GEOS
3.14.0dev
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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 () override | |
Destroy a polygonization graph. | |
void | addEdge (const geom::LineString *line) |
Add a LineString forming an edge of the polygon graph. More... | |
void | getEdgeRings (std::vector< EdgeRing * > &edgeRingList) |
Computes the EdgeRings formed by the edges in this graph. More... | |
void | deleteCutEdges (std::vector< const geom::LineString * > &cutLines) |
Finds and removes all cut edges from the graph. More... | |
void | deleteDangles (std::vector< const geom::LineString * > &dangleLines) |
Marks all edges from the graph which are "dangles". More... | |
Public Member Functions inherited from geos::planargraph::PlanarGraph | |
PlanarGraph () | |
Constructs a PlanarGraph without any Edges, DirectedEdges, or Nodes. | |
Node * | findNode (const geom::Coordinate &pt) |
Returns the Node at the given location, or null if no Node was there. | |
NodeMap::container::iterator | nodeIterator () |
Returns an Iterator over the Nodes in this PlanarGraph. | |
NodeMap::container::iterator | nodeBegin () |
NodeMap::container::const_iterator | nodeBegin () const |
NodeMap::container::iterator | nodeEnd () |
NodeMap::container::const_iterator | nodeEnd () const |
void | getNodes (std::vector< Node * > &nodes) |
Returns the Nodes in this PlanarGraph. More... | |
std::vector< DirectedEdge * >::iterator | dirEdgeIterator () |
Returns an Iterator over the DirectedEdges in this PlanarGraph, in the order in which they were added. More... | |
std::vector< DirectedEdge * >::iterator | dirEdgeBegin () |
std::vector< DirectedEdge * >::iterator | dirEdgeEnd () |
std::vector< Edge * >::iterator | edgeIterator () |
Alias for edgeBegin() | |
std::vector< Edge * >::iterator | edgeBegin () |
Returns an iterator to first Edge in this graph. More... | |
std::vector< Edge * >::iterator | edgeEnd () |
Returns an iterator to one-past last Edge in this graph. More... | |
std::vector< Edge * > * | getEdges () |
void | remove (Edge *edge) |
Removes an Edge and its associated DirectedEdges from their from-Nodes and from this PlanarGraph. More... | |
void | remove (DirectedEdge *de) |
Removes DirectedEdge from its from-Node and from this PlanarGraph. More... | |
void | remove (Node *node) |
Removes a node from the graph, along with any associated DirectedEdges and Edges. | |
std::vector< Node * > * | findNodesOfDegree (std::size_t degree) |
Returns all Nodes with the given number of Edges around it. The return value is a newly allocated vector of existing nodes. | |
void | findNodesOfDegree (std::size_t degree, std::vector< Node * > &to) |
Get all Nodes with the given number of Edges around it. More... | |
Static Public Member Functions | |
static void | deleteAllEdges (planargraph::Node *node) |
Deletes all edges at a node. | |
Additional Inherited Members | |
Public Types inherited from geos::planargraph::PlanarGraph | |
typedef std::vector< Edge * > | EdgeContainer |
typedef EdgeContainer::iterator | EdgeIterator |
Protected Member Functions inherited from geos::planargraph::PlanarGraph | |
void | add (Node *node) |
Adds a node to the std::map, replacing any that is already at that location. More... | |
void | add (Edge *edge) |
Adds the Edge and its DirectedEdges with this PlanarGraph. More... | |
void | add (DirectedEdge *dirEdge) |
Adds the Edge to this PlanarGraph. More... | |
Protected Attributes inherited from geos::planargraph::PlanarGraph | |
std::vector< Edge * > | edges |
std::vector< DirectedEdge * > | dirEdges |
NodeMap | nodeMap |
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. |