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

 *

 * GEOS - Geometry Engine Open Source

 * http://geos.osgeo.org

 *

 * Copyright (C) 2020-2021 Daniel Baston

 *

 * 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/operation/cluster/AbstractClusterFinder.h>

#include <geos/geom/Envelope.h>

namespace geos {

namespace operation {

namespace cluster {

/** EnvelopeDistanceClusterFinder clusters geometries by the distance between their envelopes.

 * Any two geometries whose envelopes are within the specified distance will be included in the same cluster.

 */

class GEOS_DLL EnvelopeDistanceClusterFinder : public AbstractClusterFinder {

public:

    explicit EnvelopeDistanceClusterFinder(double d) : m_distance(d), m_distance_squared(d*d) {}

protected:

    const geom::Envelope& queryEnvelope(const geom::Geometry* a) override {

        m_envelope = *a->getEnvelopeInternal();

        m_envelope.expandBy(m_distance);

        return m_envelope;

    }

    bool shouldJoin(const geom::Geometry* a, const geom::Geometry *b) override {

        return a->getEnvelopeInternal()->distanceSquared(*b->getEnvelopeInternal()) <= m_distance_squared;

    }

private:

    geom::Envelope m_envelope;

    double m_distance;

    double m_distance_squared;

};

}

}

}