Merge branch 'master' into docking

# Conflicts:
#	backends/imgui_impl_glfw.cpp
#	backends/imgui_impl_sdl.cpp
#	examples/example_emscripten_opengl3/main.cpp
#	examples/example_glfw_opengl2/main.cpp
#	examples/example_glfw_opengl3/main.cpp
#	examples/example_glfw_vulkan/main.cpp
#	examples/example_glut_opengl2/main.cpp
#	examples/example_sdl_directx11/main.cpp
#	examples/example_sdl_opengl2/main.cpp
#	examples/example_sdl_opengl3/main.cpp
#	examples/example_sdl_vulkan/main.cpp
#	examples/example_win32_directx10/main.cpp
#	examples/example_win32_directx11/main.cpp
#	examples/example_win32_directx12/main.cpp
#	examples/example_win32_directx9/main.cpp
#	imgui_demo.cpp

.gitignore

@@ -40,7 +40,8 @@ xcuserdata
 examples/*.o.tmp
 examples/*.out.js
 examples/*.out.wasm
-examples/example_emscripten_opengl3/web/*
+examples/example_glfw_opengl3/web/*
+examples/example_sdl_opengl3/web/*
 examples/example_emscripten_wgpu/web/*
 
 ## JetBrains IDE artifacts

backends/imgui_impl_glfw.cpp

@@ -21,7 +21,6 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
-//  2023-02-01: Inputs: flipping both wheel axises when running on Emscripten's GLFW emulation. (#6096)
 //  2023-01-18: Handle unsupported glfwGetVideoMode() call on e.g. Emscripten.
 //  2023-01-04: Inputs: Fixed mods state on Linux when using Alt-GR text input (e.g. German keyboard layout), could lead to broken text input. Revert a 2022/01/17 change were we resumed using mods provided by GLFW, turns out they were faulty.
 //  2022-11-22: Perform a dummy glfwGetError() read to cancel missing names with glfwGetKeyName(). (#5908)
@@ -319,13 +318,6 @@ void ImGui_ImplGlfw_ScrollCallback(GLFWwindow* window, double xoffset, double yo
     if (bd->PrevUserCallbackScroll != nullptr && window == bd->Window)
         bd->PrevUserCallbackScroll(window, xoffset, yoffset);
 
-#if defined(__EMSCRIPTEN__)
-    // Emscripten's GLFW emulation reports grossly mis-scaled and flipped scroll events.
-    // The scale is still currently incorrect, see #4019 #6096 for details.
-    xoffset /= -120.0f;
-    yoffset /= -120.0f;
-#endif
-
     ImGuiIO& io = ImGui::GetIO();
     io.AddMouseWheelEvent((float)xoffset, (float)yoffset);
 }

backends/imgui_impl_opengl3.cpp

@@ -109,12 +109,13 @@
 // Clang warnings with -Weverything
 #if defined(__clang__)
 #pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wold-style-cast"     // warning: use of old-style cast
-#pragma clang diagnostic ignored "-Wsign-conversion"    // warning: implicit conversion changes signedness
+#pragma clang diagnostic ignored "-Wold-style-cast"         // warning: use of old-style cast
+#pragma clang diagnostic ignored "-Wsign-conversion"        // warning: implicit conversion changes signedness
 #endif
 #if defined(__GNUC__)
 #pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wcast-function-type"   // warning: cast between incompatible function types
+#pragma GCC diagnostic ignored "-Wunknown-warning-option"   // warning: unknown warning group 'xxx'
+#pragma GCC diagnostic ignored "-Wcast-function-type"       // warning: cast between incompatible function types
 #endif
 
 // GL includes

backends/imgui_impl_sdl.cpp

@@ -21,6 +21,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2023-02-02: Removed SDL_MOUSEWHEEL value clamping, as values seem correct in latest Emscripten. (#4019)
 //  2023-02-01: Flipping SDL_MOUSEWHEEL 'wheel.x' value to match other backends and offer consistent horizontal scrolling direction. (#4019, #6096, #1463)
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  2022-09-26: Inputs: Disable SDL 2.0.22 new "auto capture" (SDL_HINT_MOUSE_AUTO_CAPTURE) which prevents drag and drop across windows for multi-viewport support + don't capture when drag and dropping. (#5710)
@@ -288,8 +289,8 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
         }
         case SDL_MOUSEWHEEL:
         {
-            float wheel_x = (event->wheel.x < 0) ? 1.0f : (event->wheel.x > 0) ? -1.0f : 0.0f; // About the clamping and flipped axis: see #4019
-            float wheel_y = (event->wheel.y > 0) ? 1.0f : (event->wheel.y < 0) ? -1.0f : 0.0f;
+            float wheel_x = -(float)event->wheel.x;
+            float wheel_y = (float)event->wheel.y;
             io.AddMouseWheelEvent(wheel_x, wheel_y);
             return true;
         }

docs/CHANGELOG.txt

@@ -112,8 +112,6 @@ Breaking changes:
     offer consistent horizontal scrolling direction. (#4019)
   - Backends: SDL: flipping SDL_MOUSEWHEEL 'wheel.x' value to match other backends and
     offer consistent horizontal scrolling direction. (#4019)
-  - Backends: GLFW+Emscripten: flipping both wheels axises + scaling magnitude down when
-    running on Emscripten's GLFW emulation. (#6096) [@topolarity]
   - Shift+WheelY support on non-OSX machines was already correct. (#2424, #1463)
     (whereaas on OSX machines Shift+WheelY turns into WheelX at the OS level).
   - If you use a custom-backend, you should verify that:
@@ -125,7 +123,7 @@ Breaking changes:
     - (*) both axises flipped On Windows for touchpad only when 'Settings->Touchpad->Down motion scrolls up' is set.
     - You can use 'Demo->Tools->Debug Log->IO" to visualize values submitted to Dear ImGui.
   - Known issues remaining with Emscripten:
-    - The magnitude of wheeling values on Emscripten setups is still mostly wrong. (#6096)
+    - The magnitude of wheeling values on Emscripten setups is still not great. (#6096)
     - When running the Emscripten app on a Mac with a mouse, SHIFT+WheelY doesn't turn into WheelX.
       This is because we don't know that we are running on Mac and apply our own Shift+swapping
       on top of OSX' own swapping, so wheel axises are swapped twice. Emscripten apps may need
@@ -158,8 +156,14 @@ All changes:
   can exacerbate that. (#6114, #3644)
 - Backends: OSX: Fixed scroll/wheel scaling for devices emitting events with
   hasPreciseScrollingDeltas==false (e.g. non-Apple mices).
+- Backends: SDL: Removed SDL_MOUSEWHEEL value clamping. (#4019, #6096, #6081)
+  Latest Emscripten seems to emit correct values.
 - Backend: 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: Win32: Fixed examples using RegisterClassW() since 1.89 to also call
   DefWindowProcW() instead of DefWindowProc() so that title text are correctly converted
   when application is compiled without /DUNICODE. (#5725, #5961, #5975) [@markreidvfx]

docs/EXAMPLES.md

@@ -104,15 +104,10 @@ OSX + OpenGL2 example. <BR>
 (NB: imgui_impl_osx.mm is currently not as feature complete as other platforms backends.
  You may prefer to use the GLFW Or SDL backends, which will also support Windows and Linux.)
 
-[example_emscripten_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_emscripten_opengl3/) <BR>
-Emcripten + SDL2 + OpenGL3+/ES2/ES3 example. <BR>
-= main.cpp + imgui_impl_sdl.cpp + imgui_impl_opengl3.cpp <BR>
-Note that other examples based on SDL or GLFW + OpenGL could easily be modified to work with Emscripten.
-We provide this to make the Emscripten differences obvious, and have them not pollute all other examples.
-
 [example_emscripten_wgpu/](https://github.com/ocornut/imgui/blob/master/examples/example_emscripten_wgpu/) <BR>
 Emcripten + GLFW + WebGPU example. <BR>
 = main.cpp + imgui_impl_glfw.cpp + imgui_impl_wgpu.cpp
+Note that the 'example_glfw_opengl3' and 'example_sdl_opengl3' examples also supports Emscripten!
 
 [example_glfw_metal/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_metal/) <BR>
 GLFW (Mac) + Metal example. <BR>
@@ -121,18 +116,18 @@ GLFW (Mac) + Metal example. <BR>
 [example_glfw_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_opengl2/) <BR>
 GLFW + OpenGL2 example (legacy, fixed pipeline). <BR>
 = main.cpp + imgui_impl_glfw.cpp + imgui_impl_opengl2.cpp <BR>
-**DO NOT USE THIS IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)** <BR>
+**DO NOT USE THIS IF YOUR CODE/ENGINE IS USING MODERN GL or WEBGL (SHADERS, VBO, VAO, etc.)** <BR>
 This code is mostly provided as a reference to learn about Dear ImGui integration, because it is shorter.
-If your code is using GL3+ context or any semi modern OpenGL calls, using this renderer is likely to
-make things more complicated, will require your code to reset many OpenGL attributes to their initial
+If your code is using GL3+ context or any semi modern GL calls, using this renderer is likely to
+make things more complicated, will require your code to reset many GL attributes to their initial
 state, and might confuse your GPU driver. One star, not recommended.
 
 [example_glfw_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_opengl3/) <BR>
 GLFW (Win32, Mac, Linux) + OpenGL3+/ES2/ES3 example (modern, programmable pipeline). <BR>
 = main.cpp + imgui_impl_glfw.cpp + imgui_impl_opengl3.cpp <BR>
-This uses more modern OpenGL calls and custom shaders. <BR>
-This may actually also work with OpenGL 2.x contexts! <BR>
-Prefer using that if you are using modern OpenGL in your application (anything with shaders).
+This uses more modern GL calls and custom shaders.<BR>
+This support building with Emscripten and targetting WebGL.<BR>
+Prefer using that if you are using modern GL or WebGL in your application.
 
 [example_glfw_vulkan/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_vulkan/) <BR>
 GLFW (Win32, Mac, Linux) + Vulkan example. <BR>
@@ -163,17 +158,18 @@ SDL2 (Mac) + Metal example. <BR>
 [example_sdl_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl_opengl2/) <BR>
 SDL2 (Win32, Mac, Linux etc.) + OpenGL example (legacy, fixed pipeline). <BR>
 = main.cpp + imgui_impl_sdl.cpp + imgui_impl_opengl2.cpp <BR>
-**DO NOT USE OPENGL2 CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)** <BR>
+**DO NOT USE OPENGL2 CODE IF YOUR CODE/ENGINE IS USING GL OR WEBGL (SHADERS, VBO, VAO, etc.)** <BR>
 This code is mostly provided as a reference to learn about Dear ImGui integration, because it is shorter.
-If your code is using GL3+ context or any semi modern OpenGL calls, using this renderer is likely to
-make things more complicated, will require your code to reset many OpenGL attributes to their initial
+If your code is using GL3+ context or any semi modern GL calls, using this renderer is likely to
+make things more complicated, will require your code to reset many GL attributes to their initial
 state, and might confuse your GPU driver. One star, not recommended.
 
 [example_sdl_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl_opengl3/) <BR>
 SDL2 (Win32, Mac, Linux, etc.) + OpenGL3+/ES2/ES3 example. <BR>
 = main.cpp + imgui_impl_sdl.cpp + imgui_impl_opengl3.cpp <BR>
-This uses more modern OpenGL calls and custom shaders. <BR>
-This may actually also work with OpenGL 2.x contexts! <BR>
+This uses more modern GL calls and custom shaders. <BR>
+This support building with Emscripten and targetting WebGL.<BR>
+Prefer using that if you are using modern GL or WebGL in your application.
 
 [example_sdl_sdlrenderer/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl_sdlrenderer/) <BR>
 SDL2 (Win32, Mac, Linux, etc.) + SDL_Renderer (most graphics backends are supported underneath) <BR>

examples/example_allegro5/main.cpp

@@ -16,6 +16,10 @@
 #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
@@ -23,6 +27,8 @@ 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");
@@ -61,86 +67,98 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
-    bool show_demo_window = true;
-    bool show_another_window = false;
-    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
     // Main loop
-    bool running = true;
-    while (running)
+    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 MainLoopStep(ALLEGRO_DISPLAY* display, ALLEGRO_EVENT_QUEUE* queue)
+{
+    // 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))
     {
-        // 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.
-        ALLEGRO_EVENT ev;
-        while (al_get_next_event(queue, &ev))
+        ImGui_ImplAllegro5_ProcessEvent(&ev);
+        if (ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
+            done = true;
+        if (ev.type == ALLEGRO_EVENT_DISPLAY_RESIZE)
         {
-            ImGui_ImplAllegro5_ProcessEvent(&ev);
-            if (ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
-                running = false;
-            if (ev.type == ALLEGRO_EVENT_DISPLAY_RESIZE)
-            {
-                ImGui_ImplAllegro5_InvalidateDeviceObjects();
-                al_acknowledge_resize(display);
-                ImGui_ImplAllegro5_CreateDeviceObjects();
-            }
+            ImGui_ImplAllegro5_InvalidateDeviceObjects();
+            al_acknowledge_resize(display);
+            ImGui_ImplAllegro5_CreateDeviceObjects();
         }
+    }
+    if (done)
+        return false;
 
-        // Start the Dear ImGui frame
-        ImGui_ImplAllegro5_NewFrame();
-        ImGui::NewFrame();
+    // Start the Dear ImGui frame
+    ImGui_ImplAllegro5_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);
+    // 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);
 
-        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
-        {
-            static float f = 0.0f;
-            static int counter = 0;
+    // 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);
 
-            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    {
+        static float f = 0.0f;
+        static int counter = 0;
 
-            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::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
 
-            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
+        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);
 
-            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::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
 
-            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
-            ImGui::End();
-        }
+        if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+            counter++;
+        ImGui::SameLine();
+        ImGui::Text("counter = %d", counter);
 
-        // 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();
-        }
+        ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
+        ImGui::End();
+    }
 
-        // Rendering
-        ImGui::Render();
-        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();
+    // 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();
     }
 
-    // Cleanup
-    ImGui_ImplAllegro5_Shutdown();
-    ImGui::DestroyContext();
-    al_destroy_event_queue(queue);
-    al_destroy_display(display);
+    // Rendering
+    ImGui::Render();
+    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();
 
-    return 0;
+    return true;
 }

examples/example_android_opengl3/main.cpp

@@ -21,11 +21,72 @@ static char                 g_LogTag[] = "ImGuiExample";
 static std::string          g_IniFilename = "";
 
 // Forward declarations of helper functions
+static void Init(struct android_app* app);
+static void Shutdown();
+static void MainLoopStep();
 static int ShowSoftKeyboardInput();
 static int PollUnicodeChars();
 static int GetAssetData(const char* filename, void** out_data);
 
-void init(struct android_app* app)
+// Main code
+static void handleAppCmd(struct android_app* app, int32_t appCmd)
+{
+    switch (appCmd)
+    {
+    case APP_CMD_SAVE_STATE:
+        break;
+    case APP_CMD_INIT_WINDOW:
+        Init(app);
+        break;
+    case APP_CMD_TERM_WINDOW:
+        Shutdown();
+        break;
+    case APP_CMD_GAINED_FOCUS:
+    case APP_CMD_LOST_FOCUS:
+        break;
+    }
+}
+
+static int32_t handleInputEvent(struct android_app* app, AInputEvent* inputEvent)
+{
+    return ImGui_ImplAndroid_HandleInputEvent(inputEvent);
+}
+
+void android_main(struct android_app* app)
+{
+    app->onAppCmd = handleAppCmd;
+    app->onInputEvent = handleInputEvent;
+
+    while (true)
+    {
+        int out_events;
+        struct android_poll_source* out_data;
+
+        // Poll all events. If the app is not visible, this loop blocks until g_Initialized == true.
+        while (ALooper_pollAll(g_Initialized ? 0 : -1, NULL, &out_events, (void**)&out_data) >= 0)
+        {
+            // Process one event
+            if (out_data != NULL)
+                out_data->process(app, out_data);
+
+            // Exit the app by returning from within the infinite loop
+            if (app->destroyRequested != 0)
+            {
+                // shutdown() should have been called already while processing the
+                // app command APP_CMD_TERM_WINDOW. But we play save here
+                if (!g_Initialized)
+                    Shutdown();
+
+                return;
+            }
+        }
+
+        // Initiate a new frame
+        MainLoopStep();
+    }
+}
+
+void Init(struct android_app* app)
 {
     if (g_Initialized)
         return;
@@ -125,13 +186,14 @@ void init(struct android_app* app)
     g_Initialized = true;
 }
 
-void tick()
+void MainLoopStep()
 {
     ImGuiIO& io = ImGui::GetIO();
     if (g_EglDisplay == EGL_NO_DISPLAY)
         return;
 
     // 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);
@@ -197,7 +259,7 @@ void tick()
     eglSwapBuffers(g_EglDisplay, g_EglSurface);
 }
 
-void shutdown()
+void Shutdown()
 {
     if (!g_Initialized)
         return;
@@ -228,63 +290,7 @@ void shutdown()
     g_Initialized = false;
 }
 
-static void handleAppCmd(struct android_app* app, int32_t appCmd)
-{
-    switch (appCmd)
-    {
-    case APP_CMD_SAVE_STATE:
-        break;
-    case APP_CMD_INIT_WINDOW:
-        init(app);
-        break;
-    case APP_CMD_TERM_WINDOW:
-        shutdown();
-        break;
-    case APP_CMD_GAINED_FOCUS:
-        break;
-    case APP_CMD_LOST_FOCUS:
-        break;
-    }
-}
-
-static int32_t handleInputEvent(struct android_app* app, AInputEvent* inputEvent)
-{
-    return ImGui_ImplAndroid_HandleInputEvent(inputEvent);
-}
-
-void android_main(struct android_app* app)
-{
-    app->onAppCmd = handleAppCmd;
-    app->onInputEvent = handleInputEvent;
-
-    while (true)
-    {
-        int out_events;
-        struct android_poll_source* out_data;
-
-        // Poll all events. If the app is not visible, this loop blocks until g_Initialized == true.
-        while (ALooper_pollAll(g_Initialized ? 0 : -1, NULL, &out_events, (void**)&out_data) >= 0)
-        {
-            // Process one event
-            if (out_data != NULL)
-                out_data->process(app, out_data);
-
-            // Exit the app by returning from within the infinite loop
-            if (app->destroyRequested != 0)
-            {
-                // shutdown() should have been called already while processing the
-                // app command APP_CMD_TERM_WINDOW. But we play save here
-                if (!g_Initialized)
-                    shutdown();
-
-                return;
-            }
-        }
-
-        // Initiate a new frame
-        tick();
-    }
-}
+// Helper functions
 
 // Unfortunately, there is no way to show the on-screen input from native code.
 // Therefore, we call ShowSoftKeyboardInput() of the main activity implemented in MainActivity.kt via JNI.

examples/example_emscripten_glfw_opengl3/main.cpp

@@ -1,167 +0,0 @@
-// Dear ImGui: standalone example application for Emscripten, using GLFW + OpenGL3
-// (Emscripten is a C++-to-javascript compiler, used to publish executables for the web. See https://emscripten.org/)
-// 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 is mostly the same code as the GLFW + OpenGL3 example, simply with the modifications needed to run on Emscripten.
-// It is possible to combine both code into a single source file that will compile properly on Desktop and using Emscripten.
-// See https://github.com/ocornut/imgui/pull/2492 as an example on how to do just that.
-
-#include "imgui.h"
-#include "imgui_impl_glfw.h"
-#include "imgui_impl_opengl3.h"
-#include <stdio.h>
-#include <emscripten.h>
-#define GL_SILENCE_DEPRECATION
-#if defined(IMGUI_IMPL_OPENGL_ES2)
-#include <GLES2/gl2.h>
-#endif
-#include <GLFW/glfw3.h> // Will drag system OpenGL headers
-
-// Emscripten requires to have full control over the main loop. We're going to store our GLFW book-keeping variables globally.
-// Having a single function that acts as a loop prevents us to store state in the stack of said function. So we need some location for this.
-GLFWwindow*     g_Window = NULL;
-
-static void glfw_error_callback(int error, const char* description)
-{
-    fprintf(stderr, "Glfw Error %d: %s\n", error, description);
-}
-
-// For clarity, our main loop code is declared at the end.
-static void main_loop(void*);
-
-int main(int, char**)
-{
-    // Setup window
-    glfwSetErrorCallback(glfw_error_callback);
-    if (!glfwInit())
-        return 1;
-
-    // For the browser using Emscripten, we are going to use WebGL1 with GL ES2. See the Makefile. for requirement details.
-    // It is very likely the generated file won't work in many browsers. Firefox is the only sure bet, but I have successfully
-    // run this code on Chrome for Android for example.
-    const char* glsl_version = "#version 100";
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
-    glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
-
-    // Create window with graphics context
-    GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+Emscripten example", NULL, NULL);
-    if (window == NULL)
-        return 1;
-    glfwMakeContextCurrent(window);
-    glfwSwapInterval(1); // Enable vsync
-    g_Window = window;
-
-    // Setup Dear ImGui context
-    IMGUI_CHECKVERSION();
-    ImGui::CreateContext();
-    ImGuiIO& io = ImGui::GetIO(); (void)io;
-    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
-    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
-
-    // 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;
-
-    // Setup Dear ImGui style
-    ImGui::StyleColorsDark();
-    //ImGui::StyleColorsLight();
-
-    // Setup Platform/Renderer backends
-    ImGui_ImplGlfw_InitForOpenGL(window, true);
-    ImGui_ImplOpenGL3_Init(glsl_version);
-
-    // Load Fonts
-    // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
-    // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
-    // - If the file cannot be loaded, the function will return NULL. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
-    // - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
-    // - 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 \\ !
-    // - Emscripten allows preloading a file or folder to be accessible at runtime. See Makefile for details.
-    //io.Fonts->AddFontDefault();
-#ifndef IMGUI_DISABLE_FILE_FUNCTIONS
-    //io.Fonts->AddFontFromFileTTF("fonts/segoeui.ttf", 18.0f);
-    io.Fonts->AddFontFromFileTTF("fonts/DroidSans.ttf", 16.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/Roboto-Medium.ttf", 16.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/Cousine-Regular.ttf", 15.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/ProggyTiny.ttf", 10.0f);
-    //ImFont* font = io.Fonts->AddFontFromFileTTF("fonts/ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
-    //IM_ASSERT(font != NULL);
-#endif
-
-    // This function call won't return, and will engage in an infinite loop, processing events from the browser, and dispatching them.
-    emscripten_set_main_loop_arg(main_loop, NULL, 0, true);
-}
-
-static void main_loop(void* arg)
-{
-    IM_UNUSED(arg); // We can pass this argument as the second parameter of emscripten_set_main_loop_arg(), but we don't use that.
-
-    // Our state (make them static = more or less global) as a convenience to keep the example terse.
-    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);
-
-    // 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.
-    glfwPollEvents();
-
-    // Start the Dear ImGui frame
-    ImGui_ImplOpenGL3_NewFrame();
-    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 create 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();
-    int display_w, display_h;
-    glfwGetFramebufferSize(g_Window, &display_w, &display_h);
-    glViewport(0, 0, display_w, display_h);
-    glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
-    glClear(GL_COLOR_BUFFER_BIT);
-    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
-
-    glfwSwapBuffers(g_Window);
-}

examples/example_emscripten_glfw_opengl3/shell_minimal.html

@@ -1,64 +0,0 @@
-<!doctype html>
-<html lang="en-us">
-  <head>
-    <meta charset="utf-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no"/>
-    <title>Dear ImGui GLFW+Emscripten example</title>
-    <style>
-        body { margin: 0; background-color: black }
-        .emscripten {
-            position: absolute;
-            top: 0px;
-            left: 0px;
-            margin: 0px;
-            border: 0;
-            width: 100%;
-            height: 100%;
-            overflow: hidden;
-            display: block;
-            image-rendering: optimizeSpeed;
-            image-rendering: -moz-crisp-edges;
-            image-rendering: -o-crisp-edges;
-            image-rendering: -webkit-optimize-contrast;
-            image-rendering: optimize-contrast;
-            image-rendering: crisp-edges;
-            image-rendering: pixelated;
-            -ms-interpolation-mode: nearest-neighbor;
-        }
-    </style>
-  </head>
-  <body>
-    <canvas class="emscripten" id="canvas" oncontextmenu="event.preventDefault()"></canvas>
-    <script type='text/javascript'>
-      var Module = {
-        preRun: [],
-        postRun: [],
-        print: (function() {
-            return function(text) {
-                text = Array.prototype.slice.call(arguments).join(' ');
-                console.log(text);
-            };
-        })(),
-        printErr: function(text) {
-            text = Array.prototype.slice.call(arguments).join(' ');
-            console.error(text);
-        },
-        canvas: (function() {
-            var canvas = document.getElementById('canvas');
-            //canvas.addEventListener("webglcontextlost", function(e) { alert('FIXME: WebGL context lost, please reload the page'); e.preventDefault(); }, false);
-            return canvas;
-        })(),
-        setStatus: function(text) {
-            console.log("status: " + text);
-        },
-        monitorRunDependencies: function(left) {
-            // no run dependencies to log
-        }
-      };
-      window.onerror = function() {
-        console.log("onerror: " + event);
-      };
-    </script>
-    {{{ SCRIPT }}}
-  </body>
-</html>

examples/example_emscripten_opengl3/README.md

@@ -1,26 +0,0 @@
-## How to Build
-
-- You need to install Emscripten from https://emscripten.org/docs/getting_started/downloads.html, and have the environment variables set, as described in https://emscripten.org/docs/getting_started/downloads.html#installation-instructions
-
-- Depending on your configuration, in Windows you may need to run `emsdk/emsdk_env.bat` in your console to access the Emscripten command-line tools.
-
-- You may also refer to our [Continuous Integration setup](https://github.com/ocornut/imgui/tree/master/.github/workflows) for Emscripten setup.
-
-- Then build using `make` while in the `example_emscripten_opengl3/` directory.
-
-## How to Run
-
-To run on a local machine:
-- `make serve` will use Python3 to spawn a local webserver, you can then browse http://localhost:8000 to access your build.
-- Otherwise, generally you will need a local webserver:
-  - Quoting [https://emscripten.org/docs/getting_started](https://emscripten.org/docs/getting_started/Tutorial.html#generating-html):<br>
-_"Unfortunately several browsers (including Chrome, Safari, and Internet Explorer) do not support file:// [XHR](https://emscripten.org/docs/site/glossary.html#term-xhr) requests, and can’t load extra files needed by the HTML (like a .wasm file, or packaged file data as mentioned lower down). For these browsers you’ll need to serve the files using a [local webserver](https://emscripten.org/docs/getting_started/FAQ.html#faq-local-webserver) and then open http://localhost:8000/hello.html."_
-  - Emscripten SDK has a handy `emrun` command: `emrun web/example_emscripten_opengl3.html --browser firefox` which will spawn a temporary local webserver (in Firefox). See https://emscripten.org/docs/compiling/Running-html-files-with-emrun.html for details.
-  - You may use Python 3 builtin webserver: `python -m http.server -d web` (this is what `make serve` uses).
-  - You may use Python 2 builtin webserver: `cd web && python -m SimpleHTTPServer`.
-  - If you are accessing the files over a network, certain browsers, such as Firefox, will restrict Gamepad API access to secure contexts only (e.g. https only).
-
-## Obsolete features:
-
-- Emscripten 2.0 (August 2020) obsoleted the fastcomp backend, only llvm is supported.
-- Emscripten 1.39.0 (October 2019) obsoleted the `BINARYEN_TRAP_MODE=clamp` compilation flag which was required with version older than 1.39.0 to avoid rendering artefacts. See [#2877](https://github.com/ocornut/imgui/issues/2877) for details. If you use an older version, uncomment this line in the Makefile: `#EMS += -s BINARYEN_TRAP_MODE=clamp`

examples/example_emscripten_opengl3/main.cpp

@@ -1,177 +0,0 @@
-// Dear ImGui: standalone example application for Emscripten, using SDL2 + OpenGL3
-// (Emscripten is a C++-to-javascript compiler, used to publish executables for the web. See https://emscripten.org/)
-// 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 is mostly the same code as the SDL2 + OpenGL3 example, simply with the modifications needed to run on Emscripten.
-// It is possible to combine both code into a single source file that will compile properly on Desktop and using Emscripten.
-// See https://github.com/ocornut/imgui/pull/2492 as an example on how to do just that.
-
-#include "imgui.h"
-#include "imgui_impl_sdl.h"
-#include "imgui_impl_opengl3.h"
-#include <stdio.h>
-#include <emscripten.h>
-#include <SDL.h>
-#include <SDL_opengles2.h>
-
-// Emscripten requires to have full control over the main loop. We're going to store our SDL book-keeping variables globally.
-// Having a single function that acts as a loop prevents us to store state in the stack of said function. So we need some location for this.
-SDL_Window*     g_Window = NULL;
-SDL_GLContext   g_GLContext = NULL;
-
-// For clarity, our main loop code is declared at the end.
-static void main_loop(void*);
-
-int main(int, char**)
-{
-    // Setup SDL
-    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
-    {
-        printf("Error: %s\n", SDL_GetError());
-        return -1;
-    }
-
-    // For the browser using Emscripten, we are going to use WebGL1 with GL ES2. See the Makefile. for requirement details.
-    // It is very likely the generated file won't work in many browsers. Firefox is the only sure bet, but I have successfully
-    // run this code on Chrome for Android for example.
-    const char* glsl_version = "#version 100";
-    //const char* glsl_version = "#version 300 es";
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
-
-    // Create window with graphics context
-    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
-    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
-    SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
-    SDL_DisplayMode current;
-    SDL_GetCurrentDisplayMode(0, &current);
-    SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
-    g_Window = SDL_CreateWindow("Dear ImGui SDL+Emscripten example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
-    g_GLContext = SDL_GL_CreateContext(g_Window);
-    if (!g_GLContext)
-    {
-        fprintf(stderr, "Failed to initialize WebGL context!\n");
-        return 1;
-    }
-    SDL_GL_SetSwapInterval(1); // Enable vsync
-
-    // Setup Dear ImGui context
-    IMGUI_CHECKVERSION();
-    ImGui::CreateContext();
-    ImGuiIO& io = ImGui::GetIO(); (void)io;
-    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;       // Enable Keyboard Controls
-    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
-    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;           // Enable Docking
-
-    // 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;
-
-    // Setup Dear ImGui style
-    ImGui::StyleColorsDark();
-    //ImGui::StyleColorsLight();
-
-    // Setup Platform/Renderer backends
-    ImGui_ImplSDL2_InitForOpenGL(g_Window, g_GLContext);
-    ImGui_ImplOpenGL3_Init(glsl_version);
-
-    // Load Fonts
-    // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
-    // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
-    // - If the file cannot be loaded, the function will return NULL. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
-    // - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
-    // - 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 \\ !
-    // - Emscripten allows preloading a file or folder to be accessible at runtime. See Makefile for details.
-    //io.Fonts->AddFontDefault();
-#ifndef IMGUI_DISABLE_FILE_FUNCTIONS
-    //io.Fonts->AddFontFromFileTTF("fonts/segoeui.ttf", 18.0f);
-    io.Fonts->AddFontFromFileTTF("fonts/DroidSans.ttf", 16.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/Roboto-Medium.ttf", 16.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/Cousine-Regular.ttf", 15.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/ProggyTiny.ttf", 10.0f);
-    //ImFont* font = io.Fonts->AddFontFromFileTTF("fonts/ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
-    //IM_ASSERT(font != NULL);
-#endif
-
-    // This function call won't return, and will engage in an infinite loop, processing events from the browser, and dispatching them.
-    emscripten_set_main_loop_arg(main_loop, NULL, 0, true);
-}
-
-static void main_loop(void* arg)
-{
-    ImGuiIO& io = ImGui::GetIO();
-    IM_UNUSED(arg); // We can pass this argument as the second parameter of emscripten_set_main_loop_arg(), but we don't use that.
-
-    // Our state (make them static = more or less global) as a convenience to keep the example terse.
-    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);
-
-    // 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_Event event;
-    while (SDL_PollEvent(&event))
-    {
-        ImGui_ImplSDL2_ProcessEvent(&event);
-        // Capture events here, based on io.WantCaptureMouse and io.WantCaptureKeyboard
-    }
-
-    // Start the Dear ImGui frame
-    ImGui_ImplOpenGL3_NewFrame();
-    ImGui_ImplSDL2_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 create 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();
-    SDL_GL_MakeCurrent(g_Window, g_GLContext);
-    glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
-    glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
-    glClear(GL_COLOR_BUFFER_BIT);
-    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
-    SDL_GL_SwapWindow(g_Window);
-}

examples/example_emscripten_wgpu/main.cpp

@@ -21,17 +21,13 @@ static WGPUSwapChain wgpu_swap_chain = NULL;
 static int           wgpu_swap_chain_width = 0;
 static int           wgpu_swap_chain_height = 0;
 
-// States tracked across render frames
-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);
-
 // Forward declarations
-static bool init_wgpu();
-static void main_loop(void* window);
+static void MainLoopStep(void* window);
+static bool InitWGPU();
 static void print_glfw_error(int error, const char* description);
 static void print_wgpu_error(WGPUErrorType error_type, const char* message, void*);
 
+// Main code
 int main(int, char**)
 {
     glfwSetErrorCallback(print_glfw_error);
@@ -39,9 +35,8 @@ int main(int, char**)
         return 1;
 
     // Make sure GLFW does not initialize any graphics context.
-    // This needs to be done explicitly later
+    // This needs to be done explicitly later.
     glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
-
     GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+WebGPU example", NULL, NULL);
     if (!window)
     {
@@ -50,7 +45,7 @@ int main(int, char**)
     }
 
     // Initialize the WebGPU environment
-    if (!init_wgpu())
+    if (!InitWGPU())
     {
         if (window)
             glfwDestroyWindow(window);
@@ -101,12 +96,12 @@ int main(int, char**)
     // This function will directly return and exit the main function.
     // Make sure that no required objects get cleaned up.
     // This way we can use the browsers 'requestAnimationFrame' to control the rendering.
-    emscripten_set_main_loop_arg(main_loop, window, 0, false);
+    emscripten_set_main_loop_arg(MainLoopStep, window, 0, false);
 
     return 0;
 }
 
-static bool init_wgpu()
+static bool InitWGPU()
 {
     wgpu_device = emscripten_webgpu_get_device();
     if (!wgpu_device)
@@ -130,24 +125,21 @@ static bool init_wgpu()
     return true;
 }
 
-static void main_loop(void* window)
+static void MainLoopStep(void* window)
 {
     glfwPollEvents();
 
     int width, height;
-    glfwGetFramebufferSize((GLFWwindow*) window, &width, &height);
+    glfwGetFramebufferSize((GLFWwindow*)window, &width, &height);
 
     // React to changes in screen size
     if (width != wgpu_swap_chain_width && height != wgpu_swap_chain_height)
     {
         ImGui_ImplWGPU_InvalidateDeviceObjects();
-
         if (wgpu_swap_chain)
             wgpuSwapChainRelease(wgpu_swap_chain);
-
         wgpu_swap_chain_width = width;
         wgpu_swap_chain_height = height;
-
         WGPUSwapChainDescriptor swap_chain_desc = {};
         swap_chain_desc.usage = WGPUTextureUsage_RenderAttachment;
         swap_chain_desc.format = WGPUTextureFormat_RGBA8Unorm;
@@ -155,7 +147,6 @@ static void main_loop(void* window)
         swap_chain_desc.height = height;
         swap_chain_desc.presentMode = WGPUPresentMode_Fifo;
         wgpu_swap_chain = wgpuDeviceCreateSwapChain(wgpu_device, wgpu_surface, &swap_chain_desc);
-
         ImGui_ImplWGPU_CreateDeviceObjects();
     }
 
@@ -164,6 +155,12 @@ static void main_loop(void* window)
     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);
@@ -229,7 +226,7 @@ static void main_loop(void* window)
 
 static void print_glfw_error(int error, const char* description)
 {
-    printf("Glfw Error %d: %s\n", error, description);
+    printf("GLFW Error %d: %s\n", error, description);
 }
 
 static void print_wgpu_error(WGPUErrorType error_type, const char* message, void*)

examples/example_glfw_opengl2/main.cpp

@@ -23,22 +23,30 @@
 #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);
+    fprintf(stderr, "GLFW Error %d: %s\n", error, description);
 }
 
+// Main code
 int main(int, char**)
 {
-    // Setup window
     glfwSetErrorCallback(glfw_error_callback);
     if (!glfwInit())
         return 1;
+
+    // Create window with graphics context
     GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+OpenGL2 example", NULL, NULL);
     if (window == NULL)
         return 1;
     glfwMakeContextCurrent(window);
     glfwSwapInterval(1); // Enable vsync
+    g_AppWindow = window;
 
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
@@ -83,92 +91,9 @@ 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))
-    {
-        // 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.
-        glfwPollEvents();
-
-        // Start the Dear ImGui frame
-        ImGui_ImplOpenGL2_NewFrame();
-        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 create 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();
-        int display_w, display_h;
-        glfwGetFramebufferSize(window, &display_w, &display_h);
-        glViewport(0, 0, display_w, display_h);
-        glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
-        glClear(GL_COLOR_BUFFER_BIT);
-
-        // If you are using this code with non-legacy OpenGL header/contexts (which you should not, prefer using imgui_impl_opengl3.cpp!!),
-        // you may need to backup/reset/restore other state, e.g. for current shader using the commented lines below.
-        //GLint last_program;
-        //glGetIntegerv(GL_CURRENT_PROGRAM, &last_program);
-        //glUseProgram(0);
-        ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
-        //glUseProgram(last_program);
-
-        // Update and Render additional Platform Windows
-        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
-        //  For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
-        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
-        {
-            GLFWwindow* backup_current_context = glfwGetCurrentContext();
-            ImGui::UpdatePlatformWindows();
-            ImGui::RenderPlatformWindowsDefault();
-            glfwMakeContextCurrent(backup_current_context);
-        }
-
-        glfwSwapBuffers(window);
-    }
+        MainLoopStep();
 
     // Cleanup
     ImGui_ImplOpenGL2_Shutdown();
@@ -180,3 +105,92 @@ int main(int, char**)
 
     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
+    ImGui_ImplOpenGL2_NewFrame();
+    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);
+
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create 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();
+    int display_w, display_h;
+    glfwGetFramebufferSize(window, &display_w, &display_h);
+    glViewport(0, 0, display_w, display_h);
+    glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
+    glClear(GL_COLOR_BUFFER_BIT);
+
+    // If you are using this code with non-legacy OpenGL header/contexts (which you should not, prefer using imgui_impl_opengl3.cpp!!),
+    // you may need to backup/reset/restore other state, e.g. for current shader using the commented lines below.
+    //GLint last_program;
+    //glGetIntegerv(GL_CURRENT_PROGRAM, &last_program);
+    //glUseProgram(0);
+    ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
+    //glUseProgram(last_program);
+
+    // Update and Render additional Platform Windows
+    // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+    //  For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        GLFWwindow* backup_current_context = glfwGetCurrentContext();
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+        glfwMakeContextCurrent(backup_current_context);
+    }
+
+    glfwMakeContextCurrent(window);
+    glfwSwapBuffers(window);
+}

examples/example_emscripten_glfw_opengl3/Makefile → examples/example_glfw_opengl3/Makefile.emscripten

@@ -6,7 +6,7 @@
 # This Makefile assumes you have loaded emscripten's environment.
 # (On Windows, you may need to execute emsdk_env.bat or encmdprompt.bat ahead)
 #
-# Running `make` will produce three files:
+# Running `make -f Makefile.emscripten` will produce three files:
 #  - web/index.html
 #  - web/index.js
 #  - web/index.wasm
@@ -32,9 +32,8 @@ EMS =
 ##---------------------------------------------------------------------
 
 # ("EMS" options gets added to both CPPFLAGS and LDFLAGS, whereas some options are for linker only)
-EMS += -s USE_GLFW=3
 EMS += -s DISABLE_EXCEPTION_CATCHING=1
-LDFLAGS += -s WASM=1 -s ALLOW_MEMORY_GROWTH=1 -s NO_EXIT_RUNTIME=0 -s ASSERTIONS=1
+LDFLAGS += -s USE_GLFW=3 -s WASM=1 -s ALLOW_MEMORY_GROWTH=1 -s NO_EXIT_RUNTIME=0 -s ASSERTIONS=1
 
 # Uncomment next line to fix possible rendering bugs with Emscripten version older then 1.39.0 (https://github.com/ocornut/imgui/issues/2877)
 #EMS += -s BINARYEN_TRAP_MODE=clamp
@@ -60,7 +59,8 @@ endif
 CPPFLAGS += -I$(IMGUI_DIR) -I$(IMGUI_DIR)/backends
 #CPPFLAGS += -g
 CPPFLAGS += -Wall -Wformat -Os $(EMS)
-LDFLAGS += --shell-file shell_minimal.html $(EMS)
+# LDFLAGS += --shell-file ../libs/emscripten/shell_minimal.html
+LDFLAGS += $(EMS)
 
 ##---------------------------------------------------------------------
 ## BUILD RULES

examples/example_glfw_opengl3/main.cpp

@@ -3,6 +3,8 @@
 // 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"
@@ -20,14 +22,24 @@
 #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);
+    fprintf(stderr, "GLFW Error %d: %s\n", error, description);
 }
 
+// Main code
 int main(int, char**)
 {
-    // Setup window
     glfwSetErrorCallback(glfw_error_callback);
     if (!glfwInit())
         return 1;
@@ -61,6 +73,7 @@ int main(int, char**)
         return 1;
     glfwMakeContextCurrent(window);
     glfwSwapInterval(1); // Enable vsync
+    g_AppWindow = window;
 
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
@@ -97,6 +110,7 @@ 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);
@@ -105,85 +119,16 @@ 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__
     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, 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.
-        glfwPollEvents();
-
-        // Start the Dear ImGui frame
-        ImGui_ImplOpenGL3_NewFrame();
-        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 create 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();
-        int display_w, display_h;
-        glfwGetFramebufferSize(window, &display_w, &display_h);
-        glViewport(0, 0, display_w, display_h);
-        glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
-        glClear(GL_COLOR_BUFFER_BIT);
-        ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
-    	
-        // Update and Render additional Platform Windows
-        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
-        //  For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
-        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
-        {
-            GLFWwindow* backup_current_context = glfwGetCurrentContext();
-            ImGui::UpdatePlatformWindows();
-            ImGui::RenderPlatformWindowsDefault();
-            glfwMakeContextCurrent(backup_current_context);
-        }
-
-        glfwSwapBuffers(window);
-    }
+        MainLoopStep();
+#else
+    // 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();
@@ -195,3 +140,84 @@ int main(int, char**)
 
     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
+    ImGui_ImplOpenGL3_NewFrame();
+    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);
+
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create 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();
+    int display_w, display_h;
+    glfwGetFramebufferSize(window, &display_w, &display_h);
+    glViewport(0, 0, display_w, display_h);
+    glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
+    glClear(GL_COLOR_BUFFER_BIT);
+    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+
+    // Update and Render additional Platform Windows
+    // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+    //  For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        GLFWwindow* backup_current_context = glfwGetCurrentContext();
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+        glfwMakeContextCurrent(backup_current_context);
+    }
+
+    glfwSwapBuffers(window);
+}

examples/example_glfw_vulkan/main.cpp

@@ -31,6 +31,7 @@
 #define IMGUI_VULKAN_DEBUG_REPORT
 #endif
 
+// Data
 static VkAllocationCallbacks*   g_Allocator = NULL;
 static VkInstance               g_Instance = VK_NULL_HANDLE;
 static VkPhysicalDevice         g_PhysicalDevice = VK_NULL_HANDLE;
@@ -41,10 +42,17 @@ 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);
+}
 static void check_vk_result(VkResult err)
 {
     if (err == 0)
@@ -347,22 +355,16 @@ static void FramePresent(ImGui_ImplVulkanH_Window* wd)
     wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->ImageCount; // Now we can use the next set of semaphores
 }
 
-static void glfw_error_callback(int error, const char* description)
-{
-    fprintf(stderr, "Glfw Error %d: %s\n", error, description);
-}
-
+// Main code
 int main(int, char**)
 {
-    // Setup GLFW window
     glfwSetErrorCallback(glfw_error_callback);
     if (!glfwInit())
         return 1;
 
+    // Create window with Vulkan context
     glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
     GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+Vulkan example", NULL, NULL);
-
-    // Setup Vulkan
     if (!glfwVulkanSupported())
     {
         printf("GLFW: Vulkan Not Supported\n");
@@ -371,6 +373,7 @@ 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;
@@ -470,112 +473,118 @@ 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))
-    {
-        // 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.
-        glfwPollEvents();
-
-        // Resize swap chain?
-        if (g_SwapChainRebuild)
-        {
-            int width, height;
-            glfwGetFramebufferSize(window, &width, &height);
-            if (width > 0 && height > 0)
-            {
-                ImGui_ImplVulkan_SetMinImageCount(g_MinImageCount);
-                ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, &g_MainWindowData, g_QueueFamily, g_Allocator, width, height, g_MinImageCount);
-                g_MainWindowData.FrameIndex = 0;
-                g_SwapChainRebuild = false;
-            }
-        }
+        MainLoopStep();
 
-        // Start the Dear ImGui frame
-        ImGui_ImplVulkan_NewFrame();
-        ImGui_ImplGlfw_NewFrame();
-        ImGui::NewFrame();
+    // Cleanup
+    err = vkDeviceWaitIdle(g_Device);
+    check_vk_result(err);
+    ImGui_ImplVulkan_Shutdown();
+    ImGui_ImplGlfw_Shutdown();
+    ImGui::DestroyContext();
 
-        // 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);
+    CleanupVulkanWindow();
+    CleanupVulkan();
 
-        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    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?
+    if (g_SwapChainRebuild)
+    {
+        int width, height;
+        glfwGetFramebufferSize(window, &width, &height);
+        if (width > 0 && height > 0)
         {
-            static float f = 0.0f;
-            static int counter = 0;
+            ImGui_ImplVulkan_SetMinImageCount(g_MinImageCount);
+            ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, &g_MainWindowData, g_QueueFamily, g_Allocator, width, height, g_MinImageCount);
+            g_MainWindowData.FrameIndex = 0;
+            g_SwapChainRebuild = false;
+        }
+    }
 
-            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+    // Start the Dear ImGui frame
+    ImGui_ImplVulkan_NewFrame();
+    ImGui_ImplGlfw_NewFrame();
+    ImGui::NewFrame();
 
-            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);
+    // 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);
 
-            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
+    // 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);
 
-            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
-                counter++;
-            ImGui::SameLine();
-            ImGui::Text("counter = %d", counter);
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    {
+        static float f = 0.0f;
+        static int counter = 0;
 
-            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
-            ImGui::End();
-        }
+        ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
 
-        // 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();
-        }
+        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);
 
-        // Rendering
-        ImGui::Render();
-        ImDrawData* main_draw_data = ImGui::GetDrawData();
-        const bool main_is_minimized = (main_draw_data->DisplaySize.x <= 0.0f || main_draw_data->DisplaySize.y <= 0.0f);
-        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;
-        wd->ClearValue.color.float32[3] = clear_color.w;
-        if (!main_is_minimized)
-            FrameRender(wd, main_draw_data);
-
-        // Update and Render additional Platform Windows
-        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
-        {
-            ImGui::UpdatePlatformWindows();
-            ImGui::RenderPlatformWindowsDefault();
-        }
+        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
 
-        // Present Main Platform Window
-        if (!main_is_minimized)
-            FramePresent(wd);
-    }
+        if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+            counter++;
+        ImGui::SameLine();
+        ImGui::Text("counter = %d", counter);
 
-    // Cleanup
-    err = vkDeviceWaitIdle(g_Device);
-    check_vk_result(err);
-    ImGui_ImplVulkan_Shutdown();
-    ImGui_ImplGlfw_Shutdown();
-    ImGui::DestroyContext();
+        ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
+        ImGui::End();
+    }
 
-    CleanupVulkanWindow();
-    CleanupVulkan();
+    // 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();
+    }
 
-    glfwDestroyWindow(window);
-    glfwTerminate();
+    // Rendering
+    ImGui::Render();
+    ImDrawData* main_draw_data = ImGui::GetDrawData();
+    const bool main_is_minimized = (main_draw_data->DisplaySize.x <= 0.0f || main_draw_data->DisplaySize.y <= 0.0f);
+    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;
+    wd->ClearValue.color.float32[3] = clear_color.w;
+    if (!main_is_minimized)
+        FrameRender(wd, main_draw_data);
+
+    // Update and Render additional Platform Windows
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+    }
 
-    return 0;
+    // Present Main Platform Window
+    if (!main_is_minimized)
+        FramePresent(wd);
 }

examples/example_glut_opengl2/main.cpp

@@ -19,86 +19,23 @@
 #include "imgui_impl_opengl2.h"
 #define GL_SILENCE_DEPRECATION
 #ifdef __APPLE__
-    #include <GLUT/glut.h>
+#include <GLUT/glut.h>
 #else
-    #include <GL/freeglut.h>
+#include <GL/freeglut.h>
 #endif
 
 #ifdef _MSC_VER
 #pragma warning (disable: 4505) // unreferenced local function has been removed
 #endif
 
+// Forward declarations of helper functions
+void MainLoopStep();
+
 // Our state
 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);
 
-void my_display_code()
-{
-    // 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 create 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();
-    }
-}
-
-void glut_display_func()
-{
-    // Start the Dear ImGui frame
-    ImGui_ImplOpenGL2_NewFrame();
-    ImGui_ImplGLUT_NewFrame();
-
-    my_display_code();
-
-    // Rendering
-    ImGui::Render();
-    ImGuiIO& io = ImGui::GetIO();
-    glViewport(0, 0, (GLsizei)io.DisplaySize.x, (GLsizei)io.DisplaySize.y);
-    glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
-    glClear(GL_COLOR_BUFFER_BIT);
-    //glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context where shaders may be bound, but prefer using the GL3+ code.
-    ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
-
-    glutSwapBuffers();
-    glutPostRedisplay();
-}
-
-// 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.
-
 int main(int argc, char** argv)
 {
     // Create GLUT window
@@ -113,7 +50,7 @@ int main(int argc, char** argv)
     // Setup GLUT display function
     // We will also call ImGui_ImplGLUT_InstallFuncs() to get all the other functions installed for us,
     // otherwise it is possible to install our own functions and call the imgui_impl_glut.h functions ourselves.
-    glutDisplayFunc(glut_display_func);
+    glutDisplayFunc(MainLoopStep);
 
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
@@ -129,9 +66,15 @@ int main(int argc, char** argv)
     // Setup Platform/Renderer backends
     // FIXME: Consider reworking this example to install our own GLUT funcs + forward calls ImGui_ImplGLUT_XXX ones, instead of using ImGui_ImplGLUT_InstallFuncs().
     ImGui_ImplGLUT_Init();
-    ImGui_ImplGLUT_InstallFuncs();
     ImGui_ImplOpenGL2_Init();
 
+    // Install GLUT handlers (glutReshapeFunc(), glutMotionFunc(), glutPassiveMotionFunc(), glutMouseFunc(), glutKeyboardFunc() 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.
+    ImGui_ImplGLUT_InstallFuncs();
+
     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
@@ -148,6 +91,7 @@ int main(int argc, char** argv)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
+    // Main loop
     glutMainLoop();
 
     // Cleanup
@@ -157,3 +101,59 @@ int main(int argc, char** argv)
 
     return 0;
 }
+
+void MainLoopStep()
+{
+    // Start the Dear ImGui frame
+    ImGui_ImplOpenGL2_NewFrame();
+    ImGui_ImplGLUT_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 create 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();
+    ImGuiIO& io = ImGui::GetIO();
+    glViewport(0, 0, (GLsizei)io.DisplaySize.x, (GLsizei)io.DisplaySize.y);
+    glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
+    glClear(GL_COLOR_BUFFER_BIT);
+    //glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context where shaders may be bound, but prefer using the GL3+ code.
+    ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
+
+    glutSwapBuffers();
+    glutPostRedisplay();
+}

examples/example_sdl_directx11/main.cpp

@@ -12,12 +12,14 @@
 #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();
@@ -42,6 +44,7 @@ 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))
@@ -93,111 +96,119 @@ 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
-    bool done = false;
-    while (!done)
+    while (true)
     {
-        // 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_Event event;
-        while (SDL_PollEvent(&event))
-        {
-            ImGui_ImplSDL2_ProcessEvent(&event);
-            if (event.type == SDL_QUIT)
-                done = true;
-            if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
-                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.
-                CleanupRenderTarget();
-                g_pSwapChain->ResizeBuffers(0, 0, 0, DXGI_FORMAT_UNKNOWN, 0);
-                CreateRenderTarget();
-            }
-        }
+        if (!MainLoopStep())
+            break;
+    }
 
-        // Start the Dear ImGui frame
-        ImGui_ImplDX11_NewFrame();
-        ImGui_ImplSDL2_NewFrame();
-        ImGui::NewFrame();
+    // Cleanup
+    ImGui_ImplDX11_Shutdown();
+    ImGui_ImplSDL2_Shutdown();
+    ImGui::DestroyContext();
 
-        // 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);
+    CleanupDeviceD3D();
+    SDL_DestroyWindow(window);
+    SDL_Quit();
 
-        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    return 0;
+}
+
+bool MainLoopStep()
+{
+    // Poll and handle SDL 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;
+        if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
+            return false;
+        if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_RESIZED && event.window.windowID == SDL_GetWindowID(window))
         {
-            static float f = 0.0f;
-            static int counter = 0;
+            // Release all outstanding references to the swap chain's buffers before resizing.
+            CleanupRenderTarget();
+            g_pSwapChain->ResizeBuffers(0, 0, 0, DXGI_FORMAT_UNKNOWN, 0);
+            CreateRenderTarget();
+        }
+    }
 
-            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+    // Start the Dear ImGui frame
+    ImGui_ImplDX11_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);
 
-            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);
+    // 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);
 
-            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
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    {
+        static float f = 0.0f;
+        static int counter = 0;
 
-            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::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
 
-            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
-            ImGui::End();
-        }
+        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);
 
-        // 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();
-        }
+        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
 
-        // Rendering
-        ImGui::Render();
-        const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
-        g_pd3dDeviceContext->OMSetRenderTargets(1, &g_mainRenderTargetView, NULL);
-        g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
-        ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
+        if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+            counter++;
+        ImGui::SameLine();
+        ImGui::Text("counter = %d", counter);
 
-        // Update and Render additional Platform Windows
-        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
-        {
-            ImGui::UpdatePlatformWindows();
-            ImGui::RenderPlatformWindowsDefault();
-        }
+        ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
+        ImGui::End();
+    }
 
-        g_pSwapChain->Present(1, 0); // Present with vsync
-        //g_pSwapChain->Present(0, 0); // Present without vsync
+    // 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();
     }
 
-    // Cleanup
-    ImGui_ImplDX11_Shutdown();
-    ImGui_ImplSDL2_Shutdown();
-    ImGui::DestroyContext();
+    // Rendering
+    ImGui::Render();
+    const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
+    g_pd3dDeviceContext->OMSetRenderTargets(1, &g_mainRenderTargetView, NULL);
+    g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
+    ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
 
-    CleanupDeviceD3D();
-    SDL_DestroyWindow(window);
-    SDL_Quit();
+    // Update and Render additional Platform Windows
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+    }
 
-    return 0;
-}
+    g_pSwapChain->Present(1, 0); // Present with vsync
+    //g_pSwapChain->Present(0, 0); // Present without vsync
 
-// Helper functions
+    return true;
+}
 
+// Helper functions to use DirectX11
 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain

examples/example_sdl_opengl2/main.cpp

@@ -14,12 +14,16 @@
 #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**)
 {
     // Setup SDL
-    // (Some versions of SDL before <2.0.10 appears to have performance/stalling issues on a minority of Windows systems,
-    // depending on whether SDL_INIT_GAMECONTROLLER is enabled or disabled.. updating to the latest version of SDL is recommended!)
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
@@ -37,6 +41,7 @@ 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();
@@ -81,93 +86,11 @@ 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
-    bool done = false;
-    while (!done)
+    while (true)
     {
-        // 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_Event event;
-        while (SDL_PollEvent(&event))
-        {
-            ImGui_ImplSDL2_ProcessEvent(&event);
-            if (event.type == SDL_QUIT)
-                done = true;
-            if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
-                done = true;
-        }
-
-        // Start the Dear ImGui frame
-        ImGui_ImplOpenGL2_NewFrame();
-        ImGui_ImplSDL2_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 create 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();
-        glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
-        glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
-        glClear(GL_COLOR_BUFFER_BIT);
-        //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());
-
-        // Update and Render additional Platform Windows
-        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
-        //  For this specific demo app we could also call SDL_GL_MakeCurrent(window, gl_context) directly)
-        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
-        {
-            SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
-            SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
-            ImGui::UpdatePlatformWindows();
-            ImGui::RenderPlatformWindowsDefault();
-            SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
-        }
-
-        SDL_GL_SwapWindow(window);
+        if (!MainLoopStep())
+            break;
     }
 
     // Cleanup
@@ -181,3 +104,95 @@ int main(int, char**)
 
     return 0;
 }
+
+bool MainLoopStep()
+{
+    // Poll and handle SDL 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;
+        if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
+            return false;
+    }
+
+    // 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);
+
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create 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();
+    glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
+    glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
+    glClear(GL_COLOR_BUFFER_BIT);
+    //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());
+
+    // Update and Render additional Platform Windows
+    // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+    //  For this specific demo app we could also call SDL_GL_MakeCurrent(window, gl_context) directly)
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
+        SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+        SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
+    }
+
+    SDL_GL_SwapWindow(window);
+
+    return true;
+}

examples/example_emscripten_opengl3/Makefile → examples/example_sdl_opengl3/Makefile.emscripten

@@ -6,7 +6,7 @@
 # This Makefile assumes you have loaded emscripten's environment.
 # (On Windows, you may need to execute emsdk_env.bat or encmdprompt.bat ahead)
 #
-# Running `make` will produce three files:
+# Running `make -f Makefile.emscripten` will produce three files:
 #  - web/index.html
 #  - web/index.js
 #  - web/index.wasm
@@ -60,7 +60,8 @@ endif
 CPPFLAGS += -I$(IMGUI_DIR) -I$(IMGUI_DIR)/backends
 #CPPFLAGS += -g
 CPPFLAGS += -Wall -Wformat -Os $(EMS)
-LDFLAGS += --shell-file shell_minimal.html $(EMS)
+LDFLAGS += --shell-file ../libs/emscripten/shell_minimal.html
+LDFLAGS += $(EMS)
 
 ##---------------------------------------------------------------------
 ## BUILD RULES

examples/example_sdl_opengl3/README.md

@@ -1,12 +1,13 @@
 
 # How to Build
 
-- On Windows with Visual Studio's IDE
+## Windows with Visual Studio's IDE
 
 Use the provided project file (.vcxproj). Add to solution (imgui_examples.sln) if necessary.
 
-- On Windows with Visual Studio's CLI
+## Windows with Visual Studio's CLI
 
+Use build_win32.bat or directly:
 ```
 set SDL2_DIR=path_to_your_sdl2_folder
 cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib opengl32.lib /subsystem:console
@@ -15,15 +16,42 @@ cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_
 cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x64 SDL2.lib SDL2main.lib opengl32.lib /subsystem:console
 ```
 
-- On Linux and similar Unixes
+## Linux and similar Unixes
 
+Use our Makefile or directly:
 ```
-c++ `sdl2-config --cflags` -I .. -I ../.. -I ../../backends main.cpp ../../backends/imgui_impl_sdl.cpp ../../backends/imgui_impl_opengl3.cpp ../../imgui*.cpp `sdl2-config --libs` -lGL -ldl
+c++ `sdl2-config --cflags` -I .. -I ../.. -I ../../backends
+  main.cpp ../../backends/imgui_impl_sdl.cpp ../../backends/imgui_impl_opengl3.cpp ../../imgui*.cpp
+  `sdl2-config --libs` -lGL -ldl
 ```
 
-- On Mac OS X
+## macOS
 
+Use our Makefile or directly:
 ```
 brew install sdl2
-c++ `sdl2-config --cflags` -I .. -I ../.. -I ../../backends main.cpp ../../backends/imgui_impl_sdl.cpp ../../backends/imgui_impl_opengl3.cpp ../../imgui*.cpp `sdl2-config --libs` -framework OpenGl -framework CoreFoundation
+c++ `sdl2-config --cflags` -I .. -I ../.. -I ../../backends
+  main.cpp ../../backends/imgui_impl_sdl.cpp ../../backends/imgui_impl_opengl3.cpp ../../imgui*.cpp
+  `sdl2-config --libs` -framework OpenGl -framework CoreFoundation
 ```
+
+## Emscripten
+
+**Building**
+
+You need to install Emscripten from https://emscripten.org/docs/getting_started/downloads.html, and have the environment variables set, as described in https://emscripten.org/docs/getting_started/downloads.html#installation-instructions
+
+- Depending on your configuration, in Windows you may need to run `emsdk/emsdk_env.bat` in your console to access the Emscripten command-line tools.
+- You may also refer to our [Continuous Integration setup](https://github.com/ocornut/imgui/tree/master/.github/workflows) for Emscripten setup.
+- Then build using `make -f Makefile.emscripten` while in the current directory.
+
+**Running an Emscripten project**
+
+To run on a local machine:
+- `make -f Makefile.emscripten serve` will use Python3 to spawn a local webserver, you can then browse http://localhost:8000 to access your build.
+- Otherwise, generally you will need a local webserver. Quoting [https://emscripten.org/docs/getting_started](https://emscripten.org/docs/getting_started/Tutorial.html#generating-html):<br>
+_"Unfortunately several browsers (including Chrome, Safari, and Internet Explorer) do not support file:// [XHR](https://emscripten.org/docs/site/glossary.html#term-xhr) requests, and can’t load extra files needed by the HTML (like a .wasm file, or packaged file data as mentioned lower down). For these browsers you’ll need to serve the files using a [local webserver](https://emscripten.org/docs/getting_started/FAQ.html#faq-local-webserver) and then open http://localhost:8000/hello.html."_
+- Emscripten SDK has a handy `emrun` command: `emrun web/index.html --browser firefox` which will spawn a temporary local webserver (in Firefox). See https://emscripten.org/docs/compiling/Running-html-files-with-emrun.html for details.
+- You may use Python 3 builtin webserver: `python -m http.server -d web` (this is what `make serve` uses).
+- You may use Python 2 builtin webserver: `cd web && python -m SimpleHTTPServer`.
+- If you are accessing the files over a network, certain browsers, such as Firefox, will restrict Gamepad API access to secure contexts only (e.g. https only).

examples/example_sdl_opengl3/main.cpp

@@ -3,6 +3,8 @@
 // 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"
@@ -14,12 +16,20 @@
 #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**)
 {
     // Setup SDL
-    // (Some versions of SDL before <2.0.10 appears to have performance/stalling issues on a minority of Windows systems,
-    // depending on whether SDL_INIT_GAMECONTROLLER is enabled or disabled.. updating to the latest version of SDL is recommended!)
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
@@ -59,6 +69,7 @@ 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();
@@ -95,6 +106,7 @@ 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);
@@ -103,93 +115,21 @@ 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
-    bool done = false;
-    while (!done)
+#ifndef __EMSCRIPTEN__
+    // Desktop Build
+    while (true)
     {
-        // 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_Event event;
-        while (SDL_PollEvent(&event))
-        {
-            ImGui_ImplSDL2_ProcessEvent(&event);
-            if (event.type == SDL_QUIT)
-                done = true;
-            if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
-                done = true;
-        }
-
-        // Start the Dear ImGui frame
-        ImGui_ImplOpenGL3_NewFrame();
-        ImGui_ImplSDL2_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 create 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();
-        glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
-        glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
-        glClear(GL_COLOR_BUFFER_BIT);
-        ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
-
-        // Update and Render additional Platform Windows
-        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
-        //  For this specific demo app we could also call SDL_GL_MakeCurrent(window, gl_context) directly)
-        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
-        {
-            SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
-            SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
-            ImGui::UpdatePlatformWindows();
-            ImGui::RenderPlatformWindowsDefault();
-            SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
-        }
-
-        SDL_GL_SwapWindow(window);
+        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();
@@ -202,3 +142,94 @@ int main(int, char**)
 
     return 0;
 }
+
+bool MainLoopStep()
+{
+    // Poll and handle SDL 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;
+        if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
+            return false;
+    }
+
+    // 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);
+
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create 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();
+    glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
+    glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
+    glClear(GL_COLOR_BUFFER_BIT);
+    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+
+    // Update and Render additional Platform Windows
+    // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+    //  For this specific demo app we could also call SDL_GL_MakeCurrent(window, gl_context) directly)
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
+        SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+        SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
+    }
+
+    SDL_GL_SwapWindow(window);
+
+    return true;
+}

examples/example_sdl_sdlrenderer/main.cpp

@@ -17,29 +17,34 @@
 #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**)
 {
     // Setup SDL
-    // (Some versions of SDL before <2.0.10 appears to have performance/stalling issues on a minority of Windows systems,
-    // depending on whether SDL_INIT_GAMECONTROLLER is enabled or disabled.. updating to the latest version of SDL is recommended!)
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
         return -1;
     }
 
-    // Setup window
+    // Create window with SDL_Renderer graphics context
     SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
     SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+SDL_Renderer example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
-
-    // Setup SDL_Renderer instance
     SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);
     if (renderer == NULL)
     {
         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);
@@ -75,79 +80,11 @@ 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
-    bool done = false;
-    while (!done)
+    while (true)
     {
-        // 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_Event event;
-        while (SDL_PollEvent(&event))
-        {
-            ImGui_ImplSDL2_ProcessEvent(&event);
-            if (event.type == SDL_QUIT)
-                done = true;
-            if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
-                done = true;
-        }
-
-        // Start the Dear ImGui frame
-        ImGui_ImplSDLRenderer_NewFrame();
-        ImGui_ImplSDL2_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 create 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();
-        SDL_RenderSetScale(renderer, io.DisplayFramebufferScale.x, io.DisplayFramebufferScale.y);
-        SDL_SetRenderDrawColor(renderer, (Uint8)(clear_color.x * 255), (Uint8)(clear_color.y * 255), (Uint8)(clear_color.z * 255), (Uint8)(clear_color.w * 255));
-        SDL_RenderClear(renderer);
-        ImGui_ImplSDLRenderer_RenderDrawData(ImGui::GetDrawData());
-        SDL_RenderPresent(renderer);
+        if (!MainLoopStep())
+            break;
     }
 
     // Cleanup
@@ -161,3 +98,82 @@ int main(int, char**)
 
     return 0;
 }
+
+bool 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.
+    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;
+        if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
+            return false;
+    }
+
+    // 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);
+
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create 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();
+    SDL_RenderSetScale(renderer, io.DisplayFramebufferScale.x, io.DisplayFramebufferScale.y);
+    SDL_SetRenderDrawColor(renderer, (Uint8)(clear_color.x * 255), (Uint8)(clear_color.y * 255), (Uint8)(clear_color.z * 255), (Uint8)(clear_color.w * 255));
+    SDL_RenderClear(renderer);
+    ImGui_ImplSDLRenderer_RenderDrawData(ImGui::GetDrawData());
+    SDL_RenderPresent(renderer);
+
+    return true;
+}

examples/example_sdl_vulkan/example_sdl_vulkan.vcxproj.filters

@@ -32,7 +32,7 @@
       <Filter>imgui</Filter>
     </ClCompile>
     <ClCompile Include="..\..\imgui_tables.cpp">
-      <Filter>sources</Filter>
+      <Filter>imgui</Filter>
     </ClCompile>
   </ItemGroup>
   <ItemGroup>

examples/example_sdl_vulkan/main.cpp

@@ -23,6 +23,7 @@
 #define IMGUI_VULKAN_DEBUG_REPORT
 #endif
 
+// Data
 static VkAllocationCallbacks*   g_Allocator = NULL;
 static VkInstance               g_Instance = VK_NULL_HANDLE;
 static VkPhysicalDevice         g_PhysicalDevice = VK_NULL_HANDLE;
@@ -33,10 +34,14 @@ 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)
@@ -339,6 +344,7 @@ static void FramePresent(ImGui_ImplVulkanH_Window* wd)
     wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->ImageCount; // Now we can use the next set of semaphores
 }
 
+// Main code
 int main(int, char**)
 {
     // Setup SDL
@@ -348,17 +354,16 @@ int main(int, char**)
         return -1;
     }
 
-    // Setup window
+    // Create window with Vulkan graphics context
     SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_VULKAN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
     SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+Vulkan example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
-
-    // Setup Vulkan
     uint32_t extensions_count = 0;
     SDL_Vulkan_GetInstanceExtensions(window, &extensions_count, NULL);
     const char** extensions = new const char*[extensions_count];
     SDL_Vulkan_GetInstanceExtensions(window, &extensions_count, extensions);
     SetupVulkan(extensions, extensions_count);
     delete[] extensions;
+    g_AppWindow = window;
 
     // Create Window Surface
     VkSurfaceKHR surface;
@@ -462,121 +467,131 @@ 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
-    bool done = false;
-    while (!done)
+    while (true)
     {
-        // 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_Event event;
-        while (SDL_PollEvent(&event))
-        {
-            ImGui_ImplSDL2_ProcessEvent(&event);
-            if (event.type == SDL_QUIT)
-                done = true;
-            if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
-                done = true;
-        }
+        if (!MainLoopStep())
+            break;
+    }
 
-        // Resize swap chain?
-        if (g_SwapChainRebuild)
-        {
-            int width, height;
-            SDL_GetWindowSize(window, &width, &height);
-            if (width > 0 && height > 0)
-            {
-                ImGui_ImplVulkan_SetMinImageCount(g_MinImageCount);
-                ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, &g_MainWindowData, g_QueueFamily, g_Allocator, width, height, g_MinImageCount);
-                g_MainWindowData.FrameIndex = 0;
-                g_SwapChainRebuild = false;
-            }
-        }
+    // Cleanup
+    err = vkDeviceWaitIdle(g_Device);
+    check_vk_result(err);
+    ImGui_ImplVulkan_Shutdown();
+    ImGui_ImplSDL2_Shutdown();
+    ImGui::DestroyContext();
+
+    CleanupVulkanWindow();
+    CleanupVulkan();
+
+    SDL_DestroyWindow(window);
+    SDL_Quit();
 
-        // Start the Dear ImGui frame
-        ImGui_ImplVulkan_NewFrame();
-        ImGui_ImplSDL2_NewFrame();
-        ImGui::NewFrame();
+    return 0;
+}
 
-        // 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);
+bool 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.
+    SDL_Window* window = g_AppWindow;
+    SDL_Event event;
+    while (SDL_PollEvent(&event))
+    {
+        ImGui_ImplSDL2_ProcessEvent(&event);
+        if (event.type == SDL_QUIT)
+            return false;
+        if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
+            return false;
+    }
 
-        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    // Resize swap chain?
+    if (g_SwapChainRebuild)
+    {
+        int width, height;
+        SDL_GetWindowSize(window, &width, &height);
+        if (width > 0 && height > 0)
         {
-            static float f = 0.0f;
-            static int counter = 0;
+            ImGui_ImplVulkan_SetMinImageCount(g_MinImageCount);
+            ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, &g_MainWindowData, g_QueueFamily, g_Allocator, width, height, g_MinImageCount);
+            g_MainWindowData.FrameIndex = 0;
+            g_SwapChainRebuild = false;
+        }
+    }
 
-            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+    // Start the Dear ImGui frame
+    ImGui_ImplVulkan_NewFrame();
+    ImGui_ImplSDL2_NewFrame();
+    ImGui::NewFrame();
 
-            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);
+    // 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);
 
-            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
+    // 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);
 
-            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
-                counter++;
-            ImGui::SameLine();
-            ImGui::Text("counter = %d", counter);
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    {
+        static float f = 0.0f;
+        static int counter = 0;
 
-            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
-            ImGui::End();
-        }
+        ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
 
-        // 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();
-        }
+        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);
 
-        // Rendering
-        ImGui::Render();
-        ImDrawData* main_draw_data = ImGui::GetDrawData();
-        const bool main_is_minimized = (main_draw_data->DisplaySize.x <= 0.0f || main_draw_data->DisplaySize.y <= 0.0f);
-        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;
-        wd->ClearValue.color.float32[3] = clear_color.w;
-        if (!main_is_minimized)
-            FrameRender(wd, main_draw_data);
-
-        // Update and Render additional Platform Windows
-        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
-        {
-            ImGui::UpdatePlatformWindows();
-            ImGui::RenderPlatformWindowsDefault();
-        }
+        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
 
-        // Present Main Platform Window
-        if (!main_is_minimized)
-            FramePresent(wd);
+        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();
     }
 
-    // Cleanup
-    err = vkDeviceWaitIdle(g_Device);
-    check_vk_result(err);
-    ImGui_ImplVulkan_Shutdown();
-    ImGui_ImplSDL2_Shutdown();
-    ImGui::DestroyContext();
+    // 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();
+    }
 
-    CleanupVulkanWindow();
-    CleanupVulkan();
+    // Rendering
+    ImGui::Render();
+    ImDrawData* main_draw_data = ImGui::GetDrawData();
+    const bool main_is_minimized = (main_draw_data->DisplaySize.x <= 0.0f || main_draw_data->DisplaySize.y <= 0.0f);
+    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;
+    wd->ClearValue.color.float32[3] = clear_color.w;
+    if (!main_is_minimized)
+        FrameRender(wd, main_draw_data);
+
+    // Update and Render additional Platform Windows
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+    }
 
-    SDL_DestroyWindow(window);
-    SDL_Quit();
+    // Present Main Platform Window
+    if (!main_is_minimized)
+        FramePresent(wd);
 
-    return 0;
+    return true;
 }

examples/example_win32_directx10/main.cpp

@@ -15,6 +15,7 @@ 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();
@@ -85,97 +86,107 @@ 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
-    bool done = false;
-    while (!done)
+    while (true)
     {
-        // Poll and handle messages (inputs, window resize, etc.)
-        // See the WndProc() function below for our to dispatch events to the Win32 backend.
-        MSG msg;
-        while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
-        {
-            ::TranslateMessage(&msg);
-            ::DispatchMessage(&msg);
-            if (msg.message == WM_QUIT)
-                done = true;
-        }
-        if (done)
+        if (!MainLoopStep())
             break;
+    }
 
-        // Start the Dear ImGui frame
-        ImGui_ImplDX10_NewFrame();
-        ImGui_ImplWin32_NewFrame();
-        ImGui::NewFrame();
+    // Cleanup
+    ImGui_ImplDX10_Shutdown();
+    ImGui_ImplWin32_Shutdown();
+    ImGui::DestroyContext();
 
-        // 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);
+    CleanupDeviceD3D();
+    ::DestroyWindow(hwnd);
+    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
 
-        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
-        {
-            static float f = 0.0f;
-            static int counter = 0;
+    return 0;
+}
+
+bool MainLoopStep()
+{
+    // 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;
+    MSG msg;
+    while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
+    {
+        ::TranslateMessage(&msg);
+        ::DispatchMessage(&msg);
+        if (msg.message == WM_QUIT)
+            done = true;
+    }
+    if (done)
+        return false;
 
-            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+    // Start the Dear ImGui frame
+    ImGui_ImplDX10_NewFrame();
+    ImGui_ImplWin32_NewFrame();
+    ImGui::NewFrame();
 
-            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);
+    // 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);
 
-            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
+    // 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);
 
-            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
-                counter++;
-            ImGui::SameLine();
-            ImGui::Text("counter = %d", counter);
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    {
+        static float f = 0.0f;
+        static int counter = 0;
 
-            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
-            ImGui::End();
-        }
+        ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
 
-        // 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();
-        }
+        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);
 
-        // Rendering
-        ImGui::Render();
-        const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
-        g_pd3dDevice->OMSetRenderTargets(1, &g_mainRenderTargetView, NULL);
-        g_pd3dDevice->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
-        ImGui_ImplDX10_RenderDrawData(ImGui::GetDrawData());
+        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
 
-        // Update and Render additional Platform Windows
-        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
-        {
-            ImGui::UpdatePlatformWindows();
-            ImGui::RenderPlatformWindowsDefault();
-        }
+        if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+            counter++;
+        ImGui::SameLine();
+        ImGui::Text("counter = %d", counter);
 
-        g_pSwapChain->Present(1, 0); // Present with vsync
-        //g_pSwapChain->Present(0, 0); // Present without vsync
+        ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
+        ImGui::End();
     }
 
-    ImGui_ImplDX10_Shutdown();
-    ImGui_ImplWin32_Shutdown();
-    ImGui::DestroyContext();
+    // 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();
+    }
 
-    CleanupDeviceD3D();
-    ::DestroyWindow(hwnd);
-    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
+    // Rendering
+    ImGui::Render();
+    const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
+    g_pd3dDevice->OMSetRenderTargets(1, &g_mainRenderTargetView, NULL);
+    g_pd3dDevice->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
+    ImGui_ImplDX10_RenderDrawData(ImGui::GetDrawData());
 
-    return 0;
+    // Update and Render additional Platform Windows
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+    }
+
+    g_pSwapChain->Present(1, 0); // Present with vsync
+    //g_pSwapChain->Present(0, 0); // Present without vsync
+
+    return true;
 }
 
 // Helper functions

examples/example_win32_directx11/main.cpp

@@ -15,6 +15,7 @@ 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();
@@ -90,98 +91,106 @@ 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
-    bool done = false;
-    while (!done)
+    while (true)
     {
-        // Poll and handle messages (inputs, window resize, etc.)
-        // See the WndProc() function below for our to dispatch events to the Win32 backend.
-        MSG msg;
-        while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
-        {
-            ::TranslateMessage(&msg);
-            ::DispatchMessage(&msg);
-            if (msg.message == WM_QUIT)
-                done = true;
-        }
-        if (done)
+        if (!MainLoopStep())
             break;
+    }
 
-        // Start the Dear ImGui frame
-        ImGui_ImplDX11_NewFrame();
-        ImGui_ImplWin32_NewFrame();
-        ImGui::NewFrame();
+    // Cleanup
+    ImGui_ImplDX11_Shutdown();
+    ImGui_ImplWin32_Shutdown();
+    ImGui::DestroyContext();
 
-        // 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);
+    CleanupDeviceD3D();
+    ::DestroyWindow(hwnd);
+    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
 
-        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
-        {
-            static float f = 0.0f;
-            static int counter = 0;
+    return 0;
+}
 
-            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+bool MainLoopStep()
+{
+    // 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;
+    MSG msg;
+    while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
+    {
+        ::TranslateMessage(&msg);
+        ::DispatchMessage(&msg);
+        if (msg.message == WM_QUIT)
+            done = true;
+    }
+    if (done)
+        return false;
 
-            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);
+    // Start the Dear ImGui frame
+    ImGui_ImplDX11_NewFrame();
+    ImGui_ImplWin32_NewFrame();
+    ImGui::NewFrame();
 
-            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
+    // 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);
 
-            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
-                counter++;
-            ImGui::SameLine();
-            ImGui::Text("counter = %d", counter);
+    // 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);
 
-            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
-            ImGui::End();
-        }
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    {
+        static float f = 0.0f;
+        static int counter = 0;
 
-        // 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();
-        }
+        ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
 
-        // Rendering
-        ImGui::Render();
-        const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
-        g_pd3dDeviceContext->OMSetRenderTargets(1, &g_mainRenderTargetView, NULL);
-        g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
-        ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
+        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);
 
-        // Update and Render additional Platform Windows
-        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
-        {
-            ImGui::UpdatePlatformWindows();
-            ImGui::RenderPlatformWindowsDefault();
-        }
+        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
 
-        g_pSwapChain->Present(1, 0); // Present with vsync
-        //g_pSwapChain->Present(0, 0); // Present without vsync
+        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();
     }
 
-    // Cleanup
-    ImGui_ImplDX11_Shutdown();
-    ImGui_ImplWin32_Shutdown();
-    ImGui::DestroyContext();
+    // 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();
+    }
 
-    CleanupDeviceD3D();
-    ::DestroyWindow(hwnd);
-    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
+    // Rendering
+    ImGui::Render();
+    const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
+    g_pd3dDeviceContext->OMSetRenderTargets(1, &g_mainRenderTargetView, NULL);
+    g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
+    ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
 
-    return 0;
+    // Update and Render additional Platform Windows
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+    }
+
+    g_pSwapChain->Present(1, 0); // Present with vsync
+    //g_pSwapChain->Present(0, 0); // Present without vsync
+    return true;
 }
 
 // Helper functions

examples/example_win32_directx12/main.cpp

@@ -48,6 +48,7 @@ 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();
@@ -123,128 +124,136 @@ 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
-    bool done = false;
-    while (!done)
+    while (true)
     {
-        // Poll and handle messages (inputs, window resize, etc.)
-        // See the WndProc() function below for our to dispatch events to the Win32 backend.
-        MSG msg;
-        while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
-        {
-            ::TranslateMessage(&msg);
-            ::DispatchMessage(&msg);
-            if (msg.message == WM_QUIT)
-                done = true;
-        }
-        if (done)
+        if (!MainLoopStep())
             break;
+    }
 
-        // Start the Dear ImGui frame
-        ImGui_ImplDX12_NewFrame();
-        ImGui_ImplWin32_NewFrame();
-        ImGui::NewFrame();
+    // Cleanup
+    WaitForLastSubmittedFrame();
+    ImGui_ImplDX12_Shutdown();
+    ImGui_ImplWin32_Shutdown();
+    ImGui::DestroyContext();
 
-        // 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);
+    CleanupDeviceD3D();
+    ::DestroyWindow(hwnd);
+    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
 
-        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
-        {
-            static float f = 0.0f;
-            static int counter = 0;
+    return 0;
+}
 
-            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+bool MainLoopStep()
+{
+    // 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;
+    MSG msg;
+    while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
+    {
+        ::TranslateMessage(&msg);
+        ::DispatchMessage(&msg);
+        if (msg.message == WM_QUIT)
+            done = true;
+    }
+    if (done)
+        return false;
 
-            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);
+    // Start the Dear ImGui frame
+    ImGui_ImplDX12_NewFrame();
+    ImGui_ImplWin32_NewFrame();
+    ImGui::NewFrame();
 
-            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
+    // 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);
 
-            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
-                counter++;
-            ImGui::SameLine();
-            ImGui::Text("counter = %d", counter);
+    // 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);
 
-            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
-            ImGui::End();
-        }
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    {
+        static float f = 0.0f;
+        static int counter = 0;
 
-        // 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();
-        }
+        ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
 
-        // Rendering
-        ImGui::Render();
-
-        FrameContext* frameCtx = WaitForNextFrameResources();
-        UINT backBufferIdx = g_pSwapChain->GetCurrentBackBufferIndex();
-        frameCtx->CommandAllocator->Reset();
-
-        D3D12_RESOURCE_BARRIER barrier = {};
-        barrier.Type                   = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;
-        barrier.Flags                  = D3D12_RESOURCE_BARRIER_FLAG_NONE;
-        barrier.Transition.pResource   = g_mainRenderTargetResource[backBufferIdx];
-        barrier.Transition.Subresource = D3D12_RESOURCE_BARRIER_ALL_SUBRESOURCES;
-        barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_PRESENT;
-        barrier.Transition.StateAfter  = D3D12_RESOURCE_STATE_RENDER_TARGET;
-        g_pd3dCommandList->Reset(frameCtx->CommandAllocator, NULL);
-        g_pd3dCommandList->ResourceBarrier(1, &barrier);
-
-        // Render Dear ImGui graphics
-        const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
-        g_pd3dCommandList->ClearRenderTargetView(g_mainRenderTargetDescriptor[backBufferIdx], clear_color_with_alpha, 0, NULL);
-        g_pd3dCommandList->OMSetRenderTargets(1, &g_mainRenderTargetDescriptor[backBufferIdx], FALSE, NULL);
-        g_pd3dCommandList->SetDescriptorHeaps(1, &g_pd3dSrvDescHeap);
-        ImGui_ImplDX12_RenderDrawData(ImGui::GetDrawData(), g_pd3dCommandList);
-        barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_RENDER_TARGET;
-        barrier.Transition.StateAfter  = D3D12_RESOURCE_STATE_PRESENT;
-        g_pd3dCommandList->ResourceBarrier(1, &barrier);
-        g_pd3dCommandList->Close();
-
-        g_pd3dCommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&g_pd3dCommandList);
-
-        // Update and Render additional Platform Windows
-        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
-        {
-            ImGui::UpdatePlatformWindows();
-            ImGui::RenderPlatformWindowsDefault(NULL, (void*)g_pd3dCommandList);
-        }
+        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);
 
-        g_pSwapChain->Present(1, 0); // Present with vsync
-        //g_pSwapChain->Present(0, 0); // Present without vsync
+        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
 
-        UINT64 fenceValue = g_fenceLastSignaledValue + 1;
-        g_pd3dCommandQueue->Signal(g_fence, fenceValue);
-        g_fenceLastSignaledValue = fenceValue;
-        frameCtx->FenceValue = fenceValue;
+        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();
     }
 
-    WaitForLastSubmittedFrame();
+    // 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();
+    }
 
-    // Cleanup
-    ImGui_ImplDX12_Shutdown();
-    ImGui_ImplWin32_Shutdown();
-    ImGui::DestroyContext();
+    // Rendering
+    ImGui::Render();
+
+    FrameContext* frameCtx = WaitForNextFrameResources();
+    UINT backBufferIdx = g_pSwapChain->GetCurrentBackBufferIndex();
+    frameCtx->CommandAllocator->Reset();
+
+    D3D12_RESOURCE_BARRIER barrier = {};
+    barrier.Type = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;
+    barrier.Flags = D3D12_RESOURCE_BARRIER_FLAG_NONE;
+    barrier.Transition.pResource = g_mainRenderTargetResource[backBufferIdx];
+    barrier.Transition.Subresource = D3D12_RESOURCE_BARRIER_ALL_SUBRESOURCES;
+    barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_PRESENT;
+    barrier.Transition.StateAfter = D3D12_RESOURCE_STATE_RENDER_TARGET;
+    g_pd3dCommandList->Reset(frameCtx->CommandAllocator, NULL);
+    g_pd3dCommandList->ResourceBarrier(1, &barrier);
+
+    // Render Dear ImGui graphics
+    const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
+    g_pd3dCommandList->ClearRenderTargetView(g_mainRenderTargetDescriptor[backBufferIdx], clear_color_with_alpha, 0, NULL);
+    g_pd3dCommandList->OMSetRenderTargets(1, &g_mainRenderTargetDescriptor[backBufferIdx], FALSE, NULL);
+    g_pd3dCommandList->SetDescriptorHeaps(1, &g_pd3dSrvDescHeap);
+    ImGui_ImplDX12_RenderDrawData(ImGui::GetDrawData(), g_pd3dCommandList);
+    barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_RENDER_TARGET;
+    barrier.Transition.StateAfter = D3D12_RESOURCE_STATE_PRESENT;
+    g_pd3dCommandList->ResourceBarrier(1, &barrier);
+    g_pd3dCommandList->Close();
+
+    g_pd3dCommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&g_pd3dCommandList);
+
+    // Update and Render additional Platform Windows
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault(NULL, (void*)g_pd3dCommandList);
+    }
 
-    CleanupDeviceD3D();
-    ::DestroyWindow(hwnd);
-    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
+    g_pSwapChain->Present(1, 0); // Present with vsync
+    //g_pSwapChain->Present(0, 0); // Present without vsync
 
-    return 0;
+    UINT64 fenceValue = g_fenceLastSignaledValue + 1;
+    g_pd3dCommandQueue->Signal(g_fence, fenceValue);
+    g_fenceLastSignaledValue = fenceValue;
+    frameCtx->FenceValue = fenceValue;
+
+    return true;
 }
 
 // Helper functions

examples/example_win32_directx9/main.cpp

@@ -14,6 +14,7 @@ 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();
@@ -83,107 +84,117 @@ 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
-    bool done = false;
-    while (!done)
+    while (true)
     {
-        // Poll and handle messages (inputs, window resize, etc.)
-        // See the WndProc() function below for our to dispatch events to the Win32 backend.
-        MSG msg;
-        while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
-        {
-            ::TranslateMessage(&msg);
-            ::DispatchMessage(&msg);
-            if (msg.message == WM_QUIT)
-                done = true;
-        }
-        if (done)
+        if (!MainLoopStep())
             break;
+    }
 
-        // Start the Dear ImGui frame
-        ImGui_ImplDX9_NewFrame();
-        ImGui_ImplWin32_NewFrame();
-        ImGui::NewFrame();
+    // Cleanup
+    ImGui_ImplDX9_Shutdown();
+    ImGui_ImplWin32_Shutdown();
+    ImGui::DestroyContext();
 
-        // 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);
+    CleanupDeviceD3D();
+    ::DestroyWindow(hwnd);
+    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
 
-        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
-        {
-            static float f = 0.0f;
-            static int counter = 0;
+    return 0;
+}
 
-            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+bool MainLoopStep()
+{
+    // 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;
+    MSG msg;
+    while (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
+    {
+        ::TranslateMessage(&msg);
+        ::DispatchMessage(&msg);
+        if (msg.message == WM_QUIT)
+            done = true;
+    }
+    if (done)
+        return false;
 
-            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);
+    // Start the Dear ImGui frame
+    ImGui_ImplDX9_NewFrame();
+    ImGui_ImplWin32_NewFrame();
+    ImGui::NewFrame();
 
-            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
+    // 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);
 
-            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
-                counter++;
-            ImGui::SameLine();
-            ImGui::Text("counter = %d", counter);
+    // 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);
 
-            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
-            ImGui::End();
-        }
+    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+    {
+        static float f = 0.0f;
+        static int counter = 0;
 
-        // 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();
-        }
+        ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
 
-        // Rendering
-        ImGui::EndFrame();
-        g_pd3dDevice->SetRenderState(D3DRS_ZENABLE, FALSE);
-        g_pd3dDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE);
-        g_pd3dDevice->SetRenderState(D3DRS_SCISSORTESTENABLE, FALSE);
-        D3DCOLOR clear_col_dx = D3DCOLOR_RGBA((int)(clear_color.x*clear_color.w*255.0f), (int)(clear_color.y*clear_color.w*255.0f), (int)(clear_color.z*clear_color.w*255.0f), (int)(clear_color.w*255.0f));
-        g_pd3dDevice->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, clear_col_dx, 1.0f, 0);
-        if (g_pd3dDevice->BeginScene() >= 0)
-        {
-            ImGui::Render();
-            ImGui_ImplDX9_RenderDrawData(ImGui::GetDrawData());
-            g_pd3dDevice->EndScene();
-        }
+        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);
 
-        // Update and Render additional Platform Windows
-        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
-        {
-            ImGui::UpdatePlatformWindows();
-            ImGui::RenderPlatformWindowsDefault();
-        }
+        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
 
-        HRESULT result = g_pd3dDevice->Present(NULL, NULL, NULL, NULL);
+        if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+            counter++;
+        ImGui::SameLine();
+        ImGui::Text("counter = %d", counter);
 
-        // Handle loss of D3D9 device
-        if (result == D3DERR_DEVICELOST && g_pd3dDevice->TestCooperativeLevel() == D3DERR_DEVICENOTRESET)
-            ResetDevice();
+        ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
+        ImGui::End();
     }
 
-    ImGui_ImplDX9_Shutdown();
-    ImGui_ImplWin32_Shutdown();
-    ImGui::DestroyContext();
+    // 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();
+    }
 
-    CleanupDeviceD3D();
-    ::DestroyWindow(hwnd);
-    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
+    // Rendering
+    ImGui::EndFrame();
+    g_pd3dDevice->SetRenderState(D3DRS_ZENABLE, FALSE);
+    g_pd3dDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE);
+    g_pd3dDevice->SetRenderState(D3DRS_SCISSORTESTENABLE, FALSE);
+    D3DCOLOR clear_col_dx = D3DCOLOR_RGBA((int)(clear_color.x * clear_color.w * 255.0f), (int)(clear_color.y * clear_color.w * 255.0f), (int)(clear_color.z * clear_color.w * 255.0f), (int)(clear_color.w * 255.0f));
+    g_pd3dDevice->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, clear_col_dx, 1.0f, 0);
+    if (g_pd3dDevice->BeginScene() >= 0)
+    {
+        ImGui::Render();
+        ImGui_ImplDX9_RenderDrawData(ImGui::GetDrawData());
+        g_pd3dDevice->EndScene();
+    }
 
-    return 0;
+    // Update and Render additional Platform Windows
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+    }
+
+    HRESULT result = g_pd3dDevice->Present(NULL, NULL, NULL, NULL);
+
+    // Handle loss of D3D9 device
+    if (result == D3DERR_DEVICELOST && g_pd3dDevice->TestCooperativeLevel() == D3DERR_DEVICENOTRESET)
+        ResetDevice();
+
+    return true;
 }
 
 // Helper functions

examples/example_emscripten_opengl3/shell_minimal.html → examples/libs/emscripten/shell_minimal.html

@@ -3,9 +3,10 @@
   <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no"/>
-    <title>Dear ImGui SDL+Emscripten example</title>
+    <title>Dear ImGui Emscripten example</title>
     <style>
         body { margin: 0; background-color: black }
+        /* FIXME: with our GLFW example this block seems to break resizing and io.DisplaySize gets stuck */
         .emscripten {
             position: absolute;
             top: 0px;

imgui_demo.cpp

@@ -6068,6 +6068,9 @@ void ImGui::ShowAboutWindow(bool* p_open)
 #ifdef __clang_version__
         ImGui::Text("define: __clang_version__=%s", __clang_version__);
 #endif
+#ifdef __EMSCRIPTEN__
+        ImGui::Text("define: __EMSCRIPTEN__");
+#endif
 #ifdef IMGUI_HAS_VIEWPORT
         ImGui::Text("define: IMGUI_HAS_VIEWPORT");
 #endif