Support additional main viewports

exuvo · May 2, 2021 · 58f6204 · 58f6204
1 parent 33cdbe9
commit 58f6204
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Showing 4 changed files with 57 additions and 17 deletions.
diff --git a/backends/imgui_impl_vulkan.cpp b/backends/imgui_impl_vulkan.cpp
@@ -1025,16 +1025,26 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass rend
 
     ImGui_ImplVulkan_CreateDeviceObjects();
 
-    // Our render function expect RendererUserData to be storing the window render buffer we need (for the main viewport we won't use ->Window)
-    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
-    main_viewport->RendererUserData = IM_NEW(ImGuiViewportDataVulkan)();
+    ImGui_ImplVulkan_InitViewport(ImGui::GetMainViewport());
 
     if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
         ImGui_ImplVulkan_InitPlatformInterface();
 
     return true;
 }
 
+void ImGui_ImplVulkan_InitViewport(ImGuiViewport* viewport) {
+	// Our render function expect RendererUserData to be storing the window render buffer we need (for the main viewport we won't use ->Window)
+	viewport->RendererUserData = IM_NEW(ImGuiViewportDataVulkan)();
+}
+
+void ImGui_ImplVulkan_ShutdownViewport(ImGuiViewport* viewport) {
+	if (ImGuiViewportDataVulkan* data = (ImGuiViewportDataVulkan*)viewport->RendererUserData) {
+		IM_DELETE(data);
+		viewport->RendererUserData = NULL;
+	}
+}
+
 void ImGui_ImplVulkan_Shutdown()
 {
     // First destroy objects in all viewports

diff --git a/backends/imgui_impl_vulkan.h b/backends/imgui_impl_vulkan.h
@@ -63,6 +63,8 @@ struct ImGui_ImplVulkan_InitInfo
 
 // Called by user code
 IMGUI_IMPL_API bool     ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass render_pass);
+IMGUI_IMPL_API void     ImGui_ImplVulkan_InitViewport(ImGuiViewport* viewport);
+IMGUI_IMPL_API void     ImGui_ImplVulkan_ShutdownViewport(ImGuiViewport* viewport);
 IMGUI_IMPL_API void     ImGui_ImplVulkan_Shutdown();
 IMGUI_IMPL_API void     ImGui_ImplVulkan_NewFrame();
 IMGUI_IMPL_API void     ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer command_buffer, VkPipeline pipeline = VK_NULL_HANDLE);

diff --git a/imgui.cpp b/imgui.cpp
@@ -937,7 +937,7 @@ static void             EndFrameDrawDimmedBackgrounds();
 
 // Viewports
 const ImGuiID           IMGUI_VIEWPORT_DEFAULT_ID = 0x11111111; // Using an arbitrary constant instead of e.g. ImHashStr("ViewportDefault", 0); so it's easier to spot in the debugger. The exact value doesn't matter.
-static ImGuiViewportP*  AddUpdateViewport(ImGuiWindow* window, ImGuiID id, const ImVec2& platform_pos, const ImVec2& size, ImGuiViewportFlags flags);
+ImGuiViewportP*  AddUpdateViewport(ImGuiWindow* window, ImGuiID id, const ImVec2& platform_pos, const ImVec2& size, ImGuiViewportFlags flags);
 static void             UpdateViewportsNewFrame();
 static void             UpdateViewportsEndFrame();
 static void             UpdateSelectWindowViewport(ImGuiWindow* window);
@@ -3491,11 +3491,15 @@ ImGuiPlatformIO& ImGui::GetPlatformIO()
 }
 
 // Pass this to your backend rendering function! Valid after Render() and until the next call to NewFrame()
-ImDrawData* ImGui::GetDrawData()
+ImDrawData* ImGui::GetDrawData(ImGuiViewport* viewport)
 {
-    ImGuiContext& g = *GImGui;
-    ImGuiViewportP* viewport = g.Viewports[0];
-    return viewport->DrawDataP.Valid ? &viewport->DrawDataP : NULL;
+	IM_ASSERT(viewport != NULL);
+	ImGuiViewportP* viewportP = (ImGuiViewportP*) viewport;
+	return viewportP->DrawDataP.Valid ? &viewportP->DrawDataP : NULL;
+}
+
+ImDrawData* ImGui::GetDrawData() {
+	return GetDrawData(ImGui::GetMainViewport());
 }
 
 double ImGui::GetTime()
@@ -11427,8 +11431,17 @@ static bool ImGui::UpdateTryMergeWindowIntoHostViewport(ImGuiWindow* window, ImG
 // FIXME: handle 0 to N host viewports
 static bool ImGui::UpdateTryMergeWindowIntoHostViewports(ImGuiWindow* window)
 {
-    ImGuiContext& g = *GImGui;
-    return UpdateTryMergeWindowIntoHostViewport(window, g.Viewports[0]);
+	ImGuiContext& g = *GImGui;
+
+	for (ImGuiViewportP* viewport : g.Viewports) {
+		if (viewport->Flags & ImGuiViewportFlags_CanHostOtherWindows) {
+			if (UpdateTryMergeWindowIntoHostViewport(window, viewport)) {
+				return true;
+			}
+		}
+	}
+
+	return false;
 }
 
 // Translate Dear ImGui windows when a Host Viewport has been moved
@@ -11686,13 +11699,19 @@ static void ImGui::UpdateViewportsEndFrame()
     {
         ImGuiViewportP* viewport = g.Viewports[i];
         viewport->LastPos = viewport->Pos;
-        if (viewport->LastFrameActive < g.FrameCount || viewport->Size.x <= 0.0f || viewport->Size.y <= 0.0f)
-            if (i > 0) // Always include main viewport in the list
-                continue;
+
+        if (viewport->LastFrameActive < g.FrameCount || viewport->Size.x <= 0.0f || viewport->Size.y <= 0.0f) {
+        	if ((viewport->Flags & (ImGuiViewportFlags_OwnedByApp | ImGuiViewportFlags_CanHostOtherWindows)) == 0)
+        		continue;
+        }
+
         if (viewport->Window && !IsWindowActiveAndVisible(viewport->Window))
             continue;
-        if (i > 0)
-            IM_ASSERT(viewport->Window != NULL);
+
+        if ((viewport->Flags & (ImGuiViewportFlags_OwnedByApp | ImGuiViewportFlags_CanHostOtherWindows)) == 0) {
+        	IM_ASSERT(viewport->Window != NULL);
+        }
+
         g.PlatformIO.Viewports.push_back(viewport);
     }
     g.Viewports[0]->ClearRequestFlags(); // Clear main viewport flags because UpdatePlatformWindows() won't do it and may not even be called
@@ -11905,6 +11924,10 @@ void ImGui::UpdatePlatformWindows()
     for (int i = 1; i < g.Viewports.Size; i++)
     {
         ImGuiViewportP* viewport = g.Viewports[i];
+
+        if (viewport->Flags & ImGuiViewportFlags_OwnedByApp) { // Avoid Create and destroy window for host windows viewports
+            continue;
+        }
 
         // Destroy platform window if the viewport hasn't been submitted or if it is hosting a hidden window
         // (the implicit/fallback Debug##Default window will be registering its viewport then be disabled, causing a dummy DestroyPlatformWindow to be made each frame)
@@ -12029,11 +12052,12 @@ void ImGui::UpdatePlatformWindows()
 //
 void ImGui::RenderPlatformWindowsDefault(void* platform_render_arg, void* renderer_render_arg)
 {
-    // Skip the main viewport (index 0), which is always fully handled by the application!
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     for (int i = 1; i < platform_io.Viewports.Size; i++)
     {
         ImGuiViewport* viewport = platform_io.Viewports[i];
+        if (viewport->Flags & ImGuiViewportFlags_OwnedByApp)
+            continue;
         if (viewport->Flags & ImGuiViewportFlags_Minimized)
             continue;
         if (platform_io.Platform_RenderWindow) platform_io.Platform_RenderWindow(viewport, platform_render_arg);
@@ -12042,6 +12066,8 @@ void ImGui::RenderPlatformWindowsDefault(void* platform_render_arg, void* render
     for (int i = 1; i < platform_io.Viewports.Size; i++)
     {
         ImGuiViewport* viewport = platform_io.Viewports[i];
+        if (viewport->Flags & ImGuiViewportFlags_OwnedByApp)
+            continue;
         if (viewport->Flags & ImGuiViewportFlags_Minimized)
             continue;
         if (platform_io.Platform_SwapBuffers) platform_io.Platform_SwapBuffers(viewport, platform_render_arg);
@@ -12130,7 +12156,8 @@ void ImGui::DestroyPlatformWindow(ImGuiViewportP* viewport)
     }
     else
     {
-        IM_ASSERT(viewport->RendererUserData == NULL && viewport->PlatformUserData == NULL && viewport->PlatformHandle == NULL);
+        if ((viewport->Flags & ImGuiViewportFlags_OwnedByApp) == 0)
+            IM_ASSERT(viewport->RendererUserData == NULL && viewport->PlatformUserData == NULL && viewport->PlatformHandle == NULL);
     }
     viewport->RendererUserData = viewport->PlatformUserData = viewport->PlatformHandle = NULL;
     viewport->ClearRequestFlags();

diff --git a/imgui.h b/imgui.h
@@ -280,6 +280,7 @@ namespace ImGui
     IMGUI_API void          EndFrame();                                 // ends the Dear ImGui frame. automatically called by Render(). If you don't need to render data (skipping rendering) you may call EndFrame() without Render()... but you'll have wasted CPU already! If you don't need to render, better to not create any windows and not call NewFrame() at all!
     IMGUI_API void          Render();                                   // ends the Dear ImGui frame, finalize the draw data. You can then get call GetDrawData().
     IMGUI_API ImDrawData*   GetDrawData();                              // valid after Render() and until the next call to NewFrame(). this is what you have to render.
+    IMGUI_API ImDrawData*   GetDrawData(ImGuiViewport* viewport);                              // valid after Render() and until the next call to NewFrame(). this is what you have to render.
 
     // Demo, Debug, Information
     IMGUI_API void          ShowDemoWindow(bool* p_open = NULL);        // create Demo window. demonstrate most ImGui features. call this to learn about the library! try to make it always available in your application!