js 网上见到的动画函数 备份

<script>

function startMove(obj,json,fn){
	clearInterval(obj.timer);
	obj.timer = setInterval(function(){

		var bBtn = true;

		for(var attr in json){

			var iCur = 0;
			if(attr == 'opacity'){
				iCur = Math.round(getStyle(obj,attr)*100);
			}
			else{
				iCur = parseInt(getStyle(obj,attr));
			}

			var iSpeed = (json[attr] - iCur)/5;
			iSpeed = iSpeed > 0 ? Math.ceil(iSpeed) : Math.floor(iSpeed);

			if(iCur != json[attr]){

				bBtn = false;
			}

			if(attr == 'opacity'){
				obj.style.filter = 'alpha(opacity='+(iCur+iSpeed)+')';
				obj.style.opacity = (iCur + iSpeed)/100;
			}
			else{
				obj.style[attr] = iCur + iSpeed + 'px';
			}
		}

		if(bBtn){
			clearInterval(obj.timer);
			fn && fn.call(obj);
		}
	},30);
}

function getStyle(obj,attr){
	return obj.currentStyle?obj.currentStyle[attr]:getComputedStyle(obj,250)[attr];
}

function startMove2(obj,json,times,fx,fn){

	if( typeof times == 'undefined' ){
		times = 400;
		fx = 'linear';
	}

	if( typeof times == 'string' ){
		if(typeof fx == 'function'){
			fn = fx;
		}
		fx = times;
		times = 400;
	}
	else if(typeof times == 'function'){
		fn = times;
		times = 400;
		fx = 'linear';
	}
	else if(typeof times == 'number'){
		if(typeof fx == 'function'){
			fn = fx;
			fx = 'linear';
		}
		else if(typeof fx == 'undefined'){
			fx = 'linear';
		}
	}

	var iCur = {};

	for(var attr in json){
		iCur[attr] = 0;

		if( attr == 'opacity' ){
			if(Math.round(getStyle(obj,attr)*100) == 0){
				iCur[attr] = 0;
			}
			else{
				iCur[attr] = Math.round(getStyle(obj,attr)*100) || 100;
			}
		}
		else{
			iCur[attr] = parseInt(getStyle(obj,attr)) || 0;
		}

	}

	var startTime = now();

	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 value = Tween[fx](scale*times, iCur[attr] , json[attr] - iCur[attr] , 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);

	function now(){
		return (new Date()).getTime();
	}

}

var Tween = {
	linear: function (t, b, c, d){  //鍖€閫�
		return c*t/d + b;
	},
	easeIn: function(t, b, c, d){  //鍔犻€熸洸绾�
		return c*(t/=d)*t + b;
	},
	easeOut: function(t, b, c, d){  //鍑忛€熸洸绾�
		return -c *(t/=d)*(t-2) + b;
	},
	easeBoth: function(t, b, c, d){  //鍔犻€熷噺閫熸洸绾�
		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){  //鍔犲姞閫熸洸绾�
		return c*(t/=d)*t*t*t + b;
	},
	easeOutStrong: function(t, b, c, d){  //鍑忓噺閫熸洸绾�
		return -c * ((t=t/d-1)*t*t*t - 1) + b;
	},
	easeBothStrong: function(t, b, c, d){  //鍔犲姞閫熷噺鍑忛€熸洸绾�
		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){  //姝ｅ鸡琛板噺鏇茬嚎锛堝脊鍔ㄦ笎鍏ワ級
		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){    //姝ｅ鸡澧炲己鏇茬嚎锛堝脊鍔ㄦ笎鍑猴級
		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){     //鍥為€€鍔犻€燂紙鍥為€€娓愬叆锛�
		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;  //鍥炵缉鐨勮窛绂�
		}
		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){    //寮圭悆鍑忔尟锛堝脊鐞冩笎鍑猴級
		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;
	}
}
</script>