VectorPathOutline.local constructor

VectorPathOutline.local(DiagramRect frame, DiagramVectorPath localPath, { double cornerRadius = 0, })

Resolves localPath, in shape-local units measured from the frame origin (not unit coordinates), at frame.

Implementation

factory VectorPathOutline.local(
  DiagramRect frame,
  DiagramVectorPath localPath, {
  double cornerRadius = 0,
}) {
  final path = localPath..validate();
  final nodes = [
    for (final n in path.nodes)
      n.copyWith(
        position: DiagramPoint(
          frame.left + n.position.x,
          frame.top + n.position.y,
        ),
      ),
  ];
  for (final node in nodes) {
    for (final point in [
      node.position,
      node.position + node.incoming,
      node.position + node.outgoing,
    ]) {
      if (!point.x.isFinite || !point.y.isFinite) {
        throw StateError('Resolved path coordinates must remain finite');
      }
    }
  }
  final segments = <List<DiagramPoint>>[];
  for (var i = 0; i < nodes.length - (path.closed ? 0 : 1); i++) {
    final a = nodes[i];
    final b = nodes[(i + 1) % nodes.length];
    final points = <DiagramPoint>[a.position];
    if (a.segment == DiagramPathSegmentKind.line) {
      points.add(b.position);
    } else {
      flattenCubic(
        a.position,
        a.position + a.outgoing,
        b.position + b.incoming,
        b.position,
        tolerance: curveTolerance,
        output: points,
      );
    }
    segments.add(points);
  }
  final points = _roundPathCorners(
    segments,
    closed: path.closed,
    radius: cornerRadius,
    corners: [
      for (final node in nodes) node.mode == DiagramPathHandleMode.corner,
    ],
  );
  // Control hull is conservative even for curves with extrema between anchors.
  final hull = [
    for (final n in nodes) ...[
      n.position,
      n.position + n.incoming,
      n.position + n.outgoing,
    ],
  ];
  final bounds = DiagramRect.fromPoints([...frame.corners, ...hull]);
  return VectorPathOutline._(
    bounds,
    List.unmodifiable(nodes),
    List.unmodifiable(points),
    path.closed,
  );
}