[sugar] icon assistance/validation

[Gary C Martin]

On 18 Mar 2008, at 20:13, Eben Eliason wrote:

> I can remove the stroke-opacity altogether.  As mentioned before, I
> don't have any particular goal in mind with respect to that
> property...I just implemented it at the same time as fill-opacity
> because it was easy to add.  I do want to keep the fill-opacity so we
> can take advantage of it in the future, though.  It is something that
> may not be implemented immediately, but would make the code much
> cleaner once we are able to support it.

What would happen to overlapping fill areas if opacity starts getting  
fiddled with? My understanding is that the overlap areas will be  
additive and there for more opaque than non-overlapping areas leading  
to fuggly shapes appearing. Icon designers would need to always build  
all non trivial fill shapes out of little bits of non-overlapping  
primitives. That's quite a tall order.

If there really is some great feature that needs alpha, can the SVG  
not just be rendered in to a pixbuff, and then the pixbuff be  
composited into a widget with alpha. This way the SVG is 'flattened'  
so that you can dial up/down the transparency across the whole image  
without fuggly bits appearing.

I'm currently using transparency like this in moon activity – I just  
happen to be starting with a jpg image (that I need transparency  
effects on), rather than an SVG resource. I then do some compositing  
to form the dark and light sides of the Lunar phase, out of one full  
bright jpg image. Now it's not too quick on XO hardware (about 1sec  
all said and done), but then again it is a 726x726px image going  
through several alpha/masking composite stages, you should be able to  
composite 55x55px oooh ~170 times faster. It's currently all pure GTK+  
at the moment, but planning a move to Cairo for more transparency  
control (would like soft shadows at least) and perhaps better  
performance.

Do you want me to make a pulsing SVG like this as a little test  
activity? See what the load is like or if there are technical bumps  
preventing it?

Regards,
G