/
mixer.c
1208 lines (1046 loc) · 27.7 KB
1
/*
2
3
SDL_mixer: An audio mixer library based on the SDL library
Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
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
20
slouken@libsdl.org
21
22
*/
23
/* $Id$ */
24
25
26
27
28
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
29
30
#include "SDL_mutex.h"
#include "SDL_endian.h"
31
#include "SDL_timer.h"
32
33
#include "SDL_mixer.h"
34
35
36
37
#include "load_aiff.h"
#include "load_voc.h"
/* Magic numbers for various audio file formats */
38
#define RIFF 0x46464952 /* "RIFF" */
39
40
#define WAVE 0x45564157 /* "WAVE" */
#define FORM 0x4d524f46 /* "FORM" */
41
42
43
44
45
static int audio_opened = 0;
static SDL_AudioSpec mixer;
static SDL_mutex *mixer_lock;
46
47
48
49
50
51
52
53
54
typedef struct _Mix_effectinfo
{
Mix_EffectFunc_t callback;
Mix_EffectDone_t done_callback;
void *udata;
struct _Mix_effectinfo *next;
} effect_info;
55
56
57
58
59
60
61
static struct _Mix_Channel {
Mix_Chunk *chunk;
int playing;
int paused;
Uint8 *samples;
int volume;
int looping;
62
int tag;
63
Uint32 expire;
64
Uint32 start_time;
65
66
Mix_Fading fading;
int fade_volume;
67
Uint32 fade_length;
68
Uint32 ticks_fade;
69
effect_info *effects;
70
} *mix_channel = NULL;
71
72
73
static effect_info *posteffects = NULL;
74
static int num_channels;
75
static int reserved_channels = 0;
76
77
78
79
/* Support for hooking into the mixer callback system */
static void (*mix_postmix)(void *udata, Uint8 *stream, int len) = NULL;
80
static void *mix_postmix_data = NULL;
81
82
83
84
/* rcg07062001 callback to alert when channels are done playing. */
static void (*channel_done_callback)(int channel) = NULL;
85
86
87
88
/* Music function declarations */
extern int open_music(SDL_AudioSpec *mixer);
extern void close_music(void);
89
/* Support for user defined music functions, plus the default one */
90
extern int volatile music_active;
91
92
extern void music_mixer(void *udata, Uint8 *stream, int len);
static void (*mix_music)(void *udata, Uint8 *stream, int len) = music_mixer;
93
static void *music_data = NULL;
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
/* rcg06192001 get linked library's version. */
const SDL_version *Mix_Linked_Version(void)
{
static SDL_version linked_mixver;
MIX_VERSION(&linked_mixver);
return(&linked_mixver);
}
/* rcg06122001 Cleanup effect callbacks. */
static void Mix_ChannelDonePlaying(int channel)
{
if (channel_done_callback) {
channel_done_callback(channel);
}
Mix_UnregisterAllEffects(channel);
}
static void *Mix_DoEffects(int chan, void *snd, int len)
{
int posteffect = (chan == MIX_CHANNEL_POST);
effect_info *e = ((posteffect) ? posteffects : mix_channel[chan].effects);
void *buf = snd;
if (e != NULL) { /* are there any registered effects? */
/* if this is the postmix, we can just overwrite the original. */
if (!posteffect) {
buf = malloc(len);
if (buf == NULL) {
return(snd);
}
memcpy(buf, snd, len);
}
for (; e != NULL; e = e->next) {
if (e->callback != NULL) {
e->callback(chan, buf, len, e->udata);
}
}
}
/* be sure to free() the return value if != snd ... */
return(buf);
}
144
145
146
/* Mixing function */
static void mix_channels(void *udata, Uint8 *stream, int len)
{
147
Uint8 *mix_input;
148
int i, mixable, volume;
149
Uint32 sdl_ticks;
150
151
/* Mix the music (must be done before the channels are added) */
152
if ( music_active || (mix_music != music_mixer) ) {
153
154
155
mix_music(music_data, stream, len);
}
156
157
/* Grab the channels we need to mix */
SDL_mutexP(mixer_lock);
158
159
sdl_ticks = SDL_GetTicks();
for ( i=0; i<num_channels; ++i ) {
160
161
if( ! mix_channel[i].paused ) {
if ( mix_channel[i].expire > 0 && mix_channel[i].expire < sdl_ticks ) {
162
/* Expiration delay for that channel is reached */
163
164
165
166
167
168
169
170
171
172
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 */
173
}
174
mix_channel[i].fading = MIX_NO_FADING;
175
} else {
176
177
178
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 );
179
} else {
180
Mix_Volume(i, (mix_channel[i].fade_volume * ticks) / mix_channel[i].fade_length );
181
}
182
183
}
}
184
185
186
if ( mix_channel[i].playing > 0 ) {
volume = (mix_channel[i].volume*mix_channel[i].chunk->volume) / MIX_MAX_VOLUME;
mixable = mix_channel[i].playing;
187
188
189
if ( mixable > len ) {
mixable = len;
}
190
191
192
193
194
195
mix_input = Mix_DoEffects(i, mix_channel[i].samples, mixable);
SDL_MixAudio(stream,mix_input,mixable,volume);
if (mix_input != mix_channel[i].samples)
free(mix_input);
196
197
mix_channel[i].samples += mixable;
mix_channel[i].playing -= mixable;
198
199
/* If looping the sample and we are at its end, make sure
we will still return a full buffer */
200
while ( mix_channel[i].looping && mixable < len ) {
201
int remaining = len - mixable;
202
int alen = mix_channel[i].chunk->alen;
203
204
205
if (remaining > alen) {
remaining = alen;
}
206
207
208
209
210
211
mix_input = Mix_DoEffects(i, mix_channel[i].chunk->abuf, remaining);
SDL_MixAudio(stream+mixable, mix_input, remaining, volume);
if (mix_input != mix_channel[i].chunk->abuf)
free(mix_input);
212
213
214
--mix_channel[i].looping;
mix_channel[i].samples = mix_channel[i].chunk->abuf + remaining;
mix_channel[i].playing = mix_channel[i].chunk->alen - remaining;
215
216
mixable += remaining;
}
217
218
219
220
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;
221
}
222
}
223
224
/* rcg06072001 Alert app if channel is done playing. */
225
226
if (!mix_channel[i].playing) {
Mix_ChannelDonePlaying(i);
227
}
228
229
230
}
}
}
231
232
233
234
/* rcg06122001 run posteffects... */
Mix_DoEffects(MIX_CHANNEL_POST, stream, len);
235
236
237
if ( mix_postmix ) {
mix_postmix(mix_postmix_data, stream, len);
}
238
239
240
241
242
243
244
245
246
247
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);
}
248
249
250
void _Mix_InitEffects(void);
251
/* Open the mixer with a certain desired audio format */
252
int Mix_OpenAudio(int frequency, Uint16 format, int nchannels, int chunksize)
253
254
255
256
257
258
259
260
261
262
263
264
265
{
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;
266
desired.channels = nchannels;
267
268
269
270
271
272
273
274
275
276
277
278
279
280
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();
281
#ifndef macintosh /* Hmm.. what implications does this have? */
282
283
284
285
286
if ( mixer_lock == NULL ) {
SDL_CloseAudio();
SDL_SetError("Unable to create mixer lock");
return(-1);
}
287
#endif
288
289
290
291
292
293
294
/* Initialize the music players */
if ( open_music(&mixer) < 0 ) {
SDL_CloseAudio();
SDL_DestroyMutex(mixer_lock);
return(-1);
}
295
296
num_channels = MIX_CHANNELS;
297
mix_channel = (struct _Mix_Channel *) malloc(num_channels * sizeof(struct _Mix_Channel));
298
299
/* Clear out the audio channels */
300
for ( i=0; i<num_channels; ++i ) {
301
302
303
304
305
306
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;
307
mix_channel[i].effects = NULL;
308
309
}
Mix_VolumeMusic(SDL_MIX_MAXVOLUME);
310
311
312
_Mix_InitEffects();
313
314
315
316
317
audio_opened = 1;
SDL_PauseAudio(0);
return(0);
}
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
/* 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);
335
mix_channel = (struct _Mix_Channel *) realloc(mix_channel, numchans * sizeof(struct _Mix_Channel));
336
337
338
339
if ( numchans > num_channels ) {
/* Initialize the new channels */
int i;
for(i=num_channels; i < numchans; i++) {
340
341
342
343
344
345
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;
346
mix_channel[i].effects = NULL;
347
348
349
350
351
352
353
}
}
num_channels = numchans;
SDL_mutexV(mixer_lock);
return(num_channels);
}
354
355
356
357
358
359
360
361
362
363
/* 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;
}
364
if ( channels ) {
365
366
367
368
369
370
*channels = mixer.channels;
}
}
return(audio_opened);
}
371
372
373
374
375
376
/*
* !!! FIXME: Ideally, we want a Mix_LoadSample_RW(), which will handle the
* generic setup, then call the correct file format loader.
*/
377
378
379
/* Load a wave file */
Mix_Chunk *Mix_LoadWAV_RW(SDL_RWops *src, int freesrc)
{
380
Uint32 magic;
381
Mix_Chunk *chunk;
382
SDL_AudioSpec wavespec, *loaded;
383
SDL_AudioCVT wavecvt;
384
int samplesize;
385
386
387
/* rcg06012001 Make sure src is valid */
if ( ! src ) {
388
SDL_SetError("Mix_LoadWAV_RW with NULL src");
389
390
391
return(NULL);
}
392
393
394
/* Make sure audio has been opened */
if ( ! audio_opened ) {
SDL_SetError("Audio device hasn't been opened");
395
if ( freesrc && src ) {
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
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);
}
411
412
413
/* Find out what kind of audio file this is */
magic = SDL_ReadLE32(src);
/* Seek backwards for compatibility with older loaders */
414
SDL_RWseek(src, -(int)sizeof(Uint32), SEEK_CUR);
415
416
417
switch (magic) {
case WAVE:
418
case RIFF:
419
420
421
422
423
424
425
426
427
428
429
430
431
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 ) {
432
433
434
free(chunk);
return(NULL);
}
435
436
437
438
439
440
441
442
443
444
445
446
447
448
#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);
}
449
450
samplesize = ((wavespec.format & 0xFF)/8)*wavespec.channels;
wavecvt.len = chunk->alen & ~(samplesize-1);
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
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);
}
467
chunk->allocated = 1;
468
469
470
471
472
473
chunk->abuf = wavecvt.buf;
chunk->alen = wavecvt.len_cvt;
chunk->volume = MIX_MAX_VOLUME;
return(chunk);
}
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
/* 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);
}
509
510
511
512
513
514
515
516
/* 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 */
517
518
519
520
521
522
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;
}
523
}
524
SDL_mutexV(mixer_lock);
525
526
527
}
/* Actually free the chunk */
528
529
530
if ( chunk->allocated ) {
free(chunk->abuf);
}
531
532
533
534
free(chunk);
}
}
535
536
537
538
539
540
541
542
543
544
545
546
547
/* 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();
}
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
/* 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);
}
570
571
572
573
574
575
576
577
void Mix_ChannelFinished(void (*channel_finished)(int channel))
{
SDL_LockAudio();
channel_done_callback = channel_finished;
SDL_UnlockAudio();
}
578
579
580
581
582
583
/* 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)
{
584
585
if (num > num_channels)
num = num_channels;
586
587
588
589
590
591
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.
592
593
'ticks' is the number of milliseconds at most to play the sample, or -1
if there is no limit.
594
595
Returns which channel was used to play the sound.
*/
596
int Mix_PlayChannelTimed(int which, Mix_Chunk *chunk, int loops, int ticks)
597
598
599
600
601
602
603
604
605
606
607
608
609
{
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 ) {
610
for ( i=reserved_channels; i<num_channels; ++i ) {
611
if ( mix_channel[i].playing <= 0 )
612
613
break;
}
614
if ( i == num_channels ) {
615
616
617
618
619
620
621
622
which = -1;
} else {
which = i;
}
}
/* Queue up the audio data for this channel */
if ( which >= 0 ) {
623
Uint32 sdl_ticks = SDL_GetTicks();
624
625
if (Mix_Playing(which))
Mix_ChannelDonePlaying(which);
626
627
628
629
630
631
632
633
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;
634
635
636
637
638
639
640
641
}
}
SDL_mutexV(mixer_lock);
/* Return the channel on which the sound is being played */
return(which);
}
642
643
644
645
646
647
648
649
650
651
652
653
/* 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);
654
mix_channel[which].expire = (ticks>0) ? (SDL_GetTicks() + ticks) : 0;
655
656
657
658
659
660
SDL_mutexV(mixer_lock);
++ status;
}
return(status);
}
661
/* Fade in a sound on a channel, over ms milliseconds */
662
int Mix_FadeInChannelTimed(int which, Mix_Chunk *chunk, int loops, int ms, int ticks)
663
664
665
666
667
668
669
670
671
672
673
674
675
{
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 ) {
676
for ( i=reserved_channels; i<num_channels; ++i ) {
677
if ( mix_channel[i].playing <= 0 )
678
679
break;
}
680
if ( i == num_channels ) {
681
682
683
684
685
686
687
688
which = -1;
} else {
which = i;
}
}
/* Queue up the audio data for this channel */
if ( which >= 0 ) {
689
Uint32 sdl_ticks = SDL_GetTicks();
690
691
if (Mix_Playing(which))
Mix_ChannelDonePlaying(which);
692
693
694
695
696
697
698
699
700
701
702
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;
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
}
}
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;
719
for ( i=0; i<num_channels; ++i ) {
720
721
prev_volume += Mix_Volume(i, volume);
}
722
prev_volume /= num_channels;
723
} else {
724
prev_volume = mix_channel[which].volume;
725
726
727
728
729
if ( volume >= 0 ) {
if ( volume > SDL_MIX_MAXVOLUME ) {
volume = SDL_MIX_MAXVOLUME;
}
mix_channel[which].volume = volume;
730
}
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
}
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 ) {
755
for ( i=0; i<num_channels; ++i ) {
756
757
758
759
Mix_HaltChannel(i);
}
} else {
SDL_mutexP(mixer_lock);
760
761
if (mix_channel[which].playing) {
Mix_ChannelDonePlaying(which);
762
mix_channel[which].playing = 0;
763
}
764
765
766
767
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;
768
769
770
771
772
SDL_mutexV(mixer_lock);
}
return(0);
}
773
774
775
776
777
778
/* Halt playing of a particular group of channels */
int Mix_HaltGroup(int tag)
{
int i;
for ( i=0; i<num_channels; ++i ) {
779
if( mix_channel[i].tag == tag ) {
780
781
782
783
784
785
Mix_HaltChannel(i);
}
}
return(0);
}
786
787
788
789
790
791
/* Fade out a channel and then stop it automatically */
int Mix_FadeOutChannel(int which, int ms)
{
int status;
status = 0;
792
793
794
if ( audio_opened ) {
if ( which == -1 ) {
int i;
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
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);
812
813
814
815
816
}
}
return(status);
}
817
818
819
820
821
822
/* 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 ) {
823
if( mix_channel[i].tag == tag ) {
824
825
826
827
828
829
status += Mix_FadeOutChannel(i,ms);
}
}
return(status);
}
830
831
Mix_Fading Mix_FadingChannel(int which)
{
832
return mix_channel[which].fading;
833
834
}
835
/* Check the status of a specific channel.
836
If the specified mix_channel is -1, check all mix channels.
837
838
839
840
841
842
843
844
845
*/
int Mix_Playing(int which)
{
int status;
status = 0;
if ( which == -1 ) {
int i;
846
for ( i=0; i<num_channels; ++i ) {
847
848
849
if ((mix_channel[i].playing > 0) ||
(mix_channel[i].looping > 0))
{
850
851
852
853
++status;
}
}
} else {
854
855
856
if ((mix_channel[which].playing > 0) ||
(mix_channel[which].looping > 0))
{
857
858
859
860
861
862
++status;
}
}
return(status);
}
863
864
865
866
867
868
869
870
871
872
873
874
/* 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);
}
875
876
877
/* Close the mixer, halting all playing audio */
void Mix_CloseAudio(void)
{
878
879
int i;
880
881
if ( audio_opened ) {
if ( audio_opened == 1 ) {
882
883
884
885
for (i = 0; i < num_channels; i++) {
Mix_UnregisterAllEffects(i);
}
Mix_UnregisterAllEffects(MIX_CHANNEL_POST);
886
887
888
889
close_music();
Mix_HaltChannel(-1);
SDL_CloseAudio();
SDL_DestroyMutex(mixer_lock);
890
891
free(mix_channel);
mix_channel = NULL;
892
893
894
895
896
897
898
899
}
--audio_opened;
}
}
/* Pause a particular channel (or all) */
void Mix_Pause(int which)
{
900
Uint32 sdl_ticks = SDL_GetTicks();
901
902
903
if ( which == -1 ) {
int i;
904
for ( i=0; i<num_channels; ++i ) {
905
906
if ( mix_channel[i].playing > 0 ) {
mix_channel[i].paused = sdl_ticks;
907
908
909
}
}
} else {
910
911
if ( mix_channel[which].playing > 0 ) {
mix_channel[which].paused = sdl_ticks;
912
913
914
915
916
917
918
}
}
}
/* Resume a paused channel */
void Mix_Resume(int which)
{
919
Uint32 sdl_ticks = SDL_GetTicks();
920
921
922
if ( which == -1 ) {
int i;
923
SDL_mutexP(mixer_lock);
924
for ( i=0; i<num_channels; ++i ) {
925
926
927
928
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;
929
930
}
}
931
SDL_mutexV(mixer_lock);
932
} else {
933
SDL_mutexP(mixer_lock);
934
935
936
937
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;
938
}
939
SDL_mutexV(mixer_lock);
940
941
}
}
942
943
944
int Mix_Paused(int which)
{
945
if ( which > num_channels )
946
return(0);
947
948
949
950
if ( which < 0 ) {
int status = 0;
int i;
for( i=0; i < num_channels; ++i ) {
951
if ( mix_channel[i].paused ) {
952
953
954
955
956
++ status;
}
}
return(status);
} else {
957
return(mix_channel[which].paused != 0);
958
}
959
960
}
961
962
963
964
965
966
967
/* 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);
968
mix_channel[which].tag = tag;
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
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 ++ ) {
988
989
if ( ((tag == -1) || (tag == mix_channel[i].tag)) &&
(mix_channel[i].playing <= 0) )
990
991
992
993
994
995
996
997
998
999
return i;
}
return(-1);
}
int Mix_GroupCount(int tag)
{
int count = 0;
int i;
for( i=0; i < num_channels; i ++ ) {
1000
if ( mix_channel[i].tag==tag || tag==-1 )