freeglut_return_if_fail( fgStructure.GameMode );
fgStructure.GameMode->State.IsGameMode = GL_FALSE;
fgAddToWindowDestroyList( fgStructure.GameMode );
freeglut_return_if_fail( fgStructure.GameMode );
fgStructure.GameMode->State.IsGameMode = GL_FALSE;
fgAddToWindowDestroyList( fgStructure.GameMode );