mame.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/>.
 *
 * LGPL licensed version of MAMEs fmopl (V0.37a modified) by
 * Tatsuyuki Satoh. Included from LGPL'ed AdPlug.
 *
 */


#ifndef AUDIO_SOFTSYNTH_OPL_MAME_H
#define AUDIO_SOFTSYNTH_OPL_MAME_H

#include "common/scummsys.h"
#include "common/random.h"

#include "audio/fmopl.h"

namespace OPL {
namespace MAME {

enum {
    FMOPL_ENV_BITS_HQ = 16,
    FMOPL_ENV_BITS_MQ = 8,
    FMOPL_ENV_BITS_LQ = 8,
    FMOPL_EG_ENT_HQ = 4096,
    FMOPL_EG_ENT_MQ = 1024,
    FMOPL_EG_ENT_LQ = 128
};


typedef void (*OPL_TIMERHANDLER)(int channel,double interval_Sec);
typedef void (*OPL_IRQHANDLER)(int param,int irq);
typedef void (*OPL_UPDATEHANDLER)(int param,int min_interval_us);

#define OPL_TYPE_WAVESEL   0x01  /* waveform select    */

/* Saving is necessary for member of the 'R' mark for suspend/resume */
/* ---------- OPL one of slot  ---------- */
typedef struct fm_opl_slot {
    int TL;     /* total level     :TL << 8             */
    int TLL;    /* adjusted now TL                      */
    uint8 KSR;  /* key scale rate  :(shift down bit)    */
    int *AR;    /* attack rate     :&AR_TABLE[AR<<2]    */
    int *DR;    /* decay rate      :&DR_TABLE[DR<<2]    */
    int SL;     /* sustain level   :SL_TABLE[SL]        */
    int *RR;    /* release rate    :&DR_TABLE[RR<<2]    */
    uint8 ksl;  /* keyscale level  :(shift down bits)   */
    uint8 ksr;  /* key scale rate  :kcode>>KSR          */
    uint mul;   /* multiple        :ML_TABLE[ML]        */
    uint Cnt;   /* frequency count                      */
    uint Incr;  /* frequency step                       */

    /* envelope generator state */
    uint8 eg_typ;/* envelope type flag                  */
    uint8 evm;  /* envelope phase                       */
    int evc;    /* envelope counter                     */
    int eve;    /* envelope counter end point           */
    int evs;    /* envelope counter step                */
    int evsa;   /* envelope step for AR :AR[ksr]        */
    int evsd;   /* envelope step for DR :DR[ksr]        */
    int evsr;   /* envelope step for RR :RR[ksr]        */

    /* LFO */
    uint8 ams;      /* ams flag                            */
    uint8 vib;      /* vibrate flag                        */
    /* wave selector */
    int **wavetable;
} OPL_SLOT;

/* ---------- OPL one of channel  ---------- */
typedef struct fm_opl_channel {
    OPL_SLOT SLOT[2];
    uint8 CON;          /* connection type                  */
    uint8 FB;           /* feed back       :(shift down bit)*/
    int *connect1;      /* slot1 output pointer             */
    int *connect2;      /* slot2 output pointer             */
    int op1_out[2];     /* slot1 output for selfeedback     */

    /* phase generator state */
    uint block_fnum;    /* block+fnum                       */
    uint8 kcode;        /* key code        : KeyScaleCode   */
    uint fc;            /* Freq. Increment base             */
    uint ksl_base;      /* KeyScaleLevel Base step          */
    uint8 keyon;        /* key on/off flag                  */
} OPL_CH;

/* OPL state */
typedef struct fm_opl_f {
    uint8 type;         /* chip type                         */
    int clock;          /* master clock  (Hz)                */
    int rate;           /* sampling rate (Hz)                */
    double freqbase;    /* frequency base                    */
    double TimerBase;   /* Timer base time (==sampling time) */
    uint8 address;      /* address register                  */
    uint8 status;       /* status flag                       */
    uint8 statusmask;   /* status mask                       */
    uint mode;          /* Reg.08 : CSM , notesel,etc.       */

    /* Timer */
    int T[2];           /* timer counter                     */
    uint8 st[2];        /* timer enable                      */

    /* FM channel slots */
    OPL_CH *P_CH;       /* pointer of CH                     */
    int max_ch;         /* maximum channel                   */

    /* Rhythm sention */
    uint8 rhythm;       /* Rhythm mode , key flag */

    /* time tables */
    int AR_TABLE[76];   /* atttack rate tables              */
    int DR_TABLE[76];   /* decay rate tables                */
    uint FN_TABLE[1024];/* fnumber -> increment counter     */

    /* LFO */
    int *ams_table;
    int *vib_table;
    int amsCnt;
    int amsIncr;
    int vibCnt;
    int vibIncr;

    /* wave selector enable flag */
    uint8 wavesel;

    /* external event callback handler */
    OPL_TIMERHANDLER  TimerHandler;     /* TIMER handler   */
    int TimerParam;                     /* TIMER parameter */
    OPL_IRQHANDLER    IRQHandler;       /* IRQ handler    */
    int IRQParam;                       /* IRQ parameter  */
    OPL_UPDATEHANDLER UpdateHandler;    /* stream update handler   */
    int UpdateParam;                    /* stream update parameter */

    Common::RandomSource *rnd;
} FM_OPL;

/* ---------- Generic interface section ---------- */
#define OPL_TYPE_YM3526 (0)
#define OPL_TYPE_YM3812 (OPL_TYPE_WAVESEL)

void OPLBuildTables(int ENV_BITS_PARAM, int EG_ENT_PARAM);

FM_OPL *OPLCreate(int type, int clock, int rate);
void OPLDestroy(FM_OPL *OPL);
void OPLSetTimerHandler(FM_OPL *OPL, OPL_TIMERHANDLER TimerHandler, int channelOffset);
void OPLSetIRQHandler(FM_OPL *OPL, OPL_IRQHANDLER IRQHandler, int param);
void OPLSetUpdateHandler(FM_OPL *OPL, OPL_UPDATEHANDLER UpdateHandler, int param);

void OPLResetChip(FM_OPL *OPL);
int OPLWrite(FM_OPL *OPL, int a, int v);
unsigned char OPLRead(FM_OPL *OPL, int a);
int OPLTimerOver(FM_OPL *OPL, int c);
void OPLWriteReg(FM_OPL *OPL, int r, int v);
void YM3812UpdateOne(FM_OPL *OPL, int16 *buffer, int length);

// Factory method
FM_OPL *makeAdLibOPL(int rate);

// OPL API implementation
class OPL : public ::OPL::OPL, public Audio::EmulatedChip {
private:
    FM_OPL *_opl;
public:
    OPL() : _opl(0) {}
    ~OPL();

    bool init();
    void reset();

    void write(int a, int v);

    void writeReg(int r, int v);

    bool isStereo() const { return false; }

protected:
    void generateSamples(int16 *buffer, int length);
};

} // End of namespace MAME
} // End of namespace OPL

#endif