rdft.h

/* 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

// Based on xoreos' (I)RDFT code which is in turn
// Based upon the (I)RDFT code in FFmpeg
// Copyright (c) 2009 Alex Converse <alex dot converse at gmail dot com>

#ifndef COMMON_RDFT_H
#define COMMON_RDFT_H

#include "common/scummsys.h"
#include "common/math.h"
#include "common/fft.h"

#include "common/cosinetables.h"
#include "common/sinetables.h"

namespace Common {

class RDFT {
public:
    enum TransformType {
        DFT_R2C,
        IDFT_C2R,
        IDFT_R2C,
        DFT_C2R
    };

    RDFT(int bits, TransformType trans);
    ~RDFT();

    void calc(float *data);

private:
    int _bits;
    int _inverse;
    int _signConvention;

    SineTable _sin;
    CosineTable _cos;
    const float *_tSin;
    const float *_tCos;

    FFT *_fft;
};

} // End of namespace Common

#endif // COMMON_RDFT_H