New blurry feature makes my laptop slow

[tintou]

What Happened?

When the modal dialog appears that triggers the background being blurry, the interaction becomes really difficult as everything becomes sluggish

Steps to Reproduce

1. Open the shutdown dialog
2. Try to click on element in the shutdown dialog
3. Everything is very slow

Expected Behavior

Everything should be smooth

OS Version

8.x (Circe)

OS Architecture

amd64 (on most hardwares)

Session Type

Secure Session (Wayland, This is the default)

Software Version

Latest release (I have run all updates)

Log Output

Hardware Info

12 × Intel® Core(TM) Ultra 7 155U
Intel® Meteor Lake-P [Intel Graphics]
32GB of memory

[leolost2605]

I guess we could for now disable it when reduce transparency is on, even though it doesn't quite apply here? Would be a quick fix.
I had a look and seems like Clutter.BlurEffect (which AFAICT our BackgroundBlurEffect uses) uses a gaussian blur via Clutter.Blur. Maybe we could instead use a faster blur for things like that? It explicitly says with low blur radius it can easily half the frame rate. Not sure whether 10 is a low blur radius? Maybe @lenemter has some input here or suggestions of how we can speed it up?

[lenemter]

Hmmm... I'll see what I can come up with

[lenemter]

For modal dialogs we can make a screenshot and blur it, instead of redrawing bg every frame. Not ideal, but should work

[lenemter]

Or we can increase blur radius