GraphicsWindow: reset screen mode before destroying window

This will prevent a display flicker upon exit of the game. The display's mode should be reset by the time the graphics window has been destroyed.

src/archutils/Win32/GraphicsWindow.cpp

@@ -436,6 +436,12 @@ void GraphicsWindow::CreateGraphicsWindow( const VideoModeParams &p, bool bForce
 /** @brief Shut down the window, but don't reset the video mode. */
 void GraphicsWindow::DestroyGraphicsWindow()
 {
+	// If we were in fullscreen, release the display mode before destroying the window
+	if( g_hWndMain && !g_CurrentParams.windowed )
+	{
+		ChangeDisplaySettingsEx(g_CurrentParams.sDisplayId, nullptr, nullptr, 0, nullptr);
+	}
+	
 	if( g_HDC != nullptr )
 	{
 		ReleaseDC( g_hWndMain, g_HDC );
@@ -526,12 +532,6 @@ void GraphicsWindow::Shutdown()
 {
 	DestroyGraphicsWindow();
 
-	/* Return to the desktop resolution, if needed.
-	 * It'd be nice to not do this: Windows will do it when we quit, and if
-	 * we're shutting down OpenGL to try D3D, this will cause extra mode
-	 * switches. However, we need to do this before displaying dialogs. */
-	ChangeDisplaySettingsEx( g_CurrentParams.sDisplayId.c_str(), nullptr, nullptr, 0, nullptr );
-
 	AppInstance inst;
 	UnregisterClass( g_sClassName.c_str(), inst );
 }