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

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  10 <p><font face="Courier New">/*<br>
  11 Copyright 2008 Intel Corporation<br>
  12 <br>
  13 Use, modification and distribution are subject to the Boost Software License,<br>
  14 Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at<br>
  15 http://www.boost.org/LICENSE_1_0.txt).<br>
  16 */<br>
  17 #include &lt;boost/polygon/polygon.hpp&gt;<br>
  18 #include &lt;cassert&gt;<br>
  19 namespace gtl = boost::polygon;<br>
  20 using namespace boost::polygon::operators;<br>
  21 <br>//just a little meta-programming to get things off on the right foot<br>
  22 template &lt;typename T&gt;<br>
  23 struct lookup_polygon_set_type { typedef gtl::polygon_set_data&lt;int&gt; type; };<br>
  24 template &lt;typename T, typename T2&gt;<br>
  25 struct lookup_polygon_set_type&lt;gtl::property_merge_90&lt;T, T2&gt; &gt; { <br>
  26 &nbsp; typedef gtl::polygon_90_set_data&lt;int&gt; type; };<br>
  27 <br>
  28 //This function works with both the 90 and general versions<br>
  29 //of property merge/map overlay algorithm<br>
  30 template &lt;typename pm_type&gt;<br>
  31 void test_pm() {<br>
  32 &nbsp; std::vector&lt;gtl::rectangle_data&lt;int&gt; &gt; test_data;<br>
  33 &nbsp; test_data.push_back(gtl::rectangle_data&lt;int&gt;(11, 10, 31, 30));<br>
  34 &nbsp; test_data.push_back(gtl::rectangle_data&lt;int&gt;(1, 0, 21, 20));<br>
  35 &nbsp; test_data.push_back(gtl::rectangle_data&lt;int&gt;(6, 15, 16, 25));<br>
  36 <br>
  37 &nbsp; pm_type pm;<br>
  38 <br>
  39 &nbsp; //insert our test geometry into the property merge algorithm<br>
  40 &nbsp; for(unsigned int i = 0; i &lt; test_data.size(); ++i) {<br>
  41 &nbsp;&nbsp;&nbsp; pm.insert(test_data[i], i); //notice I use the index as the
  42 property value<br>
  43 &nbsp; }<br>
  44 <br>
  45 &nbsp; typedef typename lookup_polygon_set_type&lt;pm_type&gt;::type polygon_set_type;<br>
  46 &nbsp; typedef std::map&lt;std::set&lt;int&gt;, polygon_set_type&gt;
  47 property_merge_result_type;<br>
  48 <br>
  49 &nbsp; std::set&lt;int&gt; key;<br>
  50 <br>
  51 &nbsp; //There are 8 different combinations of our input geometries<br>
  52 &nbsp; //null combination is not interesting, so really 7<br>
  53 <br>
  54 &nbsp; property_merge_result_type result;<br>
  55 &nbsp; pm.merge(result);<br>
  56 <br>
  57 &nbsp; //lets enumerate boolean combinations of inputs (hold onto your hats)<br>
  58 &nbsp; for(unsigned int i = 0; i &lt; 8; ++i) {<br>
  59 &nbsp;&nbsp;&nbsp; bool bits[3] = {i &amp; 1, i &amp; 2, i &amp; 4}; //break out bit array<br>
  60 &nbsp;&nbsp;&nbsp; polygon_set_type test_set;<br>
  61 &nbsp;&nbsp;&nbsp; std::set&lt;int&gt; key;<br>
  62 &nbsp;&nbsp;&nbsp; for(unsigned int j = 0; j &lt; 3; ++j) {<br>
  63 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if(bits[j]) {<br>
  64 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; key.insert(key.end(), j);<br>
  65 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; test_set += test_data[j];<br>
  66 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br>
  67 &nbsp;&nbsp;&nbsp; }<br>
  68 &nbsp;&nbsp;&nbsp; for(unsigned int j = 0; j &lt; 3; ++j) {<br>
  69 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if(bits[j]) {<br>
  70 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; test_set *= test_data[j];<br>
  71 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br>
  72 &nbsp;&nbsp;&nbsp; }<br>
  73 &nbsp;&nbsp;&nbsp; for(unsigned int j = 0; j &lt; 3; ++j) {<br>
  74 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if(!bits[j])<br>
  75 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; test_set -= test_data[j];<br>
  76 &nbsp;&nbsp;&nbsp; }<br>
  77 &nbsp;&nbsp;&nbsp; if(test_set.empty()) {<br>
  78 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; //only the null combination should not exist<br>
  79 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; assert(i == 0);<br>
  80 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; //a combination that does not exist should not<br>
  81 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; //be present in result<br>
  82 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; assert(result.find(key) == result.end());<br>
  83 &nbsp;&nbsp;&nbsp; } else {<br>
  84 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; assert(gtl::equivalence(result[key], test_set));<br>
  85 &nbsp;&nbsp;&nbsp; }<br>
  86 &nbsp; }<br>
  87 <br>
  88 &nbsp; //Notice that we have to do O(2^n) booleans to compose the same<br>
  89 &nbsp; //result that is produced in one pass of property merge<br>
  90 &nbsp; //given n input layers (8 = 2^3 in this example)<br>
  91 }<br>
  92 <br>
  93 int main() {<br>
  94 &nbsp;
  95 test_pm&lt;gtl::property_merge_90&lt;int, int&gt; &gt;();<br>
  96 &nbsp;
  97 test_pm&lt;gtl::property_merge&lt;int, int&gt; &gt;();<br>
  98 &nbsp;
  99 return 0;<br>
 100 }<br>
 101 //Now you know how to use the manhattan and arbitrary angle property<br>
 102 //merge algorithms to perform map overlay on n layers of input geometry<br>
 103 &nbsp;</font></p>
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 105
 106 <table class="docinfo" rules="none" frame="void" id="table1">
 107         <colgroup>
 108                 <col class="docinfo-name"><col class="docinfo-content">
 109         </colgroup>
 110         <tbody vAlign="top">
 111                 <tr>
 112                         <th class="docinfo-name">Copyright:</th>
 113                         <td>Copyright © Intel Corporation 2008-2010.</td>
 114                 </tr>
 115                 <tr class="field">
 116                         <th class="docinfo-name">License:</th>
 117                         <td class="field-body">Distributed under the Boost Software License,
 118                         Version 1.0. (See accompanying file <tt class="literal">
 119                         <span class="pre">LICENSE_1_0.txt</span></tt> or copy at
 120                         <a class="reference" target="_top" href="http://www.boost.org/LICENSE_1_0.txt">
 121                         http://www.boost.org/LICENSE_1_0.txt</a>)</td>
 122                 </tr>
 123 </table>
 124
 125 </body>
 126
 127 </html>