kit_kmixer.h as of 8-18-23

/**
 * \file kit_kmixer.h
 * \brief Header file for KIT SDL2's KMixer module
 */
#ifndef _KIT_KMIXER_H
#define _KIT_KMIXER_H
#ifndef _KIT_SDL2_KMIXER_H
#define _KIT_SDL2_KMIXER_H


//#include <SDL2/SDL.h>
#include "./kit_core.h"



/* +kit_kmixer+ */
extern int kit_kmixerInit(int deviceThreadPoolSize);
extern int kit_kmixerQuit();
/* -kit_kmixer- */


/* +kit_kmixerVoice+ */
/**
 * PCM Audio Voice Callback
 * This type of function is called when added as a voice to a KMixer audio device.
 * Unless it's a capture (recording) type, you can add multiple voices or returns to a KMixer device.
 * While each voice's callback is given its own threadpool task (and should be thread-safe),
 * the overall speed is determined by device's slowest voice or return chain (processing-wise).
 * For a capture-type device, the given audio buffer must be completely read before returning.
 * For a rendering (playback) device, the buffer must be completely filled before returning.
 * \param[in] userdata A user-defined pointer passed to the voice callback.
 * \param[in] _stream  A pointer to the audio data buffer.
 * \param[in] len      The length of that buffer in samples (number of sample *frames* is len/<# of channels>).
 */
typedef void (*kit_kmixerVoiceCallback) (void* userdata, void* _stream, int len);
/* -kit_kmixerVoice- */



/* +kit_kmixerDevice+ */
/**
 * \brief This struct contains all info related to a an audio device and its voice chain
 */
typedef struct {
  union {
    char           str[8]; ///< \brief String portion of struct ID ("kmxrDev\x00").
    Uint64            num; ///< \brief Integer portion of struct ID (0x0076654472786D6B).
  } /* ---------- */ _magic; ///< \brief Struct ID number; union of Uint64 and char[8].
  SDL_AudioSpec        spec; ///< \brief Audio specification of the device.
  SDL_mutex*          _lock; ///< \brief Mutex for device access (lock unnecessary for accessing some members).
  struct {
    SDL_cond*        cond; ///< \brief < TBD >
    kit_coreVector* queue; ///< \brief Circular buffer that contains currently queued voice tasks.
    kit_coreVector*  pool; ///< \brief The thread pool for voice tasks
  } /* --------- */ _thread; ///< \brief The device's thread pool voice task queue.
  struct {
    kit_coreVector*   raw; ///< \brief 1D array of all registered voices and their information.
    kit_coreVector*   ord; ///< \brief 2D array of voices and their info, ordered by number of input voices.
  } /* --------- */ _voices; ///< \brief The device's registered voices
  SDL_AudioDeviceID  _devID; ///< \brief The device ID number that SDL uses.
} kit_kmixerDevice;
/* -kit_kmixerDevice- */



#endif /* _KIT_SDL2_KMIXER_H */
#endif /* _KIT_KMIXER_H */