86 lines
3.2 KiB
HTML
86 lines
3.2 KiB
HTML
<html>
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
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<title>Polygon Set Usage</title>
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</head>
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<body>
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<p><font face="Courier New">/*<br>
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Copyright 2008 Intel Corporation<br>
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<br>
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Use, modification and distribution are subject to the Boost Software License,<br>
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Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at<br>
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http://www.boost.org/LICENSE_1_0.txt).<br>
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*/<br>
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#include <boost/polygon/polygon.hpp><br>
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#include <cassert><br>
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namespace gtl = boost::polygon;<br>
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using namespace boost::polygon::operators;<br><br>
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int main() {<br>
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//lets declare ourselves a polygon set<br>
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using namespace gtl; //because of operators<br>
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typedef std::vector<polygon_data<int> > PolygonSet;<br>
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PolygonSet ps;<br>
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<br>
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//lets put some data in<br>
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ps += rectangle_data<int>(0, 0, 10, 10);<br>
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<br>
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//now lets do something interesting<br>
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PolygonSet ps2;<br>
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ps2 += rectangle_data<int>(5, 5, 15, 15);<br>
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PolygonSet ps3;<br>
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assign(ps3, ps * ps2); //woah, I just felt the room flex around me<br>
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PolygonSet ps4;<br>
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ps4 += ps + ps2;<br>
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<br>
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//assert that area of result is equal to sum of areas<br>
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//of input geometry minus the area of overlap between inputs<br>
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assert(area(ps4) == area(ps) + area(ps2) - area(ps3));<br>
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<br>
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//I don't even see the code anymore, all<br>
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//I see is bounding box...interval...triangle<br>
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<br>
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//lets try that again in slow motion shall we?<br>
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assert(equivalence((ps + ps2) - (ps * ps2), ps ^ ps2));<br>
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<br>
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//hmm, subtracting the intersection from the union<br>
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//is equivalent to the xor, all this in one line of code,<br>
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//now we're programming in bullet time<br>
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//(by the way, xor is implemented as one pass, not
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composition) <br>
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<br>
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//just for fun<br>
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rectangle_data<int> rect;<br>
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assert(extents(rect, ps ^ ps2));<br>
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assert(area(rect) == 225);<br>
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assert(area(rect ^ (ps ^ ps2)) == area(rect) - area(ps ^ ps2)); <br>
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return 0;<br>}<br>
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<br>//Now you know how to use the polygon set concept with library polygons<br>
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</font></p>
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<table class="docinfo" rules="none" frame="void" id="table1">
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<colgroup>
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<col class="docinfo-name"><col class="docinfo-content">
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</colgroup>
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<tbody vAlign="top">
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<tr>
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<th class="docinfo-name">Copyright:</th>
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<td>Copyright <20> Intel Corporation 2008-2010.</td>
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</tr>
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<tr class="field">
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<th class="docinfo-name">License:</th>
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<td class="field-body">Distributed under the Boost Software License,
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Version 1.0. (See accompanying file <tt class="literal">
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<span class="pre">LICENSE_1_0.txt</span></tt> or copy at
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<a class="reference" target="_top" href="http://www.boost.org/LICENSE_1_0.txt">
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http://www.boost.org/LICENSE_1_0.txt</a>)</td>
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</tr>
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</table>
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</body>
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</html>
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