Examples: Win32+Vulkan, GLFW+Metal: Fixed not applying content scale. (#8921, #8756)

Somehow it breaks in Win32+OpenGL3 example: when enabled Win32 applies some extra scale.

docs/CHANGELOG.txt

@@ -107,7 +107,8 @@ Other Changes:
   while navigating and to not close popup automatically.
 - CI: Updates Windows CI to use a more recent VulkanSDK. (#8925, #8778) [@yaz0r]
 - Examples: Android: Android+OpenGL3: update Gradle project (#8888, #8878) [@scribam]
-- Examples: GLFW+OpenGL2, GLFW+Vulkan: Fixed not applying content scale. (#8921, #8756)
+- Examples: GLFW+OpenGL2, GLFW+Vulkan, GLFW+Metal, Win32+Vulkan: Fixed not applying
+  content scale consistently with other examples. (#8921, #8756)
 - Backends: SDL3: use SDL_GetWindowDisplayScale() on Mac to obtain DisplayFrameBufferScale,
   fixing incorrect values during resolution changes e.g. going fullscreen.
   (#8703, #4414) [@jclounge]

examples/example_glfw_metal/main.mm

@@ -27,17 +27,40 @@ static void glfw_error_callback(int error, const char* description)
 
 int main(int, char**)
 {
+    glfwSetErrorCallback(glfw_error_callback);
+    if (!glfwInit())
+        return 1;
+
+    // Create window with graphics context
+    float main_scale = ImGui_ImplGlfw_GetContentScaleForMonitor(glfwGetPrimaryMonitor()); // Valid on GLFW 3.3+ only
+    glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
+    GLFWwindow* window = glfwCreateWindow((int)(1280 * main_scale), (int)(800 * main_scale), "Dear ImGui GLFW+Metal example", nullptr, nullptr);
+    if (window == nullptr)
+        return 1;
+
     // 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_NavEnableKeyboard;     // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
 
-    // Setup style
+    // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // Setup scaling
+    ImGuiStyle& style = ImGui::GetStyle();
+    style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+    style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+
+    id <MTLDevice> device = MTLCreateSystemDefaultDevice();
+    id <MTLCommandQueue> commandQueue = [device newCommandQueue];
+
+    // Setup Platform/Renderer backends
+    ImGui_ImplGlfw_InitForOpenGL(window, true);
+    ImGui_ImplMetal_Init(device);
+
     // 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.
@@ -54,24 +77,6 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf");
     //IM_ASSERT(font != nullptr);
 
-    // Setup window
-    glfwSetErrorCallback(glfw_error_callback);
-    if (!glfwInit())
-        return 1;
-
-    // Create window with graphics context
-    glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
-    GLFWwindow* window = glfwCreateWindow(1280, 800, "Dear ImGui GLFW+Metal example", nullptr, nullptr);
-    if (window == nullptr)
-        return 1;
-
-    id <MTLDevice> device = MTLCreateSystemDefaultDevice();
-    id <MTLCommandQueue> commandQueue = [device newCommandQueue];
-
-    // Setup Platform/Renderer backends
-    ImGui_ImplGlfw_InitForOpenGL(window, true);
-    ImGui_ImplMetal_Init(device);
-
     NSWindow *nswin = glfwGetCocoaWindow(window);
     CAMetalLayer *layer = [CAMetalLayer layer];
     layer.device = device;

examples/example_win32_opengl3/main.cpp

@@ -36,11 +36,14 @@ LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 // Main code
 int main(int, char**)
 {
+    // Make process DPI aware and obtain main monitor scale
+    //ImGui_ImplWin32_EnableDpiAwareness(); // FIXME: This somehow doesn't work in the Win32+OpenGL example. Why?
+    float main_scale = ImGui_ImplWin32_GetDpiScaleForMonitor(::MonitorFromPoint(POINT{ 0, 0 }, MONITOR_DEFAULTTOPRIMARY));
+
     // Create application window
-    //ImGui_ImplWin32_EnableDpiAwareness();
     WNDCLASSEXW wc = { sizeof(wc), CS_OWNDC, WndProc, 0L, 0L, GetModuleHandle(nullptr), nullptr, nullptr, nullptr, nullptr, L"ImGui Example", nullptr };
     ::RegisterClassExW(&wc);
-    HWND hwnd = ::CreateWindowW(wc.lpszClassName, L"Dear ImGui Win32+OpenGL3 Example", WS_OVERLAPPEDWINDOW, 100, 100, 1280, 800, nullptr, nullptr, wc.hInstance, nullptr);
+    HWND hwnd = ::CreateWindowW(wc.lpszClassName, L"Dear ImGui Win32+OpenGL3 Example", WS_OVERLAPPEDWINDOW, 100, 100, (int)(1280 * main_scale), (int)(800 * main_scale), nullptr, nullptr, wc.hInstance, nullptr);
 
     // Initialize OpenGL
     if (!CreateDeviceWGL(hwnd, &g_MainWindow))
@@ -67,6 +70,11 @@ int main(int, char**)
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 
+    // Setup scaling
+    ImGuiStyle& style = ImGui::GetStyle();
+    style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+    style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+
     // Setup Platform/Renderer backends
     ImGui_ImplWin32_InitForOpenGL(hwnd);
     ImGui_ImplOpenGL3_Init();

examples/example_win32_vulkan/main.cpp

@@ -342,11 +342,14 @@ LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 // Main code
 int main(int, char**)
 {
+    // Make process DPI aware and obtain main monitor scale
+    ImGui_ImplWin32_EnableDpiAwareness();
+    float main_scale = ImGui_ImplWin32_GetDpiScaleForMonitor(::MonitorFromPoint(POINT{ 0, 0 }, MONITOR_DEFAULTTOPRIMARY));
+
     // Create application window
-    //ImGui_ImplWin32_EnableDpiAwareness();
     WNDCLASSEXW wc = { sizeof(wc), CS_CLASSDC, WndProc, 0L, 0L, GetModuleHandle(nullptr), nullptr, nullptr, nullptr, nullptr, L"ImGui Example", nullptr };
     ::RegisterClassExW(&wc);
-    HWND hwnd = ::CreateWindowW(wc.lpszClassName, L"Dear ImGui Win32+Vulkan Example", WS_OVERLAPPEDWINDOW, 100, 100, 1280, 800, nullptr, nullptr, wc.hInstance, nullptr);
+    HWND hwnd = ::CreateWindowW(wc.lpszClassName, L"Dear ImGui Win32+Vulkan Example", WS_OVERLAPPEDWINDOW, 100, 100, (int)(1280 * main_scale), (int)(800 * main_scale), nullptr, nullptr, wc.hInstance, nullptr);
 
     ImVector<const char*> extensions;
     extensions.push_back("VK_KHR_surface");
@@ -369,7 +372,7 @@ int main(int, char**)
     // Show the window
     // FIXME: Retrieve client size from window itself.
     ImGui_ImplVulkanH_Window* wd = &g_MainWindowData;
-    SetupVulkanWindow(wd, surface, 1280, 800);
+    SetupVulkanWindow(wd, surface, (int)(1280 * main_scale), (int)(800 * main_scale));
     ::ShowWindow(hwnd, SW_SHOWDEFAULT);
     ::UpdateWindow(hwnd);
 
@@ -384,6 +387,11 @@ int main(int, char**)
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // Setup scaling
+    ImGuiStyle& style = ImGui::GetStyle();
+    style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+    style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+
     // Setup Platform/Renderer backends
     ImGui_ImplWin32_Init(hwnd);
     ImGui_ImplVulkan_InitInfo init_info = {};