[compiz] patch for colored drop-shadow

[David Reveman]

On Tue, 2006-04-25 at 20:28 +0200, Mirco Müller wrote: 
> Greetings everybody!
> 
> 	Here's a patch (against compiz from CVS-head about 30 min. ago) that
> adds a shadow_color option to the parameters of the decoration-plugin. I
> only needed to add a few lines to decoration.c and
> gnome-window-decorator.c. The only thing missing is the compiz.schema. I
> dare not touch that XML-file manually. So after you applied the patch,
> recompiled compiz and restarted g-w-d and compiz you'll have to fire up
> gconf-editor and add a string-parameter with the name shadow_color
> yourself.
> 
> 	You can use the normal HTML-like syntax for defining the wanted color:
> 
> 	#fff or #ffffff -> white
> 	#f00 or #ff0000 -> red
> 	#f73 or #ff7733 -> orange


Patch looks OK, I'll add it if people think this functionality is
useful. I don't want to add options just because we can.

> 
> 	You get the idea. If you don't follow this scheme your setting will be
> ignored. Note that there's no alpha/opacity value used. This is left
> untouched. There's already the option shadow_opacity for this. BTW, it
> takes a moment for the changed setting to apply. I don't know if that's
> normal. David what's your call on this?

It's busy computing the shadow. Shadows are generated by using large
convolution filters and the necessary computations take some time to
finish. Greater radius means greater convolution filter..

However, I'm using a separable gaussian blur filter so we can just run
two passes with a 1D filter instead of one pass with a 2D filter and it
should be much faster.

-David