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Diffstat (limited to 'boost/geometry/strategies/geographic/mapping_ssf.hpp')
| -rw-r--r-- | boost/geometry/strategies/geographic/mapping_ssf.hpp | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/boost/geometry/strategies/geographic/mapping_ssf.hpp b/boost/geometry/strategies/geographic/mapping_ssf.hpp new file mode 100644 index 0000000000..3beedc7809 --- /dev/null +++ b/boost/geometry/strategies/geographic/mapping_ssf.hpp @@ -0,0 +1,185 @@ +// Boost.Geometry (aka GGL, Generic Geometry Library) + +// Copyright (c) 2011-2012 Barend Gehrels, Amsterdam, the Netherlands. + +// This file was modified by Oracle on 2014. +// Modifications copyright (c) 2014 Oracle and/or its affiliates. + +// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle + +// Use, modification and distribution is subject to the Boost Software License, +// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt) + +#ifndef BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_MAPPING_SSF_HPP +#define BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_MAPPING_SSF_HPP + + +#include <boost/core/ignore_unused.hpp> + +#include <boost/geometry/core/radius.hpp> + +#include <boost/geometry/util/math.hpp> +#include <boost/geometry/util/promote_floating_point.hpp> +#include <boost/geometry/util/select_calculation_type.hpp> + +#include <boost/geometry/strategies/side.hpp> +#include <boost/geometry/strategies/spherical/ssf.hpp> + + +namespace boost { namespace geometry +{ + +namespace strategy { namespace side +{ + + +// An enumeration type defining types of mapping of geographical +// latitude to spherical latitude. +// See: http://en.wikipedia.org/wiki/Great_ellipse +// http://en.wikipedia.org/wiki/Latitude#Auxiliary_latitudes +enum mapping_type { mapping_geodetic, mapping_reduced, mapping_geocentric }; + + +#ifndef DOXYGEN_NO_DETAIL +namespace detail +{ + +template <typename Spheroid, mapping_type Mapping> +struct mapper +{ + explicit inline mapper(Spheroid const& /*spheroid*/) {} + + template <typename CalculationType> + static inline CalculationType const& apply(CalculationType const& lat) + { + return lat; + } +}; + +template <typename Spheroid> +struct mapper<Spheroid, mapping_reduced> +{ + typedef typename promote_floating_point + < + typename radius_type<Spheroid>::type + >::type fraction_type; + + explicit inline mapper(Spheroid const& spheroid) + { + fraction_type const a = geometry::get_radius<0>(spheroid); + fraction_type const b = geometry::get_radius<2>(spheroid); + b_div_a = b / a; + } + + template <typename CalculationType> + inline CalculationType apply(CalculationType const& lat) const + { + return atan(static_cast<CalculationType>(b_div_a) * tan(lat)); + } + + fraction_type b_div_a; +}; + +template <typename Spheroid> +struct mapper<Spheroid, mapping_geocentric> +{ + typedef typename promote_floating_point + < + typename radius_type<Spheroid>::type + >::type fraction_type; + + explicit inline mapper(Spheroid const& spheroid) + { + fraction_type const a = geometry::get_radius<0>(spheroid); + fraction_type const b = geometry::get_radius<2>(spheroid); + sqr_b_div_a = b / a; + sqr_b_div_a *= sqr_b_div_a; + } + + template <typename CalculationType> + inline CalculationType apply(CalculationType const& lat) const + { + return atan(static_cast<CalculationType>(sqr_b_div_a) * tan(lat)); + } + + fraction_type sqr_b_div_a; +}; + +} +#endif // DOXYGEN_NO_DETAIL + + +/*! +\brief Check at which side of a geographical segment a point lies + left of segment (> 0), right of segment (< 0), on segment (0). + The check is performed by mapping the geographical coordinates + to spherical coordinates and using spherical_side_formula. +\ingroup strategies +\tparam Spheroid The reference spheroid model +\tparam Mapping The type of mapping of geographical to spherical latitude +\tparam CalculationType \tparam_calculation + */ +template <typename Spheroid, + mapping_type Mapping = mapping_geodetic, + typename CalculationType = void> +class mapping_spherical_side_formula +{ + +public : + inline mapping_spherical_side_formula() + : m_mapper(Spheroid()) + {} + + explicit inline mapping_spherical_side_formula(Spheroid const& spheroid) + : m_mapper(spheroid) + {} + + template <typename P1, typename P2, typename P> + inline int apply(P1 const& p1, P2 const& p2, P const& p) + { + typedef typename promote_floating_point + < + typename select_calculation_type_alt + < + CalculationType, + P1, P2, P + >::type + >::type calculation_type; + + calculation_type lon1 = get_as_radian<0>(p1); + calculation_type lat1 = m_mapper.template apply<calculation_type>(get_as_radian<1>(p1)); + calculation_type lon2 = get_as_radian<0>(p2); + calculation_type lat2 = m_mapper.template apply<calculation_type>(get_as_radian<1>(p2)); + calculation_type lon = get_as_radian<0>(p); + calculation_type lat = m_mapper.template apply<calculation_type>(get_as_radian<1>(p)); + + return detail::spherical_side_formula(lon1, lat1, lon2, lat2, lon, lat); + } + +private: + side::detail::mapper<Spheroid, Mapping> const m_mapper; +}; + +// The specialization for geodetic latitude which can be used directly +template <typename Spheroid, + typename CalculationType> +class mapping_spherical_side_formula<Spheroid, mapping_geodetic, CalculationType> +{ + +public : + inline mapping_spherical_side_formula() {} + explicit inline mapping_spherical_side_formula(Spheroid const& /*spheroid*/) {} + + template <typename P1, typename P2, typename P> + static inline int apply(P1 const& p1, P2 const& p2, P const& p) + { + return spherical_side_formula<CalculationType>::apply(p1, p2, p); + } +}; + +}} // namespace strategy::side + +}} // namespace boost::geometry + +#endif // BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_MAPPING_SSF_HPP |