0.1.4

InputText: fix clipboard paste (filter was inverted, then off-by-one in the filtered buffer); ImParseFormatTrimDecorations: return [start, end) like upstream (Ctrl+click temp input showed decorations / crashed on "%d%%"); ShrinkWidths: tie order by Index descending like upstream; t_fixes test
Comments: mirror upstream imgui.cpp/.h, imgui_internal.h, widgets/draw/tables/demo and imstb_* comments (comment-only, code tokens unchanged)
2026-10-14 10:32:10 -05:00 · 2026-10-14 10:32:10 -05:00 · 2026-10-14 10:23:55 -05:00 · 2026-10-14 10:23:55 -05:00 · 2026-10-14 06:26:28 -05:00 · 2026-10-14 06:26:28 -05:00
25 changed files with 31321 additions and 8298 deletions
@@ -10,7 +10,7 @@ Dear ImGui for Roblox (and more)

 A Lua/Luau port of [Dear ImGui](https://github.com/ocornut/imgui) (docking branch, 1.93 WIP). **Roblox is the primary target** (rendered with EditableImages); the same sources also run on [LÖVE](https://love2d.org) (LuaJIT, GPU renderer), and the backend layout leaves room for more. It follows the C++ source function by function, so upstream documentation, examples and the demo apply almost directly.

-| [The Pitch](#the-pitch) - [Usage](#usage) - [How it works](#how-it-works) - [Demo](#demo) - [Getting Started & Integration](#getting-started--integration) - [Backends](#backends) |
+| [The Pitch](#the-pitch) - [Usage](#usage) - [Demo](#demo) - [Getting Started & Integration](#getting-started--integration-roblox) - [How it works](#how-it-works-roblox-backend) - [Backends](#backends) |
 :----------------------------------------------------------: |
 | [Differences from C++](#differences-from-c-dear-imgui) - [Performance](#performance) - [Testing](#testing) - [Not ported yet](#not-ported-yet) |
 | [FAQ](#faq) - [Credits](#credits) - [License](#license) |
@@ -79,27 +79,6 @@ Dear ImGui allows you to **create elaborate tools** as well as very short-lived

 Every snippet in this README is run by [`tools/test/scripts/t_readme.luau`](/tools/test/scripts/t_readme.luau), and every image was rendered by this port with [`tools/screenshots/make.py`](/tools/screenshots/make.py).

-### How it works (Roblox backend)
-
-Dear ImGui itself never draws anything: every frame it produces `ImDrawData`, a list of textured, coloured triangles plus clip rectangles, and expects the backend to put them on screen. On desktop that is a few GPU draw calls. Roblox has no API to draw arbitrary triangles in 2D, so the Roblox backend ([backends/imgui_impl_roblox.lua](/backends/imgui_impl_roblox.lua)) does what a GPU would do, in Luau, and pushes the result into **EditableImages**.
-
-**Why software rasterization?** The alternatives don't fit Dear ImGui:
- *One GUI Instance per widget/shape* (what most Roblox UI libraries do) means re-creating, re-parenting or diffing thousands of Instances every frame, can't express anti-aliased curves, per-vertex gradients or font-atlas glyphs, and would no longer be Dear ImGui's renderer output.
- *Rasterizing the draw data* keeps the output identical to Dear ImGui's: the same fonts, anti-aliasing, rounding and gradients, and every widget (including custom `ImDrawList` drawing) works without backend support.
-
-The cost is CPU time in Luau, so the backend is built around **not drawing**:
-
-1. **Layers per window.** Every draw list (one per top-level window, popup, tooltip) gets its own `Frame` with `ZIndex` following Dear ImGui's draw order. Its content is rasterized relative to the window, so **moving a window only changes the Frame's `Position`**; no pixel is redrawn or uploaded.
-2. **Tiles.** Each layer is covered by 128×128 EditableImage tiles (`ImageLabel`s). Every primitive is hashed (positions relative to the layer, UVs, colours, texture, clip) into the tiles it touches. **Only tiles whose hash changed are re-rasterized and uploaded**, and only the dirty region of those (`WritePixelsBuffer` with a sub-rectangle). A static UI uploads nothing.
-3. **Scrolling reuses pixels.** Window content is a separate layer inside a `ClipsDescendants` frame sized to the window's visible area, positioned at the scroll offset. Scrolling moves it like dragging moves a window; only rows entering view are drawn. Decorations (title bar, borders, scrollbar) stay in their own layers.
-4. **Skipping unchanged windows.** Vertices are stored in a flat Luau `buffer` (36 bytes each) instead of tables. Before any per-tile work, a window's raw vertex/index bytes are compared with last frame's; if identical, its layers are just restacked.
-5. **Fast rasterizer.** `@native` functions; axis-aligned quads (most rects and every glyph) take a span-fill path, flat rows are copied instead of re-blended, gradient rects (color pickers) are filled per row, and only real triangles (anti-aliased edges, curves) use the generic edge-function rasterizer.
-6. **Render rate.** Tiles update at most `SetRenderRate(hz)` times per second (default 60), optionally lower while scrolling/resizing (`SetBusyRenderRate`). Your UI code and Dear ImGui's logic still run every frame, so input is never dropped.
-
-**Input.** Mouse and keys come from `UserInputService`. While the mouse is over Dear ImGui (`io.WantCaptureMouse`), the tiles are `Active`, so clicks and the wheel don't reach the game (camera zoom). Games can't read the clipboard, so while a text field is active a hidden `TextBox` holds focus: the OS delivers typing (any layout), paste and copy/cut through it, and its text mirrors Dear ImGui's current selection. Fonts are TTFs rasterized by the ported stb_truetype into the font atlas, which becomes a backend texture like any image (`CreateTexture` works for your own pixels too).
-
-**Instances inside windows.** The backend can place your own Instances (e.g. a `ViewportFrame`) inside a window's layer, so they stack, clip and move with it; see the `ImGui.Embed` widget in [examples/example_roblox/main.client.luau](/examples/example_roblox/main.client.luau).
-
 ### Demo

 Calling `ImGui.ShowDemoWindow()` creates a demo window that showcases a variety of features and examples. The code is in [imgui_demo.lua](/imgui_demo.lua), like upstream's `imgui_demo.cpp`. **It's strongly recommended to keep it at hand as a reference**: you can find the code for any widget you see by searching for its label.
@@ -137,7 +116,7 @@ The Style Editor (`ImGui.ShowStyleEditor()`) and the Metrics/Debugger (`ImGui.Sh

 ### Getting Started & Integration (Roblox)

-With [Wally](https://wally.run): add `ImGui = "bug/[email protected].0"` under `[dependencies]` in your `wally.toml`, run `wally install`, then `require(ReplicatedStorage.Packages.ImGui)`. Or from source:
+With [Wally](https://wally.run) ([4dbug/imgui-luau](https://wally.run/package/4dbug/imgui-luau)): add `ImGui = "4dbug/[email protected].4"` under `[dependencies]` in your `wally.toml`, run `wally install`, then `require(ReplicatedStorage.Packages.ImGui)`. Or from source:

 1. Build the module: `python3 tools/bundle.py` writes `build/ImGui.luau` (`--no-demo` leaves the demo out) and `build/ImGuiTyped.luau`, a small typed entry module (Luau types for the public `ImGui.*` API, `ImVec2`/`ImVec4` and the flag enums) that requires `build/ImGui.luau` as its child `Impl`. The Wally package and the Rojo projects use that layout, so you get autocomplete and type errors in `--!strict` scripts. The single-file `ImGui.luau` also works on its own, just untyped.
 2. Sync with [Rojo](https://rojo.space): [`default.project.json`](/default.project.json) puts the module in `ReplicatedStorage.ImGui` and the example LocalScript in `StarterPlayerScripts`.
@@ -184,6 +163,27 @@ io.Fonts:AddFontDefault()
 io.Fonts:AddFontFromFileTTF("fonts/Roboto-Medium.ttf", 16.0)
 ```

+### How it works (Roblox backend)
+
+Dear ImGui itself never draws anything: every frame it produces `ImDrawData`, a list of textured, coloured triangles plus clip rectangles, and expects the backend to put them on screen. On desktop that is a few GPU draw calls. Roblox has no API to draw arbitrary triangles in 2D, so the Roblox backend ([backends/imgui_impl_roblox.lua](/backends/imgui_impl_roblox.lua)) does what a GPU would do, in Luau, and pushes the result into **EditableImages**.
+
+**Why software rasterization?** The alternatives don't fit Dear ImGui:
+- *One GUI Instance per widget/shape* (what most Roblox UI libraries do) means re-creating, re-parenting or diffing thousands of Instances every frame, can't express anti-aliased curves, per-vertex gradients or font-atlas glyphs, and would no longer be Dear ImGui's renderer output.
+- *Rasterizing the draw data* keeps the output identical to Dear ImGui's: the same fonts, anti-aliasing, rounding and gradients, and every widget (including custom `ImDrawList` drawing) works without backend support.
+
+The cost is CPU time in Luau, so the backend is built around **not drawing**:
+
+1. **Layers per window.** Every draw list (one per top-level window, popup, tooltip) gets its own `Frame` with `ZIndex` following Dear ImGui's draw order. Its content is rasterized relative to the window, so **moving a window only changes the Frame's `Position`**; no pixel is redrawn or uploaded.
+2. **Tiles.** Each layer is covered by 128×128 EditableImage tiles (`ImageLabel`s). Every primitive is hashed (positions relative to the layer, UVs, colours, texture, clip) into the tiles it touches. **Only tiles whose hash changed are re-rasterized and uploaded**, and only the dirty region of those (`WritePixelsBuffer` with a sub-rectangle). A static UI uploads nothing.
+3. **Scrolling reuses pixels.** Window content is a separate layer inside a `ClipsDescendants` frame sized to the window's visible area, positioned at the scroll offset. Scrolling moves it like dragging moves a window; only rows entering view are drawn. Decorations (title bar, borders, scrollbar) stay in their own layers.
+4. **Skipping unchanged windows.** Vertices are stored in a flat Luau `buffer` (36 bytes each) instead of tables. Before any per-tile work, a window's raw vertex/index bytes are compared with last frame's; if identical, its layers are just restacked.
+5. **Fast rasterizer.** `@native` functions; axis-aligned quads (most rects and every glyph) take a span-fill path, flat rows are copied instead of re-blended, gradient rects (color pickers) are filled per row, and only real triangles (anti-aliased edges, curves) use the generic edge-function rasterizer.
+6. **Render rate.** Tiles update at most `SetRenderRate(hz)` times per second (default 60), optionally lower while scrolling/resizing (`SetBusyRenderRate`). Your UI code and Dear ImGui's logic still run every frame, so input is never dropped.
+
+**Input.** Mouse and keys come from `UserInputService`. While the mouse is over Dear ImGui (`io.WantCaptureMouse`), the tiles are `Active`, so clicks and the wheel don't reach the game (camera zoom). Typing comes from key codes by default (printable ASCII). Call `ImGui_ImplRoblox.SetTextProxy(true)` to opt in to a hidden `TextBox` that holds focus while a text field is active: the OS then delivers typing (any layout), paste and copy/cut through it, and its text mirrors Dear ImGui's current selection. Fonts are TTFs rasterized by the ported stb_truetype into the font atlas, which becomes a backend texture like any image (`CreateTexture` works for your own pixels too).
+
+**Instances inside windows.** The backend can place your own Instances (e.g. a `ViewportFrame`) inside a window's layer, so they stack, clip and move with it; see the `ImGui.Embed` widget in [examples/example_roblox/main.client.luau](/examples/example_roblox/main.client.luau).
+
 ### Backends

 | Backend | File | Build | Renderer | Example |
@@ -36,6 +36,11 @@ jobs:
          python3 tools/bundle.py --no-demo dist/roblox-nodemo        # ImGui.luau (library only)
          python3 tools/bundle.py --target love dist/love             # imgui_love.lua (library + demo)
          python3 tools/bundle.py --target love --no-demo dist/love-nodemo
+          # minified variants (comments/whitespace stripped, same code): tools/minify.py
+          python3 tools/minify.py dist/roblox/ImGui.luau dist/ImGui.min.luau
+          python3 tools/minify.py dist/roblox-nodemo/ImGui.luau dist/ImGui-nodemo.min.luau
+          python3 tools/minify.py dist/love/imgui_love.lua dist/imgui_love.min.lua
+          python3 tools/minify.py dist/love-nodemo/imgui_love.lua dist/imgui_love-nodemo.min.lua

      - name: Check
        run: |
@@ -45,12 +50,25 @@ jobs:
          sed 's|require(script:WaitForChild("Impl"))|nil|' dist/roblox/ImGuiTyped.luau > /tmp/ImGuiTyped.luau && luau-analyze /tmp/ImGuiTyped.luau
          luajit -bl dist/love/imgui_love.lua > /dev/null
          luajit -bl dist/love-nodemo/imgui_love.lua > /dev/null
+          python3 tools/minify.py --test
+          luau-compile --null dist/ImGui.min.luau
+          luau-compile --null dist/ImGui-nodemo.min.luau
+          luajit -bl dist/imgui_love.min.lua > /dev/null
+          luajit -bl dist/imgui_love-nodemo.min.lua > /dev/null
          python3 tools/test/run.py --main tools/test/scripts/t_readme.luau --frames 30 --quiet --roblox --timeout 300 | tee /tmp/r.txt
          grep -q "README OK" /tmp/r.txt
          python3 tools/test/run.py --main tools/test/scripts/t_cached_window.luau --frames 130 --quiet --roblox --timeout 300 | tee /tmp/c.txt
          grep -q "CACHED OK" /tmp/c.txt
+          MINIFY=1 python3 tools/test/run.py --main tools/test/scripts/t_readme.luau --frames 30 --quiet --roblox --timeout 300 | tee /tmp/rm.txt
+          grep -q "README OK" /tmp/rm.txt
+          python3 tools/test/run.py --main tools/test/scripts/t_fixes.luau --frames 25 --quiet --roblox --timeout 300 | tee /tmp/f.txt
+          grep -q "FIXES OK" /tmp/f.txt
          python3 tools/bundle.py --target love >/dev/null
-          luajit tools/test/love/t_drawhash.lua 60 Widgets,Basic
+          luajit tools/test/love/t_drawhash.lua 60 Widgets,Basic | tee /tmp/h.txt
+          cp build/imgui_love.lua /tmp/imgui_love.lua && cp dist/imgui_love.min.lua build/imgui_love.lua
+          luajit tools/test/love/t_drawhash.lua 60 Widgets,Basic | tee /tmp/hm.txt
+          cp /tmp/imgui_love.lua build/imgui_love.lua
+          diff /tmp/h.txt /tmp/hm.txt   # minified LÖVE bundle draws exactly the same
          luajit tools/test/love/t_examples.lua

      - name: Package
@@ -80,6 +98,8 @@ jobs:
            dist/ImGui-nodemo.luau
            dist/imgui_love.lua
            dist/imgui_love-nodemo.lua
+            dist/*.min.luau
+            dist/*.min.lua
            dist/*.zip
          generate_release_notes: true

@@ -105,4 +125,4 @@ jobs:
          gh release delete latest --yes --cleanup-tag || true
          gh release create latest --latest --title "Latest build (${GITHUB_SHA::7})" \
            --notes "Automatic build of ${GITHUB_SHA} on ${GITHUB_REF_NAME}. Tag a commit v* for a versioned release." \
-            dist/ImGui.luau dist/ImGui-nodemo.luau dist/imgui_love.lua dist/imgui_love-nodemo.lua dist/*.zip
+            dist/ImGui.luau dist/ImGui-nodemo.luau dist/imgui_love.lua dist/imgui_love-nodemo.lua dist/*.min.luau dist/*.min.lua dist/*.zip
@@ -7,7 +7,7 @@ Dear ImGui for Roblox (and more)

 A Lua/Luau port of [Dear ImGui](https://github.com/ocornut/imgui) (docking branch, 1.93 WIP). **Roblox is the primary target** (rendered with EditableImages); the same sources also run on [LÖVE](https://love2d.org) (LuaJIT, GPU renderer), and the backend layout leaves room for more. It follows the C++ source function by function, so upstream documentation, examples and the demo apply almost directly.

-| [The Pitch](#the-pitch) - [Usage](#usage) - [How it works](#how-it-works) - [Demo](#demo) - [Getting Started & Integration](#getting-started--integration) - [Backends](#backends) |
+| [The Pitch](#the-pitch) - [Usage](#usage) - [Demo](#demo) - [Getting Started & Integration](#getting-started--integration-roblox) - [How it works](#how-it-works-roblox-backend) - [Backends](#backends) |
 :----------------------------------------------------------: |
 | [Differences from C++](#differences-from-c-dear-imgui) - [Performance](#performance) - [Testing](#testing) - [Not ported yet](#not-ported-yet) |
 | [FAQ](#faq) - [Credits](#credits) - [License](#license) |
@@ -76,27 +76,6 @@ Dear ImGui allows you to **create elaborate tools** as well as very short-lived

 Every snippet in this README is run by [`tools/test/scripts/t_readme.luau`](tools/test/scripts/t_readme.luau), and every image was rendered by this port with [`tools/screenshots/make.py`](tools/screenshots/make.py).

-### How it works (Roblox backend)
-
-Dear ImGui itself never draws anything: every frame it produces `ImDrawData`, a list of textured, coloured triangles plus clip rectangles, and expects the backend to put them on screen. On desktop that is a few GPU draw calls. Roblox has no API to draw arbitrary triangles in 2D, so the Roblox backend ([backends/imgui_impl_roblox.lua](backends/imgui_impl_roblox.lua)) does what a GPU would do, in Luau, and pushes the result into **EditableImages**.
-
-**Why software rasterization?** The alternatives don't fit Dear ImGui:
- *One GUI Instance per widget/shape* (what most Roblox UI libraries do) means re-creating, re-parenting or diffing thousands of Instances every frame, can't express anti-aliased curves, per-vertex gradients or font-atlas glyphs, and would no longer be Dear ImGui's renderer output.
- *Rasterizing the draw data* keeps the output identical to Dear ImGui's: the same fonts, anti-aliasing, rounding and gradients, and every widget (including custom `ImDrawList` drawing) works without backend support.
-
-The cost is CPU time in Luau, so the backend is built around **not drawing**:
-
-1. **Layers per window.** Every draw list (one per top-level window, popup, tooltip) gets its own `Frame` with `ZIndex` following Dear ImGui's draw order. Its content is rasterized relative to the window, so **moving a window only changes the Frame's `Position`**; no pixel is redrawn or uploaded.
-2. **Tiles.** Each layer is covered by 128×128 EditableImage tiles (`ImageLabel`s). Every primitive is hashed (positions relative to the layer, UVs, colours, texture, clip) into the tiles it touches. **Only tiles whose hash changed are re-rasterized and uploaded**, and only the dirty region of those (`WritePixelsBuffer` with a sub-rectangle). A static UI uploads nothing.
-3. **Scrolling reuses pixels.** Window content is a separate layer inside a `ClipsDescendants` frame sized to the window's visible area, positioned at the scroll offset. Scrolling moves it like dragging moves a window; only rows entering view are drawn. Decorations (title bar, borders, scrollbar) stay in their own layers.
-4. **Skipping unchanged windows.** Vertices are stored in a flat Luau `buffer` (36 bytes each) instead of tables. Before any per-tile work, a window's raw vertex/index bytes are compared with last frame's; if identical, its layers are just restacked.
-5. **Fast rasterizer.** `@native` functions; axis-aligned quads (most rects and every glyph) take a span-fill path, flat rows are copied instead of re-blended, gradient rects (color pickers) are filled per row, and only real triangles (anti-aliased edges, curves) use the generic edge-function rasterizer.
-6. **Render rate.** Tiles update at most `SetRenderRate(hz)` times per second (default 60), optionally lower while scrolling/resizing (`SetBusyRenderRate`). Your UI code and Dear ImGui's logic still run every frame, so input is never dropped.
-
-**Input.** Mouse and keys come from `UserInputService`. While the mouse is over Dear ImGui (`io.WantCaptureMouse`), the tiles are `Active`, so clicks and the wheel don't reach the game (camera zoom). Games can't read the clipboard, so while a text field is active a hidden `TextBox` holds focus: the OS delivers typing (any layout), paste and copy/cut through it, and its text mirrors Dear ImGui's current selection. Fonts are TTFs rasterized by the ported stb_truetype into the font atlas, which becomes a backend texture like any image (`CreateTexture` works for your own pixels too).
-
-**Instances inside windows.** The backend can place your own Instances (e.g. a `ViewportFrame`) inside a window's layer, so they stack, clip and move with it; see the `ImGui.Embed` widget in [examples/example_roblox/main.client.luau](examples/example_roblox/main.client.luau).
-
 ### Demo

 Calling `ImGui.ShowDemoWindow()` creates a demo window that showcases a variety of features and examples. The code is in [imgui_demo.lua](imgui_demo.lua), like upstream's `imgui_demo.cpp`. **It's strongly recommended to keep it at hand as a reference**: you can find the code for any widget you see by searching for its label.
@@ -134,7 +113,7 @@ The Style Editor (`ImGui.ShowStyleEditor()`) and the Metrics/Debugger (`ImGui.Sh

 ### Getting Started & Integration (Roblox)

-With [Wally](https://wally.run): add `ImGui = "bug/[email protected].0"` under `[dependencies]` in your `wally.toml`, run `wally install`, then `require(ReplicatedStorage.Packages.ImGui)`. Or from source:
+With [Wally](https://wally.run) ([4dbug/imgui-luau](https://wally.run/package/4dbug/imgui-luau)): add `ImGui = "4dbug/[email protected].4"` under `[dependencies]` in your `wally.toml`, run `wally install`, then `require(ReplicatedStorage.Packages.ImGui)`. Or from source:

 1. Build the module: `python3 tools/bundle.py` writes `build/ImGui.luau` (`--no-demo` leaves the demo out) and `build/ImGuiTyped.luau`, a small typed entry module (Luau types for the public `ImGui.*` API, `ImVec2`/`ImVec4` and the flag enums) that requires `build/ImGui.luau` as its child `Impl`. The Wally package and the Rojo projects use that layout, so you get autocomplete and type errors in `--!strict` scripts. The single-file `ImGui.luau` also works on its own, just untyped.
 2. Sync with [Rojo](https://rojo.space): [`default.project.json`](default.project.json) puts the module in `ReplicatedStorage.ImGui` and the example LocalScript in `StarterPlayerScripts`.
@@ -181,6 +160,27 @@ io.Fonts:AddFontDefault()
 io.Fonts:AddFontFromFileTTF("fonts/Roboto-Medium.ttf", 16.0)
 ```

+### How it works (Roblox backend)
+
+Dear ImGui itself never draws anything: every frame it produces `ImDrawData`, a list of textured, coloured triangles plus clip rectangles, and expects the backend to put them on screen. On desktop that is a few GPU draw calls. Roblox has no API to draw arbitrary triangles in 2D, so the Roblox backend ([backends/imgui_impl_roblox.lua](backends/imgui_impl_roblox.lua)) does what a GPU would do, in Luau, and pushes the result into **EditableImages**.
+
+**Why software rasterization?** The alternatives don't fit Dear ImGui:
+- *One GUI Instance per widget/shape* (what most Roblox UI libraries do) means re-creating, re-parenting or diffing thousands of Instances every frame, can't express anti-aliased curves, per-vertex gradients or font-atlas glyphs, and would no longer be Dear ImGui's renderer output.
+- *Rasterizing the draw data* keeps the output identical to Dear ImGui's: the same fonts, anti-aliasing, rounding and gradients, and every widget (including custom `ImDrawList` drawing) works without backend support.
+
+The cost is CPU time in Luau, so the backend is built around **not drawing**:
+
+1. **Layers per window.** Every draw list (one per top-level window, popup, tooltip) gets its own `Frame` with `ZIndex` following Dear ImGui's draw order. Its content is rasterized relative to the window, so **moving a window only changes the Frame's `Position`**; no pixel is redrawn or uploaded.
+2. **Tiles.** Each layer is covered by 128×128 EditableImage tiles (`ImageLabel`s). Every primitive is hashed (positions relative to the layer, UVs, colours, texture, clip) into the tiles it touches. **Only tiles whose hash changed are re-rasterized and uploaded**, and only the dirty region of those (`WritePixelsBuffer` with a sub-rectangle). A static UI uploads nothing.
+3. **Scrolling reuses pixels.** Window content is a separate layer inside a `ClipsDescendants` frame sized to the window's visible area, positioned at the scroll offset. Scrolling moves it like dragging moves a window; only rows entering view are drawn. Decorations (title bar, borders, scrollbar) stay in their own layers.
+4. **Skipping unchanged windows.** Vertices are stored in a flat Luau `buffer` (36 bytes each) instead of tables. Before any per-tile work, a window's raw vertex/index bytes are compared with last frame's; if identical, its layers are just restacked.
+5. **Fast rasterizer.** `@native` functions; axis-aligned quads (most rects and every glyph) take a span-fill path, flat rows are copied instead of re-blended, gradient rects (color pickers) are filled per row, and only real triangles (anti-aliased edges, curves) use the generic edge-function rasterizer.
+6. **Render rate.** Tiles update at most `SetRenderRate(hz)` times per second (default 60), optionally lower while scrolling/resizing (`SetBusyRenderRate`). Your UI code and Dear ImGui's logic still run every frame, so input is never dropped.
+
+**Input.** Mouse and keys come from `UserInputService`. While the mouse is over Dear ImGui (`io.WantCaptureMouse`), the tiles are `Active`, so clicks and the wheel don't reach the game (camera zoom). Typing comes from key codes by default (printable ASCII). Call `ImGui_ImplRoblox.SetTextProxy(true)` to opt in to a hidden `TextBox` that holds focus while a text field is active: the OS then delivers typing (any layout), paste and copy/cut through it, and its text mirrors Dear ImGui's current selection. Fonts are TTFs rasterized by the ported stb_truetype into the font atlas, which becomes a backend texture like any image (`CreateTexture` works for your own pixels too).
+
+**Instances inside windows.** The backend can place your own Instances (e.g. a `ViewportFrame`) inside a window's layer, so they stack, clip and move with it; see the `ImGui.Embed` widget in [examples/example_roblox/main.client.luau](examples/example_roblox/main.client.luau).
+
 ### Backends

 | Backend | File | Build | Renderer | Example |
@@ -862,7 +862,8 @@ function ImGui_ImplRoblox_RenderDrawData(draw_data)
    end
    if rate > 0 then
        local now = os.clock()
-        if now + 0.002 < bd.NextRender then table.clear(bd.Overlays); PE(); return end
+        -- Skipped: kept pending, so if no new frame comes (the app stopped rendering) Heartbeat still draws it
+        if now + 0.002 < bd.NextRender then bd.Pending = draw_data; PE(); return end
        bd.NextRender = math.max(bd.NextRender + 1 / rate, now)
    end

@@ -1127,8 +1128,33 @@ function ImGui_ImplRoblox_Init(parent, render_scale)
        end
    end)

-    -- Text proxy: a hidden TextBox holds focus while an imgui text field is active, so the OS gives us typing (any
-    -- layout/unicode), paste (Ctrl+V) and copy/cut (Ctrl+C/X of the proxy's text = imgui's current selection).
+    bd.PendingChars = {}
+
+    -- Render rate cap trailing edge: the last frame submitted is always drawn, even if it was skipped and the app
+    -- then stopped calling NewFrame (e.g. it rendered one empty frame to hide its windows)
+    connect(game:GetService("RunService").Heartbeat, function()
+        local d = bd.Pending
+        if d and os.clock() + 0.002 >= bd.NextRender then
+            bd.Pending = nil
+            ImGui_ImplRoblox_RenderDrawData(d)
+        end
+    end)
+
+    connect(UserInputService.WindowFocused, function() ImGui.GetIO():AddFocusEvent(true) end)
+    connect(UserInputService.WindowFocusReleased, function() ImGui.GetIO():AddFocusEvent(false) end)
+end
+
+-- Text proxy (opt-in, ImGui_ImplRoblox.SetTextProxy(true)): a hidden TextBox holds focus while an imgui text field is
+-- active, so the OS gives us typing (any layout/unicode), paste (Ctrl+V) and copy/cut (Ctrl+C/X of imgui's selection).
+-- Off: typing comes from KeyCodes (printable ASCII), no OS clipboard.
+function ImGui_ImplRoblox_SetTextProxy(enabled)
+    local bd = ImGui_ImplRoblox_GetBackendData()
+    if not enabled then
+        if bd.Proxy then bd.Proxy:Destroy(); bd.Proxy = nil end
+        proxy_focused = false
+        return
+    end
+    if bd.Proxy then return end
    local proxy = Instance.new("TextBox")
    proxy.Name = "TextProxy"
    proxy.BackgroundTransparency = 1
@@ -1140,12 +1166,11 @@ function ImGui_ImplRoblox_Init(parent, render_scale)
    proxy.ClearTextOnFocus = false
    proxy.TextEditable = true
    proxy.Text = ""
-    proxy.Parent = gui
-    bd.Proxy, bd.ProxyText, bd.PendingChars = proxy, "", {}
+    proxy.Parent = bd.Gui
+    bd.Proxy, bd.ProxyText = proxy, ""
    -- Clicking elsewhere (or Roblox taking focus) ends the edit, like clicking outside the field in imgui.
    -- (Text is polled in NewFrame instead of using Text changed signals: those are deferred in Roblox.)
-    connect(proxy.FocusLost, function()
-        if bd.ProxyDebug then print("[ImGui text proxy] FocusLost, mouse over imgui:", ImGui.GetIO().WantCaptureMouse) end
+    proxy.FocusLost:Connect(function()
        if bd.ProxyReleasing then return end
        -- Roblox drops TextBox focus on any click, including clicks inside imgui (e.g. moving the cursor within the
        -- same field). Those must not end the edit: just recapture next frame. Only a click outside imgui ends it.
@@ -1154,9 +1179,6 @@ function ImGui_ImplRoblox_Init(parent, render_scale)
        local g = ImGui.GetCurrentContext()
        if g and g.ActiveId ~= 0 and g.ActiveId == bd.ProxyActiveId then ImGui.ClearActiveID() end
    end)
-
-    connect(UserInputService.WindowFocused, function() ImGui.GetIO():AddFocusEvent(true) end)
-    connect(UserInputService.WindowFocusReleased, function() ImGui.GetIO():AddFocusEvent(false) end)
 end

 function ImGui_ImplRoblox_Shutdown()
@@ -1177,6 +1199,7 @@ function ImGui_ImplRoblox_NewFrame()
    PB("ImGui NewFrame (backend)")
    local io = ImGui.GetIO()
    local bd = ImGui_ImplRoblox_GetBackendData()
+    if bd.Pending then bd.Pending = nil; table.clear(bd.Overlays) end -- skipped frame superseded (its draw lists get reset)

    local screen = bd.Gui.AbsoluteSize
    local w, h = floor(screen.X * bd.Scale), floor(screen.Y * bd.Scale)
@@ -1201,15 +1224,16 @@ function ImGui_ImplRoblox_NewFrame()
    -- otherwise the KeyCode fallback keeps typing working.
    local proxy = bd.Proxy
    local g = ImGui.GetCurrentContext()
-    local focused_box = UserInputService:GetFocusedTextBox()
-    if io.WantTextInput and g.ActiveId ~= 0 then
+    local focused_box = proxy and UserInputService:GetFocusedTextBox()
+    if not proxy then
+        -- text proxy disabled: KeyCode typing only
+    elseif io.WantTextInput and g.ActiveId ~= 0 then
        if g.ActiveId ~= bd.ProxyActiveId or g.ActiveIdIsJustActivated or g.IO.MouseClicked[0] then bd.ProxyActiveId = g.ActiveId; bd.ProxyLostId = nil end -- (re)clicking a field recaptures
        local mouse_up = not (io.MouseDown[0] or io.MouseDown[1] or io.MouseDown[2])
        if focused_box ~= proxy and mouse_up and bd.ProxyLostId ~= g.ActiveId and (focused_box == nil or not focused_box:IsDescendantOf(game)) then
            bd.ProxyText = proxy.Text -- what it already holds is not new input (else re-typing it would collapse imgui's selection)
            proxy:CaptureFocus()
            focused_box = UserInputService:GetFocusedTextBox()
-            if bd.ProxyDebug then print("[ImGui text proxy] CaptureFocus ->", focused_box == proxy and "focused" or ("FAILED, focused = " .. tostring(focused_box))) end
        end
    elseif focused_box == proxy then
        bd.ProxyReleasing = true
@@ -1217,13 +1241,11 @@ function ImGui_ImplRoblox_NewFrame()
        bd.ProxyReleasing = false
        focused_box = nil
    end
-    local was_focused = proxy_focused
-    proxy_focused = focused_box == proxy
+    proxy_focused = proxy ~= nil and focused_box == proxy
    local used_proxy_text = false
    if proxy_focused then
        -- 1) whatever the OS put in the proxy since last frame (typing, paste, cut) replaces imgui's selection
        local text = proxy.Text
-        if text ~= bd.ProxyText and bd.ProxyDebug then print("[ImGui text proxy] text", string.format("%q", text), "was", string.format("%q", tostring(bd.ProxyText))) end
        if text ~= bd.ProxyText and text ~= bd.ProxyLastRaw then -- (LastRaw: don't re-send if our reset hasn't applied yet)
            bd.ProxyLastRaw = text
            -- InputText ignores characters while Ctrl is held (upstream, so shortcuts don't type); a paste arrives with
@@ -1259,7 +1281,6 @@ function ImGui_ImplRoblox_NewFrame()
            proxy.Text = sel
            bd.ProxyLastRaw = nil
            bd.ProxyText = sel
-            if bd.ProxyDebug then print("[ImGui text proxy] mirror selection", string.format("%q", sel)) end
        end
        -- keep imgui's selection fully selected in the proxy, so Ctrl+C copies it and typing/Ctrl+V replaces it
        local want_sel, want_cur = (#sel > 0) and 1 or -1, #sel + 1
@@ -1275,7 +1296,6 @@ function ImGui_ImplRoblox_NewFrame()
        if not used_proxy_text then for _, c in ipairs(pending) do io:AddInputCharacter(c) end end
        table.clear(pending)
    end
-    if bd.ProxyDebug and was_focused ~= proxy_focused then print("[ImGui text proxy] proxy_focused =", proxy_focused) end

    -- While the mouse is over imgui, make the tiles Active so Roblox stops passing clicks/wheel to the game (camera zoom etc.)
    local want = io.WantCaptureMouse
@@ -1317,7 +1337,7 @@ ImGui_ImplRoblox = {
    SetRenderScale = ImGui_ImplRoblox_SetRenderScale,
    SetRenderRate  = ImGui_ImplRoblox_SetRenderRate,
    SetOverlay     = ImGui_ImplRoblox_SetOverlay,
-    SetTextProxyDebug = function(on) ImGui_ImplRoblox_GetBackendData().ProxyDebug = on end, -- prints focus/text events
+    SetTextProxy   = ImGui_ImplRoblox_SetTextProxy,
    CreateTexture  = ImGui_ImplRoblox_CreateTexture,
    DestroyTexture = ImGui_ImplRoblox_DestroyTexture,
    GetRenderScale = function() return ImGui_ImplRoblox_GetBackendData().Scale end,
@@ -1 +1 @@
-[[12, "imgui.lua"], [18510, "imgui_demo.lua"], [25795, "imgui_draw.lua"], [31033, "imgui_h.lua"], [33231, "imgui_impl_roblox.lua"], [34563, "imgui_impl_roblox_fonts.lua"], [40966, "imgui_internal.lua"], [44142, "imgui_tables.lua"], [48489, "imgui_widgets.lua"], [58244, "imstb_rectpack.lua"], [58690, "imstb_textedit.lua"], [59931, "imstb_truetype.lua"], [62399, "imstd_minstdio.lua"]]
+[[12, "imgui.lua"], [21288, "imgui_demo.lua"], [29706, "imgui_draw.lua"], [35476, "imgui_h.lua"], [38142, "imgui_impl_roblox.lua"], [39494, "imgui_impl_roblox_fonts.lua"], [45897, "imgui_internal.lua"], [49343, "imgui_tables.lua"], [54338, "imgui_widgets.lua"], [64948, "imstb_rectpack.lua"], [65612, "imstb_textedit.lua"], [67154, "imstb_truetype.lua"], [69942, "imstd_minstdio.lua"]]
@@ -1 +1 @@
-[[149, "imgui.lua"], [18647, "imgui_demo.lua"], [25932, "imgui_draw.lua"], [31170, "imgui_h.lua"], [33368, "imgui_impl_love.lua"], [33908, "imgui_internal.lua"], [37084, "imgui_tables.lua"], [41431, "imgui_widgets.lua"], [51186, "imstb_rectpack.lua"], [51632, "imstb_textedit.lua"], [52873, "imstb_truetype.lua"], [55341, "imstd_minstdio.lua"]]
+[[149, "imgui.lua"], [21425, "imgui_demo.lua"], [29843, "imgui_draw.lua"], [35613, "imgui_h.lua"], [38279, "imgui_impl_love.lua"], [38819, "imgui_internal.lua"], [42265, "imgui_tables.lua"], [47260, "imgui_widgets.lua"], [57870, "imstb_rectpack.lua"], [58534, "imstb_textedit.lua"], [60076, "imstb_truetype.lua"], [62864, "imstd_minstdio.lua"]]
@@ -1,336 +1,495 @@
-- LocalScript. Build the library first: `python3 tools/bundle.py` -> build/ImGui.luau (see default.project.json)
-
 local ReplicatedStorage = game:GetService("ReplicatedStorage")
 local RunService = game:GetService("RunService")
+local AssetService = game:GetService("AssetService")

 local G = require(ReplicatedStorage:WaitForChild("ImGui"))
-local ExampleImageViewerData, ExampleImageViewer_DrawOptions, ExampleImageViewer_DrawCanvas = G.ExampleImageViewerData, G.ExampleImageViewer_DrawOptions, G.ExampleImageViewer_DrawCanvas

-local ImGui, ImVec4, ImGuiConfigFlags, ImGui_ImplRoblox = G.ImGui, G.ImVec4, G.ImGuiConfigFlags, G.ImGui_ImplRoblox
+local BaseEnvironment = getfenv()
+setfenv(1, setmetatable({}, {
+	__index = function(_, Key)
+		local Value = G[Key]
+		if Value ~= nil then
+			return Value
+		end
+		return BaseEnvironment[Key]
+	end,
+}))

-local main_scale = 1.0
-- Roblox UI points are multiplied by the OS display scale (e.g. 150%), which makes imgui look large.
-- Set this to your display scale to render imgui at physical-pixel resolution (same size as a desktop imgui app).
-local render_scale = 1.0
-local clear_color = ImVec4(0.45, 0.55, 0.60, 1.00)
-local show_demo_window = true
-local show_another_window = false
-local f = 0.0
-local counter = 0
+local MainScale = 1.0
+local RenderScale = 1.0
+local RenderRate = 60
+local ThumbnailSize = 420
+local FontSize = 13.0
+local FontNames = { "Cousine-Regular", "DroidSans", "Karla-Regular", "ProggyTiny", "Roboto-Medium" }
+
+local State = {
+	ClearColor = ImVec4(0.45, 0.55, 0.60, 1.00),
+	ShowDemoWindow = true,
+	ShowAnotherWindow = false,
+	Float = 0.0,
+	Counter = 0,
+}
+
+local Spinner = {
+	Show = true,
+	Speed = 1.0,
+	Angle = 0.0,
+	Color = ImVec4(0.80, 0.65, 0.97, 1.0),
+}

 ImGui.CreateContext()

-local io = ImGui.GetIO()
-io.ConfigFlags = bit32.bor(io.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard, ImGuiConfigFlags.DockingEnable)
+local IO = ImGui.GetIO()
+IO.ConfigFlags = bit32.bor(IO.ConfigFlags, ImGuiConfigFlags.NavEnableKeyboard, ImGuiConfigFlags.DockingEnable)

-- Catppuccin Mocha, Mauve accent (https://catppuccin.com/palette)
-local function StyleColorsCatppuccinMocha(style)
-    local function hex(h, a)
-        return ImVec4(bit32.extract(h, 16, 8) / 255, bit32.extract(h, 8, 8) / 255, bit32.extract(h, 0, 8) / 255, a or 1.0)
+-- catppuccin mocha mauve https://catppuccin.com/palette
+local function StyleColorsCatppuccinMocha(Style)
+	local function Hex(Value, Alpha)
+		return ImVec4(
+			bit32.extract(Value, 16, 8) / 255,
+			bit32.extract(Value, 8, 8) / 255,
+			bit32.extract(Value, 0, 8) / 255,
+			Alpha or 1.0
+		)
+	end
+
+	local Crust, Mantle, Base = 0x11111b, 0x181825, 0x1e1e2e
+	local Surface0, Surface1, Surface2 = 0x313244, 0x45475a, 0x585b70
+	local Overlay0, Overlay2, Text = 0x6c7086, 0x9399b2, 0xcdd6f4
+	local Mauve, Lavender = 0xcba6f7, 0xb4befe
+
+	local Entries = {
+		{ "Text", Text },
+		{ "TextDisabled", Overlay0 },
+
+		{ "WindowBg", Base },
+		{ "ChildBg", Base, 0.0 },
+		{ "PopupBg", Mantle, 0.98 },
+		{ "Border", Surface1 },
+		{ "BorderShadow", Crust, 0.0 },
+
+		{ "FrameBg", Surface0 },
+		{ "FrameBgHovered", Surface1 },
+		{ "FrameBgActive", Surface2 },
+
+		{ "TitleBg", Mantle },
+		{ "TitleBgActive", Crust },
+		{ "TitleBgCollapsed", Mantle, 0.75 },
+		{ "MenuBarBg", Mantle },
+
+		{ "ScrollbarBg", Mantle },
+		{ "ScrollbarGrab", Surface1 },
+		{ "ScrollbarGrabHovered", Surface2 },
+		{ "ScrollbarGrabActive", Overlay0 },
+
+		{ "CheckMark", Mauve },
+		{ "SliderGrab", Mauve, 0.8 },
+		{ "SliderGrabActive", Mauve },
+
+		{ "Button", Surface0 },
+		{ "ButtonHovered", Surface1 },
+		{ "ButtonActive", Mauve, 0.6 },
+
+		{ "Header", Surface0 },
+		{ "HeaderHovered", Surface1 },
+		{ "HeaderActive", Mauve, 0.5 },
+
+		{ "Separator", Surface1 },
+		{ "SeparatorHovered", Mauve, 0.7 },
+		{ "SeparatorActive", Mauve },
+
+		{ "ResizeGrip", Mauve, 0.2 },
+		{ "ResizeGripHovered", Mauve, 0.6 },
+		{ "ResizeGripActive", Mauve, 0.9 },
+
+		{ "InputTextCursor", Text },
+
+		{ "Tab", Surface0 },
+		{ "TabHovered", Surface2 },
+		{ "TabSelected", Surface1 },
+		{ "TabSelectedOverline", Mauve },
+		{ "TabDimmed", Mantle },
+		{ "TabDimmedSelected", Surface0 },
+		{ "TabDimmedSelectedOverline", Overlay0 },
+
+		{ "DockingPreview", Mauve, 0.7 },
+		{ "DockingEmptyBg", Crust },
+
+		{ "PlotLines", Overlay2 },
+		{ "PlotLinesHovered", Mauve },
+		{ "PlotHistogram", Mauve, 0.8 },
+		{ "PlotHistogramHovered", Lavender },
+
+		{ "TableHeaderBg", Surface0 },
+		{ "TableBorderStrong", Surface1 },
+		{ "TableBorderLight", Surface0 },
+		{ "TableRowBg", Base, 0.0 },
+		{ "TableRowBgAlt", Surface0, 0.3 },
+
+		{ "TextLink", Mauve },
+		{ "TextSelectedBg", Mauve, 0.35 },
+		{ "TreeLines", Surface2 },
+		{ "DragDropTarget", Mauve, 0.9 },
+
+		{ "NavCursor", Lavender },
+		{ "NavWindowingHighlight", Lavender, 0.7 },
+		{ "NavWindowingDimBg", Crust, 0.5 },
+		{ "ModalWindowDimBg", Crust, 0.6 },
+	}
+
+	for _, Entry in ipairs(Entries) do
+		local Name, Color, Alpha = Entry[1], Entry[2], Entry[3]
+		Style.Colors[ImGuiCol[Name]] = Hex(Color, Alpha)
 	end
-    local crust, mantle, base = 0x11111b, 0x181825, 0x1e1e2e
-    local surface0, surface1, surface2 = 0x313244, 0x45475a, 0x585b70
-    local overlay0, overlay2, text = 0x6c7086, 0x9399b2, 0xcdd6f4
-    local mauve, lavender = 0xcba6f7, 0xb4befe
-    local C, c = G.ImGuiCol, style.Colors
-    local function set(idx, h, a) c[idx] = hex(h, a) end
-    set(C.Text, text);                      set(C.TextDisabled, overlay0)
-    set(C.WindowBg, base);                  set(C.ChildBg, base, 0.0)
-    set(C.PopupBg, mantle, 0.98);           set(C.Border, surface1);          set(C.BorderShadow, crust, 0.0)
-    set(C.FrameBg, surface0);               set(C.FrameBgHovered, surface1);  set(C.FrameBgActive, surface2)
-    set(C.TitleBg, mantle);                 set(C.TitleBgActive, crust);      set(C.TitleBgCollapsed, mantle, 0.75)
-    set(C.MenuBarBg, mantle)
-    set(C.ScrollbarBg, mantle);             set(C.ScrollbarGrab, surface1)
-    set(C.ScrollbarGrabHovered, surface2);  set(C.ScrollbarGrabActive, overlay0)
-    set(C.CheckMark, mauve);                set(C.SliderGrab, mauve, 0.8);    set(C.SliderGrabActive, mauve)
-    set(C.Button, surface0);                set(C.ButtonHovered, surface1);   set(C.ButtonActive, mauve, 0.6)
-    set(C.Header, surface0);                set(C.HeaderHovered, surface1);   set(C.HeaderActive, mauve, 0.5)
-    set(C.Separator, surface1);             set(C.SeparatorHovered, mauve, 0.7); set(C.SeparatorActive, mauve)
-    set(C.ResizeGrip, mauve, 0.2);          set(C.ResizeGripHovered, mauve, 0.6); set(C.ResizeGripActive, mauve, 0.9)
-    set(C.InputTextCursor, text)
-    set(C.TabHovered, surface2);            set(C.Tab, surface0)
-    set(C.TabSelected, surface1);           set(C.TabSelectedOverline, mauve)
-    set(C.TabDimmed, mantle);               set(C.TabDimmedSelected, surface0); set(C.TabDimmedSelectedOverline, overlay0)
-    set(C.DockingPreview, mauve, 0.7);      set(C.DockingEmptyBg, crust)
-    set(C.PlotLines, overlay2);             set(C.PlotLinesHovered, mauve)
-    set(C.PlotHistogram, mauve, 0.8);       set(C.PlotHistogramHovered, lavender)
-    set(C.TableHeaderBg, surface0);         set(C.TableBorderStrong, surface1); set(C.TableBorderLight, surface0)
-    set(C.TableRowBg, base, 0.0);           set(C.TableRowBgAlt, surface0, 0.3)
-    set(C.TextLink, mauve);                 set(C.TextSelectedBg, mauve, 0.35)
-    set(C.TreeLines, surface2)
-    set(C.DragDropTarget, mauve, 0.9)
-    set(C.NavCursor, lavender);             set(C.NavWindowingHighlight, lavender, 0.7)
-    set(C.NavWindowingDimBg, crust, 0.5);   set(C.ModalWindowDimBg, crust, 0.6)
 end

-local style = ImGui.GetStyle()
-StyleColorsCatppuccinMocha(style)
-style:ScaleAllSizes(main_scale)
-style.FontScaleDpi = main_scale
+local Style = ImGui.GetStyle()
+StyleColorsCatppuccinMocha(Style)
+Style:ScaleAllSizes(MainScale)
+Style.FontScaleDpi = MainScale

-- Fonts: ProggyClean stays the default (added first); the rest show up in Style Editor > Fonts
-io.Fonts:AddFontDefault()
-for _, name in ipairs({ "Cousine-Regular", "DroidSans", "Karla-Regular", "ProggyTiny", "Roboto-Medium" }) do
-    io.Fonts:AddFontFromFileTTF("fonts/" .. name .. ".ttf", 13.0)
+IO.Fonts:AddFontDefault()
+for _, Name in ipairs(FontNames) do
+	IO.Fonts:AddFontFromFileTTF("fonts/" .. Name .. ".ttf", FontSize)
 end

-ImGui_ImplRoblox.Init(nil, render_scale)
-ImGui_ImplRoblox.SetRenderRate(60) -- tile redraws per second; imgui logic + your code still run every frame
-- ImGui_ImplRoblox.SetBusyRenderRate(30) -- optional: lower redraw rate while scrolling/resizing/moving windows
-ImGui_ImplRoblox.SetProfiling(true) -- MicroProfiler (Ctrl+F6) labels; turn off when not profiling
+ImGui_ImplRoblox.Init(nil, RenderScale)
+ImGui_ImplRoblox.SetRenderRate(RenderRate)
+-- ImGui_ImplRoblox.SetBusyRenderRate(30) -- Optional: lower redraw rate while scrolling/resizing/moving windows
+-- ImGui_ImplRoblox.SetProfiling(true)    -- MicroProfiler labels; turn off when not profiling
+-- ImGui_ImplRoblox.SetTextProxy(true)     -- Optional: hidden TextBox for OS typing (any layout), paste and copy/cut
+
+local function ProfileBegin(Name)
+	if ImGui_ImplRoblox.IsProfiling() then
+		debug.profilebegin(Name)
+	end
+end
+
+local function ProfileEnd()
+	if ImGui_ImplRoblox.IsProfiling() then
+		debug.profileend()
+	end
+end

-local function P(name) if ImGui_ImplRoblox.IsProfiling() then debug.profilebegin(name) end end
-local function PE() if ImGui_ImplRoblox.IsProfiling() then debug.profileend() end end

--------------------------------------------------------------------------------------------------------------------
-- Custom widget: ImGui.Embed(id, size, flags, init) -> Frame
-- Reserves a widget-sized area in the current window and shows a real Frame there, so any Instances (UI, a
-- ViewportFrame, ...) can live inside an imgui window. Immediate-mode friendly:
--   * one Frame per id (per window, through the ID stack, like any widget); `init(frame)` runs only when it is created
--   * call it every frame the Frame should be visible; when it isn't called (window closed/collapsed, tab or tree node
--     closed, scrolled fully out of view) the Frame is hidden, never destroyed, so your Instances keep their state
--   * size uses imgui sizing (ImVec2(-1, h) = fill width, 0 = default), style gives padding/rounding/background/border
--   * returns the Frame: edit properties, add or remove children any time
-- ImGui.DestroyEmbed(id) removes it for good (call while the same window is current, like the widget itself).
--------------------------------------------------------------------------------------------------------------------
 local EmbedFlags = {
 	None         = 0,
-    NoClip       = 1,  -- don't clip to the window's content area (still moves/hides/stacks with the window)
-    NoBackground = 2,  -- no FrameBg behind the Frame
-    NoBorder     = 4,  -- no style border
-    NoPadding    = 8,  -- no FramePadding inside the Frame (UIPadding)
-    NoRounding   = 16, -- no FrameRounding corners (UICorner)
+	NoClip       = 1,  -- Don't clip to the window's content area (still moves/hides/stacks with the window)
+	NoBackground = 2,  -- No FrameBg behind the Frame
+	NoBorder     = 4,  -- No style border
+	NoPadding    = 8,  -- No FramePadding inside the Frame (UIPadding)
+	NoRounding   = 16, -- No FrameRounding corners (UICorner)
 }
+
 G.ImGuiEmbedFlags = EmbedFlags

-local embeds = {} -- [ImGuiID] = { Frame, Padding, Corner }
+local Embeds = {}

-function ImGui.Embed(id, size, flags, init)
-    flags = flags or EmbedFlags.None
-    local window = ImGui.GetCurrentWindow()
-    local gid = window:GetID(id)
-    local e = embeds[gid]
-    if not e then
-        local frame = Instance.new("Frame")
-        frame.Name = tostring(id)
-        frame.BackgroundTransparency = 1
-        frame.BorderSizePixel = 0
-        frame.Visible = false
-        e = { Frame = frame, Padding = Instance.new("UIPadding"), Corner = Instance.new("UICorner") }
-        e.Padding.Parent = frame
-        e.Corner.Parent = frame
-        embeds[gid] = e
-        if init then init(frame) end
-    end
-    if window.SkipItems then return e.Frame end
-
-    local style = ImGui.GetStyle()
-    local sz = ImGui.CalcItemSize(size or G.ImVec2(0, 0), ImGui.CalcItemWidth(), ImGui.GetFrameHeight() * 4)
-    local p = window.DC.CursorPos
-    local bb = G.ImRect(p.x, p.y, p.x + sz.x, p.y + sz.y)
-    ImGui.ItemSize(sz)
-    if not ImGui.ItemAdd(bb, gid) then return e.Frame end -- fully clipped: not submitted -> hidden this frame
-
-    local rounding = bit32.band(flags, EmbedFlags.NoRounding) == 0 and style.FrameRounding or 0
-    if bit32.band(flags, EmbedFlags.NoBackground) == 0 then
-        ImGui.RenderFrame(bb.Min, bb.Max, ImGui.GetColorU32(G.ImGuiCol.FrameBg), bit32.band(flags, EmbedFlags.NoBorder) == 0, rounding)
-    elseif bit32.band(flags, EmbedFlags.NoBorder) == 0 then
-        ImGui.RenderFrameBorder(bb.Min, bb.Max, rounding)
-    end
-
-    -- style -> Instances (only written when changed)
-    local scale = ImGui_ImplRoblox.GetRenderScale()
-    local px, py = 0, 0
-    if bit32.band(flags, EmbedFlags.NoPadding) == 0 then px, py = style.FramePadding.x / scale, style.FramePadding.y / scale end
-    if e.PX ~= px or e.PY ~= py then
-        e.PX, e.PY = px, py
-        e.Padding.PaddingLeft, e.Padding.PaddingRight = UDim.new(0, px), UDim.new(0, px)
-        e.Padding.PaddingTop, e.Padding.PaddingBottom = UDim.new(0, py), UDim.new(0, py)
-    end
-    if e.R ~= rounding then e.R = rounding; e.Corner.CornerRadius = UDim.new(0, rounding / scale) end
-
-    ImGui_ImplRoblox.SetOverlay(e.Frame, bb.Min.x, bb.Min.y, sz.x, sz.y, bit32.band(flags, EmbedFlags.NoClip) == 0)
-    return e.Frame
+local function HasFlag(Flags, Flag)
+	return bit32.band(Flags, Flag) ~= 0
 end

-function ImGui.DestroyEmbed(id)
-    local gid = ImGui.GetCurrentWindow():GetID(id)
-    local e = embeds[gid]
-    if e then e.Frame:Destroy(); embeds[gid] = nil end
+local function CreateEmbed(Id)
+	local Frame = Instance.new("Frame")
+	Frame.Name = tostring(Id)
+	Frame.BackgroundTransparency = 1
+	Frame.BorderSizePixel = 0
+	Frame.Visible = false
+
+	local Padding = Instance.new("UIPadding")
+	Padding.Parent = Frame
+
+	local Corner = Instance.new("UICorner")
+	Corner.Parent = Frame
+
+	return { Frame = Frame, Padding = Padding, Corner = Corner }
 end

-- Example: Decal Viewer. Loads a decal/image asset's pixels into an imgui texture and shows it in the demo's
-- image viewer (zoom with the wheel, drag to pan, toggleable pixel grid).
-local AssetService = game:GetService("AssetService")
-local MarketplaceService = game:GetService("MarketplaceService")
-local decal = { input = ImGui.NewTextBuffer("", 32), status = "Enter a decal or image id", tex = nil, w = 0, h = 0, loading = false,
-                viewer = ExampleImageViewerData(), show = true }
+function ImGui.Embed(Id, Size, Flags, Init)
+	Flags = Flags or EmbedFlags.None

-- A Decal asset wraps an Image asset with a different id; the image is almost always uploaded just before it
-- (same creator, id slightly lower). ponytail: heuristic scan of 10 ids, InsertService:LoadAsset when owned is exact.
-local function ResolveImageId(id)
-    local ok, info = pcall(MarketplaceService.GetProductInfo, MarketplaceService, id)
-    if not ok then return nil, "GetProductInfo failed: " .. tostring(info) end
-    if info.AssetTypeId == 1 then return id end -- already an Image
-    if info.AssetTypeId ~= 13 then return nil, "asset is not a decal or image" end
-    for cand = id - 1, id - 10, -1 do
-        local ok2, ci = pcall(MarketplaceService.GetProductInfo, MarketplaceService, cand)
-        if ok2 and ci.AssetTypeId == 1 and ci.Creator and info.Creator and ci.Creator.Id == info.Creator.Id then return cand end
+	local Window = ImGui.GetCurrentWindow()
+	local GuiId = Window:GetID(Id)
+
+	local Embed = Embeds[GuiId]
+	if not Embed then
+		Embed = CreateEmbed(Id)
+		Embeds[GuiId] = Embed
+
+		if Init then
+			Init(Embed.Frame)
 		end
-    return nil, "couldn't find the decal's image id (try the image id directly)"
+	end
+
+	if Window.SkipItems then
+		return Embed.Frame
+	end
+
+	local EmbedStyle = ImGui.GetStyle()
+	local ItemSize = ImGui.CalcItemSize(
+		Size or ImVec2(0, 0),
+		ImGui.CalcItemWidth(),
+		ImGui.GetFrameHeight() * 4
+	)
+	local CursorPos = Window.DC.CursorPos
+	local BoundingBox = ImRect(CursorPos.x, CursorPos.y, CursorPos.x + ItemSize.x, CursorPos.y + ItemSize.y)
+
+	ImGui.ItemSize(ItemSize)
+	if not ImGui.ItemAdd(BoundingBox, GuiId) then
+		return Embed.Frame
+	end
+
+	local Rounding = HasFlag(Flags, EmbedFlags.NoRounding) and 0 or EmbedStyle.FrameRounding
+	local ShowBorder = not HasFlag(Flags, EmbedFlags.NoBorder)
+
+	if not HasFlag(Flags, EmbedFlags.NoBackground) then
+		ImGui.RenderFrame(
+			BoundingBox.Min,
+			BoundingBox.Max,
+			ImGui.GetColorU32(ImGuiCol.FrameBg),
+			ShowBorder,
+			Rounding
+		)
+	elseif ShowBorder then
+		ImGui.RenderFrameBorder(BoundingBox.Min, BoundingBox.Max, Rounding)
+	end
+
+	local Scale = ImGui_ImplRoblox.GetRenderScale()
+	local PaddingX, PaddingY = 0, 0
+
+	if not HasFlag(Flags, EmbedFlags.NoPadding) then
+		PaddingX = EmbedStyle.FramePadding.x / Scale
+		PaddingY = EmbedStyle.FramePadding.y / Scale
+	end
+
+	if Embed.PaddingX ~= PaddingX or Embed.PaddingY ~= PaddingY then
+		Embed.PaddingX, Embed.PaddingY = PaddingX, PaddingY
+
+		local Padding = Embed.Padding
+		Padding.PaddingLeft = UDim.new(0, PaddingX)
+		Padding.PaddingRight = UDim.new(0, PaddingX)
+		Padding.PaddingTop = UDim.new(0, PaddingY)
+		Padding.PaddingBottom = UDim.new(0, PaddingY)
+	end
+
+	if Embed.Rounding ~= Rounding then
+		Embed.Rounding = Rounding
+		Embed.Corner.CornerRadius = UDim.new(0, Rounding / Scale)
+	end
+
+	ImGui_ImplRoblox.SetOverlay(
+		Embed.Frame,
+		BoundingBox.Min.x,
+		BoundingBox.Min.y,
+		ItemSize.x,
+		ItemSize.y,
+		not HasFlag(Flags, EmbedFlags.NoClip)
+	)
+
+	return Embed.Frame
 end

-local function LoadDecal(id)
-    decal.loading = true
-    decal.status = "Loading " .. id .. "..."
+function ImGui.DestroyEmbed(Id)
+	local GuiId = ImGui.GetCurrentWindow():GetID(Id)
+	local Embed = Embeds[GuiId]
+
+	if Embed then
+		Embed.Frame:Destroy()
+		Embeds[GuiId] = nil
+	end
+end
+
+
+local Decal = {
+	Show = true,
+	Input = ImGui.NewTextBuffer("", 32),
+	Status = "Enter a decal or image id",
+	Loading = false,
+	Texture = nil,
+	Width = 0,
+	Height = 0,
+	Viewer = ExampleImageViewerData(),
+}
+
+local function LoadDecal(Id)
+	Decal.Loading = true
+	Decal.Status = "Loading " .. Id .. "..."
+
 	task.spawn(function()
-        local image_id, err = ResolveImageId(id)
-        decal.thumb = nil
-        if image_id then
-            -- 1) the image itself (needs permission), 2) its 420x420 thumbnail (may be allowed when 1 isn't)
-            local ok, img = pcall(AssetService.CreateEditableImageAsync, AssetService, Content.fromUri("rbxassetid://" .. image_id))
-            if not ok then
-                local ok2, img2 = pcall(AssetService.CreateEditableImageAsync, AssetService, Content.fromUri("rbxthumb://type=Asset&id=" .. id .. "&w=420&h=420"))
-                if ok2 then ok, img = true, img2 end
+		local Uri = string.format("rbxthumb://type=Asset&id=%d&w=%d&h=%d", Id, ThumbnailSize, ThumbnailSize)
+		local Success, Result = pcall(AssetService.CreateEditableImageAsync, AssetService, Content.fromUri(Uri))
+
+		if Success then
+			local Size = Result.Size
+			local Pixels = Result:ReadPixelsBuffer(Vector2.zero, Size)
+			Result:Destroy()
+
+			if Decal.Texture then
+				ImGui_ImplRoblox.DestroyTexture(Decal.Texture)
 			end
-            if ok then
-                local size = img.Size
-                local pixels = img:ReadPixelsBuffer(Vector2.zero, size)
-                img:Destroy()
-                if decal.tex then ImGui_ImplRoblox.DestroyTexture(decal.tex) end
-                decal.thumb = nil
-                decal.tex, decal.w, decal.h = ImGui_ImplRoblox.CreateTexture(pixels, size.X, size.Y), size.X, size.Y
-                decal.viewer.ViewReset = true
-                decal.status = string.format("Image %d: %dx%d", image_id, size.X, size.Y)
+
+			Decal.Texture = ImGui_ImplRoblox.CreateTexture(Pixels, Size.X, Size.Y)
+			Decal.Width, Decal.Height = Size.X, Size.Y
+			Decal.Viewer.ViewReset = true
+			Decal.Status = string.format("Thumbnail %d: %dx%d", Id, Size.X, Size.Y)
 		else
-                -- 3) no pixel access: Roblox still displays any asset, so show its thumbnail in an ImageLabel (no grid)
-                decal.thumb = "rbxthumb://type=Asset&id=" .. id .. "&w=420&h=420"
-                decal.status = "No pixel access (asset not owned by this experience's creator): display only, no zoom/grid"
+			Decal.Status = "Failed to load thumbnail: " .. tostring(Result)
 		end
-        else
-            decal.thumb = "rbxthumb://type=Asset&id=" .. id .. "&w=420&h=420"
-            decal.status = (err or "") .. " - showing thumbnail"
-        end
-        decal.loading = false
+
+		Decal.Loading = false
 	end)
 end

 local function ShowDecalViewer()
-    if not decal.show then return end
-    decal.show = ImGui.Begin("Decal Viewer", decal.show)
+	if not Decal.Show then
+		return
+	end
+
+	Decal.Show = ImGui.Begin("Decal Viewer", Decal.Show)
+
 	ImGui.SetNextItemWidth(ImGui.GetFontSize() * 12)
-    local enter = ImGui.InputTextWithHint("##id", "decal id", decal.input, 32, G.ImGuiInputTextFlags.CharsDecimal + G.ImGuiInputTextFlags.EnterReturnsTrue)
+	local EnterPressed = ImGui.InputTextWithHint(
+		"##id",
+		"decal id",
+		Decal.Input,
+		32,
+		ImGuiInputTextFlags.CharsDecimal + ImGuiInputTextFlags.EnterReturnsTrue
+	)
+
 	ImGui.SameLine()
-    ImGui.BeginDisabled(decal.loading)
-    if (ImGui.Button("Load") or enter) and not decal.loading then
-        local id = tonumber(ImGui.TextBufferToString(decal.input))
-        if id then LoadDecal(id) else decal.status = "Not a number" end
+	ImGui.BeginDisabled(Decal.Loading)
+	if (ImGui.Button("Load") or EnterPressed) and not Decal.Loading then
+		local Id = tonumber(ImGui.TextBufferToString(Decal.Input))
+		if Id and Id == math.floor(Id) then
+			LoadDecal(Id)
+		else
+			Decal.Status = "Not a valid id"
+		end
 	end
 	ImGui.EndDisabled()
-    ImGui.SameLine(); ImGui.TextDisabled(decal.status)
-    if decal.thumb then
-        local avail = ImGui.GetContentRegionAvail()
-        local frame = ImGui.Embed("decal_thumb", G.ImVec2(-1, math.max(avail.y, 50)), G.ImGuiEmbedFlags.None, function(f)
-            local img = Instance.new("ImageLabel")
-            img.Name = "Image"
-            img.Size = UDim2.fromScale(1, 1)
-            img.BackgroundTransparency = 1
-            img.ScaleType = Enum.ScaleType.Fit
-            img.Parent = f
-        end)
-        if frame.Image.Image ~= decal.thumb then frame.Image.Image = decal.thumb end
-    elseif decal.tex then
-        ExampleImageViewer_DrawOptions(decal.viewer)
-        local avail = ImGui.GetContentRegionAvail()
-        ExampleImageViewer_DrawCanvas(decal.viewer, G.ImVec2(math.max(avail.x, 50), math.max(avail.y, 50)), decal.tex, decal.w, decal.h)
+
+	ImGui.SameLine()
+	ImGui.TextDisabled(Decal.Status)
+
+	if Decal.Texture then
+		ExampleImageViewer_DrawOptions(Decal.Viewer)
+
+		local Available = ImGui.GetContentRegionAvail()
+		ExampleImageViewer_DrawCanvas(
+			Decal.Viewer,
+			ImVec2(math.max(Available.x, 50), math.max(Available.y, 50)),
+			Decal.Texture,
+			Decal.Width,
+			Decal.Height
+		)
 	end
+
 	ImGui.End()
 end

-- Example: a ViewportFrame with a spinning part, edited live from imgui widgets
-local spin_speed = 1.0
-local part_color = ImVec4(0.80, 0.65, 0.97, 1.0)
-local spin_angle = 0.0
-local show_viewport_window = true
-
-RunService.Stepped:Connect(function()
-    P("ImGui frame")
-    ImGui_ImplRoblox.NewFrame()
-    P("ImGui.NewFrame"); ImGui.NewFrame(); PE()
-    P("ImGui UI")
-
-    -- Dockspace covering the whole screen; the centre stays transparent so the game shows through
-    ImGui.DockSpaceOverViewport(0, nil, G.ImGuiDockNodeFlags.PassthruCentralNode)
-
-    if show_demo_window then
-        ImGui.ShowDemoWindow()
-    end
-
-    do
+local function ShowHelloWindow()
 	ImGui.Begin("Hello, world!")

 	ImGui.Text("This is some useful text.")
-        local _
-        _, show_demo_window = ImGui.Checkbox("Demo Window", show_demo_window)
-        _, show_another_window = ImGui.Checkbox("Another Window", show_another_window)

-        f = ImGui.SliderFloat("float", f, 0.0, 1.0)
-        ImGui.ColorEdit3("clear color", clear_color)
+	local _
+	_, State.ShowDemoWindow = ImGui.Checkbox("Demo Window", State.ShowDemoWindow)
+	_, State.ShowAnotherWindow = ImGui.Checkbox("Another Window", State.ShowAnotherWindow)
+
+	State.Float = ImGui.SliderFloat("float", State.Float, 0.0, 1.0)
+	ImGui.ColorEdit3("clear color", State.ClearColor)

 	if ImGui.Button("Button") then
-            counter = counter + 1
+		State.Counter += 1
 	end
 	ImGui.SameLine()
-        ImGui.Text("counter = %d", counter)
+	ImGui.Text("counter = %d", State.Counter)

-        ImGui.Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0 / io.Framerate, io.Framerate)
+	ImGui.Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0 / IO.Framerate, IO.Framerate)

 	ImGui.End()
+end
+
+local function ShowAnotherWindow()
+	if not State.ShowAnotherWindow then
+		return
 	end

-    if show_another_window then
-        show_another_window = ImGui.Begin("Another Window", show_another_window)
+	State.ShowAnotherWindow = ImGui.Begin("Another Window", State.ShowAnotherWindow)

 	ImGui.Text("Hello from another window!")
 	if ImGui.Button("Close Me") then
-            show_another_window = false
+		State.ShowAnotherWindow = false
 	end

 	ImGui.End()
+end
+
+local function CreateSpinnerViewport(Container)
+	local Viewport = Instance.new("ViewportFrame")
+	Viewport.Size = UDim2.fromScale(1, 1)
+	Viewport.BackgroundTransparency = 1
+	Viewport.Parent = Container
+
+	local Camera = Instance.new("Camera")
+	Camera.CFrame = CFrame.lookAt(Vector3.new(0, 2, 6), Vector3.zero)
+	Camera.Parent = Viewport
+	Viewport.CurrentCamera = Camera
+
+	local Part = Instance.new("Part")
+	Part.Name = "Spinner"
+	Part.Size = Vector3.new(2, 2, 2)
+	Part.Parent = Viewport
+end
+
+local function ShowViewportWindow()
+	if not Spinner.Show then
+		return
 	end

-    PE()
+	Spinner.Show = ImGui.Begin("Viewport", Spinner.Show)
+
+	Spinner.Speed = ImGui.SliderFloat("speed", Spinner.Speed, 0.0, 5.0)
+	ImGui.ColorEdit3("color", Spinner.Color)
+
+	local Frame = ImGui.Embed("viewport", ImVec2(-1, 220), EmbedFlags.None, CreateSpinnerViewport)
+
+	Spinner.Angle += Spinner.Speed * IO.DeltaTime
+
+	local Part = Frame.ViewportFrame.Spinner
+	Part.CFrame = CFrame.Angles(0.4, Spinner.Angle, 0)
+	Part.Color = Color3.new(Spinner.Color.x, Spinner.Color.y, Spinner.Color.z)
+
+	ImGui.End()
+end
+
+RunService.Stepped:Connect(function()
+	ProfileBegin("ImGui frame")
+	ImGui_ImplRoblox.NewFrame()
+
+	ProfileBegin("ImGui.NewFrame")
+	ImGui.NewFrame()
+	ProfileEnd()
+
+	ProfileBegin("ImGui UI")
+	ImGui.DockSpaceOverViewport(0, nil, ImGuiDockNodeFlags.PassthruCentralNode)
+
+	if State.ShowDemoWindow then
+		-- For reference: https://github.com/4DBug/imgui-luau/blob/master/imgui_demo.lua
+		ImGui.ShowDemoWindow()
+	end
+
+	ShowHelloWindow()
+	ShowAnotherWindow()
 	ShowDecalViewer()
+	ShowViewportWindow()
+	ProfileEnd()

-    if show_viewport_window then
-        show_viewport_window = ImGui.Begin("Viewport", show_viewport_window)
-        spin_speed = ImGui.SliderFloat("speed", spin_speed, 0.0, 5.0)
-        ImGui.ColorEdit3("color", part_color)
-        local frame = ImGui.Embed("viewport", G.ImVec2(-1, 220), G.ImGuiEmbedFlags.None, function(f)
-            -- runs once
-            local vpf = Instance.new("ViewportFrame")
-            vpf.Size = UDim2.fromScale(1, 1)
-            vpf.BackgroundTransparency = 1
-            vpf.Parent = f
-            local cam = Instance.new("Camera")
-            cam.CFrame = CFrame.lookAt(Vector3.new(0, 2, 6), Vector3.new(0, 0, 0))
-            cam.Parent = vpf
-            vpf.CurrentCamera = cam
-            local part = Instance.new("Part")
-            part.Name = "Spinner"
-            part.Size = Vector3.new(2, 2, 2)
-            part.Parent = vpf
-        end)
-        -- every frame: edit what was created once
-        spin_angle += spin_speed * io.DeltaTime
-        local part = frame.ViewportFrame.Spinner
-        part.CFrame = CFrame.Angles(0.4, spin_angle, 0)
-        part.Color = Color3.new(part_color.x, part_color.y, part_color.z)
-        ImGui.Text("Frames created: 1 (same Frame every frame)")
-        ImGui.End()
-    end
+	ProfileBegin("ImGui.Render")
+	ImGui.EndFrame()
+	ImGui.Render()
+	ProfileEnd()

-    P("ImGui.Render"); ImGui.EndFrame(); ImGui.Render(); PE()
 	ImGui_ImplRoblox.RenderDrawData(ImGui.GetDrawData())
-    PE()
+	ProfileEnd()
 end)
@@ -4,6 +4,63 @@
 -- 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

@@ -13,7 +70,13 @@ 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 = {
@@ -44,12 +107,17 @@ local STBRP__PREV_LINK_TYPE = {
 --- @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
+        was_packed = 0 -- non-zero if valid packing
    }
 end

@@ -92,7 +160,7 @@ local function stbrp_context()

        active_head = nil,
        free_head   = nil,
-        extra       = {stbrp_node(), stbrp_node()}
+        extra       = {stbrp_node(), stbrp_node()} -- we allocate two extra nodes so optimal user-node-count is 'width' not 'width+2'
    }
 end

@@ -113,13 +181,14 @@ local function stbrp__findresult()
    }
 end

--------------------------
--------------------------
---
--- IMPLEMENTATION SECTION
---
---
+-------------------------------------------------------------------------------
+--
+--     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)
@@ -131,16 +200,49 @@ local function stbrp_setup_heuristic(context, heuristic)
    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
@@ -160,6 +262,7 @@ function stbrp_init_target(context, width, height, nodes, num_nodes)
    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]
@@ -168,6 +271,8 @@ function stbrp_init_target(context, width, height, nodes, num_nodes)
    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
@@ -181,7 +286,7 @@ local function stbrp__skyline_find_min_y(c, first, x0, width)

    STBRP_ASSERT(first.x <= x0)

-    STBRP_ASSERT(node.next.x > x0)
+    STBRP_ASSERT(node.next.x > x0) -- we ended up handling this in the caller for efficiency

    STBRP_ASSERT(node.x <= x0)

@@ -190,14 +295,19 @@ local function stbrp__skyline_find_min_y(c, first, x0, width)
    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
@@ -223,10 +333,12 @@ local function stbrp__skyline_find_best_pos(c, width, height)
    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
@@ -242,7 +354,8 @@ local function stbrp__skyline_find_best_pos(c, width, height)
    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
+        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
@@ -250,7 +363,9 @@ local function stbrp__skyline_find_best_pos(c, width, height)
                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
@@ -266,12 +381,30 @@ local function stbrp__skyline_find_best_pos(c, width, height)
        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
@@ -280,6 +413,7 @@ local function stbrp__skyline_find_best_pos(c, width, height)
            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
@@ -295,6 +429,7 @@ local function stbrp__skyline_find_best_pos(c, width, height)
                    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
@@ -320,19 +455,29 @@ end
 --- @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
@@ -341,6 +486,7 @@ local function stbrp__skyline_pack_rectangle(context, width, height)
    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
@@ -352,13 +498,17 @@ local function stbrp__skyline_pack_rectangle(context, width, height)
        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
@@ -390,6 +540,29 @@ 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
@@ -397,15 +570,17 @@ end
 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
+            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)
@@ -419,8 +594,10 @@ local function stbrp_pack_rects(context, rects, num_rects)
        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
@@ -428,6 +605,7 @@ local function stbrp_pack_rects(context, rects, num_rects)
        end
    end

+    -- return the all_rects_packed status
    return all_rects_packed
 end

@@ -441,3 +619,43 @@ return {
    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.
+-- ------------------------------------------------------------------------------
@@ -1,6 +1,221 @@
 --- 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)
@@ -13,6 +228,10 @@ 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
@@ -22,34 +241,35 @@ 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
+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
-STB_TEXTEDIT_K_LINEEND   = 0x200005 -- keyboard input to move cursor to end of line
-STB_TEXTEDIT_K_TEXTSTART = 0x200006 -- keyboard input to move cursor to start of text
-STB_TEXTEDIT_K_TEXTEND   = 0x200007 -- keyboard input to move cursor to end of text
+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
-STB_TEXTEDIT_K_WORDRIGHT = 0x20000D -- keyboard input to move cursor right one word
+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
+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
-local IMSTB_TEXTEDIT_UNDOCHARCOUNT  = 999
+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
 ---
@@ -72,6 +292,7 @@ local stb_text_redo
 --- @nodiscard
 local function StbUndoRecord()
    return {
+        -- private data
        where         = 1,
        insert_length = 0,
        delete_length = 0,
@@ -101,6 +322,7 @@ local function StbUndoState()
    end

    return {
+        -- private data
        undo_rec        = undo_rec,
        undo_char       = undo_char,

@@ -131,16 +353,34 @@ end
 --- @nodiscard
 function STB_TexteditState()
    return {
-        cursor = 0,
+        ---------------------
+        --
+        -- public data
+        --

-        select_start = 0,
+        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.

-        cursor_at_end_of_line = false,
+        ---------------------
+        --
+        -- private data
+        --
+        cursor_at_end_of_line = false, -- not implemented yet
        initialized           = false,
        has_preferred_x       = false,
        single_line           = false,
@@ -148,7 +388,7 @@ function STB_TexteditState()
        padding2 = 0,
        padding3 = 0,

-        preferred_x = 0.0,
+        preferred_x = 0.0, -- this determines where the cursor up/down tries to seek to along x

        undostate = StbUndoState()
    }
@@ -159,12 +399,20 @@ 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
+--- @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 baseline
--- @field ymax             float # height of row below 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
@@ -196,10 +444,15 @@ end
 ----------------------------------------
 ----------------------------------------
 ---
--- Implementation
+--- Implementation mode
 ---
 ---

+-------------------------------------------------------------------------------
+---
+---      Mouse input handling
+---
+
 local stb_text_locate_coord do

 -- only create once, reuse later
@@ -351,6 +604,7 @@ end
 ---
 ---

+-- forward declarations
 local stb_text_makeundo_insert
 local stb_text_makeundo_delete
 local stb_text_makeundo_replace
@@ -399,8 +653,8 @@ function stb_textedit_find_charpos(find, str, n, single_line)
    local z = STB_TEXTEDIT_STRINGLEN(str)
    local first

-    -- special case if it's at the end (may not be needed?)
    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
@@ -420,18 +674,18 @@ function stb_textedit_find_charpos(find, str, n, single_line)
        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 -- [IMGUI] Wrapping point handling
+        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 -- [IMGUI] special handling for last line
-            break
+        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 -- [IMGUI]
-            r.num_chars = 0
-            break
+        if i == z + 1 then -- [DEAR IMGUI]
+            r.num_chars = 0 -- [DEAR IMGUI]
+            break -- [DEAR IMGUI]
        end
    end

@@ -479,7 +733,7 @@ local function stb_textedit_delete(str, state, where, len)
    state.has_preferred_x = false
 end

-- delete the selection
+-- delete the section
 --- @param str   IMSTB_TEXTEDIT_STRING
 --- @param state STB_TexteditState
 local function stb_textedit_delete_selection(str, state)
@@ -498,7 +752,7 @@ local function stb_textedit_delete_selection(str, state)
    end
 end

-- canonicalize the selection so start <= 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
@@ -579,7 +833,7 @@ local function stb_textedit_paste_internal(str, state, text, len)
 end

 -- API key: process text input
-- [IMGUI] Added stb_textedit_text(), extracted out and called by stb_textedit_key() for backward compatibility.
+-- [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[]
@@ -732,7 +986,7 @@ function stb_textedit_key(str, state, key)
                break
            end

-            -- [IMGUI]
+            -- [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
@@ -929,8 +1183,8 @@ end
 -----------------------------------------------------
 ---
 --- Undo processing
--- OPTIMIZE: the undo/redo buffer should be circular
 ---
+--- @OPTIMIZE: the undo/redo buffer should be circular

 --- @param state StbUndoState
 local function stb_textedit_flush_redo(state)
@@ -950,7 +1204,7 @@ local function stb_textedit_discard_undo(state)
            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
+                    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
@@ -983,7 +1237,7 @@ local function stb_textedit_discard_redo(state)
        end

        -- now move all the redo records towards the end of the buffer; the first one is at 'redo_point'
-        -- [IMGUI]
+        -- [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)

@@ -1129,6 +1383,9 @@ function stb_text_redo(str, state)
    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
@@ -1137,6 +1394,7 @@ function stb_text_redo(str, state)
    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
@@ -1144,6 +1402,7 @@ function stb_text_redo(str, state)
            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
@@ -1153,6 +1412,7 @@ function stb_text_redo(str, state)
    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
@@ -1199,6 +1459,7 @@ function stb_text_makeundo_replace(str, state, where, old_length, new_length)
    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)
@@ -1222,7 +1483,7 @@ return {
    click = stb_textedit_click,
    drag = stb_textedit_drag,
    createundo = stb_text_createundo,
-    initialize_state = stb_textedit_clear_state,
+    initialize_state = stb_textedit_clear_state, -- API initialize

    text = stb_textedit_text,
    key = stb_textedit_key,
@@ -1236,3 +1497,43 @@ return {

    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.
+-------------------------------------------------------------------------------
@@ -1,6 +1,164 @@
 --- 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
@@ -21,7 +179,7 @@ local stbtt_FindGlyphIndex
 local STBTT_MAX_OVERSAMPLE = 8

 --- @enum STBTT_PLATFORM_ID
-local STBTT_PLATFORM_ID = {
+local STBTT_PLATFORM_ID = { -- platformID
    UNICODE   = 0,
    MAC       = 1,
    ISO       = 2,
@@ -29,7 +187,7 @@ local STBTT_PLATFORM_ID = {
 }

 --- @enum STBTT_MS_EID
-local STBTT_MS_EID = {
+local STBTT_MS_EID = { -- encodingID for STBTT_PLATFORM_ID_MICROSOFT
    SYMBOL       = 0,
    UNICODE_BMP  = 1,
    SHIFTJIS     = 2,
@@ -75,6 +233,7 @@ 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
@@ -93,6 +252,8 @@ local function stbtt__buf(initial_offset)
    }
 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
@@ -283,6 +444,7 @@ local function stbtt__new_active(e, off_x, start_point)
    return z
 end

+-- @TODO: don't expose this structure
 --- @class stbtt__bitmap
 --- @field w      int
 --- @field h      int
@@ -496,7 +658,7 @@ end
 -------------------------------------
 -------------------------------------
 ---
--- Accessors to parse data from file
+--- accessors to parse data from file
 ---
 ---

@@ -535,14 +697,16 @@ local function stbtt_tag4(p, c0, c1, c2, c3, offset) offset = offset or 0; retur
 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)
-    if stbtt_tag4(font, 49, 0, 0, 0) then return true end
-    if stbtt_tag(font, "typ1") then return true end
-    if stbtt_tag(font, "OTTO") then return true end
-    if stbtt_tag4(font, 0, 1, 0, 0) then return true end
-    if stbtt_tag(font, "true") then return true end
+    -- 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
@@ -556,11 +720,14 @@ local function stbtt__find_table(data, font_start, tag)
 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
@@ -598,23 +765,25 @@ local function stbtt_InitFont_internal(info, data, fontstart)
    info.fontstart = fontstart
    info.cff = stbtt__new_buf(nil, 0)

-    cmap = stbtt__find_table(data, fontstart, "cmap")
-    info.loca = stbtt__find_table(data, fontstart, "loca")
-    info.head = stbtt__find_table(data, fontstart, "head")
-    info.glyf = stbtt__find_table(data, fontstart, "glyf")
-    info.hhea = stbtt__find_table(data, fontstart, "hhea")
-    info.hmtx = stbtt__find_table(data, fontstart, "hmtx")
-    info.kern = stbtt__find_table(data, fontstart, "kern")
-    info.gpos = stbtt__find_table(data, fontstart, "GPOS")
+    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
@@ -623,14 +792,16 @@ local function stbtt_InitFont_internal(info, data, fontstart)
        info.fontdicts = stbtt__new_buf(nil, 0)
        info.fdselect = stbtt__new_buf(nil, 0)

-        info.cff = stbtt__new_buf(data, 64 * 1024 * 1024, cff) -- TODO: this should use size from table
+        -- @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))
+        stbtt__buf_seek(b, stbtt__buf_get8(b)) -- hdrsize

-        -- TODO: the name INDEX could list multiple fonts, but we just use the first one.
+        -- @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)
@@ -643,6 +814,7 @@ local function stbtt_InitFont_internal(info, data, fontstart)
        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
@@ -651,6 +823,7 @@ local function stbtt_InitFont_internal(info, data, fontstart)
        end

        if fdarrayoff[1] ~= 0 then
+            -- looks like a CID font
            if fdselectoff[1] == 0 then
                return false
            end
@@ -673,19 +846,26 @@ local function stbtt_InitFont_internal(info, data, fontstart)

    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
@@ -697,6 +877,11 @@ local function stbtt_InitFont_internal(info, data, fontstart)
    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)
@@ -704,7 +889,7 @@ function stbtt_FindGlyphIndex(info, unicode_codepoint)
    local index_map = info.index_map

    local format = ttUSHORT(data, index_map + 0)
-    if format == 0 then
+    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)
@@ -718,14 +903,15 @@ function stbtt_FindGlyphIndex(info, unicode_codepoint)
        end
        return 0
    elseif format == 2 then
-        STBTT_assert(false) -- TODO: high-byte mapping for japanese/chinese/korean
+        STBTT_assert(false) -- @TODO: high-byte mapping for japanese/chinese/korean
        return 0
-    elseif format == 4 then
+    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

@@ -733,10 +919,13 @@ function stbtt_FindGlyphIndex(info, unicode_codepoint)
            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)
@@ -768,8 +957,9 @@ function stbtt_FindGlyphIndex(info, unicode_codepoint)
        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)
+            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
@@ -785,10 +975,10 @@ function stbtt_FindGlyphIndex(info, unicode_codepoint)
                end
            end
        end
-        return 0
+        return 0 -- not found
    end

-    -- TODO:
+    -- @TODO
    STBTT_assert(false)
    return 0
 end
@@ -810,8 +1000,8 @@ end
 local function stbtt__GetGlyfOffset(info, glyph_index)
    STBTT_assert(info.cff.size == 0)

-    if glyph_index >= info.numGlyphs then return -1 end
-    if info.indexToLocFormat >= 2 then return -1 end
+    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
@@ -822,9 +1012,10 @@ local function stbtt__GetGlyfOffset(info, glyph_index)
        g2 = info.glyf + ttULONG(info.data, info.loca + glyph_index * 4 + 4)
    end

-    if g1 == g2 then return -1 else return g1 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
@@ -896,7 +1087,7 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)
        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
+        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
@@ -907,7 +1098,11 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)
        local next_move = 0
        local flagcount = 0

-        local off = m - n
+        -- 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
@@ -934,7 +1129,7 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)
            if bit32.band(flags, 2) ~= 0 then
                local dx = data[points]
                points = points + 1
-                if bit32.band(flags, 16) ~= 0 then
+                if bit32.band(flags, 16) ~= 0 then -- ???
                    x = x + dx
                else
                    x = x - dx
@@ -956,7 +1151,7 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)
            if bit32.band(flags, 4) ~= 0 then
                local dy = data[points]
                points = points + 1
-                if bit32.band(flags, 32) ~= 0 then
+                if bit32.band(flags, 32) ~= 0 then -- ???
                    y = y + dy
                else
                    y = y - dy
@@ -987,15 +1182,19 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)
                -- 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
+                        i = i + 1 -- we're using point i+1 as the starting point, so skip it
                    end
                else
                    sx = x
@@ -1007,8 +1206,8 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)
                next_move = 1 + ttUSHORT(data, endPtsOfContours + j * 2)
                j = j + 1
            else
-                if bit32.band(flags, 1) == 0 then
-                    if was_off then
+                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
@@ -1032,6 +1231,7 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)

        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
@@ -1047,8 +1247,8 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)
            flags = ttSHORT(data, comp) comp = comp + 2
            gidx = ttSHORT(data, comp) comp = comp + 2

-            if bit32.band(flags, 2) ~= 0 then
-                if bit32.band(flags, 1) ~= 0 then
+            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
@@ -1056,7 +1256,7 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)
                    mtx[6] = ttCHAR(data, comp) comp = comp + 1
                end
            else
-                -- TODO: handle matching point
+                -- @TODO handle matching point
                STBTT_assert(false)
            end

@@ -1083,11 +1283,14 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)
                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
@@ -1100,6 +1303,7 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)
                    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
@@ -1111,6 +1315,7 @@ local function stbtt__GetGlyphShapeTT(info, glyph_index)
                num_vertices = num_vertices + comp_num_vertices
            end

+            -- More components ?
            more = bit32.band(flags, bit32.lshift(1, 5))
        end
    end
@@ -1266,7 +1471,7 @@ local function stbtt__run_charstring(info, glyph_index, c)
        clear_stack = 1
        b0 = stbtt__buf_get8(b)

-        -- TODO: implement hinting
+        -- @TODO implement hinting
        if b0 == 0x13 or b0 == 0x14 then -- hintmask or cntrmask
            if in_header then
                maskbits = maskbits + trunc(sp / 2)  -- implicit "vstem"
@@ -1415,6 +1620,8 @@ local function stbtt__run_charstring(info, glyph_index, c)
        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]
@@ -1547,6 +1754,15 @@ function stbtt__GetGlyphInfoT2(info, glyph_index)
    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)
@@ -1557,6 +1773,9 @@ function stbtt_GetGlyphShape(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)
@@ -1574,6 +1793,12 @@ function stbtt_GetGlyphHMetrics(info, glyph_index)
    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)
@@ -1583,6 +1808,12 @@ function stbtt_GetFontVMetrics(info)
    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)
@@ -1593,10 +1824,12 @@ end
 ------------------------------------
 ------------------------------------
 ---
--- Antialiasing software rasterizer
+--- 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
@@ -1624,6 +1857,11 @@ function stbtt_GetGlyphBitmapBoxSubpixel(font, glyph, scale_x, scale_y, shift_x,
    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
@@ -1646,6 +1884,8 @@ end
 ---     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
@@ -1687,7 +1927,7 @@ local function stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x1, y1)
        -- 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)
+        scanline[x] = scanline[x] + e.direction * (y1 - y0) * (1 - ((x0 - x) + (x1 - x)) / 2) -- coverage = 1 - average x position
    end
 end

@@ -1725,6 +1965,7 @@ local function stbtt__fill_active_edges_new(scanline, scanline_fill, len, e, y_t

    while e do
        -- brute force every pixel
+
        -- compute intersection points with top & bottom
        STBTT_assert(e.ey >= y_top)

@@ -1768,8 +2009,8 @@ local function stbtt__fill_active_edges_new(scanline, scanline_fill, len, e, y_t
            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
-                    -- simple case, only spans one pixel
                    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)
@@ -1801,8 +2042,25 @@ local function stbtt__fill_active_edges_new(scanline, scanline_fill, len, e, y_t
                    -- 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?
+                    -- @TODO: maybe test against sy1 rather than y_bottom?
                    if y_crossing > y_bottom then
                        y_crossing = y_bottom
                    end
@@ -1824,6 +2082,16 @@ local function stbtt__fill_active_edges_new(scanline, scanline_fill, len, e, y_t
                        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
@@ -1843,7 +2111,27 @@ local function stbtt__fill_active_edges_new(scanline, scanline_fill, len, e, y_t
                    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
@@ -1887,6 +2175,7 @@ local function stbtt__fill_active_edges_new(scanline, scanline_fill, len, e, y_t
    end
 end

+-- directly AA rasterize edges w/o supersampling
 --- @param result     stbtt__bitmap
 --- @param e          stbtt__edge
 --- @param n          int
@@ -1914,28 +2203,33 @@ local function stbtt__rasterize_sorted_edges(result, e, n, vsubsample, off_x, of
        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
+                if prev then prev.next = next -- delete from list
                else          active   = next end
                curr.direction = 0
            else
-                prev = curr
+                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)
+                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
@@ -1943,6 +2237,7 @@ local function stbtt__rasterize_sorted_edges(result, e, n, vsubsample, off_x, of
            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
@@ -1961,10 +2256,11 @@ local function stbtt__rasterize_sorted_edges(result, e, n, vsubsample, off_x, of
            end
        end

+        -- advance all the edges
        step = active
        while step do
-            step.fx = step.fx + step.fdx
-            step = step.next
+            step.fx = step.fx + step.fdx -- advance to position for current scanline
+            step = step.next -- advance through list
        end

        y = y + 1
@@ -1999,6 +2295,7 @@ end
 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
@@ -2066,8 +2363,7 @@ local function stbtt__add_point(points, n, x, y)
    points[n + 1].y = y
 end

-- tessellate until threshold p is happy...
-- TODO: warped to compensate for non-linear stretching
+-- 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
@@ -2116,7 +2412,7 @@ end
 --- @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
+    -- @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
@@ -2159,6 +2455,7 @@ local function stbtt__tesselate_cubic(points, num_points, x0, y0, x1, y1, x2, y2
    return num_points
 end

+-- returns number of contours
 --- @param vertices          stbtt_vertex[]
 --- @param num_verts         int
 --- @param objspace_flatness float
@@ -2235,6 +2532,7 @@ local function stbtt_FlattenCurves(vertices, num_verts, objspace_flatness)
    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[]
@@ -2258,6 +2556,11 @@ local function stbtt_Rasterize(result, flatness_in_pixels, vertices, num_verts,
    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
@@ -2286,7 +2589,7 @@ end
 -----------------
 -----------------
 ---
--- Bitmap baking
+--- bitmap baking
 ---
 ---

@@ -2298,7 +2601,7 @@ end
 ---------------------------
 ---------------------------
 ---
--- Bitmap baking / packing
+--- bitmap baking / packing
 ---
 ---

@@ -2380,9 +2683,16 @@ 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
@@ -2415,7 +2725,7 @@ end
 -------------------
 -------------------
 ---
--- SDF computation
+--- sdf computation
 ---
 ---

@@ -2441,10 +2751,20 @@ end
 ---     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
@@ -0,0 +1,107 @@
+#!/usr/bin/env python3
+# Minifies a Lua/Luau file: drops comments, indentation, blank lines and spaces that don't separate tokens.
+# Kept: strings (verbatim), "--!" directive lines (--!optimize, --!native, ...), @native attributes, and one newline
+# wherever the source had one (so no ambiguous-call issues, and error line numbers stay roughly meaningful).
+#   python3 tools/minify.py IN OUT          # write minified IN to OUT
+#   python3 tools/minify.py --same-code F.. # check F.. have the same code tokens as `git show HEAD:F` (comment-only edits)
+#   python3 tools/minify.py --same-code-as OLD NEW  # same check between two files
+#   python3 tools/minify.py --test          # self-check
+import re, subprocess, sys
+from functools import lru_cache
+
+TOKEN = re.compile(r"""
+  (?P<ws>[ \t\r\n\f\v]+)
+| (?P<lcom>--\[(?P<ceq>=*)\[.*?\](?P=ceq)\])
+| (?P<com>--[^\n]*)
+| (?P<lstr>\[(?P<seq>=*)\[.*?\](?P=seq)\])
+| (?P<str>"(?:\\.|\\\n|[^"\\\n])*"|'(?:\\.|\\\n|[^'\\\n])*'|`(?:\\.|\\\n|[^`\\])*`)
+| (?P<num>0[xX][0-9a-fA-F_]*(?:\.[0-9a-fA-F_]*)?(?:[pP][+-]?\d+)?[uUlLi]*|0[bB][01_]+|(?:\d[\d_]*(?:\.[\d_]*)?|\.\d[\d_]*)(?:[eE][+-]?\d+)?[uUlLi]*)
+| (?P<name>@?[A-Za-z_]\w*)
+| (?P<op>\.\.\.|\.\.=|//=|\.\.|==|~=|<=|>=|//|::|->|[-+*/%^]=|.)
+""", re.S | re.X)
+
+def tokenize(src):
+    """[(kind, text, newline_before)]; comments/whitespace folded into newline_before ("--!" lines kept as 'dir')."""
+    out, nl, pos = [], False, 0
+    while pos < len(src):
+        m = TOKEN.match(src, pos)
+        kind, text = m.lastgroup, m.group(0)
+        if kind in ("ceq", "seq"): kind = "lcom" if text.startswith("--") else "lstr"
+        pos = m.end()
+        if kind == "ws" or kind == "lcom" or (kind == "com" and not text.startswith("--!")):
+            nl = nl or "\n" in text
+            continue
+        if kind == "com": kind = "dir"
+        if kind == "lstr" or kind == "str": kind = "str"
+        out.append((kind, text, nl))
+        nl = False
+    return out
+
+@lru_cache(maxsize=None)
+def glue_ok(a, b):
+    """True if `a..b` with no space still tokenizes as exactly a, b."""
+    if re.match(r"\w", a[-1]) and re.match(r"\w", b[0]): return False  # real lexers read `0then`/`x1` as one token
+    return [t for _, t, _ in tokenize(a + b)] == [a, b]
+
+def minify(src):
+    toks, out = tokenize(src), []
+    prev = None
+    for kind, text, nl in toks:
+        if prev is not None:
+            if nl or prev[0] == "dir" or kind == "dir": out.append("\n")
+            elif kind == "str" or prev[0] == "str":  # strings are self-delimiting; only `[` + `[[` would fuse
+                if kind == "str" and text[0] == "[" and prev[1].endswith("["): out.append(" ")
+            elif not glue_ok(prev[1], text):
+                out.append(" ")
+        out.append(text)
+        prev = (kind, text)
+    return "".join(out) + "\n"
+
+def code(src):
+    return [(k, t) for k, t, _ in tokenize(src)]
+
+def test():
+    cases = {
+        "local a = 1 -- c\nlocal b = a - -1\n": "local a=1\nlocal b=a- -1\n",
+        "x = 1 .. 2": "x=1 ..2\n",
+        "x = t[ [[s]] ]": "x=t[ [[s]]]\n",
+        "x = t[ [==[s]==] ]": "x=t[ [==[s]==]]\n",
+        "--!optimize 2\n--[[ long\ncomment ]] local s = 'a -- b' .. \"c\\\"d\"": "--!optimize 2\nlocal s='a -- b'..\"c\\\"d\"\n",
+        "@native\nfunction f(...) return ... end": "@native\nfunction f(...)return...end\n",
+        "a = b == c and d ~= e or f <= g": "a=b==c and d~=e or f<=g\n",
+        "x = 0x10 + 1e-5 + .5": "x=0x10+1e-5+.5\n",
+        "f(a)\n\n\n(g)(b)": "f(a)\n(g)(b)\n",
+        "s = [[a\n-- not a comment\n]]": "s=[[a\n-- not a comment\n]]\n",
+        "x = a / / b": "x=a/ /b\n",
+        "x = a . . b": "x=a. .b\n",
+        "if a == 0 then return 1 end": "if a==0 then return 1 end\n",
+        "x = 1 .. y": "x=1 ..y\n",
+    }
+    for src, want in cases.items():
+        got = minify(src)
+        assert got == want, (src, got, want)
+        assert code(minify(src)) == code(src), src
+    print("minify OK")
+
+if __name__ == "__main__":
+    if sys.argv[1] == "--test":
+        test()
+    elif sys.argv[1] in ("--same-code", "--same-code-as"):
+        bad = 0
+        pairs = [(sys.argv[2], sys.argv[3])] if sys.argv[1] == "--same-code-as" else [(None, f) for f in sys.argv[2:]]
+        for ref, f in pairs:
+            old = open(ref).read() if ref else subprocess.run(["git", "show", "HEAD:" + f], capture_output=True, text=True, check=True).stdout
+            a, b = code(old), code(open(f).read())
+            if a != b:
+                bad += 1
+                i = next((i for i, (x, y) in enumerate(zip(a, b)) if x != y), min(len(a), len(b)))
+                print("%s: CODE CHANGED at token %d: %r -> %r" % (f, i, a[i:i + 6], b[i:i + 6]))
+            else:
+                print("%s: same code" % f)
+        sys.exit(1 if bad else 0)
+    else:
+        src = open(sys.argv[1], encoding="utf-8").read()
+        dst = minify(src)
+        assert code(dst) == code(src), "minify changed code tokens"
+        open(sys.argv[2], "w", encoding="utf-8").write(dst)
+        print("wrote %s (%d -> %d bytes, %.0f%%)" % (sys.argv[2], len(src.encode()), len(dst.encode()), 100.0 * len(dst) / len(src)))
@@ -16,6 +16,8 @@ G = "game, workspace, Instance, Enum, Vector2, Vector3, UDim2, Color3, Content,

 def build_run(args, flags):
    subprocess.run([sys.executable, os.path.join(ROOT, "tools", "bundle.py"), TMP] + (["--no-demo"] if os.environ.get("NO_DEMO") else []), check=True, stdout=subprocess.DEVNULL)
+    if os.environ.get("MINIFY"):  # test the minified bundle instead (error line numbers won't map back to sources)
+        subprocess.run([sys.executable, os.path.join(ROOT, "tools", "minify.py"), os.path.join(TMP, "ImGui.luau"), os.path.join(TMP, "ImGui.luau")], check=True, stdout=subprocess.DEVNULL)
    out = ["--" if args.roblox else "--!native", "--!optimize 2", flags, "local SOURCE_FNS = {}"]
    def add(key, path):
        s = "\n".join(l for l in open(path).read().split("\n") if not l.startswith("--!"))
@@ -0,0 +1,68 @@
+-- Docked windows (floating split node) stop being submitted: the host lingers one frame, its bodies must be filled
+-- with the windows' bg colour (node.LastBgColor), not white, and everything must be gone within a few frames.
+local ReplicatedStorage = game:GetService("ReplicatedStorage")
+local RunService = game:GetService("RunService")
+local G = require(ReplicatedStorage:WaitForChild("ImGui"))
+local ImGui, ImVec2 = G.ImGui, G.ImVec2
+ImGui.CreateContext()
+local io = ImGui.GetIO()
+io.ConfigFlags = bit32.bor(io.ConfigFlags, G.ImGuiConfigFlags.DockingEnable)
+G.ImGui_ImplRoblox.Init()
+local frame, closed_at, done = 0, 31, false
+RunService.Stepped:Connect(function()
+    if done then return end
+    frame += 1
+    G.ImGui_ImplRoblox.NewFrame()
+    ImGui.NewFrame()
+    if frame == 2 then
+        local id = ImGui.GetID("floating")
+        ImGui.DockBuilderRemoveNode(id)
+        ImGui.DockBuilderAddNode(id, 0)
+        ImGui.DockBuilderSetNodePos(id, ImVec2(100, 100))
+        ImGui.DockBuilderSetNodeSize(id, ImVec2(600, 400))
+        local left, right = ImGui.DockBuilderSplitNode(id, G.ImGuiDir.Left, 0.5)
+        ImGui.DockBuilderDockWindow("A", left)
+        ImGui.DockBuilderDockWindow("B", right)
+        ImGui.DockBuilderFinish(id)
+    end
+    if frame < closed_at then
+        for _, n in { "A", "B" } do
+            if ImGui.Begin(n) then ImGui.Text("window " .. n) end
+            ImGui.End()
+        end
+    end
+    if frame == closed_at - 1 then
+        local a, b = ImGui.FindWindowByName("A"), ImGui.FindWindowByName("B")
+        assert(a.DockNode and b.DockNode and a.DockNode ~= b.DockNode and a.DockNode.HostWindow, "A, B docked side by side")
+    end
+    ImGui.Render()
+    local dd = ImGui.GetDrawData()
+    if frame >= closed_at then
+        for _, dl in dd.CmdLists:iter() do
+            -- white vertices spanning a big area = a white body fill (white text glyphs are small)
+            local vb, x0, y0, x1, y1 = dl.VtxBuffer.Buf, math.huge, math.huge, -math.huge, -math.huge
+            for _, pcmd in dl.CmdBuffer:iter() do
+                for i = pcmd.IdxOffset + 1, pcmd.IdxOffset + pcmd.ElemCount do
+                    local o = (pcmd.VtxOffset + dl.IdxBuffer.Data[i] - 1) * G.VTX_STRIDE
+                    if buffer.readu32(vb, o + 32) == 0xFFFFFFFF then
+                        local x, y = buffer.readf64(vb, o), buffer.readf64(vb, o + 8)
+                        x0, y0, x1, y1 = math.min(x0, x), math.min(y0, y), math.max(x1, x), math.max(y1, y)
+                    end
+                end
+            end
+            assert(not (x1 - x0 > 100 and y1 - y0 > 100), "white fill on frame " .. frame)
+        end
+        if dd.TotalVtxCount == 0 then
+            G.ImGui_ImplRoblox.RenderDrawData(dd)
+            for _, set in io.BackendPlatformUserData.Layers do
+                for kind = 1, 3 do assert(not (set[kind] and set[kind].Visible), "backend layer still visible after close") end
+            end
+            print("DOCK CLOSE OK after", frame - closed_at + 1, "frames")
+            done = true
+            return
+        else
+            assert(frame < closed_at + 3, "docked windows still drawn " .. (frame - closed_at + 1) .. " frames after close")
+        end
+    end
+    G.ImGui_ImplRoblox.RenderDrawData(dd)
+end)
@@ -0,0 +1,57 @@
+-- Regressions vs upstream: clipboard paste filter (InputTextEx), ImParseFormatTrimDecorations (Ctrl+click temp input), ShrinkWidths tie order
+local G = require(game:GetService("ReplicatedStorage"):WaitForChild("ImGui"))
+local ImGui, ImVec2 = G.ImGui, G.ImVec2
+ImGui.CreateContext(); G.ImGui_ImplRoblox.Init()
+local io = ImGui.GetIO()
+local failed = {}
+local function check(ok, msg) if not ok then table.insert(failed, msg); print("FAIL " .. msg) end end
+
+-- ShrinkWidths: equal widths sort by Index descending (upstream ShrinkWidthItemComparer), so the rounding remainder goes to the highest Index first
+local items = {}
+for i = 1, 4 do local it = G.ImGuiShrinkWidthItem(); it.Index = i - 1; it.Width = 100; it.InitialWidth = 100; items[i] = it end
+ImGui.ShrinkWidths(items, 1, 4, 2.0, 10.0)
+local w = {}
+for _, it in items do w[it.Index] = it.Width end
+check(w[3] == 100 and w[2] == 100 and w[1] == 99 and w[0] == 99, ("ShrinkWidths widths %s %s %s %s"):format(w[0], w[1], w[2], w[3]))
+
+local function edit_text()
+    local st = ImGui.GetCurrentContext().InputTextState
+    return G.ImGui._ByteArrayToString(st.TextA.Data, 1, st.TextLen + 1)
+end
+local buf = ImGui.NewTextBuffer("", 64)
+local f, sf, di = 0, 45.0, 50
+local rects = {}
+local function rect() local a, b = ImGui.GetItemRectMin(), ImGui.GetItemRectMax(); return { ImVec2(a.x, a.y), ImVec2(b.x, b.y) } end -- copies: GetItemRectMin() returns the live LastItemData.Rect.Min
+local function click(name, ctrl)
+    local r = rects[name]
+    io:AddMousePosEvent((r[1].x + r[2].x) / 2, (r[1].y + r[2].y) / 2)
+    if ctrl then io:AddKeyEvent(G.ImGuiMod_Ctrl, true) end
+    io:AddMouseButtonEvent(0, true)
+end
+local function release() io:AddMouseButtonEvent(0, false); io:AddKeyEvent(G.ImGuiMod_Ctrl, false) end
+local function key(k) io:AddKeyEvent(k, true); io:AddKeyEvent(k, false) end
+
+game:GetService("RunService").Stepped:Connect(function()
+    f += 1
+    G.ImGui_ImplRoblox.NewFrame()
+    if f == 3 then click("t") elseif f == 4 then release() end
+    -- clipboard: tab is filtered out (single line, no AllowTabInput), é is 2 bytes
+    if f == 6 then ImGui.SetClipboardText("ab\tc\u{e9}"); io:AddKeyEvent(G.ImGuiMod_Ctrl, true); io:AddKeyEvent(G.ImGuiKey.V, true) end
+    if f == 7 then io:AddKeyEvent(G.ImGuiKey.V, false); io:AddKeyEvent(G.ImGuiMod_Ctrl, false) end
+    if f == 9 then key(G.ImGuiKey.Escape) end
+    if f == 11 then click("s", true) elseif f == 12 then release() end
+    if f == 14 then key(G.ImGuiKey.Escape) end
+    if f == 16 then click("d", true) elseif f == 17 then release() end
+    ImGui.NewFrame()
+    ImGui.SetNextWindowPos(ImVec2(10, 10)); ImGui.SetNextWindowSize(ImVec2(300, 200))
+    ImGui.Begin("T")
+    ImGui.InputText("##t", buf, 64); rects.t = rect()
+    sf = ImGui.SliderFloat("##s", sf, 0.0, 100.0, "%.0f deg"); rects.s = rect()
+    di = ImGui.DragInt("##d", di, 1, 0, 100, "%d%%"); rects.d = rect()
+    ImGui.End()
+    ImGui.Render(); G.ImGui_ImplRoblox.RenderDrawData(ImGui.GetDrawData())
+    if f == 8 then check(edit_text() == "abc\u{e9}", "paste: '" .. edit_text() .. "'") end
+    if f == 13 then check(edit_text() == "45", "SliderFloat temp input: '" .. edit_text() .. "'") end
+    if f == 18 then check(edit_text() == "50", "DragInt temp input: '" .. edit_text() .. "'") end
+    if f == 20 and #failed == 0 then print("FIXES OK") end
+end)
@@ -2,7 +2,7 @@
 local G = require(game:GetService("ReplicatedStorage"):WaitForChild("ImGui"))
 local ImGui, ImVec2 = G.ImGui, G.ImVec2
 local UIS = game:GetService("UserInputService")
-ImGui.CreateContext(); G.ImGui_ImplRoblox.Init()
+ImGui.CreateContext(); G.ImGui_ImplRoblox.Init(); G.ImGui_ImplRoblox.SetTextProxy(true)
 local io = ImGui.GetIO()
 local buf = ImGui.NewTextBuffer("", 64)
 local proxy
@@ -1,6 +1,6 @@
 [package]
-name = "bug/imgui-luau"
-version = "0.1.0"
+name = "4dbug/imgui-luau"
+version = "0.1.4"
 registry = "https://github.com/UpliftGames/wally-index"
 realm = "shared"
 license = "MIT"
Author	SHA1	Message	Date
4DBug	ce82582e37	0.1.4 Build & Release / build (push) Waiting to run Details	2026-10-14 10:32:10 -05:00
4DBug	090525076f	InputText: fix clipboard paste (filter was inverted, then off-by-one in the filtered buffer); ImParseFormatTrimDecorations: return [start, end) like upstream (Ctrl+click temp input showed decorations / crashed on "%d%%"); ShrinkWidths: tie order by Index descending like upstream; t_fixes test	2026-10-14 10:32:10 -05:00
4DBug	95fdf94912	Comments: mirror upstream imgui.cpp/.h, imgui_internal.h, widgets/draw/tables/demo and imstb_* comments (comment-only, code tokens unchanged) Build & Release / build (push) Waiting to run Details	2026-10-14 10:23:55 -05:00
4DBug	e502866075	CI: minified builds (ImGui.min.luau, ImGui-nodemo.min.luau, imgui_love.min.lua, imgui_love-nodemo.min.lua) via tools/minify.py; checks + release assets; run.py MINIFY=1	2026-10-14 10:23:55 -05:00
4DBug	1431d2e19d	0.1.3 Build & Release / build (push) Waiting to run Details	2026-10-14 06:26:28 -05:00
4DBug	7eb7d5fcbb	Docking: set node.LastBgColor (closing dock hosts drew white bodies), host skips own bg, fix SetNextWindowBgAlpha; Roblox backend: frames skipped by the render rate cap are drawn later (UI could freeze when the app stopped rendering); t_dock_close test	2026-10-14 06:26:28 -05:00
4DBug	2558c30d32	0.1.2 Build & Release / build (push) Canceled after 0s Details	2026-10-09 02:24:21 -05:00
4DBug	e228ed8638	Roblox backend: text proxy is opt-in (SetTextProxy), remove SetTextProxyDebug; new example main.client.luau	2026-10-09 02:22:30 -05:00
4DBug	28dc08e043	README: move 'How it works' below Getting Started Build & Release / build (push) Canceled after 0s Details	2026-10-08 20:57:31 -05:00
4DBug	f63a37f07d	README: Wally package link; 0.1.1 Build & Release / build (push) Canceled after 0s Details	2026-10-08 20:54:31 -05:00
4DBug	08356b4f1f	Wally: scope 4dbug (must match the GitHub account) Build & Release / build (push) Canceled after 0s Details	2026-10-08 20:52:52 -05:00