Re: Fontforge sample font does not render correctly in Pango

[Behdad Esfahbod <behdad behdad org>]

On Fri, 2007-05-04 at 09:32 +0300, Dov Grobgeld wrote:
> In the process of learning contextual features in OpenType fonts, I
> have downloaded the FormalScript font available at:
> 
>     http://fontforge.sourceforge.net/sfds/index.html
> 
> This font contains illustrations of "Chaining Contextual
> Substitution".
> 
> Unfortunately I have not got the chaining contextual substitution
> features of this font to work under pango. In the FontForge tutorial
> at: 
> 
>     http://fontforge.sourceforge.net/editexample6-5.html
> 
> It says that the OpenType spec does not support contextual features
> for Latin scripts. Does pango/Harfbuzz honor this part of the
> specification, or is it a bug in either the font or in Pango/Harfbuzz?

Sounds like a bug to me.  The shaping modules just get to choose which
features to apply.  What kind of lookups there are in the features is
irrelevant.

Try passing the font through pango/pango/opentype/harfbuzz-dump to see
if HarfBuzz is correctly parsing the tables.  And debug from there...

There is currently no testing tool for Pango, but if you check out the
latest harfbuzz trees, the Qt developers have been adding some testing
facilities there that you may or may not find helpful.  I personally
attack this kind of problems by way of g_message :).

> Regards,
> Dov

-- 
behdad
http://behdad.org/

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