// 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)) ] */ //]