compare.hpp 5.7 KB

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  1. // Boost.Geometry (aka GGL, Generic Geometry Library)
  2. // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
  3. // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
  4. // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
  5. // This file was modified by Oracle on 2017-2023.
  6. // Modifications copyright (c) 2017-2023, Oracle and/or its affiliates.
  7. // Contributed and/or modified by Vissarion Fysikopoulos, on behalf of Oracle
  8. // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
  9. // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
  10. // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
  11. // Use, modification and distribution is subject to the Boost Software License,
  12. // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  13. // http://www.boost.org/LICENSE_1_0.txt)
  14. #ifndef BOOST_GEOMETRY_STRATEGIES_COMPARE_HPP
  15. #define BOOST_GEOMETRY_STRATEGIES_COMPARE_HPP
  16. #include <algorithm>
  17. #include <cstddef>
  18. #include <functional>
  19. #include <boost/geometry/core/access.hpp>
  20. #include <boost/geometry/core/cs.hpp>
  21. #include <boost/geometry/core/coordinate_type.hpp>
  22. #include <boost/geometry/core/coordinate_dimension.hpp>
  23. #include <boost/geometry/core/static_assert.hpp>
  24. #include <boost/geometry/util/math.hpp>
  25. namespace boost { namespace geometry
  26. {
  27. namespace strategy { namespace compare
  28. {
  29. struct less
  30. {
  31. template <typename T1, typename T2>
  32. static inline bool apply(T1 const& l, T2 const& r)
  33. {
  34. return l < r;
  35. }
  36. };
  37. struct greater
  38. {
  39. template <typename T1, typename T2>
  40. static inline bool apply(T1 const& l, T2 const& r)
  41. {
  42. return l > r;
  43. }
  44. };
  45. struct equal_to
  46. {
  47. template <typename T1, typename T2>
  48. static inline bool apply(T1 const& , T2 const& )
  49. {
  50. return false;
  51. }
  52. };
  53. struct equals_epsilon
  54. {
  55. template <typename T1, typename T2>
  56. static inline bool apply(T1 const& l, T2 const& r)
  57. {
  58. return math::equals(l, r);
  59. }
  60. };
  61. struct equals_exact
  62. {
  63. template <typename T1, typename T2>
  64. static inline bool apply(T1 const& l, T2 const& r)
  65. {
  66. return l == r;
  67. }
  68. };
  69. #ifndef DOXYGEN_NO_DETAIL
  70. namespace detail
  71. {
  72. template
  73. <
  74. typename ComparePolicy,
  75. typename EqualsPolicy,
  76. std::size_t Dimension,
  77. std::size_t DimensionCount
  78. >
  79. struct compare_loop
  80. {
  81. template <typename Point1, typename Point2>
  82. static inline bool apply(Point1 const& left, Point2 const& right)
  83. {
  84. typename geometry::coordinate_type<Point1>::type const&
  85. cleft = geometry::get<Dimension>(left);
  86. typename geometry::coordinate_type<Point2>::type const&
  87. cright = geometry::get<Dimension>(right);
  88. if (EqualsPolicy::apply(cleft, cright))
  89. {
  90. return compare_loop
  91. <
  92. ComparePolicy,
  93. EqualsPolicy,
  94. Dimension + 1, DimensionCount
  95. >::apply(left, right);
  96. }
  97. else
  98. {
  99. return ComparePolicy::apply(cleft, cright);
  100. }
  101. }
  102. };
  103. template
  104. <
  105. typename ComparePolicy,
  106. typename EqualsPolicy,
  107. std::size_t DimensionCount
  108. >
  109. struct compare_loop<ComparePolicy, EqualsPolicy, DimensionCount, DimensionCount>
  110. {
  111. template <typename Point1, typename Point2>
  112. static inline bool apply(Point1 const& , Point2 const& )
  113. {
  114. // On coming here, points are equal.
  115. // Return false for less/greater.
  116. return false;
  117. }
  118. };
  119. template
  120. <
  121. typename EqualsPolicy,
  122. std::size_t DimensionCount
  123. >
  124. struct compare_loop<strategy::compare::equal_to, EqualsPolicy, DimensionCount, DimensionCount>
  125. {
  126. template <typename Point1, typename Point2>
  127. static inline bool apply(Point1 const& , Point2 const& )
  128. {
  129. // On coming here, points are equal.
  130. // Return true for equal_to.
  131. return true;
  132. }
  133. };
  134. } // namespace detail
  135. #endif // DOXYGEN_NO_DETAIL
  136. template
  137. <
  138. typename ComparePolicy,
  139. typename EqualsPolicy,
  140. int Dimension = -1
  141. >
  142. struct cartesian
  143. {
  144. template <typename Point1, typename Point2>
  145. static inline bool apply(Point1 const& left, Point2 const& right)
  146. {
  147. return compare::detail::compare_loop
  148. <
  149. ComparePolicy, EqualsPolicy, Dimension, Dimension + 1
  150. >::apply(left, right);
  151. }
  152. };
  153. #ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
  154. template
  155. <
  156. typename ComparePolicy,
  157. typename EqualsPolicy
  158. >
  159. struct cartesian<ComparePolicy, EqualsPolicy, -1>
  160. {
  161. template <typename Point1, typename Point2>
  162. static inline bool apply(Point1 const& left, Point2 const& right)
  163. {
  164. return compare::detail::compare_loop
  165. <
  166. ComparePolicy,
  167. EqualsPolicy,
  168. 0,
  169. ((std::min)(geometry::dimension<Point1>::value,
  170. geometry::dimension<Point2>::value))
  171. >::apply(left, right);
  172. }
  173. };
  174. #endif // DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
  175. namespace services
  176. {
  177. template
  178. <
  179. typename ComparePolicy,
  180. typename EqualsPolicy,
  181. typename Point1,
  182. typename Point2 = Point1,
  183. int Dimension = -1,
  184. typename CSTag1 = typename cs_tag<Point1>::type,
  185. typename CSTag2 = typename cs_tag<Point2>::type
  186. >
  187. struct default_strategy
  188. {
  189. BOOST_GEOMETRY_STATIC_ASSERT_FALSE(
  190. "Not implemented for these types.",
  191. CSTag1, CSTag2);
  192. };
  193. template
  194. <
  195. typename ComparePolicy,
  196. typename EqualsPolicy,
  197. typename Point1,
  198. typename Point2,
  199. int Dimension
  200. >
  201. struct default_strategy<ComparePolicy, EqualsPolicy, Point1, Point2, Dimension, cartesian_tag, cartesian_tag>
  202. {
  203. typedef compare::cartesian<ComparePolicy, EqualsPolicy, Dimension> type;
  204. };
  205. } // namespace services
  206. }} // namespace strategy compare
  207. }} // namespace boost::geometry
  208. #endif // BOOST_GEOMETRY_STRATEGIES_COMPARE_HPP