On Thu, 26 Oct 2006 10:54:18 -0700, Jon Phillips wrote:
On Thu, 2006-10-26 at 12:41 -0400, MenTaLguY wrote:
On Thu, 2006-10-26 at 10:46 +0200, Adib Taraben wrote:
It seems that Inkscape does not export the blur to cairo pdf nor cairo-experimental pdf.
Cairo doesn't directly support blur,
Correct. Cairo does not supply a blur operation.
and as far as I know won't ever.
I've wanted to have a blur operation in cairo for a long time. I regard it as one of the last few "obviously needed" things to have in cairo.
And some of cairo's backends, (such as the XRender-using xlib backend), have filter support which would allow cairo to get access to hardware-accelerated blur when available. So that kind of thing is a very important reason to get this API into cairo rather than forcing applications to drop to software for it.
That doesn't mean we can't do blur with a Cairo-based renderer, of course, but it does mean we'd need to implement it ourselves using an intermediate image surface.
Yes, that's the "drop to software" path. It does exist now, (and will always), but I would hope it would not be the only solution forever.
Basically, we just need someone to cook up a good API that "fits" cairo for supporting blur and other filter types.
The bigger problem is that there's no way to represent blur in PDF. If you want blur in exported PDFs, you'll have to resort to rasterizing blurred objects at some fixed resolution.
Yes, that's a pain. But once we put the blur support into cairo we can at least just solve this once there and every application can use it without having to reinvent it.
cworth, maybe you could chime in on this and the best way to handle this :)
I hope this helps. Here's a pointer to the most recent conversation we (MentalGuy and myself) had about this on the cairo list:
http://lists.freedesktop.org/archives/cairo/2006-March/006577.html
There are some API suggestions there, but we've never seen an attempt at an implementation yet.
Anyone want to give it a try? It would be a very beneficial thing to have.
-Carl