Revert most of "Examples: refactor all examples with a MainLoopStep() function..." (#2492, #3699)"

This reverts commit 96ab68eee0.

# Conflicts:
#	docs/CHANGELOG.txt
#	examples/example_glfw_opengl3/main.cpp
#	examples/example_sdl_opengl3/main.cpp

docs/CHANGELOG.txt

@@ -97,11 +97,7 @@ All changes:
   the 'window' parameter. (#6142)
 - Backends: WebGPU: Fix building for latest WebGPU specs (remove implicit layout generation).
   (#6117, #4116, #3632) [@tonygrue, @bfierz]
-- Examples: refactord all examples to use a "MainLoopStep()" function. This is in order
-  to be able to trivially make some compile with Emscripten. (#2492, #3699)
-  While not all examples are expected to compile on Emscripten, we try to keep all of them
-  as close as possible to each others.
-- Examples: Emscripten: The main SDL+GL and GLFW+GL examples now supports Emscripten.
+- Examples: refactored SDL+GL and GLFW+GL examples to compile with Emscripten.
   (the dedicated example_emscripten_opengl3/ has been removed) (#2492, #2494, #3699, #3705)
 - Examples: Win32: Fixed examples using RegisterClassW() since 1.89 to also call
   DefWindowProcW() instead of DefWindowProc() so that title text are correctly converted

examples/example_allegro5/main.cpp

@@ -16,10 +16,6 @@
 #include "imgui.h"
 #include "imgui_impl_allegro5.h"
 
-// Forward declarations of helper functions
-bool MainLoopStep(ALLEGRO_DISPLAY* display, ALLEGRO_EVENT_QUEUE* queue);
-
-// Main code
 int main(int, char**)
 {
     // Setup Allegro
@@ -27,8 +23,6 @@ int main(int, char**)
     al_install_keyboard();
     al_install_mouse();
     al_init_primitives_addon();
-
-    // Create window with graphics context and event queue
     al_set_new_display_flags(ALLEGRO_RESIZABLE);
     ALLEGRO_DISPLAY* display = al_create_display(1280, 720);
     al_set_window_title(display, "Dear ImGui Allegro 5 example");
@@ -66,36 +60,25 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
-    // Main loop
-    while (true)
-    {
-        if (!MainLoopStep(display, queue))
-            break;
-    }
-
-    // Cleanup
-    ImGui_ImplAllegro5_Shutdown();
-    ImGui::DestroyContext();
-    al_destroy_event_queue(queue);
-    al_destroy_display(display);
-
-    return 0;
-}
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
-bool MainLoopStep(ALLEGRO_DISPLAY* display, ALLEGRO_EVENT_QUEUE* queue)
+    // Main loop
+    bool running = true;
+    while (running)
     {
         // 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, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-    bool done = false;
         ALLEGRO_EVENT ev;
         while (al_get_next_event(queue, &ev))
         {
             ImGui_ImplAllegro5_ProcessEvent(&ev);
             if (ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
-            done = true;
+                running = false;
             if (ev.type == ALLEGRO_EVENT_DISPLAY_RESIZE)
             {
                 ImGui_ImplAllegro5_InvalidateDeviceObjects();
@@ -103,19 +86,11 @@ bool MainLoopStep(ALLEGRO_DISPLAY* display, ALLEGRO_EVENT_QUEUE* queue)
                 ImGui_ImplAllegro5_CreateDeviceObjects();
             }
         }
-    if (done)
-        return false;
 
         // Start the Dear ImGui frame
         ImGui_ImplAllegro5_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -158,6 +133,13 @@ bool MainLoopStep(ALLEGRO_DISPLAY* display, ALLEGRO_EVENT_QUEUE* queue)
         al_clear_to_color(al_map_rgba_f(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w));
         ImGui_ImplAllegro5_RenderDrawData(ImGui::GetDrawData());
         al_flip_display();
+    }
+
+    // Cleanup
+    ImGui_ImplAllegro5_Shutdown();
+    ImGui::DestroyContext();
+    al_destroy_event_queue(queue);
+    al_destroy_display(display);
 
-    return true;
+    return 0;
 }

examples/example_glfw_opengl2/main.cpp

@@ -23,11 +23,6 @@
 #pragma comment(lib, "legacy_stdio_definitions")
 #endif
 
-// Data
-static GLFWwindow* g_AppWindow = NULL;
-
-// Forward declarations of helper functions
-void MainLoopStep();
 static void glfw_error_callback(int error, const char* description)
 {
     fprintf(stderr, "GLFW Error %d: %s\n", error, description);
@@ -46,7 +41,6 @@ int main(int, char**)
         return 1;
     glfwMakeContextCurrent(window);
     glfwSwapInterval(1); // Enable vsync
-    g_AppWindow = window;
 
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
@@ -79,29 +73,19 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
+
     // Main loop
     while (!glfwWindowShouldClose(window))
-        MainLoopStep();
-
-    // Cleanup
-    ImGui_ImplOpenGL2_Shutdown();
-    ImGui_ImplGlfw_Shutdown();
-    ImGui::DestroyContext();
-
-    glfwDestroyWindow(window);
-    glfwTerminate();
-
-    return 0;
-}
-
-void MainLoopStep()
     {
         // 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, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-    GLFWwindow* window = g_AppWindow;
         glfwPollEvents();
 
         // Start the Dear ImGui frame
@@ -109,12 +93,6 @@ void MainLoopStep()
         ImGui_ImplGlfw_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -171,3 +149,14 @@ void MainLoopStep()
         glfwMakeContextCurrent(window);
         glfwSwapBuffers(window);
     }
+
+    // Cleanup
+    ImGui_ImplOpenGL2_Shutdown();
+    ImGui_ImplGlfw_Shutdown();
+    ImGui::DestroyContext();
+
+    glfwDestroyWindow(window);
+    glfwTerminate();
+
+    return 0;
+}

examples/example_glfw_opengl3/main.cpp

@@ -3,8 +3,6 @@
 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
 // Read online: https://github.com/ocornut/imgui/tree/master/docs
 
-// This example can also compile and run with Emscripten. See Makefile.emscripten for details.
-
 #include "imgui.h"
 #include "imgui_impl_glfw.h"
 #include "imgui_impl_opengl3.h"
@@ -22,16 +20,6 @@
 #pragma comment(lib, "legacy_stdio_definitions")
 #endif
 
-// Data
-static GLFWwindow* g_AppWindow = NULL;
-
-// Forward declarations of helper functions
-void MainLoopStep();
-#ifdef __EMSCRIPTEN__
-#include <emscripten.h>
-void MainLoopForEmscripten(void*) { MainLoopStep(); }
-#endif
-
 static void glfw_error_callback(int error, const char* description)
 {
     fprintf(stderr, "GLFW Error %d: %s\n", error, description);
@@ -73,7 +61,6 @@ int main(int, char**)
         return 1;
     glfwMakeContextCurrent(window);
     glfwSwapInterval(1); // Enable vsync
-    g_AppWindow = window;
 
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
@@ -98,7 +85,6 @@ int main(int, char**)
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
     // - Read 'docs/FONTS.md' for more instructions and details.
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
-    // - Our Emscripten build process allows embedding fonts to be accessible at runtime from the "fonts/" folder. See Makefile.emscripten for details.
     //io.Fonts->AddFontDefault();
     //io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
     //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
@@ -107,38 +93,19 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
+
     // Main loop
-#ifndef __EMSCRIPTEN__
-    // Desktop Build
     while (!glfwWindowShouldClose(window))
-        MainLoopStep();
-#else
-    // Emscripten Build
-    // For an Emscripten build we are disabling file-system access, so let's not attempt to do a fopen() of the imgui.ini file.
-    // You may manually call LoadIniSettingsFromMemory() to load settings from your own storage.
-    io.IniFilename = NULL;
-    emscripten_set_main_loop_arg(MainLoopForEmscripten, NULL, 0, true);
-#endif
-
-    // Cleanup
-    ImGui_ImplOpenGL3_Shutdown();
-    ImGui_ImplGlfw_Shutdown();
-    ImGui::DestroyContext();
-
-    glfwDestroyWindow(window);
-    glfwTerminate();
-
-    return 0;
-}
-
-void MainLoopStep()
     {
         // 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, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-    GLFWwindow* window = g_AppWindow;
         glfwPollEvents();
 
         // Start the Dear ImGui frame
@@ -146,12 +113,6 @@ void MainLoopStep()
         ImGui_ImplGlfw_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -200,3 +161,14 @@ void MainLoopStep()
 
         glfwSwapBuffers(window);
     }
+
+    // Cleanup
+    ImGui_ImplOpenGL3_Shutdown();
+    ImGui_ImplGlfw_Shutdown();
+    ImGui::DestroyContext();
+
+    glfwDestroyWindow(window);
+    glfwTerminate();
+
+    return 0;
+}

examples/example_glfw_vulkan/main.cpp

@@ -42,13 +42,10 @@ static VkDebugReportCallbackEXT g_DebugReport = VK_NULL_HANDLE;
 static VkPipelineCache          g_PipelineCache = VK_NULL_HANDLE;
 static VkDescriptorPool         g_DescriptorPool = VK_NULL_HANDLE;
 
-static GLFWwindow*              g_AppWindow = NULL;
 static ImGui_ImplVulkanH_Window g_MainWindowData;
 static int                      g_MinImageCount = 2;
 static bool                     g_SwapChainRebuild = false;
 
-// Forward declarations of helper functions
-void MainLoopStep();
 static void glfw_error_callback(int error, const char* description)
 {
     fprintf(stderr, "GLFW Error %d: %s\n", error, description);
@@ -373,7 +370,6 @@ int main(int, char**)
     uint32_t extensions_count = 0;
     const char** extensions = glfwGetRequiredInstanceExtensions(&extensions_count);
     SetupVulkan(extensions, extensions_count);
-    g_AppWindow = window;
 
     // Create Window Surface
     VkSurfaceKHR surface;
@@ -461,34 +457,19 @@ int main(int, char**)
         ImGui_ImplVulkan_DestroyFontUploadObjects();
     }
 
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
+
     // Main loop
     while (!glfwWindowShouldClose(window))
-        MainLoopStep();
-
-    // Cleanup
-    err = vkDeviceWaitIdle(g_Device);
-    check_vk_result(err);
-    ImGui_ImplVulkan_Shutdown();
-    ImGui_ImplGlfw_Shutdown();
-    ImGui::DestroyContext();
-
-    CleanupVulkanWindow();
-    CleanupVulkan();
-
-    glfwDestroyWindow(window);
-    glfwTerminate();
-
-    return 0;
-}
-
-void MainLoopStep()
     {
         // 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, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-    GLFWwindow* window = g_AppWindow;
         glfwPollEvents();
 
         // Resize swap chain?
@@ -510,12 +491,6 @@ void MainLoopStep()
         ImGui_ImplGlfw_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -559,7 +534,6 @@ void MainLoopStep()
         const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);
         if (!is_minimized)
         {
-        ImGui_ImplVulkanH_Window* wd = &g_MainWindowData;
             wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
             wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
             wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
@@ -568,3 +542,19 @@ void MainLoopStep()
             FramePresent(wd);
         }
     }
+
+    // Cleanup
+    err = vkDeviceWaitIdle(g_Device);
+    check_vk_result(err);
+    ImGui_ImplVulkan_Shutdown();
+    ImGui_ImplGlfw_Shutdown();
+    ImGui::DestroyContext();
+
+    CleanupVulkanWindow();
+    CleanupVulkan();
+
+    glfwDestroyWindow(window);
+    glfwTerminate();
+
+    return 0;
+}

examples/example_sdl_directx11/main.cpp

@@ -12,14 +12,12 @@
 #include <SDL_syswm.h>
 
 // Data
-static SDL_Window*              g_AppWindow = NULL;
 static ID3D11Device*            g_pd3dDevice = NULL;
 static ID3D11DeviceContext*     g_pd3dDeviceContext = NULL;
 static IDXGISwapChain*          g_pSwapChain = NULL;
 static ID3D11RenderTargetView*  g_mainRenderTargetView = NULL;
 
 // Forward declarations of helper functions
-bool MainLoopStep();
 bool CreateDeviceD3D(HWND hWnd);
 void CleanupDeviceD3D();
 void CreateRenderTarget();
@@ -44,7 +42,6 @@ int main(int, char**)
     SDL_VERSION(&wmInfo.version);
     SDL_GetWindowWMInfo(window, &wmInfo);
     HWND hwnd = (HWND)wmInfo.info.win.window;
-    g_AppWindow = window;
 
     // Initialize Direct3D
     if (!CreateDeviceD3D(hwnd))
@@ -84,41 +81,28 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
-    // Main loop
-    while (true)
-    {
-        if (!MainLoopStep())
-            break;
-    }
-
-    // Cleanup
-    ImGui_ImplDX11_Shutdown();
-    ImGui_ImplSDL2_Shutdown();
-    ImGui::DestroyContext();
-
-    CleanupDeviceD3D();
-    SDL_DestroyWindow(window);
-    SDL_Quit();
-
-    return 0;
-}
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
-bool MainLoopStep()
+    // Main loop
+    bool done = false;
+    while (!done)
     {
-    // Poll and handle SDL events (inputs, window resize, etc.)
+        // 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, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-    SDL_Window* window = g_AppWindow;
         SDL_Event event;
         while (SDL_PollEvent(&event))
         {
             ImGui_ImplSDL2_ProcessEvent(&event);
             if (event.type == SDL_QUIT)
-            return false;
+                done = true;
             if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
-            return false;
+                done = true;
             if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_RESIZED && event.window.windowID == SDL_GetWindowID(window))
             {
                 // Release all outstanding references to the swap chain's buffers before resizing.
@@ -133,12 +117,6 @@ bool MainLoopStep()
         ImGui_ImplSDL2_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -182,10 +160,21 @@ bool MainLoopStep()
         g_pd3dDeviceContext->OMSetRenderTargets(1, &g_mainRenderTargetView, NULL);
         g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
         ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
+
         g_pSwapChain->Present(1, 0); // Present with vsync
         //g_pSwapChain->Present(0, 0); // Present without vsync
+    }
 
-    return true;
+    // Cleanup
+    ImGui_ImplDX11_Shutdown();
+    ImGui_ImplSDL2_Shutdown();
+    ImGui::DestroyContext();
+
+    CleanupDeviceD3D();
+    SDL_DestroyWindow(window);
+    SDL_Quit();
+
+    return 0;
 }
 
 // Helper functions to use DirectX11

examples/example_sdl_opengl2/main.cpp

@@ -14,12 +14,6 @@
 #include <SDL.h>
 #include <SDL_opengl.h>
 
-// Data
-static SDL_Window* g_AppWindow = NULL;
-
-// Forward declarations of helper functions
-bool MainLoopStep();
-
 // Main code
 int main(int, char**)
 {
@@ -41,7 +35,6 @@ int main(int, char**)
     SDL_GLContext gl_context = SDL_GL_CreateContext(window);
     SDL_GL_MakeCurrent(window, gl_context);
     SDL_GL_SetSwapInterval(1); // Enable vsync
-    g_AppWindow = window;
 
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
@@ -74,55 +67,35 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
-    // Main loop
-    while (true)
-    {
-        if (!MainLoopStep())
-            break;
-    }
-
-    // Cleanup
-    ImGui_ImplOpenGL2_Shutdown();
-    ImGui_ImplSDL2_Shutdown();
-    ImGui::DestroyContext();
-
-    SDL_GL_DeleteContext(gl_context);
-    SDL_DestroyWindow(window);
-    SDL_Quit();
-
-    return 0;
-}
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
-bool MainLoopStep()
+    // Main loop
+    bool done = false;
+    while (!done)
     {
-    // Poll and handle SDL events (inputs, window resize, etc.)
+        // 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, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-    SDL_Window* window = g_AppWindow;
         SDL_Event event;
         while (SDL_PollEvent(&event))
         {
             ImGui_ImplSDL2_ProcessEvent(&event);
             if (event.type == SDL_QUIT)
-            return false;
+                done = true;
             if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
-            return false;
+                done = true;
         }
 
         // Start the Dear ImGui frame
-    ImGuiIO& io = ImGui::GetIO();
         ImGui_ImplOpenGL2_NewFrame();
         ImGui_ImplSDL2_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -168,6 +141,16 @@ bool MainLoopStep()
         //glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context where shaders may be bound
         ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
         SDL_GL_SwapWindow(window);
+    }
+
+    // Cleanup
+    ImGui_ImplOpenGL2_Shutdown();
+    ImGui_ImplSDL2_Shutdown();
+    ImGui::DestroyContext();
+
+    SDL_GL_DeleteContext(gl_context);
+    SDL_DestroyWindow(window);
+    SDL_Quit();
 
-    return true;
+    return 0;
 }

examples/example_sdl_opengl3/main.cpp

@@ -3,8 +3,6 @@
 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
 // Read online: https://github.com/ocornut/imgui/tree/master/docs
 
-// This example can also compile and run with Emscripten. See Makefile.emscripten for details.
-
 #include "imgui.h"
 #include "imgui_impl_sdl.h"
 #include "imgui_impl_opengl3.h"
@@ -16,16 +14,6 @@
 #include <SDL_opengl.h>
 #endif
 
-// Data
-static SDL_Window* g_AppWindow = NULL;
-
-// Forward declarations of helper functions
-bool MainLoopStep();
-#ifdef __EMSCRIPTEN__
-#include <emscripten.h>
-void MainLoopForEmscripten(void*) { MainLoopStep(); }
-#endif
-
 // Main code
 int main(int, char**)
 {
@@ -69,7 +57,6 @@ int main(int, char**)
     SDL_GLContext gl_context = SDL_GL_CreateContext(window);
     SDL_GL_MakeCurrent(window, gl_context);
     SDL_GL_SetSwapInterval(1); // Enable vsync
-    g_AppWindow = window;
 
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
@@ -94,7 +81,6 @@ int main(int, char**)
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
     // - Read 'docs/FONTS.md' for more instructions and details.
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
-    // - Our Emscripten build process allows embedding fonts to be accessible at runtime from the "fonts/" folder. See Makefile.emscripten for details.
     //io.Fonts->AddFontDefault();
     //io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
     //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
@@ -103,64 +89,35 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
-    // Main loop
-#ifndef __EMSCRIPTEN__
-    // Desktop Build
-    while (true)
-    {
-        if (!MainLoopStep())
-            break;
-    }
-#else
-    // Emscripten Build
-    // For an Emscripten build we are disabling file-system access, so let's not attempt to do a fopen() of the imgui.ini file.
-    // You may manually call LoadIniSettingsFromMemory() to load settings from your own storage.
-    io.IniFilename = NULL;
-    emscripten_set_main_loop_arg(MainLoopForEmscripten, NULL, 0, true);
-#endif
-
-    // Cleanup
-    ImGui_ImplOpenGL3_Shutdown();
-    ImGui_ImplSDL2_Shutdown();
-    ImGui::DestroyContext();
-
-    SDL_GL_DeleteContext(gl_context);
-    SDL_DestroyWindow(window);
-    SDL_Quit();
-
-    return 0;
-}
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
-bool MainLoopStep()
+    // Main loop
+    bool done = false;
+    while (!done)
     {
-    // Poll and handle SDL events (inputs, window resize, etc.)
+        // 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, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-    SDL_Window* window = g_AppWindow;
         SDL_Event event;
         while (SDL_PollEvent(&event))
         {
             ImGui_ImplSDL2_ProcessEvent(&event);
             if (event.type == SDL_QUIT)
-            return false;
+                done = true;
             if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
-            return false;
+                done = true;
         }
 
         // Start the Dear ImGui frame
-    ImGuiIO& io = ImGui::GetIO();
         ImGui_ImplOpenGL3_NewFrame();
         ImGui_ImplSDL2_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -205,6 +162,16 @@ bool MainLoopStep()
         glClear(GL_COLOR_BUFFER_BIT);
         ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
         SDL_GL_SwapWindow(window);
+    }
+
+    // Cleanup
+    ImGui_ImplOpenGL3_Shutdown();
+    ImGui_ImplSDL2_Shutdown();
+    ImGui::DestroyContext();
 
-    return true;
+    SDL_GL_DeleteContext(gl_context);
+    SDL_DestroyWindow(window);
+    SDL_Quit();
+
+    return 0;
 }

examples/example_sdl_sdlrenderer/main.cpp

@@ -17,13 +17,6 @@
 #error This backend requires SDL 2.0.17+ because of SDL_RenderGeometry() function
 #endif
 
-// Data
-static SDL_Window*      g_AppWindow = NULL;
-static SDL_Renderer*    g_AppWindowRenderer = NULL;
-
-// Forward declarations of helper functions
-bool MainLoopStep();
-
 // Main code
 int main(int, char**)
 {
@@ -43,8 +36,6 @@ int main(int, char**)
         SDL_Log("Error creating SDL_Renderer!");
         return 0;
     }
-    g_AppWindow = window;
-    g_AppWindowRenderer = renderer;
     //SDL_RendererInfo info;
     //SDL_GetRendererInfo(renderer, &info);
     //SDL_Log("Current SDL_Renderer: %s", info.name);
@@ -80,56 +71,35 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
-    // Main loop
-    while (true)
-    {
-        if (!MainLoopStep())
-            break;
-    }
-
-    // Cleanup
-    ImGui_ImplSDLRenderer_Shutdown();
-    ImGui_ImplSDL2_Shutdown();
-    ImGui::DestroyContext();
-
-    SDL_DestroyRenderer(renderer);
-    SDL_DestroyWindow(window);
-    SDL_Quit();
-
-    return 0;
-}
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
-bool MainLoopStep()
+    // Main loop
+    bool done = false;
+    while (!done)
     {
         // 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, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-    SDL_Window* window = g_AppWindow;
-    SDL_Renderer* renderer = g_AppWindowRenderer;
         SDL_Event event;
         while (SDL_PollEvent(&event))
         {
             ImGui_ImplSDL2_ProcessEvent(&event);
             if (event.type == SDL_QUIT)
-            return false;
+                done = true;
             if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
-            return false;
+                done = true;
         }
 
         // Start the Dear ImGui frame
-    ImGuiIO& io = ImGui::GetIO();
         ImGui_ImplSDLRenderer_NewFrame();
         ImGui_ImplSDL2_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -174,6 +144,16 @@ bool MainLoopStep()
         SDL_RenderClear(renderer);
         ImGui_ImplSDLRenderer_RenderDrawData(ImGui::GetDrawData());
         SDL_RenderPresent(renderer);
+    }
+
+    // Cleanup
+    ImGui_ImplSDLRenderer_Shutdown();
+    ImGui_ImplSDL2_Shutdown();
+    ImGui::DestroyContext();
+
+    SDL_DestroyRenderer(renderer);
+    SDL_DestroyWindow(window);
+    SDL_Quit();
 
-    return true;
+    return 0;
 }

examples/example_sdl_vulkan/main.cpp

@@ -34,14 +34,10 @@ static VkDebugReportCallbackEXT g_DebugReport = VK_NULL_HANDLE;
 static VkPipelineCache          g_PipelineCache = VK_NULL_HANDLE;
 static VkDescriptorPool         g_DescriptorPool = VK_NULL_HANDLE;
 
-static SDL_Window*              g_AppWindow = NULL;
 static ImGui_ImplVulkanH_Window g_MainWindowData;
 static uint32_t                 g_MinImageCount = 2;
 static bool                     g_SwapChainRebuild = false;
 
-// Forward declarations of helper functions
-bool MainLoopStep();
-
 static void check_vk_result(VkResult err)
 {
     if (err == 0)
@@ -363,7 +359,6 @@ int main(int, char**)
     SDL_Vulkan_GetInstanceExtensions(window, &extensions_count, extensions);
     SetupVulkan(extensions, extensions_count);
     delete[] extensions;
-    g_AppWindow = window;
 
     // Create Window Surface
     VkSurfaceKHR surface;
@@ -455,45 +450,28 @@ int main(int, char**)
         ImGui_ImplVulkan_DestroyFontUploadObjects();
     }
 
-    // Main loop
-    while (true)
-    {
-        if (!MainLoopStep())
-            break;
-    }
-
-    // Cleanup
-    err = vkDeviceWaitIdle(g_Device);
-    check_vk_result(err);
-    ImGui_ImplVulkan_Shutdown();
-    ImGui_ImplSDL2_Shutdown();
-    ImGui::DestroyContext();
-
-    CleanupVulkanWindow();
-    CleanupVulkan();
-
-    SDL_DestroyWindow(window);
-    SDL_Quit();
-
-    return 0;
-}
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
-bool MainLoopStep()
+    // Main loop
+    bool done = false;
+    while (!done)
     {
         // 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, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-    SDL_Window* window = g_AppWindow;
         SDL_Event event;
         while (SDL_PollEvent(&event))
         {
             ImGui_ImplSDL2_ProcessEvent(&event);
             if (event.type == SDL_QUIT)
-            return false;
+                done = true;
             if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
-            return false;
+                done = true;
         }
 
         // Resize swap chain?
@@ -515,12 +493,6 @@ bool MainLoopStep()
         ImGui_ImplSDL2_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -564,7 +536,6 @@ bool MainLoopStep()
         const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);
         if (!is_minimized)
         {
-        ImGui_ImplVulkanH_Window* wd = &g_MainWindowData;
             wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
             wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
             wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
@@ -572,6 +543,20 @@ bool MainLoopStep()
             FrameRender(wd, draw_data);
             FramePresent(wd);
         }
+    }
+
+    // Cleanup
+    err = vkDeviceWaitIdle(g_Device);
+    check_vk_result(err);
+    ImGui_ImplVulkan_Shutdown();
+    ImGui_ImplSDL2_Shutdown();
+    ImGui::DestroyContext();
+
+    CleanupVulkanWindow();
+    CleanupVulkan();
 
-    return true;
+    SDL_DestroyWindow(window);
+    SDL_Quit();
+
+    return 0;
 }

examples/example_win32_directx10/main.cpp

@@ -15,7 +15,6 @@ static IDXGISwapChain*          g_pSwapChain = NULL;
 static ID3D10RenderTargetView*  g_mainRenderTargetView = NULL;
 
 // Forward declarations of helper functions
-bool MainLoopStep();
 bool CreateDeviceD3D(HWND hWnd);
 void CleanupDeviceD3D();
 void CreateRenderTarget();
@@ -74,30 +73,17 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
-    // Main loop
-    while (true)
-    {
-        if (!MainLoopStep())
-            break;
-    }
-
-    // Cleanup
-    ImGui_ImplDX10_Shutdown();
-    ImGui_ImplWin32_Shutdown();
-    ImGui::DestroyContext();
-
-    CleanupDeviceD3D();
-    ::DestroyWindow(hwnd);
-    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
-
-    return 0;
-}
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
-bool MainLoopStep()
+    // Main loop
+    bool done = false;
+    while (!done)
     {
         // Poll and handle messages (inputs, window resize, etc.)
-    // See the WndProc() function below where we dispatch events to the imgui_impl_win32 backend.
-    bool done = false;
+        // See the WndProc() function below for our to dispatch events to the Win32 backend.
         MSG msg;
         while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
         {
@@ -107,19 +93,13 @@ bool MainLoopStep()
                 done = true;
         }
         if (done)
-        return false;
+            break;
 
         // Start the Dear ImGui frame
         ImGui_ImplDX10_NewFrame();
         ImGui_ImplWin32_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -166,8 +146,17 @@ bool MainLoopStep()
 
         g_pSwapChain->Present(1, 0); // Present with vsync
         //g_pSwapChain->Present(0, 0); // Present without vsync
+    }
 
-    return true;
+    ImGui_ImplDX10_Shutdown();
+    ImGui_ImplWin32_Shutdown();
+    ImGui::DestroyContext();
+
+    CleanupDeviceD3D();
+    ::DestroyWindow(hwnd);
+    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
+
+    return 0;
 }
 
 // Helper functions

examples/example_win32_directx11/main.cpp

@@ -15,7 +15,6 @@ static IDXGISwapChain*          g_pSwapChain = NULL;
 static ID3D11RenderTargetView*  g_mainRenderTargetView = NULL;
 
 // Forward declarations of helper functions
-bool MainLoopStep();
 bool CreateDeviceD3D(HWND hWnd);
 void CleanupDeviceD3D();
 void CreateRenderTarget();
@@ -74,30 +73,17 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
-    // Main loop
-    while (true)
-    {
-        if (!MainLoopStep())
-            break;
-    }
-
-    // Cleanup
-    ImGui_ImplDX11_Shutdown();
-    ImGui_ImplWin32_Shutdown();
-    ImGui::DestroyContext();
-
-    CleanupDeviceD3D();
-    ::DestroyWindow(hwnd);
-    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
-
-    return 0;
-}
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
-bool MainLoopStep()
+    // Main loop
+    bool done = false;
+    while (!done)
     {
         // Poll and handle messages (inputs, window resize, etc.)
-    // See the WndProc() function below where we dispatch events to the imgui_impl_win32 backend.
-    bool done = false;
+        // See the WndProc() function below for our to dispatch events to the Win32 backend.
         MSG msg;
         while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
         {
@@ -107,19 +93,13 @@ bool MainLoopStep()
                 done = true;
         }
         if (done)
-        return false;
+            break;
 
         // Start the Dear ImGui frame
         ImGui_ImplDX11_NewFrame();
         ImGui_ImplWin32_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -166,7 +146,18 @@ bool MainLoopStep()
 
         g_pSwapChain->Present(1, 0); // Present with vsync
         //g_pSwapChain->Present(0, 0); // Present without vsync
-    return true;
+    }
+
+    // Cleanup
+    ImGui_ImplDX11_Shutdown();
+    ImGui_ImplWin32_Shutdown();
+    ImGui::DestroyContext();
+
+    CleanupDeviceD3D();
+    ::DestroyWindow(hwnd);
+    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
+
+    return 0;
 }
 
 // Helper functions

examples/example_win32_directx12/main.cpp

@@ -48,7 +48,6 @@ static ID3D12Resource*              g_mainRenderTargetResource[NUM_BACK_BUFFERS]
 static D3D12_CPU_DESCRIPTOR_HANDLE  g_mainRenderTargetDescriptor[NUM_BACK_BUFFERS] = {};
 
 // Forward declarations of helper functions
-bool MainLoopStep();
 bool CreateDeviceD3D(HWND hWnd);
 void CleanupDeviceD3D();
 void CreateRenderTarget();
@@ -112,31 +111,17 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
-    // Main loop
-    while (true)
-    {
-        if (!MainLoopStep())
-            break;
-    }
-
-    // Cleanup
-    WaitForLastSubmittedFrame();
-    ImGui_ImplDX12_Shutdown();
-    ImGui_ImplWin32_Shutdown();
-    ImGui::DestroyContext();
-
-    CleanupDeviceD3D();
-    ::DestroyWindow(hwnd);
-    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
-
-    return 0;
-}
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
-bool MainLoopStep()
+    // Main loop
+    bool done = false;
+    while (!done)
     {
         // Poll and handle messages (inputs, window resize, etc.)
-    // See the WndProc() function below where we dispatch events to the imgui_impl_win32 backend.
-    bool done = false;
+        // See the WndProc() function below for our to dispatch events to the Win32 backend.
         MSG msg;
         while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
         {
@@ -146,19 +131,13 @@ bool MainLoopStep()
                 done = true;
         }
         if (done)
-        return false;
+            break;
 
         // Start the Dear ImGui frame
         ImGui_ImplDX12_NewFrame();
         ImGui_ImplWin32_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -233,8 +212,20 @@ bool MainLoopStep()
         g_pd3dCommandQueue->Signal(g_fence, fenceValue);
         g_fenceLastSignaledValue = fenceValue;
         frameCtx->FenceValue = fenceValue;
+    }
 
-    return true;
+    WaitForLastSubmittedFrame();
+
+    // Cleanup
+    ImGui_ImplDX12_Shutdown();
+    ImGui_ImplWin32_Shutdown();
+    ImGui::DestroyContext();
+
+    CleanupDeviceD3D();
+    ::DestroyWindow(hwnd);
+    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
+
+    return 0;
 }
 
 // Helper functions

examples/example_win32_directx9/main.cpp

@@ -14,7 +14,6 @@ static LPDIRECT3DDEVICE9        g_pd3dDevice = NULL;
 static D3DPRESENT_PARAMETERS    g_d3dpp = {};
 
 // Forward declarations of helper functions
-bool MainLoopStep();
 bool CreateDeviceD3D(HWND hWnd);
 void CleanupDeviceD3D();
 void ResetDevice();
@@ -72,30 +71,17 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
-    // Main loop
-    while (true)
-    {
-        if (!MainLoopStep())
-            break;
-    }
-
-    // Cleanup
-    ImGui_ImplDX9_Shutdown();
-    ImGui_ImplWin32_Shutdown();
-    ImGui::DestroyContext();
-
-    CleanupDeviceD3D();
-    ::DestroyWindow(hwnd);
-    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
-
-    return 0;
-}
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
-bool MainLoopStep()
+    // Main loop
+    bool done = false;
+    while (!done)
     {
         // Poll and handle messages (inputs, window resize, etc.)
-    // See the WndProc() function below where we dispatch events to the imgui_impl_win32 backend.
-    bool done = false;
+        // See the WndProc() function below for our to dispatch events to the Win32 backend.
         MSG msg;
         while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
         {
@@ -105,19 +91,13 @@ bool MainLoopStep()
                 done = true;
         }
         if (done)
-        return false;
+            break;
 
         // Start the Dear ImGui frame
         ImGui_ImplDX9_NewFrame();
         ImGui_ImplWin32_NewFrame();
         ImGui::NewFrame();
 
-    // Our state
-    // (we use static, which essentially makes the variable globals, as a convenience to keep the example code easy to follow)
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
         // 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);
@@ -173,8 +153,17 @@ bool MainLoopStep()
         // Handle loss of D3D9 device
         if (result == D3DERR_DEVICELOST && g_pd3dDevice->TestCooperativeLevel() == D3DERR_DEVICENOTRESET)
             ResetDevice();
+    }
 
-    return true;
+    ImGui_ImplDX9_Shutdown();
+    ImGui_ImplWin32_Shutdown();
+    ImGui::DestroyContext();
+
+    CleanupDeviceD3D();
+    ::DestroyWindow(hwnd);
+    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
+
+    return 0;
 }
 
 // Helper functions