[FIXED!] tearing in sdl (GL) apps

Question

Problem:
If you have compositing extension enabled, sdl 1.2 based opengl apps will produce tearing unless you manage to disable backing store.
Causes:
* In the past SDL relied on the environment variable: SDL_VIDEO_X11_BACKINGSTORE to enable backing store functionalities.
* Now SDL asks X server if it supports backing store extension, and X server says "YES!" even if backing store is disabled in xorg.conf, but composite extension is enabled.
Solution:
The arch sdl package now has the patch, so this thread is useless.
Install https://aur.archlinux.org/packages/sdl-nobackingstore/
it will bring the environment variable functionality back into sdl and disable backing store by default.
if you want backingstore back, then run (before launching the sdl app):
export SDL_VIDEO_X11_BACKINGSTORE=1
if you want to disable it again, or you want to be sure it is disabled, run (before launching the sdl app):
unset SDL_VIDEO_X11_BACKINGSTORE
References:
https://devtalk.nvidia.com/default/topi … disabled-/
https://bugs.freedesktop.org/show_bug.cgi?id=74158
https://bugzilla.libsdl.org/show_bug.cgi?id=2383
Last edited by kokoko3k (2014-09-28 07:11:20)

Answer 1

Xenphor wrote:This problem affects mame as well but the package fixed it.
I'm not an expert when it comes to patching system or kernel. I have a question - i need only to install this package from aur by yapurt -S <package name> and it will be fixed? In post number one this is the suggested metod. I would like to be sure of what i'm going to do.
Also, this tearing is in sdl apps - smplayer, for an exmaple? Video tearing?
Last edited by firekage (2014-05-13 09:17:02)