FFT window.

TFFTWindow = (
  fwRectangular = 1,
  fwHamming = 2,
  fwHann = 3,
  fwCosine = 4,
  fwLanczos = 5,
  fwBartlett = 6,
  fwTriangular = 7,
  fwGauss = 8,
  fwBartlettHann = 9,
  fwBLackman = 10,
  fwNuttall = 11,
  fwBlackManHarris = 12,
  fwBlackmanNuttall = 13,
  fwFlatTop = 14
);