Represents a directed graph which is embeddable in a planar surface. More...

#include <PlanarGraph.h>

Inheritance diagram for geos::geomgraph::PlanarGraph:

Public Member Functions
	PlanarGraph (const NodeFactory &nodeFact)

std::vector< Edge * >::iterator	getEdgeIterator ()

std::vector< EdgeEnd * > *	getEdgeEnds ()

bool	isBoundaryNode (uint8_t geomIndex, const geom::Coordinate &coord)

void	add (EdgeEnd *e)

NodeMap::iterator	getNodeIterator ()

void	getNodes (std::vector< Node * > &)

Node *	addNode (Node *node)

Node *	addNode (const geom::Coordinate &coord)

Node *	find (geom::Coordinate &coord)

void	addEdges (const std::vector< Edge * > &edgesToAdd)
	Add a set of edges to the graph. For each edge two DirectedEdges will be created. DirectedEdges are NOT linked by this method.

void	linkResultDirectedEdges ()

void	linkAllDirectedEdges ()

EdgeEnd *	findEdgeEnd (Edge *e)
	Returns the EdgeEnd which has edge e as its base edge (MD 18 Feb 2002 - this should return a pair of edges)

Edge *	findEdge (const geom::Coordinate &p0, const geom::Coordinate &p1)
	Returns the edge whose first two coordinates are p0 and p1.

Edge *	findEdgeInSameDirection (const geom::Coordinate &p0, const geom::Coordinate &p1)
	Returns the edge which starts at p0 and whose first segment is parallel to p1.

std::string	printEdges ()

NodeMap *	getNodeMap ()

Static Public Member Functions
template<typename It >
static void	linkResultDirectedEdges (It first, It last)
	For nodes in the collection (first..last), link the DirectedEdges at the node that are in the result.

Protected Member Functions
void	insertEdge (Edge *e)

Protected Attributes
std::vector< Edge * > *	edges

NodeMap *	nodes

std::vector< EdgeEnd * > *	edgeEndList

Detailed Description

Represents a directed graph which is embeddable in a planar surface.

The computation of the IntersectionMatrix relies on the use of a structure called a "topology graph". The topology graph contains nodes and edges corresponding to the nodes and line segments of a Geometry. Each node and edge in the graph is labeled with its topological location relative to the source geometry.

Note that there is no requirement that points of self-intersection be a vertex. Thus to obtain a correct topology graph, Geometry objects must be self-noded before constructing their graphs.

Two fundamental operations are supported by topology graphs:

Computing the intersections between all the edges and nodes of a single graph
Computing the intersections between the edges and nodes of two different graphs

Member Function Documentation

◆ find()

Node * geos::geomgraph::PlanarGraph::find ( geom::Coordinate & coord )

Returns: the node if found; null otherwise

◆ findEdge()

Edge * geos::geomgraph::PlanarGraph::findEdge	(	const geom::Coordinate &	p0,
		const geom::Coordinate &	p1
	)

Returns the edge whose first two coordinates are p0 and p1.

Returns: the edge, if found null if the edge was not found

◆ findEdgeEnd()

EdgeEnd * geos::geomgraph::PlanarGraph::findEdgeEnd ( Edge * e )

Returns the EdgeEnd which has edge e as its base edge (MD 18 Feb 2002 - this should return a pair of edges)

Returns: the edge, if found null if the edge was not found

◆ findEdgeInSameDirection()

Edge * geos::geomgraph::PlanarGraph::findEdgeInSameDirection	(	const geom::Coordinate &	p0,
		const geom::Coordinate &	p1
	)

Returns the edge which starts at p0 and whose first segment is parallel to p1.

Returns: the edge, if found null if the edge was not found

◆ linkResultDirectedEdges()

template<typename It >

static void geos::geomgraph::PlanarGraph::linkResultDirectedEdges	(	It	first,
		It	last
	)

inlinestatic

For nodes in the collection (first..last), link the DirectedEdges at the node that are in the result.

This allows clients to link only a subset of nodes in the graph, for efficiency (because they know that only a subset is of interest).

References geos::geomgraph::DirectedEdgeStar::linkResultDirectedEdges().

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

geomgraph/PlanarGraph.h

Public Member Functions

Static Public Member Functions

Protected Member Functions