Re: Ligature support

[Lars Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

> 30% slowdown is already a bad sign.

Oh yeah, it means that we can't just do that.  If we want to send
everything through hb_shape, we'd have to change our display to optimise
for that case.  (Which I'm guessing would be a lot of work.)

Today it's doing a lot of work to pick and choose those bits.

> Are we willing to make our redisplay 3 times slower with plain ASCII
> text?

Nope.

> I think the current design of character compositions in Emacs is
> inappropriate for sending all the text via the shaping engine.  It was
> designed on the assumption that composed characters will be rare in
> "normal" usage, and will only be massive in some specific scripts
> where this is unavoidable, like Arabic and Hangul.  If we want to call
> the shaper for everything we display, we should radically change how
> this is designed and implemented.

Yes, indeed.

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