scummvm/engines/agi/sound_pcjr.h
2011-02-09 01:09:01 +00:00

128 lines
2.6 KiB
C++

/* 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.
*
* $URL$
* $Id$
*
*/
#ifndef AGI_SOUND_PCJR_H
#define AGI_SOUND_PCJR_H
#include "audio/audiostream.h"
namespace Agi {
#define CHAN_MAX 4
#define SAMPLE_RATE 22050
enum GenType {
kGenSilence,
kGenTone,
kGenPeriod,
kGenWhite
};
struct SndGenChan {
const byte *data;
uint16 duration;
uint16 avail; // turned on (1) but when the channel's data runs out, it's set to (0)
uint16 dissolveCount;
byte attenuation;
byte attenuationCopy;
GenType genType;
// for the sample mixer
int freqCount;
};
struct ToneChan {
int avail;
int noteCount; // length of tone.. duration
int freqCount;
int freqCountPrev;
int atten; // volume
GenType genType;
int genTypePrev;
int count;
int scale;
int sign;
unsigned int noiseState; /* noise generator */
int feedback; /* noise feedback mask */
};
struct Tone {
int freqCount;
int atten;
GenType type;
};
class SoundGenPCJr : public SoundGen, public Audio::AudioStream {
public:
SoundGenPCJr(AgiEngine *vm, Audio::Mixer *pMixer);
~SoundGenPCJr();
void play(int resnum);
void stop(void);
// AudioStream API
int readBuffer(int16 *buffer, const int numSamples);
bool isStereo() const {
return false;
}
bool endOfData() const {
return false;
}
int getRate() const {
// FIXME: Ideally, we should use _sampleRate.
return 22050;
}
private:
int getNextNote(int ch, Tone *tone);
int volumeCalc(SndGenChan *chan);
int chanGen(int chan, int16 *stream, int len);
int fillNoise(ToneChan *t, int16 *buf, int len);
int fillSquare(ToneChan *t, int16 *buf, int len);
private:
SndGenChan _channel[CHAN_MAX];
ToneChan _tchannel[CHAN_MAX];
int16 *_chanData;
int _chanAllocated;
int _dissolveMethod;
};
} // End of namespace Agi
#endif /* AGI_SOUND_PCJR_H */