88 lines
2.4 KiB
C++
88 lines
2.4 KiB
C++
/**********************************************************************
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*
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* GEOS - Geometry Engine Open Source
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* http://geos.osgeo.org
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*
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* Copyright (C) 2009 Sandro Santilli <strk@kbt.io>
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* Copyright (C) 2006 Refractions Research Inc.
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* Copyright (C) 2001-2002 Vivid Solutions Inc.
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*
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* This is free software; you can redistribute and/or modify it under
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* the terms of the GNU Lesser General Public Licence as published
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* by the Free Software Foundation.
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* See the COPYING file for more information.
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*
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**********************************************************************
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*
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* Last port: index/quadtree/Key.java rev 1.8 (JTS-1.10)
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*
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**********************************************************************/
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#pragma once
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#include <geos/export.h>
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#include <geos/geom/Coordinate.h> // for composition
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#include <geos/geom/Envelope.h> // for composition
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// Forward declarations
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// ...
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namespace geos {
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namespace index { // geos::index
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namespace quadtree { // geos::index::quadtree
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/**
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* \brief
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* A Key is a unique identifier for a node in a quadtree.
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*
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* It contains a lower-left point and a level number. The level number
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* is the power of two for the size of the node envelope
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*/
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class GEOS_DLL Key {
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public:
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// Doesn't touch the Envelope, might as well be const
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static int computeQuadLevel(const geom::Envelope& env);
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// Reference to argument won't be used after construction
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Key(const geom::Envelope& itemEnv);
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// used to be virtual, but I don't see subclasses...
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~Key() = default;
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/// Returned object ownership retained by this class
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const geom::Coordinate& getPoint() const;
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int getLevel() const;
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/// Returned object ownership retained by this class
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const geom::Envelope& getEnvelope() const;
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/// Returns newly allocated object (ownership transferred)
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geom::Coordinate* getCentre() const;
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/**
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* return a square envelope containing the argument envelope,
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* whose extent is a power of two and which is based at a power of 2
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*/
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void computeKey(const geom::Envelope& itemEnv);
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private:
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// the fields which make up the key
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// Owned by this class
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geom::Coordinate pt;
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int level;
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// auxiliary data which is derived from the key for use in computation
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geom::Envelope env;
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void computeKey(int level, const geom::Envelope& itemEnv);
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};
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} // namespace geos::index::quadtree
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} // namespace geos::index
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} // namespace geos
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