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
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
// Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
// Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
// Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
// 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)
//
// Linestring Polygon Overlay Example
// NOTE: this example is obsolete. Boost.Geometry can now
// overlay linestrings/polygons.
// This sample will be removed in next version.
#include <fstream>
#include <iostream>
#include <string>
#include <vector>
#include <boost/geometry/geometry.hpp>
#include <boost/geometry/geometries/linestring.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/polygon.hpp>
#include <boost/geometry/geometries/adapted/c_array.hpp>
#if defined(HAVE_SVG)
# include <boost/geometry/io/svg/svg_mapper.hpp>
#endif
BOOST_GEOMETRY_REGISTER_C_ARRAY_CS(cs::cartesian);
int main(void)
{
namespace bg = boost::geometry;
using point_2d = bg::model::d2::point_xy<double>;
bg::model::linestring<point_2d> ls;
{
const double c[][2] = { {0, 1}, {2, 5}, {5, 3} };
bg::assign_points(ls, c);
}
bg::model::polygon<point_2d> p;
{
const double c[][2] = { {3, 0}, {0, 3}, {4, 5}, {3, 0} };
bg::assign_points(p, c);
}
bg::correct(p);
#if defined(HAVE_SVG)
// Create SVG-mapper
std::ofstream stream("05_b_overlay_linestring_polygon_example.svg");
bg::svg_mapper<point_2d> svg(stream, 500, 500);
// Determine extend by adding geometries
svg.add(p);
svg.add(ls);
// Map geometries
svg.map(ls, "opacity:0.6;stroke:rgb(255,0,0);stroke-width:2;");
svg.map(p, "opacity:0.6;fill:rgb(0,0,255);");
#endif
// Calculate intersection points (turn points)
using segment_ratio = bg::segment_ratio_type<point_2d>::type;
using turn_info = bg::detail::overlay::turn_info<point_2d, segment_ratio>;
std::vector<turn_info> turns;
bg::detail::get_turns::no_interrupt_policy policy;
bg::strategies::relate::services::default_strategy<bg::model::linestring<point_2d>, bg::model::polygon<point_2d>>::type strategy;
bg::get_turns<false, false, bg::detail::overlay::assign_null_policy>(ls, p, strategy, turns, policy);
std::cout << "Intersection of linestring/polygon" << std::endl;
for (turn_info const& turn : turns)
{
std::string action = "intersecting";
if (turn.operations[0].operation
== bg::detail::overlay::operation_intersection)
{
action = "entering";
}
else if (turn.operations[0].operation
== bg::detail::overlay::operation_union)
{
action = "leaving";
}
std::cout << action << " polygon at " << bg::dsv(turn.point) << std::endl;
#if defined(HAVE_SVG)
svg.map(turn.point, "fill:rgb(255,128,0);stroke:rgb(0,0,100);stroke-width:1");
svg.text(turn.point, action, "fill:rgb(0,0,0);font-family:Arial;font-size:10px");
#endif
}
return 0;
}
|
