LineStringSnapper.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2009-2010  Sandro Santilli <strk@keybit.net>
 * Copyright (C) 2006 Refractions Research Inc.
 *
 * 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/overlay/snap/LineStringSnapper.java r320 (JTS-1.12)
 *
 **********************************************************************/
 
#ifndef GEOS_OP_OVERLAY_SNAP_LINESTRINGSNAPPER_H
#define GEOS_OP_OVERLAY_SNAP_LINESTRINGSNAPPER_H
 
#include <geos/geom/Coordinate.h>
#include <geos/geom/CoordinateSequence.h>
#include <geos/geom/CoordinateList.h>
 
#include <memory>
 
// Forward declarations
namespace geos {
        namespace geom {
                //class PrecisionModel;
                //class CoordinateSequence;
                class CoordinateList;
                class Geometry;
        }
}
 
namespace geos {
namespace operation { // geos::operation
namespace overlay { // geos::operation::overlay
namespace snap { // geos::operation::overlay::snap

class GEOS_DLL LineStringSnapper {
 
public:

        LineStringSnapper(const geom::Coordinate::Vect& nSrcPts,
                                                  double nSnapTol)
                :
                srcPts(nSrcPts),
                snapTolerance(nSnapTol),
                allowSnappingToSourceVertices(false)
        {
                size_t s = srcPts.size();
                isClosed = s < 2 ? false : srcPts[0].equals2D(srcPts[s-1]);
        }
 
        // Snap points are assumed to be all distinct points (a set would be better, uh ?)
        std::auto_ptr<geom::Coordinate::Vect> snapTo(const geom::Coordinate::ConstVect& snapPts);
 
        void setAllowSnappingToSourceVertices(bool allow) {
                allowSnappingToSourceVertices = allow;
        }
 
private:
 
        const geom::Coordinate::Vect& srcPts;
 
        double snapTolerance;
 
        bool allowSnappingToSourceVertices;
        bool isClosed;
 
 
        // Modifies first arg
        void snapVertices(geom::CoordinateList& srcCoords,
                        const geom::Coordinate::ConstVect& snapPts);
 
 
        // Returns snapPts.end() if no snap point is close enough (within snapTol distance)
        geom::Coordinate::ConstVect::const_iterator findSnapForVertex(const geom::Coordinate& pt,
                        const geom::Coordinate::ConstVect& snapPts);

  void snapSegments(geom::CoordinateList& srcCoords,
                    const geom::Coordinate::ConstVect& snapPts);

        //
        geom::CoordinateList::iterator findSegmentToSnap(
                        const geom::Coordinate& snapPt,
                        geom::CoordinateList::iterator from,
                        geom::CoordinateList::iterator too_far);
 
        geom::CoordinateList::iterator findVertexToSnap(
                        const geom::Coordinate& snapPt,
                        geom::CoordinateList::iterator from,
                        geom::CoordinateList::iterator too_far);
 
    // Declare type as noncopyable
    LineStringSnapper(const LineStringSnapper& other);
    LineStringSnapper& operator=(const LineStringSnapper& rhs);
};
 
 
} // namespace geos::operation::overlay::snap
} // namespace geos::operation::overlay
} // namespace geos::operation
} // namespace geos
 
#endif // GEOS_OP_OVERLAY_SNAP_LINESTRINGSNAPPER_H