geos::edgegraph::EdgeGraph Class Reference

#include <EdgeGraph.h>

Public Member Functions
	EdgeGraph ()
HalfEdge *	addEdge (const geom::Coordinate &orig, const geom::Coordinate &dest)
void	getVertexEdges (std::vector< const HalfEdge * > &edgesOut)
HalfEdge *	findEdge (const geom::Coordinate &orig, const geom::Coordinate &dest)

Static Public Member Functions
static bool	isValidEdge (const geom::Coordinate &orig, const geom::Coordinate &dest)

Protected Member Functions
HalfEdge *	createEdge (const geom::Coordinate &orig)
HalfEdge *	insert (const geom::Coordinate &orig, const geom::Coordinate &dest, HalfEdge *eAdj)

Detailed Description

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. If additional logic is required to initialize edges then addEdge can be overridden as well.

Author

Martin Davis

Constructor & Destructor Documentation

EdgeGraph()

geos::edgegraph::EdgeGraph::EdgeGraph ( )

inline

Initialized

Member Function Documentation

addEdge()

HalfEdge * geos::edgegraph::EdgeGraph::addEdge	(	const geom::Coordinate &	orig,
		const geom::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

null if the edge was invalid and not added

See also

isValidEdge(Coordinate, Coordinate)

createEdge()

HalfEdge * geos::edgegraph::EdgeGraph::createEdge ( const geom::Coordinate &  orig )

protected

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

Parameters

orig	the origin location

Returns

a new HalfEdge with the given origin

findEdge()

HalfEdge * geos::edgegraph::EdgeGraph::findEdge	(	const geom::Coordinate &	orig,
		const geom::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

insert()

HalfEdge * geos::edgegraph::EdgeGraph::insert ( const geom::Coordinate &  orig, const geom::Coordinate &  dest, HalfEdge *  eAdj  )

protected

Inserts an edge not already present into the graph.

Parameters

orig	the edge origin location
dest	the edge destination location
eAdj	an existing edge with same orig (if any)

Returns

the created edge

isValidEdge()

static bool geos::edgegraph::EdgeGraph::isValidEdge ( const geom::Coordinate &  orig, const geom::Coordinate &  dest  )

static

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

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The documentation for this class was generated from the following file:

• EdgeGraph.h