dual_kawase Blur does not work with --backend glx #43
Description
Platform: ArcoLinuxB 20.4.10
GPU, drivers, and screen setup: Sapphire Pulse Radeon RX 5600 XT, rounded corners fork of i3wm, dual monitors set up with xrandr.
Compton version: vgit-c67d7
Compton configuration: https://pastebin.com/MWthVngz
Steps of reproduction
In i3, try using dual_kawase blur with glx backend.
Expected behavior
According to the README.md here at this fork, dual_kawase blur "only works with --experimental-backends and --backend glx". However, with glx set either at runtime through --backend or in the picom.conf config file, there is zero blur. Transparency still works, so picom itself does in fact launch, but there's no blur whatsoever.
Current Behavior & Other details
With --experimental-backends, dual_kawase DOES in fact "work," but there are so many glitches and artifacts and just plain ugliness, that it's unusable. Here are a couple examples, one is of a terminal, and another is of this very window I'm currently typing in:
Pretty much every window that doesn't have focus looks like this, and I've tried killing and restarting it multiple times. So I wanted to try glx as the backend to see if that helped. The glitches go away, but there's zero blur.