = 38, -- ImVec2    ButtonTextAlign
    SelectableTextAlign         = 39, -- ImVec2    SelectableTextAlign
    SeparatorTextBorderSize     = 40, -- float     SeparatorTextBorderSize
    SeparatorTextAlign          = 41, -- ImVec2    SeparatorTextAlign
    SeparatorTextPadding        = 42, -- ImVec2    SeparatorTextPadding
    COUNT                       = 43
}

-- Flags for ImGui.IsItemHovered(), ImGui.IsWindowHovered()
-- Note: if you are trying to check whether your mouse should be dispatched to Dear ImGui or to your app, you should use 'io.WantCaptureMouse' instead! Please read the FAQ!
-- Note: windows with the ImGuiWindowFlags.NoInputs flag are ignored by IsWindowHovered() calls.
--- @enum ImGuiHoveredFlags
ImGuiHoveredFlags = {
    None                         = 0, -- Return true if directly over the item/window, not obstructed by another window, not obstructed by an active popup or modal blocking inputs under them.
    ChildWindows                 = bitLShift(1, 0), -- IsWindowHovered() only: Return true if any children of the window is hovered
    RootWindow                   = bitLShift(1, 1), -- IsWindowHovered() only: Test from root window (top most parent of the current hierarchy)
    AnyWindow                    = bitLShift(1, 2), -- IsWindowHovered() only: Return true if any window is hovered
    NoPopupHierarchy             = bitLShift(1, 3), -- IsWindowHovered() only: Do not consider popup hierarchy (do not treat popup emitter as parent of popup) (when used with _ChildWindows or _RootWindow)
    DockHierarchy                = bitLShift(1, 4), -- IsWindowHovered() only: Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
    AllowWhenBlockedByPopup      = bitLShift(1, 5), -- Return true even if a popup window is normally blocking access to this item/window
    --ImGuiHoveredFlags.AllowWhenBlockedByModal     = 1 << 6,   -- Return true even if a modal popup window is normally blocking access to this item/window. FIXME-TODO: Unavailable yet.
    AllowWhenBlockedByActiveItem = bitLShift(1, 7), -- Return true even if an active item is blocking access to this item/window. Useful for Drag and Drop patterns.
    AllowWhenOverlappedByItem    = bitLShift(1, 8), -- IsItemHovered() only: Return true even if the item uses AllowOverlap mode and is overlapped by another hoverable item.
    AllowWhenOverlappedByWindow  = bitLShift(1, 9), -- IsItemHovered() only: Return true even if the position is obstructed or overlapped by another window.
    AllowWhenDisabled            = bitLShift(1, 10), -- IsItemHovered() only: Return true even if the item is disabled
    NoNavOverride                = bitLShift(1, 11), -- IsItemHovered() only: Disable using keyboard/gamepad navigation state when active, always query mouse
    -- Tooltips mode
    -- - typically used in IsItemHovered() + SetTooltip() sequence.
    -- - this is a shortcut to pull flags from 'style.HoverFlagsForTooltipMouse' or 'style.HoverFlagsForTooltipNav' where you can reconfigure desired behavior.
    --   e.g. 'HoverFlagsForTooltipMouse' defaults to 'ImGuiHoveredFlags.Stationary | ImGuiHoveredFlags.DelayShort | ImGuiHoveredFlags.AllowWhenDisabled'.
    -- - for frequently actioned or hovered items providing a tooltip, you want may to use ImGuiHoveredFlags.ForTooltip (stationary + delay) so the tooltip doesn't show too often.
    -- - for items which main purpose is to be hovered, or items with low affordance, or in less consistent apps, prefer no delay or shorter delay.
    ForTooltip                   = bitLShift(1, 12), -- Shortcut for standard flags when using IsItemHovered() + SetTooltip() sequence.
    -- (Advanced) Mouse Hovering delays.
    -- - generally you can use ImGuiHoveredFlags.ForTooltip to use application-standardized flags.
    -- - use those if you need specific overrides.
    Stationary                   = bitLShift(1, 13), -- Require mouse to be stationary for style.HoverStationaryDelay (~0.15 sec) _at least one time_. After this, can move on same item/window. Using the stationary test tends to reduces the need for a long delay.
    DelayNone                    = bitLShift(1, 14), -- IsItemHovered() only: Return true immediately (default). As this is the default you generally ignore this.
    DelayShort                   = bitLShift(1, 15), -- IsItemHovered() only: Return true after style.HoverDelayShort elapsed (~0.15 sec) (shared between items) + requires mouse to be stationary for style.HoverStationaryDelay (once per item).
    DelayNormal                  = bitLShift(1, 16), -- IsItemHovered() only: Return true after style.HoverDelayNormal elapsed (~0.40 sec) (shared between items) + requires mouse to be stationary for style.HoverStationaryDelay (once per item).
    NoSharedDelay                = bitLShift(1, 17) -- IsItemHovered() only: Disable shared delay system where moving from one item to the next keeps the previous timer for a short time (standard for tooltips with long delays)
}

-- Flags for ImGui.IsWindowFocused()
--- @enum ImGuiFocusedFlags
ImGuiFocusedFlags = {
    None             = 0,
    ChildWindows     = bitLShift(1, 0), -- Return true if any children of the window is focused
    RootWindow       = bitLShift(1, 1), -- Test from root window (top most parent of the current hierarchy)
    AnyWindow        = bitLShift(1, 2), -- Return true if any window is focused. Important: If you are trying to tell how to dispatch your low-level inputs, do NOT use this. Use 'io.WantCaptureMouse' instead! Please read the FAQ!
    NoPopupHierarchy = bitLShift(1, 3), -- Do not consider popup hierarchy (do not treat popup emitter as parent of popup) (when used with _ChildWindows or _RootWindow)
    DockHierarchy    = bitLShift(1, 4), -- Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
}
ImGuiFocusedFlags.RootAndChildWindows = bitOr(ImGuiFocusedFlags.RootWindow, ImGuiFocusedFlags.ChildWindows)

ImGuiHoveredFlags.AllowWhenOverlapped = bitOr(ImGuiHoveredFlags.AllowWhenOverlappedByItem, ImGuiHoveredFlags.AllowWhenOverlappedByWindow)
ImGuiHoveredFlags.RectOnly            = bitOr(ImGuiHoveredFlags.AllowWhenBlockedByPopup, ImGuiHoveredFlags.AllowWhenBlockedByActiveItem, ImGuiHoveredFlags.AllowWhenOverlapped)
ImGuiHoveredFlags.RootAndChildWindows = bitOr(ImGuiHoveredFlags.RootWindow, ImGuiHoveredFlags.ChildWindows)
ImGuiHoveredFlags.DelayMask_ = bitOr(ImGuiHoveredFlags.DelayNone, ImGuiHoveredFlags.DelayShort, ImGuiHoveredFlags.DelayNormal, ImGuiHoveredFlags.NoSharedDelay)
ImGuiHoveredFlags.AllowedMaskForIsWindowHovered = bitOr(ImGuiHoveredFlags.ChildWindows, ImGuiHoveredFlags.RootWindow, ImGuiHoveredFlags.AnyWindow, ImGuiHoveredFlags.NoPopupHierarchy, ImGuiHoveredFlags.DockHierarchy, ImGuiHoveredFlags.AllowWhenBlockedByPopup, ImGuiHoveredFlags.AllowWhenBlockedByActiveItem, ImGuiHoveredFlags.ForTooltip, ImGuiHoveredFlags.Stationary)
ImGuiHoveredFlags.AllowedMaskForIsItemHovered = bitOr(ImGuiHoveredFlags.AllowWhenBlockedByPopup, ImGuiHoveredFlags.AllowWhenBlockedByActiveItem, ImGuiHoveredFlags.AllowWhenOverlapped, ImGuiHoveredFlags.AllowWhenDisabled, ImGuiHoveredFlags.NoNavOverride, ImGuiHoveredFlags.ForTooltip, ImGuiHoveredFlags.Stationary, ImGuiHoveredFlags.DelayMask_)

-- A key identifier (ImGuiKey.XXX or ImGuiMod_XXX value): can represent Keyboard, Mouse and Gamepad values.
-- All our named keys are >= 512. Keys value 0 to 511 are left unused and were legacy native/opaque key values (< 1.87).
-- Support for legacy keys was completely removed in 1.91.5.
-- Read details about the 1.87+ transition : https://github.com/ocornut/imgui/issues/4921
-- Note that "Keys" related to physical keys and are not the same concept as input "Characters", the latter are submitted via io.AddInputCharacter().
-- The keyboard key enum values are named after the keys on a standard US keyboard, and on other keyboard types the keys reported may not match the keycaps.
--- @enum ImGuiKey
ImGuiKey = {
    -- Keyboard
    None = 0,

    NamedKey_BEGIN = 512, -- First valid key value (other than 0)

    Tab        = 512, -- == ImGuiKey.NamedKey_BEGIN
    LeftArrow  = 513,
    RightArrow = 514,
    UpArrow    = 515,
    DownArrow  = 516,
    PageUp     = 517,
    PageDown   = 518,
    Home       = 519,
    End        = 520,
    Insert     = 521,
    Delete     = 522,
    Backspace  = 523,
    Space      = 524,
    Enter      = 525,
    Escape     = 526,
    LeftCtrl   = 527, LeftShift  = 528, LeftAlt  = 529, LeftSuper  = 530,
    RightCtrl  = 531, RightShift = 532, RightAlt = 533, RightSuper = 534,
    Menu       = 535,

    -- 1 ~ 9
    K0 = 536, K1 = 537, K2 = 538, K3 = 539, K4 = 540, K5 = 541, K6 = 542, K7 = 543, K8 = 544, K9 = 545,

    A = 546, B = 547, C = 548, D = 549, E = 550, F = 551, G = 552, H = 553, I = 554, J = 555,
    K = 556, L = 557, M = 558, N = 559, O = 560, P = 561, Q = 562, R = 563, S = 564, T = 565,
    U = 566, V = 567, W = 568, X = 569, Y = 570, Z = 571,

    F1  = 572, F2  = 573, F3  = 574, F4  = 575, F5  = 576, F6  = 577,
    F7  = 578, F8  = 579, F9  = 580, F10 = 581, F11 = 582, F12 = 583,
    F13 = 584, F14 = 585, F15 = 586, F16 = 587, F17 = 588, F18 = 589,
    F19 = 590, F20 = 591, F21 = 592, F22 = 593, F23 = 594, F24 = 595,

    Apostrophe = 596, Comma      = 597, Minus   = 598, Period      = 599, Slash = 600, Semicolon = 601, Equal = 602, LeftBracket = 603, Backslash = 604, RightBracket = 605, GraveAccent = 606,
    CapsLock   = 607, ScrollLock = 608, NumLock = 609, PrintScreen = 610, Pause = 611,

    Keypad0       = 612, Keypad1      = 613, Keypad2        = 614, Keypad3        = 615, Keypad4   = 616, Keypad5     = 617, Keypad6     = 618, Keypad7 = 619, Keypad8 = 620, Keypad9 = 621,
    KeypadDecimal = 622, KeypadDivide = 623, KeypadMultiply = 624, KeypadSubtract = 625, KeypadAdd = 626, KeypadEnter = 627, KeypadEqual = 628,

    AppBack        = 629, -- Available on some keyboard/mouses. Often referred as "Browser Back"
    AppForward     = 630,
    Oem102         = 631, -- Non-US backslash.

    -- Gamepad
    -- (analog values are 0.0f to 1.0f)
    -- (download controller mapping PNG/PSD at http://dearimgui.com/controls_sheets)
    -- XBOX        | SWITCH  | PLAYSTA. | -> ACTION
    GamepadStart      = 632, GamepadBack        = 633,
    GamepadFaceLeft   = 634, GamepadFaceRight   = 635, GamepadFaceUp   = 636, GamepadFaceDown   = 637,
    GamepadDpadLeft   = 638, GamepadDpadRight   = 639, GamepadDpadUp   = 640, GamepadDpadDown   = 641,
    GamepadL1         = 642, GamepadR1          = 643,
    GamepadL2         = 644, GamepadR2          = 645,
    GamepadL3         = 646, GamepadR3          = 647,
    GamepadLStickLeft = 648, GamepadLStickRight = 649, GamepadLStickUp = 650, GamepadLStickDown = 651,
    GamepadRStickLeft = 652, GamepadRStickRight = 653, GamepadRStickUp = 654, GamepadRStickDown = 655,

    MouseLeft = 656, MouseRight = 657, MouseMiddle = 658, MouseX1 = 659, MouseX2 = 660, MouseWheelX = 661, MouseWheelY = 662,

    ReservedForModCtrl = 663, ReservedForModShift = 664, ReservedForModAlt = 665, ReservedForModSuper = 666,

    -- [Internal] If you need to iterate all keys (for e.g. an input mapper) you may use ImGuiKey.NamedKey_BEGIN..ImGuiKey.NamedKey_END.
    NamedKey_END = 667
}

ImGuiKey.NamedKey_COUNT = ImGuiKey.NamedKey_END - ImGuiKey.NamedKey_BEGIN

-- Keyboard Modifiers (explicitly submitted by backend via AddKeyEvent() calls)
-- - Any functions taking a ImGuiKeyChord parameter can binary-or those with regular keys, e.g. Shortcut(ImGuiMod_Ctrl | ImGuiKey.S).
-- - Those are written back into io.KeyCtrl, io.KeyShift, io.KeyAlt, io.KeySuper for convenience,
--   but may be accessed via standard key API such as IsKeyPressed(), IsKeyReleased(), querying duration etc.
-- - Code polling every key (e.g. an interface to detect a key press for input mapping) might want to ignore those
--   and prefer using the real keys (e.g. ImGuiKey.LeftCtrl, ImGuiKey.RightCtrl instead of ImGuiMod_Ctrl).
-- - In theory the value of keyboard modifiers should be roughly equivalent to a logical or of the equivalent left/right keys.
--   In practice: it's complicated; mods are often provided from different sources. Keyboard layout, IME, sticky keys and
--   backends tend to interfere and break that equivalence. The safer decision is to relay that ambiguity down to the end-user...
-- - On macOS, we swap Cmd(Super) and Ctrl keys at the time of the io.AddKeyEvent() call.
ImGuiMod_None  = 0
ImGuiMod_Ctrl  = bitLShift(1, 12) -- Ctrl (non-macOS), Cmd (macOS)
ImGuiMod_Shift = bitLShift(1, 13) -- Shift
ImGuiMod_Alt   = bitLShift(1, 14) -- Option/Menu
ImGuiMod_Super = bitLShift(1, 15) -- Windows/Super (non-macOS), Ctrl (macOS)
ImGuiMod_Mask_ = 0xF000 -- 4-bits

-- Enumeration for PushStyleColor() / PopStyleColor()
--- @enum ImGuiCol
ImGuiCol = {
    Text                      = 0,
    TextDisabled              = 1,
    WindowBg                  = 2, -- Background of normal windows
    ChildBg                   = 3, -- Background of child windows
    PopupBg                   = 4, -- Background of popups, menus, tooltips windows
    Border                    = 5,
    BorderShadow              = 6,
    FrameBg                   = 7, -- Background of checkbox, radio button, plot, slider, text input
    FrameBgHovered            = 8,
    FrameBgActive             = 9,
    TitleBg                   = 10, -- Title bar
    TitleBgActive             = 11, -- Title bar when focused
    TitleBgCollapsed          = 12, -- Title bar when collapsed
    MenuBarBg                 = 13,
    ScrollbarBg               = 14,
    ScrollbarGrab             = 15,
    ScrollbarGrabHovered      = 16,
    ScrollbarGrabActive       = 17,
    CheckMark                 = 18, -- Checkbox tick and RadioButton circle
    CheckboxSelectedBg        = 19, -- Checkbox background when Selected, otherwise use FrameBg
    SliderGrab                = 20,
    SliderGrabActive          = 21,
    Button                    = 22,
    ButtonHovered             = 23,
    ButtonActive              = 24,
    Header                    = 25, -- Header* colors are used for CollapsingHeader, TreeNode, Selectable, MenuItem
    HeaderHovered             = 26,
    HeaderActive              = 27,
    Separator                 = 28,
    SeparatorHovered          = 29,
    SeparatorActive           = 30,
    ResizeGrip                = 31, -- Resize grip in lower-right and lower-left corners of windows.
    ResizeGripHovered         = 32,
    ResizeGripActive          = 33,
    InputTextCursor           = 34, -- InputText cursor/caret
    TabHovered                = 35, -- Tab background, when hovered
    Tab                       = 36, -- Tab background, when tab-bar is focused & tab is unselected
    TabSelected               = 37, -- Tab background, when tab-bar is focused & tab is selected
    TabSelectedOverline       = 38, -- Tab horizontal overline, when tab-bar is focused & tab is selected
    TabDimmed                 = 39, -- Tab background, when tab-bar is unfocused & tab is unselected
    TabDimmedSelected         = 40, -- Tab background, when tab-bar is unfocused & tab is selected
    TabDimmedSelectedOverline = 41, -- ..horizontal overline, when tab-bar is unfocused & tab is selected
    DockingPreview            = 42, -- Preview overlay color when about to docking something
    DockingEmptyBg            = 43, -- Background color for empty node (e.g. CentralNode with no window docked into it)
    PlotLines                 = 44,
    PlotLinesHovered          = 45,
    PlotHistogram             = 46,
    PlotHistogramHovered      = 47,
    TableHeaderBg             = 48, -- Table header background
    TableBorderStrong         = 49, -- Table outer and header borders (prefer using Alpha=1.0 here)
    TableBorderLight          = 50, -- Table inner borders (prefer using Alpha=1.0 here)
    TableRowBg                = 51, -- Table row background (even rows)
    TableRowBgAlt             = 52, -- Table row background (odd rows)
    TextLink                  = 53, -- Hyperlink color
    TextSelectedBg            = 54, -- Selected text inside an InputText
    TreeLines                 = 55, -- Tree node hierarchy outlines when using ImGuiTreeNodeFlags.DrawLines
    DragDropTarget            = 56, -- Rectangle border highlighting a drop target
    DragDropTargetBg          = 57, -- Rectangle background highlighting a drop target
    UnsavedMarker             = 58, -- Unsaved Document marker (in window title and tabs)
    NavCursor                 = 59, -- Color of keyboard/gamepad navigation cursor/rectangle, when visible
    NavWindowingHighlight     = 60, -- Highlight window when using Ctrl+Tab
    NavWindowingDimBg         = 61, -- Darken/colorize entire screen behind the Ctrl+Tab window list, when active
    ModalWindowDimBg          = 62, -- Darken/colorize entire screen behind a modal window, when one is active
    COUNT = 63
}

-- Backend capabilities flags stored in io.BackendFlags. Set by imgui_impl_xxx or custom backend.
--- @enum ImGuiBackendFlags
ImGuiBackendFlags = {
    None                  = 0,
    HasGamepad            = bitLShift(1, 0), -- Backend Platform supports gamepad and currently has one connected.
    HasMouseCursors       = bitLShift(1, 1), -- Backend Platform supports honoring GetMouseCursor() value to change the OS cursor shape.
    HasSetMousePos        = bitLShift(1, 2), -- Backend Platform supports io.WantSetMousePos requests to reposition the OS mouse position (only used if io.ConfigNavMoveSetMousePos is set).
    RendererHasVtxOffset  = bitLShift(1, 3), -- Backend Renderer supports ImDrawCmd::VtxOffset. This enables output of large meshes (64K+ vertices) while still using 16-bit indices.
    RendererHasTextures   = bitLShift(1, 4), -- Backend Renderer supports ImTextureData requests to create/update/destroy textures. This enables incremental texture updates and texture reloads. See https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md for instructions on how to upgrade your custom backend.

    -- [BETA] Multi-Viewports
    RendererHasViewports    = bitLShift(1, 10), -- Backend Renderer supports multiple viewports.
    PlatformHasViewports    = bitLShift(1, 11), -- Backend Platform supports multiple viewports.
    HasMouseHoveredViewport = bitLShift(1, 12), -- Backend Platform supports calling io.AddMouseViewportEvent() with the viewport under the mouse. IF POSSIBLE, ignore viewports with the ImGuiViewportFlags.NoInputs flag (Win32 backend, GLFW 3.30+ backend can do this, SDL backend cannot). If this cannot be done, Dear ImGui needs to use a flawed heuristic to find the viewport under.
    HasParentViewport       = bitLShift(1, 13) -- Backend Platform supports honoring viewport->ParentViewport/ParentViewportId value, by applying the corresponding parent/child relationship at the Platform level. Child windows always appear in front of their parent window.
}

-- Flags for ImGui.BeginDragDropSource(), ImGui.AcceptDragDropPayload()
--- @enum ImGuiDragDropFlags
ImGuiDragDropFlags = {
    None                     = 0,
    -- BeginDragDropSource() flags
    SourceNoPreviewTooltip   = bitLShift(1, 0), -- Disable preview tooltip. By default, a successful call to BeginDragDropSource opens a tooltip so you can display a preview or description of the source contents. This flag disables this behavior.
    SourceNoDisableHover     = bitLShift(1, 1), -- By default, when dragging we clear data so that IsItemHovered() will return false, to avoid subsequent user code submitting tooltips. This flag disables this behavior so you can still call IsItemHovered() on the source item.
    SourceNoHoldToOpenOthers = bitLShift(1, 2), -- Disable the behavior that allows to open tree nodes and collapsing header by holding over them while dragging a source item.
    SourceAllowNullID        = bitLShift(1, 3), -- Allow items such as Text(), Image() that have no unique identifier to be used as drag source, by manufacturing a temporary identifier based on their window-relative position. This is extremely unusual within the dear imgui ecosystem and so we made it explicit.
    SourceExtern             = bitLShift(1, 4), -- External source (from outside of dear imgui), won't attempt to read current item/window info. Will always return true. Only one Extern source can be active simultaneously.
    PayloadAutoExpire        = bitLShift(1, 5), -- Automatically expire the payload if the source cease to be submitted (otherwise payloads are persisting while being dragged)
    PayloadNoCrossContext    = bitLShift(1, 6), -- Hint to specify that the payload may not be copied outside current dear imgui context.
    PayloadNoCrossProcess    = bitLShift(1, 7), -- Hint to specify that the payload may not be copied outside current process.
    -- AcceptDragDropPayload() flags
    AcceptBeforeDelivery     = bitLShift(1, 10), -- AcceptDragDropPayload() will returns true even before the mouse button is released. You can then call IsDelivery() to test if the payload needs to be delivered.
    AcceptNoDrawDefaultRect  = bitLShift(1, 11), -- Do not draw the default highlight rectangle when hovering over target.
    AcceptNoPreviewTooltip   = bitLShift(1, 12), -- Request hiding the BeginDragDropSource tooltip from the BeginDragDropTarget site.
    AcceptDrawAsHovered      = bitLShift(1, 13) -- Accepting item will render as if hovered. Useful for e.g. a Button() used as a drop target.
}

ImGuiDragDropFlags.AcceptPeekOnly = bitOr(ImGuiDragDropFlags.AcceptBeforeDelivery, ImGuiDragDropFlags.AcceptNoDrawDefaultRect) -- For peeking ahead and inspecting the payload before delivery.

-- Helpers macros to generate 32-bit encoded colors
IM_COL32_R_SHIFT = 0
IM_COL32_G_SHIFT = 8
IM_COL32_B_SHIFT = 16
IM_COL32_A_SHIFT = 24
IM_COL32_A_MASK  = 0xFF000000

--- @param R ImU32
--- @param G ImU32
--- @param B ImU32
--- @param A ImU32
IM_COL32             = function(R, G, B, A) return (bitOr(bitLShift(A, IM_COL32_A_SHIFT), bitLShift(B, IM_COL32_B_SHIFT), bitLShift(G, IM_COL32_G_SHIFT), bitLShift(R, IM_COL32_R_SHIFT))) end
IM_COL32_WHITE       = IM_COL32(255, 255, 255, 255)
IM_COL32_BLACK       = IM_COL32(0, 0, 0, 255)
IM_COL32_BLACK_TRANS = IM_COL32(0, 0, 0, 0)

-- Flags for OpenPopup*(), BeginPopupContext*(), IsPopupOpen() functions.
-- - IMPORTANT: If you ever used the left mouse button with BeginPopupContextXXX() helpers before 1.92.6: Read "API BREAKING CHANGES" 2026/01/07 (1.92.6) entry in imgui.cpp or GitHub topic #9157.
-- - Multiple buttons currently cannot be combined/or-ed in those functions (we could allow it later).
--- @enum ImGuiPopupFlags
ImGuiPopupFlags = {
    None                    = 0,
    MouseButtonLeft         = bitLShift(1, 2), -- For BeginPopupContext*(): open on Left Mouse release. Only one button allowed!
    MouseButtonRight        = bitLShift(2, 2), -- For BeginPopupContext*(): open on Right Mouse release. Only one button allowed! (default)
    MouseButtonMiddle       = bitLShift(3, 2), -- For BeginPopupContext*(): open on Middle Mouse release. Only one button allowed!
    NoReopen                = bitLShift(1, 5), -- For OpenPopup*(), BeginPopupContext*(): don't reopen same popup if already open (won't reposition, won't reinitialize navigation)
    --ImGuiPopupFlags.NoReopenAlwaysNavInit = 1 << 6,   -- For OpenPopup*(), BeginPopupContext*(): focus and initialize navigation even when not reopening.
    NoOpenOverExistingPopup = bitLShift(1, 7), -- For OpenPopup*(), BeginPopupContext*(): don't open if there's already a popup at the same level of the popup stack
    NoOpenOverItems         = bitLShift(1, 8), -- For BeginPopupContextWindow(): don't return true when hovering items, only when hovering empty space
    AnyPopupId              = bitLShift(1, 10), -- For IsPopupOpen(): ignore the ImGuiID parameter and test for any popup.
    AnyPopupLevel           = bitLShift(1, 11) -- For IsPopupOpen(): search/test at any level of the popup stack (default test in the current level)
}

ImGuiPopupFlags.AnyPopup          = bitOr(ImGuiPopupFlags.AnyPopupId, ImGuiPopupFlags.AnyPopupLevel)
ImGuiPopupFlags.MouseButtonShift_ = 2 -- [Internal]
ImGuiPopupFlags.MouseButtonMask_  = 0x0C -- [Internal]
ImGuiPopupFlags.InvalidMask_      = 0x03 -- [Internal] Reserve legacy bits 0-1 to detect incorrectly passing 1 or 2 to the function.

-- Flags for ImGui.BeginCombo()
--- @enum ImGuiComboFlags
ImGuiComboFlags = {
    None            = 0,
    PopupAlignLeft  = bitLShift(1, 0), -- Align the popup toward the left by default
    HeightSmall     = bitLShift(1, 1), -- Max ~4 items visible. Tip: If you want your combo popup to be a specific size you can use SetNextWindowSizeConstraints() prior to calling BeginCombo()
    HeightRegular   = bitLShift(1, 2), -- Max ~8 items visible (default)
    HeightLarge     = bitLShift(1, 3), -- Max ~20 items visible
    HeightLargest   = bitLShift(1, 4), -- As many fitting items as possible
    NoArrowButton   = bitLShift(1, 5), -- Display on the preview box without the square arrow button
    NoPreview       = bitLShift(1, 6), -- Display only a square arrow button
    WidthFitPreview = bitLShift(1, 7) -- Width dynamically calculated from preview contents
}

ImGuiComboFlags.HeightMask_ = bitOr(ImGuiComboFlags.HeightSmall, ImGuiComboFlags.HeightRegular, ImGuiComboFlags.HeightLarge, ImGuiComboFlags.HeightLargest)
ImGuiComboFlags.CustomPreview = bitLShift(1, 20)

-- Flags for ImGui.Selectable()
--- @enum ImGuiSelectableFlags
ImGuiSelectableFlags = {
    None              = 0,
    NoAutoClosePopups = bitLShift(1, 0), -- Clicking this doesn't close parent popup window (overrides ImGuiItemFlags.AutoClosePopups)
    SpanAllColumns    = bitLShift(1, 1), -- Frame will span all columns of its container table (text will still fit in current column)
    AllowDoubleClick  = bitLShift(1, 2), -- Generate press events on double clicks too
    Disabled          = bitLShift(1, 3), -- Cannot be selected, display grayed out text
    AllowOverlap      = bitLShift(1, 4), -- Hit testing will allow subsequent widgets to overlap this one. Require previous frame HoveredId to match before being usable. Shortcut to calling SetNextItemAllowOverlap().
    Highlight         = bitLShift(1, 5), -- Make the item be displayed as if it is hovered
    SelectOnNav       = bitLShift(1, 6), -- Auto-select when moved into, unless Ctrl is held. Automatic when in a BeginMultiSelect() block.

    -- NB: need to be in sync with last value of ImGuiSelectableFlags_
    NoHoldingActiveID    = bitLShift(1, 20),
    SelectOnClick        = bitLShift(1, 22), -- Override button behavior to react on Click (default is Click+Release)
    SelectOnRelease      = bitLShift(1, 23), -- Override button behavior to react on Release (default is Click+Release)
    SpanAvailWidth       = bitLShift(1, 24), -- Span all avail width even if we declared less for layout purpose. FIXME: We may be able to remove this (added in 6251d379, 2bcafc86 for menus)
    SetNavIdOnHover      = bitLShift(1, 25), -- Set Nav/Focus ID on mouse hover (used by MenuItem)
    NoPadWithHalfSpacing = bitLShift(1, 26), -- Disable padding each side with ItemSpacing * 0.5f
    NoSetKeyOwner        = bitLShift(1, 27), -- Don't set key/input owner on the initial click (note: mouse buttons are keys! often, the key in question will be ImGuiKey.MouseLeft!)
}

-- Flags for ColorEdit3() / ColorEdit4() / ColorPicker3() / ColorPicker4() / ColorButton()
--- @enum ImGuiColorEditFlags
ImGuiColorEditFlags = {
    None           = 0,
    NoAlpha        = bitLShift(1, 1), -- ColorEdit, ColorPicker, ColorButton: ignore Alpha component (will only read 3 components from the input pointer).
    NoPicker       = bitLShift(1, 2), -- ColorEdit: disable picker when clicking on color square.
    NoOptions      = bitLShift(1, 3), -- ColorEdit: disable toggling options menu when right-clicking on inputs/small preview.
    NoSmallPreview = bitLShift(1, 4), -- ColorEdit, ColorPicker: disable color square preview next to the inputs. (e.g. to show only the inputs)
    NoInputs       = bitLShift(1, 5), -- ColorEdit, ColorPicker: disable inputs sliders/text widgets (e.g. to show only the small preview color square).
    NoTooltip      = bitLShift(1, 6), -- ColorEdit, ColorPicker, ColorButton: disable tooltip when hovering the preview.
    NoLabel        = bitLShift(1, 7), -- ColorEdit, ColorPicker: disable display of inline text label (the label is still forwarded to the tooltip and picker).
    NoSidePreview  = bitLShift(1, 8), -- ColorPicker: disable bigger color preview on right side of the picker, use small color square preview instead.
    NoDragDrop     = bitLShift(1, 9), -- ColorEdit: disable drag and drop target/source. ColorButton: disable drag and drop source.
    NoBorder       = bitLShift(1, 10), -- ColorButton: disable border (which is enforced by default)
    NoColorMarkers = bitLShift(1, 11), -- ColorEdit: disable rendering R/G/B/A color marker. May also be disabled globally by setting style.ColorMarkerSize = 0.

    -- Alpha preview
    AlphaOpaque      = bitLShift(1, 12), -- ColorEdit, ColorPicker, ColorButton: disable alpha in the preview,. Contrary to _NoAlpha it may still be edited when calling ColorEdit4()/ColorPicker4(). For ColorButton() this does the same as _NoAlpha.
    AlphaNoBg        = bitLShift(1, 13), -- ColorEdit, ColorPicker, ColorButton: disable rendering a checkerboard background behind transparent color.
    AlphaPreviewHalf = bitLShift(1, 14), -- ColorEdit, ColorPicker, ColorButton: display half opaque / half transparent preview.

    -- User Options (right-click on widget to change some of them)
    AlphaBar       = bitLShift(1, 18), -- ColorEdit, ColorPicker: show vertical alpha bar/gradient in picker.
    HDR            = bitLShift(1, 19), -- (WIP) ColorEdit: Currently only disable 0.0f..1.0f limits in RGBA edition (note: you probably want to use ImGuiColorEditFlags.Float flag as well).
    DisplayRGB     = bitLShift(1, 20), -- [Display]    -- ColorEdit: override _display_ type among RGB/HSV/Hex. ColorPicker: select any combination using one or more of RGB/HSV/Hex.
    DisplayHSV     = bitLShift(1, 21), -- [Display]    -- "
    DisplayHex     = bitLShift(1, 22), -- [Display]    -- "
    Uint8          = bitLShift(1, 23), -- [DataType]   -- ColorEdit, ColorPicker, ColorButton: _display_ values formatted as 0..255.
    Float          = bitLShift(1, 24), -- [DataType]   -- ColorEdit, ColorPicker, ColorButton: _display_ values formatted as 0.0f..1.0f floats instead of 0..255 integers. No round-trip of value via integers.
    PickerHueBar   = bitLShift(1, 25), -- [Picker]     -- ColorPicker: bar for Hue, rectangle for Sat/Value.
    PickerHueWheel = bitLShift(1, 26), -- [Picker]     -- ColorPicker: wheel for Hue, triangle for Sat/Value.
    PickerNoRotate = bitLShift(1, 27), -- [Picker]     -- ColorPicker: disable rotating Sat/Value triangle. Best set in io.ConfigColorEditFlags once.
    InputRGB       = bitLShift(1, 28), -- [Input]      -- ColorEdit, ColorPicker: input and output data in RGB format.
    InputHSV       = bitLShift(1, 29) -- [Input]      -- ColorEdit, ColorPicker: input and output data in HSV format.
}

-- Defaults Options copied to io.ConfigColorEditFlags during initialization.
-- The intent is that you probably don't want to override them in most of your calls.
-- Let the user choose via the option menu and/or modify io.ConfigColorEditFlags directly during startup if you want.
ImGuiColorEditFlags.DefaultOptions_ = bitOr(ImGuiColorEditFlags.Uint8, ImGuiColorEditFlags.DisplayRGB, ImGuiColorEditFlags.InputRGB, ImGuiColorEditFlags.PickerHueBar)
-- [Internal] Masks
ImGuiColorEditFlags.AlphaMask_ = bitOr( ImGuiColorEditFlags.NoAlpha, ImGuiColorEditFlags.AlphaOpaque, ImGuiColorEditFlags.AlphaNoBg, ImGuiColorEditFlags.AlphaPreviewHalf )
ImGuiColorEditFlags.DisplayMask_ = bitOr( ImGuiColorEditFlags.DisplayRGB, ImGuiColorEditFlags.DisplayHSV, ImGuiColorEditFlags.DisplayHex )
ImGuiColorEditFlags.DataTypeMask_ = bitOr( ImGuiColorEditFlags.Uint8, ImGuiColorEditFlags.Float )
ImGuiColorEditFlags.PickerMask_ = bitOr( ImGuiColorEditFlags.PickerHueWheel, ImGuiColorEditFlags.PickerHueBar )
ImGuiColorEditFlags.InputMask_ = bitOr( ImGuiColorEditFlags.InputRGB, ImGuiColorEditFlags.InputHSV )

-- Flags for DragFloat(), DragInt(), SliderFloat(), SliderInt() etc.
-- We use the same sets of flags for DragXXX() and SliderXXX() functions as the features are the same and it makes it easier to swap them.
-- (Those are per-item flags. There is shared behavior flag too: ImGuiIO: io.ConfigDragClickToInputText)
--- @enum ImGuiSliderFlags
ImGuiSliderFlags = {
    None            = 0,
    Logarithmic     = bitLShift(1, 5), -- Make the widget logarithmic (linear otherwise). Consider using ImGuiSliderFlags.NoRoundToFormat with this if using a format-string with small amount of digits.
    NoRoundToFormat = bitLShift(1, 6), -- Disable rounding underlying value to match precision of the display format string (e.g. %.3f values are rounded to those 3 digits).
    NoInput         = bitLShift(1, 7), -- Disable Ctrl+Click or Enter key allowing to input text directly into the widget.
    WrapAround      = bitLShift(1, 8), -- Enable wrapping around from max to min and from min to max. Only supported by DragXXX() functions for now.
    ClampOnInput    = bitLShift(1, 9), -- Clamp value to min/max bounds when input manually with Ctrl+Click. By default Ctrl+Click allows going out of bounds.
    ClampZeroRange  = bitLShift(1, 10), -- Clamp even if min==max==0.0f. Otherwise due to legacy reason DragXXX functions don't clamp with those values. When your clamping limits are dynamic you almost always want to use it.
    NoSpeedTweaks   = bitLShift(1, 11), -- Disable keyboard modifiers altering tweak speed. Useful if you want to alter tweak speed yourself based on your own logic.
    ColorMarkers    = bitLShift(1, 12), -- DragScalarN(), SliderScalarN(): Draw R/G/B/A color markers on each component.
    --ImGuiSliderFlags.LiveEditOnInput  = 1 << 13,      -- Shortcut to enable LiveEdit for this field.
    --ImGuiSliderFlags.NoLiveEditOnInput= 1 << 14,      -- Shortcut to disable LiveEdit for this field.
    InvalidMask_    = 0x7000000F, -- [Internal] We treat using those bits as being potentially a 'float power' argument from legacy API (obsoleted 2020-08) that has got miscast to this enum, and will trigger an assert if needed.
}

ImGuiSliderFlags.AlwaysClamp = bitOr(ImGuiSliderFlags.ClampOnInput, ImGuiSliderFlags.ClampZeroRange)

ImGuiSliderFlags.Vertical = bitLShift(1, 20) -- Should this slider be orientated vertically?
ImGuiSliderFlags.ReadOnly = bitLShift(1, 21) -- Consider using g.NextItemData.ItemFlags |= ImGuiItemFlags.ReadOnly instead.

-- [ALPHA] Rarely used / very advanced uses only. Use with SetNextWindowClass() and DockSpace() functions.
-- Important: the content of this class is still highly WIP and likely to change and be refactored
-- before we stabilize Docking features. Please be mindful if using this.
-- Provide hints:
-- - To the platform backend via altered viewport flags (enable/disable OS decoration, OS task bar icons, etc.)
-- - To the platform backend for OS level parent/child relationships of viewport (otherwise: default is configured via io.ConfigViewportsNoDefaultParent)
-- - To the docking system for various options and filtering.
--- @class ImGuiWindowClass
--- @field ClassId                    ImGuiID
--- @field ParentViewportId           ImGuiID
--- @field FocusRouteParentWindowId   ImGuiID
--- @field ViewportFlagsOverrideSet   ImGuiViewportFlags
--- @field ViewportFlagsOverrideClear ImGuiViewportFlags

--- @return ImGuiWindowClass
--- @nodiscard
function ImGuiWindowClass()
    return {
        ClassId                    = 0, -- User data. 0 = Default class (unclassed). Windows of different classes cannot be docked with each others.
        ParentViewportId           = 0xFFFFFFFF, -- Hint for the platform backend. -1: use default. 0: request platform backend to not parent the platform. != 0: request platform backend to create a parent<>child relationship between the platform windows. Not conforming backends are free to e.g. parent every viewport to the main viewport or not.
        FocusRouteParentWindowId   = 0, -- ID of parent window for shortcut focus route evaluation, e.g. Shortcut() call from Parent Window will succeed when this window is focused.
        ViewportFlagsOverrideSet   = 0, -- Viewport flags to set when a window of this class owns a viewport. This allows you to enforce OS decoration or task bar icon, override the defaults on a per-window basis.
        ViewportFlagsOverrideClear = 0, -- Viewport flags to clear when a window of this class owns a viewport. This allows you to enforce OS decoration or task bar icon, override the defaults on a per-window basis.

        TabItemFlagsOverrideSet  = 0, -- [EXPERIMENTAL] TabItem flags to set when a window of this class gets submitted into a dock node tab bar. May use with ImGuiTabItemFlags.Leading or ImGuiTabItemFlags.Trailing.
        DockNodeFlagsOverrideSet = 0, -- [EXPERIMENTAL] Dock node flags to set when a window of this class is hosted by a dock node (it doesn't have to be selected!)
        DockingAlwaysTabBar      = false, -- Set to true to enforce single floating windows of this class always having their own docking node (equivalent of setting the global io.ConfigDockingAlwaysTabBar)
        DockingAllowUnclassed    = true -- Set to true to allow windows of this class to be docked/merged with an unclassed window. -- FIXME-DOCK: Move to DockNodeFlags override?
    }
end

-- Flags for ImGui.InputText()
-- (Those are per-item flags. There are shared flags in ImGuiIO: io.ConfigInputTextCursorBlink and io.ConfigInputTextEnterKeepActive)
--- @enum ImGuiInputTextFlags
ImGuiInputTextFlags = {
    -- Basic filters (also see ImGuiInputTextFlags.CallbackCharFilter)
    None = 0,

    -- Basic filters (also see ImGuiInputTextFlags.CallbackCharFilter)
    CharsDecimal     = bitLShift(1, 0), -- Allow 0123456789.+-*/
    CharsHexadecimal = bitLShift(1, 1), -- Allow 0123456789ABCDEFabcdef
    CharsScientific  = bitLShift(1, 2), -- Allow 0123456789.+-*/eE (Scientific notation input)
    CharsUppercase   = bitLShift(1, 3), -- Turn a..z into A..Z
    CharsNoBlank     = bitLShift(1, 4), -- Filter out spaces, tabs

    -- Inputs
    AllowTabInput       = bitLShift(1, 5), -- Pressing TAB input a '\t' character into the text field
    EnterReturnsTrue    = bitLShift(1, 6), -- Return 'true' when Enter is pressed (as opposed to every time the value was modified). Consider disabling LiveEdit! or using IsItemDeactivatedAfterEdit() instead!
    EscapeClearsAll     = bitLShift(1, 7), -- Escape key clears content if not empty, and deactivate otherwise (contrast to default behavior of Escape to revert)
    CtrlEnterForNewLine = bitLShift(1, 8), -- In multi-line mode: validate with Enter, add new line with Ctrl+Enter (default is opposite: validate with Ctrl+Enter, add line with Enter). Note that Shift+Enter always enter a new line either way.

    -- Other options
    ReadOnly           = bitLShift(1, 9), -- Read-only mode
    Password           = bitLShift(1, 10), -- Password mode, display all characters as '*', disable copy
    AlwaysOverwrite    = bitLShift(1, 11), -- Overwrite mode
    AutoSelectAll      = bitLShift(1, 12), -- Select entire text when first taking mouse focus
    ParseEmptyRefVal   = bitLShift(1, 13), -- InputFloat(), InputInt(), InputScalar() etc. only: parse empty string as zero value.
    DisplayEmptyRefVal = bitLShift(1, 14), -- InputFloat(), InputInt(), InputScalar() etc. only: when value is zero, do not display it. Generally used with ImGuiInputTextFlags.ParseEmptyRefVal.
    NoHorizontalScroll = bitLShift(1, 15), -- Disable following the cursor horizontally
    NoUndoRedo         = bitLShift(1, 16), -- Disable undo/redo. Note that input text owns the text data while active, if you want to provide your own undo/redo stack you need e.g. to call ClearActiveID().

    -- Elide display / Alignment
    ElideLeft = bitLShift(1, 17), -- When text doesn't fit, elide left side to ensure right side stays visible. Useful for path/filenames. Single-line only!

    -- Callback features
    CallbackCompletion = bitLShift(1, 18), -- Callback on pressing TAB (for completion handling)
    CallbackHistory    = bitLShift(1, 19), -- Callback on pressing Up/Down arrows (for history handling)
    CallbackAlways     = bitLShift(1, 20), -- Callback on each iteration. User code may query cursor position, modify text buffer.
    CallbackCharFilter = bitLShift(1, 21), -- Callback on character inputs to replace or discard them. Modify 'EventChar' to replace or discard, or return 1 in callback to discard.
    CallbackResize     = bitLShift(1, 22), -- Callback on buffer capacity changes request (beyond 'buf_size' parameter value), allowing the string to grow. Notify when the string wants to be resized (for string types which hold a cache of their Size). You will be provided a new BufSize in the callback and NEED to honor it. (see misc/cpp/imgui_stdlib.h for an example of using this)
    CallbackEdit       = bitLShift(1, 23), -- Callback on any edit. Note that InputText() already returns true on edit + you can always use IsItemEdited(). The callback is useful to manipulate the underlying buffer while focus is active.

    -- Multi-line Word-Wrapping [BETA]
    WordWrap = bitLShift(1, 24), -- InputTextMultiline(): word-wrap lines that are too long.

    -- [Internal]
    Multiline            = bitLShift(1, 26), -- For internal use by InputTextMultiline()
    TempInput            = bitLShift(1, 27), -- For internal use by TempInputText(), will skip calling ItemAdd(). Require bounding-box to strictly match.
    LocalizeDecimalPoint = bitLShift(1, 28), -- For internal use by InputScalar() and TempInputScalar()
}

-------------------------------------------------------------------------------
-- [SECTION] Misc data structures (ImGuiInputTextCallbackData, ImGuiSizeCallbackData, ImGuiPayload)
-------------------------------------------------------------------------------

-- Shared state of InputText(), passed as an argument to your callback when a ImGuiInputTextFlags.Callback* flag is used.
-- The callback function should return 0 by default.
-- Callbacks (follow a flag name and see comments in ImGuiInputTextFlags_ declarations for more details)
-- - ImGuiInputTextFlags.CallbackEdit:        Callback on buffer edit. Note that InputText() already returns true on edit + you can always use IsItemEdited(). The callback is useful to manipulate the underlying buffer while focus is active.
-- - ImGuiInputTextFlags.CallbackAlways:      Callback on each iteration
-- - ImGuiInputTextFlags.CallbackCompletion:  Callback on pressing TAB
-- - ImGuiInputTextFlags.CallbackHistory:     Callback on pressing Up/Down arrows
-- - ImGuiInputTextFlags.CallbackCharFilter:  Callback on character inputs to replace or discard them. Modify 'EventChar' to replace or discard, or return 1 in callback to discard.
-- - ImGuiInputTextFlags.CallbackResize:      Callback on buffer capacity changes request (beyond 'buf_size' parameter value), allowing the string to grow.
--- @class ImGuiInputTextCallbackData

--- @return ImGuiInputTextCallbackData
-- Buf is a 1-based zero-terminated byte table; positions (CursorPos, pos...) are 0-based byte offsets like upstream.
MT.ImGuiInputTextCallbackData = {}
MT.ImGuiInputTextCallbackData.__index = MT.ImGuiInputTextCallbackData
function ImGuiInputTextCallbackData()
    return setmetatable({}, MT.ImGuiInputTextCallbackData)
end

function MT.ImGuiInputTextCallbackData:DeleteChars(pos, bytes_count)
    IM_ASSERT(pos + bytes_count <= self.BufTextLen)
    local buf = self.Buf
    local n = self.BufTextLen - bytes_count - pos + 1 -- includes zero terminator
    for i = 1, n do buf[pos + i] = buf[pos + bytes_count + i] end

    if self.CursorPos >= pos + bytes_count then
        self.CursorPos = self.CursorPos - bytes_count
    elseif self.CursorPos >= pos then
        self.CursorPos = pos
    end
    self.SelectionStart = self.CursorPos; self.SelectionEnd = self.CursorPos
    self.BufDirty = true
    self.BufTextLen = self.BufTextLen - bytes_count
end

--- @param new_text string
function MT.ImGuiInputTextCallbackData:InsertChars(pos, new_text)
    local new_text_len = #new_text
    if new_text_len == 0 then return end
    local is_resizable = bit32.band(self.Flags, ImGuiInputTextFlags.CallbackResize) ~= 0
    -- We support partial insertion
    local avail = self.BufSize - 1 - self.BufTextLen
    if not is_resizable and new_text_len > avail then
        new_text_len = avail -- ponytail: truncates by bytes, not to the closest UTF-8 codepoint
    end
    if new_text_len <= 0 then return end
    -- ponytail: CallbackResize buffer growth not supported, text is truncated at BufSize instead
    if self.BufTextLen + new_text_len + 1 > self.BufSize then
        new_text_len = self.BufSize - 1 - self.BufTextLen
        if new_text_len <= 0 then return end
    end

    local buf = self.Buf
    for i = self.BufTextLen, pos + 1, -1 do buf[i + new_text_len] = buf[i] end
    for i = 1, new_text_len do buf[pos + i] = string.byte(new_text, i) end
    buf[self.BufTextLen + new_text_len + 1] = 0

    self.BufDirty = true
    self.BufTextLen = self.BufTextLen + new_text_len
    if self.CursorPos >= pos then
        self.CursorPos = self.CursorPos + new_text_len
    end
    self.SelectionStart = self.CursorPos; self.SelectionEnd = self.CursorPos
end

function MT.ImGuiInputTextCallbackData:SelectAll() self.SelectionStart = 0; self.SelectionEnd = self.BufTextLen end
function MT.ImGuiInputTextCallbackData:ClearSelection() self.SelectionStart = self.BufTextLen; self.SelectionEnd = self.BufTextLen end
function MT.ImGuiInputTextCallbackData:HasSelection() return self.SelectionStart ~= self.SelectionEnd end

-- Callback and functions types
--- @alias ImGuiInputTextCallback fun(data: ImGuiInputTextCallbackData)

--- @alias ImGuiMemAllocFunc fun(T: function, start_idx: int, end_idx: int, userdata: any): table
--- @alias ImGuiMemFreeFunc fun(owner: table, field: string, userdata: any)

-- ImDrawCallback: Draw callbacks for advanced uses [configurable type: override in imconfig.h]
-- NB: You most likely do NOT need to use draw callbacks just to create your own widget or customized UI rendering,
-- you can poke into the draw list for that! Draw callback may be useful for example to:
--  A) Change your GPU render state,
--  B) render a complex 3D scene inside a UI element without an intermediate texture/render target, etc.
-- The expected behavior from your rendering function is 'if (cmd.UserCallback != nil) { cmd.UserCallback(parent_list, cmd); } else { RenderTriangles() }'
--- @alias ImDrawCallback fun(parent_list: ImDrawList, cmd: ImDrawCmd)

-- Flags for ImGui.TreeNodeEx(), ImGui.CollapsingHeader*()
--- @enum ImGuiTreeNodeFlags
ImGuiTreeNodeFlags = {
    None                 = 0,
    Selected             = bitLShift(1, 0), -- Draw as selected
    Framed               = bitLShift(1, 1), -- Draw frame with background (e.g. for CollapsingHeader)
    AllowOverlap         = bitLShift(1, 2), -- Hit testing will allow subsequent widgets to overlap this one. Require previous frame HoveredId to match before being usable. Shortcut to calling SetNextItemAllowOverlap().
    NoTreePushOnOpen     = bitLShift(1, 3), -- Don't do a TreePush() when open (e.g. for CollapsingHeader) = no extra indent nor pushing on ID stack
    NoAutoOpenOnLog      = bitLShift(1, 4), -- Don't automatically and temporarily open node when Logging is active (by default logging will automatically open tree nodes)
    DefaultOpen          = bitLShift(1, 5), -- Default node to be open
    OpenOnDoubleClick    = bitLShift(1, 6), -- Open on double-click instead of simple click (default for multi-select unless any _OpenOnXXX behavior is set explicitly). Both behaviors may be combined.
    OpenOnArrow          = bitLShift(1, 7), -- Open when clicking on the arrow part (default for multi-select unless any _OpenOnXXX behavior is set explicitly). Both behaviors may be combined.
    Leaf                 = bitLShift(1, 8), -- No collapsing, no arrow (use as a convenience for leaf nodes). Note: will always open a tree/id scope and return true. If you never use that scope, add ImGuiTreeNodeFlags.NoTreePushOnOpen.
    Bullet               = bitLShift(1, 9), -- Display a bullet instead of arrow. IMPORTANT: node can still be marked open/close if you don't set the _Leaf flag!
    FramePadding         = bitLShift(1, 10), -- Use FramePadding (even for an unframed text node) to vertically align text baseline to regular widget height. Equivalent to calling AlignTextToFramePadding() before the node.
    SpanAvailWidth       = bitLShift(1, 11), -- Extend hit box to the right-most edge, even if not framed. This is not the default in order to allow adding other items on the same line without using AllowOverlap mode.
    SpanFullWidth        = bitLShift(1, 12), -- Extend hit box to the left-most and right-most edges (cover the indent area).
    SpanLabelWidth       = bitLShift(1, 13), -- Narrow hit box + narrow hovering highlight, will only cover the label text.
    SpanAllColumns       = bitLShift(1, 14), -- Frame will span all columns of its container table (label will still fit in current column)
    LabelSpanAllColumns  = bitLShift(1, 15), -- Label will span all columns of its container table
    --ImGuiTreeNodeFlags.NoScrollOnOpen     = 1 << 16,  -- FIXME: TODO: Disable automatic scroll on TreePop() if node got just open and contents is not visible
    NavLeftJumpsToParent = bitLShift(1, 17), -- Nav: left arrow moves back to parent. This is processed in TreePop() when there's an unfulfilled Left nav request remaining.
    -- [EXPERIMENTAL] Draw lines connecting TreeNode hierarchy. Discuss in GitHub issue #2920.
    -- Default value is pulled from style.TreeLinesFlags. May be overridden in TreeNode calls.
    DrawLinesNone        = bitLShift(1, 18), -- No lines drawn
    DrawLinesFull        = bitLShift(1, 19), -- Horizontal lines to child nodes. Vertical line drawn down to TreePop() position: cover full contents. Faster (for large trees).
    DrawLinesToNodes     = bitLShift(1, 20), -- Horizontal lines to child nodes. Vertical line drawn down to bottom-most child node. Slower (for large trees).

    NoNavFocus                 = bitLShift(1, 27), -- Don't claim nav focus when interacting with this item (#8551)
    ClipLabelForTrailingButton = bitLShift(1, 28), -- FIXME-WIP: Hard-coded for CollapsingHeader()
    UpsideDownArrow            = bitLShift(1, 29), -- FIXME-WIP: Turn Down arrow into an Up arrow, for reversed trees (#6517)
}

ImGuiTreeNodeFlags.CollapsingHeader = bitOr(ImGuiTreeNodeFlags.Framed, ImGuiTreeNodeFlags.NoTreePushOnOpen, ImGuiTreeNodeFlags.NoAutoOpenOnLog)

ImGuiTreeNodeFlags.OpenOnMask_ = bitOr(ImGuiTreeNodeFlags.OpenOnDoubleClick, ImGuiTreeNodeFlags.OpenOnArrow)
ImGuiTreeNodeFlags.DrawLinesMask_ = bitOr(ImGuiTreeNodeFlags.DrawLinesNone, ImGuiTreeNodeFlags.DrawLinesFull, ImGuiTreeNodeFlags.DrawLinesToNodes)

-------------------------------------------------------------------------------
-- [SECTION] Tables API flags and structures (ImGuiTableFlags, ImGuiTableColumnFlags, ImGuiTableRowFlags, ImGuiTableBgTarget, ImGuiTableSortSpecs, ImGuiTableColumnSortSpecs)
-------------------------------------------------------------------------------

-- Flags for ImGui.BeginTable()
-- - Important! Sizing policies have complex and subtle side effects, much more so than you would expect.
--   Read comments/demos carefully + experiment with live demos to get acquainted with them.
-- - The DEFAULT sizing policies are:
--    - Default to ImGuiTableFlags.SizingFixedFit    if ScrollX is on, or if host window has ImGuiWindowFlags.AlwaysAutoResize.
--    - Default to ImGuiTableFlags.SizingStretchSame if ScrollX is off.
-- - When ScrollX is off:
--    - Table defaults to ImGuiTableFlags.SizingStretchSame -> all Columns defaults to ImGuiTableColumnFlags.WidthStretch with same weight.
--    - Columns sizing policy allowed: Stretch (default), Fixed/Auto.
--    - Fixed Columns (if any) will generally obtain their requested width (unless the table cannot fit them all).
--    - Stretch Columns will share the remaining width according to their respective weight.
--    - Mixed Fixed/Stretch columns is possible but has various side-effects on resizing behaviors.
--      The typical use of mixing sizing policies is: any number of LEADING Fixed columns, followed by one or two TRAILING Stretch columns.
--      (this is because the visible order of columns have subtle but necessary effects on how they react to manual resizing).
-- - When ScrollX is on:
--    - Table defaults to ImGuiTableFlags.SizingFixedFit -> all Columns defaults to ImGuiTableColumnFlags.WidthFixed
--    - Columns sizing policy allowed: Fixed/Auto mostly.
--    - Fixed Columns can be enlarged as needed. Table will show a horizontal scrollbar if needed.
--    - When using auto-resizing (non-resizable) fixed columns, querying the content width to use item right-alignment e.g. SetNextItemWidth(-FLT_MIN) doesn't make sense, would create a feedback loop.
--    - Using Stretch columns OFTEN DOES NOT MAKE SENSE if ScrollX is on, UNLESS you have specified a value for 'inner_width' in BeginTable().
--      If you specify a value for 'inner_width' then effectively the scrolling space is known and Stretch or mixed Fixed/Stretch columns become meaningful again.
-- - Read on documentation at the top of imgui_tables.cpp for details.
--- @enum ImGuiTableFlags
ImGuiTableFlags =
{
    -- Features
    None                       = 0,
    Resizable                  = bitLShift(1, 0), -- Enable resizing columns.
    Reorderable                = bitLShift(1, 1), -- Enable reordering columns in header row. (Need calling TableSetupColumn() + TableHeadersRow() to display headers, or using ImGuiTableFlags.ContextMenuInBody to access context-menu without headers).
    Hideable                   = bitLShift(1, 2), -- Enable hiding/disabling columns in context menu.
    Sortable                   = bitLShift(1, 3), -- Enable sorting. Call TableGetSortSpecs() to obtain sort specs. Also see ImGuiTableFlags.SortMulti and ImGuiTableFlags.SortTristate.
    NoSavedSettings            = bitLShift(1, 4), -- Disable persisting columns order, width, visibility and sort settings in the .ini file.
    ContextMenuInBody          = bitLShift(1, 5), -- Right-click on columns body/contents will also display table context menu. By default it is available in TableHeadersRow().
    -- Decorations
    RowBg                      = bitLShift(1, 6), -- Set each RowBg color with ImGuiCol.TableRowBg or ImGuiCol.TableRowBgAlt (equivalent of calling TableSetBgColor with ImGuiTableBgFlags.RowBg0 on each row manually)
    BordersInnerH              = bitLShift(1, 7), -- Draw horizontal borders between rows.
    BordersOuterH              = bitLShift(1, 8), -- Draw horizontal borders at the top and bottom.
    BordersInnerV              = bitLShift(1, 9), -- Draw vertical borders between columns.
    BordersOuterV              = bitLShift(1, 10), -- Draw vertical borders on the left and right sides.
    NoBordersInBody            = bitLShift(1, 11), -- [ALPHA] Disable vertical borders in columns Body (borders will always appear in Headers). -> May move to style
    NoBordersInBodyUntilResize = bitLShift(1, 12), -- [ALPHA] Disable vertical borders in columns Body until hovered for resize (borders will always appear in Headers). -> May move to style
    -- Sizing Policy (read above for defaults)
    SizingFixedFit             = bitLShift(1, 13), -- Columns default to _WidthFixed or _WidthAuto (if resizable or not resizable), matching contents width.
    SizingFixedSame            = bitLShift(2, 13), -- Columns default to _WidthFixed or _WidthAuto (if resizable or not resizable), matching the maximum contents width of all columns. Implicitly enable ImGuiTableFlags.NoKeepColumnsVisible.
    SizingStretchProp          = bitLShift(3, 13), -- Columns default to _WidthStretch with default weights proportional to each columns contents widths.
    SizingStretchSame          = bitLShift(4, 13), -- Columns default to _WidthStretch with default weights all equal, unless overridden by TableSetupColumn().
    -- Sizing Extra Options
    NoHostExtendX              = bitLShift(1, 16), -- Make outer width auto-fit to columns, overriding outer_size.x value. Only available when ScrollX/ScrollY are disabled and Stretch columns are not used.
    NoHostExtendY              = bitLShift(1, 17), -- Make outer height stop exactly at outer_size.y (prevent auto-extending table past the limit). Only available when ScrollX/ScrollY are disabled. Data below the limit will be clipped and not visible.
    NoKeepColumnsVisible       = bitLShift(1, 18), -- Disable keeping column always minimally visible when ScrollX is off and table gets too small. Not recommended if columns are resizable.
    PreciseWidths              = bitLShift(1, 19), -- Disable distributing remainder width to stretched columns (width allocation on a 100-wide table with 3 columns: Without this flag: 33,33,34. With this flag: 33,33,33). With larger number of columns, resizing will appear to be less smooth.
    -- Clipping
    NoClip                     = bitLShift(1, 20), -- Disable clipping rectangle for every individual columns (reduce draw command count, items will be able to overflow into other columns). Generally incompatible with TableSetupScrollFreeze().
    -- Padding
    PadOuterX                  = bitLShift(1, 21), -- Default if BordersOuterV is on. Enable outermost padding. Generally desirable if you have headers.
    NoPadOuterX                = bitLShift(1, 22), -- Default if BordersOuterV is off. Disable outermost padding.
    NoPadInnerX                = bitLShift(1, 23), -- Disable inner padding between columns (double inner padding if BordersOuterV is on, single inner padding if BordersOuterV is off).
    -- Scrolling
    ScrollX                    = bitLShift(1, 24), -- Enable horizontal scrolling. Require 'outer_size' parameter of BeginTable() to specify the container size. Changes default sizing policy. Because this creates a child window, ScrollY is currently generally recommended when using ScrollX.
    ScrollY                    = bitLShift(1, 25), -- Enable vertical scrolling. Require 'outer_size' parameter of BeginTable() to specify the container size.
    -- Sorting
    SortMulti                  = bitLShift(1, 26), -- Hold shift when clicking headers to sort on multiple column. TableGetSortSpecs() may return specs where (SpecsCount > 1).
    SortTristate               = bitLShift(1, 27), -- Allow no sorting, disable default sorting. TableGetSortSpecs() may return specs where (SpecsCount == 0).
    -- Miscellaneous
    HighlightHoveredColumn     = bitLShift(1, 28), -- Highlight column headers when hovered (may evolve into a fuller highlight)
}
ImGuiTableFlags.BordersH     = bitOr(ImGuiTableFlags.BordersInnerH, ImGuiTableFlags.BordersOuterH) -- Draw horizontal borders.
ImGuiTableFlags.BordersV     = bitOr(ImGuiTableFlags.BordersInnerV, ImGuiTableFlags.BordersOuterV) -- Draw vertical borders.
ImGuiTableFlags.BordersInner = bitOr(ImGuiTableFlags.BordersInnerV, ImGuiTableFlags.BordersInnerH) -- Draw inner borders.
ImGuiTableFlags.BordersOuter = bitOr(ImGuiTableFlags.BordersOuterV, ImGuiTableFlags.BordersOuterH) -- Draw outer borders.
ImGuiTableFlags.Borders      = bitOr(ImGuiTableFlags.BordersInner, ImGuiTableFlags.BordersOuter) -- Draw all borders.
-- [Internal] Combinations and masks
ImGuiTableFlags.SizingMask_  = bitOr(ImGuiTableFlags.SizingFixedFit, ImGuiTableFlags.SizingFixedSame, ImGuiTableFlags.SizingStretchProp, ImGuiTableFlags.SizingStretchSame)

-- Flags for ImGui.TableSetupColumn()
--- @enum ImGuiTableColumnFlags
ImGuiTableColumnFlags =
{
    -- Input configuration flags
    None                 = 0,
    Disabled             = bitLShift(1, 0), -- Overriding/master disable flag: hide column, won't show in context menu (unlike calling TableSetColumnEnabled() which manipulates the user accessible state)
    DefaultHide          = bitLShift(1, 1), -- Default as a hidden/disabled column.
    DefaultSort          = bitLShift(1, 2), -- Default as a sorting column.
    WidthStretch         = bitLShift(1, 3), -- Column will stretch. Preferable with horizontal scrolling disabled (default if table sizing policy is _SizingStretchSame or _SizingStretchProp).
    WidthFixed           = bitLShift(1, 4), -- Column will not stretch. Preferable with horizontal scrolling enabled (default if table sizing policy is _SizingFixedFit and table is resizable).
    NoResize             = bitLShift(1, 5), -- Disable manual resizing.
    NoReorder            = bitLShift(1, 6), -- Disable manual reordering this column, this will also prevent other columns from crossing over this column.
    NoHide               = bitLShift(1, 7), -- Disable ability to hide/disable this column.
    NoClip               = bitLShift(1, 8), -- Disable clipping for this column (all NoClip columns will render in a same draw command).
    NoSort               = bitLShift(1, 9), -- Disable ability to sort on this field (even if ImGuiTableFlags.Sortable is set on the table).
    NoSortAscending      = bitLShift(1, 10), -- Disable ability to sort in the ascending direction.
    NoSortDescending     = bitLShift(1, 11), -- Disable ability to sort in the descending direction.
    NoHeaderLabel        = bitLShift(1, 12), -- TableHeadersRow() will submit an empty label for this column. Convenient for some small columns. Name will still appear in context menu or in angled headers. You may append into this cell by calling TableSetColumnIndex() right after the TableHeadersRow() call.
    NoHeaderWidth        = bitLShift(1, 13), -- Disable header text width contribution to automatic column width.
    PreferSortAscending  = bitLShift(1, 14), -- Make the initial sort direction Ascending when first sorting on this column (default).
    PreferSortDescending = bitLShift(1, 15), -- Make the initial sort direction Descending when first sorting on this column.
    IndentEnable         = bitLShift(1, 16), -- Use current Indent value when entering cell (default for column 0).
    IndentDisable        = bitLShift(1, 17), -- Ignore current Indent value when entering cell (default for columns > 0). Indentation changes _within_ the cell will still be honored.
    AngledHeader         = bitLShift(1, 18), -- TableHeadersRow() will submit an angled header row for this column. Note this will add an extra row.

    -- Output status flags, read-only via TableGetColumnFlags()
    IsEnabled            = bitLShift(1, 24), -- Status: is enabled == not hidden by user/api (referred to as "Hide" in _DefaultHide and _NoHide) flags.
    IsVisible            = bitLShift(1, 25), -- Status: is visible == is enabled AND not clipped by scrolling.
    IsSorted             = bitLShift(1, 26), -- Status: is currently part of the sort specs
    IsHovered            = bitLShift(1, 27), -- Status: is hovered by mouse

    NoDirectResize_      = bitLShift(1, 30), -- [Internal] Disable user resizing this column directly (it may however we resized indirectly from its left edge)
}
-- [Internal] Combinations and masks
ImGuiTableColumnFlags.WidthMask_  = bitOr(ImGuiTableColumnFlags.WidthStretch, ImGuiTableColumnFlags.WidthFixed)
ImGuiTableColumnFlags.IndentMask_ = bitOr(ImGuiTableColumnFlags.IndentEnable, ImGuiTableColumnFlags.IndentDisable)
ImGuiTableColumnFlags.StatusMask_ = bitOr(ImGuiTableColumnFlags.IsEnabled, ImGuiTableColumnFlags.IsVisible, ImGuiTableColumnFlags.IsSorted, ImGuiTableColumnFlags.IsHovered)

-- Flags for ImGui.TableNextRow()
-- - Headers: Identify header row (set default background color + width of its contents accounted differently for auto column width)
--- @enum ImGuiTableRowFlags
ImGuiTableRowFlags = { None = 0, Headers = bitLShift(1, 0) }

-- Enum for ImGui.TableSetBgColor()
-- Background colors are rendering in 3 layers:
--  - Layer 0: draw with RowBg0 color if set, otherwise draw with ColumnBg0 if set.
--  - Layer 1: draw with RowBg1 color if set, otherwise draw with ColumnBg1 if set.
--  - Layer 2: draw with CellBg color if set.
-- The purpose of the two row/columns layers is to let you decide if a background color change should override or blend with the existing color.
-- When using ImGuiTableFlags.RowBg on the table, each row has the RowBg0 color automatically set for odd/even rows.
-- If you set the color of RowBg0 target, your color will override the existing RowBg0 color.
-- If you set the color of RowBg1 or ColumnBg1 target, your color will blend over the RowBg0 color.
-- - RowBg0: Set row background color 0 (generally used for background, automatically set when ImGuiTableFlags.RowBg is used)
-- - RowBg1: Set row background color 1 (generally used for selection marking)
-- - CellBg: Set cell background color (top-most color)
--- @enum ImGuiTableBgTarget
ImGuiTableBgTarget = { None = 0, RowBg0 = 1, RowBg1 = 2, CellBg = 3 }

-- A sorting direction
-- - Ascending = 0->9, A->Z etc.
-- - Descending = 9->0, Z->A etc.
--- @enum ImGuiSortDirection
ImGuiSortDirection = { None = 0, Ascending = 1, Descending = 2 }



-- Data payload for Drag and Drop operations: AcceptDragDropPayload(), GetDragDropPayload()
--- @class ImGuiPayload
--- Drag and drop payload. `Data` is any Lua value (C++ stores raw bytes); `DataSize` kept for API parity.
local IM_PAYLOAD = {}
IM_PAYLOAD.__index = IM_PAYLOAD
function IM_PAYLOAD:Clear() ImGuiPayload_Clear(self) end
function IM_PAYLOAD:IsDataType(t) return ImGuiPayload_IsDataType(self, t) end
function IM_PAYLOAD:IsPreview() return self.Preview end
function IM_PAYLOAD:IsDelivery() return self.Delivery end
function ImGuiPayload()
    return setmetatable({ Data = nil, DataSize = 0, SourceId = 0, SourceParentId = 0, DataFrameCount = -1, DataType = "", Preview = false, Delivery = false }, IM_PAYLOAD)
end
function ImGuiPayload_Clear(p) p.SourceId = 0; p.SourceParentId = 0; p.Data = nil; p.DataSize = 0; p.DataType = ""; p.DataFrameCount = -1; p.Preview = false; p.Delivery = false end
function ImGuiPayload_IsDataType(p, t) return p.DataFrameCount ~= -1 and p.DataType == t end
function ImGuiPayload_IsPreview(p) return p.Preview end
function ImGuiPayload_IsDelivery(p) return p.Delivery end

-------------------------------------------------------------------------------
-- [SECTION] Helpers (ImGuiOnceUponAFrame, ImGuiTextFilter, ImGuiTextBuffer, ImGuiStorage, ImGuiListClipper, Math Operators, ImColor)
-------------------------------------------------------------------------------

-- Helper: Growable text buffer for logging/accumulating text
-- (this could be called 'ImGuiTextBuilder' / 'ImGuiStringBuilder')
--- @class ImGuiTextBuffer  # string builder: Buf is a list of string chunks
local ImGuiTextBufferMT = {}
ImGuiTextBufferMT.__index = ImGuiTextBufferMT
function ImGuiTextBuffer() return setmetatable({ Buf = {} }, ImGuiTextBufferMT) end
function ImGuiTextBufferMT:clear() self.Buf = {} end
function ImGuiTextBufferMT:empty() return #self.Buf == 0 end
function ImGuiTextBufferMT:append(str) self.Buf[#self.Buf + 1] = str end
function ImGuiTextBufferMT:appendf(fmt, ...) self.Buf[#self.Buf + 1] = string.format(fmt, ...) end
function ImGuiTextBufferMT:c_str() return table.concat(self.Buf) end
function ImGuiTextBufferMT:size() return #self:c_str() end

--- @class ImGuiSettingsHandler
--- Fns take (ctx, handler, ...) like upstream. ReadOpenFn(ctx, handler, name) returns entry; ReadLineFn(ctx, handler, entry, line);
--- WriteAllFn(ctx, handler, buf: ImGuiTextBuffer)
function ImGuiSettingsHandler()
    return { TypeName = nil, TypeHash = 0, ClearAllFn = nil, ReadInitFn = nil, ReadOpenFn = nil, ReadLineFn = nil,
             ApplyAllFn = nil, WriteAllFn = nil, CleanupFn = nil, UserData = nil }
end

return true -- [Roblox] ModuleScripts must return exactly one value
end

__FILES['imgui_impl_love.lua'] = function()
--- Dear ImGui backend for LÖVE (11.x, LuaJIT). Platform (input, clipboard, cursors, IME) + renderer (Mesh per draw list).
--- Built into build/imgui_love.lua by `python3 tools/bundle.py --target love`.
--- Usage (see examples/example_love/main.lua):
---   love.load:  ImGui.CreateContext(); ImGui_ImplLove.Init({ root = "<repo root>/" })
---   love.update: ImGui_ImplLove.NewFrame(); ImGui.NewFrame(); ...your UI...; ImGui.Render()
---   love.draw:  ImGui_ImplLove.RenderDrawData(ImGui.GetDrawData())
---   forward love.mousemoved/mousepressed/mousereleased/wheelmoved/keypressed/keyreleased/textinput to ImGui_ImplLove.*

-- [SECTION] COMPAT (Luau stdlib for LuaJIT). tools/bundle.py --target love runs this section before the library.
--@compat-begin
local ffi = require("ffi")
local floor = math.floor
-- Luau standard library pieces the port uses, for LuaJIT (LÖVE). Prepended by `tools/bundle.py --target love` only:
-- the Roblox build uses Luau's native bit32/buffer/table/utf8 and never sees this file.

local bit = require("bit")
local TWO32 = 4294967296

-- bit32: unsigned 32-bit results like Luau/Lua 5.2 (LuaJIT's `bit` returns signed values)
if not bit32 then
    local band, bor, bxor, bnot, lshift, rshift, arshift, tobit = bit.band, bit.bor, bit.bxor, bit.bnot, bit.lshift, bit.rshift, bit.arshift, bit.tobit
    local function u(x) return x % TWO32 end
    local function t(x) return tobit(x % TWO32) end -- any number -> int32 (bit.* wraps doubles >= 2^31 unreliably)
    bit32 = {}
    function bit32.band(a, b, ...)
        if a == nil then return TWO32 - 1 end
        if b == nil then return u(t(a)) end
        local r = band(t(a), t(b))
        if ... ~= nil then for i = 1, select("#", ...) do r = band(r, t((select(i, ...)))) end end
        return u(r)
    end
    function bit32.bor(a, b, ...)
        if a == nil then return 0 end
        if b == nil then return u(t(a)) end
        local r = bor(t(a), t(b))
        if ... ~= nil then for i = 1, select("#", ...) do r = bor(r, t((select(i, ...)))) end end
        return u(r)
    end
    function bit32.bxor(a, b, ...)
        if a == nil then return 0 end
        if b == nil then return u(t(a)) end
        local r = bxor(t(a), t(b))
        if ... ~= nil then for i = 1, select("#", ...) do r = bxor(r, t((select(i, ...)))) end end
        return u(r)
    end
    function bit32.bnot(a) return u(bnot(t(a))) end
    function bit32.lshift(a, n) if n >= 32 or n <= -32 then return 0 end if n < 0 then return u(rshift(t(a), -n)) end return u(lshift(t(a), n)) end
    function bit32.rshift(a, n) if n >= 32 or n <= -32 then return 0 end if n < 0 then return u(lshift(t(a), -n)) end return u(rshift(t(a), n)) end
    function bit32.arshift(a, n) if n >= 32 then n = 31 end return u(arshift(t(a), n)) end
    function bit32.btest(...) return bit32.band(...) ~= 0 end
    function bit32.extract(n, field, width) width = width or 1; return u(band(rshift(t(n), field), 2 ^ width - 1)) end
end

-- buffer: fixed-size byte buffers (subset used by the port), on FFI memory. Little-endian like Luau.
if not buffer then
    ffi.cdef("void *memmove(void *dst, const void *src, size_t n); void *memset(void *s, int c, size_t n);")
    local C = ffi.C
    local u8p, u32p, f64p = ffi.typeof("uint8_t*"), ffi.typeof("uint32_t*"), ffi.typeof("double*")
    buffer = {}
    function buffer.create(n)
        local mem = ffi.new("uint8_t[?]", math.max(n, 1)) -- zero-filled
        return { p = ffi.cast(u8p, mem), n = n, mem = mem }
    end
    function buffer.len(b) return b.n end
    function buffer.readu8(b, o) return b.p[o] end
    function buffer.writeu8(b, o, v) b.p[o] = v end
    function buffer.readu32(b, o) return ffi.cast(u32p, b.p + o)[0] end
    function buffer.writeu32(b, o, v) ffi.cast(u32p, b.p + o)[0] = v % TWO32 end
    function buffer.readf64(b, o) return ffi.cast(f64p, b.p + o)[0] end
    function buffer.writef64(b, o, v) ffi.cast(f64p, b.p + o)[0] = v end
    function buffer.readstring(b, o, n) return ffi.string(b.p + o, n) end
    function buffer.writestring(b, o, s, n) ffi.copy(b.p + o, s, n or #s) end
    function buffer.copy(dst, doff, src, soff, n)
        soff = soff or 0
        n = n or (src.n - soff)
        if n > 0 then C.memmove(dst.p + doff, src.p + soff, n) end
    end
    function buffer.fill(b, o, v, n) n = n or (b.n - o); if n > 0 then C.memset(b.p + o, v, n) end end
    function buffer.tostring(b) return ffi.string(b.p, b.n) end
    function buffer.fromstring(s) local b = buffer.create(#s); ffi.copy(b.p, s, #s); return b end
end

-- table / math / utf8 additions from Luau / Lua 5.3
do
    local ok, clear = pcall(require, "table.clear")
    table.clear = table.clear or (ok and clear) or function(t) for k in pairs(t) do t[k] = nil end end
    table.unpack = table.unpack or unpack
    table.find = table.find or function(t, v, init) for i = init or 1, #t do if t[i] == v then return i end end end
    table.move = table.move or function(a1, f, e, t, a2)
        a2 = a2 or a1
        if e >= f then
            if t > f or t > e or a1 ~= a2 then for i = 0, e - f do a2[t + i] = a1[f + i] end
            else for i = e - f, 0, -1 do a2[t + i] = a1[f + i] end end
        end
        return a2
    end
    math.pow = math.pow or function(a, b) return a ^ b end
end

if not utf8 then
    utf8 = { charpattern = "[\0-\x7F\xC2-\xFD][\x80-\xBF]*" }
    function utf8.char(...)
        local out = {}
        for i = 1, select("#", ...) do
            local c = select(i, ...)
            if c < 0x80 then out[#out + 1] = string.char(c)
            elseif c < 0x800 then out[#out + 1] = string.char(0xC0 + floor(c / 64), 0x80 + c % 64)
            elseif c < 0x10000 then out[#out + 1] = string.char(0xE0 + floor(c / 4096), 0x80 + floor(c / 64) % 64, 0x80 + c % 64)
            else out[#out + 1] = string.char(0xF0 + floor(c / 262144), 0x80 + floor(c / 4096) % 64, 0x80 + floor(c / 64) % 64, 0x80 + c % 64) end
        end
        return table.concat(out)
    end
    local function decode(s, i)
        local c = s:byte(i)
        if not c then return nil end
        if c < 0x80 then return c, 1 end
        if c < 0xE0 then return (c % 32) * 64 + s:byte(i + 1) % 64, 2 end
        if c < 0xF0 then return (c % 16) * 4096 + (s:byte(i + 1) % 64) * 64 + s:byte(i + 2) % 64, 3 end
        return (c % 8) * 262144 + (s:byte(i + 1) % 64) * 4096 + (s:byte(i + 2) % 64) * 64 + s:byte(i + 3) % 64, 4
    end
    function utf8.codes(s)
        local i = 1
        return function()
            if i > #s then return nil end
            local c, n = decode(s, i)
            local p = i; i = i + n
            return p, c
        end
    end
    function utf8.codepoint(s, i, j)
        i = i or 1; j = j or i
        local out = {}
        while i <= j do local c, n = decode(s, i); out[#out + 1] = c; i = i + n end
        return unpack(out)
    end
    function utf8.len(s) local n = 0; for _ in utf8.codes(s) do n = n + 1 end return n end
    function utf8.offset(s, n, i)
        i = i or (n >= 0 and 1 or #s + 1)
        if n > 0 then
            n = n - 1
            while n > 0 and i <= #s do i = i + 1; while i <= #s and s:byte(i) >= 0x80 and s:byte(i) < 0xC0 do i = i + 1 end; n = n - 1 end
            if n > 0 then return nil end
            return i
        end
        return i
    end
end
--@compat-end

local floor, min = math.floor, math.min

local ImGui_ImplLOVE_GetBackendData

local CURSOR_MAP = {
    [ImGuiMouseCursor.Arrow]      = "arrow",
    [ImGuiMouseCursor.TextInput]  = "ibeam",
    [ImGuiMouseCursor.ResizeAll]  = "sizeall",
    [ImGuiMouseCursor.ResizeNS]   = "sizens",
    [ImGuiMouseCursor.ResizeEW]   = "sizewe",
    [ImGuiMouseCursor.ResizeNESW] = "sizenesw",
    [ImGuiMouseCursor.ResizeNWSE] = "sizenwse",
    [ImGuiMouseCursor.Hand]       = "hand",
    [ImGuiMouseCursor.Wait]       = "wait",
    [ImGuiMouseCursor.Progress]   = "waitarrow",
    [ImGuiMouseCursor.NotAllowed] = "no",
}

local KEY_MAP = {
    ["return"]    = ImGuiKey.Enter,       ["escape"]    = ImGuiKey.Escape,
    ["backspace"] = ImGuiKey.Backspace,   ["tab"]       = ImGuiKey.Tab,
    ["space"]     = ImGuiKey.Space,       ["kpenter"]   = ImGuiKey.KeypadEnter,
    ["up"]        = ImGuiKey.UpArrow,     ["down"]      = ImGuiKey.DownArrow,
    ["left"]      = ImGuiKey.LeftArrow,   ["right"]     = ImGuiKey.RightArrow,
    ["home"]      = ImGuiKey.Home,        ["end"]       = ImGuiKey.End,
    ["pageup"]    = ImGuiKey.PageUp,      ["pagedown"]  = ImGuiKey.PageDown,
    ["insert"]    = ImGuiKey.Insert,      ["delete"]    = ImGuiKey.Delete,
    ["lctrl"]     = ImGuiKey.LeftCtrl,    ["rctrl"]     = ImGuiKey.RightCtrl,
    ["lshift"]    = ImGuiKey.LeftShift,   ["rshift"]    = ImGuiKey.RightShift,
    ["lalt"]      = ImGuiKey.LeftAlt,     ["ralt"]      = ImGuiKey.RightAlt,
    ["lgui"]      = ImGuiKey.LeftSuper,   ["rgui"]      = ImGuiKey.RightSuper,
    ["-"] = ImGuiKey.Minus, ["="] = ImGuiKey.Equal, ["["] = ImGuiKey.LeftBracket, ["]"] = ImGuiKey.RightBracket,
    [";"] = ImGuiKey.Semicolon, ["'"] = ImGuiKey.Apostrophe, [","] = ImGuiKey.Comma, ["."] = ImGuiKey.Period,
    ["/"] = ImGuiKey.Slash, ["\\"] = ImGuiKey.Backslash, ["`"] = ImGuiKey.GraveAccent,
}
for i = 0, 9 do KEY_MAP[tostring(i)] = ImGuiKey["K" .. i]; KEY_MAP["kp" .. i] = ImGuiKey["Keypad" .. i] end
for i = 1, 12 do KEY_MAP["f" .. i] = ImGuiKey["F" .. i] end
for c in ("abcdefghijklmnopqrstuvwxyz"):gmatch(".") do KEY_MAP[c] = ImGuiKey[c:upper()] end

local function UpdateKeyModifiers()
    local io = ImGui.GetIO()
    io:AddKeyEvent(ImGuiMod_Ctrl, love.keyboard.isDown("lctrl", "rctrl"))
    io:AddKeyEvent(ImGuiMod_Shift, love.keyboard.isDown("lshift", "rshift"))
    io:AddKeyEvent(ImGuiMod_Alt, love.keyboard.isDown("lalt", "ralt"))
    io:AddKeyEvent(ImGuiMod_Super, love.keyboard.isDown("lgui", "rgui"))
end

function ImGui_ImplLOVE_GetBackendData()
    return ImGui.GetCurrentContext() and ImGui.GetIO().BackendPlatformUserData or nil
end

local function UpdateMonitors(w, h)
    local platform_io = ImGui.GetPlatformIO()
    platform_io.Monitors:resize(0)
    local m = ImGuiPlatformMonitor()
    ImVec2_Copy(m.MainSize, ImVec2(w, h))
    ImVec2_Copy(m.WorkSize, ImVec2(w, h))
    platform_io.Monitors:push_back(m)
end

---------------------------------------------------------
-- PLATFORM DATA & CALLBACKS
---------------------------------------------------------

local function PlatformSetImeData(ctx, vp, data)
    if data.WantVisible or data.WantTextInput then
        love.keyboard.setTextInput(true, data.InputPos.x, data.InputPos.y, 1, data.InputLineHeight)
    else
        love.keyboard.setTextInput(false)
    end
end

local function PlatformSetClipboardText(ctx, text) love.system.setClipboardText(text) end
local function PlatformGetClipboardText(ctx) return love.system.getClipboardText() end
local function PlatformOpenInShell(ctx, path) return love.system.openURL(path) end

---------------------------------------------------------
-- FILE SYSTEM: love.filesystem (game folder), then io.open(<root> .. path) so fonts/ etc. load from the repo
---------------------------------------------------------

local function ReadFile(filename)
    local data = love.filesystem.getInfo(filename) and love.filesystem.read(filename)
    if data then return data end
    local bd = ImGui_ImplLOVE_GetBackendData()
    local f = io.open(((bd and bd.Root) or "") .. filename, "rb")
    if not f then return nil end
    data = f:read("*a"); f:close()
    return data
end

function ImStd.ImFileOpen(filename, mode)
    local data = ReadFile(filename)
    return data and { Data = data, Pos = 0 } or nil
end
function ImStd.ImFileClose(f) end
function ImStd.ImFileGetSize(f) return #f.Data end
function ImStd.ImFileRead(f, data, count)
    local s, pos = f.Data, f.Pos
    count = min(count, #s - pos)
    for i = 1, count do data[i] = string.byte(s, pos + i) end
    f.Pos = pos + count
    return count
end
function ImStd.ImFileLoadToMemory(filename, mode)
    local f = ImStd.ImFileOpen(filename, mode)
    if not f or #f.Data == 0 then return end
    local file_data = {}
    local size = ImStd.ImFileRead(f, file_data, #f.Data)
    return file_data, size
end

---------------------------------------------------------
-- TEXTURES
---------------------------------------------------------

local function CopyToImageData(tex, x, y, w, h)
    local img = love.image.newImageData(w, h, "rgba8")
    local dst = ffi.cast("uint8_t*", img:getFFIPointer())
    local bpp = tex.BytesPerPixel
    for row = 0, h - 1 do
        local src, base = tex:GetPixelsAt(x, y + row)
        local d = row * w * 4
        if bpp == 4 then
            for i = 0, w * 4 - 1 do dst[d + i] = src[base + i] end
        else -- Alpha8: white with alpha
            for i = 0, w - 1 do
                local o = d + i * 4
                dst[o], dst[o + 1], dst[o + 2], dst[o + 3] = 255, 255, 255, src[base + i]
            end
        end
    end
    return img
end

function ImGui_ImplLOVE_UpdateTexture(tex)
    local bd = ImGui_ImplLOVE_GetBackendData()
    if tex.Status == ImTextureStatus.WantCreate then
        local data = CopyToImageData(tex, 0, 0, tex.Width, tex.Height)
        local image = love.graphics.newImage(data)
        image:setFilter("nearest", "nearest")
        bd.TextureCount = bd.TextureCount + 1
        bd.Textures[bd.TextureCount] = image
        tex.BackendUserData = bd.TextureCount
        tex:SetTexID(bd.TextureCount)
        tex:SetStatus(ImTextureStatus.OK)
    elseif tex.Status == ImTextureStatus.WantUpdates then
        local image = bd.Textures[tex.BackendUserData]
        for _, r in tex.Updates:iter() do
            local data = CopyToImageData(tex, r.x, r.y, r.w, r.h)
            image:replacePixels(data, nil, 1, r.x, r.y, false)
            data:release()
        end
        tex:SetStatus(ImTextureStatus.OK)
    elseif tex.Status == ImTextureStatus.WantDestroy then
        local image = tex.BackendUserData and bd.Textures[tex.BackendUserData]
        if image then image:release(); bd.Textures[tex.BackendUserData] = nil end
        tex.BackendUserData = nil
        tex:SetTexID(ImTextureID_Invalid)
        tex:SetStatus(ImTextureStatus.Destroyed)
    end
end

--- User texture from RGBA8 pixels (a `buffer` of w*h*4 bytes, or a love ImageData). Returns an ImTextureRef.
function ImGui_ImplLOVE_CreateTexture(pixels, w, h)
    local bd = ImGui_ImplLOVE_GetBackendData()
    local data = pixels
    if type(pixels) == "table" and pixels.p then
        data = love.image.newImageData(w, h, "rgba8")
        ffi.copy(data:getFFIPointer(), pixels.p, w * h * 4)
    end
    bd.TextureCount = bd.TextureCount + 1
    bd.Textures[bd.TextureCount] = love.graphics.newImage(data)
    return ImTextureRef(bd.TextureCount)
end

function ImGui_ImplLOVE_DestroyTexture(tex_ref)
    local bd = ImGui_ImplLOVE_GetBackendData()
    local image = bd.Textures[tex_ref._TexID]
    if image then image:release(); bd.Textures[tex_ref._TexID] = nil end
end

---------------------------------------------------------
-- RENDERING: one streamed Mesh per draw list; vertices converted from the port's flat VtxBuffer (f64 x, y, u, v,
-- u32 col; 36 bytes) to LÖVE's float x, y, u, v + byte rgba (20 bytes); indices -> 0-based uint32 vertex map.
---------------------------------------------------------

ffi.cdef("typedef struct { float x, y, u, v; uint8_t r, g, b, a; } ImGuiLoveVertex;")
local VERTEX_FORMAT = { { "VertexPosition", "float", 2 }, { "VertexTexCoord", "float", 2 }, { "VertexColor", "byte", 4 } }
local vtx_ct, u32p, f64p = ffi.typeof("ImGuiLoveVertex*"), ffi.typeof("uint32_t*"), ffi.typeof("double*")

local function GetMesh(bd, draw_list, nvtx, nidx)
    local m = bd.Meshes[draw_list]
    if not m or m.VtxCap < nvtx or m.IdxCap < nidx then
        local vcap = math.max(nvtx, m and m.VtxCap * 2 or 256)
        local icap = math.max(nidx, m and m.IdxCap * 2 or 512)
        if m then m.Mesh:release() end
        m = {
            Mesh = love.graphics.newMesh(VERTEX_FORMAT, vcap, "triangles", "stream"),
            VtxData = love.data.newByteData(vcap * 20), IdxData = love.data.newByteData(icap * 4),
            VtxCap = vcap, IdxCap = icap,
        }
        bd.Meshes[draw_list] = m
    end
    m.Used = bd.FrameNo
    return m
end

function ImGui_ImplLOVE_RenderDrawData(draw_data)
    local bd = ImGui_ImplLOVE_GetBackendData()
    if draw_data.Textures ~= nil then
        for _, tex in draw_data.Textures:iter() do
            if tex.Status ~= ImTextureStatus.OK then ImGui_ImplLOVE_UpdateTexture(tex) end
        end
    end
    local fb_w, fb_h = draw_data.DisplaySize.x, draw_data.DisplaySize.y
    if fb_w <= 0 or fb_h <= 0 then return end
    bd.FrameNo = bd.FrameNo + 1

    love.graphics.push("all")
    love.graphics.setBlendMode("alpha", "alphamultiply")
    love.graphics.setColor(1, 1, 1, 1)
    local ox, oy = draw_data.DisplayPos.x, draw_data.DisplayPos.y
    love.graphics.translate(-ox, -oy)

    for _, draw_list in draw_data.CmdLists:iter() do
        local nvtx, nidx = draw_list.VtxBuffer.Size, draw_list.IdxBuffer.Size
        if nvtx > 0 and nidx > 0 then
            local m = GetMesh(bd, draw_list, nvtx, nidx)
            local base = draw_list.VtxBuffer.Buf.p
            local srcu = ffi.cast(u32p, base)
            local dst = ffi.cast(vtx_ct, m.VtxData:getFFIPointer())
            for i = 0, nvtx - 1 do
                local v, src = dst[i], ffi.cast(f64p, base + i * 36) -- 36-byte stride: cast per vertex
                v.x, v.y, v.u, v.v = src[0], src[1], src[2], src[3]
                local c = srcu[i * 9 + 8]
                v.r, v.g, v.b, v.a = c % 256, floor(c / 256) % 256, floor(c / 65536) % 256, floor(c / 16777216)
            end
            m.Mesh:setVertices(m.VtxData, 1, nvtx)

            -- vertex map: per command, 0-based vertex = VtxOffset + idx - 1 (port indices are 1-based)
            local map = ffi.cast(u32p, m.IdxData:getFFIPointer())
            local idx = draw_list.IdxBuffer.Data
            for _, pcmd in draw_list.CmdBuffer:iter() do
                local vo = pcmd.VtxOffset
                for i = pcmd.IdxOffset + 1, pcmd.IdxOffset + pcmd.ElemCount do map[i - 1] = vo + idx[i] - 1 end
            end
            m.Mesh:setVertexMap(m.IdxData, "uint32")

            for _, pcmd in draw_list.CmdBuffer:iter() do
                if pcmd.UserCallback ~= nil then
                    pcmd.UserCallback(draw_list, pcmd)
                elseif pcmd.ElemCount > 0 then
                    local c = pcmd.ClipRect
                    local x0, y0 = math.max(c.x - ox, 0), math.max(c.y - oy, 0)
                    local x1, y1 = min(c.z - ox, fb_w), min(c.w - oy, fb_h)
                    if x1 > x0 and y1 > y0 then
                        love.graphics.setScissor(x0, y0, x1 - x0, y1 - y0)
                        m.Mesh:setTexture(bd.Textures[pcmd:GetTexID()])
                        m.Mesh:setDrawRange(pcmd.IdxOffset + 1, pcmd.ElemCount)
                        love.graphics.draw(m.Mesh)
                    end
                end
            end
        end
    end

    -- free meshes of draw lists that went away
    for dl, m in pairs(bd.Meshes) do
        if bd.FrameNo - m.Used > 120 then m.Mesh:release(); bd.Meshes[dl] = nil end
    end
    love.graphics.setScissor()
    love.graphics.pop()
end

---------------------------------------------------------
-- LIFECYCLE
---------------------------------------------------------

--- opts.root: path prefix for files not in the LÖVE game folder (e.g. the repo root, for fonts/)
function ImGui_ImplLOVE_Init(opts)
    opts = opts or {}
    local io = ImGui.GetIO()
    local bd = { Time = love.timer.getTime(), Root = opts.root or "", Textures = {}, TextureCount = 0, Meshes = {}, FrameNo = 0 }
    io.BackendPlatformUserData = bd
    io.BackendFlags = bit32.bor(io.BackendFlags, ImGuiBackendFlags.RendererHasTextures, ImGuiBackendFlags.RendererHasVtxOffset, ImGuiBackendFlags.HasMouseCursors)

    local platform_io = ImGui.GetPlatformIO()
    platform_io.Platform_SetImeDataFn       = PlatformSetImeData
    platform_io.Platform_SetClipboardTextFn = PlatformSetClipboardText
    platform_io.Platform_GetClipboardTextFn = PlatformGetClipboardText
    platform_io.Platform_OpenInShellFn      = PlatformOpenInShell
    local w, h = love.graphics.getDimensions()
    UpdateMonitors(w, h)
    love.keyboard.setKeyRepeat(true)
end

function ImGui_ImplLOVE_Shutdown()
    local io = ImGui.GetIO()
    local bd = ImGui_ImplLOVE_GetBackendData()
    for _, m in pairs(bd.Meshes) do m.Mesh:release() end
    for _, t in pairs(bd.Textures) do t:release() end
    io.BackendPlatformUserData = nil
    io.BackendFlags = bit32.band(io.BackendFlags, bit32.bnot(bit32.bor(ImGuiBackendFlags.RendererHasTextures, ImGuiBackendFlags.RendererHasVtxOffset, ImGuiBackendFlags.HasMouseCursors)))
end

function ImGui_ImplLOVE_NewFrame()
    local io = ImGui.GetIO()
    local bd = ImGui_ImplLOVE_GetBackendData()

    local w, h = love.graphics.getDimensions()
    if w ~= bd.ScreenW or h ~= bd.ScreenH then bd.ScreenW, bd.ScreenH = w, h; UpdateMonitors(w, h) end
    ImVec2_CopyV(io.DisplaySize, w, h)

    local now = love.timer.getTime()
    io.DeltaTime = (now > bd.Time) and (now - bd.Time) or (1.0 / 60.0)
    bd.Time = now

    if bit32.band(io.ConfigFlags, ImGuiConfigFlags.NoMouseCursorChange) == 0 then
        local cursor = ImGui.GetMouseCursor()
        if cursor ~= bd.LastCursor then
            bd.LastCursor = cursor
            local name = CURSOR_MAP[cursor]
            love.mouse.setVisible(cursor ~= ImGuiMouseCursor.None and not io.MouseDrawCursor)
            love.mouse.setCursor(name and love.mouse.getSystemCursor(name) or nil)
        end
    end
end

---------------------------------------------------------
-- LÖVE EVENT HOOKS (forward from love.* callbacks)
---------------------------------------------------------

local MOUSE_BUTTONS = { [1] = 0, [2] = 1, [3] = 2, [4] = 3, [5] = 4 } -- LÖVE: 1 left, 2 right, 3 middle

local function MouseMoved(x, y)
    local io = ImGui.GetIO()
    io:AddMouseSourceEvent(ImGuiMouseSource.Mouse)
    io:AddMousePosEvent(x, y)
end
local function MousePressed(x, y, button)
    local b = MOUSE_BUTTONS[button]
    if b then local io = ImGui.GetIO(); io:AddMouseSourceEvent(ImGuiMouseSource.Mouse); io:AddMouseButtonEvent(b, true) end
end
local function MouseReleased(x, y, button)
    local b = MOUSE_BUTTONS[button]
    if b then ImGui.GetIO():AddMouseButtonEvent(b, false) end
end
local function WheelMoved(x, y) ImGui.GetIO():AddMouseWheelEvent(-x, y) end
local function KeyPressed(key)
    UpdateKeyModifiers()
    local k = KEY_MAP[key]
    if k then ImGui.GetIO():AddKeyEvent(k, true) end
end
local function KeyReleased(key)
    UpdateKeyModifiers()
    local k = KEY_MAP[key]
    if k then ImGui.GetIO():AddKeyEvent(k, false) end
end
local function TextInput(text)
    local io = ImGui.GetIO()
    for _, c in utf8.codes(text) do io:AddInputCharacter(c) end
end
local function Focus(f) ImGui.GetIO():AddFocusEvent(f) end

--- True when ImGui wants the mouse / keyboard (don't pass the event to your game)
local function WantCaptureMouse() return ImGui.GetIO().WantCaptureMouse end
local function WantCaptureKeyboard() return ImGui.GetIO().WantCaptureKeyboard end

ImGui_ImplLove = {
    Init           = ImGui_ImplLOVE_Init,
    Shutdown       = ImGui_ImplLOVE_Shutdown,
    NewFrame       = ImGui_ImplLOVE_NewFrame,
    RenderDrawData = ImGui_ImplLOVE_RenderDrawData,
    CreateTexture  = ImGui_ImplLOVE_CreateTexture,
    DestroyTexture = ImGui_ImplLOVE_DestroyTexture,
    MouseMoved     = MouseMoved,
    MousePressed   = MousePressed,
    MouseReleased  = MouseReleased,
    WheelMoved     = WheelMoved,
    KeyPressed     = KeyPressed,
    KeyReleased    = KeyReleased,
    TextInput      = TextInput,
    Focus          = Focus,
    WantCaptureMouse = WantCaptureMouse,
    WantCaptureKeyboard = WantCaptureKeyboard,
}

return true
end

__FILES['imgui_internal.lua'] = function()
-- dear imgui, v1.93.0 WIP
-- (internal structures/api)

-- You may use this file to debug, understand or extend Dear ImGui features but we don't provide any guarantee of forward compatibility.

-- Index of this file:
--
-- [SECTION] Context pointer
-- [SECTION] Macros
-- [SECTION] Generic helpers
-- [SECTION] ImDrawList support
-- [SECTION] Style support
-- [SECTION] Data types support
-- [SECTION] Widgets support: flags, enums, data structures
-- [SECTION] Popup support
-- [SECTION] Inputs support
-- [SECTION] Navigation support
-- [SECTION] Viewport support
-- [SECTION] Settings support
-- [SECTION] Localization support
-- [SECTION] Metrics, Debug tools
-- [SECTION] ImGuiContext (main imgui context)
-- [SECTION] ImGuiWindowTempData, ImGuiWindow
-- [SECTION] Tab bar, Tab item support
-- [SECTION] ImGui internal API
-- [SECTION] ImFontLoader
-- [SECTION] ImFontAtlas internal API
--
-- PORT: the order of declarations in this file does not strictly follow upstream's imgui_internal.h.

--- @meta

local type   = ImGui._GetTypeFunc()
local rawget = rawget

local mathMin   = math.min; local mathMax    = math.max
local mathFloor = math.floor; local mathCeil = math.ceil

local bitNot    = bit32.bnot
local bitAnd    = bit32.band; local bitOr       = bit32.bor
local bitLShift = bit32.lshift; local bitRShift = bit32.rshift

local t_sort = table.sort

--- @alias ImGuiTableColumnIdx ImS16

-- TODO: Implement actual ImString type
--- @alias ImString char[]|string
--- @alias ImStringBuffer char[]

-- NOTE: temporary solution
--- @param buf       char[]
--- @param buf_begin int
--- @param buf_end   int    # exclusive
function ImGui._ByteArrayToString(buf, buf_begin, buf_end)
    local str = {}
    for i = buf_begin, buf_end - 1 do
        table.insert(str, string.char(buf[i]))
    end
    return table.concat(str)
end


-- Helper: ImPool<>
-- Basic keyed storage for contiguous instances, slow/amortized insertion, O(1) indexable, O(Log N) queries by ID over a dense/hot buffer,
-- Indexes have the same lifetime as the associated object.
--- ImPool<T>: pool of objects keyed by ID. Public indices are 0-based like upstream (Buf is stored 1-based).
--- `ctor` creates a new element. Removed slots are recycled via FreeIdx (-1 = none; free slots chain through `_NextFree`).
local IM_POOL = {}
IM_POOL.__index = IM_POOL
function ImPool(ctor) return setmetatable({ Buf = {}, Map = {}, FreeIdx = 0, AliveCount = 0, BufSize = 0, _Ctor = ctor }, IM_POOL) end
function IM_POOL:GetByKey(key) local i = self.Map[key]; return i and self.Buf[i + 1] or nil end
function IM_POOL:GetByIndex(n) return self.Buf[n + 1] end
function IM_POOL:GetIndex(p) return p._PoolIdx end
function IM_POOL:Contains(p) return p ~= nil and self.Buf[(p._PoolIdx or -1) + 1] == p end
function IM_POOL:GetMapSize() return self.BufSize end
function IM_POOL:Clear() self.Buf = {}; self.Map = {}; self.FreeIdx = 0; self.AliveCount = 0; self.BufSize = 0 end
function IM_POOL:Add()
    local idx
    if self._Free and #self._Free > 0 then idx = table.remove(self._Free) else idx = self.BufSize; self.BufSize = self.BufSize + 1 end
    local p = self._Ctor and self._Ctor() or {}
    p._PoolIdx = idx
    self.Buf[idx + 1] = p
    self.AliveCount = self.AliveCount + 1
    return p
end
function IM_POOL:GetOrAddByKey(key)
    local i = self.Map[key]
    if i then return self.Buf[i + 1] end
    local p = self:Add(); self.Map[key] = p._PoolIdx; return p
end
function IM_POOL:Remove(key, p)
    if type(key) == "table" then p = key; key = nil end
    if key == nil then for k, i in pairs(self.Map) do if i == p._PoolIdx then key = k break end end end
    if key ~= nil then self.Map[key] = nil end
    self.Buf[p._PoolIdx + 1] = false
    self._Free = self._Free or {}
    table.insert(self._Free, p._PoolIdx)
    self.AliveCount = self.AliveCount - 1
end
function IM_POOL:Reserve(n) end
-- NOTE: removed slots hold `false`; iterate with `for i = 0, pool:GetMapSize() - 1 do local t = pool:GetByIndex(i) if t then ... end end`

-------------------------------------------------------------------------------
-- [SECTION] Context pointer
-- See implementation of this variable in imgui.cpp for comments and details.
-------------------------------------------------------------------------------

--- @type ImGuiContext?
local GImGui -- Current implicit context pointer

-- Sets local `GImGui` in this file(imgui_internal.lua).
-- This is currently only used in main code `ImGui.SetCurrentContext()`
--- @param ctx ImGuiContext?
function ImGui._SetCurrentContext_Internal(ctx)
    GImGui = ctx
end

local setmetatable = setmetatable

local MT = ImGui.GetMetatables()

-------------------------------------------------------------------------------
-- [SECTION] Macros
-------------------------------------------------------------------------------

IM_TABSIZE = 4

FLT_MIN = 1.1754943508223e-38
FLT_MAX = 3.4028234663853e+38
DBL_MAX = 1.7976931348623e+308
INT_MIN = -0x7fffffff - 1
INT_MAX = 0x7fffffff
UINT_MAX = 0x7fffffff * 2 + 1

NAV_WINDOWING_HIGHLIGHT_DELAY = 0.5 -- Time before the highlight and screen dimming starts fading in
NAV_ACTIVATE_HIGHLIGHT_TIMER = 0.10 -- Time to highlight an item activated by a shortcut.
NAV_ACTIVATE_INPUT_WITH_GAMEPAD_DELAY = 0.60 -- Time to hold activation button (e.g. FaceDown) to turn the activation into a text input.

IM_PI  = math.pi

-------------------------------------------------------------------------------
-- [SECTION] Generic helpers
-- Note that the ImXXX helpers functions are lower-level than ImGui functions.
-- ImGui functions or the ImGui context are never called/used from other ImXXX functions.
-------------------------------------------------------------------------------

-- Helpers: Maths
-- - Wrapper for standard libs functions. (Note that imgui_demo.cpp does _not_ use them to keep the code easy to copy)
ImPow  = math.pow -- DragBehaviorT/SliderBehaviorT uses ImPow with either float/double and need the precision
ImLog  = math.log -- DragBehaviorT/SliderBehaviorT uses ImLog with either float/double and need the precision
ImAbs  = math.abs
ImFabs = math.abs
ImFmod = function(a, b) if b < 0 then b = -b end; if a < 0 then return -(-a % b) else return a % b end; end

ImRound64 = function(val) return math.floor(val + 0.5) end -- FIXME: Positive values only

ImCeil  = math.ceil
ImSin   = math.sin
ImCos   = math.cos
ImAcos  = math.acos
ImAtan2 = math.atan2
ImSqrt  = math.sqrt

--- @generic T: number
--- @param a  T
--- @param b  T
--- @param mn T
--- @param mx T
--- @return T
function ImAddClampOverflow(a, b, mn, mx)
    if b < 0 and (a < mn - b) then return mn end
    if b > 0 and (a > mx - b) then return mx end
    return a + b
end

--- @generic T: number
--- @param a  T
--- @param b  T
--- @param mn T
--- @param mx T
--- @return T
function ImSubClampOverflow(a, b, mn, mx)
    if b > 0 and (a < mn + b) then return mn end
    if b < 0 and (a > mx + b) then return mx end
    return a - b
end

-- - ImMin/ImMax/ImClamp/ImLerp/ImSwap are used by widgets which support variety of types: signed/unsigned int/long long float/double
--- @overload fun(lhs: number, rhs: number): number
--- @overload fun(lhs: ImVec2, rhs: ImVec2): ImVec2

function ImMin(lhs, rhs)
    if type(lhs) == "number" then return mathMin(lhs, rhs) end
    return ImVec2(mathMin(lhs.x, rhs.x), mathMin(lhs.y, rhs.y))
end

--- @overload fun(lhs: number, rhs: number): number
--- @overload fun(lhs: ImVec2, rhs: ImVec2): ImVec2

function ImMax(lhs, rhs)
    if type(lhs) == "number" then return mathMax(lhs, rhs) end
    return ImVec2(mathMax(lhs.x, rhs.x), mathMax(lhs.y, rhs.y))
end

-- Helpers: Sorting
--- @param base     table
--- @param count    int
--- @param cmp_func fun(lhs, rhs): bool
ImStd.ImQsort = function(base, count, cmp_func) if count > 0 then t_sort(base, cmp_func) end end

--- @overload fun(v: number, mn: number, mx: number): number
--- @overload fun(v: ImVec2, mn: ImVec2, mx: ImVec2): ImVec2

function ImClamp(v, mn, mx)
    if     type(v) == "number" and type(mn) == "number" and type(mx) == "number" then return mathMin(mathMax(v, mn), mx)
    elseif type(v) == "table"  and type(mn) == "table"  and type(mx) == "table"  then return ImVec2(mathMax(mn.x, mathMin(v.x, mx.x)), mathMax(mn.y, mathMin(v.y, mx.y)))
    end
end

--- @overload fun(a: number, b: number, t: number): number
--- @overload fun(a: ImVec2, b: ImVec2, t: number): ImVec2
--- @overload fun(a: ImVec2, b: ImVec2, t: ImVec2): ImVec2

function ImLerp(a, b, t)
    if     type(a) == "number" and type(b) == "number" and type(t) == "number" then return ((a) + ((b) - (a)) * (t))
    elseif type(a) == "table"  and type(b) == "table"  and type(t) == "number" then return ImVec2(a.x + (b.x - a.x) * t, a.y + (b.y - a.y) * t)
    elseif type(a) == "table"  and type(b) == "table"  and type(t) == "table"  then return ImVec2(a.x + (b.x - a.x) * t.x, a.y + (b.y - a.y) * t.y)
    end
end

local function _Trunc(val) if val >= 0 then return mathFloor(val) else return mathCeil(val) end end

--- @overload fun(v: float): float
--- @overload fun(v: ImVec2): ImVec2
function ImTrunc(v)
    if     type(v) == "number" then return _Trunc(v)
    elseif type(v) == "table"  then return ImVec2(_Trunc(v.x), _Trunc(v.y))
    end
end

ImTrunc64 = _Trunc

-- Consider using the bit-hack version (search for "0x1p120f").
--- @param f float
function ImCeilFast(f)
    local i
    if f >= 0 then i = math.floor(f) else i = math.ceil(f) end -- same as `ImTrunc()`
    if f > i then return i + 1 end
    return i
end

function IM_ROUNDUP_TO_EVEN(n) return (ImCeil((n) / 2) * 2) end
function ImRsqrt(x)            return (1 / ImSqrt(x))       end

function IM_TRUNC(VAL) return math.floor(VAL) end -- Positive values only!
function IM_ROUND(VAL) return math.floor(VAL + 0.5) end -- Positive values only!

function ImFloor(f) if f >= 0 or math.floor(f) == f then return math.floor(f) else return math.floor(f) - 1 end end -- Decent replacement for floorf()

-- Helpers: Bit manipulation
--- @param v int
function ImIsPowerOfTwo(v)
    return (v ~= 0) and (bitAnd(v, (v - 1)) == 0)
end

function ImUpperPowerOfTwo(v)
    if v <= 0 then return 0 end
    if v <= 1 then return 1 end

    v = v - 1
    v = bitOr(v, bitRShift(v, 1))
    v = bitOr(v, bitRShift(v, 2))
    v = bitOr(v, bitRShift(v, 4))
    v = bitOr(v, bitRShift(v, 8))
    v = bitOr(v, bitRShift(v, 16))
    return v + 1
end

--- @param v unsigned_int
--- @return unsigned_int
function ImCountSetBits(v)
    local count = 0
    while v > 0 do
        v = bitAnd(v, v - 1)
        count = count + 1
    end
    return count
end

--- @param avg    float
--- @param sample float
--- @param n      int
--- @return float
function ImStd.ImExponentialMovingAverage(avg, sample, n)
    avg = avg - avg / n
    avg = avg + sample / n
    return avg
end

-- Uses `string.match` internally
--- @param str string
function ImAtof(str)
    return tonumber(string.match(str, "[+-]?%d*%.?%d+"))
end

--- @param s table # 1-based
--- @param c any
--- @param n int
function ImStd.memset(s, c, n)
    for i = 1, n do s[i] = c end
end

do

local _memmove = function(dest, dest_start, src, src_start, count)
    if count <= 0 then return end

    -- more compact instead of writing separate if-else and for loops
    local c = (dest == src and dest_start >= src_start)
    for i = (c and count - 1 or 0), (c and 0 or count - 1), (c and -1 or 1) do
        dest[dest_start + i] = src[src_start + i]
    end
end

if table.move then
    --- [GMod] Platform specific: the `table.move` polyfill in non-x86-64 currently uses `unpack` which will break if too many elements
    -- Remove this check when the polyfill is fixed or removed
    if not gmod or (gmod and BRANCH == "x86-64") then
        _memmove = function(dest, dest_start, src, src_start, count)
            table.move(src, src_start, src_start + count - 1, dest_start, dest)
        end
    end
end

ImStd.memmove = _memmove

end

--- @param str1 ImStringBuffer
--- @param str2 ImStringBuffer
function ImStd.strcmp(str1, str2)
    local i = 1
    while true do
        local c1 = str1[i] or 0
        local c2 = str2[i] or 0

        if c1 ~= c2 then
            return c1 - c2
        end

        if c1 == 0 then
            return 0
        end

        i = i + 1
    end
end

--- @param str1      ImStringBuffer
--- @param str2      ImStringBuffer
--- @param max_count int
function ImStd.strncmp(str1, str2, max_count)
    for i = 1, max_count do
        local c1 = str1[i] or 0
        local c2 = str2[i] or 0

        if c1 ~= c2 then
            return c1 - c2
        end

        if c1 == 0 then
            return 0
        end
    end
    return 0
end

function ImSaturate(f) return ((f < 0.0 and 0.0) or (f > 1.0 and 1.0) or f) end

IM_F32_TO_INT8_UNBOUND = function(val) return math.floor(val * 255.0 + (val >= 0 and 0.5 or -0.5)) end -- Unsaturated, for display purpose
IM_F32_TO_INT8_SAT = function(val) return math.floor(ImSaturate(val) * 255.0 + 0.5) end -- Saturated, always output 0..255

--- @param s ImString
--- @param i int
--- @return char
function ImStrByte(s, i)
    if type(s) == "string" then
        return string.byte(s, i, i)
    else --- @cast s char[]
        return s[i]
    end
end

-- Stacked color modifier, backup of modified data so we can restore it
--- @class ImGuiColorMod
--- @field Col         ImGuiCol
--- @field BackupValue ImVec4

--- @param col          ImGuiCol
--- @param backup_value ImVec4
--- @return ImGuiColorMod
function ImGuiColorMod(col, backup_value)
    local this = {
        Col = col,
        BackupValue = ImVec4()
    }

    ImVec4_Copy(this.BackupValue, backup_value)

    return this
end

--- @param lhs ImVec2
--- @return float
function ImLengthSqr(lhs) return (lhs.x * lhs.x) + (lhs.y * lhs.y) end

--- @param v     ImVec2
--- @param cos_a float
--- @param sin_a float
--- @return ImVec2
--- @nodiscard
function ImRotate(v, cos_a, sin_a)
    return ImVec2(v.x * cos_a - v.y * sin_a, v.x * sin_a + v.y * cos_a)
end

--- @param a ImVec2
--- @param b ImVec2
function ImDot(a, b)
    return a.x * b.x + a.y * b.y
end

--- @param lhs ImVec2
--- @param rhs ImVec2
--- @nodiscard
function ImMul(lhs, rhs)
    return ImVec2(lhs.x * rhs.x, lhs.y * rhs.y)
end

--- @param str    char[]
--- @param begin? int
function ImStd.ImStrlen(str, begin)
    if begin == nil then begin = 1 end

    local l = #str

    for i = begin, l do
        if str[i] == 0 then
            return i - begin
        end
    end

    IM_ASSERT(false)
end

-- FIXME: should also accept count?
-- FIXME: avoid dynamic type checking?
-- string.find with patterns disabled
--- @param str        string|char[]
--- @param s          string|char
--- @param start_pos? int
--- @return int?
function ImMemchr(str, s, start_pos)
    local start = start_pos or 1
    if start < 1 then start = 1 end

    if type(str) == "table" then
        for i = start, #str do
            if str[i] == 0 then break end

            if str[i] == s then
                return i
            end
        end

        return nil
    end

    --- @cast str string
    local pos = string.find(str, s, start, true)

    return pos
end

IMGUI_FONT_SIZE_MAX                                = 512.0
IMGUI_FONT_SIZE_THRESHOLD_FOR_LOADADVANCEXONLYMODE = 128.0

IMGUI_WINDOW_HARD_MIN_SIZE = 4.0

-- ImDrawList: Lookup tables
IM_DRAWLIST_ARCFAST_TABLE_SIZE = 48 -- Number of samples in adaptive arc drawing lookup table.
IM_DRAWLIST_ARCFAST_SAMPLE_MAX = IM_DRAWLIST_ARCFAST_TABLE_SIZE -- Sample index _PathArcToFastEx() for 360 angle.

-- Macros used by Recoverable Error handling
-- - Only dispatch error if _EXPR: evaluate as assert (similar to an assert macro).
-- - The message will always be a string literal, in order to increase likelihood of being display by an assert handler.
-- - See 'Demo->Configuration->Error Handling' and ImGuiIO definitions for details on error handling.
-- - Read https://github.com/ocornut/imgui/wiki/Error-Handling for details on error handling.
-- Upstream: `if (!(expr) && ErrorLog(msg)) IM_ASSERT(0)`. ErrorLog() returns io.ConfigErrorRecoveryEnableAssert.
function IM_ASSERT_USER_ERROR(_EXPR, _MSG) if not (_EXPR) or (_EXPR) == 0 then if not ImGui.ErrorLog or ImGui.ErrorLog(_MSG) then error(_MSG, 2) end end end -- Recoverable User Error
function IM_ASSERT_USER_ERROR_RET(_EXPR, _MSG) if not (_EXPR) or (_EXPR) == 0 then error(_MSG, 2) end end

-- Debug Logging for ShowDebugLogWindow(). This is designed for relatively rare events so please don't spam.
local function DebugLogIf(flag, fmt, ...)
    local g = GImGui
    if g and bitAnd(g.DebugLogFlags, flag) ~= 0 then ImGui.DebugLog(fmt, ...) end
end
function IMGUI_DEBUG_LOG_ACTIVEID(...) DebugLogIf(ImGuiDebugLogFlags.EventActiveId, ...) end
function IMGUI_DEBUG_LOG_POPUP(...) DebugLogIf(ImGuiDebugLogFlags.EventPopup, ...) end
function IMGUI_DEBUG_LOG_FONT(...) DebugLogIf(ImGuiDebugLogFlags.EventFont, ...) end -- Called from ImFontAtlas function which may operate without a context.
function IMGUI_DEBUG_LOG_VIEWPORT(...) DebugLogIf(ImGuiDebugLogFlags.EventViewport, ...) end
function IMGUI_DEBUG_LOG_FOCUS(...) DebugLogIf(ImGuiDebugLogFlags.EventFocus, ...) end
function IMGUI_DEBUG_LOG_NAV(...) DebugLogIf(ImGuiDebugLogFlags.EventNav, ...) end
function IMGUI_DEBUG_LOG_IO(...) DebugLogIf(ImGuiDebugLogFlags.EventIO, ...) end
function IMGUI_DEBUG_LOG_INPUTROUTING(...) DebugLogIf(ImGuiDebugLogFlags.EventInputRouting, ...) end
function IMGUI_DEBUG_LOG_TABLE(...) DebugLogIf(ImGuiDebugLogFlags.EventTable, ...) end
function IMGUI_DEBUG_LOG_DOCKING(...) DebugLogIf(ImGuiDebugLogFlags.EventDocking, ...) end
function IMGUI_DEBUG_LOG_SELECTION(...) DebugLogIf(ImGuiDebugLogFlags.EventSelection, ...) end
function IMGUI_DEBUG_LOG_CLIPPER(...) DebugLogIf(ImGuiDebugLogFlags.EventClipper, ...) end
function IMGUI_DEBUG_LOG_ERROR(...) DebugLogIf(ImGuiDebugLogFlags.EventError, ...) end

--- @alias ImGuiSelectionUserData any
ImGuiSelectionUserData_Invalid = -1

-- Input function taking an 'ImGuiID owner_id' argument defaults to (ImGuiKeyOwner_Any == 0) aka don't test ownership, which matches legacy behavior.
ImGuiKeyOwner_Any     = 0 -- Accept key that have an owner, UNLESS a call to SetKeyOwner() explicitly used ImGuiInputFlags.LockThisFrame or ImGuiInputFlags.LockUntilRelease.
ImGuiKeyOwner_NoOwner = 4294967295 -- Require key to have no owner.

-------------------------------------------------------------------------------
-- [SECTION] ImGui internal API
-- No guarantee of forward compatibility here!
-------------------------------------------------------------------------------

-- Inputs
-- FIXME: Eventually we should aim to move e.g. IsActiveIdUsingKey() into IsKeyXXX functions.
--- @param button ImGuiMouseButton
--- @return ImGuiKey
function ImGui.MouseButtonToKey(button) IM_ASSERT(button >= 0 and button < ImGuiMouseButton.COUNT) return ImGuiKey.MouseLeft + button end

--- @param key ImGuiKey
function ImGui.IsNamedKey(key)
    return key >= ImGuiKey.NamedKey_BEGIN and key < ImGuiKey.NamedKey_END
end

--- @param key ImGuiKey
function ImGui.IsKeyboardKey(key)
    return key >= ImGuiKey_Keyboard_BEGIN and key < ImGuiKey_Keyboard_END
end

--- @param key ImGuiKey
function ImGui.IsGamepadKey(key)
    return key >= ImGuiKey_Gamepad_BEGIN and key < ImGuiKey_Gamepad_END
end

--- @param key ImGuiKey
function ImGui.IsMouseKey(key)
    return key >= ImGuiKey_Mouse_BEGIN and key < ImGuiKey_Mouse_END
end

--- @param key ImGuiKey
function ImGui.IsAliasKey(key)
    return key >= ImGuiKey_Aliases_BEGIN and key < ImGuiKey_Aliases_END
end

--- @param key ImGuiKey
function ImGui.IsLRModKey(key)
    return key >= ImGuiKey.LeftCtrl and key <= ImGuiKey.RightSuper
end

--- @param key ImGuiKey
--- @return bool
function ImGui.IsNamedKeyOrMod(key)
    return (key >= ImGuiKey.NamedKey_BEGIN and key < ImGuiKey.NamedKey_END) or key == ImGuiMod_Ctrl or key == ImGuiMod_Shift or key == ImGuiMod_Alt or key == ImGuiMod_Super
end

--- @param key ImGuiKey
--- @return ImGuiKey
function ImGui.ConvertSingleModFlagToKey(key)
    if key == ImGuiMod_Ctrl then
        return ImGuiKey.ReservedForModCtrl
    elseif key == ImGuiMod_Shift then
        return ImGuiKey.ReservedForModShift
    elseif key == ImGuiMod_Alt then
        return ImGuiKey.ReservedForModAlt
    elseif key == ImGuiMod_Super then
        return ImGuiKey.ReservedForModSuper
    end
    return key
end

-- [EXPERIMENTAL] Low-Level: Key/Input Ownership
-- - The idea is that instead of "eating" a given input, we can link to an owner id.
-- - Ownership is most often claimed as a result of reacting to a press/down event (but occasionally may be claimed ahead).
-- - Input queries can then read input by specifying ImGuiKeyOwner_Any (== 0), ImGuiKeyOwner_NoOwner (== -1) or a custom ID.
-- - Legacy input queries (without specifying an owner or _Any or _None) are equivalent to using ImGuiKeyOwner_Any (== 0).
-- - Input ownership is automatically released on the frame after a key is released. Therefore:
--   - for ownership registration happening as a result of a down/press event, the SetKeyOwner() call may be done once (common case).
--   - for ownership registration happening ahead of a down/press event, the SetKeyOwner() call needs to be made every frame (happens if e.g. claiming ownership on hover).
-- - SetItemKeyOwner() is a shortcut for common simple case. A custom widget will probably want to call SetKeyOwner() multiple times directly based on its interaction state.
-- - This is marked experimental because not all widgets are fully honoring the Set/Test idioms. We will need to move forward step by step.
--   Please open a GitHub Issue to submit your usage scenario or if there's a use case you need solved.
--- @param ctx ImGuiContext
--- @param key ImGuiKey
function ImGui.GetKeyOwnerData(ctx, key)
    if bitAnd(key, ImGuiMod_Mask_) ~= 0 then key = ImGui.ConvertSingleModFlagToKey(key) end
    IM_ASSERT(ImGui.IsNamedKey(key))
    return ctx.KeysOwnerData[key - ImGuiKey.NamedKey_BEGIN]
end

-- This extends ImGuiKeyData but only for named keys (legacy keys don't support the new features)
-- Stored in main context (1 per named key). In the future it might be merged into ImGuiKeyData.
--- @class ImGuiKeyOwnerData

--- @return ImGuiKeyOwnerData
--- @nodiscard
function ImGuiKeyOwnerData()
    return {
        OwnerCurr        = ImGuiKeyOwner_NoOwner,
        OwnerNext        = ImGuiKeyOwner_NoOwner,
        LockThisFrame    = false, -- Reading this key requires explicit owner id (until end of frame). Set by ImGuiInputFlags.LockThisFrame.
        LockUntilRelease = false  -- Reading this key requires explicit owner id (until key is released). Set by ImGuiInputFlags.LockUntilRelease. When this is true LockThisFrame is always true as well.
    }
end

--- @param size float
--- @return float
function ImGui.GetRoundedFontSize(size) return IM_ROUND(size) end

--- @param window ImGuiWindow
--- @param r      ImRect
--- @return ImRect
--- @nodiscard
function ImGui.WindowRectAbsToRel(window, r) local off = window.DC.CursorStartPos return ImRect(r.Min.x - off.x, r.Min.y - off.y, r.Max.x - off.x, r.Max.y - off.y) end

--- @param window ImGuiWindow
--- @param r      ImRect
--- @nodiscard
function ImGui.WindowRectRelToAbs(window, r) local off = window.DC.CursorStartPos return ImRect(r.Min.x + off.x, r.Min.y + off.y, r.Max.x + off.x, r.Max.y + off.y) end

--- @param dir ImGuiDir
--- @return bool
function ImGui.IsActiveIdUsingNavDir(dir)
    local g = GImGui
    return bit32.band(g.ActiveIdUsingNavDirMask, bit32.lshift(1, dir)) ~= 0
end

--- @param window ImGuiWindow
--- @param p      ImVec2
--- @return ImVec2
--- @nodiscard
function ImGui.WindowPosAbsToRel(window, p) local off = window.DC.CursorStartPos return ImVec2(p.x - off.x, p.y - off.y) end

--- @param c char
--- @return bool # True if this character is a ' ' or '\t'
function ImCharIsBlankA(c) return c == 32 or c == 9 end

--- @param c char
function ImCharIsBlankW(c) return c == 32 or c == 9 or c == 0x3000 end

--- @enum ImGuiNavMoveFlags
ImGuiNavMoveFlags =
{
    None                  = 0,
    LoopX                 = bitLShift(1, 0), -- On failed request, restart from opposite side
    LoopY                 = bitLShift(1, 1),
    WrapX                 = bitLShift(1, 2), -- On failed request, request from opposite side one line down (when NavDir==right) or one line up (when NavDir==left)
    WrapY                 = bitLShift(1, 3), -- This is not super useful but provided for completeness
    AllowCurrentNavId     = bitLShift(1, 4), -- Allow scoring and considering the current NavId as a move target candidate. This is used when the move source is offset (e.g. pressing PageDown actually needs to send a Up move request, if we are pressing PageDown from the bottom-most item we need to stay in place)
    AlsoScoreVisibleSet   = bitLShift(1, 5), -- Store alternate result in NavMoveResultLocalVisible that only comprise elements that are already fully visible (used by PageUp/PageDown)
    ScrollToEdgeY         = bitLShift(1, 6), -- Force scrolling to min/max (used by Home/End) -- FIXME-NAV: Aim to remove or reword as ImGuiScrollFlags
    Forwarded             = bitLShift(1, 7),
    DebugNoResult         = bitLShift(1, 8), -- Dummy scoring for debug purpose, don't apply result
    FocusApi              = bitLShift(1, 9), -- Requests from focus API can land/focus/activate items even if they are marked with _NoTabStop (see NavProcessItemForTabbingRequest() for details)
    IsTabbing             = bitLShift(1, 10), -- == Focus + Activate if item is Inputable + DontChangeNavHighlight
    IsPageMove            = bitLShift(1, 11), -- Identify a PageDown/PageUp request.
    Activate              = bitLShift(1, 12), -- Activate/select target item.
    NoSelect              = bitLShift(1, 13), -- Don't trigger selection by not setting g.NavJustMovedTo
    NoSetNavCursorVisible = bitLShift(1, 14), -- Do not alter the nav cursor visible state
    NoClearActiveId       = bitLShift(1, 15), -- (Experimental) Do not clear active id when applying move result
}

ImGuiNavMoveFlags.WrapMask_ = bitOr(ImGuiNavMoveFlags.LoopX, ImGuiNavMoveFlags.LoopY, ImGuiNavMoveFlags.WrapX, ImGuiNavMoveFlags.WrapY)

--- @enum ImGuiNavLayer
ImGuiNavLayer =
{
    Main  = 0, -- Main scrolling layer
    Menu  = 1, -- Menu layer (access with Alt)
    COUNT = 2
}

-------------------------------------------------------------------------------
-- [SECTION] Widgets support: flags, enums, data structures
-------------------------------------------------------------------------------

-- Extend ImGuiItemFlags
-- - input: PushItemFlag() manipulates g.CurrentItemFlags, g.NextItemData.ItemFlags, ItemAdd() calls may add extra flags too.
-- - output: stored in g.LastItemData.ItemFlags

-- Controlled by user
ImGuiItemFlags.ReadOnly               = bitLShift(1, 11) -- false -- [ALPHA] Allow hovering interactions but underlying value is not changed.
ImGuiItemFlags.MixedValue             = bitLShift(1, 12)
ImGuiItemFlags.NoWindowHoverableCheck = bitLShift(1, 13) -- false -- Disable hoverable check in ItemHoverable()
ImGuiItemFlags.AllowOverlap           = bitLShift(1, 14) -- false -- Allow being overlapped by another widget. Not-hovered to Hovered transition deferred by a frame.
ImGuiItemFlags.NoNavDisableMouseHover = bitLShift(1, 15) -- false -- Nav keyboard/gamepad mode doesn't disable hover highlight (behave as if NavHighlightItemUnderNav==false).
ImGuiItemFlags.NoMarkEdited           = bitLShift(1, 16) -- false -- Skip calling MarkItemEdited()
ImGuiItemFlags.NoFocus                = bitLShift(1, 17) -- false -- [EXPERIMENTAL: Not very well specced] Clicking doesn't take focus. Automatically sets ImGuiButtonFlags.NoFocus + ImGuiButtonFlags.NoNavFocus in ButtonBehavior().

-- Controlled by widget code
ImGuiItemFlags.Inputable            = bitLShift(1, 20) -- false -- [WIP] Auto-activate input mode when tab focused. Currently only used and supported by a few items before it becomes a generic feature.
ImGuiItemFlags.HasSelectionUserData = bitLShift(1, 21) -- false -- Set by SetNextItemSelectionUserData()
ImGuiItemFlags.IsMultiSelect        = bitLShift(1, 22) -- false -- Set by SetNextItemSelectionUserData()

ImGuiItemFlags.Default_ = bitOr(ImGuiItemFlags.AutoClosePopups, ImGuiItemFlags.LiveEditOnInputText) -- Please don't change, use PushItemFlag() instead.

-- Helpers: High-level text functions (DO NOT USE!!! THIS IS A MINIMAL SUBSET OF LARGER UPCOMING CHANGES)
--- @enum ImDrawTextFlags
ImDrawTextFlags =
{
    None           = 0,
    CpuFineClip    = bitLShift(1, 0), -- Must be == 1/true for legacy with 'bool cpu_fine_clip' arg to RenderText()
    WrapKeepBlanks = bitLShift(1, 1),
    StopOnNewLine  = bitLShift(1, 2)
}

-- Flags for FocusWindow(). This is not called ImGuiFocusFlags to avoid confusion with public-facing ImGuiFocusedFlags.
-- FIXME: Once we finishing replacing more uses of GetTopMostPopupModal()+IsWindowWithinBeginStackOf()
-- and FindBlockingModal() with this, we may want to change the flag to be opt-out instead of opt-in.
--- @enum ImGuiFocusRequestFlags
ImGuiFocusRequestFlags =
{
    None                = 0,
    RestoreFocusedChild = bitLShift(1, 0), -- Find last focused child (if any) and focus it instead.
    UnlessBelowModal    = bitLShift(1, 1)  -- Do not set focus if the window is below a modal.
}

--- @enum ImGuiTextFlags
ImGuiTextFlags =
{
    None                       = 0,
    NoWidthForLargeClippedText = bitLShift(1, 0)
}

-- Character classification for word-wrapping logic
--- @enum ImWcharClass
ImWcharClass =
{
    Blank = 0,
    Punct = 1,
    Other = 2
}

-- Helper: ImVec1 (1D vector)
-- (this odd construct is used to facilitate the transition between 1D and 2D, and the maintenance of some branches/patches)
--- @class ImVec1
--- @field x number
local IM_VEC1 = {}
IM_VEC1.__index = IM_VEC1

local function ImVec1(x) return setmetatable({x = x or 0}, IM_VEC1) end

function IM_VEC1:__tostring() return string.format("ImVec1(%g)", self.x) end

--- @param dest ImVec1
--- @param src  ImVec1
function ImVec1_Copy(dest, src)
    dest.x = src.x
end

-- Helper: ImRect (2D axis aligned bounding-box)
-- NB: we can't rely on ImVec2 math operators being available here!
--- @class ImRect
--- @field [1] ImVec2
--- @field [2] ImVec2
--- @field Min ImVec2 # Upper-left
--- @field Max ImVec2 # Lower-right
local IM_RECT = {}
setmetatable(IM_RECT, { __index = function(_, k) if k ~= "Min" and k ~= "Max" then error("ImRect: unknown key " .. tostring(k), 2) end end })

--- @param t ImRect
--- @param k string
IM_RECT.__index = IM_RECT -- [Luau] plain table: fast method lookup. Use r.Min / r.Max (numeric r[1]/r[2] are not supported)

-- [Luau] Min/Max are named fields, so `r.Min = v` assigns the reference: use ImVec2_Copy(r.Min, v) to keep copy semantics
IM_RECT.__newindex = function(t, k, v) IM_ASSERT(false, "ImRect: unknown field " .. tostring(k)) end

--- @return ImRect
--- @nodiscard

function ImRect(a, b, c, d) if c and d then return setmetatable({ Min = ImVec2(a, b), Max = ImVec2(c, d) }, IM_RECT) end return setmetatable({ Min = ImVec2(a and a.x or 0, a and a.y or 0), Max = ImVec2(b and b.x or 0, b and b.y or 0) }, IM_RECT) end

function IM_RECT:__eq(other) return self.Min == other.Min and self.Max == other.Max end
function IM_RECT:__tostring() return string.format("ImRect(Min: %g,%g, Max: %g,%g)", self.Min.x, self.Min.y, self.Max.x, self.Max.y) end

--- @param p ImRect|ImVec2

function IM_RECT:Contains(p)
    if p.Min then
        --- @cast p ImRect
        return p.Min.x >= self.Min.x and p.Max.x <= self.Max.x and p.Min.y >= self.Min.y and p.Max.y <= self.Max.y
    else
        --- @cast p ImVec2
        return p.x >= self.Min.x and p.y >= self.Min.y and p.x < self.Max.x and p.y < self.Max.y
    end
end

--- @param p   ImVec2
--- @param pad ImVec2
function IM_RECT:ContainsWithPad(p, pad)
    return p.x >= self.Min.x - pad.x and p.y >= self.Min.y - pad.y and p.x < self.Max.x + pad.x and p.y < self.Max.y + pad.y
end

--- @param r ImRect

function IM_RECT:Overlaps(r)
    return self.Min.x <= r.Max.x and self.Max.x >= r.Min.x and self.Min.y <= r.Max.y and self.Max.y >= r.Min.y
end

--- @nodiscard
function IM_RECT:GetCenter() return ImVec2((self.Min.x + self.Max.x) * 0.5, (self.Min.y + self.Max.y) * 0.5) end
function IM_RECT:GetWidth() return self.Max.x - self.Min.x end
function IM_RECT:GetHeight() return self.Max.y - self.Min.y end
--- @nodiscard

function IM_RECT:GetSize() return ImVec2(self.Max.x - self.Min.x, self.Max.y - self.Min.y) end

--- @nodiscard
function IM_RECT:GetTL() return ImVec2(self.Min.x, self.Min.y) end -- Top-left
--- @nodiscard
function IM_RECT:GetTR() return ImVec2(self.Max.x, self.Min.y) end -- Top-right
--- @nodiscard
function IM_RECT:GetBL() return ImVec2(self.Min.x, self.Max.y) end -- Bottom-left
--- @nodiscard
function IM_RECT:GetBR() return ImVec2(self.Max.x, self.Max.y) end -- Bottom-right

-- Simple version, may lead to an inverted rectangle, which is fine for Contains/Overlaps test but not for display.
--- @param r ImRect

function IM_RECT:ClipWith(r)
    -- [Luau] scalar math, no temporary ImVec2 (= ImMax(Min, r.Min) / ImMin(Max, r.Max))
    local smin, smax, rmin, rmax = self.Min, self.Max, r.Min, r.Max
    smin.x = mathMax(smin.x, rmin.x); smin.y = mathMax(smin.y, rmin.y)
    smax.x = mathMin(smax.x, rmax.x); smax.y = mathMin(smax.y, rmax.y)
end

-- Full version, ensure both points are fully clipped.
--- @param r ImRect

function IM_RECT:ClipWithFull(r)
    -- [Luau] scalar math, no temporary ImVec2 (= ImClamp(Min/Max, r.Min, r.Max))
    local smin, smax, rmin, rmax = self.Min, self.Max, r.Min, r.Max
    local min_x, min_y, max_x, max_y = rmin.x, rmin.y, rmax.x, rmax.y
    smin.x = mathMax(min_x, mathMin(smin.x, max_x)); smin.y = mathMax(min_y, mathMin(smin.y, max_y))
    smax.x = mathMax(min_x, mathMin(smax.x, max_x)); smax.y = mathMax(min_y, mathMin(smax.y, max_y))
end

--- @param p ImRect|ImVec2

function IM_RECT:Add(p)
    if p.Min then
        --- @cast p ImRect
        if (self.Min.x > p.Min.x) then self.Min.x = p.Min.x end
        if (self.Min.y > p.Min.y) then self.Min.y = p.Min.y end
        if (self.Max.x < p.Max.x) then self.Max.x = p.Max.x end
        if (self.Max.y < p.Max.y) then self.Max.y = p.Max.y end
    else
        --- @cast p ImVec2
        if p.x < self.Min.x then self.Min.x = p.x end
        if p.y < self.Min.y then self.Min.y = p.y end
        if p.x > self.Max.x then self.Max.x = p.x end
        if p.y > self.Max.y then self.Max.y = p.y end
    end
end

--- @param amount float|ImVec2

function IM_RECT:Expand(amount)
    if     type(amount) == "number" then
        self.Min.x = self.Min.x - amount; self.Min.y = self.Min.y - amount
        self.Max.x = self.Max.x + amount; self.Max.y = self.Max.y + amount
    elseif type(amount) == "table"  then
        self.Min.x = self.Min.x - amount.x; self.Min.y = self.Min.y - amount.y
        self.Max.x = self.Max.x + amount.x; self.Max.y = self.Max.y + amount.y
    end
end

--- @nodiscard
function IM_RECT:ToVec4()
    return ImVec4(self.Min.x, self.Min.y, self.Max.x, self.Max.y)
end

--- @param d ImVec2

function IM_RECT:Translate(d)
    self.Min.x = self.Min.x + d.x; self.Min.y = self.Min.y + d.y
    self.Max.x = self.Max.x + d.x; self.Max.y = self.Max.y + d.y
end

--- @param dx float
function IM_RECT:TranslateX(dx)
    self.Min.x = self.Min.x + dx; self.Max.x = self.Max.x + dx
end

--- @param dy float
function IM_RECT:TranslateY(dy)
    self.Min.y = self.Min.y + dy; self.Max.y = self.Max.y + dy
end

function IM_RECT:IsInverted() return self.Min.x > self.Max.x or self.Min.y > self.Max.y end

function IM_RECT:GetArea() return (self.Max.x - self.Min.x) * (self.Max.y - self.Min.y) end

--- @nodiscard
function IM_RECT:AsVec4() return ImVec4(self.Min.x, self.Min.y, self.Max.x, self.Max.y) end

--- @param dest ImRect
--- @param src  ImRect

function ImRect_Copy(dest, src)
    dest.Min.x = src.Min.x; dest.Min.y = src.Min.y
    dest.Max.x = src.Max.x; dest.Max.y = src.Max.y
end

--- @param dest ImRect
--- @param src  ImVec4
function ImRect_CopyFromV4(dest, src)
    dest.Min.x = src.x; dest.Min.y = src.y
    dest.Max.x = src.z; dest.Max.y = src.w
end

-- Helper: ImBitArray
-- Macro version of ImBitArrayTestBit(): ensure args have side-effect or are costly!
--- @param _ARRAY ImU32[]
--- @param _N     int
function IM_BITARRAY_TESTBIT(_ARRAY, _N)
    return bitAnd(_ARRAY[bitRShift(_N - 1, 5) + 1], bitLShift(1, bitAnd(_N - 1, 31))) ~= 0
end

-- Macro version of ImBitArrayClearBit(): ensure args have side-effect or are costly!
--- @param _ARRAY ImU32[]
--- @param _N     int
function IM_BITARRAY_CLEARBIT(_ARRAY, _N)
    local idx = bitRShift(_N - 1, 5) + 1
    _ARRAY[idx] = bitAnd(_ARRAY[idx], bitNot(bitLShift(1, bitAnd(_N - 1, 31))))
end

--- @param arr ImU32[]
--- @param n   int
function ImBitArraySetBit(arr, n)
    local mask = bitLShift(1, bitAnd(n - 1, 31))
    local idx = bitRShift(n - 1, 5) + 1
    arr[idx] = bitOr(arr[idx], mask)
end

-- Bit array for named keys
--- @alias ImBitArrayForNamedKeys ImBitArray

-- Helper: ImBitArray class (wrapper over ImBitArray functions)
-- Store 1-bit per value.
--- NOTE: This struct is expensive to create
--- @class ImBitArray<BITCOUNT, OFFSET>
--- @field Data ImU32[]

--- @param BITCOUNT int
--- @param OFFSET?  int
--- @return ImBitArray
function ImBitArray(BITCOUNT, OFFSET)
    if OFFSET == nil then OFFSET = 0 end

    local this = { Data = {} }
    local size = bitRShift(BITCOUNT + 31, 5)

    this.ClearAllBits = function(self) local data = self.Data; for i = 1, size do data[i] = 0 end end
    this.SetAllBits   = function(self) local data = self.Data; for i = 1, size do data[i] = 0xFFFFFFFF end end
    --- @param n int # 1-based
    --- @return boolean
    this.TestBit = function(self, n) n = n + OFFSET; IM_ASSERT(n >= 1 and n <= BITCOUNT); return IM_BITARRAY_TESTBIT(self.Data, n); end
    --- @param n int # 1-based
    this.SetBit  = function(self, n) n = n + OFFSET; IM_ASSERT(n >= 1 and n <= BITCOUNT); ImBitArraySetBit(self.Data, n); end

    this:ClearAllBits()

    return this
end

-- Stateful path API, add points then finish with PathFillConvex() or PathStroke()
-- - Important: filled shapes must always use clockwise winding order! The anti-aliasing fringe depends on it. Counter-clockwise shapes will have "inward" anti-aliasing.
--   so e.g. 'PathArcTo(center, radius, PI * -0.5, PI)' is ok, whereas 'PathArcTo(center, radius, PI, PI * -0.5)' won't have correct anti-aliasing when followed by PathFillConvex().
function MT.ImDrawList:PathClear() self._Path:clear() end

--- @param pos ImVec2

function MT.ImDrawList:PathLineTo(pos)
    -- [Luau] inline self._Path:push_back(pos) (ImVec2_TCopy into the preallocated slot)
    local path = self._Path
    local n = path.Size + 1
    if n > path.Capacity then path:push_back(pos) return end
    local dest = path.Data[n]
    dest.x = pos.x; dest.y = pos.y
    path.Size = n
end

function MT.ImDrawList:PathLineToMergeDuplicate(pos)
    local path_size = self._Path.Size
    if path_size == 0 or self._Path.Data[path_size].x ~= pos.x or self._Path.Data[path_size].y ~= pos.y then
        self._Path:push_back(pos)
    end
end


function MT.ImDrawList:PathFillConvex(col)
    self:AddConvexPolyFilled(self._Path.Data, self._Path.Size, col)
    self._Path.Size = 0
end

--- @param col        ImU32
--- @param thickness? float
--- @param flags?     ImDrawFlags
function MT.ImDrawList:PathStroke(col, thickness, flags)
    if not thickness then thickness = 1.0 end
    if not flags     then flags     = 0   end

    self:AddPolyline(self._Path.Data, self._Path.Size, col, thickness, flags)
    self._Path.Size = 0
end

--- @param col ImU32
function ImGui.SetNextItemColorMarker(col)
    local g = GImGui
    g.NextItemData.HasFlags = bitOr(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasColorMarker)
    g.NextItemData.ColorMarker = col
end

-------------------------------------------------------------------------------
-- [SECTION] ImDrawList support
-------------------------------------------------------------------------------

-- Data shared between all ImDrawList instances
-- Conceptually this could have been called e.g. ImDrawListSharedContext
-- Typically one ImGui context would create and maintain one of this.
-- You may want to create your own instance of you try to ImDrawList completely without ImGui. In that case, watch out for future changes to this structure.
--- @class ImDrawListSharedData
--- @field TexUvWhitePixel       ImVec2 # UV of white pixel in the atlas (== FontAtlas->TexUvWhitePixel)
--- @field TexUvLines            ImVec4[] # UV of anti-aliased lines in the atlas (== FontAtlas->Builder->TexUvLines)
--- @field FontAtlas             ImFontAtlas # Current font atlas
--- @field Font                  ImFont # Current font (used for simplified AddText overload)
--- @field FontSize              float # Current font size (used for simplified AddText overload)
--- @field FontScale             float # Current font scale (== FontSize / Font->FontSize)
--- @field CurveTessellationTol  float
--- @field CircleTessellationMaxError float # Number of circle segments to use per pixel of radius for AddCircle() etc
--- @field InitialFringeScale    float
--- @field InitialFlags          ImDrawListFlags
--- @field ClipRectFullscreen?   ImVec4 # Value for PushClipRectFullscreen()
--- @field TempBuffer            ImVector<ImVec2> # Temporary write buffer
--- @field DrawLists             ImVector<ImDrawList> # All draw lists associated to this ImDrawListSharedData
--- @field Context?              ImGuiContext # [OPTIONAL] Link to Dear ImGui context. 99% of ImDrawList/ImFontAtlas can function without an ImGui context, but this facilitate handling one legacy edge case.
--- @field ArcFastVtx            table<ImVec2>        # 1-based table. Sample points on the quarter of the circle.
--- @field ArcFastRadiusCutoff   float # Cutoff radius after which arc drawing will fallback to slower PathArcTo()
--- @field CircleSegmentCounts   table<int>           # 1-based table. Precomputed segment count for given radius before we calculate it dynamically (to avoid calculation overhead)
MT.ImDrawListSharedData = {}
MT.ImDrawListSharedData.__index = MT.ImDrawListSharedData

--- @return ImDrawListSharedData
--- @nodiscard
function ImDrawListSharedData()
    local this = setmetatable({
        TexUvWhitePixel = nil, -- UV of white pixel in the atlas (== FontAtlas->TexUvWhitePixel)
        TexUvLines      = nil, -- UV of anti-aliased lines in the atlas (== FontAtlas->Builder->TexUvLines)
        FontAtlas       = nil, -- Current font atlas

        Font      = nil, -- Current font (used for simplified AddText overload)
        FontSize  = 0,   -- Current font size (used for simplified AddText overload)
        FontScale = 0,   -- Current font scale (== FontSize / Font->FontSize)

        CurveTessellationTol  = 0,
        CircleTessellationMaxError = 0, -- Number of circle segments to use per pixel of radius for AddCircle() etc
        InitialFringeScale    = 1,

        InitialFlags          = 0,
        ClipRectFullscreen    = nil, -- Value for PushClipRectFullscreen()
        TempBuffer            = ImVector(ImVec2), -- Temporary write buffer
        DrawLists             = ImVector(), -- All draw lists associated to this ImDrawListSharedData

        -- Lookup tables
        ArcFastVtx          = {},  -- Sample points on the quarter of the circle.
        ArcFastRadiusCutoff = nil, -- Cutoff radius after which arc drawing will fallback to slower PathArcTo()
        CircleSegmentCounts = {},  -- Precomputed segment count for given radius before we calculate it dynamically (to avoid calculation overhead)

        Context = nil -- [OPTIONAL] Link to Dear ImGui context. 99% of ImDrawList/ImFontAtlas can function without an ImGui context, but this facilitate handling one legacy edge case.
    }, MT.ImDrawListSharedData)

    for i = 1, IM_DRAWLIST_ARCFAST_TABLE_SIZE do
        local a = ((i - 1) * 2 * IM_PI) / IM_DRAWLIST_ARCFAST_TABLE_SIZE
        this.ArcFastVtx[i] = ImVec2(ImCos(a), ImSin(a))
    end

    return this
end

-- Internal storage for incrementally packing and building a ImFontAtlas
--- @class ImFontAtlasBuilder
--- @field PackContext              stbrp_context
--- @field PackNodes                ImVector<stbrp_node>
--- @field Rects                    ImVector<ImTextureRect>
--- @field RectsIndex               ImVector<ImFontAtlasRectEntry>
--- @field TempBuffer               ImVector<char>
--- @field RectsIndexFreeListStart  int
--- @field RectsPackedCount         int
--- @field RectsPackedSurface       int
--- @field RectsDiscardedCount      int
--- @field RectsDiscardedSurface    int
--- @field FrameCount               int
--- @field MaxRectSize              ImVec2
--- @field MaxRectBounds            ImVec2
--- @field LockDisableResize        bool
--- @field PreloadedAllGlyphsRanges bool
--- @field BakedPool                ImVector<ImFontBaked>
--- @field BakedMap                 table<ImGuiID, any>            # LUA: No ImGuiStorage
--- @field BakedDiscardedCount      int
--- @field PackIdMouseCursors       ImFontAtlasRectId
--- @field PackIdLinesTexData       ImFontAtlasRectId
MT.ImFontAtlasBuilder = {}
MT.ImFontAtlasBuilder.__index = MT.ImFontAtlasBuilder

--- @return ImFontAtlasBuilder
function ImFontAtlasBuilder()
    --- @type ImFontAtlasBuilder
    local this = setmetatable({}, MT.ImFontAtlasBuilder)

    this.PackContext              = nil -- struct stbrp_context_opaque { char data[80]; }; -- Actually 'stbrp_context' but we don't want to define this in the header file.
    this.PackNodes                = ImVector()
    this.Rects                    = ImVector()
    this.RectsIndex               = ImVector() -- ImFontAtlasRectId -> index into Rects[]
    this.TempBuffer               = ImVector() -- Misc scratch buffer
    this.RectsIndexFreeListStart  = -1 -- First unused entry
    this.RectsPackedCount         = 0 -- Number of packed rectangles.
    this.RectsPackedSurface       = 0 -- Number of packed pixels. Used when compacting to heuristically find the ideal texture size.
    this.RectsDiscardedCount      = 0
    this.RectsDiscardedSurface    = 0
    this.FrameCount               = -1 -- Current frame count
    this.MaxRectSize              = ImVec2() -- Largest rectangle to pack (de-facto used as a "minimum texture size")
    this.MaxRectBounds            = ImVec2() -- Bottom-right most used pixels
    this.LockDisableResize        = false -- Disable resizing texture
    this.PreloadedAllGlyphsRanges = false -- Set when missing ImGuiBackendFlags.RendererHasTextures features forces atlas to preload everything.

    -- Cache of all ImFontBaked
    this.BakedPool           = ImVector() -- ImStableVector<ImFontBaked,32>
    this.BakedMap            = {} -- BakedId --> ImFontBaked
    this.BakedDiscardedCount = 0

    -- Custom rectangle identifiers
    this.PackIdMouseCursors = -1 -- White pixel + mouse cursors. Also happen to be fallback in case of packing failure.
    this.PackIdLinesTexData = -1

    return this
end

--- @class ImFontStackData
--- @field Font                  ImFont
--- @field FontSizeBeforeScaling float # ~~ style.FontSizeBase
--- @field FontSizeAfterScaling  float # ~~ g.FontSize

--- @return ImFontStackData
--- @param font                     ImFont
--- @param font_size_before_scaling float
--- @param font_size_after_scaling  float
--- @nodiscard
function ImFontStackData(font, font_size_before_scaling, font_size_after_scaling)
    return {
        Font                  = font,
        FontSizeBeforeScaling = font_size_before_scaling, -- ~~ style.FontSizeBase
        FontSizeAfterScaling  = font_size_after_scaling   -- ~~ g.FontSize
    }
end

-------------------------------------------------------------------------------
-- [SECTION] Style support
-------------------------------------------------------------------------------

--- `GetVarPtr()` is currently only used on `g.Style` in Dear ImGui, and we don't have pointers!
--- @class ImGuiStyleVarInfo
--- @field Count    ImU32         # 1+
--- @field DataType ImGuiDataType
--- @field Key      string        # key in parent structure. Note that the cpp Dear ImGui uses `ImU32 Offset`!

--- @param count     ImU32
--- @param data_type ImGuiDataType
--- @param key       string
--- @return ImGuiStyleVarInfo
--- @nodiscard
function ImGuiStyleVarInfo(count, data_type, key)
    return { Count = count, DataType = data_type, Key = key }
end

-- Stacked style modifier, backup of modified data so we can restore it. Data type inferred from the variable.
--- @class ImGuiStyleMod
--- @field VarIdx       ImGuiStyleVar
--- @field BackupVal    table

--- @param idx ImGuiStyleVar
--- @param v   int|float|ImVec2
function ImGuiStyleMod(idx, v)
    local this = { VarIdx = idx, BackupVal = {nil, nil} }
    --- @cast this ImGuiStyleMod

    if type(v) == "number" then
        this.BackupVal[1] = v
    else -- ImVec2
        this.BackupVal[1] = v.x; this.BackupVal[2] = v.y
    end

    return this
end

-------------------------------------------------------------------------------
-- [SECTION] Data types support
-------------------------------------------------------------------------------

-- Type information associated to one ImGuiDataType. Retrieve with DataTypeGetInfo().
--- @class ImGuiDataTypeInfo
--- @field Size     size_t # Size in bytes
--- @field Name     string # Short descriptive name for the type, for debugging
--- @field PrintFmt string # Default printf format for the type
--- @field ScanFmt  string # Default scanf format for the type

-- Status storage for the last submitted item
--- @class ImGuiLastItemData
--- @field ID          ImGuiID
--- @field ItemFlags   ImGuiItemFlags       # See ImGuiItemFlags (called 'InFlags' before v1.91.4).
--- @field StatusFlags ImGuiItemStatusFlags # See ImGuiItemStatusFlags
--- @field Rect        ImRect               # Full rectangle
--- @field NavRect     ImRect               # Navigation scoring rectangle (not displayed)
--- @field DisplayRect ImRect               # Display rectangle. ONLY VALID IF (StatusFlags & ImGuiItemStatusFlags.HasDisplayRect) is set.
--- @field ClipRect    ImRect               # Clip rectangle at the time of submitting item. ONLY VALID IF (StatusFlags & ImGuiItemStatusFlags.HasClipRect) is set..
--- @field Shortcut    ImGuiKeyChord        # Shortcut at the time of submitting item. ONLY VALID IF (StatusFlags & ImGuiItemStatusFlags.HasShortcut) is set..

--- @return ImGuiLastItemData
--- @nodiscard
function ImGuiLastItemData()
    return {
        ID          = 0,
        ItemFlags   = 0,        -- See ImGuiItemFlags (called 'InFlags' before v1.91.4).
        StatusFlags = 0,        -- See ImGuiItemStatusFlags
        Rect        = ImRect(), -- Full rectangle
        NavRect     = ImRect(), -- Navigation scoring rectangle (not displayed)

        -- Rarely used fields are not explicitly cleared, only valid when the corresponding ImGuiItemStatusFlags are set.
        DisplayRect = ImRect(), -- Display rectangle. ONLY VALID IF (StatusFlags & ImGuiItemStatusFlags.HasDisplayRect) is set.
        ClipRect    = ImRect(), -- Clip rectangle at the time of submitting item. ONLY VALID IF (StatusFlags & ImGuiItemStatusFlags.HasClipRect) is set..
        Shortcut    = 0         -- Shortcut at the time of submitting item. ONLY VALID IF (StatusFlags & ImGuiItemStatusFlags.HasShortcut) is set..
    }
end

--- @param dest ImGuiLastItemData
--- @param src  ImGuiLastItemData
function ImGuiLastItemData_Copy(dest, src)
    dest.ID = src.ID
    dest.ItemFlags = src.ItemFlags
    dest.StatusFlags = src.StatusFlags
    ImRect_Copy(dest.Rect, src.Rect)
    ImRect_Copy(dest.NavRect, src.NavRect)
    ImRect_Copy(dest.DisplayRect, src.DisplayRect)
    ImRect_Copy(dest.ClipRect, src.ClipRect)
    dest.Shortcut = src.Shortcut
end

-- Store data emitted by TreeNode() for usage by TreePop()
-- - To implement ImGuiTreeNodeFlags.NavLeftJumpsToParent: store the minimum amount of data
--   which we can't infer in TreePop(), to perform the equivalent of NavApplyItemToResult().
--   Only stored when the node is a potential candidate for landing on a Left arrow jump.
--- @class ImGuiTreeNodeStackData
--- @field ID                   ImGuiID
--- @field TreeFlags            ImGuiTreeNodeFlags
--- @field ItemFlags            ImGuiItemFlags
--- @field NavRect              ImRect
--- @field DrawLinesX1          float
--- @field DrawLinesToNodesY2   float
--- @field DrawLinesTableColumn ImGuiTableColumnIdx

--- @return ImGuiTreeNodeStackData
--- @nodiscard
local function ImGuiTreeNodeStackData()
    return {
        ID                   = nil,
        TreeFlags            = nil,
        ItemFlags            = nil,      -- Used for nav landing
        NavRect              = ImRect(), -- Used for nav landing
        DrawLinesX1          = nil,
        DrawLinesToNodesY2   = nil,
        DrawLinesTableColumn = nil
    }
end

-- Storage for SetNextItem** functions
--- @class ImGuiNextItemData
--- @field HasFlags          ImGuiNextItemDataFlags
--- @field ItemFlagsSet      ImGuiItemFlags
--- @field FocusScopeId      ImGuiID
--- @field SelectionUserData any
--- @field Width             number
--- @field Shortcut          ImGuiKeyChord
--- @field ShortcutFlags     ImGuiInputFlags
--- @field OpenVal           boolean
--- @field OpenCond          ImGuiCond
--- @field RefVal            any
--- @field StorageId         ImGuiID
--- @field ColorMarker       ImU32
local IMGUI_NEXT_ITEM_DATA = {}
IMGUI_NEXT_ITEM_DATA.__index = IMGUI_NEXT_ITEM_DATA

-- Also cleared manually by ItemAdd()!
function IMGUI_NEXT_ITEM_DATA:ClearFlags()
    self.HasFlags = ImGuiNextItemDataFlags.None
    self.ItemFlagsSet = ImGuiItemFlags.None
end

--- @return ImGuiNextItemData
--- @nodiscard
function ImGuiNextItemData()
    return setmetatable({
        HasFlags          = 0, -- Called HasFlags instead of Flags to avoid mistaking this
        ItemFlagsSet      = 0, -- Currently only tested/used for ImGuiItemFlags.AllowOverlap and ImGuiItemFlags.HasSelectionUserData.

        -- Members below are NOT cleared by ItemAdd() meaning they are still valid during e.g. NavProcessItem(). Always rely on HasFlags.
        FocusScopeId      = 0,     -- Set by SetNextItemSelectionUserData()
        SelectionUserData = -1,    -- Set by SetNextItemSelectionUserData() (note that nil/0 is a valid value, we use -1 == ImGuiSelectionUserData_Invalid to mark invalid values)
        Width             = 0.0,   -- Set by SetNextItemWidth()
        Shortcut          = 0,     -- Set by SetNextItemShortcut()
        ShortcutFlags     = 0,     -- Set by SetNextItemShortcut()
        OpenVal           = false, -- Set by SetNextItemOpen()
        OpenCond          = 0,     -- Set by SetNextItemOpen()
        RefVal            = 0,     -- Not exposed yet, for ImGuiInputTextFlags.ParseEmptyAsRefVal
        StorageId         = 0,     -- Set by SetNextItemStorageID()
        ColorMarker       = 0      -- Set by SetNextItemColorMarker(). Not exposed yet, supported by DragScalar,SliderScalar and for ImGuiSliderFlags.ColorMarkers.
    }, IMGUI_NEXT_ITEM_DATA)
end

-- Storage for SetNexWindow** functions
--- @class ImGuiNextWindowData
--- @field HasFlags             ImGuiNextWindowDataFlags
--- @field PosCond              ImGuiCond
--- @field SizeCond             ImGuiCond
--- @field CollapsedCond        ImGuiCond
--- @field PosVal               ImVec2?
--- @field PosPivotVal          ImVec2?
--- @field SizeVal              ImVec2?
--- @field ContentSizeVal       ImVec2?
--- @field ScrollVal            ImVec2?
--- @field WindowFlags          ImGuiWindowFlags?
--- @field ChildFlags           ImGuiChildFlags?
--- @field CollapsedVal         boolean?
--- @field SizeConstraintRect   ImRect?
--- @field SizeCallback         function?
--- @field SizeCallbackUserData any
--- @field BgAlphaVal           number?
--- @field MenuBarOffsetMinVal  ImVec2?
--- @field RefreshFlagsVal      int?
local IMGUI_NEXT_WINDOW_DATA = {}
IMGUI_NEXT_WINDOW_DATA.__index = IMGUI_NEXT_WINDOW_DATA

function IMGUI_NEXT_WINDOW_DATA:ClearFlags()
    self.HasFlags = ImGuiNextWindowDataFlags.None
end

--- @return ImGuiNextWindowData
--- @nodiscard
function ImGuiNextWindowData()
    return setmetatable({
        HasFlags = 0,

        -- Members below are NOT cleared. Always rely on HasFlags.
        PosCond              = 0,
        SizeCond             = 0,
        CollapsedCond        = 0,
        PosVal               = ImVec2(),
        PosPivotVal          = ImVec2(),
        SizeVal              = ImVec2(),
        ContentSizeVal       = ImVec2(),
        ScrollVal            = ImVec2(),
        WindowFlags          = nil,
        ChildFlags           = nil,
        WindowFlagsSet       = 0, -- Flags to set. Use SetNextWindowFlags()!
        WindowFlagsClear     = 0,
        ChildFlagsSet        = 0, -- Flags to set. Use SetNextWindowChildFlags().
        ChildFlagsClear      = 0,
        ViewportId           = 0,
        DockId               = 0,
        DockCond             = 0,
        PosUndock            = false,
        WindowClass          = nil,
        CollapsedVal         = nil,
        SizeConstraintRect   = nil,
        SizeCallback         = nil,
        SizeCallbackUserData = nil,
        BgAlphaVal           = nil, -- Override background alpha
        MenuBarOffsetMinVal  = ImVec2(), -- (Always on) This is not exposed publicly, so we don't clear it and it doesn't have a corresponding flag (could we? for consistency?)
        RefreshFlagsVal      = nil,
        CacheKeySet          = false, -- [Port] SetNextWindowCached()
        CacheKeyVal          = nil
    }, IMGUI_NEXT_WINDOW_DATA)
end

--- @enum ImGuiWindowBgClickFlags
ImGuiWindowBgClickFlags = {
    None = 0,
    Move = bitLShift(1, 0), -- Click on bg/void + drag to move window. Cleared by default when using io.ConfigWindowsMoveFromTitleBarOnly.
}

--- @enum ImGuiNextWindowDataFlags
ImGuiNextWindowDataFlags = {
    None              = 0,
    HasPos            = bitLShift(1, 0),
    HasSize           = bitLShift(1, 1),
    HasContentSize    = bitLShift(1, 2),
    HasCollapsed      = bitLShift(1, 3),
    HasSizeConstraint = bitLShift(1, 4),
    HasFocus          = bitLShift(1, 5),
    HasBgAlpha        = bitLShift(1, 6),
    HasScroll         = bitLShift(1, 7),
    HasWindowFlags    = bitLShift(1, 8),
    HasChildFlags     = bitLShift(1, 9),
    HasRefreshPolicy  = bitLShift(1, 10),
    HasViewport       = bitLShift(1, 11),
    HasDock           = bitLShift(1, 12),
    HasWindowClass    = bitLShift(1, 13)
}

-- FIXME: this is in development, not exposed/functional as a generic feature yet.
-- Horizontal/Vertical enums are fixed to 0/1 so they may be used to index ImVec2
--- @enum ImGuiLayoutType
ImGuiLayoutType =
{
    Horizontal = 0,
    Vertical   = 1
}

--- @enum ImGuiSeparatorFlags
ImGuiSeparatorFlags =
{
    None           = 0,
    Horizontal     = bitLShift(1, 0), -- Axis default to current layout type, so generally Horizontal unless e.g. in a menu bar
    Vertical       = bitLShift(1, 1),
    SpanAllColumns = bitLShift(1, 2)  -- Make separator cover all columns of a legacy Columns() set.
}

--- @class ImGuiStyle
MT.ImGuiStyle = {}
MT.ImGuiStyle.__index = MT.ImGuiStyle

--- @return ImGuiStyle
--- @nodiscard
function ImGuiStyle()
    --- @type ImGuiStyle
    local this = {
        FontSizeBase  = 0.0, -- Will default to io.Fonts.Fonts[0] on first frame.
        FontScaleMain = 1.0, -- Main scale factor. May be set by application once, or exposed to end-user.
        FontScaleDpi  = 1.0, -- Additional scale factor from viewport/monitor contents scale. When io.ConfigDpiScaleFonts is enabled, this is automatically overwritten when changing monitor DPI.

        Alpha = 1.0, -- Global alpha applies to everything in Dear ImGui.
        DisabledAlpha = 0.60, -- Additional alpha multiplier applied by BeginDisabled(). Multiply over current value of Alpha.

        FramePadding = ImVec2(4, 3), -- Padding within a framed rectangle (used by most widgets)
        FrameRounding = 0.0, -- Radius of frame corners rounding. Set to 0.0 to have rectangular frames (used by most widgets).
        FrameBorderSize = 0.0, -- Thickness of border around frames. Generally set to 0.0 or 1.0. Other values not well tested.
        WindowPadding = ImVec2(8, 8), -- Padding within a window

        TouchExtraPadding = ImVec2(0, 0), -- Expand reactive bounding box for touch-based system where touch position is not accurate enough. Unfortunately we don't sort widgets so priority on overlap will always be given to the first widget. So don't grow this too much!
        IndentSpacing = 21.0, -- Horizontal spacing when e.g. entering a tree node. Generally == (FontSize + FramePadding.x*2).

        WindowRounding = 0, -- Radius of window corners rounding. Set to 0.0 to have rectangular windows. Large values tend to lead to variety of artifacts and are not recommended.
        WindowBorderSize = 1, -- Thickness of border around windows. Generally set to 0.0 or 1.0. Other values not well tested.

        ScrollbarSize     = 14.0, -- Width of the vertical scrollbar, Height of the horizontal scrollbar
        ScrollbarRounding = 9.0, -- Radius of grab corners rounding for scrollbar
        ScrollbarPadding  = 2.0, -- Padding of scrollbar grab within its frame (same for both axes)
        GrabMinSize = 12.0, -- Minimum width/height of a grab box for slider/scrollbar
        GrabRounding = 0.0, -- Radius of grabs corners rounding. Set to 0.0 to have rectangular slider grabs.
        ImageRounding = 0.0, -- Rounding of Image() calls.
        ImageBorderSize = 0.0, -- Thickness of border around Image() calls.

        WindowBorderHoverPadding = 4.0, -- Hit-testing extent outside/inside resizing border. Also extend determination of hovered window. Generally meaningfully larger than WindowBorderSize to make it easy to reach borders.

        TreeLinesFlags = ImGuiTreeNodeFlags.DrawLinesNone,
        TreeLinesSize  = 1.0, -- Thickness of outlines when using ImGuiTreeNodeFlags.DrawLines.
        TreeLinesRounding = 0.0, -- Radius of lines connecting child nodes to the vertical line.
        MenuItemRounding = 0.0, -- Radius of MenuItem, BeginMenu rounding.
        SelectableRounding = 0.0, -- Radius of selectable rounding. MODIFYING THIS IS DISCOURAGED. CONTIGUOUS SELECTIONS WILL NOT LOOK RIGHT. (#7589)

        ColorMarkerSize = 3.0, -- Size of R/G/B/A color markers for ColorEdit4() and for Drags/Sliders when using ImGuiSliderFlags.ColorMarkers.
        ColorButtonPosition = ImGuiDir.Right, -- Side of the color button in the ColorEdit4 widget (left/right). Defaults to ImGuiDir.Right.

        InputTextCursorSize = 1.0, -- Thickness of cursor/caret in InputText().
        SeparatorSize           = 1.0, -- Thickness of border in Separator().
        SeparatorTextBorderSize = 3.0, -- Thickness of border in SeparatorText().
        SeparatorTextAlign      = ImVec2(0.0, 0.5), -- Alignment of text within the separator. Defaults to (0.0, 0.5) (left aligned, center).
        SeparatorTextPadding    = ImVec2(20.0, 3.0), -- Horizontal offset of text from each edge of the separator + spacing on other axis. Generally small values. .y is recommended to be == FramePadding.y.

        DisplaySafeAreaPadding = ImVec2(3, 3), -- If you cannot see the edge of your screen (e.g. on a TV) increase the safe area padding. Covers popups/tooltips as well regular windows.
        DisplayWindowPadding = ImVec2(19, 19), -- Window position are clamped to be visible within the display area or monitors by at least this amount. Only applies to regular windows.

        -- Rendering & Tessellation
        AntiAliasedLines = true, -- Enable anti-aliased lines/borders. Used at the beginning of the frame to set ImDrawListFlags.AntiAliasedLines in all draw-lists.
        AntiAliasedLinesUseTex = true, -- Enable anti-aliased lines/borders using textures for legacy strokes. Require backend to render with bilinear filtering (NOT point/nearest filtering).
        AntiAliasedFill = true, -- Enable anti-aliased edges around filled shapes (rounded rectangles, circles, etc.). Used at the beginning of the frame to set ImDrawListFlags.AntiAliasedFill in all draw-lists.

        CurveTessellationTol       = 1.25, -- Tessellation tolerance when using PathBezierCurveTo() without a specific number of segments. Decrease for highly tessellated curves (higher quality, more polygons), increase to reduce quality.
        CircleTessellationMaxError = 0.30, -- Maximum error (in pixels) allowed when using AddCircle()/AddCircleFilled() or drawing rounded corner rectangles with no explicit segment count specified. Decrease for higher quality but more geometry.

        -- Behaviors
        HoverStationaryDelay = 0.15, -- Delay for IsItemHovered(ImGuiHoveredFlags.Stationary). Time required to consider mouse stationary.
        HoverDelayShort = 0.15, -- Delay for IsItemHovered(ImGuiHoveredFlags.DelayShort). Usually used along with HoverStationaryDelay.
        HoverDelayNormal = 0.40, -- Delay for IsItemHovered(ImGuiHoveredFlags.DelayNormal). "

        Colors = {},

        ButtonTextAlign = ImVec2(0.5, 0.5), -- Alignment of button text when button is larger than text.
        SelectableTextAlign = ImVec2(0.0, 0.0), -- Alignment of selectable text. Defaults to (0.0, 0.0) (top-left aligned). It's generally important to keep this left-aligned if you want to lay multiple items on a same line.

        WindowMinSize = ImVec2(32, 32), -- Minimum window size
        WindowTitleAlign = ImVec2(0.0, 0.5), -- Alignment for title bar text
        WindowMenuButtonPosition = ImGuiDir.Left, -- Position of the collapsing/docking button in the title bar (left/right). Defaults to ImGuiDir.Left.
        ChildRounding = 0.0, -- Radius of child window corners rounding. Set to 0.0 to have rectangular child windows
        ChildBorderSize = 1.0, -- Thickness of border around child windows. Generally set to 0.0 or 1.0. Other values not well tested.
        PopupRounding = 0.0, -- Radius of popup window corners rounding. Set to 0.0 to have rectangular child windows
        PopupBorderSize = 1.0, -- Thickness of border around popup or tooltip windows. Generally set to 0.0 or 1.0. Other values not well tested.

        DockingSeparatorSize = 2.0, -- Thickness of resizing border between docked windows
        DockingNodeHasCloseButton = true, -- Docking nodes have their own CloseButton() to close all docked windows.
        MouseCursorScale = 1.0, -- Scale software rendered mouse cursor (when io.MouseDrawCursor is enabled). May be removed later.

        ItemSpacing = ImVec2(8, 4), -- Horizontal and vertical spacing between widgets/lines
        ItemInnerSpacing = ImVec2(4, 4), -- Horizontal and vertical spacing between within elements of a composed widget (e.g. a slider and its label)
        CellPadding = ImVec2(4, 2), -- Padding within a table cell. Cellpadding.x is locked for entire table. CellPadding.y may be altered between different rows.

        ColumnsMinSpacing = 6.0, -- Minimum horizontal spacing between two columns. Preferably > (FramePadding.x + 1).

        LogSliderDeadzone = 4.0, -- The size in pixels of the dead-zone around zero on logarithmic sliders that cross zero.

        TabRounding = 5.0, -- Radius of upper corners of a tab. Set to 0.0 to have rectangular tabs.
        TabBorderSize = 0.0, -- Thickness of border around tabs.
        TabMinWidthBase = 1.0, -- Minimum tab width, to make tabs larger than their contents. TabBar buttons are not affected.
        TabMinWidthShrink = 80.0, -- Minimum tab width after shrinking, when using ImGuiTabBarFlags.FittingPolicyMixed policy. FLT_MAX: never shrink, will behave like ImGuiTabBarFlags.FittingPolicyScroll.
        TabCloseButtonMinWidthSelected = -1.0, -- -1: always visible. 0.0: visible when hovered. >0.0: visible when hovered if minimum width.
        TabCloseButtonMinWidthUnselected = 0.0, -- -1: always visible. 0.0: visible when hovered. >0.0: visible when hovered if minimum width. FLT_MAX: never show close button when unselected.
        TabBarBorderSize = 1.0, -- Thickness of tab-bar separator, which takes on the tab active color to denote focus.
        TabBarOverlineSize = 1.0, -- Thickness of tab-bar overline, which highlights the selected tab-bar.
        TableAngledHeadersAngle = 35.0 * (IM_PI / 180.0), -- Angle of angled headers (supported values range from -50 degrees to +50 degrees).
        TableAngledHeadersTextAlign = ImVec2(0.5, 0.0), -- Alignment of angled headers within the cell

        DragDropTargetRounding = 0.0, -- Radius of the drag and drop target frame.
        DragDropTargetBorderSize = 2.0, -- Thickness of the drag and drop target border.
        DragDropTargetPadding = 3.0, -- Size to expand the drag and drop target from actual target item size.

        HoverFlagsForTooltipMouse = bitOr(ImGuiHoveredFlags.Stationary, ImGuiHoveredFlags.DelayShort, ImGuiHoveredFlags.AllowWhenDisabled), -- Default flags when using IsItemHovered(ImGuiHoveredFlags.ForTooltip) or BeginItemTooltip()/SetItemTooltip() while using mouse.
        HoverFlagsForTooltipNav = bitOr(ImGuiHoveredFlags.NoSharedDelay, ImGuiHoveredFlags.DelayNormal, ImGuiHoveredFlags.AllowWhenDisabled), -- Default flags when using IsItemHovered(ImGuiHoveredFlags.ForTooltip) or BeginItemTooltip()/SetItemTooltip() while using keyboard/gamepad.

        -- [Internal]
        _MainScale = 1.0,
        _NextFrameFontSizeBase = 0.0
    }

    -- Default theme
    ImGui.StyleColorsDark(this)

    setmetatable(this, MT.ImGuiStyle)

    return this
end

-- Storage for each window pushed into the stack.
--- @class ImGuiWindowStackData

--- @return ImGuiWindowStackData
--- @nodiscard
function ImGuiWindowStackData()
    return {
        Window                              = nil,
        ParentLastItemDataBackup            = ImGuiLastItemData(),
        StackSizesInBegin                   = nil, -- Store size of various stacks for asserting
        DisabledOverrideReenable            = nil, -- Non-child window override disabled flag
        DisabledOverrideReenableAlphaBackup = nil
    }
end

-- Storage data for BeginComboPreview()/EndComboPreview()
--- @class ImGuiComboPreviewData
--- @field PreviewRect                  ImRect
--- @field BackupCursorPos              ImVec2
--- @field BackupCursorMaxPos           ImVec2
--- @field BackupCursorPosPrevLine      ImVec2
--- @field BackupPrevLineTextBaseOffset float
--- @field BackupLayout                 ImGuiLayoutType

--- @return ImGuiComboPreviewData
--- @nodiscard
local function ImGuiComboPreviewData()
    return {
        PreviewRect                  = ImRect(),
        BackupCursorPos              = ImVec2(),
        BackupCursorMaxPos           = ImVec2(),
        BackupCursorPosPrevLine      = ImVec2(),
        BackupPrevLineTextBaseOffset = 0.0,
        BackupLayout                 = 0
    }
end

--- @alias IMSTB_TEXTEDIT_STRING ImGuiInputTextState

--- @alias ImStbTexteditState STB_TexteditState

-- Internal state of the currently focused/edited text input box
-- For a given item ID, access with ImGui.GetInputTextState()
--- @class ImGuiInputTextState
--- @field Ctx                  ImGuiContext        # parent UI context (needs to be set explicitly by parent)
--- @field Stb                  ImStbTexteditState  # State for stb_textedit.lua
--- @field Flags                ImGuiInputTextFlags # copy of InputText() flags. may be used to check if e.g. ImGuiInputTextFlags.Password is set.
--- @field ID                   ImGuiID             # widget id owning the text state
--- @field TextLen              int                 # UTF-8 length of the string in TextA (in bytes)
--- @field TextSrc              ImStringBuffer      # == TextA.Data unless read-only, in which case == buf passed to InputText(). For _ReadOnly fields, pointer will be null outside the InputText() call
--- @field TextA                ImVector<char>      # main UTF8 buffer. TextA.Size is a buffer size! Should always be >= buf_size passed by user (and of course >= CurLenA + 1)
--- @field TextToRevertTo       ImVector<char>      # value to revert to when pressing Escape = backup of end-user buffer at the time of focus (in UTF-8, unaltered)
--- @field CallbackTextBackup   ImVector<char>      # temporary storage for callback to support automatic reconcile of undo-stack
--- @field BufCapacity          int                 # end-user buffer capacity (include zero terminator)
--- @field Scroll               ImVec2              # horizontal offset (managed manually) + vertical scrolling (pulled from child window's own Scroll.y)
--- @field LineCount            int                 # last line count (solely for debugging)
--- @field WrapWidth            float               # word-wrapping width
--- @field CursorAnim           float               # timer for cursor blink, reset on every user action so the cursor reappears immediately
--- @field CursorFollow         bool                # set when we want scrolling to follow the current cursor position (not always!)
--- @field CursorCenterY        bool                # set when we want scrolling to be centered over the cursor position (while resizing a word-wrapping field)
--- @field SelectedAllMouseLock bool                # after a double-click to select all, we ignore further mouse drags to update selection
--- @field EditedBefore         bool                # edited since activated
--- @field EditedThisFrame      bool                # edited this frame
MT.ImGuiInputTextState = {}
MT.ImGuiInputTextState.__index = MT.ImGuiInputTextState

local function ImGuiInputTextState()
    local this = {
        Ctx   = nil, -- parent UI context (needs to be set explicitly by parent).
        Stb   = STB_TexteditState(), -- FIXME: no global! -- State for stb_textedit.h
        Flags = 0, -- copy of InputText() flags. may be used to check if e.g. ImGuiInputTextFlags.Password is set.
        ID    = 0, -- widget id owning the text state

        TextLen            = 0,          -- UTF-8 length of the string in TextA (in bytes)
        TextSrc            = nil,        -- == TextA.Data unless read-only, in which case == buf passed to InputText(). For _ReadOnly fields, pointer will be null outside the InputText() call.
        TextA              = ImVector(), -- main UTF8 buffer. TextA.Size is a buffer size! Should always be >= buf_size passed by user (and of course >= CurLenA + 1).
        TextToRevertTo     = ImVector(), -- value to revert to when pressing Escape = backup of end-user buffer at the time of focus (in UTF-8, unaltered)
        CallbackTextBackup = ImVector(), -- temporary storage for callback to support automatic reconcile of undo-stack

        BufCapacity = 0,        -- end-user buffer capacity (include zero terminator)
        Scroll      = ImVec2(), -- horizontal offset (managed manually) + vertical scrolling (pulled from child window's own Scroll.y)
        LineCount   = 0,        -- last line count (solely for debugging)
        WrapWidth   = 0.0,      -- word-wrapping width

        CursorAnim    = 0.0,   -- timer for cursor blink, reset on every user action so the cursor reappears immediately
        CursorFollow  = false, -- set when we want scrolling to follow the current cursor position (not always!)
        CursorCenterY = false, -- set when we want scrolling to be centered over the cursor position (while resizing a word-wrapping field)
        SelectedAllMouseLock = false, -- after a double-click to select all, we ignore further mouse drags to update selection
        EditedBefore = false,    -- edited since activated
        EditedThisFrame = false, -- edited this frame
    }

    return setmetatable(this, MT.ImGuiInputTextState)
end

-- Internal temporary state for deactivating InputText() instances.
-- Store as part of ImGuiDeactivatedItemData?
--- @class ImGuiInputTextDeactivatedState
--- @field ID          ImGuiID        # widget id owning the text state (which just got deactivated)
--- @field ElapseFrame int
--- @field TextA       ImVector<char> # text buffer
local IMGUI_INPUT_TEXT_DEACTIVATED_STATE = {}
IMGUI_INPUT_TEXT_DEACTIVATED_STATE.__index = IMGUI_INPUT_TEXT_DEACTIVATED_STATE

function IMGUI_INPUT_TEXT_DEACTIVATED_STATE:ClearFreeMemory()
    self.ID = 0
    self.ElapseFrame = 0
    self.TextA:clear()
end

--- @return ImGuiInputTextDeactivatedState
--- @nodiscard
local function ImGuiInputTextDeactivatedState()
    return setmetatable({
        ID          = 0,         -- widget id owning the text state (which just got deactivated)
        ElapseFrame = 0,
        TextA       = ImVector() -- text buffer
    }, IMGUI_INPUT_TEXT_DEACTIVATED_STATE)
end

--- @alias ImGuiKeyRoutingIndex ImS16

-- Routing table entry (sizeof() == 16 bytes)
--- @class ImGuiKeyRoutingData
--- @field NextEntryIndex   ImGuiKeyRoutingIndex
--- @field Mods             ImU16 # Technically we'd only need 4-bits but for simplify we store ImGuiMod_ values which need 16-bits.
--- @field RoutingCurrScore ImU16 # [DEBUG] For debug display
--- @field RoutingNextScore ImU16 # Lower is better (0: perfect score)
--- @field RoutingCurr      ImGuiID
--- @field RoutingNext      ImGuiID

--- @return ImGuiKeyRoutingData
--- @nodiscard
function ImGuiKeyRoutingData()
    return {
        NextEntryIndex = -1,
        Mods = 0, -- Technically we'd only need 4-bits but for simplify we store ImGuiMod_ values which need 16-bits.
        RoutingCurrScore = 0, -- [DEBUG] For debug display
        RoutingNextScore = 0, -- Lower is better (0: perfect score)
        RoutingCurr = ImGuiKeyOwner_NoOwner,
        RoutingNext = ImGuiKeyOwner_NoOwner
    }
end

-- Routing table: maintain a desired owner for each possible key-chord (key + mods), and setup owner in NewFrame() when mods are matching.
-- Stored in main context (1 instance)
--- @class ImGuiKeyRoutingTable
--- @field Index       ImGuiKeyRoutingIndex[] # Index of first entry in Entries[]
--- @field Entries     ImVector<ImGuiKeyRoutingData>
--- @field EntriesNext ImVector<ImGuiKeyRoutingData> # Double-buffer to avoid reallocation (could use a shared buffer)
local _ImGuiKeyRoutingTable = {}
_ImGuiKeyRoutingTable.__index = _ImGuiKeyRoutingTable

function _ImGuiKeyRoutingTable:Clear()
    for n = 1, ImGuiKey.NamedKey_COUNT do self.Index[n] = -1 end
    self.Entries:clear()
    self.EntriesNext:clear()
end

--- @return ImGuiKeyRoutingTable
local function ImGuiKeyRoutingTable()
    local this = setmetatable({
        Index       = {}, -- Index of first entry in Entries[]
        Entries     = ImVector(),
        EntriesNext = ImVector() -- Double-buffer to avoid reallocation (could use a shared buffer)
    }, _ImGuiKeyRoutingTable)

    this:Clear()

    return this
end

-- Helper: ImGuiTextIndex
-- Maintain a line index for a text buffer. This is a strong candidate to be moved into the public API.
--- @class ImGuiTextIndex
--- @field Offsets   ImVector<int>
--- @field EndOffset int # Because we don't own text buffer we need to maintain EndOffset (may bake in LineOffsets?)
local IMGUI_TEXT_INDEX = {}
IMGUI_TEXT_INDEX.__index = IMGUI_TEXT_INDEX

function IMGUI_TEXT_INDEX:clear() self.Offsets:clear(); self.EndOffset = 0; end

function IMGUI_TEXT_INDEX:get_line_begin(base, n)
    return base + (self.Offsets.Size ~= 0 and self.Offsets[n] or 0)
end

function IMGUI_TEXT_INDEX:get_line_end(base, n)
    return base + ((n + 1 < self.Offsets.Size) and (self.Offsets[n + 1] - 1) or self.EndOffset)
end

--- @return ImGuiTextIndex
local function ImGuiTextIndex()
    return setmetatable({ Offsets = ImVector(), EndOffset = 0 }, IMGUI_TEXT_INDEX)
end

--- @class ImGuiDebugAllocEntry
--- @field FrameCount int
--- @field AllocCount int
--- @field FreeCount  int

--- @return ImGuiDebugAllocEntry
local function ImGuiDebugAllocEntry()
    return { FrameCount = 0, AllocCount = 0, FreeCount = 0 }
end

--- @class ImGuiDebugAllocInfo
--- @field TotalAllocCount int # Number of call to MemAlloc().
--- @field TotalFreeCount  int
--- @field LastEntriesIdx  ImS16 # Current index in buffer
--- @field LastEntriesBuf  ImGuiDebugAllocEntry[] # Track last 6 frames that had allocations

--- @return ImGuiDebugAllocInfo
local function ImGuiDebugAllocInfo()
    local this = {
        TotalAllocCount = 0, -- Number of call to MemAlloc().
        TotalFreeCount = 0,
        LastEntriesIdx = 1, -- Current index in buffer
        LastEntriesBuf = {nil, nil, nil, nil, nil, nil}, -- Track last 6 frames that had allocations
    }

    for i = 1, 6 do
        this.LastEntriesBuf[i] = ImGuiDebugAllocEntry()
    end

    return this
end

--- @class ImGuiMetricsConfig

--- @return ImGuiMetricsConfig
local function ImGuiMetricsConfig()
    return
    {
        HighlightMonitorIdx = -1,
        HighlightViewportID = 0,
    }
end

-- Storage for navigation query/results
--- @class ImGuiNavItemData
--- @field Window             ImGuiWindow?           # Init,Move -- Best candidate window (result->ItemWindow->RootWindowForNav == request->Window)
--- @field ID                 ImGuiID                # Init,Move -- Best candidate item ID
--- @field FocusScopeId       ImGuiID                # Init,Move -- Best candidate focus scope ID
--- @field RectRel            ImRect                 # Init,Move -- Best candidate bounding box in window relative space
--- @field ItemFlags          ImGuiItemFlags         # ????,Move -- Best candidate item flags
--- @field SelectionUserData  ImGuiSelectionUserData # I+Mov -- Best candidate SetNextItemSelectionUserData() value. Valid if (ItemFlags & ImGuiItemFlags.HasSelectionUserData)
--- @field DistBox            float                  # Move -- Best candidate box distance to current NavId
--- @field DistCenter         float                  # Move -- Best candidate center distance to current NavId
--- @field DistAxial          float                  # Move -- Best candidate axial distance to current NavId
local IMGUI_NAV_ITEM_DATA = {}
IMGUI_NAV_ITEM_DATA.__index = IMGUI_NAV_ITEM_DATA

function IMGUI_NAV_ITEM_DATA:Clear()
    self.Window             = nil
    self.ID                 = 0
    self.FocusScopeId       = 0
    self.ItemFlags          = 0
    self.SelectionUserData  = ImGuiSelectionUserData_Invalid
    self.DistBox    = FLT_MAX
    self.DistCenter = FLT_MAX
    self.DistAxial  = FLT_MAX
end

--- @return ImGuiNavItemData
local function ImGuiNavItemData()
    local this = setmetatable({ }, IMGUI_NAV_ITEM_DATA)
    this.RectRel = ImRect()
    this:Clear()
    return this
end

-------------------------------------------------------------------------------
-- [SECTION] ImGuiContext (main Dear ImGui context)
-------------------------------------------------------------------------------

--- @class ImGuiContext
--- @field Initialized                        bool
--- @field WithinFrameScope                   bool # Set by NewFrame(), cleared by EndFrame()
--- @field WithinFrameScopeWithImplicitWindow bool # Set by NewFrame(), cleared by EndFrame() when the implicit debug window has been pushed
--- @field FrameCount                         int
--- @field FrameCountEnded                    int
--- @field CurrentWindow                      ImGuiWindow
--- @field HoveredWindow                      ImGuiWindow
--- @field Style                              ImGuiStyle
--- @field FontAtlases                        ImVector<ImFontAtlas>
--- @field Font                               ImFont
--- @field FontBaked                          ImFontBaked?
--- @field FontSize                           float
--- @field FontSizeBase                       float
--- @field FontBakedScale                     float
--- @field FontRasterizerDensity              float
--- @field DrawListSharedData                 ImDrawListSharedData
--- @field NextItemData                       ImGuiNextItemData
--- @field LastItemData                       ImGuiLastItemData
--- @field NextWindowData                     ImGuiNextWindowData
--- @field WithinEndChildID                   ImGuiID
--- @field WithinEndPopupID                   ImGuiID
--- @field StyleVarStack                      ImVector
--- @field AnyIdHasBeenEditedThisFrame        bool
--- @field ActiveId                           ImGuiID
--- @field ActiveIdMouseButton                ImS8
--- @field Windows                            ImVector<ImGuiWindow>
--- @field WindowsFocusOrder                  ImVector<ImGuiWindow>
--- @field WindowsTempSortBuffer              ImVector<ImGuiWindow>
--- @field CurrentWindowStack                 ImVector<ImGuiWindowStackData>
--- @field FocusScopeStack                    ImVector<ImGuiFocusScopeData>
--- @field ItemFlagsStack                     ImVector<ImGuiItemFlags>
--- @field GroupStack                         ImVector<ImGuiGroupData>
--- @field OpenPopupStack                     ImVector<ImGuiPopupData>
--- @field BeginPopupStack                    ImVector<ImGuiPopupData>
--- @field TreeNodeStack                      ImVector<ImGuiTreeNodeStackData>
--- @field IO                                 ImGuiIO
--- @field PlatformIO                         ImGuiPlatformIO
--- @field Viewports                          ImVector<ImGuiViewportP>
--- @field DebugLogFlags                      ImGuiDebugLogFlags
--- @field DebugFlashStyleColorIdx            ImGuiCol
--- @field ColorEditCurrentID                 ImGuiID                        # Set temporarily while inside of the parent-most ColorEdit4/ColorPicker4 (because they call each others)
--- @field ColorEditSavedID                   ImGuiID                        # ID we are saving/restoring HS for
--- @field ColorEditSavedHue                  float                          # Backup of last Hue associated to LastColor, so we can restore Hue in lossy RGB<>HSV round trips
--- @field ColorEditSavedSat                  float                          # Backup of last Saturation associated to LastColor, so we can restore Saturation in lossy RGB<>HSV round trips
--- @field ColorEditSavedColor                ImU32                          # RGB value with alpha set to 0
--- @field ColorPickerRef                     ImVec4                         # Initial/reference color at the time of opening the color picker
--- @field MenusIdSubmittedThisFrame          ImVector<ImGuiID>
--- @field InputTextState                     ImGuiInputTextState
--- @field InputTextLineIndex                 ImGuiTextIndex
--- @field InputTextDeactivatedState          ImGuiInputTextDeactivatedState
--- @field InputTextPasswordFontBackupBaked   ImFontBaked
--- @field KeysMayBeCharInput                 ImBitArrayForNamedKeys
--- @field KeysOwnerData                      ImGuiKeyOwnerData[]
--- @field KeysRoutingTable                   ImGuiKeyRoutingTable
--- @field NavFocusRoute                      ImVector<ImGuiFocusScopeData>
--- @field PlatformImeData                    ImGuiPlatformImeData
--- @field PlatformImeDataPrev                ImGuiPlatformImeData
--- @field UserTextures                       ImVector<ImTextureData>
--- @field DebugMetricsConfig                 ImGuiMetricsConfig
--- @field DebugAllocInfo                     ImGuiDebugAllocInfo
--- @field TempBuffer                         ImVector<char>

-------------------------------------------------------------------------------
-- [SECTION] Tab bar, Tab item support
-- PORT: public flags from imgui.h + private extensions
-------------------------------------------------------------------------------

-- Flags for ImGui.BeginTabBar()
--- @enum ImGuiTabBarFlags
ImGuiTabBarFlags = {
    None                         = 0,
    Reorderable                  = bitLShift(1, 0), -- Allow manually dragging tabs to re-order them + New tabs are appended at the end of list
    AutoSelectNewTabs            = bitLShift(1, 1), -- Automatically select new tabs when they appear
    TabListPopupButton           = bitLShift(1, 2), -- Disable buttons to open the tab list popup
    NoCloseWithMiddleMouseButton = bitLShift(1, 3), -- Disable behavior of closing tabs (that are submitted with p_open ~= nil) with middle mouse button. You may handle this behavior manually on user's side with if (IsItemHovered() && IsMouseClicked(2)) p_open = false.
    NoTabListScrollingButtons    = bitLShift(1, 4), -- Disable scrolling buttons (apply when fitting policy is ImGuiTabBarFlags.FittingPolicyScroll)
    NoTooltip                    = bitLShift(1, 5), -- Disable tooltips when hovering a tab
    DrawSelectedOverline         = bitLShift(1, 6), -- Draw selected overline markers over selected tab

    -- Fitting/Resize policy
    FittingPolicyMixed           = bitLShift(1, 7), -- Shrink down tabs when they don't fit, until width is style.TabMinWidthShrink, then enable scrolling. Setting TabMinWidthShrink to FLT_MAX makes this behave like ImGuiTabBarFlags.FittingPolicyScroll.
    FittingPolicyShrink          = bitLShift(1, 8), -- Shrink down tabs when they don't fit
    FittingPolicyScroll          = bitLShift(1, 9), -- Enable scrolling buttons when tabs don't fit
    -- Private
    DockNode                     = bitLShift(1, 20), -- Part of a dock node [we don't use this in the master branch but it facilitate branch syncing to keep this around]
    IsFocused                    = bitLShift(1, 21),
    SaveSettings                 = bitLShift(1, 22), -- FIXME: Settings are handled by the docking system, this only request the tab bar to mark settings dirty when reordering tabs
}
ImGuiTabBarFlags.FittingPolicyMask_       = bitOr(ImGuiTabBarFlags.FittingPolicyMixed, ImGuiTabBarFlags.FittingPolicyShrink, ImGuiTabBarFlags.FittingPolicyScroll)
ImGuiTabBarFlags.FittingPolicyDefault_    = ImGuiTabBarFlags.FittingPolicyMixed
ImGuiTabBarFlags.FittingPolicyResizeDown  = ImGuiTabBarFlags.FittingPolicyShrink -- Renamed in 1.92.2

-- Flags for ImGui.BeginTabItem()
--- @enum ImGuiTabItemFlags
ImGuiTabItemFlags = {
    None                         = 0,
    UnsavedDocument              = bitLShift(1, 0), -- Display a dot next to the title + set ImGuiTabItemFlags.NoAssumedClosure.
    SetSelected                  = bitLShift(1, 1), -- Trigger flag to programmatically make the tab selected when calling BeginTabItem()
    NoCloseWithMiddleMouseButton = bitLShift(1, 2), -- Disable behavior of closing tabs (that are submitted with p_open ~= nil) with middle mouse button. You may handle this behavior manually on user's side with if (IsItemHovered() && IsMouseClicked(2)) p_open = false.
    NoPushId                     = bitLShift(1, 3), -- Don't call PushID()/PopID() on BeginTabItem()/EndTabItem()
    NoTooltip                    = bitLShift(1, 4), -- Disable tooltip for the given tab
    NoReorder                    = bitLShift(1, 5), -- Disable reordering this tab or having another tab cross over this tab
    Leading                      = bitLShift(1, 6), -- Enforce the tab position to the left of the tab bar (after the tab list popup button)
    Trailing                     = bitLShift(1, 7), -- Enforce the tab position to the right of the tab bar (before the scrolling buttons)
    NoAssumedClosure             = bitLShift(1, 8), -- Tab is selected when trying to close + closure is not immediately assumed (will wait for user to stop submitting the tab). Otherwise closure is assumed when pressing the X, so if you keep submitting the tab may reappear at end of tab bar.
    -- Private
    NoCloseButton                = bitLShift(1, 20), -- Track whether p_open was set or not (we'll need this info on the next frame to recompute ContentWidth during layout)
    Button                       = bitLShift(1, 21), -- Used by TabItemButton, change the tab item behavior to mimic a button
    Invisible                    = bitLShift(1, 22), -- To reserve space e.g. with ImGuiTabItemFlags.Leading
    Unsorted                     = bitLShift(1, 23), -- [Docking] Trailing tabs with the _Unsorted flag will be sorted based on the DockOrder of their Window.
}
ImGuiTabItemFlags.SectionMask_ = bitOr(ImGuiTabItemFlags.Leading, ImGuiTabItemFlags.Trailing)

-- Storage for one active tab item. In this port the label is stored in `Name` (C++ uses NameOffset into TabBar.TabsNames)
--- @class ImGuiTabItem
--- @return ImGuiTabItem
function ImGuiTabItem()
    return {
        ID = 0, Flags = 0, Window = nil, -- Window: When TabItem is part of a DockNode's TabBar, we hold on to a window.
        LastFrameVisible = -1, LastFrameSelected = -1, -- LastFrameSelected: This allows us to infer an ordered list of the last activated tabs with little maintenance
        -- Offset: Position relative to beginning of tab bar
        -- Width: Width currently displayed
        -- ContentWidth: Width of label + padding, stored during BeginTabItem() call (misnamed as "Content" would normally imply width of label only)
        -- RequestedWidth: Width optionally requested by caller, -1.0 is unused
        Offset = 0.0, Width = 0.0, ContentWidth = 0.0, RequestedWidth = -1.0,
        NameOffset = -1, Name = nil,
        BeginOrder = -1,        -- 0-based -- BeginTabItem() order, used to re-order tabs after toggling ImGuiTabBarFlags.Reorderable
        IndexDuringLayout = -1, -- 0-based -- Index only used during TabBarLayout(). Tabs gets reordered so 'Tabs[n].IndexDuringLayout == n' but may mismatch during additions.
        WantClose = false, -- Marked as closed by SetTabItemClosed()
    }
end

-- Storage for a tab bar. Tabs: ImVector of ImGuiTabItem tables (references; "pointers" stay valid across reorders)
--- @class ImGuiTabBar
--- @return ImGuiTabBar
function ImGuiTabBar()
    return {
        Window = nil, Tabs = ImVector(), Flags = 0, ID = 0, -- ID: Zero for tab-bars used by docking
        -- SelectedTabId: Selected tab/window
        -- NextSelectedTabId: Next selected tab/window. Will also trigger a scrolling animation
        -- VisibleTabId: Can occasionally be != SelectedTabId (e.g. when previewing contents for Ctrl+Tab preview)
        SelectedTabId = 0, NextSelectedTabId = 0, NextScrollToTabId = 0, VisibleTabId = 0,
        CurrFrameVisible = -1, PrevFrameVisible = -1,
        BarRect = ImRect(), BarRectPrevWidth = 0.0, -- BarRectPrevWidth: Backup of previous width. When width change we enforce keep horizontal scroll on focused tab.
        CurrTabsContentsHeight = 0.0, PrevTabsContentsHeight = 0.0, -- PrevTabsContentsHeight: Record the height of contents submitted below the tab bar
        -- WidthAllTabs: Actual width of all tabs (locked during layout)
        -- WidthAllTabsIdeal: Ideal width if all tabs were visible and not clipped
        WidthAllTabs = 0.0, WidthAllTabsIdeal = 0.0,
        ScrollingAnim = 0.0, ScrollingTarget = 0.0, ScrollingTargetDistToVisibility = 0.0, ScrollingSpeed = 0.0,
        ScrollingRectMinX = 0.0, ScrollingRectMaxX = 0.0, SeparatorMinX = 0.0, SeparatorMaxX = 0.0,
        ReorderRequestTabId = 0, ReorderRequestOffset = 0, BeginCount = 0,
        WantLayout = false, VisibleTabWasSubmitted = false, TabsAddedNew = false, ScrollButtonEnabled = false, -- TabsAddedNew: Set to true when a new tab item or button has been added to the tab bar during last frame
        TabsActiveCount = 0, -- Number of tabs submitted this frame.
        LastTabItemIdx = -1, -- 0-based -- Index of last BeginTabItem() tab for use by EndTabItem()
        ItemSpacingY = 0.0, FramePadding = ImVec2(), BackupCursorPos = ImVec2(), -- FramePadding: style.FramePadding locked at the time of BeginTabBar()
    }
end

--- @class ImGuiShrinkWidthItem
function ImGuiShrinkWidthItem() return { Index = 0, Width = 0.0, InitialWidth = 0.0 } end

--- @param shared_font_atlas? ImFontAtlas
--- @return ImGuiContext
--- @nodiscard
function ImGuiContext(shared_font_atlas) -- TODO: tidy up / complete this structure
    local this = {
        Style = ImGuiStyle(),
        ColorStack = ImVector(), -- Stack for PushStyleColor()/PopStyleColor() - inherited by Begin()
        StyleVarStack = ImVector(), -- Stack for PushStyleVar()/PopStyleVar() - inherited by Begin()

        Config = nil,
        Initialized = false,
        WithinFrameScope = false, -- Set by NewFrame(), cleared by EndFrame()
        WithinFrameScopeWithImplicitWindow = false, -- Set by NewFrame(), cleared by EndFrame() when the implicit debug window has been pushed

        Windows = ImVector(), -- Windows sorted in display order, back to front
        WindowsById = {}, -- Map window's ID to window ref

        WindowsBorderHoverPadding = 0, -- Padding around resizable windows for which hovering on counts as hovering the window == ImMax(style.TouchExtraPadding, style.WindowBorderHoverPadding). This isn't so multi-dpi friendly.

        WindowsActiveCount = 0, -- Number of unique windows submitted by frame

        WindowsTempSortBuffer = ImVector(), -- Temporary buffer used in EndFrame() to reorder windows so parents are kept before their child
        CurrentWindowStack = ImVector(),
        CurrentWindow = nil, -- Window being drawn into

        WindowsFocusOrder = ImVector(), -- Root windows, sorted in focus order, back to front.

        IO = ImGuiIO(),
        PlatformIO = ImGuiPlatformIO(),

        ConfigFlagsCurrFrame = ImGuiConfigFlags.None, -- = g.IO.ConfigFlags at the time of NewFrame()
        ConfigFlagsLastFrame = ImGuiConfigFlags.None,

        MouseLastValidPos = ImVec2(),

        KeysMayBeCharInput = ImBitArray(ImGuiKey.NamedKey_COUNT, -ImGuiKey.NamedKey_BEGIN), -- Lookup to tell if a key can emit char input, see IsKeyChordPotentiallyCharInput().
        KeysOwnerData = {}, -- size = ImGuiKey.NamedKey_COUNT
        KeysRoutingTable = ImGuiKeyRoutingTable(),

        InputEventsQueue = ImVector(), -- Input events which will be trickled/written into IO structure.

        InputEventsNextMouseSource = ImGuiMouseSource.Mouse,
        InputEventsNextEventId = 1,

        MovingWindow = nil, -- Track the window we clicked on (in order to preserve focus). The actual window that is moved is generally MovingWindow.RootWindowDockTree.

        WheelingWindow = nil, -- Track the window we started mouse-wheeling on. Until a timer elapse or mouse has moved, generally keep scrolling the same window even if during the course of scrolling the mouse ends up hovering a child window.
        WheelingWindowStartFrame = -1, WheelingWindowScrolledFrame = -1, -- This may be set one frame before WheelingWindow is ~= nil
        WheelingWindowReleaseTimer = 0.0,
        WheelingWindowRefMousePos = ImVec2(),
        WheelingWindowWheelRemainder = ImVec2(),
        WheelingAxisAvg = ImVec2(),

        ActiveIdClickOffset = ImVec2(), -- Clicked offset from upper-left corner, if applicable (currently only set by ButtonBehavior)

        HoveredWindow = nil, -- Window the mouse is hovering. Will typically catch mouse inputs.
        HoveredWindowUnderMovingWindow = nil, -- Hovered window ignoring MovingWindow. Only set if MovingWindow is set.
        HoveredIdIsDisabled = false, -- At least one widget passed the rect test, but has been discarded by disabled flag or popup inhibit. May be true even if HoveredId == 0.

        ActiveIdFromShortcut = false,

        AnyIdHasBeenEditedThisFrame = false,
        ActiveId = 0, -- Active widget
        ActiveIdWindow = nil,

        ActiveIdMouseButton = -1,

        ActiveIdIsJustActivated = false, -- Set at the time of activation for one frame

        ActiveIdWasSelected = false, ActiveIdWasSoleSelected = false, -- Active ID was selected at the time of activating
        LastActiveIdWasSelected = false, LastActiveIdWasSoleSelected = false,

        ActiveIdNoClearOnFocusLoss = false, -- Disable losing active id if the active id window gets unfocused.
        ActiveIdHasBeenPressedBefore = false, -- Track whether the active id led to a press (this is to allow changing between PressOnClick and PressOnRelease without pressing twice). Used by range_select branch.

        ActiveIdIsAlive = nil, -- Active widget has been seen this frame (we can't use a bool as the ActiveId may change within the frame)

        ActiveIdPreviousFrame = 0,

        ActiveIdTimer = 0.0,

        LastActiveId = 0, -- Store the last non-zero ActiveId, useful for animation.
        LastActiveIdTimer = 0.0, -- Store the last non-zero ActiveId timer since the beginning of activation, useful for animation.

        ActiveIdUsingNavDirMask = 0x00, -- Active widget will want to read those nav move requests (e.g. can activate a button and move away from it)
        ActiveIdUsingAllKeyboardKeys = false, -- Active widget will want to read all keyboard keys inputs. (this is a shortcut for not taking ownership of 100+ keys, frequently used by drag operations)

        DeactivatedItemData = {
            ID = 0,
            ElapseFrame = 0,
            HasBeenEditedBefore = false,
            IsAlive = false
        },

        HoveredId = 0, -- Hovered widget, filled during the frame
        HoveredIdTimer = 0.0, -- Measure contiguous hovering time
        HoveredIdNotActiveTimer = 0.0, -- Measure contiguous hovering time where the item has not been active
        HoveredIdAllowOverlap = false,

        HoverItemDelayId = 0, HoverItemDelayIdPreviousFrame = 0, HoverItemUnlockedStationaryId = 0, HoverWindowUnlockedStationaryId = 0,
        HoverItemDelayTimer = 0.0, HoverItemDelayClearTimer = 0.0, -- Currently used by IsItemHovered()

        ActiveIdAllowOverlap = false, -- Active widget allows another widget to steal active id (generally for overlapping widgets, but not always)

        NavLayer = ImGuiNavLayer.Main, -- Focused layer (main scrolling layer, or menu/title bar layer)
        NavId = 0, -- Focused item for navigation
        NavOpenContextMenuItemId = 0, NavOpenContextMenuWindowId = 0,
        NavWindow = nil, -- Focused window for navigation. Could be called 'FocusedWindow'
        NavHighlightActivatedId = 0,
        NavHighlightActivatedTimer = 0.0,
        NavCursorVisible = false, -- Nav focus cursor/rectangle is visible? We hide it after a mouse click. We show it after a nav move.
        NavCursorHideFrames = 0,
        NavHighlightItemUnderNav = false, -- Disable mouse hovering highlight. Highlight navigation focused item instead of mouse hovered item.
        NavIdIsAlive = false, -- Nav widget has been seen this frame ~~ NavRectRel is valid
        NavInputSource = ImGuiInputSource.Keyboard, -- Keyboard or Gamepad mode? THIS CAN ONLY BE ImGuiInputSource.Keyboard or ImGuiInputSource.Gamepad
        NavWindowingTarget = nil, NavWindowingTargetAnim = nil, NavWindowingListWindow = nil, -- Target window when doing Ctrl+Tab (or Pad Menu + FocusPrev/Next), this window is temporarily displayed top-most!
        NavWindowingTimer = 0.0, NavWindowingHighlightAlpha = 0.0,
        NavWindowingToggleLayer = false, -- Set while Alt or GamepadMenu is held, may be cleared by other operations, and processed when releasing the key.
        NavWindowingToggleKey = ImGuiKey.None, -- Keyboard/gamepad key used when toggling to menu layer.
        NavWindowingInputSource = ImGuiInputSource.None,
        NavWindowingAccumDeltaPos = ImVec2(0.0, 0.0), NavWindowingAccumDeltaSize = ImVec2(0.0, 0.0),
        DimBgRatio = 0.0, -- 0.0..1.0 animation when fading in a dimming background (for modal window and Ctrl+Tab list)
        LastKeyboardKeyPressTime = -1.0, LastKeyModsChangeTime = -1.0, LastKeyModsChangeFromNoneTime = -1.0, -- Record the last time a keyboard key (ignore mouse/gamepad ones) was pressed.
        ConfigNavWindowingKeyNext = bit32.bor(ImGuiMod_Ctrl, ImGuiKey.Tab), -- = ImGuiMod_Ctrl | ImGuiKey.Tab (or ImGuiMod_Super | ImGuiKey.Tab on OS X). Set to 0 to disable. For reconfiguration (see #4828)
        ConfigNavWindowingKeyPrev = bit32.bor(ImGuiMod_Ctrl, ImGuiMod_Shift, ImGuiKey.Tab), -- = ImGuiMod_Ctrl | ImGuiMod_Shift | ImGuiKey.Tab (or ImGuiMod_Super | ImGuiMod_Shift | ImGuiKey.Tab on OS X)
        ConfigNavWindowingWithGamepad = true, -- = true. Enable Ctrl+Tab by holding ImGuiKey.GamepadFaceLeft (== ImGuiKey.NavGamepadMenu). When false, the button may still be used to toggle Menu layer.

        NavFocusRoute = ImVector(), -- Reversed copy focus scope stack for NavId (should contains NavFocusScopeId). This essentially follow the window.ParentWindowForFocusRoute chain.

        NavAnyRequest = false, -- ~~ NavMoveRequest || NavInitRequest this is to perform early out in ItemAdd()
        NavInitRequest = false, -- Init request for appearing window to select first item
        NavInitRequestFromMove = false,
        NavInitResult = ImGuiNavItemData(), -- Init request result (first item of the window, or one for which SetItemDefaultFocus() was called)
        NavMoveSubmitted = false, -- Move request submitted, will process result on next NewFrame()
        NavMoveScoringItems = false, -- Move request submitted, still scoring incoming items
        NavMoveForwardToNextFrame = false,
        NavMoveFlags = ImGuiNavMoveFlags.None,
        NavMoveScrollFlags = ImGuiScrollFlags.None,
        NavMoveKeyMods = ImGuiMod_None,
        NavMoveDir = ImGuiDir.None, NavMoveDirForDebug = ImGuiDir.None, NavMoveClipDir = ImGuiDir.None, -- Direction of the move request (left/right/up/down)
        NavMoveResultLocal = ImGuiNavItemData(), -- Best move request candidate within NavWindow
        NavMoveResultOther = ImGuiNavItemData(), -- Best move request candidate within NavWindow's flattened hierarchy (when using ImGuiWindowFlags.NavFlattened flag)
        NavMoveResultLocalVisible = ImGuiNavItemData(), -- Best move request candidate within NavWindow that are mostly visible (when using ImGuiNavMoveFlags.AlsoScoreVisibleSet flag)
        NavTabbingResultFirst = ImGuiNavItemData(), -- First tabbing request candidate within NavWindow and flattened hierarchy
        NavScoringRect = ImRect(), -- Rectangle used for scoring, in screen space. Based of window.NavRectRel[], modified for directional navigation scoring.
        NavScoringNoClipRect = ImRect(), -- Some nav operations (such as PageUp/PageDown) enforce a region which clipper will attempt to always keep submitted. Unset/invalid if inverted.
        ConfigNavEnableTabbing = true, -- = true. Enable tabbing (Tab, Shift+Tab). PLEASE LET ME KNOW IF YOU USE THIS.
        NavTabbingCounter = 0, -- >0 when counting items for tabbing
        NavTabbingDir = 0, -- Generally -1 or +1, 0 when tabbing without a nav id
        NavNextActivateId = 0, -- Set by ActivateItemByID(), queued until next frame.
        NavNextActivateFlags = ImGuiActivateFlags.None,
        NavActivateId = 0, NavActivateDownId = 0, NavActivatePressedId = 0, -- ~~ (g.ActiveId == 0) && (IsKeyPressed(ImGuiKey.Space) || IsKeyDown(ImGuiKey.Enter) || IsKeyPressed(ImGuiKey.NavGamepadActivate)) ? NavId : 0, also set when calling ActivateItemByID()
        NavActivateFlags = ImGuiActivateFlags.None,

        FrameCount = -1,

        FrameCountEnded = -1,
        FrameCountPlatformEnded = -1,
        FrameCountRendered = -1,

        Time = 0,

        NextItemData = ImGuiNextItemData(), -- Storage for SetNextItem** functions
        LastItemData = ImGuiLastItemData(), -- Storage for last submitted item (setup by ItemAdd)
        NextWindowData = ImGuiNextWindowData(), -- Storage for SetNextWindow** functions

        Viewports = ImVector(), -- Active viewports (always 1+, and generally 1 unless multi-viewports are enabled). Each viewports hold their copy of ImDrawData.

        FallbackMonitor = nil, -- Virtual monitor used as fallback if backend doesn't provide monitor information.

        GcCompactAll = false, -- Request full GC

        CurrentViewport = nil,
        MouseViewport = nil, MouseLastHoveredViewport = nil,
        PlatformLastFocusedViewportId = 1,
        ViewportCreatedCount = 0, PlatformWindowsCreatedCount = 0, -- Unique sequential creation counter (mostly for testing/debugging)
        ViewportFocusedStampCount = 0, -- Every time the front-most window changes, we stamp its viewport with an incrementing counter

        Font = nil, -- Currently bound font. (== FontStack.back().Font)
        FontSize = 0.0, -- Currently bound font size == line height (== FontSizeBase + externals scales applied in the UpdateCurrentFontSize() function).
        FontSizeBase = 0.0, -- Font size before scaling == style.FontSizeBase == value passed to PushFont() when specified.
        CurrentDpiScale = 0.0, -- Current window/viewport DpiScale == CurrentViewport.DpiScale

        FontRefSize = 0.0,

        FontRasterizerDensity = 1.0,

        FontAtlases = ImVector(), -- List of font atlases used by the context (generally only contains g.IO.Fonts aka the main font atlas)

        FontStack = ImVector(), -- Stack for PushFont()/PopFont() - inherited by Begin()

        OpenPopupStack = ImVector(), -- Which popups are open (persistent)
        BeginPopupStack = ImVector(), -- Which level of BeginPopup() we are in (reset every frame)

        TreeNodeStack = ImVector(ImGuiTreeNodeStackData),

        WithinEndChildID = 0, WithinEndPopupID = 0, -- Set within EndChild()

        BeginMenuDepth = 0, BeginComboDepth = 0,

        ColorEditCurrentID = 0, ColorEditSavedID = 0, -- Set temporarily while inside of the parent-most ColorEdit4/ColorPicker4 (because they call each others).
        ColorEditSavedHue = 0.0, ColorEditSavedSat = 0.0, -- Backup of last Hue associated to LastColor, so we can restore Hue in lossy RGB<>HSV round trips
        ColorEditSavedColor = 0, -- RGB value with alpha set to 0.
        ColorPickerRef = ImVec4(), -- Initial/reference color at the time of opening the color picker.

        MenusIdSubmittedThisFrame = ImVector(), -- A list of menu IDs that were rendered at least once

        DrawListSharedData = ImDrawListSharedData(),

        StackSizesInBeginForCurrentWindow = nil,

        MouseCursor = ImGuiMouseCursor.Arrow,
        MouseStationaryTimer = 0.0, -- Time the mouse has been stationary (with some loose heuristic)

        InputTextState = ImGuiInputTextState(),
        InputTextLineIndex = ImGuiTextIndex(), -- Temporary storage
        InputTextDeactivatedState = ImGuiInputTextDeactivatedState(),
        InputTextPasswordFontBackupBaked = ImFontBaked(),
        InputTextReactivateId = 0, -- ID of InputText to reactivate on next frame (for io.ConfigInputTextEnterKeepActive behavior)
        TempInputId = 0, -- Temporary text input when using Ctrl+Click on a slider, etc.

        ActiveIdValueOnActivation = 0, -- Backup of initial value at the time of activation. ONLY SET BY SPECIFIC WIDGETS: DragXXX and SliderXXX.
        DataTypeZeroValue = 0, -- 0 for all data types

        ComboPreviewData = ImGuiComboPreviewData(),

        CurrentTabBar = nil,
        TabBars = ImPool(ImGuiTabBar),   -- ImPool<ImGuiTabBar>
        -- Docking
        DockContext = ImGuiDockContext(),
        DockNodeWindowMenuHandler = nil,
        DebugHoveredDockNode = nil, -- Hovered dock node.
        CurrentTabBarStack = ImVector(), -- holds ImGuiTabBar references directly (no ImGuiPtrOrIndex needed in Lua)
        ShrinkWidthBuffer = ImVector(),  -- ImGuiShrinkWidthItem

        WindowResizeBorderExpectedRect = ImRect(), -- Expected border rect, switch to relative edit if moving
        WindowResizeRelativeMode = false,

        ScrollbarSeekMode = 0, -- 0: scroll to clicked location, -1/+1: prev/next page.
        ScrollbarClickDeltaToGrabCenter = 0.0, -- When scrolling to mouse location: distance between mouse and center of grab box, normalized in parent space.

        SliderGrabClickOffset = 0.0,
        SliderCurrentAccum = 0.0, -- Accumulated slider delta when using navigation controls.
        SliderCurrentAccumDirty = false, -- Has the accumulated slider delta changed since last time we tried to apply it?
        DragCurrentAccumDirty = false,
        DragCurrentAccum = 0.0, -- Accumulator for dragging modification. Always high-precision, not rounded by end-user precision settings
        DragSpeedDefaultRatio = 1.0 / 100.0, -- If speed == 0.0, uses (max-min) * DragSpeedDefaultRatio

        TooltipOverrideCount = 0,
        TooltipPreviousWindow = nil, -- Window of last tooltip submitted during the frame

        FocusScopeStack = ImVector(), -- Stack for PushFocusScope()/PopFocusScope() - inherited by BeginChild(), pushed into by Begin()
        CurrentFocusScopeId = 0, -- Value for currently appending items == g.FocusScopeStack.back(). Not to be mistaken with g.NavFocusScopeId.
        CurrentItemFlags = ImGuiItemFlags.None, -- Value for currently appending items == g.ItemFlagsStack.back()

        DisabledAlphaBackup = 0.0, -- Backup for style.Alpha for BeginDisabled()
        DisabledStackSize = 0,

        ItemFlagsStack = ImVector(), -- Stack for PushItemFlag()/PopItemFlag() - inherited by Begin()
        GroupStack = ImVector(), -- Stack for BeginGroup()/EndGroup() - not inherited by Begin()

        PlatformImeData = ImGuiPlatformImeData(), -- Data updated by current frame. Will be applied at end of the frame. For some backends, this is required to have WantVisible=true in order to receive text message.
        PlatformImeDataPrev = ImGuiPlatformImeData(), -- Previous frame data. When changed we call the platform_io.Platform_SetImeDataFn() handler.

        -- Extensions
        UserTextures = ImVector(), -- List of textures created/managed by user or third-party extension. Automatically appended into platform_io.Textures[].

        -- Settings
        SettingsLoaded = false,
        SettingsDirtyTimer = 0.0, -- Save .ini Settings to memory when time reaches zero
        SettingsIniData = "",          -- In memory .ini settings (string)
        SettingsHandlers = ImVector(), -- List of .ini settings handlers
        SettingsWindows = ImVector(), -- ImGuiWindow .ini settings entries
        SettingsTables = ImVector(), -- ImGuiTable .ini settings entries

        -- Hooks
        Hooks = ImVector(), -- Hooks for extensions (e.g. test engine)
        HookIdNext = 0, -- Next available HookId

        -- Drag and Drop
        DragDropActive = false,
        DragDropWithinSource = false, -- Set when within a BeginDragDropXXX/EndDragDropXXX block for a drag source.
        DragDropWithinTarget = false, -- Set when within a BeginDragDropXXX/EndDragDropXXX block for a drag target.
        DragDropSourceFlags = 0,
        DragDropSourceFrameCount = -1,
        DragDropMouseButton = -1,
        DragDropPayload = ImGuiPayload(),
        DragDropTargetRect = ImRect(), -- Store rectangle of current target candidate (we favor small targets when overlapping)
        DragDropTargetClipRect = ImRect(), -- Store ClipRect at the time of item's drawing
        DragDropTargetId = 0,
        DragDropTargetFullViewport = 0,
        DragDropAcceptFlagsCurr = 0, DragDropAcceptFlagsPrev = 0,
        DragDropAcceptIdCurrRectSurface = 0.0, -- Target item surface (we resolve overlapping targets by prioritizing the smaller surface)
        DragDropAcceptFrameCount = -1, -- Last time a target expressed a desire to accept the source
        DragDropHoldJustPressedId = 0, -- Set when holding a payload just made ButtonBehavior() return a press.

        DragDropAcceptIdPrev = 0, DragDropAcceptIdCurr = 0, -- Target item id from previous frame (we need to store this to allow for overlapping drag and drop targets)

        -- Clipper
        ClipperTempDataStacked = 0,
        ClipperTempData = ImVector(),

        -- Logging
        LogEnabled = false, -- Currently capturing
        LogLineFirstItem = false,
        LogFlags = 0, -- Capture flags/type
        LogWindow = nil,
        LogFile = nil, -- If ~= nil log to stdout/ file
        LogBuffer = ImGuiTextBuffer(), -- Accumulation buffer when log to clipboard.
        LogNextPrefix = nil, LogNextSuffix = nil, -- See comment in LogSetNextTextDecoration(): doesn't copy underlying data, use carefully!
        LogLinePosY = FLT_MAX,
        LogDepthRef = 0,
        LogDepthToExpand = 2, LogDepthToExpandDefault = 2,

        -- Error handling
        ErrorCallback = nil, ErrorCallbackUserData = nil, -- = nil. May be exposed in public API eventually.
        ErrorTooltipLockedPos = ImVec2(),
        ErrorFirst = true,
        ErrorCountCurrentFrame = 0, -- [Internal] Number of errors submitted this frame.
        StackSizesInNewFrame = nil, -- [Internal]
        ContextName = "", -- Storage for a context name (to facilitate debugging multi-context setups)
        DebugBreakInWindow = 0, -- Set to break in Begin() call.

        LocalizationTable = {},

        DebugLogFlags = bitOr(ImGuiDebugLogFlags.EventError, ImGuiDebugLogFlags.OutputToTTY),
        DebugFlashStyleColorIdx = nil,

        DebugMetricsConfig = ImGuiMetricsConfig(),
        DebugHookIdInfoId = 0, -- Will call core hooks: DebugHookIdInfo() from GetID functions, used by ID Stack Tool
        DebugAllocInfo = ImGuiDebugAllocInfo(),

        --- Misc
        FramerateSecPerFrame = {}, -- size = 60
        FramerateSecPerFrameIdx = 0,
        FramerateSecPerFrameCount = 0,
        FramerateSecPerFrameAccum = 0,

        WantCaptureMouseNextFrame = -1, -- Explicit capture override via SetNextFrameWantCaptureMouse()/SetNextFrameWantCaptureKeyboard(). Default to -1.
        WantCaptureKeyboardNextFrame = -1, -- "
        WantTextInputNextFrame = -1, -- Copied in EndFrame() from g.PlatformImeData.WantTextInput. Needs to be set for some backends (SDL3) to emit character inputs.
        TempBuffer = ImVector(), -- Temporary text buffer

        -- Tables (imgui_tables.lua)
        CurrentTable = nil,
        DebugBreakInTable = 0, -- Set to break in BeginTable() call.
        TablesTempDataStacked = 0, -- Temporary table data size (because we leave previous instances undestructed, we generally don't use TablesTempData.Size)
        TablesTempData = ImVector(), -- Temporary table data (buffers reused/shared across instances, support nesting)
        Tables = ImPool(),                 -- ImPool<ImGuiTable>, 0-based indices (imgui_tables.lua)
        TablesLastTimeActive = ImVector(), -- [table_idx + 1] = float
        DrawChannelsTempMergeBuffer = ImVector(),
        SettingsTables = ImVector(),       -- ImChunkStream<ImGuiTableSettings>: plain vector, SettingsOffset = 1-based index
    }

    for i = 0, 59 do this.FramerateSecPerFrame[i] = 0 end

    this.IO.Fonts = (shared_font_atlas ~= nil) and shared_font_atlas or ImFontAtlas()
    if shared_font_atlas == nil then
        this.IO.Fonts.OwnerContext = this
    end

    for i = 0, ImGuiKey.NamedKey_COUNT - 1 do
        this.KeysOwnerData[i] = ImGuiKeyOwnerData()
    end

    this.IO.Ctx = this
    this.InputTextState.Ctx = this

    ImVec2_Copy(this.PlatformImeDataPrev.InputPos, ImVec2(-1.0, -1.0))

    return this
end

-------------------------------------------------------------------------------
-- [SECTION] Settings support
-------------------------------------------------------------------------------

-- Windows data saved in imgui.ini file
--- @class ImGuiWindowSettings
--- @field ID           int     # Window ID
--- @field Pos          ImVec2  # Window position
--- @field Size         ImVec2  # Window size
--- @field Collapsed    bool    # Whether window is collapsed
--- @field IsChild      bool    # Whether window is a child window
--- @field WantApply    bool    # Set when loaded from .ini data
--- @field WantDelete   bool    # Set to invalidate/delete the settings entry
--- @field Name         string  # Window name
local IMGUI_WINDOW_SETTINGS = {}
IMGUI_WINDOW_SETTINGS.__index = IMGUI_WINDOW_SETTINGS

function IMGUI_WINDOW_SETTINGS:GetName()
    return self.Name
end

function ImGuiWindowSettings()
    return setmetatable({
        ID           = 0,
        Pos          = ImVec2(0, 0), -- NB: Settings position are stored RELATIVE to the viewport! Whereas runtime ones are absolute positions.
        Size         = ImVec2(0, 0),
        Collapsed    = false,
        IsChild      = false,
        WantApply    = false, -- Set when loaded from .ini data (to enable merging/loading .ini data into an already running context)
        WantDelete   = false, -- Set to invalidate/delete the settings entry
        Name         = "",
        ViewportId   = 0,
        ViewportPos  = ImVec2(0, 0),
        DockId       = 0, -- ID of last known DockNode (even if the DockNode is invisible because it has only 1 active window), or 0 if none.
        DockOrder    = -1, -- Order of the last time the window was visible within its DockNode. This is used to reorder windows that are reappearing on the same frame. Same value between windows that were active and windows that were none are possible.
        ClassId      = 0, -- ID of window class if specified
        LastUsedDate = 0,
    }, IMGUI_WINDOW_SETTINGS)
end

-- Simple column measurement, currently used for MenuItem() only.. This is very short-sighted/throw-away code and NOT a generic helper.
--- @class ImGuiMenuColumns
--- @field TotalWidth     ImU32
--- @field NextTotalWidth ImU32
--- @field Spacing        ImU16
--- @field OffsetIcon     ImU16   # Always zero for now
--- @field OffsetLabel    ImU16   # Offsets are locked in Update()
--- @field OffsetShortcut ImU16
--- @field OffsetMark     ImU16
--- @field Widths         ImU16[] # Width of: Icon, Label, Shortcut, Mark (accumulators for current frame)
MT.ImGuiMenuColumns = {}
MT.ImGuiMenuColumns.__index = MT.ImGuiMenuColumns

--- @return ImGuiMenuColumns
local function ImGuiMenuColumns()
    return setmetatable({
        TotalWidth     = 0,
        NextTotalWidth = 0,
        Spacing        = 0,
        OffsetIcon     = 0, -- Always zero for now
        OffsetLabel    = 0, -- Offsets are locked in Update()
        OffsetShortcut = 0,
        OffsetMark     = 0,
        Widths         = {0, 0, 0, 0} -- Width of:   Icon, Label, Shortcut, Mark  (accumulators for current frame)
    }, MT.ImGuiMenuColumns)
end

-------------------------------------------------------------------------------
-- [SECTION] ImGuiWindowTempData, ImGuiWindow
-------------------------------------------------------------------------------

-- Transient per-window data, reset at the beginning of the frame. This used to be called ImGuiDrawContext, hence the DC variable name in ImGuiWindow.
-- (That's theory, in practice the delimitation between ImGuiWindow and ImGuiWindowTempData is quite tenuous and could be reconsidered..)
--- @class ImGuiWindowTempData
--- @field CursorPos                     ImVec2
--- @field CursorPosPrevLine             ImVec2
--- @field CursorStartPos                ImVec2
--- @field CursorMaxPos                  ImVec2
--- @field IdealMaxPos                   ImVec2
--- @field CurrLineSize                  ImVec2
--- @field PrevLineSize                  ImVec2
--- @field CurrLineTextBaseOffset        float
--- @field PrevLineTextBaseOffset        float
--- @field IsSameLine                    bool
--- @field IsSetPos                      bool
--- @field Indent                        ImVec1
--- @field ColumnsOffset                 ImVec1
--- @field GroupOffset                   ImVec1
--- @field CursorStartPosLossyness       ImVec2
--- @field TextWrapPos                   float
--- @field TextWrapPosStack              ImVector
--- @field MenuBarAppending              bool
--- @field MenuBarOffset                 ImVec2
--- @field MenuColumns                   ImGuiMenuColumns
--- @field TreeDepth                     int
--- @field TreeHasStackDataDepthMask     ImU32
--- @field TreeRecordsClippedNodesY2Mask ImU32
--- @field ChildWindows                  ImVector<ImGuiWindow>
--- @field LayoutType                    ImGuiLayoutType

--- @return ImGuiWindowTempData
--- @nodiscard
local function ImGuiWindowTempData()
    return {
        DockTabItemStatusFlags = 0,
        DockTabItemRect = ImRect(),
        CursorPos         = ImVec2(), -- Current emitting position, in absolute coordinates.
        CursorPosPrevLine = ImVec2(),
        CursorStartPos    = ImVec2(), -- Initial position after Begin(), generally ~ window position + WindowPadding.
        CursorMaxPos      = ImVec2(), -- Used to implicitly calculate ContentSize at the beginning of next frame, for scrolling range and auto-resize. Always growing during the frame.
        IdealMaxPos       = ImVec2(), -- Used to implicitly calculate ContentSizeIdeal at the beginning of next frame, for auto-resize only. Always growing during the frame.
        CurrLineSize      = ImVec2(),
        PrevLineSize      = ImVec2(),

        CurrLineTextBaseOffset = 0, -- Baseline offset (0.0 by default on a new line, generally == style.FramePadding.y when a framed item has been added).
        PrevLineTextBaseOffset = 0,

        IsSameLine = false,
        IsSetPos = false,
        NavLayersActiveMask = 0, NavLayersActiveMaskNext = 0, -- Which layers have been written to (result from previous frame)

        Indent                  = ImVec1(), -- Indentation / start position from left of window (increased by TreePush/TreePop, etc.)
        ColumnsOffset           = ImVec1(), -- Offset to the current column (if ColumnsCurrent > 0). FIXME: This and the above should be a stack to allow use cases like Tree.Column.Tree. Need revamp columns API.
        GroupOffset             = ImVec1(),
        CursorStartPosLossyness = ImVec2(), -- Record the loss of precision of CursorStartPos due to really large scrolling amount. This is used by clipper to compensate and fix the most common use case of large scroll area.

        ItemWidth = 0, -- Current item width (>0.0: width in pixels, <0.0: align xx pixels to the right of window).
        ItemWidthDefault = 0,
        TextWrapPos = 0, -- Current text wrap pos.
        ItemWidthStack = ImVector(), -- Store item widths to restore (attention: .back() is not == ItemWidth)
        TextWrapPosStack = ImVector(), -- Store text wrap pos to restore (attention: .back() is not == TextWrapPos)

        MenuBarAppending = false, -- FIXME: Remove this
        MenuBarOffset = ImVec2(), -- MenuBarOffset.x is sort of equivalent of a per-layer CursorPos.x, saved/restored as we switch to the menu bar. The only situation when MenuBarOffset.y is > 0 if when (SafeAreaPadding.y > FramePadding.y), often used on TVs.
        MenuColumns = ImGuiMenuColumns(), -- Simplified columns storage for menu items measurement
        TreeDepth = 0, -- Current tree depth.
        TreeHasStackDataDepthMask = nil, -- Store whether given depth has ImGuiTreeNodeStackData data. Could be turned into a ImU64 if necessary. Sync any changes with TREE_NODE_MAX_DEPTH/TREE_NODE_GET_DEPTH_MASK!
        TreeRecordsClippedNodesY2Mask = nil, -- Store whether we should keep recording Y2. Cleared when passing clip max. Equivalent TreeHasStackDataDepthMask value should always be set.

        ChildWindows = ImVector(),
        CurrentTableIdx = -1,  -- 0-based index into g.Tables, -1 if none
        CurrentColumns = nil,  -- ImGuiOldColumns (legacy Columns API)
        StateStorage = nil, -- Current persistent per-window storage (store e.g. tree node open/close state)

        LayoutType = nil
    }
end

-- Storage for one window
--- @class ImGuiWindow
--- @field Ctx                                ImGuiContext
--- @field Name                               string
--- @field ID                                 ImGuiID
--- @field Flags                              ImGuiWindowFlags
--- @field FlagsPreviousFrame                 ImGuiWindowFlags
--- @field ChildFlags                         ImGuiChildFlags
--- @field WindowClass                        ImGuiWindowClass
--- @field Viewport                           ImGuiViewportP
--- @field ViewportId                         ImGuiID
--- @field ViewportPos                        ImVec2
--- @field ViewportAllowPlatformMonitorExtend int
--- @field Pos                                ImVec2
--- @field Size                               ImVec2
--- @field SizeFull                           ImVec2
--- @field ContentSize                        ImVec2
--- @field ContentSizeIdeal                   ImVec2
--- @field ContentSizeExplicit                ImVec2
--- @field Scroll                             ImVec2
--- @field IsExplicitChild                    bool
--- @field FocusOrder                         short               # 1-based, order within WindowsFocusOrder, altered when windows are focused. Can be -1 if invalid
--- @field IDStack                            ImVector<ImGuiID>
--- @field DC                                 ImGuiWindowTempData
--- @field OuterRectClipped                   ImRect
--- @field InnerRect                          ImRect
--- @field InnerClipRect                      ImRect
--- @field WorkRect                           ImRect
--- @field ParentWorkRect                     ImRect
--- @field ClipRect                           ImRect
--- @field ContentRegionRect                  ImRect
--- @field DrawList                           ImDrawList          # Points to DrawListInst
--- @field DrawListInst                       ImDrawList
--- @field ParentWindow?                      ImGuiWindow
--- @field RootWindow                         ImGuiWindow
--- @field RootWindowPopupTree                ImGuiWindow
--- @field RootWindowDockTree                 ImGuiWindow
--- @field StateStorage                       {[ImGuiID]: bool}
--- @field MemoryDrawListIdxCapacity          int
--- @field MemoryDrawListVtxCapacity          int
--- @field MemoryCompacted                    bool
MT.ImGuiWindow = {}
MT.ImGuiWindow.__index = MT.ImGuiWindow

-- We don't use g.FontSize because the window may be != g.CurrentWindow.
--- @return ImRect
--- @nodiscard
function MT.ImGuiWindow:Rect()
    return ImRect(self.Pos.x, self.Pos.y, self.Pos.x + self.Size.x, self.Pos.y + self.Size.y)
end

--- @return ImRect
--- @nodiscard
function MT.ImGuiWindow:TitleBarRect()
    return ImRect(self.Pos, ImVec2(self.Pos.x + self.SizeFull.x, self.Pos.y + self.TitleBarHeight))
end

--- @return ImRect
--- @nodiscard
function MT.ImGuiWindow:MenuBarRect()
    local y1 = self.Pos.y + self.TitleBarHeight
    return ImRect(self.Pos.x, y1, self.Pos.x + self.SizeFull.x, y1 + self.MenuBarHeight)
end

--- @return ImGuiWindow
--- @nodiscard
function ImGuiWindow(ctx, name)
    local this = {
        ID = 0, -- == ImHashStr(Name)

        MoveId = 0, -- == window.GetID("#MOVE")

        Ctx = ctx, -- Parent UI context (needs to be set explicitly by parent).
        Name = name, -- Window name

        Flags = 0,

        ChildFlags = 0, -- Set when window is a child window. See enum ImGuiChildFlags
        WindowClass = ImGuiWindowClass(), -- Advanced users only. Set with SetNextWindowClass()

        Pos = ImVec2(), -- Position (always rounded-up to nearest pixel)
        Size = ImVec2(), -- Current size (==SizeFull or collapsed title bar size)
        SizeFull = ImVec2(), -- Size when non collapsed

        Active = false, -- Set to true on Begin(), unless Collapsed
        WasActive = false,

        Collapsed = false, -- Set when collapsing window to become only title-bar

        SkipItems = false, -- Set when items can safely be all clipped (e.g. window not visible or collapsed)

        SkipRefresh = false, -- [EXPERIMENTAL] Reuse previous frame drawn contents, Begin() returns false.
        CacheSnap = nil, -- [Port] SetNextWindowCached(): state at the last refresh
        CacheSkipItemsBackup = nil,

        Appearing = false, -- Set during the frame where the window is appearing (or re-appearing)

        Hidden = false, -- Do not display (== HiddenFrames*** > 0)
        IsFallbackWindow = false, -- Set on the "Debug##Default" window.

        IsExplicitChild = nil, -- Set when passed _ChildWindow, left to false by BeginDocked()

        ResizeBorderHovered = -1, -- Current border being hovered for resize (-1: none, otherwise 0-3)
        ResizeBorderHeld = -1, -- Current border being held for resize (-1: none, otherwise 0-3)

        BeginCount = 0, -- Number of Begin() during the current frame (generally 0 or 1, 1+ if appending via multiple Begin/End pairs)
        BeginCountPreviousFrame = 0, -- Number of Begin() during the previous frame
        BeginOrderWithinParent = 0, -- Begin() order within immediate parent window, if we are a child window. Otherwise 0.
        BeginOrderWithinContext = 0, -- Begin() order within entire imgui context. This is mostly used for debugging submission order related issues.

        FocusOrder = nil, -- Order within WindowsFocusOrder[], altered when windows are focused.

        HiddenFramesCanSkipItems = 0, -- Hide the window for N frames
        HiddenFramesCannotSkipItems = 0, -- Hide the window for N frames while allowing items to be submitted so we can measure their size
        HiddenFramesForRenderOnly = 0, -- Hide the window until frame N at Render() time only

        DisableInputsFrames = 0, -- Disable window interactions for N frames

        WindowRounding = 0, -- Window rounding at the time of Begin(). May be clamped lower to avoid rendering artifacts with title bar, menu bar etc.
        WindowBorderSize = 1, -- Window border size at the time of Begin().

        TitleBarHeight = 0, MenuBarHeight = 0,

        DecoOuterSizeX1 = 0, DecoOuterSizeY1 = 0,
        DecoOuterSizeX2 = 0, DecoOuterSizeY2 = 0,
        DecoInnerSizeX1 = 0, DecoInnerSizeY1 = 0,

        ContentSize = ImVec2(), -- Size of contents/scrollable client area (calculated from the extents reach of the cursor) from previous frame. Does not include window decoration or window padding.
        ContentSizeIdeal = ImVec2(),
        ContentSizeExplicit = ImVec2(), -- Size of contents/scrollable client area explicitly request by the user via SetNextWindowContentSize().

        AutoFitFramesX = -1, AutoFitFramesY = -1,
        AutoFitOnlyGrows = false,

        HasCloseButton = true, -- Set when the window has a close button (p_open ~= nil)

        BgClickFlags = 0, -- Configure behavior of click+dragging on window bg/void or over items. Default sets by io.ConfigWindowsMoveFromTitleBarOnly. If you use this please report in #3379.

        SetWindowPosAllowFlags = 0, SetWindowSizeAllowFlags = 0, SetWindowCollapsedAllowFlags = 0, -- store acceptable condition flags for SetNextWindowPos() use.
        SetWindowPosVal = ImVec2(FLT_MAX, FLT_MAX), -- store window position when using a non-zero Pivot (position set needs to be processed when we know the window size)
        SetWindowPosPivot = ImVec2(FLT_MAX, FLT_MAX), -- store window pivot for positioning. ImVec2(0, 0) when positioning from top-left corner; ImVec2(0.5, 0.5) for centering; ImVec2(1, 1) for bottom right.

        SettingsOffset = -1, -- Offset into SettingsWindows[] (offsets are always valid as we only grow the array from the back)

        ScrollbarSizes = ImVec2(), -- Size taken by each scrollbars on their smaller axis. Pay attention! ScrollbarSizes.x == width of the vertical scrollbar, ScrollbarSizes.y = height of the horizontal scrollbar.
        Scroll = ImVec2(),

        ScrollbarX = false,
        ScrollbarY = false, -- Are scrollbars visible?
        ScrollMax = ImVec2(),
        ScrollTarget = ImVec2(FLT_MAX, FLT_MAX), -- target scroll position. stored as cursor position with scrolling canceled out, so the highest point is always 0.0. (FLT_MAX for no change)
        ScrollTargetCenterRatio = ImVec2(0.5, 0.5), -- 0.0 = scroll so that target position is at top, 0.5 = scroll so that target position is centered
        ScrollTargetEdgeSnapDist = ImVec2(), -- 0.0 = no snapping, >0.0 snapping threshold

        ScrollbarXStabilizeToggledHistory = 0, -- Used to stabilize scrollbar visibility in case of feedback loops

        DrawList = nil, -- == DrawListInst
        DrawListInst = ImDrawList(ctx.DrawListSharedData),

        RootWindow = nil, -- Point to ourself or first ancestor that is not a child window. Doesn't cross through popups/dock nodes.
        RootWindowPopupTree = nil, -- Point to ourself or first ancestor that is not a child window. Cross through popups parent<>child.
        RootWindowDockTree = nil, -- Point to ourself or first ancestor that is not a child window. Cross through dock nodes.

        ParentWindow = nil, -- If we are a child _or_ popup _or_ docked window, this is pointing to our parent. Otherwise nil.
        ParentWindowInBeginStack = nil,

        IDStack = ImVector(), -- ID stack. ID are hashes seeded with the value at the top of the stack. (In theory this should be in the TempData structure)

        ViewportAllowPlatformMonitorExtend = -1, -- Reset to -1 every frame (index is guaranteed to be valid between NewFrame..EndFrame), only used in the Appearing frame of a tooltip/popup to enforce clamping to a given monitor
        Viewport = nil, -- Always set in Begin(). Inactive windows may have a nil value here if their viewport was discarded.
        ViewportId = 0, -- We backup the viewport id (since the viewport may disappear or never be created if the window is inactive)
        ViewportPos = ImVec2(FLT_MAX, FLT_MAX), -- We backup the viewport position (since the viewport may disappear or never be created if the window is inactive)
        ViewportOwned = nil,

        DC = ImGuiWindowTempData(), -- Temporary per-window data, reset at the beginning of the frame. This used to be called ImGuiDrawContext, hence the "DC" variable name.

        OuterRectClipped  = ImRect(), -- == Window.Rect() just after setup in Begin(). == window.Rect() for root window.
        InnerRect         = ImRect(), -- Inner rectangle (omit title bar, menu bar, scroll bar)
        InnerClipRect     = ImRect(), -- == InnerRect shrunk by WindowPadding*0.5 on each side, clipped within viewport or parent clip rect.
        WorkRect          = ImRect(), -- Initially covers the whole scrolling region. Reduced by containers e.g columns/tables when active. Shrunk by WindowPadding*1.0 on each side. This is meant to replace ContentRegionRect over time (from 1.71+ onward).
        ParentWorkRect    = ImRect(), -- Backup of WorkRect before entering a container such as columns/tables. Used by e.g. SpanAllColumns functions to easily access. Stacked containers are responsible for maintaining this. -- FIXME-WORKRECT: Could be a stack?
        ContentRegionRect = ImRect(), -- FIXME: This is currently confusing/misleading. It is essentially WorkRect but not handling of scrolling. We currently rely on it as right/bottom aligned sizing operation need some size to rely on.

        ClipRect = ImRect(), -- Current clipping/scissoring rectangle, evolve as we are using PushClipRect(), etc. == DrawList.clip_rect_stack.back().

        LastFrameActive = -1, -- Last frame number the window was Active.
        LastFrameJustFocused = -1, -- Last frame number the window was made Focused.
        LastTimeActive = -1.0, -- Last timestamp the window was Active (using float as we don't need high precision there)

        StateStorage = {},
        ColumnsStorage = ImVector(), -- ImVector<ImGuiOldColumns>

        WriteAccessed = false, -- Set to true when any widget access the current window

        FontWindowScale = 1.0, -- User scale multiplier per-window, via SetWindowFontScale()
        FontWindowScaleParents = 1.0,

        HitTestHoleSize = ImVec2(), -- Define an optional rectangular hole where mouse will pass-through the window.

        NavLastChildNavWindow = nil, -- When going to the menu bar, we remember the child window we came from. (This could probably be made implicit if we kept g.Windows sorted by last focused including child window.)
        NavLastIds = {[0] = 0, [1] = 0}, -- FIXME: 1-based instead
        NavRectRel = {[0] = ImRect(), [1] = ImRect()}, -- Reference rectangle, in window relative space
        NavPreferredScoringPosRel = {[0] = ImVec2(), [1] = ImVec2()}, -- Preferred X/Y position updated when moving on a given axis, reset to FLT_MAX.
        NavRootFocusScopeId = 0 -- Focus Scope ID at the time of Begin()
    }

    this.DrawList = this.DrawListInst
    this.DrawList._OwnerName = name

    setmetatable(this, MT.ImGuiWindow)

    this.ID = ImHashStr(name)
    this.IDStack:push_back(this.ID)
    this.MoveId = this:GetID("#MOVE")
    this.TabId = this:GetID("#TAB") -- == window.GetID("#TAB")
    -- Docking
    this.ChildId = this.ChildId or 0 -- ID of corresponding item in parent window (for navigation to return from child window to parent window)
    this.SetWindowDockAllowFlags = 0 -- store acceptable condition flags for SetNextWindowDock() use.
    this.ParentWindowForFocusRoute = nil -- Set to manual link a window to its logical parent so that Shortcut() chain are honored (e.g. Tool linked to Document)
    this.DockIsActive = false -- When docking artifacts are actually visible. When this is set, DockNode is guaranteed to be != nil. ~~ (DockNode != nil) && (DockNode.Windows.Size > 1).
    this.DockNodeIsVisible = false
    this.DockTabIsVisible = false -- Is our window visible this frame? ~~ is the corresponding tab selected?
    this.DockTabWantClose = false
    this.DockOrder = -1 -- Order of the last time the window was visible within its DockNode. This is used to reorder windows that are reappearing on the same frame. Same value between windows that were active and windows that were none are possible.
    this.DockStyle = { Colors = {} }
    for i = 0, 8 do this.DockStyle.Colors[i] = 0 end
    this.DockNode = nil -- Which node are we docked into. Important: Prefer testing DockIsActive in many cases as this will still be set when the dock node is hidden.
    this.DockNodeAsHost = nil -- Which node are we owning (for parent windows)
    this.DockId = 0 -- Backup of last valid DockNode.ID, so single window remember their dock node id even when they are not bound any more

    return this
end

--- @class ImDrawDataBuilder
--- @field Layers     [ImVector<ImDrawList>?, ImVector<ImDrawList>?] # Pointers to global layers for: regular, tooltip. LayersP[0] is owned by DrawData.
--- @field LayerData1 ImVector<ImDrawList>

--- @return ImDrawDataBuilder
--- @nodiscard
local function ImDrawDataBuilder()
    return
    {
        Layers     = {nil, nil}, -- Pointers to global layers for: regular, tooltip. LayersP[0] is owned by DrawData.
        LayerData1 = ImVector()
    }
end

-------------------------------------------------------------------------------
-- [SECTION] Viewport support
-------------------------------------------------------------------------------

-- ImGuiViewport Private/Internals fields (cardinal sin: we are using inheritance!)
-- Every instance of ImGuiViewport is in fact a ImGuiViewportP.
--- @class ImGuiViewportP : ImGuiViewport
--- @field Window?                     ImGuiWindow
--- @field Idx                         int                      # Initial value = -1, then becomes 1-based index
--- @field LastFrameActive             int
--- @field LastFocusedStampCount       int
--- @field LastNameHash                ImGuiID
--- @field LastPos                     ImVec2
--- @field LastSize                    ImVec2
--- @field Alpha                       float
--- @field LastAlpha                   float
--- @field LastFocusedHadNavWindow     bool
--- @field PlatformMonitor             short
--- @field BgFgDrawListsLastTimeActive [int, int]               # 1-based
--- @field BgFgDrawLists               [ImDrawList, ImDrawList] # 1-based
--- @field DrawDataP                   ImDrawData
--- @field DrawDataBuilder             ImDrawDataBuilder
--- @field LastPlatformPos             ImVec2
--- @field LastPlatformSize            ImVec2
--- @field LastRendererSize            ImVec2
--- @field WorkInsetMin                ImVec2
--- @field WorkInsetMax                ImVec2
--- @field BuildWorkInsetMin           ImVec2
--- @field BuildWorkInsetMax           ImVec2
local IMGUI_VIEWPORT_P = {}
IMGUI_VIEWPORT_P.__index = IMGUI_VIEWPORT_P

setmetatable(IMGUI_VIEWPORT_P, {__index = MT.ImGuiViewport})

function IMGUI_VIEWPORT_P:ClearRequestFlags()
    self.PlatformRequestClose  = false
    self.PlatformRequestMove   = false
    self.PlatformRequestResize = false
end

-- Calculate work rect pos/size given a set of offset (we have 1 pair of offset for rect locked from last frame data, and 1 pair for currently building rect)
function IMGUI_VIEWPORT_P:CalcWorkRectPos(inset_min)
    return ImVec2(self.Pos.x + inset_min.x, self.Pos.y + inset_min.y)
end

function IMGUI_VIEWPORT_P:CalcWorkRectSize(inset_min, inset_max)
    return ImVec2(ImMax(0.0, self.Size.x - inset_min.x - inset_max.x), ImMax(0.0, self.Size.y - inset_min.y - inset_max.y))
end

-- Update public fields
function IMGUI_VIEWPORT_P:UpdateWorkRect()
    self.WorkPos = self:CalcWorkRectPos(self.WorkInsetMin)
    self.WorkSize = self:CalcWorkRectSize(self.WorkInsetMin, self.WorkInsetMax)
end

-- Helpers to retrieve ImRect (we don't need to store BuildWorkRect as every access tend to change it, hence the code asymmetry)
--- @nodiscard
function IMGUI_VIEWPORT_P:GetMainRect()
    return ImRect(self.Pos.x, self.Pos.y,
        self.Pos.x + self.Size.x,
        self.Pos.y + self.Size.y)
end

--- @nodiscard
function IMGUI_VIEWPORT_P:GetWorkRect()
    return ImRect(self.WorkPos.x, self.WorkPos.y,
        self.WorkPos.x + self.WorkSize.x,
        self.WorkPos.y + self.WorkSize.y)
end

--- @nodiscard
function IMGUI_VIEWPORT_P:GetBuildWorkRect()
    local pos = self:CalcWorkRectPos(self.BuildWorkInsetMin)
    local size = self:CalcWorkRectSize(self.BuildWorkInsetMin, self.BuildWorkInsetMax)
    return ImRect(pos.x, pos.y, pos.x + size.x, pos.y + size.y)
end

--- @return ImGuiViewportP
--- @nodiscard
function ImGuiViewportP()
    local this = setmetatable(ImGuiViewport(), IMGUI_VIEWPORT_P) --- @cast this ImGuiViewportP

    this.Window = nil -- Set when the viewport is owned by a window (and ImGuiViewportFlags.CanHostOtherWindows is NOT set)
    this.Idx = -1

    this.LastFrameActive       = -1 -- Last frame number this viewport was activated by a window
    this.LastFocusedStampCount = -1 -- Last stamp number from when a window hosted by this viewport was focused (by comparing this value between two viewport we have an implicit viewport z-order we use as fallback)
    this.LastNameHash          = 0
    this.LastPos               = ImVec2() -- ImGuiViewport() { memset(this, 0, sizeof(*this)); }
    this.LastSize              = ImVec2()

    this.Alpha     = 1.0 -- Window opacity (when dragging dockable windows/viewports we make them transparent)
    this.LastAlpha = 1.0

    this.LastFocusedHadNavWindow = false -- Instead of maintaining a LastFocusedWindow (which may harder to correctly maintain), we merely store weither NavWindow ~= nil last time the viewport was focused.
    this.PlatformMonitor = -1

    this.BgFgDrawListsLastTimeActive = {-1, -1} -- Timestamps for Gc.
    this.BgFgDrawLists = {nil, nil} -- Convenience background [1] and foreground [2] draw lists. We use them to draw software mouser cursor when io.MouseDrawCursor is set and to draw most debug overlays.
    this.DrawDataP = ImDrawData()
    this.DrawDataBuilder = ImDrawDataBuilder() -- Temporary data while building final ImDrawData

    this.LastPlatformPos  = ImVec2(FLT_MAX, FLT_MAX)
    this.LastPlatformSize = ImVec2(FLT_MAX, FLT_MAX)
    this.LastRendererSize = ImVec2(FLT_MAX, FLT_MAX)

    -- Per-viewport work area
    -- - Insets are >= 0.0 values, distance from viewport corners to work area.
    -- - BeginMainMenuBar() and DockspaceOverViewport() tend to use work area to avoid stepping over existing contents.
    -- - Generally 'safeAreaInsets' in iOS land, 'DisplayCutout' in Android land.
    this.WorkInsetMin = ImVec2(0, 0) -- Work Area inset locked for the frame. GetWorkRect() always fits within GetMainRect().
    this.WorkInsetMax = ImVec2(0, 0) -- "
    this.BuildWorkInsetMin = ImVec2(0, 0) -- Work Area inset accumulator for current frame, to become next frame's WorkInset
    this.BuildWorkInsetMax = ImVec2(0, 0) -- "

    return this
end

-------------------------------------------------------------------------------
-- [SECTION] ImFontLoader
-------------------------------------------------------------------------------

-- Hooks and storage for a given font backend.
-- This structure is likely to evolve as we add support for incremental atlas updates.
-- Conceptually this could be public, but API is still going to be evolve.
--- @class ImFontLoader
--- @field Name                       string
--- @field LoaderInit?                fun(atlas: ImFontAtlas): bool
--- @field LoaderShutdown?            fun(atlas: ImFontAtlas)
--- @field FontSrcInit?               fun(atlas: ImFontAtlas, src: ImFontConfig): bool
--- @field FontSrcDestroy?            fun(atlas: ImFontAtlas, src: ImFontConfig)
--- @field FontSrcContainsGlyph?      fun(atlas: ImFontAtlas, src: ImFontConfig, codepoint: ImWchar): bool
--- @field FontBakedInit?             fun(atlas: ImFontAtlas, src: ImFontConfig, baked: ImFontBaked, loader_data_for_baked_src?: any): bool
--- @field FontBakedDestroy?          fun(atlas: ImFontAtlas, src: ImFontConfig, baked: ImFontBaked, loader_data_for_baked_src?: any)
--- @field FontBakedLoadGlyph         fun(atlas: ImFontAtlas, src: ImFontConfig, baked: ImFontBaked, loader_data_for_baked_src?: any, codepoint: ImWchar, out_glyph?: ImFontGlyph, advance_x?: float): bool, float?
--- @field FontBakedSrcLoaderDataSize unsigned_int
MT.ImFontLoader = {}
MT.ImFontLoader.__index = MT.ImFontLoader

--- @return ImFontLoader
--- @nodiscard
function ImFontLoader()
    --- @type ImFontLoader
    local this = setmetatable({}, MT.ImFontLoader)

    this.Name                 = nil
    this.LoaderInit           = nil
    this.LoaderShutdown       = nil
    this.FontSrcInit          = nil
    this.FontSrcDestroy       = nil
    this.FontSrcContainsGlyph = nil
    this.FontBakedInit        = nil
    this.FontBakedDestroy     = nil
    this.FontBakedLoadGlyph   = nil -- Required

    -- Size of backend data, Per Baked * Per Source. Buffers are managed by core to avoid excessive allocations.
    -- FIXME: At this point the two other types of buffers may be managed by core to be consistent?
    this.FontBakedSrcLoaderDataSize = 0

    return this
end

-------------------------------------------------------------------------------
-- [SECTION] ImFontAtlas internal API
-------------------------------------------------------------------------------

-- Packed rectangle lookup entry (we need an indirection to allow removing/reordering rectangles)
-- User are returned ImFontAtlasRectId values which are meant to be persistent.
-- We handle this with an indirection. While Rects[] may be in theory shuffled, compacted etc., RectsIndex[] cannot it is keyed by ImFontAtlasRectId.
-- RectsIndex[] is used both as an index into Rects[] and an index into itself. This is basically a free-list. See ImFontAtlasBuildAllocRectIndexEntry() code.
-- Having this also makes it easier to e.g. sort rectangles during repack.
--- @class ImFontAtlasRectEntry
--- @field TargetIndex int          # 0-based! When IsUsed = true, TargetIndex = this rect's index in Rects; IsUsed = false, TargetIndex = the next unused RectsIndex entry's index
--- @field Generation  unsigned_int # How many times this entry is reused
--- @field IsUsed      bool

--- @return ImFontAtlasRectEntry
--- @nodiscard
function ImFontAtlasRectEntry()
    return {
        TargetIndex = 0,
        Generation  = 0,
        IsUsed      = false
    }
end

-- Refer to ImFontAtlasPackGetRect() to better understand how this works.
local ImFontAtlasRectId_IndexMask_       = 0x0007FFFF -- 20-bits signed: index to access builder.RectsIndex[].
local ImFontAtlasRectId_GenerationMask_  = 0x3FF00000 -- 10-bits: entry generation, so each ID is unique and get can safely detected old identifiers.
local ImFontAtlasRectId_GenerationShift_ = 20

--- @param id ImFontAtlasRectId # Expects 0-based!
--- @return int                 # 0-based!
function ImFontAtlasRectId_GetIndex(id) return bitAnd(id, ImFontAtlasRectId_IndexMask_) end

--- @param id ImFontAtlasRectId # Expects 0-based!
--- @return unsigned_int
function ImFontAtlasRectId_GetGeneration(id) return bitRShift(bitAnd(id, ImFontAtlasRectId_GenerationMask_), ImFontAtlasRectId_GenerationShift_) end

--- @param index_idx int      # Expects 0-based!
--- @param gen_idx int
--- @return ImFontAtlasRectId # 0-based!
function ImFontAtlasRectId_Make(index_idx, gen_idx)
    IM_ASSERT(index_idx >= 0 and index_idx <= ImFontAtlasRectId_IndexMask_ and gen_idx <= bitRShift(ImFontAtlasRectId_GenerationMask_, ImFontAtlasRectId_GenerationShift_))
    return bitOr(index_idx, bitLShift(gen_idx, ImFontAtlasRectId_GenerationShift_))
end

-- Data available to potential texture post-processing functions
--- @class ImFontAtlasPostProcessData
--- @field FontAtlas   ImFontAtlas
--- @field Font        ImFont
--- @field FontSrc     ImFontConfig
--- @field FontBaked   ImFontBaked
--- @field Glyph       ImFontGlyph
--- @field Pixels      unsigned_char[]
--- @field _PixelsBase int             # LUA: in cpp code the `Pixels` is a pointer. we can do this to avoid creating another custom structure to mimic it
--- @field Format      ImTextureFormat
--- @field Pitch       int
--- @field Width       int
--- @field Height      int

--- @param atlas       ImFontAtlas
--- @param font        ImFont
--- @param font_src    ImFontConfig
--- @param font_baked  ImFontBaked
--- @param glyph       ImFontGlyph
--- @param pixels      unsigned_char[]
--- @param pixels_base int
--- @param format      ImTextureFormat
--- @param pitch       int
--- @param width       int
--- @param height      int
--- @return ImFontAtlasPostProcessData
--- @nodiscard
function ImFontAtlasPostProcessData(atlas, font, font_src, font_baked, glyph, pixels, pixels_base, format, pitch, width, height)
    return {
        FontAtlas = atlas,
        Font      = font,
        FontSrc   = font_src,
        FontBaked = font_baked,
        Glyph     = glyph,

        -- Pixel data
        Pixels = pixels,
        _PixelsBase = pixels_base,
        Format = format,
        Pitch  = pitch,
        Width  = width,
        Height = height,
    }
end

-------------------------------------------------------------------------------
-- [SECTION] Inputs support
-------------------------------------------------------------------------------

--- @enum ImGuiInputSource
ImGuiInputSource = {
    None     = 0,
    Mouse    = 1, -- Note: may be Mouse or TouchScreen or Pen. See io.MouseSource to distinguish them.
    Keyboard = 2,
    Gamepad  = 3,
    COUNT    = 4
}

--- @class ImGuiInputEventMousePos
--- @field PosX float
--- @field PosY float
--- @field MouseSource ImGuiMouseSource

--- @return ImGuiInputEventMousePos
--- @nodiscard
function ImGuiInputEventMousePos()
    return { PosX = 0, PosY = 0, MouseSource = ImGuiMouseSource.Mouse }
end

--- @class ImGuiInputEventMouseButton
--- @field Button int
--- @field Down   bool
--- @field MouseSource ImGuiMouseSource

--- @return ImGuiInputEventMouseButton
--- @nodiscard
function ImGuiInputEventMouseButton()
    return { Button = 0, Down = false, MouseSource = ImGuiMouseSource.Mouse }
end

--- @class ImGuiInputEventMouseWheel
--- @field WheelX float
--- @field WheelY float
--- @field MouseSource ImGuiMouseSource

--- @return ImGuiInputEventMouseWheel
--- @nodiscard
function ImGuiInputEventMouseWheel()
    return { WheelX = 0, WheelY = 0, MouseSource = ImGuiMouseSource.Mouse }
end

--- @class ImGuiInputEventKey
--- @field Key         ImGuiKey
--- @field Down        bool
--- @field AnalogValue float

--- @return ImGuiInputEventKey
--- @nodiscard
function ImGuiInputEventKey()
    return { Key = 0, Down = false, AnalogValue = 0 }
end

--- @class ImGuiInputEventText
--- @field Char unsigned_int

--- @return ImGuiInputEventText
--- @nodiscard
function ImGuiInputEventText()
    return { Char = nil }
end

--- @class ImGuiInputEventAppFocused
--- @field Focused bool

--- @return ImGuiInputEventAppFocused
--- @nodiscard
function ImGuiInputEventAppFocused()
    return { Focused = nil }
end

--- @class ImGuiInputEventMouseViewport
--- @field HoveredViewportID ImGuiID

--- @return ImGuiInputEventMouseViewport
--- @nodiscard
function ImGuiInputEventMouseViewport()
    return { HoveredViewportID = 0 }
end

--- @class ImGuiInputEvent

--- @return ImGuiInputEvent
--- @nodiscard
function ImGuiInputEvent()
    return {
        Type    = 0,
        Source  = 0,
        EventId = 0, -- Unique, sequential increasing integer to identify an event (if you need to correlate them to other data).

        -- union
        MousePos      = nil, -- if Type == ImGuiInputEventType.MousePos
        MouseWheel    = nil, -- if Type == ImGuiInputEventType.MouseWheel
        MouseButton   = nil, -- if Type == ImGuiInputEventType.MouseButton
        MouseViewport = nil, -- if Type == ImGuiInputEventType.MouseViewport
        Key           = nil, -- if Type == ImGuiInputEventType.Key
        Text          = nil, -- if Type == ImGuiInputEventType.Text
        AppFocused    = nil, -- if Type == ImGuiInputEventType.Focus
    }
end

-- [Internal] Key ranges
ImGuiKey_Keyboard_BEGIN = ImGuiKey.NamedKey_BEGIN
ImGuiKey_Keyboard_END   = ImGuiKey.GamepadStart
ImGuiKey_Gamepad_BEGIN  = ImGuiKey.GamepadStart
ImGuiKey_Gamepad_END    = ImGuiKey.GamepadRStickDown + 1
ImGuiKey_Mouse_BEGIN    = ImGuiKey.MouseLeft
ImGuiKey_Mouse_END      = ImGuiKey.MouseWheelY + 1
ImGuiKey_Aliases_BEGIN  = ImGuiKey_Mouse_BEGIN
ImGuiKey_Aliases_END    = ImGuiKey_Mouse_END

-- [Internal] Named shortcuts for Navigation
ImGuiKey.NavKeyboardTweakSlow = ImGuiMod_Ctrl
ImGuiKey.NavKeyboardTweakFast = ImGuiMod_Shift
ImGuiKey.NavGamepadTweakSlow = ImGuiKey.GamepadL1
ImGuiKey.NavGamepadTweakFast = ImGuiKey.GamepadR1
ImGuiKey.NavGamepadMenu = ImGuiKey.GamepadFaceLeft -- Toggle menu layer. Hold to enable Windowing.
ImGuiKey.NavGamepadContextMenu = ImGuiKey.GamepadFaceUp -- Open context menu (same as Shift+F10)

--- @enum ImGuiInputEventType
ImGuiInputEventType = {
    None          = 0,
    MousePos      = 1,
    MouseWheel    = 2,
    MouseButton   = 3,
    MouseViewport = 4,
    Key           = 5,
    Text          = 6,
    Focus         = 7,
    COUNT         = 8
}

-- Extend ImGuiInputFlags
-- Flags for extended versions of IsKeyPressed(), IsMouseClicked(), Shortcut(), SetKeyOwner(), SetItemKeyOwner()
-- Don't mistake with ImGuiInputTextFlags! (which is for ImGui.InputText() function)

-- Flags for IsKeyPressed(), IsKeyChordPressed(), IsMouseClicked(), Shortcut()
-- - Repeat mode: Repeat rate selection
ImGuiInputFlags.RepeatRateDefault                = bitLShift(1, 1) -- Repeat rate: Regular (default)
ImGuiInputFlags.RepeatRateNavMove                = bitLShift(1, 2) -- Repeat rate: Fast
ImGuiInputFlags.RepeatRateNavTweak               = bitLShift(1, 3) -- Repeat rate: Faster
-- - Repeat mode: Specify when repeating key pressed can be interrupted.
-- - In theory ImGuiInputFlags.RepeatUntilOtherKeyPress may be a desirable default, but it would break too many behavior so everything is opt-in.
ImGuiInputFlags.RepeatUntilRelease               = bitLShift(1, 4) -- Stop repeating when released (default for all functions except Shortcut). This only exists to allow overriding Shortcut() default behavior.
ImGuiInputFlags.RepeatUntilKeyModsChange         = bitLShift(1, 5) -- Stop repeating when released OR if keyboard mods are changed (default for Shortcut)
ImGuiInputFlags.RepeatUntilKeyModsChangeFromNone = bitLShift(1, 6) -- Stop repeating when released OR if keyboard mods are leaving the None state. Allows going from Mod+Key to Key by releasing Mod.
ImGuiInputFlags.RepeatUntilOtherKeyPress         = bitLShift(1, 7) -- Stop repeating when released OR if any other keyboard key is pressed during the repeat

-- Flags for SetKeyOwner(), SetItemKeyOwner()
-- - Locking key away from non-input aware code. Locking is useful to make input-owner-aware code steal keys from non-input-owner-aware code. If all code is input-owner-aware locking would never be necessary.
ImGuiInputFlags.LockThisFrame                    = bitLShift(1, 20) -- Further accesses to key data will require EXPLICIT owner ID (ImGuiKeyOwner_Any/0 will NOT accepted for polling). Cleared at end of frame.
ImGuiInputFlags.LockUntilRelease                 = bitLShift(1, 21) -- Further accesses to key data will require EXPLICIT owner ID (ImGuiKeyOwner_Any/0 will NOT accepted for polling). Cleared when the key is released or at end of each frame if key is released.

-- - Condition for SetItemKeyOwner()
ImGuiInputFlags.CondHovered                      = bitLShift(1, 22) -- Only set if item is hovered (default to both)
ImGuiInputFlags.CondActive                       = bitLShift(1, 23) -- Only set if item is active (default to both)

ImGuiInputFlags.CondDefault_                   = bitOr(ImGuiInputFlags.CondHovered, ImGuiInputFlags.CondActive)
-- [Internal] Mask of which function support which flags
ImGuiInputFlags.RepeatRateMask_                = bitOr(ImGuiInputFlags.RepeatRateDefault, ImGuiInputFlags.RepeatRateNavMove, ImGuiInputFlags.RepeatRateNavTweak)
ImGuiInputFlags.RepeatUntilMask_               = bitOr(ImGuiInputFlags.RepeatUntilRelease, ImGuiInputFlags.RepeatUntilKeyModsChange, ImGuiInputFlags.RepeatUntilKeyModsChangeFromNone, ImGuiInputFlags.RepeatUntilOtherKeyPress)
ImGuiInputFlags.RepeatMask_                    = bitOr(ImGuiInputFlags.Repeat, ImGuiInputFlags.RepeatRateMask_, ImGuiInputFlags.RepeatUntilMask_)
ImGuiInputFlags.CondMask_                      = bitOr(ImGuiInputFlags.CondHovered, ImGuiInputFlags.CondActive)
ImGuiInputFlags.RouteTypeMask_                 = bitOr(ImGuiInputFlags.RouteActive, ImGuiInputFlags.RouteFocused, ImGuiInputFlags.RouteGlobal, ImGuiInputFlags.RouteAlways)
ImGuiInputFlags.RouteOptionsMask_              = bitOr(ImGuiInputFlags.RouteOverFocused, ImGuiInputFlags.RouteOverActive, ImGuiInputFlags.RouteUnlessBgFocused, ImGuiInputFlags.RouteFromRootWindow)
ImGuiInputFlags.SupportedByIsKeyPressed        = ImGuiInputFlags.RepeatMask_
ImGuiInputFlags.SupportedByIsMouseClicked      = ImGuiInputFlags.Repeat
ImGuiInputFlags.SupportedByShortcut            = bitOr(ImGuiInputFlags.RepeatMask_, ImGuiInputFlags.RouteTypeMask_, ImGuiInputFlags.RouteOptionsMask_)
ImGuiInputFlags.SupportedBySetNextItemShortcut = bitOr(ImGuiInputFlags.RepeatMask_, ImGuiInputFlags.RouteTypeMask_, ImGuiInputFlags.RouteOptionsMask_, ImGuiInputFlags.Tooltip)
ImGuiInputFlags.SupportedBySetKeyOwner         = bitOr(ImGuiInputFlags.LockThisFrame, ImGuiInputFlags.LockUntilRelease)
ImGuiInputFlags.SupportedBySetItemKeyOwner     = bitOr(ImGuiInputFlags.SupportedBySetKeyOwner, ImGuiInputFlags.CondMask_)

--- @enum ImGuiAxis # can be used to index ImVec2
ImGuiAxis =
{
    None = 0,
    X    = 1,
    Y    = 2
}

--- @enum ImGuiPlotType
ImGuiPlotType =
{
    Lines     = 0,
    Histogram = 1
}

-------------------------------------------------------------------------------
-- [SECTION] Navigation support
-------------------------------------------------------------------------------

--- @enum ImGuiActivateFlags
ImGuiActivateFlags = {
    None               = 0,
    PreferInput        = bitLShift(1, 0), -- Favor activation that requires keyboard text input (e.g. for Slider/Drag). Default for Enter key.
    PreferTweak        = bitLShift(1, 1), -- Favor activation for tweaking with arrows or gamepad (e.g. for Slider/Drag). Default for Space key and if keyboard is not used.
    TryToPreserveState = bitLShift(1, 2), -- Request widget to preserve state if it can (e.g. InputText will try to preserve cursor/selection)
    FromTabbing        = bitLShift(1, 3), -- Activation requested by a tabbing request (ImGuiNavMoveFlags.IsTabbing)
    FromShortcut       = bitLShift(1, 4), -- Activation requested by an item shortcut via SetNextItemShortcut() function.
    FromFocusApi       = bitLShift(1, 5)  -- Activation requested by an api request (ImGuiNavMoveFlags.FocusApi)
}

-- Early work-in-progress API for ScrollToItem()
-- FIXME: Missing flags to request making both edges visible when possible.
--- @enum ImGuiScrollFlags
ImGuiScrollFlags = {
    None               = 0,
    KeepVisibleEdgeX   = bitLShift(1, 0), -- If item is not visible: scroll as little as possible on X axis to bring item back into view [default for X axis]
    KeepVisibleEdgeY   = bitLShift(1, 1), -- If item is not visible: scroll as little as possible on Y axis to bring item back into view [default for Y axis for windows that are already visible]
    KeepVisibleCenterX = bitLShift(1, 2), -- If item is not visible: scroll to make the item centered on X axis [rarely used]
    KeepVisibleCenterY = bitLShift(1, 3), -- If item is not visible: scroll to make the item centered on Y axis
    AlwaysCenterX      = bitLShift(1, 4), -- Always center the result item on X axis [rarely used]
    AlwaysCenterY      = bitLShift(1, 5), -- Always center the result item on Y axis [default for Y axis for appearing window)
    NoScrollParent     = bitLShift(1, 6), -- Disable forwarding scrolling to parent window if required to keep item/rect visible (only scroll window the function was applied to).
}

ImGuiScrollFlags.MaskX_ = bitOr(ImGuiScrollFlags.KeepVisibleEdgeX, ImGuiScrollFlags.KeepVisibleCenterX, ImGuiScrollFlags.AlwaysCenterX)
ImGuiScrollFlags.MaskY_ = bitOr(ImGuiScrollFlags.KeepVisibleEdgeY, ImGuiScrollFlags.KeepVisibleCenterY, ImGuiScrollFlags.AlwaysCenterY)

-- Stacked storage data for BeginGroup()/EndGroup()
--- @class ImGuiGroupData
--- @field WindowID                          ImGuiID
--- @field BackupCursorPos                   ImVec2
--- @field BackupCursorMaxPos                ImVec2
--- @field BackupCursorPosPrevLine           ImVec2
--- @field BackupIndent                      ImVec1
--- @field BackupGroupOffset                 ImVec1
--- @field BackupCurrLineSize                ImVec2
--- @field BackupCurrLineTextBaseOffset      float
--- @field BackupActiveIdIsAlive             ImGuiID
--- @field BackupAnyIdHasBeenEditedThisFrame bool
--- @field BackupDeactivatedIdIsAlive        bool
--- @field BackupHoveredIdIsAlive            bool
--- @field BackupIsSameLine                  bool
--- @field EmitItem                          bool

--- @return ImGuiGroupData
--- @nodiscard
function ImGuiGroupData()
    return
    {
        WindowID                          = nil,
        BackupCursorPos                   = ImVec2(),
        BackupCursorMaxPos                = ImVec2(),
        BackupCursorPosPrevLine           = ImVec2(),
        BackupIndent                      = ImVec1(),
        BackupGroupOffset                 = ImVec1(),
        BackupCurrLineSize                = ImVec2(),
        BackupCurrLineTextBaseOffset      = nil,
        BackupActiveIdIsAlive             = nil,
        BackupAnyIdHasBeenEditedThisFrame = nil,
        BackupDeactivatedIdIsAlive        = nil,
        BackupHoveredIdIsAlive            = nil,
        BackupIsSameLine                  = nil,
        EmitItem                          = nil
    }
end

--- @enum ImGuiTooltipFlags
ImGuiTooltipFlags =
{
    None             = 0,
    OverridePrevious = bitLShift(1, 1) -- Clear/ignore previously submitted tooltip (defaults to append)
}

-------------------------------------------------------------------------------
-- [SECTION] Popup support
-------------------------------------------------------------------------------

--- @enum ImGuiPopupPositionPolicy
ImGuiPopupPositionPolicy =
{
    Default  = 0,
    ComboBox = 1,
    Tooltip  = 2
}

-- Storage for popup stacks (g.OpenPopupStack and g.BeginPopupStack)
--- @class ImGuiPopupData
--- @field PopupId          ImGuiID
--- @field Window           ImGuiWindow
--- @field RestoreNavWindow ImGuiWindow
--- @field ParentNavLayer   int
--- @field OpenFrameCount   int
--- @field OpenParentId     ImGuiID
--- @field OpenPopupPos     ImVec2
--- @field OpenMousePos     ImVec2

--- @return ImGuiPopupData
--- @nodiscard
function ImGuiPopupData()
    return {
        PopupId          = 0,   -- Set on OpenPopup()
        Window           = nil, -- Resolved on BeginPopup() - may stay unresolved if user never calls OpenPopup()
        RestoreNavWindow = nil, -- Set on OpenPopup(), a NavWindow that will be restored on popup close
        ParentNavLayer   = -1,  -- Resolved on BeginPopup(). Actually a ImGuiNavLayer type (declared down below), initialized to -1 which is not part of an enum, but serves well-enough as "not any of layers" value
        OpenFrameCount   = -1,  -- Set on OpenPopup()
        OpenParentId     = 0,   -- Set on OpenPopup(), we need this to differentiate multiple menu sets from each others (e.g. inside menu bar vs loose menu items)
        OpenPopupPos     = ImVec2(), -- Set on OpenPopup(), preferred popup position (typically == OpenMousePos when using mouse)
        OpenMousePos     = ImVec2()  -- Set on OpenPopup(), copy of mouse position at the time of opening popup
    }
end

--- @enum ImGuiWindowRefreshFlags
ImGuiWindowRefreshFlags = {
    None              = 0,
    TryToAvoidRefresh = bitLShift(1, 0), -- [EXPERIMENTAL] Try to keep existing contents, USER MUST NOT HONOR BEGIN() RETURNING FALSE AND NOT APPEND.
    RefreshOnHover    = bitLShift(1, 1), -- [EXPERIMENTAL] Always refresh on hover
    RefreshOnFocus    = bitLShift(1, 2)  -- [EXPERIMENTAL] Always refresh on focus
    -- Refresh policy/frequency, Load Balancing etc.
}

--- @enum ImGuiNavRenderCursorFlags
ImGuiNavRenderCursorFlags = {
    None       = 0,
    Compact    = bitLShift(1, 1), -- Compact highlight, no padding/distance from focused item
    AlwaysDraw = bitLShift(1, 2), -- Draw rectangular highlight if (g.NavId == id) even when g.NavCursorVisible == false, aka even when using the mouse.
}

-------------------------------------------------------------------------------
-- [SECTION] Metrics, Debug Tools
-------------------------------------------------------------------------------

-- See IMGUI_DEBUG_LOG() and IMGUI_DEBUG_LOG_XXX() macros.
--- @enum ImGuiDebugLogFlags
ImGuiDebugLogFlags = {
    -- Event types
    None              = 0,
    EventError        = bitLShift(1, 0), -- Error submitted by IM_ASSERT_USER_ERROR()
    EventActiveId     = bitLShift(1, 1),
    EventFocus        = bitLShift(1, 2),
    EventPopup        = bitLShift(1, 3),
    EventNav          = bitLShift(1, 4),
    EventClipper      = bitLShift(1, 5),
    EventSelection    = bitLShift(1, 6),
    EventIO           = bitLShift(1, 7),
    EventFont         = bitLShift(1, 8),
    EventInputRouting = bitLShift(1, 9),
    EventDocking      = bitLShift(1, 10),
    EventViewport     = bitLShift(1, 11),
    EventTable        = bitLShift(1, 12),

    OutputToTTY        = bitLShift(1, 20), -- Also send output to TTY
    OutputToDebugger   = bitLShift(1, 21),
    OutputToTestEngine = bitLShift(1, 22),
}

ImGuiDebugLogFlags.EventMask_ = bitOr(
    ImGuiDebugLogFlags.EventError,
    ImGuiDebugLogFlags.EventActiveId,
    ImGuiDebugLogFlags.EventFocus,
    ImGuiDebugLogFlags.EventPopup,
    ImGuiDebugLogFlags.EventNav,
    ImGuiDebugLogFlags.EventClipper,
    ImGuiDebugLogFlags.EventSelection,
    ImGuiDebugLogFlags.EventTable,
    ImGuiDebugLogFlags.EventIO,
    ImGuiDebugLogFlags.EventFont,
    ImGuiDebugLogFlags.EventInputRouting,
    ImGuiDebugLogFlags.EventDocking,
    ImGuiDebugLogFlags.EventViewport
)

-------------------------------------------------------------------------------
-- [SECTION] Localization support
-------------------------------------------------------------------------------

-- This is experimental and not officially supported, it'll probably fall short of features, if/when it does we may backtrack.
--- @enum ImGuiLocKey
ImGuiLocKey = {
    VersionStr                    = 1,
    TableSizeOne                  = 2,
    TableSizeAllFit               = 3,
    TableSizeAllDefault           = 4,
    TableReset                    = 5,
    TableResetOrder               = 6,
    TableResetVisibility          = 7,
    WindowingMainMenuBar          = 8,
    WindowingPopup                = 9,
    WindowingUntitled             = 10,
    OpenLink_s                    = 11,
    CopyLink                      = 12,
    DockingHideTabBar             = 13,
    DockingHoldShiftToDock        = 14,
    DockingDragToUndockOrMoveNode = 15,
    COUNT                         = 15
}

--- @class ImGuiLocEntry
--- @field Key  ImGuiLocKey
--- @field Text string

--- @param key ImGuiLocKey
--- @return string
function ImGui.LocalizeGetMsg(key)
    local g = GImGui
    local msg = g.LocalizationTable[key]
    if msg then return msg else return "*Missing Text*" end
end

--- @param id ImGuiID
function ImGui.TempInputIsActive(id)
    local g = GImGui
    return (g.TempInputId == id and g.ActiveId == id) or (g.InputTextDeactivatedState.ID == id)
end

-- Get input text state if active
--- @param id ImGuiID
--- @return ImGuiInputTextState?
function ImGui.GetInputTextState(id)
    local g = GImGui
    if id ~= 0 and g.InputTextState.ID == id then
        return g.InputTextState
    end
    return nil
end

-- Storage for PushFocusScope(), g.FocusScopeStack[], g.NavFocusRoute[]
--- @class ImGuiFocusScopeData
--- @field ID       ImGuiID
--- @field WindowID ImGuiID

--- @return ImGuiFocusScopeData
--- @nodiscard
function ImGuiFocusScopeData() return { ID = nil, WindowID = nil } end


return true -- [Roblox] ModuleScripts must return exactly one value
end

__FILES['imgui_tables.lua'] = function()
--- Dear ImGui WIP
-- (tables and columns code)
-- 1:1 port of imgui_tables.cpp (docking branch, 1.93 WIP)

-- Index of this file:
--
-- [SECTION] Commentary
-- [SECTION] Structs (port: struct constructors from imgui_internal.h / imgui.h)
-- [SECTION] Tables: Main code
-- [SECTION] Tables: Simple accessors
-- [SECTION] Tables: Row changes
-- [SECTION] Tables: Columns changes
-- [SECTION] Tables: Columns width management
-- [SECTION] Tables: Drawing
-- [SECTION] Tables: Sorting
-- [SECTION] Tables: Headers
-- [SECTION] Tables: Context Menu
-- [SECTION] Tables: Settings (.ini data)
-- [SECTION] Tables: Garbage Collection
-- [SECTION] Columns, BeginColumns, EndColumns, etc.

-------------------------------------------------------------------------------
-- [SECTION] Commentary
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
-- Typical tables call flow: (root level is generally public API):
-------------------------------------------------------------------------------
-- - BeginTable()                               user begin into a table
--    | BeginChild()                            - (if ScrollX/ScrollY is set)
--    | TableBeginInitMemory()                  - first time table is used
--    | TableResetSettings()                    - on settings reset
--    | TableLoadSettings()                     - on settings load
-------------------------------------------------------------------------------
-- - TableSetupColumn()                         user submit columns details (optional)
-- - TableSetupScrollFreeze()                   user submit scroll freeze information (optional)
-------------------------------------------------------------------------------
-- - TableUpdateLayout() [Internal]             followup to BeginTable(): setup everything: widths, columns positions, clipping rectangles. Automatically called by the FIRST call to TableNextRow() or TableHeadersRow().
--    | TableApplyQueuedRequests()              - apply queued resizing/reordering/hiding requests
--    | - TableSetColumnWidth()                 - apply resizing width (for mouse resize, often requested by previous frame)
--    |    - TableUpdateColumnsWeightFromWidth()- recompute columns weights (of stretch columns) from their respective width
--    | - TableSetColumnDisplayOrder()          - apply reordering a column
--    | TableSetupDrawChannels()                - setup ImDrawList channels
--    | TableUpdateBorders()                    - detect hovering columns for resize, ahead of contents submission
--    | TableBeginContextMenuPopup()
--    | - TableDrawDefaultContextMenu()         - draw right-click context menu contents
-------------------------------------------------------------------------------
-- - TableHeadersRow() or TableHeader()         user submit a headers row (optional)
--    | TableSortSpecsClickColumn()             - when left-clicked: alter sort order and sort direction
--    | TableOpenContextMenu()                  - when right-clicked: trigger opening of the default context menu
-- - TableGetSortSpecs()                        user queries updated sort specs (optional, generally after submitting headers)
-- - TableNextRow()                             user begin into a new row (also automatically called by TableHeadersRow())
--    | TableEndRow()                           - finish existing row
--    | TableBeginRow()                         - add a new row
-- - TableSetColumnIndex() / TableNextColumn()  user begin into a cell
--    | TableEndCell()                          - close existing column/cell
--    | TableBeginCell()                        - enter into current column/cell
-- - [...]                                      user emit contents
-------------------------------------------------------------------------------
-- - EndTable()                                 user ends the table
--    | TableDrawBorders()                      - draw outer borders, inner vertical borders
--    | TableMergeDrawChannels()                - merge draw channels if clipping isn't required
--    | EndChild()                              - (if ScrollX/ScrollY is set)
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
-- TABLE SIZING
-------------------------------------------------------------------------------
-- (Read carefully because this is subtle but it does make sense!)
-------------------------------------------------------------------------------
-- About 'outer_size':
-- Its meaning needs to differ slightly depending on if we are using ScrollX/ScrollY flags.
-- Default value is ImVec2(0.0, 0.0).
--   X
--   - outer_size.x <= 0.0  ->  Right-align from window/work-rect right-most edge. With -FLT_MIN or 0.0 will align exactly on right-most edge.
--   - outer_size.x  > 0.0  ->  Set Fixed width.
--   Y with ScrollX/ScrollY disabled: we output table directly in current window
--   - outer_size.y  < 0.0  ->  Bottom-align (but will auto extend, unless _NoHostExtendY is set). Not meaningful if parent window can vertically scroll.
--   - outer_size.y  = 0.0  ->  No minimum height (but will auto extend, unless _NoHostExtendY is set)
--   - outer_size.y  > 0.0  ->  Set Minimum height (but will auto extend, unless _NoHostExtendY is set)
--   Y with ScrollX/ScrollY enabled: using a child window for scrolling
--   - outer_size.y  < 0.0  ->  Bottom-align. Not meaningful if parent window can vertically scroll.
--   - outer_size.y  = 0.0  ->  Bottom-align, consistent with BeginChild(). Not recommended unless table is last item in parent window.
--   - outer_size.y  > 0.0  ->  Set Exact height. Recommended when using Scrolling on any axis.
-------------------------------------------------------------------------------
-- Outer size is also affected by the NoHostExtendX/NoHostExtendY flags.
-- Important to note how the two flags have slightly different behaviors!
--   - ImGuiTableFlags.NoHostExtendX -> Make outer width auto-fit to columns (overriding outer_size.x value). Only available when ScrollX/ScrollY are disabled and Stretch columns are not used.
--   - ImGuiTableFlags.NoHostExtendY -> Make outer height stop exactly at outer_size.y (prevent auto-extending table past the limit). Only available when ScrollX/ScrollY is disabled. Data below the limit will be clipped and not visible.
-- In theory ImGuiTableFlags.NoHostExtendY could be the default and any non-scrolling tables with outer_size.y ~= 0.0 would use exact height.
-- This would be consistent but perhaps less useful and more confusing (as vertically clipped items are not useful and not easily noticeable).
-------------------------------------------------------------------------------
-- About 'inner_width':
--   With ScrollX disabled:
--   - inner_width          ->  *ignored*
--   With ScrollX enabled:
--   - inner_width  < 0.0  ->  *illegal* fit in known width (right align from outer_size.x) <-- weird
--   - inner_width  = 0.0  ->  fit in outer_width: Fixed size columns will take space they need (if avail, otherwise shrink down), Stretch columns becomes Fixed columns.
--   - inner_width  > 0.0  ->  override scrolling width, generally to be larger than outer_size.x. Fixed column take space they need (if avail, otherwise shrink down), Stretch columns share remaining space!
-------------------------------------------------------------------------------
-- Details:
-- - If you want to use Stretch columns with ScrollX, you generally need to specify 'inner_width' otherwise the concept
--   of "available space" doesn't make sense.
-- - Even if not really useful, we allow 'inner_width < outer_size.x' for consistency and to facilitate understanding
--   of what the value does.
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
-- COLUMNS SIZING POLICIES
-- (Reference: ImGuiTableFlags.SizingXXX flags and ImGuiTableColumnFlags.WidthXXX flags)
-------------------------------------------------------------------------------
-- About overriding column sizing policy and width/weight with TableSetupColumn():
-- We use a default parameter of -1 for 'init_width'/'init_weight'.
--   - with ImGuiTableColumnFlags.WidthFixed,    init_width  <= 0 (default)  --> width is automatic
--   - with ImGuiTableColumnFlags.WidthFixed,    init_width  >  0 (explicit) --> width is custom
--   - with ImGuiTableColumnFlags.WidthStretch,  init_weight <= 0 (default)  --> weight is 1.0
--   - with ImGuiTableColumnFlags.WidthStretch,  init_weight >  0 (explicit) --> weight is custom
-- Widths are specified _without_ CellPadding. If you specify a width of 100.0, the column will be cover (100.0 + Padding * 2.0)
-- and you can fit a 100.0 wide item in it without clipping and with padding honored.
-------------------------------------------------------------------------------
-- About default sizing policy (if you don't specify a ImGuiTableColumnFlags.WidthXXXX flag)
--   - with Table policy ImGuiTableFlags.SizingFixedFit      --> default Column policy is ImGuiTableColumnFlags.WidthFixed, default Width is equal to contents width
--   - with Table policy ImGuiTableFlags.SizingFixedSame     --> default Column policy is ImGuiTableColumnFlags.WidthFixed, default Width is max of all contents width
--   - with Table policy ImGuiTableFlags.SizingStretchSame   --> default Column policy is ImGuiTableColumnFlags.WidthStretch, default Weight is 1.0
--   - with Table policy ImGuiTableFlags.SizingStretchWeight --> default Column policy is ImGuiTableColumnFlags.WidthStretch, default Weight is proportional to contents
-- Default Width and default Weight can be overridden when calling TableSetupColumn().
-------------------------------------------------------------------------------
-- About mixing Fixed/Auto and Stretch columns together:
--   - the typical use of mixing sizing policies is: any number of LEADING Fixed columns, followed by one or two TRAILING Stretch columns.
--   - using mixed policies with ScrollX does not make much sense, as using Stretch columns with ScrollX does not make much sense in the first place!
--     that is, unless 'inner_width' is passed to BeginTable() to explicitly provide a total width to layout columns in.
--   - when using ImGuiTableFlags.SizingFixedSame with mixed columns, only the Fixed/Auto columns will match their widths to the width of the maximum contents.
--   - when using ImGuiTableFlags.SizingStretchSame with mixed columns, only the Stretch columns will match their weights/widths.
-------------------------------------------------------------------------------
-- About using column width:
-- If a column is manually resizable or has a width specified with TableSetupColumn():
--   - you may use GetContentRegionAvail().x to query the width available in a given column.
--   - right-side alignment features such as SetNextItemWidth(-x) or PushItemWidth(-x) will rely on this width.
-- If the column is not resizable and has no width specified with TableSetupColumn():
--   - its width will be automatic and be set to the max of items submitted.
--   - therefore you generally cannot have ALL items of the columns use e.g. SetNextItemWidth(-FLT_MIN).
--   - but if the column has one or more items of known/fixed size, this will become the reference width used by SetNextItemWidth(-FLT_MIN).
-------------------------------------------------------------------------------


-------------------------------------------------------------------------------
-- TABLES CLIPPING/CULLING
-------------------------------------------------------------------------------
-- About clipping/culling of Rows in Tables:
-- - For large numbers of rows, it is recommended you use ImGuiListClipper to submit only visible rows.
--   ImGuiListClipper is reliant on the fact that rows are of equal height.
--   See 'Demo->Tables->Vertical Scrolling' or 'Demo->Tables->Advanced' for a demo of using the clipper.
-- - Note that auto-resizing columns don't play well with using the clipper.
--   By default a table with _ScrollX but without _Resizable will have column auto-resize.
--   So, if you want to use the clipper, make sure to either enable _Resizable, either setup columns width explicitly with _WidthFixed.
-------------------------------------------------------------------------------
-- About clipping/culling of Columns in Tables:
-- - Both TableSetColumnIndex() and TableNextColumn() return true when the column is visible or performing
--   width measurements. Otherwise, you may skip submitting the contents of a cell/column, BUT ONLY if you know
--   it is not going to contribute to row height.
--   In many situations, you may skip submitting contents for every column but one (e.g. the first one).
-- - Case A: column is not hidden by user, and at least partially in sight (most common case).
-- - Case B: column is clipped / out of sight (because of scrolling or parent ClipRect): TableNextColumn() return false as a hint but we still allow layout output.
-- - Case C: column is hidden explicitly by the user (e.g. via the context menu, or _DefaultHide column flag, etc.).
--
--                        [A]         [B]          [C]
--  TableNextColumn():    true        false        false       -> [userland] when TableNextColumn() / TableSetColumnIndex() returns false, user can skip submitting items but only if the column doesn't contribute to row height.
--          SkipItems:    false       false        true        -> [internal] when SkipItems is true, most widgets will early out if submitted, resulting is no layout output.
--           ClipRect:    normal      zero-width   zero-width  -> [internal] when ClipRect is zero, ItemAdd() will return false and most widgets will early out mid-way.
--  ImDrawList output:    normal      dummy        dummy       -> [internal] when using the dummy channel, ImDrawList submissions (if any) will be wasted (because cliprect is zero-width anyway).
--
-- - We need to distinguish those cases because non-hidden columns that are clipped outside of scrolling bounds should still contribute their height to the row.
--   However, in the majority of cases, the contribution to row height is the same for all columns, or the tallest cells are known by the programmer.
-------------------------------------------------------------------------------
-- About clipping/culling of whole Tables:
-- - Scrolling tables with a known outer size can be clipped earlier as BeginTable() will return false.
-------------------------------------------------------------------------------

-- Port notes:
-- - Column indices / display orders / draw channel indices are 0-based VALUES like upstream.
--   Per-column arrays (table.Columns, table.DisplayOrderToIndex, table.RowCellData) are Lua tables with 0-based keys.
--   table.ColumnsSize mirrors upstream `table->Columns.size()`.
-- - ImBitArray masks are Lua tables { [n] = true }.
-- - table.ColumnsNames is a Lua array of strings, column.NameOffset is a 0-based index into it (-1 = none).
-- - g.SettingsTables is a plain vector of ImGuiTableSettings; table.SettingsOffset is a 1-based index into it (-1 = none).
--   Each settings entry owns `Columns` (0-based Lua table of ImGuiTableColumnSettings).
-- - ImGuiTableSortSpecs.Specs is a 1-based Lua array of ImGuiTableColumnSortSpecs.

--- @type ImGuiContext?
local GImGui

local MT = ImGui.GetMetatables()

-- Sets local `GImGui` in this file(imgui_tables.lua).
-- This is currently only used in main code `ImGui.SetCurrentContext()`
--- @param ctx ImGuiContext?
function ImGui._SetCurrentContext_Tables(ctx)
    GImGui = ctx
end

local bit32 = bit32
local band, bor, bnot, lshift, rshift = bit32.band, bit32.bor, bit32.bnot, bit32.lshift, bit32.rshift
local mathMax, mathMin = math.max, math.min -- [Luau] scalar ImMax()/ImMin() in table code are written as mathMax()/mathMin() (no call through the vector-aware helper)

IM_COL32_DISABLE = IM_COL32(0, 0, 0, 1) -- Special sentinel code which cannot be used as a regular color.
IMGUI_TABLE_MAX_COLUMNS = 512 -- Arbitrary "safety" maximum, may be lifted in the future if needed. Must fit in ImGuiTableColumnIdx/ImGuiTableDrawChannelIdx.

local function IMGUI_DEBUG_LOG_TABLE(fmt, ...)
    local g = GImGui
    if band(g.DebugLogFlags, ImGuiDebugLogFlags.EventTable) ~= 0 then ImGui.DebugLog(fmt, ...) end
end

-------------------------------------------------------------------------------
-- [SECTION] Structs
-------------------------------------------------------------------------------

local function BitArrayClearAll(arr) table.clear(arr) end
local function BitArraySet(arr, n) arr[n] = true end
local function BitTest(arr, n) return arr[n] == true end

-- Sorting specification for one column of a table
--- @class ImGuiTableColumnSortSpecs
function ImGuiTableColumnSortSpecs()
    return { ColumnUserID = 0, ColumnIndex = 0, SortOrder = 0, SortDirection = ImGuiSortDirection.None }
end

-- Sorting specifications for a table (often handling sort specs for a single column, occasionally more)
-- Obtained by calling TableGetSortSpecs().
-- When 'SpecsDirty == true' you can sort your data. It will be true with sorting specs have changed since last call, or the first time.
-- Make sure to set 'SpecsDirty = false' after sorting, else you may wastefully sort your data every frame!
--- @class ImGuiTableSortSpecs
function ImGuiTableSortSpecs()
    return { Specs = nil, SpecsCount = 0, SpecsDirty = false }
end

-- We use the terminology "Enabled" to refer to a column that is not Hidden by user/api.
-- We use the terminology "Clipped" to refer to a column that is out of sight because of scrolling/clipping.
-- This is in contrast with some user-facing api such as IsItemVisible() / IsRectVisible() which use "Visible" to mean "not clipped".
--- @class ImGuiTableColumn
function ImGuiTableColumn()
    return {
        Flags = 0, WidthGiven = 0.0, MinX = 0.0, MaxX = 0.0, WidthRequest = -1.0, WidthAuto = 0.0, WidthMax = 0.0,
        StretchWeight = -1.0, InitStretchWeightOrWidth = 0.0, ClipRect = ImRect(), ID = 0, UserData = 0,
        WorkMinX = 0.0, WorkMaxX = 0.0, ItemWidth = 0.0, ContentMaxXFrozen = 0.0, ContentMaxXUnfrozen = 0.0,
        ContentMaxXHeadersUsed = 0.0, ContentMaxXHeadersIdeal = 0.0, NameOffset = -1, DisplayOrder = -1,
        IndexWithinEnabledSet = -1, PrevEnabledColumn = -1, NextEnabledColumn = -1, SortOrder = -1,
        DrawChannelCurrent = -1, DrawChannelFrozen = -1, DrawChannelUnfrozen = -1,
        IsEnabled = false, IsUserEnabled = false, IsUserEnabledNextFrame = false, IsVisibleX = false, IsVisibleY = false,
        IsRequestOutput = false, IsSkipItems = false, IsPreserveWidthAuto = false, IsJustCreated = true,
        IsLoadedSettings = false, IsNeedReconcileSrc = false, IsNeedReconcileDst = false,
        NavLayerCurrent = 0, AutoFitQueue = 0, CannotSkipItemsQueue = 0, SortDirection = ImGuiSortDirection.None,
        SortDirectionsAvailCount = 0, SortDirectionsAvailMask = 0, SortDirectionsAvailList = 0,
    }
end

--- `*dst = *src`
local function TableColumnCopy(dst, src)
    for k, v in pairs(src) do
        if k ~= "ClipRect" then dst[k] = v end
    end
    ImRect_Copy(dst.ClipRect, src.ClipRect)
    return dst
end

local function TableColumnClone(src)
    return TableColumnCopy(ImGuiTableColumn(), src)
end

-- Per-instance data that needs preserving across frames (seemingly most others do not need to be preserved aside from debug needs. Does that means they could be moved to ImGuiTableTempData?)
--- @class ImGuiTableInstanceData
function ImGuiTableInstanceData()
    return { TableInstanceID = 0, LastOuterHeight = 0.0, LastTopHeadersRowHeight = 0.0, LastFrozenHeight = 0.0, HoveredRowLast = -1, HoveredRowNext = -1 }
end

-- Transient data that are only needed between BeginTable() and EndTable(), those buffers are shared (1 per level of stacked table).
-- - Accessing those requires chasing an extra pointer so for very frequently used data we leave them in the main table structure.
-- - We also leave out of this structure data that tend to be particularly useful for debugging/metrics.
-- FIXME-TABLE: more transient data could be stored in a stacked ImGuiTableTempData: e.g. SortSpecs.
--- @class ImGuiTableTempData
function ImGuiTableTempData()
    return {
        WindowID = 0, TableIndex = 0, LastTimeActive = -1.0, AngledHeadersExtraWidth = 0.0,
        AngledHeadersRequests = ImVector(), ReconcileColumnsRequests = ImVector(),
        OldColumnsRawData = nil, OldColumnsData = nil, OldColumnsDataSize = 0,
        UserOuterSize = ImVec2(), DrawSplitter = ImDrawListSplitter(),
        HostBackupWorkRect = ImRect(), HostBackupParentWorkRect = ImRect(),
        HostBackupPrevLineSize = ImVec2(), HostBackupCurrLineSize = ImVec2(), HostBackupCursorMaxPos = ImVec2(),
        HostBackupColumnsOffset = 0.0, HostBackupItemWidth = 0.0, HostBackupItemWidthStackSize = 0,
    }
end

-- Storage for a table
--- @class ImGuiTable
function ImGuiTable()
    return {
        ID = 0, Flags = 0, RawData = nil, TempData = nil,
        Columns = {}, ColumnsSize = 0, DisplayOrderToIndex = {}, RowCellData = {},
        EnabledMaskByDisplayOrder = {}, EnabledMaskByIndex = {}, VisibleMaskByIndex = {},
        SettingsLoadedFlags = 0, SettingsOffset = 0, LastFrameActive = -1, ColumnsCount = 0, CurrentRow = 0, CurrentColumn = 0,
        InstanceCurrent = 0, InstanceInteracted = 0, RowPosY1 = 0.0, RowPosY2 = 0.0, RowMinHeight = 0.0, RowCellPaddingY = 0.0,
        RowTextBaseline = 0.0, RowIndentOffsetX = 0.0, RowFlags = 0, LastRowFlags = 0, RowBgColorCounter = 0,
        RowBgColor = { [0] = 0, [1] = 0 }, BorderColorStrong = 0, BorderColorLight = 0, BorderX1 = 0.0, BorderX2 = 0.0,
        HostIndentX = 0.0, MinColumnWidth = 0.0, OuterPaddingX = 0.0, CellPaddingX = 0.0, CellSpacingX1 = 0.0, CellSpacingX2 = 0.0,
        InnerWidth = 0.0, ColumnsGivenWidth = 0.0, ColumnsAutoFitWidth = 0.0, ColumnsStretchSumWeights = 0.0,
        ResizedColumnNextWidth = 0.0, ResizeLockMinContentsX2 = 0.0, RefScale = 0.0, AngledHeadersHeight = 0.0, AngledHeadersSlope = 0.0,
        OuterRect = ImRect(), InnerRect = ImRect(), WorkRect = ImRect(), InnerClipRect = ImRect(), BgClipRect = ImRect(),
        Bg0ClipRectForDrawCmd = ImRect(), Bg2ClipRectForDrawCmd = ImRect(), HostClipRect = ImRect(), HostBackupInnerClipRect = ImRect(),
        OuterWindow = nil, InnerWindow = nil, ColumnsNames = {}, DrawSplitter = nil,
        InstanceDataFirst = ImGuiTableInstanceData(), InstanceDataExtra = ImVector(),
        SortSpecs = ImGuiTableSortSpecs(), SortSpecsMulti = {}, SortSpecsSingle = ImGuiTableColumnSortSpecs(),
        SortSpecsCount = 0, ColumnsEnabledCount = 0, ColumnsEnabledFixedCount = 0, DeclColumnsCount = 0, AngledHeadersCount = 0,
        HoveredColumnBody = 0, HoveredColumnBorder = 0, HighlightColumnHeader = 0, AutoFitSingleColumn = 0, ResizedColumn = 0,
        LastResizedColumn = 0, HeldHeaderColumn = 0, LastHeldHeaderColumn = 0, ReorderColumn = 0, ReorderColumnDstOrder = 0,
        LeftMostEnabledColumn = 0, RightMostEnabledColumn = 0, LeftMostStretchedColumn = 0, RightMostStretchedColumn = 0,
        ContextPopupColumn = 0, FreezeRowsRequest = 0, FreezeRowsCount = 0, FreezeColumnsRequest = 0, FreezeColumnsCount = 0,
        RowCellDataCurrent = 0, DummyDrawChannel = 0, Bg2DrawChannelCurrent = 0, Bg2DrawChannelUnfrozen = 0, NavLayer = 0,
        IsLayoutLocked = false, IsInsideRow = false, IsNewTable = false, IsInitializing = false, IsReconcileMode = false,
        IsSortSpecsDirty = false, IsUsingHeaders = false, IsContextPopupOpen = false, DisableDefaultContextMenu = false,
        IsSettingsRequestLoad = false, IsSettingsDirty = false, IsDefaultDisplayOrder = false, IsDefaultVisibility = false,
        IsResetAllRequest = false, IsResetDisplayOrderRequest = false, IsResetVisibilityRequest = false, IsUnfrozenRows = false,
        IsDefaultSizingPolicy = false, IsActiveIdAliveBeforeTable = false, IsActiveIdInTable = false,
        HasScrollbarYCurr = false, HasScrollbarYPrev = false, MemoryCompacted = false, HostSkipItems = false,
    }
end

--- @class ImGuiTableColumnSettings
function ImGuiTableColumnSettings()
    return { WidthOrWeight = 0.0, ID = 0, Index = -1, DisplayOrder = -1, SortOrder = -1, SortDirection = ImGuiSortDirection.None,
             IsEnabled = -1, IsStretch = 0, IsLoaded = false }
end

-- Storage for a table .ini settings
--- @class ImGuiTableSettings
function ImGuiTableSettings()
    return { ID = 0, SaveFlags = 0, RefScale = 0.0, ColumnsCount = 0, ColumnsCountMax = 0, LastUsedDate = 0, WantApply = false, Columns = {} }
end

-- Storage data for a single column for legacy Columns() api
--- @class ImGuiOldColumnData
function ImGuiOldColumnData()
    return { OffsetNorm = 0.0, OffsetNormBeforeResize = 0.0, Flags = 0, ClipRect = ImRect() }
end

--- @class ImGuiOldColumns
function ImGuiOldColumns()
    return { ID = 0, Flags = 0, IsFirstFrame = false, IsBeingResized = false, Current = 0, Count = 0, OffMinX = 0.0, OffMaxX = 0.0,
             LineMinY = 0.0, LineMaxY = 0.0, HostCursorPosY = 0.0, HostCursorMaxPosX = 0.0, HostInitialClipRect = ImRect(),
             HostBackupClipRect = ImRect(), HostBackupParentWorkRect = ImRect(), Columns = ImVector(), Splitter = ImDrawListSplitter() }
end

-- Flags for internal's BeginColumns(). This is an obsolete API. Prefer using BeginTable() nowadays!
ImGuiOldColumnFlags = ImGuiOldColumnFlags or {
    None                   = 0,
    NoBorder               = lshift(1, 0), -- Disable column dividers
    NoResize               = lshift(1, 1), -- Disable resizing columns when clicking on the dividers
    NoPreserveWidths       = lshift(1, 2), -- Disable column width preservation when adjusting columns
    NoForceWithinWindow    = lshift(1, 3), -- Disable forcing columns to fit within window
    GrowParentContentsSize = lshift(1, 4), -- Restore pre-1.51 behavior of extending the parent window contents size but _without affecting the columns width at all_. Will eventually remove.
}

ImGuiTableColumnFlags.NoDirectResize_ = ImGuiTableColumnFlags.NoDirectResize_ or lshift(1, 30) -- [Internal] Disable user resizing this column directly (it may however we resized indirectly from its left edge)

local function Rect(r) return ImRect(r.Min.x, r.Min.y, r.Max.x, r.Max.y) end
local function V2(v) return ImVec2(v.x, v.y) end

-------------------------------------------------------------------------------
-- [SECTION] Tables: Main code
-------------------------------------------------------------------------------
-- - TableFixFlags() [Internal]
-- - TableFindByID() [Internal]
-- - BeginTable()
-- - BeginTableEx() [Internal]
-- - TableBeginInitMemory() [Internal]
-- - TableApplyQueuedRequests() [Internal]
-- - TableSetupColumnFlags() [Internal]
-- - TableUpdateLayout() [Internal]
-- - TableUpdateBorders() [Internal]
-- - EndTable()
-- - TableSetupColumn()
-- - TableSetupScrollFreeze()
-------------------------------------------------------------------------------

-- Configuration
local TABLE_DRAW_CHANNEL_BG0 = 0
local TABLE_DRAW_CHANNEL_BG2_FROZEN = 1
local TABLE_DRAW_CHANNEL_NOCLIP = 2                    -- When using ImGuiTableFlags.NoClip (this becomes the last visible channel)
local TABLE_BORDER_SIZE = 1.0                          -- FIXME-TABLE: Currently hard-coded because of clipping assumptions with outer borders rendering.
local TABLE_RESIZE_SEPARATOR_HALF_THICKNESS = 4.0      -- Extend outside inner borders.
local TABLE_RESIZE_SEPARATOR_FEEDBACK_TIMER = 0.06     -- Delay/timer before making the hover feedback (color+cursor) visible because tables/columns tends to be more cramped.

-- Helper
local function TableFixFlags(flags, outer_window)
    -- Adjust flags: set default sizing policy
    if band(flags, ImGuiTableFlags.SizingMask_) == 0 then
        flags = bor(flags, (band(flags, ImGuiTableFlags.ScrollX) ~= 0 or band(outer_window.Flags, ImGuiWindowFlags.AlwaysAutoResize) ~= 0) and ImGuiTableFlags.SizingFixedFit or ImGuiTableFlags.SizingStretchSame)
    end

    -- Adjust flags: enable NoKeepColumnsVisible when using ImGuiTableFlags.SizingFixedSame
    if band(flags, ImGuiTableFlags.SizingMask_) == ImGuiTableFlags.SizingFixedSame then
        flags = bor(flags, ImGuiTableFlags.NoKeepColumnsVisible)
    end

    -- Adjust flags: enforce borders when resizable
    if band(flags, ImGuiTableFlags.Resizable) ~= 0 then
        flags = bor(flags, ImGuiTableFlags.BordersInnerV)
    end

    -- Adjust flags: disable NoHostExtendX/NoHostExtendY if we have any scrolling going on
    if band(flags, bor(ImGuiTableFlags.ScrollX, ImGuiTableFlags.ScrollY)) ~= 0 then
        flags = band(flags, bnot(bor(ImGuiTableFlags.NoHostExtendX, ImGuiTableFlags.NoHostExtendY)))
    end

    -- Adjust flags: NoBordersInBodyUntilResize takes priority over NoBordersInBody
    if band(flags, ImGuiTableFlags.NoBordersInBodyUntilResize) ~= 0 then
        flags = band(flags, bnot(ImGuiTableFlags.NoBordersInBody))
    end

    -- Adjust flags: disable saved settings if there's nothing to save
    if band(flags, bor(ImGuiTableFlags.Resizable, ImGuiTableFlags.Hideable, ImGuiTableFlags.Reorderable, ImGuiTableFlags.Sortable)) == 0 then
        flags = bor(flags, ImGuiTableFlags.NoSavedSettings)
    end

    -- Inherit _NoSavedSettings from top-level window (child windows always have _NoSavedSettings set)
    if band(outer_window.RootWindow.Flags, ImGuiWindowFlags.NoSavedSettings) ~= 0 then
        flags = bor(flags, ImGuiTableFlags.NoSavedSettings)
    end

    return flags
end

function ImGui.TableFindByID(id)
    local g = GImGui
    return g.Tables:GetByKey(id)
end

--- @param table_ ImGuiTable
--- @param instance_no int
function ImGui.TableGetInstanceData(table_, instance_no)
    if instance_no == 0 then
        return table_.InstanceDataFirst
    end
    return table_.InstanceDataExtra.Data[instance_no]
end

function ImGui.TableGetInstanceID(table_, instance_no)
    return ImGui.TableGetInstanceData(table_, instance_no).TableInstanceID
end

-- Read about "TABLE SIZING" at the top of this file.
--- @param str_id        string
--- @param columns_count int
--- @param flags?        ImGuiTableFlags
--- @param outer_size?   ImVec2
--- @param inner_width?  float
function ImGui.BeginTable(str_id, columns_count, flags, outer_size, inner_width)
    local id = ImGui.GetID(str_id)
    return ImGui.BeginTableEx(str_id, id, columns_count, flags, outer_size, inner_width)
end

function ImGui.BeginTableEx(name, id, columns_count, flags, outer_size, inner_width)
    if flags       == nil then flags       = 0                end
    if outer_size  == nil then outer_size  = ImVec2(0.0, 0.0) end
    if inner_width == nil then inner_width = 0.0              end

    local g = GImGui
    local outer_window = ImGui.GetCurrentWindow()
    if outer_window.SkipItems then -- Consistent with other tables + beneficial side effect that assert on miscalling EndTable() will be more visible.
        return false
    end

    -- Sanity checks
    IM_ASSERT(columns_count > 0 and columns_count < IMGUI_TABLE_MAX_COLUMNS)
    if band(flags, ImGuiTableFlags.ScrollX) ~= 0 then
        IM_ASSERT(inner_width >= 0.0)
    end

    -- If an outer size is specified ahead we will be able to early out when not visible. Exact clipping criteria may evolve.
    -- FIXME: coarse clipping because access to table data causes two issues:
    -- - instance numbers varying/unstable. may not be a direct problem for users, but could make outside access broken or confusing, e.g. TestEngine.
    -- - can't implement support for ImGuiChildFlags.ResizeY as we need to somehow pull the height data from somewhere. this also needs stable instance numbers.
    -- The side-effects of accessing table data on coarse clip would be:
    -- - always reserving the pooled ImGuiTable data ahead for a fully clipped table (minor IMHO). Also the 'outer_window_is_measuring_size' criteria may already be defeating this in some situations.
    -- - always performing the GetOrAddByKey() O(log N) query in g.Tables.Map[].
    local use_child_window = band(flags, bor(ImGuiTableFlags.ScrollX, ImGuiTableFlags.ScrollY)) ~= 0
    local avail_size = ImGui.GetContentRegionAvail()
    local actual_outer_size = ImTrunc(ImGui.CalcItemSize(outer_size, mathMax(avail_size.x, IMGUI_WINDOW_HARD_MIN_SIZE), use_child_window and mathMax(avail_size.y, IMGUI_WINDOW_HARD_MIN_SIZE) or 0.0))
    local outer_rect = ImRect(outer_window.DC.CursorPos, outer_window.DC.CursorPos + actual_outer_size)
    local outer_window_is_measuring_size = (outer_window.AutoFitFramesX > 0) or (outer_window.AutoFitFramesY > 0) -- Doesn't apply to AlwaysAutoResize windows!
    if use_child_window and ImGui.IsClippedEx(outer_rect, 0) and not outer_window_is_measuring_size then
        ImGui.ItemSize(outer_rect)
        ImGui.ItemAdd(outer_rect, id)
        g.NextWindowData:ClearFlags()
        return false
    end

    -- Acquire storage for the table
    local table_ = g.Tables:GetOrAddByKey(id)
    if table_.Columns == nil then -- pool created a plain table
        for k, v in pairs(ImGuiTable()) do table_[k] = v end
    end

    -- Acquire temporary buffers
    local table_idx = g.Tables:GetIndex(table_)
    g.TablesTempDataStacked = g.TablesTempDataStacked + 1
    while g.TablesTempDataStacked > g.TablesTempData.Size do
        g.TablesTempData:push_back(ImGuiTableTempData())
    end
    local temp_data = g.TablesTempData.Data[g.TablesTempDataStacked]
    table_.TempData = temp_data
    temp_data.TableIndex = table_idx
    temp_data.ReconcileColumnsRequests:resize(0) -- FIXME: Use shrink(0) everywhere?
    table_.DrawSplitter = table_.TempData.DrawSplitter
    table_.DrawSplitter:Clear()

    -- Fix flags
    table_.IsDefaultSizingPolicy = band(flags, ImGuiTableFlags.SizingMask_) == 0
    flags = TableFixFlags(flags, outer_window)

    -- Initialize
    local previous_frame_active = table_.LastFrameActive
    local instance_no = (previous_frame_active ~= g.FrameCount) and 0 or (table_.InstanceCurrent + 1)
    local previous_flags = table_.Flags
    table_.ID = id
    table_.Flags = flags
    table_.LastFrameActive = g.FrameCount
    table_.OuterWindow = outer_window
    table_.InnerWindow = outer_window
    table_.ColumnsCount = columns_count
    table_.IsLayoutLocked = false
    table_.InnerWidth = inner_width
    table_.NavLayer = outer_window.DC.NavLayerCurrent
    table_.IsNewTable = (previous_frame_active == -1)
    ImVec2_Copy(temp_data.UserOuterSize, outer_size)

    -- Instance data (for instance 0, TableID == TableInstanceID)
    local instance_id
    table_.InstanceCurrent = instance_no
    if instance_no > 0 then
        IM_ASSERT(table_.ColumnsCount == columns_count, "BeginTable(): Cannot change columns count mid-frame while preserving same ID")
        if table_.InstanceDataExtra.Size < instance_no then
            table_.InstanceDataExtra:push_back(ImGuiTableInstanceData())
        end
        instance_id = ImGui.GetIDWithSeed(instance_no, ImGui.GetIDWithSeed("##Instances", nil, id)) -- Push "##Instances" followed by (int)instance_no in ID stack.
    else
        instance_id = id
    end
    local table_instance = ImGui.TableGetInstanceData(table_, table_.InstanceCurrent)
    table_instance.TableInstanceID = instance_id

    -- When not using a child window, WorkRect.Max will grow as we append contents.
    if use_child_window then
        -- Ensure no vertical scrollbar appears if we only want horizontal one, to make flag consistent
        -- (we have no other way to disable vertical scrollbar of a window while keeping the horizontal one showing)
        local override_content_size = ImVec2(FLT_MAX, FLT_MAX)
        if band(flags, ImGuiTableFlags.ScrollX) ~= 0 and band(flags, ImGuiTableFlags.ScrollY) == 0 then
            override_content_size.y = FLT_MIN
        end

        -- Ensure specified width (when not specified, Stretched columns will act as if the width == OuterWidth and
        -- never lead to any scrolling). We don't handle inner_width < 0.0, we could potentially use it to right-align
        -- based on the right side of the child window work rect, which would require knowing ahead if we are going to
        -- have decoration taking horizontal spaces (typically a vertical scrollbar).
        if band(flags, ImGuiTableFlags.ScrollX) ~= 0 and inner_width > 0.0 then
            override_content_size.x = inner_width
        end

        if override_content_size.x ~= FLT_MAX or override_content_size.y ~= FLT_MAX then
            ImGui.SetNextWindowContentSize(ImVec2((override_content_size.x ~= FLT_MAX) and override_content_size.x or 0.0, (override_content_size.y ~= FLT_MAX) and override_content_size.y or 0.0))
        end

        -- Reset scroll if we are reactivating it
        if band(previous_flags, bor(ImGuiTableFlags.ScrollX, ImGuiTableFlags.ScrollY)) == 0 then
            if band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasScroll) == 0 then
                ImGui.SetNextWindowScroll(ImVec2(0.0, 0.0))
            end
        end

        -- Create scrolling region (without border and zero window padding)
        local child_window_flags = (band(flags, ImGuiTableFlags.ScrollX) ~= 0) and ImGuiWindowFlags.HorizontalScrollbar or ImGuiWindowFlags.None
        ImGui.BeginChildEx(name, instance_id, outer_rect:GetSize(), ImGuiChildFlags.None, child_window_flags)
        table_.InnerWindow = g.CurrentWindow
        ImRect_Copy(table_.WorkRect, table_.InnerWindow.WorkRect)
        ImRect_Copy(table_.OuterRect, table_.InnerWindow:Rect())
        ImRect_Copy(table_.InnerRect, table_.InnerWindow.InnerRect)
        IM_ASSERT(table_.InnerWindow.WindowPadding.x == 0.0 and table_.InnerWindow.WindowPadding.y == 0.0 and table_.InnerWindow.WindowBorderSize == 0.0)

        -- Allow submitting when host is measuring
        if table_.InnerWindow.SkipItems and outer_window_is_measuring_size then
            table_.InnerWindow.SkipItems = false
        end

        -- When using multiple instances, ensure they have the same amount of horizontal decorations (aka vertical scrollbar) so stretched columns can be aligned
        if instance_no == 0 then
            table_.HasScrollbarYPrev = table_.HasScrollbarYCurr
            table_.HasScrollbarYCurr = false
        end
        table_.HasScrollbarYCurr = table_.HasScrollbarYCurr or table_.InnerWindow.ScrollbarY
    else
        -- For non-scrolling tables, WorkRect == OuterRect == InnerRect.
        -- But at this point we do NOT have a correct value for .Max.y (unless a height has been explicitly passed in). It will only be updated in EndTable().
        ImRect_Copy(table_.WorkRect, outer_rect)
        ImRect_Copy(table_.OuterRect, outer_rect)
        ImRect_Copy(table_.InnerRect, outer_rect)
        table_.HasScrollbarYPrev = false
        table_.HasScrollbarYCurr = false
        table_.InnerWindow.DC.TreeDepth = table_.InnerWindow.DC.TreeDepth + 1 -- This is designed to always linking ImGuiTreeNodeFlags.DrawLines linking across a table
    end

    -- Push a standardized ID for both child-using and not-child-using tables
    ImGui.PushOverrideID(id)
    if instance_no > 0 then
        ImGui.PushOverrideID(instance_id) -- FIXME: Somehow this is not resolved by stack-tool, even tho GetIDWithSeed() submitted the symbol.
    end

    -- Backup a copy of host window members we will modify
    local inner_window = table_.InnerWindow
    table_.HostIndentX = inner_window.DC.Indent.x
    ImRect_Copy(table_.HostClipRect, inner_window.ClipRect)
    table_.HostSkipItems = inner_window.SkipItems
    temp_data.WindowID = inner_window.ID
    ImRect_Copy(temp_data.HostBackupWorkRect, inner_window.WorkRect)
    ImRect_Copy(temp_data.HostBackupParentWorkRect, inner_window.ParentWorkRect)
    temp_data.HostBackupColumnsOffset = outer_window.DC.ColumnsOffset.x
    ImVec2_Copy(temp_data.HostBackupPrevLineSize, inner_window.DC.PrevLineSize)
    ImVec2_Copy(temp_data.HostBackupCurrLineSize, inner_window.DC.CurrLineSize)
    ImVec2_Copy(temp_data.HostBackupCursorMaxPos, inner_window.DC.CursorMaxPos)
    temp_data.HostBackupItemWidth = outer_window.DC.ItemWidth
    temp_data.HostBackupItemWidthStackSize = outer_window.DC.ItemWidthStack.Size
    inner_window.DC.PrevLineSize.x = 0.0; inner_window.DC.PrevLineSize.y = 0.0
    inner_window.DC.CurrLineSize.x = 0.0; inner_window.DC.CurrLineSize.y = 0.0

    -- Make borders not overlap our contents by offsetting HostClipRect (#6765, #7428, #3752)
    -- (we normally shouldn't alter HostClipRect as we rely on TableMergeDrawChannels() expanding non-clipped column toward the
    -- limits of that rectangle, in order for ImDrawListSplitter::Merge() to merge the draw commands. However since the overlap
    -- problem only affect scrolling tables in this case we can get away with doing it without extra cost).
    if inner_window ~= outer_window then
        -- FIXME: Because inner_window's Scrollbar doesn't know about border size, since it's not encoded in window.WindowBorderSize,
        -- it already overlaps it and doesn't need an extra offset. Ideally we should be able to pass custom border size with
        -- different x/y values to BeginChild().
        local border_size = TABLE_BORDER_SIZE
        if band(flags, ImGuiTableFlags.BordersOuterV) ~= 0 then
            table_.HostClipRect.Min.x = mathMin(table_.HostClipRect.Min.x + border_size, table_.HostClipRect.Max.x)
            if inner_window.DecoOuterSizeX2 == 0.0 then
                table_.HostClipRect.Max.x = mathMax(table_.HostClipRect.Max.x - border_size, table_.HostClipRect.Min.x)
            end
        end
        if band(flags, ImGuiTableFlags.BordersOuterH) ~= 0 then
            table_.HostClipRect.Min.y = mathMin(table_.HostClipRect.Min.y + border_size, table_.HostClipRect.Max.y)
            if inner_window.DecoOuterSizeY2 == 0.0 then
                table_.HostClipRect.Max.y = mathMax(table_.HostClipRect.Max.y - border_size, table_.HostClipRect.Min.y)
            end
        end
    end

    -- Padding and Spacing
    -- - None               ........Content..... Pad .....Content........
    -- - PadOuter           | Pad ..Content..... Pad .....Content.. Pad |
    -- - PadInner           ........Content.. Pad | Pad ..Content........
    -- - PadOuter+PadInner  | Pad ..Content.. Pad | Pad ..Content.. Pad |
    local pad_outer_x
    if band(flags, ImGuiTableFlags.NoPadOuterX) ~= 0 then pad_outer_x = false
    elseif band(flags, ImGuiTableFlags.PadOuterX) ~= 0 then pad_outer_x = true
    else pad_outer_x = band(flags, ImGuiTableFlags.BordersOuterV) ~= 0 end
    local pad_inner_x = band(flags, ImGuiTableFlags.NoPadInnerX) == 0
    local inner_spacing_for_border = (band(flags, ImGuiTableFlags.BordersInnerV) ~= 0) and TABLE_BORDER_SIZE or 0.0
    local inner_spacing_explicit = (pad_inner_x and band(flags, ImGuiTableFlags.BordersInnerV) == 0) and g.Style.CellPadding.x or 0.0
    local inner_padding_explicit = (pad_inner_x and band(flags, ImGuiTableFlags.BordersInnerV) ~= 0) and g.Style.CellPadding.x or 0.0
    table_.CellSpacingX1 = inner_spacing_explicit + inner_spacing_for_border
    table_.CellSpacingX2 = inner_spacing_explicit
    table_.CellPaddingX = inner_padding_explicit

    local outer_padding_for_border = (band(flags, ImGuiTableFlags.BordersOuterV) ~= 0) and TABLE_BORDER_SIZE or 0.0
    local outer_padding_explicit = pad_outer_x and g.Style.CellPadding.x or 0.0
    table_.OuterPaddingX = (outer_padding_for_border + outer_padding_explicit) - table_.CellPaddingX

    table_.CurrentColumn = -1
    table_.CurrentRow = -1
    table_.RowBgColorCounter = 0
    table_.LastRowFlags = ImGuiTableRowFlags.None
    ImRect_Copy(table_.InnerClipRect, (inner_window == outer_window) and table_.WorkRect or inner_window.ClipRect)
    table_.InnerClipRect:ClipWith(table_.WorkRect)     -- We need this to honor inner_width
    table_.InnerClipRect:ClipWithFull(table_.HostClipRect)
    table_.InnerClipRect.Max.y = (band(flags, ImGuiTableFlags.NoHostExtendY) ~= 0) and mathMin(table_.InnerClipRect.Max.y, inner_window.WorkRect.Max.y) or table_.HostClipRect.Max.y

    table_.RowPosY1 = table_.WorkRect.Min.y -- This is needed somehow
    table_.RowPosY2 = table_.WorkRect.Min.y
    table_.RowTextBaseline = 0.0 -- This will be cleared again by TableBeginRow()
    table_.RowCellPaddingY = 0.0
    table_.FreezeRowsRequest = 0; table_.FreezeRowsCount = 0 -- This will be setup by TableSetupScrollFreeze(), if any
    table_.FreezeColumnsRequest = 0; table_.FreezeColumnsCount = 0
    table_.IsUnfrozenRows = true
    table_.DeclColumnsCount = 0; table_.AngledHeadersCount = 0
    if previous_frame_active + 1 < g.FrameCount then
        table_.IsActiveIdInTable = false
    end
    table_.AngledHeadersHeight = 0.0
    temp_data.AngledHeadersExtraWidth = 0.0

    -- Using opaque colors facilitate overlapping lines of the grid, otherwise we'd need to improve TableDrawBorders()
    table_.BorderColorStrong = ImGui.GetColorU32(ImGuiCol.TableBorderStrong)
    table_.BorderColorLight = ImGui.GetColorU32(ImGuiCol.TableBorderLight)

    -- Make table current
    g.CurrentTable = table_
    inner_window.DC.NavIsScrollPushableX = false -- Shortcut for NavUpdateCurrentWindowIsScrollPushableX();
    outer_window.DC.CurrentTableIdx = table_idx
    if inner_window ~= outer_window then -- So EndChild() within the inner window can restore the table properly.
        inner_window.DC.CurrentTableIdx = table_idx
    end

    if band(previous_flags, ImGuiTableFlags.Reorderable) ~= 0 and band(flags, ImGuiTableFlags.Reorderable) == 0 then
        table_.IsResetDisplayOrderRequest = true
    end

    -- Mark as used to avoid GC
    while table_idx >= g.TablesLastTimeActive.Size do
        g.TablesLastTimeActive:push_back(-1.0)
    end
    g.TablesLastTimeActive.Data[table_idx + 1] = g.Time
    temp_data.LastTimeActive = g.Time
    table_.MemoryCompacted = false

    -- Setup memory buffer (clear data if columns count changed)
    local old_columns_count = table_.ColumnsSize
    if old_columns_count ~= 0 and old_columns_count ~= columns_count then
        -- Attempt to preserve width and other settings on column count/specs change (#4046, #9108)
        IMGUI_DEBUG_LOG_TABLE("[table] Table 0x%08X column count %d -> %d, recreating storage.\n", table_.ID, old_columns_count, columns_count)
        IM_ASSERT(temp_data.OldColumnsRawData == nil)
        temp_data.OldColumnsRawData = table_.RawData -- Freed during layout
        temp_data.OldColumnsData = table_.Columns
        temp_data.OldColumnsDataSize = table_.ColumnsSize
        for n = 0, temp_data.OldColumnsDataSize - 1 do
            temp_data.OldColumnsData[n].IsNeedReconcileSrc = true
        end
        table_.RawData = nil
    end
    if table_.RawData == nil then
        ImGui.TableBeginInitMemory(table_, columns_count)
        table_.IsInitializing = true
    end
    if table_.IsResetAllRequest then
        ImGui.TableResetSettings(table_)
    end
    if table_.IsInitializing then
        -- Initialize
        if table_.IsNewTable then
            table_.SettingsOffset = -1
            table_.IsSettingsRequestLoad = true
        end
        table_.IsSortSpecsDirty = true
        table_.IsSettingsDirty = true -- Records itself into .ini file even when in default state (#7934)
        table_.IsReconcileMode = false
        table_.InstanceInteracted = -1
        table_.ContextPopupColumn = -1
        table_.ReorderColumn = -1; table_.ReorderColumnDstOrder = -1; table_.ResizedColumn = -1; table_.LastResizedColumn = -1
        table_.AutoFitSingleColumn = -1
        table_.HoveredColumnBody = -1; table_.HoveredColumnBorder = -1
        for n = 0, columns_count - 1 do
            local column = table_.Columns[n]
            if temp_data.OldColumnsData and n < temp_data.OldColumnsDataSize then
                TableColumnCopy(column, temp_data.OldColumnsData[n])
            else
                local width_auto = column.WidthAuto
                TableColumnCopy(column, ImGuiTableColumn())
                column.WidthAuto = width_auto
                column.IsPreserveWidthAuto = true -- Preserve WidthAuto when reinitializing a live table: not technically necessary but remove a visible flicker
                column.IsEnabled = true; column.IsUserEnabled = true; column.IsUserEnabledNextFrame = true
                column.DisplayOrder = n
            end
            table_.DisplayOrderToIndex[n] = column.DisplayOrder
        end
    end

    -- Load settings
    if table_.IsSettingsRequestLoad then
        ImGui.TableLoadSettings(table_)
    end

    -- Disable output until user calls TableNextRow() or TableNextColumn() leading to the TableUpdateLayout() call..
    -- This is not strictly necessary but will reduce cases were "out of table" output will be misleading to the user.
    -- Because we cannot safely assert in EndTable() when no rows have been created, this seems like our best option.
    inner_window.SkipItems = true

    -- Clear names
    -- At this point the .NameOffset field of each column will be invalid until TableUpdateLayout() or the first call to TableSetupColumn()
    if #table_.ColumnsNames > 0 then
        table.clear(table_.ColumnsNames)
    end

    return true
end

function ImGui.TableBeginInitMemory(table_, columns_count)
    table_.RawData = true
    table_.Columns = {}
    table_.DisplayOrderToIndex = {}
    table_.RowCellData = {}
    for n = 0, columns_count - 1 do
        table_.Columns[n] = ImGuiTableColumn()
        table_.Columns[n].WidthAuto = 0.0
        table_.DisplayOrderToIndex[n] = 0
        table_.RowCellData[n] = { BgColor = 0, Column = 0 }
    end
    table_.ColumnsSize = columns_count
    table_.EnabledMaskByDisplayOrder = {}
    table_.EnabledMaskByIndex = {}
    table_.VisibleMaskByIndex = {}
end

-- Apply queued resizing/reordering/hiding requests
function ImGui.TableApplyQueuedRequests(table_)
    -- Handle resizing request
    -- (We process this in the TableBegin() of the first instance of each table)
    -- FIXME-TABLE: Contains columns if our work area doesn't allow for scrolling?
    if table_.InstanceCurrent == 0 then
        if table_.ResizedColumn ~= -1 and table_.ResizedColumnNextWidth ~= FLT_MAX then
            ImGui.TableSetColumnWidth(table_.ResizedColumn, table_.ResizedColumnNextWidth)
        end
        table_.LastResizedColumn = table_.ResizedColumn
        table_.ResizedColumnNextWidth = FLT_MAX
        table_.ResizedColumn = -1

        -- Process auto-fit for single column, which is a special case for stretch columns and fixed columns with FixedSame policy.
        -- FIXME-TABLE: Would be nice to redistribute available stretch space accordingly to other weights, instead of giving it all to siblings.
        if table_.AutoFitSingleColumn ~= -1 then
            ImGui.TableSetColumnWidth(table_.AutoFitSingleColumn, table_.Columns[table_.AutoFitSingleColumn].WidthAuto)
            table_.AutoFitSingleColumn = -1
        end
    end

    -- Handle reordering request
    -- Note: we don't clear ReorderColumn after handling the request (FIXME: clarify why or add a test).
    if table_.InstanceCurrent == 0 then
        table_.LastHeldHeaderColumn = table_.HeldHeaderColumn
        table_.HeldHeaderColumn = -1
        if table_.ReorderColumn ~= -1 and table_.ReorderColumnDstOrder ~= -1 then
            ImGui.TableSetColumnDisplayOrder(table_, table_.ReorderColumn, table_.ReorderColumnDstOrder)
            table_.ReorderColumnDstOrder = -1
        end

        -- Release
        local g = GImGui
        if g.ActiveId == 0 then -- FIXME: Need to revisit. See 38f5e5a.
            table_.ReorderColumn = -1
        end
        --if (table.HeldHeaderColumn == -1 and table.ReorderColumn ~= -1)
        --    table.ReorderColumn = -1
    end

    -- Handle display order / visibility reset requests
    if table_.IsResetDisplayOrderRequest then
        for n = 0, table_.ColumnsCount - 1 do
            table_.Columns[n].DisplayOrder = n
            table_.DisplayOrderToIndex[n] = n
        end
        table_.IsResetDisplayOrderRequest = false
        table_.IsSettingsDirty = true
    end
    if table_.IsResetVisibilityRequest then
        for n = 0, table_.ColumnsSize - 1 do
            local column = table_.Columns[n]
            local v = band(column.Flags, ImGuiTableColumnFlags.DefaultHide) == 0
            column.IsUserEnabled = v; column.IsUserEnabledNextFrame = v
        end
        table_.IsResetVisibilityRequest = false
        table_.IsSettingsDirty = true
    end
end

-- Apply immediately. See TableQueueSetColumnDisplayOrder() for additional checks/constraints.
function ImGui.TableSetColumnDisplayOrder(table_, column_n, dst_order)
    IM_ASSERT(column_n >= 0 and column_n < table_.ColumnsCount)
    IM_ASSERT(dst_order >= 0 and dst_order < table_.ColumnsCount)

    local src_column = table_.Columns[column_n]
    local src_order = src_column.DisplayOrder
    if src_order == dst_order then
        return
    end
    local reorder_dir = (dst_order < src_order) and -1 or 1

    src_column.DisplayOrder = dst_order
    local order_n = src_order + reorder_dir
    while order_n ~= dst_order + reorder_dir do
        local c = table_.Columns[table_.DisplayOrderToIndex[order_n]]
        c.DisplayOrder = c.DisplayOrder - reorder_dir
        order_n = order_n + reorder_dir
    end
    --IM_ASSERT(dst_column.DisplayOrder == dst_order - reorder_dir)

    -- Display order is stored in both columns.IndexDisplayOrder and table.DisplayOrder[]. Rebuild later from the former.
    -- FIXME-OPT: If this is called multiple times we'd effectively have a O(N^2) thing going on.
    for n = 0, table_.ColumnsCount - 1 do
        table_.DisplayOrderToIndex[table_.Columns[n].DisplayOrder] = n
    end
    table_.IsSettingsDirty = true
end

local function TableGetMaxDisplayOrderAllowed(table_, src_order, dst_order)
    dst_order = ImClamp(dst_order, 0, table_.ColumnsCount - 1)
    if src_order == dst_order then
        return dst_order
    end

    -- Cannot cross over the frozen column limit when interactively reordering.
    -- TableSetupScrollFreeze() enforce a display order range for frozen columns. Reordering across the frozen column barrier is illegal and will be undone.
    if table_.FreezeColumnsRequest > 0 then
        dst_order = (src_order < table_.FreezeColumnsRequest) and ImMin(dst_order, table_.FreezeColumnsRequest - 1) or ImMax(dst_order, table_.FreezeColumnsRequest)
    end

    -- Cannot cross over a column with the ImGuiTableColumnFlags.NoReorder flag.
    local reorder_dir = (src_order < dst_order) and 1 or -1
    local order_n = src_order
    while (src_order < dst_order and order_n <= dst_order) or (dst_order < src_order and order_n >= dst_order) do
        if band(table_.Columns[table_.DisplayOrderToIndex[order_n]].Flags, ImGuiTableColumnFlags.NoReorder) ~= 0 then
            dst_order = (order_n == src_order) and src_order or (order_n - reorder_dir)
            break
        end
        order_n = order_n + reorder_dir
    end
    return dst_order
end

-- Reorder requested by user interaction.
function ImGui.TableQueueSetColumnDisplayOrder(table_, column_n, dst_order)
    local src_order = table_.Columns[column_n].DisplayOrder
    table_.ReorderColumn = column_n
    table_.ReorderColumnDstOrder = -1
    dst_order = TableGetMaxDisplayOrderAllowed(table_, src_order, dst_order)
    if table_.IsLayoutLocked and dst_order == src_order then -- We allow calling the function before layout w/ reconcile so don't early out.
        return
    end
    table_.ReorderColumnDstOrder = dst_order
end

-- Adjust flags: default width mode + stretch columns are not allowed when auto extending
local function TableSetupColumnFlags(table_, column, column_n, flags_in)
    local flags = flags_in

    -- Sizing Policy
    if band(flags, ImGuiTableColumnFlags.WidthMask_) == 0 then
        local table_sizing_policy = band(table_.Flags, ImGuiTableFlags.SizingMask_)
        if table_sizing_policy == ImGuiTableFlags.SizingFixedFit or table_sizing_policy == ImGuiTableFlags.SizingFixedSame then
            flags = bor(flags, ImGuiTableColumnFlags.WidthFixed)
        else
            flags = bor(flags, ImGuiTableColumnFlags.WidthStretch)
        end
    else
        IM_ASSERT(ImIsPowerOfTwo(band(flags, ImGuiTableColumnFlags.WidthMask_))) -- Check that only 1 of each set is used.
    end

    -- Resize
    if band(table_.Flags, ImGuiTableFlags.Resizable) == 0 then
        flags = bor(flags, ImGuiTableColumnFlags.NoResize)
    end

    -- Sorting
    if band(flags, ImGuiTableColumnFlags.NoSortAscending) ~= 0 and band(flags, ImGuiTableColumnFlags.NoSortDescending) ~= 0 then
        flags = bor(flags, ImGuiTableColumnFlags.NoSort)
    end

    -- Indentation
    if band(flags, ImGuiTableColumnFlags.IndentMask_) == 0 then
        flags = bor(flags, (column_n == 0) and ImGuiTableColumnFlags.IndentEnable or ImGuiTableColumnFlags.IndentDisable)
    end

    -- Alignment
    --if (flags & ImGuiTableColumnFlags.AlignMask_) == 0 then
    --    flags = bor(flags, ImGuiTableColumnFlags.AlignCenter)
    --IM_ASSERT(ImIsPowerOfTwo(flags & ImGuiTableColumnFlags.AlignMask_)) -- Check that only 1 of each set is used.

    -- Preserve status flags
    column.Flags = bor(flags, band(column.Flags, ImGuiTableColumnFlags.StatusMask_))

    -- Build an ordered list of available sort directions
    column.SortDirectionsAvailCount = 0; column.SortDirectionsAvailMask = 0; column.SortDirectionsAvailList = 0
    if band(table_.Flags, ImGuiTableFlags.Sortable) ~= 0 then
        local count, mask, list = 0, 0, 0
        local Asc, Desc = ImGuiSortDirection.Ascending, ImGuiSortDirection.Descending
        if band(flags, ImGuiTableColumnFlags.PreferSortAscending) ~= 0 and band(flags, ImGuiTableColumnFlags.NoSortAscending) == 0 then mask = bor(mask, lshift(1, Asc)); list = bor(list, lshift(Asc, lshift(count, 1))); count = count + 1 end
        if band(flags, ImGuiTableColumnFlags.PreferSortDescending) ~= 0 and band(flags, ImGuiTableColumnFlags.NoSortDescending) == 0 then mask = bor(mask, lshift(1, Desc)); list = bor(list, lshift(Desc, lshift(count, 1))); count = count + 1 end
        if band(flags, ImGuiTableColumnFlags.PreferSortAscending) == 0 and band(flags, ImGuiTableColumnFlags.NoSortAscending) == 0 then mask = bor(mask, lshift(1, Asc)); list = bor(list, lshift(Asc, lshift(count, 1))); count = count + 1 end
        if band(flags, ImGuiTableColumnFlags.PreferSortDescending) == 0 and band(flags, ImGuiTableColumnFlags.NoSortDescending) == 0 then mask = bor(mask, lshift(1, Desc)); list = bor(list, lshift(Desc, lshift(count, 1))); count = count + 1 end
        if band(table_.Flags, ImGuiTableFlags.SortTristate) ~= 0 or count == 0 then mask = bor(mask, lshift(1, ImGuiSortDirection.None)); count = count + 1 end
        column.SortDirectionsAvailList = band(list, 0xFF)
        column.SortDirectionsAvailMask = band(mask, 0xFF)
        column.SortDirectionsAvailCount = count
        ImGui.TableFixColumnSortDirection(table_, column)
    end
end

-- Layout columns for the frame. This is in essence the followup to BeginTable() and this is our largest function.
-- Runs on the first call to TableNextRow(), to give a chance for TableSetupColumn() and other TableSetupXXXXX() functions to be called first.
-- FIXME-TABLE: Our width (and therefore our WorkRect) will be minimal in the first frame for _WidthAuto columns.
-- Increase feedback side-effect with widgets relying on WorkRect.Max.x... Maybe provide a default distribution for _WidthAuto columns?
function ImGui.TableUpdateLayout(table_)
    local g = GImGui
    local temp_data = table_.TempData
    IM_ASSERT(table_.IsLayoutLocked == false)
    local columns_count = table_.ColumnsCount

    -- Reconcile moved columns
    if temp_data.ReconcileColumnsRequests.Size > 0 then
        ImGui.TableReconcileColumns(table_)
    end
    if temp_data.OldColumnsRawData then
        temp_data.OldColumnsRawData = nil
        temp_data.OldColumnsData = nil
        temp_data.OldColumnsDataSize = 0
    end

    -- Apply columns settings
    if table_.IsSettingsRequestLoad then
        ImGui.TableLoadSettingsForColumns(table_)
    end
    if table_.IsInitializing or table_.IsSettingsRequestLoad then
        for n = 0, table_.ColumnsSize - 1 do
            local column = table_.Columns[n]
            local init_flags
            if table_.IsSettingsRequestLoad then
                init_flags = column.IsLoadedSettings and bnot(table_.SettingsLoadedFlags) or bnot(0)
            else
                init_flags = column.IsJustCreated and bnot(0) or 0
            end
            ImGui.TableInitColumnDefaults(table_, column, n, init_flags)
        end
        ImGui.TableFixDisplayOrder(table_) -- Call even for non _Reorderable table as we loaded .ini data.
        table_.IsSettingsRequestLoad = false
    end

    -- Apply queued resizing/reordering/hiding requests
    ImGui.TableApplyQueuedRequests(table_)

    -- Handle DPI/font resize
    -- This is designed to facilitate DPI changes with the assumption that e.g. style.CellPadding has been scaled as well.
    -- It will also react to changing fonts with mixed results. It doesn't need to be perfect but merely provide a decent transition.
    -- FIXME-DPI: Provide consistent standards for reference size. Perhaps using g.CurrentDpiScale would be more self explanatory.
    -- This is will lead us to non-rounded WidthRequest in columns, which should work but is a poorly tested path.
    local new_ref_scale_unit = g.FontSize -- g.Font.GetCharAdvance('A') ?
    if table_.RefScale ~= 0.0 and table_.RefScale ~= new_ref_scale_unit then
        local scale_factor = new_ref_scale_unit / table_.RefScale
        for n = 0, columns_count - 1 do
            table_.Columns[n].WidthRequest = table_.Columns[n].WidthRequest * scale_factor
        end
    end
    table_.RefScale = new_ref_scale_unit

    local table_sizing_policy = band(table_.Flags, ImGuiTableFlags.SizingMask_)
    table_.IsDefaultDisplayOrder = true; table_.IsDefaultVisibility = true
    table_.ColumnsEnabledCount = 0
    BitArrayClearAll(table_.EnabledMaskByIndex)
    BitArrayClearAll(table_.EnabledMaskByDisplayOrder)
    table_.LeftMostEnabledColumn = -1
    table_.MinColumnWidth = mathMax(1.0, g.Style.FramePadding.x * 1.0) -- g.Style.ColumnsMinSpacing -- FIXME-TABLE

    -- [Part 1] Apply/lock Enabled and Order states. Calculate auto/ideal width for columns. Count fixed/stretch columns.
    -- Process columns in their visible orders as we are building the Prev/Next indices.
    local count_fixed = 0                -- Number of columns that have fixed sizing policies
    local count_stretch = 0              -- Number of columns that have stretch sizing policies
    local prev_visible_column_idx = -1
    local has_auto_fit_request = false
    local has_resizable = false
    local stretch_sum_width_auto = 0.0
    local fixed_max_width_auto = 0.0
    for order_n = 0, columns_count - 1 do
        local column_n = table_.DisplayOrderToIndex[order_n]
        local column = table_.Columns[column_n]

        -- Clear column setup if not submitted by user. Currently we make it mandatory to call TableSetupColumn() every frame.
        -- It would easily work without but we're not ready to guarantee it since e.g. names need resubmission anyway.
        -- We take a slight shortcut but in theory we could be calling TableSetupColumn() here with dummy values, it should yield the same effect.
        if table_.DeclColumnsCount <= column_n then
            TableSetupColumnFlags(table_, column, column_n, ImGuiTableColumnFlags.None)
            column.NameOffset = -1
            column.ID = 0; column.UserData = 0
            column.InitStretchWeightOrWidth = -1.0
        end

        -- Update Enabled state, mark settings and sort specs dirty
        if band(table_.Flags, ImGuiTableFlags.Hideable) == 0 or band(column.Flags, ImGuiTableColumnFlags.NoHide) ~= 0 then
            column.IsUserEnabledNextFrame = true
        end
        if column.IsUserEnabled ~= column.IsUserEnabledNextFrame then
            column.IsUserEnabled = column.IsUserEnabledNextFrame
            table_.IsSettingsDirty = true
        end
        column.IsEnabled = column.IsUserEnabled and band(column.Flags, ImGuiTableColumnFlags.Disabled) == 0
        column.IsJustCreated = false

        if column.IsEnabled ~= (band(column.Flags, ImGuiTableColumnFlags.DefaultHide) == 0) then
            table_.IsDefaultVisibility = false
        end
        if column_n ~= order_n then
            table_.IsDefaultDisplayOrder = false
        end

        if column.SortOrder ~= -1 and not column.IsEnabled then
            table_.IsSortSpecsDirty = true
        end
        if column.SortOrder > 0 and band(table_.Flags, ImGuiTableFlags.SortMulti) == 0 then
            table_.IsSortSpecsDirty = true
        end

        -- Auto-fit unsized columns
        local start_auto_fit
        if band(column.Flags, ImGuiTableColumnFlags.WidthFixed) ~= 0 then
            start_auto_fit = column.WidthRequest < 0.0
        else
            start_auto_fit = column.StretchWeight < 0.0
        end
        if start_auto_fit then
            column.AutoFitQueue = lshift(1, 3) - 1 -- Fit for three frames
            column.CannotSkipItemsQueue = lshift(1, 3) - 1
        end

        if not column.IsEnabled then
            column.IndexWithinEnabledSet = -1
        else
            -- Mark as enabled and link to previous/next enabled column
            column.PrevEnabledColumn = prev_visible_column_idx
            column.NextEnabledColumn = -1
            if prev_visible_column_idx ~= -1 then
                table_.Columns[prev_visible_column_idx].NextEnabledColumn = column_n
            else
                table_.LeftMostEnabledColumn = column_n
            end
            column.IndexWithinEnabledSet = table_.ColumnsEnabledCount
            table_.ColumnsEnabledCount = table_.ColumnsEnabledCount + 1
            BitArraySet(table_.EnabledMaskByIndex, column_n)
            BitArraySet(table_.EnabledMaskByDisplayOrder, column.DisplayOrder)
            prev_visible_column_idx = column_n
            IM_ASSERT(column.IndexWithinEnabledSet <= column.DisplayOrder)

            -- Calculate ideal/auto column width (that's the width required for all contents to be visible without clipping)
            -- Combine width from regular rows + width from headers unless requested not to.
            if not column.IsPreserveWidthAuto and table_.InstanceCurrent == 0 then
                column.WidthAuto = ImGui.TableGetColumnWidthAuto(table_, column)
            end

            -- Non-resizable columns keep their requested width (apply user value regardless of IsPreserveWidthAuto)
            local column_is_resizable = band(column.Flags, ImGuiTableColumnFlags.NoResize) == 0
            if column_is_resizable then
                has_resizable = true
            end
            if band(column.Flags, ImGuiTableColumnFlags.WidthFixed) ~= 0 and column.InitStretchWeightOrWidth > 0.0 and not column_is_resizable then
                column.WidthAuto = column.InitStretchWeightOrWidth
            end

            if column.AutoFitQueue ~= 0x00 then
                has_auto_fit_request = true
            end
            if band(column.Flags, ImGuiTableColumnFlags.WidthStretch) ~= 0 then
                stretch_sum_width_auto = stretch_sum_width_auto + column.WidthAuto
                count_stretch = count_stretch + 1
            else
                fixed_max_width_auto = mathMax(fixed_max_width_auto, column.WidthAuto)
                count_fixed = count_fixed + 1
            end
        end
    end
    if band(table_.Flags, ImGuiTableFlags.Sortable) ~= 0 and table_.SortSpecsCount == 0 and band(table_.Flags, ImGuiTableFlags.SortTristate) == 0 then
        table_.IsSortSpecsDirty = true
    end
    table_.RightMostEnabledColumn = prev_visible_column_idx
    IM_ASSERT(table_.LeftMostEnabledColumn >= 0 and table_.RightMostEnabledColumn >= 0)

    -- [Part 2] Disable child window clipping while fitting columns. This is not strictly necessary but makes it possible to avoid
    -- the column fitting having to wait until the first visible frame of the child container (may or not be a good thing). Also see #6510.
    -- FIXME-TABLE: for always auto-resizing columns may not want to do that all the time.
    if has_auto_fit_request and table_.OuterWindow ~= table_.InnerWindow then
        table_.InnerWindow.SkipItems = false
    end
    if has_auto_fit_request then
        table_.IsSettingsDirty = true
    end

    -- [Part 3] Fix column flags and record a few extra information.
    local sum_width_requests = 0.0    -- Sum of all width for fixed and auto-resize columns, excluding width contributed by Stretch columns but including spacing/padding.
    local stretch_sum_weights = 0.0   -- Sum of all weights for stretch columns.
    table_.LeftMostStretchedColumn = -1; table_.RightMostStretchedColumn = -1
    for column_n = 0, columns_count - 1 do
        if BitTest(table_.EnabledMaskByIndex, column_n) then
            local column = table_.Columns[column_n]

            local column_is_resizable = band(column.Flags, ImGuiTableColumnFlags.NoResize) == 0
            if band(column.Flags, ImGuiTableColumnFlags.WidthFixed) ~= 0 then
                -- Apply same widths policy
                local width_auto = column.WidthAuto
                if table_sizing_policy == ImGuiTableFlags.SizingFixedSame and (column.AutoFitQueue ~= 0x00 or not column_is_resizable) then
                    width_auto = fixed_max_width_auto
                end

                -- Apply automatic width
                -- Latch initial size for fixed columns and update it constantly for auto-resizing column (unless clipped!)
                if column.AutoFitQueue ~= 0x00 then
                    column.WidthRequest = width_auto
                elseif band(column.Flags, ImGuiTableColumnFlags.WidthFixed) ~= 0 and not column_is_resizable and column.IsRequestOutput then
                    column.WidthRequest = width_auto
                end

                -- FIXME-TABLE: Increase minimum size during init frame to avoid biasing auto-fitting widgets
                -- (e.g. TextWrapped) too much. Otherwise what tends to happen is that TextWrapped would output a very
                -- large height (= first frame scrollbar display very off + clipper would skip lots of items).
                -- This is merely making the side-effect less extreme, but doesn't properly fixes it.
                -- FIXME: Move this to .WidthGiven to avoid temporary lossyness?
                -- FIXME: This break IsPreserveWidthAuto from not flickering if the stored WidthAuto was smaller.
                if column.AutoFitQueue > 0x01 and table_.IsInitializing and not column.IsPreserveWidthAuto then
                    column.WidthRequest = mathMax(column.WidthRequest, table_.MinColumnWidth * 4.0) -- FIXME-TABLE: Another constant/scale?
                end
                sum_width_requests = sum_width_requests + column.WidthRequest
            else
                -- Initialize stretch weight
                if column.AutoFitQueue ~= 0x00 or column.StretchWeight < 0.0 or not column_is_resizable then
                    if column.InitStretchWeightOrWidth > 0.0 then
                        column.StretchWeight = column.InitStretchWeightOrWidth
                    elseif table_sizing_policy == ImGuiTableFlags.SizingStretchProp then
                        column.StretchWeight = (column.WidthAuto / stretch_sum_width_auto) * count_stretch
                    else
                        column.StretchWeight = 1.0
                    end
                end

                stretch_sum_weights = stretch_sum_weights + column.StretchWeight
                if table_.LeftMostStretchedColumn == -1 or table_.Columns[table_.LeftMostStretchedColumn].DisplayOrder > column.DisplayOrder then
                    table_.LeftMostStretchedColumn = column_n
                end
                if table_.RightMostStretchedColumn == -1 or table_.Columns[table_.RightMostStretchedColumn].DisplayOrder < column.DisplayOrder then
                    table_.RightMostStretchedColumn = column_n
                end
            end
            column.IsPreserveWidthAuto = false
            sum_width_requests = sum_width_requests + table_.CellPaddingX * 2.0
        end
    end
    table_.ColumnsEnabledFixedCount = count_fixed
    table_.ColumnsStretchSumWeights = stretch_sum_weights

    -- [Part 4] Apply final widths based on requested widths
    local work_rect = Rect(table_.WorkRect)
    local width_spacings = (table_.OuterPaddingX * 2.0) + (table_.CellSpacingX1 + table_.CellSpacingX2) * (table_.ColumnsEnabledCount - 1)
    local width_removed = (table_.HasScrollbarYPrev and not table_.InnerWindow.ScrollbarY) and g.Style.ScrollbarSize or 0.0 -- To synchronize decoration width of synced tables with mismatching scrollbar state (#5920)
    local width_avail = mathMax(1.0, ((band(table_.Flags, ImGuiTableFlags.ScrollX) ~= 0 and table_.InnerWidth == 0.0) and table_.InnerClipRect:GetWidth() or work_rect:GetWidth()) - width_removed)
    local width_avail_for_stretched_columns = width_avail - width_spacings - sum_width_requests
    local width_remaining_for_stretched_columns = width_avail_for_stretched_columns
    table_.ColumnsGivenWidth = width_spacings + (table_.CellPaddingX * 2.0) * table_.ColumnsEnabledCount
    for column_n = 0, columns_count - 1 do
        if BitTest(table_.EnabledMaskByIndex, column_n) then
            local column = table_.Columns[column_n]

            -- Allocate width for stretched/weighted columns (StretchWeight gets converted into WidthRequest)
            if band(column.Flags, ImGuiTableColumnFlags.WidthStretch) ~= 0 then
                local weight_ratio = column.StretchWeight / stretch_sum_weights
                column.WidthRequest = IM_TRUNC(mathMax(width_avail_for_stretched_columns * weight_ratio, table_.MinColumnWidth) + 0.01)
                width_remaining_for_stretched_columns = width_remaining_for_stretched_columns - column.WidthRequest
            end

            -- [Resize Rule 1] The right-most Visible column is not resizable if there is at least one Stretch column
            -- See additional comments in TableSetColumnWidth().
            if column.NextEnabledColumn == -1 and table_.LeftMostStretchedColumn ~= -1 then
                column.Flags = bor(column.Flags, ImGuiTableColumnFlags.NoDirectResize_)
            end

            -- Assign final width, record width in case we will need to shrink
            column.WidthGiven = ImTrunc(mathMax(column.WidthRequest, table_.MinColumnWidth))
            table_.ColumnsGivenWidth = table_.ColumnsGivenWidth + column.WidthGiven
        end
    end

    -- [Part 5] Redistribute stretch remainder width due to rounding (remainder width is < 1.0 * number of Stretch column).
    -- Using right-to-left distribution (more likely to match resizing cursor).
    if width_remaining_for_stretched_columns >= 1.0 and band(table_.Flags, ImGuiTableFlags.PreciseWidths) == 0 then
        local order_n = columns_count - 1
        while stretch_sum_weights > 0.0 and width_remaining_for_stretched_columns >= 1.0 and order_n >= 0 do
            if BitTest(table_.EnabledMaskByDisplayOrder, order_n) then
                local column = table_.Columns[table_.DisplayOrderToIndex[order_n]]
                if band(column.Flags, ImGuiTableColumnFlags.WidthStretch) ~= 0 then
                    column.WidthRequest = column.WidthRequest + 1.0
                    column.WidthGiven = column.WidthGiven + 1.0
                    width_remaining_for_stretched_columns = width_remaining_for_stretched_columns - 1.0
                end
            end
            order_n = order_n - 1
        end
    end

    -- Determine if table is hovered which will be used to flag columns as hovered.
    -- - In principle we'd like to use the equivalent of IsItemHovered(ImGuiHoveredFlags.AllowWhenBlockedByActiveItem),
    --   but because our item is partially submitted at this point we use ItemHoverable() and a workaround (temporarily
    --   clear ActiveId, which is equivalent to the change provided by _AllowWhenBLockedByActiveItem).
    -- - This allows columns to be marked as hovered when e.g. clicking a button inside the column, or using drag and drop.
    local table_instance = ImGui.TableGetInstanceData(table_, table_.InstanceCurrent)
    table_instance.HoveredRowLast = table_instance.HoveredRowNext
    table_instance.HoveredRowNext = -1
    table_.HoveredColumnBody = -1; table_.HoveredColumnBorder = -1
    local mouse_hit_rect = ImRect(table_.OuterRect.Min.x, table_.OuterRect.Min.y, table_.OuterRect.Max.x, mathMax(table_.OuterRect.Max.y, table_.OuterRect.Min.y + table_instance.LastOuterHeight))
    local backup_active_id = g.ActiveId
    g.ActiveId = 0
    local is_hovering_table = ImGui.ItemHoverable(mouse_hit_rect, 0, ImGuiItemFlags.None)
    g.ActiveId = backup_active_id

    -- Determine skewed MousePos.x to support angled headers.
    local mouse_skewed_x = g.IO.MousePos.x
    if table_.AngledHeadersHeight > 0.0 then
        if g.IO.MousePos.y >= table_.OuterRect.Min.y and g.IO.MousePos.y <= table_.OuterRect.Min.y + table_.AngledHeadersHeight then
            mouse_skewed_x = mouse_skewed_x + ImTrunc((table_.OuterRect.Min.y + table_.AngledHeadersHeight - g.IO.MousePos.y) * table_.AngledHeadersSlope)
        end
    end

    -- [Part 6] Setup final position, offset, skip/clip states and clipping rectangles, detect hovered column
    -- Process columns in their visible orders as we are comparing the visible order and adjusting host_clip_rect while looping.
    local has_at_least_one_column_requesting_output = false
    local offset_x_frozen = (table_.FreezeColumnsCount > 0)
    local offset_x = ((table_.FreezeColumnsCount > 0) and table_.OuterRect.Min.x or work_rect.Min.x) + table_.OuterPaddingX - table_.CellSpacingX1
    local host_clip_rect = Rect(table_.InnerClipRect)
    --host_clip_rect.Max.x += table.CellPaddingX + table.CellSpacingX2
    BitArrayClearAll(table_.VisibleMaskByIndex)
    for order_n = 0, columns_count - 1 do
        local column_n = table_.DisplayOrderToIndex[order_n]
        local column = table_.Columns[column_n]

        -- Initial nav layer: using FreezeRowsCount, NOT FreezeRowsRequest, so Header line changes layer when frozen
        column.NavLayerCurrent = (table_.FreezeRowsCount > 0) and ImGuiNavLayer.Menu or table_.NavLayer

        if offset_x_frozen and table_.FreezeColumnsCount == order_n then
            offset_x = offset_x + work_rect.Min.x - table_.OuterRect.Min.x
            offset_x_frozen = false
        end

        -- Clear status flags
        column.Flags = band(column.Flags, bnot(ImGuiTableColumnFlags.StatusMask_))

        if not BitTest(table_.EnabledMaskByDisplayOrder, order_n) then
            -- Hidden column: clear a few fields and we are done with it for the remainder of the function.
            -- We set a zero-width clip rect but set Min.y/Max.y properly to not interfere with the clipper.
            column.MinX = offset_x; column.MaxX = offset_x; column.WorkMinX = offset_x
            column.ClipRect.Min.x = offset_x; column.ClipRect.Max.x = offset_x
            column.WidthGiven = 0.0
            column.ClipRect.Min.y = work_rect.Min.y
            column.ClipRect.Max.y = FLT_MAX
            column.ClipRect:ClipWithFull(host_clip_rect)
            column.IsVisibleX = false; column.IsVisibleY = false; column.IsRequestOutput = false
            column.IsSkipItems = true
            column.ItemWidth = 1.0
        else
            -- Lock start position
            column.MinX = offset_x

            -- Lock width based on start position and minimum/maximum width for this position
            column.WidthMax = ImGui.TableCalcMaxColumnWidth(table_, column_n)
            column.WidthGiven = mathMin(column.WidthGiven, column.WidthMax)
            column.WidthGiven = mathMax(column.WidthGiven, mathMin(column.WidthRequest, table_.MinColumnWidth))
            column.MaxX = offset_x + column.WidthGiven + table_.CellSpacingX1 + table_.CellSpacingX2 + table_.CellPaddingX * 2.0

            -- Lock other positions
            -- - ClipRect.Min.x: Because merging draw commands doesn't compare min boundaries, we make ClipRect.Min.x match left bounds to be consistent regardless of merging.
            -- - ClipRect.Max.x: using WorkMaxX instead of MaxX (aka including padding) makes things more consistent when resizing down, tho slightly detrimental to visibility in very-small column.
            -- - ClipRect.Max.x: using MaxX makes it easier for header to receive hover highlight with no discontinuity and display sorting arrow.
            -- - FIXME-TABLE: We want equal width columns to have equal (ClipRect.Max.x - WorkMinX) width, which means ClipRect.max.x cannot stray off host_clip_rect.Max.x else right-most column may appear shorter.
            local previous_instance_work_min_x = column.WorkMinX
            column.WorkMinX = column.MinX + table_.CellPaddingX + table_.CellSpacingX1
            column.WorkMaxX = column.MaxX - table_.CellPaddingX - table_.CellSpacingX2 -- Expected max
            column.ItemWidth = ImTrunc(column.WidthGiven * 0.65)
            column.ClipRect.Min.x = column.MinX
            column.ClipRect.Min.y = work_rect.Min.y
            column.ClipRect.Max.x = column.MaxX --column.WorkMaxX
            column.ClipRect.Max.y = FLT_MAX
            column.ClipRect:ClipWithFull(host_clip_rect)

            -- Mark column as Clipped (not in sight)
            -- Note that scrolling tables (where inner_window ~= outer_window) handle Y clipped earlier in BeginTable() so IsVisibleY really only applies to non-scrolling tables.
            -- FIXME-TABLE: Because InnerClipRect.Max.y is conservatively ==outer_window.ClipRect.Max.y, we never can mark columns _Above_ the scroll line as not IsVisibleY.
            -- Taking advantage of LastOuterHeight would yield good results there...
            -- FIXME-TABLE: Y clipping is disabled because it effectively means not submitting will reduce contents width which is fed to outer_window.DC.CursorMaxPos.x,
            -- and this may be used (e.g. typically by outer_window using AlwaysAutoResize or outer_window's horizontal scrollbar, but could be something else).
            -- Possible solution to preserve last known content width for clipped column. Test 'table_reported_size' fails when enabling Y clipping and window is resized small.
            column.IsVisibleX = (column.ClipRect.Max.x > column.ClipRect.Min.x)
            column.IsVisibleY = true -- (column.ClipRect.Max.y > column.ClipRect.Min.y)
            local is_visible = column.IsVisibleX --and column.IsVisibleY
            if is_visible then
                BitArraySet(table_.VisibleMaskByIndex, column_n)
            end

            -- Mark column as requesting output from user. Note that fixed + non-resizable sets are auto-fitting at all times and therefore always request output.
            column.IsRequestOutput = is_visible or column.AutoFitQueue ~= 0 or column.CannotSkipItemsQueue ~= 0

            -- Mark column as SkipItems (ignoring all items/layout)
            -- (table.HostSkipItems is a copy of inner_window.SkipItems before we cleared it above in Part 2)
            column.IsSkipItems = not column.IsEnabled or table_.HostSkipItems
            if column.IsSkipItems then
                IM_ASSERT(not is_visible)
            end
            if column.IsRequestOutput and not column.IsSkipItems then
                has_at_least_one_column_requesting_output = true
            end

            -- Update status flags
            column.Flags = bor(column.Flags, ImGuiTableColumnFlags.IsEnabled)
            if is_visible then
                column.Flags = bor(column.Flags, ImGuiTableColumnFlags.IsVisible)
            end
            if column.SortOrder ~= -1 then
                column.Flags = bor(column.Flags, ImGuiTableColumnFlags.IsSorted)
            end

            -- Detect hovered column
            if is_hovering_table and mouse_skewed_x >= column.ClipRect.Min.x and mouse_skewed_x < column.ClipRect.Max.x then
                column.Flags = bor(column.Flags, ImGuiTableColumnFlags.IsHovered)
                table_.HoveredColumnBody = column_n
            end

            -- Alignment
            -- FIXME-TABLE: This align based on the whole column width, not per-cell, and therefore isn't useful in
            -- many cases (to be able to honor this we might be able to store a log of cells width, per row, for
            -- visible rows, but nav/programmatic scroll would have visible artifacts.)
            --if (column.Flags & ImGuiTableColumnFlags.AlignRight)
            --    column.WorkMinX = ImMax(column.WorkMinX, column.MaxX - column.ContentWidthRowsUnfrozen)
            --else if (column.Flags & ImGuiTableColumnFlags.AlignCenter)
            --    column.WorkMinX = ImLerp(column.WorkMinX, ImMax(column.StartX, column.MaxX - column.ContentWidthRowsUnfrozen), 0.5)

            -- Reset content width variables
            if table_.InstanceCurrent == 0 then
                column.ContentMaxXFrozen = column.WorkMinX
                column.ContentMaxXUnfrozen = column.WorkMinX
                column.ContentMaxXHeadersUsed = column.WorkMinX
                column.ContentMaxXHeadersIdeal = column.WorkMinX
            else
                -- As we store an absolute value to make per-cell updates faster, we need to offset values used for width computation.
                local offset_from_previous_instance = column.WorkMinX - previous_instance_work_min_x
                column.ContentMaxXFrozen = column.ContentMaxXFrozen + offset_from_previous_instance
                column.ContentMaxXUnfrozen = column.ContentMaxXUnfrozen + offset_from_previous_instance
                column.ContentMaxXHeadersUsed = column.ContentMaxXHeadersUsed + offset_from_previous_instance
                column.ContentMaxXHeadersIdeal = column.ContentMaxXHeadersIdeal + offset_from_previous_instance
            end

            -- Don't decrement auto-fit counters until container window got a chance to submit its items
            if table_.HostSkipItems == false and table_.InstanceCurrent == 0 then
                column.AutoFitQueue = rshift(column.AutoFitQueue, 1)
                column.CannotSkipItemsQueue = rshift(column.CannotSkipItemsQueue, 1)
            end

            if order_n < table_.FreezeColumnsCount then
                host_clip_rect.Min.x = ImClamp(column.MaxX + TABLE_BORDER_SIZE, host_clip_rect.Min.x, host_clip_rect.Max.x)
            end

            offset_x = offset_x + column.WidthGiven + table_.CellSpacingX1 + table_.CellSpacingX2 + table_.CellPaddingX * 2.0
        end
    end

    -- In case the table is visible (e.g. decorations) but all columns clipped, we keep a column visible.
    -- Else if give no chance to a clipper-savvy user to submit rows and therefore total contents height used by scrollbar.
    if has_at_least_one_column_requesting_output == false then
        table_.Columns[table_.LeftMostEnabledColumn].IsRequestOutput = true
        table_.Columns[table_.LeftMostEnabledColumn].IsSkipItems = false
    end

    -- [Part 7] Detect/store when we are hovering the unused space after the right-most column (so e.g. context menus can react on it)
    -- Clear Resizable flag if none of our column are actually resizable (either via an explicit _NoResize flag, either
    -- because of using _WidthAuto/_WidthStretch). This will hide the resizing option from the context menu.
    local unused_x1 = mathMax(table_.WorkRect.Min.x, table_.Columns[table_.RightMostEnabledColumn].ClipRect.Max.x)
    if is_hovering_table and table_.HoveredColumnBody == -1 then
        if mouse_skewed_x >= unused_x1 then
            table_.HoveredColumnBody = columns_count
        end
    end
    if has_resizable == false and band(table_.Flags, ImGuiTableFlags.Resizable) ~= 0 then
        table_.Flags = band(table_.Flags, bnot(ImGuiTableFlags.Resizable))
    end

    table_.IsActiveIdAliveBeforeTable = (g.ActiveIdIsAlive ~= 0)

    -- [Part 8] Lock actual OuterRect/WorkRect right-most position.
    -- This is done late to handle the case of fixed-columns tables not claiming more widths that they need.
    -- Because of this we are careful with uses of WorkRect and InnerClipRect before this point.
    if table_.RightMostStretchedColumn ~= -1 then
        table_.Flags = band(table_.Flags, bnot(ImGuiTableFlags.NoHostExtendX))
    end
    if band(table_.Flags, ImGuiTableFlags.NoHostExtendX) ~= 0 then
        table_.OuterRect.Max.x = unused_x1; table_.WorkRect.Max.x = unused_x1
        table_.InnerClipRect.Max.x = mathMin(table_.InnerClipRect.Max.x, unused_x1)
    end
    ImRect_Copy(table_.InnerWindow.ParentWorkRect, table_.WorkRect)
    table_.BorderX1 = table_.InnerClipRect.Min.x
    table_.BorderX2 = table_.InnerClipRect.Max.x

    -- Setup window's WorkRect.Max.y for GetContentRegionAvail(). Other values will be updated in each TableBeginCell() call.
    local window_content_max_y
    if band(table_.Flags, ImGuiTableFlags.NoHostExtendY) ~= 0 then
        window_content_max_y = table_.OuterRect.Max.y
    else
        window_content_max_y = mathMax(table_.InnerWindow.ContentRegionRect.Max.y, (band(table_.Flags, ImGuiTableFlags.ScrollY) ~= 0) and 0.0 or table_.OuterRect.Max.y)
    end
    table_.InnerWindow.WorkRect.Max.y = ImClamp(window_content_max_y - g.Style.CellPadding.y, table_.InnerWindow.WorkRect.Min.y, table_.InnerWindow.WorkRect.Max.y)

    -- [Part 9] Allocate draw channels and setup background cliprect
    ImGui.TableSetupDrawChannels(table_)

    -- [Part 10] Hit testing on borders
    if band(table_.Flags, ImGuiTableFlags.Resizable) ~= 0 then
        ImGui.TableUpdateBorders(table_)
    end
    table_instance.LastTopHeadersRowHeight = 0.0
    table_.IsLayoutLocked = true
    table_.IsUsingHeaders = false

    -- Highlight header
    table_.HighlightColumnHeader = -1
    if table_.IsContextPopupOpen and table_.ContextPopupColumn ~= -1 and table_.InstanceInteracted == table_.InstanceCurrent then
        table_.HighlightColumnHeader = table_.ContextPopupColumn
    elseif band(table_.Flags, ImGuiTableFlags.HighlightHoveredColumn) ~= 0 and table_.HoveredColumnBody ~= -1 and table_.HoveredColumnBody ~= columns_count and table_.HoveredColumnBorder == -1 then
        if g.ActiveId == 0 or (table_.IsActiveIdInTable or g.DragDropActive) then
            table_.HighlightColumnHeader = table_.HoveredColumnBody
        end
    end

    -- [Part 11] Default context menu
    -- - To append to this menu: you can call TableBeginContextMenuPopup()/.../EndPopup().
    -- - To modify or replace this: set table.DisableDefaultContextMenu = true, then call TableBeginContextMenuPopup()/.../EndPopup().
    -- - You may call TableDrawDefaultContextMenu() with selected flags to display specific sections of the default menu,
    --   e.g. TableDrawDefaultContextMenu(table, table.Flags & ~ImGuiTableFlags.Hideable) will display everything EXCEPT columns visibility options.
    if table_.DisableDefaultContextMenu == false and ImGui.TableBeginContextMenuPopup(table_) then
        ImGui.TableDrawDefaultContextMenu(table_, table_.Flags)
        ImGui.EndPopup()
    end

    -- [Part 12] Sanitize and build sort specs before we have a chance to use them for display.
    -- This path will only be exercised when sort specs are modified before header rows (e.g. init or visibility change)
    if table_.IsSortSpecsDirty and band(table_.Flags, ImGuiTableFlags.Sortable) ~= 0 then
        ImGui.TableSortSpecsBuild(table_)
    end

    -- [Part 13] Setup inner window decoration size (for scrolling / nav tracking to properly take account of frozen rows/columns)
    if table_.FreezeColumnsRequest > 0 then
        table_.InnerWindow.DecoInnerSizeX1 = table_.Columns[table_.DisplayOrderToIndex[table_.FreezeColumnsRequest - 1]].MaxX - table_.OuterRect.Min.x -- FIXME-FROZEN
    end
    if table_.FreezeRowsRequest > 0 then
        table_.InnerWindow.DecoInnerSizeY1 = table_instance.LastFrozenHeight
    end
    table_instance.LastFrozenHeight = 0.0

    local inner_window = table_.InnerWindow
    local bs = g.BoxSelectState
    if bs and bs.Window == inner_window and bs.UnclipMode then
        ImGui.TableApplyExternalUnclipRect(table_, bs.UnclipRect)
    end

    -- Initial state
    if band(table_.Flags, ImGuiTableFlags.NoClip) ~= 0 then
        table_.DrawSplitter:SetCurrentChannel(inner_window.DrawList, TABLE_DRAW_CHANNEL_NOCLIP)
    else
        inner_window.DrawList:PushClipRect(inner_window.InnerClipRect.Min, inner_window.InnerClipRect.Max, false) -- FIXME: use table.InnerClipRect?
    end
end

-- When starting a BeginMultiSelect() after table has been layout we update IsRequestOutput fields.
function ImGui.TableApplyExternalUnclipRect(table_, rect)
    if rect:IsInverted() then
        return
    end
    for column_n = 0, table_.ColumnsCount - 1 do
        local column = table_.Columns[column_n]
        if not column.IsRequestOutput then
            if rect:Overlaps(ImRect(column.MinX, table_.WorkRect.Min.y, column.MaxX, FLT_MAX)) then
                column.IsRequestOutput = true
            end
        end
    end
end

-- Process hit-testing on resizing borders. Actual size change will be applied in EndTable()
-- - Set table.HoveredColumnBorder with a short delay/timer to reduce visual feedback noise.
function ImGui.TableUpdateBorders(table_)
    local g = GImGui
    IM_ASSERT(band(table_.Flags, ImGuiTableFlags.Resizable) ~= 0)

    -- At this point OuterRect height may be zero or under actual final height, so we rely on temporal coherency and
    -- use the final height from last frame. Because this is only affecting _interaction_ with columns, it is not
    -- really problematic (whereas the actual visual will be displayed in EndTable() and using the current frame height).
    -- Actual columns highlight/render will be performed in EndTable() and not be affected.
    local table_instance = ImGui.TableGetInstanceData(table_, table_.InstanceCurrent)
    local hit_half_width = ImTrunc(TABLE_RESIZE_SEPARATOR_HALF_THICKNESS * g.CurrentDpiScale)
    local hit_y1 = ((table_.FreezeRowsCount >= 1) and table_.OuterRect.Min.y or table_.WorkRect.Min.y) + table_.AngledHeadersHeight
    local hit_y2_body = mathMax(table_.OuterRect.Max.y, hit_y1 + table_instance.LastOuterHeight - table_.AngledHeadersHeight)
    local hit_y2_head = hit_y1 + table_instance.LastTopHeadersRowHeight

    for order_n = 0, table_.ColumnsCount - 1 do
        repeat
            if not BitTest(table_.EnabledMaskByDisplayOrder, order_n) then
                break
            end

            local column_n = table_.DisplayOrderToIndex[order_n]
            local column = table_.Columns[column_n]
            if band(column.Flags, bor(ImGuiTableColumnFlags.NoResize, ImGuiTableColumnFlags.NoDirectResize_)) ~= 0 then
                break
            end

            -- ImGuiTableFlags.NoBordersInBodyUntilResize will be honored in TableDrawBorders()
            local border_y2_hit = (band(table_.Flags, ImGuiTableFlags.NoBordersInBody) ~= 0) and hit_y2_head or hit_y2_body
            if band(table_.Flags, ImGuiTableFlags.NoBordersInBody) ~= 0 and table_.IsUsingHeaders == false then
                break
            end

            if not column.IsVisibleX and table_.LastResizedColumn ~= column_n then
                break
            end

            local column_id = ImGui.TableGetColumnResizeID(table_, column_n, table_.InstanceCurrent)
            local hit_rect = ImRect(column.MaxX - hit_half_width, hit_y1, column.MaxX + hit_half_width, border_y2_hit)
            ImGui.ItemAdd(hit_rect, column_id, nil, ImGuiItemFlags.NoNav)
            --ImGui.GetForegroundDrawList():AddRect(hit_rect.Min, hit_rect.Max, IM_COL32(255, 0, 0, 100))

            local pressed, hovered, held = ImGui.ButtonBehavior(hit_rect, column_id, bor(ImGuiButtonFlags.FlattenChildren, ImGuiButtonFlags.PressedOnClick, ImGuiButtonFlags.PressedOnDoubleClick, ImGuiButtonFlags.NoNavFocus))
            if pressed and ImGui.IsMouseDoubleClicked(0) then
                ImGui.TableSetColumnWidthAutoSingle(table_, column_n)
                ImGui.ClearActiveID()
                held = false
            end
            if held then
                if table_.LastResizedColumn == -1 then
                    table_.ResizeLockMinContentsX2 = (table_.RightMostEnabledColumn ~= -1) and table_.Columns[table_.RightMostEnabledColumn].MaxX or -FLT_MAX
                end
                table_.ResizedColumn = column_n
                table_.InstanceInteracted = table_.InstanceCurrent
            end
            if (hovered and g.HoveredIdTimer > TABLE_RESIZE_SEPARATOR_FEEDBACK_TIMER) or held then
                table_.HoveredColumnBorder = column_n
                ImGui.SetMouseCursor(ImGuiMouseCursor.ResizeEW)
            end
        until true
    end
end

function ImGui.EndTable()
    local g = GImGui
    local table_ = g.CurrentTable
    IM_ASSERT_USER_ERROR_RET(table_ ~= nil, "EndTable() call should only be done while in BeginTable() scope!")

    -- This assert would be very useful to catch a common error... unfortunately it would probably trigger in some
    -- cases, and for consistency user may sometimes output empty tables (and still benefit from e.g. outer border)
    --IM_ASSERT(table.IsLayoutLocked, "Table unused: never called TableNextRow(), is that the intent?")

    -- If the user never got to call TableNextRow() or TableNextColumn(), we call layout ourselves to ensure all our
    -- code paths are consistent (instead of just hoping that TableBegin/TableEnd will work), get borders drawn, etc.
    if not table_.IsLayoutLocked then
        ImGui.TableUpdateLayout(table_)
    end

    local flags = table_.Flags
    local inner_window = table_.InnerWindow
    local outer_window = table_.OuterWindow
    local temp_data = table_.TempData
    IM_ASSERT(inner_window == g.CurrentWindow and inner_window.ID == temp_data.WindowID)
    IM_ASSERT(outer_window == inner_window or outer_window == inner_window.ParentWindow)

    if table_.IsInsideRow then
        ImGui.TableEndRow(table_)
    end

    -- Context menu in columns body
    if band(flags, ImGuiTableFlags.ContextMenuInBody) ~= 0 then
        if table_.HoveredColumnBody ~= -1 and not ImGui.IsAnyItemHovered() and ImGui.IsMouseReleased(ImGuiMouseButton.Right) then
            ImGui.TableOpenContextMenu(table_.HoveredColumnBody)
        end
    end

    -- Finalize table height
    local table_instance = ImGui.TableGetInstanceData(table_, table_.InstanceCurrent)
    ImVec2_Copy(inner_window.DC.PrevLineSize, temp_data.HostBackupPrevLineSize)
    ImVec2_Copy(inner_window.DC.CurrLineSize, temp_data.HostBackupCurrLineSize)
    ImVec2_Copy(inner_window.DC.CursorMaxPos, temp_data.HostBackupCursorMaxPos)
    local inner_content_max_y = ImCeil(table_.RowPosY2) -- Rounding final position is important as we currently don't round row height ('Demo->Tables->Outer Size' demo uses non-integer heights)
    IM_ASSERT(table_.RowPosY2 == inner_window.DC.CursorPos.y)
    if inner_window ~= outer_window then
        inner_window.DC.CursorMaxPos.y = inner_content_max_y
    elseif band(flags, ImGuiTableFlags.NoHostExtendY) == 0 then
        local v = mathMax(table_.OuterRect.Max.y, inner_content_max_y) -- Patch OuterRect/InnerRect height
        table_.OuterRect.Max.y = v; table_.InnerRect.Max.y = v
    end
    table_.WorkRect.Max.y = mathMax(table_.WorkRect.Max.y, table_.OuterRect.Max.y)
    table_instance.LastOuterHeight = table_.OuterRect:GetHeight()

    -- Setup inner scrolling range
    -- FIXME: This ideally should be done earlier, in BeginTable() SetNextWindowContentSize call, just like writing to inner_window.DC.CursorMaxPos.y,
    -- but since the later is likely to be impossible to do we'd rather update both axes together.
    if band(table_.Flags, ImGuiTableFlags.ScrollX) ~= 0 then
        local outer_padding_for_border = (band(table_.Flags, ImGuiTableFlags.BordersOuterV) ~= 0) and TABLE_BORDER_SIZE or 0.0
        local max_pos_x = inner_window.DC.CursorMaxPos.x
        if table_.RightMostEnabledColumn ~= -1 then
            max_pos_x = mathMax(max_pos_x, table_.Columns[table_.RightMostEnabledColumn].WorkMaxX + table_.CellPaddingX + table_.OuterPaddingX - outer_padding_for_border)
        end
        if table_.ResizedColumn ~= -1 then
            max_pos_x = mathMax(max_pos_x, table_.ResizeLockMinContentsX2)
        end
        inner_window.DC.CursorMaxPos.x = max_pos_x + table_.TempData.AngledHeadersExtraWidth
    end

    -- Pop clipping rect
    if band(flags, ImGuiTableFlags.NoClip) == 0 then
        inner_window.DrawList:PopClipRect()
    end
    ImRect_CopyFromV4(inner_window.ClipRect, inner_window.DrawList._ClipRectStack:back())

    -- Draw borders
    if band(flags, ImGuiTableFlags.Borders) ~= 0 then
        ImGui.TableDrawBorders(table_)
    end

    -- Flatten channels and merge draw calls
    local splitter = table_.DrawSplitter
    splitter:SetCurrentChannel(inner_window.DrawList, 0)
    if band(table_.Flags, ImGuiTableFlags.NoClip) == 0 then
        ImGui.TableMergeDrawChannels(table_)
    end
    splitter:Merge(inner_window.DrawList)

    -- Update ColumnsAutoFitWidth to get us ahead for host using our size to auto-resize without waiting for next BeginTable()
    local auto_fit_width_for_fixed = 0.0
    local auto_fit_width_for_stretched = 0.0
    local auto_fit_width_for_stretched_min = 0.0
    for column_n = 0, table_.ColumnsCount - 1 do
        if BitTest(table_.EnabledMaskByIndex, column_n) then
            local column = table_.Columns[column_n]
            local column_width_request
            if band(column.Flags, ImGuiTableColumnFlags.WidthFixed) ~= 0 and band(column.Flags, ImGuiTableColumnFlags.NoResize) == 0 then
                column_width_request = column.WidthRequest
            else
                column_width_request = ImGui.TableGetColumnWidthAuto(table_, column)
            end
            if band(column.Flags, ImGuiTableColumnFlags.WidthFixed) ~= 0 then
                auto_fit_width_for_fixed = auto_fit_width_for_fixed + column_width_request
            else
                auto_fit_width_for_stretched = auto_fit_width_for_stretched + column_width_request
            end
            if band(column.Flags, ImGuiTableColumnFlags.WidthStretch) ~= 0 and band(column.Flags, ImGuiTableColumnFlags.NoResize) ~= 0 then
                auto_fit_width_for_stretched_min = mathMax(auto_fit_width_for_stretched_min, column_width_request / (column.StretchWeight / table_.ColumnsStretchSumWeights))
            end
        end
    end
    local width_spacings = (table_.OuterPaddingX * 2.0) + (table_.CellSpacingX1 + table_.CellSpacingX2) * (table_.ColumnsEnabledCount - 1)
    table_.ColumnsAutoFitWidth = width_spacings + (table_.CellPaddingX * 2.0) * table_.ColumnsEnabledCount + auto_fit_width_for_fixed + mathMax(auto_fit_width_for_stretched, auto_fit_width_for_stretched_min)

    -- Update scroll
    if band(table_.Flags, ImGuiTableFlags.ScrollX) == 0 and inner_window ~= outer_window then
        inner_window.Scroll.x = 0.0
    elseif table_.LastResizedColumn ~= -1 and table_.ResizedColumn == -1 and inner_window.ScrollbarX and table_.InstanceInteracted == table_.InstanceCurrent then
        -- When releasing a column being resized, scroll to keep the resulting column in sight
        local neighbor_width_to_keep_visible = table_.MinColumnWidth + table_.CellPaddingX * 2.0
        local column = table_.Columns[table_.LastResizedColumn]
        if column.MaxX < table_.InnerClipRect.Min.x then
            ImGui.SetScrollFromPosX(inner_window, column.MaxX - inner_window.Pos.x - neighbor_width_to_keep_visible, 1.0)
        elseif column.MaxX > table_.InnerClipRect.Max.x then
            ImGui.SetScrollFromPosX(inner_window, column.MaxX - inner_window.Pos.x + neighbor_width_to_keep_visible, 1.0)
        end
    end

    -- Apply resizing/dragging at the end of the frame
    if table_.ResizedColumn ~= -1 and table_.InstanceCurrent == table_.InstanceInteracted then
        local column = table_.Columns[table_.ResizedColumn]
        local new_x2 = (g.IO.MousePos.x - g.ActiveIdClickOffset.x + ImTrunc(TABLE_RESIZE_SEPARATOR_HALF_THICKNESS * g.CurrentDpiScale))
        local new_width = ImTrunc(new_x2 - column.MinX - table_.CellSpacingX1 - table_.CellPaddingX * 2.0)
        table_.ResizedColumnNextWidth = new_width
    end

    table_.IsActiveIdInTable = (g.ActiveIdIsAlive ~= 0 and table_.IsActiveIdAliveBeforeTable == false)

    -- Pop from id stack
    IM_ASSERT_USER_ERROR(inner_window.IDStack:back() == table_instance.TableInstanceID, "Mismatching PushID/PopID!")
    IM_ASSERT_USER_ERROR(outer_window.DC.ItemWidthStack.Size >= temp_data.HostBackupItemWidthStackSize, "Too many PopItemWidth!")
    if table_.InstanceCurrent > 0 then
        ImGui.PopID()
    end
    ImGui.PopID()

    -- Restore window data that we modified
    local backup_outer_max_pos = V2(outer_window.DC.CursorMaxPos)
    ImRect_Copy(inner_window.WorkRect, temp_data.HostBackupWorkRect)
    ImRect_Copy(inner_window.ParentWorkRect, temp_data.HostBackupParentWorkRect)
    inner_window.SkipItems = table_.HostSkipItems
    ImVec2_Copy(outer_window.DC.CursorPos, table_.OuterRect.Min)
    outer_window.DC.ItemWidth = temp_data.HostBackupItemWidth
    outer_window.DC.ItemWidthStack:resize(temp_data.HostBackupItemWidthStackSize)
    outer_window.DC.ColumnsOffset.x = temp_data.HostBackupColumnsOffset

    -- Layout in outer window
    -- (FIXME: To allow auto-fit and allow desirable effect of SameLine() we dissociate 'used' vs 'ideal' size by overriding
    -- CursorPosPrevLine and CursorMaxPos manually. That should be a more general layout feature, see same problem e.g. #3414)
    if inner_window ~= outer_window then
        local backup_nav_layers_active_mask = inner_window.DC.NavLayersActiveMask
        inner_window.DC.NavLayersActiveMask = bor(inner_window.DC.NavLayersActiveMask, lshift(1, table_.NavLayer)) -- So empty table don't appear to navigate differently.
        g.CurrentTable = nil -- To avoid error recovery recursing
        ImGui.EndChild()
        g.CurrentTable = table_
        inner_window.DC.NavLayersActiveMask = backup_nav_layers_active_mask
    else
        inner_window.DC.TreeDepth = inner_window.DC.TreeDepth - 1
        ImGui.ItemSize(table_.OuterRect:GetSize())
        ImGui.ItemAdd(table_.OuterRect, 0)
    end

    -- Override declared contents width/height to enable auto-resize while not needlessly adding a scrollbar
    if band(table_.Flags, ImGuiTableFlags.NoHostExtendX) ~= 0 then
        -- FIXME-TABLE: Could we remove this section?
        -- ColumnsAutoFitWidth may be one frame ahead here since for Fixed+NoResize is calculated from latest contents
        IM_ASSERT(band(table_.Flags, ImGuiTableFlags.ScrollX) == 0)
        outer_window.DC.CursorMaxPos.x = mathMax(backup_outer_max_pos.x, table_.OuterRect.Min.x + table_.ColumnsAutoFitWidth)
    elseif temp_data.UserOuterSize.x <= 0.0 then
        -- Some references for this: #7651 + tests "table_reported_size", "table_reported_size_outer" equivalent Y block, #9352
        -- - FIXME-TABLE: Would make sense to pre-compute expected scrollbar visibility/sizes to generally save a frame of feedback? See broken test in 'table_reported_size_outer'
        local outer_content_max_x = table_.OuterRect.Min.x + table_.ColumnsAutoFitWidth
        local decoration_size = table_.TempData.AngledHeadersExtraWidth + ((inner_window ~= outer_window) and inner_window.ScrollbarSizes.x or 0.0)
        outer_window.DC.IdealMaxPos.x = mathMax(outer_window.DC.IdealMaxPos.x, outer_content_max_x + decoration_size - temp_data.UserOuterSize.x)
        outer_window.DC.CursorMaxPos.x = mathMax(backup_outer_max_pos.x, mathMin(table_.OuterRect.Max.x, outer_content_max_x + decoration_size))
    else
        outer_window.DC.CursorMaxPos.x = mathMax(backup_outer_max_pos.x, table_.OuterRect.Max.x)
    end
    if temp_data.UserOuterSize.y <= 0.0 then
        -- (same comment as above)
        local outer_content_size_y = (inner_window == outer_window) and (inner_content_max_y - table_.InnerRect.Min.y) or (inner_content_max_y - inner_window.DC.CursorStartPos.y)
        local outer_content_max_y = table_.OuterRect.Min.y + outer_content_size_y
        local decoration_size = (inner_window ~= outer_window) and inner_window.ScrollbarSizes.y or 0.0
        outer_window.DC.IdealMaxPos.y = mathMax(outer_window.DC.IdealMaxPos.y, outer_content_max_y + decoration_size - temp_data.UserOuterSize.y)
        outer_window.DC.CursorMaxPos.y = mathMax(backup_outer_max_pos.y, mathMin(table_.OuterRect.Max.y, outer_content_max_y + decoration_size))
    else
        -- OuterRect.Max.y may already have been pushed downward from the initial value (unless ImGuiTableFlags.NoHostExtendY is set)
        outer_window.DC.CursorMaxPos.y = mathMax(backup_outer_max_pos.y, table_.OuterRect.Max.y)
    end

    -- Save settings
    if table_.IsSettingsDirty then
        ImGui.TableSaveSettings(table_)
    end
    table_.IsInitializing = false

    -- Clear or restore current table, if any
    IM_ASSERT(g.CurrentWindow == outer_window and g.CurrentTable == table_)
    IM_ASSERT(g.TablesTempDataStacked > 0)
    g.TablesTempDataStacked = g.TablesTempDataStacked - 1
    temp_data = (g.TablesTempDataStacked > 0) and g.TablesTempData.Data[g.TablesTempDataStacked] or nil
    g.CurrentTable = (temp_data and (temp_data.WindowID == outer_window.ID)) and g.Tables:GetByIndex(temp_data.TableIndex) or nil
    if g.CurrentTable then
        g.CurrentTable.TempData = temp_data
        g.CurrentTable.DrawSplitter = temp_data.DrawSplitter
    end
    outer_window.DC.CurrentTableIdx = g.CurrentTable and g.Tables:GetIndex(g.CurrentTable) or -1
    ImGui.NavUpdateCurrentWindowIsScrollPushableX()
end

-- Called in TableUpdateLayout() when initializing/after loading settings.
-- 'init_mask' specify which fields to initialize.
--- @param column_n int # index of `column` (C++: Columns.index_from_ptr(column))
function ImGui.TableInitColumnDefaults(table_, column, column_n, init_mask)
    local flags = column.Flags
    if band(init_mask, ImGuiTableFlags.Resizable) ~= 0 then
        local init_width_or_weight = column.InitStretchWeightOrWidth
        column.WidthRequest = (band(flags, ImGuiTableColumnFlags.WidthFixed) ~= 0 and init_width_or_weight > 0.0) and init_width_or_weight or -1.0
        column.StretchWeight = (init_width_or_weight > 0.0 and band(flags, ImGuiTableColumnFlags.WidthStretch) ~= 0) and init_width_or_weight or -1.0
        if init_width_or_weight > 0.0 then -- Disable auto-fit if an explicit width/weight has been specified
            column.AutoFitQueue = 0x00
        end
    end
    if band(init_mask, ImGuiTableFlags.Reorderable) ~= 0 then
        column.DisplayOrder = (band(table_.Flags, ImGuiTableFlags.Reorderable) ~= 0) and -1 or column_n
    end
    if band(init_mask, ImGuiTableFlags.Hideable) ~= 0 then
        local v = band(flags, ImGuiTableColumnFlags.DefaultHide) == 0
        column.IsUserEnabled = v; column.IsUserEnabledNextFrame = v
    end
    if band(init_mask, ImGuiTableFlags.Sortable) ~= 0 then
        -- Multiple columns using _DefaultSort will be reassigned unique SortOrder values when building the sort specs.
        column.SortOrder = (band(flags, ImGuiTableColumnFlags.DefaultSort) ~= 0) and 0 or -1
        if band(flags, ImGuiTableColumnFlags.DefaultSort) ~= 0 then
            column.SortDirection = (band(flags, ImGuiTableColumnFlags.PreferSortDescending) ~= 0) and ImGuiSortDirection.Descending or ImGuiSortDirection.Ascending
        else
            column.SortDirection = ImGuiSortDirection.None
        end
    end
end

-- See "COLUMNS SIZING POLICIES" comments at the top of this file
-- If (init_width_or_weight <= 0.0) it is ignored
local function TableSetupColumnApply(table_, idx, id, name_offset, flags, init_width_or_weight, user_data)
    local column = table_.Columns[idx]

    -- Assert when passing a width or weight if policy is entirely left to default, to avoid storing width into weight and vice-versa.
    -- Give a grace to users of ImGuiTableFlags.ScrollX.
    if table_.IsDefaultSizingPolicy and band(flags, ImGuiTableColumnFlags.WidthMask_) == 0 and band(flags, ImGuiTableFlags.ScrollX) == 0 then
        IM_ASSERT_USER_ERROR_RET(init_width_or_weight <= 0.0, "TableSetupColumn(): can only specify width/weight if sizing policy is set explicitly in either Table or Column.")
    end

    -- When passing a width automatically enforce WidthFixed policy
    -- (whereas TableSetupColumnFlags would default to WidthAuto if table is not resizable)
    if band(flags, ImGuiTableColumnFlags.WidthMask_) == 0 and init_width_or_weight > 0.0 then
        if band(table_.Flags, ImGuiTableFlags.SizingMask_) == ImGuiTableFlags.SizingFixedFit or band(table_.Flags, ImGuiTableFlags.SizingMask_) == ImGuiTableFlags.SizingFixedSame then
            flags = bor(flags, ImGuiTableColumnFlags.WidthFixed)
        end
    end
    if band(flags, ImGuiTableColumnFlags.AngledHeader) ~= 0 then
        flags = bor(flags, ImGuiTableColumnFlags.NoHeaderLabel)
        table_.AngledHeadersCount = table_.AngledHeadersCount + 1
    end

    TableSetupColumnFlags(table_, column, idx, flags)
    column.ID = id
    column.UserData = user_data
    column.NameOffset = name_offset
    column.InitStretchWeightOrWidth = init_width_or_weight
end

--- @param label                 string?
--- @param flags?                ImGuiTableColumnFlags
--- @param init_width_or_weight? float
--- @param user_data?            ImGuiID
function ImGui.TableSetupColumn(label, flags, init_width_or_weight, user_data)
    if flags == nil then flags = 0 end
    if init_width_or_weight == nil then init_width_or_weight = 0.0 end
    if user_data == nil then user_data = 0 end

    local g = GImGui
    local table_ = g.CurrentTable
    IM_ASSERT_USER_ERROR_RET(table_ ~= nil, "Call should only be done while in BeginTable() scope!")
    IM_ASSERT_USER_ERROR_RET(table_.DeclColumnsCount < table_.ColumnsCount, "TableSetupColumn(): called too many times!")
    IM_ASSERT_USER_ERROR_RET(table_.IsLayoutLocked == false, "TableSetupColumn(): need to call before first row!") -- Table layout is locked when submitting a row or when calling BeginMultiSelect() with box-select.
    IM_ASSERT(band(flags, ImGuiTableColumnFlags.StatusMask_) == 0, "Illegal to pass StatusMask values to TableSetupColumn()")

    -- Store name
    -- FIXME: If we recorded the number of \n in names we could compute header row height
    local name_offset = -1
    if label ~= nil and label ~= "" then
        name_offset = #table_.ColumnsNames
        table_.ColumnsNames[name_offset + 1] = label
    end
    local column_id = (label ~= nil and label ~= "") and ImHashStr(label) or 0

    -- When ID changed or a column moved: defer the request until layout where we will process full reconcile.
    local column_idx = table_.DeclColumnsCount
    table_.DeclColumnsCount = table_.DeclColumnsCount + 1
    local column = table_.Columns[column_idx]

    -- If topology change goes into reconcile mode
    if table_.IsReconcileMode == false and column.ID ~= column_id and not table_.IsNewTable then
        table_.IsReconcileMode = true
    end

    -- Fast/common path
    if table_.IsReconcileMode == false then
        TableSetupColumnApply(table_, column_idx, column_id, name_offset, flags, init_width_or_weight, user_data)
        column.IsNeedReconcileSrc = false; column.IsNeedReconcileDst = false
        local old = table_.TempData.OldColumnsData
        if old and column_idx < table_.TempData.OldColumnsDataSize then
            old[column_idx].IsNeedReconcileSrc = false
        end
        return
    end

    -- Reconcile path: defer applying data to TableUpdateLayout() -> TableReconcileMovedColumns() -> TableSetupColumnApply().
    -- On column count change: search the previous columns:
    -- - the live Columns[] array is truncated on shrink, so a moved column may only exist in old data.
    -- - the live Columns[] array may already be partially reset.
    local reconcile_data = {
        ID = column_id, NameOffset = name_offset, Flags = flags, InitWidthOrWeight = init_width_or_weight, UserData = user_data,
        ColumnNewIdx = column_idx, ColumnOldIdx = -1, ColumnOldData = ImGuiTableColumn(),
    }
    table_.TempData.ReconcileColumnsRequests:push_back(reconcile_data)
    column.NameOffset = name_offset -- Allow TableGetColumnName() to work before layout
    column.IsNeedReconcileSrc = true; column.IsNeedReconcileDst = true
end

-- NB: This was written to be similar to the logic in TableLoadSettingsForColumns().
function ImGui.TableReconcileColumns(table_)
    local temp_data = table_.TempData
    IMGUI_DEBUG_LOG_TABLE("[table] Reconcile columns for table 0x%08X\n", table_.ID)

    local dst_columns = table_.Columns
    local src_columns, src_count
    if temp_data.OldColumnsData == nil then
        src_columns, src_count = table_.Columns, table_.ColumnsSize
    else
        src_columns, src_count = temp_data.OldColumnsData, temp_data.OldColumnsDataSize
    end

    -- Find matches for named columns.
    local matches = 0
    local reconcile_requests = temp_data.ReconcileColumnsRequests
    for _, reconcile_data in reconcile_requests:iter() do
        if reconcile_data.ID ~= 0 then
            for src_n = 0, src_count - 1 do
                local src_column = src_columns[src_n]
                if src_column.ID == reconcile_data.ID and src_column.IsNeedReconcileSrc then
                    local dst_column = dst_columns[reconcile_data.ColumnNewIdx]
                    IM_ASSERT(src_column.IsNeedReconcileSrc and dst_column.IsNeedReconcileDst)
                    src_column.IsNeedReconcileSrc = false; dst_column.IsNeedReconcileDst = false
                    reconcile_data.ColumnOldIdx = src_n
                    reconcile_data.ColumnOldData = TableColumnClone(src_column)
                    matches = matches + 1
                    break
                end
            end
        end
    end

    -- Remaining entries are matched sequentially.
    local dst_idx = 1 -- index in reconcile array (1-based)
    if matches ~= reconcile_requests.Size then
        for src_n = 0, src_count - 1 do
            local src_column = src_columns[src_n]
            if src_column.IsNeedReconcileSrc then
                while dst_idx <= reconcile_requests.Size and reconcile_requests.Data[dst_idx].ColumnOldIdx ~= -1 do
                    dst_idx = dst_idx + 1
                end
                if dst_idx > reconcile_requests.Size then
                    break
                end
                local reconcile_data = reconcile_requests.Data[dst_idx]
                local dst_column = dst_columns[reconcile_data.ColumnNewIdx]
                IM_ASSERT(src_column.IsNeedReconcileSrc and dst_column.IsNeedReconcileDst)
                src_column.IsNeedReconcileSrc = false; dst_column.IsNeedReconcileDst = false
                reconcile_data.ColumnOldIdx = src_n
                reconcile_data.ColumnOldData = TableColumnClone(src_column)
            end
        end
    end

    -- Apply in the final pass. Because it is possible that src_columns == table.Columns we went through a temporary copy.
    for _, reconcile_data in reconcile_requests:iter() do
        TableColumnCopy(table_.Columns[reconcile_data.ColumnNewIdx], reconcile_data.ColumnOldData) -- When old column was not found clear anyway with default-constructed data (which will set IsJustCreated=true)
        TableSetupColumnApply(table_, reconcile_data.ColumnNewIdx, reconcile_data.ID, reconcile_data.NameOffset, reconcile_data.Flags, reconcile_data.InitWidthOrWeight, reconcile_data.UserData)
    end
    ImGui.TableFixDisplayOrder(table_)
    table_.IsSettingsDirty = true -- FIXME-RECONCILE: Necessary?
    table_.IsReconcileMode = false
    reconcile_requests:resize(0) -- GC-ed once in NewFrame()
end

-- [Public]
function ImGui.TableSetupScrollFreeze(columns, rows)
    local g = GImGui
    local table_ = g.CurrentTable
    IM_ASSERT_USER_ERROR_RET(table_ ~= nil, "Call should only be done while in BeginTable() scope!")
    IM_ASSERT(table_.IsLayoutLocked == false, "TableSetupColumn(): need to call before first row!")
    IM_ASSERT(columns >= 0 and columns < IMGUI_TABLE_MAX_COLUMNS)
    IM_ASSERT(rows >= 0 and rows < 128) -- Arbitrary limit

    table_.FreezeColumnsRequest = (band(table_.Flags, ImGuiTableFlags.ScrollX) ~= 0) and mathMin(columns, table_.ColumnsCount) or 0
    table_.FreezeColumnsCount = (table_.InnerWindow.Scroll.x ~= 0.0) and table_.FreezeColumnsRequest or 0
    table_.FreezeRowsRequest = (band(table_.Flags, ImGuiTableFlags.ScrollY) ~= 0) and rows or 0
    table_.FreezeRowsCount = (table_.InnerWindow.Scroll.y ~= 0.0) and table_.FreezeRowsRequest or 0
    table_.IsUnfrozenRows = (table_.FreezeRowsCount == 0) -- Make sure this is set before TableUpdateLayout() so ImGuiListClipper can benefit from it.
end

-------------------------------------------------------------------------------
-- [SECTION] Tables: Simple accessors
-------------------------------------------------------------------------------
-- - TableGetColumnCount()
-- - TableGetColumnName()
-- - TableGetColumnName() [Internal]
-- - TableSetColumnEnabled()
-- - TableGetColumnFlags()
-- - TableGetCellBgRect() [Internal]
-- - TableGetColumnResizeID() [Internal]
-- - TableGetHoveredColumn() [Internal]
-- - TableGetHoveredRow() [Internal]
-- - TableSetBgColor()
-------------------------------------------------------------------------------

-- [Internal] Small optimization to avoid calls to PopClipRect/SetCurrentChannel/PushClipRect in sequences,
-- they would meddle many times with the underlying ImDrawCmd.
-- Instead, we do a preemptive overwrite of clipping rectangle _without_ altering the command-buffer and let
-- the subsequent single call to SetCurrentChannel() does it things once.

function ImGui.SetWindowClipRectBeforeSetChannel(window, clip_rect)
    -- [Luau] scalar copies, no temporary ImVec4: the clip rect stack top is a uniquely owned ImVec4 (PushClipRect always pushes a fresh one), so overwrite it in place
    local min, max = clip_rect.Min, clip_rect.Max
    local x1, y1, x2, y2 = min.x, min.y, max.x, max.y
    local wcr = window.ClipRect
    wcr.Min.x = x1; wcr.Min.y = y1; wcr.Max.x = x2; wcr.Max.y = y2
    local draw_list = window.DrawList
    local hcr = draw_list._CmdHeader.ClipRect
    hcr.x = x1; hcr.y = y1; hcr.z = x2; hcr.w = y2
    local stack = draw_list._ClipRectStack
    local top = stack.Data[stack.Size]
    if top ~= nil then
        top.x = x1; top.y = y1; top.z = x2; top.w = y2
    else
        stack.Data[stack.Size] = ImVec4(x1, y1, x2, y2)
    end
end

function ImGui.TableGetColumnCount()
    local g = GImGui
    local table_ = g.CurrentTable
    return table_ and table_.ColumnsCount or 0
end

-- Overloads: TableGetColumnName(column_n?) / TableGetColumnName(table, column_n)
function ImGui.TableGetColumnName(a, b)
    local table_, column_n
    if type(a) == "table" then
        table_, column_n = a, b
    else
        local g = GImGui
        table_ = g.CurrentTable
        if not table_ then
            return nil
        end
        column_n = a or -1
        if column_n < 0 then
            column_n = table_.CurrentColumn
        end
    end
    if table_.IsLayoutLocked == false and column_n >= table_.DeclColumnsCount then
        return "" -- NameOffset is invalid at this point
    end
    local column = table_.Columns[column_n]
    if column.NameOffset == -1 then
        return ""
    end
    return table_.ColumnsNames[column.NameOffset + 1]
end

-- Change user accessible enabled/disabled state of a column (often perceived as "showing/hiding" from users point of view)
-- Note that end-user can use the context menu to change this themselves (right-click in headers, or right-click in columns body with ImGuiTableFlags.ContextMenuInBody)
-- - Require table to have the ImGuiTableFlags.Hideable flag because we are manipulating user accessible state.
-- - Request will be applied during next layout, which happens on the first call to TableNextRow() after BeginTable().
-- - For the getter you can test (TableGetColumnFlags() & ImGuiTableColumnFlags.IsEnabled) ~= 0.
-- - Alternative: the ImGuiTableColumnFlags.Disabled is an overriding/master disable flag which will also hide the column from context menu.
function ImGui.TableSetColumnEnabled(column_n, enabled)
    local g = GImGui
    local table_ = g.CurrentTable
    IM_ASSERT_USER_ERROR_RET(table_ ~= nil, "Call should only be done while in BeginTable() scope!")
    IM_ASSERT(band(table_.Flags, ImGuiTableFlags.Hideable) ~= 0) -- See comments above
    if column_n < 0 then
        column_n = table_.CurrentColumn
    end
    IM_ASSERT(column_n >= 0 and column_n < table_.ColumnsCount)
    local column = table_.Columns[column_n]
    column.IsUserEnabledNextFrame = enabled
end

-- We allow querying for an extra column in order to poll the IsHovered state of the right-most section
function ImGui.TableGetColumnFlags(column_n)
    if column_n == nil then column_n = -1 end
    local g = GImGui
    local table_ = g.CurrentTable
    if not table_ then
        return ImGuiTableColumnFlags.None
    end
    if column_n < 0 then
        column_n = table_.CurrentColumn
    end
    if column_n == table_.ColumnsCount then
        return (table_.HoveredColumnBody == column_n) and ImGuiTableColumnFlags.IsHovered or ImGuiTableColumnFlags.None
    end
    return table_.Columns[column_n].Flags
end

-- Return the cell rectangle based on currently known height.
-- - Important: we generally don't know our row height until the end of the row, so Max.y will be incorrect in many situations.
--   The only case where this is correct is if we provided a min_row_height to TableNextRow() and don't go below it, or in TableEndRow() when we locked that height.
-- - Important: if ImGuiTableFlags.PadOuterX is set but ImGuiTableFlags.PadInnerX is not set, the outer-most left and right
--   columns report a small offset so their CellBgRect can extend up to the outer border.
--   FIXME: But the rendering code in TableEndRow() nullifies that with clamping required for scrolling.
function ImGui.TableGetCellBgRect(table_, column_n)
    local column = table_.Columns[column_n]
    local x1 = column.MinX
    local x2 = column.MaxX
    --if column.PrevEnabledColumn == -1 then
    --    x1 = x1 - table.OuterPaddingX
    --if column.NextEnabledColumn == -1 then
    --    x2 = x2 + table.OuterPaddingX
    x1 = mathMax(x1, table_.WorkRect.Min.x)
    x2 = mathMin(x2, table_.WorkRect.Max.x)
    return ImRect(x1, table_.RowPosY1, x2, table_.RowPosY2)
end

-- Return the resizing ID for the right-side of the given column.
function ImGui.TableGetColumnResizeID(table_, column_n, instance_no)
    if instance_no == nil then instance_no = 0 end
    IM_ASSERT(column_n >= 0 and column_n < table_.ColumnsCount)
    local instance_id = ImGui.TableGetInstanceID(table_, instance_no)
    return band(instance_id + 1 + column_n, 0xFFFFFFFF) -- FIXME: #6140: still not ideal
end

-- Return -1 when table is not hovered. return columns_count if hovering the unused space at the right of the right-most visible column.
function ImGui.TableGetHoveredColumn()
    local g = GImGui
    local table_ = g.CurrentTable
    if not table_ then
        return -1
    end
    return table_.HoveredColumnBody
end

-- Return -1 when table is not hovered. Return maxrow+1 if in table but below last submitted row.
-- *IMPORTANT* Unlike TableGetHoveredColumn(), this has a one frame latency in updating the value.
-- This difference with is the reason why this is not public yet.
function ImGui.TableGetHoveredRow()
    local g = GImGui
    local table_ = g.CurrentTable
    if not table_ then
        return -1
    end
    local table_instance = ImGui.TableGetInstanceData(table_, table_.InstanceCurrent)
    return table_instance.HoveredRowLast
end

function ImGui.TableSetBgColor(target, color, column_n)
    if column_n == nil then column_n = -1 end
    local g = GImGui
    local table_ = g.CurrentTable
    IM_ASSERT_USER_ERROR_RET(table_ ~= nil, "Call should only be done while in BeginTable() scope!")
    IM_ASSERT(target ~= ImGuiTableBgTarget.None)

    if color == IM_COL32_DISABLE then
        color = 0
    end

    -- We cannot draw neither the cell or row background immediately as we don't know the row height at this point in time.
    if target == ImGuiTableBgTarget.CellBg then
        if table_.RowPosY1 > table_.InnerClipRect.Max.y then -- Discard
            return
        end
        if column_n == -1 then
            column_n = table_.CurrentColumn
        end
        if not BitTest(table_.VisibleMaskByIndex, column_n) then
            return
        end
        if table_.RowCellDataCurrent < 0 or table_.RowCellData[table_.RowCellDataCurrent].Column ~= column_n then
            table_.RowCellDataCurrent = table_.RowCellDataCurrent + 1
        end
        local cell_data = table_.RowCellData[table_.RowCellDataCurrent]
        cell_data.BgColor = color
        cell_data.Column = column_n
    elseif target == ImGuiTableBgTarget.RowBg0 or target == ImGuiTableBgTarget.RowBg1 then
        if table_.RowPosY1 > table_.InnerClipRect.Max.y then -- Discard
            return
        end
        IM_ASSERT(column_n == -1)
        local bg_idx = (target == ImGuiTableBgTarget.RowBg1) and 1 or 0
        table_.RowBgColor[bg_idx] = color
    else
        IM_ASSERT(false)
    end
end

-------------------------------------------------------------------------------
-- [SECTION] Tables: Row changes
-------------------------------------------------------------------------------
-- - TableGetRowIndex()
-- - TableNextRow()
-- - TableBeginRow() [Internal]
-- - TableEndRow() [Internal]
-------------------------------------------------------------------------------

-- [Public] Note: for row coloring we use .RowBgColorCounter which is the same value without counting header rows
function ImGui.TableGetRowIndex()
    local g = GImGui
    local table_ = g.CurrentTable
    if not table_ then
        return 0
    end
    return table_.CurrentRow
end

-- [Public] Starts into the first cell of a new row
--- @param row_flags?      ImGuiTableRowFlags
--- @param row_min_height? float
function ImGui.TableNextRow(row_flags, row_min_height)
    if row_flags == nil then row_flags = 0 end
    if row_min_height == nil then row_min_height = 0.0 end

    local g = GImGui
    local table_ = g.CurrentTable

    if not table_.IsLayoutLocked then
        ImGui.TableUpdateLayout(table_)
    end
    if table_.IsInsideRow then
        ImGui.TableEndRow(table_)
    end

    table_.LastRowFlags = table_.RowFlags
    table_.RowFlags = row_flags
    table_.RowCellPaddingY = g.Style.CellPadding.y
    table_.RowMinHeight = row_min_height
    ImGui.TableBeginRow(table_)

    -- We honor min_row_height requested by user, but cannot guarantee per-row maximum height,
    -- because that would essentially require a unique clipping rectangle per-cell.
    table_.RowPosY2 = mathMax(table_.RowPosY2 + table_.RowCellPaddingY * 2.0, table_.RowPosY1 + row_min_height) -- [Luau] inline ImMax

    -- Disable output until user calls TableNextColumn()
    table_.InnerWindow.SkipItems = true
end

-- [Internal] Only called by TableNextRow()
function ImGui.TableBeginRow(table_)
    local window = table_.InnerWindow
    IM_ASSERT(not table_.IsInsideRow)

    -- New row
    table_.CurrentRow = table_.CurrentRow + 1
    table_.CurrentColumn = -1
    table_.RowBgColor[0] = IM_COL32_DISABLE; table_.RowBgColor[1] = IM_COL32_DISABLE
    table_.RowCellDataCurrent = -1
    table_.IsInsideRow = true

    -- Begin frozen rows
    local next_y1 = table_.RowPosY2
    if table_.CurrentRow == 0 and table_.FreezeRowsCount > 0 then
        next_y1 = table_.OuterRect.Min.y
        window.DC.CursorPos.y = next_y1
    end

    table_.RowPosY1 = next_y1; table_.RowPosY2 = next_y1
    table_.RowTextBaseline = 0.0
    local dc = window.DC -- [Luau] cache
    table_.RowIndentOffsetX = dc.Indent.x - table_.HostIndentX -- Lock indent

    dc.PrevLineTextBaseOffset = 0.0
    dc.CursorPosPrevLine.x = dc.CursorPos.x
    dc.CursorPosPrevLine.y = dc.CursorPos.y + table_.RowCellPaddingY -- This allows users to call SameLine() to share LineSize between columns.
    dc.PrevLineSize.x = 0.0; dc.PrevLineSize.y = 0.0 -- This allows users to call SameLine() to share LineSize between columns, and to call it from first column too.
    dc.CurrLineSize.x = 0.0; dc.CurrLineSize.y = 0.0
    dc.IsSameLine = false; dc.IsSetPos = false
    dc.CursorMaxPos.y = next_y1

    -- Making the header BG color non-transparent will allow us to overlay it multiple times when handling smooth dragging.
    if band(table_.RowFlags, ImGuiTableRowFlags.Headers) ~= 0 then
        ImGui.TableSetBgColor(ImGuiTableBgTarget.RowBg0, ImGui.GetColorU32(ImGuiCol.TableHeaderBg))
        if table_.CurrentRow == 0 then
            table_.IsUsingHeaders = true
        end
    end
end

-- [Luau] scratch vectors for TableEndRow() row background (never escape)
local TableEndRow_RowMin, TableEndRow_RowMax = ImVec2(), ImVec2()

-- [Internal] Called by TableNextRow()
function ImGui.TableEndRow(table_)
    local g = GImGui
    local window = g.CurrentWindow
    IM_ASSERT(window == table_.InnerWindow)
    IM_ASSERT(table_.IsInsideRow)

    if table_.CurrentColumn ~= -1 then
        ImGui.TableEndCell(table_)
        table_.CurrentColumn = -1
    end

    -- Logging
    if g.LogEnabled then
        ImGui.LogRenderedText(nil, "|")
    end

    -- Position cursor at the bottom of our row so it can be used for e.g. clipping calculation. However it is
    -- likely that the next call to TableBeginCell() will reposition the cursor to take account of vertical padding.
    window.DC.CursorPos.y = table_.RowPosY2

    -- Row background fill
    local bg_y1 = table_.RowPosY1
    local bg_y2 = table_.RowPosY2
    local unfreeze_rows_actual = (table_.CurrentRow + 1 == table_.FreezeRowsCount)
    local unfreeze_rows_request = (table_.CurrentRow + 1 == table_.FreezeRowsRequest)
    local table_instance = (table_.InstanceCurrent == 0) and table_.InstanceDataFirst or ImGui.TableGetInstanceData(table_, table_.InstanceCurrent) -- [Luau] inline common case
    if band(table_.RowFlags, ImGuiTableRowFlags.Headers) ~= 0 and (table_.CurrentRow == 0 or band(table_.LastRowFlags, ImGuiTableRowFlags.Headers) ~= 0) then
        table_instance.LastTopHeadersRowHeight = table_instance.LastTopHeadersRowHeight + bg_y2 - bg_y1
    end

    local is_visible = (bg_y2 >= table_.InnerClipRect.Min.y and bg_y1 <= table_.InnerClipRect.Max.y)
    if is_visible then
        -- Update data for TableGetHoveredRow()
        if table_.HoveredColumnBody ~= -1 and g.IO.MousePos.y >= bg_y1 and g.IO.MousePos.y < bg_y2 and table_instance.HoveredRowNext < 0 then
            table_instance.HoveredRowNext = table_.CurrentRow
        end

        -- Decide of background color for the row
        local bg_col0 = 0
        local bg_col1 = 0
        if table_.RowBgColor[0] ~= IM_COL32_DISABLE then
            bg_col0 = table_.RowBgColor[0]
        elseif band(table_.Flags, ImGuiTableFlags.RowBg) ~= 0 then
            bg_col0 = ImGui.GetColorU32((band(table_.RowBgColorCounter, 1) ~= 0) and ImGuiCol.TableRowBgAlt or ImGuiCol.TableRowBg)
        end
        if table_.RowBgColor[1] ~= IM_COL32_DISABLE then
            bg_col1 = table_.RowBgColor[1]
        end

        -- Decide of top border color
        local top_border_col = 0
        local border_size = TABLE_BORDER_SIZE
        if table_.CurrentRow > 0 and band(table_.Flags, ImGuiTableFlags.BordersInnerH) ~= 0 then
            top_border_col = (band(table_.LastRowFlags, ImGuiTableRowFlags.Headers) ~= 0) and table_.BorderColorStrong or table_.BorderColorLight
        end

        local draw_cell_bg_color = table_.RowCellDataCurrent >= 0
        local draw_strong_bottom_border = unfreeze_rows_actual
        if bor(bg_col0, bg_col1, top_border_col) ~= 0 or draw_strong_bottom_border or draw_cell_bg_color then
            -- In theory we could call SetWindowClipRectBeforeSetChannel() but since we know TableEndRow() is
            -- always followed by a change of clipping rectangle we perform the smallest overwrite possible here.
            if band(table_.Flags, ImGuiTableFlags.NoClip) == 0 then
                -- [Luau] scalar copy, no temporary ImVec4
                local src, dst = table_.Bg0ClipRectForDrawCmd, window.DrawList._CmdHeader.ClipRect
                dst.x = src.Min.x; dst.y = src.Min.y; dst.z = src.Max.x; dst.w = src.Max.y
            end
            table_.DrawSplitter:SetCurrentChannel(window.DrawList, TABLE_DRAW_CHANNEL_BG0)
        end

        -- Draw row background
        -- We soft/cpu clip this so all backgrounds and borders can share the same clipping rectangle
        if bg_col0 ~= 0 or bg_col1 ~= 0 then
            -- [Luau] row_rect = ImRect(WorkRect.Min.x, bg_y1, WorkRect.Max.x, bg_y2); row_rect:ClipWith(BgClipRect), in scratch vectors (only read by AddRectFilled)
            local bg_clip_rect = table_.BgClipRect
            local row_min, row_max = TableEndRow_RowMin, TableEndRow_RowMax
            row_min.x = mathMax(table_.WorkRect.Min.x, bg_clip_rect.Min.x); row_min.y = mathMax(bg_y1, bg_clip_rect.Min.y)
            row_max.x = mathMin(table_.WorkRect.Max.x, bg_clip_rect.Max.x); row_max.y = mathMin(bg_y2, bg_clip_rect.Max.y)
            if bg_col0 ~= 0 and row_min.y < row_max.y then
                window.DrawList:AddRectFilled(row_min, row_max, bg_col0)
            end
            if bg_col1 ~= 0 and row_min.y < row_max.y then
                window.DrawList:AddRectFilled(row_min, row_max, bg_col1)
            end
        end

        -- Draw cell background color
        if draw_cell_bg_color then
            for cell_n = 0, table_.RowCellDataCurrent do
                local cell_data = table_.RowCellData[cell_n]
                -- As we render the BG here we need to clip things (for layout we would not)
                -- FIXME: This cancels the OuterPadding addition done by TableGetCellBgRect(), need to keep it while rendering correctly while scrolling.
                local column = table_.Columns[cell_data.Column]
                local cell_bg_rect = ImGui.TableGetCellBgRect(table_, cell_data.Column)
                cell_bg_rect:ClipWith(table_.BgClipRect)
                cell_bg_rect.Min.x = mathMax(cell_bg_rect.Min.x, column.ClipRect.Min.x) -- So that first column after frozen one gets clipped when scrolling
                cell_bg_rect.Max.x = mathMin(cell_bg_rect.Max.x, column.MaxX)
                if cell_bg_rect.Min.y < cell_bg_rect.Max.y then
                    window.DrawList:AddRectFilled(cell_bg_rect.Min, cell_bg_rect.Max, cell_data.BgColor)
                end
            end
        end

        -- Draw top border
        if top_border_col ~= 0 and bg_y1 >= table_.BgClipRect.Min.y and bg_y1 < table_.BgClipRect.Max.y then
            window.DrawList:AddLineH(table_.BorderX1, table_.BorderX2, bg_y1, top_border_col, border_size)
        end

        -- Draw bottom border at the row unfreezing mark (always strong)
        if draw_strong_bottom_border and bg_y2 >= table_.BgClipRect.Min.y and bg_y2 < table_.BgClipRect.Max.y then
            window.DrawList:AddLineH(table_.BorderX1, table_.BorderX2, bg_y2, table_.BorderColorStrong, border_size)
        end
    end

    -- End frozen rows (when we are past the last frozen row line, teleport cursor and alter clipping rectangle)
    -- - We need to do that in TableEndRow() instead of TableBeginRow() so the list clipper can mark
    --   end of row and get the new cursor position.
    if unfreeze_rows_request then
        IM_ASSERT(table_.FreezeRowsRequest > 0)
        for column_n = 0, table_.ColumnsCount - 1 do
            table_.Columns[column_n].NavLayerCurrent = table_.NavLayer
        end
        local y0 = mathMax(table_.RowPosY2 + 1, table_.InnerClipRect.Min.y)
        table_instance.LastFrozenHeight = y0 - table_.OuterRect.Min.y

        if unfreeze_rows_actual then
            IM_ASSERT(table_.IsUnfrozenRows == false)
            table_.IsUnfrozenRows = true

            -- BgClipRect starts as table.InnerClipRect, reduce it now and make BgClipRectForDrawCmd == BgClipRect
            local min_y = mathMin(y0, table_.InnerClipRect.Max.y)
            table_.BgClipRect.Min.y = min_y; table_.Bg2ClipRectForDrawCmd.Min.y = min_y
            table_.BgClipRect.Max.y = table_.InnerClipRect.Max.y; table_.Bg2ClipRectForDrawCmd.Max.y = table_.InnerClipRect.Max.y
            table_.Bg2DrawChannelCurrent = table_.Bg2DrawChannelUnfrozen
            IM_ASSERT(table_.Bg2ClipRectForDrawCmd.Min.y <= table_.Bg2ClipRectForDrawCmd.Max.y)

            local row_height = table_.RowPosY2 - table_.RowPosY1
            table_.RowPosY2 = table_.WorkRect.Min.y + table_.RowPosY2 - table_.OuterRect.Min.y
            window.DC.CursorPos.y = table_.RowPosY2
            table_.RowPosY1 = table_.RowPosY2 - row_height
            for column_n = 0, table_.ColumnsCount - 1 do
                local column = table_.Columns[column_n]
                column.DrawChannelCurrent = column.DrawChannelUnfrozen
                column.ClipRect.Min.y = table_.Bg2ClipRectForDrawCmd.Min.y
            end

            -- Update cliprect ahead of TableBeginCell() so clipper can access to new ClipRect.Min.y
            ImGui.SetWindowClipRectBeforeSetChannel(window, table_.Columns[0].ClipRect)
            table_.DrawSplitter:SetCurrentChannel(window.DrawList, table_.Columns[0].DrawChannelCurrent)
        end
    end

    if band(table_.RowFlags, ImGuiTableRowFlags.Headers) == 0 then
        table_.RowBgColorCounter = table_.RowBgColorCounter + 1
    end
    table_.IsInsideRow = false
end

-------------------------------------------------------------------------------
-- [SECTION] Tables: Columns changes
-------------------------------------------------------------------------------
-- - TableGetColumnIndex()
-- - TableSetColumnIndex()
-- - TableNextColumn()
-- - TableBeginCell() [Internal]
-- - TableEndCell() [Internal]
-------------------------------------------------------------------------------

function ImGui.TableGetColumnIndex()
    local g = GImGui
    local table_ = g.CurrentTable
    if not table_ then
        return 0
    end
    return table_.CurrentColumn
end

-- [Public] Append into a specific column
function ImGui.TableSetColumnIndex(column_n)
    local g = GImGui
    local table_ = g.CurrentTable
    if not table_ then
        return false
    end

    if table_.CurrentColumn ~= column_n then
        if table_.CurrentColumn ~= -1 then
            ImGui.TableEndCell(table_)
        end
        if not (column_n >= 0 and column_n < table_.ColumnsCount) then
            IM_ASSERT_USER_ERROR(false, "TableSetColumnIndex() invalid column index!")
            return false
        end
        ImGui.TableBeginCell(table_, column_n)
    end

    -- Return whether the column is visible. User may choose to skip submitting items based on this return value,
    -- however they shouldn't skip submitting for columns that may have the tallest contribution to row height.
    return table_.Columns[column_n].IsRequestOutput
end

-- [Public] Append into the next column, wrap and create a new row when already on last column

function ImGui.TableNextColumn()
    local g = GImGui
    local table_ = g.CurrentTable
    if not table_ then
        return false
    end

    local current_column = table_.CurrentColumn
    local next_column
    if table_.IsInsideRow and current_column + 1 < table_.ColumnsCount then
        if current_column ~= -1 then
            ImGui.TableEndCell(table_)
        end
        next_column = current_column + 1
    else
        ImGui.TableNextRow()
        next_column = 0
    end
    ImGui.TableBeginCell(table_, next_column)

    -- Return whether the column is visible. User may choose to skip submitting items based on this return value,
    -- however they shouldn't skip submitting for columns that may have the tallest contribution to row height.
    return table_.Columns[next_column].IsRequestOutput
end

-- [Internal] Called by TableSetColumnIndex()/TableNextColumn()
-- This is called very frequently, so we need to be mindful of unnecessary overhead.
-- FIXME-TABLE FIXME-OPT: Could probably shortcut some things for non-active or clipped columns.

function ImGui.TableBeginCell(table_, column_n)
    local g = GImGui
    local column = table_.Columns[column_n]
    local window = table_.InnerWindow
    local dc = window.DC -- [Luau] cache
    table_.CurrentColumn = column_n

    -- Start position is roughly ~~ CellRect.Min + CellPadding + Indent
    local start_x = column.WorkMinX
    if band(column.Flags, ImGuiTableColumnFlags.IndentEnable) ~= 0 then
        start_x = start_x + table_.RowIndentOffsetX -- ~~ += window.DC.Indent.x - table.HostIndentX, except we locked it for the row.
    end

    local start_y = table_.RowPosY1 + table_.RowCellPaddingY
    dc.CursorPos.x = start_x
    dc.CursorPos.y = start_y
    dc.CursorMaxPos.x = start_x
    dc.ColumnsOffset.x = start_x - window.Pos.x - dc.Indent.x -- FIXME-WORKRECT
    dc.CursorPosPrevLine.x = start_x -- PrevLine.y is preserved. This allows users to call SameLine() to share LineSize between columns.
    dc.CurrLineTextBaseOffset = table_.RowTextBaseline
    dc.NavLayerCurrent = column.NavLayerCurrent

    -- Note how WorkRect.Max.y is only set once during layout
    local work_rect = window.WorkRect
    work_rect.Min.y = start_y
    work_rect.Min.x = column.WorkMinX
    work_rect.Max.x = column.WorkMaxX
    dc.ItemWidth = column.ItemWidth

    local skip_items = column.IsSkipItems
    window.SkipItems = skip_items
    if skip_items then
        g.LastItemData.ID = 0
        g.LastItemData.StatusFlags = 0
    end

    -- Also see TablePushColumnChannel()
    -- [Luau] inline the SetCurrentChannel() early-out (same channel) to skip the method call
    local splitter = table_.DrawSplitter
    if band(table_.Flags, ImGuiTableFlags.NoClip) ~= 0 then
        -- FIXME: if we end up drawing all borders/bg in EndTable, could remove this and just assert that channel hasn't changed.
        if splitter._Current ~= TABLE_DRAW_CHANNEL_NOCLIP then
            splitter:SetCurrentChannel(window.DrawList, TABLE_DRAW_CHANNEL_NOCLIP)
        end
        --IM_ASSERT(table.DrawSplitter._Current == TABLE_DRAW_CHANNEL_NOCLIP)
    else
        -- FIXME-TABLE: Could avoid this if draw channel is dummy channel?
        ImGui.SetWindowClipRectBeforeSetChannel(window, column.ClipRect)
        local channel = column.DrawChannelCurrent
        if splitter._Current ~= channel then
            splitter:SetCurrentChannel(window.DrawList, channel)
        end
    end

    -- Logging
    if g.LogEnabled and not column.IsSkipItems then
        ImGui.LogRenderedText(window.DC.CursorPos, "|")
        g.LogLinePosY = FLT_MAX
    end
end

-- [Internal] Called by TableNextRow()/TableSetColumnIndex()/TableNextColumn()

function ImGui.TableEndCell(table_)
    local column = table_.Columns[table_.CurrentColumn]
    local window = table_.InnerWindow
    local dc = window.DC -- [Luau] cache; mathMax() inlined as math.max below

    if dc.IsSetPos then
        ImGui.ErrorCheckUsingSetCursorPosToExtendParentBoundaries()
    end

    -- Report maximum position so we can infer content size per column.
    local cursor_max_pos = dc.CursorMaxPos
    local x = cursor_max_pos.x
    if band(table_.RowFlags, ImGuiTableRowFlags.Headers) ~= 0 then
        column.ContentMaxXHeadersUsed = mathMax(column.ContentMaxXHeadersUsed, x) -- Useful in case user submit contents in header row that is not a TableHeader() call
    elseif table_.IsUnfrozenRows then
        column.ContentMaxXUnfrozen = mathMax(column.ContentMaxXUnfrozen, x)
    else
        column.ContentMaxXFrozen = mathMax(column.ContentMaxXFrozen, x)
    end
    if column.IsEnabled then
        table_.RowPosY2 = mathMax(table_.RowPosY2, cursor_max_pos.y + table_.RowCellPaddingY)
    end
    column.ItemWidth = dc.ItemWidth

    -- Propagate text baseline for the entire row
    -- FIXME-TABLE: Here we propagate text baseline from the last line of the cell.. instead of the first one.
    table_.RowTextBaseline = mathMax(table_.RowTextBaseline, dc.PrevLineTextBaseOffset)
end

-------------------------------------------------------------------------------
-- [SECTION] Tables: Columns width management
-------------------------------------------------------------------------------
-- - TableGetMaxColumnWidth() [Internal]
-- - TableGetColumnWidthAuto() [Internal]
-- - TableSetColumnWidth()
-- - TableSetColumnWidthAutoSingle() [Internal]
-- - TableSetColumnWidthAutoAll() [Internal]
-- - TableUpdateColumnsWeightFromWidth() [Internal]
-------------------------------------------------------------------------------
-- Note that actual columns widths are computed in TableUpdateLayout().
-------------------------------------------------------------------------------

-- Maximum column content width given current layout. Use column.MinX so this value differs on a per-column basis.
function ImGui.TableCalcMaxColumnWidth(table_, column_n)
    local column = table_.Columns[column_n]
    local max_width = FLT_MAX
    local min_column_distance = table_.MinColumnWidth + table_.CellPaddingX * 2.0 + table_.CellSpacingX1 + table_.CellSpacingX2
    if band(table_.Flags, ImGuiTableFlags.ScrollX) ~= 0 then
        -- Frozen columns can't reach beyond visible width else scrolling will naturally break.
        -- (we use DisplayOrder as within a set of multiple frozen column reordering is possible)
        if column.DisplayOrder < table_.FreezeColumnsRequest then
            max_width = (table_.InnerClipRect.Max.x - (table_.FreezeColumnsRequest - column.DisplayOrder) * min_column_distance) - column.MinX
            max_width = max_width - table_.OuterPaddingX - table_.CellPaddingX - table_.CellSpacingX2
        end
    elseif band(table_.Flags, ImGuiTableFlags.NoKeepColumnsVisible) == 0 then
        -- If horizontal scrolling if disabled, we apply a final lossless shrinking of columns in order to make
        -- sure they are all visible. Because of this we also know that all of the columns will always fit in
        -- table.WorkRect and therefore in table.InnerRect (because ScrollX is off)
        -- FIXME-TABLE: This is solved incorrectly but also quite a difficult problem to fix as we also want ClipRect width to match.
        -- See "table_width_distrib" and "table_width_keep_visible" tests
        max_width = table_.WorkRect.Max.x - (table_.ColumnsEnabledCount - column.IndexWithinEnabledSet - 1) * min_column_distance - column.MinX
        --max_width = max_width - table.CellSpacingX1
        max_width = max_width - table_.CellSpacingX2
        max_width = max_width - table_.CellPaddingX * 2.0
        max_width = max_width - table_.OuterPaddingX
    end
    return max_width
end

-- Note this is meant to be stored in column.WidthAuto, please generally use the WidthAuto field
function ImGui.TableGetColumnWidthAuto(table_, column)
    local content_width_body = mathMax(column.ContentMaxXFrozen, column.ContentMaxXUnfrozen) - column.WorkMinX
    local content_width_headers = column.ContentMaxXHeadersIdeal - column.WorkMinX
    local width_auto = content_width_body
    if band(column.Flags, ImGuiTableColumnFlags.NoHeaderWidth) == 0 then
        width_auto = mathMax(width_auto, content_width_headers)
    end

    -- Non-resizable fixed columns preserve their requested width
    if band(column.Flags, ImGuiTableColumnFlags.WidthFixed) ~= 0 and column.InitStretchWeightOrWidth > 0.0 then
        if band(table_.Flags, ImGuiTableFlags.Resizable) == 0 or band(column.Flags, ImGuiTableColumnFlags.NoResize) ~= 0 then
            width_auto = column.InitStretchWeightOrWidth
        end
    end

    return mathMax(width_auto, table_.MinColumnWidth)
end

-- 'width' = inner column width, without padding
function ImGui.TableSetColumnWidth(column_n, width)
    local g = GImGui
    local table_ = g.CurrentTable
    IM_ASSERT(table_ ~= nil and table_.IsLayoutLocked == false)
    IM_ASSERT(column_n >= 0 and column_n < table_.ColumnsCount)
    local column_0 = table_.Columns[column_n]
    local column_0_width = width

    -- Apply constraints early
    -- Compare both requested and actual given width to avoid overwriting requested width when column is stuck (minimum size, bounded)
    IM_ASSERT(table_.MinColumnWidth > 0.0)
    local min_width = table_.MinColumnWidth
    local max_width = mathMax(min_width, column_0.WidthMax) -- Don't use TableCalcMaxColumnWidth() here as it would rely on MinX from last instance (#7933)
    column_0_width = ImClamp(column_0_width, min_width, max_width)
    if column_0.WidthGiven == column_0_width or column_0.WidthRequest == column_0_width then
        return
    end

    --IMGUI_DEBUG_PRINT("TableSetColumnWidth(%d, %.1f->%.1f)\n", column_0_idx, column_0.WidthGiven, column_0_width)
    local column_1 = (column_0.NextEnabledColumn ~= -1) and table_.Columns[column_0.NextEnabledColumn] or nil

    -- In this surprisingly not simple because of how we support mixing Fixed and multiple Stretch columns.
    -- - All fixed: easy.
    -- - All stretch: easy.
    -- - One or more fixed + one stretch: easy.
    -- - One or more fixed + more than one stretch: tricky.
    -- Qt when manual resize is enabled only supports a single _trailing_ stretch column, we support more cases here.

    -- When forwarding resize from Wn| to Fn+1| we need to be considerate of the _NoResize flag on Fn+1.
    -- FIXME-TABLE: Find a way to rewrite all of this so interactions feel more consistent for the user.
    -- Scenarios:
    -- - F1 F2 F3  resize from F1| or F2|   --> ok: alter .WidthRequested of Fixed column. Subsequent columns will be offset.
    -- - F1 F2 F3  resize from F3|          --> ok: alter .WidthRequested of Fixed column. If active, ScrollX extent can be altered.
    -- - F1 F2 W3  resize from F1| or F2|   --> ok: alter .WidthRequested of Fixed column. If active, ScrollX extent can be altered, but it doesn't make much sense as the Stretch column will always be minimal size.
    -- - F1 F2 W3  resize from W3|          --> ok: no-op (disabled by Resize Rule 1)
    -- - W1 W2 W3  resize from W1| or W2|   --> ok
    -- - W1 W2 W3  resize from W3|          --> ok: no-op (disabled by Resize Rule 1)
    -- - W1 F2 F3  resize from F3|          --> ok: no-op (disabled by Resize Rule 1)
    -- - W1 F2     resize from F2|          --> ok: no-op (disabled by Resize Rule 1)
    -- - W1 W2 F3  resize from W1| or W2|   --> ok
    -- - W1 F2 W3  resize from W1| or F2|   --> ok
    -- - F1 W2 F3  resize from W2|          --> ok
    -- - F1 W3 F2  resize from W3|          --> ok
    -- - W1 F2 F3  resize from W1|          --> ok: equivalent to resizing |F2. F3 will not move.
    -- - W1 F2 F3  resize from F2|          --> ok
    -- All resizes from a Wx columns are locking other columns.

    -- Possible improvements:
    -- - W1 W2 W3  resize W1|               --> to not be stuck, both W2 and W3 would stretch down. Seems possible to fix. Would be most beneficial to simplify resize of all-weighted columns.
    -- - W3 F1 F2  resize W3|               --> to not be stuck past F1|, both F1 and F2 would need to stretch down, which would be lossy or ambiguous. Seems hard to fix.

    -- [Resize Rule 1] Can't resize from right of right-most visible column if there is any Stretch column. Implemented in TableUpdateLayout().

    -- If we have all Fixed columns OR resizing a Fixed column that doesn't come after a Stretch one, we can do an offsetting resize.
    -- This is the preferred resize path
    if band(column_0.Flags, ImGuiTableColumnFlags.WidthFixed) ~= 0 then
        if not column_1 or table_.LeftMostStretchedColumn == -1 or table_.Columns[table_.LeftMostStretchedColumn].DisplayOrder >= column_0.DisplayOrder then
            column_0.WidthRequest = column_0_width
            table_.IsSettingsDirty = true
            return
        end
    end

    -- We can also use previous column if there's no next one (this is used when doing an auto-fit on the right-most stretch column)
    if column_1 == nil then
        column_1 = (column_0.PrevEnabledColumn ~= -1) and table_.Columns[column_0.PrevEnabledColumn] or nil
    end
    if column_1 == nil then
        return
    end

    -- Resizing from right-side of a Stretch column before a Fixed column forward sizing to left-side of fixed column.
    -- (old_a + old_b == new_a + new_b) --> (new_a == old_a + old_b - new_b)
    local column_1_width = mathMax(column_1.WidthRequest - (column_0_width - column_0.WidthRequest), min_width)
    column_0_width = column_0.WidthRequest + column_1.WidthRequest - column_1_width
    IM_ASSERT(column_0_width > 0.0 and column_1_width > 0.0)
    column_0.WidthRequest = column_0_width
    column_1.WidthRequest = column_1_width
    if band(bor(column_0.Flags, column_1.Flags), ImGuiTableColumnFlags.WidthStretch) ~= 0 then
        ImGui.TableUpdateColumnsWeightFromWidth(table_)
    end
    table_.IsSettingsDirty = true
end

-- Disable clipping then auto-fit, will take 2 frames
-- (we don't take a shortcut for unclipped columns to reduce inconsistencies when e.g. resizing multiple columns)
function ImGui.TableSetColumnWidthAutoSingle(table_, column_n)
    -- Single auto width uses auto-fit
    local column = table_.Columns[column_n]
    if not column.IsEnabled then
        return
    end
    column.CannotSkipItemsQueue = lshift(1, 0)
    table_.AutoFitSingleColumn = column_n
end

function ImGui.TableSetColumnWidthAutoAll(table_)
    for column_n = 0, table_.ColumnsCount - 1 do
        local column = table_.Columns[column_n]
        if column.IsEnabled or band(column.Flags, ImGuiTableColumnFlags.WidthStretch) ~= 0 then -- Cannot reset weight of hidden stretch column
            column.CannotSkipItemsQueue = lshift(1, 0)
            column.AutoFitQueue = lshift(1, 1)
        end
    end
end

function ImGui.TableUpdateColumnsWeightFromWidth(table_)
    IM_ASSERT(table_.LeftMostStretchedColumn ~= -1 and table_.RightMostStretchedColumn ~= -1)

    -- Measure existing quantities
    local visible_weight = 0.0
    local visible_width = 0.0
    for column_n = 0, table_.ColumnsCount - 1 do
        local column = table_.Columns[column_n]
        if column.IsEnabled and band(column.Flags, ImGuiTableColumnFlags.WidthStretch) ~= 0 then
            IM_ASSERT(column.StretchWeight > 0.0)
            visible_weight = visible_weight + column.StretchWeight
            visible_width = visible_width + column.WidthRequest
        end
    end
    IM_ASSERT(visible_weight > 0.0 and visible_width > 0.0)

    -- Apply new weights
    for column_n = 0, table_.ColumnsCount - 1 do
        local column = table_.Columns[column_n]
        if column.IsEnabled and band(column.Flags, ImGuiTableColumnFlags.WidthStretch) ~= 0 then
            column.StretchWeight = (column.WidthRequest / visible_width) * visible_weight
            IM_ASSERT(column.StretchWeight > 0.0)
        end
    end
end

-------------------------------------------------------------------------------
-- [SECTION] Tables: Drawing
-------------------------------------------------------------------------------
-- - TablePushBackgroundChannel() [Internal]
-- - TablePopBackgroundChannel() [Internal]
-- - TableSetupDrawChannels() [Internal]
-- - TableMergeDrawChannels() [Internal]
-- - TableGetColumnBorderCol() [Internal]
-- - TableDrawBorders() [Internal]
-------------------------------------------------------------------------------


-- FIXME: This could be abstracted and merged with PushColumnsBackground(), by creating a generic struct
-- with storage for backup cliprect + backup channel + storage for splitter pointer, new clip rect.
-- This would slightly simplify caller code.

-- Bg2 is used by Selectable (and possibly other widgets) to render to the background.
-- Unlike our Bg0/1 channel which we uses for RowBg/CellBg/Borders and where we guarantee all shapes to be CPU-clipped, the Bg2 channel being widgets-facing will rely on regular ClipRect.
function ImGui.TablePushBackgroundChannel()
    local g = GImGui
    local window = g.CurrentWindow
    local table_ = g.CurrentTable

    -- Optimization: avoid SetCurrentChannel() + PushClipRect()
    ImRect_Copy(table_.HostBackupInnerClipRect, window.ClipRect)
    ImGui.SetWindowClipRectBeforeSetChannel(window, table_.Bg2ClipRectForDrawCmd)
    table_.DrawSplitter:SetCurrentChannel(window.DrawList, table_.Bg2DrawChannelCurrent)
end

function ImGui.TablePopBackgroundChannel()
    local g = GImGui
    local window = g.CurrentWindow
    local table_ = g.CurrentTable

    -- Optimization: avoid PopClipRect() + SetCurrentChannel()
    ImGui.SetWindowClipRectBeforeSetChannel(window, table_.HostBackupInnerClipRect)
    table_.DrawSplitter:SetCurrentChannel(window.DrawList, table_.Columns[table_.CurrentColumn].DrawChannelCurrent)
end

-- Also see TableBeginCell()
function ImGui.TablePushColumnChannel(column_n)
    local g = GImGui
    local table_ = g.CurrentTable

    -- Optimization: avoid SetCurrentChannel() + PushClipRect()
    if band(table_.Flags, ImGuiTableFlags.NoClip) ~= 0 then
        return
    end
    local window = g.CurrentWindow
    local column = table_.Columns[column_n]
    ImGui.SetWindowClipRectBeforeSetChannel(window, column.ClipRect)
    table_.DrawSplitter:SetCurrentChannel(window.DrawList, column.DrawChannelCurrent)
end

function ImGui.TablePopColumnChannel()
    local g = GImGui
    local table_ = g.CurrentTable

    -- Optimization: avoid PopClipRect() + SetCurrentChannel()
    if band(table_.Flags, ImGuiTableFlags.NoClip) ~= 0 or (table_.CurrentColumn == -1) then -- Calling TreePop() after TableNextRow() is supported.
        return
    end
    local window = g.CurrentWindow
    local column = table_.Columns[table_.CurrentColumn]
    ImGui.SetWindowClipRectBeforeSetChannel(window, column.ClipRect)
    table_.DrawSplitter:SetCurrentChannel(window.DrawList, column.DrawChannelCurrent)
end

-- Allocate draw channels. Called by TableUpdateLayout()
-- - We allocate them following storage order instead of display order so reordering columns won't needlessly
--   increase overall dormant memory cost.
-- - We isolate headers draw commands in their own channels instead of just altering clip rects.
--   This is in order to facilitate merging of draw commands.
-- - After crossing FreezeRowsCount, all columns see their current draw channel changed to a second set of channels.
-- - We only use the dummy draw channel so we can push a null clipping rectangle into it without affecting other
--   channels, while simplifying per-row/per-cell overhead. It will be empty and discarded when merged.
-- - We allocate 1 or 2 background draw channels. This is because we know TablePushBackgroundChannel() is only used for
--   horizontal spanning. If we allowed vertical spanning we'd need one background draw channel per merge group (1-4).
-- Draw channel allocation (before merging):
-- - NoClip                       --> 2+D+1 channels: bg0/1 + bg2 + foreground (same clip rect == always 1 draw call)
-- - Clip                         --> 2+D+N channels
-- - FreezeRows                   --> 2+D+N*2 (unless scrolling value is zero)
-- - FreezeRows || FreezeColumns  --> 3+D+N*2 (unless scrolling value is zero)
-- Where D is 1 if any column is clipped or hidden (dummy channel) otherwise 0.
function ImGui.TableSetupDrawChannels(table_)
    local freeze_row_multiplier = (table_.FreezeRowsCount > 0) and 2 or 1
    local channels_for_row = (band(table_.Flags, ImGuiTableFlags.NoClip) ~= 0) and 1 or table_.ColumnsEnabledCount
    local channels_for_bg = 1 + 1 * freeze_row_multiplier
    local masks_differ = false
    for n = 0, table_.ColumnsCount - 1 do
        if (table_.VisibleMaskByIndex[n] == true) ~= (table_.EnabledMaskByIndex[n] == true) then
            masks_differ = true
            break
        end
    end
    local channels_for_dummy = (table_.ColumnsEnabledCount < table_.ColumnsCount or masks_differ) and 1 or 0
    local channels_total = channels_for_bg + (channels_for_row * freeze_row_multiplier) + channels_for_dummy
    table_.DrawSplitter:Split(table_.InnerWindow.DrawList, channels_total)
    table_.DummyDrawChannel = (channels_for_dummy > 0) and (channels_total - 1) or -1
    table_.Bg2DrawChannelCurrent = TABLE_DRAW_CHANNEL_BG2_FROZEN
    table_.Bg2DrawChannelUnfrozen = (table_.FreezeRowsCount > 0) and (2 + channels_for_row) or TABLE_DRAW_CHANNEL_BG2_FROZEN

    local draw_channel_current = 2
    for column_n = 0, table_.ColumnsCount - 1 do
        local column = table_.Columns[column_n]
        if column.IsVisibleX and column.IsVisibleY then
            column.DrawChannelFrozen = draw_channel_current
            column.DrawChannelUnfrozen = draw_channel_current + ((table_.FreezeRowsCount > 0) and (channels_for_row + 1) or 0)
            if band(table_.Flags, ImGuiTableFlags.NoClip) == 0 then
                draw_channel_current = draw_channel_current + 1
            end
        else
            column.DrawChannelFrozen = table_.DummyDrawChannel
            column.DrawChannelUnfrozen = table_.DummyDrawChannel
        end
        column.DrawChannelCurrent = column.DrawChannelFrozen
    end

    -- Initial draw cmd starts with a BgClipRect that matches the one of its host, to facilitate merge draw commands by default.
    -- All our cell highlight are manually clipped with BgClipRect. When unfreezing it will be made smaller to fit scrolling rect.
    -- (This technically isn't part of setting up draw channels, but is reasonably related to be done here)
    ImRect_Copy(table_.BgClipRect, table_.InnerClipRect)
    ImRect_Copy(table_.Bg0ClipRectForDrawCmd, table_.OuterWindow.ClipRect)
    ImRect_Copy(table_.Bg2ClipRectForDrawCmd, table_.HostClipRect)
    IM_ASSERT(table_.BgClipRect.Min.y <= table_.BgClipRect.Max.y)
end

-- This function reorder draw channels based on matching clip rectangle, to facilitate merging them. Called by EndTable().
-- For simplicity we call it TableMergeDrawChannels() but in fact it only reorder channels + overwrite ClipRect,
-- actual merging is done by table.DrawSplitter:Merge() which is called right after TableMergeDrawChannels().
--
-- Columns where the contents didn't stray off their local clip rectangle can be merged. To achieve
-- this we merge their clip rect and make them contiguous in the channel list, so they can be merged
-- by the call to DrawSplitter:Merge() following to the call to this function.
-- We reorder draw commands by arranging them into a maximum of 4 distinct groups:
--
--   1 group:               2 groups:              2 groups:              4 groups:
--   [ 0. ] no freeze       [ 0. ] row freeze      [ 01 ] col freeze      [ 01 ] row+col freeze
--   [ .. ]  or no scroll   [ 2. ]  and v-scroll   [ .. ]  and h-scroll   [ 23 ]  and v+h-scroll
--
-- Each column itself can use 1 channel (row freeze disabled) or 2 channels (row freeze enabled).
-- When the contents of a column didn't stray off its limit, we move its channels into the corresponding group
-- based on its position (within frozen rows/columns groups or not).
-- At the end of the operation our 1-4 groups will each have a ImDrawCmd using the same ClipRect.
-- This function assume that each column are pointing to a distinct draw channel,
-- otherwise merge_group.ChannelsCount will not match set bit count of merge_group.ChannelsMask.
--
-- Column channels will not be merged into one of the 1-4 groups in the following cases:
-- - The contents stray off its clipping rectangle (we only compare the MaxX value, not the MinX value).
--   Direct ImDrawList calls won't be taken into account by default, if you use them make sure the ImGui.* bounds
--   matches, by e.g. calling SetCursorScreenPos().
-- - The channel uses more than one draw command itself. We drop all our attempt at merging stuff here..
--   we could do better but it's going to be rare and probably not worth the hassle.
-- Columns for which the draw channel(s) haven't been merged with other will use their own ImDrawCmd.
--
-- This function is particularly tricky to understand.. take a breath.
-- (Lua: splitter channel n lives in splitter._Channels.Data[n + 1]; bit arrays are Lua sets)
local TableMergeDrawChannels_MergeGroups = {}
for n = 0, 3 do
    TableMergeDrawChannels_MergeGroups[n] = { ClipRect = ImRect(), ChannelsCount = 0, ChannelsMask = {} }
end
local TableMergeDrawChannels_RemainingMask = {}
local TableMergeDrawChannels_DstTmp = {}
function ImGui.TableMergeDrawChannels(table_)
    local splitter = table_.DrawSplitter
    local channels = splitter._Channels.Data
    local has_freeze_v = (table_.FreezeRowsCount > 0)
    local has_freeze_h = (table_.FreezeColumnsCount > 0)
    IM_ASSERT(splitter._Current == 0)

    -- Track which groups we are going to attempt to merge, and which channels goes into each group.
    local merge_group_mask = 0x00
    -- [Luau] reuse file-level scratch storage (function is not re-entrant, nothing escapes)
    local merge_groups = TableMergeDrawChannels_MergeGroups
    for n = 0, 3 do
        local merge_group = merge_groups[n]
        local cr = merge_group.ClipRect
        cr.Min.x = 0.0; cr.Min.y = 0.0; cr.Max.x = 0.0; cr.Max.y = 0.0
        merge_group.ChannelsCount = 0
        table.clear(merge_group.ChannelsMask)
    end
    local max_draw_channels = (4 + table_.ColumnsCount * 2)
    local remaining_mask = TableMergeDrawChannels_RemainingMask
    table.clear(remaining_mask)

    -- 1. Scan channels and take note of those which can be merged
    for column_n = 0, table_.ColumnsCount - 1 do
        if BitTest(table_.VisibleMaskByIndex, column_n) then
            local column = table_.Columns[column_n]

            local merge_group_sub_count = has_freeze_v and 2 or 1
            for merge_group_sub_n = 0, merge_group_sub_count - 1 do
                repeat
                    local channel_no = (merge_group_sub_n == 0) and column.DrawChannelFrozen or column.DrawChannelUnfrozen

                    -- Don't attempt to merge if there are multiple draw calls within the column
                    local src_channel = channels[channel_no + 1]
                    local cmds = src_channel._CmdBuffer
                    if cmds.Size > 0 and cmds.Data[cmds.Size].ElemCount == 0 and cmds.Data[cmds.Size].UserCallback == nil then -- Equivalent of PopUnusedDrawCmd()
                        cmds:pop_back()
                    end
                    if cmds.Size ~= 1 then
                        break
                    end

                    -- Find out the width of this merge group and check if it will fit in our column
                    -- (note that we assume that rendering didn't stray on the left direction. we should need a CursorMinPos to detect it)
                    if band(column.Flags, ImGuiTableColumnFlags.NoClip) == 0 then
                        local content_max_x
                        if not has_freeze_v then
                            content_max_x = mathMax(column.ContentMaxXUnfrozen, column.ContentMaxXHeadersUsed) -- No row freeze
                        elseif merge_group_sub_n == 0 then
                            content_max_x = mathMax(column.ContentMaxXFrozen, column.ContentMaxXHeadersUsed)   -- Row freeze: use width before freeze
                        else
                            content_max_x = column.ContentMaxXUnfrozen                                        -- Row freeze: use width after freeze
                        end
                        if content_max_x > column.ClipRect.Max.x then
                            break
                        end
                    end

                    local merge_group_n = ((has_freeze_h and column_n < table_.FreezeColumnsCount) and 0 or 1) + ((has_freeze_v and merge_group_sub_n == 0) and 0 or 2)
                    IM_ASSERT(channel_no < max_draw_channels)
                    local merge_group = merge_groups[merge_group_n]
                    if merge_group.ChannelsCount == 0 then
                        local gcr = merge_group.ClipRect -- [Luau] in place (merge_groups are local to this call)
                        gcr.Min.x = FLT_MAX; gcr.Min.y = FLT_MAX; gcr.Max.x = -FLT_MAX; gcr.Max.y = -FLT_MAX
                    end
                    merge_group.ChannelsMask[channel_no] = true
                    merge_group.ChannelsCount = merge_group.ChannelsCount + 1
                    local cr = cmds.Data[1].ClipRect
                    -- [Luau] scalar version of merge_group.ClipRect:Add(ImRect(cr.x, cr.y, cr.z, cr.w))
                    local gmin, gmax = merge_group.ClipRect.Min, merge_group.ClipRect.Max
                    if gmin.x > cr.x then gmin.x = cr.x end
                    if gmin.y > cr.y then gmin.y = cr.y end
                    if gmax.x < cr.z then gmax.x = cr.z end
                    if gmax.y < cr.w then gmax.y = cr.w end
                    merge_group_mask = bor(merge_group_mask, lshift(1, merge_group_n))
                until true
            end

            -- Invalidate current draw channel
            -- (we don't clear DrawChannelFrozen/DrawChannelUnfrozen solely to facilitate debugging/later inspection of data)
            column.DrawChannelCurrent = -1
        end
    end

    -- 2. Rewrite channel list in our preferred order
    if merge_group_mask ~= 0 then
        -- We skip channel 0 (Bg0/Bg1) and 1 (Bg2 frozen) from the shuffling since they won't move - see channels allocation in TableSetupDrawChannels().
        local LEADING_DRAW_CHANNELS = 2
        local dst_tmp = TableMergeDrawChannels_DstTmp -- [Luau] scratch
        table.clear(dst_tmp)
        for n = LEADING_DRAW_CHANNELS, splitter._Count - 1 do
            remaining_mask[n] = true
        end
        remaining_mask[table_.Bg2DrawChannelUnfrozen] = nil
        IM_ASSERT(has_freeze_v == false or table_.Bg2DrawChannelUnfrozen ~= TABLE_DRAW_CHANNEL_BG2_FROZEN)
        local remaining_count = splitter._Count - (has_freeze_v and (LEADING_DRAW_CHANNELS + 1) or LEADING_DRAW_CHANNELS)
        --local host_rect = (table.InnerWindow == table.OuterWindow) and table.InnerClipRect or table.HostClipRect
        local host_rect = table_.HostClipRect
        for merge_group_n = 0, 3 do
            local merge_channels_count = merge_groups[merge_group_n].ChannelsCount
            if merge_channels_count ~= 0 then
                local merge_group = merge_groups[merge_group_n]
                local merge_clip_rect = Rect(merge_group.ClipRect)

                -- Extend outer-most clip limits to match those of host, so draw calls can be merged even if
                -- outer-most columns have some outer padding offsetting them from their parent ClipRect.
                -- The principal cases this is dealing with are:
                -- - On a same-window table (not scrolling = single group), all fitting columns ClipRect -> will extend and match host ClipRect -> will merge
                -- - Columns can use padding and have left-most ClipRect.Min.x and right-most ClipRect.Max.x != from host ClipRect -> will extend and match host ClipRect -> will merge
                -- FIXME-TABLE FIXME-WORKRECT: We are wasting a merge opportunity on tables without scrolling if column doesn't fit
                -- within host clip rect, solely because of the half-padding difference between window.WorkRect and window.InnerClipRect.
                if band(merge_group_n, 1) == 0 or not has_freeze_h then
                    merge_clip_rect.Min.x = mathMin(merge_clip_rect.Min.x, host_rect.Min.x)
                end
                if band(merge_group_n, 2) == 0 or not has_freeze_v then
                    merge_clip_rect.Min.y = mathMin(merge_clip_rect.Min.y, host_rect.Min.y)
                end
                if band(merge_group_n, 1) ~= 0 then
                    merge_clip_rect.Max.x = mathMax(merge_clip_rect.Max.x, host_rect.Max.x)
                end
                if band(merge_group_n, 2) ~= 0 and band(table_.Flags, ImGuiTableFlags.NoHostExtendY) == 0 then
                    merge_clip_rect.Max.y = mathMax(merge_clip_rect.Max.y, host_rect.Max.y)
                end
                --ImGui.GetForegroundDrawList():AddRect(merge_group.ClipRect.Min, merge_group.ClipRect.Max, IM_COL32(255, 0, 0, 200), 0.0, 0, 1.0) -- [DEBUG]
                --ImGui.GetForegroundDrawList():AddLine(merge_group.ClipRect.Min, merge_clip_rect.Min, IM_COL32(255, 100, 0, 200))
                --ImGui.GetForegroundDrawList():AddLine(merge_group.ClipRect.Max, merge_clip_rect.Max, IM_COL32(255, 100, 0, 200))
                remaining_count = remaining_count - merge_group.ChannelsCount
                for n in pairs(merge_group.ChannelsMask) do
                    remaining_mask[n] = nil
                end
                local n = 0
                while n < splitter._Count and merge_channels_count ~= 0 do
                    -- Copy + overwrite new clip rect
                    if merge_group.ChannelsMask[n] then
                        merge_group.ChannelsMask[n] = nil
                        merge_channels_count = merge_channels_count - 1

                        local channel = channels[n + 1]
                        IM_ASSERT(channel._CmdBuffer.Size == 1)
                        local dst = channel._CmdBuffer.Data[1].ClipRect -- [Luau] scalar copy, no temporary ImVec4
                        dst.x = merge_clip_rect.Min.x; dst.y = merge_clip_rect.Min.y; dst.z = merge_clip_rect.Max.x; dst.w = merge_clip_rect.Max.y
                        dst_tmp[#dst_tmp + 1] = channel
                    end
                    n = n + 1
                end
            end

            -- Make sure Bg2DrawChannelUnfrozen appears in the middle of our groups (whereas Bg0/Bg1 and Bg2 frozen are fixed to 0 and 1)
            if merge_group_n == 1 and has_freeze_v then
                dst_tmp[#dst_tmp + 1] = channels[table_.Bg2DrawChannelUnfrozen + 1]
            end
        end

        -- Append unmergeable channels that we didn't reorder at the end of the list
        local n = 0
        while n < splitter._Count and remaining_count ~= 0 do
            if remaining_mask[n] then
                dst_tmp[#dst_tmp + 1] = channels[n + 1]
                remaining_count = remaining_count - 1
            end
            n = n + 1
        end
        IM_ASSERT(#dst_tmp == splitter._Count - LEADING_DRAW_CHANNELS)
        for i = 1, #dst_tmp do
            channels[LEADING_DRAW_CHANNELS + i] = dst_tmp[i]
        end
        table.clear(dst_tmp) -- [Luau] don't keep channel references alive in the scratch
    end
end

local function TableGetColumnBorderCol(table_, order_n, column_n)
    local is_hovered = (table_.HoveredColumnBorder == column_n)
    local is_resized = (table_.ResizedColumn == column_n) and (table_.InstanceInteracted == table_.InstanceCurrent)
    local is_frozen_separator = (table_.FreezeColumnsCount == order_n + 1)
    if is_resized or is_hovered then
        return ImGui.GetColorU32(is_resized and ImGuiCol.SeparatorActive or ImGuiCol.SeparatorHovered)
    end
    if is_frozen_separator or band(table_.Flags, bor(ImGuiTableFlags.NoBordersInBody, ImGuiTableFlags.NoBordersInBodyUntilResize)) ~= 0 then
        return table_.BorderColorStrong
    end
    return table_.BorderColorLight
end

-- FIXME-TABLE: This is a mess, need to redesign how we render borders (as some are also done in TableEndRow)
function ImGui.TableDrawBorders(table_)
    local inner_window = table_.InnerWindow
    if not table_.OuterWindow.ClipRect:Overlaps(table_.OuterRect) then
        return
    end

    local inner_drawlist = inner_window.DrawList
    table_.DrawSplitter:SetCurrentChannel(inner_drawlist, TABLE_DRAW_CHANNEL_BG0)
    inner_drawlist:PushClipRect(table_.Bg0ClipRectForDrawCmd.Min, table_.Bg0ClipRectForDrawCmd.Max, false)

    -- Draw inner border and resizing feedback
    local table_instance = ImGui.TableGetInstanceData(table_, table_.InstanceCurrent)
    local border_size = TABLE_BORDER_SIZE
    local draw_y1 = mathMax(table_.InnerRect.Min.y, ((table_.FreezeRowsCount >= 1) and table_.InnerRect.Min.y or table_.WorkRect.Min.y) + table_.AngledHeadersHeight) + ((band(table_.Flags, ImGuiTableFlags.BordersOuterH) ~= 0) and border_size or 0.0)
    local draw_y2_body = table_.InnerRect.Max.y
    local draw_y2_head = table_.IsUsingHeaders and mathMin(table_.InnerRect.Max.y, ((table_.FreezeRowsCount >= 1) and table_.InnerRect.Min.y or table_.WorkRect.Min.y) + table_instance.LastTopHeadersRowHeight) or draw_y1
    if band(table_.Flags, ImGuiTableFlags.BordersInnerV) ~= 0 then
        for order_n = 0, table_.ColumnsCount - 1 do
            repeat
                if not BitTest(table_.EnabledMaskByDisplayOrder, order_n) then
                    break
                end

                local column_n = table_.DisplayOrderToIndex[order_n]
                local column = table_.Columns[column_n]
                local is_hovered = (table_.HoveredColumnBorder == column_n)
                local is_resized = (table_.ResizedColumn == column_n) and (table_.InstanceInteracted == table_.InstanceCurrent)
                local is_resizable = band(column.Flags, bor(ImGuiTableColumnFlags.NoResize, ImGuiTableColumnFlags.NoDirectResize_)) == 0
                local is_frozen_separator = (table_.FreezeColumnsCount == order_n + 1)
                if column.MaxX > table_.InnerClipRect.Max.x and not is_resized then
                    break
                end

                -- Decide whether right-most column is visible
                if column.NextEnabledColumn == -1 and not is_resizable then
                    if band(table_.Flags, ImGuiTableFlags.SizingMask_) ~= ImGuiTableFlags.SizingFixedSame or band(table_.Flags, ImGuiTableFlags.NoHostExtendX) ~= 0 then
                        break
                    end
                end
                if column.MaxX <= column.ClipRect.Min.x then -- FIXME-TABLE FIXME-STYLE: Assume BorderSize==1, this is problematic if we want to increase the border size..
                    break
                end

                -- Draw in outer window so right-most column won't be clipped
                local draw_y2 = draw_y2_head
                if is_frozen_separator then
                    draw_y2 = draw_y2_body
                elseif band(table_.Flags, ImGuiTableFlags.NoBordersInBodyUntilResize) ~= 0 and (is_hovered or is_resized) then
                    draw_y2 = draw_y2_body
                elseif band(table_.Flags, bor(ImGuiTableFlags.NoBordersInBodyUntilResize, ImGuiTableFlags.NoBordersInBody)) == 0 then
                    draw_y2 = draw_y2_body
                end
                if draw_y2 > draw_y1 then
                    inner_drawlist:AddLineV(column.MaxX, draw_y1, draw_y2, TableGetColumnBorderCol(table_, order_n, column_n), border_size)
                end
            until true
        end
    end

    -- Draw outer border
    -- FIXME: could use AddRect or explicit VLine/HLine helper?
    if band(table_.Flags, ImGuiTableFlags.BordersOuter) ~= 0 then
        -- Display outer border offset by 1 which is a simple way to display it without adding an extra draw call
        -- (Without the offset, in outer_window it would be rendered behind cells, because child windows are above their
        -- parent. In inner_window, it won't reach out over scrollbars. Another weird solution would be to display part
        -- of it in inner window, and the part that's over scrollbars in the outer window..)
        -- Either solution currently won't allow us to use a larger border size: the border would clipped.
        local outer_border = table_.OuterRect
        local outer_col = table_.BorderColorStrong
        if band(table_.Flags, ImGuiTableFlags.BordersOuter) == ImGuiTableFlags.BordersOuter then
            inner_drawlist:AddRect(outer_border.Min, outer_border.Max, outer_col, 0.0, border_size)
        elseif band(table_.Flags, ImGuiTableFlags.BordersOuterV) ~= 0 then
            inner_drawlist:AddLineV(outer_border.Min.x, outer_border.Min.y, outer_border.Max.y, outer_col, border_size)
            inner_drawlist:AddLineV(outer_border.Max.x - border_size, outer_border.Min.y, outer_border.Max.y, outer_col, border_size)
        elseif band(table_.Flags, ImGuiTableFlags.BordersOuterH) ~= 0 then
            inner_drawlist:AddLineH(outer_border.Min.x, outer_border.Max.x, outer_border.Min.y, outer_col, border_size)
            inner_drawlist:AddLineH(outer_border.Min.x, outer_border.Max.x, outer_border.Max.y - border_size, outer_col, border_size)
        end
    end
    if band(table_.Flags, ImGuiTableFlags.BordersInnerH) ~= 0 and table_.RowPosY2 < table_.OuterRect.Max.y then
        -- Draw bottom-most row border between it is above outer border.
        local h_inset = (band(table_.Flags, ImGuiTableFlags.BordersOuterV) ~= 0) and border_size or 0.0
        local border_y = table_.RowPosY2
        if border_y >= table_.BgClipRect.Min.y and border_y < table_.BgClipRect.Max.y then
            inner_drawlist:AddLineH(table_.BorderX1 + h_inset, table_.BorderX2 - h_inset, border_y, table_.BorderColorLight, border_size)
        end
    end

    inner_drawlist:PopClipRect()
end

-------------------------------------------------------------------------------
-- [SECTION] Tables: Sorting
-------------------------------------------------------------------------------
-- - TableGetSortSpecs()
-- - TableFixColumnSortDirection() [Internal]
-- - TableGetColumnNextSortDirection() [Internal]
-- - TableSetColumnSortDirection() [Internal]
-- - TableSortSpecsSanitize() [Internal]
-- - TableSortSpecsBuild() [Internal]
-------------------------------------------------------------------------------

-- Return nil if no sort specs (most often when ImGuiTableFlags.Sortable is not set)
-- When 'sort_specs.SpecsDirty == true' you should sort your data. It will be true when sorting specs have
-- changed since last call, or the first time. Make sure to set 'SpecsDirty = false' after sorting,
-- else you may wastefully sort your data every frame!
-- Lifetime: don't hold on this table over multiple frames or past any subsequent call to BeginTable()!
-- PORT: Specs is a 1-based Lua array.
function ImGui.TableGetSortSpecs()
    local g = GImGui
    local table_ = g.CurrentTable
    if table_ == nil or band(table_.Flags, ImGuiTableFlags.Sortable) == 0 then
        return nil
    end

    -- Require layout (in case TableHeadersRow() hasn't been called) as it may alter IsSortSpecsDirty in some paths.
    if not table_.IsLayoutLocked then
        ImGui.TableUpdateLayout(table_)
    end

    ImGui.TableSortSpecsBuild(table_)
    return table_.SortSpecs
end

local function TableGetColumnAvailSortDirection(column, n)
    IM_ASSERT(n < column.SortDirectionsAvailCount)
    return band(rshift(column.SortDirectionsAvailList, lshift(n, 1)), 0x03)
end

-- Fix sort direction if currently set on a value which is unavailable (e.g. activating NoSortAscending/NoSortDescending)
function ImGui.TableFixColumnSortDirection(table_, column)
    if column.SortOrder == -1 or band(column.SortDirectionsAvailMask, lshift(1, column.SortDirection)) ~= 0 then
        return
    end
    column.SortDirection = TableGetColumnAvailSortDirection(column, 0)
    table_.IsSortSpecsDirty = true
end

-- Calculate next sort direction that would be set after clicking the column
-- - If the PreferSortDescending flag is set, we will default to a Descending direction on the first click.
-- - Note that the PreferSortAscending flag is never checked, it is essentially the default and therefore a no-op.
function ImGui.TableGetColumnNextSortDirection(column)
    IM_ASSERT(column.SortDirectionsAvailCount > 0)
    if column.SortOrder == -1 then
        return TableGetColumnAvailSortDirection(column, 0)
    end
    for n = 0, 2 do
        if column.SortDirection == TableGetColumnAvailSortDirection(column, n) then
            return TableGetColumnAvailSortDirection(column, (n + 1) % column.SortDirectionsAvailCount)
        end
    end
    IM_ASSERT(false)
    return ImGuiSortDirection.None
end

-- Note that the NoSortAscending/NoSortDescending flags are processed in TableSortSpecsSanitize(), and they may change/revert
-- the value of SortDirection. We could technically also do it here but it would be unnecessary and duplicate code.
function ImGui.TableSetColumnSortDirection(column_n, sort_direction, append_to_sort_specs)
    local g = GImGui
    local table_ = g.CurrentTable

    if band(table_.Flags, ImGuiTableFlags.SortMulti) == 0 then
        append_to_sort_specs = false
    end
    if band(table_.Flags, ImGuiTableFlags.SortTristate) == 0 then
        IM_ASSERT(sort_direction ~= ImGuiSortDirection.None)
    end

    local sort_order_max = 0
    if append_to_sort_specs then
        for other_column_n = 0, table_.ColumnsCount - 1 do
            sort_order_max = mathMax(sort_order_max, table_.Columns[other_column_n].SortOrder)
        end
    end

    local column = table_.Columns[column_n]
    column.SortDirection = sort_direction
    if column.SortDirection == ImGuiSortDirection.None then
        column.SortOrder = -1
    elseif column.SortOrder == -1 or not append_to_sort_specs then
        column.SortOrder = append_to_sort_specs and (sort_order_max + 1) or 0
    end

    for other_column_n = 0, table_.ColumnsCount - 1 do
        local other_column = table_.Columns[other_column_n]
        if other_column ~= column and not append_to_sort_specs then
            other_column.SortOrder = -1
        end
        ImGui.TableFixColumnSortDirection(table_, other_column)
    end
    table_.IsSettingsDirty = true
    table_.IsSortSpecsDirty = true
end

function ImGui.TableSortSpecsSanitize(table_)
    IM_ASSERT(band(table_.Flags, ImGuiTableFlags.Sortable) ~= 0)

    -- Clear SortOrder from hidden column and verify that there's no gap or duplicate.
    local sort_order_count = 0
    local sort_order_set = {} -- C++: ImU64 sort_order_mask
    local sort_order_dup = false
    for column_n = 0, table_.ColumnsCount - 1 do
        local column = table_.Columns[column_n]
        if column.SortOrder ~= -1 and not column.IsEnabled then
            column.SortOrder = -1
        end
        if column.SortOrder ~= -1 then
            sort_order_count = sort_order_count + 1
            if sort_order_set[column.SortOrder] then sort_order_dup = true end
            sort_order_set[column.SortOrder] = true
            IM_ASSERT(sort_order_count < 64)
        end
    end

    -- need_fix_linearize: (1 << count) != (mask + 1) <=> the set of sort orders isn't exactly {0..count-1}
    local need_fix_linearize = sort_order_dup
    for n = 0, sort_order_count - 1 do
        if not sort_order_set[n] then need_fix_linearize = true end
    end
    local need_fix_single_sort_order = (sort_order_count > 1) and band(table_.Flags, ImGuiTableFlags.SortMulti) == 0
    if need_fix_linearize or need_fix_single_sort_order then
        local fixed_mask = {}
        for sort_n = 0, sort_order_count - 1 do
            -- Fix: Rewrite sort order fields if needed so they have no gap or duplicate.
            -- (e.g. SortOrder 0 disappeared, SortOrder 1..2 exists --> rewrite then as SortOrder 0..1)
            local column_with_smallest_sort_order = -1
            for column_n = 0, table_.ColumnsCount - 1 do
                if not fixed_mask[column_n] and table_.Columns[column_n].SortOrder ~= -1 then
                    if column_with_smallest_sort_order == -1 or table_.Columns[column_n].SortOrder < table_.Columns[column_with_smallest_sort_order].SortOrder then
                        column_with_smallest_sort_order = column_n
                    end
                end
            end
            IM_ASSERT(column_with_smallest_sort_order ~= -1)
            fixed_mask[column_with_smallest_sort_order] = true
            table_.Columns[column_with_smallest_sort_order].SortOrder = sort_n

            -- Fix: Make sure only one column has a SortOrder if ImGuiTableFlags.MultiSortable is not set.
            if need_fix_single_sort_order then
                sort_order_count = 1
                for column_n = 0, table_.ColumnsCount - 1 do
                    if column_n ~= column_with_smallest_sort_order then
                        table_.Columns[column_n].SortOrder = -1
                    end
                end
                break
            end
        end
    end

    -- Fallback default sort order (if no column with the ImGuiTableColumnFlags.DefaultSort flag)
    if sort_order_count == 0 and band(table_.Flags, ImGuiTableFlags.SortTristate) == 0 then
        for column_n = 0, table_.ColumnsCount - 1 do
            local column = table_.Columns[column_n]
            if column.IsEnabled and band(column.Flags, ImGuiTableColumnFlags.NoSort) == 0 then
                sort_order_count = 1
                column.SortOrder = 0
                column.SortDirection = TableGetColumnAvailSortDirection(column, 0)
                break
            end
        end
    end

    table_.SortSpecsCount = sort_order_count
end

function ImGui.TableSortSpecsBuild(table_)
    local dirty = table_.IsSortSpecsDirty
    if dirty then
        ImGui.TableSortSpecsSanitize(table_)
        local multi = table_.SortSpecsMulti
        local want = (table_.SortSpecsCount <= 1) and 0 or table_.SortSpecsCount
        for n = #multi + 1, want do multi[n] = ImGuiTableColumnSortSpecs() end
        for n = #multi, want + 1, -1 do multi[n] = nil end
        table_.SortSpecs.SpecsDirty = true -- Mark as dirty for user
        table_.IsSortSpecsDirty = false -- Mark as not dirty for us
    end

    -- Write output
    -- May be able to move all SortSpecs data from table (48 bytes) to ImGuiTableTempData if we decide to write it back on every BeginTable()
    local sort_specs
    if table_.SortSpecsCount == 0 then
        sort_specs = nil
    elseif table_.SortSpecsCount == 1 then
        table_.SortSpecsSingleArray = table_.SortSpecsSingleArray or { table_.SortSpecsSingle }
        sort_specs = table_.SortSpecsSingleArray
    else
        sort_specs = table_.SortSpecsMulti
    end
    if dirty and sort_specs ~= nil then
        for column_n = 0, table_.ColumnsCount - 1 do
            local column = table_.Columns[column_n]
            if column.SortOrder ~= -1 then
                IM_ASSERT(column.SortOrder < table_.SortSpecsCount)
                local sort_spec = sort_specs[column.SortOrder + 1]
                sort_spec.ColumnUserID = column.UserData
                sort_spec.ColumnIndex = column_n
                sort_spec.SortOrder = column.SortOrder
                sort_spec.SortDirection = column.SortDirection
            end
        end
    end

    table_.SortSpecs.Specs = sort_specs
    table_.SortSpecs.SpecsCount = table_.SortSpecsCount
end

-------------------------------------------------------------------------------
-- [SECTION] Tables: Headers
-------------------------------------------------------------------------------
-- - TableGetHeaderRowHeight() [Internal]
-- - TableGetHeaderAngledMaxLabelWidth() [Internal]
-- - TableHeadersRow()
-- - TableHeader()
-- - TableAngledHeadersRow()
-- - TableAngledHeadersRowEx() [Internal]
-------------------------------------------------------------------------------

function ImGui.TableGetHeaderRowHeight()
    -- Caring for a minor edge case:
    -- Calculate row height, for the unlikely case that some labels may be taller than others.
    -- If we didn't do that, uneven header height would highlight but smaller one before the tallest wouldn't catch input for all height.
    -- In your custom header row you may omit this all together and just call TableNextRow() without a height...
    local g = GImGui
    local table_ = g.CurrentTable
    local row_height = g.FontSize
    for column_n = 0, table_.ColumnsCount - 1 do
        if BitTest(table_.EnabledMaskByIndex, column_n) then
            if band(table_.Columns[column_n].Flags, ImGuiTableColumnFlags.NoHeaderLabel) == 0 then
                row_height = mathMax(row_height, ImGui.CalcTextSize(ImGui.TableGetColumnName(table_, column_n)).y)
            end
        end
    end
    return row_height + g.Style.CellPadding.y * 2.0
end

function ImGui.TableGetHeaderAngledMaxLabelWidth()
    local g = GImGui
    local table_ = g.CurrentTable
    local width = 0.0
    for column_n = 0, table_.ColumnsCount - 1 do
        if BitTest(table_.EnabledMaskByIndex, column_n) then
            if band(table_.Columns[column_n].Flags, ImGuiTableColumnFlags.AngledHeader) ~= 0 then
                width = mathMax(width, ImGui.CalcTextSize(ImGui.TableGetColumnName(table_, column_n), nil, true).x)
            end
        end
    end
    return width + g.Style.CellPadding.y * 2.0 -- Swap padding
end

-- [Public] This is a helper to output TableHeader() calls based on the column names declared in TableSetupColumn().
-- The intent is that advanced users willing to create customized headers would not need to use this helper
-- and can create their own! For example: TableHeader() may be preceded by Checkbox() or other custom widgets.
-- See 'Demo->Tables->Custom headers' for a demonstration of implementing a custom version of this.
-- This code is intentionally written to not make much use of internal functions, to give you better direction
-- if you need to write your own.
-- FIXME-TABLE: TableOpenContextMenu() and TableGetHeaderRowHeight() are not public.
function ImGui.TableHeadersRow()
    local g = GImGui
    local table_ = g.CurrentTable
    IM_ASSERT_USER_ERROR_RET(table_ ~= nil, "Call should only be done while in BeginTable() scope!")

    -- Call layout if not already done. This is automatically done by TableNextRow: we do it here _only_ to make
    -- it easier to debug-step in TableUpdateLayout(). Your own version of this function doesn't need this.
    if not table_.IsLayoutLocked then
        ImGui.TableUpdateLayout(table_)
    end

    -- Open row
    local row_height = ImGui.TableGetHeaderRowHeight()
    ImGui.TableNextRow(ImGuiTableRowFlags.Headers, row_height)
    local row_y1 = ImGui.GetCursorScreenPos().y
    if table_.HostSkipItems then -- Merely an optimization, you may skip in your own code.
        return
    end

    local columns_count = ImGui.TableGetColumnCount()
    for column_n = 0, columns_count - 1 do
        if ImGui.TableSetColumnIndex(column_n) or table_.LastHeldHeaderColumn == column_n then
            -- Push an id to allow empty/unnamed headers. This is also idiomatic as it ensure there is a consistent ID path to access columns (for e.g. automation)
            local name = (band(ImGui.TableGetColumnFlags(column_n), ImGuiTableColumnFlags.NoHeaderLabel) ~= 0) and "" or ImGui.TableGetColumnName(column_n)
            ImGui.PushID(column_n)
            ImGui.TableHeader(name)
            ImGui.PopID()
        end
    end

    -- Allow opening popup from the right-most section after the last column.
    local mouse_pos = ImGui.GetMousePos()
    if ImGui.IsMouseReleased(1) and ImGui.TableGetHoveredColumn() == columns_count then
        if mouse_pos.y >= row_y1 and mouse_pos.y < row_y1 + row_height then
            ImGui.TableOpenContextMenu(columns_count) -- Will open a non-column-specific popup.
        end
    end
end

-- Emit a column header (text + optional sort order)
-- We cpu-clip text here so that all columns headers can be merged into a same draw call.
-- Note that because of how we cpu-clip and display sorting indicators, you _cannot_ use SameLine() after a TableHeader()
function ImGui.TableHeader(label)
    local g = GImGui
    local window = g.CurrentWindow
    if window.SkipItems then
        return
    end

    local table_ = g.CurrentTable
    IM_ASSERT_USER_ERROR_RET(table_ ~= nil, "Call should only be done while in BeginTable() scope!")
    IM_ASSERT(table_.CurrentColumn ~= -1)
    local column_n = table_.CurrentColumn
    local column = table_.Columns[column_n]

    -- Label
    if label == nil then
        label = ""
    end
    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)
    local label_pos = V2(window.DC.CursorPos)

    -- If we already got a row height, there's use that.
    -- FIXME-TABLE: Padding problem if the correct outer-padding CellBgRect strays off our ClipRect?
    -- [Luau] scalar version of: cell_r = TableGetCellBgRect(table_, column_n) (Min.x/Min.y/Max.x/Max.y -> cell_x1/cell_y1/cell_x2/cell_y2)
    local cell_x1 = mathMax(column.MinX, table_.WorkRect.Min.x)
    local cell_x2 = mathMin(column.MaxX, table_.WorkRect.Max.x)
    local cell_y1, cell_y2 = table_.RowPosY1, table_.RowPosY2
    local label_height = mathMax(label_size.y, table_.RowMinHeight - table_.RowCellPaddingY * 2.0)

    -- Calculate ideal size for sort order arrow
    local w_arrow = 0.0
    local w_sort_text = 0.0
    local sort_arrow = false
    local sort_order_suf = ""
    local ARROW_SCALE = 0.65
    if band(table_.Flags, ImGuiTableFlags.Sortable) ~= 0 and band(column.Flags, ImGuiTableColumnFlags.NoSort) == 0 then
        w_arrow = ImTrunc(g.FontSize * ARROW_SCALE + g.Style.FramePadding.x)
        if column.SortOrder ~= -1 then
            sort_arrow = true
        end
        if column.SortOrder > 0 then
            sort_order_suf = string.format("%d", column.SortOrder + 1)
            w_sort_text = g.Style.ItemInnerSpacing.x + ImGui.CalcTextSize(sort_order_suf).x
        end
    end

    -- We feed our unclipped width to the column without writing on CursorMaxPos, so that column is still considered for merging.
    local max_pos_x = label_pos.x + label_size.x + w_sort_text + w_arrow
    column.ContentMaxXHeadersUsed = mathMax(column.ContentMaxXHeadersUsed, sort_arrow and cell_x2 or mathMin(max_pos_x, cell_x2))
    column.ContentMaxXHeadersIdeal = mathMax(column.ContentMaxXHeadersIdeal, max_pos_x)

    -- Keep header highlighted when context menu is open.
    local id = window:GetID(label)
    local bb = ImRect(cell_x1, cell_y1, cell_x2, mathMax(cell_y2, cell_y1 + label_height + g.Style.CellPadding.y * 2.0))
    ImGui.ItemSize(ImVec2(0.0, label_height)) -- Don't declare unclipped width, it'll be fed ContentMaxPosHeadersIdeal
    if not ImGui.ItemAdd(bb, id) then
        return
    end

    --GetForegroundDrawList():AddRect(cell_r.Min, cell_r.Max, IM_COL32(255, 0, 0, 255)) -- [DEBUG]
    --GetForegroundDrawList():AddRect(bb.Min, bb.Max, IM_COL32(255, 0, 0, 255)) -- [DEBUG]

    -- Using AllowOverlap mode because we cover the whole cell, and we want user to be able to submit subsequent items.
    local highlight = (table_.HighlightColumnHeader == column_n)
    local pressed, hovered, held = ImGui.ButtonBehavior(bb, id, ImGuiButtonFlags.AllowOverlap)
    if held or hovered or highlight then
        local col = ImGui.GetColorU32(held and ImGuiCol.HeaderActive or (hovered and ImGuiCol.HeaderHovered or ImGuiCol.Header))
        --RenderFrame(bb.Min, bb.Max, col, false, 0.0)
        ImGui.TableSetBgColor(ImGuiTableBgTarget.CellBg, col, table_.CurrentColumn)
    else
        -- Submit single cell bg color in the case we didn't submit a full header row
        if band(table_.RowFlags, ImGuiTableRowFlags.Headers) == 0 then
            ImGui.TableSetBgColor(ImGuiTableBgTarget.CellBg, ImGui.GetColorU32(ImGuiCol.TableHeaderBg), table_.CurrentColumn)
        end
    end
    ImGui.RenderNavCursor(bb, id, ImGuiNavRenderCursorFlags.Compact, 0.0)
    if held then
        table_.HeldHeaderColumn = column_n
    end
    window.DC.CursorPos.y = window.DC.CursorPos.y - g.Style.ItemSpacing.y * 0.5

    -- Drag and drop to re-order columns.
    -- FIXME-TABLE: Scroll request while reordering a column and it lands out of the scrolling zone.
    if held and band(table_.Flags, ImGuiTableFlags.Reorderable) ~= 0 and ImGui.IsMouseDragging(0) and not g.DragDropActive then
        -- - While moving a column it will jump on the other side of the mouse, so we also test for MouseDelta.x
        -- - We need to handle reordering across hidden columns.
        --   In the configuration below, moving C to the right of E will lead to:
        --      ... C [D] E  --->  ... [D] E  C   (Column name/index)
        --      ... 2  3  4        ...  2  3  4   (Display order)
        -- - The other constraints are enforced by TableQueueSetColumnDisplayOrder() which might early out.
        table_.InstanceInteracted = table_.InstanceCurrent
        if g.IO.MouseDelta.x < 0.0 and g.IO.MousePos.x < cell_x1 then
            local prev_column = (column.PrevEnabledColumn ~= -1) and table_.Columns[column.PrevEnabledColumn] or nil
            if prev_column then
                ImGui.TableQueueSetColumnDisplayOrder(table_, column_n, prev_column.DisplayOrder)
            end
        end
        if g.IO.MouseDelta.x > 0.0 and g.IO.MousePos.x > cell_x2 then
            local next_column = (column.NextEnabledColumn ~= -1) and table_.Columns[column.NextEnabledColumn] or nil
            if next_column then
                ImGui.TableQueueSetColumnDisplayOrder(table_, column_n, next_column.DisplayOrder)
            end
        end
    end

    -- Sort order arrow
    -- - Only clip label for a visible arrow. Auto-fit still accounts for a possible arrow, but when
    --   manually sized smaller we don't clip the label for the sake of an arrow that isn't displayed.
    local ellipsis_max = mathMax(cell_x2 - (sort_arrow and (w_arrow + w_sort_text) or 0.0), label_pos.x)
    if band(table_.Flags, ImGuiTableFlags.Sortable) ~= 0 and band(column.Flags, ImGuiTableColumnFlags.NoSort) == 0 then
        if column.SortOrder ~= -1 then
            local x = mathMax(cell_x1, cell_x2 - w_arrow - w_sort_text)
            local y = label_pos.y
            if column.SortOrder > 0 then
                ImGui.PushStyleColor(ImGuiCol.Text, ImGui.GetColorU32(ImGuiCol.Text, 0.70))
                ImGui.RenderText(ImVec2(x + g.Style.ItemInnerSpacing.x, y), sort_order_suf)
                ImGui.PopStyleColor()
                x = x + w_sort_text
            end
            ImGui.RenderArrow(window.DrawList, ImVec2(x, y), ImGui.GetColorU32(ImGuiCol.Text), (column.SortDirection == ImGuiSortDirection.Ascending) and ImGuiDir.Up or ImGuiDir.Down, ARROW_SCALE)
        end

        -- Handle clicking on column header to adjust Sort Order
        if pressed and table_.ReorderColumn ~= column_n then
            local sort_direction = ImGui.TableGetColumnNextSortDirection(column)
            ImGui.TableSetColumnSortDirection(column_n, sort_direction, g.IO.KeyShift)
        end
    end

    -- Render clipped label. Clipping here ensure that in the majority of situations, all our header cells will
    -- be merged into a single draw call.
    --window.DrawList:AddCircleFilled(ImVec2(ellipsis_max, label_pos.y), 40, IM_COL32_WHITE)
    ImGui.RenderTextEllipsis(window.DrawList, label_pos, ImVec2(ellipsis_max, bb.Max.y), ellipsis_max, label, label_end, label_size)

    local text_clipped = label_size.x > (ellipsis_max - label_pos.x)
    if text_clipped and hovered and g.ActiveId == 0 then
        ImGui.SetItemTooltip("%s", string.sub(label, 1, label_end - 1))
    end

    -- We don't use BeginPopupContextItem() because we want the popup to stay up even after the column is hidden
    if ImGui.IsPopupOpenRequestForItem(ImGuiPopupFlags.None, id) then
        ImGui.TableOpenContextMenu(column_n)
    end
end

-- Unlike TableHeadersRow() it is not expected that you can reimplement or customize this with custom widgets.
-- FIXME: No hit-testing/button on the angled header.
function ImGui.TableAngledHeadersRow()
    local g = GImGui
    local table_ = g.CurrentTable
    local temp_data = table_.TempData
    temp_data.AngledHeadersRequests:resize(0)

    -- Which column needs highlight?
    local row_id = ImGui.GetID("##AngledHeaders")
    local table_instance = ImGui.TableGetInstanceData(table_, table_.InstanceCurrent)
    local highlight_column_n = (table_.LastHeldHeaderColumn ~= -1) and table_.LastHeldHeaderColumn or table_.HighlightColumnHeader
    if highlight_column_n == -1 and table_.HoveredColumnBody ~= -1 then
        if table_instance.HoveredRowLast == 0 and table_.HoveredColumnBorder == -1 and (g.ActiveId == 0 or g.ActiveId == row_id or (table_.IsActiveIdInTable or g.DragDropActive)) then
            highlight_column_n = table_.HoveredColumnBody
        end
    end

    -- Build up request
    local col_header_bg = ImGui.GetColorU32(ImGuiCol.TableHeaderBg)
    local col_text = ImGui.GetColorU32(ImGuiCol.Text)
    for order_n = 0, table_.ColumnsCount - 1 do
        if BitTest(table_.EnabledMaskByDisplayOrder, order_n) then
            local column_n = table_.DisplayOrderToIndex[order_n]
            local column = table_.Columns[column_n]
            if band(column.Flags, ImGuiTableColumnFlags.AngledHeader) ~= 0 then -- Note: can't rely on ImGuiTableColumnFlags.IsVisible test here.
                temp_data.AngledHeadersRequests:push_back({ Index = column_n, TextColor = col_text, BgColor0 = col_header_bg, BgColor1 = (column_n == highlight_column_n) and ImGui.GetColorU32(ImGuiCol.Header) or 0 })
            end
        end
    end

    -- Render row
    ImGui.TableAngledHeadersRowEx(row_id, g.Style.TableAngledHeadersAngle, 0.0, temp_data.AngledHeadersRequests.Data, temp_data.AngledHeadersRequests.Size)
end

local function ImTextCountLines(text, text_begin, text_end)
    local count = 0
    local p = text_begin
    while p < text_end do
        local line_end = string.find(text, "\n", p, true)
        if line_end == nil or line_end >= text_end then p = text_end else p = line_end + 1 end
        count = count + 1
    end
    return count
end

-- Important: data must be fed left to right
--- @param data       ImGuiTableHeaderData[] # 1-based array
--- @param data_count int
function ImGui.TableAngledHeadersRowEx(row_id, angle, max_label_width, data, data_count)
    local g = GImGui
    local table_ = g.CurrentTable
    local window = g.CurrentWindow
    local draw_list = window.DrawList
    IM_ASSERT_USER_ERROR_RET(table_ ~= nil, "Call should only be done while in BeginTable() scope!")
    IM_ASSERT(table_.CurrentRow == -1, "Must be first row")

    if max_label_width == 0.0 then
        max_label_width = ImGui.TableGetHeaderAngledMaxLabelWidth()
    end

    -- Angle argument expressed in (-IM_PI/2 .. +IM_PI/2) as it is easier to think about for user.
    local flip_label = (angle < 0.0)
    angle = angle - IM_PI * 0.5
    local cos_a = ImCos(angle)
    local sin_a = ImSin(angle)
    local label_cos_a = flip_label and ImCos(angle + IM_PI) or cos_a
    local label_sin_a = flip_label and ImSin(angle + IM_PI) or sin_a
    local unit_right = ImVec2(cos_a, sin_a)

    -- Calculate our base metrics and set angled headers data _before_ the first call to TableNextRow()
    -- FIXME-STYLE: Would it be better for user to submit 'max_label_width' or 'row_height' ? One can be derived from the other.
    local header_height = g.FontSize + g.Style.CellPadding.x * 2.0
    local row_height = ImTrunc(ImAbs(ImRotate(ImVec2(max_label_width, flip_label and header_height or -header_height), cos_a, sin_a).y))
    table_.AngledHeadersHeight = row_height
    table_.AngledHeadersSlope = (sin_a ~= 0.0) and (cos_a / sin_a) or 0.0
    local header_angled_vector = unit_right * (row_height / -sin_a) -- vector from bottom-left to top-left, and from bottom-right to top-right

    -- Declare row, override and draw our own background
    -- FIXME-TABLE: Generally broken when overlapping frozen columns limit.
    ImGui.TableNextRow(ImGuiTableRowFlags.Headers, row_height)
    ImGui.TableNextColumn()
    local row_r = ImRect(table_.WorkRect.Min.x, table_.BgClipRect.Min.y, table_.WorkRect.Max.x, table_.RowPosY2)
    table_.DrawSplitter:SetCurrentChannel(draw_list, TABLE_DRAW_CHANNEL_BG0)
    local clip_rect_min_x = table_.BgClipRect.Min.x
    if table_.FreezeColumnsCount > 0 then
        clip_rect_min_x = ImMax(clip_rect_min_x, table_.Columns[table_.DisplayOrderToIndex[table_.FreezeColumnsCount - 1]].MaxX)
    end
    ImGui.TableSetBgColor(ImGuiTableBgTarget.RowBg0, 0) -- Cancel
    ImGui.PushClipRect(table_.BgClipRect.Min, table_.BgClipRect.Max, false) -- Span all columns
    draw_list:AddRectFilled(ImVec2(table_.BgClipRect.Min.x, row_r.Min.y), ImVec2(table_.BgClipRect.Max.x, row_r.Max.y), ImGui.GetColorU32(ImGuiCol.TableHeaderBg, 0.25)) -- FIXME-STYLE: Change row background with an arbitrary color.
    ImGui.PushClipRect(ImVec2(clip_rect_min_x, table_.BgClipRect.Min.y), table_.BgClipRect.Max, true) -- Span all columns

    ImGui.ButtonBehavior(row_r, row_id)
    ImGui.KeepAliveID(row_id)

    local ascent_scaled = g.FontBaked.Ascent * g.FontBakedScale -- FIXME: Standardize those scaling factors better
    local line_off_for_ascent_x = (ImMax((g.FontSize - ascent_scaled) * 0.5, 0.0) / -sin_a) * (flip_label and -1.0 or 1.0)
    local padding = g.Style.CellPadding -- We will always use swapped component
    local align = g.Style.TableAngledHeadersTextAlign

    -- Draw background and labels in first pass, then all borders.
    local max_x = -FLT_MAX
    for pass = 0, 1 do
        for order_n = 0, data_count - 1 do
            local request = data[order_n + 1]
            local column_n = request.Index
            local column = table_.Columns[column_n]

            local bg_shape = {}
            bg_shape[0] = ImVec2(column.MaxX, row_r.Max.y)
            bg_shape[1] = ImVec2(column.MinX, row_r.Max.y)
            bg_shape[2] = bg_shape[1] + header_angled_vector
            bg_shape[3] = bg_shape[0] + header_angled_vector
            if pass == 0 then
                -- Draw shape
                draw_list:AddQuadFilled(bg_shape[0], bg_shape[1], bg_shape[2], bg_shape[3], request.BgColor0)
                draw_list:AddQuadFilled(bg_shape[0], bg_shape[1], bg_shape[2], bg_shape[3], request.BgColor1) -- Optional highlight
                max_x = ImMax(max_x, bg_shape[3].x)

                -- Draw label
                -- - First draw at an offset where RenderTextXXX() function won't meddle with applying current ClipRect, then transform to final offset.
                -- - Handle multiple lines manually, as we want each lines to follow on the horizontal border, rather than see a whole block rotated.
                local label_name = ImGui.TableGetColumnName(table_, column_n)
                local label_name_end = ImGui.FindRenderedTextEnd(label_name)
                local line_off_step_x = (g.FontSize / -sin_a)
                local label_lines = ImTextCountLines(label_name, 1, label_name_end)

                -- Left<>Right alignment
                local line_off_curr_x = flip_label and ((label_lines - 1) * line_off_step_x) or 0.0
                local line_off_for_align_x = ImFloor(ImMax((((column.MaxX - column.MinX) - padding.x * 2.0) - (label_lines * line_off_step_x)), 0.0) * align.x)
                line_off_curr_x = line_off_curr_x + line_off_for_align_x - line_off_for_ascent_x

                -- Register header width
                local w = column.WorkMinX + ImCeil(label_lines * line_off_step_x - line_off_for_align_x)
                column.ContentMaxXHeadersUsed = w; column.ContentMaxXHeadersIdeal = w

                local p = 1
                while p < label_name_end do
                    local label_name_eol = string.find(label_name, "\n", p, true)
                    if label_name_eol == nil or label_name_eol > label_name_end then
                        label_name_eol = label_name_end
                    end
                    local line = string.sub(label_name, p, label_name_eol - 1)

                    -- FIXME: Individual line clipping for right-most column is broken for negative angles.
                    local label_size = ImGui.CalcTextSize(line)
                    local clip_width = max_label_width - padding.y -- Using padding.y*2.0f would be symmetrical but hide more text.
                    local clip_height = ImMin(label_size.y, column.ClipRect.Max.x - column.WorkMinX - line_off_curr_x)
                    local clip_r = ImRect(window.ClipRect.Min, window.ClipRect.Min + ImVec2(clip_width, clip_height))
                    local vtx_idx_begin = draw_list._VtxCurrentIdx
                    ImGui.PushStyleColor(ImGuiCol.Text, request.TextColor)
                    ImGui.RenderTextEllipsis(draw_list, clip_r.Min, clip_r.Max, clip_r.Max.x, line, #line + 1, label_size)
                    ImGui.PopStyleColor()
                    local vtx_idx_end = draw_list._VtxCurrentIdx

                    -- Up<>Down alignment
                    local available_space = ImMax(clip_width - label_size.x + ImAbs(padding.x * cos_a) * 2.0 - ImAbs(padding.y * sin_a) * 2.0, 0.0)
                    local vertical_offset = available_space * align.y * (flip_label and -1.0 or 1.0)

                    -- Rotate and offset label
                    local pivot_in = ImVec2(window.ClipRect.Min.x - vertical_offset, window.ClipRect.Min.y + label_size.y)
                    local pivot_out = ImVec2(column.WorkMinX, row_r.Max.y)
                    line_off_curr_x = line_off_curr_x + (flip_label and -line_off_step_x or line_off_step_x)
                    pivot_out = pivot_out + unit_right * padding.y
                    if flip_label then
                        pivot_out = pivot_out + unit_right * (clip_width - ImMax(0.0, clip_width - label_size.x))
                    end
                    pivot_out.x = pivot_out.x + (flip_label and (line_off_curr_x + line_off_step_x) or line_off_curr_x)
                    ImGui.ShadeVertsTransformPos(draw_list, vtx_idx_begin, vtx_idx_end, pivot_in, label_cos_a, label_sin_a, pivot_out) -- Rotate and offset
                    --if g.IO.KeyShift then local fg_dl = GetForegroundDrawList(); vtx_idx_begin = fg_dl._VtxCurrentIdx; fg_dl:AddRect(clip_r.Min, clip_r.Max, IM_COL32(0, 255, 0, 255), 0.0, 0, 1.0); ShadeVertsTransformPos(fg_dl, vtx_idx_begin, fg_dl._VtxCurrentIdx, pivot_in, label_cos_a, label_sin_a, pivot_out) end

                    p = label_name_eol + 1
                end
            end
            if pass == 1 then
                -- Draw border
                local border_size = TABLE_BORDER_SIZE
                draw_list:AddLine(bg_shape[0] + ImVec2(border_size * 0.5, 0.0), bg_shape[3] + ImVec2(border_size * 0.5, 0.0), TableGetColumnBorderCol(table_, order_n, column_n), border_size)
            end
        end
    end
    ImGui.PopClipRect()
    ImGui.PopClipRect()
    table_.TempData.AngledHeadersExtraWidth = ImMax(0.0, max_x - table_.Columns[table_.RightMostEnabledColumn].MaxX)
end

-------------------------------------------------------------------------------
-- [SECTION] Tables: Context Menu
-------------------------------------------------------------------------------
-- - TableOpenContextMenu() [Internal]
-- - TableBeginContextMenuPopup() [Internal]
-- - TableDrawDefaultContextMenu() [Internal]
-------------------------------------------------------------------------------

-- Use -1 to open menu not specific to a given column.
function ImGui.TableOpenContextMenu(column_n)
    if column_n == nil then column_n = -1 end
    local g = GImGui
    local table_ = g.CurrentTable
    if column_n == -1 and table_.CurrentColumn ~= -1 then -- When called within a column automatically use this one (for consistency)
        column_n = table_.CurrentColumn
    end
    if column_n == table_.ColumnsCount then -- To facilitate using with TableGetHoveredColumn()
        column_n = -1
    end
    IM_ASSERT(column_n >= -1 and column_n < table_.ColumnsCount)
    if band(table_.Flags, bor(ImGuiTableFlags.Resizable, ImGuiTableFlags.Reorderable, ImGuiTableFlags.Hideable)) ~= 0 then
        table_.IsContextPopupOpen = true
        table_.ContextPopupColumn = column_n
        table_.InstanceInteracted = table_.InstanceCurrent
        local context_menu_id = ImHashStr("##ContextMenu", nil, table_.ID)
        ImGui.OpenPopupEx(context_menu_id, ImGuiPopupFlags.None)
    end
end

function ImGui.TableBeginContextMenuPopup(table_)
    if not table_.IsContextPopupOpen or table_.InstanceCurrent ~= table_.InstanceInteracted then
        return false
    end
    local context_menu_id = ImHashStr("##ContextMenu", nil, table_.ID)
    if ImGui.BeginPopupEx(context_menu_id, bor(ImGuiWindowFlags.AlwaysAutoResize, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoSavedSettings)) then
        return true
    end
    table_.IsContextPopupOpen = false
    return false
end

-- FIXME: Copied from MenuItem() for the purpose of being able to pass _SelectOnRelease (#9312)
local function MenuItemForColumnReorder(label, selected, enabled)
    local g = GImGui
    local window = g.CurrentWindow

    local label_size = ImGui.CalcTextSize(label, nil, true)
    local offsets = window.DC.MenuColumns
    local checkmark_w = IM_TRUNC(g.FontSize * 1.20)
    local min_w = offsets:DeclColumns(0.0, label_size.x, 0.0, checkmark_w) -- Feedback for next frame
    local stretch_w = ImMax(0.0, ImGui.GetContentRegionAvail().x - min_w)
    local text_pos = ImVec2(window.DC.CursorPos.x, window.DC.CursorPos.y + window.DC.CurrLineTextBaseOffset)

    local id = ImGui.GetID(label)
    local selectable_flags = bor(ImGuiSelectableFlags.SelectOnRelease, ImGuiSelectableFlags.SpanAvailWidth)
    if g.ActiveId == id then
        selectable_flags = bor(selectable_flags, ImGuiSelectableFlags.Highlight) -- Stays highlighted while dragging.
    end
    local has_been_moved = (g.ActiveId == id) and g.ActiveIdHasBeenEditedBefore -- But disable toggling once moved.

    ImGui.BeginDisabled(not enabled) -- Don't use ImGuiSelectableFlags.Disabled so that Check mark is also affected.
    local ret = ImGui.Selectable(label, false, selectable_flags, ImVec2(min_w, label_size.y)) and not has_been_moved -- Can't use IsMouseDragging(0) as button is released already.
    if band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.Visible) ~= 0 and selected then
        ImGui.RenderCheckMark(window.DrawList, text_pos + ImVec2(offsets.OffsetMark + stretch_w + g.FontSize * 0.40, g.FontSize * 0.134 * 0.5), ImGui.GetColorU32(ImGuiCol.Text), g.FontSize * 0.866)
    end
    ImGui.EndDisabled()

    return ret
end

-- Output context menu into current window (generally a popup)
-- FIXME-TABLE: Ideally this should be writable by the user. Full programmatic access to that data?
-- Sections to display are pulled from 'flags_for_section_to_display', which is typically == table.Flags.
-- - ImGuiTableFlags.Resizable   -> display Sizing menu items
-- - ImGuiTableFlags.Reorderable -> display "Reset Order"
---- ImGuiTableFlags.Sortable   -> display sorting options (disabled)
-- - ImGuiTableFlags.Hideable    -> display columns visibility menu items
-- It means if you have a custom context menus you can call this section and omit some sections, and add your own.
function ImGui.TableDrawDefaultContextMenu(table_, flags_for_section_to_display)
    local g = GImGui
    local window = g.CurrentWindow
    if window.SkipItems then
        return
    end

    local want_separator = false
    local context_column_n = (table_.ContextPopupColumn >= 0 and table_.ContextPopupColumn < table_.ColumnsCount) and table_.ContextPopupColumn or -1
    local context_column = (context_column_n ~= -1) and table_.Columns[context_column_n] or nil

    -- Sizing
    if band(flags_for_section_to_display, ImGuiTableFlags.Resizable) ~= 0 then
        if context_column ~= nil then
            local can_resize = band(context_column.Flags, ImGuiTableColumnFlags.NoResize) == 0 and context_column.IsEnabled
            if ImGui.MenuItem(ImGui.LocalizeGetMsg(ImGuiLocKey.TableSizeOne), nil, false, can_resize) then -- "###SizeOne"
                ImGui.TableSetColumnWidthAutoSingle(table_, context_column_n)
            end
        end

        local size_all_desc
        if table_.ColumnsEnabledFixedCount == table_.ColumnsEnabledCount and band(table_.Flags, ImGuiTableFlags.SizingMask_) ~= ImGuiTableFlags.SizingFixedSame then
            size_all_desc = ImGui.LocalizeGetMsg(ImGuiLocKey.TableSizeAllFit)        -- "###SizeAll" All fixed
        else
            size_all_desc = ImGui.LocalizeGetMsg(ImGuiLocKey.TableSizeAllDefault)    -- "###SizeAll" All stretch or mixed
        end
        if ImGui.MenuItem(size_all_desc, nil) then
            ImGui.TableSetColumnWidthAutoAll(table_)
        end
        want_separator = true
    end

    -- Reset Order/Visibility etc.
    if band(flags_for_section_to_display, bor(ImGuiTableFlags.Reorderable, ImGuiTableFlags.Hideable)) ~= 0 then
        if ImGui.BeginMenu(ImGui.LocalizeGetMsg(ImGuiLocKey.TableReset)) then
            --if ImGui.MenuItem(ImGui.LocalizeGetMsg(ImGuiLocKey.TableResetAll)) then -- FIXME: Hiding because altering Sort Order + requesting auto-fit simultaneously has a tendency to exhibit a sizing glitch.
            --    table_.IsResetAllRequest = true
            --end
            if band(flags_for_section_to_display, ImGuiTableFlags.Reorderable) ~= 0 then
                if ImGui.MenuItem(ImGui.LocalizeGetMsg(ImGuiLocKey.TableResetOrder), nil, false, not table_.IsDefaultDisplayOrder) then -- PS: cannot be hidden because it would mess with drag reordering.
                    table_.IsResetDisplayOrderRequest = true
                end
            end
            if band(flags_for_section_to_display, ImGuiTableFlags.Hideable) ~= 0 then
                if ImGui.MenuItem(ImGui.LocalizeGetMsg(ImGuiLocKey.TableResetVisibility), nil, false, not table_.IsDefaultVisibility) then
                    table_.IsResetVisibilityRequest = true
                end
            end
            ImGui.EndMenu()
        end
    end

    -- Sorting
    -- (modify TableOpenContextMenu() to add _Sortable flag if enabling this)
    -- #if 0
    --if band(flags_for_section_to_display, ImGuiTableFlags.Sortable) ~= 0 and column ~= nil and band(column.Flags, ImGuiTableColumnFlags.NoSort) == 0 then
    --    if want_separator then ImGui.Separator() end
    --    want_separator = true
    --    local append_to_sort_specs = g.IO.KeyShift
    --    if ImGui.MenuItem("Sort in Ascending Order", nil, column.SortOrder ~= -1 and column.SortDirection == ImGuiSortDirection.Ascending, band(column.Flags, ImGuiTableColumnFlags.NoSortAscending) == 0) then
    --        ImGui.TableSetColumnSortDirection(table_, column_n, ImGuiSortDirection.Ascending, append_to_sort_specs)
    --    end
    --    if ImGui.MenuItem("Sort in Descending Order", nil, column.SortOrder ~= -1 and column.SortDirection == ImGuiSortDirection.Descending, band(column.Flags, ImGuiTableColumnFlags.NoSortDescending) == 0) then
    --        ImGui.TableSetColumnSortDirection(table_, column_n, ImGuiSortDirection.Descending, append_to_sort_specs)
    --    end
    --end
    -- #endif

    -- Hiding / Visibility
    if band(flags_for_section_to_display, ImGuiTableFlags.Hideable) ~= 0 then
        if want_separator then
            ImGui.Separator()
        end
        want_separator = true

        -- While reordering: we calculate min/max allowed range once here so we can avoid a O(N log N) in the loop (because the query itself does a sweep scan).
        -- This assume that reordering constraints output a single range, otherwise would need to either call TableGetMaxDisplayOrderAllowed() for each item below, or cache this once per frame into columns.
        local is_reordering = (g.ActiveId ~= 0 and g.ActiveIdWindow == g.CurrentWindow and table_.ReorderColumn ~= -1 and g.ActiveIdHasBeenEditedBefore) -- FIXME: This is a bit of a hack.
        local reorder_src_order = is_reordering and table_.Columns[table_.ReorderColumn].DisplayOrder or -1
        local reorder_min_order = is_reordering and TableGetMaxDisplayOrderAllowed(table_, reorder_src_order, 0) or 0
        local reorder_max_order = is_reordering and TableGetMaxDisplayOrderAllowed(table_, reorder_src_order, table_.ColumnsCount - 1) or (table_.ColumnsCount - 1)
        ImGui.PushItemFlag(ImGuiItemFlags.AutoClosePopups, false)
        for order_n = 0, table_.ColumnsCount - 1 do
            local column_n = table_.DisplayOrderToIndex[order_n]
            local column = table_.Columns[column_n]
            if band(column.Flags, ImGuiTableColumnFlags.Disabled) == 0 then
                local name = ImGui.TableGetColumnName(table_, column_n)
                if name == nil or name == "" then
                    name = "<Unknown>"
                end

                -- Make sure we can't hide the last active column
                local menu_item_enabled = band(column.Flags, ImGuiTableColumnFlags.NoHide) == 0
                if column.IsUserEnabled and table_.ColumnsEnabledCount <= 1 then
                    menu_item_enabled = false
                end
                if is_reordering and (column.DisplayOrder < reorder_min_order or column.DisplayOrder > reorder_max_order) then
                    menu_item_enabled = false
                end
                if MenuItemForColumnReorder(name, column.IsUserEnabled, menu_item_enabled) then
                    column.IsUserEnabledNextFrame = not column.IsUserEnabled
                end

                -- Drag to reorder
                -- FIXME: It is currently not possible to reorder columns marked with ImGuiTableColumnFlags.NoHide.
                if ImGui.IsItemActive() and ImGui.IsMouseDragging(0) and g.ActiveIdSource == ImGuiInputSource.Mouse and band(table_.Flags, ImGuiTableFlags.Reorderable) ~= 0 then
                    g.ActiveIdHasBeenEditedBefore = true -- Disable toggle in MenuItemForColumnReorder() + start dimming to display allowed reorder targets.
                    table_.ReorderColumn = column_n
                    if not ImGui.IsItemHovered() then
                        local reorder_dir = (g.IO.MousePos.y < (g.LastItemData.Rect.Min.y + g.LastItemData.Rect.Max.y) * 0.5) and -1 or 1
                        local reorder_amount = ((reorder_dir < 0) and (g.LastItemData.Rect.Min.y - g.IO.MousePos.y) or (g.IO.MousePos.y - g.LastItemData.Rect.Max.y)) / g.LastItemData.Rect:GetHeight()
                        local dst_order = column.DisplayOrder + ImTrunc(ImCeil(reorder_amount)) * reorder_dir -- Estimated target order, will be validated and clamped.
                        ImGui.TableQueueSetColumnDisplayOrder(table_, column_n, dst_order)
                    end
                end
            end
        end
        ImGui.PopItemFlag()
    end
end

-------------------------------------------------------------------------------
-- [SECTION] Tables: Settings (.ini data)
-------------------------------------------------------------------------------
-- FIXME: The binding/finding/creating flow are too confusing.
-------------------------------------------------------------------------------
-- - TableSettingsInit() [Internal]
-- - TableSettingsCreate() [Internal]
-- - TableSettingsFindByID() [Internal]
-- - TableGetBoundSettings() [Internal]
-- - TableResetSettings()
-- - TableSaveSettings() [Internal]
-- - TableLoadSettings() [Internal]
-- - TableLoadSettingsForColumns() [Internal]
-- - TableSettingsHandler_ClearAll() [Internal]
-- - TableSettingsHandler_ApplyAll() [Internal]
-- - TableSettingsHandler_ReadOpen() [Internal]
-- - TableSettingsHandler_ReadLine() [Internal]
-- - TableSettingsHandler_WriteAll() [Internal]
-- - TableSettingsAddSettingsHandler() [Internal]
-------------------------------------------------------------------------------
-- [Init] 1: TableSettingsHandler_ReadXXXX()   Load and parse .ini file into TableSettings.
-- [Main] 2: TableLoadSettings()               When table is created, bind Table to TableSettings, serialize TableSettings data into Table.
-- [Main] 3: TableSaveSettings()               When table properties are modified, serialize Table data into bound or new TableSettings, mark .ini as dirty.
-- [Main] 4: TableSettingsHandler_WriteAll()   When .ini file is dirty (which can come from other source), save TableSettings into .ini file.
-------------------------------------------------------------------------------

-- Clear and initialize empty settings instance
local function TableSettingsInit(settings, id, columns_count, columns_count_max)
    for k, v in pairs(ImGuiTableSettings()) do settings[k] = v end
    for n = 0, columns_count_max - 1 do
        settings.Columns[n] = ImGuiTableColumnSettings()
    end
    settings.ID = id
    settings.ColumnsCount = columns_count
    settings.ColumnsCountMax = columns_count_max
    settings.WantApply = true
end

function ImGui.TableSettingsCreate(id, columns_count)
    local g = GImGui
    local settings = ImGui.TableSettingsFindByID(id)
    if settings then
        if settings.ColumnsCountMax >= columns_count then
            TableSettingsInit(settings, id, columns_count, settings.ColumnsCountMax) -- Recycle
            return settings
        end
        settings.ID = 0 -- Invalidate storage, we won't fit because of a count change
    end
    settings = ImGuiTableSettings()
    g.SettingsTables:push_back(settings)
    TableSettingsInit(settings, id, columns_count, columns_count)
    return settings
end

-- Find existing settings
function ImGui.TableSettingsFindByID(id)
    -- FIXME-OPT: Might want to store a lookup map for this?
    local g = GImGui
    for _, settings in g.SettingsTables:iter() do
        if settings.ID == id then
            return settings
        end
    end
    return nil
end

local function SettingsTablesOffsetFromPtr(settings)
    local g = GImGui
    return g.SettingsTables:find_index(settings) or -1
end

-- Get settings for a given table, nil if none
function ImGui.TableGetBoundSettings(table_)
    if table_.SettingsOffset == -1 then
        return nil
    end
    local g = GImGui
    local settings = g.SettingsTables.Data[table_.SettingsOffset]
    IM_ASSERT(settings.ID == table_.ID)
    return settings
end

-- Restore initial state of table (with or without saved settings)
function ImGui.TableResetSettings(table_)
    table_.IsInitializing = true; table_.IsSettingsDirty = true
    table_.IsResetAllRequest = false
    table_.IsSettingsRequestLoad = false                    -- Don't reload from ini
    table_.SettingsLoadedFlags = ImGuiTableFlags.None       -- Mark as nothing loaded so our initialized data becomes authoritative
end

function ImGui.TableSaveSettings(table_)
    table_.IsSettingsDirty = false
    if band(table_.Flags, ImGuiTableFlags.NoSavedSettings) ~= 0 then
        return
    end

    -- Bind or create settings data
    local settings = ImGui.TableGetBoundSettings(table_)
    if settings ~= nil and table_.ColumnsCount > settings.ColumnsCountMax then
        settings.ID = 0 -- Invalidate storage, we won't fit because of a count change
        settings = nil
    end
    if settings == nil then
        settings = ImGui.TableSettingsCreate(table_.ID, table_.ColumnsCount)
        table_.SettingsOffset = SettingsTablesOffsetFromPtr(settings)
    end
    settings.ColumnsCount = table_.ColumnsCount

    -- Serialize ImGuiTable/ImGuiTableColumn into ImGuiTableSettings/ImGuiTableColumnSettings
    IM_ASSERT(settings.ID == table_.ID)
    IM_ASSERT(settings.ColumnsCount == table_.ColumnsCount and settings.ColumnsCountMax >= settings.ColumnsCount)

    local save_ref_scale = false
    settings.SaveFlags = ImGuiTableFlags.None
    for n = 0, table_.ColumnsCount - 1 do
        local column = table_.Columns[n]
        local column_settings = settings.Columns[n]
        local width_or_weight = (band(column.Flags, ImGuiTableColumnFlags.WidthStretch) ~= 0) and column.StretchWeight or column.WidthRequest
        column_settings.ID = column.ID
        column_settings.WidthOrWeight = width_or_weight
        column_settings.Index = n
        column_settings.DisplayOrder = column.DisplayOrder
        column_settings.SortOrder = column.SortOrder
        column_settings.SortDirection = column.SortDirection
        column_settings.IsEnabled = column.IsUserEnabled and 1 or 0
        column_settings.IsStretch = (band(column.Flags, ImGuiTableColumnFlags.WidthStretch) ~= 0) and 1 or 0
        if band(column.Flags, ImGuiTableColumnFlags.WidthStretch) == 0 then
            save_ref_scale = true
        end

        -- We skip saving some data in the .ini file when they are unnecessary to restore our state.
        -- Note that fixed width where initial width was derived from auto-fit will always be saved as InitStretchWeightOrWidth will be 0.0f.
        -- FIXME-TABLE: We don't have logic to easily compare SortOrder to DefaultSortOrder yet so it's always saved when present.
        if width_or_weight ~= column.InitStretchWeightOrWidth then
            settings.SaveFlags = bor(settings.SaveFlags, ImGuiTableFlags.Resizable)
        end
        if column.DisplayOrder ~= n then
            settings.SaveFlags = bor(settings.SaveFlags, ImGuiTableFlags.Reorderable)
        end
        if column.SortOrder ~= -1 then
            settings.SaveFlags = bor(settings.SaveFlags, ImGuiTableFlags.Sortable, ImGuiTableFlags.Reorderable) -- Because SortOrder saving itself is gated, make sure every column is saved (#9519)
        end
        if column.IsUserEnabled ~= (band(column.Flags, ImGuiTableColumnFlags.DefaultHide) == 0) then
            settings.SaveFlags = bor(settings.SaveFlags, ImGuiTableFlags.Hideable)
        end
    end
    settings.SaveFlags = band(settings.SaveFlags, table_.Flags)
    settings.RefScale = save_ref_scale and table_.RefScale or 0.0

    ImGui.MarkIniSettingsDirty()
end

function ImGui.TableLoadSettings(table_)
    if band(table_.Flags, ImGuiTableFlags.NoSavedSettings) ~= 0 then
        table_.IsSettingsRequestLoad = false -- Done
        return
    end

    -- Bind settings
    local settings
    if table_.SettingsOffset == -1 then
        settings = ImGui.TableSettingsFindByID(table_.ID)
        if settings == nil then
            return
        end
        if settings.ColumnsCount ~= table_.ColumnsCount then -- Allow settings if columns count changed. We could otherwise decide to return...
            table_.IsSettingsDirty = true
        end
        table_.SettingsOffset = SettingsTablesOffsetFromPtr(settings)
    else
        settings = ImGui.TableGetBoundSettings(table_)
    end

    table_.SettingsLoadedFlags = settings.SaveFlags
    table_.RefScale = settings.RefScale
    -- TableUpdateLayout() will then call TableLoadSettingsForColumns() to apply the data.
end

-- NB: This was written to be similar to the logic in TableReconcileColumns().
function ImGui.TableLoadSettingsForColumns(table_)
    for n = 0, table_.ColumnsSize - 1 do
        table_.Columns[n].IsLoadedSettings = false
    end
    local settings = ImGui.TableGetBoundSettings(table_)
    if settings == nil then
        return
    end

    table_.SettingsLoadedFlags = bor(table_.SettingsLoadedFlags, ImGuiTableFlags.Reorderable) -- We handle above in code above.

    -- Serialize ImGuiTableSettings/ImGuiTableColumnSettings into ImGuiTable/ImGuiTableColumn
    local column_settings = settings.Columns

    -- Fast path
    local matches = 0
    for n = 0, table_.ColumnsCount - 1 do
        if n >= settings.ColumnsCount or column_settings[n].ID ~= table_.Columns[n].ID then
            break
        end
        ImGui.TableLoadSettingsForColumn(table_.Columns[n], column_settings[n], settings.SaveFlags)
        matches = matches + 1
    end
    if matches == settings.ColumnsCount then
        return
    end
    local settings_start_n = matches -- Small optimization
    for n = settings_start_n, settings.ColumnsCount - 1 do
        column_settings[n].IsLoaded = false
    end

    -- Find matches for named columns
    for c = 0, table_.ColumnsSize - 1 do
        local column = table_.Columns[c]
        if column.ID ~= 0 and not column.IsLoadedSettings then
            for n = settings_start_n, settings.ColumnsCount - 1 do
                if column_settings[n].ID == column.ID and not column_settings[n].IsLoaded then
                    ImGui.TableLoadSettingsForColumn(column, column_settings[n], settings.SaveFlags)
                    matches = matches + 1
                    break
                end
            end
        end
    end

    -- Remaining entries are matched sequentially
    local dst_idx = 0
    for n = settings_start_n, settings.ColumnsCount - 1 do
        if not column_settings[n].IsLoaded then
            while dst_idx < table_.ColumnsCount and table_.Columns[dst_idx].IsLoadedSettings do
                dst_idx = dst_idx + 1
            end
            if dst_idx >= table_.ColumnsCount then
                break
            end
            ImGui.TableLoadSettingsForColumn(table_.Columns[dst_idx], column_settings[n], settings.SaveFlags)
            dst_idx = dst_idx + 1
        end
    end
end

function ImGui.TableLoadSettingsForColumn(column, column_settings, load_flags)
    column.IsLoadedSettings = true
    column_settings.IsLoaded = true
    if band(load_flags, ImGuiTableFlags.Resizable) ~= 0 then
        if column_settings.IsStretch ~= 0 then
            column.StretchWeight = column_settings.WidthOrWeight
        else
            column.WidthRequest = column_settings.WidthOrWeight
        end
        column.AutoFitQueue = 0x00
    end
    if band(load_flags, ImGuiTableFlags.Reorderable) ~= 0 then
        column.DisplayOrder = column_settings.DisplayOrder
    else
        column.DisplayOrder = column_settings.Index -- Because default depends on previous Index, we need to set that up and cannot rely on TableInitColumnDefaults()
    end
    if band(load_flags, ImGuiTableFlags.Hideable) ~= 0 and column_settings.IsEnabled ~= -1 then
        local v = (column_settings.IsEnabled == 1)
        column.IsUserEnabled = v; column.IsUserEnabledNextFrame = v
    end
    column.SortOrder = column_settings.SortOrder
    column.SortDirection = column_settings.SortDirection
end

-- Fix invalid display order data: compact values (0,1,3 -> 0,1,2); preserve relative order (0,3,1 -> 0,2,1); deduplicate (0,4,1,1 -> 0,3,1,2)
function ImGui.TableFixDisplayOrder(table_)
    if band(table_.Flags, ImGuiTableFlags.Reorderable) == 0 then
        for n = 0, table_.ColumnsCount - 1 do
            table_.Columns[n].DisplayOrder = n
            table_.DisplayOrderToIndex[n] = n
        end
        return
    end
    local fdo_columns = {}
    for n = 0, table_.ColumnsCount - 1 do
        fdo_columns[n + 1] = n
    end
    -- Sort by DisplayOrder and then Index
    -- Assume ImGuiTableColumnIdx == signed short, to turn -1 into a large value so that it always sort after.
    local function key(idx)
        local o = table_.Columns[idx].DisplayOrder
        if o < 0 then o = o + 0x10000 end
        return o
    end
    table.sort(fdo_columns, function(lhs_idx, rhs_idx)
        local a, b = key(lhs_idx), key(rhs_idx)
        if a ~= b then return a < b end
        return lhs_idx < rhs_idx
    end)
    for n = 0, table_.ColumnsCount - 1 do
        table_.Columns[fdo_columns[n + 1]].DisplayOrder = n
    end
    for n = 0, table_.ColumnsCount - 1 do
        table_.DisplayOrderToIndex[table_.Columns[n].DisplayOrder] = n
    end
end

local function ForEachTable(g, fn)
    for i = 0, g.Tables:GetMapSize() - 1 do
        local t = g.Tables:GetByIndex(i)
        if t then fn(t) end
    end
end

local function TableSettingsHandler_ClearAll(ctx, handler)
    local g = ctx
    ForEachTable(g, function(t) t.SettingsOffset = -1 end)
    g.SettingsTables:clear()
end

-- Apply to existing windows (if any)
local function TableSettingsHandler_ApplyAll(ctx, handler)
    local g = ctx
    ForEachTable(g, function(t)
        t.IsSettingsRequestLoad = true
        t.SettingsOffset = -1
    end)
end

local function TableSettingsHandler_ReadOpen(ctx, handler, name)
    -- FIXME: As topology changes are allowed, strictly speaking a >= IMGUI_TABLE_MAX_COLUMNS tables stored in .ini file
    -- that was emitted with a higher max count could still be meaningful in some unlikely cases.
    -- We might want to use another MAX defined as (1<<(sizeof(ImGuiTableColumnIdx)*8-1))-1.
    local id, columns_count = string.match(name, "^0x(%x+),(%-?%d+)")
    if id == nil then
        return nil
    end
    id = tonumber(id, 16); columns_count = tonumber(columns_count)
    if columns_count <= 0 or columns_count >= IMGUI_TABLE_MAX_COLUMNS then
        return nil
    end
    return ImGui.TableSettingsCreate(id, columns_count)
end

local function TableSettingsHandler_ReadLine(ctx, handler, settings, line)
    -- "Column 0  UserID=0x42AD2D21 Width=100 Visible=1 Order=0 Sort=0v"
    if settings == nil then return end
    local f = string.match(line, "^RefScale=([%-%d%.eE+]+)")
    if f then settings.RefScale = tonumber(f); return end
    local n = string.match(line, "^LastUsed=(%d+)")
    if n then settings.LastUsedDate = tonumber(n); return end

    local column_n, rest = string.match(line, "^Column (%-?%d+)(.*)$")
    if column_n then
        column_n = tonumber(column_n)
        if column_n < 0 or column_n >= settings.ColumnsCount then
            return
        end
        local column = settings.Columns[column_n]
        column.Index = column_n
        local function take(pattern)
            local a, b, r = string.match(rest, "^%s*" .. pattern .. "()")
            if a == nil then return nil end
            if r == nil then r = b; b = nil end
            rest = string.sub(rest, r)
            return a, b
        end
        take("UserID=0x(%x+)") -- FIXME-LEGACY: Removed 2025/11/12, was never properly set.
        local v = take("Width=(%-?%d+)")
        if v then column.WidthOrWeight = tonumber(v); column.IsStretch = 0; settings.SaveFlags = bor(settings.SaveFlags, ImGuiTableFlags.Resizable) end
        v = take("Weight=([%-%d%.eE+]+)")
        if v then column.WidthOrWeight = tonumber(v); column.IsStretch = 1; settings.SaveFlags = bor(settings.SaveFlags, ImGuiTableFlags.Resizable) end
        v = take("Visible=(%-?%d+)")
        if v then column.IsEnabled = tonumber(v); settings.SaveFlags = bor(settings.SaveFlags, ImGuiTableFlags.Hideable) end
        v = take("Order=(%-?%d+)")
        if v then column.DisplayOrder = tonumber(v); settings.SaveFlags = bor(settings.SaveFlags, ImGuiTableFlags.Reorderable) end
        local c
        v, c = take("Sort=(%-?%d+)(.)")
        if v then column.SortOrder = tonumber(v); column.SortDirection = (c == "^") and ImGuiSortDirection.Descending or ImGuiSortDirection.Ascending; settings.SaveFlags = bor(settings.SaveFlags, ImGuiTableFlags.Sortable) end
        v = take("ID=0x(%x+)")
        if v then column.ID = tonumber(v, 16) end
    end
end

local function TableSettingsHandler_WriteAll(ctx, handler, buf)
    local g = ctx
    for _, settings in g.SettingsTables:iter() do
        if settings.ID ~= 0 then -- Skip ditched settings
            -- TableSaveSettings() may clear some of those flags when we establish that the data can be stripped
            -- (e.g. Order was unchanged)
            local save_size    = band(settings.SaveFlags, ImGuiTableFlags.Resizable) ~= 0
            local save_visible = band(settings.SaveFlags, ImGuiTableFlags.Hideable) ~= 0
            local save_order   = band(settings.SaveFlags, ImGuiTableFlags.Reorderable) ~= 0
            local save_sort    = band(settings.SaveFlags, ImGuiTableFlags.Sortable) ~= 0
            -- We need to save the [Table] entry even if all the bools are false, since this records a table with "default settings".

            buf:appendf("[%s][0x%08X,%d]\n", handler.TypeName, settings.ID, settings.ColumnsCount)
            if settings.RefScale ~= 0.0 then
                buf:appendf("RefScale=%g\n", settings.RefScale)
            end
            for column_n = 0, settings.ColumnsCount - 1 do
                local column = settings.Columns[column_n]
                -- "Column 0  UserID=0x42AD2D21 Width=100 Visible=1 Order=0 Sort=0v"
                local save_column = save_size or save_visible or save_order or (save_sort and column.SortOrder ~= -1)
                if save_column then
                    buf:appendf("Column %-2d", column_n)
                    if save_size and column.IsStretch ~= 0 then buf:appendf(" Weight=%.4f", column.WidthOrWeight) end
                    if save_size and column.IsStretch == 0 then buf:appendf(" Width=%d", ImTrunc(column.WidthOrWeight)) end
                    if save_visible then buf:appendf(" Visible=%d", column.IsEnabled) end
                    if save_order then buf:appendf(" Order=%d", column.DisplayOrder) end
                    if save_sort and column.SortOrder ~= -1 then buf:appendf(" Sort=%d%s", column.SortOrder, (column.SortDirection == ImGuiSortDirection.Ascending) and "v" or "^") end
                    if column.ID ~= 0 then buf:appendf(" ID=0x%08X", column.ID) end
                    buf:append("\n")
                end
            end
            if g.IO.ConfigIniSettingsSaveLastUsedDate and settings.LastUsedDate ~= 0 then
                buf:appendf("LastUsed=%08d\n", settings.LastUsedDate)
            end
            buf:append("\n")
        end
    end
end

function ImGui.TableSettingsAddSettingsHandler()
    local ini_handler = ImGuiSettingsHandler()
    ini_handler.TypeName = "Table"
    ini_handler.TypeHash = ImHashStr("Table")
    ini_handler.ClearAllFn = TableSettingsHandler_ClearAll
    ini_handler.ReadOpenFn = TableSettingsHandler_ReadOpen
    ini_handler.ReadLineFn = TableSettingsHandler_ReadLine
    ini_handler.ApplyAllFn = TableSettingsHandler_ApplyAll
    ini_handler.WriteAllFn = TableSettingsHandler_WriteAll
    ImGui.AddSettingsHandler(ini_handler)
end

-------------------------------------------------------------------------------
-- [SECTION] Tables: Garbage Collection
-------------------------------------------------------------------------------
-- - TableRemove() [Internal]
-- - TableGcCompactTransientBuffers() [Internal]
-- - TableGcCompactSettings() [Internal]
-------------------------------------------------------------------------------

-- Remove Table data (currently only used by TestEngine)
function ImGui.TableRemove(table_)
    --IMGUI_DEBUG_PRINT("TableRemove() id=0x%08X\n", table_.ID)
    local g = GImGui
    local table_idx = g.Tables:GetIndex(table_)
    g.Tables:Remove(table_.ID, table_)
    g.TablesLastTimeActive.Data[table_idx + 1] = -1.0
end

-- Free up/compact internal Table buffers for when it gets unused
-- Overloads: (ImGuiTable) / (ImGuiTableTempData)
function ImGui.TableGcCompactTransientBuffers(t)
    if not t then return end
    if t.TableIndex ~= nil then -- ImGuiTableTempData
        t.AngledHeadersRequests:clear()
        t.DrawSplitter:ClearFreeMemory()
        t.LastTimeActive = -1.0
        return
    end
    --IMGUI_DEBUG_PRINT("TableGcCompactTransientBuffers() id=0x%08X\n", t.ID)
    local g = GImGui
    local table_ = t
    IM_ASSERT(table_.MemoryCompacted == false)
    table_.SortSpecs.Specs = nil
    table.clear(table_.SortSpecsMulti)
    table_.IsSortSpecsDirty = true -- FIXME: In theory shouldn't have to leak into user performing a sort on resume.
    table.clear(table_.ColumnsNames)
    table_.MemoryCompacted = true
    for n = 0, table_.ColumnsCount - 1 do
        table_.Columns[n].NameOffset = -1
    end
    g.TablesLastTimeActive.Data[g.Tables:GetIndex(table_) + 1] = -1.0
end

-- Compact and remove unused or resize settings data (only TestEngine mark unused, but resizing table down can lead to compaction)
function ImGui.TableGcCompactSettings()
    local g = GImGui
    local has_dead = false
    for _, settings in g.SettingsTables:iter() do
        if settings.ID == 0 then has_dead = true end
    end
    if not has_dead then
        return
    end
    local new_list = ImVector()
    for _, settings in g.SettingsTables:iter() do
        if settings.ID ~= 0 then new_list:push_back(settings) end
    end
    g.SettingsTables = new_list
    ForEachTable(g, function(t) t.SettingsOffset = -1 end)
end

-------------------------------------------------------------------------------
-- [SECTION] Columns, BeginColumns, EndColumns, etc.
-- (This is a legacy API, prefer using BeginTable/EndTable!)
-------------------------------------------------------------------------------
-- FIXME: sizing is lossy when columns width is very small (default width may turn negative etc.)
-------------------------------------------------------------------------------
-- - GetColumnIndex()
-- - GetColumnsCount()
-- - GetColumnOffset()
-- - GetColumnWidth()
-- - SetColumnOffset()
-- - SetColumnWidth()
-- - PushColumnClipRect() [Internal]
-- - PushColumnsBackground() [Internal]
-- - PopColumnsBackground() [Internal]
-- - FindOrCreateColumns() [Internal]
-- - GetColumnsID() [Internal]
-- - BeginColumns()
-- - NextColumn()
-- - EndColumns()
-- - Columns()
-------------------------------------------------------------------------------
-- (Lua: columns.Columns is an ImVector, column n lives in .Data[n + 1])

function ImGui.GetColumnIndex()
    local window = ImGui.GetCurrentWindowRead()
    return window.DC.CurrentColumns and window.DC.CurrentColumns.Current or 0
end

function ImGui.GetColumnsCount()
    local window = ImGui.GetCurrentWindowRead()
    return window.DC.CurrentColumns and window.DC.CurrentColumns.Count or 1
end

function ImGui.GetColumnOffsetFromNorm(columns, offset_norm)
    return offset_norm * (columns.OffMaxX - columns.OffMinX)
end

function ImGui.GetColumnNormFromOffset(columns, offset)
    return offset / (columns.OffMaxX - columns.OffMinX)
end

local COLUMNS_HIT_RECT_HALF_THICKNESS = 4.0

local function GetDraggedColumnOffset(columns, column_index)
    -- Active (dragged) column always follow mouse. The reason we need this is that dragging a column to the right edge of an auto-resizing
    -- window creates a feedback loop because we store normalized positions. So while dragging we enforce absolute positioning.
    local g = GImGui
    local window = g.CurrentWindow
    IM_ASSERT(column_index > 0) -- We are not supposed to drag column 0.
    IM_ASSERT(g.ActiveId == band(columns.ID + column_index, 0xFFFFFFFF))

    local x = g.IO.MousePos.x - g.ActiveIdClickOffset.x + ImTrunc(COLUMNS_HIT_RECT_HALF_THICKNESS * g.CurrentDpiScale) - window.Pos.x
    x = ImMax(x, ImGui.GetColumnOffset(column_index - 1) + g.Style.ColumnsMinSpacing)
    if band(columns.Flags, ImGuiOldColumnFlags.NoPreserveWidths) ~= 0 then
        x = ImMin(x, ImGui.GetColumnOffset(column_index + 1) - g.Style.ColumnsMinSpacing)
    end

    return x
end

function ImGui.GetColumnOffset(column_index)
    if column_index == nil then column_index = -1 end
    local window = ImGui.GetCurrentWindowRead()
    local columns = window.DC.CurrentColumns
    if columns == nil then
        return 0.0
    end

    if column_index < 0 then
        column_index = columns.Current
    end
    IM_ASSERT(column_index < columns.Columns.Size)

    local t = columns.Columns.Data[column_index + 1].OffsetNorm
    local x_offset = ImLerp(columns.OffMinX, columns.OffMaxX, t)
    return x_offset
end

local function GetColumnWidthEx(columns, column_index, before_resize)
    if column_index < 0 then
        column_index = columns.Current
    end

    local d = columns.Columns.Data
    local offset_norm
    if before_resize then
        offset_norm = d[column_index + 2].OffsetNormBeforeResize - d[column_index + 1].OffsetNormBeforeResize
    else
        offset_norm = d[column_index + 2].OffsetNorm - d[column_index + 1].OffsetNorm
    end
    return ImGui.GetColumnOffsetFromNorm(columns, offset_norm)
end

function ImGui.GetColumnWidth(column_index)
    if column_index == nil then column_index = -1 end
    local g = GImGui
    local window = g.CurrentWindow
    local columns = window.DC.CurrentColumns
    if columns == nil then
        return ImGui.GetContentRegionAvail().x
    end

    if column_index < 0 then
        column_index = columns.Current
    end
    local d = columns.Columns.Data
    return ImGui.GetColumnOffsetFromNorm(columns, d[column_index + 2].OffsetNorm - d[column_index + 1].OffsetNorm)
end

function ImGui.SetColumnOffset(column_index, offset)
    local g = GImGui
    local window = g.CurrentWindow
    local columns = window.DC.CurrentColumns
    IM_ASSERT(columns ~= nil)

    if column_index < 0 then
        column_index = columns.Current
    end
    IM_ASSERT(column_index < columns.Columns.Size)

    local preserve_width = band(columns.Flags, ImGuiOldColumnFlags.NoPreserveWidths) == 0 and (column_index < columns.Count - 1)
    local width = preserve_width and GetColumnWidthEx(columns, column_index, columns.IsBeingResized) or 0.0

    if band(columns.Flags, ImGuiOldColumnFlags.NoForceWithinWindow) == 0 then
        offset = ImMin(offset, columns.OffMaxX - g.Style.ColumnsMinSpacing * (columns.Count - column_index))
    end
    columns.Columns.Data[column_index + 1].OffsetNorm = ImGui.GetColumnNormFromOffset(columns, offset - columns.OffMinX)

    if preserve_width then
        ImGui.SetColumnOffset(column_index + 1, offset + ImMax(g.Style.ColumnsMinSpacing, width))
    end
end

function ImGui.SetColumnWidth(column_index, width)
    local window = ImGui.GetCurrentWindowRead()
    local columns = window.DC.CurrentColumns
    IM_ASSERT(columns ~= nil)

    if column_index < 0 then
        column_index = columns.Current
    end
    ImGui.SetColumnOffset(column_index + 1, ImGui.GetColumnOffset(column_index) + width)
end

function ImGui.PushColumnClipRect(column_index)
    local window = ImGui.GetCurrentWindowRead()
    local columns = window.DC.CurrentColumns
    if column_index < 0 then
        column_index = columns.Current
    end

    local column = columns.Columns.Data[column_index + 1]
    ImGui.PushClipRect(column.ClipRect.Min, column.ClipRect.Max, false)
end

-- Get into the columns background draw command (which is generally the same draw command as before we called BeginColumns)
function ImGui.PushColumnsBackground()
    local window = ImGui.GetCurrentWindowRead()
    local columns = window.DC.CurrentColumns
    if columns.Count == 1 then
        return
    end

    -- Optimization: avoid SetCurrentChannel() + PushClipRect()
    ImRect_Copy(columns.HostBackupClipRect, window.ClipRect)
    ImGui.SetWindowClipRectBeforeSetChannel(window, columns.HostInitialClipRect)
    columns.Splitter:SetCurrentChannel(window.DrawList, 0)
end

function ImGui.PopColumnsBackground()
    local window = ImGui.GetCurrentWindowRead()
    local columns = window.DC.CurrentColumns
    if columns.Count == 1 then
        return
    end

    -- Optimization: avoid PopClipRect() + SetCurrentChannel()
    ImGui.SetWindowClipRectBeforeSetChannel(window, columns.HostBackupClipRect)
    columns.Splitter:SetCurrentChannel(window.DrawList, columns.Current + 1)
end

function ImGui.FindOrCreateColumns(window, id)
    -- We have few columns per window so for now we don't need bother much with turning this into a faster lookup.
    for _, c in window.ColumnsStorage:iter() do
        if c.ID == id then
            return c
        end
    end

    local columns = ImGuiOldColumns()
    window.ColumnsStorage:push_back(columns)
    columns.ID = id
    return columns
end

function ImGui.GetColumnsID(str_id, columns_count)
    local window = ImGui.GetCurrentWindow()

    -- Differentiate column ID with an arbitrary prefix for cases where users name their columns set the same as another widget.
    -- In addition, when an identifier isn't explicitly provided we include the number of columns in the hash to make it uniquer.
    ImGui.PushID(0x11223347 + (str_id and 0 or columns_count))
    local id = window:GetID(str_id or "columns")
    ImGui.PopID()

    return id
end

function ImGui.BeginColumns(str_id, columns_count, flags)
    if flags == nil then flags = 0 end
    local g = GImGui
    local window = ImGui.GetCurrentWindow()

    IM_ASSERT(columns_count >= 1)
    IM_ASSERT(window.DC.CurrentColumns == nil) -- Nested columns are currently not supported

    -- Acquire storage for the columns set
    local id = ImGui.GetColumnsID(str_id, columns_count)
    local columns = ImGui.FindOrCreateColumns(window, id)
    IM_ASSERT(columns.ID == id)
    columns.Current = 0
    columns.Count = columns_count
    columns.Flags = flags
    window.DC.CurrentColumns = columns
    window.DC.NavIsScrollPushableX = false -- Shortcut for NavUpdateCurrentWindowIsScrollPushableX();

    columns.HostCursorPosY = window.DC.CursorPos.y
    columns.HostCursorMaxPosX = window.DC.CursorMaxPos.x
    ImRect_Copy(columns.HostInitialClipRect, window.ClipRect)
    ImRect_Copy(columns.HostBackupParentWorkRect, window.ParentWorkRect)
    ImRect_Copy(window.ParentWorkRect, window.WorkRect)

    -- Set state for first column
    -- We aim so that the right-most column will have the same clipping width as other after being clipped by parent ClipRect
    local column_padding = g.Style.ItemSpacing.x
    local half_clip_extend_x = ImTrunc(ImMax(window.WindowPadding.x * 0.5, window.WindowBorderSize))
    local max_1 = window.WorkRect.Max.x + column_padding - ImMax(column_padding - window.WindowPadding.x, 0.0)
    local max_2 = window.WorkRect.Max.x + half_clip_extend_x
    columns.OffMinX = window.DC.Indent.x - column_padding + ImMax(column_padding - window.WindowPadding.x, 0.0)
    columns.OffMaxX = ImMax(ImMin(max_1, max_2) - window.Pos.x, columns.OffMinX + 1.0)
    columns.LineMinY = window.DC.CursorPos.y; columns.LineMaxY = window.DC.CursorPos.y

    -- Clear data if columns count changed
    if columns.Columns.Size ~= 0 and columns.Columns.Size ~= columns_count + 1 then
        columns.Columns:resize(0)
    end

    -- Initialize default widths
    columns.IsFirstFrame = (columns.Columns.Size == 0)
    if columns.Columns.Size == 0 then
        for n = 0, columns_count do
            local column = ImGuiOldColumnData()
            column.OffsetNorm = n / columns_count
            columns.Columns:push_back(column)
        end
    end

    for n = 0, columns_count - 1 do
        -- Compute clipping rectangle
        local column = columns.Columns.Data[n + 1]
        local clip_x1 = IM_ROUND(window.Pos.x + ImGui.GetColumnOffset(n))
        local clip_x2 = IM_ROUND(window.Pos.x + ImGui.GetColumnOffset(n + 1) - 1.0)
        column.ClipRect = ImRect(clip_x1, -FLT_MAX, clip_x2, FLT_MAX)
        column.ClipRect:ClipWithFull(window.ClipRect)
    end

    if columns.Count > 1 then
        columns.Splitter:Split(window.DrawList, 1 + columns.Count)
        columns.Splitter:SetCurrentChannel(window.DrawList, 1)
        ImGui.PushColumnClipRect(0)
    end

    -- We don't generally store Indent.x inside ColumnsOffset because it may be manipulated by the user.
    local offset_0 = ImGui.GetColumnOffset(columns.Current)
    local offset_1 = ImGui.GetColumnOffset(columns.Current + 1)
    local width = offset_1 - offset_0
    ImGui.PushItemWidth(width * 0.65)
    window.DC.ColumnsOffset.x = ImMax(column_padding - window.WindowPadding.x, 0.0)
    window.DC.CursorPos.x = IM_TRUNC(window.Pos.x + window.DC.Indent.x + window.DC.ColumnsOffset.x)
    window.WorkRect.Max.x = window.Pos.x + offset_1 - column_padding
    window.WorkRect.Max.y = window.ContentRegionRect.Max.y
end

function ImGui.NextColumn()
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems or window.DC.CurrentColumns == nil then
        return
    end

    local g = GImGui
    local columns = window.DC.CurrentColumns

    if columns.Count == 1 then
        window.DC.CursorPos.x = IM_TRUNC(window.Pos.x + window.DC.Indent.x + window.DC.ColumnsOffset.x)
        IM_ASSERT(columns.Current == 0)
        return
    end

    -- Next column
    columns.Current = columns.Current + 1
    if columns.Current == columns.Count then
        columns.Current = 0
    end

    ImGui.PopItemWidth()

    -- Optimization: avoid PopClipRect() + SetCurrentChannel() + PushClipRect()
    -- (which would needlessly attempt to update commands in the wrong channel, then pop or overwrite them),
    local column = columns.Columns.Data[columns.Current + 1]
    ImGui.SetWindowClipRectBeforeSetChannel(window, column.ClipRect)
    columns.Splitter:SetCurrentChannel(window.DrawList, columns.Current + 1)

    local column_padding = g.Style.ItemSpacing.x
    columns.LineMaxY = ImMax(columns.LineMaxY, window.DC.CursorPos.y)
    if columns.Current > 0 then
        -- Columns 1+ ignore IndentX (by canceling it out)
        -- FIXME-COLUMNS: Unnecessary, could be locked?
        window.DC.ColumnsOffset.x = ImGui.GetColumnOffset(columns.Current) - window.DC.Indent.x + column_padding
    else
        -- New row/line: column 0 honor IndentX.
        window.DC.ColumnsOffset.x = ImMax(column_padding - window.WindowPadding.x, 0.0)
        window.DC.IsSameLine = false
        columns.LineMinY = columns.LineMaxY
    end
    window.DC.CursorPos.x = IM_TRUNC(window.Pos.x + window.DC.Indent.x + window.DC.ColumnsOffset.x)
    window.DC.CursorPos.y = columns.LineMinY
    window.DC.CurrLineSize.x = 0.0; window.DC.CurrLineSize.y = 0.0
    window.DC.CurrLineTextBaseOffset = 0.0

    -- FIXME-COLUMNS: Share code with BeginColumns() - move code on columns setup.
    local offset_0 = ImGui.GetColumnOffset(columns.Current)
    local offset_1 = ImGui.GetColumnOffset(columns.Current + 1)
    local width = offset_1 - offset_0
    ImGui.PushItemWidth(width * 0.65)
    window.WorkRect.Max.x = window.Pos.x + offset_1 - column_padding
end

function ImGui.EndColumns()
    local g = GImGui
    local window = ImGui.GetCurrentWindow()
    local columns = window.DC.CurrentColumns
    IM_ASSERT(columns ~= nil)

    ImGui.PopItemWidth()
    if columns.Count > 1 then
        ImGui.PopClipRect()
        columns.Splitter:Merge(window.DrawList)
    end

    local flags = columns.Flags
    columns.LineMaxY = ImMax(columns.LineMaxY, window.DC.CursorPos.y)
    window.DC.CursorPos.y = columns.LineMaxY
    if band(flags, ImGuiOldColumnFlags.GrowParentContentsSize) == 0 then
        window.DC.CursorMaxPos.x = columns.HostCursorMaxPosX -- Restore cursor max pos, as columns don't grow parent
    end

    -- Draw columns borders and handle resize
    -- The IsBeingResized flag ensure we preserve pre-resize columns width so back-and-forth are not lossy
    local is_being_resized = false
    if band(flags, ImGuiOldColumnFlags.NoBorder) == 0 and not window.SkipItems then
        -- We clip Y boundaries CPU side because very long triangles are mishandled by some GPU drivers.
        local y1 = ImMax(columns.HostCursorPosY, window.ClipRect.Min.y)
        local y2 = ImMin(window.DC.CursorPos.y, window.ClipRect.Max.y)
        local dragging_column = -1
        for n = 1, columns.Count - 1 do
            local column = columns.Columns.Data[n + 1]
            local x = window.Pos.x + ImGui.GetColumnOffset(n)
            local column_id = band(columns.ID + n, 0xFFFFFFFF)
            local column_hit_hw = ImTrunc(COLUMNS_HIT_RECT_HALF_THICKNESS * g.CurrentDpiScale)
            local column_hit_rect = ImRect(ImVec2(x - column_hit_hw, y1), ImVec2(x + column_hit_hw, y2))
            if ImGui.ItemAdd(column_hit_rect, column_id, nil, ImGuiItemFlags.NoNav) then
                local hovered, held = false, false
                if band(flags, ImGuiOldColumnFlags.NoResize) == 0 then
                    local _
                    _, hovered, held = ImGui.ButtonBehavior(column_hit_rect, column_id)
                    if hovered or held then
                        ImGui.SetMouseCursor(ImGuiMouseCursor.ResizeEW)
                    end
                    if held and band(column.Flags, ImGuiOldColumnFlags.NoResize) == 0 then
                        dragging_column = n
                    end
                end

                -- Draw column
                local col = ImGui.GetColorU32(held and ImGuiCol.SeparatorActive or (hovered and ImGuiCol.SeparatorHovered or ImGuiCol.Separator))
                local xi = IM_TRUNC(x)
                window.DrawList:AddLineV(xi, y1 + 1.0, y2, col)
            end
        end

        -- Apply dragging after drawing the column lines, so our rendered lines are in sync with how items were displayed during the frame.
        if dragging_column ~= -1 then
            if not columns.IsBeingResized then
                for n = 0, columns.Count do
                    local c = columns.Columns.Data[n + 1]
                    c.OffsetNormBeforeResize = c.OffsetNorm
                end
            end
            columns.IsBeingResized = true; is_being_resized = true
            local x = GetDraggedColumnOffset(columns, dragging_column)
            ImGui.SetColumnOffset(dragging_column, x)
        end
    end
    columns.IsBeingResized = is_being_resized

    ImRect_Copy(window.WorkRect, window.ParentWorkRect)
    ImRect_Copy(window.ParentWorkRect, columns.HostBackupParentWorkRect)
    window.DC.CurrentColumns = nil
    window.DC.ColumnsOffset.x = 0.0
    window.DC.CursorPos.x = IM_TRUNC(window.Pos.x + window.DC.Indent.x + window.DC.ColumnsOffset.x)
    ImGui.NavUpdateCurrentWindowIsScrollPushableX()
end

--- @param columns_count? int
--- @param id?            string
--- @param borders?       bool
function ImGui.Columns(columns_count, id, borders)
    if columns_count == nil then columns_count = 1 end
    if borders == nil then borders = true end
    local window = ImGui.GetCurrentWindow()
    IM_ASSERT(columns_count >= 1)

    local flags = borders and 0 or ImGuiOldColumnFlags.NoBorder
    --flags = bor(flags, ImGuiOldColumnFlags.NoPreserveWidths) -- NB: Legacy behavior
    local columns = window.DC.CurrentColumns
    if columns ~= nil and columns.Count == columns_count and columns.Flags == flags then
        return
    end

    if columns ~= nil then
        ImGui.EndColumns()
    end

    if columns_count ~= 1 then
        ImGui.BeginColumns(id, columns_count, flags)
    end
end

return true -- [Roblox] ModuleScripts must return exactly one value
end

__FILES['imgui_widgets.lua'] = function()
--- Dear ImGui WIP
-- (widgets code)

--
-- Index of this file:
--
-- [SECTION] Widgets: Text, etc.
-- [SECTION] Widgets: Value helpers
-- [SECTION] Widgets: Main (Button, Image, Checkbox, RadioButton, ProgressBar, Bullet, etc.)
-- [SECTION] Widgets: Low-level Layout helpers (Spacing, Dummy, NewLine, Separator, etc.)
-- [SECTION] Widgets: ComboBox
-- [SECTION] Data Type and Data Formatting Helpers
-- [SECTION] Widgets: DragScalar, DragFloat, DragInt, etc.
-- [SECTION] Widgets: SliderScalar, SliderFloat, SliderInt, etc.
-- [SECTION] Widgets: InputScalar, InputFloat, InputInt, etc.
-- [SECTION] Widgets: InputText, InputTextMultiline
-- [SECTION] Widgets: ColorEdit, ColorPicker, ColorButton, etc.
-- [SECTION] Widgets: TreeNode, CollapsingHeader, etc.
-- [SECTION] Widgets: Selectable
-- [SECTION] Widgets: ListBox
-- [SECTION] Widgets: PlotLines, PlotHistogram
-- [SECTION] Widgets: MenuItem, BeginMenu, EndMenu, etc.
-- [SECTION] Widgets: BeginTabBar, EndTabBar, etc.
-- [SECTION] Widgets: BeginTabItem, EndTabItem, etc.
--

--- @type ImGuiContext?
local GImGui

-- Sets local `GImGui` in this file(imgui_widgets.lua).
-- This is currently only used in main code `ImGui.SetCurrentContext()`
--- @param ctx ImGuiContext?
function ImGui._SetCurrentContext_Widgets(ctx)
    GImGui = ctx
end

-------------------------------------------------------------------------------
-- Data
-------------------------------------------------------------------------------

-- Widgets
local DRAGDROP_HOLD_TO_OPEN_TIMER = 0.70 -- Time for drag-hold to activate items accepting the ImGuiButtonFlags.PressedOnDragDropHold button behavior.
local DRAG_MOUSE_THRESHOLD_FACTOR = 0.50 -- Multiplier for the default value of io.MouseDragThreshold to make DragFloat/DragInt react faster to mouse drags.

local IM_S8_MIN = -128
local IM_S8_MAX = 127
local IM_U8_MIN = 0
local IM_U8_MAX = 0xFF
local IM_S16_MIN = -32768
local IM_S16_MAX = 32767
local IM_U16_MIN = 0
local IM_U16_MAX = 0xFFFF
local IM_S32_MIN = INT_MIN -- (-2147483647 - 1), (0x80000000);
local IM_S32_MAX = INT_MAX -- (2147483647), (0x7FFFFFFF)
local IM_U32_MIN = 0
local IM_U32_MAX = UINT_MAX -- (0xFFFFFFFF)

-------------------------------------------------------------------------------
-- [SECTION] Widgets: Text, etc.
-------------------------------------------------------------------------------
-- - TextEx() [Internal]
-- - TextUnformatted()
-- - Text()
-- - TextV()
-- - TextColored()
-- - TextDisabled()
-- - TextWrapped()
-- - TextAligned()
-- - LabelText()
-- - BulletText()
-------------------------------------------------------------------------------

--- @param text      string
--- @param text_end? int
--- @param flags?    ImGuiTextFlags
local TextEx_bb = ImRect() -- [Luau] scratch, never escapes TextEx()


function ImGui.TextEx(text, text_end, flags)
    if not flags then flags = 0 end

    local g = GImGui
    local window = g.CurrentWindow
    if window.SkipItems then
        return
    end

    -- Accept null ranges
    if not text or text == "" then
        text = ""
        text_end = 1
    end

    -- Calculate length
    if text_end == nil then
        text_end = #text + 1
    end

    local dc = window.DC
    local wrap_pos_x = dc.TextWrapPos
    local wrap_enabled = (wrap_pos_x >= 0.0)
    if (text_end - 1 <= 2000) or wrap_enabled then
        -- Common case
        -- [Luau] scalar text_pos, scratch bb (ItemAdd() copies it, RenderTextWrapped() only reads it)
        local text_pos_x, text_pos_y = dc.CursorPos.x, dc.CursorPos.y + dc.CurrLineTextBaseOffset
        local wrap_width = wrap_enabled and ImGui.CalcWrapWidthForPos(dc.CursorPos, wrap_pos_x) or 0.0
        local text_size = ImGui.CalcTextSizeEx(text, 1, text_end, false, wrap_width)

        local bb = TextEx_bb
        local bb_min, bb_max = bb.Min, bb.Max
        bb_min.x = text_pos_x; bb_min.y = text_pos_y
        bb_max.x = text_pos_x + text_size.x; bb_max.y = text_pos_y + text_size.y
        ImGui.ItemSize(text_size, 0.0)
        if not ImGui.ItemAdd(bb, 0) then
            return
        end

        -- Render (we don't hide text after ## in this end-user function)
        ImGui.RenderTextWrapped(bb_min, text, text_end, wrap_width)
    else
        local text_pos = ImVec2(dc.CursorPos.x, dc.CursorPos.y + dc.CurrLineTextBaseOffset)
        -- Long text!
        -- Perform manual coarse clipping to optimize for long multi-line text
        -- - From this point we will only compute the width of lines that are visible. Optimization only available when word-wrapping is disabled.
        -- - We also don't vertically center the text within the line full height, which is unlikely to matter because we are likely the biggest and only item on the line.
        local line = 1
        local line_height = ImGui.GetTextLineHeight()
        local text_size = ImVec2(0, 0)

        -- Lines to skip (can't skip when logging text)
        local pos = ImVec2(text_pos.x, text_pos.y)
        if not g.LogEnabled then
            local lines_skippable = ImFloor((window.ClipRect.Min.y - text_pos.y) / line_height)
            if lines_skippable > 0 then
                local lines_skipped = 0
                while line < text_end and lines_skipped < lines_skippable do
                    local line_end = ImMemchr(text, "\n", line)
                    if not line_end then
                        line_end = text_end
                    end
                    if bit32.band(flags, ImGuiTextFlags.NoWidthForLargeClippedText) == 0 then
                        local line_size = ImGui.CalcTextSizeEx(text, line, line_end)
                        text_size.x = ImMax(text_size.x, line_size.x)
                    end
                    line = line_end + 1
                    lines_skipped = lines_skipped + 1
                end
                pos.y = pos.y + lines_skipped * line_height
            end
        end

        -- Lines to render
        if line < text_end then
            local line_rect = ImRect(pos, pos + ImVec2(FLT_MAX, line_height))
            while line < text_end do
                if ImGui.IsClippedEx(line_rect, 0) then
                    break
                end

                local line_end = ImMemchr(text, "\n", line)
                if not line_end then
                    line_end = text_end
                end

                local line_size = ImGui.CalcTextSizeEx(text, line, line_end)
                text_size.x = ImMax(text_size.x, line_size.x)
                ImGui.RenderText(pos, text, line, nil, false)
                line = line_end + 1
                line_rect.Min.y = line_rect.Min.y + line_height
                line_rect.Max.y = line_rect.Max.y + line_height
                pos.y = pos.y + line_height
            end

            -- Count remaining lines
            local lines_skipped = 0
            while line < text_end do
                local line_end = ImMemchr(text, "\n", line)
                if not line_end then
                    line_end = text_end
                end
                if bit32.band(flags, ImGuiTextFlags.NoWidthForLargeClippedText) == 0 then
                    local line_size = ImGui.CalcTextSizeEx(text, line, line_end)
                    text_size.x = ImMax(text_size.x, line_size.x)
                end
                line = line_end + 1
                lines_skipped = lines_skipped + 1
            end
            pos.y = pos.y + lines_skipped * line_height
        end
        text_size.y = pos.y - text_pos.y

        local bb = ImRect(text_pos, text_pos + text_size)
        ImGui.ItemSize(text_size, 0.0)
        ImGui.ItemAdd(bb, 0)
    end
end

--- @param text      string
--- @param text_end? int
function ImGui.TextUnformatted(text, text_end)
    ImGui.TextEx(text, text_end, ImGuiTextFlags.NoWidthForLargeClippedText)
end

--- @param fmt string
--- @param ... any

function ImGui.TextV(fmt, ...)
    local window = GImGui.CurrentWindow -- [Luau] inline GetCurrentWindow()
    window.WriteAccessed = true
    if window.SkipItems then
        return
    end

    local text = ImFormatString(fmt, ...)
    ImGui.TextEx(text, nil, ImGuiTextFlags.NoWidthForLargeClippedText)
end

--- @param fmt string
--- @param ... any

function ImGui.Text(fmt, ...)
    if select('#', ...) > 0 then
        ImGui.TextV(fmt, ...)
    else
        ImGui.TextEx(fmt)
    end
end

--- @param col ImVec4
--- @param fmt string
--- @param ... any
function ImGui.TextColored(col, fmt, ...)
    ImGui.PushStyleColor(ImGuiCol.Text, col)
    ImGui.TextV(fmt, ...)
    ImGui.PopStyleColor()
end

--- @param fmt string
--- @param ... any
function ImGui.TextDisabled(fmt, ...)
    local g = GImGui
    ImGui.PushStyleColor(ImGuiCol.Text, g.Style.Colors[ImGuiCol.TextDisabled])
    ImGui.TextV(fmt, ...)
    ImGui.PopStyleColor()
end

--- @param fmt string
--- @param ... any
function ImGui.TextWrapped(fmt, ...)
    local g = GImGui
    local need_backup = (g.CurrentWindow.DC.TextWrapPos < 0.0) -- Keep existing wrap position if one is already set
    if need_backup then
        ImGui.PushTextWrapPos(0.0)
    end
    ImGui.TextV(fmt, ...)
    if need_backup then
        ImGui.PopTextWrapPos()
    end
end

-- align_x: 0.0f = left, 0.5f = center, 1.0f = right.
-- size_x < 0.0f (e.g. -FLT_MIN): shortcut for GetContentRegionAvail().x
-- FIXME-WIP: Works but API is likely to be reworked. This is designed for 1 item on the line. (#7024, #9455)
--- @param align_x float
--- @param size_x  float
--- @param fmt     string
--- @param ...     any
function ImGui.TextAligned(align_x, size_x, fmt, ...)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end

    local text = ImFormatString(fmt, ...)
    local text_end = #text + 1
    local text_size = ImGui.CalcTextSize(text, text_end)
    size_x = ImGui.CalcItemSize(ImVec2(size_x, 0.0), 0.0, text_size.y).x

    local pos = ImVec2(window.DC.CursorPos.x, window.DC.CursorPos.y + window.DC.CurrLineTextBaseOffset)
    local pos_max = ImVec2(pos.x + size_x, window.ClipRect.Max.y)
    local size = ImVec2(ImMin(size_x, text_size.x), text_size.y)
    window.DC.CursorMaxPos.x = ImMax(window.DC.CursorMaxPos.x, pos.x + text_size.x)
    window.DC.IdealMaxPos.x = ImMax(window.DC.IdealMaxPos.x, pos.x + text_size.x)
    if align_x > 0.0 and text_size.x < size_x then
        pos.x = pos.x + ImTrunc((size_x - text_size.x) * align_x)
    end
    ImGui.RenderTextEllipsis(window.DrawList, pos, pos_max, pos_max.x, text, text_end, text_size)

    local backup_max_pos = ImVec2()
    ImVec2_Copy(backup_max_pos, window.DC.CursorMaxPos)
    ImGui.ItemSize(size)
    ImGui.ItemAdd(ImRect(pos, pos + size), 0)
    window.DC.CursorMaxPos.x = backup_max_pos.x -- Cancel out extending content to 'size' to use 'text_size' allowing auto-resize to function with align_x > 0.0f

    if size_x < text_size.x and ImGui.IsItemHovered(bit32.bor(ImGuiHoveredFlags.NoNavOverride, ImGuiHoveredFlags.AllowWhenDisabled, ImGuiHoveredFlags.ForTooltip)) then
        ImGui.SetTooltip("%.*s", text_end - 1, text)
    end
end

-- Add a label+text combo aligned to other label+value widgets
--- @param label string
--- @param fmt   string
--- @param ...   any
function ImGui.LabelText(label, fmt, ...)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end

    local g = GImGui
    local style = g.Style
    local w = ImGui.CalcItemWidth()

    local value_text = ImFormatString(fmt, ...)
    local value_text_end = #value_text + 1
    local value_size = ImGui.CalcTextSize(value_text, value_text_end, false)
    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)

    local pos = ImVec2()
    ImVec2_Copy(pos, window.DC.CursorPos)
    local value_bb = ImRect(pos, pos + ImVec2(w, value_size.y + style.FramePadding.y * 2))
    local total_bb = ImRect(pos, pos + ImVec2(w + ((label_size.x > 0.0) and (style.ItemInnerSpacing.x + label_size.x) or 0.0), ImMax(value_size.y, label_size.y) + style.FramePadding.y * 2))
    ImGui.ItemSize(total_bb, style.FramePadding.y)
    if not ImGui.ItemAdd(total_bb, 0) then
        return
    end

    -- Render
    ImGui.RenderTextClipped(value_bb.Min + style.FramePadding, value_bb.Max, value_text, value_text_end, value_size, ImVec2(0.0, 0.0))
    if label_size.x > 0.0 then
        ImGui.RenderText(ImVec2(value_bb.Max.x + style.ItemInnerSpacing.x, value_bb.Min.y + style.FramePadding.y), label, 1, label_end, false)
    end
end

-- Text with a little bullet aligned to the typical tree node.
--- @param fmt string
--- @param ... any
function ImGui.BulletText(fmt, ...)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end

    local g = GImGui
    local style = g.Style

    local text = ImFormatString(fmt, ...)
    local text_end = #text + 1
    local label_size = ImGui.CalcTextSize(text, text_end, false)
    local total_size = ImVec2(g.FontSize + ((label_size.x > 0.0) and (label_size.x + style.FramePadding.x * 2) or 0.0), label_size.y) -- Empty text doesn't add padding
    -- [Luau] scalar pos, no temporary ImVec2
    local pos_x, pos_y = window.DC.CursorPos.x, window.DC.CursorPos.y + window.DC.CurrLineTextBaseOffset
    ImGui.ItemSize(total_size, 0.0)
    local bb = ImRect(pos_x, pos_y, pos_x + total_size.x, pos_y + total_size.y)
    if not ImGui.ItemAdd(bb, 0) then
        return
    end

    -- Render
    local text_col = ImGui.GetColorU32(ImGuiCol.Text)
    ImGui.RenderBullet(window.DrawList, ImVec2(bb.Min.x + (style.FramePadding.x + g.FontSize * 0.5), bb.Min.y + g.FontSize * 0.5), text_col)
    ImGui.RenderText(ImVec2(bb.Min.x + (g.FontSize + style.FramePadding.x * 2), bb.Min.y + 0.0), text, 1, text_end, false)
end

-- va_list variants: identical to the varargs versions in Lua
ImGui.TextColoredV = ImGui.TextColored
ImGui.TextDisabledV = ImGui.TextDisabled
ImGui.TextWrappedV = ImGui.TextWrapped
ImGui.TextAlignedV = ImGui.TextAligned
ImGui.LabelTextV = ImGui.LabelText
ImGui.BulletTextV = ImGui.BulletText

-------------------------------------------------------------------------------
-- [SECTION] Widgets: Value helpers
-- Those is not very useful, legacy API.
-------------------------------------------------------------------------------
-- - Value()
-------------------------------------------------------------------------------

-- Value(prefix, b) / Value(prefix, int) / Value(prefix, float, float_format)
-- Lua can't tell int from float: integers without float_format print as %d, otherwise %.3f
function ImGui.Value(prefix, v, float_format)
    if type(v) == "boolean" then
        ImGui.Text("%s: %s", prefix, v and "true" or "false")
    elseif float_format then
        ImGui.Text("%s: " .. float_format, prefix, v)
    elseif math.floor(v) == v then
        ImGui.Text("%s: %d", prefix, v)
    else
        ImGui.Text("%s: %.3f", prefix, v)
    end
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: Main
-------------------------------------------------------------------------------
-- - ButtonBehavior() [Internal]
-- - Button()
-- - SmallButton()
-- - InvisibleButton()
-- - ArrowButton()
-- - CloseButton() [Internal]
-- - CollapseButton() [Internal]
-- - GetWindowScrollbarID() [Internal]
-- - GetWindowScrollbarRect() [Internal]
-- - Scrollbar() [Internal]
-- - ScrollbarEx() [Internal]
-- - Image()
-- - ImageButton()
-- - Checkbox()
-- - CheckboxFlagsT() [Internal]
-- - CheckboxFlags()
-- - RadioButton()
-- - ProgressBar()
-- - Bullet()
-- - Hyperlink()
-------------------------------------------------------------------------------

-- The ButtonBehavior() function is key to many interactions and used by many/most widgets.
-- Because we handle so many cases (keyboard/gamepad navigation, drag and drop) and many specific behavior (via ImGuiButtonFlags),
-- this code is a little complex.
-- By far the most common path is interacting with the Mouse using the default ImGuiButtonFlags.PressedOnClickRelease button behavior.
-- See the series of events below and the corresponding state reported by dear imgui:
-------------------------------------------------------------------------------
-- with PressedOnClickRelease:             return-value  IsItemHovered()  IsItemActive()  IsItemActivated()  IsItemDeactivated()  IsItemClicked()
--   Frame N+0 (mouse is outside bb)        -             -                -               -                  -                    -
--   Frame N+1 (mouse moves inside bb)      -             true             -               -                  -                    -
--   Frame N+2 (mouse button is down)       -             true             true            true               -                    true
--   Frame N+3 (mouse button is down)       -             true             true            -                  -                    -
--   Frame N+4 (mouse moves outside bb)     -             -                true            -                  -                    -
--   Frame N+5 (mouse moves inside bb)      -             true             true            -                  -                    -
--   Frame N+6 (mouse button is released)   true          true             -               -                  true                 -
--   Frame N+7 (mouse button is released)   -             true             -               -                  -                    -
--   Frame N+8 (mouse moves outside bb)     -             -                -               -                  -                    -
-------------------------------------------------------------------------------
-- with PressedOnClick:                    return-value  IsItemHovered()  IsItemActive()  IsItemActivated()  IsItemDeactivated()  IsItemClicked()
--   Frame N+2 (mouse button is down)       true          true             true            true               -                    true
--   Frame N+3 (mouse button is down)       -             true             true            -                  -                    -
--   Frame N+6 (mouse button is released)   -             true             -               -                  true                 -
--   Frame N+7 (mouse button is released)   -             true             -               -                  -                    -
-------------------------------------------------------------------------------
-- with PressedOnRelease:                  return-value  IsItemHovered()  IsItemActive()  IsItemActivated()  IsItemDeactivated()  IsItemClicked()
--   Frame N+2 (mouse button is down)       -             true             -               -                  -                    true
--   Frame N+3 (mouse button is down)       -             true             -               -                  -                    -
--   Frame N+6 (mouse button is released)   true          true             -               -                  -                    -
--   Frame N+7 (mouse button is released)   -             true             -               -                  -                    -
-------------------------------------------------------------------------------
-- with PressedOnDoubleClick:              return-value  IsItemHovered()  IsItemActive()  IsItemActivated()  IsItemDeactivated()  IsItemClicked()
--   Frame N+0 (mouse button is down)       -             true             -               -                  -                    true
--   Frame N+1 (mouse button is down)       -             true             -               -                  -                    -
--   Frame N+2 (mouse button is released)   -             true             -               -                  -                    -
--   Frame N+3 (mouse button is released)   -             true             -               -                  -                    -
--   Frame N+4 (mouse button is down)       true          true             true            true               -                    true
--   Frame N+5 (mouse button is down)       -             true             true            -                  -                    -
--   Frame N+6 (mouse button is released)   -             true             -               -                  true                 -
--   Frame N+7 (mouse button is released)   -             true             -               -                  -                    -
-------------------------------------------------------------------------------
-- Note that some combinations are supported,
-- - PressedOnDragDropHold can generally be associated with any flag.
-- - PressedOnDoubleClick can be associated by PressedOnClickRelease/PressedOnRelease, in which case the second release event won't be reported.
-------------------------------------------------------------------------------
-- The behavior of the return-value changes when ImGuiItemFlags.ButtonRepeat is set:
--                                         Repeat+                  Repeat+           Repeat+             Repeat+
--                                         PressedOnClickRelease    PressedOnClick    PressedOnRelease    PressedOnDoubleClick
-------------------------------------------------------------------------------
--   Frame N+0 (mouse button is down)       -                        true              -                   true
--   ...                                    -                        -                 -                   -
--   Frame N + RepeatDelay                  true                     true              -                   true
--   ...                                    -                        -                 -                   -
--   Frame N + RepeatDelay + RepeatRate*N   true                     true              -                   true
-------------------------------------------------------------------------------

-- - FIXME: For refactor we could output flags, incl mouse hovered vs nav keyboard vs nav triggered etc.
--   And better standardize how widgets use 'GetColor32((held && hovered) ? ... : hovered ? ...)' vs 'GetColor32(held ? ... : hovered ? ...);'
--   For mouse feedback we typically prefer the 'held && hovered' test, but for nav feedback not always. Outputting hovered=true on Activation may be misleading.
-- - Since v1.91.2 (Sept 2024) we included io.ConfigDebugHighlightIdConflicts feature.
--   One idiom which was previously valid which will now emit a warning is when using multiple overlaid ButtonBehavior()
--   with same ID and different MouseButton (see #8030). You can fix it by:
--       (1) switching to use a single ButtonBehavior() with multiple _MouseButton flags.
--    or (2) surrounding those calls with PushItemFlag(ImGuiItemFlags.AllowDuplicateId, true); ... PopItemFlag()
-- Returns (pressed, hovered, held).
--- @param bb     ImRect
--- @param id     ImGuiID
--- @param flags? ImGuiButtonFlags

function ImGui.ButtonBehavior(bb, id, flags)
    if flags == nil then flags = 0 end

    local g = GImGui

    local window = g.CurrentWindow

    -- Default behavior inherited from item flags
    -- Note that _both_ ButtonFlags and ItemFlags are valid sources, so copy one into the item_flags and only check that.
    local item_flags = (g.LastItemData.ID == id) and g.LastItemData.ItemFlags or g.CurrentItemFlags
    if bit32.band(flags, ImGuiButtonFlags.AllowOverlap) ~= 0 then
        item_flags = bit32.bor(item_flags, ImGuiItemFlags.AllowOverlap)
    end
    if bit32.band(item_flags, ImGuiItemFlags.NoFocus) ~= 0 then
        flags = bit32.bor(flags, ImGuiButtonFlags.NoFocus, ImGuiButtonFlags.NoNavFocus)
    end

    -- Default only reacts to left mouse button
    if bit32.band(flags, ImGuiButtonFlags.MouseButtonMask_) == 0 then
        flags = bit32.bor(flags, ImGuiButtonFlags.MouseButtonLeft)
    end

    -- Default behavior requires click + release inside bounding box
    if bit32.band(flags, ImGuiButtonFlags.PressedOnMask_) == 0 then
        flags = bit32.bor(flags, (bit32.band(item_flags, ImGuiItemFlags.ButtonRepeat) ~= 0) and ImGuiButtonFlags.PressedOnClick or ImGuiButtonFlags.PressedOnDefault_)
    end

    local backup_hovered_window = g.HoveredWindow
    local flatten_hovered_children = (bit32.band(flags, ImGuiButtonFlags.FlattenChildren) ~= 0) and g.HoveredWindow and g.HoveredWindow.RootWindowDockTree == window.RootWindowDockTree
    if flatten_hovered_children then
        g.HoveredWindow = window
    end

    local pressed = false
    local hovered = ImGui.ItemHoverable(bb, id, item_flags)

    -- Special mode for Drag and Drop used by openables (tree nodes, tabs etc.)
    -- where holding the button pressed for a long time while drag a payload item triggers the button.
    if g.DragDropActive then
        if (bit32.band(flags, ImGuiButtonFlags.PressedOnDragDropHold) ~= 0) and (bit32.band(g.DragDropSourceFlags, ImGuiDragDropFlags.SourceNoHoldToOpenOthers) == 0) and ImGui.IsItemHovered(ImGuiHoveredFlags.AllowWhenBlockedByActiveItem) then
            hovered = true
            ImGui.SetHoveredID(id)

            if (g.HoveredIdTimer - g.IO.DeltaTime <= DRAGDROP_HOLD_TO_OPEN_TIMER) and (g.HoveredIdTimer >= DRAGDROP_HOLD_TO_OPEN_TIMER) then
                pressed = true
                g.DragDropHoldJustPressedId = id
                ImGui.FocusWindow(window)
            end
        end

        if (g.DragDropAcceptIdPrev == id) and (bit32.band(g.DragDropAcceptFlagsPrev, ImGuiDragDropFlags.AcceptDrawAsHovered) ~= 0) then
            hovered = true
        end
    end

    if (flatten_hovered_children) then
        g.HoveredWindow = backup_hovered_window
    end

    -- Mouse handling
    local test_owner_id = (bit32.band(flags, ImGuiButtonFlags.NoTestKeyOwner) ~= 0) and ImGuiKeyOwner_Any or id
    if hovered then
        IM_ASSERT(id ~= 0) -- Lazily check inside rare path.

        -- Poll mouse buttons
        -- - 'mouse_button_clicked' is generally carried into ActiveIdMouseButton when setting ActiveId.
        -- - Technically we only need some values in one code path, but since this is gated by hovered test this is fine.
        local mouse_button_clicked = -1
        local mouse_button_released = -1
        for button = 0, 2 do
            if bit32.band(flags, bit32.lshift(ImGuiButtonFlags.MouseButtonLeft, button)) ~= 0 then -- Handle ImGuiButtonFlags.MouseButtonRight and ImGuiButtonFlags.MouseButtonMiddle here.
                if (ImGui.IsMouseClickedEx(button, ImGuiInputFlags.None, test_owner_id) and mouse_button_clicked == -1) then mouse_button_clicked = button end
                if (ImGui.IsMouseReleased(button, test_owner_id) and mouse_button_released == -1) then mouse_button_released = button end
            end
        end

        -- Process initial action
        local mods_ok = (bit32.band(flags, ImGuiButtonFlags.NoKeyModsAllowed) == 0) or (not g.IO.KeyCtrl and not g.IO.KeyShift and not g.IO.KeyAlt)
        if mods_ok then
            if mouse_button_clicked ~= -1 and g.ActiveId ~= id then
                --- @cast mouse_button_clicked ImGuiMouseButton

                if bit32.band(flags, ImGuiButtonFlags.NoSetKeyOwner) == 0 then
                    ImGui.SetKeyOwner(ImGui.MouseButtonToKey(mouse_button_clicked), id)
                end

                if bit32.band(flags, bit32.bor(ImGuiButtonFlags.PressedOnClickRelease, ImGuiButtonFlags.PressedOnClickReleaseAnywhere)) ~= 0 then
                    ImGui.SetActiveID(id, window)
                    g.ActiveIdMouseButton = mouse_button_clicked

                    if bit32.band(flags, ImGuiButtonFlags.NoNavFocus) == 0 then
                        ImGui.SetFocusID(id, window)
                        ImGui.FocusWindow(window)
                    elseif bit32.band(flags, ImGuiButtonFlags.NoFocus) == 0 then
                        ImGui.FocusWindow(window, ImGuiFocusRequestFlags.RestoreFocusedChild) -- Still need to focus and bring to front, but try to avoid losing NavId when navigating a child
                    end
                end

                if (bit32.band(flags, ImGuiButtonFlags.PressedOnClick) ~= 0) or ((bit32.band(flags, ImGuiButtonFlags.PressedOnDoubleClick) ~= 0) and g.IO.MouseClickedCount[mouse_button_clicked] == 2) then
                    pressed = true

                    if bit32.band(flags, ImGuiButtonFlags.NoHoldingActiveId) ~= 0 then
                        ImGui.ClearActiveID()
                    else
                        ImGui.SetActiveID(id, window) -- Hold on ID
                    end

                    g.ActiveIdMouseButton = mouse_button_clicked

                    if bit32.band(flags, ImGuiButtonFlags.NoNavFocus) == 0 then
                        ImGui.SetFocusID(id, window)
                        ImGui.FocusWindow(window)
                    elseif bit32.band(flags, ImGuiButtonFlags.NoFocus) == 0 then
                        ImGui.FocusWindow(window, ImGuiFocusRequestFlags.RestoreFocusedChild) -- Still need to focus and bring to front, but try to avoid losing NavId when navigating a child
                    end
                end

                if bit32.band(flags, ImGuiButtonFlags.PressedOnRelease) ~= 0 then
                    -- FIXME: Traditionally ImGuiButtonFlags.PressedOnRelease never took ActiveId. Adding it in 2026-03-20 since ImGuiButtonFlags.NoHoldingActiveId can always be added.
                    -- We don't yet perform an explicit ClearActiveID() to reduce scope of change, but this possibility could be investigated.
                    if bit32.band(flags, ImGuiButtonFlags.NoHoldingActiveId) == 0 then
                        ImGui.SetActiveID(id, window) -- Hold on ID
                    end
                    g.ActiveIdMouseButton = mouse_button_clicked
                end
            end

            if bit32.band(flags, ImGuiButtonFlags.PressedOnRelease) ~= 0 then
                if mouse_button_released ~= -1 then
                    local has_repeated_at_least_once = (bit32.band(item_flags, ImGuiItemFlags.ButtonRepeat) ~= 0) and g.IO.MouseDownDurationPrev[mouse_button_released] >= g.IO.KeyRepeatDelay -- Repeat mode trumps on release behavior

                    if not has_repeated_at_least_once then
                        pressed = true
                    end

                    if bit32.band(flags, ImGuiButtonFlags.NoNavFocus) == 0 then
                        ImGui.SetFocusID(id, window) -- FIXME: Lack of FocusWindow() call here is inconsistent with other paths. Research why.
                    end

                    ImGui.ClearActiveID()
                end
            end

            -- 'Repeat' mode acts when held regardless of _PressedOn flags (see table above).
            -- Relies on repeat logic of IsMouseClicked() but we may as well do it ourselves if we end up exposing finer RepeatDelay/RepeatRate settings.
            if g.ActiveId == id and (bit32.band(item_flags, ImGuiItemFlags.ButtonRepeat) ~= 0) then
                if g.IO.MouseDownDuration[g.ActiveIdMouseButton] > 0.0 and ImGui.IsMouseClickedEx(g.ActiveIdMouseButton, ImGuiInputFlags.Repeat, test_owner_id) then
                    pressed = true
                end
            end
        end

        if pressed and g.IO.ConfigNavCursorVisibleAuto then
            g.NavCursorVisible = false
        end
    end

    -- Keyboard/Gamepad navigation handling
    -- We report navigated and navigation-activated items as hovered but we don't set g.HoveredId to not interfere with mouse.
    if bit32.band(item_flags, ImGuiItemFlags.Disabled) == 0 then
        if g.NavId == id and g.NavCursorVisible and g.NavHighlightItemUnderNav then
            if bit32.band(flags, ImGuiButtonFlags.NoHoveredOnFocus) == 0 then
                hovered = true
            end
        end
        if g.NavActivateDownId == id then
            local nav_activated_by_code = (g.NavActivateId == id)
            local nav_activated_by_inputs = (g.NavActivatePressedId == id)
            if not nav_activated_by_inputs and bit32.band(item_flags, ImGuiItemFlags.ButtonRepeat) ~= 0 then
                -- Avoid pressing multiple keys from triggering excessive amount of repeat events
                local key1 = ImGui.GetKeyData(g, ImGuiKey.Space)
                local key2 = ImGui.GetKeyData(g, ImGuiKey.Enter)
                local key3 = ImGui.GetKeyData(g, ImGuiKey.NavGamepadActivate)
                local t1 = ImMax(ImMax(key1.DownDuration, key2.DownDuration), key3.DownDuration)
                nav_activated_by_inputs = ImGui.CalcTypematicRepeatAmount(t1 - g.IO.DeltaTime, t1, g.IO.KeyRepeatDelay, g.IO.KeyRepeatRate) > 0
            end
            if nav_activated_by_code or nav_activated_by_inputs then
                -- Set active id so it can be queried by user via IsItemActive(), equivalent of holding the mouse button.
                pressed = true
                ImGui.SetActiveID(id, window)
                g.ActiveIdSource = g.NavInputSource
                if bit32.band(flags, ImGuiButtonFlags.NoNavFocus) == 0 and bit32.band(g.NavActivateFlags, ImGuiActivateFlags.FromShortcut) == 0 then
                    ImGui.SetFocusID(id, window)
                end
                if bit32.band(g.NavActivateFlags, ImGuiActivateFlags.FromShortcut) ~= 0 then
                    g.ActiveIdFromShortcut = true
                end
            end
        end
    end

    -- Process while held
    local held = false
    if g.ActiveId == id then
        if g.ActiveIdSource == ImGuiInputSource.Mouse then
            if g.ActiveIdIsJustActivated then
                g.ActiveIdClickOffset = g.IO.MousePos - bb.Min
            end

            local mouse_button = g.ActiveIdMouseButton
            if mouse_button == -1 then
                -- Fallback for the rare situation were g.ActiveId was set programmatically or from another widget (e.g. #6304).
                ImGui.ClearActiveID()
            elseif ImGui.IsMouseDown(mouse_button, test_owner_id) then
                held = true
            else
                local release_in = hovered and (bit32.band(flags, ImGuiButtonFlags.PressedOnClickRelease) ~= 0)
                local release_anywhere = (bit32.band(flags, ImGuiButtonFlags.PressedOnClickReleaseAnywhere) ~= 0)

                if (release_in or release_anywhere) and not g.DragDropActive then
                    -- Report as pressed when releasing the mouse (this is the most common path)
                    local is_double_click_release = (bit32.band(flags, ImGuiButtonFlags.PressedOnDoubleClick) ~= 0) and g.IO.MouseReleased[mouse_button] and g.IO.MouseClickedLastCount[mouse_button] == 2

                    local is_repeating_already = (bit32.band(item_flags, ImGuiItemFlags.ButtonRepeat) ~= 0) and g.IO.MouseDownDurationPrev[mouse_button] >= g.IO.KeyRepeatDelay -- Repeat mode trumps <on release>

                    local is_button_avail_or_owned = ImGui.TestKeyOwner(ImGui.MouseButtonToKey(mouse_button), test_owner_id)

                    if not is_double_click_release and not is_repeating_already and is_button_avail_or_owned then
                        pressed = true
                    end
                end

                ImGui.ClearActiveID()
            end

            if bit32.band(flags, ImGuiButtonFlags.NoNavFocus) == 0 and g.IO.ConfigNavCursorVisibleAuto then
                g.NavCursorVisible = false
            end
        elseif g.ActiveIdSource == ImGuiInputSource.Keyboard or g.ActiveIdSource == ImGuiInputSource.Gamepad then
            -- When activated using Nav, we hold on the ActiveID until activation button is released
            if g.NavActivateDownId == id then
                held = true -- hovered == true not true as we are already likely hovered on direct activation.
            else
                ImGui.ClearActiveID()
            end
        end

        if pressed then
            g.ActiveIdHasBeenPressedBefore = true
        end
    end

    -- Activation highlight (this may be a remote activation)
    if g.NavHighlightActivatedId == id and (bit32.band(item_flags, ImGuiItemFlags.Disabled) == 0) then
        hovered = true
    end

    return pressed, hovered, held
end

--- @param label     string
--- @param size_arg? ImVec2
--- @param flags?    ImGuiButtonFlags
--- @return bool
local ButtonEx_text_min, ButtonEx_text_max = ImVec2(), ImVec2()


function ImGui.ButtonEx(label, size_arg, flags)
    if size_arg == nil then size_arg = ImVec2(0, 0) end
    if flags    == nil then flags    = 0            end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local style = g.Style
    local id = window:GetID(label)
    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)

    -- [Luau] scalar pos, no temporary ImVec2
    local pos_x, pos_y = window.DC.CursorPos.x, window.DC.CursorPos.y -- Don't modify the cursor!
    local frame_padding = style.FramePadding
    if bit32.band(flags, ImGuiButtonFlags.AlignTextBaseLine) ~= 0 and frame_padding.y < window.DC.CurrLineTextBaseOffset then -- Try to vertically align buttons that are smaller/have no padding so that text baseline matches (bit hacky, since it shouldn't be a flag)
        pos_y = pos_y + window.DC.CurrLineTextBaseOffset - frame_padding.y
    end
    local size = ImGui.CalcItemSize(size_arg, label_size.x + frame_padding.x * 2.0, label_size.y + frame_padding.y * 2.0)

    local bb = ImRect(pos_x, pos_y, pos_x + size.x, pos_y + size.y)
    ImGui.ItemSize(size, frame_padding.y)
    if not ImGui.ItemAdd(bb, id) then
        return false
    end

    local pressed, hovered, held = ImGui.ButtonBehavior(bb, id, flags)

    -- Render
    local col
    if held and hovered then
        col = ImGui.GetColorU32(ImGuiCol.ButtonActive)
    elseif hovered then
        col = ImGui.GetColorU32(ImGuiCol.ButtonHovered)
    else
        col = ImGui.GetColorU32(ImGuiCol.Button)
    end

    ImGui.RenderNavCursor(bb, id)
    ImGui.RenderFrame(bb.Min, bb.Max, col, true, style.FrameRounding)

    -- if (g.LogEnabled)
    --     LogSetNextTextDecoration("[", "]");
    local text_min, text_max = ButtonEx_text_min, ButtonEx_text_max -- [Luau] scratch: RenderTextClipped() only reads them
    text_min.x = bb.Min.x + frame_padding.x; text_min.y = bb.Min.y + frame_padding.y
    text_max.x = bb.Max.x - frame_padding.x; text_max.y = bb.Max.y - frame_padding.y
    ImGui.RenderTextClipped(text_min, text_max, label, label_end, label_size, style.ButtonTextAlign, bb)

    -- Automatically close popups
    --if (pressed && !(flags & ImGuiButtonFlags.DontClosePopups) && (window->Flags & ImGuiWindowFlags.Popup))
    --    CloseCurrentPopup();

    -- IMGUI_TEST_ENGINE_ITEM_INFO(id, label, g.LastItemData.StatusFlags);
    return pressed
end

--- @param label     string
--- @param size_arg? ImVec2
--- @return bool
function ImGui.Button(label, size_arg)
    return ImGui.ButtonEx(label, size_arg, ImGuiButtonFlags.None)
end

-- Small buttons fits within text without additional vertical spacing.
--- @param label string
--- @return bool
function ImGui.SmallButton(label)
    local g = GImGui
    local backup_padding_y = g.Style.FramePadding.y
    g.Style.FramePadding.y = 0.0
    local pressed = ImGui.ButtonEx(label, ImVec2(0, 0), ImGuiButtonFlags.AlignTextBaseLine)
    g.Style.FramePadding.y = backup_padding_y
    return pressed
end

-- Tip: use ImGui.PushID()/PopID() to push indices or pointers in the ID stack.
-- Then you can keep 'str_id' empty or the same for all your buttons (instead of creating a string based on a non-string id)
--- @param str_id   string
--- @param size_arg ImVec2
--- @param flags?   ImGuiButtonFlags
function ImGui.InvisibleButton(str_id, size_arg, flags)
    if flags == nil then flags = 0 end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    -- Ensure zero-size fits to contents
    local size = ImGui.CalcItemSize(ImVec2(size_arg.x ~= 0.0 and size_arg.x or -FLT_MIN, size_arg.y ~= 0.0 and size_arg.y or -FLT_MIN), 0.0, 0.0)

    local id = window:GetID(str_id)
    local bb = ImRect(window.DC.CursorPos, window.DC.CursorPos + size)
    ImGui.ItemSize(size)

    local item_flags = (bit32.band(flags, ImGuiButtonFlags.EnableNav) ~= 0) and ImGuiItemFlags.None or ImGuiItemFlags.NoNav
    if not ImGui.ItemAdd(bb, id, nil, item_flags) then
        return false
    end

    local pressed, hovered, held = ImGui.ButtonBehavior(bb, id, flags)
    ImGui.RenderNavCursor(bb, id)

    -- IMGUI_TEST_ENGINE_ITEM_INFO(id, str_id, g.LastItemData.StatusFlags)
    return pressed
end

--- @param str_id string
--- @param dir    ImGuiDir
--- @param size   ImVec2
--- @param flags? ImGuiButtonFlags
function ImGui.ArrowButtonEx(str_id, dir, size, flags)
    if flags == nil then flags = 0 end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local id = window:GetID(str_id)
    local bb = ImRect(window.DC.CursorPos, window.DC.CursorPos + size)
    local default_size = ImGui.GetFrameHeight()
    ImGui.ItemSize(size, (size.y >= default_size) and g.Style.FramePadding.y or -1.0)
    if not ImGui.ItemAdd(bb, id) then
        return false
    end

    local pressed, hovered, held = ImGui.ButtonBehavior(bb, id, flags)

    -- Render
    local bg_col = ImGui.GetColorU32((held and hovered) and ImGuiCol.ButtonActive or hovered and ImGuiCol.ButtonHovered or ImGuiCol.Button)
    local text_col = ImGui.GetColorU32(ImGuiCol.Text)
    ImGui.RenderNavCursor(bb, id)
    ImGui.RenderFrame(bb.Min, bb.Max, bg_col, true, g.Style.FrameRounding)
    ImGui.RenderArrow(window.DrawList, bb.Min + ImVec2(ImMax(0.0, (size.x - g.FontSize) * 0.5), ImMax(0.0, (size.y - g.FontSize) * 0.5)), text_col, dir)

    -- IMGUI_TEST_ENGINE_ITEM_INFO(id, str_id, g.LastItemData.StatusFlags)
    return pressed
end

--- @param str_id string
--- @param dir    ImGuiDir
function ImGui.ArrowButton(str_id, dir)
    local sz = ImGui.GetFrameHeight()
    return ImGui.ArrowButtonEx(str_id, dir, ImVec2(sz, sz), ImGuiButtonFlags.None)
end

-- Button to close a window
--- @param id  ImGuiID
--- @param pos ImVec2
--- @return bool
function ImGui.CloseButton(id, pos)
    local g = GImGui

    local window = g.CurrentWindow

    -- Tweak 1: Shrink hit-testing area if button covers an abnormally large proportion of the visible region. That's in order to facilitate moving the window away. (#3825)
    -- This may better be applied as a general hit-rect reduction mechanism for all widgets to ensure the area to move window is always accessible?
    local bb = ImRect(pos, pos + ImVec2(g.FontSize, g.FontSize))
    local bb_interact = ImRect()
    ImRect_Copy(bb_interact, bb)

    local area_to_visible_ratio = window.OuterRectClipped:GetArea() / bb:GetArea()
    if area_to_visible_ratio < 1.5 then
        bb_interact:Expand(ImTrunc(bb_interact:GetSize() * -0.25))
    end

    -- Tweak 2: We intentionally allow interaction when clipped so that a mechanical Alt,Right,Activate sequence can always close a window.
    -- (this isn't the common behavior of buttons, but it doesn't affect the user because navigation tends to keep items visible in scrolling layer).
    local is_clipped = not ImGui.ItemAdd(bb_interact, id)

    local pressed, hovered, held = ImGui.ButtonBehavior(bb, id)
    if is_clipped then
        return pressed
    end

    -- Render
    local bg_col
    if held then
        bg_col = ImGui.GetColorU32(ImGuiCol.ButtonActive)
    else
        bg_col = ImGui.GetColorU32(ImGuiCol.ButtonHovered)
    end

    if hovered then
        window.DrawList:AddRectFilled(bb.Min, bb.Max, bg_col)
    end

    local cross_center = bb:GetCenter() - ImVec2(0.5, 0.5)
    local cross_extent = g.FontSize * 0.5 * 0.7071 - 1
    local cross_col = ImGui.GetColorU32(ImGuiCol.Text)
    local cross_thickness = 1.0 -- FIXME-DPI
    window.DrawList:AddLine(cross_center + ImVec2(cross_extent, cross_extent), cross_center + ImVec2(-cross_extent, -cross_extent), cross_col, cross_thickness)
    window.DrawList:AddLine(cross_center + ImVec2(cross_extent, -cross_extent), cross_center + ImVec2(-cross_extent, cross_extent), cross_col, cross_thickness)

    return pressed
end

--- @return bool
function ImGui.CollapseButton(id, pos)
    local g = GImGui

    local window = g.CurrentWindow

    local bb = ImRect(pos, pos + ImVec2(g.FontSize, g.FontSize))

    local is_clipped = not ImGui.ItemAdd(bb, id)

    local pressed, hovered = ImGui.ButtonBehavior(bb, id)

    -- Render
    if hovered then
        window.DrawList:AddRectFilled(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.ButtonHovered))
    end

    if window.Collapsed then
        ImGui.RenderArrow(window.DrawList, bb.Min, ImGui.GetColorU32(ImGuiCol.Text), ImGuiDir.Right, 1)
    else
        ImGui.RenderArrow(window.DrawList, bb.Min, ImGui.GetColorU32(ImGuiCol.Text), ImGuiDir.Down, 1)
    end

    return pressed
end

--- @param window ImGuiWindow
--- @param axis   ImGuiAxis
--- @return ImGuiID
function ImGui.GetWindowScrollbarID(window, axis)
    if axis == ImGuiAxis.X then
        return window:GetID("#SCROLLX")
    else
        return window:GetID("#SCROLLY")
    end
end

-- Return scrollbar rectangle, must only be called for corresponding axis if window.ScrollbarX/Y is set.
--- @param window ImGuiWindow
--- @param axis   ImGuiAxis
--- @return ImRect
--- @nodiscard
function ImGui.GetWindowScrollbarRect(window, axis)
    local g = GImGui
    local outer_rect = window:Rect()
    local inner_rect = window.InnerRect

    -- (ScrollbarSizes.x = width of Y scrollbar; ScrollbarSizes.y = height of X scrollbar)
    local scrollbar_size = window.ScrollbarSizes[axis == ImGuiAxis.X and ImGuiAxis.Y or ImGuiAxis.X]
    IM_ASSERT(scrollbar_size >= 0.0)

    local border_size = IM_ROUND(window.WindowBorderSize * 0.5)
    local border_top = (bit32.band(window.Flags, ImGuiWindowFlags.MenuBar) ~= 0) and IM_ROUND(g.Style.FrameBorderSize * 0.5) or (bit32.band(window.Flags, ImGuiWindowFlags.NoTitleBar) ~= 0 and border_size or 0)

    if axis == ImGuiAxis.X then
        return ImRect(inner_rect.Min.x + border_size, ImMax(outer_rect.Min.y + border_size, outer_rect.Max.y - border_size - scrollbar_size), inner_rect.Max.x - border_size, outer_rect.Max.y - border_size)
    else
        return ImRect(ImMax(outer_rect.Min.x, outer_rect.Max.x - border_size - scrollbar_size), inner_rect.Min.y + border_top, outer_rect.Max.x - border_size, inner_rect.Max.y - border_size)
    end
end

--- @param window    ImGuiWindow
--- @param bb        ImRect
--- @param threshold float
--- @param axis      ImGuiAxis
function ImGui.ExtendHitBoxWhenNearViewportEdge(window, bb, threshold, axis)
    local window_rect = window.RootWindow:Rect()
    local viewport_rect = window.Viewport:GetMainRect()

    if window_rect.Min[axis] == viewport_rect.Min[axis] and bb.Min[axis] > window_rect.Min[axis] and bb.Min[axis] - threshold <= window_rect.Min[axis] then
        bb.Min[axis] = window_rect.Min[axis]
    end

    if window_rect.Max[axis] == viewport_rect.Max[axis] and bb.Max[axis] < window_rect.Max[axis] and bb.Max[axis] + threshold >= window_rect.Max[axis] then
        bb.Max[axis] = window_rect.Max[axis]
    end
end

-- Vertical/Horizontal scrollbar
-- The entire piece of code below is rather confusing because:
-- - We handle absolute seeking (when first clicking outside the grab) and relative manipulation (afterward or when clicking inside the grab)
-- - We store values as normalized ratio and in a form that allows the window content to change while we are holding on a scrollbar
-- - We handle both horizontal and vertical scrollbars, which makes the terminology not ideal.
-- Still, the code should probably be made simpler..
--- @param bb_frame            ImRect
--- @param id                  ImGuiID
--- @param axis                ImGuiAxis
--- @param p_scroll_v          number
--- @param size_visible_v      number
--- @param size_contents_v     number
--- @param draw_rounding_flags ImDrawFlags
--- @return bool   is_held
--- @return number scroll_v # Updated p_scroll_v
function ImGui.ScrollbarEx(bb_frame, id, axis, p_scroll_v, size_visible_v, size_contents_v, draw_rounding_flags)
    local g = GImGui
    local window = g.CurrentWindow
    if window.SkipItems then
        return false, p_scroll_v
    end

    local bb_frame_width = bb_frame:GetWidth()
    local bb_frame_height = bb_frame:GetHeight()
    if bb_frame_width <= 0.0 or bb_frame_height <= 0.0 then
        return false, p_scroll_v
    end

    -- When we are too small, start hiding and disabling the grab (this reduce visual noise on very small window and facilitate using the window resize grab)
    local alpha = 1.0
    if axis == ImGuiAxis.Y and bb_frame_height < bb_frame_width then
        alpha = ImSaturate(bb_frame_height / ImMax(bb_frame_width * 2.0, 1.0))
    end
    if alpha <= 0.0 then
        return false, p_scroll_v
    end

    local style = g.Style
    local allow_interaction = (alpha >= 1.0)

    local bb = ImRect()
    ImRect_Copy(bb, bb_frame)

    local padding = IM_TRUNC(ImMin(style.ScrollbarPadding, ImMin(bb_frame_width, bb_frame_height) * 0.5))
    bb:Expand(-padding)

    -- V denote the main, longer axis of the scrollbar (= height for a vertical scrollbar)
    local scrollbar_size_v
    if axis == ImGuiAxis.X then
        scrollbar_size_v = bb:GetWidth()
    else
        scrollbar_size_v = bb:GetHeight()
    end

    if scrollbar_size_v < 1.0 then
        return false, p_scroll_v
    end

    -- Calculate the height of our grabbable box. It generally represent the amount visible (vs the total scrollable amount)
    -- But we maintain a minimum size in pixel to allow for the user to still aim inside.
    IM_ASSERT(ImMax(size_contents_v, size_visible_v) > 0.0) -- Adding this assert to check if the ImMax(XXX,1.0f) is still needed. PLEASE CONTACT ME if this triggers.
    local win_size_v = ImMax(ImMax(size_contents_v, size_visible_v), 1)
    local grab_h_minsize = ImMin(bb:GetSize()[axis], style.GrabMinSize)
    local grab_h_pixels = ImTrunc(ImClamp(scrollbar_size_v * (size_visible_v / win_size_v), grab_h_minsize, scrollbar_size_v))
    local grab_h_norm = grab_h_pixels / scrollbar_size_v

    -- As a special thing, we allow scrollbar near the edge of a screen/viewport to be reachable with mouse at the extreme edge (#9276)
    local bb_hit = ImRect()
    ImRect_Copy(bb_hit, bb_frame)
    ImGui.ExtendHitBoxWhenNearViewportEdge(window, bb_hit, g.Style.WindowBorderSize, ImGuiAxis.X + ImGuiAxis.Y - axis) -- swap axis here

    -- Handle input right away. None of the code of Begin() is relying on scrolling position before calling Scrollbar().
    ImGui.ItemAdd(bb_frame, id, nil, ImGuiItemFlags.NoNav)
    local pressed, hovered, held = ImGui.ButtonBehavior(bb_hit, id, ImGuiButtonFlags.NoNavFocus)

    local scroll_max = ImMax(1, size_contents_v - size_visible_v)
    local scroll_ratio = ImSaturate(p_scroll_v / scroll_max)
    local grab_v_norm = scroll_ratio * (scrollbar_size_v - grab_h_pixels) / scrollbar_size_v -- Grab position in normalized space
    if held and allow_interaction and grab_h_norm < 1.0 then
        local scrollbar_pos_v = bb.Min[axis]
        local mouse_pos_v = g.IO.MousePos[axis]

        -- Click position in scrollbar normalized space (0.0f->1.0f)
        local clicked_v_norm = ImSaturate((mouse_pos_v - scrollbar_pos_v) / scrollbar_size_v)

        local held_dir
        if clicked_v_norm < grab_v_norm then
            held_dir = -1
        elseif clicked_v_norm > grab_v_norm + grab_h_norm then
            held_dir = 1
        else
            held_dir = 0
        end
        if g.ActiveIdIsJustActivated then
            -- On initial click when held_dir == 0 (clicked over grab): calculate the distance between mouse and the center of the grab
            local scroll_to_clicked_location = (g.IO.ConfigScrollbarScrollByPage == false) or g.IO.KeyShift or held_dir == 0

            if scroll_to_clicked_location then
                g.ScrollbarSeekMode = 0
            else
                g.ScrollbarSeekMode = held_dir
            end

            if held_dir == 0 and not g.IO.KeyShift then
                g.ScrollbarClickDeltaToGrabCenter = clicked_v_norm - grab_v_norm - grab_h_norm * 0.5
            else
                g.ScrollbarClickDeltaToGrabCenter = 0.0
            end
        end

        -- Apply scroll (p_scroll_v will generally point on one member of window.Scroll)
        -- It is ok to modify Scroll here because we are being called in Begin() after the calculation of ContentSize and before setting up our starting position
        if g.ScrollbarSeekMode == 0 then
            -- Absolute seeking
            scroll_v_norm = ImSaturate((clicked_v_norm - g.ScrollbarClickDeltaToGrabCenter - grab_h_norm * 0.5) / (1.0 - grab_h_norm))
            p_scroll_v = scroll_v_norm * scroll_max
        else
            -- Page by page
            if ImGui.IsMouseClickedEx(ImGuiMouseButton.Left, ImGuiInputFlags.Repeat) and held_dir == g.ScrollbarSeekMode then
                local page_dir
                if g.ScrollbarSeekMode > 0.0 then
                    page_dir = 1.0
                else
                    page_dir = -1.0
                end
                p_scroll_v = ImClamp(p_scroll_v + page_dir * size_visible_v, 0, scroll_max)
            end
        end

        -- Update values for rendering
        scroll_ratio = ImSaturate(p_scroll_v / scroll_max)
        grab_v_norm = scroll_ratio * (scrollbar_size_v - grab_h_pixels) / scrollbar_size_v

        -- Update distance to grab now that we have seek'ed and saturated
        --if (seek_absolute)
        --    g.ScrollbarClickDeltaToGrabCenter = clicked_v_norm - grab_v_norm - grab_h_norm * 0.5f;
    end

    -- Render
    local bg_col = ImGui.GetColorU32(ImGuiCol.ScrollbarBg)
    local grab_col
    if held then
        grab_col = ImGui.GetColorU32(ImGuiCol.ScrollbarGrabActive, alpha)
    elseif hovered then
        grab_col = ImGui.GetColorU32(ImGuiCol.ScrollbarGrabHovered, alpha)
    else
        grab_col = ImGui.GetColorU32(ImGuiCol.ScrollbarGrab, alpha)
    end
    window.DrawList:AddRectFilled(bb_frame.Min, bb_frame.Max, bg_col, window.WindowRounding, draw_rounding_flags)
    local grab_rect
    if axis == ImGuiAxis.X then
        local x1 = ImLerp(bb.Min.x, bb.Max.x, grab_v_norm)
        grab_rect = ImRect(x1, bb.Min.y, x1 + grab_h_pixels, bb.Max.y)
    else
        local y1 = ImLerp(bb.Min.y, bb.Max.y, grab_v_norm)
        grab_rect = ImRect(bb.Min.x, y1, bb.Max.x, y1 + grab_h_pixels)
    end

    window.DrawList:AddRectFilled(grab_rect.Min, grab_rect.Max, grab_col, style.ScrollbarRounding)

    return held, p_scroll_v
end

--- @param axis ImGuiAxis
function ImGui.Scrollbar(axis)
    local g = GImGui
    local window = g.CurrentWindow
    local id = ImGui.GetWindowScrollbarID(window, axis)

    -- Calculate scrollbar bounding box
    local bb = ImGui.GetWindowScrollbarRect(window, axis)
    local rounding_corners = ImGui.CalcRoundingFlagsForRectInRect(bb, window:Rect(), g.Style.WindowBorderSize)
    local k = (axis == ImGuiAxis.X) and "x" or "y" -- [Luau] named key: ImVec2[axis] goes through IM_VEC2.__index
    local size_visible = window.InnerRect.Max[k] - window.InnerRect.Min[k]
    local size_contents = window.ContentSize[k] + window.WindowPadding[k] * 2.0
    local scroll = window.Scroll[k]
    local held
    held, scroll = ImGui.ScrollbarEx(bb, id, axis, scroll, size_visible, size_contents, rounding_corners)
    window.Scroll[k] = scroll
end

-- - Read about ImTextureID/ImTextureRef here: https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples
-- - 'uv0' and 'uv1' are texture coordinates. Read about them from the same link above.
--- @param tex_ref    ImTextureRef
--- @param image_size ImVec2
--- @param uv0?       ImVec2
--- @param uv1?       ImVec2
--- @param bg_col?    ImVec4
--- @param tint_col?  ImVec4
function ImGui.ImageWithBg(tex_ref, image_size, uv0, uv1, bg_col, tint_col)
    if uv0      == nil then uv0      = ImVec2(0, 0)       end
    if uv1      == nil then uv1      = ImVec2(1, 1)       end
    if bg_col   == nil then bg_col   = ImVec4(0, 0, 0, 0) end
    if tint_col == nil then tint_col = ImVec4(1, 1, 1, 1) end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end

    local g = GImGui
    local padding = ImVec2(g.Style.ImageBorderSize, g.Style.ImageBorderSize)
    local bb = ImRect(window.DC.CursorPos, window.DC.CursorPos + image_size + padding * 2.0)
    ImGui.ItemSize(bb)
    if not ImGui.ItemAdd(bb, 0) then
        return
    end

    -- Render
    local rounding = g.Style.ImageRounding
    if bg_col.w > 0.0 then
        window.DrawList:AddRectFilled(bb.Min + padding, bb.Max - padding, ImGui.GetColorU32(bg_col), rounding)
    end
    if rounding > 0.0 then
        window.DrawList:AddImageRounded(tex_ref, bb.Min + padding, bb.Max - padding, uv0, uv1, ImGui.GetColorU32(tint_col), rounding)
    else
        window.DrawList:AddImage(tex_ref, bb.Min + padding, bb.Max - padding, uv0, uv1, ImGui.GetColorU32(tint_col))
    end
    if g.Style.ImageBorderSize > 0.0 then
        window.DrawList:AddRect(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.Border), rounding, g.Style.ImageBorderSize, ImDrawFlags.None)
    end
end

--- @param tex_ref    ImTextureRef
--- @param image_size ImVec2
--- @param uv0?       ImVec2
--- @param uv1?       ImVec2
function ImGui.Image(tex_ref, image_size, uv0, uv1)
    ImGui.ImageWithBg(tex_ref, image_size, uv0, uv1)
end

--- @param id         ImGuiID
--- @param tex_ref    ImTextureRef
--- @param image_size ImVec2
--- @param uv0        ImVec2
--- @param uv1        ImVec2
--- @param bg_col     ImVec4
--- @param tint_col   ImVec4
--- @param flags?     ImGuiButtonFlags
function ImGui.ImageButtonEx(id, tex_ref, image_size, uv0, uv1, bg_col, tint_col, flags)
    if flags == nil then flags = 0 end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local padding = g.Style.FramePadding
    local bb = ImRect(window.DC.CursorPos, window.DC.CursorPos + image_size + padding * 2.0)
    ImGui.ItemSize(bb)
    if not ImGui.ItemAdd(bb, id) then
        return false
    end

    local pressed, hovered, held = ImGui.ButtonBehavior(bb, id, flags)

    -- Render
    local col = ImGui.GetColorU32((held and hovered) and ImGuiCol.ButtonActive or hovered and ImGuiCol.ButtonHovered or ImGuiCol.Button)
    ImGui.RenderNavCursor(bb, id)
    ImGui.RenderFrame(bb.Min, bb.Max, col, true, g.Style.FrameRounding)
    if bg_col.w > 0.0 then
        window.DrawList:AddRectFilled(bb.Min + padding, bb.Max - padding, ImGui.GetColorU32(bg_col))
    end
    local image_rounding = ImMax(g.Style.FrameRounding - ImMax(padding.x, padding.y), g.Style.ImageRounding)
    if image_rounding > 0.0 then
        window.DrawList:AddImageRounded(tex_ref, bb.Min + padding, bb.Max - padding, uv0, uv1, ImGui.GetColorU32(tint_col), image_rounding)
    else
        window.DrawList:AddImage(tex_ref, bb.Min + padding, bb.Max - padding, uv0, uv1, ImGui.GetColorU32(tint_col))
    end

    return pressed
end

-- - ImageButton() adds style.FramePadding*2.0f to provided size. This is in order to facilitate fitting an image in a button.
-- - ImageButton() draws a background based on regular Button() color + optionally an inner background if specified. (#8165) -- FIXME: Maybe that's not the best design?
--- @param str_id     string
--- @param tex_ref    ImTextureRef
--- @param image_size ImVec2
--- @param uv0        ImVec2
--- @param uv1        ImVec2
--- @param bg_col     ImVec4
--- @param tint_col   ImVec4
function ImGui.ImageButton(str_id, tex_ref, image_size, uv0, uv1, bg_col, tint_col)
    local g = GImGui
    local window = g.CurrentWindow
    if window.SkipItems then
        return false
    end

    return ImGui.ImageButtonEx(window:GetID(str_id), tex_ref, image_size, uv0, uv1, bg_col, tint_col)
end

--- @param label string
--- @param v     bool
--- @return bool is_pressed
--- @return bool is_checked # The updated `v` passed in

function ImGui.Checkbox(label, v)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false, v
    end

    local g = GImGui
    local style = g.Style
    local id = window:GetID(label)
    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)

    local square_sz = g.FontSize + style.FramePadding.y * 2.0 -- [Luau] inline GetFrameHeight()
    local pos_x, pos_y = window.DC.CursorPos.x, window.DC.CursorPos.y -- [Luau] scalar pos, no temporary ImVec2

    local total_width
    if label_size.x > 0.0 then
        total_width = square_sz + style.ItemInnerSpacing.x + label_size.x
    else
        total_width = square_sz
    end
    local total_bb = ImRect(pos_x, pos_y, pos_x + total_width, pos_y + (label_size.y + style.FramePadding.y * 2.0))
    ImGui.ItemSize(total_bb, style.FramePadding.y)
    local is_visible = ImGui.ItemAdd(total_bb, id)
    local is_multi_select = (bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.IsMultiSelect) ~= 0)
    if not is_visible then
        if not is_multi_select or not g.BoxSelectState.UnclipMode or not g.BoxSelectState.UnclipRect:Overlaps(total_bb) then -- Extra layer of "no logic clip" for box-select support
            -- IMGUI_TEST_ENGINE_ITEM_INFO(id, label, g.LastItemData.StatusFlags | ImGuiItemStatusFlags_Checkable | (*v ? ImGuiItemStatusFlags_Checked : 0))
            return false, v
        end
    end

    -- Range-Selection/Multi-selection support (header)
    local checked = v
    if is_multi_select then
        -- TODO: MultiSelectItemHeader()
    end

    local pressed, hovered, held = ImGui.ButtonBehavior(total_bb, id)

    -- Range-Selection/Multi-selection support (footer)
    if is_multi_select then
        -- TODO: MultiSelectItemFooter()
    elseif pressed then
        checked = not checked
    end

    if v ~= checked then
        v = checked
        pressed = true -- return value
        ImGui.MarkItemEdited(id)
    end

    local check_bb = ImRect(pos_x, pos_y, pos_x + square_sz, pos_y + square_sz)
    local mixed_value = (bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.MixedValue) ~= 0)
    if is_visible then
        ImGui.RenderNavCursor(total_bb, id)

        local bg_col = ImGui.GetColorU32((held and hovered) and ImGuiCol.FrameBgActive or (hovered and ImGuiCol.FrameBgHovered or ((mixed_value or checked) and ImGuiCol.CheckboxSelectedBg or ImGuiCol.FrameBg)))
        local check_col = ImGui.GetColorU32(ImGuiCol.CheckMark)
        ImGui.RenderFrame(check_bb.Min, check_bb.Max, bg_col, true, style.FrameRounding)

        if mixed_value then
            -- Undocumented tristate/mixed/indeterminate checkbox (#2644)
            -- This may seem awkwardly designed because the aim is to make ImGuiItemFlags.MixedValue supported by all widgets (not just checkbox)
            local pad_val = ImMax(1.0, IM_TRUNC(square_sz / 3.6))
            local pad = ImVec2(pad_val, pad_val)
            window.DrawList:AddRectFilled(check_bb.Min + pad, check_bb.Max - pad, check_col, style.FrameRounding)
        elseif v then
            local pad = ImMax(1.0, IM_TRUNC(square_sz / 6.0))
            ImGui.RenderCheckMark(window.DrawList, check_bb.Min + ImVec2(pad, pad), check_col, square_sz - pad * 2.0)
        end
    end

    if g.LogEnabled then
        -- ImGui.LogRenderedText(label_pos, mixed_value and "[~]" or (v and "[x]" or "[ ]"))
    end

    if is_visible and label_size.x > 0.0 then
        local label_pos = ImVec2(check_bb.Max.x + style.ItemInnerSpacing.x, check_bb.Min.y + style.FramePadding.y) -- [Luau] only built when used
        ImGui.RenderText(label_pos, label, 1, label_end, false)
    end

    -- IMGUI_TEST_ENGINE_ITEM_INFO(id, label, g.LastItemData.StatusFlags | ImGuiItemStatusFlags_Checkable | (*v ? ImGuiItemStatusFlags_Checked : 0))
    return pressed, v
end

--- @param label       string
--- @param flags       int
--- @param flags_value int
--- @return bool is_pressed
--- @return int  flags_new  # Updated `flags`
function ImGui.CheckboxFlags(label, flags, flags_value)
    local all_on = bit32.band(flags, flags_value) == flags_value
    local any_on = bit32.band(flags, flags_value) ~= 0
    local pressed
    if not all_on and any_on then
        local g = GImGui
        g.NextItemData.ItemFlagsSet = bit32.bor(g.NextItemData.ItemFlagsSet, ImGuiItemFlags.MixedValue)
        pressed, all_on = ImGui.Checkbox(label, all_on)
    else
        pressed, all_on = ImGui.Checkbox(label, all_on)
    end
    if pressed then
        if all_on then
            flags = bit32.bor(flags, flags_value)
        else
            flags = bit32.band(flags, bit32.bnot(flags_value))
        end
    end

    return pressed, flags
end
ImGui.CheckboxFlagsT = ImGui.CheckboxFlags

--- @param label  string
--- @param active bool
--- @return bool is_pressed
function ImGui.RadioButtonEx(label, active)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local style = g.Style
    local id = window:GetID(label)
    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)

    local square_sz = g.FontSize + style.FramePadding.y * 2.0 -- [Luau] inline GetFrameHeight()
    local pos_x, pos_y = window.DC.CursorPos.x, window.DC.CursorPos.y -- [Luau] scalar pos, no temporary ImVec2
    local check_bb = ImRect(pos_x, pos_y, pos_x + square_sz, pos_y + square_sz)
    local total_bb = ImRect(pos_x, pos_y, pos_x + (square_sz + (label_size.x > 0.0 and style.ItemInnerSpacing.x + label_size.x or 0.0)), pos_y + (label_size.y + style.FramePadding.y * 2.0))
    ImGui.ItemSize(total_bb, style.FramePadding.y)
    if not ImGui.ItemAdd(total_bb, id) then
        return false
    end

    local center = check_bb:GetCenter()
    center.x = IM_ROUND(center.x)
    center.y = IM_ROUND(center.y)
    local radius = (square_sz - 1.0) * 0.5

    local pressed, hovered, held = ImGui.ButtonBehavior(total_bb, id)
    if (pressed) then
        ImGui.MarkItemEdited(id)
    end

    ImGui.RenderNavCursor(total_bb, id)
    local num_segment = window.DrawList:_CalcCircleAutoSegmentCount(radius)
    local col
    if held and hovered then
        col = ImGui.GetColorU32(ImGuiCol.FrameBgActive)
    else
        if hovered then
            col = ImGui.GetColorU32(ImGuiCol.FrameBgHovered)
        else
            col = ImGui.GetColorU32(ImGuiCol.FrameBg)
        end
    end
    window.DrawList:AddCircleFilled(center, radius, col, num_segment)
    if active then
        local pad = ImMax(1.0, IM_TRUNC(square_sz / 6.0))
        window.DrawList:AddCircleFilled(center, radius - pad, ImGui.GetColorU32(ImGuiCol.CheckMark))
    end
    if style.FrameBorderSize > 0.0 then
        window.DrawList:AddCircle(center + ImVec2(1, 1), radius, ImGui.GetColorU32(ImGuiCol.BorderShadow), num_segment, style.FrameBorderSize)
        window.DrawList:AddCircle(center, radius, ImGui.GetColorU32(ImGuiCol.Border), num_segment, style.FrameBorderSize)
    end
    local label_pos = ImVec2(check_bb.Max.x + style.ItemInnerSpacing.x, check_bb.Min.y + style.FramePadding.y)
    if g.LogEnabled then
        -- ImGui.LogRenderedText(label_pos, active and "(x)" or "( )")
    end
    if label_size.x > 0.0 then
        ImGui.RenderText(label_pos, label, 1, label_end, false)
    end

    return pressed
end

-- `rawequal` is used here to check if v == v_button
--- @param label    string
--- @param v        any
--- @param v_button any
--- @return bool is_pressed
--- @return any  v          # Updated v
function ImGui.RadioButton(label, v, v_button)
    local pressed = ImGui.RadioButtonEx(label, rawequal(v, v_button))
    if pressed then
        v = v_button
    end
    return pressed, v
end

-- size_arg (for each axis) < 0.0f: align to end, 0.0f: auto, > 0.0f: specified size
--- @param fraction  float
--- @param size_arg? ImVec2
--- @param overlay?  string
function ImGui.ProgressBar(fraction, size_arg, overlay)
    if size_arg == nil then size_arg = ImVec2(-FLT_MIN, 0) end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end

    local g = GImGui
    local style = g.Style

    local pos = ImVec2()
    ImVec2_Copy(pos, window.DC.CursorPos)
    local size = ImGui.CalcItemSize(size_arg, ImGui.CalcItemWidth(), g.FontSize + style.FramePadding.y * 2.0)
    local bb = ImRect(pos, pos + size)
    ImGui.ItemSize(size, style.FramePadding.y)
    if not ImGui.ItemAdd(bb, 0) then
        return
    end

    -- Fraction < 0.0f will display an indeterminate progress bar animation
    -- The value must be animated along with time, so e.g. passing '-1.0f * ImGui.GetTime()' as fraction works.
    local is_indeterminate = (fraction < 0.0)
    if not is_indeterminate then
        fraction = ImSaturate(fraction)
    end

    -- Out of courtesy we accept a NaN fraction without crashing
    local fill_n0 = 0.0
    local fill_n1 = (fraction == fraction) and fraction or 0.0

    if is_indeterminate then
        local fill_width_n = 0.2
        fill_n0 = ImFmod(-fraction, 1.0) * (1.0 + fill_width_n) - fill_width_n
        fill_n1 = ImSaturate(fill_n0 + fill_width_n)
        fill_n0 = ImSaturate(fill_n0)
    end

    -- Render
    ImGui.RenderFrame(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.FrameBg), true, style.FrameRounding)
    bb:Expand(ImVec2(-style.FrameBorderSize, -style.FrameBorderSize))

    local fill_x0 = ImLerp(bb.Min.x, bb.Max.x, fill_n0)
    local fill_x1 = ImLerp(bb.Min.x, bb.Max.x, fill_n1)
    if fill_x0 < fill_x1 then
        ImGui.RenderRectFilledInRangeH(window.DrawList, bb, ImGui.GetColorU32(ImGuiCol.PlotHistogram), fill_x0, fill_x1, style.FrameRounding)
    end

    -- Default displaying the fraction as percentage string, but user can override it
    -- Don't display text for indeterminate bars by default
    if not is_indeterminate or overlay ~= nil then
        if overlay == nil then
            overlay = ImFormatString("%.0f%%", fraction * 100 + 0.01)
        end

        local overlay_size = ImGui.CalcTextSize(overlay, nil)
        if overlay_size.x > 0.0 then
            local text_x = is_indeterminate and ((bb.Min.x + bb.Max.x - overlay_size.x) * 0.5) or (fill_x1 + style.ItemSpacing.x)
            ImGui.RenderTextClipped(ImVec2(ImClamp(text_x, bb.Min.x, bb.Max.x - overlay_size.x - style.ItemInnerSpacing.x), bb.Min.y), bb.Max, overlay, nil, overlay_size, ImVec2(0.0, 0.5), bb)
        end
    end
end

function ImGui.Bullet()
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end

    local g = GImGui
    local style = g.Style
    local line_height = ImMax(ImMin(window.DC.CurrLineSize.y, g.FontSize + style.FramePadding.y * 2), g.FontSize)
    local bb = ImRect(window.DC.CursorPos, window.DC.CursorPos + ImVec2(g.FontSize, line_height))
    ImGui.ItemSize(bb)
    if not ImGui.ItemAdd(bb, 0) then
        ImGui.SameLine(0, style.FramePadding.x * 2)
        return
    end

    -- Render and stay on same line
    local text_col = ImGui.GetColorU32(ImGuiCol.Text)
    ImGui.RenderBullet(window.DrawList, bb.Min + ImVec2(style.FramePadding.x + g.FontSize * 0.5, line_height * 0.5), text_col)
    ImGui.SameLine(0, style.FramePadding.x * 2.0)
end

-- This is provided as a convenience for being an often requested feature.
-- FIXME-STYLE: we delayed adding as there is a larger plan to revamp the styling system.
-- Because of this we currently don't provide many styling options for this widget
-- (e.g. hovered/active colors are automatically inferred from a single color).
--- @param label string
function ImGui.TextLink(label)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local id = window:GetID(label)
    local label_end = ImGui.FindRenderedTextEnd(label)

    local pos = ImVec2(window.DC.CursorPos.x, window.DC.CursorPos.y + window.DC.CurrLineTextBaseOffset)
    local size = ImGui.CalcTextSize(label, label_end, false)
    local bb = ImRect(pos, pos + size)
    ImGui.ItemSize(size, 0.0)
    if not ImGui.ItemAdd(bb, id) then
        return false
    end

    local pressed, hovered, held = ImGui.ButtonBehavior(bb, id)
    ImGui.RenderNavCursor(bb, id)

    if hovered then
        ImGui.SetMouseCursor(ImGuiMouseCursor.Hand)
    end

    local text_colf = ImVec4()
    ImVec4_Copy(text_colf, g.Style.Colors[ImGuiCol.TextLink])
    local line_colf = ImVec4()
    ImVec4_Copy(line_colf, text_colf)
    do
        -- FIXME-STYLE: Read comments above. This widget is NOT written in the same style as some earlier widgets,
        -- as we are currently experimenting/planning a different styling system.
        local h, s, v = ImGui.ColorConvertRGBtoHSV(text_colf.x, text_colf.y, text_colf.z)
        if held or hovered then
            v = ImSaturate(v + (held and 0.4 or 0.3))
            h = ImFmod(h + 0.02, 1.0)
        end
        text_colf.x, text_colf.y, text_colf.z = ImGui.ColorConvertHSVtoRGB(h, s, v)
        v = ImSaturate(v - 0.20)
        line_colf.x, line_colf.y, line_colf.z = ImGui.ColorConvertHSVtoRGB(h, s, v)
    end

    local line_y = bb.Max.y + ImFloor(g.FontBaked.Descent * g.FontBakedScale * 0.20)
    window.DrawList:AddLineH(bb.Min.x, bb.Max.x, line_y, ImGui.GetColorU32(line_colf), 1.0 * ImTrunc(g.Style._MainScale)) -- FIXME-TEXT: Underline mode -- FIXME-DPI

    ImGui.PushStyleColor(ImGuiCol.Text, ImGui.GetColorU32(text_colf))
    ImGui.RenderText(bb.Min, label, 1, label_end, false)
    ImGui.PopStyleColor()

    -- IMGUI_TEST_ENGINE_ITEM_INFO(id, label, g.LastItemData.StatusFlags)
    return pressed
end

--- @param label string
--- @param url   string
function ImGui.TextLinkOpenURL(label, url)
    local g = GImGui
    if url == nil then
        url = label
    end
    local pressed = ImGui.TextLink(label)
    if pressed and g.PlatformIO.Platform_OpenInShellFn ~= nil then
        g.PlatformIO.Platform_OpenInShellFn(g, url)
    end

    ImGui.SetItemTooltip(ImGui.LocalizeGetMsg(ImGuiLocKey.OpenLink_s), url) -- It is more reassuring for user to _always_ display URL when it is the same as the label.

    if ImGui.BeginPopupContextItem() then
        if ImGui.MenuItem(ImGui.LocalizeGetMsg(ImGuiLocKey.CopyLink)) then
            ImGui.SetClipboardText(url)
        end
        ImGui.EndPopup()
    end

    return pressed
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: Low-level Layout helpers
-------------------------------------------------------------------------------
-- - Spacing()
-- - Dummy()
-- - NewLine()
-- - AlignTextToFramePadding()
-- - SeparatorEx() [Internal]
-- - Separator()
-------------------------------------------------------------------------------

local LAYOUT_ZERO_SIZE = ImVec2(0, 0) -- [Luau] shared read-only: ItemSize() only reads it
local LayoutHelpers_size = ImVec2()   -- [Luau] scratch for ItemSize() arguments

function ImGui.Spacing()
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end
    ImGui.ItemSize(LAYOUT_ZERO_SIZE)
end

--- @param size ImVec2
function ImGui.Dummy(size)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end

    local cursor = window.DC.CursorPos
    local bb = ImRect(cursor.x, cursor.y, cursor.x + size.x, cursor.y + size.y) -- [Luau] no temporary ImVec2
    ImGui.ItemSize(size)
    ImGui.ItemAdd(bb, 0)
end

function ImGui.NewLine()
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end

    local g = GImGui
    local backup_layout_type = window.DC.LayoutType
    window.DC.LayoutType = ImGuiLayoutType.Vertical
    window.DC.IsSameLine = false

    if window.DC.CurrLineSize.y > 0.0 then -- In the event that we are on a line with items that is smaller that FontSize high, we will preserve its height.
        ImGui.ItemSize(ImVec2(0, 0))
    else
        ImGui.ItemSize(ImVec2(0.0, g.FontSize))
    end

    window.DC.LayoutType = backup_layout_type
end

function ImGui.AlignTextToFramePadding()
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end

    local g = GImGui
    window.DC.CurrLineSize.y = ImMax(window.DC.CurrLineSize.y, g.FontSize + g.Style.FramePadding.y * 2)
    window.DC.CurrLineTextBaseOffset = ImMax(window.DC.CurrLineTextBaseOffset, g.Style.FramePadding.y)
end

-- Horizontal/vertical separating line
-- FIXME: Surprisingly, this seemingly trivial widget is a victim of many different legacy/tricky layout issues.
-- Note how thickness == 1.0f is handled specifically as not moving CursorPos by 'thickness', but other values are.
--- @param flags     ImGuiSeparatorFlags
--- @param thickness float
function ImGui.SeparatorEx(flags, thickness)
    if thickness == nil then thickness = 1.0 end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end

    local g = GImGui
    IM_ASSERT(ImIsPowerOfTwo(bit32.band(flags, bit32.bor(ImGuiSeparatorFlags.Horizontal, ImGuiSeparatorFlags.Vertical)))) -- Check that only 1 option is selected
    IM_ASSERT(thickness > 0.0)

    if bit32.band(flags, ImGuiSeparatorFlags.Vertical) ~= 0 then
        -- Vertical separator, for menu bars (use current line height).
        local y1 = window.DC.CursorPos.y
        local y2 = window.DC.CursorPos.y + window.DC.CurrLineSize.y
        local bb = ImRect(window.DC.CursorPos.x, y1, window.DC.CursorPos.x + thickness, y2) -- [Luau] no temporary ImVec2
        local item_size = LayoutHelpers_size; item_size.x = thickness; item_size.y = 0.0
        ImGui.ItemSize(item_size)
        if not ImGui.ItemAdd(bb, 0) then
            return
        end

        -- Draw
        window.DrawList:AddRectFilled(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.Separator))
        if g.LogEnabled then
            ImGui.LogText(" |")
        end
    elseif bit32.band(flags, ImGuiSeparatorFlags.Horizontal) ~= 0 then
        -- Horizontal Separator
        local x1 = window.DC.CursorPos.x
        local x2 = window.WorkRect.Max.x

        -- Preserve legacy behavior inside Columns()
        -- Before Tables API happened, we relied on Separator() to span all columns of a Columns() set.
        -- We currently don't need to provide the same feature for tables because tables naturally have border features.
        local columns = (bit32.band(flags, ImGuiSeparatorFlags.SpanAllColumns) ~= 0) and window.DC.CurrentColumns or nil
        if columns then
            x1 = window.Pos.x + window.DC.Indent.x -- Used to be Pos.x before 2023/10/03
            x2 = window.Pos.x + window.Size.x
            ImGui.PushColumnsBackground()
        end

        -- We don't provide our width to the layout so that it doesn't get feed back into AutoFit
        -- FIXME: This prevents ->CursorMaxPos based bounding box evaluation from working (e.g. TableEndCell)

        -- Between 1.71 and 1.92.7, we maintained a hack where a 1.0f thin Separator() would not impact layout.
        -- This was mostly chosen to allow backward compatibility with user's code assuming zero-height when calculating height for layout (e.g. bottom alignment of a status bar).
        -- In order to handle scaling we need to scale separator thickness and it would not makes sense to have a disparity depending on height.
        ----float thickness_for_layout = (thickness == 1.0f) ? 0.0f : thickness; // FIXME: See 1.70/1.71 Separator() change: makes legacy 1-px separator not affect layout yet. Should change.
        local bb = ImRect(x1, window.DC.CursorPos.y, x2, window.DC.CursorPos.y + thickness) -- [Luau] no temporary ImVec2
        local item_size = LayoutHelpers_size; item_size.x = 0.0; item_size.y = thickness
        ImGui.ItemSize(item_size)

        if ImGui.ItemAdd(bb, 0) then
            -- Draw
            window.DrawList:AddRectFilled(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.Separator))
            if g.LogEnabled then
                ImGui.LogRenderedText(bb.Min, "--------------------------------")
            end
        end

        if columns then
            ImGui.PopColumnsBackground()
            columns.LineMinY = window.DC.CursorPos.y
        end
    end
end

function ImGui.Separator()
    local g = GImGui
    local window = g.CurrentWindow
    if window.SkipItems then
        return
    end

    -- Those flags should eventually be configurable by the user
    local flags
    if window.DC.LayoutType == ImGuiLayoutType.Horizontal then
        flags = ImGuiSeparatorFlags.Vertical
    else
        flags = ImGuiSeparatorFlags.Horizontal
    end

    -- Only applies to legacy Columns() api as they relied on Separator() a lot.
    if window.DC.CurrentColumns then
        flags = bit32.bor(flags, ImGuiSeparatorFlags.SpanAllColumns)
    end

    ImGui.SeparatorEx(flags, ImMax(g.Style.SeparatorSize, 1.0))
end

--- @param id         ImGuiID
--- @param label      string
--- @param label_end? int
--- @param extra_w    float
function ImGui.SeparatorTextEx(id, label, label_end, extra_w)
    local g = GImGui
    local window = g.CurrentWindow
    local style = g.Style

    local label_size = ImGui.CalcTextSize(label, label_end, false)
    local pos = ImVec2(window.DC.CursorPos.x, window.DC.CursorPos.y)
    local padding = style.SeparatorTextPadding

    local separator_thickness = style.SeparatorTextBorderSize
    local min_size = ImVec2(label_size.x + extra_w + padding.x * 2.0, ImMax(label_size.y + padding.y * 2.0, separator_thickness))

    local bb = ImRect(pos, ImVec2(window.WorkRect.Max.x, pos.y + min_size.y))
    local text_baseline_y = ImTrunc((bb:GetHeight() - label_size.y) * style.SeparatorTextAlign.y + 0.999) --ImMax(padding.y, ImTrunc((style.SeparatorTextSize - label_size.y) * 0.5f))

    ImGui.ItemSize(min_size, text_baseline_y)
    if not ImGui.ItemAdd(bb, id) then
        return
    end

    local sep1_x1 = pos.x
    local sep2_x2 = bb.Max.x
    local seps_y = ImTrunc((bb.Min.y + bb.Max.y) * 0.5 + 0.999)

    local label_avail_w = ImMax(0.0, sep2_x2 - sep1_x1 - padding.x * 2.0)
    local label_pos = ImVec2(pos.x + padding.x + ImMax(0.0, (label_avail_w - label_size.x - extra_w) * style.SeparatorTextAlign.x), pos.y + text_baseline_y) -- FIXME-ALIGN

    -- This allows using SameLine() to position something in the 'extra_w'
    window.DC.CursorPosPrevLine.x = label_pos.x + label_size.x

    local separator_col = ImGui.GetColorU32(ImGuiCol.Separator)

    if label_size.x > 0.0 then
        local sep1_x2 = label_pos.x - style.ItemSpacing.x
        local sep2_x1 = label_pos.x + label_size.x + extra_w + style.ItemSpacing.x

        if sep1_x2 > sep1_x1 and separator_thickness > 0.0 then
            window.DrawList:AddLineH(sep1_x1, sep1_x2, seps_y, separator_col, separator_thickness)
        end

        if sep2_x2 > sep2_x1 and separator_thickness > 0.0 then
            window.DrawList:AddLineH(sep2_x1, sep2_x2, seps_y, separator_col, separator_thickness)
        end

        if g.LogEnabled then
            ImGui.LogSetNextTextDecoration("---", nil)
        end

        ImGui.RenderTextEllipsis(window.DrawList, label_pos, ImVec2(bb.Max.x, bb.Max.y + style.ItemSpacing.y), bb.Max.x, label, label_end, label_size)
    else
        if g.LogEnabled then
            ImGui.LogText("---")
        end

        if separator_thickness > 0.0 then
            window.DrawList:AddLineH(sep1_x1, sep2_x2, seps_y, separator_col, separator_thickness)
        end
    end
end

--- @param label string
function ImGui.SeparatorText(label)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return
    end

    -- The SeparatorText() vs SeparatorTextEx() distinction is designed to be considerate that we may want:
    -- - allow separator-text to be draggable items (would require a stable ID + a noticeable highlight)
    -- - this high-level entry point to allow formatting? (which in turns may require ID separate from formatted string)
    -- - because of this we probably can't turn 'string label' into 'string fmt, ...'
    -- Otherwise, we can decide that users wanting to drag this would layout a dedicated drag-item,
    -- and then we can turn this into a format function.
    ImGui.SeparatorTextEx(0, label, ImGui.FindRenderedTextEnd(label), 0.0)
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: ComboBox
-------------------------------------------------------------------------------
-- - CalcMaxPopupHeightFromItemCount() [Internal]
-- - BeginCombo()
-- - BeginComboPopup() [Internal]
-- - EndCombo()
-- - BeginComboPreview() [Internal]
-- - EndComboPreview() [Internal]
-- - Combo()
-------------------------------------------------------------------------------

--- @param items_count float
--- @return float
local function CalcMaxPopupHeightFromItemCount(items_count)
    local g = GImGui
    if items_count <= 0 then
        return FLT_MAX
    end
    return (g.FontSize + g.Style.ItemSpacing.y) * items_count - g.Style.ItemSpacing.y + (g.Style.WindowPadding.y * 2)
end

--- @param label          string
--- @param preview_value? string
--- @param flags?         ImGuiComboFlags
function ImGui.BeginCombo(label, preview_value, flags)
    if flags == nil then flags = 0 end

    local g = GImGui
    local window = ImGui.GetCurrentWindow()

    local backup_next_window_data_flags = g.NextWindowData.HasFlags
    g.NextWindowData:ClearFlags() -- We behave like Begin() and need to consume those values
    if window.SkipItems then
        return false
    end

    local style = g.Style
    local id = window:GetID(label)
    IM_ASSERT(bit32.band(flags, bit32.bor(ImGuiComboFlags.NoArrowButton, ImGuiComboFlags.NoPreview)) ~= bit32.bor(ImGuiComboFlags.NoArrowButton, ImGuiComboFlags.NoPreview)) -- Can't use both flags together
    if bit32.band(flags, ImGuiComboFlags.WidthFitPreview) ~= 0 then
        IM_ASSERT(bit32.band(flags, bit32.bor(ImGuiComboFlags.NoPreview, ImGuiComboFlags.CustomPreview)) == 0)
    end

    local arrow_size
    if (bit32.band(flags, ImGuiComboFlags.NoArrowButton) ~= 0) then
        arrow_size = 0.0
    else
        arrow_size = ImGui.GetFrameHeight()
    end

    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)

    local preview_width
    if ((bit32.band(flags, ImGuiComboFlags.WidthFitPreview) ~= 0) and (preview_value ~= nil)) then
        preview_width = ImGui.CalcTextSize(preview_value, nil, false).x
    else
        preview_width = 0.0
    end

    local w
    if bit32.band(flags, ImGuiComboFlags.NoPreview) ~= 0 then
        w = arrow_size
    elseif bit32.band(flags, ImGuiComboFlags.WidthFitPreview) ~= 0 then
        w = arrow_size + preview_width + style.FramePadding.x * 2.0
    else
        w = ImGui.CalcItemWidth()
    end

    local bb = ImRect(window.DC.CursorPos, window.DC.CursorPos + ImVec2(w, label_size.y + style.FramePadding.y * 2.0))
    local label_offset = (label_size.x > 0.0) and (style.ItemInnerSpacing.x + label_size.x) or 0.0
    local total_bb = ImRect(bb.Min, bb.Max + ImVec2(label_offset, 0.0))

    ImGui.ItemSize(total_bb, style.FramePadding.y)
    if not ImGui.ItemAdd(total_bb, id, bb) then
        return false
    end

    -- Open on click
    local pressed, hovered, held = ImGui.ButtonBehavior(bb, id)
    local popup_id = ImHashStr("##ComboPopup", nil, id)
    local popup_open = ImGui.IsPopupOpen(popup_id, ImGuiPopupFlags.None)
    if pressed and not popup_open then
        ImGui.OpenPopupEx(popup_id, ImGuiPopupFlags.None)
        popup_open = true
    end

    -- Render shape
    local frame_col = ImGui.GetColorU32(hovered and ImGuiCol.FrameBgHovered or ImGuiCol.FrameBg)
    local value_x2 = ImMax(bb.Min.x, bb.Max.x - arrow_size)

    ImGui.RenderNavCursor(bb, id)

    if bit32.band(flags, ImGuiComboFlags.NoPreview) == 0 then
        window.DrawList:AddRectFilled(bb.Min, ImVec2(value_x2, bb.Max.y), frame_col, style.FrameRounding, (bit32.band(flags, ImGuiComboFlags.NoArrowButton) ~= 0) and ImDrawFlags.RoundCornersAll or ImDrawFlags.RoundCornersLeft)
    end

    if bit32.band(flags, ImGuiComboFlags.NoArrowButton) == 0 then
        local bg_col = ImGui.GetColorU32((popup_open or hovered) and ImGuiCol.ButtonHovered or ImGuiCol.Button)
        local text_col = ImGui.GetColorU32(ImGuiCol.Text)

        window.DrawList:AddRectFilled(ImVec2(value_x2, bb.Min.y), bb.Max, bg_col, style.FrameRounding, (w <= arrow_size) and ImDrawFlags.RoundCornersAll or ImDrawFlags.RoundCornersRight)

        if value_x2 + arrow_size - style.FramePadding.x <= bb.Max.x then
            ImGui.RenderArrow(window.DrawList, ImVec2(value_x2 + style.FramePadding.y, bb.Min.y + style.FramePadding.y), text_col, ImGuiDir.Down, 1.0)
        end
    end

    ImGui.RenderFrameBorder(bb.Min, bb.Max, style.FrameRounding)

    -- Custom preview
    if bit32.band(flags, ImGuiComboFlags.CustomPreview) ~= 0 then
        g.ComboPreviewData.PreviewRect = ImRect(bb.Min.x, bb.Min.y, value_x2, bb.Max.y)
        IM_ASSERT(preview_value == nil or preview_value == "")
        preview_value = nil
    end

    -- Render preview and label
    if preview_value ~= nil and bit32.band(flags, ImGuiComboFlags.NoPreview) == 0 then
        if g.LogEnabled then
            ImGui.LogSetNextTextDecoration("{", "}")
        end
        ImGui.RenderTextClipped(bb.Min + style.FramePadding, ImVec2(value_x2, bb.Max.y), preview_value, nil, nil)
    end

    if label_size.x > 0 then
        ImGui.RenderText(ImVec2(bb.Max.x + style.ItemInnerSpacing.x, bb.Min.y + style.FramePadding.y), label, 1, label_end, false)
    end

    if not popup_open then
        return false
    end

    g.NextWindowData.HasFlags = backup_next_window_data_flags
    return ImGui.BeginComboPopup(popup_id, bb, flags)
end

--- @param popup_id ImGuiID
--- @param bb       ImRect
--- @param flags    ImGuiComboFlags
function ImGui.BeginComboPopup(popup_id, bb, flags)
    local g = GImGui
    if not ImGui.IsPopupOpen(popup_id, ImGuiPopupFlags.None) then
        g.NextWindowData:ClearFlags()
        return false
    end

    -- Set popup size
    local w = bb:GetWidth()
    if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasSizeConstraint) ~= 0 then
        g.NextWindowData.SizeConstraintRect.Min.x = ImMax(g.NextWindowData.SizeConstraintRect.Min.x, w)
    else
        if bit32.band(flags, ImGuiComboFlags.HeightMask_) == 0 then
            flags = bit32.bor(flags, ImGuiComboFlags.HeightRegular)
        end
        IM_ASSERT(ImIsPowerOfTwo(bit32.band(flags, ImGuiComboFlags.HeightMask_))) -- Only one
        local popup_max_height_in_items = -1
        if bit32.band(flags, ImGuiComboFlags.HeightRegular) ~= 0 then
            popup_max_height_in_items = 8
        elseif bit32.band(flags, ImGuiComboFlags.HeightSmall) ~= 0 then
            popup_max_height_in_items = 4
        elseif bit32.band(flags, ImGuiComboFlags.HeightLarge) ~= 0 then
            popup_max_height_in_items = 20
        end
        local constraint_min = ImVec2(0.0, 0.0)
        local constraint_max = ImVec2(FLT_MAX, FLT_MAX)
        if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasSize) == 0 or g.NextWindowData.SizeVal.x <= 0.0 then -- Don't apply constraints if user specified a size
            constraint_min.x = w
        end
        if bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasSize) == 0 or g.NextWindowData.SizeVal.y <= 0.0 then
            constraint_max.y = CalcMaxPopupHeightFromItemCount(popup_max_height_in_items)
        end
        ImGui.SetNextWindowSizeConstraints(constraint_min, constraint_max)
    end

    -- This is essentially a specialized version of BeginPopupEx()
    local name = ImFormatString("##Combo_%02d", g.BeginComboDepth) -- Recycle windows based on depth

    -- Set position given a custom constraint (peak into expected window size so we can position it)
    -- FIXME: This might be easier to express with an hypothetical SetNextWindowPosConstraints() function?
    -- FIXME: This might be moved to Begin() or at least around the same spot where Tooltips and other Popups are calling FindBestWindowPosForPopupEx()?
    local popup_window = ImGui.FindWindowByName(name)
    if popup_window then
        if popup_window.WasActive then
            -- Always override 'AutoPosLastDirection' to not leave a chance for a past value to affect us.
            local size_expected = ImGui.CalcWindowNextAutoFitSize(popup_window)
            popup_window.AutoPosLastDirection = (bit32.band(flags, ImGuiComboFlags.PopupAlignLeft) ~= 0) and ImGuiDir.Left or ImGuiDir.Down -- Left = "Below, Toward Left", Down = "Below, Toward Right (default)"
            local r_outer = ImGui.GetPopupAllowedExtentRect(popup_window)
            local pos
            pos, popup_window.AutoPosLastDirection = ImGui.FindBestWindowPosForPopupEx(bb:GetBL(), size_expected, popup_window.AutoPosLastDirection, r_outer, bb, ImGuiPopupPositionPolicy.ComboBox)
            ImGui.SetNextWindowPos(pos)
        end
    end

    -- We don't use BeginPopupEx() solely because we have a custom name string, which we could make an argument to BeginPopupEx()
    local window_flags = bit32.bor(ImGuiWindowFlags.AlwaysAutoResize, ImGuiWindowFlags.Popup, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoResize, ImGuiWindowFlags.NoSavedSettings, ImGuiWindowFlags.NoMove)
    ImGui.PushStyleVarX(ImGuiStyleVar.WindowPadding, g.Style.FramePadding.x) -- Horizontally align ourselves with the framed text
    local _, ret = ImGui.Begin(name, nil, window_flags)
    ImGui.PopStyleVar()
    if not ret then
        ImGui.EndPopup()
        if not g.IO.ConfigDebugBeginReturnValueOnce and not g.IO.ConfigDebugBeginReturnValueLoop then
            -- Begin may only return false with those debug tools activated.
            IM_ASSERT(false) -- This should never happen as we tested for IsPopupOpen() above
        end
        return false
    end

    g.BeginComboDepth = g.BeginComboDepth + 1

    return true
end

function ImGui.EndCombo()
    local g = GImGui
    g.BeginComboDepth = g.BeginComboDepth - 1

    local name = ImFormatString("##Combo_%02d", g.BeginComboDepth) -- FIXME: Move those to helpers?

    if g.CurrentWindow.Name ~= name then
        IM_ASSERT_USER_ERROR_RET(false, "Calling EndCombo() in wrong window!")
    end

    ImGui.EndPopup()
end

-- Submit preview contents for BeginCombo()/EndCombo(), to display contents that's more than just a text label.
-- - [BETA] See GitHub issues: #1658, #4168.
-- - Call directly after the BeginCombo/EndCombo block (requires ImGuiComboFlags.CustomPreview).
-- - The preview is designed to only host non-interactive elements.
-- - Not compatible with ImGuiComboFlags.WidthFitPreview.
function ImGui.BeginComboPreview()
    local g = GImGui
    local window = g.CurrentWindow
    local preview_data = g.ComboPreviewData

    if window.SkipItems or not (bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.Visible) ~= 0) then
        return false
    end

    IM_ASSERT(g.LastItemData.Rect.Min.x == preview_data.PreviewRect.Min.x and g.LastItemData.Rect.Min.y == preview_data.PreviewRect.Min.y) -- Didn't call after BeginCombo/EndCombo block or forgot to pass ImGuiComboFlags.CustomPreview flag?

    if not window.ClipRect:Overlaps(preview_data.PreviewRect) then -- Narrower test (optional)
        return false
    end

    -- FIXME: This could be contained in a PushWorkRect() api
    ImVec2_Copy(preview_data.BackupCursorPos, window.DC.CursorPos)
    ImVec2_Copy(preview_data.BackupCursorMaxPos, window.DC.CursorMaxPos)
    ImVec2_Copy(preview_data.BackupCursorPosPrevLine, window.DC.CursorPosPrevLine)
    preview_data.BackupPrevLineTextBaseOffset = window.DC.PrevLineTextBaseOffset
    preview_data.BackupLayout = window.DC.LayoutType

    ImVec2_Copy(window.DC.CursorPos, preview_data.PreviewRect.Min + g.Style.FramePadding)
    ImVec2_Copy(window.DC.CursorMaxPos, window.DC.CursorPos)
    window.DC.LayoutType = ImGuiLayoutType.Horizontal
    window.DC.IsSameLine = false

    ImGui.PushClipRect(preview_data.PreviewRect.Min, preview_data.PreviewRect.Max, true)

    return true
end

function ImGui.EndComboPreview()
    local g = GImGui
    local window = g.CurrentWindow
    local preview_data = g.ComboPreviewData

    -- FIXME: Using CursorMaxPos approximation instead of correct AABB which we will store in ImDrawCmd in the future
    local draw_list = window.DrawList
    if window.DC.CursorMaxPos.x < preview_data.PreviewRect.Max.x and window.DC.CursorMaxPos.y < preview_data.PreviewRect.Max.y then
        if draw_list.CmdBuffer.Size > 1 then -- Unlikely case that the PushClipRect() didn't create a command
            ImVec4_Copy(draw_list.CmdBuffer.Data[draw_list.CmdBuffer.Size].ClipRect, draw_list.CmdBuffer.Data[draw_list.CmdBuffer.Size - 1].ClipRect)
            ImVec4_Copy(draw_list._CmdHeader.ClipRect, draw_list.CmdBuffer.Data[draw_list.CmdBuffer.Size].ClipRect)
            draw_list:_TryMergeDrawCmds()
        end
    end

    ImGui.PopClipRect()

    ImVec2_Copy(window.DC.CursorPos, preview_data.BackupCursorPos)
    ImVec2_Copy(window.DC.CursorMaxPos, ImMax(window.DC.CursorMaxPos, preview_data.BackupCursorMaxPos)) -- No need to do the same with IdealMaxPos
    ImVec2_Copy(window.DC.CursorPosPrevLine, preview_data.BackupCursorPosPrevLine)
    window.DC.PrevLineTextBaseOffset = preview_data.BackupPrevLineTextBaseOffset
    window.DC.LayoutType = preview_data.BackupLayout
    window.DC.IsSameLine = false

    preview_data.PreviewRect = ImRect()
end

-- Getter for the old Combo() API: Lua array of strings (1-based), `idx` is 0-based
local function Items_ArrayGetter(data, idx)
    return data[idx + 1]
end

-- Getter for the old Combo() API: "item1\0item2\0item3\0"
local function Items_SingleStringGetter(data, idx)
    local items_count = 0
    local p = 1
    while p <= #data and string.byte(data, p) ~= 0 do
        local e = string.find(data, "\0", p, true) or (#data + 1)
        if idx == items_count then
            return string.sub(data, p, e - 1)
        end
        p = e + 1
        items_count = items_count + 1
    end
    return nil
end

local function Items_SingleStringCount(data)
    local items_count = 0
    local p = 1
    while p <= #data and string.byte(data, p) ~= 0 do
        p = (string.find(data, "\0", p, true) or #data) + 1
        items_count = items_count + 1
    end
    return items_count
end

-- Normalizes the 3 upstream overloads to (getter, user_data, items_count, height)
-- - (items: string[], items_count?, height?)
-- - (items_separated_by_zeros: string, height?)
-- - (getter: fun(user_data, idx): string?, user_data, items_count, height?)
local function Items_ResolveArgs(a, b, c, d)
    if type(a) == "function" then
        return a, b, c, d
    elseif type(a) == "string" then
        return Items_SingleStringGetter, a, Items_SingleStringCount(a), b
    else
        return Items_ArrayGetter, a, b or #a, c
    end
end

-- Old API, prefer using BeginCombo() nowadays if you can.
--- @param label        string
--- @param current_item int     # 0-based
--- @return int  current_item
--- @return bool value_changed
function ImGui.Combo(label, current_item, a, b, c, d)
    local g = GImGui
    local getter, user_data, items_count, popup_max_height_in_items = Items_ResolveArgs(a, b, c, d)
    if popup_max_height_in_items == nil then popup_max_height_in_items = -1 end

    -- Call the getter to obtain the preview string which is a parameter to BeginCombo()
    local preview_value = nil
    if bit32.band(bit32.bor(g.NextItemData.ItemFlagsSet, g.CurrentItemFlags), ImGuiItemFlags.MixedValue) ~= 0 then
        preview_value = ""
    elseif current_item >= 0 and current_item < items_count then
        preview_value = getter(user_data, current_item)
    end

    -- The old Combo() API exposed "popup_max_height_in_items". The new more general BeginCombo() API doesn't have/need it, but we emulate it here.
    if popup_max_height_in_items ~= -1 and bit32.band(g.NextWindowData.HasFlags, ImGuiNextWindowDataFlags.HasSizeConstraint) == 0 then
        ImGui.SetNextWindowSizeConstraints(ImVec2(0, 0), ImVec2(FLT_MAX, CalcMaxPopupHeightFromItemCount(popup_max_height_in_items)))
    end

    if not ImGui.BeginCombo(label, preview_value, ImGuiComboFlags.None) then
        return current_item, false
    end

    -- Display items
    local value_changed = false
    local clipper = ImGuiListClipper()
    clipper:Begin(items_count)
    clipper:IncludeItemByIndex(current_item)
    while clipper:Step() do
        for i = clipper.DisplayStart, clipper.DisplayEnd - 1 do
            local item_text = getter(user_data, i)
            if item_text == nil then
                item_text = "*Unknown item*"
            end

            ImGui.PushID(i)
            local item_selected = (i == current_item)
            if ImGui.Selectable(item_text, item_selected) and current_item ~= i then
                value_changed = true
                current_item = i
            end
            if item_selected then
                ImGui.SetItemDefaultFocus()
            end
            ImGui.PopID()
        end
    end

    ImGui.EndCombo()
    if value_changed then
        ImGui.MarkItemEdited(g.LastItemData.ID)
    end

    return current_item, value_changed
end

-------------------------------------------------------------------------------
-- [SECTION] Data Type and Data Formatting Helpers [Internal]
-------------------------------------------------------------------------------
-- - DataTypeGetInfo()
-- - DataTypeFormatString()
-- - DataTypeApplyOp()
-- - DataTypeApplyFromText()
-- - DataTypeCompare()
-- - DataTypeClamp()
-- - GetMinimumStepAtDecimalPrecision
-- - RoundScalarWithFormat<>()
-------------------------------------------------------------------------------

local function float(val) return val end
local function double(val) return val end

local GDefaultRgbaColorMarkers = {
    IM_COL32(240, 20, 20, 255), IM_COL32(20, 240, 20, 255), IM_COL32(20, 20, 240, 255), IM_COL32(140, 140, 140, 255)
}

--- @param size      size_t
--- @param name      string
--- @param print_fmt string
--- @param scan_fmt  string
--- @return ImGuiDataTypeInfo
--- @nodiscard
--- @package
local function ImGuiDataTypeInfo(size, name, print_fmt, scan_fmt)
    return { Size = size, Name = name, PrintFmt = print_fmt, ScanFmt = scan_fmt }
end

local GDataTypeInfo = {
    ImGuiDataTypeInfo(1, "S8",     "%d",   "%d"), -- ImGuiDataType.S8
    ImGuiDataTypeInfo(1, "U8",     "%u",   "%u"),
    ImGuiDataTypeInfo(2, "S16",    "%d",   "%d"), -- ImGuiDataType.S16
    ImGuiDataTypeInfo(2, "U16",    "%u",   "%u"),
    ImGuiDataTypeInfo(4, "S32",    "%d",   "%d"), -- ImGuiDataType.S32
    ImGuiDataTypeInfo(4, "U32",    "%u",   "%u"),
    ImGuiDataTypeInfo(4, "float",  "%.3f", "%f"), -- ImGuiDataType.Float
    ImGuiDataTypeInfo(8, "double", "%f",   "%lf"), -- ImGuiDataType.Double
    ImGuiDataTypeInfo(1, "bool",   "%d",   "%d"), -- ImGuiDataType.Bool
    ImGuiDataTypeInfo(0, "string", "%s",   "%s") -- ImGuiDataType.String
}

--- @param data_type ImGuiDataType
function ImGui.DataTypeGetInfo(data_type)
    IM_ASSERT(data_type >= 0 and data_type < ImGuiDataType.COUNT)
    return GDataTypeInfo[data_type + 1]
end

--- @param buf       char[]
--- @param buf_size  int
--- @param data_type ImGuiDataType
--- @param data      number
--- @param format    string
function ImGui.DataTypeFormatString(buf, buf_size, data_type, data, format)
    local str
    if     data_type == ImGuiDataType.S32 then
        str = ImFormatString(format, (ImS32)(data))
    elseif data_type == ImGuiDataType.U32 then
        str = ImFormatString(format, (ImU32)(data))
    elseif data_type == ImGuiDataType.Float then
        str = ImFormatString(format, data)
    elseif data_type == ImGuiDataType.Double then
        str = ImFormatString(format, data)
    elseif data_type == ImGuiDataType.S8 then
        str = ImFormatString(format, (ImS8)(data))
    elseif data_type == ImGuiDataType.U8 then
        str = ImFormatString(format, (ImU8)(data))
    elseif data_type == ImGuiDataType.S16 then
        str = ImFormatString(format, (ImS16)(data))
    elseif data_type == ImGuiDataType.U16 then
        str = ImFormatString(format, (ImU16)(data))
    else
        IM_ASSERT(false)
    end
    ImStd.ImStrncpy(buf, 1, { string.byte(str, 1, #str) }, 1, ImMin(#str + 1, buf_size)) -- TODO: update this when new ImFormatString is implemented
end

--- @param data_type ImGuiDataType
--- @param op        int
--- @param arg1      number
--- @param arg2      number
function ImGui.DataTypeApplyOp(data_type, op, arg1, arg2)
    IM_ASSERT(op == 43 or op == 45) -- '+' or '-'

    if data_type == ImGuiDataType.S8 then
        if op == 43 then
            return ImAddClampOverflow(arg1, arg2, IM_S8_MIN, IM_S8_MAX)
        elseif op == 45 then
            return ImSubClampOverflow(arg1, arg2, IM_S8_MIN, IM_S8_MAX)
        end
    elseif data_type == ImGuiDataType.U8 then
        if op == 43 then
            return ImAddClampOverflow(arg1, arg2, IM_U8_MIN, IM_U8_MAX)
        elseif op == 45 then
            return ImSubClampOverflow(arg1, arg2, IM_U8_MIN, IM_U8_MAX)
        end
    elseif data_type == ImGuiDataType.S16 then
        if op == 43 then
            return ImAddClampOverflow((ImS16)(arg1), (ImS16)(arg2), IM_S16_MIN, IM_S16_MAX)
        elseif op == 45 then
            return ImSubClampOverflow((ImS16)(arg1), (ImS16)(arg2), IM_S16_MIN, IM_S16_MAX)
        end
    elseif data_type == ImGuiDataType.U16 then
        if op == 43 then
            return ImAddClampOverflow((ImU16)(arg1), (ImU16)(arg2), IM_U16_MIN, IM_U16_MAX)
        elseif op == 45 then
            return ImSubClampOverflow((ImU16)(arg1), (ImU16)(arg2), IM_U16_MIN, IM_U16_MAX)
        end
    elseif data_type == ImGuiDataType.S32 then
        if op == 43 then
            return ImAddClampOverflow(arg1, arg2, IM_S32_MIN, IM_S32_MAX)
        elseif op == 45 then
            return ImSubClampOverflow(arg1, arg2, IM_S32_MIN, IM_S32_MAX)
        end
    elseif data_type == ImGuiDataType.U32 then
        if op == 43 then
            return ImAddClampOverflow(arg1, arg2, IM_U32_MIN, IM_U32_MAX)
        elseif op == 45 then
            return ImSubClampOverflow(arg1, arg2, IM_U32_MIN, IM_U32_MAX)
        end
    elseif data_type == ImGuiDataType.Float then
        if op == 43 then
            return arg1 + arg2
        elseif op == 45 then
            return arg1 - arg2
        end
    elseif data_type == ImGuiDataType.Double then
        if op == 43 then
            return arg1 + arg2
        elseif op == 45 then
            return arg1 - arg2
        end
    end

    IM_ASSERT(false)
end

local ImParseFormatSanitizeForScanning

-- User can input math operators (e.g. +100) to edit a numerical values.
-- NB: This is _not_ a full expression evaluator. We should probably add one and replace this dumb mess..
--- @param buf              char[]
--- @param data_type        ImGuiDataType
--- @param data             number
--- @param format           string
--- @param data_when_empty? number
function ImGui.DataTypeApplyFromText(buf, data_type, data, format, data_when_empty)
    -- Copy the value so we can compare at the end of the function if it changed at all.
    local type_info = ImGui.DataTypeGetInfo(data_type)
    local data_backup = data

    local p = 1
    while ImCharIsBlankA(buf[p]) do
        p = p + 1
    end
    if buf[p] == 0 then
        if data_when_empty ~= nil then
            data = data_when_empty
            return data, data_backup ~= data
        end
        return data, false
    end

    -- Sanitize format
    -- - For float/double we have to ignore format with precision (e.g. "%.2f") because sscanf doesn't take them in, so force them into %f and %lf
    local format_sanitized, format_sanitized_size = {}, 32
    if (data_type == ImGuiDataType.Float or data_type == ImGuiDataType.Double) then
        format = type_info.ScanFmt
    else
        format = ImParseFormatSanitizeForScanning(format, format_sanitized, format_sanitized_size)
        if format[1] == 0 then
            format = type_info.ScanFmt -- Format doesn't want us to show the number currently, but we still need to parse the resulting input
        end
    end

    -- Small types need a 32-bit buffer to receive the result from scanf()
    local v32 = 0
    local res = {}
    if ImStd.sscanf(buf, 1, format, res) < 1 then
        return data, false
    end
    if type_info.Size >= 4 then
        data = res[1]
    else
        v32 = res[1]
    end

    if type_info.Size < 4 then
        if data_type == ImGuiDataType.S8 then
            data = (ImS8)(ImClamp(v32, IM_S8_MIN, IM_S8_MAX))
        elseif data_type == ImGuiDataType.U8 then
            data = (ImU8)(ImClamp(v32, IM_U8_MIN, IM_U8_MAX))
        elseif data_type == ImGuiDataType.S16 then
            data = (ImS16)(ImClamp(v32, IM_S16_MIN, IM_S16_MAX))
        elseif data_type == ImGuiDataType.U16 then
            data = (ImU16)(ImClamp(v32, IM_U16_MIN, IM_U16_MAX))
        else
            IM_ASSERT(false)
        end
    end

    return data, data_backup ~= data
end

--- @generic T : number
--- @param lhs T
--- @param rhs T
local function DataTypeCompareT(lhs, rhs)
    if lhs < rhs then return -1 end
    if lhs > rhs then return  1 end
    return 0
end

--- @param data_type ImGuiDataType
--- @param arg1      number
--- @param arg2      number
function ImGui.DataTypeCompare(data_type, arg1, arg2)
    if     data_type == ImGuiDataType.S8  then return DataTypeCompareT((ImS8)(arg1), (ImS8)(arg2))
    elseif data_type == ImGuiDataType.U8  then return DataTypeCompareT((ImU8)(arg1), (ImU8)(arg2))
    elseif data_type == ImGuiDataType.S16 then return DataTypeCompareT((ImS16)(arg1), (ImS16)(arg2))
    elseif data_type == ImGuiDataType.U16 then return DataTypeCompareT((ImU16)(arg1), (ImU16)(arg2))
    elseif data_type == ImGuiDataType.S32 then return DataTypeCompareT((ImS32)(arg1), (ImS32)(arg2))
    elseif data_type == ImGuiDataType.U32 then return DataTypeCompareT((ImU32)(arg1), (ImU32)(arg2))
    elseif data_type == ImGuiDataType.Float  then return DataTypeCompareT(arg1, arg2)
    elseif data_type == ImGuiDataType.Double then return DataTypeCompareT(arg1, arg2)
    end
    IM_ASSERT(false)
    return 0
end

--- @generic T : number
--- @param v      T
--- @param v_min? T
--- @param v_max? T
--- @return T, boolean
local function DataTypeClampT(v, v_min, v_max)
    -- Clamp, both sides are optional, return true if modified
    if v_min and v < v_min then return v_min, true end
    if v_max and v > v_max then return v_max, true end
    return v, false
end

--- @param data_type ImGuiDataType
--- @param data      number
--- @param min?      number
--- @param max?      number
function ImGui.DataTypeClamp(data_type, data, min, max)
    if     data_type == ImGuiDataType.S8  then return DataTypeClampT((ImS8)(data),  min and (ImS8)(min),  max and (ImS8)(max))
    elseif data_type == ImGuiDataType.U8  then return DataTypeClampT((ImU8)(data),  min and (ImU8)(min),  max and (ImU8)(max))
    elseif data_type == ImGuiDataType.S16 then return DataTypeClampT((ImS16)(data), min and (ImS16)(min), max and (ImS16)(max))
    elseif data_type == ImGuiDataType.U16 then return DataTypeClampT((ImU16)(data), min and (ImU16)(min), max and (ImU16)(max))
    elseif data_type == ImGuiDataType.S32 then return DataTypeClampT((ImS32)(data), min and (ImS32)(min), max and (ImS32)(max))
    elseif data_type == ImGuiDataType.U32 then return DataTypeClampT((ImU32)(data), min and (ImU32)(min), max and (ImU32)(max))
    elseif data_type == ImGuiDataType.Float  then return DataTypeClampT(data, min, max)
    elseif data_type == ImGuiDataType.Double then return DataTypeClampT(data, min, max)
    end
    IM_ASSERT(false)
    return data, false
end

--- @param data_type ImGuiDataType
--- @param data      number
function ImGui.DataTypeIsZero(data_type, data)
    local g = GImGui
    return ImGui.DataTypeCompare(data_type, data, g.DataTypeZeroValue) == 0
end

local GetMinimumStepAtDecimalPrecision do

local min_steps = { 1.0, 0.1, 0.01, 0.001, 0.0001, 0.00001, 0.000001, 0.0000001, 0.00000001, 0.000000001 }

--- @param decimal_precision int
--- @return float
function GetMinimumStepAtDecimalPrecision(decimal_precision)
    if decimal_precision < 0 then
        return FLT_MIN
    end
    if decimal_precision < #min_steps then
        return min_steps[decimal_precision + 1]
    else
        return ImPow(10.0, -decimal_precision)
    end
end

end

local ImParseFormatFindStart

--- @param format    string
--- @param data_type ImGuiDataType
--- @param v         number
function ImGui.RoundScalarWithFormatT(format, data_type, v)
    -- IM_UNUSED(data_type)
    IM_ASSERT(data_type == ImGuiDataType.Float or data_type == ImGuiDataType.Double)
    local fmt_start = ImParseFormatFindStart(format)
    if string.byte(format, fmt_start) ~= 37 or string.byte(format, fmt_start + 1) == 37 then
        return v -- Don't apply if the value is not visible in the format string
    end

    -- TODO: Sanitize format

    -- Format value with our rounding, and read back
    local str = ImFormatString(format, v)

    v = ImAtof(str) or v
    return v
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: InputScalar, InputFloat, InputInt, etc.
-------------------------------------------------------------------------------
-- - ImParseFormatFindStart() [Internal]
-- - ImParseFormatFindEnd() [Internal]
-- - ImParseFormatTrimDecorations() [Internal]
-- - ImParseFormatSanitizeForScanning() [Internal]
-- - ImParseFormatPrecision() [Internal]
-- - TempInputText() [Internal]
-- - TempInputScalar() [Internal]
-- - InputScalar()
-- - InputScalarN()
-- - InputFloat()
-- - InputFloat2()
-- - InputFloat3()
-- - InputFloat4()
-- - InputInt()
-- - InputInt2()
-- - InputInt3()
-- - InputInt4()
-- - InputDouble()
-------------------------------------------------------------------------------

-- We don't use strchr() because our strings are usually very short and often start with '%'
--- @param fmt string
function ImParseFormatFindStart(fmt)
    local len = #fmt
    local i = 1
    local c
    while i < len do
        c = string.byte(fmt, i)
        if c == 37 and string.byte(fmt, i + 1) ~= 37 then -- '%'
            return i
        elseif c == 37 then
            i = i + 1
        end
        i = i + 1
    end
    return nil
end

--- @param fmt string
--- @param pos int
local function ImParseFormatFindEnd(fmt, pos)
    -- Printf/scanf types modifiers: I/L/h/j/l/t/w/z. Other uppercase letters qualify as types aka end of the format.
    if string.byte(fmt, pos) ~= 37 then -- '%'
        return pos
    end
    local ignored_uppercase_mask = bit32.bor(bit32.lshift(1, 73 - 65), bit32.lshift(1, 76 - 65))
    local ignored_lowercase_mask = bit32.bor(bit32.lshift(1, 104 - 97), bit32.lshift(1, 106 - 97), bit32.lshift(1, 108 - 97), bit32.lshift(1, 116 - 97), bit32.lshift(1, 119 - 97), bit32.lshift(1, 122 - 97))
    local len = #fmt
    local c
    for i = pos, len do
        c = string.byte(fmt, i)
        if c >= 65 and c <= 90 and (bit32.band(bit32.lshift(1, c - 65), ignored_uppercase_mask) == 0) then
            return i + 1
        end
        if c >= 97 and c <= 122 and (bit32.band(bit32.lshift(1, c - 97), ignored_lowercase_mask) == 0) then
            return i + 1
        end
    end
    return len + 1
end

-- Extract the format out of a format string with leading or trailing decorations
--  fmt = "blah blah"  -> return ""
--  fmt = "%.3f"       -> return "%.3f"
--  fmt = "hello %.3f" -> return "%.3f"
--  fmt = "%.3f hello" -> return "%.3f"
--- @param fmt string
local function ImParseFormatTrimDecorations(fmt)
    local fmt_start = ImParseFormatFindStart(fmt)
    if fmt_start == nil or string.byte(fmt, fmt_start) ~= 37 then -- '%'
        return ""
    end
    local fmt_end = ImParseFormatFindEnd(fmt, fmt_start)
    if fmt_end > #fmt then -- If we only have leading decoration, we don't need to copy the data.
        return string.sub(fmt, fmt_start)
    end
    return string.sub(fmt, fmt_start, fmt_end - 1)
end

-- - For scanning we need to remove all width and precision fields and flags "%+3.7f" -> "%f". BUT don't strip types like "%I64d" which includes digits. ! "%07I64d" -> "%I64d"
--- @param fmt_in       string
--- @param fmt_out      char[]
--- @param fmt_out_size size_t
function ImParseFormatSanitizeForScanning(fmt_in, fmt_out, fmt_out_size)
    local fmt_end = ImParseFormatFindEnd(fmt_in, 1)
    -- IM_UNUSED(fmt_out_size)
    IM_ASSERT(fmt_end < fmt_out_size) -- Format is too long, let us know if this happens to you!
    local has_type = false
    local fmt_in_begin = 1
    local fmt_out_begin = 1
    while fmt_in_begin < fmt_end do
        repeat
        local c = string.byte(fmt_in, fmt_in_begin, fmt_in_begin)
        fmt_in_begin = fmt_in_begin + 1

        if (not has_type and ((c >= 48 and c <= 57) or c == 46 or c == 43 or c == 35)) then
            break
        end

        has_type = has_type or ((c >= 97 and c <= 122) or (c >= 65 and c <= 90)) -- Stop skipping digits
        if c ~= 39 and c ~= 36 and c ~= 95 then -- Custom flags provided by stb_sprintf.h. POSIX 2008 also supports '.
            fmt_out[fmt_out_begin] = c
            fmt_out_begin = fmt_out_begin + 1
        end

        until true
    end
    -- fmt_out[fmt_out_begin] = 0 -- Zero-terminate
    return string.char(unpack(fmt_out)) -- FIXME: not ideal
end

--- @param str string
--- @param pos int
local function ImAtoi(str, pos)
    local negative = false
    if string.byte(str, pos) == 45 then -- '-'
        negative = true
        pos = pos + 1
    end
    if string.byte(str, pos) == 43 then -- '+'
        pos = pos + 1
    end
    local len = #str
    local v = 0
    local c = string.byte(str, pos)
    while c >= 48 and c <= 57 do
        v = v * 10 + c - 48
        pos = pos + 1
        c = string.byte(str, pos)
        if pos > len then break end
    end
    return negative and -v or v, pos
end

-- Parse display precision back from the display format string
-- FIXME: This is still used by some navigation code path to infer a minimum tweak step, but we should aim to rework widgets so it isn't needed.
--- @param fmt               string
--- @param default_precision int
local function ImParseFormatPrecision(fmt, default_precision)
    local pos = ImParseFormatFindStart(fmt)
    if not pos then
        return default_precision
    end
    pos = pos + 1
    local len = #fmt
    local c = string.byte(fmt, pos)
    while c >= 48 and c <= 57 do
        pos = pos + 1
        c = string.byte(fmt, pos)
        if pos > len then break end
    end
    local precision = INT_MAX
    if c == 46 then -- '.'
        precision, pos = ImAtoi(fmt, pos + 1)
        if precision < 0 or precision > 99 then
            precision = default_precision
        end
    end
    c = string.byte(fmt, pos)
    if c == 101 or c == 69 then -- Maximum precision with scientific notation
        precision = -1
    end
    if (c == 103 or c == 71) and precision == INT_MAX then
        precision = -1
    end
    return (precision == INT_MAX) and default_precision or precision
end

-- Create text input in place of another active widget (e.g. used when doing a Ctrl+Click on drag/slider widgets)
-- - This must be submitted right after the item it is overlaying.
-- FIXME: Facilitate using this in variety of other situations.
--- @param bb        ImRect
--- @param id        ImGuiID
--- @param label     string
--- @param buf       char[]
--- @param buf_size  int
--- @param flags?    ImGuiInputTextFlags
--- @param callback? ImGuiInputTextCallback
--- @param user_data any
function ImGui.TempInputText(bb, id, label, buf, buf_size, flags, callback, user_data)
    if flags == nil then flags = 0 end

    -- On the first frame, g.TempInputTextId == 0, then on subsequent frames it becomes == id.
    -- We clear ActiveID on the first frame to allow the InputText() taking it back.
    local g = GImGui
    local window = g.CurrentWindow

    local is_deactivated = (g.InputTextDeactivatedState.ID == id)
    local is_active = (g.TempInputId == id)
    if (not is_active and not is_deactivated) then
        ImGui.ClearActiveID()
    end

    local backup_pos = ImVec2()
    ImVec2_Copy(backup_pos, window.DC.CursorPos)
    ImVec2_Copy(window.DC.CursorPos, bb.Min)
    g.LastItemData.ItemFlags = bit32.bor(g.LastItemData.ItemFlags, ImGuiItemFlags.AllowDuplicateId) -- Using ImGuiInputTextFlags.MergedItem above will skip ItemAdd() so we poke here.
    local value_changed = ImGui.InputTextEx(label, nil, buf, buf_size, bb:GetSize(), bit32.bor(flags, ImGuiInputTextFlags.TempInput, ImGuiInputTextFlags.AutoSelectAll), callback, user_data)
    ImGui.KeepAliveID(id) -- Not done because of ImGuiInputTextFlags.TempInput
    if (not is_active and not is_deactivated) then
        -- First frame we started displaying the InputText widget, we expect it to take the active id.
        IM_ASSERT(g.ActiveId == id)
        g.TempInputId = g.ActiveId
    end
    if is_active and g.ActiveId ~= id then
        g.TempInputId = 0
    end
    ImVec2_Copy(window.DC.CursorPos, backup_pos)

    return value_changed
end

-- Note that Drag/Slider functions are only forwarding the min/max values clamping values if the ImGuiSliderFlags.AlwaysClamp flag is set!
-- This is intended: this way we allow Ctrl+Click manual input to set a value out of bounds, for maximum flexibility.
-- However this may not be ideal for all uses, as some user code may break on out of bound values.
--- @param bb         ImRect
--- @param id         ImGuiID
--- @param label      string
--- @param data_type  ImGuiDataType
--- @param data       number
--- @param format     string
--- @param clamp_min? number
--- @param clamp_max? number
function ImGui.TempInputScalar(bb, id, label, data_type, data, format, clamp_min, clamp_max)
    -- FIXME: May need to clarify display behavior if format doesn't contain %.
    -- "%d" -> "%d" / "There are %d items" -> "%d" / "items" -> "%d" (fallback). Also see #6405
    local g = GImGui
    local type_info = ImGui.DataTypeGetInfo(data_type)
    local data_buf, data_buf_size = {}, 32
    format = ImParseFormatTrimDecorations(format)
    if format == "" then
        format = type_info.PrintFmt
    end
    ImGui.DataTypeFormatString(data_buf, data_buf_size, data_type, data, format)
    ImStd.ImStrTrimBlanks(data_buf)

    local flags = bit32.bor(ImGuiInputTextFlags.AutoSelectAll, ImGuiInputTextFlags.LocalizeDecimalPoint)
    g.LastItemData.ItemFlags = bit32.bor(g.LastItemData.ItemFlags, ImGuiItemFlags.NoMarkEdited) -- Because TempInputText() uses ImGuiInputTextFlags.MergedItem it doesn't submit a new item, so we poke LastItemData.
    g.LastItemData.ItemFlags = (bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.LiveEditOnInputScalar) ~= 0) and bit32.bor(g.LastItemData.ItemFlags, ImGuiItemFlags.LiveEditOnInputText) or bit32.band(g.LastItemData.ItemFlags, bit32.bnot(ImGuiItemFlags.LiveEditOnInputText))
    if not ImGui.TempInputText(bb, id, label, data_buf, data_buf_size, flags) then
        return data, false
    end

    -- Backup old value
    local data_backup = data

    -- Apply new value (or operations) then clamp
    data = ImGui.DataTypeApplyFromText(data_buf, data_type, data, format, nil)
    if clamp_min or clamp_max then
        if clamp_min and clamp_max and ImGui.DataTypeCompare(data_type, clamp_min, clamp_max) > 0 then
            clamp_min, clamp_max = clamp_max, clamp_min
        end
        data = ImGui.DataTypeClamp(data_type, data, clamp_min, clamp_max)
    end

    -- Only mark as edited if new value is different
    g.LastItemData.ItemFlags = bit32.band(g.LastItemData.ItemFlags, bit32.bnot(ImGuiItemFlags.NoMarkEdited))
    local value_changed = data_backup ~= data
    if value_changed then
        ImGui.MarkItemEdited(id)
    end

    return data, value_changed
end

-- Note: data is passed by value and the new value is returned: Returns (data, value_changed). For an Input widget, step and step_fast are optional.
-- Read code of e.g. InputFloat(), InputInt() etc. or examples in 'Demo->Widgets->Data Types' to understand how to use this function directly.
--- @param label      string
--- @param data_type  ImGuiDataType
--- @param data       number
--- @param step?      number
--- @param step_fast? number
--- @param format?    string
--- @param flags?     ImGuiInputTextFlags
function ImGui.InputScalar(label, data_type, data, step, step_fast, format, flags)
    if flags == nil then flags = 0 end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return data, false
    end

    local g = GImGui
    local style = g.Style
    -- IM_ASSERT((flags & ImGuiInputTextFlags.EnterReturnsTrue) == 0) -- Not supported by InputScalar(). Please open an issue if you this would be useful to you. Otherwise use IsItemDeactivatedAfterEdit()!

    if format == nil then
        format = ImGui.DataTypeGetInfo(data_type).PrintFmt
    end

    local data_default = (bit32.band(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasRefVal) ~= 0) and g.NextItemData.RefVal or g.DataTypeZeroValue

    local buf, buf_size = {}, 64 -- TODO: IM_COUNTOF()
    if bit32.band(flags, ImGuiInputTextFlags.DisplayEmptyRefVal) ~= 0 and ImGui.DataTypeCompare(data_type, data, data_default) == 0 then
        buf[1] = 0
    else
        ImGui.DataTypeFormatString(buf, buf_size, data_type, data, format)
    end

    -- Disable the MarkItemEdited() call in InputText but keep ImGuiItemStatusFlags.Edited.
    -- We call MarkItemEdited() ourselves by comparing the actual data rather than the string.
    g.NextItemData.ItemFlagsSet = bit32.bor(g.NextItemData.ItemFlagsSet, ImGuiItemFlags.NoMarkEdited)
    flags = bit32.bor(flags, ImGuiInputTextFlags.AutoSelectAll, ImGuiInputTextFlags.LocalizeDecimalPoint)

    local has_step_buttons = (step ~= nil)
    local button_size = has_step_buttons and ImGui.GetFrameHeight() or 0.0
    local ret
    if has_step_buttons then
        -- With Step Buttons
        ImGui.BeginGroup() -- The only purpose of the group here is to allow the caller to query item data e.g. IsItemActive()
        ImGui.PushID(label)
        ImGui.SetNextItemWidth(ImMax(1.0, ImGui.CalcItemWidth() - (button_size + style.ItemInnerSpacing.x) * 2))
        ret = ImGui.InputText("", buf, buf_size, flags) -- PushID(label) + "" gives us the expected ID from outside point of view
        -- IMGUI_TEST_ENGINE_ITEM_INFO()
    else
        -- Without Step Buttons
        ret = ImGui.InputText(label, buf, buf_size, flags)
    end

    -- Apply
    local value_changed = false
    if bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.LiveEditOnInputScalar) ~= 0 then
        local input_edited = bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.EditedInternal) ~= 0 -- We would be using 'ret' if ImGuiInputTextFlags.EnterReturnsTrue was not involved.
        if input_edited then
            data, value_changed = ImGui.DataTypeApplyFromText(buf, data_type, data, format, bit32.band(flags, ImGuiInputTextFlags.ParseEmptyRefVal) ~= 0 and data_default or nil)
        end
    else
        -- g.LastItemData.StatusFlags &= ~ImGuiItemStatusFlags_Edited
        if (g.DeactivatedItemData.ID == g.LastItemData.ID) then
            -- g.DeactivatedItemData.HasBeenEditedBefore = false; // Will be set below by MarkItemEdited()
            -- if (IsItemDeactivated()) // Should be unnecessary
            data, value_changed = ImGui.DataTypeApplyFromText(buf, data_type, data, format, bit32.band(flags, ImGuiInputTextFlags.ParseEmptyRefVal) ~= 0 and data_default or nil)
        end
    end

    -- Step buttons
    if has_step_buttons then
        local backup_frame_padding = ImVec2()
        ImVec2_Copy(backup_frame_padding, style.FramePadding)
        style.FramePadding.x = style.FramePadding.y
        if bit32.band(flags, ImGuiInputTextFlags.ReadOnly) ~= 0 then
            ImGui.BeginDisabled()
        end
        ImGui.PushItemFlag(ImGuiItemFlags.ButtonRepeat, true)
        ImGui.SameLine(0, style.ItemInnerSpacing.x)
        --- @cast step number
        if ImGui.ButtonEx("-", ImVec2(button_size, button_size)) then
            data = ImGui.DataTypeApplyOp(data_type, 45, data, ((g.IO.KeyCtrl and step_fast) and step_fast or step))
            value_changed = true
            ret = true
        end
        ImGui.SameLine(0, style.ItemInnerSpacing.x)
        if ImGui.ButtonEx("+", ImVec2(button_size, button_size)) then
            data = ImGui.DataTypeApplyOp(data_type, 43, data, ((g.IO.KeyCtrl and step_fast) and step_fast or step))
            value_changed = true
            ret = true
        end
        ImGui.PopItemFlag()
        if bit32.band(flags, ImGuiInputTextFlags.ReadOnly) ~= 0 then
            ImGui.EndDisabled()
        end
        local label_end = ImGui.FindRenderedTextEnd(label)
        if label_end ~= 1 then
            ImGui.SameLine(0, style.ItemInnerSpacing.x)
            ImGui.TextEx(label, label_end)
        end
        ImVec2_Copy(style.FramePadding, backup_frame_padding)

        ImGui.PopID()
        ImGui.EndGroup()
    end

    g.LastItemData.ItemFlags = bit32.band(g.LastItemData.ItemFlags, bit32.bnot(ImGuiItemFlags.NoMarkEdited))
    if value_changed then
        ImGui.MarkItemEdited(g.LastItemData.ID)
    end

    if bit32.band(flags, ImGuiInputTextFlags.EnterReturnsTrue) ~= 0 then
        return data, ret
    end
    return data, value_changed
end

--- @param label      string
--- @param data_type  ImGuiDataType
--- @param data       number[]
--- @param components int
--- @param step?      number
--- @param step_fast? number
--- @param format?    string
--- @param flags?     ImGuiInputTextFlags
function ImGui.InputScalarN(label, data_type, data, components, step, step_fast, format, flags)
    if flags == nil then flags = 0 end
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local value_changed = false
    ImGui.BeginGroup()
    ImGui.PushID(label)
    ImGui.PushMultiItemsWidths(components, ImGui.CalcItemWidth())
    for i = 1, components do
        ImGui.PushID(i - 1)
        if i > 1 then
            ImGui.SameLine(0, g.Style.ItemInnerSpacing.x)
        end
        local changed
        data[i], changed = ImGui.InputScalar("", data_type, data[i], step, step_fast, format, flags)
        if changed then
            value_changed = true
        end
        ImGui.PopID()
        ImGui.PopItemWidth()
    end
    ImGui.PopID()

    local label_end = ImGui.FindRenderedTextEnd(label)
    if label_end > 1 then
        ImGui.SameLine(0.0, g.Style.ItemInnerSpacing.x)
        ImGui.TextEx(label, label_end)
    end

    ImGui.EndGroup()
    return value_changed
end

--- @param label   string
--- @param v       [float, float, float]
--- @param format? string
--- @param flags?  ImGuiInputTextFlags
function ImGui.InputFloat3(label, v, format, flags)
    if format == nil then format = "%.3f" end

    return ImGui.InputScalarN(label, ImGuiDataType.Float, v, 3, nil, nil, format, flags)
end

function ImGui.InputFloat2(label, v, format, flags)
    return ImGui.InputScalarN(label, ImGuiDataType.Float, v, 2, nil, nil, format or "%.3f", flags)
end

function ImGui.InputFloat4(label, v, format, flags)
    return ImGui.InputScalarN(label, ImGuiDataType.Float, v, 4, nil, nil, format or "%.3f", flags)
end

function ImGui.InputInt2(label, v, flags)
    return ImGui.InputScalarN(label, ImGuiDataType.S32, v, 2, nil, nil, "%d", flags)
end

function ImGui.InputInt3(label, v, flags)
    return ImGui.InputScalarN(label, ImGuiDataType.S32, v, 3, nil, nil, "%d", flags)
end

function ImGui.InputInt4(label, v, flags)
    return ImGui.InputScalarN(label, ImGuiDataType.S32, v, 4, nil, nil, "%d", flags)
end

--- @param label      string
--- @param v          int
--- @param step?      int
--- @param step_fast? int
--- @param flags?     ImGuiInputTextFlags
function ImGui.InputInt(label, v, step, step_fast, flags)
    if step      == nil then step      = 1   end
    if step_fast == nil then step_fast = 100 end
    if flags     == nil then flags     = 0   end

    -- Hexadecimal input provided as a convenience but the flag name is awkward. Typically you'd use InputText() to parse your own data, if you want to handle prefixes.
    local format = (bit32.band(flags, ImGuiInputTextFlags.CharsHexadecimal) ~= 0) and "%08X" or "%d"
    return ImGui.InputScalar(label, ImGuiDataType.S32, v, (step > 0) and step or nil, (step_fast > 0) and step_fast or nil, format, flags)
end

--- @param label      string
--- @param v          float
--- @param step?      float
--- @param step_fast? float
--- @param format?    string
--- @param flags?     ImGuiInputTextFlags
function ImGui.InputFloat(label, v, step, step_fast, format, flags)
    if step      == nil then step      = .0     end
    if step_fast == nil then step_fast = .0     end
    if format    == nil then format    = "%.3f" end

    return ImGui.InputScalar(label, ImGuiDataType.Float, v, (step > 0.0 and step or nil), (step_fast > 0.0 and step_fast or nil), format, flags)
end

--- @param label      string
--- @param v          double
--- @param step?      double
--- @param step_fast? double
--- @param format?    string
--- @param flags?     ImGuiInputTextFlags
function ImGui.InputDouble(label, v, step, step_fast, format, flags)
    if step      == nil then step      = .0     end
    if step_fast == nil then step_fast = .0     end
    if format    == nil then format    = "%.6f" end

    return ImGui.InputScalar(label, ImGuiDataType.Double, v, (step > 0.0 and step or nil), (step_fast > 0.0 and step_fast or nil), format, flags)
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: DragScalar, DragFloat, DragInt, etc.
-------------------------------------------------------------------------------
-- - DragBehaviorT<>() [Internal]
-- - DragBehavior() [Internal]
-- - DragScalar()
-- - DragScalarN()
-- - DragFloat()
-- - DragFloat2()
-- - DragFloat3()
-- - DragFloat4()
-- - DragFloatRange2()
-- - DragInt()
-- - DragInt2()
-- - DragInt3()
-- - DragInt4()
-- - DragIntRange2()
-------------------------------------------------------------------------------

-- This is called by DragBehavior() when the widget is active (held by mouse or being manipulated with Nav controls)
--- @generic T : number
--- @param TYPE       fun(val: number): T
--- @param SIGNEDTYPE fun(val: number): T
--- @param data_type  ImGuiDataType
--- @param v          T
--- @param v_speed    float
--- @param v_min      T
--- @param v_max      T
--- @param format     string
--- @param flags      ImGuiSliderFlags
--- @return T    new_v   # Updated `v`
--- @return bool changed
function ImGui.DragBehaviorT(TYPE, SIGNEDTYPE, data_type, v, v_speed, v_min, v_max, format, flags)
    local g = GImGui
    local axis = (bit32.band(flags, ImGuiSliderFlags.Vertical) ~= 0) and ImGuiAxis.Y or ImGuiAxis.X
    local is_bounded = (v_min < v_max) or ((v_min == v_max) and (v_min ~= 0.0 or (bit32.band(flags, ImGuiSliderFlags.ClampZeroRange) ~= 0)))
    local is_wrapped = is_bounded and (bit32.band(flags, ImGuiSliderFlags.WrapAround) ~= 0)
    local is_logarithmic = bit32.band(flags, ImGuiSliderFlags.Logarithmic) ~= 0
    local is_floating_point = (data_type == ImGuiDataType.Float) or (data_type == ImGuiDataType.Double)

    -- Default tweak speed
    if v_speed == 0.0 and is_bounded and (v_max - v_min < math.huge) then
        v_speed = (v_max - v_min) * g.DragSpeedDefaultRatio
    end

    -- Inputs accumulates into g.DragCurrentAccum, which is flushed into the current value as soon as it makes a difference with our precision settings
    local adjust_delta = 0.0
    if g.ActiveIdSource == ImGuiInputSource.Mouse and ImGui.IsMousePosValid() and ImGui.IsMouseDragPastThreshold(0, g.IO.MouseDragThreshold * DRAG_MOUSE_THRESHOLD_FACTOR) then
        adjust_delta = g.IO.MouseDelta[axis]
        if g.IO.KeyAlt and bit32.band(flags, ImGuiSliderFlags.NoSpeedTweaks) == 0 then
            adjust_delta = adjust_delta / 100.0
        end
        if g.IO.KeyShift and bit32.band(flags, ImGuiSliderFlags.NoSpeedTweaks) == 0 then
            adjust_delta = adjust_delta * 10.0
        end
    elseif g.ActiveIdSource == ImGuiInputSource.Keyboard or g.ActiveIdSource == ImGuiInputSource.Gamepad then
        local decimal_precision
        if is_floating_point then
            decimal_precision = ImParseFormatPrecision(format, 3)
        else
            decimal_precision = 0
        end
        local slow_key = (g.NavInputSource == ImGuiInputSource.Gamepad) and ImGuiKey.NavGamepadTweakSlow or ImGuiKey.NavKeyboardTweakSlow
        local fast_key = (g.NavInputSource == ImGuiInputSource.Gamepad) and ImGuiKey.NavGamepadTweakFast or ImGuiKey.NavKeyboardTweakFast

        local tweak_factor
        if bit32.band(flags, ImGuiSliderFlags.NoSpeedTweaks) ~= 0 then
            tweak_factor = 1.0
        elseif ImGui.IsKeyDown(slow_key) then
            tweak_factor = 1.0 / 10.0
        elseif ImGui.IsKeyDown(fast_key) then
            tweak_factor = 10.0
        else
            tweak_factor = 1.0
        end

        adjust_delta = ImGui.GetNavTweakPressedAmount(axis) * tweak_factor
        v_speed = ImMax(v_speed, GetMinimumStepAtDecimalPrecision(decimal_precision))
    end
    adjust_delta = adjust_delta * v_speed

    -- For vertical drag we currently assume that Up=higher value (like we do with vertical sliders). This may become a parameter.
    if axis == ImGuiAxis.Y then
        adjust_delta = -adjust_delta
    end

    -- For logarithmic use our range is effectively 0..1 so scale the delta into that range
    if is_logarithmic and (v_max - v_min < FLT_MAX) and (v_max - v_min > 0.000001) then  -- Epsilon to avoid /0
        adjust_delta = adjust_delta / (v_max - v_min)
    end

    -- Clear current value on activation
    -- Avoid altering values and clamping when we are _already_ past the limits and heading in the same direction, so e.g. if range is 0..255, current value is 300 and we are pushing to the right side, keep the 300.
    local is_just_activated = g.ActiveIdIsJustActivated
    local is_already_past_limits_and_pushing_outward = is_bounded and not is_wrapped and ((v >= v_max and adjust_delta > 0.0) or (v <= v_min and adjust_delta < 0.0))
    if is_just_activated or is_already_past_limits_and_pushing_outward then
        g.DragCurrentAccum = 0.0
        g.DragCurrentAccumDirty = false
    elseif adjust_delta ~= 0.0 then
        g.DragCurrentAccum = g.DragCurrentAccum + adjust_delta
        g.DragCurrentAccumDirty = true
    end

    if not g.DragCurrentAccumDirty then
        return v, false
    end

    local v_cur = (TYPE)(v)
    local v_old_ref_for_accum_remainder = 0.0

    local logarithmic_zero_epsilon = 0.0 -- Only valid when is_logarithmic is true
    local zero_deadzone_halfsize = 0.0 -- Drag widgets have no deadzone (as it doesn't make sense)
    if is_logarithmic then
        -- When using logarithmic sliders, we need to clamp to avoid hitting zero, but our choice of clamp value greatly affects slider precision. We attempt to use the specified precision to estimate a good lower bound.
        local decimal_precision
        if is_floating_point then
            decimal_precision = ImParseFormatPrecision(format, 3)
        else
            decimal_precision = 1
        end
        logarithmic_zero_epsilon = ImPow(0.1, decimal_precision)

        -- Convert to parametric space, apply delta, convert back
        local v_old_parametric = ImGui.ScaleRatioFromValueT(data_type, v_cur, v_min, v_max, logarithmic_zero_epsilon, zero_deadzone_halfsize)
        local v_new_parametric = v_old_parametric + g.DragCurrentAccum
        v_cur = ImGui.ScaleValueFromRatioT(TYPE, SIGNEDTYPE, data_type, v_new_parametric, v_min, v_max, logarithmic_zero_epsilon, zero_deadzone_halfsize)
        v_old_ref_for_accum_remainder = v_old_parametric
    else
        v_cur = (TYPE)(v_cur + (SIGNEDTYPE)(g.DragCurrentAccum))
    end

    -- Round to user desired precision based on format string
    if is_floating_point and bit32.band(flags, ImGuiSliderFlags.NoRoundToFormat) == 0 then
        v_cur = ImGui.RoundScalarWithFormatT(format, data_type, v_cur)
    end

    -- Preserve remainder after rounding has been applied. This also allow slow tweaking of values.
    g.DragCurrentAccumDirty = false
    if is_logarithmic then
        -- Convert to parametric space, apply delta, convert back
        local v_new_parametric = ImGui.ScaleRatioFromValueT(data_type, v_cur, v_min, v_max, logarithmic_zero_epsilon, zero_deadzone_halfsize)
        g.DragCurrentAccum = g.DragCurrentAccum - (v_new_parametric - v_old_ref_for_accum_remainder)
    else
        g.DragCurrentAccum = g.DragCurrentAccum - ((SIGNEDTYPE)(v_cur) - (SIGNEDTYPE)(v))
    end

    -- Lose zero sign for float/double
    if v_cur == (TYPE)(-0) then
        v_cur = (TYPE)(0)
    end

    if v ~= v_cur and is_bounded then
        if is_wrapped then
            -- Wrap values
            if v_cur < v_min then
                v_cur = (TYPE)(v_cur + (TYPE)((TYPE)(v_max - v_min) + (is_floating_point and 0 or 1)))
            end
            if v_cur > v_max then
                v_cur = (TYPE)(v_cur - (TYPE)((TYPE)(v_max - v_min) - (is_floating_point and 0 or 1)))
            end
        else
            -- Clamp values + handle overflow/wrap-around for integer types.
            if v_cur < v_min or (v_cur > v and adjust_delta < 0.0 and not is_floating_point) then
                v_cur = (TYPE)(v_min)
            end
            if v_cur > v_max or (v_cur < v and adjust_delta > 0.0 and not is_floating_point) then
                v_cur = (TYPE)(v_max)
            end
        end
    end

    -- Apply result
    if v == v_cur then
        return v, false
    end
    v = v_cur
    return v, true
end

--- @param id        ImGuiID
--- @param data_type ImGuiDataType
--- @param v         number
--- @param v_speed   float
--- @param min       number
--- @param max       number
--- @param format    string
--- @param flags     ImGuiSliderFlags

function ImGui.DragBehavior(id, data_type, v, v_speed, min, max, format, flags)
    -- Read imgui.cpp "API BREAKING CHANGES" section for 1.78 if you hit this assert.
    IM_ASSERT((flags == 1 or bit32.band(flags, ImGuiSliderFlags.InvalidMask_) == 0), "Invalid ImGuiSliderFlags flags! Has the legacy 'float power' argument been mistakenly cast to flags? Call function with ImGuiSliderFlags_Logarithmic flags instead.")

    -- Things we can do easily outside the DragBehaviorT<> template, saves code generation.
    local g = GImGui
    if g.ActiveId == id then
        if g.ActiveIdSource == ImGuiInputSource.Mouse and not g.IO.MouseDown[0] then
            ImGui.ClearActiveID()
        elseif (g.ActiveIdSource == ImGuiInputSource.Keyboard or g.ActiveIdSource == ImGuiInputSource.Gamepad) and g.NavActivatePressedId == id and not g.ActiveIdIsJustActivated then
            ImGui.ClearActiveID()
        end
    end
    if g.ActiveId ~= id then
        return v, false
    end
    if bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.ReadOnly) ~= 0 or bit32.band(flags, ImGuiSliderFlags.ReadOnly) ~= 0 then
        return v, false
    end

    if data_type == ImGuiDataType.S8 then
        return ImGui.DragBehaviorT(ImS32, ImS32, ImGuiDataType.S32, v, v_speed, min and min or IM_S8_MIN, max and max or IM_S8_MAX, format, flags)
    elseif data_type == ImGuiDataType.U8 then
        return ImGui.DragBehaviorT(ImU32, ImS32, ImGuiDataType.U32, v, v_speed, min and min or IM_U8_MIN, max and max or IM_U8_MAX, format, flags)
    elseif data_type == ImGuiDataType.S16 then
        return ImGui.DragBehaviorT(ImS32, ImS32, ImGuiDataType.S32, v, v_speed, min and min or IM_S16_MIN, max and max or IM_S16_MAX, format, flags)
    elseif data_type == ImGuiDataType.U16 then
        return ImGui.DragBehaviorT(ImU32, ImS32, ImGuiDataType.U32, v, v_speed, min and min or IM_U16_MIN, max and max or IM_U16_MAX, format, flags)
    elseif data_type == ImGuiDataType.S32 then
        return ImGui.DragBehaviorT(ImS32, ImS32, data_type, v, v_speed, min and min or IM_S32_MIN, max and max or IM_S32_MAX, format, flags)
    elseif data_type == ImGuiDataType.U32 then
        return ImGui.DragBehaviorT(ImU32, ImS32, data_type, v, v_speed, min and min or IM_U32_MIN, max and max or IM_U32_MAX, format, flags)
    elseif data_type == ImGuiDataType.Float then
        return ImGui.DragBehaviorT(float, float, data_type, v, v_speed, min and min or -FLT_MAX, max and max or FLT_MAX, format, flags)
    elseif data_type == ImGuiDataType.Double then
        return ImGui.DragBehaviorT(double, double, data_type, v, v_speed, min and min or -DBL_MAX, max and max or DBL_MAX, format, flags)
    end

    IM_ASSERT(false)
    return v, false
end

-- Only clamp Ctrl+Click input when ImGuiSliderFlags.ClampOnInput is set (generally via ImGuiSliderFlags.AlwaysClamp)
--- @param flags     ImGuiSliderFlags
--- @param data_type ImGuiDataType
--- @param min       number
--- @param max       number
local function TempInputIsClampEnabled(flags, data_type, min, max)
    if bit32.band(flags, ImGuiSliderFlags.ClampOnInput) ~= 0 and (min ~= nil or max ~= nil) then
        local clamp_range_dir = 0
        if min ~= nil and max ~= nil then
            clamp_range_dir = ImGui.DataTypeCompare(data_type, min, max) -- -1 when min < max, == 0 when min == max
        end
        if min == nil or max == nil or clamp_range_dir < 0 then
            return true
        end
        if clamp_range_dir == 0 then
            return ImGui.DataTypeIsZero(data_type, min) and (bit32.band(flags, ImGuiSliderFlags.ClampZeroRange) ~= 0) or true
        end
    end
    return false
end

--- @param label     string
--- @param data_type ImGuiDataType
--- @param data      number
--- @param v_speed   float
--- @param min       number
--- @param max       number
--- @param format    string
--- @param flags     ImGuiSliderFlags
-- [Luau] memo of string.format(format, value) for drag/slider value text (same values are redrawn every frame).
-- ponytail: whole-memo reset at 4096 entries, LRU if values churn
local fmt_memo, fmt_memo_n = {}, 0
local SliderScalar_total_bb, SliderScalar_grab_bb = ImRect(), ImRect() -- [Luau] scratch for SliderScalar()/DragScalar(), never escape
local DRAG_TEXT_ALIGN = ImVec2(0.5, 0.5)
function FormatCached(format, v)
    local m = fmt_memo[format]
    if m == nil then m = {}; fmt_memo[format] = m end
    local r = m[v]
    if r == nil then
        if fmt_memo_n >= 4096 then table.clear(fmt_memo); m = {}; fmt_memo[format] = m; fmt_memo_n = 0 end
        r = ImFormatString(format, v); m[v] = r; fmt_memo_n = fmt_memo_n + 1
    end
    return r
end

-- Note: data is passed by value and the new value is returned: Returns (data, value_changed). For a Drag widget, min and max are optional.
-- Read code of e.g. DragFloat(), DragInt() etc. or examples in 'Demo->Widgets->Data Types' to understand how to use this function directly.

function ImGui.DragScalar(label, data_type, data, v_speed, min, max, format, flags)
    if v_speed == nil then v_speed = 1.0 end
    if flags == nil then flags = 0 end
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return data, false
    end

    local g = GImGui
    local style = g.Style
    local id = window:GetID(label)
    local w = ImGui.CalcItemWidth()
    local color_marker = (bit32.band(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasColorMarker) ~= 0) and g.NextItemData.ColorMarker or 0

    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)
    local cursor = window.DC.CursorPos
    local frame_bb = ImRect(cursor.x, cursor.y, cursor.x + w, cursor.y + (label_size.y + style.FramePadding.y * 2.0)) -- [Luau] no temporary ImVec2
    local total_bb = SliderScalar_total_bb -- [Luau] scratch: ItemSize()/ItemAdd() only read it
    total_bb.Min.x = frame_bb.Min.x; total_bb.Min.y = frame_bb.Min.y
    total_bb.Max.x = frame_bb.Max.x + ((label_size.x > 0.0) and (style.ItemInnerSpacing.x + label_size.x) or 0.0); total_bb.Max.y = frame_bb.Max.y + 0.0

    local temp_input_allowed = (bit32.band(flags, ImGuiSliderFlags.NoInput) == 0)
    ImGui.ItemSize(total_bb, style.FramePadding.y)
    if not ImGui.ItemAdd(total_bb, id, frame_bb, temp_input_allowed and ImGuiItemFlags.Inputable or 0) then
        return data, false
    end

    -- Default format string when passing NULL
    if format == nil then
        format = ImGui.DataTypeGetInfo(data_type).PrintFmt
    end

    local hovered = ImGui.ItemHoverable(frame_bb, id, g.LastItemData.ItemFlags)
    local temp_input_is_active = temp_input_allowed and ImGui.TempInputIsActive(id)
    if not temp_input_is_active then
        -- Tabbing or Ctrl+Click on Drag turns it into an InputText
        local clicked = hovered and ImGui.IsMouseClickedEx(0, ImGuiInputFlags.None, id)
        local double_clicked = (hovered and g.IO.MouseClickedCount[0] == 2 and ImGui.TestKeyOwner(ImGuiKey.MouseLeft, id))
        local make_active = (clicked or double_clicked or g.NavActivateId == id)
        if make_active and (clicked or double_clicked) then
            ImGui.SetKeyOwner(ImGuiKey.MouseLeft, id)
        end
        if make_active and temp_input_allowed then
            if (clicked and g.IO.KeyCtrl) or double_clicked or (g.NavActivateId == id and bit32.band(g.NavActivateFlags, ImGuiActivateFlags.PreferInput) ~= 0) then
                temp_input_is_active = true
            end
        end

        -- (Optional) simple click (without moving) turns Drag into an InputText
        if g.IO.ConfigDragClickToInputText and temp_input_allowed and not temp_input_is_active then
            if g.ActiveId == id and hovered and g.IO.MouseReleased[0] and not ImGui.IsMouseDragPastThreshold(0, g.IO.MouseDragThreshold * DRAG_MOUSE_THRESHOLD_FACTOR) then
                g.NavActivateId = id
                g.NavActivateFlags = ImGuiActivateFlags.PreferInput
                temp_input_is_active = true
            end
        end

        -- Store initial value (not used by main lib but available as a convenience but some mods e.g. to revert)
        if make_active then
            g.ActiveIdValueOnActivation = data
        end

        if make_active and not temp_input_is_active then
            ImGui.SetActiveID(id, window)
            ImGui.SetFocusID(id, window)
            ImGui.FocusWindow(window)
            g.ActiveIdUsingNavDirMask = bit32.bor(bit32.lshift(1, ImGuiDir.Left), bit32.lshift(1, ImGuiDir.Right))
        end
    end

    if temp_input_is_active then
        local clamp_enabled = TempInputIsClampEnabled(flags, data_type, min, max)
        return ImGui.TempInputScalar(frame_bb, id, label, data_type, data, format, clamp_enabled and min or nil, clamp_enabled and max or nil)
    end

    -- Draw frame
    local frame_col = ImGui.GetColorU32(g.ActiveId == id and ImGuiCol.FrameBgActive or hovered and ImGuiCol.FrameBgHovered or ImGuiCol.FrameBg)
    ImGui.RenderNavCursor(frame_bb, id)
    ImGui.RenderFrame(frame_bb.Min, frame_bb.Max, frame_col, false, style.FrameRounding)

    if color_marker ~= 0 and style.ColorMarkerSize > 0.0 then
        ImGui.RenderColorComponentMarker(frame_bb, ImGui.GetColorU32(color_marker, nil, true), style.FrameRounding)
    end

    ImGui.RenderFrameBorder(frame_bb.Min, frame_bb.Max, g.Style.FrameRounding)

    -- Drag behavior
    local value_changed
    data, value_changed = ImGui.DragBehavior(id, data_type, data, v_speed, min, max, format, flags)
    if value_changed then
        ImGui.MarkItemEdited(id)
    end

    -- TODO: ImGui.DataTypeFormatString() should be used here instead of ImFormatString()

    -- Display value using user-provided display format so user can add prefix/suffix/decorations to the value.
    ImGui.RenderTextClipped(frame_bb.Min, frame_bb.Max, FormatCached(format, data), nil, nil, DRAG_TEXT_ALIGN)

    if label_size.x > 0.0 then
        ImGui.RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y), label, 1, label_end, false)
    end

    return data, value_changed
end

--- @param label    string
--- @param v        float
--- @param v_speed? float
--- @param v_min?   float
--- @param v_max?   float
--- @param format?  string
--- @param flags?   ImGuiSliderFlags
function ImGui.DragFloat(label, v, v_speed, v_min, v_max, format, flags)
    if v_speed == nil then v_speed = 1.0    end
    if v_min   == nil then v_min   = 0.0    end
    if v_max   == nil then v_max   = 0.0    end
    if format  == nil then format  = "%.3f" end
    if flags   == nil then flags   = 0      end

    return ImGui.DragScalar(label, ImGuiDataType.Float, v, v_speed, v_min, v_max, format, flags)
end

-- NB: v_speed is float to allow adjusting the drag speed with more precision
--- @param label    string
--- @param v        int
--- @param v_speed? float
--- @param v_min?   int
--- @param v_max?   int
--- @param format?  string
--- @param flags?   ImGuiSliderFlags

function ImGui.DragInt(label, v, v_speed, v_min, v_max, format, flags)
    if v_speed == nil then v_speed = 1.0  end
    if v_min   == nil then v_min   = 0    end
    if v_max   == nil then v_max   = 0    end
    if format  == nil then format  = "%d" end
    if flags   == nil then flags   = 0    end

    return ImGui.DragScalar(label, ImGuiDataType.S32, v, v_speed, v_min, v_max, format, flags)
end

-- `v` is mutated in place (1-based), returns value_changed
function ImGui.DragScalarN(label, data_type, v, components, v_speed, v_min, v_max, format, flags)
    if v_speed == nil then v_speed = 1.0 end
    if flags == nil then flags = 0 end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local value_changed = false
    ImGui.BeginGroup()
    ImGui.PushID(label)
    ImGui.PushMultiItemsWidths(components, ImGui.CalcItemWidth())
    for i = 1, components do
        ImGui.PushID(i - 1)
        if i > 1 then
            ImGui.SameLine(0, g.Style.ItemInnerSpacing.x)
        end
        if bit32.band(flags, ImGuiSliderFlags.ColorMarkers) ~= 0 then
            ImGui.SetNextItemColorMarker(GDefaultRgbaColorMarkers[i])
        end
        local changed
        v[i], changed = ImGui.DragScalar("", data_type, v[i], v_speed, v_min, v_max, format, flags)
        value_changed = value_changed or changed
        ImGui.PopID()
        ImGui.PopItemWidth()
    end
    ImGui.PopID()

    local label_end = ImGui.FindRenderedTextEnd(label)
    if label_end > 1 then
        ImGui.SameLine(0, g.Style.ItemInnerSpacing.x)
        ImGui.TextEx(label, label_end)
    end

    ImGui.EndGroup()
    return value_changed
end

local function DragFloatN(n)
    return function(label, v, v_speed, v_min, v_max, format, flags)
        return ImGui.DragScalarN(label, ImGuiDataType.Float, v, n, v_speed or 1.0, v_min or 0.0, v_max or 0.0, format or "%.3f", flags or 0)
    end
end
local function DragIntN(n)
    return function(label, v, v_speed, v_min, v_max, format, flags)
        return ImGui.DragScalarN(label, ImGuiDataType.S32, v, n, v_speed or 1.0, v_min or 0, v_max or 0, format or "%d", flags or 0)
    end
end
ImGui.DragFloat2 = DragFloatN(2)
ImGui.DragFloat3 = DragFloatN(3)
ImGui.DragFloat4 = DragFloatN(4)
ImGui.DragInt2 = DragIntN(2)
ImGui.DragInt3 = DragIntN(3)
ImGui.DragInt4 = DragIntN(4)

-- NB: You likely want to specify the ImGuiSliderFlags.AlwaysClamp when using this.
--- @return float v_current_min
--- @return float v_current_max
--- @return bool  value_changed
local function DragRange2(data_type, label, v_current_min, v_current_max, v_speed, v_min, v_max, format, format_max, flags)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return v_current_min, v_current_max, false
    end

    local g = GImGui
    local lo = (data_type == ImGuiDataType.Float) and -FLT_MAX or INT_MIN
    local hi = (data_type == ImGuiDataType.Float) and FLT_MAX or INT_MAX
    ImGui.PushID(label)
    ImGui.BeginGroup()
    ImGui.PushMultiItemsWidths(2, ImGui.CalcItemWidth())

    local min_min = (v_min >= v_max) and lo or v_min
    local min_max = (v_min >= v_max) and v_current_max or ImMin(v_max, v_current_max)
    local min_flags = bit32.bor(flags, (min_min == min_max) and ImGuiSliderFlags.ReadOnly or 0)
    local value_changed, changed
    v_current_min, value_changed = ImGui.DragScalar("##min", data_type, v_current_min, v_speed, min_min, min_max, format, min_flags)
    ImGui.PopItemWidth()
    ImGui.SameLine(0, g.Style.ItemInnerSpacing.x)

    local max_min = (v_min >= v_max) and v_current_min or ImMax(v_min, v_current_min)
    local max_max = (v_min >= v_max) and hi or v_max
    local max_flags = bit32.bor(flags, (max_min == max_max) and ImGuiSliderFlags.ReadOnly or 0)
    v_current_max, changed = ImGui.DragScalar("##max", data_type, v_current_max, v_speed, max_min, max_max, format_max or format, max_flags)
    value_changed = value_changed or changed
    ImGui.PopItemWidth()
    ImGui.SameLine(0, g.Style.ItemInnerSpacing.x)

    ImGui.TextEx(label, ImGui.FindRenderedTextEnd(label))
    ImGui.EndGroup()
    ImGui.PopID()

    return v_current_min, v_current_max, value_changed
end

function ImGui.DragFloatRange2(label, v_current_min, v_current_max, v_speed, v_min, v_max, format, format_max, flags)
    return DragRange2(ImGuiDataType.Float, label, v_current_min, v_current_max, v_speed or 1.0, v_min or 0.0, v_max or 0.0, format or "%.3f", format_max, flags or 0)
end

function ImGui.DragIntRange2(label, v_current_min, v_current_max, v_speed, v_min, v_max, format, format_max, flags)
    return DragRange2(ImGuiDataType.S32, label, v_current_min, v_current_max, v_speed or 1.0, v_min or 0, v_max or 0, format or "%d", format_max, flags or 0)
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: SliderScalar, SliderFloat, SliderInt, etc.
-------------------------------------------------------------------------------
-- - ScaleRatioFromValueT<> [Internal]
-- - ScaleValueFromRatioT<> [Internal]
-- - SliderBehaviorT<>() [Internal]
-- - SliderBehavior() [Internal]
-- - SliderScalar()
-- - SliderScalarN()
-- - SliderFloat()
-- - SliderFloat2()
-- - SliderFloat3()
-- - SliderFloat4()
-- - SliderAngle()
-- - SliderInt()
-- - SliderInt2()
-- - SliderInt3()
-- - SliderInt4()
-- - VSliderScalar()
-- - VSliderFloat()
-- - VSliderInt()
-------------------------------------------------------------------------------

-- Convert a value v in the output space of a slider into a parametric position on the slider itself (the logical opposite of ScaleValueFromRatioT)
--- @param data_type                ImGuiDataType
--- @param v                        number
--- @param v_min                    number
--- @param v_max                    number
--- @param logarithmic_zero_epsilon float
--- @param zero_deadzone_halfsize   float
function ImGui.ScaleRatioFromValueT(data_type, v, v_min, v_max, logarithmic_zero_epsilon, zero_deadzone_halfsize)
    if v_min == v_max then
        return 0.0
    end
    -- IM_UNUSED(data_type)

    local v_clamped
    if v_min < v_max then
        v_clamped = ImClamp(v, v_min, v_max)
    else
        v_clamped = ImClamp(v, v_max, v_min)
    end
    if logarithmic_zero_epsilon > 0.0 then -- == is_logarithmic from caller
        local flipped = v_max < v_min
        if flipped then -- Handle the case where the range is backwards
            v_min, v_max = v_max, v_min
        end

        -- Fudge min/max to avoid getting close to log(0)
        local v_min_fudged
        if ImAbs(v_min) < logarithmic_zero_epsilon then
            v_min_fudged = (v_min < 0.0) and -logarithmic_zero_epsilon or logarithmic_zero_epsilon
        else
            v_min_fudged = v_min
        end
        local v_max_fudged
        if ImAbs(v_max) < logarithmic_zero_epsilon then
            v_max_fudged = (v_max < 0.0) and -logarithmic_zero_epsilon or logarithmic_zero_epsilon
        else
            v_max_fudged = v_max
        end

        -- Awkward special cases - we need ranges of the form (-100 .. 0) to convert to (-100 .. -epsilon), not (-100 .. epsilon)
        if v_min == 0.0 and v_max < 0.0 then
            v_min_fudged = -logarithmic_zero_epsilon
        elseif v_max == 0.0 and v_min < 0.0 then
            v_max_fudged = -logarithmic_zero_epsilon
        end

        local result
        if v_clamped <= v_min_fudged then
            result = 0.0 -- Workaround for values that are in-range but below our fudge
        elseif v_clamped >= v_max_fudged then
            result = 1.0 -- Workaround for values that are in-range but above our fudge
        elseif v_min * v_max < 0.0 then -- Range crosses zero, so split into two portions
            local zero_point_center = (-v_min) / (v_max - v_min) -- The zero point in parametric space.  There's an argument we should take the logarithmic nature into account when calculating this, but for now this should do (and the most common case of a symmetrical range works fine)
            local zero_point_snap_L = zero_point_center - zero_deadzone_halfsize
            local zero_point_snap_R = zero_point_center + zero_deadzone_halfsize
            if v == 0.0 then
                result = zero_point_center -- Special case for exactly zero
            elseif v < 0.0 then
                result = (1.0 - (ImLog(-v_clamped / logarithmic_zero_epsilon) / ImLog(-v_min_fudged / logarithmic_zero_epsilon))) * zero_point_snap_L
            else
                result = zero_point_snap_R + ((ImLog(v_clamped / logarithmic_zero_epsilon) / ImLog(v_max_fudged / logarithmic_zero_epsilon)) * (1.0 - zero_point_snap_R))
            end
        elseif v_min < 0.0 or v_max < 0.0 then -- Entirely negative slider
            result = 1.0 - (ImLog(-v_clamped / -v_max_fudged) / ImLog(-v_min_fudged / -v_max_fudged))
        else
            result = ImLog(v_clamped / v_min_fudged) / ImLog(v_max_fudged / v_min_fudged)
        end

        return flipped and (1.0 - result) or result
    else
        -- Linear slider
        return (v_clamped - v_min) / (v_max - v_min)
    end
end

-- Convert a parametric position on a slider into a value v in the output space (the logical opposite of ScaleRatioFromValueT)
--- @param TYPE                     fun(val: number): number
--- @param SIGNEDTYPE               fun(val: number): number
--- @param data_type                ImGuiDataType
--- @param t                        float
--- @param v_min                    number
--- @param v_max                    number
--- @param logarithmic_zero_epsilon float
--- @param zero_deadzone_halfsize   float
function ImGui.ScaleValueFromRatioT(TYPE, SIGNEDTYPE, data_type, t, v_min, v_max, logarithmic_zero_epsilon, zero_deadzone_halfsize)
    -- We special-case the extents because otherwise our logarithmic fudging can lead to "mathematically correct"
    -- but non-intuitive behaviors like a fully-left slider not actually reaching the minimum value. Also generally simpler.
    if t <= 0.0 or v_min == v_max then
        return v_min
    end
    if t >= 1.0 then
        return v_max
    end

    local result = 0
    if logarithmic_zero_epsilon > 0.0 then -- == is_logarithmic from caller
        -- Fudge min/max to avoid getting silly results close to zero
        local v_min_fudged
        if ImAbs(v_min) < logarithmic_zero_epsilon then
            v_min_fudged = (v_min < 0.0) and -logarithmic_zero_epsilon or logarithmic_zero_epsilon
        else
            v_min_fudged = v_min
        end
        local v_max_fudged
        if ImAbs(v_max) < logarithmic_zero_epsilon then
            v_max_fudged = (v_max < 0.0) and -logarithmic_zero_epsilon or logarithmic_zero_epsilon
        else
            v_max_fudged = v_max
        end

        local flipped = v_max < v_min -- Check if range is "backwards"
        if flipped then
            v_min_fudged, v_max_fudged = v_max_fudged, v_min_fudged
        end

        -- Awkward special case - we need ranges of the form (-100 .. 0) to convert to (-100 .. -epsilon), not (-100 .. epsilon)
        if v_max == 0.0 and v_min < 0.0 then
            v_max_fudged = -logarithmic_zero_epsilon
        end

        local t_with_flip = flipped and (1.0 - t) or t -- t, but flipped if necessary to account for us flipping the range

        if v_min * v_max < 0.0 then -- Range crosses zero, so we have to do this in two parts
            local zero_point_center = (-ImMin(v_min, v_max)) / ImAbs(v_max - v_min) -- The zero point in parametric space
            local zero_point_snap_L = zero_point_center - zero_deadzone_halfsize
            local zero_point_snap_R = zero_point_center + zero_deadzone_halfsize

            if t_with_flip >= zero_point_snap_L and t_with_flip <= zero_point_snap_R then
                result = (TYPE)(0.0) -- Special case to make getting exactly zero possible (the epsilon prevents it otherwise)
            elseif t_with_flip < zero_point_center then
                result = (TYPE)(-(logarithmic_zero_epsilon * ImPow(-v_min_fudged / logarithmic_zero_epsilon, 1.0 - (t_with_flip / zero_point_snap_L))))
            else
                result = (TYPE)(logarithmic_zero_epsilon * ImPow(v_max_fudged / logarithmic_zero_epsilon, (t_with_flip - zero_point_snap_R) / (1.0 - zero_point_snap_R)))
            end
        elseif v_min < 0.0 or v_max < 0.0 then  -- Entirely negative slider
            result = (TYPE)(-(-v_max_fudged * ImPow(-v_min_fudged / -v_max_fudged, 1.0 - t_with_flip)))
        else
            result = (TYPE)(v_min_fudged * ImPow(v_max_fudged / v_min_fudged, t_with_flip))
        end
    else
        -- Linear slider
        local is_floating_point = (data_type == ImGuiDataType.Float) or (data_type == ImGuiDataType.Double)
        if is_floating_point then
            result = ImLerp(v_min, v_max, t)
        elseif t < 1.0 then -- t is already < 1.0 here
            -- - For integer values we want the clicking position to match the grab box so we round above
            --   This code is carefully tuned to work with large values (e.g. high ranges of U64) while preserving this property..
            -- - Not doing a *1.0 multiply at the end of a range as it tends to be lossy. While absolute aiming at a large s64/u64
            --   range is going to be imprecise anyway, with this check we at least make the edge values matches expected limits.
            local v_new_off_f = (SIGNEDTYPE)((v_max - v_min)) * t
            result = (TYPE)((SIGNEDTYPE)(v_min) + (SIGNEDTYPE)(v_new_off_f + 0)) -- LUA: + 0 instead of + ((v_min > v_max) and -0.5 or 0.5)
        end
    end

    return result
end

-- FIXME: Try to move more of the code into shared SliderBehavior()
--- @generic T : number
--- @param TYPE        fun(val: number): T
--- @param SIGNEDTYPE  fun(val: number): T
--- @param bb          ImRect
--- @param id          ImGuiID
--- @param data_type   ImGuiDataType
--- @param v           T
--- @param v_min       T
--- @param v_max       T
--- @param format      string
--- @param flags       ImGuiSliderFlags
--- @param out_grab_bb ImRect
--- @return T    v             # updated `v` passed in
--- @return bool value_changed
function ImGui.SliderBehaviorT(TYPE, SIGNEDTYPE, bb, id, data_type, v, v_min, v_max, format, flags, out_grab_bb)
    local g = GImGui
    local style = g.Style

    local axis = (bit32.band(flags, ImGuiSliderFlags.Vertical) ~= 0) and ImGuiAxis.Y or ImGuiAxis.X
    local axis_k = (axis == ImGuiAxis.X) and "x" or "y" -- [Luau] named key: ImVec2[axis] goes through IM_VEC2.__index
    local is_logarithmic = bit32.band(flags, ImGuiSliderFlags.Logarithmic) ~= 0
    local is_floating_point = (data_type == ImGuiDataType.Float) or (data_type == ImGuiDataType.Double)
    local v_range_f = (v_min < v_max) and (v_max - v_min) or (v_min - v_max) -- We don't need high precision for what we do with it.

    -- Calculate bounds
    local grab_padding = 2.0 -- FIXME: Should be part of style.
    local slider_sz = (bb.Max[axis_k] - bb.Min[axis_k]) - grab_padding * 2.0
    local grab_sz = style.GrabMinSize
    if not is_floating_point and v_range_f >= 0.0 then -- v_range_f < 0 may happen on integer overflows
        grab_sz = ImMax(slider_sz / (v_range_f + 1), style.GrabMinSize) -- For integer sliders: if possible have the grab size represent 1 unit
    end
    grab_sz = ImMin(grab_sz, slider_sz)
    local slider_usable_sz = slider_sz - grab_sz
    local slider_usable_pos_min = bb.Min[axis_k] + grab_padding + grab_sz * 0.5
    local slider_usable_pos_max = bb.Max[axis_k] - grab_padding - grab_sz * 0.5

    local logarithmic_zero_epsilon = 0.0 -- Only valid when is_logarithmic is true
    local zero_deadzone_halfsize = 0.0 -- Only valid when is_logarithmic is true
    if is_logarithmic then
        -- When using logarithmic sliders, we need to clamp to avoid hitting zero, but our choice of clamp value greatly affects slider precision. We attempt to use the specified precision to estimate a good lower bound.
        local decimal_precision = is_floating_point and ImParseFormatPrecision(format, 3) or 1
        logarithmic_zero_epsilon = ImPow(0.1, decimal_precision)
        zero_deadzone_halfsize = (style.LogSliderDeadzone * 0.5) / ImMax(slider_usable_sz, 1.0)
    end

    -- Process interacting with the slider
    local value_changed = false
    if g.ActiveId == id then
        local set_new_value = false
        local clicked_t = 0.0
        if g.ActiveIdSource == ImGuiInputSource.Mouse then
            if not g.IO.MouseDown[0] then
                ImGui.ClearActiveID()
            else
                local mouse_abs_pos = g.IO.MousePos[axis_k]
                if g.ActiveIdIsJustActivated then
                    local grab_t = ImGui.ScaleRatioFromValueT(data_type, v, v_min, v_max, logarithmic_zero_epsilon, zero_deadzone_halfsize)
                    if axis == ImGuiAxis.Y then
                        grab_t = 1.0 - grab_t
                    end
                    local grab_pos = ImLerp(slider_usable_pos_min, slider_usable_pos_max, grab_t)
                    local clicked_around_grab = (mouse_abs_pos >= grab_pos - grab_sz * 0.5 - 1.0) and (mouse_abs_pos <= grab_pos + grab_sz * 0.5 + 1.0) -- No harm being extra generous here.
                    g.SliderGrabClickOffset = (clicked_around_grab and is_floating_point) and (mouse_abs_pos - grab_pos) or 0.0
                end
                if slider_usable_sz > 0.0 then
                    clicked_t = ImSaturate((mouse_abs_pos - g.SliderGrabClickOffset - slider_usable_pos_min) / slider_usable_sz)
                end
                if axis == ImGuiAxis.Y then
                    clicked_t = 1.0 - clicked_t
                end
                set_new_value = true
            end
        elseif g.ActiveIdSource == ImGuiInputSource.Keyboard or g.ActiveIdSource == ImGuiInputSource.Gamepad then
            if g.ActiveIdIsJustActivated then
                g.SliderCurrentAccum = 0.0 -- Reset any stored nav delta upon activation
                g.SliderCurrentAccumDirty = false
            end

            local input_delta = (axis == ImGuiAxis.X) and ImGui.GetNavTweakPressedAmount(axis) or -ImGui.GetNavTweakPressedAmount(axis)
            if input_delta ~= 0.0 then
                local tweak_slow = ImGui.IsKeyDown((g.NavInputSource == ImGuiInputSource.Gamepad) and ImGuiKey.NavGamepadTweakSlow or ImGuiKey.NavKeyboardTweakSlow)
                local tweak_fast = ImGui.IsKeyDown((g.NavInputSource == ImGuiInputSource.Gamepad) and ImGuiKey.NavGamepadTweakFast or ImGuiKey.NavKeyboardTweakFast)
                local decimal_precision = is_floating_point and ImParseFormatPrecision(format, 3) or 0
                if decimal_precision > 0 then
                    input_delta = input_delta / 100.0 -- Keyboard/Gamepad tweak speeds in % of slider bounds
                    if tweak_slow then
                        input_delta = input_delta / 10.0
                    end
                else
                    if (v_range_f >= -100.0 and v_range_f <= 100.0 and v_range_f ~= 0.0) or tweak_slow then
                        input_delta = ((input_delta < 0.0) and -1.0 or 1.0) / v_range_f -- Keyboard/Gamepad tweak speeds in integer steps
                    else
                        input_delta = input_delta / 100.0
                    end
                end
                if tweak_fast then
                    input_delta = input_delta * 10.0
                end

                g.SliderCurrentAccum = g.SliderCurrentAccum + input_delta
                g.SliderCurrentAccumDirty = true
            end

            local delta = g.SliderCurrentAccum
            if g.NavActivatePressedId == id and not g.ActiveIdIsJustActivated then
                ImGui.ClearActiveID()
            elseif g.SliderCurrentAccumDirty then
                clicked_t = ImGui.ScaleRatioFromValueT(data_type, v, v_min, v_max, logarithmic_zero_epsilon, zero_deadzone_halfsize)

                if (clicked_t >= 1.0 and delta > 0.0) or (clicked_t <= 0.0 and delta < 0.0) then -- This is to avoid applying the saturation when already past the limits
                    set_new_value = false
                    g.SliderCurrentAccum = 0.0 -- If pushing up against the limits, don't continue to accumulate
                else
                    set_new_value = true
                    local old_clicked_t = clicked_t
                    clicked_t = ImSaturate(clicked_t + delta)

                    -- Calculate what our "new" clicked_t will be, and thus how far we actually moved the slider, and subtract this from the accumulator
                    local v_new = ImGui.ScaleValueFromRatioT(TYPE, SIGNEDTYPE, data_type, clicked_t, v_min, v_max, logarithmic_zero_epsilon, zero_deadzone_halfsize)
                    if is_floating_point and bit32.band(flags, ImGuiSliderFlags.NoRoundToFormat) == 0 then
                        v_new = ImGui.RoundScalarWithFormatT(format, data_type, v_new)
                    end
                    local new_clicked_t = ImGui.ScaleRatioFromValueT(data_type, v_new, v_min, v_max, logarithmic_zero_epsilon, zero_deadzone_halfsize)

                    if delta > 0 then
                        g.SliderCurrentAccum = g.SliderCurrentAccum - ImMin(new_clicked_t - old_clicked_t, delta)
                    else
                        g.SliderCurrentAccum = g.SliderCurrentAccum - ImMax(new_clicked_t - old_clicked_t, delta)
                    end
                end

                g.SliderCurrentAccumDirty = false
            end
        end

        if set_new_value then
            if (bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.ReadOnly) ~= 0) or (bit32.band(flags, ImGuiSliderFlags.ReadOnly) ~= 0) then
                set_new_value = false
            end
        end

        if set_new_value then
            local v_new = ImGui.ScaleValueFromRatioT(TYPE, SIGNEDTYPE, data_type, clicked_t, v_min, v_max, logarithmic_zero_epsilon, zero_deadzone_halfsize)

            -- Round to user desired precision based on format string
            if is_floating_point and bit32.band(flags, ImGuiSliderFlags.NoRoundToFormat) == 0 then
                v_new = ImGui.RoundScalarWithFormatT(format, data_type, v_new)
            end

            -- Apply result
            if v ~= v_new then
                v = v_new
                value_changed = true
            end
        end
    end

    -- [Luau] write out_grab_bb fields directly, no temporary ImRect
    local og_min, og_max = out_grab_bb.Min, out_grab_bb.Max
    if slider_sz < 1.0 then
        og_min.x = bb.Min.x; og_min.y = bb.Min.y; og_max.x = bb.Min.x; og_max.y = bb.Min.y
    else
        -- Output grab position so it can be displayed by the caller
        local grab_t = ImGui.ScaleRatioFromValueT(data_type, v, v_min, v_max, logarithmic_zero_epsilon, zero_deadzone_halfsize)
        if axis == ImGuiAxis.Y then
            grab_t = 1.0 - grab_t
        end
        local grab_pos = ImLerp(slider_usable_pos_min, slider_usable_pos_max, grab_t)
        if axis == ImGuiAxis.X then
            og_min.x = grab_pos - grab_sz * 0.5; og_min.y = bb.Min.y + grab_padding; og_max.x = grab_pos + grab_sz * 0.5; og_max.y = bb.Max.y - grab_padding
        else
            og_min.x = bb.Min.x + grab_padding; og_min.y = grab_pos - grab_sz * 0.5; og_max.x = bb.Max.x - grab_padding; og_max.y = grab_pos + grab_sz * 0.5
        end
    end

    return v, value_changed
end

-- For 32-bit and larger types, slider bounds are limited to half the natural type range.
-- So e.g. an integer Slider between INT_MAX-10 and INT_MAX will fail, but an integer Slider between INT_MAX/2-10 and INT_MAX/2 will be ok.
-- It would be possible to lift that limitation with some work but it doesn't seem to be worth it for sliders.
--- @generic T : number
--- @param bb          ImRect
--- @param id          ImGuiID
--- @param data_type   ImGuiDataType
--- @param v           T
--- @param min         T
--- @param max         T
--- @param format      string
--- @param flags       ImGuiSliderFlags
--- @param out_grab_bb ImRect
--- @return T    v
--- @return bool value_changed
function ImGui.SliderBehavior(bb, id, data_type, v, min, max, format, flags, out_grab_bb)
    -- Read imgui.cpp "API BREAKING CHANGES" section for 1.78 if you hit this assert.
    IM_ASSERT((flags == 1 or bit32.band(flags, ImGuiSliderFlags.InvalidMask_) == 0), "Invalid ImGuiSliderFlags flags! Has the legacy 'float power' argument been mistakenly cast to flags? Call function with ImGuiSliderFlags_Logarithmic flags instead.")
    IM_ASSERT(bit32.band(flags, ImGuiSliderFlags.WrapAround) == 0) -- Not supported by SliderXXX(), only by DragXXX()

    if     data_type == ImGuiDataType.S8 then
        local v32 = (ImS32)((ImS8)(v)); local r
        v32, r = ImGui.SliderBehaviorT(ImS32, ImS32, bb, id, ImGuiDataType.S32, v32, min, max, format, flags, out_grab_bb)
        if r then v = (ImS8)(v32) end
        return v, r
    elseif data_type == ImGuiDataType.U8 then
        local v32 = (ImU32)((ImU8)(v)); local r
        v32, r = ImGui.SliderBehaviorT(ImU32, ImS32, bb, id, ImGuiDataType.U32, v32, min, max, format, flags, out_grab_bb)
        if r then v = (ImU8)(v32) end
        return v, r
    elseif data_type == ImGuiDataType.S16 then
        local v32 = (ImS32)((ImS16)(v)); local r
        v32, r = ImGui.SliderBehaviorT(ImS32, ImS32, bb, id, ImGuiDataType.S32, v32, min, max, format, flags, out_grab_bb)
        if r then v = (ImS16)(v32) end
        return v, r
    elseif data_type == ImGuiDataType.U16 then
        local v32 = (ImU32)((ImU16)(v)); local r
        v32, r = ImGui.SliderBehaviorT(ImU32, ImS32, bb, id, ImGuiDataType.U32, v32, min, max, format, flags, out_grab_bb)
        if r then v = (ImU16)(v32) end
        return v, r
    elseif data_type == ImGuiDataType.S32 then
        IM_ASSERT(min >= math.floor(IM_S32_MIN / 2) and max <= math.floor(IM_S32_MAX / 2))
        return ImGui.SliderBehaviorT(ImS32, ImS32, bb, id, data_type, v, min, max, format, flags, out_grab_bb)
    elseif data_type == ImGuiDataType.U32 then
        IM_ASSERT(max <= math.floor(IM_U32_MAX / 2))
        return ImGui.SliderBehaviorT(ImU32, ImS32, bb, id, data_type, v, min, max, format, flags, out_grab_bb)
    elseif data_type == ImGuiDataType.Float then
        IM_ASSERT(min >= -FLT_MAX / 2.0 and max <= FLT_MAX / 2.0)
        return ImGui.SliderBehaviorT(float, float, bb, id, data_type, v, min, max, format, flags, out_grab_bb)
    elseif data_type == ImGuiDataType.Double then
        IM_ASSERT(min >= -DBL_MAX / 2.0 and max <= DBL_MAX / 2.0)
        return ImGui.SliderBehaviorT(double, double, bb, id, data_type, v, min, max, format, flags, out_grab_bb)
    end

    IM_ASSERT(false)
    return v, false
end

-- Note: data is passed by value and the new value is returned: Returns (data, value_changed). For a slider, min and max are required.
-- Read code of e.g. SliderFloat(), SliderInt() etc. or examples in 'Demo->Widgets->Data Types' to understand how to use this function directly.
--- @generic T : number
--- @param label     string
--- @param data_type ImGuiDataType
--- @param data      T
--- @param min       T
--- @param max       T
--- @param format?   string
--- @param flags?    ImGuiSliderFlags
function ImGui.SliderScalar(label, data_type, data, min, max, format, flags)
    if flags == nil then flags = 0 end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return data, false
    end

    local g = GImGui
    local style = g.Style
    local id = window:GetID(label)
    local w = ImGui.CalcItemWidth()
    local color_marker = (bit32.band(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasColorMarker) ~= 0) and g.NextItemData.ColorMarker or 0

    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)
    local cursor = window.DC.CursorPos
    local frame_bb = ImRect(cursor.x, cursor.y, cursor.x + w, cursor.y + (label_size.y + style.FramePadding.y * 2.0)) -- [Luau] no temporary ImVec2
    local total_bb_x = frame_bb.Max.x + ((label_size.x > 0.0) and (style.ItemInnerSpacing.x + label_size.x) or 0.0)
    local total_bb = SliderScalar_total_bb -- [Luau] scratch: ItemSize()/ItemAdd() only read it
    total_bb.Min.x = frame_bb.Min.x; total_bb.Min.y = frame_bb.Min.y; total_bb.Max.x = total_bb_x; total_bb.Max.y = frame_bb.Max.y

    local temp_input_allowed = bit32.band(flags, ImGuiSliderFlags.NoInput) == 0
    ImGui.ItemSize(total_bb, style.FramePadding.y)
    local item_flags = temp_input_allowed and ImGuiItemFlags.Inputable or 0
    if not ImGui.ItemAdd(total_bb, id, frame_bb, item_flags) then
        return data, false
    end

    -- Default format string when passing NULL
    if format == nil then
        format = ImGui.DataTypeGetInfo(data_type).PrintFmt
    end

    local hovered = ImGui.ItemHoverable(frame_bb, id, g.LastItemData.ItemFlags)
    local temp_input_is_active = temp_input_allowed and ImGui.TempInputIsActive(id)
    if not temp_input_is_active then
        -- Tabbing or Ctrl+Click on Slider turns it into an input box
        local clicked = hovered and ImGui.IsMouseClickedEx(0, ImGuiInputFlags.None, id)
        local make_active = clicked or g.NavActivateId == id
        if make_active and clicked then
            ImGui.SetKeyOwner(ImGuiKey.MouseLeft, id)
        end
        if make_active and temp_input_allowed then
            if (clicked and g.IO.KeyCtrl) or (g.NavActivateId == id and bit32.band(g.NavActivateFlags, ImGuiActivateFlags.PreferInput) ~= 0) then
                temp_input_is_active = true
            end
        end

        -- Store initial value (not used by main lib but available as a convenience but some mods e.g. to revert)
        if make_active then
            g.ActiveIdValueOnActivation = data
        end

        if make_active and not temp_input_is_active then
            ImGui.SetActiveID(id, window)
            ImGui.SetFocusID(id, window)
            ImGui.FocusWindow(window)
            g.ActiveIdUsingNavDirMask = bit32.bor(g.ActiveIdUsingNavDirMask, bit32.lshift(1, ImGuiDir.Left), bit32.lshift(1, ImGuiDir.Right))
        end
    end

    if temp_input_is_active then
        -- Only clamp Ctrl+Click input when ImGuiSliderFlags.ClampOnInput is set (generally via ImGuiSliderFlags.AlwaysClamp)
        local clamp_enabled = bit32.band(flags, ImGuiSliderFlags.ClampOnInput) ~= 0 -- Don't use TempInputIsClampEnabled()
        return ImGui.TempInputScalar(frame_bb, id, label, data_type, data, format, clamp_enabled and min or nil, clamp_enabled and max or nil)
    end

    -- Draw frame
    local frame_col = ImGui.GetColorU32((g.ActiveId == id) and ImGuiCol.FrameBgActive or (hovered and ImGuiCol.FrameBgHovered or ImGuiCol.FrameBg))
    ImGui.RenderNavCursor(frame_bb, id)
    ImGui.RenderFrame(frame_bb.Min, frame_bb.Max, frame_col, false, style.FrameRounding)
    if color_marker ~= 0 and style.ColorMarkerSize > 0.0 then
        ImGui.RenderColorComponentMarker(frame_bb, ImGui.GetColorU32(color_marker, nil, true), style.FrameRounding)
    end
    ImGui.RenderFrameBorder(frame_bb.Min, frame_bb.Max, g.Style.FrameRounding)

    -- Slider behavior
    local grab_bb = SliderScalar_grab_bb -- [Luau] scratch: fully written by SliderBehavior(), only read below
    local value_changed
    data, value_changed = ImGui.SliderBehavior(frame_bb, id, data_type, data, min, max, format, flags, grab_bb)
    if value_changed then
        ImGui.MarkItemEdited(id)
    end

    -- Render grab
    if grab_bb.Max.x > grab_bb.Min.x then
        window.DrawList:AddRectFilled(grab_bb.Min, grab_bb.Max, ImGui.GetColorU32((g.ActiveId == id) and ImGuiCol.SliderGrabActive or ImGuiCol.SliderGrab), style.GrabRounding)
    end

    -- TODO: ImGui.DataTypeFormatString() should be used here instead of ImFormatString()

    -- Display value using user-provided display format so user can add prefix/suffix/decorations to the value.
    -- if g.LogEnabled then
    --     ImGui.LogSetNextTextDecoration("{", "}")
    -- end
    ImGui.RenderTextClipped(frame_bb.Min, frame_bb.Max, FormatCached(format, data), nil, nil, DRAG_TEXT_ALIGN)

    if label_size.x > 0.0 then
        ImGui.RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y), label, 1, label_end, false)
    end

    -- IMGUI_TEST_ENGINE_ITEM_INFO()
    return data, value_changed
end

-- Add multiple sliders on 1 line for compact edition of multiple components
--- @param label      string
--- @param data_type  ImGuiDataType
--- @param v          table
--- @param components int
--- @param v_min      number
--- @param v_max      number
--- @param format?    string
--- @param flags?     ImGuiSliderFlags
function ImGui.SliderScalarN(label, data_type, v, components, v_min, v_max, format, flags)
    if flags == nil then flags = 0 end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local value_changed = false
    ImGui.BeginGroup()
    ImGui.PushID(label)
    ImGui.PushMultiItemsWidths(components, ImGui.CalcItemWidth())

    for i = 1, components do
        ImGui.PushID(i - 1)
        if i > 1 then
            ImGui.SameLine(0, g.Style.ItemInnerSpacing.x)
        end
        if bit32.band(flags, ImGuiSliderFlags.ColorMarkers) ~= 0 then
            ImGui.SetNextItemColorMarker(GDefaultRgbaColorMarkers[i])
        end
        local changed
        v[i], changed = ImGui.SliderScalar("", data_type, v[i], v_min, v_max, format, flags)
        value_changed = value_changed or changed
        ImGui.PopID()
        ImGui.PopItemWidth()
    end
    ImGui.PopID()

    local label_end = ImGui.FindRenderedTextEnd(label)
    if label_end > 1 then
        ImGui.SameLine(0, g.Style.ItemInnerSpacing.x)
        ImGui.TextEx(label, label_end)
    end

    ImGui.EndGroup()
    return value_changed
end

--- @param label   string
--- @param v       [float, float]
--- @param v_min   float
--- @param v_max   float
--- @param format? string
--- @param flags?  ImGuiSliderFlags
function ImGui.SliderFloat2(label, v, v_min, v_max, format, flags)
    return ImGui.SliderScalarN(label, ImGuiDataType.Float, v, 2, v_min, v_max, format, flags)
end

--- @param label   string
--- @param v       [float, float, float]
--- @param v_min   float
--- @param v_max   float
--- @param format? string
--- @param flags?  ImGuiSliderFlags
function ImGui.SliderFloat3(label, v, v_min, v_max, format, flags)
    return ImGui.SliderScalarN(label, ImGuiDataType.Float, v, 3, v_min, v_max, format, flags)
end

--- @param label   string
--- @param v       [float, float, float, float]
--- @param v_min   float
--- @param v_max   float
--- @param format? string
--- @param flags?  ImGuiSliderFlags
function ImGui.SliderFloat4(label, v, v_min, v_max, format, flags)
    return ImGui.SliderScalarN(label, ImGuiDataType.Float, v, 4, v_min, v_max, format, flags)
end

--- @param label   string
--- @param v       float
--- @param v_min   float
--- @param v_max   float
--- @param format? string
--- @param flags?  ImGuiSliderFlags
function ImGui.SliderFloat(label, v, v_min, v_max, format, flags)
    if format == nil then format = "%.3f" end
    if flags  == nil then flags  = 0      end

    return ImGui.SliderScalar(label, ImGuiDataType.Float, v, v_min, v_max, format, flags)
end

--- @param label          string
--- @param v_rad          float
--- @param v_degrees_min? float
--- @param v_degrees_max? float
--- @param format?        string
--- @param flags?         ImGuiSliderFlags
--- @return float v_rad         # updated `v_rad`
--- @return bool  value_changed
function ImGui.SliderAngle(label, v_rad, v_degrees_min, v_degrees_max, format, flags)
    if v_degrees_min == nil then v_degrees_min = -360.0     end
    if v_degrees_max == nil then v_degrees_max =  360.0     end
    if format        == nil then format        = "%.0f deg" end
    if flags         == nil then flags         = 0          end

    local v_deg = v_rad * 360.0 / (2 * IM_PI)
    local value_changed
    v_deg, value_changed = ImGui.SliderFloat(label, v_deg, v_degrees_min, v_degrees_max, format, flags)
    if value_changed then
        v_rad = v_deg * (2 * IM_PI) / 360.0
    end
    return v_rad, value_changed
end

--- @param label   string
--- @param v       int
--- @param v_min   int
--- @param v_max   int
--- @param format? string
--- @param flags?  ImGuiSliderFlags
function ImGui.SliderInt(label, v, v_min, v_max, format, flags)
    if format == nil then format = "%d" end
    if flags  == nil then flags  = 0    end

    return ImGui.SliderScalar(label, ImGuiDataType.S32, v, v_min, v_max, format, flags)
end

function ImGui.SliderInt2(label, v, v_min, v_max, format, flags)
    return ImGui.SliderScalarN(label, ImGuiDataType.S32, v, 2, v_min, v_max, format or "%d", flags)
end

function ImGui.SliderInt3(label, v, v_min, v_max, format, flags)
    return ImGui.SliderScalarN(label, ImGuiDataType.S32, v, 3, v_min, v_max, format or "%d", flags)
end

function ImGui.SliderInt4(label, v, v_min, v_max, format, flags)
    return ImGui.SliderScalarN(label, ImGuiDataType.S32, v, 4, v_min, v_max, format or "%d", flags)
end

--- @param label     string
--- @param size      ImVec2
--- @param data_type ImGuiDataType
--- @param data      number
--- @param min       number
--- @param max       number
--- @param format?   string
--- @param flags?    ImGuiSliderFlags
function ImGui.VSliderScalar(label, size, data_type, data, min, max, format, flags)
    if flags == nil then flags = 0 end
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return data, false
    end

    local g = GImGui
    local style = g.Style
    local id = window:GetID(label)

    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)
    local frame_bb = ImRect(window.DC.CursorPos, window.DC.CursorPos + size)
    local bb = ImRect(frame_bb.Min, ImVec2(frame_bb.Max.x + (label_size.x > 0.0 and (style.ItemInnerSpacing.x + label_size.x) or 0.0), frame_bb.Max.y))

    ImGui.ItemSize(bb, style.FramePadding.y)
    if not ImGui.ItemAdd(frame_bb, id) then
        return data, false
    end

    -- Default format string when passing NULL
    if format == nil then
        format = ImGui.DataTypeGetInfo(data_type).PrintFmt
    end

    local hovered = ImGui.ItemHoverable(frame_bb, id, g.LastItemData.ItemFlags)
    local clicked = hovered and ImGui.IsMouseClickedEx(0, ImGuiInputFlags.None, id)
    if clicked or g.NavActivateId == id then
        if clicked then
            ImGui.SetKeyOwner(ImGuiKey.MouseLeft, id)
        end
        ImGui.SetActiveID(id, window)
        ImGui.SetFocusID(id, window)
        ImGui.FocusWindow(window)
        g.ActiveIdUsingNavDirMask = bit32.bor(g.ActiveIdUsingNavDirMask, bit32.lshift(1, ImGuiDir.Up), bit32.lshift(1, ImGuiDir.Down))
    end

    -- Draw frame
    local frame_col = ImGui.GetColorU32((g.ActiveId == id) and ImGuiCol.FrameBgActive or (hovered and ImGuiCol.FrameBgHovered or ImGuiCol.FrameBg))
    ImGui.RenderNavCursor(frame_bb, id)
    ImGui.RenderFrame(frame_bb.Min, frame_bb.Max, frame_col, true, g.Style.FrameRounding)

    -- Slider behavior
    local grab_bb = ImRect()
    local value_changed
    data, value_changed = ImGui.SliderBehavior(frame_bb, id, data_type, data, min, max, format, bit32.bor(flags or 0, ImGuiSliderFlags.Vertical), grab_bb)
    if value_changed then
        ImGui.MarkItemEdited(id)
    end

    -- Render grab
    if grab_bb.Max.y > grab_bb.Min.y then
        window.DrawList:AddRectFilled(grab_bb.Min, grab_bb.Max, ImGui.GetColorU32((g.ActiveId == id) and ImGuiCol.SliderGrabActive or ImGuiCol.SliderGrab), style.GrabRounding)
    end

    -- Display value using user-provided display format so user can add prefix/suffix/decorations to the value.
    -- For the vertical slider we allow centered text to overlap the frame padding
    -- local value_buf, value_buf_size = {}, 64
    -- TODO: ImGui.DataTypeFormatString()
    ImGui.RenderTextClipped(ImVec2(frame_bb.Min.x, frame_bb.Min.y + style.FramePadding.y), frame_bb.Max, ImFormatString(format, data), nil, nil, ImVec2(0.5, 0.0))
    if label_size.x > 0.0 then
        ImGui.RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y), label, 1, label_end, false)
    end

    -- IMGUI_TEST_ENGINE_ITEM_INFO()
    return data, value_changed
end

--- @param label   string
--- @param size    ImVec2
--- @param v       float
--- @param v_min   float
--- @param v_max   float
--- @param format? string
--- @param flags?  ImGuiSliderFlags
function ImGui.VSliderFloat(label, size, v, v_min, v_max, format, flags)
    if format == nil then format = "%.3f" end

    return ImGui.VSliderScalar(label, size, ImGuiDataType.Float, v, v_min, v_max, format, flags)
end

--- @param label   string
--- @param size    ImVec2
--- @param v       int
--- @param v_min   int
--- @param v_max   int
--- @param format? string
--- @param flags?  ImGuiSliderFlags
function ImGui.VSliderInt(label, size, v, v_min, v_max, format, flags)
    if format == nil then format = "%d" end

    return ImGui.VSliderScalar(label, size, ImGuiDataType.S32, v, v_min, v_max, format, flags)
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: InputText, InputTextMultiline, InputTextWithHint
-------------------------------------------------------------------------------
-- - imstb_textedit.h include
-- - InputText()
-- - InputTextWithHint()
-- - InputTextMultiline()
-- - InputTextEx() [Internal]
-- - DebugNodeInputTextState() [Internal]
-------------------------------------------------------------------------------

--- @param label     string
--- @param buf       char[]
--- @param buf_size  int
--- @param flags?    ImGuiInputTextFlags
--- @param callback? ImGuiInputTextCallback
--- @param user_data any
function ImGui.InputText(label, buf, buf_size, flags, callback, user_data)
    if flags == nil then flags = 0 end

    IM_ASSERT(bit32.band(flags, ImGuiInputTextFlags.Multiline) == 0) -- call InputTextMultiline()
    return ImGui.InputTextEx(label, nil, buf, buf_size, ImVec2(0, 0), flags, callback, user_data)
end

-- [Luau] InputText edits a byte table in place (C++ char buf[N]). Helpers to make/read one:
--   local buf = ImGui.NewTextBuffer("Hello", 256); ImGui.InputText("label", buf, 256); print(ImGui.TextBufferToString(buf))
function ImGui.NewTextBuffer(str, size)
    local t = {}
    for i = 1, #str do t[i] = string.byte(str, i) end
    for i = #str + 1, math.max(size or 0, #str + 1) do t[i] = 0 end
    return t
end
function ImGui.TextBufferToString(buf)
    local n = 0
    while buf[n + 1] ~= nil and buf[n + 1] ~= 0 do n = n + 1 end
    return n == 0 and "" or ImGui._ByteArrayToString(buf, 1, n + 1)
end

--- @param size? ImVec2
function ImGui.InputTextMultiline(label, buf, buf_size, size, flags, callback, user_data)
    return ImGui.InputTextEx(label, nil, buf, buf_size, size or ImVec2(0, 0), bit32.bor(flags or 0, ImGuiInputTextFlags.Multiline), callback, user_data)
end

ImStb = {}

--- @module "imstb_textedit"
local stbte

local IMSTB_TEXTEDIT_GETWIDTH_NEWLINE = -1.0

ImStb.TEXTEDIT_memmove = ImStd.memmove

--- @param ctx  ImGuiContext
--- @param text             char[]
--- @param text_begin       int
--- @param text_end_display int
--- @param text_end         int
--- @param out_offset?      ImVec2
--- @param flags?           ImDrawTextFlags
local function InputTextCalcTextSize(ctx, text, text_begin, text_end_display, text_end, out_offset, flags)
    if flags == nil then flags = 0 end

    local g = ctx
    local obj = g.InputTextState
    IM_ASSERT(text_end_display >= text_begin and text_end_display <= text_end)
    return ImFontCalcTextSizeEx(g.Font, g.FontSize, FLT_MAX, obj.WrapWidth, text, text_begin, text_end_display, text_end, out_offset, flags)
end

-- Wrapper for stb_textedit.h to edit text (our wrapper is for: statically sized buffer, single-line, wchar characters. InputText converts between UTF-8 and wchar)
-- With our UTF-8 use of stb_textedit:
-- - STB_TEXTEDIT_GETCHAR is nothing more than a a "GETBYTE". It's only used to compare to ascii or to copy blocks of text so we are fine.
-- - One exception is the STB_TEXTEDIT_IS_SPACE feature which would expect a full char in order to handle full-width space such as 0x3000 (see ImCharIsBlankW).
-- - ...but we don't use that feature.
--- @param obj ImGuiInputTextState
--- @return int
function ImStb.TEXTEDIT_STRINGLEN(obj) return obj.TextLen end

--- @param obj ImGuiInputTextState
--- @param idx int                 # 1-based
function ImStb.TEXTEDIT_GETCHAR(obj, idx) IM_ASSERT(idx >= 1 and idx <= obj.TextLen + 1); return obj.TextSrc[idx] end

--- @param obj            ImGuiInputTextState
--- @param line_start_idx int                 # 1-based
--- @param char_idx       int                 # 1-based
--- @return float
function ImStb.TEXTEDIT_GETWIDTH(obj, line_start_idx, char_idx) local _, c = ImStd.ImTextCharFromUtf8(obj.TextSrc, line_start_idx + char_idx - 1, obj.TextLen + 1); if c == 10 then return IMSTB_TEXTEDIT_GETWIDTH_NEWLINE end; local g = obj.Ctx; return g.FontBaked:GetCharAdvance(c) * g.FontBakedScale end

--- @param r              StbTexteditRow
--- @param obj            ImGuiInputTextState
--- @param line_start_idx int                 # 1-based
function ImStb.TEXTEDIT_LAYOUTROW(r, obj, line_start_idx)
    local text = obj.TextSrc
    local size, text_remaining = InputTextCalcTextSize(obj.Ctx, text, line_start_idx, obj.TextLen + 1, obj.TextLen + 1, nil, bit32.bor(ImDrawTextFlags.StopOnNewLine, ImDrawTextFlags.WrapKeepBlanks))
    r.x0 = 0.0
    r.x1 = size.x
    r.baseline_y_delta = size.y
    r.ymin = 0.0
    r.ymax = size.y
    r.num_chars = text_remaining - line_start_idx
end

--- @param obj ImGuiInputTextState
--- @param idx int
function ImStb.TEXTEDIT_GETNEXTCHARINDEX(obj, idx)
    if idx >= obj.TextLen then
        return obj.TextLen + 1
    end
    return idx + ImStd.ImTextCharFromUtf8(obj.TextSrc, idx, obj.TextLen + 1)
end

--- @param obj ImGuiInputTextState
--- @param idx int
function ImStb.TEXTEDIT_GETPREVCHARINDEX(obj, idx)
    if idx <= 1 then
        return -1
    end
    local p = ImStd.ImTextFindPreviousUtf8Codepoint(obj.TextSrc, 1, idx)
    return p
end

local ImCharIsSeparatorW do

local separator_list = {
    44, 0x3001, 46, 0x3002, 59, 0xFF1B, 40, 0xFF08, 41, 0xFF09, 123, 0xFF5B, 125, 0xFF5D,
    91, 0x300C, 93, 0x300D, 124, 0xFF5C, 33, 0xFF01, 92, 0xFFE5, 47, 0x30FB, 0xFF0F,
    10, 13
}

--- @param c unsigned_int
function ImCharIsSeparatorW(c)
    for i = 1, #separator_list do
        if c == separator_list[i] then
            return true
        end
    end
    return false
end

end

--- @param obj ImGuiInputTextState
--- @param idx int
function ImStb.is_word_boundary_from_right(obj, idx)
    -- When ImGuiInputTextFlags.Password is set, we don't want actions such as Ctrl+Arrow to leak the fact that underlying data are blanks or separators.
    if bit32.band(obj.Flags, ImGuiInputTextFlags.Password) ~= 0 or idx <= 1 then
        return false
    end

    local prev = ImStd.ImTextFindPreviousUtf8Codepoint(obj.TextSrc, 1, idx)
    local _, curr_c = ImStd.ImTextCharFromUtf8(obj.TextSrc, idx, obj.TextLen + 1)
    local _, prev_c = ImStd.ImTextCharFromUtf8(obj.TextSrc, prev, obj.TextLen + 1)

    local prev_white = ImCharIsBlankW(prev_c)
    local prev_separ = ImCharIsSeparatorW(prev_c)
    local curr_white = ImCharIsBlankW(curr_c)
    local curr_separ = ImCharIsSeparatorW(curr_c)
    return ((prev_white or prev_separ) and not (curr_separ or curr_white)) or (curr_separ and not prev_separ)
end

--- @param obj ImGuiInputTextState
--- @param idx int
function ImStb.is_word_boundary_from_left(obj, idx)
    if bit32.band(obj.Flags, ImGuiInputTextFlags.Password) ~= 0 or idx <= 1 then
        return false
    end

    local prev = ImStd.ImTextFindPreviousUtf8Codepoint(obj.TextSrc, 1, idx)
    local _, prev_c = ImStd.ImTextCharFromUtf8(obj.TextSrc, idx, obj.TextLen + 1)
    local _, curr_c = ImStd.ImTextCharFromUtf8(obj.TextSrc, prev, obj.TextLen + 1)

    local prev_white = ImCharIsBlankW(prev_c)
    local prev_separ = ImCharIsSeparatorW(prev_c)
    local curr_white = ImCharIsBlankW(curr_c)
    local curr_separ = ImCharIsSeparatorW(curr_c)
    return (prev_white and not (curr_separ or curr_white)) or (curr_separ and not prev_separ)
end

--- @param obj ImGuiInputTextState
--- @param idx int
function ImStb.TEXTEDIT_MOVEWORDLEFT(obj, idx)
    idx = ImStb.TEXTEDIT_GETPREVCHARINDEX(obj, idx)
    while idx >= 1 and not ImStb.is_word_boundary_from_right(obj, idx) do
        idx = ImStb.TEXTEDIT_GETPREVCHARINDEX(obj, idx)
    end
    return (idx < 1) and 1 or idx
end

--- @param obj ImGuiInputTextState
--- @param idx int
local function STB_TEXTEDIT_MOVEWORDRIGHT_MAC(obj, idx)
    local len = obj.TextLen
    idx = ImStb.TEXTEDIT_GETNEXTCHARINDEX(obj, idx)
    while idx <= len and not ImStb.is_word_boundary_from_left(obj, idx) do
        idx = ImStb.TEXTEDIT_GETNEXTCHARINDEX(obj, idx)
    end
    return (idx > len + 1) and len + 1 or idx
end

--- @param obj ImGuiInputTextState
--- @param idx int
local function STB_TEXTEDIT_MOVEWORDRIGHT_WIN(obj, idx)
    idx = ImStb.TEXTEDIT_GETNEXTCHARINDEX(obj, idx)
    local len = obj.TextLen
    while idx <= len and not ImStb.is_word_boundary_from_right(obj, idx) do
        idx = ImStb.TEXTEDIT_GETNEXTCHARINDEX(obj, idx)
    end
    return (idx > len + 1) and len + 1 or idx
end

--- @param obj ImGuiInputTextState
--- @param idx int
function ImStb.TEXTEDIT_MOVEWORDRIGHT(obj, idx)
    local g = obj.Ctx
    if g.IO.ConfigMacOSXBehaviors then
        return STB_TEXTEDIT_MOVEWORDRIGHT_MAC(obj, idx)
    else
        return STB_TEXTEDIT_MOVEWORDRIGHT_WIN(obj, idx)
    end
end

-- Reimplementation of stb_textedit_move_line_start()/stb_textedit_move_line_end() which supports word-wrapping.
--- @param obj    ImGuiInputTextState
--- @param state  STB_TexteditState
--- @param cursor int
function ImStb.TEXTEDIT_MOVELINESTART(obj, state, cursor)
    if state.single_line then
        return 1
    end

    if obj.WrapWidth > 0.0 then
        local g = obj.Ctx
        local bol = ImStd.ImStrbol(obj.TextSrc, cursor, 1)
        local p = bol
        local text_end = obj.TextLen + 1 -- End of line would be enough
        while p >= bol do
            local eol = ImFontCalcWordWrapPositionEx(g.Font, g.FontSize, obj.TextSrc, p, text_end, obj.WrapWidth, ImDrawTextFlags.WrapKeepBlanks)
            if p == cursor then -- If we are already on a visible beginning-of-line, return real beginning-of-line (would be same as regular handler below)
                return bol
            end
            if eol == cursor and obj.TextA[cursor] ~= 10 and obj.LastMoveDirectionLR == ImGuiDir.Left then
                return bol
            end
            if eol >= cursor then
                return p
            end
            p = (obj.TextSrc[eol] == 10) and eol + 1 or eol
        end
    end

    -- Regular handler, same as stb_textedit_move_line_start()
    while cursor > 1 do
        local prev_cursor = ImStb.TEXTEDIT_GETPREVCHARINDEX(obj, cursor)
        if (ImStb.TEXTEDIT_GETCHAR(obj, prev_cursor) == STB_TEXTEDIT_NEWLINE) then
            break
        end
        cursor = prev_cursor
    end
    return cursor
end

--- @param obj    ImGuiInputTextState
--- @param state  STB_TexteditState
--- @param cursor int
function ImStb.TEXTEDIT_MOVELINEEND(obj, state, cursor)
    local n = ImStb.TEXTEDIT_STRINGLEN(obj)
    if state.single_line then
        return n + 1
    end

    if obj.WrapWidth > 0.0 then
        local g = obj.Ctx
        local p = ImStd.ImStrbol(obj.TextSrc, cursor, 1)
        local text_end = obj.TextLen + 1 -- End of line would be enough
        while p < text_end do
            local eol = ImFontCalcWordWrapPositionEx(g.Font, g.FontSize, obj.TextSrc, p, text_end, obj.WrapWidth, ImDrawTextFlags.WrapKeepBlanks)
            cursor = eol
            if eol == cursor and obj.LastMoveDirectionLR ~= ImGuiDir.Left then -- If we are already on a visible end-of-line, switch to regular handle
                break
            end
            if eol > cursor then
                return cursor
            end
            p = (obj.TextSrc[eol] == 10) and eol + 1 or eol
        end
    end

    -- Regular handler, same as stb_textedit_move_line_end()
    while (cursor < n and ImStb.TEXTEDIT_GETCHAR(obj, cursor) ~= STB_TEXTEDIT_NEWLINE) do
        cursor = ImStb.TEXTEDIT_GETNEXTCHARINDEX(obj, cursor)
    end
    return cursor
end

--- @param obj ImGuiInputTextState
--- @param pos int
--- @param n   int
function ImStb.TEXTEDIT_DELETECHARS(obj, pos, n)
    -- Offset remaining text (+ copy zero terminator)
    IM_ASSERT(obj.TextSrc == obj.TextA.Data)
    ImStd.memmove(obj.TextA.Data, pos, obj.TextA.Data, pos + n, obj.TextLen - n - pos + 2)
    obj.EditedBefore = true
    obj.EditedThisFrame = true
    obj.TextLen = obj.TextLen - n
end

--- @param obj          ImGuiInputTextState
--- @param pos          int
--- @param new_text     ImStringBuffer
--- @param new_text_pos int
--- @param new_text_len int
function ImStb.TEXTEDIT_INSERTCHARS(obj, pos, new_text, new_text_pos, new_text_len)
    local is_resizable = bit32.band(obj.Flags, ImGuiInputTextFlags.CallbackResize) ~= 0
    local text_len = obj.TextLen
    IM_ASSERT(pos <= text_len + 1)

    -- We support partial insertion (with a mod in stb_textedit.h)
    local avail = obj.BufCapacity - 1 - obj.TextLen
    if not is_resizable and new_text_len > avail then
        new_text_len = math.floor(ImStd.ImTextFindValidUtf8CodepointEnd(new_text, new_text_pos, new_text_len + 1, avail) - new_text_pos) -- Truncate to closest UTF-8 codepoint. Alternative: return 0 to cancel insertion.
    end
    if new_text_len == 0 then
        return 0
    end

    -- Grow internal buffer if needed
    IM_ASSERT(obj.TextSrc == obj.TextA.Data)
    if text_len + new_text_len + 1 > obj.TextA.Size and is_resizable then
        obj.TextA:resize(text_len + ImClamp(new_text_len, 32, ImMax(256, new_text_len)) + 1)
        obj.TextSrc = obj.TextA.Data
    end

    local text = obj.TextA.Data
    if pos ~= text_len + 1 then
        ImStd.memmove(text, pos + new_text_len, text, pos, text_len - pos + 1)
    end
    ImStd.memmove(text, pos, new_text, new_text_pos, new_text_len)

    obj.EditedBefore = true
    obj.EditedThisFrame = true
    obj.TextLen = obj.TextLen + new_text_len
    obj.TextA[obj.TextLen + 1] = 0

    return new_text_len
end

stbte = IM_INCLUDE"imstb_textedit.lua"

-- stb_textedit internally allows for a single undo record to do addition and deletion, but somehow, calling
-- the stb_textedit_paste() function creates two separate records, so we perform it manually. (FIXME: Report to nothings/stb?)
--- @param str      ImGuiInputTextState
--- @param state    STB_TexteditState
--- @param text     IMSTB_TEXTEDIT_CHARTYPE[]
--- @param text_len int
function ImStb.stb_textedit_replace(str, state, text, text_len)
    stbte.makeundo_replace(str, state, 1, str.TextLen, text_len)
    ImStb.TEXTEDIT_DELETECHARS(str, 1, str.TextLen)
    state.cursor = 1
    state.select_start = 1
    state.select_end = 1
    if text_len <= 0 then
        return
    end

    local text_len_inserted = ImStb.TEXTEDIT_INSERTCHARS(str, 1, text, 1, text_len)
    if text_len_inserted > 0 then
        state.cursor = text_len + 1
        state.select_start = text_len + 1
        state.select_end = text_len + 1
        state.has_preferred_x = false

        return
    end

    IM_ASSERT(false) -- Failed to insert character, normally shouldn't happen because of how we currently use stb_textedit_replace()
end

local MT = ImGui.GetMetatables()

do

--- @param key int
function MT.ImGuiInputTextState:OnKeyPressed(key)
    stbte.key(self, self.Stb, key)
    self.CursorFollow = true
    self:CursorAnimReset()
    local key_u = bit32.band(key, bit32.bnot(STB_TEXTEDIT_K_SHIFT))
    if key_u == STB_TEXTEDIT_K_LEFT or key_u == STB_TEXTEDIT_K_LINESTART or key_u == STB_TEXTEDIT_K_TEXTSTART or key_u == STB_TEXTEDIT_K_BACKSPACE or key_u == STB_TEXTEDIT_K_WORDLEFT then
        self.LastMoveDirectionLR = ImGuiDir.Left
    elseif key_u == STB_TEXTEDIT_K_RIGHT or key_u == STB_TEXTEDIT_K_LINEEND or key_u == STB_TEXTEDIT_K_TEXTEND or key_u == STB_TEXTEDIT_K_DELETE or key_u == STB_TEXTEDIT_K_WORDRIGHT then
        self.LastMoveDirectionLR = ImGuiDir.Right
    end
end

local utf8 = {0, 0, 0, 0, 0}

--- @param c unsigned_int
function MT.ImGuiInputTextState:OnCharPressed(c)
    for i = 1, 5 do utf8[i] = 0 end

    -- Convert the key to a UTF8 byte sequence.
    -- The changes we had to make to stb_textedit_key made it very much UTF-8 specific which is not too great.
    ImStd.ImTextCharToUtf8(utf8, c)
    stbte.text(self, self.Stb, utf8, ImStd.ImStrlen(utf8))
    self.CursorFollow = true
    self:CursorAnimReset()
end

-- Those functions are not inlined in imgui_internal.h, allowing us to hide ImStbTexteditState from that header.
function MT.ImGuiInputTextState:CursorAnimReset() self.CursorAnim = -0.30 end -- After a user-input the cursor stays on for a while without blinking

function MT.ImGuiInputTextState:CursorClamp()
    self.Stb.cursor = ImMin(self.Stb.cursor, self.TextLen + 1)
    self.Stb.select_start = ImMin(self.Stb.select_start, self.TextLen + 1)
    self.Stb.select_end = ImMin(self.Stb.select_end, self.TextLen + 1)
end

function MT.ImGuiInputTextState:HasSelection() return self.Stb.select_start ~= self.Stb.select_end end

function MT.ImGuiInputTextState:SelectAll()
    self.Stb.select_start = 1
    self.Stb.cursor = self.TextLen + 1
    self.Stb.select_end = self.TextLen + 1
    self.Stb.has_preferred_x = false
end

end

function ImGui.PushPasswordFont()
    local g = GImGui
    local backup = g.InputTextPasswordFontBackupBaked
    IM_ASSERT(backup.IndexAdvanceX.Size == 0 and backup.IndexLookup.Size == 0)
    local glyph = g.FontBaked:FindGlyph(42) -- '*'
    g.InputTextPasswordFontBackupFlags = g.Font.Flags
    backup.FallbackGlyphIndex = g.FontBaked.FallbackGlyphIndex
    backup.FallbackAdvanceX = g.FontBaked.FallbackAdvanceX
    backup.IndexLookup:swap(g.FontBaked.IndexLookup)
    backup.IndexAdvanceX:swap(g.FontBaked.IndexAdvanceX)
    g.Font.Flags = bit32.bor(g.Font.Flags, ImFontFlags.NoLoadGlyphs)
    g.FontBaked.FallbackGlyphIndex = g.FontBaked.Glyphs:index_from_ptr(glyph) + 1
    g.FontBaked.FallbackAdvanceX = glyph.AdvanceX
end

function ImGui.PopPasswordFont()
    local g = GImGui
    local backup = g.InputTextPasswordFontBackupBaked
    g.Font.Flags = g.InputTextPasswordFontBackupFlags
    g.FontBaked.FallbackGlyphIndex = backup.FallbackGlyphIndex
    g.FontBaked.FallbackAdvanceX = backup.FallbackAdvanceX
    g.FontBaked.IndexLookup:swap(backup.IndexLookup)
    g.FontBaked.IndexAdvanceX:swap(backup.IndexAdvanceX)
    IM_ASSERT(backup.IndexAdvanceX.Size == 0 and backup.IndexLookup.Size == 0)
end

-- Return false to discard a character. Returns (char, ok).
--- @param ctx                        ImGuiContext
--- @param state                      ImGuiInputTextState
--- @param char                       unsigned_int
--- @param callback?                  ImGuiInputTextCallback
--- @param user_data                  any
--- @param input_source_is_clipboard? bool
--- @return unsigned_int out_char
--- @return bool
local function InputTextFilterCharacter(ctx, state, char, callback, user_data, input_source_is_clipboard)
    if input_source_is_clipboard == nil then input_source_is_clipboard = false end

    IM_ASSERT(state ~= nil)

    local c = char
    local flags = state.Flags

    -- Filter non-printable (NB: isprint is unreliable! see #2467)
    local apply_named_filters = true
    if c < 0x20 then
        local pass = false
        pass = pass or (c == 10) and (bit32.band(flags, ImGuiInputTextFlags.Multiline) ~= 0) -- Note that an Enter KEY will emit \r and be ignored (we poll for KEY in InputText() code)
        if c == 10 and input_source_is_clipboard and (bit32.band(flags, ImGuiInputTextFlags.Multiline) == 0) then -- In single line mode, replace \n with a space
            char = 32
            c = 32
            pass = true
        end
        pass = pass or (c == 10) and (bit32.band(flags, ImGuiInputTextFlags.Multiline) ~= 0)
        pass = pass or (c == 9) and (bit32.band(flags, ImGuiInputTextFlags.AllowTabInput) ~= 0) -- tab
        if not pass then
            return char, false
        end
        apply_named_filters = false -- Override named filters below so newline and tabs can still be inserted.
    end

    if not input_source_is_clipboard then
        -- We ignore Ascii representation of delete (emitted from Backspace on OSX, see #2578, #2817)
        if c == 127 then
            return char, false
        end

        -- Filter private Unicode range. GLFW on OSX seems to send private characters for special keys like arrow keys (FIXME)
        if c >= 0xE000 and c <= 0xF8FF then
            return char, false
        end
    end

    -- Filter Unicode ranges we are not handling in this build
    if c > IM_UNICODE_CODEPOINT_MAX then
        return char, false
    end

    -- Generic named filters
    if apply_named_filters and (bit32.band(flags, bit32.bor(ImGuiInputTextFlags.CharsDecimal, ImGuiInputTextFlags.CharsHexadecimal, ImGuiInputTextFlags.CharsUppercase, ImGuiInputTextFlags.CharsNoBlank, ImGuiInputTextFlags.CharsScientific, ImGuiInputTextFlags.LocalizeDecimalPoint))) ~= 0 then
        -- The standard mandate that programs starts in the "C" locale where the decimal point is '.'.
        -- We don't really intend to provide widespread support for it, but out of empathy for people stuck with using odd API, we support the bare minimum aka overriding the decimal point.
        -- Change the default decimal_point with:
        --   ImGui::GetPlatformIO()->Platform_LocaleDecimalPoint = *localeconv()->decimal_point;
        -- Users of non-default decimal point (in particular ',') may be affected by word-selection logic (is_word_boundary_from_right/is_word_boundary_from_left) functions.
        local g = ctx
        local c_decimal_point = g.PlatformIO.Platform_LocaleDecimalPoint
        if bit32.band(flags, bit32.bor(ImGuiInputTextFlags.CharsDecimal, ImGuiInputTextFlags.CharsScientific, ImGuiInputTextFlags.LocalizeDecimalPoint)) ~= 0 then
            if c == 46 or c == 44 then -- '.' or ','
                c = c_decimal_point
            end
        end

        -- Full-width -> half-width conversion for numeric fields: https://en.wikipedia.org/wiki/Halfwidth_and_Fullwidth_Forms_(Unicode_block)
        -- While this is mostly convenient, this has the side-effect for uninformed users accidentally inputting full-width characters that they may
        -- scratch their head as to why it works in numerical fields vs in generic text fields it would require support in the font.
        if bit32.band(flags, bit32.bor(ImGuiInputTextFlags.CharsDecimal, ImGuiInputTextFlags.CharsScientific, ImGuiInputTextFlags.CharsHexadecimal)) ~= 0 then
            if c >= 0xFF01 and c <= 0xFF5E then
                c = c - 0xFF01 + 0x21
            end
        end

        -- Allow 0-9 . - + * /
        if bit32.band(flags, ImGuiInputTextFlags.CharsDecimal) ~= 0 then
            if not (c >= 48 and c <= 57) and (c ~= c_decimal_point) and (c ~= 45) and (c ~= 43) and (c ~= 42) and (c ~= 47) then -- 0-9 . - + * /
                return char, false
            end
        end

        -- Allow 0-9 . - + * / e E
        if bit32.band(flags, ImGuiInputTextFlags.CharsScientific) ~= 0 then
            if not (c >= 48 and c <= 57) and (c ~= c_decimal_point) and (c ~= 45) and (c ~= 43) and (c ~= 42) and (c ~= 47) and (c ~= 101) and (c ~= 69) then -- 0-9 . - + * / e E
                return char, false
            end
        end

        -- Allow 0-9 a-F A-F
        if bit32.band(flags, ImGuiInputTextFlags.CharsHexadecimal) ~= 0 then
            if not (c >= 48 and c <= 57) and not (c >= 97 and c <= 102) and not (c >= 65 and c <= 70) then -- 0-9 a-f A-F
                return char, false
            end
        end

        -- Turn a-z into A-Z
        if bit32.band(flags, ImGuiInputTextFlags.CharsUppercase) ~= 0 then
            if c >= 97 and c <= 122 then -- a-z
                c = c + (65 - 97) -- 'A' - 'a'
            end
        end

        if bit32.band(flags, ImGuiInputTextFlags.CharsNoBlank) ~= 0 then
            if ImStd.ImCharIsBlankW(c) then
                return char, false
            end
        end

        char = c
    end

    -- Custom callback filter
    if bit32.band(flags, ImGuiInputTextFlags.CallbackCharFilter) ~= 0 then
        local g = GImGui
        local callback_data = ImGuiInputTextCallbackData()
        callback_data.Ctx = g
        callback_data.ID = state.ID
        callback_data.Flags = flags
        callback_data.EventFlag = ImGuiInputTextFlags.CallbackCharFilter
        callback_data.EventChar = c
        callback_data.EventActivated = (state ~= nil and g.ActiveId == state.ID and g.ActiveIdIsJustActivated)
        callback_data.CursorPos = state.Stb.cursor
        callback_data.SelectionStart = state.Stb.select_start
        callback_data.SelectionEnd = state.Stb.select_end
        callback_data.UserData = user_data
        if callback(callback_data) ~= 0 then
            return char, false
        end
        char = callback_data.EventChar
        if not callback_data.EventChar then
            return char, false
        end
    end

    return char, true
end

-- Find the shortest single replacement we can make to get from old_buf to new_buf
-- Note that this doesn't directly alter state->TextA, state->TextLen. They are expected to be made valid separately.
-- FIXME: Ideally we should transition toward (1) making InsertChars()/DeleteChars() update undo-stack (2) discourage (and keep reconcile) or obsolete (and remove reconcile) accessing buffer directly.
--- @param state      ImGuiInputTextState
--- @param old_buf    ImStringBuffer
--- @param old_length int
--- @param new_buf    ImStringBuffer
--- @param new_length int
local function InputTextReconcileUndoState(state, old_buf, old_length, new_buf, new_length)
    local shorter_length = ImMin(old_length, new_length)
    local first_diff
    for i = 1, shorter_length do
        first_diff = i
        if old_buf[first_diff] ~= new_buf[first_diff] then
            break
        end
    end
    if first_diff == old_length + 1 and first_diff == new_length + 1 then
        return
    end

    local old_last_diff = old_length
    local new_last_diff = new_length
    while old_last_diff >= first_diff and new_last_diff >= first_diff do
        if old_buf[old_last_diff] ~= new_buf[new_last_diff] then
            break
        end

        old_last_diff = old_last_diff - 1
        new_last_diff = new_last_diff - 1
    end

    local insert_len = new_last_diff - first_diff + 1
    local delete_len = old_last_diff - first_diff + 1
    if insert_len > 0 or delete_len > 0 then
        local undostate = state.Stb.undostate
        local p = stbte.createundo(undostate, first_diff, delete_len, insert_len)
        if p then
            for i = 0, delete_len - 1 do
                undostate.undo_char[p + i] = old_buf[first_diff + i]
            end
        end
    end
end

-- As InputText() retain textual data and we currently provide a path for user to not retain it (via local variables)
-- we need some form of hook to reapply data back to user buffer on deactivation frame. (#4714)
-- It would be more desirable that we discourage users from taking advantage of the "user not retaining data" trick,
-- but that more likely be attractive when we do have _NoLiveEdit flag available.
--- @param id ImGuiID
function ImGui.InputTextDeactivateHook(id)
    local g = GImGui
    local state = g.InputTextState
    if id == 0 or state.ID ~= id or g.ActiveId ~= id then
        return
    end
    if not state.EditedBefore then
        return
    end
    -- IMGUI_DEBUG_LOG_ACTIVEID("InputTextDeactivateHook() id = 0x%08X\n", id);

    g.InputTextDeactivatedState.ID = state.ID
    g.InputTextDeactivatedState.ElapseFrame = g.FrameCount + 1
    if bit32.band(state.Flags, ImGuiInputTextFlags.ReadOnly) ~= 0 then
        g.InputTextDeactivatedState.TextA:resize(0) -- In theory this data won't be used, but clear to be neat.
    else
        IM_ASSERT(state.TextA.Data ~= nil)
        -- IM_ASSERT(state.TextA[state.TextLen + 1] == 0)
        g.InputTextDeactivatedState.TextA:resize(state.TextLen + 1)
        ImStd.memmove(g.InputTextDeactivatedState.TextA.Data, 1, state.TextA.Data, 1, state.TextLen) -- state.TextLen + 1
    end
end

-- FIXME-WORDWRAP: Bundle some of this into ImGuiTextIndex and/or extract as a different tool?
-- 'max_output_buffer_size' happens to be a meaningful optimization to avoid writing the full line_index when not necessarily needed (e.g. very large buffer, scrolled up, inactive)
--- @param flags                  ImGuiInputTextFlags
--- @param line_index             ImGuiTextIndex
--- @param buf                    char[]
--- @param buf_end                int
--- @param wrap_width             float
--- @param max_output_buffer_size int
--- @return int  size
--- @return int? out_buf_end
local function InputTextLineIndexBuild(flags, line_index, buf, buf_end, wrap_width, max_output_buffer_size)
    local g = GImGui
    local size = 0
    local s = 1
    local trailing_line_already_counted = false
    if bit32.band(flags, ImGuiInputTextFlags.WordWrap) ~= 0 then
        while s < buf_end do
            if size <= max_output_buffer_size then
                line_index.Offsets:push_back(s - 1)
            end
            size = size + 1
            s = ImFontCalcWordWrapPositionEx(g.Font, g.FontSize, buf, s, buf_end, wrap_width, ImDrawTextFlags.WrapKeepBlanks)

            if buf[s] == 10 then s = s + 1 end
        end
    elseif buf_end ~= nil then
        while s < buf_end do
            if size <= max_output_buffer_size then
                line_index.Offsets:push_back(s - 1)
            end
            size = size + 1
            s = ImMemchr(buf, 10, s) --[[@as int]] -- FIXME:

            if s then s = s + 1 else s = buf_end end
        end
    else
        -- Inactive path: we don't know buf_end ahead of time.
        local s_eol
        s = 1
        while true do
            if size <= max_output_buffer_size then
                line_index.Offsets:push_back(s - 1)
            end
            size = size + 1

            s_eol = ImMemchr(buf, 10, s)
            if s_eol == nil then
                s = s + ImStd.ImStrlen(buf) - s -- FIXME:
                trailing_line_already_counted = true
                break
            end

            s = s_eol + 1
        end
    end

    local out_buf_end
    if out_buf_end ~= nil then
        out_buf_end = s
        buf_end = s
    end
    if size == 0 then
        line_index.Offsets:push_back(0)
        size = size + 1
    end
    if s > 1 and buf[s - 1] == 10 and not trailing_line_already_counted then
        local old_size = size
        size = size + 1
        if old_size <= max_output_buffer_size then
            line_index.Offsets:push_back(s - 1)
        end
    end
    return size, out_buf_end
end

--- @param t        table
--- @param in_begin int
--- @param in_end   int
--- @param v        int
local function ImLowerBound(t, in_begin, in_end, v)
    local in_p = in_begin
    local count = in_end - in_begin

    local floor = math.floor
    local rshift = bit32.rshift
    while count > 0 do
        local count2 = floor(rshift(count, 1))
        local mid = in_p + count2

        if t[mid] < v then
            in_p = mid + 1
            count = count - count2 - 1
        else
            count = count2
        end
    end

    return in_p
end

--- @param g          ImGuiContext
--- @param state      ImGuiInputTextState
--- @param line_index ImGuiTextIndex
--- @param buf        char[]
--- @param buf_end    int
--- @param cursor_n   int
--- @return ImVec2
local function InputTextLineIndexGetPosOffset(g, state, line_index, buf, buf_end, cursor_n)
    local cursor_ptr = cursor_n

    local it = ImLowerBound(line_index.Offsets, 1, line_index.Offsets.Size + 1, cursor_ptr)

    if it > 1 then
        if it > line_index.Offsets.Size or line_index.Offsets[it] ~= cursor_ptr or (state ~= nil and state.WrapWidth > 0.0 and state.LastMoveDirectionLR == ImGuiDir.Right and
            buf[cursor_ptr - 1] ~= 10 and buf[cursor_ptr - 1] ~= 0) then
            it = it - 1
        end
    end

    local line_no = it
    local line_start = (line_no == 1) and 1 or line_index.Offsets[line_no] + 1

    local offset = ImVec2()
    offset.x = InputTextCalcTextSize(g, buf, line_start, cursor_ptr, buf_end, nil, ImDrawTextFlags.WrapKeepBlanks).x
    offset.y = line_no * g.FontSize

    return offset
end

-- Edit a string of text
-- - buf_size account for the zero-terminator, so a buf_size of 6 can hold "Hello" but not "Hello!".
-- - When active, hold on a privately held copy of the text (and apply back to 'buf'). So changing 'buf' while the InputText is active has no effect.
--- @param label              string
--- @param hint?              char[]
--- @param buf                char[]
--- @param buf_size           int
--- @param size_arg           ImVec2
--- @param flags              ImGuiInputTextFlags
--- @param callback?          ImGuiInputTextCallback
--- @param callback_user_data any
local HintBufCache = setmetatable({}, { __mode = "k" })
local function HintToBuf(hint)
    local t = HintBufCache[hint]
    if t == nil then
        t = {}
        for i = 1, #hint do t[i] = string.byte(hint, i) end
        t[#hint + 1] = 0
        HintBufCache[hint] = t
    end
    return t
end

function ImGui.InputTextEx(label, hint, buf, buf_size, size_arg, flags, callback, callback_user_data)
    if type(hint) == "string" then hint = HintToBuf(hint) end
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    IM_ASSERT(buf ~= nil and buf_size >= 0)
    IM_ASSERT(not (bit32.band(flags, ImGuiInputTextFlags.CallbackHistory) ~= 0 and bit32.band(flags, ImGuiInputTextFlags.Multiline) ~= 0))        -- Can't use both together (they both use up/down keys)
    IM_ASSERT(not (bit32.band(flags, ImGuiInputTextFlags.CallbackCompletion) ~= 0 and bit32.band(flags, ImGuiInputTextFlags.AllowTabInput) ~= 0)) -- Can't use both together (they both use tab key)
    IM_ASSERT(not (bit32.band(flags, ImGuiInputTextFlags.ElideLeft) ~= 0 and bit32.band(flags, ImGuiInputTextFlags.Multiline) ~= 0))              -- Multiline does not work with left-trimming
    IM_ASSERT(bit32.band(flags, ImGuiInputTextFlags.WordWrap) == 0 or bit32.band(flags, ImGuiInputTextFlags.Password) == 0)  -- WordWrap does not work with Password mode.
    IM_ASSERT(bit32.band(flags, ImGuiInputTextFlags.WordWrap) == 0 or bit32.band(flags, ImGuiInputTextFlags.Multiline) ~= 0) -- WordWrap does not work in single-line mode.

    local g = GImGui --[[@as ImGuiContext]]
    local io = g.IO
    local style = g.Style

    local RENDER_SELECTION_WHEN_INACTIVE = false
    local is_multiline = bit32.band(flags, ImGuiInputTextFlags.Multiline) ~= 0

    if is_multiline then -- Open group before calling GetID() because groups tracks id created within their scope (including the scrollbar)
        ImGui.BeginGroup()
    end
    local id = window:GetID(label)
    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)
    local frame_size = ImGui.CalcItemSize(size_arg, ImGui.CalcItemWidth(), (is_multiline and g.FontSize * 8.0 or label_size.y) + style.FramePadding.y * 2.0)  -- Arbitrary default of 8 lines high for multi-line
    local total_size = ImVec2(frame_size.x + ((label_size.x > 0.0) and (style.ItemInnerSpacing.x + label_size.x) or 0.0), frame_size.y)

    local frame_bb = ImRect(window.DC.CursorPos, window.DC.CursorPos + frame_size)
    local total_bb = ImRect(frame_bb.Min, frame_bb.Min + total_size)

    local draw_window = window
    local inner_size = ImVec2()
    ImVec2_Copy(inner_size, frame_size)
    local item_data_backup = ImGuiLastItemData()
    if is_multiline then
        local backup_pos = ImVec2()
        ImVec2_Copy(backup_pos, window.DC.CursorPos)
        ImGui.ItemSize(total_bb, style.FramePadding.y)
        local no_clip = (g.InputTextDeactivatedState.ID == id) or (g.ActiveId == id) or (id == g.NavActivateId) -- Mimic some of ItemAdd() logic + add InputTextDeactivatedState.ID check.
        if not ImGui.ItemAdd(total_bb, id, frame_bb, ImGuiItemFlags.Inputable) and not no_clip then
            ImGui.EndGroup()
            return false
        end
        ImGuiLastItemData_Copy(item_data_backup, g.LastItemData)
        ImVec2_Copy(window.DC.CursorPos, backup_pos)

        -- Prevent NavActivation from explicit Tabbing when our widget accepts Tab inputs: this allows cycling through widgets without stopping.
        if g.NavActivateId == id and (bit32.band(g.NavActivateFlags, ImGuiActivateFlags.FromTabbing) ~= 0) and (bit32.band(g.NavActivateFlags, ImGuiActivateFlags.FromFocusApi) == 0) and (bit32.band(flags, ImGuiInputTextFlags.AllowTabInput) ~= 0) then
            g.NavActivateId = 0
        end

        -- Prevent NavActivate reactivating in BeginChild() when we are already active.
        local backup_activate_id = g.NavActivateId
        if g.ActiveId == id then -- Prevent reactivation
            g.NavActivateId = 0
        end

        -- We reproduce the contents of BeginChildFrame() in order to provide 'label' so our window internal data are easier to read/debug.
        ImGui.PushStyleColor(ImGuiCol.ChildBg, style.Colors[ImGuiCol.FrameBg])
        ImGui.PushStyleVar(ImGuiStyleVar.ChildRounding, style.FrameRounding)
        ImGui.PushStyleVar(ImGuiStyleVar.ChildBorderSize, style.FrameBorderSize)
        ImGui.PushStyleVar(ImGuiStyleVar.WindowPadding, ImVec2(0, 0)) -- Ensure no clip rect so mouse hover can reach FramePadding edges
        local child_visible = ImGui.BeginChildEx(label, id, frame_bb:GetSize(), ImGuiChildFlags.Borders, ImGuiWindowFlags.NoMove)
        g.NavActivateId = backup_activate_id
        ImGui.PopStyleVar(3)
        ImGui.PopStyleColor()
        if not child_visible and not no_clip then
            ImGui.EndChild()
            ImGui.EndGroup()
            return false
        end
        draw_window = g.CurrentWindow -- Child window
        draw_window.DC.NavLayersActiveMaskNext = bit32.bor(draw_window.DC.NavLayersActiveMaskNext, bit32.lshift(1, draw_window.DC.NavLayerCurrent)) -- This is to ensure that EndChild() will display a navigation highlight so we can "enter" into it.
        ImVec2_Copy(draw_window.DC.CursorPos, draw_window.DC.CursorPos + style.FramePadding)
        inner_size.x = inner_size.x - draw_window.ScrollbarSizes.x

        -- FIXME: Could this be a ImGuiChildFlags to affect the SetLastItemDataForWindow() call?
        g.LastItemData.ID = id
        g.LastItemData.ItemFlags = item_data_backup.ItemFlags
        g.LastItemData.StatusFlags = item_data_backup.StatusFlags
    else
        -- Support for internal ImGuiInputTextFlags.MergedItem flag, which could be redesigned as an ItemFlags if needed (with test performed in ItemAdd)
        ImGui.ItemSize(total_bb, style.FramePadding.y)

        if bit32.band(flags, ImGuiInputTextFlags.TempInput) == 0 then
            if not ImGui.ItemAdd(total_bb, id, frame_bb, ImGuiItemFlags.Inputable) then
                return false
            end
        end
    end

    -- Ensure mouse cursor is set even after switching to keyboard/gamepad mode. May generalize further? (#6417)
    local hovered = ImGui.ItemHoverable(frame_bb, id, bit32.bor(g.LastItemData.ItemFlags, ImGuiItemFlags.NoNavDisableMouseHover))
    if hovered then
        ImGui.SetMouseCursor(ImGuiMouseCursor.TextInput)
    end
    if hovered and g.NavHighlightItemUnderNav then
        hovered = false
    end

    -- We are only allowed to access the state if we are already the active widget.
    local state = ImGui.GetInputTextState(id)

    if bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.ReadOnly) ~= 0 then
        flags = bit32.bor(flags, ImGuiInputTextFlags.ReadOnly)
    end
    local is_readonly = bit32.band(flags, ImGuiInputTextFlags.ReadOnly) ~= 0
    local is_password = bit32.band(flags, ImGuiInputTextFlags.Password) ~= 0
    local is_undoable = bit32.band(flags, ImGuiInputTextFlags.NoUndoRedo) == 0
    local is_resizable = bit32.band(flags, ImGuiInputTextFlags.CallbackResize) ~= 0
    if is_resizable then
        IM_ASSERT(callback ~= nil) -- Must provide a callback if you set the ImGuiInputTextFlags.CallbackResize flag!
    end

    -- Word-wrapping: enforcing a fixed width not altered by vertical scrollbar makes things easier, notably to track cursor reliably and avoid one-frame glitches.
    -- Instead of using ImGuiWindowFlags_AlwaysVerticalScrollbar we account for that space if the scrollbar is not visible.
    local is_wordwrap = bit32.band(flags, ImGuiInputTextFlags.WordWrap) ~= 0
    local wrap_width = 0.0
    if is_wordwrap then
        wrap_width = ImMax(1.0, ImGui.GetContentRegionAvail().x + (draw_window.ScrollbarY and 0.0 or -g.Style.ScrollbarSize))
    end

    local user_clicked = hovered and io.MouseClicked[0]
    local input_requested_by_nav = (g.ActiveId ~= id) and (g.NavActivateId == id) and ((bit32.band(g.NavActivateFlags, ImGuiActivateFlags.PreferInput) ~= 0) or (g.NavInputSource == ImGuiInputSource.Keyboard))
    local input_requested_by_reactivate = (g.InputTextReactivateId == id) -- for io.ConfigInputTextEnterKeepActive
    local input_requested_by_user = (user_clicked) or (g.ActiveId == 0 and bit32.band(flags, ImGuiInputTextFlags.TempInput) ~= 0 and g.InputTextDeactivatedState.ID ~= id)
    local scrollbar_id = (is_multiline and state ~= nil) and ImGui.GetWindowScrollbarID(draw_window, ImGuiAxis.Y) or 0
    local user_scroll_finish = is_multiline and state ~= nil and g.ActiveId == 0 and g.ActiveIdPreviousFrame == scrollbar_id
    local user_scroll_active = is_multiline and state ~= nil and g.ActiveId == scrollbar_id
    local clear_active_id = false
    local select_all = false

    local scroll_y = is_multiline and draw_window.Scroll.y or FLT_MAX

    local init_reload_from_user_buf = (state ~= nil and state.WantReloadUserBuf)
    local init_changed_specs_multiline = (state ~= nil and (state.Stb.single_line ~= (not is_multiline))) -- state ~= nil means its our state.
    local init_changed_specs_readonly = (state ~= nil and (bit32.band(bit32.bxor(state.Flags, flags), ImGuiInputTextFlags.ReadOnly) ~= 0)) -- state ~= nil means its our state.
    local init_make_active = (input_requested_by_user or input_requested_by_nav or input_requested_by_reactivate or user_scroll_finish)
    if init_reload_from_user_buf then
        local new_len = ImStd.ImStrlen(buf)
        IM_ASSERT(new_len + 1 <= buf_size, "Is your input buffer properly zero-terminated?")
        state.WantReloadUserBuf = false
        --- @cast state ImGuiInputTextState
        InputTextReconcileUndoState(state, state.TextA.Data, state.TextLen, buf, new_len)
        state.TextA:resize(buf_size + 1) -- we use +1 to make sure that .Data is always pointing to at least an empty string.
        state.TextLen = new_len
        ImStd.memmove(state.TextA.Data, 1, buf, 1, state.TextLen + 1)
        state.Stb.select_start = state.ReloadSelectionStart
        state.Stb.cursor = state.ReloadSelectionEnd
        state.Stb.select_end = state.ReloadSelectionEnd -- will be clamped to bounds below
    elseif (init_make_active and g.ActiveId ~= id) or init_changed_specs_multiline or init_changed_specs_readonly then
        -- Access state even if we don't own it yet.
        state = g.InputTextState
        state:CursorAnimReset()

        -- Backup state of deactivating item so they'll have a chance to do a write to output buffer on the same frame they report IsItemDeactivatedAfterEdit (#4714)
        if (state.ID ~= id and state.ID == g.ActiveId and (init_make_active and g.ActiveId ~= id)) then
            ImGui.InputTextDeactivateHook(state.ID) -- <-- this is essentially an earlier call to what SetActiveID() would do below.
        end

        -- Take a copy of the initial buffer value.
        -- From the moment we focused we are normally ignoring the content of 'buf' (unless we are in read-only mode)
        local buf_len = ImStd.ImStrlen(buf)
        IM_ASSERT(((buf_len + 1 <= buf_size) or (buf_len == 0 and buf_size == 0)), "Is your input buffer properly zero-terminated?")
        if not user_scroll_finish then
            state.TextToRevertTo:resize(buf_len + 1) -- UTF-8. we use +1 to make sure that .Data is always pointing to at least an empty string.
            ImStd.memmove(state.TextToRevertTo.Data, 1, buf, 1, buf_len + 1)
        end

        -- Preserve cursor position and undo/redo stack if we come back to same widget
        -- FIXME: Since we reworked this on 2022/06, may want to differentiate recycle_cursor vs recycle_undostate?
        local recycle_state = (state.ID == id and not init_changed_specs_multiline)
        if (recycle_state and not init_changed_specs_readonly and (state.TextLen ~= buf_len or (state.TextA.Data == nil or ImStd.strncmp(state.TextA.Data, buf, buf_len) ~= 0))) then
            recycle_state = false
        end

        -- Start edition
        state.ID = id
        state.TextLen = buf_len
        state.EditedBefore = false
        if not is_readonly then
            state.TextA:resize(buf_size + 1) -- we use +1 to make sure that .Data is always pointing to at least an empty string.
            ImStd.memmove(state.TextA.Data, 1, buf, 1, state.TextLen + 1)
        end

        -- Find initial scroll position for right alignment
        ImVec2_Copy(state.Scroll, ImVec2(0.0, 0.0))
        if bit32.band(flags, ImGuiInputTextFlags.ElideLeft) ~= 0 then
            state.Scroll.x = state.Scroll.x + ImMax(0.0, ImGui.CalcTextSize(table.concat(buf)).x - frame_size.x + style.FramePadding.x * 2.0) -- FIXME: no table.concat here
        end

        -- Recycle existing cursor/selection/undo stack but clamp position
        -- Note a single mouse click will override the cursor/position immediately by calling stb_textedit_click handler.
        if not recycle_state then
            stbte.initialize_state(state.Stb, not is_multiline)
        end

        if not is_multiline then
            if bit32.band(flags, ImGuiInputTextFlags.AutoSelectAll) ~= 0 then
                select_all = true
            end
            if input_requested_by_nav and (not recycle_state or (bit32.band(g.NavActivateFlags, ImGuiActivateFlags.TryToPreserveState) == 0)) then
                select_all = true
            end
            if user_clicked and io.KeyCtrl then
                select_all = true
            end
        end

        if bit32.band(flags, ImGuiInputTextFlags.AlwaysOverwrite) ~= 0 then
            state.Stb.insert_mode = true -- stb field name is indeed incorrect (see #2863)
        end
    end

    local is_osx = io.ConfigMacOSXBehaviors

    if init_make_active and g.ActiveId ~= id then
        IM_ASSERT(state ~= nil and state.ID == id)
        ImGui.SetActiveID(id, window)
        ImGui.SetFocusID(id, window)
        ImGui.FocusWindow(window)
        if input_requested_by_nav then
            ImGui.SetNavCursorVisibleAfterMove()
        end
    end
    if g.ActiveId == id then
        -- Declare some inputs, the other are registered and polled via Shortcut() routing system.
        -- FIXME: The reason we don't use Shortcut() is we would need a routing flag to specify multiple mods, or to all mods combination into individual shortcuts.
        local always_owned_keys = { ImGuiKey.LeftArrow, ImGuiKey.RightArrow, ImGuiKey.Delete, ImGuiKey.Backspace, ImGuiKey.Home, ImGuiKey.End }
        for _, key in ipairs(always_owned_keys) do
            ImGui.SetKeyOwner(key, id)
        end
        if user_clicked then
            ImGui.SetKeyOwner(ImGuiKey.MouseLeft, id)
        end
        g.ActiveIdUsingNavDirMask = bit32.bor(g.ActiveIdUsingNavDirMask, bit32.lshift(1, ImGuiDir.Left), bit32.lshift(1, ImGuiDir.Right))
        if is_multiline or (bit32.band(flags, ImGuiInputTextFlags.CallbackHistory) ~= 0) then
            g.ActiveIdUsingNavDirMask = bit32.bor(g.ActiveIdUsingNavDirMask, bit32.lshift(1, ImGuiDir.Up), bit32.lshift(1, ImGuiDir.Down))
            ImGui.SetKeyOwner(ImGuiKey.UpArrow, id)
            ImGui.SetKeyOwner(ImGuiKey.DownArrow, id)
        end
        if is_multiline then
            ImGui.SetKeyOwner(ImGuiKey.PageUp, id)
            ImGui.SetKeyOwner(ImGuiKey.PageDown, id)
        end
        -- FIXME: May be a problem to always steal Alt on OSX, would ideally still allow an uninterrupted Alt down-up to toggle menu
        if is_osx then
            ImGui.SetKeyOwner(ImGuiMod_Alt, id)
        end

        -- Expose scroll in a manner that is agnostic to us using a child window
        if is_multiline and state ~= nil then
            state.Scroll.y = draw_window.Scroll.y
        end

        -- Read-only mode always ever read from source buffer. Refresh TextLen when active.
        if is_readonly and state ~= nil then
            state.TextLen = ImStd.ImStrlen(buf)
        end
        if state ~= nil then
            state:CursorClamp()
        end
        -- if is_readonly and state ~= nil then
        --     state.TextA:clear() -- Uncomment to facilitate debugging, but we otherwise prefer to keep/amortize th allocation.
        -- end
    end
    if state ~= nil then
        state.TextSrc = is_readonly and buf or state.TextA.Data
    end

    -- We have an edge case if ActiveId was set through another widget (e.g. widget being swapped), clear id immediately (don't wait until the end of the function)
    if g.ActiveId == id and state == nil then
        ImGui.ClearActiveID()
    end

    -- Release focus when we click outside
    if g.ActiveId == id and io.MouseClicked[0] and not init_make_active then
        clear_active_id = true
    end

    -- Lock the decision of whether we are going to take the path displaying the cursor or selection
    local render_cursor = (g.ActiveId == id) or (state and user_scroll_active) --[[@as bool]]
    local render_selection = state and (state:HasSelection() or select_all) and (RENDER_SELECTION_WHEN_INACTIVE or render_cursor)
    local value_changed = false
    local validated = false

    -- Select the buffer to render.
    local buf_display_from_state = (render_cursor or render_selection or g.ActiveId == id) and not is_readonly and state ~= nil
    local is_displaying_hint = (hint ~= nil and (buf_display_from_state and state.TextA.Data or buf)[1] == 0)

    -- Password pushes a temporary font with only a fallback glyph
    if is_password and not is_displaying_hint then
        ImGui.PushPasswordFont()
    end

    if state ~= nil and state.ID == id then
        state.Flags = flags

        -- Word-wrapping: attempt to keep cursor in view while resizing frame/parent (FIXME-WORDWRAP: would be better to preserve same relative offset)
        if is_wordwrap and state.WrapWidth ~= wrap_width then
            state.CursorCenterY = true
            state.WrapWidth = wrap_width
            render_cursor = true
        end
    end

    -- Process mouse inputs and character inputs
    if g.ActiveId == id then
        --- @cast state ImGuiInputTextState
        IM_ASSERT(state ~= nil)
        state.EditedThisFrame = false
        state.BufCapacity = buf_size
        state.WrapWidth = wrap_width

        -- Although we are active we don't prevent mouse from hovering other elements unless we are interacting right now with the widget.
        -- Down the line we should have a cleaner library-wide concept of Selected vs Active.
        g.ActiveIdAllowOverlap = not io.MouseDown[0]

        -- Edit in progress
        local mouse_x = (io.MousePos.x - frame_bb.Min.x - style.FramePadding.x) + state.Scroll.x
        local mouse_y = (is_multiline and (io.MousePos.y - draw_window.DC.CursorPos.y) or (g.FontSize * 0.5))

        if select_all then
            state:SelectAll()
            state.SelectedAllMouseLock = true
        elseif hovered and io.MouseClickedCount[0] >= 2 and not io.KeyShift then
            stbte.click(state, state.Stb, mouse_x, mouse_y)
            local multiclick_count = (io.MouseClickedCount[0] - 2)
            if multiclick_count % 2 == 0 then
                -- Double-click: Select word
                -- We always use the "Mac" word advance for double-click select vs Ctrl+Right which use the platform dependent variant:
                -- FIXME: There are likely many ways to improve this behavior, but there's no "right" behavior (depends on use-case, software, OS)
                local is_bol = (state.Stb.cursor == 1) or ImStb.TEXTEDIT_GETCHAR(state, state.Stb.cursor - 1) == 10
                if stbte.HAS_SELECTION(state.Stb) or not is_bol then
                    state:OnKeyPressed(STB_TEXTEDIT_K_WORDLEFT)
                end
                -- state:OnKeyPressed(bit32.bor(STB_TEXTEDIT_K_WORDRIGHT, STB_TEXTEDIT_K_SHIFT))
                if not stbte.HAS_SELECTION(state.Stb) then
                    stbte.prep_selection_at_cursor(state.Stb)
                end
                state.Stb.cursor = STB_TEXTEDIT_MOVEWORDRIGHT_MAC(state, state.Stb.cursor)
                state.Stb.select_end = state.Stb.cursor
                stbte.clamp(state, state.Stb)
            else
                -- Triple-click: Select line
                local is_eol = ImStb.TEXTEDIT_GETCHAR(state, state.Stb.cursor) == 10
                state.WrapWidth = 0.0 -- Temporarily disable wrapping so we use real line start.
                state:OnKeyPressed(STB_TEXTEDIT_K_LINESTART)
                state:OnKeyPressed(bit32.bor(STB_TEXTEDIT_K_LINEEND, STB_TEXTEDIT_K_SHIFT))
                state:OnKeyPressed(bit32.bor(STB_TEXTEDIT_K_RIGHT, STB_TEXTEDIT_K_SHIFT))
                state.WrapWidth = wrap_width
                if not is_eol and is_multiline then
                    state.Stb.select_start, state.Stb.select_end = state.Stb.select_end, state.Stb.select_start
                    state.Stb.cursor = state.Stb.select_end
                end
                state.CursorFollow = false
            end
            state:CursorAnimReset()
        elseif io.MouseClicked[0] and not state.SelectedAllMouseLock then
            if hovered then
                if io.KeyShift then
                    stbte.drag(state, state.Stb, mouse_x, mouse_y)
                else
                    stbte.click(state, state.Stb, mouse_x, mouse_y)
                end
                state:CursorAnimReset()
            end
        elseif io.MouseDown[0] and not state.SelectedAllMouseLock and (io.MouseDelta.x ~= 0.0 or io.MouseDelta.y ~= 0.0) then
            stbte.drag(state, state.Stb, mouse_x, mouse_y)
            state:CursorAnimReset()
            state.CursorFollow = true
        end
        if state.SelectedAllMouseLock and not io.MouseDown[0] then
            state.SelectedAllMouseLock = false
        end

        -- We expect backends to emit a Tab key but some also emit a Tab character which we ignore (#2467, #1336)
        -- (For Tab and Enter: Win32/SFML/Allegro are sending both keys and chars, GLFW and SDL are only sending keys. For Space they all send all threes)
        if bit32.band(flags, ImGuiInputTextFlags.AllowTabInput) ~= 0 and not is_readonly then
            if ImGui.Shortcut(ImGuiKey.Tab, ImGuiInputFlags.Repeat, id) then
                local c = 9 -- Insert TAB
                local ret2
                c, ret2 = InputTextFilterCharacter(g, state, c, callback, callback_user_data)
                if ret2 then
                    state:OnCharPressed(c)
                end
            end

            -- FIXME: Implement Shift+Tab
            -- if ImGui.Shortcut(bit32.bor(ImGuiKey.Tab, ImGuiMod_Shift), ImGuiInputFlags.Repeat, id) then
            -- end
        end

        -- Process regular text input (before we check for Return because using some IME will effectively send a Return?)
        -- We ignore Ctrl inputs, but need to allow Alt+Ctrl as some keyboards (e.g. German) use AltGR (which _is_ Alt+Ctrl) to input certain characters.
        local ignore_char_inputs = io.KeyCtrl and not io.KeyAlt
        if io.InputQueueCharacters.Size > 0 then
            if not ignore_char_inputs and not is_readonly and not input_requested_by_nav then
                for n = 1, io.InputQueueCharacters.Size do
                    repeat
                    -- Insert character if they pass filtering
                    local c = io.InputQueueCharacters[n]
                    if c == 9 then -- Skip Tab, see above.
                        break
                    end

                    local ret2
                    c, ret2 = InputTextFilterCharacter(g, state, c, callback, callback_user_data)
                    if ret2 then
                        state:OnCharPressed(c)
                    end

                    until true
                end
            end

            -- Consume characters
            io.InputQueueCharacters:resize(0)
        end
    end

    -- Process other shortcuts/key-presses
    local revert_edit = false
    if g.ActiveId == id and not g.ActiveIdIsJustActivated and not clear_active_id then
        IM_ASSERT(state ~= nil)
        --- @cast state ImGuiInputTextState

        local row_count_per_page = ImMax(ImTrunc((inner_size.y - style.FramePadding.y) / g.FontSize), 1)
        state.Stb.row_count_per_page = row_count_per_page

        local k_mask = (io.KeyShift and STB_TEXTEDIT_K_SHIFT or 0)
        local is_wordmove_key_down = is_osx and io.KeyAlt or io.KeyCtrl -- OS X style: Text editing cursor movement using Alt instead of Ctrl
        local is_startend_key_down = is_osx and io.KeyCtrl and not io.KeySuper and not io.KeyAlt -- OS X style: Line/Text Start and End using Cmd+Arrows instead of Home/End

        -- Using Shortcut() with ImGuiInputFlags.RouteFocused (default policy) to allow routing operations for other code (e.g. calling window trying to use Ctrl+A and Ctrl+B: former would be handled by InputText)
        -- Otherwise we could simply assume that we own the keys as we are active.
        local f_repeat = ImGuiInputFlags.Repeat
        local is_cut   = (ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.X), f_repeat, id) or ImGui.Shortcut(bit32.bor(ImGuiMod_Shift, ImGuiKey.Delete), f_repeat, id)) and not is_readonly and not is_password and (not is_multiline or state:HasSelection())
        local is_copy  = (ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.C), 0,        id) or ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl,  ImGuiKey.Insert), 0,        id)) and not is_password and (not is_multiline or state:HasSelection())
        local is_paste = (ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.V), f_repeat, id) or ImGui.Shortcut(bit32.bor(ImGuiMod_Shift, ImGuiKey.Insert), f_repeat, id)) and not is_readonly
        local is_undo  = (ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.Z), f_repeat, id)) and not is_readonly and is_undoable
        local is_redo  = (ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.Y), f_repeat, id) or ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiMod_Shift, ImGuiKey.Z), f_repeat, id)) and not is_readonly and is_undoable
        local is_select_all = ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.A), 0, id)

        -- We allow validate/cancel with Nav source (gamepad) to makes it easier to undo an accidental NavInput press with no keyboard wired, but otherwise it isn't very useful.
        local nav_gamepad_active  = (bit32.band(io.ConfigFlags, ImGuiConfigFlags.NavEnableGamepad) ~= 0) and (bit32.band(io.BackendFlags, ImGuiBackendFlags.HasGamepad) ~= 0)
        local is_enter            = ImGui.Shortcut(ImGuiKey.Enter, f_repeat, id) or ImGui.Shortcut(ImGuiKey.KeypadEnter, f_repeat, id)
        local is_ctrl_enter       = ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.Enter), f_repeat, id) or ImGui.Shortcut(bit32.bor(ImGuiMod_Ctrl, ImGuiKey.KeypadEnter), f_repeat, id)
        local is_shift_enter      = ImGui.Shortcut(bit32.bor(ImGuiMod_Shift, ImGuiKey.Enter), f_repeat, id) or ImGui.Shortcut(bit32.bor(ImGuiMod_Shift, ImGuiKey.KeypadEnter), f_repeat, id)
        local is_gamepad_validate = nav_gamepad_active and ImGui.IsKeyPressed(ImGuiKey.NavGamepadActivate, false)
        local is_cancel           = ImGui.Shortcut(ImGuiKey.Escape, f_repeat, id) or (nav_gamepad_active and ImGui.Shortcut(ImGuiKey.NavGamepadCancel, f_repeat, id))

        -- FIXME: Should use more Shortcut() and reduce IsKeyPressed()+SetKeyOwner(), but requires modifiers combination to be taken account of.
        -- FIXME-OSX: Missing support for Alt(option)+Right/Left = go to end of line, or next line if already in end of line.
        if ImGui.IsKeyPressed(ImGuiKey.LeftArrow) then
            state:OnKeyPressed(bit32.bor(is_startend_key_down and STB_TEXTEDIT_K_LINESTART or (is_wordmove_key_down and STB_TEXTEDIT_K_WORDLEFT or STB_TEXTEDIT_K_LEFT), k_mask))
        elseif ImGui.IsKeyPressed(ImGuiKey.RightArrow) then
            state:OnKeyPressed(bit32.bor(is_startend_key_down and STB_TEXTEDIT_K_LINEEND or (is_wordmove_key_down and STB_TEXTEDIT_K_WORDRIGHT or STB_TEXTEDIT_K_RIGHT), k_mask))
        elseif ImGui.IsKeyPressed(ImGuiKey.UpArrow) and is_multiline then
            if io.KeyCtrl then
                ImGui.SetScrollY(draw_window, ImMax(draw_window.Scroll.y - g.FontSize, 0.0))
            else
                state:OnKeyPressed(bit32.bor(is_startend_key_down and STB_TEXTEDIT_K_TEXTSTART or STB_TEXTEDIT_K_UP, k_mask))
            end
        elseif ImGui.IsKeyPressed(ImGuiKey.DownArrow) and is_multiline then
            if io.KeyCtrl then
                ImGui.SetScrollY(draw_window, ImMin(draw_window.Scroll.y + g.FontSize, ImGui.GetScrollMaxY()))
            else
                state:OnKeyPressed(bit32.bor(is_startend_key_down and STB_TEXTEDIT_K_TEXTEND or STB_TEXTEDIT_K_DOWN, k_mask))
            end
        elseif ImGui.IsKeyPressed(ImGuiKey.PageUp) and is_multiline then
            state:OnKeyPressed(bit32.bor(STB_TEXTEDIT_K_PGUP, k_mask))
            scroll_y = scroll_y - row_count_per_page * g.FontSize
        elseif ImGui.IsKeyPressed(ImGuiKey.PageDown) and is_multiline then
            state:OnKeyPressed(bit32.bor(STB_TEXTEDIT_K_PGDOWN, k_mask))
            scroll_y = scroll_y + row_count_per_page * g.FontSize
        elseif ImGui.IsKeyPressed(ImGuiKey.Home) then
            state:OnKeyPressed(io.KeyCtrl and bit32.bor(STB_TEXTEDIT_K_TEXTSTART, k_mask) or bit32.bor(STB_TEXTEDIT_K_LINESTART, k_mask))
        elseif ImGui.IsKeyPressed(ImGuiKey.End) then
            state:OnKeyPressed(io.KeyCtrl and bit32.bor(STB_TEXTEDIT_K_TEXTEND, k_mask) or bit32.bor(STB_TEXTEDIT_K_LINEEND, k_mask))
        elseif ImGui.IsKeyPressed(ImGuiKey.Delete) and not is_readonly and not is_cut then
            if not state:HasSelection() then
                -- OSX doesn't seem to have Super+Delete to delete until end-of-line, so we don't emulate that (as opposed to Super+Backspace)
                if is_wordmove_key_down then
                    state:OnKeyPressed(bit32.bor(STB_TEXTEDIT_K_WORDRIGHT, STB_TEXTEDIT_K_SHIFT))
                end
            end
            state:OnKeyPressed(bit32.bor(STB_TEXTEDIT_K_DELETE, k_mask))
        elseif ImGui.IsKeyPressed(ImGuiKey.Backspace) and not is_readonly then
            if not state:HasSelection() then
                if is_wordmove_key_down then
                    state:OnKeyPressed(bit32.bor(STB_TEXTEDIT_K_WORDLEFT, STB_TEXTEDIT_K_SHIFT))
                elseif is_osx and io.KeyCtrl and not io.KeyAlt and not io.KeySuper then
                    state:OnKeyPressed(bit32.bor(STB_TEXTEDIT_K_LINESTART, STB_TEXTEDIT_K_SHIFT))
                end
            end
            state:OnKeyPressed(bit32.bor(STB_TEXTEDIT_K_BACKSPACE, k_mask))
        elseif is_enter or is_ctrl_enter or is_shift_enter or is_gamepad_validate then
            -- Determine if we turn Enter into a \n character
            local ctrl_enter_for_new_line = bit32.band(flags, ImGuiInputTextFlags.CtrlEnterForNewLine) ~= 0
            local is_new_line = is_multiline and not is_gamepad_validate and (is_shift_enter or (is_enter and not ctrl_enter_for_new_line) or (is_ctrl_enter and ctrl_enter_for_new_line))
            if not is_new_line then
                validated = true
                clear_active_id = true
                if io.ConfigInputTextEnterKeepActive and not is_multiline and not is_ctrl_enter and not is_shift_enter then
                    -- Queue reactivation, so that e.g. IsItemDeactivatedAfterEdit() will work. (#9001)
                    state:SelectAll() -- No need to scroll
                    g.InputTextReactivateId = id -- Mark for reactivation on next frame
                end
            elseif not is_readonly then
                -- Insert new line
                local c = 10
                local ret2
                c, ret2 = InputTextFilterCharacter(g, state, c, callback, callback_user_data)
                if ret2 then
                    state:OnCharPressed(c)
                end
            end
        elseif is_cancel then
            if bit32.band(flags, ImGuiInputTextFlags.EscapeClearsAll) ~= 0 then
                if state.TextA.Data[1] ~= 0 then
                    revert_edit = true
                else
                    render_cursor = false
                    render_selection = false
                    clear_active_id = true
                end
            else
                clear_active_id = true
                revert_edit = true
                render_cursor = false
                render_selection = false
            end
        elseif is_undo or is_redo then
            state:OnKeyPressed(is_undo and STB_TEXTEDIT_K_UNDO or STB_TEXTEDIT_K_REDO)
            state:ClearSelection()
        elseif is_select_all then
            state:SelectAll()
            state.CursorFollow = true
        elseif is_cut or is_copy then
            -- Cut, Copy
            if g.PlatformIO.Platform_SetClipboardTextFn ~= nil then
                -- SetClipboardText() only takes null terminated strings + state.TextSrc may point to read-only user buffer, so we need to make a copy.
                local ib = state:HasSelection() and ImMin(state.Stb.select_start, state.Stb.select_end) or 1
                local ie = state:HasSelection() and ImMax(state.Stb.select_start, state.Stb.select_end) or state.TextLen + 1
                g.TempBuffer:reserve(ie - ib + 1)
                ImStd.memmove(g.TempBuffer.Data, 1, state.TextSrc, ib, ie - ib)
                g.TempBuffer.Data[ie - ib + 1] = 0
                ImGui.SetClipboardText(ImGui._ByteArrayToString(g.TempBuffer.Data, 1, ie - ib + 1))
            end
            if is_cut then
                if not state:HasSelection() then
                    state:SelectAll()
                end
                state.CursorFollow = true
                stbte.cut(state, state.Stb)
            end
        elseif is_paste then
            local clipboard = ImGui.GetClipboardText()
            if clipboard then
                -- Filter pasted buffer
                local clipboard_len = #clipboard
                local clipboard_end = clipboard_len + 1
                local clipboard_filtered = ImVector()
                clipboard_filtered:reserve(clipboard_len + 1)
                local s
                local i = 1
                while i <= clipboard_len do
                    repeat
                    s = string.byte(clipboard, i)
                    local c, ret2
                    local in_len
                    in_len, c = ImStd.ImTextCharFromUtf8(clipboard, i, clipboard_end)
                    i = i + in_len
                    c, ret2 = InputTextFilterCharacter(g, state, c, callback, callback_user_data, true)
                    if not ret2 then
                        break -- continue
                    end

                    local c_utf8 = {0, 0, 0, 0, 0}
                    ImStd.ImTextCharToUtf8(c_utf8, c)
                    local out_len = ImStd.ImStrlen(c_utf8)
                    clipboard_filtered:resize(clipboard_filtered.Size + out_len)
                    ImStd.memmove(clipboard_filtered.Data, clipboard_filtered.Size - out_len + 1, c_utf8, 1, out_len)

                    until true
                end
                if clipboard_filtered.Size > 0 then -- If everything was filtered, ignore the pasting operation
                    clipboard_filtered:push_back(0)
                    stbte.paste(state, state.Stb, clipboard_filtered.Data, clipboard_filtered.Size - 1)
                    state.CursorFollow = true
                end
            end
        end

        -- Update render selection flag after events have been handled, so selection highlight can be displayed during the same frame.
        render_selection = render_selection or (state:HasSelection() and (RENDER_SELECTION_WHEN_INACTIVE or render_cursor))
    end

    -- Process revert and user callbacks
    local apply_new_text = nil
    local apply_new_text_length = 0
    if g.ActiveId == id then
        IM_ASSERT(state ~= nil)
        --- @cast state ImGuiInputTextState

        if revert_edit and not is_readonly then
            if bit32.band(flags, ImGuiInputTextFlags.EscapeClearsAll) ~= 0 then
                -- Clear input
                IM_ASSERT(state.TextA.Data[1] ~= 0)
                apply_new_text = {0}
                apply_new_text_length = 0
                value_changed = true
                local empty_string = {0}
                ImStb.stb_textedit_replace(state, state.Stb, empty_string, 0)
            elseif ImStd.strcmp(state.TextA.Data, state.TextToRevertTo.Data) ~= 0 then
                apply_new_text = state.TextToRevertTo.Data
                apply_new_text_length = state.TextToRevertTo.Size - 1

                -- Restore initial value. Only return true if restoring to the initial value changes the current buffer contents.
                -- Push records into the undo stack so we can Ctrl+Z the revert operation itself
                value_changed = true
                ImStb.stb_textedit_replace(state, state.Stb, state.TextToRevertTo.Data, state.TextToRevertTo.Size - 1)
            end
        end

        -- User callback
        if bit32.band(flags, bit32.bor(ImGuiInputTextFlags.CallbackCompletion, ImGuiInputTextFlags.CallbackHistory, ImGuiInputTextFlags.CallbackEdit, ImGuiInputTextFlags.CallbackAlways)) ~= 0 then
            IM_ASSERT(callback ~= nil)

            -- The reason we specify the usage semantic (Completion/History) is that Completion needs to disable keyboard TABBING at the moment.

            local event_flag = 0
            local event_key = ImGuiKey.None
            if bit32.band(flags, ImGuiInputTextFlags.CallbackCompletion) ~= 0 and ImGui.Shortcut(ImGuiKey.Tab, 0, id) then
                event_flag = ImGuiInputTextFlags.CallbackCompletion
                event_key = ImGuiKey.Tab
            elseif bit32.band(flags, ImGuiInputTextFlags.CallbackHistory) ~= 0 and ImGui.IsKeyPressed(ImGuiKey.UpArrow) then
                event_flag = ImGuiInputTextFlags.CallbackHistory
                event_key = ImGuiKey.UpArrow
            elseif bit32.band(flags, ImGuiInputTextFlags.CallbackHistory) ~= 0 and ImGui.IsKeyPressed(ImGuiKey.DownArrow) then
                event_flag = ImGuiInputTextFlags.CallbackHistory
                event_key = ImGuiKey.DownArrow
            elseif bit32.band(flags, ImGuiInputTextFlags.CallbackEdit) ~= 0 and state.EditedThisFrame then
                event_flag = ImGuiInputTextFlags.CallbackEdit
            elseif bit32.band(flags, ImGuiInputTextFlags.CallbackAlways) ~= 0 then
                event_flag = ImGuiInputTextFlags.CallbackAlways
            end

            if event_flag ~= 0 then
                local callback_data = ImGuiInputTextCallbackData()
                callback_data.Ctx = g
                callback_data.ID = id
                callback_data.Flags = flags
                callback_data.EventFlag = event_flag
                callback_data.EventActivated = (g.ActiveId == state.ID and g.ActiveIdIsJustActivated)
                callback_data.UserData = callback_user_data

                -- FIXME-OPT: Undo stack reconcile needs a backup of the data until we rework API, see #7925
                local callback_buf = is_readonly and buf or state.TextA.Data
                IM_ASSERT(callback_buf == state.TextSrc)
                state.CallbackTextBackup:resize(state.TextLen + 1)
                ImStd.memmove(state.CallbackTextBackup.Data, 1, callback_buf, 1, state.TextLen + 1)

                callback_data.EventKey = event_key
                callback_data.Buf = callback_buf
                callback_data.BufTextLen = state.TextLen
                callback_data.BufSize = state.BufCapacity
                callback_data.BufDirty = false
                callback_data.CursorPos = state.Stb.cursor
                callback_data.SelectionStart = state.Stb.select_start
                callback_data.SelectionEnd = state.Stb.select_end

                -- Call user code
                callback(callback_data)

                -- Read back what user may have modified
                callback_buf = is_readonly and buf or state.TextA.Data -- Pointer may have been invalidated by a resize callback
                IM_ASSERT(callback_data.Buf == callback_buf) -- Invalid to modify those fields
                IM_ASSERT(callback_data.BufSize == state.BufCapacity)
                IM_ASSERT(callback_data.Flags == flags)
                if callback_data.BufDirty or callback_data.CursorPos ~= state.Stb.cursor then
                    state.CursorFollow = true
                end
                state.Stb.cursor = ImClamp(callback_data.CursorPos, 0, callback_data.BufTextLen)
                state.Stb.select_start = ImClamp(callback_data.SelectionStart, 0, callback_data.BufTextLen)
                state.Stb.select_end = ImClamp(callback_data.SelectionEnd, 0, callback_data.BufTextLen)
                if callback_data.BufDirty then
                    -- Callback may update buffer and thus set buf_dirty even in read-only mode.
                    IM_ASSERT(callback_data.BufTextLen == ImStd.ImStrlen(callback_data.Buf)) -- You need to maintain BufTextLen if you change the text!
                    InputTextReconcileUndoState(state, state.CallbackTextBackup.Data, state.CallbackTextBackup.Size - 1, callback_data.Buf, callback_data.BufTextLen)
                    state.TextLen = callback_data.BufTextLen -- Assume correct length and valid UTF-8 from user, saves us an extra strlen()
                    state.EditedBefore = true; state.EditedThisFrame = true
                    state:CursorAnimReset()
                end
            end
        end

        -- Write back result string if modified.
        -- FIXME-OPT: Could mark dirty state from the stb_textedit callbacks
        if not is_readonly then
            if bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.LiveEditOnInputScalar) ~= 0 then
                -- Apply when modified
                if (ImStd.strcmp(state.TextSrc, buf) ~= 0) then
                    apply_new_text = state.TextSrc
                    apply_new_text_length = state.TextLen
                    value_changed = true
                end
            else
                -- Apply on validation/deactivation, otherwise cancel out previous apply attempts (e.g. revert)
                value_changed = ((validated or clear_active_id or revert_edit) and ImStd.strcmp(state.TextSrc, buf) ~= 0)
                apply_new_text = value_changed and state.TextSrc or NULL
                apply_new_text_length = value_changed and state.TextLen or 0
            end
        end
    end

    -- Handle reapplying final data on deactivation (see InputTextDeactivateHook() for details)
    -- This is used when e.g. losing focus or tabbing out into another InputText() which may already be using the temp buffer.
    if g.InputTextDeactivatedState.ID == id then
        -- The state only exists after an Edit. IsItemDeactivatedAfterEdit() is not valid in every code path (see "widgets_inputtext_status_noliveedit" test).
        if ((g.ActiveId ~= id and ImGui.IsItemDeactivated()) or (g.ActiveId == id and bit32.band(flags, ImGuiInputTextFlags.TempInput) ~= 0)) then
            if (not is_readonly and ImStd.strcmp(g.InputTextDeactivatedState.TextA.Data, buf) ~= 0) then
                apply_new_text = g.InputTextDeactivatedState.TextA.Data
                apply_new_text_length = g.InputTextDeactivatedState.TextA.Size - 1
                value_changed = true
                -- IMGUI_DEBUG_LOG("InputText(): apply Deactivated data for 0x%08X: \"%.*s\".\n", id, apply_new_text_length, apply_new_text);
            end
        end
        g.InputTextDeactivatedState.ID = 0
    end

    -- Write back result to user buffer. This can currently only happen when (g.ActiveId == id) or when just deactivated.
    -- - As soon as the InputText() is active, our stored in-widget value gets priority over any underlying modification of the user buffer.
    -- - Make sure we always reapply the live buffer back to the input/user buffer before clearing ActiveId, even thought strictly speaking
    --   it was not modified on this frame. This allows the user to use InputText() without maintaining any user-side storage.
    --   (PS: if you use this property together with ImGuiInputTextFlags.CallbackResize, you are at the risk of recreating a temporary
    --    allocated/string object every frame. Which in the grand scheme of scheme is nothing, but isn't dear imgui vibe).
    if apply_new_text ~= nil then
        IM_ASSERT(apply_new_text_length >= 0)
        if is_resizable then
            local callback_data = ImGuiInputTextCallbackData()
            callback_data.Ctx = g
            callback_data.ID = id
            callback_data.Flags = flags
            callback_data.EventFlag = ImGuiInputTextFlags.CallbackResize
            callback_data.EventActivated = (g.ActiveId == state.ID and g.ActiveIdIsJustActivated)
            callback_data.Buf = buf
            callback_data.BufTextLen = apply_new_text_length
            callback_data.BufSize = ImMax(buf_size, apply_new_text_length + 1)
            callback_data.UserData = callback_user_data

            callback(callback_data)

            buf = callback_data.Buf
            buf_size = callback_data.BufSize
            apply_new_text_length = ImMin(callback_data.BufTextLen, buf_size - 1)
            IM_ASSERT(apply_new_text_length <= buf_size)
        end
        -- IMGUI_DEBUG_PRINT("InputText(\"%s\"): apply_new_text length %d\n", label, apply_new_text_length);

        -- If the underlying buffer resize was denied or not carried to the next frame, apply_new_text_length+1 may be >= buf_size.
        ImStd.ImStrncpy(buf, 1, apply_new_text, 1, ImMin(apply_new_text_length + 1, buf_size))
    end

    -- Release active ID at the end of the function (so e.g. pressing Return still does a final application of the value)
    -- Otherwise request text input ahead for next frame.
    if g.ActiveId == id and clear_active_id then
        state.ID = 0
        ImGui.ClearActiveID()
        state.ID = id
    end

    -- Render frame
    if not is_multiline then
        ImGui.RenderNavCursor(frame_bb, id)
        ImGui.RenderFrame(frame_bb.Min, frame_bb.Max, ImGui.GetColorU32(ImGuiCol.FrameBg), true, style.FrameRounding)
    end

    local draw_pos = ImVec2()
    ImVec2_Copy(draw_pos, is_multiline and draw_window.DC.CursorPos or (frame_bb.Min + style.FramePadding))
    local clip_rect = ImRect(frame_bb.Min.x, frame_bb.Min.y, frame_bb.Min.x + inner_size.x, frame_bb.Min.y + inner_size.y) -- Not using frame_bb.Max because we have adjusted size
    if is_multiline then
        clip_rect:ClipWith(draw_window.ClipRect)
    end

    -- Set upper limit of single-line InputTextEx() at 2 million characters strings. The current pathological worst case is a long line
    -- without any carriage return, which would makes ImFont::RenderText() reserve too many vertices and probably crash. Avoid it altogether.
    -- Note that we only use this limit on single-line InputText(), so a pathologically large line on a InputTextMultiline() would still crash.
    local buf_display_max_length = 2 * 1024 * 1024
    local buf_display = buf_display_from_state and state.TextA.Data or buf
    local buf_display_end = nil -- We have specialized paths below for setting the length

    -- Display hint when contents is empty
    -- At this point we need to handle the possibility that a callback could have modified the underlying buffer (#8368)
    local new_is_displaying_hint = (hint ~= nil and (buf_display_from_state and state.TextA.Data or buf)[1] == 0)
    if new_is_displaying_hint ~= is_displaying_hint then
        if is_password and not is_displaying_hint then
            ImGui.PopPasswordFont()
        end
        is_displaying_hint = new_is_displaying_hint
        if is_password and not is_displaying_hint then
            ImGui.PushPasswordFont()
        end
    end
    if is_displaying_hint then
        --- @cast hint char[]
        buf_display = hint
        buf_display_end = ImStd.ImStrlen(hint) + 1
    else
        if render_cursor or render_selection or g.ActiveId == id then
            buf_display_end = state.TextLen + 1
        elseif is_multiline and not is_wordwrap then
            buf_display_end = nil -- Inactive multi-line: end of buffer will be output by InputTextLineIndexBuild() special strchr() path.
        else
            buf_display_end = ImStd.ImStrlen(buf_display) + 1
        end
    end

    -- Calculate visibility
    local line_visible_n0, line_visible_n1 = 1, 2
    if is_multiline then
        line_visible_n0, line_visible_n1 = ImGui.CalcClipRectVisibleItemsY(clip_rect, draw_pos, g.FontSize)
    end

    -- Build line index for easy data access (makes code below simpler and faster)
    local line_index = g.InputTextLineIndex
    line_index.Offsets:resize(0)
    local line_count = 1
    if is_multiline then
        -- If scrolling is expected to change build full index.
        -- FIXME-OPT: Could append to index when new value of line_visible_n1 becomes bigger, see second call to CalcClipRectVisibleItemsY() below.
        local will_scroll_y = state and ((state.CursorFollow and render_cursor) or (state.CursorCenterY and (render_cursor or render_selection)))
        --- @cast buf_display_end int
        local out_buf_end
        line_count, out_buf_end = InputTextLineIndexBuild(flags, line_index, buf_display, buf_display_end, wrap_width, will_scroll_y and INT_MAX or (line_visible_n1 + 1))
        if buf_display_end then
            buf_display_end = out_buf_end
        end
    end
    line_index.EndOffset = buf_display_end - 1
    line_visible_n1 = ImMin(line_visible_n1, line_count + 1)

    -- Store text height (we don't need width)
    local text_size_y = line_count * g.FontSize
    -- ImGui.GetForegroundDrawList():AddRect(draw_pos + ImVec2(0, line_visible_n0 * g.FontSize), draw_pos + ImVec2(frame_size.x, line_visible_n1 * g.FontSize), IM_COL32(255, 0, 0, 255))

    -- Calculate blinking cursor position
    --- @cast buf_display_end int
    local cursor_offset = (render_cursor and state) and InputTextLineIndexGetPosOffset(g, state, line_index, buf_display, buf_display_end, state.Stb.cursor) or ImVec2(0.0, 0.0)
    local draw_scroll = ImVec2()

    -- Render text. We currently only render selection when the widget is active or while scrolling.
    local text_col = ImGui.GetColorU32(is_displaying_hint and ImGuiCol.TextDisabled or ImGuiCol.Text)
    if render_cursor or render_selection then
        -- Render text (with cursor and selection)
        -- This is going to be messy. We need to:
        -- - Display the text (this alone can be more easily clipped)
        -- - Handle scrolling, highlight selection, display cursor (those all requires some form of 1d->2d cursor position calculation)
        -- - Measure text height (for scrollbar)
        -- We are attempting to do most of that in **one main pass** to minimize the computation cost (non-negligible for large amount of text) + 2nd pass for selection rendering (we could merge them by an extra refactoring effort)
        -- FIXME: This should occur on buf_display but we'd need to maintain cursor/select_start/select_end for UTF-8.
        IM_ASSERT(state ~= nil)
        state.LineCount = line_count

        -- Scroll
        local new_scroll_y = scroll_y
        if render_cursor and state.CursorFollow then
            -- Horizontal scroll in chunks of quarter width
            if bit32.band(flags, ImGuiInputTextFlags.NoHorizontalScroll) == 0 then
                local scroll_increment_x = inner_size.x * 0.25
                local visible_width = inner_size.x - style.FramePadding.x
                if cursor_offset.x < state.Scroll.x then
                    state.Scroll.x = IM_TRUNC(ImMax(0.0, cursor_offset.x - scroll_increment_x))
                elseif cursor_offset.x - visible_width >= state.Scroll.x then
                    state.Scroll.x = IM_TRUNC(cursor_offset.x - visible_width + scroll_increment_x)
                end
            else
                state.Scroll.x = 0.0
            end

            -- Vertical scroll
            if is_multiline then
                -- Test if cursor is vertically visible
                if cursor_offset.y - g.FontSize < scroll_y then
                    new_scroll_y = ImMax(0.0, cursor_offset.y - g.FontSize)
                elseif cursor_offset.y - (inner_size.y - style.FramePadding.y * 2.0) >= scroll_y then
                    new_scroll_y = cursor_offset.y - inner_size.y + style.FramePadding.y * 2.0
                end
            end
            state.CursorFollow = false
        end
        if state.CursorCenterY then
            if is_multiline then
                new_scroll_y = cursor_offset.y - g.FontSize - (inner_size.y * 0.5 - style.FramePadding.y)
            end
            state.CursorCenterY = false
            render_cursor = false
        end
        if new_scroll_y ~= scroll_y then
            local scroll_max_y = ImMax((text_size_y + style.FramePadding.y * 2.0) - inner_size.y, 0.0)
            scroll_y = ImClamp(new_scroll_y, 0.0, scroll_max_y)
            draw_pos.y = draw_pos.y + (draw_window.Scroll.y - scroll_y) -- Manipulate cursor pos immediately avoid a frame of lag
            draw_window.Scroll.y = scroll_y
            line_visible_n0, line_visible_n1 = ImGui.CalcClipRectVisibleItemsY(clip_rect, draw_pos, g.FontSize)
            line_visible_n1 = ImMin(line_visible_n1, line_count)
        end

        -- Draw selection
        draw_scroll.x = state.Scroll.x
        if render_selection then
            local bg_color = ImGui.GetColorU32(ImGuiCol.TextSelectedBg, render_cursor and 1.0 or 0.6) -- FIXME: current code flow mandate that render_cursor is always true here, we are leaving the transparent one for tests.
            local bg_offy_up = is_multiline and 0.0 or -1.0 -- FIXME-DPI: those offsets should be part of the style? they don't play so well with multi-line selection.
            local bg_offy_dn = is_multiline and 0.0 or 2.0
            local bg_eol_width = IM_TRUNC(g.FontBaked:GetCharAdvance(32) * 0.50) -- So we can see selected empty lines

            local text_selected_begin = ImMin(state.Stb.select_start, state.Stb.select_end)
            local text_selected_end = ImMax(state.Stb.select_start, state.Stb.select_end)
            for line_n = line_visible_n0, line_visible_n1 - 1 do
                repeat
                local p = line_index:get_line_begin(1, line_n)
                local p_eol = line_index:get_line_end(1, line_n)
                local p_eol_is_wrap = (p_eol < buf_display_end and buf_display[p_eol] ~= 10)
                if p_eol_is_wrap then
                    p_eol = p_eol + 1
                end
                local line_selected_begin = (text_selected_begin > p) and text_selected_begin or p
                local line_selected_end = (text_selected_end < p_eol) and text_selected_end or p_eol

                local rect_width = 0.0
                if line_selected_begin < line_selected_end then
                    rect_width = rect_width + ImGui.CalcTextSizeEx(buf_display, line_selected_begin, line_selected_end).x
                end
                if text_selected_begin <= p_eol and text_selected_end > p_eol and not p_eol_is_wrap then
                    rect_width = rect_width + bg_eol_width -- So we can see selected empty lines
                end
                if rect_width == 0.0 then
                    break
                end

                local rect = ImRect()
                rect.Min.x = draw_pos.x - draw_scroll.x + ImGui.CalcTextSizeEx(buf_display, p, line_selected_begin).x
                rect.Min.y = draw_pos.y - draw_scroll.y + (line_n - 1) * g.FontSize
                rect.Max.x = rect.Min.x + rect_width
                rect.Max.y = rect.Min.y + bg_offy_dn + g.FontSize
                rect.Min.y = rect.Min.y + bg_offy_up
                rect:ClipWith(clip_rect)
                draw_window.DrawList:AddRectFilled(rect.Min, rect.Max, bg_color)

                until true
            end
        end
    end

    -- Find render position for right alignment (single-line only)
    if g.ActiveId ~= id and bit32.band(flags, ImGuiInputTextFlags.ElideLeft) ~= 0 and not render_cursor and not render_selection then
        draw_pos.x = ImMin(draw_pos.x, frame_bb.Max.x - ImGui.CalcTextSize(buf_display, nil).x - style.FramePadding.x)
    end
    -- draw_scroll.x = state.Scroll.x -- Preserve scroll when inactive?

    -- Render text
    if (is_multiline or (buf_display_end - 1) < buf_display_max_length) and bit32.band(text_col, IM_COL32_A_MASK) ~= 0 and line_visible_n0 < line_visible_n1 then
        g.Font:RenderText(draw_window.DrawList, g.FontSize,
        draw_pos - draw_scroll + ImVec2(0.0, (line_visible_n0 - 1) * g.FontSize),
        text_col, clip_rect:AsVec4(),
        buf_display,
        line_index:get_line_begin(1, line_visible_n0),
        line_index:get_line_end(1, line_visible_n1 - 1),
        wrap_width, bit32.bor(ImDrawTextFlags.WrapKeepBlanks, ImDrawTextFlags.CpuFineClip))
    end

    -- Render blinking cursor
    if render_cursor then
        state.CursorAnim = state.CursorAnim + io.DeltaTime
        local cursor_is_visible = (not g.IO.ConfigInputTextCursorBlink) or (state.CursorAnim <= 0.0) or (ImFmod(state.CursorAnim, 1.20) <= 0.80)

        local cursor_screen_pos = ImTrunc(draw_pos + cursor_offset - draw_scroll)
        local cursor_screen_rect = ImRect(cursor_screen_pos.x, cursor_screen_pos.y - g.FontSize + 0.5, cursor_screen_pos.x + 1.0, cursor_screen_pos.y - 1.5)

        if cursor_is_visible and cursor_screen_rect:Overlaps(clip_rect) then
            draw_window.DrawList:AddLineV(cursor_screen_rect.Min.x, cursor_screen_rect.Min.y, cursor_screen_rect.Max.y, ImGui.GetColorU32(ImGuiCol.InputTextCursor), style.InputTextCursorSize)
        end

        -- Notify OS of text input position for advanced IME (-1 x offset so that Windows IME can cover our cursor. Bit of an extra nicety.)
        -- This is required for some backends (SDL3) to start emitting character/text inputs.
        -- As per #6341, make sure we don't set that on the deactivating frame.
        if not is_readonly and g.ActiveId == id then
            local ime_data = g.PlatformImeData -- (this is a public struct, passed to io.Platform_SetImeDataFn() handler)
            ime_data.WantVisible = true
            ime_data.WantTextInput = true
            ImVec2_Copy(ime_data.InputPos, ImVec2(cursor_screen_pos.x - 1.0, cursor_screen_pos.y - g.FontSize))
            ime_data.InputLineHeight = g.FontSize
            ime_data.ViewportId = window.Viewport.ID
        end
    end

    if is_password and not is_displaying_hint then
        ImGui.PopPasswordFont()
    end

    if is_multiline then
        -- For focus requests to work on our multiline we need to ensure our child ItemAdd() call specifies the ImGuiItemFlags.Inputable (see #4761, #7870)...
        ImGui.Dummy(ImVec2(0.0, text_size_y + style.FramePadding.y))
        g.NextItemData.ItemFlagsSet = bit32.bor(g.NextItemData.ItemFlagsSet, ImGuiItemFlags.Inputable, ImGuiItemFlags.NoTabStop)
        ImGui.EndChild()
        item_data_backup.StatusFlags = bit32.bor(item_data_backup.StatusFlags, bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HoveredWindow))

        -- ...and then we need to undo the group overriding last item data, which gets a bit messy as EndGroup() tries to forward scrollbar being active...
        -- FIXME: This quite messy/tricky, should attempt to get rid of the child window.
        ImGui.EndGroup()
        if g.LastItemData.ID == 0 or g.LastItemData.ID ~= ImGui.GetWindowScrollbarID(draw_window, ImGuiAxis.Y) then
            g.LastItemData.ID = id
            g.LastItemData.ItemFlags = item_data_backup.ItemFlags
            g.LastItemData.StatusFlags = item_data_backup.StatusFlags
        end
    end

    if state and is_readonly then
        state.TextSrc = nil
    end

    if label_size.x > 0.0 then
        ImGui.RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y), label, 1, label_end, false)
    end

    if value_changed then
        ImGui.MarkItemEdited(id)
    end

    if bit32.band(flags, ImGuiInputTextFlags.EnterReturnsTrue) ~= 0 then
        return validated
    else
        return value_changed
    end
end

--- @param label      string
--- @param hint       char[]
--- @param buf        char[]
--- @param buf_size   size_t
--- @param flags?     ImGuiInputTextFlags
--- @param callback?  ImGuiInputTextCallback
--- @param user_data? any
function ImGui.InputTextWithHint(label, hint, buf, buf_size, flags, callback, user_data)
    if flags == nil then flags = 0 end

    IM_ASSERT(bit32.band(flags, ImGuiInputTextFlags.Multiline) == 0) -- call InputTextMultiline() or  InputTextEx() manually if you need multi-line + hint.
    return ImGui.InputTextEx(label, hint, buf, buf_size, ImVec2(0, 0), flags, callback, user_data)
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: ColorEdit, ColorPicker, ColorButton, etc.
-------------------------------------------------------------------------------
-- - ColorEdit3()
-- - ColorEdit4()
-- - ColorPicker3()
-- - RenderColorRectWithAlphaCheckerboard() [Internal]
-- - ColorPicker4()
-- - ColorButton()
-- - ColorTooltip() [Internal]
-- - ColorEditOptionsPopup() [Internal]
-- - ColorPickerOptionsPopup() [Internal]
-------------------------------------------------------------------------------

--- @param col float[]
--- @param H   float
--- @return float
local function ColorEditRestoreH(col, H)
    local g = GImGui
    IM_ASSERT(g.ColorEditCurrentID ~= 0)
    if g.ColorEditSavedID ~= g.ColorEditCurrentID or g.ColorEditSavedColor ~= ImGui.ColorConvertFloat4ToU32(ImVec4(col[1], col[2], col[3], 0)) then
        return H
    end
    H = g.ColorEditSavedHue
    return H
end

-- ColorEdit supports RGB and HSV inputs. In case of RGB input resulting color may have undefined hue and/or saturation.
-- Since widget displays both RGB and HSV values we must preserve hue and saturation to prevent these values resetting.
--- @param col float[]
--- @param H float
--- @param S float
--- @param V float
--- @return float, float, float
local function ColorEditRestoreHS(col, H, S, V)
    local g = GImGui
    IM_ASSERT(g.ColorEditCurrentID ~= 0)

    if g.ColorEditSavedID ~= g.ColorEditCurrentID or g.ColorEditSavedColor ~= ImGui.ColorConvertFloat4ToU32(ImVec4(col[1], col[2], col[3], 0)) then
        return H, S, V
    end

    -- When S == 0, H is undefined.
    -- When H == 1 it wraps around to 0.
    if S == 0.0 or (H == 0.0 and g.ColorEditSavedHue == 1) then
        H = g.ColorEditSavedHue
    end

    -- When V == 0, S is undefined.
    if V == 0.0 then
        S = g.ColorEditSavedSat
    end

    return H, S, V
end

do --[[ColorEdit4]]

local ids = { "##X", "##Y", "##Z", "##W" }
local fmt_table_int = {
    {   "%3d",   "%3d",   "%3d",   "%3d" }, -- Short display
    { "R:%3d", "G:%3d", "B:%3d", "A:%3d" }, -- Long display for RGBA
    { "H:%3d", "S:%3d", "V:%3d", "A:%3d" }  -- Long display for HSVA
}
local fmt_table_float = {
    {   "%0.3f",   "%0.3f",   "%0.3f",   "%0.3f" }, -- Short display
    { "R:%0.3f", "G:%0.3f", "B:%0.3f", "A:%0.3f" }, -- Long display for RGBA
    { "H:%0.3f", "S:%0.3f", "V:%0.3f", "A:%0.3f" }  -- Long display for HSVA
}

-- Edit colors components (each component in 0.0f..1.0f range).
-- See enum ImGuiColorEditFlags_ for available options. e.g. Only access 3 floats if ImGuiColorEditFlags.NoAlpha flag is set.
-- With typical options: Left-click on color square to open color picker. Right-click to open option menu. Ctrl+Click over input fields to edit them and TAB to go to next item.
--- @param label string
--- @param col   float[]
--- @param flags ImGuiColorEditFlags

function ImGui.ColorEdit4(label, col, flags)
    if flags == nil then flags = 0 end
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local style = g.Style
    local square_sz = ImGui.GetFrameHeight()
    local label_display_end = ImGui.FindRenderedTextEnd(label)
    local w_full = ImGui.CalcItemWidth()
    g.NextItemData:ClearFlags()

    -- [Luau] Fast path for a row that is entirely clipped (e.g. long lists such as Style Editor > Colors): nothing
    -- inside would draw, be hovered or receive input, so only reproduce the layout (same group size, baseline and
    -- last item rect as the full path). Not taken while anything could depend on the inner items: an active item
    -- or popup, keyboard navigation, logging, or the ID debug hook.
    if label_display_end == 1 and bit32.band(flags, bit32.bor(ImGuiColorEditFlags.NoInputs, ImGuiColorEditFlags.NoSmallPreview)) == 0
        and g.ActiveId == 0 and g.OpenPopupStack.Size == 0 and not g.NavCursorVisible and not g.NavAnyRequest
        and not g.LogEnabled and g.DebugHookIdInfoId == 0 then
        local w_button = square_sz + style.ItemInnerSpacing.x
        local w = ImMax(w_full - w_button, 1.0) + w_button
        local p = window.DC.CursorPos
        local cr = window.ClipRect
        if p.y + square_sz < cr.Min.y or p.y > cr.Max.y or p.x + w < cr.Min.x or p.x > cr.Max.x then
            ImGui.BeginGroup()
            local bb = ImRect(p.x, p.y, p.x + w, p.y + square_sz)
            ImGui.ItemSize(ImVec2(w, square_sz), style.FramePadding.y)
            ImGui.ItemAdd(bb, 0)
            ImGui.EndGroup()
            return false
        end
    end

    ImGui.BeginGroup()
    ImGui.PushID(label)
    local set_current_color_edit_id = (g.ColorEditCurrentID == 0)
    if set_current_color_edit_id then
        g.ColorEditCurrentID = window.IDStack:back()
    end

    -- If we're not showing any slider there's no point in doing any HSV conversions
    local flags_untouched = flags
    if bit32.band(flags, ImGuiColorEditFlags.NoInputs) ~= 0 then
        flags = bit32.bor(bit32.band(flags, bit32.bnot(ImGuiColorEditFlags.DisplayMask_)), ImGuiColorEditFlags.DisplayRGB, ImGuiColorEditFlags.NoOptions)
    end

    -- Context menu: display and modify options (before defaults are applied)
    if bit32.band(flags, ImGuiColorEditFlags.NoOptions) == 0 then
        ImGui.ColorEditOptionsPopup(col, flags)
    end

    -- Read stored options
    if bit32.band(flags, ImGuiColorEditFlags.DisplayMask_) == 0 then
        flags = bit32.bor(flags, bit32.band(g.IO.ConfigColorEditFlags, ImGuiColorEditFlags.DisplayMask_))
    end
    if bit32.band(flags, ImGuiColorEditFlags.DataTypeMask_) == 0 then
        flags = bit32.bor(flags, bit32.band(g.IO.ConfigColorEditFlags, ImGuiColorEditFlags.DataTypeMask_))
    end
    if bit32.band(flags, ImGuiColorEditFlags.PickerMask_) == 0 then
        flags = bit32.bor(flags, bit32.band(g.IO.ConfigColorEditFlags, ImGuiColorEditFlags.PickerMask_))
    end
    if bit32.band(flags, ImGuiColorEditFlags.InputMask_) == 0 then
        flags = bit32.bor(flags, bit32.band(g.IO.ConfigColorEditFlags, ImGuiColorEditFlags.InputMask_))
    end
    flags = bit32.bor(flags, bit32.band(g.IO.ConfigColorEditFlags, bit32.bnot(bit32.bor(ImGuiColorEditFlags.DisplayMask_, ImGuiColorEditFlags.DataTypeMask_, ImGuiColorEditFlags.PickerMask_, ImGuiColorEditFlags.InputMask_))))
    IM_ASSERT(ImIsPowerOfTwo(bit32.band(flags, ImGuiColorEditFlags.DisplayMask_))) -- Check that only 1 is selected
    IM_ASSERT(ImIsPowerOfTwo(bit32.band(flags, ImGuiColorEditFlags.InputMask_)))   -- Check that only 1 is selected

    local alpha = bit32.band(flags, ImGuiColorEditFlags.NoAlpha) == 0
    local hdr = bit32.band(flags, ImGuiColorEditFlags.HDR) ~= 0
    local components = alpha and 4 or 3
    local w_button = (bit32.band(flags, ImGuiColorEditFlags.NoSmallPreview) ~= 0) and 0.0 or (square_sz + style.ItemInnerSpacing.x)
    local w_inputs = ImMax(w_full - w_button, 1.0)
    w_full = w_inputs + w_button

    -- Convert to the formats we need
    local f = { col[1], col[2], col[3], alpha and col[4] or 1.0 }
    if bit32.band(flags, ImGuiColorEditFlags.InputHSV) ~= 0 and bit32.band(flags, ImGuiColorEditFlags.DisplayRGB) ~= 0 then
        f[1], f[2], f[3] = ImGui.ColorConvertHSVtoRGB(f[1], f[2], f[3])
    elseif bit32.band(flags, ImGuiColorEditFlags.InputRGB) ~= 0 and bit32.band(flags, ImGuiColorEditFlags.DisplayHSV) ~= 0 then
        -- Hue is lost when converting from grayscale rgb (saturation=0). Restore it.
        f[1], f[2], f[3] = ImGui.ColorConvertRGBtoHSV(f[1], f[2], f[3])
        f[1], f[2], f[3] = ColorEditRestoreHS(col, f[1], f[2], f[3])
    end
    local i = { IM_F32_TO_INT8_UNBOUND(f[1]), IM_F32_TO_INT8_UNBOUND(f[2]), IM_F32_TO_INT8_UNBOUND(f[3]), IM_F32_TO_INT8_UNBOUND(f[4]) }

    local value_changed = false
    local value_changed_as_float = false

    local pos = ImVec2()
    ImVec2_Copy(pos, window.DC.CursorPos)
    local inputs_offset_x = (style.ColorButtonPosition == ImGuiDir.Left) and w_button or 0.0
    window.DC.CursorPos.x = pos.x + inputs_offset_x

    if bit32.band(flags, bit32.bor(ImGuiColorEditFlags.DisplayRGB, ImGuiColorEditFlags.DisplayHSV)) ~= 0 and bit32.band(flags, ImGuiColorEditFlags.NoInputs) == 0 then
        -- RGB/HSV 0..255 Sliders
        local w_items = w_inputs - style.ItemInnerSpacing.x * (components - 1)
        local w_per_component = IM_TRUNC(w_items / components)
        local draw_color_marker = bit32.band(flags, bit32.bor(ImGuiColorEditFlags.DisplayHSV, ImGuiColorEditFlags.NoColorMarkers)) == 0
        local hide_prefix = draw_color_marker or (w_per_component <= ImGui.CalcTextSize((bit32.band(flags, ImGuiColorEditFlags.Float) ~= 0) and "M:0.000" or "M:000").x)

        local fmt_idx
        if hide_prefix then
            fmt_idx = 1
        elseif bit32.band(flags, ImGuiColorEditFlags.DisplayHSV) ~= 0 then
            fmt_idx = 3
        else
            fmt_idx = 2
        end
        local drag_flags = draw_color_marker and ImGuiSliderFlags.ColorMarkers or ImGuiSliderFlags.None

        local prev_split = 0.0
        for n = 1, components do
            if n > 1 then
                ImGui.SameLine(0, style.ItemInnerSpacing.x)
            end
            local next_split = IM_TRUNC(w_items * n / components)
            ImGui.SetNextItemWidth(ImMax(next_split - prev_split, 1.0))
            prev_split = next_split
            if draw_color_marker then
                ImGui.SetNextItemColorMarker(GDefaultRgbaColorMarkers[n])
            end

            -- FIXME: When ImGuiColorEditFlags_HDR flag is passed HS values snap in weird ways when SV values go below 0.
            if bit32.band(flags, ImGuiColorEditFlags.Float) ~= 0 then
                local changed
                f[n], changed = ImGui.DragFloat(ids[n], f[n], 1.0 / 255.0, 0.0, hdr and 0.0 or 1.0, fmt_table_float[fmt_idx][n], drag_flags)
                value_changed = value_changed or changed
                value_changed_as_float = value_changed_as_float or value_changed
            else
                local changed
                i[n], changed = ImGui.DragInt(ids[n], i[n], 1.0, 0, hdr and 0 or 255, fmt_table_int[fmt_idx][n], drag_flags)
                value_changed = value_changed or changed
            end

            if bit32.band(flags, ImGuiColorEditFlags.NoOptions) == 0 then
                ImGui.OpenPopupOnItemClick("context", ImGuiPopupFlags.MouseButtonRight)
            end
        end
    elseif bit32.band(flags, ImGuiColorEditFlags.DisplayHex) ~= 0 and bit32.band(flags, ImGuiColorEditFlags.NoInputs) == 0 then
        -- RGB Hexadecimal Input
        -- TODO: resolve sprintf, sscanf requirement. currently this section creates a lot of temp tables and strings...
        local buf, buf_size = nil, 64
        if alpha then
            local str = ImFormatString("#%02X%02X%02X%02X", ImClamp(i[1], 0, 255), ImClamp(i[2], 0, 255), ImClamp(i[3], 0, 255), ImClamp(i[4], 0, 255))
            buf = { string.byte(str, 1, #str) }
            buf[#buf + 1] = 0
        else
            local str = ImFormatString("#%02X%02X%02X", ImClamp(i[1], 0, 255), ImClamp(i[2], 0, 255), ImClamp(i[3], 0, 255))
            buf = { string.byte(str, 1, #str) }
            buf[#buf + 1] = 0
        end
        ImGui.SetNextItemWidth(w_inputs)

        if ImGui.InputText("##Text", buf, buf_size, ImGuiInputTextFlags.CharsUppercase) then
            value_changed = true
            local p = 1
            while buf[p] == 35 or ImCharIsBlankA(buf[p]) do
                p = p + 1
            end
            i[1], i[2], i[3] = 0, 0, 0
            i[4] = 0xFF -- alpha default to 255 is not parsed by scanf (e.g. inputting #FFFFFF omitting alpha)

            local r
            if alpha then
                r = ImStd.sscanf(buf, p, "%02X%02X%02X%02X", i) -- Treat at unsigned (%X is unsigned)
            else
                r = ImStd.sscanf(buf, p, "%02X%02X%02X", i)
            end
            -- IM_UNUSED(r) -- Fixes C6031: Return value ignored: 'sscanf'.
        end

        if bit32.band(flags, ImGuiColorEditFlags.NoOptions) == 0 then
            ImGui.OpenPopupOnItemClick("context", ImGuiPopupFlags.MouseButtonRight)
        end
    end

    local picker_active_window = nil
    if bit32.band(flags, ImGuiColorEditFlags.NoSmallPreview) == 0 then
        local button_offset_x = (bit32.band(flags, ImGuiColorEditFlags.NoInputs) ~= 0 or style.ColorButtonPosition == ImGuiDir.Left) and 0.0 or (w_inputs + style.ItemInnerSpacing.x)
        ImVec2_Copy(window.DC.CursorPos, ImVec2(pos.x + button_offset_x, pos.y))

        local col_v4 = ImVec4(col[1], col[2], col[3], alpha and col[4] or 1.0)
        if ImGui.ColorButton("##ColorButton", col_v4, flags) then
            if bit32.band(flags, ImGuiColorEditFlags.NoPicker) == 0 then
                -- Store current color and open a picker
                ImVec4_Copy(g.ColorPickerRef, col_v4)
                ImGui.OpenPopup("picker")
                ImGui.SetNextWindowPos(g.LastItemData.Rect:GetBL() + ImVec2(0.0, style.ItemSpacing.y))
            end
        end
        if bit32.band(flags, ImGuiColorEditFlags.NoOptions) == 0 then
            ImGui.OpenPopupOnItemClick("context", ImGuiPopupFlags.MouseButtonRight)
        end

        if ImGui.BeginPopup("picker") then
            if g.CurrentWindow.BeginCount == 1 then
                picker_active_window = g.CurrentWindow
                if label ~= "" and label_display_end > 1 then
                    ImGui.TextEx(label, label_display_end)
                    ImGui.Spacing()
                end
                local picker_flags_to_forward = bit32.bor(ImGuiColorEditFlags.DataTypeMask_, ImGuiColorEditFlags.PickerMask_, ImGuiColorEditFlags.InputMask_, ImGuiColorEditFlags.HDR, ImGuiColorEditFlags.NoAlpha, ImGuiColorEditFlags.AlphaBar)
                local picker_flags = bit32.bor(bit32.band(flags_untouched, picker_flags_to_forward), ImGuiColorEditFlags.DisplayMask_, ImGuiColorEditFlags.NoLabel, ImGuiColorEditFlags.AlphaPreviewHalf)
                ImGui.SetNextItemWidth(square_sz * 12.0) -- Use 256 + bar sizes?
                value_changed = value_changed or ImGui.ColorPicker4("##picker", col, picker_flags, g.ColorPickerRef)
            end
            ImGui.EndPopup()
        end
    end

    if label ~= "" and label_display_end > 1 and bit32.band(flags, ImGuiColorEditFlags.NoLabel) == 0 then
        -- Position not necessarily next to last submitted button (e.g. if style.ColorButtonPosition == ImGuiDir_Left),
        -- but we need to use SameLine() to setup baseline correctly. Might want to refactor SameLine() to simplify this.
        ImGui.SameLine(0.0, style.ItemInnerSpacing.x)
        window.DC.CursorPos.x = pos.x + ((bit32.band(flags, ImGuiColorEditFlags.NoInputs) ~= 0) and w_button or (w_full + style.ItemInnerSpacing.x))
        ImGui.TextEx(label, label_display_end)
    end

    -- Convert back
    if value_changed and picker_active_window == nil then
        if not value_changed_as_float then
            for n = 1, 4 do
                f[n] = i[n] / 255.0
            end
        end
        if bit32.band(flags, ImGuiColorEditFlags.DisplayHSV) ~= 0 and bit32.band(flags, ImGuiColorEditFlags.InputRGB) ~= 0 then
            g.ColorEditSavedHue = f[1]
            g.ColorEditSavedSat = f[2]
            f[1], f[2], f[3] = ImGui.ColorConvertHSVtoRGB(f[1], f[2], f[3])
            g.ColorEditSavedID = g.ColorEditCurrentID
            g.ColorEditSavedColor = ImGui.ColorConvertFloat4ToU32(ImVec4(f[1], f[2], f[3], 0))
        end
        if bit32.band(flags, ImGuiColorEditFlags.DisplayRGB) ~= 0 and bit32.band(flags, ImGuiColorEditFlags.InputHSV) ~= 0 then
            f[1], f[2], f[3] = ImGui.ColorConvertRGBtoHSV(f[1], f[2], f[3])
        end

        col[1] = f[1]
        col[2] = f[2]
        col[3] = f[3]
        if alpha then
            col[4] = f[4]
        end
    end

    if set_current_color_edit_id then
        g.ColorEditCurrentID = 0
    end
    ImGui.PopID()
    ImGui.EndGroup()

    -- Drag and Drop Target
    -- TODO:

    -- When picker is being actively used, use its active id so IsItemActive() will function on ColorEdit4().
    if picker_active_window and g.ActiveId ~= 0 and g.ActiveIdWindow == picker_active_window then
        g.LastItemData.ID = g.ActiveId
    end

    if value_changed and g.LastItemData.ID ~= 0 then -- In case of ID collision, the second EndGroup() won't catch g.ActiveId
        ImGui.MarkItemEdited(g.LastItemData.ID)
    end

    return value_changed
end

end

--- @param label  string
--- @param col    [float, float, float]
--- @param flags? ImGuiColorEditFlags
function ImGui.ColorEdit3(label, col, flags)
    if flags == nil then flags = 0 end
    if flags == nil then flags = 0 end

    return ImGui.ColorEdit4(label, col, bit32.bor(flags, ImGuiColorEditFlags.NoAlpha))
end

-- `col` mutated in place, returns value_changed
function ImGui.ColorPicker3(label, col, flags)
    if flags == nil then flags = 0 end
    local col4 = { col[1], col[2], col[3], 1.0 }
    if not ImGui.ColorPicker4(label, col4, bit32.bor(flags or 0, ImGuiColorEditFlags.NoAlpha)) then
        return false
    end
    col[1] = col4[1]; col[2] = col4[2]; col[3] = col4[3]
    return true
end

-- This allowed passing 0 to set default, whereas NewFrame() will assert if one of missing. Abide to old logic.
function ImGui.SetColorEditOptions(flags)
    local g = GImGui
    local def = ImGuiColorEditFlags.DefaultOptions_
    for _, mask in ipairs({ ImGuiColorEditFlags.DisplayMask_, ImGuiColorEditFlags.DataTypeMask_, ImGuiColorEditFlags.PickerMask_, ImGuiColorEditFlags.InputMask_ }) do
        if bit32.band(flags, mask) == 0 then
            flags = bit32.bor(flags, bit32.band(def, mask))
        end
    end
    g.IO.ConfigColorEditFlags = flags
end

-- Helper for ColorPicker4()
--- @param draw_list ImDrawList
--- @param pos       ImVec2
--- @param half_sz   ImVec2
--- @param bar_w     float
--- @param alpha     float
local function RenderArrowsForVerticalBar(draw_list, pos, half_sz, bar_w, alpha)
    local alpha8 = IM_F32_TO_INT8_SAT(alpha)
    ImGui.RenderArrowPointingAt(draw_list, ImVec2(pos.x + half_sz.x + 1,         pos.y), ImVec2(half_sz.x + 2, half_sz.y + 1), ImGuiDir.Right, IM_COL32(0, 0, 0, alpha8))
    ImGui.RenderArrowPointingAt(draw_list, ImVec2(pos.x + half_sz.x,             pos.y), half_sz,                              ImGuiDir.Right, IM_COL32(255, 255, 255, alpha8))
    ImGui.RenderArrowPointingAt(draw_list, ImVec2(pos.x + bar_w - half_sz.x - 1, pos.y), ImVec2(half_sz.x + 2, half_sz.y + 1), ImGuiDir.Left,  IM_COL32(0, 0, 0, alpha8))
    ImGui.RenderArrowPointingAt(draw_list, ImVec2(pos.x + bar_w - half_sz.x,     pos.y), half_sz,                              ImGuiDir.Left,  IM_COL32(255, 255, 255, alpha8))
end

do --[[ColorPicker4]]

local backup_initial_col = {0, 0, 0, 0}

-- Note: ColorPicker4() only accesses 3 floats if ImGuiColorEditFlags.NoAlpha flag is set.
-- FIXME: we adjust the big color square height based on item width, which may cause a flickering feedback loop (if automatic height makes a vertical scrollbar appears, affecting automatic width..)
-- FIXME: this is trying to be aware of style.Alpha but not fully correct. Also, the color wheel will have overlapping glitches with (style.Alpha < 1.0)
--- @param label    string
--- @param col      float[]
--- @param flags    ImGuiColorEditFlags
--- @param ref_col? float[]
function ImGui.ColorPicker4(label, col, flags, ref_col)
    if flags == nil then flags = 0 end
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local draw_list = window.DrawList
    local g = GImGui
    local style = g.Style
    local io = g.IO

    local width = ImGui.CalcItemWidth()
    local is_readonly = bit32.band(bit32.bor(g.NextItemData.ItemFlagsSet, g.CurrentItemFlags), ImGuiItemFlags.ReadOnly) ~= 0
    g.NextItemData:ClearFlags()

    ImGui.PushID(label)
    local set_current_color_edit_id = (g.ColorEditCurrentID == 0)
    if set_current_color_edit_id then
        g.ColorEditCurrentID = window.IDStack:back()
    end
    ImGui.BeginGroup()

    if bit32.band(flags, ImGuiColorEditFlags.NoSidePreview) == 0 then
        flags = bit32.bor(flags, ImGuiColorEditFlags.NoSmallPreview)
    end

    -- Context menu: display and store options.
    if bit32.band(flags, ImGuiColorEditFlags.NoOptions) == 0 then
        ImGui.ColorPickerOptionsPopup(col, flags)
    end

    -- Read stored options
    if bit32.band(flags, ImGuiColorEditFlags.PickerMask_) == 0 then
        local picker_flags = bit32.band(g.IO.ConfigColorEditFlags, ImGuiColorEditFlags.PickerMask_)
        if picker_flags ~= 0 then
            flags = bit32.bor(flags, picker_flags)
        else
            flags = bit32.bor(flags, bit32.band(ImGuiColorEditFlags.DefaultOptions_, ImGuiColorEditFlags.PickerMask_))
        end
    end
    if bit32.band(flags, ImGuiColorEditFlags.InputMask_) == 0 then
        local input_flags = bit32.band(g.IO.ConfigColorEditFlags, ImGuiColorEditFlags.InputMask_)
        if input_flags ~= 0 then
            flags = bit32.bor(flags, input_flags)
        else
            flags = bit32.bor(flags, bit32.band(ImGuiColorEditFlags.DefaultOptions_, ImGuiColorEditFlags.InputMask_))
        end
    end
    IM_ASSERT(ImIsPowerOfTwo(bit32.band(flags, ImGuiColorEditFlags.PickerMask_))) -- Check that only 1 is selected
    IM_ASSERT(ImIsPowerOfTwo(bit32.band(flags, ImGuiColorEditFlags.InputMask_)))  -- Check that only 1 is selected
    if bit32.band(flags, ImGuiColorEditFlags.NoOptions) == 0 then
        flags = bit32.bor(flags, bit32.band(g.IO.ConfigColorEditFlags, ImGuiColorEditFlags.AlphaBar))
    end

    -- Setup
    local components = (bit32.band(flags, ImGuiColorEditFlags.NoAlpha) ~= 0) and 3 or 4
    local alpha_bar = (bit32.band(flags, ImGuiColorEditFlags.AlphaBar) ~= 0) and (bit32.band(flags, ImGuiColorEditFlags.NoAlpha) == 0)
    local picker_pos = ImVec2()
    ImVec2_Copy(picker_pos, window.DC.CursorPos)
    local square_sz = ImGui.GetFrameHeight()
    local bars_width = square_sz -- Arbitrary smallish width of Hue/Alpha picking bars
    local sv_picker_size = ImMax(bars_width * 1, width - (alpha_bar and 2 or 1) * (bars_width + style.ItemInnerSpacing.x)) -- Saturation/Value picking box
    local bar0_pos_x = picker_pos.x + sv_picker_size + style.ItemInnerSpacing.x
    local bar1_pos_x = bar0_pos_x + bars_width + style.ItemInnerSpacing.x
    local bars_triangles_half_sz = IM_TRUNC(bars_width * 0.20)

    backup_initial_col[1], backup_initial_col[2], backup_initial_col[3], backup_initial_col[4] = col[1], col[2], col[3], col[4]

    local wheel_thickness = sv_picker_size * 0.08
    local wheel_r_outer = sv_picker_size * 0.50
    local wheel_r_inner = wheel_r_outer - wheel_thickness
    local wheel_center = ImVec2(picker_pos.x + (sv_picker_size + bars_width) * 0.5, picker_pos.y + sv_picker_size * 0.5)

    -- Note: the triangle is displayed rotated with triangle_pa pointing to Hue, but most coordinates stays unrotated for logic.
    local triangle_rotate = bit32.band(flags, ImGuiColorEditFlags.PickerNoRotate) == 0
    local triangle_r = wheel_r_inner - math.floor(sv_picker_size * 0.027)
    local triangle_pa, triangle_pb, triangle_pc
    if triangle_rotate then triangle_pa = ImVec2(       triangle_r,                 0.0) else triangle_pa = ImVec2( triangle_r * 0.866, triangle_r * 0.5) end -- Hue point.
    if triangle_rotate then triangle_pb = ImVec2(triangle_r * -0.5, triangle_r * -0.866) else triangle_pb = ImVec2(                0.0,      -triangle_r) end -- Black point.
    if triangle_rotate then triangle_pc = ImVec2(triangle_r * -0.5, triangle_r *  0.866) else triangle_pc = ImVec2(triangle_r * -0.866, triangle_r * 0.5) end -- White point.

    local H = col[1]; local S = col[2]; local V = col[3]
    local R = col[1]; local G = col[2]; local B = col[3]
    if bit32.band(flags, ImGuiColorEditFlags.InputRGB) ~= 0 then
        -- Hue is lost when converting from grayscale rgb (saturation=0). Restore it.
        H, S, V = ImGui.ColorConvertRGBtoHSV(R, G, B)
        H, S, V = ColorEditRestoreHS(col, H, S, V)
    elseif bit32.band(flags, ImGuiColorEditFlags.InputHSV) ~= 0 then
        R, G, B = ImGui.ColorConvertHSVtoRGB(H, S, V)
    end

    local value_changed = false; local value_changed_h = false; local value_changed_sv = false

    ImGui.PushItemFlag(ImGuiItemFlags.NoNav, true)
    if bit32.band(flags, ImGuiColorEditFlags.PickerHueWheel) ~= 0 then
        -- Hue wheel + SV triangle logic
        ImGui.InvisibleButton("hsv", ImVec2(sv_picker_size + style.ItemInnerSpacing.x + bars_width, sv_picker_size))
        if ImGui.IsItemActive() and not is_readonly then
            local initial_off = g.IO.MouseClickedPos[0] - wheel_center
            local current_off = g.IO.MousePos - wheel_center
            local initial_dist2 = ImLengthSqr(initial_off)

            if initial_dist2 >= (wheel_r_inner - 1) * (wheel_r_inner - 1) and initial_dist2 <= (wheel_r_outer + 1) * (wheel_r_outer + 1) then
                -- Interactive with Hue wheel
                H = ImAtan2(current_off.y, current_off.x) / IM_PI * 0.5
                if H < 0.0 then
                    H = H + 1.0
                end
                value_changed = true
                value_changed_h = true
            end

            local cos_hue_angle = triangle_rotate and ImCos(-H * 2.0 * IM_PI) or 1.0
            local sin_hue_angle = triangle_rotate and ImSin(-H * 2.0 * IM_PI) or 0.0

            if ImStd.ImTriangleContainsPoint(triangle_pa, triangle_pb, triangle_pc, ImRotate(initial_off, cos_hue_angle, sin_hue_angle)) then
                -- Interacting with SV triangle
                local current_off_unrotated = ImRotate(current_off, cos_hue_angle, sin_hue_angle)
                if not ImStd.ImTriangleContainsPoint(triangle_pa, triangle_pb, triangle_pc, current_off_unrotated) then
                    current_off_unrotated = ImStd.ImTriangleClosestPoint(triangle_pa, triangle_pb, triangle_pc, current_off_unrotated)
                end
                local uu, vv, ww
                uu, vv, ww = ImStd.ImTriangleBarycentricCoords(triangle_pa, triangle_pb, triangle_pc, current_off_unrotated)
                V = ImClamp(1.0 - vv, 0.0001, 1.0)
                S = ImClamp(uu / V, 0.0001, 1.0)
                value_changed = true
                value_changed_sv = true
            end
        end

        if bit32.band(flags, ImGuiColorEditFlags.NoOptions) == 0 then
            ImGui.OpenPopupOnItemClick("context", ImGuiPopupFlags.MouseButtonRight)
        end
    elseif bit32.band(flags, ImGuiColorEditFlags.PickerHueBar) ~= 0 then
        -- SV rectangle logic
        ImGui.InvisibleButton("sv", ImVec2(sv_picker_size, sv_picker_size))
        if ImGui.IsItemActive() and not is_readonly then
            S = ImSaturate((io.MousePos.x - picker_pos.x) / ImMax(sv_picker_size - 1, 0.0001))
            V = 1.0 - ImSaturate((io.MousePos.y - picker_pos.y) / ImMax(sv_picker_size - 1, 0.0001))
            H = ColorEditRestoreH(col, H) -- Greatly reduces hue jitter and reset to 0 when hue == 255 and color is rapidly modified using SV square.
            value_changed = true
            value_changed_sv = true
        end

        if bit32.band(flags, ImGuiColorEditFlags.NoOptions) == 0 then
            ImGui.OpenPopupOnItemClick("context", ImGuiPopupFlags.MouseButtonRight)
        end

        -- Hue bar logic
        ImGui.SetCursorScreenPos(ImVec2(bar0_pos_x, picker_pos.y))
        ImGui.InvisibleButton("hue", ImVec2(bars_width, sv_picker_size))
        if ImGui.IsItemActive() and not is_readonly then
            H = ImSaturate((io.MousePos.y - picker_pos.y) / ImMax(sv_picker_size - 1, 0.0001))
            value_changed = true
            value_changed_h = true
        end
    end

    -- Alpha bar logic
    if alpha_bar then
        ImGui.SetCursorScreenPos(ImVec2(bar1_pos_x, picker_pos.y))
        ImGui.InvisibleButton("alpha", ImVec2(bars_width, sv_picker_size))
        if ImGui.IsItemActive() then
            col[4] = 1.0 - ImSaturate((io.MousePos.y - picker_pos.y) / ImMax(sv_picker_size - 1, 0.0001))
            value_changed = true
        end
    end
    ImGui.PopItemFlag() -- ImGuiItemFlags.NoNav

    if bit32.band(flags, ImGuiColorEditFlags.NoSidePreview) == 0 then
        ImGui.SameLine(0, style.ItemInnerSpacing.x)
        ImGui.BeginGroup()
    end

    if bit32.band(flags, ImGuiColorEditFlags.NoLabel) == 0 then
        local label_display_end = ImGui.FindRenderedTextEnd(label)
        if label ~= "" and label_display_end > 1 then
            if bit32.band(flags, ImGuiColorEditFlags.NoSidePreview) ~= 0 then
                ImGui.SameLine(0, style.ItemInnerSpacing.x)
            end
            ImGui.TextEx(label, label_display_end)
        end
    end

    if bit32.band(flags, ImGuiColorEditFlags.NoSidePreview) == 0 then
        ImGui.PushItemFlag(ImGuiItemFlags.NoNavDefaultFocus, true)
        local col_v4 = ImVec4(col[1], col[2], col[3], (bit32.band(flags, ImGuiColorEditFlags.NoAlpha) ~= 0) and 1.0 or col[4])

        if bit32.band(flags, ImGuiColorEditFlags.NoLabel) ~= 0 then
            ImGui.Text("Current")
        end

        local sub_flags_to_forward = bit32.bor(ImGuiColorEditFlags.InputMask_, ImGuiColorEditFlags.HDR, ImGuiColorEditFlags.AlphaMask_, ImGuiColorEditFlags.NoTooltip)

        ImGui.ColorButton("##current", col_v4, bit32.band(flags, sub_flags_to_forward), ImVec2(square_sz * 3, square_sz * 2))

        if ref_col ~= nil then
            ImGui.Text("Original")
            local ref_col_v4 = ImVec4(ref_col[1], ref_col[2], ref_col[3], (bit32.band(flags, ImGuiColorEditFlags.NoAlpha) ~= 0) and 1.0 or ref_col[4])
            if ImGui.ColorButton("##original", ref_col_v4, bit32.band(flags, sub_flags_to_forward), ImVec2(square_sz * 3, square_sz * 2)) then
                for i = 1, components do
                    col[i] = ref_col[i]
                end
                value_changed = true
            end
        end

        ImGui.PopItemFlag()
        ImGui.EndGroup()
    end

    -- Convert back color to RGB
    if value_changed_h or value_changed_sv then
        if bit32.band(flags, ImGuiColorEditFlags.InputRGB) ~= 0 then
            col[1], col[2], col[3] = ImGui.ColorConvertHSVtoRGB(H, S, V)  -- Lua 1-based indexing
            g.ColorEditSavedHue = H
            g.ColorEditSavedSat = S
            g.ColorEditSavedID = g.ColorEditCurrentID
            g.ColorEditSavedColor = ImGui.ColorConvertFloat4ToU32(ImVec4(col[1], col[2], col[3], 0))
        elseif bit32.band(flags, ImGuiColorEditFlags.InputHSV) ~= 0 then
            col[1] = H
            col[2] = S
            col[3] = V
        end
    end

    -- R,G,B and H,S,V slider color editor
    local value_changed_fix_hue_wrap = false
    if bit32.band(flags, ImGuiColorEditFlags.NoInputs) == 0 then
        ImGui.PushItemWidth((alpha_bar and bar1_pos_x or bar0_pos_x) + bars_width - picker_pos.x)

        local sub_flags_to_forward = bit32.bor(ImGuiColorEditFlags.DataTypeMask_, ImGuiColorEditFlags.InputMask_, ImGuiColorEditFlags.HDR, ImGuiColorEditFlags.AlphaMask_, ImGuiColorEditFlags.NoOptions, ImGuiColorEditFlags.NoTooltip, ImGuiColorEditFlags.NoSmallPreview)
        local sub_flags = bit32.bor(bit32.band(flags, sub_flags_to_forward), ImGuiColorEditFlags.NoPicker)

        if bit32.band(flags, ImGuiColorEditFlags.DisplayRGB) ~= 0 or bit32.band(flags, ImGuiColorEditFlags.DisplayMask_) == 0 then
            if ImGui.ColorEdit4("##rgb", col, bit32.bor(sub_flags, ImGuiColorEditFlags.DisplayRGB)) then
                -- FIXME: Hackily differentiating using the DragInt (ActiveId != 0 && !ActiveIdAllowOverlap) vs. using the InputText or DropTarget.
                -- For the later we don't want to run the hue-wrap canceling code. If you are well versed in HSV picker please provide your input! (See #2050)
                value_changed_fix_hue_wrap = (g.ActiveId ~= 0 and not g.ActiveIdAllowOverlap)
                value_changed = true
            end
        end

        if bit32.band(flags, ImGuiColorEditFlags.DisplayHSV) ~= 0 or bit32.band(flags, ImGuiColorEditFlags.DisplayMask_) == 0 then
            if ImGui.ColorEdit4("##hsv", col, bit32.bor(sub_flags, ImGuiColorEditFlags.DisplayHSV)) then
                value_changed = true
            end
        end

        if bit32.band(flags, ImGuiColorEditFlags.DisplayHex) ~= 0 or bit32.band(flags, ImGuiColorEditFlags.DisplayMask_) == 0 then
            if ImGui.ColorEdit4("##hex", col, bit32.bor(sub_flags, ImGuiColorEditFlags.DisplayHex)) then
                value_changed = true
            end
        end

        ImGui.PopItemWidth()
    end

    -- Try to cancel hue wrap (after ColorEdit4 call), if any
    if value_changed_fix_hue_wrap and bit32.band(flags, ImGuiColorEditFlags.InputRGB) ~= 0 then
        local new_H, new_S, new_V = ImGui.ColorConvertRGBtoHSV(col[1], col[2], col[3])  -- Lua 1-based indexing

        if new_H <= 0 and H > 0 then
            if new_V <= 0 and V ~= new_V then
                col[1], col[2], col[3] = ImGui.ColorConvertHSVtoRGB(H, S, (new_V <= 0) and (V * 0.5) or new_V)
            elseif new_S <= 0 then
                col[1], col[2], col[3] = ImGui.ColorConvertHSVtoRGB(H, (new_S <= 0) and (S * 0.5) or new_S, new_V)
            end
        end
    end

    if value_changed then
        if bit32.band(flags, ImGuiColorEditFlags.InputRGB) ~= 0 then
            R = col[1]
            G = col[2]
            B = col[3]
            H, S, V = ImGui.ColorConvertRGBtoHSV(R, G, B)
            H, S, V = ColorEditRestoreHS(col, H, S, V) -- Fix local Hue as display below will use it immediately.
        elseif bit32.band(flags, ImGuiColorEditFlags.InputHSV) ~= 0 then
            H = col[1]
            S = col[2]
            V = col[3]
            R, G, B = ImGui.ColorConvertHSVtoRGB(H, S, V)
        end
    end

    local style_alpha8 = IM_F32_TO_INT8_SAT(style.Alpha)
    local col_black = IM_COL32(0, 0, 0, style_alpha8)
    local col_white = IM_COL32(255, 255, 255, style_alpha8)
    local col_midgrey = IM_COL32(128, 128, 128, style_alpha8)
    local col_hues = { IM_COL32(255, 0, 0, style_alpha8), IM_COL32(255, 255, 0, style_alpha8), IM_COL32(0, 255, 0, style_alpha8), IM_COL32(0, 255, 255, style_alpha8), IM_COL32(0, 0, 255, style_alpha8), IM_COL32(255, 0, 255, style_alpha8), IM_COL32(255, 0, 0, style_alpha8) }

    local hue_color_f = ImVec4(1, 1, 1, style.Alpha)
    hue_color_f.x, hue_color_f.y, hue_color_f.z = ImGui.ColorConvertHSVtoRGB(H, 1, 1)
    local hue_color32 = ImGui.ColorConvertFloat4ToU32(hue_color_f)
    local user_col32_striped_of_alpha = ImGui.ColorConvertFloat4ToU32(ImVec4(R, G, B, style.Alpha)) -- Important: this is still including the main rendering/style alpha!!

    local sv_cursor_pos = ImVec2()

    if bit32.band(flags, ImGuiColorEditFlags.PickerHueWheel) ~= 0 then
        -- Render Hue Wheel
        local aeps = 0.5 / wheel_r_outer -- Half a pixel arc length in radians (2pi cancels out).
        local segment_per_arc = ImMax(4, math.floor(wheel_r_outer / 12))

        for n = 1, 6 do
            local a0 = (n - 1) / 6.0 * 2.0 * IM_PI - aeps
            local a1 = n / 6.0 * 2.0 * IM_PI + aeps
            local vert_start_idx = draw_list.VtxBuffer.Size + 1

            draw_list:PathArcTo(wheel_center, (wheel_r_inner + wheel_r_outer) * 0.5, a0, a1, segment_per_arc)
            draw_list:PathStroke(col_white, wheel_thickness)

            local vert_end_idx = draw_list.VtxBuffer.Size + 1

            -- Paint colors over existing vertices
            local gradient_p0 = ImVec2(wheel_center.x + ImCos(a0) * wheel_r_inner, wheel_center.y + ImSin(a0) * wheel_r_inner)
            local gradient_p1 = ImVec2(wheel_center.x + ImCos(a1) * wheel_r_inner, wheel_center.y + ImSin(a1) * wheel_r_inner)
            ImGui.ShadeVertsLinearColorGradientKeepAlpha(draw_list, vert_start_idx, vert_end_idx, gradient_p0, gradient_p1, col_hues[n], col_hues[n + 1])
        end

        -- Render Cursor + preview on Hue Wheel
        local cos_hue_angle = ImCos(H * 2.0 * IM_PI)
        local sin_hue_angle = ImSin(H * 2.0 * IM_PI)

        local hue_cursor_pos = ImVec2(wheel_center.x + cos_hue_angle * (wheel_r_inner + wheel_r_outer) * 0.5, wheel_center.y + sin_hue_angle * (wheel_r_inner + wheel_r_outer) * 0.5)

        local hue_cursor_rad = value_changed_h and (wheel_thickness * 0.65) or (wheel_thickness * 0.55)
        local hue_cursor_segments = draw_list:_CalcCircleAutoSegmentCount(hue_cursor_rad) -- Lock segment count so the +1 one matches others.

        draw_list:AddCircleFilled(hue_cursor_pos, hue_cursor_rad, hue_color32, hue_cursor_segments)
        draw_list:AddCircle(hue_cursor_pos, hue_cursor_rad + 1, col_midgrey, hue_cursor_segments)
        draw_list:AddCircle(hue_cursor_pos, hue_cursor_rad, col_white, hue_cursor_segments)

        if triangle_rotate == false then
            cos_hue_angle = 1.0
            sin_hue_angle = 0.0
        end

        -- Render SV triangle (rotated according to hue)
        local tra = wheel_center + ImRotate(triangle_pa, cos_hue_angle, sin_hue_angle)
        local trb = wheel_center + ImRotate(triangle_pb, cos_hue_angle, sin_hue_angle)
        local trc = wheel_center + ImRotate(triangle_pc, cos_hue_angle, sin_hue_angle)

        local uv_white = ImGui.GetFontTexUvWhitePixel()
        draw_list:PrimReserve(3, 3)
        draw_list:PrimVtx(tra, uv_white, hue_color32)
        draw_list:PrimVtx(trb, uv_white, col_black)
        draw_list:PrimVtx(trc, uv_white, col_white)
        draw_list:AddTriangle(tra, trb, trc, col_midgrey, 1.5)

        sv_cursor_pos = ImLerp(ImLerp(trc, tra, ImSaturate(S)), trb, ImSaturate(1 - V))
    elseif bit32.band(flags, ImGuiColorEditFlags.PickerHueBar) ~= 0 then
        -- Render SV Square
        draw_list:AddRectFilledMultiColor(picker_pos, picker_pos + ImVec2(sv_picker_size, sv_picker_size), col_white, hue_color32, hue_color32, col_white)
        draw_list:AddRectFilledMultiColor(picker_pos, picker_pos + ImVec2(sv_picker_size, sv_picker_size), 0, 0, col_black, col_black)
        ImGui.RenderFrameBorder(picker_pos, picker_pos + ImVec2(sv_picker_size, sv_picker_size), 0.0)

        sv_cursor_pos.x = ImClamp(IM_ROUND(picker_pos.x + ImSaturate(S) * sv_picker_size), picker_pos.x + 2, picker_pos.x + sv_picker_size - 2) -- Sneakily prevent the circle to stick out too much
        sv_cursor_pos.y = ImClamp(IM_ROUND(picker_pos.y + ImSaturate(1 - V) * sv_picker_size), picker_pos.y + 2, picker_pos.y + sv_picker_size - 2)

        -- Render Hue Bar
        for i = 1, 6 do
            draw_list:AddRectFilledMultiColor(ImVec2(bar0_pos_x, picker_pos.y + (i - 1) * (sv_picker_size / 6)), ImVec2(bar0_pos_x + bars_width, picker_pos.y + i * (sv_picker_size / 6)), col_hues[i], col_hues[i], col_hues[i + 1], col_hues[i + 1])
        end

        local bar0_line_y = IM_ROUND(picker_pos.y + H * sv_picker_size)
        ImGui.RenderFrameBorder(ImVec2(bar0_pos_x, picker_pos.y), ImVec2(bar0_pos_x + bars_width, picker_pos.y + sv_picker_size), 0.0)
        RenderArrowsForVerticalBar(draw_list, ImVec2(bar0_pos_x - 1, bar0_line_y), ImVec2(bars_triangles_half_sz + 1, bars_triangles_half_sz), bars_width + 2.0, style.Alpha)
    end

    -- Render cursor/preview circle (clamp S/V within 0..1 range because floating points colors may lead HSV values to be out of range)
    local sv_cursor_rad = value_changed_sv and (wheel_thickness * 0.55) or (wheel_thickness * 0.40)
    local sv_cursor_segments = draw_list:_CalcCircleAutoSegmentCount(sv_cursor_rad) -- Lock segment count so the +1 one matches others.
    draw_list:AddCircleFilled(sv_cursor_pos, sv_cursor_rad, user_col32_striped_of_alpha, sv_cursor_segments)
    draw_list:AddCircle(sv_cursor_pos, sv_cursor_rad + 1, col_midgrey, sv_cursor_segments)
    draw_list:AddCircle(sv_cursor_pos, sv_cursor_rad, col_white, sv_cursor_segments)

    -- Render alpha bar
    if alpha_bar then
        local alpha = ImSaturate(col[4])
        local bar1_bb = ImRect(bar1_pos_x, picker_pos.y, bar1_pos_x + bars_width, picker_pos.y + sv_picker_size)
        ImGui.RenderColorRectWithAlphaCheckerboard(draw_list, bar1_bb.Min, bar1_bb.Max, 0, bar1_bb:GetWidth() / 2.0, ImVec2(0.0, 0.0))
        draw_list:AddRectFilledMultiColor(bar1_bb.Min, bar1_bb.Max, user_col32_striped_of_alpha, user_col32_striped_of_alpha, bit32.band(user_col32_striped_of_alpha, bit32.bnot(IM_COL32_A_MASK)), bit32.band(user_col32_striped_of_alpha, bit32.bnot(IM_COL32_A_MASK)))

        local bar1_line_y = IM_ROUND(picker_pos.y + (1.0 - alpha) * sv_picker_size)
        ImGui.RenderFrameBorder(bar1_bb.Min, bar1_bb.Max, 0.0)
        RenderArrowsForVerticalBar(draw_list, ImVec2(bar1_pos_x - 1, bar1_line_y), ImVec2(bars_triangles_half_sz + 1, bars_triangles_half_sz), bars_width + 2.0, style.Alpha)
    end

    ImGui.EndGroup()

    if value_changed then
        for i = 1, components do
            if backup_initial_col[i] ~= col[i] then
                break
            end
            if i == components then
                value_changed = false
            end
        end
    end

    if value_changed and g.LastItemData.ID ~= 0 then -- In case of ID collision, the second EndGroup() won't catch g.ActiveId
        ImGui.MarkItemEdited(g.LastItemData.ID)
    end

    if set_current_color_edit_id then
        g.ColorEditCurrentID = 0
    end

    ImGui.PopID()

    return value_changed
end

end

-- A little color square. Return true when clicked.
-- FIXME: May want to display/ignore the alpha component in the color display? Yet show it in the tooltip.
-- 'desc_id' is not called 'label' because we don't display it next to the button, but only in the tooltip.
-- Note that 'col' may be encoded in HSV if ImGuiColorEditFlags.InputHSV is set.
--- @param desc_id   string
--- @param col       ImVec4
--- @param flags?    ImGuiColorEditFlags
--- @param size_arg? ImVec2

function ImGui.ColorButton(desc_id, col, flags, size_arg)
    if flags    == nil then flags    = 0            end
    if size_arg == nil then size_arg = ImVec2(0, 0) end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local id = window:GetID(desc_id)
    local default_size = ImGui.GetFrameHeight()
    local size = ImVec2(size_arg.x == 0.0 and default_size or size_arg.x, size_arg.y == 0.0 and default_size or size_arg.y)
    local bb = ImRect(window.DC.CursorPos, window.DC.CursorPos + size)
    ImGui.ItemSize(bb, (size.y >= default_size) and g.Style.FramePadding.y or 0.0)
    if not ImGui.ItemAdd(bb, id) then
        return false
    end

    local pressed, hovered, _ = ImGui.ButtonBehavior(bb, id)

    if bit32.band(flags, bit32.bor(ImGuiColorEditFlags.NoAlpha, ImGuiColorEditFlags.AlphaOpaque)) ~= 0 then
        flags = bit32.band(flags, bit32.bnot(bit32.bor(ImGuiColorEditFlags.AlphaNoBg, ImGuiColorEditFlags.AlphaPreviewHalf)))
    end

    local col_rgb = ImVec4(col.x, col.y, col.z, col.w)
    if bit32.band(flags, ImGuiColorEditFlags.InputHSV) ~= 0 then
        col_rgb.x, col_rgb.y, col_rgb.z = ImGui.ColorConvertHSVtoRGB(col_rgb.x, col_rgb.y, col_rgb.z)
    end

    local col_rgb_without_alpha = ImVec4(col_rgb.x, col_rgb.y, col_rgb.z, 1.0)
    local grid_step = ImMin(size.x, size.y) / 2.99
    local rounding = ImMin(g.Style.FrameRounding, grid_step * 0.5)
    local bb_inner = ImRect()
    ImRect_Copy(bb_inner, bb)
    local off = 0.0
    if bit32.band(flags, ImGuiColorEditFlags.NoBorder) == 0 then
        off = -0.75
        bb_inner:Expand(off)
    end
    if bit32.band(flags, ImGuiColorEditFlags.AlphaPreviewHalf) ~= 0 and col_rgb.w < 1.0 then
        local mid_x = IM_ROUND((bb_inner.Min.x + bb_inner.Max.x) * 0.5)
        if bit32.band(flags, ImGuiColorEditFlags.AlphaNoBg) == 0 then
            ImGui.RenderColorRectWithAlphaCheckerboard(window.DrawList, ImVec2(bb_inner.Min.x + grid_step, bb_inner.Min.y), bb_inner.Max, ImGui.GetColorU32(col_rgb), grid_step, ImVec2(-grid_step + off, off), rounding, ImDrawFlags.RoundCornersRight)
        else
            window.DrawList:AddRectFilled(ImVec2(bb_inner.Min.x + grid_step, bb_inner.Min.y), bb_inner.Max, ImGui.GetColorU32(col_rgb), rounding, ImDrawFlags.RoundCornersRight)
        end
        window.DrawList:AddRectFilled(bb_inner.Min, ImVec2(mid_x, bb_inner.Max.y), ImGui.GetColorU32(col_rgb_without_alpha), rounding, ImDrawFlags.RoundCornersLeft)
    else
        -- Because GetColorU32() multiplies by the global style Alpha and we don't want to display a checkerboard if the source code had no alpha
        local col_source = (bit32.band(flags, ImGuiColorEditFlags.AlphaOpaque) ~= 0) and col_rgb_without_alpha or col_rgb
        if col_source.w < 1.0 and bit32.band(flags, ImGuiColorEditFlags.AlphaNoBg) == 0 then
            ImGui.RenderColorRectWithAlphaCheckerboard(window.DrawList, bb_inner.Min, bb_inner.Max, ImGui.GetColorU32(col_source), grid_step, ImVec2(off, off), rounding)
        else
            window.DrawList:AddRectFilled(bb_inner.Min, bb_inner.Max, ImGui.GetColorU32(col_source), rounding)
        end
    end
    ImGui.RenderNavCursor(bb, id)
    if bit32.band(flags, ImGuiColorEditFlags.NoBorder) == 0 then
        if g.Style.FrameBorderSize > 0.0 then
            ImGui.RenderFrameBorder(bb.Min, bb.Max, rounding)
        else
            window.DrawList:AddRect(bb.Min, bb.Max, ImGui.GetColorU32(ImGuiCol.FrameBg), rounding) -- Color buttons are often in need of some sort of border
        end
    end

    -- Drag and Drop Source
    -- NB: The ActiveId test is merely an optional micro-optimization, BeginDragDropSource() does the same test.
    -- if g.ActiveId == id and bit32.band(flags, ImGuiColorEditFlags.NoDragDrop) == 0 and ImGui.BeginDragDropSource() then
    --     if bit32.band(flags, ImGuiColorEditFlags.NoAlpha) ~= 0 then
    --         ImGui.SetDragDropPayload(IMGUI_PAYLOAD_TYPE_COLOR_3F, col_rgb, ImGuiCond.Once)
    --     else
    --         ImGui.SetDragDropPayload(IMGUI_PAYLOAD_TYPE_COLOR_4F, col_rgb, ImGuiCond.Once)
    --     end
    --     ImGui.ColorButton(desc_id, col, flags)
    --     ImGui.SameLine()
    --     ImGui.TextEx("Color")
    --     ImGui.EndDragDropSource()
    -- end

    -- Tooltip
    if bit32.band(flags, ImGuiColorEditFlags.NoTooltip) == 0 and hovered and ImGui.IsItemHovered(ImGuiHoveredFlags.ForTooltip) then
        ImGui.ColorTooltip(desc_id, col, bit32.band(flags, bit32.bor(ImGuiColorEditFlags.InputMask_, ImGuiColorEditFlags.AlphaMask_)))
    end

    return pressed
end

-- Note: only access 3 floats if ImGuiColorEditFlags.NoAlpha flag is set.
--- @param text? string
--- @param col   ImVec4
--- @param flags ImGuiColorEditFlags
function ImGui.ColorTooltip(text, col, flags)
    local g = GImGui

    if not ImGui.BeginTooltipEx(ImGuiTooltipFlags.OverridePrevious, ImGuiWindowFlags.None) then
        return
    end

    local text_end = text and ImGui.FindRenderedTextEnd(text, nil) or 1
    if text_end > 1 then
        --- @cast text string
        ImGui.TextEx(text, text_end)
        ImGui.Separator()
    end

    local sz = ImVec2(g.FontSize * 3 + g.Style.FramePadding.y * 2, g.FontSize * 3 + g.Style.FramePadding.y * 2)
    local cf = ImVec4(col.x, col.y, col.z, (bit32.band(flags, ImGuiColorEditFlags.NoAlpha) ~= 0) and 1.0 or col.w)
    local cr = IM_F32_TO_INT8_SAT(col.x)
    local cg = IM_F32_TO_INT8_SAT(col.y)
    local cb = IM_F32_TO_INT8_SAT(col.z)
    local ca = (bit32.band(flags, ImGuiColorEditFlags.NoAlpha) ~= 0) and 255 or IM_F32_TO_INT8_SAT(col.w)

    local flags_to_forward = bit32.bor(ImGuiColorEditFlags.InputMask_, ImGuiColorEditFlags.AlphaMask_)
    ImGui.ColorButton("##preview", cf, bit32.bor(bit32.band(flags, flags_to_forward), ImGuiColorEditFlags.NoTooltip), sz)
    ImGui.SameLine()

    if bit32.band(flags, ImGuiColorEditFlags.InputRGB) ~= 0 or bit32.band(flags, ImGuiColorEditFlags.InputMask_) == 0 then
        if bit32.band(flags, ImGuiColorEditFlags.NoAlpha) ~= 0 then
            ImGui.Text("#%02X%02X%02X\nR: %d, G: %d, B: %d\n(%.3f, %.3f, %.3f)", cr, cg, cb, cr, cg, cb, col.x, col.y, col.z)
        else
            ImGui.Text("#%02X%02X%02X%02X\nR:%d, G:%d, B:%d, A:%d\n(%.3f, %.3f, %.3f, %.3f)", cr, cg, cb, ca, cr, cg, cb, ca, col.x, col.y, col.z, col.w)
        end
    elseif bit32.band(flags, ImGuiColorEditFlags.InputHSV) ~= 0 then
        if bit32.band(flags, ImGuiColorEditFlags.NoAlpha) ~= 0 then
            ImGui.Text("H: %.3f, S: %.3f, V: %.3f", col.x, col.y, col.z)
        else
            ImGui.Text("H: %.3f, S: %.3f, V: %.3f, A: %.3f", col.x, col.y, col.z, col.w)
        end
    end

    ImGui.EndTooltip()
end

--- @param col   float[]
--- @param flags ImGuiColorEditFlags
function ImGui.ColorEditOptionsPopup(col, flags)
    local allow_opt_inputs = bit32.band(flags, ImGuiColorEditFlags.DisplayMask_) == 0
    local allow_opt_datatype = bit32.band(flags, ImGuiColorEditFlags.DataTypeMask_) == 0

    if (not allow_opt_inputs and not allow_opt_datatype) or not ImGui.BeginPopup("context") then
        return
    end

    local g = GImGui
    ImGui.PushItemFlag(ImGuiItemFlags.NoMarkEdited, true)
    local opts = g.IO.ConfigColorEditFlags
    if allow_opt_inputs then
        if ImGui.RadioButtonEx("RGB", bit32.band(opts, ImGuiColorEditFlags.DisplayRGB) ~= 0) then
            opts = bit32.bor(bit32.band(opts, bit32.bnot(ImGuiColorEditFlags.DisplayMask_)), ImGuiColorEditFlags.DisplayRGB)
        end
        if ImGui.RadioButtonEx("HSV", bit32.band(opts, ImGuiColorEditFlags.DisplayHSV) ~= 0) then
            opts = bit32.bor(bit32.band(opts, bit32.bnot(ImGuiColorEditFlags.DisplayMask_)), ImGuiColorEditFlags.DisplayHSV)
        end
        if ImGui.RadioButtonEx("Hex", bit32.band(opts, ImGuiColorEditFlags.DisplayHex) ~= 0) then
            opts = bit32.bor(bit32.band(opts, bit32.bnot(ImGuiColorEditFlags.DisplayMask_)), ImGuiColorEditFlags.DisplayHex)
        end
    end
    if allow_opt_datatype then
        if allow_opt_inputs then ImGui.Separator() end
        if ImGui.RadioButtonEx("0..255", bit32.band(opts, ImGuiColorEditFlags.Uint8) ~= 0) then
            opts = bit32.bor(bit32.band(opts, bit32.bnot(ImGuiColorEditFlags.DataTypeMask_)), ImGuiColorEditFlags.Uint8)
        end
        if ImGui.RadioButtonEx("0.00..1.00", bit32.band(opts, ImGuiColorEditFlags.Float) ~= 0) then
            opts = bit32.bor(bit32.band(opts, bit32.bnot(ImGuiColorEditFlags.DataTypeMask_)), ImGuiColorEditFlags.Float)
        end
    end

    if allow_opt_inputs or allow_opt_datatype then
        ImGui.Separator()
    end
    if ImGui.Button("Copy as..", ImVec2(-1, 0)) then
        ImGui.OpenPopup("Copy")
    end
    if ImGui.BeginPopup("Copy") then
        local cr = IM_F32_TO_INT8_SAT(col[1])
        local cg = IM_F32_TO_INT8_SAT(col[2])
        local cb = IM_F32_TO_INT8_SAT(col[3])
        local ca = (bit32.band(flags, ImGuiColorEditFlags.NoAlpha) ~= 0) and 255 or IM_F32_TO_INT8_SAT(col[4])

        local buf1 = ImFormatString("(%.3ff, %.3ff, %.3ff, %.3ff)", col[1], col[2], col[3], (bit32.band(flags, ImGuiColorEditFlags.NoAlpha) ~= 0) and 1.0 or col[4])
        if ImGui.Selectable(buf1) then
            ImGui.SetClipboardText(buf1)
        end

        local buf2 = ImFormatString("(%d,%d,%d,%d)", cr, cg, cb, ca)
        if ImGui.Selectable(buf2) then
            ImGui.SetClipboardText(buf2)
        end

        local buf3 = ImFormatString("#%02X%02X%02X", cr, cg, cb)
        if ImGui.Selectable(buf3) then
            ImGui.SetClipboardText(buf3)
        end

        if bit32.band(flags, ImGuiColorEditFlags.NoAlpha) == 0 then
            local buf4 = ImFormatString("#%02X%02X%02X%02X", cr, cg, cb, ca)
            if ImGui.Selectable(buf4) then
                ImGui.SetClipboardText(buf4)
            end
        end

        ImGui.EndPopup()
    end

    g.IO.ConfigColorEditFlags = opts
    ImGui.PopItemFlag()
    ImGui.EndPopup()
end

--- @param ref_col float[]
--- @param flags   ImGuiColorEditFlags
function ImGui.ColorPickerOptionsPopup(ref_col, flags)
    local allow_opt_picker = bit32.band(flags, ImGuiColorEditFlags.PickerMask_) == 0
    local allow_opt_alpha_bar = (bit32.band(flags, ImGuiColorEditFlags.NoAlpha) == 0) and (bit32.band(flags, ImGuiColorEditFlags.AlphaBar) == 0)

    if (not allow_opt_picker and not allow_opt_alpha_bar) or not ImGui.BeginPopup("context") then
        return
    end

    local g = GImGui
    ImGui.PushItemFlag(ImGuiItemFlags.NoMarkEdited, true)
    if allow_opt_picker then
        local picker_size = ImVec2(g.FontSize * 8, ImMax(g.FontSize * 8 - (ImGui.GetFrameHeight() + g.Style.ItemInnerSpacing.x), 1.0)) -- FIXME: Picker size copied from main picker function
        ImGui.PushItemWidth(picker_size.x)
        for picker_type = 0, 1 do
            -- Draw small/thumbnail version of each picker type (over an invisible button for selection)
            if picker_type > 0 then
                ImGui.Separator()
            end
            ImGui.PushID(picker_type)
            local picker_flags = bit32.bor(ImGuiColorEditFlags.NoInputs, ImGuiColorEditFlags.NoOptions, ImGuiColorEditFlags.NoLabel, ImGuiColorEditFlags.NoSidePreview, bit32.band(flags, ImGuiColorEditFlags.NoAlpha))
            if picker_type == 0 then
                picker_flags = bit32.bor(picker_flags, ImGuiColorEditFlags.PickerHueBar)
            end
            if picker_type == 1 then
                picker_flags = bit32.bor(picker_flags, ImGuiColorEditFlags.PickerHueWheel)
            end
            local backup_pos = ImGui.GetCursorScreenPos()
            if ImGui.Selectable("##selectable", false, 0, picker_size) then -- By default, Selectable() is closing popup
                g.IO.ConfigColorEditFlags = bit32.bor(bit32.band(g.IO.ConfigColorEditFlags, bit32.bnot(ImGuiColorEditFlags.PickerMask_)), bit32.band(picker_flags, ImGuiColorEditFlags.PickerMask_))
            end
            ImGui.SetCursorScreenPos(backup_pos)
            local previewing_ref_col = ImVec4()
            for i = 1, (bit32.band(picker_flags, ImGuiColorEditFlags.NoAlpha) ~= 0 and 3 or 4) do
                previewing_ref_col[i] = ref_col[i]
            end
            ImGui.ColorPicker4("##previewing_picker", previewing_ref_col, picker_flags)
            ImGui.PopID()
        end
        ImGui.PopItemWidth()
    end
    if allow_opt_alpha_bar then
        if allow_opt_picker then
            ImGui.Separator()
        end
        _, g.IO.ConfigColorEditFlags = ImGui.CheckboxFlags("Alpha Bar", g.IO.ConfigColorEditFlags, ImGuiColorEditFlags.AlphaBar)
    end
    ImGui.PopItemFlag()
    ImGui.EndPopup()
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: TreeNode, CollapsingHeader, etc.
-------------------------------------------------------------------------------
-- - TreeNode()
-- - TreeNodeV()
-- - TreeNodeEx()
-- - TreeNodeExV()
-- - TreeNodeStoreStackData() [Internal]
-- - TreeNodeBehavior() [Internal]
-- - TreePush()
-- - TreePop()
-- - GetTreeNodeToLabelSpacing()
-- - SetNextItemOpen()
-- - CollapsingHeader()
-------------------------------------------------------------------------------

-- va_list variants: identical in Lua (varargs)
ImGui.TextColoredV = function(...) return ImGui.TextColored(...) end
ImGui.TextDisabledV = function(...) return ImGui.TextDisabled(...) end
ImGui.TextWrappedV = function(...) return ImGui.TextWrapped(...) end
ImGui.TextAlignedV = function(...) return ImGui.TextAligned(...) end
ImGui.LabelTextV = function(...) return ImGui.LabelText(...) end
ImGui.BulletTextV = function(...) return ImGui.BulletText(...) end

--- @param data_type ImGuiDataType
--- @param v         number
function ImGui.SetNextItemRefVal(data_type, v)
    local g = GImGui
    g.NextItemData.HasFlags = bit32.bor(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasRefVal)
    g.NextItemData.RefVal = v
end

-- Overloads: TreeNode(label) / TreeNode(str_id, fmt, ...)
--- @param label string

function ImGui.TreeNode(label, fmt, ...)
    if fmt ~= nil then
        return ImGui.TreeNodeEx(label, 0, fmt, ...)
    end
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end
    local id = window:GetID(label)
    return ImGui.TreeNodeBehavior(id, ImGuiTreeNodeFlags.None, label, nil)
end

function ImGui.TreeNodeV(str_id, fmt, ...)
    return ImGui.TreeNodeExV(str_id, 0, fmt, ...)
end

-- Overloads: TreeNodeEx(label, flags) / TreeNodeEx(str_id, flags, fmt, ...)
--- @param label  string
--- @param flags? ImGuiTreeNodeFlags
function ImGui.TreeNodeEx(label, flags, fmt, ...)
    if flags == nil then flags = 0 end
    if fmt ~= nil then
        return ImGui.TreeNodeExV(label, flags, fmt, ...)
    end
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end
    local id = window:GetID(label)
    return ImGui.TreeNodeBehavior(id, flags, label, nil)
end

--- @param str_id string|ImGuiID
function ImGui.TreeNodeExV(str_id, flags, fmt, ...)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end
    local id = window:GetID(str_id)
    local label = (select("#", ...) > 0) and string.format(fmt, ...) or fmt
    return ImGui.TreeNodeBehavior(id, flags, label, #label + 1)
end

-- The reason those two functions are not yet in public API is because I would like to design a more feature-full and generic API for this.
-- They are otherwise function (cc: #3823, #9251, #7553, #6754, #5423, #2958, #2079, #1947, #1131, #722)
--- @param storage_id ImGuiID
function ImGui.TreeNodeGetOpen(storage_id)
    local g = GImGui
    local storage = g.CurrentWindow.DC.StateStorage
    return (storage[storage_id]) and true or false
end

--- @param storage_id ImGuiID
--- @param is_open    bool
function ImGui.TreeNodeSetOpen(storage_id, is_open)
    local g = GImGui
    local storage = g.CurrentWindow.DC.StateStorage
    storage[storage_id] = is_open
end

--- @param storage_id ImGuiID
--- @param flags      ImGuiTreeNodeFlags
function ImGui.TreeNodeUpdateNextOpen(storage_id, flags)
    -- Leaf node always open a new tree/id scope. If you never use it, add ImGuiTreeNodeFlags.NoTreePushOnOpen.
    if bit32.band(flags, ImGuiTreeNodeFlags.Leaf) ~= 0 then
        return true
    end

    -- We only write to the tree storage if the user clicks, or explicitly use the SetNextItemOpen function
    local g = GImGui
    local window = g.CurrentWindow
    local storage = window.DC.StateStorage

    local is_open
    if bit32.band(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasOpen) ~= 0 then
        if bit32.band(g.NextItemData.OpenCond, ImGuiCond.Always) ~= 0 then
            is_open = g.NextItemData.OpenVal
            ImGui.TreeNodeSetOpen(storage_id, is_open)
        else
            -- We treat ImGuiCond.Once and ImGuiCond.FirstUseEver the same because tree node state are not saved persistently.
            local stored_value = storage[storage_id]
            if stored_value == nil then
                is_open = g.NextItemData.OpenVal
                ImGui.TreeNodeSetOpen(storage_id, is_open)
            else
                is_open = stored_value and true or false
            end
        end
    else
        is_open = (storage[storage_id] == nil) and (bit32.band(flags, ImGuiTreeNodeFlags.DefaultOpen) ~= 0) or storage[storage_id]
    end

    -- When logging is enabled, we automatically expand tree nodes (but *NOT* collapsing headers.. seems like sensible behavior).
    -- NB- If we are above max depth we still allow manually opened nodes to be logged.
    if g.LogEnabled and bit32.band(flags, ImGuiTreeNodeFlags.NoAutoOpenOnLog) == 0 and (window.DC.TreeDepth - g.LogDepthRef) < g.LogDepthToExpand then
        is_open = true
    end

    return is_open
end

-- Store ImGuiTreeNodeStackData for just submitted node.
-- Currently only supports 32 level deep. Easy to increase to e.g. 64.
--- @param flags ImGuiTreeNodeFlags
--- @param x1    float
local function TreeNodeStoreStackData(flags, x1)
    local g = GImGui
    local window = g.CurrentWindow

    g.TreeNodeStack:resize(g.TreeNodeStack.Size + 1)
    local tree_node_data = g.TreeNodeStack.Data[g.TreeNodeStack.Size]
    tree_node_data.ID = g.LastItemData.ID
    tree_node_data.TreeFlags = flags
    tree_node_data.ItemFlags = g.LastItemData.ItemFlags
    ImRect_Copy(tree_node_data.NavRect, g.LastItemData.NavRect)

    -- Initially I tried to latch value for GetColorU32(ImGuiCol.TreeLines) but it's not a good trade-off for very large trees.
    local draw_lines = bit32.band(flags, bit32.bor(ImGuiTreeNodeFlags.DrawLinesFull, ImGuiTreeNodeFlags.DrawLinesToNodes)) ~= 0
    tree_node_data.DrawLinesX1 = draw_lines and (x1 + g.FontSize * 0.5 + g.Style.FramePadding.x) or FLT_MAX
    tree_node_data.DrawLinesTableColumn = (draw_lines and g.CurrentTable) and g.CurrentTable.CurrentColumn or -1
    tree_node_data.DrawLinesToNodesY2 = -FLT_MAX
    window.DC.TreeHasStackDataDepthMask = bit32.bor(window.DC.TreeHasStackDataDepthMask, bit32.lshift(1, window.DC.TreeDepth))
    if bit32.band(flags, ImGuiTreeNodeFlags.DrawLinesToNodes) ~= 0 then
        window.DC.TreeRecordsClippedNodesY2Mask = bit32.bor(window.DC.TreeRecordsClippedNodesY2Mask, bit32.lshift(1, window.DC.TreeDepth))
    end
end

--- @param id         ImGuiID
--- @param flags      ImGuiTreeNodeFlags
--- @param label      string
--- @param label_end? int

function ImGui.TreeNodeBehavior(id, flags, label, label_end)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local style = g.Style

    -- When not framed, we vertically increase height up to typical framed widget height
    local display_frame = bit32.band(flags, ImGuiTreeNodeFlags.Framed) ~= 0
    local use_frame_padding = display_frame or (bit32.band(flags, ImGuiTreeNodeFlags.FramePadding) ~= 0)
    -- [Luau] scalar padding, no temporary ImVec2
    local padding_x, padding_y
    if use_frame_padding then
        padding_x, padding_y = style.FramePadding.x, style.FramePadding.y
    else
        padding_x, padding_y = style.FramePadding.x, math.min(window.DC.CurrLineTextBaseOffset, style.FramePadding.y)
    end

    if label_end == nil then
        label_end = ImGui.FindRenderedTextEnd(label)
    end
    local label_size = ImGui.CalcTextSize(label, label_end, false)

    local text_offset_x = g.FontSize + (display_frame and (padding_x * 3) or (padding_x * 2)) -- Collapsing arrow width + Spacing
    local text_offset_y = use_frame_padding and ImMax(style.FramePadding.y, window.DC.CurrLineTextBaseOffset) or window.DC.CurrLineTextBaseOffset -- Latch before ItemSize changes it
    local text_width = g.FontSize + label_size.x + padding_x * 2 -- Include collapsing arrow

    local frame_height = label_size.y + padding_y * 2
    local span_all_columns = bit32.band(flags, ImGuiTreeNodeFlags.SpanAllColumns) ~= 0 and (g.CurrentTable ~= nil)
    local span_all_columns_label = bit32.band(flags, ImGuiTreeNodeFlags.LabelSpanAllColumns) ~= 0 and (g.CurrentTable ~= nil)
    local frame_bb = ImRect()
    frame_bb.Min.x = span_all_columns and window.ParentWorkRect.Min.x or (bit32.band(flags, ImGuiTreeNodeFlags.SpanFullWidth) ~= 0 and window.WorkRect.Min.x or window.DC.CursorPos.x)
    frame_bb.Min.y = window.DC.CursorPos.y + (text_offset_y - padding_y)
    frame_bb.Max.x = span_all_columns and window.ParentWorkRect.Max.x or (bit32.band(flags, ImGuiTreeNodeFlags.SpanLabelWidth) ~= 0 and window.DC.CursorPos.x + text_width + padding_x or window.WorkRect.Max.x)
    frame_bb.Max.y = window.DC.CursorPos.y + (text_offset_y - padding_y) + frame_height
    if display_frame then
        local outer_extend = IM_TRUNC(window.WindowPadding.x * 0.5) -- Framed header expand a little outside of current limits
        frame_bb.Min.x = frame_bb.Min.x - outer_extend
        frame_bb.Max.x = frame_bb.Max.x + outer_extend
    end

    local text_pos = ImVec2(window.DC.CursorPos.x + text_offset_x, window.DC.CursorPos.y + text_offset_y)
    local item_size = LayoutHelpers_size; item_size.x = text_width; item_size.y = frame_height -- [Luau] scratch, ItemSize() only reads it
    ImGui.ItemSize(item_size, padding_y)

    -- For regular tree nodes, we arbitrary allow to click past 2 worth of ItemSpacing
    local interact_bb = ImRect()
    ImRect_Copy(interact_bb, frame_bb)
    if bit32.band(flags, bit32.bor(ImGuiTreeNodeFlags.Framed, ImGuiTreeNodeFlags.SpanAvailWidth, ImGuiTreeNodeFlags.SpanFullWidth, ImGuiTreeNodeFlags.SpanLabelWidth, ImGuiTreeNodeFlags.SpanAllColumns)) == 0 then
        interact_bb.Max.x = frame_bb.Min.x + text_width + (label_size.x > 0.0 and (style.ItemSpacing.x * 2.0) or 0.0)
    end

    -- Compute open and multi-select states before ItemAdd() as it clear NextItem data.
    local storage_id = (bit32.band(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasStorageID) ~= 0) and g.NextItemData.StorageId or id
    local is_open = ImGui.TreeNodeUpdateNextOpen(storage_id, flags)

    local is_visible
    if span_all_columns or span_all_columns_label then
        -- Modify ClipRect for the ItemAdd(), faster than doing a PushColumnsBackground/PushTableBackgroundChannel for every Selectable..
        local backup_clip_rect_min_x = window.ClipRect.Min.x
        local backup_clip_rect_max_x = window.ClipRect.Max.x
        window.ClipRect.Min.x = window.ParentWorkRect.Min.x
        window.ClipRect.Max.x = window.ParentWorkRect.Max.x
        is_visible = ImGui.ItemAdd(interact_bb, id)
        window.ClipRect.Min.x = backup_clip_rect_min_x
        window.ClipRect.Max.x = backup_clip_rect_max_x
    else
        is_visible = ImGui.ItemAdd(interact_bb, id)
    end
    g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HasDisplayRect)
    ImRect_Copy(g.LastItemData.DisplayRect, frame_bb)

    -- If a NavLeft request is happening and ImGuiTreeNodeFlags.NavLeftJumpsToParent enabled:
    -- Store data for the current depth to allow returning to this node from any child item.
    -- For this purpose we essentially compare if g.NavIdIsAlive went from 0 to 1 between TreeNode() and TreePop().
    -- It will become tempting to enable ImGuiTreeNodeFlags.NavLeftJumpsToParent by default or move it to ImGuiStyle.
    local store_tree_node_stack_data = false
    if bit32.band(flags, ImGuiTreeNodeFlags.DrawLinesMask_) == 0 then
        flags = bit32.bor(flags, g.Style.TreeLinesFlags)
    end
    local draw_tree_lines = (bit32.band(flags, bit32.bor(ImGuiTreeNodeFlags.DrawLinesFull, ImGuiTreeNodeFlags.DrawLinesToNodes)) ~= 0) and (frame_bb.Min.y < window.ClipRect.Max.y) and (g.Style.TreeLinesSize > 0.0)
    if bit32.band(flags, ImGuiTreeNodeFlags.NoTreePushOnOpen) == 0 then
        store_tree_node_stack_data = draw_tree_lines
        if bit32.band(flags, ImGuiTreeNodeFlags.NavLeftJumpsToParent) ~= 0 and not g.NavIdIsAlive then
            if g.NavMoveDir == ImGuiDir.Left and g.NavWindow == window and ImGui.NavMoveRequestButNoResultYet() then
                store_tree_node_stack_data = true
            end
        end
    end

    local is_leaf = bit32.band(flags, ImGuiTreeNodeFlags.Leaf) ~= 0
    if not is_visible then
        if bit32.band(flags, ImGuiTreeNodeFlags.DrawLinesToNodes) ~= 0 and bit32.band(window.DC.TreeRecordsClippedNodesY2Mask, bit32.lshift(1, (window.DC.TreeDepth - 1))) ~= 0 then
            local parent_data = g.TreeNodeStack.Data[g.TreeNodeStack.Size]
            parent_data.DrawLinesToNodesY2 = ImMax(parent_data.DrawLinesToNodesY2, window.DC.CursorPos.y) -- Don't need to aim to mid Y position as we are clipped anyway.
            if frame_bb.Min.y >= window.ClipRect.Max.y then
                window.DC.TreeRecordsClippedNodesY2Mask = bit32.band(window.DC.TreeRecordsClippedNodesY2Mask, bit32.bnot(bit32.lshift(1, (window.DC.TreeDepth - 1)))) -- Done
            end
        end
        if is_open and store_tree_node_stack_data then
            TreeNodeStoreStackData(flags, text_pos.x - text_offset_x) -- Call before TreePushOverrideID()
        end
        if is_open and bit32.band(flags, ImGuiTreeNodeFlags.NoTreePushOnOpen) == 0 then
            ImGui.TreePushOverrideID(id)
        end
        -- IMGUI_TEST_ENGINE_ITEM_INFO(g.LastItemData.ID, label, g.LastItemData.StatusFlags | (is_leaf ? 0 : ImGuiItemStatusFlags_Openable) | (is_open ? ImGuiItemStatusFlags_Opened : 0))
        return is_open
    end

    if span_all_columns or span_all_columns_label then
        ImGui.TablePushBackgroundChannel()
        g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HasClipRect)
        ImRect_Copy(g.LastItemData.ClipRect, window.ClipRect)
    end

    local button_flags = ImGuiTreeNodeFlags.None
    if bit32.band(flags, ImGuiTreeNodeFlags.AllowOverlap) ~= 0 or bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.AllowOverlap) ~= 0 then
        button_flags = bit32.bor(button_flags, ImGuiButtonFlags.AllowOverlap)
    end
    if not is_leaf then
        button_flags = bit32.bor(button_flags, ImGuiButtonFlags.PressedOnDragDropHold)
    end

    -- We allow clicking on the arrow section with keyboard modifiers held, in order to easily
    -- allow browsing a tree while preserving selection with code implementing multi-selection patterns.
    -- When clicking on the rest of the tree node we always disallow keyboard modifiers.
    local arrow_hit_x1 = (text_pos.x - text_offset_x) - style.TouchExtraPadding.x
    local arrow_hit_x2 = (text_pos.x - text_offset_x) + (g.FontSize + padding_x * 2.0) + style.TouchExtraPadding.x
    local is_mouse_x_over_arrow = (g.IO.MousePos.x >= arrow_hit_x1 and g.IO.MousePos.x < arrow_hit_x2)

    local is_multi_select = bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.IsMultiSelect) ~= 0
    if is_multi_select then -- We absolutely need to distinguish open vs select so _OpenOnArrow comes by default
        flags = bit32.bor(flags, (bit32.band(flags, ImGuiTreeNodeFlags.OpenOnMask_) == 0) and bit32.bor(ImGuiTreeNodeFlags.OpenOnArrow, ImGuiTreeNodeFlags.OpenOnDoubleClick) or ImGuiTreeNodeFlags.OpenOnArrow)
    end

    -- Open behaviors can be altered with the _OpenOnArrow and _OnOnDoubleClick flags.
    -- Some alteration have subtle effects (e.g. toggle on MouseUp vs MouseDown events) due to requirements for multi-selection and drag and drop support.
    -- - Single-click on label = Toggle on MouseUp (default, when _OpenOnArrow=0)
    -- - Single-click on arrow = Toggle on MouseDown (when _OpenOnArrow=0)
    -- - Single-click on arrow = Toggle on MouseDown (when _OpenOnArrow=1)
    -- - Double-click on label = Toggle on MouseDoubleClick (when _OpenOnDoubleClick=1)
    -- - Double-click on arrow = Toggle on MouseDoubleClick (when _OpenOnDoubleClick=1 and _OpenOnArrow=0)
    -- It is rather standard that arrow click react on Down rather than Up.
    -- We set ImGuiButtonFlags.PressedOnClickRelease on OpenOnDoubleClick because we want the item to be active on the initial MouseDown in order for drag and drop to work.
    if is_mouse_x_over_arrow then
        button_flags = bit32.bor(button_flags, ImGuiButtonFlags.PressedOnClick)
    elseif bit32.band(flags, ImGuiTreeNodeFlags.OpenOnDoubleClick) ~= 0 then
        button_flags = bit32.bor(button_flags, ImGuiButtonFlags.PressedOnClickRelease, ImGuiButtonFlags.PressedOnDoubleClick)
    else
        button_flags = bit32.bor(button_flags, ImGuiButtonFlags.PressedOnClickRelease)
    end
    if bit32.band(flags, ImGuiTreeNodeFlags.NoNavFocus) ~= 0 then
        button_flags = bit32.bor(button_flags, ImGuiButtonFlags.NoNavFocus)
    end

    local selected = bit32.band(flags, ImGuiTreeNodeFlags.Selected) ~= 0
    local was_selected = selected

    -- Multi-selection support (header)
    if is_multi_select then
        -- Handle multi-select + alter button flags for it
        selected, button_flags = ImGui.MultiSelectItemHeader(id, selected, button_flags)
        if is_mouse_x_over_arrow then
            button_flags = bit32.band(bit32.bor(button_flags, ImGuiButtonFlags.PressedOnClick), bit32.bnot(ImGuiButtonFlags.PressedOnClickRelease))
        end
    else
        if window ~= g.HoveredWindow or not is_mouse_x_over_arrow then
            button_flags = bit32.bor(button_flags, ImGuiButtonFlags.NoKeyModsAllowed)
        end
    end

    local pressed, hovered, held = ImGui.ButtonBehavior(interact_bb, id, button_flags)
    local toggled = false
    if not is_leaf then
        if pressed and g.DragDropHoldJustPressedId ~= id then
            if bit32.band(flags, ImGuiTreeNodeFlags.OpenOnMask_) == 0 or (g.NavActivateId == id and not is_multi_select) then
                toggled = true -- Single click
            end
            if bit32.band(flags, ImGuiTreeNodeFlags.OpenOnArrow) ~= 0 then
                toggled = toggled or (is_mouse_x_over_arrow and not g.NavHighlightItemUnderNav) -- Lightweight equivalent of IsMouseHoveringRect() since ButtonBehavior() already did the job
            end
            if bit32.band(flags, ImGuiTreeNodeFlags.OpenOnDoubleClick) ~= 0 and g.IO.MouseClickedCount[0] == 2 then
                toggled = true -- Double click
            end
        elseif pressed and g.DragDropHoldJustPressedId == id then
            IM_ASSERT(bit32.band(button_flags, ImGuiButtonFlags.PressedOnDragDropHold) ~= 0)
            if not is_open then -- When using Drag and Drop "hold to open" we keep the node highlighted after opening, but never close it again.
                toggled = true
            else
                pressed = false -- Cancel press so it doesn't trigger selection.
            end
        end

        if g.NavId == id and g.NavMoveDir == ImGuiDir.Left and is_open then
            toggled = true
            ImGui.NavClearPreferredPosForAxis(ImGuiAxis.X)
            ImGui.NavMoveRequestCancel()
        end
        if g.NavId == id and g.NavMoveDir == ImGuiDir.Right and not is_open then -- If there's something upcoming on the line we may want to give it the priority?
            toggled = true
            ImGui.NavClearPreferredPosForAxis(ImGuiAxis.X)
            ImGui.NavMoveRequestCancel()
        end

        if toggled then
            is_open = not is_open
            window.DC.StateStorage[storage_id] = is_open
            g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.ToggledOpen)
        end
    end

    -- Multi-selection support (footer)
    if is_multi_select then
        local pressed_copy = pressed and not toggled
        selected, pressed_copy = ImGui.MultiSelectItemFooter(id, selected, pressed_copy)
        if pressed then
            ImGui.SetNavID(id, window.DC.NavLayerCurrent, g.CurrentFocusScopeId, interact_bb)
        end
    end

    if selected ~= was_selected then
        g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.ToggledSelection)
    end

    -- Render
    do
        local text_col = ImGui.GetColorU32(ImGuiCol.Text)
        local nav_render_cursor_flags = ImGuiNavRenderCursorFlags.Compact
        if is_multi_select then
            nav_render_cursor_flags = bit32.bor(nav_render_cursor_flags, ImGuiNavRenderCursorFlags.AlwaysDraw) -- Always show the nav rectangle
        end
        if display_frame then
            -- Framed type
            local bg_col = ImGui.GetColorU32((held and hovered) and ImGuiCol.HeaderActive or (hovered and ImGuiCol.HeaderHovered or ImGuiCol.Header))
            ImGui.RenderFrame(frame_bb.Min, frame_bb.Max, bg_col, true, style.FrameRounding)
            ImGui.RenderNavCursor(frame_bb, id, nav_render_cursor_flags)
            if span_all_columns and not span_all_columns_label then
                ImGui.TablePopBackgroundChannel()
            end
            if bit32.band(flags, ImGuiTreeNodeFlags.Bullet) ~= 0 then
                ImGui.RenderBullet(window.DrawList, ImVec2(text_pos.x - text_offset_x * 0.60, text_pos.y + g.FontSize * 0.5), text_col)
            elseif not is_leaf then
                ImGui.RenderArrow(window.DrawList, ImVec2(text_pos.x - text_offset_x + padding_x, text_pos.y), text_col, is_open and ((bit32.band(flags, ImGuiTreeNodeFlags.UpsideDownArrow) ~= 0) and ImGuiDir.Up or ImGuiDir.Down) or ImGuiDir.Right, 1.0)
            else -- Leaf without bullet, left-adjusted text
                text_pos.x = text_pos.x - (text_offset_x - padding_x)
            end
            if bit32.band(flags, ImGuiTreeNodeFlags.ClipLabelForTrailingButton) ~= 0 then
                frame_bb.Max.x = frame_bb.Max.x - (g.FontSize + style.FramePadding.x)
            end
            -- if g.LogEnabled then
            --     ImGui.LogSetNextTextDecoration("###", "###")
            -- end
        else
            -- Unframed typed for tree nodes
            if hovered or selected then
                local bg_col = ImGui.GetColorU32((held and hovered) and ImGuiCol.HeaderActive or (hovered and ImGuiCol.HeaderHovered or ImGuiCol.Header))
                ImGui.RenderFrame(frame_bb.Min, frame_bb.Max, bg_col, false, 0.0)
            end
            ImGui.RenderNavCursor(frame_bb, id, nav_render_cursor_flags, 0.0)
            if span_all_columns and not span_all_columns_label then
                ImGui.TablePopBackgroundChannel()
            end
            if bit32.band(flags, ImGuiTreeNodeFlags.Bullet) ~= 0 then
                ImGui.RenderBullet(window.DrawList, ImVec2(text_pos.x - text_offset_x * 0.5, text_pos.y + g.FontSize * 0.5), text_col)
            elseif not is_leaf then
                ImGui.RenderArrow(window.DrawList, ImVec2(text_pos.x - text_offset_x + padding_x, text_pos.y + g.FontSize * 0.15), text_col, is_open and ((bit32.band(flags, ImGuiTreeNodeFlags.UpsideDownArrow) ~= 0) and ImGuiDir.Up or ImGuiDir.Down) or ImGuiDir.Right, 0.70)
            end
            -- if g.LogEnabled then
            --     ImGui.LogSetNextTextDecoration(">", nil)
            -- end
        end

        if draw_tree_lines then
            ImGui.TreeNodeDrawLineToChildNode(ImVec2(text_pos.x - text_offset_x + padding_x, text_pos.y + g.FontSize * 0.5))
        end

        -- Label
        if display_frame then
            ImGui.RenderTextClipped(text_pos, frame_bb.Max, label, label_end, label_size)
        else
            ImGui.RenderText(text_pos, label, 1, label_end, false)
        end

        if span_all_columns_label then
            ImGui.TablePopBackgroundChannel()
        end
    end

    if is_open and store_tree_node_stack_data then
        TreeNodeStoreStackData(flags, text_pos.x - text_offset_x) -- Call before TreePushOverrideID()
    end
    if is_open and bit32.band(flags, ImGuiTreeNodeFlags.NoTreePushOnOpen) == 0 then
        ImGui.TreePushOverrideID(id) -- Could use TreePush(label) but this avoid computing twice
    end

    -- IMGUI_TEST_ENGINE_ITEM_INFO(id, label, g.LastItemData.StatusFlags | (is_leaf ? 0 : ImGuiItemStatusFlags_Openable) | (is_open ? ImGuiItemStatusFlags_Opened : 0));
    return is_open
end

-- Draw horizontal line from our parent node
-- This is only called for visible child nodes so we are not too fussy anymore about performances
--- @param target_pos ImVec2
function ImGui.TreeNodeDrawLineToChildNode(target_pos)
    local g = GImGui
    local window = g.CurrentWindow
    if window.DC.TreeDepth == 0 or bit32.band(window.DC.TreeHasStackDataDepthMask, bit32.lshift(1, window.DC.TreeDepth - 1)) == 0 then
        return
    end

    -- FIXME: Could this be simplified using new stroke flags?
    local parent_data = g.TreeNodeStack.Data[g.TreeNodeStack.Size]
    local x1 = ImTrunc(parent_data.DrawLinesX1)
    local x2 = ImTrunc(target_pos.x - g.Style.ItemInnerSpacing.x)
    local y = ImTrunc(target_pos.y)
    local rounding = (g.Style.TreeLinesRounding > 0.0) and ImMin(x2 - x1, g.Style.TreeLinesRounding) or 0.0
    parent_data.DrawLinesToNodesY2 = ImMax(parent_data.DrawLinesToNodesY2, y - rounding)
    if x1 >= x2 then
        return
    end
    if rounding > 0.0 then
        x1 = x1 + 0.5 + rounding
        window.DrawList:PathArcToFast(ImVec2(x1, y - rounding), rounding, 6, 3)
        if x1 < x2 then
            window.DrawList:PathLineTo(ImVec2(x2, y))
        end
        window.DrawList:PathStroke(ImGui.GetColorU32(ImGuiCol.TreeLines), g.Style.TreeLinesSize)
    else
        window.DrawList:AddLineH(x1, x2, y, ImGui.GetColorU32(ImGuiCol.TreeLines), g.Style.TreeLinesSize)
    end
end

-- Draw vertical line of the hierarchy
--- @param data ImGuiTreeNodeStackData
function ImGui.TreeNodeDrawLineToTreePop(data)
    local g = GImGui
    local window = g.CurrentWindow
    local y1 = ImMax(data.NavRect.Max.y, window.ClipRect.Min.y)
    local y2 = data.DrawLinesToNodesY2
    if bit32.band(data.TreeFlags, ImGuiTreeNodeFlags.DrawLinesFull) ~= 0 then
        local y2_full = window.DC.CursorPos.y
        if g.CurrentTable then
            y2_full = ImMax(g.CurrentTable.RowPosY2, y2_full)
        end
        y2_full = ImTrunc(y2_full - g.Style.ItemSpacing.y - g.FontSize * 0.5)
        if y2 + (g.Style.ItemSpacing.y + g.Style.TreeLinesRounding) < y2_full then -- FIXME: threshold to use ToNodes Y2 instead of Full Y2 when close by ItemSpacing.y
            y2 = y2_full
        end
    end
    y2 = ImMin(y2, window.ClipRect.Max.y)
    if y2 <= y1 then
        return
    end
    local x = ImTrunc(data.DrawLinesX1 - g.Style.TreeLinesSize * 0.5) + g.Style.TreeLinesSize * 0.5 -- Draw line centered at X1, but snap to pixels boundary.
    if data.DrawLinesTableColumn ~= -1 then
        ImGui.TablePushColumnChannel(data.DrawLinesTableColumn)
    end

    -- We use AddLine() instead of AddLineV() as we provide coordinates for line center (FIXME-OPT)
    window.DrawList:AddLine(ImVec2(x, y1), ImVec2(x, y2), ImGui.GetColorU32(ImGuiCol.TreeLines), g.Style.TreeLinesSize)
    if data.DrawLinesTableColumn ~= -1 then
        ImGui.TablePopColumnChannel()
    end
end

--- @param str_id string|ImGuiID
function ImGui.TreePush(str_id)
    local window = ImGui.GetCurrentWindow()
    ImGui.Indent()
    window.DC.TreeDepth = window.DC.TreeDepth + 1
    ImGui.PushID(str_id)
end

--- @param id ImGuiID
function ImGui.TreePushOverrideID(id)
    local g = GImGui
    local window = g.CurrentWindow
    ImGui.Indent()
    window.DC.TreeDepth = window.DC.TreeDepth + 1
    ImGui.PushOverrideID(id)
end

function ImGui.TreePop()
    local g = GImGui
    local window = g.CurrentWindow
    ImGui.Unindent()

    window.DC.TreeDepth = window.DC.TreeDepth - 1
    local tree_depth_mask = bit32.lshift(1, window.DC.TreeDepth)

    if bit32.band(window.DC.TreeHasStackDataDepthMask, tree_depth_mask) ~= 0 then
        local data = g.TreeNodeStack.Data[g.TreeNodeStack.Size]
        IM_ASSERT(data.ID == window.IDStack:back())

        -- Handle Left arrow to move to parent tree node (when ImGuiTreeNodeFlags.NavLeftJumpsToParent is enabled)
        if bit32.band(data.TreeFlags, ImGuiTreeNodeFlags.NavLeftJumpsToParent) ~= 0 then
            if g.NavIdIsAlive and g.NavMoveDir == ImGuiDir.Left and g.NavWindow == window and ImGui.NavMoveRequestButNoResultYet() then
                ImGui.NavMoveRequestResolveWithPastTreeNode(g.NavMoveResultLocal, data)
            end
        end

        -- Draw hierarchy lines
        if data.DrawLinesX1 ~= FLT_MAX and window.DC.CursorPos.y >= window.ClipRect.Min.y then
            ImGui.TreeNodeDrawLineToTreePop(data)
        end

        g.TreeNodeStack:pop_back()
        window.DC.TreeHasStackDataDepthMask = bit32.band(window.DC.TreeHasStackDataDepthMask, bit32.bnot(tree_depth_mask))
        window.DC.TreeRecordsClippedNodesY2Mask = bit32.band(window.DC.TreeRecordsClippedNodesY2Mask, bit32.bnot(tree_depth_mask))
    end

    IM_ASSERT(window.IDStack.Size > 1) -- There should always be 1 element in the IDStack (pushed during window creation). If this triggers you called TreePop/PopID too much.
    ImGui.PopID()
end

-- Set next TreeNode/CollapsingHeader open state.
--- @param is_open bool
--- @param cond?   ImGuiCond
function ImGui.SetNextItemOpen(is_open, cond)
    if cond == nil then cond = 0 end

    local g = GImGui
    if g.CurrentWindow.SkipItems then
        return
    end
    g.NextItemData.HasFlags = bit32.bor(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasOpen)
    g.NextItemData.OpenVal = is_open
    g.NextItemData.OpenCond = (cond ~= 0) and cond or ImGuiCond.Always
end

-- Horizontal distance preceding label when using TreeNode() or Bullet()
function ImGui.GetTreeNodeToLabelSpacing()
    local g = GImGui
    return g.FontSize + (g.Style.FramePadding.x * 2.0)
end

-- Set next TreeNode/CollapsingHeader storage id.
--- @param storage_id ImGuiID
function ImGui.SetNextItemStorageID(storage_id)
    local g = GImGui
    if g.CurrentWindow.SkipItems then
        return
    end
    g.NextItemData.HasFlags = bit32.bor(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasStorageID)
    g.NextItemData.StorageId = storage_id
end

-- CollapsingHeader returns true when opened but do not indent nor push into the ID stack (because of the ImGuiTreeNodeFlags.NoTreePushOnOpen flag).
-- This is basically the same as calling TreeNodeEx(label, ImGuiTreeNodeFlags.CollapsingHeader). You can remove the _NoTreePushOnOpen flag if you want behavior closer to normal TreeNode().
-- Overloads: CollapsingHeader(label, flags?) -> is_open
--            CollapsingHeader(label, p_visible: bool, flags?) -> is_open, p_visible
-- p_visible == nil   : regular collapsing header
-- p_visible == true  : show a small close button on the corner of the header, clicking the button will set p_visible = false (returned as 2nd value)
-- p_visible == false : do not show the header at all
-- Do not mistake this with the Open state of the header itself, which you can adjust with SetNextItemOpen() or ImGuiTreeNodeFlags.DefaultOpen.
--- @param label  string

function ImGui.CollapsingHeader(label, a, b)
    local p_visible, flags
    if type(a) == "boolean" then p_visible, flags = a, b else flags = a end
    if flags == nil then flags = 0 end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false, p_visible
    end

    if p_visible == false then
        return false, p_visible
    end

    local id = window:GetID(label)
    flags = bit32.bor(flags, ImGuiTreeNodeFlags.CollapsingHeader)
    if p_visible ~= nil then
        flags = bit32.bor(flags, ImGuiTreeNodeFlags.AllowOverlap, ImGuiTreeNodeFlags.ClipLabelForTrailingButton)
    end
    local is_open = ImGui.TreeNodeBehavior(id, flags, label)
    if p_visible ~= nil then
        -- Create a small overlapping close button
        -- FIXME: We can evolve this into user accessible helpers to add extra buttons on title bars, headers, etc.
        -- FIXME: CloseButton can overlap into text, need find a way to clip the text somehow.
        local g = GImGui
        local last_item_backup = ImGuiLastItemData()
        ImGuiLastItemData_Copy(last_item_backup, g.LastItemData)
        local button_size = g.FontSize
        local button_x = ImMax(g.LastItemData.Rect.Min.x, g.LastItemData.Rect.Max.x - g.Style.FramePadding.x - button_size)
        local button_y = g.LastItemData.Rect.Min.y + g.Style.FramePadding.y
        local close_button_id = ImGui.GetIDWithSeed("#CLOSE", nil, id)
        if ImGui.CloseButton(close_button_id, ImVec2(button_x, button_y)) then
            p_visible = false
        end
        ImGuiLastItemData_Copy(g.LastItemData, last_item_backup)
    end

    return is_open, p_visible
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: Selectable
-------------------------------------------------------------------------------
-- - Selectable()
-------------------------------------------------------------------------------

-- Tip: pass a non-visible label (e.g. "##hello") then you can use the space to draw other text or image.
-- But you need to make sure the ID is unique, e.g. enclose calls in PushID/PopID or use ##unique_id.
-- With this scheme, ImGuiSelectableFlags.SpanAllColumns and ImGuiSelectableFlags.AllowOverlap are also frequently used flags.
-- FIXME: Selectable() with (size.x == 0.0f) and (SelectableTextAlign.x > 0.0f) followed by SameLine() is currently not supported.
--- @param label     string
--- @param selected? bool
--- @param flags?    ImGuiSelectableFlags
--- @param size_arg? any
--- @return bool is_pressed
--- @return bool is_selected # Updated `selected`

function ImGui.Selectable(label, selected, flags, size_arg)
    if selected == nil then selected = false        end
    if flags    == nil then flags    = 0            end
    if size_arg == nil then size_arg = LAYOUT_ZERO_SIZE end -- [Luau] shared read-only default (only read below)

    local window = ImGui.GetCurrentWindow()
    if (window.SkipItems) then
        return false, selected
    end

    local g = GImGui
    local style = g.Style

    -- Submit label or explicit size to ItemSize(), whereas ItemAdd() will submit a larger/spanning rectangle.
    local id = window:GetID(label)
    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)
    local size = ImVec2((size_arg.x ~= 0.0) and size_arg.x or label_size.x, (size_arg.y ~= 0.0) and size_arg.y or label_size.y)

    local pos = ImVec2()
    ImVec2_Copy(pos, window.DC.CursorPos)
    pos.y = pos.y + window.DC.CurrLineTextBaseOffset

    ImGui.ItemSize(size, 0.0)

    -- Fill horizontal space
    -- We don't support (size < 0.0) in Selectable() because the ItemSpacing extension would make explicitly right-aligned sizes not visibly match other widgets.
    local span_all_columns = bit32.band(flags, ImGuiSelectableFlags.SpanAllColumns) ~= 0
    local min_x = span_all_columns and window.ParentWorkRect.Min.x or pos.x
    local max_x = span_all_columns and window.ParentWorkRect.Max.x or window.WorkRect.Max.x
    if size_arg.x == 0.0 or bit32.band(flags, ImGuiSelectableFlags.SpanAvailWidth) ~= 0 then
        size.x = ImMax(label_size.x, max_x - min_x)
    end

    -- Selectables are meant to be tightly packed together with no click-gap, so we extend their box to cover spacing between selectable.
    -- FIXME: Not part of layout so not included in clipper calculation, but ItemSize currently doesn't allow offsetting CursorPos.
    local bb = ImRect(min_x, pos.y, min_x + size.x, pos.y + size.y)
    if bit32.band(flags, ImGuiSelectableFlags.NoPadWithHalfSpacing) == 0 then
        local spacing_x = span_all_columns and 0.0 or style.ItemSpacing.x
        local spacing_y = style.ItemSpacing.y
        local spacing_L = IM_TRUNC(spacing_x * 0.50)
        local spacing_U = IM_TRUNC(spacing_y * 0.50)

        bb.Min.x = bb.Min.x - spacing_L
        bb.Min.y = bb.Min.y - spacing_U
        bb.Max.x = bb.Max.x + (spacing_x - spacing_L)
        bb.Max.y = bb.Max.y + (spacing_y - spacing_U)
    end
    -- if g.IO.KeyCtrl then ImGui.GetForegroundDrawList():AddRect(bb.Min, bb.Max, IM_COL32(0, 255, 0, 255)) end

    local disabled_item = bit32.band(flags, ImGuiSelectableFlags.Disabled) ~= 0
    local extra_item_flags = disabled_item and ImGuiItemFlags.Disabled or ImGuiItemFlags.None

    local is_visible
    if span_all_columns then
        -- Modify ClipRect for the ItemAdd(), faster than doing a PushColumnsBackground/PushTableBackgroundChannel for every Selectable..
        local backup_clip_rect_min_x = window.ClipRect.Min.x
        local backup_clip_rect_max_x = window.ClipRect.Max.x

        window.ClipRect.Min.x = window.ParentWorkRect.Min.x
        window.ClipRect.Max.x = window.ParentWorkRect.Max.x

        is_visible = ImGui.ItemAdd(bb, id, nil, extra_item_flags)

        window.ClipRect.Min.x = backup_clip_rect_min_x
        window.ClipRect.Max.x = backup_clip_rect_max_x
    else
        is_visible = ImGui.ItemAdd(bb, id, nil, extra_item_flags)
    end

    local is_multi_select = bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.IsMultiSelect) ~= 0

    if not is_visible then
        if not is_multi_select or not g.BoxSelectState.UnclipMode or not g.BoxSelectState.UnclipRect:Overlaps(bb) then -- Extra layer of "no logic clip" for box-select support (would be more overhead to add to ItemAdd)
            return false, selected
        end
    end

    local disabled_global = bit32.band(g.CurrentItemFlags, ImGuiItemFlags.Disabled) ~= 0

    if disabled_item and not disabled_global then -- Only testing this as an optimization
        ImGui.BeginDisabled()
    end

    -- FIXME: We can standardize the behavior of those two, we could also keep the fast path of override ClipRect + full push on render only,
    -- which would be advantageous since most selectable are not selected.
    if span_all_columns then
        if g.CurrentTable then
            ImGui.TablePushBackgroundChannel()
        elseif window.DC.CurrentColumns then
            ImGui.PushColumnsBackground()
        end

        g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HasClipRect)
        ImRect_Copy(g.LastItemData.ClipRect, window.ClipRect)
    end

    -- We use NoHoldingActiveID on menus so user can click and _hold_ on a menu then drag to browse child entries
    local button_flags = 0
    if bit32.band(flags, ImGuiSelectableFlags.NoHoldingActiveID) ~= 0 then button_flags = bit32.bor(button_flags, ImGuiButtonFlags.NoHoldingActiveId) end
    if bit32.band(flags, ImGuiSelectableFlags.NoSetKeyOwner)     ~= 0 then button_flags = bit32.bor(button_flags, ImGuiButtonFlags.NoSetKeyOwner) end
    if bit32.band(flags, ImGuiSelectableFlags.SelectOnClick)     ~= 0 then button_flags = bit32.bor(button_flags, ImGuiButtonFlags.PressedOnClick) end
    if bit32.band(flags, ImGuiSelectableFlags.SelectOnRelease)   ~= 0 then button_flags = bit32.bor(button_flags, ImGuiButtonFlags.PressedOnRelease) end
    if bit32.band(flags, ImGuiSelectableFlags.AllowDoubleClick)  ~= 0 then button_flags = bit32.bor(button_flags, ImGuiButtonFlags.PressedOnClickRelease, ImGuiButtonFlags.PressedOnDoubleClick) end
    if bit32.band(flags, ImGuiSelectableFlags.AllowOverlap) ~= 0 or bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.AllowOverlap) ~= 0 then button_flags = bit32.bor(button_flags, ImGuiButtonFlags.AllowOverlap) end

    -- Multi-selection support (header)
    local was_selected = selected
    if is_multi_select then
        -- Handle multi-select + alter button flags for it
        -- TODO: selected, button_flags = ImGui.MultiSelectItemHeader(id, selected, button_flags)
    end

    local pressed, hovered, held = ImGui.ButtonBehavior(bb, id, button_flags)
    local auto_selected = false

    -- Multi-selection support (footer)
    if is_multi_select then
        -- TODO: selected, pressed = ImGui.MultiSelectItemFooter(id, selected, pressed)
    else
        -- Auto-select when moved into
        -- - This will be more fully fleshed in the range-select branch
        -- - This is not exposed as it won't nicely work with some user side handling of shift/control
        -- - We cannot do 'if (g.NavJustMovedToId != id) { selected = false; pressed = was_selected; }' for two reasons
        --   - (1) it would require focus scope to be set, need exposing PushFocusScope() or equivalent (e.g. BeginSelection() calling PushFocusScope())
        --   - (2) usage will fail with clipped items
        --   The multi-select API aim to fix those issues, e.g. may be replaced with a BeginSelection() API.
        if bit32.band(flags, ImGuiSelectableFlags.SelectOnNav) ~= 0 and g.NavJustMovedToId ~= 0 and g.NavJustMovedToFocusScopeId == g.CurrentFocusScopeId then
            if g.NavJustMovedToId == id and bit32.band(g.NavJustMovedToKeyMods, ImGuiMod_Ctrl) == 0 then
                selected = true
                pressed = true
                auto_selected = true
            end
        end
    end

    -- Update NavId when clicking or when Hovering (this doesn't happen on most widgets), so navigation can be resumed with keyboard/gamepad
    if pressed or (hovered and bit32.band(flags, ImGuiSelectableFlags.SetNavIdOnHover) ~= 0) then
        if not g.NavHighlightItemUnderNav and g.NavWindow == window and g.NavLayer == window.DC.NavLayerCurrent then
            ImGui.SetNavID(id, window.DC.NavLayerCurrent, g.CurrentFocusScopeId, ImGui.WindowRectAbsToRel(window, bb)) -- (bb == NavRect)
            if g.IO.ConfigNavCursorVisibleAuto then
                g.NavCursorVisible = false
            end
        end
    end
    if pressed then
        ImGui.MarkItemEdited(id)
    end

    if selected ~= was_selected then
        g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.ToggledSelection)
    end
    if g.ActiveId == id and g.ActiveIdIsJustActivated then
        g.ActiveIdWasSelected = was_selected
        g.ActiveIdWasSoleSelected = was_selected and (not is_multi_select or g.CurrentMultiSelect.IsSoleOrUnknownSelectionSize)
    end

    -- Render
    if is_visible then
        local highlighted = hovered or (bit32.band(flags, ImGuiSelectableFlags.Highlight) ~= 0)

        if highlighted or selected then
            -- Between 1.91.0 and 1.91.4 we made selected Selectable use an arbitrary lerp between _Header and _HeaderHovered. Removed that now. (#8106)
            local col
            if held and highlighted then
                col = ImGui.GetColorU32(ImGuiCol.HeaderActive)
            elseif highlighted then
                col = ImGui.GetColorU32(ImGuiCol.HeaderHovered)
            else
                col = ImGui.GetColorU32(ImGuiCol.Header)
            end
            ImGui.RenderFrame(bb.Min, bb.Max, col, false, style.SelectableRounding)
        end

        if g.NavId == id then
            local nav_render_cursor_flags = ImGuiNavRenderCursorFlags.Compact
            if is_multi_select then
                nav_render_cursor_flags = bit32.bor(nav_render_cursor_flags, ImGuiNavRenderCursorFlags.AlwaysDraw) -- Always show the nav rectangle
            end
            ImGui.RenderNavCursor(bb, id, nav_render_cursor_flags, style.SelectableRounding)
        end
    end

    if span_all_columns then
        if g.CurrentTable then
            ImGui.TablePopBackgroundChannel()
        elseif window.DC.CurrentColumns then
            ImGui.PopColumnsBackground()
        end
    end

    -- Text stays at the submission position. Alignment/clipping extents ignore SpanAllColumns.
    if is_visible then
        ImGui.RenderTextClipped(pos, ImVec2(ImMin(pos.x + size.x, window.WorkRect.Max.x), pos.y + size.y), label, label_end, label_size, style.SelectableTextAlign, bb)
    end

    -- Automatically close popups
    if pressed and not auto_selected and bit32.band(window.Flags, ImGuiWindowFlags.Popup) ~= 0 and bit32.band(flags, ImGuiSelectableFlags.NoAutoClosePopups) == 0 and bit32.band(g.LastItemData.ItemFlags, ImGuiItemFlags.AutoClosePopups) ~= 0 then
        ImGui.CloseCurrentPopup()
    end

    if disabled_item and not disabled_global then
        ImGui.EndDisabled()
    end

    -- Selectable() always returns a pressed state!
    -- Users of BeginMultiSelect()/EndMultiSelect() scope: you may call ImGui.IsItemToggledSelection() to retrieve
    -- selection toggle, only useful if you need that state updated (e.g. for rendering purpose) before reaching EndMultiSelect().
    return pressed, selected
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: ListBox
-------------------------------------------------------------------------------
-- - BeginListBox()
-- - EndListBox()
-- - ListBox()
-------------------------------------------------------------------------------

-- This is essentially a thin wrapper to using BeginChild/EndChild with the ImGuiChildFlags.FrameStyle flag for stylistic changes + displaying a label.
-- This handle some subtleties with capturing info from the label.
-- If you don't need a label you can pretty much directly use ImGui.BeginChild() with ImGuiChildFlags.FrameStyle.
-- Tip: To have a list filling the entire window width, use size.x = -FLT_MIN and pass an non-visible label e.g. "##empty"
-- Tip: If your vertical size is calculated from an item count (e.g. 10 * item_height) consider adding a fractional part to facilitate seeing scrolling boundaries (e.g. 10.5f * item_height).
--- @param label     string
--- @param size_arg? ImVec2
function ImGui.BeginListBox(label, size_arg)
    if size_arg == nil then size_arg = ImVec2(0, 0) end
    local g = GImGui
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local style = g.Style
    local id = ImGui.GetID(label)
    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)

    -- Size default to hold ~7.25 items.
    -- Fractional number of items helps seeing that we can scroll down/up without looking at scrollbar.
    local size = ImTrunc(ImGui.CalcItemSize(size_arg, ImGui.CalcItemWidth(), ImGui.GetTextLineHeightWithSpacing() * 7.25 + style.FramePadding.y * 2.0))
    local frame_size = ImVec2(size.x, ImMax(size.y, label_size.y))
    local frame_bb = ImRect(window.DC.CursorPos, window.DC.CursorPos + frame_size)
    local bb = ImRect(frame_bb.Min, frame_bb.Max + ImVec2((label_size.x > 0.0) and (style.ItemInnerSpacing.x + label_size.x) or 0.0, 0.0))
    g.NextItemData:ClearFlags()

    if not ImGui.IsRectVisible(bb.Min, bb.Max) then
        ImGui.ItemSize(bb:GetSize(), style.FramePadding.y)
        ImGui.ItemAdd(bb, 0, frame_bb)
        g.NextWindowData:ClearFlags() -- We behave like Begin() and need to consume those values
        return false
    end

    -- FIXME-OPT: We could omit the BeginGroup() if label_size.x == 0.0f but would need to omit the EndGroup() as well.
    ImGui.BeginGroup()
    if label_size.x > 0.0 then
        local label_pos = ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y)
        ImGui.RenderText(label_pos, label, 1, label_end, false)
        ImVec2_Copy(window.DC.CursorMaxPos, ImMax(window.DC.CursorMaxPos, label_pos + label_size))
        ImGui.AlignTextToFramePadding()
    end

    ImGui.BeginChild(id, frame_bb:GetSize(), ImGuiChildFlags.FrameStyle)
    return true
end

function ImGui.EndListBox()
    local g = GImGui
    local window = g.CurrentWindow
    IM_ASSERT(bit32.band(window.Flags, ImGuiWindowFlags.ChildWindow) ~= 0, "Mismatched BeginListBox/EndListBox calls. Did you test the return value of BeginListBox?")

    ImGui.EndChild()
    ImGui.EndGroup() -- This is only required to be able to do IsItemXXX query on the whole ListBox including label
end

-- This is merely a helper around BeginListBox(), EndListBox().
-- Considering using those directly to submit custom data or store selection differently.
-- Overloads: (label, current_item, items[], items_count?, height_in_items?) or (label, current_item, getter, user_data, items_count, height_in_items?)
--- @param current_item int # 0-based
--- @return int  current_item
--- @return bool value_changed
function ImGui.ListBox(label, current_item, a, b, c, d)
    local g = GImGui
    local getter, user_data, items_count, height_in_items = Items_ResolveArgs(a, b, c, d)
    if height_in_items == nil then height_in_items = -1 end

    -- Calculate size from "height_in_items"
    if height_in_items < 0 then
        height_in_items = ImMin(items_count, 7)
    end
    local height_in_items_f = height_in_items + 0.25
    local size = ImVec2(0.0, ImTrunc(ImGui.GetTextLineHeightWithSpacing() * height_in_items_f + g.Style.FramePadding.y * 2.0))

    if not ImGui.BeginListBox(label, size) then
        return current_item, false
    end

    -- Assume all items have even height (= 1 line of text). If you need items of different height,
    -- you can create a custom version of ListBox() in your code without using the clipper.
    local value_changed = false
    local clipper = ImGuiListClipper()
    clipper:Begin(items_count, ImGui.GetTextLineHeightWithSpacing()) -- We know exactly our line height here so we pass it as a minor optimization, but generally you don't need to.
    clipper:IncludeItemByIndex(current_item)
    while clipper:Step() do
        for i = clipper.DisplayStart, clipper.DisplayEnd - 1 do
            local item_text = getter(user_data, i)
            if item_text == nil then
                item_text = "*Unknown item*"
            end

            ImGui.PushID(i)
            local item_selected = (i == current_item)
            if ImGui.Selectable(item_text, item_selected) then
                current_item = i
                value_changed = true
            end
            if item_selected then
                ImGui.SetItemDefaultFocus()
            end
            ImGui.PopID()
        end
    end
    ImGui.EndListBox()

    if value_changed then
        ImGui.MarkItemEdited(g.LastItemData.ID)
    end

    return current_item, value_changed
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: PlotLines, PlotHistogram
-------------------------------------------------------------------------------
-- - PlotEx() [Internal]
-- - PlotLines()
-- - PlotHistogram()
-------------------------------------------------------------------------------
-- Plot/Graph widgets are not very good.
-- Consider using ImPlot (https://github.com/epezent/implot) which is much better!
-------------------------------------------------------------------------------

--- @param plot_type     ImGuiPlotType
--- @param label         string
--- @param values_getter fun(data?: table, idx: int): float
--- @param data?         table                              # 1-based table
--- @param values_count  int
--- @param values_offset int
--- @param overlay_text? string
--- @param scale_min     float
--- @param scale_max     float
--- @param size_arg      ImVec2
--- @return int
function ImGui.PlotEx(plot_type, label, values_getter, data, values_count, values_offset, overlay_text, scale_min, scale_max, size_arg)
    local g = GImGui
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return -1
    end

    local style = g.Style
    local id = window:GetID(label)

    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)
    local frame_size = ImGui.CalcItemSize(size_arg, ImGui.CalcItemWidth(), label_size.y + style.FramePadding.y * 2.0)

    local frame_bb = ImRect(window.DC.CursorPos, window.DC.CursorPos + frame_size)
    local inner_bb = ImRect(frame_bb.Min + style.FramePadding, frame_bb.Max - style.FramePadding)
    local total_bb = ImRect(frame_bb.Min, frame_bb.Max + ImVec2(label_size.x > 0.0 and style.ItemInnerSpacing.x + label_size.x or 0.0, 0))
    ImGui.ItemSize(total_bb, style.FramePadding.y)
    if not ImGui.ItemAdd(total_bb, id, frame_bb, ImGuiItemFlags.NoNav) then
        return -1
    end

    local _, hovered, _ = ImGui.ButtonBehavior(frame_bb, id)

    -- Determine scale from values if not specified
    if scale_min == FLT_MAX or scale_max == FLT_MAX then
        local v_min = FLT_MAX
        local v_max = -FLT_MAX
        for i = 1, values_count do
            local v = values_getter(data, i) -- NaN isn't checked here

            v_min = ImMin(v_min, v)
            v_max = ImMax(v_max, v)
        end
        if scale_min == FLT_MAX then
            scale_min = v_min
        end
        if scale_max == FLT_MAX then
            scale_max = v_max
        end
    end

    ImGui.RenderFrame(frame_bb.Min, frame_bb.Max, ImGui.GetColorU32(ImGuiCol.FrameBg), true, style.FrameRounding)

    local values_count_min = (plot_type == ImGuiPlotType.Lines) and 2 or 1
    local idx_hovered = -1

    if values_count >= values_count_min then
        local res_w = ImMin(math.floor(frame_size.x), values_count) + ((plot_type == ImGuiPlotType.Lines) and -1 or 0)
        local item_count = values_count + ((plot_type == ImGuiPlotType.Lines) and -1 or 0)

        -- Tooltip on hover
        if hovered and inner_bb:Contains(g.IO.MousePos) then
            local t = ImClamp((g.IO.MousePos.x - inner_bb.Min.x) / (inner_bb.Max.x - inner_bb.Min.x), 0.0, 0.999)
            local v_idx = math.floor(t * item_count) + 1
            IM_ASSERT(v_idx >= 1 and v_idx <= values_count)

            local v0 = values_getter(data, (v_idx - 1 + values_offset) % values_count + 1)
            local v1 = values_getter(data, (v_idx - 1 + 1 + values_offset) % values_count + 1)
            if plot_type == ImGuiPlotType.Lines then
                ImGui.SetTooltip("%d: %8.4g\n%d: %8.4g", v_idx, v0, v_idx + 1, v1)
            elseif plot_type == ImGuiPlotType.Histogram then
                ImGui.SetTooltip("%d: %8.4g", v_idx, v0)
            end
            idx_hovered = v_idx
        end

        local t_step = 1.0 / res_w
        local inv_scale = (scale_min == scale_max) and 0.0 or (1.0 / (scale_max - scale_min))

        local v0 = values_getter(data, (0 + values_offset) % values_count + 1)
        local t0 = 0.0
        local tp0 = ImVec2(t0, 1.0 - ImSaturate((v0 - scale_min) * inv_scale)) -- Point in the normalized space of our target rectangle
        local histogram_zero_line_t = (scale_min * scale_max < 0.0) and (1 + scale_min * inv_scale) or (scale_min < 0.0 and 0.0 or 1.0) -- Where does the zero line stands

        local col_base = ImGui.GetColorU32((plot_type == ImGuiPlotType.Lines) and ImGuiCol.PlotLines or ImGuiCol.PlotHistogram)
        local col_hovered = ImGui.GetColorU32((plot_type == ImGuiPlotType.Lines) and ImGuiCol.PlotLinesHovered or ImGuiCol.PlotHistogramHovered)

        for _ = 0, res_w - 1 do
            local t1 = t0 + t_step
            local v1_idx = math.floor(t0 * item_count + 0.5) + 1
            IM_ASSERT(v1_idx >= 1 and v1_idx <= values_count)
            local v1 = values_getter(data, (v1_idx - 1 + values_offset + 1) % values_count + 1)
            local tp1 = ImVec2(t1, 1.0 - ImSaturate((v1 - scale_min) * inv_scale))

            -- NB: Draw calls are merged together by the DrawList system. Still, we should render our batch are lower level to save a bit of CPU.
            local pos0 = ImLerp(inner_bb.Min, inner_bb.Max, tp0)
            local pos1
            if plot_type == ImGuiPlotType.Lines then
                pos1 = ImLerp(inner_bb.Min, inner_bb.Max, tp1)
            else
                pos1 = ImLerp(inner_bb.Min, inner_bb.Max, ImVec2(tp1.x, histogram_zero_line_t))
            end

            if plot_type == ImGuiPlotType.Lines then
                window.DrawList:AddLine(pos0, pos1, idx_hovered == v1_idx and col_hovered or col_base)
            elseif plot_type == ImGuiPlotType.Histogram then
                if pos1.x >= pos0.x + 2.0 then
                    pos1.x = pos1.x - 1.0
                end
                window.DrawList:AddRectFilled(pos0, pos1, idx_hovered == v1_idx and col_hovered or col_base)
            end

            t0 = t1
            tp0 = tp1
        end
    end

    -- Text overlay
    if overlay_text then
        ImGui.RenderTextClipped(ImVec2(frame_bb.Min.x, frame_bb.Min.y + style.FramePadding.y), frame_bb.Max, overlay_text, nil, nil, ImVec2(0.5, 0.0))
    end

    if label_size.x > 0.0 then
        ImGui.RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, inner_bb.Min.y), label, 1, label_end, false)
    end

    -- Return hovered index or -1 if none are hovered.
    -- This is currently not exposed in the public API because we need a larger redesign of the whole thing, but in the short-term we are making it available in PlotEx().
    return idx_hovered
end

--- @class ImGuiPlotArrayGetterData
--- @field Values float[]
--- @field Stride int

--- @param values float[]
--- @param stride int
--- @return ImGuiPlotArrayGetterData
--- @nodiscard
function ImGuiPlotArrayGetterData(values, stride)
    return {
        Values = values,
        Stride = stride
    }
end

--- @param data ImGuiPlotArrayGetterData
--- @param idx int
--- @return float
--- @package
local function Plot_ArrayGetter(data, idx)
    return data.Values[idx * data.Stride]
end

--- @param label            string
--- @param values_or_getter table|fun(data:table, i:int)  # 1-based table or a function
--- @param data?            table                         # 1-based table
--- @param values_count     int
--- @param values_offset?   int                           # Defaults to 0
--- @param overlay_text?    string
--- @param scale_min?       float                         # Defaults to FLT_MAX
--- @param scale_max?       float                         # Defaults to FLT_MAX
--- @param graph_size?      ImVec2                        # Defaults to ImVec2(0, 0)
--- @param stride?          int                           # Defaults to 1
function ImGui.PlotLines(label, values_or_getter, data, values_count, values_offset, overlay_text, scale_min, scale_max, graph_size, stride)
    if values_offset == nil then values_offset = 0         end
    if scale_min     == nil then scale_min  = FLT_MAX      end
    if scale_max     == nil then scale_max  = FLT_MAX      end
    if graph_size    == nil then graph_size = ImVec2(0, 0) end
    if stride        == nil then stride     = 1            end

    if type(values_or_getter) == "function" then
        ImGui.PlotEx(ImGuiPlotType.Lines, label, values_or_getter, data, values_count, values_offset, overlay_text, scale_min, scale_max, graph_size)
    else
        data = ImGuiPlotArrayGetterData(values_or_getter, stride)
        ImGui.PlotEx(ImGuiPlotType.Lines, label, Plot_ArrayGetter, data, values_count, values_offset, overlay_text, scale_min, scale_max, graph_size)
    end
end

-- Plot Histogram (the data provided _is_ histogram data. it doesn't compute the histogram of your data)
--- @param label            string
--- @param values_or_getter table|fun(data:table, i:int)  # 1-based table or a function
--- @param data?            table                         # 1-based table
--- @param values_count     int
--- @param values_offset?   int                           # Defaults to 0
--- @param overlay_text?    string
--- @param scale_min?       float                         # Defaults to FLT_MAX
--- @param scale_max?       float                         # Defaults to FLT_MAX
--- @param graph_size?      ImVec2                        # Defaults to ImVec2(0, 0)
--- @param stride?          int                           # Defaults to 1
function ImGui.PlotHistogram(label, values_or_getter, data, values_count, values_offset, overlay_text, scale_min, scale_max, graph_size, stride)
    if values_offset == nil then values_offset = 0         end
    if scale_min     == nil then scale_min  = FLT_MAX      end
    if scale_max     == nil then scale_max  = FLT_MAX      end
    if graph_size    == nil then graph_size = ImVec2(0, 0) end
    if stride        == nil then stride     = 1            end

    if type(values_or_getter) == "function" then
        ImGui.PlotEx(ImGuiPlotType.Histogram, label, values_or_getter, data, values_count, values_offset, overlay_text, scale_min, scale_max, graph_size)
    else
        data = ImGuiPlotArrayGetterData(values_or_getter, stride)
        ImGui.PlotEx(ImGuiPlotType.Histogram, label, Plot_ArrayGetter, data, values_count, values_offset, overlay_text, scale_min, scale_max, graph_size)
    end
end

-------------------------------------------------------------------------------
-- [SECTION] MenuItem, BeginMenu, EndMenu, etc.
-------------------------------------------------------------------------------
-- - ImGuiMenuColumns [Internal]
-- - BeginMenuBar()
-- - EndMenuBar()
-- - BeginMainMenuBar()
-- - EndMainMenuBar()
-- - BeginMenu()
-- - EndMenu()
-- - MenuItemEx() [Internal]
-- - MenuItem()
-------------------------------------------------------------------------------

-- Helpers for internal use
--- @param spacing            float
--- @param window_reappearing bool
function MT.ImGuiMenuColumns:Update(spacing, window_reappearing)
    if window_reappearing then
        for i = 1, #self.Widths do self.Widths[i] = 0 end
    end
    self.Spacing = spacing
    self:CalcNextTotalWidth(true)
    for i = 1, #self.Widths do self.Widths[i] = 0 end
    self.TotalWidth = self.NextTotalWidth
    self.NextTotalWidth = 0
end

--- @param update_offsets bool
function MT.ImGuiMenuColumns:CalcNextTotalWidth(update_offsets)
    local offset = 0
    local want_spacing = false
    for i = 1, #self.Widths do
        local width = self.Widths[i]
        if want_spacing and width > 0 then
            offset = offset + self.Spacing
        end
        want_spacing = want_spacing or (width > 0)
        if update_offsets then
            if i == 2 then self.OffsetLabel = offset end
            if i == 3 then self.OffsetShortcut = offset end
            if i == 4 then self.OffsetMark = offset end
        end
        offset = offset + width
    end
    self.NextTotalWidth = offset
end

--- @param w_icon     float
--- @param w_label    float
--- @param w_shortcut float
--- @param w_mark     float
function MT.ImGuiMenuColumns:DeclColumns(w_icon, w_label, w_shortcut, w_mark)
    self.Widths[1] = ImMax(self.Widths[1], (ImU16)(w_icon))
    self.Widths[2] = ImMax(self.Widths[2], (ImU16)(w_label))
    self.Widths[3] = ImMax(self.Widths[3], (ImU16)(w_shortcut))
    self.Widths[4] = ImMax(self.Widths[4], (ImU16)(w_mark))
    self:CalcNextTotalWidth(false)
    return ImMax(self.TotalWidth, self.NextTotalWidth)
end

-- FIXME: Provided a rectangle perhaps e.g. a BeginMenuBarEx() could be used anywhere..
-- Currently the main responsibility of this function being to setup clip-rect + horizontal layout + menu navigation layer.
-- Ideally we also want this to be responsible for claiming space out of the main window scrolling rectangle, in which case ImGuiWindowFlags.MenuBar will become unnecessary.
-- Then later the same system could be used for multiple menu-bars, scrollbars, side-bars.
function ImGui.BeginMenuBar()
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end
    if bit32.band(window.Flags, ImGuiWindowFlags.MenuBar) == 0 then
        return false
    end

    IM_ASSERT(not window.DC.MenuBarAppending)
    ImGui.BeginGroup() -- Backup position on layer 0 // FIXME: Misleading to use a group for that backup/restore
    ImGui.PushID("##MenuBar")

    -- We don't clip with current window clipping rectangle as it is already set to the area below. However we clip with window full rect.
    -- We remove 1 worth of rounding to Max.x to that text in long menus and small windows don't tend to display over the lower-right rounded area, which looks particularly glitchy.
    local border_top = ImMax(IM_ROUND(window.WindowBorderSize * 0.5 - window.TitleBarHeight), 0.0)
    local border_half = IM_ROUND(window.WindowBorderSize * 0.5)
    local bar_rect = window:MenuBarRect()
    local clip_rect = ImRect(ImFloor(bar_rect.Min.x + border_half), ImFloor(bar_rect.Min.y + border_top), ImFloor(ImMax(bar_rect.Min.x, bar_rect.Max.x - ImMax(window.WindowRounding, border_half))), ImFloor(bar_rect.Max.y))
    clip_rect:ClipWith(window.OuterRectClipped)
    ImGui.PushClipRect(clip_rect.Min, clip_rect.Max, false)

    -- We overwrite CursorMaxPos because BeginGroup sets it to CursorPos (essentially the .EmitItem hack in EndMenuBar() would need something analogous here, maybe a BeginGroupEx() with flags).
    ImVec2_Copy(window.DC.CursorPos, ImVec2(bar_rect.Min.x + window.DC.MenuBarOffset.x, bar_rect.Min.y + window.DC.MenuBarOffset.y))
    ImVec2_Copy(window.DC.CursorMaxPos, window.DC.CursorPos)
    window.DC.LayoutType = ImGuiLayoutType.Horizontal
    window.DC.IsSameLine = false
    window.DC.NavLayerCurrent = ImGuiNavLayer.Menu
    window.DC.MenuBarAppending = true
    ImGui.AlignTextToFramePadding()

    return true
end

function ImGui.EndMenuBar()
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end
    local g = GImGui

    IM_ASSERT(bit32.band(window.Flags, ImGuiWindowFlags.MenuBar) ~= 0)
    IM_ASSERT(window.DC.MenuBarAppending)

    -- Nav: When a move request within one of our child menu failed, capture the request to navigate among our siblings.
    if ImGui.NavMoveRequestButNoResultYet() and (g.NavMoveDir == ImGuiDir.Left or g.NavMoveDir == ImGuiDir.Right) and bit32.band(g.NavWindow.Flags, ImGuiWindowFlags.ChildMenu) ~= 0 then
        -- Try to find out if the request is for one of our child menu
        local nav_earliest_child = g.NavWindow
        while nav_earliest_child.ParentWindow and bit32.band(nav_earliest_child.ParentWindow.Flags, ImGuiWindowFlags.ChildMenu) ~= 0 do
            nav_earliest_child = nav_earliest_child.ParentWindow
        end
        if nav_earliest_child.ParentWindow == window and nav_earliest_child.DC.ParentLayoutType == ImGuiLayoutType.Horizontal and bit32.band(g.NavMoveFlags, ImGuiNavMoveFlags.Forwarded) == 0 then
            -- To do so we claim focus back, restore NavId and then process the movement request for yet another frame.
            -- This involve a one-frame delay which isn't very problematic in this situation. We could remove it by scoring in advance for multiple window (probably not worth bothering)
            local layer = ImGuiNavLayer.Menu
            IM_ASSERT(bit32.band(window.DC.NavLayersActiveMaskNext, bit32.lshift(1, layer)) ~= 0) -- Sanity check (FIXME: Seems unnecessary)
            ImGui.FocusWindow(window)
            ImGui.SetNavID(window.NavLastIds[layer], layer, 0, window.NavRectRel[layer])
            -- FIXME-NAV: How to deal with this when not using g.IO.ConfigNavCursorVisibleAuto?
            if g.NavCursorVisible then
                g.NavCursorVisible = false -- Hide nav cursor for the current frame so we don't see the intermediary selection. Will be set again
                g.NavCursorHideFrames = 2
            end
            g.NavHighlightItemUnderNav = true
            g.NavMousePosDirty = true
            ImGui.NavMoveRequestForward(g.NavMoveDir, g.NavMoveClipDir, g.NavMoveFlags, g.NavMoveScrollFlags) -- Repeat
        end
    else
        ImGui.NavMoveRequestTryWrapping(window, ImGuiNavMoveFlags.WrapX)
    end

    ImGui.PopClipRect()
    ImGui.PopID()
    window.DC.MenuBarOffset.x = window.DC.CursorPos.x - window.Pos.x -- Save horizontal position so next append can reuse it. This is kinda equivalent to a per-layer CursorPos.

    -- FIXME: Extremely confusing, cleanup by (a) working on WorkRect stack system (b) not using a Group confusingly here.
    local group_data = g.GroupStack:back()
    group_data.EmitItem = false
    local restore_cursor_max_pos = ImVec2()
    ImVec2_Copy(restore_cursor_max_pos, group_data.BackupCursorMaxPos)
    window.DC.IdealMaxPos.x = ImMax(window.DC.IdealMaxPos.x, window.DC.CursorMaxPos.x - window.Scroll.x) -- Convert ideal extents for scrolling layer equivalent.
    ImGui.EndGroup() -- Restore position on layer 0 // FIXME: Misleading to use a group for that backup/restore
    window.DC.LayoutType = ImGuiLayoutType.Vertical
    window.DC.IsSameLine = false
    window.DC.NavLayerCurrent = ImGuiNavLayer.Main
    window.DC.MenuBarAppending = false
    ImVec2_Copy(window.DC.CursorMaxPos, restore_cursor_max_pos)
end

-- Important: calling order matters!
-- FIXME: Somehow overlapping with docking tech.
-- FIXME: The "rect-cut" aspect of this could be formalized into a lower-level helper (rect-cut: https://halt.software/dead-simple-layouts)
--- @param name        string
--- @param viewport_p? ImGuiViewport
--- @param dir         ImGuiDir
--- @param axis_size   float
--- @param window_flags ImGuiWindowFlags
function ImGui.BeginViewportSideBar(name, viewport_p, dir, axis_size, window_flags)
    IM_ASSERT(dir ~= ImGuiDir.None)

    local bar_window = ImGui.FindWindowByName(name)
    local viewport = viewport_p or ImGui.GetMainViewport()
    if bar_window == nil or bar_window.BeginCount == 0 then
        -- Calculate and set window size/position
        local avail_rect = viewport:GetBuildWorkRect()
        local axis = (dir == ImGuiDir.Up or dir == ImGuiDir.Down) and ImGuiAxis.Y or ImGuiAxis.X
        local pos = ImVec2(avail_rect.Min.x, avail_rect.Min.y)
        if dir == ImGuiDir.Right or dir == ImGuiDir.Down then
            pos[axis] = avail_rect.Max[axis] - axis_size
        end
        local size = avail_rect:GetSize()
        size[axis] = axis_size
        ImGui.SetNextWindowPos(pos)
        ImGui.SetNextWindowSize(size)

        -- Report our size into work area (for next frame) using actual window size
        if dir == ImGuiDir.Up or dir == ImGuiDir.Left then
            viewport.BuildWorkInsetMin[axis] = viewport.BuildWorkInsetMin[axis] + axis_size
        elseif dir == ImGuiDir.Down or dir == ImGuiDir.Right then
            viewport.BuildWorkInsetMax[axis] = viewport.BuildWorkInsetMax[axis] + axis_size
        end
    end

    window_flags = bit32.bor(window_flags or 0, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoResize, ImGuiWindowFlags.NoMove, ImGuiWindowFlags.NoDocking)
    ImGui.SetNextWindowViewport(viewport.ID)
    ImGui.PushStyleVar(ImGuiStyleVar.WindowRounding, 0.0)
    ImGui.PushStyleVar(ImGuiStyleVar.WindowMinSize, ImVec2(0, 0)) -- Lift normal size constraint
    local _, is_open = ImGui.Begin(name, nil, window_flags)
    ImGui.PopStyleVar(2)

    return is_open
end

function ImGui.BeginMainMenuBar()
    local g = GImGui
    local viewport = ImGui.GetMainViewport()

    -- Notify of viewport change so GetFrameHeight() can be accurate in case of DPI change
    ImGui.SetCurrentViewport(nil, viewport)

    -- For the main menu bar, which cannot be moved, we honor g.Style.DisplaySafeAreaPadding to ensure text can be visible on a TV set.
    -- FIXME: This could be generalized as an opt-in way to clamp window.DC.CursorStartPos to avoid SafeArea?
    -- FIXME: Consider removing support for safe area down the line... it's messy. Nowadays consoles have support for TV calibration in OS settings.
    g.NextWindowData.MenuBarOffsetMinVal = ImVec2(g.Style.DisplaySafeAreaPadding.x, ImMax(g.Style.DisplaySafeAreaPadding.y - g.Style.FramePadding.y, 0.0))
    local window_flags = bit32.bor(ImGuiWindowFlags.NoScrollbar, ImGuiWindowFlags.NoSavedSettings, ImGuiWindowFlags.MenuBar)
    local height = ImGui.GetFrameHeight()
    local is_open = ImGui.BeginViewportSideBar("##MainMenuBar", viewport, ImGuiDir.Up, height, window_flags)
    g.NextWindowData.MenuBarOffsetMinVal = ImVec2(0.0, 0.0)
    if not is_open then
        ImGui.End()
        return false
    end

    -- Temporarily disable _NoSavedSettings, in the off-chance that tables or child windows submitted within the menu-bar may want to use settings. (#8356)
    g.CurrentWindow.Flags = bit32.band(g.CurrentWindow.Flags, bit32.bnot(ImGuiWindowFlags.NoSavedSettings))
    ImGui.BeginMenuBar()
    return is_open
end

function ImGui.EndMainMenuBar()
    local g = GImGui
    IM_ASSERT_USER_ERROR_RET(g.CurrentWindow.DC.MenuBarAppending, "Calling EndMainMenuBar() not from a menu-bar!") -- Not technically testing that it is the main menu bar

    ImGui.EndMenuBar()
    g.CurrentWindow.Flags = bit32.bor(g.CurrentWindow.Flags, ImGuiWindowFlags.NoSavedSettings) -- Restore _NoSavedSettings (#8356)

    -- When the user has left the menu layer (typically: closed menus through activation of an item), we restore focus to the previous window
    -- FIXME: With this strategy we won't be able to restore a nil focus.
    if g.CurrentWindow == g.NavWindow and g.NavLayer == ImGuiNavLayer.Main and not g.NavAnyRequest and g.ActiveId == 0 then
        ImGui.FocusTopMostWindowUnderOne(g.NavWindow, nil, nil, bit32.bor(ImGuiFocusRequestFlags.UnlessBelowModal, ImGuiFocusRequestFlags.RestoreFocusedChild))
    end

    ImGui.End()
end

local function IsRootOfOpenMenuSet()
    local g = GImGui
    local window = g.CurrentWindow
    if (g.OpenPopupStack.Size <= g.BeginPopupStack.Size) or (bit32.band(window.Flags, ImGuiWindowFlags.ChildMenu) ~= 0) then
        return false
    end

    -- Initially we used 'upper_popup.OpenParentId == window.IDStack:back()' to differentiate multiple menu sets from each others
    -- (e.g. inside menu bar vs loose menu items) based on parent ID.
    -- This would however prevent the use of e.g. PushID() user code submitting menus.
    -- Previously this worked between popup and a first child menu because the first child menu always had the _ChildWindow flag,
    -- making hovering on parent popup possible while first child menu was focused - but this was generally a bug with other side effects.
    -- Instead we don't treat Popup specifically (in order to consistently support menu features in them), maybe the first child menu of a Popup
    -- doesn't have the _ChildWindow flag, and we rely on this IsRootOfOpenMenuSet() check to allow hovering between root window/popup and first child menu.
    -- In the end, lack of ID check made it so we could no longer differentiate between separate menu sets. To compensate for that, we at least check parent window nav layer.
    -- This fixes the most common case of menu opening on hover when moving between window content and menu bar. Multiple different menu sets in same nav layer would still
    -- open on hover, but that should be a lesser problem, because if such menus are close in proximity in window content then it won't feel weird and if they are far apart
    -- it likely won't be a problem anyone runs into.
    local upper_popup = g.OpenPopupStack.Data[g.BeginPopupStack.Size + 1]
    if window.DC.NavLayerCurrent ~= upper_popup.ParentNavLayer then
        return false
    end
    return upper_popup.Window and (bit32.band(upper_popup.Window.Flags, ImGuiWindowFlags.ChildMenu) ~= 0) and ImGui.IsWindowChildOf(upper_popup.Window, window, true, false)
end

--- @param label   string
--- @param icon?   string
--- @param enabled bool
function ImGui.BeginMenuEx(label, icon, enabled)
    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local style = g.Style
    local id = window:GetID(label)
    local menu_is_open = ImGui.IsPopupOpen(id, ImGuiPopupFlags.None)

    -- Sub-menus are ChildWindow so that mouse can be hovering across them (otherwise top-most popup menu would steal focus and not allow hovering on parent menu)
    -- The first menu in a hierarchy isn't so hovering doesn't get across (otherwise e.g. resizing borders with ImGuiButtonFlags.FlattenChildren would react), but top-most BeginMenu() will bypass that limitation.
    local window_flags = bit32.bor(ImGuiWindowFlags.ChildMenu, ImGuiWindowFlags.AlwaysAutoResize, ImGuiWindowFlags.NoMove, ImGuiWindowFlags.NoTitleBar, ImGuiWindowFlags.NoSavedSettings, ImGuiWindowFlags.NoNavFocus)
    if bit32.band(window.Flags, ImGuiWindowFlags.ChildMenu) ~= 0 then
        window_flags = bit32.bor(window_flags, ImGuiWindowFlags.ChildWindow)
    end

    -- If a menu with same the ID was already submitted, we will append to it, matching the behavior of Begin().
    -- We are relying on a O(N) search - so O(N log N) over the frame - which seems like the most efficient for the expected small amount of BeginMenu() calls per frame.
    -- If somehow this is ever becoming a problem we can switch to use e.g. ImGuiStorage mapping key to last frame used.
    if g.MenusIdSubmittedThisFrame:contains(id) then
        if menu_is_open then
            menu_is_open = ImGui.BeginPopupMenuEx(id, label, window_flags) -- menu_is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
        else
            g.NextWindowData:ClearFlags() -- we behave like Begin() and need to consume those values
        end
        return menu_is_open
    end

    -- Tag menu as used. Next time BeginMenu() with same ID is called it will append to existing menu
    g.MenusIdSubmittedThisFrame:push_back(id)

    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)

    -- Odd hack to allow hovering across menus of a same menu-set (otherwise we wouldn't be able to hover parent without always being a Child window)
    -- This is only done for items for the menu set and not the full parent window.
    local menuset_is_open = IsRootOfOpenMenuSet()
    if menuset_is_open then
        g.NextItemData.ItemFlagsSet = bit32.bor(g.NextItemData.ItemFlagsSet, ImGuiItemFlags.NoWindowHoverableCheck)
    end

    -- The reference position stored in popup_pos will be used by Begin() to find a suitable position for the child menu,
    -- However the final position is going to be different! It is chosen by FindBestWindowPosForPopup().
    -- e.g. Menus tend to overlap each other horizontally to amplify relative Z-ordering.
    local popup_pos
    local pos = ImVec2()
    ImVec2_Copy(pos, window.DC.CursorPos)
    ImGui.PushID(label)
    if not enabled then
        ImGui.BeginDisabled()
    end

    local pressed

    local backup_rounding = style.SelectableRounding
    style.SelectableRounding = style.MenuItemRounding
    local selectable_flags = bit32.bor(ImGuiSelectableFlags.SelectOnClick, ImGuiSelectableFlags.NoAutoClosePopups)
    local offsets = window.DC.MenuColumns
    if window.DC.LayoutType == ImGuiLayoutType.Horizontal then
        -- Menu inside a horizontal menu bar
        -- Selectable extend their highlight by half ItemSpacing in each direction.
        -- For ChildMenu, the popup position will be overwritten by the call to FindBestWindowPosForPopup() in Begin()
        window.DC.CursorPos.x = window.DC.CursorPos.x + IM_TRUNC(style.ItemSpacing.x * 0.5)
        ImGui.PushStyleVarX(ImGuiStyleVar.ItemSpacing, style.ItemSpacing.x * 2.0)
        local text_pos = ImVec2(window.DC.CursorPos.x + offsets.OffsetLabel, pos.y + window.DC.CurrLineTextBaseOffset)
        pressed = ImGui.Selectable("", menu_is_open, selectable_flags, label_size)
        -- TODO: ImGui.LogSetNextTextDecoration("[", "]")
        ImGui.RenderText(text_pos, label, 1, label_end, false)
        ImGui.PopStyleVar()
        window.DC.CursorPos.x = window.DC.CursorPos.x + IM_TRUNC(style.ItemSpacing.x * (-1.0 + 0.5)) -- -1 spacing to compensate the spacing added when Selectable() did a SameLine(). It would also work to call SameLine() ourselves after the PopStyleVar().
        popup_pos = ImVec2(pos.x - 1.0 - IM_TRUNC(style.ItemSpacing.x * 0.5), text_pos.y - style.FramePadding.y + window.MenuBarHeight)
    else
        -- Menu inside a regular/vertical menu
        -- (In a typical menu window where all items are BeginMenu() or MenuItem() calls, extra_w will always be 0.0f.
        --  Only when they are other items sticking out we're going to add spacing, yet only register minimum width into the layout system.)
        local icon_w
        if (icon and icon ~= "") then icon_w = ImGui.CalcTextSize(icon, nil).x else icon_w = 0.0 end
        local checkmark_w = IM_TRUNC(g.FontSize * 1.20)
        local min_w = offsets:DeclColumns(icon_w, label_size.x, 0.0, checkmark_w) -- Feedback to next frame
        local extra_w = ImMax(0.0, ImGui.GetContentRegionAvail().x - min_w)
        local text_pos = ImVec2(window.DC.CursorPos.x, pos.y + window.DC.CurrLineTextBaseOffset)
        pressed = ImGui.Selectable("", menu_is_open, bit32.bor(selectable_flags, ImGuiSelectableFlags.SpanAvailWidth), ImVec2(min_w, label_size.y))
        -- ImGui.LogSetNextTextDecoration("", ">")
        ImGui.RenderText(ImVec2(text_pos.x + offsets.OffsetLabel, text_pos.y), label, 1, label_end, false)
        if icon_w > 0.0 then
            --- @cast icon string
            ImGui.RenderText(ImVec2(text_pos.x + offsets.OffsetIcon, text_pos.y), icon)
        end
        ImGui.RenderArrow(window.DrawList, ImVec2(text_pos.x + offsets.OffsetMark + extra_w + g.FontSize * 0.30, text_pos.y), ImGui.GetColorU32(ImGuiCol.Text), ImGuiDir.Right)
        popup_pos = ImVec2(pos.x, text_pos.y - style.WindowPadding.y)
    end
    style.SelectableRounding = backup_rounding

    if not enabled then
        ImGui.EndDisabled()
    end

    -- Once dragged, release ActiveId + key ownership. This is to allow the idiom of mouse down a menu, dragging elsewhere, up on some other MenuItem(). (#8233, #9394)
    -- Could move logic into lower-level ImGuiButtonFlags.AutoReleaseActiveId + ImGuiButtonFlags.AutoReleaseKeyOwner? Easier once we get rid of the Selectable() middle-man here.
    if g.ActiveId == id and g.HoveredId ~= id and g.ActiveIdSource == ImGuiInputSource.Mouse and ImGui.IsMouseDragging(0) then
        ImGui.ClearActiveID()
        ImGui.SetKeyOwner(ImGuiKey.MouseLeft, ImGuiKeyOwner_NoOwner)
    end

    local hovered = g.HoveredId == id and enabled and not g.NavHighlightItemUnderNav

    local want_open = false
    local want_open_nav_init = false
    local want_close = false
    if window.DC.LayoutType == ImGuiLayoutType.Vertical then -- (window.Flags & (ImGuiWindowFlags.Popup|ImGuiWindowFlags.ChildMenu))
        -- Close menu when not hovering it anymore unless we are moving roughly in the direction of the menu
        -- Implement http://bjk5.com/post/44698559168/breaking-down-amazons-mega-dropdown to avoid using timers, so menus feels more reactive.
        local moving_toward_child_menu = false
        local child_popup = (g.BeginPopupStack.Size < g.OpenPopupStack.Size) and g.OpenPopupStack[g.BeginPopupStack.Size + 1] or nil -- Popup candidate (testing below)
        local child_menu_window = (child_popup and child_popup.Window and child_popup.Window.ParentWindow == window) and child_popup.Window or nil
        if g.HoveredWindow == window and child_menu_window ~= nil then
            local ref_unit = g.FontSize -- FIXME-DPI
            local child_dir = (window.Pos.x < child_menu_window.Pos.x) and 1.0 or -1.0
            local next_window_rect = child_menu_window:Rect()
            local ta = (g.IO.MousePos - g.IO.MouseDelta)
            local tb
            local tc
            if child_dir > 0.0 then
                tb = next_window_rect:GetTL()
                tc = next_window_rect:GetBL()
            else
                tb = next_window_rect:GetTR()
                tc = next_window_rect:GetBR()
            end
            local pad_farmost_h = ImClamp(ImFabs(ta.x - tb.x) * 0.30, ref_unit * 0.5, ref_unit * 2.5) -- Add a bit of extra slack.
            ta.x = ta.x + child_dir * -0.5
            tb.x = tb.x + child_dir * ref_unit
            tc.x = tc.x + child_dir * ref_unit
            tb.y = ta.y + ImMax((tb.y - pad_farmost_h) - ta.y, -ref_unit * 8.0) -- Triangle has maximum height to limit the slope and the bias toward large sub-menus
            tc.y = ta.y + ImMin((tc.y + pad_farmost_h) - ta.y, ref_unit * 8.0)
            moving_toward_child_menu = ImStd.ImTriangleContainsPoint(ta, tb, tc, g.IO.MousePos)
            -- ImGui.GetForegroundDrawList():AddTriangleFilled(ta, tb, tc, moving_toward_child_menu and IM_COL32(0, 128, 0, 128) or IM_COL32(128, 0, 0, 128)) -- [DEBUG]
        end

        -- The 'HovereWindow == window' check creates an inconsistency (e.g. moving away from menu slowly tends to hit same window, whereas moving away fast does not)
        -- But we also need to not close the top-menu menu when moving over void. Perhaps we should extend the triangle check to a larger polygon.
        -- (Remember to test this on BeginPopup("A")->BeginMenu("B") sequence which behaves slightly differently as B isn't a Child of A and hovering isn't shared.)
        if menu_is_open and not hovered and g.HoveredWindow == window and not moving_toward_child_menu and not g.NavHighlightItemUnderNav and g.ActiveId == 0 then
            want_close = true
        end

        -- Open
        -- (note: at this point 'hovered' actually includes the NavDisableMouseHover == false test)
        if not menu_is_open and pressed then -- Click/activate to open
            want_open = true
        elseif not menu_is_open and hovered and not moving_toward_child_menu then -- Hover to open
            want_open = true
        elseif not menu_is_open and hovered and g.HoveredIdTimer >= 0.30 and g.MouseStationaryTimer >= 0.30 then -- Hover to open (timer fallback)
            want_open = true
        end
        if g.NavId == id and g.NavMoveDir == ImGuiDir.Right then -- Nav-Right to open
            want_open = true
            want_open_nav_init = true
            ImGui.NavMoveRequestCancel()
            ImGui.SetNavCursorVisibleAfterMove()
        end
    else
        -- Menu bar
        if menu_is_open and pressed and menuset_is_open then -- Click an open menu again to close it
            want_close = true
            want_open = false
            menu_is_open = false
        elseif pressed or (hovered and menuset_is_open and not menu_is_open) then -- First click to open, then hover to open others
            want_open = true
        elseif g.NavId == id and g.NavMoveDir == ImGuiDir.Down then -- Nav-Down to open
            want_open = true
            ImGui.NavMoveRequestCancel()
        end
    end

    if not enabled then -- explicitly close if an open menu becomes disabled, facilitate users code a lot in pattern such as 'if (BeginMenu("options", has_object)) { ..use object.. }'
        want_close = true
    end
    if want_close and ImGui.IsPopupOpen(id, ImGuiPopupFlags.None) then
        ImGui.ClosePopupToLevel(g.BeginPopupStack.Size, true)
    end

    -- IMGUI_TEST_ENGINE_ITEM_INFO(id, label, g.LastItemData.StatusFlags | ImGuiItemStatusFlags_Openable | (menu_is_open ? ImGuiItemStatusFlags_Opened : 0))
    ImGui.PopID()

    if g.ActiveId == id and want_open then
        g.ActiveIdNoClearOnFocusLoss = true
    end

    if want_open and not menu_is_open and g.OpenPopupStack.Size > g.BeginPopupStack.Size then
        -- Don't reopen/recycle same menu level in the same frame if it is a different menu ID, first close the other menu and yield for a frame.
        ImGui.OpenPopup(label)
    elseif want_open then
        menu_is_open = true
        ImGui.OpenPopup(label, ImGuiPopupFlags.NoReopen) -- | (want_open_nav_init ? ImGuiPopupFlags.NoReopenAlwaysNavInit : 0))
    end

    if menu_is_open then
        local last_item_in_parent = ImGuiLastItemData()
        ImGuiLastItemData_Copy(last_item_in_parent, g.LastItemData)

        ImGui.SetNextWindowPos(popup_pos, ImGuiCond.Always) -- Note: misleading: the value will serve as reference for FindBestWindowPosForPopup(), not actual pos.
        ImGui.PushStyleVar(ImGuiStyleVar.ChildRounding, style.PopupRounding) -- First level will use _PopupRounding, subsequent will use _ChildRounding
        menu_is_open = ImGui.BeginPopupMenuEx(id, label, window_flags) -- menu_is_open may be 'false' when the popup is completely clipped (e.g. zero size display)
        ImGui.PopStyleVar()
        if menu_is_open then
            -- Implement what ImGuiPopupFlags.NoReopenAlwaysNavInit would do:
            -- Perform an init request in the case the popup was already open (via a previous mouse hover)
            if want_open and want_open_nav_init and not g.NavInitRequest then
                ImGui.FocusWindow(g.CurrentWindow, ImGuiFocusRequestFlags.UnlessBelowModal)
                ImGui.NavInitWindow(g.CurrentWindow, false)
            end

            -- Restore LastItemData so IsItemXXXX functions can work after BeginMenu()/EndMenu()
            -- (This fixes using IsItemClicked() and IsItemHovered(), but IsItemHovered() also relies on its support for ImGuiItemFlags.NoWindowHoverableCheck)
            ImGuiLastItemData_Copy(g.LastItemData, last_item_in_parent)
            if g.HoveredWindow == window then
                g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HoveredWindow)
            end
        end
    else
        g.NextWindowData:ClearFlags() -- We behave like Begin() and need to consume those values
    end

    return menu_is_open
end

--- @param label    string
--- @param enabled? bool
function ImGui.BeginMenu(label, enabled)
    if enabled == nil then enabled = true end

    return ImGui.BeginMenuEx(label, nil, enabled)
end

function ImGui.EndMenu()
    -- Nav: When a left move request our menu failed, close ourselves.
    local g = GImGui
    local window = g.CurrentWindow
    IM_ASSERT_USER_ERROR_RET(bit32.band(window.Flags, bit32.bor(ImGuiWindowFlags.Popup, ImGuiWindowFlags.ChildMenu)) == bit32.bor(ImGuiWindowFlags.Popup, ImGuiWindowFlags.ChildMenu), "Calling EndMenu() in wrong window!")

    local parent_window = window.ParentWindow -- Should always be ~= nil is we passed assert.
    if window.BeginCount == window.BeginCountPreviousFrame then
        if g.NavMoveDir == ImGuiDir.Left and ImGui.NavMoveRequestButNoResultYet() then
            if g.NavWindow and g.NavWindow.RootWindowForNav == window and parent_window.DC.LayoutType == ImGuiLayoutType.Vertical then
                ImGui.ClosePopupToLevel(g.BeginPopupStack.Size - 1, true)
                ImGui.NavMoveRequestCancel()
            end
        end
    end

    ImGui.EndPopup()
end

--- @param label     string
--- @param icon?     string
--- @param shortcut? string
--- @param selected? bool
--- @param enabled?  bool
function ImGui.MenuItemEx(label, icon, shortcut, selected, enabled)
    if selected == nil then selected = false end
    if enabled  == nil then enabled  = true  end

    local window = ImGui.GetCurrentWindow()
    if window.SkipItems then
        return false
    end

    local g = GImGui
    local style = g.Style
    local pos = ImVec2()
    ImVec2_Copy(pos, window.DC.CursorPos)
    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)

    -- See BeginMenuEx() for comments about this.
    local menuset_is_open = IsRootOfOpenMenuSet()
    if menuset_is_open then
        g.NextItemData.ItemFlagsSet = bit32.bor(g.NextItemData.ItemFlagsSet, ImGuiItemFlags.NoWindowHoverableCheck)
    end

    -- We've been using the equivalent of ImGuiSelectableFlags.SetNavIdOnHover on all Selectable() since early Nav system days (commit 43ee5d73),
    -- but I am unsure whether this should be kept at all. For now moved it to be an opt-in feature used by menus only.
    ImGui.PushID(label)
    if not enabled then
        ImGui.BeginDisabled()
    end

    local pressed

    -- We use ImGuiSelectableFlags.NoSetKeyOwner to allow down on one menu item, move, up on another.
    local backup_rounding = style.SelectableRounding
    style.SelectableRounding = style.MenuItemRounding
    local selectable_flags = bit32.bor(ImGuiSelectableFlags.SelectOnRelease, ImGuiSelectableFlags.SetNavIdOnHover)
    local offsets = window.DC.MenuColumns
    if window.DC.LayoutType == ImGuiLayoutType.Horizontal then
        -- Mimic the exact layout spacing of BeginMenu() to allow MenuItem() inside a menu bar, which is a little misleading but may be useful
        -- Note that in this situation: we don't render the shortcut, we render a highlight instead of the selected tick mark.
        window.DC.CursorPos.x = window.DC.CursorPos.x + IM_TRUNC(style.ItemSpacing.x * 0.5)
        local text_pos = ImVec2(window.DC.CursorPos.x + offsets.OffsetLabel, window.DC.CursorPos.y + window.DC.CurrLineTextBaseOffset)
        ImGui.PushStyleVarX(ImGuiStyleVar.ItemSpacing, style.ItemSpacing.x * 2.0)
        pressed = ImGui.Selectable("", selected, selectable_flags, ImVec2(label_size.x, 0.0))
        ImGui.PopStyleVar()
        if bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.Visible) ~= 0 then
            ImGui.RenderText(text_pos, label, 1, label_end, false)
        end
        window.DC.CursorPos.x = window.DC.CursorPos.x + IM_TRUNC(style.ItemSpacing.x * (-1.0 + 0.5)) -- -1 spacing to compensate the spacing added when Selectable() did a SameLine(). It would also work to call SameLine() ourselves after the PopStyleVar().
    else
        -- Menu item inside a vertical menu
        -- (In a typical menu window where all items are BeginMenu() or MenuItem() calls, extra_w will always be 0.0f.
        --  Only when they are other items sticking out we're going to add spacing, yet only register minimum width into the layout system.)
        local icon_w = 0.0
        if icon and icon ~= "" then
            icon_w = ImGui.CalcTextSize(icon, nil).x
        end
        local shortcut_w = 0.0
        if shortcut and shortcut ~= "" then
            shortcut_w = ImGui.CalcTextSize(shortcut, nil).x
        end
        local checkmark_w = IM_TRUNC(g.FontSize * 1.20) -- FIXME: Always accounted for, even in a menu with none, because 'selected' has no neutral setting.
        local min_w = offsets:DeclColumns(icon_w, label_size.x, shortcut_w, checkmark_w) -- Feedback for next frame
        local stretch_w = ImMax(0.0, ImGui.GetContentRegionAvail().x - min_w)
        local text_pos = ImVec2(pos.x, pos.y + window.DC.CurrLineTextBaseOffset)
        pressed = ImGui.Selectable("", false, bit32.bor(selectable_flags, ImGuiSelectableFlags.SpanAvailWidth), ImVec2(min_w, label_size.y))
        if bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.Visible) ~= 0 then
            ImGui.RenderText(text_pos + ImVec2(offsets.OffsetLabel, 0.0), label, 1, label_end, false)
            if icon_w > 0.0 then
                --- @cast icon string
                ImGui.RenderText(text_pos + ImVec2(offsets.OffsetIcon, 0.0), icon)
            end
            if shortcut_w > 0.0 then
                ImGui.PushStyleColor(ImGuiCol.Text, style.Colors[ImGuiCol.TextDisabled])
                -- ImGui.LogSetNextTextDecoration("(", ")")
                --- @cast shortcut string
                ImGui.RenderText(text_pos + ImVec2(offsets.OffsetShortcut + stretch_w, 0.0), shortcut, nil, nil, false)
                ImGui.PopStyleColor()
            end
            if selected then
                ImGui.RenderCheckMark(window.DrawList, text_pos + ImVec2(offsets.OffsetMark + stretch_w + g.FontSize * 0.40, g.FontSize * 0.134 * 0.5), ImGui.GetColorU32(ImGuiCol.Text), g.FontSize * 0.866)
            end
        end
    end
    style.SelectableRounding = backup_rounding

    -- Once dragged, release ActiveId + key ownership. This is to allow the idiom of mouse down a menu, dragging elsewhere, up on some other MenuItem(). (#8233, #9394)
    -- Could move logic into lower-level ImGuiButtonFlags_AutoReleaseActiveId + ImGuiButtonFlags_AutoReleaseKeyOwner? Easier once we get rid of the Selectable() middle-man here.
    local id = g.LastItemData.ID
    if g.ActiveId == id and g.HoveredId ~= id and g.ActiveIdSource == ImGuiInputSource.Mouse and ImGui.IsMouseDragging(0) then
        ImGui.ClearActiveID()
        ImGui.SetKeyOwner(ImGuiKey.MouseLeft, ImGuiKeyOwner_NoOwner)
    end

    -- IMGUI_TEST_ENGINE_ITEM_INFO()

    if not enabled then
        ImGui.EndDisabled()
    end
    ImGui.PopID()

    return pressed
end

--- @param label     string
--- @param shortcut? string
--- @param selected? bool
--- @param enabled?  bool
function ImGui.MenuItem(label, shortcut, selected, enabled)
    if ImGui.MenuItemEx(label, nil, shortcut, selected, enabled) then
        if selected ~= nil then
            selected = not selected
        end

        return true, selected
    end

    return false, selected
end



do --[[ [SECTION] Widgets: BeginTabBar, EndTabBar, etc. (was imgui_tabs.lua) ]]
--- Dear ImGui
-- Tab bars & tab items: 1:1 port of imgui_widgets.cpp [SECTION] Widgets: BeginTabBar/BeginTabItem (docking branch)
--
-- Port notes:
-- - tab_bar.Tabs is an ImVector of ImGuiTabItem tables (references). C++ pointer arithmetic on the array is replaced by
--   index lookups. tab_bar.LastTabItemIdx and tab orders are 0-based like upstream.
-- - Tab names are stored on the tab itself (tab.Name) instead of tab_bar.TabsNames.
-- - ImGui.BeginTabItem(label, p_open, flags) returns `visible, p_open`.

local MT = ImGui.GetMetatables()

local GImGui
local function SyncContext() GImGui = ImGui.GetCurrentContext() end

local function ImLinearSweep(current, target, speed)
    if current < target then return ImMin(current + speed, target) end
    if current > target then return ImMax(current - speed, target) end
    return current
end

local function TabItemGetSectionIdx(tab)
    if bit32.band(tab.Flags, ImGuiTabItemFlags.Leading) ~= 0 then return 0 end
    if bit32.band(tab.Flags, ImGuiTabItemFlags.Trailing) ~= 0 then return 2 end
    return 1
end

-- Stable sorts (C++ ImQsort is not stable, but the comparers are total orders in practice)
local function SortTabsBySection(tab_bar)
    table.sort(tab_bar.Tabs.Data, function(a, b)
        if a == nil or b == nil then return false end
        local sa, sb = TabItemGetSectionIdx(a), TabItemGetSectionIdx(b)
        if sa ~= sb then return sa < sb end
        return a.IndexDuringLayout < b.IndexDuringLayout
    end)
end

local function SortTabsByBeginOrder(tab_bar)
    local data = tab_bar.Tabs.Data
    if not data then return end
    local arr = {}
    for i = 1, tab_bar.Tabs.Size do arr[i] = data[i] end
    table.sort(arr, function(a, b) return a.BeginOrder < b.BeginOrder end)
    for i = 1, tab_bar.Tabs.Size do data[i] = arr[i] end
end

-- Scrolling happens only in the central section (leading/trailing sections are not scrolling)
local function TabBarCalcScrollableWidth(tab_bar, sections)
    return tab_bar.BarRect:GetWidth() - sections[1].Width - sections[3].Width - sections[2].Spacing
end

-- TabCount: Number of tabs in this section.
-- Width: Sum of width of tabs in this section (after shrinking down)
-- Spacing: Horizontal spacing at the end of the section.
local function ImGuiTabBarSection() return { TabCount = 0, Width = 0.0, WidthAfterShrinkMinWidth = 0.0, Spacing = 0.0 } end

-- Shrink excess width from a set of item, by removing width from the larger items first.
-- Set items Width to -1.0f to disable shrinking this item.
-- items: 1-based array of ImGuiShrinkWidthItem, `first` = 1-based index of first item, `count` items
function ImGui.ShrinkWidths(items, first, count, width_excess, width_min)
    if count <= 0 then return end
    if count == 1 then
        local it = items[first]
        if it.Width >= 0.0 then it.Width = ImMax(it.Width - width_excess, width_min) end
        return
    end
    -- Sort largest first, smallest last.
    local slice = {}
    for n = 1, count do slice[n] = items[first + n - 1] end
    table.sort(slice, function(a, b)
        if a.Width ~= b.Width then return a.Width > b.Width end
        return a.Index > b.Index -- ShrinkWidthItemComparer: b->Index - a->Index (Width compared exactly: upstream's (int) truncation isn't a strict weak order, which table.sort rejects)
    end)
    for n = 1, count do items[first + n - 1] = slice[n] end
    local it = slice
    local count_same_width = 1
    while width_excess > 0.001 and count_same_width < count do
        while count_same_width < count and it[1].Width <= it[count_same_width + 1].Width do
            count_same_width = count_same_width + 1
        end
        local max_width_to_remove_per_item = (count_same_width < count and it[count_same_width + 1].Width >= 0.0)
            and (it[1].Width - it[count_same_width + 1].Width) or (it[1].Width - 1.0)
        max_width_to_remove_per_item = ImMin(it[1].Width - width_min, max_width_to_remove_per_item)
        if max_width_to_remove_per_item <= 0.0 then break end
        local base_width_to_remove_per_item = ImMin(width_excess / count_same_width, max_width_to_remove_per_item)
        for item_n = 1, count_same_width do
            local w = ImMin(base_width_to_remove_per_item, it[item_n].Width - width_min)
            it[item_n].Width = it[item_n].Width - w
            width_excess = width_excess - w
        end
    end

    -- Round width and redistribute remainder
    -- Ensure that e.g. the right-most tab of a shrunk tab-bar always reaches exactly at the same distance from the right-most edge of the tab bar separator.
    width_excess = 0.0
    for n = 1, count do
        local width_rounded = ImTrunc(it[n].Width)
        width_excess = width_excess + it[n].Width - width_rounded
        it[n].Width = width_rounded
    end
    local guard = 0
    while width_excess > 0.0 and guard < 10000 do
        guard = guard + 1
        local progressed = false
        for n = 1, count do
            if width_excess <= 0.0 then break end
            local width_to_add = ImMin(it[n].InitialWidth - it[n].Width, 1.0)
            if width_to_add > 0 then progressed = true end
            it[n].Width = it[n].Width + width_to_add
            width_excess = width_excess - width_to_add
        end
        if not progressed then break end
    end
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: BeginTabBar, EndTabBar, etc.
-------------------------------------------------------------------------------
-- - BeginTabBar()
-- - BeginTabBarEx() [Internal]
-- - EndTabBar()
-- - TabBarLayout() [Internal]
-- - TabBarCalcTabID() [Internal]
-- - TabBarCalcMaxTabWidth() [Internal]
-- - TabBarFindTabById() [Internal]
-- - TabBarFindTabByOrder() [Internal]
-- - TabBarFindMostRecentlySelectedTabForActiveWindow() [Internal]
-- - TabBarGetCurrentTab() [Internal]
-- - TabBarGetTabName() [Internal]
-- - TabBarAddTab() [Internal]
-- - TabBarRemoveTab() [Internal]
-- - TabBarCloseTab() [Internal]
-- - TabBarScrollClamp() [Internal]
-- - TabBarScrollToTab() [Internal]
-- - TabBarQueueFocus() [Internal]
-- - TabBarQueueReorder() [Internal]
-- - TabBarProcessReorderFromMousePos() [Internal]
-- - TabBarProcessReorder() [Internal]
-- - TabBarScrollingButtons() [Internal]
-- - TabBarTabListPopupButton() [Internal]
-------------------------------------------------------------------------------

function ImGui.TabBarFindByID(id)
    SyncContext()
    return GImGui.TabBars:GetByKey(id)
end

-- Remove TabBar data (currently only used by TestEngine)
function ImGui.TabBarRemove(tab_bar)
    SyncContext()
    GImGui.TabBars:Remove(tab_bar.ID, tab_bar)
end

function ImGui.BeginTabBar(str_id, flags)
    if flags == nil then flags = 0 end
    SyncContext()
    local g = GImGui
    local window = g.CurrentWindow
    if window.SkipItems then return false end

    local id = window:GetID(str_id)
    local tab_bar = g.TabBars:GetOrAddByKey(id)
    local tab_bar_bb = ImRect(window.DC.CursorPos.x, window.DC.CursorPos.y, window.WorkRect.Max.x, window.DC.CursorPos.y + g.FontSize + g.Style.FramePadding.y * 2)
    tab_bar.ID = id
    tab_bar.SeparatorMinX = tab_bar_bb.Min.x - IM_TRUNC(window.WindowPadding.x * 0.5)
    tab_bar.SeparatorMaxX = tab_bar_bb.Max.x + IM_TRUNC(window.WindowPadding.x * 0.5)
    -- if (g.NavWindow and ImGui.IsWindowChildOf(g.NavWindow, window, false, false))
    flags = bit32.bor(flags, ImGuiTabBarFlags.IsFocused)
    return ImGui.BeginTabBarEx(tab_bar, tab_bar_bb, flags)
end

function ImGui.BeginTabBarEx(tab_bar, tab_bar_bb, flags)
    SyncContext()
    local g = GImGui
    local window = g.CurrentWindow
    if window.SkipItems then return false end

    IM_ASSERT(tab_bar.ID ~= 0)
    if bit32.band(flags, ImGuiTabBarFlags.DockNode) == 0 then -- Already done
        ImGui.PushOverrideID(tab_bar.ID)
    end

    -- Add to stack
    g.CurrentTabBarStack:push_back(tab_bar)
    g.CurrentTabBar = tab_bar
    tab_bar.Window = window

    -- Append with multiple BeginTabBar()/EndTabBar() pairs.
    ImVec2_Copy(tab_bar.BackupCursorPos, window.DC.CursorPos)
    if tab_bar.CurrFrameVisible == g.FrameCount then
        ImVec2_CopyV(window.DC.CursorPos, tab_bar.BarRect.Min.x, tab_bar.BarRect.Max.y + tab_bar.ItemSpacingY)
        tab_bar.BeginCount = tab_bar.BeginCount + 1
        return true
    end

    -- Ensure correct ordering when toggling ImGuiTabBarFlags.Reorderable flag, or when a new tab was added while being not reorderable
    if bit32.band(flags, ImGuiTabBarFlags.Reorderable) ~= bit32.band(tab_bar.Flags, ImGuiTabBarFlags.Reorderable)
        or (tab_bar.TabsAddedNew and bit32.band(flags, ImGuiTabBarFlags.Reorderable) == 0) then
        if bit32.band(flags, ImGuiTabBarFlags.DockNode) == 0 then -- FIXME: TabBar with DockNode can now be hybrid
            SortTabsByBeginOrder(tab_bar)
        end
    end
    tab_bar.TabsAddedNew = false

    -- Flags
    if bit32.band(flags, ImGuiTabBarFlags.FittingPolicyMask_) == 0 then
        flags = bit32.bor(flags, ImGuiTabBarFlags.FittingPolicyDefault_)
    end

    tab_bar.Flags = flags
    tab_bar.BarRect = ImRect(tab_bar_bb.Min, tab_bar_bb.Max)
    tab_bar.WantLayout = true -- Layout will be done on the first call to ItemTab()
    tab_bar.PrevFrameVisible = tab_bar.CurrFrameVisible
    tab_bar.CurrFrameVisible = g.FrameCount
    tab_bar.PrevTabsContentsHeight = tab_bar.CurrTabsContentsHeight
    tab_bar.CurrTabsContentsHeight = 0.0
    tab_bar.ItemSpacingY = g.Style.ItemSpacing.y
    ImVec2_Copy(tab_bar.FramePadding, g.Style.FramePadding)
    tab_bar.TabsActiveCount = 0
    tab_bar.LastTabItemIdx = -1
    tab_bar.BeginCount = 1

    -- Set cursor pos in a way which only be used in the off-chance the user erroneously submits item before BeginTabItem(): items will overlap
    ImVec2_CopyV(window.DC.CursorPos, tab_bar.BarRect.Min.x, tab_bar.BarRect.Max.y + tab_bar.ItemSpacingY)

    -- Draw separator
    -- (it would be misleading to draw this in EndTabBar() suggesting that it may be drawn over tabs, as tab bar are appendable)
    local col = ImGui.GetColorU32(bit32.band(flags, ImGuiTabBarFlags.IsFocused) ~= 0 and ImGuiCol.TabSelected or ImGuiCol.TabDimmedSelected)
    if g.Style.TabBarBorderSize > 0.0 then
        local y = tab_bar.BarRect.Max.y
        window.DrawList:AddRectFilled(ImVec2(tab_bar.SeparatorMinX, y - g.Style.TabBarBorderSize), ImVec2(tab_bar.SeparatorMaxX, y), col)
    end
    return true
end

function ImGui.EndTabBar()
    SyncContext()
    local g = GImGui
    local window = g.CurrentWindow
    if window.SkipItems then return end

    local tab_bar = g.CurrentTabBar
    IM_ASSERT(tab_bar ~= nil, "Mismatched BeginTabBar()/EndTabBar()!")

    -- Fallback in case no TabItem have been submitted
    if tab_bar.WantLayout then ImGui.TabBarLayout(tab_bar) end

    -- Restore the last visible height if no tab is visible, this reduce vertical flicker/movement when a tabs gets removed without calling SetTabItemClosed().
    local tab_bar_appearing = (tab_bar.PrevFrameVisible + 1 < g.FrameCount)
    if tab_bar.VisibleTabWasSubmitted or tab_bar.VisibleTabId == 0 or tab_bar_appearing then
        tab_bar.CurrTabsContentsHeight = ImMax(window.DC.CursorPos.y - tab_bar.BarRect.Max.y, tab_bar.CurrTabsContentsHeight)
        window.DC.CursorPos.y = tab_bar.BarRect.Max.y + tab_bar.CurrTabsContentsHeight
    else
        window.DC.CursorPos.y = tab_bar.BarRect.Max.y + tab_bar.PrevTabsContentsHeight
    end
    if tab_bar.BeginCount > 1 then
        ImVec2_Copy(window.DC.CursorPos, tab_bar.BackupCursorPos)
    end

    tab_bar.LastTabItemIdx = -1
    if bit32.band(tab_bar.Flags, ImGuiTabBarFlags.DockNode) == 0 then -- Already done
        ImGui.PopID()
    end

    g.CurrentTabBarStack:pop_back()
    if g.CurrentTabBarStack.Size == 0 then g.CurrentTabBar = nil else g.CurrentTabBar = g.CurrentTabBarStack.Data[g.CurrentTabBarStack.Size] end
end

-- This is called only once a frame before by the first call to ItemTab()
-- The reason we're not calling it in BeginTabBar() is to leave a chance to the user to call the SetTabItemClosed() functions.
function ImGui.TabBarLayout(tab_bar)
    SyncContext()
    local g = GImGui
    tab_bar.WantLayout = false

    -- Track selected tab when resizing our parent down
    local scroll_to_selected_tab = (tab_bar.BarRectPrevWidth > tab_bar.BarRect:GetWidth())
    tab_bar.BarRectPrevWidth = tab_bar.BarRect:GetWidth()

    -- Garbage collect by compacting list
    -- Detect if we need to sort out tab list (e.g. in rare case where a tab changed section)
    local tabs = tab_bar.Tabs
    local tab_dst_n = 0
    local need_sort_by_section = false
    local sections = { ImGuiTabBarSection(), ImGuiTabBarSection(), ImGuiTabBarSection() } -- Layout sections: Leading, Central, Trailing (1-based: [1]=Leading,[2]=Central,[3]=Trailing)
    for tab_src_n = 0, tabs.Size - 1 do
        local tab = tabs.Data[tab_src_n + 1]
        if tab.LastFrameVisible < tab_bar.PrevFrameVisible or tab.WantClose then
            -- Remove tab
            if tab_bar.VisibleTabId == tab.ID then tab_bar.VisibleTabId = 0 end
            if tab_bar.SelectedTabId == tab.ID then tab_bar.SelectedTabId = 0 end
            if tab_bar.NextSelectedTabId == tab.ID then tab_bar.NextSelectedTabId = 0 end
        else
            if tab_dst_n ~= tab_src_n then tabs.Data[tab_dst_n + 1] = tab end
            tab.IndexDuringLayout = tab_dst_n

            -- We will need sorting if tabs have changed section (e.g. moved from one of Leading/Central/Trailing to another)
            local curr_tab_section_n = TabItemGetSectionIdx(tab)
            if tab_dst_n > 0 then
                local prev_tab = tabs.Data[tab_dst_n]
                local prev_tab_section_n = TabItemGetSectionIdx(prev_tab)
                if curr_tab_section_n == 0 and prev_tab_section_n ~= 0 then need_sort_by_section = true end
                if prev_tab_section_n == 2 and curr_tab_section_n ~= 2 then need_sort_by_section = true end
            end
            sections[curr_tab_section_n + 1].TabCount = sections[curr_tab_section_n + 1].TabCount + 1
            tab_dst_n = tab_dst_n + 1
        end
    end
    if tabs.Size ~= tab_dst_n then
        for i = tab_dst_n + 1, tabs.Size do tabs.Data[i] = nil end
        tabs.Size = tab_dst_n
    end

    if need_sort_by_section then SortTabsBySection(tab_bar) end

    -- Calculate spacing between sections
    local tab_spacing = g.Style.ItemInnerSpacing.x
    sections[1].Spacing = (sections[1].TabCount > 0 and (sections[2].TabCount + sections[3].TabCount) > 0) and tab_spacing or 0.0
    sections[2].Spacing = (sections[2].TabCount > 0 and sections[3].TabCount > 0) and tab_spacing or 0.0

    -- Setup next selected tab
    local scroll_to_tab_id = 0
    if tab_bar.NextScrollToTabId ~= 0 then
        scroll_to_tab_id = tab_bar.NextScrollToTabId
        tab_bar.NextScrollToTabId = 0
    end
    if tab_bar.NextSelectedTabId ~= 0 then
        tab_bar.SelectedTabId = tab_bar.NextSelectedTabId
        tab_bar.NextSelectedTabId = 0
        scroll_to_tab_id = tab_bar.SelectedTabId
    end

    -- Process order change request (we could probably process it when requested but it's just saner to do it in a single spot).
    if tab_bar.ReorderRequestTabId ~= 0 then
        if ImGui.TabBarProcessReorder(tab_bar) then
            if tab_bar.ReorderRequestTabId == tab_bar.SelectedTabId then
                scroll_to_tab_id = tab_bar.ReorderRequestTabId
            end
        end
        tab_bar.ReorderRequestTabId = 0
    end

    -- Tab List Popup (will alter tab_bar.BarRect and therefore the available width!)
    local tab_list_popup_button = bit32.band(tab_bar.Flags, ImGuiTabBarFlags.TabListPopupButton) ~= 0
    if tab_list_popup_button then
        local tab_to_select = ImGui.TabBarTabListPopupButton(tab_bar) -- NB: Will alter BarRect.Min.x!
        if tab_to_select then
            tab_bar.SelectedTabId = tab_to_select.ID
            scroll_to_tab_id = tab_to_select.ID
        end
    end

    -- Leading/Trailing tabs will be shrink only if central one aren't visible anymore, so layout the shrink data as: leading, trailing, central
    -- (whereas our tabs are stored as: leading, central, trailing)
    -- (shrink_buffer_indexes holds 0-based offsets)
    local shrink_buffer_indexes = { 0, sections[1].TabCount + sections[3].TabCount, sections[1].TabCount }
    local swb = g.ShrinkWidthBuffer
    swb:resize(tabs.Size)
    for i = 1, tabs.Size do if swb.Data[i] == nil then swb.Data[i] = ImGuiShrinkWidthItem() end end

    -- Minimum shrink width
    local shrink_min_width = (bit32.band(tab_bar.Flags, ImGuiTabBarFlags.FittingPolicyMixed) ~= 0) and g.Style.TabMinWidthShrink or 1.0

    -- Compute ideal tabs widths + store them into shrink buffer
    local most_recently_selected_tab = nil
    local curr_section_n = -1
    local found_selected_tab_id = false
    for tab_n = 0, tabs.Size - 1 do
        local tab = tabs.Data[tab_n + 1]
        IM_ASSERT(tab.LastFrameVisible >= tab_bar.PrevFrameVisible)

        if (most_recently_selected_tab == nil or most_recently_selected_tab.LastFrameSelected < tab.LastFrameSelected) and bit32.band(tab.Flags, ImGuiTabItemFlags.Button) == 0 then
            most_recently_selected_tab = tab
        end
        if tab.ID == tab_bar.SelectedTabId then found_selected_tab_id = true end
        if scroll_to_tab_id == 0 and g.NavJustMovedToId == tab.ID then scroll_to_tab_id = tab.ID end

        -- Refresh tab width immediately, otherwise changes of style e.g. style.FramePadding.x would noticeably lag in the tab bar.
        -- Additionally, when using TabBarAddTab() to manipulate tab bar order we occasionally insert new tabs that don't have a width yet,
        -- and we cannot wait for the next BeginTabItem() call. We cannot compute this width within TabBarAddTab() because font size depends on the active window.
        local tab_name = ImGui.TabBarGetTabName(tab_bar, tab)
        local has_close_button_or_unsaved_marker = bit32.band(tab.Flags, ImGuiTabItemFlags.NoCloseButton) == 0 or bit32.band(tab.Flags, ImGuiTabItemFlags.UnsavedDocument) ~= 0
        tab.ContentWidth = (tab.RequestedWidth >= 0.0) and tab.RequestedWidth or ImGui.TabItemCalcSize(tab_name, has_close_button_or_unsaved_marker).x
        if bit32.band(tab.Flags, ImGuiTabItemFlags.Button) == 0 then
            tab.ContentWidth = ImMax(tab.ContentWidth, g.Style.TabMinWidthBase)
        end

        local section_n = TabItemGetSectionIdx(tab)
        local section = sections[section_n + 1]
        section.Width = section.Width + tab.ContentWidth + ((section_n == curr_section_n) and tab_spacing or 0.0)
        section.WidthAfterShrinkMinWidth = section.WidthAfterShrinkMinWidth + ImMin(tab.ContentWidth, shrink_min_width) + ((section_n == curr_section_n) and tab_spacing or 0.0)
        curr_section_n = section_n

        -- Store data so we can build an array sorted by width if we need to shrink tabs down
        local item = swb.Data[shrink_buffer_indexes[section_n + 1] + 1]
        shrink_buffer_indexes[section_n + 1] = shrink_buffer_indexes[section_n + 1] + 1
        item.Index = tab_n
        item.Width = tab.ContentWidth
        item.InitialWidth = tab.ContentWidth
        tab.Width = ImMax(tab.ContentWidth, 1.0)
    end

    -- Compute total ideal width (used for e.g. auto-resizing a window)
    local width_all_tabs_after_min_width_shrink = 0.0
    tab_bar.WidthAllTabsIdeal = 0.0
    for section_n = 1, 3 do
        tab_bar.WidthAllTabsIdeal = tab_bar.WidthAllTabsIdeal + sections[section_n].Width + sections[section_n].Spacing
        width_all_tabs_after_min_width_shrink = width_all_tabs_after_min_width_shrink + sections[section_n].WidthAfterShrinkMinWidth + sections[section_n].Spacing
    end

    -- Horizontal scrolling buttons
    -- - Important: note that TabBarScrollButtons() will alter BarRect.Max.x.
    -- - Selection skips buttons and might cross through sections if there are Tabs in Leading/Trailing sections.
    local can_scroll = bit32.band(tab_bar.Flags, ImGuiTabBarFlags.FittingPolicyScroll) ~= 0 or bit32.band(tab_bar.Flags, ImGuiTabBarFlags.FittingPolicyMixed) ~= 0
    local width_all_tabs_to_use_for_scroll = (bit32.band(tab_bar.Flags, ImGuiTabBarFlags.FittingPolicyScroll) ~= 0) and tab_bar.WidthAllTabs or width_all_tabs_after_min_width_shrink
    tab_bar.ScrollButtonEnabled = (width_all_tabs_to_use_for_scroll > tab_bar.BarRect:GetWidth() and tabs.Size > 1)
        and bit32.band(tab_bar.Flags, ImGuiTabBarFlags.NoTabListScrollingButtons) == 0 and can_scroll
    if tab_bar.ScrollButtonEnabled then
        local scroll_and_select_tab = ImGui.TabBarScrollingButtons(tab_bar)
        if scroll_and_select_tab then
            if bit32.band(scroll_and_select_tab.Flags, ImGuiTabItemFlags.Button) == 0 then
                tab_bar.SelectedTabId = scroll_and_select_tab.ID
            end
            scroll_to_tab_id = scroll_and_select_tab.ID
        end
    end
    if scroll_to_tab_id == 0 and scroll_to_selected_tab then
        scroll_to_tab_id = tab_bar.SelectedTabId
    end

    -- Shrink widths if full tabs don't fit in their allocated space
    local section_0_w = sections[1].Width + sections[1].Spacing
    local section_1_w = sections[2].Width + sections[2].Spacing
    local section_2_w = sections[3].Width + sections[3].Spacing
    local central_section_is_visible = (section_0_w + section_2_w) < tab_bar.BarRect:GetWidth()
    local width_excess
    if central_section_is_visible then
        width_excess = ImMax(section_1_w - (tab_bar.BarRect:GetWidth() - section_0_w - section_2_w), 0.0) -- Excess used to shrink central section
    else
        width_excess = (section_0_w + section_2_w) - tab_bar.BarRect:GetWidth() -- Excess used to shrink leading/trailing section
    end

    -- With ImGuiTabBarFlags.FittingPolicyScroll policy, we will only shrink leading/trailing if the central section is not visible anymore
    local can_shrink = bit32.band(tab_bar.Flags, ImGuiTabBarFlags.FittingPolicyShrink) ~= 0 or bit32.band(tab_bar.Flags, ImGuiTabBarFlags.FittingPolicyMixed) ~= 0
    if width_excess >= 1.0 and (can_shrink or not central_section_is_visible) then
        local shrink_data_count = central_section_is_visible and sections[2].TabCount or (sections[1].TabCount + sections[3].TabCount)
        local shrink_data_offset = central_section_is_visible and (sections[1].TabCount + sections[3].TabCount) or 0
        ImGui.ShrinkWidths(swb.Data, shrink_data_offset + 1, shrink_data_count, width_excess, shrink_min_width)

        -- Apply shrunk values into tabs and sections
        for tab_n = shrink_data_offset, shrink_data_offset + shrink_data_count - 1 do
            local item = swb.Data[tab_n + 1]
            local tab = tabs.Data[item.Index + 1]
            local shrinked_width = IM_TRUNC(item.Width)
            if shrinked_width >= 0.0 then
                shrinked_width = ImMax(1.0, shrinked_width)
                local section_n = TabItemGetSectionIdx(tab)
                sections[section_n + 1].Width = sections[section_n + 1].Width - (tab.Width - shrinked_width)
                tab.Width = shrinked_width
            end
        end
    end

    -- Layout all active tabs
    local section_tab_index = 0
    local tab_offset = 0.0
    tab_bar.WidthAllTabs = 0.0
    for section_n = 0, 2 do
        local section = sections[section_n + 1]
        if section_n == 2 then
            tab_offset = ImMin(ImMax(0.0, tab_bar.BarRect:GetWidth() - section.Width), tab_offset)
        end
        for tab_n = 0, section.TabCount - 1 do
            local tab = tabs.Data[section_tab_index + tab_n + 1]
            tab.Offset = tab_offset
            tab.NameOffset = -1
            tab_offset = tab_offset + tab.Width + ((tab_n < section.TabCount - 1) and g.Style.ItemInnerSpacing.x or 0.0)
        end
        tab_bar.WidthAllTabs = tab_bar.WidthAllTabs + ImMax(section.Width + section.Spacing, 0.0)
        tab_offset = tab_offset + section.Spacing
        section_tab_index = section_tab_index + section.TabCount
    end

    -- If we have lost the selected tab, select the next most recently active one
    local tab_bar_appearing = (tab_bar.PrevFrameVisible + 1 < g.FrameCount)
    if found_selected_tab_id == false and not tab_bar_appearing then
        tab_bar.SelectedTabId = 0
    end
    if tab_bar.SelectedTabId == 0 and tab_bar.NextSelectedTabId == 0 and most_recently_selected_tab ~= nil then
        tab_bar.SelectedTabId = most_recently_selected_tab.ID
        scroll_to_tab_id = tab_bar.SelectedTabId
    end

    -- Lock in visible tab
    tab_bar.VisibleTabId = tab_bar.SelectedTabId
    tab_bar.VisibleTabWasSubmitted = false

    -- CTRL+TAB can override visible tab temporarily
    if g.NavWindowingTarget ~= nil and g.NavWindowingTarget.DockNode and g.NavWindowingTarget.DockNode.TabBar == tab_bar then
        tab_bar.VisibleTabId = g.NavWindowingTarget.TabId
        scroll_to_tab_id = tab_bar.VisibleTabId
    end

    -- Apply request requests
    if scroll_to_tab_id ~= 0 then
        ImGui.TabBarScrollToTab(tab_bar, scroll_to_tab_id, sections)
    elseif tab_bar.ScrollButtonEnabled and ImGui.IsMouseHoveringRect(tab_bar.BarRect.Min, tab_bar.BarRect.Max, true) and ImGui.IsWindowContentHoverable(g.CurrentWindow) then
        local wheel = g.IO.MouseWheelRequestAxisSwap and g.IO.MouseWheel or g.IO.MouseWheelH
        local wheel_key = g.IO.MouseWheelRequestAxisSwap and ImGuiKey.MouseWheelY or ImGuiKey.MouseWheelX
        if ImGui.TestKeyOwner(wheel_key, tab_bar.ID) and wheel ~= 0.0 then
            local scroll_step = wheel * TabBarCalcScrollableWidth(tab_bar, sections) / 3.0
            tab_bar.ScrollingTargetDistToVisibility = 0.0
            tab_bar.ScrollingTarget = ImGui.TabBarScrollClamp(tab_bar, tab_bar.ScrollingTarget - scroll_step)
        end
        ImGui.SetKeyOwner(wheel_key, tab_bar.ID)
    end

    -- Update scrolling
    tab_bar.ScrollingAnim = ImGui.TabBarScrollClamp(tab_bar, tab_bar.ScrollingAnim)
    tab_bar.ScrollingTarget = ImGui.TabBarScrollClamp(tab_bar, tab_bar.ScrollingTarget)
    if tab_bar.ScrollingAnim ~= tab_bar.ScrollingTarget then
        -- Scrolling speed adjust itself so we can always reach our target in 1/3 seconds.
        -- Teleport if we are aiming far off the visible line
        tab_bar.ScrollingSpeed = ImMax(tab_bar.ScrollingSpeed, 70.0 * g.FontSize)
        tab_bar.ScrollingSpeed = ImMax(tab_bar.ScrollingSpeed, math.abs(tab_bar.ScrollingTarget - tab_bar.ScrollingAnim) / 0.3)
        local teleport = (tab_bar.PrevFrameVisible + 1 < g.FrameCount) or (tab_bar.ScrollingTargetDistToVisibility > 10.0 * g.FontSize)
        tab_bar.ScrollingAnim = teleport and tab_bar.ScrollingTarget or ImLinearSweep(tab_bar.ScrollingAnim, tab_bar.ScrollingTarget, g.IO.DeltaTime * tab_bar.ScrollingSpeed)
    else
        tab_bar.ScrollingSpeed = 0.0
    end
    tab_bar.ScrollingRectMinX = tab_bar.BarRect.Min.x + sections[1].Width + sections[1].Spacing
    tab_bar.ScrollingRectMaxX = tab_bar.BarRect.Max.x - sections[3].Width - sections[2].Spacing

    -- Actual layout in host window (we don't do it in BeginTabBar() so as not to waste an extra frame)
    local window = g.CurrentWindow
    ImVec2_Copy(window.DC.CursorPos, tab_bar.BarRect.Min)
    ImGui.ItemSize(ImVec2(tab_bar.WidthAllTabs, tab_bar.BarRect:GetHeight()), tab_bar.FramePadding.y)
    window.DC.IdealMaxPos.x = ImMax(window.DC.IdealMaxPos.x, tab_bar.BarRect.Min.x + tab_bar.WidthAllTabsIdeal)
end

-- Dockable windows uses Name/ID in the global namespace. Non-dockable items use the ID stack.
function ImGui.TabBarCalcTabID(tab_bar, label, docked_window)
    if docked_window ~= nil then
        IM_ASSERT(bit32.band(tab_bar.Flags, ImGuiTabBarFlags.DockNode) ~= 0)
        local id = docked_window.TabId
        ImGui.KeepAliveID(id)
        return id
    end
    return ImGui.GetCurrentContext().CurrentWindow:GetID(label)
end

function ImGui.TabBarCalcMaxTabWidth()
    return ImGui.GetCurrentContext().FontSize * 20.0
end

function ImGui.TabBarFindTabByID(tab_bar, tab_id)
    if tab_id ~= 0 then
        for n = 1, tab_bar.Tabs.Size do
            local tab = tab_bar.Tabs.Data[n]
            if tab.ID == tab_id then return tab end
        end
    end
    return nil
end

-- Order = visible order, not submission order! (which is tab.BeginOrder)
--- @param order int # 0-based visible order
function ImGui.TabBarFindTabByOrder(tab_bar, order)
    if order < 0 or order >= tab_bar.Tabs.Size then return nil end
    return tab_bar.Tabs.Data[order + 1]
end

--- @return int # 0-based order
function ImGui.TabBarGetTabOrder(tab_bar, tab)
    local i = tab_bar.Tabs:find_index(tab)
    return i and (i - 1) or -1
end

-- FIXME: See references to #2304 in TODO.txt
function ImGui.TabBarFindMostRecentlySelectedTabForActiveWindow(tab_bar)
    local most_recently_selected_tab = nil
    for n = 1, tab_bar.Tabs.Size do
        local tab = tab_bar.Tabs.Data[n]
        if most_recently_selected_tab == nil or most_recently_selected_tab.LastFrameSelected < tab.LastFrameSelected then
            if tab.Window and tab.Window.WasActive then most_recently_selected_tab = tab end
        end
    end
    return most_recently_selected_tab
end

function ImGui.TabBarGetCurrentTab(tab_bar)
    if tab_bar.LastTabItemIdx < 0 or tab_bar.LastTabItemIdx >= tab_bar.Tabs.Size then return nil end
    return tab_bar.Tabs.Data[tab_bar.LastTabItemIdx + 1]
end

function ImGui.TabBarGetTabName(tab_bar, tab)
    if tab.Window then return tab.Window.Name end
    if tab.Name == nil then return "N/A" end
    return tab.Name
end

function ImGui.TabBarGetTabPos(tab_bar, tab)
    if bit32.band(tab.Flags, ImGuiTabItemFlags.SectionMask_) == 0 then
        return tab_bar.BarRect.Min + ImVec2(IM_TRUNC(tab.Offset - tab_bar.ScrollingAnim), 0.0)
    end
    return tab_bar.BarRect.Min + ImVec2(tab.Offset, 0.0)
end

-- The purpose of this call is to register tab in advance so we can control their order at the time they appear.
-- Otherwise calling this is unnecessary as tabs are appending as needed by the BeginTabItem() function.
function ImGui.TabBarAddTab(tab_bar, tab_flags, window)
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(ImGui.TabBarFindTabByID(tab_bar, window.TabId) == nil)
    IM_ASSERT(g.CurrentTabBar ~= tab_bar) -- Can't work while the tab bar is active as our tab doesn't have an X offset yet, in theory we could/should test something like (tab_bar.CurrFrameVisible < g.FrameCount) but we'd need to solve why triggers the commented early-out assert in BeginTabBarEx() (probably dock node going from implicit to explicit in same frame)
    if not window.HasCloseButton then
        tab_flags = bit32.bor(tab_flags, ImGuiTabItemFlags.NoCloseButton) -- Set _NoCloseButton immediately because it will be used for first-frame width calculation.
    end
    local new_tab = ImGuiTabItem()
    new_tab.ID = window.TabId
    new_tab.Flags = tab_flags
    new_tab.LastFrameVisible = tab_bar.CurrFrameVisible -- Required so BeginTabBar() doesn't ditch the tab
    if new_tab.LastFrameVisible == -1 then new_tab.LastFrameVisible = g.FrameCount - 1 end
    new_tab.Window = window -- Required so tab bar layout can compute the tab width before tab submission
    tab_bar.Tabs:push_back(new_tab)
end

-- The *TabId fields are already set by the docking system _before_ the actual TabItem was created, so we clear them regardless.
function ImGui.TabBarRemoveTab(tab_bar, tab_id)
    local tab = ImGui.TabBarFindTabByID(tab_bar, tab_id)
    if tab then tab_bar.Tabs:erase(tab_bar.Tabs:find_index(tab)) end
    if tab_bar.VisibleTabId == tab_id then tab_bar.VisibleTabId = 0 end
    if tab_bar.SelectedTabId == tab_id then tab_bar.SelectedTabId = 0 end
    if tab_bar.NextSelectedTabId == tab_id then tab_bar.NextSelectedTabId = 0 end
end

-- Called on manual closure attempt
function ImGui.TabBarCloseTab(tab_bar, tab)
    if bit32.band(tab.Flags, ImGuiTabItemFlags.Button) ~= 0 then return end -- A button appended with TabItemButton().

    if bit32.band(tab.Flags, bit32.bor(ImGuiTabItemFlags.UnsavedDocument, ImGuiTabItemFlags.NoAssumedClosure)) == 0 then
        -- This will remove a frame of lag for selecting another tab on closure.
        -- However we don't run it in the case where the 'Unsaved' flag is set, so user gets a chance to fully undo the closure
        tab.WantClose = true
        if tab_bar.VisibleTabId == tab.ID then
            tab.LastFrameVisible = -1
            tab_bar.SelectedTabId = 0
            tab_bar.NextSelectedTabId = 0
        end
    else
        -- Actually select before expecting closure attempt (on an UnsavedDocument tab user is expect to e.g. show a popup)
        if tab_bar.VisibleTabId ~= tab.ID then ImGui.TabBarQueueFocus(tab_bar, tab) end
    end
end

function ImGui.TabBarScrollClamp(tab_bar, scrolling)
    scrolling = ImMin(scrolling, tab_bar.WidthAllTabs - tab_bar.BarRect:GetWidth())
    return ImMax(scrolling, 0.0)
end

-- Note: we may scroll to tab that are not selected! e.g. using keyboard arrow keys
function ImGui.TabBarScrollToTab(tab_bar, tab_id, sections)
    local tab = ImGui.TabBarFindTabByID(tab_bar, tab_id)
    if tab == nil then return end

    -- Clamp attempt to scroll to leading/trailing sections items.
    -- This could be done at the TabBarScrollingButtons() call site as well, but here works.
    if bit32.band(tab.Flags, ImGuiTabItemFlags.Leading) ~= 0 then
        tab = tab_bar.Tabs.Data[sections[1].TabCount + 1]
    elseif bit32.band(tab.Flags, ImGuiTabItemFlags.Trailing) ~= 0 then
        tab = tab_bar.Tabs.Data[sections[1].TabCount + sections[2].TabCount + 1]
    end
    if tab == nil or bit32.band(tab.Flags, ImGuiTabItemFlags.SectionMask_) ~= 0 then return end

    -- When scrolling to make Tab N+1 visible always make a bit of N visible to suggest more scrolling area (since we don't have a scrollbar)
    -- Disable the margin if the scrolling section is too small for the target tab: prefer displaying a maximum of the label.
    local g = ImGui.GetCurrentContext()
    local margin = ImClamp(tab_bar.ScrollingRectMaxX - tab_bar.ScrollingRectMinX - tab.Width, g.Style.ItemInnerSpacing.x, g.FontSize * 1.0)
    local order = ImGui.TabBarGetTabOrder(tab_bar, tab)

    -- Scrolling happens only in the central section (leading/trailing sections are not scrolling)
    local scrollable_width = TabBarCalcScrollableWidth(tab_bar, sections)

    -- We make all tabs positions all relative Sections[0].Width to make code simpler
    local tab_x1 = tab.Offset - sections[1].Width + ((order > sections[1].TabCount - 1) and -margin or 0.0)
    local tab_x2 = tab.Offset - sections[1].Width + tab.Width + ((order + 1 < tab_bar.Tabs.Size - sections[3].TabCount) and margin or 1.0)
    tab_bar.ScrollingTargetDistToVisibility = 0.0
    if tab_bar.ScrollingTarget > tab_x1 or (tab_x2 - tab_x1 >= scrollable_width) then
        -- Scroll to the left
        tab_bar.ScrollingTargetDistToVisibility = ImMax(tab_bar.ScrollingAnim - tab_x2, 0.0)
        tab_bar.ScrollingTarget = tab_x1
    elseif tab_bar.ScrollingTarget < tab_x2 - scrollable_width then
        -- Scroll to the right
        tab_bar.ScrollingTargetDistToVisibility = ImMax((tab_x1 - scrollable_width) - tab_bar.ScrollingAnim, 0.0)
        tab_bar.ScrollingTarget = tab_x2 - scrollable_width
    end
end

--- TabBarQueueFocus(tab_bar, tab) or TabBarQueueFocus(tab_bar, tab_name)
function ImGui.TabBarQueueFocus(tab_bar, tab)
    if type(tab) == "string" then
        IM_ASSERT(bit32.band(tab_bar.Flags, ImGuiTabBarFlags.DockNode) == 0) -- Only supported for manual/explicit tab bars
        tab_bar.NextSelectedTabId = ImGui.TabBarCalcTabID(tab_bar, tab, nil)
        return
    end
    tab_bar.NextSelectedTabId = tab.ID
end

function ImGui.TabBarQueueReorder(tab_bar, tab, offset)
    IM_ASSERT(offset ~= 0)
    IM_ASSERT(tab_bar.ReorderRequestTabId == 0)
    tab_bar.ReorderRequestTabId = tab.ID
    tab_bar.ReorderRequestOffset = offset
end

function ImGui.TabBarQueueReorderFromMousePos(tab_bar, src_tab, mouse_pos)
    local g = ImGui.GetCurrentContext()
    IM_ASSERT(tab_bar.ReorderRequestTabId == 0)
    if bit32.band(tab_bar.Flags, ImGuiTabBarFlags.Reorderable) == 0 then return end

    local tab_spacing = g.Style.ItemInnerSpacing.x
    local is_central_section = bit32.band(src_tab.Flags, ImGuiTabItemFlags.SectionMask_) == 0
    local bar_offset = tab_bar.BarRect.Min.x - (is_central_section and tab_bar.ScrollingTarget or 0)

    -- Count number of contiguous tabs we are crossing over
    local dir = ((bar_offset + src_tab.Offset) > mouse_pos.x) and -1 or 1
    local src_idx = ImGui.TabBarGetTabOrder(tab_bar, src_tab)
    local dst_idx = src_idx
    local i = src_idx
    while i >= 0 and i < tab_bar.Tabs.Size do
        -- Reordered tabs must share the same section
        local dst_tab = tab_bar.Tabs.Data[i + 1]
        if bit32.band(dst_tab.Flags, ImGuiTabItemFlags.NoReorder) ~= 0 then break end
        if bit32.band(dst_tab.Flags, ImGuiTabItemFlags.SectionMask_) ~= bit32.band(src_tab.Flags, ImGuiTabItemFlags.SectionMask_) then break end
        dst_idx = i

        -- Include spacing after tab, so when mouse cursor is between tabs we would not continue checking further tabs that are not hovered.
        local x1 = bar_offset + dst_tab.Offset - tab_spacing
        local x2 = bar_offset + dst_tab.Offset + dst_tab.Width + tab_spacing
        -- ImGui.GetForegroundDrawList():AddRect(ImVec2(x1, tab_bar.BarRect.Min.y), ImVec2(x2, tab_bar.BarRect.Max.y), IM_COL32(255, 0, 0, 255))
        if (dir < 0 and mouse_pos.x > x1) or (dir > 0 and mouse_pos.x < x2) then break end
        i = i + dir
    end

    if dst_idx ~= src_idx then
        ImGui.TabBarQueueReorder(tab_bar, src_tab, dst_idx - src_idx)
    end
end

function ImGui.TabBarProcessReorder(tab_bar)
    local tab1 = ImGui.TabBarFindTabByID(tab_bar, tab_bar.ReorderRequestTabId)
    if tab1 == nil or bit32.band(tab1.Flags, ImGuiTabItemFlags.NoReorder) ~= 0 then return false end

    -- IM_ASSERT(bit32.band(tab_bar.Flags, ImGuiTabBarFlags.Reorderable) ~= 0) -- <- this may happen when using debug tools
    local tab1_order = ImGui.TabBarGetTabOrder(tab_bar, tab1)
    local tab2_order = tab1_order + tab_bar.ReorderRequestOffset
    if tab2_order < 0 or tab2_order >= tab_bar.Tabs.Size then return false end

    -- Reordered tabs must share the same section
    -- (Note: TabBarQueueReorderFromMousePos() also has a similar test but since we allow direct calls to TabBarQueueReorder() we do it here too)
    local tab2 = tab_bar.Tabs.Data[tab2_order + 1]
    if bit32.band(tab2.Flags, ImGuiTabItemFlags.NoReorder) ~= 0 then return false end
    if bit32.band(tab1.Flags, ImGuiTabItemFlags.SectionMask_) ~= bit32.band(tab2.Flags, ImGuiTabItemFlags.SectionMask_) then return false end

    -- Move tab1 to tab2's position, shifting the tabs in between
    table.remove(tab_bar.Tabs.Data, tab1_order + 1)
    table.insert(tab_bar.Tabs.Data, tab2_order + 1, tab1)

    if bit32.band(tab_bar.Flags, ImGuiTabBarFlags.SaveSettings) ~= 0 then ImGui.MarkIniSettingsDirty() end
    return true
end

function ImGui.TabBarScrollingButtons(tab_bar)
    local g = ImGui.GetCurrentContext()
    local window = g.CurrentWindow

    local arrow_button_size = ImVec2(g.FontSize - 2.0, g.FontSize + g.Style.FramePadding.y * 2.0)
    local scrolling_buttons_width = arrow_button_size.x * 2.0

    local backup_cursor_pos = ImVec2(window.DC.CursorPos.x, window.DC.CursorPos.y)
    -- window.DrawList:AddRect(ImVec2(tab_bar.BarRect.Max.x - scrolling_buttons_width, tab_bar.BarRect.Min.y), ImVec2(tab_bar.BarRect.Max.x, tab_bar.BarRect.Max.y), IM_COL32(255,0,0,255))

    local select_dir = 0
    local tc = g.Style.Colors[ImGuiCol.Text]
    local arrow_col = ImVec4(tc.x, tc.y, tc.z, tc.w * 0.5)

    ImGui.PushStyleColor(ImGuiCol.Text, arrow_col)
    ImGui.PushStyleColor(ImGuiCol.Button, ImVec4(0, 0, 0, 0))
    ImGui.PushItemFlag(bit32.bor(ImGuiItemFlags.ButtonRepeat, ImGuiItemFlags.NoNav), true)
    local backup_repeat_delay = g.IO.KeyRepeatDelay
    local backup_repeat_rate = g.IO.KeyRepeatRate
    g.IO.KeyRepeatDelay = 0.250
    g.IO.KeyRepeatRate = 0.200
    local x = ImMax(tab_bar.BarRect.Min.x, tab_bar.BarRect.Max.x - scrolling_buttons_width)
    ImVec2_CopyV(window.DC.CursorPos, x, tab_bar.BarRect.Min.y)
    if ImGui.ArrowButtonEx("##<", ImGuiDir.Left, arrow_button_size, ImGuiButtonFlags.PressedOnClick) then select_dir = -1 end
    ImVec2_CopyV(window.DC.CursorPos, x + arrow_button_size.x, tab_bar.BarRect.Min.y)
    if ImGui.ArrowButtonEx("##>", ImGuiDir.Right, arrow_button_size, ImGuiButtonFlags.PressedOnClick) then select_dir = 1 end
    ImGui.PopItemFlag()
    ImGui.PopStyleColor(2)
    g.IO.KeyRepeatRate = backup_repeat_rate
    g.IO.KeyRepeatDelay = backup_repeat_delay

    local tab_to_scroll_to = nil
    if select_dir ~= 0 then
        local tab_item = ImGui.TabBarFindTabByID(tab_bar, tab_bar.SelectedTabId)
        if tab_item then
            local selected_order = ImGui.TabBarGetTabOrder(tab_bar, tab_item)
            local target_order = selected_order + select_dir

            -- Skip tab item buttons until another tab item is found or end is reached
            while tab_to_scroll_to == nil do
                -- If we are at the end of the list, still scroll to make our tab visible
                local idx = (target_order >= 0 and target_order < tab_bar.Tabs.Size) and target_order or selected_order
                tab_to_scroll_to = tab_bar.Tabs.Data[idx + 1]

                -- Cross through buttons
                -- (even if first/last item is a button, return it so we can update the scroll)
                if bit32.band(tab_to_scroll_to.Flags, ImGuiTabItemFlags.Button) ~= 0 then
                    target_order = target_order + select_dir
                    selected_order = selected_order + select_dir
                    if not (target_order < 0 or target_order >= tab_bar.Tabs.Size) then tab_to_scroll_to = nil end
                end
            end
        end
    end
    ImVec2_Copy(window.DC.CursorPos, backup_cursor_pos)
    tab_bar.BarRect.Max.x = tab_bar.BarRect.Max.x - (scrolling_buttons_width + 1.0)

    return tab_to_scroll_to
end

function ImGui.TabBarTabListPopupButton(tab_bar)
    local g = ImGui.GetCurrentContext()
    local window = g.CurrentWindow

    -- We use g.Style.FramePadding.y to match the square ArrowButton size
    local tab_list_popup_button_width = g.FontSize + g.Style.FramePadding.y
    local backup_cursor_pos = ImVec2(window.DC.CursorPos.x, window.DC.CursorPos.y)
    ImVec2_CopyV(window.DC.CursorPos, tab_bar.BarRect.Min.x - g.Style.FramePadding.y, tab_bar.BarRect.Min.y)
    tab_bar.BarRect.Min.x = tab_bar.BarRect.Min.x + tab_list_popup_button_width

    local tc = g.Style.Colors[ImGuiCol.Text]
    ImGui.PushStyleColor(ImGuiCol.Text, ImVec4(tc.x, tc.y, tc.z, tc.w * 0.5))
    ImGui.PushStyleColor(ImGuiCol.Button, ImVec4(0, 0, 0, 0))
    local open = ImGui.BeginCombo("##v", nil, bit32.bor(ImGuiComboFlags.NoPreview, ImGuiComboFlags.HeightLargest))
    ImGui.PopStyleColor(2)

    local tab_to_select = nil
    if open then
        for n = 1, tab_bar.Tabs.Size do
            local tab = tab_bar.Tabs.Data[n]
            if bit32.band(tab.Flags, ImGuiTabItemFlags.Button) == 0 then
                local tab_name = ImGui.TabBarGetTabName(tab_bar, tab)
                if ImGui.Selectable(tab_name, tab_bar.SelectedTabId == tab.ID) then
                    tab_to_select = tab
                end
            end
        end
        ImGui.EndCombo()
    end

    ImVec2_Copy(window.DC.CursorPos, backup_cursor_pos)
    return tab_to_select
end

-------------------------------------------------------------------------------
-- [SECTION] Widgets: BeginTabItem, EndTabItem, etc.
-------------------------------------------------------------------------------
-- - BeginTabItem()
-- - EndTabItem()
-- - TabItemButton()
-- - TabItemEx() [Internal]
-- - SetTabItemClosed()
-- - TabItemCalcSize() [Internal]
-- - TabItemBackground() [Internal]
-- - TabItemLabelAndCloseButton() [Internal]
-------------------------------------------------------------------------------

--- @return bool visible, bool? p_open
function ImGui.BeginTabItem(label, p_open, flags)
    if flags == nil then flags = 0 end
    local g = ImGui.GetCurrentContext()
    local window = g.CurrentWindow
    if window.SkipItems then return false, p_open end

    local tab_bar = g.CurrentTabBar
    IM_ASSERT(tab_bar ~= nil, "Needs to be called between BeginTabBar() and EndTabBar()!")
    IM_ASSERT(bit32.band(flags, ImGuiTabItemFlags.Button) == 0) -- BeginTabItem() Can't be used with button flags, use TabItemButton() instead!

    local ret
    ret, p_open = ImGui.TabItemEx(tab_bar, label, p_open, flags, nil)
    if ret and bit32.band(flags, ImGuiTabItemFlags.NoPushId) == 0 then
        local tab = tab_bar.Tabs.Data[tab_bar.LastTabItemIdx + 1]
        ImGui.PushOverrideID(tab.ID) -- We already hashed 'label' so push into the ID stack directly instead of doing another hash through PushID(label)
    end
    return ret, p_open
end

function ImGui.EndTabItem()
    local g = ImGui.GetCurrentContext()
    local window = g.CurrentWindow
    if window.SkipItems then return end

    local tab_bar = g.CurrentTabBar
    IM_ASSERT(tab_bar ~= nil, "Needs to be called between BeginTabBar() and EndTabBar()!")
    IM_ASSERT(tab_bar.LastTabItemIdx >= 0)
    local tab = tab_bar.Tabs.Data[tab_bar.LastTabItemIdx + 1]
    if bit32.band(tab.Flags, ImGuiTabItemFlags.NoPushId) == 0 then
        ImGui.PopID()
    end
end

function ImGui.TabItemButton(label, flags)
    if flags == nil then flags = 0 end
    local g = ImGui.GetCurrentContext()
    local window = g.CurrentWindow
    if window.SkipItems then return false end
    local tab_bar = g.CurrentTabBar
    IM_ASSERT(tab_bar ~= nil, "Needs to be called between BeginTabBar() and EndTabBar()!")
    return (ImGui.TabItemEx(tab_bar, label, nil, bit32.bor(flags, ImGuiTabItemFlags.Button, ImGuiTabItemFlags.NoReorder), nil))
end

function ImGui.TabItemSpacing(str_id, flags, width)
    local g = ImGui.GetCurrentContext()
    local window = g.CurrentWindow
    if window.SkipItems then return end
    local tab_bar = g.CurrentTabBar
    IM_ASSERT(tab_bar ~= nil, "Needs to be called between BeginTabBar() and EndTabBar()!")
    ImGui.SetNextItemWidth(width)
    ImGui.TabItemEx(tab_bar, str_id, nil, bit32.bor(flags or 0, ImGuiTabItemFlags.Button, ImGuiTabItemFlags.NoReorder, ImGuiTabItemFlags.Invisible), nil)
end

--- @return bool ret, bool? p_open
function ImGui.TabItemEx(tab_bar, label, p_open, flags, docked_window)
    -- Layout whole tab bar if not already done
    local g = ImGui.GetCurrentContext()
    if tab_bar.WantLayout then
        local backup_next_item_data = {}
        for k, v in pairs(g.NextItemData) do backup_next_item_data[k] = v end
        ImGui.TabBarLayout(tab_bar)
        for k, v in pairs(backup_next_item_data) do g.NextItemData[k] = v end
    end
    local window = g.CurrentWindow
    if window.SkipItems then return false, p_open end

    local style = g.Style
    local id = ImGui.TabBarCalcTabID(tab_bar, label, docked_window)

    -- If the user called us with p_open == false, we early out and don't render.
    -- We make a call to ItemAdd() so that attempts to use a contextual popup menu with an implicit ID won't use an older ID.
    if p_open ~= nil and not p_open then
        ImGui.ItemAdd(ImRect(), id, nil, ImGuiItemFlags.NoNav)
        return false, p_open
    end

    IM_ASSERT(p_open == nil or bit32.band(flags, ImGuiTabItemFlags.Button) == 0)
    IM_ASSERT(bit32.band(flags, bit32.bor(ImGuiTabItemFlags.Leading, ImGuiTabItemFlags.Trailing)) ~= bit32.bor(ImGuiTabItemFlags.Leading, ImGuiTabItemFlags.Trailing)) -- Can't use both Leading and Trailing

    -- Store into ImGuiTabItemFlags.NoCloseButton, also honor ImGuiTabItemFlags.NoCloseButton passed by user (although not documented)
    local has_p_open = (p_open ~= nil)
    if bit32.band(flags, ImGuiTabItemFlags.NoCloseButton) ~= 0 then
        has_p_open = false
    elseif not has_p_open then
        flags = bit32.bor(flags, ImGuiTabItemFlags.NoCloseButton)
    end

    -- Acquire tab data
    local tab = ImGui.TabBarFindTabByID(tab_bar, id)
    local tab_is_new = false
    if tab == nil then
        tab = ImGuiTabItem()
        tab_bar.Tabs:push_back(tab)
        tab.ID = id
        tab_bar.TabsAddedNew = true
        tab_is_new = true
    end
    tab_bar.LastTabItemIdx = ImGui.TabBarGetTabOrder(tab_bar, tab)

    -- Calculate tab contents size
    local size = ImGui.TabItemCalcSize(label, has_p_open or bit32.band(flags, ImGuiTabItemFlags.UnsavedDocument) ~= 0)
    tab.RequestedWidth = -1.0
    if bit32.band(g.NextItemData.HasFlags, ImGuiNextItemDataFlags.HasWidth) ~= 0 then
        size.x = g.NextItemData.Width
        tab.RequestedWidth = size.x
    end
    if tab_is_new then tab.Width = ImMax(1.0, size.x) end
    tab.ContentWidth = size.x
    tab.BeginOrder = tab_bar.TabsActiveCount
    tab_bar.TabsActiveCount = tab_bar.TabsActiveCount + 1

    local tab_bar_appearing = (tab_bar.PrevFrameVisible + 1 < g.FrameCount)
    local tab_bar_focused = bit32.band(tab_bar.Flags, ImGuiTabBarFlags.IsFocused) ~= 0
    local tab_appearing = (tab.LastFrameVisible + 1 < g.FrameCount)
    local tab_just_unsaved = bit32.band(flags, ImGuiTabItemFlags.UnsavedDocument) ~= 0 and bit32.band(tab.Flags, ImGuiTabItemFlags.UnsavedDocument) == 0
    local is_tab_button = bit32.band(flags, ImGuiTabItemFlags.Button) ~= 0
    tab.LastFrameVisible = g.FrameCount
    tab.Flags = flags
    tab.Window = docked_window

    -- Append name (port: stored on tab.Name)
    -- (regular tabs are permitted in a DockNode tab bar, but window tabs not permitted in a non-DockNode tab bar)
    if docked_window ~= nil then
        IM_ASSERT(bit32.band(tab_bar.Flags, ImGuiTabBarFlags.DockNode) ~= 0)
        tab.NameOffset = -1
        tab.Name = nil
    else
        tab.NameOffset = 0
        tab.Name = label
    end

    -- Update selected tab
    if not is_tab_button then
        if tab_appearing and bit32.band(tab_bar.Flags, ImGuiTabBarFlags.AutoSelectNewTabs) ~= 0 and tab_bar.NextSelectedTabId == 0 then
            if not tab_bar_appearing or tab_bar.SelectedTabId == 0 then
                ImGui.TabBarQueueFocus(tab_bar, tab) -- New tabs gets activated
            end
        end
        if bit32.band(flags, ImGuiTabItemFlags.SetSelected) ~= 0 and tab_bar.SelectedTabId ~= id then -- _SetSelected can only be passed on explicit tab bar
            ImGui.TabBarQueueFocus(tab_bar, tab)
        end
    end

    -- Lock visibility
    -- (Note: tab_contents_visible ~= tab_selected... because Ctrl+Tab operations may preview some tabs without selecting them!)
    local tab_contents_visible = (tab_bar.VisibleTabId == id)
    if tab_contents_visible then tab_bar.VisibleTabWasSubmitted = true end

    -- On the very first frame of a tab bar we let first tab contents be visible to minimize appearing glitches
    if not tab_contents_visible and tab_bar.SelectedTabId == 0 and tab_bar_appearing and docked_window == nil then
        if tab_bar.Tabs.Size == 1 and bit32.band(tab_bar.Flags, ImGuiTabBarFlags.AutoSelectNewTabs) == 0 then
            tab_contents_visible = true
        end
    end

    -- Note that tab_is_new is not necessarily the same as tab_appearing! When a tab bar stops being submitted
    -- and then gets submitted again, the tabs will have 'tab_appearing=true' but 'tab_is_new=false'.
    if tab_appearing and (not tab_bar_appearing or tab_is_new) then
        ImGui.ItemAdd(ImRect(), id, nil, ImGuiItemFlags.NoNav)
        if is_tab_button then return false, p_open end
        return tab_contents_visible, p_open
    end

    if tab_bar.SelectedTabId == id then tab.LastFrameSelected = g.FrameCount end

    -- Backup current layout position
    local backup_main_cursor_pos = ImVec2(window.DC.CursorPos.x, window.DC.CursorPos.y)

    -- Layout
    local is_central_section = bit32.band(tab.Flags, ImGuiTabItemFlags.SectionMask_) == 0
    size.x = tab.Width
    local pos = ImGui.TabBarGetTabPos(tab_bar, tab)
    ImVec2_Copy(window.DC.CursorPos, pos)
    local bb = ImRect(pos, pos + size)

    -- We don't have CPU clipping primitives to clip the CloseButton (until it becomes a texture), so need to add an extra draw call (temporary in the case of vertical animation)
    local want_clip_rect = is_central_section and (bb.Min.x < tab_bar.ScrollingRectMinX or bb.Max.x > tab_bar.ScrollingRectMaxX)
    if want_clip_rect then
        ImGui.PushClipRect(ImVec2(ImClamp(bb.Min.x, tab_bar.ScrollingRectMinX, tab_bar.ScrollingRectMaxX), bb.Min.y - 1), ImVec2(tab_bar.ScrollingRectMaxX, bb.Max.y), true)
    end

    local backup_cursor_max_pos = ImVec2(window.DC.CursorMaxPos.x, window.DC.CursorMaxPos.y)
    ImGui.ItemSize(bb:GetSize(), style.FramePadding.y)
    ImVec2_Copy(window.DC.CursorMaxPos, backup_cursor_max_pos)

    if not ImGui.ItemAdd(bb, id) then
        if want_clip_rect then ImGui.PopClipRect() end
        ImVec2_Copy(window.DC.CursorPos, backup_main_cursor_pos)
        return tab_contents_visible, p_open
    end

    -- Click to Select a tab
    local button_flags = bit32.bor(is_tab_button and ImGuiButtonFlags.PressedOnClickRelease or ImGuiButtonFlags.PressedOnClick, ImGuiButtonFlags.AllowOverlap)
    if g.DragDropActive and not ImGuiPayload_IsDataType(g.DragDropPayload, IMGUI_PAYLOAD_TYPE_WINDOW) then -- FIXME: May be an opt-in property of the payload to disable this
        button_flags = bit32.bor(button_flags, ImGuiButtonFlags.PressedOnDragDropHold)
    end
    local hovered, held, pressed
    if bit32.band(flags, ImGuiTabItemFlags.Invisible) ~= 0 then
        hovered, held, pressed = false, false, false
    else
        pressed, hovered, held = ImGui.ButtonBehavior(bb, id, button_flags)
    end
    if pressed and not is_tab_button then ImGui.TabBarQueueFocus(tab_bar, tab) end

    -- Transfer active id window so the active id is not owned by the dock host (as StartMouseMovingWindow()
    -- will only do it on the drag). This allows FocusWindow() to be more conservative in how it clears active id.
    if held and docked_window and g.ActiveId == id and g.ActiveIdIsJustActivated then
        g.ActiveIdWindow = docked_window
    end

    -- Drag and drop a single floating window node moves it
    local node = docked_window and docked_window.DockNode or nil
    local single_floating_window_node = node and node:IsFloatingNode() and (node.Windows.Size == 1)
    if held and single_floating_window_node and ImGui.IsMouseDragging(0, 0.0) then
        -- Move
        ImGui.StartMouseMovingWindow(docked_window)
    elseif held and not tab_appearing and ImGui.IsMouseDragging(0) then
        -- Drag and drop: re-order tabs
        local drag_dir = 0
        local drag_distance_from_edge_x = 0.0
        if not g.DragDropActive and (bit32.band(tab_bar.Flags, ImGuiTabBarFlags.Reorderable) ~= 0 or docked_window ~= nil) then
            -- While moving a tab it will jump on the other side of the mouse, so we also test for MouseDelta.x
            if g.IO.MouseDelta.x < 0.0 and g.IO.MousePos.x < bb.Min.x then
                drag_dir = -1
                drag_distance_from_edge_x = bb.Min.x - g.IO.MousePos.x
                ImGui.TabBarQueueReorderFromMousePos(tab_bar, tab, g.IO.MousePos)
            elseif g.IO.MouseDelta.x > 0.0 and g.IO.MousePos.x > bb.Max.x then
                drag_dir = 1
                drag_distance_from_edge_x = g.IO.MousePos.x - bb.Max.x
                ImGui.TabBarQueueReorderFromMousePos(tab_bar, tab, g.IO.MousePos)
            end
        end

        -- Extract a Dockable window out of it's tab bar
        local can_undock = docked_window ~= nil and bit32.band(docked_window.Flags, ImGuiWindowFlags.NoMove) == 0 and bit32.band(node.MergedFlags, ImGuiDockNodeFlags.NoUndocking) == 0
        if can_undock then
            -- We use a variable threshold to distinguish dragging tabs within a tab bar and extracting them out of the tab bar
            local undocking_tab = (g.DragDropActive and g.DragDropPayload.SourceId == id)
            if not undocking_tab then -- and (not g.IO.ConfigDockingWithShift or g.IO.KeyShift)
                local threshold_base = g.FontSize
                local threshold_x = threshold_base * 2.2
                local threshold_y = (threshold_base * 1.5) + ImClamp((math.abs(g.IO.MouseDragMaxDistanceAbs[0].x) - threshold_base * 2.0) * 0.20, 0.0, threshold_base * 4.0)
                -- ImGui.GetForegroundDrawList():AddRect(ImVec2(bb.Min.x - threshold_x, bb.Min.y - threshold_y), ImVec2(bb.Max.x + threshold_x, bb.Max.y + threshold_y), IM_COL32_WHITE) -- [DEBUG]

                local distance_from_edge_y = ImMax(bb.Min.y - g.IO.MousePos.y, g.IO.MousePos.y - bb.Max.y)
                if distance_from_edge_y >= threshold_y then undocking_tab = true end
                if drag_distance_from_edge_x > threshold_x then
                    if (drag_dir < 0 and ImGui.TabBarGetTabOrder(tab_bar, tab) == 0) or (drag_dir > 0 and ImGui.TabBarGetTabOrder(tab_bar, tab) == tab_bar.Tabs.Size - 1) then
                        undocking_tab = true
                    end
                end
            end

            if undocking_tab then
                -- Undock
                -- FIXME: refactor to share more code with e.g. StartMouseMovingWindow
                ImGui.DockContextQueueUndockWindow(g, docked_window)
                g.MovingWindow = docked_window
                ImGui.SetActiveID(g.MovingWindow.MoveId, g.MovingWindow)
                ImVec2_Copy(g.ActiveIdClickOffset, g.ActiveIdClickOffset - (g.MovingWindow.Pos - bb.Min))
                g.ActiveIdNoClearOnFocusLoss = true
                ImGui.SetActiveIdUsingAllKeyboardKeys()
            end
        end
    end

    -- Render tab shape
    local is_visible = bit32.band(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.Visible) ~= 0 and bit32.band(flags, ImGuiTabItemFlags.Invisible) == 0
    if is_visible then
        local display_draw_list = window.DrawList
        local col_idx
        if held or hovered then col_idx = ImGuiCol.TabHovered
        elseif tab_contents_visible then col_idx = tab_bar_focused and ImGuiCol.TabSelected or ImGuiCol.TabDimmedSelected
        else col_idx = tab_bar_focused and ImGuiCol.Tab or ImGuiCol.TabDimmed end
        ImGui.TabItemBackground(display_draw_list, bb, flags, ImGui.GetColorU32(col_idx))
        if tab_contents_visible and bit32.band(tab_bar.Flags, ImGuiTabBarFlags.DrawSelectedOverline) ~= 0 and style.TabBarOverlineSize > 0.0 then
            -- Might be moved to TabItemBackground() ?
            local tl = ImVec2(bb.Min.x, bb.Min.y + style.TabBarOverlineSize * 0.5)
            local tr = ImVec2(bb.Max.x, bb.Min.y + style.TabBarOverlineSize * 0.5)
            local overline_col = ImGui.GetColorU32(tab_bar_focused and ImGuiCol.TabSelectedOverline or ImGuiCol.TabDimmedSelectedOverline)
            if style.TabRounding > 0.0 then
                local rounding = style.TabRounding
                display_draw_list:PathArcToFast(tl + ImVec2(rounding, rounding), rounding, 7, 9)
                display_draw_list:PathArcToFast(tr + ImVec2(-rounding, rounding), rounding, 9, 11)
                display_draw_list:PathStroke(overline_col, style.TabBarOverlineSize)
            else
                display_draw_list:AddLine(tl, tr, overline_col, style.TabBarOverlineSize)
            end
        end
        ImGui.RenderNavCursor(bb, id)

        -- Select with right mouse button. This is so the common idiom for context menu automatically highlight the current widget.
        local hovered_unblocked = ImGui.IsItemHovered(ImGuiHoveredFlags.AllowWhenBlockedByPopup)
        if tab_bar.SelectedTabId ~= tab.ID and hovered_unblocked and (ImGui.IsMouseClicked(1) or ImGui.IsMouseReleased(1)) and not is_tab_button then
            ImGui.TabBarQueueFocus(tab_bar, tab)
        end

        if bit32.band(tab_bar.Flags, ImGuiTabBarFlags.NoCloseWithMiddleMouseButton) ~= 0 then
            flags = bit32.bor(flags, ImGuiTabItemFlags.NoCloseWithMiddleMouseButton)
        end

        -- Render tab label, process close button
        local close_button_id = has_p_open and ImGui.GetIDWithSeed("#CLOSE", nil, docked_window and docked_window.ID or id) or 0
        local label_flags = tab_just_unsaved and bit32.band(flags, bit32.bnot(ImGuiTabItemFlags.UnsavedDocument)) or flags
        local just_closed, text_clipped = ImGui.TabItemLabelAndCloseButton(display_draw_list, bb, label_flags, tab_bar.FramePadding, label, id, close_button_id, tab_contents_visible)
        if just_closed and has_p_open then
            p_open = false
            ImGui.TabBarCloseTab(tab_bar, tab)
        end

        -- Forward Hovered state so IsItemHovered() after Begin() can work (even though we are technically hovering our parent)
        -- That state is copied to window.DockTabItemStatusFlags by our caller.
        if docked_window and (hovered or g.HoveredId == close_button_id) then
            g.LastItemData.StatusFlags = bit32.bor(g.LastItemData.StatusFlags, ImGuiItemStatusFlags.HoveredWindow)
        end

        -- Tooltip
        -- (Won't work over the close button because ItemOverlap systems messes up with HoveredIdTimer-> seems ok)
        -- (We test IsItemHovered() to discard e.g. when another item is active or drag and drop over the tab bar, which g.HoveredId ignores)
        -- FIXME: This is a mess.
        -- FIXME: We may want disabled tab to still display the tooltip?
        if text_clipped and g.HoveredId == id and not held then
            if bit32.band(tab_bar.Flags, ImGuiTabBarFlags.NoTooltip) == 0 and bit32.band(tab.Flags, ImGuiTabItemFlags.NoTooltip) == 0 then
                local label_end = ImGui.FindRenderedTextEnd(label)
                ImGui.SetItemTooltip("%s", string.sub(label, 1, label_end - 1))
            end
        end
    end

    -- Restore main window position so user can draw there
    if want_clip_rect then ImGui.PopClipRect() end
    ImVec2_Copy(window.DC.CursorPos, backup_main_cursor_pos)

    if is_tab_button then return pressed, p_open end
    return tab_contents_visible, p_open
end

-- [Public] This is call is 100% optional but it allows to remove some one-frame glitches when a tab has been unexpectedly removed.
-- To use it to need to call the function SetTabItemClosed() between BeginTabBar() and EndTabBar().
-- Tabs closed by the close button will automatically be flagged to avoid this issue.
function ImGui.SetTabItemClosed(label)
    local g = ImGui.GetCurrentContext()
    local is_within_manual_tab_bar = g.CurrentTabBar and bit32.band(g.CurrentTabBar.Flags, ImGuiTabBarFlags.DockNode) == 0
    if is_within_manual_tab_bar then
        local tab_bar = g.CurrentTabBar
        local tab_id = ImGui.TabBarCalcTabID(tab_bar, label, nil)
        local tab = ImGui.TabBarFindTabByID(tab_bar, tab_id)
        if tab then tab.WantClose = true end -- Will be processed by next call to TabBarLayout()
    else
        local window = ImGui.FindWindowByName(label)
        if window and window.DockIsActive then
            local node = window.DockNode
            if node then
                local tab_id = ImGui.TabBarCalcTabID(node.TabBar, label, window)
                ImGui.TabBarRemoveTab(node.TabBar, tab_id)
                window.DockTabWantClose = true
            end
        end
    end
end

--- TabItemCalcSize(label, has_close_button_or_unsaved_marker) or TabItemCalcSize(window)
function ImGui.TabItemCalcSize(label, has_close_button_or_unsaved_marker)
    if type(label) == "table" then
        local window = label
        return ImGui.TabItemCalcSize(window.Name, window.HasCloseButton or bit32.band(window.Flags, ImGuiWindowFlags.UnsavedDocument) ~= 0)
    end
    local g = ImGui.GetCurrentContext()
    local label_size = ImGui.CalcTextSize(label, nil, true)
    local size = ImVec2(label_size.x + g.Style.FramePadding.x, label_size.y + g.Style.FramePadding.y * 2.0)
    if has_close_button_or_unsaved_marker then
        size.x = size.x + g.Style.FramePadding.x + (g.Style.ItemInnerSpacing.x + g.FontSize) -- We use Y intentionally to fit the close button circle.
    else
        size.x = size.x + g.Style.FramePadding.x + 1.0
    end
    return ImVec2(ImMin(size.x, ImGui.TabBarCalcMaxTabWidth()), size.y)
end

function ImGui.TabItemBackground(draw_list, bb, flags, col)
    -- While rendering tabs, we trim 1 pixel off the top of our bounding box so they can fit within a regular frame height while looking "detached" from it.
    local g = ImGui.GetCurrentContext()
    local width = bb:GetWidth()
    IM_ASSERT(width > 0.0)
    local rounding = ImMax(0.0, ImMin(bit32.band(flags, ImGuiTabItemFlags.Button) ~= 0 and g.Style.FrameRounding or g.Style.TabRounding, width * 0.5 - 1.0))
    local y1 = bb.Min.y + 1.0 -- Leave a bit of room in title bars.
    local y2 = bb.Max.y - g.Style.TabBarBorderSize
    draw_list:AddRectFilled(ImVec2(bb.Min.x, y1), ImVec2(bb.Max.x, y2), col, rounding, ImDrawFlags.RoundCornersTop)
    if g.Style.TabBorderSize > 0.0 then
        draw_list:PathLineTo(ImVec2(bb.Min.x, y2))
        draw_list:PathArcToFast(ImVec2(bb.Min.x + rounding, y1 + rounding), rounding, 6, 9)
        draw_list:PathArcToFast(ImVec2(bb.Max.x - rounding, y1 + rounding), rounding, 9, 12)
        draw_list:PathLineTo(ImVec2(bb.Max.x, y2))
        draw_list:PathStroke(ImGui.GetColorU32(ImGuiCol.Border), g.Style.TabBorderSize)
    end
end

-- Render text label (with custom clipping) + Unsaved Document marker + Close Button logic
-- We tend to lock style.FramePadding for a given tab-bar, hence the 'frame_padding' parameter.
--- @return bool just_closed, bool text_clipped
function ImGui.TabItemLabelAndCloseButton(draw_list, bb, flags, frame_padding, label, tab_id, close_button_id, is_contents_visible)
    local g = ImGui.GetCurrentContext()
    local label_end = ImGui.FindRenderedTextEnd(label)
    local label_size = ImGui.CalcTextSize(label, label_end, false)

    if bb:GetWidth() <= 1.0 then return false, false end

    -- Render text label (with clipping + alpha gradient) + unsaved marker
    local text_ellipsis_clip_bb = ImRect(bb.Min.x + frame_padding.x, bb.Min.y + frame_padding.y, bb.Max.x - frame_padding.x, bb.Max.y)

    -- Return clipped state ignoring the close button
    local text_clipped = (text_ellipsis_clip_bb.Min.x + label_size.x) > text_ellipsis_clip_bb.Max.x
    -- draw_list:AddCircle(text_ellipsis_clip_bb.Min, 3.0, text_clipped and IM_COL32(255, 0, 0, 255) or IM_COL32(0, 255, 0, 255))

    local button_sz = g.FontSize
    local button_pos = ImVec2(ImMax(bb.Min.x, bb.Max.x - frame_padding.x - button_sz), bb.Min.y + frame_padding.y)

    -- Close Button & Unsaved Marker
    -- We are relying on a subtle and confusing distinction between 'hovered' and 'g.HoveredId' which happens because we are using ImGuiButtonFlags_AllowOverlapMode + SetItemAllowOverlap()
    --  'hovered' will be true when hovering the Tab but NOT when hovering the close button
    --  'g.HoveredId==id' will be true when hovering the Tab including when hovering the close button
    --  'g.ActiveId==close_button_id' will be true when we are holding on the close button, in which case both hovered booleans are false
    local close_button_pressed = false
    local close_button_visible = false
    local is_hovered = g.HoveredId == tab_id or g.HoveredId == close_button_id or g.ActiveId == tab_id or g.ActiveId == close_button_id -- Any interaction account for this too.

    if close_button_id ~= 0 then
        if is_contents_visible then
            close_button_visible = (g.Style.TabCloseButtonMinWidthSelected < 0.0) or (is_hovered and bb:GetWidth() >= ImMax(button_sz, g.Style.TabCloseButtonMinWidthSelected))
        else
            close_button_visible = (g.Style.TabCloseButtonMinWidthUnselected < 0.0) or (is_hovered and bb:GetWidth() >= ImMax(button_sz, g.Style.TabCloseButtonMinWidthUnselected))
        end
    end

    -- When tabs/document is unsaved, the unsaved marker takes priority over the close button.
    local unsaved_marker_visible = bit32.band(flags, ImGuiTabItemFlags.UnsavedDocument) ~= 0 and (button_pos.x + button_sz <= bb.Max.x) and (not close_button_visible or not is_hovered)
    if unsaved_marker_visible then
        local bullet_pos = button_pos + ImVec2(button_sz, button_sz) * 0.5
        ImGui.RenderBullet(draw_list, bullet_pos, ImGui.GetColorU32(ImGuiCol.UnsavedMarker))
    elseif close_button_visible then
        local last_item_backup = ImGuiLastItemData()
        ImGuiLastItemData_Copy(last_item_backup, g.LastItemData)
        if ImGui.CloseButton(close_button_id, button_pos) then close_button_pressed = true end
        ImGuiLastItemData_Copy(g.LastItemData, last_item_backup)

        -- Close with middle mouse button
        if is_hovered and bit32.band(flags, ImGuiTabItemFlags.NoCloseWithMiddleMouseButton) == 0 and ImGui.IsMouseClicked(2) then
            close_button_pressed = true
        end
    end

    -- This is all rather complicated
    -- (the main idea is that because the close button only appears on hover, we don't want it to alter the ellipsis position)
    -- FIXME: if FramePadding is noticeably large, ellipsis_max_x will be wrong here (e.g. #3497), maybe for consistency that parameter of RenderTextEllipsis() shouldn't exist..
    local ellipsis_max_x = text_ellipsis_clip_bb.Max.x
    if close_button_visible or unsaved_marker_visible then
        local visible_without_hover = unsaved_marker_visible or ((is_contents_visible and g.Style.TabCloseButtonMinWidthSelected or g.Style.TabCloseButtonMinWidthUnselected) < 0.0)
        if visible_without_hover then
            text_ellipsis_clip_bb.Max.x = text_ellipsis_clip_bb.Max.x - button_sz * 0.90
            ellipsis_max_x = ellipsis_max_x - button_sz * 0.90
        else
            text_ellipsis_clip_bb.Max.x = text_ellipsis_clip_bb.Max.x - button_sz * 1.00
        end
    end
    ImGui.LogSetNextTextDecoration("/", "\\")
    ImGui.RenderTextEllipsis(draw_list, text_ellipsis_clip_bb.Min, text_ellipsis_clip_bb.Max, ellipsis_max_x, label, label_end, label_size)

    return close_button_pressed, text_clipped
end
end --[[ [SECTION] Widgets: BeginTabBar, EndTabBar, etc. (was imgui_tabs.lua) ]]

return true -- [Roblox] ModuleScripts must return exactly one value
end

__FILES['imstb_rectpack.lua'] = function()
--- Dear ImGui
-- This is a Lua port of original `imstb_rectpack.h`

-- ALL TABLES IN THIS FILE ARE 1-BASED!
-- Avoids table creation when possible

-- [DEAR IMGUI]
-- This is a slightly modified version of stb_rect_pack.h 1.01.
-- Grep for [DEAR IMGUI] to find the changes.
--
-- stb_rect_pack.h - v1.01 - public domain - rectangle packing
-- Sean Barrett 2014
--
-- Useful for e.g. packing rectangular textures into an atlas.
-- Does not do rotation.
--
-- Not necessarily the awesomest packing method, but better than
-- the totally naive one in stb_truetype (which is primarily what
-- this is meant to replace).
--
-- Has only had a few tests run, may have issues.
--
-- More docs to come.
--
-- Uses table.sort and assert (STBRP_SORT and STBRP_ASSERT below).
--
-- This library currently uses the Skyline Bottom-Left algorithm.
--
-- Please note: better rectangle packers are welcome! Please
-- implement them to the same API, but with a different init
-- function.
--
-- Credits
--
--  Library
--    Sean Barrett
--  Minor features
--    Martins Mozeiko
--    github:IntellectualKitty
--
--  Bugfixes / warning fixes
--    Jeremy Jaussaud
--    Fabian Giesen
--
-- Version history:
--
--     1.01  (2021-07-11)  always use large rect mode, expose STBRP__MAXVAL in public section
--     1.00  (2019-02-25)  avoid small space waste; gracefully fail too-wide rectangles
--     0.99  (2019-02-07)  warning fixes
--     0.11  (2017-03-03)  return packing success/fail result
--     0.10  (2016-10-25)  remove cast-away-const to avoid warnings
--     0.09  (2016-08-27)  fix compiler warnings
--     0.08  (2015-09-13)  really fix bug with empty rects (w=0 or h=0)
--     0.07  (2015-09-13)  fix bug with empty rects (w=0 or h=0)
--     0.06  (2015-04-15)  added STBRP_SORT to allow replacing qsort
--     0.05:  added STBRP_ASSERT to allow replacing assert
--     0.04:  fixed minor bug in STBRP_LARGE_RECTS support
--     0.01:  initial release
--
-- LICENSE
--
--   See end of file for license information.

--- The `prev_link` can be stbrp_context or stbrp_node
--- @diagnostic disable

local bit32 = bit32

local STBRP_SORT = table.sort
local STBRP_ASSERT = assert
local STBRP__NOTUSED = function(_) end

-------------------------------------------------------------------------------
--
--       INCLUDE SECTION
--

local STBRP__MAXVAL = 0x7fffffff
-- Mostly for internal use, but this is the maximum supported coordinate value.

--- @enum STBRP_HEURISTIC_Skyline
local STBRP_HEURISTIC_Skyline = {
    default = 0,
    BL_sortHeight = 0,
    BF_sortHeight = 1
}

local STBRP__INIT_skyline = 1

--- @enum STBRP__PREV_LINK_TYPE
local STBRP__PREV_LINK_TYPE = {
    ACTIVE_HEAD = 0,
    NEXT = 1
}

--- @alias stbrp_coord int

--- @class stbrp_rect
--- @field id         int
--- @field w          stbrp_coord
--- @field h          stbrp_coord
--- @field x          stbrp_coord
--- @field y          stbrp_coord
--- @field was_packed int

--- @return stbrp_rect
--- @nodiscard
local function stbrp_rect()
    return {
        -- reserved for your use:
        id         = 0,

        -- input:
        w          = 0,
        h          = 0,

        -- output:
        x          = 0,
        y          = 0,
        was_packed = 0 -- non-zero if valid packing
    }
end

--- @class stbrp_node
--- @field x    stbrp_coord
--- @field y    stbrp_coord
--- @field next stbrp_node

--- @return stbrp_node
--- @nodiscard
local function stbrp_node()
    return {
        x    = 0,
        y    = 0,
        next = nil
    }
end

--- @class stbrp_context
--- @field width       int
--- @field height      int
--- @field align       int
--- @field init_mode   int
--- @field heuristic   int
--- @field num_nodes   int
--- @field active_head stbrp_node
--- @field free_head   stbrp_node
--- @field extra       stbrp_node[]

--- @return stbrp_context
--- @nodiscard
local function stbrp_context()
    return {
        width     = 0,
        height    = 0,
        align     = 0,
        init_mode = 0,
        heuristic = 0,
        num_nodes = 0,

        active_head = nil,
        free_head   = nil,
        extra       = {stbrp_node(), stbrp_node()} -- we allocate two extra nodes so optimal user-node-count is 'width' not 'width+2'
    }
end

--- @class stbrp__findresult
--- @field x               int
--- @field y               int
--- @field prev_link?      table
--- @field prev_link_type? int

--- @return stbrp__findresult
local function stbrp__findresult()
    return {
        x = 0,
        y = 0,

        prev_link      = nil,
        prev_link_type = nil
    }
end

-------------------------------------------------------------------------------
--
--     IMPLEMENTATION SECTION
--

-- Optionally select which packing heuristic the library should use. Different
-- heuristics will produce better/worse results for different data sets.
-- If you call init again, this will be reset to the default.
--- @param context   stbrp_context
--- @param heuristic int
local function stbrp_setup_heuristic(context, heuristic)
    if context.init_mode == STBRP__INIT_skyline then
        STBRP_ASSERT(heuristic == STBRP_HEURISTIC_Skyline.BL_sortHeight or heuristic == STBRP_HEURISTIC_Skyline.BF_sortHeight)
        context.heuristic = heuristic
    else
        STBRP_ASSERT(false)
    end
end

-- Optionally call this function after init but before doing any packing to
-- change the handling of the out-of-temp-memory scenario, described above.
-- If you call init again, this will be reset to the default (false).
--- @param context          stbrp_context
--- @param allow_out_of_mem boolean
local function stbrp_setup_allow_out_of_mem(context, allow_out_of_mem)
    if allow_out_of_mem then
        -- if it's ok to run out of memory, then don't bother aligning them;
        -- this gives better packing, but may fail due to OOM (even though
        -- the rectangles easily fit). @TODO a smarter approach would be to only
        -- quantize once we've hit OOM, then we could get rid of this parameter.
        context.align = 1
    else
        -- if it's not ok to run out of memory, then quantize the widths
        -- so that num_nodes is always enough nodes.
        --
        -- I.e. num_nodes * align >= width
        --                  align >= width / num_nodes
        --                  align = ceil(width/num_nodes)

        context.align = (context.width + context.num_nodes - 1) / context.num_nodes
    end
end

-- Initialize a rectangle packer to:
--    pack a rectangle that is 'width' by 'height' in dimensions
--    using temporary storage provided by the array 'nodes', which is 'num_nodes' long
--
-- You must call this function every time you start packing into a new target.
--
-- There is no "shutdown" function. The 'nodes' memory must stay valid for
-- the following stbrp_pack_rects() call (or calls), but can be freed after
-- the call (or calls) finish.
--
-- Note: to guarantee best results, either:
--       1. make sure 'num_nodes' >= 'width'
--   or  2. call stbrp_setup_allow_out_of_mem() defined above with 'allow_out_of_mem = true'
--
-- If you don't do either of the above things, widths will be quantized to multiples
-- of small integers to guarantee the algorithm doesn't run out of temporary storage.
--
-- If you do #2, then the non-quantized algorithm will be used, but the algorithm
-- may run out of temporary storage and be unable to pack some rectangles.
--- @param context   stbrp_context
--- @param width     int
--- @param height    int
--- @param nodes     stbrp_node[]
--- @param num_nodes int
function stbrp_init_target(context, width, height, nodes, num_nodes)
    for i = 1, num_nodes - 1 do
        nodes[i].next = nodes[i + 1]
    end
    nodes[num_nodes].next = nil
    context.init_mode = STBRP__INIT_skyline
    context.heuristic = STBRP_HEURISTIC_Skyline.default
    context.free_head = nodes[1]
    context.active_head = context.extra[1]
    context.width = width
    context.height = height
    context.num_nodes = num_nodes
    stbrp_setup_allow_out_of_mem(context, false)

    -- node 0 is the full width, node 1 is the sentinel (lets us not store width explicitly)
    context.extra[1].x = 0
    context.extra[1].y = 0
    context.extra[1].next = context.extra[2]
    context.extra[2].x = width
    context.extra[2].y = bit32.lshift(1, 30)
    context.extra[2].next = nil
end

-- find minimum y position if it starts at x1
-- Returns (min_y, waste_area)
--- @param c stbrp_context
--- @param first stbrp_node
--- @param x0 int
--- @param width int
--- @return int, int
local function stbrp__skyline_find_min_y(c, first, x0, width)
    local node = first
    local x1 = x0 + width

    STBRP__NOTUSED(c)

    STBRP_ASSERT(first.x <= x0)

    STBRP_ASSERT(node.next.x > x0) -- we ended up handling this in the caller for efficiency

    STBRP_ASSERT(node.x <= x0)

    local min_y = 0
    local waste_area = 0
    local visited_width = 0
    while node.x < x1 do
        if node.y > min_y then
            -- raise min_y higher.
            -- we've accounted for all waste up to min_y,
            -- but we'll now add more waste for everything we've visited
            waste_area = waste_area + visited_width * (node.y - min_y)
            min_y = node.y
            -- the first time through, visited_width might be reduced
            if node.x < x0 then
                visited_width = visited_width + node.next.x - x0
            else
                visited_width = visited_width + node.next.x - node.x
            end
        else
            -- add waste area
            local under_width = node.next.x - node.x
            if under_width + visited_width > width then
                under_width = width - visited_width
            end
            waste_area = waste_area + under_width * (min_y - node.y)
            visited_width = visited_width + under_width
        end
        node = node.next
    end

    return min_y, waste_area
end

--- @param c      stbrp_context
--- @param width  int
--- @param height int
--- @return stbrp__findresult
local function stbrp__skyline_find_best_pos(c, width, height)
    local best_waste = bit32.lshift(1, 30)
    local best_x = 0
    local best_y = bit32.lshift(1, 30)
    local fr = stbrp__findresult()
    local best_prev_link = nil
    local best_prev_link_type = nil

    -- align to multiple of c.align
    width = width + c.align - 1
    width = width - width % c.align
    STBRP_ASSERT(width % c.align == 0)

    -- if it can't possibly fit, bail immediately
    if width > c.width or height > c.height then
        fr.prev_link = nil
        fr.prev_link_type = nil
        fr.x = 0
        fr.y = 0
        return fr
    end

    local prev_link = c
    local prev_link_type = STBRP__PREV_LINK_TYPE.ACTIVE_HEAD
    local node = c.active_head

    while (node.x + width <= c.width) do
        local y, waste = stbrp__skyline_find_min_y(c, node, node.x, width)

        if c.heuristic == STBRP_HEURISTIC_Skyline.BL_sortHeight then -- actually just want to test BL
            -- bottom left
            if y < best_y then
                best_y = y
                best_prev_link = prev_link
                best_prev_link_type = prev_link_type
                best_x = node.x
            end
        else
            -- best-fit
            if y + height <= c.height then
                -- can only use it if it first vertically
                if y < best_y or (y == best_y and waste < best_waste) then
                    best_y = y
                    best_waste = waste
                    best_prev_link = prev_link
                    best_prev_link_type = prev_link_type
                    best_x = node.x
                end
            end
        end

        prev_link = node
        prev_link_type = STBRP__PREV_LINK_TYPE.NEXT
        node = node.next
    end

    -- if doing best-fit (BF), we also have to try aligning right edge to each node position
    --
    -- e.g, if fitting
    --
    --     ____________________
    --    |____________________|
    --
    --            into
    --
    --   |                         |
    --   |             ____________|
    --   |____________|
    --
    -- then right-aligned reduces waste, but bottom-left BL is always chooses left-aligned
    --
    -- This makes BF take about 2x the time

    if c.heuristic == STBRP_HEURISTIC_Skyline.BF_sortHeight then
        local tail = c.active_head
        local node_scan = c.active_head
        local prev_link_scan = c
        local prev_link_scan_type = STBRP__PREV_LINK_TYPE.ACTIVE_HEAD

        -- find first node that's admissible
        while tail and tail.x < width do
            tail = tail.next
        end

        while tail do
            local xpos = tail.x - width
            STBRP_ASSERT(xpos >= 0)

            -- find the left position that matches this
            while node_scan.next and node_scan.next.x <= xpos do
                prev_link_scan = node_scan
                prev_link_scan_type = STBRP__PREV_LINK_TYPE.NEXT
                node_scan = node_scan.next
            end

            if node_scan then
                STBRP_ASSERT(node_scan.next.x > xpos and node_scan.x <= xpos)

                local y, waste = stbrp__skyline_find_min_y(c, node_scan, xpos, width)

                if y + height <= c.height then
                    if y <= best_y then
                        if y < best_y or waste < best_waste or (waste == best_waste and xpos < best_x) then
                            best_x = xpos
                            -- STBRP_ASSERT(y <= best_y); [DEAR IMGUI]
                            best_y = y
                            best_waste = waste
                            best_prev_link = prev_link_scan
                            best_prev_link_type = prev_link_scan_type
                        end
                    end
                end
            end

            tail = tail.next
        end
    end

    fr.prev_link = best_prev_link
    fr.prev_link_type = best_prev_link_type
    fr.x = best_x
    fr.y = best_y
    return fr
end

--- @param context stbrp_context
--- @param width   int
--- @param height  int
--- @return stbrp__findresult
local function stbrp__skyline_pack_rectangle(context, width, height)
    -- find best position according to heuristic
    local res = stbrp__skyline_find_best_pos(context, width, height)

    -- bail if:
    --    1. it failed
    --    2. the best node doesn't fit (we don't always check this)
    --    3. we're out of memory
    if res.prev_link == nil or res.y + height > context.height or context.free_head == nil then
        res.prev_link = nil
        res.prev_link_type = nil
        return res
    end

    -- on success, create new node
    local node = context.free_head
    node.x = res.x
    node.y = res.y + height
    context.free_head = node.next

    -- insert the new node into the right starting point, and
    -- let 'cur' point to the remaining nodes needing to be
    -- stitched back in

    local cur
    if res.prev_link_type == STBRP__PREV_LINK_TYPE.ACTIVE_HEAD then
        cur = res.prev_link.active_head
    else
        cur = res.prev_link.next
    end

    if cur.x < res.x then
        -- preserve the existing one, so start testing with the next one
        local next = cur.next
        cur.next = node
        cur = next
    else
        if res.prev_link_type == STBRP__PREV_LINK_TYPE.ACTIVE_HEAD then
            res.prev_link.active_head = node
        else
            res.prev_link.next = node
        end
    end

    -- from here, traverse cur and free the nodes, until we get to one
    -- that shouldn't be freed
    while cur.next and cur.next.x <= res.x + width do
        local next = cur.next
        -- move the current node to the free list
        cur.next = context.free_head
        context.free_head = cur
        cur = next
    end

    -- stitch the list back in
    node.next = cur

    if cur.x < res.x + width then
        cur.x = res.x + width
    end

    return res
end

--- @param a stbrp_rect
--- @param b stbrp_rect
--- @return bool
--- @package
local function rect_height_compare(a, b)
    if a.h > b.h then
        return true
    elseif a.h < b.h then
        return false
    else
        return a.w > b.w
    end
end

--- @param a stbrp_rect
--- @param b stbrp_rect
--- @return bool
--- @package
local function rect_original_order(a, b)
    return a.was_packed < b.was_packed
end

-- Assign packed locations to rectangles. The rectangles are of type
-- 'stbrp_rect' defined above, stored in the array 'rects', and there
-- are 'num_rects' many of them.
--
-- Rectangles which are successfully packed have the 'was_packed' flag
-- set to a non-zero value and 'x' and 'y' store the minimum location
-- on each axis (i.e. bottom-left in cartesian coordinates, top-left
-- if you imagine y increasing downwards). Rectangles which do not fit
-- have the 'was_packed' flag set to 0.
--
-- You should not try to access the 'rects' array from another thread
-- while this function is running, as the function temporarily reorders
-- the array while it executes.
--
-- To pack into another rectangle, you need to call stbrp_init_target
-- again. To continue packing into the same rectangle, you can call
-- this function again. Calling this multiple times with multiple rect
-- arrays will probably produce worse packing results than calling it
-- a single time with the full rectangle array, but the option is
-- available.
--
-- The function returns 1 if all of the rectangles were successfully
-- packed and 0 otherwise.
--- @param context   stbrp_context
--- @param rects     stbrp_rect[]
--- @param num_rects int
--- @return int
local function stbrp_pack_rects(context, rects, num_rects)
    local all_rects_packed = 1

    -- we use the 'was_packed' field internally to allow sorting/unsorting
    for i = 1, num_rects do
        rects[i].was_packed = (i - 1)
    end

    -- sort according to heuristic
    STBRP_SORT(rects, rect_height_compare)

    for i = 1, num_rects do
        if rects[i].w == 0 or rects[i].h == 0 then
            rects[i].x = 0 -- empty rect needs no space
            rects[i].y = 0
        else
            local fr = stbrp__skyline_pack_rectangle(context, rects[i].w, rects[i].h)
            if fr.prev_link then
                rects[i].x = fr.x
                rects[i].y = fr.y
            else
                rects[i].x = STBRP__MAXVAL
                rects[i].y = STBRP__MAXVAL
            end
        end
    end

    -- unsort
    STBRP_SORT(rects, rect_original_order)

    -- set was_packed flags and all_rects_packed status
    for i = 1, num_rects do
        rects[i].was_packed = (rects[i].x == STBRP__MAXVAL and rects[i].y == STBRP__MAXVAL) and 0 or 1
        if rects[i].was_packed == 0 then
            all_rects_packed = 0
        end
    end

    -- return the all_rects_packed status
    return all_rects_packed
end

return {
    context = stbrp_context,
    rect    = stbrp_rect,
    node    = stbrp_node,

    pack_rects             = stbrp_pack_rects,
    init_target            = stbrp_init_target,
    setup_allow_out_of_mem = stbrp_setup_allow_out_of_mem,
    setup_heuristic        = stbrp_setup_heuristic
}

-- ------------------------------------------------------------------------------
-- This software is available under 2 licenses -- choose whichever you prefer.
-- ------------------------------------------------------------------------------
-- ALTERNATIVE A - MIT License
-- Copyright (c) 2017 Sean Barrett
-- Permission is hereby granted, free of charge, to any person obtaining a copy of
-- this software and associated documentation files (the "Software"), to deal in
-- the Software without restriction, including without limitation the rights to
-- use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
-- of the Software, and to permit persons to whom the Software is furnished to do
-- so, subject to the following conditions:
-- The above copyright notice and this permission notice shall be included in all
-- copies or substantial portions of the Software.
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-- SOFTWARE.
-- ------------------------------------------------------------------------------
-- ALTERNATIVE B - Public Domain (www.unlicense.org)
-- This is free and unencumbered software released into the public domain.
-- Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
-- software, either in source code form or as a compiled binary, for any purpose,
-- commercial or non-commercial, and by any means.
-- In jurisdictions that recognize copyright laws, the author or authors of this
-- software dedicate any and all copyright interest in the software to the public
-- domain. We make this dedication for the benefit of the public at large and to
-- the detriment of our heirs and successors. We intend this dedication to be an
-- overt act of relinquishment in perpetuity of all present and future rights to
-- this software under copyright law.
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
-- ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
-- WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-- ------------------------------------------------------------------------------
end

__FILES['imstb_textedit.lua'] = function()
--- Dear ImGui
-- This is a Lua port of original `imstb_textedit.h`

-- [DEAR IMGUI]
-- This is a slightly modified version of stb_textedit.h 1.14.
-- Those changes would need to be pushed into nothings/stb:
-- - Fix in stb_textedit_discard_redo (see https://github.com/nothings/stb/issues/321)
-- - Fix in stb_textedit_find_charpos to handle last line (see https://github.com/ocornut/imgui/issues/6000 + #6783)
-- - Added name to struct or it may be forward declared in our code.
-- - Added UTF-8 support (see https://github.com/nothings/stb/issues/188 + https://github.com/ocornut/imgui/pull/7925)
-- - Changed STB_TEXTEDIT_INSERTCHARS() to return inserted count (instead of 0/1 bool), allowing partial insertion.
-- Grep for [DEAR IMGUI] to find some changes.
-- - Also renamed macros used or defined outside of IMSTB_TEXTEDIT_IMPLEMENTATION block from STB_TEXTEDIT_* to IMSTB_TEXTEDIT_*

-- stb_textedit.h - v1.14  - public domain - Sean Barrett
-- Development of this library was sponsored by RAD Game Tools
--
-- This C header file implements the guts of a multi-line text-editing
-- widget; you implement display, word-wrapping, and low-level string
-- insertion/deletion, and stb_textedit will map user inputs into
-- insertions & deletions, plus updates to the cursor position,
-- selection state, and undo state.
--
-- It is intended for use in games and other systems that need to build
-- their own custom widgets and which do not have heavy text-editing
-- requirements (this library is not recommended for use for editing large
-- texts, as its performance does not scale and it has limited undo).
--
-- Non-trivial behaviors are modelled after Windows text controls.
--
--
-- LICENSE
--
-- See end of file for license information.
--
--
-- DEPENDENCIES
--
-- Uses the C runtime function 'memmove', which you can override
-- by defining IMSTB_TEXTEDIT_memmove before the implementation.
-- (In this port: ImStb.TEXTEDIT_memmove.)
--
--
-- VERSION HISTORY
--
--   !!!! (2025-10-23) changed STB_TEXTEDIT_INSERTCHARS() to return inserted count (instead of 0/1 bool), allowing partial insertion.
--   1.14 (2021-07-11) page up/down, various fixes
--   1.13 (2019-02-07) fix bug in undo size management
--   1.12 (2018-01-29) user can change STB_TEXTEDIT_KEYTYPE, fix redo to avoid crash
--   1.11 (2017-03-03) fix HOME on last line, dragging off single-line textfield
--   1.10 (2016-10-25) suppress warnings about casting away const with -Wcast-qual
--   1.9  (2016-08-27) customizable move-by-word
--   1.8  (2016-04-02) better keyboard handling when mouse button is down
--   1.7  (2015-09-13) change y range handling in case baseline is non-0
--   1.6  (2015-04-15) allow STB_TEXTEDIT_memmove
--   1.5  (2014-09-10) add support for secondary keys for OS X
--   1.4  (2014-08-17) fix signed/unsigned warnings
--   1.3  (2014-06-19) fix mouse clicking to round to nearest char boundary
--   1.2  (2014-05-27) fix some RAD types that had crept into the new code
--   1.1  (2013-12-15) move-by-word (requires STB_TEXTEDIT_IS_SPACE )
--   1.0  (2012-07-26) improve documentation, initial public release
--   0.3  (2012-02-24) bugfixes, single-line mode; insert mode
--   0.2  (2011-11-28) fixes to undo/redo
--   0.1  (2010-07-08) initial version
--
-- ADDITIONAL CONTRIBUTORS
--
--   Ulf Winklemann: move-by-word in 1.1
--   Fabian Giesen: secondary key inputs in 1.5
--   Martins Mozeiko: STB_TEXTEDIT_memmove in 1.6
--   Louis Schnellbach: page up/down in 1.14
--
--   Bugfixes:
--      Scott Graham
--      Daniel Keller
--      Omar Cornut
--      Dan Thompson
--
-- USAGE
--
--   The basic concept is that you provide a "string" object which
--   behaves like an array of characters. stb_textedit uses indices to
--   refer to positions in the string, implicitly representing positions
--   in the displayed textedit. This is true for both plain text and
--   rich text; even with rich text stb_truetype interacts with your
--   code as if there was an array of all the displayed characters.
--
-- Symbols you must define for implementation mode (in this port: fields of ImStb, see below):
--
--    STB_TEXTEDIT_STRING               the type of object representing a string being edited,
--                                      typically this is a wrapper object with other data you need
--
--    STB_TEXTEDIT_STRINGLEN(obj)       the length of the string (ideally O(1))
--    STB_TEXTEDIT_LAYOUTROW(r,obj,n)   returns the results of laying out a line of characters
--                                        starting from character #n (see discussion below)
--    STB_TEXTEDIT_GETWIDTH(obj,n,i)    returns the pixel delta from the xpos of the i'th character
--                                        to the xpos of the i+1'th char for a line of characters
--                                        starting at character #n (i.e. accounts for kerning
--                                        with previous char)
--    STB_TEXTEDIT_GETCHAR(obj,i)       returns the i'th character of obj, 1-based in this port
--    STB_TEXTEDIT_NEWLINE              the character returned by _GETCHAR() we recognize
--                                        as manually wordwrapping for end-of-line positioning
--
--    STB_TEXTEDIT_DELETECHARS(obj,i,n)      delete n characters starting at i
--    STB_TEXTEDIT_INSERTCHARS(obj,i,c,c_offset,n)   try to insert n characters at i (taken from array c starting at c_offset)
--                                           returns number of characters actually inserted. [DEAR IMGUI]
--
--    STB_TEXTEDIT_K_SHIFT       a power of two that is or'd in to a keyboard input to represent the shift key
--
--    STB_TEXTEDIT_K_LEFT        keyboard input to move cursor left
--    STB_TEXTEDIT_K_RIGHT       keyboard input to move cursor right
--    STB_TEXTEDIT_K_UP          keyboard input to move cursor up
--    STB_TEXTEDIT_K_DOWN        keyboard input to move cursor down
--    STB_TEXTEDIT_K_PGUP        keyboard input to move cursor up a page
--    STB_TEXTEDIT_K_PGDOWN      keyboard input to move cursor down a page
--    STB_TEXTEDIT_K_LINESTART   keyboard input to move cursor to start of line  -- e.g. HOME
--    STB_TEXTEDIT_K_LINEEND     keyboard input to move cursor to end of line    -- e.g. END
--    STB_TEXTEDIT_K_TEXTSTART   keyboard input to move cursor to start of text  -- e.g. ctrl-HOME
--    STB_TEXTEDIT_K_TEXTEND     keyboard input to move cursor to end of text    -- e.g. ctrl-END
--    STB_TEXTEDIT_K_DELETE      keyboard input to delete selection or character under cursor
--    STB_TEXTEDIT_K_BACKSPACE   keyboard input to delete selection or character left of cursor
--    STB_TEXTEDIT_K_UNDO        keyboard input to perform undo
--    STB_TEXTEDIT_K_REDO        keyboard input to perform redo
--
--    STB_TEXTEDIT_MOVEWORDLEFT(obj,i)   custom handler for WORDLEFT, returns index to move cursor to
--    STB_TEXTEDIT_MOVEWORDRIGHT(obj,i)  custom handler for WORDRIGHT, returns index to move cursor to
--    STB_TEXTEDIT_K_WORDLEFT            keyboard input to move cursor left one word -- e.g. ctrl-LEFT
--    STB_TEXTEDIT_K_WORDRIGHT           keyboard input to move cursor right one word -- e.g. ctrl-RIGHT
--
-- To support UTF-8:
--
--    STB_TEXTEDIT_GETPREVCHARINDEX      returns index of previous character
--    STB_TEXTEDIT_GETNEXTCHARINDEX      returns index of next character
--    Do NOT define STB_TEXTEDIT_KEYTOTEXT.
--    Instead, call stb_textedit_text() directly for text contents.
--
-- Keyboard input must be encoded as a single integer value; e.g. a character code
-- and some bitflags that represent shift states. to simplify the interface, SHIFT must
-- be a bitflag, so we can test the shifted state of cursor movements to allow selection,
-- i.e. (STB_TEXTEDIT_K_RIGHT|STB_TEXTEDIT_K_SHIFT) should be shifted right-arrow.
--
-- STB_TEXTEDIT_LAYOUTROW returns information about the shape of one displayed
-- row of characters assuming they start on the i'th character--the width and
-- the height and the number of characters consumed. This allows this library
-- to traverse the entire layout incrementally. You need to compute word-wrapping
-- here.
--
-- Each textfield keeps its own insert mode state, which is not how normal
-- applications work. To keep an app-wide insert mode, update/copy the
-- "insert_mode" field of STB_TexteditState before/after calling API functions.
--
-- API (in this port: fields of the table returned by this file)
--
--    initialize_state(state, is_single_line)
--
--    click(str, state, x, y)
--    drag(str, state, x, y)
--    cut(str, state) -> bool
--    paste(str, state, text, len) -> bool
--    key(str, state, key)
--    text(str, state, text, text_len)
--
--    Each of these functions potentially updates the string and updates the
--    state.
--
--      initialize_state:
--          set the textedit state to a known good default state when initially
--          constructing the textedit.
--
--      click:
--          call this with the mouse x,y on a mouse down; it will update the cursor
--          and reset the selection start/end to the cursor point. the x,y must
--          be relative to the text widget, with (0,0) being the top left.
--
--      drag:
--          call this with the mouse x,y on a mouse drag/up; it will update the
--          cursor and the selection end point
--
--      cut:
--          call this to delete the current selection; returns true if there was
--          one. you should FIRST copy the current selection to the system paste buffer.
--          (To copy, just copy the current selection out of the string yourself.)
--
--      paste:
--          call this to paste text at the current cursor point or over the current
--          selection if there is one.
--
--      key:
--          call this for keyboard inputs sent to the textfield. you can use it
--          for "key down" events or for "translated" key events.
--
--      text: (added 2025)
--          call this to directly send text input the textfield, which is required
--          for UTF-8 support, because stb_textedit_key() + STB_TEXTEDIT_KEYTOTEXT()
--          cannot infer text length.
--
--
--   When rendering, you can read the cursor position and selection state from
--   the STB_TexteditState.
--
--
-- Notes:
--
-- This is designed to be usable in IMGUI, so it allows for the possibility of
-- running in an IMGUI that has NOT cached the multi-line layout. For this
-- reason, it provides an interface that is compatible with computing the
-- layout incrementally--we try to make sure we make as few passes through
-- as possible. (For example, to locate the mouse pointer in the text, we
-- could define functions that return the X and Y positions of characters
-- and binary search Y and then X, but if we're doing dynamic layout this
-- will run the layout algorithm many times, so instead we manually search
-- forward in one pass. Similar logic applies to e.g. up-arrow and
-- down-arrow movement.)
--
-- If it's run in a widget that *has* cached the layout, then this is less
-- efficient, but it's not horrible on modern computers. But you wouldn't
-- want to edit million-line files with it.

-- ALL TABLES IN THIS FILE ARE 1-BASED!
-- Character Indexing:
--     idx=n, the n'th char (1-based)
-- Cursor Indexing:
--     idx=n, the position before the n'th char
--     idx=n+1, the position after the n'th char

-- Symbols that must be defined before using this:
local STB_TEXTEDIT_STRINGLEN = ImStb.TEXTEDIT_STRINGLEN
local STB_TEXTEDIT_GETCHAR   = ImStb.TEXTEDIT_GETCHAR
local STB_TEXTEDIT_GETWIDTH  = ImStb.TEXTEDIT_GETWIDTH
local STB_TEXTEDIT_LAYOUTROW = ImStb.TEXTEDIT_LAYOUTROW
-- [DEAR IMGUI]
-- Functions must be implemented for UTF8 support
-- Code in this file that uses those functions is modified for [DEAR IMGUI] and deviates from the original stb_textedit.
-- There is not necessarily a '[DEAR IMGUI]' at the usage sites.
local IMSTB_TEXTEDIT_GETNEXTCHARINDEX = ImStb.TEXTEDIT_GETNEXTCHARINDEX
local IMSTB_TEXTEDIT_GETPREVCHARINDEX = ImStb.TEXTEDIT_GETPREVCHARINDEX
local STB_TEXTEDIT_MOVEWORDLEFT  = ImStb.TEXTEDIT_MOVEWORDLEFT
local STB_TEXTEDIT_MOVEWORDRIGHT = ImStb.TEXTEDIT_MOVEWORDRIGHT
local STB_TEXTEDIT_MOVELINESTART = ImStb.TEXTEDIT_MOVELINESTART
local STB_TEXTEDIT_MOVELINEEND   = ImStb.TEXTEDIT_MOVELINEEND
local STB_TEXTEDIT_DELETECHARS   = ImStb.TEXTEDIT_DELETECHARS
local STB_TEXTEDIT_INSERTCHARS   = ImStb.TEXTEDIT_INSERTCHARS

STB_TEXTEDIT_NEWLINE     = 10 -- the character returned by _GETCHAR() we recognize as manually wordwrapping for end-of-line positioning
STB_TEXTEDIT_K_LEFT      = 0x200000 -- keyboard input to move cursor left
STB_TEXTEDIT_K_RIGHT     = 0x200001 -- keyboard input to move cursor right
STB_TEXTEDIT_K_UP        = 0x200002 -- keyboard input to move cursor up
STB_TEXTEDIT_K_DOWN      = 0x200003 -- keyboard input to move cursor down
STB_TEXTEDIT_K_LINESTART = 0x200004 -- keyboard input to move cursor to start of line  -- e.g. HOME
STB_TEXTEDIT_K_LINEEND   = 0x200005 -- keyboard input to move cursor to end of line    -- e.g. END
STB_TEXTEDIT_K_TEXTSTART = 0x200006 -- keyboard input to move cursor to start of text  -- e.g. ctrl-HOME
STB_TEXTEDIT_K_TEXTEND   = 0x200007 -- keyboard input to move cursor to end of text    -- e.g. ctrl-END
STB_TEXTEDIT_K_DELETE    = 0x200008 -- keyboard input to delete selection or character under cursor
STB_TEXTEDIT_K_BACKSPACE = 0x200009 -- keyboard input to delete selection or character left of cursor
STB_TEXTEDIT_K_UNDO      = 0x20000A -- keyboard input to perform undo
STB_TEXTEDIT_K_REDO      = 0x20000B -- keyboard input to perform redo
STB_TEXTEDIT_K_WORDLEFT  = 0x20000C -- keyboard input to move cursor left one word -- e.g. ctrl-LEFT
STB_TEXTEDIT_K_WORDRIGHT = 0x20000D -- keyboard input to move cursor right one word -- e.g. ctrl-RIGHT
STB_TEXTEDIT_K_PGUP      = 0x20000E -- keyboard input to move cursor up a page
STB_TEXTEDIT_K_PGDOWN    = 0x20000F -- keyboard input to move cursor down a page
STB_TEXTEDIT_K_SHIFT     = 0x400000 -- a power of two that is or'd in to a keyboard input to represent the shift key

IMSTB_TEXTEDIT_UNDOSTATECOUNT = 99 -- the number of undo states to allow
local IMSTB_TEXTEDIT_UNDOCHARCOUNT  = 999 -- the number of characters to store in the undo buffer
local IMSTB_TEXTEDIT_memmove = ImStb.TEXTEDIT_memmove

-- forward declarations
local stb_text_undo
local stb_text_redo

-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
---
--- STB_TexteditState
---
--- Definition of STB_TexteditState which you should store
--- per-textfield; it includes cursor position, selection state,
--- and undo state.
---
--- @alias IMSTB_TEXTEDIT_POSITIONTYPE int
--- @alias IMSTB_TEXTEDIT_CHARTYPE     char

--- @alias STB_TEXTEDIT_KEYTYPE int

--- @class StbUndoRecord
--- @field where         IMSTB_TEXTEDIT_POSITIONTYPE
--- @field insert_length IMSTB_TEXTEDIT_POSITIONTYPE
--- @field delete_length IMSTB_TEXTEDIT_POSITIONTYPE
--- @field char_storage  int

--- @return StbUndoRecord
--- @nodiscard
local function StbUndoRecord()
    return {
        -- private data
        where         = 1,
        insert_length = 0,
        delete_length = 0,
        char_storage  = 1
    }
end

--- @class StbUndoState
--- @field undo_rec        StbUndoRecord[]           # size = IMSTB_TEXTEDIT_UNDOSTATECOUNT
--- @field undo_char       IMSTB_TEXTEDIT_CHARTYPE[] # size = IMSTB_TEXTEDIT_UNDOCHARCOUNT
--- @field undo_point      short                     # next available slot
--- @field redo_point      short                     # next available slot
--- @field undo_char_point int                       # next available slot
--- @field redo_char_point int                       # next available slot

--- @return StbUndoState
--- @nodiscard
local function StbUndoState()
    local undo_rec = {}
    for i = 1, IMSTB_TEXTEDIT_UNDOSTATECOUNT do
        undo_rec[i] = StbUndoRecord()
    end

    local undo_char = {}
    for i = 1, IMSTB_TEXTEDIT_UNDOCHARCOUNT do
        undo_char[i] = 0
    end

    return {
        -- private data
        undo_rec        = undo_rec,
        undo_char       = undo_char,

        undo_point      = 1,
        redo_point      = 1,
        undo_char_point = 1,
        redo_char_point = 1
    }
end

--- @class STB_TexteditState
--- @field cursor                int           # position of the text cursor within the string
--- @field select_start          int           # selection start point
--- @field select_end            int
--- @field insert_mode           bool
--- @field row_count_per_page    int
--- @field cursor_at_end_of_line bool          # not implemented yet
--- @field initialized           bool
--- @field has_preferred_x       bool
--- @field single_line           bool
--- @field padding1              unsigned_char
--- @field padding2              unsigned_char
--- @field padding3              unsigned_char
--- @field preferred_x           float
--- @field undostate             StbUndoState

--- @return STB_TexteditState
--- @nodiscard
function STB_TexteditState()
    return {
        ---------------------
        --
        -- public data
        --

        cursor = 0,
        -- position of the text cursor within the string

        select_start = 0, -- selection start point
        select_end   = 0,
        -- selection start and end point in characters; if equal, no selection.
        -- note that start may be less than or greater than end (e.g. when
        -- dragging the mouse, start is where the initial click was, and you
        -- can drag in either direction)

        insert_mode = false,
        -- each textfield keeps its own insert mode state. to keep an app-wide
        -- insert mode, copy this value in/out of the app state

        row_count_per_page = 0,
        -- page size in number of row.
        -- this value MUST be set to >0 for pageup or pagedown in multilines documents.

        ---------------------
        --
        -- private data
        --
        cursor_at_end_of_line = false, -- not implemented yet
        initialized           = false,
        has_preferred_x       = false,
        single_line           = false,
        padding1 = 0,
        padding2 = 0,
        padding3 = 0,

        preferred_x = 0.0, -- this determines where the cursor up/down tries to seek to along x

        undostate = StbUndoState()
    }
end

--- @param s STB_TexteditState
local function STB_TEXT_HAS_SELECTION(s)
    return s.select_start ~= s.select_end
end

-------------------------------------------------------------------------------
---
--- StbTexteditRow
---
--- Result of layout query, used by stb_textedit to determine where
--- the text in each row is.

-- result of layout query
--- @class StbTexteditRow
--- @field x0               float # starting x location, end x location (allows for align=right, etc)
--- @field x1               float # end x location
--- @field baseline_y_delta float # position of baseline relative to previous row's baseline
--- @field ymin             float # height of row above and below baseline
--- @field ymax             float # height of row above and below baseline
--- @field num_chars        int

--- @return StbTexteditRow
--- @nodiscard
local function StbTexteditRow()
    return {
        x0 = 0.0,
        x1 = 0.0,

        baseline_y_delta = 0.0,

        ymin = 0.0,
        ymax = 0.0,

        num_chars = 0
    }
end

--- @param r StbTexteditRow
local function StbTexteditRow_Reset(r)
    r.x0 = 0.0
    r.x1 = 0.0
    r.baseline_y_delta = 0.0
    r.ymin = 0.0
    r.ymax = 0.0
    r.num_chars = 0
end

----------------------------------------
----------------------------------------
---
--- Implementation mode
---
---

-------------------------------------------------------------------------------
---
---      Mouse input handling
---

local stb_text_locate_coord do

-- only create once, reuse later
local r = StbTexteditRow()

--- traverse the layout to locate the nearest character to a display position
--- @param str IMSTB_TEXTEDIT_STRING
--- @param x   float
--- @param y   float
--- @return int  idx
--- @return bool side_on_line
function stb_text_locate_coord(str, x, y)
    local n = STB_TEXTEDIT_STRINGLEN(str)
    local base_y = 0
    local prev_x

    StbTexteditRow_Reset(r)

    local out_side_on_line = false

    -- search rows to find one that straddles 'y'
    local i = 1
    while i <= n do
        STB_TEXTEDIT_LAYOUTROW(r, str, i)
        if r.num_chars <= 0 then
            return n + 1, out_side_on_line
        end

        if i == 1 and y < base_y + r.ymin then
            return 1, out_side_on_line
        end

        if y < base_y + r.ymax then
            break
        end

        i = i + r.num_chars
        base_y = base_y + r.baseline_y_delta
    end

    -- below all text, return 'after' last character
    if i > n then
        out_side_on_line = true
        return n + 1, out_side_on_line
    end

    -- check if it's before the beginning of the line
    if x < r.x0 then
        return i, out_side_on_line
    end

    -- check if it's before the end of the line
    if x < r.x1 then
        -- search characters in row for one that straddles 'x'
        prev_x = r.x0
        local k = 1
        while k <= r.num_chars do
            local w = STB_TEXTEDIT_GETWIDTH(str, i, k)
            if x < prev_x + w then
                out_side_on_line = (k == 1) and false or true
                if x < prev_x + w / 2 then
                    return k + i - 1, out_side_on_line
                else
                    return IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, i + k - 1), out_side_on_line
                end
            end
            prev_x = prev_x + w
            k = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, i + k - 1) - i + 1
        end
        -- shouldn't happen, but if it does, fall through to end-of-line case
    end

    -- if the last character is a newline, return that. otherwise return 'after' the last character
    out_side_on_line = true
    if STB_TEXTEDIT_GETCHAR(str, i + r.num_chars - 1) == STB_TEXTEDIT_NEWLINE then
        return i + r.num_chars - 1, out_side_on_line
    else
        return i + r.num_chars, out_side_on_line
    end
end

end

local stb_textedit_click do

local r = StbTexteditRow()

-- API click: on mouse down, move the cursor to the clicked location, and reset the selection
--- @param str   IMSTB_TEXTEDIT_STRING
--- @param state STB_TexteditState
--- @param x     float
--- @param y     float
function stb_textedit_click(str, state, x, y)
    -- In single-line mode, just always make y = 0. This lets the drag keep working if the mouse
    -- goes off the top or bottom of the text
    local side_on_line
    if state.single_line then
        StbTexteditRow_Reset(r)
        STB_TEXTEDIT_LAYOUTROW(r, str, 1)
        y = r.ymin
    end

    state.cursor, side_on_line = stb_text_locate_coord(str, x, y)
    state.select_start = state.cursor
    state.select_end = state.cursor
    state.has_preferred_x = false
    str.LastMoveDirectionLR = side_on_line and ImGuiDir.Right or ImGuiDir.Left
end

end

local stb_textedit_drag do

local r = StbTexteditRow()

-- API drag: on mouse drag, move the cursor and selection endpoint to the clicked location
--- @param str   IMSTB_TEXTEDIT_STRING
--- @param state STB_TexteditState
--- @param x     float
--- @param y     float
function stb_textedit_drag(str, state, x, y)
    local p = 1
    local side_on_line

    -- In single-line mode, just always make y = 0. This lets the drag keep working if the mouse
    -- goes off the top or bottom of the text
    if state.single_line then
        StbTexteditRow_Reset(r)
        STB_TEXTEDIT_LAYOUTROW(r, str, 1)
        y = r.ymin
    end

    if state.select_start == state.select_end then
        state.select_start = state.cursor
    end

    p, side_on_line = stb_text_locate_coord(str, x, y)
    state.cursor = p
    state.select_end = p
    str.LastMoveDirectionLR = (side_on_line ~= false) and ImGuiDir.Right or ImGuiDir.Left
end

end

---------------------------
---------------------------
---
--- Keyboard input handling
---
---

-- forward declarations
local stb_text_makeundo_insert
local stb_text_makeundo_delete
local stb_text_makeundo_replace

--- @class StbFindState
--- @field x          float # position of n'th character
--- @field y          float
--- @field height     float # height of line
--- @field first_char int   # first char of row, and length
--- @field length     int
--- @field prev_first int   # first char of previous row

--- @return StbFindState
local function StbFindState()
    return {
        x = 0.0, y = 0.0,
        height = 0.0,
        first_char = 0, length = 0,
        prev_first = 0
    }
end

--- @param f StbFindState
local function StbFindState_Reset(f)
    f.x = 0.0
    f.y = 0.0
    f.height = 0.0
    f.first_char = 0
    f.length = 0
    f.prev_first = 0
end

local stb_textedit_find_charpos do

local r = StbTexteditRow()

-- find the x/y location of a character, and remember info about the previous row in
-- case we get a move-up event (for page up, we'll have to rescan)
--- @param find        StbFindState
--- @param str         IMSTB_TEXTEDIT_STRING
--- @param n           int
--- @param single_line bool
function stb_textedit_find_charpos(find, str, n, single_line)
    StbTexteditRow_Reset(r)
    local prev_start = 1
    local z = STB_TEXTEDIT_STRINGLEN(str)
    local first

    if n == z + 1 and single_line then
        -- special case if it's at the end (may not be needed?)
        STB_TEXTEDIT_LAYOUTROW(r, str, 1)
        find.y = 0
        find.first_char = 1
        find.length = z
        find.height = r.ymax - r.ymin
        find.x = r.x1

        return
    end

    -- search rows to find the one that straddles character n
    find.y = 0

    local i = 1
    while true do
        STB_TEXTEDIT_LAYOUTROW(r, str, i)
        if n < i + r.num_chars - 1 then
            break
        end
        if str.LastMoveDirectionLR == ImGuiDir.Right and str.Stb.cursor > 1 and str.Stb.cursor == i + r.num_chars and STB_TEXTEDIT_GETCHAR(str, i + r.num_chars - 1) ~= STB_TEXTEDIT_NEWLINE then -- [DEAR IMGUI] Wrapping point handling
            break
        end
        if (i - 1) + r.num_chars == z and z > 0 and STB_TEXTEDIT_GETCHAR(str, z) ~= STB_TEXTEDIT_NEWLINE then -- [DEAR IMGUI] special handling for last line
            break -- [DEAR IMGUI]
        end
        prev_start = i
        i = i + r.num_chars
        find.y = find.y + r.baseline_y_delta
        if i == z + 1 then -- [DEAR IMGUI]
            r.num_chars = 0 -- [DEAR IMGUI]
            break -- [DEAR IMGUI]
        end
    end

    find.first_char = i
    first = i
    find.length = r.num_chars
    find.height = r.ymax - r.ymin
    find.prev_first = prev_start

    -- now scan to find xpos
    find.x = r.x0
    i = 1
    while first + i <= n + 1 do
        find.x = find.x + STB_TEXTEDIT_GETWIDTH(str, first, i)
        i = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, first + i - 1) - first + 1
    end
end

end

-- make the selection/cursor state valid if client altered the string
--- @param str   IMSTB_TEXTEDIT_STRING
--- @param state STB_TexteditState
local function stb_textedit_clamp(str, state)
    local n = STB_TEXTEDIT_STRINGLEN(str)
    if STB_TEXT_HAS_SELECTION(state) then
        if state.select_start > n + 1 then state.select_start = n + 1 end
        if state.select_end > n + 1 then state.select_end = n + 1 end
        -- if clamping forced them to be equal, move the cursor to match
        if state.select_start == state.select_end then
            state.cursor = state.select_start
        end
    end
    if state.cursor > n + 1 then state.cursor = n + 1 end
end

-- delete characters while updating undo
--- @param str   IMSTB_TEXTEDIT_STRING
--- @param state STB_TexteditState
--- @param where int
--- @param len   int
local function stb_textedit_delete(str, state, where, len)
    stb_text_makeundo_delete(str, state, where, len)
    STB_TEXTEDIT_DELETECHARS(str, where, len)
    state.has_preferred_x = false
end

-- delete the section
--- @param str   IMSTB_TEXTEDIT_STRING
--- @param state STB_TexteditState
local function stb_textedit_delete_selection(str, state)
    stb_textedit_clamp(str, state)
    if STB_TEXT_HAS_SELECTION(state) then
        if state.select_start < state.select_end then
            stb_textedit_delete(str, state, state.select_start, state.select_end - state.select_start)
            state.cursor = state.select_start
            state.select_end = state.cursor
        else
            stb_textedit_delete(str, state, state.select_end, state.select_start - state.select_end)
            state.cursor = state.select_end
            state.select_start = state.cursor
        end
        state.has_preferred_x = false
    end
end

-- canoncialize the selection so start <= end
--- @param state STB_TexteditState
local function stb_textedit_sortselection(state)
    if state.select_end < state.select_start then
        local temp = state.select_end
        state.select_end = state.select_start
        state.select_start = temp
    end
end

-- move cursor to first character of selection
--- @param state STB_TexteditState
local function stb_textedit_move_to_first(state)
    if STB_TEXT_HAS_SELECTION(state) then
        stb_textedit_sortselection(state)
        state.cursor = state.select_start
        state.select_end = state.select_start
        state.has_preferred_x = false
    end
end

-- move cursor to last character of selection
--- @param str   IMSTB_TEXTEDIT_STRING
--- @param state STB_TexteditState
local function stb_textedit_move_to_last(str, state)
    if STB_TEXT_HAS_SELECTION(state) then
        stb_textedit_sortselection(state)
        stb_textedit_clamp(str, state)
        state.cursor = state.select_end
        state.select_start = state.select_end
        state.has_preferred_x = false
    end
end

-- update selection and cursor to match each other
--- @param state STB_TexteditState
local function stb_textedit_prep_selection_at_cursor(state)
    if not STB_TEXT_HAS_SELECTION(state) then
        state.select_start = state.cursor
        state.select_end = state.cursor
    else
        state.cursor = state.select_end
    end
end

-- API cut: delete selection
--- @param str   IMSTB_TEXTEDIT_STRING
--- @param state STB_TexteditState
--- @return bool
local function stb_textedit_cut(str, state)
    if STB_TEXT_HAS_SELECTION(state) then
        stb_textedit_delete_selection(str, state) -- implicitly clamps
        state.has_preferred_x = false
        return true
    end
    return false
end

-- API paste: replace existing selection with passed-in text
--- @param str   IMSTB_TEXTEDIT_STRING
--- @param state STB_TexteditState
--- @param text  IMSTB_TEXTEDIT_CHARTYPE[]
--- @param len   int
--- @return bool
local function stb_textedit_paste_internal(str, state, text, len)
    -- if there's a selection, the paste should delete it
    stb_textedit_clamp(str, state)
    stb_textedit_delete_selection(str, state)
    -- try to insert the characters
    len = STB_TEXTEDIT_INSERTCHARS(str, state.cursor, text, 1, len)
    if len then
        stb_text_makeundo_insert(state, state.cursor, len)
        state.cursor = state.cursor + len
        state.has_preferred_x = false
        return true
    end
    -- note: paste failure will leave deleted selection, may be restored with an undo (see https://github.com/nothings/stb/issues/734 for details)
    return false
end

-- API key: process text input
-- [DEAR IMGUI] Added stb_textedit_text(), extracted out and called by stb_textedit_key() for backward compatibility.
--- @param str       IMSTB_TEXTEDIT_STRING
--- @param state     STB_TexteditState
--- @param text      IMSTB_TEXTEDIT_CHARTYPE[]
--- @param text_len int
local function stb_textedit_text(str, state, text, text_len)
    -- can't add newline in single-line mode
    if text[1] == STB_TEXTEDIT_NEWLINE and state.single_line then
        return
    end

    if state.insert_mode and not STB_TEXT_HAS_SELECTION(state) and state.cursor < STB_TEXTEDIT_STRINGLEN(str) then
        stb_text_makeundo_replace(str, state, state.cursor, 1, 1)
        STB_TEXTEDIT_DELETECHARS(str, state.cursor, 1)
        text_len = STB_TEXTEDIT_INSERTCHARS(str, state.cursor, text, 1, text_len)
        if text_len then
            state.cursor = state.cursor + text_len
            state.has_preferred_x = false
        end
    else
        stb_textedit_delete_selection(str, state) -- implicitly clamps
        text_len = STB_TEXTEDIT_INSERTCHARS(str, state.cursor, text, 1, text_len)
        if text_len then
            stb_text_makeundo_insert(state, state.cursor, text_len)
            state.cursor = state.cursor + text_len
            state.has_preferred_x = false
        end
    end
end

local stb_textedit_key do

local find = StbFindState()
local row = StbTexteditRow()

-- API key: process a keyboard input
--- @param str   IMSTB_TEXTEDIT_STRING
--- @param state STB_TexteditState
--- @param key   STB_TEXTEDIT_KEYTYPE
function stb_textedit_key(str, state, key)
    if key == STB_TEXTEDIT_K_UNDO then
        stb_text_undo(str, state)
        state.has_preferred_x = false
    elseif key == STB_TEXTEDIT_K_REDO then
        stb_text_redo(str, state)
        state.has_preferred_x = false
    elseif key == STB_TEXTEDIT_K_LEFT then
        -- if currently there's a selection, move cursor to start of selection
        if STB_TEXT_HAS_SELECTION(state) then
            stb_textedit_move_to_first(state)
        else
            if state.cursor > 1 then
                state.cursor = IMSTB_TEXTEDIT_GETPREVCHARINDEX(str, state.cursor)
            end
        end

        state.has_preferred_x = false
    elseif key == STB_TEXTEDIT_K_RIGHT then
        -- if currently there's a selection, move cursor to end of selection
        if STB_TEXT_HAS_SELECTION(state) then
            stb_textedit_move_to_last(str, state)
        else
            state.cursor = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, state.cursor)
        end

        stb_textedit_clamp(str, state)
        state.has_preferred_x = false
    elseif key == bit32.bor(STB_TEXTEDIT_K_LEFT, STB_TEXTEDIT_K_SHIFT) then
        stb_textedit_clamp(str, state)
        stb_textedit_prep_selection_at_cursor(state)
        -- move selection left
        if state.select_end > 1 then
            state.select_end = IMSTB_TEXTEDIT_GETPREVCHARINDEX(str, state.select_end)
        end
        state.cursor = state.select_end
        state.has_preferred_x = false
    elseif key == STB_TEXTEDIT_K_WORDLEFT then
        -- if currently there's a selection, move cursor to start of selection
        if STB_TEXT_HAS_SELECTION(state) then
            stb_textedit_move_to_first(state)
        else
            state.cursor = STB_TEXTEDIT_MOVEWORDLEFT(str, state.cursor)
            stb_textedit_clamp(str, state)
        end
    elseif key == bit32.bor(STB_TEXTEDIT_K_WORDLEFT, STB_TEXTEDIT_K_SHIFT) then
        if not STB_TEXT_HAS_SELECTION(state) then
            stb_textedit_prep_selection_at_cursor(state)
        end

        state.cursor = STB_TEXTEDIT_MOVEWORDLEFT(str, state.cursor)
        state.select_end = state.cursor

        stb_textedit_clamp(str, state)
    elseif key == STB_TEXTEDIT_K_WORDRIGHT then
        -- if currently there's a selection, move cursor to end of selection
        if STB_TEXT_HAS_SELECTION(state) then
            stb_textedit_move_to_last(str, state)
        else
            state.cursor = STB_TEXTEDIT_MOVEWORDRIGHT(str, state.cursor)
            stb_textedit_clamp(str, state)
        end
    elseif key == bit32.bor(STB_TEXTEDIT_K_WORDRIGHT, STB_TEXTEDIT_K_SHIFT) then
        if not STB_TEXT_HAS_SELECTION(state) then
            stb_textedit_prep_selection_at_cursor(state)
        end

        state.cursor = STB_TEXTEDIT_MOVEWORDRIGHT(str, state.cursor)
        state.select_end = state.cursor

        stb_textedit_clamp(str, state)
    elseif key == bit32.bor(STB_TEXTEDIT_K_RIGHT, STB_TEXTEDIT_K_SHIFT) then
        stb_textedit_prep_selection_at_cursor(state)
        -- move selection right
        state.select_end = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, state.select_end)
        stb_textedit_clamp(str, state)
        state.cursor = state.select_end
        state.has_preferred_x = false
    elseif key == STB_TEXTEDIT_K_DOWN
        or key == bit32.bor(STB_TEXTEDIT_K_DOWN, STB_TEXTEDIT_K_SHIFT)
        or key == STB_TEXTEDIT_K_PGDOWN
        or key == bit32.bor(STB_TEXTEDIT_K_PGDOWN, STB_TEXTEDIT_K_SHIFT) then

        StbFindState_Reset(find)
        StbTexteditRow_Reset(row)
        local sel = (bit32.band(key, STB_TEXTEDIT_K_SHIFT) ~= 0)
        local is_page = (bit32.band(key, bit32.bnot(STB_TEXTEDIT_K_SHIFT)) == STB_TEXTEDIT_K_PGDOWN)
        local row_count = is_page and state.row_count_per_page or 1

        if not is_page and state.single_line then
            -- on windows, up&down in single-line behave like left&right
            key = bit32.bor(STB_TEXTEDIT_K_RIGHT, bit32.band(key, STB_TEXTEDIT_K_SHIFT))
            return stb_textedit_key(str, state, key) -- was `goto retry`
        end

        if sel then
            stb_textedit_prep_selection_at_cursor(state)
        elseif STB_TEXT_HAS_SELECTION(state) then
            stb_textedit_move_to_last(str, state)
        end

        -- compute current position of cursor point
        stb_textedit_clamp(str, state)
        stb_textedit_find_charpos(find, str, state.cursor, state.single_line)

        for j = 1, row_count do
            local goal_x = state.has_preferred_x and state.preferred_x or find.x
            local x
            local start = find.first_char + find.length

            if find.length == 0 then
                break
            end

            -- [DEAR IMGUI]
            -- going down while being on the last line shouldn't bring us to that line end
            --if STB_TEXTEDIT_GETCHAR(str, find.first_char + find.length - 1) ~= STB_TEXTEDIT_NEWLINE then
            --   break
            --end

            -- now find character position down a row
            state.cursor = start
            STB_TEXTEDIT_LAYOUTROW(row, str, state.cursor)
            x = row.x0
            local i = 1
            while i <= row.num_chars do
                local dx = STB_TEXTEDIT_GETWIDTH(str, start, i)
                local next = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, state.cursor)
                x = x + dx
                if x > goal_x then
                    break
                end
                i = i + (next - state.cursor)
                state.cursor = next
            end
            stb_textedit_clamp(str, state)

            if state.cursor == find.first_char + find.length then
                str.LastMoveDirectionLR = ImGuiDir.Left
            end
            state.has_preferred_x = true
            state.preferred_x = goal_x

            if sel then
                state.select_end = state.cursor
            end

            -- go to next line
            find.first_char = find.first_char + find.length
            find.length = row.num_chars
        end
    elseif key == STB_TEXTEDIT_K_UP
        or key == bit32.bor(STB_TEXTEDIT_K_UP, STB_TEXTEDIT_K_SHIFT)
        or key == STB_TEXTEDIT_K_PGUP
        or key == bit32.bor(STB_TEXTEDIT_K_PGUP, STB_TEXTEDIT_K_SHIFT) then

        StbFindState_Reset(find)
        StbTexteditRow_Reset(row)
        local sel = (bit32.band(key, STB_TEXTEDIT_K_SHIFT) ~= 0)
        local is_page = (bit32.band(key, bit32.bnot(STB_TEXTEDIT_K_SHIFT)) == STB_TEXTEDIT_K_PGUP)
        local row_count = is_page and state.row_count_per_page or 1

        if not is_page and state.single_line then
            -- on windows, up&down become left&right
            key = bit32.bor(STB_TEXTEDIT_K_LEFT, bit32.band(key, STB_TEXTEDIT_K_SHIFT))
            return stb_textedit_key(str, state, key) -- was `goto retry`
        end

        if sel then
            stb_textedit_prep_selection_at_cursor(state)
        elseif STB_TEXT_HAS_SELECTION(state) then
            stb_textedit_move_to_first(state)
        end

        -- compute current position of cursor point
        stb_textedit_clamp(str, state)
        stb_textedit_find_charpos(find, str, state.cursor, state.single_line)

        for j = 1, row_count do
            local goal_x
            if state.has_preferred_x then
                goal_x = state.preferred_x
            else
                goal_x = find.x
            end
            local x

            -- can only go up if there's a previous row
            if find.prev_first == find.first_char then
                break
            end

            -- now find character position up a row
            state.cursor = find.prev_first
            STB_TEXTEDIT_LAYOUTROW(row, str, state.cursor)
            x = row.x0
            local i = 1
            while i <= row.num_chars do
                local dx = STB_TEXTEDIT_GETWIDTH(str, find.prev_first, i)
                local next = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, state.cursor)
                x = x + dx
                if x > goal_x then
                    break
                end
                i = i + (next - state.cursor)
                state.cursor = next
            end
            stb_textedit_clamp(str, state)

            if state.cursor == find.first_char then
                str.LastMoveDirectionLR = ImGuiDir.Right
            elseif state.cursor == find.prev_first then
                str.LastMoveDirectionLR = ImGuiDir.Left
            end
            state.has_preferred_x = true
            state.preferred_x = goal_x

            if sel then
                state.select_end = state.cursor
            end

            -- go to previous line
            -- (we need to scan previous line the hard way. maybe we could expose this as a new API function?)
            local prev_scan = find.prev_first > 1 and find.prev_first - 1 or 1
            while prev_scan > 1 do
                local prev = IMSTB_TEXTEDIT_GETPREVCHARINDEX(str, prev_scan)
                if STB_TEXTEDIT_GETCHAR(str, prev) == STB_TEXTEDIT_NEWLINE then
                    break
                end
                prev_scan = prev
            end
            find.first_char = find.prev_first
            find.prev_first = STB_TEXTEDIT_MOVELINESTART(str, state, prev_scan)
        end
    elseif key == STB_TEXTEDIT_K_DELETE
        or key == bit32.bor(STB_TEXTEDIT_K_DELETE, STB_TEXTEDIT_K_SHIFT) then

        if STB_TEXT_HAS_SELECTION(state) then
            stb_textedit_delete_selection(str, state)
        else
            local n = STB_TEXTEDIT_STRINGLEN(str)
            if state.cursor <= n then
                stb_textedit_delete(str, state, state.cursor, IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, state.cursor) - state.cursor)
            end
        end
        state.has_preferred_x = false
    elseif key == STB_TEXTEDIT_K_BACKSPACE
        or key == bit32.bor(STB_TEXTEDIT_K_BACKSPACE, STB_TEXTEDIT_K_SHIFT) then

        if STB_TEXT_HAS_SELECTION(state) then
            stb_textedit_delete_selection(str, state)
        else
            stb_textedit_clamp(str, state)
            if state.cursor > 1 then
                local prev = IMSTB_TEXTEDIT_GETPREVCHARINDEX(str, state.cursor)
                stb_textedit_delete(str, state, prev, state.cursor - prev)
                state.cursor = prev
            end
        end
        state.has_preferred_x = false
    elseif key == STB_TEXTEDIT_K_TEXTSTART then
        state.cursor = 1
        state.select_start = 1
        state.select_end = 1
        state.has_preferred_x = false
    elseif key == STB_TEXTEDIT_K_TEXTEND then
        state.cursor = STB_TEXTEDIT_STRINGLEN(str) + 1
        state.select_start = 1
        state.select_end = 1
        state.has_preferred_x = false
    elseif key == bit32.bor(STB_TEXTEDIT_K_TEXTSTART, STB_TEXTEDIT_K_SHIFT) then
        stb_textedit_prep_selection_at_cursor(state)
        state.cursor = 1
        state.select_end = 1
        state.has_preferred_x = false
    elseif key == bit32.bor(STB_TEXTEDIT_K_TEXTEND, STB_TEXTEDIT_K_SHIFT) then
        stb_textedit_prep_selection_at_cursor(state)
        state.cursor = STB_TEXTEDIT_STRINGLEN(str) + 1
        state.select_end = state.cursor
        state.has_preferred_x = false
    elseif key == STB_TEXTEDIT_K_LINESTART then
        stb_textedit_clamp(str, state)
        stb_textedit_move_to_first(state)
        state.cursor = STB_TEXTEDIT_MOVELINESTART(str, state, state.cursor)
        state.has_preferred_x = false
    elseif key == STB_TEXTEDIT_K_LINEEND then
        stb_textedit_clamp(str, state)
        stb_textedit_move_to_last(str, state)
        state.cursor = STB_TEXTEDIT_MOVELINEEND(str, state, state.cursor)
        state.has_preferred_x = false
    elseif key == bit32.bor(STB_TEXTEDIT_K_LINESTART, STB_TEXTEDIT_K_SHIFT) then
        stb_textedit_clamp(str, state)
        stb_textedit_prep_selection_at_cursor(state)
        state.cursor = STB_TEXTEDIT_MOVELINESTART(str, state, state.cursor)
        state.select_end = state.cursor
        state.has_preferred_x = false
    elseif key == bit32.bor(STB_TEXTEDIT_K_LINEEND, STB_TEXTEDIT_K_SHIFT) then
        stb_textedit_clamp(str, state)
        stb_textedit_prep_selection_at_cursor(state)
        state.cursor = STB_TEXTEDIT_MOVELINEEND(str, state, state.cursor)
        state.select_end = state.cursor
        state.has_preferred_x = false
    end
end

end

-----------------------------------------------------
-----------------------------------------------------
---
--- Undo processing
---
--- @OPTIMIZE: the undo/redo buffer should be circular

--- @param state StbUndoState
local function stb_textedit_flush_redo(state)
    state.redo_point = IMSTB_TEXTEDIT_UNDOSTATECOUNT + 1
    state.redo_char_point = IMSTB_TEXTEDIT_UNDOCHARCOUNT + 1
end

-- discard the oldest entry in the undo list
--- @param state StbUndoState
local function stb_textedit_discard_undo(state)
    if state.undo_point > 0 then
        -- if the 1th undo state has characters, clean those up
        if state.undo_rec[1].char_storage >= 0 then
            local n = state.undo_rec[1].insert_length
            -- delete n characters from all other records
            state.undo_char_point = state.undo_char_point - n
            IMSTB_TEXTEDIT_memmove(state.undo_char, 1, state.undo_char, n + 1, state.undo_char_point - 1)
            for i = 1, state.undo_point do
                if state.undo_rec[i].char_storage >= 0 then
                    state.undo_rec[i].char_storage = state.undo_rec[i].char_storage - n -- @OPTIMIZE: get rid of char_storage and infer it
                end
            end
        end
        state.undo_point = state.undo_point - 1
        IMSTB_TEXTEDIT_memmove(state.undo_rec, 1, state.undo_rec, 2, state.undo_point - 1)
    end
end

-- discard the oldest entry in the redo list--it's bad if this
-- ever happens, but because undo & redo have to store the actual
-- characters in different cases, the redo character buffer can
-- fill up even though the undo buffer didn't
--- @param state StbUndoState
local function stb_textedit_discard_redo(state)
    local k = IMSTB_TEXTEDIT_UNDOSTATECOUNT

    if state.redo_point <= k then
        -- if the k'th undo state has characters, clean those up
        if state.undo_rec[k].char_storage >= 1 then
            local n = state.undo_rec[k].insert_length
            -- move the remaining redo character data to the end of the buffer
            state.redo_char_point = state.redo_char_point + n
            IMSTB_TEXTEDIT_memmove(state.undo_char, state.redo_char_point, state.undo_char, state.redo_char_point - n, IMSTB_TEXTEDIT_UNDOCHARCOUNT - state.redo_char_point + 1)
            -- adjust the position of all the other records to account for above memmove
            for i = state.redo_point, k - 1 do
                if state.undo_rec[i].char_storage >= 1 then
                    state.undo_rec[i].char_storage = state.undo_rec[i].char_storage + n
                end
            end
        end

        -- now move all the redo records towards the end of the buffer; the first one is at 'redo_point'
        -- [DEAR IMGUI]
        local move_size = IMSTB_TEXTEDIT_UNDOSTATECOUNT - state.redo_point - 1
        IMSTB_TEXTEDIT_memmove(state.undo_rec, state.redo_point + 1, state.undo_rec, state.redo_point, move_size)

        -- now move redo_point to point to the new one
        state.redo_point = state.redo_point + 1
    end
end

--- @param state    StbUndoState
--- @param numchars int
local function stb_text_create_undo_record(state, numchars)
    -- any time we create a new undo record, we discard redo
    stb_textedit_flush_redo(state)

    -- if we have no free records, we have to make room, by sliding the
    -- existing records down
    if state.undo_point == IMSTB_TEXTEDIT_UNDOSTATECOUNT then
        stb_textedit_discard_undo(state)
    end

    -- if the characters to store won't possibly fit in the buffer, we can't undo
    if numchars > IMSTB_TEXTEDIT_UNDOCHARCOUNT then
        state.undo_point = 1
        state.undo_char_point = 1
        return nil
    end

    -- if we don't have enough free characters in the buffer, we have to make room
    while state.undo_char_point + numchars > IMSTB_TEXTEDIT_UNDOCHARCOUNT do
        stb_textedit_discard_undo(state)
    end

    local ret = state.undo_rec[state.undo_point]
    state.undo_point = state.undo_point + 1
    return ret
end

--- @param state      StbUndoState
--- @param pos        int
--- @param insert_len int
--- @param delete_len int
--- @return int? # index into undostate.undo_char[]
local function stb_text_createundo(state, pos, insert_len, delete_len)
    local r = stb_text_create_undo_record(state, insert_len)
    if r == nil then
        return nil
    end

    r.where = pos
    r.insert_length = insert_len
    r.delete_length = delete_len

    if insert_len == 0 then
        r.char_storage = -1
        return nil
    else
        r.char_storage = state.undo_char_point
        state.undo_char_point = state.undo_char_point + insert_len
        return r.char_storage
    end
end

--- @param str   IMSTB_TEXTEDIT_STRING
--- @param state STB_TexteditState
function stb_text_undo(str, state)
    local s = state.undostate

    if s.undo_point == 1 then
        return
    end

    -- we need to do two things: apply the undo record, and create a redo record
    local u = s.undo_rec[s.undo_point - 1]
    local r = s.undo_rec[s.redo_point - 1]
    r.char_storage = -1

    r.insert_length = u.delete_length
    r.delete_length = u.insert_length
    r.where = u.where

    if u.delete_length > 0 then
        -- if the undo record says to delete characters, then the redo record will
        -- need to re-insert the characters that get deleted, so we need to store
        -- them.

        -- there are three cases:
        --    there's enough room to store the characters
        --    characters stored for *redoing* don't leave room for redo
        --    characters stored for *undoing* don't leave room for redo
        -- if the last is true, we have to bail

        if s.undo_char_point + u.delete_length > IMSTB_TEXTEDIT_UNDOCHARCOUNT then
            -- the undo records take up too much character space; there's no space to store the redo characters
            r.insert_length = 0
        else
            -- there's definitely room to store the characters eventually
            while s.undo_char_point + u.delete_length > s.redo_char_point do
                -- should never happen:
                if s.redo_point == IMSTB_TEXTEDIT_UNDOSTATECOUNT + 1 then
                    return
                end

                -- there's currently not enough room, so discard a redo record
                stb_textedit_discard_redo(s)
            end
            r = s.undo_rec[s.redo_point - 1]

            r.char_storage = s.redo_char_point - u.delete_length
            s.redo_char_point = s.redo_char_point - u.delete_length

            -- now save the characters
            for i = 0, u.delete_length - 1 do
                s.undo_char[r.char_storage + i] = STB_TEXTEDIT_GETCHAR(str, u.where + i)
            end
        end

        -- now we can carry out the deletion
        STB_TEXTEDIT_DELETECHARS(str, u.where, u.delete_length)
    end

    -- check type of recorded action:
    if u.insert_length > 0 then
        -- easy case: was a deletion, so we need to insert n characters
        u.insert_length = STB_TEXTEDIT_INSERTCHARS(str, u.where, s.undo_char, u.char_storage, u.insert_length)
        s.undo_char_point = s.undo_char_point - u.insert_length
    end

    state.cursor = u.where + u.insert_length

    s.undo_point = s.undo_point - 1
    s.redo_point = s.redo_point - 1
end

--- @param str   IMSTB_TEXTEDIT_STRING
--- @param state STB_TexteditState
function stb_text_redo(str, state)
    local s = state.undostate
    if s.undo_point == IMSTB_TEXTEDIT_UNDOSTATECOUNT + 1 then
        return
    end

    -- we need to do two things: apply the redo record, and create an undo record
    local u = s.undo_rec[s.undo_point]
    local r = s.undo_rec[s.redo_point]

    -- we KNOW there must be room for the undo record, because the redo record
    -- was derived from an undo record

    u.delete_length = r.insert_length
    u.insert_length = r.delete_length
    u.where = r.where
    u.char_storage = -1

    if r.delete_length > 0 then
        -- the redo record requires us to delete characters, so the undo record
        -- needs to store the characters

        if s.undo_char_point + u.insert_length > s.redo_char_point then
            u.insert_length = 0
            u.delete_length = 0
        else
            u.char_storage = s.undo_char_point
            s.undo_char_point = s.undo_char_point + u.insert_length

            -- now save the characters
            for i = 0, u.insert_length - 1 do
                s.undo_char[u.char_storage + i] = STB_TEXTEDIT_GETCHAR(str, u.where + i)
            end
        end

        STB_TEXTEDIT_DELETECHARS(str, r.where, r.delete_length)
    end

    if r.insert_length ~= 0 then
        -- easy case: need to insert n characters
        r.insert_length = STB_TEXTEDIT_INSERTCHARS(str, r.where, s.undo_char, r.char_storage, r.insert_length)
        s.redo_char_point = s.redo_char_point + r.insert_length
    end

    state.cursor = r.where + r.insert_length

    s.undo_point = s.undo_point + 1
    s.redo_point = s.redo_point + 1
end

--- @param state  STB_TexteditState
--- @param where  int
--- @param length int
function stb_text_makeundo_insert(state, where, length)
    stb_text_createundo(state.undostate, where, 0, length)
end

--- @param str    IMSTB_TEXTEDIT_STRING
--- @param state  STB_TexteditState
--- @param where  int
--- @param length int
function stb_text_makeundo_delete(str, state, where, length)
    local s = state.undostate
    local p = stb_text_createundo(s, where, length, 0)
    if p then
        for i = 0, length - 1 do
            s.undo_char[p + i] = STB_TEXTEDIT_GETCHAR(str, where + i)
        end
    end
end

--- @param str        IMSTB_TEXTEDIT_STRING
--- @param state      STB_TexteditState
--- @param where      int
--- @param old_length int
--- @param new_length int
function stb_text_makeundo_replace(str, state, where, old_length, new_length)
    local s = state.undostate
    local p = stb_text_createundo(s, where, old_length, new_length)
    if p then
        for i = 0, old_length - 1 do
            s.undo_char[p + i] = STB_TEXTEDIT_GETCHAR(str, where + i)
        end
    end
end

-- reset the state to default
--- @param state          STB_TexteditState
--- @param is_single_line bool
local function stb_textedit_clear_state(state, is_single_line)
    state.undostate.undo_point = 1
    state.undostate.undo_char_point = 1
    state.undostate.redo_point = IMSTB_TEXTEDIT_UNDOSTATECOUNT + 1
    state.undostate.redo_char_point = IMSTB_TEXTEDIT_UNDOCHARCOUNT + 1
    state.select_end = 1
    state.select_start = 1
    state.cursor = 1
    state.has_preferred_x = false
    state.preferred_x = 0
    state.cursor_at_end_of_line = false
    state.initialized = true
    state.single_line = is_single_line
    state.insert_mode = false
    state.row_count_per_page = 0
end

return {
    click = stb_textedit_click,
    drag = stb_textedit_drag,
    createundo = stb_text_createundo,
    initialize_state = stb_textedit_clear_state, -- API initialize

    text = stb_textedit_text,
    key = stb_textedit_key,

    makeundo_replace = stb_text_makeundo_replace,

    clamp = stb_textedit_clamp,
    prep_selection_at_cursor = stb_textedit_prep_selection_at_cursor,
    cut = stb_textedit_cut,
    paste = stb_textedit_paste_internal,

    HAS_SELECTION = STB_TEXT_HAS_SELECTION
}

-------------------------------------------------------------------------------
-- This software is available under 2 licenses -- choose whichever you prefer.
-------------------------------------------------------------------------------
-- ALTERNATIVE A - MIT License
-- Copyright (c) 2017 Sean Barrett
-- Permission is hereby granted, free of charge, to any person obtaining a copy of
-- this software and associated documentation files (the "Software"), to deal in
-- the Software without restriction, including without limitation the rights to
-- use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
-- of the Software, and to permit persons to whom the Software is furnished to do
-- so, subject to the following conditions:
-- The above copyright notice and this permission notice shall be included in all
-- copies or substantial portions of the Software.
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-- SOFTWARE.
-------------------------------------------------------------------------------
-- ALTERNATIVE B - Public Domain (www.unlicense.org)
-- This is free and unencumbered software released into the public domain.
-- Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
-- software, either in source code form or as a compiled binary, for any purpose,
-- commercial or non-commercial, and by any means.
-- In jurisdictions that recognize copyright laws, the author or authors of this
-- software dedicate any and all copyright interest in the software to the public
-- domain. We make this dedication for the benefit of the public at large and to
-- the detriment of our heirs and successors. We intend this dedication to be an
-- overt act of relinquishment in perpetuity of all present and future rights to
-- this software under copyright law.
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
-- ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
-- WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-------------------------------------------------------------------------------
end

__FILES['imstb_truetype.lua'] = function()
--- Dear ImGui
-- This is a Lua port of original `imstb_truetype.h`

-- [DEAR IMGUI]
-- This is a slightly modified version of stb_truetype.h 1.26.
-- Mostly fixing for compiler and static analyzer warnings.
-- Grep for [DEAR IMGUI] to find the changes.

-- stb_truetype.h - v1.26 - public domain
-- authored from 2009-2021 by Sean Barrett / RAD Game Tools
--
-- =======================================================================
--
--    NO SECURITY GUARANTEE -- DO NOT USE THIS ON UNTRUSTED FONT FILES
--
-- This library does no range checking of the offsets found in the file,
-- meaning an attacker can use it to read arbitrary memory.
--
-- =======================================================================
--
--   This library processes TrueType files:
--        parse files
--        extract glyph metrics
--        extract glyph shapes
--        render glyphs to one-channel bitmaps with antialiasing (box filter)
--
--   Todo:
--        non-MS cmaps
--        crashproof on bad data
--        hinting? (no longer patented)
--        cleartype-style AA?
--        optimize: build edge-list directly from curves
--        optimize: rasterize directly from curves?
--
-- ADDITIONAL CONTRIBUTORS
--
--   Mikko Mononen: compound shape support, more cmap formats
--   Tor Andersson: kerning, subpixel rendering
--   Dougall Johnson: OpenType / Type 2 font handling
--   Daniel Ribeiro Maciel: basic GPOS-based kerning
--
--   Misc other:
--       Ryan Gordon
--       Simon Glass
--       github:IntellectualKitty
--       Imanol Celaya
--       Daniel Ribeiro Maciel
--
--   Bug/warning reports/fixes:
--       "Zer" on mollyrocket       Fabian "ryg" Giesen   github:NiLuJe
--       Cass Everitt               Martins Mozeiko       github:aloucks
--       stoiko (Haemimont Games)   Cap Petschulat        github:oyvindjam
--       Brian Hook                 Omar Cornut           github:vassvik
--       Walter van Niftrik         Ryan Griege
--       David Gow                  Peter LaValle
--       David Given                Sergey Popov
--       Ivan-Assen Ivanov          Giumo X. Clanjor
--       Anthony Pesch              Higor Euripedes
--       Johan Duparc               Thomas Fields
--       Hou Qiming                 Derek Vinyard
--       Rob Loach                  Cort Stratton
--       Kenney Phillis Jr.         Brian Costabile
--       Ken Voskuil (kaesve)
--
-- USAGE
--
--   "Load" a font file from a memory buffer (you have to keep the buffer loaded)
--           stbtt_InitFont()
--           stbtt_GetFontOffsetForIndex()        -- indexing for TTC font collections
--
--   Character advance/positioning
--           stbtt_GetFontVMetrics()
--
--   Starting with version 1.06, the rasterizer was replaced with a new,
--   faster and generally-more-precise rasterizer. The new rasterizer more
--   accurately measures pixel coverage for anti-aliasing, except in the case
--   where multiple shapes overlap, in which case it overestimates the AA pixel
--   coverage. Thus, anti-aliasing of intersecting shapes may look wrong.
--   (This port only implements the new rasterizer.)
--
-- ADDITIONAL DOCUMENTATION
--
--   Some important concepts to understand to use this library:
--
--      Codepoint
--         Characters are defined by unicode codepoints, e.g. 65 is
--         uppercase A, 231 is lowercase c with a cedilla, 0x7e30 is
--         the hiragana for "ma".
--
--      Glyph
--         A visual character shape (every codepoint is rendered as
--         some glyph)
--
--      Glyph index
--         A font-specific integer ID representing a glyph
--
--      Baseline
--         Glyph shapes are defined relative to a baseline, which is the
--         bottom of uppercase characters. Characters extend both above
--         and below the baseline.
--
--      Current Point
--         As you draw text to the screen, you keep track of a "current point"
--         which is the origin of each character. The current point's vertical
--         position is the baseline. Even "baked fonts" use this model.
--
--      Vertical Font Metrics
--         The vertical qualities of the font, used to vertically position
--         and space the characters. See docs for stbtt_GetFontVMetrics.
--
--      Font Size in Pixels or Points
--         The preferred interface for specifying font sizes in stb_truetype
--         is to specify how tall the font's vertical extent should be in pixels.
--
-- DETAILED USAGE:
--
--  Scale:
--    Select how high you want the font to be, in pixels.
--    Call ScaleForPixelHeight to compute a scale factor SF that will be
--    used by all other functions.
--
--  Current point:
--    Set the current point where the first character will appear. The
--    first character could extend left of the current point; this is font
--    dependent. You can either choose a current point that is the leftmost
--    point and hope, or add some padding, or check the bounding box or
--    left-side-bearing of the first character to be displayed and set
--    the current point based on that.
--
--  Displaying a character:
--    Compute the bounding box of the character. It will contain signed values
--    relative to <current_point, baseline>. I.e. if it returns x0,y0,x1,y1,
--    then the character should be displayed in the rectangle from
--    <current_point+SF*x0, baseline+SF*y0> to <current_point+SF*x1,baseline+SF*y1).
--
--  Advancing for the next character:
--    Call GlyphHMetrics, and compute 'current_point += SF * advance'.
--
--
-- ADVANCED USAGE
--
--   Quality:
--
--    - Use the functions with Subpixel at the end to allow your characters
--      to have subpixel positioning. Since the font is anti-aliased, not
--      hinted, this is very import for quality. (This is not possible with
--      baked fonts.)
--
--   Performance:
--
--    - Convert Unicode codepoints to glyph indexes and operate on the glyphs;
--      if you don't do this, stb_truetype is forced to do the conversion on
--      every call.
--
-- NOTES
--
--   The system uses the raw data found in the .ttf file without changing it
--   and without building auxiliary data structures. This is a bit inefficient
--   on little-endian systems (the data is big-endian), but assuming you're
--   caching the bitmaps or glyph shapes this shouldn't be a big deal.

--- STBTT_RASTERIZER_VERSION == 2

local stbtt_fontinfo

local stbtt_InitFont
local stbtt_MakeGlyphBitmapSubpixelPrefilter
local stbtt_GetFontVMetrics
local stbtt__GetGlyphInfoT2
local stbtt__GetGlyphShapeT2
local stbtt_GetGlyphShape
local stbtt_GetGlyphBitmapBox
local stbtt_GetGlyphBitmapBoxSubpixel
local stbtt_GetGlyphHMetrics
local stbtt_GetFontOffsetForIndex
local stbtt_ScaleForPixelHeight
local stbtt_FindGlyphIndex

local STBTT_MAX_OVERSAMPLE = 8

--- @enum STBTT_PLATFORM_ID
local STBTT_PLATFORM_ID = { -- platformID
    UNICODE   = 0,
    MAC       = 1,
    ISO       = 2,
    MICROSOFT = 3,
}

--- @enum STBTT_MS_EID
local STBTT_MS_EID = { -- encodingID for STBTT_PLATFORM_ID_MICROSOFT
    SYMBOL       = 0,
    UNICODE_BMP  = 1,
    SHIFTJIS     = 2,
    UNICODE_FULL = 10
}

-- original enum doesn't have a name, so we name it
--- @enum STBTT_VTX
local STBTT_VTX = {
    MOVE = 1,
    LINE = 2,
    CURVE = 3,
    CUBIC = 4
}

local bit32 = bit32
local math = math

local STBTT_assert = assert
local STBTT_sort = table.sort
local STBTT_sqrt = math.sqrt
local STBTT_fabs = math.abs
local STBTT_ifloor = math.floor
local STBTT_iceil = math.ceil

local trunc = function(x)
    if x >= 0 then
        return math.floor(x)
    else
        return math.ceil(x)
    end
end

local function STBTT__NOTUSED(_) return end

--- @alias stbtt_int32 int

local stbtt_int32   = ImS32
local stbtt_uint32  = ImU32
local stbtt_int16   = ImS16
local stbtt_uint16  = ImU16
local stbtt_int8    = ImS8
local stbtt_uint8   = ImU8
local unsigned_char = stbtt_uint8

-- private structure
--- @class stbtt__buf
--- @field data?  table # 1-based byte table
--- @field offset int   # Every access to `data` will be offset by this
--- @field cursor int   # >= 0
--- @field size   int

--- @param initial_offset? int
--- @return stbtt__buf
--- @nodiscard
local function stbtt__buf(initial_offset)
    return {
        data   = nil,
        offset = initial_offset or 0,
        cursor = 0,
        size   = nil
    }
end

-- The following structure is defined publicly so you can declare one on
-- the stack or as a global or etc, but you should treat it as opaque.
--- @class stbtt_fontinfo
--- @field userdata         any
--- @field data             table       # pointer to .ttf file
--- @field fontstart        int         # offset of start of font
--- @field numGlyphs        int         # number of glyphs, needed for range checking
--- @field loca             int         # table location as offset from start of .ttf
--- @field head             int         # table location as offset from start of .ttf
--- @field glyf             int         # table location as offset from start of .ttf
--- @field hhea             int         # table location as offset from start of .ttf
--- @field hmtx             int         # table location as offset from start of .ttf
--- @field kern             int         # table location as offset from start of .ttf
--- @field gpos             int         # table location as offset from start of .ttf
--- @field svg              int         # table location as offset from start of .ttf
--- @field index_map        int         # a cmap mapping for our chosen character encoding
--- @field indexToLocFormat int         # format needed to map from glyph index to glyph
--- @field cff              stbtt__buf  # cff font data
--- @field charstrings      stbtt__buf  # the charstring index
--- @field gsubrs           stbtt__buf  # global charstring subroutines index
--- @field subrs            stbtt__buf  # private charstring subroutines index
--- @field fontdicts        stbtt__buf  # array of font dicts
--- @field fdselect         stbtt__buf  # map from glyph to fontdict

--- @return stbtt_fontinfo
function stbtt_fontinfo()
    return {
        data      = nil,
        fontstart = nil,

        numGlyphs = nil,

        loca = nil,
        head = nil,
        glyf = nil,
        hhea = nil,
        hmtx = nil,
        kern = nil,
        gpos = nil,
        svg  = nil,

        index_map        = nil,
        indexToLocFormat = nil,

        cff         = nil,
        charstrings = nil,
        gsubrs      = nil,
        subrs       = nil,
        fontdicts   = nil,
        fdselect    = nil
    }
end

--- @class stbtt_vertex
--- @field x       int
--- @field y       int
--- @field cx      int
--- @field cy      int
--- @field cx1     int
--- @field cy1     int
--- @field type    int
--- @field padding int

--- @return stbtt_vertex
--- @nodiscard
local function stbtt_vertex()
    return {
        x       = nil,
        y       = nil,
        cx      = nil,
        cy      = nil,
        cx1     = nil,
        cy1     = nil,
        type    = nil,
        padding = nil
    }
end

--- @class stbtt__csctx
--- @field bounds       bool
--- @field started      bool
--- @field first_x      float
--- @field first_y      float
--- @field x            float
--- @field y            float
--- @field min_x        int
--- @field max_x        int
--- @field min_y        int
--- @field max_y        int
--- @field pvertices    stbtt_vertex[]
--- @field num_vertices int

--- @return stbtt__csctx
--- @nodiscard
local function stbtt__csctx()
    return {
        bounds  = false,
        started = false,
        first_x = nil,
        first_y = nil,
        x       = nil,
        y       = nil,
        min_x   = nil,
        max_x   = nil,
        min_y   = nil,
        max_y   = nil,

        pvertices    = nil,
        num_vertices = nil
    }
end

--- @param bounds bool
--- @return stbtt__csctx
--- @nodiscard
local function STBTT__CSCTX_INIT(bounds)
    local this = stbtt__csctx()

    this.bounds  = bounds
    this.started = false
    this.first_x = 0
    this.first_y = 0
    this.x       = 0
    this.y       = 0
    this.min_x   = 0
    this.max_x   = 0
    this.min_y   = 0
    this.max_y   = 0

    this.pvertices = nil
    this.num_vertices = 0

    return this
end

--- stbtt_kerningentry
--- stbtt_pack_range
--- stbtt_packedchar

--- @class stbtt__edge
--- @field x0     float
--- @field y0     float
--- @field x1     float
--- @field y1     float
--- @field invert bool

--- @return stbtt__edge
--- @nodiscard
local function stbtt__edge()
    return {
        x0 = nil,
        y0 = nil,
        x1 = nil,
        y1 = nil,
        invert = false
    }
end

--- @class stbtt__active_edge

--- @return stbtt__active_edge
--- @nodiscard
local function stbtt__active_edge()
    return {
        next = nil,
        fx = nil,
        fdx = nil,
        fdy = nil,
        direction = nil,
        sy = nil,
        ey = nil
    }
end

--- @return stbtt__active_edge
--- @nodiscard
local function stbtt__new_active(e, off_x, start_point)
    local z = stbtt__active_edge()
    local dxdy = (e.x1 - e.x0) / (e.y1 - e.y0)

    z.fdx = dxdy
    z.fdy = (dxdy ~= 0.0) and (1.0 / dxdy) or 0.0
    z.fx = e.x0 + dxdy * (start_point - e.y0)
    z.fx = z.fx - off_x
    z.direction = (e.invert) and 1.0 or -1.0
    z.sy = e.y0
    z.ey = e.y1
    z.next = nil

    return z
end

-- @TODO: don't expose this structure
--- @class stbtt__bitmap
--- @field w      int
--- @field h      int
--- @field stride int
--- @field pixels unsigned_char[]

--- @return stbtt__bitmap
--- @nodiscard
local function stbtt__bitmap()
    return {
        w      = nil,
        h      = nil,
        stride = nil,
        pixels = nil
    }
end

--- @class stbtt__point
--- @field x number
--- @field y number

--- @return stbtt__point
--- @nodiscard
local function stbtt__point() return { x = nil, y = nil } end

----------------------------------------------
----------------------------------------------
---
--- stbtt__buf helpers to parse data from file
---
---

--- @param b stbtt__buf
local function stbtt__buf_get8(b)
    if b.cursor >= b.size then return 0 end
    local result = b.data[b.offset + b.cursor + 1]
    b.cursor = b.cursor + 1
    return result
end

--- @param b stbtt__buf
local function stbtt__buf_peek8(b)
    if b.cursor >= b.size then return 0 end
    return b.data[b.offset + b.cursor + 1]
end

--- @param b stbtt__buf
--- @param o int
local function stbtt__buf_seek(b, o)
    STBTT_assert(not (o > b.size or o < 0))
    if o > b.size or o < 0 then
        b.cursor = b.size
    else
        b.cursor = o
    end
end

--- @param b stbtt__buf
--- @param o int
local function stbtt__buf_skip(b, o)
    stbtt__buf_seek(b, b.cursor + o)
end

local function stbtt__buf_get(b, n)
    local v = 0
    STBTT_assert(n >= 1 and n <= 4)
    for _ = 1, n do
        v = bit32.bor(bit32.lshift(v, 8), stbtt__buf_get8(b))
    end
    return v
end

--- @param p?      table
--- @param size    int
--- @param offset? int
--- @return stbtt__buf
--- @nodiscard
local function stbtt__new_buf(p, size, offset)
    local r = stbtt__buf(offset)
    STBTT_assert(size < 0x40000000)
    r.data = p
    r.size = trunc(size)
    r.cursor = 0
    return r
end

--- @param b stbtt__buf
local function stbtt__buf_get16(b) return stbtt__buf_get(b, 2) end
--- @param b stbtt__buf
local function stbtt__buf_get32(b) return stbtt__buf_get(b, 4) end

--- @param b stbtt__buf
--- @param o int
--- @param s int
--- @return stbtt__buf
--- @nodiscard
local function stbtt__buf_range(b, o, s)
    local r = stbtt__new_buf(nil, 0)
    if (o < 0 or s < 0 or o > b.size or s > (b.size - o)) then
        return r
    end
    r.data = b.data
    r.offset = b.offset + o
    r.size = s
    return r
end

--- @param b stbtt__buf
local function stbtt__cff_get_index(b)
    local count, start, offsize
    start = b.cursor
    count = stbtt__buf_get16(b)
    if count > 0 then
        offsize = stbtt__buf_get8(b)
        STBTT_assert(offsize >= 1 and offsize <= 4)
        stbtt__buf_skip(b, count * offsize)
        stbtt__buf_skip(b, stbtt__buf_get(b, offsize) - 1)
    end
    return stbtt__buf_range(b, start, b.cursor - start)
end

--- @param b stbtt__buf
local function stbtt__cff_int(b)
    local b0 = stbtt__buf_get8(b)
    if b0 >= 32 and b0 <= 246 then return b0 - 139
    elseif b0 >= 247 and b0 <= 250 then return (b0 - 247) * 256 + stbtt__buf_get8(b) + 108
    elseif b0 >= 251 and b0 <= 254 then return -(b0 - 251) * 256 - stbtt__buf_get8(b) - 108
    elseif b0 == 28 then return stbtt__buf_get16(b)
    elseif b0 == 29 then return stbtt__buf_get32(b)
    end
    STBTT_assert(false)
    return 0
end

--- @param b stbtt__buf
local function stbtt__cff_skip_operand(b)
    local v
    local b0 = stbtt__buf_peek8(b)
    STBTT_assert(b0 >= 28)
    if b0 == 30 then
        stbtt__buf_skip(b, 1)
        while b.cursor < b.size do
            v = stbtt__buf_get8(b)
            if (bit32.band(v, 0xF) == 0xF or bit32.rshift(v, 4) == 0xF) then
                break
            end
        end
    else
        stbtt__cff_int(b)
    end
end

--- @param b stbtt__buf
--- @param key int
--- @return stbtt__buf
--- @nodiscard
local function stbtt__dict_get(b, key)
    stbtt__buf_seek(b, 0)
    while b.cursor < b.size do
        local start = b.cursor
        local _end, op
        while stbtt__buf_peek8(b) >= 28 do
            stbtt__cff_skip_operand(b)
        end
        _end = b.cursor
        op = stbtt__buf_get8(b)
        if op == 12 then op = bit32.bor(stbtt__buf_get8(b), 0x100) end
        if op == key then return stbtt__buf_range(b, start, _end - start) end
    end
    return stbtt__buf_range(b, 0, 0)
end

--- @param b        stbtt__buf
--- @param key      int
--- @param outcount int
--- @return int[]
--- @nodiscard
local function stbtt__dict_get_ints(b, key, outcount)
    local operands = stbtt__dict_get(b, key)
    local out = {}
    for i = 1, outcount do
        if operands.cursor >= operands.size then break end
        out[i] = stbtt__cff_int(operands)
    end
    return out
end

--- @param b stbtt__buf
local function stbtt__cff_index_count(b)
    stbtt__buf_seek(b, 0)
    return stbtt__buf_get16(b)
end

--- @param b stbtt__buf
--- @param i int
--- @return stbtt__buf
--- @nodiscard
local function stbtt__cff_index_get(b, i)
    local count, offsize, start, _end
    stbtt__buf_seek(b, 0)
    count = stbtt__buf_get16(b)
    offsize = stbtt__buf_get8(b)
    STBTT_assert(i >= 0 and i < count)
    STBTT_assert(offsize >= 1 and offsize <= 4)
    stbtt__buf_skip(b, i * offsize)
    start = stbtt__buf_get(b, offsize)
    _end = stbtt__buf_get(b, offsize)
    return stbtt__buf_range(b, 2 + (count + 1) * offsize + start, _end - start)
end

-------------------------------------
-------------------------------------
---
--- accessors to parse data from file
---
---

--- UNIMPLEMENTED / UNUSED:
---     stbtt_IsGlyphEmpty
---     stbtt_GetKerningTableLength
---     stbtt_GetKerningTable
---     stbtt__GetGlyphKernInfoAdvance
---     stbtt__GetCoverageIndex
---     stbtt__GetGlyphClass
---     stbtt__GetGlyphGPOSInfoAdvance
---     stbtt_GetGlyphKernAdvance
---     stbtt_FindSVGDoc
---     stbtt_GetGlyphSVG
---     stbtt_GetCodepointSVG
---     stbtt_GetCodepointKernAdvance
---     stbtt_GetFontVMetricsOS2
---     stbtt_GetCodepointHMetrics
---     stbtt_ScaleForMappingEmToPixels
---     stbtt_GetFontBoundingBox
---     stbtt_GetCodepointBitmapBox
---     stbtt_GetCodepointBitmapBoxSubpixel
---     stbtt_GetCodepointBox
---     stbtt_GetNumberOfFonts_internal
---     stbtt__get_svg

local function ttUSHORT(p, offset) return stbtt_uint16(p[offset + 1] * 256 + p[offset + 2]) end
local function ttSHORT(p, offset)  return stbtt_int16(p[offset + 1] * 256 + p[offset + 2]) end
local function ttULONG(p, offset)  return stbtt_uint32(bit32.lshift(p[offset + 1], 24) + bit32.lshift(p[offset + 2], 16) + bit32.lshift(p[offset + 3], 8) + p[offset + 4]) end
local function ttLONG(p, offset)   return stbtt_int32(bit32.lshift(p[offset + 1], 24) + bit32.lshift(p[offset + 2], 16) + bit32.lshift(p[offset + 3], 8) + p[offset + 4]) end

local function ttBYTE(p, offset) return stbtt_uint8(p[offset + 1]) end
local function ttCHAR(p, offset) return stbtt_int8(p[offset + 1]) end

local function stbtt_tag4(p, c0, c1, c2, c3, offset) offset = offset or 0; return p[offset + 1] == c0 and p[offset + 2] == c1 and p[offset + 3] == c2 and p[offset + 4] == c3 end
local function stbtt_tag(p, str, offset) local c0, c1, c2, c3 = string.byte(str, 1, 4); return stbtt_tag4(p, c0, c1, c2, c3, offset) end

local function stbtt__isfont(font)
    -- check the version number
    if stbtt_tag4(font, 49, 0, 0, 0) then return true end -- TrueType 1
    if stbtt_tag(font, "typ1") then return true end -- TrueType with type 1 font -- we don't support this!
    if stbtt_tag(font, "OTTO") then return true end -- OpenType with CFF
    if stbtt_tag4(font, 0, 1, 0, 0) then return true end -- OpenType 1.0
    if stbtt_tag(font, "true") then return true end -- Apple specification for TrueType fonts
    return false
end

-- @OPTIMIZE: binary search
local function stbtt__find_table(data, font_start, tag)
    local num_tables = ttUSHORT(data, font_start + 4)
    local tabledir = font_start + 12
    for i = 0, num_tables - 1 do
        local loc = tabledir + i * 16
        if stbtt_tag(data, tag, loc + 0) then
            return ttULONG(data, loc + 8)
        end
    end
    return 0
end

local function stbtt_GetFontOffsetForIndex_internal(font_collection, index)
    -- if it's just a font, there's only one valid index
    if stbtt__isfont(font_collection) then
        if index == 0 then return 0 else return -1 end
    end

    -- check if it's a TTC
    if stbtt_tag(font_collection, "ttcf") then
        -- version 1?
        if ttULONG(font_collection, 4) == 0x00010000 or ttULONG(font_collection, 4) == 0x00020000 then
            local n = ttLONG(font_collection, 8)
            if index >= n then
                return -1
            end
            return ttULONG(font_collection, 12 + index * 4)
        end
    end

    return -1
end

--- @param cff      stbtt__buf
--- @param fontdict stbtt__buf
local function stbtt__get_subrs(cff, fontdict)
    local private_loc = stbtt__dict_get_ints(fontdict, 18, 2)
    if (private_loc[2] == 0 or private_loc[1] == 0) then
        return stbtt__new_buf(nil, 0)
    end
    local pdict = stbtt__buf_range(cff, private_loc[2], private_loc[1])
    local subrsoff = stbtt__dict_get_ints(pdict, 19, 1)
    if subrsoff[1] == 0 then
        return stbtt__new_buf(nil, 0)
    end
    stbtt__buf_seek(cff, private_loc[2] + subrsoff[1])
    return stbtt__cff_get_index(cff)
end

--- @return bool
local function stbtt_InitFont_internal(info, data, fontstart)
    local cmap
    local numTables

    info.data = data
    info.fontstart = fontstart
    info.cff = stbtt__new_buf(nil, 0)

    cmap = stbtt__find_table(data, fontstart, "cmap")      -- required
    info.loca = stbtt__find_table(data, fontstart, "loca") -- required
    info.head = stbtt__find_table(data, fontstart, "head") -- required
    info.glyf = stbtt__find_table(data, fontstart, "glyf") -- required
    info.hhea = stbtt__find_table(data, fontstart, "hhea") -- required
    info.hmtx = stbtt__find_table(data, fontstart, "hmtx") -- required
    info.kern = stbtt__find_table(data, fontstart, "kern") -- not required
    info.gpos = stbtt__find_table(data, fontstart, "GPOS") -- not required

    if (cmap == 0 or info.head == 0 or info.hhea == 0 or info.hmtx == 0) then
        return false
    end
    if info.glyf ~= 0 then
        -- required for truetype
        if info.loca == 0 then
            return false
        end
    else
        -- initialization for CFF / Type2 fonts (OTF)
        local cff = stbtt__find_table(data, fontstart, "CFF ")
        if cff == 0 then
            return false
        end

        info.fontdicts = stbtt__new_buf(nil, 0)
        info.fdselect = stbtt__new_buf(nil, 0)

        -- @TODO this should use size from table (not 512MB)
        info.cff = stbtt__new_buf(data, 64 * 1024 * 1024, cff) -- PORT: 64MB here instead of 512MB
        local b = info.cff

        -- read the header
        stbtt__buf_skip(b, 2)
        stbtt__buf_seek(b, stbtt__buf_get8(b)) -- hdrsize

        -- @TODO the name INDEX could list multiple fonts,
        -- but we just use the first one.
        stbtt__cff_get_index(b) -- name INDEX
        local topdictidx = stbtt__cff_get_index(b)
        local topdict = stbtt__cff_index_get(topdictidx, 0)
        stbtt__cff_get_index(b) -- string INDEX
        info.gsubrs = stbtt__cff_get_index(b)

        local charstrings = stbtt__dict_get_ints(topdict, 17, 1)
        local cstype      = stbtt__dict_get_ints(topdict, bit32.bor(0x100, 6), 1)
        local fdarrayoff  = stbtt__dict_get_ints(topdict, bit32.bor(0x100, 36), 1)
        local fdselectoff = stbtt__dict_get_ints(topdict, bit32.bor(0x100, 37), 1)
        info.subrs = stbtt__get_subrs(b, topdict)

        -- we only support Type 2 charstrings
        if cstype[1] ~= 2 then
            return false
        end
        if charstrings[1] == 0 then
            return false
        end

        if fdarrayoff[1] ~= 0 then
            -- looks like a CID font
            if fdselectoff[1] == 0 then
                return false
            end

            stbtt__buf_seek(b, fdarrayoff[1])
            info.fontdicts = stbtt__cff_get_index(b)
            info.fdselect = stbtt__buf_range(b, fdselectoff[1], b.size - fdselectoff[1])
        end

        stbtt__buf_seek(b, charstrings[1])
        info.charstrings = stbtt__cff_get_index(b)
    end

    local t = stbtt__find_table(data, fontstart, "maxp")
    if t ~= 0 then
        info.numGlyphs = ttUSHORT(data, t + 4)
    else
        info.numGlyphs = 0xffff
    end

    info.svg = -1

    -- find a cmap encoding table we understand *now* to avoid searching
    -- later. (todo: could make this installable)
    -- the same regardless of glyph.
    numTables = ttUSHORT(data, cmap + 2)
    info.index_map = 0
    for i = 0, numTables - 1 do
        local encoding_record = cmap + 4 + 8 * i
        -- find an encoding we understand:
        local platform_id = ttUSHORT(data, encoding_record)

        if platform_id == STBTT_PLATFORM_ID.MICROSOFT then
            local ms_eid = ttUSHORT(data, encoding_record + 2)

            if ms_eid == STBTT_MS_EID.UNICODE_BMP or ms_eid == STBTT_MS_EID.UNICODE_FULL then
                -- MS/Unicode
                info.index_map = cmap + ttULONG(data, encoding_record + 4)
            end
        elseif platform_id == STBTT_PLATFORM_ID.UNICODE then
            -- Mac/iOS has these
            -- all the encodingIDs are unicode, so we don't bother to check it
            info.index_map = cmap + ttULONG(data, encoding_record + 4)
        end
    end
    if info.index_map == 0 then
        return false
    end

    info.indexToLocFormat = ttUSHORT(data, info.head + 50)
    return true
end

-- If you're going to perform multiple operations on the same character
-- and you want a speed-up, call this function with the character you're
-- going to process, then use glyph-based functions instead of the
-- codepoint-based functions.
-- Returns 0 if the character codepoint is not defined in the font.
--- @param info              stbtt_fontinfo
--- @param unicode_codepoint int
function stbtt_FindGlyphIndex(info, unicode_codepoint)
    local data = info.data
    local index_map = info.index_map

    local format = ttUSHORT(data, index_map + 0)
    if format == 0 then -- apple byte encoding
        local bytes = ttUSHORT(data, index_map + 2)
        if unicode_codepoint < bytes - 6 then
            return ttBYTE(data, index_map + 6 + unicode_codepoint)
        end
        return 0
    elseif format == 6 then
        local first = ttUSHORT(data, index_map + 6)
        local count = ttUSHORT(data, index_map + 8)
        if unicode_codepoint >= first and unicode_codepoint < first + count then
            return ttUSHORT(data, index_map + 10 + (unicode_codepoint - first) * 2)
        end
        return 0
    elseif format == 2 then
        STBTT_assert(false) -- @TODO: high-byte mapping for japanese/chinese/korean
        return 0
    elseif format == 4 then -- standard mapping for windows fonts: binary search collection of ranges
        local segcount = bit32.rshift(ttUSHORT(data, index_map + 6), 1)
        local searchRange = bit32.rshift(ttUSHORT(data, index_map + 8), 1)
        local entrySelector = ttUSHORT(data, index_map + 10)
        local rangeShift = bit32.rshift(ttUSHORT(data, index_map + 12), 1)

        -- do a binary search of the segments
        local endCount = index_map + 14
        local search = endCount

        if unicode_codepoint > 0xffff then
            return 0
        end

        -- they lie from endCount .. endCount + segCount
        -- but searchRange is the nearest power of two, so...
        if unicode_codepoint >= ttUSHORT(data, search + rangeShift * 2) then
            search = search + rangeShift * 2
        end

        -- now decrement to bias correctly to find smallest
        search = search - 2
        while entrySelector ~= 0 do
            searchRange = bit32.rshift(searchRange, 1)
            local _end = ttUSHORT(data, search + searchRange * 2)
            if unicode_codepoint > _end then
                search = search + searchRange * 2
            end
            entrySelector = entrySelector - 1
        end
        search = search + 2

        do
            local item = stbtt_uint16(bit32.rshift(search - endCount, 1))

            local start = ttUSHORT(data, index_map + 14 + segcount * 2 + 2 + 2 * item)
            local last = ttUSHORT(data, endCount + 2 * item)
            if unicode_codepoint < start or unicode_codepoint > last then
                return 0
            end

            local offset = ttUSHORT(data, index_map + 14 + segcount * 6 + 2 + 2 * item)
            if offset == 0 then
                return stbtt_uint16(unicode_codepoint + ttSHORT(data, index_map + 14 + segcount * 4 + 2 + 2 * item))
            end

            return ttUSHORT(data, offset + (unicode_codepoint - start) * 2 + index_map + 14 + segcount * 6 + 2 + 2 * item)
        end
    elseif format == 12 or format == 13 then
        local ngroups = ttULONG(data, index_map + 12)
        local low = 0
        local high = ngroups
        -- Binary search the right group.
        while low < high do
            local mid = low + bit32.rshift(high - low, 1) -- rounds down, so low <= mid < high
            local start_char = ttULONG(data, index_map + 16 + mid * 12)
            local end_char = ttULONG(data, index_map + 16 + mid * 12 + 4)
            if unicode_codepoint < start_char then
                high = mid
            elseif unicode_codepoint > end_char then
                low = mid + 1
            else
                local start_glyph = ttULONG(data, index_map + 16 + mid * 12 + 8)
                if format == 12 then
                    return start_glyph + unicode_codepoint - start_char
                else -- format == 13
                    return start_glyph
                end
            end
        end
        return 0 -- not found
    end

    -- @TODO
    STBTT_assert(false)
    return 0
end

--- @param v        stbtt_vertex
--- @param vtx_type STBTT_VTX
--- @param x        stbtt_int32
--- @param y        stbtt_int32
--- @param cx       stbtt_int32
--- @param cy       stbtt_int32
local function stbtt_setvertex(v, vtx_type, x, y, cx, cy)
    v.type = vtx_type
    v.x = (stbtt_int16)(x)
    v.y = (stbtt_int16)(y)
    v.cx = (stbtt_int16)(cx)
    v.cy = (stbtt_int16)(cy)
end

local function stbtt__GetGlyfOffset(info, glyph_index)
    STBTT_assert(info.cff.size == 0)

    if glyph_index >= info.numGlyphs then return -1 end -- glyph index out of range
    if info.indexToLocFormat >= 2 then return -1 end -- unknown index->glyph map format

    local g1, g2
    if info.indexToLocFormat == 0 then
        g1 = info.glyf + ttUSHORT(info.data, info.loca + glyph_index * 2) * 2
        g2 = info.glyf + ttUSHORT(info.data, info.loca + glyph_index * 2 + 2) * 2
    else
        g1 = info.glyf + ttULONG(info.data, info.loca + glyph_index * 4)
        g2 = info.glyf + ttULONG(info.data, info.loca + glyph_index * 4 + 4)
    end

    if g1 == g2 then return -1 else return g1 end -- if length is 0, return -1
end

-- Gets the bounding box of the visible part of the glyph, in unscaled coordinates
--- @return integer, integer?, integer?, integer?, integer?
local function stbtt_GetGlyphBox(info, glyph_index)
    local n, x0, y0, x1, y1

    if info.cff.size ~= 0 then
        n, x0, y0, x1, y1 = stbtt__GetGlyphInfoT2(info, glyph_index)
    else
        local g = stbtt__GetGlyfOffset(info, glyph_index)
        if g < 0 then return 0 end

        x0 = ttSHORT(info.data, g + 2)
        y0 = ttSHORT(info.data, g + 4)
        x1 = ttSHORT(info.data, g + 6)
        y1 = ttSHORT(info.data, g + 8)
    end

    return 1, x0, y0, x1, y1
end

--- @param vertices     stbtt_vertex[]
--- @param num_vertices int
--- @param was_off      bool
--- @param start_off    bool
--- @param sx           stbtt_int32
--- @param sy           stbtt_int32
--- @param scx          stbtt_int32
--- @param scy          stbtt_int32
--- @param cx           stbtt_int32
--- @param cy           stbtt_int32
local function stbtt__close_shape(vertices, num_vertices, was_off, start_off, sx, sy, scx, scy, cx, cy)
    if start_off then
        if was_off then
            stbtt_setvertex(vertices[num_vertices + 1], STBTT_VTX.CURVE, bit32.rshift(cx + scx, 1), bit32.rshift(cy + scy, 1), cx, cy)
            num_vertices = num_vertices + 1
        end
        stbtt_setvertex(vertices[num_vertices + 1], STBTT_VTX.CURVE, sx, sy, scx, scy)
        num_vertices = num_vertices + 1
    else
        if was_off then
            stbtt_setvertex(vertices[num_vertices + 1], STBTT_VTX.CURVE, sx, sy, cx, cy)
            num_vertices = num_vertices + 1
        else
            stbtt_setvertex(vertices[num_vertices + 1], STBTT_VTX.LINE, sx, sy, 0, 0)
            num_vertices = num_vertices + 1
        end
    end
    return num_vertices
end

--- @param info        stbtt_fontinfo
--- @param glyph_index int
--- @return int             num_vertices
--- @return stbtt_vertex[]? vertices
local function stbtt__GetGlyphShapeTT(info, glyph_index)
    local data = info.data
    local num_vertices

    local vertices = nil

    local g = stbtt__GetGlyfOffset(info, glyph_index)

    if g < 0 then return 0 end

    local numberOfContours = ttSHORT(data, g)

    if numberOfContours > 0 then
        local endPtsOfContours = g + 10
        local ins = ttUSHORT(data, endPtsOfContours + numberOfContours * 2)
        local points = (endPtsOfContours + numberOfContours * 2 + 2 + ins) + 1 -- 1-based idx

        local n = 1 + ttUSHORT(data, endPtsOfContours + numberOfContours * 2 - 2)
        local m = n + 2 * numberOfContours -- a loose bound on how many vertices we might need

        vertices = {}
        for i = 1, m do vertices[i] = stbtt_vertex() end

        local j = 0
        local was_off = false
        local start_off = false
        local next_move = 0
        local flagcount = 0

        -- in first pass, we load uninterpreted data into the allocated array
        -- above, shifted to the end of the array so we won't overwrite it when
        -- we create our final data starting from the front

        local off = m - n -- starting offset for uninterpreted data, regardless of how m ends up being calculated

        -- first load flags
        local flags = 0
        for i = 1, n do
            if flagcount == 0 then
                flags = data[points]
                points = points + 1

                if bit32.band(flags, 8) ~= 0 then
                    flagcount = data[points]
                    points = points + 1
                end
            else
                flagcount = flagcount - 1
            end

            vertices[off + i].type = flags
        end

        -- now load x coordinates
        local x = 0
        for i = 1, n do
            flags = vertices[off + i].type
            if bit32.band(flags, 2) ~= 0 then
                local dx = data[points]
                points = points + 1
                if bit32.band(flags, 16) ~= 0 then -- ???
                    x = x + dx
                else
                    x = x - dx
                end
            else
                if bit32.band(flags, 16) == 0 then
                    x = x + stbtt_int16(data[points] * 256 + data[points + 1])
                    points = points + 2
                end
            end

            vertices[off + i].x = stbtt_int16(x)
        end

        -- now load y coordinates
        local y = 0
        for i = 1, n do
            flags = vertices[off + i].type
            if bit32.band(flags, 4) ~= 0 then
                local dy = data[points]
                points = points + 1
                if bit32.band(flags, 32) ~= 0 then -- ???
                    y = y + dy
                else
                    y = y - dy
                end
            else
                if bit32.band(flags, 32) == 0 then
                    y = y + stbtt_int16(data[points] * 256 + data[points + 1])
                    points = points + 2
                end
            end

            vertices[off + i].y = stbtt_int16(y)
        end

        -- now convert them to our format
        num_vertices = 0
        local sx, sy, cx, cy, scx, scy = 0, 0, 0, 0, 0, 0
        for i = 1, n do
            flags = vertices[off + i].type
            x = stbtt_int16(vertices[off + i].x)
            y = stbtt_int16(vertices[off + i].y)

            if next_move == i - 1 then
                if i ~= 1 then
                    num_vertices = stbtt__close_shape(vertices, num_vertices, was_off, start_off, sx, sy, scx, scy, cx, cy)
                end

                -- now start the new one
                start_off = (bit32.band(flags, 1) == 0)
                if start_off then
                    -- if we start off with an off-curve point, then when we need to find a point on the curve
                    -- where we can start, and we need to save some state for when we wraparound.
                    scx = x
                    scy = y
                    if bit32.band(vertices[off + i + 1].type, 1) == 0 then
                        -- next point is also a curve point, so interpolate an on-point curve
                        sx = bit32.rshift(x + stbtt_int32(vertices[off + i + 1].x), 1)
                        sy = bit32.rshift(y + stbtt_int32(vertices[off + i + 1].y), 1)
                    else
                        -- otherwise just use the next point as our start point
                        sx = stbtt_int32(vertices[off + i + 1].x)
                        sy = stbtt_int32(vertices[off + i + 1].y)
                        i = i + 1 -- we're using point i+1 as the starting point, so skip it
                    end
                else
                    sx = x
                    sy = y
                end
                stbtt_setvertex(vertices[num_vertices + 1], STBTT_VTX.MOVE, sx, sy, 0, 0)
                num_vertices = num_vertices + 1
                was_off = false
                next_move = 1 + ttUSHORT(data, endPtsOfContours + j * 2)
                j = j + 1
            else
                if bit32.band(flags, 1) == 0 then -- if it's a curve
                    if was_off then -- two off-curve control points in a row means interpolate an on-curve midpoint
                        stbtt_setvertex(vertices[num_vertices + 1], STBTT_VTX.CURVE, bit32.rshift(cx + x, 1), bit32.rshift(cy + y, 1), cx, cy)
                        num_vertices = num_vertices + 1
                    end

                    cx = x
                    cy = y
                    was_off = true
                else
                    if was_off then
                        stbtt_setvertex(vertices[num_vertices + 1], STBTT_VTX.CURVE, x, y, cx, cy)
                        num_vertices = num_vertices + 1
                    else
                        stbtt_setvertex(vertices[num_vertices + 1], STBTT_VTX.LINE, x, y, 0, 0)
                        num_vertices = num_vertices + 1
                    end

                    was_off = false
                end
            end
        end

        num_vertices = stbtt__close_shape(vertices, num_vertices, was_off, start_off, sx, sy, scx, scy, cx, cy)
    elseif numberOfContours < 0 then
        -- Compound shapes.
        local more = 1
        local comp = g + 10
        num_vertices = 0

        while more ~= 0 do
            local flags, gidx
            local comp_num_vertices = 0
            local comp_verts

            local mtx = {1, 0, 0, 1, 0, 0}
            local m, n

            flags = ttSHORT(data, comp) comp = comp + 2
            gidx = ttSHORT(data, comp) comp = comp + 2

            if bit32.band(flags, 2) ~= 0 then -- XY values
                if bit32.band(flags, 1) ~= 0 then -- shorts
                    mtx[5] = ttSHORT(data, comp) comp = comp + 2
                    mtx[6] = ttSHORT(data, comp) comp = comp + 2
                else
                    mtx[5] = ttCHAR(data, comp) comp = comp + 1
                    mtx[6] = ttCHAR(data, comp) comp = comp + 1
                end
            else
                -- @TODO handle matching point
                STBTT_assert(false)
            end

            if bit32.band(flags, bit32.lshift(1, 3)) ~= 0 then -- WE_HAVE_A_SCALE
                mtx[4] = ttSHORT(data, comp) / 16384.0
                mtx[1] = mtx[4]
                comp = comp + 2

                mtx[3] = 0
                mtx[2] = mtx[3]
            elseif bit32.band(flags, bit32.lshift(1, 6)) ~= 0 then -- WE_HAVE_AN_X_AND_YSCALE
                mtx[1] = ttSHORT(data, comp) / 16384.0
                comp = comp + 2

                mtx[3] = 0
                mtx[2] = mtx[3]

                mtx[4] = ttSHORT(data, comp) / 16384.0
                comp = comp + 2
            elseif bit32.band(flags, bit32.lshift(1, 7)) ~= 0 then -- WE_HAVE_A_TWO_BY_TWO
                mtx[1] = ttSHORT(data, comp) / 16384.0 comp = comp + 2
                mtx[2] = ttSHORT(data, comp) / 16384.0 comp = comp + 2
                mtx[3] = ttSHORT(data, comp) / 16384.0 comp = comp + 2
                mtx[4] = ttSHORT(data, comp) / 16384.0 comp = comp + 2
            end

            -- Find transformation scales.
            m = STBTT_sqrt(mtx[1] * mtx[1] + mtx[2] * mtx[2])
            n = STBTT_sqrt(mtx[3] * mtx[3] + mtx[4] * mtx[4])

            -- Get indexed glyph.
            comp_num_vertices, comp_verts = stbtt_GetGlyphShape(info, gidx)
            if comp_num_vertices > 0 then
                -- Transform vertices.
                for i = 1, comp_num_vertices do
                    local v = comp_verts[i]
                    local x = v.x
                    local y = v.y
                    v.x = stbtt_int16(m * (mtx[1] * x + mtx[3] * y + mtx[5]))
                    v.y = stbtt_int16(n * (mtx[2] * x + mtx[4] * y + mtx[6]))
                    x = v.cx
                    y = v.cy
                    v.cx = stbtt_int16(m * (mtx[1] * x + mtx[3] * y + mtx[5]))
                    v.cy = stbtt_int16(n * (mtx[2] * x + mtx[4] * y + mtx[6]))
                end

                -- Append vertices.
                if num_vertices == 0 then -- LUA: No malloc
                    vertices = comp_verts
                else
                    for i = 1, comp_num_vertices do
                        vertices[num_vertices + i] = comp_verts[i]
                    end
                end

                num_vertices = num_vertices + comp_num_vertices
            end

            -- More components ?
            more = bit32.band(flags, bit32.lshift(1, 5))
        end
    end

    return num_vertices, vertices
end

--- @param c stbtt__csctx
--- @param x stbtt_int32
--- @param y stbtt_int32
local function stbtt__track_vertex(c, x, y)
    if x > c.max_x or not c.started then c.max_x = x end
    if y > c.max_y or not c.started then c.max_y = y end
    if x < c.min_x or not c.started then c.min_x = x end
    if y < c.min_y or not c.started then c.min_y = y end
    c.started = true
end

--- @param c        stbtt__csctx
--- @param vtx_type STBTT_VTX
--- @param x        stbtt_int32
--- @param y        stbtt_int32
--- @param cx       stbtt_int32
--- @param cy       stbtt_int32
--- @param cx1      stbtt_int32
--- @param cy1      stbtt_int32
local function stbtt__csctx_v(c, vtx_type, x, y, cx, cy, cx1, cy1)
    if c.bounds then
        stbtt__track_vertex(c, x, y)
        if vtx_type == STBTT_VTX.CUBIC then
            stbtt__track_vertex(c, cx, cy)
            stbtt__track_vertex(c, cx1, cy1)
        end
    else
        stbtt_setvertex(c.pvertices[c.num_vertices + 1], vtx_type, x, y, cx, cy)
        c.pvertices[c.num_vertices + 1].cx1 = stbtt_int16(cx1)
        c.pvertices[c.num_vertices + 1].cy1 = stbtt_int16(cy1)
    end
end

--- @param ctx stbtt__csctx
local function stbtt__csctx_close_shape(ctx)
    if ctx.first_x ~= ctx.x or ctx.first_y ~= ctx.y then
        stbtt__csctx_v(ctx, STBTT_VTX.LINE, trunc(ctx.first_x), trunc(ctx.first_y), 0, 0, 0, 0)
    end
end

--- @param ctx stbtt__csctx
--- @param dx  float
--- @param dy  float
local function stbtt__csctx_rmove_to(ctx, dx, dy)
    stbtt__csctx_close_shape(ctx)
    ctx.x = ctx.x + dx
    ctx.first_x = ctx.x
    ctx.y = ctx.y + dy
    ctx.first_y = ctx.y
    stbtt__csctx_v(ctx, STBTT_VTX.MOVE, trunc(ctx.x), trunc(ctx.y), 0, 0, 0, 0)
end

--- @param ctx stbtt__csctx
--- @param dx  float
--- @param dy  float
local function stbtt__csctx_rline_to(ctx, dx, dy)
    ctx.x = ctx.x + dx
    ctx.y = ctx.y + dy
    stbtt__csctx_v(ctx, STBTT_VTX.LINE, trunc(ctx.x), trunc(ctx.y), 0, 0, 0, 0)
end

--- @param ctx stbtt__csctx
--- @param dx1 float
--- @param dy1 float
--- @param dx2 float
--- @param dy2 float
--- @param dx3 float
--- @param dy3 float
local function stbtt__csctx_rccurve_to(ctx, dx1, dy1, dx2, dy2, dx3, dy3)
    local cx1 = ctx.x + dx1
    local cy1 = ctx.y + dy1
    local cx2 = cx1 + dx2
    local cy2 = cy1 + dy2
    ctx.x = cx2 + dx3
    ctx.y = cy2 + dy3
    stbtt__csctx_v(ctx, STBTT_VTX.CUBIC, trunc(ctx.x), trunc(ctx.y), trunc(cx1), trunc(cy1), trunc(cx2), trunc(cy2))
end

local function stbtt__get_subr(idx, n)
    local count = stbtt__cff_index_count(idx)
    local bias = 107
    if count >= 33900 then
        bias = 32768
    elseif count >= 1240 then
        bias = 1131
    end
    n = n + bias
    if n < 0 or n >= count then
        return stbtt__new_buf(nil, 0)
    end
    return stbtt__cff_index_get(idx, n)
end

local function stbtt__cid_get_glyph_subrs(info, glyph_index)
    local fdselect = info.fdselect
    local fdselector = -1

    stbtt__buf_seek(fdselect, 0)
    local fmt = stbtt__buf_get8(fdselect)
    if fmt == 0 then
        -- untested
        stbtt__buf_skip(fdselect, glyph_index)
        fdselector = stbtt__buf_get8(fdselect)
    elseif fmt == 3 then
        local nranges = stbtt__buf_get16(fdselect)
        local start = stbtt__buf_get16(fdselect)
        for i = 0, nranges - 1 do
            local v = stbtt__buf_get8(fdselect)
            local _end = stbtt__buf_get16(fdselect)
            if glyph_index >= start and glyph_index < _end then
                fdselector = v
                break
            end
            start = _end
        end
    end
    if fdselector == -1 then return stbtt__new_buf(nil, 0) end -- [DEAR IMGUI] fixed, see #6007 and nothings/stb#1422
    return stbtt__get_subrs(info.cff, stbtt__cff_index_get(info.fontdicts, fdselector))
end

--- @param info        stbtt_fontinfo
--- @param glyph_index int
--- @param c           stbtt__csctx
local function stbtt__run_charstring(info, glyph_index, c)
    local in_header = true
    local maskbits = 0
    local subr_stack_height = 0
    local sp = 0
    local has_subrs = 0
    local clear_stack

    local s = {} -- size = 48, 0-based

    local subr_stack = {} for i = 1, 10 do subr_stack[i] = stbtt__buf() end

    local subrs = info.subrs
    local b, f

    local function STBTT__CSERR(_s) return 0 end

    -- this currently ignores the initial width value, which isn't needed if we have hmtx
    b = stbtt__cff_index_get(info.charstrings, glyph_index)
    local i, v, b0
    while b.cursor < b.size do
        i = 0
        clear_stack = 1
        b0 = stbtt__buf_get8(b)

        -- @TODO implement hinting
        if b0 == 0x13 or b0 == 0x14 then -- hintmask or cntrmask
            if in_header then
                maskbits = maskbits + trunc(sp / 2)  -- implicit "vstem"
            end
            in_header = false
            stbtt__buf_skip(b, trunc((maskbits + 7) / 8))
        elseif b0 == 0x01 or b0 == 0x03 or b0 == 0x12 or b0 == 0x17 then -- hstem, vstem, hstemhm, vstemhm
            maskbits = maskbits + trunc(sp / 2)
        elseif b0 == 0x15 then -- rmoveto
            in_header = false
            if sp < 2 then return STBTT__CSERR("rmoveto stack") end
            stbtt__csctx_rmove_to(c, s[sp - 2], s[sp - 1])
        elseif b0 == 0x04 then -- vmoveto
            in_header = false
            if sp < 1 then return STBTT__CSERR("vmoveto stack") end
            stbtt__csctx_rmove_to(c, 0, s[sp - 1])
        elseif b0 == 0x16 then -- hmoveto
            in_header = false
            if sp < 1 then return STBTT__CSERR("hmoveto stack") end
            stbtt__csctx_rmove_to(c, s[sp - 1], 0)
        elseif b0 == 0x05 then -- rlineto
            if sp < 2 then return STBTT__CSERR("rlineto stack") end
            while i + 1 < sp do
                stbtt__csctx_rline_to(c, s[i], s[i + 1])
                i = i + 2
            end

        -- hlineto/vlineto and vhcurveto/hvcurveto alternate horizontal and vertical
        -- starting from a different place.

        elseif b0 == 0x07 then -- vlineto
            if sp < 1 then return STBTT__CSERR("vlineto stack") end
            while true do
                if i >= sp then break end
                stbtt__csctx_rline_to(c, 0, s[i])
                i = i + 1
                if i >= sp then break end
                stbtt__csctx_rline_to(c, s[i], 0)
                i = i + 1
            end
        elseif b0 == 0x06 then -- hlineto
            if sp < 1 then return STBTT__CSERR("hlineto stack") end

            while true do
                if i >= sp then break end
                stbtt__csctx_rline_to(c, s[i], 0)
                i = i + 1
            -- vlineto
                if i >= sp then break end
                stbtt__csctx_rline_to(c, 0, s[i])
                i = i + 1
            end
        elseif b0 == 0x1F then -- hvcurveto
            if sp < 4 then return STBTT__CSERR("hvcurveto stack") end
            while true do
                if i + 3 >= sp then break end
                stbtt__csctx_rccurve_to(c, s[i], 0, s[i + 1], s[i + 2], ((sp - i) == 5) and s[i + 4] or 0.0, s[i + 3])
                i = i + 4
                if i + 3 >= sp then break end
                stbtt__csctx_rccurve_to(c, 0, s[i], s[i + 1], s[i + 2], s[i + 3], ((sp - i) == 5) and s[i + 4] or 0.0)
                i = i + 4
            end
        elseif b0 == 0x1E then -- vhcurveto
            if sp < 4 then return STBTT__CSERR("vhcurveto stack") end

            while true do
                if i + 3 >= sp then break end
                stbtt__csctx_rccurve_to(c, 0, s[i], s[i + 1], s[i + 2], s[i + 3], ((sp - i) == 5) and s[i + 4] or 0.0)
                i = i + 4
            -- hvcurveto
                if i + 3 >= sp then break end
                stbtt__csctx_rccurve_to(c, s[i], 0, s[i + 1], s[i + 2], ((sp - i) == 5) and s[i + 4] or 0.0, s[i + 3])
                i = i + 4
            end
        elseif b0 == 0x08 then -- rrcurveto
            if sp < 6 then return STBTT__CSERR("rcurveline stack") end

            while i + 5 < sp do
                stbtt__csctx_rccurve_to(c, s[i], s[i + 1], s[i + 2], s[i + 3], s[i + 4], s[i + 5])
                i = i + 6
            end
        elseif b0 == 0x18 then -- rcurveline
            if sp < 8 then return STBTT__CSERR("rcurveline stack") end

            while i + 5 < sp - 2 do
                stbtt__csctx_rccurve_to(c, s[i], s[i + 1], s[i + 2], s[i + 3], s[i + 4], s[i + 5])
                i = i + 6
            end
            if i + 1 >= sp then return STBTT__CSERR("rcurveline stack") end
            stbtt__csctx_rline_to(c, s[i], s[i + 1])
        elseif b0 == 0x19 then -- rlinecurve
            if sp < 8 then return STBTT__CSERR("rlinecurve stack") end

            while i + 1 < sp - 6 do
                stbtt__csctx_rline_to(c, s[i], s[i + 1])
                i = i + 2
            end
            if i + 5 >= sp then return STBTT__CSERR("rlinecurve stack") end
            stbtt__csctx_rccurve_to(c, s[i], s[i + 1], s[i + 2], s[i + 3], s[i + 4], s[i + 5])
        elseif b0 == 0x1A or b0 == 0x1B then -- vvcurveto or hhcurveto
            if sp < 4 then return STBTT__CSERR("(vv|hh)curveto stack") end
            f = 0.0

            if bit32.band(sp, 1) ~= 0 then
                f = s[i]
                i = i + 1
            end
            while i + 3 < sp do
                if b0 == 0x1B then
                    stbtt__csctx_rccurve_to(c, s[i], f, s[i + 1], s[i + 2], s[i + 3], 0.0)
                else
                    stbtt__csctx_rccurve_to(c, f, s[i], s[i + 1], s[i + 2], 0.0, s[i + 3])
                end
                f = 0.0
                i = i + 4
            end
        elseif b0 == 0x0A -- callsubr
            or b0 == 0x1D then

            if b0 == 0x0A and has_subrs == 0 then
                if info.fdselect.size ~= 0 then
                    subrs = stbtt__cid_get_glyph_subrs(info, glyph_index)
                end
                has_subrs = 1
            end

            -- callgsubr
            if sp < 1 then return STBTT__CSERR("call(g|)subr stack") end
            sp = sp - 1
            v = trunc(s[sp])
            if subr_stack_height >= 10 then return STBTT__CSERR("recursion limit") end
            subr_stack[subr_stack_height + 1] = b
            subr_stack_height = subr_stack_height + 1
            b = stbtt__get_subr((b0 == 0x0A) and subrs or info.gsubrs, v)
            if b.size == 0 then return STBTT__CSERR("subr not found") end
            b.cursor = 0
            clear_stack = 0
        elseif b0 == 0x0B then -- return
            if subr_stack_height <= 0 then return STBTT__CSERR("return outside subr") end
            subr_stack_height = subr_stack_height - 1
            b = subr_stack[subr_stack_height + 1]
            clear_stack = 0
        elseif b0 == 0x0E then -- endchar
            stbtt__csctx_close_shape(c)
            return 1
        elseif b0 == 0x0C then -- two-byte escape
            local b1 = stbtt__buf_get8(b)

            -- @TODO These "flex" implementations ignore the flex-depth and resolution,
            -- and always draw beziers.
            if b1 == 0x22 then -- hflex
                if sp < 7 then return STBTT__CSERR("hflex stack") end
                local dx1 = s[0]
                local dx2 = s[1]
                local dy2 = s[2]
                local dx3 = s[3]
                local dx4 = s[4]
                local dx5 = s[5]
                local dx6 = s[6]
                stbtt__csctx_rccurve_to(c, dx1, 0, dx2, dy2, dx3, 0)
                stbtt__csctx_rccurve_to(c, dx4, 0, dx5, -dy2, dx6, 0)
            elseif b1 == 0x23 then -- flex
                if sp < 13 then return STBTT__CSERR("flex stack") end
                local dx1 = s[0]
                local dy1 = s[1]
                local dx2 = s[2]
                local dy2 = s[3]
                local dx3 = s[4]
                local dy3 = s[5]
                local dx4 = s[6]
                local dy4 = s[7]
                local dx5 = s[8]
                local dy5 = s[9]
                local dx6 = s[10]
                local dy6 = s[11]
                -- fd is s[12]
                stbtt__csctx_rccurve_to(c, dx1, dy1, dx2, dy2, dx3, dy3)
                stbtt__csctx_rccurve_to(c, dx4, dy4, dx5, dy5, dx6, dy6)
            elseif b1 == 0x24 then -- hflex1
                if sp < 9 then return STBTT__CSERR("hflex1 stack") end
                local dx1 = s[0]
                local dy1 = s[1]
                local dx2 = s[2]
                local dy2 = s[3]
                local dx3 = s[4]
                local dx4 = s[5]
                local dx5 = s[6]
                local dy5 = s[7]
                local dx6 = s[8]
                stbtt__csctx_rccurve_to(c, dx1, dy1, dx2, dy2, dx3, 0)
                stbtt__csctx_rccurve_to(c, dx4, 0, dx5, dy5, dx6, -(dy1 + dy2 + dy5))
            elseif b1 == 0x25 then -- flex1
                if sp < 11 then return STBTT__CSERR("flex1 stack") end
                local dx1 = s[0]
                local dy1 = s[1]
                local dx2 = s[2]
                local dy2 = s[3]
                local dx3 = s[4]
                local dy3 = s[5]
                local dx4 = s[6]
                local dy4 = s[7]
                local dx5 = s[8]
                local dy5 = s[9]
                local dx6 = s[10]
                local dy6 = s[10]
                local dx = dx1 + dx2 + dx3 + dx4 + dx5
                local dy = dy1 + dy2 + dy3 + dy4 + dy5
                if STBTT_fabs(dx) > STBTT_fabs(dy) then
                    dy6 = -dy
                else
                    dx6 = -dx
                end
                stbtt__csctx_rccurve_to(c, dx1, dy1, dx2, dy2, dx3, dy3)
                stbtt__csctx_rccurve_to(c, dx4, dy4, dx5, dy5, dx6, dy6)
            else
                return STBTT__CSERR("unimplemented")
            end
        else
            if b0 ~= 255 and b0 ~= 28 and b0 < 32 then
                return STBTT__CSERR("reserved operator")
            end

            -- push immediate
            if b0 == 255 then
                f = stbtt__buf_get32(b) / 0x10000
            else
                stbtt__buf_skip(b, -1)
                f = stbtt_int16(stbtt__cff_int(b))
            end
            if sp >= 48 then return STBTT__CSERR("push stack overflow") end
            s[sp] = f
            sp = sp + 1
            clear_stack = 0
        end

        if clear_stack ~= 0 then
            sp = 0
        end
    end

    return STBTT__CSERR("no endchar")
end

--- @param info        stbtt_fontinfo
--- @param glyph_index int
--- @return int             num_vertices
--- @return stbtt_vertex[]? vertices
function stbtt__GetGlyphShapeT2(info, glyph_index)
    -- runs the charstring twice, once to count and once to output (to avoid realloc)
    local vertices = nil
    local count_ctx = STBTT__CSCTX_INIT(true)
    local output_ctx = STBTT__CSCTX_INIT(false)
    if stbtt__run_charstring(info, glyph_index, count_ctx) ~= 0 then
        vertices = {} for i = 1, count_ctx.num_vertices do vertices[i] = stbtt_vertex() end

        output_ctx.pvertices = vertices
        if stbtt__run_charstring(info, glyph_index, output_ctx) ~= 0 then
            STBTT_assert(output_ctx.num_vertices == count_ctx.num_vertices)
            return output_ctx.num_vertices, vertices
        end
    end

    return 0, vertices
end

--- @param info        stbtt_fontinfo
--- @param glyph_index int
--- @return int
--- @return int x0
--- @return int y0
--- @return int x1
--- @return int y1
function stbtt__GetGlyphInfoT2(info, glyph_index)
    local c = STBTT__CSCTX_INIT(true)
    local r = stbtt__run_charstring(info, glyph_index, c)
    local x0 = (r ~= 0) and c.min_x or 0
    local y0 = (r ~= 0) and c.min_y or 0
    local x1 = (r ~= 0) and c.max_x or 0
    local y1 = (r ~= 0) and c.max_y or 0
    return ((r ~= 0) and c.num_vertices or 0), x0, y0, x1, y1
end

-- returns # of vertices and fills *vertices with the pointer to them
--   these are expressed in "unscaled" coordinates
--
-- The shape is a series of contours. Each one starts with
-- a STBTT_moveto, then consists of a series of mixed
-- STBTT_lineto and STBTT_curveto segments. A lineto
-- draws a line from previous endpoint to its x,y; a curveto
-- draws a quadratic bezier from previous endpoint to
-- its x,y, using cx,cy as the bezier control point.
--- @param info        stbtt_fontinfo
--- @param glyph_index int
function stbtt_GetGlyphShape(info, glyph_index)
    if info.cff.size == 0 then
        return stbtt__GetGlyphShapeTT(info, glyph_index)
    else
        return stbtt__GetGlyphShapeT2(info, glyph_index)
    end
end

-- leftSideBearing is the offset from the current horizontal position to the left edge of the character
-- advanceWidth is the offset from the current horizontal position to the next horizontal position
--   these are expressed in unscaled coordinates
--- @param info        stbtt_fontinfo
--- @param glyph_index int
function stbtt_GetGlyphHMetrics(info, glyph_index)
    local numOfLongHorMetrics = ttUSHORT(info.data, info.hhea + 34)

    local advanceWidth, leftSideBearing
    if glyph_index < numOfLongHorMetrics then
        advanceWidth = ttSHORT(info.data, info.hmtx + 4 * glyph_index)
        leftSideBearing = ttSHORT(info.data, info.hmtx + 4 * glyph_index + 2)
    else
        advanceWidth = ttSHORT(info.data, info.hmtx + 4 * (numOfLongHorMetrics - 1))
        leftSideBearing = ttSHORT(info.data, info.hmtx + 4 * numOfLongHorMetrics + 2 * (glyph_index - numOfLongHorMetrics))
    end

    return advanceWidth, leftSideBearing
end

-- ascent is the coordinate above the baseline the font extends; descent
-- is the coordinate below the baseline the font extends (i.e. it is typically negative)
-- lineGap is the spacing between one row's descent and the next row's ascent...
-- so you should advance the vertical position by "ascent - descent + lineGap"
--   these are expressed in unscaled coordinates, so you must multiply by
--   the scale factor for a given size
--- @param info stbtt_fontinfo
function stbtt_GetFontVMetrics(info)
    local ascent = ttSHORT(info.data, info.hhea + 4)
    local descent = ttSHORT(info.data, info.hhea + 6)
    local lineGap = ttSHORT(info.data, info.hhea + 8)

    return ascent, descent, lineGap
end

-- computes a scale factor to produce a font whose "height" is 'pixels' tall.
-- Height is measured as the distance from the highest ascender to the lowest
-- descender; in other words, it's equivalent to calling stbtt_GetFontVMetrics
-- and computing:
--       scale = pixels / (ascent - descent)
-- so if you prefer to measure height by the ascent only, use a similar calculation.
--- @param info   stbtt_fontinfo
--- @param height float
function stbtt_ScaleForPixelHeight(info, height)
    local fheight = ttSHORT(info.data, info.hhea + 4) - ttSHORT(info.data, info.hhea + 6)
    return height / fheight
end

------------------------------------
------------------------------------
---
--- antialiasing software rasterizer
---
---

-- same as stbtt_GetGlyphBitmapBox, but you can specify a subpixel
-- shift for the character
--- @param font    stbtt_fontinfo
--- @param glyph   int
--- @param scale_x float
--- @param scale_y float
--- @param shift_x float
--- @param shift_y float
function stbtt_GetGlyphBitmapBoxSubpixel(font, glyph, scale_x, scale_y, shift_x, shift_y)
    local n, x0, y0, x1, y1 = stbtt_GetGlyphBox(font, glyph)

    local ix0, iy0, ix1, iy1
    if n == 0 then
        -- e.g. space character
        ix0 = 0
        iy0 = 0
        ix1 = 0
        iy1 = 0
    else
        -- move to integral bboxes (treating pixels as little squares, what pixels get touched)?
        ix0 = STBTT_ifloor( x0 * scale_x + shift_x)
        iy0 = STBTT_ifloor(-y1 * scale_y + shift_y)
        ix1 = STBTT_iceil( x1 * scale_x + shift_x)
        iy1 = STBTT_iceil(-y0 * scale_y + shift_y)
    end

    return ix0, iy0, ix1, iy1
end

-- get the bbox of the bitmap centered around the glyph origin; so the
-- bitmap width is ix1-ix0, height is iy1-iy0, and location to place
-- the bitmap top left is (leftSideBearing*scale,iy0).
-- (Note that the bitmap uses y-increases-down, but the shape uses
-- y-increases-up, so GlyphBitmapBox and GlyphBox are inverted.)
--- @param font    stbtt_fontinfo
--- @param glyph   int
--- @param scale_x float
--- @param scale_y float
function stbtt_GetGlyphBitmapBox(font, glyph, scale_x, scale_y)
    return stbtt_GetGlyphBitmapBoxSubpixel(font, glyph, scale_x, scale_y, 0.0, 0.0)
end

--------------
--------------
---
--- Rasterizer
---
---

--- UNIMPLEMENTED / UNUSED:
---     stbtt_MakeCodepointBitmap
---     stbtt_MakeCodepointBitmapSubpixelPrefilter
---     stbtt_GetGlyphBitmap
---     stbtt_MakeGlyphBitmap
---     stbtt_GetGlyphBitmapSubpixel

-- the edge passed in here does not cross the vertical line at x or the vertical line at x+1
-- (i.e. it has already been clipped to those)
--- @param scanline float[]
--- @param x        int
--- @param e        stbtt__active_edge
--- @param x0       float
--- @param y0       float
--- @param x1       float
--- @param y1       float
local function stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x1, y1)
    if y0 == y1 then return end
    STBTT_assert(y0 < y1)
    STBTT_assert(e.sy <= e.ey)

    if y0 > e.ey then return end
    if y1 < e.sy then return end
    if y0 < e.sy then
        x0 = x0 + (x1 - x0) * (e.sy - y0) / (y1 - y0)
        y0 = e.sy
    end
    if y1 > e.ey then
        x1 = x1 + (x1 - x0) * (e.ey - y1) / (y1 - y0)
        y1 = e.ey
    end

    if x0 == x then
        STBTT_assert(x1 <= x + 1)
    elseif x0 == x + 1 then
        STBTT_assert(x1 >= x)
    elseif x0 <= x then
        STBTT_assert(x1 <= x)
    elseif x0 >= x + 1 then
        STBTT_assert(x1 >= x + 1)
    else
        STBTT_assert(x1 >= x and x1 <= x + 1)
    end

    if x0 <= x and x1 <= x then
        scanline[x] = scanline[x] + e.direction * (y1 - y0)
    elseif x0 >= x + 1 and x1 >= x + 1 then
        -- do nothing
    else
        STBTT_assert(x0 >= x and x0 <= x + 1 and x1 >= x and x1 <= x + 1)
        scanline[x] = scanline[x] + e.direction * (y1 - y0) * (1 - ((x0 - x) + (x1 - x)) / 2) -- coverage = 1 - average x position
    end
end

--- @param height       float
--- @param top_width    float
--- @param bottom_width float
local function stbtt__sized_trapezoid_area(height, top_width, bottom_width)
    STBTT_assert(top_width >= 0)
    STBTT_assert(bottom_width >= 0)
    return (top_width + bottom_width) / 2.0 * height
end

--- @param height float
--- @param tx0    float
--- @param tx1    float
--- @param bx0    float
--- @param bx1    float
local function stbtt__position_trapezoid_area(height, tx0, tx1, bx0, bx1)
    return stbtt__sized_trapezoid_area(height, tx1 - tx0, bx1 - bx0)
end

--- @param height float
--- @param width  float
local function stbtt__sized_triangle_area(height, width)
    return height * width / 2
end

--- @param scanline      float[]
--- @param scanline_fill float[]
--- @param len           int
--- @param e             stbtt__active_edge
--- @param y_top         float
local function stbtt__fill_active_edges_new(scanline, scanline_fill, len, e, y_top)
    local y_bottom = y_top + 1

    while e do
        -- brute force every pixel

        -- compute intersection points with top & bottom
        STBTT_assert(e.ey >= y_top)

        if e.fdx == 0 then
            local x0 = e.fx
            if x0 < len then
                if x0 >= 0 then
                    stbtt__handle_clipped_edge(scanline, trunc(x0), e, x0, y_top, x0, y_bottom)
                    stbtt__handle_clipped_edge(scanline_fill, trunc(x0) + 1, e, x0, y_top, x0, y_bottom)
                else
                    stbtt__handle_clipped_edge(scanline_fill, 0, e, x0, y_top, x0, y_bottom)
                end
            end
        else
            local x0 = e.fx
            local dx = e.fdx
            local xb = x0 + dx
            local x_top, x_bottom
            local sy0, sy1
            local dy = e.fdy
            STBTT_assert(e.sy <= y_bottom and e.ey >= y_top)

            -- compute endpoints of line segment clipped to this scanline (if the
            -- line segment starts on this scanline. x0 is the intersection of the
            -- line with y_top, but that may be off the line segment.
            if e.sy > y_top then
                x_top = x0 + dx * (e.sy - y_top)
                sy0 = e.sy
            else
                x_top = x0
                sy0 = y_top
            end
            if e.ey < y_bottom then
                x_bottom = x0 + dx * (e.ey - y_top)
                sy1 = e.ey
            else
                x_bottom = xb
                sy1 = y_bottom
            end

            if x_top >= 0 and x_bottom >= 0 and x_top < len and x_bottom < len then
                -- from here on, we don't have to range check x values
                if trunc(x_top) == trunc(x_bottom) then
                    local height
                    -- simple case, only spans one pixel
                    local x = trunc(x_top)
                    height = (sy1 - sy0) * e.direction
                    STBTT_assert(x >= 0 and x < len)
                    scanline[x] = scanline[x] + stbtt__position_trapezoid_area(height, x_top, x + 1.0, x_bottom, x + 1.0)
                    scanline_fill[x + 1] = scanline_fill[x + 1] + height -- everything right of this pixel is filled
                else
                    local x1, x2
                    local y_crossing, y_final, step, sign, area
                    -- covers 2+ pixels
                    if x_top > x_bottom then
                        -- flip scanline vertically; signed area is the same
                        sy0 = y_bottom - (sy0 - y_top)
                        sy1 = y_bottom - (sy1 - y_top)
                        local t
                        t = sy0; sy0 = sy1; sy1 = t
                        t = x_bottom; x_bottom = x_top; x_top = t
                        dx = -dx
                        dy = -dy
                        t = x0; x0 = xb; xb = t
                    end
                    STBTT_assert(dy >= 0)
                    STBTT_assert(dx >= 0)

                    x1 = trunc(x_top)
                    x2 = trunc(x_bottom)
                    -- compute intersection with y axis at x1+1
                    y_crossing = y_top + dy * (x1 + 1 - x0)

                    -- compute intersection with y axis at x2
                    y_final = y_top + dy * (x2 - x0)

                    --           x1    x_top                            x2    x_bottom
                    --     y_top  +------|-----+------------+------------+--------|---+------------+
                    --            |            |            |            |            |            |
                    --            |            |            |            |            |            |
                    --       sy0  |      Txxxxx|............|............|............|............|
                    -- y_crossing |            *xxxxx.......|............|............|............|
                    --            |            |     xxxxx..|............|............|............|
                    --            |            |     /-   xx*xxxx........|............|............|
                    --            |            | dy <       |    xxxxxx..|............|............|
                    --   y_final  |            |     \-     |          xx*xxx.........|............|
                    --       sy1  |            |            |            |   xxxxxB...|............|
                    --            |            |            |            |            |            |
                    --            |            |            |            |            |            |
                    --  y_bottom  +------------+------------+------------+------------+------------+
                    --
                    -- goal is to measure the area covered by '.' in each pixel

                    -- if x2 is right at the right edge of x1, y_crossing can blow up, github #1057
                    -- @TODO: maybe test against sy1 rather than y_bottom?
                    if y_crossing > y_bottom then
                        y_crossing = y_bottom
                    end

                    sign = e.direction

                    -- area of the rectangle covered from sy0..y_crossing
                    area = sign * (y_crossing - sy0)

                    -- area of the triangle (x_top,sy0), (x1+1,sy0), (x1+1,y_crossing)
                    scanline[x1] = scanline[x1] + stbtt__sized_triangle_area(area, x1 + 1 - x_top)

                    -- check if final y_crossing is blown up; no test case for this
                    if y_final > y_bottom then
                        local denom = (x2 - (x1 + 1))
                        y_final = y_bottom
                        if denom ~= 0 then -- [DEAR IMGUI] Avoid div by zero (https://github.com/nothings/stb/issues/1316)
                            dy = (y_final - y_crossing) / denom -- if denom=0, y_final = y_crossing, so y_final <= y_bottom
                        end
                    end

                    -- in second pixel, area covered by line segment found in first pixel
                    -- is always a rectangle 1 wide * the height of that line segment; this
                    -- is exactly what the variable 'area' stores. it also gets a contribution
                    -- from the line segment within it. the THIRD pixel will get the first
                    -- pixel's rectangle contribution, the second pixel's rectangle contribution,
                    -- and its own contribution. the 'own contribution' is the same in every pixel except
                    -- the leftmost and rightmost, a trapezoid that slides down in each pixel.
                    -- the second pixel's contribution to the third pixel will be the
                    -- rectangle 1 wide times the height change in the second pixel, which is dy.

                    step = sign * dy * 1 -- dy is dy/dx, change in y for every 1 change in x,
                    -- which multiplied by 1-pixel-width is how much pixel area changes for each step in x
                    -- so the area advances by 'step' every time

                    for x = x1 + 1, x2 - 1 do
                        scanline[x] = scanline[x] + area + step / 2 -- area of trapezoid is 1*step/2
                        area = area + step
                    end
                    STBTT_assert(STBTT_fabs(area) <= 1.01) -- accumulated error from area += step unless we round step down
                    STBTT_assert(sy1 > y_final - 0.01)

                    -- area covered in the last pixel is the rectangle from all the pixels to the left,
                    -- plus the trapezoid filled by the line segment in this pixel all the way to the right edge
                    scanline[x2] = scanline[x2] + area + sign * stbtt__position_trapezoid_area(sy1 - y_final, x2, x2 + 1.0, x_bottom, x2 + 1.0)

                    -- the rest of the line is filled based on the total height of the line segment in this pixel
                    scanline_fill[x2 + 1] = scanline_fill[x2 + 1] + sign * (sy1 - sy0)
                end
            else
                -- if edge goes outside of box we're drawing, we require
                -- clipping logic. since this does not match the intended use
                -- of this library, we use a different, very slow brute
                -- force implementation
                -- note though that this does happen some of the time because
                -- x_top and x_bottom can be extrapolated at the top & bottom of
                -- the shape and actually lie outside the bounding box
                for x = 0, len - 1 do
                    -- cases:
                    --
                    -- there can be up to two intersections with the pixel. any intersection
                    -- with left or right edges can be handled by splitting into two (or three)
                    -- regions. intersections with top & bottom do not necessitate case-wise logic.
                    --
                    -- the old way of doing this found the intersections with the left & right edges,
                    -- then used some simple logic to produce up to three segments in sorted order
                    -- from top-to-bottom. however, this had a problem: if an x edge was epsilon
                    -- across the x border, then the corresponding y position might not be distinct
                    -- from the other y segment, and it might ignored as an empty segment. to avoid
                    -- that, we need to explicitly produce segments based on x positions.

                    -- rename variables to clearly-defined pairs
                    local y0 = y_top
                    local x1 = x
                    local x2 = x + 1
                    local x3 = xb
                    local y3 = y_bottom

                    -- x = e->x + e->dx * (y-y_top)
                    -- (y-y_top) = (x - e->x) / e->dx
                    -- y = (x - e->x) / e->dx + y_top
                    local y1 = (x - x0) / dx + y_top
                    local y2 = (x + 1 - x0) / dx + y_top

                    if x0 < x1 and x3 > x2 then -- three segments descending down-right
                        stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x1, y1)
                        stbtt__handle_clipped_edge(scanline, x, e, x1, y1, x2, y2)
                        stbtt__handle_clipped_edge(scanline, x, e, x2, y2, x3, y3)
                    elseif x3 < x1 and x0 > x2 then -- three segments descending down-left
                        stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x2, y2)
                        stbtt__handle_clipped_edge(scanline, x, e, x2, y2, x1, y1)
                        stbtt__handle_clipped_edge(scanline, x, e, x1, y1, x3, y3)
                    elseif x0 < x1 and x3 > x1 then -- two segments across x, down-right
                        stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x1, y1)
                        stbtt__handle_clipped_edge(scanline, x, e, x1, y1, x3, y3)
                    elseif x3 < x1 and x0 > x1 then -- two segments across x, down-left
                        stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x1, y1)
                        stbtt__handle_clipped_edge(scanline, x, e, x1, y1, x3, y3)
                    elseif x0 < x2 and x3 > x2 then -- two segments across x+1, down-right
                        stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x2, y2)
                        stbtt__handle_clipped_edge(scanline, x, e, x2, y2, x3, y3)
                    elseif x3 < x2 and x0 > x2 then -- two segments across x+1, down-left
                        stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x2, y2)
                        stbtt__handle_clipped_edge(scanline, x, e, x2, y2, x3, y3)
                    else -- one segment
                        stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x3, y3)
                    end
                end
            end
        end
        e = e.next
    end
end

-- directly AA rasterize edges w/o supersampling
--- @param result     stbtt__bitmap
--- @param e          stbtt__edge
--- @param n          int
--- @param vsubsample int
--- @param off_x      int
--- @param off_y      int
local function stbtt__rasterize_sorted_edges(result, e, n, vsubsample, off_x, off_y)
    local active = nil

    local scanline = {} -- size = result.w, 0-based
    local scanline2 = {} -- size = result.w + 1, 0-based

    STBTT__NOTUSED(vsubsample)

    local y = off_y
    e[n + 1].y0 = off_y + result.h + 1

    local j = 0
    local p = 1
    while j < result.h do
        -- find center of pixel for this scanline
        local scan_y_top = y + 0.0
        local scan_y_bottom = y + 1.0

        for i = 0, result.w - 1 do scanline[i] = 0 end
        for i = 0, result.w do scanline2[i] = 0 end

        -- update all active edges;
        -- remove all active edges that terminate before the top of this scanline
        local prev = nil
        local curr = active
        while curr do
            local next = curr.next
            if curr.ey <= scan_y_top then
                if prev then prev.next = next -- delete from list
                else          active   = next end
                curr.direction = 0
            else
                prev = curr -- advance through list
            end
            curr = next
        end

        -- insert all edges that start before the bottom of this scanline
        local edge = e[p]
        while edge.y0 <= scan_y_bottom do
            if edge.y0 ~= edge.y1 then
                local z = stbtt__new_active(edge, off_x, scan_y_top)
                if j == 0 and off_y ~= 0 and z.ey < scan_y_top then
                    -- this can happen due to subpixel positioning and some kind of fp rounding error i think
                    z.ey = scan_y_top
                end
                STBTT_assert(z.ey >= scan_y_top) -- if we get really unlucky a tiny bit of an edge can be out of bounds
                -- insert at front
                z.next = active
                active = z
            end
            p = p + 1
            edge = e[p]
        end

        -- now process all active edges
        if active then
            stbtt__fill_active_edges_new(scanline, scanline2, result.w, active, scan_y_top)
        end

        do
            local sum = 0
            for i = 0, result.w - 1 do
                local k
                local m
                sum = sum + scanline2[i]
                k = scanline[i] + sum
                k = STBTT_fabs(k) * 255 + 0.5
                m = trunc(k)
                if m > 255 then m = 255 end
                result.pixels[j * result.stride + i + 1] = unsigned_char(m)
            end
        end

        -- advance all the edges
        step = active
        while step do
            step.fx = step.fx + step.fdx -- advance to position for current scanline
            step = step.next -- advance through list
        end

        y = y + 1
        j = j + 1
    end
end

--- @param a stbtt__edge
--- @param b stbtt__edge
local STBTT__COMPARE = function(a, b)
    if a.y0 == nil then return false end -- sentinels on the back
    if b.y0 == nil then return true  end
    return a.y0 < b.y0
end

--- @param p stbtt__edge[]
local function stbtt__sort_edges(p)
    STBTT_sort(p, STBTT__COMPARE)
end

--- @param result   stbtt__bitmap
--- @param pts      stbtt__point[]
--- @param wcount   int[]
--- @param windings int
--- @param scale_x  float
--- @param scale_y  float
--- @param shift_x  float
--- @param shift_y  float
--- @param off_x    int
--- @param off_y    int
--- @param invert   bool
local function stbtt__rasterize(result, pts, wcount, windings, scale_x, scale_y, shift_x, shift_y, off_x, off_y, invert)
    local y_scale_inv = (invert) and -scale_y or scale_y
    local vsubsample = 1 -- STBTT_RASTERIZER_VERSION == 2
    -- vsubsample should divide 255 evenly; otherwise we won't reach full opacity

    -- now we have to blow out the windings into explicit edge lists
    local n = 0
    for i = 1, windings do
        n = n + wcount[i]
    end

    local e = {} for i = 1, n + 1 do e[i] = stbtt__edge() end -- add an extra one as a sentinel
    n = 0

    local m = 0
    local j
    for i = 1, windings do
        local p = m
        m = m + wcount[i]
        j = wcount[i]
        for k = 1, wcount[i] do
            repeat
            local a = k
            local b = j
            -- skip the edge if horizontal
            if pts[p + j].y == pts[p + k].y then
                break
            end
            -- add edge from j to k to the list
            n = n + 1
            e[n].invert = false
            if invert then
                if pts[p + j].y > pts[p + k].y then
                    e[n].invert = true
                    a = j
                    b = k
                end
            else
                if pts[p + j].y < pts[p + k].y then
                    e[n].invert = true
                    a = j
                    b = k
                end
            end
            e[n].x0 = pts[p + a].x * scale_x + shift_x
            e[n].y0 = (pts[p + a].y * y_scale_inv + shift_y) * vsubsample
            e[n].x1 = pts[p + b].x * scale_x + shift_x
            e[n].y1 = (pts[p + b].y * y_scale_inv + shift_y) * vsubsample

            until true
            j = k
        end
    end

    -- now sort the edges by their highest point (should snap to integer, and then by x)
    stbtt__sort_edges(e)

    -- now, traverse the scanlines and find the intersections on each scanline, use xor winding rule
    stbtt__rasterize_sorted_edges(result, e, n, vsubsample, off_x, off_y)
end

--- @param points? stbtt__point[]
--- @param n       int
--- @param x       float
--- @param y       float
local function stbtt__add_point(points, n, x, y)
    if points == nil then return end -- during first pass, it's unallocated
    points[n + 1].x = x
    points[n + 1].y = y
end

-- tessellate until threshold p is happy... @TODO warped to compensate for non-linear stretching
--- @param points?                   stbtt__point[]
--- @param num_points                int
--- @param x0                        float
--- @param y0                        float
--- @param x1                        float
--- @param y1                        float
--- @param x2                        float
--- @param y2                        float
--- @param objspace_flatness_squared float
--- @param n                         int
--- @return int num_points # updated num_points passed in
local function stbtt__tesselate_curve(points, num_points, x0, y0, x1, y1, x2, y2, objspace_flatness_squared, n)
    -- midpoint
    local mx = (x0 + 2 * x1 + x2) / 4
    local my = (y0 + 2 * y1 + y2) / 4
    -- versus directly drawn line
    local dx = (x0 + x2) / 2 - mx
    local dy = (y0 + y2) / 2 - my

    if n > 16 then -- 65536 segments on one curve better be enough!
        return num_points
    end

    if dx * dx + dy * dy > objspace_flatness_squared then -- half-pixel error allowed... need to be smaller if AA
        num_points = stbtt__tesselate_curve(points, num_points, x0, y0, (x0 + x1) / 2.0, (y0 + y1) / 2.0, mx, my, objspace_flatness_squared, n + 1)
        num_points = stbtt__tesselate_curve(points, num_points, mx, my, (x1 + x2) / 2.0, (y1 + y2) / 2.0, x2, y2, objspace_flatness_squared, n + 1)
    else
        stbtt__add_point(points, num_points, x2, y2)
        num_points = num_points + 1
    end

    return num_points
end

--- @param points?                   stbtt__point[]
--- @param num_points                int
--- @param x0                        float
--- @param y0                        float
--- @param x1                        float
--- @param y1                        float
--- @param x2                        float
--- @param y2                        float
--- @param x3                        float
--- @param y3                        float
--- @param objspace_flatness_squared float
--- @param n                         int
--- @return int num_points # updated num_points passed in
local function stbtt__tesselate_cubic(points, num_points, x0, y0, x1, y1, x2, y2, x3, y3, objspace_flatness_squared, n)
    -- @TODO this "flatness" calculation is just made-up nonsense that seems to work well enough
    local dx0 = x1 - x0
    local dy0 = y1 - y0
    local dx1 = x2 - x1
    local dy1 = y2 - y1
    local dx2 = x3 - x2
    local dy2 = y3 - y2
    local dx = x3 - x0
    local dy = y3 - y0
    local longlen = STBTT_sqrt(dx0 * dx0 + dy0 * dy0) + STBTT_sqrt(dx1 * dx1 + dy1 * dy1) + STBTT_sqrt(dx2 * dx2 + dy2 * dy2)
    local shortlen = STBTT_sqrt(dx * dx + dy * dy)
    local flatness_squared = longlen * longlen - shortlen * shortlen

    if n > 16 then -- 65536 segments on one curve better be enough!
        return num_points
    end

    if flatness_squared > objspace_flatness_squared then
        local x01 = (x0 + x1) / 2
        local y01 = (y0 + y1) / 2
        local x12 = (x1 + x2) / 2
        local y12 = (y1 + y2) / 2
        local x23 = (x2 + x3) / 2
        local y23 = (y2 + y3) / 2

        local xa = (x01 + x12) / 2
        local ya = (y01 + y12) / 2
        local xb = (x12 + x23) / 2
        local yb = (y12 + y23) / 2

        local mx = (xa + xb) / 2
        local my = (ya + yb) / 2

        num_points = stbtt__tesselate_cubic(points, num_points, x0, y0, x01, y01, xa, ya, mx, my, objspace_flatness_squared, n + 1)
        num_points = stbtt__tesselate_cubic(points, num_points, mx, my, xb, yb, x23, y23, x3, y3, objspace_flatness_squared, n + 1)
    else
        stbtt__add_point(points, num_points, x3, y3)
        num_points = num_points + 1
    end

    return num_points
end

-- returns number of contours
--- @param vertices          stbtt_vertex[]
--- @param num_verts         int
--- @param objspace_flatness float
--- @return stbtt__point[]? points
--- @return int?            num_contours
--- @return int[]?          contour_lengths
local function stbtt_FlattenCurves(vertices, num_verts, objspace_flatness)
    local points = nil
    local num_points = 0

    local objspace_flatness_squared = objspace_flatness * objspace_flatness
    local n = 0
    local start = 0

    -- count how many "moves" there are to get the contour count
    for i = 1, num_verts do
        if vertices[i].type == STBTT_VTX.MOVE then
            n = n + 1
        end
    end

    local num_contours = n
    if n == 0 then return nil end

    local contour_lengths = {} -- size = n

    -- make two passes through the points so we don't need to realloc
    for pass = 0, 1 do
        local x, y = 0, 0
        if pass == 1 then
            points = {}
            for i = 1, num_points do points[i] = stbtt__point() end
        end
        num_points = 0
        n = -1
        for i = 1, num_verts do
            if vertices[i].type == STBTT_VTX.MOVE then
                -- start the next contour
                if n >= 0 then
                    contour_lengths[n + 1] = num_points - start
                end
                n = n + 1
                start = num_points

                x = vertices[i].x
                y = vertices[i].y
                stbtt__add_point(points, num_points, x, y)
                num_points = num_points + 1
            elseif vertices[i].type == STBTT_VTX.LINE then
                x = vertices[i].x
                y = vertices[i].y
                stbtt__add_point(points, num_points, x, y)
                num_points = num_points + 1
            elseif vertices[i].type == STBTT_VTX.CURVE then
                num_points = stbtt__tesselate_curve(points, num_points, x, y,
                                    vertices[i].cx, vertices[i].cy,
                                    vertices[i].x, vertices[i].y,
                                    objspace_flatness_squared, 0)
                x = vertices[i].x
                y = vertices[i].y
            elseif vertices[i].type == STBTT_VTX.CUBIC then
                num_points = stbtt__tesselate_cubic(points, num_points, x, y,
                                    vertices[i].cx, vertices[i].cy,
                                    vertices[i].cx1, vertices[i].cy1,
                                    vertices[i].x, vertices[i].y,
                                    objspace_flatness_squared, 0)
                x = vertices[i].x
                y = vertices[i].y
            end
        end
        contour_lengths[n + 1] = num_points - start
    end

    return points, num_contours, contour_lengths
end

-- rasterize a shape with quadratic beziers into a bitmap
--- @param result             stbtt__bitmap
--- @param flatness_in_pixels float
--- @param vertices           stbtt_vertex[]
--- @param num_verts          int
--- @param scale_x            float
--- @param scale_y            float
--- @param shift_x            float
--- @param shift_y            float
--- @param x_off              int
--- @param y_off              int
--- @param invert             bool
local function stbtt_Rasterize(result, flatness_in_pixels, vertices, num_verts, scale_x, scale_y, shift_x, shift_y, x_off, y_off, invert)
    local scale = (scale_x > scale_y) and scale_y or scale_x

    local windings, winding_count, winding_lengths = stbtt_FlattenCurves(vertices, num_verts, flatness_in_pixels / scale)

    if windings then
        --- @cast winding_lengths int[]
        --- @cast winding_count   int
        stbtt__rasterize(result, windings, winding_lengths, winding_count, scale_x, scale_y, shift_x, shift_y, x_off, y_off, invert)
    end
end

-- renders the glyph into storage you pass in for the bitmap,
-- in the form of 'output', with row spacing of 'out_stride' bytes. the bitmap
-- is clipped to out_w/out_h bytes. Call stbtt_GetGlyphBitmapBox to get the
-- width and height and positioning info for it first. You can also specify
-- a subpixel shift for the character.
--- @param info       stbtt_fontinfo
--- @param output     unsigned_char[]
--- @param out_w      int
--- @param out_h      int
--- @param out_stride int
--- @param scale_x    float
--- @param scale_y    float
--- @param shift_x    float
--- @param shift_y    float
--- @param glyph      int
local function stbtt_MakeGlyphBitmapSubpixel(info, output, out_w, out_h, out_stride, scale_x, scale_y, shift_x, shift_y, glyph)
    local num_verts, vertices = stbtt_GetGlyphShape(info, glyph)
    local gbm = stbtt__bitmap()

    local ix0, iy0 = stbtt_GetGlyphBitmapBoxSubpixel(info, glyph, scale_x, scale_y, shift_x, shift_y)
    gbm.pixels = output
    gbm.w = out_w
    gbm.h = out_h
    gbm.stride = out_stride

    if gbm.w ~= 0 and gbm.h ~= 0 then
        stbtt_Rasterize(gbm, 0.35, vertices, num_verts, scale_x, scale_y, shift_x, shift_y, ix0, iy0, true)
    end
end

-----------------
-----------------
---
--- bitmap baking
---
---

--- UNIMPLEMENTED / UNUSED:
---     stbtt_BakeFontBitmap_internal
---     stbtt_BakeFontBitmap
---     stbtt_GetBakedQuad

---------------------------
---------------------------
---
--- bitmap baking / packing
---
---

--- UNIMPLEMENTED / UNUSED:
---     stbtt_PackBegin
---     stbtt_PackSetOversampling
---     stbtt_PackSetSkipMissingCodepoints
---     stbtt_PackFontRangesGatherRects
---     stbtt_PackFontRangesRenderIntoRects
---     stbtt_PackFontRangesPackRects
---     stbtt_PackFontRanges
---     stbtt_PackFontRange
---     stbtt_GetPackedQuad
---     stbtt_GetScaledFontVMetrics

local STBTT__OVER_MASK = STBTT_MAX_OVERSAMPLE - 1

--- @param pixels          table
--- @param w               int
--- @param h               int
--- @param stride_in_bytes int
--- @param kernel_width    unsigned_int
local function stbtt__h_prefilter(pixels, w, h, stride_in_bytes, kernel_width)
    local buffer = {}
    local safe_w = w - kernel_width

    for j = 0, h - 1 do
        local total = 0
        local row_offset = j * stride_in_bytes

        for i = 1, kernel_width do buffer[i] = 0 end

        for i = 0, safe_w do
            total = total + pixels[row_offset + i + 1] - buffer[bit32.band(i, STBTT__OVER_MASK) + 1]
            buffer[bit32.band(i + kernel_width, STBTT__OVER_MASK) + 1] = pixels[row_offset + i + 1]
            pixels[row_offset + i + 1] = unsigned_char(total / kernel_width)
        end

        for i = safe_w + 1, w - 1 do
            STBTT_assert(pixels[row_offset + i + 1] == 0)
            total = total - buffer[bit32.band(i, STBTT__OVER_MASK) + 1]
            pixels[row_offset + i + 1] = unsigned_char(total / kernel_width)
        end
    end
end

--- @param pixels          table
--- @param w               int
--- @param h               int
--- @param stride_in_bytes int
--- @param kernel_width    unsigned_int
local function stbtt__v_prefilter(pixels, w, h, stride_in_bytes, kernel_width)
    local buffer = {}
    local safe_h = h - kernel_width

    for j = 0, w - 1 do
        local total = 0
        local col_offset = j

        for i = 1, kernel_width do buffer[i] = 0 end

        for i = 0, safe_h do
            total = total + pixels[col_offset + i * stride_in_bytes + 1] - buffer[bit32.band(i, STBTT__OVER_MASK) + 1]
            buffer[bit32.band(i + kernel_width, STBTT__OVER_MASK) + 1] = pixels[col_offset + i * stride_in_bytes + 1]
            pixels[col_offset + i * stride_in_bytes + 1] = unsigned_char(total / kernel_width)
        end

        for i = safe_h + 1, h - 1 do
            STBTT_assert(pixels[col_offset + i * stride_in_bytes + 1] == 0)
            total = total - buffer[bit32.band(i, STBTT__OVER_MASK) + 1]
            pixels[col_offset + i * stride_in_bytes + 1] = unsigned_char(total / kernel_width)
        end
    end
end

--- @param oversample int
--- @return float
local function stbtt__oversample_shift(oversample)
    if oversample == 0 then
        return 0.0
    end

    -- The prefilter is a box filter of width "oversample",
    -- which shifts phase by (oversample - 1)/2 pixels in
    -- oversampled space. We want to shift in the opposite
    -- direction to counter this.
    return -(oversample - 1) / (2.0 * oversample)
end

-- same as stbtt_MakeGlyphBitmapSubpixel, but prefiltering
-- is performed. Returns (sub_x, sub_y).
--- @param info        stbtt_fontinfo
--- @param output      unsigned_char[]
--- @param out_w       int
--- @param out_h       int
--- @param out_stride  int
--- @param scale_x     float
--- @param scale_y     float
--- @param shift_x     float
--- @param shift_y     float
--- @param prefilter_x int
--- @param prefilter_y int
--- @param glyph       int
function stbtt_MakeGlyphBitmapSubpixelPrefilter(info, output, out_w, out_h, out_stride, scale_x, scale_y, shift_x, shift_y, prefilter_x, prefilter_y, glyph)
    stbtt_MakeGlyphBitmapSubpixel(info, output, out_w - (prefilter_x - 1), out_h - (prefilter_y - 1), out_stride, scale_x, scale_y, shift_x, shift_y, glyph)

    if prefilter_x > 1 then
        stbtt__h_prefilter(output, out_w, out_h, out_stride, prefilter_x)
    end

    if prefilter_y > 1 then
        stbtt__v_prefilter(output, out_w, out_h, out_stride, prefilter_y)
    end

    local sub_x, sub_y
    sub_x = stbtt__oversample_shift(prefilter_x)
    sub_y = stbtt__oversample_shift(prefilter_y)
    return sub_x, sub_y
end

-------------------
-------------------
---
--- sdf computation
---
---

--- UNIMPLEMENTED / UNUSED:
---     stbtt__ray_intersect_bezier
---     stbtt__compute_crossings_x
---     stbtt__cuberoot
---     stbtt__solve_cubic
---     stbtt_GetGlyphSDF
---     stbtt_GetCodepointSDF

-----------------------------------------------------
-----------------------------------------------------
---
--- Font name matching -- recommended not to use this
---
---

--- UNIMPLEMENTED / UNUSED:
---     stbtt__CompareUTF8toUTF16_bigendian_prefix
---     stbtt_CompareUTF8toUTF16_bigendian_internal
---     stbtt_GetFontNameString
---     stbtt__matchpair
---     stbtt__matches

-- Each .ttf/.ttc file may have more than one font. Each font has a sequential
-- index number starting from 0. Call this function to get the font offset for
-- a given index; it returns -1 if the index is out of range. A regular .ttf
-- file will only define one font and it always be at offset 0, so it will
-- return '0' for index 0, and -1 for all other indices.
--- @param data  table
--- @param index int
function stbtt_GetFontOffsetForIndex(data, index) return stbtt_GetFontOffsetForIndex_internal(data, index) end

-- Given an offset into the file that defines a font, this function builds
-- the necessary cached info for the rest of the system. You must allocate
-- the stbtt_fontinfo yourself (see stbtt_fontinfo()), and stbtt_InitFont will fill it out. You don't
-- need to do anything special to free it, because the contents are pure
-- value data with no additional data structures. Returns false on failure.
--- @param info   stbtt_fontinfo
--- @param data   table
--- @param offset int
function stbtt_InitFont(info, data, offset) return stbtt_InitFont_internal(info, data, offset) end

return {
    fontinfo = stbtt_fontinfo,

    InitFont                         = stbtt_InitFont,
    FindGlyphIndex                   = stbtt_FindGlyphIndex,
    MakeGlyphBitmapSubpixelPrefilter = stbtt_MakeGlyphBitmapSubpixelPrefilter,
    GetFontVMetrics                  = stbtt_GetFontVMetrics,
    GetGlyphBitmapBox                = stbtt_GetGlyphBitmapBox,
    GetGlyphBitmapBoxSubpixel        = stbtt_GetGlyphBitmapBoxSubpixel,
    GetGlyphHMetrics                 = stbtt_GetGlyphHMetrics,
    GetFontOffsetForIndex            = stbtt_GetFontOffsetForIndex,
    ScaleForPixelHeight              = stbtt_ScaleForPixelHeight
}
end

__FILES['imstd_minstdio.lua'] = function()
--- Dear ImGui
-- This is a minimal Lua impl of C-like sscanf, sprintf sub-set

-- Supports:
-- - %x, %X, %nx, %nX (where n is a number)
-- - %d, %nd (where n is a number)
-- - %f, %lf (very limited)
--
-- Returns items_matched instead of EOF on error

local _byte = string.byte

local CHAR_PERCENT = _byte'%'
local CHAR_DOT = _byte'.'
local CHAR_PLUS, CHAR_MINUS = _byte'+', _byte'-'
local CHAR_0, CHAR_9 = _byte'0', _byte'9'
local CHAR_a, CHAR_A = _byte'a', _byte'A'
local CHAR_d = _byte'd'
local CHAR_l = _byte'l'
local CHAR_f, CHAR_F = _byte'f', _byte'F'
local CHAR_x, CHAR_X = _byte'x', _byte'X'

local function isspace(c) return c == 32 or c == 9 end
local function isdigit(c) return c >= CHAR_0 and c <= CHAR_9 end
local function isxdigit(c) return isdigit(c) or (c >= CHAR_a and c <= CHAR_f) or (c >= CHAR_A and c <= CHAR_F) end

local function isdigit_under_base(c, base)
    if     base == 10 then return isdigit(c)
    elseif base == 16 then return isxdigit(c)
    end
end

local function hex_digit_to_int(c)
    if c >= CHAR_0 and c <= CHAR_9 then return c - CHAR_0 end
    if c >= CHAR_a and c <= CHAR_f then return c - CHAR_a + 10 end
    if c >= CHAR_A and c <= CHAR_F then return c - CHAR_A + 10 end
end

-- we force this behavior by default
local function clamp_if_overflow(spec, val)
    if spec == CHAR_d or spec == CHAR_x or spec == CHAR_X then
        if val > INT_MAX then return INT_MAX end
        if val < INT_MIN then return INT_MIN end
    end

    return val
end

--- @param buffer       char[]
--- @param buffer_begin int
--- @param format       string
--- @param result       table  # table to store parsed values
local function sscanf(buffer, buffer_begin, format, result)
    local p = buffer_begin
    local f = 1 -- format_begin
    local format_len = #format
    local assigned = 0
    local items_matched = 0

    while f <= format_len do
        repeat
        if isspace(_byte(format, f, f)) then
            while isspace(buffer[p]) do
                p = p + 1
            end
            f = f + 1

            break
        end

        if _byte(format, f, f) ~= CHAR_PERCENT then
            if buffer[p] == _byte(format, f, f) then
                p = p + 1
                f = f + 1
            else
                return items_matched
            end

            break
        end

        -- encountered % in fmt
        f = f + 1

        -- %%
        if _byte(format, f, f) == CHAR_PERCENT then
            if buffer[p] == CHAR_PERCENT then
                p = p + 1
                f = f + 1
            else
                return items_matched
            end

            break
        end

        -- handle optional width
        local width = 0
        while isdigit(_byte(format, f, f)) do
            width = width * 10 + _byte(format, f, f) - CHAR_0
            f = f + 1
        end
        if width == 0 then
            width = math.huge
        end

        local spec = _byte(format, f, f)
        local base
        local is_float = false
        if     spec == CHAR_x or spec == CHAR_X then
            base = 16
        elseif spec == CHAR_d then
            base = 10
        elseif spec == CHAR_f or spec == CHAR_F then
            is_float = true
        elseif spec == CHAR_l then
            f = f + 1
            if _byte(format, f, f) == CHAR_f then
                is_float = true -- TODO: distinguish from float?
            else
                return items_matched
            end
        else
            return items_matched
        end
        f = f + 1

        while isspace(buffer[p]) do
            p = p + 1
        end

        local val
        if is_float then
            local sign = 1
            if     buffer[p] == CHAR_PLUS then
                p = p + 1
            elseif buffer[p] == CHAR_MINUS then
                sign = -1
                p = p + 1
            end

            -- inf, nan are not handled

            local p_start = p
            local int_part = 0

            while isdigit(buffer[p]) do
                int_part = int_part * 10 + (buffer[p] - CHAR_0)
                p = p + 1
            end

            local frac_part = 0
            local frac_div = 1
            if buffer[p] == CHAR_DOT then
                p = p + 1
                while isdigit(buffer[p]) do
                    frac_part = frac_part * 10 + (buffer[p] - CHAR_0)
                    frac_div = frac_div * 10
                    p = p + 1
                end
            end

            if p == p_start then
                return items_matched
            end

            val = sign * (int_part + frac_part / frac_div)
        else
            local sign = 1
            -- optional sign
            if base == 10 then
                if     buffer[p] == CHAR_PLUS then
                    p = p + 1
                    width = width - 1
                elseif buffer[p] == CHAR_MINUS then
                    sign = -1
                    p = p + 1
                    width = width - 1
                end
            end

            local p_start = p
            while width > 0 and buffer[p] and isdigit_under_base(buffer[p], base) do
                p = p + 1
                width = width - 1
            end

            if p == p_start then
                -- failed to match
                return items_matched
            end

            val = 0
            while p_start < p do
                local c = buffer[p_start]
                p_start = p_start + 1
                val = val * base + sign * hex_digit_to_int(c)

                local old_val = val
                val = clamp_if_overflow(spec, val)
                if old_val ~= val then
                    break
                end
            end
        end

        result[assigned + 1] = val
        assigned = assigned + 1
        items_matched = items_matched + 1

        until true
    end

    return items_matched
end

local function sprintf()

end

return sscanf
end

IM_INCLUDE('imgui.lua')
IM_INCLUDE('imgui_impl_love.lua')
IM_INCLUDE('imgui_demo.lua')

return {
    BuildLoadGlyphGetAdvanceOrFallback = BuildLoadGlyphGetAdvanceOrFallback,
    CalcNextScrollFromScrollTargetAndClamp = CalcNextScrollFromScrollTargetAndClamp,
    DBL_MAX = DBL_MAX,
    DemoB2I = DemoB2I,
    DemoBuf = DemoBuf,
    DemoBufStr = DemoBufStr,
    DemoClamp = DemoClamp,
    DemoCollapsingHeaderClosable = DemoCollapsingHeaderClosable,
    DemoCombo = DemoCombo,
    DemoHSV = DemoHSV,
    DemoHas = DemoHas,
    DemoItems = DemoItems,
    DemoListBox = DemoListBox,
    DemoNotPorted = DemoNotPorted,
    DemoNotSupported = DemoNotSupported,
    DemoTextFilter = DemoTextFilter,
    DemoWindowLayout = DemoWindowLayout,
    DemoWindowPopups = DemoWindowPopups,
    DemoWindowTables = DemoWindowTables,
    DemoWindowWidgets = DemoWindowWidgets,
    DemoWindowWidgetsBasic = DemoWindowWidgetsBasic,
    DemoWindowWidgetsBullets = DemoWindowWidgetsBullets,
    DemoWindowWidgetsCollapsingHeaders = DemoWindowWidgetsCollapsingHeaders,
    DemoWindowWidgetsColorAndPickers = DemoWindowWidgetsColorAndPickers,
    DemoWindowWidgetsComboBoxes = DemoWindowWidgetsComboBoxes,
    DemoWindowWidgetsDataTypes = DemoWindowWidgetsDataTypes,
    DemoWindowWidgetsDisableBlocks = DemoWindowWidgetsDisableBlocks,
    DemoWindowWidgetsDragAndDrop = DemoWindowWidgetsDragAndDrop,
    DemoWindowWidgetsDragsAndSliders = DemoWindowWidgetsDragsAndSliders,
    DemoWindowWidgetsFonts = DemoWindowWidgetsFonts,
    DemoWindowWidgetsImages = DemoWindowWidgetsImages,
    DemoWindowWidgetsListBoxes = DemoWindowWidgetsListBoxes,
    DemoWindowWidgetsLiveEdit = DemoWindowWidgetsLiveEdit,
    DemoWindowWidgetsMixedValues = DemoWindowWidgetsMixedValues,
    DemoWindowWidgetsMultiComponents = DemoWindowWidgetsMultiComponents,
    DemoWindowWidgetsPlotting = DemoWindowWidgetsPlotting,
    DemoWindowWidgetsProgressBars = DemoWindowWidgetsProgressBars,
    DemoWindowWidgetsQueryingStatuses = DemoWindowWidgetsQueryingStatuses,
    DemoWindowWidgetsSelectables = DemoWindowWidgetsSelectables,
    DemoWindowWidgetsTabs = DemoWindowWidgetsTabs,
    DemoWindowWidgetsText = DemoWindowWidgetsText,
    DemoWindowWidgetsTextFilter = DemoWindowWidgetsTextFilter,
    DemoWindowWidgetsTextInput = DemoWindowWidgetsTextInput,
    DemoWindowWidgetsTooltips = DemoWindowWidgetsTooltips,
    DemoWindowWidgetsTreeNodes = DemoWindowWidgetsTreeNodes,
    DemoWindowWidgetsVerticalSliders = DemoWindowWidgetsVerticalSliders,
    DockSettingsFindNodeSettings = DockSettingsFindNodeSettings,
    DockSettingsHandler_ApplyAll = DockSettingsHandler_ApplyAll,
    DockSettingsHandler_ClearAll = DockSettingsHandler_ClearAll,
    DockSettingsHandler_ReadLine = DockSettingsHandler_ReadLine,
    DockSettingsHandler_ReadOpen = DockSettingsHandler_ReadOpen,
    DockSettingsHandler_WriteAll = DockSettingsHandler_WriteAll,
    DockSettingsRemoveNodeReferences = DockSettingsRemoveNodeReferences,
    DockSettingsRenameNodeReferences = DockSettingsRenameNodeReferences,
    ExampleImageViewerData = ExampleImageViewerData,
    ExampleImageViewer_DrawCanvas = ExampleImageViewer_DrawCanvas,
    ExampleImageViewer_DrawOptions = ExampleImageViewer_DrawOptions,
    ExampleTreeNode = ExampleTreeNode,
    ExampleTree_CreateDemoTree = ExampleTree_CreateDemoTree,
    ExampleTree_CreateNode = ExampleTree_CreateNode,
    ExampleTree_DestroyNode = ExampleTree_DestroyNode,
    FLT_MAX = FLT_MAX,
    FLT_MIN = FLT_MIN,
    FONT_ATLAS_DEFAULT_TEX_DATA_H = FONT_ATLAS_DEFAULT_TEX_DATA_H,
    FONT_ATLAS_DEFAULT_TEX_DATA_W = FONT_ATLAS_DEFAULT_TEX_DATA_W,
    FormatCached = FormatCached,
    GetDefaultFontDataProggyClean = GetDefaultFontDataProggyClean,
    GetDefaultFontDataProggyForever = GetDefaultFontDataProggyForever,
    GetMinimumStepAtDecimalPrecision = GetMinimumStepAtDecimalPrecision,
    HelpMarker = HelpMarker,
    IMGUI_DEBUG_LOG_ACTIVEID = IMGUI_DEBUG_LOG_ACTIVEID,
    IMGUI_DEBUG_LOG_CLIPPER = IMGUI_DEBUG_LOG_CLIPPER,
    IMGUI_DEBUG_LOG_DOCKING = IMGUI_DEBUG_LOG_DOCKING,
    IMGUI_DEBUG_LOG_ERROR = IMGUI_DEBUG_LOG_ERROR,
    IMGUI_DEBUG_LOG_FOCUS = IMGUI_DEBUG_LOG_FOCUS,
    IMGUI_DEBUG_LOG_FONT = IMGUI_DEBUG_LOG_FONT,
    IMGUI_DEBUG_LOG_INPUTROUTING = IMGUI_DEBUG_LOG_INPUTROUTING,
    IMGUI_DEBUG_LOG_IO = IMGUI_DEBUG_LOG_IO,
    IMGUI_DEBUG_LOG_NAV = IMGUI_DEBUG_LOG_NAV,
    IMGUI_DEBUG_LOG_POPUP = IMGUI_DEBUG_LOG_POPUP,
    IMGUI_DEBUG_LOG_SELECTION = IMGUI_DEBUG_LOG_SELECTION,
    IMGUI_DEBUG_LOG_TABLE = IMGUI_DEBUG_LOG_TABLE,
    IMGUI_DEBUG_LOG_VIEWPORT = IMGUI_DEBUG_LOG_VIEWPORT,
    IMGUI_DEMO_MARKER = IMGUI_DEMO_MARKER,
    IMGUI_DISABLE_DEBUG_TOOLS = IMGUI_DISABLE_DEBUG_TOOLS,
    IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS = IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS,
    IMGUI_FONT_SIZE_MAX = IMGUI_FONT_SIZE_MAX,
    IMGUI_FONT_SIZE_THRESHOLD_FOR_LOADADVANCEXONLYMODE = IMGUI_FONT_SIZE_THRESHOLD_FOR_LOADADVANCEXONLYMODE,
    IMGUI_PAYLOAD_TYPE_COLOR_3F = IMGUI_PAYLOAD_TYPE_COLOR_3F,
    IMGUI_PAYLOAD_TYPE_COLOR_4F = IMGUI_PAYLOAD_TYPE_COLOR_4F,
    IMGUI_PAYLOAD_TYPE_WINDOW = IMGUI_PAYLOAD_TYPE_WINDOW,
    IMGUI_TABLE_MAX_COLUMNS = IMGUI_TABLE_MAX_COLUMNS,
    IMGUI_VERSION = IMGUI_VERSION,
    IMGUI_VERSION_NUM = IMGUI_VERSION_NUM,
    IMGUI_WINDOW_HARD_MIN_SIZE = IMGUI_WINDOW_HARD_MIN_SIZE,
    IMSTB_TEXTEDIT_UNDOSTATECOUNT = IMSTB_TEXTEDIT_UNDOSTATECOUNT,
    IM_ALLOC = IM_ALLOC,
    IM_ASSERT = IM_ASSERT,
    IM_ASSERT_PARANOID = IM_ASSERT_PARANOID,
    IM_ASSERT_USER_ERROR = IM_ASSERT_USER_ERROR,
    IM_ASSERT_USER_ERROR_RET = IM_ASSERT_USER_ERROR_RET,
    IM_BITARRAY_CLEARBIT = IM_BITARRAY_CLEARBIT,
    IM_BITARRAY_TESTBIT = IM_BITARRAY_TESTBIT,
    IM_COL32 = IM_COL32,
    IM_COL32_A_MASK = IM_COL32_A_MASK,
    IM_COL32_A_SHIFT = IM_COL32_A_SHIFT,
    IM_COL32_BLACK = IM_COL32_BLACK,
    IM_COL32_BLACK_TRANS = IM_COL32_BLACK_TRANS,
    IM_COL32_B_SHIFT = IM_COL32_B_SHIFT,
    IM_COL32_DISABLE = IM_COL32_DISABLE,
    IM_COL32_G_SHIFT = IM_COL32_G_SHIFT,
    IM_COL32_R_SHIFT = IM_COL32_R_SHIFT,
    IM_COL32_WHITE = IM_COL32_WHITE,
    IM_DELETE = IM_DELETE,
    IM_DRAWLIST_ARCFAST_SAMPLE_MAX = IM_DRAWLIST_ARCFAST_SAMPLE_MAX,
    IM_DRAWLIST_ARCFAST_TABLE_SIZE = IM_DRAWLIST_ARCFAST_TABLE_SIZE,
    IM_F32_TO_INT8_SAT = IM_F32_TO_INT8_SAT,
    IM_F32_TO_INT8_UNBOUND = IM_F32_TO_INT8_UNBOUND,
    IM_FILE_CLOSE = IM_FILE_CLOSE,
    IM_FILE_READ = IM_FILE_READ,
    IM_FILE_SIZE = IM_FILE_SIZE,
    IM_FILE_WRITE = IM_FILE_WRITE,
    IM_FREE = IM_FREE,
    IM_PI = IM_PI,
    IM_ROUND = IM_ROUND,
    IM_ROUNDUP_TO_EVEN = IM_ROUNDUP_TO_EVEN,
    IM_TABSIZE = IM_TABSIZE,
    IM_TRUNC = IM_TRUNC,
    IM_UNICODE_CODEPOINT_INVALID = IM_UNICODE_CODEPOINT_INVALID,
    IM_UNICODE_CODEPOINT_MAX = IM_UNICODE_CODEPOINT_MAX,
    INT_MAX = INT_MAX,
    INT_MIN = INT_MIN,
    ImAbs = ImAbs,
    ImAcos = ImAcos,
    ImAddClampOverflow = ImAddClampOverflow,
    ImAtan2 = ImAtan2,
    ImAtof = ImAtof,
    ImBezierCubicCalc = ImBezierCubicCalc,
    ImBezierQuadraticCalc = ImBezierQuadraticCalc,
    ImBitArray = ImBitArray,
    ImBitArraySetBit = ImBitArraySetBit,
    ImCeil = ImCeil,
    ImCeilFast = ImCeilFast,
    ImCharIsBlankA = ImCharIsBlankA,
    ImCharIsBlankW = ImCharIsBlankW,
    ImCharIsSeparatorW = ImCharIsSeparatorW,
    ImClamp = ImClamp,
    ImCos = ImCos,
    ImCountSetBits = ImCountSetBits,
    ImDot = ImDot,
    ImDrawChannel = ImDrawChannel,
    ImDrawCmd = ImDrawCmd,
    ImDrawCmdHeader = ImDrawCmdHeader,
    ImDrawData = ImDrawData,
    ImDrawFlags = ImDrawFlags,
    ImDrawList = ImDrawList,
    ImDrawListFlags = ImDrawListFlags,
    ImDrawListSharedData = ImDrawListSharedData,
    ImDrawListSplitter = ImDrawListSplitter,
    ImDrawTextFlags = ImDrawTextFlags,
    ImDrawVert = ImDrawVert,
    ImDrawVtxBuffer = ImDrawVtxBuffer,
    ImDrawVtx_Col = ImDrawVtx_Col,
    ImDrawVtx_Pos = ImDrawVtx_Pos,
    ImFabs = ImFabs,
    ImFloor = ImFloor,
    ImFmod = ImFmod,
    ImFont = ImFont,
    ImFontAtlas = ImFontAtlas,
    ImFontAtlasAddDrawListSharedData = ImFontAtlasAddDrawListSharedData,
    ImFontAtlasBakedAdd = ImFontAtlasBakedAdd,
    ImFontAtlasBakedAddFontGlyph = ImFontAtlasBakedAddFontGlyph,
    ImFontAtlasBakedAddFontGlyphAdvancedX = ImFontAtlasBakedAddFontGlyphAdvancedX,
    ImFontAtlasBakedDiscard = ImFontAtlasBakedDiscard,
    ImFontAtlasBakedGetClosestMatch = ImFontAtlasBakedGetClosestMatch,
    ImFontAtlasBakedGetId = ImFontAtlasBakedGetId,
    ImFontAtlasBakedGetOrAdd = ImFontAtlasBakedGetOrAdd,
    ImFontAtlasBuildAcceptCodepointForSource = ImFontAtlasBuildAcceptCodepointForSource,
    ImFontAtlasBuildClear = ImFontAtlasBuildClear,
    ImFontAtlasBuildDestroy = ImFontAtlasBuildDestroy,
    ImFontAtlasBuildInit = ImFontAtlasBuildInit,
    ImFontAtlasBuildMain = ImFontAtlasBuildMain,
    ImFontAtlasBuildNotifySetFont = ImFontAtlasBuildNotifySetFont,
    ImFontAtlasBuildRenderBitmapFromString = ImFontAtlasBuildRenderBitmapFromString,
    ImFontAtlasBuildSetTexture = ImFontAtlasBuildSetTexture,
    ImFontAtlasBuildSetupFontBakedBlanks = ImFontAtlasBuildSetupFontBakedBlanks,
    ImFontAtlasBuildSetupFontBakedEllipsis = ImFontAtlasBuildSetupFontBakedEllipsis,
    ImFontAtlasBuildSetupFontBakedFallback = ImFontAtlasBuildSetupFontBakedFallback,
    ImFontAtlasBuildSetupFontLoader = ImFontAtlasBuildSetupFontLoader,
    ImFontAtlasBuildSetupFontSpecialGlyphs = ImFontAtlasBuildSetupFontSpecialGlyphs,
    ImFontAtlasBuildUpdateTexData = ImFontAtlasBuildUpdateTexData,
    ImFontAtlasBuildUpdateTexDataBasic = ImFontAtlasBuildUpdateTexDataBasic,
    ImFontAtlasBuildUpdateTexDataLines = ImFontAtlasBuildUpdateTexDataLines,
    ImFontAtlasBuilder = ImFontAtlasBuilder,
    ImFontAtlasFlags = ImFontAtlasFlags,
    ImFontAtlasFontDestroyOutput = ImFontAtlasFontDestroyOutput,
    ImFontAtlasFontDestroySourceData = ImFontAtlasFontDestroySourceData,
    ImFontAtlasFontDiscardBakes = ImFontAtlasFontDiscardBakes,
    ImFontAtlasFontInitOutput = ImFontAtlasFontInitOutput,
    ImFontAtlasFontSourceAddToFont = ImFontAtlasFontSourceAddToFont,
    ImFontAtlasFontSourceInit = ImFontAtlasFontSourceInit,
    ImFontAtlasGetMouseCursorTexData = ImFontAtlasGetMouseCursorTexData,
    ImFontAtlasPackAddRect = ImFontAtlasPackAddRect,
    ImFontAtlasPackDiscardRect = ImFontAtlasPackDiscardRect,
    ImFontAtlasPackGetRect = ImFontAtlasPackGetRect,
    ImFontAtlasPackGetRectSafe = ImFontAtlasPackGetRectSafe,
    ImFontAtlasPackInit = ImFontAtlasPackInit,
    ImFontAtlasPostProcessData = ImFontAtlasPostProcessData,
    ImFontAtlasRect = ImFontAtlasRect,
    ImFontAtlasRectEntry = ImFontAtlasRectEntry,
    ImFontAtlasRectId_GetGeneration = ImFontAtlasRectId_GetGeneration,
    ImFontAtlasRectId_GetIndex = ImFontAtlasRectId_GetIndex,
    ImFontAtlasRectId_Invalid = ImFontAtlasRectId_Invalid,
    ImFontAtlasRectId_Make = ImFontAtlasRectId_Make,
    ImFontAtlasRemoveDrawListSharedData = ImFontAtlasRemoveDrawListSharedData,
    ImFontAtlasTextureAdd = ImFontAtlasTextureAdd,
    ImFontAtlasTextureBlockConvert = ImFontAtlasTextureBlockConvert,
    ImFontAtlasTextureBlockCopy = ImFontAtlasTextureBlockCopy,
    ImFontAtlasTextureBlockPostProcess = ImFontAtlasTextureBlockPostProcess,
    ImFontAtlasTextureBlockPostProcessMultiply = ImFontAtlasTextureBlockPostProcessMultiply,
    ImFontAtlasTextureBlockQueueUpload = ImFontAtlasTextureBlockQueueUpload,
    ImFontAtlasTextureCompact = ImFontAtlasTextureCompact,
    ImFontAtlasTextureGetSizeEstimate = ImFontAtlasTextureGetSizeEstimate,
    ImFontAtlasTextureGrow = ImFontAtlasTextureGrow,
    ImFontAtlasUpdateDrawListsSharedData = ImFontAtlasUpdateDrawListsSharedData,
    ImFontAtlasUpdateNewFrame = ImFontAtlasUpdateNewFrame,
    ImFontBaked = ImFontBaked,
    ImFontBaked_BuildGrowIndex = ImFontBaked_BuildGrowIndex,
    ImFontBaked_BuildLoadGlyph = ImFontBaked_BuildLoadGlyph,
    ImFontBaked_BuildLoadGlyphAdvanceX = ImFontBaked_BuildLoadGlyphAdvanceX,
    ImFontCalcTextSizeEx = ImFontCalcTextSizeEx,
    ImFontCalcWordWrapPositionEx = ImFontCalcWordWrapPositionEx,
    ImFontCalcWordWrapPositionEx_Uncached = ImFontCalcWordWrapPositionEx_Uncached,
    ImFontConfig = ImFontConfig,
    ImFontFlags = ImFontFlags,
    ImFontGlyph = ImFontGlyph,
    ImFontLoader = ImFontLoader,
    ImFontStackData = ImFontStackData,
    ImFormatString = ImFormatString,
    ImGui = ImGui,
    ImGuiActivateFlags = ImGuiActivateFlags,
    ImGuiAxis = ImGuiAxis,
    ImGuiBackendFlags = ImGuiBackendFlags,
    ImGuiButtonFlags = ImGuiButtonFlags,
    ImGuiChildFlags = ImGuiChildFlags,
    ImGuiCol = ImGuiCol,
    ImGuiColorEditFlags = ImGuiColorEditFlags,
    ImGuiColorMod = ImGuiColorMod,
    ImGuiComboFlags = ImGuiComboFlags,
    ImGuiCond = ImGuiCond,
    ImGuiConfigFlags = ImGuiConfigFlags,
    ImGuiContext = ImGuiContext,
    ImGuiDataAuthority = ImGuiDataAuthority,
    ImGuiDataType = ImGuiDataType,
    ImGuiDebugLogFlags = ImGuiDebugLogFlags,
    ImGuiDemoWindowData = ImGuiDemoWindowData,
    ImGuiDir = ImGuiDir,
    ImGuiDockContext = ImGuiDockContext,
    ImGuiDockNode = ImGuiDockNode,
    ImGuiDockNodeFlags = ImGuiDockNodeFlags,
    ImGuiDockNodeState = ImGuiDockNodeState,
    ImGuiDragDropFlags = ImGuiDragDropFlags,
    ImGuiErrorRecoveryState = ImGuiErrorRecoveryState,
    ImGuiFocusRequestFlags = ImGuiFocusRequestFlags,
    ImGuiFocusScopeData = ImGuiFocusScopeData,
    ImGuiFocusedFlags = ImGuiFocusedFlags,
    ImGuiGroupData = ImGuiGroupData,
    ImGuiHoveredFlags = ImGuiHoveredFlags,
    ImGuiIO = ImGuiIO,
    ImGuiInputEvent = ImGuiInputEvent,
    ImGuiInputEventAppFocused = ImGuiInputEventAppFocused,
    ImGuiInputEventKey = ImGuiInputEventKey,
    ImGuiInputEventMouseButton = ImGuiInputEventMouseButton,
    ImGuiInputEventMousePos = ImGuiInputEventMousePos,
    ImGuiInputEventMouseViewport = ImGuiInputEventMouseViewport,
    ImGuiInputEventMouseWheel = ImGuiInputEventMouseWheel,
    ImGuiInputEventText = ImGuiInputEventText,
    ImGuiInputEventType = ImGuiInputEventType,
    ImGuiInputFlags = ImGuiInputFlags,
    ImGuiInputSource = ImGuiInputSource,
    ImGuiInputTextCallbackData = ImGuiInputTextCallbackData,
    ImGuiInputTextFlags = ImGuiInputTextFlags,
    ImGuiItemFlags = ImGuiItemFlags,
    ImGuiItemStatusFlags = ImGuiItemStatusFlags,
    ImGuiKey = ImGuiKey,
    ImGuiKeyData = ImGuiKeyData,
    ImGuiKeyOwnerData = ImGuiKeyOwnerData,
    ImGuiKeyOwner_Any = ImGuiKeyOwner_Any,
    ImGuiKeyOwner_NoOwner = ImGuiKeyOwner_NoOwner,
    ImGuiKeyRoutingData = ImGuiKeyRoutingData,
    ImGuiKey_Aliases_BEGIN = ImGuiKey_Aliases_BEGIN,
    ImGuiKey_Aliases_END = ImGuiKey_Aliases_END,
    ImGuiKey_Gamepad_BEGIN = ImGuiKey_Gamepad_BEGIN,
    ImGuiKey_Gamepad_END = ImGuiKey_Gamepad_END,
    ImGuiKey_Keyboard_BEGIN = ImGuiKey_Keyboard_BEGIN,
    ImGuiKey_Keyboard_END = ImGuiKey_Keyboard_END,
    ImGuiKey_Mouse_BEGIN = ImGuiKey_Mouse_BEGIN,
    ImGuiKey_Mouse_END = ImGuiKey_Mouse_END,
    ImGuiLastItemData = ImGuiLastItemData,
    ImGuiLastItemData_Copy = ImGuiLastItemData_Copy,
    ImGuiLayoutType = ImGuiLayoutType,
    ImGuiListClipper = ImGuiListClipper,
    ImGuiListClipperFlags = ImGuiListClipperFlags,
    ImGuiLocKey = ImGuiLocKey,
    ImGuiLogFlags = ImGuiLogFlags,
    ImGuiMod_Alt = ImGuiMod_Alt,
    ImGuiMod_Ctrl = ImGuiMod_Ctrl,
    ImGuiMod_Mask_ = ImGuiMod_Mask_,
    ImGuiMod_None = ImGuiMod_None,
    ImGuiMod_Shift = ImGuiMod_Shift,
    ImGuiMod_Super = ImGuiMod_Super,
    ImGuiMouseButton = ImGuiMouseButton,
    ImGuiMouseCursor = ImGuiMouseCursor,
    ImGuiMouseSource = ImGuiMouseSource,
    ImGuiNavLayer = ImGuiNavLayer,
    ImGuiNavMoveFlags = ImGuiNavMoveFlags,
    ImGuiNavRenderCursorFlags = ImGuiNavRenderCursorFlags,
    ImGuiNextItemData = ImGuiNextItemData,
    ImGuiNextItemDataFlags = ImGuiNextItemDataFlags,
    ImGuiNextWindowData = ImGuiNextWindowData,
    ImGuiNextWindowDataFlags = ImGuiNextWindowDataFlags,
    ImGuiOldColumnData = ImGuiOldColumnData,
    ImGuiOldColumnFlags = ImGuiOldColumnFlags,
    ImGuiOldColumns = ImGuiOldColumns,
    ImGuiPayload = ImGuiPayload,
    ImGuiPayload_Clear = ImGuiPayload_Clear,
    ImGuiPayload_IsDataType = ImGuiPayload_IsDataType,
    ImGuiPayload_IsDelivery = ImGuiPayload_IsDelivery,
    ImGuiPayload_IsPreview = ImGuiPayload_IsPreview,
    ImGuiPlatformIO = ImGuiPlatformIO,
    ImGuiPlatformImeData = ImGuiPlatformImeData,
    ImGuiPlatformImeData_Compare = ImGuiPlatformImeData_Compare,
    ImGuiPlatformImeData_Copy = ImGuiPlatformImeData_Copy,
    ImGuiPlatformMonitor = ImGuiPlatformMonitor,
    ImGuiPlotArrayGetterData = ImGuiPlotArrayGetterData,
    ImGuiPlotType = ImGuiPlotType,
    ImGuiPopupData = ImGuiPopupData,
    ImGuiPopupFlags = ImGuiPopupFlags,
    ImGuiPopupPositionPolicy = ImGuiPopupPositionPolicy,
    ImGuiScrollFlags = ImGuiScrollFlags,
    ImGuiSelectableFlags = ImGuiSelectableFlags,
    ImGuiSelectionUserData_Invalid = ImGuiSelectionUserData_Invalid,
    ImGuiSeparatorFlags = ImGuiSeparatorFlags,
    ImGuiSettingsHandler = ImGuiSettingsHandler,
    ImGuiShrinkWidthItem = ImGuiShrinkWidthItem,
    ImGuiSliderFlags = ImGuiSliderFlags,
    ImGuiSortDirection = ImGuiSortDirection,
    ImGuiStyle = ImGuiStyle,
    ImGuiStyleMod = ImGuiStyleMod,
    ImGuiStyleVar = ImGuiStyleVar,
    ImGuiStyleVarInfo = ImGuiStyleVarInfo,
    ImGuiTabBar = ImGuiTabBar,
    ImGuiTabBarFlags = ImGuiTabBarFlags,
    ImGuiTabItem = ImGuiTabItem,
    ImGuiTabItemFlags = ImGuiTabItemFlags,
    ImGuiTable = ImGuiTable,
    ImGuiTableBgTarget = ImGuiTableBgTarget,
    ImGuiTableColumn = ImGuiTableColumn,
    ImGuiTableColumnFlags = ImGuiTableColumnFlags,
    ImGuiTableColumnSettings = ImGuiTableColumnSettings,
    ImGuiTableColumnSortSpecs = ImGuiTableColumnSortSpecs,
    ImGuiTableFlags = ImGuiTableFlags,
    ImGuiTableInstanceData = ImGuiTableInstanceData,
    ImGuiTableRowFlags = ImGuiTableRowFlags,
    ImGuiTableSettings = ImGuiTableSettings,
    ImGuiTableSortSpecs = ImGuiTableSortSpecs,
    ImGuiTableTempData = ImGuiTableTempData,
    ImGuiTextBuffer = ImGuiTextBuffer,
    ImGuiTextFilter = ImGuiTextFilter,
    ImGuiTextFlags = ImGuiTextFlags,
    ImGuiTooltipFlags = ImGuiTooltipFlags,
    ImGuiTreeNodeFlags = ImGuiTreeNodeFlags,
    ImGuiViewport = ImGuiViewport,
    ImGuiViewportFlags = ImGuiViewportFlags,
    ImGuiViewportP = ImGuiViewportP,
    ImGuiWindow = ImGuiWindow,
    ImGuiWindowBgClickFlags = ImGuiWindowBgClickFlags,
    ImGuiWindowClass = ImGuiWindowClass,
    ImGuiWindowDockStyleCol = ImGuiWindowDockStyleCol,
    ImGuiWindowFlags = ImGuiWindowFlags,
    ImGuiWindowRefreshFlags = ImGuiWindowRefreshFlags,
    ImGuiWindowSettings = ImGuiWindowSettings,
    ImGuiWindowStackData = ImGuiWindowStackData,
    ImGui_ImplLOVE_CreateTexture = ImGui_ImplLOVE_CreateTexture,
    ImGui_ImplLOVE_DestroyTexture = ImGui_ImplLOVE_DestroyTexture,
    ImGui_ImplLOVE_GetBackendData = ImGui_ImplLOVE_GetBackendData,
    ImGui_ImplLOVE_Init = ImGui_ImplLOVE_Init,
    ImGui_ImplLOVE_NewFrame = ImGui_ImplLOVE_NewFrame,
    ImGui_ImplLOVE_RenderDrawData = ImGui_ImplLOVE_RenderDrawData,
    ImGui_ImplLOVE_Shutdown = ImGui_ImplLOVE_Shutdown,
    ImGui_ImplLOVE_UpdateTexture = ImGui_ImplLOVE_UpdateTexture,
    ImGui_ImplLove = ImGui_ImplLove,
    ImHashData = ImHashData,
    ImHashStr = ImHashStr,
    ImHashStrRaw = ImHashStrRaw,
    ImIsPowerOfTwo = ImIsPowerOfTwo,
    ImLengthSqr = ImLengthSqr,
    ImLerp = ImLerp,
    ImLog = ImLog,
    ImMax = ImMax,
    ImMemchr = ImMemchr,
    ImMin = ImMin,
    ImMul = ImMul,
    ImParseFormatFindStart = ImParseFormatFindStart,
    ImParseFormatSanitizeForScanning = ImParseFormatSanitizeForScanning,
    ImPool = ImPool,
    ImPow = ImPow,
    ImRect = ImRect,
    ImRect_Copy = ImRect_Copy,
    ImRect_CopyFromV4 = ImRect_CopyFromV4,
    ImRotate = ImRotate,
    ImRound64 = ImRound64,
    ImRsqrt = ImRsqrt,
    ImS16 = ImS16,
    ImS32 = ImS32,
    ImS8 = ImS8,
    ImSaturate = ImSaturate,
    ImSin = ImSin,
    ImSqrt = ImSqrt,
    ImStb = ImStb,
    ImStd = ImStd,
    ImStrByte = ImStrByte,
    ImSubClampOverflow = ImSubClampOverflow,
    ImTextClassifierClear = ImTextClassifierClear,
    ImTextClassifierGet = ImTextClassifierGet,
    ImTextClassifierSetCharClass = ImTextClassifierSetCharClass,
    ImTextClassifierSetCharClassFromStr = ImTextClassifierSetCharClassFromStr,
    ImTextInitClassifiers = ImTextInitClassifiers,
    ImTextureData = ImTextureData,
    ImTextureDataGetFormatBytesPerPixel = ImTextureDataGetFormatBytesPerPixel,
    ImTextureDataUpdateNewFrame = ImTextureDataUpdateNewFrame,
    ImTextureFormat = ImTextureFormat,
    ImTextureID_Invalid = ImTextureID_Invalid,
    ImTextureRect = ImTextureRect,
    ImTextureRef = ImTextureRef,
    ImTextureStatus = ImTextureStatus,
    ImTrunc = ImTrunc,
    ImTrunc64 = ImTrunc64,
    ImU16 = ImU16,
    ImU32 = ImU32,
    ImU8 = ImU8,
    ImUpperPowerOfTwo = ImUpperPowerOfTwo,
    ImVec1_Copy = ImVec1_Copy,
    ImVec2 = ImVec2,
    ImVec2_AddVA = ImVec2_AddVA,
    ImVec2_Copy = ImVec2_Copy,
    ImVec2_CopyV = ImVec2_CopyV,
    ImVec2_MulVX = ImVec2_MulVX,
    ImVec2_SubVA = ImVec2_SubVA,
    ImVec4 = ImVec4,
    ImVec4_Copy = ImVec4_Copy,
    ImVector = ImVector,
    ImWcharClass = ImWcharClass,
    NAV_ACTIVATE_HIGHLIGHT_TIMER = NAV_ACTIVATE_HIGHLIGHT_TIMER,
    NAV_ACTIVATE_INPUT_WITH_GAMEPAD_DELAY = NAV_ACTIVATE_INPUT_WITH_GAMEPAD_DELAY,
    NAV_WINDOWING_HIGHLIGHT_DELAY = NAV_WINDOWING_HIGHLIGHT_DELAY,
    STB_TEXTEDIT_K_BACKSPACE = STB_TEXTEDIT_K_BACKSPACE,
    STB_TEXTEDIT_K_DELETE = STB_TEXTEDIT_K_DELETE,
    STB_TEXTEDIT_K_DOWN = STB_TEXTEDIT_K_DOWN,
    STB_TEXTEDIT_K_LEFT = STB_TEXTEDIT_K_LEFT,
    STB_TEXTEDIT_K_LINEEND = STB_TEXTEDIT_K_LINEEND,
    STB_TEXTEDIT_K_LINESTART = STB_TEXTEDIT_K_LINESTART,
    STB_TEXTEDIT_K_PGDOWN = STB_TEXTEDIT_K_PGDOWN,
    STB_TEXTEDIT_K_PGUP = STB_TEXTEDIT_K_PGUP,
    STB_TEXTEDIT_K_REDO = STB_TEXTEDIT_K_REDO,
    STB_TEXTEDIT_K_RIGHT = STB_TEXTEDIT_K_RIGHT,
    STB_TEXTEDIT_K_SHIFT = STB_TEXTEDIT_K_SHIFT,
    STB_TEXTEDIT_K_TEXTEND = STB_TEXTEDIT_K_TEXTEND,
    STB_TEXTEDIT_K_TEXTSTART = STB_TEXTEDIT_K_TEXTSTART,
    STB_TEXTEDIT_K_UNDO = STB_TEXTEDIT_K_UNDO,
    STB_TEXTEDIT_K_UP = STB_TEXTEDIT_K_UP,
    STB_TEXTEDIT_K_WORDLEFT = STB_TEXTEDIT_K_WORDLEFT,
    STB_TEXTEDIT_K_WORDRIGHT = STB_TEXTEDIT_K_WORDRIGHT,
    STB_TEXTEDIT_NEWLINE = STB_TEXTEDIT_NEWLINE,
    STB_TexteditState = STB_TexteditState,
    ShowDockingDisabledMessage = ShowDockingDisabledMessage,
    ShowExampleAppAutoResize = ShowExampleAppAutoResize,
    ShowExampleAppConsole = ShowExampleAppConsole,
    ShowExampleAppConstrainedResize = ShowExampleAppConstrainedResize,
    ShowExampleAppCustomRendering = ShowExampleAppCustomRendering,
    ShowExampleAppDockSpace = ShowExampleAppDockSpace,
    ShowExampleAppDocuments = ShowExampleAppDocuments,
    ShowExampleAppFullscreen = ShowExampleAppFullscreen,
    ShowExampleAppLayout = ShowExampleAppLayout,
    ShowExampleAppLog = ShowExampleAppLog,
    ShowExampleAppLongText = ShowExampleAppLongText,
    ShowExampleAppMainMenuBar = ShowExampleAppMainMenuBar,
    ShowExampleAppPropertyEditor = ShowExampleAppPropertyEditor,
    ShowExampleAppSimpleOverlay = ShowExampleAppSimpleOverlay,
    ShowExampleAppWindowTitles = ShowExampleAppWindowTitles,
    ShowExampleMenuFile = ShowExampleMenuFile,
    UINT_MAX = UINT_MAX,
    VTX_STRIDE = VTX_STRIDE,
    _PathArcToFastExXY = _PathArcToFastExXY,
    stb_text_locate_coord = stb_text_locate_coord,
    stb_text_makeundo_delete = stb_text_makeundo_delete,
    stb_text_makeundo_insert = stb_text_makeundo_insert,
    stb_text_makeundo_replace = stb_text_makeundo_replace,
    stb_text_redo = stb_text_redo,
    stb_text_undo = stb_text_undo,
    stb_textedit_click = stb_textedit_click,
    stb_textedit_drag = stb_textedit_drag,
    stb_textedit_find_charpos = stb_textedit_find_charpos,
    stb_textedit_key = stb_textedit_key,
    stbrp_init_target = stbrp_init_target,
    stbte = stbte,
    stbtt_FindGlyphIndex = stbtt_FindGlyphIndex,
    stbtt_GetFontOffsetForIndex = stbtt_GetFontOffsetForIndex,
    stbtt_GetFontVMetrics = stbtt_GetFontVMetrics,
    stbtt_GetGlyphBitmapBox = stbtt_GetGlyphBitmapBox,
    stbtt_GetGlyphBitmapBoxSubpixel = stbtt_GetGlyphBitmapBoxSubpixel,
    stbtt_GetGlyphHMetrics = stbtt_GetGlyphHMetrics,
    stbtt_GetGlyphShape = stbtt_GetGlyphShape,
    stbtt_InitFont = stbtt_InitFont,
    stbtt_MakeGlyphBitmapSubpixelPrefilter = stbtt_MakeGlyphBitmapSubpixelPrefilter,
    stbtt_ScaleForPixelHeight = stbtt_ScaleForPixelHeight,
    stbtt__GetGlyphInfoT2 = stbtt__GetGlyphInfoT2,
    stbtt__GetGlyphShapeT2 = stbtt__GetGlyphShapeT2,
    stbtt_fontinfo = stbtt_fontinfo,
}