One argument easing equations

easings.js

/* 
  A full list of simple easing equations inspired by GIST from greweb - https://gist.github.com/gre/1650294
  Equations source - http://gsgd.co.uk/sandbox/jquery/easing/
*/

{
  linear: function(t) {
    return t
  },
  inQuad: function(t) {
    return t * t
  },
  outQuad: function(t) {
    return t * (2 - t)
  },
  inOutQuad: function(t) {
    return t < .5 ? 2 * t * t : -1 + (4 - 2 * t) * t
  },
  inCubic: function(t) {
    return t * t * t
  },
  outCubic: function(t) {
    return (--t) * t * t + 1
  },
  inOutCubic: function(t) {
    return t < .5 ? 4 * t * t * t : (t - 1) * (2 * t - 2) * (2 * t - 2) + 1
  },
  inQuart: function(t) {
    return t * t * t * t
  },
  outQuart: function(t) {
    return 1 - (--t) * t * t * t
  },
  inOutQuart: function(t) {
    return t < .5 ? 8 * t * t * t * t : 1 - 8 * (--t) * t * t * t
  },
  inQuint: function(t) {
    return t * t * t * t * t
  },
  outQuint: function(t) {
    return 1 + (--t) * t * t * t * t
  },
  inOutQuint: function(t) {
    return t < .5 ? 16 * t * t * t * t * t : 1 + 16 * (--t) * t * t * t * t
  },
  inSine: function(t) {
    return -1 * Math.cos(t / 1 * (Math.PI * 0.5)) + 1;
  },
  outSine: function(t) {
    return Math.sin(t / 1 * (Math.PI * 0.5));
  },
  inOutSine: function(t) {
    return -1 / 2 * (Math.cos(Math.PI * t) - 1);
  },
  inExpo: function(t) {
    return (t == 0) ? 0 : Math.pow(2, 10 * (t - 1));
  },
  outExpo: function(t) {
    return (t == 1) ? 1 : (-Math.pow(2, -10 * t) + 1);
  },
  inOutExpo: function(t) {
    if (t == 0) return 0;
    if (t == 1) return 1;
    if ((t /= 1 / 2) < 1) return 1 / 2 * Math.pow(2, 10 * (t - 1));
    return 1 / 2 * (-Math.pow(2, -10 * --t) + 2);
  },
  inCirc: function(t) {
    return -1 * (Math.sqrt(1 - t * t) - 1);
  },
  outCirc: function(t) {
    return Math.sqrt(1 - (t = t - 1) * t);
  },
  inOutCirc: function(t) {
    if ((t /= 1 / 2) < 1) return -1 / 2 * (Math.sqrt(1 - t * t) - 1);
    return 1 / 2 * (Math.sqrt(1 - (t -= 2) * t) + 1);
  },
  inElastic: function(t) {
    var s = 1.70158;
    var p = 0;
    var a = 1;
    if (t == 0) return 0;
    if (t == 1) return 1;
    if (!p) p = 0.3;
    if (a < 1) {
      a = 1;
      var s = p / 4;
    } else var s = p / (2 * Math.PI) * Math.asin(1 / a);
    return -(a * Math.pow(2, 10 * (t -= 1)) * Math.sin((t - s) * (2 * Math.PI) / p));
  },
  outElastic: function(t) {
    var s = 1.70158;
    var p = 0;
    var a = 1;
    if (t == 0) return 0;
    if (t == 1) return 1;
    if (!p) p = 0.3;
    if (a < 1) {
      a = 1;
      var s = p / 4;
    } else var s = p / (2 * Math.PI) * Math.asin(1 / a);
    return a * Math.pow(2, -10 * t) * Math.sin((t - s) * (2 * Math.PI) / p) + 1;
  },
  inOutElastic: function(t) {
    var s = 1.70158;
    var p = 0;
    var a = 1;
    if (t == 0) return 0;
    if ((t /= 1 / 2) == 2) return 1;
    if (!p) p = (0.3 * 1.5);
    if (a < 1) {
      a = 1;
      var s = p / 4;
    } else var s = p / (2 * Math.PI) * Math.asin(1 / a);
    if (t < 1) return -.5 * (a * Math.pow(2, 10 * (t -= 1)) * Math.sin((t - s) * (2 * Math.PI) / p));
    return a * Math.pow(2, -10 * (t -= 1)) * Math.sin((t - s) * (2 * Math.PI) / p) * 0.5 + 1;
  },
  inBack: function(t, s) {
    if (s == undefined) s = 1.70158;
    return 1 * t * t * ((s + 1) * t - s);
  },
  outBack: function(t, s) {
    if (s == undefined) s = 1.70158;
    return 1 * ((t = t / 1 - 1) * t * ((s + 1) * t + s) + 1);
  },
  inOutBack: function(t, s) {
    if (s == undefined) s = 1.70158;
    if ((t /= 1 / 2) < 1) return 1 / 2 * (t * t * (((s *= (1.525)) + 1) * t - s));
    return 1 / 2 * ((t -= 2) * t * (((s *= (1.525)) + 1) * t + s) + 2);
  },
  inBounce: function(t) {
    return 1 - this.outBounce(1 - t);
  },
  outBounce: function(t) {
    if ((t /= 1) < (1 / 2.75)) {
      return (7.5625 * t * t);
    } else if (t < (2 / 2.75)) {
      return (7.5625 * (t -= (1.5 / 2.75)) * t + .75);
    } else if (t < (2.5 / 2.75)) {
      return (7.5625 * (t -= (2.25 / 2.75)) * t + .9375);
    } else {
      return (7.5625 * (t -= (2.625 / 2.75)) * t + .984375);
    }
  },
  inOutBounce: function(t) {
    if (t < 1 / 2) return this.inBounce(t * 2) * 0.5;
    return this.outBounce(t * 2 - 1) * 0.5 + 0.5;
  }

};