59 lines
2.4 KiB
C++
59 lines
2.4 KiB
C++
// Boost.Geometry (aka GGL, Generic Geometry Library)
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// This file is manually converted from PROJ4
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// Copyright (c) 2008-2012 Barend Gehrels, Amsterdam, the Netherlands.
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// This file was modified by Oracle on 2017, 2018.
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// Modifications copyright (c) 2017-2018, Oracle and/or its affiliates.
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// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
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// Use, modification and distribution is subject to the Boost Software License,
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// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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// This file is converted from PROJ4, http://trac.osgeo.org/proj
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// PROJ4 is originally written by Gerald Evenden (then of the USGS)
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// PROJ4 is maintained by Frank Warmerdam
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// PROJ4 is converted to Geometry Library by Barend Gehrels (Geodan, Amsterdam)
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// Original copyright notice:
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// Permission is hereby granted, free of charge, to any person obtaining a
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// copy of this software and associated documentation files (the "Software"),
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// to deal in the Software without restriction, including without limitation
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// the rights to use, copy, modify, merge, publish, distribute, sublicense,
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// and/or sell copies of the Software, and to permit persons to whom the
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// Software is furnished to do so, subject to the following conditions:
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// The above copyright notice and this permission notice shall be included
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// in all copies or substantial portions of the Software.
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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// DEALINGS IN THE SOFTWARE.
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#ifndef BOOST_GEOMETRY_PROJECTIONS_PJ_TSFN_HPP
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#define BOOST_GEOMETRY_PROJECTIONS_PJ_TSFN_HPP
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#include <boost/geometry/util/math.hpp>
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namespace boost { namespace geometry { namespace projections {
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namespace detail {
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/* determine small t */
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template <typename T>
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inline T pj_tsfn(T const& phi, T sinphi, T const& e)
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{
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sinphi *= e;
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return (tan (.5 * (geometry::math::half_pi<T>() - phi)) /
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math::pow((T(1) - sinphi) / (T(1) + sinphi), T(0.5) * e));
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}
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} // namespace detail
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}}} // namespace boost::geometry::projections
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#endif
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