Class BackInOut

fr/lavache/anime/Easing.java:430–444

Back easing in/out - backtracking slightly, then reversing direction and moving to target, then overshooting target, reversing, and finally coming back to target.

     * then overshooting target, reversing, and finally coming back to target.
     */
    class BackInOut extends Back {
        public BackInOut() {
            super();
        }

        public BackInOut(float overshoot) {
            super(overshoot);
        }

        public float ease(float t, float b, float c, float d) {
            float s = getOvershoot();
            if ((t /= d / 2) < 1) return c / 2 * (t * t * (((s *= (1.525)) + 1) * t - s)) + b;
            return c / 2 * ((t -= 2) * t * (((s *= (1.525)) + 1) * t + s) + 2) + b;
        }
    }
}