/*                                                   RTAUDIO.C for HP  */

/*  This module is included when RTAUDIO is defined at compile time.
    It provides an interface between Csound realtime record/play calls
    and the device-driver code that controls the actual hardware.
 */

#include "cs.h"
#include "soundio.h"

void AWopen(), AudioWrite(), AWclose(void);

static  int     ishift = 0, oshift = 0, oMaxLag;
extern  OPARMS  O;

static int getshift(int dsize)  /* turn sample- or frame-size into shiftsize */
{
    switch(dsize) {
    case 1:  return(0);
    case 2:  return(1);
    case 4:  return(2);
    case 8:  return(3);
    default: die(Str(X_1169,"rtaudio: illegal dsize"));
      return(-1);           /* Not reached */
    }
}

void recopen_(int nchnls, int dsize, float esr, int scale)
                                /* open for audio input */
{
    oMaxLag = O.oMaxLag;        /* import DAC setting from command line   */
    if (oMaxLag <= 0)           /* if DAC sampframes ndef in command line */
      oMaxLag = IODACSAMPS;     /*    use the default value               */
    die(Str(X_292,"HP audio record not available"));
    ishift = getshift(dsize);
}

void playopen_(int nchnls, int dsize, float esr, int scale)
                                /* open for audio output */
{
    int b = 0;

    oMaxLag = O.oMaxLag;        /* import DAC setting from command line   */
    if (oMaxLag <= 0)           /* if DAC sampframes ndef in command line */
      oMaxLag = IODACSAMPS;   /*    use the default value               */
    AWopen(nchnls, (long)esr, oMaxLag);
/*      if ((audiofd = open("/dev/audio", O_WRONLY)) < 0)
        die(X_1188,"sfinit: cannot open /dev/audio");  */
    oshift = getshift(nchnls * dsize);
}

int rtrecord_(char *inbuf, int nbytes) /* get samples from ADC */
{
    return(nbytes);
}

void rtplay_(char *outbuf, int nbytes) /* put samples to DAC  */
    /* N.B. This routine serves as a THROTTLE in Csound Realtime Performance, */
    /* delaying the actual writes and return until the hardware output buffer */
    /* passes a sample-specific THRESHOLD.  If the I/O BLOCKING functionality */
    /* is implemented ACCURATELY by the vendor-supplied audio-library write,  */
    /* that is sufficient.  Otherwise, requires some kind of IOCTL from here. */
    /* This functionality is IMPORTANT when other realtime I/O is occurring,  */
    /* such as when external MIDI data is being collected from a serial port. */
    /* Since Csound polls for MIDI input at the software synthesis K-rate     */
    /* (the resolution of all software-synthesized events), the user can      */
    /* eliminate MIDI jitter by requesting that both be made synchronous with */
    /* the above audio I/O blocks, i.e. by setting -b to some 1 or 2 K-prds.  */
{
    long sampframes = nbytes >> oshift;
    AudioWrite(outbuf, nbytes);
    /*  should synchcronize with buffer writes here by a wait loop */
    /*      do {
            if (ioctl(audiofd, AUDIO_GETINFO, &audinfo) < 0)
            die(X_175,"/dev/audio: cannot do AUDIO_GETINFO");
            } while (sampcnt - audinfo.play.samples > oMaxLag);
    */
    nrecs++;
}

void rtclose_(void)              /* close the I/O device entirely  */
{                               /* called only when both complete */
    AWclose();
    if (O.Linein) {
#ifdef PIPES
      if (O.Linename[0]=='|') _pclose(Linepipe);
      else
#endif
        if (strcmp(O.Linename, "stdin")!=0) close(Linefd);
    }
}

