1 // Boost.Geometry
2 // QuickBook Example
3
4 // Copyright (c) 2011-2012 Barend Gehrels, Amsterdam, the Netherlands.
5 // Copyright (c) 2015 Adam Wulkiewicz, Lodz, Poland.
6
7 // Use, modification and distribution is subject to the Boost Software License,
8 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
9 // http://www.boost.org/LICENSE_1_0.txt)
10
11 //[ring
12 //` Declaration and use of the Boost.Geometry model::ring, modelling the Ring Concept
13
14 #include <iostream>
15 #include <boost/geometry.hpp>
16 #include <boost/geometry/geometries/geometries.hpp>
17
18 namespace bg = boost::geometry;
19
main()20 int main()
21 {
22 typedef bg::model::point<double, 2, bg::cs::cartesian> point_t;
23 typedef bg::model::ring<point_t> ring_t; /*< Default parameters, clockwise, closed ring. >*/
24
25 ring_t ring1; /*< Default-construct a ring. >*/
26
27 #if !defined(BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX) \
28 && !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
29
30 ring_t ring2{{0.0, 0.0}, {0.0, 5.0}, {5.0, 5.0}, {5.0, 0.0}, {0.0, 0.0}}; /*< Construct a ring containing four points plus one closing point, using C++11 unified initialization syntax. >*/
31
32 #endif
33
34 bg::append(ring1, point_t(0.0, 0.0)); /*< Append point. >*/
35 bg::append(ring1, point_t(0.0, 5.0));
36 bg::append(ring1, point_t(5.0, 5.0));
37 bg::append(ring1, point_t(5.0, 0.0));
38 bg::append(ring1, point_t(0.0, 0.0));
39
40 double a = bg::area(ring1);
41
42 std::cout << a << std::endl;
43
44 return 0;
45 }
46
47 //]
48
49
50 //[ring_output
51 /*`
52 Output:
53 [pre
54 25
55 ]
56 */
57 //]
58