_kit_kmixerPrivate.h as of 2023-8-24

#ifndef _KIT_KMIXERPRIVATE_H
#define _KIT_KMIXERPRIVATE_H




struct _kit_kmixerGlobals_t {
  SDL_mutex* lock;
  int threadPoolSize, cores, capabilities;
  int init;
};
extern struct _kit_kmixerGlobals_t _kit_kmixerGlobals;




typedef union {
  void*   ptr;
  Uint8*  u_8;
  Sint16* i16;
  Sint32* i32;
  float*  f32;
} _mono_samples;



//(stores left and right ear components of a stereo stream)
typedef struct { Uint8  l,r; } _stereo_samples_u_8;
typedef struct { Sint16 l,r; } _stereo_samples_i16;
typedef struct { Sint32 l,r; } _stereo_samples_i32;
typedef struct { float  l,r; } _stereo_samples_f32;


typedef union {
  void*                ptr;
  _stereo_samples_u_8* u_8;
  _stereo_samples_i16* i16;
  _stereo_samples_i32* i32;
  _stereo_samples_f32* f32;
} _stereo_samples;



typedef union {
  void*           v;
  _mono_samples   m;
  _stereo_samples s;
} _kit_kmixerVoiceBuffer;



typedef union {
  void*                v;
  float*               m;
  _stereo_samples_f32* s;
} _kit_kmixerVoiceBufferF;



typedef struct {
  _kit_kmixerVoiceBufferF   bufferInput; //input buffer (or the mixing stage's output)
  _kit_kmixerVoiceBufferF    bufferType; //output of type conversion to f32 (always stereo size)
  _kit_kmixerVoiceBufferF bufferChannel; //output of mono-stereo or stereo-mono conversion (always stereo size)
  _kit_kmixerVoiceBuffer     bufferUser; //buffer to be filled in or modified by user
  _kit_kmixerVoiceBufferF  bufferOutput; //final output buffer (or the mixing stage's input)

  SDL_mutex*                  lock; //to make sure a voice doesn't get deleted while it's processing
  kit_kmixerVoiceCallback callback; //user-implemented callback for processing audio data
  void*                   userdata; //user-defined pointer to be passed to the kit_kmixerVoiceCallback
  kit_coreVector*           inputs; //indexes of input voices, if any (can be NULL)

  Uint32                _padding32; //for padding to a multiple of 8 bytes
  Uint32                     index; //index of this specific voice in the device's voice list
  Uint32                sampleRate; //samples per second, in Hz
  Uint32           bufferUser_size; //size of inBuffer, in bytes

  //volume can actually be <0, but for volL it will override applyVolume to SDL_FALSE,
   //and for volR, volR would then be set to volL
  float                       volL; //left ear volume (or total volume if mono); 0.0 -> 1.0
  float                       volR; //right ear volume (ignored if mono); 0.0 -> 1.0

  SDL_bool             applyVolume; //if SDL_TRUE, apply volume when mixing voice's output
  SDL_bool             stereoInput; //input is mono if SDL_FALSE, stereo if SDL_TRUE
  SDL_bool              stereoUser; //voice is mono if SDL_FALSE, stereo if SDL_TRUE
  SDL_bool            stereoOutput; //output is mono if SDL_FALSE, stereo if SDL_TRUE

  Uint16              sampleFrames; //number of sample frames in the audio stream
  SDL_AudioFormat      formatInput; //data type of input buffer
  SDL_AudioFormat       formatUser; //data type of voice (user) buffer
  SDL_AudioFormat     formatOutput; //data type of output buffer

  //Uint16                _padding16; //for padding to a multiple of 8 bytes
} /*__attribute__((packed))*/ _kit_kmixerVoice;




extern int _kit_kmixerVoiceProc(void* data);


extern void _kit_kmixerVoiceMix(_kit_kmixerVoice* ovoice,
                                _kit_kmixerVoice* ivoices, Uint32 ivoices_len);



#endif