Re: Looking up fonts and shapers in Pango

[Pablo Saratxaga <pablo mandrakesoft com>]

Kaixo!

On Mon, Jan 24, 2000 at 04:55:16PM -0500, Owen Taylor wrote:
 
>> I don't really see the problem with looking up the shaper's coverage. Why not
>> simply have a call to the shaper which returns its coverage as a bitmap? 
> 
> The reason why not is that the coverage of a shaper depends on the coverage
> of the fonts it is using. 
> 
> So, instead of getting the coverage of the shaper, there will be the
> call to get the coverage of the font, and as you say, fonts are typically
> sparse, 

That is only a problem with fonts whose coverage isn't explicit trough
their X11 naming. Only unicode fonts are in such case.

>> The real problem is the fonts. Many East Asian fonts don't provide
>> full coverage either UniHan, or any national sub-set of UniHan. With

On the other hand the CJK fonts have a well established set of glyphs 
that *must* be present.
So the CJK fonts don't really need testing; we can safely assume they
include all the glyphs they tell they include (and if not, that particular
font desserves to be moved to /dev/null)

Then only the fonts listed as *-iso10646-1 and *-*-unicode would require
to be looked into; that would decrease the time needed to get the coverage
of all fonts, as only a small subset of them would need to be opened.
(and we could even go further for some *-*-unicode, as *-ethiopic-unicode,
and assume they only cover what they tell they cover and not open them)

-- 
Ki ça vos våye bén,
Pablo Saratxaga

http://www.ping.be/~pin19314/		PGP Key available, key ID: 0x8F0E4975