/*

SDL_mixer: An audio mixer library based on the SDL library

Copyright (C) 1997, 1998, 1999, 2000, 2001 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 _MIXER_H_

#define _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 MIX_MAJOR_VERSION 1

#define MIX_MINOR_VERSION 2

#define MIX_PATCHLEVEL 2

/* This macro can be used to fill a version structure with the compile-time

* version of the SDL_mixer library.

*/

#define MIX_VERSION(X) \

{ \

(X)->major = MIX_MAJOR_VERSION; \

(X)->minor = MIX_MINOR_VERSION; \

(X)->patch = MIX_PATCHLEVEL; \

}

/* 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 MIX_VERSION() macro.

*/

extern DECLSPEC const SDL_version * 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;

/* 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 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 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 Mix_QuerySpec(int *frequency,Uint16 *format,int *channels);

/* Load a wave file or a music (.mod .s3m .it .xm) file */

extern DECLSPEC Mix_Chunk *Mix_LoadWAV_RW(SDL_RWops *src, int freesrc);

#define Mix_LoadWAV(file) Mix_LoadWAV_RW(SDL_RWFromFile(file, "rb"), 1)

extern DECLSPEC Mix_Music *Mix_LoadMUS(const char *file);

#if 0 /* 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 no_parse_DECLSPEC Mix_Music *Mix_LoadMUS_RW(SDL_RWops *rw);

#endif

/* Load a wave file of the mixer format from a memory buffer */

extern DECLSPEC Mix_Chunk *Mix_QuickLoad_WAV(Uint8 *mem);

/* Free an audio chunk previously loaded */

extern DECLSPEC void Mix_FreeChunk(Mix_Chunk *chunk);

extern DECLSPEC void Mix_FreeMusic(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 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 Mix_HookMusic(void (*mix_func)

(void *udata, Uint8 *stream, int len), void *arg);

/* Add your own callback when the music has finished playing.

*/

extern DECLSPEC void Mix_HookMusicFinished(void (*music_finished)(void));

/* Get a pointer to the user data for the current music hook */

extern DECLSPEC void *Mix_GetMusicHookData(void);

/* Add your own callback when a channel has finished playing. NULL

* to disable callback.

*/

extern DECLSPEC void 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.

*/

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.

*/

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.

*

* returns zero if error (no such channel), nonzero if added.

* Error messages can be retrieved from Mix_GetError().

*/

extern DECLSPEC int 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 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 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 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 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 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 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 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 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 Mix_GroupChannel(int which, int tag);

/* Assign several consecutive channels to a group */

extern DECLSPEC int 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 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 Mix_GroupCount(int tag);

/* Finds the "oldest" sample playing in a group of channels */

extern DECLSPEC int Mix_GroupOldest(int tag);

/* Finds the "most recent" (i.e. last) sample playing in a group of channels */

extern DECLSPEC int 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 Mix_PlayChannelTimed(int channel, Mix_Chunk *chunk, int loops, int ticks);

extern DECLSPEC int 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 Mix_FadeInMusic(Mix_Music *music, int loops, int ms);

extern DECLSPEC int Mix_FadeInMusicPos(Mix_Music *music, int loops, int ms, int position);

#define Mix_FadeInChannel(channel,chunk,loops,ms) Mix_FadeInChannelTimed(channel,chunk,loops,ms,-1)

extern DECLSPEC int 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 Mix_Volume(int channel, int volume);

extern DECLSPEC int Mix_VolumeChunk(Mix_Chunk *chunk, int volume);

extern DECLSPEC int Mix_VolumeMusic(int volume);

/* Halt playing of a particular channel */

extern DECLSPEC int Mix_HaltChannel(int channel);

extern DECLSPEC int Mix_HaltGroup(int tag);

extern DECLSPEC int 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 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 Mix_FadeOutChannel(int which, int ms);

extern DECLSPEC int Mix_FadeOutGroup(int tag, int ms);

extern DECLSPEC int Mix_FadeOutMusic(int ms);

/* Query the fading status of a channel */

extern DECLSPEC Mix_Fading Mix_FadingMusic(void);

extern DECLSPEC Mix_Fading Mix_FadingChannel(int which);

/* Pause/Resume a particular channel */

extern DECLSPEC void Mix_Pause(int channel);

extern DECLSPEC void Mix_Resume(int channel);

extern DECLSPEC int Mix_Paused(int channel);

/* Pause/Resume the music stream */

extern DECLSPEC void Mix_PauseMusic(void);

extern DECLSPEC void Mix_ResumeMusic(void);

extern DECLSPEC void Mix_RewindMusic(void);

extern DECLSPEC int 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 at the moment.

*/

extern DECLSPEC int Mix_SetMusicPosition(int position);

/* Check the status of a specific channel.

If the specified channel is -1, check all channels.

*/

extern DECLSPEC int Mix_Playing(int channel);

extern DECLSPEC int Mix_PlayingMusic(void);

/* Stop music and set external music playback command */

extern DECLSPEC int Mix_SetMusicCMD(const char *command);

/* Synchro value is set by MikMod from modules while playing */

extern DECLSPEC int Mix_SetSynchroValue(int value);

extern DECLSPEC int 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 *Mix_GetChunk(int channel);

/* Close the mixer, halting all playing audio */

extern DECLSPEC void 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 /* _MIXER_H_ */

/* end of SDL_mixer.h ... */