detail/is_valid/box.hpp

0001 // Boost.Geometry (aka GGL, Generic Geometry Library)
0002
0003 // Copyright (c) 2014-2017, 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_ALGORITHMS_DETAIL_IS_VALID_BOX_HPP
0012 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_BOX_HPP
0013
0014 #include <cstddef>
0015
0016 #include <boost/core/ignore_unused.hpp>
0017
0018 #include <boost/geometry/core/access.hpp>
0019 #include <boost/geometry/core/tags.hpp>
0020 #include <boost/geometry/core/coordinate_dimension.hpp>
0021
0022 #include <boost/geometry/algorithms/validity_failure_type.hpp>
0023 #include <boost/geometry/algorithms/detail/is_valid/has_invalid_coordinate.hpp>
0024 #include <boost/geometry/algorithms/dispatch/is_valid.hpp>
0025
0026
0027 namespace boost { namespace geometry
0028 {
0029
0030
0031 #ifndef DOXYGEN_NO_DETAIL
0032 namespace detail { namespace is_valid
0033 {
0034
0035 template <typename Box, std::size_t I>
0036 struct has_valid_corners
0037 {
0038     template <typename VisitPolicy>
0039     static inline bool apply(Box const& box, VisitPolicy& visitor)
0040     {
0041         if (math::equals(geometry::get<geometry::min_corner, I-1>(box),
0042                          geometry::get<geometry::max_corner, I-1>(box)))
0043         {
0044             return
0045                 visitor.template apply<failure_wrong_topological_dimension>();
0046         }
0047         else if (geometry::get<geometry::min_corner, I-1>(box)
0048                  >
0049                  geometry::get<geometry::max_corner, I-1>(box))
0050         {
0051             return visitor.template apply<failure_wrong_corner_order>();
0052         }
0053         return has_valid_corners<Box, I-1>::apply(box, visitor);
0054     }
0055 };
0056
0057
0058 template <typename Box>
0059 struct has_valid_corners<Box, 0>
0060 {
0061     template <typename VisitPolicy>
0062     static inline bool apply(Box const&, VisitPolicy& visitor)
0063     {
0064         boost::ignore_unused(visitor);
0065
0066         return visitor.template apply<no_failure>();
0067     }
0068 };
0069
0070
0071 template <typename Box>
0072 struct is_valid_box
0073 {
0074     template <typename VisitPolicy, typename Strategy>
0075     static inline bool apply(Box const& box, VisitPolicy& visitor, Strategy const&)
0076     {
0077         return
0078             ! has_invalid_coordinate<Box>::apply(box, visitor)
0079             &&
0080             has_valid_corners<Box, dimension<Box>::value>::apply(box, visitor);
0081     }
0082 };
0083
0084 }} // namespace detail::is_valid
0085 #endif // DOXYGEN_NO_DETAIL
0086
0087
0088
0089 #ifndef DOXYGEN_NO_DISPATCH
0090 namespace dispatch
0091 {
0092
0093
0094 // A box is always simple
0095 // A box is a Polygon, and it satisfies the conditions for Polygon validity.
0096 //
0097 // The only thing we have to check is whether the max corner lies in
0098 // the upper-right quadrant as defined by the min corner
0099 //
0100 // Reference (for polygon validity): OGC 06-103r4 (6.1.11.1)
0101 template <typename Box>
0102 struct is_valid<Box, box_tag>
0103     : detail::is_valid::is_valid_box<Box>
0104 {};
0105
0106
0107 } // namespace dispatch
0108 #endif // DOXYGEN_NO_DISPATCH
0109
0110
0111
0112 }} // namespace boost::geometry
0113
0114
0115 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_BOX_HPP