procedure TForm1.Button5Click(Sender: TObject);
var
bm, bm1: TBitMap;
x, y: integer;
r, a: single;
xo, yo: integer;
s, c: extended;
begin
repeat
for y := 0 to bm.Height - 1 do begin
for x := 0 to bm.Width - 1 do begin
r := sqrt(sqr(x - xo) + sqr(y - yo));
SinCos(a + arctan2((y - yo), (x - xo)), s, c);
bm1.Canvas.Pixels[x,y] := bm.Canvas.Pixels[
round(xo + r * c), round(yo + r * s)];
end;
Application.ProcessMessages;
end;
Image1.Canvas.Draw(xo, yo, bm1);
a := a + 0.05;
Application.ProcessMessages;
until Form1.Tag <> 0;
bm.Destroy;
bm1.Destroy;
end;