[lltx] Re: microtypography

[Khaled Hosny]

On Fri, Feb 12, 2010 at 06:10:27PM +0100, Manuel Pégourié-Gonnard wrote:
> Elie Roux a écrit :
> > Elie Roux a écrit :
> >> The question I wanted to ask is whether we should enable it by default
> >> in luaotfload or not... Not so many people know what protrusion means,
> >> but if they knew I'm sure 99% of them would want it, so it seems
> >> logical for me to enable this kind of features by default, with of
> >> course options to unactivate it. I don't really see any disadvantage,
> >> except a different rendering between XeTeX and LuaTeX, which is not
> >> really a disadvantage for me... What do you think?
> > 
> > Sorry to answer my mail, I just got an idea: if we don't enable
> > microtypography by default, I think the best way to deal with it would
> > be through a microtype-luatex package, that would be loaded by microtype
> > and that would contain code to activate the features as well as the good
> > data for some OTF fonts. If you agree can ask Robert Schlicht what he
> > thinks about this solution... The reason I prefer a microtype-luatex
> > than an integration into microtype is because I don't think Robert wants
> > to deal with all the updates it will imply, and because I find the idea
> > of having a package for unicode that doesn't have a big machinery for
> > all 8-bit fonts attractive... Maybe we should find a better name... What
> > do you think?
> > 
> I was precisely about to suggest that these features would be more naturally
> integrated in microtype than in fontspec. Concerning the implementation details
> (microtype-luatex vs direct integration in microtype), I have no opinion, but if
> would be great to preserve the same user interface whenever it makes sense.

I tend to disagree here, I find microtypography (at least protrusion)
very font specific and should be integrated with the font handling
package (fontspec here), I don't see the point of having a separate
package for just this font feature, except may be for compatibility with
pdflatex, but then the current microtype package does this already.

Expansion and protrusion, as currently implemented in luaotfload, are
font features and thus need to be enabled at font definition time and
thus naturally fall in fontspec area, doing it separately in any other
package will just make things unnecessary complex (if possible at all)
for no real gain. And there is OpenType "Opyical Bounds" feature
('opbd') which is used to set protrusion values which need to be
supported by luaotfload/fontspec anyway.

Regards,
 Khaled

-- 
 Khaled Hosny
 Arabic localiser and member of Arabeyes.org team
 Free font developer