Gradient ProgressBar komponens

procedure TGrdProgressBar.Paint;
var xp:array[0..1] of integer;
    yp, xt, yt, t:integer;
    vert: array[0..1] of TRIVERTEX;
    gr: TGradientRect;
    col, shcol:TColor;
    percent:integer;
    percstr:string;
begin
  inherited;

  Canvas.Font.Assign(FFont);

  yp:=Height div 2;

  if FMax=0 then FMax:=1;

  percent:=Round(FPosition*100/FMax);

  xp[0]:=Width;
  xp[1]:=Round(Width*(percent/100));

  for t:=0 to 1 do  begin

    if t=0 then begin
      col:=ColorToRGB(FBgColor);
      shcol:=ColorToRGB(FBgShadowColor);
   end else begin
      col:=ColorToRGB(FColor);
      shcol:=ColorToRGB(FShadowColor);
    end;

    with vert[0] do  begin
      x:=0;
      y:=0;
      Red:=GetRValue(shcol)*256;
      Green:=GetGValue(shcol)*256;
      Blue:=GetBValue(shcol)*256;
      Alpha:=0;
    end;
    with vert[1] do  begin
      x:=xp[t];
      y:=yp;
      Red:=GetRValue(col)*256;
      Green:=GetGValue(col)*256;
      Blue:=GetBValue(col)*256;
      Alpha:=0;
    end;
    gr.UpperLeft:=0;
    gr.LowerRight:=1;

    GradientFill(Canvas.Handle, @vert, 2, @gr, 1, GRADIENT_FILL_RECT_V);

    vert[0].y:=Height;
    vert[1].y:=yp;
    gr.UpperLeft:=1;
    gr.LowerRight:=0;
    GradientFill(Canvas.Handle, @vert, 2, @gr, 1, GRADIENT_FILL_RECT_V);
 end;

  if FShowText then begin
    percstr:=IntToStr(percent)+' %';
    xt:=(Width div 2) - (Canvas.TextWidth(percstr) div 2);
    yt:=(Height div 2) - (Canvas.TextHeight(percstr) div 2);
   Canvas.Brush.Style:=bsClear;  
   Canvas.TextOut(xt, yt, percstr);
  end;
end;