Animation for FFT

The MoPL-3 listing is stated below.

Please enable JAVA to see this applet !

array                   CGFFT [1:9, 1:16] of float;

scanPattern             SP1     is 7 steps [0,2];
                        SP23    is 7 steps [0,1];
                        HLScan is 3 steps [2,0];

window                  ThreeW is
                        SW1      [1:2, 1:2] of float;
                        SW2, SW3 [1:1, 1:1] of float;

rALUsubnet FFT of ThreeW is
                        SW2 [1,1] = SW1[1,1] + SW1[2,1] * SW1[1,2];
                        SW3 [1,1] = SW1[1,1] - SW1[2,1] * SW1[1,2];

begin
with ThreeW do begin
    activate FFT;
    move SW1 to CGFFT [0,0];
    move SW2 to CGFFT [2,0];
    move SW3 to CGFFT [2,8];
    HLScan (parbegin
      SP1[SW1];
      SP23[SW2];
      SP23[SW3];
    parend;) [SW1, SW2, SW3];
end;
end;