ceph/src/boost/boost/geometry/algorithms/detail/centroid/translating_transformer.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 // Copyright (c) 2014 Adam Wulkiewicz, Lodz, Poland.
   7
   8 // This file was modified by Oracle on 2014.
   9 // Modifications copyright (c) 2014 Oracle and/or its affiliates.
  10
  11 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
  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_ALGORITHMS_DETAIL_CENTROID_TRANSLATING_TRANSFORMER_HPP
  18 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_CENTROID_TRANSLATING_TRANSFORMER_HPP
  19
  20
  21 #include <cstddef>
  22
  23 #include <boost/core/addressof.hpp>
  24 #include <boost/core/ref.hpp>
  25
  26 #include <boost/geometry/core/cs.hpp>
  27 #include <boost/geometry/core/tag_cast.hpp>
  28 #include <boost/geometry/core/tags.hpp>
  29 #include <boost/geometry/core/point_type.hpp>
  30
  31 #include <boost/geometry/arithmetic/arithmetic.hpp>
  32
  33 #include <boost/geometry/iterators/point_iterator.hpp>
  34
  35
  36 namespace boost { namespace geometry
  37 {
  38
  39 #ifndef DOXYGEN_NO_DETAIL
  40 namespace detail { namespace centroid
  41 {
  42
  43
  44 // NOTE: There is no need to translate in other coordinate systems than
  45 // cartesian. But if it was needed then one should translate using
  46 // CS-specific technique, e.g. in spherical/geographic a translation
  47 // vector should contain coordinates being multiplies of 2PI or 360 deg.
  48 template <typename Geometry,
  49           typename CastedTag = typename tag_cast
  50                                 <
  51                                     typename tag<Geometry>::type,
  52                                     areal_tag
  53                                 >::type,
  54     typename CSTag = typename cs_tag<Geometry>::type>
  55 struct translating_transformer
  56 {
  57     typedef typename geometry::point_type<Geometry>::type point_type;
  58     typedef boost::reference_wrapper<point_type const> result_type;
  59
  60     explicit translating_transformer(Geometry const&) {}
  61     explicit translating_transformer(point_type const&) {}
  62
  63     result_type apply(point_type const& pt) const
  64     {
  65         return result_type(pt);
  66     }
  67
  68     template <typename ResPt>
  69     void apply_reverse(ResPt &) const {}
  70 };
  71
  72 // Specialization for Areal Geometries in cartesian CS
  73 template <typename Geometry>
  74 struct translating_transformer<Geometry, areal_tag, cartesian_tag>
  75 {
  76     typedef typename geometry::point_type<Geometry>::type point_type;
  77     typedef point_type result_type;
  78
  79     explicit translating_transformer(Geometry const& geom)
  80         : m_origin(NULL)
  81     {
  82         geometry::point_iterator<Geometry const>
  83             pt_it = geometry::points_begin(geom);
  84         if ( pt_it != geometry::points_end(geom) )
  85         {
  86             m_origin = boost::addressof(*pt_it);
  87         }
  88     }
  89
  90     explicit translating_transformer(point_type const& origin)
  91         : m_origin(boost::addressof(origin))
  92     {}
  93
  94     result_type apply(point_type const& pt) const
  95     {
  96         point_type res = pt;
  97         if ( m_origin )
  98             geometry::subtract_point(res, *m_origin);
  99         return res;
 100     }
 101
 102     template <typename ResPt>
 103     void apply_reverse(ResPt & res_pt) const
 104     {
 105         if ( m_origin )
 106             geometry::add_point(res_pt, *m_origin);
 107     }
 108
 109     const point_type * m_origin;
 110 };
 111
 112
 113 }} // namespace detail::centroid
 114 #endif // DOXYGEN_NO_DETAIL
 115
 116 }} // namespace boost::geometry
 117
 118
 119 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_CENTROID_TRANSLATING_TRANSFORMER_HPP