#include "SoundMixer.h"


struct _Mix_Music {
  Mix_MusicType type;
  union 
  {
#ifdef WAV_MUSIC
    WAVStream *wave;
#endif
  } data;
  Mix_Fading fading;
  int fade_step;
  int fade_steps;
  int error;
};

struct _Mix_effectinfo
{
	Mix_EffectFunc_t callback;
	Mix_EffectDone_t done_callback;
	void *udata;
	struct _Mix_effectinfo *next;
};

static int reserved_channels = 0;
/* Used to calculate fading steps */
static int ms_per_step;
static const char **music_decoders = NULL;
typedef _Mix_effectinfo effect_info;

static effect_info *posteffects = NULL;
extern void music_mixer(void *udata, Uint8 *stream, int len);
static void (*mix_music)(void *udata, Uint8 *stream, int len) = music_mixer;
int volatile music_active = 1;
static int music_loops = 0;
static void *music_data = NULL;
static int audio_opened = 0;
static SDL_AudioSpec mixer;
static int num_channels;
static const char **chunk_decoders = NULL;
static int num_decoders = 0;
static int music_volume = MIX_MAX_VOLUME;
static void (*music_finished_hook)(void) = NULL;

extern void close_music(void);
static Mix_Music * volatile music_playing = NULL;
static int  music_internal_play(Mix_Music *music, double position);
static void music_internal_halt(void);
static void music_internal_volume(int volume);
static void (*channel_done_callback)(int channel) = NULL;
static void (*mix_postmix)(void *udata, Uint8 *stream, int len) = NULL;
static void *mix_postmix_data = NULL;

static int _Mix_remove_all_effects(int channel, effect_info **e);


static struct _Mix_Channel {
	Mix_Chunk *chunk;
	int playing;
	int paused;
	Uint8 *samples;
	int volume;
	int looping;
	int tag;
	Uint32 expire;
	Uint32 start_time;
	Mix_Fading fading;
	int fade_volume;
	int fade_volume_reset;
	Uint32 fade_length;
	Uint32 ticks_fade;
	effect_info *effects;
} *mix_channel = NULL;

/* Check the status of a specific channel.
   If the specified mix_channel is -1, check all mix channels.
*/

/* Load raw audio data of the mixer format from a memory buffer */
Mix_Chunk *Mix_QuickLoad_RAW(Uint8 *mem, Uint32 len)
{
  Mix_Chunk *chunk;
  /* Make sure audio has been opened */
  if ( ! audio_opened )
  {
    SDL_SetError("Audio device hasn't been opened");
    return(NULL);
  };
  /* Allocate the chunk memory */
  chunk = (Mix_Chunk *)SDL_malloc(sizeof(Mix_Chunk));
  if ( chunk == NULL )
  {
    SDL_SetError("Out of memory");
    return(NULL);
  };
  /* Essentially just point at the audio data (no error checking - fast) */
  chunk->allocated = 0;
  chunk->alen = len;
  chunk->abuf = mem;
  chunk->volume = MIX_MAX_VOLUME;
  return(chunk);
}

static int checkchunkintegral(Mix_Chunk *chunk)
{
  int frame_width = 1;
  if ((mixer.format & 0xFF) == 16) frame_width = 2;
  frame_width *= mixer.channels;
  while (chunk->alen % frame_width) chunk->alen--;
  return chunk->alen;
}

/*
 * rcg06122001 Cleanup effect callbacks.
 *  MAKE SURE SDL_LockAudio() is called before this (or you're in the
 *   audio callback).
 */
static void _Mix_channel_done_playing(int channel)
{
  if (channel_done_callback)
  {
    channel_done_callback(channel);
  };
  /*
   * Call internal function directly, to avoid locking audio from
   *   inside audio callback.
   */
  _Mix_remove_all_effects(channel, &mix_channel[channel].effects);
}


/* Play an audio chunk on a specific channel.
   If the specified channel is -1, play on the first free channel.
   'ticks' is the number of milliseconds at most to play the sample, or -1
   if there is no limit.
   Returns which channel was used to play the sound.
*/
int Mix_PlayChannelTimed(int which, Mix_Chunk *chunk, int loops, int ticks)
{
  int i;
  /* Don't play null pointers :-) */
  if ( chunk == NULL )
  {
    Mix_SetError("Tried to play a NULL chunk");
    return(-1);
  };
  if ( !checkchunkintegral(chunk))
  {
    Mix_SetError("Tried to play a chunk with a bad frame");
    return(-1);
  };
  /* Lock the mixer while modifying the playing channels */
  SDL_LockAudio();
  {
    /* If which is -1, play on the first free channel */
    if ( which == -1 )
    {
      for ( i=reserved_channels; i<num_channels; ++i )
      {
        if ( mix_channel[i].playing <= 0 )
        {
	  break;
        };
      };
      if ( i == num_channels )
      {
        Mix_SetError("No free channels available");
	which = -1;
      }
      else
      {
        which = i;
      };
    };
    /* Queue up the audio data for this channel */
    if ( which >= 0 && which < num_channels )
    {
      Uint32 sdl_ticks = SDL_GetTicks();
      if (Mix_Playing(which))
      {
        _Mix_channel_done_playing(which);
      };
      mix_channel[which].samples = chunk->abuf;
      mix_channel[which].playing = chunk->alen;
      mix_channel[which].looping = loops;
      mix_channel[which].chunk = chunk;
      mix_channel[which].paused = 0;
      mix_channel[which].fading = MIX_NO_FADING;
      mix_channel[which].start_time = sdl_ticks;
      mix_channel[which].expire = (ticks>0) ? (sdl_ticks + ticks) : 0;
    };
  };
  SDL_UnlockAudio();
  /* Return the channel on which the sound is being played */
  return(which);
}


int Mix_Playing(int which)
{
  int status;
  status = 0;
  if ( which == -1 )
  {
    int i;
    for ( i=0; i<num_channels; ++i )
    {
      if ((mix_channel[i].playing > 0) ||
				(mix_channel[i].looping > 0))
      {
        ++status;
      };
    };
  }
  else if ( which < num_channels )
  {
    if ( (mix_channel[which].playing > 0) ||
		     (mix_channel[which].looping > 0) )
    {
      ++status;
    };
  };
  return(status);
}

/* Free an audio chunk previously loaded */
void Mix_FreeChunk(Mix_Chunk *chunk)
{
  int i;
  /* Caution -- if the chunk is playing, the mixer will crash */
  if ( chunk )
  {
    /* Guarantee that this chunk isn't playing */
    SDL_LockAudio();
    if ( mix_channel )
    {
      for ( i=0; i<num_channels; ++i )
      {
        if ( chunk == mix_channel[i].chunk )
        {
          mix_channel[i].playing = 0;
	  mix_channel[i].looping = 0;
	};
      };
    };
    SDL_UnlockAudio();
    /* Actually free the chunk */
    if ( chunk->allocated )
    {
      SDL_free(chunk->abuf);
    };
    SDL_free(chunk);
  };
}


/* MAKE SURE you hold the audio lock (SDL_LockAudio()) before calling this! */
static int _Mix_remove_effect(int channel, effect_info **e, Mix_EffectFunc_t f)
{
  effect_info *cur;
  effect_info *prev = NULL;
  effect_info *next = NULL;
  if (!e)
  {
    Mix_SetError("Internal error");
    return(0);
  };
  for (cur = *e; cur != NULL; cur = cur->next)
  {
    if (cur->callback == f)
    {
      next = cur->next;
      if (cur->done_callback != NULL)
      {
        cur->done_callback(channel, cur->udata);
      };
      SDL_free(cur);
      if (prev == NULL)
      {   /* removing first item of list? */
        *e = next;
      }
       else
      {
        prev->next = next;
      };
      return(1);
    };
    prev = cur;
  };
  Mix_SetError("No such effect registered");
  return(0);
}


/* MAKE SURE you hold the audio lock (SDL_LockAudio()) before calling this! */
int _Mix_UnregisterEffect_locked(int channel, Mix_EffectFunc_t f)
{
  effect_info **e = NULL;
  if (channel == MIX_CHANNEL_POST)
  {
    e = &posteffects;
  } 
  else 
  {
    if ((channel < 0) || (channel >= num_channels)) 
    {
      Mix_SetError("Invalid channel number");
      return(0);
    };
    e = &mix_channel[channel].effects;
  };
  return _Mix_remove_effect(channel, e, f);
}

/* MAKE SURE you hold the audio lock (SDL_LockAudio()) before calling this! */
int _Mix_UnregisterAllEffects_locked(int channel)
{
  effect_info **e = NULL;
  if (channel == MIX_CHANNEL_POST)
  {
    e = &posteffects;
  }
  else
  {
    if ((channel < 0) || (channel >= num_channels))
    {
      Mix_SetError("Invalid channel number");
      return(0);
    };
    e = &mix_channel[channel].effects;
  };
  return _Mix_remove_all_effects(channel, e);
}


int Mix_UnregisterAllEffects(int channel)
{
  int retval;
  SDL_LockAudio();
  retval = _Mix_UnregisterAllEffects_locked(channel);
  SDL_UnlockAudio();
  return(retval);
}


/* Should we favor speed over memory usage and/or quality of output? */
int _Mix_effects_max_speed = 0;


void _Mix_InitEffects(void)
{
  _Mix_effects_max_speed = (SDL_getenv(MIX_EFFECTSMAXSPEED) != NULL);
}


/* Set the playing music position */
int music_internal_position(double position)
{
  int retval = 0;
  switch (music_playing->type) 
  {
    default:
    /* TODO: Implement this for other music backends */
    retval = -1;
    break;
  };
  return(retval);
}


/* Set the music's initial volume */
static void music_internal_initialize_volume(void)
{
  if ( music_playing->fading == MIX_FADING_IN ) 
  {
    music_internal_volume(0);
  }
   else 
  {
    music_internal_volume(music_volume);
  };
}


/* Play a music chunk.  Returns 0, or -1 if there was an error.
 */
static int music_internal_play(Mix_Music *music, double position)
{
  int retval = 0;
  /* Note the music we're playing */
  if ( music_playing ) 
  {
    music_internal_halt();
  };
  music_playing = music;
  /* Set the initial volume */
  if ( music->type != MUS_MOD ) 
  {
    music_internal_initialize_volume();
  };
  /* Set up for playback */
  switch (music->type) 
  {
#ifdef WAV_MUSIC
    case MUS_WAV:
		WAVStream_Start(music->data.wave);
		break;
#endif
    default:
      Mix_SetError("Can't play unknown music type");
      retval = -1;
      break;
  };
skip:
  /* Set the playback position, note any errors if an offset is used */
  if ( retval == 0 ) 
  {
    if ( position > 0.0 ) 
    {
      if ( music_internal_position(position) < 0 ) 
      {
        Mix_SetError("Position not implemented for music type");
	retval = -1;
      };
    }
     else 
    {
      music_internal_position(0.0);
    };
  }
  /* If the setup failed, we're not playing any music anymore */
  if ( retval < 0 ) 
  {
    music_playing = NULL;
  };
  return(retval);
}


/* Check the status of the music */
static int music_internal_playing()
{
  int playing = 1;
  if (music_playing == NULL)
  {
    return 0;
  };
  switch (music_playing->type) 
  {
#ifdef WAV_MUSIC
    case MUS_WAV:
    if ( ! WAVStream_Active() ) 
    {
      playing = 0;
    };
    break;
#endif
    default:
      playing = 0;
      break;
  };
skip:
  return(playing);
}


/* If music isn't playing, halt it if no looping is required, restart it */
/* otherwhise. NOP if the music is playing */
static int music_halt_or_loop (void)
{
  /* Restart music if it has to loop */
  if (!music_internal_playing()) 
  {
    /* Restart music if it has to loop at a high level */
    if (music_loops)
    {
      Mix_Fading current_fade;
      --music_loops;
      current_fade = music_playing->fading;
      music_internal_play(music_playing, 0.0);
      music_playing->fading = current_fade;
    }
    else
    {
      music_internal_halt();
      if (music_finished_hook)
      {
	music_finished_hook();
      };
      return 0;
    };
  };
  return 1;
}


static void music_internal_halt(void)
{
  switch (music_playing->type) 
  {
#ifdef WAV_MUSIC
    case MUS_WAV:
      WAVStream_Stop();
      break;
#endif
    default:
      /* Unknown music type?? */
      return;
  };
skip:
  music_playing->fading = MIX_NO_FADING;
  music_playing = NULL;
}


void music_mixer(void *udata, Uint8 *stream, int len)
{
  int left = 0;
  if ( music_playing && music_active ) 
  {
    /* Handle fading */
    if ( music_playing->fading != MIX_NO_FADING ) 
    {
      if ( music_playing->fade_step++ < music_playing->fade_steps ) 
      {
        int volume;
	int fade_step = music_playing->fade_step;
	int fade_steps = music_playing->fade_steps;
	if ( music_playing->fading == MIX_FADING_OUT ) 
        {
	  volume = (music_volume * (fade_steps-fade_step)) / fade_steps;
	} 
        else 
        { /* Fading in */
	  volume = (music_volume * fade_step) / fade_steps;
	}
	music_internal_volume(volume);
      } 
      else 
      {
        if ( music_playing->fading == MIX_FADING_OUT ) 
        {
	  music_internal_halt();
	  if ( music_finished_hook ) 
          {
	    music_finished_hook();
	  };
	  return;
	}
	music_playing->fading = MIX_NO_FADING;
      }
    }
    music_halt_or_loop();
    if (!music_internal_playing())
    {
      return;
    };
    switch (music_playing->type) 
    {
#ifdef WAV_MUSIC
      case MUS_WAV:
	left = WAVStream_PlaySome(stream, len);
	break;
#endif
      default:
      /* Unknown music type?? */
	break;
    };
  }
skip:
  /* Handle seamless music looping */
  if (left > 0 && left < len) 
  {
    music_halt_or_loop();
    if (music_internal_playing())
    {
      music_mixer(udata, stream+(len-left), left);
    };
  };
}

static int _Mix_remove_all_effects(int channel, effect_info **e)
{
  effect_info *cur;
  effect_info *next;
  if (!e)
  {
    Mix_SetError("Internal error");
    return(0);
  };
  for (cur = *e; cur != NULL; cur = next) 
  {
    next = cur->next;
    if (cur->done_callback != NULL) 
    {
      cur->done_callback(channel, cur->udata);
    };
    SDL_free(cur);
  };
  *e = NULL;
  return(1);
}

static void *Mix_DoEffects(int chan, void *snd, int len)
{
  int posteffect = (chan == MIX_CHANNEL_POST);
  effect_info *e = ((posteffect) ? posteffects : mix_channel[chan].effects);
  void *buf = snd;
  if (e != NULL)  /* are there any registered effects? */
  {		  /* if this is the postmix, we can just overwrite the original. */
    if (!posteffect) 
    {
      buf = SDL_malloc(len);
      if (buf == NULL) 
      {
        return(snd);
      };
      memcpy(buf, snd, len);
    };
    for (; e != NULL; e = e->next) 
    {
      if (e->callback != NULL) 
      {
        e->callback(chan, buf, len, e->udata);
      };
    };
  };
  /* be sure to SDL_free() the return value if != snd ... */
  return(buf);
}

int Mix_Volume(int which, int volume)
{
  int i;
  int prev_volume = 0;
  if ( which == -1 ) 
  {
    for ( i=0; i<num_channels; ++i ) 
    {
      prev_volume += Mix_Volume(i, volume);
    };
    prev_volume /= num_channels;
    } 
    else if ( which < num_channels ) 
    {
      prev_volume = mix_channel[which].volume;
      if ( volume >= 0 ) 
      {
        if ( volume > SDL_MIX_MAXVOLUME ) 
        {
	  volume = SDL_MIX_MAXVOLUME;
	};
	mix_channel[which].volume = volume;
      };
    };
    return(prev_volume);
}

unsigned long UI_GetSystemTime(void);

static void mix_channels(void *udata, Uint8 *stream, int len)
{
  Uint8 *mix_input;
  int i, mixable, volume = SDL_MIX_MAXVOLUME;
  Uint32 sdl_ticks;

#if SDL_VERSION_ATLEAST(1, 3, 0)
  /* Need to initialize the stream in SDL 1.3+ */
  memset(stream, mixer.silence, len);
#endif
  /* Mix the music (must be done before the channels are added) */
  if ( music_active || (mix_music != music_mixer) ) 
  {
    mix_music(music_data, stream, len);
  };
  /* Mix any playing channels... */
  sdl_ticks = SDL_GetTicks();
  for ( i=0; i<num_channels; ++i ) 
  {
    if( ! mix_channel[i].paused ) 
    {
      if ( mix_channel[i].expire > 0 && mix_channel[i].expire < sdl_ticks ) 
      {
        /* Expiration delay for that channel is reached */
	mix_channel[i].playing = 0;
	mix_channel[i].looping = 0;
	mix_channel[i].fading = MIX_NO_FADING;
	mix_channel[i].expire = 0;
	_Mix_channel_done_playing(i);
      } 
      else if ( mix_channel[i].fading != MIX_NO_FADING ) 
      {
        Uint32 ticks = sdl_ticks - mix_channel[i].ticks_fade;
	if( ticks > mix_channel[i].fade_length ) 
        {
	  Mix_Volume(i, mix_channel[i].fade_volume_reset); /* Restore the volume */
	  if( mix_channel[i].fading == MIX_FADING_OUT ) 
          {
	    mix_channel[i].playing = 0;
	    mix_channel[i].looping = 0;
	    mix_channel[i].expire = 0;
	    _Mix_channel_done_playing(i);
	  };
	  mix_channel[i].fading = MIX_NO_FADING;
	} 
        else 
        {
	  if( mix_channel[i].fading == MIX_FADING_OUT )
          {
	    Mix_Volume(i, (mix_channel[i].fade_volume * (mix_channel[i].fade_length-ticks))
		   / mix_channel[i].fade_length );
       	  } 
          else 
          {
	    Mix_Volume(i, (mix_channel[i].fade_volume * ticks) / mix_channel[i].fade_length );
	  };
	};
      }
      if ( mix_channel[i].playing > 0 ) 
      {
        int index = 0;
	int remaining = len;
	while (mix_channel[i].playing > 0 && index < len) 
        {
	  remaining = len - index;
	  volume = (mix_channel[i].volume*mix_channel[i].chunk->volume) / MIX_MAX_VOLUME;
	  mixable = mix_channel[i].playing;
	  if ( mixable > remaining ) 
          {
	    mixable = remaining;
	  };
   	  mix_input = (Uint8 *)Mix_DoEffects
                               (i, mix_channel[i].samples, mixable);
          //printf("SDL_MixAudio(channel %d,len=%d@%d)\n", i,len,
          //              (unsigned int)UI_GetSystemTime());
	  SDL_MixAudio(stream+index,mix_input,mixable,volume);
	  if (mix_input != mix_channel[i].samples)
	  SDL_free(mix_input);
          mix_channel[i].samples += mixable;
	  mix_channel[i].playing -= mixable;
	  index += mixable;
  	  /* rcg06072001 Alert app if channel is done playing. */
	  if (!mix_channel[i].playing && !mix_channel[i].looping) 
          {
	    _Mix_channel_done_playing(i);
	  };
	};
	/* If looping the sample and we are at its end, make sure
	   we will still return a full buffer */
	while ( mix_channel[i].looping && index < len ) 
        {
	  int alen = mix_channel[i].chunk->alen;
	  remaining = len - index;
	  if (remaining > alen) 
          {
	    remaining = alen;
	  };
          mix_input = (Uint8 *)Mix_DoEffects
                                (i, mix_channel[i].chunk->abuf, remaining);
	  SDL_MixAudio(stream+index, mix_input, remaining, volume);
	  if (mix_input != mix_channel[i].chunk->abuf)
          {
	    SDL_free(mix_input);
          };
          --mix_channel[i].looping;
	  mix_channel[i].samples = mix_channel[i].chunk->abuf + remaining;
	  mix_channel[i].playing = mix_channel[i].chunk->alen - remaining;
	  index += remaining;
	};
	if ( ! mix_channel[i].playing && mix_channel[i].looping ) 
        {
	  --mix_channel[i].looping;
	  mix_channel[i].samples = mix_channel[i].chunk->abuf;
	  mix_channel[i].playing = mix_channel[i].chunk->alen;
	};
      };
    };
  };

  /* rcg06122001 run posteffects... */
  Mix_DoEffects(MIX_CHANNEL_POST, stream, len);
  if ( mix_postmix ) 
  {
    mix_postmix(mix_postmix_data, stream, len);
  };
}


static void music_internal_volume(int volume)
{
  switch (music_playing->type) 
  {
#ifdef WAV_MUSIC
    case MUS_WAV:
      WAVStream_SetVolume(volume);
      break;
#endif
    default:
	/* Unknown music type?? */
	break;
  };
}

int Mix_VolumeMusic(int volume)
{
  int prev_volume;
  prev_volume = music_volume;
  if ( volume < 0 ) 
  {
    return prev_volume;
  };
  if ( volume > SDL_MIX_MAXVOLUME ) 
  {
    volume = SDL_MIX_MAXVOLUME;
  };
  music_volume = volume;
  SDL_LockAudio();
  if ( music_playing ) 
  {
    music_internal_volume(music_volume);
  };
  SDL_UnlockAudio();
  return prev_volume;
}






/* Open the mixer with a certain desired audio format */
int Mix_OpenAudio(int frequency, Uint16 format, int nchannels, int chunksize)
{
	int i;
	SDL_AudioSpec desired;

	/* If the mixer is already opened, increment open count */
	if ( audio_opened ) {
		if ( format == mixer.format && nchannels == mixer.channels ) {
			++audio_opened;
			return(0);
		}
		while ( audio_opened ) {
			Mix_CloseAudio();
		}
	}

	/* Set the desired format and frequency */
	desired.freq = frequency;
	desired.format = format;
	desired.channels = nchannels;
	desired.samples = chunksize;
	desired.callback = mix_channels;
	desired.userdata = NULL;

	/* Accept nearly any audio format */
	if ( SDL_OpenAudio(&desired, &mixer) < 0 ) {
		return(-1);
	}
#if 0
	PrintFormat("Audio device", &mixer);
#endif

//	/* Initialize the music players */
//	if ( open_music(&mixer) < 0 ) {
//		SDL_CloseAudio();
//		return(-1);
//	}

	num_channels = MIX_CHANNELS;
	mix_channel = (struct _Mix_Channel *) SDL_malloc(num_channels * sizeof(struct _Mix_Channel));

	/* Clear out the audio channels */
	for ( i=0; i<num_channels; ++i ) {
		mix_channel[i].chunk = NULL;
		mix_channel[i].playing = 0;
		mix_channel[i].looping = 0;
		mix_channel[i].volume = SDL_MIX_MAXVOLUME;
		mix_channel[i].fade_volume = SDL_MIX_MAXVOLUME;
		mix_channel[i].fade_volume_reset = SDL_MIX_MAXVOLUME;
		mix_channel[i].fading = MIX_NO_FADING;
		mix_channel[i].tag = -1;
		mix_channel[i].expire = 0;
		mix_channel[i].effects = NULL;
		mix_channel[i].paused = 0;
	}
	Mix_VolumeMusic(SDL_MIX_MAXVOLUME);

	_Mix_InitEffects();

	/* This list is (currently) decided at build time. */
//	add_chunk_decoder("WAVE");
//	add_chunk_decoder("AIFF");
//	add_chunk_decoder("VOC");
#ifdef OGG_MUSIC
//	add_chunk_decoder("OGG");
#endif
#ifdef FLAC_MUSIC
//	add_chunk_decoder("FLAC");
#endif

	audio_opened = 1;
	SDL_PauseAudio(0);
	return(0);
}

int Mix_HaltMusic(void)
{
  SDL_LockAudio();
  if ( music_playing )
  {
    music_internal_halt();
  };
  SDL_UnlockAudio();
  return(0);
}


/* Uninitialize the music players */
void close_music(void)
{
  Mix_HaltMusic();
  /* rcg06042009 report available decoders at runtime. */
  SDL_free(music_decoders);
  music_decoders = NULL;
  num_decoders = 0;
  ms_per_step = 0;
}

/* Halt playing of a particular channel */
int Mix_HaltChannel(int which)
{
  int i;
  if ( which == -1 )
  {
    for ( i=0; i<num_channels; ++i )
    {
      Mix_HaltChannel(i);
    };
  } 
  else if ( which < num_channels )
  {
    SDL_LockAudio();
    if (mix_channel[which].playing)
    {
      _Mix_channel_done_playing(which);
      mix_channel[which].playing = 0;
      mix_channel[which].looping = 0;
    };
    mix_channel[which].expire = 0;
    if(mix_channel[which].fading != MIX_NO_FADING)
    { /* Restore volume */
      mix_channel[which].volume = mix_channel[which].fade_volume_reset;
    };
    mix_channel[which].fading = MIX_NO_FADING;
    SDL_UnlockAudio();
  };
  return(0);
}

typedef struct _Eff_positionargs
{
    volatile float left_f;
    volatile float right_f;
    volatile Uint8 left_u8;
    volatile Uint8 right_u8;
    volatile float left_rear_f;
    volatile float right_rear_f;
    volatile float center_f;
    volatile float lfe_f;
    volatile Uint8 left_rear_u8;
    volatile Uint8 right_rear_u8;
    volatile Uint8 center_u8;
    volatile Uint8 lfe_u8;
    volatile float distance_f;
    volatile Uint8 distance_u8;
    volatile Sint16 room_angle;
    volatile int in_use;
    volatile int channels;
} position_args;


static position_args **pos_args_array = NULL;
static position_args *pos_args_global = NULL;
static int position_channels = 0;

void _Eff_PositionDeinit(void)
{
  int i;
  for (i = 0; i < position_channels; i++)
  {
    SDL_free(pos_args_array[i]);
  };
  position_channels = 0;
  SDL_free(pos_args_global);
  pos_args_global = NULL;
  SDL_free(pos_args_array);
  pos_args_array = NULL;
}


void _Mix_DeinitEffects(void)
{
  _Eff_PositionDeinit();
}


void Mix_CloseAudio(void)
{
  int i;
  if ( audio_opened )
  {
    if ( audio_opened == 1 )
    {
      for (i = 0; i < num_channels; i++)
      {
        Mix_UnregisterAllEffects(i);
      };
      Mix_UnregisterAllEffects(MIX_CHANNEL_POST);
      close_music();
      Mix_HaltChannel(-1);
      _Mix_DeinitEffects();
      SDL_CloseAudio();
      SDL_free(mix_channel);
      mix_channel = NULL;
      /* rcg06042009 report available decoders at runtime. */
      SDL_free(chunk_decoders);
      chunk_decoders = NULL;
      num_decoders = 0;
    };
    --audio_opened;
  };
}