Files
imgui-luau/backends/imgui_impl_roblox.lua
T
4DBug 81c5ad9e43 Roblox backend: hidden TextBox proxy for text input
A single off-screen TextBox holds focus while an imgui text field is active, so the OS
delivers typing (any layout/unicode), paste and copy/cut. Its text mirrors imgui selection
(fully selected) so Ctrl+C/X copy exactly that; deletions apply as an imgui Backspace;
Ctrl is released around pasted characters. Focus is captured after the click is released,
kept on clicks inside imgui, ends on clicks outside. KeyCode text kept as fallback.
SetTextProxyDebug for logging.
2026-10-08 19:31:22 -05:00

1330 lines
64 KiB
Lua

--- ImGui Backend for Roblox
--- - Renderer: exact software rasterizer (1:1 with imgui's triangles) into 256x256 EditableImage tiles at native
--- screen resolution; only tiles whose content changed are redrawn/uploaded (see RenderDrawData).
--- - Platform: UserInputService
--- - Files: an in-memory file system (VFS), pre-filled with the fonts from imgui_impl_roblox_fonts.lua
--- Requires "Allow Mesh / Image APIs" (EditableImage) in game settings.
local UserInputService = game:GetService("UserInputService")
local Players = game:GetService("Players")
local AssetService = game:GetService("AssetService")
local floor, ceil, min, max = math.floor, math.ceil, math.min, math.max
local readu8, readu32, writeu32, readstring = buffer.readu8, buffer.readu32, buffer.writeu32, buffer.readstring
local readf64 = buffer.readf64
local band, rshift = bit32.band, bit32.rshift
local ImGui_ImplRoblox_GetBackendData
local ImGui_ImplRoblox_UpdateTexture
local ImGui_ImplRoblox_RenderDrawData
local ImGui_ImplRoblox_Shutdown
local KEY_MAP = {} -- Enum.KeyCode -> ImGuiKey
do
local names = {
Return = "Enter", Escape = "Escape", Backspace = "Backspace", Tab = "Tab", Space = "Space", KeypadEnter = "KeypadEnter",
Up = "UpArrow", Down = "DownArrow", Left = "LeftArrow", Right = "RightArrow",
Home = "Home", End = "End", PageUp = "PageUp", PageDown = "PageDown", Insert = "Insert", Delete = "Delete",
LeftControl = "LeftCtrl", RightControl = "RightCtrl", LeftShift = "LeftShift", RightShift = "RightShift",
LeftAlt = "LeftAlt", RightAlt = "RightAlt", LeftSuper = "LeftSuper", RightSuper = "RightSuper",
Quote = "Apostrophe", Comma = "Comma", Minus = "Minus", Period = "Period", Slash = "Slash", Semicolon = "Semicolon",
Equals = "Equal", LeftBracket = "LeftBracket", BackSlash = "Backslash", RightBracket = "RightBracket", Backquote = "GraveAccent",
CapsLock = "CapsLock",
KeypadPeriod = "KeypadDecimal", KeypadDivide = "KeypadDivide", KeypadMultiply = "KeypadMultiply",
KeypadMinus = "KeypadSubtract", KeypadPlus = "KeypadAdd", KeypadEquals = "KeypadEqual",
}
local digits = { "Zero", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine" }
for i = 0, 9 do
names[digits[i + 1]] = "K" .. i
names["Keypad" .. digits[i + 1]] = "Keypad" .. i
end
for i = 1, 12 do names["F" .. i] = "F" .. i end
for c in ("ABCDEFGHIJKLMNOPQRSTUVWXYZ"):gmatch(".") do names[c] = c end
for rbx_name, imgui_name in pairs(names) do
KEY_MAP[Enum.KeyCode[rbx_name]] = ImGuiKey[imgui_name]
end
end
-- Roblox has no "text input" event, so characters come from KeyCode.Value (ASCII for printable keys) + a US layout shift table.
local SHIFTED = {
["1"] = "!", ["2"] = "@", ["3"] = "#", ["4"] = "$", ["5"] = "%", ["6"] = "^", ["7"] = "&", ["8"] = "*", ["9"] = "(", ["0"] = ")",
["-"] = "_", ["="] = "+", ["["] = "{", ["]"] = "}", ["\\"] = "|", [";"] = ":", ["'"] = "\"", [","] = "<", ["."] = ">", ["/"] = "?", ["`"] = "~",
}
local MOUSE_BUTTONS = {
[Enum.UserInputType.MouseButton1] = 0, -- ImGuiMouseButton.Left
[Enum.UserInputType.MouseButton2] = 1, -- ImGuiMouseButton.Right
[Enum.UserInputType.MouseButton3] = 2, -- ImGuiMouseButton.Middle
}
--- @return boolean ctrl, boolean shift, boolean alt
local function ImGui_ImplRoblox_UpdateKeyModifiers()
local io = ImGui.GetIO()
local K = Enum.KeyCode
local ctrl = UserInputService:IsKeyDown(K.LeftControl) or UserInputService:IsKeyDown(K.RightControl)
local shift = UserInputService:IsKeyDown(K.LeftShift) or UserInputService:IsKeyDown(K.RightShift)
local alt = UserInputService:IsKeyDown(K.LeftAlt) or UserInputService:IsKeyDown(K.RightAlt)
io:AddKeyEvent(ImGuiMod_Ctrl, ctrl)
io:AddKeyEvent(ImGuiMod_Shift, shift)
io:AddKeyEvent(ImGuiMod_Alt, alt)
io:AddKeyEvent(ImGuiMod_Super, UserInputService:IsKeyDown(K.LeftSuper) or UserInputService:IsKeyDown(K.RightSuper))
return ctrl, shift, alt
end
--- @return table?
function ImGui_ImplRoblox_GetBackendData()
return ImGui.GetCurrentContext() and ImGui.GetIO().BackendPlatformUserData or nil
end
local function ImGui_ImplRoblox_UpdateMonitors(w, h)
local platform_io = ImGui.GetPlatformIO()
platform_io.Monitors:resize(0)
local imgui_monitor = ImGuiPlatformMonitor()
ImVec2_Copy(imgui_monitor.MainSize, ImVec2(w, h))
ImVec2_Copy(imgui_monitor.WorkSize, ImVec2(w, h))
platform_io.Monitors:push_back(imgui_monitor)
end
---------------------------------------------------------
-- PLATFORM DATA & CALLBACKS
---------------------------------------------------------
-- Games can't touch the OS clipboard, so copy/paste only works inside ImGui
local clipboard = ""
local function ImGui_ImplRoblox_PlatformSetClipboardText(ctx, text) clipboard = text end
local proxy_focused = false
local function ImGui_ImplRoblox_PlatformGetClipboardText(ctx) if proxy_focused then return "" end return clipboard end
---------------------------------------------------------
-- FILE SYSTEM (in-memory, Roblox has no file access)
---------------------------------------------------------
local VFS = {} -- path -> string of raw bytes
--- Registers a file so ImGui can load it, e.g. ImGui_ImplRoblox.AddFile("fonts/MyFont.ttf", bytes)
--- then io.Fonts:AddFontFromFileTTF("fonts/MyFont.ttf", 16)
local function ImGui_ImplRoblox_AddFile(path, bytes) VFS[path] = bytes end
for path, hex in pairs(IM_INCLUDE("imgui_impl_roblox_fonts.lua")) do
VFS[path] = hex:gsub("%s", ""):gsub("%x%x", function(h) return string.char(tonumber(h, 16)) end)
end
function ImStd.ImFileOpen(filename, mode)
local data = VFS[filename]
return data and { Data = data, Pos = 0 } or nil
end
function ImStd.ImFileClose(f) end
function ImStd.ImFileGetSize(f) return #f.Data end
function ImStd.ImFileRead(f, data, count)
local s, pos = f.Data, f.Pos
count = min(count, #s - pos)
for i = 1, count do data[i] = string.byte(s, pos + i) end
f.Pos = pos + count
return count
end
function ImStd.ImFileLoadToMemory(filename, mode)
local f = ImStd.ImFileOpen(filename, mode)
if not f or #f.Data == 0 then return end
local file_data = {}
local size = ImStd.ImFileRead(f, file_data, #f.Data)
return file_data, size
end
---------------------------------------------------------
-- TEXTURE MANAGEMENT
---------------------------------------------------------
-- Copies a region of ImTextureData pixels (1-based byte table) into our RGBA8 buffer
local function CopyTexturePixels(tex, dst, x, y, w, h)
local bpp, tex_w = tex.BytesPerPixel, tex.Width
for row = 0, h - 1 do
local src, src_base = tex:GetPixelsAt(x, y + row)
local dst_off = ((y + row) * tex_w + x) * 4
if bpp == 4 then
for i = 0, w - 1 do
local s = src_base + i * 4
writeu32(dst, dst_off + i * 4, src[s] + src[s + 1] * 256 + src[s + 2] * 65536 + src[s + 3] * 16777216)
end
else -- Alpha8: white with alpha
for i = 0, w - 1 do
writeu32(dst, dst_off + i * 4, 16777215 + src[src_base + i] * 16777216)
end
end
end
end
function ImGui_ImplRoblox_UpdateTexture(tex)
local bd = ImGui_ImplRoblox_GetBackendData()
if tex.Status == ImTextureStatus.WantCreate then
local t = { Buffer = buffer.create(tex.Width * tex.Height * 4), Width = tex.Width, Height = tex.Height }
CopyTexturePixels(tex, t.Buffer, 0, 0, tex.Width, tex.Height)
bd.TextureCount = bd.TextureCount + 1
bd.Textures[bd.TextureCount] = t
tex.BackendUserData = bd.TextureCount
tex:SetTexID(bd.TextureCount)
tex:SetStatus(ImTextureStatus.OK)
elseif tex.Status == ImTextureStatus.WantUpdates then
local t = bd.Textures[tex.BackendUserData]
IM_ASSERT(t ~= nil)
for _, r in tex.Updates:iter() do
CopyTexturePixels(tex, t.Buffer, r.x, r.y, r.w, r.h)
end
tex:SetStatus(ImTextureStatus.OK)
elseif tex.Status == ImTextureStatus.WantDestroy then
if tex.BackendUserData then
bd.Textures[tex.BackendUserData] = nil
tex.BackendUserData = nil
end
tex:SetTexID(ImTextureID_Invalid)
tex:SetStatus(ImTextureStatus.Destroyed)
end
end
--- User texture from RGBA8 pixels (e.g. EditableImage:ReadPixelsBuffer()). Returns an ImTextureRef for
--- ImGui.Image / draw_list:AddImage. Ids are never reused, so cached tiles can't show a stale image.
function ImGui_ImplRoblox_CreateTexture(pixels, w, h)
local bd = ImGui_ImplRoblox_GetBackendData()
bd.TextureCount = bd.TextureCount + 1
bd.Textures[bd.TextureCount] = { Buffer = pixels, Width = w, Height = h }
return ImTextureRef(bd.TextureCount)
end
function ImGui_ImplRoblox_DestroyTexture(tex_ref)
ImGui_ImplRoblox_GetBackendData().Textures[tex_ref._TexID] = nil
end
---------------------------------------------------------
-- RENDERING (software rasterizer into tile buffers)
---------------------------------------------------------
-- Buffer layout: 4 bytes per pixel, R G B A, row-major, 0-based offsets. ImU32 colours are already R | G<<8 | B<<16 | A<<24.
-- Blending is non-premultiplied "over" with a transparent (alpha 0) background, so the game stays visible behind ImGui.
local buf, buf_w -- buffer/width of the tile being drawn
local TILE_SIZE -- Vector2, set below
-- Blends one pixel (r, g, b, a are 0..255). One u32 read/write, one division in the general case.
-- FillSpan below inlines the same math with per-span constants - keep the two in sync.
@native
local function BlendPixel(o, r, g, b, a)
if a >= 255 then
writeu32(buf, o, floor(r + 0.5) + floor(g + 0.5) * 256 + floor(b + 0.5) * 65536 + 4278190080)
return
end
if a <= 0 then return end
local d = readu32(buf, o)
local da = rshift(d, 24)
if da == 0 then
writeu32(buf, o, floor(r + 0.5) + floor(g + 0.5) * 256 + floor(b + 0.5) * 65536 + floor(a + 0.5) * 16777216)
return
end
local sa = a / 255
local dr, dg, db = band(d, 255), band(rshift(d, 8), 255), band(rshift(d, 16), 255)
if da == 255 then
local ns = 1 - sa
writeu32(buf, o, floor(r * sa + dr * ns + 0.5) + floor(g * sa + dg * ns + 0.5) * 256 + floor(b * sa + db * ns + 0.5) * 65536 + 4278190080)
else
local k = da * ((1 - sa) / 255)
local oa = sa + k
local inv = 1 / oa
writeu32(buf, o, floor((r * sa + dr * k) * inv + 0.5) + floor((g * sa + dg * k) * inv + 0.5) * 256
+ floor((b * sa + db * k) * inv + 0.5) * 65536 + floor(oa * 255 + 0.5) * 16777216)
end
end
-- Fills pixels [x0, x1) of row y with one colour
@native
local function FillSpan(y, x0, x1, r, g, b, a)
if a <= 0 then return end
local o0 = (y * buf_w + x0) * 4
local o1 = o0 + (x1 - x0 - 1) * 4
if a >= 255 then
local packed = floor(r + 0.5) + floor(g + 0.5) * 256 + floor(b + 0.5) * 65536 + 4278190080
for o = o0, o1, 4 do writeu32(buf, o, packed) end
return
end
local packed0 = floor(r + 0.5) + floor(g + 0.5) * 256 + floor(b + 0.5) * 65536 + floor(a + 0.5) * 16777216
local sa = a / 255
local ns = 1 - sa
local c1 = ns / 255
local rs, gs, bs = r * sa, g * sa, b * sa
local last_d, last_v = -1, 0 -- UI backgrounds are mostly flat: reuse the previous result for the same destination
for o = o0, o1, 4 do
local d = readu32(buf, o)
local da = rshift(d, 24)
if d == last_d then
writeu32(buf, o, last_v)
elseif da == 0 then
writeu32(buf, o, packed0)
else
last_d = d
local dr, dg, db = band(d, 255), band(rshift(d, 8), 255), band(rshift(d, 16), 255)
if da == 255 then
last_v = floor(rs + dr * ns + 0.5) + floor(gs + dg * ns + 0.5) * 256 + floor(bs + db * ns + 0.5) * 65536 + 4278190080
else
local k = da * c1
local oa = sa + k
local inv = 1 / oa
last_v = floor((rs + dr * k) * inv + 0.5) + floor((gs + dg * k) * inv + 0.5) * 256
+ floor((bs + db * k) * inv + 0.5) * 65536 + floor(oa * 255 + 0.5) * 16777216
end
writeu32(buf, o, last_v)
end
end
end
@native
local function UnpackColor(col)
return col % 256, floor(col / 256) % 256, floor(col / 65536) % 256, floor(col / 16777216) % 256
end
-- Nearest texel at (u, v) as r, g, b, a (0..255)
@native
local function SampleTexture(t, u, v)
local tw, th = t.Width, t.Height
local tx, ty = floor(u * tw), floor(v * th)
if tx < 0 then tx = 0 elseif tx >= tw then tx = tw - 1 end
if ty < 0 then ty = 0 elseif ty >= th then ty = th - 1 end
local o = (ty * tw + tx) * 4
local tb = t.Buffer
return readu8(tb, o), readu8(tb, o + 1), readu8(tb, o + 2), readu8(tb, o + 3)
end
-- Axis aligned, single colour quad (rects, glyphs, images). Pixel centers inside [x0, x1) x [y0, y1) are drawn.
@native
local function DrawRect(x0, y0, x1, y1, u0, v0, u1, v1, col, t, cx0, cy0, cx1, cy1)
local r, g, b, a = UnpackColor(col)
if a == 0 then return end
local px0, py0 = max(ceil(x0 - 0.5), cx0), max(ceil(y0 - 0.5), cy0)
local px1, py1 = min(ceil(x1 - 0.5), cx1), min(ceil(y1 - 0.5), cy1)
if px0 >= px1 or py0 >= py1 then return end
if not t or (u0 == u1 and v0 == v1) then
if t then
local tr, tg, tb, ta = SampleTexture(t, u0, v0)
r, g, b, a = r * tr / 255, g * tg / 255, b * tb / 255, a * ta / 255
end
if a <= 0 then return end
-- Rows of a flat rect usually blend over identical rows: when this row's destination equals the previous
-- row's (exact string compare), the result is identical too, so memcpy the previous row's result.
local len = (px1 - px0) * 4
local prev_dst, prev_o = nil, 0
for y = py0, py1 - 1 do
local o = (y * buf_w + px0) * 4
if a >= 255 then
if prev_dst then buffer.copy(buf, o, buf, prev_o, len) else FillSpan(y, px0, px1, r, g, b, a); prev_dst = true end
else
local dst = readstring(buf, o, len)
if dst == prev_dst then
buffer.copy(buf, o, buf, prev_o, len)
else
FillSpan(y, px0, px1, r, g, b, a)
prev_dst = dst
end
end
prev_o = o
end
return
end
local du, dv = (u1 - u0) / (x1 - x0), (v1 - v0) / (y1 - y0)
local tw, th, tbuf = t.Width, t.Height, t.Buffer
local r255, g255, b255, a255 = r / 255, g / 255, b / 255, a / 255
for y = py0, py1 - 1 do
local ty = floor((v0 + (y + 0.5 - y0) * dv) * th)
if ty < 0 then ty = 0 elseif ty >= th then ty = th - 1 end
local trow = ty * tw
local o = (y * buf_w + px0) * 4
for x = px0, px1 - 1 do
local tx = floor((u0 + (x + 0.5 - x0) * du) * tw)
if tx < 0 then tx = 0 elseif tx >= tw then tx = tw - 1 end
local to = (trow + tx) * 4
local ta = readu8(tbuf, to + 3)
if ta > 0 then
BlendPixel(o, readu8(tbuf, to) * r255, readu8(tbuf, to + 1) * g255, readu8(tbuf, to + 2) * b255, ta * a255)
end
o = o + 4
end
end
end
-- Generic triangle: per-vertex colour + uv, top-left fill rule, clipped to [cx0, cx1) x [cy0, cy1)
@native
local function DrawTriangle(vbuf, va, vb, vc, t, cx0, cy0, cx1, cy1, ox, oy)
local x0, y0 = readf64(vbuf, va) - ox, readf64(vbuf, va + 8) - oy
local x1, y1 = readf64(vbuf, vb) - ox, readf64(vbuf, vb + 8) - oy
local x2, y2 = readf64(vbuf, vc) - ox, readf64(vbuf, vc + 8) - oy
local area = (x1 - x0) * (y2 - y0) - (y1 - y0) * (x2 - x0)
if area == 0 then return end
if area < 0 then -- make the winding consistent so "inside" means all edge functions >= 0
vb, vc = vc, vb
x1, y1, x2, y2 = x2, y2, x1, y1
area = -area
end
local minx, maxx = max(floor(min(x0, x1, x2)), cx0), min(ceil(max(x0, x1, x2)), cx1 - 1)
local miny, maxy = max(floor(min(y0, y1, y2)), cy0), min(ceil(max(y0, y1, y2)), cy1 - 1)
if minx > maxx or miny > maxy then return end
-- Edge functions E(p) = A*px + B*py + C, w0 is opposite va, w1 opposite vb, w2 opposite vc
local A0, B0 = y1 - y2, x2 - x1; local C0 = -(A0 * x1 + B0 * y1)
local A1, B1 = y2 - y0, x0 - x2; local C1 = -(A1 * x2 + B1 * y2)
local A2, B2 = y0 - y1, x1 - x0; local C2 = -(A2 * x0 + B2 * y0)
local tl0 = A0 > 0 or (A0 == 0 and B0 > 0)
local tl1 = A1 > 0 or (A1 == 0 and B1 > 0)
local tl2 = A2 > 0 or (A2 == 0 and B2 > 0)
local inv = 1 / area
local ra, ga, ba, aa = UnpackColor(readu32(vbuf, va + 32))
local rb, gb, bb, ab = UnpackColor(readu32(vbuf, vb + 32))
local rc, gc, bc, ac = UnpackColor(readu32(vbuf, vc + 32))
local ua, vva, ub, vvb, uc, vvc = readf64(vbuf, va + 16), readf64(vbuf, va + 24), readf64(vbuf, vb + 16), readf64(vbuf, vb + 24), readf64(vbuf, vc + 16), readf64(vbuf, vc + 24)
local textured = t and not (ua == ub and ua == uc and vva == vvb and vva == vvc)
if t and not textured then -- constant uv (e.g. the atlas white pixel): fold the texel into the vertex colours
local tr, tg, tb, ta = SampleTexture(t, ua, vva)
ra, ga, ba, aa = ra * tr / 255, ga * tg / 255, ba * tb / 255, aa * ta / 255
rb, gb, bb, ab = rb * tr / 255, gb * tg / 255, bb * tb / 255, ab * ta / 255
rc, gc, bc, ac = rc * tr / 255, gc * tg / 255, bc * tb / 255, ac * ta / 255
end
local flat = not textured and ra == rb and ra == rc and ga == gb and ga == gc and ba == bb and ba == bc and aa == ab and aa == ac
if flat and aa <= 0 then return end
for y = miny, maxy do
local py = y + 0.5
-- Narrow the x range of this row using the edges (expanded by one pixel, exact test below)
local xl, xr = minx, maxx
local e0, e1, e2 = B0 * py + C0, B1 * py + C1, B2 * py + C2
if A0 ~= 0 then local xe = -e0 / A0 - 0.5; if A0 > 0 then xl = max(xl, floor(xe)) else xr = min(xr, ceil(xe)) end end
if A1 ~= 0 then local xe = -e1 / A1 - 0.5; if A1 > 0 then xl = max(xl, floor(xe)) else xr = min(xr, ceil(xe)) end end
if A2 ~= 0 then local xe = -e2 / A2 - 0.5; if A2 > 0 then xl = max(xl, floor(xe)) else xr = min(xr, ceil(xe)) end end
local row = y * buf_w
for x = xl, xr do
local px = x + 0.5
local w0, w1, w2 = A0 * px + e0, A1 * px + e1, A2 * px + e2
if (w0 > 0 or (w0 == 0 and tl0)) and (w1 > 0 or (w1 == 0 and tl1)) and (w2 > 0 or (w2 == 0 and tl2)) then
local o = (row + x) * 4
if flat then
BlendPixel(o, ra, ga, ba, aa)
else
w0, w1, w2 = w0 * inv, w1 * inv, w2 * inv
local r = w0 * ra + w1 * rb + w2 * rc
local g = w0 * ga + w1 * gb + w2 * gc
local b = w0 * ba + w1 * bb + w2 * bc
local a = w0 * aa + w1 * ab + w2 * ac
if textured then
local tr, tg, tb, ta = SampleTexture(t, w0 * ua + w1 * ub + w2 * uc, w0 * vva + w1 * vvb + w2 * vvc)
r, g, b, a = r * tr / 255, g * tg / 255, b * tb / 255, a * ta / 255
end
BlendPixel(o, r, g, b, a)
end
end
end
end
end
-- Layers: every ImDrawList (one per top level window, popup, tooltip, plus the viewport bg/fg lists) gets its own
-- Frame, stacked by draw order. A layer is covered by TILE x TILE EditableImages (one ImageLabel each) placed
-- relative to the layer's origin (top-left of its content). Primitives are hashed into tiles in layer-relative
-- coordinates, so moving a window only moves its Frame: no tile changes, nothing re-rasterized or uploaded.
-- Only tiles whose hash changed are redrawn; the hash covers everything that affects a tile's pixels.
local TILE = 128
TILE_SIZE = Vector2.new(TILE, TILE)
local P1, P2 = 2147483647, 2147483629 -- two independent 31 bit hashes per tile (collision odds ~2^-62)
local KEY_W = 64 -- tile key = ty * KEY_W + tx (layers up to 16384 px wide)
local CLIP_PAD = 2048 -- content up to this far off screen is kept, so dragging a window past the edge doesn't redraw it
local LAYER_KEEP_FRAMES = 120 -- unused layers are destroyed after this many rendered frames
-- Primitive arrays (reused between frames, no per-frame allocation)
local pr_a, pr_b, pr_c, pr_d, pr_t, pr_g = {}, {}, {}, {}, {}, {} -- vertices (pr_d == false -> triangle), texture, gradient kind
local pr_cx0, pr_cy0, pr_cx1, pr_cy1 = {}, {}, {}, {} -- clip (screen pixels)
local pr_bx0, pr_by0, pr_bx1, pr_by1 = {}, {}, {}, {} -- clipped bounds (screen pixels)
local pr_tex = {} -- texture id
local pr_vb = {} -- vertex buffer (draw list VtxBuffer.Buf)
local pr_k = {} -- layer kind (1..3)
local plist1, plist2, plist3 = {}, {}, {} -- primitive indices per layer kind
@native
local function HashVertex(h1, h2, vbuf, v, ox, oy)
local x, y = readf64(vbuf, v) - ox, readf64(vbuf, v + 8) - oy
local uv = readf64(vbuf, v + 16) * 8192 + readf64(vbuf, v + 24)
local c = readu32(vbuf, v + 32)
h1 = (h1 * 48271 + x * 4096 + y) % P1
h1 = (h1 * 48271 + uv * 4096) % P1
h1 = (h1 * 48271 + c) % P1
h2 = (h2 * 16807 + y * 4093 + x) % P2
h2 = (h2 * 16807 + uv * 65521) % P2
h2 = (h2 * 16807 + c) % P2
return h1, h2
end
-- Axis aligned quad with a linear colour gradient and constant uv (ColorPicker hue/SV/alpha bars, AddRectFilledMultiColor).
-- kind 1: colour varies along y (ca top, cb bottom), kind 2: along x (ca left, cb right). Same pixels as the two triangles.
@native
local function DrawRectGradient(x0, y0, x1, y1, ca, cb, kind, t, u, v, cx0, cy0, cx1, cy1)
local px0, py0 = max(ceil(x0 - 0.5), cx0), max(ceil(y0 - 0.5), cy0)
local px1, py1 = min(ceil(x1 - 0.5), cx1), min(ceil(y1 - 0.5), cy1)
if px0 >= px1 or py0 >= py1 then return end
local ra, ga, ba, aa = UnpackColor(ca)
local rb, gb, bb, ab = UnpackColor(cb)
if t then
local tr, tg, tb, ta = SampleTexture(t, u, v)
ra, ga, ba, aa = ra * tr / 255, ga * tg / 255, ba * tb / 255, aa * ta / 255
rb, gb, bb, ab = rb * tr / 255, gb * tg / 255, bb * tb / 255, ab * ta / 255
end
if kind == 1 then
local inv = 1 / (y1 - y0)
for y = py0, py1 - 1 do
local f = (y + 0.5 - y0) * inv
local nf = 1 - f
FillSpan(y, px0, px1, ra * nf + rb * f, ga * nf + gb * f, ba * nf + bb * f, aa * nf + ab * f)
end
else
-- Every row gets the same colours: when a row's destination equals the previous row's, copy its result
local inv = 1 / (x1 - x0)
local len = (px1 - px0) * 4
local opaque = aa >= 255 and ab >= 255
local prev_dst, prev_o = nil, 0
for y = py0, py1 - 1 do
local o = (y * buf_w + px0) * 4
local dst = (not opaque) and readstring(buf, o, len) or true
if prev_dst ~= nil and dst == prev_dst then
buffer.copy(buf, o, buf, prev_o, len)
else
local oo = o
for x = px0, px1 - 1 do
local f = (x + 0.5 - x0) * inv
local nf = 1 - f
BlendPixel(oo, ra * nf + rb * f, ga * nf + gb * f, ba * nf + bb * f, aa * nf + ab * f)
oo = oo + 4
end
prev_dst = dst
end
prev_o = o
end
end
end
-- Layer kinds per draw list: 1 = drawn before the window content (background, title bar, borders, scrollbar),
-- 2 = window content (positioned at the scroll origin inside a ClipsDescendants frame, so scrolling just moves it),
-- 3 = anything not clipped to the content drawn after content started (menu bar, overlays). Stacked 1 < 2 < 3.
local function NewFrame(parent, clips)
local frame = Instance.new("Frame")
frame.Name = "Layer"
frame.BackgroundTransparency = 1
frame.BorderSizePixel = 0
frame.Size = UDim2.fromOffset(0, 0)
frame.ClipsDescendants = clips
frame.Visible = false
frame.Parent = parent
return frame
end
local function GetLayer(bd, draw_list, kind)
local set = bd.Layers[draw_list]
if not set then set = { LastUsed = 0 }; bd.Layers[draw_list] = set end
local layer = set[kind]
if layer then return layer end
local root, frame
if kind == 2 then
root = NewFrame(bd.Gui, true)
frame = NewFrame(root, false); frame.Visible = true
else
frame = NewFrame(bd.Gui, false); root = frame
end
layer = { Root = root, Frame = frame, Tiles = {}, TH1 = {}, TH2 = {}, TN = {}, TL = {}, TX = {}, TY = {}, Touched = {}, NTouched = 0,
Visible = false, X = false, Y = false, Z = -1, CX0 = false, CY0 = false, CX1 = false, CY1 = false }
set[kind] = layer
return layer
end
local function HideLayer(layer)
if layer.Visible then layer.Visible = false; layer.Root.Visible = false end
end
local function GetTile(bd, layer, key, tx, ty)
local tile = layer.Tiles[key]
if tile then return tile end
local img = AssetService:CreateEditableImage({ Size = Vector2.new(TILE, TILE) })
assert(img, "imgui_impl_roblox: EditableImage memory budget exceeded")
local label = Instance.new("ImageLabel")
label.Name = "Tile" .. key
label.BackgroundTransparency = 1
label.BorderSizePixel = 0
local scale = bd.Scale
label.Size = UDim2.fromOffset(TILE / scale, TILE / scale)
label.Position = UDim2.fromOffset(tx * TILE / scale, ty * TILE / scale)
label.ResampleMode = Enum.ResamplerMode.Pixelated
label.ImageContent = Content.fromObject(img)
label.Visible = false
label.Active = bd.TilesActive
label.Parent = layer.Frame
tile = { Image = img, Label = label, Buffer = buffer.create(TILE * TILE * 4), H1 = -1, H2 = -1, Visible = false, BX0 = TILE, BY0 = TILE, BX1 = 0, BY1 = 0 }
layer.Tiles[key] = tile
return tile
end
local function DestroyLayerSet(set)
for kind = 1, 3 do
local layer = set[kind]
if layer then
for _, tile in pairs(layer.Tiles) do tile.Image:Destroy() end
layer.Root:Destroy()
end
end
end
local function DestroyTiles(bd)
for _, set in pairs(bd.Layers) do DestroyLayerSet(set) end
bd.Layers = {}
end
-- Exact signature of everything in a draw list that affects its layers (nil = can't skip: user callbacks)
local sig_buf = buffer.create(4096)
@native
local function DrawListSignature(draw_list, ox, oy)
local idx, ni = draw_list.IdxBuffer.Data, draw_list.IdxBuffer.Size
local ncmd = draw_list.CmdBuffer.Size
local need = ni * 4 + ncmd * 64 + 64
if buffer.len(sig_buf) < need then sig_buf = buffer.create(need * 2) end
local b, o = sig_buf, 0
for i = 1, ni do writeu32(b, o, idx[i]); o += 4 end
for _, pcmd in draw_list.CmdBuffer:iter() do
if pcmd.UserCallback ~= nil then return nil end
local c = pcmd.ClipRect
buffer.writef64(b, o, c.x); buffer.writef64(b, o + 8, c.y); buffer.writef64(b, o + 16, c.z); buffer.writef64(b, o + 24, c.w)
writeu32(b, o + 32, pcmd.ElemCount); writeu32(b, o + 36, pcmd.IdxOffset); writeu32(b, o + 40, pcmd.VtxOffset)
buffer.writef64(b, o + 44, pcmd:GetTexID())
o += 52
end
buffer.writef64(b, o, ox); buffer.writef64(b, o + 8, oy)
buffer.writef64(b, o + 16, draw_list._ContentClipX0 or -1); buffer.writef64(b, o + 24, draw_list._ContentClipY0 or -1)
buffer.writef64(b, o + 32, draw_list._ContentClipX1 or -1); buffer.writef64(b, o + 40, draw_list._ContentClipY1 or -1)
buffer.writef64(b, o + 48, draw_list._ContentClipX0 and draw_list._ScrollOriginX or -1)
buffer.writef64(b, o + 56, draw_list._ContentClipX0 and draw_list._ScrollOriginY or -1)
o += 64
return readstring(draw_list.VtxBuffer.Buf, 0, draw_list.VtxBuffer.Size * VTX_STRIDE) .. readstring(b, 0, o)
end
-- Overlays: user Instances (e.g. a Frame holding a ViewportFrame) placed inside a window, registered every frame with
-- ImGui_ImplRoblox.SetOverlay() while that window is current. They stack right above the window's layers, move with
-- it, and (clip = true) are clipped to the window's content area like its widgets.
local function OverlayHolder(bd, draw_list, clip)
local hs = bd.OverlayHolders[draw_list]
if not hs then hs = {}; bd.OverlayHolders[draw_list] = hs end
local h = hs[clip]
if not h then
h = Instance.new("Frame")
h.Name = clip and "OverlayClip" or "Overlay"
h.BackgroundTransparency = 1
h.BorderSizePixel = 0
h.ClipsDescendants = clip
h.Size = UDim2.fromOffset(0, 0)
h.Parent = bd.Gui
hs[clip] = h
end
return h
end
local function PlaceOverlays(bd, draw_list, z, ox, oy)
local list = bd.Overlays[draw_list]
local hs = bd.OverlayHolders[draw_list]
if not list then
if hs then for _, h in pairs(hs) do h.Visible = false end end
return z
end
local scale, frame_no = bd.Scale, bd.FrameNo
z += 1
local used = {}
for _, o in ipairs(list) do
local clip = o.Clip and draw_list._ContentClipX0 ~= nil
local h = OverlayHolder(bd, draw_list, clip)
local hx, hy = 0, 0
if clip then
hx, hy = draw_list._ContentClipX0 - ox, draw_list._ContentClipY0 - oy
if not used[h] then
h.Position = UDim2.fromOffset(hx / scale, hy / scale)
h.Size = UDim2.fromOffset((draw_list._ContentClipX1 - draw_list._ContentClipX0) / scale, (draw_list._ContentClipY1 - draw_list._ContentClipY0) / scale)
end
elseif not used[h] then
h.Position = UDim2.fromOffset(0, 0)
end
used[h] = true
h.ZIndex = z
h.Visible = true
local f = o.Frame
if f.Parent ~= h then f.Parent = h end
f.Position = UDim2.fromOffset((o.X - ox - hx) / scale, (o.Y - oy - hy) / scale)
f.Size = UDim2.fromOffset(o.W / scale, o.H / scale)
f.Visible = true
bd.OverlayShown[f] = frame_no
end
if hs then for _, h in pairs(hs) do if not used[h] then h.Visible = false end end end
return z
end
--- Show `frame` this frame at (x, y, w, h) (imgui coordinates) inside the current window. Call every frame it should
--- be visible; frames not submitted are hidden. clip: clip to the window's content area (scrolls with it).
function ImGui_ImplRoblox_SetOverlay(frame, x, y, w, h, clip)
local bd = ImGui_ImplRoblox_GetBackendData()
local dl = ImGui.GetWindowDrawList()
local list = bd.Overlays[dl]
if not list then list = {}; bd.Overlays[dl] = list end
list[#list + 1] = { Frame = frame, X = x, Y = y, W = w, H = h, Clip = clip ~= false }
end
-- MicroProfiler labels, enabled with ImGui_ImplRoblox.SetProfiling(true)
local profilebegin, profileend = debug.profilebegin, debug.profileend
local profiling = false
local function PB(name) if profiling then profilebegin(name) end end
local function PE() if profiling then profileend() end end
@native
local function DrawLayer(bd, layer, plist, np, lx0, ly0, ox, oy, force, z, clip_x0, clip_y0, clip_x1, clip_y1)
local scale = bd.Scale
-- Pass 2: hash primitives into layer-relative tiles
PB("ImGui tile hash")
local th1, th2, tn, tl, touched = layer.TH1, layer.TH2, layer.TN, layer.TL, layer.Touched
for k = 1, layer.NTouched do tn[touched[k]] = 0 end
local nt = 0
for pi = 1, np do
local p = plist[pi]
local tex_id = pr_tex[p]
-- The clip rect only affects pixels inside the primitive's bounds, so hash the clipped bounds (relative)
-- instead of the clip itself: a window clipped by the (fixed) viewport rect stays hash-stable when moved.
local cx0, cy0, cx1, cy1 = pr_bx0[p] - lx0, pr_by0[p] - ly0, pr_bx1[p] - lx0, pr_by1[p] - ly0
local h1 = ((cx0 * 8191 + cy0) * 8191 + cx1) % P1
local h2 = ((cy1 * 8191 + cx1) * 8191 + cy0 + tex_id) % P2
local vax, vay = lx0 + ox, ly0 + oy
local vbuf = pr_vb[p]
h1, h2 = HashVertex(h1, h2, vbuf, pr_a[p], vax, vay)
h1, h2 = HashVertex(h1, h2, vbuf, pr_b[p], vax, vay)
h1, h2 = HashVertex(h1, h2, vbuf, pr_c[p], vax, vay)
local vd = pr_d[p]
if vd then h1, h2 = HashVertex(h1, h2, vbuf, vd, vax, vay) end
for ty = floor((pr_by0[p] - ly0) / TILE), floor((pr_by1[p] - 1 - ly0) / TILE) do
for tx = floor((pr_bx0[p] - lx0) / TILE), floor((pr_bx1[p] - 1 - lx0) / TILE) do
local key = ty * KEY_W + tx
local k = tn[key]
if not k or k == 0 then
k = 0
th1[key], th2[key] = 0, 0
if not tl[key] then tl[key] = {} end
nt = nt + 1
touched[nt] = key
layer.TX[key], layer.TY[key] = tx, ty
end
k = k + 1
tn[key] = k
tl[key][k] = p
th1[key] = (th1[key] * 48271 + h1) % P1
th2[key] = (th2[key] * 16807 + h2 + k) % P2
end
end
end
layer.NTouched = nt
PE()
-- Place the layer (this is all a window move costs)
local root = layer.Root
if root ~= layer.Frame then
-- content: clip frame at the content clip rect, tiles frame at the scroll origin relative to it
if layer.CX0 ~= clip_x0 or layer.CY0 ~= clip_y0 or layer.CX1 ~= clip_x1 or layer.CY1 ~= clip_y1 then
layer.CX0, layer.CY0, layer.CX1, layer.CY1 = clip_x0, clip_y0, clip_x1, clip_y1
root.Position = UDim2.fromOffset(clip_x0 / scale, clip_y0 / scale)
root.Size = UDim2.fromOffset((clip_x1 - clip_x0) / scale, (clip_y1 - clip_y0) / scale)
layer.X = false
end
if layer.X ~= lx0 or layer.Y ~= ly0 then
layer.X, layer.Y = lx0, ly0
layer.Frame.Position = UDim2.fromOffset((lx0 - clip_x0) / scale, (ly0 - clip_y0) / scale)
end
elseif layer.X ~= lx0 or layer.Y ~= ly0 then
layer.X, layer.Y = lx0, ly0
root.Position = UDim2.fromOffset(lx0 / scale, ly0 / scale)
end
if layer.Z ~= z then layer.Z = z; root.ZIndex = z end
if not layer.Visible then layer.Visible = true; root.Visible = true end
-- Pass 3: redraw + upload changed tiles, hide unused ones
PB("ImGui raster+upload")
for key, tile in pairs(layer.Tiles) do
if not tn[key] or tn[key] == 0 then
if tile.Visible then tile.Visible = false; tile.Label.Visible = false; tile.H1 = -1 end
end
end
for kk = 1, nt do
local key = touched[kk]
local count = tn[key]
local tx, ty = layer.TX[key], layer.TY[key]
local tile = GetTile(bd, layer, key, tx, ty)
if force or tile.H1 ~= th1[key] or tile.H2 ~= th2[key] then
tile.H1, tile.H2 = th1[key], th2[key]
local x0, y0 = lx0 + tx * TILE, ly0 + ty * TILE
local x1, y1 = x0 + TILE, y0 + TILE
buf, buf_w = tile.Buffer, TILE
local list = tl[key]
-- Dirty region = old content bounds + new content bounds. Outside it the tile is already
-- transparent, so only this region is cleared and uploaded (edge tiles are often mostly empty).
local nx0, ny0, nx1, ny1 = TILE, TILE, 0, 0
for k = 1, count do
local p = list[k]
local a, b = pr_bx0[p] - x0, pr_by0[p] - y0
local c, d = pr_bx1[p] - x0, pr_by1[p] - y0
if a < nx0 then nx0 = a end
if b < ny0 then ny0 = b end
if c > nx1 then nx1 = c end
if d > ny1 then ny1 = d end
end
nx0, ny0, nx1, ny1 = max(nx0, 0), max(ny0, 0), min(nx1, TILE), min(ny1, TILE)
local rx0, ry0, rx1, ry1 = min(nx0, tile.BX0), min(ny0, tile.BY0), max(nx1, tile.BX1), max(ny1, tile.BY1)
tile.BX0, tile.BY0, tile.BX1, tile.BY1 = nx0, ny0, nx1, ny1
local rw = rx1 - rx0
if rw == TILE then
buffer.fill(buf, ry0 * TILE * 4, 0, (ry1 - ry0) * TILE * 4)
else
for y = ry0, ry1 - 1 do buffer.fill(buf, (y * TILE + rx0) * 4, 0, rw * 4) end
end
local tox, toy = ox + x0, oy + y0
for k = 1, count do
local p = list[k]
local cx0, cy0 = max(pr_cx0[p], x0) - x0, max(pr_cy0[p], y0) - y0
local cx1, cy1 = min(pr_cx1[p], x1) - x0, min(pr_cy1[p], y1) - y0
local va, vc, vd, vbuf = pr_a[p], pr_c[p], pr_d[p], pr_vb[p]
if vd then
local ax, ay, cx, cy = readf64(vbuf, va) - tox, readf64(vbuf, va + 8) - toy, readf64(vbuf, vc) - tox, readf64(vbuf, vc + 8) - toy
local gk = pr_g[p]
if gk then
DrawRectGradient(ax, ay, cx, cy, readu32(vbuf, va + 32), readu32(vbuf, vc + 32), gk, pr_t[p], readf64(vbuf, va + 16), readf64(vbuf, va + 24), cx0, cy0, cx1, cy1)
else
DrawRect(ax, ay, cx, cy, readf64(vbuf, va + 16), readf64(vbuf, va + 24), readf64(vbuf, vc + 16), readf64(vbuf, vc + 24), readu32(vbuf, va + 32), pr_t[p], cx0, cy0, cx1, cy1)
end
else
DrawTriangle(vbuf, va, pr_b[p], vc, pr_t[p], cx0, cy0, cx1, cy1, tox, toy)
end
end
PB("ImGui upload")
if rw == TILE and ry0 == 0 and ry1 == TILE then
tile.Image:WritePixelsBuffer(Vector2.zero, TILE_SIZE, buf)
elseif rw > 0 and ry1 > ry0 then
local rh = ry1 - ry0
local sub = buffer.create(rw * rh * 4)
for y = 0, rh - 1 do buffer.copy(sub, y * rw * 4, buf, ((ry0 + y) * TILE + rx0) * 4, rw * 4) end
tile.Image:WritePixelsBuffer(Vector2.new(rx0, ry0), Vector2.new(rw, rh), sub)
end
PE()
end
if not tile.Visible then
tile.Visible = true
tile.Label.Visible = true
end
end
PE()
end
@native
function ImGui_ImplRoblox_RenderDrawData(draw_data)
local bd = ImGui_ImplRoblox_GetBackendData()
PB("ImGui RenderDrawData")
PB("ImGui textures")
if draw_data.Textures ~= nil then
for _, tex in draw_data.Textures:iter() do
if tex.Status ~= ImTextureStatus.OK then
ImGui_ImplRoblox_UpdateTexture(tex)
bd.ForceRedraw = true -- texture contents changed: tiles sampling it must be redrawn
end
end
end
PE()
-- Render rate cap: textures are always updated (imgui expects it), tiles only at bd.RenderRate Hz
-- Optional lower cap while scrolling / resizing / moving a window (SetBusyRenderRate, off by default)
local rate = bd.RenderRate
if bd.BusyRenderRate > 0 then
local g = ImGui.GetCurrentContext()
local busy = g.WheelingWindow ~= nil or g.MovingWindow ~= nil -- (io.MouseWheel is already cleared by EndFrame)
if not busy and g.ActiveId ~= 0 then
local w = g.ActiveIdWindow
local cur = g.MouseCursor -- ResizeAll..ResizeNWSE while a resize grip/border is held
busy = (cur >= ImGuiMouseCursor.ResizeAll and cur <= ImGuiMouseCursor.ResizeNWSE)
or (w ~= nil and (g.ActiveId == ImGui.GetWindowScrollbarID(w, ImGuiAxis.X) or g.ActiveId == ImGui.GetWindowScrollbarID(w, ImGuiAxis.Y)))
end
if busy and (rate <= 0 or bd.BusyRenderRate < rate) then rate = bd.BusyRenderRate end
end
if rate > 0 then
local now = os.clock()
if now + 0.002 < bd.NextRender then table.clear(bd.Overlays); PE(); return end
bd.NextRender = math.max(bd.NextRender + 1 / rate, now)
end
local sw, sh = floor(draw_data.DisplaySize.x), floor(draw_data.DisplaySize.y)
if sw <= 0 or sh <= 0 then PE(); return end
local ox, oy = draw_data.DisplayPos.x, draw_data.DisplayPos.y
local lim_x0, lim_y0, lim_x1, lim_y1 = -CLIP_PAD, -CLIP_PAD, sw + CLIP_PAD, sh + CLIP_PAD
bd.FrameNo += 1
local frame_no = bd.FrameNo
local force = bd.ForceRedraw
bd.ForceRedraw = false
local n = 0
local z = 0
for _, draw_list in draw_data.CmdLists:iter() do
-- Unchanged draw list (same vertex bytes, indices, commands, origin and scroll): its layers are already
-- correct, only restack them. Static windows then cost one byte compare instead of collect + hash.
PB("ImGui unchanged check")
local sig = DrawListSignature(draw_list, ox, oy)
local set = bd.Layers[draw_list]
if sig and set and not force and set.Sig == sig then
for kind = 1, 3 do
local layer = set[kind]
if layer and layer.Visible then
z += 1
if layer.Z ~= z then layer.Z = z; layer.Root.ZIndex = z end
end
end
set.LastUsed = frame_no
z = PlaceOverlays(bd, draw_list, z, ox, oy)
PE()
continue
end
PE()
-- Pass 1: collect this list's primitives and their bounds
PB("ImGui collect")
local first = n + 1
local vbuf, idx = draw_list.VtxBuffer.Buf, draw_list.IdxBuffer.Data
local ccx0, ccy0, ccx1, ccy1 = draw_list._ContentClipX0, draw_list._ContentClipY0, draw_list._ContentClipX1, draw_list._ContentClipY1
local content_x0, content_y0, content_x1, content_y1
if ccx0 then
content_x0, content_y0 = max(floor(ccx0 - ox), lim_x0), max(floor(ccy0 - oy), lim_y0)
content_x1, content_y1 = min(floor(ccx1 - ox), lim_x1), min(floor(ccy1 - oy), lim_y1)
end
local seen_content = false
for _, pcmd in draw_list.CmdBuffer:iter() do
if pcmd.UserCallback ~= nil then
pcmd.UserCallback(draw_list, pcmd)
elseif pcmd.ElemCount > 0 then
local clip = pcmd.ClipRect
local cx0, cy0 = max(floor(clip.x - ox), lim_x0), max(floor(clip.y - oy), lim_y0)
local cx1, cy1 = min(floor(clip.z - ox), lim_x1), min(floor(clip.w - oy), lim_y1)
local kind = 1
if ccx0 and clip.x >= ccx0 and clip.y >= ccy0 and clip.z <= ccx1 and clip.w <= ccy1 then
kind = 2; seen_content = true
if clip.x == ccx0 and clip.y == ccy0 and clip.z == ccx1 and clip.w == ccy1 then
-- clipped by the layer's clip frame instead: partly visible rows stay hash-stable while scrolling
cx0, cy0, cx1, cy1 = lim_x0, lim_y0, lim_x1, lim_y1
end
elseif seen_content then
kind = 3
end
if cx1 > cx0 and cy1 > cy0 then
local tex_id = pcmd:GetTexID()
local t = bd.Textures[tex_id]
local vo = pcmd.VtxOffset
local i, last = pcmd.IdxOffset + 1, pcmd.IdxOffset + pcmd.ElemCount
while i <= last do
local ia, ic = idx[i], idx[i + 2]
-- byte offsets of the vertices (index is 1-based)
local va, vb, vc = (vo + ia - 1) * VTX_STRIDE, (vo + idx[i + 1] - 1) * VTX_STRIDE, (vo + ic - 1) * VTX_STRIDE
local vd = false
local gk = false
local pax, pay = readf64(vbuf, va), readf64(vbuf, va + 8)
local pbx, pby = readf64(vbuf, vb), readf64(vbuf, vb + 8)
local pcx, pcy = readf64(vbuf, vc), readf64(vbuf, vc + 8)
local bx0, by0, bx1, by1
if i + 5 <= last and idx[i + 3] == ia and idx[i + 4] == ic then
local d = (vo + idx[i + 5] - 1) * VTX_STRIDE
local pdx, pdy = readf64(vbuf, d), readf64(vbuf, d + 8)
-- axis aligned quad (TL, TR, BR, BL)
if pay == pby and pbx == pcx and pcy == pdy and pdx == pax and pax < pbx and pay < pdy then
local col, colb, colc, cold = readu32(vbuf, va + 32), readu32(vbuf, vb + 32), readu32(vbuf, vc + 32), readu32(vbuf, d + 32)
local tax, tay = readf64(vbuf, va + 16), readf64(vbuf, va + 24)
local tbx, tby = readf64(vbuf, vb + 16), readf64(vbuf, vb + 24)
local tcx, tcy = readf64(vbuf, vc + 16), readf64(vbuf, vc + 24)
local tdx, tdy = readf64(vbuf, d + 16), readf64(vbuf, d + 24)
if colb == col and colc == col and cold == col then
if tbx == tcx and tby == tay and tdx == tax and tdy == tcy then vd = d end
elseif tax == tbx and tax == tcx and tax == tdx and tay == tby and tay == tcy and tay == tdy then
-- constant uv, linear gradient: vertical (top/bottom pairs equal) or horizontal (left/right pairs equal)
if colb == col and cold == colc then vd = d; gk = 1
elseif cold == col and colb == colc then vd = d; gk = 2 end
end
if vd then
bx0, by0 = ceil(pax - ox - 0.5), ceil(pay - oy - 0.5)
bx1, by1 = ceil(pcx - ox - 0.5), ceil(pcy - oy - 0.5)
end
end
end
if vd then
i = i + 6
else
bx0, by0 = floor(min(pax, pbx, pcx) - ox), floor(min(pay, pby, pcy) - oy)
bx1, by1 = ceil(max(pax, pbx, pcx) - ox) + 1, ceil(max(pay, pby, pcy) - oy) + 1
i = i + 3
end
if bx0 < cx0 then bx0 = cx0 end
if by0 < cy0 then by0 = cy0 end
if bx1 > cx1 then bx1 = cx1 end
if by1 > cy1 then by1 = cy1 end
if bx0 < bx1 and by0 < by1 then
n = n + 1
pr_a[n], pr_b[n], pr_c[n], pr_d[n], pr_t[n], pr_g[n], pr_tex[n], pr_vb[n] = va, vb, vc, vd, t, gk, tex_id, vbuf
pr_cx0[n], pr_cy0[n], pr_cx1[n], pr_cy1[n] = cx0, cy0, cx1, cy1
pr_bx0[n], pr_by0[n], pr_bx1[n], pr_by1[n] = bx0, by0, bx1, by1
pr_k[n] = kind
end
end
end
end
end
PE()
-- Split into layer kinds and place each one
set = bd.Layers[draw_list]
local nk1, nk2, nk3 = 0, 0, 0
local o1x, o1y, o3x, o3y = math.huge, math.huge, math.huge, math.huge
for p = first, n do
local k = pr_k[p]
if k == 1 then
nk1 += 1; plist1[nk1] = p
if pr_bx0[p] < o1x then o1x = pr_bx0[p] end
if pr_by0[p] < o1y then o1y = pr_by0[p] end
elseif k == 2 then
nk2 += 1; plist2[nk2] = p
else
nk3 += 1; plist3[nk3] = p
if pr_bx0[p] < o3x then o3x = pr_bx0[p] end
if pr_by0[p] < o3y then o3y = pr_by0[p] end
end
end
if nk1 > 0 then
z += 1
DrawLayer(bd, GetLayer(bd, draw_list, 1), plist1, nk1, o1x, o1y, ox, oy, force, z)
elseif set and set[1] then HideLayer(set[1]) end
if nk2 > 0 then
z += 1
DrawLayer(bd, GetLayer(bd, draw_list, 2), plist2, nk2, floor(draw_list._ScrollOriginX - ox), floor(draw_list._ScrollOriginY - oy), ox, oy, force, z,
content_x0, content_y0, content_x1, content_y1)
elseif set and set[2] then HideLayer(set[2]) end
if nk3 > 0 then
z += 1
DrawLayer(bd, GetLayer(bd, draw_list, 3), plist3, nk3, o3x, o3y, ox, oy, force, z)
elseif set and set[3] then HideLayer(set[3]) end
set = bd.Layers[draw_list]
if set then set.LastUsed = frame_no; set.Sig = sig end
z = PlaceOverlays(bd, draw_list, z, ox, oy)
end
-- Overlay frames not submitted this frame are hidden (never destroyed: the user owns them)
for frame, shown in pairs(bd.OverlayShown) do
if shown ~= frame_no then frame.Visible = false; bd.OverlayShown[frame] = nil end
end
table.clear(bd.Overlays)
-- Hide layers not drawn this frame; free long unused ones (closed windows, old tooltips)
for draw_list, set in pairs(bd.Layers) do
if set.LastUsed ~= frame_no then
set.Sig = nil -- hidden now: must go through the full path when shown again
for kind = 1, 3 do if set[kind] then HideLayer(set[kind]) end end
if frame_no - set.LastUsed > LAYER_KEEP_FRAMES then
DestroyLayerSet(set)
bd.Layers[draw_list] = nil
end
end
end
-- drop references so old vertex tables can be collected
for k = n + 1, bd.LastPrimCount do pr_t[k], pr_vb[k] = nil, nil end
bd.LastPrimCount = n
PE()
end
---------------------------------------------------------
-- CORE LIFECYCLE
---------------------------------------------------------
--- @param parent Instance? # where the ScreenGui goes, defaults to the local player's PlayerGui
--- @param render_scale number? # imgui pixels per Roblox UI point (defaults to 1). Roblox UI points are scaled by the
--- # OS display scale, so on a 150% display pass 1.5 to render at physical resolution
--- # (imgui then looks the same size as a desktop imgui app). Change later with SetRenderScale().
function ImGui_ImplRoblox_Init(parent, render_scale)
local io = ImGui.GetIO()
local gui = Instance.new("ScreenGui")
gui.Name = "ImGui"
gui.IgnoreGuiInset = true -- so GetMouseLocation() and the tiles share the same origin
gui.ResetOnSpawn = false
gui.DisplayOrder = 1000
gui.ZIndexBehavior = Enum.ZIndexBehavior.Sibling -- layers (one Frame per draw list) stack by ZIndex
gui.Parent = parent or Players.LocalPlayer:WaitForChild("PlayerGui")
local bd = {
Time = os.clock(), Gui = gui, Connections = {},
Textures = {}, TextureCount = 0, MouseX = -1, MouseY = -1,
Layers = {}, Overlays = {}, OverlayHolders = {}, OverlayShown = {}, FrameNo = 0, Scale = render_scale or 1, TilesActive = false, RenderRate = 60, BusyRenderRate = 0, NextRender = 0, LastPrimCount = 0, ForceRedraw = true,
}
io.BackendPlatformUserData = bd
io.BackendFlags = bit32.bor(io.BackendFlags, ImGuiBackendFlags.RendererHasTextures, ImGuiBackendFlags.RendererHasVtxOffset)
local platform_io = ImGui.GetPlatformIO()
platform_io.Platform_SetClipboardTextFn = ImGui_ImplRoblox_PlatformSetClipboardText
platform_io.Platform_GetClipboardTextFn = ImGui_ImplRoblox_PlatformGetClipboardText
local screen = gui.AbsoluteSize
ImGui_ImplRoblox_UpdateMonitors(screen.X, screen.Y)
local function connect(signal, fn) table.insert(bd.Connections, signal:Connect(fn)) end
connect(UserInputService.InputBegan, function(input, game_processed)
local io = ImGui.GetIO()
local button = MOUSE_BUTTONS[input.UserInputType]
if button then
io:AddMouseSourceEvent(ImGuiMouseSource.Mouse)
io:AddMouseButtonEvent(button, true)
elseif input.UserInputType == Enum.UserInputType.Keyboard and (not game_processed or proxy_focused) then
local ctrl, shift, alt = ImGui_ImplRoblox_UpdateKeyModifiers()
local key = KEY_MAP[input.KeyCode]
if key then io:AddKeyEvent(key, true) end
if proxy_focused and (key == ImGuiKey.Backspace or key == ImGuiKey.Delete) then ImGui_ImplRoblox_GetBackendData().DeleteKeySeen = true end
-- Text: printable ASCII keys, skipped while Ctrl/Alt are held (shortcuts)
local v = input.KeyCode.Value
if v >= 32 and v < 127 and not (ctrl or alt) then
local c = string.char(v)
if shift then c = SHIFTED[c] or c:upper() end
-- While the proxy may own text input, hold the char: NewFrame uses the proxy's text if it changed
-- (correct layout/unicode), otherwise these. So typing works even if the proxy silently lost focus.
if proxy_focused then table.insert(ImGui_ImplRoblox_GetBackendData().PendingChars, string.byte(c))
else io:AddInputCharacter(string.byte(c)) end
end
end
end)
connect(UserInputService.InputEnded, function(input, game_processed)
local io = ImGui.GetIO()
local button = MOUSE_BUTTONS[input.UserInputType]
if button then
io:AddMouseButtonEvent(button, false)
elseif input.UserInputType == Enum.UserInputType.Keyboard then
ImGui_ImplRoblox_UpdateKeyModifiers()
local key = KEY_MAP[input.KeyCode]
if key then io:AddKeyEvent(key, false) end
end
end)
connect(UserInputService.InputChanged, function(input, game_processed)
if input.UserInputType == Enum.UserInputType.MouseWheel then
ImGui.GetIO():AddMouseWheelEvent(0, input.Position.Z)
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).
local proxy = Instance.new("TextBox")
proxy.Name = "TextProxy"
proxy.BackgroundTransparency = 1
proxy.TextTransparency = 0 -- kept opaque but parked off screen: a transparent TextBox may not get native paste
proxy.BorderSizePixel = 0
proxy.Size = UDim2.fromOffset(200, 20)
proxy.Position = UDim2.fromOffset(-10000, -10000)
proxy.MultiLine = true
proxy.ClearTextOnFocus = false
proxy.TextEditable = true
proxy.Text = ""
proxy.Parent = gui
bd.Proxy, bd.ProxyText, bd.PendingChars = 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
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.
if ImGui.GetIO().WantCaptureMouse then bd.ProxyLostId = nil; return end
bd.ProxyLostId = bd.ProxyActiveId -- don't recapture for the same field
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()
local io = ImGui.GetIO()
local bd = ImGui_ImplRoblox_GetBackendData()
for _, c in ipairs(bd.Connections) do c:Disconnect() end
DestroyTiles(bd)
bd.Gui:Destroy()
io.BackendPlatformUserData = nil
io.BackendFlags = bit32.band(io.BackendFlags, bit32.bnot(bit32.bor(
ImGuiBackendFlags.RendererHasTextures,
ImGuiBackendFlags.RendererHasVtxOffset
)))
end
function ImGui_ImplRoblox_NewFrame()
PB("ImGui NewFrame (backend)")
local io = ImGui.GetIO()
local bd = ImGui_ImplRoblox_GetBackendData()
local screen = bd.Gui.AbsoluteSize
local w, h = floor(screen.X * bd.Scale), floor(screen.Y * bd.Scale)
if w ~= bd.ScreenW or h ~= bd.ScreenH then
bd.ScreenW, bd.ScreenH = w, h
ImGui_ImplRoblox_UpdateMonitors(w, h)
end
ImVec2_CopyV(io.DisplaySize, w, h)
local current_time = os.clock()
io.DeltaTime = (current_time > bd.Time) and (current_time - bd.Time) or (1.0 / 60.0)
bd.Time = current_time
local m = UserInputService:GetMouseLocation()
if m.X ~= bd.MouseX or m.Y ~= bd.MouseY then
bd.MouseX, bd.MouseY = m.X, m.Y
io:AddMouseSourceEvent(ImGuiMouseSource.Mouse)
io:AddMousePosEvent(m.X * bd.Scale, m.Y * bd.Scale)
end
-- Text proxy: focused while an imgui text field is active. proxy_focused only when Roblox really gave it focus,
-- 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
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
proxy:ReleaseFocus()
bd.ProxyReleasing = false
focused_box = nil
end
local was_focused = proxy_focused
proxy_focused = 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
-- Ctrl still down, so release Ctrl around the characters in the event queue.
local ctrl = io.KeyCtrl or UserInputService:IsKeyDown(Enum.KeyCode.LeftControl) or UserInputService:IsKeyDown(Enum.KeyCode.RightControl)
if ctrl then io:AddKeyEvent(ImGuiMod_Ctrl, false) end
local prev = bd.ProxyText or ""
if #text < #prev and prev:sub(1, #text) == text and text:sub(-1) ~= "\n" then
-- The TextBox deleted from its own text (Backspace/Delete; Roblox can't hold a real selection in it, so it
-- may remove just 1 char). Apply the deletion with imgui's own selection instead: one Backspace deletes
-- the whole imgui selection, or one char if none. Skipped if imgui already got the key event.
if not bd.DeleteKeySeen then io:AddKeyEvent(ImGuiKey.Backspace, true); io:AddKeyEvent(ImGuiKey.Backspace, false) end
elseif text ~= "\n" and text ~= "\r" and text ~= "\t" then -- Enter/Tab arrive as key events
local prev = bd.ProxyText or ""
if #text > 0 and (prev == "" or text:sub(1, #prev) ~= prev or #text <= #prev) then
for _, cp in utf8.codes(text) do io:AddInputCharacter(cp) end
elseif #text > #prev then
for _, cp in utf8.codes(text:sub(#prev + 1)) do io:AddInputCharacter(cp) end
end
end
if ctrl then io:AddKeyEvent(ImGuiMod_Ctrl, true) end
used_proxy_text = true
bd.ProxyText = nil
end
-- 2) mirror imgui's selection, fully selected, so the native Ctrl+C / Ctrl+X copy exactly that
local st = g.InputTextState
local sel = ""
if st and st.ID ~= 0 and st.ID == g.ActiveId and st.Stb and st:HasSelection() then
local a, b = math.min(st.Stb.select_start, st.Stb.select_end), math.max(st.Stb.select_start, st.Stb.select_end)
sel = ImGui._ByteArrayToString(st.TextA.Data, a, b) -- stb positions are 1-based in this port
end
if sel ~= bd.ProxyText then
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
if proxy.SelectionStart ~= want_sel then proxy.SelectionStart = want_sel end
if proxy.CursorPosition ~= want_cur then proxy.CursorPosition = want_cur end
end
bd.DeleteKeySeen = false
-- Held KeyCode chars: dropped if the proxy delivered the text, otherwise typed (proxy didn't really get the keys)
local pending = bd.PendingChars
if #pending > 0 then
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
if want ~= bd.TilesActive then
bd.TilesActive = want
for _, set in pairs(bd.Layers) do for kind = 1, 3 do local layer = set[kind]; if layer then for _, tile in pairs(layer.Tiles) do tile.Label.Active = want end end end end
end
PE()
end
--- Max tile redraws per second (default 60); 0 = every frame. imgui logic still runs every frame.
function ImGui_ImplRoblox_SetRenderRate(hz)
ImGui_ImplRoblox_GetBackendData().RenderRate = hz or 0
end
--- Optional: max tile redraws per second while scrolling, resizing or moving a window (0 = off, the default)
function ImGui_ImplRoblox_SetBusyRenderRate(hz)
ImGui_ImplRoblox_GetBackendData().BusyRenderRate = hz or 0
end
--- Toggle MicroProfiler labels (debug.profilebegin) for the backend
function ImGui_ImplRoblox_SetProfiling(enabled) profiling = enabled and true or false end
local function ImGui_ImplRoblox_IsProfiling() return profiling end
function ImGui_ImplRoblox_SetRenderScale(scale)
local bd = ImGui_ImplRoblox_GetBackendData()
if scale == bd.Scale then return end
bd.Scale = scale
DestroyTiles(bd)
bd.ForceRedraw = true
end
ImGui_ImplRoblox = {
Init = ImGui_ImplRoblox_Init,
Shutdown = ImGui_ImplRoblox_Shutdown,
NewFrame = ImGui_ImplRoblox_NewFrame,
RenderDrawData = ImGui_ImplRoblox_RenderDrawData,
AddFile = ImGui_ImplRoblox_AddFile,
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
CreateTexture = ImGui_ImplRoblox_CreateTexture,
DestroyTexture = ImGui_ImplRoblox_DestroyTexture,
GetRenderScale = function() return ImGui_ImplRoblox_GetBackendData().Scale end,
SetBusyRenderRate = ImGui_ImplRoblox_SetBusyRenderRate,
SetProfiling = ImGui_ImplRoblox_SetProfiling,
IsProfiling = ImGui_ImplRoblox_IsProfiling,
}
return true -- [Roblox] ModuleScripts must return exactly one value