ceph/src/boost/boost/geometry/strategies/cartesian/point_in_poly_winding.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4 // Copyright (c) 2013 Adam Wulkiewicz, Lodz, Poland.
   5
   6 // This file was modified by Oracle on 2013-2021.
   7 // Modifications copyright (c) 2013-2021 Oracle and/or its affiliates.
   8 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
   9
  10 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
  11 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
  12
  13 // Use, modification and distribution is subject to the Boost Software License,
  14 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  15 // http://www.boost.org/LICENSE_1_0.txt)
  16
  17 #ifndef BOOST_GEOMETRY_STRATEGY_CARTESIAN_POINT_IN_POLY_WINDING_HPP
  18 #define BOOST_GEOMETRY_STRATEGY_CARTESIAN_POINT_IN_POLY_WINDING_HPP
  19
  20
  21 #include <boost/geometry/core/tags.hpp>
  22
  23 #include <boost/geometry/util/math.hpp>
  24 #include <boost/geometry/util/select_calculation_type.hpp>
  25
  26 #include <boost/geometry/strategy/cartesian/expand_point.hpp>
  27 #include <boost/geometry/strategies/side.hpp>
  28
  29 #include <boost/geometry/strategies/cartesian/point_in_box.hpp>
  30 #include <boost/geometry/strategies/cartesian/disjoint_box_box.hpp>
  31 #include <boost/geometry/strategies/covered_by.hpp>
  32 #include <boost/geometry/strategies/within.hpp>
  33
  34
  35 namespace boost { namespace geometry
  36 {
  37
  38 namespace strategy { namespace within
  39 {
  40
  41
  42 /*!
  43 \brief Within detection using winding rule in cartesian coordinate system.
  44 \ingroup strategies
  45 \tparam Point_ \tparam_point
  46 \tparam PointOfSegment_ \tparam_segment_point
  47 \tparam CalculationType \tparam_calculation
  48 \author Barend Gehrels
  49
  50 \qbk{
  51 [heading See also]
  52 [link geometry.reference.algorithms.within.within_3_with_strategy within (with strategy)]
  53 }
  54  */
  55 template
  56 <
  57     typename Point_ = void, // for backward compatibility
  58     typename PointOfSegment_ = Point_, // for backward compatibility
  59     typename CalculationType = void
  60 >
  61 class cartesian_winding
  62 {
  63     template <typename Point, typename PointOfSegment>
  64     struct calculation_type
  65         : select_calculation_type
  66             <
  67                 Point,
  68                 PointOfSegment,
  69                 CalculationType
  70             >
  71     {};
  72
  73     /*! subclass to keep state */
  74     class counter
  75     {
  76         int m_count;
  77         bool m_touches;
  78
  79         inline int code() const
  80         {
  81             return m_touches ? 0 : m_count == 0 ? -1 : 1;
  82         }
  83
  84     public :
  85         friend class cartesian_winding;
  86
  87         inline counter()
  88             : m_count(0)
  89             , m_touches(false)
  90         {}
  91
  92     };
  93
  94 public:
  95     typedef cartesian_tag cs_tag;
  96
  97     // Typedefs and static methods to fulfill the concept
  98     typedef counter state_type;
  99
 100     template <typename Point, typename PointOfSegment>
 101     static inline bool apply(Point const& point,
 102                              PointOfSegment const& s1, PointOfSegment const& s2,
 103                              counter& state)
 104     {
 105         bool eq1 = false;
 106         bool eq2 = false;
 107
 108         int count = check_segment(point, s1, s2, state, eq1, eq2);
 109         if (count != 0)
 110         {
 111             int side = 0;
 112             if (count == 1 || count == -1)
 113             {
 114                 side = side_equal(point, eq1 ? s1 : s2, count);
 115             }
 116             else // count == 2 || count == -2
 117             {
 118                 // 1 left, -1 right
 119                 using side_strategy_type
 120                     = typename side::services::default_strategy
 121                         <cartesian_tag, CalculationType>::type;
 122                 side = side_strategy_type::apply(s1, s2, point);
 123             }
 124
 125             if (side == 0)
 126             {
 127                 // Point is lying on segment
 128                 state.m_touches = true;
 129                 state.m_count = 0;
 130                 return false;
 131             }
 132
 133             // Side is NEG for right, POS for left.
 134             // The count is -2 for left, 2 for right (or -1/1)
 135             // Side positive thus means RIGHT and LEFTSIDE or LEFT and RIGHTSIDE
 136             // See accompagnying figure (TODO)
 137             if (side * count > 0)
 138             {
 139                 state.m_count += count;
 140             }
 141         }
 142         return ! state.m_touches;
 143     }
 144
 145     static inline int result(counter const& state)
 146     {
 147         return state.code();
 148     }
 149
 150 private:
 151     template <typename Point, typename PointOfSegment>
 152     static inline int check_segment(Point const& point,
 153                                     PointOfSegment const& seg1,
 154                                     PointOfSegment const& seg2,
 155                                     counter& state,
 156                                     bool& eq1, bool& eq2)
 157     {
 158         if (check_touch(point, seg1, seg2, state, eq1, eq2))
 159         {
 160             return 0;
 161         }
 162
 163         return calculate_count(point, seg1, seg2, eq1, eq2);
 164     }
 165
 166     template <typename Point, typename PointOfSegment>
 167     static inline bool check_touch(Point const& point,
 168                                    PointOfSegment const& seg1,
 169                                    PointOfSegment const& seg2,
 170                                    counter& state,
 171                                    bool& eq1, bool& eq2)
 172     {
 173         typedef typename calculation_type<Point, PointOfSegment>::type calc_t;
 174
 175         calc_t const px = get<0>(point);
 176         calc_t const s1x = get<0>(seg1);
 177         calc_t const s2x = get<0>(seg2);
 178
 179         eq1 = math::equals(s1x, px);
 180         eq2 = math::equals(s2x, px);
 181
 182         // Both equal p -> segment vertical
 183         // The only thing which has to be done is check if point is ON segment
 184         if (eq1 && eq2)
 185         {
 186             calc_t const py = get<1>(point);
 187             calc_t const s1y = get<1>(seg1);
 188             calc_t const s2y = get<1>(seg2);
 189             if ((s1y <= py && s2y >= py) || (s2y <= py && s1y >= py))
 190             {
 191                 state.m_touches = true;
 192             }
 193             return true;
 194         }
 195         return false;
 196     }
 197
 198     template <typename Point, typename PointOfSegment>
 199     static inline int calculate_count(Point const& point,
 200                                       PointOfSegment const& seg1,
 201                                       PointOfSegment const& seg2,
 202                                       bool eq1, bool eq2)
 203     {
 204         typedef typename calculation_type<Point, PointOfSegment>::type calc_t;
 205
 206         calc_t const p = get<0>(point);
 207         calc_t const s1 = get<0>(seg1);
 208         calc_t const s2 = get<0>(seg2);
 209
 210         return eq1 ? (s2 > p ?  1 : -1)  // Point on level s1, E/W depending on s2
 211              : eq2 ? (s1 > p ? -1 :  1)  // idem
 212              : s1 < p && s2 > p ?  2     // Point between s1 -> s2 --> E
 213              : s2 < p && s1 > p ? -2     // Point between s2 -> s1 --> W
 214              : 0;
 215     }
 216
 217     template <typename Point, typename PointOfSegment>
 218     static inline int side_equal(Point const& point,
 219                                  PointOfSegment const& se,
 220                                  int count)
 221     {
 222         // NOTE: for D=0 the signs would be reversed
 223         return math::equals(get<1>(point), get<1>(se)) ?
 224                 0 :
 225                 get<1>(point) < get<1>(se) ?
 226                     // assuming count is equal to 1 or -1
 227                     -count : // ( count > 0 ? -1 : 1) :
 228                     count;   // ( count > 0 ? 1 : -1) ;
 229     }
 230 };
 231
 232
 233 #ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
 234
 235 namespace services
 236 {
 237
 238 template <typename PointLike, typename Geometry, typename AnyTag1, typename AnyTag2>
 239 struct default_strategy<PointLike, Geometry, AnyTag1, AnyTag2, pointlike_tag, polygonal_tag, cartesian_tag, cartesian_tag>
 240 {
 241     typedef cartesian_winding<> type;
 242 };
 243
 244 template <typename PointLike, typename Geometry, typename AnyTag1, typename AnyTag2>
 245 struct default_strategy<PointLike, Geometry, AnyTag1, AnyTag2, pointlike_tag, linear_tag, cartesian_tag, cartesian_tag>
 246 {
 247     typedef cartesian_winding<> type;
 248 };
 249
 250 } // namespace services
 251
 252 #endif
 253
 254
 255 }} // namespace strategy::within
 256
 257
 258 #ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
 259 namespace strategy { namespace covered_by { namespace services
 260 {
 261
 262 template <typename PointLike, typename Geometry, typename AnyTag1, typename AnyTag2>
 263 struct default_strategy<PointLike, Geometry, AnyTag1, AnyTag2, pointlike_tag, polygonal_tag, cartesian_tag, cartesian_tag>
 264 {
 265     typedef within::cartesian_winding<> type;
 266 };
 267
 268 template <typename PointLike, typename Geometry, typename AnyTag1, typename AnyTag2>
 269 struct default_strategy<PointLike, Geometry, AnyTag1, AnyTag2, pointlike_tag, linear_tag, cartesian_tag, cartesian_tag>
 270 {
 271     typedef within::cartesian_winding<> type;
 272 };
 273
 274 }}} // namespace strategy::covered_by::services
 275 #endif
 276
 277
 278 }} // namespace boost::geometry
 279
 280
 281 #endif // BOOST_GEOMETRY_STRATEGY_CARTESIAN_POINT_IN_POLY_WINDING_HPP