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Diffstat (limited to 'boost/geometry/formulas/eccentricity_sqr.hpp')
-rw-r--r-- | boost/geometry/formulas/eccentricity_sqr.hpp | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/boost/geometry/formulas/eccentricity_sqr.hpp b/boost/geometry/formulas/eccentricity_sqr.hpp new file mode 100644 index 0000000000..01a9beacb9 --- /dev/null +++ b/boost/geometry/formulas/eccentricity_sqr.hpp @@ -0,0 +1,70 @@ +// Boost.Geometry + +// Copyright (c) 2016 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_FORMULAS_ECCENCRICITY_SQR_HPP +#define BOOST_GEOMETRY_FORMULAS_ECCENCRICITY_SQR_HPP + +#include <boost/geometry/core/radius.hpp> +#include <boost/geometry/core/tag.hpp> +#include <boost/geometry/core/tags.hpp> + +#include <boost/geometry/algorithms/not_implemented.hpp> + +namespace boost { namespace geometry +{ + +#ifndef DOXYGEN_NO_DISPATCH +namespace formula_dispatch +{ + +template <typename ResultType, typename Geometry, typename Tag = typename tag<Geometry>::type> +struct eccentricity_sqr + : not_implemented<Tag> +{}; + +template <typename ResultType, typename Geometry> +struct eccentricity_sqr<ResultType, Geometry, srs_sphere_tag> +{ + static inline ResultType apply(Geometry const& /*geometry*/) + { + return ResultType(0); + } +}; + +template <typename ResultType, typename Geometry> +struct eccentricity_sqr<ResultType, Geometry, srs_spheroid_tag> +{ + static inline ResultType apply(Geometry const& geometry) + { + // 1 - (b / a)^2 + return ResultType(1) - math::sqr(ResultType(get_radius<2>(geometry)) + / ResultType(get_radius<0>(geometry))); + } +}; + +} // namespace formula_dispatch +#endif // DOXYGEN_NO_DISPATCH + +#ifndef DOXYGEN_NO_DETAIL +namespace formula +{ + +template <typename ResultType, typename Geometry> +ResultType eccentricity_sqr(Geometry const& geometry) +{ + return formula_dispatch::eccentricity_sqr<ResultType, Geometry>::apply(geometry); +} + +} // namespace formula +#endif // DOXYGEN_NO_DETAIL + +}} // namespace boost::geometry + +#endif // BOOST_GEOMETRY_FORMULAS_ECCENCRICITY_SQR_HPP |