/Src/Dependencies/Boost/libs/geometry/doc/src/examples/algorithms/sym_difference.cpp

C++ | 80 lines | 30 code | 18 blank | 32 comment | 0 complexity | 87946364f7de4247c38707bb02f7120d MD5 | raw file
``` 1// Boost.Geometry (aka GGL, Generic Geometry Library)
2// QuickBook Example
3
4// Copyright (c) 2011 Barend Gehrels, Amsterdam, the Netherlands.
5
6// Use, modification and distribution is subject to the Boost Software License,
7// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
9
10//[sym_difference
11//` Shows how to calculate the symmetric difference (XOR) of two polygons
12
13#include <iostream>
14
15#include <boost/geometry.hpp>
16#include <boost/geometry/geometries/polygon.hpp>
17#include <boost/geometry/geometries/point_xy.hpp>
18#include <boost/geometry/multi/geometries/multi_polygon.hpp>
19#include <boost/geometry/domains/gis/io/wkt/wkt.hpp>
20
21#include <boost/foreach.hpp>
22/*<-*/ #include "create_svg_overlay.hpp" /*->*/
23
24int main()
25{
26    typedef boost::geometry::model::polygon<boost::geometry::model::d2::point_xy<double> > polygon;
27
28    polygon green, blue;
29
31        "POLYGON((2 1.3,2.4 1.7,2.8 1.8,3.4 1.2,3.7 1.6,3.4 2,4.1 3,5.3 2.6,5.4 1.2,4.9 0.8,2.9 0.7,2 1.3)"
32            "(4.0 2.0, 4.2 1.4, 4.8 1.9, 4.4 2.2, 4.0 2.0))", green);
33
35        "POLYGON((4.0 -0.5 , 3.5 1.0 , 2.0 1.5 , 3.5 2.0 , 4.0 3.5 , 4.5 2.0 , 6.0 1.5 , 4.5 1.0 , 4.0 -0.5))", blue);
36
37    boost::geometry::model::multi_polygon<polygon> multi;
38
39    boost::geometry::sym_difference(green, blue, multi);
40
41    std::cout
42        << "green XOR blue:" << std::endl
43        << "total: " << boost::geometry::area(multi) << std::endl;
44    int i = 0;
45    BOOST_FOREACH(polygon const& p, multi)
46    {
47        std::cout << i++ << ": " << boost::geometry::area(p) << std::endl;
48    }
49
50    /*<-*/ create_svg("sym_difference.svg", green, blue, multi); /*->*/
51    return 0;
52}
53
54//]
55
56
57//[sym_difference_output
58/*`
59Output:
60[pre
61green XOR blue:
62total: 3.1459
630: 0.02375
641: 0.542951
652: 0.0149697
663: 0.226855
674: 0.839424
685: 0.525154
696: 0.015
707: 0.181136
718: 0.128798
729: 0.340083
7310: 0.307778
74
75[\$img/algorithms/sym_difference.png]
76
77]
78*/
79//]
80
```