easings.js

export default {
  // 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 < 0.5 ? 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 < 0.5 ? 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 < 0.5 ? 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 < 0.5 ? 16 * t * t * t * t * t : 1 + 16 * (--t) * t * t * t * t }
}