1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
|
// 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)
//[area
//` Calculate the area of a polygon
#include <iostream>
#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/polygon.hpp>
namespace bg = boost::geometry; /*< Convenient namespace alias >*/
int main()
{
// Calculate the area of a cartesian polygon
bg::model::polygon<bg::model::d2::point_xy<double> > poly;
bg::read_wkt("POLYGON((0 0,0 7,4 2,2 0,0 0))", poly);
double area = bg::area(poly);
std::cout << "Area: " << area << std::endl;
// Calculate the area of a spherical equatorial polygon
bg::model::polygon<bg::model::point<float, 2, bg::cs::spherical_equatorial<bg::degree> > > sph_poly;
bg::read_wkt("POLYGON((0 0,0 45,45 0,0 0))", sph_poly);
area = bg::area(sph_poly);
std::cout << "Area: " << area << std::endl;
return 0;
}
//]
//[area_output
/*`
Output:
[pre
Area: 16
Area: 0.339837
]
*/
//]
|
