OffsetSegmentGenerator.h

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/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2011  Sandro Santilli <strk@kbt.io>
 *
 * 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.
 *
 **********************************************************************
 *
 * Last port: operation/buffer/OffsetSegmentGenerator.java r378 (JTS-1.12)
 *
 **********************************************************************/

#ifndef GEOS_OP_BUFFER_OFFSETSEGMENTGENERATOR_H
#define GEOS_OP_BUFFER_OFFSETSEGMENTGENERATOR_H

#include <geos/export.h>

#include <vector>

#include <geos/algorithm/LineIntersector.h> // for composition
#include <geos/geom/Coordinate.h> // for composition
#include <geos/geom/LineSegment.h> // for composition
#include <geos/operation/buffer/BufferParameters.h> // for composition
#include <geos/operation/buffer/OffsetSegmentString.h> // for composition

#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class
#endif

// Forward declarations
namespace geos {
namespace geom {
class CoordinateSequence;
class PrecisionModel;
}
}

namespace geos {
namespace operation { // geos.operation
namespace buffer { // geos.operation.buffer

class GEOS_DLL OffsetSegmentGenerator {

public:

    /*
     * @param nBufParams buffer parameters, this object will
     *                   keep a reference to the passed parameters
     *                   so caller must make sure the object is
     *                   kept alive for the whole lifetime of
     *                   the buffer builder.
     */
    OffsetSegmentGenerator(const geom::PrecisionModel* newPrecisionModel,
                           const BufferParameters& bufParams, double distance);

    bool
    hasNarrowConcaveAngle() const
    {
        return _hasNarrowConcaveAngle;
    }

    void initSideSegments(const geom::Coordinate& nS1,
                          const geom::Coordinate& nS2, int nSide);

    void
    getCoordinates(std::vector<geom::CoordinateSequence*>& to)
    {
        to.push_back(segList.getCoordinates());
    }

    void
    closeRing()
    {
        segList.closeRing();
    }

    void createCircle(const geom::Coordinate& p, double distance);

    void createSquare(const geom::Coordinate& p, double distance);

    void
    addFirstSegment()
    {
        segList.addPt(offset1.p0);
    }

    void
    addLastSegment()
    {
        segList.addPt(offset1.p1);
    }

    void addNextSegment(const geom::Coordinate& p, bool addStartPoint);

    void addLineEndCap(const geom::Coordinate& p0,
                       const geom::Coordinate& p1);

    void
    addSegments(const geom::CoordinateSequence& pts, bool isForward)
    {
        segList.addPts(pts, isForward);
    }

private:

    static const double OFFSET_SEGMENT_SEPARATION_FACTOR; // 1.0E-3;

    static const double INSIDE_TURN_VERTEX_SNAP_DISTANCE_FACTOR; // 1.0E-3;

    static const double CURVE_VERTEX_SNAP_DISTANCE_FACTOR; //  1.0E-6;

    static const int MAX_CLOSING_SEG_LEN_FACTOR = 80;

    double maxCurveSegmentError; // 0.0

    double filletAngleQuantum;

    int closingSegLengthFactor; // 1;

    OffsetSegmentString segList;

    double distance;

    const geom::PrecisionModel* precisionModel;

    const BufferParameters& bufParams;

    algorithm::LineIntersector li;

    geom::Coordinate s0, s1, s2;

    geom::LineSegment seg0;

    geom::LineSegment seg1;

    geom::LineSegment offset0;

    geom::LineSegment offset1;

    int side;

    bool _hasNarrowConcaveAngle; // =false

    void addCollinear(bool addStartPoint);

    void addMitreJoin(const geom::Coordinate& p,
                      const geom::LineSegment& offset0,
                      const geom::LineSegment& offset1,
                      double distance);

    void addLimitedMitreJoin(
        const geom::LineSegment& offset0,
        const geom::LineSegment& offset1,
        double distance, double mitreLimit);

    void addBevelJoin(const geom::LineSegment& offset0,
                      const geom::LineSegment& offset1);

    static const double PI; //  3.14159265358979

    // Not in JTS, used for single-sided buffers
    int endCapIndex;

    void init(double newDistance);

    static const double SIMPLIFY_FACTOR; // 100.0;

    void addOutsideTurn(int orientation, bool addStartPoint);

    void addInsideTurn(int orientation, bool addStartPoint);

    void computeOffsetSegment(const geom::LineSegment& seg,
                              int side, double distance,
                              geom::LineSegment& offset);

    void addDirectedFillet(const geom::Coordinate& p, const geom::Coordinate& p0,
                   const geom::Coordinate& p1,
                   int direction, double radius);

    void addDirectedFillet(const geom::Coordinate& p, double startAngle,
                   double endAngle, int direction, double radius);
private:
    // An OffsetSegmentGenerator cannot be copied because of member "const BufferParameters& bufParams"
    // Not declaring these functions triggers MSVC warning C4512: "assignment operator could not be generated"
    OffsetSegmentGenerator(const OffsetSegmentGenerator&);
    void operator=(const OffsetSegmentGenerator&);

};

} // namespace geos::operation::buffer
} // namespace geos::operation
} // namespace geos

#ifdef _MSC_VER
#pragma warning(pop)
#endif

#endif // ndef GEOS_OP_BUFFER_OFFSETSEGMENTGENERATOR_H