easing.eq.js

// https://gist.github.com/gre/1650294
/*
 * Found HERE: https://codepen.io/xerxesnoble/pen/JNgmJR
 * Easing Functions - inspired from http://gizma.com/easing/
 * only considering the t value for the range [0, 1] => [0, 1]
 */
const ease = {
  // no easing, no acceleration
  linear: function (t) { return t },
  // accelerating from zero velocity
  InQuad: function (t) { return t*t },
  // decelerating to zero velocity
  OutQuad: function (t) { return t*(2-t) },
  // acceleration until halfway, then deceleration
  InOutQuad: function (t) { return t<.5 ? 2*t*t : -1+(4-2*t)*t },
  // accelerating from zero velocity 
  InCubic: function (t) { return t*t*t },
  // decelerating to zero velocity 
  OutCubic: function (t) { return (--t)*t*t+1 },
  // acceleration until halfway, then deceleration 
  InOutCubic: function (t) { return t<.5 ? 4*t*t*t : (t-1)*(2*t-2)*(2*t-2)+1 },
  // accelerating from zero velocity 
  InQuart: function (t) { return t*t*t*t },
  // decelerating to zero velocity 
  OutQuart: function (t) { return 1-(--t)*t*t*t },
  // acceleration until halfway, then deceleration
  InOutQuart: function (t) { return t<.5 ? 8*t*t*t*t : 1-8*(--t)*t*t*t },
  // accelerating from zero velocity
  InQuint: function (t) { return t*t*t*t*t },
  // decelerating to zero velocity
  OutQuint: function (t) { return 1+(--t)*t*t*t*t },
  // acceleration until halfway, then deceleration 
  InOutQuint: function (t) { return t<.5 ? 16*t*t*t*t*t : 1+16*(--t)*t*t*t*t },
  // elastic bounce effect at the beginning
  InElastic: function (t) { return (.04 - .04 / t) * Math.sin(25 * t) + 1 },
  // elastic bounce effect at the end
  OutElastic: function (t) { return .04 * t / (--t) * Math.sin(25 * t) },
  // elastic bounce effect at the beginning and end
  InOutElastic: function (t) { return (t -= .5) < 0 ? (.01 + .01 / t) * Math.sin(50 * t) : (.02 - .01 / t) * Math.sin(50 * t) + 1 }
}