public HalfPlane2D GetPortSide() => HalfPlane2D.FromDirectionAndBoundaryPoint(Direction.RotateQuarterTurn(), BasePoint);
public HalfPlane2D GetStarboardSide() => HalfPlane2D.FromDirectionAndBoundaryPoint(Direction.RotateReverseQuarterTurn(), BasePoint);
/// <summary>
/// Construct the line perpendicular to <paramref name="offsetDirection"/> through
/// <paramref name="pointOnLine"/>.
/// </summary>
public BoundaryLine2D(Direction2D offsetDirection, Point2D pointOnLine)
: this(HalfPlane2D.FromDirectionAndBoundaryPoint(offsetDirection, pointOnLine))
{
}