[Development] Late API addition in QScreen for 5.0

Samuel Rødal samuel.rodal at nokia.com
Wed May 9 09:18:03 CEST 2012

On 05/08/2012 09:01 PM, ext Fredrik Höglund wrote:
> On Friday 04 May 2012, Samuel Rødal wrote:
>> On Linux, it's all up to the graphics driver in my experience. With the
>> binary Nvidia driver the only reliable way I've seen of enabling vsync
>> has been to do "export __GL_SYNC_TO_VBLANK=1" before launching an
>> application. AMD's Catalyst control panel now has an option called "Tear
>> Free Desktop" which is supposed to also sync rendering, but when I've
>> tried it I've still gotten tearing, just now it's in the same location
>> each frame, which looks even worse.
> Doesn't the NVIDIA driver respect the swap interval set with
> glxSwapInterval()?
> I would expect the environment variable to set the default interval
> to 1, or override any attempts by the application to set it to 0.

Like I mentioned earlier, when I've used glxSwapInterval() the driver
has overall synced with the display refresh, but slightly out of phase,
causing tearing in the same location each frame :/

Might not be the case for all drivers though, or even any drivers these
days, it's been a while since I tried this.


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