cmixer.h

/*
** Copyright (c) 2017 rxi
**
** This library is free software; you can redistribute it and/or modify it
** under the terms of the MIT license. See `cmixer.c` for details.
**/

#ifndef CMIXER_H
#define CMIXER_H

#define CM_USE_STB_VORBIS
#define CM_VERSION "0.1.1"

#define BUFFER_SIZE       (512)
#define BUFFER_MASK       (BUFFER_SIZE - 1)


typedef short           cm_Int16;
typedef int             cm_Int32;
typedef long long       cm_Int64;
typedef unsigned char   cm_UInt8;
typedef unsigned short  cm_UInt16;
typedef unsigned        cm_UInt32;

typedef struct cm_Source cm_Source;





typedef struct {
  int type;
  void *udata;
  const char *msg;
  cm_Int16 *buffer;
  int length;
} cm_Event;

typedef void (*cm_EventHandler)(cm_Event *e);

typedef struct {
  cm_EventHandler handler;
  void *udata;
  int samplerate;
  int length;
} cm_SourceInfo;


enum {
  CM_STATE_STOPPED,
  CM_STATE_PLAYING,
  CM_STATE_PAUSED
};

enum {
  CM_EVENT_LOCK,
  CM_EVENT_UNLOCK,
  CM_EVENT_DESTROY,
  CM_EVENT_SAMPLES,
  CM_EVENT_REWIND
};


struct cm_Source {
  cm_Source *next;              /* Next source in list */
  cm_Int16 buffer[BUFFER_SIZE]; /* Internal buffer with raw stereo PCM */
  cm_EventHandler handler;      /* Event handler */
  void *udata;          /* Stream's udata (from cm_SourceInfo) */
  int samplerate;       /* Stream's native samplerate */
  int length;           /* Stream's length in frames */
  int end;              /* End index for the current play-through */
  int state;            /* Current state (playing|paused|stopped) */
  cm_Int64 position;    /* Current playhead position (fixed point) */
  int lgain, rgain;     /* Left and right gain (fixed point) */
  int rate;             /* Playback rate (fixed point) */
  int nextfill;         /* Next frame idx where the buffer needs to be filled */
  int loop;             /* Whether the source will loop when `end` is reached */
  int rewind;           /* Whether the source will rewind before playing */
  int active;           /* Whether the source is part of `sources` list */
  double gain;          /* Gain set by `cm_set_gain()` */
  double pan;           /* Pan set by `cm_set_pan()` */
  int channel;			/* the channel associated with this source */
  void (*finished_cb)(int); /* Callback for when the source has finished (only called for non-looping sources) */
  // (LS):
  int fade;
  double gain0;
  double gainf;
  double fade_t0;
  double fade_T;
  cm_Int16 xl[2],xr[2],x0l,x0r;
  cm_Int16 yl[2],yr[2],y0l,y0r;
  double a1,a2,b0,b1,b2;
};

const char* cm_get_error(void);
void cm_init(int samplerate);
void cm_set_lock(cm_EventHandler lock);
void cm_set_time_function(double (time_function)(void));
void cm_set_master_gain(double gain);
void cm_process(cm_Int16 *dst, int len);

cm_Source* cm_new_source(const cm_SourceInfo *info);
cm_Source* cm_new_source_from_file(const char *filename);
cm_Source* cm_new_source_from_mem(void *data, int size);
void cm_destroy_source(cm_Source *src);
double cm_get_length(cm_Source *src);
double cm_get_position(cm_Source *src);
int cm_get_state(cm_Source *src);
void cm_set_gain(cm_Source *src, double gain);
void cm_set_pan(cm_Source *src, double pan);
void cm_set_pitch(cm_Source *src, double pitch);
void cm_set_iir(cm_Source *src, double b0, double b1, double b2, double a1, double a2); // (LS)
void cm_set_master_iir(double b0, double b1, double b2, double a1, double a2); // (LS)
void cm_set_loop(cm_Source *src, int loop);
void cm_play(cm_Source *src);
void cm_pause(cm_Source *src);
void cm_stop(cm_Source *src);

#endif