summaryrefslogtreecommitdiff
path: root/boost/geometry/algorithms/detail/is_valid/polygon.hpp
blob: f7e22fb8d2952064ac959ff7e807d33e84549c26 (plain)
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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
// Boost.Geometry (aka GGL, Generic Geometry Library)

// Copyright (c) 2014-2017, Oracle and/or its affiliates.

// Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
// 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_IS_VALID_POLYGON_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_POLYGON_HPP

#include <cstddef>
#ifdef BOOST_GEOMETRY_TEST_DEBUG
#include <iostream>
#endif // BOOST_GEOMETRY_TEST_DEBUG

#include <algorithm>
#include <deque>
#include <iterator>
#include <set>
#include <vector>

#include <boost/core/ignore_unused.hpp>
#include <boost/range.hpp>

#include <boost/geometry/core/assert.hpp>
#include <boost/geometry/core/exterior_ring.hpp>
#include <boost/geometry/core/interior_rings.hpp>
#include <boost/geometry/core/ring_type.hpp>
#include <boost/geometry/core/tags.hpp>

#include <boost/geometry/util/condition.hpp>
#include <boost/geometry/util/range.hpp>

#include <boost/geometry/geometries/box.hpp>

#include <boost/geometry/iterators/point_iterator.hpp>

#include <boost/geometry/algorithms/covered_by.hpp>
#include <boost/geometry/algorithms/disjoint.hpp>
#include <boost/geometry/algorithms/expand.hpp>
#include <boost/geometry/algorithms/num_interior_rings.hpp>
#include <boost/geometry/algorithms/validity_failure_type.hpp>
#include <boost/geometry/algorithms/within.hpp>

#include <boost/geometry/algorithms/detail/check_iterator_range.hpp>
#include <boost/geometry/algorithms/detail/partition.hpp>

#include <boost/geometry/algorithms/detail/is_valid/complement_graph.hpp>
#include <boost/geometry/algorithms/detail/is_valid/has_valid_self_turns.hpp>
#include <boost/geometry/algorithms/detail/is_valid/is_acceptable_turn.hpp>
#include <boost/geometry/algorithms/detail/is_valid/ring.hpp>

#include <boost/geometry/algorithms/detail/is_valid/debug_print_turns.hpp>
#include <boost/geometry/algorithms/detail/is_valid/debug_validity_phase.hpp>
#include <boost/geometry/algorithms/detail/is_valid/debug_complement_graph.hpp>

#include <boost/geometry/algorithms/dispatch/is_valid.hpp>


namespace boost { namespace geometry
{


#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace is_valid
{


template <typename Polygon, bool CheckRingValidityOnly = false>
class is_valid_polygon
{
protected:
    typedef debug_validity_phase<Polygon> debug_phase;

    template <typename VisitPolicy, typename Strategy>
    struct per_ring
    {
        per_ring(VisitPolicy& policy, Strategy const& strategy)
            : m_policy(policy)
            , m_strategy(strategy)
        {}

        template <typename Ring>
        inline bool apply(Ring const& ring) const
        {
            return detail::is_valid::is_valid_ring
                <
                    Ring, false, true
                >::apply(ring, m_policy, m_strategy);
        }

        VisitPolicy& m_policy;
        Strategy const& m_strategy;
    };

    template <typename InteriorRings, typename VisitPolicy, typename Strategy>
    static bool has_valid_interior_rings(InteriorRings const& interior_rings,
                                         VisitPolicy& visitor,
                                         Strategy const& strategy)
    {
        return
            detail::check_iterator_range
                <
                    per_ring<VisitPolicy, Strategy>,
                    true // allow for empty interior ring range
                >::apply(boost::begin(interior_rings),
                         boost::end(interior_rings),
                         per_ring<VisitPolicy, Strategy>(visitor, strategy));
    }

    struct has_valid_rings
    {
        template <typename VisitPolicy, typename Strategy>
        static inline bool apply(Polygon const& polygon,
                                 VisitPolicy& visitor,
                                 Strategy const& strategy)
        {
            typedef typename ring_type<Polygon>::type ring_type;

            // check validity of exterior ring
            debug_phase::apply(1);

            if (! detail::is_valid::is_valid_ring
                     <
                         ring_type,
                         false // do not check self intersections
                     >::apply(exterior_ring(polygon), visitor, strategy))
            {
                return false;
            }

            // check validity of interior rings
            debug_phase::apply(2);

            return has_valid_interior_rings(geometry::interior_rings(polygon),
                                            visitor,
                                            strategy);
        }
    };


    // structs for partition -- start
    struct expand_box
    {
        template <typename Box, typename Iterator>
        static inline void apply(Box& total, Iterator const& it)
        {
            geometry::expand(total, geometry::return_envelope<Box>(*it));
        }

    };

    struct overlaps_box
    {
        template <typename Box, typename Iterator>
        static inline bool apply(Box const& box, Iterator const& it)
        {
            return ! geometry::disjoint(*it, box);
        }
    };


    struct item_visitor_type
    {
        bool items_overlap;

        item_visitor_type() : items_overlap(false) {}

        template <typename Item1, typename Item2>
        inline void apply(Item1 const& item1, Item2 const& item2)
        {
            if (! items_overlap
                && (geometry::within(*points_begin(*item1), *item2)
                    || geometry::within(*points_begin(*item2), *item1))
                )
            {
                items_overlap = true;
            }
        }
    };
    // structs for partition -- end


    template
    <
        typename RingIterator,
        typename ExteriorRing,
        typename TurnIterator,
        typename VisitPolicy
    >
    static inline bool are_holes_inside(RingIterator rings_first,
                                        RingIterator rings_beyond,
                                        ExteriorRing const& exterior_ring,
                                        TurnIterator turns_first,
                                        TurnIterator turns_beyond,
                                        VisitPolicy& visitor)
    {
        boost::ignore_unused(visitor);

        // collect the interior ring indices that have turns with the
        // exterior ring
        std::set<signed_size_type> ring_indices;
        for (TurnIterator tit = turns_first; tit != turns_beyond; ++tit)
        {
            if (tit->operations[0].seg_id.ring_index == -1)
            {
                BOOST_GEOMETRY_ASSERT(tit->operations[1].seg_id.ring_index != -1);
                ring_indices.insert(tit->operations[1].seg_id.ring_index);
            }
            else if (tit->operations[1].seg_id.ring_index == -1)
            {
                BOOST_GEOMETRY_ASSERT(tit->operations[0].seg_id.ring_index != -1);
                ring_indices.insert(tit->operations[0].seg_id.ring_index);
            }
        }

        signed_size_type ring_index = 0;
        for (RingIterator it = rings_first; it != rings_beyond;
             ++it, ++ring_index)
        {
            // do not examine interior rings that have turns with the
            // exterior ring
            if (ring_indices.find(ring_index) == ring_indices.end()
                && ! geometry::covered_by(range::front(*it), exterior_ring))
            {
                return visitor.template apply<failure_interior_rings_outside>();
            }
        }

        // collect all rings (exterior and/or interior) that have turns
        for (TurnIterator tit = turns_first; tit != turns_beyond; ++tit)
        {
            ring_indices.insert(tit->operations[0].seg_id.ring_index);
            ring_indices.insert(tit->operations[1].seg_id.ring_index);
        }

        // put iterators for interior rings without turns in a vector
        std::vector<RingIterator> ring_iterators;
        ring_index = 0;
        for (RingIterator it = rings_first; it != rings_beyond;
             ++it, ++ring_index)
        {
            if (ring_indices.find(ring_index) == ring_indices.end())
            {
                ring_iterators.push_back(it);
            }
        }

        // call partition to check is interior rings are disjoint from
        // each other
        item_visitor_type item_visitor;

        geometry::partition
            <
                geometry::model::box<typename point_type<Polygon>::type>
            >::apply(ring_iterators, item_visitor, expand_box(), overlaps_box());

        if (item_visitor.items_overlap)
        {
            return visitor.template apply<failure_nested_interior_rings>();
        }
        else
        {
            return visitor.template apply<no_failure>();
        }
    }

    template
    <
        typename InteriorRings,
        typename ExteriorRing,
        typename TurnIterator,
        typename VisitPolicy
    >
    static inline bool are_holes_inside(InteriorRings const& interior_rings,
                                        ExteriorRing const& exterior_ring,
                                        TurnIterator first,
                                        TurnIterator beyond,
                                        VisitPolicy& visitor)
    {
        return are_holes_inside(boost::begin(interior_rings),
                                boost::end(interior_rings),
                                exterior_ring,
                                first,
                                beyond,
                                visitor);
    }

    struct has_holes_inside
    {    
        template <typename TurnIterator, typename VisitPolicy>
        static inline bool apply(Polygon const& polygon,
                                 TurnIterator first,
                                 TurnIterator beyond,
                                 VisitPolicy& visitor)
        {
            return are_holes_inside(geometry::interior_rings(polygon),
                                    geometry::exterior_ring(polygon),
                                    first,
                                    beyond,
                                    visitor);
        }
    };




    struct has_connected_interior
    {
        template <typename TurnIterator, typename VisitPolicy>
        static inline bool apply(Polygon const& polygon,
                                 TurnIterator first,
                                 TurnIterator beyond,
                                 VisitPolicy& visitor)
        {
            boost::ignore_unused(visitor);

            typedef typename std::iterator_traits
                <
                    TurnIterator
                >::value_type turn_type;
            typedef complement_graph<typename turn_type::point_type> graph;

            graph g(geometry::num_interior_rings(polygon) + 1);
            for (TurnIterator tit = first; tit != beyond; ++tit)
            {
                typename graph::vertex_handle v1 = g.add_vertex
                    ( tit->operations[0].seg_id.ring_index + 1 );
                typename graph::vertex_handle v2 = g.add_vertex
                    ( tit->operations[1].seg_id.ring_index + 1 );
                typename graph::vertex_handle vip = g.add_vertex(tit->point);

                g.add_edge(v1, vip);
                g.add_edge(v2, vip);
            }

#ifdef BOOST_GEOMETRY_TEST_DEBUG
            debug_print_complement_graph(std::cout, g);
#endif // BOOST_GEOMETRY_TEST_DEBUG

            if (g.has_cycles())
            {
                return visitor.template apply<failure_disconnected_interior>();
            }
            else
            {
                return visitor.template apply<no_failure>();
            }
        }
    };

public:
    template <typename VisitPolicy, typename Strategy>
    static inline bool apply(Polygon const& polygon,
                             VisitPolicy& visitor,
                             Strategy const& strategy)
    {
        if (! has_valid_rings::apply(polygon, visitor, strategy))
        {
            return false;
        }

        if (BOOST_GEOMETRY_CONDITION(CheckRingValidityOnly))
        {
            return true;
        }

        // compute turns and check if all are acceptable
        debug_phase::apply(3);

        typedef has_valid_self_turns<Polygon> has_valid_turns;

        std::deque<typename has_valid_turns::turn_type> turns;
        bool has_invalid_turns
            = ! has_valid_turns::apply(polygon, turns, visitor, strategy);
        debug_print_turns(turns.begin(), turns.end());

        if (has_invalid_turns)
        {
            return false;
        }

        // check if all interior rings are inside the exterior ring
        debug_phase::apply(4);

        if (! has_holes_inside::apply(polygon,
                                      turns.begin(), turns.end(),
                                      visitor))
        {
            return false;
        }

        // check whether the interior of the polygon is a connected set
        debug_phase::apply(5);

        return has_connected_interior::apply(polygon,
                                             turns.begin(),
                                             turns.end(),
                                             visitor);
    }
};


}} // namespace detail::is_valid
#endif // DOXYGEN_NO_DETAIL



#ifndef DOXYGEN_NO_DISPATCH
namespace dispatch
{


// A Polygon is always a simple geometric object provided that it is valid.
//
// Reference (for validity of Polygons): OGC 06-103r4 (6.1.11.1)
template <typename Polygon, bool AllowEmptyMultiGeometries>
struct is_valid
    <
        Polygon, polygon_tag, AllowEmptyMultiGeometries
    > : detail::is_valid::is_valid_polygon<Polygon>
{};


} // namespace dispatch
#endif // DOXYGEN_NO_DISPATCH


}} // namespace boost::geometry

#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_POLYGON_HPP