/*

MIXERLIB: An audio mixer library based on the SDL library

Copyright (C) 1997-1999 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

5635-34 Springhouse Dr.

Pleasanton, CA 94588 (USA)

slouken@devolution.com

*/

#ifndef _MIXER_H_

#define _MIXER_H_

#include <SDL/SDL_types.h>

#include <SDL/SDL_rwops.h>

#include <SDL/SDL_audio.h>

#include <SDL/begin_code.h>

/* Set up for C function definitions, even when using C++ */

#ifdef __cplusplus

extern "C" {

#endif

/* 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

#define MIX_DEFAULT_FORMAT AUDIO_S16

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

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

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

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

extern Mix_Music *Mix_LoadMUS(const char *file);

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

extern Mix_Chunk *Mix_QuickLoad_WAV(Uint8 *mem);

/* Free an audio chunk previously loaded */

extern void Mix_FreeChunk(Mix_Chunk *chunk);

extern void Mix_FreeMusic(Mix_Music *music);

/* Add your own music player or additional mixer function.

If 'mix_func' is NULL, the default music player is re-enabled.

*/

extern void Mix_HookMusic(void (*mix_func)(void *udata, Uint8 *stream, int len),

void *arg);

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

extern void *Mix_GetMusicHookData(void);

/* 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 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 int Mix_GroupChannel(int which, int tag);

/* Assign several consecutive channels to a group */

extern int Mix_GroupChannels(int from, int to, int tag);

/* Finds the first available channel in a group of channels */

extern 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 int Mix_GroupCount(int tag);

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

extern int Mix_GroupOldest(int tag);

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

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

extern int Mix_PlayMusic(Mix_Music *music, int loops);

/* Fade in music or a channel over "ms" milliseconds, same semantics as the "Play" functions */

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

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

extern int Mix_FadeInChannelTimed(int channel, Mix_Chunk *chunk, int loops, int ms, int ticks);

/* Fades out the currently playing music, and progressively fades in a new music,

all in the background. The 'ms' period is half for fading out the music and

fading in the new one */

extern int Mix_FadeOutInMusic(Mix_Music *music, int loops, int ms);

/* 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 int Mix_Volume(int channel, int volume);

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

extern int Mix_VolumeMusic(int volume);

/* Halt playing of a particular channel */

extern int Mix_HaltChannel(int channel);

extern int Mix_HaltGroup(int tag);

extern 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 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 int Mix_FadeOutChannel(int which, int ms);

extern int Mix_FadeOutGroup(int tag, int ms);

extern int Mix_FadeOutMusic(int ms);

/* Query the fading status of a channel */

extern Mix_Fading Mix_FadingMusic(void);

extern Mix_Fading Mix_FadingChannel(int which);

/* Pause/Resume a particular channel */

extern void Mix_Pause(int channel);

extern void Mix_Resume(int channel);

/* Pause/Resume the music stream */

extern void Mix_PauseMusic(void);

extern void Mix_ResumeMusic(void);

extern void Mix_RewindMusic(void);

/* Check the status of a specific channel.

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

*/

extern int Mix_Playing(int channel);

extern int Mix_PlayingMusic(void);

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

extern int Mix_SetMusicCMD(const char *command);

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

extern 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 <SDL/close_code.h>

#endif /* _MIXER_H_ */