ceph/src/boost/libs/geometry/doc/src/examples/algorithms/clear.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 //[clear
  11 //` Shows how to clear a ring or polygon
  12
  13 #include <iostream>
  14
  15 #include <boost/geometry.hpp>
  16 #include <boost/geometry/geometries/polygon.hpp>
  17 #include <boost/geometry/geometries/ring.hpp>
  18 #include <boost/geometry/geometries/adapted/boost_tuple.hpp>
  19
  20 BOOST_GEOMETRY_REGISTER_BOOST_TUPLE_CS(cs::cartesian)
  21
  22 #include <boost/assign.hpp>
  23
  24 int main()
  25 {
  26     using boost::assign::tuple_list_of;
  27
  28     typedef boost::tuple<float, float> point;
  29     typedef boost::geometry::model::polygon<point> polygon;
  30     typedef boost::geometry::model::ring<point> ring;
  31
  32     polygon poly;
  33
  34     // Fill the polygon (using its own methods + Boost.Assign)
  35     poly.outer() = tuple_list_of(0, 0)(0, 9)(10, 10)(0, 0);
  36     poly.inners().push_back(tuple_list_of(1, 2)(4, 6)(2, 8)(1, 2));
  37
  38     std::cout << boost::geometry::dsv(poly) << std::endl;
  39     boost::geometry::clear(poly);
  40     std::cout << boost::geometry::dsv(poly) << std::endl;
  41
  42     // Create a ring using Boost.Assign
  43     ring r = tuple_list_of(0, 0)(0, 9)(8, 8)(0, 0);
  44
  45     std::cout << boost::geometry::dsv(r) << std::endl;
  46     boost::geometry::clear(r);
  47     std::cout << boost::geometry::dsv(r) << std::endl;
  48
  49     return 0;
  50 }
  51
  52 //]
  53
  54
  55 //[clear_output
  56 /*`
  57 Output:
  58 [pre
  59 (((0, 0), (0, 10), (11, 11), (0, 0)), ((0, 0), (0, 10), (11, 11), (0, 0)))
  60 (())
  61 ((0, 0), (0, 9), (8, 8), (0, 0))
  62 ()
  63 ]
  64 */
  65 //]