Fixed issue 2600
Each window created in imgui_impl_win32.cpp now creates an openGL
context which shares its display list space with the primary window's.
IMGUI_IMPL_WIN32_OPENGL3 must be defined to use this fix.
diff --git a/backends/imgui_impl_win32.cpp b/backends/imgui_impl_win32.cpp
index 8b72e6e..8a581ec 100644
--- a/backends/imgui_impl_win32.cpp
+++ b/backends/imgui_impl_win32.cpp
@@ -89,6 +89,8 @@
static void ImGui_ImplWin32_InitPlatformInterface();
static void ImGui_ImplWin32_ShutdownPlatformInterface();
static void ImGui_ImplWin32_UpdateMonitors();
+static void ImGui_ImplWin32_SetWindowFocus(ImGuiViewport* viewport);
+static void ImGui_ImplWin32_ShowWindow(ImGuiViewport* viewport);
struct ImGui_ImplWin32_Data
{
@@ -101,6 +103,10 @@
ImGuiMouseCursor LastMouseCursor;
bool WantUpdateMonitors;
+#ifdef IMGUI_IMPL_WIN32_OPENGL3
+ HGLRC HgLrc;
+#endif //IMGUI_IMPL_WIN32_OPENGL3
+
#ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
bool HasGamepad;
bool WantUpdateHasGamepad;
@@ -122,7 +128,11 @@
}
// Functions
+#ifdef IMGUI_IMPL_WIN32_OPENGL3
+bool ImGui_ImplWin32_Init(void* hwnd, void* hglrc)
+#else
bool ImGui_ImplWin32_Init(void* hwnd)
+#endif
{
ImGuiIO& io = ImGui::GetIO();
IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
@@ -148,6 +158,10 @@
bd->Time = perf_counter;
bd->LastMouseCursor = ImGuiMouseCursor_COUNT;
+#ifdef IMGUI_IMPL_WIN32_OPENGL3
+ bd->HgLrc = (HGLRC)hglrc;
+#endif //IMGUI_IMPL_WIN32_OPENGL3
+
// Our mouse update function expect PlatformHandle to be filled for the main viewport
ImGuiViewport* main_viewport = ImGui::GetMainViewport();
main_viewport->PlatformHandle = main_viewport->PlatformHandleRaw = (void*)bd->hWnd;
@@ -899,8 +913,23 @@
bool HwndOwned;
DWORD DwStyle;
DWORD DwExStyle;
+#ifdef IMGUI_IMPL_WIN32_OPENGL3
+ HDC Hdc;
+ HGLRC HgLrc;
+#endif
- ImGui_ImplWin32_ViewportData() { Hwnd = nullptr; HwndOwned = false; DwStyle = DwExStyle = 0; }
+ ImGui_ImplWin32_ViewportData()
+ {
+ Hwnd = nullptr;
+ HwndOwned = false;
+ DwStyle = 0;
+ DwExStyle = 0;
+
+#ifdef IMGUI_IMPL_WIN32_OPENGL3
+ Hdc = nullptr;
+ HgLrc = nullptr;
+#endif //IMGUI_IMPL_WIN32_OPENGL3
+ }
~ImGui_ImplWin32_ViewportData() { IM_ASSERT(Hwnd == nullptr); }
};
@@ -942,6 +971,27 @@
vd->HwndOwned = true;
viewport->PlatformRequestResize = false;
viewport->PlatformHandle = viewport->PlatformHandleRaw = vd->Hwnd;
+
+#ifdef IMGUI_IMPL_WIN32_OPENGL3
+ vd->Hdc = GetDC(vd->Hwnd);
+ ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+
+ // Set pixel format to match base window
+ HDC Hdc = GetDC(bd->hWnd);
+ int pf = GetPixelFormat(Hdc);
+ PIXELFORMATDESCRIPTOR pfd;
+ DescribePixelFormat(Hdc, pf, sizeof(pfd), &pfd);
+ SetPixelFormat(vd->Hdc, pf, &pfd);
+
+ // Create OpenGL context for new window
+ vd->HgLrc = wglCreateContext(vd->Hdc);
+ wglMakeCurrent(vd->Hdc, vd->HgLrc);
+ wglShareLists(bd->HgLrc, vd->HgLrc);
+
+ // Present new window
+ ImGui_ImplWin32_SetWindowFocus(viewport);
+ ImGui_ImplWin32_ShowWindow(viewport);
+#endif //IMGUI_IMPL_WIN32_OPENGL3
}
static void ImGui_ImplWin32_DestroyWindow(ImGuiViewport* viewport)
@@ -956,7 +1006,13 @@
::SetCapture(bd->hWnd);
}
if (vd->Hwnd && vd->HwndOwned)
+ {
+ #ifdef IMGUI_IMPL_WIN32_OPENGL3
+ wglDeleteContext(vd->HgLrc);
+ #endif
+
::DestroyWindow(vd->Hwnd);
+ }
vd->Hwnd = nullptr;
IM_DELETE(vd);
}
@@ -1116,6 +1172,21 @@
#endif
}
+#ifdef IMGUI_IMPL_WIN32_OPENGL3
+static void ImGui_ImplWin32_RenderWindow(ImGuiViewport* viewport, void*)
+{
+ ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+ wglMakeCurrent(vd->Hdc, vd->HgLrc);
+}
+
+static void ImGui_ImplWin32_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+ ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+ wglMakeCurrent(vd->Hdc, vd->HgLrc);
+ SwapBuffers(vd->Hdc);
+}
+#endif //IMGUI_IMPL_WIN32_OPENGL3
+
static LRESULT CALLBACK ImGui_ImplWin32_WndProcHandler_PlatformWindow(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
@@ -1125,6 +1196,10 @@
{
switch (msg)
{
+#ifdef IMGUI_IMPL_WIN32_OPENGL3
+ case WM_ERASEBKGND:
+ return 0; // Prevent flickering on window invalidation
+#endif //IMGUI_IMPL_WIN32_OPENGL3
case WM_CLOSE:
viewport->PlatformRequestClose = true;
return 0;
@@ -1189,6 +1264,11 @@
platform_io.Platform_GetWindowDpiScale = ImGui_ImplWin32_GetWindowDpiScale; // FIXME-DPI
platform_io.Platform_OnChangedViewport = ImGui_ImplWin32_OnChangedViewport; // FIXME-DPI
+#ifdef IMGUI_IMPL_WIN32_OPENGL3
+ platform_io.Platform_RenderWindow = ImGui_ImplWin32_RenderWindow;
+ platform_io.Platform_SwapBuffers = ImGui_ImplWin32_SwapBuffers;
+#endif //IMGUI_IMPL_WIN32_OPENGL3
+
// Register main window handle (which is owned by the main application, not by us)
// This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
ImGuiViewport* main_viewport = ImGui::GetMainViewport();
diff --git a/backends/imgui_impl_win32.h b/backends/imgui_impl_win32.h
index 5378c7c..d65a11d 100644
--- a/backends/imgui_impl_win32.h
+++ b/backends/imgui_impl_win32.h
@@ -17,7 +17,11 @@
#pragma once
#include "imgui.h" // IMGUI_IMPL_API
+#ifdef IMGUI_IMPL_WIN32_OPENGL3
+IMGUI_IMPL_API bool ImGui_ImplWin32_Init(void* hwnd, void* hglrc);
+#else
IMGUI_IMPL_API bool ImGui_ImplWin32_Init(void* hwnd);
+#endif
IMGUI_IMPL_API void ImGui_ImplWin32_Shutdown();
IMGUI_IMPL_API void ImGui_ImplWin32_NewFrame();
