[HarfBuzz] Question about HarfBuzz-ng CTL Shaper Status

[Jonathan Kew]

On 16 Sep 2010, at 22:43, Ed wrote:

> Thanks for the very useful information, Jonathan!
> 
> What I am seeing so far (for Tai Tham) is that I can get GSUB "ccmp"
> with "dflt" ligature substitutions to work on both FF-3.6x,
> FF-4x-linux, and FF-4x-osx.  

This suggests that pango (on Linux) and CoreText (on OS X) support those features by default, I think.

> But GPOS "mark" with "dflt" mark-to-base
> don't work on any of these.
> 
> The only way I can get diacritical marks to position somewhat
> correctly is by using negative left bearings - which I would prefer to
> not do.  But obviously I may have to use negative left bearings if
> that is the only way that actually works ...
> 
> Overall all I can say is: yuck! :-(
> 
> I think what I would like to do, ideally, is create a "pure" version
> of the font that uses only proper OpenType features.  Then after that,
> I could add certain "corruptions" like negative left bearings.  But as
> it currently stands, I don't even know what to use to test the "pure"
> version of such a font ...
> 
> Any suggestions?

Maybe it would work in XeTeX? (Which uses the ICU layout engine, not harfbuzz, but ought to support the features you're using.)

JK