private void setupPathInterpolator() {
        if (mQuadraticPath) {
            mInterpolator = new PathInterpolator(mCx1, mCy1);
            if (mPathCallback != null) {
                mPathCallback.onControlPoint1Moved(mCx1, mCy1);
            }
        } else if (mCubicPath) {
            mInterpolator = new PathInterpolator(mCx1, mCy1, mCx2, mCy2);
            if (mPathCallback != null) {
                mPathCallback.onControlPoint1Moved(mCx1, mCy1);
                mPathCallback.onControlPoint2Moved(mCx2, mCy2);
            }
        }
        invalidate();
    }
Sets the current interpolator. Note that a PathInterpolator must be set via
{@link #setQuadraticInterpolator(float, float, ControlPointCallback)} or
{@link #setCubicInterpolator(float, float, float, float, ControlPointCallback)}.
AnimationsInterpolatorPlayground/app/src/main/java/com/example/android/interpolatorplayground/CurveVisualizer.java