/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 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_IDX_BINTREE_KEY_H
#define GEOS_IDX_BINTREE_KEY_H

#include <geos/export.h>

// Forward declarations
namespace geos {
	namespace index { 
		namespace bintree { 
			class Interval;
		}
	}
}

namespace geos {
namespace index { // geos::index
namespace bintree { // geos::index::bintree

/** \brief
 * A Key is a unique identifier for a node in a tree.
 *
 * It contains a lower-left point and a level number.
 * The level number is the power of two for the size of the node envelope
 */
class GEOS_DLL Key {

public:

	static int computeLevel(Interval *newInterval);

	Key(Interval *newInterval);

	~Key();

	double getPoint();

	int getLevel();

	Interval* getInterval();

	void computeKey(Interval *itemInterval);

private:

	// the fields which make up the key
	double pt;
	int level;

	// auxiliary data which is derived from the key for use in computation
	Interval *interval;

	void computeInterval(int level, Interval *itemInterval);
};

} // namespace geos::index::bintree
} // namespace geos::index
} // namespace geos

#endif // GEOS_IDX_BINTREE_KEY_H

