/*                                                 RTAUDIO.C for DEC  */

/*  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"

#include "DECplay.h"   /* doesn't include record feature */

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               */
/*        rec_set(nchnls, dsize, esr, scale);  */
    die(Str(X_238,"DECaudio 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               */
    if ((b = O.outbufsamps / nchnls) >= 8192) {
      sprintf(errmsg, Str(X_137,"-b %d probably too large, suggest <= 2048"), b);
      warning(errmsg);
    }
    if (oMaxLag * esr / 11025 > 2048) {
      sprintf(errmsg, Str(X_97,"-B %d probably too large, suggest 1024"), oMaxLag);
      warning(errmsg);
    }
    play_set(nchnls, dsize, esr, scale);
    oshift = getshift(nchnls * dsize);
}

int rtrecord_(char *inbuf, int nbytes) /* get samples from ADC */
{
/*      rec_on(inbuf, (long)nbytes >> ishift);   */  /* not yet supported */
    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;
    while (get_playbuf_remains() > oMaxLag);  /* once lag is below threshold, */
    play_on(outbuf, sampframes);              /*    send these sample-frames  */
    nrecs++;
}

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

