plasma::wallpaper and pure opengl?

[todd rme]

On Wed, Jan 18, 2012 at 6:32 AM, Martin Gräßlin <mgraesslin at kde.org> wrote:
> On Tuesday 17 January 2012 18:49:12 Shaun Reich wrote:
>> i'm not knowledgeable in the OGL department, or the plasma::wallpaper
>> area...but I thought it'd be kind of nice to tinker around with making
>> absurdly useless but awesome wallpapers, and maybe learn a bit of OGL
>> in the process.
> there was recently a thread about OGL wallpapers where I stated my opinion on
> it.
>>
>> problem is, isn't there an issue with using opengl on
>> plasma::wallpapers? because you end up having to render it to an
>> image, then use QPainter to display it, right?
> yes
>>
>> is there a good way around that?
> no :-)
>
> A possible solution might be to take advantage of KWin. Consider Plasma not
> rendering a wallpaper at all and KWin knowing about it. In that case we could
> have a special effect rendering the wallpaper. We already have functionality
> to render the background black if it becomes visible. This would just needed
> to be extended. But it would make mouse interaction and stuff like that
> impossible.
>
> Cheers
> Martin

This may be a bad idea, but would it be possible to have a fully
transparent plasma wallpaper, then render something behind that using
kwin?  The transparent wallpaper could capture mouse and keyboard
interaction, but would not be visible.

-Todd