[Cairo] Color transforms

[David Forster]

On Thu, Jul 17, 2003 at 12:05:56PM -0700, Bill Spitzak wrote:
> > One idea that should be possible with this approach is graphics
> > operations using surfaces from separate devices, (think compositing
> > images from two different X servers for example). That could be a lot
> > of fun if we can get it to work.
> 
> That would be a really good idea. It seems this would require Cairo
> to have a "return this area as an image" call. The "composite from A
> to B" call would actually call B's device. It can then detect if A
> is something it can talk to directly, and if not it calls the
> portable "return this image" call and then uses the result as the
> source.

Perhaps instead of returning an image, B could be given a surface A'
that is compatiable with A and render itself to A' using Cairo.

For example:

A  = Xlib surface (Drawable)
A' = Xlib surface (Pixmap)
B  = SVG buffer (just to take a break from PostScript ;)

No need to upload a bulky image to the X server, it'll be rendered
efficiently through Xlib and compositing A and A' can happen through
RENDER.

Now, if B where actually an SVG stream that could not be rewound,
there could be trouble...

-Dave