Overflow in source code

[ASta]

-- FreeGeometry.pas --
  function DistanceToLine(...): TFloatType;
  begin
    ...
    Result := 1e10;
    ...
  end;
  ...
  var
    Dist: Integer
    ...
    Dist := Round(DistanceToLine(...); // Overflow error (1e10 large then integer)
----
Patch:
-- FreeGeometry.pas --
  function DistanceToLine(P1, P2:TPoint; X, Y: Integer; var Parameter: TFloatType): Integer;
  const
    VeryVeryLargeDistance = 1000000;
  var
    Pt: T2DCoordinate;
  begin
    if (P1.X<0) and (P2.X<0) then
      Result := VeryVeryLargeDistance
    else
      if (P1.X>Screen.Width) and (P2.X>Screen.width) then
        Result := VeryVeryLargeDistance
      else
        if (P1.Y<0) and (P2.Y<0) then
          Result := VeryVeryLargeDistance
        else
          if (P1.Y>Screen.Height) and (P2.Y>Screen.Height) then
            Result := VeryVeryLargeDistance
          else
            if (P2.X=P1.X) and (P1.Y=P2.Y) then
              Result := Round(Sqrt(Sqr(P1.X-X)+Sqr(P1.Y-Y)))
            else
            begin
              Parameter:=((X-P1.X)*(P2.X-P1.X)+(Y-P1.Y)*(P2.Y-P1.Y))/(sqr(P2.X-P1.X)+Sqr(P2.Y-P1.Y));
              if (Parameter>=0) and (Parameter<=1) then
              begin
                Pt.X:=P1.X+Parameter*(P2.X-P1.X);
                Pt.Y:=P1.Y+Parameter*(P2.Y-P1.Y);
                if (Pt.X>=0) and (Pt.Y>=0) and (Pt.X<=Screen.Width) and (Pt.Y<=Screen.Height) then
                  Result := Round(Sqrt(Sqr(Pt.X-X)+Sqr(Pt.Y-Y)))
                else
                  Result := VeryVeryLargeDistance;
              end
              else
                Result := VeryVeryLargeDistance;
            end;
  end;{DistanceToLine}

 
  ... := DistanceToLine(...); // was: ... := Round(DistanceToLine(...);
  ...
-- --

-- FreeShipUnit.pas --
  ...
 
  ... := FreeGeometry.DistanceToLine(...); // was: ... := Round(DistanceToLine(...);
  ...
----

Comments/ideas?