Ubuntu 18.04→19.10 ⋅ SuperTuxKart ⋅ Flickering shadows ⋅ Haswell i965
Hi,
for a couple of months now, I've noticed a big change in graphic performance while playing famous SuperTuxKart on ubuntu bionic :
shadows are flickering, all over the screen, it's a big pain for eyes ( and wonder what would happen for epileptic people ).
Important note 1 : the same version of supertuxkart, with same graphical settings, plays nicely on the same computer when booted in ubuntu 16.04.
Important note 2 : same setup used to play nicely with 18.04 until june'19 I'd say.
Important note 3 : testing newer mesa drivers from padoka's or x-swat ppa's does not fix that flickering problem.
Important note 4 : trying with ubuntu 19.10 does not fix either.
→ regression.
Here are actual specifications of my computer booted in 18.04 / using x-swat ppa :
coeur-noir@asgard:~$ inxi -G
Graphics: Card: Intel Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller
Display Server: x11 (X.Org 1.20.4 ) driver: intel
Resolution: 1920x1080@60.00hz
OpenGL: renderer: Mesa DRI Intel Haswell Desktop version: 4.5 Mesa 19.2.1
coeur-noir@asgard:~$
coeur-noir@asgard:~$ xrandr
Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767
HDMI1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 600mm x 340mm
1920x1080 60.00*+
1600x1200 60.00
1680x1050 59.88
1280x1024 75.02 60.02
1440x900 74.98 59.90
1280x960 60.00
1152x864 75.00
1024x768 75.03 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
640x480 75.00 72.81 66.67 59.94
720x400 70.08
HDMI2 disconnected (normal left inverted right x axis y axis)
VGA1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
coeur-noir@asgard:~$
coeur-noir@asgard:~$ uname -a
Linux asgard 5.0.0-31-generic #33~18.04.1-Ubuntu SMP Tue Oct 1 10:20:39 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
coeur-noir@asgard:~$
For reference, links to forums where I've asked for help. you'll also find there some pictures and things tested so far :
⋅ https://discourse.ubuntubudgie.org/t/supertuxkart-in-18-04-flickering-shadows-with-intel-i915/
⋅ https://bugs.launchpad.net/ubuntu/+source/supertuxkart/+bug/1841953
⋅ https://github.com/supertuxkart/stk-code/issues/4022
⋅ ( french ) https://forum.ubuntu-fr.org/viewtopic.php?pid=22142775#p22142775