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) More...

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

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. More...

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. More...

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