缓存布局信息

;(function(global){
        var wind = document.getElementById("wind"), count = 0;

        function marque(){
            console.log("wind.offsetTop:",wind.offsetTop,"wind.offsetLeft::",wind.offsetLeft);


            /*wind.style.left = 12 + wind.offsetLeft + "px";
            wind.style.top = 1 + wind.offsetTop + "px";
            console.log("wind.offsetTop:",wind.offsetTop,"wind.offsetLeft::",wind.offsetLeft);*/

            // 上面会不停得计算 offsetLeft offsetTop ，不停得查询，导致浏览器刷新渲染而不利于优化
            // 就是 缓存布局信息啦
            count++;
            wind.style.top = count + "px";
            wind.style.left = count + "px";

            if(wind.offsetTop >= 200){
                //stopAnimation();
                console.log(111)
                
                clearInterval(timer);
            }
        }

        timer = setInterval(marque,20);
        console.log(wind.offsetTop)
        
    })(this)