HALO SUR UNE IMAGE

procedure CreerHalo(X, Y, D : Integer; Bmp : TBitmap);
var
  I, J, adding : Integer;
  P : pRGBArray;
begin
  D := D div 2;
  for j := max(0, Y-D) to min(Y+D, bmp.Height-1) do begin
    P := bmp.ScanLine[j];
    for i := max(0, X-D) to min(X+D, bmp.Width-1) do begin
      adding := 255 - min(trunc(255*(sqrt(sqr(i-X)+sqr(j-Y))/D)),255);
      P[i].rgbtRed := min(255, P[i].rgbtRed + adding);
      P[i].rgbtGreen := min(255, P[i].rgbtGreen + adding);
      P[i].rgbtBlue := min(255, P[i].rgbtBlue + adding);
    end;
  end;
end;