On Thu, 2016-10-27 at 20:29 -0400, David Airlie wrote:
----- Original Message -----
> From: "Kevin Kofler" <kevin.kofler(a)chello.at>
> To: devel(a)lists.fedoraproject.org
> Sent: Friday, 28 October, 2016 7:50:48 AM
> Subject: Re: F25 workstation, and (almost) hidpi displays
>
> nicolas.mailhot(a)laposte.net wrote:
> > But, GTK core maintainers have always insisted those didn't exist (just
> > like they insisted on hardcoding 96 dpi, on the eve of Apple showing the
> > world it was arbitrary and obsolete).
>
> The worst is that this mentality has infected the core X11 as well, also
> breaking KDE's code that would carefully compute the correct DPI, if only
> X11 would not go out of its way to lie to it about the physical screen size!
You could use the randr protocol to read the physical screen size,
DP-3-1 connected primary 1920x1200+0+0 (normal left inverted right x axis y axis) 518mm x
324mm
Not sure what you think is hiding it, sounds like KDE is just broken.
Well, no, that's not fair - X allows you to query the display size, and
it used to return whatever the display claimed was its physical size,
then it changed to returning a lie explicitly intended to cause things
that do a DPI calculation to calculate 96pdi. KDE uses that X
interface, and so when X changed its behaviour, it resulted in KDE
almost always rendering at 96dpi (which is basically the result the X
change wanted, but wasn't necessarily what the KDE developers wanted).
It's true that they *can* still query the actual EDID-reported display
size somehow, but it's not really fair to say that KDE is 'broken' when
X explicitly went and changed the interface KDE was using with the
intent of making KDE do something different to what it thought it was
doing.
--
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Twitter: AdamW_Fedora | XMPP: adamw AT happyassassin . net
http://www.happyassassin.net