ceph/src/boost/boost/geometry/strategies/cartesian/centroid_average.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) 2017 Adam Wulkiewicz, Lodz, Poland.
   7
   8 // This file was modified by Oracle on 2015-2021.
   9 // Modifications copyright (c) 2015-2021 Oracle and/or its affiliates.
  10
  11 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
  12
  13 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
  14 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
  15
  16 // Use, modification and distribution is subject to the Boost Software License,
  17 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  18 // http://www.boost.org/LICENSE_1_0.txt)
  19
  20 #ifndef BOOST_GEOMETRY_STRATEGIES_CARTESIAN_CENTROID_AVERAGE_HPP
  21 #define BOOST_GEOMETRY_STRATEGIES_CARTESIAN_CENTROID_AVERAGE_HPP
  22
  23
  24 #include <cstddef>
  25
  26 #include <boost/geometry/algorithms/assign.hpp>
  27 #include <boost/geometry/algorithms/detail/signed_size_type.hpp>
  28 #include <boost/geometry/arithmetic/arithmetic.hpp>
  29 #include <boost/geometry/core/coordinate_type.hpp>
  30 #include <boost/geometry/core/point_type.hpp>
  31 #include <boost/geometry/strategies/centroid.hpp>
  32
  33
  34 namespace boost { namespace geometry
  35 {
  36
  37 namespace strategy { namespace centroid
  38 {
  39
  40
  41 /*!
  42 \brief Centroid calculation taking average of points
  43 \ingroup strategies
  44 */
  45 template
  46 <
  47     typename Ignored1 = void,
  48     typename Ignored2 = void
  49 >
  50 class average
  51 {
  52 private :
  53
  54     /*! subclass to keep state */
  55     template <typename GeometryPoint, typename ResultPoint>
  56     class sum
  57     {
  58         friend class average;
  59         signed_size_type count;
  60         ResultPoint centroid;
  61
  62     public :
  63         inline sum()
  64             : count(0)
  65         {
  66             assign_zero(centroid);
  67         }
  68     };
  69
  70 public :
  71     template <typename GeometryPoint, typename ResultPoint>
  72     struct state_type
  73     {
  74         typedef sum<GeometryPoint, ResultPoint> type;
  75     };
  76
  77     template <typename GeometryPoint, typename ResultPoint>
  78     static inline void apply(GeometryPoint const& p,
  79                              sum<GeometryPoint, ResultPoint>& state)
  80     {
  81         add_point(state.centroid, p);
  82         state.count++;
  83     }
  84
  85     template <typename GeometryPoint, typename ResultPoint>
  86     static inline bool result(sum<GeometryPoint, ResultPoint> const& state,
  87                               ResultPoint& centroid)
  88     {
  89         centroid = state.centroid;
  90         if ( state.count > 0 )
  91         {
  92             divide_value(centroid, state.count);
  93             return true;
  94         }
  95         return false;
  96     }
  97
  98 };
  99
 100
 101 #ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
 102
 103
 104 namespace services
 105 {
 106
 107 template <typename Point, std::size_t DimensionCount, typename Geometry>
 108 struct default_strategy
 109 <
 110     cartesian_tag,
 111     pointlike_tag,
 112     DimensionCount,
 113     Point,
 114     Geometry
 115 >
 116 {
 117     typedef average
 118         <
 119             Point,
 120             typename point_type<Geometry>::type
 121         > type;
 122 };
 123
 124 } // namespace services
 125
 126 #endif
 127
 128
 129 }} // namespace strategy::centroid
 130
 131
 132 }} // namespace boost::geometry
 133
 134
 135 #endif // BOOST_GEOMETRY_STRATEGIES_CARTESIAN_CENTROID_AVERAGE_HPP