The-Homebrew-Cloud/Genesis-Plus-GX
2
0
Fork 0
mirror of https://github.com/ekeeke/Genesis-Plus-GX.git synced 2024-11-20 17:49:22 +01:00
Code Issues Packages Projects Releases Wiki Activity
e6774eed1b
Genesis-Plus-GX/core/sound/ym2413.c

1722 lines
49 KiB
C
Raw Blame History

/*
**
** 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 ?
*/
/** EkeEke (2011): removed multiple chips support, cleaned code & added FM board interface for Genesis Plus GX **/
#include "shared.h"
#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
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];
UINT32 fn_tab[1024]; /* fnumber->increment counter */
UINT8 address; /* address register */
UINT8 status; /* status flag */
double clock; /* master clock (Hz) */
int rate; /* sampling rate (Hz) */
} YM2413;
/* 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 UINT32 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
static const UINT8 mul_tab[16]= {
/* 1/2, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,10,12,12,15,15 */
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
/* 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) */
};
static signed int output[2];
static UINT32 LFO_AM;
static INT32 LFO_PM;
/* emulated chip */
static YM2413 ym2413;
/* advance LFO to next sample */
INLINE void advance_lfo(void)
{
/* LFO */
ym2413.lfo_am_cnt += ym2413.lfo_am_inc;
if (ym2413.lfo_am_cnt >= (LFO_AM_TAB_ELEMENTS<<LFO_SH) ) /* lfo_am_table is 210 elements long */
ym2413.lfo_am_cnt -= (LFO_AM_TAB_ELEMENTS<<LFO_SH);
LFO_AM = lfo_am_table[ ym2413.lfo_am_cnt >> LFO_SH ] >> 1;
ym2413.lfo_pm_cnt += ym2413.lfo_pm_inc;
LFO_PM = (ym2413.lfo_pm_cnt>>LFO_SH) & 7;
}
/* advance to next sample */
INLINE void advance(void)
{
YM2413_OPLL_CH *CH;
YM2413_OPLL_SLOT *op;
unsigned int i;
/* Envelope Generator */
ym2413.eg_timer += ym2413.eg_timer_add;
while (ym2413.eg_timer >= ym2413.eg_timer_overflow)
{
ym2413.eg_timer -= ym2413.eg_timer_overflow;
ym2413.eg_cnt++;
for (i=0; i<9*2; i++)
{
CH = &ym2413.P_CH[i>>1];
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 ( !(ym2413.eg_cnt & ((1<<op->eg_sh_dp)-1) ) )
{
op->volume += eg_inc[op->eg_sel_dp + ((ym2413.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 ( !(ym2413.eg_cnt & ((1<<op->eg_sh_ar)-1) ) )
{
op->volume += (~op->volume *
(eg_inc[op->eg_sel_ar + ((ym2413.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 ( !(ym2413.eg_cnt & ((1<<op->eg_sh_dr)-1) ) )
{
op->volume += eg_inc[op->eg_sel_dr + ((ym2413.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 ( !(ym2413.eg_cnt & ((1<<op->eg_sh_rr)-1) ) )
{
op->volume += eg_inc[op->eg_sel_rr + ((ym2413.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) || ((ym2413.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 ( !(ym2413.eg_cnt & ((1<<op->eg_sh_rs)-1) ) )
{
op->volume += eg_inc[op->eg_sel_rs + ((ym2413.eg_cnt>>op->eg_sh_rs)&7)];
if ( op->volume >= MAX_ATT_INDEX )
{
op->volume = MAX_ATT_INDEX;
op->state = EG_OFF;
}
}
}
else
{
if ( !(ym2413.eg_cnt & ((1<<op->eg_sh_rr)-1) ) )
{
op->volume += eg_inc[op->eg_sel_rr + ((ym2413.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 ( !(ym2413.eg_cnt & ((1<<op->eg_sh_rs)-1) ) )
{
op->volume += eg_inc[op->eg_sel_rs + ((ym2413.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;
}
}
}
for (i=0; i<9*2; i++)
{
CH = &ym2413.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 += (ym2413.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.
*/
ym2413.noise_p += ym2413.noise_f;
i = ym2413.noise_p >> FREQ_SH; /* number of events (shifts of the shift register) */
ym2413.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 (ym2413.noise_rng & 1) ym2413.noise_rng ^= 0x800302;
ym2413.noise_rng >>= 1;
i--;
}
}
INLINE signed int op_calc(UINT32 phase, unsigned int env, signed int pm, unsigned int wave_tab)
{
UINT32 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];
}
INLINE signed int op_calc1(UINT32 phase, unsigned int env, signed int pm, unsigned int wave_tab)
{
UINT32 p = (env<<5) + sin_tab[wave_tab + ((((signed int)((phase & ~FREQ_MASK) + pm)) >> FREQ_SH ) & SIN_MASK) ];
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 */
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 */
SLOT++;
env = volume_calc(SLOT);
if( env < ENV_QUIET )
{
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 */
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);
/* 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(&CH[7].SLOT[SLOT1]);
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 = ((CH[7].SLOT[SLOT1].phase>>FREQ_SH)>>7)&1;
unsigned char bit3 = ((CH[7].SLOT[SLOT1].phase>>FREQ_SH)>>3)&1;
unsigned char bit2 = ((CH[7].SLOT[SLOT1].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= ((CH[8].SLOT[SLOT2].phase>>FREQ_SH)>>5)&1;
unsigned char bit3e= ((CH[8].SLOT[SLOT2].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, CH[7].SLOT[SLOT1].wavetable);
}
/* Snare Drum (verified on real YM3812) */
env = volume_calc(&CH[7].SLOT[SLOT2]);
if( env < ENV_QUIET )
{
/* base frequency derived from operator 1 in channel 7 */
unsigned char bit8 = ((CH[7].SLOT[SLOT1].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, CH[7].SLOT[SLOT2].wavetable);
}
/* Tom Tom (verified on real YM3812) */
env = volume_calc(&CH[8].SLOT[SLOT1]);
if( env < ENV_QUIET )
output[1] += op_calc(CH[8].SLOT[SLOT1].phase, env, 0, CH[8].SLOT[SLOT1].wavetable);
/* Top Cymbal (verified on real YM2413) */
env = volume_calc(&CH[8].SLOT[SLOT2]);
if( env < ENV_QUIET )
{
/* base frequency derived from operator 1 in channel 7 */
unsigned char bit7 = ((CH[7].SLOT[SLOT1].phase>>FREQ_SH)>>7)&1;
unsigned char bit3 = ((CH[7].SLOT[SLOT1].phase>>FREQ_SH)>>3)&1;
unsigned char bit2 = ((CH[7].SLOT[SLOT1].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= ((CH[8].SLOT[SLOT2].phase>>FREQ_SH)>>5)&1;
unsigned char bit3e= ((CH[8].SLOT[SLOT2].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, CH[8].SLOT[SLOT2].wavetable);
}
}
/* 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 ];
}
}
for (i=0; i<SIN_LEN; i++)
{
/* non-standard sinus */
m = sin( ((i*2)+1) * M_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); /* convert to 'decibels' */
else
o = 8*log(-1.0/m)/log(2); /* 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 );
/* 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];
}
return 1;
}
static void OPLL_initalize(void)
{
int i;
/* YM2413 always running at original frequency */
double freqbase = 1.0;
/* make fnumber -> increment counter table */
for( i = 0 ; i < 1024; i++ )
{
/* OPLL (YM2413) phase increment counter = 18bit */
ym2413.fn_tab[i] = (UINT32)( (double)i * 64 * freqbase * (1<<(FREQ_SH-10)) ); /* -10 because chip works with 10.10 fixed point, while we use 16.16 */
}
/* 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 */
ym2413.lfo_am_inc = (1.0 / 64.0 ) * (1<<LFO_SH) * freqbase;
/* Vibrato: 8 output levels (triangle waveform); 1 level takes 1024 samples */
ym2413.lfo_pm_inc = (1.0 / 1024.0) * (1<<LFO_SH) * freqbase;
/* Noise generator: a step takes 1 sample */
ym2413.noise_f = (1.0 / 1.0) * (1<<FREQ_SH) * freqbase;
ym2413.eg_timer_add = (1<<EG_SH) * freqbase;
ym2413.eg_timer_overflow = ( 1 ) * (1<<EG_SH);
}
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;
}
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) */
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 */
INLINE void set_mul(int slot,int v)
{
YM2413_OPLL_CH *CH = &ym2413.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 */
INLINE void set_ksl_tl(int chan,int v)
{
YM2413_OPLL_CH *CH = &ym2413.P_CH[chan];
/* modulator */
YM2413_OPLL_SLOT *SLOT = &CH->SLOT[SLOT1];
int 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 */
INLINE void set_ksl_wave_fb(int chan,int v)
{
YM2413_OPLL_CH *CH = &ym2413.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];
SLOT->wavetable = ((v&0x10)>>4)*SIN_LEN;
v >>= 6; /* 0 / 1.5 / 3.0 / 6.0 dB/OCT */
SLOT->ksl = v ? 3-v : 31;
SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
}
/* set attack rate & decay rate */
INLINE void set_ar_dr(int slot,int v)
{
YM2413_OPLL_CH *CH = &ym2413.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 */
INLINE void set_sl_rr(int slot,int v)
{
YM2413_OPLL_CH *CH = &ym2413.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(UINT32 chan, UINT32 slot, UINT8* inst )
{
set_mul(slot, inst[0]);
set_mul(slot+1, inst[1]);
set_ksl_tl(chan, inst[2]);
set_ksl_wave_fb(chan, inst[3]);
set_ar_dr(slot, inst[4]);
set_ar_dr(slot+1, inst[5]);
set_sl_rr(slot, inst[6]);
set_sl_rr(slot+1, inst[7]);
}
static void update_instrument_zero(UINT8 r)
{
UINT8* inst = &ym2413.inst_tab[0][0]; /* point to user instrument */
UINT32 chan;
UINT32 chan_max = 9;
if (ym2413.rhythm & 0x20)
chan_max=6;
switch(r&7)
{
case 0:
for (chan=0; chan<chan_max; chan++)
{
if ((ym2413.instvol_r[chan]&0xf0)==0)
{
set_mul(chan*2, inst[0]);
}
}
break;
case 1:
for (chan=0; chan<chan_max; chan++)
{
if ((ym2413.instvol_r[chan]&0xf0)==0)
{
set_mul(chan*2+1, inst[1]);
}
}
break;
case 2:
for (chan=0; chan<chan_max; chan++)
{
if ((ym2413.instvol_r[chan]&0xf0)==0)
{
set_ksl_tl(chan, inst[2]);
}
}
break;
case 3:
for (chan=0; chan<chan_max; chan++)
{
if ((ym2413.instvol_r[chan]&0xf0)==0)
{
set_ksl_wave_fb(chan, inst[3]);
}
}
break;
case 4:
for (chan=0; chan<chan_max; chan++)
{
if ((ym2413.instvol_r[chan]&0xf0)==0)
{
set_ar_dr(chan*2, inst[4]);
}
}
break;
case 5:
for (chan=0; chan<chan_max; chan++)
{
if ((ym2413.instvol_r[chan]&0xf0)==0)
{
set_ar_dr(chan*2+1, inst[5]);
}
}
break;
case 6:
for (chan=0; chan<chan_max; chan++)
{
if ((ym2413.instvol_r[chan]&0xf0)==0)
{
set_sl_rr(chan*2, inst[6]);
}
}
break;
case 7:
for (chan=0; chan<chan_max; chan++)
{
if ((ym2413.instvol_r[chan]&0xf0)==0)
{
set_sl_rr(chan*2+1, inst[7]);
}
}
break;
}
}
/* write a value v to register r on chip chip */
static void OPLLWriteReg(int r, int v)
{
YM2413_OPLL_CH *CH;
YM2413_OPLL_SLOT *SLOT;
/* adjust bus to 8 bits */
r &= 0xff;
v &= 0xff;
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) */
{
ym2413.inst_tab[0][r] = v;
update_instrument_zero(r);
break;
}
case 0x0e: /* x, x, r,bd,sd,tom,tc,hh */
{
if(v&0x20)
{
/* rhythm OFF to ON */
if ((ym2413.rhythm&0x20)==0)
{
/* Load instrument settings for channel seven(chan=6 since we're zero based). (Bass drum) */
load_instrument(6, 12, &ym2413.inst_tab[16][0]);
/* Load instrument settings for channel eight. (High hat and snare drum) */
load_instrument(7, 14, &ym2413.inst_tab[17][0]);
CH = &ym2413.P_CH[7];
SLOT = &CH->SLOT[SLOT1]; /* modulator envelope is HH */
SLOT->TL = ((ym2413.instvol_r[7]>>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) */
load_instrument(8, 16, &ym2413.inst_tab[18][0]);
CH = &ym2413.P_CH[8];
SLOT = &CH->SLOT[SLOT1]; /* modulator envelope is TOM */
SLOT->TL = ((ym2413.instvol_r[8]>>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 (&ym2413.P_CH[6].SLOT[SLOT1], 2);
KEY_ON (&ym2413.P_CH[6].SLOT[SLOT2], 2);
}
else
{
KEY_OFF(&ym2413.P_CH[6].SLOT[SLOT1],~2);
KEY_OFF(&ym2413.P_CH[6].SLOT[SLOT2],~2);
}
/* HH key on/off */
if(v&0x01) KEY_ON (&ym2413.P_CH[7].SLOT[SLOT1], 2);
else KEY_OFF(&ym2413.P_CH[7].SLOT[SLOT1],~2);
/* SD key on/off */
if(v&0x08) KEY_ON (&ym2413.P_CH[7].SLOT[SLOT2], 2);
else KEY_OFF(&ym2413.P_CH[7].SLOT[SLOT2],~2);
/* TOM key on/off */
if(v&0x04) KEY_ON (&ym2413.P_CH[8].SLOT[SLOT1], 2);
else KEY_OFF(&ym2413.P_CH[8].SLOT[SLOT1],~2);
/* TOP-CY key on/off */
if(v&0x02) KEY_ON (&ym2413.P_CH[8].SLOT[SLOT2], 2);
else KEY_OFF(&ym2413.P_CH[8].SLOT[SLOT2],~2);
}
else
{
/* rhythm ON to OFF */
if (ym2413.rhythm&0x20)
{
/* Load instrument settings for channel seven(chan=6 since we're zero based).*/
load_instrument(6, 12, &ym2413.inst_tab[ym2413.instvol_r[6]>>4][0]);
/* Load instrument settings for channel eight.*/
load_instrument(7, 14, &ym2413.inst_tab[ym2413.instvol_r[7]>>4][0]);
/* Load instrument settings for channel nine.*/
load_instrument(8, 16, &ym2413.inst_tab[ym2413.instvol_r[8]>>4][0]);
}
/* BD key off */
KEY_OFF(&ym2413.P_CH[6].SLOT[SLOT1],~2);
KEY_OFF(&ym2413.P_CH[6].SLOT[SLOT2],~2);
/* HH key off */
KEY_OFF(&ym2413.P_CH[7].SLOT[SLOT1],~2);
/* SD key off */
KEY_OFF(&ym2413.P_CH[7].SLOT[SLOT2],~2);
/* TOM key off */
KEY_OFF(&ym2413.P_CH[8].SLOT[SLOT1],~2);
/* TOP-CY off */
KEY_OFF(&ym2413.P_CH[8].SLOT[SLOT2],~2);
}
ym2413.rhythm = v&0x3f;
break;
}
}
break;
}
case 0x10:
case 0x20:
{
int block_fnum;
int chan = r&0x0f;
if (chan >= 9)
chan -= 9; /* verified on real YM2413 */
CH = &ym2413.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);
}
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 = ksl_tab[block_fnum>>5];
block_fnum = block_fnum * 2;
block = (block_fnum&0x1c00) >> 10;
CH->fc = ym2413.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 */
{
int chan = r&0x0f;
if (chan >= 9)
chan -= 9; /* verified on real YM2413 */
CH = &ym2413.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) && (ym2413.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 = ((v>>4)<<2)<<(ENV_BITS-2-7); /* 7 bits TL (bit 6 = always 0) */
SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
}
}
else
{
if ((ym2413.instvol_r[chan]&0xf0) != (v&0xf0))
{
ym2413.instvol_r[chan] = v; /* store for later use */
load_instrument(chan, chan * 2, &ym2413.inst_tab[v>>4][0]);
}
}
break;
}
default:
break;
}
}
void YM2413Init(void)
{
init_tables();
/* clear */
memset(&ym2413,0,sizeof(YM2413));
/* init global tables */
OPLL_initalize();
}
void YM2413ResetChip(void)
{
int c,s;
int i;
ym2413.eg_timer = 0;
ym2413.eg_cnt = 0;
ym2413.noise_rng = 1; /* noise shift register */
/* setup instruments table */
for (i=0; i<19; i++)
{
for (c=0; c<8; c++)
{
ym2413.inst_tab[i][c] = table[i][c];
}
}
/* reset with register write */
OPLLWriteReg(0x0f,0); /*test reg*/
for(i = 0x3f ; i >= 0x10 ; i-- ) OPLLWriteReg(i,0x00);
/* reset operator parameters */
for( c = 0 ; c < 9 ; c++ )
{
YM2413_OPLL_CH *CH = &ym2413.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;
}
}
}
/* YM2413 I/O interface */
void YM2413Write(unsigned int a, unsigned int v)
{
if( !(a&2) )
{
if( !(a&1) )
{
/* address port */
ym2413.address = v & 0xff;
}
else
{
/* data port */
OPLLWriteReg(ym2413.address,v);
}
}
else
{
/* latched bit (Master System specific) */
ym2413.status = v & 0x01;
}
}
unsigned int YM2413Read(unsigned int a)
{
/* D0=latched bit, D1-D2 need to be zero (Master System specific) */
return 0xF8 | ym2413.status;
}
void YM2413Update(int *buffer, int length)
{
int i, out;
for( i=0; i < length ; i++ )
{
output[0] = 0;
output[1] = 0;
advance_lfo();
/* FM part */
chan_calc(&ym2413.P_CH[0]);
chan_calc(&ym2413.P_CH[1]);
chan_calc(&ym2413.P_CH[2]);
chan_calc(&ym2413.P_CH[3]);
chan_calc(&ym2413.P_CH[4]);
chan_calc(&ym2413.P_CH[5]);
if(!(ym2413.rhythm&0x20))
{
chan_calc(&ym2413.P_CH[6]);
chan_calc(&ym2413.P_CH[7]);
chan_calc(&ym2413.P_CH[8]);
}
else /* Rhythm part */
{
rhythm_calc(&ym2413.P_CH[0], (ym2413.noise_rng>>0)&1 );
}
/* Melody (MO) & Rythm (RO) outputs mixing & amplification (latched bit controls FM output) */
out = (output[0] + (output[1] * 2)) * 2 * ym2413.status;
/* Store to stereo sound buffer */
*buffer++ = out;
*buffer++ = out;
advance();
}
}
unsigned char *YM2413GetContextPtr(void)
{
return (unsigned char *)&ym2413;
}
unsigned int YM2413GetContextSize(void)
{
return sizeof(YM2413);
}
Reference in New Issue View Git Blame Copy Permalink