Re: Tick Reduction

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: dgutov@yandex.ru,  stefankangas@gmail.com,  emacs-devel@gnu.org
> Date: Mon, 22 Nov 2021 12:22:37 +0100
> 
> If you say (propertize "😀foo" '(space :relative-width 1)) then it's
> supposed to make a space that's two normal characters wide?  (Since 😀
> has a char-width of 2.)

No, not on GUI frames.  On GUI frames this works at pixel resolution,
so it produces (or should, but currently fails to produce) a stretch
of whitespace whose pixel width is exactly like that of the glyph for
😀 produced by your font.  char-width is only for TTY frames and for
crude approximations on GUI frames.

> Well, OK, I can vaguely see how that
> might be useful, but it seems like it would be as easy to just say
> 
> (propertize "😀foo" `(space :width ,(char-width ?😀)))
> 
> wouldn't it?

As easy, yes.  But it's supposed to be much more accurate than
char-width.