[Fontconfig] Request for implementing font substitution for CJK fonts

[Nicolas Mailhot]

Le Jeu 31 mai 2012 15:17, Akira TAGOH a écrit :

> Honestly I would rather want to get rid of even them from fontconfig
> tree in the future. the classification can be guessed from  the panose
> and the OS2 table.

When they are correctly filled

The Microsoft WWS whitepaper explicitely stated that in-the-wild font metadata
was garbage, the only thing one could rely on was the font name (because it's
user-visible so errors tend to get caught) and even there they had to define
elaborate heuristics to try to correct existing mistakes (and we have regular
reports of fonts that pretend to be Arial or Times New Roman because their
author copied the metadata of those fonts as a starting point and never
sanitized it).

And Microsoft wrote this after consulting major foundries and Adobe so I'd say
it's pretty authoritative.

If you add dependencies on more font metadata the way to override bad metadata
must be explicitely documented (with examples) so distributors can workaround
problem fonts

And as I've stated a long time ago fontconfig does not help font authors and
distributors now to apply the minimal metadata rules defined in WWS, so could
we please finish cleaning up the metadata parts where we have clear industry
guidance before embarking on fontconfig-specific metadata processing rules?
That would imply :
1. implementing the name/style fallbacks defined in the WWS whitepaper in
fontconfig
2. warning in fontconfig debug output when a font hits those fallbacks
(meaning its metadata is wrong and an heuristic had to be applied to fix it)

Regards,

-- 
Nicolas Mailhot