asound.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/>.
 *
 */

#ifndef MADS_NEBULAR_ASOUND_H
#define MADS_NEBULAR_ASOUND_H

#include "audio/fmopl.h"
#include "mads/core/sound_manager.h"

namespace MADS {
namespace RexNebular {

class ASound;

class AdlibChannel {
public:
    ASound *_owner = nullptr;

    int _activeCount = 0;
    int _pitchBend = 0;         // signed pitch-bend offset added to frequency by updateFNumber()
    int _volumeFadeStep = 0;    // signed per-period volume delta applied to _volumeOffset
    int _attenFadeStep = 0;     // signed per-period delta applied to _patchAttenuation
    int _note = 0;              // note byte read from the sound-data stream
    int _sampleIndex = 0;
    int _volume = 0;
    int _noteOffset = 0;        // subtracted from _activeCount to derive _keyOnDelay
    int _keyOnDelay = 0;        // countdown before the key-on bit is cleared (gate time)
    int _volumeFadeCounter = 0; // counts down to 0 before applying _volumeFadeStep
    int _volumeFadeReload = 0;  // reload value for _volumeFadeCounter
    uint8 _attenFadeCounter = 0;// counts down to 0 before applying _attenFadeStep
    int _attenFadeReload = 0;   // reload value for _attenFadeCounter
    int _patchAttenuation = 0;  // per-note attenuation offset added on top of the patch TL
    int _pendingStop = 0;       // non-zero while the channel is fading out to silence
    byte *_ptr1 = nullptr;
    byte *_pSrc = nullptr;
    byte *_innerLoopPtr = nullptr;  // inner-loop restart address (opcode 0)
    byte *_outerLoopPtr = nullptr;  // outer-loop restart address (opcode 1)
    int _innerLoopCount = 0;    // remaining inner-loop iterations (opcode 0)
    int _outerLoopCount = 0;    // remaining outer-loop iterations (opcode 1)
    byte *_soundData = nullptr;
    int _transpose = 0;         // fine-tune offset added into the frequency table lookup
    int _volumeOffset = 0;
    int _octaveTranspose = 0;   // added to _note before the octave/semitone split

    // Extra static per-channel volume trim, confirmed via disassembly
    // comparison to be a third additive term in updateActiveChannel()'s
    // volume sum (volume + volumeOffset + channelAttenuation, clamped to
    // [0, 63]). Only asound.003/asound.004's copy of the shared runtime
    // reads this = 0; it is otherwise always 0, so summing it in unconditionally
    // is harmless for every other driver.
    byte _channelAttenuation = 0;

public:
    static bool _channelsEnabled;
public:
    AdlibChannel() {}

    void reset();
    void enable(int flag);
    void setPtr2(byte *pData);
    void load(byte *pData);
    void check(byte *nullPtr);
};

class AdlibChannelData {
public:
    int _hasNoiseMode; // non-zero if this sample drives the 2-voice noise generator
    int _freqMask;
    int _freqBase;
    int _freqStep;      // per-tick frequency-sweep increment
};

class AdlibSample {
public:
    int _attackRate;
    int _decayRate;
    int _sustainLevel;
    int _releaseRate;
    bool _egTyp;
    bool _ksr;
    int _totalLevel;
    int _scalingLevel;
    int _waveformSelect;
    int _freqMultiple;
    int _feedback;
    bool _ampMod;
    int _vib;
    int _alg;
    int _noiseMode;    // copied into AdlibChannelData::_hasNoiseMode by loadSample()
    int _freqMask;
    int _freqBase;
    int _freqStep;     // copied into AdlibChannelData::_freqStep by loadSample()

    AdlibSample() {
    }
    AdlibSample(Common::SeekableReadStream &s);
};

struct RegisterValue {
    uint8 _regNum;
    uint8 _value;

    RegisterValue(int regNum, int value) {
        _regNum = regNum; _value = value;
    }
};

#define ADLIB_CHANNEL_COUNT 9
#define ADLIB_CHANNEL_MIDWAY 5

class ASound : public SoundDriver {
private:
    OPL::OPL *_opl;
    uint16 _randomSeed;
    int _masterVolume;

    void adlibInit();

    void update();

    void pollChannels();

    void checkChannels();

    void pollActiveChannel();

    void updateOctave();

    void updateChannelState();
    void updateActiveChannel();

    void processSample();

    void updateFNumber();

    void onTimer();

protected:
    int _chanCommandCount;
    int _commandParam;

    virtual void channelCommand(byte *&pSrc, bool &updateFlag) = 0;

    virtual void tickCallback() {
    }

    byte *loadData(int offset) {
        return &_soundData[offset];
    }

    int getDataOffset(byte *ptr) const {
        return ptr - &_soundData[0];
    }

    void loadSample(int sampleIndex);

    void write(int reg, int val);

    int write2(int state, int reg, int val);

    void flush();

    void channelOn(int reg, int volume);

    void channelOff(int reg);

    void resultCheck();

    void playSound(int offset);

    void playSoundAny(int offset) {
        playSoundData(loadData(offset), 0);
    }

    void playSoundData(byte *pData, int startingChannel = ADLIB_CHANNEL_MIDWAY);

    bool isSoundActive(byte *pData);

    void setFrequency(int channel, int freq);

    int getRandomNumber();

    byte *getDataPtr(int nearPtr);

    virtual int command0();
    int command1();
    int command2();
    int command3();
    int command4();
    int command5();
    int command6();
    int command7();
    int command8();

    int nullCommand() {
        return 0;
    }
public:
    AdlibChannel _channels[ADLIB_CHANNEL_COUNT];
    AdlibChannel *_activeChannelPtr;
    AdlibChannelData _channelData[11];
    Common::Array<AdlibSample> _samples;
    AdlibSample *_samplePtr;
    Common::Queue<RegisterValue> _queue;
    int _frameCounter;
    bool _isDisabled;
    int _noiseTicks1;       // remaining duration for noise voice 1 (byte_11F86)
    int _noiseTicks2;       // remaining duration for noise voice 2 (byte_11F87)
    int _activeChannelNumber;
    int _freqMask1;
    int _freqMask2;
    int _freqBase1;
    int _freqBase2;
    int _noiseChannel1, _noiseChannel2;
    int _noiseFreqStep1;    // per-tick frequency-sweep step for noise voice 1 (word_11F8A)
    int _noiseFreqStep2;    // per-tick frequency-sweep step for noise voice 2 (word_11F8C)
    int _savedNoiseTicks1;  // _noiseTicks1 saved across command6/7 (byte_194B0)
    int _savedNoiseTicks2;  // _noiseTicks2 saved across command6/7 (byte_194B1)
    int _pollResult;
    int _resultFlag;
    byte _nullData[2];
    int _ports[256];
    bool _stateFlag;
    int _activeChannelReg;
    int _outputReg;         // scratch OPL operator register offset used within loadSample()
    bool _amDep, _vibDep, _splitPoint;

public:
    static void validate();

public:
    ASound(Audio::Mixer *mixer, const Common::Path &filename, int dataOffset, int dataSize);

    ~ASound() override;

    int stop() override;

    int poll() override;

    void noise() override;

    int getFrameCounter() {
        return _frameCounter;
    }

    void setVolume(int volume) override;
};

// TODO: Merge RexASound into ASound
class RexASound : public ASound {
protected:
    void channelCommand(byte *&pSrc, bool &updateFlag) override;

public:
    RexASound(Audio::Mixer *mixer,  const Common::Path &filename, int dataOffset, int dataSize);
};

} // namespace RexNebular
} // namespace MADS

#endif