public unsafe static void ForwardTransformLut(Complex *buffer, int length)
{
int num = length - 1;
int num2 = length / 2;
Complex complex = default(Complex);
complex.Real = 0f;
complex.Imag = 0f;
Complex c = default(Complex);
c.Real = 0f;
c.Imag = 0f;
int num3 = 0;
for (int num4 = length; num4 > 1; num4 >>= 1)
{
num3++;
}
int num5 = num2;
for (int num4 = 1; num4 < num; num4++)
{
if (num4 < num5)
{
complex = buffer[num5];
buffer[num5] = buffer[num4];
buffer[num4] = complex;
}
int num6;
for (num6 = num2; num6 <= num5; num6 /= 2)
{
num5 -= num6;
}
num5 += num6;
}
for (int i = 1; i <= num3; i++)
{
int num7 = 1 << i;
int num8 = num7 / 2;
int num9 = 16 - i;
for (num5 = 1; num5 <= num8; num5++)
{
int num10 = num5 - 1;
int num11 = num10 << num9;
c.Real = Fourier._lr[num11];
c.Imag = Fourier._li[num11];
for (int num4 = num10; num4 <= num; num4 += num7)
{
num11 = num4 + num8;
Complex.Mul(ref complex, c, buffer[num11]);
Complex.Sub(ref buffer[num11], buffer[num4], complex);
Complex.Add(ref buffer[num4], complex);
}
}
}
}
public unsafe static void ForwardTransformRot(Complex *buffer, int length)
{
int num = length - 1;
int num2 = length / 2;
Complex c = default(Complex);
c.Real = 0f;
c.Imag = 0f;
Complex complex = default(Complex);
complex.Real = 0f;
complex.Imag = 0f;
int num3 = 0;
for (int num4 = length; num4 > 1; num4 >>= 1)
{
num3++;
}
int num5 = num2;
for (int num4 = 1; num4 < num; num4++)
{
if (num4 < num5)
{
complex = buffer[num5];
buffer[num5] = buffer[num4];
buffer[num4] = complex;
}
int num6;
for (num6 = num2; num6 <= num5; num6 /= 2)
{
num5 -= num6;
}
num5 += num6;
}
for (int i = 1; i <= num3; i++)
{
int num7 = 1 << i;
int num8 = num7 / 2;
double num9 = 3.1415926535897931 / (double)num8;
for (num5 = 1; num5 <= num8; num5++)
{
int num10 = num5 - 1;
Complex.FromAngle(ref c, num9 * (double)num10);
Complex.Conjugate(ref c);
for (int num4 = num10; num4 <= num; num4 += num7)
{
int num11 = num4 + num8;
Complex.Mul(ref complex, c, buffer[num11]);
Complex.Sub(ref buffer[num11], buffer[num4], complex);
Complex.Add(ref buffer[num4], complex);
}
}
}
}
public unsafe void SetCoefficients(Complex[] coefficients)
{
this._isFast = false;
if (coefficients != null)
{
if (this._coeffBuffer == null || coefficients.Length != this._queueSize)
{
this._queueSize = coefficients.Length;
this._offset = this._queueSize * 3;
this._coeffBuffer = UnsafeBuffer.Create(this._queueSize, sizeof(Complex));
this._coeffPtr = (Complex *)(void *)this._coeffBuffer;
this._queueBuffer = UnsafeBuffer.Create(this._queueSize * 4, sizeof(Complex));
this._queuePtr = (Complex *)(void *)this._queueBuffer;
}
for (int i = 0; i < this._queueSize; i++)
{
this._coeffPtr[i] = coefficients[i];
}
this._isSymmetric = true;
this._isSparse = true;
if (this._queueSize % 2 != 0)
{
int num = this._queueSize / 2;
for (int j = 0; j < num; j++)
{
int num2 = this._queueSize - 1 - j;
Complex.Sub(ref this._dif, this._coeffPtr[j], this._coeffPtr[num2]);
if ((double)this._dif.Modulus() > 1E-06)
{
this._isSymmetric = false;
this._isSparse = false;
break;
}
if (j % 2 != 0)
{
this._isSparse = (this._coeffPtr[j].Real == 0f && this._coeffPtr[j].Imag == 0f && this._coeffPtr[num2].Real == 0f && this._coeffPtr[num2].Imag == 0f);
}
}
}
if (this._segment == null || this._segment.Length != this._fftSize)
{
this._segment = UnsafeBuffer.Create(this._fftSize, sizeof(Complex));
this._segPtr = (Complex *)(void *)this._segment;
this._kernel = UnsafeBuffer.Create(this._fftSize, sizeof(Complex));
this._kerPtr = (Complex *)(void *)this._kernel;
this._overlap = UnsafeBuffer.Create(this._fftSize, sizeof(Complex));
this._olaPtr = (Complex *)(void *)this._overlap;
this._temp = UnsafeBuffer.Create(this._fftSize, sizeof(Complex));
this._tmpPtr = (Complex *)(void *)this._temp;
}
if (this._queueSize < 64)
{
this._fftLen = 128;
goto IL_033c;
}
if (this._queueSize < 128)
{
this._fftLen = 256;
goto IL_033c;
}
if (this._queueSize < 256)
{
this._fftLen = 512;
goto IL_033c;
}
if (this._queueSize < 512)
{
this._fftLen = 1024;
goto IL_033c;
}
if (this._queueSize < 1024)
{
this._fftLen = 2048;
goto IL_033c;
}
if (this._queueSize < 2048)
{
this._fftLen = 4096;
goto IL_033c;
}
throw new Exception("kernel too long");
}
return;
IL_033c:
CpxFirFilter.FillFft(this._kerPtr, this._fftLen, this._coeffPtr, this._queueSize);
Fourier.ForwardTransform(this._kerPtr, this._fftLen, false);
this._isFast = true;
}
