#### /Src/Dependencies/Boost/libs/geometry/example/c06_custom_polygon_example.cpp

C++ | 141 lines | 86 code | 33 blank | 22 comment | 0 complexity | ac68ada55b8325c08f7ff92eaee2a396 MD5 | raw file
```  1// Boost.Geometry (aka GGL, Generic Geometry Library)
2
3// Copyright (c) 2007-2011 Barend Gehrels, Amsterdam, the Netherlands.
4// Copyright (c) 2008-2011 Bruno Lalande, Paris, France.
5// Copyright (c) 2009-2011 Mateusz Loskot, London, UK.
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
10//
11// Custom Polygon Example
12#include <iostream>
13
14#include <boost/geometry/geometry.hpp>
15
16#include <boost/geometry/geometries/register/point.hpp>
17#include <boost/geometry/geometries/register/ring.hpp>
18
19
20struct my_point
21{
22    my_point(double an_x = 0, double an_y = 0)
23        : x(an_x)
24        , y(an_y)
25    {}
26
27    double x, y;
28};
29
30struct my_ring : std::deque<my_point>
31{};
32
33// Define a struct of a polygon, having always two holes
34// (of course this can be implemented differently, usually
35// with a vector or deque, but it is just an exampe)
36struct my_polygon
37{
38    // required for a polygon: an outer ring...
39    my_ring boundary;
40    // ... and a Boost.Range compatible inner ring collection
41    boost::array<my_ring, 2> holes;
42
43    // just for the sample
44    std::string name;
45
46    my_polygon(std::string const& n = "") : name(n) {}
47};
48
49
50// We can conveniently use macro's to register point and ring
51BOOST_GEOMETRY_REGISTER_POINT_2D(my_point, double, cs::cartesian, x, y)
52BOOST_GEOMETRY_REGISTER_RING(my_ring)
53
54
55
56// There is currently no registration macro for polygons
57// and besides that a boost::array<T,N> in a macro would
58// be very specific, so we show it "by hand":
59namespace boost { namespace geometry { namespace traits
60{
61
62template<> struct tag<my_polygon> { typedef polygon_tag type; };
63template<> struct ring_const_type<my_polygon> { typedef my_ring const& type; };
64template<> struct ring_mutable_type<my_polygon> { typedef my_ring& type; };
65
66template<> struct interior_const_type<my_polygon>
67{
68    typedef boost::array<my_ring, 2> const& type;
69};
70
71template<> struct interior_mutable_type<my_polygon>
72{
73    typedef boost::array<my_ring, 2>& type;
74};
75
76template<> struct exterior_ring<my_polygon>
77{
78    static my_ring& get(my_polygon& p)
79    {
80        return p.boundary;
81    }
82
83    static my_ring const& get(my_polygon const& p)
84    {
85        return p.boundary;
86    }
87};
88
89template<> struct interior_rings<my_polygon>
90{
91    typedef boost::array<my_ring, 2> holes_type;
92
93    static holes_type& get(my_polygon& p)
94    {
95        return p.holes;
96    }
97
98    static holes_type const& get(my_polygon const& p)
99    {
100        return p.holes;
101    }
102};
103
104}}} // namespace boost::geometry::traits
105
106
107
108int main()
109{
110    my_polygon p1("my polygon");
111
112    // Fill it the my-way, triangle
113    p1.boundary.push_back(my_point(2, 0));
114    p1.boundary.push_back(my_point(1, 5));
115    p1.boundary.push_back(my_point(7, 6));
116    p1.boundary.push_back(my_point(2, 0));
117
118    // Triangle
119    p1.holes[0].push_back(my_point(2, 1));
120    p1.holes[0].push_back(my_point(2.4, 2));
121    p1.holes[0].push_back(my_point(1.9, 2));
122    p1.holes[0].push_back(my_point(2, 1));
123
124    // Box
125    p1.holes[1].push_back(my_point(3, 3));
126    p1.holes[1].push_back(my_point(4, 3));
127    p1.holes[1].push_back(my_point(4, 4));
128    p1.holes[1].push_back(my_point(3, 4));
129    p1.holes[1].push_back(my_point(3, 3));
130
131    std::cout << "Representation of " << p1.name << ": "
132        << boost::geometry::dsv(p1) << std::endl;
133    std::cout << "Area of " << p1.name << ": "
134        << boost::geometry::area(p1) << std::endl;
135    std::cout << "Perimeter of " << p1.name << ": "
136        << boost::geometry::perimeter(p1) << std::endl;
137    std::cout << "Centroid of " << p1.name << ": "
138        << boost::geometry::dsv(boost::geometry::return_centroid<my_point>(p1)) << std::endl;
139
140    return 0;
141}
```