lerpFrom method

@override SplineElement lerpFrom(covariant SplineElement from, double t)

Linearly interpolate between this element and from.

Implementation

@override
SplineElement lerpFrom(covariant SplineElement from, double t) {
  final cubicsRst = <List<Offset>>[];

  var fromCubics = from.cubics;
  var toCubics = cubics;

  final dl = toCubics.length - fromCubics.length;
  if (dl > 0) {
    fromCubics = [...fromCubics, ...List.filled(dl, fromCubics.last)];
  } else if (dl < 0) {
    toCubics = [...toCubics, ...List.filled(-dl, toCubics.last)];
  }

  for (var i = 0; i < toCubics.length; i++) {
    cubicsRst.add([
      Offset.lerp(fromCubics[i][0], toCubics[i][0], t)!,
      Offset.lerp(fromCubics[i][1], toCubics[i][1], t)!,
      Offset.lerp(fromCubics[i][2], toCubics[i][2], t)!,
    ]);
  }

  return SplineElement(
    start: Offset.lerp(from.start, start, t)!,
    cubics: cubicsRst,
    style: style.lerpFrom(from.style, t),
    rotation: lerpDouble(from.rotation, rotation, t),
    rotationAxis: Offset.lerp(from.rotationAxis, rotationAxis, t),
    tag: tag,
  );
}