[tex-live] Fontconfig for XeTeX versus regular fontconfig

[Dr. Werner Fink]

On Fri, Oct 28, 2011 at 11:35:20AM +0100, Jonathan Kew wrote:
> On 28 Oct 2011, at 11:08, Dr. Werner Fink wrote:
> > 
> > Reading the source code of web2c/xetexdir/XeTeXFontMgr_FC.cpp for
> > xetex and xdvipdfmx/src/fontmap.c and a short comparision by testing
> > leads me to the conclusion that XeTeXFontMgr_FC.cpp should be
> > redesigned.  This because it reads in *all* fonts (very slow)
> > and holds it in its own memory based cache ...
> 
> This is necessary to fully support xetex's font management - e.g., IIRC fontconfig patterns do not provide optical-size support. (Performance could be improved by caching details across runs, and just fstat'ing the files to check if they've changed, but simply using Fc patterns and relying on the Fc cache is not sufficient.)
> 

Hmmm ... OK the current implementation ignores the cache of fontconfig its
self but it is annoying slow (try to compile XeTeX-reference.ltx). An other
problem seems that not all fonts used by the documentation are part of the
TeXLive font tree.

The question is how often fonts below the TeXLive font tree will change.
Beside this fontconfig has a recheck scheme even with timings.


     Werner

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