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
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
// Boost.Geometry
// Copyright (c) 2022, Oracle and/or its affiliates.
// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
// Licensed under the Boost Software License version 1.0.
// http://www.boost.org/users/license.html
#ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_GC_GROUP_ELEMENTS_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_GC_GROUP_ELEMENTS_HPP
#include <array>
#include <deque>
#include <map>
#include <set>
#include <vector>
#include <boost/range/begin.hpp>
#include <boost/range/size.hpp>
#include <boost/geometry/algorithms/detail/gc_make_rtree.hpp>
#include <boost/geometry/algorithms/detail/visit.hpp>
#include <boost/geometry/algorithms/is_empty.hpp>
#include <boost/geometry/core/topological_dimension.hpp>
#include <boost/geometry/views/detail/random_access_view.hpp>
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DETAIL
namespace detail
{
struct gc_element_id
{
gc_element_id(unsigned int source_id_, std::size_t gc_id_)
: source_id(source_id_), gc_id(gc_id_)
{}
unsigned int source_id;
std::size_t gc_id;
friend bool operator<(gc_element_id const& left, gc_element_id const& right)
{
return left.source_id < right.source_id
|| (left.source_id == right.source_id && left.gc_id < right.gc_id);
}
};
template <typename GC1View, typename GC2View, typename Strategy, typename IntersectingFun, typename DisjointFun>
inline void gc_group_elements(GC1View const& gc1_view, GC2View const& gc2_view, Strategy const& strategy,
IntersectingFun&& intersecting_fun,
DisjointFun&& disjoint_fun,
bool const group_self = false)
{
// NOTE: gc_make_rtree_indexes() already checks for random-access,
// non-recursive geometry collections.
// NOTE: could be replaced with unordered_map and unordered_set
std::map<gc_element_id, std::set<gc_element_id>> adjacent;
// Create adjacency list based on intersecting envelopes of GC elements
auto const rtree2 = gc_make_rtree_indexes(gc2_view, strategy);
if (! group_self) // group only elements from the other GC?
{
for (std::size_t i = 0; i < boost::size(gc1_view); ++i)
{
traits::iter_visit<GC1View>::apply([&](auto const& g1)
{
using g1_t = util::remove_cref_t<decltype(g1)>;
using box1_t = gc_make_rtree_box_t<g1_t>;
box1_t b1 = geometry::return_envelope<box1_t>(g1, strategy);
detail::expand_by_epsilon(b1);
gc_element_id id1 = {0, i};
for (auto qit = rtree2.qbegin(index::intersects(b1)); qit != rtree2.qend(); ++qit)
{
gc_element_id id2 = {1, qit->second};
adjacent[id1].insert(id2);
adjacent[id2].insert(id1);
}
}, boost::begin(gc1_view) + i);
}
}
else // group elements from the same GCs and the other GC
{
auto const rtree1 = gc_make_rtree_indexes(gc1_view, strategy);
for (auto it1 = rtree1.begin() ; it1 != rtree1.end() ; ++it1)
{
auto const b1 = it1->first;
gc_element_id id1 = {0, it1->second};
for (auto qit2 = rtree2.qbegin(index::intersects(b1)); qit2 != rtree2.qend(); ++qit2)
{
gc_element_id id2 = {1, qit2->second};
adjacent[id1].insert(id2);
adjacent[id2].insert(id1);
}
for (auto qit1 = rtree1.qbegin(index::intersects(b1)); qit1 != rtree1.qend(); ++qit1)
{
if (id1.gc_id != qit1->second)
{
gc_element_id id11 = {0, qit1->second};
adjacent[id1].insert(id11);
adjacent[id11].insert(id1);
}
}
}
for (auto it2 = rtree2.begin(); it2 != rtree2.end(); ++it2)
{
auto const b2 = it2->first;
gc_element_id id2 = {1, it2->second};
for (auto qit2 = rtree2.qbegin(index::intersects(b2)); qit2 != rtree2.qend(); ++qit2)
{
if (id2.gc_id != qit2->second)
{
gc_element_id id22 = {1, qit2->second};
adjacent[id2].insert(id22);
adjacent[id22].insert(id2);
}
}
}
}
// Traverse the graph and build connected groups i.e. groups of intersecting envelopes
std::deque<gc_element_id> queue;
std::array<std::vector<bool>, 2> visited = {
std::vector<bool>(boost::size(gc1_view), false),
std::vector<bool>(boost::size(gc2_view), false)
};
for (auto const& elem : adjacent)
{
std::vector<gc_element_id> group;
if (! visited[elem.first.source_id][elem.first.gc_id])
{
queue.push_back(elem.first);
visited[elem.first.source_id][elem.first.gc_id] = true;
group.push_back(elem.first);
while (! queue.empty())
{
gc_element_id e = queue.front();
queue.pop_front();
for (auto const& n : adjacent[e])
{
if (! visited[n.source_id][n.gc_id])
{
queue.push_back(n);
visited[n.source_id][n.gc_id] = true;
group.push_back(n);
}
}
}
}
if (! group.empty())
{
if (! intersecting_fun(group))
{
return;
}
}
}
{
std::vector<gc_element_id> group;
for (std::size_t i = 0; i < visited[0].size(); ++i)
{
if (! visited[0][i])
{
group.emplace_back(0, i);
}
}
for (std::size_t i = 0; i < visited[1].size(); ++i)
{
if (! visited[1][i])
{
group.emplace_back(1, i);
}
}
if (! group.empty())
{
disjoint_fun(group);
}
}
}
} // namespace detail
#endif // DOXYGEN_NO_DETAIL
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_GC_GROUP_ELEMENTS_HPP
|
