boost-react-native-bundle

<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=windows-1252"> <title>Custom Polygon</title> </head> <body> /* Copyright 2008 Intel Corporation Use, modification and distribution are subject to the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt). */ #include <boost/polygon/polygon.hpp> #include <cassert> #include <list> namespace gtl = boost::polygon; using namespace boost::polygon::operators; //first lets turn our polygon usage code into a generic //function parameterized by polygon type template <typename Polygon> void test_polygon() {   //lets construct a 10x10 rectangle shaped polygon   typedef typename gtl::polygon_traits<Polygon>::point_type Point;   Point pts[] = {gtl::construct<Point>(0, 0),   gtl::construct<Point>(10, 0),   gtl::construct<Point>(10, 10),   gtl::construct<Point>(0, 10) };   Polygon poly;   gtl::set_points(poly, pts, pts+4);   //now lets see what we can do with this polygon   assert(gtl::area(poly) == 100.0f);   assert(gtl::contains(poly, gtl::construct<Point>(5, 5)));   assert(!gtl::contains(poly, gtl::construct<Point>(15, 5)));   gtl::rectangle_data<int> rect;   assert(gtl::extents(rect, poly)); //get bounding box of poly   assert(gtl::equivalence(rect, poly)); //hey, that's slick   assert(gtl::winding(poly) == gtl::COUNTERCLOCKWISE);   assert(gtl::perimeter(poly) == 40.0f);   //add 5 to all coords of poly   gtl::convolve(poly, gtl::construct<Point>(5, 5));   //multiply all coords of poly by 2   gtl::scale_up(poly, 2);   gtl::set_points(rect, gtl::point_data<int>(10, 10),   gtl::point_data<int>(30, 30));   assert(gtl::equivalence(poly, rect)); } //Now lets declare our own polygon class //Oops, we need a point class to support our polygon, lets borrow //the CPoint example struct CPoint {   int x;   int y; }; //we have to get CPoint working with boost polygon to make our polygon //that uses CPoint working with boost polygon namespace boost { namespace polygon {   template <>   struct geometry_concept<CPoint> { typedef point_concept type; };   template <>   struct point_traits<CPoint> {     typedef int coordinate_type;     static inline coordinate_type get(const CPoint& point,     orientation_2d orient) {       if(orient == HORIZONTAL)         return point.x;       return point.y;     }   };   template <>   struct point_mutable_traits<CPoint> {     typedef int coordinate_type;     static inline void set(CPoint& point, orientation_2d orient, int value) {       if(orient == HORIZONTAL)         point.x = value;       else         point.y = value;     }     static inline CPoint construct(int x_value, int y_value) {       CPoint retval;       retval.x = x_value;       retval.y = y_value;       return retval;     }   }; } } //I'm lazy and use the stl everywhere to avoid writing my own classes //my toy polygon is a std::list<CPoint> typedef std::list<CPoint> CPolygon; //we need to specialize our polygon concept mapping in boost polygon namespace boost { namespace polygon {   //first register CPolygon as a polygon_concept type   template <>   struct geometry_concept<CPolygon>{ typedef polygon_concept type; };   template <>   struct polygon_traits<CPolygon> {     typedef int coordinate_type;     typedef CPolygon::const_iterator iterator_type;     typedef CPoint point_type;     // Get the begin iterator     static inline iterator_type begin_points(const CPolygon& t) {       return t.begin();     }     // Get the end iterator     static inline iterator_type end_points(const CPolygon& t) {       return t.end();     }     // Get the number of sides of the polygon     static inline std::size_t size(const CPolygon& t) {       return t.size();     }     // Get the winding direction of the polygon     static inline winding_direction winding(const CPolygon& t) {       return unknown_winding;     }   };   template <>   struct polygon_mutable_traits<CPolygon> {     //expects stl style iterators     template <typename iT>     static inline CPolygon& set_points(CPolygon& t,                                        iT input_begin, iT input_end) {       t.clear();       t.insert(t.end(), input_begin, input_end);       return t;     }   }; } } //now there's nothing left to do but test that our polygon //works with library interfaces int main() {   test_polygon<CPolygon>(); //woot!   return 0; }   <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"> LICENSE_1_0.txt</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>