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https://github.com/libretro/scummvm.git
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53 lines
1.5 KiB
C++
53 lines
1.5 KiB
C++
/* ScummVM - Graphic Adventure Engine
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*
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* ScummVM is the legal property of its developers, whose names
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* are too numerous to list here. Please refer to the COPYRIGHT
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* file distributed with this source distribution.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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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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* 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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*/
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// Based on eos' sine tables
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#include "common/scummsys.h"
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#include "common/sinetables.h"
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namespace Common {
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SineTable::SineTable(int bitPrecision) {
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assert((bitPrecision >= 4) && (bitPrecision <= 16));
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_bitPrecision = bitPrecision;
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int m = 1 << _bitPrecision;
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double freq = 2 * M_PI / m;
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_table = new float[m];
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// Table contains sin(2*pi*x/n) for 0<=x<=n/4,
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// followed by its reverse
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for (int i = 0; i <= m / 4; i++)
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_table[i] = sin(i * freq);
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for (int i = 1; i < m / 4; i++)
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_table[m / 2 - i] = _table[i];
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}
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SineTable::~SineTable() {
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delete[] _table;
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}
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} // End of namespace Common
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