rotateAroundPointRaw method

MoveAndRotateResult rotateAroundPointRaw(double degree, { required Point<double>? point, required Offset? offset, required bool hasGesture, required MapEventSource source, String? id, })

Internal endpoint to rotate around a point that is not in the center of the map.

Implementation

MoveAndRotateResult rotateAroundPointRaw(
  double degree, {
  required Point<double>? point,
  required Offset? offset,
  required bool hasGesture,
  required MapEventSource source,
  String? id,
}) {
  if (point != null && offset != null) {
    throw ArgumentError('Only one of `point` or `offset` may be non-null');
  }
  if (point == null && offset == null) {
    throw ArgumentError('One of `point` or `offset` must be non-null');
  }

  if (degree == camera.rotation) {
    return const (moveSuccess: false, rotateSuccess: false);
  }

  if (offset == Offset.zero) {
    return (
      moveSuccess: true,
      rotateSuccess: rotateRaw(
        degree,
        hasGesture: hasGesture,
        source: source,
        id: id,
      ),
    );
  }

  final rotationDiff = degree - camera.rotation;
  final rotationCenter = camera.project(camera.center) +
      (point != null
              ? (point - (camera.nonRotatedSize / 2.0))
              : Point(offset!.dx, offset.dy))
          .rotate(camera.rotationRad);

  return (
    moveSuccess: moveRaw(
      camera.unproject(
        rotationCenter +
            (camera.project(camera.center) - rotationCenter)
                .rotate(degrees2Radians * rotationDiff),
      ),
      camera.zoom,
      hasGesture: hasGesture,
      source: source,
      id: id,
    ),
    rotateSuccess: rotateRaw(
      camera.rotation + rotationDiff,
      hasGesture: hasGesture,
      source: source,
      id: id,
    ),
  );
}