src/linearref/LengthIndexedLine.cpp

   1 /**********************************************************************
   2  *
   3  * GEOS - Geometry Engine Open Source
   4  * http://geos.osgeo.org
   5  *
   6  * Copyright (C) 2011 Sandro Santilli <strk@keybit.net>
   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  * Last port: linearref/LengthIndexedLine.java r463
  18  *
  19  **********************************************************************/
  20
  21 #include <geos/linearref/ExtractLineByLocation.h>
  22 #include <geos/linearref/LengthIndexedLine.h>
  23 #include <geos/linearref/LocationIndexedLine.h>
  24 #include <geos/linearref/LinearLocation.h>
  25 #include <geos/linearref/LengthLocationMap.h>
  26 #include <geos/linearref/LengthIndexOfPoint.h>
  27 #include <geos/linearref/LocationIndexOfLine.h>
  28
  29 using namespace std;
  30
  31 using namespace geos::geom;
  32
  33 namespace geos
  34 {
  35 namespace linearref   // geos.linearref
  36 {
  37
  38 LengthIndexedLine::LengthIndexedLine(const Geometry* linearGeom) :
  39                 linearGeom(linearGeom) {}
  40
  41 Coordinate LengthIndexedLine::extractPoint(double index) const
  42 {
  43         LinearLocation loc = LengthLocationMap::getLocation(linearGeom, index);
  44         Coordinate coord = loc.getCoordinate(linearGeom);
  45         return coord;
  46 }
  47
  48 Coordinate LengthIndexedLine::extractPoint(double index, double offsetDistance) const
  49 {
  50         LinearLocation loc = LengthLocationMap::getLocation(linearGeom, index);
  51         Coordinate ret;
  52         loc.getSegment(linearGeom)->pointAlongOffset(loc.getSegmentFraction(), offsetDistance, ret);
  53         return ret;
  54 }
  55
  56
  57 Geometry *
  58 LengthIndexedLine::extractLine(double startIndex, double endIndex) const
  59 {
  60   const LocationIndexedLine lil(linearGeom);
  61   const double startIndex2 = clampIndex(startIndex);
  62   const double endIndex2 = clampIndex(endIndex);
  63   // if extracted line is zero-length, resolve start lower as well to
  64   // ensure they are equal
  65   const bool resolveStartLower = ( startIndex2 == endIndex2 );
  66   const LinearLocation startLoc = locationOf(startIndex2, resolveStartLower);
  67   const LinearLocation endLoc = locationOf(endIndex2);
  68 //    LinearLocation endLoc = locationOf(endIndex2, true);
  69 //    LinearLocation startLoc = locationOf(startIndex2);
  70   return ExtractLineByLocation::extract(linearGeom, startLoc, endLoc);
  71 }
  72
  73 LinearLocation LengthIndexedLine::locationOf(double index) const
  74 {
  75         return LengthLocationMap::getLocation(linearGeom, index);
  76 }
  77
  78 LinearLocation
  79 LengthIndexedLine::locationOf(double index, bool resolveLower) const
  80 {
  81         return LengthLocationMap::getLocation(linearGeom, index, resolveLower);
  82 }
  83
  84
  85 double LengthIndexedLine::indexOf(const Coordinate& pt) const
  86 {
  87         return LengthIndexOfPoint::indexOf(linearGeom, pt);
  88 }
  89
  90
  91 double LengthIndexedLine::indexOfAfter(const Coordinate& pt, double minIndex) const
  92 {
  93         return LengthIndexOfPoint::indexOfAfter(linearGeom, pt, minIndex);
  94 }
  95
  96
  97 double* LengthIndexedLine::indicesOf(const Geometry* subLine) const
  98 {
  99         LinearLocation* locIndex = LocationIndexOfLine::indicesOf(linearGeom, subLine);
 100         double* index = new double[2];
 101         index[0] = LengthLocationMap::getLength(linearGeom, locIndex[0]);
 102         index[1] = LengthLocationMap::getLength(linearGeom, locIndex[1]);
 103         delete [] locIndex;
 104         return index;
 105 }
 106
 107
 108 double LengthIndexedLine::project(const Coordinate& pt) const
 109 {
 110         return LengthIndexOfPoint::indexOf(linearGeom, pt);
 111 }
 112
 113 double LengthIndexedLine::getStartIndex() const
 114 {
 115         return 0.0;
 116 }
 117
 118 double LengthIndexedLine::getEndIndex() const
 119 {
 120         return linearGeom->getLength();
 121 }
 122
 123 bool LengthIndexedLine::isValidIndex(double index) const
 124 {
 125         return (index >= getStartIndex()
 126                 && index <= getEndIndex());
 127 }
 128
 129 /* public */
 130 double
 131 LengthIndexedLine::clampIndex(double index) const
 132 {
 133   double posIndex = positiveIndex(index);
 134         double startIndex = getStartIndex();
 135   if (posIndex < startIndex) return startIndex;
 136
 137         double endIndex = getEndIndex();
 138         if (posIndex > endIndex) return endIndex;
 139
 140         return posIndex;
 141 }
 142
 143 /* private */
 144 double
 145 LengthIndexedLine::positiveIndex(double index) const
 146 {
 147   if (index >= 0.0) return index;
 148   return linearGeom->getLength() + index;
 149 }
 150
 151 } // geos.linearref
 152 } // geos