SDL_mixer.h

/*
    SDL_mixer:  An audio mixer library based on the SDL library
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/

/* $Id$ */

#ifndef _SDL_MIXER_H
#define _SDL_MIXER_H

#include "SDL_types.h"
#include "SDL_rwops.h"
#include "SDL_audio.h"
#include "SDL_endian.h"
#include "SDL_version.h"
#include "begin_code.h"

/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif

/* Printable format: "%d.%d.%d", MAJOR, MINOR, PATCHLEVEL
*/
#define SDL_MIXER_MAJOR_VERSION	1
#define SDL_MIXER_MINOR_VERSION	2
#define SDL_MIXER_PATCHLEVEL    10

/* This macro can be used to fill a version structure with the compile-time
 * version of the SDL_mixer library.
 */
#define SDL_MIXER_VERSION(X)						\
{									\
	(X)->major = SDL_MIXER_MAJOR_VERSION;				\
	(X)->minor = SDL_MIXER_MINOR_VERSION;				\
	(X)->patch = SDL_MIXER_PATCHLEVEL;				\
}

/* Backwards compatibility */
#define MIX_MAJOR_VERSION	SDL_MIXER_MAJOR_VERSION
#define MIX_MINOR_VERSION	SDL_MIXER_MINOR_VERSION
#define MIX_PATCHLEVEL		SDL_MIXER_PATCHLEVEL
#define MIX_VERSION(X)		SDL_MIXER_VERSION(X)

/* This function gets the version of the dynamically linked SDL_mixer library.
   it should NOT be used to fill a version structure, instead you should
   use the SDL_MIXER_VERSION() macro.
 */
extern DECLSPEC const SDL_version * SDLCALL Mix_Linked_Version(void);


/* The default mixer has 8 simultaneous mixing channels */
#ifndef MIX_CHANNELS
#define MIX_CHANNELS	8
#endif

/* Good default values for a PC soundcard */
#define MIX_DEFAULT_FREQUENCY	22050
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
#define MIX_DEFAULT_FORMAT	AUDIO_S16LSB
#else
#define MIX_DEFAULT_FORMAT	AUDIO_S16MSB
#endif
#define MIX_DEFAULT_CHANNELS	2
#define MIX_MAX_VOLUME		128	/* Volume of a chunk */

/* The internal format for an audio chunk */
typedef struct Mix_Chunk {
	int allocated;
	Uint8 *abuf;
	Uint32 alen;
	Uint8 volume;		/* Per-sample volume, 0-128 */
} Mix_Chunk;

/* The different fading types supported */
typedef enum {
	MIX_NO_FADING,
	MIX_FADING_OUT,
	MIX_FADING_IN
} Mix_Fading;

typedef enum {
	MUS_NONE,
	MUS_CMD,
	MUS_WAV,
	MUS_MOD,
	MUS_MID,
	MUS_OGG,
	MUS_MP3,
	MUS_MP3_MAD,
	MUS_FLAC
} Mix_MusicType;

/* The internal format for a music chunk interpreted via mikmod */
typedef struct _Mix_Music Mix_Music;

/* Open the mixer with a certain audio format */
extern DECLSPEC int SDLCALL Mix_OpenAudio(int frequency, Uint16 format, int channels,
							int chunksize);

/* Dynamically change the number of channels managed by the mixer.
   If decreasing the number of channels, the upper channels are
   stopped.
   This function returns the new number of allocated channels.
 */
extern DECLSPEC int SDLCALL Mix_AllocateChannels(int numchans);

/* Find out what the actual audio device parameters are.
   This function returns 1 if the audio has been opened, 0 otherwise.
 */
extern DECLSPEC int SDLCALL Mix_QuerySpec(int *frequency,Uint16 *format,int *channels);

/* Load a wave file or a music (.mod .s3m .it .xm) file */
extern DECLSPEC Mix_Chunk * SDLCALL Mix_LoadWAV_RW(SDL_RWops *src, int freesrc);
#define Mix_LoadWAV(file)	Mix_LoadWAV_RW(SDL_RWFromFile(file, "rb"), 1)
extern DECLSPEC Mix_Music * SDLCALL Mix_LoadMUS(const char *file);

/* Load a music file from an SDL_RWop object (Ogg and MikMod specific currently)
   Matt Campbell (matt@campbellhome.dhs.org) April 2000 */
extern DECLSPEC Mix_Music * SDLCALL Mix_LoadMUS_RW(SDL_RWops *rw);

/* Load a wave file of the mixer format from a memory buffer */
extern DECLSPEC Mix_Chunk * SDLCALL Mix_QuickLoad_WAV(Uint8 *mem);

/* Load raw audio data of the mixer format from a memory buffer */
extern DECLSPEC Mix_Chunk * SDLCALL Mix_QuickLoad_RAW(Uint8 *mem, Uint32 len);

/* Free an audio chunk previously loaded */
extern DECLSPEC void SDLCALL Mix_FreeChunk(Mix_Chunk *chunk);
extern DECLSPEC void SDLCALL Mix_FreeMusic(Mix_Music *music);

/* Get a list of chunk/music decoders that this build of SDL_mixer provides.
   This list can change between builds AND runs of the program, if external
   libraries that add functionality become available.
   You must successfully call Mix_OpenAudio() before calling these functions.
   This API is only available in SDL_mixer 1.2.9 and later.

   // usage...
   int i;
   const int total = Mix_GetNumChunkDecoders();
   for (i = 0; i < total; i++)
       printf("Supported chunk decoder: [%s]\n", Mix_GetChunkDecoder(i));

   Appearing in this list doesn't promise your specific audio file will
   decode...but it's handy to know if you have, say, a functioning Timidity
   install.

   These return values are static, read-only data; do not modify or free it.
   The pointers remain valid until you call Mix_CloseAudio().
*/
extern DECLSPEC int SDLCALL Mix_GetNumChunkDecoders(void);
extern DECLSPEC const char * SDLCALL Mix_GetChunkDecoder(int index);
extern DECLSPEC int SDLCALL Mix_GetNumMusicDecoders(void);
extern DECLSPEC const char * SDLCALL Mix_GetMusicDecoder(int index);

/* Find out the music format of a mixer music, or the currently playing
   music, if 'music' is NULL.
*/
extern DECLSPEC Mix_MusicType SDLCALL Mix_GetMusicType(const Mix_Music *music);

/* Set a function that is called after all mixing is performed.
   This can be used to provide real-time visual display of the audio stream
   or add a custom mixer filter for the stream data.
*/
extern DECLSPEC void SDLCALL Mix_SetPostMix(void (*mix_func)
                             (void *udata, Uint8 *stream, int len), void *arg);

/* Add your own music player or additional mixer function.
   If 'mix_func' is NULL, the default music player is re-enabled.
 */
extern DECLSPEC void SDLCALL Mix_HookMusic(void (*mix_func)
                          (void *udata, Uint8 *stream, int len), void *arg);

/* Add your own callback when the music has finished playing.
   This callback is only called if the music finishes naturally.
 */
extern DECLSPEC void SDLCALL Mix_HookMusicFinished(void (*music_finished)(void));

/* Get a pointer to the user data for the current music hook */
extern DECLSPEC void * SDLCALL Mix_GetMusicHookData(void);

/*
 * Add your own callback when a channel has finished playing. NULL
 *  to disable callback. The callback may be called from the mixer's audio 
 *  callback or it could be called as a result of Mix_HaltChannel(), etc.
 *  do not call SDL_LockAudio() from this callback; you will either be 
 *  inside the audio callback, or SDL_mixer will explicitly lock the audio
 *  before calling your callback.
 */
extern DECLSPEC void SDLCALL Mix_ChannelFinished(void (*channel_finished)(int channel));


/* Special Effects API by ryan c. gordon. (icculus@icculus.org) */

#define MIX_CHANNEL_POST  -2

/* This is the format of a special effect callback:
 *
 *   myeffect(int chan, void *stream, int len, void *udata);
 *
 * (chan) is the channel number that your effect is affecting. (stream) is
 *  the buffer of data to work upon. (len) is the size of (stream), and
 *  (udata) is a user-defined bit of data, which you pass as the last arg of
 *  Mix_RegisterEffect(), and is passed back unmolested to your callback.
 *  Your effect changes the contents of (stream) based on whatever parameters
 *  are significant, or just leaves it be, if you prefer. You can do whatever
 *  you like to the buffer, though, and it will continue in its changed state
 *  down the mixing pipeline, through any other effect functions, then finally
 *  to be mixed with the rest of the channels and music for the final output
 *  stream.
 *
 * DO NOT EVER call SDL_LockAudio() from your callback function!
 */
typedef void (*Mix_EffectFunc_t)(int chan, void *stream, int len, void *udata);

/*
 * This is a callback that signifies that a channel has finished all its
 *  loops and has completed playback. This gets called if the buffer
 *  plays out normally, or if you call Mix_HaltChannel(), implicitly stop
 *  a channel via Mix_AllocateChannels(), or unregister a callback while
 *  it's still playing.
 *
 * DO NOT EVER call SDL_LockAudio() from your callback function!
 */
typedef void (*Mix_EffectDone_t)(int chan, void *udata);


/* Register a special effect function. At mixing time, the channel data is
 *  copied into a buffer and passed through each registered effect function.
 *  After it passes through all the functions, it is mixed into the final
 *  output stream. The copy to buffer is performed once, then each effect
 *  function performs on the output of the previous effect. Understand that
 *  this extra copy to a buffer is not performed if there are no effects
 *  registered for a given chunk, which saves CPU cycles, and any given
 *  effect will be extra cycles, too, so it is crucial that your code run
 *  fast. Also note that the data that your function is given is in the
 *  format of the sound device, and not the format you gave to Mix_OpenAudio(),
 *  although they may in reality be the same. This is an unfortunate but
 *  necessary speed concern. Use Mix_QuerySpec() to determine if you can
 *  handle the data before you register your effect, and take appropriate
 *  actions.
 * You may also specify a callback (Mix_EffectDone_t) that is called when
 *  the channel finishes playing. This gives you a more fine-grained control
 *  than Mix_ChannelFinished(), in case you need to free effect-specific
 *  resources, etc. If you don't need this, you can specify NULL.
 * You may set the callbacks before or after calling Mix_PlayChannel().
 * Things like Mix_SetPanning() are just internal special effect functions,
 *  so if you are using that, you've already incurred the overhead of a copy
 *  to a separate buffer, and that these effects will be in the queue with
 *  any functions you've registered. The list of registered effects for a
 *  channel is reset when a chunk finishes playing, so you need to explicitly
 *  set them with each call to Mix_PlayChannel*().
 * You may also register a special effect function that is to be run after
 *  final mixing occurs. The rules for these callbacks are identical to those
 *  in Mix_RegisterEffect, but they are run after all the channels and the
 *  music have been mixed into a single stream, whereas channel-specific
 *  effects run on a given channel before any other mixing occurs. These
 *  global effect callbacks are call "posteffects". Posteffects only have
 *  their Mix_EffectDone_t function called when they are unregistered (since
 *  the main output stream is never "done" in the same sense as a channel).
 *  You must unregister them manually when you've had enough. Your callback
 *  will be told that the channel being mixed is (MIX_CHANNEL_POST) if the
 *  processing is considered a posteffect.
 *
 * After all these effects have finished processing, the callback registered
 *  through Mix_SetPostMix() runs, and then the stream goes to the audio
 *  device. 
 *
 * DO NOT EVER call SDL_LockAudio() from your callback function!
 *
 * returns zero if error (no such channel), nonzero if added.
 *  Error messages can be retrieved from Mix_GetError().
 */
extern DECLSPEC int SDLCALL Mix_RegisterEffect(int chan, Mix_EffectFunc_t f,
					Mix_EffectDone_t d, void *arg);


/* You may not need to call this explicitly, unless you need to stop an
 *  effect from processing in the middle of a chunk's playback.
 * Posteffects are never implicitly unregistered as they are for channels,
 *  but they may be explicitly unregistered through this function by
 *  specifying MIX_CHANNEL_POST for a channel.
 * returns zero if error (no such channel or effect), nonzero if removed.
 *  Error messages can be retrieved from Mix_GetError().
 */
extern DECLSPEC int SDLCALL Mix_UnregisterEffect(int channel, Mix_EffectFunc_t f);


/* You may not need to call this explicitly, unless you need to stop all
 *  effects from processing in the middle of a chunk's playback. Note that
 *  this will also shut off some internal effect processing, since
 *  Mix_SetPanning() and others may use this API under the hood. This is
 *  called internally when a channel completes playback.
 * Posteffects are never implicitly unregistered as they are for channels,
 *  but they may be explicitly unregistered through this function by
 *  specifying MIX_CHANNEL_POST for a channel.
 * returns zero if error (no such channel), nonzero if all effects removed.
 *  Error messages can be retrieved from Mix_GetError().
 */
extern DECLSPEC int SDLCALL Mix_UnregisterAllEffects(int channel);


#define MIX_EFFECTSMAXSPEED  "MIX_EFFECTSMAXSPEED"

/*
 * These are the internally-defined mixing effects. They use the same API that
 *  effects defined in the application use, but are provided here as a
 *  convenience. Some effects can reduce their quality or use more memory in
 *  the name of speed; to enable this, make sure the environment variable
 *  MIX_EFFECTSMAXSPEED (see above) is defined before you call
 *  Mix_OpenAudio().
 */


/* Set the panning of a channel. The left and right channels are specified
 *  as integers between 0 and 255, quietest to loudest, respectively.
 *
 * Technically, this is just individual volume control for a sample with
 *  two (stereo) channels, so it can be used for more than just panning.
 *  If you want real panning, call it like this:
 *
 *   Mix_SetPanning(channel, left, 255 - left);
 *
 * ...which isn't so hard.
 *
 * Setting (channel) to MIX_CHANNEL_POST registers this as a posteffect, and
 *  the panning will be done to the final mixed stream before passing it on
 *  to the audio device.
 *
 * This uses the Mix_RegisterEffect() API internally, and returns without
 *  registering the effect function if the audio device is not configured
 *  for stereo output. Setting both (left) and (right) to 255 causes this
 *  effect to be unregistered, since that is the data's normal state.
 *
 * returns zero if error (no such channel or Mix_RegisterEffect() fails),
 *  nonzero if panning effect enabled. Note that an audio device in mono
 *  mode is a no-op, but this call will return successful in that case.
 *  Error messages can be retrieved from Mix_GetError().
 */
extern DECLSPEC int SDLCALL Mix_SetPanning(int channel, Uint8 left, Uint8 right);


/* Set the position of a channel. (angle) is an integer from 0 to 360, that
 *  specifies the location of the sound in relation to the listener. (angle)
 *  will be reduced as neccesary (540 becomes 180 degrees, -100 becomes 260).
 *  Angle 0 is due north, and rotates clockwise as the value increases.
 *  For efficiency, the precision of this effect may be limited (angles 1
 *  through 7 might all produce the same effect, 8 through 15 are equal, etc).
 *  (distance) is an integer between 0 and 255 that specifies the space
 *  between the sound and the listener. The larger the number, the further
 *  away the sound is. Using 255 does not guarantee that the channel will be
 *  culled from the mixing process or be completely silent. For efficiency,
 *  the precision of this effect may be limited (distance 0 through 5 might
 *  all produce the same effect, 6 through 10 are equal, etc). Setting (angle)
 *  and (distance) to 0 unregisters this effect, since the data would be
 *  unchanged.
 *
 * If you need more precise positional audio, consider using OpenAL for
 *  spatialized effects instead of SDL_mixer. This is only meant to be a
 *  basic effect for simple "3D" games.
 *
 * If the audio device is configured for mono output, then you won't get
 *  any effectiveness from the angle; however, distance attenuation on the
 *  channel will still occur. While this effect will function with stereo
 *  voices, it makes more sense to use voices with only one channel of sound,
 *  so when they are mixed through this effect, the positioning will sound
 *  correct. You can convert them to mono through SDL before giving them to
 *  the mixer in the first place if you like.
 *
 * Setting (channel) to MIX_CHANNEL_POST registers this as a posteffect, and
 *  the positioning will be done to the final mixed stream before passing it
 *  on to the audio device.
 *
 * This is a convenience wrapper over Mix_SetDistance() and Mix_SetPanning().
 *
 * returns zero if error (no such channel or Mix_RegisterEffect() fails),
 *  nonzero if position effect is enabled.
 *  Error messages can be retrieved from Mix_GetError().
 */
extern DECLSPEC int SDLCALL Mix_SetPosition(int channel, Sint16 angle, Uint8 distance);


/* Set the "distance" of a channel. (distance) is an integer from 0 to 255
 *  that specifies the location of the sound in relation to the listener.
 *  Distance 0 is overlapping the listener, and 255 is as far away as possible
 *  A distance of 255 does not guarantee silence; in such a case, you might
 *  want to try changing the chunk's volume, or just cull the sample from the
 *  mixing process with Mix_HaltChannel().
 * For efficiency, the precision of this effect may be limited (distances 1
 *  through 7 might all produce the same effect, 8 through 15 are equal, etc).
 *  (distance) is an integer between 0 and 255 that specifies the space
 *  between the sound and the listener. The larger the number, the further
 *  away the sound is.
 * Setting (distance) to 0 unregisters this effect, since the data would be
 *  unchanged.
 * If you need more precise positional audio, consider using OpenAL for
 *  spatialized effects instead of SDL_mixer. This is only meant to be a
 *  basic effect for simple "3D" games.
 *
 * Setting (channel) to MIX_CHANNEL_POST registers this as a posteffect, and
 *  the distance attenuation will be done to the final mixed stream before
 *  passing it on to the audio device.
 *
 * This uses the Mix_RegisterEffect() API internally.
 *
 * returns zero if error (no such channel or Mix_RegisterEffect() fails),
 *  nonzero if position effect is enabled.
 *  Error messages can be retrieved from Mix_GetError().
 */
extern DECLSPEC int SDLCALL Mix_SetDistance(int channel, Uint8 distance);


/*
 * !!! FIXME : Haven't implemented, since the effect goes past the
 *              end of the sound buffer. Will have to think about this.
 *               --ryan.
 */
#if 0
/* Causes an echo effect to be mixed into a sound. (echo) is the amount
 *  of echo to mix. 0 is no echo, 255 is infinite (and probably not
 *  what you want).
 *
 * Setting (channel) to MIX_CHANNEL_POST registers this as a posteffect, and
 *  the reverbing will be done to the final mixed stream before passing it on
 *  to the audio device.
 *
 * This uses the Mix_RegisterEffect() API internally. If you specify an echo
 *  of zero, the effect is unregistered, as the data is already in that state.
 *
 * returns zero if error (no such channel or Mix_RegisterEffect() fails),
 *  nonzero if reversing effect is enabled.
 *  Error messages can be retrieved from Mix_GetError().
 */
extern no_parse_DECLSPEC int SDLCALL Mix_SetReverb(int channel, Uint8 echo);
#endif

/* Causes a channel to reverse its stereo. This is handy if the user has his
 *  speakers hooked up backwards, or you would like to have a minor bit of
 *  psychedelia in your sound code.  :)  Calling this function with (flip)
 *  set to non-zero reverses the chunks's usual channels. If (flip) is zero,
 *  the effect is unregistered.
 *
 * This uses the Mix_RegisterEffect() API internally, and thus is probably
 *  more CPU intensive than having the user just plug in his speakers
 *  correctly. Mix_SetReverseStereo() returns without registering the effect
 *  function if the audio device is not configured for stereo output.
 *
 * If you specify MIX_CHANNEL_POST for (channel), then this the effect is used
 *  on the final mixed stream before sending it on to the audio device (a
 *  posteffect).
 *
 * returns zero if error (no such channel or Mix_RegisterEffect() fails),
 *  nonzero if reversing effect is enabled. Note that an audio device in mono
 *  mode is a no-op, but this call will return successful in that case.
 *  Error messages can be retrieved from Mix_GetError().
 */
extern DECLSPEC int SDLCALL Mix_SetReverseStereo(int channel, int flip);

/* end of effects API. --ryan. */


/* Reserve the first channels (0 -> n-1) for the application, i.e. don't allocate
   them dynamically to the next sample if requested with a -1 value below.
   Returns the number of reserved channels.
 */
extern DECLSPEC int SDLCALL Mix_ReserveChannels(int num);

/* Channel grouping functions */

/* Attach a tag to a channel. A tag can be assigned to several mixer
   channels, to form groups of channels.
   If 'tag' is -1, the tag is removed (actually -1 is the tag used to
   represent the group of all the channels).
   Returns true if everything was OK.
 */
extern DECLSPEC int SDLCALL Mix_GroupChannel(int which, int tag);
/* Assign several consecutive channels to a group */
extern DECLSPEC int SDLCALL Mix_GroupChannels(int from, int to, int tag);
/* Finds the first available channel in a group of channels,
   returning -1 if none are available.
 */
extern DECLSPEC int SDLCALL Mix_GroupAvailable(int tag);
/* Returns the number of channels in a group. This is also a subtle
   way to get the total number of channels when 'tag' is -1
 */
extern DECLSPEC int SDLCALL Mix_GroupCount(int tag);
/* Finds the "oldest" sample playing in a group of channels */
extern DECLSPEC int SDLCALL Mix_GroupOldest(int tag);
/* Finds the "most recent" (i.e. last) sample playing in a group of channels */
extern DECLSPEC int SDLCALL Mix_GroupNewer(int tag);

/* Play an audio chunk on a specific channel.
   If the specified channel is -1, play on the first free channel.
   If 'loops' is greater than zero, loop the sound that many times.
   If 'loops' is -1, loop inifinitely (~65000 times).
   Returns which channel was used to play the sound.
*/
#define Mix_PlayChannel(channel,chunk,loops) Mix_PlayChannelTimed(channel,chunk,loops,-1)
/* The same as above, but the sound is played at most 'ticks' milliseconds */
extern DECLSPEC int SDLCALL Mix_PlayChannelTimed(int channel, Mix_Chunk *chunk, int loops, int ticks);
extern DECLSPEC int SDLCALL Mix_PlayMusic(Mix_Music *music, int loops);

/* Fade in music or a channel over "ms" milliseconds, same semantics as the "Play" functions */
extern DECLSPEC int SDLCALL Mix_FadeInMusic(Mix_Music *music, int loops, int ms);
extern DECLSPEC int SDLCALL Mix_FadeInMusicPos(Mix_Music *music, int loops, int ms, double position);
#define Mix_FadeInChannel(channel,chunk,loops,ms) Mix_FadeInChannelTimed(channel,chunk,loops,ms,-1)
extern DECLSPEC int SDLCALL Mix_FadeInChannelTimed(int channel, Mix_Chunk *chunk, int loops, int ms, int ticks);

/* Set the volume in the range of 0-128 of a specific channel or chunk.
   If the specified channel is -1, set volume for all channels.
   Returns the original volume.
   If the specified volume is -1, just return the current volume.
*/
extern DECLSPEC int SDLCALL Mix_Volume(int channel, int volume);
extern DECLSPEC int SDLCALL Mix_VolumeChunk(Mix_Chunk *chunk, int volume);
extern DECLSPEC int SDLCALL Mix_VolumeMusic(int volume);

/* Halt playing of a particular channel */
extern DECLSPEC int SDLCALL Mix_HaltChannel(int channel);
extern DECLSPEC int SDLCALL Mix_HaltGroup(int tag);
extern DECLSPEC int SDLCALL Mix_HaltMusic(void);

/* Change the expiration delay for a particular channel.
   The sample will stop playing after the 'ticks' milliseconds have elapsed,
   or remove the expiration if 'ticks' is -1
*/
extern DECLSPEC int SDLCALL Mix_ExpireChannel(int channel, int ticks);

/* Halt a channel, fading it out progressively till it's silent
   The ms parameter indicates the number of milliseconds the fading
   will take.
 */
extern DECLSPEC int SDLCALL Mix_FadeOutChannel(int which, int ms);
extern DECLSPEC int SDLCALL Mix_FadeOutGroup(int tag, int ms);
extern DECLSPEC int SDLCALL Mix_FadeOutMusic(int ms);

/* Query the fading status of a channel */
extern DECLSPEC Mix_Fading SDLCALL Mix_FadingMusic(void);
extern DECLSPEC Mix_Fading SDLCALL Mix_FadingChannel(int which);

/* Pause/Resume a particular channel */
extern DECLSPEC void SDLCALL Mix_Pause(int channel);
extern DECLSPEC void SDLCALL Mix_Resume(int channel);
extern DECLSPEC int SDLCALL Mix_Paused(int channel);

/* Pause/Resume the music stream */
extern DECLSPEC void SDLCALL Mix_PauseMusic(void);
extern DECLSPEC void SDLCALL Mix_ResumeMusic(void);
extern DECLSPEC void SDLCALL Mix_RewindMusic(void);
extern DECLSPEC int SDLCALL Mix_PausedMusic(void);

/* Set the current position in the music stream.
   This returns 0 if successful, or -1 if it failed or isn't implemented.
   This function is only implemented for MOD music formats (set pattern
   order number) and for OGG music (set position in seconds), at the
   moment.
*/
extern DECLSPEC int SDLCALL Mix_SetMusicPosition(double position);

/* Check the status of a specific channel.
   If the specified channel is -1, check all channels.
*/
extern DECLSPEC int SDLCALL Mix_Playing(int channel);
extern DECLSPEC int SDLCALL Mix_PlayingMusic(void);

/* Stop music and set external music playback command */
extern DECLSPEC int SDLCALL Mix_SetMusicCMD(const char *command);

/* Synchro value is set by MikMod from modules while playing */
extern DECLSPEC int SDLCALL Mix_SetSynchroValue(int value);
extern DECLSPEC int SDLCALL Mix_GetSynchroValue(void);

/* Get the Mix_Chunk currently associated with a mixer channel
    Returns NULL if it's an invalid channel, or there's no chunk associated.
*/
extern DECLSPEC Mix_Chunk * SDLCALL Mix_GetChunk(int channel);

/* Close the mixer, halting all playing audio */
extern DECLSPEC void SDLCALL Mix_CloseAudio(void);

/* We'll use SDL for reporting errors */
#define Mix_SetError	SDL_SetError
#define Mix_GetError	SDL_GetError

/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include "close_code.h"

#endif /* _SDL_MIXER_H */