views/detail/two_dimensional_view.hpp

0001 // Boost.Geometry (aka GGL, Generic Geometry Library)
0002
0003 // Copyright (c) 2015-2020, Oracle and/or its affiliates.
0004
0005 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
0006 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
0007
0008 // Licensed under the Boost Software License version 1.0.
0009 // http://www.boost.org/users/license.html
0010
0011 #ifndef BOOST_GEOMETRY_VIEWS_DETAIL_TWO_DIMENSIONAL_VIEW_HPP
0012 #define BOOST_GEOMETRY_VIEWS_DETAIL_TWO_DIMENSIONAL_VIEW_HPP
0013
0014 #include <cstddef>
0015
0016 #include <boost/geometry/core/access.hpp>
0017 #include <boost/geometry/core/coordinate_type.hpp>
0018 #include <boost/geometry/core/coordinate_system.hpp>
0019 #include <boost/geometry/core/coordinate_dimension.hpp>
0020 #include <boost/geometry/core/point_type.hpp>
0021 #include <boost/geometry/core/static_assert.hpp>
0022 #include <boost/geometry/core/tag.hpp>
0023 #include <boost/geometry/core/tags.hpp>
0024
0025 #include <boost/geometry/algorithms/not_implemented.hpp>
0026
0027
0028 namespace boost { namespace geometry
0029 {
0030
0031 #ifndef DOXYGEN_NO_DETAIL
0032 namespace detail
0033 {
0034
0035 template
0036 <
0037     typename Geometry,
0038     std::size_t Dimension1 = 0,
0039     std::size_t Dimension2 = 1,
0040     typename Tag = typename tag<Geometry>::type
0041 >
0042 struct two_dimensional_view
0043     : not_implemented<Tag>
0044 {};
0045
0046
0047 // View that enables to choose two dimensions of a point and see it as
0048 // a two-dimensional point
0049 template <typename Point, std::size_t Dimension1, std::size_t Dimension2>
0050 struct two_dimensional_view<Point, Dimension1, Dimension2, point_tag>
0051 {
0052     BOOST_GEOMETRY_STATIC_ASSERT(
0053         (Dimension1 < dimension<Point>::value),
0054         "Coordinate Dimension1 is larger than Point's dimension.",
0055         std::integral_constant<std::size_t, Dimension1>);
0056
0057     BOOST_GEOMETRY_STATIC_ASSERT(
0058         (Dimension2 < dimension<Point>::value),
0059         "Coordinate Dimension2 is larger than Point's dimension.",
0060         std::integral_constant<std::size_t, Dimension2>);
0061
0062     two_dimensional_view(Point& point)
0063         : m_point(point)
0064     {}
0065
0066     Point& m_point;
0067 };
0068
0069
0070 } // namespace detail
0071 #endif // DOXYGEN_NO_DETAIL
0072
0073
0074 #ifndef DOXYGEN_NO_TRAITS_SPECIALIZATIONS
0075 namespace traits
0076 {
0077
0078
0079 template <typename Point, std::size_t Dimension1, std::size_t Dimension2>
0080 struct tag
0081     <
0082         geometry::detail::two_dimensional_view
0083             <
0084                 Point, Dimension1, Dimension2, point_tag
0085             >
0086     >
0087 {
0088     typedef point_tag type;
0089 };
0090
0091 template <typename Point, std::size_t Dimension1, std::size_t Dimension2>
0092 struct coordinate_system
0093     <
0094         geometry::detail::two_dimensional_view
0095             <
0096                 Point, Dimension1, Dimension2, point_tag
0097             >
0098     > : coordinate_system<typename geometry::point_type<Point>::type>
0099 {};
0100
0101 template <typename Point, std::size_t Dimension1, std::size_t Dimension2>
0102 struct coordinate_type
0103     <
0104         geometry::detail::two_dimensional_view
0105             <
0106                 Point, Dimension1, Dimension2, point_tag
0107             >
0108     > : coordinate_type<typename geometry::point_type<Point>::type>
0109 {};
0110
0111 template <typename Point, std::size_t Dimension1, std::size_t Dimension2>
0112 struct dimension
0113     <
0114         geometry::detail::two_dimensional_view
0115             <
0116                 Point, Dimension1, Dimension2, point_tag
0117             >
0118     > : std::integral_constant<std::size_t, 2>
0119 {};
0120
0121 template <typename Point, std::size_t Dimension1, std::size_t Dimension2>
0122 struct point_type
0123     <
0124         geometry::detail::two_dimensional_view
0125             <
0126                 Point, Dimension1, Dimension2, point_tag
0127             >
0128     >
0129 {
0130     typedef typename geometry::point_type<Point>::type type;
0131 };
0132
0133
0134 template <typename Point, std::size_t Dimension1, std::size_t Dimension2>
0135 struct access
0136     <
0137         geometry::detail::two_dimensional_view
0138             <
0139                 Point, Dimension1, Dimension2, point_tag
0140             >,
0141         0
0142     >
0143 {
0144     typedef typename geometry::coordinate_type<Point>::type coordinate_type;
0145     typedef geometry::detail::two_dimensional_view
0146         <
0147             Point, Dimension1, Dimension2, point_tag
0148         > view_type;
0149
0150     static inline coordinate_type get(view_type const& view)
0151     {
0152         return geometry::get<Dimension1>(view.m_point);
0153     }
0154
0155     static inline void set(view_type& view, coordinate_type const& value)
0156     {
0157         geometry::set<Dimension1>(view.m_point, value);
0158     }
0159 };
0160
0161 template <typename Point, std::size_t Dimension1, std::size_t Dimension2>
0162 struct access
0163     <
0164         geometry::detail::two_dimensional_view
0165             <
0166                 Point, Dimension1, Dimension2, point_tag
0167             >,
0168         1
0169     >
0170 {
0171     typedef typename geometry::coordinate_type<Point>::type coordinate_type;
0172     typedef geometry::detail::two_dimensional_view
0173         <
0174             Point, Dimension1, Dimension2, point_tag
0175         > view_type;
0176
0177     static inline coordinate_type get(view_type const& view)
0178     {
0179         return geometry::get<Dimension2>(view.m_point);
0180     }
0181
0182     static inline void set(view_type& view, coordinate_type const& value)
0183     {
0184         geometry::set<Dimension2>(view.m_point, value);
0185     }
0186 };
0187
0188
0189 } // namespace traits
0190 #endif // DOXYGEN_NO_TRAITS_SPECIALIZATIONS
0191
0192 }} // namespace boost::geometry
0193
0194
0195 #endif // BOOST_GEOMETRY_VIEWS_DETAIL_TWO_DIMENSIONAL_VIEW_HPP