// Example of using Scanline with pf16bit Bitmap
// efg, Sept 98

procedure TForm1.ButtonFillYellowPf16bitClick(Sender: TObject);

  VAR
    Bitmap:  TBitmap;
    i     :  INTEGER;
    j     :  INTEGER;

    R     :  0..31;  // 5 bits
    G     :  0..63;  // 6 bits (eye is most sensitive to green)
    B     :  0..31;  // 5 bits

    RGB   :  WORD;
    Row   :  pWordArray;   // from SysUtils
begin
  Bitmap := TBitmap.Create;
  TRY
    Bitmap.Width  := Image1.Width;
    Bitmap.Height := Image1.Height;
    Bitmap.PixelFormat := pf16bit;

    R := 31;    // Max Red
    G := 63;    // Max Green
    B :=  0;    // No Blue

    // "FillRect" using Scanline
    RGB := (R SHL 11) OR (G SHL 5) OR B;  // "yellow"

    FOR j := 0 TO Bitmap.Height-1 DO
    BEGIN
      Row := Bitmap.Scanline[j];
      FOR  i := 0 TO Bitmap.Width-1 DO
        Row[i] := RGB
    END;

    Image1.Picture.Graphic := Bitmap
  FINALLY
    Bitmap.Free
  END
end;