[Qemu-devel] OpenGL idea...

[Qemu-devel] OpenGL idea...

[Chad Page]

	Would it be possible to create a thunk "library" that is linked to
the application in place of the x86 library?  If so then one could be made
to handle the OpenGL calls and pass them onto the native DLL.  This would
in theory enable accelerated OpenGL... unless there's something else I'm
missing...

	- Chad

Re: [Qemu-devel] OpenGL idea...

[Lionel Ulmer]

> 	Would it be possible to create a thunk "library" that is linked to
> the application in place of the x86 library?  If so then one could be made
> to handle the OpenGL calls and pass them onto the native DLL.  This would
> in theory enable accelerated OpenGL... unless there's something else I'm
> missing...

This could work (ie to basically have most GL calls be like syscalls). The
problems are :

 1) you need to do parameter conversions for all API calls. Which are pretty
    easy for most of the core APIs, but will be a pain for textures, vertex
    buffers.

 2) OpenGL, for thread safety, relies on the way the underlying system does
    threading. For example, I know that the NVIDIA drivers, when NPTL is
    built in, use some special storage in the TLS space for their datas.
    Now, if QEMU emulates 'target' threading all in the same 'native' thread
    (ie you do not have one target thread == one native thread), this won't
    work as all GL calls will be on the same thread (note that
    multi-threaded GL apps are pretty rare out there :-) ).

 3) if X is emulated and GL is native, how are you going to get all GLX
    calls working ?

These are the problems I see... Maybe they have easy solution though, I did
not think too much about this :-)

           Lionel

-- 
		 Lionel Ulmer - http://www.bbrox.org/