/*
 * Easing Functions - inspired from http://gizma.com/easing/
 * only considering the x value for the range [0, 1] => [0, 1]
 */
EasingFunctions = {
  // no easing, no acceleration
  linear: function (x) { return x },
  // accelerating from zero velocity
  easeInQuad: function (x) { return x*x },
  // decelerating to zero velocity
  easeOutQuad: function (x) { return x*(2-x) },
  // acceleration until halfway, then deceleration
  easeInOutQuad: function (x) { return x<.5 ? 2*x*x : -1+(4-2*x)*x },
  // accelerating from zero velocity 
  easeInCubic: function (x) { return x*x*x },
  // decelerating to zero velocity 
  easeOutCubic: function (x) { return (--x)*x*x+1 },
  // acceleration until halfway, then deceleration 
  easeInOutCubic: function (x) { return x<.5 ? 4*x*x*x : (x-1)*(2*x-2)*(2*x-2)+1 },
  // accelerating from zero velocity 
  easeInQuart: function (x) { return x*x*x*x },
  // decelerating to zero velocity 
  easeOutQuart: function (x) { return 1-(--x)*x*x*x },
  // acceleration until halfway, then deceleration
  easeInOutQuart: function (x) { return x<.5 ? 8*x*x*x*x : 1-8*(--x)*x*x*x },
  // accelerating from zero velocity
  easeInQuint: function (x) { return x*x*x*x*x },
  // decelerating to zero velocity
  easeOutQuint: function (x) { return 1+(--x)*x*x*x*x },
  // acceleration until halfway, then deceleration 
  easeInOutQuint: function (x) { return x<.5 ? 16*x*x*x*x*x : 1+16*(--x)*x*x*x*x }
}