import { TEasingFunction } from '../types';

export const EaseInOutBack: TEasingFunction = (x) => {
  const c1 = 1.70158;
  const c2 = c1 * 1.525;

  return x < 0.5
    ? ((2 * x) ** 2 * ((c2 + 1) * 2 * x - c2)) / 2
    : ((2 * x - 2) ** 2 * ((c2 + 1) * (x * 2 - 2) + c2) + 2) / 2;
};