- covariant WaveClipper oldClipper
Called whenever a new instance of the custom clipper delegate class is provided to the clip object, or any time that a new clip object is created with a new instance of the custom painter delegate class (which amounts to the same thing, because the latter is implemented in terms of the former).
If the new instance represents different information than the old instance, then the method should return true, otherwise it should return false.
If the method returns false, then the getClip call might be optimized away.
@override bool shouldReclip(WaveClipper oldClipper) => animationValue != oldClipper.animationValue;