procedure FillGradientRect(Canvas: TCanvas; Recty: TRect; fbcolor, fecolor: TColor; fcolors: Integer);
var
i, j, h, w, fcolor: Integer;
R, G, B: Longword;
beginRGBvalue, RGBdifference: array[0..2] of Longword;
begin
beginRGBvalue[0] := GetRvalue(colortoRGB(FBcolor));
beginRGBvalue[1] := GetGvalue(colortoRGB(FBcolor));
beginRGBvalue[2] := GetBvalue(colortoRGB(FBcolor));
RGBdifference[0] := GetRvalue(colortoRGB(FEcolor)) - beginRGBvalue[0];
RGBdifference[1] := GetGvalue(colortoRGB(FEcolor)) - beginRGBvalue[1];
RGBdifference[2] := GetBvalue(colortoRGB(FEcolor)) - beginRGBvalue[2];
Canvas.pen.Style := pssolid;
Canvas.pen.mode := pmcopy;
j := 0;
h := recty.Bottom - recty.Top;
w := recty.Right - recty.Left;
for i := fcolors downto 0 do
begin
recty.Left := muldiv(i - 1, w, fcolors);
recty.Right := muldiv(i, w, fcolors);
if fcolors1 then
begin
R := beginRGBvalue[0] + muldiv(j, RGBDifference[0], fcolors);
G := beginRGBvalue[1] + muldiv(j, RGBDifference[1], fcolors);
B := beginRGBvalue[2] + muldiv(j, RGBDifference[2], fcolors);
end;
Canvas.Brush.Color := RGB(R, G, B);
patBlt(Canvas.Handle, recty.Left, recty.Top, Recty.Right - recty.Left, h, patcopy);
Inc(j);
end;
end;
// Case 1
procedure TForm1.FormPaint(Sender: TObject);
begin
FillGradientRect(Form1.Canvas, rect(0, 0, Width, Height), $FF0000, $00000, $00FF);
end;