Backends: GLFW: Disable multi-viewports under Wayland. (#8587)

backends/imgui_impl_glfw.cpp

@@ -31,6 +31,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-04-26: Disable multi-viewports under Wayland. (#8587)
 //  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.
 //  2025-02-21: [Docking] Update monitors and work areas information every frame, as the later may change regardless of monitor changes. (#8415)
@@ -162,6 +163,7 @@
 #define GLFW_HAS_GAMEPAD_API            (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwGetGamepadState() new api
 #define GLFW_HAS_GETKEYNAME             (GLFW_VERSION_COMBINED >= 3200) // 3.2+ glfwGetKeyName()
 #define GLFW_HAS_GETERROR               (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwGetError()
+#define GLFW_HAS_GETPLATFORM            (GLFW_VERSION_COMBINED >= 3400) // 3.4+ glfwGetPlatform()
 
 // GLFW data
 enum GlfwClientApi
@@ -622,8 +624,16 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     io.BackendPlatformName = "imgui_impl_glfw";
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+
+    bool has_viewports = false;
 #ifndef __EMSCRIPTEN__
-    io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;    // We can create multi-viewports on the Platform side (optional)
+    has_viewports = true;
+#if GLFW_HAS_GETPLATFORM
+    if (glfwGetPlatform() == GLFW_PLATFORM_WAYLAND)
+        has_viewports = false;
+#endif
+    if (has_viewports)
+        io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;  // We can create multi-viewports on the Platform side (optional)
 #endif
 #if GLFW_HAS_MOUSE_PASSTHROUGH || GLFW_HAS_WINDOW_HOVERED
     io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
@@ -690,7 +700,8 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
 #else
     IM_UNUSED(main_viewport);
 #endif
-    ImGui_ImplGlfw_InitMultiViewportSupport();
+    if (has_viewports)
+        ImGui_ImplGlfw_InitMultiViewportSupport();
 
     // Windows: register a WndProc hook so we can intercept some messages.
 #ifdef _WIN32

backends/imgui_impl_sdl2.cpp

@@ -561,7 +561,6 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
     if (bd->MouseCanUseGlobalState)
         io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;  // We can create multi-viewports on the Platform side (optional)
 
-
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     platform_io.Platform_SetClipboardTextFn = ImGui_ImplSDL2_SetClipboardText;
     platform_io.Platform_GetClipboardTextFn = ImGui_ImplSDL2_GetClipboardText;

docs/CHANGELOG.txt

@@ -125,6 +125,7 @@ Docking+Viewports Branch:
 - Backends: SDL2, SDL3: revert updating monitors and work areas info every
   frame. Only do it on Windows to detect task-bar resize until we get an
   adequate event for it. (#8415, #8558)
+- Backends: GLFW: Disable multi-viewports under Wayland (require GLFW 3.4). (#8587)
 
 
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