projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | <html> |
| 2 | ||
| 3 | <head> | |
| 4 | <meta http-equiv="Content-Type" content="text/html; charset=windows-1252"> | |
| 5 | <title>Polygon Set Usage</title> | |
| 6 | </head> | |
| 7 | ||
| 8 | <body> | |
| 9 | ||
| 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 <boost/polygon/polygon.hpp><br> | |
| 18 | #include <cassert><br> | |
| 19 | namespace gtl = boost::polygon;<br> | |
| 20 | using namespace boost::polygon::operators;<br><br> | |
| 21 | int main() {<br> | |
| 22 | //lets declare ourselves a polygon set<br> | |
| 23 | using namespace gtl; //because of operators<br> | |
| 24 | typedef std::vector<polygon_data<int> > PolygonSet;<br> | |
| 25 | PolygonSet ps;<br> | |
| 26 | <br> | |
| 27 | //lets put some data in<br> | |
| 28 | ps += rectangle_data<int>(0, 0, 10, 10);<br> | |
| 29 | <br> | |
| 30 | //now lets do something interesting<br> | |
| 31 | PolygonSet ps2;<br> | |
| 32 | ps2 += rectangle_data<int>(5, 5, 15, 15);<br> | |
| 33 | PolygonSet ps3;<br> | |
| 34 | assign(ps3, ps * ps2); //woah, I just felt the room flex around me<br> | |
| 35 | PolygonSet ps4;<br> | |
| 36 | ps4 += ps + ps2;<br> | |
| 37 | <br> | |
| 38 | //assert that area of result is equal to sum of areas<br> | |
| 39 | //of input geometry minus the area of overlap between inputs<br> | |
| 40 | assert(area(ps4) == area(ps) + area(ps2) - area(ps3));<br> | |
| 41 | <br> | |
| 42 | //I don't even see the code anymore, all<br> | |
| 43 | //I see is bounding box...interval...triangle<br> | |
| 44 | <br> | |
| 45 | //lets try that again in slow motion shall we?<br> | |
| 46 | assert(equivalence((ps + ps2) - (ps * ps2), ps ^ ps2));<br> | |
| 47 | <br> | |
| 48 | //hmm, subtracting the intersection from the union<br> | |
| 49 | //is equivalent to the xor, all this in one line of code,<br> | |
| 50 | //now we're programming in bullet time<br> | |
| 51 | //(by the way, xor is implemented as one pass, not | |
| 52 | composition) <br> | |
| 53 | <br> | |
| 54 | //just for fun<br> | |
| 55 | rectangle_data<int> rect;<br> | |
| 56 | assert(extents(rect, ps ^ ps2));<br> | |
| 57 | assert(area(rect) == 225);<br> | |
| 58 | assert(area(rect ^ (ps ^ ps2)) == area(rect) - area(ps ^ ps2)); <br> | |
| 59 | return 0;<br>}<br> | |
| 60 | <br>//Now you know how to use the polygon set concept with library polygons<br> | |
| 61 | </font></p> | |
| 62 | ||
| 63 | ||
| 64 | <table class="docinfo" rules="none" frame="void" id="table1"> | |
| 65 | <colgroup> | |
| 66 | <col class="docinfo-name"><col class="docinfo-content"> | |
| 67 | </colgroup> | |
| 68 | <tbody vAlign="top"> | |
| 69 | <tr> | |
| 70 | <th class="docinfo-name">Copyright:</th> | |
| 71 |