-   
- #ifndef BACKEND_H 
- #define BACKEND_H 
-   
- #include "s3_defs.h" 
-   
- typedef enum tAudioBackend_error_code { 
-     eAB_success = 0, 
-     eAB_error = 1 
- } tAudioBackend_error_code; 
-   
- tAudioBackend_error_code AudioBackend_Init(void); 
- tAudioBackend_error_code AudioBackend_InitCDA(void); 
- void AudioBackend_UnInit(void); 
- void AudioBackend_UnInitCDA(void); 
- void* AudioBackend_AllocateSampleTypeStruct(void); 
-   
- // returns 1 if playing, otherwise 0 
- int AudioBackend_SoundIsPlaying(tS3_channel* chan); 
- tAudioBackend_error_code AudioBackend_StopSample(tS3_channel* chan); 
- tAudioBackend_error_code AudioBackend_PlaySample(tS3_channel* chan); 
- tAudioBackend_error_code AudioBackend_SetVolume(tS3_channel* chan, int volume); 
- tAudioBackend_error_code AudioBackend_SetPan(tS3_channel* chan, int pan); 
- tAudioBackend_error_code AudioBackend_SetFrequency(tS3_channel* chan, int rate); 
-   
- #endif 
-