jq中animate其他运动形式的扩展

jq运动同样是基于tween的。
jq中只有linear和swing两种运动形式，可以通过$.extend(）把tween中的运动扩展到jq中。

<script src="http://code.jquery.com/jquery-1.11.0.min.js">script>
<script>
$.extend(jQuery.easing , {

    easeIn: function(x,t, b, c, d){  //加速曲线
        return c*(t/=d)*t + b;
    },
    easeOut: function(x,t, b, c, d){  //减速曲线
        return -c *(t/=d)*(t-2) + b;
    },
    easeBoth: function(x,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(x,t, b, c, d){  //加加速曲线
        return c*(t/=d)*t*t*t + b;
    },
    easeOutStrong: function(x,t, b, c, d){  //减减速曲线
        return -c * ((t=t/d-1)*t*t*t - 1) + b;
    },
    easeBothStrong: function(x,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(x,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(x,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(x,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(x,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(x,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(x,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(x,t, b, c, d){    //弹球减振（弹球渐出）
        return c - this['bounceOut'](x,d-t, 0, c, d) + b;
    },       
    bounceOut: function(x,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(x,t, b, c, d){
        if (t < d/2) {
            return this['bounceIn'](x,t*2, 0, c, d) * 0.5 + b;
        }
        return this['bounceOut'](x,t*2-d, 0, c, d) * 0.5 + c*0.5 + b;
    }

});

script>

实例应用：

$(function(){

    $('#div1').click(function(){

        $(this).animate({width : 300 , height : 300},4000,'elasticOut');

    });

});