/**********************************************************************

 *

 * 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.

 *

 **********************************************************************/

#include <geos/shape/fractal/HilbertEncoder.h>

#include <geos/shape/fractal/HilbertCode.h>

#include <geos/geom/Coordinate.h>

#include <geos/geom/Envelope.h>

#include <geos/geom/Geometry.h>

#include <cstdint>

#include <vector>

namespace geos {

namespace shape {   // geos.shape

namespace fractal { // geos.shape.fractal

HilbertEncoder::HilbertEncoder(uint32_t p_level, geom::Envelope& extent)

    : level(p_level)

{

    int hside = (int)std::pow(2, level) - 1;

    minx = extent.getMinX();

    strideX = extent.getWidth() / hside;

    miny = extent.getMinY();

    strideY = extent.getHeight() / hside;

}

uint32_t

HilbertEncoder::encode(const geom::Envelope* env)

{

    double midx = env->getWidth()/2 + env->getMinX();

    uint32_t x = 0;

    if (midx > minx && strideX != 0)

        x = (uint32_t) ((midx - minx) / strideX);

    double midy = env->getHeight()/2 + env->getMinY();

    uint32_t y = 0;

    if (midy > miny && strideY != 0)

        y = (uint32_t) ((midy - miny) / strideY);

    return HilbertCode::encode(level, x, y);

}

/* public static */

void

HilbertEncoder::sort(std::vector<geom::Geometry*>& geoms)

{

    sort(geoms.begin(), geoms.end());

}

} // namespace geos.shape.fractal

} // namespace geos.shape

} // namespace geos