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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> |
| #include <list><br> |
| namespace gtl = boost::polygon;<br> |
| using namespace boost::polygon::operators;<br><br> |
| //first lets turn our polygon usage code into a generic<br> |
| //function parameterized by polygon type<br> |
| template <typename Polygon><br> |
| void test_polygon() {<br> |
| //lets construct a 10x10 rectangle shaped polygon<br> |
| typedef typename gtl::polygon_traits<Polygon>::point_type Point;<br> |
| Point pts[] = {gtl::construct<Point>(0, 0),<br> |
| gtl::construct<Point>(10, 0),<br> |
| gtl::construct<Point>(10, 10),<br> |
| gtl::construct<Point>(0, 10) };<br> |
| Polygon poly;<br> |
| gtl::set_points(poly, pts, pts+4);<br> |
| <br> |
| //now lets see what we can do with this polygon<br> |
| assert(gtl::area(poly) == 100.0f);<br> |
| assert(gtl::contains(poly, gtl::construct<Point>(5, 5)));<br> |
| assert(!gtl::contains(poly, gtl::construct<Point>(15, 5)));<br> |
| gtl::rectangle_data<int> rect;<br> |
| assert(gtl::extents(rect, poly)); //get bounding box of poly<br> |
| assert(gtl::equivalence(rect, poly)); //hey, that's slick<br> |
| assert(gtl::winding(poly) == gtl::COUNTERCLOCKWISE);<br> |
| assert(gtl::perimeter(poly) == 40.0f);<br> |
| <br> |
| //add 5 to all coords of poly<br> |
| gtl::convolve(poly, gtl::construct<Point>(5, 5));<br> |
| //multiply all coords of poly by 2<br> |
| gtl::scale_up(poly, 2);<br> |
| gtl::set_points(rect, gtl::point_data<int>(10, 10),<br> |
| gtl::point_data<int>(30, 30));<br> |
| assert(gtl::equivalence(poly, rect));<br> |
| }<br> |
| <br> |
| //Now lets declare our own polygon class<br> |
| //Oops, we need a point class to support our polygon, lets borrow<br> |
| //the CPoint example<br> |
| struct CPoint {<br> |
| int x;<br> |
| int y;<br> |
| };<br> |
| <br> |
| //we have to get CPoint working with boost polygon to make our polygon<br> |
| //that uses CPoint working with boost polygon<br> |
| namespace boost { namespace polygon {<br> |
| template <><br> |
| struct geometry_concept<CPoint> { typedef point_concept type; };<br> |
| template <><br> |
| struct point_traits<CPoint> {<br> |
| typedef int coordinate_type;<br> |
| <br> |
| static inline coordinate_type get(const CPoint& point, <br> |
| orientation_2d orient) {<br> |
| if(orient == HORIZONTAL)<br> |
| return point.x;<br> |
| return point.y;<br> |
| }<br> |
| };<br> |
| <br> |
| template <><br> |
| struct point_mutable_traits<CPoint> {<br> |
| static inline void set(CPoint& point, orientation_2d orient, |
| int value) {<br> |
| if(orient == HORIZONTAL)<br> |
| point.x = value;<br> |
| else<br> |
| point.y = value;<br> |
| }<br> |
| static inline CPoint construct(int x_value, int y_value) {<br> |
| CPoint retval;<br> |
| retval.x = x_value;<br> |
| retval.y = y_value; <br> |
| return retval;<br> |
| }<br> |
| };<br> |
| } }<br> |
| <br> |
| //I'm lazy and use the stl everywhere to avoid writing my own classes<br> |
| //my toy polygon is a std::list<CPoint><br> |
| typedef std::list<CPoint> CPolygon;<br> |
| <br> |
| //we need to specialize our polygon concept mapping in boost polygon<br> |
| namespace boost { namespace polygon {<br> |
| //first register CPolygon as a polygon_concept type<br> |
| template <><br> |
| struct geometry_concept<CPolygon>{ typedef polygon_concept type; };<br> |
| <br> |
| template <><br> |
| struct polygon_traits<CPolygon> {<br> |
| typedef int coordinate_type;<br> |
| typedef CPolygon::const_iterator iterator_type;<br> |
| typedef CPoint point_type;<br> |
| <br> |
| // Get the begin iterator<br> |
| static inline iterator_type begin_points(const CPolygon& t) {<br> |
| return t.begin();<br> |
| }<br> |
| <br> |
| // Get the end iterator<br> |
| static inline iterator_type end_points(const CPolygon& t) {<br> |
| return t.end();<br> |
| }<br> |
| <br> |
| // Get the number of sides of the polygon<br> |
| static inline std::size_t size(const CPolygon& t) {<br> |
| return t.size();<br> |
| }<br> |
| <br> |
| // Get the winding direction of the polygon<br> |
| static inline winding_direction winding(const CPolygon& t) {<br> |
| return unknown_winding;<br> |
| }<br> |
| };<br> |
| <br> |
| template <><br> |
| struct polygon_mutable_traits<CPolygon> {<br> |
| //expects stl style iterators<br> |
| template <typename iT><br> |
| static inline CPolygon& set_points(CPolygon& t, <br> |
| |
| iT input_begin, iT input_end) {<br> |
| t.clear();<br> |
| t.insert(t.end(), input_begin, input_end);<br> |
| return t;<br> |
| }<br> |
| <br> |
| };<br> |
| } }<br> |
| <br> |
| //now there's nothing left to do but test that our polygon<br> |
| //works with library interfaces<br> |
| int main() {<br> |
| test_polygon<CPolygon>(); //woot!<br> |
| return 0;<br> |
| }<br> |
| </font></p> |
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| <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> |
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