boost/geometry/algorithms/detail/is_simple/linear.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2014-2019, Oracle and/or its affiliates.
   4
   5 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
   6 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
   7
   8 // Licensed under the Boost Software License version 1.0.
   9 // http://www.boost.org/users/license.html
  10
  11 #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_SIMPLE_LINEAR_HPP
  12 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_SIMPLE_LINEAR_HPP
  13
  14 #include <algorithm>
  15 #include <deque>
  16
  17 #include <boost/range.hpp>
  18
  19 #include <boost/geometry/core/assert.hpp>
  20 #include <boost/geometry/core/closure.hpp>
  21 #include <boost/geometry/core/coordinate_type.hpp>
  22 #include <boost/geometry/core/point_type.hpp>
  23 #include <boost/geometry/core/tag.hpp>
  24 #include <boost/geometry/core/tags.hpp>
  25
  26 #include <boost/geometry/util/range.hpp>
  27
  28 #include <boost/geometry/policies/predicate_based_interrupt_policy.hpp>
  29 #include <boost/geometry/policies/robustness/no_rescale_policy.hpp>
  30 #include <boost/geometry/policies/robustness/segment_ratio.hpp>
  31
  32 #include <boost/geometry/algorithms/intersects.hpp>
  33 #include <boost/geometry/algorithms/not_implemented.hpp>
  34
  35 #include <boost/geometry/algorithms/detail/check_iterator_range.hpp>
  36 #include <boost/geometry/algorithms/detail/signed_size_type.hpp>
  37
  38 #include <boost/geometry/algorithms/detail/disjoint/linear_linear.hpp>
  39 #include <boost/geometry/algorithms/detail/equals/point_point.hpp>
  40 #include <boost/geometry/algorithms/detail/overlay/get_turn_info.hpp>
  41 #include <boost/geometry/algorithms/detail/overlay/turn_info.hpp>
  42 #include <boost/geometry/algorithms/detail/overlay/self_turn_points.hpp>
  43 #include <boost/geometry/algorithms/detail/is_valid/has_duplicates.hpp>
  44 #include <boost/geometry/algorithms/detail/is_valid/has_spikes.hpp>
  45
  46 #include <boost/geometry/algorithms/detail/is_simple/debug_print_boundary_points.hpp>
  47 #include <boost/geometry/algorithms/detail/is_simple/failure_policy.hpp>
  48 #include <boost/geometry/algorithms/detail/is_valid/debug_print_turns.hpp>
  49
  50 #include <boost/geometry/algorithms/dispatch/is_simple.hpp>
  51
  52 #include <boost/geometry/strategies/intersection.hpp>
  53
  54
  55 namespace boost { namespace geometry
  56 {
  57
  58
  59 #ifndef DOXYGEN_NO_DETAIL
  60 namespace detail { namespace is_simple
  61 {
  62
  63
  64 template <typename Turn>
  65 inline bool check_segment_indices(Turn const& turn,
  66                                   signed_size_type last_index)
  67 {
  68     return
  69         (turn.operations[0].seg_id.segment_index == 0
  70          && turn.operations[1].seg_id.segment_index == last_index)
  71         ||
  72         (turn.operations[0].seg_id.segment_index == 0
  73          && turn.operations[1].seg_id.segment_index == last_index);
  74 }
  75
  76
  77 template
  78 <
  79     typename Geometry,
  80     typename EqPPStrategy,
  81     typename Tag = typename tag<Geometry>::type
  82 >
  83 class is_acceptable_turn
  84     : not_implemented<Geometry>
  85 {};
  86
  87 template <typename Linestring, typename EqPPStrategy>
  88 class is_acceptable_turn<Linestring, EqPPStrategy, linestring_tag>
  89 {
  90 public:
  91     is_acceptable_turn(Linestring const& linestring)
  92         : m_linestring(linestring)
  93         , m_is_closed(geometry::detail::equals::equals_point_point(range::front(linestring),
  94                                                                    range::back(linestring),
  95                                                                    EqPPStrategy()))
  96     {}
  97
  98     template <typename Turn>
  99     inline bool apply(Turn const& turn) const
 100     {
 101         BOOST_GEOMETRY_ASSERT(boost::size(m_linestring) > 1);
 102         return m_is_closed
 103             && turn.method == overlay::method_none
 104             && check_segment_indices(turn, boost::size(m_linestring) - 2)
 105             && turn.operations[0].fraction.is_zero();
 106     }
 107
 108 private:
 109     Linestring const& m_linestring;
 110     bool const m_is_closed;
 111 };
 112
 113 template <typename MultiLinestring, typename EqPPStrategy>
 114 class is_acceptable_turn<MultiLinestring, EqPPStrategy, multi_linestring_tag>
 115 {
 116 private:
 117     template <typename Point1, typename Point2>
 118     static inline bool equals_point_point(Point1 const& point1, Point2 const& point2)
 119     {
 120         return geometry::detail::equals::equals_point_point(point1, point2,
 121                                                             EqPPStrategy());
 122     }
 123
 124     template <typename Point, typename Linestring>
 125     static inline bool is_boundary_point_of(Point const& point,
 126                                             Linestring const& linestring)
 127     {
 128         BOOST_GEOMETRY_ASSERT(boost::size(linestring) > 1);
 129         return
 130             !equals_point_point(range::front(linestring), range::back(linestring))
 131             &&
 132             (equals_point_point(point, range::front(linestring))
 133              || equals_point_point(point, range::back(linestring)));
 134     }
 135
 136     template <typename Turn, typename Linestring>
 137     static inline bool is_closing_point_of(Turn const& turn,
 138                                            Linestring const& linestring)
 139     {
 140         BOOST_GEOMETRY_ASSERT(boost::size(linestring) > 1);
 141         return
 142             turn.method == overlay::method_none
 143             &&
 144             check_segment_indices(turn, boost::size(linestring) - 2)
 145             &&
 146             equals_point_point(range::front(linestring), range::back(linestring))
 147             &&
 148             turn.operations[0].fraction.is_zero();
 149             ;
 150     }
 151
 152     template <typename Linestring1, typename Linestring2>
 153     static inline bool have_same_boundary_points(Linestring1 const& ls1,
 154                                                  Linestring2 const& ls2)
 155     {
 156         return
 157             equals_point_point(range::front(ls1), range::front(ls2))
 158             ?
 159             equals_point_point(range::back(ls1), range::back(ls2))
 160             :
 161             (equals_point_point(range::front(ls1), range::back(ls2))
 162              &&
 163                 equals_point_point(range::back(ls1), range::front(ls2)))
 164             ;
 165     }
 166
 167 public:
 168     is_acceptable_turn(MultiLinestring const& multilinestring)
 169         : m_multilinestring(multilinestring)
 170     {}
 171
 172     template <typename Turn>
 173     inline bool apply(Turn const& turn) const
 174     {
 175         typedef typename boost::range_value<MultiLinestring>::type linestring_type;
 176
 177         linestring_type const& ls1 =
 178             range::at(m_multilinestring, turn.operations[0].seg_id.multi_index);
 179
 180         linestring_type const& ls2 =
 181             range::at(m_multilinestring, turn.operations[1].seg_id.multi_index);
 182
 183         if (turn.operations[0].seg_id.multi_index
 184             == turn.operations[1].seg_id.multi_index)
 185         {
 186             return is_closing_point_of(turn, ls1);
 187         }
 188
 189         return
 190             is_boundary_point_of(turn.point, ls1)
 191             && is_boundary_point_of(turn.point, ls2)
 192             &&
 193             ( boost::size(ls1) != 2
 194               || boost::size(ls2) != 2
 195               || ! have_same_boundary_points(ls1, ls2) );
 196     }
 197
 198 private:
 199     MultiLinestring const& m_multilinestring;
 200 };
 201
 202
 203 template <typename Linear, typename Strategy>
 204 inline bool has_self_intersections(Linear const& linear, Strategy const& strategy)
 205 {
 206     typedef typename point_type<Linear>::type point_type;
 207
 208     // compute self turns
 209     typedef detail::overlay::turn_info<point_type> turn_info;
 210
 211     std::deque<turn_info> turns;
 212
 213     typedef detail::overlay::get_turn_info
 214         <
 215             detail::disjoint::assign_disjoint_policy
 216         > turn_policy;
 217
 218     typedef is_acceptable_turn
 219         <
 220             Linear,
 221             typename Strategy::equals_point_point_strategy_type
 222         > is_acceptable_turn_type;
 223
 224     is_acceptable_turn_type predicate(linear);
 225     detail::overlay::predicate_based_interrupt_policy
 226         <
 227             is_acceptable_turn_type
 228         > interrupt_policy(predicate);
 229
 230     // TODO: skip_adjacent should be set to false
 231     detail::self_get_turn_points::get_turns
 232         <
 233             false, turn_policy
 234         >::apply(linear,
 235                  strategy,
 236                  detail::no_rescale_policy(),
 237                  turns,
 238                  interrupt_policy, 0, true);
 239
 240     detail::is_valid::debug_print_turns(turns.begin(), turns.end());
 241     debug_print_boundary_points(linear);
 242
 243     return interrupt_policy.has_intersections;
 244 }
 245
 246
 247 template <typename Linestring, bool CheckSelfIntersections = true>
 248 struct is_simple_linestring
 249 {
 250     template <typename Strategy>
 251     static inline bool apply(Linestring const& linestring,
 252                              Strategy const& strategy)
 253     {
 254         simplicity_failure_policy policy;
 255         return ! boost::empty(linestring)
 256             && ! detail::is_valid::has_duplicates
 257                     <
 258                         Linestring, closed, typename Strategy::cs_tag
 259                     >::apply(linestring, policy)
 260             && ! detail::is_valid::has_spikes
 261                     <
 262                         Linestring, closed
 263                     >::apply(linestring, policy, strategy.get_side_strategy());
 264     }
 265 };
 266
 267 template <typename Linestring>
 268 struct is_simple_linestring<Linestring, true>
 269 {
 270     template <typename Strategy>
 271     static inline bool apply(Linestring const& linestring,
 272                              Strategy const& strategy)
 273     {
 274         return is_simple_linestring
 275                 <
 276                     Linestring, false
 277                 >::apply(linestring, strategy)
 278             && ! has_self_intersections(linestring, strategy);
 279     }
 280 };
 281
 282
 283 template <typename MultiLinestring>
 284 struct is_simple_multilinestring
 285 {
 286 private:
 287     template <typename Strategy>
 288     struct per_linestring
 289     {
 290         per_linestring(Strategy const& strategy)
 291             : m_strategy(strategy)
 292         {}
 293
 294         template <typename Linestring>
 295         inline bool apply(Linestring const& linestring) const
 296         {
 297             return detail::is_simple::is_simple_linestring
 298                 <
 299                     Linestring,
 300                     false // do not compute self-intersections
 301                 >::apply(linestring, m_strategy);
 302         }
 303
 304         Strategy const& m_strategy;
 305     };
 306
 307 public:
 308     template <typename Strategy>
 309     static inline bool apply(MultiLinestring const& multilinestring,
 310                              Strategy const& strategy)
 311     {
 312         typedef per_linestring<Strategy> per_ls;
 313
 314         // check each of the linestrings for simplicity
 315         // but do not compute self-intersections yet; these will be
 316         // computed for the entire multilinestring
 317         if ( ! detail::check_iterator_range
 318                  <
 319                      per_ls, // do not compute self-intersections
 320                      true // allow empty multilinestring
 321                  >::apply(boost::begin(multilinestring),
 322                           boost::end(multilinestring),
 323                           per_ls(strategy))
 324              )
 325         {
 326             return false;
 327         }
 328
 329         return ! has_self_intersections(multilinestring, strategy);
 330     }
 331 };
 332
 333
 334
 335 }} // namespace detail::is_simple
 336 #endif // DOXYGEN_NO_DETAIL
 337
 338
 339
 340 #ifndef DOXYGEN_NO_DISPATCH
 341 namespace dispatch
 342 {
 343
 344 // A linestring is a curve.
 345 // A curve is simple if it does not pass through the same point twice,
 346 // with the possible exception of its two endpoints
 347 //
 348 // Reference: OGC 06-103r4 (6.1.6.1)
 349 template <typename Linestring>
 350 struct is_simple<Linestring, linestring_tag>
 351     : detail::is_simple::is_simple_linestring<Linestring>
 352 {};
 353
 354
 355 // A MultiLinestring is a MultiCurve
 356 // A MultiCurve is simple if all of its elements are simple and the
 357 // only intersections between any two elements occur at Points that
 358 // are on the boundaries of both elements.
 359 //
 360 // Reference: OGC 06-103r4 (6.1.8.1; Fig. 9)
 361 template <typename MultiLinestring>
 362 struct is_simple<MultiLinestring, multi_linestring_tag>
 363     : detail::is_simple::is_simple_multilinestring<MultiLinestring>
 364 {};
 365
 366
 367 } // namespace dispatch
 368 #endif // DOXYGEN_NO_DISPATCH
 369
 370
 371 }} // namespace boost::geometry
 372
 373
 374 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_SIMPLE_LINEAR_HPP