SCAR Code:
procedure CreateLine(out tpa: TPointArray; radial: Extended; radius, cx, cy: Integer);
var
  r: Extended;
  ex, sx, x: Integer;
begin
  r := Tan(radial);
  if (Abs(r) <= 1) then
  begin
    ex := Round(Cos(radial) * radius);
    SetLength(tpa, iAbs(ex) + 1);

    sx := Min(0, ex);
    ex := Max(0, ex);

    for x := sx to ex do
    begin
      tpa[-sx + x] := Point(cx + x, cy + Round(x * r));
    end;
  end
  else
  begin
    ex := Round(Sin(radial) * radius);
    SetLength(tpa, iAbs(ex) + 1);
    
    sx := Min(0, ex);
    ex := Max(0, ex);
    
    for x := sx to ex do
    begin
      tpa[-sx + x] := Point(cx + Round(x / r), cy + x);
    end;
  end;
end;

I would hazard a guess that this method of point producing is faster since the main looping only involves 1 multiply or divide. It should produce a reasonable line and if you wanted filtering rather than creating, you could also adapt it to use Bullzeye's filtering method.