// call this for the first channel
void GeneratePercussion(bool opl3Mode, Chip chip, short[] output, int pos)
{
Channel chan = this;
//BassDrum
int mod = (old[0] + old[1]) >> feedback;
old[0] = old[1];
old[1] = Op(0).GetSample(mod);
//When bassdrum is in AM mode first operator is ignored
if ((chan.regC0 & 1) != 0)
{
mod = 0;
}
else
{
mod = old[0];
}
short sample = Op(1).GetSample(mod);
//Precalculate stuff used by other outputs
int noiseBit = chip.ForwardNoise() & 0x1;
int c2 = Op(2).ForwardWave();
int c5 = Op(5).ForwardWave();
int phaseBit = (((c2 & 0x88) ^ ((c2 << 5) & 0x80)) | ((c5 ^ (c5 << 2)) & 0x20)) != 0 ? 0x02 : 0x00;
//Hi-Hat
uint hhVol = Op(2).ForwardVolume();
if (!EnvSilent((int)hhVol))
{
var hhIndex = ((phaseBit << 8) | (0x34 << (byte)(phaseBit ^ (noiseBit << 1))));
sample += Op(2).GetWave(hhIndex, hhVol);
}
//Snare Drum
uint sdVol = Op(3).ForwardVolume();
if (!EnvSilent((int)sdVol))
{
int sdIndex = (int)((0x100 + (c2 & 0x100)) ^ (noiseBit << 8));
sample += Op(3).GetWave(sdIndex, sdVol);
}
//Tom-tom
sample += Op(4).GetSample(0);
//Top-Cymbal
uint tcVol = Op(5).ForwardVolume();
if (!EnvSilent((int)tcVol))
{
var tcIndex = ((1 + phaseBit) << 8);
sample += Op(5).GetWave(tcIndex, tcVol);
}
sample <<= 1;
if (opl3Mode)
{
output[pos] += sample;
output[pos + 1] += sample;
}
else
{
output[pos] += sample;
}
}
// call this for the first channel
void GeneratePercussion(bool opl3Mode, Chip chip, int[] output, int pos)
{
Channel chan = this;
//BassDrum
int mod = (int)((old[0] + old[1])) >> feedback;
old[0] = old[1];
old[1] = Op(0).GetSample(mod);
//When bassdrum is in AM mode first operator is ignored
if ((chan.regC0 & 1) != 0)
{
mod = 0;
}
else
{
mod = old[0];
}
int sample = Op(1).GetSample(mod);
//Precalculate stuff used by other outputs
uint noiseBit = chip.ForwardNoise() & 0x1;
int c2 = Op(2).ForwardWave();
int c5 = Op(5).ForwardWave();
int phaseBit = (int)((((c2 & 0x88) ^ ((c2 << 5) & 0x80)) | ((c5 ^ (c5 << 2)) & 0x20)) != 0 ? 0x02 : 0x00);
//Hi-Hat
uint hhVol = Op(2).ForwardVolume();
if (!EnvSilent((int)hhVol))
{
var hhIndex = ((phaseBit << 8) | (0x34 << (byte)(phaseBit ^ (noiseBit << 1))));
sample += Op(2).GetWave(hhIndex, hhVol);
}
//Snare Drum
uint sdVol = Op(3).ForwardVolume();
if (!EnvSilent((int)sdVol))
{
int sdIndex = (int)((0x100 + (c2 & 0x100)) ^ (noiseBit << 8));
sample += Op(3).GetWave(sdIndex, sdVol);
}
//Tom-tom
sample += Op(4).GetSample(0);
//Top-Cymbal
uint tcVol = Op(5).ForwardVolume();
if (!EnvSilent((int)tcVol))
{
var tcIndex = ((1 + phaseBit) << 8);
sample += Op(5).GetWave(tcIndex, tcVol);
}
sample <<= 1;
if (opl3Mode)
{
output[pos] += sample;
output[pos + 1] += sample;
}
else
{
output[pos] += sample;
}
}