ceph/src/boost/libs/polygon/doc/gtl_connectivity_extraction_usage.htm

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  10 <p><font face="Courier New">#include &lt;boost/polygon/polygon.hpp&gt;<br>
  11 #include &lt;cassert&gt;<br>
  12 namespace gtl = boost::polygon;<br>
  13 <br>
  14 //This function works with both the 90 and 45 versions<br>
  15 //of connectivity extraction algroithm<br>
  16 template &lt;typename ce_type&gt;<br>
  17 void test_ce() {<br>
  18 &nbsp; //first we create an object to do the connectivity extraction<br>
  19 &nbsp; ce_type ce;<br>
  20 <br>
  21 &nbsp; //create some test data<br>
  22 &nbsp; std::vector&lt;gtl::rectangle_data&lt;int&gt; &gt; test_data;<br>
  23 &nbsp; test_data.push_back(gtl::rectangle_data&lt;int&gt;(10, 10, 90, 90));<br>
  24 &nbsp; test_data.push_back(gtl::rectangle_data&lt;int&gt;(0, 0, 20, 20));<br>
  25 &nbsp; test_data.push_back(gtl::rectangle_data&lt;int&gt;(80, 0, 100, 20));<br>
  26 &nbsp; test_data.push_back(gtl::rectangle_data&lt;int&gt;(0, 80, 20, 100));<br>
  27 &nbsp; test_data.push_back(gtl::rectangle_data&lt;int&gt;(80, 80, 100, 100));<br>
  28 &nbsp; //There is one big square and four little squares covering each<br>
  29 &nbsp; //of its corners.<br>
  30 <br>
  31 &nbsp; for(unsigned int i = 0; i &lt; test_data.size(); ++i) {<br>
  32 &nbsp;&nbsp;&nbsp; //insert returns an id starting at zero and incrementing<br>
  33 &nbsp;&nbsp;&nbsp; //with each call<br>
  34 &nbsp;&nbsp;&nbsp; assert(ce.insert(test_data[i]) == i);<br>
  35 &nbsp; }<br>
  36 &nbsp; //notice that ids returned by ce.insert happen to match<br>
  37 &nbsp; //index into vector of inputs in this case<br>
  38 <br>
  39 &nbsp; //make sure the vector graph has elements for our nodes<br>
  40 &nbsp; std::vector&lt;std::set&lt;int&gt; &gt; graph(test_data.size());<br>
  41 <br>
  42 &nbsp; //populate the graph with edge data<br>
  43 &nbsp; ce.extract(graph);<br>
  44 <br>
  45 &nbsp; //make a map type graph to compare results<br>
  46 &nbsp; std::map&lt;int, std::set&lt;int&gt; &gt; map_graph;<br>
  47 &nbsp; ce.extract(map_graph);<br>
  48 <br>
  49 &nbsp; assert(map_graph.size() &amp;&amp; map_graph.size() == graph.size());<br>
  50 &nbsp; for(unsigned int i = 0; i &lt; graph.size(); ++i) {<br>
  51 &nbsp;&nbsp;&nbsp; assert(graph[i] == map_graph[i]);<br>
  52 &nbsp;&nbsp;&nbsp; if(i == 0)<br>
  53 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; assert(graph[i].size() == 4); //four little
  54 squares<br>
  55 &nbsp;&nbsp;&nbsp; else<br>
  56 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; assert(graph[i].size() == 1); //each little
  57 toches the big square<br>
  58 &nbsp; }<br>
  59 }<br>
  60 <br>
  61 int main() {<br>
  62 &nbsp; test_ce&lt;gtl::connectivity_extraction_90&lt;int&gt; &gt;();<br>
  63 &nbsp; test_ce&lt;gtl::connectivity_extraction_45&lt;int&gt; &gt;();<br>
  64 &nbsp; return 0;<br>
  65 }<br>
  66 <br>
  67 //Now you know how to use the connectivity extraction algorithm<br>
  68 //to extract the connectivity graph for overlapping geometry<br>
  69 &nbsp;</font></p>
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  78                         <th class="docinfo-name">Copyright:</th>
  79                         <td>Copyright © Intel Corporation 2008-2010.</td>
  80                 </tr>
  81                 <tr class="field">
  82                         <th class="docinfo-name">License:</th>
  83                         <td class="field-body">Distributed under the Boost Software License,
  84                         Version 1.0. (See accompanying file <tt class="literal">
  85                         <span class="pre">LICENSE_1_0.txt</span></tt> or copy at
  86                         <a class="reference" target="_top" href="http://www.boost.org/LICENSE_1_0.txt">
  87                         http://www.boost.org/LICENSE_1_0.txt</a>)</td>
  88                 </tr>
  89 </table>
  90
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