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. More...
#include <PolygonizeGraph.h>
Public Member Functions | |
PolygonizeGraph (const geom::GeometryFactory *newFactory) | |
Create a new polygonization graph. | |
~PolygonizeGraph () | |
Destroy a polygonization graph. | |
void | addEdge (const geom::LineString *line) |
Add a LineString forming an edge of the polygon graph. | |
void | getEdgeRings (std::vector< EdgeRing * > &edgeRingList) |
Computes the EdgeRings formed by the edges in this graph. | |
void | deleteCutEdges (std::vector< const geom::LineString * > &cutLines) |
Finds and removes all cut edges from the graph. | |
void | deleteDangles (std::vector< const geom::LineString * > &dangleLines) |
Marks all edges from the graph which are "dangles". | |
Static Public Member Functions | |
static void | deleteAllEdges (planargraph::Node *node) |
Deletes all edges at a node. |
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 DirectedEdge is used to indicate that a directed edge has be logically deleted from the graph.
void geos::operation::polygonize::PolygonizeGraph::addEdge | ( | const geom::LineString * | line | ) |
Add a LineString forming an edge of the polygon graph.
line | the line to add |
void geos::operation::polygonize::PolygonizeGraph::deleteCutEdges | ( | std::vector< const geom::LineString * > & | cutLines | ) |
Finds and removes all cut edges from the graph.
cutLines | : the list of the LineString forming the removed cut edges will be pushed here. |
TODO: document ownership of the returned LineStrings
void geos::operation::polygonize::PolygonizeGraph::deleteDangles | ( | std::vector< const geom::LineString * > & | dangleLines | ) |
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
dangleLines | : the LineStrings that formed dangles will be push_back'ed here |
void geos::operation::polygonize::PolygonizeGraph::getEdgeRings | ( | std::vector< EdgeRing * > & | edgeRingList | ) |
Computes the EdgeRings formed by the edges in this graph.
edgeRingList | : the EdgeRing found by the polygonization process will be pushed here. |