interpolate method

Implementation

@override
Animation interpolate(Animation current, double scroll) {
  final translate = current as TranslateAnimation;
  final factor = translate.factor(scroll);

  return TranslateAnimation(
    start: start,
    end: end,
    x: (x + (translate.x - x) * factor).round(),
    y: (y + (translate.y - y) * factor).round(),
  );
}