Bug 288526

Summary:	WISH: enable blur for xrender
Product:	[Plasma] kwin	Reporter:	Antonio Orefice <kokoko3k>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal
Priority:	NOR
Version First Reported In:	4.7.3
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Antonio Orefice 2011-12-09 10:03:04 UTC

Version:           4.7.3 (using KDE 4.7.3) 
OS:                Linux

I know xrender doesn't support blur, but it is able to do alpha blending and scaling, so there are at least 2 ways to obtain a blur effect.

The first is that if you alphablend 3/4 images shifted by 1/2px togheter, you can easilly obtain a slight blurred image.

The other is to scale the image to a very low resolution and then rescale it to the original one, the resulting picture will be a blurred version of the original.

Judging from the resize effect lightness under xrender, the second method should be very very fast, maybe uglier.

Please, consider it!

Reproducible: Always


Actual Results:  
 

Expected Results:

Comment 1 Martin Flöser 2011-12-09 10:11:39 UTC

Have a look at http://kde-look.org/content/show.php/BeDistorted?content=126906

Apart from that we do not have any plans to support blur under XRender. If a user wishes to use blur, he has to use OpenGL. This is completely acceptable as it is in general only an additional user experience feature provided for users with capable hardware. XRender does not provide the requirements for blur which we have.

Comment 2 Antonio Orefice 2011-12-09 10:15:11 UTC

Oh, i just missed that, thank you|

Comment 3 Martin Flöser 2011-12-09 10:21:17 UTC

Please do not reopen the wish after a decision has been done. Thanks

Comment 4 Thomas Lübking 2011-12-09 10:47:32 UTC

FTR:
BeDistorted won't work or even compile on 4.7 - i'll have to port it first.