[XeTeX] anti-xunicode ;-)

[Jonathan Kew]

On 21 Jul 2006, at 2:58 pm, François Charette wrote:
>> You also need a declaration for how \d  works
>> with the 'UX' encoding.
>> If this is the same as for T1 or T3 then you could
>> just use those instead.
> \d is identical in all font encodings, since it simply uses the  
> glyph "." in the current font.

Yes; but this is not true in general for most of the accents, which  
are at specific (non-standard) places in CM and other fonts.

Even \d could be implemented for Unicode/OpenType fonts in terms of U 
+0323 (if available) rather than the period.

> Will Robertson wrote:
>> Hi Francois,
>>
>> (Sorry about the cedilla, but I'm on a windows machine at uni and
>> don't know how to type them!)
My solution in that situation would be to copy and paste the ç from  
an existing instance of his name! :)

> Good idea: I had also tried something along these lines... but no,  
> that doesn't work :-(  Once we have reimplemented that macro  
> though, I think it might be a good thing to integrate it to xltxtra  
> instead of creating yet another package. Perhaps xdiacomp then,  
> once it comes to maturity, could be better implemented as an option  
> to the xltxtra package? Ideally it should contain a large  
> collection of "fallback macros" (which can be put together from the  
> data in D. Unruh's ucs package), and it would be up to the user to  
> decide which Unicode characters (or even better, range of  
> characters) should be made \active. For instance by typing  
> something like:
> \MakeUnicodeRangeActive{1D80}{1DBF}
> the characters in the Block "Phonetic Extensions Supplement" would  
> become automagically active, and in the absence of the appropriate  
> glyphs in the font, their fallback macros (in this case via tipa's  
> T3 encoding) would do the job of providing the glyphs. An  
> additional option could also make it possible to choose the  
> preferred fontfamily for that encoding (here ptm or cmr), depending  
> of which one harmonizes best with the default roman font. Another  
> possibility, perhaps, would be an option for declaring a second  
> OpenType font as a fallback before getting at the LaTeX macro,  
> though in general this might not be really advisable.

I'd be pretty wary of fallbacks that involve getting glyphs from  
another font; what I think is much more useful, in general, is the  
ability to fall back to the use of \accent, etc., when the font  
doesn't include all the precomposed glyphs (or full positioning  
support so that decomposed Unicode sequences of base + diacritic(s)  
render well).

This could be a little like a generalized extension of MLTeX's  
\charsubdef, which in theory exists in xetex, but is not fully  
Unicode-enabled. This is something I'd like to enhance at some point,  
as suggested by Mojca, but I can't offer a timescale of when it might  
happen.

JK