we can change the size of the
        <code>FFT/IFFT</code> size and the <code>HOP-SIZE</code> in realtime.
      </p>

      <p>
        <code>FFT-INPUT</code> sets the input of the local FFT.
      </p>

      <p>
        <code>COMPUTE-ABUFFER</code> updates the <code>ABUFFER</code> with
        a copy of the calculated FFT and returns the <code>ABUFFER</code>.
      </p>

      <p>
        The <code>DOFFT-POLAR</code> macro is an utility to change the values of
        one or more ABUFFERs in polar coord