1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>densify</title> 5<link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../../index.html" title="Chapter 1. Geometry"> 8<link rel="up" href="../densify.html" title="densify"> 9<link rel="prev" href="densify_4_with_strategy.html" title="densify (with strategy)"> 10<link rel="next" href="../difference.html" title="difference"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="densify_4_with_strategy.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../densify.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../difference.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h5 class="title"> 27<a name="geometry.reference.algorithms.densify.densify_3"></a><a class="link" href="densify_3.html" title="densify">densify</a> 28</h5></div></div></div> 29<p> 30 <a class="indexterm" name="idm45635701769072"></a> 31Densify a geometry. 32 </p> 33<h6> 34<a name="geometry.reference.algorithms.densify.densify_3.h0"></a> 35 <span class="phrase"><a name="geometry.reference.algorithms.densify.densify_3.synopsis"></a></span><a class="link" href="densify_3.html#geometry.reference.algorithms.densify.densify_3.synopsis">Synopsis</a> 36 </h6> 37<p> 38</p> 39<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Geometry</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Distance</span><span class="special">></span> 40<span class="keyword">void</span> <span class="identifier">densify</span><span class="special">(</span><span class="identifier">Geometry</span> <span class="keyword">const</span> <span class="special">&</span> <span class="identifier">geometry</span><span class="special">,</span> <span class="identifier">Geometry</span> <span class="special">&</span> <span class="identifier">out</span><span class="special">,</span> <span class="identifier">Distance</span> <span class="keyword">const</span> <span class="special">&</span> <span class="identifier">max_distance</span><span class="special">)</span></pre> 41<p> 42 </p> 43<h6> 44<a name="geometry.reference.algorithms.densify.densify_3.h1"></a> 45 <span class="phrase"><a name="geometry.reference.algorithms.densify.densify_3.parameters"></a></span><a class="link" href="densify_3.html#geometry.reference.algorithms.densify.densify_3.parameters">Parameters</a> 46 </h6> 47<div class="informaltable"><table class="table"> 48<colgroup> 49<col> 50<col> 51<col> 52<col> 53</colgroup> 54<thead><tr> 55<th> 56 <p> 57 Type 58 </p> 59 </th> 60<th> 61 <p> 62 Concept 63 </p> 64 </th> 65<th> 66 <p> 67 Name 68 </p> 69 </th> 70<th> 71 <p> 72 Description 73 </p> 74 </th> 75</tr></thead> 76<tbody> 77<tr> 78<td> 79 <p> 80 Geometry const & 81 </p> 82 </td> 83<td> 84 <p> 85 Any type fulfilling a Geometry Concept 86 </p> 87 </td> 88<td> 89 <p> 90 geometry 91 </p> 92 </td> 93<td> 94 <p> 95 Input geometry, to be densified 96 </p> 97 </td> 98</tr> 99<tr> 100<td> 101 <p> 102 Geometry & 103 </p> 104 </td> 105<td> 106 <p> 107 Any type fulfilling a Geometry Concept 108 </p> 109 </td> 110<td> 111 <p> 112 out 113 </p> 114 </td> 115<td> 116 <p> 117 Output geometry, densified version of the input geometry 118 </p> 119 </td> 120</tr> 121<tr> 122<td> 123 <p> 124 Distance const & 125 </p> 126 </td> 127<td> 128 <p> 129 A numerical distance measure 130 </p> 131 </td> 132<td> 133 <p> 134 max_distance 135 </p> 136 </td> 137<td> 138 <p> 139 Distance threshold (in units depending on coordinate system) 140 </p> 141 </td> 142</tr> 143</tbody> 144</table></div> 145<h6> 146<a name="geometry.reference.algorithms.densify.densify_3.h2"></a> 147 <span class="phrase"><a name="geometry.reference.algorithms.densify.densify_3.header"></a></span><a class="link" href="densify_3.html#geometry.reference.algorithms.densify.densify_3.header">Header</a> 148 </h6> 149<p> 150 Either 151 </p> 152<p> 153 <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 154 </p> 155<p> 156 Or 157 </p> 158<p> 159 <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">algorithms</span><span class="special">/</span><span class="identifier">densify</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 160 </p> 161<h6> 162<a name="geometry.reference.algorithms.densify.densify_3.h3"></a> 163 <span class="phrase"><a name="geometry.reference.algorithms.densify.densify_3.conformance"></a></span><a class="link" href="densify_3.html#geometry.reference.algorithms.densify.densify_3.conformance">Conformance</a> 164 </h6> 165<p> 166 The function densify is not defined by OGC. 167 </p> 168<div class="note"><table border="0" summary="Note"> 169<tr> 170<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../../doc/src/images/note.png"></td> 171<th align="left">Note</th> 172</tr> 173<tr><td align="left" valign="top"><p> 174 PostGIS contains an algorithm ST_Segmentize with the same functionality. 175 See the <a href="http://www.postgis.org/docs/ST_Segmentize.html" target="_top">PostGIS 176 documentation</a>. 177 </p></td></tr> 178</table></div> 179<h6> 180<a name="geometry.reference.algorithms.densify.densify_3.h4"></a> 181 <span class="phrase"><a name="geometry.reference.algorithms.densify.densify_3.behavior"></a></span><a class="link" href="densify_3.html#geometry.reference.algorithms.densify.densify_3.behavior">Behavior</a> 182 </h6> 183<p> 184 The algorithm divides segments of a geometry if they are longer than 185 passed distance into smaller segments. 186 </p> 187<div class="note"><table border="0" summary="Note"> 188<tr> 189<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../../doc/src/images/note.png"></td> 190<th align="left">Note</th> 191</tr> 192<tr><td align="left" valign="top"><p> 193 The units of the distance depends on strategy. In order to change the 194 default behavior a user has to create a strategy and pass it explicitly 195 into the algorithm. 196 </p></td></tr> 197</table></div> 198<h6> 199<a name="geometry.reference.algorithms.densify.densify_3.h5"></a> 200 <span class="phrase"><a name="geometry.reference.algorithms.densify.densify_3.example"></a></span><a class="link" href="densify_3.html#geometry.reference.algorithms.densify.densify_3.example">Example</a> 201 </h6> 202<p> 203 Shows how to densify a polygon 204 </p> 205<p> 206</p> 207<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> 208 209<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 210<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">point_xy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 211<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">polygon</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 212 213<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> 214<span class="special">{</span> 215 <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">d2</span><span class="special">::</span><span class="identifier">point_xy</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">point_type</span><span class="special">;</span> 216 <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">polygon</span><span class="special"><</span><span class="identifier">point_type</span><span class="special">></span> <span class="identifier">polygon_type</span><span class="special">;</span> 217 218 <span class="identifier">polygon_type</span> <span class="identifier">poly</span><span class="special">;</span> 219 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">read_wkt</span><span class="special">(</span> 220 <span class="string">"POLYGON((0 0,0 10,10 10,10 0,0 0),(1 1,4 1,4 4,1 4,1 1))"</span><span class="special">,</span> <span class="identifier">poly</span><span class="special">);</span> 221 222 <span class="identifier">polygon_type</span> <span class="identifier">res</span><span class="special">;</span> 223 224 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">densify</span><span class="special">(</span><span class="identifier">poly</span><span class="special">,</span> <span class="identifier">res</span><span class="special">,</span> <span class="number">6.0</span><span class="special">);</span> 225 226 <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"densified: "</span> <span class="special"><<</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">wkt</span><span class="special">(</span><span class="identifier">res</span><span class="special">)</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> 227 228 <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> 229<span class="special">}</span> 230</pre> 231<p> 232 </p> 233<p> 234 Output: 235 </p> 236<pre class="programlisting">densified: POLYGON((0 0,0 5,0 10,5 10,10 10,10 5,10 0,5 0,0 0),(1 1,4 1,4 4,1 4,1 1)) 237</pre> 238<h6> 239<a name="geometry.reference.algorithms.densify.densify_3.h6"></a> 240 <span class="phrase"><a name="geometry.reference.algorithms.densify.densify_3.see_also"></a></span><a class="link" href="densify_3.html#geometry.reference.algorithms.densify.densify_3.see_also">See 241 also</a> 242 </h6> 243<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> 244 <a class="link" href="../line_interpolate.html" title="line_interpolate">line_interpolate</a> 245 </li></ul></div> 246</div> 247<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 248<td align="left"></td> 249<td align="right"><div class="copyright-footer">Copyright © 2009-2019 Barend Gehrels, Bruno Lalande, Mateusz Loskot, Adam 250 Wulkiewicz, Oracle and/or its affiliates<p> 251 Distributed under the Boost Software License, Version 1.0. (See accompanying 252 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 253 </p> 254</div></td> 255</tr></table> 256<hr> 257<div class="spirit-nav"> 258<a accesskey="p" href="densify_4_with_strategy.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../densify.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../difference.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 259</div> 260</body> 261</html> 262
