Simple Easing Functions in Javascript - see https://github.com/gre/bezier-easing

easing.js

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