Xgl server

[Brian Paul]

David Reveman wrote:
> I've been doing some work to get an X server running on top of
> OpenGL/glitz and I've got something that works pretty well now. I stuck
> the code into the "xserver" tree and './configure --enable-xglserver'
> should compile the common xgl code along with an Xglx server that can
> run on top of an existing X server with GLX.
> 
> With a good OpenGL driver and some luck, you should be able to run most
> applications on it. However, you should know that the Xglx server is
> really simple, there's no real cursor and compared to the Xnest server,
> Xglx must always run on top of all other windows as the back buffer is
> used for pixmap memory.
> 
> There's a screenshot from running a complete gnome desktop on top of
> Xglx here:
> http://www.cs.umu.se/~c99drn/pics/xgl-shot.png
> I was actually running Xglx on top of software mesa when I took that
> screenshot. That's of course quite slow, but not completely unusable. :)
> 
> A lot of operations are accelerated, some operations can be accelerated
> better, some operations are not accelerated but can be accelerated and
> some operations can never be accelerated.
> 
> Here's a list of things that I think most importantly need some work:
> 
> * Get the fb layer to operate on pixel data with scan-line order
> bottom-to-top. This will make software fall-backs A LOT faster. As
> keithp told me, all we really need to do is to use negative strides and
> I'll give that a try within in a few days, hopefully that will work just
> fine.

Why do you need bottom-to-top raster order?  I assume it has something 
to do with OpenGL's conventions.


> * Replace or improve the current xgl offscreen memory manager, it wastes
> huge amounts of memory right now.
> * Improve xrender text performance.
> * Accelerate bitmap text. Performance of applications that use bitmap
> text is terrible right now. :(
> 
> The following things could also needs some work. They are probably not
> as important but they would be interesting and fun to get working:
> 
> * Hook up glitz's convolution filters. This should be really easy, all
> we need is a software fall-back.
> * GLX and accelerated indirect rendering.
> * Add Xagl and Xwgl servers.
> * Add a miniglx or mesa-solo server.
> 
> Have fun playing with it. If you find any bugs (and you will), please
> let me know.

Nice job!

-Brian