/**********************************************************************
 * $Id: DirectedEdgeStar.h 2556 2009-06-06 22:22:28Z strk $
 *
 * 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_DIRECTEDEDGESTAR_H
#define GEOS_PLANARGRAPH_DIRECTEDEDGESTAR_H

#include <geos/export.h>

#include <vector>

// Forward declarations
namespace geos {
	namespace geom {
		class Coordinate;
	}
	namespace planargraph {
		class DirectedEdge;
		class Edge;
	}
}

namespace geos {
namespace planargraph { // geos.planargraph

/// A sorted collection of DirectedEdge which leave a Node in a PlanarGraph.
class GEOS_DLL DirectedEdgeStar {
protected:

private:
	/**
	 * \brief The underlying list of outgoing DirectedEdges
	 */
	mutable std::vector<DirectedEdge*> outEdges;
	mutable bool sorted;
	void sortEdges() const;

public:
	/**
	 * \brief Constructs a DirectedEdgeStar with no edges.
	 */
	DirectedEdgeStar(): sorted(false) {}

	virtual ~DirectedEdgeStar() {}

	/**
	 * \brief Adds a new member to this DirectedEdgeStar.
	 */
	void add(DirectedEdge *de);

	/**
	 * \brief Drops a member of this DirectedEdgeStar.
	 */
	void remove(DirectedEdge *de);

	/**
	 * \brief Returns an Iterator over the DirectedEdges,
	 * in ascending order by angle with the positive x-axis.
	 */
	std::vector<DirectedEdge*>::iterator iterator() { return begin(); }
	/// Returns an iterator to first DirectedEdge
	std::vector<DirectedEdge*>::iterator begin();

	/// Returns an iterator to one-past last DirectedEdge
	std::vector<DirectedEdge*>::iterator end();

	/// Returns an const_iterator to first DirectedEdge
	std::vector<DirectedEdge*>::const_iterator begin() const;

	/// Returns an const_iterator to one-past last DirectedEdge
	std::vector<DirectedEdge*>::const_iterator end() const;

	/**
	 * \brief Returns the number of edges around the Node associated
	 * with this DirectedEdgeStar.
	 */
	size_t getDegree() const { return outEdges.size(); }

	/**
	 * \brief Returns the coordinate for the node at wich this
	 * star is based
	 */
	geom::Coordinate& getCoordinate() const;

	/**
	 * \brief Returns the DirectedEdges, in ascending order
	 * by angle with the positive x-axis.
	 */
	std::vector<DirectedEdge*>& getEdges();

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

	/**
	 * \brief Returns the zero-based index of the given DirectedEdge,
	 * after sorting in ascending order
	 * by angle with the positive x-axis.
	 */  
	int getIndex(const DirectedEdge *dirEdge);

	/**
	 * \brief Returns the remainder when i is divided by the number of
	 * edges in this DirectedEdgeStar. 
	 */
	int getIndex(int i) const;

	/**
	 * \brief Returns the DirectedEdge on the left-hand side
	 * of the given DirectedEdge (which must be a member of this
	 * DirectedEdgeStar). 
	 */
	DirectedEdge* getNextEdge(DirectedEdge *dirEdge);
};


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

#endif // GEOS_PLANARGRAPH_DIRECTEDEDGESTAR_H

/**********************************************************************
 * $Log$
 * 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
 *
 **********************************************************************/

