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- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
- <title>Polygon Set Usage</title>
- </head>
- <body>
- <p><font face="Courier New">/*<br>
- Copyright 2008 Intel Corporation<br>
- <br>
- Use, modification and distribution are subject to the Boost Software License,<br>
- Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at<br>
- http://www.boost.org/LICENSE_1_0.txt).<br>
- */<br>
- #include <boost/polygon/polygon.hpp><br>
- #include <cassert><br>
- namespace gtl = boost::polygon;<br>
- using namespace boost::polygon::operators;<br><br>
- int main() {<br>
- //lets declare ourselves a polygon set<br>
- using namespace gtl; //because of operators<br>
- typedef std::vector<polygon_data<int> > PolygonSet;<br>
- PolygonSet ps;<br>
- <br>
- //lets put some data in<br>
- ps += rectangle_data<int>(0, 0, 10, 10);<br>
- <br>
- //now lets do something interesting<br>
- PolygonSet ps2;<br>
- ps2 += rectangle_data<int>(5, 5, 15, 15);<br>
- PolygonSet ps3;<br>
- assign(ps3, ps * ps2); //woah, I just felt the room flex around me<br>
- PolygonSet ps4;<br>
- ps4 += ps + ps2;<br>
- <br>
- //assert that area of result is equal to sum of areas<br>
- //of input geometry minus the area of overlap between inputs<br>
- assert(area(ps4) == area(ps) + area(ps2) - area(ps3));<br>
- <br>
- //I don't even see the code anymore, all<br>
- //I see is bounding box...interval...triangle<br>
- <br>
- //lets try that again in slow motion shall we?<br>
- assert(equivalence((ps + ps2) - (ps * ps2), ps ^ ps2));<br>
- <br>
- //hmm, subtracting the intersection from the union<br>
- //is equivalent to the xor, all this in one line of code,<br>
- //now we're programming in bullet time<br>
- //(by the way, xor is implemented as one pass, not
- composition) <br>
- <br>
- //just for fun<br>
- rectangle_data<int> rect;<br>
- assert(extents(rect, ps ^ ps2));<br>
- assert(area(rect) == 225);<br>
- assert(area(rect ^ (ps ^ ps2)) == area(rect) - area(ps ^ ps2)); <br>
- return 0;<br>}<br>
- <br>//Now you know how to use the polygon set concept with library polygons<br>
- </font></p>
- <table class="docinfo" rules="none" frame="void" id="table1">
- <colgroup>
- <col class="docinfo-name"><col class="docinfo-content">
- </colgroup>
- <tbody vAlign="top">
- <tr>
- <th class="docinfo-name">Copyright:</th>
- <td>Copyright © Intel Corporation 2008-2010.</td>
- </tr>
- <tr class="field">
- <th class="docinfo-name">License:</th>
- <td class="field-body">Distributed under the Boost Software License,
- Version 1.0. (See accompanying file <tt class="literal">
- <span class="pre">LICENSE_1_0.txt</span></tt> or copy at
- <a class="reference" target="_top" href="http://www.boost.org/LICENSE_1_0.txt">
- http://www.boost.org/LICENSE_1_0.txt</a>)</td>
- </tr>
- </table>
- </body>
- </html>
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