case fDirection of
  mdUpLeft: begin
    Left := Left - Trunc(fCurrentPos);
    Top := Top - Trunc(fCurrentPos)
  end;
  mdUp: Left := Left - Trunc(fCurrentPos);
  mdUpRight: begin
    Left := Left + Trunc(fCurrentPos);
    Top := Top - Trunc(fCurrentPos)
  end;
end;