Class PolygonizeGraph

Namespace

NetTopologySuite.Operation.Polygonize

Assembly

NetTopologySuite.dll

Represents a planar graph of edges that can be used to compute a polygonization, and implements the algorithms to compute the EdgeRings formed by the graph. The marked flag on DirectedEdges is used to indicate that a directed edge has be logically deleted from the graph.

public class PolygonizeGraph : PlanarGraph

Inheritance

object

PlanarGraph

PolygonizeGraph

Inherited Members

PlanarGraph.dirEdges

PlanarGraph.nodeMap

PlanarGraph.FindNode(Coordinate)

PlanarGraph.Add(Node)

PlanarGraph.Add(Edge)

PlanarGraph.Add(DirectedEdge)

PlanarGraph.GetNodeEnumerator()

PlanarGraph.GetDirEdgeEnumerator()

PlanarGraph.GetEdgeEnumerator()

PlanarGraph.Remove(Edge)

PlanarGraph.Remove(DirectedEdge)

PlanarGraph.Remove(Node)

PlanarGraph.FindNodesOfDegree(int)

PlanarGraph.Nodes

PlanarGraph.Edges

object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Constructors

PolygonizeGraph(GeometryFactory)

Create a new polygonization graph.

public PolygonizeGraph(GeometryFactory factory)

Parameters

factory GeometryFactory

Methods

AddEdge(LineString)

Add a LineString forming an edge of the polygon graph.

public void AddEdge(LineString line)

Parameters

line LineString

The line to add.

ComputeDepthParity()

Traverses the polygonized edge rings in the graph and computes the depth parity (odd or even) relative to the exterior of the graph.

If the client has requested that the output be polygonally valid, only odd polygons will be constructed.

public void ComputeDepthParity()

DeleteAllEdges(Node)

Deletes all edges at a node.

public static void DeleteAllEdges(Node node)

Parameters

node Node

DeleteCutEdges()

Finds and removes all cut edges from the graph.

public IList<LineString> DeleteCutEdges()

Returns

IList<LineString>

A list of the LineStrings forming the removed cut edges.

DeleteDangles()

Marks all edges from the graph which are "dangles". Dangles are which are incident on a node with degree 1. This process is recursive, since removing a dangling edge may result in another edge becoming a dangle. In order to handle large recursion depths efficiently, an explicit recursion stack is used.

public ICollection<LineString> DeleteDangles()

Returns

ICollection<LineString>

A List containing the LineStrings that formed dangles.

GetEdgeRings()

Computes the minimal EdgeRings formed by the edges in this graph.

public IList<EdgeRing> GetEdgeRings()

Returns

IList<EdgeRing>

A list of the{EdgeRings found by the polygonization process.