OffsetSegmentGenerator.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2011  Sandro Santilli <strk@keybit.net>
 *
 * 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 addFillet(const geom::Coordinate &p, const geom::Coordinate &p0,
                 const geom::Coordinate &p1,
                 int direction, double radius);

  void addFillet(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