/
mixer.c
935 lines (834 loc) · 22.6 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
/*
MIXERLIB: An audio mixer library based on the SDL library
Copyright (C) 1997-1999 Sam Lantinga
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Sam Lantinga
5635-34 Springhouse Dr.
Pleasanton, CA 94588 (USA)
slouken@devolution.com
*/
25
26
/* $Id$ */
27
28
29
30
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
31
32
#include "SDL_mutex.h"
#include "SDL_endian.h"
33
#include "SDL_timer.h"
34
35
#include "SDL_mixer.h"
36
37
38
39
40
41
#include "load_aiff.h"
#include "load_voc.h"
/* Magic numbers for various audio file formats */
#define WAVE 0x45564157 /* "WAVE" */
#define FORM 0x4d524f46 /* "FORM" */
42
43
44
45
46
47
48
49
50
51
52
53
static int audio_opened = 0;
static SDL_AudioSpec mixer;
static SDL_mutex *mixer_lock;
static struct _Mix_Channel {
Mix_Chunk *chunk;
int playing;
int paused;
Uint8 *samples;
int volume;
int looping;
54
int tag;
55
Uint32 expire;
56
Uint32 start_time;
57
58
Mix_Fading fading;
int fade_volume;
59
Uint32 fade_length;
60
Uint32 ticks_fade;
61
} *mix_channel = NULL;
62
static int num_channels;
63
static int reserved_channels = 0;
64
65
66
67
/* Support for hooking into the mixer callback system */
static void (*mix_postmix)(void *udata, Uint8 *stream, int len) = NULL;
68
static void *mix_postmix_data = NULL;
69
70
71
72
/* rcg07062001 callback to alert when channels are done playing. */
static void (*channel_done_callback)(int channel) = NULL;
73
74
75
76
/* Music function declarations */
extern int open_music(SDL_AudioSpec *mixer);
extern void close_music(void);
77
/* Support for user defined music functions, plus the default one */
78
extern int volatile music_active;
79
80
extern void music_mixer(void *udata, Uint8 *stream, int len);
static void (*mix_music)(void *udata, Uint8 *stream, int len) = music_mixer;
81
static void *music_data = NULL;
82
83
84
85
86
/* Mixing function */
static void mix_channels(void *udata, Uint8 *stream, int len)
{
int i, mixable, volume;
87
Uint32 sdl_ticks;
88
89
/* Mix the music (must be done before the channels are added) */
90
if ( music_active || (mix_music != music_mixer) ) {
91
92
93
mix_music(music_data, stream, len);
}
94
95
/* Grab the channels we need to mix */
SDL_mutexP(mixer_lock);
96
97
sdl_ticks = SDL_GetTicks();
for ( i=0; i<num_channels; ++i ) {
98
99
if( ! mix_channel[i].paused ) {
if ( mix_channel[i].expire > 0 && mix_channel[i].expire < sdl_ticks ) {
100
/* Expiration delay for that channel is reached */
101
102
103
104
105
106
107
108
109
110
mix_channel[i].playing = 0;
mix_channel[i].fading = MIX_NO_FADING;
mix_channel[i].expire = 0;
} else if ( mix_channel[i].fading != MIX_NO_FADING ) {
Uint32 ticks = sdl_ticks - mix_channel[i].ticks_fade;
if( ticks > mix_channel[i].fade_length ) {
if( mix_channel[i].fading == MIX_FADING_OUT ) {
mix_channel[i].playing = 0;
mix_channel[i].expire = 0;
Mix_Volume(i, mix_channel[i].fading); /* Restore the volume */
111
}
112
mix_channel[i].fading = MIX_NO_FADING;
113
} else {
114
115
116
if( mix_channel[i].fading == MIX_FADING_OUT ) {
Mix_Volume(i, (mix_channel[i].fade_volume * (mix_channel[i].fade_length-ticks))
/ mix_channel[i].fade_length );
117
} else {
118
Mix_Volume(i, (mix_channel[i].fade_volume * ticks) / mix_channel[i].fade_length );
119
}
120
121
}
}
122
123
124
if ( mix_channel[i].playing > 0 ) {
volume = (mix_channel[i].volume*mix_channel[i].chunk->volume) / MIX_MAX_VOLUME;
mixable = mix_channel[i].playing;
125
126
127
if ( mixable > len ) {
mixable = len;
}
128
129
130
SDL_MixAudio(stream,mix_channel[i].samples,mixable,volume);
mix_channel[i].samples += mixable;
mix_channel[i].playing -= mixable;
131
132
/* If looping the sample and we are at its end, make sure
we will still return a full buffer */
133
while ( mix_channel[i].looping && mixable < len ) {
134
int remaining = len - mixable;
135
int alen = mix_channel[i].chunk->alen;
136
137
138
if (remaining > alen) {
remaining = alen;
}
139
140
141
142
SDL_MixAudio(stream+mixable, mix_channel[i].chunk->abuf, remaining, volume);
--mix_channel[i].looping;
mix_channel[i].samples = mix_channel[i].chunk->abuf + remaining;
mix_channel[i].playing = mix_channel[i].chunk->alen - remaining;
143
144
mixable += remaining;
}
145
146
147
148
if ( ! mix_channel[i].playing && mix_channel[i].looping ) {
if ( --mix_channel[i].looping ) {
mix_channel[i].samples = mix_channel[i].chunk->abuf;
mix_channel[i].playing = mix_channel[i].chunk->alen;
149
}
150
}
151
152
153
154
155
/* rcg06072001 Alert app if channel is done playing. */
if ( (!mix_channel[i].playing) && (channel_done_callback) ) {
channel_done_callback(i);
}
156
157
158
}
}
}
159
160
161
if ( mix_postmix ) {
mix_postmix(mix_postmix_data, stream, len);
}
162
163
164
165
166
167
168
169
170
171
172
SDL_mutexV(mixer_lock);
}
static void PrintFormat(char *title, SDL_AudioSpec *fmt)
{
printf("%s: %d bit %s audio (%s) at %u Hz\n", title, (fmt->format&0xFF),
(fmt->format&0x8000) ? "signed" : "unsigned",
(fmt->channels > 1) ? "stereo" : "mono", fmt->freq);
}
/* Open the mixer with a certain desired audio format */
173
int Mix_OpenAudio(int frequency, Uint16 format, int nchannels, int chunksize)
174
175
176
177
178
179
180
181
182
183
184
185
186
{
int i;
SDL_AudioSpec desired;
/* If the mixer is already opened, increment open count */
if ( audio_opened ) {
++audio_opened;
return(0);
}
/* Set the desired format and frequency */
desired.freq = frequency;
desired.format = format;
187
desired.channels = nchannels;
188
189
190
191
192
193
194
195
196
197
198
199
200
201
desired.samples = chunksize;
desired.callback = mix_channels;
desired.userdata = NULL;
/* Accept nearly any audio format */
if ( SDL_OpenAudio(&desired, &mixer) < 0 ) {
return(-1);
}
#if 0
PrintFormat("Audio device", &mixer);
#endif
/* Create the channel lock mutex */
mixer_lock = SDL_CreateMutex();
202
#ifndef macintosh /* Hmm.. what implications does this have? */
203
204
205
206
207
if ( mixer_lock == NULL ) {
SDL_CloseAudio();
SDL_SetError("Unable to create mixer lock");
return(-1);
}
208
#endif
209
210
211
212
213
214
215
/* Initialize the music players */
if ( open_music(&mixer) < 0 ) {
SDL_CloseAudio();
SDL_DestroyMutex(mixer_lock);
return(-1);
}
216
217
num_channels = MIX_CHANNELS;
218
mix_channel = (struct _Mix_Channel *) malloc(num_channels * sizeof(struct _Mix_Channel));
219
220
/* Clear out the audio channels */
221
for ( i=0; i<num_channels; ++i ) {
222
223
224
225
226
227
mix_channel[i].chunk = NULL;
mix_channel[i].playing = 0;
mix_channel[i].looping = 0;
mix_channel[i].volume = SDL_MIX_MAXVOLUME;
mix_channel[i].tag = -1;
mix_channel[i].expire = 0;
228
229
230
231
232
233
234
}
Mix_VolumeMusic(SDL_MIX_MAXVOLUME);
audio_opened = 1;
SDL_PauseAudio(0);
return(0);
}
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
/* Dynamically change the number of channels managed by the mixer.
If decreasing the number of channels, the upper channels are
stopped.
*/
int Mix_AllocateChannels(int numchans)
{
if ( numchans<0 || numchans==num_channels )
return(num_channels);
if ( numchans < num_channels ) {
/* Stop the affected channels */
int i;
for(i=numchans; i < num_channels; i++) {
Mix_HaltChannel(i);
}
}
SDL_mutexP(mixer_lock);
252
mix_channel = (struct _Mix_Channel *) realloc(mix_channel, numchans * sizeof(struct _Mix_Channel));
253
254
255
256
if ( numchans > num_channels ) {
/* Initialize the new channels */
int i;
for(i=num_channels; i < numchans; i++) {
257
258
259
260
261
262
mix_channel[i].chunk = NULL;
mix_channel[i].playing = 0;
mix_channel[i].looping = 0;
mix_channel[i].volume = SDL_MIX_MAXVOLUME;
mix_channel[i].tag = -1;
mix_channel[i].expire = 0;
263
264
265
266
267
268
269
}
}
num_channels = numchans;
SDL_mutexV(mixer_lock);
return(num_channels);
}
270
271
272
273
274
275
276
277
278
279
/* Return the actual mixer parameters */
int Mix_QuerySpec(int *frequency, Uint16 *format, int *channels)
{
if ( audio_opened ) {
if ( frequency ) {
*frequency = mixer.freq;
}
if ( format ) {
*format = mixer.format;
}
280
if ( channels ) {
281
282
283
284
285
286
*channels = mixer.channels;
}
}
return(audio_opened);
}
287
288
289
290
291
292
/*
* !!! FIXME: Ideally, we want a Mix_LoadSample_RW(), which will handle the
* generic setup, then call the correct file format loader.
*/
293
294
295
/* Load a wave file */
Mix_Chunk *Mix_LoadWAV_RW(SDL_RWops *src, int freesrc)
{
296
Uint32 magic;
297
Mix_Chunk *chunk;
298
SDL_AudioSpec wavespec, *loaded;
299
SDL_AudioCVT wavecvt;
300
int samplesize;
301
302
303
/* rcg06012001 Make sure src is valid */
if ( ! src ) {
304
SDL_SetError("Mix_LoadWAV_RW with NULL src");
305
306
307
return(NULL);
}
308
309
310
/* Make sure audio has been opened */
if ( ! audio_opened ) {
SDL_SetError("Audio device hasn't been opened");
311
if ( freesrc && src ) {
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
SDL_RWclose(src);
}
return(NULL);
}
/* Allocate the chunk memory */
chunk = (Mix_Chunk *)malloc(sizeof(Mix_Chunk));
if ( chunk == NULL ) {
SDL_SetError("Out of memory");
if ( freesrc ) {
SDL_RWclose(src);
}
return(NULL);
}
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
/* Find out what kind of audio file this is */
magic = SDL_ReadLE32(src);
/* Seek backwards for compatibility with older loaders */
SDL_RWseek(src, -sizeof(Uint32), SEEK_CUR);
switch (magic) {
case WAVE:
loaded = SDL_LoadWAV_RW(src, freesrc, &wavespec,
(Uint8 **)&chunk->abuf, &chunk->alen);
break;
case FORM:
loaded = Mix_LoadAIFF_RW(src, freesrc, &wavespec,
(Uint8 **)&chunk->abuf, &chunk->alen);
break;
default:
loaded = Mix_LoadVOC_RW(src, freesrc, &wavespec,
(Uint8 **)&chunk->abuf, &chunk->alen);
break;
}
if ( !loaded ) {
347
348
349
free(chunk);
return(NULL);
}
350
351
352
353
354
355
356
357
358
359
360
361
362
363
#if 0
PrintFormat("Audio device", &mixer);
PrintFormat("-- Wave file", &wavespec);
#endif
/* Build the audio converter and create conversion buffers */
if ( SDL_BuildAudioCVT(&wavecvt,
wavespec.format, wavespec.channels, wavespec.freq,
mixer.format, mixer.channels, mixer.freq) < 0 ) {
SDL_FreeWAV(chunk->abuf);
free(chunk);
return(NULL);
}
364
365
samplesize = ((wavespec.format & 0xFF)/8)*wavespec.channels;
wavecvt.len = chunk->alen & ~(samplesize-1);
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
wavecvt.buf = (Uint8 *)malloc(wavecvt.len*wavecvt.len_mult);
if ( wavecvt.buf == NULL ) {
SDL_SetError("Out of memory");
SDL_FreeWAV(chunk->abuf);
free(chunk);
return(NULL);
}
memcpy(wavecvt.buf, chunk->abuf, chunk->alen);
SDL_FreeWAV(chunk->abuf);
/* Run the audio converter */
if ( SDL_ConvertAudio(&wavecvt) < 0 ) {
free(wavecvt.buf);
free(chunk);
return(NULL);
}
382
chunk->allocated = 1;
383
384
385
386
387
388
chunk->abuf = wavecvt.buf;
chunk->alen = wavecvt.len_cvt;
chunk->volume = MIX_MAX_VOLUME;
return(chunk);
}
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
/* Load a wave file of the mixer format from a memory buffer */
Mix_Chunk *Mix_QuickLoad_WAV(Uint8 *mem)
{
Mix_Chunk *chunk;
Uint8 magic[4];
/* Make sure audio has been opened */
if ( ! audio_opened ) {
SDL_SetError("Audio device hasn't been opened");
return(NULL);
}
/* Allocate the chunk memory */
chunk = (Mix_Chunk *)malloc(sizeof(Mix_Chunk));
if ( chunk == NULL ) {
SDL_SetError("Out of memory");
return(NULL);
}
/* Essentially just skip to the audio data (no error checking - fast) */
chunk->allocated = 0;
mem += 12; /* WAV header */
do {
memcpy(magic, mem, 4);
mem += 4;
chunk->alen = ((mem[3]<<24)|(mem[2]<<16)|(mem[1]<<8)|(mem[0]));
mem += 4;
chunk->abuf = mem;
mem += chunk->alen;
} while ( memcmp(magic, "data", 4) != 0 );
chunk->volume = MIX_MAX_VOLUME;
return(chunk);
}
424
425
426
427
428
429
430
431
/* Free an audio chunk previously loaded */
void Mix_FreeChunk(Mix_Chunk *chunk)
{
int i;
/* Caution -- if the chunk is playing, the mixer will crash */
if ( chunk ) {
/* Guarantee that this chunk isn't playing */
432
433
434
435
436
437
if ( mix_channel ) {
SDL_mutexP(mixer_lock);
for ( i=0; i<num_channels; ++i ) {
if ( chunk == mix_channel[i].chunk ) {
mix_channel[i].playing = 0;
}
438
}
439
SDL_mutexV(mixer_lock);
440
441
442
}
/* Actually free the chunk */
443
444
445
if ( chunk->allocated ) {
free(chunk->abuf);
}
446
447
448
449
free(chunk);
}
}
450
451
452
453
454
455
456
457
458
459
460
461
462
/* Set a function that is called after all mixing is performed.
This can be used to provide real-time visual display of the audio stream
or add a custom mixer filter for the stream data.
*/
void Mix_SetPostMix(void (*mix_func)
(void *udata, Uint8 *stream, int len), void *arg)
{
SDL_LockAudio();
mix_postmix_data = arg;
mix_postmix = mix_func;
SDL_UnlockAudio();
}
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
/* Add your own music player or mixer function.
If 'mix_func' is NULL, the default music player is re-enabled.
*/
void Mix_HookMusic(void (*mix_func)(void *udata, Uint8 *stream, int len),
void *arg)
{
SDL_LockAudio();
if ( mix_func != NULL ) {
music_data = arg;
mix_music = mix_func;
} else {
music_data = NULL;
mix_music = music_mixer;
}
SDL_UnlockAudio();
}
void *Mix_GetMusicHookData(void)
{
return(music_data);
}
485
486
487
488
489
490
491
492
void Mix_ChannelFinished(void (*channel_finished)(int channel))
{
SDL_LockAudio();
channel_done_callback = channel_finished;
SDL_UnlockAudio();
}
493
494
495
496
497
498
/* Reserve the first channels (0 -> n-1) for the application, i.e. don't allocate
them dynamically to the next sample if requested with a -1 value below.
Returns the number of reserved channels.
*/
int Mix_ReserveChannels(int num)
{
499
500
if (num > num_channels)
num = num_channels;
501
502
503
504
505
506
reserved_channels = num;
return num;
}
/* Play an audio chunk on a specific channel.
If the specified channel is -1, play on the first free channel.
507
508
'ticks' is the number of milliseconds at most to play the sample, or -1
if there is no limit.
509
510
Returns which channel was used to play the sound.
*/
511
int Mix_PlayChannelTimed(int which, Mix_Chunk *chunk, int loops, int ticks)
512
513
514
515
516
517
518
519
520
521
522
523
524
{
int i;
/* Don't play null pointers :-) */
if ( chunk == NULL ) {
return(-1);
}
/* Lock the mixer while modifying the playing channels */
SDL_mutexP(mixer_lock);
{
/* If which is -1, play on the first free channel */
if ( which == -1 ) {
525
for ( i=reserved_channels; i<num_channels; ++i ) {
526
if ( mix_channel[i].playing <= 0 )
527
528
break;
}
529
if ( i == num_channels ) {
530
531
532
533
534
535
536
537
which = -1;
} else {
which = i;
}
}
/* Queue up the audio data for this channel */
if ( which >= 0 ) {
538
Uint32 sdl_ticks = SDL_GetTicks();
539
540
541
542
543
544
545
546
mix_channel[which].samples = chunk->abuf;
mix_channel[which].playing = chunk->alen;
mix_channel[which].looping = loops;
mix_channel[which].chunk = chunk;
mix_channel[which].paused = 0;
mix_channel[which].fading = MIX_NO_FADING;
mix_channel[which].start_time = sdl_ticks;
mix_channel[which].expire = (ticks>0) ? (sdl_ticks + ticks) : 0;
547
548
549
550
551
552
553
554
}
}
SDL_mutexV(mixer_lock);
/* Return the channel on which the sound is being played */
return(which);
}
555
556
557
558
559
560
561
562
563
564
565
566
/* Change the expiration delay for a channel */
int Mix_ExpireChannel(int which, int ticks)
{
int status = 0;
if ( which == -1 ) {
int i;
for ( i=0; i < num_channels; ++ i ) {
status += Mix_ExpireChannel(i, ticks);
}
} else if ( which < num_channels ) {
SDL_mutexP(mixer_lock);
567
mix_channel[which].expire = (ticks>0) ? (SDL_GetTicks() + ticks) : 0;
568
569
570
571
572
573
SDL_mutexV(mixer_lock);
++ status;
}
return(status);
}
574
/* Fade in a sound on a channel, over ms milliseconds */
575
int Mix_FadeInChannelTimed(int which, Mix_Chunk *chunk, int loops, int ms, int ticks)
576
577
578
579
580
581
582
583
584
585
586
587
588
{
int i;
/* Don't play null pointers :-) */
if ( chunk == NULL ) {
return(-1);
}
/* Lock the mixer while modifying the playing channels */
SDL_mutexP(mixer_lock);
{
/* If which is -1, play on the first free channel */
if ( which == -1 ) {
589
for ( i=reserved_channels; i<num_channels; ++i ) {
590
if ( mix_channel[i].playing <= 0 )
591
592
break;
}
593
if ( i == num_channels ) {
594
595
596
597
598
599
600
601
which = -1;
} else {
which = i;
}
}
/* Queue up the audio data for this channel */
if ( which >= 0 ) {
602
Uint32 sdl_ticks = SDL_GetTicks();
603
604
605
606
607
608
609
610
611
612
613
mix_channel[which].samples = chunk->abuf;
mix_channel[which].playing = chunk->alen;
mix_channel[which].looping = loops;
mix_channel[which].chunk = chunk;
mix_channel[which].paused = 0;
mix_channel[which].fading = MIX_FADING_IN;
mix_channel[which].fade_volume = mix_channel[which].volume;
mix_channel[which].volume = 0;
mix_channel[which].fade_length = (Uint32)ms;
mix_channel[which].start_time = mix_channel[which].ticks_fade = sdl_ticks;
mix_channel[which].expire = (ticks > 0) ? (sdl_ticks+ticks) : 0;
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
}
}
SDL_mutexV(mixer_lock);
/* Return the channel on which the sound is being played */
return(which);
}
/* Set volume of a particular channel */
int Mix_Volume(int which, int volume)
{
int i;
int prev_volume;
if ( which == -1 ) {
prev_volume = 0;
630
for ( i=0; i<num_channels; ++i ) {
631
632
prev_volume += Mix_Volume(i, volume);
}
633
prev_volume /= num_channels;
634
} else {
635
prev_volume = mix_channel[which].volume;
636
637
if ( volume < 0 ) {
volume = 0;
638
}
639
640
641
if ( volume > SDL_MIX_MAXVOLUME ) {
volume = SDL_MIX_MAXVOLUME;
}
642
mix_channel[which].volume = volume;
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
}
return(prev_volume);
}
/* Set volume of a particular chunk */
int Mix_VolumeChunk(Mix_Chunk *chunk, int volume)
{
int prev_volume;
prev_volume = chunk->volume;
if ( volume >= 0 ) {
if ( volume > MIX_MAX_VOLUME ) {
volume = MIX_MAX_VOLUME;
}
chunk->volume = volume;
}
return(prev_volume);
}
/* Halt playing of a particular channel */
int Mix_HaltChannel(int which)
{
int i;
if ( which == -1 ) {
667
for ( i=0; i<num_channels; ++i ) {
668
669
670
671
Mix_HaltChannel(i);
}
} else {
SDL_mutexP(mixer_lock);
672
673
674
675
676
mix_channel[which].playing = 0;
mix_channel[which].expire = 0;
if(mix_channel[which].fading != MIX_NO_FADING) /* Restore volume */
mix_channel[which].volume = mix_channel[which].fade_volume;
mix_channel[which].fading = MIX_NO_FADING;
677
678
679
680
681
SDL_mutexV(mixer_lock);
}
return(0);
}
682
683
684
685
686
687
/* Halt playing of a particular group of channels */
int Mix_HaltGroup(int tag)
{
int i;
for ( i=0; i<num_channels; ++i ) {
688
if( mix_channel[i].tag == tag ) {
689
690
691
692
693
694
Mix_HaltChannel(i);
}
}
return(0);
}
695
696
697
698
699
700
/* Fade out a channel and then stop it automatically */
int Mix_FadeOutChannel(int which, int ms)
{
int status;
status = 0;
701
702
703
if ( audio_opened ) {
if ( which == -1 ) {
int i;
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
for ( i=0; i<num_channels; ++i ) {
status += Mix_FadeOutChannel(i, ms);
}
} else {
SDL_mutexP(mixer_lock);
if ( mix_channel[which].playing &&
(mix_channel[which].volume > 0) &&
(mix_channel[which].fading != MIX_FADING_OUT) ) {
mix_channel[which].fading = MIX_FADING_OUT;
mix_channel[which].fade_volume = mix_channel[which].volume;
mix_channel[which].fade_length = ms;
mix_channel[which].ticks_fade = SDL_GetTicks();
++status;
}
SDL_mutexV(mixer_lock);
721
722
723
724
725
}
}
return(status);
}
726
727
728
729
730
731
/* Halt playing of a particular group of channels */
int Mix_FadeOutGroup(int tag, int ms)
{
int i;
int status = 0;
for ( i=0; i<num_channels; ++i ) {
732
if( mix_channel[i].tag == tag ) {
733
734
735
736
737
738
status += Mix_FadeOutChannel(i,ms);
}
}
return(status);
}
739
740
Mix_Fading Mix_FadingChannel(int which)
{
741
return mix_channel[which].fading;
742
743
}
744
/* Check the status of a specific channel.
745
If the specified mix_channel is -1, check all mix_channels.
746
747
748
749
750
751
752
753
754
*/
int Mix_Playing(int which)
{
int status;
status = 0;
if ( which == -1 ) {
int i;
755
for ( i=0; i<num_channels; ++i ) {
756
if ( mix_channel[i].playing > 0 ) {
757
758
759
760
++status;
}
}
} else {
761
if ( mix_channel[which].playing > 0 ) {
762
763
764
765
766
767
++status;
}
}
return(status);
}
768
769
770
771
772
773
774
775
776
777
778
779
/* rcg06072001 Get the chunk associated with a channel. */
Mix_Chunk *Mix_GetChunk(int channel)
{
Mix_Chunk *retval = NULL;
if ((channel >= 0) && (channel < num_channels)) {
retval = mix_channel[channel].chunk;
}
return(retval);
}
780
781
782
783
784
785
786
787
788
/* Close the mixer, halting all playing audio */
void Mix_CloseAudio(void)
{
if ( audio_opened ) {
if ( audio_opened == 1 ) {
close_music();
Mix_HaltChannel(-1);
SDL_CloseAudio();
SDL_DestroyMutex(mixer_lock);
789
790
free(mix_channel);
mix_channel = NULL;
791
792
793
794
795
796
797
798
}
--audio_opened;
}
}
/* Pause a particular channel (or all) */
void Mix_Pause(int which)
{
799
Uint32 sdl_ticks = SDL_GetTicks();
800
801
802
if ( which == -1 ) {
int i;
803
for ( i=0; i<num_channels; ++i ) {
804
805
if ( mix_channel[i].playing > 0 ) {
mix_channel[i].paused = sdl_ticks;
806
807
808
}
}
} else {
809
810
if ( mix_channel[which].playing > 0 ) {
mix_channel[which].paused = sdl_ticks;
811
812
813
814
815
816
817
}
}
}
/* Resume a paused channel */
void Mix_Resume(int which)
{
818
Uint32 sdl_ticks = SDL_GetTicks();
819
820
821
if ( which == -1 ) {
int i;
822
SDL_mutexP(mixer_lock);
823
for ( i=0; i<num_channels; ++i ) {
824
825
826
827
if ( mix_channel[i].playing > 0 ) {
if(mix_channel[i].expire > 0)
mix_channel[i].expire += sdl_ticks - mix_channel[i].paused;
mix_channel[i].paused = 0;
828
829
}
}
830
SDL_mutexV(mixer_lock);
831
} else {
832
SDL_mutexP(mixer_lock);
833
834
835
836
if ( mix_channel[which].playing > 0 ) {
if(mix_channel[which].expire > 0)
mix_channel[which].expire += sdl_ticks - mix_channel[which].paused;
mix_channel[which].paused = 0;
837
}
838
SDL_mutexV(mixer_lock);
839
840
}
}
841
842
843
int Mix_Paused(int which)
{
844
if ( which > num_channels )
845
return(0);
846
847
848
849
if ( which < 0 ) {
int status = 0;
int i;
for( i=0; i < num_channels; ++i ) {
850
if ( mix_channel[i].paused ) {
851
852
853
854
855
++ status;
}
}
return(status);
} else {
856
return(mix_channel[which].paused != 0);
857
}
858
859
}
860
861
862
863
864
865
866
/* Change the group of a channel */
int Mix_GroupChannel(int which, int tag)
{
if ( which < 0 || which > num_channels )
return(0);
SDL_mutexP(mixer_lock);
867
mix_channel[which].tag = tag;
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
SDL_mutexV(mixer_lock);
return(1);
}
/* Assign several consecutive channels to a group */
int Mix_GroupChannels(int from, int to, int tag)
{
int status = 0;
for( ; from <= to; ++ from ) {
status += Mix_GroupChannel(from, tag);
}
return(status);
}
/* Finds the first available channel in a group of channels */
int Mix_GroupAvailable(int tag)
{
int i;
for( i=0; i < num_channels; i ++ ) {
887
888
if ( ((tag == -1) || (tag == mix_channel[i].tag)) &&
(mix_channel[i].playing <= 0) )
889
890
891
892
893
894
895
896
897
898
return i;
}
return(-1);
}
int Mix_GroupCount(int tag)
{
int count = 0;
int i;
for( i=0; i < num_channels; i ++ ) {
899
if ( mix_channel[i].tag==tag || tag==-1 )
900
901
902
903
++ count;
}
return(count);
}
904
905
906
907
908
909
910
911
/* Finds the "oldest" sample playing in a group of channels */
int Mix_GroupOldest(int tag)
{
int chan = -1;
Uint32 mintime = SDL_GetTicks();
int i;
for( i=0; i < num_channels; i ++ ) {
912
913
914
if ( (mix_channel[i].tag==tag || tag==-1) && mix_channel[i].playing > 0
&& mix_channel[i].start_time <= mintime ) {
mintime = mix_channel[i].start_time;
915
916
917
918
919
920
921
922
923
924
925
926
927
chan = i;
}
}
return(chan);
}
/* Finds the "most recent" (i.e. last) sample playing in a group of channels */
int Mix_GroupNewer(int tag)
{
int chan = -1;
Uint32 maxtime = 0;
int i;
for( i=0; i < num_channels; i ++ ) {
928
929
930
if ( (mix_channel[i].tag==tag || tag==-1) && mix_channel[i].playing > 0
&& mix_channel[i].start_time >= maxtime ) {
maxtime = mix_channel[i].start_time;
931
932
933
934
935
chan = i;
}
}
return(chan);
}