com.vividsolutions.jts.edgegraph

Class EdgeGraph

java.lang.Object

com.vividsolutions.jts.edgegraph.EdgeGraph

public class EdgeGraph
extends Object

A graph comprised of HalfEdges. It supports tracking the vertices in the graph via edges incident on them, to allow efficient lookup of edges and vertices.

This class may be subclassed to use a different subclass of HalfEdge, by overriding createEdge(Coordinate). If additional logic is required to initialize edges then addEdge(Coordinate, Coordinate) can be overridden as well.

Author:

Martin Davis

Constructor Summary

Constructors

Constructor and Description
EdgeGraph()

Method Summary

Methods

Modifier and Type	Method and Description
HalfEdge	addEdge(Coordinate orig, Coordinate dest) Adds an edge between the coordinates orig and dest to this graph.
protected HalfEdge	createEdge(Coordinate orig) Creates a single HalfEdge.
HalfEdge	findEdge(Coordinate orig, Coordinate dest) Finds an edge in this graph with the given origin and destination, if one exists.
Collection	getVertexEdges()
static boolean	isValidEdge(Coordinate orig, Coordinate dest) Tests if the given coordinates form a valid edge (with non-zero length).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EdgeGraph

public EdgeGraph()

Method Detail

createEdge

protected HalfEdge createEdge(Coordinate orig)

Creates a single HalfEdge. Override to use a different HalfEdge subclass.

Parameters:

orig - the origin location

Returns:

a new HalfEdge with the given origin

addEdge

public HalfEdge addEdge(Coordinate orig,
               Coordinate dest)

Adds an edge between the coordinates orig and dest to this graph. Only valid edges can be added (in particular, zero-length segments cannot be added)

Parameters:

orig - the edge origin location

dest - the edge destination location.

Returns:

the created edge

See Also:

#isValidEdge(Coordinate, Coordinate)}

isValidEdge

public static boolean isValidEdge(Coordinate orig,
                  Coordinate dest)

Tests if the given coordinates form a valid edge (with non-zero length).

Parameters:

orig - the start coordinate

dest - the end coordinate

Returns:

true if the edge formed is valid

getVertexEdges

public Collection getVertexEdges()

findEdge

public HalfEdge findEdge(Coordinate orig,
                Coordinate dest)

Finds an edge in this graph with the given origin and destination, if one exists.

Parameters:

orig - the origin location

dest - the destination location.

Returns:

an edge with the given orig and dest, or null if none exists