docking: fix docked bg + dock-host moving; per-function @native to fit Roblox codegen limit

tools/bundle.py

@@ -20,7 +20,7 @@ for src in FILES.values():
     names.update(re.findall(r"^function ([A-Za-z_]\w*)\s*\(", src, re.M))
     names.update(re.findall(r"^([A-Za-z_]\w*)\s*=[^=]", src, re.M))
 
-out = ["--!native", "--!optimize 2", "-- GENERATED by tools/bundle.py from imgui/*.lua - do not edit", "",
+out = ["--!optimize 2", "-- GENERATED by tools/bundle.py from imgui/*.lua - do not edit", "",
        "local __FILES, __LOADED = {}, {}",
        "function IM_INCLUDE(name)",
        "    local r = __LOADED[name]",

tools/test/scripts/t_dock_move.luau

@@ -0,0 +1,59 @@
+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, last_down, host0 = 0, false, nil
+local function lerp(a, b, t) return a + (b - a) * t end
+local function script(f)
+    if f < 6 then return 600, 108, false end
+    if f == 6 then return 600, 108, true end
+    if f <= 20 then local t = (f - 6) / 14 return lerp(600, 250, t), lerp(108, 190, t), true end
+    if f <= 27 then return 250, 190, true end
+    if f <= 40 then return 250, 190, false end
+    -- now grab empty space of the shared tab bar (right of the tabs) and move
+    if f == 41 then return 380, 108, false end
+    if f == 42 then return 380, 108, true end
+    if f <= 56 then local t = (f - 42) / 14 return lerp(380, 600, t), lerp(108, 300, t), true end
+    return 600, 300, false
+end
+RunService.Stepped:Connect(function()
+    frame += 1
+    G.ImGui_ImplRoblox.NewFrame()
+    local x, y, down = script(frame)
+    io:AddMousePosEvent(x, y)
+    if down ~= last_down then io:AddMouseButtonEvent(0, down); last_down = down end
+    ImGui.NewFrame()
+    for i, n in ipairs({"A", "B"}) do
+        ImGui.SetNextWindowPos(ImVec2(100 + (i - 1) * 400, 100), G.ImGuiCond.FirstUseEver)
+        ImGui.SetNextWindowSize(ImVec2(300, 200), G.ImGuiCond.FirstUseEver)
+        if ImGui.Begin(n) then ImGui.Text("window " .. n) end
+        ImGui.End()
+    end
+    local a = ImGui.FindWindowByName("A")
+    if frame == 40 then
+        assert(a.DockNode and a.DockNode.Windows.Size == 2, "docked")
+        host0 = {Pos = {x = a.DockNode.HostWindow.Pos.x, y = a.DockNode.HostWindow.Pos.y}}
+        print("host before", host0.Pos.x, host0.Pos.y)
+    end
+    if frame == 70 then
+        local h = a.DockNode.HostWindow
+        print("host after", h.Pos.x, h.Pos.y)
+        assert(math.abs(h.Pos.x - host0.Pos.x) > 100 or math.abs(h.Pos.y - host0.Pos.y) > 50, "dock host must move")
+        -- background: host draw list must contain a filled rect covering the node body
+    end
+    ImGui.Render()
+    G.ImGui_ImplRoblox.RenderDrawData(ImGui.GetDrawData())
+    if frame == 70 then
+        local want = ImGui.GetColorU32(G.ImGuiCol.WindowBg)
+        local found = false
+        for _, l in ImGui.GetDrawData().CmdLists:iter() do
+            for i = 1, l.VtxBuffer.Size do if l.VtxBuffer.Data[i][3] == want then found = true break end end
+        end
+        assert(found, "docked windows must draw a WindowBg background")
+        print("MOVE OK")
+    end
+end)