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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
// Based on eos' cosine tables
#include "common/cosinetables.h"
#include "common/scummsys.h"
namespace Common {
CosineTable::CosineTable(int bitPrecision) {
assert((bitPrecision >= 4) && (bitPrecision <= 16));
_bitPrecision = bitPrecision;
int m = 1 << _bitPrecision;
double freq = 2 * M_PI / m;
_table = new float[m / 2];
// Table contains cos(2*pi*i/m) for 0<=i<m/4,
// followed by 3m/4<=i<m
for (int i = 0; i <= m / 4; i++)
_table[i] = cos(i * freq);
for (int i = 1; i < m / 4; i++)
_table[m / 2 - i] = _table[i];
}
CosineTable::~CosineTable() {
delete[] _table;
}
} // End of namespace Common
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