[Bug 1069498]

[Pgriffais]

Hi Thomas,

The problem with glWaitVideoSync() is that it waits on the CPU, so any
interval of time can happen between performing that wait and issuing the
blit, which means tear-free presentation isn't guaranteed.

We briefly discussed this with Fredrik a few days ago, and contrary to
what I said GLX_EXT_buffer_age isn't yet exposed on current 310 drivers
(as you found out). However we should be rolling out a new release
series shortly, which will include support for it.

The intention behind the change you linked is good, but without the
functionality provided by  GLX_EXT_buffer_age you have no guarantees
about how many buffers are in the flip queue of the driver; it's usually
a trivial cycle between 2 or 3 buffers depending whether Triple
Buffering is enabled, but other implementations might have their own
specific flipping mechanism.

Thanks,
 - Pierre-Loup

-- 
You received this bug notification because you are a member of Kubuntu
Bugs, which is subscribed to kde-workspace in Ubuntu.
https://bugs.launchpad.net/bugs/1069498

Title:
  KWin shows tearing despite of VSync

To manage notifications about this bug go to:
https://bugs.launchpad.net/kdebase-workspace/+bug/1069498/+subscriptions