Is it possible to render into memory on win32/gtk?

[Benjamin <thronerbe gmx de>]

first i would like to say hallo, I've just subscribed to this list a few 
minutes ago.
although I've read a bit over it, because I'm looking for a solution for 
a hard-to-crack-nut.

So now my question:
   i need to render gtk into some sort of memory buffer, to feed it 
into OpenGL
   (or whatever). Linux-fb don't seams to be an option, because to 
compile gtk
   on win32 is simply a pain (after ours of modifying makefiles i got 
just a bunch
   of crashing dll's and exe's), and if i can't compile (what is surely 
my fault, but i
   don't have the time to probably reinvent the wheel), it is 
impossible to debug.
   DirectFB seams to be a solution that is close to what i want, but 
still no win32
   support (?). I've played a bit around with that pixbuf-stuff, and 
was able to get what
   i wanted but there are still allot of problems:
      1.)on win32 gtk is rendered using the ms-gdi, what is not that 
slow. but i need to render
      just to the GDI-surfaces not on screen. (probably just hiding th 
window using win32-api calls)
      2.)i need to hijack the input system. again win32-api hacks could 
work
      3.)works fine just for a single window, because of all that 
api-hacking i don't use win32 as the window
         manager anymore.->i could probably write my own one.

   as you can see, I'm ending up with allot of hacks, that are every 
thing else than portable. what i want is a
   back-end that provides me an api to copy the rendered off-screen 
image to whatever i want and some simple
   functions that i call from my application to feed gdk with input 
events. so, does have anybody have an idea
   if something like that already exists???

thanks in regards, i hope all that is not to much off-topic.

Benjamin