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
parent 2558c30d32
commit 7eb7d5fcbb
5 changed files with 105 additions and 5 deletions
@@ -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)