tweenkle/es/easing/Back.js

Lightweight tweening library for all your tweening and animation needs.

export var In = function In(time, beginningValue, changeValue, duration) {
  var s = 1.70158;
  return changeValue * (time /= duration) * time * ((s + 1) * time - s) + beginningValue;
};
export var Out = function Out(time, beginningValue, changeValue, duration) {
  var s = 1.70158;
  return changeValue * ((time = time / duration - 1) * time * ((s + 1) * time + s) + 1) + beginningValue;
};
export var InOut = function InOut(time, beginningValue, changeValue, duration) {
  var s = 1.70158;

  if ((time /= duration / 2) < 1) {
    return changeValue / 2 * (time * time * (((s *= 1.525) + 1) * time - s)) + beginningValue;
  }

  return changeValue / 2 * ((time -= 2) * time * (((s *= 1.525) + 1) * time + s) + 2) + beginningValue;
};
export default {
  In: In,
  Out: Out,
  InOut: InOut
};