Summary:
Updated the old and outdated blur method to use the much more efficient dual kawase blur method.
Now with this we can do virtually infinite blur with very very little performance cost.
The dual kawase blur method is basically downscaling and upscaling an image, but combined with the kawase blur shader.
Comparison: https://i.imgur.com/mh6Cw61.png
Left is old, right is new.
Comparison was done with the strongest blur setting in a VM running on an Intel i7-4790 and a GTX980
We can see here that the performance is even better with this new method.
Reviewers: #plasma, #kwin, graesslin, fredrik
Reviewed By: fredrik
Subscribers: hein, dos, luebking, broulik, romangg, zzag, anthonyfieroni, mart, davidedmundson, fredrik, ngraham, plasma-devel, kwin, #kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D9848
This patch adds an optional texture cache to the blur effect such that damaged windows in
front of the blurred region dont trigger a repaint of the whole blurred region which pretty
often results in a avalanche repaint of nearly the whole screen.
REVIEW: 101977
