-
Notifications
You must be signed in to change notification settings - Fork 1
/
opl.c
1462 lines (1281 loc) · 46.3 KB
/
opl.c
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
/*
* Copyright (C) 2002-2020 The DOSBox Team
* OPL2/OPL3 emulation library
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* Originally based on ADLIBEMU.C, an AdLib/OPL2 emulation library by Ken Silverman
* Copyright (C) 1998-2001 Ken Silverman
* Ken Silverman's official web site: "http://www.advsys.net/ken"
*/
#include <math.h>
#include <stdlib.h> // rand()
#include <string.h> // memset()
#include "opl.h"
static fltype recipsamp; // inverse of sampling rate
static Bit16s wavtable[WAVEPREC*3]; // wave form table
// vibrato/tremolo tables
static Bit32s vib_table[VIBTAB_SIZE];
static Bit32s trem_table[TREMTAB_SIZE*2];
static Bit32s vibval_const[BLOCKBUF_SIZE];
static Bit32s tremval_const[BLOCKBUF_SIZE];
// vibrato value tables (used per-operator)
static Bit32s vibval_var1[BLOCKBUF_SIZE];
static Bit32s vibval_var2[BLOCKBUF_SIZE];
//static Bit32s vibval_var3[BLOCKBUF_SIZE];
//static Bit32s vibval_var4[BLOCKBUF_SIZE];
// vibrato/trmolo value table pointers
static Bit32s *vibval1, *vibval2, *vibval3, *vibval4;
static Bit32s *tremval1, *tremval2, *tremval3, *tremval4;
// key scale level lookup table
static const fltype kslmul[4] = {
0.0, 0.5, 0.25, 1.0 // -> 0, 3, 1.5, 6 dB/oct
};
// frequency multiplicator lookup table
static const fltype frqmul_tab[16] = {
0.5,1,2,3,4,5,6,7,8,9,10,10,12,12,15,15
};
// calculated frequency multiplication values (depend on sampling rate)
static fltype frqmul[16];
// key scale levels
static Bit8u kslev[8][16];
// map a channel number to the register offset of the modulator (=register base)
static const Bit8u modulatorbase[9] = {
0,1,2,
8,9,10,
16,17,18
};
// map a register base to a modulator operator number or operator number
#if defined(OPLTYPE_IS_OPL3)
static const Bit8u regbase2modop[44] = {
0,1,2,0,1,2,0,0,3,4,5,3,4,5,0,0,6,7,8,6,7,8, // first set
18,19,20,18,19,20,0,0,21,22,23,21,22,23,0,0,24,25,26,24,25,26 // second set
};
static const Bit8u regbase2op[44] = {
0,1,2,9,10,11,0,0,3,4,5,12,13,14,0,0,6,7,8,15,16,17, // first set
18,19,20,27,28,29,0,0,21,22,23,30,31,32,0,0,24,25,26,33,34,35 // second set
};
#else
static const Bit8u regbase2modop[22] = {
0,1,2,0,1,2,0,0,3,4,5,3,4,5,0,0,6,7,8,6,7,8
};
static const Bit8u regbase2op[22] = {
0,1,2,9,10,11,0,0,3,4,5,12,13,14,0,0,6,7,8,15,16,17
};
#endif
// start of the waveform
static Bit32u waveform[8] = {
WAVEPREC,
WAVEPREC>>1,
WAVEPREC,
(WAVEPREC*3)>>2,
0,
0,
(WAVEPREC*5)>>2,
WAVEPREC<<1
};
// length of the waveform as mask
static Bit32u wavemask[8] = {
WAVEPREC-1,
WAVEPREC-1,
(WAVEPREC>>1)-1,
(WAVEPREC>>1)-1,
WAVEPREC-1,
((WAVEPREC*3)>>2)-1,
WAVEPREC>>1,
WAVEPREC-1
};
// where the first entry resides
static Bit32u wavestart[8] = {
0,
WAVEPREC>>1,
0,
WAVEPREC>>2,
0,
0,
0,
WAVEPREC>>3
};
// envelope generator function constants
static fltype attackconst[4] = {
(fltype)(1/2.82624),
(fltype)(1/2.25280),
(fltype)(1/1.88416),
(fltype)(1/1.59744)
};
static fltype decrelconst[4] = {
(fltype)(1/39.28064),
(fltype)(1/31.41608),
(fltype)(1/26.17344),
(fltype)(1/22.44608)
};
void operator_advance(op_type* op_pt, Bit32s vib) {
op_pt->wfpos = op_pt->tcount; // waveform position
// advance waveform time
op_pt->tcount += op_pt->tinc;
op_pt->tcount += (Bit32s)(op_pt->tinc)*vib/FIXEDPT;
op_pt->generator_pos += generator_add;
}
void operator_advance_drums(op_type* op_pt1, Bit32s vib1, op_type* op_pt2, Bit32s vib2, op_type* op_pt3, Bit32s vib3) {
Bit32u c1 = op_pt1->tcount/FIXEDPT;
Bit32u c3 = op_pt3->tcount/FIXEDPT;
Bit32u phasebit = (((c1 & 0x88) ^ ((c1<<5) & 0x80)) | ((c3 ^ (c3<<2)) & 0x20)) ? 0x02 : 0x00;
Bit32u noisebit = rand()&1;
Bit32u snare_phase_bit = (((Bitu)((op_pt1->tcount/FIXEDPT) / 0x100))&1);
//Hihat
Bit32u inttm = (phasebit<<8) | (0x34<<(phasebit ^ (noisebit<<1)));
op_pt1->wfpos = inttm*FIXEDPT; // waveform position
// advance waveform time
op_pt1->tcount += op_pt1->tinc;
op_pt1->tcount += (Bit32s)(op_pt1->tinc)*vib1/FIXEDPT;
op_pt1->generator_pos += generator_add;
//Snare
inttm = ((1+snare_phase_bit) ^ noisebit)<<8;
op_pt2->wfpos = inttm*FIXEDPT; // waveform position
// advance waveform time
op_pt2->tcount += op_pt2->tinc;
op_pt2->tcount += (Bit32s)(op_pt2->tinc)*vib2/FIXEDPT;
op_pt2->generator_pos += generator_add;
//Cymbal
inttm = (1+phasebit)<<8;
op_pt3->wfpos = inttm*FIXEDPT; // waveform position
// advance waveform time
op_pt3->tcount += op_pt3->tinc;
op_pt3->tcount += (Bit32s)(op_pt3->tinc)*vib3/FIXEDPT;
op_pt3->generator_pos += generator_add;
}
// output level is sustained, mode changes only when operator is turned off (->release)
// or when the keep-sustained bit is turned off (->sustain_nokeep)
void operator_output(op_type* op_pt, Bit32s modulator, Bit32s trem) {
if (op_pt->op_state != OF_TYPE_OFF) {
op_pt->lastcval = op_pt->cval;
Bit32u i = (Bit32u)((op_pt->wfpos+modulator)/FIXEDPT);
// wform: -16384 to 16383 (0x4000)
// trem : 32768 to 65535 (0x10000)
// step_amp: 0.0 to 1.0
// vol : 1/2^14 to 1/2^29 (/0x4000; /1../0x8000)
op_pt->cval = (Bit32s)(op_pt->step_amp*op_pt->vol*op_pt->cur_wform[i&op_pt->cur_wmask]*trem/16.0);
}
}
// no action, operator is off
void operator_off(op_type* op_pt) {
(void) op_pt;
}
// output level is sustained, mode changes only when operator is turned off (->release)
// or when the keep-sustained bit is turned off (->sustain_nokeep)
void operator_sustain(op_type* op_pt) {
Bit32u num_steps_add = op_pt->generator_pos/FIXEDPT; // number of (standardized) samples
for (Bit32u ct=0; ct<num_steps_add; ct++) {
op_pt->cur_env_step++;
}
op_pt->generator_pos -= num_steps_add*FIXEDPT;
}
// operator in release mode, if output level reaches zero the operator is turned off
void operator_release(op_type* op_pt) {
// ??? boundary?
if (op_pt->amp > 0.00000001) {
// release phase
op_pt->amp *= op_pt->releasemul;
}
Bit32u num_steps_add = op_pt->generator_pos/FIXEDPT; // number of (standardized) samples
for (Bit32u ct=0; ct<num_steps_add; ct++) {
op_pt->cur_env_step++; // sample counter
if ((op_pt->cur_env_step & op_pt->env_step_r)==0) {
if (op_pt->amp <= 0.00000001) {
// release phase finished, turn off this operator
op_pt->amp = 0.0;
if (op_pt->op_state == OF_TYPE_REL) {
op_pt->op_state = OF_TYPE_OFF;
}
}
op_pt->step_amp = op_pt->amp;
}
}
op_pt->generator_pos -= num_steps_add*FIXEDPT;
}
// operator in decay mode, if sustain level is reached the output level is either
// kept (sustain level keep enabled) or the operator is switched into release mode
void operator_decay(op_type* op_pt) {
if (op_pt->amp > op_pt->sustain_level) {
// decay phase
op_pt->amp *= op_pt->decaymul;
}
Bit32u num_steps_add = op_pt->generator_pos/FIXEDPT; // number of (standardized) samples
for (Bit32u ct=0; ct<num_steps_add; ct++) {
op_pt->cur_env_step++;
if ((op_pt->cur_env_step & op_pt->env_step_d)==0) {
if (op_pt->amp <= op_pt->sustain_level) {
// decay phase finished, sustain level reached
if (op_pt->sus_keep) {
// keep sustain level (until turned off)
op_pt->op_state = OF_TYPE_SUS;
op_pt->amp = op_pt->sustain_level;
} else {
// next: release phase
op_pt->op_state = OF_TYPE_SUS_NOKEEP;
}
}
op_pt->step_amp = op_pt->amp;
}
}
op_pt->generator_pos -= num_steps_add*FIXEDPT;
}
// operator in attack mode, if full output level is reached,
// the operator is switched into decay mode
void operator_attack(op_type* op_pt) {
op_pt->amp = ((op_pt->a3*op_pt->amp + op_pt->a2)*op_pt->amp + op_pt->a1)*op_pt->amp + op_pt->a0;
Bit32u num_steps_add = op_pt->generator_pos/FIXEDPT; // number of (standardized) samples
for (Bit32u ct=0; ct<num_steps_add; ct++) {
op_pt->cur_env_step++; // next sample
if ((op_pt->cur_env_step & op_pt->env_step_a)==0) { // check if next step already reached
if (op_pt->amp > 1.0) {
// attack phase finished, next: decay
op_pt->op_state = OF_TYPE_DEC;
op_pt->amp = 1.0;
op_pt->step_amp = 1.0;
}
op_pt->step_skip_pos_a <<= 1;
if (op_pt->step_skip_pos_a==0) op_pt->step_skip_pos_a = 1;
if (op_pt->step_skip_pos_a & op_pt->env_step_skip_a) { // check if required to skip next step
op_pt->step_amp = op_pt->amp;
}
}
}
op_pt->generator_pos -= num_steps_add*FIXEDPT;
}
typedef void (*optype_fptr)(op_type*);
optype_fptr opfuncs[6] = {
operator_attack,
operator_decay,
operator_release,
operator_sustain, // sustain phase (keeping level)
operator_release, // sustain_nokeep phase (release-style)
operator_off
};
void change_attackrate(Bitu regbase, op_type* op_pt) {
Bits attackrate = adlibreg[ARC_ATTR_DECR+regbase]>>4;
if (attackrate) {
fltype f = (fltype)(pow(FL2,(fltype)attackrate+(op_pt->toff>>2)-1)*attackconst[op_pt->toff&3]*recipsamp);
// attack rate coefficients
op_pt->a0 = (fltype)(0.0377*f);
op_pt->a1 = (fltype)(10.73*f+1);
op_pt->a2 = (fltype)(-17.57*f);
op_pt->a3 = (fltype)(7.42*f);
Bits step_skip = attackrate*4 + op_pt->toff;
Bits steps = step_skip >> 2;
op_pt->env_step_a = (1<<(steps<=12?12-steps:0))-1;
Bits step_num = (step_skip<=48)?(4-(step_skip&3)):0;
static Bit8u step_skip_mask[5] = {0xff, 0xfe, 0xee, 0xba, 0xaa};
op_pt->env_step_skip_a = step_skip_mask[step_num];
#if defined(OPLTYPE_IS_OPL3)
if (step_skip>=60) {
#else
if (step_skip>=62) {
#endif
op_pt->a0 = (fltype)(2.0); // something that triggers an immediate transition to amp:=1.0
op_pt->a1 = (fltype)(0.0);
op_pt->a2 = (fltype)(0.0);
op_pt->a3 = (fltype)(0.0);
}
} else {
// attack disabled
op_pt->a0 = 0.0;
op_pt->a1 = 1.0;
op_pt->a2 = 0.0;
op_pt->a3 = 0.0;
op_pt->env_step_a = 0;
op_pt->env_step_skip_a = 0;
}
}
void change_decayrate(Bitu regbase, op_type* op_pt) {
Bits decayrate = adlibreg[ARC_ATTR_DECR+regbase]&15;
// decaymul should be 1.0 when decayrate==0
if (decayrate) {
fltype f = (fltype)(-7.4493*decrelconst[op_pt->toff&3]*recipsamp);
op_pt->decaymul = (fltype)(pow(FL2,f*pow(FL2,(fltype)(decayrate+(op_pt->toff>>2)))));
Bits steps = (decayrate*4 + op_pt->toff) >> 2;
op_pt->env_step_d = (1<<(steps<=12?12-steps:0))-1;
} else {
op_pt->decaymul = 1.0;
op_pt->env_step_d = 0;
}
}
void change_releaserate(Bitu regbase, op_type* op_pt) {
Bits releaserate = adlibreg[ARC_SUSL_RELR+regbase]&15;
// releasemul should be 1.0 when releaserate==0
if (releaserate) {
fltype f = (fltype)(-7.4493*decrelconst[op_pt->toff&3]*recipsamp);
op_pt->releasemul = (fltype)(pow(FL2,f*pow(FL2,(fltype)(releaserate+(op_pt->toff>>2)))));
Bits steps = (releaserate*4 + op_pt->toff) >> 2;
op_pt->env_step_r = (1<<(steps<=12?12-steps:0))-1;
} else {
op_pt->releasemul = 1.0;
op_pt->env_step_r = 0;
}
}
void change_sustainlevel(Bitu regbase, op_type* op_pt) {
Bits sustainlevel = adlibreg[ARC_SUSL_RELR+regbase]>>4;
// sustainlevel should be 0.0 when sustainlevel==15 (max)
if (sustainlevel<15) {
op_pt->sustain_level = (fltype)(pow(FL2,(fltype)sustainlevel * (-FL05)));
} else {
op_pt->sustain_level = 0.0;
}
}
void change_waveform(Bitu regbase, op_type* op_pt) {
#if defined(OPLTYPE_IS_OPL3)
if (regbase>=ARC_SECONDSET) regbase -= (ARC_SECONDSET-22); // second set starts at 22
#endif
// waveform selection
op_pt->cur_wmask = wavemask[wave_sel[regbase]];
op_pt->cur_wform = &wavtable[waveform[wave_sel[regbase]]];
// (might need to be adapted to waveform type here...)
}
void change_keepsustain(Bitu regbase, op_type* op_pt) {
op_pt->sus_keep = (adlibreg[ARC_TVS_KSR_MUL+regbase]&0x20)>0;
if (op_pt->op_state==OF_TYPE_SUS) {
if (!op_pt->sus_keep) op_pt->op_state = OF_TYPE_SUS_NOKEEP;
} else if (op_pt->op_state==OF_TYPE_SUS_NOKEEP) {
if (op_pt->sus_keep) op_pt->op_state = OF_TYPE_SUS;
}
}
// enable/disable vibrato/tremolo LFO effects
void change_vibrato(Bitu regbase, op_type* op_pt) {
op_pt->vibrato = (adlibreg[ARC_TVS_KSR_MUL+regbase]&0x40)!=0;
op_pt->tremolo = (adlibreg[ARC_TVS_KSR_MUL+regbase]&0x80)!=0;
}
// change amount of self-feedback
void change_feedback(Bitu chanbase, op_type* op_pt) {
Bits feedback = adlibreg[ARC_FEEDBACK+chanbase]&14;
if (feedback) op_pt->mfbi = (Bit32s)(pow(FL2,(fltype)((feedback>>1)+8)));
else op_pt->mfbi = 0;
}
void change_frequency(Bitu chanbase, Bitu regbase, op_type* op_pt) {
// frequency
Bit32u frn = ((((Bit32u)adlibreg[ARC_KON_BNUM+chanbase])&3)<<8) + (Bit32u)adlibreg[ARC_FREQ_NUM+chanbase];
// block number/octave
Bit32u oct = ((((Bit32u)adlibreg[ARC_KON_BNUM+chanbase])>>2)&7);
op_pt->freq_high = (Bit32s)((frn>>7)&7);
// keysplit
Bit32u note_sel = (adlibreg[8]>>6)&1;
op_pt->toff = ((frn>>9)&(note_sel^1)) | ((frn>>8)¬e_sel);
op_pt->toff += (oct<<1);
// envelope scaling (KSR)
if (!(adlibreg[ARC_TVS_KSR_MUL+regbase]&0x10)) op_pt->toff >>= 2;
// 20+a0+b0:
op_pt->tinc = (Bit32u)((((fltype)(frn<<oct))*frqmul[adlibreg[ARC_TVS_KSR_MUL+regbase]&15]));
// 40+a0+b0:
fltype vol_in = (fltype)((fltype)(adlibreg[ARC_KSL_OUTLEV+regbase]&63) +
kslmul[adlibreg[ARC_KSL_OUTLEV+regbase]>>6]*kslev[oct][frn>>6]);
op_pt->vol = (fltype)(pow(FL2,(fltype)(vol_in * -0.125 - 14)));
// operator frequency changed, care about features that depend on it
change_attackrate(regbase,op_pt);
change_decayrate(regbase,op_pt);
change_releaserate(regbase,op_pt);
}
void enable_operator(Bitu regbase, op_type* op_pt, Bit32u act_type) {
// check if this is really an off-on transition
if (op_pt->act_state == OP_ACT_OFF) {
Bits wselbase = regbase;
if (wselbase>=ARC_SECONDSET) wselbase -= (ARC_SECONDSET-22); // second set starts at 22
op_pt->tcount = wavestart[wave_sel[wselbase]]*FIXEDPT;
// start with attack mode
op_pt->op_state = OF_TYPE_ATT;
op_pt->act_state |= act_type;
}
}
void disable_operator(op_type* op_pt, Bit32u act_type) {
// check if this is really an on-off transition
if (op_pt->act_state != OP_ACT_OFF) {
op_pt->act_state &= (~act_type);
if (op_pt->act_state == OP_ACT_OFF) {
if (op_pt->op_state != OF_TYPE_OFF) op_pt->op_state = OF_TYPE_REL;
}
}
}
void adlib_init(Bit32u samplerate) {
Bits i, j, oct;
int_samplerate = samplerate;
generator_add = (Bit32u)(INTFREQU*FIXEDPT/int_samplerate);
memset((void *)adlibreg,0,sizeof(adlibreg));
memset((void *)op,0,sizeof(op_type)*MAXOPERATORS);
memset((void *)wave_sel,0,sizeof(wave_sel));
for (i=0;i<MAXOPERATORS;i++) {
op[i].op_state = OF_TYPE_OFF;
op[i].act_state = OP_ACT_OFF;
op[i].amp = 0.0;
op[i].step_amp = 0.0;
op[i].vol = 0.0;
op[i].tcount = 0;
op[i].tinc = 0;
op[i].toff = 0;
op[i].cur_wmask = wavemask[0];
op[i].cur_wform = &wavtable[waveform[0]];
op[i].freq_high = 0;
op[i].generator_pos = 0;
op[i].cur_env_step = 0;
op[i].env_step_a = 0;
op[i].env_step_d = 0;
op[i].env_step_r = 0;
op[i].step_skip_pos_a = 0;
op[i].env_step_skip_a = 0;
#if defined(OPLTYPE_IS_OPL3)
op[i].is_4op = false;
op[i].is_4op_attached = false;
op[i].left_pan = 1;
op[i].right_pan = 1;
#endif
}
recipsamp = 1.0 / (fltype)int_samplerate;
for (i=15;i>=0;i--) {
frqmul[i] = (fltype)(frqmul_tab[i]*INTFREQU/(fltype)WAVEPREC*(fltype)FIXEDPT*recipsamp);
}
status = 0;
opl_index = 0;
// create vibrato table
vib_table[0] = 8;
vib_table[1] = 4;
vib_table[2] = 0;
vib_table[3] = -4;
for (i=4; i<VIBTAB_SIZE; i++) vib_table[i] = vib_table[i-4]*-1;
// vibrato at ~6.1 ?? (opl3 docs say 6.1, opl4 docs say 6.0, y8950 docs say 6.4)
vibtab_add = (Bit32u)(VIBTAB_SIZE*FIXEDPT_LFO/8192*INTFREQU/int_samplerate);
vibtab_pos = 0;
for (i=0; i<BLOCKBUF_SIZE; i++) vibval_const[i] = 0;
// create tremolo table
Bit32s trem_table_int[TREMTAB_SIZE];
for (i=0; i<14; i++) trem_table_int[i] = i-13; // upwards (13 to 26 -> -0.5/6 to 0)
for (i=14; i<41; i++) trem_table_int[i] = -i+14; // downwards (26 to 0 -> 0 to -1/6)
for (i=41; i<53; i++) trem_table_int[i] = i-40-26; // upwards (1 to 12 -> -1/6 to -0.5/6)
for (i=0; i<TREMTAB_SIZE; i++) {
// 0.0 .. -26/26*4.8/6 == [0.0 .. -0.8], 4/53 steps == [1 .. 0.57]
fltype trem_val1=(fltype)(((fltype)trem_table_int[i])*4.8/26.0/6.0); // 4.8db
fltype trem_val2=(fltype)((fltype)((Bit32s)(trem_table_int[i]/4))*1.2/6.0/6.0); // 1.2db (larger stepping)
trem_table[i] = (Bit32s)(pow(FL2,trem_val1)*FIXEDPT);
trem_table[TREMTAB_SIZE+i] = (Bit32s)(pow(FL2,trem_val2)*FIXEDPT);
}
// tremolo at 3.7hz
tremtab_add = (Bit32u)((fltype)TREMTAB_SIZE * TREM_FREQ * FIXEDPT_LFO / (fltype)int_samplerate);
tremtab_pos = 0;
for (i=0; i<BLOCKBUF_SIZE; i++) tremval_const[i] = FIXEDPT;
static Bitu initfirstime = 0;
if (!initfirstime) {
initfirstime = 1;
// create waveform tables
for (i=0;i<(WAVEPREC>>1);i++) {
wavtable[(i<<1) +WAVEPREC] = (Bit16s)(16384*sin((fltype)((i<<1) )*PI*2/WAVEPREC));
wavtable[(i<<1)+1+WAVEPREC] = (Bit16s)(16384*sin((fltype)((i<<1)+1)*PI*2/WAVEPREC));
wavtable[i] = wavtable[(i<<1) +WAVEPREC];
// alternative: (zero-less)
/* wavtable[(i<<1) +WAVEPREC] = (Bit16s)(16384*sin((fltype)((i<<2)+1)*PI/WAVEPREC));
wavtable[(i<<1)+1+WAVEPREC] = (Bit16s)(16384*sin((fltype)((i<<2)+3)*PI/WAVEPREC));
wavtable[i] = wavtable[(i<<1)-1+WAVEPREC]; */
}
for (i=0;i<(WAVEPREC>>3);i++) {
wavtable[i+(WAVEPREC<<1)] = wavtable[i+(WAVEPREC>>3)]-16384;
wavtable[i+((WAVEPREC*17)>>3)] = wavtable[i+(WAVEPREC>>2)]+16384;
}
// key scale level table verified ([table in book]*8/3)
kslev[7][0] = 0; kslev[7][1] = 24; kslev[7][2] = 32; kslev[7][3] = 37;
kslev[7][4] = 40; kslev[7][5] = 43; kslev[7][6] = 45; kslev[7][7] = 47;
kslev[7][8] = 48;
for (i=9;i<16;i++) kslev[7][i] = (Bit8u)(i+41);
for (j=6;j>=0;j--) {
for (i=0;i<16;i++) {
oct = (Bits)kslev[j+1][i]-8;
if (oct < 0) oct = 0;
kslev[j][i] = (Bit8u)oct;
}
}
}
}
void adlib_write(Bitu idx, Bit8u val) {
Bit32u second_set = idx&0x100;
adlibreg[idx] = val;
switch (idx&0xf0) {
case ARC_CONTROL:
// here we check for the second set registers, too:
switch (idx) {
case 0x02: // timer1 counter
case 0x03: // timer2 counter
break;
case 0x04:
// IRQ reset, timer mask/start
if (val&0x80) {
// clear IRQ bits in status register
status &= ~0x60;
} else {
status = 0;
}
break;
#if defined(OPLTYPE_IS_OPL3)
case 0x04|ARC_SECONDSET:
// 4op enable/disable switches for each possible channel
op[0].is_4op = (val&1)>0;
op[3].is_4op_attached = op[0].is_4op;
op[1].is_4op = (val&2)>0;
op[4].is_4op_attached = op[1].is_4op;
op[2].is_4op = (val&4)>0;
op[5].is_4op_attached = op[2].is_4op;
op[18].is_4op = (val&8)>0;
op[21].is_4op_attached = op[18].is_4op;
op[19].is_4op = (val&16)>0;
op[22].is_4op_attached = op[19].is_4op;
op[20].is_4op = (val&32)>0;
op[23].is_4op_attached = op[20].is_4op;
break;
case 0x05|ARC_SECONDSET:
break;
#endif
case 0x08:
// CSW, note select
break;
default:
break;
}
break;
case ARC_TVS_KSR_MUL:
case ARC_TVS_KSR_MUL+0x10: {
// tremolo/vibrato/sustain keeping enabled; key scale rate; frequency multiplication
int num = idx&7;
Bitu base = (idx-ARC_TVS_KSR_MUL)&0xff;
if ((num<6) && (base<22)) {
Bitu modop = regbase2modop[second_set?(base+22):base];
Bitu regbase = base+second_set;
Bitu chanbase = second_set?(modop-18+ARC_SECONDSET):modop;
// change tremolo/vibrato and sustain keeping of this operator
op_type* op_ptr = &op[modop+((num<3) ? 0 : 9)];
change_keepsustain(regbase,op_ptr);
change_vibrato(regbase,op_ptr);
// change frequency calculations of this operator as
// key scale rate and frequency multiplicator can be changed
#if defined(OPLTYPE_IS_OPL3)
if ((adlibreg[0x105]&1) && (op[modop].is_4op_attached)) {
// operator uses frequency of channel
change_frequency(chanbase-3,regbase,op_ptr);
} else {
change_frequency(chanbase,regbase,op_ptr);
}
#else
change_frequency(chanbase,base,op_ptr);
#endif
}
}
break;
case ARC_KSL_OUTLEV:
case ARC_KSL_OUTLEV+0x10: {
// key scale level; output rate
int num = idx&7;
Bitu base = (idx-ARC_KSL_OUTLEV)&0xff;
if ((num<6) && (base<22)) {
Bitu modop = regbase2modop[second_set?(base+22):base];
Bitu chanbase = second_set?(modop-18+ARC_SECONDSET):modop;
// change frequency calculations of this operator as
// key scale level and output rate can be changed
op_type* op_ptr = &op[modop+((num<3) ? 0 : 9)];
#if defined(OPLTYPE_IS_OPL3)
Bitu regbase = base+second_set;
if ((adlibreg[0x105]&1) && (op[modop].is_4op_attached)) {
// operator uses frequency of channel
change_frequency(chanbase-3,regbase,op_ptr);
} else {
change_frequency(chanbase,regbase,op_ptr);
}
#else
change_frequency(chanbase,base,op_ptr);
#endif
}
}
break;
case ARC_ATTR_DECR:
case ARC_ATTR_DECR+0x10: {
// attack/decay rates
int num = idx&7;
Bitu base = (idx-ARC_ATTR_DECR)&0xff;
if ((num<6) && (base<22)) {
Bitu regbase = base+second_set;
// change attack rate and decay rate of this operator
op_type* op_ptr = &op[regbase2op[second_set?(base+22):base]];
change_attackrate(regbase,op_ptr);
change_decayrate(regbase,op_ptr);
}
}
break;
case ARC_SUSL_RELR:
case ARC_SUSL_RELR+0x10: {
// sustain level; release rate
int num = idx&7;
Bitu base = (idx-ARC_SUSL_RELR)&0xff;
if ((num<6) && (base<22)) {
Bitu regbase = base+second_set;
// change sustain level and release rate of this operator
op_type* op_ptr = &op[regbase2op[second_set?(base+22):base]];
change_releaserate(regbase,op_ptr);
change_sustainlevel(regbase,op_ptr);
}
}
break;
case ARC_FREQ_NUM: {
// 0xa0-0xa8 low8 frequency
Bitu base = (idx-ARC_FREQ_NUM)&0xff;
if (base<9) {
Bits opbase = second_set?(base+18):base;
#if defined(OPLTYPE_IS_OPL3)
if ((adlibreg[0x105]&1) && op[opbase].is_4op_attached) break;
#endif
// regbase of modulator:
Bits modbase = modulatorbase[base]+second_set;
Bitu chanbase = base+second_set;
change_frequency(chanbase,modbase,&op[opbase]);
change_frequency(chanbase,modbase+3,&op[opbase+9]);
#if defined(OPLTYPE_IS_OPL3)
// for 4op channels all four operators are modified to the frequency of the channel
if ((adlibreg[0x105]&1) && op[second_set?(base+18):base].is_4op) {
change_frequency(chanbase,modbase+8,&op[opbase+3]);
change_frequency(chanbase,modbase+3+8,&op[opbase+3+9]);
}
#endif
}
}
break;
case ARC_KON_BNUM: {
if (idx == ARC_PERC_MODE) {
#if defined(OPLTYPE_IS_OPL3)
if (second_set) return;
#endif
if ((val&0x30) == 0x30) { // BassDrum active
enable_operator(16,&op[6],OP_ACT_PERC);
change_frequency(6,16,&op[6]);
enable_operator(16+3,&op[6+9],OP_ACT_PERC);
change_frequency(6,16+3,&op[6+9]);
} else {
disable_operator(&op[6],OP_ACT_PERC);
disable_operator(&op[6+9],OP_ACT_PERC);
}
if ((val&0x28) == 0x28) { // Snare active
enable_operator(17+3,&op[16],OP_ACT_PERC);
change_frequency(7,17+3,&op[16]);
} else {
disable_operator(&op[16],OP_ACT_PERC);
}
if ((val&0x24) == 0x24) { // TomTom active
enable_operator(18,&op[8],OP_ACT_PERC);
change_frequency(8,18,&op[8]);
} else {
disable_operator(&op[8],OP_ACT_PERC);
}
if ((val&0x22) == 0x22) { // Cymbal active
enable_operator(18+3,&op[8+9],OP_ACT_PERC);
change_frequency(8,18+3,&op[8+9]);
} else {
disable_operator(&op[8+9],OP_ACT_PERC);
}
if ((val&0x21) == 0x21) { // Hihat active
enable_operator(17,&op[7],OP_ACT_PERC);
change_frequency(7,17,&op[7]);
} else {
disable_operator(&op[7],OP_ACT_PERC);
}
break;
}
// regular 0xb0-0xb8
Bitu base = (idx-ARC_KON_BNUM)&0xff;
if (base<9) {
Bits opbase = second_set?(base+18):base;
#if defined(OPLTYPE_IS_OPL3)
if ((adlibreg[0x105]&1) && op[opbase].is_4op_attached) break;
#endif
// regbase of modulator:
Bits modbase = modulatorbase[base]+second_set;
if (val&32) {
// operator switched on
enable_operator(modbase,&op[opbase],OP_ACT_NORMAL); // modulator (if 2op)
enable_operator(modbase+3,&op[opbase+9],OP_ACT_NORMAL); // carrier (if 2op)
#if defined(OPLTYPE_IS_OPL3)
// for 4op channels all four operators are switched on
if ((adlibreg[0x105]&1) && op[opbase].is_4op) {
// turn on chan+3 operators as well
enable_operator(modbase+8,&op[opbase+3],OP_ACT_NORMAL);
enable_operator(modbase+3+8,&op[opbase+3+9],OP_ACT_NORMAL);
}
#endif
} else {
// operator switched off
disable_operator(&op[opbase],OP_ACT_NORMAL);
disable_operator(&op[opbase+9],OP_ACT_NORMAL);
#if defined(OPLTYPE_IS_OPL3)
// for 4op channels all four operators are switched off
if ((adlibreg[0x105]&1) && op[opbase].is_4op) {
// turn off chan+3 operators as well
disable_operator(&op[opbase+3],OP_ACT_NORMAL);
disable_operator(&op[opbase+3+9],OP_ACT_NORMAL);
}
#endif
}
Bitu chanbase = base+second_set;
// change frequency calculations of modulator and carrier (2op) as
// the frequency of the channel has changed
change_frequency(chanbase,modbase,&op[opbase]);
change_frequency(chanbase,modbase+3,&op[opbase+9]);
#if defined(OPLTYPE_IS_OPL3)
// for 4op channels all four operators are modified to the frequency of the channel
if ((adlibreg[0x105]&1) && op[second_set?(base+18):base].is_4op) {
// change frequency calculations of chan+3 operators as well
change_frequency(chanbase,modbase+8,&op[opbase+3]);
change_frequency(chanbase,modbase+3+8,&op[opbase+3+9]);
}
#endif
}
}
break;
case ARC_FEEDBACK: {
// 0xc0-0xc8 feedback/modulation type (AM/FM)
Bitu base = (idx-ARC_FEEDBACK)&0xff;
if (base<9) {
Bits opbase = second_set?(base+18):base;
Bitu chanbase = base+second_set;
change_feedback(chanbase,&op[opbase]);
#if defined(OPLTYPE_IS_OPL3)
// OPL3 panning
op[opbase].left_pan = ((val&0x10)>>4);
op[opbase].right_pan = ((val&0x20)>>5);
#endif
}
}
break;
case ARC_WAVE_SEL:
case ARC_WAVE_SEL+0x10: {
int num = idx&7;
Bitu base = (idx-ARC_WAVE_SEL)&0xff;
if ((num<6) && (base<22)) {
#if defined(OPLTYPE_IS_OPL3)
Bits wselbase = second_set?(base+22):base; // for easier mapping onto wave_sel[]
// change waveform
if (adlibreg[0x105]&1) wave_sel[wselbase] = val&7; // opl3 mode enabled, all waveforms accessible
else wave_sel[wselbase] = val&3;
op_type* op_ptr = &op[regbase2modop[wselbase]+((num<3) ? 0 : 9)];
change_waveform(wselbase,op_ptr);
#else
if (adlibreg[0x01]&0x20) {
// wave selection enabled, change waveform
wave_sel[base] = val&3;
op_type* op_ptr = &op[regbase2modop[base]+((num<3) ? 0 : 9)];
change_waveform(base,op_ptr);
}
#endif
}
}
break;
default:
break;
}
}
Bitu adlib_reg_read(Bitu port) {
#if defined(OPLTYPE_IS_OPL3)
// opl3-detection routines require ret&6 to be zero
if ((port&1)==0) {
return status;
}
return 0x00;
#else
// opl2-detection routines require ret&6 to be 6
if ((port&1)==0) {
return status|6;
}
return 0xff;
#endif
}
void adlib_write_index(Bitu port, Bit8u val) {
opl_index = val;
#if defined(OPLTYPE_IS_OPL3)
if ((port&3)!=0) {
// possibly second set
if (((adlibreg[0x105]&1)!=0) || (opl_index==5)) opl_index |= ARC_SECONDSET;
}
#endif
}
static void OPL_INLINE clipit16(Bit32s ival, Bit16s* outval) {
if (ival<32768) {
if (ival>-32769) {
*outval=(Bit16s)ival;
} else {
*outval = -32768;
}
} else {
*outval = 32767;
}
}
// be careful with this
// uses cptr and chanval, outputs into outbufl(/outbufr)
// for opl3 check if opl3-mode is enabled (which uses stereo panning)
#undef CHANVAL_OUT
#if defined(OPLTYPE_IS_OPL3)
#define CHANVAL_OUT \
if (adlibreg[0x105]&1) { \
outbufl[i] += chanval*cptr[0].left_pan; \
outbufr[i] += chanval*cptr[0].right_pan; \
} else { \
outbufl[i] += chanval; \
}
#else
#define CHANVAL_OUT \
outbufl[i] += chanval;
#endif
void adlib_getsample(Bit16s* sndptr, Bits numsamples) {
Bits i, endsamples;
op_type* cptr;
Bit32s outbufl[BLOCKBUF_SIZE];
#if defined(OPLTYPE_IS_OPL3)
// second output buffer (right channel for opl3 stereo)
Bit32s outbufr[BLOCKBUF_SIZE];
#endif
// vibrato/tremolo lookup tables (global, to possibly be used by all operators)
Bit32s vib_lut[BLOCKBUF_SIZE];
Bit32s trem_lut[BLOCKBUF_SIZE];
Bits samples_to_process = numsamples;
for (Bits cursmp=0; cursmp<samples_to_process; cursmp+=endsamples) {
endsamples = samples_to_process-cursmp;
if (endsamples>BLOCKBUF_SIZE) endsamples = BLOCKBUF_SIZE;
memset((void*)&outbufl,0,endsamples*sizeof(Bit32s));
#if defined(OPLTYPE_IS_OPL3)
// clear second output buffer (opl3 stereo)
if (adlibreg[0x105]&1) memset((void*)&outbufr,0,endsamples*sizeof(Bit32s));
#endif
// calculate vibrato/tremolo lookup tables
Bit32s vib_tshift = ((adlibreg[ARC_PERC_MODE]&0x40)==0) ? 1 : 0; // 14cents/7cents switching
for (i=0;i<endsamples;i++) {
// cycle through vibrato table
vibtab_pos += vibtab_add;
if (vibtab_pos/FIXEDPT_LFO>=VIBTAB_SIZE) vibtab_pos-=VIBTAB_SIZE*FIXEDPT_LFO;
vib_lut[i] = vib_table[vibtab_pos/FIXEDPT_LFO]>>vib_tshift; // 14cents (14/100 of a semitone) or 7cents
// cycle through tremolo table
tremtab_pos += tremtab_add;
if (tremtab_pos/FIXEDPT_LFO>=TREMTAB_SIZE) tremtab_pos-=TREMTAB_SIZE*FIXEDPT_LFO;
if (adlibreg[ARC_PERC_MODE]&0x80) trem_lut[i] = trem_table[tremtab_pos/FIXEDPT_LFO];
else trem_lut[i] = trem_table[TREMTAB_SIZE+tremtab_pos/FIXEDPT_LFO];
}
if (adlibreg[ARC_PERC_MODE]&0x20) {
//BassDrum
cptr = &op[6];
if (adlibreg[ARC_FEEDBACK+6]&1) {
// additive synthesis
if (cptr[9].op_state != OF_TYPE_OFF) {
if (cptr[9].vibrato) {