Re: Question about display engine

[Ergus]

Hi:

I have just uploaded some changes but the functionality is still not
working.

I separated the changes in 3 commits and in the last one are only the
ones I made in the xdisp.c (the ones that need to be checked, because
the rest is only infrastructure.)

see the master branch in: https://github.com/Ergus/Emacs

But at this point I will need some extra comments about what I am doing
wrong there. Ir if I am doing anything right.

The extend now is working like always (testing for the region).

In principle the region is the only face I have added :extend t

But when I set it to nil it should be not extended and it is; so some
extra condition is still missing..

The filter if condition (to merge or not) is a new macro
FACE_EXTENSIBLE_P (face). So please any hint is very welcome now.



On Tue, Sep 03, 2019 at 08:59:33PM +0200, martin rudalics wrote:
> > I don't think it's expensive enough to justify such premature
> > optimization.
>
> Earlier you preferred a lazy variant because
>
> > it scales better, because the
> > display code is frequently invoked on short portions of the text, so
> > there's no guarantee that it will actually get to producing glyphs
> > with the "extension" variant of the face, so realizing that face in
> > advance might well be waste of unneeded effort, because the additional
> > face will never be used.
>
> Either way, let's see what Ergus comes up with.
>
> martin