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Diffstat (limited to 'boost/geometry/srs/projections/impl/pj_qsfn.hpp')
-rw-r--r-- | boost/geometry/srs/projections/impl/pj_qsfn.hpp | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/boost/geometry/srs/projections/impl/pj_qsfn.hpp b/boost/geometry/srs/projections/impl/pj_qsfn.hpp new file mode 100644 index 0000000000..606fab5e4e --- /dev/null +++ b/boost/geometry/srs/projections/impl/pj_qsfn.hpp @@ -0,0 +1,95 @@ +// Boost.Geometry (aka GGL, Generic Geometry Library) +// This file is manually converted from PROJ4 + +// Copyright (c) 2008-2012 Barend Gehrels, Amsterdam, the Netherlands. + +// This file was modified by Oracle on 2017. +// Modifications copyright (c) 2017, 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) + +// This file is converted from PROJ4, http://trac.osgeo.org/proj +// PROJ4 is originally written by Gerald Evenden (then of the USGS) +// PROJ4 is maintained by Frank Warmerdam +// PROJ4 is converted to Geometry Library by Barend Gehrels (Geodan, Amsterdam) + +// Original copyright notice: + +// Permission is hereby granted, free of charge, to any person obtaining a +// copy of this software and associated documentation files (the "Software"), +// to deal in the Software without restriction, including without limitation +// the rights to use, copy, modify, merge, publish, distribute, sublicense, +// and/or sell copies of the Software, and to permit persons to whom the +// Software is furnished to do so, subject to the following conditions: + +// The above copyright notice and this permission notice shall be included +// in all copies or substantial portions of the Software. + +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS +// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL +// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING +// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +// DEALINGS IN THE SOFTWARE. + +#ifndef BOOST_GEOMETRY_PROJECTIONS_PJ_QSFN_HPP +#define BOOST_GEOMETRY_PROJECTIONS_PJ_QSFN_HPP + + +namespace boost { namespace geometry { namespace projections +{ + +namespace detail { + +/* determine small q */ +template <typename T> +inline T pj_qsfn(T const& sinphi, T const& e, T const& one_es) +{ + static const T EPSILON = 1.0e-7; + + if (e >= EPSILON) + { + T con = e * sinphi; + return (one_es * (sinphi / (1. - con * con) - + (.5 / e) * log ((1. - con) / (1. + con)))); + } else + return (sinphi + sinphi); +} + + +static const int MAX_C = 9; + +template <typename T> +struct AUTHALIC +{ + T C[MAX_C], CP[MAX_C], CQ[MAX_C]; +}; + +/** + * @brief determine authalic latitude + * @param[in] phi geographic latitude + * @param[in] a initialized structure pointer + * @return authalic latitude + */ +template <typename T> +inline T proj_qsfn(T const& phi, AUTHALIC<T> const& a) +{ + T s, s2, sum; + int i = MAX_C; + + s = sin(phi); + s2 = s * s; + sum = a.CQ[MAX_C - 1]; + while (--i) sum = a.CQ[i] + s2 * sum; + return(s * sum); +} + +} // namespace detail + +}}} // namespace boost::geometry::projections + +#endif |