有31中缓动算法，实现了颜色的自动转换（#f00 #ff0000 rgb(255,0,0)格式到颜色运算格式，最后返回#ff0000格式）、px单位的自动转换。
调用接口：
/**
* 对外接口
* Tween的示例
* @param startProps 开始属性，单个属性或者数组
* @param endProps 结束属性，单个属性或者数组
* @param timeSeconds 运动消耗时间，单位秒
* @param animType 动作类型，字符串型，内部自己转换算子
* @param delay 延迟时间，多长时间后开始运动，单位秒
*/
window.rtween = function(startProps, endProps, timeSeconds, animType, delay)
{
var tw = new Tween();
tw.start(startProps, endProps, timeSeconds, animType, delay);
return tw;
}
示例如下：
http://img.jb51.net/online/Tween.htm选择列表里面的缓动算法，点前面的按钮，就会以想对的缓动算法运动
源代码：
http://img.jb51.net/jslib/jquery/rtween.js核心代码:
function Tween()
{
this._frame=20;
//
this._animType = linear;
this._delay = 0;
//
this.run = function(){}
this.complete = function(){}
}
//
Tween.prototype.getValue = function(prop)
{
this._valueType = ”;
if(prop.constructor == Array) return prop;
//
if(typeof(prop) == 'string')
{
if(isColor(prop))
{
this._valueType = ‘color';
return c2a(prop);
}
if(prop.split('px').length>1)
{
this._valueType = ‘px';
return [prop.split('px')[0]];
}
}
return [prop];
}
Tween.prototype.setValue = function(prop)
{
if(this._valueType == ‘color')return a2c(prop);
if(this._valueType == ‘px')return prop[0]+'px';
return prop;
}
Tween.prototype.start = function(startProps, endProps, timeSeconds, animType, delay)
{
if(animType != undefined)this._animType = this.animTypes[animType];
if(delay != undefined)this._delay = delay;
//
this._timeSeconds = timeSeconds;
this._startTimer = new Date().getTime() + this._delay * 1000;
//
this._endProps = this.getValue(endProps);
this._startProps = this.getValue(startProps);
this._currentProps = [];
//
var $this = this;
clearInterval(this._runID);
this._runID = setInterval(
function(){$this._run();}
,this._frame);
}
Tween.prototype.stop = function(state)
{
for(var i in this._startProps)
{
if(Number(state)>0)
this._currentProps[i] = this._endProps[i];
else if(Number(state)<0)
this._currentProps[i] = this._startProps[i];
}
this.callListener();
this.complete();
//
clearInterval(this._runID);
}
Tween.prototype.callListener = function()
{
this.run(this.setValue(this._currentProps));
}
Tween.prototype._run = function()
{
if ( new Date().getTime()- this._startTimer< 0) return;
var isEnd = false;
//
for(var i in this._startProps)
{
this._currentProps[i] = this._animType( new Date().getTime()-this._startTimer,Number(this._startProps[i]),Number(this._endProps[i])-Number(this._startProps[i]),this._timeSeconds * 1000);
//
if(this._startTimer + (this._timeSeconds * 1000) <= new Date().getTime())
{
this._currentProps[i] = this._endProps[i];
isEnd = true;
}
}
//
if(isEnd)this.stop();
else this.callListener();
}
