/*
**
** File: ym2413.c - software implementation of YM2413
**                  FM sound generator type OPLL
**
** Copyright (C) 2002 Jarek Burczynski
**
** Version 1.0
**


to do:

- make sure of the sinus amplitude bits

- make sure of the EG resolution bits (looks like the biggest
  modulation index generated by the modulator is 123, 124 = no modulation)
- find proper algorithm for attack phase of EG

- tune up instruments ROM

- support sample replay in test mode (it is NOT as simple as setting bit 0
  in register 0x0f and using register 0x10 for sample data).
  Which games use this feature ?
*/

// disable warnings C4018 and C4244 for microsoft visual c++ 2005
#if defined(_MSC_VER) && (_MSC_VER >= 1400)
#pragma warning( disable : 4018 )
#pragma warning( disable : 4244 )
#endif

#include <math.h>
#include "ym2413.h"

#define MAME_INLINE static
#define logerror(...)
#ifndef PI
#define PI 3.14159265358979323846
#endif

/* output final shift */
#define FINAL_SH  (0)
#define MAXOUT    (+32767)
#define MINOUT    (-32768)

#define FREQ_SH      16  /* 16.16 fixed point (frequency calculations) */
#define EG_SH      16  /* 16.16 fixed point (EG timing)              */
#define LFO_SH      24  /*  8.24 fixed point (LFO calculations)       */

#define FREQ_MASK    ((1<<FREQ_SH)-1)

/* envelope output entries */
#define ENV_BITS    10
#define ENV_LEN      (1<<ENV_BITS)
#define ENV_STEP    (128.0/ENV_LEN)

#define MAX_ATT_INDEX  ((1<<(ENV_BITS-2))-1) /*255*/
#define MIN_ATT_INDEX  (0)

/* sinwave entries */
#define SIN_BITS    10
#define SIN_LEN      (1<<SIN_BITS)
#define SIN_MASK    (SIN_LEN-1)

#define TL_RES_LEN    (256)  /* 8 bits addressing (real chip) */

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

/* Envelope Generator phases */

#define EG_DMP      5
#define EG_ATT      4
#define EG_DEC      3
#define EG_SUS      2
#define EG_REL      1
#define EG_OFF      0

/* save output as raw 16-bit sample */

//#define SAVE_SAMPLE

#ifdef SAVE_SAMPLE
MAME_INLINE signed int acc_calc(signed int value)
{
  if (value>=0)
  {
    if (value < 0x0200)
      return (value & ~0);
    if (value < 0x0400)
      return (value & ~1);
    if (value < 0x0800)
      return (value & ~3);
    if (value < 0x1000)
      return (value & ~7);
    if (value < 0x2000)
      return (value & ~15);
    if (value < 0x4000)
      return (value & ~31);
    return (value & ~63);
  }
  /*else value < 0*/
  if (value > -0x0200)
    return (~abs(value) & ~0);
  if (value > -0x0400)
    return (~abs(value) & ~1);
  if (value > -0x0800)
    return (~abs(value) & ~3);
  if (value > -0x1000)
    return (~abs(value) & ~7);
  if (value > -0x2000)
    return (~abs(value) & ~15);
  if (value > -0x4000)
    return (~abs(value) & ~31);
  return (~abs(value) & ~63);
}


static FILE *sample[1];
  #if 0  /*save to MONO file */
    #define SAVE_ALL_CHANNELS \
    {  signed int pom = acc_calc(mo); \
      fputc((unsigned short)pom&0xff,sample[0]); \
      fputc(((unsigned short)pom>>8)&0xff,sample[0]); \
    }
  #else  /*save to STEREO file */
    #define SAVE_ALL_CHANNELS \
    {  signed int pom = mo; \
      fputc((unsigned short)pom&0xff,sample[0]); \
      fputc(((unsigned short)pom>>8)&0xff,sample[0]); \
      pom = ro; \
      fputc((unsigned short)pom&0xff,sample[0]); \
      fputc(((unsigned short)pom>>8)&0xff,sample[0]); \
    }
    #define SAVE_SEPARATE_CHANNEL(j) \
    {  signed int pom = outchan; \
      fputc((unsigned short)pom&0xff,sample[0]); \
      fputc(((unsigned short)pom>>8)&0xff,sample[0]); \
      pom = chip->instvol_r[j]>>4; \
      fputc((unsigned short)pom&0xff,sample[0]); \
      fputc(((unsigned short)pom>>8)&0xff,sample[0]); \
    }
  #endif
#endif

/*#define LOG_CYM_FILE*/
#ifdef LOG_CYM_FILE
  FILE * cymfile = NULL;
#endif

typedef struct{
  UINT32  ar;      /* attack rate: AR<<2      */
  UINT32  dr;      /* decay rate:  DR<<2      */
  UINT32  rr;      /* release rate:RR<<2      */
  UINT8  KSR;    /* key scale rate        */
  UINT8  ksl;    /* keyscale level        */
  UINT8  ksr;    /* key scale rate: kcode>>KSR  */
  UINT8  mul;    /* multiple: mul_tab[ML]    */

  /* Phase Generator */
  UINT32  phase;    /* frequency counter      */
  UINT32  freq;    /* frequency counter step    */
  UINT8   fb_shift;  /* feedback shift value      */
  INT32   op1_out[2];  /* slot1 output for feedback  */

  /* Envelope Generator */
  UINT8  eg_type;  /* percussive/nonpercussive mode*/
  UINT8  state;    /* phase type          */
  UINT32  TL;      /* total level: TL << 2      */
  INT32  TLL;    /* adjusted now TL        */
  INT32  volume;    /* envelope counter        */
  UINT32  sl;      /* sustain level: sl_tab[SL]  */

  UINT8  eg_sh_dp;  /* (dump state)          */
  UINT8  eg_sel_dp;  /* (dump state)          */
  UINT8  eg_sh_ar;  /* (attack state)        */
  UINT8  eg_sel_ar;  /* (attack state)        */
  UINT8  eg_sh_dr;  /* (decay state)        */
  UINT8  eg_sel_dr;  /* (decay state)        */
  UINT8  eg_sh_rr;  /* (release state for non-perc.)*/
  UINT8  eg_sel_rr;  /* (release state for non-perc.)*/
  UINT8  eg_sh_rs;  /* (release state for perc.mode)*/
  UINT8  eg_sel_rs;  /* (release state for perc.mode)*/

  UINT32  key;    /* 0 = KEY OFF, >0 = KEY ON    */

  /* LFO */
  UINT32  AMmask;    /* LFO Amplitude Modulation enable mask */
  UINT8  vib;    /* LFO Phase Modulation enable flag (active high)*/

  /* waveform select */
  unsigned int wavetable;
} YM2413_OPLL_SLOT;

typedef struct{
    YM2413_OPLL_SLOT SLOT[2];
  /* phase generator state */
  UINT32  block_fnum;  /* block+fnum          */
  UINT32  fc;      /* Freq. freqement base      */
  UINT32  ksl_base;  /* KeyScaleLevel Base step    */
  UINT8   kcode;    /* key code (for key scaling)  */
  UINT8   sus;    /* sus on/off (release speed in percussive mode)*/
} YM2413_OPLL_CH;

/* chip state */
typedef struct {
    YM2413_OPLL_CH P_CH[9];                /* OPLL chips have 9 channels*/
  UINT8  instvol_r[9];      /* instrument/volume (or volume/volume in percussive mode)*/

  UINT32  eg_cnt;          /* global envelope generator counter  */
  UINT32  eg_timer;        /* global envelope generator counter works at frequency = chipclock/72 */
  UINT32  eg_timer_add;      /* step of eg_timer            */
  UINT32  eg_timer_overflow;    /* envelope generator timer overlfows every 1 sample (on real chip) */

  UINT8  rhythm;          /* Rhythm mode          */

  /* LFO */
  UINT32  lfo_am_cnt;
  UINT32  lfo_am_inc;
  UINT32  lfo_pm_cnt;
  UINT32  lfo_pm_inc;

  UINT32  noise_rng;        /* 23 bit noise shift register  */
  UINT32  noise_p;        /* current noise 'phase'    */
  UINT32  noise_f;        /* current noise period      */

/* instrument settings */
/*
  0-user instrument
  1-15 - fixed instruments
  16 -bass drum settings
  17,18 - other percussion instruments
*/
  UINT8 inst_tab[19][8];

  /* external event callback handlers */
  OPLL_UPDATEHANDLER UpdateHandler; /* stream update handler    */
  int UpdateParam;        /* stream update parameter    */

  UINT32  fn_tab[1024];      /* fnumber->increment counter  */

  UINT8 address;          /* address register        */
  UINT8 status;          /* status flag          */

  int clock;            /* master clock  (Hz)      */
  int rate;            /* sampling rate (Hz)      */
  double freqbase;        /* frequency base        */
} YM2413C;

/* key scale level */
/* table is 3dB/octave, DV converts this into 6dB/octave */
/* 0.1875 is bit 0 weight of the envelope counter (volume) expressed in the 'decibel' scale */
#define DV (0.1875/1.0)
static const double ksl_tab[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 level table (3dB per step) */
/* 0 - 15: 0, 3, 6, 9,12,15,18,21,24,27,30,33,36,39,42,45 (dB)*/
#define SC(db) (UINT32) ( db * (1.0/ENV_STEP) )
static const UINT32 sl_tab[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(15)
};
#undef SC


#define RATE_STEPS (8)
static const unsigned char eg_inc[15*RATE_STEPS]={

/*cycle:0 1  2 3  4 5  6 7*/

/* 0 */ 0,1, 0,1, 0,1, 0,1, /* rates 00..12 0 (increment by 0 or 1) */
/* 1 */ 0,1, 0,1, 1,1, 0,1, /* rates 00..12 1 */
/* 2 */ 0,1, 1,1, 0,1, 1,1, /* rates 00..12 2 */
/* 3 */ 0,1, 1,1, 1,1, 1,1, /* rates 00..12 3 */

/* 4 */ 1,1, 1,1, 1,1, 1,1, /* rate 13 0 (increment by 1) */
/* 5 */ 1,1, 1,2, 1,1, 1,2, /* rate 13 1 */
/* 6 */ 1,2, 1,2, 1,2, 1,2, /* rate 13 2 */
/* 7 */ 1,2, 2,2, 1,2, 2,2, /* rate 13 3 */

/* 8 */ 2,2, 2,2, 2,2, 2,2, /* rate 14 0 (increment by 2) */
/* 9 */ 2,2, 2,4, 2,2, 2,4, /* rate 14 1 */
/*10 */ 2,4, 2,4, 2,4, 2,4, /* rate 14 2 */
/*11 */ 2,4, 4,4, 2,4, 4,4, /* rate 14 3 */

/*12 */ 4,4, 4,4, 4,4, 4,4, /* rates 15 0, 15 1, 15 2, 15 3 (increment by 4) */
/*13 */ 8,8, 8,8, 8,8, 8,8, /* rates 15 2, 15 3 for attack */
/*14 */ 0,0, 0,0, 0,0, 0,0, /* infinity rates for attack and decay(s) */
};


#define O(a) (a*RATE_STEPS)

/*note that there is no O(13) in this table - it's directly in the code */
static const unsigned char eg_rate_select[16+64+16]={  /* Envelope Generator rates (16 + 64 rates + 16 RKS) */
/* 16 infinite time rates */
O(14),O(14),O(14),O(14),O(14),O(14),O(14),O(14),
O(14),O(14),O(14),O(14),O(14),O(14),O(14),O(14),

/* rates 00-12 */
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),
O( 0),O( 1),O( 2),O( 3),

/* rate 13 */
O( 4),O( 5),O( 6),O( 7),

/* rate 14 */
O( 8),O( 9),O(10),O(11),

/* rate 15 */
O(12),O(12),O(12),O(12),

/* 16 dummy rates (same as 15 3) */
O(12),O(12),O(12),O(12),O(12),O(12),O(12),O(12),
O(12),O(12),O(12),O(12),O(12),O(12),O(12),O(12),

};
#undef O

/*rate  0,    1,    2,    3,    4,   5,   6,   7,  8,  9, 10, 11, 12, 13, 14, 15 */
/*shift 13,   12,   11,   10,   9,   8,   7,   6,  5,  4,  3,  2,  1,  0,  0,  0 */
/*mask  8191, 4095, 2047, 1023, 511, 255, 127, 63, 31, 15, 7,  3,  1,  0,  0,  0 */

#define O(a) (a*1)
static const unsigned char eg_rate_shift[16+64+16]={  /* Envelope Generator counter shifts (16 + 64 rates + 16 RKS) */
/* 16 infinite time rates */
O(0),O(0),O(0),O(0),O(0),O(0),O(0),O(0),
O(0),O(0),O(0),O(0),O(0),O(0),O(0),O(0),

/* rates 00-12 */
O(13),O(13),O(13),O(13),
O(12),O(12),O(12),O(12),
O(11),O(11),O(11),O(11),
O(10),O(10),O(10),O(10),
O( 9),O( 9),O( 9),O( 9),
O( 8),O( 8),O( 8),O( 8),
O( 7),O( 7),O( 7),O( 7),
O( 6),O( 6),O( 6),O( 6),
O( 5),O( 5),O( 5),O( 5),
O( 4),O( 4),O( 4),O( 4),
O( 3),O( 3),O( 3),O( 3),
O( 2),O( 2),O( 2),O( 2),
O( 1),O( 1),O( 1),O( 1),

/* rate 13 */
O( 0),O( 0),O( 0),O( 0),

/* rate 14 */
O( 0),O( 0),O( 0),O( 0),

/* rate 15 */
O( 0),O( 0),O( 0),O( 0),

/* 16 dummy rates (same as 15 3) */
O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),
O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),O( 0),

};
#undef O


/* multiple table */
#define ML 2.0f
static const UINT8 mul_tab[16]= {
/* 1/2, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,10,12,12,15,15 */
   (UINT8)(0.50*ML), (UINT8)(1.00*ML), (UINT8)(2.00*ML), (UINT8)(3.00*ML), (UINT8)(4.00*ML), (UINT8)(5.00*ML), (UINT8)(6.00*ML), (UINT8)(7.00*ML),
   (UINT8)(8.00*ML), (UINT8)(9.00*ML), (UINT8)(10.00*ML), (UINT8)(10.00*ML), (UINT8)(12.00*ML), (UINT8)(12.00*ML), (UINT8)(15.00*ML), (UINT8)(15.00*ML)
};
#undef ML

/*  TL_TAB_LEN is calculated as:
*  11 - sinus amplitude bits     (Y axis)
*  2  - sinus sign bit           (Y axis)
*  TL_RES_LEN - sinus resolution (X axis)
*/
#define TL_TAB_LEN (11*2*TL_RES_LEN)
static signed int tl_tab[TL_TAB_LEN];

#define ENV_QUIET    (TL_TAB_LEN>>5)

/* sin waveform table in 'decibel' scale */
/* two waveforms on OPLL type chips */
static unsigned int sin_tab[SIN_LEN * 2];


/* LFO Amplitude Modulation table (verified on real YM3812)
   27 output levels (triangle waveform); 1 level takes one of: 192, 256 or 448 samples

   Length: 210 elements.

  Each of the elements has to be repeated
  exactly 64 times (on 64 consecutive samples).
  The whole table takes: 64 * 210 = 13440 samples.

We use data>>1, until we find what it really is on real chip...

*/

#define LFO_AM_TAB_ELEMENTS 210

static const UINT8 lfo_am_table[LFO_AM_TAB_ELEMENTS] = {
0,0,0,0,0,0,0,
1,1,1,1,
2,2,2,2,
3,3,3,3,
4,4,4,4,
5,5,5,5,
6,6,6,6,
7,7,7,7,
8,8,8,8,
9,9,9,9,
10,10,10,10,
11,11,11,11,
12,12,12,12,
13,13,13,13,
14,14,14,14,
15,15,15,15,
16,16,16,16,
17,17,17,17,
18,18,18,18,
19,19,19,19,
20,20,20,20,
21,21,21,21,
22,22,22,22,
23,23,23,23,
24,24,24,24,
25,25,25,25,
26,26,26,
25,25,25,25,
24,24,24,24,
23,23,23,23,
22,22,22,22,
21,21,21,21,
20,20,20,20,
19,19,19,19,
18,18,18,18,
17,17,17,17,
16,16,16,16,
15,15,15,15,
14,14,14,14,
13,13,13,13,
12,12,12,12,
11,11,11,11,
10,10,10,10,
9,9,9,9,
8,8,8,8,
7,7,7,7,
6,6,6,6,
5,5,5,5,
4,4,4,4,
3,3,3,3,
2,2,2,2,
1,1,1,1
};

/* LFO Phase Modulation table (verified on real YM2413) */
static const INT8 lfo_pm_table[8*8] = {

/* FNUM2/FNUM = 0 00xxxxxx (0x0000) */
0, 0, 0, 0, 0, 0, 0, 0,

/* FNUM2/FNUM = 0 01xxxxxx (0x0040) */
1, 0, 0, 0,-1, 0, 0, 0,

/* FNUM2/FNUM = 0 10xxxxxx (0x0080) */
2, 1, 0,-1,-2,-1, 0, 1,

/* FNUM2/FNUM = 0 11xxxxxx (0x00C0) */
3, 1, 0,-1,-3,-1, 0, 1,

/* FNUM2/FNUM = 1 00xxxxxx (0x0100) */
4, 2, 0,-2,-4,-2, 0, 2,

/* FNUM2/FNUM = 1 01xxxxxx (0x0140) */
5, 2, 0,-2,-5,-2, 0, 2,

/* FNUM2/FNUM = 1 10xxxxxx (0x0180) */
6, 3, 0,-3,-6,-3, 0, 3,

/* FNUM2/FNUM = 1 11xxxxxx (0x01C0) */
7, 3, 0,-3,-7,-3, 0, 3,
};






/* This is not 100% perfect yet but very close */
/*
 - multi parameters are 100% correct (instruments and drums)
 - LFO PM and AM enable are 100% correct
 - waveform DC and DM select are 100% correct
*/

static unsigned char table[19][8] = {
/* MULT  MULT modTL DcDmFb AR/DR AR/DR SL/RR SL/RR */
/*   0     1     2     3     4     5     6    7    */
  {0x49, 0x4c, 0x4c, 0x12, 0x00, 0x00, 0x00, 0x00 },  //0

  {0x61, 0x61, 0x1e, 0x17, 0xf0, 0x78, 0x00, 0x17 },  //1
  {0x13, 0x41, 0x1e, 0x0d, 0xd7, 0xf7, 0x13, 0x13 },  //2
  {0x13, 0x01, 0x99, 0x04, 0xf2, 0xf4, 0x11, 0x23 },  //3
  {0x21, 0x61, 0x1b, 0x07, 0xaf, 0x64, 0x40, 0x27 },  //4

//{0x22, 0x21, 0x1e, 0x09, 0xf0, 0x76, 0x08, 0x28 },  //5
  {0x22, 0x21, 0x1e, 0x06, 0xf0, 0x75, 0x08, 0x18 },  //5

//{0x31, 0x22, 0x16, 0x09, 0x90, 0x7f, 0x00, 0x08 },  //6
  {0x31, 0x22, 0x16, 0x05, 0x90, 0x71, 0x00, 0x13 },  //6

  {0x21, 0x61, 0x1d, 0x07, 0x82, 0x80, 0x10, 0x17 },  //7
  {0x23, 0x21, 0x2d, 0x16, 0xc0, 0x70, 0x07, 0x07 },  //8
  {0x61, 0x61, 0x1b, 0x06, 0x64, 0x65, 0x10, 0x17 },  //9

//{0x61, 0x61, 0x0c, 0x08, 0x85, 0xa0, 0x79, 0x07 },  //A
  {0x61, 0x61, 0x0c, 0x18, 0x85, 0xf0, 0x70, 0x07 },  //A

  {0x23, 0x01, 0x07, 0x11, 0xf0, 0xa4, 0x00, 0x22 },  //B
  {0x97, 0xc1, 0x24, 0x07, 0xff, 0xf8, 0x22, 0x12 },  //C

//{0x61, 0x10, 0x0c, 0x08, 0xf2, 0xc4, 0x40, 0xc8 },  //D
  {0x61, 0x10, 0x0c, 0x05, 0xf2, 0xf4, 0x40, 0x44 },  //D

  {0x01, 0x01, 0x55, 0x03, 0xf3, 0x92, 0xf3, 0xf3 },  //E
  {0x61, 0x41, 0x89, 0x03, 0xf1, 0xf4, 0xf0, 0x13 },  //F

/* drum instruments definitions */
/* MULTI MULTI modTL  xxx  AR/DR AR/DR SL/RR SL/RR */
/*   0     1     2     3     4     5     6    7    */
  {0x01, 0x01, 0x16, 0x00, 0xfd, 0xf8, 0x2f, 0x6d },/* BD(multi verified, modTL verified, mod env - verified(close), carr. env verifed) */
  {0x01, 0x01, 0x00, 0x00, 0xd8, 0xd8, 0xf9, 0xf8 },/* HH(multi verified), SD(multi not used) */
  {0x05, 0x01, 0x00, 0x00, 0xf8, 0xba, 0x49, 0x55 },/* TOM(multi,env verified), TOP CYM(multi verified, env verified) */
};

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

/* work table */
static void *cur_chip = NULL;  /* current chip pointer */
static YM2413_OPLL_SLOT *SLOT7_1,*SLOT7_2,*SLOT8_1,*SLOT8_2;

static signed int output[2];
static signed int outchan;

static UINT32  LFO_AM;
static INT32  LFO_PM;


MAME_INLINE int limit( int val, int max, int min ) {
  if ( val > max )
    val = max;
  else if ( val < min )
    val = min;

  return val;
}


/* advance LFO to next sample */
MAME_INLINE void advance_lfo(YM2413C *chip)
{
  /* LFO */
  chip->lfo_am_cnt += chip->lfo_am_inc;
  if (chip->lfo_am_cnt >= (LFO_AM_TAB_ELEMENTS<<LFO_SH) )  /* lfo_am_table is 210 elements long */
    chip->lfo_am_cnt -= (LFO_AM_TAB_ELEMENTS<<LFO_SH);

  LFO_AM = lfo_am_table[ chip->lfo_am_cnt >> LFO_SH ] >> 1;

  chip->lfo_pm_cnt += chip->lfo_pm_inc;
  LFO_PM = (chip->lfo_pm_cnt>>LFO_SH) & 7;
}

/* advance to next sample */
MAME_INLINE void advance(YM2413C *chip)
{
    YM2413_OPLL_CH *CH;
    YM2413_OPLL_SLOT *op;
  unsigned int i;

//profiler_mark(PROFILER_USER3);

  /* Envelope Generator */
  chip->eg_timer += chip->eg_timer_add;

  while (chip->eg_timer >= chip->eg_timer_overflow)
  {
    chip->eg_timer -= chip->eg_timer_overflow;

    chip->eg_cnt++;

    for (i=0; i<9*2; i++)
    {
      CH  = &chip->P_CH[i/2];

      op  = &CH->SLOT[i&1];

      switch(op->state)
      {

      case EG_DMP:    /* dump phase */
      /*dump phase is performed by both operators in each channel*/
      /*when CARRIER envelope gets down to zero level,
      **  phases in BOTH opearators are reset (at the same time ?)
      */
        if ( !(chip->eg_cnt & ((1<<op->eg_sh_dp)-1) ) )
        {
          op->volume += eg_inc[op->eg_sel_dp + ((chip->eg_cnt>>op->eg_sh_dp)&7)];

          if ( op->volume >= MAX_ATT_INDEX )
          {
            op->volume = MAX_ATT_INDEX;
            op->state = EG_ATT;
            /* restart Phase Generator  */
            op->phase = 0;
          }
        }
      break;

      case EG_ATT:    /* attack phase */
        if ( !(chip->eg_cnt & ((1<<op->eg_sh_ar)-1) ) )
        {
          op->volume += (~op->volume *
                                         (eg_inc[op->eg_sel_ar + ((chip->eg_cnt>>op->eg_sh_ar)&7)])
                                        ) >>2;

          if (op->volume <= MIN_ATT_INDEX)
          {
            op->volume = MIN_ATT_INDEX;
            op->state = EG_DEC;
          }
        }
      break;

      case EG_DEC:  /* decay phase */
        if ( !(chip->eg_cnt & ((1<<op->eg_sh_dr)-1) ) )
        {
          op->volume += eg_inc[op->eg_sel_dr + ((chip->eg_cnt>>op->eg_sh_dr)&7)];

          if ( op->volume >= op->sl )
            op->state = EG_SUS;
        }
      break;

      case EG_SUS:  /* sustain phase */
        /* this is important behaviour:
        one can change percusive/non-percussive modes on the fly and
        the chip will remain in sustain phase - verified on real YM3812 */

        if(op->eg_type)    /* non-percussive mode (sustained tone) */
        {
                  /* do nothing */
        }
        else        /* percussive mode */
        {
          /* during sustain phase chip adds Release Rate (in percussive mode) */
          if ( !(chip->eg_cnt & ((1<<op->eg_sh_rr)-1) ) )
          {
            op->volume += eg_inc[op->eg_sel_rr + ((chip->eg_cnt>>op->eg_sh_rr)&7)];

            if ( op->volume >= MAX_ATT_INDEX )
              op->volume = MAX_ATT_INDEX;
          }
          /* else do nothing in sustain phase */
        }
      break;

      case EG_REL:  /* release phase */
      /* exclude modulators in melody channels from performing anything in this mode*/
      /* allowed are only carriers in melody mode and rhythm slots in rhythm mode */

      /*This table shows which operators and on what conditions are allowed to perform EG_REL:
      (a) - always perform EG_REL
      (n) - never perform EG_REL
      (r) - perform EG_REL in Rhythm mode ONLY
        0: 0 (n),  1 (a)
        1: 2 (n),  3 (a)
        2: 4 (n),  5 (a)
        3: 6 (n),  7 (a)
        4: 8 (n),  9 (a)
        5: 10(n),  11(a)
        6: 12(r),  13(a)
        7: 14(r),  15(a)
        8: 16(r),  17(a)
      */
        if ( (i&1) || ((chip->rhythm&0x20) && (i>=12)) )/* exclude modulators */
        {
          if(op->eg_type)    /* non-percussive mode (sustained tone) */
          /*this is correct: use RR when SUS = OFF*/
          /*and use RS when SUS = ON*/
          {
            if (CH->sus)
            {
              if ( !(chip->eg_cnt & ((1<<op->eg_sh_rs)-1) ) )
              {
                op->volume += eg_inc[op->eg_sel_rs + ((chip->eg_cnt>>op->eg_sh_rs)&7)];
                if ( op->volume >= MAX_ATT_INDEX )
                {
                  op->volume = MAX_ATT_INDEX;
                  op->state = EG_OFF;
                }
              }
            }
            else
            {
              if ( !(chip->eg_cnt & ((1<<op->eg_sh_rr)-1) ) )
              {
                op->volume += eg_inc[op->eg_sel_rr + ((chip->eg_cnt>>op->eg_sh_rr)&7)];
                if ( op->volume >= MAX_ATT_INDEX )
                {
                  op->volume = MAX_ATT_INDEX;
                  op->state = EG_OFF;
                }
              }
            }
          }
          else        /* percussive mode */
          {
            if ( !(chip->eg_cnt & ((1<<op->eg_sh_rs)-1) ) )
            {
              op->volume += eg_inc[op->eg_sel_rs + ((chip->eg_cnt>>op->eg_sh_rs)&7)];
              if ( op->volume >= MAX_ATT_INDEX )
              {
                op->volume = MAX_ATT_INDEX;
                op->state = EG_OFF;
              }
            }
          }
        }
      break;

      default:
      break;
      }
    }
  }

//profiler_mark(PROFILER_END);

//profiler_mark(PROFILER_USER4);

  for (i=0; i<9*2; i++)
  {
    CH  = &chip->P_CH[i/2];
    op  = &CH->SLOT[i&1];

    /* Phase Generator */
    if(op->vib)
    {
      UINT8 block;

      unsigned int fnum_lfo   = 8*((CH->block_fnum&0x01c0) >> 6);
      unsigned int block_fnum = CH->block_fnum * 2;
      signed int lfo_fn_table_index_offset = lfo_pm_table[LFO_PM + fnum_lfo ];

      if (lfo_fn_table_index_offset)  /* LFO phase modulation active */
      {
        block_fnum += lfo_fn_table_index_offset;
        block = (block_fnum&0x1c00) >> 10;
        op->phase += (chip->fn_tab[block_fnum&0x03ff] >> (7-block)) * op->mul;
      }
      else  /* LFO phase modulation  = zero */
      {
        op->phase += op->freq;
      }
    }
    else  /* LFO phase modulation disabled for this operator */
    {
      op->phase += op->freq;
    }
  }

  /*  The Noise Generator of the YM3812 is 23-bit shift register.
  *  Period is equal to 2^23-2 samples.
  *  Register works at sampling frequency of the chip, so output
  *  can change on every sample.
  *
  *  Output of the register and input to the bit 22 is:
  *  bit0 XOR bit14 XOR bit15 XOR bit22
  *
  *  Simply use bit 22 as the noise output.
  */

  chip->noise_p += chip->noise_f;
  i = chip->noise_p >> FREQ_SH;    /* number of events (shifts of the shift register) */
  chip->noise_p &= FREQ_MASK;
  while (i)
  {
    /*
    UINT32 j;
    j = ( (chip->noise_rng) ^ (chip->noise_rng>>14) ^ (chip->noise_rng>>15) ^ (chip->noise_rng>>22) ) & 1;
    chip->noise_rng = (j<<22) | (chip->noise_rng>>1);
    */

    /*
      Instead of doing all the logic operations above, we
      use a trick here (and use bit 0 as the noise output).
      The difference is only that the noise bit changes one
      step ahead. This doesn't matter since we don't know
      what is real state of the noise_rng after the reset.
    */

    if (chip->noise_rng & 1) chip->noise_rng ^= 0x800302;
    chip->noise_rng >>= 1;

    i--;
  }
//profiler_mark(PROFILER_END);
}


MAME_INLINE signed int op_calc(UINT32 phase, unsigned int env, signed int pm, unsigned int wave_tab)
{
  UINT32 p;

  p = (env<<5) + sin_tab[wave_tab + ((((signed int)((phase & ~FREQ_MASK) + (pm<<17))) >> FREQ_SH ) & SIN_MASK) ];

  if (p >= TL_TAB_LEN)
    return 0;
  return tl_tab[p];
}

MAME_INLINE signed int op_calc1(UINT32 phase, unsigned int env, signed int pm, unsigned int wave_tab)
{
  UINT32 p;
  INT32  i;

  i = (phase & ~FREQ_MASK) + pm;

/*logerror("i=%08x (i>>16)&511=%8i phase=%i [pm=%08x] ",i, (i>>16)&511, phase>>FREQ_SH, pm);*/

  p = (env<<5) + sin_tab[ wave_tab + ((i>>FREQ_SH) & SIN_MASK)];

/*logerror("(p&255=%i p>>8=%i) out= %i\n", p&255,p>>8, tl_tab[p&255]>>(p>>8) );*/

  if (p >= TL_TAB_LEN)
    return 0;
  return tl_tab[p];
}


#define volume_calc(OP) ((OP)->TLL + ((UINT32)(OP)->volume) + (LFO_AM & (OP)->AMmask))

/* calculate output */
MAME_INLINE void chan_calc( YM2413_OPLL_CH *CH )
{
    YM2413_OPLL_SLOT *SLOT;
  unsigned int env;
  signed int out;
  signed int phase_modulation;  /* phase modulation input (SLOT 2) */


  /* SLOT 1 */
  SLOT = &CH->SLOT[SLOT1];
  env  = volume_calc(SLOT);
  out  = SLOT->op1_out[0] + SLOT->op1_out[1];

  SLOT->op1_out[0] = SLOT->op1_out[1];
  phase_modulation = SLOT->op1_out[0];

  SLOT->op1_out[1] = 0;

  if( env < ENV_QUIET )
  {
    if (!SLOT->fb_shift)
      out = 0;
    SLOT->op1_out[1] = op_calc1(SLOT->phase, env, (out<<SLOT->fb_shift), SLOT->wavetable );
  }

  /* SLOT 2 */

outchan=0;

  SLOT++;
  env = volume_calc(SLOT);
  if( env < ENV_QUIET )
  {
    signed int outp = op_calc(SLOT->phase, env, phase_modulation, SLOT->wavetable);
    output[0] += outp;
    outchan = outp;
    //output[0] += op_calc(SLOT->phase, env, phase_modulation, SLOT->wavetable);
  }
}

/*
  operators used in the rhythm sounds generation process:

  Envelope Generator:

channel  operator  register number   Bass  High  Snare Tom  Top
/ slot   number    TL ARDR SLRR Wave Drum  Hat   Drum  Tom  Cymbal
 6 / 0   12        50  70   90   f0  +
 6 / 1   15        53  73   93   f3  +
 7 / 0   13        51  71   91   f1        +
 7 / 1   16        54  74   94   f4              +
 8 / 0   14        52  72   92   f2                    +
 8 / 1   17        55  75   95   f5                          +

  Phase Generator:

channel  operator  register number   Bass  High  Snare Tom  Top
/ slot   number    MULTIPLE          Drum  Hat   Drum  Tom  Cymbal
 6 / 0   12        30                +
 6 / 1   15        33                +
 7 / 0   13        31                      +     +           +
 7 / 1   16        34                -----  n o t  u s e d -----
 8 / 0   14        32                                  +
 8 / 1   17        35                      +                 +

channel  operator  register number   Bass  High  Snare Tom  Top
number   number    BLK/FNUM2 FNUM    Drum  Hat   Drum  Tom  Cymbal
   6     12,15     B6        A6      +

   7     13,16     B7        A7            +     +           +

   8     14,17     B8        A8            +           +     +

*/

/* calculate rhythm */

MAME_INLINE void rhythm_calc( YM2413_OPLL_CH *CH, unsigned int noise )
{
    YM2413_OPLL_SLOT *SLOT;
  signed int out;
  unsigned int env;
  signed int phase_modulation;  /* phase modulation input (SLOT 2) */


  /* Bass Drum (verified on real YM3812):
    - depends on the channel 6 'connect' register:
        when connect = 0 it works the same as in normal (non-rhythm) mode (op1->op2->out)
        when connect = 1 _only_ operator 2 is present on output (op2->out), operator 1 is ignored
    - output sample always is multiplied by 2
  */


  /* SLOT 1 */
  SLOT = &CH[6].SLOT[SLOT1];
  env = volume_calc(SLOT);

  out = SLOT->op1_out[0] + SLOT->op1_out[1];
  SLOT->op1_out[0] = SLOT->op1_out[1];

  phase_modulation = SLOT->op1_out[0];

  SLOT->op1_out[1] = 0;
  if( env < ENV_QUIET )
  {
    if (!SLOT->fb_shift)
      out = 0;
    SLOT->op1_out[1] = op_calc1(SLOT->phase, env, (out<<SLOT->fb_shift), SLOT->wavetable );
  }

  /* SLOT 2 */
  SLOT++;
  env = volume_calc(SLOT);
  if( env < ENV_QUIET )
    output[1] += op_calc(SLOT->phase, env, phase_modulation, SLOT->wavetable) * 2;


  /* Phase generation is based on: */
  // HH  (13) channel 7->slot 1 combined with channel 8->slot 2 (same combination as TOP CYMBAL but different output phases)
  // SD  (16) channel 7->slot 1
  // TOM (14) channel 8->slot 1
  // TOP (17) channel 7->slot 1 combined with channel 8->slot 2 (same combination as HIGH HAT but different output phases)

  /* Envelope generation based on: */
  // HH  channel 7->slot1
  // SD  channel 7->slot2
  // TOM channel 8->slot1
  // TOP channel 8->slot2


  /* The following formulas can be well optimized.
     I leave them in direct form for now (in case I've missed something).
  */

  /* High Hat (verified on real YM3812) */
  env = volume_calc(SLOT7_1);
  if( env < ENV_QUIET )
  {

    /* high hat phase generation:
      phase = d0 or 234 (based on frequency only)
      phase = 34 or 2d0 (based on noise)
    */

    /* base frequency derived from operator 1 in channel 7 */
    unsigned char bit7 = ((SLOT7_1->phase>>FREQ_SH)>>7)&1;
    unsigned char bit3 = ((SLOT7_1->phase>>FREQ_SH)>>3)&1;
    unsigned char bit2 = ((SLOT7_1->phase>>FREQ_SH)>>2)&1;

    unsigned char res1 = (bit2 ^ bit7) | bit3;

    /* when res1 = 0 phase = 0x000 | 0xd0; */
    /* when res1 = 1 phase = 0x200 | (0xd0>>2); */
    UINT32 phase = res1 ? (0x200|(0xd0>>2)) : 0xd0;

    /* enable gate based on frequency of operator 2 in channel 8 */
    unsigned char bit5e= ((SLOT8_2->phase>>FREQ_SH)>>5)&1;
    unsigned char bit3e= ((SLOT8_2->phase>>FREQ_SH)>>3)&1;

    unsigned char res2 = (bit3e | bit5e);

    /* when res2 = 0 pass the phase from calculation above (res1); */
    /* when res2 = 1 phase = 0x200 | (0xd0>>2); */
    if (res2)
      phase = (0x200|(0xd0>>2));


    /* when phase & 0x200 is set and noise=1 then phase = 0x200|0xd0 */
    /* when phase & 0x200 is set and noise=0 then phase = 0x200|(0xd0>>2), ie no change */
    if (phase&0x200)
    {
      if (noise)
        phase = 0x200|0xd0;
    }
    else
    /* when phase & 0x200 is clear and noise=1 then phase = 0xd0>>2 */
    /* when phase & 0x200 is clear and noise=0 then phase = 0xd0, ie no change */
    {
      if (noise)
        phase = 0xd0>>2;
    }

    output[1] += op_calc(phase<<FREQ_SH, env, 0, SLOT7_1->wavetable) * 2;
  }

  /* Snare Drum (verified on real YM3812) */
  env = volume_calc(SLOT7_2);
  if( env < ENV_QUIET )
  {
    /* base frequency derived from operator 1 in channel 7 */
    unsigned char bit8 = ((SLOT7_1->phase>>FREQ_SH)>>8)&1;

    /* when bit8 = 0 phase = 0x100; */
    /* when bit8 = 1 phase = 0x200; */
    UINT32 phase = bit8 ? 0x200 : 0x100;

    /* Noise bit XOR'es phase by 0x100 */
    /* when noisebit = 0 pass the phase from calculation above */
    /* when noisebit = 1 phase ^= 0x100; */
    /* in other words: phase ^= (noisebit<<8); */
    if (noise)
      phase ^= 0x100;

    output[1] += op_calc(phase<<FREQ_SH, env, 0, SLOT7_2->wavetable) * 2;
  }

  /* Tom Tom (verified on real YM3812) */
  env = volume_calc(SLOT8_1);
  if( env < ENV_QUIET )
    output[1] += op_calc(SLOT8_1->phase, env, 0, SLOT8_1->wavetable) * 2;

  /* Top Cymbal (verified on real YM2413) */
  env = volume_calc(SLOT8_2);
  if( env < ENV_QUIET )
  {
    /* base frequency derived from operator 1 in channel 7 */
    unsigned char bit7 = ((SLOT7_1->phase>>FREQ_SH)>>7)&1;
    unsigned char bit3 = ((SLOT7_1->phase>>FREQ_SH)>>3)&1;
    unsigned char bit2 = ((SLOT7_1->phase>>FREQ_SH)>>2)&1;

    unsigned char res1 = (bit2 ^ bit7) | bit3;

    /* when res1 = 0 phase = 0x000 | 0x100; */
    /* when res1 = 1 phase = 0x200 | 0x100; */
    UINT32 phase = res1 ? 0x300 : 0x100;

    /* enable gate based on frequency of operator 2 in channel 8 */
    unsigned char bit5e= ((SLOT8_2->phase>>FREQ_SH)>>5)&1;
    unsigned char bit3e= ((SLOT8_2->phase>>FREQ_SH)>>3)&1;

    unsigned char res2 = (bit3e | bit5e);
    /* when res2 = 0 pass the phase from calculation above (res1); */
    /* when res2 = 1 phase = 0x200 | 0x100; */
    if (res2)
      phase = 0x300;

    output[1] += op_calc(phase<<FREQ_SH, env, 0, SLOT8_2->wavetable) * 2;
  }

}


/* generic table initialize */
static int init_tables(void)
{
  signed int i,x;
  signed int n;
  double o,m;


  for (x=0; x<TL_RES_LEN; x++)
  {
    m = (1<<16) / pow(2, (x+1) * (ENV_STEP/4.0) / 8.0);
    m = floor(m);

    /* we never reach (1<<16) here due to the (x+1) */
    /* result fits within 16 bits at maximum */

    n = (int)m;    /* 16 bits here */
    n >>= 4;    /* 12 bits here */
    if (n&1)    /* round to nearest */
      n = (n>>1)+1;
    else
      n = n>>1;
            /* 11 bits here (rounded) */
    tl_tab[ x*2 + 0 ] = n;
    tl_tab[ x*2 + 1 ] = -tl_tab[ x*2 + 0 ];

    for (i=1; i<11; i++)
    {
      tl_tab[ x*2+0 + i*2*TL_RES_LEN ] =  tl_tab[ x*2+0 ]>>i;
      tl_tab[ x*2+1 + i*2*TL_RES_LEN ] = -tl_tab[ x*2+0 + i*2*TL_RES_LEN ];
    }
  #if 0
      logerror("tl %04i", x*2);
      for (i=0; i<11; i++)
        logerror(", [%02i] %5i", i*2, tl_tab[ x*2 /*+1*/ + i*2*TL_RES_LEN ] );
      logerror("\n");
  #endif
  }
  /*logerror("ym2413.c: TL_TAB_LEN = %i elements (%i bytes)\n",TL_TAB_LEN, (int)sizeof(tl_tab));*/


  for (i=0; i<SIN_LEN; i++)
  {
    /* non-standard sinus */
    m = sin( ((i*2)+1) * PI / SIN_LEN ); /* checked against the real chip */

    /* we never reach zero here due to ((i*2)+1) */

    if (m>0.0)
      o = 8*log(1.0/m)/log(2.0);  /* convert to 'decibels' */
    else
      o = 8*log(-1.0/m)/log(2.0);  /* convert to 'decibels' */

    o = o / (ENV_STEP/4);

    n = (int)(2.0*o);
    if (n&1)            /* round to nearest */
      n = (n>>1)+1;
    else
      n = n>>1;

    /* waveform 0: standard sinus  */
    sin_tab[ i ] = n*2 + (m>=0.0? 0: 1 );

    /*logerror("ym2413.c: sin [%4i (hex=%03x)]= %4i (tl_tab value=%5i)\n", i, i, sin_tab[i], tl_tab[sin_tab[i]] );*/


    /* waveform 1:  __      __     */
    /*             /  \____/  \____*/
    /* output only first half of the sinus waveform (positive one) */
    if (i & (1<<(SIN_BITS-1)) )
      sin_tab[1*SIN_LEN+i] = TL_TAB_LEN;
    else
      sin_tab[1*SIN_LEN+i] = sin_tab[i];

    /*logerror("ym2413.c: sin1[%4i]= %4i (tl_tab value=%5i)\n", i, sin_tab[1*SIN_LEN+i], tl_tab[sin_tab[1*SIN_LEN+i]] );*/
  }
#if 0
  logerror("YM2413.C: ENV_QUIET= %08x (*32=%08x)\n", ENV_QUIET, ENV_QUIET*32 );
  for (i=0; i<ENV_QUIET; i++)
  {
    logerror("tl_tb[%4x(%4i)]=%8x\n", i<<5, i, tl_tab[i<<5] );
  }
#endif
#ifdef SAVE_SAMPLE
  sample[0]=fopen("sampsum.pcm","wb");
#endif

  return 1;
}

static void OPLCloseTable( void )
{
#ifdef SAVE_SAMPLE
  fclose(sample[0]);
#endif
}



static void OPLL_initalize(YM2413C *chip)
{
  int i;

  /* frequency base */
  chip->freqbase  = (chip->rate) ? ((double)chip->clock / 72.0) / chip->rate  : 0;
#if 0
  chip->rate = (double)chip->clock / 72.0;
  chip->freqbase  = 1.0;
  logerror("freqbase=%f\n", chip->freqbase);
#endif



  /* make fnumber -> increment counter table */
  for( i = 0 ; i < 1024; i++ )
  {
    /* OPLL (YM2413) phase increment counter = 18bit */

    chip->fn_tab[i] = (UINT32)( (double)i * 64 * chip->freqbase * (1<<(FREQ_SH-10)) ); /* -10 because chip works with 10.10 fixed point, while we use 16.16 */
#if 0
    logerror("ym2413.c: fn_tab[%4i] = %08x (dec=%8i)\n",
         i, chip->fn_tab[i]>>6, chip->fn_tab[i]>>6 );
#endif
  }

#if 0
  for( i=0 ; i < 16 ; i++ )
  {
    logerror("ym2413.c: sl_tab[%i] = %08x\n", i, sl_tab[i] );
  }
  for( i=0 ; i < 8 ; i++ )
  {
    int j;
    logerror("ym2413.c: ksl_tab[oct=%2i] =",i);
    for (j=0; j<16; j++)
    {
      logerror("%08x ", (UINT32)ksl_tab[i*16+j] );
    }
    logerror("\n");
  }
#endif


  /* Amplitude modulation: 27 output levels (triangle waveform); 1 level takes one of: 192, 256 or 448 samples */
  /* One entry from LFO_AM_TABLE lasts for 64 samples */
  chip->lfo_am_inc = (1.0 / 64.0 ) * (1<<LFO_SH) * chip->freqbase;

  /* Vibrato: 8 output levels (triangle waveform); 1 level takes 1024 samples */
  chip->lfo_pm_inc = (1.0 / 1024.0) * (1<<LFO_SH) * chip->freqbase;

  /*logerror ("chip->lfo_am_inc = %8x ; chip->lfo_pm_inc = %8x\n", chip->lfo_am_inc, chip->lfo_pm_inc);*/

  /* Noise generator: a step takes 1 sample */
  chip->noise_f = (1.0 / 1.0) * (1<<FREQ_SH) * chip->freqbase;
  /*logerror("YM2413init noise_f=%8x\n", chip->noise_f);*/

  chip->eg_timer_add  = (1<<EG_SH)  * chip->freqbase;
  chip->eg_timer_overflow = ( 1 ) * (1<<EG_SH);
  /*logerror("YM2413init eg_timer_add=%8x eg_timer_overflow=%8x\n", chip->eg_timer_add, chip->eg_timer_overflow);*/

}

MAME_INLINE void KEY_ON(YM2413_OPLL_SLOT *SLOT, UINT32 key_set)
{
  if( !SLOT->key )
  {
    /* do NOT restart Phase Generator (verified on real YM2413)*/
    /* phase -> Dump */
    SLOT->state = EG_DMP;
  }
  SLOT->key |= key_set;
}

MAME_INLINE void KEY_OFF(YM2413_OPLL_SLOT *SLOT, UINT32 key_clr)
{
  if( SLOT->key )
  {
    SLOT->key &= key_clr;

    if( !SLOT->key )
    {
      /* phase -> Release */
      if (SLOT->state>EG_REL)
        SLOT->state = EG_REL;
    }
  }
}

/* update phase increment counter of operator (also update the EG rates if necessary) */
MAME_INLINE void CALC_FCSLOT(YM2413_OPLL_CH *CH,YM2413_OPLL_SLOT *SLOT)
{
  int ksr;
  UINT32 SLOT_rs;
  UINT32 SLOT_dp;

  /* (frequency) phase increment counter */
  SLOT->freq = CH->fc * SLOT->mul;
  ksr = CH->kcode >> SLOT->KSR;

  if( SLOT->ksr != ksr )
  {
    SLOT->ksr = ksr;

    /* calculate envelope generator rates */
    if ((SLOT->ar + SLOT->ksr) < 16+62)
    {
      SLOT->eg_sh_ar  = eg_rate_shift [SLOT->ar + SLOT->ksr ];
      SLOT->eg_sel_ar = eg_rate_select[SLOT->ar + SLOT->ksr ];
    }
    else
    {
      SLOT->eg_sh_ar  = 0;
      SLOT->eg_sel_ar = 13*RATE_STEPS;
    }
    SLOT->eg_sh_dr  = eg_rate_shift [SLOT->dr + SLOT->ksr ];
    SLOT->eg_sel_dr = eg_rate_select[SLOT->dr + SLOT->ksr ];
    SLOT->eg_sh_rr  = eg_rate_shift [SLOT->rr + SLOT->ksr ];
    SLOT->eg_sel_rr = eg_rate_select[SLOT->rr + SLOT->ksr ];

  }

  if (CH->sus)
    SLOT_rs  = 16 + (5<<2);
  else
    SLOT_rs  = 16 + (7<<2);

  SLOT->eg_sh_rs  = eg_rate_shift [SLOT_rs + SLOT->ksr ];
  SLOT->eg_sel_rs = eg_rate_select[SLOT_rs + SLOT->ksr ];

  SLOT_dp  = 16 + (13<<2);
  SLOT->eg_sh_dp  = eg_rate_shift [SLOT_dp + SLOT->ksr ];
  SLOT->eg_sel_dp = eg_rate_select[SLOT_dp + SLOT->ksr ];
}

/* set multi,am,vib,EG-TYP,KSR,mul */
MAME_INLINE void set_mul(YM2413C *chip,int slot,int v)
{
    YM2413_OPLL_CH   *CH   = &chip->P_CH[slot/2];
    YM2413_OPLL_SLOT *SLOT = &CH->SLOT[slot&1];

  SLOT->mul     = mul_tab[v&0x0f];
  SLOT->KSR     = (v&0x10) ? 0 : 2;
  SLOT->eg_type = (v&0x20);
  SLOT->vib     = (v&0x40);
  SLOT->AMmask  = (v&0x80) ? ~0 : 0;
  CALC_FCSLOT(CH,SLOT);
}

/* set ksl, tl */
MAME_INLINE void set_ksl_tl(YM2413C *chip,int chan,int v)
{
  int ksl;
    YM2413_OPLL_CH   *CH   = &chip->P_CH[chan];
/* modulator */
    YM2413_OPLL_SLOT *SLOT = &CH->SLOT[SLOT1];

  ksl = v>>6; /* 0 / 1.5 / 3.0 / 6.0 dB/OCT */

  SLOT->ksl = ksl ? 3-ksl : 31;
  SLOT->TL  = (v&0x3f)<<(ENV_BITS-2-7); /* 7 bits TL (bit 6 = always 0) */
  SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
}

/* set ksl , waveforms, feedback */
MAME_INLINE void set_ksl_wave_fb(YM2413C *chip,int chan,int v)
{
  int ksl;
    YM2413_OPLL_CH   *CH   = &chip->P_CH[chan];
/* modulator */
    YM2413_OPLL_SLOT *SLOT = &CH->SLOT[SLOT1];
  SLOT->wavetable = ((v&0x08)>>3)*SIN_LEN;
  SLOT->fb_shift  = (v&7) ? (v&7) + 8 : 0;

/*carrier*/
  SLOT = &CH->SLOT[SLOT2];
  ksl = v>>6; /* 0 / 1.5 / 3.0 / 6.0 dB/OCT */

  SLOT->ksl = ksl ? 3-ksl : 31;
  SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);

  SLOT->wavetable = ((v&0x10)>>4)*SIN_LEN;
}

/* set attack rate & decay rate  */
MAME_INLINE void set_ar_dr(YM2413C *chip,int slot,int v)
{
    YM2413_OPLL_CH   *CH   = &chip->P_CH[slot/2];
    YM2413_OPLL_SLOT *SLOT = &CH->SLOT[slot&1];

  SLOT->ar = (v>>4)  ? 16 + ((v>>4)  <<2) : 0;

  if ((SLOT->ar + SLOT->ksr) < 16+62)
  {
    SLOT->eg_sh_ar  = eg_rate_shift [SLOT->ar + SLOT->ksr ];
    SLOT->eg_sel_ar = eg_rate_select[SLOT->ar + SLOT->ksr ];
  }
  else
  {
    SLOT->eg_sh_ar  = 0;
    SLOT->eg_sel_ar = 13*RATE_STEPS;
  }

  SLOT->dr    = (v&0x0f)? 16 + ((v&0x0f)<<2) : 0;
  SLOT->eg_sh_dr  = eg_rate_shift [SLOT->dr + SLOT->ksr ];
  SLOT->eg_sel_dr = eg_rate_select[SLOT->dr + SLOT->ksr ];
}

/* set sustain level & release rate */
MAME_INLINE void set_sl_rr(YM2413C *chip,int slot,int v)
{
    YM2413_OPLL_CH   *CH   = &chip->P_CH[slot/2];
    YM2413_OPLL_SLOT *SLOT = &CH->SLOT[slot&1];

  SLOT->sl  = sl_tab[ v>>4 ];

  SLOT->rr  = (v&0x0f)? 16 + ((v&0x0f)<<2) : 0;
  SLOT->eg_sh_rr  = eg_rate_shift [SLOT->rr + SLOT->ksr ];
  SLOT->eg_sel_rr = eg_rate_select[SLOT->rr + SLOT->ksr ];
}

static void load_instrument(YM2413C *chip, UINT32 chan, UINT32 slot, UINT8* inst )
{
  set_mul      (chip, slot,   inst[0]);
  set_mul      (chip, slot+1, inst[1]);
  set_ksl_tl    (chip, chan,   inst[2]);
  set_ksl_wave_fb  (chip, chan,   inst[3]);
  set_ar_dr    (chip, slot,   inst[4]);
  set_ar_dr    (chip, slot+1, inst[5]);
  set_sl_rr    (chip, slot,   inst[6]);
  set_sl_rr    (chip, slot+1, inst[7]);
}
static void update_instrument_zero(YM2413C *chip, UINT8 r )
{
  UINT8* inst = &chip->inst_tab[0][0]; /* point to user instrument */
  UINT32 chan;
  UINT32 chan_max;

  chan_max = 9;
  if (chip->rhythm & 0x20)
    chan_max=6;

  switch(r)
  {
  case 0:
    for (chan=0; chan<chan_max; chan++)
    {
      if ((chip->instvol_r[chan]&0xf0)==0)
      {
        set_mul      (chip, chan*2, inst[0]);
      }
    }
        break;
  case 1:
    for (chan=0; chan<chan_max; chan++)
    {
      if ((chip->instvol_r[chan]&0xf0)==0)
      {
        set_mul      (chip, chan*2+1,inst[1]);
      }
    }
        break;
  case 2:
    for (chan=0; chan<chan_max; chan++)
    {
      if ((chip->instvol_r[chan]&0xf0)==0)
      {
        set_ksl_tl    (chip, chan,   inst[2]);
      }
    }
        break;
  case 3:
    for (chan=0; chan<chan_max; chan++)
    {
      if ((chip->instvol_r[chan]&0xf0)==0)
      {
        set_ksl_wave_fb  (chip, chan,   inst[3]);
      }
    }
        break;
  case 4:
    for (chan=0; chan<chan_max; chan++)
    {
      if ((chip->instvol_r[chan]&0xf0)==0)
      {
        set_ar_dr    (chip, chan*2, inst[4]);
      }
    }
        break;
  case 5:
    for (chan=0; chan<chan_max; chan++)
    {
      if ((chip->instvol_r[chan]&0xf0)==0)
      {
        set_ar_dr    (chip, chan*2+1,inst[5]);
      }
    }
        break;
  case 6:
    for (chan=0; chan<chan_max; chan++)
    {
      if ((chip->instvol_r[chan]&0xf0)==0)
      {
        set_sl_rr    (chip, chan*2, inst[6]);
      }
    }
        break;
  case 7:
    for (chan=0; chan<chan_max; chan++)
    {
      if ((chip->instvol_r[chan]&0xf0)==0)
      {
        set_sl_rr    (chip, chan*2+1,inst[7]);
      }
    }
        break;
    }
}

/* write a value v to register r on chip chip */
static void OPLLWriteReg(YM2413C *chip, int r, int v)
{
    YM2413_OPLL_CH *CH;
    YM2413_OPLL_SLOT *SLOT;
  UINT8 *inst;
  int chan;
  int slot;

  /* adjust bus to 8 bits */
  r &= 0xff;
  v &= 0xff;


#ifdef LOG_CYM_FILE
  if ((cymfile) && (r!=8) )
  {
    fputc( (unsigned char)r, cymfile );
    fputc( (unsigned char)v, cymfile );
  }
#endif


  switch(r&0xf0)
  {
  case 0x00:  /* 00-0f:control */
  {
    switch(r&0x0f)
    {
    case 0x00:  /* AM/VIB/EGTYP/KSR/MULTI (modulator) */
    case 0x01:  /* AM/VIB/EGTYP/KSR/MULTI (carrier) */
    case 0x02:  /* Key Scale Level, Total Level (modulator) */
    case 0x03:  /* Key Scale Level, carrier waveform, modulator waveform, Feedback */
    case 0x04:  /* Attack, Decay (modulator) */
    case 0x05:  /* Attack, Decay (carrier) */
    case 0x06:  /* Sustain, Release (modulator) */
    case 0x07:  /* Sustain, Release (carrier) */
      chip->inst_tab[0][r & 0x07] = v;
      update_instrument_zero(chip,r&7);
    break;

    case 0x0e:  /* x, x, r,bd,sd,tom,tc,hh */
    {
      if(v&0x20)
      {
        if ((chip->rhythm&0x20)==0)
        /*rhythm off to on*/
        {
          logerror("YM2413: Rhythm mode enable\n");

  /* Load instrument settings for channel seven(chan=6 since we're zero based). (Bass drum) */
          chan = 6;
          inst = &chip->inst_tab[16][0];
          slot = chan*2;

          load_instrument(chip, chan, slot, inst);

  /* Load instrument settings for channel eight. (High hat and snare drum) */
          chan = 7;
          inst = &chip->inst_tab[17][0];
          slot = chan*2;

          load_instrument(chip, chan, slot, inst);

          CH   = &chip->P_CH[chan];
          SLOT = &CH->SLOT[SLOT1]; /* modulator envelope is HH */
          SLOT->TL  = ((chip->instvol_r[chan]>>4)<<2)<<(ENV_BITS-2-7); /* 7 bits TL (bit 6 = always 0) */
          SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);

  /* Load instrument settings for channel nine. (Tom-tom and top cymbal) */
          chan = 8;
          inst = &chip->inst_tab[18][0];
          slot = chan*2;

          load_instrument(chip, chan, slot, inst);

          CH   = &chip->P_CH[chan];
          SLOT = &CH->SLOT[SLOT1]; /* modulator envelope is TOM */
          SLOT->TL  = ((chip->instvol_r[chan]>>4)<<2)<<(ENV_BITS-2-7); /* 7 bits TL (bit 6 = always 0) */
          SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
        }
        /* BD key on/off */
        if(v&0x10)
        {
          KEY_ON (&chip->P_CH[6].SLOT[SLOT1], 2);
          KEY_ON (&chip->P_CH[6].SLOT[SLOT2], 2);
        }
        else
        {
          KEY_OFF(&chip->P_CH[6].SLOT[SLOT1],~2);
          KEY_OFF(&chip->P_CH[6].SLOT[SLOT2],~2);
        }
        /* HH key on/off */
        if(v&0x01) KEY_ON (&chip->P_CH[7].SLOT[SLOT1], 2);
        else       KEY_OFF(&chip->P_CH[7].SLOT[SLOT1],~2);
        /* SD key on/off */
        if(v&0x08) KEY_ON (&chip->P_CH[7].SLOT[SLOT2], 2);
        else       KEY_OFF(&chip->P_CH[7].SLOT[SLOT2],~2);
        /* TOM key on/off */
        if(v&0x04) KEY_ON (&chip->P_CH[8].SLOT[SLOT1], 2);
        else       KEY_OFF(&chip->P_CH[8].SLOT[SLOT1],~2);
        /* TOP-CY key on/off */
        if(v&0x02) KEY_ON (&chip->P_CH[8].SLOT[SLOT2], 2);
        else       KEY_OFF(&chip->P_CH[8].SLOT[SLOT2],~2);
      }
      else
      {
        if ((chip->rhythm&0x20)==1)
        /*rhythm on to off*/
        {
          logerror("YM2413: Rhythm mode disable\n");
  /* Load instrument settings for channel seven(chan=6 since we're zero based).*/
          chan = 6;
          inst = &chip->inst_tab[chip->instvol_r[chan]>>4][0];
          slot = chan*2;

          load_instrument(chip, chan, slot, inst);

  /* Load instrument settings for channel eight.*/
          chan = 7;
          inst = &chip->inst_tab[chip->instvol_r[chan]>>4][0];
          slot = chan*2;

          load_instrument(chip, chan, slot, inst);

  /* Load instrument settings for channel nine.*/
          chan = 8;
          inst = &chip->inst_tab[chip->instvol_r[chan]>>4][0];
          slot = chan*2;

          load_instrument(chip, chan, slot, inst);
        }
        /* BD key off */
        KEY_OFF(&chip->P_CH[6].SLOT[SLOT1],~2);
        KEY_OFF(&chip->P_CH[6].SLOT[SLOT2],~2);
        /* HH key off */
        KEY_OFF(&chip->P_CH[7].SLOT[SLOT1],~2);
        /* SD key off */
        KEY_OFF(&chip->P_CH[7].SLOT[SLOT2],~2);
        /* TOM key off */
        KEY_OFF(&chip->P_CH[8].SLOT[SLOT1],~2);
        /* TOP-CY off */
        KEY_OFF(&chip->P_CH[8].SLOT[SLOT2],~2);
      }
      chip->rhythm  = v&0x3f;
    }
    break;
    }
  }
  break;

  case 0x10:
  case 0x20:
  {
    int block_fnum;

    chan = r&0x0f;

    if (chan >= 9)
      chan -= 9;  /* verified on real YM2413 */

    CH = &chip->P_CH[chan];

    if(r&0x10)
    {  /* 10-18: FNUM 0-7 */
      block_fnum  = (CH->block_fnum&0x0f00) | v;
    }
    else
    {  /* 20-28: suson, keyon, block, FNUM 8 */
      block_fnum = ((v&0x0f)<<8) | (CH->block_fnum&0xff);

      if(v&0x10)
      {
        KEY_ON (&CH->SLOT[SLOT1], 1);
        KEY_ON (&CH->SLOT[SLOT2], 1);
      }
      else
      {
        KEY_OFF(&CH->SLOT[SLOT1],~1);
        KEY_OFF(&CH->SLOT[SLOT2],~1);
      }


      if (CH->sus!=(v&0x20))
      {
        logerror("chan=%i sus=%2x\n",chan,v&0x20);
      }
      CH->sus = v & 0x20;
    }
    /* update */
    if(CH->block_fnum != block_fnum)
    {
      UINT8 block;

      CH->block_fnum = block_fnum;

      /* BLK 2,1,0 bits -> bits 3,2,1 of kcode, FNUM MSB -> kcode LSB */
      CH->kcode    = (block_fnum&0x0f00)>>8;

      CH->ksl_base = (UINT32)ksl_tab[block_fnum>>5];

      block_fnum   = block_fnum * 2;
      block        = (block_fnum&0x1c00) >> 10;
      CH->fc       = chip->fn_tab[block_fnum&0x03ff] >> (7-block);

      /* refresh Total Level in both SLOTs of this channel */
      CH->SLOT[SLOT1].TLL = CH->SLOT[SLOT1].TL + (CH->ksl_base>>CH->SLOT[SLOT1].ksl);
      CH->SLOT[SLOT2].TLL = CH->SLOT[SLOT2].TL + (CH->ksl_base>>CH->SLOT[SLOT2].ksl);

      /* refresh frequency counter in both SLOTs of this channel */
      CALC_FCSLOT(CH,&CH->SLOT[SLOT1]);
      CALC_FCSLOT(CH,&CH->SLOT[SLOT2]);
    }
  }
  break;

  case 0x30:  /* inst 4 MSBs, VOL 4 LSBs */
  {
    UINT8 old_instvol;

    chan = r&0x0f;

    if (chan >= 9)
      chan -= 9;  /* verified on real YM2413 */

    old_instvol = chip->instvol_r[chan];
    chip->instvol_r[chan] = v;  /* store for later use */

    CH   = &chip->P_CH[chan];
    SLOT = &CH->SLOT[SLOT2]; /* carrier */
    SLOT->TL  = ((v&0x0f)<<2)<<(ENV_BITS-2-7); /* 7 bits TL (bit 6 = always 0) */
    SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);


    /*check wether we are in rhythm mode and handle instrument/volume register accordingly*/
    if ((chan>=6) && (chip->rhythm&0x20))
    {
      /* we're in rhythm mode*/

      if (chan>=7) /* only for channel 7 and 8 (channel 6 is handled in usual way)*/
      {
        SLOT = &CH->SLOT[SLOT1]; /* modulator envelope is HH(chan=7) or TOM(chan=8) */
        SLOT->TL  = ((chip->instvol_r[chan]>>4)<<2)<<(ENV_BITS-2-7); /* 7 bits TL (bit 6 = always 0) */
        SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
      }
    }
    else
    {
      if ( (old_instvol&0xf0) == (v&0xf0) )
        return;

      inst = &chip->inst_tab[chip->instvol_r[chan]>>4][0];
      slot = chan*2;

      load_instrument(chip, chan, slot, inst);

    #if 0
      logerror("YM2413: chan#%02i inst=%02i:  (r=%2x, v=%2x)\n",chan,v>>4,r,v);
      logerror("  0:%2x  1:%2x\n",inst[0],inst[1]);  logerror("  2:%2x  3:%2x\n",inst[2],inst[3]);
      logerror("  4:%2x  5:%2x\n",inst[4],inst[5]);  logerror("  6:%2x  7:%2x\n",inst[6],inst[7]);
    #endif
    }
  }
  break;

  default:
  break;
  }
}

#ifdef LOG_CYM_FILE
static void cymfile_callback (int n)
{
  if (cymfile)
  {
    fputc( (unsigned char)8, cymfile );
  }
}
#endif

/* lock/unlock for common table */
static int OPLL_LockTable(void)
{
  num_lock++;
  if(num_lock>1) return 0;

  /* first time */

  cur_chip = NULL;
  /* allocate total level table (128kb space) */
  if( !init_tables() )
  {
    num_lock--;
    return -1;
  }

#ifdef LOG_CYM_FILE
  cymfile = fopen("2413_.cym","wb");
  if (cymfile)
    timer_pulse ( TIME_IN_HZ(110), 0, cymfile_callback); /*110 Hz pulse timer*/
  else
    logerror("Could not create file 2413_.cym\n");
#endif

  return 0;
}

static void OPLL_UnLockTable(void)
{
  if(num_lock) num_lock--;
  if(num_lock) return;

  /* last time */

  cur_chip = NULL;
  OPLCloseTable();

#ifdef LOG_CYM_FILE
  fclose (cymfile);
  cymfile = NULL;
#endif

}

static void OPLLResetChip(YM2413C *chip)
{
  int c,s;
  int i;

  chip->eg_timer = 0;
  chip->eg_cnt   = 0;

  chip->noise_rng = 1;  /* noise shift register */


  /* setup instruments table */
  for (i=0; i<19; i++)
  {
    for (c=0; c<8; c++)
    {
      chip->inst_tab[i][c] = table[i][c];
    }
  }


  /* reset with register write */
  OPLLWriteReg(chip,0x0f,0); /*test reg*/
  for(i = 0x3f ; i >= 0x10 ; i-- ) OPLLWriteReg(chip,i,0x00);

  /* reset operator parameters */
  for( c = 0 ; c < 9 ; c++ )
  {
        YM2413_OPLL_CH *CH = &chip->P_CH[c];
    for(s = 0 ; s < 2 ; s++ )
    {
      /* wave table */
      CH->SLOT[s].wavetable = 0;
      CH->SLOT[s].state     = EG_OFF;
      CH->SLOT[s].volume    = MAX_ATT_INDEX;
    }
  }
}

/* Create one of virtual YM2413 */
/* 'clock' is chip clock in Hz  */
/* 'rate'  is sampling rate  */
static YM2413C *OPLLCreate(int clock, int rate)
{
  char *ptr;
  YM2413C *chip;
  int state_size;

  if (OPLL_LockTable() ==-1) return NULL;

  /* calculate chip state size */
  state_size  = sizeof(YM2413C);

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

  if (ptr==NULL)
    return NULL;

  /* clear */
  memset(ptr,0,state_size);

  chip  = (YM2413C *)ptr;

  chip->clock = clock;
  chip->rate  = rate;

  /* init global tables */
  OPLL_initalize(chip);

  /* reset chip */
  OPLLResetChip(chip);
  return chip;
}

/* Destroy one of virtual YM3812 */
static void OPLLDestroy(YM2413C *chip)
{
  OPLL_UnLockTable();
  free(chip);
}

/* Option handlers */

static void OPLLSetUpdateHandler(YM2413C *chip,OPLL_UPDATEHANDLER UpdateHandler,int param)
{
  chip->UpdateHandler = UpdateHandler;
  chip->UpdateParam = param;
}

/* YM3812 I/O interface */
static void OPLLWrite(YM2413C *chip,int a,int v)
{
  if( !(a&1) )
  {  /* address port */
    chip->address = v & 0xff;
  }
  else
  {  /* data port */
    if(chip->UpdateHandler)
		chip->UpdateHandler(chip->UpdateParam,0);
    OPLLWriteReg(chip,chip->address,v);
  }
}

static unsigned char OPLLRead(YM2413C *chip,int a)
{
  if( !(a&1) )
  {
    /* status port */
    return chip->status;
  }
  return 0xff;
}





#define MAX_OPLL_CHIPS 4


static YM2413C *OPLL_YM2413[MAX_OPLL_CHIPS];  /* array of pointers to the YM2413's */
static int YM2413NumChips = 0;        /* number of chips */

int YM2413Init(int num, int clock, int rate)
{
  int i;

  if (YM2413NumChips)
    return -1;  /* duplicate init. */

  YM2413NumChips = num;

  for (i = 0;i < YM2413NumChips; i++)
  {
    /* emulator create */
    OPLL_YM2413[i] = OPLLCreate(clock, rate);
    if(OPLL_YM2413[i] == NULL)
    {
      /* it's really bad - we run out of memeory */
      YM2413NumChips = 0;
      return -1;
    }
  }

  return 0;
}

void YM2413Shutdown(void)
{
  int i;

  for (i = 0;i < YM2413NumChips; i++)
  {
    /* emulator shutdown */
        if(OPLL_YM2413[i])
            OPLLDestroy(OPLL_YM2413[i]);
    OPLL_YM2413[i] = NULL;
  }
  YM2413NumChips = 0;
}

void YM2413ResetChip(int which)
{
  OPLLResetChip(OPLL_YM2413[which]);
}

void YM2413Write(int which, int a, int v)
{
  OPLLWrite(OPLL_YM2413[which], a, v);
}

unsigned char YM2413Read(int which, int a)
{
  return OPLLRead(OPLL_YM2413[which], a) & 0x03 ;
}

void YM2413SetUpdateHandler(int which,OPLL_UPDATEHANDLER UpdateHandler,int param)
{
  OPLLSetUpdateHandler(OPLL_YM2413[which], UpdateHandler, param);
}


/*
** Generate samples for one of the YM2413's
**
** 'which' is the virtual YM2413 number
** '*buffer' is the output buffer pointer
** 'length' is the number of samples that should be generated
*/
void YM2413UpdateOne(int which, INT16 **buffers, int length)
{
  YM2413C    *chip  = OPLL_YM2413[which];
  UINT8    rhythm = chip->rhythm&0x20;
  SAMP    *bufMO = buffers[0];
  SAMP    *bufRO = buffers[1];

  int i;

  if( (void *)chip != cur_chip ){
    cur_chip = (void *)chip;
    /* rhythm slots */
    SLOT7_1 = &chip->P_CH[7].SLOT[SLOT1];
    SLOT7_2 = &chip->P_CH[7].SLOT[SLOT2];
    SLOT8_1 = &chip->P_CH[8].SLOT[SLOT1];
    SLOT8_2 = &chip->P_CH[8].SLOT[SLOT2];
  }


  for( i=0; i < length ; i++ )
  {
    int mo,ro;

    output[0] = 0;
    output[1] = 0;

    advance_lfo(chip);

    /* FM part */
    chan_calc(&chip->P_CH[0]);
//SAVE_SEPARATE_CHANNEL(0);
    chan_calc(&chip->P_CH[1]);
    chan_calc(&chip->P_CH[2]);
    chan_calc(&chip->P_CH[3]);
    chan_calc(&chip->P_CH[4]);
    chan_calc(&chip->P_CH[5]);

    if(!rhythm)
    {
      chan_calc(&chip->P_CH[6]);
      chan_calc(&chip->P_CH[7]);
      chan_calc(&chip->P_CH[8]);
    }
    else    /* Rhythm part */
    {
      rhythm_calc(&chip->P_CH[0], (chip->noise_rng>>0)&1 );
    }

    mo = output[0];
    ro = output[1];

    mo >>= FINAL_SH;
    ro >>= FINAL_SH;

    /* limit check */
    mo = limit( mo , MAXOUT, MINOUT );
    ro = limit( ro , MAXOUT, MINOUT );

    #ifdef SAVE_SAMPLE
    if (which==0)
    {
      SAVE_ALL_CHANNELS
    }
    #endif

    /* store to sound buffer */
    bufMO[i] = mo;
    bufRO[i] = ro;

    advance(chip);
  }

}

/*
	Skelton for retropc emulator

	Author : Takeo.Namiki
	Date   : 2013.10.26-

	[ YM2413 ]
*/

void YM2413::initialize()
{
	buf[0] = buf[1] = NULL;
	mute = false;
}

void YM2413::release()
{
	if(buf[0]) {
		free(buf[0]);
	}
	if(buf[1]) {
		free(buf[1]);
	}
	YM2413Shutdown();
}

void YM2413::reset()
{
	touch_sound();
	YM2413ResetChip(0);
}

void YM2413::write_io8(uint32_t addr, uint32_t data)
{
	touch_sound();
	if (addr & 1) {
		reg[ latch & 0x3F] = data;
		latch = data;
	} else {
		latch = data;
	}
	YM2413Write(0, addr & 1, data);
}

uint32_t YM2413::read_io8(uint32_t addr)
{
	return latch;
}

void YM2413::mix(int32_t* buffer, int cnt)
{
	if(mute) {
		return;
	}
	if(cnt > 0) YM2413UpdateOne(0, buf, cnt);
	for(int i = 0; i < cnt; i++) {
//		int32_t vol1 = 0;
//		int32_t vol2 = 0;
//		vol1 += buf[0][i];
//		vol2 += buf[1][i];
//		*buffer++ += vol1<<2; // L
//		*buffer++ += vol2<<2; // R
		*buffer++ += apply_volume(buf[0][i] * 4, volume_l); // L
		*buffer++ += apply_volume(buf[1][i] * 4, volume_r); // R
	}
}

void YM2413::set_volume(int ch, int decibel_l, int decibel_r)
{
	volume_l = decibel_to_volume(decibel_l);
	volume_r = decibel_to_volume(decibel_r);
}

void YM2413::initialize_sound(int rate, int clock, int samples)
{
	YM2413Init(1, clock, rate);
	YM2413ResetChip(0);
	buf[0] = (INT16 *)malloc(sizeof(INT16) * samples * 2);
	buf[1] = (INT16 *)malloc(sizeof(INT16) * samples * 2);
}
