27     char   openal_init              (char* programname, char usehardware, unsigned int memorysize);

    27     // init audio context and allocate memory

    28     char   openal_close             (void);

    28     char openal_init              (char usehardware, int memorysize);

    29     char   openal_ready             (void);

    29 

    30     int    openal_loadfile          (const char *filename);

    30     // close audio subsytem and free memory

    31     char   openal_toggleloop        (unsigned int index);

    31     void openal_close             (void);

    32     char   openal_setposition       (unsigned int index, float x, float y, float z);

    32 

    33     char   openal_setvolume         (unsigned int index, unsigned char percentage);

    33     // check if openal_init has been called

    34     char   openal_setglobalvolume   (unsigned char percentage);

    34     char openal_ready             (void);

    35     char   openal_togglemute        (void);

    35 

    36     char   openal_fadeout           (unsigned int index, unsigned short int quantity);

    36     // load an audio file into memory and map it to abuffer

    37     char   openal_fadein            (unsigned int index, unsigned short int quantity);

    37     int  openal_loadfile          (const char *filename);

    38     char   openal_fade              (unsigned int index, unsigned short int quantity, char direction);

    38 

    39     char   openal_playsound         (unsigned int index);	

    39     // play, pause, stop a single sound source

    40     char   openal_pausesound        (unsigned int index);

    40     void openal_playsound         (unsigned int index);	

    41     char   openal_stopsound         (unsigned int index);

    41     void openal_pausesound        (unsigned int index);

    42     char   openal_freesound         (unsigned int index);

    42     void openal_stopsound         (unsigned int index);

    43     

    43 

    44     // play a sound and set whether it should loop or not (0/1)

    45     void openal_playsound_loop    (unsigned int index, char loops);

    46 

    47     // stop a sound and free the associated buffer

    48     void openal_stopsound_free    (unsigned int index, char freesource);

    49 

    50     void openal_freesound         (unsigned int index);

    51 

    52     // set or unset the looping property for a sound source

    53     void openal_toggleloop        (unsigned int index);

    54 

    55     // set position and volume of a sound source

    56     void openal_setposition       (unsigned int index, float x, float y, float z);

    57     void openal_setvolume         (unsigned int index, float gain);

    58 

    59     // set volume for all sounds (gain interval is [0-1])

    60     void openal_setglobalvolume   (float gain);

    61 

    62     // mute or unmute all sounds    

    63     void openal_togglemute        (void);

    64 

    65     // fade effect, 

    66     void openal_fadeout           (unsigned int index, unsigned short int quantity);

    67     void openal_fadein            (unsigned int index, unsigned short int quantity);

    68     void openal_fade              (unsigned int index, unsigned short int quantity, char direction);

    69 

    70 #define AL_FADE_IN 1

    71 #define AL_FADE_OUT -1

    72