Hard question.

 	MSG msg;
	::ZeroMemory(&msg, sizeof(MSG));

	static float lastTime = (float)timeGetTime(); 

	while(msg.message != WM_QUIT)
	{
		if(::PeekMessage(&msg, 0, 0, 0, PM_REMOVE))
		{
			::TranslateMessage(&msg);
			::DispatchMessage(&msg);
		}
		else
        {	
		float currTime  = (float)timeGetTime();
			float timeDelta = (currTime - lastTime)*0.001f;
			
			if (timeDelta>.02)
			{ptr_display(timeDelta);
			lastTime = currTime;} 
        }
    }
    return msg.wParam;
}