ceph/src/boost/boost/geometry/views/detail/points_view.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4 // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
   5 // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
   6
   7 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
   8 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
   9
  10 // Use, modification and distribution is subject to the Boost Software License,
  11 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  12 // http://www.boost.org/LICENSE_1_0.txt)
  13
  14 #ifndef BOOST_GEOMETRY_VIEWS_DETAIL_POINTS_VIEW_HPP
  15 #define BOOST_GEOMETRY_VIEWS_DETAIL_POINTS_VIEW_HPP
  16
  17
  18 #include <boost/range.hpp>
  19 #include <boost/iterator/iterator_facade.hpp>
  20 #include <boost/iterator/iterator_categories.hpp>
  21
  22 #include <boost/geometry/core/exception.hpp>
  23
  24 namespace boost { namespace geometry
  25 {
  26
  27 namespace detail
  28 {
  29
  30 // Adapts pointer, on points, to a Boost.Range
  31 template <typename Point, int MaxSize>
  32 class points_view
  33 {
  34     // Iterates over a series of points (indicated by pointer
  35     // to have it lightweight). Probably there is already an
  36     // equivalent of this within Boost. If so, TODO: use that one.
  37     // This used to be "box_iterator" and "segment_iterator".
  38     // ALTERNATIVE: use boost:array and its iterators
  39     struct points_iterator
  40         : public boost::iterator_facade
  41             <
  42                 points_iterator,
  43                 Point const,
  44                 boost::random_access_traversal_tag
  45             >
  46     {
  47         // Constructor: Begin iterator
  48         inline points_iterator(Point const* p)
  49             : m_points(p)
  50             , m_index(0)
  51         {}
  52
  53         // Constructor: End iterator
  54         inline points_iterator(Point const* p, bool)
  55             : m_points(p)
  56             , m_index(MaxSize)
  57         {}
  58
  59         // Constructor: default (for Range Concept checking).
  60         inline points_iterator()
  61             : m_points(NULL)
  62             , m_index(MaxSize)
  63         {}
  64
  65         typedef std::ptrdiff_t difference_type;
  66
  67     private:
  68         friend class boost::iterator_core_access;
  69
  70         inline Point const& dereference() const
  71         {
  72             if (m_index >= 0 && m_index < MaxSize)
  73             {
  74                 return m_points[m_index];
  75             }
  76
  77             // If it index larger (or smaller) return first point
  78             // (assuming initialized)
  79             return m_points[0];
  80         }
  81
  82         inline bool equal(points_iterator const& other) const
  83         {
  84             return other.m_index == this->m_index;
  85         }
  86
  87         inline void increment()
  88         {
  89             m_index++;
  90         }
  91
  92         inline void decrement()
  93         {
  94             m_index--;
  95         }
  96
  97         inline difference_type distance_to(points_iterator const& other) const
  98         {
  99             return other.m_index - this->m_index;
 100         }
 101
 102         inline void advance(difference_type n)
 103         {
 104             m_index += n;
 105         }
 106
 107         Point const* m_points;
 108         difference_type m_index;
 109     };
 110
 111 public :
 112
 113     typedef points_iterator const_iterator;
 114     typedef points_iterator iterator; // must be defined
 115
 116     const_iterator begin() const { return const_iterator(m_points); }
 117     const_iterator end() const { return const_iterator(m_points, true); }
 118
 119     // It may NOT be used non-const, so commented:
 120     //iterator begin() { return m_begin; }
 121     //iterator end() { return m_end; }
 122
 123 protected :
 124
 125     template <typename CopyPolicy>
 126     explicit points_view(CopyPolicy const& copy)
 127     {
 128        copy.apply(m_points);
 129     }
 130
 131 private :
 132     // Copy points here - box might define them otherwise
 133     Point m_points[MaxSize];
 134 };
 135
 136 }
 137
 138 }} // namespace boost::geometry
 139
 140
 141 #endif // BOOST_GEOMETRY_VIEWS_DETAIL_POINTS_VIEW_HPP