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1 | // Boost.Geometry (aka GGL, Generic Geometry Library) |
2 | ||
3 | // Copyright (c) 2012-2014 Barend Gehrels, Amsterdam, the Netherlands. | |
4 | ||
92f5a8d4 TL |
5 | // This file was modified by Oracle on 2017, 2018. |
6 | // Modifications copyright (c) 2017-2018, Oracle and/or its affiliates. | |
b32b8144 FG |
7 | |
8 | // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle | |
9 | ||
7c673cae FG |
10 | // Use, modification and distribution is subject to the Boost Software License, |
11 | // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at | |
12 | // http://www.boost.org/LICENSE_1_0.txt) | |
13 | ||
14 | #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_GET_LEFT_TURNS_HPP | |
15 | #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_GET_LEFT_TURNS_HPP | |
16 | ||
92f5a8d4 TL |
17 | #include <set> |
18 | #include <vector> | |
19 | ||
7c673cae FG |
20 | #include <boost/geometry/core/assert.hpp> |
21 | ||
7c673cae FG |
22 | #include <boost/geometry/algorithms/detail/overlay/segment_identifier.hpp> |
23 | #include <boost/geometry/algorithms/detail/overlay/turn_info.hpp> | |
92f5a8d4 | 24 | #include <boost/geometry/arithmetic/arithmetic.hpp> |
7c673cae FG |
25 | #include <boost/geometry/iterators/closing_iterator.hpp> |
26 | #include <boost/geometry/iterators/ever_circling_iterator.hpp> | |
27 | #include <boost/geometry/strategies/side.hpp> | |
28 | ||
29 | namespace boost { namespace geometry | |
30 | { | |
31 | ||
32 | ||
33 | #ifndef DOXYGEN_NO_DETAIL | |
34 | namespace detail | |
35 | { | |
36 | ||
37 | // TODO: move this to /util/ | |
38 | template <typename T> | |
39 | inline std::pair<T, T> ordered_pair(T const& first, T const& second) | |
40 | { | |
41 | return first < second ? std::make_pair(first, second) : std::make_pair(second, first); | |
42 | } | |
43 | ||
44 | namespace left_turns | |
45 | { | |
46 | ||
47 | ||
48 | ||
49 | template <typename Vector> | |
50 | inline int get_quadrant(Vector const& vector) | |
51 | { | |
52 | // Return quadrant as layouted in the code below: | |
53 | // 3 | 0 | |
54 | // ----- | |
55 | // 2 | 1 | |
56 | return geometry::get<1>(vector) >= 0 | |
57 | ? (geometry::get<0>(vector) < 0 ? 3 : 0) | |
58 | : (geometry::get<0>(vector) < 0 ? 2 : 1) | |
59 | ; | |
60 | } | |
61 | ||
62 | template <typename Vector> | |
63 | inline int squared_length(Vector const& vector) | |
64 | { | |
65 | return geometry::get<0>(vector) * geometry::get<0>(vector) | |
66 | + geometry::get<1>(vector) * geometry::get<1>(vector) | |
67 | ; | |
68 | } | |
69 | ||
70 | ||
b32b8144 | 71 | template <typename Point, typename SideStrategy> |
7c673cae FG |
72 | struct angle_less |
73 | { | |
74 | typedef Point vector_type; | |
7c673cae | 75 | |
b32b8144 | 76 | angle_less(Point const& origin, SideStrategy const& strategy) |
7c673cae | 77 | : m_origin(origin) |
b32b8144 | 78 | , m_strategy(strategy) |
7c673cae FG |
79 | {} |
80 | ||
81 | template <typename Angle> | |
82 | inline bool operator()(Angle const& p, Angle const& q) const | |
83 | { | |
84 | // Vector origin -> p and origin -> q | |
85 | vector_type pv = p.point; | |
86 | vector_type qv = q.point; | |
87 | geometry::subtract_point(pv, m_origin); | |
88 | geometry::subtract_point(qv, m_origin); | |
89 | ||
90 | int const quadrant_p = get_quadrant(pv); | |
91 | int const quadrant_q = get_quadrant(qv); | |
92 | if (quadrant_p != quadrant_q) | |
93 | { | |
94 | return quadrant_p < quadrant_q; | |
95 | } | |
96 | // Same quadrant, check if p is located left of q | |
b32b8144 | 97 | int const side = m_strategy.apply(m_origin, q.point, p.point); |
7c673cae FG |
98 | if (side != 0) |
99 | { | |
100 | return side == 1; | |
101 | } | |
102 | // Collinear, check if one is incoming, incoming angles come first | |
103 | if (p.incoming != q.incoming) | |
104 | { | |
105 | return int(p.incoming) < int(q.incoming); | |
106 | } | |
107 | // Same quadrant/side/direction, return longest first | |
108 | // TODO: maybe not necessary, decide this | |
109 | int const length_p = squared_length(pv); | |
110 | int const length_q = squared_length(qv); | |
111 | if (length_p != length_q) | |
112 | { | |
113 | return squared_length(pv) > squared_length(qv); | |
114 | } | |
115 | // They are still the same. Just compare on seg_id | |
116 | return p.seg_id < q.seg_id; | |
117 | } | |
118 | ||
119 | private: | |
120 | Point m_origin; | |
b32b8144 | 121 | SideStrategy m_strategy; |
7c673cae FG |
122 | }; |
123 | ||
b32b8144 | 124 | template <typename Point, typename SideStrategy> |
7c673cae FG |
125 | struct angle_equal_to |
126 | { | |
127 | typedef Point vector_type; | |
b32b8144 FG |
128 | |
129 | inline angle_equal_to(Point const& origin, SideStrategy const& strategy) | |
7c673cae | 130 | : m_origin(origin) |
b32b8144 | 131 | , m_strategy(strategy) |
7c673cae FG |
132 | {} |
133 | ||
134 | template <typename Angle> | |
135 | inline bool operator()(Angle const& p, Angle const& q) const | |
136 | { | |
137 | // Vector origin -> p and origin -> q | |
138 | vector_type pv = p.point; | |
139 | vector_type qv = q.point; | |
140 | geometry::subtract_point(pv, m_origin); | |
141 | geometry::subtract_point(qv, m_origin); | |
142 | ||
143 | if (get_quadrant(pv) != get_quadrant(qv)) | |
144 | { | |
145 | return false; | |
146 | } | |
147 | // Same quadrant, check if p/q are collinear | |
b32b8144 | 148 | int const side = m_strategy.apply(m_origin, q.point, p.point); |
7c673cae FG |
149 | return side == 0; |
150 | } | |
151 | ||
152 | private: | |
153 | Point m_origin; | |
b32b8144 | 154 | SideStrategy m_strategy; |
7c673cae FG |
155 | }; |
156 | ||
157 | template <typename AngleCollection, typename Turns> | |
158 | inline void get_left_turns(AngleCollection const& sorted_angles, | |
159 | Turns& turns) | |
160 | { | |
161 | std::set<std::size_t> good_incoming; | |
162 | std::set<std::size_t> good_outgoing; | |
163 | ||
164 | for (typename boost::range_iterator<AngleCollection const>::type it = | |
165 | sorted_angles.begin(); it != sorted_angles.end(); ++it) | |
166 | { | |
167 | if (!it->blocked) | |
168 | { | |
169 | if (it->incoming) | |
170 | { | |
171 | good_incoming.insert(it->turn_index); | |
172 | } | |
173 | else | |
174 | { | |
175 | good_outgoing.insert(it->turn_index); | |
176 | } | |
177 | } | |
178 | } | |
179 | ||
180 | if (good_incoming.empty() || good_outgoing.empty()) | |
181 | { | |
182 | return; | |
183 | } | |
184 | ||
185 | for (typename boost::range_iterator<AngleCollection const>::type it = | |
186 | sorted_angles.begin(); it != sorted_angles.end(); ++it) | |
187 | { | |
188 | if (good_incoming.count(it->turn_index) == 0 | |
189 | || good_outgoing.count(it->turn_index) == 0) | |
190 | { | |
191 | turns[it->turn_index].remove_on_multi = true; | |
192 | } | |
193 | } | |
194 | } | |
195 | ||
196 | ||
197 | //! Returns the number of clusters | |
b32b8144 FG |
198 | template <typename Point, typename AngleCollection, typename SideStrategy> |
199 | inline std::size_t assign_cluster_indices(AngleCollection& sorted, Point const& origin, | |
200 | SideStrategy const& strategy) | |
7c673cae FG |
201 | { |
202 | // Assign same cluster_index for all turns in same direction | |
203 | BOOST_GEOMETRY_ASSERT(boost::size(sorted) >= 4u); | |
204 | ||
b32b8144 | 205 | angle_equal_to<Point, SideStrategy> comparator(origin, strategy); |
7c673cae FG |
206 | typename boost::range_iterator<AngleCollection>::type it = sorted.begin(); |
207 | ||
208 | std::size_t cluster_index = 0; | |
209 | it->cluster_index = cluster_index; | |
210 | typename boost::range_iterator<AngleCollection>::type previous = it++; | |
211 | for (; it != sorted.end(); ++it) | |
212 | { | |
213 | if (!comparator(*previous, *it)) | |
214 | { | |
215 | cluster_index++; | |
216 | previous = it; | |
217 | } | |
218 | it->cluster_index = cluster_index; | |
219 | } | |
220 | return cluster_index + 1; | |
221 | } | |
222 | ||
223 | template <typename AngleCollection> | |
224 | inline void block_turns(AngleCollection& sorted, std::size_t cluster_size) | |
225 | { | |
226 | BOOST_GEOMETRY_ASSERT(boost::size(sorted) >= 4u && cluster_size > 0); | |
227 | ||
228 | std::vector<std::pair<bool, bool> > directions; | |
229 | for (std::size_t i = 0; i < cluster_size; i++) | |
230 | { | |
231 | directions.push_back(std::make_pair(false, false)); | |
232 | } | |
233 | ||
234 | for (typename boost::range_iterator<AngleCollection const>::type it = sorted.begin(); | |
235 | it != sorted.end(); ++it) | |
236 | { | |
237 | if (it->incoming) | |
238 | { | |
239 | directions[it->cluster_index].first = true; | |
240 | } | |
241 | else | |
242 | { | |
243 | directions[it->cluster_index].second = true; | |
244 | } | |
245 | } | |
246 | ||
247 | for (typename boost::range_iterator<AngleCollection>::type it = sorted.begin(); | |
248 | it != sorted.end(); ++it) | |
249 | { | |
92f5a8d4 TL |
250 | std::size_t const cluster_index = it->cluster_index; |
251 | std::size_t const previous_index | |
252 | = cluster_index == 0 ? cluster_size - 1 : cluster_index - 1; | |
253 | std::size_t const next_index | |
254 | = cluster_index + 1 >= cluster_size ? 0 : cluster_index + 1; | |
7c673cae FG |
255 | |
256 | if (directions[cluster_index].first | |
257 | && directions[cluster_index].second) | |
258 | { | |
259 | it->blocked = true; | |
260 | } | |
261 | else if (!directions[cluster_index].first | |
262 | && directions[cluster_index].second | |
263 | && directions[previous_index].second) | |
264 | { | |
265 | // Only outgoing, previous was also outgoing: block this one | |
266 | it->blocked = true; | |
267 | } | |
268 | else if (directions[cluster_index].first | |
269 | && !directions[cluster_index].second | |
270 | && !directions[previous_index].first | |
271 | && directions[previous_index].second) | |
272 | { | |
273 | // Only incoming, previous was only outgoing: block this one | |
274 | it->blocked = true; | |
275 | } | |
276 | else if (directions[cluster_index].first | |
277 | && !directions[cluster_index].second | |
278 | && directions[next_index].first | |
279 | && !directions[next_index].second) | |
280 | { | |
281 | // Only incoming, next also incoming, block this one | |
282 | it->blocked = true; | |
283 | } | |
284 | } | |
285 | } | |
286 | ||
287 | #if defined(BOOST_GEOMETRY_BUFFER_ENLARGED_CLUSTERS) | |
288 | template <typename AngleCollection, typename Point> | |
289 | inline bool has_rounding_issues(AngleCollection const& angles, Point const& origin) | |
290 | { | |
291 | for (typename boost::range_iterator<AngleCollection const>::type it = | |
292 | angles.begin(); it != angles.end(); ++it) | |
293 | { | |
294 | // Vector origin -> p and origin -> q | |
295 | typedef Point vector_type; | |
296 | vector_type v = it->point; | |
297 | geometry::subtract_point(v, origin); | |
298 | return geometry::math::abs(geometry::get<0>(v)) <= 1 | |
299 | || geometry::math::abs(geometry::get<1>(v)) <= 1 | |
300 | ; | |
301 | } | |
302 | return false; | |
303 | } | |
304 | #endif | |
305 | ||
306 | ||
307 | } // namespace left_turns | |
308 | ||
309 | } // namespace detail | |
310 | #endif // DOXYGEN_NO_DETAIL | |
311 | ||
312 | ||
313 | }} // namespace boost::geometry | |
314 | ||
315 | #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_GET_LEFT_TURNS_HPP |