| // Boost.Geometry (aka GGL, Generic Geometry Library) |
| // QuickBook Example |
| |
| // Copyright (c) 2011-2012 Barend Gehrels, Amsterdam, the Netherlands. |
| |
| // Use, modification and distribution is subject to the Boost Software License, |
| // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| |
| //[assign_points |
| //` Shows usage of Boost.Geometry's assign, Boost.Assign, and Boost.Range to assign ranges of a linestring |
| |
| #include <iostream> |
| |
| #include <boost/geometry.hpp> |
| #include <boost/geometry/geometries/linestring.hpp> |
| #include <boost/geometry/geometries/adapted/boost_tuple.hpp> |
| |
| #include <boost/assign.hpp> |
| #include <boost/geometry/geometries/adapted/boost_range/filtered.hpp> |
| |
| BOOST_GEOMETRY_REGISTER_BOOST_TUPLE_CS(cs::cartesian) |
| |
| template <typename T> |
| struct x_between |
| { |
| x_between(T a, T b) |
| : fa(a), fb(b) |
| {} |
| |
| template <typename P> |
| bool operator()(P const& p) const |
| { |
| return boost::geometry::get<0>(p) >= fa |
| && boost::geometry::get<0>(p) <= fb; |
| } |
| private : |
| T fa, fb; |
| }; |
| |
| |
| int main() |
| { |
| using namespace boost::assign; |
| |
| typedef boost::geometry::model::linestring<boost::tuple<int, int> > ls; |
| |
| ls line1, line2, line3; |
| |
| line1 = tuple_list_of(0, 0)(2, 3)(4, 0)(6, 3)(8, 0)(10, 3)(12, 0); /*< tuple_list_of is part of Boost.Assign and can be used for Boost.Geometry if points are tuples >*/ |
| boost::geometry::assign_points(line2, tuple_list_of(0, 0)(2, 2)(4, 0)(6, 2)(8, 0)); /*< tuple_list_of delivers a range and can therefore be used in boost::geometry::assign >*/ |
| boost::geometry::assign_points(line3, line1 | boost::adaptors::filtered(x_between<int>(4, 8))); /*< Boost.Range adaptors can also be used in boost::geometry::assign >*/ |
| |
| std::cout << "line 1: " << boost::geometry::dsv(line1) << std::endl; |
| std::cout << "line 2: " << boost::geometry::dsv(line2) << std::endl; |
| std::cout << "line 3: " << boost::geometry::dsv(line3) << std::endl; |
| |
| return 0; |
| } |
| |
| //] |
| |
| |
| //[assign_points_output |
| /*` |
| Output: |
| [pre |
| line 1: ((0, 0), (2, 3), (4, 0), (6, 3), (8, 0), (10, 3), (12, 0)) |
| line 2: ((0, 0), (2, 2), (4, 0), (6, 2), (8, 0)) |
| line 3: ((4, 0), (6, 3), (8, 0)) |
| ] |
| */ |
| //] |