Re: Optimizing Pango OpenType engine

[Werner LEMBERG <wl gnu org>]

> > Yes, the lowest level can be a FreeType module.
> 
> I'm not sure if it was clear ... I meant a CVS module not a FreeType
> extension.... it would be a separate library, more so than today
> because it wouldn't use the FreeType stream API.

Indeed, I've misunderstood you.  Anyway, it would make sense to have a
FreeType `module' or `service' which handles low-level OpenType stuff
if necessary.

> > remember the problems with the MarkAttachClassDef table which has
> > been added without increasing the version number.
> 
> I don't follow this ... it seems that anything you could handle by
> parsing the table at runtime could be handled by parsing it
> beforehand.

Of course, but there is a very ugly hack in handling the
MarkAttachClassDef table -- see remarks in Pango's TT_Load_GDEF_Table
and TT_Load_GPOS_Table.  On Windows, OpenType tables are neither
loaded nor verified in (AFAIK), so they look up a MarkAttachClassDef
only if it is necessary.


    Werner