oppolygonize.h

一个很好的vc代码

/**********************************************************************
 * $Id: opPolygonize.h,v 1.7.2.1 2005/05/23 17:23:15 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.
 *
 **********************************************************************/


#ifndef GEOS_OPPOLYGONIZE_H
#define GEOS_OPPOLYGONIZE_H

#include <geos/platform.h>
#include <geos/planargraph.h>
#include <geos/geosAlgorithm.h>
#include <geos/geom.h>
#include <vector>

namespace geos {

//using namespace planargraph;

/*
 * An edge of a polygonization graph.
 *
 * @version 1.4
 */
class PolygonizeEdge: public planarEdge {
private:
	const LineString *line;
public:
	PolygonizeEdge(const LineString *newLine);
	const LineString* getLine();
};


/*
 * Represents a ring of PolygonizeDirectedEdge which form
 * a ring of a polygon.  The ring may be either an outer shell or a hole.
 */
class polygonizeEdgeRing {
private:
	const GeometryFactory *factory;
	static CGAlgorithms cga;
	vector<const planarDirectedEdge*> *deList;

	// cache the following data for efficiency
	LinearRing *ring;
	CoordinateSequence *ringPts;
	vector<Geometry*> *holes;

	/*
	 * Computes the list of coordinates which are contained in this ring.
	 * The coordinatea are computed once only and cached.
	 *
	 * @return an array of the Coordinate in this ring
	 */
	CoordinateSequence* getCoordinates();

	static void addEdge(const CoordinateSequence *coords, bool isForward, CoordinateSequence *coordList);

public:
	/**
	 * Find the innermost enclosing shell polygonizeEdgeRing
	 * containing the argument polygonizeEdgeRing, if any.
	 * The innermost enclosing ring is the <i>smallest</i> enclosing ring.
	 * The algorithm used depends on the fact that:
	 * 
	 * ring A contains ring B iff envelope(ring A) contains envelope(ring B)
	 *
	 * This routine is only safe to use if the chosen point of the hole
	 * is known to be properly contained in a shell
	 * (which is guaranteed to be the case if the hole does not touch
	 * its shell)
	 *
	 * @return containing polygonizeEdgeRing, if there is one
	 * @return null if no containing polygonizeEdgeRing is found
	 */
	static polygonizeEdgeRing* findEdgeRingContaining(polygonizeEdgeRing *testEr, vector<polygonizeEdgeRing*> *shellList);

	/*
	 * \brief
	 * Finds a point in a list of points which is not contained in
	 * another list of points.
	 *
	 * @param testPts the CoordinateSequence to test
	 * @param pts the CoordinateSequence to test the input points against
	 * @return a Coordinate reference from <code>testPts</code> which is
	 * not in <code>pts</code>, or <code>Coordinate::nullCoord</code>
	 */
	static const Coordinate& ptNotInList(const CoordinateSequence *testPts, const CoordinateSequence *pts);

	/*
	 * Tests whether a given point is in an array of points.
	 * Uses a value-based test.
	 *
	 * @param pt a Coordinate for the test point
	 * @param pts an array of Coordinate to test
	 * @return <code>true</code> if the point is in the array
	 */
	static bool isInList(const Coordinate &pt, const CoordinateSequence *pts);
	polygonizeEdgeRing(const GeometryFactory *newFactory);
	~polygonizeEdgeRing();

	/*
	 * Adds a DirectedEdge which is known to form part of this ring.
	 * @param de the DirectedEdge to add. Ownership to the caller.
	 */
	void add(const planarDirectedEdge *de);

	/*
	 * Tests whether this ring is a hole.
	 * Due to the way the edges in the polyongization graph are linked,
	 * a ring is a hole if it is oriented counter-clockwise.
	 * @return <code>true</code> if this ring is a hole
	 */
	bool isHole();

	/*
	 * Adds a hole to the polygon formed by this ring.
	 * @param hole the LinearRing forming the hole.
	 */
	void addHole(LinearRing *hole);

	/*
	 * Computes the Polygon formed by this ring and any contained holes.
	 *
	 * @return the Polygon formed by this ring and its holes.
	 */
	Polygon* getPolygon();

	/*
	 * Tests if the LinearRing ring formed by this edge ring
	 * is topologically valid.
	 */
	bool isValid();

	/*
	 * Gets the coordinates for this ring as a LineString.
	 * Used to return the coordinates in this ring
	 * as a valid geometry, when it has been detected that the ring
	 * is topologically invalid.
	 * @return a LineString containing the coordinates in this ring
	 */
	LineString* getLineString();

	/*
	 * Returns this ring as a LinearRing, or null if an Exception
	 * occurs while creating it (such as a topology problem).
	 * Ownership of ring is retained by the object.
	 * Details of problems are written to standard output.
	 */
	LinearRing* getRingInternal();

	/*
	 * Returns this ring as a LinearRing taking ownership
	 * of it. 
	 */
	LinearRing* getRingOwnership();
};


/*
 * A DirectedEdge of a PolygonizeGraph, which represents
 * an edge of a polygon formed by the graph.
 * May be logically deleted from the graph by setting the
 * <code>marked</code> flag.
 */
class PolygonizeDirectedEdge: public planarDirectedEdge {
private:
	polygonizeEdgeRing *edgeRing;
	PolygonizeDirectedEdge *next;
	long label;
public:
	/*
	 * \brief
	 * Constructs a directed edge connecting the <code>from</code> node
	 * to the <code>to</code> node.
	 *
	 * @param directionPt
	 *    specifies this DirectedEdge's direction (given by an imaginary
	 *    line from the <code>from</code> node to <code>directionPt</code>)
	 *
	 * @param edgeDirection
	 *    whether this DirectedEdge's direction is the same as or
	 *    opposite to that of the parent Edge (if any)
	 */
	PolygonizeDirectedEdge(planarNode *newFrom,planarNode *newTo, const Coordinate& newDirectionPt,bool nEdgeDirection);

	/*
	 * Returns the identifier attached to this directed edge.
	 */
	long getLabel() const;

	/*
	 * Attaches an identifier to this directed edge.
	 */
	void setLabel(long newLabel);

	/*
	 * Returns the next directed edge in the EdgeRing that this
	 * directed edge is a member of.
	 */
	PolygonizeDirectedEdge* getNext() const;

	/*
	 * Sets the next directed edge in the EdgeRing that this
	 * directed edge is a member of.
	 */
	void setNext(PolygonizeDirectedEdge *newNext);

	/*
	 * Returns the ring of directed edges that this directed edge is
	 * a member of, or null if the ring has not been set.
	 * @see #setRing(EdgeRing)
	 */
	bool isInRing() const;

	/*
	 * Sets the ring of directed edges that this directed edge is
	 * a member of.
	 */
	void setRing(polygonizeEdgeRing *newEdgeRing);
};


/*
 * 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 PolygonizeGraph: public planarPlanarGraph {
public:
	/*
	 * \brief
	 * Deletes all edges at a node
	 */
	static void deleteAllEdges(planarNode *node);

	/*
	 * \brief
	 * Create a new polygonization graph.
	 */
	PolygonizeGraph(const GeometryFactory *newFactory);

	/*
	 * \brief
	 * Destroy a polygonization graph.
	 */
	~PolygonizeGraph();

	/*
	 * \brief
	 * Add a LineString forming an edge of the polygon graph.
	 * @param line the line to add
	 */
	void addEdge(const LineString *line);