Class PolygonHoleJoiner

java.lang.Object
org.locationtech.jts.triangulate.polygon.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 Details

    • PolygonHoleJoiner

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

    • 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