Animate Bitmaps with CopyRect

var
  Form1: TForm1;
  x, y, xvel, yvel, xold, yold: Integer;
  
//

procedure TForm1.Button1Click(Sender: TObject);
var
  ARect: TRect; // Destination/Source rectangles
begin
  //Initialize sprites position/velocity
  x    := 0;
  y    := 100;
  xvel := 3;
  yvel := 2;
  xold := 0;
  yold := 0;

  // copy background to the image
  ARect := Rect(0, 0, Image1.Width, Image1.Height);
  with Image1.Canvas do
  begin
    CopyMode := cmSrcCopy;
    CopyRect(ARect, Image1.Canvas, ARect);
  end;

  // start animation
  Timer1.Enabled := True;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
var
  Dest, Sour: TRect; // Destination/Source rectangles
begin
  // Erase sprite from old position
  Sour := Rect(xold, yold, xold + Image2.Width, yold + Image2.Height);
  with Image1.Canvas do
  begin
    CopyMode := cmSrcCopy;
    CopyRect(Sour, Image1.Canvas, Sour);
  end;

  // Draw new sprite
  Sour := Rect(0, 0, Image2.Width, Image2.Height);
  Dest := Rect(x, y, x + Image2.Width, y + Image2.Height);
  with Image1.Canvas do
  begin
    // Place mask onto image
    CopyMode := cmSrcAnd;
    CopyRect(Dest, Image2.Canvas, Sour);
    // Place sprite into mask
    CopyMode := cmSrcPaint;
    CopyRect(Dest, Image3.Canvas, Sour);
  end;

 {if multiple sprites are being used, then erase them all before drawing them
  all. Do not erase and draw each sprite in turn}

  // store sprites old position before updating
  xold := x;
  yold := y;

  { Update sprites position (equations to describe movement of sprite }
  Inc(x, xvel);
  Inc(y, yvel);
  if (x > Image1.Width - Image2.Width) or (x < 0) then xvel := -xvel;
  if (y > Image1.Height - Image2.Height) or (y < 0) then yvel := -yvel;
end;