ceph/src/boost/libs/geometry/doc/src/examples/views/box_view.cpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2 // QuickBook Example
   3
   4 // Copyright (c) 2011-2012 Barend Gehrels, Amsterdam, the Netherlands.
   5
   6 // Use, modification and distribution is subject to the Boost Software License,
   7 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   8 // http://www.boost.org/LICENSE_1_0.txt)
   9
  10 //[box_view
  11 //` Shows usage of the Boost.Range compatible view on a box
  12
  13 #include <iostream>
  14
  15 #include <boost/geometry.hpp>
  16
  17
  18 int main()
  19 {
  20     typedef boost::geometry::model::box
  21         <
  22             boost::geometry::model::point<double, 2, boost::geometry::cs::cartesian>
  23         > box_type;
  24
  25     // Define the Boost.Range compatible type:
  26     typedef boost::geometry::box_view<box_type> box_view;
  27
  28     box_type box;
  29     boost::geometry::assign_values(box, 0, 0, 4, 4);
  30
  31     box_view view(box);
  32
  33     // Iterating in clockwise direction over the points of this box
  34     for (boost::range_iterator<box_view const>::type it = boost::begin(view);
  35         it != boost::end(view); ++it)
  36     {
  37         std::cout << " " << boost::geometry::dsv(*it);
  38     }
  39     std::cout << std::endl;
  40
  41     // Note that a box_view is tagged as a ring, so supports area etc.
  42     std::cout << "Area: " << boost::geometry::area(view) << std::endl;
  43
  44     return 0;
  45 }
  46
  47 //]
  48
  49
  50 //[box_view_output
  51 /*`
  52 Output:
  53 [pre
  54  (0, 0) (0, 4) (4, 4) (4, 0) (0, 0)
  55 Area: 16
  56 ]
  57 */
  58 //]