/**
* Mix some frames from the given secondary buffer "dsb" into the device
* primary buffer.
*
* dsb = the secondary buffer
* playpos = the current play position in the device buffer (primary buffer)
* writepos = the current safe-to-write position in the device buffer
* mixlen = the maximum number of bytes in the primary buffer to mix, from the
* current writepos.
*
* Returns: the number of bytes beyond the writepos that were mixed.
*/
static DWORD DSOUND_MixOne(IDirectSoundBufferImpl *dsb, DWORD writepos, DWORD mixlen)
{
DWORD primary_done = 0;
TRACE("(%p,%d,%d)\n",dsb,writepos,mixlen);
TRACE("writepos=%d, mixlen=%d\n", writepos, mixlen);
TRACE("looping=%d, leadin=%d\n", dsb->playflags, dsb->leadin);
/* If leading in, only mix about 20 ms, and 'skip' mixing the rest, for more fluid pointer advancement */
/* FIXME: Is this needed? */
if (dsb->leadin && dsb->state == STATE_STARTING) {
if (mixlen > 2 * dsb->device->fraglen) {
primary_done = mixlen - 2 * dsb->device->fraglen;
mixlen = 2 * dsb->device->fraglen;
writepos += primary_done;
dsb->sec_mixpos += (primary_done / dsb->device->pwfx->nBlockAlign) *
dsb->pwfx->nBlockAlign * dsb->freqAdjust;
}
}
dsb->leadin = FALSE;
TRACE("mixlen (primary) = %i\n", mixlen);
/* First try to mix to the end of the buffer if possible
* Theoretically it would allow for better optimization
*/
primary_done += DSOUND_MixInBuffer(dsb, writepos, mixlen);
TRACE("total mixed data=%d\n", primary_done);
/* Report back the total prebuffered amount for this buffer */
return primary_done;
}
/**
* Mix some frames from the given secondary buffer "dsb" into the device
* primary buffer.
*
* dsb = the secondary buffer
* playpos = the current play position in the device buffer (primary buffer)
* writepos = the current safe-to-write position in the device buffer
* mixlen = the maximum number of bytes in the primary buffer to mix, from the
* current writepos.
*
* Returns: the number of bytes beyond the writepos that were mixed.
*/
static DWORD DSOUND_MixOne(IDirectSoundBufferImpl *dsb, DWORD writepos, DWORD mixlen)
{
/* The buffer's primary_mixpos may be before or after the device
* buffer's mixpos, but both must be ahead of writepos. */
DWORD primary_done;
TRACE("(%p,%d,%d)\n",dsb,writepos,mixlen);
TRACE("writepos=%d, primary_mixpos=%d, mixlen=%d\n", writepos, dsb->primary_mixpos, mixlen);
TRACE("looping=%d, leadin=%d\n", dsb->playflags, dsb->leadin);
/* If leading in, only mix about 20 ms, and 'skip' mixing the rest, for more fluid pointer advancement */
if (dsb->leadin && dsb->state == STATE_STARTING)
{
if (mixlen > 2 * dsb->device->fraglen)
{
dsb->primary_mixpos += mixlen - 2 * dsb->device->fraglen;
dsb->primary_mixpos %= dsb->device->buflen;
}
}
dsb->leadin = FALSE;
/* calculate how much pre-buffering has already been done for this buffer */
primary_done = DSOUND_BufPtrDiff(dsb->device->buflen, dsb->primary_mixpos, writepos);
/* sanity */
if(mixlen < primary_done)
{
/* Should *NEVER* happen */
ERR("Fatal error. Under/Overflow? primary_done=%d, mixpos=%d/%d, primary_mixpos=%d, writepos=%d, mixlen=%d\n", primary_done,dsb->sec_mixpos, dsb->buflen, dsb->primary_mixpos, writepos, mixlen);
dsb->primary_mixpos = writepos + mixlen;
dsb->primary_mixpos %= dsb->device->buflen;
return mixlen;
}
/* take into account already mixed data */
mixlen -= primary_done;
TRACE("primary_done=%d, mixlen (primary) = %i\n", primary_done, mixlen);
if (!mixlen)
return primary_done;
/* First try to mix to the end of the buffer if possible
* Theoretically it would allow for better optimization
*/
DSOUND_MixInBuffer(dsb, dsb->primary_mixpos, mixlen);
/* re-calculate the primary done */
primary_done = DSOUND_BufPtrDiff(dsb->device->buflen, dsb->primary_mixpos, writepos);
TRACE("new primary_mixpos=%d, total mixed data=%d\n", dsb->primary_mixpos, primary_done);
/* Report back the total prebuffered amount for this buffer */
return primary_done;
}