ceph/src/boost/boost/geometry/algorithms/detail/azimuth.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4
   5 // This file was modified by Oracle on 2014, 2016, 2017.
   6 // Modifications copyright (c) 2014-2017, Oracle and/or its affiliates.
   7
   8 // Contributed and/or modified by Vissarion Fysikopoulos, on behalf of Oracle
   9 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
  10
  11 // Use, modification and distribution is subject to the Boost Software License,
  12 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  13 // http://www.boost.org/LICENSE_1_0.txt)
  14
  15 #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_AZIMUTH_HPP
  16 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_AZIMUTH_HPP
  17
  18 #include <boost/geometry/core/cs.hpp>
  19 #include <boost/geometry/core/access.hpp>
  20 #include <boost/geometry/core/radian_access.hpp>
  21 #include <boost/geometry/core/tags.hpp>
  22
  23 #include <boost/geometry/util/math.hpp>
  24
  25 #include <boost/geometry/algorithms/not_implemented.hpp>
  26
  27 #include <boost/geometry/formulas/spherical.hpp>
  28 #include <boost/geometry/formulas/vincenty_inverse.hpp>
  29
  30 namespace boost { namespace geometry
  31 {
  32
  33 // An azimuth is an angle between a vector/segment from origin to a point of
  34 // interest and a reference vector. Typically north-based azimuth is used.
  35 // North direction is used as a reference, angle is measured clockwise
  36 // (North - 0deg, East - 90deg). For consistency in 2d cartesian CS
  37 // the reference vector is Y axis, angle is measured clockwise.
  38 // http://en.wikipedia.org/wiki/Azimuth
  39
  40 #ifndef DOXYGEN_NO_DISPATCH
  41 namespace detail_dispatch
  42 {
  43
  44 template <typename ReturnType, typename Tag>
  45 struct azimuth
  46     : not_implemented<Tag>
  47 {};
  48
  49 template <typename ReturnType>
  50 struct azimuth<ReturnType, geographic_tag>
  51 {
  52     template <typename P1, typename P2, typename Spheroid>
  53     static inline ReturnType apply(P1 const& p1, P2 const& p2, Spheroid const& spheroid)
  54     {
  55         return geometry::formula::vincenty_inverse<ReturnType, false, true>().apply
  56                     ( get_as_radian<0>(p1), get_as_radian<1>(p1),
  57                       get_as_radian<0>(p2), get_as_radian<1>(p2),
  58                       spheroid ).azimuth;
  59     }
  60
  61     template <typename P1, typename P2>
  62     static inline ReturnType apply(P1 const& p1, P2 const& p2)
  63     {
  64         return apply(p1, p2, srs::spheroid<ReturnType>());
  65     }
  66 };
  67
  68 template <typename ReturnType>
  69 struct azimuth<ReturnType, spherical_equatorial_tag>
  70 {
  71     template <typename P1, typename P2, typename Sphere>
  72     static inline ReturnType apply(P1 const& p1, P2 const& p2, Sphere const& /*unused*/)
  73     {
  74         return geometry::formula::spherical_azimuth<ReturnType, false>
  75                     ( get_as_radian<0>(p1), get_as_radian<1>(p1),
  76                       get_as_radian<0>(p2), get_as_radian<1>(p2)).azimuth;
  77     }
  78
  79     template <typename P1, typename P2>
  80     static inline ReturnType apply(P1 const& p1, P2 const& p2)
  81     {
  82         return apply(p1, p2, 0); // dummy model
  83     }
  84 };
  85
  86 template <typename ReturnType>
  87 struct azimuth<ReturnType, spherical_polar_tag>
  88     : azimuth<ReturnType, spherical_equatorial_tag>
  89 {};
  90
  91 template <typename ReturnType>
  92 struct azimuth<ReturnType, cartesian_tag>
  93 {
  94     template <typename P1, typename P2, typename Plane>
  95     static inline ReturnType apply(P1 const& p1, P2 const& p2, Plane const& /*unused*/)
  96     {
  97         ReturnType x = get<0>(p2) - get<0>(p1);
  98         ReturnType y = get<1>(p2) - get<1>(p1);
  99
 100         // NOTE: azimuth 0 is at Y axis, increasing right
 101         // as in spherical/geographic where 0 is at North axis
 102         return atan2(x, y);
 103     }
 104
 105     template <typename P1, typename P2>
 106     static inline ReturnType apply(P1 const& p1, P2 const& p2)
 107     {
 108         return apply(p1, p2, 0); // dummy model
 109     }
 110 };
 111
 112 } // detail_dispatch
 113 #endif // DOXYGEN_NO_DISPATCH
 114
 115 #ifndef DOXYGEN_NO_DETAIL
 116 namespace detail
 117 {
 118
 119 /// Calculate azimuth between two points.
 120 /// The result is in radians.
 121 template <typename ReturnType, typename Point1, typename Point2>
 122 inline ReturnType azimuth(Point1 const& p1, Point2 const& p2)
 123 {
 124     return detail_dispatch::azimuth
 125             <
 126                 ReturnType,
 127                 typename geometry::cs_tag<Point1>::type
 128             >::apply(p1, p2);
 129 }
 130
 131 /// Calculate azimuth between two points.
 132 /// The result is in radians.
 133 template <typename ReturnType, typename Point1, typename Point2, typename Model>
 134 inline ReturnType azimuth(Point1 const& p1, Point2 const& p2, Model const& model)
 135 {
 136     return detail_dispatch::azimuth
 137             <
 138                 ReturnType,
 139                 typename geometry::cs_tag<Point1>::type
 140             >::apply(p1, p2, model);
 141 }
 142
 143 } // namespace detail
 144 #endif // DOXYGEN_NO_DETAIL
 145
 146 }} // namespace boost::geometry
 147
 148 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_AZIMUTH_HPP