boost-react-native-bundle

<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=windows-1252"> <title>Custom Polygon Set</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 <list> #include <time.h> #include <cassert> #include <deque> #include <iostream> namespace gtl = boost::polygon; using namespace boost::polygon::operators; //once again we make our usage of the library generic //and parameterize it on the polygon set type template <typename PolygonSet> void test_polygon_set() {   using namespace gtl;   PolygonSet ps;   ps += rectangle_data<int>(0, 0, 10, 10);   PolygonSet ps2;   ps2 += rectangle_data<int>(5, 5, 15, 15);   PolygonSet ps3;   assign(ps3, ps * ps2);   PolygonSet ps4;   ps4 += ps + ps2;   assert(area(ps4) == area(ps) + area(ps2) - area(ps3));   assert(equivalence((ps + ps2) - (ps * ps2), ps ^ ps2));   rectangle_data<int> rect;   assert(extents(rect, ps ^ ps2));   assert(area(rect) == 225);   assert(area(rect ^ (ps ^ ps2)) == area(rect) - area(ps ^ ps2)); } //first thing is first, lets include all the code from previous examples //the CPoint example struct CPoint {   int x;   int y; }; 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;     }   }; } } //the CPolygon example 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();       while(input_begin != input_end) {         t.push_back(CPoint());         gtl::assign(t.back(), *input_begin);         ++input_begin;       }       return t;     }   }; } } //OK, finally we get to declare our own polygon set type typedef std::deque<CPolygon> CPolygonSet; //deque isn't automatically a polygon set in the library //because it is a standard container there is a shortcut //for mapping it to polygon set concept, but I'll do it //the long way that you would use in the general case. namespace boost { namespace polygon {   //first we register CPolygonSet as a polygon set   template <>   struct geometry_concept<CPolygonSet> { typedef polygon_set_concept type; };   //next we map to the concept through traits   template <>   struct polygon_set_traits<CPolygonSet> {     typedef int coordinate_type;     typedef CPolygonSet::const_iterator iterator_type;     typedef CPolygonSet operator_arg_type;     static inline iterator_type begin(const CPolygonSet& polygon_set) {       return polygon_set.begin();     }     static inline iterator_type end(const CPolygonSet& polygon_set) {       return polygon_set.end();     }     //don't worry about these, just return false from them     static inline bool clean(const CPolygonSet& polygon_set) { return false; }     static inline bool sorted(const CPolygonSet& polygon_set) { return false; }   };   template <>   struct polygon_set_mutable_traits<CPolygonSet> {     template <typename input_iterator_type>     static inline void set(CPolygonSet& polygon_set, input_iterator_type input_begin, input_iterator_type input_end) {       polygon_set.clear();       //this is kind of cheesy. I am copying the unknown input geometry       //into my own polygon set and then calling get to populate the       //deque       polygon_set_data<int> ps;       ps.insert(input_begin, input_end);       ps.get(polygon_set);       //if you had your own odd-ball polygon set you would probably have       //to iterate through each polygon at this point and do something       //extra     }   }; } } int main() {   long long c1 = clock();   for(int i = 0; i < 1000; ++i)     test_polygon_set<CPolygonSet>();   long long c2 = clock();   for(int i = 0; i < 1000; ++i)     test_polygon_set<gtl::polygon_set_data<int> >();   long long c3 = clock();   long long diff1 = c2 - c1;   long long diff2 = c3 - c2;   if(diff1 > 0 && diff2)     std::cout << "library polygon_set_data is " << float(diff1)/float(diff2) << "X faster than custom polygon set deque of CPolygon" << std::endl;   else     std::cout << "operation was too fast" << std::endl;   return 0; } //Now you know how to map your own data type to polygon set concept //Now you also know how to make your application code that operates on geometry //data type agnostic from point through polygon set   <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>