void UPD7759StartWrite(UINT8 Data)
{
UINT8 Oldstart = Chip->start;
Chip->start = (Data != 0);
if (Chip->state == STATE_IDLE && !Oldstart && Chip->start && Chip->reset) {
Chip->state = STATE_START;
if (SlaveMode) UPD7759SlaveModeUpdate();
}
}
void UPD7759Update(int chip, short *pSoundBuf, int nLength)
{
Chip = Chips[chip];
INT32 ClocksLeft = Chip->clocks_left;
INT16 Sample = Chip->sample;
UINT32 Step = Chip->step;
UINT32 Pos = Chip->pos;
/* loop until done */
if (Chip->state != STATE_IDLE)
while (nLength != 0)
{
/* store the current sample */
pSoundBuf[0] += Sample << 7;
pSoundBuf[1] += Sample << 7;
pSoundBuf += 2;
nLength--;
/* advance by the number of clocks/output sample */
Pos += Step;
/* handle clocks, but only in standalone mode */
while (Chip->rom && Pos >= FRAC_ONE)
{
int ClocksThisTime = Pos >> FRAC_BITS;
if (ClocksThisTime > ClocksLeft)
ClocksThisTime = ClocksLeft;
/* clock once */
Pos -= ClocksThisTime * FRAC_ONE;
ClocksLeft -= ClocksThisTime;
/* if we're out of clocks, time to handle the next state */
if (ClocksLeft == 0)
{
/* advance one state; if we hit idle, bail */
UPD7759AdvanceState();
if (Chip->state == STATE_IDLE)
break;
/* reimport the variables that we cached */
ClocksLeft = Chip->clocks_left;
Sample = Chip->sample;
}
}
}
if (SlaveMode && ClocksLeft > 0) UPD7759SlaveModeUpdate();
Chip->clocks_left = ClocksLeft;
Chip->pos = Pos;
}
void UPD7759StartWrite(INT32 chip, UINT8 Data)
{
#if defined FBA_DEBUG
if (!DebugSnd_UPD7759Initted) bprintf(PRINT_ERROR, _T("UPD7759StartWrite called without init\n"));
if (chip > nNumChips) bprintf(PRINT_ERROR, _T("UPD7759StartWrite called with invalid chip %x\n"), chip);
#endif
Chip = Chips[chip];
UINT8 Oldstart = Chip->start;
Chip->start = (Data != 0);
if (Chip->state == STATE_IDLE && !Oldstart && Chip->start && Chip->reset) {
Chip->state = STATE_START;
if (SlaveMode) UPD7759SlaveModeUpdate();
}
}
void UPD7759Update(INT32 chip, INT16 *pSoundBuf, INT32 nLength)
{
#if defined FBA_DEBUG
if (!DebugSnd_UPD7759Initted) bprintf(PRINT_ERROR, _T("UPD7759Update called without init\n"));
if (chip > nNumChips) bprintf(PRINT_ERROR, _T("UPD7759Update called with invalid chip %x\n"), chip);
#endif
Chip = Chips[chip];
INT32 ClocksLeft = Chip->clocks_left;
INT16 Sample = Chip->sample;
UINT32 Step = Chip->step;
UINT32 Pos = Chip->pos;
/* loop until done */
if (Chip->state != STATE_IDLE)
while (nLength != 0)
{
/* store the current sample */
INT32 nLeftSample = 0;
INT32 nRightSample = 0;
if ((Chip->output_dir & BURN_SND_ROUTE_LEFT) == BURN_SND_ROUTE_LEFT) {
nLeftSample += (INT32)((Sample << 7) * Chip->volume);
}
if ((Chip->output_dir & BURN_SND_ROUTE_RIGHT) == BURN_SND_ROUTE_RIGHT) {
nRightSample += (INT32)((Sample << 7) * Chip->volume);
}
nLeftSample = BURN_SND_CLIP(nLeftSample);
nRightSample = BURN_SND_CLIP(nRightSample);
pSoundBuf[0] += nLeftSample;
pSoundBuf[1] += nRightSample;
pSoundBuf += 2;
nLength--;
/* advance by the number of clocks/output sample */
Pos += Step;
/* handle clocks, but only in standalone mode */
while (Chip->rom && Pos >= FRAC_ONE)
{
INT32 ClocksThisTime = Pos >> FRAC_BITS;
if (ClocksThisTime > ClocksLeft)
ClocksThisTime = ClocksLeft;
/* clock once */
Pos -= ClocksThisTime * FRAC_ONE;
ClocksLeft -= ClocksThisTime;
/* if we're out of clocks, time to handle the next state */
if (ClocksLeft == 0)
{
/* advance one state; if we hit idle, bail */
UPD7759AdvanceState();
if (Chip->state == STATE_IDLE)
break;
/* reimport the variables that we cached */
ClocksLeft = Chip->clocks_left;
Sample = Chip->sample;
}
}
}
if (SlaveMode && ClocksLeft > 0) UPD7759SlaveModeUpdate();
Chip->clocks_left = ClocksLeft;
Chip->pos = Pos;
}