pcspk.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_IMUSE_PCSPK_H
#define SCUMM_IMUSE_PCSPK_H

#include "audio/softsynth/emumidi.h"
#include "audio/softsynth/pcspk.h"

namespace Scumm {

class IMuseDriver_PCSpk : public MidiDriver_Emulated {
public:
    IMuseDriver_PCSpk(Audio::Mixer *mixer);
    ~IMuseDriver_PCSpk() override;

    int open() override;
    void close() override;

    void send(uint32 d) override;

    MidiChannel *allocateChannel() override;
    MidiChannel *getPercussionChannel() override { return nullptr; }

    bool isStereo() const override { return _pcSpk.isStereo(); }
    int getRate() const override { return _pcSpk.getRate(); }
protected:
    void generateSamples(int16 *buf, int len) override;
    void onTimer() override;

private:
    Audio::PCSpeaker _pcSpk;
    int _effectTimer;
    uint8 _randBase;

    void updateNote();
    void output(uint16 out);

    static uint8 getEffectModifier(uint16 level);
    int16 getEffectModLevel(int16 level, int8 mod);
    int16 getRandScale(int16 input);

    struct EffectEnvelope {
        uint8 state;
        int16 currentLevel;
        int16 duration;
        int16 maxLevel;
        int16 startLevel;
        uint8 loop;
        uint8 stateTargetLevels[4];
        uint8 stateModWheelLevels[4];
        uint8 modWheelSensitivity;
        uint8 modWheelState;
        uint8 modWheelLast;
        int16 stateNumSteps;
        int16 stateStepCounter;
        int16 changePerStep;
        int8 dir;
        int16 changePerStepRem;
        int16 changeCountRem;
    };

    struct EffectDefinition {
        int16 phase;
        uint8 type;
        uint8 useModWheel;
        EffectEnvelope *envelope;
    };

    struct OutputChannel {
        uint8 active;
        uint8 note;
        uint8 sustainNoteOff;
        uint8 length;
        const uint8 *instrument;
        uint8 unkA;
        uint8 unkB;
        uint8 unkC;
        int16 unkE;
        EffectEnvelope effectEnvelopeA;
        EffectDefinition effectDefA;
        EffectEnvelope effectEnvelopeB;
        EffectDefinition effectDefB;
        int16 unk60;
    };

    class MidiChannel_PcSpk: public MidiChannel {
    public:
        MidiChannel_PcSpk(IMuseDriver_PCSpk *owner, byte number);
        MidiDriver *device() override { return _owner; }
        byte getNumber() override { return _number; }
        void release() override;

        void send(uint32 b) override;
        void noteOff(byte note) override;
        void noteOn(byte note, byte velocity) override;
        void programChange(byte program) override;
        void pitchBend(int16 bend) override;
        void controlChange(byte control, byte value) override;
        void pitchBendFactor(byte value) override;
        void transpose(int8 value) override;
        void detune(int16 value) override;
        void priority(byte value) override;
        void sysEx_customInstrument(uint32 type, const byte *instr, uint32 dataSize) override;

        bool allocate();

        bool _allocated;
        OutputChannel _out;
        uint8 _instrument[23];
        uint8 _priority;
        uint8 _tl;
        uint8 _modWheel;
        int16 _pitchBend;

    private:
        IMuseDriver_PCSpk *_owner;
        const byte _number;
        //uint8 _programNr;
        uint8 _sustain;
        uint8 _pitchBendFactor;
        int16 _pitchBendTmp;
        int8 _transpose;
        int8 _detune;
    };

    void setupEffects(MidiChannel_PcSpk &chan, EffectEnvelope &env, EffectDefinition &def, byte flags, const byte *data);
    void startEffect(EffectEnvelope &env, const byte *data);
    void initNextEnvelopeState(EffectEnvelope &env);
    void updateEffectGenerator(MidiChannel_PcSpk &chan, EffectEnvelope &env, EffectDefinition &def);
    uint8 advanceEffectEnvelope(EffectEnvelope &env, EffectDefinition &def);

    MidiChannel_PcSpk *_channels[6];
    MidiChannel_PcSpk *_activeChannel;

    MidiChannel_PcSpk *_lastActiveChannel;
    uint16 _lastActiveOut;

    static const byte _outInstrumentData[1024];
    static const byte _outputTable1[];
    static const byte _outputTable2[];
    static const uint16 _effectEnvStepTable[];
    static const uint16 _frequencyTable[];
};

} // End of namespace Scumm

#endif