ElasticEaseIn.java

package com.tencent.tws.assistant.animation.ease;

public class ElasticEaseIn extends BaseEase {

    public ElasticEaseIn(float duration) {
        super(duration);
    }

    @Override
    public Float calculate(float t, float b, float c, float d) {
        if (t == 0) return b;
        if ((t /= d) == 1) return b + c;
        float p = d * .3f;
        float a = c;
        float s = p / 4;
        return (a * (float) Math.pow(2, -10 * t) * (float) Math.sin((t * d - s) * (2 * (float) Math.PI) / p) + c + b);
    }
}