public void setQuadraticInterpolator(float cx1, float cy1, ControlPointCallback callback) {
        mCx1 = cx1;
        mCy1 = cy1;
        mQuadraticPath = true;
        mCubicPath = false;
        mPathCallback = callback;
        setupPathInterpolator();
    }
Sets a quadratic PathInterpolator, along with a callback object to update the
UI when the control point is moved by the user.
AnimationsInterpolatorPlayground/app/src/main/java/com/example/android/interpolatorplayground/CurveVisualizer.java