How to apply easing animation function on view in Android

Question

I want to apply a translate animation on an Android view (button) using a custom interpolator where the easing function is:

public static float easeOut(float t,float b , float c, float d) {
    if ((t/=d) < (1/2.75f)) {
       return c*(7.5625f*t*t) + b;
    } else if (t < (2/2.75f)) {
       return c*(7.5625f*(t-=(1.5f/2.75f))*t + .75f) + b;
    } else if (t < (2.5/2.75)) {
       return c*(7.5625f*(t-=(2.25f/2.75f))*t + .9375f) + b;
    } else {
       return c*(7.5625f*(t-=(2.625f/2.75f))*t + .984375f) + b;
    }
}

I have an example that uses the custom interpolator like this:

The interpolator is:

public class HesitateInterpolator implements Interpolator {
    public HesitateInterpolator() {
    }

    public float getInterpolation(float t) {
        float x = 2.0f * t - 1.0f;
        return 0.5f * (x * x * x + 1.0f);
    }
}

and is used like this:

ScaleAnimation anim = new ScaleAnimation(0.0f, 1.0f, 0.0f, 1.0f);
anim.setInterpolator(new HesitateInterpolator());

My question is: What are these values b, c, d for?

Answer 1

1,2,3 go

1. Create a custom cubic bezier curve using this awesome site. And get the control points for the curve. Between 0,0 and 1,1
2. Interpolator customInterpolator = PathInterpolatorCompat.create(cpX1,cpX2,cpY1,cpY2)
3. Add this customInterpolator to any of your animation.

Added a gist. Some more here.

Answer 2

FYI: for people who just want an ease interpolator you can just use myAnimator.setInterpolator(new AccelerateDecelerateInterpolator());