/*

**

** File: fmopl.c -- software implementation of FM sound generator

**

** Copyright (C) 1999,2000 Tatsuyuki Satoh , MultiArcadeMachineEmurator development

**

** Version 0.37a

**

*/

/*

	preliminary :

	Problem :

	note:

*/

/* This version of fmopl.c is a fork of the MAME one, relicensed under the LGPL.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#define INLINE		__inline

#define HAS_YM3812	1

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <stdarg.h>

#include <math.h>

//#include "driver.h"		/* use M.A.M.E. */

#include "fmopl.h"

#ifndef PI

#define PI 3.14159265358979323846

#endif

/* -------------------- for debug --------------------- */

/* #define OPL_OUTPUT_LOG */

#ifdef OPL_OUTPUT_LOG

static FILE *opl_dbg_fp = NULL;

static FM_OPL *opl_dbg_opl[16];

static int opl_dbg_maxchip,opl_dbg_chip;

#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 DELTAT_MIXING_LEVEL (1) /* DELTA-T ADPCM MIXING LEVEL */

#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

};

/* key scale level */

/* table is 3dB/OCT , DV converts this in TL step at 6dB/OCT */

#define DV (EG_STEP/2)

static const UINT32 KSL_TABLE[8*16]=

{

	/* OCT 0 */

	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,

	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,

	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,

	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,

	/* OCT 1 */

	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,

	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,

	 0.000/DV, 0.750/DV, 1.125/DV, 1.500/DV,

	 1.875/DV, 2.250/DV, 2.625/DV, 3.000/DV,

	/* OCT 2 */

	 0.000/DV, 0.000/DV, 0.000/DV, 0.000/DV,

	 0.000/DV, 1.125/DV, 1.875/DV, 2.625/DV,

	 3.000/DV, 3.750/DV, 4.125/DV, 4.500/DV,

	 4.875/DV, 5.250/DV, 5.625/DV, 6.000/DV,

	/* OCT 3 */

	 0.000/DV, 0.000/DV, 0.000/DV, 1.875/DV,

	 3.000/DV, 4.125/DV, 4.875/DV, 5.625/DV,

	 6.000/DV, 6.750/DV, 7.125/DV, 7.500/DV,

	 7.875/DV, 8.250/DV, 8.625/DV, 9.000/DV,

	/* OCT 4 */

	 0.000/DV, 0.000/DV, 3.000/DV, 4.875/DV,

	 6.000/DV, 7.125/DV, 7.875/DV, 8.625/DV,

	 9.000/DV, 9.750/DV,10.125/DV,10.500/DV,

	10.875/DV,11.250/DV,11.625/DV,12.000/DV,

	/* OCT 5 */

	 0.000/DV, 3.000/DV, 6.000/DV, 7.875/DV,

	 9.000/DV,10.125/DV,10.875/DV,11.625/DV,

	12.000/DV,12.750/DV,13.125/DV,13.500/DV,

	13.875/DV,14.250/DV,14.625/DV,15.000/DV,

	/* OCT 6 */

	 0.000/DV, 6.000/DV, 9.000/DV,10.875/DV,

	12.000/DV,13.125/DV,13.875/DV,14.625/DV,

	15.000/DV,15.750/DV,16.125/DV,16.500/DV,

	16.875/DV,17.250/DV,17.625/DV,18.000/DV,

	/* OCT 7 */

	 0.000/DV, 9.000/DV,12.000/DV,13.875/DV,

	15.000/DV,16.125/DV,16.875/DV,17.625/DV,

	18.000/DV,18.750/DV,19.125/DV,19.500/DV,

	19.875/DV,20.250/DV,20.625/DV,21.000/DV

};

#undef DV

/* 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) (db*((3/EG_STEP)*(1<<ENV_BITS)))+EG_DST

static const INT32 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 INT32 *TL_TABLE;

/* pointers to TL_TABLE with sinwave output offset */

static INT32 **SIN_TABLE;

/* LFO table */

static INT32 *AMS_TABLE;

static INT32 *VIB_TABLE;

/* envelope output curve table */

/* attack + decay + OFF */

static INT32 ENV_CURVE[2*EG_ENT+1];

/* multiple table */

#define ML 2

static const UINT32 MUL_TABLE[16]= {

/* 1/2, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15 */

   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*ML

};

#undef ML

/* dummy attack / decay rate ( when rate == 0 ) */

static INT32 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 INT32 outd[1];

static INT32 ams;

static INT32 vib;

INT32  *ams_table;

INT32  *vib_table;

static INT32 amsIncr;

static INT32 vibIncr;

static INT32 feedback2;		/* connect for SLOT 2 */

/* log output level */

#define LOG_ERR  3      /* ERROR       */

#define LOG_WAR  2      /* WARNING     */

#define LOG_INF  1      /* INFORMATION */

//#define LOG_LEVEL LOG_INF

#define LOG_LEVEL	LOG_ERR

//#define LOG(n,x) if( (n)>=LOG_LEVEL ) logerror x

#define LOG(n,x)

/* --------------------- 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)

{

	INT32 *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  = (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 = (rand()&1)*(WHITE_NOISE_db/EG_STEP);

	INT32 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);