[Fontconfig] Application fonts with Pango+fontconfig

[Behdad Esfahbod]

On 15-05-10 12:10 PM, Khaled Hosny wrote:
> On Fri, May 01, 2015 at 07:19:11PM -0400, Behdad Esfahbod wrote:
>> Hi all,
>>
>> I am at the Libre Graphics Meeting in Toronto this week, which meant that I
>> got to talk to GIMP and Inkscape developers after many years, and was reminded
>> that Pango still doesn't make it easy to use custom (aka application fonts),
>> and it still does not allow one to turn OpenType features on or off.  So I
>> ended up doing a complete review of the stack, fixed small stuff, filed many
>> bugs, and documented it all.  Details here:
>>
>> http://mces.blogspot.ca/2015/05/how-to-use-custom-application-fonts.html
>>
>> Hopefully we can make the next release of the stack much better, and work with
>> app developers to integrate these.
> 
> I gave it a try[1] and it seems to work for my use case (I don’t even
> need to select a Pango font, since might is the only one Pango seems to
> just pick it), with one glitch: If the font gets changed while the
> viewer is open (e.g. adding or removing glyphs), Pango will start
> drawing garbage glyphs (seems to be using the old glyph indices) even
> though I recreate the config, fontmap, layout and everything. This is
> specially important for this application as I use it to test fonts while
> I’m working on them, not sure if it is that relevant for common use
> cases.

That's so weird.  How do you test this?

I just ran it, and if I copy a new font on top of the filename, the app
instantly picks it up (I'm not sure how!), but there doesn't seem to any issue
with glyph numbers.  I tested copying NotoNastaliq and IranNastaliq on top of
each other and it works just fine.

> 
> This seems to be a general Pango issue, if I modify a font while
> an application is using it, I get similar issues. 
> 
> Regards,
> Khaled
> 
> 1. https://github.com/khaledhosny/fontview/commit/0353750
> 

-- 
behdad
http://behdad.org/