jonathan_kew at sil.org
Thu May 11 17:01:34 CEST 2006
On 11 May 2006, at 3:34 pm, Will Robertson wrote:
>>> and *fairly* sure that OpenType can do it
>>> as well.
>> I don't recall seeing this in the OpenType spec, but I'm less
>> familiar with that.
> Took me a second to find it: feature 'opbd' "Optical bounds":
Aha, thanks! Seen any fonts that provide this, though? I haven't --
not even the Adobe Pro fonts I've got.
>> Actually, when working with ATSUI on OS X, XeTeX uses a hybrid of TeX
>> and ATSUI justification.
> Yes, I've seen this and been quite upset with it :(
> I don't suppose there's a way to turn it off?
Sorry, not at present; you get XeTeX's best attempt at providing
whatever the AAT font designer specified. (Hey, font designers are
supposed to be good at this kind of typographic detail!) But I can
imagine that you might like an option to turn it off at times.
> Anyway, I'm surprised that the the combination of XeTeX and ATSUI
> works for beginning-of-line and end-of-line interactions -- I thought
> the contextuals in this area (Hoefler Text Italics' swashes, for
> example) were fairly broken at this stage and assumed that margin
> kerning would be similarly non-functional.
I think it would be at least somewhat functional if the AAT 'opbd'
table were present, but I don't have any such font and so it's not
something I've paid any real attention to.
Some day I'd like to do a more thorough job of all the line-boundary
stuff; I have some ideas how it could be done, but it'll take some
work and there's potentially a performance hit for taking those extra
variables into account. Mostly, though, it just hasn't been top
priority because it's not needed for most "normal" text setting.
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