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

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2015-2017, Oracle and/or its affiliates.
   4
   5 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
   6 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
   7
   8 // Licensed under the Boost Software License version 1.0.
   9 // http://www.boost.org/users/license.html
  10
  11 #ifndef BOOST_GEOMETRY_GEOMETRIES_HELPER_GEOMETRY_HPP
  12 #define BOOST_GEOMETRY_GEOMETRIES_HELPER_GEOMETRY_HPP
  13
  14 #include <boost/mpl/assert.hpp>
  15
  16 #include <boost/geometry/core/cs.hpp>
  17 #include <boost/geometry/core/coordinate_dimension.hpp>
  18 #include <boost/geometry/core/coordinate_type.hpp>
  19 #include <boost/geometry/core/point_type.hpp>
  20 #include <boost/geometry/core/tag.hpp>
  21 #include <boost/geometry/core/tags.hpp>
  22
  23 #include <boost/geometry/geometries/box.hpp>
  24 #include <boost/geometry/geometries/point.hpp>
  25
  26 #include <boost/geometry/algorithms/not_implemented.hpp>
  27
  28
  29 namespace boost { namespace geometry
  30 {
  31
  32 namespace detail { namespace helper_geometries
  33 {
  34
  35 template <typename Geometry, typename CS_Tag = typename cs_tag<Geometry>::type>
  36 struct default_units
  37 {
  38     typedef typename coordinate_system<Geometry>::type::units type;
  39 };
  40
  41 // The Cartesian coordinate system does not define the type units.
  42 // For that reason the generic implementation for default_units cannot be used
  43 // and specialization needs to be defined.
  44 // Moreover, it makes sense to define the units for the Cartesian
  45 // coordinate system to be radians, as this way a Cartesian point can
  46 // potentially be used in algorithms taking non-Cartesian strategies
  47 // and work as if it was as point in the non-Cartesian coordinate
  48 // system with radian units.
  49 template <typename Geometry>
  50 struct default_units<Geometry, cartesian_tag>
  51 {
  52     typedef radian type;
  53 };
  54
  55
  56 template <typename Units, typename CS_Tag>
  57 struct cs_tag_to_coordinate_system
  58 {
  59     BOOST_MPL_ASSERT_MSG((false),
  60                          NOT_IMPLEMENTED_FOR_THIS_COORDINATE_SYSTEM,
  61                          (types<CS_Tag>));
  62 };
  63
  64 template <typename Units>
  65 struct cs_tag_to_coordinate_system<Units, cartesian_tag>
  66 {
  67     typedef cs::cartesian type;
  68 };
  69
  70 template <typename Units>
  71 struct cs_tag_to_coordinate_system<Units, spherical_equatorial_tag>
  72 {
  73     typedef cs::spherical_equatorial<Units> type;
  74 };
  75
  76 template <typename Units>
  77 struct cs_tag_to_coordinate_system<Units, spherical_polar_tag>
  78 {
  79     typedef cs::spherical<Units> type;
  80 };
  81
  82 template <typename Units>
  83 struct cs_tag_to_coordinate_system<Units, geographic_tag>
  84 {
  85     typedef cs::geographic<Units> type;
  86 };
  87
  88
  89 template
  90 <
  91     typename Point,
  92     typename NewCoordinateType,
  93     typename NewUnits,
  94     typename CS_Tag = typename cs_tag<Point>::type
  95 >
  96 struct helper_point
  97 {
  98     typedef model::point
  99         <
 100             NewCoordinateType,
 101             dimension<Point>::value,
 102             typename cs_tag_to_coordinate_system<NewUnits, CS_Tag>::type
 103         > type;
 104 };
 105
 106
 107 }} // detail::helper_geometries
 108
 109
 110 namespace detail_dispatch
 111 {
 112
 113
 114 template
 115 <
 116     typename Geometry,
 117     typename NewCoordinateType,
 118     typename NewUnits,
 119     typename Tag = typename tag<Geometry>::type>
 120 struct helper_geometry : not_implemented<Geometry>
 121 {};
 122
 123
 124 template <typename Point, typename NewCoordinateType, typename NewUnits>
 125 struct helper_geometry<Point, NewCoordinateType, NewUnits, point_tag>
 126 {
 127     typedef typename detail::helper_geometries::helper_point
 128         <
 129             Point, NewCoordinateType, NewUnits
 130         >::type type;
 131 };
 132
 133
 134 template <typename Box, typename NewCoordinateType, typename NewUnits>
 135 struct helper_geometry<Box, NewCoordinateType, NewUnits, box_tag>
 136 {
 137     typedef model::box
 138         <
 139             typename helper_geometry
 140                 <
 141                     typename point_type<Box>::type, NewCoordinateType, NewUnits
 142                 >::type
 143         > type;
 144 };
 145
 146
 147 } // detail_dispatch
 148
 149
 150 // Meta-function that provides a new helper geometry of the same kind as
 151 // the input geometry and the same coordinate system type,
 152 // but with a possibly different coordinate type and coordinate system units
 153 template
 154 <
 155     typename Geometry,
 156     typename NewCoordinateType = typename coordinate_type<Geometry>::type,
 157     typename NewUnits = typename detail::helper_geometries::default_units
 158         <
 159             Geometry
 160         >::type
 161 >
 162 struct helper_geometry
 163 {
 164     typedef typename detail_dispatch::helper_geometry
 165         <
 166             Geometry, NewCoordinateType, NewUnits
 167         >::type type;
 168 };
 169
 170
 171 }} // namespace boost::geometry
 172
 173 #endif // BOOST_GEOMETRY_GEOMETRIES_HELPER_GEOMETRY_HPP