ceph/src/boost/libs/geometry/doc/src/examples/algorithms/buffer_with_strategies.cpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2 // QuickBook Example
   3
   4 // Copyright (c) 2013, 2014 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 //[buffer_with_strategies
  11 //` Shows how the buffer algorithm can be used to create a buffer of a linestring, a multi point, a multi polygon
  12
  13 #include <boost/geometry.hpp>
  14 #include <boost/geometry/geometries/point_xy.hpp>
  15 #include <boost/geometry/geometries/geometries.hpp>
  16 /*<-*/ #include "../examples_utils/create_svg_buffer.hpp" /*->*/
  17
  18 int main()
  19 {
  20     typedef double coordinate_type;
  21     typedef boost::geometry::model::d2::point_xy<coordinate_type> point;
  22     typedef boost::geometry::model::polygon<point> polygon;
  23
  24     // Declare strategies
  25     const double buffer_distance = 1.0;
  26     const int points_per_circle = 36;
  27     boost::geometry::strategy::buffer::distance_symmetric<coordinate_type> distance_strategy(buffer_distance);
  28     boost::geometry::strategy::buffer::join_round join_strategy(points_per_circle);
  29     boost::geometry::strategy::buffer::end_round end_strategy(points_per_circle);
  30     boost::geometry::strategy::buffer::point_circle circle_strategy(points_per_circle);
  31     boost::geometry::strategy::buffer::side_straight side_strategy;
  32
  33     // Declare output
  34     boost::geometry::model::multi_polygon<polygon> result;
  35
  36     // Declare/fill a linestring
  37     boost::geometry::model::linestring<point> ls;
  38     boost::geometry::read_wkt("LINESTRING(0 0,4 5,7 4,10 6)", ls);
  39
  40     // Create the buffer of a linestring
  41     boost::geometry::buffer(ls, result,
  42                 distance_strategy, side_strategy,
  43                 join_strategy, end_strategy, circle_strategy);
  44     /*<-*/ create_svg_buffer("buffer_linestring.svg", ls, result); /*->*/
  45
  46     // Declare/fill a multi point
  47     boost::geometry::model::multi_point<point> mp;
  48     boost::geometry::read_wkt("MULTIPOINT((3 3),(4 4),(6 2))", mp);
  49
  50     // Create the buffer of a multi point
  51     boost::geometry::buffer(mp, result,
  52                 distance_strategy, side_strategy,
  53                 join_strategy, end_strategy, circle_strategy);
  54     /*<-*/ create_svg_buffer("buffer_multi_point.svg", mp, result); /*->*/
  55
  56     // Declare/fill a multi_polygon
  57     boost::geometry::model::multi_polygon<polygon> mpol;
  58     boost::geometry::read_wkt("MULTIPOLYGON(((0 1,2 5,5 3,0 1)),((1 1,5 2,5 0,1 1)))", mpol);
  59
  60     // Create the buffer of a multi polygon
  61     boost::geometry::buffer(mpol, result,
  62                 distance_strategy, side_strategy,
  63                 join_strategy, end_strategy, circle_strategy);
  64     /*<-*/ create_svg_buffer("buffer_multi_polygon.svg", mpol, result); /*->*/
  65
  66     return 0;
  67 }
  68
  69 //]
  70