envelope.hpp 4.5 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. // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
  6. // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
  7. // Use, modification and distribution is subject to the Boost Software License,
  8. // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  9. // http://www.boost.org/LICENSE_1_0.txt)
  10. #ifndef BOOST_GEOMETRY_ALGORITHMS_ENVELOPE_HPP
  11. #define BOOST_GEOMETRY_ALGORITHMS_ENVELOPE_HPP
  12. #include <boost/range.hpp>
  13. #include <boost/numeric/conversion/cast.hpp>
  14. #include <boost/geometry/algorithms/assign.hpp>
  15. #include <boost/geometry/algorithms/expand.hpp>
  16. #include <boost/geometry/algorithms/not_implemented.hpp>
  17. #include <boost/geometry/core/cs.hpp>
  18. #include <boost/geometry/core/exterior_ring.hpp>
  19. #include <boost/geometry/geometries/concepts/check.hpp>
  20. namespace boost { namespace geometry
  21. {
  22. #ifndef DOXYGEN_NO_DETAIL
  23. namespace detail { namespace envelope
  24. {
  25. /// Calculate envelope of an 2D or 3D segment
  26. struct envelope_expand_one
  27. {
  28. template<typename Geometry, typename Box>
  29. static inline void apply(Geometry const& geometry, Box& mbr)
  30. {
  31. assign_inverse(mbr);
  32. geometry::expand(mbr, geometry);
  33. }
  34. };
  35. /// Iterate through range (also used in multi*)
  36. template<typename Range, typename Box>
  37. inline void envelope_range_additional(Range const& range, Box& mbr)
  38. {
  39. typedef typename boost::range_iterator<Range const>::type iterator_type;
  40. for (iterator_type it = boost::begin(range);
  41. it != boost::end(range);
  42. ++it)
  43. {
  44. geometry::expand(mbr, *it);
  45. }
  46. }
  47. /// Generic range dispatching struct
  48. struct envelope_range
  49. {
  50. /// Calculate envelope of range using a strategy
  51. template <typename Range, typename Box>
  52. static inline void apply(Range const& range, Box& mbr)
  53. {
  54. assign_inverse(mbr);
  55. envelope_range_additional(range, mbr);
  56. }
  57. };
  58. }} // namespace detail::envelope
  59. #endif // DOXYGEN_NO_DETAIL
  60. #ifndef DOXYGEN_NO_DISPATCH
  61. namespace dispatch
  62. {
  63. template
  64. <
  65. typename Geometry,
  66. typename Tag = typename tag<Geometry>::type
  67. >
  68. struct envelope: not_implemented<Tag>
  69. {};
  70. template <typename Point>
  71. struct envelope<Point, point_tag>
  72. : detail::envelope::envelope_expand_one
  73. {};
  74. template <typename Box>
  75. struct envelope<Box, box_tag>
  76. : detail::envelope::envelope_expand_one
  77. {};
  78. template <typename Segment>
  79. struct envelope<Segment, segment_tag>
  80. : detail::envelope::envelope_expand_one
  81. {};
  82. template <typename Linestring>
  83. struct envelope<Linestring, linestring_tag>
  84. : detail::envelope::envelope_range
  85. {};
  86. template <typename Ring>
  87. struct envelope<Ring, ring_tag>
  88. : detail::envelope::envelope_range
  89. {};
  90. template <typename Polygon>
  91. struct envelope<Polygon, polygon_tag>
  92. : detail::envelope::envelope_range
  93. {
  94. template <typename Box>
  95. static inline void apply(Polygon const& poly, Box& mbr)
  96. {
  97. // For polygon, inspecting outer ring is sufficient
  98. detail::envelope::envelope_range::apply(exterior_ring(poly), mbr);
  99. }
  100. };
  101. } // namespace dispatch
  102. #endif
  103. /*!
  104. \brief \brief_calc{envelope}
  105. \ingroup envelope
  106. \details \details_calc{envelope,\det_envelope}.
  107. \tparam Geometry \tparam_geometry
  108. \tparam Box \tparam_box
  109. \param geometry \param_geometry
  110. \param mbr \param_box \param_set{envelope}
  111. \qbk{[include reference/algorithms/envelope.qbk]}
  112. \qbk{
  113. [heading Example]
  114. [envelope] [envelope_output]
  115. }
  116. */
  117. template<typename Geometry, typename Box>
  118. inline void envelope(Geometry const& geometry, Box& mbr)
  119. {
  120. concept::check<Geometry const>();
  121. concept::check<Box>();
  122. dispatch::envelope<Geometry>::apply(geometry, mbr);
  123. }
  124. /*!
  125. \brief \brief_calc{envelope}
  126. \ingroup envelope
  127. \details \details_calc{return_envelope,\det_envelope}. \details_return{envelope}
  128. \tparam Box \tparam_box
  129. \tparam Geometry \tparam_geometry
  130. \param geometry \param_geometry
  131. \return \return_calc{envelope}
  132. \qbk{[include reference/algorithms/envelope.qbk]}
  133. \qbk{
  134. [heading Example]
  135. [return_envelope] [return_envelope_output]
  136. }
  137. */
  138. template<typename Box, typename Geometry>
  139. inline Box return_envelope(Geometry const& geometry)
  140. {
  141. concept::check<Geometry const>();
  142. concept::check<Box>();
  143. Box mbr;
  144. dispatch::envelope<Geometry>::apply(geometry, mbr);
  145. return mbr;
  146. }
  147. }} // namespace boost::geometry
  148. #endif // BOOST_GEOMETRY_ALGORITHMS_ENVELOPE_HPP