summaryrefslogtreecommitdiff
path: root/plugins/gme/game-music-emu-0.5.5/gme/Ym2612_Emu.cpp
blob: 390fdfced67b8b04958759ea4955ea010b14f921 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
// Game_Music_Emu 0.5.5. http://www.slack.net/~ant/

// Based on Gens 2.10 ym2612.c

#include "Ym2612_Emu.h"

#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <stdio.h>
#include <math.h>

/* Copyright (C) 2002 Stéphane Dallongeville (gens AT consolemul.com) */
/* Copyright (C) 2004-2006 Shay Green. This module is free software; you
can redistribute it and/or modify it under the terms of the GNU Lesser
General Public License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. This
module is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
details. You should have received a copy of the GNU Lesser General Public
License along with this module; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */

// This is mostly the original source in its C style and all.
//
// Somewhat optimized and simplified. Uses a template to generate the many
// variants of Update_Chan. Rewrote header file. In need of full rewrite by
// someone more familiar with FM sound and the YM2612. Has some inaccuracies
// compared to the Sega Genesis sound, particularly being mixed at such a
// high sample accuracy (the Genesis sounds like it has only 8 bit samples).
// - Shay

#ifdef BLARGG_ENABLE_OPTIMIZER
	#include BLARGG_ENABLE_OPTIMIZER
#endif

const int output_bits = 14;

struct slot_t
{
	const int *DT;  // parametre detune
	int MUL;    // parametre "multiple de frequence"
	int TL;     // Total Level = volume lorsque l'enveloppe est au plus haut
	int TLL;    // Total Level ajusted
	int SLL;    // Sustin Level (ajusted) = volume où l'enveloppe termine sa premiere phase de regression
	int KSR_S;  // Key Scale Rate Shift = facteur de prise en compte du KSL dans la variations de l'enveloppe
	int KSR;    // Key Scale Rate = cette valeur est calculee par rapport à la frequence actuelle, elle va influer
				// sur les differents parametres de l'enveloppe comme l'attaque, le decay ...  comme dans la realite !
	int SEG;    // Type enveloppe SSG
	int env_xor;
	int env_max;

	const int *AR;  // Attack Rate (table pointeur) = Taux d'attaque (AR[KSR])
	const int *DR;  // Decay Rate (table pointeur) = Taux pour la regression (DR[KSR])
	const int *SR;  // Sustin Rate (table pointeur) = Taux pour le maintien (SR[KSR])
	const int *RR;  // Release Rate (table pointeur) = Taux pour le rel'chement (RR[KSR])
	int Fcnt;   // Frequency Count = compteur-frequence pour determiner l'amplitude actuelle (SIN[Finc >> 16])
	int Finc;   // frequency step = pas d'incrementation du compteur-frequence
				// plus le pas est grand, plus la frequence est aïgu (ou haute)
	int Ecurp;  // Envelope current phase = cette variable permet de savoir dans quelle phase
				// de l'enveloppe on se trouve, par exemple phase d'attaque ou phase de maintenue ...
				// en fonction de la valeur de cette variable, on va appeler une fonction permettant
				// de mettre à jour l'enveloppe courante.
	int Ecnt;   // Envelope counter = le compteur-enveloppe permet de savoir où l'on se trouve dans l'enveloppe
	int Einc;   // Envelope step courant
	int Ecmp;   // Envelope counter limite pour la prochaine phase
	int EincA;  // Envelope step for Attack = pas d'incrementation du compteur durant la phase d'attaque
				// cette valeur est egal à AR[KSR]
	int EincD;  // Envelope step for Decay = pas d'incrementation du compteur durant la phase de regression
				// cette valeur est egal à DR[KSR]
	int EincS;  // Envelope step for Sustain = pas d'incrementation du compteur durant la phase de maintenue
				// cette valeur est egal à SR[KSR]
	int EincR;  // Envelope step for Release = pas d'incrementation du compteur durant la phase de rel'chement
				// cette valeur est egal à RR[KSR]
	int *OUTp;  // pointeur of SLOT output = pointeur permettant de connecter la sortie de ce slot à l'entree
				// d'un autre ou carrement à la sortie de la voie
	int INd;    // input data of the slot = donnees en entree du slot
	int ChgEnM; // Change envelop mask.
	int AMS;    // AMS depth level of this SLOT = degre de modulation de l'amplitude par le LFO
	int AMSon;  // AMS enable flag = drapeau d'activation de l'AMS
};

struct channel_t
{
	int S0_OUT[4];          // anciennes sorties slot 0 (pour le feed back)
	int LEFT;               // LEFT enable flag
	int RIGHT;              // RIGHT enable flag
	int ALGO;               // Algorythm = determine les connections entre les operateurs
	int FB;                 // shift count of self feed back = degre de "Feed-Back" du SLOT 1 (il est son unique entree)
	int FMS;                // Frequency Modulation Sensitivity of channel = degre de modulation de la frequence sur la voie par le LFO
	int AMS;                // Amplitude Modulation Sensitivity of channel = degre de modulation de l'amplitude sur la voie par le LFO
	int FNUM[4];            // hauteur frequence de la voie (+ 3 pour le mode special)
	int FOCT[4];            // octave de la voie (+ 3 pour le mode special)
	int KC[4];              // Key Code = valeur fonction de la frequence (voir KSR pour les slots, KSR = KC >> KSR_S)
	slot_t SLOT[4]; // four slot.operators = les 4 slots de la voie
	int FFlag;              // Frequency step recalculation flag
};

struct state_t
{
	int TimerBase;      // TimerBase calculation
	int Status;         // YM2612 Status (timer overflow)
	int TimerA;         // timerA limit = valeur jusqu'à laquelle le timer A doit compter
	int TimerAL;
	int TimerAcnt;      // timerA counter = valeur courante du Timer A
	int TimerB;         // timerB limit = valeur jusqu'à laquelle le timer B doit compter
	int TimerBL;
	int TimerBcnt;      // timerB counter = valeur courante du Timer B
	int Mode;           // Mode actuel des voie 3 et 6 (normal / special)
	int DAC;            // DAC enabled flag
	channel_t CHANNEL[Ym2612_Emu::channel_count];   // Les 6 voies du YM2612
	int REG[2][0x100];  // Sauvegardes des valeurs de tout les registres, c'est facultatif
						// cela nous rend le debuggage plus facile
};

#ifndef PI
#define PI 3.14159265358979323846
#endif

#define ATTACK    0
#define DECAY     1
#define SUBSTAIN  2
#define RELEASE   3

// SIN_LBITS <= 16
// LFO_HBITS <= 16
// (SIN_LBITS + SIN_HBITS) <= 26
// (ENV_LBITS + ENV_HBITS) <= 28
// (LFO_LBITS + LFO_HBITS) <= 28

#define SIN_HBITS      12                               // Sinus phase counter int part
#define SIN_LBITS      (26 - SIN_HBITS)                 // Sinus phase counter float part (best setting)

#if (SIN_LBITS > 16)
#define SIN_LBITS      16                               // Can't be greater than 16 bits
#endif

#define ENV_HBITS      12                               // Env phase counter int part
#define ENV_LBITS      (28 - ENV_HBITS)                 // Env phase counter float part (best setting)

#define LFO_HBITS      10                               // LFO phase counter int part
#define LFO_LBITS      (28 - LFO_HBITS)                 // LFO phase counter float part (best setting)

#define SIN_LENGHT     (1 << SIN_HBITS)
#define ENV_LENGHT     (1 << ENV_HBITS)
#define LFO_LENGHT     (1 << LFO_HBITS)

#define TL_LENGHT      (ENV_LENGHT * 3)                 // Env + TL scaling + LFO

#define SIN_MASK       (SIN_LENGHT - 1)
#define ENV_MASK       (ENV_LENGHT - 1)
#define LFO_MASK       (LFO_LENGHT - 1)

#define ENV_STEP       (96.0 / ENV_LENGHT)              // ENV_MAX = 96 dB

#define ENV_ATTACK     ((ENV_LENGHT * 0) << ENV_LBITS)
#define ENV_DECAY      ((ENV_LENGHT * 1) << ENV_LBITS)
#define ENV_END        ((ENV_LENGHT * 2) << ENV_LBITS)

#define MAX_OUT_BITS   (SIN_HBITS + SIN_LBITS + 2)      // Modulation = -4 <--> +4
#define MAX_OUT        ((1 << MAX_OUT_BITS) - 1)

#define PG_CUT_OFF     ((int) (78.0 / ENV_STEP))
#define ENV_CUT_OFF    ((int) (68.0 / ENV_STEP))

#define AR_RATE        399128
#define DR_RATE        5514396

//#define AR_RATE        426136
//#define DR_RATE        (AR_RATE * 12)

#define LFO_FMS_LBITS  9    // FIXED (LFO_FMS_BASE gives somethink as 1)
#define LFO_FMS_BASE   ((int) (0.05946309436 * 0.0338 * (double) (1 << LFO_FMS_LBITS)))

#define S0             0    // Stupid typo of the YM2612
#define S1             2
#define S2             1
#define S3             3

inline void set_seg( slot_t& s, int seg )
{
	s.env_xor = 0;
	s.env_max = INT_MAX;
	s.SEG = seg;
	if ( seg & 4 )
	{
		s.env_xor = ENV_MASK;
		s.env_max = ENV_MASK;
	}
}

struct tables_t
{
	short SIN_TAB [SIN_LENGHT];                 // SINUS TABLE (offset into TL TABLE)
	int LFOcnt;         // LFO counter = compteur-frequence pour le LFO
	int LFOinc;         // LFO step counter = pas d'incrementation du compteur-frequence du LFO
						// plus le pas est grand, plus la frequence est grande
	unsigned int AR_TAB [128];                  // Attack rate table
	unsigned int DR_TAB [96];                   // Decay rate table
	unsigned int DT_TAB [8] [32];               // Detune table
	unsigned int SL_TAB [16];                   // Substain level table
	unsigned int NULL_RATE [32];                // Table for NULL rate
	int LFO_INC_TAB [8];                        // LFO step table
	
	short ENV_TAB [2 * ENV_LENGHT + 8];         // ENV CURVE TABLE (attack & decay)
	
	short LFO_ENV_TAB [LFO_LENGHT];             // LFO AMS TABLE (adjusted for 11.8 dB)
	short LFO_FREQ_TAB [LFO_LENGHT];            // LFO FMS TABLE
	int TL_TAB [TL_LENGHT * 2];                 // TOTAL LEVEL TABLE (positif and minus)
	unsigned int DECAY_TO_ATTACK [ENV_LENGHT];  // Conversion from decay to attack phase
	unsigned int FINC_TAB [2048];               // Frequency step table
};

static const unsigned char DT_DEF_TAB [4 * 32] =
{
// FD = 0
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

// FD = 1
  0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2,
  2, 3, 3, 3, 4, 4, 4, 5, 5, 6, 6, 7, 8, 8, 8, 8,

// FD = 2
  1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5,
  5, 6, 6, 7, 8, 8, 9, 10, 11, 12, 13, 14, 16, 16, 16, 16,

// FD = 3
  2, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 6, 6, 7,
  8 , 8, 9, 10, 11, 12, 13, 14, 16, 17, 19, 20, 22, 22, 22, 22
};

static const unsigned char FKEY_TAB [16] =
{ 
	0, 0, 0, 0,
	0, 0, 0, 1,
	2, 3, 3, 3,
	3, 3, 3, 3
};

static const unsigned char LFO_AMS_TAB [4] =
{
	31, 4, 1, 0
};

static const unsigned char LFO_FMS_TAB [8] =
{
	LFO_FMS_BASE * 0, LFO_FMS_BASE * 1,
	LFO_FMS_BASE * 2, LFO_FMS_BASE * 3,
	LFO_FMS_BASE * 4, LFO_FMS_BASE * 6,
	LFO_FMS_BASE * 12, LFO_FMS_BASE * 24
};

inline void YM2612_Special_Update() { }

struct Ym2612_Impl
{
	enum { channel_count = Ym2612_Emu::channel_count };
	
	state_t YM2612;
	int mute_mask;
	tables_t g;
	
	void KEY_ON( channel_t&, int );
	void KEY_OFF( channel_t&, int );
	int SLOT_SET( int, int );
	int CHANNEL_SET( int, int );
	int YM_SET( int, int );
	
	void set_rate( double sample_rate, double clock_factor );
	void reset();
	void write0( int addr, int data );
	void write1( int addr, int data );
	void run_timer( int );
	void run( int pair_count, Ym2612_Emu::sample_t* );
};

void Ym2612_Impl::KEY_ON( channel_t& ch, int nsl)
{
	slot_t *SL = &(ch.SLOT [nsl]);  // on recupere le bon pointeur de slot
	
	if (SL->Ecurp == RELEASE)       // la touche est-elle rel'chee ?
	{
		SL->Fcnt = 0;

		// Fix Ecco 2 splash sound
		
		SL->Ecnt = (g.DECAY_TO_ATTACK [g.ENV_TAB [SL->Ecnt >> ENV_LBITS]] + ENV_ATTACK) & SL->ChgEnM;
		SL->ChgEnM = ~0;

//      SL->Ecnt = g.DECAY_TO_ATTACK [g.ENV_TAB [SL->Ecnt >> ENV_LBITS]] + ENV_ATTACK;
//      SL->Ecnt = 0;

		SL->Einc = SL->EincA;
		SL->Ecmp = ENV_DECAY;
		SL->Ecurp = ATTACK;
	}
}


void Ym2612_Impl::KEY_OFF(channel_t& ch, int nsl)
{
	slot_t *SL = &(ch.SLOT [nsl]);  // on recupere le bon pointeur de slot
	
	if (SL->Ecurp != RELEASE)       // la touche est-elle appuyee ?
	{
		if (SL->Ecnt < ENV_DECAY)   // attack phase ?
		{
			SL->Ecnt = (g.ENV_TAB [SL->Ecnt >> ENV_LBITS] << ENV_LBITS) + ENV_DECAY;
		}

		SL->Einc = SL->EincR;
		SL->Ecmp = ENV_END;
		SL->Ecurp = RELEASE;
	}
}


int Ym2612_Impl::SLOT_SET( int Adr, int data )
{
	int nch = Adr & 3;
	if ( nch == 3 )
		return 1;
	
	channel_t& ch = YM2612.CHANNEL [nch + (Adr & 0x100 ? 3 : 0)];
	slot_t& sl = ch.SLOT [(Adr >> 2) & 3];

	switch ( Adr & 0xF0 )
	{
		case 0x30:
			if ( (sl.MUL = (data & 0x0F)) != 0 ) sl.MUL <<= 1;
			else sl.MUL = 1;

			sl.DT = (int*) g.DT_TAB [(data >> 4) & 7];

			ch.SLOT [0].Finc = -1;

			break;

		case 0x40:
			sl.TL = data & 0x7F;

			// SOR2 do a lot of TL adjustement and this fix R.Shinobi jump sound...
			YM2612_Special_Update();

#if ((ENV_HBITS - 7) < 0)
			sl.TLL = sl.TL >> (7 - ENV_HBITS);
#else
			sl.TLL = sl.TL << (ENV_HBITS - 7);
#endif

			break;

		case 0x50:
			sl.KSR_S = 3 - (data >> 6);

			ch.SLOT [0].Finc = -1;

			if (data &= 0x1F) sl.AR = (int*) &g.AR_TAB [data << 1];
			else sl.AR = (int*) &g.NULL_RATE [0];

			sl.EincA = sl.AR [sl.KSR];
			if (sl.Ecurp == ATTACK) sl.Einc = sl.EincA;
			break;

		case 0x60:
			if ( (sl.AMSon = (data & 0x80)) != 0 ) sl.AMS = ch.AMS;
			else sl.AMS = 31;

			if (data &= 0x1F) sl.DR = (int*) &g.DR_TAB [data << 1];
			else sl.DR = (int*) &g.NULL_RATE [0];

			sl.EincD = sl.DR [sl.KSR];
			if (sl.Ecurp == DECAY) sl.Einc = sl.EincD;
			break;

		case 0x70:
			if (data &= 0x1F) sl.SR = (int*) &g.DR_TAB [data << 1];
			else sl.SR = (int*) &g.NULL_RATE [0];

			sl.EincS = sl.SR [sl.KSR];
			if ((sl.Ecurp == SUBSTAIN) && (sl.Ecnt < ENV_END)) sl.Einc = sl.EincS;
			break;

		case 0x80:
			sl.SLL = g.SL_TAB [data >> 4];

			sl.RR = (int*) &g.DR_TAB [((data & 0xF) << 2) + 2];

			sl.EincR = sl.RR [sl.KSR];
			if ((sl.Ecurp == RELEASE) && (sl.Ecnt < ENV_END)) sl.Einc = sl.EincR;
			break;

		case 0x90:
			// SSG-EG envelope shapes :
			/*
			   E  At Al H
			  
			   1  0  0  0  \\\\
			   1  0  0  1  \___
			   1  0  1  0  \/\/
			   1  0  1  1  \
			   1  1  0  0  ////
			   1  1  0  1  /
			   1  1  1  0  /\/\
			   1  1  1  1  /___
			  
			   E  = SSG-EG enable
			   At = Start negate
			   Al = Altern
			   H  = Hold */

			set_seg( sl, (data & 8) ? (data & 0x0F) : 0 );
			break;
	}

	return 0;
}


int Ym2612_Impl::CHANNEL_SET( int Adr, int data )
{
	int num = Adr & 3;
	if ( num == 3 )
		return 1;
	
	channel_t& ch = YM2612.CHANNEL [num + (Adr & 0x100 ? 3 : 0)];
	
	switch ( Adr & 0xFC )
	{
		case 0xA0:
			YM2612_Special_Update();

			ch.FNUM [0] = (ch.FNUM [0] & 0x700) + data;
			ch.KC [0] = (ch.FOCT [0] << 2) | FKEY_TAB [ch.FNUM [0] >> 7];

			ch.SLOT [0].Finc = -1;
			break;

		case 0xA4:
			YM2612_Special_Update();

			ch.FNUM [0] = (ch.FNUM [0] & 0x0FF) + ((data & 0x07) << 8);
			ch.FOCT [0] = (data & 0x38) >> 3;
			ch.KC [0] = (ch.FOCT [0] << 2) | FKEY_TAB [ch.FNUM [0] >> 7];

			ch.SLOT [0].Finc = -1;
			break;

		case 0xA8:
			if ( Adr < 0x100 )
			{
				num++;

				YM2612_Special_Update();

				YM2612.CHANNEL [2].FNUM [num] = (YM2612.CHANNEL [2].FNUM [num] & 0x700) + data;
				YM2612.CHANNEL [2].KC [num] = (YM2612.CHANNEL [2].FOCT [num] << 2) |
						FKEY_TAB [YM2612.CHANNEL [2].FNUM [num] >> 7];

				YM2612.CHANNEL [2].SLOT [0].Finc = -1;
			}
			break;

		case 0xAC:
			if ( Adr < 0x100 )
			{
				num++;

				YM2612_Special_Update();

				YM2612.CHANNEL [2].FNUM [num] = (YM2612.CHANNEL [2].FNUM [num] & 0x0FF) + ((data & 0x07) << 8);
				YM2612.CHANNEL [2].FOCT [num] = (data & 0x38) >> 3;
				YM2612.CHANNEL [2].KC [num] = (YM2612.CHANNEL [2].FOCT [num] << 2) |
						FKEY_TAB [YM2612.CHANNEL [2].FNUM [num] >> 7];

				YM2612.CHANNEL [2].SLOT [0].Finc = -1;
			}
			break;

		case 0xB0:
			if ( ch.ALGO != (data & 7) )
			{
				// Fix VectorMan 2 heli sound (level 1)
				YM2612_Special_Update();

				ch.ALGO = data & 7;
				
				ch.SLOT [0].ChgEnM = 0;
				ch.SLOT [1].ChgEnM = 0;
				ch.SLOT [2].ChgEnM = 0;
				ch.SLOT [3].ChgEnM = 0;
			}

			ch.FB = 9 - ((data >> 3) & 7);                              // Real thing ?

//          if (ch.FB = ((data >> 3) & 7)) ch.FB = 9 - ch.FB;       // Thunder force 4 (music stage 8), Gynoug, Aladdin bug sound...
//          else ch.FB = 31;
			break;

		case 0xB4: {
			YM2612_Special_Update();
			
			ch.LEFT = 0 - ((data >> 7) & 1);
			ch.RIGHT = 0 - ((data >> 6) & 1);
			
			ch.AMS = LFO_AMS_TAB [(data >> 4) & 3];
			ch.FMS = LFO_FMS_TAB [data & 7];
			
			for ( int i = 0; i < 4; i++ )
			{
				slot_t& sl = ch.SLOT [i];
				sl.AMS = (sl.AMSon ? ch.AMS : 31);
			}
			break;
		}
	}
	
	return 0;
}


int Ym2612_Impl::YM_SET(int Adr, int data)
{
	switch ( Adr )
	{
		case 0x22:
			if (data & 8) // LFO enable
			{
				// Cool Spot music 1, LFO modified severals time which
				// distord the sound, have to check that on a real genesis...

				g.LFOinc = g.LFO_INC_TAB [data & 7];
			}
			else
			{
				g.LFOinc = g.LFOcnt = 0;
			}
			break;

		case 0x24:
			YM2612.TimerA = (YM2612.TimerA & 0x003) | (((int) data) << 2);

			if (YM2612.TimerAL != (1024 - YM2612.TimerA) << 12)
			{
				YM2612.TimerAcnt = YM2612.TimerAL = (1024 - YM2612.TimerA) << 12;
			}
			break;

		case 0x25:
			YM2612.TimerA = (YM2612.TimerA & 0x3FC) | (data & 3);

			if (YM2612.TimerAL != (1024 - YM2612.TimerA) << 12)
			{
				YM2612.TimerAcnt = YM2612.TimerAL = (1024 - YM2612.TimerA) << 12;
			}
			break;

		case 0x26:
			YM2612.TimerB = data;

			if (YM2612.TimerBL != (256 - YM2612.TimerB) << (4 + 12))
			{
				YM2612.TimerBcnt = YM2612.TimerBL = (256 - YM2612.TimerB) << (4 + 12);
			}
			break;

		case 0x27:
			// Parametre divers
			// b7 = CSM MODE
			// b6 = 3 slot mode
			// b5 = reset b
			// b4 = reset a
			// b3 = timer enable b
			// b2 = timer enable a
			// b1 = load b
			// b0 = load a

			if ((data ^ YM2612.Mode) & 0x40)
			{
				// We changed the channel 2 mode, so recalculate phase step
				// This fix the punch sound in Street of Rage 2

				YM2612_Special_Update();

				YM2612.CHANNEL [2].SLOT [0].Finc = -1;      // recalculate phase step
			}

//          if ((data & 2) && (YM2612.Status & 2)) YM2612.TimerBcnt = YM2612.TimerBL;
//          if ((data & 1) && (YM2612.Status & 1)) YM2612.TimerAcnt = YM2612.TimerAL;

//          YM2612.Status &= (~data >> 4);                  // Reset du Status au cas ou c'est demande
			YM2612.Status &= (~data >> 4) & (data >> 2);    // Reset Status

			YM2612.Mode = data;
			break;

		case 0x28: {
			int nch = data & 3;
			if ( nch == 3 )
				return 1;
			if ( data & 4 )
				nch += 3;
			channel_t& ch = YM2612.CHANNEL [nch];

			YM2612_Special_Update();

			if (data & 0x10) KEY_ON(ch, S0);    // On appuie sur la touche pour le slot 1
			else KEY_OFF(ch, S0);               // On rel'che la touche pour le slot 1
			if (data & 0x20) KEY_ON(ch, S1);    // On appuie sur la touche pour le slot 3
			else KEY_OFF(ch, S1);               // On rel'che la touche pour le slot 3
			if (data & 0x40) KEY_ON(ch, S2);    // On appuie sur la touche pour le slot 2
			else KEY_OFF(ch, S2);               // On rel'che la touche pour le slot 2
			if (data & 0x80) KEY_ON(ch, S3);    // On appuie sur la touche pour le slot 4
			else KEY_OFF(ch, S3);               // On rel'che la touche pour le slot 4
			break;
		}
		
		case 0x2B:
			if (YM2612.DAC ^ (data & 0x80)) YM2612_Special_Update();

			YM2612.DAC = data & 0x80;   // activation/desactivation du DAC
			break;
	}
	
	return 0;
}

void Ym2612_Impl::set_rate( double sample_rate, double clock_rate )
{
	assert( sample_rate );
	assert( clock_rate > sample_rate );
	
	int i;

	// 144 = 12 * (prescale * 2) = 12 * 6 * 2
	// prescale set to 6 by default
	
	double Frequence = clock_rate / sample_rate / 144.0;
	if ( fabs( Frequence - 1.0 ) < 0.0000001 )
		Frequence = 1.0;
	YM2612.TimerBase = int (Frequence * 4096.0);

	// Tableau TL :
	// [0     -  4095] = +output  [4095  - ...] = +output overflow (fill with 0)
	// [12288 - 16383] = -output  [16384 - ...] = -output overflow (fill with 0)

	for(i = 0; i < TL_LENGHT; i++)
	{
		if (i >= PG_CUT_OFF)    // YM2612 cut off sound after 78 dB (14 bits output ?)
		{
			g.TL_TAB [TL_LENGHT + i] = g.TL_TAB [i] = 0;
		}
		else
		{
			double x = MAX_OUT;                         // Max output
			x /= pow( 10.0, (ENV_STEP * i) / 20.0 );    // Decibel -> Voltage

			g.TL_TAB [i] = (int) x;
			g.TL_TAB [TL_LENGHT + i] = -g.TL_TAB [i];
		}
	}
	
	// Tableau SIN :
	// g.SIN_TAB [x] [y] = sin(x) * y; 
	// x = phase and y = volume

	g.SIN_TAB [0] = g.SIN_TAB [SIN_LENGHT / 2] = PG_CUT_OFF;

	for(i = 1; i <= SIN_LENGHT / 4; i++)
	{
		double x = sin(2.0 * PI * (double) (i) / (double) (SIN_LENGHT));    // Sinus
		x = 20 * log10(1 / x);                                      // convert to dB

		int j = (int) (x / ENV_STEP);                       // Get TL range

		if (j > PG_CUT_OFF) j = (int) PG_CUT_OFF;

		g.SIN_TAB [i] = g.SIN_TAB [(SIN_LENGHT / 2) - i] = j;
		g.SIN_TAB [(SIN_LENGHT / 2) + i] = g.SIN_TAB [SIN_LENGHT - i] = TL_LENGHT + j;
	}

	// Tableau LFO (LFO wav) :

	for(i = 0; i < LFO_LENGHT; i++)
	{
		double x = sin(2.0 * PI * (double) (i) / (double) (LFO_LENGHT));    // Sinus
		x += 1.0;
		x /= 2.0;                   // positive only
		x *= 11.8 / ENV_STEP;       // ajusted to MAX enveloppe modulation

		g.LFO_ENV_TAB [i] = (int) x;

		x = sin(2.0 * PI * (double) (i) / (double) (LFO_LENGHT));   // Sinus
		x *= (double) ((1 << (LFO_HBITS - 1)) - 1);

		g.LFO_FREQ_TAB [i] = (int) x;

	}

	// Tableau Enveloppe :
	// g.ENV_TAB [0] -> g.ENV_TAB [ENV_LENGHT - 1]              = attack curve
	// g.ENV_TAB [ENV_LENGHT] -> g.ENV_TAB [2 * ENV_LENGHT - 1] = decay curve

	for(i = 0; i < ENV_LENGHT; i++)
	{
		// Attack curve (x^8 - music level 2 Vectorman 2)
		double x = pow(((double) ((ENV_LENGHT - 1) - i) / (double) (ENV_LENGHT)), 8);
		x *= ENV_LENGHT;

		g.ENV_TAB [i] = (int) x;

		// Decay curve (just linear)
		x = pow(((double) (i) / (double) (ENV_LENGHT)), 1);
		x *= ENV_LENGHT;

		g.ENV_TAB [ENV_LENGHT + i] = (int) x;
	}
	for ( i = 0; i < 8; i++ )
		g.ENV_TAB [i + ENV_LENGHT * 2] = 0;
	
	g.ENV_TAB [ENV_END >> ENV_LBITS] = ENV_LENGHT - 1;      // for the stopped state
	
	// Tableau pour la conversion Attack -> Decay and Decay -> Attack
	
	int j = ENV_LENGHT - 1;
	for ( i = 0; i < ENV_LENGHT; i++ )
	{
		while ( j && g.ENV_TAB [j] < i )
			j--;

		g.DECAY_TO_ATTACK [i] = j << ENV_LBITS;
	}

	// Tableau pour le Substain Level
	
	for(i = 0; i < 15; i++)
	{
		double x = i * 3;           // 3 and not 6 (Mickey Mania first music for test)
		x /= ENV_STEP;

		g.SL_TAB [i] = ((int) x << ENV_LBITS) + ENV_DECAY;
	}

	g.SL_TAB [15] = ((ENV_LENGHT - 1) << ENV_LBITS) + ENV_DECAY; // special case : volume off

	// Tableau Frequency Step

	for(i = 0; i < 2048; i++)
	{
		double x = (double) (i) * Frequence;

#if ((SIN_LBITS + SIN_HBITS - (21 - 7)) < 0)
		x /= (double) (1 << ((21 - 7) - SIN_LBITS - SIN_HBITS));
#else
		x *= (double) (1 << (SIN_LBITS + SIN_HBITS - (21 - 7)));
#endif

		x /= 2.0;   // because MUL = value * 2

		g.FINC_TAB [i] = (unsigned int) x;
	}

	// Tableaux Attack & Decay Rate

	for(i = 0; i < 4; i++)
	{
		g.AR_TAB [i] = 0;
		g.DR_TAB [i] = 0;
	}
	
	for(i = 0; i < 60; i++)
	{
		double x = Frequence;

		x *= 1.0 + ((i & 3) * 0.25);                    // bits 0-1 : x1.00, x1.25, x1.50, x1.75
		x *= (double) (1 << ((i >> 2)));                // bits 2-5 : shift bits (x2^0 - x2^15)
		x *= (double) (ENV_LENGHT << ENV_LBITS);        // on ajuste pour le tableau g.ENV_TAB

		g.AR_TAB [i + 4] = (unsigned int) (x / AR_RATE);
		g.DR_TAB [i + 4] = (unsigned int) (x / DR_RATE);
	}

	for(i = 64; i < 96; i++)
	{
		g.AR_TAB [i] = g.AR_TAB [63];
		g.DR_TAB [i] = g.DR_TAB [63];

		g.NULL_RATE [i - 64] = 0;
	}
	
	for ( i = 96; i < 128; i++ )
		g.AR_TAB [i] = 0;
	
	// Tableau Detune

	for(i = 0; i < 4; i++)
	{
		for (int j = 0; j < 32; j++)
		{
#if ((SIN_LBITS + SIN_HBITS - 21) < 0)
			double y = (double) DT_DEF_TAB [(i << 5) + j] * Frequence / (double) (1 << (21 - SIN_LBITS - SIN_HBITS));
#else
			double y = (double) DT_DEF_TAB [(i << 5) + j] * Frequence * (double) (1 << (SIN_LBITS + SIN_HBITS - 21));
#endif

			g.DT_TAB [i + 0] [j] = (int)  y;
			g.DT_TAB [i + 4] [j] = (int) -y;
		}
	}
	
	// Tableau LFO
	g.LFO_INC_TAB [0] = (unsigned int) (3.98 * (double) (1 << (LFO_HBITS + LFO_LBITS)) / sample_rate);
	g.LFO_INC_TAB [1] = (unsigned int) (5.56 * (double) (1 << (LFO_HBITS + LFO_LBITS)) / sample_rate);
	g.LFO_INC_TAB [2] = (unsigned int) (6.02 * (double) (1 << (LFO_HBITS + LFO_LBITS)) / sample_rate);
	g.LFO_INC_TAB [3] = (unsigned int) (6.37 * (double) (1 << (LFO_HBITS + LFO_LBITS)) / sample_rate);
	g.LFO_INC_TAB [4] = (unsigned int) (6.88 * (double) (1 << (LFO_HBITS + LFO_LBITS)) / sample_rate);
	g.LFO_INC_TAB [5] = (unsigned int) (9.63 * (double) (1 << (LFO_HBITS + LFO_LBITS)) / sample_rate);
	g.LFO_INC_TAB [6] = (unsigned int) (48.1 * (double) (1 << (LFO_HBITS + LFO_LBITS)) / sample_rate);
	g.LFO_INC_TAB [7] = (unsigned int) (72.2 * (double) (1 << (LFO_HBITS + LFO_LBITS)) / sample_rate);
	
	reset();
}

const char* Ym2612_Emu::set_rate( double sample_rate, double clock_rate )
{
	if ( !impl )
	{
		impl = (Ym2612_Impl*) malloc( sizeof *impl );
		if ( !impl )
			return "Out of memory";
		impl->mute_mask = 0;
	}
	memset( &impl->YM2612, 0, sizeof impl->YM2612 );
	
	impl->set_rate( sample_rate, clock_rate );
	
	return 0;
}

Ym2612_Emu::~Ym2612_Emu()
{
	free( impl );
}

inline void Ym2612_Impl::write0( int opn_addr, int data )
{
	assert( (unsigned) data <= 0xFF );
	
	if ( opn_addr < 0x30 )
	{
		YM2612.REG [0] [opn_addr] = data;
		YM_SET( opn_addr, data );
	}
	else if ( YM2612.REG [0] [opn_addr] != data )
	{
		YM2612.REG [0] [opn_addr] = data;
		
		if ( opn_addr < 0xA0 )
			SLOT_SET( opn_addr, data );
		else
			CHANNEL_SET( opn_addr, data );
	}
}

inline void Ym2612_Impl::write1( int opn_addr, int data )
{
	assert( (unsigned) data <= 0xFF );
	
	if ( opn_addr >= 0x30 && YM2612.REG [1] [opn_addr] != data )
	{
		YM2612.REG [1] [opn_addr] = data;

		if ( opn_addr < 0xA0 )
			SLOT_SET( opn_addr + 0x100, data );
		else
			CHANNEL_SET( opn_addr + 0x100, data );
	}
}

void Ym2612_Emu::reset()
{
	impl->reset();
}

void Ym2612_Impl::reset()
{
	g.LFOcnt = 0;
	YM2612.TimerA = 0;
	YM2612.TimerAL = 0;
	YM2612.TimerAcnt = 0;
	YM2612.TimerB = 0;
	YM2612.TimerBL = 0;
	YM2612.TimerBcnt = 0;
	YM2612.DAC = 0;

	YM2612.Status = 0;

	int i;
	for ( i = 0; i < channel_count; i++ )
	{
		channel_t& ch = YM2612.CHANNEL [i];
		
		ch.LEFT = ~0;
		ch.RIGHT = ~0;
		ch.ALGO = 0;
		ch.FB = 31;
		ch.FMS = 0;
		ch.AMS = 0;

		for ( int j = 0 ;j < 4 ; j++ )
		{
			ch.S0_OUT [j] = 0;
			ch.FNUM [j] = 0;
			ch.FOCT [j] = 0;
			ch.KC [j] = 0;

			ch.SLOT [j].Fcnt = 0;
			ch.SLOT [j].Finc = 0;
			ch.SLOT [j].Ecnt = ENV_END;     // Put it at the end of Decay phase...
			ch.SLOT [j].Einc = 0;
			ch.SLOT [j].Ecmp = 0;
			ch.SLOT [j].Ecurp = RELEASE;

			ch.SLOT [j].ChgEnM = 0;
		}
	}

	for ( i = 0; i < 0x100; i++ )
	{
		YM2612.REG [0] [i] = -1;
		YM2612.REG [1] [i] = -1;
	}

	for ( i = 0xB6; i >= 0xB4; i-- )
	{
		write0( i, 0xC0 );
		write1( i, 0xC0 );
	}

	for ( i = 0xB2; i >= 0x22; i-- )
	{
		write0( i, 0 );
		write1( i, 0 );
	}
	
	write0( 0x2A, 0x80 );
}

void Ym2612_Emu::write0( int addr, int data )
{
	impl->write0( addr, data );
}

void Ym2612_Emu::write1( int addr, int data )
{
	impl->write1( addr, data );
}

void Ym2612_Emu::mute_voices( int mask ) { impl->mute_mask = mask; }

static void update_envelope_( slot_t* sl )
{
	switch ( sl->Ecurp )
	{
	case 0:
		// Env_Attack_Next
		
		// Verified with Gynoug even in HQ (explode SFX)
		sl->Ecnt = ENV_DECAY;

		sl->Einc = sl->EincD;
		sl->Ecmp = sl->SLL;
		sl->Ecurp = DECAY;
		break;
	
	case 1:
		// Env_Decay_Next
		
		// Verified with Gynoug even in HQ (explode SFX)
		sl->Ecnt = sl->SLL;

		sl->Einc = sl->EincS;
		sl->Ecmp = ENV_END;
		sl->Ecurp = SUBSTAIN;
		break;
	
	case 2:
		// Env_Substain_Next(slot_t *SL)
		if (sl->SEG & 8)    // SSG envelope type
		{
			int release = sl->SEG & 1;
			
			if ( !release )
			{
				// re KEY ON

				// sl->Fcnt = 0;
				// sl->ChgEnM = ~0;

				sl->Ecnt = 0;
				sl->Einc = sl->EincA;
				sl->Ecmp = ENV_DECAY;
				sl->Ecurp = ATTACK;
			}

			set_seg( *sl, (sl->SEG << 1) & 4 );
			
			if ( !release )
				break;
		}
		// fall through
	
	case 3:
		// Env_Release_Next
		sl->Ecnt = ENV_END;
		sl->Einc = 0;
		sl->Ecmp = ENV_END + 1;
		break;
	
	// default: no op
	}
}

inline void update_envelope( slot_t& sl )
{
	int ecmp = sl.Ecmp;
	if ( (sl.Ecnt += sl.Einc) >= ecmp )
		update_envelope_( &sl );
}

template<int algo>
struct ym2612_update_chan {
	static void func( tables_t&, channel_t&, Ym2612_Emu::sample_t*, int );
};

typedef void (*ym2612_update_chan_t)( tables_t&, channel_t&, Ym2612_Emu::sample_t*, int );

template<int algo>
void ym2612_update_chan<algo>::func( tables_t& g, channel_t& ch,
		Ym2612_Emu::sample_t* buf, int length )
{
	int not_end = ch.SLOT [S3].Ecnt - ENV_END;
	
	// algo is a compile-time constant, so all conditions based on it are resolved
	// during compilation
	
	// special cases
	if ( algo == 7 )
		not_end |= ch.SLOT [S0].Ecnt - ENV_END;
	
	if ( algo >= 5 )
		not_end |= ch.SLOT [S2].Ecnt - ENV_END;
	
	if ( algo >= 4 )
		not_end |= ch.SLOT [S1].Ecnt - ENV_END;
	
	int CH_S0_OUT_1 = ch.S0_OUT [1];
	
	int in0 = ch.SLOT [S0].Fcnt;
	int in1 = ch.SLOT [S1].Fcnt;
	int in2 = ch.SLOT [S2].Fcnt;
	int in3 = ch.SLOT [S3].Fcnt;
	
	int YM2612_LFOinc = g.LFOinc;
	int YM2612_LFOcnt = g.LFOcnt + YM2612_LFOinc;
	
	if ( !not_end )
		return;
	
	do
	{
		// envelope
		int const env_LFO = g.LFO_ENV_TAB [YM2612_LFOcnt >> LFO_LBITS & LFO_MASK];
		
		short const* const ENV_TAB = g.ENV_TAB;
		
	#define CALC_EN( x ) \
		int temp##x = ENV_TAB [ch.SLOT [S##x].Ecnt >> ENV_LBITS] + ch.SLOT [S##x].TLL;  \
		int en##x = ((temp##x ^ ch.SLOT [S##x].env_xor) + (env_LFO >> ch.SLOT [S##x].AMS)) &    \
				((temp##x - ch.SLOT [S##x].env_max) >> 31);
		
		CALC_EN( 0 )
		CALC_EN( 1 )
		CALC_EN( 2 )
		CALC_EN( 3 )
		
		int const* const TL_TAB = g.TL_TAB;
		
	#define SINT( i, o ) (TL_TAB [g.SIN_TAB [(i)] + (o)])
		
		// feedback
		int CH_S0_OUT_0 = ch.S0_OUT [0];
		{
			int temp = in0 + ((CH_S0_OUT_0 + CH_S0_OUT_1) >> ch.FB);
			CH_S0_OUT_1 = CH_S0_OUT_0;
			CH_S0_OUT_0 = SINT( (temp >> SIN_LBITS) & SIN_MASK, en0 );
		}
		
		int CH_OUTd;
		if ( algo == 0 )
		{
			int temp = in1 + CH_S0_OUT_1;
			temp = in2 + SINT( (temp >> SIN_LBITS) & SIN_MASK, en1 );
			temp = in3 + SINT( (temp >> SIN_LBITS) & SIN_MASK, en2 );
			CH_OUTd = SINT( (temp >> SIN_LBITS) & SIN_MASK, en3 );
		}
		else if ( algo == 1 )
		{
			int temp = in2 + CH_S0_OUT_1 + SINT( (in1 >> SIN_LBITS) & SIN_MASK, en1 );
			temp = in3 + SINT( (temp >> SIN_LBITS) & SIN_MASK, en2 );
			CH_OUTd = SINT( (temp >> SIN_LBITS) & SIN_MASK, en3 );
		}
		else if ( algo == 2 )
		{
			int temp = in2 + SINT( (in1 >> SIN_LBITS) & SIN_MASK, en1 );
			temp = in3 + CH_S0_OUT_1 + SINT( (temp >> SIN_LBITS) & SIN_MASK, en2 );
			CH_OUTd = SINT( (temp >> SIN_LBITS) & SIN_MASK, en3 );
		}
		else if ( algo == 3 )
		{
			int temp = in1 + CH_S0_OUT_1;
			temp = in3 + SINT( (temp >> SIN_LBITS) & SIN_MASK, en1 ) +
					SINT( (in2 >> SIN_LBITS) & SIN_MASK, en2 );
			CH_OUTd = SINT( (temp >> SIN_LBITS) & SIN_MASK, en3 );
		}
		else if ( algo == 4 )
		{
			int temp = in3 + SINT( (in2 >> SIN_LBITS) & SIN_MASK, en2 );
			CH_OUTd = SINT( (temp >> SIN_LBITS) & SIN_MASK, en3 ) +
					SINT( ((in1 + CH_S0_OUT_1) >> SIN_LBITS) & SIN_MASK, en1 );
			//DO_LIMIT
		}
		else if ( algo == 5 )
		{
			int temp = CH_S0_OUT_1;
			CH_OUTd = SINT( ((in3 + temp) >> SIN_LBITS) & SIN_MASK, en3 ) +
					SINT( ((in1 + temp) >> SIN_LBITS) & SIN_MASK, en1 ) +
					SINT( ((in2 + temp) >> SIN_LBITS) & SIN_MASK, en2 );
			//DO_LIMIT
		}
		else if ( algo == 6 )
		{
			CH_OUTd = SINT( (in3 >> SIN_LBITS) & SIN_MASK, en3 ) +
					SINT( ((in1 + CH_S0_OUT_1) >> SIN_LBITS) & SIN_MASK, en1 ) +
					SINT( (in2 >> SIN_LBITS) & SIN_MASK, en2 );
			//DO_LIMIT
		}
		else if ( algo == 7 )
		{
			CH_OUTd = SINT( (in3 >> SIN_LBITS) & SIN_MASK, en3 ) +
					SINT( (in1 >> SIN_LBITS) & SIN_MASK, en1 ) +
					SINT( (in2 >> SIN_LBITS) & SIN_MASK, en2 ) + CH_S0_OUT_1;
			//DO_LIMIT
		}
		
		CH_OUTd >>= MAX_OUT_BITS - output_bits + 2;
		
		// update phase
		unsigned freq_LFO = ((g.LFO_FREQ_TAB [YM2612_LFOcnt >> LFO_LBITS & LFO_MASK] *
				ch.FMS) >> (LFO_HBITS - 1 + 1)) + (1L << (LFO_FMS_LBITS - 1));
		YM2612_LFOcnt += YM2612_LFOinc;
		in0 += (ch.SLOT [S0].Finc * freq_LFO) >> (LFO_FMS_LBITS - 1);
		in1 += (ch.SLOT [S1].Finc * freq_LFO) >> (LFO_FMS_LBITS - 1);
		in2 += (ch.SLOT [S2].Finc * freq_LFO) >> (LFO_FMS_LBITS - 1);
		in3 += (ch.SLOT [S3].Finc * freq_LFO) >> (LFO_FMS_LBITS - 1);
		
		int t0 = buf [0] + (CH_OUTd & ch.LEFT);
		int t1 = buf [1] + (CH_OUTd & ch.RIGHT);
		
		update_envelope( ch.SLOT [0] );
		update_envelope( ch.SLOT [1] );
		update_envelope( ch.SLOT [2] );
		update_envelope( ch.SLOT [3] );
		
		ch.S0_OUT [0] = CH_S0_OUT_0;
		buf [0] = t0;
		buf [1] = t1;
		buf += 2;
	}
	while ( --length );
	
	ch.S0_OUT [1] = CH_S0_OUT_1;
	
	ch.SLOT [S0].Fcnt = in0;
	ch.SLOT [S1].Fcnt = in1;
	ch.SLOT [S2].Fcnt = in2;
	ch.SLOT [S3].Fcnt = in3;
}

static const ym2612_update_chan_t UPDATE_CHAN [8] = {
	&ym2612_update_chan<0>::func,
	&ym2612_update_chan<1>::func,
	&ym2612_update_chan<2>::func,
	&ym2612_update_chan<3>::func,
	&ym2612_update_chan<4>::func,
	&ym2612_update_chan<5>::func,
	&ym2612_update_chan<6>::func,
	&ym2612_update_chan<7>::func
};

void Ym2612_Impl::run_timer( int length )
{
	int const step = 6;
	int remain = length;
	do
	{
		int n = step;
		if ( n > remain )
			n = remain;
		remain -= n;
		
		long i = n * YM2612.TimerBase;
		if (YM2612.Mode & 1)                            // Timer A ON ?
		{
	//      if ((YM2612.TimerAcnt -= 14073) <= 0)       // 13879=NTSC (old: 14475=NTSC  14586=PAL)
			if ((YM2612.TimerAcnt -= i) <= 0)
			{
				// timer a overflow
				
				YM2612.Status |= (YM2612.Mode & 0x04) >> 2;
				YM2612.TimerAcnt += YM2612.TimerAL;

				if (YM2612.Mode & 0x80)
				{
					KEY_ON( YM2612.CHANNEL [2], 0 );
					KEY_ON( YM2612.CHANNEL [2], 1 );
					KEY_ON( YM2612.CHANNEL [2], 2 );
					KEY_ON( YM2612.CHANNEL [2], 3 );
				}
			}
		}

		if (YM2612.Mode & 2)                            // Timer B ON ?
		{
	//      if ((YM2612.TimerBcnt -= 14073) <= 0)       // 13879=NTSC (old: 14475=NTSC  14586=PAL)
			if ((YM2612.TimerBcnt -= i) <= 0)
			{
				// timer b overflow
				YM2612.Status |= (YM2612.Mode & 0x08) >> 2;
				YM2612.TimerBcnt += YM2612.TimerBL;
			}
		}
	}
	while ( remain > 0 );
}

void Ym2612_Impl::run( int pair_count, Ym2612_Emu::sample_t* out )
{
	if ( pair_count <= 0 )
		return;
	
	if ( YM2612.Mode & 3 )
		run_timer( pair_count );
	
	// Mise à jour des pas des compteurs-frequences s'ils ont ete modifies
	
	for ( int chi = 0; chi < channel_count; chi++ )
	{
		channel_t& ch = YM2612.CHANNEL [chi];
		if ( ch.SLOT [0].Finc != -1 )
			continue;
		
		int i2 = 0;
		if ( chi == 2 && (YM2612.Mode & 0x40) )
			i2 = 2;
		
		for ( int i = 0; i < 4; i++ )
		{
			// static int seq [4] = { 2, 1, 3, 0 };
			// if ( i2 ) i2 = seq [i];
			
			slot_t& sl = ch.SLOT [i];
			int finc = g.FINC_TAB [ch.FNUM [i2]] >> (7 - ch.FOCT [i2]);
			int ksr = ch.KC [i2] >> sl.KSR_S;   // keycode attenuation
			sl.Finc = (finc + sl.DT [ch.KC [i2]]) * sl.MUL;
			if (sl.KSR != ksr)          // si le KSR a change alors
			{                       // les differents taux pour l'enveloppe sont mis à jour
				sl.KSR = ksr;

				sl.EincA = sl.AR [ksr];
				sl.EincD = sl.DR [ksr];
				sl.EincS = sl.SR [ksr];
				sl.EincR = sl.RR [ksr];

				if (sl.Ecurp == ATTACK)
				{
					sl.Einc = sl.EincA;
				}
				else if (sl.Ecurp == DECAY)
				{
					sl.Einc = sl.EincD;
				}
				else if (sl.Ecnt < ENV_END)
				{
					if (sl.Ecurp == SUBSTAIN)
						sl.Einc = sl.EincS;
					else if (sl.Ecurp == RELEASE)
						sl.Einc = sl.EincR;
				}
			}
			
			if ( i2 )
				i2 = (i2 ^ 2) ^ (i2 >> 1);
		}
	}
	
	for ( int i = 0; i < channel_count; i++ )
	{
		if ( !(mute_mask & (1 << i)) && (i != 5 || !YM2612.DAC) )
			UPDATE_CHAN [YM2612.CHANNEL [i].ALGO]( g, YM2612.CHANNEL [i], out, pair_count );
	}
	
	g.LFOcnt += g.LFOinc * pair_count;
}

void Ym2612_Emu::run( int pair_count, sample_t* out ) { impl->run( pair_count, out ); }