oprelate.h

一个很好的vc代码

/**********************************************************************
 * $Id: opRelate.h,v 1.3 2004/07/27 16:35:46 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: opRelate.h,v $
 * Revision 1.3  2004/07/27 16:35:46  strk
 * Geometry::getEnvelopeInternal() changed to return a const Envelope *.
 * This should reduce object copies as once computed the envelope of a
 * geometry remains the same.
 *
 * Revision 1.2  2004/07/19 13:19:31  strk
 * Documentation fixes
 *
 * Revision 1.1  2004/07/02 13:20:42  strk
 * Header files moved under geos/ dir.
 *
 * Revision 1.15  2004/03/29 06:59:24  ybychkov
 * "noding/snapround" package ported (JTS 1.4);
 * "operation", "operation/valid", "operation/relate" and "operation/overlay" upgraded to JTS 1.4;
 * "geom" partially upgraded.
 *
 * Revision 1.14  2004/03/19 09:48:46  ybychkov
 * "geomgraph" and "geomgraph/indexl" upgraded to JTS 1.4
 *
 * Revision 1.13  2004/03/01 22:04:59  strk
 * applied const correctness changes by Manuel Prieto Villegas <[e-mail]>
 *
 * Revision 1.12  2003/11/07 01:23:42  pramsey
 * Add standard CVS headers licence notices and copyrights to all cpp and h
 * files.
 *
 *
 **********************************************************************/


#ifndef GEOS_OPRELATE_H
#define GEOS_OPRELATE_H

#include <memory>
#include <string>
#include <vector>
#include <geos/platform.h>
#include <geos/operation.h>
#include <geos/geomgraph.h>
#include <geos/geosAlgorithm.h>

namespace geos {

/*
 * Represents a node in the topological graph used to compute spatial
 * relationships.
 */
class RelateNode: public Node {
public:
	RelateNode(Coordinate& coord,EdgeEndStar *edges);
	virtual ~RelateNode();
	void updateIMFromEdges(IntersectionMatrix *im);
protected:
	void computeIM(IntersectionMatrix *im);
};

/*
 * Computes the EdgeEnd objects which arise from a noded Edge.
 */
class EdgeEndBuilder {
public:
	EdgeEndBuilder();
	vector<EdgeEnd*> *computeEdgeEnds(vector<Edge*> *edges);
	void computeEdgeEnds(Edge *edge,vector<EdgeEnd*> *l);
protected:
	void createEdgeEndForPrev(Edge *edge,vector<EdgeEnd*> *l,EdgeIntersection *eiCurr,EdgeIntersection *eiPrev);
	void createEdgeEndForNext(Edge *edge,vector<EdgeEnd*> *l,EdgeIntersection *eiCurr,EdgeIntersection *eiNext);
};

/*
 * Contains all EdgeEnd objectss which start at the same point
 * and are parallel.
 */
class EdgeEndBundle: public EdgeEnd {
public:
	EdgeEndBundle(EdgeEnd *e);
	virtual ~EdgeEndBundle();
	Label *getLabel();
//Iterator iterator() //Not needed
	vector<EdgeEnd*>* getEdgeEnds();
	void insert(EdgeEnd *e);
	void computeLabel() ; 
	void updateIM(IntersectionMatrix *im);
	string print();
protected:
	vector<EdgeEnd*> *edgeEnds;
	void computeLabelOn(int geomIndex);
	void computeLabelSides(int geomIndex);
	void computeLabelSide(int geomIndex,int side);
};

/*
 * An ordered list of EdgeEndBundle objects around a RelateNode.
 * They are maintained in CCW order (starting with the positive x-axis)
 * around the node
 * for efficient lookup and topology building.
 */
class EdgeEndBundleStar: public EdgeEndStar {
public:
	EdgeEndBundleStar();
	virtual ~EdgeEndBundleStar();
	void insert(EdgeEnd *e);
	void updateIM(IntersectionMatrix *im);
};

/*
 * Used by the NodeMap in a RelateNodeGraph to create RelateNode objects.
 */
class RelateNodeFactory: public NodeFactory {
public:
	Node* createNode(Coordinate coord);
};

/*
 * Implements the simple graph of Nodes and EdgeEnd which is all that is
 * required to determine topological relationships between Geometries.
 * Also supports building a topological graph of a single Geometry, to
 * allow verification of valid topology.
 * 
 * It is <b>not</b> necessary to create a fully linked
 * PlanarGraph to determine relationships, since it is sufficient
 * to know how the Geometries interact locally around the nodes.
 * In fact, this is not even feasible, since it is not possible to compute
 * exact intersection points, and hence the topology around those nodes
 * cannot be computed robustly.
 * The only Nodes that are created are for improper intersections;
 * that is, nodes which occur at existing vertices of the Geometries.
 * Proper intersections (e.g. ones which occur between the interior of
 * line segments)
 * have their topology determined implicitly, without creating a Node object
 * to represent them.
 *
 */
class RelateNodeGraph {
public:
	RelateNodeGraph();
	virtual ~RelateNodeGraph();
//	Iterator getNodeIterator();
	map<Coordinate,Node*,CoordLT>* getNodeMap();
	void build(GeometryGraph *geomGraph);
	void computeIntersectionNodes(GeometryGraph *geomGraph,int argIndex);
	void copyNodesAndLabels(GeometryGraph *geomGraph,int argIndex);
	void insertEdgeEnds(vector<EdgeEnd*> *ee);
private:
	NodeMap *nodes;
};

/*
 * Computes the topological relationship between two Geometries.
 *
 * RelateComputer does not need to build a complete graph structure to compute
 * the IntersectionMatrix.  The relationship between the geometries can
 * be computed by simply examining the labelling of edges incident on each node.
 * 
 * RelateComputer does not currently support arbitrary GeometryCollections.
 * This is because GeometryCollections can contain overlapping Polygons.
 * In order to correct compute relate on overlapping Polygons, they
 * would first need to be noded and merged (if not explicitly, at least
 * implicitly).
 *
 */
class RelateComputer {
friend class Unload;
public:
	RelateComputer();
	virtual ~RelateComputer();
	RelateComputer(vector<GeometryGraph*> *newArg);
	IntersectionMatrix* computeIM();
private:
	static const LineIntersector* li;
	static const PointLocator* ptLocator;
	vector<GeometryGraph*> *arg;  // the arg(s) of the operation
	NodeMap *nodes;
	// this intersection matrix will hold the results compute for the relate
	IntersectionMatrix *im;
	vector<Edge*> *isolatedEdges;
	// the intersection point found (if any)
	Coordinate invalidPoint;
	void insertEdgeEnds(vector<EdgeEnd*> *ee);
	void computeProperIntersectionIM(SegmentIntersector *intersector,IntersectionMatrix *imX);
	void copyNodesAndLabels(int argIndex);
	void computeIntersectionNodes(int argIndex);
	void labelIntersectionNodes(int argIndex);
	void computeDisjointIM(IntersectionMatrix *imX);
	void labelNodeEdges();
	void updateIM(IntersectionMatrix *imX);
	void labelIsolatedEdges(int thisIndex,int targetIndex);
	void labelIsolatedEdge(Edge *e,int targetIndex, const Geometry *target);
	void labelIsolatedNodes();
	void labelIsolatedNode(Node *n,int targetIndex);
};

/*
 * Implements the relate() operation on Geometry.
 * 
 * WARNING: The current implementation of this class will compute a result for
 * GeometryCollections.  However, the semantics of this operation are
 * not well-defined and the value returned may not represent
 * an appropriate notion of relate.
 */
class RelateOp: public GeometryGraphOperation {
public:
	static IntersectionMatrix* relate(const Geometry *a,const Geometry *b);
	RelateOp(const Geometry *g0, const Geometry *g1);
	virtual ~RelateOp();
	IntersectionMatrix* getIntersectionMatrix();
private:
	RelateComputer relateComp;
};
}

#endif