public override void tick()
{
if (fft == null)
{
fft = new FFTProcessor(FFTProcessor.ProcessorMode.Bidirectional, blockSize, owner.sampleRate, FFTProcessor.WindowType.Hann);
}
SignalBuffer dbout = getSignalOutputBuffer(ioO);
SignalBuffer dbin = getSignalInputBuffer(ioI);
if (!_active)
{
return;
}
if ((dbout == null) && (dbin == null))
{
return;
}
if (buffIn == null)
{
buffIn = new double[blockSize];
buffOut = new double[blockSize];
fftOut = new double[blockSize];
re = new double[blockSize / 2];
im = new double[blockSize / 2];
buffInFill = 0;
buffOutFill = 0;
buffOutRead = 0;
}
if (dbin != null)
{
Array.Copy(dbin.data, 0, buffIn, buffInFill, owner.blockSize);
buffInFill += owner.blockSize;
if (buffInFill == blockSize)
{
fft.runFFT(ref buffIn, true, ref re, ref im);
Array.Copy(buffIn, blockSize / 2, buffIn, 0, buffInFill - blockSize / 2);
buffInFill -= blockSize / 2;
// Process FFT
int n1, n2;
double s, c;
switch (filterMode)
{
case FFTFilterMode.LowPass:
n1 = (int)Math.Floor(f1 / (double)owner.sampleRate * blockSize);
if (n1 < 0)
{
n1 = 0;
}
for (int i = n1; i < blockSize / 2; i++)
{
re[i] = im[i] = 0;
}
break;
case FFTFilterMode.HighPass:
n1 = (int)Math.Ceiling(f1 / (double)owner.sampleRate * blockSize);
if (n1 >= blockSize / 2)
{
n1 = blockSize / 2 - 1;
}
for (int i = 0; i < n1; i++)
{
re[i] = im[i] = 0;
}
break;
case FFTFilterMode.BandPass:
n1 = (int)Math.Floor(f1 / (double)owner.sampleRate * blockSize);
n2 = (int)Math.Ceiling(f2 / (double)owner.sampleRate * blockSize);
if (n1 < 0)
{
n1 = 0;
}
if (n2 >= blockSize / 2)
{
n2 = blockSize / 2 - 1;
}
for (int i = 0; i < n1; i++)
{
re[i] = im[i] = 0;
}
for (int i = n2 + 1; i < blockSize / 2; i++)
{
re[i] = im[i] = 0;
}
break;
case FFTFilterMode.BandStop:
n1 = (int)Math.Floor(f1 / (double)owner.sampleRate * blockSize);
n2 = (int)Math.Ceiling(f2 / (double)owner.sampleRate * blockSize);
if (n1 < 0)
{
n1 = 0;
}
if (n2 >= blockSize / 2)
{
n2 = blockSize / 2 - 1;
}
for (int i = n1 + 1; i < n2; i++)
{
re[i] = im[i] = 0;
}
break;
case FFTFilterMode.AllPass:
s = Math.Sin(phi);
c = Math.Cos(phi);
for (int i = 1; i < blockSize / 2; i++)
{
double _re = re[i] * c - im[i] * s;
double _im = re[i] * s + im[i] * c;
re[i] = _re;
im[i] = _im;
}
break;
case FFTFilterMode.FrequencyShifter:
n1 = (int)Math.Floor(f1 / (double)owner.sampleRate * blockSize + 0.5);
if (n1 > 0)
{ // positive shift
double df = (double)owner.sampleRate / (double)blockSize; // Bin Spacing
Array.Copy(re, 1, re, 1 + n1, blockSize / 2 - 1 - n1);
Array.Copy(im, 1, im, 1 + n1, blockSize / 2 - 1 - n1);
Array.Clear(re, 1, n1);
Array.Clear(im, 1, n1);
for (int i = 1 + n1; i < blockSize / 2; i++)
{
double T = 1.0 / i / df;
double T2 = 1.0 / (i + n1) / df;
double dphi = -2.0 * Math.PI * (T - T2) * (i + n1) * df;
s = Math.Sin(dphi);
c = Math.Cos(dphi);
double _re = re[i] * c - im[i] * s;
double _im = re[i] * s + im[i] * c;
re[i] = _re;
im[i] = _im;
}
}
if (n1 < 0)
{
n1 = -n1;
Array.Copy(re, n1 + 1, re, 1, blockSize / 2 - n1 - 1);
Array.Copy(im, n1 + 1, im, 1, blockSize / 2 - n1 - 1);
Array.Clear(re, blockSize / 2 - 1 - n1, n1);
Array.Clear(im, blockSize / 2 - 1 - n1, n1);
}
break;
}
// Transfer Back
fft.runIFFT(ref re, ref im, ref fftOut);
Array.Copy(buffOut, blockSize / 2, buffOut, 0, blockSize / 2);
Array.Clear(buffOut, blockSize / 2, blockSize / 2);
for (int i = 0; i < blockSize; i++)
{
buffOut[i] += fftOut[i];
}
buffOutFill = blockSize / 2;
buffOutRead = 0;
}
if (buffOutFill > 0)
{
if (dbout != null)
{
Array.Copy(buffOut, buffOutRead, dbout.data, 0, owner.blockSize);
buffOutRead += owner.blockSize;
}
}
}
}
