opl.music.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 FREESCAPE_DRILLER_OPL_MUSIC_H
#define FREESCAPE_DRILLER_OPL_MUSIC_H
 
#include "audio/fmopl.h"
#include "freescape/music.h"
 
namespace Freescape {
 
class DrillerOPLMusicPlayer : public MusicPlayer {
public:
    DrillerOPLMusicPlayer(int tuneIndex = 1);
    ~DrillerOPLMusicPlayer() override;
 
    void startMusic() override;
    void stopMusic() override;
    bool isPlaying() const override;
 
private:
    enum {
        kChannelCount = 3,
        kMaxNote = 94
    };
 
    enum ContinuousEffectEntry {
        kVoiceDone,
        kFullEffectPath,
        kPortamentoOnlyPath
    };
 
    struct VoiceState {
        const uint8_t *trackDataPtr;
        uint8_t trackIndex;
        const uint8_t *patternDataPtr;
        uint8_t patternIndex;
        uint8_t instrumentIndex;
        int8_t delayCounter;
        uint8_t noteDuration;
        uint8_t gateMask;
        uint8_t currentNote;
        uint8_t currentNoteSlideTarget;
        uint8_t currentControl;
        uint8_t whatever0;
        uint8_t whatever1;
        uint8_t whatever2;
        uint8_t whatever3;
        uint8_t whatever4;
        uint8_t whatever2_vibDirToggle;
        uint16_t portaStepRaw;
        uint8_t something_else[3];
        uint8_t ctrl0;
        uint8_t arpTableIndex;
        uint8_t arpSpeedHiNibble;
        uint16_t stuff_freq_porta_vib;
        uint16_t stuff_freq_base;
        uint8_t stuff_arp_counter;
        uint8_t things_vib_state;
        uint16_t things_vib_depth;
        uint8_t things_vib_delay_reload;
        uint8_t things_vib_delay_ctr;
        uint8_t glideDownTimer;
        uint16_t baseSIDFrequency;
        uint16_t baseFrequencyFnum;
        uint8_t baseFrequencyBlock;
        uint16_t frequencyFnum;
        uint8_t frequencyBlock;
        bool keyOn;
        bool gateReleased;
 
        void reset();
    };
 
    OPL::OPL *_opl;
    bool _musicActive;
    uint8_t _targetTuneIndex;
    uint8_t _globalTempo;
    int8_t _globalTempoCounter;
    uint32 _tick;
    VoiceState _voiceState[kChannelCount];
 
    void onTimer();
    void setupTune(int tuneIndex);
    void resetVoices();
    void silenceAll();
    void playVoice(int channel);
    void applyNote(int channel, VoiceState &voice, const uint8_t *instA0, const uint8_t *instA1);
    ContinuousEffectEntry postNoteEffectSetup(VoiceState &voice, const uint8_t *instA0, const uint8_t *instA1);
    void applyContinuousEffects(int channel, VoiceState &voice, const uint8_t *instA0, const uint8_t *instA1, bool startAtPortamento);
    void applyHardRestart(int channel, VoiceState &voice, const uint8_t *instA1);
    void setOPLInstrument(int channel, VoiceState &voice);
    void applyPulseWidth(int channel, const VoiceState &voice);
    void noteOn(int channel, VoiceState &voice, uint8_t note);
    void noteOff(int channel);
    void setFrequency(int channel, VoiceState &voice, uint16 fnum, byte block);
    void writeFrequency(int channel, const VoiceState &voice, uint16 fnum, byte block);
    void writeNoteFrequency(int channel, VoiceState &voice, uint8_t note);
    void writeSIDFrequency(int channel, VoiceState &voice, uint16 sidFrequency);
    void noteToFnumBlock(int note, uint16 &fnum, byte &block) const;
};
 
} // namespace Freescape
 
#endif