player_ad.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 SCUMM_PLAYERS_PLAYER_AD_H
#define SCUMM_PLAYERS_PLAYER_AD_H

#include "scumm/music.h"

#include "common/mutex.h"
#include "common/serializer.h"

namespace OPL {
class OPL;
}

namespace Scumm {

class ScummEngine;

class Player_AD : public MusicEngine {
public:
    Player_AD(ScummEngine *scumm, Common::Mutex &mutex);
    ~Player_AD() override;

    // MusicEngine API
    void setMusicVolume(int vol) override;
    void startSound(int sound) override;
    void stopSound(int sound) override;
    void stopAllSounds() override;
    int  getMusicTimer() override;
    int  getSoundStatus(int sound) const override;

    void saveLoadWithSerializer(Common::Serializer &ser) override;

    // Timer callback
    void onTimer();

private:
    ScummEngine *const _vm;
    Common::Mutex &_mutex;

    void setupVolume();
    int _musicVolume;
    int _sfxVolume;

    OPL::OPL *_opl2;

    int _musicResource;
    int32 _engineMusicTimer;

    struct SfxSlot;

    struct HardwareChannel {
        bool allocated;
        int priority;
        SfxSlot *sfxOwner;
    } _hwChannels[9];
    int _numHWChannels;
    static const int _operatorOffsetToChannel[22];

    int allocateHWChannel(int priority, SfxSlot *owner = nullptr);
    void freeHWChannel(int channel);
    void limitHWChannels(int newCount);

    // AdLib register utilities
    uint8 _registerBackUpTable[256];
    void writeReg(int r, int v);
    uint8 readReg(int r) const;

    // Instrument setup
    void setupChannel(const uint channel, const byte *instrOffset);
    void setupOperator(const uint opr, const byte *&instrOffset);
    static const int _operatorOffsetTable[18];

    // Music handling
    void startMusic();
    void stopMusic();
    void updateMusic();
    bool parseCommand();
    uint parseVLQ();
    void noteOff(uint channel);
    void setupFrequency(uint channel, int8 frequency);
    void setupRhythm(uint rhythmInstr, uint instrOffset);

    const byte *_musicData;
    uint _timerLimit;
    uint _musicTicks;
    uint32 _musicTimer;
    uint32 _internalMusicTimer;
    bool _loopFlag;
    uint _musicLoopStart;
    uint _instrumentOffset[16];

    struct VoiceChannel {
        uint lastEvent;
        uint frequency;
        uint b0Reg;
    } _voiceChannels[9];
    void freeVoiceChannel(uint channel);

    void musicSeekTo(const uint position);
    bool _isSeeking;

    uint _mdvdrState;

    uint32 _curOffset;
    uint32 _nextEventTimer;

    static const uint _noteFrequencies[12];
    static const uint _mdvdrTable[6];
    static const uint _rhythmOperatorTable[6];
    static const uint _rhythmChannelTable[6];

    // SFX handling
    enum {
        kNoteStatePreInit = -1,
        kNoteStateAttack = 0,
        kNoteStateDecay = 1,
        kNoteStateSustain = 2,
        kNoteStateRelease = 3,
        kNoteStateOff = 4
    };

    struct Note {
        int state;
        int playTime;
        int sustainTimer;
        int instrumentValue;
        int bias;
        int preIncrease;
        int adjust;

        struct Envelope {
            int stepIncrease;
            int step;
            int stepCounter;
            int timer;
        } envelope;
    };

    enum {
        kChannelStateOff = 0,
        kChannelStateParse = 1,
        kChannelStatePlay = 2
    };

    struct Channel {
        int state;
        const byte *currentOffset;
        const byte *startOffset;
        uint8 instrumentData[7];

        Note notes[2];

        int hardwareChannel;
    };

    struct SfxSlot {
        int resource;
        int priority;

        Channel channels[3];
    } _sfx[3];

    SfxSlot *allocateSfxSlot(int priority);
    bool startSfx(SfxSlot *sfx, const byte *resource);
    void stopSfx(SfxSlot *sfx);

    void updateSfx();
    void clearChannel(const Channel &channel);
    void updateChannel(Channel *channel);
    void parseSlot(Channel *channel);
    void updateSlot(Channel *channel);
    void parseNote(Note *note, const Channel &channel, const byte *offset);
    bool processNote(Note *note, const Channel &channel, const byte *offset);
    void noteOffOn(int channel);
    void writeRegisterSpecial(int channel, uint8 value, int offset);
    uint8 readRegisterSpecial(int channel, uint8 defaultValue, int offset);
    void setupNoteEnvelopeState(Note *note, int steps, int adjust);
    bool processNoteEnvelope(Note *note);

    int _sfxTimer;

    uint8 _rndSeed;
    uint8 getRnd();

    static const uint _noteBiasTable[7];
    static const uint _numStepsTable[16];
    static const uint _noteAdjustScaleTable[7];
    static const uint _noteAdjustTable[16];
    static const bool _useOperatorTable[7];
    static const uint _channelOffsetTable[11];
    static const uint _channelOperatorOffsetTable[7];
    static const uint _baseRegisterTable[7];
    static const uint _registerMaskTable[7];
    static const uint _registerShiftTable[7];
};

} // End of namespace Scumm

#endif