Package org.locationtech.jts.operation.polygonize

Class EdgeRing

java.lang.Object
org.locationtech.jts.operation.polygonize.EdgeRing
class EdgeRing extends Object
Represents a ring of PolygonizeDirectedEdges which form a ring of a polygon. The ring may be either an outer shell or a hole.
Version:
1.7

  • Field Details

    • factory

      private GeometryFactory factory

    • deList

      private List deList

    • lowestEdge

      private DirectedEdge lowestEdge

    • ring

      private LinearRing ring

    • ringPts

      private Coordinate[] ringPts

    • holes

      private List holes

    • shell

      private EdgeRing shell

    • isHole

      private boolean isHole

    • isProcessed

      private boolean isProcessed

    • isIncludedSet

      private boolean isIncludedSet

    • isIncluded

      private boolean isIncluded

  • Constructor Details

  • Method Details

    • findEdgeRingContaining

      public static EdgeRing findEdgeRingContaining(EdgeRing testEr, List shellList)
      Find the innermost enclosing shell EdgeRing containing the argument EdgeRing, if any. The innermost enclosing ring is the smallest enclosing ring. The algorithm used depends on the fact that:
      ring A contains ring B iff envelope(ring A) contains envelope(ring B)
      This routine is only safe to use if the chosen point of the hole is known to be properly contained in a shell (which is guaranteed to be the case if the hole does not touch its shell)
      Returns:
      containing EdgeRing, if there is one or null if no containing EdgeRing is found

    • ptNotInList

      public static Coordinate ptNotInList(Coordinate[] testPts, Coordinate[] pts)
      Deprecated.
      Use CoordinateArrays.ptNotInList instead
      Finds a point in a list of points which is not contained in another list of points
      Parameters:
      testPts - the Coordinates to test
      pts - an array of Coordinates to test the input points against
      Returns:
      a Coordinate from testPts which is not in pts, or null if there is no coordinate not in the list

    • isInList

      public static boolean isInList(Coordinate pt, Coordinate[] pts)
      Deprecated.
      Tests whether a given point is in an array of points. Uses a value-based test.
      Parameters:
      pt - a Coordinate for the test point
      pts - an array of Coordinates to test
      Returns:
      true if the point is in the array

    • findDirEdgesInRing

      public static List findDirEdgesInRing(PolygonizeDirectedEdge startDE)
      Traverses a ring of DirectedEdges, accumulating them into a list. This assumes that all dangling directed edges have been removed from the graph, so that there is always a next dirEdge.
      Parameters:
      startDE - the DirectedEdge to start traversing at
      Returns:
      a List of DirectedEdges that form a ring

    • build

      public void build(PolygonizeDirectedEdge startDE)

    • add

      private void add(DirectedEdge de)
      Adds a DirectedEdge which is known to form part of this ring.
      Parameters:
      de - the DirectedEdge to add.

    • isHole

      public boolean isHole()
      Tests whether this ring is a hole.
      Returns:
      true if this ring is a hole

    • computeHole

      public void computeHole()
      Computes whether this ring is a hole. Due to the way the edges in the polygonization graph are linked, a ring is a hole if it is oriented counter-clockwise.

    • addHole

      public void addHole(LinearRing hole)
      Adds a hole to the polygon formed by this ring.
      Parameters:
      hole - the LinearRing forming the hole.

    • addHole

      public void addHole(EdgeRing holeER)
      Adds a hole to the polygon formed by this ring.
      Parameters:
      hole - the LinearRing forming the hole.

    • getPolygon

      public Polygon getPolygon()
      Computes the Polygon formed by this ring and any contained holes.
      Returns:
      the Polygon formed by this ring and its holes.

    • isValid

      public boolean isValid()
      Tests if the LinearRing ring formed by this edge ring is topologically valid.
      Returns:
      true if the ring is valid

    • isIncludedSet

      public boolean isIncludedSet()

    • isIncluded

      public boolean isIncluded()

    • setIncluded

      public void setIncluded(boolean isIncluded)

    • getCoordinates

      private Coordinate[] getCoordinates()
      Computes the list of coordinates which are contained in this ring. The coordinates are computed once only and cached.
      Returns:
      an array of the Coordinates in this ring

    • getLineString

      public LineString getLineString()
      Gets the coordinates for this ring as a LineString. Used to return the coordinates in this ring as a valid geometry, when it has been detected that the ring is topologically invalid.
      Returns:
      a LineString containing the coordinates in this ring

    • getRing

      public LinearRing getRing()
      Returns this ring as a LinearRing, or null if an Exception occurs while creating it (such as a topology problem). Details of problems are written to standard output.

    • addEdge

      private static void addEdge(Coordinate[] coords, boolean isForward, CoordinateList coordList)

    • setShell

      public void setShell(EdgeRing shell)
      Sets the containing shell ring of a ring that has been determined to be a hole.
      Parameters:
      shell - the shell ring

    • hasShell

      public boolean hasShell()
      Tests whether this ring has a shell assigned to it.
      Returns:
      true if the ring has a shell

    • getShell

      public EdgeRing getShell()
      Gets the shell for this ring. The shell is the ring itself if it is not a hole, otherwise its parent shell.
      Returns:
      the shell for this ring

    • isOuterHole

      public boolean isOuterHole()
      Tests whether this ring is an outer hole. A hole is an outer hole if it is not contained by a shell.
      Returns:
      true if the ring is an outer hole.

    • isOuterShell

      public boolean isOuterShell()
      Tests whether this ring is an outer shell.
      Returns:
      true if the ring is an outer shell.

    • getOuterHole

      public EdgeRing getOuterHole()

    • updateIncluded

      public void updateIncluded()
      Updates the included status for currently non-included shells based on whether they are adjacent to an included shell.

    • toString

      public String toString()
      Gets a string representation of this object.
      Overrides:
      toString in class Object
      Returns:
      a string representing the object

    • isProcessed

      public boolean isProcessed()
      Returns:
      whether the ring has been processed

    • setProcessed

      public void setProcessed(boolean isProcessed)
      Parameters:
      isProcessed - whether the ring has been processed