LineStringSnapper.h

00001 /**********************************************************************
00002  * $Id: LineStringSnapper.h 1940 2006-12-13 10:51:18Z strk $
00003  *
00004  * GEOS - Geometry Engine Open Source
00005  * http://geos.refractions.net
00006  *
00007  * Copyright (C) 2006 Refractions Research Inc.
00008  *
00009  * This is free software; you can redistribute and/or modify it under
00010  * the terms of the GNU Lesser General Public Licence as published
00011  * by the Free Software Foundation. 
00012  * See the COPYING file for more information.
00013  *
00014  ***********************************************************************
00015  *
00016  * Last port: operation/overlay/snap/lineStringSnapper.java rev. 1.1
00017  * (we should move in GEOS too, probably)
00018  *
00019  **********************************************************************/
00020 
00021 #ifndef GEOS_PRECISION_LINESTRINGSNAPPER_H
00022 #define GEOS_PRECISION_LINESTRINGSNAPPER_H
00023 
00024 #include <geos/geom/Coordinate.h>
00025 #include <geos/geom/CoordinateSequence.h>
00026 #include <geos/geom/CoordinateList.h>
00027 
00028 #include <memory>
00029 
00030 // Forward declarations
00031 namespace geos {
00032         namespace geom { 
00033                 //class PrecisionModel;
00034                 //class CoordinateSequence;
00035                 class CoordinateList;
00036                 class Geometry;
00037         }
00038 }
00039 
00040 namespace geos {
00041 namespace precision { // geos.precision
00042 
00048 class LineStringSnapper {
00049 
00050 public:
00051 
00052         LineStringSnapper(const geom::Coordinate::Vect& nSrcPts, double nSnapTol)
00053                 :
00054                 srcPts(nSrcPts),
00055                 snapTolerance(nSnapTol)
00056         {
00057                 size_t s = srcPts.size();
00058                 isClosed = ( s < 2 || srcPts[0].equals2D(srcPts[s-1]) );
00059         }
00060 
00061         // Snap points are assumed to be all distinct points (a set would be better, uh ?)
00062         std::auto_ptr<geom::Coordinate::Vect> snapTo(const geom::Coordinate::ConstVect& snapPts);
00063 
00064 private:
00065 
00066         const geom::Coordinate::Vect& srcPts;
00067 
00068         double snapTolerance;
00069 
00070         bool isClosed;
00071 
00072 
00073         // Modifies first arg
00074         void snapVertices(geom::CoordinateList& srcCoords,
00075                         const geom::Coordinate::ConstVect& snapPts);
00076 
00077 
00078         // Returns snapPts.end() if no snap point is close enough (within snapTol distance)
00079         geom::Coordinate::ConstVect::const_iterator findSnapForVertex(const geom::Coordinate& pt,
00080                         const geom::Coordinate::ConstVect& snapPts);
00081 
00082         // Modifies first arg
00083         void snapSegments(geom::CoordinateList& srcCoords,
00084                         const geom::Coordinate::ConstVect& snapPts);
00085 
00089         //
00107         geom::CoordinateList::iterator findSegmentToSnap(
00108                         const geom::Coordinate& snapPt,
00109                         geom::CoordinateList::iterator from,
00110                         geom::CoordinateList::iterator too_far);
00111 
00112 };
00113 
00114 
00115 } // namespace geos.precision
00116 } // namespace geos
00117 
00118 #endif // GEOS_PRECISION_LINESTRINGSNAPPER_H
00119 
00120 /**********************************************************************
00121  * $Log$
00122  * Revision 1.1  2006/07/21 17:09:14  strk
00123  * Added new precision::LineStringSnapper class + test
00124  * and precision::GeometrySnapper (w/out test)
00125  *
00126  **********************************************************************/

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