e7c3d04309
format all files Revert "format all files" This reverts commit 95d5812e49e7f916b68e786596f5a8eb5bcac414. Revert "format some files" This reverts commit ed3c8762d4d828b2b28e7b18809fc33f4f8ccaf5. format all files fix formatting in dir include fix formatting of debug macro
46 lines
1.5 KiB
C++
46 lines
1.5 KiB
C++
/*****************************************************************************
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*
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* This file is part of Mapnik (c++ mapping toolkit)
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*
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* Copyright (C) 2021 Artem Pavlenko
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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*****************************************************************************/
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// mapnik
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#include <mapnik/scale_denominator.hpp>
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#include <mapnik/global.hpp>
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#include <mapnik/well_known_srs.hpp>
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// stl
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#include <cmath>
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namespace mapnik {
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static const double meters_per_degree = EARTH_CIRCUMFERENCE / 360;
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double scale_denominator(double map_scale, bool geographic)
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{
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// Pixel size in meters.
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// Corresponding approximate resolution is 90.71 DPI.
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constexpr double pixel_size = 0.00028;
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double denom = map_scale / pixel_size;
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if (geographic)
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denom *= meters_per_degree;
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return denom;
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}
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} // namespace mapnik
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