Re: Variable pitch text filling

[Lars Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

> Actually, CJK users are likely to turn this on globally.

Yeah, I guess.  But I think it's acceptable to get a slowdown for an
optional setting.

Outside of CJK settings, it's likely that things that use a tabulated
display would set this to avoid having glitches when showing CJK
characters -- but we'd only insert the spacing glyphs when we see some
CJK characters, so it should be OK there, too.

>> But I don't know how to benchmark this.
>
> Write some Lisp to add a (space :width (1)) display spec on every
> second letter of a large buffer, and then scroll through it one line
> at a time, calling redisplay after each scroll.  You'd probably need
> to disable double-buffering, to avoid its skewing the results.  Some
> of the slowdown will be due to processing the display properties, but
> if we care about that, we could measure just that separately and
> subtract.

I think it's likely that the `display' handling would greatly overwhelm
the benchmark, so perhaps the only way to get a realistic benchmark is
to implement it and see.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no