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| <title>Polygon Set Usage</title> |
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| <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> |
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| <col class="docinfo-name"><col class="docinfo-content"> |
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| <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> |
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