@Override
                    public void onAnimationUpdate(ValueAnimator valueAnimator) {
                        float t = valueAnimator.getAnimatedFraction();
                        mVisualizer.setCubicInterpolator(oldCx1 + t * (cx1 - oldCx1),
                                oldCy1 + t * (cy1 - oldCy1),
                                oldCx2 + t * (cx2 - oldCx2),
                                oldCy2 + t * (cy2 - oldCy2), callback);
                    }
Creates a cubic PathInterpolator, whose control points values can be changed
by the user dragging the handles around in the UI.
AnimationsInterpolatorPlayground/app/src/main/java/com/example/android/interpolatorplayground/MainActivity.java