/*

    SDL_mixer:  An audio mixer library based on the SDL library

    Copyright (C) 1997-2004 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: SDL_mixer.h,v 1.30 2004/01/04 17:37:04 slouken Exp $ */

#ifndef _SDL_MIXER_H

#define _SDL_MIXER_H

#include "SDL_types.h"

#include "SDL_rwops.h"

#include "SDL_audio.h"

#include "SDL_byteorder.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	6

/* 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 {

	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

} 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);

#ifdef USE_RWOPS /* This hasn't been hooked into music.c yet */

/* Load a music file from an SDL_RWop object (MikMod-specific currently)

   Matt Campbell (matt@campbellhome.dhs.org) April 2000 */

extern DECLSPEC Mix_Music * SDLCALL Mix_LoadMUS_RW(SDL_RWops *rw);

#endif

/* 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);

/* 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@linuxgames.com) */

#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);