Hi everyone, I wasn't aware of these patches, but I'm really glad they are getting some attention, thanks a lot for your review Sima. Given that it's been a while since the patches were emailed, I'm not sure if the original authors of the patches could implement your comments. If not, I can work on it. Please let me know. I'm working on a Mutter feature that'd greatly benefit from this uapi and I'm sure other compositors would find it useful. I'll start working on a new version in a few days if nobody else is already working on it. Best wishes, José Expósito