fmopl.cpp

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/* 
 * Copyright (C) 1999/2000 Tatsuyuki Satoh
 * Copyright (C) 2001/2002 The ScummVM project
 * Copyright (C) 2002 The Exult Team
 * Copyright (C) 2003 The Pentagram Team
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * LGPL licensed version of MAMEs fmopl (V0.37a modified) by
 * Tatsuyuki Satoh. Included from LGPL'ed AdPlug.
 */

#include "pent_include.h"

#ifdef USE_FMOPL_MIDI

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cstdarg>
#include <cmath>
#include <iostream>
#include "fmopl.h"

namespace FMOpl_Pentagram {

#ifndef UNDER_CE
using std::malloc;
using std::free;
#endif

#ifndef PI
#define PI 3.14159265358979323846
#endif

/* -------------------- preliminary define section --------------------- */
/* attack/decay rate time rate */
#define OPL_ARRATE     141280  /* RATE 4 =  2826.24ms @ 3.6MHz */
#define OPL_DRRATE    1956000  /* RATE 4 = 39280.64ms @ 3.6MHz */

#define FREQ_BITS 24                    /* frequency turn          */

/* counter bits = 20 , octerve 7 */
#define FREQ_RATE   (1<<(FREQ_BITS-20))
#define TL_BITS    (FREQ_BITS+2)

/* final output shift , limit minimum and maximum */
#define OPL_OUTSB   (TL_BITS+3-16)              /* OPL output final shift 16bit */
#define OPL_MAXOUT (0x7fff<<OPL_OUTSB)
#define OPL_MINOUT (-0x8000<<OPL_OUTSB)

/* -------------------- quality selection --------------------- */

/* sinwave entries */
/* used static memory = SIN_ENT * 4 (byte) */
#define SIN_ENT 2048

/* output level entries (envelope,sinwave) */
/* envelope counter lower bits */
#define ENV_BITS 16
/* envelope output entries */
#define EG_ENT   4096
/* used dynamic memory = EG_ENT*4*4(byte)or EG_ENT*6*4(byte) */
/* used static  memory = EG_ENT*4 (byte)                     */

#define EG_OFF   ((2*EG_ENT)<<ENV_BITS)  /* OFF          */
#define EG_DED   EG_OFF
#define EG_DST   (EG_ENT<<ENV_BITS)      /* DECAY  START */
#define EG_AED   EG_DST
#define EG_AST   0                       /* ATTACK START */

#define EG_STEP (96.0/EG_ENT) /* OPL is 0.1875 dB step  */

/* LFO table entries */
#define VIB_ENT 512
#define VIB_SHIFT (32-9)
#define AMS_ENT 512
#define AMS_SHIFT (32-9)

#define VIB_RATE 256

/* -------------------- local defines , macros --------------------- */

/* register number to channel number , slot offset */
#define SLOT1 0
#define SLOT2 1

/* envelope phase */
#define ENV_MOD_RR  0x00
#define ENV_MOD_DR  0x01
#define ENV_MOD_AR  0x02

/* -------------------- tables --------------------- */
static const int slot_array[32]=
{
         0, 2, 4, 1, 3, 5,-1,-1,
         6, 8,10, 7, 9,11,-1,-1,
        12,14,16,13,15,17,-1,-1,
        -1,-1,-1,-1,-1,-1,-1,-1
};

#define SC(mydb) (static_cast<uint32>(mydb / (EG_STEP/2)))

static const uint32 KSL_TABLE[8 * 16] = {
        /* OCT 0 */
        SC(0.000), SC(0.000), SC(0.000), SC(0.000),
        SC(0.000), SC(0.000), SC(0.000), SC(0.000),
        SC(0.000), SC(0.000), SC(0.000), SC(0.000),
        SC(0.000), SC(0.000), SC(0.000), SC(0.000),
        /* OCT 1 */
        SC(0.000), SC(0.000), SC(0.000), SC(0.000),
        SC(0.000), SC(0.000), SC(0.000), SC(0.000),
        SC(0.000), SC(0.750), SC(1.125), SC(1.500),
        SC(1.875), SC(2.250), SC(2.625), SC(3.000),
        /* OCT 2 */
        SC(0.000), SC(0.000), SC(0.000), SC(0.000),
        SC(0.000), SC(1.125), SC(1.875), SC(2.625),
        SC(3.000), SC(3.750), SC(4.125), SC(4.500),
        SC(4.875), SC(5.250), SC(5.625), SC(6.000),
        /* OCT 3 */
        SC(0.000), SC(0.000), SC(0.000), SC(1.875),
        SC(3.000), SC(4.125), SC(4.875), SC(5.625),
        SC(6.000), SC(6.750), SC(7.125), SC(7.500),
        SC(7.875), SC(8.250), SC(8.625), SC(9.000),
        /* OCT 4 */
        SC(0.000), SC(0.000), SC(3.000), SC(4.875),
        SC(6.000), SC(7.125), SC(7.875), SC(8.625),
        SC(9.000), SC(9.750), SC(10.125), SC(10.500),
        SC(10.875), SC(11.250), SC(11.625), SC(12.000),
        /* OCT 5 */
        SC(0.000), SC(3.000), SC(6.000), SC(7.875),
        SC(9.000), SC(10.125), SC(10.875), SC(11.625),
        SC(12.000), SC(12.750), SC(13.125), SC(13.500),
        SC(13.875), SC(14.250), SC(14.625), SC(15.000),
        /* OCT 6 */
        SC(0.000), SC(6.000), SC(9.000), SC(10.875),
        SC(12.000), SC(13.125), SC(13.875), SC(14.625),
        SC(15.000), SC(15.750), SC(16.125), SC(16.500),
        SC(16.875), SC(17.250), SC(17.625), SC(18.000),
        /* OCT 7 */
        SC(0.000), SC(9.000), SC(12.000), SC(13.875),
        SC(15.000), SC(16.125), SC(16.875), SC(17.625),
        SC(18.000), SC(18.750), SC(19.125), SC(19.500),
        SC(19.875), SC(20.250), SC(20.625), SC(21.000)
};
#undef SC


/* sustain lebel table (3db per step) */
/* 0 - 15: 0, 3, 6, 9,12,15,18,21,24,27,30,33,36,39,42,93 (dB)*/
#define SC(db) static_cast<int>(db*((3/EG_STEP)*(1<<ENV_BITS)))+EG_DST
static const int SL_TABLE[16]={
 SC( 0),SC( 1),SC( 2),SC(3 ),SC(4 ),SC(5 ),SC(6 ),SC( 7),
 SC( 8),SC( 9),SC(10),SC(11),SC(12),SC(13),SC(14),SC(31)
};
#undef SC

#define TL_MAX (EG_ENT*2) /* limit(tl + ksr + envelope) + sinwave */
/* TotalLevel : 48 24 12  6  3 1.5 0.75 (dB) */
/* TL_TABLE[ 0      to TL_MAX          ] : plus  section */
/* TL_TABLE[ TL_MAX to TL_MAX+TL_MAX-1 ] : minus section */
static int *TL_TABLE;

/* pointers to TL_TABLE with sinwave output offset */
static int **SIN_TABLE;

/* LFO table */
static int *AMS_TABLE;
static int *VIB_TABLE;

/* envelope output curve table */
/* attack + decay + OFF */
static int ENV_CURVE[2*EG_ENT+1];

/* multiple table */
#define ML(a) static_cast<int>(a*2)
static const uint32 MUL_TABLE[16]= {
/* 1/2, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15 */
   ML(0.50), ML(1.00), ML(2.00),  ML(3.00), ML(4.00), ML(5.00), ML(6.00), ML(7.00),
   ML(8.00), ML(9.00), ML(10.00), ML(10.00),ML(12.00),ML(12.00),ML(15.00),ML(15.00)
};
#undef ML

/* dummy attack / decay rate ( when rate == 0 ) */
static int RATE_0[16]=
{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

/* -------------------- static state --------------------- */

/* lock level of common table */
static int num_lock = 0;

/* work table */
static void *cur_chip = NULL;   /* current chip point */
/* currenct chip state */
/* static OPLSAMPLE  *bufL,*bufR; */
static OPL_CH *S_CH;
static OPL_CH *E_CH;
OPL_SLOT *SLOT7_1,*SLOT7_2,*SLOT8_1,*SLOT8_2;

static int outd[1];
static int ams;
static int vib;
int  *ams_table;
int  *vib_table;
static int amsIncr;
static int vibIncr;
static int feedback2;           /* connect for SLOT 2 */

/* --------------------- subroutines  --------------------- */

inline int Limit( int val, int max, int min ) {
        if ( val > max )
                val = max;
        else if ( val < min )
                val = min;

        return val;
}

/* status set and IRQ handling */
inline void OPL_STATUS_SET(FM_OPL *OPL,int flag)
{
        /* set status flag */
        OPL->status |= flag;
        if(!(OPL->status & 0x80))
        {
                if(OPL->status & OPL->statusmask)
                {       /* IRQ on */
                        OPL->status |= 0x80;
                        /* callback user interrupt handler (IRQ is OFF to ON) */
                        if(OPL->IRQHandler) (OPL->IRQHandler)(OPL->IRQParam,1);
                }
        }
}

/* status reset and IRQ handling */
inline void OPL_STATUS_RESET(FM_OPL *OPL,int flag)
{
        /* reset status flag */
        OPL->status &=~flag;
        if((OPL->status & 0x80))
        {
                if (!(OPL->status & OPL->statusmask) )
                {
                        OPL->status &= 0x7f;
                        /* callback user interrupt handler (IRQ is ON to OFF) */
                        if(OPL->IRQHandler) (OPL->IRQHandler)(OPL->IRQParam,0);
                }
        }
}

/* IRQ mask set */
inline void OPL_STATUSMASK_SET(FM_OPL *OPL,int flag)
{
        OPL->statusmask = flag;
        /* IRQ handling check */
        OPL_STATUS_SET(OPL,0);
        OPL_STATUS_RESET(OPL,0);
}

/* ----- key on  ----- */
inline void OPL_KEYON(OPL_SLOT *SLOT)
{
        /* sin wave restart */
        SLOT->Cnt = 0;
        /* set attack */
        SLOT->evm = ENV_MOD_AR;
        SLOT->evs = SLOT->evsa;
        SLOT->evc = EG_AST;
        SLOT->eve = EG_AED;
}
/* ----- key off ----- */
inline void OPL_KEYOFF(OPL_SLOT *SLOT)
{
        if( SLOT->evm > ENV_MOD_RR)
        {
                /* set envelope counter from envleope output */
                SLOT->evm = ENV_MOD_RR;
                if( !(SLOT->evc&EG_DST) )
                        //SLOT->evc = (ENV_CURVE[SLOT->evc>>ENV_BITS]<<ENV_BITS) + EG_DST;
                        SLOT->evc = EG_DST;
                SLOT->eve = EG_DED;
                SLOT->evs = SLOT->evsr;
        }
}

/* ---------- calcrate Envelope Generator & Phase Generator ---------- */
/* return : envelope output */
inline uint32 OPL_CALC_SLOT( OPL_SLOT *SLOT )
{
        /* calcrate envelope generator */
        if( (SLOT->evc+=SLOT->evs) >= SLOT->eve )
        {
                switch( SLOT->evm ){
                case ENV_MOD_AR: /* ATTACK -> DECAY1 */
                        /* next DR */
                        SLOT->evm = ENV_MOD_DR;
                        SLOT->evc = EG_DST;
                        SLOT->eve = SLOT->SL;
                        SLOT->evs = SLOT->evsd;
                        break;
                case ENV_MOD_DR: /* DECAY -> SL or RR */
                        SLOT->evc = SLOT->SL;
                        SLOT->eve = EG_DED;
                        if(SLOT->eg_typ)
                        {
                                SLOT->evs = 0;
                        }
                        else
                        {
                                SLOT->evm = ENV_MOD_RR;
                                SLOT->evs = SLOT->evsr;
                        }
                        break;
                case ENV_MOD_RR: /* RR -> OFF */
                        SLOT->evc = EG_OFF;
                        SLOT->eve = EG_OFF+1;
                        SLOT->evs = 0;
                        break;
                }
        }
        /* calcrate envelope */
        return SLOT->TLL+ENV_CURVE[SLOT->evc>>ENV_BITS]+(SLOT->ams ? ams : 0);
}

/* set algorythm connection */
static void set_algorythm( OPL_CH *CH)
{
        int *carrier = &outd[0];
        CH->connect1 = CH->CON ? carrier : &feedback2;
        CH->connect2 = carrier;
}

/* ---------- frequency counter for operater update ---------- */
inline void CALC_FCSLOT(OPL_CH *CH,OPL_SLOT *SLOT)
{
        int ksr;

        /* frequency step counter */
        SLOT->Incr = CH->fc * SLOT->mul;
        ksr = CH->kcode >> SLOT->KSR;

        if( SLOT->ksr != ksr )
        {
                SLOT->ksr = ksr;
                /* attack , decay rate recalcration */
                SLOT->evsa = SLOT->AR[ksr];
                SLOT->evsd = SLOT->DR[ksr];
                SLOT->evsr = SLOT->RR[ksr];
        }
        SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
}

/* set multi,am,vib,EG-TYP,KSR,mul */
inline void set_mul(FM_OPL *OPL,int slot,int v)
{
        OPL_CH   *CH   = &OPL->P_CH[slot/2];
        OPL_SLOT *SLOT = &CH->SLOT[slot&1];

        SLOT->mul    = MUL_TABLE[v&0x0f];
        SLOT->KSR    = (v&0x10) ? 0 : 2;
        SLOT->eg_typ = (v&0x20)>>5;
        SLOT->vib    = (v&0x40);
        SLOT->ams    = (v&0x80);
        CALC_FCSLOT(CH,SLOT);
}

/* set ksl & tl */
inline void set_ksl_tl(FM_OPL *OPL,int slot,int v)
{
        OPL_CH   *CH   = &OPL->P_CH[slot/2];
        OPL_SLOT *SLOT = &CH->SLOT[slot&1];
        int ksl = v>>6; /* 0 / 1.5 / 3 / 6 db/OCT */

        SLOT->ksl = ksl ? 3-ksl : 31;
        SLOT->TL  = (int)((v&0x3f)*(0.75/EG_STEP)); /* 0.75db step */

        if( !(OPL->mode&0x80) )
        {       /* not CSM latch total level */
                SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
        }
}

/* set attack rate & decay rate  */
inline void set_ar_dr(FM_OPL *OPL,int slot,int v)
{
        OPL_CH   *CH   = &OPL->P_CH[slot/2];
        OPL_SLOT *SLOT = &CH->SLOT[slot&1];
        int ar = v>>4;
        int dr = v&0x0f;

        SLOT->AR = ar ? &OPL->AR_TABLE[ar<<2] : RATE_0;
        SLOT->evsa = SLOT->AR[SLOT->ksr];
        if( SLOT->evm == ENV_MOD_AR ) SLOT->evs = SLOT->evsa;

        SLOT->DR = dr ? &OPL->DR_TABLE[dr<<2] : RATE_0;
        SLOT->evsd = SLOT->DR[SLOT->ksr];
        if( SLOT->evm == ENV_MOD_DR ) SLOT->evs = SLOT->evsd;
}

/* set sustain level & release rate */
inline void set_sl_rr(FM_OPL *OPL,int slot,int v)
{
        OPL_CH   *CH   = &OPL->P_CH[slot/2];
        OPL_SLOT *SLOT = &CH->SLOT[slot&1];
        int sl = v>>4;
        int rr = v & 0x0f;

        SLOT->SL = SL_TABLE[sl];
        if( SLOT->evm == ENV_MOD_DR ) SLOT->eve = SLOT->SL;
        SLOT->RR = &OPL->DR_TABLE[rr<<2];
        SLOT->evsr = SLOT->RR[SLOT->ksr];
        if( SLOT->evm == ENV_MOD_RR ) SLOT->evs = SLOT->evsr;
}

/* operator output calcrator */
#define OP_OUT(slot,env,con)   slot->wavetable[((slot->Cnt+con)/(0x1000000/SIN_ENT))&(SIN_ENT-1)][env]
/* ---------- calcrate one of channel ---------- */
inline void OPL_CALC_CH( OPL_CH *CH )
{
        uint32 env_out;
        OPL_SLOT *SLOT;

        feedback2 = 0;
        /* SLOT 1 */
        SLOT = &CH->SLOT[SLOT1];
        env_out=OPL_CALC_SLOT(SLOT);
        if( env_out < EG_ENT-1 )
        {
                /* PG */
                if(SLOT->vib) SLOT->Cnt += (SLOT->Incr*vib/VIB_RATE);
                else          SLOT->Cnt += SLOT->Incr;
                /* connectoion */
                if(CH->FB)
                {
                        int feedback1 = (CH->op1_out[0]+CH->op1_out[1])>>CH->FB;
                        CH->op1_out[1] = CH->op1_out[0];
                        *CH->connect1 += CH->op1_out[0] = OP_OUT(SLOT,env_out,feedback1);
                }
                else
                {
                        *CH->connect1 += OP_OUT(SLOT,env_out,0);
                }
        }else
        {
                CH->op1_out[1] = CH->op1_out[0];
                CH->op1_out[0] = 0;
        }
        /* SLOT 2 */
        SLOT = &CH->SLOT[SLOT2];
        env_out=OPL_CALC_SLOT(SLOT);
        if( env_out < EG_ENT-1 )
        {
                /* PG */
                if(SLOT->vib) SLOT->Cnt += (SLOT->Incr*vib/VIB_RATE);
                else          SLOT->Cnt += SLOT->Incr;
                /* connectoion */
                outd[0] += OP_OUT(SLOT,env_out, feedback2);
        }
}

/* ---------- calcrate rythm block ---------- */
#define WHITE_NOISE_db 6.0
inline void OPL_CALC_RH( OPL_CH *CH )
{
        uint32 env_tam,env_sd,env_top,env_hh;
        int whitenoise = int((std::rand()&1)*(WHITE_NOISE_db/EG_STEP));
        int tone8;

        OPL_SLOT *SLOT;
        int env_out;

        /* BD : same as FM serial mode and output level is large */
        feedback2 = 0;
        /* SLOT 1 */
        SLOT = &CH[6].SLOT[SLOT1];
        env_out=OPL_CALC_SLOT(SLOT);
        if( env_out < EG_ENT-1 )
        {
                /* PG */
                if(SLOT->vib) SLOT->Cnt += (SLOT->Incr*vib/VIB_RATE);
                else          SLOT->Cnt += SLOT->Incr;
                /* connectoion */
                if(CH[6].FB)
                {
                        int feedback1 = (CH[6].op1_out[0]+CH[6].op1_out[1])>>CH[6].FB;
                        CH[6].op1_out[1] = CH[6].op1_out[0];
                        feedback2 = CH[6].op1_out[0] = OP_OUT(SLOT,env_out,feedback1);
                }
                else
                {
                        feedback2 = OP_OUT(SLOT,env_out,0);
                }
        }else
        {
                feedback2 = 0;
                CH[6].op1_out[1] = CH[6].op1_out[0];
                CH[6].op1_out[0] = 0;
        }
        /* SLOT 2 */
        SLOT = &CH[6].SLOT[SLOT2];
        env_out=OPL_CALC_SLOT(SLOT);
        if( env_out < EG_ENT-1 )
        {
                /* PG */
                if(SLOT->vib) SLOT->Cnt += (SLOT->Incr*vib/VIB_RATE);
                else          SLOT->Cnt += SLOT->Incr;
                /* connectoion */
                outd[0] += OP_OUT(SLOT,env_out, feedback2)*2;
        }

        // SD  (17) = mul14[fnum7] + white noise
        // TAM (15) = mul15[fnum8]
        // TOP (18) = fnum6(mul18[fnum8]+whitenoise)
        // HH  (14) = fnum7(mul18[fnum8]+whitenoise) + white noise
        env_sd =OPL_CALC_SLOT(SLOT7_2) + whitenoise;
        env_tam=OPL_CALC_SLOT(SLOT8_1);
        env_top=OPL_CALC_SLOT(SLOT8_2);
        env_hh =OPL_CALC_SLOT(SLOT7_1) + whitenoise;

        /* PG */
        if(SLOT7_1->vib) SLOT7_1->Cnt += (2*SLOT7_1->Incr*vib/VIB_RATE);
        else             SLOT7_1->Cnt += 2*SLOT7_1->Incr;
        if(SLOT7_2->vib) SLOT7_2->Cnt += ((CH[7].fc*8)*vib/VIB_RATE);
        else             SLOT7_2->Cnt += (CH[7].fc*8);
        if(SLOT8_1->vib) SLOT8_1->Cnt += (SLOT8_1->Incr*vib/VIB_RATE);
        else             SLOT8_1->Cnt += SLOT8_1->Incr;
        if(SLOT8_2->vib) SLOT8_2->Cnt += ((CH[8].fc*48)*vib/VIB_RATE);
        else             SLOT8_2->Cnt += (CH[8].fc*48);

        tone8 = OP_OUT(SLOT8_2,whitenoise,0 );

        /* SD */
        if( env_sd < EG_ENT-1 )
                outd[0] += OP_OUT(SLOT7_1,env_sd, 0)*8;
        /* TAM */
        if( env_tam < EG_ENT-1 )
                outd[0] += OP_OUT(SLOT8_1,env_tam, 0)*2;
        /* TOP-CY */
        if( env_top < EG_ENT-1 )
                outd[0] += OP_OUT(SLOT7_2,env_top,tone8)*2;
        /* HH */
        if( env_hh  < EG_ENT-1 )
                outd[0] += OP_OUT(SLOT7_2,env_hh,tone8)*2;
}

/* ----------- initialize time tabls ----------- */
static void init_timetables( FM_OPL *OPL , int ARRATE , int DRRATE )
{
        int i;
        double rate;

        /* make attack rate & decay rate tables */
        for (i = 0;i < 4;i++) OPL->AR_TABLE[i] = OPL->DR_TABLE[i] = 0;
        for (i = 4;i <= 60;i++){
                rate  = OPL->freqbase;                                          /* frequency rate */
                if( i < 60 ) rate *= 1.0+(i&3)*0.25;            /* b0-1 : x1 , x1.25 , x1.5 , x1.75 */
                rate *= 1<<((i>>2)-1);                                          /* b2-5 : shift bit */
                rate *= (double)(EG_ENT<<ENV_BITS);
                OPL->AR_TABLE[i] = (int)(rate / ARRATE);
                OPL->DR_TABLE[i] = (int)(rate / DRRATE);
        }
        for (i = 60;i < 76;i++)
        {
                OPL->AR_TABLE[i] = EG_AED-1;
                OPL->DR_TABLE[i] = OPL->DR_TABLE[60];
        }
}

/* ---------- generic table initialize ---------- */
static int OPLOpenTable( void )
{
        int s,t;
        double rate;
        int i,j;
        double pom;

        /* allocate dynamic tables */
        if( (TL_TABLE = (int *)malloc(TL_MAX*2*sizeof(int))) == NULL)
                return 0;
        if( (SIN_TABLE = (int **)malloc(SIN_ENT*4 *sizeof(int *))) == NULL)
        {
                free(TL_TABLE);
                return 0;
        }
        if( (AMS_TABLE = (int *)malloc(AMS_ENT*2 *sizeof(int))) == NULL)
        {
                free(TL_TABLE);
                free(SIN_TABLE);
                return 0;
        }
        if( (VIB_TABLE = (int *)malloc(VIB_ENT*2 *sizeof(int))) == NULL)
        {
                free(TL_TABLE);
                free(SIN_TABLE);
                free(AMS_TABLE);
                return 0;
        }
        /* make total level table */
        for (t = 0;t < EG_ENT-1 ;t++){
                rate = ((1<<TL_BITS)-1)/std::pow(10.0,EG_STEP*t/20);    /* dB -> voltage */
                TL_TABLE[       t] =  (int)rate;
                TL_TABLE[TL_MAX+t] = -TL_TABLE[t];
        }
        /* fill volume off area */
        for ( t = EG_ENT-1; t < TL_MAX ;t++){
                TL_TABLE[t] = TL_TABLE[TL_MAX+t] = 0;
        }

        /* make sinwave table (total level offet) */
        /* degree 0 = degree 180                   = off */
        SIN_TABLE[0] = SIN_TABLE[SIN_ENT/2]         = &TL_TABLE[EG_ENT-1];
        for (s = 1;s <= SIN_ENT/4;s++){
                pom = std::sin(2*PI*s/SIN_ENT); /* sin     */
                pom = 20*std::log10(1/pom);        /* decibel */
                j = int(pom / EG_STEP);         /* TL_TABLE steps */

        /* degree 0   -  90    , degree 180 -  90 : plus section */
                SIN_TABLE[          s] = SIN_TABLE[SIN_ENT/2-s] = &TL_TABLE[j];
        /* degree 180 - 270    , degree 360 - 270 : minus section */
                SIN_TABLE[SIN_ENT/2+s] = SIN_TABLE[SIN_ENT  -s] = &TL_TABLE[TL_MAX+j];
        }
        for (s = 0;s < SIN_ENT;s++)
        {
                SIN_TABLE[SIN_ENT*1+s] = s<(SIN_ENT/2) ? SIN_TABLE[s] : &TL_TABLE[EG_ENT];
                SIN_TABLE[SIN_ENT*2+s] = SIN_TABLE[s % (SIN_ENT/2)];
                SIN_TABLE[SIN_ENT*3+s] = (s/(SIN_ENT/4))&1 ? &TL_TABLE[EG_ENT] : SIN_TABLE[SIN_ENT*2+s];
        }

        /* envelope counter -> envelope output table */
        for (i=0; i<EG_ENT; i++)
        {
                /* ATTACK curve */
                pom = std::pow( ((double)(EG_ENT-1-i)/EG_ENT) , 8 ) * EG_ENT;
                /* if( pom >= EG_ENT ) pom = EG_ENT-1; */
                ENV_CURVE[i] = (int)pom;
                /* DECAY ,RELEASE curve */
                ENV_CURVE[(EG_DST>>ENV_BITS)+i]= i;
        }
        /* off */
        ENV_CURVE[EG_OFF>>ENV_BITS]= EG_ENT-1;
        /* make LFO ams table */
        for (i=0; i<AMS_ENT; i++)
        {
                pom = (1.0+std::sin(2*PI*i/AMS_ENT))/2; /* sin */
                AMS_TABLE[i]         = (int)((1.0/EG_STEP)*pom); /* 1dB   */
                AMS_TABLE[AMS_ENT+i] = (int)((4.8/EG_STEP)*pom); /* 4.8dB */
        }
        /* make LFO vibrate table */
        for (i=0; i<VIB_ENT; i++)
        {
                /* 100cent = 1seminote = 6% ?? */
                pom = (double)VIB_RATE*0.06*std::sin(2*PI*i/VIB_ENT); /* +-100sect step */
                VIB_TABLE[i]         = (int)(VIB_RATE + (pom*0.07)); /* +- 7cent */
                VIB_TABLE[VIB_ENT+i] = (int)(VIB_RATE + (pom*0.14)); /* +-14cent */
        }
        return 1;
}


static void OPLCloseTable( void )
{
        free(TL_TABLE);
        free(SIN_TABLE);
        free(AMS_TABLE);
        free(VIB_TABLE);
}

/* CSM Key Controll */
inline void CSMKeyControll(OPL_CH *CH)
{
        OPL_SLOT *slot1 = &CH->SLOT[SLOT1];
        OPL_SLOT *slot2 = &CH->SLOT[SLOT2];
        /* all key off */
        OPL_KEYOFF(slot1);
        OPL_KEYOFF(slot2);
        /* total level latch */
        slot1->TLL = slot1->TL + (CH->ksl_base>>slot1->ksl);
        slot1->TLL = slot1->TL + (CH->ksl_base>>slot1->ksl);
        /* key on */
        CH->op1_out[0] = CH->op1_out[1] = 0;
        OPL_KEYON(slot1);
        OPL_KEYON(slot2);
}

/* ---------- opl initialize ---------- */
static void OPL_initalize(FM_OPL *OPL)
{
        int fn;

        /* frequency base */
        OPL->freqbase = (OPL->rate) ? ((double)OPL->clock / OPL->rate) / 72  : 0;
        /* Timer base time */
        OPL->TimerBase = 1.0/((double)OPL->clock / 72.0 );
        /* make time tables */
        init_timetables( OPL , OPL_ARRATE , OPL_DRRATE );
        /* make fnumber -> increment counter table */
        for( fn=0 ; fn < 1024 ; fn++ )
        {
                OPL->FN_TABLE[fn] = (uint32)(OPL->freqbase * fn * FREQ_RATE * (1<<7) / 2);
        }
        /* LFO freq.table */
        OPL->amsIncr = (int)(OPL->rate ? (double)AMS_ENT*(1<<AMS_SHIFT) / OPL->rate * 3.7 * ((double)OPL->clock/3600000) : 0);
        OPL->vibIncr = (int)(OPL->rate ? (double)VIB_ENT*(1<<VIB_SHIFT) / OPL->rate * 6.4 * ((double)OPL->clock/3600000) : 0);
}

/* ---------- write a OPL registers ---------- */
void OPLWriteReg(FM_OPL *OPL, int r, int v)
{
        OPL_CH *CH;
        int slot;
        uint32 block_fnum;

        switch(r&0xe0)
        {
        case 0x00: /* 00-1f:controll */
                switch(r&0x1f)
                {
                case 0x01:
                        /* wave selector enable */
                        if(OPL->type&OPL_TYPE_WAVESEL)
                        {
                                OPL->wavesel = v&0x20;
                                if(!OPL->wavesel)
                                {
                                        /* preset compatible mode */
                                        int c;
                                        for(c=0;c<OPL->max_ch;c++)
                                        {
                                                OPL->P_CH[c].SLOT[SLOT1].wavetable = &SIN_TABLE[0];
                                                OPL->P_CH[c].SLOT[SLOT2].wavetable = &SIN_TABLE[0];
                                        }
                                }
                        }
                        return;
                case 0x02:      /* Timer 1 */
                        OPL->T[0] = (256-v)*4;
                        break;
                case 0x03:      /* Timer 2 */
                        OPL->T[1] = (256-v)*16;
                        return;
                case 0x04:      /* IRQ clear / mask and Timer enable */
                        if(v&0x80)
                        {       /* IRQ flag clear */
                                OPL_STATUS_RESET(OPL,0x7f);
                        }
                        else
                        {       /* set IRQ mask ,timer enable*/
                                uint8 st1 = v&1;
                                uint8 st2 = (v>>1)&1;
                                /* IRQRST,T1MSK,t2MSK,EOSMSK,BRMSK,x,ST2,ST1 */
                                OPL_STATUS_RESET(OPL,v&0x78);
                                OPL_STATUSMASK_SET(OPL,((~v)&0x78)|0x01);
                                /* timer 2 */
                                if(OPL->st[1] != st2)
                                {
                                        double interval = st2 ? (double)OPL->T[1]*OPL->TimerBase : 0.0;
                                        OPL->st[1] = st2;
                                        if (OPL->TimerHandler) (OPL->TimerHandler)(OPL->TimerParam+1,interval);
                                }
                                /* timer 1 */
                                if(OPL->st[0] != st1)
                                {
                                        double interval = st1 ? (double)OPL->T[0]*OPL->TimerBase : 0.0;
                                        OPL->st[0] = st1;
                                        if (OPL->TimerHandler) (OPL->TimerHandler)(OPL->TimerParam+0,interval);
                                }
                        }
                        return;
                }
                break;
        case 0x20:      /* am,vib,ksr,eg type,mul */
                slot = slot_array[r&0x1f];
                if(slot == -1) return;
                set_mul(OPL,slot,v);
                return;
        case 0x40:
                slot = slot_array[r&0x1f];
                if(slot == -1) return;
                set_ksl_tl(OPL,slot,v);
                return;
        case 0x60:
                slot = slot_array[r&0x1f];
                if(slot == -1) return;
                set_ar_dr(OPL,slot,v);
                return;
        case 0x80:
                slot = slot_array[r&0x1f];
                if(slot == -1) return;
                set_sl_rr(OPL,slot,v);
                return;
        case 0xa0:
                switch(r)
                {
                case 0xbd:
                        /* amsep,vibdep,r,bd,sd,tom,tc,hh */
                        {
                        uint8 rkey = OPL->rythm^v;
                        OPL->ams_table = &AMS_TABLE[v&0x80 ? AMS_ENT : 0];
                        OPL->vib_table = &VIB_TABLE[v&0x40 ? VIB_ENT : 0];
                        OPL->rythm  = v&0x3f;
                        if(OPL->rythm&0x20)
                        {
                                /* BD key on/off */
                                if(rkey&0x10)
                                {
                                        if(v&0x10)
                                        {
                                                OPL->P_CH[6].op1_out[0] = OPL->P_CH[6].op1_out[1] = 0;
                                                OPL_KEYON(&OPL->P_CH[6].SLOT[SLOT1]);
                                                OPL_KEYON(&OPL->P_CH[6].SLOT[SLOT2]);
                                        }
                                        else
                                        {
                                                OPL_KEYOFF(&OPL->P_CH[6].SLOT[SLOT1]);
                                                OPL_KEYOFF(&OPL->P_CH[6].SLOT[SLOT2]);
                                        }
                                }
                                /* SD key on/off */
                                if(rkey&0x08)
                                {
                                        if(v&0x08) OPL_KEYON(&OPL->P_CH[7].SLOT[SLOT2]);
                                        else       OPL_KEYOFF(&OPL->P_CH[7].SLOT[SLOT2]);
                                }/* TAM key on/off */
                                if(rkey&0x04)
                                {
                                        if(v&0x04) OPL_KEYON(&OPL->P_CH[8].SLOT[SLOT1]);
                                        else       OPL_KEYOFF(&OPL->P_CH[8].SLOT[SLOT1]);
                                }
                                /* TOP-CY key on/off */
                                if(rkey&0x02)
                                {
                                        if(v&0x02) OPL_KEYON(&OPL->P_CH[8].SLOT[SLOT2]);
                                        else       OPL_KEYOFF(&OPL->P_CH[8].SLOT[SLOT2]);
                                }
                                /* HH key on/off */
                                if(rkey&0x01)
                                {
                                        if(v&0x01) OPL_KEYON(&OPL->P_CH[7].SLOT[SLOT1]);
                                        else       OPL_KEYOFF(&OPL->P_CH[7].SLOT[SLOT1]);
                                }
                        }
                        }
                        return;
                }
                /* keyon,block,fnum */
                if( (r&0x0f) > 8) return;
                CH = &OPL->P_CH[r&0x0f];
                if(!(r&0x10))
                {       /* a0-a8 */
                        block_fnum  = (CH->block_fnum&0x1f00) | v;
                }
                else
                {       /* b0-b8 */
                        int keyon = (v>>5)&1;
                        block_fnum = ((v&0x1f)<<8) | (CH->block_fnum&0xff);
                        if(CH->keyon != keyon)
                        {
                                if( (CH->keyon=keyon) )
                                {
                                        CH->op1_out[0] = CH->op1_out[1] = 0;
                                        OPL_KEYON(&CH->SLOT[SLOT1]);
                                        OPL_KEYON(&CH->SLOT[SLOT2]);
                                }
                                else
                                {
                                        OPL_KEYOFF(&CH->SLOT[SLOT1]);
                                        OPL_KEYOFF(&CH->SLOT[SLOT2]);
                                }
                        }
                }
                /* update */
                if(CH->block_fnum != block_fnum)
                {
                        int blockRv = 7-(block_fnum>>10);
                        int fnum   = block_fnum&0x3ff;
                        CH->block_fnum = block_fnum;

                        CH->ksl_base = KSL_TABLE[block_fnum>>6];
                        CH->fc = OPL->FN_TABLE[fnum]>>blockRv;
                        CH->kcode = CH->block_fnum>>9;
                        if( (OPL->mode&0x40) && CH->block_fnum&0x100) CH->kcode |=1;
                        CALC_FCSLOT(CH,&CH->SLOT[SLOT1]);
                        CALC_FCSLOT(CH,&CH->SLOT[SLOT2]);
                }
                return;
        case 0xc0:
                /* FB,C */
                if( (r&0x0f) > 8) return;
                CH = &OPL->P_CH[r&0x0f];
                {
                int feedback = (v>>1)&7;
                CH->FB   = feedback ? (8+1) - feedback : 0;
                CH->CON = v&1;
                set_algorythm(CH);
                }
                return;
        case 0xe0: /* wave type */
                slot = slot_array[r&0x1f];
                if(slot == -1) return;
                CH = &OPL->P_CH[slot/2];
                if(OPL->wavesel)
                {
                        CH->SLOT[slot&1].wavetable = &SIN_TABLE[(v&0x03)*SIN_ENT];
                }
                return;
        }
}

/* lock/unlock for common table */
static int OPL_LockTable(void)
{
        num_lock++;
        if(num_lock>1) return 0;
        /* first time */
        cur_chip = NULL;
        /* allocate total level table (128kb space) */
        if( !OPLOpenTable() )
        {
                num_lock--;
                return -1;
        }
        return 0;
}

static void OPL_UnLockTable(void)
{
        if(num_lock) num_lock--;
        if(num_lock) return;
        /* last time */
        cur_chip = NULL;
        OPLCloseTable();
}

/*******************************************************************************/
/*              YM3812 local section                                                   */
/*******************************************************************************/

/* ---------- update one of chip ----------- */
void YM3812UpdateOne_Mono(FM_OPL *OPL, sint16 *buffer, int length)
{
    int i;
        int data;
        sint16 *buf = buffer;
        uint32 amsCnt  = OPL->amsCnt;
        uint32 vibCnt  = OPL->vibCnt;
        uint8 rythm = OPL->rythm&0x20;
        OPL_CH *CH,*R_CH;

        if( (void *)OPL != cur_chip ){
                cur_chip = (void *)OPL;
                /* channel pointers */
                S_CH = OPL->P_CH;
                E_CH = &S_CH[9];
                /* rythm slot */
                SLOT7_1 = &S_CH[7].SLOT[SLOT1];
                SLOT7_2 = &S_CH[7].SLOT[SLOT2];
                SLOT8_1 = &S_CH[8].SLOT[SLOT1];
                SLOT8_2 = &S_CH[8].SLOT[SLOT2];
                /* LFO state */
                amsIncr = OPL->amsIncr;
                vibIncr = OPL->vibIncr;
                ams_table = OPL->ams_table;
                vib_table = OPL->vib_table;
        }
        R_CH = rythm ? &S_CH[6] : E_CH;
    for( i=0; i < length ; i++ )
        {
                /*            channel A         channel B         channel C      */
                /* LFO */
                ams = ams_table[(amsCnt+=amsIncr)>>AMS_SHIFT];
                vib = vib_table[(vibCnt+=vibIncr)>>VIB_SHIFT];
                outd[0] = 0;
                /* FM part */
                for(CH=S_CH ; CH < R_CH ; CH++)
                        OPL_CALC_CH(CH);
                /* Rythn part */
                if(rythm)
                        OPL_CALC_RH(S_CH);
                /* limit check */
                data = Limit( outd[0] , OPL_MAXOUT, OPL_MINOUT );
                /* store to sound buffer */
                buf[i] = data >> OPL_OUTSB;
        }

        OPL->amsCnt = amsCnt;
        OPL->vibCnt = vibCnt;
}

void YM3812UpdateOne_Stereo(FM_OPL *OPL, sint16 *buffer, int length)
{
    int i;
        int data;
        int left;
        int right;
        sint16 *buf = buffer;
        uint32 amsCnt  = OPL->amsCnt;
        uint32 vibCnt  = OPL->vibCnt;
        uint8 rythm = OPL->rythm&0x20;
        OPL_CH *CH,*R_CH;

        if( (void *)OPL != cur_chip ){
                cur_chip = (void *)OPL;
                /* channel pointers */
                S_CH = OPL->P_CH;
                E_CH = &S_CH[9];
                /* rythm slot */
                SLOT7_1 = &S_CH[7].SLOT[SLOT1];
                SLOT7_2 = &S_CH[7].SLOT[SLOT2];
                SLOT8_1 = &S_CH[8].SLOT[SLOT1];
                SLOT8_2 = &S_CH[8].SLOT[SLOT2];
                /* LFO state */
                amsIncr = OPL->amsIncr;
                vibIncr = OPL->vibIncr;
                ams_table = OPL->ams_table;
                vib_table = OPL->vib_table;
        }
        R_CH = rythm ? &S_CH[6] : E_CH;
    for( i=0; i < length ; i++ )
        {
                /*            channel A         channel B         channel C      */
                /* LFO */
                ams = ams_table[(amsCnt+=amsIncr)>>AMS_SHIFT];
                vib = vib_table[(vibCnt+=vibIncr)>>VIB_SHIFT];
                left = 0;
                right = 0;
                /* FM part */
                for(CH=S_CH ; CH < R_CH ; CH++)
                {
                        outd[0] = 0;
                        OPL_CALC_CH(CH);
                        if (CH->PAN <= 64) left += outd[0];
                        else left += (outd[0]>>6)*(127-CH->PAN);
                        if (CH->PAN >= 64) right += outd[0];
                        else right += (outd[0]>>6)*(CH->PAN);
                }
                /* Rythn part */
                if(rythm)
                {
                        outd[0] = 0;
                        OPL_CALC_RH(S_CH);
                        left += outd[0];
                        right += outd[0];
                }
                /* limit check */
                data = Limit( left , OPL_MAXOUT, OPL_MINOUT );
                /* store to sound buffer */
                buf[i*2] = data >> OPL_OUTSB;

                /* limit check */
                data = Limit( right , OPL_MAXOUT, OPL_MINOUT );
                /* store to sound buffer */
                buf[i*2+1] = data >> OPL_OUTSB;
        }

        OPL->amsCnt = amsCnt;
        OPL->vibCnt = vibCnt;
}

/* ---------- reset a chip ---------- */
void OPLResetChip(FM_OPL *OPL)
{
        int c,s;
        int i;

        /* reset chip */
        OPL->mode   = 0;        /* normal mode */
        OPL_STATUS_RESET(OPL,0x7f);
        /* reset with register write */
        OPLWriteReg(OPL,0x01,0); /* wabesel disable */
        OPLWriteReg(OPL,0x02,0); /* Timer1 */
        OPLWriteReg(OPL,0x03,0); /* Timer2 */
        OPLWriteReg(OPL,0x04,0); /* IRQ mask clear */
        for(i = 0xff ; i >= 0x20 ; i-- ) OPLWriteReg(OPL,i,0);
        /* reset OPerator paramater */
        for( c = 0 ; c < OPL->max_ch ; c++ )
        {
                OPL_CH *CH = &OPL->P_CH[c];
                OPL->P_CH[c].PAN = 64;
                for(s = 0 ; s < 2 ; s++ )
                {
                        /* wave table */
                        CH->SLOT[s].wavetable = &SIN_TABLE[0];
                        /* CH->SLOT[s].evm = ENV_MOD_RR; */
                        CH->SLOT[s].evc = EG_OFF;
                        CH->SLOT[s].eve = EG_OFF+1;
                        CH->SLOT[s].evs = 0;
                }
        }
}

/* ----------  Create a virtual YM3812 ----------       */
/* 'rate'  is sampling rate and 'bufsiz' is the size of the  */
FM_OPL *OPLCreate(int type, int clock, int rate)
{
        char *ptr;
        FM_OPL *OPL;
        int state_size;
        int max_ch = 9; /* normaly 9 channels */

        if( OPL_LockTable() ==-1) return NULL;
        /* allocate OPL state space */
        state_size  = sizeof(FM_OPL);
        state_size += sizeof(OPL_CH)*max_ch;

        /* allocate memory block */
        ptr = (char *)malloc(state_size);
        if(ptr==NULL) return NULL;

        /* clear */
        memset(ptr,0,state_size);
        OPL        = (FM_OPL *)ptr; ptr+=sizeof(FM_OPL);
        OPL->P_CH  = (OPL_CH *)ptr; ptr+=sizeof(OPL_CH)*max_ch;

        /* set channel state pointer */
        OPL->type  = type;
        OPL->clock = clock;
        OPL->rate  = rate;
        OPL->max_ch = max_ch;

        /* init grobal tables */
        OPL_initalize(OPL);

        /* reset chip */
        OPLResetChip(OPL);
        return OPL;
}

/* ----------  Destroy one of vietual YM3812 ----------       */
void OPLDestroy(FM_OPL *OPL)
{
        OPL_UnLockTable();
        free(OPL);
}

/* ----------  Option handlers ----------       */

void OPLSetTimerHandler(FM_OPL *OPL,OPL_TIMERHANDLER TimerHandler,int channelOffset)
{
        OPL->TimerHandler   = TimerHandler;
        OPL->TimerParam = channelOffset;
}
void OPLSetIRQHandler(FM_OPL *OPL,OPL_IRQHANDLER IRQHandler,int param)
{
        OPL->IRQHandler     = IRQHandler;
        OPL->IRQParam = param;
}
void OPLSetUpdateHandler(FM_OPL *OPL,OPL_UPDATEHANDLER UpdateHandler,int param)
{
        OPL->UpdateHandler = UpdateHandler;
        OPL->UpdateParam = param;
}

/* ---------- YM3812 I/O interface ---------- */
int OPLWrite(FM_OPL *OPL,int a,int v)
{
        if( !(a&1) )
        {       /* address port */
                OPL->address = v & 0xff;
        }
        else
        {       /* data port */
                if(OPL->UpdateHandler) OPL->UpdateHandler(OPL->UpdateParam,0);
                OPLWriteReg(OPL,OPL->address,v);
        }
        return OPL->status>>7;
}

unsigned char OPLRead(FM_OPL *OPL,int a)
{
        if( !(a&1) )
        {       /* status port */
                return OPL->status & (OPL->statusmask|0x80);
        }
        /* data port */
        switch(OPL->address)
        {
        case 0x05: /* KeyBoard IN */
                PERR(("OPL:read unmapped KEYBOARD port\n"));
                return 0;
        case 0x19: /* I/O DATA    */
                PERR(("OPL:read unmapped I/O port\n"));
                return 0;
        case 0x1a: /* PCM-DATA    */
                return 0;
        }
        return 0;
}

int OPLTimerOver(FM_OPL *OPL,int c)
{
        if( c )
        {       /* Timer B */
                OPL_STATUS_SET(OPL,0x20);
        }
        else
        {       /* Timer A */
                OPL_STATUS_SET(OPL,0x40);
                /* CSM mode key,TL controll */
                if( OPL->mode & 0x80 )
                {       /* CSM mode total level latch and auto key on */
                        int ch;
                        if(OPL->UpdateHandler) OPL->UpdateHandler(OPL->UpdateParam,0);
                        for(ch=0;ch<9;ch++)
                                CSMKeyControll( &OPL->P_CH[ch] );
                }
        }
        /* reload timer */
        if (OPL->TimerHandler) (OPL->TimerHandler)(OPL->TimerParam+c,(double)OPL->T[c]*OPL->TimerBase);
        return OPL->status>>7;
}

void OPLSetPan(FM_OPL *OPL,int c, int pan)
{
        if (c > 0 && c < OPL->max_ch)
                OPL->P_CH[c].PAN = pan;
}

};

#endif //USE_FMOPL_MIDI

---