1 /*
2  * Copyright (C) 1999/2000 Tatsuyuki Satoh
3  * Copyright (C) 2001-2016 The ScummVM project
4  * Copyright (C) 2002/2016 The Exult Team
5  * Copyright (C) 2003 The Pentagram Team
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version 2
10  * of the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20  *
21  * LGPL licensed version of MAMEs fmopl (V0.37a modified) by
22  * Tatsuyuki Satoh. Included from LGPL'ed AdPlug.
23  *
24  */
25 
26 #include "pent_include.h"
27 
28 #ifdef USE_FMOPL_MIDI
29 
30 #include <cstdio>
31 #include <cstdlib>
32 #include <cstring>
33 #include <cstdarg>
34 #include <cmath>
35 #include <iostream>
36 #include "fmopl.h"
37 #include "array_size.h"
38 
39 #ifndef M_PI
40 #define M_PI 3.14159265358979323846
41 #endif
42 
43 #ifndef ARRAYSIZE
44 #define ARRAYSIZE(x) (array_size(x))
45 #endif
46 
47 namespace FMOpl_Pentagram {
48 
49 /* -------------------- preliminary define section --------------------- */
50 /* attack/decay rate time rate */
51 #define OPL_ARRATE     141280  /* RATE 4 =  2826.24ms @ 3.6MHz */
52 #define OPL_DRRATE    1956000  /* RATE 4 = 39280.64ms @ 3.6MHz */
53 
54 #define FREQ_BITS 24			/* frequency turn          */
55 
56 /* counter bits = 20 , octerve 7 */
57 #define FREQ_RATE   (1<<(FREQ_BITS-20))
58 #define TL_BITS    (FREQ_BITS+2)
59 
60 /* final output shift , limit minimum and maximum */
61 #define OPL_OUTSB   (TL_BITS+3-16)		/* OPL output final shift 16bit */
62 #define OPL_MAXOUT   (0x7fff<<OPL_OUTSB)
63 #define OPL_MINOUT (-(0x8000<<OPL_OUTSB))
64 
65 /* -------------------- quality selection --------------------- */
66 
67 /* sinwave entries */
68 /* used static memory = SIN_ENT * 4 (byte) */
69 #define SIN_ENT_SHIFT 11
70 #define SIN_ENT (1<<SIN_ENT_SHIFT)
71 
72 /* output level entries (envelope,sinwave) */
73 /* envelope counter lower bits */
74 uint32 ENV_BITS;
75 /* envelope output entries */
76 uint32 EG_ENT;
77 
78 /* used dynamic memory = EG_ENT*4*4(byte)or EG_ENT*6*4(byte) */
79 /* used static  memory = EG_ENT*4 (byte)                     */
80 uint32 EG_OFF;								 /* OFF */
81 uint32 EG_DED;
82 uint32 EG_DST;								 /* DECAY START */
83 uint32 EG_AED;
84 #define EG_AST   0                       /* ATTACK START */
85 
86 #define EG_STEP (96.0/EG_ENT) /* OPL is 0.1875 dB step  */
87 
88 /* LFO table entries */
89 #define VIB_ENT 512
90 #define VIB_SHIFT (32-9)
91 #define AMS_ENT 512
92 #define AMS_SHIFT (32-9)
93 
94 #define VIB_RATE_SHIFT 8
95 #define VIB_RATE (1<<VIB_RATE_SHIFT)
96 
97 /* -------------------- local defines , macros --------------------- */
98 
99 /* register number to channel number , slot offset */
100 #define SLOT1 0
101 #define SLOT2 1
102 
103 /* envelope phase */
104 #define ENV_MOD_RR  0x00
105 #define ENV_MOD_DR  0x01
106 #define ENV_MOD_AR  0x02
107 
108 /* -------------------- tables --------------------- */
109 static const int slot_array[32] = {
110 	 0, 2, 4, 1, 3, 5,-1,-1,
111 	 6, 8,10, 7, 9,11,-1,-1,
112 	12,14,16,13,15,17,-1,-1,
113 	-1,-1,-1,-1,-1,-1,-1,-1
114 };
115 
116 static uint32 KSL_TABLE[8 * 16];
117 
118 static const double KSL_TABLE_SEED[8 * 16] = {
119 	/* OCT 0 */
120 	0.000, 0.000, 0.000, 0.000,
121 	0.000, 0.000, 0.000, 0.000,
122 	0.000, 0.000, 0.000, 0.000,
123 	0.000, 0.000, 0.000, 0.000,
124 	/* OCT 1 */
125 	0.000, 0.000, 0.000, 0.000,
126 	0.000, 0.000, 0.000, 0.000,
127 	0.000, 0.750, 1.125, 1.500,
128 	1.875, 2.250, 2.625, 3.000,
129 	/* OCT 2 */
130 	0.000, 0.000, 0.000, 0.000,
131 	0.000, 1.125, 1.875, 2.625,
132 	3.000, 3.750, 4.125, 4.500,
133 	4.875, 5.250, 5.625, 6.000,
134 	/* OCT 3 */
135 	0.000, 0.000, 0.000, 1.875,
136 	3.000, 4.125, 4.875, 5.625,
137 	6.000, 6.750, 7.125, 7.500,
138 	7.875, 8.250, 8.625, 9.000,
139 	/* OCT 4 */
140 	0.000, 0.000, 3.000, 4.875,
141 	6.000, 7.125, 7.875, 8.625,
142 	9.000, 9.750, 10.125, 10.500,
143 	10.875, 11.250, 11.625, 12.000,
144 	/* OCT 5 */
145 	0.000, 3.000, 6.000, 7.875,
146 	9.000, 10.125, 10.875, 11.625,
147 	12.000, 12.750, 13.125, 13.500,
148 	13.875, 14.250, 14.625, 15.000,
149 	/* OCT 6 */
150 	0.000, 6.000, 9.000, 10.875,
151 	12.000, 13.125, 13.875, 14.625,
152 	15.000, 15.750, 16.125, 16.500,
153 	16.875, 17.250, 17.625, 18.000,
154 	/* OCT 7 */
155 	0.000, 9.000, 12.000, 13.875,
156 	15.000, 16.125, 16.875, 17.625,
157 	18.000, 18.750, 19.125, 19.500,
158 	19.875, 20.250, 20.625, 21.000
159 };
160 
161 /* sustain level table (3db per step) */
162 /* 0 - 15: 0, 3, 6, 9,12,15,18,21,24,27,30,33,36,39,42,93 (dB)*/
163 
164 static int SL_TABLE[16];
165 
166 static const uint32 SL_TABLE_SEED[16] = {
167 	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 31
168 };
169 
170 #define TL_MAX (EG_ENT * 2) /* limit(tl + ksr + envelope) + sinwave */
171 /* TotalLevel : 48 24 12  6  3 1.5 0.75 (dB) */
172 /* TL_TABLE[ 0      to TL_MAX          ] : plus  section */
173 /* TL_TABLE[ TL_MAX to TL_MAX+TL_MAX-1 ] : minus section */
174 static int *TL_TABLE;
175 
176 /* pointers to TL_TABLE with sinwave output offset */
177 static int **SIN_TABLE;
178 
179 /* LFO table */
180 static int *AMS_TABLE;
181 static int *VIB_TABLE;
182 
183 /* envelope output curve table */
184 /* attack + decay + OFF */
185 //static int ENV_CURVE[2*EG_ENT+1];
186 //static int ENV_CURVE[2 * 4096 + 1];   // to keep it static ...
187 static int *ENV_CURVE;
188 
189 
190 /* multiple table */
191 #define ML(a) static_cast<uint32>((a) * 2)
192 static const uint32 MUL_TABLE[16]= {
193 /* 1/2, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15 */
194 	ML(0.50), ML(1.00), ML(2.00),  ML(3.00), ML(4.00), ML(5.00), ML(6.00), ML(7.00),
195 	ML(8.00), ML(9.00), ML(10.00), ML(10.00),ML(12.00),ML(12.00),ML(15.00),ML(15.00)
196 };
197 #undef ML
198 
199 /* dummy attack / decay rate ( when rate == 0 ) */
200 static int RATE_0[16]=
201 {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
202 
203 /* -------------------- static state --------------------- */
204 
205 /* lock level of common table */
206 static int num_lock = 0;
207 
208 /* work table */
209 static void *cur_chip = nullptr;	/* current chip point */
210 /* currenct chip state */
211 /* static OPLSAMPLE  *bufL,*bufR; */
212 static OPL_CH *S_CH;
213 static OPL_CH *E_CH;
214 OPL_SLOT *SLOT7_1, *SLOT7_2, *SLOT8_1, *SLOT8_2;
215 
216 static int outd[1];
217 static int ams;
218 static int vib;
219 int *ams_table;
220 int *vib_table;
221 static int amsIncr;
222 static int vibIncr;
223 static int feedback2;		/* connect for SLOT 2 */
224 
225 /* --------------------- subroutines  --------------------- */
226 
CLIP(int val,int min,int max)227 inline int CLIP( int val, int min, int max) {
228 	if (val > max)
229 		val = max;
230 	else if (val < min)
231 		val = min;
232 
233 	return val;
234 }
235 
236 /* --------------------- rebuild tables ------------------- */
237 
238 #define SC_KSL(mydb) (static_cast<uint32>((mydb) / (EG_STEP / 2)))
239 #define SC_SL(db) (static_cast<int>((db) * ((3 / EG_STEP) * (1 << ENV_BITS))) + EG_DST)
240 
OPLBuildTables(uint32 ENV_BITS_PARAM,uint32 EG_ENT_PARAM)241 void OPLBuildTables(uint32 ENV_BITS_PARAM, uint32 EG_ENT_PARAM) {
242 	ENV_BITS = ENV_BITS_PARAM;
243 	EG_ENT = EG_ENT_PARAM;
244 	EG_OFF = ((2u * EG_ENT)<<ENV_BITS);  /* OFF          */
245 	EG_DED = EG_OFF;
246 	EG_DST = (EG_ENT << ENV_BITS);     /* DECAY  START */
247 	EG_AED = EG_DST;
248 	//EG_STEP = (96.0/EG_ENT);
249 
250 	for (unsigned i = 0; i < ARRAYSIZE(KSL_TABLE_SEED); i++)
251 		KSL_TABLE[i] = SC_KSL(KSL_TABLE_SEED[i]);
252 
253 	for (unsigned i = 0; i < ARRAYSIZE(SL_TABLE_SEED); i++)
254 		SL_TABLE[i] = SC_SL(SL_TABLE_SEED[i]);
255 }
256 
257 #undef SC_KSL
258 #undef SC_SL
259 
260 /* --------------------- subroutines  --------------------- */
261 
262 /* status set and IRQ handling */
OPL_STATUS_SET(FM_OPL * OPL,int flag)263 inline void OPL_STATUS_SET(FM_OPL *OPL, int flag) {
264 	/* set status flag */
265 	OPL->status |= flag;
266 	if (!(OPL->status & 0x80)) {
267 		if (OPL->status & OPL->statusmask) {	/* IRQ on */
268 			OPL->status |= 0x80;
269 			/* callback user interrupt handler (IRQ is OFF to ON) */
270 			if (OPL->IRQHandler)
271 				(OPL->IRQHandler)(OPL->IRQParam,1);
272 		}
273 	}
274 }
275 
276 /* status reset and IRQ handling */
OPL_STATUS_RESET(FM_OPL * OPL,int flag)277 inline void OPL_STATUS_RESET(FM_OPL *OPL, int flag) {
278 	/* reset status flag */
279 	OPL->status &= ~flag;
280 	if ((OPL->status & 0x80)) {
281 		if (!(OPL->status & OPL->statusmask)) {
282 			OPL->status &= 0x7f;
283 			/* callback user interrupt handler (IRQ is ON to OFF) */
284 			if (OPL->IRQHandler) (OPL->IRQHandler)(OPL->IRQParam,0);
285 		}
286 	}
287 }
288 
289 /* IRQ mask set */
OPL_STATUSMASK_SET(FM_OPL * OPL,int flag)290 inline void OPL_STATUSMASK_SET(FM_OPL *OPL, int flag) {
291 	OPL->statusmask = flag;
292 	/* IRQ handling check */
293 	OPL_STATUS_SET(OPL,0);
294 	OPL_STATUS_RESET(OPL,0);
295 }
296 
297 /* ----- key on  ----- */
OPL_KEYON(OPL_SLOT * SLOT)298 inline void OPL_KEYON(OPL_SLOT *SLOT) {
299 	/* sin wave restart */
300 	SLOT->Cnt = 0;
301 	/* set attack */
302 	SLOT->evm = ENV_MOD_AR;
303 	SLOT->evs = SLOT->evsa;
304 	SLOT->evc = EG_AST;
305 	SLOT->eve = EG_AED;
306 }
307 
308 /* ----- key off ----- */
OPL_KEYOFF(OPL_SLOT * SLOT)309 inline void OPL_KEYOFF(OPL_SLOT *SLOT) {
310 	if (SLOT->evm > ENV_MOD_RR) {
311 		/* set envelope counter from envleope output */
312 
313 		// WORKAROUND: The Kyra engine does something very strange when
314 		// starting a new song. For each channel:
315 		//
316 		// * The release rate is set to "fastest".
317 		// * Any note is keyed off.
318 		// * A very low-frequency note is keyed on.
319 		//
320 		// Usually, what happens next is that the real notes is keyed
321 		// on immediately, in which case there's no problem.
322 		//
323 		// However, if the note is again keyed off (because the channel
324 		// begins on a rest rather than a note), the envelope counter
325 		// was moved from the very lowest point on the attack curve to
326 		// the very highest point on the release curve.
327 		//
328 		// Again, this might not be a problem, if the release rate is
329 		// still set to "fastest". But in many cases, it had already
330 		// been increased. And, possibly because of inaccuracies in the
331 		// envelope generator, that would cause the note to "fade out"
332 		// for quite a long time.
333 		//
334 		// What we really need is a way to find the correct starting
335 		// point for the envelope counter, and that may be what the
336 		// commented-out line below is meant to do. For now, simply
337 		// handle the pathological case.
338 
339 		if (SLOT->evm == ENV_MOD_AR && SLOT->evc == EG_AST)
340 			SLOT->evc = EG_DED;
341 		else if (!(SLOT->evc & EG_DST))
342 			//SLOT->evc = (ENV_CURVE[SLOT->evc>>ENV_BITS]<<ENV_BITS) + EG_DST;
343 			SLOT->evc = EG_DST;
344 		SLOT->eve = EG_DED;
345 		SLOT->evs = SLOT->evsr;
346 		SLOT->evm = ENV_MOD_RR;
347 	}
348 }
349 
350 /* ---------- calcrate Envelope Generator & Phase Generator ---------- */
351 
352 /* return : envelope output */
OPL_CALC_SLOT(OPL_SLOT * SLOT)353 inline uint32 OPL_CALC_SLOT(OPL_SLOT *SLOT) {
354 	/* calcrate envelope generator */
355 	if ((SLOT->evc += SLOT->evs) >= SLOT->eve) {
356 		switch (SLOT->evm) {
357 		case ENV_MOD_AR: /* ATTACK -> DECAY1 */
358 			/* next DR */
359 			SLOT->evm = ENV_MOD_DR;
360 			SLOT->evc = EG_DST;
361 			SLOT->eve = SLOT->SL;
362 			SLOT->evs = SLOT->evsd;
363 			break;
364 		case ENV_MOD_DR: /* DECAY -> SL or RR */
365 			SLOT->evc = SLOT->SL;
366 			SLOT->eve = EG_DED;
367 			if (SLOT->eg_typ) {
368 				SLOT->evs = 0;
369 			} else {
370 				SLOT->evm = ENV_MOD_RR;
371 				SLOT->evs = SLOT->evsr;
372 			}
373 			break;
374 		case ENV_MOD_RR: /* RR -> OFF */
375 			SLOT->evc = EG_OFF;
376 			SLOT->eve = EG_OFF + 1;
377 			SLOT->evs = 0;
378 			break;
379 		}
380 	}
381 	/* calcrate envelope */
382 	return SLOT->TLL + ENV_CURVE[SLOT->evc>>ENV_BITS] + (SLOT->ams ? ams : 0);
383 }
384 
385 /* set algorythm connection */
set_algorythm(OPL_CH * CH)386 static void set_algorythm(OPL_CH *CH) {
387 	int *carrier = &outd[0];
388 	CH->connect1 = CH->CON ? carrier : &feedback2;
389 	CH->connect2 = carrier;
390 }
391 
392 /* ---------- frequency counter for operater update ---------- */
CALC_FCSLOT(OPL_CH * CH,OPL_SLOT * SLOT)393 inline void CALC_FCSLOT(OPL_CH *CH, OPL_SLOT *SLOT) {
394 	int ksr;
395 
396 	/* frequency step counter */
397 	SLOT->Incr = CH->fc * SLOT->mul;
398 	ksr = CH->kcode >> SLOT->KSR;
399 
400 	if (SLOT->ksr != ksr) {
401 		SLOT->ksr = ksr;
402 		/* attack , decay rate recalcration */
403 		SLOT->evsa = SLOT->AR[ksr];
404 		SLOT->evsd = SLOT->DR[ksr];
405 		SLOT->evsr = SLOT->RR[ksr];
406 	}
407 	SLOT->TLL = SLOT->TL + (CH->ksl_base>>SLOT->ksl);
408 }
409 
410 /* set multi,am,vib,EG-TYP,KSR,mul */
set_mul(FM_OPL * OPL,int slot,int v)411 inline void set_mul(FM_OPL *OPL, int slot, int v) {
412 	OPL_CH   *CH   = &OPL->P_CH[slot>>1];
413 	OPL_SLOT *SLOT = &CH->SLOT[slot & 1];
414 
415 	SLOT->mul    = MUL_TABLE[v & 0x0f];
416 	SLOT->KSR    = (v & 0x10) ? 0 : 2;
417 	SLOT->eg_typ = (v & 0x20) >> 5;
418 	SLOT->vib    = (v & 0x40);
419 	SLOT->ams    = (v & 0x80);
420 	CALC_FCSLOT(CH, SLOT);
421 }
422 
423 /* set ksl & tl */
set_ksl_tl(FM_OPL * OPL,int slot,int v)424 inline void set_ksl_tl(FM_OPL *OPL, int slot, int v) {
425 	OPL_CH   *CH   = &OPL->P_CH[slot>>1];
426 	OPL_SLOT *SLOT = &CH->SLOT[slot & 1];
427 	int ksl = v >> 6; /* 0 / 1.5 / 3 / 6 db/OCT */
428 
429 	SLOT->ksl = ksl ? 3-ksl : 31;
430 	SLOT->TL  = static_cast<int>((v & 0x3f) * (0.75 / EG_STEP)); /* 0.75db step */
431 
432 	if (!(OPL->mode & 0x80)) {	/* not CSM latch total level */
433 		SLOT->TLL = SLOT->TL + (CH->ksl_base >> SLOT->ksl);
434 	}
435 }
436 
437 /* set attack rate & decay rate  */
set_ar_dr(FM_OPL * OPL,int slot,int v)438 inline void set_ar_dr(FM_OPL *OPL, int slot, int v) {
439 	OPL_CH   *CH   = &OPL->P_CH[slot>>1];
440 	OPL_SLOT *SLOT = &CH->SLOT[slot & 1];
441 	int ar = v >> 4;
442 	int dr = v & 0x0f;
443 
444 	SLOT->AR = ar ? &OPL->AR_TABLE[ar << 2] : RATE_0;
445 	SLOT->evsa = SLOT->AR[SLOT->ksr];
446 	if (SLOT->evm == ENV_MOD_AR)
447 		SLOT->evs = SLOT->evsa;
448 
449 	SLOT->DR = dr ? &OPL->DR_TABLE[dr<<2] : RATE_0;
450 	SLOT->evsd = SLOT->DR[SLOT->ksr];
451 	if (SLOT->evm == ENV_MOD_DR)
452 		SLOT->evs = SLOT->evsd;
453 }
454 
455 /* set sustain level & release rate */
set_sl_rr(FM_OPL * OPL,int slot,int v)456 inline void set_sl_rr(FM_OPL *OPL, int slot, int v) {
457 	OPL_CH   *CH   = &OPL->P_CH[slot>>1];
458 	OPL_SLOT *SLOT = &CH->SLOT[slot & 1];
459 	int sl = v >> 4;
460 	int rr = v & 0x0f;
461 
462 	SLOT->SL = SL_TABLE[sl];
463 	if (SLOT->evm == ENV_MOD_DR)
464 		SLOT->eve = SLOT->SL;
465 	SLOT->RR = &OPL->DR_TABLE[rr<<2];
466 	SLOT->evsr = SLOT->RR[SLOT->ksr];
467 	if (SLOT->evm == ENV_MOD_RR)
468 		SLOT->evs = SLOT->evsr;
469 }
470 
471 /* operator output calcrator */
472 
473 #define OP_OUT(slot,env,con)   slot->wavetable[(((slot)->Cnt + (con))>>(24-SIN_ENT_SHIFT)) & (SIN_ENT-1)][env]
474 /* ---------- calcrate one of channel ---------- */
OPL_CALC_CH(OPL_CH * CH)475 inline void OPL_CALC_CH(OPL_CH *CH) {
476 	uint32 env_out;
477 	OPL_SLOT *SLOT;
478 
479 	feedback2 = 0;
480 	/* SLOT 1 */
481 	SLOT = &CH->SLOT[SLOT1];
482 	env_out=OPL_CALC_SLOT(SLOT);
483 	if (env_out < (EG_ENT - 1)) {
484 		/* PG */
485 		if (SLOT->vib)
486 			SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
487 		else
488 			SLOT->Cnt += SLOT->Incr;
489 		/* connection */
490 		if (CH->FB) {
491 			int feedback1 = (CH->op1_out[0] + CH->op1_out[1]) >> CH->FB;
492 			CH->op1_out[1] = CH->op1_out[0];
493 			*CH->connect1 += CH->op1_out[0] = OP_OUT(SLOT, env_out, feedback1);
494 		} else {
495 			*CH->connect1 += OP_OUT(SLOT, env_out, 0);
496 		}
497 	} else {
498 		CH->op1_out[1] = CH->op1_out[0];
499 		CH->op1_out[0] = 0;
500 	}
501 	/* SLOT 2 */
502 	SLOT = &CH->SLOT[SLOT2];
503 	env_out=OPL_CALC_SLOT(SLOT);
504 	if (env_out < (EG_ENT - 1)) {
505 		/* PG */
506 		if (SLOT->vib)
507 			SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
508 		else
509 			SLOT->Cnt += SLOT->Incr;
510 		/* connection */
511 		outd[0] += OP_OUT(SLOT, env_out, feedback2);
512 	}
513 }
514 
515 /* ---------- calcrate rythm block ---------- */
516 #define WHITE_NOISE_db 6.0
OPL_CALC_RH(OPL_CH * CH)517 inline void OPL_CALC_RH(OPL_CH *CH) {
518 	uint32 env_tam;
519 	uint32 env_sd;
520 	uint32 env_top;
521 	uint32 env_hh;
522 	// This code used to do int(OPL->rnd.getRandomBit() * (WHITE_NOISE_db / EG_STEP)),
523 	// but EG_STEP = 96.0/EG_ENT, and WHITE_NOISE_db=6.0. So, that's equivalent to
524 	// int(OPL->rnd.getRandomBit() * EG_ENT/16). We know that EG_ENT is 4096, or 1024,
525 	// or 128, so we can safely avoid any FP ops.
526 	int whitenoise = int((std::rand()&1)*(WHITE_NOISE_db/EG_STEP));
527 
528 	int tone8;
529 
530 	OPL_SLOT *SLOT;
531 	uint32 env_out;
532 
533 	/* BD : same as FM serial mode and output level is large */
534 	feedback2 = 0;
535 	/* SLOT 1 */
536 	SLOT = &CH[6].SLOT[SLOT1];
537 	env_out = OPL_CALC_SLOT(SLOT);
538 	if (env_out < EG_ENT-1) {
539 		/* PG */
540 		if (SLOT->vib)
541 			SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
542 		else
543 			SLOT->Cnt += SLOT->Incr;
544 		/* connection */
545 		if (CH[6].FB) {
546 			int feedback1 = (CH[6].op1_out[0] + CH[6].op1_out[1]) >> CH[6].FB;
547 			CH[6].op1_out[1] = CH[6].op1_out[0];
548 			feedback2 = CH[6].op1_out[0] = OP_OUT(SLOT, env_out, feedback1);
549 		}
550 		else {
551 			feedback2 = OP_OUT(SLOT, env_out, 0);
552 		}
553 	} else {
554 		feedback2 = 0;
555 		CH[6].op1_out[1] = CH[6].op1_out[0];
556 		CH[6].op1_out[0] = 0;
557 	}
558 	/* SLOT 2 */
559 	SLOT = &CH[6].SLOT[SLOT2];
560 	env_out = OPL_CALC_SLOT(SLOT);
561 	if (env_out < EG_ENT-1) {
562 		/* PG */
563 		if (SLOT->vib)
564 			SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
565 		else
566 			SLOT->Cnt += SLOT->Incr;
567 		/* connection */
568 		outd[0] += OP_OUT(SLOT, env_out, feedback2) * 2;
569 	}
570 
571 	// SD  (17) = mul14[fnum7] + white noise
572 	// TAM (15) = mul15[fnum8]
573 	// TOP (18) = fnum6(mul18[fnum8]+whitenoise)
574 	// HH  (14) = fnum7(mul18[fnum8]+whitenoise) + white noise
575 	env_sd = OPL_CALC_SLOT(SLOT7_2) + whitenoise;
576 	env_tam =OPL_CALC_SLOT(SLOT8_1);
577 	env_top = OPL_CALC_SLOT(SLOT8_2);
578 	env_hh = OPL_CALC_SLOT(SLOT7_1) + whitenoise;
579 
580 	/* PG */
581 	if (SLOT7_1->vib)
582 		SLOT7_1->Cnt += (SLOT7_1->Incr * vib) >> (VIB_RATE_SHIFT-1);
583 	else
584 		SLOT7_1->Cnt += 2 * SLOT7_1->Incr;
585 	if (SLOT7_2->vib)
586 		SLOT7_2->Cnt += (CH[7].fc * vib) >> (VIB_RATE_SHIFT-3);
587 	else
588 		SLOT7_2->Cnt += (CH[7].fc * 8);
589 	if (SLOT8_1->vib)
590 		SLOT8_1->Cnt += (SLOT8_1->Incr * vib) >> VIB_RATE_SHIFT;
591 	else
592 		SLOT8_1->Cnt += SLOT8_1->Incr;
593 	if (SLOT8_2->vib)
594 		SLOT8_2->Cnt += ((CH[8].fc * 3) * vib) >> (VIB_RATE_SHIFT-4);
595 	else
596 		SLOT8_2->Cnt += (CH[8].fc * 48);
597 
598 	tone8 = OP_OUT(SLOT8_2,whitenoise,0 );
599 
600 	/* SD */
601 	if (env_sd < (EG_ENT - 1))
602 		outd[0] += OP_OUT(SLOT7_1, env_sd, 0) * 8;
603 	/* TAM */
604 	if (env_tam < (EG_ENT - 1))
605 		outd[0] += OP_OUT(SLOT8_1, env_tam, 0) * 2;
606 	/* TOP-CY */
607 	if (env_top < (EG_ENT - 1))
608 		outd[0] += OP_OUT(SLOT7_2, env_top, tone8) * 2;
609 	/* HH */
610 	if (env_hh  < (EG_ENT-1))
611 		outd[0] += OP_OUT(SLOT7_2, env_hh, tone8) * 2;
612 }
613 
614 /* ----------- initialize time tabls ----------- */
init_timetables(FM_OPL * OPL,int ARRATE,int DRRATE)615 static void init_timetables(FM_OPL *OPL, int ARRATE, int DRRATE) {
616 	/* make attack rate & decay rate tables */
617 	for (int i = 0; i < 4; i++)
618 		OPL->AR_TABLE[i] = OPL->DR_TABLE[i] = 0;
619 	for (int i = 4; i <= 60; i++) {
620 		double rate = OPL->freqbase;						/* frequency rate */
621 		if (i < 60)
622 			rate *= 1.0 + (i & 3) * 0.25;		/* b0-1 : x1 , x1.25 , x1.5 , x1.75 */
623 		rate *= 1 << ((i >> 2) - 1);						/* b2-5 : shift bit */
624 		rate *= static_cast<double>(EG_ENT << ENV_BITS);
625 		OPL->AR_TABLE[i] = static_cast<int>(rate / ARRATE);
626 		OPL->DR_TABLE[i] = static_cast<int>(rate / DRRATE);
627 	}
628 	for (int i = 60; i < 76; i++) {
629 		OPL->AR_TABLE[i] = EG_AED-1;
630 		OPL->DR_TABLE[i] = OPL->DR_TABLE[60];
631 	}
632 }
633 
634 /* ---------- generic table initialize ---------- */
OPLOpenTable()635 static int OPLOpenTable() {
636 	/* allocate dynamic tables */
637 	TL_TABLE = new int[TL_MAX * 2];
638 	SIN_TABLE = new int *[SIN_ENT * 4];
639 	AMS_TABLE = new int[AMS_ENT * 2];
640 	VIB_TABLE = new int[VIB_ENT * 2];
641 	ENV_CURVE = new int[2*EG_ENT+1];
642 	/* make total level table */
643 	for (uint32 t = 0; t < EG_ENT - 1; t++) {
644 		double rate = ((1 << TL_BITS) - 1) / pow(10.0, EG_STEP * t / 20);	/* dB -> voltage */
645 		TL_TABLE[         t] =  static_cast<int>(rate);
646 		TL_TABLE[TL_MAX + t] = -TL_TABLE[t];
647 	}
648 	/* fill volume off area */
649 	for (uint32 t = EG_ENT - 1; t < TL_MAX; t++) {
650 		TL_TABLE[t] = TL_TABLE[TL_MAX + t] = 0;
651 	}
652 
653 	/* make sinwave table (total level offet) */
654 	/* degree 0 = degree 180                   = off */
655 	SIN_TABLE[0] = SIN_TABLE[SIN_ENT /2 ] = &TL_TABLE[EG_ENT - 1];
656 	for (uint32 s = 1; s <= SIN_ENT / 4; s++) {
657 		double pom = sin(2 * M_PI * s / SIN_ENT); /* sin     */
658 		pom = 20 * log10(1 / pom);	   /* decibel */
659 		int j = int(pom / EG_STEP);         /* TL_TABLE steps */
660 
661 		/* degree 0   -  90    , degree 180 -  90 : plus section */
662 		SIN_TABLE[          s] = SIN_TABLE[SIN_ENT / 2 - s] = &TL_TABLE[j];
663 		/* degree 180 - 270    , degree 360 - 270 : minus section */
664 		SIN_TABLE[SIN_ENT / 2 + s] = SIN_TABLE[SIN_ENT - s] = &TL_TABLE[TL_MAX + j];
665 	}
666 	for (uint32 s = 0; s < SIN_ENT; s++) {
667 		SIN_TABLE[SIN_ENT * 1 + s] = s < (SIN_ENT / 2) ? SIN_TABLE[s] : &TL_TABLE[EG_ENT];
668 		SIN_TABLE[SIN_ENT * 2 + s] = SIN_TABLE[s % (SIN_ENT / 2)];
669 		SIN_TABLE[SIN_ENT * 3 + s] = (s / (SIN_ENT / 4)) & 1 ? &TL_TABLE[EG_ENT] : SIN_TABLE[SIN_ENT * 2 + s];
670 	}
671 
672 	/* envelope counter -> envelope output table */
673 	for (uint32 i = 0; i < EG_ENT; i++) {
674 		/* ATTACK curve */
675 		double pom = pow((static_cast<double>(EG_ENT - 1 - i) / EG_ENT), 8) * EG_ENT;
676 		/* if (pom >= EG_ENT) pom = EG_ENT-1; */
677 		ENV_CURVE[i] = static_cast<int>(pom);
678 		/* DECAY ,RELEASE curve */
679 		ENV_CURVE[(EG_DST >> ENV_BITS) + i]= i;
680 	}
681 	/* off */
682 	ENV_CURVE[EG_OFF >> ENV_BITS]= EG_ENT - 1;
683 	/* make LFO ams table */
684 	for (uint32 i = 0; i < AMS_ENT; i++) {
685 		double pom = (1.0 + sin(2 * M_PI * i / AMS_ENT)) / 2; /* sin */
686 		AMS_TABLE[i]         = static_cast<int>((1.0 / EG_STEP) * pom); /* 1dB   */
687 		AMS_TABLE[AMS_ENT + i] = static_cast<int>((4.8 / EG_STEP) * pom); /* 4.8dB */
688 	}
689 	/* make LFO vibrate table */
690 	for (uint32 i = 0; i < VIB_ENT; i++) {
691 		/* 100cent = 1seminote = 6% ?? */
692 		double pom = VIB_RATE * 0.06 * sin(2 * M_PI * i / VIB_ENT); /* +-100sect step */
693 		VIB_TABLE[i]         = static_cast<int>(VIB_RATE + (pom * 0.07)); /* +- 7cent */
694 		VIB_TABLE[VIB_ENT + i] = static_cast<int>(VIB_RATE + (pom * 0.14)); /* +-14cent */
695 	}
696 	return 1;
697 }
698 
OPLCloseTable()699 static void OPLCloseTable() {
700 	delete [] TL_TABLE;
701 	delete [] SIN_TABLE;
702 	delete [] AMS_TABLE;
703 	delete [] VIB_TABLE;
704 	delete [] ENV_CURVE;
705 }
706 
707 /* CSM Key Controll */
CSMKeyControll(OPL_CH * CH)708 inline void CSMKeyControll(OPL_CH *CH) {
709 	OPL_SLOT *slot1 = &CH->SLOT[SLOT1];
710 	OPL_SLOT *slot2 = &CH->SLOT[SLOT2];
711 	/* all key off */
712 	OPL_KEYOFF(slot1);
713 	OPL_KEYOFF(slot2);
714 	/* total level latch */
715 	slot1->TLL = slot1->TL + (CH->ksl_base>>slot1->ksl);
716 	slot1->TLL = slot1->TL + (CH->ksl_base>>slot1->ksl);
717 	/* key on */
718 	CH->op1_out[0] = CH->op1_out[1] = 0;
719 	OPL_KEYON(slot1);
720 	OPL_KEYON(slot2);
721 }
722 
723 /* ---------- opl initialize ---------- */
OPL_initalize(FM_OPL * OPL)724 static void OPL_initalize(FM_OPL *OPL) {
725 	int fn;
726 
727 	/* frequency base */
728 	OPL->freqbase = (OPL->rate) ? (static_cast<double>(OPL->clock) / OPL->rate) / 72  : 0;
729 	/* Timer base time */
730 	OPL->TimerBase = 1.0/(static_cast<double>(OPL->clock) / 72.0 );
731 	/* make time tables */
732 	init_timetables(OPL, OPL_ARRATE, OPL_DRRATE);
733 	/* make fnumber -> increment counter table */
734 	for (fn=0; fn < 1024; fn++) {
735 		OPL->FN_TABLE[fn] = static_cast<uint32>(OPL->freqbase * fn * FREQ_RATE * (1<<7) / 2);
736 	}
737 	/* LFO freq.table */
738 	OPL->amsIncr = static_cast<int>(OPL->rate ? static_cast<double>(AMS_ENT) * (1 << AMS_SHIFT) / OPL->rate * 3.7 * (OPL->clock/3600000.0) : 0);
739 	OPL->vibIncr = static_cast<int>(OPL->rate ? static_cast<double>(VIB_ENT) * (1 << VIB_SHIFT) / OPL->rate * 6.4 * (OPL->clock/3600000.0) : 0);
740 }
741 
742 /* ---------- write a OPL registers ---------- */
OPLWriteReg(FM_OPL * OPL,int r,int v)743 void OPLWriteReg(FM_OPL *OPL, int r, int v) {
744 	OPL_CH *CH;
745 	int slot;
746 	uint32 block_fnum;
747 
748 	switch (r & 0xe0) {
749 	case 0x00: /* 00-1f:controll */
750 		switch (r & 0x1f) {
751 		case 0x01:
752 			/* wave selector enable */
753 			if (OPL->type&OPL_TYPE_WAVESEL) {
754 				OPL->wavesel = v & 0x20;
755 				if (!OPL->wavesel) {
756 					/* preset compatible mode */
757 					int c;
758 					for (c = 0; c < OPL->max_ch; c++) {
759 						OPL->P_CH[c].SLOT[SLOT1].wavetable = &SIN_TABLE[0];
760 						OPL->P_CH[c].SLOT[SLOT2].wavetable = &SIN_TABLE[0];
761 					}
762 				}
763 			}
764 			return;
765 		case 0x02:	/* Timer 1 */
766 			OPL->T[0] = (256-v) * 4;
767 			break;
768 		case 0x03:	/* Timer 2 */
769 			OPL->T[1] = (256-v) * 16;
770 			return;
771 		case 0x04:	/* IRQ clear / mask and Timer enable */
772 			if (v & 0x80) {	/* IRQ flag clear */
773 				OPL_STATUS_RESET(OPL, 0x7f);
774 			} else {	/* set IRQ mask ,timer enable*/
775 				uint8 st1 = v & 1;
776 				uint8 st2 = (v >> 1) & 1;
777 				/* IRQRST,T1MSK,t2MSK,EOSMSK,BRMSK,x,ST2,ST1 */
778 				OPL_STATUS_RESET(OPL, v & 0x78);
779 				OPL_STATUSMASK_SET(OPL,((~v) & 0x78) | 0x01);
780 				/* timer 2 */
781 				if (OPL->st[1] != st2) {
782 					double interval = st2 ? (OPL->T[1] * OPL->TimerBase) : 0.0;
783 					OPL->st[1] = st2;
784 					if (OPL->TimerHandler) (OPL->TimerHandler)(OPL->TimerParam + 1, interval);
785 				}
786 				/* timer 1 */
787 				if (OPL->st[0] != st1) {
788 					double interval = st1 ? (OPL->T[0] * OPL->TimerBase) : 0.0;
789 					OPL->st[0] = st1;
790 					if (OPL->TimerHandler) (OPL->TimerHandler)(OPL->TimerParam + 0, interval);
791 				}
792 			}
793 			return;
794 		}
795 		break;
796 	case 0x20:	/* am,vib,ksr,eg type,mul */
797 		slot = slot_array[r&0x1f];
798 		if (slot == -1)
799 			return;
800 		set_mul(OPL,slot,v);
801 		return;
802 	case 0x40:
803 		slot = slot_array[r&0x1f];
804 		if (slot == -1)
805 			return;
806 		set_ksl_tl(OPL,slot,v);
807 		return;
808 	case 0x60:
809 		slot = slot_array[r&0x1f];
810 		if (slot == -1)
811 			return;
812 		set_ar_dr(OPL,slot,v);
813 		return;
814 	case 0x80:
815 		slot = slot_array[r&0x1f];
816 		if (slot == -1)
817 			return;
818 		set_sl_rr(OPL,slot,v);
819 		return;
820 	case 0xa0:
821 		switch (r) {
822 		case 0xbd:
823 			/* amsep,vibdep,r,bd,sd,tom,tc,hh */
824 			{
825 			uint8 rkey = OPL->rythm ^ v;
826 			OPL->ams_table = &AMS_TABLE[v & 0x80 ? AMS_ENT : 0];
827 			OPL->vib_table = &VIB_TABLE[v & 0x40 ? VIB_ENT : 0];
828 			OPL->rythm  = v & 0x3f;
829 			if (OPL->rythm & 0x20) {
830 				/* BD key on/off */
831 				if (rkey & 0x10) {
832 					if (v & 0x10) {
833 						OPL->P_CH[6].op1_out[0] = OPL->P_CH[6].op1_out[1] = 0;
834 						OPL_KEYON(&OPL->P_CH[6].SLOT[SLOT1]);
835 						OPL_KEYON(&OPL->P_CH[6].SLOT[SLOT2]);
836 					} else {
837 						OPL_KEYOFF(&OPL->P_CH[6].SLOT[SLOT1]);
838 						OPL_KEYOFF(&OPL->P_CH[6].SLOT[SLOT2]);
839 					}
840 				}
841 				/* SD key on/off */
842 				if (rkey & 0x08) {
843 					if (v & 0x08)
844 						OPL_KEYON(&OPL->P_CH[7].SLOT[SLOT2]);
845 					else
846 						OPL_KEYOFF(&OPL->P_CH[7].SLOT[SLOT2]);
847 				}/* TAM key on/off */
848 				if (rkey & 0x04) {
849 					if (v & 0x04)
850 						OPL_KEYON(&OPL->P_CH[8].SLOT[SLOT1]);
851 					else
852 						OPL_KEYOFF(&OPL->P_CH[8].SLOT[SLOT1]);
853 				}
854 				/* TOP-CY key on/off */
855 				if (rkey & 0x02) {
856 					if (v & 0x02)
857 						OPL_KEYON(&OPL->P_CH[8].SLOT[SLOT2]);
858 					else
859 						OPL_KEYOFF(&OPL->P_CH[8].SLOT[SLOT2]);
860 				}
861 				/* HH key on/off */
862 				if (rkey & 0x01) {
863 					if (v & 0x01)
864 						OPL_KEYON(&OPL->P_CH[7].SLOT[SLOT1]);
865 					else
866 						OPL_KEYOFF(&OPL->P_CH[7].SLOT[SLOT1]);
867 				}
868 			}
869 			}
870 			return;
871 
872 		default:
873 			break;
874 		}
875 		/* keyon,block,fnum */
876 		if ((r & 0x0f) > 8)
877 			return;
878 		CH = &OPL->P_CH[r & 0x0f];
879 		if (!(r&0x10)) {	/* a0-a8 */
880 			block_fnum  = (CH->block_fnum & 0x1f00) | v;
881 		} else {	/* b0-b8 */
882 			int keyon = (v >> 5) & 1;
883 			block_fnum = ((v & 0x1f) << 8) | (CH->block_fnum & 0xff);
884 			if (CH->keyon != keyon) {
885 				if ((CH->keyon=keyon)) {
886 					CH->op1_out[0] = CH->op1_out[1] = 0;
887 					OPL_KEYON(&CH->SLOT[SLOT1]);
888 					OPL_KEYON(&CH->SLOT[SLOT2]);
889 				} else {
890 					OPL_KEYOFF(&CH->SLOT[SLOT1]);
891 					OPL_KEYOFF(&CH->SLOT[SLOT2]);
892 				}
893 			}
894 		}
895 		/* update */
896 		if (CH->block_fnum != block_fnum) {
897 			int blockRv = 7 - (block_fnum >> 10);
898 			int fnum = block_fnum & 0x3ff;
899 			CH->block_fnum = block_fnum;
900 			CH->ksl_base = KSL_TABLE[block_fnum >> 6];
901 			CH->fc = OPL->FN_TABLE[fnum] >> blockRv;
902 			CH->kcode = CH->block_fnum >> 9;
903 			if ((OPL->mode & 0x40) && CH->block_fnum & 0x100)
904 				CH->kcode |=1;
905 			CALC_FCSLOT(CH,&CH->SLOT[SLOT1]);
906 			CALC_FCSLOT(CH,&CH->SLOT[SLOT2]);
907 		}
908 		return;
909 	case 0xc0:
910 		/* FB,C */
911 		if ((r & 0x0f) > 8)
912 			return;
913 		CH = &OPL->P_CH[r&0x0f];
914 		{
915 			int feedback = (v >> 1) & 7;
916 			CH->FB = feedback ? (8 + 1) - feedback : 0;
917 			CH->CON = v & 1;
918 			set_algorythm(CH);
919 		}
920 		return;
921 	case 0xe0: /* wave type */
922 		slot = slot_array[r & 0x1f];
923 		if (slot == -1)
924 			return;
925 		CH = &OPL->P_CH[slot>>1];
926 		if (OPL->wavesel) {
927 			CH->SLOT[slot&1].wavetable = &SIN_TABLE[(v & 0x03) * SIN_ENT];
928 		}
929 		return;
930 	}
931 }
932 
933 /* lock/unlock for common table */
OPL_LockTable()934 static int OPL_LockTable() {
935 	num_lock++;
936 	if (num_lock>1)
937 		return 0;
938 	/* first time */
939 	cur_chip = nullptr;
940 	/* allocate total level table (128kb space) */
941 	if (!OPLOpenTable()) {
942 		num_lock--;
943 		return -1;
944 	}
945 	return 0;
946 }
947 
OPL_UnLockTable()948 static void OPL_UnLockTable() {
949 	if (num_lock)
950 		num_lock--;
951 	if (num_lock)
952 		return;
953 	/* last time */
954 	cur_chip = nullptr;
955 	OPLCloseTable();
956 }
957 
958 /*******************************************************************************/
959 /*		YM3812 local section                                                   */
960 /*******************************************************************************/
961 
962 /* ---------- update one of chip ----------- */
YM3812UpdateOne_Mono(FM_OPL * OPL,sint16 * buffer,int length)963 void YM3812UpdateOne_Mono(FM_OPL *OPL, sint16 *buffer, int length) {
964 	sint16 *buf = buffer;
965 	uint32 amsCnt = OPL->amsCnt;
966 	uint32 vibCnt = OPL->vibCnt;
967 	uint8 rythm = OPL->rythm & 0x20;
968 
969 	if (OPL != cur_chip) {
970 		cur_chip = OPL;
971 		/* channel pointers */
972 		S_CH = OPL->P_CH;
973 		E_CH = &S_CH[9];
974 		/* rythm slot */
975 		SLOT7_1 = &S_CH[7].SLOT[SLOT1];
976 		SLOT7_2 = &S_CH[7].SLOT[SLOT2];
977 		SLOT8_1 = &S_CH[8].SLOT[SLOT1];
978 		SLOT8_2 = &S_CH[8].SLOT[SLOT2];
979 		/* LFO state */
980 		amsIncr = OPL->amsIncr;
981 		vibIncr = OPL->vibIncr;
982 		ams_table = OPL->ams_table;
983 		vib_table = OPL->vib_table;
984 	}
985 	OPL_CH *R_CH = rythm ? &S_CH[6] : E_CH;
986 	for (int i = 0; i < length; i++) {
987 		/*            channel A         channel B         channel C      */
988 		/* LFO */
989 		ams = ams_table[(amsCnt += amsIncr) >> AMS_SHIFT];
990 		vib = vib_table[(vibCnt += vibIncr) >> VIB_SHIFT];
991 		outd[0] = 0;
992 		/* FM part */
993 		for (OPL_CH *CH = S_CH; CH < R_CH; CH++)
994 			OPL_CALC_CH(CH);
995 		/* Rythn part */
996 		if (rythm)
997 			OPL_CALC_RH(S_CH);
998 		/* limit check */
999 		int data = CLIP(outd[0], OPL_MINOUT, OPL_MAXOUT);
1000 		/* store to sound buffer */
1001 		buf[i] = data >> OPL_OUTSB;
1002 	}
1003 
1004 	OPL->amsCnt = amsCnt;
1005 	OPL->vibCnt = vibCnt;
1006 }
1007 
YM3812UpdateOne_Stereo(FM_OPL * OPL,sint16 * buffer,int length)1008 void YM3812UpdateOne_Stereo(FM_OPL *OPL, sint16 *buffer, int length) {
1009 	sint16 *buf = buffer;
1010 	uint32 amsCnt = OPL->amsCnt;
1011 	uint32 vibCnt = OPL->vibCnt;
1012 	uint8 rythm = OPL->rythm & 0x20;
1013 
1014 	if (OPL != cur_chip) {
1015 		cur_chip = OPL;
1016 		/* channel pointers */
1017 		S_CH = OPL->P_CH;
1018 		E_CH = &S_CH[9];
1019 		/* rythm slot */
1020 		SLOT7_1 = &S_CH[7].SLOT[SLOT1];
1021 		SLOT7_2 = &S_CH[7].SLOT[SLOT2];
1022 		SLOT8_1 = &S_CH[8].SLOT[SLOT1];
1023 		SLOT8_2 = &S_CH[8].SLOT[SLOT2];
1024 		/* LFO state */
1025 		amsIncr = OPL->amsIncr;
1026 		vibIncr = OPL->vibIncr;
1027 		ams_table = OPL->ams_table;
1028 		vib_table = OPL->vib_table;
1029 	}
1030 	OPL_CH *R_CH = rythm ? &S_CH[6] : E_CH;
1031 	for (int i = 0; i < length; i++) {
1032 		/*            channel A         channel B         channel C      */
1033 		/* LFO */
1034 		ams = ams_table[(amsCnt += amsIncr) >> AMS_SHIFT];
1035 		vib = vib_table[(vibCnt += vibIncr) >> VIB_SHIFT];
1036 		int left = 0;
1037 		int right = 0;
1038 		/* FM part */
1039 		for(OPL_CH *CH = S_CH; CH < R_CH; CH++) {
1040 			outd[0] = 0;
1041 			OPL_CALC_CH(CH);
1042 			if (CH->PAN <= 64)
1043 				left += outd[0];
1044 			else
1045 				left += (outd[0]>>6)*(127-CH->PAN);
1046 			if (CH->PAN >= 64)
1047 				right += outd[0];
1048 			else
1049 				right += (outd[0]>>6)*(CH->PAN);
1050 		}
1051 		/* Rythn part */
1052 		if (rythm) {
1053 			outd[0] = 0;
1054 			OPL_CALC_RH(S_CH);
1055 			left += outd[0];
1056 			right += outd[0];
1057 		}
1058 		/* limit check */
1059 		int data = CLIP(left , OPL_MINOUT, OPL_MAXOUT);
1060 		/* store to sound buffer */
1061 		buf[i * 2] = data >> OPL_OUTSB;
1062 
1063 		/* limit check */
1064 		data = CLIP(right, OPL_MINOUT, OPL_MAXOUT);
1065 		/* store to sound buffer */
1066 		buf[i * 2+1] = data >> OPL_OUTSB;
1067 	}
1068 
1069 	OPL->amsCnt = amsCnt;
1070 	OPL->vibCnt = vibCnt;
1071 }
1072 
1073 /* ---------- reset a chip ---------- */
OPLResetChip(FM_OPL * OPL)1074 void OPLResetChip(FM_OPL *OPL) {
1075 	int c;
1076 	int s;
1077 	int i;
1078 
1079 	/* reset chip */
1080 	OPL->mode = 0;	/* normal mode */
1081 	OPL_STATUS_RESET(OPL, 0x7f);
1082 	/* reset with register write */
1083 	OPLWriteReg(OPL, 0x01,0); /* wabesel disable */
1084 	OPLWriteReg(OPL, 0x02,0); /* Timer1 */
1085 	OPLWriteReg(OPL, 0x03,0); /* Timer2 */
1086 	OPLWriteReg(OPL, 0x04,0); /* IRQ mask clear */
1087 	for (i = 0xff; i >= 0x20; i--)
1088 		OPLWriteReg(OPL,i,0);
1089 	/* reset OPerator parameter */
1090 	for (c = 0; c < OPL->max_ch; c++) {
1091 		OPL_CH *CH = &OPL->P_CH[c];
1092 		OPL->P_CH[c].PAN = 64;
1093 		for (s = 0; s < 2; s++) {
1094 			/* wave table */
1095 			CH->SLOT[s].wavetable = &SIN_TABLE[0];
1096 			/* CH->SLOT[s].evm = ENV_MOD_RR; */
1097 			CH->SLOT[s].evc = EG_OFF;
1098 			CH->SLOT[s].eve = EG_OFF + 1;
1099 			CH->SLOT[s].evs = 0;
1100 		}
1101 	}
1102 }
1103 
1104 /* ----------  Create a virtual YM3812 ----------       */
1105 /* 'rate'  is sampling rate and 'bufsiz' is the size of the  */
OPLCreate(int type,int clock,int rate)1106 FM_OPL *OPLCreate(int type, int clock, int rate) {
1107 	if (OPL_LockTable() == -1)
1108 		return nullptr;
1109 
1110 	auto *OPL = new FM_OPL{};
1111 	OPL->P_CH = OPL->channels;
1112 
1113 	/* set channel state pointer */
1114 	OPL->type  = type;
1115 	OPL->clock = clock;
1116 	OPL->rate  = rate;
1117 	OPL->max_ch = max_opl_channels;
1118 
1119 	/* init grobal tables */
1120 	OPL_initalize(OPL);
1121 
1122 	/* reset chip */
1123 	OPLResetChip(OPL);
1124 	return OPL;
1125 }
1126 
1127 /* ----------  Destroy one of virtual YM3812 ----------       */
OPLDestroy(FM_OPL * OPL)1128 void OPLDestroy(FM_OPL *OPL) {
1129 	OPL_UnLockTable();
1130 	delete OPL;
1131 }
1132 
1133 /* ----------  Option handlers ----------       */
OPLSetTimerHandler(FM_OPL * OPL,OPL_TIMERHANDLER TimerHandler,int channelOffset)1134 void OPLSetTimerHandler(FM_OPL *OPL, OPL_TIMERHANDLER TimerHandler,int channelOffset) {
1135 	OPL->TimerHandler   = TimerHandler;
1136 	OPL->TimerParam = channelOffset;
1137 }
1138 
OPLSetIRQHandler(FM_OPL * OPL,OPL_IRQHANDLER IRQHandler,int param)1139 void OPLSetIRQHandler(FM_OPL *OPL, OPL_IRQHANDLER IRQHandler, int param) {
1140 	OPL->IRQHandler     = IRQHandler;
1141 	OPL->IRQParam = param;
1142 }
1143 
OPLSetUpdateHandler(FM_OPL * OPL,OPL_UPDATEHANDLER UpdateHandler,int param)1144 void OPLSetUpdateHandler(FM_OPL *OPL, OPL_UPDATEHANDLER UpdateHandler,int param) {
1145 	OPL->UpdateHandler = UpdateHandler;
1146 	OPL->UpdateParam = param;
1147 }
1148 
1149 /* ---------- YM3812 I/O interface ---------- */
OPLWrite(FM_OPL * OPL,int a,int v)1150 int OPLWrite(FM_OPL *OPL,int a,int v) {
1151 	if (!(a & 1)) {	/* address port */
1152 		OPL->address = v & 0xff;
1153 	} else {	/* data port */
1154 		if (OPL->UpdateHandler)
1155 			OPL->UpdateHandler(OPL->UpdateParam,0);
1156 		OPLWriteReg(OPL, OPL->address,v);
1157 	}
1158 	return OPL->status >> 7;
1159 }
1160 
OPLRead(FM_OPL * OPL,int a)1161 unsigned char OPLRead(FM_OPL *OPL,int a) {
1162 	if (!(a & 1)) {	/* status port */
1163 		return OPL->status & (OPL->statusmask | 0x80);
1164 	}
1165 	/* data port */
1166 	switch (OPL->address) {
1167 	case 0x05: /* KeyBoard IN */
1168 		PERR(("OPL:read unmapped KEYBOARD port\n"));
1169 		return 0;
1170 	case 0x19: /* I/O DATA    */
1171 		PERR(("OPL:read unmapped I/O port\n"));
1172 		return 0;
1173 	case 0x1a: /* PCM-DATA    */
1174 		return 0;
1175 	default:
1176 		break;
1177 	}
1178 	return 0;
1179 }
1180 
OPLTimerOver(FM_OPL * OPL,int c)1181 int OPLTimerOver(FM_OPL *OPL, int c) {
1182 	if (c) {	/* Timer B */
1183 		OPL_STATUS_SET(OPL, 0x20);
1184 	} else {	/* Timer A */
1185 		OPL_STATUS_SET(OPL, 0x40);
1186 		/* CSM mode key,TL controll */
1187 		if (OPL->mode & 0x80) {	/* CSM mode total level latch and auto key on */
1188 			int ch;
1189 			if (OPL->UpdateHandler)
1190 				OPL->UpdateHandler(OPL->UpdateParam,0);
1191 			for (ch = 0; ch < 9; ch++)
1192 				CSMKeyControll(&OPL->P_CH[ch]);
1193 		}
1194 	}
1195 	/* reload timer */
1196 	if (OPL->TimerHandler)
1197 		(OPL->TimerHandler)(OPL->TimerParam + c, static_cast<double>(OPL->T[c]) * OPL->TimerBase);
1198 	return OPL->status >> 7;
1199 }
1200 
OPLSetPan(FM_OPL * OPL,int c,int pan)1201 void OPLSetPan(FM_OPL *OPL, int c, int pan) {
1202 	if (c > 0 && c < OPL->max_ch)
1203 		OPL->P_CH[c].PAN = pan;
1204 }
1205 
makeAdLibOPL(int rate)1206 FM_OPL *makeAdLibOPL(int rate) {
1207 	// We need to emulate one YM3812 chip
1208 	OPLBuildTables(FMOPL_ENV_BITS_HQ, FMOPL_EG_ENT_HQ);
1209 	return OPLCreate(OPL_TYPE_YM3812, 3579545, rate);
1210 }
1211 
1212 }
1213 
1214 #endif //USE_FMOPL_MIDI
1215 
1216