问下这句话是干什么用的啊？

zhuzhusex201409 2014-12-14 05:08:40

下面是一个common.js文件中的代码，请问是干什么用的啊？我怎么看不懂啊？

jQuery.easing['jswing'] = jQuery.easing['swing'];
jQuery.extend(jQuery.easing, {
def: 'easeOutQuad',
swing: function (x, t, b, c, d) {
return jQuery.easing[jQuery.easing.def](x, t, b, c, d)
},
easeInQuad: function (x, t, b, c, d) {
return c * (t /= d) * t + b
},
easeOutQuad: function (x, t, b, c, d) {
return -c * (t /= d) * (t - 2) + b
},
easeInOutQuad: function (x, t, b, c, d) {
if ((t /= d / 2) < 1) return c / 2 * t * t + b;
return -c / 2 * ((--t) * (t - 2) - 1) + b
},
easeInCubic: function (x, t, b, c, d) {
return c * (t /= d) * t * t + b
},
easeOutCubic: function (x, t, b, c, d) {
return c * ((t = t / d - 1) * t * t + 1) + b
},
easeInOutCubic: function (x, t, b, c, d) {
if ((t /= d / 2) < 1) return c / 2 * t * t * t + b;
return c / 2 * ((t -= 2) * t * t + 2) + b
},
easeInQuart: function (x, t, b, c, d) {
return c * (t /= d) * t * t * t + b
},
easeOutQuart: function (x, t, b, c, d) {
return -c * ((t = t / d - 1) * t * t * t - 1) + b
},
easeInOutQuart: function (x, t, b, c, d) {
if ((t /= d / 2) < 1) return c / 2 * t * t * t * t + b;
return -c / 2 * ((t -= 2) * t * t * t - 2) + b
},
easeInQuint: function (x, t, b, c, d) {
return c * (t /= d) * t * t * t * t + b
},
easeOutQuint: function (x, t, b, c, d) {
return c * ((t = t / d - 1) * t * t * t * t + 1) + b
},
easeInOutQuint: function (x, t, b, c, d) {
if ((t /= d / 2) < 1) return c / 2 * t * t * t * t * t + b;
return c / 2 * ((t -= 2) * t * t * t * t + 2) + b
},
easeInSine: function (x, t, b, c, d) {
return -c * Math.cos(t / d * (Math.PI / 2)) + c + b
},
easeOutSine: function (x, t, b, c, d) {
return c * Math.sin(t / d * (Math.PI / 2)) + b
},
easeInOutSine: function (x, t, b, c, d) {
return -c / 2 * (Math.cos(Math.PI * t / d) - 1) + b
},
easeInExpo: function (x, t, b, c, d) {
return (t == 0) ? b : c * Math.pow(2, 10 * (t / d - 1)) + b
},
easeOutExpo: function (x, t, b, c, d) {
return (t == d) ? b + c : c * (-Math.pow(2, -10 * t / d) + 1) + b
},
easeInOutExpo: function (x, t, b, c, d) {
if (t == 0) return b;
if (t == d) return b + c;
if ((t /= d / 2) < 1) return c / 2 * Math.pow(2, 10 * (t - 1)) + b;
return c / 2 * (-Math.pow(2, -10 * --t) + 2) + b
},
easeInCirc: function (x, t, b, c, d) {
return -c * (Math.sqrt(1 - (t /= d) * t) - 1) + b
},
easeOutCirc: function (x, t, b, c, d) {
return c * Math.sqrt(1 - (t = t / d - 1) * t) + b
},
easeInOutCirc: function (x, t, b, c, d) {
if ((t /= d / 2) < 1) return -c / 2 * (Math.sqrt(1 - t * t) - 1) + b;
return c / 2 * (Math.sqrt(1 - (t -= 2) * t) + 1) + b
},
easeInElastic: function (x, t, b, c, d) {
var s = 1.70158;
var p = 0;
var a = c;
if (t == 0) return b;
if ((t /= d) == 1) return b + c;
if (!p) p = d * .3;
if (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
},
easeOutElastic: function (x, t, b, c, d) {
var s = 1.70158;
var p = 0;
var a = c;
if (t == 0) return b;
if ((t /= d) == 1) return b + c;
if (!p) p = d * .3;
if (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
},
easeInOutElastic: function (x, t, b, c, d) {
var s = 1.70158;
var p = 0;
var a = c;
if (t == 0) return b;
if ((t /= d / 2) == 2) return b + c;
if (!p) p = d * (.3 * 1.5);
if (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 -.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) * .5 + c + b
},
easeInBack: function (x, t, b, c, d, s) {
if (s == undefined) s = 1.70158;
return c * (t /= d) * t * ((s + 1) * t - s) + b
},
easeOutBack: function (x, t, b, c, d, s) {
if (s == undefined) s = 1.70158;
return c * ((t = t / d - 1) * t * ((s + 1) * t + s) + 1) + b
},
easeInOutBack: function (x, t, b, c, d, s) {
if (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
},
easeInBounce: function (x, t, b, c, d) {
return c - jQuery.easing.easeOutBounce(x, d - t, 0, c, d) + b
},
easeOutBounce: 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 + .75) + b
} else if (t < (2.5 / 2.75)) {
return c * (7.5625 * (t -= (2.25 / 2.75)) * t + .9375) + b
} else {
return c * (7.5625 * (t -= (2.625 / 2.75)) * t + .984375) + b
}
},
easeInOutBounce: function (x, t, b, c, d) {
if (t < d / 2) return jQuery.easing.easeInBounce(x, t * 2, 0, c, d) * .5 + b;
return jQuery.easing.easeOutBounce(x, t * 2 - d, 0, c, d) * .5 + c * .5 + b
}
});

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