var Tween = {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;}
}