Re: [PATCH] gnu: emacs: Use libotf.

[Roel Janssen <roel@gnu.org>]

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Ludovic Courtès writes:

> Roel Janssen <roel@gnu.org> skribis:
>
>> Here's a very small patch to compile Emacs with libotf support.
>> Unfortunately for me, it hasn't given me better font rendering.
>
> Does the resulting Emacs refer to libotf, as per:
>
>   guix gc --references $(./pre-inst-env guix build emacs) | grep libotf
>
> ?

Yes, here's the output:
[roel@roel-tp guix]$ guix gc --references $(./pre-inst-env guix build emacs) | grep libotf
/gnu/store/kzc2zkdl3aadrs3iiml7vva80fgsd2b9-libotf-0.9.13

You can also see "Does Emacs use libotf?" turn to "yes" with my patch in
the overview at the end of the configure phase.

> If it does, could you check how it’s supposed to use it?  I don’t see
> how it would be used, but I guess this has nothing to do with rendering.

It seems that Emacs can use it for complex font rendering of OTF fonts:
https://www.gnu.org/software/emacs/manual/html_node/elisp/Low_002dLevel-Font.html

(search for "libotf").

> How “wrong” is font rendering for you?

I attached two screenshots, emacs-from-guix.png and
emacs-from-fedora.png.  Both are compiled with libotf support.  Besides
the missing Fira font, the text on the Emacs from Guix looks stretched
and not properly anti-aliased to me.

Kind regards,
Roel Janssen