REVIEWED: Fullscreen modes on Linux (X11 over XWayland)

It does not work as expected... :(

src/platforms/rcore_desktop_glfw.c

@@ -196,11 +196,16 @@ void ToggleFullscreen(void)
             CORE.Window.display.height = mode->height;
 
             CORE.Window.position = (Point){ 0, 0 };
-            CORE.Window.screen = p">(Size){ CORE.Window.display.width, CORE.Window.display.height };
+            CORE.Window.screen = CORE.Window.display;
 
             // Set fullscreen flag to be processed on FramebufferSizeCallback() accordingly
             FLAG_SET(CORE.Window.flags, FLAG_FULLSCREEN_MODE);
 
+            // NOTE: X11 requires undecorating the window before switching to
+            // fullscreen to avoid issues with framebuffer scaling
+            glfwSetWindowAttrib(platform.handle, GLFW_DECORATED, GLFW_FALSE);
+            FLAG_SET(CORE.Window.flags, FLAG_WINDOW_UNDECORATED);
+
             // WARNING: This function launches FramebufferSizeCallback()
             glfwSetWindowMonitor(platform.handle, monitor, 0, 0, CORE.Window.screen.width, CORE.Window.screen.height, GLFW_DONT_CARE);
         }
@@ -226,8 +231,14 @@ void ToggleFullscreen(void)
         }
 #endif
 
+        // WARNING: This function launches FramebufferSizeCallback()
         glfwSetWindowMonitor(platform.handle, NULL, CORE.Window.position.x, CORE.Window.position.y, 
             CORE.Window.screen.width, CORE.Window.screen.height, GLFW_DONT_CARE);
+
+        // NOTE: X11 requires restoring the decorated window after switching from
+        // fullscreen to avoid issues with framebuffer scaling
+        glfwSetWindowAttrib(platform.handle, GLFW_DECORATED, GLFW_TRUE);
+        FLAG_CLEAR(CORE.Window.flags, FLAG_WINDOW_UNDECORATED);
     }
 
     // Try to enable GPU V-Sync, so frames are limited to screen refresh rate (60Hz -> 60 FPS)