/********************************************************************** * * GEOS - Geometry Engine Open Source * http://geos.osgeo.org * * Copyright (C) 2006 Refractions Research Inc. * Copyright (C) 2001-2002 Vivid Solutions Inc. * * This is free software; you can redistribute and/or modify it under * the terms of the GNU Lesser General Public Licence as published * by the Free Software Foundation. * See the COPYING file for more information. * ********************************************************************** * * Last port: operation/polygonize/PolygonizeGraph.java rev. 974 * **********************************************************************/ #pragma once #include #include // for inheritance #include #ifdef _MSC_VER #pragma warning(push) #pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class #endif // Forward declarations namespace geos { namespace geom { class LineString; class GeometryFactory; class Coordinate; class CoordinateSequence; } namespace planargraph { class Node; class Edge; class DirectedEdge; } namespace operation { namespace polygonize { class EdgeRing; class PolygonizeDirectedEdge; } } } namespace geos { namespace operation { // geos::operation namespace polygonize { // geos::operation::polygonize /** \brief * 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. * */ class GEOS_DLL PolygonizeGraph: public planargraph::PlanarGraph { public: /** * \brief * Deletes all edges at a node */ static void deleteAllEdges(planargraph::Node* node); /** * \brief * Create a new polygonization graph. */ explicit PolygonizeGraph(const geom::GeometryFactory* newFactory); /** * \brief * Destroy a polygonization graph. */ ~PolygonizeGraph() override; /** * \brief * Add a LineString forming an edge of the polygon graph. * @param line the line to add */ void addEdge(const geom::LineString* line); /** * \brief * Computes the EdgeRings formed by the edges in this graph. * * @param edgeRingList : the EdgeRing found by the * polygonization process will be pushed here. * */ void getEdgeRings(std::vector& edgeRingList); /** * \brief * Finds and removes all cut edges from the graph. * * @param cutLines : the list of the LineString forming the removed * cut edges will be pushed here. * * TODO: document ownership of the returned LineStrings */ void deleteCutEdges(std::vector& cutLines); /** \brief * 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 * * @param dangleLines : the LineStrings that formed dangles will * be push_back'ed here */ void deleteDangles(std::vector& dangleLines); private: static int getDegreeNonDeleted(planargraph::Node* node); static int getDegree(planargraph::Node* node, long label); const geom::GeometryFactory* factory; planargraph::Node* getNode(const geom::Coordinate& pt); void computeNextCWEdges(); /** * \brief * Convert the maximal edge rings found by the initial graph traversal * into the minimal edge rings required by JTS polygon topology rules. * * @param ringEdges * the list of start edges for the edgeRings to convert. * */ void convertMaximalToMinimalEdgeRings( std::vector& ringEdges); /** * \brief * Finds all nodes in a maximal edgering * which are self-intersection nodes * * @param startDE * @param label * @param intNodes : intersection nodes found will be pushed here * the vector won't be cleared before pushing. */ static void findIntersectionNodes(PolygonizeDirectedEdge* startDE, long label, std::vector& intNodes ); /** * Finds and labels all edgerings in the graph. * * The edge rings are labeling with unique integers. * The labeling allows detecting cut edges. * * @param dirEdgesIn a list of the DirectedEdges in the graph * @param dirEdgesOut each ring found will be pushed here */ static void findLabeledEdgeRings( std::vector& dirEdgesIn, std::vector& dirEdgesOut); static void label(std::vector& dirEdges, long label); static void label(std::vector& dirEdges, long label); static void computeNextCWEdges(planargraph::Node* node); /** * \brief * Computes the next edge pointers going CCW around the given node, * for the given edgering label. * This algorithm has the effect of converting maximal edgerings * into minimal edgerings */ static void computeNextCCWEdges(planargraph::Node* node, long label); EdgeRing* findEdgeRing(PolygonizeDirectedEdge* startDE); /* Tese are for memory management */ std::vector newEdges; std::vector newDirEdges; std::vector newNodes; std::vector newEdgeRings; std::vector newCoords; }; } // namespace geos::operation::polygonize } // namespace geos::operation } // namespace geos #ifdef _MSC_VER #pragma warning(pop) #endif