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

  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
  9// http://www.boost.org/LICENSE_1_0.txt)
 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}