[compiz] Blurring behind windows

[David Reveman]

On Wed, 2007-01-03 at 02:47 +0000, Mike Dransfield wrote:
> It is a common request and I think it can
> be useful.  The problem with beryl blur is
> that it is way too slow.
> 
> I haven't poured through all of their code
> but I strongly suspect that there is some
> intensive code to work out where to blur.
> 
> I would be happy with just a basic blur under
> transparent windows.
> 
> Is there anything that can be done in the core
> to make effects underneath transparent windows
> easier?   The other problem with the blur was
> that 100% transparent parts of the window were
> blurred so corners of the windows had strange
> looking blurring.
> 
> There is a basic blur plugin here, all my attempts
> to get it working have failed so I would welcome
> any tips.  Could the core be changed to support
> these blur functions?
> 
> http://forum.go-compiz.org/viewtopic.php?t=207
> 

I will be adding a blur plugin to the main compiz repository at some
point. That's a promise.

I did have a quick look at an existing blur plugin some time ago but it
contained a lot of code and many alternative code paths for something
that I like to have a simple and easy to maintain solution for.

I'll implement my own blur plugin from scratch soon unless someone
presents a simple straight forward plugin that can do the job.

I pretty sure no changes to the core should be needed to implement a
simple, efficient blur plugin. However, I don't like to add another
programmable fragment processing plugin before we have proper way to
make these type of plugins work together. So to make the blur plugin
work at the same time as the water plugin and any other plugin that's
modifying the fragment processing stage, changes to the core are needed.

I'll try to get and initial version of this fragment processing
interface done soon. Once it's done, implementing a blur plugin
shouldn't take too long.

-David