issimpleop.cpp

来自「一个很好的vc底层代码」· C++ 代码 · 共 193 行

/**********************************************************************
 * $Id: IsSimpleOp.cpp,v 1.14 2004/12/08 13:54:43 strk Exp $
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.refractions.net
 *
 * 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.
 *
 **********************************************************************
 * $Log: IsSimpleOp.cpp,v $
 * Revision 1.14  2004/12/08 13:54:43  strk
 * gcc warnings checked and fixed, general cleanups.
 *
 * Revision 1.13  2004/07/02 13:28:27  strk
 * Fixed all #include lines to reflect headers layout change.
 * Added client application build tips in README.
 *
 * Revision 1.12  2003/11/07 01:23:42  pramsey
 * Add standard CVS headers licence notices and copyrights to all cpp and h
 * files.
 *
 *
 **********************************************************************/


#include <geos/operation.h>
#include <stdio.h>
#include <set>

namespace geos {

IsSimpleOp::IsSimpleOp(){}

bool IsSimpleOp::isSimple(const LineString *geom){
	return isSimpleLinearGeometry(geom);
}

bool IsSimpleOp::isSimple(const MultiLineString *geom){
	return isSimpleLinearGeometry(geom);
}

/**
* A MultiPoint is simple iff it has no repeated points
*/
bool IsSimpleOp::isSimple(const MultiPoint *mp) {
	if (mp->isEmpty()) return true;
	set<Coordinate,CoordLT> *points=new set<Coordinate,CoordLT>();
	for(int i=0;i<mp->getNumGeometries();i++) {
		Point *pt=(Point*) mp->getGeometryN(i);
		const Coordinate* p=pt->getCoordinate();
		if (points->find(*p)!=points->end()) {
			delete points;
			return false;
		}
		points->insert(*p);
	}
	delete points;
	return true;
}

bool IsSimpleOp::isSimpleLinearGeometry(const Geometry *geom){
	if (geom->isEmpty()) return true;
	GeometryGraph *graph=new GeometryGraph(0,geom);
	LineIntersector *li=new RobustLineIntersector();
	SegmentIntersector *si=graph->computeSelfNodes(li,true);
	// if no self-intersection, must be simple
	if (!si->hasIntersection()) {
		delete graph;
		delete li;
		delete si;
		return true;
	}
	if (si->hasProperIntersection()) {
		delete graph;
		delete li;
		delete si;
		return false;
	}
	if (hasNonEndpointIntersection(graph)) {
		delete graph;
		delete li;
		delete si;
		return false;
	}
	if (hasClosedEndpointIntersection(graph)) {
		delete graph;
		delete li;
		delete si;
		return false;
	}
	delete graph;
	delete li;
	delete si;
	return true;
}

/**
* For all edges, check if there are any intersections which are NOT at an endpoint.
* The Geometry is not simple if there are intersections not at endpoints.
*/
bool IsSimpleOp::hasNonEndpointIntersection(GeometryGraph *graph) {
	vector<Edge*> *edges=graph->getEdges();
	for (vector<Edge*>::iterator i=edges->begin();i<edges->end();i++) {
		Edge *e=*i;
		int maxSegmentIndex=e->getMaximumSegmentIndex();
		EdgeIntersectionList *eiL=e->getEdgeIntersectionList();
		vector<EdgeIntersection*> *intList=eiL->list;
		for(vector<EdgeIntersection*>::iterator eiIt=intList->begin();eiIt<intList->end();eiIt++) {
			EdgeIntersection *ei=*eiIt;
			if (!ei->isEndPoint(maxSegmentIndex))
				return true;
		}
	}
	return false;
}

/**
* Test that no edge intersection is the
* endpoint of a closed line.  To check this we compute the
* degree of each endpoint. The degree of endpoints of closed lines
* must be exactly 2.
*/
bool IsSimpleOp::hasClosedEndpointIntersection(GeometryGraph *graph) {
	map<Coordinate,EndpointInfo*,CoordLT> *endPoints=new map<Coordinate,EndpointInfo*,CoordLT>();
	vector<Edge*> *edges=graph->getEdges();
	for (vector<Edge*>::iterator i=edges->begin();i<edges->end();i++) {
		Edge *e=*i;
		//int maxSegmentIndex=e->getMaximumSegmentIndex();
		bool isClosed=e->isClosed();
		const Coordinate& p0=e->getCoordinate(0);
		addEndpoint(endPoints,p0,isClosed);
		const Coordinate& p1=e->getCoordinate(e->getNumPoints()-1);
		addEndpoint(endPoints,p1,isClosed);
	}
	map<Coordinate,EndpointInfo*,CoordLT>::iterator it=endPoints->begin();
	for (;it!=endPoints->end();it++) {
		EndpointInfo *eiInfo=it->second;
		if (eiInfo->isClosed && eiInfo->degree!=2) {
			map<Coordinate,EndpointInfo*,CoordLT>::iterator dit=endPoints->begin();
			for (;dit!=endPoints->end();dit++) {
				EndpointInfo *ep=dit->second;
				delete ep;
			}
			delete endPoints;
            return true;
		}
	}
	map<Coordinate,EndpointInfo*,CoordLT>::iterator dit=endPoints->begin();
	for (;dit!=endPoints->end();dit++) {
		EndpointInfo *ep=dit->second;
		delete ep;
	}
	delete endPoints;
	return false;
}

/**
* Add an endpoint to the map, creating an entry for it if none exists
*/
void IsSimpleOp::addEndpoint(map<Coordinate,EndpointInfo*,CoordLT> *endPoints,
		const Coordinate& p,bool isClosed) {
	map<Coordinate,EndpointInfo*,CoordLT>::iterator it=endPoints->find(p);
	EndpointInfo *eiInfo;
	if (it==endPoints->end()) {
		eiInfo=NULL;
	} else {
		eiInfo=it->second;
	}
	if (eiInfo==NULL) {
		eiInfo=new EndpointInfo(p);
		(*endPoints)[p]=eiInfo;
	}
	eiInfo->addEndpoint(isClosed);
}

EndpointInfo::EndpointInfo(const Coordinate& newPt) {
	pt.setCoordinate(newPt);
	isClosed=false;
	degree=0;
}

void EndpointInfo::addEndpoint(bool newIsClosed) {
	degree++;
	isClosed|=newIsClosed;
}
}