Re: composed characters question and suggestions for quail-cyrillic-*

[Jason Rumney <jasonr@gnu.org>]

Ted Zlatanov wrote:

> It really looks unpleasant in the font recorded here, taking up two rows
> so the accent can be displayed alone on top of the letter, so I'm
> curious if Emacs will pick the right appearance if the font has an
> accented version of the character.

No. There are no unicode codepoints for those accented characters AFAICS 
so we can't do the substitution within Emacs. The only way to combine 
them would be if the font contained GSUB (glyph substitution) tables 
with entries for those sequences of characters, and Emacs had been told 
to use font-shape-text for displaying Cyrillic (currently it is only 
used for Indic and some South East Asian scripts, but should be for 
Arabic as well). The library that Emacs uses for shaping 
(libotf/m17n-flt or on Windows uniscribe) might need some knowledge of 
those accented characters as well, I'm not entirely sure of how glyph 
shaping all fits together.

Different fonts might have different metrics for the accent characters 
though, which could improve the appearance.