Re: The rabbit hole that is HiDPI... (empty menus / bug#31223 et al)

[Robert Pluim <rpluim@gmail.com>]

>>>>> On Tue, 26 Nov 2019 20:13:21 +0100, Tobias Bading <tbading@web.de> said:

    Tobias> But seriously... what would be the proper way to deal with HiDPI in
    Tobias> Emacs? Has anyone done any work on this?

xg_get_scale(). And yes, which is why my hair is turning grey.

    Tobias> I don't have much experience with GTK or HiDPI solutions on GNU/Linux in
    Tobias> general. From what I've debugged so far it seems that GTK works similar
    Tobias> to CSS, with some form of abstract pixels, which are mapped to 2x2
    Tobias> device pixels in my case. Since the low-level X11 APIs and events still
    Tobias> seem to use actual device pixels, would it make sense to look for the
    Tobias> source of the halved values returned by FRAME_MENUBAR_HEIGHT(f) et al
    Tobias> and multiply these by two in my case?

Yes, if you have scaling in GTK the number of pixels as seen by GTK is
scaled up or down. Unfortunately too much code in Emacs still works in
device pixels. Who will rid us of this turbulent mix of X and GTK?

BTW, which distribution and desktop environment is this? Ubuntu xx
with Gnome?

Robert

PS. You might have more luck with emacs-27 and 'configure
--with-cairo'