mixer.c
author Sam Lantinga <slouken@lokigames.com>
Sun, 26 Dec 1999 11:17:50 +0000
changeset 26 25edca541dc9
parent 24 a25bb2d59ce8
child 29 44b09d6e1170
permissions -rw-r--r--
Added a post-mix callback, and updated configure.in for Win32 cross-compile
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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 "mixer.h"
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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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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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	int 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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	int fade_length;
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	Uint32 ticks_fade;
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} *channel = 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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void *mix_postmix_data = NULL;
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/* Support for user defined music functions, plus the default one */
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extern int 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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void *music_data = NULL;
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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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	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( ! channel[i].paused ) {
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			if ( channel[i].expire > 0 && channel[i].expire < sdl_ticks ) {
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				/* Expiration delay for that channel is reached */
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				channel[i].playing = 0;
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				channel[i].fading = MIX_NO_FADING;
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				channel[i].expire = -1;
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			} else if ( channel[i].fading != MIX_NO_FADING ) {
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				Uint32 ticks = sdl_ticks - channel[i].ticks_fade;
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				if( ticks > channel[i].fade_length ) {
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					if( channel[i].fading == MIX_FADING_OUT ) {
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						channel[i].playing = 0;
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						channel[i].expire = -1;
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						Mix_Volume(i, channel[i].fading); /* Restore the volume */
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					}
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					channel[i].fading = MIX_NO_FADING;
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				} else {
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					if( channel[i].fading == MIX_FADING_OUT ) {
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						Mix_Volume(i, (channel[i].fade_volume * (channel[i].fade_length-ticks))
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								   / channel[i].fade_length );
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					} else {
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						Mix_Volume(i, (channel[i].fade_volume * ticks) / channel[i].fade_length );
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					}
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				}
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			}
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			if ( channel[i].playing > 0 ) {
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				volume = (channel[i].volume*channel[i].chunk->volume) /
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					MIX_MAX_VOLUME;
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				mixable = channel[i].playing;
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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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				if ( channel[i].looping && mixable < len ) {
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					char buffer[len]; /* Hum, gcc feature */
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					int remaining = len - mixable;
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					memcpy(buffer, channel[i].samples, mixable);
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					memcpy(buffer+mixable, channel[i].chunk->abuf, remaining);
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					SDL_MixAudio(stream, buffer, len, volume);
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					--channel[i].looping;
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					channel[i].samples = channel[i].chunk->abuf + remaining;
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					channel[i].playing = channel[i].chunk->alen - remaining;
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				} else {
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					if ( mixable > len ) {
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						mixable = len;
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					}
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					SDL_MixAudio(stream,channel[i].samples,mixable,volume);
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					channel[i].samples += mixable;
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					channel[i].playing -= mixable;
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					if ( ! channel[i].playing && channel[i].looping ) {
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						if ( --channel[i].looping ) {
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							channel[i].samples = channel[i].chunk->abuf;
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							channel[i].playing = channel[i].chunk->alen;
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						}
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					}
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				}
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			}
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		}
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	}
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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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/* Open the mixer with a certain desired audio format */
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int Mix_OpenAudio(int frequency, Uint16 format, int channels, 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 = channels;
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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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	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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	/* 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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	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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		channel[i].chunk = NULL;
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		channel[i].playing = 0;
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		channel[i].looping = 0;
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		channel[i].volume = SDL_MIX_MAXVOLUME;
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		channel[i].tag = -1;
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		channel[i].expire = -1;
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	}
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	Mix_VolumeMusic(SDL_MIX_MAXVOLUME);
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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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	channel = (struct _Mix_Channel *) realloc(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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			channel[i].chunk = NULL;
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			channel[i].playing = 0;
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			channel[i].looping = 0;
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			channel[i].volume = SDL_MIX_MAXVOLUME;
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			channel[i].tag = -1;
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			channel[i].expire = -1;
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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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/* 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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	Mix_Chunk *chunk;
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	SDL_AudioSpec wavespec;
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	SDL_AudioCVT wavecvt;
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	/* Make sure audio has been opened */
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	if ( ! audio_opened ) {
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		SDL_SetError("Audio device hasn't been opened");
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		if ( freesrc ) {
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			SDL_RWclose(src);
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		}
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		return(NULL);
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	}
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	/* Allocate the chunk memory */
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	chunk = (Mix_Chunk *)malloc(sizeof(Mix_Chunk));
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	if ( chunk == NULL ) {
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		SDL_SetError("Out of memory");
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		if ( freesrc ) {
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			SDL_RWclose(src);
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		}
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		return(NULL);
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	}
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	/* Load the WAV file into the chunk */
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	if ( SDL_LoadWAV_RW(src, freesrc,
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		&wavespec, (Uint8 **)&chunk->abuf, &chunk->alen) == NULL ) {
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		free(chunk);
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		return(NULL);
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	}
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#if 0
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	PrintFormat("Audio device", &mixer);
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	PrintFormat("-- Wave file", &wavespec);
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#endif
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	/* Build the audio converter and create conversion buffers */
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	if ( SDL_BuildAudioCVT(&wavecvt,
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			wavespec.format, wavespec.channels, wavespec.freq,
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			mixer.format, mixer.channels, mixer.freq) < 0 ) {
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		SDL_FreeWAV(chunk->abuf);
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		free(chunk);
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		return(NULL);
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	}
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	wavecvt.len = chunk->alen;
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	wavecvt.buf = (Uint8 *)malloc(wavecvt.len*wavecvt.len_mult);
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	if ( wavecvt.buf == NULL ) {
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		SDL_SetError("Out of memory");
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		SDL_FreeWAV(chunk->abuf);
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		free(chunk);
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		return(NULL);
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	}
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	memcpy(wavecvt.buf, chunk->abuf, chunk->alen);
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	SDL_FreeWAV(chunk->abuf);
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	/* Run the audio converter */
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	if ( SDL_ConvertAudio(&wavecvt) < 0 ) {
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		free(wavecvt.buf);
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		free(chunk);
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		return(NULL);
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	}
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	chunk->allocated = 1;
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	chunk->abuf = wavecvt.buf;
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	chunk->alen = wavecvt.len_cvt;
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	chunk->volume = MIX_MAX_VOLUME;
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	return(chunk);
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}
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/* Load a wave file of the mixer format from a memory buffer */
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Mix_Chunk *Mix_QuickLoad_WAV(Uint8 *mem)
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{
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	Mix_Chunk *chunk;
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	Uint8 magic[4];
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	/* Make sure audio has been opened */
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	if ( ! audio_opened ) {
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		SDL_SetError("Audio device hasn't been opened");
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		return(NULL);
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	}
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	/* Allocate the chunk memory */
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	chunk = (Mix_Chunk *)malloc(sizeof(Mix_Chunk));
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	if ( chunk == NULL ) {
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		SDL_SetError("Out of memory");
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		return(NULL);
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	}
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	/* Essentially just skip to the audio data (no error checking - fast) */
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	chunk->allocated = 0;
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	mem += 12; /* WAV header */
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	do {
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		memcpy(magic, mem, 4);
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		mem += 4;
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		chunk->alen = ((mem[3]<<24)|(mem[2]<<16)|(mem[1]<<8)|(mem[0]));
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		mem += 4;
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		chunk->abuf = mem;
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		mem += chunk->alen;
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	} while ( memcmp(magic, "data", 4) != 0 );
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	chunk->volume = MIX_MAX_VOLUME;
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	return(chunk);
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}
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/* Free an audio chunk previously loaded */
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void Mix_FreeChunk(Mix_Chunk *chunk)
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{
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	int i;
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   374
slouken@0
   375
	/* Caution -- if the chunk is playing, the mixer will crash */
slouken@0
   376
	if ( chunk ) {
slouken@0
   377
		/* Guarantee that this chunk isn't playing */
slouken@0
   378
		SDL_mutexP(mixer_lock);
megastep@7
   379
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   380
			if ( chunk == channel[i].chunk ) {
slouken@0
   381
				channel[i].playing = 0;
slouken@0
   382
			}
slouken@0
   383
		}
slouken@0
   384
		SDL_mutexV(mixer_lock);
slouken@0
   385
slouken@0
   386
		/* Actually free the chunk */
slouken@1
   387
		if ( chunk->allocated ) {
slouken@1
   388
			free(chunk->abuf);
slouken@1
   389
		}
slouken@0
   390
		free(chunk);
slouken@0
   391
	}
slouken@0
   392
}
slouken@0
   393
slouken@26
   394
/* Set a function that is called after all mixing is performed.
slouken@26
   395
   This can be used to provide real-time visual display of the audio stream
slouken@26
   396
   or add a custom mixer filter for the stream data.
slouken@26
   397
*/
slouken@26
   398
void Mix_SetPostMix(void (*mix_func)
slouken@26
   399
                    (void *udata, Uint8 *stream, int len), void *arg)
slouken@26
   400
{
slouken@26
   401
	SDL_LockAudio();
slouken@26
   402
	mix_postmix_data = arg;
slouken@26
   403
	mix_postmix = mix_func;
slouken@26
   404
	SDL_UnlockAudio();
slouken@26
   405
}
slouken@26
   406
slouken@0
   407
/* Add your own music player or mixer function.
slouken@0
   408
   If 'mix_func' is NULL, the default music player is re-enabled.
slouken@0
   409
 */
slouken@0
   410
void Mix_HookMusic(void (*mix_func)(void *udata, Uint8 *stream, int len),
slouken@0
   411
                                                                void *arg)
slouken@0
   412
{
slouken@0
   413
	SDL_LockAudio();
slouken@0
   414
	if ( mix_func != NULL ) {
slouken@0
   415
		music_data = arg;
slouken@0
   416
		mix_music = mix_func;
slouken@0
   417
	} else {
slouken@0
   418
		music_data = NULL;
slouken@0
   419
		mix_music = music_mixer;
slouken@0
   420
	}
slouken@0
   421
	SDL_UnlockAudio();
slouken@0
   422
}
slouken@0
   423
slouken@0
   424
void *Mix_GetMusicHookData(void)
slouken@0
   425
{
slouken@0
   426
	return(music_data);
slouken@0
   427
}
slouken@0
   428
slouken@0
   429
/* Reserve the first channels (0 -> n-1) for the application, i.e. don't allocate
slouken@0
   430
   them dynamically to the next sample if requested with a -1 value below.
slouken@0
   431
   Returns the number of reserved channels.
slouken@0
   432
 */
slouken@0
   433
int Mix_ReserveChannels(int num)
slouken@0
   434
{
megastep@7
   435
	if (num > num_channels)
megastep@7
   436
		num = num_channels;
slouken@0
   437
	reserved_channels = num;
slouken@0
   438
	return num;
slouken@0
   439
}
slouken@0
   440
slouken@0
   441
/* Play an audio chunk on a specific channel.
slouken@0
   442
   If the specified channel is -1, play on the first free channel.
megastep@7
   443
   'ticks' is the number of milliseconds at most to play the sample, or -1
megastep@7
   444
   if there is no limit.
slouken@0
   445
   Returns which channel was used to play the sound.
slouken@0
   446
*/
megastep@7
   447
int Mix_PlayChannelTimed(int which, Mix_Chunk *chunk, int loops, int ticks)
slouken@0
   448
{
slouken@0
   449
	int i;
slouken@0
   450
slouken@0
   451
	/* Don't play null pointers :-) */
slouken@0
   452
	if ( chunk == NULL ) {
slouken@0
   453
		return(-1);
slouken@0
   454
	}
slouken@0
   455
slouken@0
   456
	/* Lock the mixer while modifying the playing channels */
slouken@0
   457
	SDL_mutexP(mixer_lock);
slouken@0
   458
	{
slouken@0
   459
		/* If which is -1, play on the first free channel */
slouken@0
   460
		if ( which == -1 ) {
megastep@7
   461
			for ( i=reserved_channels; i<num_channels; ++i ) {
slouken@0
   462
				if ( channel[i].playing <= 0 )
slouken@0
   463
					break;
slouken@0
   464
			}
megastep@7
   465
			if ( i == num_channels ) {
slouken@0
   466
				which = -1;
slouken@0
   467
			} else {
slouken@0
   468
				which = i;
slouken@0
   469
			}
slouken@0
   470
		}
slouken@0
   471
slouken@0
   472
		/* Queue up the audio data for this channel */
slouken@0
   473
		if ( which >= 0 ) {
megastep@8
   474
			Uint32 sdl_ticks = SDL_GetTicks();
slouken@0
   475
			channel[which].samples = chunk->abuf;
slouken@0
   476
			channel[which].playing = chunk->alen;
slouken@0
   477
			channel[which].looping = loops;
slouken@0
   478
			channel[which].chunk = chunk;
slouken@0
   479
			channel[which].paused = 0;
megastep@4
   480
			channel[which].fading = MIX_NO_FADING;
megastep@8
   481
			channel[which].start_time = sdl_ticks;
megastep@8
   482
			channel[which].expire = (ticks>0) ? (sdl_ticks + ticks) : -1;
megastep@4
   483
		}
megastep@4
   484
	}
megastep@4
   485
	SDL_mutexV(mixer_lock);
megastep@4
   486
megastep@4
   487
	/* Return the channel on which the sound is being played */
megastep@4
   488
	return(which);
megastep@4
   489
}
megastep@4
   490
megastep@7
   491
/* Change the expiration delay for a channel */
megastep@7
   492
int Mix_ExpireChannel(int which, int ticks)
megastep@7
   493
{
megastep@7
   494
	int status = 0;
megastep@7
   495
megastep@7
   496
	if ( which == -1 ) {
megastep@7
   497
		int i;
megastep@7
   498
		for ( i=0; i < num_channels; ++ i ) {
megastep@7
   499
			status += Mix_ExpireChannel(i, ticks);
megastep@7
   500
		}
megastep@7
   501
	} else if ( which < num_channels ) {
megastep@7
   502
		SDL_mutexP(mixer_lock);
megastep@7
   503
		channel[which].expire = (ticks>0) ? (SDL_GetTicks() + ticks) : -1;		
megastep@7
   504
		SDL_mutexV(mixer_lock);
megastep@7
   505
		++ status;
megastep@7
   506
	}
megastep@7
   507
	return(status);
megastep@7
   508
}
megastep@7
   509
megastep@4
   510
/* Fade in a sound on a channel, over ms milliseconds */
megastep@7
   511
int Mix_FadeInChannelTimed(int which, Mix_Chunk *chunk, int loops, int ms, int ticks)
megastep@4
   512
{
megastep@4
   513
	int i;
megastep@4
   514
megastep@4
   515
	/* Don't play null pointers :-) */
megastep@4
   516
	if ( chunk == NULL ) {
megastep@4
   517
		return(-1);
megastep@4
   518
	}
megastep@4
   519
megastep@4
   520
	/* Lock the mixer while modifying the playing channels */
megastep@4
   521
	SDL_mutexP(mixer_lock);
megastep@4
   522
	{
megastep@4
   523
		/* If which is -1, play on the first free channel */
megastep@4
   524
		if ( which == -1 ) {
megastep@7
   525
			for ( i=reserved_channels; i<num_channels; ++i ) {
megastep@4
   526
				if ( channel[i].playing <= 0 )
megastep@4
   527
					break;
megastep@4
   528
			}
megastep@7
   529
			if ( i == num_channels ) {
megastep@4
   530
				which = -1;
megastep@4
   531
			} else {
megastep@4
   532
				which = i;
megastep@4
   533
			}
megastep@4
   534
		}
megastep@4
   535
megastep@4
   536
		/* Queue up the audio data for this channel */
megastep@4
   537
		if ( which >= 0 ) {
megastep@8
   538
			Uint32 sdl_ticks = SDL_GetTicks();
megastep@4
   539
			channel[which].samples = chunk->abuf;
megastep@4
   540
			channel[which].playing = chunk->alen;
megastep@4
   541
			channel[which].looping = loops;
megastep@4
   542
			channel[which].chunk = chunk;
megastep@4
   543
			channel[which].paused = 0;
megastep@4
   544
			channel[which].fading = MIX_FADING_IN;
megastep@4
   545
			channel[which].fade_volume = channel[which].volume;
megastep@4
   546
			channel[which].volume = 0;
megastep@4
   547
			channel[which].fade_length = ms;
megastep@8
   548
			channel[which].start_time = channel[which].ticks_fade = sdl_ticks;
megastep@8
   549
			channel[which].expire = (ticks > 0) ? (sdl_ticks+ticks) : -1;
slouken@0
   550
		}
slouken@0
   551
	}
slouken@0
   552
	SDL_mutexV(mixer_lock);
slouken@0
   553
slouken@0
   554
	/* Return the channel on which the sound is being played */
slouken@0
   555
	return(which);
slouken@0
   556
}
slouken@0
   557
slouken@0
   558
/* Set volume of a particular channel */
slouken@0
   559
int Mix_Volume(int which, int volume)
slouken@0
   560
{
slouken@0
   561
	int i;
slouken@0
   562
	int prev_volume;
slouken@0
   563
slouken@0
   564
	if ( which == -1 ) {
slouken@0
   565
		prev_volume = 0;
megastep@7
   566
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   567
			prev_volume += Mix_Volume(i, volume);
slouken@0
   568
		}
megastep@7
   569
		prev_volume /= num_channels;
slouken@0
   570
	} else {
slouken@0
   571
		prev_volume = channel[which].volume;
megastep@4
   572
		if ( volume < 0 ) {
megastep@4
   573
			volume = 0;
slouken@0
   574
		}
megastep@4
   575
		if ( volume > SDL_MIX_MAXVOLUME ) {
megastep@4
   576
			volume = SDL_MIX_MAXVOLUME;
megastep@4
   577
		}
megastep@4
   578
		channel[which].volume = volume;
slouken@0
   579
	}
slouken@0
   580
	return(prev_volume);
slouken@0
   581
}
slouken@0
   582
/* Set volume of a particular chunk */
slouken@0
   583
int Mix_VolumeChunk(Mix_Chunk *chunk, int volume)
slouken@0
   584
{
slouken@0
   585
	int prev_volume;
slouken@0
   586
slouken@0
   587
	prev_volume = chunk->volume;
slouken@0
   588
	if ( volume >= 0 ) {
slouken@0
   589
		if ( volume > MIX_MAX_VOLUME ) {
slouken@0
   590
			volume = MIX_MAX_VOLUME;
slouken@0
   591
		}
slouken@0
   592
		chunk->volume = volume;
slouken@0
   593
	}
slouken@0
   594
	return(prev_volume);
slouken@0
   595
}
slouken@0
   596
slouken@0
   597
/* Halt playing of a particular channel */
slouken@0
   598
int Mix_HaltChannel(int which)
slouken@0
   599
{
slouken@0
   600
	int i;
slouken@0
   601
slouken@0
   602
	if ( which == -1 ) {
megastep@7
   603
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   604
			Mix_HaltChannel(i);
slouken@0
   605
		}
slouken@0
   606
	} else {
slouken@0
   607
		SDL_mutexP(mixer_lock);
slouken@0
   608
		channel[which].playing = 0;
megastep@7
   609
		channel[which].expire = -1;
megastep@4
   610
		if(channel[which].fading != MIX_NO_FADING) /* Restore volume */
megastep@4
   611
			channel[which].volume = channel[which].fade_volume;
megastep@4
   612
		channel[which].fading = MIX_NO_FADING;
slouken@0
   613
		SDL_mutexV(mixer_lock);
slouken@0
   614
	}
slouken@0
   615
	return(0);
slouken@0
   616
}
slouken@0
   617
megastep@7
   618
/* Halt playing of a particular group of channels */
megastep@7
   619
int Mix_HaltGroup(int tag)
megastep@7
   620
{
megastep@7
   621
	int i;
megastep@7
   622
megastep@7
   623
	for ( i=0; i<num_channels; ++i ) {
megastep@7
   624
		if( channel[i].tag == tag ) {
megastep@7
   625
			Mix_HaltChannel(i);
megastep@7
   626
		}
megastep@7
   627
	}
megastep@7
   628
	return(0);
megastep@7
   629
}
megastep@7
   630
megastep@4
   631
/* Fade out a channel and then stop it automatically */
megastep@4
   632
int Mix_FadeOutChannel(int which, int ms)
megastep@4
   633
{
megastep@4
   634
	int status;
megastep@4
   635
megastep@4
   636
	status = 0;
megastep@4
   637
	if ( which == -1 ) {
megastep@4
   638
		int i;
megastep@4
   639
megastep@7
   640
		for ( i=0; i<num_channels; ++i ) {
megastep@4
   641
			status += Mix_FadeOutChannel(i,ms);
megastep@4
   642
		}
megastep@4
   643
	} else {
megastep@4
   644
		SDL_mutexP(mixer_lock);
megastep@4
   645
		if ( channel[which].playing && channel[which].volume>0 && 
megastep@4
   646
			 channel[which].fading==MIX_NO_FADING ) {
megastep@4
   647
megastep@4
   648
			channel[which].fading = MIX_FADING_OUT;
megastep@4
   649
			channel[which].fade_volume = channel[which].volume;
megastep@4
   650
			channel[which].fade_length = ms;
megastep@4
   651
			channel[which].ticks_fade = SDL_GetTicks();
megastep@4
   652
			++ status;
megastep@4
   653
		}
megastep@4
   654
		SDL_mutexV(mixer_lock);
megastep@4
   655
	}
megastep@4
   656
	return(status);
megastep@4
   657
}
megastep@4
   658
megastep@7
   659
/* Halt playing of a particular group of channels */
megastep@7
   660
int Mix_FadeOutGroup(int tag, int ms)
megastep@7
   661
{
megastep@7
   662
	int i;
megastep@7
   663
	int status = 0;
megastep@7
   664
	for ( i=0; i<num_channels; ++i ) {
megastep@7
   665
		if( channel[i].tag == tag ) {
megastep@7
   666
			status += Mix_FadeOutChannel(i,ms);
megastep@7
   667
		}
megastep@7
   668
	}
megastep@7
   669
	return(status);
megastep@7
   670
}
megastep@7
   671
megastep@4
   672
Mix_Fading Mix_FadingChannel(int which)
megastep@4
   673
{
megastep@4
   674
	return channel[which].fading;
megastep@4
   675
}
megastep@4
   676
slouken@0
   677
/* Check the status of a specific channel.
slouken@0
   678
   If the specified channel is -1, check all channels.
slouken@0
   679
*/
slouken@0
   680
int Mix_Playing(int which)
slouken@0
   681
{
slouken@0
   682
	int status;
slouken@0
   683
slouken@0
   684
	status = 0;
slouken@0
   685
	if ( which == -1 ) {
slouken@0
   686
		int i;
slouken@0
   687
megastep@7
   688
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   689
			if ( channel[i].playing > 0 ) {
slouken@0
   690
				++status;
slouken@0
   691
			}
slouken@0
   692
		}
slouken@0
   693
	} else {
slouken@0
   694
		if ( channel[which].playing > 0 ) {
slouken@0
   695
			++status;
slouken@0
   696
		}
slouken@0
   697
	}
slouken@0
   698
	return(status);
slouken@0
   699
}
slouken@0
   700
slouken@0
   701
/* Close the mixer, halting all playing audio */
slouken@0
   702
void Mix_CloseAudio(void)
slouken@0
   703
{
slouken@0
   704
	if ( audio_opened ) {
slouken@0
   705
		if ( audio_opened == 1 ) {
slouken@0
   706
			close_music();
slouken@0
   707
			Mix_HaltChannel(-1);
slouken@0
   708
			SDL_CloseAudio();
slouken@0
   709
			SDL_DestroyMutex(mixer_lock);
megastep@8
   710
			free(channel);
megastep@7
   711
			channel = NULL;
slouken@0
   712
		}
slouken@0
   713
		--audio_opened;
slouken@0
   714
	}
slouken@0
   715
}
slouken@0
   716
slouken@0
   717
/* Pause a particular channel (or all) */
slouken@0
   718
void Mix_Pause(int which)
slouken@0
   719
{
megastep@8
   720
	Uint32 sdl_ticks = SDL_GetTicks();
slouken@0
   721
	if ( which == -1 ) {
slouken@0
   722
		int i;
slouken@0
   723
megastep@7
   724
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   725
			if ( channel[i].playing > 0 ) {
megastep@8
   726
				channel[i].paused = sdl_ticks;
slouken@0
   727
			}
slouken@0
   728
		}
slouken@0
   729
	} else {
slouken@0
   730
		if ( channel[which].playing > 0 ) {
megastep@8
   731
			channel[which].paused = sdl_ticks;
slouken@0
   732
		}
slouken@0
   733
	}
slouken@0
   734
}
slouken@0
   735
slouken@0
   736
/* Resume a paused channel */
slouken@0
   737
void Mix_Resume(int which)
slouken@0
   738
{
megastep@8
   739
	Uint32 sdl_ticks = SDL_GetTicks();
slouken@0
   740
	if ( which == -1 ) {
slouken@0
   741
		int i;
slouken@0
   742
megastep@8
   743
		SDL_mutexP(mixer_lock);
megastep@7
   744
		for ( i=0; i<num_channels; ++i ) {
slouken@0
   745
			if ( channel[i].playing > 0 ) {
megastep@8
   746
				if(channel[i].expire > 0)
megastep@8
   747
					channel[i].expire += sdl_ticks - channel[i].paused;
slouken@0
   748
				channel[i].paused = 0;
slouken@0
   749
			}
slouken@0
   750
		}
megastep@8
   751
		SDL_mutexV(mixer_lock);
slouken@0
   752
	} else {
megastep@8
   753
		SDL_mutexP(mixer_lock);
slouken@0
   754
		if ( channel[which].playing > 0 ) {
megastep@8
   755
			if(channel[which].expire > 0)
megastep@8
   756
				channel[which].expire += sdl_ticks - channel[which].paused;
slouken@0
   757
			channel[which].paused = 0;
slouken@0
   758
		}
megastep@8
   759
		SDL_mutexV(mixer_lock);
slouken@0
   760
	}
slouken@0
   761
}
megastep@7
   762
megastep@13
   763
int Mix_Paused(int which)
megastep@13
   764
{
megastep@14
   765
	if ( which > num_channels )
megastep@13
   766
		return(0);
megastep@14
   767
	if ( which < 0 ) {
megastep@14
   768
		int status = 0;
megastep@14
   769
		int i;
megastep@14
   770
		for( i=0; i < num_channels; ++i ) {
megastep@14
   771
			if ( channel[i].paused ) {
megastep@14
   772
				++ status;
megastep@14
   773
			}
megastep@14
   774
		}
megastep@14
   775
		return(status);
megastep@14
   776
	} else {
megastep@14
   777
		return(channel[which].paused != 0);
megastep@14
   778
	}
megastep@13
   779
}
megastep@13
   780
megastep@7
   781
/* Change the group of a channel */
megastep@7
   782
int Mix_GroupChannel(int which, int tag)
megastep@7
   783
{
megastep@7
   784
	if ( which < 0 || which > num_channels )
megastep@7
   785
		return(0);
megastep@7
   786
megastep@7
   787
	SDL_mutexP(mixer_lock);
megastep@7
   788
	channel[which].tag = tag;
megastep@7
   789
	SDL_mutexV(mixer_lock);
megastep@7
   790
	return(1);
megastep@7
   791
}
megastep@7
   792
megastep@7
   793
/* Assign several consecutive channels to a group */
megastep@7
   794
int Mix_GroupChannels(int from, int to, int tag)
megastep@7
   795
{
megastep@7
   796
	int status = 0;
megastep@7
   797
	for( ; from <= to; ++ from ) {
megastep@7
   798
		status += Mix_GroupChannel(from, tag);
megastep@7
   799
	}
megastep@7
   800
	return(status);
megastep@7
   801
}
megastep@7
   802
megastep@7
   803
/* Finds the first available channel in a group of channels */
megastep@7
   804
int Mix_GroupAvailable(int tag)
megastep@7
   805
{
megastep@7
   806
	int i;
megastep@7
   807
	for( i=0; i < num_channels; i ++ ) {
megastep@7
   808
		if ( (channel[i].tag==tag || tag==-1) && channel[i].playing<=0 )
megastep@7
   809
			return i;
megastep@7
   810
	}
megastep@7
   811
	return(-1);
megastep@7
   812
}
megastep@7
   813
megastep@7
   814
int Mix_GroupCount(int tag)
megastep@7
   815
{
megastep@7
   816
	int count = 0;
megastep@7
   817
	int i;
megastep@7
   818
	for( i=0; i < num_channels; i ++ ) {
megastep@7
   819
		if ( channel[i].tag==tag || tag==-1 )
megastep@7
   820
			++ count;
megastep@7
   821
	}
megastep@7
   822
	return(count);
megastep@7
   823
}
megastep@8
   824
megastep@8
   825
/* Finds the "oldest" sample playing in a group of channels */
megastep@8
   826
int Mix_GroupOldest(int tag)
megastep@8
   827
{
megastep@8
   828
	int chan = -1;
megastep@8
   829
	Uint32 mintime = SDL_GetTicks();
megastep@8
   830
	int i;
megastep@8
   831
	for( i=0; i < num_channels; i ++ ) {
megastep@8
   832
		if ( (channel[i].tag==tag || tag==-1) && channel[i].playing > 0 
megastep@8
   833
			 && channel[i].start_time <= mintime ) {
megastep@8
   834
			mintime = channel[i].start_time;
megastep@8
   835
			chan = i;
megastep@8
   836
		}
megastep@8
   837
	}
megastep@8
   838
	return(chan);
megastep@8
   839
}
megastep@8
   840
megastep@8
   841
/* Finds the "most recent" (i.e. last) sample playing in a group of channels */
megastep@8
   842
int Mix_GroupNewer(int tag)
megastep@8
   843
{
megastep@8
   844
	int chan = -1;
megastep@8
   845
	Uint32 maxtime = 0;
megastep@8
   846
	int i;
megastep@8
   847
	for( i=0; i < num_channels; i ++ ) {
megastep@8
   848
		if ( (channel[i].tag==tag || tag==-1) && channel[i].playing > 0 
megastep@8
   849
			 && channel[i].start_time >= maxtime ) {
megastep@8
   850
			maxtime = channel[i].start_time;
megastep@8
   851
			chan = i;
megastep@8
   852
		}
megastep@8
   853
	}
megastep@8
   854
	return(chan);
megastep@8
   855
}