1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>strategy::buffer::geographic_point_circle</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="../strategies.html" title="Strategies"> 9<link rel="prev" href="strategy_buffer_point_square.html" title="strategy::buffer::point_square"> 10<link rel="next" href="strategy_buffer_side_straight.html" title="strategy::buffer::side_straight"> 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="strategy_buffer_point_square.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../strategies.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="strategy_buffer_side_straight.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h4 class="title"> 27<a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle"></a><a class="link" href="strategy_buffer_geographic_point_circle.html" title="strategy::buffer::geographic_point_circle">strategy::buffer::geographic_point_circle</a> 28</h4></div></div></div> 29<p> 30 <a class="indexterm" name="idm45635670065152"></a><a class="indexterm" name="idm45635670064464"></a><a class="indexterm" name="idm45635670063776"></a> 31Create a circular buffer around a point, on the Earth. 32 </p> 33<h6> 34<a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.h0"></a> 35 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.description"></a></span><a class="link" href="strategy_buffer_geographic_point_circle.html#geometry.reference.strategies.strategy_buffer_geographic_point_circle.description">Description</a> 36 </h6> 37<p> 38 This strategy can be used as PointStrategy for the buffer algorithm. It 39 creates a circular buffer around a point, on the Earth. It can be applied 40 for points and multi_points. 41 </p> 42<h6> 43<a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.h1"></a> 44 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.synopsis"></a></span><a class="link" href="strategy_buffer_geographic_point_circle.html#geometry.reference.strategies.strategy_buffer_geographic_point_circle.synopsis">Synopsis</a> 45 </h6> 46<p> 47</p> 48<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">FormulaPolicy</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Spheroid</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">CalculationType</span><span class="special">></span> 49<span class="keyword">class</span> <span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">geographic_point_circle</span> 50<span class="special">{</span> 51 <span class="comment">// ...</span> 52<span class="special">};</span> 53</pre> 54<p> 55 </p> 56<h6> 57<a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.h2"></a> 58 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.template_parameter_s_"></a></span><a class="link" href="strategy_buffer_geographic_point_circle.html#geometry.reference.strategies.strategy_buffer_geographic_point_circle.template_parameter_s_">Template 59 parameter(s)</a> 60 </h6> 61<div class="informaltable"><table class="table"> 62<colgroup> 63<col> 64<col> 65<col> 66</colgroup> 67<thead><tr> 68<th> 69 <p> 70 Parameter 71 </p> 72 </th> 73<th> 74 <p> 75 Default 76 </p> 77 </th> 78<th> 79 <p> 80 Description 81 </p> 82 </th> 83</tr></thead> 84<tbody> 85<tr> 86<td> 87 <p> 88 typename FormulaPolicy 89 </p> 90 </td> 91<td> 92 <p> 93 strategy::andoyer 94 </p> 95 </td> 96<td> 97 </td> 98</tr> 99<tr> 100<td> 101 <p> 102 typename Spheroid 103 </p> 104 </td> 105<td> 106 <p> 107 srs::spheroid<double> 108 </p> 109 </td> 110<td> 111 </td> 112</tr> 113<tr> 114<td> 115 <p> 116 typename CalculationType 117 </p> 118 </td> 119<td> 120 <p> 121 void 122 </p> 123 </td> 124<td> 125 </td> 126</tr> 127</tbody> 128</table></div> 129<h6> 130<a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.h3"></a> 131 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.constructor_s_"></a></span><a class="link" href="strategy_buffer_geographic_point_circle.html#geometry.reference.strategies.strategy_buffer_geographic_point_circle.constructor_s_">Constructor(s)</a> 132 </h6> 133<div class="informaltable"><table class="table"> 134<colgroup> 135<col> 136<col> 137<col> 138</colgroup> 139<thead><tr> 140<th> 141 <p> 142 Function 143 </p> 144 </th> 145<th> 146 <p> 147 Description 148 </p> 149 </th> 150<th> 151 <p> 152 Parameters 153 </p> 154 </th> 155</tr></thead> 156<tbody><tr> 157<td> 158 <p> 159</p> 160<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="identifier">geographic_point_circle</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">count</span> <span class="special">=</span> <span class="number">90</span><span class="special">)</span></pre> 161<p> 162 </p> 163 </td> 164<td> 165 <p> 166 Constructs the strategy. 167 </p> 168 </td> 169<td> 170 <p> 171 <span class="bold"><strong>std::size_t</strong></span>: <span class="emphasis"><em>count</em></span>: 172 number of points for the created circle (if count is smaller 173 than 3, count is internally set to 3) 174 </p> 175 </td> 176</tr></tbody> 177</table></div> 178<h6> 179<a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.h4"></a> 180 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.header"></a></span><a class="link" href="strategy_buffer_geographic_point_circle.html#geometry.reference.strategies.strategy_buffer_geographic_point_circle.header">Header</a> 181 </h6> 182<p> 183 <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">strategies</span><span class="special">/</span><span class="identifier">geographic</span><span class="special">/</span><span class="identifier">buffer_point_circle</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 184 </p> 185<h6> 186<a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.h5"></a> 187 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.example"></a></span><a class="link" href="strategy_buffer_geographic_point_circle.html#geometry.reference.strategies.strategy_buffer_geographic_point_circle.example">Example</a> 188 </h6> 189<p> 190 Shows how the point_circle strategy, for the Earth, can be used as a PointStrategy 191 to create circular buffers around points 192 </p> 193<p> 194</p> 195<pre class="programlisting"><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> 196<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> 197 198<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> 199<span class="special">{</span> 200 <span class="keyword">namespace</span> <span class="identifier">bg</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">;</span> 201 202 <span class="keyword">typedef</span> <span class="identifier">bg</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">point</span><span class="special"><</span><span class="keyword">double</span><span class="special">,</span> <span class="number">2</span><span class="special">,</span> <span class="identifier">bg</span><span class="special">::</span><span class="identifier">cs</span><span class="special">::</span><span class="identifier">geographic</span><span class="special"><</span><span class="identifier">bg</span><span class="special">::</span><span class="identifier">degree</span><span class="special">></span> <span class="special">></span> <span class="identifier">point</span><span class="special">;</span> 203 204 <span class="comment">// Declare the geographic_point_circle strategy (with 36 points)</span> 205 <span class="comment">// Default template arguments (taking Andoyer strategy)</span> 206 <span class="identifier">bg</span><span class="special">::</span><span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">geographic_point_circle</span><span class="special"><></span> <span class="identifier">point_strategy</span><span class="special">(</span><span class="number">36</span><span class="special">);</span> 207 208 <span class="comment">// Declare the distance strategy (one kilometer, around the point, on Earth)</span> 209 <span class="identifier">bg</span><span class="special">::</span><span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">distance_symmetric</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">distance_strategy</span><span class="special">(</span><span class="number">1000.0</span><span class="special">);</span> 210 211 <span class="comment">// Declare other necessary strategies, unused for point</span> 212 <span class="identifier">bg</span><span class="special">::</span><span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">join_round</span> <span class="identifier">join_strategy</span><span class="special">;</span> 213 <span class="identifier">bg</span><span class="special">::</span><span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">end_round</span> <span class="identifier">end_strategy</span><span class="special">;</span> 214 <span class="identifier">bg</span><span class="special">::</span><span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">side_straight</span> <span class="identifier">side_strategy</span><span class="special">;</span> 215 216 <span class="comment">// Declare/fill a point on Earth, near Amsterdam</span> 217 <span class="identifier">point</span> <span class="identifier">p</span><span class="special">;</span> 218 <span class="identifier">bg</span><span class="special">::</span><span class="identifier">read_wkt</span><span class="special">(</span><span class="string">"POINT(4.9 52.1)"</span><span class="special">,</span> <span class="identifier">p</span><span class="special">);</span> 219 220 <span class="comment">// Create the buffer of a point on the Earth</span> 221 <span class="identifier">bg</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">multi_polygon</span><span class="special"><</span><span class="identifier">bg</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</span><span class="special">></span> <span class="special">></span> <span class="identifier">result</span><span class="special">;</span> 222 <span class="identifier">bg</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">p</span><span class="special">,</span> <span class="identifier">result</span><span class="special">,</span> 223 <span class="identifier">distance_strategy</span><span class="special">,</span> <span class="identifier">side_strategy</span><span class="special">,</span> 224 <span class="identifier">join_strategy</span><span class="special">,</span> <span class="identifier">end_strategy</span><span class="special">,</span> <span class="identifier">point_strategy</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">"Area: "</span> <span class="special"><<</span> <span class="identifier">bg</span><span class="special">::</span><span class="identifier">area</span><span class="special">(</span><span class="identifier">result</span><span class="special">)</span> <span class="special">/</span> <span class="special">(</span><span class="number">1000</span> <span class="special">*</span> <span class="number">1000</span><span class="special">)</span> <span class="special"><<</span> <span class="string">" square kilometer"</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">Area: 3.12542 square kilometer 237</pre> 238<h6> 239<a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.h6"></a> 240 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_geographic_point_circle.see_also"></a></span><a class="link" href="strategy_buffer_geographic_point_circle.html#geometry.reference.strategies.strategy_buffer_geographic_point_circle.see_also">See 241 also</a> 242 </h6> 243<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 244<li class="listitem"> 245 <a class="link" href="../algorithms/buffer/buffer_7_with_strategies.html" title="buffer (with strategies)">buffer 246 (with strategies)</a> 247 </li> 248<li class="listitem"> 249 <a class="link" href="strategy_buffer_point_circle.html" title="strategy::buffer::point_circle">point_circle</a> 250 </li> 251<li class="listitem"> 252 <a class="link" href="strategy_buffer_point_square.html" title="strategy::buffer::point_square">point_square</a> 253 </li> 254</ul></div> 255</div> 256<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 257<td align="left"></td> 258<td align="right"><div class="copyright-footer">Copyright © 2009-2019 Barend Gehrels, Bruno Lalande, Mateusz Loskot, Adam 259 Wulkiewicz, Oracle and/or its affiliates<p> 260 Distributed under the Boost Software License, Version 1.0. (See accompanying 261 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>) 262 </p> 263</div></td> 264</tr></table> 265<hr> 266<div class="spirit-nav"> 267<a accesskey="p" href="strategy_buffer_point_square.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../strategies.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="strategy_buffer_side_straight.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 268</div> 269</body> 270</html> 271
