Re: [Devel] round, ceil, and floor functions for 16.16 fixed values

[Tom Kacvinsky]

Hi Antoine and Werner,

I think I panicked.  The type FT_Fixed is really a signed long, which on
16 bit platforms is going to be a 32 bit integer.  Unless I am mistaken.
So I think I can go ahead and be confident that the code will work on
16 bit systems.

As for the TODO doc, that should be a top level file.  Perhaps I should
commit such a file.  The question is what form should the file take?

Tom

On Fri, 9 Mar 2001, Antoine Leca wrote:

> Werner LEMBERG wrote:
> >
> > > ... I decided to implement a fixed number rounding function ...
> > >
> > > For those machines that support 32 bit signed ints, this is not a
> > > problem.  For those machines whose largest integer is 16 bits wide,
> > > this is a problem.  I took a look at how things are down in ftcalc.c
> > > when the largest integer is 16 bits wide, but I am at a loss.
> >
> > I think that FT 2, contrary to FT 1, has not been tested whether it
> > works with 16bit integers
>
> At least, I never gave it a shot, although I certainly planned to do so.
>
> > -- I'm quite sure that it doesn't work (Antoine, please correct me if
> > I'm wrong) since I've never seen any 16bit related fixes.
>
> I do not know. I do not really expect it to be completely brocken (we
> know that the TT stuff is quite OK, and experience with FT1 show that
> a couple of fixes like adding "L" suffix here and there just work.
> Sometimes things are much more complex, such as how to deal with big
> fonts whose structures exceed the 64K limit...)
>
>
> > So don't worry, just add a remark about possible 16bit problems.
>
> Seems the way to go. This way, when someone will try to have this to work
> on a 16-bit platform (which might happen but also may not), the guy will
> know where she had to search first (BTW: the first will be the type system,
> much before diving into ftcalc.c ;-) so don't worry Tom).
> OTOH, I have no good idea of a place to collect these kinbds of comments
> (in addition to the sources themselves). In FT1 we had a docs/TODO which
> collected these kind of business, but I did not notice something similar
> in FT2.
>