ceph/src/boost/libs/geometry/example/04_boost_example.cpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4 // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
   5 // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
   6
   7 // Use, modification and distribution is subject to the Boost Software License,
   8 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   9 // http://www.boost.org/LICENSE_1_0.txt)
  10 //
  11 // Example combining Boost.Geometry with Boost.Assign and Boost.Range and Boost.Tuple
  12
  13 #include <iostream>
  14
  15 #include <boost/geometry/geometry.hpp>
  16 #include <boost/geometry/geometries/point_xy.hpp>
  17 #include <boost/geometry/geometries/linestring.hpp>
  18 #include <boost/geometry/geometries/polygon.hpp>
  19 #include <boost/geometry/geometries/adapted/boost_tuple.hpp>
  20
  21 #include <boost/assign.hpp>
  22
  23 BOOST_GEOMETRY_REGISTER_BOOST_TUPLE_CS(cs::cartesian);
  24
  25
  26 int main(void)
  27 {
  28     using namespace boost::geometry;
  29     using namespace boost::assign;
  30
  31     {
  32         typedef model::d2::point_xy<double> point;
  33         typedef model::polygon<point> polygon;
  34         typedef model::linestring<point> linestring;
  35
  36         // Boost.Assign automatically works for linestring, rings, multi-geometries
  37         // It works because these are std:: containers
  38
  39         // Using Boost.Assign operator +=
  40         linestring ls1;
  41         ls1 += point(1,2);
  42         ls1 += point(3,4), point(5,6), point(7,8);
  43         std::cout << dsv(ls1) << std::endl;
  44
  45         // Using Boost.Assign operator()
  46         linestring ls2;
  47         push_back(ls2)(point(1, 2))(point(3, 4));
  48         std::cout << dsv(ls2) << std::endl;
  49
  50         // Using Boost.Assign list_of
  51         linestring ls3 = list_of(point(1,2))(point(3,4));
  52         std::cout << dsv(ls3) << std::endl;
  53
  54         // Using Boost.Assign + Boost.Range
  55         linestring ls4;
  56         push_back(ls4)(point(0, 0)).range(ls2).range(ls3);
  57         std::cout << dsv(ls4) << std::endl;
  58
  59         // For a ring, it is similar to a linestring.
  60         // For a multi-point or multi-linestring, it is also similar
  61         // For a polygon, take the exterior ring or one of the interiors
  62         polygon p;
  63         push_back(exterior_ring(p))
  64             (point(0, 0))
  65             (point(0, 2))
  66             (point(2, 2))
  67             (point(2, 0))
  68             (point(0, 0))
  69             ;
  70
  71         std::cout << dsv(p) << std::endl;
  72     }
  73
  74     {
  75         // It is convenient to combine Boost.Assign on a geometry (e.g. polygon) with tuples.
  76         typedef model::polygon<boost::tuple<double,double> > polygon;
  77
  78         polygon p;
  79         exterior_ring(p) = tuple_list_of(0, 0)(0, 5)(5, 5)(5, 0)(0, 0);
  80
  81         std::cout << dsv(p) << std::endl;
  82
  83         // And let it work on the interior_rings as well
  84         push_back(interior_rings(p))
  85             (tuple_list_of(1, 1)(2, 1)(2, 2)(1, 2)(1, 1))
  86             (tuple_list_of(3, 3)(4, 3)(4, 4)(3, 4)(3, 3))
  87             ;
  88
  89         std::cout << "Area of " << dsv(p) << " is " << area(p) << std::endl;
  90     }
  91
  92
  93     return 0;
  94 }