Backends: GLFW: added ImGui_ImplGlfw_GetContentScaleForMonitor(), ImGui_ImplGlfw_GetContentScaleForWindow() helpers.

# Conflicts:
#	backends/imgui_impl_glfw.cpp

backends/imgui_impl_glfw.cpp

@@ -28,6 +28,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-06-11: Added ImGui_ImplGlfw_GetContentScaleForWindow(GLFWwindow* window) and ImGui_ImplGlfw_GetContentScaleForMonitor(GLFWmonitor* monitor) helper to facilitate making DPI-aware apps.
 //  2025-03-10: Map GLFW_KEY_WORLD_1 and GLFW_KEY_WORLD_2 into ImGuiKey_Oem102.
 //  2025-03-03: Fixed clipboard handler assertion when using GLFW <= 3.2.1 compiled with asserts enabled.
 //  2024-08-22: Moved some OS/backend related function pointers from ImGuiIO to ImGuiPlatformIO:
@@ -840,6 +841,33 @@ static void ImGui_ImplGlfw_UpdateGamepads()
     #undef MAP_ANALOG
 }
 
+// - On Windows the process needs to be marked DPI-aware!! SDL2 doesn't do it by default. You can call ::SetProcessDPIAware() or call ImGui_ImplWin32_EnableDpiAwareness() from Win32 backend.
+// - Apple platforms use FramebufferScale so we always return 1.0f.
+// - Some accessibility applications are declaring virtual monitors with a DPI of 0.0f, see #7902. We preserve this value for caller to handle.
+float ImGui_ImplGlfw_GetContentScaleForWindow(GLFWwindow* window)
+{
+#if GLFW_HAS_PER_MONITOR_DPI && !defined(__APPLE__)
+    float x_scale, y_scale;
+    glfwGetWindowContentScale(window, &x_scale, &y_scale);
+    return x_scale;
+#else
+    IM_UNUSED(window);
+    return 1.0f;
+#endif
+}
+
+float ImGui_ImplGlfw_GetContentScaleForMonitor(GLFWmonitor* monitor)
+{
+#if GLFW_HAS_PER_MONITOR_DPI && !defined(__APPLE__)
+    float x_scale, y_scale;
+    glfwGetMonitorContentScale(monitor, &x_scale, &y_scale);
+    return x_scale;
+#else
+    IM_UNUSED(monitor);
+    return 1.0f;
+#endif
+}
+
 void ImGui_ImplGlfw_NewFrame()
 {
     ImGuiIO& io = ImGui::GetIO();

backends/imgui_impl_glfw.h

@@ -62,5 +62,8 @@ IMGUI_IMPL_API void     ImGui_ImplGlfw_MonitorCallback(GLFWmonitor* monitor, int
 
 // GLFW helpers
 IMGUI_IMPL_API void     ImGui_ImplGlfw_Sleep(int milliseconds);
+IMGUI_IMPL_API float    ImGui_ImplGlfw_GetContentScaleForWindow(GLFWwindow* window);
+IMGUI_IMPL_API float    ImGui_ImplGlfw_GetContentScaleForMonitor(GLFWmonitor* monitor);
+
 
 #endif // #ifndef IMGUI_DISABLE