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
main()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
49