node.h

在Linux下做的QuadTree的程序

/**********************************************************************
 * $Id: Node.h 1820 2006-09-06 16:54:23Z mloskot $
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.refractions.net
 *
 * Copyright (C) 2001-2002 Vivid Solutions Inc.
 * Copyright (C) 2005-2006 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.
 *
 **********************************************************************/

#ifndef GEOS_PLANARGRAPH_NODE_H
#define GEOS_PLANARGRAPH_NODE_H

#include <geos/planargraph/GraphComponent.h> // for inheritance
#include <geos/planargraph/DirectedEdgeStar.h> // for inlines
#include <geos/geom/Coordinate.h> // for composition

// Forward declarations
namespace geos {
	namespace planargraph { 
		//class DirectedEdgeStar;
		class DirectedEdge;
	}
}

namespace geos {
namespace planargraph { // geos.planargraph

/**
 * \brief A node in a PlanarGraph is a location where 0 or more Edge meet.
 *
 * A node is connected to each of its incident Edges via an outgoing
 * DirectedEdge. Some clients using a <code>PlanarGraph</code> may want to
 * subclass <code>Node</code> to add their own application-specific
 * data and methods.
 *
 */
class Node: public GraphComponent {
protected:

	/// The location of this Node 
	geom::Coordinate pt;

	/// The collection of DirectedEdges that leave this Node 
	DirectedEdgeStar *deStar;

public:

	friend std::ostream& operator << (std::ostream& os, const Node&);

	/** \brief
	 * Returns all Edges that connect the two nodes (which are
	 * assumed to be different).
	 *
	 * Note: returned vector is newly allocated, ownership to 
	 * the caller.
	 */
	static std::vector<Edge*>* getEdgesBetween(Node *node0,
			Node *node1);

	/// Constructs a Node with the given location.
	Node(const geom::Coordinate& newPt)
		:
		pt(newPt)
		{ deStar=new DirectedEdgeStar(); }

	virtual ~Node() {
		delete deStar;
	}

	/**
	 * \brief
	 * Constructs a Node with the given location and
	 * collection of outgoing DirectedEdges.
	 * Takes ownership of the given DirectedEdgeStar!!
	 */
	Node(geom::Coordinate& newPt, DirectedEdgeStar *newDeStar)
		:
		pt(newPt),
		deStar(newDeStar)
		{}

	/**
	 * \brief Returns the location of this Node.
	 */
	geom::Coordinate& getCoordinate() {
		return pt;
	}

	/**
	 * \brief Adds an outgoing DirectedEdge to this Node.
	 */
	void addOutEdge(DirectedEdge *de) {
		deStar->add(de);
	}

	/**
	 * \brief Returns the collection of DirectedEdges that
	 * leave this Node.
	 */
	DirectedEdgeStar* getOutEdges() { return deStar; }
	const DirectedEdgeStar* getOutEdges() const { return deStar; }

	/**
	 * \brief Returns the number of edges around this Node.
	 */
	size_t getDegree() const {
		return deStar->getDegree();
	}

	/**
	 * \brief Returns the zero-based index of the given Edge,
	 * after sorting in ascending order by angle with
	 * the positive x-axis.
	 */
	int getIndex(Edge *edge) {
		return deStar->getIndex(edge);
	}

};

/// Print a Node
std::ostream& operator<<(std::ostream& os, const Node& n); 


/// For backward compatibility
//typedef Node planarNode;

} // namespace geos::planargraph
} // namespace geos

#endif // GEOS_PLANARGRAPH_NODE_H

/**********************************************************************
 * $Log$
 * Revision 1.3  2006/06/12 16:57:26  strk
 * Added note about ownership of return from getEdgesBetween()
 *
 * Revision 1.2  2006/06/12 10:49:43  strk
 * unsigned int => size_t
 *
 * Revision 1.1  2006/03/21 21:42:54  strk
 * planargraph.h header split, planargraph:: classes renamed to match JTS symbols
 *
 **********************************************************************/