[Gs-devel] What is 'glyx' ????
Igor V. Melichev
igor at artifex.com
Mon Oct 15 07:58:05 PDT 2001
> From: gs-devel-admin at ghostscript.com on behalf of L. Peter Deutsch
> [ghost at aladdin.com]
> Sent: 15 юъ? сЁ 2001 у. 18:22
> To: igor at artifex.com
> Cc: tech at artifex.com; gs-devel at ghostscript.com
> Subject: Re: [Gs-devel] What is 'glyx' ????
> > I need to copy TT font skipping 'cmap', 'glyf' and 'loca'.
> For what purpose? I need some higher-level understanding of the function
> that you are implementing.
This is a part of FAPI project. I need to pass TT font to Agfa UFST.
Actually the "font-level" information to be passed separately
from "glyph-level", for supporting incremental Type 42 fonts.
An inconveniency comes from Agfa's format for handling this information.
I can't pass a "pointer" to the copy which GS keeps in its virtual memory.
UFST requires to serialize the font into a RAM area, *prefixing* it with
PCLEO data structure. As well as the segmentation is different than
the segmentation of "sfnt" array in PS. Therefore I copy the font
to another area. Doing this, I skip big unnecessary tables,
such as 'glyf', because glyphs are passed individually later
(actually I copy a glyph into a new area with a prefix,
then call UFST to render it, and then discard the glyph copy).
If I don't skip 'glyf' while passing the font header, it would copy almost
entite TT font, which for CJK languages may occupy about 8Meg.
So generally the skipping is an optimization,
but this is necessary optimization.
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