[cairo] Inkscape + Cairo

[Krzysztof Kosiński]

Hello

I submitted a GSoC proposal about converting Inkscape to Cairo-based
rendering. I'm not exactly a Cairo expert :) so I could use some help
in a few areas.

1. I want to use hardware accelerated backends when available. Ideally
in the longer term I would like to use cairo-gl on all platforms,
since this would give me the opportunity to implement SVG filter
effects in OpenCL and avoid any read-back using the gl_sharing
extension (also called "OpenGL-OpenCL interoperability"). How can I
create a cairo-gl surface to draw on a GTK widget? Would GtkGLExt help
me in any way? I don't see a way to retrieve a GLXContext from it.

2. Is it at least theoreticaly possible to introduce a cross-platform
API for creating cairo-gl surfaces tied to offscreen pixmaps? I guess
WGL and CGL functions for cairo-gl would need to be added first.

3. Let's say I want to create a sub-surface of some other surface (for
example, to draw only on the part of the image that needs redrawing
after the user changed something in the document). Is
cairo_surface_create_for_region available from applications?

Regards, Krzysztof