src/midi.c

   1 /* midi.c
   2  *
   3  * Adlib OPL2/OPL3 FM synthesizer chipset test program.
   4  * Play MIDI file using the OPLx synthesizer (well, poorly anyway)
   5  * (C) 2010-2012 Jonathan Campbell.
   6  * Hackipedia DOS library.
   7  *
   8  * This code is licensed under the LGPL.
   9  * <insert LGPL legal text here>
  10  *
  11  * Compiles for intended target environments:
  12  *   - MS-DOS [pure DOS mode, or Windows or OS/2 DOS Box]
  13  */
  14
  15 #include <stdio.h>
  16 #include <conio.h> /* this is where Open Watcom hides the outp() etc. functions */
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <unistd.h>
  20 #include <malloc.h>
  21 #include <ctype.h>
  22 #include <fcntl.h>
  23 #include <math.h>
  24 #include <dos.h>
  25
  26 #include "src/lib/doslib/vga.h"
  27 #include "src/lib/doslib/dos.h"
  28 #include "src/lib/doslib/8254.h"                /* 8254 timer */
  29 #include "src/lib/doslib/8259.h"
  30 #include "src/lib/doslib/vgagui.h"
  31 #include "src/lib/doslib/vgatty.h"
  32 #include "src/lib/doslib/adlib.h"
  33
  34 /* one per OPL channel */
  35 struct midi_note {
  36         unsigned char           note_number;
  37         unsigned char           note_velocity;
  38         unsigned char           note_track;     /* from what MIDI track */
  39         unsigned char           note_channel;   /* from what MIDI channel */
  40         unsigned int            busy:1;         /* if occupied */
  41 };
  42
  43 struct midi_channel {
  44         unsigned char           program;
  45 };
  46
  47 struct midi_track {
  48         /* track data, raw */
  49         unsigned char*          raw;            /* raw data base */
  50         unsigned char*          fence;          /* raw data end (last byte + 1) */
  51         unsigned char*          read;           /* raw data read ptr */
  52         /* state */
  53         unsigned long           us_per_quarter_note; /* Microseconds per quarter note (def 120 BPM) */
  54         unsigned long           us_tick_cnt_mtpq; /* Microseconds advanced (up to 10000 us or one unit at 100Hz) x ticks per quarter note */
  55         unsigned long           wait;
  56         unsigned char           last_status;    /* MIDI last status byte */
  57         unsigned int            eof:1;          /* we hit the end of the track */
  58 };
  59
  60 #define MIDI_MAX_CHANNELS       16
  61 #define MIDI_MAX_TRACKS         64
  62
  63 struct midi_note                midi_notes[ADLIB_FM_VOICES];
  64 struct midi_channel             midi_ch[MIDI_MAX_CHANNELS];
  65 struct midi_track               midi_trk[MIDI_MAX_TRACKS];
  66 static unsigned int             midi_trk_count=0;
  67 static volatile unsigned char   midi_playing=0;
  68
  69 /* MIDI params. Nobody ever said it was a straightforward standard!
  70  * NTS: These are for reading reference. Internally we convert everything to 100Hz time base. */
  71 static unsigned int ticks_per_quarter_note=0;   /* "Ticks per beat" */
  72
  73 static void (interrupt *old_irq0)();
  74 static volatile unsigned long irq0_ticks=0;
  75 static volatile unsigned int irq0_cnt=0,irq0_add=0,irq0_max=0;
  76
  77 #if TARGET_MSDOS == 16 && (defined(__LARGE__) || defined(__COMPACT__))
  78 static inline unsigned long farptr2phys(unsigned char far *p) { /* take 16:16 pointer convert to physical memory address */
  79         return ((unsigned long)FP_SEG(p) << 4UL) + ((unsigned long)FP_OFF(p));
  80 }
  81 #endif
  82
  83 static inline unsigned char midi_trk_read(struct midi_track *t) {
  84         unsigned char c;
  85
  86         /* NTS: 16-bit large/compact builds MUST compare pointers as unsigned long to compare FAR pointers correctly! */
  87         if (t->read == NULL || (unsigned long)t->read >= (unsigned long)t->fence) {
  88                 t->eof = 1;
  89                 return 0xFF;
  90         }
  91
  92         c = *(t->read);
  93 #if TARGET_MSDOS == 16 && (defined(__LARGE__) || defined(__COMPACT__))
  94         if (FP_OFF(t->read) >= 0xF) /* 16:16 far pointer aware (NTS: Programs reassigning this pointer MUST normalize the FAR pointer) */
  95                 t->read = MK_FP(FP_SEG(t->read)+0x1,0);
  96         else
  97                 t->read++;
  98 #else
  99         t->read++;
 100 #endif
 101         return c;
 102 }
 103
 104 void midi_trk_end(struct midi_track *t) {
 105         t->wait = ~0UL;
 106         t->read = t->fence;
 107 }
 108
 109 void midi_trk_skip(struct midi_track *t,unsigned long len) {
 110         unsigned long rem;
 111
 112         /* NTS: 16-bit large/compact builds MUST compare pointers as unsigned long to compare FAR pointers correctly! */
 113         if (t->read == NULL || (unsigned long)t->read >= (unsigned long)t->fence)
 114                 return;
 115
 116         if (len > 0xFFF0UL) {
 117                 midi_trk_end(t);
 118                 return;
 119         }
 120 #if TARGET_MSDOS == 16 && (defined(__LARGE__) || defined(__COMPACT__))
 121         {
 122                 unsigned long tt;
 123
 124                 tt = farptr2phys(t->read);
 125                 rem = farptr2phys(t->fence) - tt;
 126                 if (rem > len) rem = len;
 127                 tt += rem;
 128                 t->read = MK_FP(tt>>4,tt&0xF);
 129         }
 130 #else
 131         rem = (unsigned long)(t->fence - t->read);
 132         if (len > rem) len = rem;
 133         t->read += len;
 134 #endif
 135 }
 136
 137 static const uint32_t midikeys_freqs[0x80] = {
 138         0x00082d01,     /* key 0 = 8.17579891564371Hz */
 139         0x0008a976,     /* key 1 = 8.66195721802725Hz */
 140         0x00092d51,     /* key 2 = 9.17702399741899Hz */
 141         0x0009b904,     /* key 3 = 9.72271824131503Hz */
 142         0x000a4d05,     /* key 4 = 10.3008611535272Hz */
 143         0x000ae9d3,     /* key 5 = 10.9133822322814Hz */
 144         0x000b8ff4,     /* key 6 = 11.5623257097386Hz */
 145         0x000c3ff6,     /* key 7 = 12.2498573744297Hz */
 146         0x000cfa70,     /* key 8 = 12.9782717993733Hz */
 147         0x000dc000,     /* key 9 = 13.75Hz */
 148         0x000e914f,     /* key 10 = 14.5676175474403Hz */
 149         0x000f6f11,     /* key 11 = 15.4338531642539Hz */
 150         0x00105a02,     /* key 12 = 16.3515978312874Hz */
 151         0x001152ec,     /* key 13 = 17.3239144360545Hz */
 152         0x00125aa2,     /* key 14 = 18.354047994838Hz */
 153         0x00137208,     /* key 15 = 19.4454364826301Hz */
 154         0x00149a0a,     /* key 16 = 20.6017223070544Hz */
 155         0x0015d3a6,     /* key 17 = 21.8267644645627Hz */
 156         0x00171fe9,     /* key 18 = 23.1246514194771Hz */
 157         0x00187fed,     /* key 19 = 24.4997147488593Hz */
 158         0x0019f4e0,     /* key 20 = 25.9565435987466Hz */
 159         0x001b8000,     /* key 21 = 27.5Hz */
 160         0x001d229e,     /* key 22 = 29.1352350948806Hz */
 161         0x001ede22,     /* key 23 = 30.8677063285078Hz */
 162         0x0020b404,     /* key 24 = 32.7031956625748Hz */
 163         0x0022a5d8,     /* key 25 = 34.647828872109Hz */
 164         0x0024b545,     /* key 26 = 36.7080959896759Hz */
 165         0x0026e410,     /* key 27 = 38.8908729652601Hz */
 166         0x00293414,     /* key 28 = 41.2034446141087Hz */
 167         0x002ba74d,     /* key 29 = 43.6535289291255Hz */
 168         0x002e3fd2,     /* key 30 = 46.2493028389543Hz */
 169         0x0030ffda,     /* key 31 = 48.9994294977187Hz */
 170         0x0033e9c0,     /* key 32 = 51.9130871974931Hz */
 171         0x00370000,     /* key 33 = 55Hz */
 172         0x003a453d,     /* key 34 = 58.2704701897612Hz */
 173         0x003dbc44,     /* key 35 = 61.7354126570155Hz */
 174         0x00416809,     /* key 36 = 65.4063913251497Hz */
 175         0x00454bb0,     /* key 37 = 69.295657744218Hz */
 176         0x00496a8b,     /* key 38 = 73.4161919793519Hz */
 177         0x004dc820,     /* key 39 = 77.7817459305202Hz */
 178         0x00526829,     /* key 40 = 82.4068892282175Hz */
 179         0x00574e9b,     /* key 41 = 87.307057858251Hz */
 180         0x005c7fa4,     /* key 42 = 92.4986056779086Hz */
 181         0x0061ffb5,     /* key 43 = 97.9988589954373Hz */
 182         0x0067d380,     /* key 44 = 103.826174394986Hz */
 183         0x006e0000,     /* key 45 = 110Hz */
 184         0x00748a7b,     /* key 46 = 116.540940379522Hz */
 185         0x007b7888,     /* key 47 = 123.470825314031Hz */
 186         0x0082d012,     /* key 48 = 130.812782650299Hz */
 187         0x008a9760,     /* key 49 = 138.591315488436Hz */
 188         0x0092d517,     /* key 50 = 146.832383958704Hz */
 189         0x009b9041,     /* key 51 = 155.56349186104Hz */
 190         0x00a4d053,     /* key 52 = 164.813778456435Hz */
 191         0x00ae9d36,     /* key 53 = 174.614115716502Hz */
 192         0x00b8ff49,     /* key 54 = 184.997211355817Hz */
 193         0x00c3ff6a,     /* key 55 = 195.997717990875Hz */
 194         0x00cfa700,     /* key 56 = 207.652348789973Hz */
 195         0x00dc0000,     /* key 57 = 220Hz */
 196         0x00e914f6,     /* key 58 = 233.081880759045Hz */
 197         0x00f6f110,     /* key 59 = 246.941650628062Hz */
 198         0x0105a025,     /* key 60 = 261.625565300599Hz */
 199         0x01152ec0,     /* key 61 = 277.182630976872Hz */
 200         0x0125aa2e,     /* key 62 = 293.664767917408Hz */
 201         0x01372082,     /* key 63 = 311.126983722081Hz */
 202         0x0149a0a7,     /* key 64 = 329.62755691287Hz */
 203         0x015d3a6d,     /* key 65 = 349.228231433004Hz */
 204         0x0171fe92,     /* key 66 = 369.994422711634Hz */
 205         0x0187fed4,     /* key 67 = 391.995435981749Hz */
 206         0x019f4e00,     /* key 68 = 415.304697579945Hz */
 207         0x01b80000,     /* key 69 = 440Hz */
 208         0x01d229ec,     /* key 70 = 466.16376151809Hz */
 209         0x01ede220,     /* key 71 = 493.883301256124Hz */
 210         0x020b404a,     /* key 72 = 523.251130601197Hz */
 211         0x022a5d81,     /* key 73 = 554.365261953744Hz */
 212         0x024b545c,     /* key 74 = 587.329535834815Hz */
 213         0x026e4104,     /* key 75 = 622.253967444162Hz */
 214         0x0293414f,     /* key 76 = 659.25511382574Hz */
 215         0x02ba74da,     /* key 77 = 698.456462866008Hz */
 216         0x02e3fd24,     /* key 78 = 739.988845423269Hz */
 217         0x030ffda9,     /* key 79 = 783.990871963499Hz */
 218         0x033e9c01,     /* key 80 = 830.60939515989Hz */
 219         0x03700000,     /* key 81 = 880Hz */
 220         0x03a453d8,     /* key 82 = 932.32752303618Hz */
 221         0x03dbc440,     /* key 83 = 987.766602512248Hz */
 222         0x04168094,     /* key 84 = 1046.50226120239Hz */
 223         0x0454bb03,     /* key 85 = 1108.73052390749Hz */
 224         0x0496a8b8,     /* key 86 = 1174.65907166963Hz */
 225         0x04dc8208,     /* key 87 = 1244.50793488832Hz */
 226         0x0526829e,     /* key 88 = 1318.51022765148Hz */
 227         0x0574e9b5,     /* key 89 = 1396.91292573202Hz */
 228         0x05c7fa49,     /* key 90 = 1479.97769084654Hz */
 229         0x061ffb53,     /* key 91 = 1567.981743927Hz */
 230         0x067d3802,     /* key 92 = 1661.21879031978Hz */
 231         0x06e00000,     /* key 93 = 1760Hz */
 232         0x0748a7b1,     /* key 94 = 1864.65504607236Hz */
 233         0x07b78880,     /* key 95 = 1975.5332050245Hz */
 234         0x082d0128,     /* key 96 = 2093.00452240479Hz */
 235         0x08a97607,     /* key 97 = 2217.46104781498Hz */
 236         0x092d5171,     /* key 98 = 2349.31814333926Hz */
 237         0x09b90410,     /* key 99 = 2489.01586977665Hz */
 238         0x0a4d053c,     /* key 100 = 2637.02045530296Hz */
 239         0x0ae9d36b,     /* key 101 = 2793.82585146403Hz */
 240         0x0b8ff493,     /* key 102 = 2959.95538169308Hz */
 241         0x0c3ff6a7,     /* key 103 = 3135.96348785399Hz */
 242         0x0cfa7005,     /* key 104 = 3322.43758063956Hz */
 243         0x0dc00000,     /* key 105 = 3520Hz */
 244         0x0e914f62,     /* key 106 = 3729.31009214472Hz */
 245         0x0f6f1100,     /* key 107 = 3951.06641004899Hz */
 246         0x105a0250,     /* key 108 = 4186.00904480958Hz */
 247         0x1152ec0e,     /* key 109 = 4434.92209562995Hz */
 248         0x125aa2e3,     /* key 110 = 4698.63628667852Hz */
 249         0x13720820,     /* key 111 = 4978.03173955329Hz */
 250         0x149a0a79,     /* key 112 = 5274.04091060592Hz */
 251         0x15d3a6d6,     /* key 113 = 5587.65170292806Hz */
 252         0x171fe927,     /* key 114 = 5919.91076338615Hz */
 253         0x187fed4e,     /* key 115 = 6271.92697570799Hz */
 254         0x19f4e00a,     /* key 116 = 6644.87516127912Hz */
 255         0x1b800000,     /* key 117 = 7040Hz */
 256         0x1d229ec4,     /* key 118 = 7458.62018428944Hz */
 257         0x1ede2200,     /* key 119 = 7902.13282009799Hz */
 258         0x20b404a1,     /* key 120 = 8372.01808961916Hz */
 259         0x22a5d81c,     /* key 121 = 8869.84419125991Hz */
 260         0x24b545c7,     /* key 122 = 9397.27257335704Hz */
 261         0x26e41040,     /* key 123 = 9956.06347910659Hz */
 262         0x293414f2,     /* key 124 = 10548.0818212118Hz */
 263         0x2ba74dac,     /* key 125 = 11175.3034058561Hz */
 264         0x2e3fd24f,     /* key 126 = 11839.8215267723Hz */
 265         0x30ffda9c      /* key 127 = 12543.853951416Hz */
 266 };
 267
 268 static uint32_t midi_note_freq(struct midi_channel *ch,unsigned char key) {
 269         return midikeys_freqs[key&0x7F];
 270 }
 271
 272 static struct midi_note *get_fm_note(struct midi_track *t,struct midi_channel *ch,unsigned char key,unsigned char do_alloc) {
 273         unsigned int tch = (unsigned int)(t - midi_trk); /* pointer math */
 274         unsigned int ach = (unsigned int)(ch - midi_ch); /* pointer math */
 275         unsigned int i,freen=~0;
 276
 277         for (i=0;i < ADLIB_FM_VOICES;i++) {
 278                 if (midi_notes[i].busy) {
 279                         if (midi_notes[i].note_channel == ach && midi_notes[i].note_track == tch && midi_notes[i].note_number == key)
 280                                 return &midi_notes[i];
 281                 }
 282                 else {
 283                         if (freen == ~0) freen = i;
 284                 }
 285         }
 286
 287         if (do_alloc && freen != ~0) return &midi_notes[freen];
 288         return NULL;
 289 }
 290
 291 static void drop_fm_note(struct midi_channel *ch,unsigned char key) {
 292         unsigned int ach = (unsigned int)(ch - midi_ch); /* pointer math */
 293         unsigned int i;
 294
 295         for (i=0;i < ADLIB_FM_VOICES;i++) {
 296                 if (midi_notes[i].busy && midi_notes[i].note_channel == ach) {
 297                         midi_notes[i].busy = 0;
 298                         break;
 299                 }
 300         }
 301 }
 302
 303 static inline void on_key_aftertouch(struct midi_track *t,struct midi_channel *ch,unsigned char key,unsigned char vel) {
 304         struct midi_note *note = get_fm_note(t,ch,key,/*do_alloc*/0);
 305         uint32_t freq = midi_note_freq(ch,key);
 306         unsigned int ach;
 307
 308         if (note == NULL) return;
 309
 310         note->busy = 1;
 311         note->note_number = key;
 312         note->note_velocity = vel;
 313         note->note_track = (unsigned int)(t - midi_trk);
 314         note->note_channel = (unsigned int)(ch - midi_ch);
 315         ach = (unsigned int)(note - midi_notes); /* which FM channel? */
 316         adlib_freq_to_fm_op(&adlib_fm[ach].mod,(double)freq / 65536);
 317         adlib_fm[ach].mod.attack_rate = vel >> 3; /* 0-127 to 0-15 */
 318         adlib_fm[ach].mod.sustain_level = vel >> 3;
 319         adlib_fm[ach].mod.key_on = 1;
 320         adlib_update_groupA0(ach,&adlib_fm[ach]);
 321 }
 322
 323 static inline void on_key_on(struct midi_track *t,struct midi_channel *ch,unsigned char key,unsigned char vel) {
 324         struct midi_note *note = get_fm_note(t,ch,key,/*do_alloc*/1);
 325         uint32_t freq = midi_note_freq(ch,key);
 326         unsigned int ach;
 327
 328         /* HACK: Ignore percussion */
 329         if ((ch->program >= 8 && ch->program <= 15)/*Chromatic percussion*/ ||
 330                 (ch->program >= 112 && ch->program <= 119)/*Percussive*/ ||
 331                 ch == &midi_ch[9]/*MIDI channel 10 (DAMN YOU 1-BASED COUNTING)*/)
 332                 return;
 333
 334         if (note == NULL) {
 335                 /* then we'll have to knock one off to make room */
 336                 drop_fm_note(ch,key);
 337                 note = get_fm_note(t,ch,key,1);
 338                 if (note == NULL) return;
 339         }
 340
 341         note->busy = 1;
 342         note->note_number = key;
 343         note->note_velocity = vel;
 344         note->note_track = (unsigned int)(t - midi_trk);
 345         note->note_channel = (unsigned int)(ch - midi_ch);
 346         ach = (unsigned int)(note - midi_notes); /* which FM channel? */
 347         adlib_freq_to_fm_op(&adlib_fm[ach].mod,(double)freq / 65536);
 348         adlib_fm[ach].mod.attack_rate = vel >> 3; /* 0-127 to 0-15 */
 349         adlib_fm[ach].mod.sustain_level = vel >> 3;
 350         adlib_fm[ach].mod.key_on = 1;
 351         adlib_update_groupA0(ach,&adlib_fm[ach]);
 352 }
 353
 354 static inline void on_key_off(struct midi_track *t,struct midi_channel *ch,unsigned char key,unsigned char vel) {
 355         struct midi_note *note = get_fm_note(t,ch,key,/*do_alloc*/0);
 356         uint32_t freq = midi_note_freq(ch,key);
 357         unsigned int ach;
 358
 359         if (note == NULL) return;
 360
 361         note->busy = 0;
 362         ach = (unsigned int)(note - midi_notes); /* which FM channel? */
 363         adlib_freq_to_fm_op(&adlib_fm[ach].mod,(double)freq / 65536);
 364         adlib_fm[ach].mod.attack_rate = vel >> 3; /* 0-127 to 0-15 */
 365         adlib_fm[ach].mod.sustain_level = vel >> 3;
 366         adlib_fm[ach].mod.key_on = 0;
 367         adlib_update_groupA0(ach,&adlib_fm[ach]);
 368 }
 369
 370 static inline void on_control_change(struct midi_track *t,struct midi_channel *ch,unsigned char num,unsigned char val) {
 371 }
 372
 373 static inline void on_program_change(struct midi_track *t,struct midi_channel *ch,unsigned char inst) {
 374         ch->program = inst;
 375 }
 376
 377 static inline void on_channel_aftertouch(struct midi_track *t,struct midi_channel *ch,unsigned char velocity) {
 378 }
 379
 380 static inline void on_pitch_bend(struct midi_track *t,struct midi_channel *ch,int bend/*-8192 to 8192*/) {
 381 }
 382
 383 unsigned long midi_trk_read_delta(struct midi_track *t) {
 384         unsigned long tc = 0;
 385         unsigned char c = 0,b;
 386
 387         /* NTS: 16-bit large/compact builds MUST compare pointers as unsigned long to compare FAR pointers correctly! */
 388         if (t->read == NULL || (unsigned long)t->read >= (unsigned long)t->fence)
 389                 return tc;
 390
 391         while (c < 4) {
 392                 b = midi_trk_read(t);
 393                 tc = (tc << 7UL) + (unsigned long)(b&0x7F);
 394                 if (!(b&0x80)) break;
 395                 c++;
 396         }
 397
 398         return tc;
 399 }
 400
 401 void midi_tick_track(unsigned int i) {
 402         struct midi_track *t = midi_trk + i;
 403         struct midi_channel *ch;
 404         unsigned char b,c,d;
 405         int cnt=0;
 406
 407         /* NTS: 16-bit large/compact builds MUST compare pointers as unsigned long to compare FAR pointers correctly! */
 408         if (t->read == NULL || (unsigned long)t->read >= (unsigned long)t->fence) {
 409                 t->eof = 1;
 410                 return;
 411         }
 412
 413         t->us_tick_cnt_mtpq += 10000UL * (unsigned long)ticks_per_quarter_note;
 414         while (t->us_tick_cnt_mtpq >= t->us_per_quarter_note) {
 415                 t->us_tick_cnt_mtpq -= t->us_per_quarter_note;
 416                 cnt++;
 417
 418                 while (t->wait == 0) {
 419                         if ((unsigned long)t->read >= (unsigned long)t->fence) {
 420                                 t->eof = 1;
 421                                 break;
 422                         }
 423
 424                         /* read pointer should be pointing at MIDI event bytes, just after the time delay */
 425                         b = midi_trk_read(t);
 426                         if (b&0x80) {
 427                                 if (b < 0xF8) {
 428                                         if (b >= 0xF0)
 429                                                 t->last_status = 0;
 430                                         else
 431                                                 t->last_status = b;
 432                                 }
 433                                 if (b != 0x00 && ((b&0xF8) != 0xF0))
 434                                         c = midi_trk_read(t);
 435                         }
 436                         else {
 437                                 /* blegh. last status */
 438                                 c = b;
 439                                 b = t->last_status;
 440                         }
 441                         switch (b>>4) {
 442                                 case 0x8: { /* note off */
 443                                         d = midi_trk_read(t);
 444                                         ch = midi_ch + (b&0xF); /* c=key d=velocity */
 445                                         on_key_off(t,ch,c,d);
 446                                         } break;
 447                                 case 0x9: { /* note on */
 448                                         d = midi_trk_read(t);
 449                                         ch = midi_ch + (b&0xF); /* c=key d=velocity */
 450                                         if (d != 0) on_key_on(t,ch,c,d); /* "A Note On with a velocity of 0 is actually a note off" Bleh, really? */
 451                                         else on_key_off(t,ch,c,d);
 452                                         } break;
 453                                 case 0xA: { /* polyphonic aftertouch */
 454                                         d = midi_trk_read(t);
 455                                         ch = midi_ch + (b&0xF); /* c=key d=velocity */
 456                                         on_key_aftertouch(t,ch,c,d);
 457                                         } break;
 458                                 case 0xB: { /* control change */
 459                                         d = midi_trk_read(t);
 460                                         ch = midi_ch + (b&0xF); /* c=key d=velocity */
 461                                         on_control_change(t,ch,c,d);
 462                                         } break;
 463                                 case 0xC: { /* program change */
 464                                         on_program_change(t,ch,c); /* c=instrument d=not used */
 465                                         } break;
 466                                 case 0xD: { /* channel aftertouch */
 467                                         on_channel_aftertouch(t,ch,c); /* c=velocity d=not used */
 468                                         } break;
 469                                 case 0xE: { /* pitch bend */
 470                                         d = midi_trk_read(t);
 471                                         on_pitch_bend(t,ch,((c&0x7F)|((d&0x7F)<<7))-8192); /* c=LSB d=MSB */
 472                                         } break;
 473                                 case 0xF: { /* event */
 474                                         if (b == 0xFF) {
 475                                                 if (c == 0x7F) { /* c=type d=len */
 476                                                         unsigned long len = midi_trk_read_delta(t);
 477 //                                                      fprintf(stderr,"Type 0x7F len=%lu %p/%p/%p\n",len,t->raw,t->read,t->fence);
 478                                                         if (len < 512UL) {
 479                                                                 /* unknown */
 480                                                                 midi_trk_skip(t,len);
 481                                                         }
 482                                                         else {
 483                                                                 midi_trk_end(t);
 484                                                         }
 485                                                 }
 486                                                 else if (c < 0x7F) {
 487                                                         d = midi_trk_read(t);
 488
 489                                                         if (c == 0x51 && d >= 3) {
 490                                                                 d -= 3;
 491                                                                 t->us_per_quarter_note = ((unsigned long)midi_trk_read(t)<<16UL)+
 492                                                                         ((unsigned long)midi_trk_read(t)<<8UL)+
 493                                                                         ((unsigned long)midi_trk_read(t)<<0UL);
 494
 495                                                                 if (1/*TODO: If format 0 or format 1*/) {
 496                                                                         /* Ugh. Unless format 2, the tempo applies to all tracks */
 497                                                                         int j;
 498
 499                                                                         for (j=0;j < midi_trk_count;j++) {
 500                                                                                 if (j != i) midi_trk[j].us_per_quarter_note =
 501                                                                                         t->us_per_quarter_note;
 502                                                                         }
 503                                                                 }
 504                                                         }
 505                                                         else {
 506 //                                                              fprintf(stderr,"Type 0x%02x len=%lu %p/%p/%p\n",c,d,t->raw,t->read,t->fence);
 507                                                         }
 508
 509                                                         midi_trk_skip(t,d);
 510                                                 }
 511                                                 else {
 512                                                         fprintf(stderr,"t=%u Unknown MIDI f message 0x%02x 0x%02x %p/%p/%p\n",i,b,c,t->raw,t->read,t->fence);
 513                                                 }
 514                                         }
 515                                         else {
 516                                                 unsigned long len = midi_trk_read_delta(t);
 517 //                                              fprintf(stderr,"Sysex len=%lu %p/%p/%p\n",len,t->raw,t->read,t->fence);
 518                                                 midi_trk_skip(t,len);
 519                                         }
 520                                         } break;
 521                                 default:
 522                                         if (b != 0x00) {
 523                                                 fprintf(stderr,"t=%u Unknown MIDI message 0x%02x at %p/%p/%p\n",i,b,t->raw,t->read,t->fence);
 524                                                 midi_trk_end(t);
 525                                         }
 526                                         break;
 527                         };
 528
 529                         /* and then read the next event */
 530                         t->wait = midi_trk_read_delta(t);
 531                 }
 532                 if (t->wait != 0) {
 533                         t->wait--;
 534                 }
 535         }
 536 }
 537
 538 void adlib_shut_up();
 539 void midi_reset_tracks();
 540 void midi_reset_channels();
 541
 542 void midi_tick() {
 543         if (midi_playing) {
 544                 unsigned int i;
 545                 int eof=0;
 546
 547                 for (i=0;i < midi_trk_count;i++) {
 548                         midi_tick_track(i);
 549                         eof += midi_trk[i].eof?1:0;
 550                 }
 551
 552                 if (eof >= midi_trk_count) {
 553                         adlib_shut_up();
 554                         midi_reset_tracks();
 555                         midi_reset_channels();
 556                 }
 557         }
 558 }
 559
 560 /* WARNING: subroutine call in interrupt handler. make sure you compile with -zu flag for large/compact memory models */
 561 void interrupt irq0() {
 562 //      midi_tick();
 563         irq0_ticks++;
 564         if ((irq0_cnt += irq0_add) >= irq0_max) {
 565                 irq0_cnt -= irq0_max;
 566                 old_irq0();
 567         }
 568         else {
 569                 p8259_OCW2(0,P8259_OCW2_NON_SPECIFIC_EOI);
 570         }
 571 }
 572
 573 void adlib_shut_up() {
 574         int i;
 575
 576         memset(adlib_fm,0,sizeof(adlib_fm));
 577         memset(&adlib_reg_bd,0,sizeof(adlib_reg_bd));
 578         for (i=0;i < adlib_fm_voices;i++) {
 579                 struct adlib_fm_operator *f;
 580                 f = &adlib_fm[i].mod;
 581                 f->ch_a = f->ch_b = f->ch_c = f->ch_d = 1;
 582                 f = &adlib_fm[i].car;
 583                 f->ch_a = f->ch_b = f->ch_c = f->ch_d = 1;
 584         }
 585
 586         for (i=0;i < adlib_fm_voices;i++) {
 587                 struct adlib_fm_operator *f;
 588
 589                 midi_notes[i].busy = 0;
 590                 midi_notes[i].note_channel = 0;
 591
 592                 f = &adlib_fm[i].mod;
 593                 f->mod_multiple = 1;
 594                 f->total_level = 63 - 16;
 595                 f->attack_rate = 15;
 596                 f->decay_rate = 4;
 597                 f->sustain_level = 0;
 598                 f->release_rate = 8;
 599                 f->f_number = 400;
 600                 f->sustain = 1;
 601                 f->octave = 4;
 602                 f->key_on = 0;
 603
 604                 f = &adlib_fm[i].car;
 605                 f->mod_multiple = 1;
 606                 f->total_level = 63 - 16;
 607                 f->attack_rate = 15;
 608                 f->decay_rate = 4;
 609                 f->sustain_level = 0;
 610                 f->release_rate = 8;
 611                 f->f_number = 0;
 612                 f->sustain = 1;
 613                 f->octave = 0;
 614                 f->key_on = 0;
 615         }
 616
 617         adlib_apply_all();
 618 }
 619
 620 void midi_reset_track(unsigned int i) {
 621         struct midi_track *t;
 622
 623         if (i >= MIDI_MAX_TRACKS) return;
 624         t = &midi_trk[i];
 625         t->eof = 0;
 626         t->last_status = 0;
 627         t->us_tick_cnt_mtpq = 0;
 628         t->us_per_quarter_note = (60000000UL / 120UL); /* 120BPM */
 629         t->read = midi_trk[i].raw;
 630         t->wait = midi_trk_read_delta(t); /* and then the read pointer will point at the MIDI event when wait counts down */
 631 }
 632
 633 void midi_reset_tracks() {
 634         int i;
 635
 636         for (i=0;i < midi_trk_count;i++)
 637                 midi_reset_track(i);
 638 }
 639
 640 void midi_reset_channels() {
 641         int i;
 642
 643         for (i=0;i < MIDI_MAX_CHANNELS;i++) {
 644                 midi_ch[i].program = 0;
 645         }
 646 }
 647
 648 int load_midi_file(const char *path) {
 649         unsigned char tmp[256];
 650         unsigned int tracks=0;
 651         unsigned int tracki=0;
 652         int fd;
 653
 654         fd = open(path,O_RDONLY|O_BINARY);
 655         if (fd < 0) {
 656                 printf("Failed to load file %s\n",path);
 657                 return 0;
 658         }
 659
 660         ticks_per_quarter_note = 0;
 661         while (read(fd,tmp,8) == 8) {
 662                 uint32_t sz;
 663
 664                 sz =    ((uint32_t)tmp[4] << (uint32_t)24) |
 665                         ((uint32_t)tmp[5] << (uint32_t)16) |
 666                         ((uint32_t)tmp[6] << (uint32_t)8) |
 667                         ((uint32_t)tmp[7] << (uint32_t)0);
 668                 if (!memcmp(tmp,"MThd",4)) {
 669                         unsigned short t,tdiv;
 670
 671                         if (sz < 6 || sz > 255) {
 672                                 fprintf(stderr,"Invalid MThd size %lu\n",(unsigned long)sz);
 673                                 goto err;
 674                         }
 675                         if (read(fd,tmp,(int)sz) != (int)sz) {
 676                                 fprintf(stderr,"MThd read error\n");
 677                                 goto err;
 678                         }
 679
 680                         /* byte 0-1 = format type (0,1 or 2) */
 681                         /* byte 2-3 = number of tracks */
 682                         /* byte 4-5 = time divison */
 683                         t = tmp[1] | (tmp[0] << 8);
 684                         if (t > 1) {
 685                                 fprintf(stderr,"MThd type %u not supported\n",t);
 686                                 goto err; /* we only take type 0 or 1, don't support 2 */
 687                         }
 688                         tracks = tmp[3] | (tmp[2] << 8);
 689                         if (tracks > MIDI_MAX_TRACKS) {
 690                                 fprintf(stderr,"MThd too many (%u) tracks\n",tracks);
 691                                 goto err;
 692                         }
 693                         tdiv = tmp[5] | (tmp[4] << 8);
 694                         if (tdiv & 0x8000) {
 695                                 fprintf(stderr,"MThd SMPTE time division not supported\n");
 696                                 goto err; /* we do not support the SMPTE form */
 697                         }
 698                         if (tdiv == 0) {
 699                                 fprintf(stderr,"MThd time division == 0\n");
 700                                 goto err;
 701                         }
 702                         ticks_per_quarter_note = tdiv;
 703                 }
 704                 else if (!memcmp(tmp,"MTrk",4)) {
 705                         if (sz == 0UL) continue;
 706 #if TARGET_MSDOS == 16 && (defined(__LARGE__) || defined(__COMPACT__))
 707                         if (sz > (640UL << 10UL)) goto err; /* 640KB */
 708 #elif TARGET_MSDOS == 32
 709                         if (sz > (1UL << 20UL)) goto err; /* 1MB */
 710 #else
 711                         if (sz > (60UL << 10UL)) goto err; /* 60KB */
 712 #endif
 713                         if (tracki >= MIDI_MAX_TRACKS) goto err;
 714 #if TARGET_MSDOS == 16 && (defined(__LARGE__) || defined(__COMPACT__))
 715                         {
 716                                 unsigned segv;
 717
 718                                 /* NTS: _fmalloc() is still limited to 64KB sizes */
 719                                 if (_dos_allocmem((unsigned)((sz+15UL)>>4UL),&segv) != 0) goto err;
 720                                 midi_trk[tracki].raw = MK_FP(segv,0);
 721                         }
 722 #else
 723                         midi_trk[tracki].raw = malloc(sz);
 724 #endif
 725                         if (midi_trk[tracki].raw == NULL) goto err;
 726                         midi_trk[tracki].read = midi_trk[tracki].raw;
 727 #if TARGET_MSDOS == 16 && (defined(__LARGE__) || defined(__COMPACT__))
 728                         {
 729                                 unsigned char far *p = midi_trk[tracki].raw;
 730                                 unsigned long rem = (unsigned long)sz;
 731                                 unsigned long cando;
 732                                 unsigned read;
 733
 734                                 while (rem != 0UL) {
 735                                         read = 0;
 736
 737                                         cando = 0x10000UL - (unsigned long)FP_OFF(p);
 738                                         if (cando > rem) cando = rem;
 739                                         if (cando > 0xFFFFUL) cando = 0xFFFFUL; /* we're limited to 64KB-1 of reading */
 740
 741                                         if (_dos_read(fd,p,(unsigned)cando,&read) != 0) goto err;
 742                                         if (read != (unsigned)cando) goto err;
 743
 744                                         rem -= cando;
 745                                         if ((((unsigned long)FP_OFF(p))+cando) == 0x10000UL)
 746                                                 p = MK_FP(FP_SEG(p)+0x1000,0);
 747                                         else
 748                                                 p += (unsigned)cando;
 749                                 }
 750
 751                                 cando = farptr2phys(p);
 752                                 midi_trk[tracki].fence = MK_FP(cando>>4,cando&0xF);
 753                         }
 754 #else
 755                         midi_trk[tracki].fence = midi_trk[tracki].raw + (unsigned)sz;
 756                         if (read(fd,midi_trk[tracki].raw,(unsigned)sz) != (int)sz) goto err;
 757 #endif
 758                         tracki++;
 759                 }
 760                 else {
 761                         fprintf(stderr,"Unknown MIDI chunk %c%c%c%c\n",tmp[0],tmp[1],tmp[2],tmp[3]);
 762                         goto err;
 763                 }
 764         }
 765         if (tracki == 0 || ticks_per_quarter_note == 0) goto err;
 766         midi_trk_count = tracki;
 767
 768         fprintf(stderr,"Ticks per quarter note: %u\n",ticks_per_quarter_note);
 769
 770         close(fd);
 771         return 1;
 772 err:
 773         close(fd);
 774         return 0;
 775 }
 776
 777 int main(int argc,char **argv) {
 778         unsigned long ptick;
 779         int i,c;
 780
 781         printf("ADLIB FM test program\n");
 782         if (argc < 2) {
 783                 printf("You must specify a MIDI file to play\n");
 784                 return 1;
 785         }
 786
 787         if (!probe_vga()) {
 788                 printf("Cannot init VGA\n");
 789                 return 1;
 790         }
 791         if (!init_adlib()) {
 792                 printf("Cannot init library\n");
 793                 return 1;
 794         }
 795         if (!probe_8254()) { /* we need the timer to keep time with the music */
 796                 printf("8254 timer not found\n");
 797                 return 1;
 798         }
 799
 800         for (i=0;i < MIDI_MAX_TRACKS;i++) {
 801                 midi_trk[i].raw = NULL;
 802                 midi_trk[i].read = NULL;
 803                 midi_trk[i].fence = NULL;
 804         }
 805
 806         if (load_midi_file(argv[1]) == 0) {
 807                 printf("Failed to load MIDI\n");
 808                 return 1;
 809         }
 810
 811         write_8254_system_timer(T8254_REF_CLOCK_HZ / 100); /* tick faster at 100Hz please */
 812         irq0_cnt = 0;
 813         irq0_add = 182;
 814         irq0_max = 1000; /* about 18.2Hz */
 815         old_irq0 = _dos_getvect(8);/*IRQ0*/
 816         _dos_setvect(8,irq0);
 817
 818         adlib_shut_up();
 819         midi_reset_channels();
 820         midi_reset_tracks();
 821         _cli();
 822         irq0_ticks = ptick = 0;
 823         _sti();
 824         midi_playing = 1;
 825
 826         while (1) {
 827                 unsigned long adv;
 828
 829                 _cli();
 830                 adv = irq0_ticks - ptick;
 831                 if (adv >= 100UL) adv = 100UL;
 832                 ptick = irq0_ticks;
 833                 _sti();
 834
 835                 while (adv != 0) {
 836                         midi_tick();
 837                         adv--;
 838                 }
 839
 840                 if (kbhit()) {
 841                         c = getch();
 842                         if (c == 0) c = getch() << 8;
 843
 844                         if (c == 27) {
 845                                 break;
 846                         }
 847                 }
 848         }
 849
 850         midi_playing = 0;
 851         adlib_shut_up();
 852         shutdown_adlib();
 853         _dos_setvect(8,old_irq0);
 854         write_8254_system_timer(0); /* back to normal 18.2Hz */
 855
 856         for (i=0;i < MIDI_MAX_TRACKS;i++) {
 857                 if (midi_trk[i].raw) {
 858 #if TARGET_MSDOS == 16 && (defined(__LARGE__) || defined(__COMPACT__))
 859                         _dos_freemem(FP_SEG(midi_trk[i].raw)); /* NTS: Because we allocated with _dos_allocmem */
 860 #else
 861                         free(midi_trk[i].raw);
 862 #endif
 863                         midi_trk[i].raw = NULL;
 864                 }
 865                 midi_trk[i].fence = NULL;
 866                 midi_trk[i].read = NULL;
 867         }
 868
 869         return 0;
 870 }