Class PolygonHoleJoiner


  • public class PolygonHoleJoiner
    extends Object
    Transforms a polygon with holes into a single self-touching (invalid) ring by joining holes to the exterior shell or to another hole with out-and-back line segments. The holes are added in order of their envelopes (leftmost/lowest first). As the result shell develops, a hole may be added to what was originally another hole.

    There is no attempt to optimize the quality of the join lines. In particular, holes may be joined by lines longer than is optimal. However, holes which touch the shell or other holes are joined at the touch point.

    The class does not require the input polygon to have normal orientation (shell CW and rings CCW). The output ring is always CW.

    • Constructor Detail

      • PolygonHoleJoiner

        public PolygonHoleJoiner​(Polygon polygon)
        Creates a new hole joiner.
        Parameters:
        polygon - the polygon to join
    • Method Detail

      • joinAsPolygon

        public static Polygon joinAsPolygon​(Polygon polygon)
        Joins the shell and holes of a polygon and returns the result as an (invalid) Polygon.
        Parameters:
        inputPolygon - the polygon to join
        Returns:
        the result polygon
      • join

        public static Coordinate[] join​(Polygon polygon)
        Joins the shell and holes of a polygon and returns the result as sequence of Coordinates.
        Parameters:
        inputPolygon - the polygon to join
        Returns:
        the result coordinates
      • compute

        public Coordinate[] compute()
        Computes the joined ring.
        Returns:
        the points in the joined ring