Re: fontconfig dpi issue

[Werner LEMBERG]

> I hope that some font guru (Werner?) can step in and give some
> feedback.

I've seen this a few days ago but no time to reply, sorry.

>> I ran into an issue with font rendering in Lilypond where text
>> characters are far too large. This issue also affected several
>> other users and is described here
>> <https://bbs.archlinux.org/viewtopic.php?id=211350>.  It turns out
>> that if the dpi setting is manually set in the fontconfig
>> fonts.conf file, Lilypond will adopt that dpi setting (rather than
>> the standard setting used in Lilypond, which is 1200) and render
>> all text too large.
> 
> Before I create an issue on the tracker, some developer should say
> if LilyPond or LXQT must be fixed.  I have no idea about it.

I think it's a lilypond bug, since setting a DPI value is for stuff
that goes to the screen and/or a selected printer, but lilypond should
produce stuff that does not depend on the DPI.

>> I also have a proposed patch that fixes the problem described,
>> although I don't know if this is the proper way to fix it: [...]

Me neither, unfortunately, since I have never worked with Pango.
However, your patch looks reasonable.

>> I also created a minimal Pango example that reproduces the bug here
>> <http://stackoverflow.com/questions/40325159/why-is-the-font-map-resolution-reset-when-using-fontconfig-2-11-94>.

Have you already reported the problem to the fontconfig people?  Maybe
they can give more advice.


    Werner