mixer.c
author Sam Lantinga <slouken@libsdl.org>
Sun, 19 May 2002 20:50:35 +0000
changeset 178 de35197ea52a
parent 174 f9648fd517de
child 183 6dc1558848ee
permissions -rw-r--r--
Added some error messages for playchannel
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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;
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	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@174
   503
/* Load raw audio data of the mixer format from a memory buffer */
slouken@174
   504
Mix_Chunk *Mix_QuickLoad_RAW(Uint8 *mem, Uint32 len)
slouken@174
   505
{
slouken@174
   506
	Mix_Chunk *chunk;
slouken@174
   507
slouken@174
   508
	/* Make sure audio has been opened */
slouken@174
   509
	if ( ! audio_opened ) {
slouken@174
   510
		SDL_SetError("Audio device hasn't been opened");
slouken@174
   511
		return(NULL);
slouken@174
   512
	}
slouken@174
   513
slouken@174
   514
	/* Allocate the chunk memory */
slouken@174
   515
	chunk = (Mix_Chunk *)malloc(sizeof(Mix_Chunk));
slouken@174
   516
	if ( chunk == NULL ) {
slouken@174
   517
		SDL_SetError("Out of memory");
slouken@174
   518
		return(NULL);
slouken@174
   519
	}
slouken@174
   520
slouken@174
   521
	/* Essentially just point at the audio data (no error checking - fast) */
slouken@174
   522
	chunk->allocated = 0;
slouken@174
   523
	chunk->alen = len;
slouken@174
   524
	chunk->abuf = mem;
slouken@174
   525
	chunk->volume = MIX_MAX_VOLUME;
slouken@174
   526
slouken@174
   527
	return(chunk);
slouken@174
   528
}
slouken@174
   529
slouken@0
   530
/* Free an audio chunk previously loaded */
slouken@0
   531
void Mix_FreeChunk(Mix_Chunk *chunk)
slouken@0
   532
{
slouken@0
   533
	int i;
slouken@0
   534
slouken@0
   535
	/* Caution -- if the chunk is playing, the mixer will crash */
slouken@0
   536
	if ( chunk ) {
slouken@0
   537
		/* Guarantee that this chunk isn't playing */
slouken@172
   538
		SDL_LockAudio();
slouken@60
   539
		if ( mix_channel ) {
slouken@60
   540
			for ( i=0; i<num_channels; ++i ) {
slouken@60
   541
				if ( chunk == mix_channel[i].chunk ) {
slouken@60
   542
					mix_channel[i].playing = 0;
slouken@60
   543
				}
slouken@0
   544
			}
slouken@0
   545
		}
slouken@172
   546
		SDL_UnlockAudio();
slouken@0
   547
		/* Actually free the chunk */
slouken@1
   548
		if ( chunk->allocated ) {
slouken@1
   549
			free(chunk->abuf);
slouken@1
   550
		}
slouken@0
   551
		free(chunk);
slouken@0
   552
	}
slouken@0
   553
}
slouken@0
   554
slouken@26
   555
/* Set a function that is called after all mixing is performed.
slouken@26
   556
   This can be used to provide real-time visual display of the audio stream
slouken@26
   557
   or add a custom mixer filter for the stream data.
slouken@26
   558
*/
slouken@26
   559
void Mix_SetPostMix(void (*mix_func)
slouken@26
   560
                    (void *udata, Uint8 *stream, int len), void *arg)
slouken@26
   561
{
slouken@26
   562
	SDL_LockAudio();
slouken@26
   563
	mix_postmix_data = arg;
slouken@26
   564
	mix_postmix = mix_func;
slouken@26
   565
	SDL_UnlockAudio();
slouken@26
   566
}
slouken@26
   567
slouken@0
   568
/* Add your own music player or mixer function.
slouken@0
   569
   If 'mix_func' is NULL, the default music player is re-enabled.
slouken@0
   570
 */
slouken@0
   571
void Mix_HookMusic(void (*mix_func)(void *udata, Uint8 *stream, int len),
slouken@0
   572
                                                                void *arg)
slouken@0
   573
{
slouken@0
   574
	SDL_LockAudio();
slouken@0
   575
	if ( mix_func != NULL ) {
slouken@0
   576
		music_data = arg;
slouken@0
   577
		mix_music = mix_func;
slouken@0
   578
	} else {
slouken@0
   579
		music_data = NULL;
slouken@0
   580
		mix_music = music_mixer;
slouken@0
   581
	}
slouken@0
   582
	SDL_UnlockAudio();
slouken@0
   583
}
slouken@0
   584
slouken@0
   585
void *Mix_GetMusicHookData(void)
slouken@0
   586
{
slouken@0
   587
	return(music_data);
slouken@0
   588
}
slouken@0
   589
slouken@92
   590
void Mix_ChannelFinished(void (*channel_finished)(int channel))
slouken@92
   591
{
slouken@172
   592
	SDL_LockAudio();
slouken@172
   593
	channel_done_callback = channel_finished;
slouken@172
   594
	SDL_UnlockAudio();
slouken@92
   595
}
slouken@92
   596
slouken@92
   597
slouken@0
   598
/* Reserve the first channels (0 -> n-1) for the application, i.e. don't allocate
slouken@0
   599
   them dynamically to the next sample if requested with a -1 value below.
slouken@0
   600
   Returns the number of reserved channels.
slouken@0
   601
 */
slouken@0
   602
int Mix_ReserveChannels(int num)
slouken@0
   603
{
megastep@7
   604
	if (num > num_channels)
megastep@7
   605
		num = num_channels;
slouken@0
   606
	reserved_channels = num;
slouken@0
   607
	return num;
slouken@0
   608
}
slouken@0
   609
slouken@0
   610
/* Play an audio chunk on a specific channel.
slouken@0
   611
   If the specified channel is -1, play on the first free channel.
megastep@7
   612
   'ticks' is the number of milliseconds at most to play the sample, or -1
megastep@7
   613
   if there is no limit.
slouken@0
   614
   Returns which channel was used to play the sound.
slouken@0
   615
*/
megastep@7
   616
int Mix_PlayChannelTimed(int which, Mix_Chunk *chunk, int loops, int ticks)
slouken@0
   617
{
slouken@0
   618
	int i;
slouken@0
   619
slouken@0
   620
	/* Don't play null pointers :-) */
slouken@0
   621
	if ( chunk == NULL ) {
slouken@178
   622
		Mix_SetError("Tried to play a NULL chunk");
slouken@0
   623
		return(-1);
slouken@0
   624
	}
slouken@0
   625
slouken@0
   626
	/* Lock the mixer while modifying the playing channels */
slouken@172
   627
	SDL_LockAudio();
slouken@0
   628
	{
slouken@0
   629
		/* If which is -1, play on the first free channel */
slouken@0
   630
		if ( which == -1 ) {
megastep@7
   631
			for ( i=reserved_channels; i<num_channels; ++i ) {
slouken@60
   632
				if ( mix_channel[i].playing <= 0 )
slouken@0
   633
					break;
slouken@0
   634
			}
megastep@7
   635
			if ( i == num_channels ) {
slouken@178
   636
				Mix_SetError("No free channels available");
slouken@0
   637
				which = -1;
slouken@0
   638
			} else {
slouken@0
   639
				which = i;
slouken@0
   640
			}
slouken@0
   641
		}
slouken@0
   642
slouken@0
   643
		/* Queue up the audio data for this channel */
slouken@0
   644
		if ( which >= 0 ) {
slouken@158
   645
			Uint32 sdl_ticks = SDL_GetTicks();
slouken@157
   646
			if (Mix_Playing(which))
slouken@172
   647
				_Mix_channel_done_playing(which);
slouken@60
   648
			mix_channel[which].samples = chunk->abuf;
slouken@60
   649
			mix_channel[which].playing = chunk->alen;
slouken@60
   650
			mix_channel[which].looping = loops;
slouken@60
   651
			mix_channel[which].chunk = chunk;
slouken@60
   652
			mix_channel[which].paused = 0;
slouken@60
   653
			mix_channel[which].fading = MIX_NO_FADING;
slouken@60
   654
			mix_channel[which].start_time = sdl_ticks;
slouken@60
   655
			mix_channel[which].expire = (ticks>0) ? (sdl_ticks + ticks) : 0;
megastep@4
   656
		}
megastep@4
   657
	}
slouken@172
   658
	SDL_UnlockAudio();
megastep@4
   659
megastep@4
   660
	/* Return the channel on which the sound is being played */
megastep@4
   661
	return(which);
megastep@4
   662
}
megastep@4
   663
megastep@7
   664
/* Change the expiration delay for a channel */
megastep@7
   665
int Mix_ExpireChannel(int which, int ticks)
megastep@7
   666
{
megastep@7
   667
	int status = 0;
megastep@7
   668
megastep@7
   669
	if ( which == -1 ) {
megastep@7
   670
		int i;
megastep@7
   671
		for ( i=0; i < num_channels; ++ i ) {
megastep@7
   672
			status += Mix_ExpireChannel(i, ticks);
megastep@7
   673
		}
megastep@7
   674
	} else if ( which < num_channels ) {
slouken@172
   675
		SDL_LockAudio();
slouken@60
   676
		mix_channel[which].expire = (ticks>0) ? (SDL_GetTicks() + ticks) : 0;
slouken@172
   677
		SDL_UnlockAudio();
megastep@7
   678
		++ status;
megastep@7
   679
	}
megastep@7
   680
	return(status);
megastep@7
   681
}
megastep@7
   682
megastep@4
   683
/* Fade in a sound on a channel, over ms milliseconds */
megastep@7
   684
int Mix_FadeInChannelTimed(int which, Mix_Chunk *chunk, int loops, int ms, int ticks)
megastep@4
   685
{
megastep@4
   686
	int i;
megastep@4
   687
megastep@4
   688
	/* Don't play null pointers :-) */
megastep@4
   689
	if ( chunk == NULL ) {
megastep@4
   690
		return(-1);
megastep@4
   691
	}
megastep@4
   692
megastep@4
   693
	/* Lock the mixer while modifying the playing channels */
slouken@172
   694
	SDL_LockAudio();
megastep@4
   695
	{
megastep@4
   696
		/* If which is -1, play on the first free channel */
megastep@4
   697
		if ( which == -1 ) {
megastep@7
   698
			for ( i=reserved_channels; i<num_channels; ++i ) {
slouken@60
   699
				if ( mix_channel[i].playing <= 0 )
megastep@4
   700
					break;
megastep@4
   701
			}
megastep@7
   702
			if ( i == num_channels ) {
megastep@4
   703
				which = -1;
megastep@4
   704
			} else {
megastep@4
   705
				which = i;
megastep@4
   706
			}
megastep@4
   707
		}
megastep@4
   708
megastep@4
   709
		/* Queue up the audio data for this channel */
megastep@4
   710
		if ( which >= 0 ) {
slouken@158
   711
			Uint32 sdl_ticks = SDL_GetTicks();
slouken@157
   712
			if (Mix_Playing(which))
slouken@172
   713
				_Mix_channel_done_playing(which);
slouken@60
   714
			mix_channel[which].samples = chunk->abuf;
slouken@60
   715
			mix_channel[which].playing = chunk->alen;
slouken@60
   716
			mix_channel[which].looping = loops;
slouken@60
   717
			mix_channel[which].chunk = chunk;
slouken@60
   718
			mix_channel[which].paused = 0;
slouken@60
   719
			mix_channel[which].fading = MIX_FADING_IN;
slouken@60
   720
			mix_channel[which].fade_volume = mix_channel[which].volume;
slouken@60
   721
			mix_channel[which].volume = 0;
slouken@60
   722
			mix_channel[which].fade_length = (Uint32)ms;
slouken@60
   723
			mix_channel[which].start_time = mix_channel[which].ticks_fade = sdl_ticks;
slouken@60
   724
			mix_channel[which].expire = (ticks > 0) ? (sdl_ticks+ticks) : 0;
slouken@0
   725
		}
slouken@0
   726
	}
slouken@172
   727
	SDL_UnlockAudio();
slouken@0
   728
slouken@0
   729
	/* Return the channel on which the sound is being played */
slouken@0
   730
	return(which);
slouken@0
   731
}
slouken@0
   732
slouken@0
   733
/* Set volume of a particular channel */
slouken@0
   734
int Mix_Volume(int which, int volume)
slouken@0
   735
{
slouken@0
   736
	int i;
slouken@0
   737
	int prev_volume;
slouken@0
   738
slouken@0
   739
	if ( which == -1 ) {
slouken@0
   740
		prev_volume = 0;
megastep@7
   741
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   742
			prev_volume += Mix_Volume(i, volume);
slouken@0
   743
		}
megastep@7
   744
		prev_volume /= num_channels;
slouken@0
   745
	} else {
slouken@60
   746
		prev_volume = mix_channel[which].volume;
slouken@163
   747
		if ( volume >= 0 ) {
slouken@163
   748
			if ( volume > SDL_MIX_MAXVOLUME ) {
slouken@163
   749
				volume = SDL_MIX_MAXVOLUME;
slouken@163
   750
			}
slouken@163
   751
			mix_channel[which].volume = volume;
slouken@0
   752
		}
slouken@0
   753
	}
slouken@0
   754
	return(prev_volume);
slouken@0
   755
}
slouken@0
   756
/* Set volume of a particular chunk */
slouken@0
   757
int Mix_VolumeChunk(Mix_Chunk *chunk, int volume)
slouken@0
   758
{
slouken@0
   759
	int prev_volume;
slouken@0
   760
slouken@0
   761
	prev_volume = chunk->volume;
slouken@0
   762
	if ( volume >= 0 ) {
slouken@0
   763
		if ( volume > MIX_MAX_VOLUME ) {
slouken@0
   764
			volume = MIX_MAX_VOLUME;
slouken@0
   765
		}
slouken@0
   766
		chunk->volume = volume;
slouken@0
   767
	}
slouken@0
   768
	return(prev_volume);
slouken@0
   769
}
slouken@0
   770
slouken@0
   771
/* Halt playing of a particular channel */
slouken@0
   772
int Mix_HaltChannel(int which)
slouken@0
   773
{
slouken@0
   774
	int i;
slouken@0
   775
slouken@0
   776
	if ( which == -1 ) {
megastep@7
   777
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   778
			Mix_HaltChannel(i);
slouken@0
   779
		}
slouken@0
   780
	} else {
slouken@172
   781
		SDL_LockAudio();
slouken@113
   782
		if (mix_channel[which].playing) {
slouken@172
   783
			_Mix_channel_done_playing(which);
slouken@60
   784
		mix_channel[which].playing = 0;
slouken@113
   785
		}
slouken@60
   786
		mix_channel[which].expire = 0;
slouken@60
   787
		if(mix_channel[which].fading != MIX_NO_FADING) /* Restore volume */
slouken@60
   788
			mix_channel[which].volume = mix_channel[which].fade_volume;
slouken@60
   789
		mix_channel[which].fading = MIX_NO_FADING;
slouken@172
   790
		SDL_UnlockAudio();
slouken@0
   791
	}
slouken@0
   792
	return(0);
slouken@0
   793
}
slouken@0
   794
megastep@7
   795
/* Halt playing of a particular group of channels */
megastep@7
   796
int Mix_HaltGroup(int tag)
megastep@7
   797
{
megastep@7
   798
	int i;
megastep@7
   799
megastep@7
   800
	for ( i=0; i<num_channels; ++i ) {
slouken@60
   801
		if( mix_channel[i].tag == tag ) {
megastep@7
   802
			Mix_HaltChannel(i);
megastep@7
   803
		}
megastep@7
   804
	}
megastep@7
   805
	return(0);
megastep@7
   806
}
megastep@7
   807
megastep@4
   808
/* Fade out a channel and then stop it automatically */
megastep@4
   809
int Mix_FadeOutChannel(int which, int ms)
megastep@4
   810
{
megastep@4
   811
	int status;
megastep@4
   812
megastep@4
   813
	status = 0;
slouken@89
   814
	if ( audio_opened ) {
slouken@89
   815
		if ( which == -1 ) {
slouken@89
   816
			int i;
megastep@4
   817
slouken@89
   818
			for ( i=0; i<num_channels; ++i ) {
slouken@89
   819
				status += Mix_FadeOutChannel(i, ms);
slouken@89
   820
			}
slouken@89
   821
		} else {
slouken@172
   822
			SDL_LockAudio();
slouken@89
   823
			if ( mix_channel[which].playing && 
slouken@89
   824
			    (mix_channel[which].volume > 0) &&
slouken@89
   825
			    (mix_channel[which].fading != MIX_FADING_OUT) ) {
slouken@89
   826
slouken@89
   827
				mix_channel[which].fading = MIX_FADING_OUT;
slouken@89
   828
				mix_channel[which].fade_volume = mix_channel[which].volume;
slouken@89
   829
				mix_channel[which].fade_length = ms;
slouken@89
   830
				mix_channel[which].ticks_fade = SDL_GetTicks();
slouken@89
   831
				++status;
slouken@89
   832
			}
slouken@172
   833
			SDL_UnlockAudio();
megastep@4
   834
		}
megastep@4
   835
	}
megastep@4
   836
	return(status);
megastep@4
   837
}
megastep@4
   838
megastep@7
   839
/* Halt playing of a particular group of channels */
megastep@7
   840
int Mix_FadeOutGroup(int tag, int ms)
megastep@7
   841
{
megastep@7
   842
	int i;
megastep@7
   843
	int status = 0;
megastep@7
   844
	for ( i=0; i<num_channels; ++i ) {
slouken@60
   845
		if( mix_channel[i].tag == tag ) {
megastep@7
   846
			status += Mix_FadeOutChannel(i,ms);
megastep@7
   847
		}
megastep@7
   848
	}
megastep@7
   849
	return(status);
megastep@7
   850
}
megastep@7
   851
megastep@4
   852
Mix_Fading Mix_FadingChannel(int which)
megastep@4
   853
{
slouken@60
   854
	return mix_channel[which].fading;
megastep@4
   855
}
megastep@4
   856
slouken@0
   857
/* Check the status of a specific channel.
slouken@113
   858
   If the specified mix_channel is -1, check all mix channels.
slouken@0
   859
*/
slouken@0
   860
int Mix_Playing(int which)
slouken@0
   861
{
slouken@0
   862
	int status;
slouken@0
   863
slouken@0
   864
	status = 0;
slouken@0
   865
	if ( which == -1 ) {
slouken@0
   866
		int i;
slouken@0
   867
megastep@7
   868
		for ( i=0; i<num_channels; ++i ) {
slouken@113
   869
			if ((mix_channel[i].playing > 0) ||
slouken@113
   870
				(mix_channel[i].looping > 0))
slouken@113
   871
			{
slouken@0
   872
				++status;
slouken@0
   873
			}
slouken@0
   874
		}
slouken@0
   875
	} else {
slouken@113
   876
		if ((mix_channel[which].playing > 0) ||
slouken@113
   877
			(mix_channel[which].looping > 0))
slouken@113
   878
		{
slouken@0
   879
			++status;
slouken@0
   880
		}
slouken@0
   881
	}
slouken@0
   882
	return(status);
slouken@0
   883
}
slouken@0
   884
slouken@92
   885
/* rcg06072001 Get the chunk associated with a channel. */
slouken@92
   886
Mix_Chunk *Mix_GetChunk(int channel)
slouken@92
   887
{
slouken@92
   888
	Mix_Chunk *retval = NULL;
slouken@92
   889
slouken@92
   890
	if ((channel >= 0) && (channel < num_channels)) {
slouken@92
   891
		retval = mix_channel[channel].chunk;
slouken@92
   892
	}
slouken@92
   893
slouken@92
   894
	return(retval);
slouken@92
   895
}
slouken@92
   896
slouken@0
   897
/* Close the mixer, halting all playing audio */
slouken@0
   898
void Mix_CloseAudio(void)
slouken@0
   899
{
slouken@113
   900
	int i;
slouken@113
   901
slouken@0
   902
	if ( audio_opened ) {
slouken@0
   903
		if ( audio_opened == 1 ) {
slouken@113
   904
			for (i = 0; i < num_channels; i++) {
slouken@113
   905
				Mix_UnregisterAllEffects(i);
slouken@113
   906
			}
slouken@113
   907
			Mix_UnregisterAllEffects(MIX_CHANNEL_POST);
slouken@0
   908
			close_music();
slouken@0
   909
			Mix_HaltChannel(-1);
slouken@0
   910
			SDL_CloseAudio();
slouken@60
   911
			free(mix_channel);
slouken@60
   912
			mix_channel = NULL;
slouken@0
   913
		}
slouken@0
   914
		--audio_opened;
slouken@0
   915
	}
slouken@0
   916
}
slouken@0
   917
slouken@0
   918
/* Pause a particular channel (or all) */
slouken@0
   919
void Mix_Pause(int which)
slouken@0
   920
{
megastep@8
   921
	Uint32 sdl_ticks = SDL_GetTicks();
slouken@0
   922
	if ( which == -1 ) {
slouken@0
   923
		int i;
slouken@0
   924
megastep@7
   925
		for ( i=0; i<num_channels; ++i ) {
slouken@60
   926
			if ( mix_channel[i].playing > 0 ) {
slouken@60
   927
				mix_channel[i].paused = sdl_ticks;
slouken@0
   928
			}
slouken@0
   929
		}
slouken@0
   930
	} else {
slouken@60
   931
		if ( mix_channel[which].playing > 0 ) {
slouken@60
   932
			mix_channel[which].paused = sdl_ticks;
slouken@0
   933
		}
slouken@0
   934
	}
slouken@0
   935
}
slouken@0
   936
slouken@0
   937
/* Resume a paused channel */
slouken@0
   938
void Mix_Resume(int which)
slouken@0
   939
{
megastep@8
   940
	Uint32 sdl_ticks = SDL_GetTicks();
slouken@172
   941
slouken@172
   942
	SDL_LockAudio();
slouken@0
   943
	if ( which == -1 ) {
slouken@0
   944
		int i;
slouken@0
   945
megastep@7
   946
		for ( i=0; i<num_channels; ++i ) {
slouken@60
   947
			if ( mix_channel[i].playing > 0 ) {
slouken@60
   948
				if(mix_channel[i].expire > 0)
slouken@60
   949
					mix_channel[i].expire += sdl_ticks - mix_channel[i].paused;
slouken@60
   950
				mix_channel[i].paused = 0;
slouken@0
   951
			}
slouken@0
   952
		}
slouken@0
   953
	} else {
slouken@60
   954
		if ( mix_channel[which].playing > 0 ) {
slouken@60
   955
			if(mix_channel[which].expire > 0)
slouken@60
   956
				mix_channel[which].expire += sdl_ticks - mix_channel[which].paused;
slouken@60
   957
			mix_channel[which].paused = 0;
slouken@0
   958
		}
slouken@0
   959
	}
slouken@172
   960
	SDL_UnlockAudio();
slouken@0
   961
}
megastep@7
   962
megastep@13
   963
int Mix_Paused(int which)
megastep@13
   964
{
megastep@14
   965
	if ( which > num_channels )
megastep@13
   966
		return(0);
megastep@14
   967
	if ( which < 0 ) {
megastep@14
   968
		int status = 0;
megastep@14
   969
		int i;
megastep@14
   970
		for( i=0; i < num_channels; ++i ) {
slouken@60
   971
			if ( mix_channel[i].paused ) {
megastep@14
   972
				++ status;
megastep@14
   973
			}
megastep@14
   974
		}
megastep@14
   975
		return(status);
megastep@14
   976
	} else {
slouken@60
   977
		return(mix_channel[which].paused != 0);
megastep@14
   978
	}
megastep@13
   979
}
megastep@13
   980
megastep@7
   981
/* Change the group of a channel */
megastep@7
   982
int Mix_GroupChannel(int which, int tag)
megastep@7
   983
{
megastep@7
   984
	if ( which < 0 || which > num_channels )
megastep@7
   985
		return(0);
megastep@7
   986
slouken@172
   987
	SDL_LockAudio();
slouken@60
   988
	mix_channel[which].tag = tag;
slouken@172
   989
	SDL_UnlockAudio();
megastep@7
   990
	return(1);
megastep@7
   991
}
megastep@7
   992
megastep@7
   993
/* Assign several consecutive channels to a group */
megastep@7
   994
int Mix_GroupChannels(int from, int to, int tag)
megastep@7
   995
{
megastep@7
   996
	int status = 0;
megastep@7
   997
	for( ; from <= to; ++ from ) {
megastep@7
   998
		status += Mix_GroupChannel(from, tag);
megastep@7
   999
	}
megastep@7
  1000
	return(status);
megastep@7
  1001
}
megastep@7
  1002
megastep@7
  1003
/* Finds the first available channel in a group of channels */
megastep@7
  1004
int Mix_GroupAvailable(int tag)
megastep@7
  1005
{
megastep@7
  1006
	int i;
megastep@7
  1007
	for( i=0; i < num_channels; i ++ ) {
slouken@60
  1008
		if ( ((tag == -1) || (tag == mix_channel[i].tag)) &&
slouken@60
  1009
		                    (mix_channel[i].playing <= 0) )
megastep@7
  1010
			return i;
megastep@7
  1011
	}
megastep@7
  1012
	return(-1);
megastep@7
  1013
}
megastep@7
  1014
megastep@7
  1015
int Mix_GroupCount(int tag)
megastep@7
  1016
{
megastep@7
  1017
	int count = 0;
megastep@7
  1018
	int i;
megastep@7
  1019
	for( i=0; i < num_channels; i ++ ) {
slouken@60
  1020
		if ( mix_channel[i].tag==tag || tag==-1 )
megastep@7
  1021
			++ count;
megastep@7
  1022
	}
megastep@7
  1023
	return(count);
megastep@7
  1024
}
megastep@8
  1025
megastep@8
  1026
/* Finds the "oldest" sample playing in a group of channels */
megastep@8
  1027
int Mix_GroupOldest(int tag)
megastep@8
  1028
{
megastep@8
  1029
	int chan = -1;
megastep@8
  1030
	Uint32 mintime = SDL_GetTicks();
megastep@8
  1031
	int i;
megastep@8
  1032
	for( i=0; i < num_channels; i ++ ) {
slouken@60
  1033
		if ( (mix_channel[i].tag==tag || tag==-1) && mix_channel[i].playing > 0
slouken@60
  1034
			 && mix_channel[i].start_time <= mintime ) {
slouken@60
  1035
			mintime = mix_channel[i].start_time;
megastep@8
  1036
			chan = i;
megastep@8
  1037
		}
megastep@8
  1038
	}
megastep@8
  1039
	return(chan);
megastep@8
  1040
}
megastep@8
  1041
megastep@8
  1042
/* Finds the "most recent" (i.e. last) sample playing in a group of channels */
megastep@8
  1043
int Mix_GroupNewer(int tag)
megastep@8
  1044
{
megastep@8
  1045
	int chan = -1;
megastep@8
  1046
	Uint32 maxtime = 0;
megastep@8
  1047
	int i;
megastep@8
  1048
	for( i=0; i < num_channels; i ++ ) {
slouken@60
  1049
		if ( (mix_channel[i].tag==tag || tag==-1) && mix_channel[i].playing > 0
slouken@60
  1050
			 && mix_channel[i].start_time >= maxtime ) {
slouken@60
  1051
			maxtime = mix_channel[i].start_time;
megastep@8
  1052
			chan = i;
megastep@8
  1053
		}
megastep@8
  1054
	}
megastep@8
  1055
	return(chan);
megastep@8
  1056
}
slouken@113
  1057
slouken@113
  1058
slouken@113
  1059
slouken@113
  1060
/*
slouken@113
  1061
 * rcg06122001 The special effects exportable API.
slouken@113
  1062
 *  Please see effect_*.c for internally-implemented effects, such
slouken@113
  1063
 *  as Mix_SetPanning().
slouken@113
  1064
 */
slouken@113
  1065
slouken@164
  1066
/* MAKE SURE you hold the audio lock (SDL_LockAudio()) before calling this! */
slouken@113
  1067
static int _Mix_register_effect(effect_info **e, Mix_EffectFunc_t f,
slouken@164
  1068
				Mix_EffectDone_t d, void *arg)
slouken@113
  1069
{
slouken@113
  1070
	effect_info *new_e = malloc(sizeof (effect_info));
slouken@113
  1071
slouken@113
  1072
	if (!e) {
slouken@113
  1073
		Mix_SetError("Internal error");
slouken@113
  1074
		return(0);
slouken@113
  1075
	}
slouken@113
  1076
slouken@113
  1077
	if (f == NULL) {
slouken@113
  1078
		Mix_SetError("NULL effect callback");
slouken@113
  1079
		return(0);
slouken@113
  1080
	}
slouken@113
  1081
slouken@113
  1082
	if (new_e == NULL) {
slouken@113
  1083
		Mix_SetError("Out of memory");
slouken@113
  1084
		return(0);
slouken@113
  1085
	}
slouken@113
  1086
slouken@113
  1087
	new_e->callback = f;
slouken@113
  1088
	new_e->done_callback = d;
slouken@113
  1089
	new_e->udata = arg;
slouken@113
  1090
	new_e->next = NULL;
slouken@113
  1091
slouken@113
  1092
	/* add new effect to end of linked list... */
slouken@113
  1093
	if (*e == NULL) {
slouken@113
  1094
		*e = new_e;
slouken@113
  1095
	} else {
slouken@113
  1096
		effect_info *cur = *e;
slouken@113
  1097
		while (1) {
slouken@113
  1098
			if (cur->next == NULL) {
slouken@113
  1099
				cur->next = new_e;
slouken@113
  1100
				break;
slouken@113
  1101
			}
slouken@113
  1102
			cur = cur->next;
slouken@113
  1103
		}
slouken@113
  1104
	}
slouken@113
  1105
slouken@113
  1106
	return(1);
slouken@113
  1107
}
slouken@113
  1108
slouken@113
  1109
slouken@164
  1110
/* MAKE SURE you hold the audio lock (SDL_LockAudio()) before calling this! */
slouken@113
  1111
static int _Mix_remove_effect(int channel, effect_info **e, Mix_EffectFunc_t f)
slouken@113
  1112
{
slouken@113
  1113
	effect_info *cur;
slouken@113
  1114
	effect_info *prev = NULL;
slouken@113
  1115
	effect_info *next = NULL;
slouken@113
  1116
slouken@113
  1117
	if (!e) {
slouken@113
  1118
		Mix_SetError("Internal error");
slouken@113
  1119
		return(0);
slouken@113
  1120
	}
slouken@113
  1121
slouken@113
  1122
	for (cur = *e; cur != NULL; cur = cur->next) {
slouken@113
  1123
		if (cur->callback == f) {
slouken@113
  1124
			next = cur->next;
slouken@113
  1125
			if (cur->done_callback != NULL) {
slouken@113
  1126
				cur->done_callback(channel, cur->udata);
slouken@113
  1127
			}
slouken@113
  1128
			free(cur);
slouken@113
  1129
slouken@113
  1130
			if (prev == NULL) {   /* removing first item of list? */
slouken@113
  1131
				*e = next;
slouken@113
  1132
			} else {
slouken@113
  1133
				prev->next = next;
slouken@113
  1134
			}
slouken@113
  1135
			return(1);
slouken@113
  1136
		}
slouken@113
  1137
		prev = cur;
slouken@113
  1138
	}
slouken@113
  1139
slouken@113
  1140
	Mix_SetError("No such effect registered");
slouken@113
  1141
	return(0);
slouken@113
  1142
}
slouken@113
  1143
slouken@113
  1144
slouken@164
  1145
/* MAKE SURE you hold the audio lock (SDL_LockAudio()) before calling this! */
slouken@113
  1146
static int _Mix_remove_all_effects(int channel, effect_info **e)
slouken@113
  1147
{
slouken@113
  1148
	effect_info *cur;
slouken@113
  1149
	effect_info *next;
slouken@113
  1150
slouken@113
  1151
	if (!e) {
slouken@113
  1152
		Mix_SetError("Internal error");
slouken@113
  1153
		return(0);
slouken@113
  1154
	}
slouken@113
  1155
slouken@113
  1156
	for (cur = *e; cur != NULL; cur = next) {
slouken@113
  1157
		next = cur->next;
slouken@113
  1158
		if (cur->done_callback != NULL) {
slouken@113
  1159
			cur->done_callback(channel, cur->udata);
slouken@113
  1160
		}
slouken@113
  1161
		free(cur);
slouken@113
  1162
	}
slouken@113
  1163
	*e = NULL;
slouken@113
  1164
slouken@113
  1165
	return(1);
slouken@113
  1166
}
slouken@113
  1167
slouken@113
  1168
slouken@113
  1169
int Mix_RegisterEffect(int channel, Mix_EffectFunc_t f,
slouken@164
  1170
			Mix_EffectDone_t d, void *arg)
slouken@113
  1171
{
slouken@113
  1172
	effect_info **e = NULL;
slouken@164
  1173
	int retval;
slouken@113
  1174
slouken@113
  1175
	if (channel == MIX_CHANNEL_POST) {
slouken@113
  1176
		e = &posteffects;
slouken@113
  1177
	} else {
slouken@113
  1178
		if ((channel < 0) || (channel >= num_channels)) {
slouken@113
  1179
			Mix_SetError("Invalid channel number");
slouken@113
  1180
			return(0);
slouken@113
  1181
		}
slouken@113
  1182
		e = &mix_channel[channel].effects;
slouken@113
  1183
	}
slouken@113
  1184
slouken@164
  1185
	SDL_LockAudio();
slouken@164
  1186
	retval = _Mix_register_effect(e, f, d, arg);
slouken@164
  1187
	SDL_UnlockAudio();
slouken@164
  1188
	return(retval);
slouken@113
  1189
}
slouken@113
  1190
slouken@113
  1191
slouken@113
  1192
int Mix_UnregisterEffect(int channel, Mix_EffectFunc_t f)
slouken@113
  1193
{
slouken@113
  1194
	effect_info **e = NULL;
slouken@164
  1195
	int retval;
slouken@113
  1196
slouken@113
  1197
	if (channel == MIX_CHANNEL_POST) {
slouken@113
  1198
		e = &posteffects;
slouken@113
  1199
	} else {
slouken@113
  1200
		if ((channel < 0) || (channel >= num_channels)) {
slouken@113
  1201
			Mix_SetError("Invalid channel number");
slouken@113
  1202
			return(0);
slouken@113
  1203
		}
slouken@113
  1204
		e = &mix_channel[channel].effects;
slouken@113
  1205
	}
slouken@113
  1206
slouken@164
  1207
	SDL_LockAudio();
slouken@164
  1208
	retval = _Mix_remove_effect(channel, e, f);
slouken@164
  1209
	SDL_UnlockAudio();
slouken@164
  1210
	return(retval);
slouken@164
  1211
}
slouken@164
  1212
slouken@164
  1213
slouken@164
  1214
int Mix_UnregisterAllEffects(int channel)
slouken@164
  1215
{
slouken@164
  1216
	effect_info **e = NULL;
slouken@164
  1217
	int retval;
slouken@164
  1218
slouken@164
  1219
	if (channel == MIX_CHANNEL_POST) {
slouken@164
  1220
		e = &posteffects;
slouken@164
  1221
	} else {
slouken@164
  1222
		if ((channel < 0) || (channel >= num_channels)) {
slouken@164
  1223
			Mix_SetError("Invalid channel number");
slouken@164
  1224
			return(0);
slouken@164
  1225
		}
slouken@164
  1226
		e = &mix_channel[channel].effects;
slouken@164
  1227
	}
slouken@164
  1228
slouken@164
  1229
	SDL_LockAudio();
slouken@164
  1230
	retval = _Mix_remove_all_effects(channel, e);
slouken@164
  1231
	SDL_UnlockAudio();
slouken@164
  1232
	return(retval);
slouken@113
  1233
}
slouken@113
  1234
slouken@113
  1235
/* end of mixer.c ... */
slouken@113
  1236