HilbertCode.h

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/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2020 Paul Ramsey <pramsey@cleverelephant.ca>
 *
 * 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.
 *
 **********************************************************************/


#pragma once

#include <geos/export.h>
#include <string>

// Forward declarations
namespace geos {
namespace geom {
class Coordinate;
}
}

namespace geos {
namespace shape {   // geos.shape
namespace fractal { // geos.shape.fractal

class GEOS_DLL HilbertCode {

public:

    static constexpr int MAX_LEVEL = 16;

    static geom::Coordinate decode(uint32_t level, uint32_t i);

    static uint32_t encode(uint32_t level, uint32_t x, uint32_t y);

    static uint32_t levelSize(uint32_t level);

    static uint32_t maxOrdinate(uint32_t level);

    static uint32_t level(uint32_t numPoints);


private:

    static uint32_t deinterleave(uint32_t x);

    static uint32_t interleave(uint32_t x);

    static uint32_t prefixScan(uint32_t x);

    static uint32_t descan(uint32_t x);

    static void checkLevel(int level);


};


} // namespace geos.shape.fractal
} // namespace geos.shape
} // namespace geos