ceph/src/boost/libs/geometry/include/boost/geometry/geometries/helper_geometry.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2015, Oracle and/or its affiliates.
   4
   5 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
   6
   7 // Licensed under the Boost Software License version 1.0.
   8 // http://www.boost.org/users/license.html
   9
  10 #ifndef BOOST_GEOMETRY_GEOMETRIES_HELPER_GEOMETRY_HPP
  11 #define BOOST_GEOMETRY_GEOMETRIES_HELPER_GEOMETRY_HPP
  12
  13 #include <boost/geometry/core/cs.hpp>
  14 #include <boost/geometry/core/coordinate_dimension.hpp>
  15 #include <boost/geometry/core/coordinate_type.hpp>
  16 #include <boost/geometry/core/point_type.hpp>
  17 #include <boost/geometry/core/tag.hpp>
  18 #include <boost/geometry/core/tags.hpp>
  19
  20 #include <boost/geometry/geometries/box.hpp>
  21 #include <boost/geometry/geometries/point.hpp>
  22
  23 #include <boost/geometry/algorithms/not_implemented.hpp>
  24
  25
  26 namespace boost { namespace geometry
  27 {
  28
  29 namespace detail { namespace helper_geometries
  30 {
  31
  32 template <typename Geometry, typename CS_Tag = typename cs_tag<Geometry>::type>
  33 struct default_units
  34 {
  35     typedef typename coordinate_system<Geometry>::type::units type;
  36 };
  37
  38 // The Cartesian coordinate system does not define the type units.
  39 // For that reason the generic implementation for default_units cannot be used
  40 // and specialization needs to be defined.
  41 // Moreover, it makes sense to define the units for the Cartesian
  42 // coordinate system to be radians, as this way a Cartesian point can
  43 // potentially be used in algorithms taking non-Cartesian strategies
  44 // and work as if it was as point in the non-Cartesian coordinate
  45 // system with radian units.
  46 template <typename Geometry>
  47 struct default_units<Geometry, cartesian_tag>
  48 {
  49     typedef radian type;
  50 };
  51
  52
  53 template <typename Units, typename CS_Tag>
  54 struct cs_tag_to_coordinate_system
  55 {
  56     typedef cs::cartesian type;
  57 };
  58
  59 template <typename Units>
  60 struct cs_tag_to_coordinate_system<Units, spherical_equatorial_tag>
  61 {
  62     typedef cs::spherical_equatorial<Units> type;
  63 };
  64
  65 template <typename Units>
  66 struct cs_tag_to_coordinate_system<Units, spherical_tag>
  67 {
  68     typedef cs::spherical<Units> type;
  69 };
  70
  71 template <typename Units>
  72 struct cs_tag_to_coordinate_system<Units, geographic_tag>
  73 {
  74     typedef cs::geographic<Units> type;
  75 };
  76
  77
  78 template
  79 <
  80     typename Point,
  81     typename NewCoordinateType,
  82     typename NewUnits,
  83     typename CS_Tag = typename cs_tag<Point>::type
  84 >
  85 struct helper_point
  86 {
  87     typedef model::point
  88         <
  89             NewCoordinateType,
  90             dimension<Point>::value,
  91             typename cs_tag_to_coordinate_system<NewUnits, CS_Tag>::type
  92         > type;
  93 };
  94
  95
  96 }} // detail::helper_geometries
  97
  98
  99 namespace detail_dispatch
 100 {
 101
 102
 103 template
 104 <
 105     typename Geometry,
 106     typename NewCoordinateType,
 107     typename NewUnits,
 108     typename Tag = typename tag<Geometry>::type>
 109 struct helper_geometry : not_implemented<Geometry>
 110 {};
 111
 112
 113 template <typename Point, typename NewCoordinateType, typename NewUnits>
 114 struct helper_geometry<Point, NewCoordinateType, NewUnits, point_tag>
 115 {
 116     typedef typename detail::helper_geometries::helper_point
 117         <
 118             Point, NewCoordinateType, NewUnits
 119         >::type type;
 120 };
 121
 122
 123 template <typename Box, typename NewCoordinateType, typename NewUnits>
 124 struct helper_geometry<Box, NewCoordinateType, NewUnits, box_tag>
 125 {
 126     typedef model::box
 127         <
 128             typename helper_geometry
 129                 <
 130                     typename point_type<Box>::type, NewCoordinateType, NewUnits
 131                 >::type
 132         > type;
 133 };
 134
 135
 136 } // detail_dispatch
 137
 138
 139 // Meta-function that provides a new helper geometry of the same kind as
 140 // the input geometry and the same coordinate system type,
 141 // but with a possibly different coordinate type and coordinate system units
 142 template
 143 <
 144     typename Geometry,
 145     typename NewCoordinateType = typename coordinate_type<Geometry>::type,
 146     typename NewUnits = typename detail::helper_geometries::default_units
 147         <
 148             Geometry
 149         >::type
 150 >
 151 struct helper_geometry
 152 {
 153     typedef typename detail_dispatch::helper_geometry
 154         <
 155             Geometry, NewCoordinateType, NewUnits
 156         >::type type;
 157 };
 158
 159
 160 }} // namespace boost::geometry
 161
 162 #endif // BOOST_GEOMETRY_GEOMETRIES_HELPER_GEOMETRY_HPP