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
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
// Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2007-2014 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)
#ifndef BOOST_GEOMETRY_GEOMETRY_POLICIES_RELATE_INTERSECTION_RATIOS_HPP
#define BOOST_GEOMETRY_GEOMETRY_POLICIES_RELATE_INTERSECTION_RATIOS_HPP
#include <algorithm>
#include <string>
#include <boost/concept_check.hpp>
#include <boost/numeric/conversion/cast.hpp>
#include <boost/geometry/algorithms/detail/assign_indexed_point.hpp>
#include <boost/geometry/core/access.hpp>
#include <boost/geometry/strategies/side_info.hpp>
namespace boost { namespace geometry
{
namespace policies { namespace relate
{
/*!
\brief Policy returning segment ratios
\note Template argument FractionType should be a fraction_type<SegmentRatio>
*/
template
<
typename FractionType
>
struct segments_intersection_ratios
{
typedef FractionType return_type;
template
<
typename Segment1,
typename Segment2,
typename SegmentIntersectionInfo
>
static inline return_type segments_crosses(side_info const&,
SegmentIntersectionInfo const& sinfo,
Segment1 const& , Segment2 const& )
{
return_type result;
result.assign(sinfo);
return result;
}
template <typename Segment1, typename Segment2, typename Ratio>
static inline return_type segments_collinear(
Segment1 const& , Segment2 const& ,
Ratio const& ra_from_wrt_b, Ratio const& ra_to_wrt_b,
Ratio const& rb_from_wrt_a, Ratio const& rb_to_wrt_a)
{
// We have only one result, for (potentially) two IP's,
// so we take a first one
return_type result;
if (ra_from_wrt_b.on_segment())
{
result.assign(Ratio::zero(), ra_from_wrt_b);
}
else if (rb_from_wrt_a.in_segment())
{
result.assign(rb_from_wrt_a, Ratio::zero());
}
else if (ra_to_wrt_b.on_segment())
{
result.assign(Ratio::one(), ra_to_wrt_b);
}
else if (rb_to_wrt_a.in_segment())
{
result.assign(rb_to_wrt_a, Ratio::one());
}
return result;
}
static inline return_type disjoint()
{
return return_type();
}
static inline return_type error(std::string const&)
{
return return_type();
}
template <typename Segment>
static inline return_type degenerate(Segment const& segment, bool)
{
return return_type();
}
template <typename Segment, typename Ratio>
static inline return_type one_degenerate(Segment const& ,
Ratio const& ratio, bool a_degenerate)
{
return_type result;
if (a_degenerate)
{
// IP lies on ratio w.r.t. segment b
result.assign(Ratio::zero(), ratio);
}
else
{
result.assign(ratio, Ratio::zero());
}
return result;
}
};
}} // namespace policies::relate
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_GEOMETRY_POLICIES_RELATE_INTERSECTION_RATIOS_HPP
|
