[tex-live] Re: [Fontforge-devel] Re: UTF8 and (La)TeX backend?

George Williams gww at silcom.com
Tue Jan 4 17:04:23 CET 2005

On Tue, 2005-01-04 at 00:09, Werner LEMBERG wrote:
> > >     Ideally, those OpenType TeX fonts should behave similar to any
> > >     other OpenType font; this means the loss of italic correction
> > >     (which isn't available in OpenType fonts), for example, but it
> > >     assures that the font interface doesn't have to cope with
> > >     special cases.
> > 
> > That's not going to work completely, not only do we loose italic
> > correction, but also design size.  Can't we agree with other parties
> > (tetex?) on a standard SFNT table for TeX specific information?
> That's an excellent idea, so I'm forwarding this to the relevant
> mailing lists.  George already has started with three SFNT tables in
> fontforge:
>   ITLC  italic correction
>   TCHL  TeX charlist
>   TEXL  TeX extension list
Actually I didn't add tables, I added new feature tags.
	ITLC is a GPOS format 1 feature (allows positioning changes to
		single glyph)
	TCHL is a GSUB format 3 feature (replaces one glyph with one of
		many glyphs)
	TEXL is a GSUB format 2 feature (replaces one glyph with many).
> Maybe we should add a fourth table to hold the missing bits...
I'd be happy to add a 'TEX ' table (or something similar) to hold TeX
font parameters. What should go in it? (I'd rather have a separate
meaning for each parameter slot than overload them as the tfm file

I think information that applies to single glyphs (italic correction,
etc.) is better done as GPOS/GSUB features if it can fit in that format.

> FWIW, design size information is already in the OpenType specs: "size"
> feature (rather than a table).
ff doesn't currently support this, but I could add that. 
> Maybe these things ought to be discussed on the OpenType mailing list too?
I brought up ITLC on the OpenType list some time ago, hoping to get it
added to the standard feature list. I was unable to do so. Perhaps if
other people expressed interest we could bring it up again?

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