js-运动框架（时间版）

//obj:运动对象，json：运动属性json格式，times：运动时间（不能大于间隔时间），fx：运动形式，fn：回掉函数

function  startMove(obj,json,times,fx,fn){
var startTime=now();
var iCur={};
for(var attr in json){

iCur[attr]=0;
if(attr=="opacity"){

iCur[attr]=Math.round(getStyle(obj,attr)*100);
}else{

iCur[attr]=parseInt(getStyle(obj,attr));
}

}
clearInterval(obj.timer);
obj.timer=setInterval(function(){
var changeTime=now();

var scale = 1 -  Math.max(0,startTime  -  changeTime + times)/times ;

for(var attr in json ){

var cvalue=parseInt(json[attr])-iCur[attr];
console.log(cvalue);

var value=Tween[fx](scale*times,iCur[attr],cvalue,times);

if(attr=="opacity"){

obj.style.filter="alpha(opacity="+value+")";
obj.style.opacity=value/100;

}else{

obj.style[attr]=value+"px";

}

}
if(scale == 1){
clearInterval(obj.timer);
if(fn){
fn.call(obj);
}
}

},13);

//取得当前时间
function now(){
return (new Date()).getTime();
}

//获得样式值
function getStyle(obj,sty){
if(obj.currentStyle){

return obj.currentStyle[sty];

}else{

return window.getComputedStyle(obj,false)[sty];

}

}

//运动公式
var Tween = {

//t : 当前时间   b : 初始值  c : 变化值   d : 总时间
//return : 当前的位置

linear: function (t, b, c, d){  //匀速
return c*t/d + b;
},
easeIn: function(t, b, c, d){  //加速曲线
return c*(t/=d)*t + b;
},
easeOut: function(t, b, c, d){  //减速曲线
return -c *(t/=d)*(t-2) + b;
},
easeBoth: function(t, b, c, d){  //加速减速曲线
if ((t/=d/2) < 1) {
return c/2*t*t + b;
}
return -c/2 * ((--t)*(t-2) - 1) + b;
},
easeInStrong: function(t, b, c, d){  //加加速曲线
return c*(t/=d)*t*t*t + b;
},
easeOutStrong: function(t, b, c, d){  //减减速曲线
return -c * ((t=t/d-1)*t*t*t - 1) + b;
},
easeBothStrong: function(t, b, c, d){  //加加速减减速曲线
if ((t/=d/2) < 1) {
return c/2*t*t*t*t + b;
}
return -c/2 * ((t-=2)*t*t*t - 2) + b;
},
elasticIn: function(t, b, c, d, a, p){  //正弦衰减曲线（弹动渐入）
if (t === 0) {
return b;
}
if ( (t /= d) == 1 ) {
return b+c;
}
if (!p) {
p=d*0.3;
}
if (!a || a < Math.abs(c)) {
a = c;
var s = p/4;
} else {
var s = p/(2*Math.PI) * Math.asin (c/a);
}
return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
},
elasticOut: function(t, b, c, d, a, p){    //正弦增强曲线（弹动渐出）
if (t === 0) {
return b;
}
if ( (t /= d) == 1 ) {
return b+c;
}
if (!p) {
p=d*0.3;
}
if (!a || a < Math.abs(c)) {
a = c;
var s = p / 4;
} else {
var s = p/(2*Math.PI) * Math.asin (c/a);
}
return a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p ) + c + b;
},
elasticBoth: function(t, b, c, d, a, p){
if (t === 0) {
return b;
}
if ( (t /= d/2) == 2 ) {
return b+c;
}
if (!p) {
p = d*(0.3*1.5);
}
if ( !a || a < Math.abs(c) ) {
a = c;
var s = p/4;
}
else {
var s = p/(2*Math.PI) * Math.asin (c/a);
}
if (t < 1) {
return - 0.5*(a*Math.pow(2,10*(t-=1)) *
Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
}
return a*Math.pow(2,-10*(t-=1)) *
Math.sin( (t*d-s)*(2*Math.PI)/p )*0.5 + c + b;
},
backIn: function(t, b, c, d, s){     //回退加速（回退渐入）
if (typeof s == 'undefined') {
s = 1.70158;
}
return c*(t/=d)*t*((s+1)*t - s) + b;
},
backOut: function(t, b, c, d, s){
if (typeof s == 'undefined') {
s = 3.70158;  //回缩的距离
}
return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b;
},
backBoth: function(t, b, c, d, s){
if (typeof s == 'undefined') {
s = 1.70158;
}
if ((t /= d/2 ) < 1) {
return c/2*(t*t*(((s*=(1.525))+1)*t - s)) + b;
}
return c/2*((t-=2)*t*(((s*=(1.525))+1)*t + s) + 2) + b;
},
bounceIn: function(t, b, c, d){    //弹球减振（弹球渐出）
return c - Tween['bounceOut'](d-t, 0, c, d) + b;
},
bounceOut: function(t, b, c, d){
if ((t/=d) < (1/2.75)) {
return c*(7.5625*t*t) + b;
} else if (t < (2/2.75)) {
return c*(7.5625*(t-=(1.5/2.75))*t + 0.75) + b;
} else if (t < (2.5/2.75)) {
return c*(7.5625*(t-=(2.25/2.75))*t + 0.9375) + b;
}
return c*(7.5625*(t-=(2.625/2.75))*t + 0.984375) + b;
},
bounceBoth: function(t, b, c, d){
if (t < d/2) {
return Tween['bounceIn'](t*2, 0, c, d) * 0.5 + b;
}
return Tween['bounceOut'](t*2-d, 0, c, d) * 0.5 + c*0.5 + b;
}
}

}