[cairo] glitz WGL backend

[Tor Lillqvist]

Tor Lillqvist writes:
 > Today I finally had time to work a bit on the WGL glitz backend
 > again, and after syncing up with the changes to the glx backend,
 > got it to build... I would be very surprised if it would be even
 > close to actually doing anything, but need some testing
 > framework...

Woo-hoo! I just successfully ran the GtkCairo demo program and
rendertest using a glitz WGL backend on Windows.

At least I think they ran successfully... The GtkCairo demo showed a
red square that rotated. Rendertest showed lots of stuff, hard to say
whether it was correct or not. Presumably there are some problems, for
instance I didn't really notice any difference between how the window
looked for the "source (transparent)", "(nearest)", "(repeat)" and
"(reflect)" tests. But at least nothing crashed.

I think there are still some fundamental problems in my WGL
backend. As I understand it (and note that I am in no way an OpenGL
hacker), in WGL, a rendering context is created for a DC, which is
always bound to a "drawable" (window, pixmap or pbuffer). In GLX,
rendering contexts are independent of drawables, aren't they?

Anyway, should I send in the patches to glitz, gtkcairo and rendertest
now, or should I do more testing and verification first?

--tml