[cairo] [patch] caching, glyph, font, and glyphset patch, round 2

Bill Spitzak spitzak at d2.com
Thu Oct 7 13:35:34 PDT 2004

On Thursday 07 October 2004 09:11 am, Keith Packard wrote:

> I might also use a (semi-)kludge to avoid a memory reference:
> 	#define DEAD_ENTRY	((cario_cache_entry_base_t *) 1)

I think this is a much better idea than pointing at some dummy structure. 
This will produce a crash if dereferenced, while the other form might hide 

> I'm wondering if there's a way to use 8 or 16 bit values for glyphs; for
> some applications, quadrupling the size of glyph information will
> measurably impact network utilization.   Perhaps we just don't care,
> expecting that gzip will be able to compress this down in most cases.
> To do so would necessitate the use of multiple glyphsets.  Is this
> possible?  Can we retro fit this later?

Do you mean for the glyph id's? Certainly not, Unicode defines the range as 
being from 0-0x10ffff.

And perhaps Pango could use the higher bits to identify "alternative forms" 
to the lower level code, for instance asing for glyph 0x01000041 will give 
you alternative form 1 of an 'a'? Not clear what is needed, Pango would have 
to set up seperate fonts, but this could probably accomplish most or all of 
the reason people want a "font id" passed with every glyph.

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