Bug 1770047 - Subpixel rendering failure in Fedora 31 for right-aligned windows on a multihead machine.
Summary: Subpixel rendering failure in Fedora 31 for right-aligned windows on a multih...
Keywords:
Status: CLOSED EOL
Alias: None
Product: Fedora
Classification: Fedora
Component: mutter
Version: 31
Hardware: x86_64
OS: Linux
unspecified
medium
Target Milestone: ---
Assignee: Florian Müllner
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
: 1770148 (view as bug list)
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2019-11-08 01:03 UTC by Alastair D'Silva
Modified: 2020-11-24 16:18 UTC (History)
19 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed: 2020-11-24 16:18:45 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)
Good and bad image examples, plus xrandr output (7.32 MB, application/x-tar)
2019-11-08 01:03 UTC, Alastair D'Silva
no flags Details
Correct rendering before switching workspaces (3.53 MB, image/png)
2019-11-08 01:05 UTC, Alastair D'Silva
no flags Details
Faulty rendering after switching virtual workspaces (3.78 MB, image/png)
2019-11-08 01:06 UTC, Alastair D'Silva
no flags Details
Xrandr output describing the monitor layout (432 bytes, text/plain)
2019-11-08 01:06 UTC, Alastair D'Silva
no flags Details
Distorted font (177.59 KB, image/png)
2020-02-20 14:56 UTC, Jiri Eischmann
no flags Details


Links
System ID Private Priority Status Summary Last Updated
GNOME Gitlab GNOME/mutter/issues/804 0 None None None 2020-02-20 15:04:38 UTC

Description Alastair D'Silva 2019-11-08 01:03:32 UTC
Created attachment 1633829 [details]
Good and bad image examples, plus xrandr output

Description of problem:
I have a 3 monitor setup:
Left: Dell 3007WFP 2560x1600
Middle: Seiki 40" 4K TV 3840x2160
Right: Thinkpad T480 builtin 2048x1152

When a Firefox instance (or Gnome Text Editor window) is right aligned (meta-right) on the middle screen, it displays properly. However, after switching virtual consoles (ctrl-alt-up/down/left/right), and returning back, the right aligned window show subpixel rendering artifacts.

I've attached screenshots before & after switching consoles, the window that displays the problem is the right browser in the middle screen (visiting Opencores).

This problem did not occur in Fedora 30, only after upgrading to Fedora 31.

The problem also does not occur if I move the window away from the edge of the centre display.

Version-Release number of selected component (if applicable):
freetype.x86_64 2.10.0-3.fc31 @fedora

How reproducible:
Every time, with my display configuration

Steps to Reproduce:
1. Launch Gnome Text Editor, ensure it is on the middle screen and enter some text
2. Right align the window (meta-right)
3. Shift away and back to the virtual console
4. Observe text that was currectly rendered in the text editor now has artifacts

Actual results:
Poorly rendered text

Expected results:
Correctly rendered text

Additional info:

Comment 1 Alastair D'Silva 2019-11-08 01:05:05 UTC
Created attachment 1633830 [details]
Correct rendering before switching workspaces

Comment 2 Alastair D'Silva 2019-11-08 01:06:12 UTC
Created attachment 1633831 [details]
Faulty rendering after switching virtual workspaces

Comment 3 Alastair D'Silva 2019-11-08 01:06:43 UTC
Created attachment 1633832 [details]
Xrandr output describing the monitor layout

Comment 4 Marek Kašík 2019-11-13 16:32:14 UTC
Hi,

this is probably an issue in mutter. It seems like scaling between DPIs goes wrong. This affects also other graphics elements, not just text.
I'm reassigning this to mutter for further investigation.
Btw, there is one possible duplicate of this - #1770148.

Regards

Comment 5 Jiri Eischmann 2020-02-20 14:56:42 UTC
Created attachment 1664430 [details]
Distorted font

Comment 6 Jiri Eischmann 2020-02-20 14:57:15 UTC
I'm experiencing what seems to be the same problem:

I've got two monitors: one 4k on the left, one FullHD on the right (primary). When there is a window on the primary display that has the left side on the edge of the two displays, its content is rendered incorrectly, most visible on the font (see on the attached screenshot). If I move the window somewhere else, the rendering is fixed.

I'm using Fedora 31 (GNOME on Wayland), but as I just tested the same problem stays in Fedora 32.

Comment 7 Olivier Fourdan 2020-02-20 15:01:43 UTC
https://gitlab.gnome.org/GNOME/mutter/issues/804 ?

Comment 8 Jiri Eischmann 2020-02-20 15:06:07 UTC
*** Bug 1770148 has been marked as a duplicate of this bug. ***

Comment 9 Kevin Kofler 2020-02-20 15:32:16 UTC
Note that, unlike the OP's screenshot and the bug subject, Jiri Eischmann's screenshot is NOT subpixel-antialiased, only grayscale. But it looks similarly wrong.

Comment 10 Ben Cotton 2020-11-03 17:05:07 UTC
This message is a reminder that Fedora 31 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora 31 on 2020-11-24.
It is Fedora's policy to close all bug reports from releases that are no longer
maintained. At that time this bug will be closed as EOL if it remains open with a
Fedora 'version' of '31'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version.

Thank you for reporting this issue and we are sorry that we were not 
able to fix it before Fedora 31 is end of life. If you would still like 
to see this bug fixed and are able to reproduce it against a later version 
of Fedora, you are encouraged  change the 'version' to a later Fedora 
version prior this bug is closed as described in the policy above.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events. Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

Comment 11 Ben Cotton 2020-11-24 16:18:45 UTC
Fedora 31 changed to end-of-life (EOL) status on 2020-11-24. Fedora 31 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of
Fedora please feel free to reopen this bug against that version. If you
are unable to reopen this bug, please file a new report against the
current release. If you experience problems, please add a comment to this
bug.

Thank you for reporting this bug and we are sorry it could not be fixed.


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