ceph/src/boost/libs/geometry/doc/src/examples/strategies/buffer_distance_asymmetric.cpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2 // QuickBook Example
   3
   4 // Copyright (c) 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_distance_asymmetric
  11 //` Shows how the distance_asymmetric strategy can be used as a DistanceStrategy to create asymmetric buffers
  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 boost::geometry::model::d2::point_xy<double> point;
  21     typedef boost::geometry::model::linestring<point> linestring;
  22     typedef boost::geometry::model::polygon<point> polygon;
  23
  24     // Declare the asymmetric distance strategy
  25     boost::geometry::strategy::buffer::distance_asymmetric<double> distance_strategy(1.0, 0.5);
  26
  27     // Declare other strategies
  28     boost::geometry::strategy::buffer::side_straight side_strategy;
  29     boost::geometry::strategy::buffer::join_round join_strategy;
  30     boost::geometry::strategy::buffer::end_round end_strategy;
  31     boost::geometry::strategy::buffer::point_circle point_strategy;
  32
  33     // Declare/fill a multi linestring
  34     boost::geometry::model::multi_linestring<linestring> ml;
  35     boost::geometry::read_wkt("MULTILINESTRING((3 5,5 10,7 5),(7 7,11 10,15 7,19 10))", ml);
  36
  37     // Create the buffered geometry with left/right a different distance
  38     boost::geometry::model::multi_polygon<polygon> result;
  39     boost::geometry::buffer(ml, result,
  40                 distance_strategy, side_strategy,
  41                 join_strategy, end_strategy, point_strategy);
  42     /*<-*/ create_svg_buffer("buffer_distance_asymmetric.svg", ml, result); /*->*/
  43
  44     return 0;
  45 }
  46
  47 //]
  48