Easing functions

easing-functions.js

// This stuff was obtained from somewhere..the source has been lost
const EasingFunctions = {
  // no easing, no acceleration
  linear: function (t) { return t },
  // accelerating from zero velocity
  easeInQuad: function (t) { return t * t },
  // decelerating to zero velocity
  easeOutQuad: function (t) { return t * (2 - t) },
  // acceleration until halfway, then deceleration
  easeInOutQuad: function (t) { return t < 0.5 ? 2 * t * t : -1 + (4 - 2 * t) * t },
  // accelerating from zero velocity
  easeInCubic: function (t) { return t * t * t },
  // decelerating to zero velocity
  easeOutCubic: function (t) { return (--t) * t * t + 1 },
  // acceleration until halfway, then deceleration
  easeInOutCubic: function (t) { return t < 0.5 ? 4 * t * t * t : (t - 1) * (2 * t - 2) * (2 * t - 2) + 1 },
  // accelerating from zero velocity
  easeInQuart: function (t) { return t * t * t * t },
  // decelerating to zero velocity
  easeOutQuart: function (t) { return 1 - (--t) * t * t * t },
  // acceleration until halfway, then deceleration
  easeInOutQuart: function (t) { return t < 0.5 ? 8 * t * t * t * t : 1 - 8 * (--t) * t * t * t },
  // accelerating from zero velocity
  easeInQuint: function (t) { return t * t * t * t * t },
  // decelerating to zero velocity
  easeOutQuint: function (t) { return 1 + (--t) * t * t * t * t },
  // acceleration until halfway, then deceleration
  easeInOutQuint: function (t) { return t < 0.5 ? 16 * t * t * t * t * t : 1 + 16 * (--t) * t * t * t * t }
}

export default EasingFunctions