polygonizer.cpp

来自「一个很好的vc底层代码」· C++ 代码 · 共 279 行

/**********************************************************************
 * $Id: Polygonizer.cpp,v 1.6.2.1 2005/06/17 15:07:48 strk Exp $
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.refractions.net
 *
 * Copyright (C) 2001-2002 Vivid Solutions Inc.
 * Copyright (C) 2005 Refractions Research 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.
 *
 **********************************************************************/

#include <geos/opPolygonize.h>
#include <typeinfo>

//#define DEBUG 1

namespace geos {

Polygonizer::LineStringAdder::LineStringAdder(Polygonizer *p) {
	pol=p;
}

void Polygonizer::LineStringAdder::filter_rw(Geometry *g) {
	LineString *ls = dynamic_cast<LineString *>(g);
	if ( ls ) pol->add(ls);
}


/*
 * Create a polygonizer with the same GeometryFactory
 * as the input Geometry
 */
Polygonizer::Polygonizer() {
	lineStringAdder=new Polygonizer::LineStringAdder(this);
	graph=NULL;
	dangles=NULL;
	cutEdges=NULL;
	invalidRingLines=NULL;
	holeList=NULL;
	shellList=NULL;
	polyList=NULL;
}

Polygonizer::~Polygonizer()
{
	delete lineStringAdder;
	delete dangles;
	delete cutEdges;
	delete graph;

	delete holeList;
	delete shellList;
	if ( invalidRingLines )
	{
		for (unsigned int i=0; i<invalidRingLines->size(); i++)
			delete (*invalidRingLines)[i];
		delete invalidRingLines;
	}
	if ( polyList )
	{
		for (unsigned int i=0; i<polyList->size(); i++)
			delete (*polyList)[i];
		delete polyList;
	}
}

/*
 * Add a collection of geometries to be polygonized.
 * May be called multiple times.
 * Any dimension of Geometry may be added;
 * the constituent linework will be extracted and used
 *
 * @param geomList a list of {@link Geometry}s with linework to be polygonized
 */
void Polygonizer::add(vector<Geometry*> *geomList){
	for(int i=0;i<(int)geomList->size();i++) {
		Geometry *geometry=(*geomList)[i];
		add(geometry);
	}
}

/*
 * Add a geometry to the linework to be polygonized.
 * May be called multiple times.
 * Any dimension of Geometry may be added;
 * the constituent linework will be extracted and used
 *
 * @param g a Geometry with linework to be polygonized
 */
void Polygonizer::add(Geometry *g) {
	g->apply_rw(lineStringAdder);
}

/*
 * Add a linestring to the graph of polygon edges.
 *
 * @param line the LineString to add
 */
void Polygonizer::add(LineString *line){
	// create a new graph using the factory from the input Geometry
	if (graph==NULL)
		graph=new PolygonizeGraph(line->getFactory());
	graph->addEdge(line);
}

/*
 * Gets the list of polygons formed by the polygonization.
 * @return a collection of Polygons
 */
vector<Polygon*>*
Polygonizer::getPolygons()
{
	polygonize();
	vector<Polygon *> *ret = polyList;
	polyList = NULL;
	return ret;
}

/*
 * Get the list of dangling lines found during polygonization.
 * @return a collection of dangles LineStrings from input.
 */
vector<const LineString*>*
Polygonizer::getDangles(){
	polygonize();
	return dangles;
}

/*
 * Get the list of cut edges found during polygonization.
 * @return a collection of the input {@LineStrings} which are cut edges
 */
vector<const LineString*>*
Polygonizer::getCutEdges() {
	polygonize();
	return cutEdges;
}

/*
 * Get the list of lines forming invalid rings found during polygonization.
 * @return a collection of the input {@LineStrings} which form invalid rings
 */
vector<LineString*>*
Polygonizer::getInvalidRingLines()
{
	polygonize();
	vector<LineString*> *ret = invalidRingLines;
	invalidRingLines = NULL;
	return ret;
}

/*
 * Perform the polygonization, if it has not already been carried out.
 */
void
Polygonizer::polygonize()
{
	// check if already computed
	if (polyList!=NULL) return;

	polyList=new vector<Polygon*>();

	if (graph==NULL) // No valid geometries added
	{
		return; 
	}

	dangles=graph->deleteDangles();
	cutEdges=graph->deleteCutEdges();
	vector<polygonizeEdgeRing*> *edgeRingList=graph->getEdgeRings();
#if DEBUG
	cerr<<"Polygonizer::polygonize(): "<<edgeRingList->size()<<" edgeRings in graph"<<endl;
#endif
	vector<polygonizeEdgeRing*> *validEdgeRingList=new vector<polygonizeEdgeRing*>();
	invalidRingLines=new vector<LineString*>();
	findValidRings(edgeRingList, validEdgeRingList, invalidRingLines);
#if DEBUG
	cerr<<"                           "<<validEdgeRingList->size()<<" valid"<<endl;
	cerr<<"                           "<<invalidRingLines->size()<<" invalid"<<endl;
#endif
	delete edgeRingList;

	findShellsAndHoles(validEdgeRingList);
#if DEBUG
	cerr<<"                           "<<holeList->size()<<" holes"<<endl;
	cerr<<"                           "<<shellList->size()<<" shells"<<endl;
#endif

	assignHolesToShells(holeList, shellList);

	for (int i=0;i<(int)shellList->size();i++) {
		polygonizeEdgeRing *er=(*shellList)[i];
		polyList->push_back(er->getPolygon());
	}
	delete validEdgeRingList;
}

void
Polygonizer::findValidRings(vector<polygonizeEdgeRing*> *edgeRingList, vector<polygonizeEdgeRing*> *validEdgeRingList, vector<LineString*> *invalidRingList)
{
	for (int i=0;i<(int)edgeRingList->size();i++) {
		polygonizeEdgeRing *er=(*edgeRingList)[i];
		if (er->isValid())
			validEdgeRingList->push_back(er);
		else
		{
			invalidRingList->push_back(er->getLineString());
		}
	}
}

void
Polygonizer::findShellsAndHoles(vector<polygonizeEdgeRing*> *edgeRingList)
{
	holeList=new vector<polygonizeEdgeRing*>();
	shellList=new vector<polygonizeEdgeRing*>();
	for (int i=0;i<(int)edgeRingList->size();i++) {
		polygonizeEdgeRing *er=(*edgeRingList)[i];
		if (er->isHole())
			holeList->push_back(er);
		else
			shellList->push_back(er);
	}
}

void
Polygonizer::assignHolesToShells(vector<polygonizeEdgeRing*> *holeList,vector<polygonizeEdgeRing*> *shellList)
{
	for (int i=0;i<(int)holeList->size();i++) {
		polygonizeEdgeRing *holeER=(*holeList)[i];
		assignHoleToShell(holeER,shellList);
	}
}

void
Polygonizer::assignHoleToShell(polygonizeEdgeRing *holeER, vector<polygonizeEdgeRing*> *shellList)
{
	polygonizeEdgeRing *shell=polygonizeEdgeRing::findEdgeRingContaining(holeER, shellList);

	if (shell!=NULL)
		shell->addHole(holeER->getRingOwnership());
}


} // namespace geos

/**********************************************************************
 * $Log: Polygonizer.cpp,v $
 * Revision 1.6.2.1  2005/06/17 15:07:48  strk
 * Polygonizer segfault fix
 *
 * Revision 1.6  2004/12/08 13:54:44  strk
 * gcc warnings checked and fixed, general cleanups.
 *
 * Revision 1.5  2004/10/27 13:57:07  strk
 * Added some debugging lines (disabled by default)
 *
 * Revision 1.4  2004/10/26 16:09:21  strk
 * Some more intentation and envelope equality check fix.
 *
 * Revision 1.3  2004/10/19 19:51:14  strk
 * Fixed many leaks and bugs in Polygonizer.
 * Output still bogus.
 *
 * Revision 1.2  2004/07/02 13:28:29  strk
 * Fixed all #include lines to reflect headers layout change.
 * Added client application build tips in README.
 *
 * Revision 1.1  2004/04/08 04:53:56  ybychkov
 * "operation/polygonize" ported from JTS 1.4
 *
 *
 **********************************************************************/