79 lines
1.9 KiB
Plaintext
79 lines
1.9 KiB
Plaintext
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/*
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* This file is part of libsidplayfp, a SID player engine.
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*
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* Copyright 2011-2014 Leandro Nini <drfiemost@users.sourceforge.net>
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* Copyright 2007-2010 Antti Lankila
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program 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
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#ifndef SPLINE_H
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#define SPLINE_H
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#include <cstddef>
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#include <vector>
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namespace reSIDfp
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{
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/**
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* Fritsch-Carlson monotone cubic spline interpolation.
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*
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* Based on the implementation from the [Monotone cubic interpolation] wikipedia page.
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*
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* [Monotone cubic interpolation]: https://en.wikipedia.org/wiki/Monotone_cubic_interpolation
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*/
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class Spline
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{
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public:
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typedef struct
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{
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double x;
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double y;
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} Point;
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private:
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typedef struct
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{
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double x1;
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double x2;
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double a;
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double b;
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double c;
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double d;
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} Param;
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typedef std::vector<Param> ParamVector;
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private:
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/// Interpolation parameters
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ParamVector params;
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/// last used parameters, cached for speed up
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ParamVector::const_pointer c;
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public:
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Spline(const Point input[], size_t inputLength);
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/**
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* Evaluate y and its derivative at given point x.
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*/
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Point evaluate(double x);
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};
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} // namespace reSIDfp
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#endif
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