mixer.c
author Sam Lantinga <slouken@libsdl.org>
Sun, 23 Sep 2001 22:10:03 +0000
changeset 117 c76bad2d0f4a
parent 113 c0c3018bd787
child 138 4d0dc6b4985d
permissions -rw-r--r--
*** empty log message ***
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/*
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    MIXERLIB:  An audio mixer library based on the SDL library
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    Copyright (C) 1997-1999  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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    5635-34 Springhouse Dr.
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    Pleasanton, CA 94588 (USA)
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    slouken@devolution.com
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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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static SDL_mutex *mixer_lock;
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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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/* rcg06122001 Cleanup effect callbacks. */
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static void Mix_ChannelDonePlaying(int channel)
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{
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	effect_info *i = NULL;
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	if (channel_done_callback) {
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	    channel_done_callback(channel);
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	}
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	Mix_UnregisterAllEffects(channel);
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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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	/* Grab the channels we need to mix */
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	SDL_mutexP(mixer_lock);
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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_ChannelDonePlaying(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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	SDL_mutexV(mixer_lock);
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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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	/* Create the channel lock mutex */
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	mixer_lock = SDL_CreateMutex();
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#ifndef macintosh /* Hmm.. what implications does this have? */
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	if ( mixer_lock == NULL ) {
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		SDL_CloseAudio();
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		SDL_SetError("Unable to create mixer lock");
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		return(-1);
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	}
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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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		SDL_DestroyMutex(mixer_lock);
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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_mutexP(mixer_lock);
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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_mutexV(mixer_lock);
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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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/*
slouken@91
   377
 * !!! FIXME: Ideally, we want a Mix_LoadSample_RW(), which will handle the
slouken@91
   378
 *             generic setup, then call the correct file format loader.
slouken@91
   379
 */
slouken@91
   380
slouken@0
   381
/* Load a wave file */
slouken@0
   382
Mix_Chunk *Mix_LoadWAV_RW(SDL_RWops *src, int freesrc)
slouken@0
   383
{
slouken@111
   384
	Uint32 magic;
slouken@0
   385
	Mix_Chunk *chunk;
slouken@111
   386
	SDL_AudioSpec wavespec, *loaded;
slouken@0
   387
	SDL_AudioCVT wavecvt;
slouken@41
   388
	int samplesize;
slouken@0
   389
slouken@91
   390
	/* rcg06012001 Make sure src is valid */
slouken@91
   391
	if ( ! src ) {
slouken@111
   392
		SDL_SetError("Mix_LoadWAV_RW with NULL src");
slouken@91
   393
		return(NULL);
slouken@91
   394
	}
slouken@91
   395
slouken@0
   396
	/* Make sure audio has been opened */
slouken@0
   397
	if ( ! audio_opened ) {
slouken@0
   398
		SDL_SetError("Audio device hasn't been opened");
slouken@89
   399
		if ( freesrc && src ) {
slouken@0
   400
			SDL_RWclose(src);
slouken@0
   401
		}
slouken@0
   402
		return(NULL);
slouken@0
   403
	}
slouken@0
   404
slouken@0
   405
	/* Allocate the chunk memory */
slouken@0
   406
	chunk = (Mix_Chunk *)malloc(sizeof(Mix_Chunk));
slouken@0
   407
	if ( chunk == NULL ) {
slouken@0
   408
		SDL_SetError("Out of memory");
slouken@0
   409
		if ( freesrc ) {
slouken@0
   410
			SDL_RWclose(src);
slouken@0
   411
		}
slouken@0
   412
		return(NULL);
slouken@0
   413
	}
slouken@0
   414
slouken@111
   415
	/* Find out what kind of audio file this is */
slouken@111
   416
	magic = SDL_ReadLE32(src);
slouken@111
   417
	/* Seek backwards for compatibility with older loaders */
slouken@111
   418
	SDL_RWseek(src, -sizeof(Uint32), SEEK_CUR);
slouken@111
   419
slouken@111
   420
	switch (magic) {
slouken@111
   421
		case WAVE:
slouken@117
   422
		case RIFF:
slouken@111
   423
			loaded = SDL_LoadWAV_RW(src, freesrc, &wavespec,
slouken@111
   424
					(Uint8 **)&chunk->abuf, &chunk->alen);
slouken@111
   425
			break;
slouken@111
   426
		case FORM:
slouken@111
   427
			loaded = Mix_LoadAIFF_RW(src, freesrc, &wavespec,
slouken@111
   428
					(Uint8 **)&chunk->abuf, &chunk->alen);
slouken@111
   429
			break;
slouken@111
   430
		default:
slouken@111
   431
			loaded = Mix_LoadVOC_RW(src, freesrc, &wavespec,
slouken@111
   432
					(Uint8 **)&chunk->abuf, &chunk->alen);
slouken@111
   433
			break;
slouken@111
   434
	}
slouken@111
   435
	if ( !loaded ) {
slouken@0
   436
		free(chunk);
slouken@0
   437
		return(NULL);
slouken@0
   438
	}
slouken@91
   439
slouken@0
   440
#if 0
slouken@0
   441
	PrintFormat("Audio device", &mixer);
slouken@0
   442
	PrintFormat("-- Wave file", &wavespec);
slouken@0
   443
#endif
slouken@0
   444
slouken@0
   445
	/* Build the audio converter and create conversion buffers */
slouken@0
   446
	if ( SDL_BuildAudioCVT(&wavecvt,
slouken@0
   447
			wavespec.format, wavespec.channels, wavespec.freq,
slouken@0
   448
			mixer.format, mixer.channels, mixer.freq) < 0 ) {
slouken@0
   449
		SDL_FreeWAV(chunk->abuf);
slouken@0
   450
		free(chunk);
slouken@0
   451
		return(NULL);
slouken@0
   452
	}
slouken@41
   453
	samplesize = ((wavespec.format & 0xFF)/8)*wavespec.channels;
slouken@41
   454
	wavecvt.len = chunk->alen & ~(samplesize-1);
slouken@0
   455
	wavecvt.buf = (Uint8 *)malloc(wavecvt.len*wavecvt.len_mult);
slouken@0
   456
	if ( wavecvt.buf == NULL ) {
slouken@0
   457
		SDL_SetError("Out of memory");
slouken@0
   458
		SDL_FreeWAV(chunk->abuf);
slouken@0
   459
		free(chunk);
slouken@0
   460
		return(NULL);
slouken@0
   461
	}
slouken@0
   462
	memcpy(wavecvt.buf, chunk->abuf, chunk->alen);
slouken@0
   463
	SDL_FreeWAV(chunk->abuf);
slouken@0
   464
slouken@0
   465
	/* Run the audio converter */
slouken@0
   466
	if ( SDL_ConvertAudio(&wavecvt) < 0 ) {
slouken@0
   467
		free(wavecvt.buf);
slouken@0
   468
		free(chunk);
slouken@0
   469
		return(NULL);
slouken@0
   470
	}
slouken@1
   471
	chunk->allocated = 1;
slouken@0
   472
	chunk->abuf = wavecvt.buf;
slouken@0
   473
	chunk->alen = wavecvt.len_cvt;
slouken@0
   474
	chunk->volume = MIX_MAX_VOLUME;
slouken@0
   475
	return(chunk);
slouken@0
   476
}
slouken@0
   477
slouken@1
   478
/* Load a wave file of the mixer format from a memory buffer */
slouken@1
   479
Mix_Chunk *Mix_QuickLoad_WAV(Uint8 *mem)
slouken@1
   480
{
slouken@1
   481
	Mix_Chunk *chunk;
slouken@1
   482
	Uint8 magic[4];
slouken@1
   483
slouken@1
   484
	/* Make sure audio has been opened */
slouken@1
   485
	if ( ! audio_opened ) {
slouken@1
   486
		SDL_SetError("Audio device hasn't been opened");
slouken@1
   487
		return(NULL);
slouken@1
   488
	}
slouken@1
   489
slouken@1
   490
	/* Allocate the chunk memory */
slouken@1
   491
	chunk = (Mix_Chunk *)malloc(sizeof(Mix_Chunk));
slouken@1
   492
	if ( chunk == NULL ) {
slouken@1
   493
		SDL_SetError("Out of memory");
slouken@1
   494
		return(NULL);
slouken@1
   495
	}
slouken@1
   496
slouken@1
   497
	/* Essentially just skip to the audio data (no error checking - fast) */
slouken@1
   498
	chunk->allocated = 0;
slouken@1
   499
	mem += 12; /* WAV header */
slouken@1
   500
	do {
slouken@1
   501
		memcpy(magic, mem, 4);
slouken@1
   502
		mem += 4;
slouken@1
   503
		chunk->alen = ((mem[3]<<24)|(mem[2]<<16)|(mem[1]<<8)|(mem[0]));
slouken@1
   504
		mem += 4;
slouken@1
   505
		chunk->abuf = mem;
slouken@1
   506
		mem += chunk->alen;
slouken@1
   507
	} while ( memcmp(magic, "data", 4) != 0 );
slouken@1
   508
	chunk->volume = MIX_MAX_VOLUME;
slouken@1
   509
slouken@1
   510
	return(chunk);
slouken@1
   511
}
slouken@1
   512
slouken@0
   513
/* Free an audio chunk previously loaded */
slouken@0
   514
void Mix_FreeChunk(Mix_Chunk *chunk)
slouken@0
   515
{
slouken@0
   516
	int i;
slouken@0
   517
slouken@0
   518
	/* Caution -- if the chunk is playing, the mixer will crash */
slouken@0
   519
	if ( chunk ) {
slouken@0
   520
		/* Guarantee that this chunk isn't playing */
slouken@60
   521
		if ( mix_channel ) {
slouken@60
   522
			SDL_mutexP(mixer_lock);
slouken@60
   523
			for ( i=0; i<num_channels; ++i ) {
slouken@60
   524
				if ( chunk == mix_channel[i].chunk ) {
slouken@60
   525
					mix_channel[i].playing = 0;
slouken@60
   526
				}
slouken@0
   527
			}
slouken@60
   528
			SDL_mutexV(mixer_lock);
slouken@0
   529
		}
slouken@0
   530
slouken@0
   531
		/* Actually free the chunk */
slouken@1
   532
		if ( chunk->allocated ) {
slouken@1
   533
			free(chunk->abuf);
slouken@1
   534
		}
slouken@0
   535
		free(chunk);
slouken@0
   536
	}
slouken@0
   537
}
slouken@0
   538
slouken@26
   539
/* Set a function that is called after all mixing is performed.
slouken@26
   540
   This can be used to provide real-time visual display of the audio stream
slouken@26
   541
   or add a custom mixer filter for the stream data.
slouken@26
   542
*/
slouken@26
   543
void Mix_SetPostMix(void (*mix_func)
slouken@26
   544
                    (void *udata, Uint8 *stream, int len), void *arg)
slouken@26
   545
{
slouken@26
   546
	SDL_LockAudio();
slouken@26
   547
	mix_postmix_data = arg;
slouken@26
   548
	mix_postmix = mix_func;
slouken@26
   549
	SDL_UnlockAudio();
slouken@26
   550
}
slouken@26
   551
slouken@0
   552
/* Add your own music player or mixer function.
slouken@0
   553
   If 'mix_func' is NULL, the default music player is re-enabled.
slouken@0
   554
 */
slouken@0
   555
void Mix_HookMusic(void (*mix_func)(void *udata, Uint8 *stream, int len),
slouken@0
   556
                                                                void *arg)
slouken@0
   557
{
slouken@0
   558
	SDL_LockAudio();
slouken@0
   559
	if ( mix_func != NULL ) {
slouken@0
   560
		music_data = arg;
slouken@0
   561
		mix_music = mix_func;
slouken@0
   562
	} else {
slouken@0
   563
		music_data = NULL;
slouken@0
   564
		mix_music = music_mixer;
slouken@0
   565
	}
slouken@0
   566
	SDL_UnlockAudio();
slouken@0
   567
}
slouken@0
   568
slouken@0
   569
void *Mix_GetMusicHookData(void)
slouken@0
   570
{
slouken@0
   571
	return(music_data);
slouken@0
   572
}
slouken@0
   573
slouken@92
   574
void Mix_ChannelFinished(void (*channel_finished)(int channel))
slouken@92
   575
{
slouken@92
   576
    SDL_LockAudio();
slouken@92
   577
    channel_done_callback = channel_finished;
slouken@92
   578
    SDL_UnlockAudio();
slouken@92
   579
}
slouken@92
   580
slouken@92
   581
slouken@0
   582
/* Reserve the first channels (0 -> n-1) for the application, i.e. don't allocate
slouken@0
   583
   them dynamically to the next sample if requested with a -1 value below.
slouken@0
   584
   Returns the number of reserved channels.
slouken@0
   585
 */
slouken@0
   586
int Mix_ReserveChannels(int num)
slouken@0
   587
{
megastep@7
   588
	if (num > num_channels)
megastep@7
   589
		num = num_channels;
slouken@0
   590
	reserved_channels = num;
slouken@0
   591
	return num;
slouken@0
   592
}
slouken@0
   593
slouken@0
   594
/* Play an audio chunk on a specific channel.
slouken@0
   595
   If the specified channel is -1, play on the first free channel.
megastep@7
   596
   'ticks' is the number of milliseconds at most to play the sample, or -1
megastep@7
   597
   if there is no limit.
slouken@0
   598
   Returns which channel was used to play the sound.
slouken@0
   599
*/
megastep@7
   600
int Mix_PlayChannelTimed(int which, Mix_Chunk *chunk, int loops, int ticks)
slouken@0
   601
{
slouken@0
   602
	int i;
slouken@0
   603
slouken@0
   604
	/* Don't play null pointers :-) */
slouken@0
   605
	if ( chunk == NULL ) {
slouken@0
   606
		return(-1);
slouken@0
   607
	}
slouken@0
   608
slouken@0
   609
	/* Lock the mixer while modifying the playing channels */
slouken@0
   610
	SDL_mutexP(mixer_lock);
slouken@0
   611
	{
slouken@0
   612
		/* If which is -1, play on the first free channel */
slouken@0
   613
		if ( which == -1 ) {
megastep@7
   614
			for ( i=reserved_channels; i<num_channels; ++i ) {
slouken@60
   615
				if ( mix_channel[i].playing <= 0 )
slouken@0
   616
					break;
slouken@0
   617
			}
megastep@7
   618
			if ( i == num_channels ) {
slouken@0
   619
				which = -1;
slouken@0
   620
			} else {
slouken@0
   621
				which = i;
slouken@0
   622
			}
slouken@0
   623
		}
slouken@0
   624
slouken@0
   625
		/* Queue up the audio data for this channel */
slouken@0
   626
		if ( which >= 0 ) {
megastep@8
   627
			Uint32 sdl_ticks = SDL_GetTicks();
slouken@60
   628
			mix_channel[which].samples = chunk->abuf;
slouken@60
   629
			mix_channel[which].playing = chunk->alen;
slouken@60
   630
			mix_channel[which].looping = loops;
slouken@60
   631
			mix_channel[which].chunk = chunk;
slouken@60
   632
			mix_channel[which].paused = 0;
slouken@60
   633
			mix_channel[which].fading = MIX_NO_FADING;
slouken@60
   634
			mix_channel[which].start_time = sdl_ticks;
slouken@60
   635
			mix_channel[which].expire = (ticks>0) ? (sdl_ticks + ticks) : 0;
megastep@4
   636
		}
megastep@4
   637
	}
megastep@4
   638
	SDL_mutexV(mixer_lock);
megastep@4
   639
megastep@4
   640
	/* Return the channel on which the sound is being played */
megastep@4
   641
	return(which);
megastep@4
   642
}
megastep@4
   643
megastep@7
   644
/* Change the expiration delay for a channel */
megastep@7
   645
int Mix_ExpireChannel(int which, int ticks)
megastep@7
   646
{
megastep@7
   647
	int status = 0;
megastep@7
   648
megastep@7
   649
	if ( which == -1 ) {
megastep@7
   650
		int i;
megastep@7
   651
		for ( i=0; i < num_channels; ++ i ) {
megastep@7
   652
			status += Mix_ExpireChannel(i, ticks);
megastep@7
   653
		}
megastep@7
   654
	} else if ( which < num_channels ) {
megastep@7
   655
		SDL_mutexP(mixer_lock);
slouken@60
   656
		mix_channel[which].expire = (ticks>0) ? (SDL_GetTicks() + ticks) : 0;
megastep@7
   657
		SDL_mutexV(mixer_lock);
megastep@7
   658
		++ status;
megastep@7
   659
	}
megastep@7
   660
	return(status);
megastep@7
   661
}
megastep@7
   662
megastep@4
   663
/* Fade in a sound on a channel, over ms milliseconds */
megastep@7
   664
int Mix_FadeInChannelTimed(int which, Mix_Chunk *chunk, int loops, int ms, int ticks)
megastep@4
   665
{
megastep@4
   666
	int i;
megastep@4
   667
megastep@4
   668
	/* Don't play null pointers :-) */
megastep@4
   669
	if ( chunk == NULL ) {
megastep@4
   670
		return(-1);
megastep@4
   671
	}
megastep@4
   672
megastep@4
   673
	/* Lock the mixer while modifying the playing channels */
megastep@4
   674
	SDL_mutexP(mixer_lock);
megastep@4
   675
	{
megastep@4
   676
		/* If which is -1, play on the first free channel */
megastep@4
   677
		if ( which == -1 ) {
megastep@7
   678
			for ( i=reserved_channels; i<num_channels; ++i ) {
slouken@60
   679
				if ( mix_channel[i].playing <= 0 )
megastep@4
   680
					break;
megastep@4
   681
			}
megastep@7
   682
			if ( i == num_channels ) {
megastep@4
   683
				which = -1;
megastep@4
   684
			} else {
megastep@4
   685
				which = i;
megastep@4
   686
			}
megastep@4
   687
		}
megastep@4
   688
megastep@4
   689
		/* Queue up the audio data for this channel */
megastep@4
   690
		if ( which >= 0 ) {
megastep@8
   691
			Uint32 sdl_ticks = SDL_GetTicks();
slouken@60
   692
			mix_channel[which].samples = chunk->abuf;
slouken@60
   693
			mix_channel[which].playing = chunk->alen;
slouken@60
   694
			mix_channel[which].looping = loops;
slouken@60
   695
			mix_channel[which].chunk = chunk;
slouken@60
   696
			mix_channel[which].paused = 0;
slouken@60
   697
			mix_channel[which].fading = MIX_FADING_IN;
slouken@60
   698
			mix_channel[which].fade_volume = mix_channel[which].volume;
slouken@60
   699
			mix_channel[which].volume = 0;
slouken@60
   700
			mix_channel[which].fade_length = (Uint32)ms;
slouken@60
   701
			mix_channel[which].start_time = mix_channel[which].ticks_fade = sdl_ticks;
slouken@60
   702
			mix_channel[which].expire = (ticks > 0) ? (sdl_ticks+ticks) : 0;
slouken@0
   703
		}
slouken@0
   704
	}
slouken@0
   705
	SDL_mutexV(mixer_lock);
slouken@0
   706
slouken@0
   707
	/* Return the channel on which the sound is being played */
slouken@0
   708
	return(which);
slouken@0
   709
}
slouken@0
   710
slouken@0
   711
/* Set volume of a particular channel */
slouken@0
   712
int Mix_Volume(int which, int volume)
slouken@0
   713
{
slouken@0
   714
	int i;
slouken@0
   715
	int prev_volume;
slouken@0
   716
slouken@0
   717
	if ( which == -1 ) {
slouken@0
   718
		prev_volume = 0;
megastep@7
   719
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   720
			prev_volume += Mix_Volume(i, volume);
slouken@0
   721
		}
megastep@7
   722
		prev_volume /= num_channels;
slouken@0
   723
	} else {
slouken@60
   724
		prev_volume = mix_channel[which].volume;
megastep@4
   725
		if ( volume < 0 ) {
megastep@4
   726
			volume = 0;
slouken@0
   727
		}
megastep@4
   728
		if ( volume > SDL_MIX_MAXVOLUME ) {
megastep@4
   729
			volume = SDL_MIX_MAXVOLUME;
megastep@4
   730
		}
slouken@60
   731
		mix_channel[which].volume = volume;
slouken@0
   732
	}
slouken@0
   733
	return(prev_volume);
slouken@0
   734
}
slouken@0
   735
/* Set volume of a particular chunk */
slouken@0
   736
int Mix_VolumeChunk(Mix_Chunk *chunk, int volume)
slouken@0
   737
{
slouken@0
   738
	int prev_volume;
slouken@0
   739
slouken@0
   740
	prev_volume = chunk->volume;
slouken@0
   741
	if ( volume >= 0 ) {
slouken@0
   742
		if ( volume > MIX_MAX_VOLUME ) {
slouken@0
   743
			volume = MIX_MAX_VOLUME;
slouken@0
   744
		}
slouken@0
   745
		chunk->volume = volume;
slouken@0
   746
	}
slouken@0
   747
	return(prev_volume);
slouken@0
   748
}
slouken@0
   749
slouken@0
   750
/* Halt playing of a particular channel */
slouken@0
   751
int Mix_HaltChannel(int which)
slouken@0
   752
{
slouken@0
   753
	int i;
slouken@0
   754
slouken@0
   755
	if ( which == -1 ) {
megastep@7
   756
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   757
			Mix_HaltChannel(i);
slouken@0
   758
		}
slouken@0
   759
	} else {
slouken@0
   760
		SDL_mutexP(mixer_lock);
slouken@113
   761
		if (mix_channel[which].playing) {
slouken@113
   762
			Mix_ChannelDonePlaying(which);
slouken@60
   763
		mix_channel[which].playing = 0;
slouken@113
   764
		}
slouken@60
   765
		mix_channel[which].expire = 0;
slouken@60
   766
		if(mix_channel[which].fading != MIX_NO_FADING) /* Restore volume */
slouken@60
   767
			mix_channel[which].volume = mix_channel[which].fade_volume;
slouken@60
   768
		mix_channel[which].fading = MIX_NO_FADING;
slouken@0
   769
		SDL_mutexV(mixer_lock);
slouken@0
   770
	}
slouken@0
   771
	return(0);
slouken@0
   772
}
slouken@0
   773
megastep@7
   774
/* Halt playing of a particular group of channels */
megastep@7
   775
int Mix_HaltGroup(int tag)
megastep@7
   776
{
megastep@7
   777
	int i;
megastep@7
   778
megastep@7
   779
	for ( i=0; i<num_channels; ++i ) {
slouken@60
   780
		if( mix_channel[i].tag == tag ) {
megastep@7
   781
			Mix_HaltChannel(i);
megastep@7
   782
		}
megastep@7
   783
	}
megastep@7
   784
	return(0);
megastep@7
   785
}
megastep@7
   786
megastep@4
   787
/* Fade out a channel and then stop it automatically */
megastep@4
   788
int Mix_FadeOutChannel(int which, int ms)
megastep@4
   789
{
megastep@4
   790
	int status;
megastep@4
   791
megastep@4
   792
	status = 0;
slouken@89
   793
	if ( audio_opened ) {
slouken@89
   794
		if ( which == -1 ) {
slouken@89
   795
			int i;
megastep@4
   796
slouken@89
   797
			for ( i=0; i<num_channels; ++i ) {
slouken@89
   798
				status += Mix_FadeOutChannel(i, ms);
slouken@89
   799
			}
slouken@89
   800
		} else {
slouken@89
   801
			SDL_mutexP(mixer_lock);
slouken@89
   802
			if ( mix_channel[which].playing && 
slouken@89
   803
			    (mix_channel[which].volume > 0) &&
slouken@89
   804
			    (mix_channel[which].fading != MIX_FADING_OUT) ) {
slouken@89
   805
slouken@89
   806
				mix_channel[which].fading = MIX_FADING_OUT;
slouken@89
   807
				mix_channel[which].fade_volume = mix_channel[which].volume;
slouken@89
   808
				mix_channel[which].fade_length = ms;
slouken@89
   809
				mix_channel[which].ticks_fade = SDL_GetTicks();
slouken@89
   810
				++status;
slouken@89
   811
			}
slouken@89
   812
			SDL_mutexV(mixer_lock);
megastep@4
   813
		}
megastep@4
   814
	}
megastep@4
   815
	return(status);
megastep@4
   816
}
megastep@4
   817
megastep@7
   818
/* Halt playing of a particular group of channels */
megastep@7
   819
int Mix_FadeOutGroup(int tag, int ms)
megastep@7
   820
{
megastep@7
   821
	int i;
megastep@7
   822
	int status = 0;
megastep@7
   823
	for ( i=0; i<num_channels; ++i ) {
slouken@60
   824
		if( mix_channel[i].tag == tag ) {
megastep@7
   825
			status += Mix_FadeOutChannel(i,ms);
megastep@7
   826
		}
megastep@7
   827
	}
megastep@7
   828
	return(status);
megastep@7
   829
}
megastep@7
   830
megastep@4
   831
Mix_Fading Mix_FadingChannel(int which)
megastep@4
   832
{
slouken@60
   833
	return mix_channel[which].fading;
megastep@4
   834
}
megastep@4
   835
slouken@0
   836
/* Check the status of a specific channel.
slouken@113
   837
   If the specified mix_channel is -1, check all mix channels.
slouken@0
   838
*/
slouken@0
   839
int Mix_Playing(int which)
slouken@0
   840
{
slouken@0
   841
	int status;
slouken@0
   842
slouken@0
   843
	status = 0;
slouken@0
   844
	if ( which == -1 ) {
slouken@0
   845
		int i;
slouken@0
   846
megastep@7
   847
		for ( i=0; i<num_channels; ++i ) {
slouken@113
   848
			if ((mix_channel[i].playing > 0) ||
slouken@113
   849
				(mix_channel[i].looping > 0))
slouken@113
   850
			{
slouken@0
   851
				++status;
slouken@0
   852
			}
slouken@0
   853
		}
slouken@0
   854
	} else {
slouken@113
   855
		if ((mix_channel[which].playing > 0) ||
slouken@113
   856
			(mix_channel[which].looping > 0))
slouken@113
   857
		{
slouken@0
   858
			++status;
slouken@0
   859
		}
slouken@0
   860
	}
slouken@0
   861
	return(status);
slouken@0
   862
}
slouken@0
   863
slouken@92
   864
/* rcg06072001 Get the chunk associated with a channel. */
slouken@92
   865
Mix_Chunk *Mix_GetChunk(int channel)
slouken@92
   866
{
slouken@92
   867
	Mix_Chunk *retval = NULL;
slouken@92
   868
slouken@92
   869
	if ((channel >= 0) && (channel < num_channels)) {
slouken@92
   870
		retval = mix_channel[channel].chunk;
slouken@92
   871
	}
slouken@92
   872
slouken@92
   873
	return(retval);
slouken@92
   874
}
slouken@92
   875
slouken@0
   876
/* Close the mixer, halting all playing audio */
slouken@0
   877
void Mix_CloseAudio(void)
slouken@0
   878
{
slouken@113
   879
	int i;
slouken@113
   880
slouken@0
   881
	if ( audio_opened ) {
slouken@0
   882
		if ( audio_opened == 1 ) {
slouken@113
   883
			for (i = 0; i < num_channels; i++) {
slouken@113
   884
				Mix_UnregisterAllEffects(i);
slouken@113
   885
			}
slouken@113
   886
			Mix_UnregisterAllEffects(MIX_CHANNEL_POST);
slouken@0
   887
			close_music();
slouken@0
   888
			Mix_HaltChannel(-1);
slouken@0
   889
			SDL_CloseAudio();
slouken@0
   890
			SDL_DestroyMutex(mixer_lock);
slouken@60
   891
			free(mix_channel);
slouken@60
   892
			mix_channel = NULL;
slouken@0
   893
		}
slouken@0
   894
		--audio_opened;
slouken@0
   895
	}
slouken@0
   896
}
slouken@0
   897
slouken@0
   898
/* Pause a particular channel (or all) */
slouken@0
   899
void Mix_Pause(int which)
slouken@0
   900
{
megastep@8
   901
	Uint32 sdl_ticks = SDL_GetTicks();
slouken@0
   902
	if ( which == -1 ) {
slouken@0
   903
		int i;
slouken@0
   904
megastep@7
   905
		for ( i=0; i<num_channels; ++i ) {
slouken@60
   906
			if ( mix_channel[i].playing > 0 ) {
slouken@60
   907
				mix_channel[i].paused = sdl_ticks;
slouken@0
   908
			}
slouken@0
   909
		}
slouken@0
   910
	} else {
slouken@60
   911
		if ( mix_channel[which].playing > 0 ) {
slouken@60
   912
			mix_channel[which].paused = sdl_ticks;
slouken@0
   913
		}
slouken@0
   914
	}
slouken@0
   915
}
slouken@0
   916
slouken@0
   917
/* Resume a paused channel */
slouken@0
   918
void Mix_Resume(int which)
slouken@0
   919
{
megastep@8
   920
	Uint32 sdl_ticks = SDL_GetTicks();
slouken@0
   921
	if ( which == -1 ) {
slouken@0
   922
		int i;
slouken@0
   923
megastep@8
   924
		SDL_mutexP(mixer_lock);
megastep@7
   925
		for ( i=0; i<num_channels; ++i ) {
slouken@60
   926
			if ( mix_channel[i].playing > 0 ) {
slouken@60
   927
				if(mix_channel[i].expire > 0)
slouken@60
   928
					mix_channel[i].expire += sdl_ticks - mix_channel[i].paused;
slouken@60
   929
				mix_channel[i].paused = 0;
slouken@0
   930
			}
slouken@0
   931
		}
megastep@8
   932
		SDL_mutexV(mixer_lock);
slouken@0
   933
	} else {
megastep@8
   934
		SDL_mutexP(mixer_lock);
slouken@60
   935
		if ( mix_channel[which].playing > 0 ) {
slouken@60
   936
			if(mix_channel[which].expire > 0)
slouken@60
   937
				mix_channel[which].expire += sdl_ticks - mix_channel[which].paused;
slouken@60
   938
			mix_channel[which].paused = 0;
slouken@0
   939
		}
megastep@8
   940
		SDL_mutexV(mixer_lock);
slouken@0
   941
	}
slouken@0
   942
}
megastep@7
   943
megastep@13
   944
int Mix_Paused(int which)
megastep@13
   945
{
megastep@14
   946
	if ( which > num_channels )
megastep@13
   947
		return(0);
megastep@14
   948
	if ( which < 0 ) {
megastep@14
   949
		int status = 0;
megastep@14
   950
		int i;
megastep@14
   951
		for( i=0; i < num_channels; ++i ) {
slouken@60
   952
			if ( mix_channel[i].paused ) {
megastep@14
   953
				++ status;
megastep@14
   954
			}
megastep@14
   955
		}
megastep@14
   956
		return(status);
megastep@14
   957
	} else {
slouken@60
   958
		return(mix_channel[which].paused != 0);
megastep@14
   959
	}
megastep@13
   960
}
megastep@13
   961
megastep@7
   962
/* Change the group of a channel */
megastep@7
   963
int Mix_GroupChannel(int which, int tag)
megastep@7
   964
{
megastep@7
   965
	if ( which < 0 || which > num_channels )
megastep@7
   966
		return(0);
megastep@7
   967
megastep@7
   968
	SDL_mutexP(mixer_lock);
slouken@60
   969
	mix_channel[which].tag = tag;
megastep@7
   970
	SDL_mutexV(mixer_lock);
megastep@7
   971
	return(1);
megastep@7
   972
}
megastep@7
   973
megastep@7
   974
/* Assign several consecutive channels to a group */
megastep@7
   975
int Mix_GroupChannels(int from, int to, int tag)
megastep@7
   976
{
megastep@7
   977
	int status = 0;
megastep@7
   978
	for( ; from <= to; ++ from ) {
megastep@7
   979
		status += Mix_GroupChannel(from, tag);
megastep@7
   980
	}
megastep@7
   981
	return(status);
megastep@7
   982
}
megastep@7
   983
megastep@7
   984
/* Finds the first available channel in a group of channels */
megastep@7
   985
int Mix_GroupAvailable(int tag)
megastep@7
   986
{
megastep@7
   987
	int i;
megastep@7
   988
	for( i=0; i < num_channels; i ++ ) {
slouken@60
   989
		if ( ((tag == -1) || (tag == mix_channel[i].tag)) &&
slouken@60
   990
		                    (mix_channel[i].playing <= 0) )
megastep@7
   991
			return i;
megastep@7
   992
	}
megastep@7
   993
	return(-1);
megastep@7
   994
}
megastep@7
   995
megastep@7
   996
int Mix_GroupCount(int tag)
megastep@7
   997
{
megastep@7
   998
	int count = 0;
megastep@7
   999
	int i;
megastep@7
  1000
	for( i=0; i < num_channels; i ++ ) {
slouken@60
  1001
		if ( mix_channel[i].tag==tag || tag==-1 )
megastep@7
  1002
			++ count;
megastep@7
  1003
	}
megastep@7
  1004
	return(count);
megastep@7
  1005
}
megastep@8
  1006
megastep@8
  1007
/* Finds the "oldest" sample playing in a group of channels */
megastep@8
  1008
int Mix_GroupOldest(int tag)
megastep@8
  1009
{
megastep@8
  1010
	int chan = -1;
megastep@8
  1011
	Uint32 mintime = SDL_GetTicks();
megastep@8
  1012
	int i;
megastep@8
  1013
	for( i=0; i < num_channels; i ++ ) {
slouken@60
  1014
		if ( (mix_channel[i].tag==tag || tag==-1) && mix_channel[i].playing > 0
slouken@60
  1015
			 && mix_channel[i].start_time <= mintime ) {
slouken@60
  1016
			mintime = mix_channel[i].start_time;
megastep@8
  1017
			chan = i;
megastep@8
  1018
		}
megastep@8
  1019
	}
megastep@8
  1020
	return(chan);
megastep@8
  1021
}
megastep@8
  1022
megastep@8
  1023
/* Finds the "most recent" (i.e. last) sample playing in a group of channels */
megastep@8
  1024
int Mix_GroupNewer(int tag)
megastep@8
  1025
{
megastep@8
  1026
	int chan = -1;
megastep@8
  1027
	Uint32 maxtime = 0;
megastep@8
  1028
	int i;
megastep@8
  1029
	for( i=0; i < num_channels; i ++ ) {
slouken@60
  1030
		if ( (mix_channel[i].tag==tag || tag==-1) && mix_channel[i].playing > 0
slouken@60
  1031
			 && mix_channel[i].start_time >= maxtime ) {
slouken@60
  1032
			maxtime = mix_channel[i].start_time;
megastep@8
  1033
			chan = i;
megastep@8
  1034
		}
megastep@8
  1035
	}
megastep@8
  1036
	return(chan);
megastep@8
  1037
}
slouken@113
  1038
slouken@113
  1039
slouken@113
  1040
slouken@113
  1041
/*
slouken@113
  1042
 * rcg06122001 The special effects exportable API.
slouken@113
  1043
 *  Please see effect_*.c for internally-implemented effects, such
slouken@113
  1044
 *  as Mix_SetPanning().
slouken@113
  1045
 */
slouken@113
  1046
slouken@113
  1047
static int _Mix_register_effect(effect_info **e, Mix_EffectFunc_t f,
slouken@113
  1048
											Mix_EffectDone_t d, void *arg)
slouken@113
  1049
{
slouken@113
  1050
	effect_info *new_e = malloc(sizeof (effect_info));
slouken@113
  1051
slouken@113
  1052
	if (!e) {
slouken@113
  1053
		Mix_SetError("Internal error");
slouken@113
  1054
		return(0);
slouken@113
  1055
	}
slouken@113
  1056
slouken@113
  1057
	if (f == NULL) {
slouken@113
  1058
		Mix_SetError("NULL effect callback");
slouken@113
  1059
		return(0);
slouken@113
  1060
	}
slouken@113
  1061
slouken@113
  1062
	if (new_e == NULL) {
slouken@113
  1063
		Mix_SetError("Out of memory");
slouken@113
  1064
		return(0);
slouken@113
  1065
	}
slouken@113
  1066
slouken@113
  1067
	new_e->callback = f;
slouken@113
  1068
	new_e->done_callback = d;
slouken@113
  1069
	new_e->udata = arg;
slouken@113
  1070
	new_e->next = NULL;
slouken@113
  1071
slouken@113
  1072
	SDL_LockAudio();
slouken@113
  1073
slouken@113
  1074
	/* add new effect to end of linked list... */
slouken@113
  1075
	if (*e == NULL) {
slouken@113
  1076
		*e = new_e;
slouken@113
  1077
	} else {
slouken@113
  1078
		effect_info *cur = *e;
slouken@113
  1079
		while (1) {
slouken@113
  1080
			if (cur->next == NULL) {
slouken@113
  1081
				cur->next = new_e;
slouken@113
  1082
				break;
slouken@113
  1083
			}
slouken@113
  1084
			cur = cur->next;
slouken@113
  1085
		}
slouken@113
  1086
	}
slouken@113
  1087
slouken@113
  1088
	SDL_UnlockAudio();
slouken@113
  1089
	return(1);
slouken@113
  1090
}
slouken@113
  1091
slouken@113
  1092
slouken@113
  1093
static int _Mix_remove_effect(int channel, effect_info **e, Mix_EffectFunc_t f)
slouken@113
  1094
{
slouken@113
  1095
	effect_info *cur;
slouken@113
  1096
	effect_info *prev = NULL;
slouken@113
  1097
	effect_info *next = NULL;
slouken@113
  1098
slouken@113
  1099
	if (!e) {
slouken@113
  1100
		Mix_SetError("Internal error");
slouken@113
  1101
		return(0);
slouken@113
  1102
	}
slouken@113
  1103
slouken@113
  1104
	SDL_LockAudio();
slouken@113
  1105
	for (cur = *e; cur != NULL; cur = cur->next) {
slouken@113
  1106
		if (cur->callback == f) {
slouken@113
  1107
			next = cur->next;
slouken@113
  1108
			if (cur->done_callback != NULL) {
slouken@113
  1109
				cur->done_callback(channel, cur->udata);
slouken@113
  1110
			}
slouken@113
  1111
			free(cur);
slouken@113
  1112
slouken@113
  1113
			if (prev == NULL) {   /* removing first item of list? */
slouken@113
  1114
				*e = next;
slouken@113
  1115
			} else {
slouken@113
  1116
				prev->next = next;
slouken@113
  1117
			}
slouken@113
  1118
			SDL_UnlockAudio();
slouken@113
  1119
			return(1);
slouken@113
  1120
		}
slouken@113
  1121
		prev = cur;
slouken@113
  1122
	}
slouken@113
  1123
slouken@113
  1124
	SDL_UnlockAudio();
slouken@113
  1125
	Mix_SetError("No such effect registered");
slouken@113
  1126
	return(0);
slouken@113
  1127
}
slouken@113
  1128
slouken@113
  1129
slouken@113
  1130
static int _Mix_remove_all_effects(int channel, effect_info **e)
slouken@113
  1131
{
slouken@113
  1132
	effect_info *cur;
slouken@113
  1133
	effect_info *next;
slouken@113
  1134
slouken@113
  1135
	if (!e) {
slouken@113
  1136
		Mix_SetError("Internal error");
slouken@113
  1137
		return(0);
slouken@113
  1138
	}
slouken@113
  1139
slouken@113
  1140
	SDL_LockAudio();
slouken@113
  1141
	for (cur = *e; cur != NULL; cur = next) {
slouken@113
  1142
		next = cur->next;
slouken@113
  1143
		if (cur->done_callback != NULL) {
slouken@113
  1144
			cur->done_callback(channel, cur->udata);
slouken@113
  1145
		}
slouken@113
  1146
		free(cur);
slouken@113
  1147
	}
slouken@113
  1148
	*e = NULL;
slouken@113
  1149
	SDL_UnlockAudio();
slouken@113
  1150
slouken@113
  1151
	return(1);
slouken@113
  1152
}
slouken@113
  1153
slouken@113
  1154
slouken@113
  1155
int Mix_RegisterEffect(int channel, Mix_EffectFunc_t f,
slouken@113
  1156
						Mix_EffectDone_t d, void *arg)
slouken@113
  1157
{
slouken@113
  1158
	effect_info **e = NULL;
slouken@113
  1159
slouken@113
  1160
	if (channel == MIX_CHANNEL_POST) {
slouken@113
  1161
		e = &posteffects;
slouken@113
  1162
	} else {
slouken@113
  1163
		if ((channel < 0) || (channel >= num_channels)) {
slouken@113
  1164
			Mix_SetError("Invalid channel number");
slouken@113
  1165
			return(0);
slouken@113
  1166
		}
slouken@113
  1167
		e = &mix_channel[channel].effects;
slouken@113
  1168
	}
slouken@113
  1169
slouken@113
  1170
	return(_Mix_register_effect(e, f, d, arg));
slouken@113
  1171
}
slouken@113
  1172
slouken@113
  1173
slouken@113
  1174
int Mix_UnregisterEffect(int channel, Mix_EffectFunc_t f)
slouken@113
  1175
{
slouken@113
  1176
	effect_info **e = NULL;
slouken@113
  1177
slouken@113
  1178
	if (channel == MIX_CHANNEL_POST) {
slouken@113
  1179
		e = &posteffects;
slouken@113
  1180
	} else {
slouken@113
  1181
		if ((channel < 0) || (channel >= num_channels)) {
slouken@113
  1182
			Mix_SetError("Invalid channel number");
slouken@113
  1183
			return(0);
slouken@113
  1184
		}
slouken@113
  1185
		e = &mix_channel[channel].effects;
slouken@113
  1186
	}
slouken@113
  1187
	return(_Mix_remove_effect(channel, e, f));
slouken@113
  1188
}
slouken@113
  1189
slouken@113
  1190
slouken@113
  1191
int Mix_UnregisterAllEffects(int channel)
slouken@113
  1192
{
slouken@113
  1193
	effect_info **e = NULL;
slouken@113
  1194
slouken@113
  1195
	if (channel == MIX_CHANNEL_POST) {
slouken@113
  1196
		e = &posteffects;
slouken@113
  1197
	} else {
slouken@113
  1198
		if ((channel < 0) || (channel >= num_channels)) {
slouken@113
  1199
			Mix_SetError("Invalid channel number");
slouken@113
  1200
			return(0);
slouken@113
  1201
		}
slouken@113
  1202
		e = &mix_channel[channel].effects;
slouken@113
  1203
	}
slouken@113
  1204
slouken@113
  1205
	return(_Mix_remove_all_effects(channel, e));
slouken@113
  1206
}
slouken@113
  1207
slouken@113
  1208
/* end of mixer.c ... */
slouken@113
  1209