c64.sfx.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_C64_SFX_H
#define FREESCAPE_DRILLER_C64_SFX_H

#include "audio/sid.h"

namespace Freescape {

// SID register offsets
enum SIDRegs {
    kSIDV1FreqLo  = 0x00,
    kSIDV1FreqHi  = 0x01,
    kSIDV1PwLo    = 0x02,
    kSIDV1PwHi    = 0x03,
    kSIDV1Ctrl    = 0x04,
    kSIDV1AD      = 0x05,
    kSIDV1SR      = 0x06,

    kSIDV2FreqLo  = 0x07,
    kSIDV2FreqHi  = 0x08,
    kSIDV2PwLo    = 0x09,
    kSIDV2PwHi    = 0x0A,
    kSIDV2Ctrl    = 0x0B,
    kSIDV2AD      = 0x0C,
    kSIDV2SR      = 0x0D,

    kSIDV3FreqLo  = 0x0E,
    kSIDV3FreqHi  = 0x0F,
    kSIDV3PwLo    = 0x10,
    kSIDV3PwHi    = 0x11,
    kSIDV3Ctrl    = 0x12,
    kSIDV3AD      = 0x13,
    kSIDV3SR      = 0x14,

    kSIDFilterLo  = 0x15,
    kSIDFilterHi  = 0x16,
    kSIDFilterCtrl = 0x17,
    kSIDVolume    = 0x18
};

class DrillerC64SFXPlayer {
public:
    DrillerC64SFXPlayer();
    ~DrillerC64SFXPlayer();

    void playSfx(int sfxIndex);
    void sfxTick();           // Called every frame (50Hz) from onTimer
    void stopAllSfx();

    bool isSfxActive() const;
    void initSID();
    void destroySID();

private:
    SID::SID *_sid;

    void sidWrite(int reg, uint8 data);

    // Voice 1 pitch slide state ($CC5B-$CC61)
    uint8 _v1Counter;      // 0xFF=inactive, 0=expired (marked 0xFF next tick)
    uint8 _v1FreqLo;
    uint8 _v1FreqHi;
    uint8 _v1DeltaLo;
    uint8 _v1DeltaHi;
    uint8 _v1TickCtr;
    uint8 _v1TickReload;

    // Voice 3 pitch slide state ($CC62-$CC66)
    uint8 _v3Counter;
    uint8 _v3FreqLo;
    uint8 _v3FreqHi;
    uint8 _v3DeltaLo;
    uint8 _v3DeltaHi;

    // Noise burst timer ($CC67-$CC6A)
    uint8 _noiseTimer;
    uint8 _noiseCounter;
    uint8 _noiseReload;
    uint8 _noiseDec;

    // Phase state machine for multi-step SFX (#6, #14, #15)
    uint8 _sfxPhase;        // 0=inactive
    uint8 _sfxPhaseTimer;   // frames until next phase transition
    uint8 _sfxActiveIndex;  // which SFX owns the phase state

    // Tick handlers
    void tickVoice1Slide();
    void tickVoice3Slide();
    void tickNoiseBurst();
    void tickPhase();

    // Helper to silence all voices
    void silenceAllVoices();

    // Noise burst subroutine ($C818)
    void noiseBurst(uint8 param);

    // Individual SFX routines
    void sfx2();   // Dual-voice noise sweep down
    void sfx3();   // Noise pitch slide
    void sfx4();   // Pulse slide down
    void sfx5();   // Pulse slide up
    void sfx6();   // Triangle blip
    void sfx7();   // Dual noise burst
    void sfx8();   // Triangle slide up
    void sfx9();   // Dual slide (V1+V3) noise
    void sfx10();  // Programmed noise bursts
    void sfx11();  // Triangle slide down (fast)
    void sfx14();  // 3-step chord (V1+V2)
    void sfx15();  // Two-phase pulse effect
    void sfx16();  // Filtered effect (V1+V3)
    void sfx17();  // Freq echo (V1->V3)
    void sfx18();  // Dual noise with modulation

    void onTimer();
};

} // namespace Freescape

#endif // FREESCAPE_DRILLER_C64_SFX_H