LineLimiter.h

/**********************************************************************
 *
 * 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/geom/CoordinateSequence.h>
 
#include <geos/export.h>
#include <array>
#include <memory>
#include <vector>
 
// Forward declarations
namespace geos {
namespace geom {
class Envelope;
class Coordinate;
class CoordinateSequence;
}
}
 
namespace geos {      // geos.
namespace operation { // geos.operation
namespace overlayng { // geos.operation.overlayng
 
class GEOS_DLL LineLimiter {
    using Envelope = geos::geom::Envelope;
    using Coordinate = geos::geom::Coordinate;
    using CoordinateXY = geos::geom::CoordinateXY;
    using CoordinateSequence = geos::geom::CoordinateSequence;
 
private:
 
    // Members
    const Envelope* limitEnv;
    std::unique_ptr<geom::CoordinateSequence> ptList;
    const CoordinateXY* lastOutside;
    std::vector<std::unique_ptr<CoordinateSequence>> sections;
    bool hasZ{false};
    bool hasM{false};
 
    // Methods
    template<typename CoordType>
    void addPoint(const CoordType& p);
 
    template<typename CoordType>
    void addOutside(const CoordType& p);
    bool isLastSegmentIntersecting(const CoordinateXY& p) const;
    bool isSectionOpen() const;
 
    template<typename CoordType>
    void startSection();
    void finishSection();
 
 
public:
 
    LineLimiter(const Envelope* env)
        : limitEnv(env)
        , ptList(nullptr)
        , lastOutside(nullptr)
        {};
 
    std::vector<std::unique_ptr<CoordinateSequence>>& limit(const CoordinateSequence *pts);
 
};
 
 
} // namespace geos.operation.overlayng
} // namespace geos.operation
} // namespace geos