source/algorithm/InteriorPointLine.cpp

   1 /**********************************************************************
   2  * $Id$
   3  *
   4  * GEOS - Geometry Engine Open Source
   5  * http://geos.refractions.net
   6  *
   7  * Copyright (C) 2005-2006 Refractions Research Inc.
   8  * Copyright (C) 2001-2002 Vivid Solutions Inc.
   9  *
  10  * This is free software; you can redistribute and/or modify it under
  11  * the terms of the GNU Lesser General Public Licence as published
  12  * by the Free Software Foundation.
  13  * See the COPYING file for more information.
  14  *
  15  **********************************************************************
  16  *
  17  **********************************************************************/
  18
  19 #include <geos/algorithm/InteriorPointLine.h>
  20 #include <geos/geom/Coordinate.h>
  21 #include <geos/geom/Geometry.h>
  22 #include <geos/geom/GeometryCollection.h>
  23 #include <geos/geom/LineString.h>
  24 #include <geos/geom/CoordinateSequence.h>
  25
  26 #ifndef GEOS_DEBUG
  27 #define GEOS_DEBUG 0
  28 #endif
  29
  30 #ifdef GEOS_DEBUG
  31 #include <iostream>
  32 #endif
  33
  34 using namespace geos::geom;
  35
  36 namespace geos {
  37 namespace algorithm { // geos.algorithm
  38
  39 InteriorPointLine::InteriorPointLine(const Geometry *g)
  40 {
  41         minDistance=DoubleInfinity;
  42         hasInterior=false;
  43         if ( g->getCentroid(centroid) )
  44         {
  45 #if GEOS_DEBUG
  46                 std::cerr << "Centroid: " << centroid << std::endl;
  47 #endif
  48                 addInterior(g);
  49                 if (!hasInterior) addEndpoints(g);
  50         }
  51 }
  52
  53 InteriorPointLine::~InteriorPointLine()
  54 {
  55 }
  56
  57 /* private
  58  *
  59  * Tests the interior vertices (if any)
  60  * defined by a linear Geometry for the best inside point.
  61  * If a Geometry is not of dimension 1 it is not tested.
  62  * @param geom the geometry to add
  63  */
  64 void
  65 InteriorPointLine::addInterior(const Geometry *geom)
  66 {
  67         const LineString *ls = dynamic_cast<const LineString*>(geom);
  68         if ( ls ) {
  69                 addInterior(ls->getCoordinatesRO());
  70                 return;
  71         }
  72
  73         const GeometryCollection *gc = dynamic_cast<const GeometryCollection*>(geom);
  74         if ( gc )
  75         {
  76                 for(std::size_t i=0, n=gc->getNumGeometries(); i<n; i++) {
  77                         addInterior(gc->getGeometryN(i));
  78                 }
  79         }
  80 }
  81
  82 void
  83 InteriorPointLine::addInterior(const CoordinateSequence *pts)
  84 {
  85         const std::size_t n=pts->getSize()-1;
  86         for(std::size_t i=1; i<n; ++i)
  87         {
  88                 add(pts->getAt(i));
  89         }
  90 }
  91
  92 /* private
  93  *
  94  * Tests the endpoint vertices
  95  * defined by a linear Geometry for the best inside point.
  96  * If a Geometry is not of dimension 1 it is not tested.
  97  * @param geom the geometry to add
  98  */
  99 void
 100 InteriorPointLine::addEndpoints(const Geometry *geom)
 101 {
 102         const LineString *ls = dynamic_cast<const LineString*>(geom);
 103         if ( ls ) {
 104                 addEndpoints(ls->getCoordinatesRO());
 105                 return;
 106         }
 107
 108         const GeometryCollection *gc = dynamic_cast<const GeometryCollection*>(geom);
 109         if ( gc )
 110         {
 111                 for(std::size_t i=0, n=gc->getNumGeometries(); i<n; i++) {
 112                         addEndpoints(gc->getGeometryN(i));
 113                 }
 114         }
 115 }
 116
 117 void
 118 InteriorPointLine::addEndpoints(const CoordinateSequence *pts)
 119 {
 120         add(pts->getAt(0));
 121         add(pts->getAt(pts->getSize()-1));
 122 }
 123
 124 /*private*/
 125 void
 126 InteriorPointLine::add(const Coordinate& point)
 127 {
 128
 129         double dist=point.distance(centroid);
 130 #if GEOS_DEBUG
 131         std::cerr << "point " << point << " dist " << dist << ", minDistance " << minDistance << std::endl;
 132 #endif
 133         if (!hasInterior || dist<minDistance) {
 134                 interiorPoint=point;
 135 #if GEOS_DEBUG
 136                 std::cerr << " is new InteriorPoint" << std::endl;
 137 #endif
 138                 minDistance=dist;
 139                 hasInterior=true;
 140         }
 141 }
 142
 143 bool
 144 InteriorPointLine::getInteriorPoint(Coordinate& ret) const
 145 {
 146         if ( ! hasInterior ) return false;
 147         ret=interiorPoint;
 148         return true;
 149 }
 150
 151 } // namespace geos.algorithm
 152 } // namespace geos
 153
 154 /**********************************************************************
 155  * $Log$
 156  * Revision 1.18  2006/03/21 11:12:23  strk
 157  * Cleanups: headers inclusion and Log section
 158  *
 159  * Revision 1.17  2006/03/09 16:46:45  strk
 160  * geos::geom namespace definition, first pass at headers split
 161  **********************************************************************/
 162