// halt_osc: handle halting an oscillator
// chip = chip ptr
// onum = oscillator #
// type = 1 for 0 found in sample data, 0 for hit end of table size
private void es5503_halt_osc(ES5503Chip chip, int onum, int type, ref UInt32 accumulator, int resshift)
{
ES5503Osc pOsc = chip.oscillators[onum];
ES5503Osc pPartner = chip.oscillators[onum ^ 1];
int mode = (pOsc.control >> 1) & 3;
int partnerMode = (pPartner.control >> 1) & 3;
// if 0 found in sample data or mode is not free-run, halt this oscillator
if ((mode != (int)MODE.FREE) || (type != 0))
{
pOsc.control |= 1;
}
else // preserve the relative phase of the oscillator when looping
{
UInt16 wtsize = (UInt16)(pOsc.wtsize - 1);
UInt32 altram = accumulator >> resshift;
if (altram > wtsize)
{
altram -= wtsize;
}
else
{
altram = 0;
}
accumulator = altram << resshift;
}
// if we're in swap mode or we're the even oscillator and the partner is in swap mode,
// start the partner.
if ((mode == (int)MODE.SWAP) || ((partnerMode == (int)MODE.SWAP) && ((onum & 1) == 0)))
{
pPartner.control &= 0xff; // ~1; // clear the halt bit
pPartner.accumulator = 0; // and make sure it starts from the top (does this also need phase preservation?)
}
// IRQ enabled for this voice?
if ((pOsc.control & 0x08) != 0)
{
pOsc.irqpend = 1;
if (chip.irq_func != null)
{
chip.irq_func(chip.irq_param, 1);
}
}
}
private void es5503_pcm_update(ES5503Chip param, UInt32 samples, int[][] outputs)
{
byte osc;
UInt32 snum;
UInt32 ramptr;
ES5503Chip chip = param;
byte chnsStereo, chan;
for (int i = 0; i < samples; i++)
{
outputs[0][i] = 0;
outputs[1][i] = 0;
}
if (chip.docram == null)
{
return;
}
chnsStereo = (byte)(chip.output_channels & 0xff); // ~1;
for (osc = 0; osc < chip.oscsenabled; osc++)
{
ES5503Osc pOsc = chip.oscillators[osc];
if ((pOsc.control & 1) == 0 && pOsc.Muted == 0)
{
UInt32 wtptr = pOsc.wavetblpointer & wavemasks[pOsc.wavetblsize];
UInt32 altram;
UInt32 acc = pOsc.accumulator;
UInt16 wtsize = (UInt16)(pOsc.wtsize - 1);
UInt16 freq = pOsc.freq;
Int16 vol = pOsc.vol;
byte chnMask = (byte)((pOsc.control >> 4) & 0x0F);
int resshift = resshifts[pOsc.resolution] - pOsc.wavetblsize;
UInt32 sizemask = accmasks[pOsc.wavetblsize];
Int32 outData;
chnMask &= chip.outchn_mask;
for (snum = 0; snum < samples; snum++)
{
altram = acc >> resshift;
ramptr = altram & sizemask;
acc += freq;
// channel strobe is always valid when reading; this allows potentially banking per voice
chip.channel_strobe = (byte)((pOsc.control >> 4) & 0xf);
pOsc.data = chip.docram[ramptr + wtptr];
if (pOsc.data == 0x00)
{
es5503_halt_osc(chip, osc, 1, ref acc, resshift);
}
else
{
outData = (pOsc.data - 0x80) * vol;
// send groups of 2 channels to L or R
for (chan = 0; chan < chnsStereo; chan++)
{
if (chan == chnMask)
{
outputs[chan & 1][snum] += outData;
}
}
outData = (outData * 181) >> 8; // outData *= sqrt(2)
// send remaining channels to L+R
for (; chan < chip.output_channels; chan++)
{
if (chan == chnMask)
{
outputs[0][snum] += outData;
outputs[1][snum] += outData;
}
}
if (altram >= wtsize)
{
es5503_halt_osc(chip, osc, 0, ref acc, resshift);
}
}
// if oscillator halted, we've got no more samples to generate
if ((pOsc.control & 1) != 0)
{
pOsc.control |= 1;
break;
}
}
pOsc.accumulator = acc;
}
}
}
