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  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="idm46186973848960"></a><a class="indexterm" name="idm46186973848272"></a><a class="indexterm" name="idm46186973847584"></a>
  31 Create 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">&lt;</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">&gt;</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&lt;double&gt;
 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">&lt;</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">&gt;</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">&lt;</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">&gt;</span>
 196 <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</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">&lt;</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">&lt;</span><span class="identifier">bg</span><span class="special">::</span><span class="identifier">degree</span><span class="special">&gt;</span> <span class="special">&gt;</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">&lt;&gt;</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">&lt;</span><span class="keyword">double</span><span class="special">&gt;</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">&lt;</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">&lt;</span><span class="identifier">point</span><span class="special">&gt;</span> <span class="special">&gt;</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">&lt;&lt;</span> <span class="string">"Area: "</span> <span class="special">&lt;&lt;</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">&lt;&lt;</span> <span class="string">" square kilometer"</span> <span class="special">&lt;&lt;</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 &#169; 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>
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