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<h1>CentralEndpointIntersector.h</h1> </div>
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<div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/**********************************************************************</span>
<a name="l00002"></a>00002 <span class="comment"> * $Id: CentralEndpointIntersector.h 2137 2008-07-25 21:00:09Z mloskot $</span>
<a name="l00003"></a>00003 <span class="comment"> *</span>
<a name="l00004"></a>00004 <span class="comment"> * GEOS - Geometry Engine Open Source</span>
<a name="l00005"></a>00005 <span class="comment"> * http://geos.refractions.net</span>
<a name="l00006"></a>00006 <span class="comment"> *</span>
<a name="l00007"></a>00007 <span class="comment"> * Copyright (C) 2006 Refractions Research Inc.</span>
<a name="l00008"></a>00008 <span class="comment"> *</span>
<a name="l00009"></a>00009 <span class="comment"> * This is free software; you can redistribute and/or modify it under</span>
<a name="l00010"></a>00010 <span class="comment"> * the terms of the GNU Lesser General Public Licence as published</span>
<a name="l00011"></a>00011 <span class="comment"> * by the Free Software Foundation. </span>
<a name="l00012"></a>00012 <span class="comment"> * See the COPYING file for more information.</span>
<a name="l00013"></a>00013 <span class="comment"> *</span>
<a name="l00014"></a>00014 <span class="comment"> **********************************************************************</span>
<a name="l00015"></a>00015 <span class="comment"> *</span>
<a name="l00016"></a>00016 <span class="comment"> * Last port: algorithm/CentralEndpointIntersector.java rev. 1.1</span>
<a name="l00017"></a>00017 <span class="comment"> *</span>
<a name="l00018"></a>00018 <span class="comment"> **********************************************************************/</span>
<a name="l00019"></a>00019
<a name="l00020"></a>00020 <span class="preprocessor">#ifndef GEOS_ALGORITHM_CENTRALENDPOINTINTERSECTOR_H</span>
<a name="l00021"></a>00021 <span class="preprocessor"></span><span class="preprocessor">#define GEOS_ALGORITHM_CENTRALENDPOINTINTERSECTOR_H</span>
<a name="l00022"></a>00022 <span class="preprocessor"></span>
<a name="l00023"></a>00023 <span class="preprocessor">#include <geos/geom/Coordinate.h></span>
<a name="l00024"></a>00024
<a name="l00025"></a>00025 <span class="preprocessor">#include <string></span>
<a name="l00026"></a>00026 <span class="preprocessor">#include <limits></span>
<a name="l00027"></a>00027
<a name="l00028"></a>00028 <span class="comment">// Forward declarations</span>
<a name="l00029"></a>00029 <span class="keyword">namespace </span>geos {
<a name="l00030"></a>00030 <span class="keyword">namespace </span>geom {
<a name="l00031"></a>00031 <span class="comment">//class PrecisionModel;</span>
<a name="l00032"></a>00032 }
<a name="l00033"></a>00033 }
<a name="l00034"></a>00034
<a name="l00035"></a>00035 <span class="keyword">namespace </span>geos {
<a name="l00036"></a>00036 <span class="keyword">namespace </span>algorithm { <span class="comment">// geos::algorithm</span>
<a name="l00037"></a>00037
<a name="l00057"></a><a class="code" href="classgeos_1_1algorithm_1_1CentralEndpointIntersector.html">00057</a> <span class="keyword">class </span><a class="code" href="classgeos_1_1algorithm_1_1CentralEndpointIntersector.html" title="Computes an approximate intersection of two line segments by taking the most central of the endpoints...">CentralEndpointIntersector</a> {
<a name="l00058"></a>00058
<a name="l00059"></a>00059 <span class="keyword">public</span>:
<a name="l00060"></a>00060
<a name="l00061"></a>00061 <span class="keyword">static</span> <span class="keyword">const</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a>& getIntersection(<span class="keyword">const</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a>& p00,
<a name="l00062"></a>00062 <span class="keyword">const</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a>& p01, <span class="keyword">const</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a>& p10,
<a name="l00063"></a>00063 <span class="keyword">const</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a>& p11)
<a name="l00064"></a>00064 {
<a name="l00065"></a>00065 <a class="code" href="classgeos_1_1algorithm_1_1CentralEndpointIntersector.html" title="Computes an approximate intersection of two line segments by taking the most central of the endpoints...">CentralEndpointIntersector</a> intor(p00, p01, p10, p11);
<a name="l00066"></a>00066 <span class="keywordflow">return</span> intor.getIntersection();
<a name="l00067"></a>00067 }
<a name="l00068"></a>00068
<a name="l00069"></a>00069 <a class="code" href="classgeos_1_1algorithm_1_1CentralEndpointIntersector.html" title="Computes an approximate intersection of two line segments by taking the most central of the endpoints...">CentralEndpointIntersector</a>(<span class="keyword">const</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a>& p00,
<a name="l00070"></a>00070 <span class="keyword">const</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a>& p01,
<a name="l00071"></a>00071 <span class="keyword">const</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a>& p10,
<a name="l00072"></a>00072 <span class="keyword">const</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a>& p11)
<a name="l00073"></a>00073 :
<a name="l00074"></a>00074 _pts(4)
<a name="l00075"></a>00075 {
<a name="l00076"></a>00076 _pts[0]=p00;
<a name="l00077"></a>00077 _pts[1]=p01;
<a name="l00078"></a>00078 _pts[2]=p10;
<a name="l00079"></a>00079 _pts[3]=p11;
<a name="l00080"></a>00080 compute();
<a name="l00081"></a>00081 }
<a name="l00082"></a>00082
<a name="l00083"></a>00083 <span class="keyword">const</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a>& getIntersection()<span class="keyword"> const</span>
<a name="l00084"></a>00084 <span class="keyword"> </span>{
<a name="l00085"></a>00085 <span class="keywordflow">return</span> _intPt;
<a name="l00086"></a>00086 }
<a name="l00087"></a>00087
<a name="l00088"></a>00088
<a name="l00089"></a>00089 <span class="keyword">private</span>:
<a name="l00090"></a>00090
<a name="l00091"></a>00091 <span class="comment">// This is likely overkill.. we'll be allocating heap</span>
<a name="l00092"></a>00092 <span class="comment">// memory at every call !</span>
<a name="l00093"></a>00093 std::vector<geom::Coordinate> _pts;
<a name="l00094"></a>00094
<a name="l00095"></a>00095 <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a> _intPt;
<a name="l00096"></a>00096
<a name="l00097"></a>00097 <span class="keywordtype">void</span> compute()
<a name="l00098"></a>00098 {
<a name="l00099"></a>00099 <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a> centroid = average(_pts);
<a name="l00100"></a>00100 _intPt = findNearestPoint(centroid, _pts);
<a name="l00101"></a>00101 }
<a name="l00102"></a>00102
<a name="l00103"></a>00103 <span class="keyword">static</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a> average(
<a name="l00104"></a>00104 <span class="keyword">const</span> std::vector<geom::Coordinate>& pts)
<a name="l00105"></a>00105 {
<a name="l00106"></a>00106 <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a> avg(0, 0);
<a name="l00107"></a>00107 <span class="keywordtype">size_t</span> n = pts.size();
<a name="l00108"></a>00108 <span class="keywordflow">if</span> ( ! n ) <span class="keywordflow">return</span> avg;
<a name="l00109"></a>00109 <span class="keywordflow">for</span> (<span class="keywordtype">size_t</span> i=0; i<n; ++i)
<a name="l00110"></a>00110 {
<a name="l00111"></a>00111 avg.<a class="code" href="classgeos_1_1geom_1_1Coordinate.html#ad809a77e5715e490a7e5f95c8611737e" title="x-coordinate">x</a> += pts[i].x;
<a name="l00112"></a>00112 avg.<a class="code" href="classgeos_1_1geom_1_1Coordinate.html#acdeb58356624ebe25cbbf5b6021c3d9d" title="y-coordinate">y</a> += pts[i].y;
<a name="l00113"></a>00113 }
<a name="l00114"></a>00114 avg.<a class="code" href="classgeos_1_1geom_1_1Coordinate.html#ad809a77e5715e490a7e5f95c8611737e" title="x-coordinate">x</a> /= n;
<a name="l00115"></a>00115 avg.<a class="code" href="classgeos_1_1geom_1_1Coordinate.html#acdeb58356624ebe25cbbf5b6021c3d9d" title="y-coordinate">y</a> /= n;
<a name="l00116"></a>00116 <span class="keywordflow">return</span> avg;
<a name="l00117"></a>00117 }
<a name="l00118"></a>00118
<a name="l00129"></a>00129 <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a> findNearestPoint(<span class="keyword">const</span> <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a>& p,
<a name="l00130"></a>00130 <span class="keyword">const</span> std::vector<geom::Coordinate>& pts)<span class="keyword"> const</span>
<a name="l00131"></a>00131 <span class="keyword"> </span>{
<a name="l00132"></a>00132 <span class="keywordtype">double</span> minDist = std::numeric_limits<double>::max();
<a name="l00133"></a>00133 <a class="code" href="classgeos_1_1geom_1_1Coordinate.html" title="Coordinate is the lightweight class used to store coordinates.">geom::Coordinate</a> result = geom::Coordinate::getNull();
<a name="l00134"></a>00134 <span class="keywordflow">for</span> (<span class="keywordtype">size_t</span> i = 0, n=pts.size(); i < n; ++i) {
<a name="l00135"></a>00135 <span class="keywordtype">double</span> dist = p.<a class="code" href="classgeos_1_1geom_1_1Coordinate.html#a9a30687133579e261178d099a238ef19">distance</a>(pts[i]);
<a name="l00136"></a>00136 <span class="keywordflow">if</span> (dist < minDist) {
<a name="l00137"></a>00137 minDist = dist;
<a name="l00138"></a>00138 result = pts[i];
<a name="l00139"></a>00139 }
<a name="l00140"></a>00140 }
<a name="l00141"></a>00141 <span class="keywordflow">return</span> result;
<a name="l00142"></a>00142 }
<a name="l00143"></a>00143
<a name="l00144"></a>00144
<a name="l00145"></a>00145
<a name="l00146"></a>00146 };
<a name="l00147"></a>00147
<a name="l00148"></a>00148 } <span class="comment">// namespace geos::algorithm</span>
<a name="l00149"></a>00149 } <span class="comment">// namespace geos</span>
<a name="l00150"></a>00150
<a name="l00151"></a>00151
<a name="l00152"></a>00152 <span class="preprocessor">#endif // GEOS_ALGORITHM_CENTRALENDPOINTINTERSECTOR_H</span>
<a name="l00153"></a>00153 <span class="preprocessor"></span>
<a name="l00154"></a>00154 <span class="comment">/**********************************************************************</span>
<a name="l00155"></a>00155 <span class="comment"> * $Log$</span>
<a name="l00156"></a>00156 <span class="comment"> **********************************************************************/</span>
<a name="l00157"></a>00157
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