Examples: Metal: Wrap main event loop body in an @autoreleasepool block to ensure allocations get freed even if underlying system event loop gets paused due to app nap (#2910, #2917)

docs/CHANGELOG.txt

@@ -37,6 +37,8 @@ Other Changes:
 - Misc: Added ImGuiMouseCursor_NotAllowed enum so it can be used by more shared widgets. [@rokups]
 - Backends: GLFW, SDL, Win32, OSX, Allegro: Added support for ImGuiMouseCursor_NotAllowed. [@rokups]
 - Backends: GLFW: Added support for the missing mouse cursors newly added in GLFW 3.4+. [@rokups]
+- Examples: Metal: Wrapped main loop in @autoreleasepool block to ensure allocations get freed
+  even if underlying system event loop gets paused due to app nap (#2910, #2917). [@bear24rw]
 
 
 -----------------------------------------------------------------------

examples/example_glfw_metal/main.mm

@@ -82,77 +82,80 @@ int main(int, char**)
     // Main loop
     while (!glfwWindowShouldClose(window))
     {
-        // Poll and handle events (inputs, window resize, etc.)
-        // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
-        // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
-        // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
-        // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-        glfwPollEvents();
-
-        int width, height;
-        glfwGetFramebufferSize(window, &width, &height);
-        layer.drawableSize = CGSizeMake(width, height);
-        id<CAMetalDrawable> drawable = [layer nextDrawable];
-
-        id<MTLCommandBuffer> commandBuffer = [commandQueue commandBuffer];
-        renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(clear_color[0], clear_color[1], clear_color[2], clear_color[3]);
-        renderPassDescriptor.colorAttachments[0].texture = drawable.texture;
-        renderPassDescriptor.colorAttachments[0].loadAction = MTLLoadActionClear;
-        renderPassDescriptor.colorAttachments[0].storeAction = MTLStoreActionStore;
-        id <MTLRenderCommandEncoder> renderEncoder = [commandBuffer renderCommandEncoderWithDescriptor:renderPassDescriptor];
-        [renderEncoder pushDebugGroup:@"ImGui demo"];
-
-        // Start the Dear ImGui frame
-        ImGui_ImplMetal_NewFrame(renderPassDescriptor);
-        ImGui_ImplGlfw_NewFrame();
-        ImGui::NewFrame();
-
-        // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
-        if (show_demo_window)
-            ImGui::ShowDemoWindow(&show_demo_window);
-
-        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to created a named window.
+        @autoreleasepool
         {
-            static float f = 0.0f;
-            static int counter = 0;
-
-            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
-
-            ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
-            ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
-            ImGui::Checkbox("Another Window", &show_another_window);
-
-            ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
-            ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
-
-            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
-                counter++;
-            ImGui::SameLine();
-            ImGui::Text("counter = %d", counter);
-
-            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
-            ImGui::End();
+            // Poll and handle events (inputs, window resize, etc.)
+            // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
+            // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
+            // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
+            // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
+            glfwPollEvents();
+
+            int width, height;
+            glfwGetFramebufferSize(window, &width, &height);
+            layer.drawableSize = CGSizeMake(width, height);
+            id<CAMetalDrawable> drawable = [layer nextDrawable];
+
+            id<MTLCommandBuffer> commandBuffer = [commandQueue commandBuffer];
+            renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(clear_color[0], clear_color[1], clear_color[2], clear_color[3]);
+            renderPassDescriptor.colorAttachments[0].texture = drawable.texture;
+            renderPassDescriptor.colorAttachments[0].loadAction = MTLLoadActionClear;
+            renderPassDescriptor.colorAttachments[0].storeAction = MTLStoreActionStore;
+            id <MTLRenderCommandEncoder> renderEncoder = [commandBuffer renderCommandEncoderWithDescriptor:renderPassDescriptor];
+            [renderEncoder pushDebugGroup:@"ImGui demo"];
+
+            // Start the Dear ImGui frame
+            ImGui_ImplMetal_NewFrame(renderPassDescriptor);
+            ImGui_ImplGlfw_NewFrame();
+            ImGui::NewFrame();
+
+            // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
+            if (show_demo_window)
+                ImGui::ShowDemoWindow(&show_demo_window);
+
+            // 2. Show a simple window that we create ourselves. We use a Begin/End pair to created a named window.
+            {
+                static float f = 0.0f;
+                static int counter = 0;
+
+                ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+
+                ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
+                ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
+                ImGui::Checkbox("Another Window", &show_another_window);
+
+                ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
+                ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
+
+                if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+                    counter++;
+                ImGui::SameLine();
+                ImGui::Text("counter = %d", counter);
+
+                ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
+                ImGui::End();
+            }
+
+            // 3. Show another simple window.
+            if (show_another_window)
+            {
+                ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
+                ImGui::Text("Hello from another window!");
+                if (ImGui::Button("Close Me"))
+                    show_another_window = false;
+                ImGui::End();
+            }
+
+            // Rendering
+            ImGui::Render();
+            ImGui_ImplMetal_RenderDrawData(ImGui::GetDrawData(), commandBuffer, renderEncoder);
+
+            [renderEncoder popDebugGroup];
+            [renderEncoder endEncoding];
+
+            [commandBuffer presentDrawable:drawable];
+            [commandBuffer commit];
         }
-
-        // 3. Show another simple window.
-        if (show_another_window)
-        {
-            ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
-            ImGui::Text("Hello from another window!");
-            if (ImGui::Button("Close Me"))
-                show_another_window = false;
-            ImGui::End();
-        }
-
-        // Rendering
-        ImGui::Render();
-        ImGui_ImplMetal_RenderDrawData(ImGui::GetDrawData(), commandBuffer, renderEncoder);
-
-        [renderEncoder popDebugGroup];
-        [renderEncoder endEncoding];
-
-        [commandBuffer presentDrawable:drawable];
-        [commandBuffer commit];
     }
 
     // Cleanup