strategies/geographic/densify.hpp

0001 // Boost.Geometry
0002
0003 // Copyright (c) 2017-2021, Oracle and/or its affiliates.
0004
0005 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
0006
0007 // Licensed under the Boost Software License version 1.0.
0008 // http://www.boost.org/users/license.html
0009
0010 #ifndef BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_DENSIFY_HPP
0011 #define BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_DENSIFY_HPP
0012
0013
0014 #include <boost/geometry/algorithms/detail/convert_point_to_point.hpp>
0015 #include <boost/geometry/algorithms/detail/signed_size_type.hpp>
0016 #include <boost/geometry/core/assert.hpp>
0017 #include <boost/geometry/core/coordinate_dimension.hpp>
0018 #include <boost/geometry/core/coordinate_type.hpp>
0019 #include <boost/geometry/core/radian_access.hpp>
0020 #include <boost/geometry/srs/spheroid.hpp>
0021 #include <boost/geometry/strategies/densify.hpp>
0022 #include <boost/geometry/strategies/geographic/parameters.hpp>
0023 #include <boost/geometry/util/select_most_precise.hpp>
0024
0025
0026 namespace boost { namespace geometry
0027 {
0028
0029 namespace strategy { namespace densify
0030 {
0031
0032
0033 /*!
0034 \brief Densification of geographic segment.
0035 \ingroup strategies
0036 \tparam FormulaPolicy The geodesic formulas used internally.
0037 \tparam Spheroid The spheroid model.
0038 \tparam CalculationType \tparam_calculation
0039
0040 \qbk{
0041 [heading See also]
0042 \* [link geometry.reference.algorithms.densify.densify_4_with_strategy densify (with strategy)]
0043 \* [link geometry.reference.srs.srs_spheroid srs::spheroid]
0044 }
0045  */
0046 template
0047 <
0048     typename FormulaPolicy = strategy::andoyer,
0049     typename Spheroid = srs::spheroid<double>,
0050     typename CalculationType = void
0051 >
0052 class geographic
0053 {
0054 public:
0055     geographic()
0056         : m_spheroid()
0057     {}
0058
0059     explicit geographic(Spheroid const& spheroid)
0060         : m_spheroid(spheroid)
0061     {}
0062
0063     template <typename Point, typename AssignPolicy, typename T>
0064     inline void apply(Point const& p0, Point const& p1, AssignPolicy & policy, T const& length_threshold) const
0065     {
0066         using out_point_t = typename AssignPolicy::point_type;
0067         using calc_t = typename select_most_precise
0068             <
0069                 coordinate_type_t<Point>,
0070                 coordinate_type_t<out_point_t>,
0071                 CalculationType
0072             >::type;
0073
0074         using direct_t = typename FormulaPolicy::template direct<calc_t, true, false, false, false>;
0075         using inverse_t = typename FormulaPolicy::template inverse<calc_t, true, true, false, false, false>;
0076
0077         typename inverse_t::result_type
0078             inv_r = inverse_t::apply(get_as_radian<0>(p0), get_as_radian<1>(p0),
0079                                      get_as_radian<0>(p1), get_as_radian<1>(p1),
0080                                      m_spheroid);
0081
0082         BOOST_GEOMETRY_ASSERT(length_threshold > T(0));
0083
0084         signed_size_type n = signed_size_type(inv_r.distance / length_threshold);
0085         if (n <= 0)
0086             return;
0087
0088         calc_t step = inv_r.distance / (n + 1);
0089
0090         calc_t current = step;
0091         for (signed_size_type i = 0 ; i < n ; ++i, current += step)
0092         {
0093             typename direct_t::result_type
0094                 dir_r = direct_t::apply(get_as_radian<0>(p0), get_as_radian<1>(p0),
0095                                         current, inv_r.azimuth,
0096                                         m_spheroid);
0097
0098             out_point_t p;
0099             set_from_radian<0>(p, dir_r.lon2);
0100             set_from_radian<1>(p, dir_r.lat2);
0101             geometry::detail::conversion::point_to_point
0102                 <
0103                     Point, out_point_t,
0104                     2, dimension<out_point_t>::value
0105                 >::apply(p0, p);
0106
0107             policy.apply(p);
0108         }
0109     }
0110
0111     inline Spheroid const& model() const
0112     {
0113         return m_spheroid;
0114     }
0115
0116 private:
0117     Spheroid m_spheroid;
0118 };
0119
0120
0121 #ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
0122 namespace services
0123 {
0124
0125 template <>
0126 struct default_strategy<geographic_tag>
0127 {
0128     typedef strategy::densify::geographic<> type;
0129 };
0130
0131
0132 } // namespace services
0133 #endif // DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
0134
0135
0136 }} // namespace strategy::densify
0137
0138
0139 }} // namespace boost::geometry
0140
0141 #endif // BOOST_GEOMETRY_ALGORITHMS_DENSIFY_HPP