[cairo] Where's the bottleneck in using glitz/cairo/librsvg?

[Alexander Larsson]

On Thu, 2006-06-15 at 01:28 -0700, Jamey Sharp wrote:
> On Thu, Jun 15, 2006 at 09:50:15AM +0200, Alexander Larsson wrote:
> > Maybe we could add a render primitive similar to the trapezoid one that
> > allows you to send a bunch of spanlines (stored in some compact way).
> > That way a non-tesselating software rasterizer can still be fast on
> > remote connections.
> 
> I'm no expert on graphics, but I've put a bit of research and
> development effort into X network performance. :-)
> 
> It seems to me that run-length encoding a rasterized image will get you
> almost as compact as a bunch of spanlines. I'd think gzip compression
> would do as well or better than RLE. If both are true then `ssh -C`
> should suffice, rather than introducing a new request.

While that might be true for general images I doubt it is the case for
e.g. a rasterized one-color polygon. In most case almost all lines in it
will only be 1 pixel alpha, 1 span opaque color, 1 pixel alpha. The
server can then composite these spanlines very efficiently against the
background.

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 Alexander Larsson                                            Red Hat, Inc 
                   alexl at redhat.com    alla at lysator.liu.se 
He's a jaded amnesiac werewolf She's a psychotic green-skinned barmaid from 
out of town. They fight crime!