[XeTeX] Microtypography?

Jonathan Kew 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":
>    <http://www.microsoft.com/typography/otspec/features_ko.htm#opbd>

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.


More information about the XeTeX mailing list