JS 运动框架 （1）缓冲运动

function getStyle(obj, name)
{
if(obj.currentStyle)
{
return obj.currentStyle[name];
}
else
{
return getComputedStyle(obj, false)[name];
}
}

function startMove(obj, attr, iTarget)
{
clearInterval(obj.timer);
obj.timer=setInterval(function (){
var cur=0;

if(attr=='opacity')
{
cur=Math.round(parseFloat(getStyle(obj, attr))*100);
}
else
{
cur=parseInt(getStyle(obj, attr));
}

var speed=(iTarget-cur)/6;
speed=speed>0?Math.ceil(speed):Math.floor(speed);

if(cur==iTarget)
{
clearInterval(obj.timer);
}
else
{
if(attr=='opacity')
{
obj.style.filter='alpha(opacity:'+(cur+speed)+')';
obj.style.opacity=(cur+speed)/100;

}
else
{
obj.style[attr]=cur+speed+'px';
}
}
}, 30);
}