mixer.c
author Sam Lantinga <slouken@libsdl.org>
Fri, 03 May 2002 04:09:27 +0000
changeset 172 fb810079d5f1
parent 164 226caa8bd762
child 174 f9648fd517de
permissions -rw-r--r--
Ryan Gordon - Thu May 2 21:08:48 PDT 2002
* Fixed deadlock introduced in the last release
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/*
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    SDL_mixer:  An audio mixer library based on the SDL library
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    Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga
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    This library is free software; you can redistribute it and/or
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    modify it under the terms of the GNU Library General Public
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    License as published by the Free Software Foundation; either
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    version 2 of the License, or (at your option) any later version.
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    This library is distributed in the hope that it will be useful,
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    but WITHOUT ANY WARRANTY; without even the implied warranty of
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    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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    Library General Public License for more details.
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    You should have received a copy of the GNU Library General Public
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    License along with this library; if not, write to the Free
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    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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    Sam Lantinga
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    slouken@libsdl.org
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*/
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/* $Id$ */
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "SDL_mutex.h"
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#include "SDL_endian.h"
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#include "SDL_timer.h"
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#include "SDL_mixer.h"
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#include "load_aiff.h"
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#include "load_voc.h"
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/* Magic numbers for various audio file formats */
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#define RIFF		0x46464952		/* "RIFF" */
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#define WAVE		0x45564157		/* "WAVE" */
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#define FORM		0x4d524f46		/* "FORM" */
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static int audio_opened = 0;
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static SDL_AudioSpec mixer;
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typedef struct _Mix_effectinfo
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{
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	Mix_EffectFunc_t callback;
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	Mix_EffectDone_t done_callback;
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	void *udata;
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	struct _Mix_effectinfo *next;
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} effect_info;
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static struct _Mix_Channel {
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	Mix_Chunk *chunk;
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	int playing;
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	int paused;
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	Uint8 *samples;
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	int volume;
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	int looping;
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	int tag;
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	Uint32 expire;
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	Uint32 start_time;
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	Mix_Fading fading;
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	int fade_volume;
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	Uint32 fade_length;
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	Uint32 ticks_fade;
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	effect_info *effects;
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} *mix_channel = NULL;
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static effect_info *posteffects = NULL;
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static int num_channels;
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static int reserved_channels = 0;
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/* Support for hooking into the mixer callback system */
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static void (*mix_postmix)(void *udata, Uint8 *stream, int len) = NULL;
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static void *mix_postmix_data = NULL;
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/* rcg07062001 callback to alert when channels are done playing. */
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static void (*channel_done_callback)(int channel) = NULL;
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/* Music function declarations */
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extern int open_music(SDL_AudioSpec *mixer);
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extern void close_music(void);
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/* Support for user defined music functions, plus the default one */
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extern int volatile music_active;
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extern void music_mixer(void *udata, Uint8 *stream, int len);
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static void (*mix_music)(void *udata, Uint8 *stream, int len) = music_mixer;
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static void *music_data = NULL;
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/* rcg06192001 get linked library's version. */
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const SDL_version *Mix_Linked_Version(void)
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{
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	static SDL_version linked_mixver;
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	MIX_VERSION(&linked_mixver);
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	return(&linked_mixver);
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}
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static int _Mix_remove_all_effects(int channel, effect_info **e);
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/*
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 * rcg06122001 Cleanup effect callbacks.
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 *  MAKE SURE SDL_LockAudio() is called before this (or you're in the
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 *   audio callback).
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 */
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static void _Mix_channel_done_playing(int channel)
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{
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	if (channel_done_callback) {
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	    channel_done_callback(channel);
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	}
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	/*
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	 * Call internal function directly, to avoid locking audio from
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	 *   inside audio callback.
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	 */
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	_Mix_remove_all_effects(channel, &mix_channel[channel].effects);
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}
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static void *Mix_DoEffects(int chan, void *snd, int len)
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{
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	int posteffect = (chan == MIX_CHANNEL_POST);
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	effect_info *e = ((posteffect) ? posteffects : mix_channel[chan].effects);
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	void *buf = snd;
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	if (e != NULL) {    /* are there any registered effects? */
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		/* if this is the postmix, we can just overwrite the original. */
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		if (!posteffect) {
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			buf = malloc(len);
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			if (buf == NULL) {
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				return(snd);
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			}
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		    memcpy(buf, snd, len);
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		}
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		for (; e != NULL; e = e->next) {
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			if (e->callback != NULL) {
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				e->callback(chan, buf, len, e->udata);
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			}
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		}
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	}
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	/* be sure to free() the return value if != snd ... */
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	return(buf);
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}
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/* Mixing function */
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static void mix_channels(void *udata, Uint8 *stream, int len)
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{
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	Uint8 *mix_input;
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	int i, mixable, volume;
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	Uint32 sdl_ticks;
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	/* Mix the music (must be done before the channels are added) */
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	if ( music_active || (mix_music != music_mixer) ) {
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		mix_music(music_data, stream, len);
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	}
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	/* Mix any playing channels... */
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	sdl_ticks = SDL_GetTicks();
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	for ( i=0; i<num_channels; ++i ) {
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		if( ! mix_channel[i].paused ) {
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			if ( mix_channel[i].expire > 0 && mix_channel[i].expire < sdl_ticks ) {
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				/* Expiration delay for that channel is reached */
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				mix_channel[i].playing = 0;
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				mix_channel[i].fading = MIX_NO_FADING;
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				mix_channel[i].expire = 0;
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			} else if ( mix_channel[i].fading != MIX_NO_FADING ) {
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				Uint32 ticks = sdl_ticks - mix_channel[i].ticks_fade;
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				if( ticks > mix_channel[i].fade_length ) {
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					if( mix_channel[i].fading == MIX_FADING_OUT ) {
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						mix_channel[i].playing = 0;
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						mix_channel[i].expire = 0;
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						Mix_Volume(i, mix_channel[i].fading); /* Restore the volume */
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					}
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					mix_channel[i].fading = MIX_NO_FADING;
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				} else {
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					if( mix_channel[i].fading == MIX_FADING_OUT ) {
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						Mix_Volume(i, (mix_channel[i].fade_volume * (mix_channel[i].fade_length-ticks))
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								   / mix_channel[i].fade_length );
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					} else {
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						Mix_Volume(i, (mix_channel[i].fade_volume * ticks) / mix_channel[i].fade_length );
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					}
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				}
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			}
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			if ( mix_channel[i].playing > 0 ) {
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				volume = (mix_channel[i].volume*mix_channel[i].chunk->volume) / MIX_MAX_VOLUME;
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				mixable = mix_channel[i].playing;
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				if ( mixable > len ) {
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					mixable = len;
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				}
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				mix_input = Mix_DoEffects(i, mix_channel[i].samples, mixable);
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				SDL_MixAudio(stream,mix_input,mixable,volume);
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				if (mix_input != mix_channel[i].samples)
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					free(mix_input);
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				mix_channel[i].samples += mixable;
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				mix_channel[i].playing -= mixable;
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				/* If looping the sample and we are at its end, make sure
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				   we will still return a full buffer */
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				while ( mix_channel[i].looping && mixable < len ) {
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				    	int remaining = len - mixable;
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					int alen = mix_channel[i].chunk->alen;
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				    	if (remaining > alen) {
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						remaining = alen;
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				    	}
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					mix_input = Mix_DoEffects(i, mix_channel[i].chunk->abuf, remaining);
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					SDL_MixAudio(stream+mixable, mix_input, remaining, volume);
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					if (mix_input != mix_channel[i].chunk->abuf)
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						free(mix_input);
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					--mix_channel[i].looping;
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					mix_channel[i].samples = mix_channel[i].chunk->abuf + remaining;
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					mix_channel[i].playing = mix_channel[i].chunk->alen - remaining;
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					mixable += remaining;
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				}
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				if ( ! mix_channel[i].playing && mix_channel[i].looping ) {
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					if ( --mix_channel[i].looping ) {
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						mix_channel[i].samples = mix_channel[i].chunk->abuf;
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						mix_channel[i].playing = mix_channel[i].chunk->alen;
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					}
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				}
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				/* rcg06072001 Alert app if channel is done playing. */
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				if (!mix_channel[i].playing) {
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					_Mix_channel_done_playing(i);
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				}
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			}
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		}
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	}
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	/* rcg06122001 run posteffects... */
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	Mix_DoEffects(MIX_CHANNEL_POST, stream, len);
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	if ( mix_postmix ) {
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		mix_postmix(mix_postmix_data, stream, len);
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	}
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}
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static void PrintFormat(char *title, SDL_AudioSpec *fmt)
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{
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	printf("%s: %d bit %s audio (%s) at %u Hz\n", title, (fmt->format&0xFF),
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			(fmt->format&0x8000) ? "signed" : "unsigned",
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			(fmt->channels > 1) ? "stereo" : "mono", fmt->freq);
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}
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void _Mix_InitEffects(void);
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/* Open the mixer with a certain desired audio format */
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int Mix_OpenAudio(int frequency, Uint16 format, int nchannels, int chunksize)
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{
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	int i;
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	SDL_AudioSpec desired;
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	/* If the mixer is already opened, increment open count */
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	if ( audio_opened ) {
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	    ++audio_opened;
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	    return(0);
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	}
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	/* Set the desired format and frequency */
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	desired.freq = frequency;
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	desired.format = format;
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	desired.channels = nchannels;
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	desired.samples = chunksize;
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	desired.callback = mix_channels;
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	desired.userdata = NULL;
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	/* Accept nearly any audio format */
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	if ( SDL_OpenAudio(&desired, &mixer) < 0 ) {
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		return(-1);
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	}
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#if 0
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	PrintFormat("Audio device", &mixer);
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#endif
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	/* Initialize the music players */
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	if ( open_music(&mixer) < 0 ) {
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		SDL_CloseAudio();
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		return(-1);
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	}
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	num_channels = MIX_CHANNELS;
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	mix_channel = (struct _Mix_Channel *) malloc(num_channels * sizeof(struct _Mix_Channel));
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	/* Clear out the audio channels */
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	for ( i=0; i<num_channels; ++i ) {
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		mix_channel[i].chunk = NULL;
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		mix_channel[i].playing = 0;
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		mix_channel[i].looping = 0;
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		mix_channel[i].volume = SDL_MIX_MAXVOLUME;
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		mix_channel[i].tag = -1;
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		mix_channel[i].expire = 0;
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		mix_channel[i].effects = NULL;
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	}
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	Mix_VolumeMusic(SDL_MIX_MAXVOLUME);
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	_Mix_InitEffects();
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	audio_opened = 1;
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	SDL_PauseAudio(0);
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	return(0);
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}
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/* Dynamically change the number of channels managed by the mixer.
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   If decreasing the number of channels, the upper channels are
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   stopped.
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 */
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int Mix_AllocateChannels(int numchans)
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{
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	if ( numchans<0 || numchans==num_channels )
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		return(num_channels);
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	if ( numchans < num_channels ) {
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		/* Stop the affected channels */
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		int i;
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		for(i=numchans; i < num_channels; i++) {
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			Mix_HaltChannel(i);
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		}
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	}
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	SDL_LockAudio();
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	mix_channel = (struct _Mix_Channel *) realloc(mix_channel, numchans * sizeof(struct _Mix_Channel));
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	if ( numchans > num_channels ) {
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		/* Initialize the new channels */
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		int i;
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		for(i=num_channels; i < numchans; i++) {
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			mix_channel[i].chunk = NULL;
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			mix_channel[i].playing = 0;
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			mix_channel[i].looping = 0;
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			mix_channel[i].volume = SDL_MIX_MAXVOLUME;
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			mix_channel[i].tag = -1;
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			mix_channel[i].expire = 0;
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			mix_channel[i].effects = NULL;
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		}
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	}
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	num_channels = numchans;
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	SDL_UnlockAudio();
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	return(num_channels);
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}
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/* Return the actual mixer parameters */
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int Mix_QuerySpec(int *frequency, Uint16 *format, int *channels)
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{
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	if ( audio_opened ) {
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		if ( frequency ) {
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			*frequency = mixer.freq;
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		}
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		if ( format ) {
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			*format = mixer.format;
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		}
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		if ( channels ) {
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			*channels = mixer.channels;
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		}
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	}
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	return(audio_opened);
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}
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/*
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 * !!! FIXME: Ideally, we want a Mix_LoadSample_RW(), which will handle the
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 *             generic setup, then call the correct file format loader.
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 */
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/* Load a wave file */
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Mix_Chunk *Mix_LoadWAV_RW(SDL_RWops *src, int freesrc)
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{
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	Uint32 magic;
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	Mix_Chunk *chunk;
slouken@111
   376
	SDL_AudioSpec wavespec, *loaded;
slouken@0
   377
	SDL_AudioCVT wavecvt;
slouken@41
   378
	int samplesize;
slouken@0
   379
slouken@91
   380
	/* rcg06012001 Make sure src is valid */
slouken@91
   381
	if ( ! src ) {
slouken@111
   382
		SDL_SetError("Mix_LoadWAV_RW with NULL src");
slouken@91
   383
		return(NULL);
slouken@91
   384
	}
slouken@91
   385
slouken@0
   386
	/* Make sure audio has been opened */
slouken@0
   387
	if ( ! audio_opened ) {
slouken@0
   388
		SDL_SetError("Audio device hasn't been opened");
slouken@89
   389
		if ( freesrc && src ) {
slouken@0
   390
			SDL_RWclose(src);
slouken@0
   391
		}
slouken@0
   392
		return(NULL);
slouken@0
   393
	}
slouken@0
   394
slouken@0
   395
	/* Allocate the chunk memory */
slouken@0
   396
	chunk = (Mix_Chunk *)malloc(sizeof(Mix_Chunk));
slouken@0
   397
	if ( chunk == NULL ) {
slouken@0
   398
		SDL_SetError("Out of memory");
slouken@0
   399
		if ( freesrc ) {
slouken@0
   400
			SDL_RWclose(src);
slouken@0
   401
		}
slouken@0
   402
		return(NULL);
slouken@0
   403
	}
slouken@0
   404
slouken@111
   405
	/* Find out what kind of audio file this is */
slouken@111
   406
	magic = SDL_ReadLE32(src);
slouken@111
   407
	/* Seek backwards for compatibility with older loaders */
slouken@146
   408
	SDL_RWseek(src, -(int)sizeof(Uint32), SEEK_CUR);
slouken@111
   409
slouken@111
   410
	switch (magic) {
slouken@111
   411
		case WAVE:
slouken@117
   412
		case RIFF:
slouken@111
   413
			loaded = SDL_LoadWAV_RW(src, freesrc, &wavespec,
slouken@111
   414
					(Uint8 **)&chunk->abuf, &chunk->alen);
slouken@111
   415
			break;
slouken@111
   416
		case FORM:
slouken@111
   417
			loaded = Mix_LoadAIFF_RW(src, freesrc, &wavespec,
slouken@111
   418
					(Uint8 **)&chunk->abuf, &chunk->alen);
slouken@111
   419
			break;
slouken@111
   420
		default:
slouken@111
   421
			loaded = Mix_LoadVOC_RW(src, freesrc, &wavespec,
slouken@111
   422
					(Uint8 **)&chunk->abuf, &chunk->alen);
slouken@111
   423
			break;
slouken@111
   424
	}
slouken@111
   425
	if ( !loaded ) {
slouken@0
   426
		free(chunk);
slouken@0
   427
		return(NULL);
slouken@0
   428
	}
slouken@91
   429
slouken@0
   430
#if 0
slouken@0
   431
	PrintFormat("Audio device", &mixer);
slouken@0
   432
	PrintFormat("-- Wave file", &wavespec);
slouken@0
   433
#endif
slouken@0
   434
slouken@0
   435
	/* Build the audio converter and create conversion buffers */
slouken@0
   436
	if ( SDL_BuildAudioCVT(&wavecvt,
slouken@0
   437
			wavespec.format, wavespec.channels, wavespec.freq,
slouken@0
   438
			mixer.format, mixer.channels, mixer.freq) < 0 ) {
slouken@0
   439
		SDL_FreeWAV(chunk->abuf);
slouken@0
   440
		free(chunk);
slouken@0
   441
		return(NULL);
slouken@0
   442
	}
slouken@41
   443
	samplesize = ((wavespec.format & 0xFF)/8)*wavespec.channels;
slouken@41
   444
	wavecvt.len = chunk->alen & ~(samplesize-1);
slouken@0
   445
	wavecvt.buf = (Uint8 *)malloc(wavecvt.len*wavecvt.len_mult);
slouken@0
   446
	if ( wavecvt.buf == NULL ) {
slouken@0
   447
		SDL_SetError("Out of memory");
slouken@0
   448
		SDL_FreeWAV(chunk->abuf);
slouken@0
   449
		free(chunk);
slouken@0
   450
		return(NULL);
slouken@0
   451
	}
slouken@0
   452
	memcpy(wavecvt.buf, chunk->abuf, chunk->alen);
slouken@0
   453
	SDL_FreeWAV(chunk->abuf);
slouken@0
   454
slouken@0
   455
	/* Run the audio converter */
slouken@0
   456
	if ( SDL_ConvertAudio(&wavecvt) < 0 ) {
slouken@0
   457
		free(wavecvt.buf);
slouken@0
   458
		free(chunk);
slouken@0
   459
		return(NULL);
slouken@0
   460
	}
slouken@1
   461
	chunk->allocated = 1;
slouken@0
   462
	chunk->abuf = wavecvt.buf;
slouken@0
   463
	chunk->alen = wavecvt.len_cvt;
slouken@0
   464
	chunk->volume = MIX_MAX_VOLUME;
slouken@0
   465
	return(chunk);
slouken@0
   466
}
slouken@0
   467
slouken@1
   468
/* Load a wave file of the mixer format from a memory buffer */
slouken@1
   469
Mix_Chunk *Mix_QuickLoad_WAV(Uint8 *mem)
slouken@1
   470
{
slouken@1
   471
	Mix_Chunk *chunk;
slouken@1
   472
	Uint8 magic[4];
slouken@1
   473
slouken@1
   474
	/* Make sure audio has been opened */
slouken@1
   475
	if ( ! audio_opened ) {
slouken@1
   476
		SDL_SetError("Audio device hasn't been opened");
slouken@1
   477
		return(NULL);
slouken@1
   478
	}
slouken@1
   479
slouken@1
   480
	/* Allocate the chunk memory */
slouken@1
   481
	chunk = (Mix_Chunk *)malloc(sizeof(Mix_Chunk));
slouken@1
   482
	if ( chunk == NULL ) {
slouken@1
   483
		SDL_SetError("Out of memory");
slouken@1
   484
		return(NULL);
slouken@1
   485
	}
slouken@1
   486
slouken@1
   487
	/* Essentially just skip to the audio data (no error checking - fast) */
slouken@1
   488
	chunk->allocated = 0;
slouken@1
   489
	mem += 12; /* WAV header */
slouken@1
   490
	do {
slouken@1
   491
		memcpy(magic, mem, 4);
slouken@1
   492
		mem += 4;
slouken@1
   493
		chunk->alen = ((mem[3]<<24)|(mem[2]<<16)|(mem[1]<<8)|(mem[0]));
slouken@1
   494
		mem += 4;
slouken@1
   495
		chunk->abuf = mem;
slouken@1
   496
		mem += chunk->alen;
slouken@1
   497
	} while ( memcmp(magic, "data", 4) != 0 );
slouken@1
   498
	chunk->volume = MIX_MAX_VOLUME;
slouken@1
   499
slouken@1
   500
	return(chunk);
slouken@1
   501
}
slouken@1
   502
slouken@0
   503
/* Free an audio chunk previously loaded */
slouken@0
   504
void Mix_FreeChunk(Mix_Chunk *chunk)
slouken@0
   505
{
slouken@0
   506
	int i;
slouken@0
   507
slouken@0
   508
	/* Caution -- if the chunk is playing, the mixer will crash */
slouken@0
   509
	if ( chunk ) {
slouken@0
   510
		/* Guarantee that this chunk isn't playing */
slouken@172
   511
		SDL_LockAudio();
slouken@60
   512
		if ( mix_channel ) {
slouken@60
   513
			for ( i=0; i<num_channels; ++i ) {
slouken@60
   514
				if ( chunk == mix_channel[i].chunk ) {
slouken@60
   515
					mix_channel[i].playing = 0;
slouken@60
   516
				}
slouken@0
   517
			}
slouken@0
   518
		}
slouken@172
   519
		SDL_UnlockAudio();
slouken@0
   520
		/* Actually free the chunk */
slouken@1
   521
		if ( chunk->allocated ) {
slouken@1
   522
			free(chunk->abuf);
slouken@1
   523
		}
slouken@0
   524
		free(chunk);
slouken@0
   525
	}
slouken@0
   526
}
slouken@0
   527
slouken@26
   528
/* Set a function that is called after all mixing is performed.
slouken@26
   529
   This can be used to provide real-time visual display of the audio stream
slouken@26
   530
   or add a custom mixer filter for the stream data.
slouken@26
   531
*/
slouken@26
   532
void Mix_SetPostMix(void (*mix_func)
slouken@26
   533
                    (void *udata, Uint8 *stream, int len), void *arg)
slouken@26
   534
{
slouken@26
   535
	SDL_LockAudio();
slouken@26
   536
	mix_postmix_data = arg;
slouken@26
   537
	mix_postmix = mix_func;
slouken@26
   538
	SDL_UnlockAudio();
slouken@26
   539
}
slouken@26
   540
slouken@0
   541
/* Add your own music player or mixer function.
slouken@0
   542
   If 'mix_func' is NULL, the default music player is re-enabled.
slouken@0
   543
 */
slouken@0
   544
void Mix_HookMusic(void (*mix_func)(void *udata, Uint8 *stream, int len),
slouken@0
   545
                                                                void *arg)
slouken@0
   546
{
slouken@0
   547
	SDL_LockAudio();
slouken@0
   548
	if ( mix_func != NULL ) {
slouken@0
   549
		music_data = arg;
slouken@0
   550
		mix_music = mix_func;
slouken@0
   551
	} else {
slouken@0
   552
		music_data = NULL;
slouken@0
   553
		mix_music = music_mixer;
slouken@0
   554
	}
slouken@0
   555
	SDL_UnlockAudio();
slouken@0
   556
}
slouken@0
   557
slouken@0
   558
void *Mix_GetMusicHookData(void)
slouken@0
   559
{
slouken@0
   560
	return(music_data);
slouken@0
   561
}
slouken@0
   562
slouken@92
   563
void Mix_ChannelFinished(void (*channel_finished)(int channel))
slouken@92
   564
{
slouken@172
   565
	SDL_LockAudio();
slouken@172
   566
	channel_done_callback = channel_finished;
slouken@172
   567
	SDL_UnlockAudio();
slouken@92
   568
}
slouken@92
   569
slouken@92
   570
slouken@0
   571
/* Reserve the first channels (0 -> n-1) for the application, i.e. don't allocate
slouken@0
   572
   them dynamically to the next sample if requested with a -1 value below.
slouken@0
   573
   Returns the number of reserved channels.
slouken@0
   574
 */
slouken@0
   575
int Mix_ReserveChannels(int num)
slouken@0
   576
{
megastep@7
   577
	if (num > num_channels)
megastep@7
   578
		num = num_channels;
slouken@0
   579
	reserved_channels = num;
slouken@0
   580
	return num;
slouken@0
   581
}
slouken@0
   582
slouken@0
   583
/* Play an audio chunk on a specific channel.
slouken@0
   584
   If the specified channel is -1, play on the first free channel.
megastep@7
   585
   'ticks' is the number of milliseconds at most to play the sample, or -1
megastep@7
   586
   if there is no limit.
slouken@0
   587
   Returns which channel was used to play the sound.
slouken@0
   588
*/
megastep@7
   589
int Mix_PlayChannelTimed(int which, Mix_Chunk *chunk, int loops, int ticks)
slouken@0
   590
{
slouken@0
   591
	int i;
slouken@0
   592
slouken@0
   593
	/* Don't play null pointers :-) */
slouken@0
   594
	if ( chunk == NULL ) {
slouken@0
   595
		return(-1);
slouken@0
   596
	}
slouken@0
   597
slouken@0
   598
	/* Lock the mixer while modifying the playing channels */
slouken@172
   599
	SDL_LockAudio();
slouken@0
   600
	{
slouken@0
   601
		/* If which is -1, play on the first free channel */
slouken@0
   602
		if ( which == -1 ) {
megastep@7
   603
			for ( i=reserved_channels; i<num_channels; ++i ) {
slouken@60
   604
				if ( mix_channel[i].playing <= 0 )
slouken@0
   605
					break;
slouken@0
   606
			}
megastep@7
   607
			if ( i == num_channels ) {
slouken@0
   608
				which = -1;
slouken@0
   609
			} else {
slouken@0
   610
				which = i;
slouken@0
   611
			}
slouken@0
   612
		}
slouken@0
   613
slouken@0
   614
		/* Queue up the audio data for this channel */
slouken@0
   615
		if ( which >= 0 ) {
slouken@158
   616
			Uint32 sdl_ticks = SDL_GetTicks();
slouken@157
   617
			if (Mix_Playing(which))
slouken@172
   618
				_Mix_channel_done_playing(which);
slouken@60
   619
			mix_channel[which].samples = chunk->abuf;
slouken@60
   620
			mix_channel[which].playing = chunk->alen;
slouken@60
   621
			mix_channel[which].looping = loops;
slouken@60
   622
			mix_channel[which].chunk = chunk;
slouken@60
   623
			mix_channel[which].paused = 0;
slouken@60
   624
			mix_channel[which].fading = MIX_NO_FADING;
slouken@60
   625
			mix_channel[which].start_time = sdl_ticks;
slouken@60
   626
			mix_channel[which].expire = (ticks>0) ? (sdl_ticks + ticks) : 0;
megastep@4
   627
		}
megastep@4
   628
	}
slouken@172
   629
	SDL_UnlockAudio();
megastep@4
   630
megastep@4
   631
	/* Return the channel on which the sound is being played */
megastep@4
   632
	return(which);
megastep@4
   633
}
megastep@4
   634
megastep@7
   635
/* Change the expiration delay for a channel */
megastep@7
   636
int Mix_ExpireChannel(int which, int ticks)
megastep@7
   637
{
megastep@7
   638
	int status = 0;
megastep@7
   639
megastep@7
   640
	if ( which == -1 ) {
megastep@7
   641
		int i;
megastep@7
   642
		for ( i=0; i < num_channels; ++ i ) {
megastep@7
   643
			status += Mix_ExpireChannel(i, ticks);
megastep@7
   644
		}
megastep@7
   645
	} else if ( which < num_channels ) {
slouken@172
   646
		SDL_LockAudio();
slouken@60
   647
		mix_channel[which].expire = (ticks>0) ? (SDL_GetTicks() + ticks) : 0;
slouken@172
   648
		SDL_UnlockAudio();
megastep@7
   649
		++ status;
megastep@7
   650
	}
megastep@7
   651
	return(status);
megastep@7
   652
}
megastep@7
   653
megastep@4
   654
/* Fade in a sound on a channel, over ms milliseconds */
megastep@7
   655
int Mix_FadeInChannelTimed(int which, Mix_Chunk *chunk, int loops, int ms, int ticks)
megastep@4
   656
{
megastep@4
   657
	int i;
megastep@4
   658
megastep@4
   659
	/* Don't play null pointers :-) */
megastep@4
   660
	if ( chunk == NULL ) {
megastep@4
   661
		return(-1);
megastep@4
   662
	}
megastep@4
   663
megastep@4
   664
	/* Lock the mixer while modifying the playing channels */
slouken@172
   665
	SDL_LockAudio();
megastep@4
   666
	{
megastep@4
   667
		/* If which is -1, play on the first free channel */
megastep@4
   668
		if ( which == -1 ) {
megastep@7
   669
			for ( i=reserved_channels; i<num_channels; ++i ) {
slouken@60
   670
				if ( mix_channel[i].playing <= 0 )
megastep@4
   671
					break;
megastep@4
   672
			}
megastep@7
   673
			if ( i == num_channels ) {
megastep@4
   674
				which = -1;
megastep@4
   675
			} else {
megastep@4
   676
				which = i;
megastep@4
   677
			}
megastep@4
   678
		}
megastep@4
   679
megastep@4
   680
		/* Queue up the audio data for this channel */
megastep@4
   681
		if ( which >= 0 ) {
slouken@158
   682
			Uint32 sdl_ticks = SDL_GetTicks();
slouken@157
   683
			if (Mix_Playing(which))
slouken@172
   684
				_Mix_channel_done_playing(which);
slouken@60
   685
			mix_channel[which].samples = chunk->abuf;
slouken@60
   686
			mix_channel[which].playing = chunk->alen;
slouken@60
   687
			mix_channel[which].looping = loops;
slouken@60
   688
			mix_channel[which].chunk = chunk;
slouken@60
   689
			mix_channel[which].paused = 0;
slouken@60
   690
			mix_channel[which].fading = MIX_FADING_IN;
slouken@60
   691
			mix_channel[which].fade_volume = mix_channel[which].volume;
slouken@60
   692
			mix_channel[which].volume = 0;
slouken@60
   693
			mix_channel[which].fade_length = (Uint32)ms;
slouken@60
   694
			mix_channel[which].start_time = mix_channel[which].ticks_fade = sdl_ticks;
slouken@60
   695
			mix_channel[which].expire = (ticks > 0) ? (sdl_ticks+ticks) : 0;
slouken@0
   696
		}
slouken@0
   697
	}
slouken@172
   698
	SDL_UnlockAudio();
slouken@0
   699
slouken@0
   700
	/* Return the channel on which the sound is being played */
slouken@0
   701
	return(which);
slouken@0
   702
}
slouken@0
   703
slouken@0
   704
/* Set volume of a particular channel */
slouken@0
   705
int Mix_Volume(int which, int volume)
slouken@0
   706
{
slouken@0
   707
	int i;
slouken@0
   708
	int prev_volume;
slouken@0
   709
slouken@0
   710
	if ( which == -1 ) {
slouken@0
   711
		prev_volume = 0;
megastep@7
   712
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   713
			prev_volume += Mix_Volume(i, volume);
slouken@0
   714
		}
megastep@7
   715
		prev_volume /= num_channels;
slouken@0
   716
	} else {
slouken@60
   717
		prev_volume = mix_channel[which].volume;
slouken@163
   718
		if ( volume >= 0 ) {
slouken@163
   719
			if ( volume > SDL_MIX_MAXVOLUME ) {
slouken@163
   720
				volume = SDL_MIX_MAXVOLUME;
slouken@163
   721
			}
slouken@163
   722
			mix_channel[which].volume = volume;
slouken@0
   723
		}
slouken@0
   724
	}
slouken@0
   725
	return(prev_volume);
slouken@0
   726
}
slouken@0
   727
/* Set volume of a particular chunk */
slouken@0
   728
int Mix_VolumeChunk(Mix_Chunk *chunk, int volume)
slouken@0
   729
{
slouken@0
   730
	int prev_volume;
slouken@0
   731
slouken@0
   732
	prev_volume = chunk->volume;
slouken@0
   733
	if ( volume >= 0 ) {
slouken@0
   734
		if ( volume > MIX_MAX_VOLUME ) {
slouken@0
   735
			volume = MIX_MAX_VOLUME;
slouken@0
   736
		}
slouken@0
   737
		chunk->volume = volume;
slouken@0
   738
	}
slouken@0
   739
	return(prev_volume);
slouken@0
   740
}
slouken@0
   741
slouken@0
   742
/* Halt playing of a particular channel */
slouken@0
   743
int Mix_HaltChannel(int which)
slouken@0
   744
{
slouken@0
   745
	int i;
slouken@0
   746
slouken@0
   747
	if ( which == -1 ) {
megastep@7
   748
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   749
			Mix_HaltChannel(i);
slouken@0
   750
		}
slouken@0
   751
	} else {
slouken@172
   752
		SDL_LockAudio();
slouken@113
   753
		if (mix_channel[which].playing) {
slouken@172
   754
			_Mix_channel_done_playing(which);
slouken@60
   755
		mix_channel[which].playing = 0;
slouken@113
   756
		}
slouken@60
   757
		mix_channel[which].expire = 0;
slouken@60
   758
		if(mix_channel[which].fading != MIX_NO_FADING) /* Restore volume */
slouken@60
   759
			mix_channel[which].volume = mix_channel[which].fade_volume;
slouken@60
   760
		mix_channel[which].fading = MIX_NO_FADING;
slouken@172
   761
		SDL_UnlockAudio();
slouken@0
   762
	}
slouken@0
   763
	return(0);
slouken@0
   764
}
slouken@0
   765
megastep@7
   766
/* Halt playing of a particular group of channels */
megastep@7
   767
int Mix_HaltGroup(int tag)
megastep@7
   768
{
megastep@7
   769
	int i;
megastep@7
   770
megastep@7
   771
	for ( i=0; i<num_channels; ++i ) {
slouken@60
   772
		if( mix_channel[i].tag == tag ) {
megastep@7
   773
			Mix_HaltChannel(i);
megastep@7
   774
		}
megastep@7
   775
	}
megastep@7
   776
	return(0);
megastep@7
   777
}
megastep@7
   778
megastep@4
   779
/* Fade out a channel and then stop it automatically */
megastep@4
   780
int Mix_FadeOutChannel(int which, int ms)
megastep@4
   781
{
megastep@4
   782
	int status;
megastep@4
   783
megastep@4
   784
	status = 0;
slouken@89
   785
	if ( audio_opened ) {
slouken@89
   786
		if ( which == -1 ) {
slouken@89
   787
			int i;
megastep@4
   788
slouken@89
   789
			for ( i=0; i<num_channels; ++i ) {
slouken@89
   790
				status += Mix_FadeOutChannel(i, ms);
slouken@89
   791
			}
slouken@89
   792
		} else {
slouken@172
   793
			SDL_LockAudio();
slouken@89
   794
			if ( mix_channel[which].playing && 
slouken@89
   795
			    (mix_channel[which].volume > 0) &&
slouken@89
   796
			    (mix_channel[which].fading != MIX_FADING_OUT) ) {
slouken@89
   797
slouken@89
   798
				mix_channel[which].fading = MIX_FADING_OUT;
slouken@89
   799
				mix_channel[which].fade_volume = mix_channel[which].volume;
slouken@89
   800
				mix_channel[which].fade_length = ms;
slouken@89
   801
				mix_channel[which].ticks_fade = SDL_GetTicks();
slouken@89
   802
				++status;
slouken@89
   803
			}
slouken@172
   804
			SDL_UnlockAudio();
megastep@4
   805
		}
megastep@4
   806
	}
megastep@4
   807
	return(status);
megastep@4
   808
}
megastep@4
   809
megastep@7
   810
/* Halt playing of a particular group of channels */
megastep@7
   811
int Mix_FadeOutGroup(int tag, int ms)
megastep@7
   812
{
megastep@7
   813
	int i;
megastep@7
   814
	int status = 0;
megastep@7
   815
	for ( i=0; i<num_channels; ++i ) {
slouken@60
   816
		if( mix_channel[i].tag == tag ) {
megastep@7
   817
			status += Mix_FadeOutChannel(i,ms);
megastep@7
   818
		}
megastep@7
   819
	}
megastep@7
   820
	return(status);
megastep@7
   821
}
megastep@7
   822
megastep@4
   823
Mix_Fading Mix_FadingChannel(int which)
megastep@4
   824
{
slouken@60
   825
	return mix_channel[which].fading;
megastep@4
   826
}
megastep@4
   827
slouken@0
   828
/* Check the status of a specific channel.
slouken@113
   829
   If the specified mix_channel is -1, check all mix channels.
slouken@0
   830
*/
slouken@0
   831
int Mix_Playing(int which)
slouken@0
   832
{
slouken@0
   833
	int status;
slouken@0
   834
slouken@0
   835
	status = 0;
slouken@0
   836
	if ( which == -1 ) {
slouken@0
   837
		int i;
slouken@0
   838
megastep@7
   839
		for ( i=0; i<num_channels; ++i ) {
slouken@113
   840
			if ((mix_channel[i].playing > 0) ||
slouken@113
   841
				(mix_channel[i].looping > 0))
slouken@113
   842
			{
slouken@0
   843
				++status;
slouken@0
   844
			}
slouken@0
   845
		}
slouken@0
   846
	} else {
slouken@113
   847
		if ((mix_channel[which].playing > 0) ||
slouken@113
   848
			(mix_channel[which].looping > 0))
slouken@113
   849
		{
slouken@0
   850
			++status;
slouken@0
   851
		}
slouken@0
   852
	}
slouken@0
   853
	return(status);
slouken@0
   854
}
slouken@0
   855
slouken@92
   856
/* rcg06072001 Get the chunk associated with a channel. */
slouken@92
   857
Mix_Chunk *Mix_GetChunk(int channel)
slouken@92
   858
{
slouken@92
   859
	Mix_Chunk *retval = NULL;
slouken@92
   860
slouken@92
   861
	if ((channel >= 0) && (channel < num_channels)) {
slouken@92
   862
		retval = mix_channel[channel].chunk;
slouken@92
   863
	}
slouken@92
   864
slouken@92
   865
	return(retval);
slouken@92
   866
}
slouken@92
   867
slouken@0
   868
/* Close the mixer, halting all playing audio */
slouken@0
   869
void Mix_CloseAudio(void)
slouken@0
   870
{
slouken@113
   871
	int i;
slouken@113
   872
slouken@0
   873
	if ( audio_opened ) {
slouken@0
   874
		if ( audio_opened == 1 ) {
slouken@113
   875
			for (i = 0; i < num_channels; i++) {
slouken@113
   876
				Mix_UnregisterAllEffects(i);
slouken@113
   877
			}
slouken@113
   878
			Mix_UnregisterAllEffects(MIX_CHANNEL_POST);
slouken@0
   879
			close_music();
slouken@0
   880
			Mix_HaltChannel(-1);
slouken@0
   881
			SDL_CloseAudio();
slouken@60
   882
			free(mix_channel);
slouken@60
   883
			mix_channel = NULL;
slouken@0
   884
		}
slouken@0
   885
		--audio_opened;
slouken@0
   886
	}
slouken@0
   887
}
slouken@0
   888
slouken@0
   889
/* Pause a particular channel (or all) */
slouken@0
   890
void Mix_Pause(int which)
slouken@0
   891
{
megastep@8
   892
	Uint32 sdl_ticks = SDL_GetTicks();
slouken@0
   893
	if ( which == -1 ) {
slouken@0
   894
		int i;
slouken@0
   895
megastep@7
   896
		for ( i=0; i<num_channels; ++i ) {
slouken@60
   897
			if ( mix_channel[i].playing > 0 ) {
slouken@60
   898
				mix_channel[i].paused = sdl_ticks;
slouken@0
   899
			}
slouken@0
   900
		}
slouken@0
   901
	} else {
slouken@60
   902
		if ( mix_channel[which].playing > 0 ) {
slouken@60
   903
			mix_channel[which].paused = sdl_ticks;
slouken@0
   904
		}
slouken@0
   905
	}
slouken@0
   906
}
slouken@0
   907
slouken@0
   908
/* Resume a paused channel */
slouken@0
   909
void Mix_Resume(int which)
slouken@0
   910
{
megastep@8
   911
	Uint32 sdl_ticks = SDL_GetTicks();
slouken@172
   912
slouken@172
   913
	SDL_LockAudio();
slouken@0
   914
	if ( which == -1 ) {
slouken@0
   915
		int i;
slouken@0
   916
megastep@7
   917
		for ( i=0; i<num_channels; ++i ) {
slouken@60
   918
			if ( mix_channel[i].playing > 0 ) {
slouken@60
   919
				if(mix_channel[i].expire > 0)
slouken@60
   920
					mix_channel[i].expire += sdl_ticks - mix_channel[i].paused;
slouken@60
   921
				mix_channel[i].paused = 0;
slouken@0
   922
			}
slouken@0
   923
		}
slouken@0
   924
	} else {
slouken@60
   925
		if ( mix_channel[which].playing > 0 ) {
slouken@60
   926
			if(mix_channel[which].expire > 0)
slouken@60
   927
				mix_channel[which].expire += sdl_ticks - mix_channel[which].paused;
slouken@60
   928
			mix_channel[which].paused = 0;
slouken@0
   929
		}
slouken@0
   930
	}
slouken@172
   931
	SDL_UnlockAudio();
slouken@0
   932
}
megastep@7
   933
megastep@13
   934
int Mix_Paused(int which)
megastep@13
   935
{
megastep@14
   936
	if ( which > num_channels )
megastep@13
   937
		return(0);
megastep@14
   938
	if ( which < 0 ) {
megastep@14
   939
		int status = 0;
megastep@14
   940
		int i;
megastep@14
   941
		for( i=0; i < num_channels; ++i ) {
slouken@60
   942
			if ( mix_channel[i].paused ) {
megastep@14
   943
				++ status;
megastep@14
   944
			}
megastep@14
   945
		}
megastep@14
   946
		return(status);
megastep@14
   947
	} else {
slouken@60
   948
		return(mix_channel[which].paused != 0);
megastep@14
   949
	}
megastep@13
   950
}
megastep@13
   951
megastep@7
   952
/* Change the group of a channel */
megastep@7
   953
int Mix_GroupChannel(int which, int tag)
megastep@7
   954
{
megastep@7
   955
	if ( which < 0 || which > num_channels )
megastep@7
   956
		return(0);
megastep@7
   957
slouken@172
   958
	SDL_LockAudio();
slouken@60
   959
	mix_channel[which].tag = tag;
slouken@172
   960
	SDL_UnlockAudio();
megastep@7
   961
	return(1);
megastep@7
   962
}
megastep@7
   963
megastep@7
   964
/* Assign several consecutive channels to a group */
megastep@7
   965
int Mix_GroupChannels(int from, int to, int tag)
megastep@7
   966
{
megastep@7
   967
	int status = 0;
megastep@7
   968
	for( ; from <= to; ++ from ) {
megastep@7
   969
		status += Mix_GroupChannel(from, tag);
megastep@7
   970
	}
megastep@7
   971
	return(status);
megastep@7
   972
}
megastep@7
   973
megastep@7
   974
/* Finds the first available channel in a group of channels */
megastep@7
   975
int Mix_GroupAvailable(int tag)
megastep@7
   976
{
megastep@7
   977
	int i;
megastep@7
   978
	for( i=0; i < num_channels; i ++ ) {
slouken@60
   979
		if ( ((tag == -1) || (tag == mix_channel[i].tag)) &&
slouken@60
   980
		                    (mix_channel[i].playing <= 0) )
megastep@7
   981
			return i;
megastep@7
   982
	}
megastep@7
   983
	return(-1);
megastep@7
   984
}
megastep@7
   985
megastep@7
   986
int Mix_GroupCount(int tag)
megastep@7
   987
{
megastep@7
   988
	int count = 0;
megastep@7
   989
	int i;
megastep@7
   990
	for( i=0; i < num_channels; i ++ ) {
slouken@60
   991
		if ( mix_channel[i].tag==tag || tag==-1 )
megastep@7
   992
			++ count;
megastep@7
   993
	}
megastep@7
   994
	return(count);
megastep@7
   995
}
megastep@8
   996
megastep@8
   997
/* Finds the "oldest" sample playing in a group of channels */
megastep@8
   998
int Mix_GroupOldest(int tag)
megastep@8
   999
{
megastep@8
  1000
	int chan = -1;
megastep@8
  1001
	Uint32 mintime = SDL_GetTicks();
megastep@8
  1002
	int i;
megastep@8
  1003
	for( i=0; i < num_channels; i ++ ) {
slouken@60
  1004
		if ( (mix_channel[i].tag==tag || tag==-1) && mix_channel[i].playing > 0
slouken@60
  1005
			 && mix_channel[i].start_time <= mintime ) {
slouken@60
  1006
			mintime = mix_channel[i].start_time;
megastep@8
  1007
			chan = i;
megastep@8
  1008
		}
megastep@8
  1009
	}
megastep@8
  1010
	return(chan);
megastep@8
  1011
}
megastep@8
  1012
megastep@8
  1013
/* Finds the "most recent" (i.e. last) sample playing in a group of channels */
megastep@8
  1014
int Mix_GroupNewer(int tag)
megastep@8
  1015
{
megastep@8
  1016
	int chan = -1;
megastep@8
  1017
	Uint32 maxtime = 0;
megastep@8
  1018
	int i;
megastep@8
  1019
	for( i=0; i < num_channels; i ++ ) {
slouken@60
  1020
		if ( (mix_channel[i].tag==tag || tag==-1) && mix_channel[i].playing > 0
slouken@60
  1021
			 && mix_channel[i].start_time >= maxtime ) {
slouken@60
  1022
			maxtime = mix_channel[i].start_time;
megastep@8
  1023
			chan = i;
megastep@8
  1024
		}
megastep@8
  1025
	}
megastep@8
  1026
	return(chan);
megastep@8
  1027
}
slouken@113
  1028
slouken@113
  1029
slouken@113
  1030
slouken@113
  1031
/*
slouken@113
  1032
 * rcg06122001 The special effects exportable API.
slouken@113
  1033
 *  Please see effect_*.c for internally-implemented effects, such
slouken@113
  1034
 *  as Mix_SetPanning().
slouken@113
  1035
 */
slouken@113
  1036
slouken@164
  1037
/* MAKE SURE you hold the audio lock (SDL_LockAudio()) before calling this! */
slouken@113
  1038
static int _Mix_register_effect(effect_info **e, Mix_EffectFunc_t f,
slouken@164
  1039
				Mix_EffectDone_t d, void *arg)
slouken@113
  1040
{
slouken@113
  1041
	effect_info *new_e = malloc(sizeof (effect_info));
slouken@113
  1042
slouken@113
  1043
	if (!e) {
slouken@113
  1044
		Mix_SetError("Internal error");
slouken@113
  1045
		return(0);
slouken@113
  1046
	}
slouken@113
  1047
slouken@113
  1048
	if (f == NULL) {
slouken@113
  1049
		Mix_SetError("NULL effect callback");
slouken@113
  1050
		return(0);
slouken@113
  1051
	}
slouken@113
  1052
slouken@113
  1053
	if (new_e == NULL) {
slouken@113
  1054
		Mix_SetError("Out of memory");
slouken@113
  1055
		return(0);
slouken@113
  1056
	}
slouken@113
  1057
slouken@113
  1058
	new_e->callback = f;
slouken@113
  1059
	new_e->done_callback = d;
slouken@113
  1060
	new_e->udata = arg;
slouken@113
  1061
	new_e->next = NULL;
slouken@113
  1062
slouken@113
  1063
	/* add new effect to end of linked list... */
slouken@113
  1064
	if (*e == NULL) {
slouken@113
  1065
		*e = new_e;
slouken@113
  1066
	} else {
slouken@113
  1067
		effect_info *cur = *e;
slouken@113
  1068
		while (1) {
slouken@113
  1069
			if (cur->next == NULL) {
slouken@113
  1070
				cur->next = new_e;
slouken@113
  1071
				break;
slouken@113
  1072
			}
slouken@113
  1073
			cur = cur->next;
slouken@113
  1074
		}
slouken@113
  1075
	}
slouken@113
  1076
slouken@113
  1077
	return(1);
slouken@113
  1078
}
slouken@113
  1079
slouken@113
  1080
slouken@164
  1081
/* MAKE SURE you hold the audio lock (SDL_LockAudio()) before calling this! */
slouken@113
  1082
static int _Mix_remove_effect(int channel, effect_info **e, Mix_EffectFunc_t f)
slouken@113
  1083
{
slouken@113
  1084
	effect_info *cur;
slouken@113
  1085
	effect_info *prev = NULL;
slouken@113
  1086
	effect_info *next = NULL;
slouken@113
  1087
slouken@113
  1088
	if (!e) {
slouken@113
  1089
		Mix_SetError("Internal error");
slouken@113
  1090
		return(0);
slouken@113
  1091
	}
slouken@113
  1092
slouken@113
  1093
	for (cur = *e; cur != NULL; cur = cur->next) {
slouken@113
  1094
		if (cur->callback == f) {
slouken@113
  1095
			next = cur->next;
slouken@113
  1096
			if (cur->done_callback != NULL) {
slouken@113
  1097
				cur->done_callback(channel, cur->udata);
slouken@113
  1098
			}
slouken@113
  1099
			free(cur);
slouken@113
  1100
slouken@113
  1101
			if (prev == NULL) {   /* removing first item of list? */
slouken@113
  1102
				*e = next;
slouken@113
  1103
			} else {
slouken@113
  1104
				prev->next = next;
slouken@113
  1105
			}
slouken@113
  1106
			return(1);
slouken@113
  1107
		}
slouken@113
  1108
		prev = cur;
slouken@113
  1109
	}
slouken@113
  1110
slouken@113
  1111
	Mix_SetError("No such effect registered");
slouken@113
  1112
	return(0);
slouken@113
  1113
}
slouken@113
  1114
slouken@113
  1115
slouken@164
  1116
/* MAKE SURE you hold the audio lock (SDL_LockAudio()) before calling this! */
slouken@113
  1117
static int _Mix_remove_all_effects(int channel, effect_info **e)
slouken@113
  1118
{
slouken@113
  1119
	effect_info *cur;
slouken@113
  1120
	effect_info *next;
slouken@113
  1121
slouken@113
  1122
	if (!e) {
slouken@113
  1123
		Mix_SetError("Internal error");
slouken@113
  1124
		return(0);
slouken@113
  1125
	}
slouken@113
  1126
slouken@113
  1127
	for (cur = *e; cur != NULL; cur = next) {
slouken@113
  1128
		next = cur->next;
slouken@113
  1129
		if (cur->done_callback != NULL) {
slouken@113
  1130
			cur->done_callback(channel, cur->udata);
slouken@113
  1131
		}
slouken@113
  1132
		free(cur);
slouken@113
  1133
	}
slouken@113
  1134
	*e = NULL;
slouken@113
  1135
slouken@113
  1136
	return(1);
slouken@113
  1137
}
slouken@113
  1138
slouken@113
  1139
slouken@113
  1140
int Mix_RegisterEffect(int channel, Mix_EffectFunc_t f,
slouken@164
  1141
			Mix_EffectDone_t d, void *arg)
slouken@113
  1142
{
slouken@113
  1143
	effect_info **e = NULL;
slouken@164
  1144
	int retval;
slouken@113
  1145
slouken@113
  1146
	if (channel == MIX_CHANNEL_POST) {
slouken@113
  1147
		e = &posteffects;
slouken@113
  1148
	} else {
slouken@113
  1149
		if ((channel < 0) || (channel >= num_channels)) {
slouken@113
  1150
			Mix_SetError("Invalid channel number");
slouken@113
  1151
			return(0);
slouken@113
  1152
		}
slouken@113
  1153
		e = &mix_channel[channel].effects;
slouken@113
  1154
	}
slouken@113
  1155
slouken@164
  1156
	SDL_LockAudio();
slouken@164
  1157
	retval = _Mix_register_effect(e, f, d, arg);
slouken@164
  1158
	SDL_UnlockAudio();
slouken@164
  1159
	return(retval);
slouken@113
  1160
}
slouken@113
  1161
slouken@113
  1162
slouken@113
  1163
int Mix_UnregisterEffect(int channel, Mix_EffectFunc_t f)
slouken@113
  1164
{
slouken@113
  1165
	effect_info **e = NULL;
slouken@164
  1166
	int retval;
slouken@113
  1167
slouken@113
  1168
	if (channel == MIX_CHANNEL_POST) {
slouken@113
  1169
		e = &posteffects;
slouken@113
  1170
	} else {
slouken@113
  1171
		if ((channel < 0) || (channel >= num_channels)) {
slouken@113
  1172
			Mix_SetError("Invalid channel number");
slouken@113
  1173
			return(0);
slouken@113
  1174
		}
slouken@113
  1175
		e = &mix_channel[channel].effects;
slouken@113
  1176
	}
slouken@113
  1177
slouken@164
  1178
	SDL_LockAudio();
slouken@164
  1179
	retval = _Mix_remove_effect(channel, e, f);
slouken@164
  1180
	SDL_UnlockAudio();
slouken@164
  1181
	return(retval);
slouken@164
  1182
}
slouken@164
  1183
slouken@164
  1184
slouken@164
  1185
int Mix_UnregisterAllEffects(int channel)
slouken@164
  1186
{
slouken@164
  1187
	effect_info **e = NULL;
slouken@164
  1188
	int retval;
slouken@164
  1189
slouken@164
  1190
	if (channel == MIX_CHANNEL_POST) {
slouken@164
  1191
		e = &posteffects;
slouken@164
  1192
	} else {
slouken@164
  1193
		if ((channel < 0) || (channel >= num_channels)) {
slouken@164
  1194
			Mix_SetError("Invalid channel number");
slouken@164
  1195
			return(0);
slouken@164
  1196
		}
slouken@164
  1197
		e = &mix_channel[channel].effects;
slouken@164
  1198
	}
slouken@164
  1199
slouken@164
  1200
	SDL_LockAudio();
slouken@164
  1201
	retval = _Mix_remove_all_effects(channel, e);
slouken@164
  1202
	SDL_UnlockAudio();
slouken@164
  1203
	return(retval);
slouken@113
  1204
}
slouken@113
  1205
slouken@113
  1206
/* end of mixer.c ... */
slouken@113
  1207