player_sid.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_SID_H
#define SCUMM_PLAYERS_PLAYER_SID_H

#include "common/mutex.h"
#include "common/scummsys.h"
#include "scumm/music.h"
#include "audio/audiostream.h"
#include "audio/mixer.h"
#include "audio/softsynth/sid.h"

namespace Scumm {

// the "channel" parameters seem to be in fact SID register
// offsets. Should be replaced.
enum sid_reg_t {
    FREQ_VOICE1,
    FREQ_VOICE2,
    FREQ_VOICE3,
    FREQ_FILTER,
    PULSE_VOICE1,
    PULSE_VOICE2,
    PULSE_VOICE3
};

enum VideoStandard {
    PAL,
    NTSC
};

class ScummEngine;

class Player_SID : public Audio::AudioStream, public MusicEngine {
public:
    Player_SID(ScummEngine *scumm, Audio::Mixer *mixer);
    ~Player_SID() override;

    void setMusicVolume(int vol) override { _maxvol = vol; }
    void startSound(int sound) override;
    void stopSound(int sound) override;
    void stopAllSounds() override;
    int  getSoundStatus(int sound) const override;
    int  getMusicTimer() override;

    // AudioStream API
    int readBuffer(int16 *buffer, const int numSamples) override;
    bool isStereo() const override { return false; }
    bool endOfData() const override { return false; }
    int getRate() const override { return _sampleRate; }

private:
    Resid::SID *_sid;
    void SID_Write(int reg, uint8 data);
    void initSID();
    uint8 *getResource(int resID);

    // number of cpu cycles until next frame update
    Resid::cycle_count _cpuCyclesLeft;

    ScummEngine *_vm;
    Audio::Mixer *_mixer;
    Audio::SoundHandle _soundHandle;
    int _sampleRate;
    int _maxvol;
    Common::Mutex _mutex;

    VideoStandard _videoSystem;

    int _music_timer;
    uint8* _music;

private:
    void initMusic(int songResIndex); // $7de6
    int initSound(int soundResID); // $4D0A
    void stopSound_intern(int soundResID); // $5093
    void stopMusic_intern(); // $4CAA

    void resetSID(); // $48D8
    void update(); // $481B
    void handleMusicBuffer();
    int setupSongFileData(); // $36cb
    void func_3674(int channel); // $3674
    void resetPlayerState(); // $48f7
    void processSongData(int channel); // $4939
    void readSetSIDFilterAndProps(int *offset, uint8* dataPtr);  // $49e7
    void saveSongPos(int y, int channel);
    void updateFreq(int channel);
    void resetFreqDelta(int channel);
    void readSongChunk(int channel); // $4a6b
    void setSIDFreqAS(int channel); // $4be6
    void setSIDWaveCtrlReg(int channel); // $4C0D
    int setupSongPtr(int channel); // $4C1C
    void unlockResource(int chanResIndex); // $4CDA
    void countFreeChannels(); // $4f26
    void func_4F45(int channel); // $4F45
    void safeUnlockResource(int resIndex); // $4FEA
    void releaseResource(int resIndex); // $5031
    void releaseResChannels(int resIndex); // $5070
    void releaseResourceUnk(int resIndex); // $50A4
    void releaseChannel(int channel);
    void clearSIDWaveform(int channel);
    void stopChannel(int channel);
    void swapVars(int channel, int swapIndex); // $51a5
    void resetSwapVars(); // $52d0
    void prepareSwapVars(int channel); // $52E5
    void useSwapVars(int channel); // $5342
    void lockResource(int resIndex); // $4ff4
    void reserveChannel(int channel, uint8 prioValue, int chanResIndex); // $4ffe
    void unlockCodeLocation(); // $513e
    void lockCodeLocation(); // $514f
    void func_7eae(int channel, uint8* songFileDataPtr); // $7eae
    void func_819b(int channel); // $819b
    void buildStepTbl(int step); // $82B4
    int reserveSoundFilter(uint8 value, uint8 chanResIndex); // $4ED0
    int reserveSoundVoice(uint8 value, uint8 chanResIndex); // $4EB8
    void findLessPrioChannels(uint8 soundPrio); // $4ED8
    void releaseResourceBySound(int resID); // $5088
    void readVec6Data(int x, int *offset, uint8 *songFilePtr, int chanResID); // $4E99

    void unused1(); // $50AF

    uint8 chanBuffer[3][45];

    int resID_song;

    // statusBits1A/1B are always equal
    uint8 statusBits1A;
    uint8 statusBits1B;

    uint8 busyChannelBits;

    uint8 SIDReg23;
    uint8 SIDReg23Stuff;
    uint8 SIDReg24;

    uint8* chanFileData[3];
    uint16 chanDataOffset[3];
    uint8* songPosPtr[7];

    // 0..2: freq value voice1/2/3
    // 3:    filter freq
    // 4..6: pulse width
    uint16 freqReg[7];

    // start offset[i] for songFileOrChanBufData to obtain songPosPtr[i]
    //  vec6[0..2] = 0x0008;
    //  vec6[4..6] = 0x0019;
    uint16 vec6[7];

    // current offset[i] for songFileOrChanBufData to obtain songPosPtr[i] (starts with vec6[i], increased later)
    uint16 songFileOrChanBufOffset[7];

    uint16 freqDelta[7];
    int freqDeltaCounter[7];
    uint8* swapSongPosPtr[3];
    uint8* swapVec5[3];
    uint16 swapVec8[3];
    uint16 swapVec10[3];
    uint16 swapFreqReg[3];
    int swapVec11[3];

    // never read
    //uint8* vec5[7];
    // never read
    //uint8 vec19[7];
    // never read (needed by scumm engine?)
    //bool curChannelActive;

    uint8* vec20[7];

    uint8* swapVec20[3];

    // resource status (never read)
    // bit7: some flag
    // bit6..0: counter (use-count?), maybe just bit0 as flag (used/unused?)
    uint8 resStatus[70];

    uint8* songFileOrChanBufData;
    uint8* actSongFileData;

    uint16 stepTbl[33];

    bool initializing;
    bool _soundInQueue;
    bool isVoiceChannel;

    bool isMusicPlaying;
    bool swapVarLoaded;
    bool bgSoundActive;
    bool filterUsed;

    uint8 bgSoundResID;
    uint8 freeChannelCount;

    // seems to be used for managing the three voices
    // bit[0..2]: 0 -> unused, 1 -> already in use
    uint8 usedChannelBits;
    uint8 attackReg[3];
    uint8 sustainReg[3];

    // -1/0/1
    int var481A;

    // bit-array: 00000cba
    // a/b/c: channel1/2/3
    uint8 songChannelBits;

    bool pulseWidthSwapped;
    bool swapPrepared;

    // never read
    //uint8 var5163;

    bool filterSwapped;
    uint8 SIDReg24_HiNibble;
    bool keepSwapVars;

    uint8 phaseBit[3];
    bool releasePhase[3];

    // values: a resID or -1
    // resIDs: 3, 4, 5 or song-number
    int _soundQueue[7];

    // values: a resID or 0
    // resIDs: 3, 4, 5 or song-number
    int channelMap[7];

    uint8 songPosUpdateCounter[7];

    // priortity of channel contents
    // MM:  1: lowest .. 120: highest (1,2,A,64,6E,73,78)
    // Zak: -???: lowest .. 120: highest (5,32,64,65,66,6E,78, A5,A6,AF,D7)
    uint8 chanPrio[7];

    // only [0..2] used?
    uint8 waveCtrlReg[7];

    uint8 swapAttack[2];
    uint8 swapSustain[2];
    uint8 swapSongPrio[3];
    int swapVec479C[3];
    uint8 swapVec19[3];
    uint8 swapSongPosUpdateCounter[3];
    uint8 swapWaveCtrlReg[3];

    bool actFilterHasLowerPrio;
    uint8 chansWithLowerPrioCount;
    uint8 minChanPrio;
    uint8 minChanPrioIndex;
};

} // End of namespace Scumm

#endif