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1 | // Boost.Geometry (aka GGL, Generic Geometry Library) |
2 | ||
3 | // Copyright (c) 2014-2015, Oracle and/or its affiliates. | |
4 | ||
5 | // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle | |
6 | ||
7 | // Licensed under the Boost Software License version 1.0. | |
8 | // http://www.boost.org/users/license.html | |
9 | ||
10 | #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_POLYGON_HPP | |
11 | #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_POLYGON_HPP | |
12 | ||
13 | #include <cstddef> | |
14 | #ifdef BOOST_GEOMETRY_TEST_DEBUG | |
15 | #include <iostream> | |
16 | #endif // BOOST_GEOMETRY_TEST_DEBUG | |
17 | ||
18 | #include <algorithm> | |
19 | #include <deque> | |
20 | #include <iterator> | |
21 | #include <set> | |
22 | #include <vector> | |
23 | ||
24 | #include <boost/core/ignore_unused.hpp> | |
25 | #include <boost/range.hpp> | |
26 | ||
27 | #include <boost/geometry/core/assert.hpp> | |
28 | #include <boost/geometry/core/exterior_ring.hpp> | |
29 | #include <boost/geometry/core/interior_rings.hpp> | |
30 | #include <boost/geometry/core/ring_type.hpp> | |
31 | #include <boost/geometry/core/tags.hpp> | |
32 | ||
33 | #include <boost/geometry/util/condition.hpp> | |
34 | #include <boost/geometry/util/range.hpp> | |
35 | ||
36 | #include <boost/geometry/geometries/box.hpp> | |
37 | ||
38 | #include <boost/geometry/iterators/point_iterator.hpp> | |
39 | ||
40 | #include <boost/geometry/algorithms/covered_by.hpp> | |
41 | #include <boost/geometry/algorithms/disjoint.hpp> | |
42 | #include <boost/geometry/algorithms/expand.hpp> | |
43 | #include <boost/geometry/algorithms/num_interior_rings.hpp> | |
44 | #include <boost/geometry/algorithms/validity_failure_type.hpp> | |
45 | #include <boost/geometry/algorithms/within.hpp> | |
46 | ||
47 | #include <boost/geometry/algorithms/detail/check_iterator_range.hpp> | |
48 | #include <boost/geometry/algorithms/detail/partition.hpp> | |
49 | ||
50 | #include <boost/geometry/algorithms/detail/is_valid/complement_graph.hpp> | |
51 | #include <boost/geometry/algorithms/detail/is_valid/has_valid_self_turns.hpp> | |
52 | #include <boost/geometry/algorithms/detail/is_valid/is_acceptable_turn.hpp> | |
53 | #include <boost/geometry/algorithms/detail/is_valid/ring.hpp> | |
54 | ||
55 | #include <boost/geometry/algorithms/detail/is_valid/debug_print_turns.hpp> | |
56 | #include <boost/geometry/algorithms/detail/is_valid/debug_validity_phase.hpp> | |
57 | #include <boost/geometry/algorithms/detail/is_valid/debug_complement_graph.hpp> | |
58 | ||
59 | #include <boost/geometry/algorithms/dispatch/is_valid.hpp> | |
60 | ||
61 | ||
62 | namespace boost { namespace geometry | |
63 | { | |
64 | ||
65 | ||
66 | #ifndef DOXYGEN_NO_DETAIL | |
67 | namespace detail { namespace is_valid | |
68 | { | |
69 | ||
70 | ||
71 | template <typename Polygon, bool CheckRingValidityOnly = false> | |
72 | class is_valid_polygon | |
73 | { | |
74 | protected: | |
75 | typedef debug_validity_phase<Polygon> debug_phase; | |
76 | ||
77 | template <typename VisitPolicy> | |
78 | struct per_ring | |
79 | { | |
80 | per_ring(VisitPolicy& policy) : m_policy(policy) {} | |
81 | ||
82 | template <typename Ring> | |
83 | inline bool apply(Ring const& ring) const | |
84 | { | |
85 | return detail::is_valid::is_valid_ring | |
86 | < | |
87 | Ring, false, true | |
88 | >::apply(ring, m_policy); | |
89 | } | |
90 | ||
91 | VisitPolicy& m_policy; | |
92 | }; | |
93 | ||
94 | template <typename InteriorRings, typename VisitPolicy> | |
95 | static bool has_valid_interior_rings(InteriorRings const& interior_rings, | |
96 | VisitPolicy& visitor) | |
97 | { | |
98 | return | |
99 | detail::check_iterator_range | |
100 | < | |
101 | per_ring<VisitPolicy>, | |
102 | true // allow for empty interior ring range | |
103 | >::apply(boost::begin(interior_rings), | |
104 | boost::end(interior_rings), | |
105 | per_ring<VisitPolicy>(visitor)); | |
106 | } | |
107 | ||
108 | struct has_valid_rings | |
109 | { | |
110 | template <typename VisitPolicy> | |
111 | static inline bool apply(Polygon const& polygon, VisitPolicy& visitor) | |
112 | { | |
113 | typedef typename ring_type<Polygon>::type ring_type; | |
114 | ||
115 | // check validity of exterior ring | |
116 | debug_phase::apply(1); | |
117 | ||
118 | if (! detail::is_valid::is_valid_ring | |
119 | < | |
120 | ring_type, | |
121 | false // do not check self intersections | |
122 | >::apply(exterior_ring(polygon), visitor)) | |
123 | { | |
124 | return false; | |
125 | } | |
126 | ||
127 | // check validity of interior rings | |
128 | debug_phase::apply(2); | |
129 | ||
130 | return has_valid_interior_rings(geometry::interior_rings(polygon), | |
131 | visitor); | |
132 | } | |
133 | }; | |
134 | ||
135 | ||
136 | // structs for partition -- start | |
137 | struct expand_box | |
138 | { | |
139 | template <typename Box, typename Iterator> | |
140 | static inline void apply(Box& total, Iterator const& it) | |
141 | { | |
142 | geometry::expand(total, geometry::return_envelope<Box>(*it)); | |
143 | } | |
144 | ||
145 | }; | |
146 | ||
147 | struct overlaps_box | |
148 | { | |
149 | template <typename Box, typename Iterator> | |
150 | static inline bool apply(Box const& box, Iterator const& it) | |
151 | { | |
152 | return ! geometry::disjoint(*it, box); | |
153 | } | |
154 | }; | |
155 | ||
156 | ||
157 | struct item_visitor_type | |
158 | { | |
159 | bool items_overlap; | |
160 | ||
161 | item_visitor_type() : items_overlap(false) {} | |
162 | ||
163 | template <typename Item1, typename Item2> | |
164 | inline void apply(Item1 const& item1, Item2 const& item2) | |
165 | { | |
166 | if (! items_overlap | |
167 | && (geometry::within(*points_begin(*item1), *item2) | |
168 | || geometry::within(*points_begin(*item2), *item1)) | |
169 | ) | |
170 | { | |
171 | items_overlap = true; | |
172 | } | |
173 | } | |
174 | }; | |
175 | // structs for partition -- end | |
176 | ||
177 | ||
178 | template | |
179 | < | |
180 | typename RingIterator, | |
181 | typename ExteriorRing, | |
182 | typename TurnIterator, | |
183 | typename VisitPolicy | |
184 | > | |
185 | static inline bool are_holes_inside(RingIterator rings_first, | |
186 | RingIterator rings_beyond, | |
187 | ExteriorRing const& exterior_ring, | |
188 | TurnIterator turns_first, | |
189 | TurnIterator turns_beyond, | |
190 | VisitPolicy& visitor) | |
191 | { | |
192 | boost::ignore_unused(visitor); | |
193 | ||
194 | // collect the interior ring indices that have turns with the | |
195 | // exterior ring | |
196 | std::set<signed_size_type> ring_indices; | |
197 | for (TurnIterator tit = turns_first; tit != turns_beyond; ++tit) | |
198 | { | |
199 | if (tit->operations[0].seg_id.ring_index == -1) | |
200 | { | |
201 | BOOST_GEOMETRY_ASSERT(tit->operations[1].seg_id.ring_index != -1); | |
202 | ring_indices.insert(tit->operations[1].seg_id.ring_index); | |
203 | } | |
204 | else if (tit->operations[1].seg_id.ring_index == -1) | |
205 | { | |
206 | BOOST_GEOMETRY_ASSERT(tit->operations[0].seg_id.ring_index != -1); | |
207 | ring_indices.insert(tit->operations[0].seg_id.ring_index); | |
208 | } | |
209 | } | |
210 | ||
211 | signed_size_type ring_index = 0; | |
212 | for (RingIterator it = rings_first; it != rings_beyond; | |
213 | ++it, ++ring_index) | |
214 | { | |
215 | // do not examine interior rings that have turns with the | |
216 | // exterior ring | |
217 | if (ring_indices.find(ring_index) == ring_indices.end() | |
218 | && ! geometry::covered_by(range::front(*it), exterior_ring)) | |
219 | { | |
220 | return visitor.template apply<failure_interior_rings_outside>(); | |
221 | } | |
222 | } | |
223 | ||
224 | // collect all rings (exterior and/or interior) that have turns | |
225 | for (TurnIterator tit = turns_first; tit != turns_beyond; ++tit) | |
226 | { | |
227 | ring_indices.insert(tit->operations[0].seg_id.ring_index); | |
228 | ring_indices.insert(tit->operations[1].seg_id.ring_index); | |
229 | } | |
230 | ||
231 | // put iterators for interior rings without turns in a vector | |
232 | std::vector<RingIterator> ring_iterators; | |
233 | ring_index = 0; | |
234 | for (RingIterator it = rings_first; it != rings_beyond; | |
235 | ++it, ++ring_index) | |
236 | { | |
237 | if (ring_indices.find(ring_index) == ring_indices.end()) | |
238 | { | |
239 | ring_iterators.push_back(it); | |
240 | } | |
241 | } | |
242 | ||
243 | // call partition to check is interior rings are disjoint from | |
244 | // each other | |
245 | item_visitor_type item_visitor; | |
246 | ||
247 | geometry::partition | |
248 | < | |
249 | geometry::model::box<typename point_type<Polygon>::type>, | |
250 | expand_box, | |
251 | overlaps_box | |
252 | >::apply(ring_iterators, item_visitor); | |
253 | ||
254 | if (item_visitor.items_overlap) | |
255 | { | |
256 | return visitor.template apply<failure_nested_interior_rings>(); | |
257 | } | |
258 | else | |
259 | { | |
260 | return visitor.template apply<no_failure>(); | |
261 | } | |
262 | } | |
263 | ||
264 | template | |
265 | < | |
266 | typename InteriorRings, | |
267 | typename ExteriorRing, | |
268 | typename TurnIterator, | |
269 | typename VisitPolicy | |
270 | > | |
271 | static inline bool are_holes_inside(InteriorRings const& interior_rings, | |
272 | ExteriorRing const& exterior_ring, | |
273 | TurnIterator first, | |
274 | TurnIterator beyond, | |
275 | VisitPolicy& visitor) | |
276 | { | |
277 | return are_holes_inside(boost::begin(interior_rings), | |
278 | boost::end(interior_rings), | |
279 | exterior_ring, | |
280 | first, | |
281 | beyond, | |
282 | visitor); | |
283 | } | |
284 | ||
285 | struct has_holes_inside | |
286 | { | |
287 | template <typename TurnIterator, typename VisitPolicy> | |
288 | static inline bool apply(Polygon const& polygon, | |
289 | TurnIterator first, | |
290 | TurnIterator beyond, | |
291 | VisitPolicy& visitor) | |
292 | { | |
293 | return are_holes_inside(geometry::interior_rings(polygon), | |
294 | geometry::exterior_ring(polygon), | |
295 | first, | |
296 | beyond, | |
297 | visitor); | |
298 | } | |
299 | }; | |
300 | ||
301 | ||
302 | ||
303 | ||
304 | struct has_connected_interior | |
305 | { | |
306 | template <typename TurnIterator, typename VisitPolicy> | |
307 | static inline bool apply(Polygon const& polygon, | |
308 | TurnIterator first, | |
309 | TurnIterator beyond, | |
310 | VisitPolicy& visitor) | |
311 | { | |
312 | boost::ignore_unused(visitor); | |
313 | ||
314 | typedef typename std::iterator_traits | |
315 | < | |
316 | TurnIterator | |
317 | >::value_type turn_type; | |
318 | typedef complement_graph<typename turn_type::point_type> graph; | |
319 | ||
320 | graph g(geometry::num_interior_rings(polygon) + 1); | |
321 | for (TurnIterator tit = first; tit != beyond; ++tit) | |
322 | { | |
323 | typename graph::vertex_handle v1 = g.add_vertex | |
324 | ( tit->operations[0].seg_id.ring_index + 1 ); | |
325 | typename graph::vertex_handle v2 = g.add_vertex | |
326 | ( tit->operations[1].seg_id.ring_index + 1 ); | |
327 | typename graph::vertex_handle vip = g.add_vertex(tit->point); | |
328 | ||
329 | g.add_edge(v1, vip); | |
330 | g.add_edge(v2, vip); | |
331 | } | |
332 | ||
333 | #ifdef BOOST_GEOMETRY_TEST_DEBUG | |
334 | debug_print_complement_graph(std::cout, g); | |
335 | #endif // BOOST_GEOMETRY_TEST_DEBUG | |
336 | ||
337 | if (g.has_cycles()) | |
338 | { | |
339 | return visitor.template apply<failure_disconnected_interior>(); | |
340 | } | |
341 | else | |
342 | { | |
343 | return visitor.template apply<no_failure>(); | |
344 | } | |
345 | } | |
346 | }; | |
347 | ||
348 | public: | |
349 | template <typename VisitPolicy> | |
350 | static inline bool apply(Polygon const& polygon, VisitPolicy& visitor) | |
351 | { | |
352 | if (! has_valid_rings::apply(polygon, visitor)) | |
353 | { | |
354 | return false; | |
355 | } | |
356 | ||
357 | if (BOOST_GEOMETRY_CONDITION(CheckRingValidityOnly)) | |
358 | { | |
359 | return true; | |
360 | } | |
361 | ||
362 | // compute turns and check if all are acceptable | |
363 | debug_phase::apply(3); | |
364 | ||
365 | typedef has_valid_self_turns<Polygon> has_valid_turns; | |
366 | ||
367 | std::deque<typename has_valid_turns::turn_type> turns; | |
368 | bool has_invalid_turns | |
369 | = ! has_valid_turns::apply(polygon, turns, visitor); | |
370 | debug_print_turns(turns.begin(), turns.end()); | |
371 | ||
372 | if (has_invalid_turns) | |
373 | { | |
374 | return false; | |
375 | } | |
376 | ||
377 | // check if all interior rings are inside the exterior ring | |
378 | debug_phase::apply(4); | |
379 | ||
380 | if (! has_holes_inside::apply(polygon, | |
381 | turns.begin(), turns.end(), | |
382 | visitor)) | |
383 | { | |
384 | return false; | |
385 | } | |
386 | ||
387 | // check whether the interior of the polygon is a connected set | |
388 | debug_phase::apply(5); | |
389 | ||
390 | return has_connected_interior::apply(polygon, | |
391 | turns.begin(), | |
392 | turns.end(), | |
393 | visitor); | |
394 | } | |
395 | }; | |
396 | ||
397 | ||
398 | }} // namespace detail::is_valid | |
399 | #endif // DOXYGEN_NO_DETAIL | |
400 | ||
401 | ||
402 | ||
403 | #ifndef DOXYGEN_NO_DISPATCH | |
404 | namespace dispatch | |
405 | { | |
406 | ||
407 | ||
408 | // A Polygon is always a simple geometric object provided that it is valid. | |
409 | // | |
410 | // Reference (for validity of Polygons): OGC 06-103r4 (6.1.11.1) | |
411 | template <typename Polygon, bool AllowEmptyMultiGeometries> | |
412 | struct is_valid | |
413 | < | |
414 | Polygon, polygon_tag, AllowEmptyMultiGeometries | |
415 | > : detail::is_valid::is_valid_polygon<Polygon> | |
416 | {}; | |
417 | ||
418 | ||
419 | } // namespace dispatch | |
420 | #endif // DOXYGEN_NO_DISPATCH | |
421 | ||
422 | ||
423 | }} // namespace boost::geometry | |
424 | ||
425 | #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_POLYGON_HPP |