[Bf-committers] Automatic DPI detection issues

[Brecht Van Lommel]

On Thu, Jul 13, 2017 at 1:31 PM, Sergey Sharybin <sergey.vfx at gmail.com>
wrote:

> How would one know which scale factor to apply? That scaling factor would
> depend on a value which Blender detected and which is impossible to know
> unless you start doing python onelines in the console (which is not
> friendly at all).
>

It the UI is too small you scale it up, if it's too big you scale it down?


> My X11 server was reporting weird DPI of (88 x 89), which was only causing
> problems in Blender running with factory startup. All other applications
> and Blender with my previously saved suerprefs are displaying fonts
> properly.
>

It's not clear to me what you mean by improperly displayed fonts here, I
tried various DPI values in 2.78 and various UI scale values in master and
the fonts always look ok to me.


> What i'm saying is:
>
> - Using auto DPI for faqctory startup but not for saved userprefs is just
> wrong.
>

It uses auto DPI for both. What happens is that when you have saved user
preferences, it automatically sets the UI scale to preserve backwards
compatibility.


> - Not reporting detected DPI is also wrong.
>

I don't know of any other application reporting this in the UI, why does
the absolute value matter to the user?


> - Not being able to correct auto-detected DPI also sounds wrong. All the DE
> will have option to override X11 DPI specifically for the case when X11
> reports wrong DPI.
>

Again, it can be corrected by changing the UI scale. This is fully
equivalent to adjusting the DPI value.


>
> P.S. I wouldn't know if other applications are detecting DPI correctly (as
> in, not sure they are using crappy DPI of 88x89 or are rounding it to some
> more commonly used DPI), but it's only Blender which has badly rendered
> fonts on my system.
> P.P.S. Surely i can force/correct X11/DE's DPI, but then i don't see any
> benefit on the auto-detection of DPI. It only causes issues rather than
> solving anything.
>
> On Thu, Jul 13, 2017 at 1:15 PM, Brecht Van Lommel <
> brechtvanlommel at pandora.be> wrote:
>
> > As mentioned in the commit log, the UI Scale setting in the Interface tab
> > can be used, doesn't that work?
> >
> > If you look at the equivalent settings for Windows/macOS/Gnome/Unity/..
> > they also offer a scale or percentage. I see no reason to show the
> absolute
> > DPI.
> >
> > Linux doesn't have a single window manager standard for specifying DPI,
> but
> > we use the same convention as Chrome or Firefox which works in many
> window
> > managers, it certainly isn't random. Are you saying the DPI is not being
> > detect correctly on your system, while it works in other applications?
> > Perhaps we can fix that?
> >
> > On Thu, Jul 13, 2017 at 12:32 PM, Sergey Sharybin <sergey.vfx at gmail.com>
> > wrote:
> >
> > > Hi everyone,
> > >
> > > Today i've run into annoying/hard to predict situation: running my
> > regular
> > > blender was working fine, but doing --factory-startup was messing up
> > fonts
> > > in Blender's interface.
> > >
> > > it turns out, this commit is responsible for such behavior [1].
> > >
> > > What happens is, when there is existing user-preferences.blend, Blender
> > > will use DPI stored in there. Otherwise, Blender will use auto-detected
> > > DPI. This has following issues:
> > >
> > > - This is totally unpredictable, changes Blender interface based on
> some
> > > rather random factors.
> > > - Blender does not tell user what DPI it detected (yes, the commit
> > removed
> > > setting from User Preferences)
> > > - If system reports buggy DPI, there is no easy way to know what's
> > causing
> > > it and how to correct.
> > >
> > > So i think we should bring DPI setting back to user preferences. It is
> > > really bad practice to secretly use setting, without even telling what
> > the
> > > value of the setting is. It is also bad practice to auto-detect
> something
> > > and not give any clues to user what the detected value is. And finally,
> > > there should be a way to override auto-detected DPI, for the exact case
> > > when the reported one is bad.
> > >
> > > [1] https://developer.blender.org/rBfe3fb23
> > >
> > > --
> > > With best regards, Sergey Sharybin
> > > _______________________________________________
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>
>
>
> --
> With best regards, Sergey Sharybin
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