[Fontconfig] how to modify the `variable` property?

[Akira TAGOH]

On Thu, May 25, 2023 at 1:25 AM Werner LEMBERG <wl at gnu.org> wrote:
>
> >> By the way, this behaviour is undocumented in the `fonts.conf`
> >> manpage.
> >
> > Sure. This can be definitely improved.
>
> Great!  It is probably sufficient to mention that `<acceptfont>` and
> `<rejectfont>` are only influenced by `<match target="scan">` and not
> by the targets 'font' and 'pattern'.

Sure. Please file an issue to keep it track.

> By the way, why is that so?  It looks like an artificial limitation,
> and as my real-world example shows it can cause problems.

No idea. I sometimes see someone want to filter out per font files by
glob though, this may be a first time to see for a certain pattern
only. so it may be just a corner case and didn't get enough feedback
on pattern-based? dunno.

> > They don't have a sort of 50-user.conf loaded?
>
> No.  LilyPond uses the fonts from the OS but can't handle Variation
> Fonts – for the default output backend it has to embed fonts in an
> intermediate PS file, and PostScript doesn't support VFs.

I mean if they use 50-user.conf, you could put a config to rewrite a
cache in the previous mail onto $HOME/.config/fontconfig/fonts.conf or
whatever. but you said you can't do it. so just wonder why.

>
> >> Any idea how this could be achieved?
> >
> > Unfortunately not because such conditions can't be represented in
> > FcPattern.
>
> In other words, there is no solution right now, correct?

If the config I suggested doesn't work anyway, I'm afraid not.

> >> If it weren't for backward compatibility I would simply ask to add a
> >> new property `namedinstance` that gets set as soon as the font index
> >> is larger than 0xFFFF...
> >
> > That would be possible. please file an rfe to
> > https://gitlab.freedesktop.org/fontconfig/fontconfig/-/issues
>
> Done:
>
>   https://gitlab.freedesktop.org/fontconfig/fontconfig/-/issues/362

Thanks.

>
>
>     Werner



-- 
Akira TAGOH