procedure TForm2.DrawShadows(WDepth, HDepth : Integer);
var
 Dst, RgnBox : TRect;
 hOldDC : HDC;
 OffScreen : TBitmap;
 Pattern : TBitmap;
 Bits : array[0..7] of WORD;
begin
 Bits[0]:=$0055;
 Bits[1]:=$00aa;
 Bits[2]:=$0055;
 Bits[3]:=$00aa;
 Bits[4]:=$0055;
 Bits[5]:=$00aa;
 Bits[6]:=$0055;
 Bits[7]:=$00aa;
 hOldDC:=Canvas.Handle;
 Canvas.Handle:=GetWindowDC(Form1.Handle);

 OffsetRgn(ShadeRgn, WDepth, HDepth);
 GetRgnBox(ShadeRgn, RgnBox);
 Pattern:=TBitmap.Create;
 Pattern.ReleaseHandle;
 Pattern.Handle:=CreateBitmap(8, 8, 1, 1, @(Bits[0]));
 Canvas.Brush.Bitmap:=Pattern;
 OffScreen:=TBitmap.Create;
 OffScreen.Width:=RgnBox.Right-RgnBox.Left;
 OffScreen.Height:=RgnBox.Bottom-RgnBox.;
 Dst:=Rect(0, 0, OffScreen.Width, OffScreen.Height);
 OffsetRgn(ShadeRgn, 0, -RgnBox.);
 FillRgn(OffScreen.Canvas.Handle, ShadeRgn, Canvas.Brush.Handle);
 OffsetRgn(ShadeRgn, 0, RgnBox.);
// BitBlt работает быстрее CopyRect
 BitBlt(OffScreen.Canvas.Handle, 0, 0, OffScreen.Width, OffScreen.Height,
  Canvas.Handle, RgnBox.Left, RgnBox., SRCAND);
 Canvas.Brush.Color:=clBlack;
 FillRgn(Canvas.Handle, ShadeRgn, Canvas.Brush.Handle);
 BitBlt(Canvas.Handle, RgnBox.Left, RgnBox., OffScreen.Width,
  OffScreen.Height, OffScreen.Canvas.Handle, 0, 0, SRCPAINT);
 OffScreen.Free;
 Pattern.Free;
 OffsetRgn(ShadeRgn, -WDepth, -HDepth);
 ReleaseDC(Form1.Handle, Canvas.Handle);
 Canvas.Handle:=hOldDC;
end;