Re: Let's just build it and see how it works!

Jon Smirl wrote:
> Prototyping this can be done on several parallel paths....
> 
> 1) Trying out xserver on the OpenGL API. The quickest path to this is to use the
> proprietary ATI (or maybe NVidia)implementation under XFree86. The ATI
> implementation has working pbuffers. pbuffers support is needed to get
> accelerated drawing to offscreen windows. This can be done on any recent
> ATI/Nvidia hardware.
> 
> 2) Bringing up a standalone OpenSource platform. The quickest path here is the
> fbdev miniglx implementation of software Mesa. What it is missing is general
> pbuffer support in Mesa.

pbuffers is more of a driver/GLX issue than a Mesa issue.  BTW, Mesa's 
s/w xlib driver supports GLX pbuffers.

Driver-wise, we just need a way to allocate video memory for the 
color/depth/stencil buffers then tell the hardware to draw into it.

For the miniglx interface, we'd also have to implement the GLX pbuffer 
API (or something equivalent).

The last useful piece would be to use pbuffers as texture images. 
This is also known as 'render-to-texture'.  There's a WGL spec for it, 
but not for GLX.


> 3) Bringing up a standalone accelerated OpenSource platform. The quickest path
> here is the existing Radeon miniglx driver. This driver needs the fbdev driver
> to get it's modes, but that works. What it is missing is pbuffer support in the
> radeon DRM module. 
> 
> 4) Bring up a full Radeon driver. This is what I'm working on. My driver can
> load without a config file (done with changes to the DRM module) and it has full
> mode setting support. It doesn't need fbdev. I just have to finish de-Xifying
> 100KB of code.
> 
> I don't know everyone's schedules or if you're even interested, but this could
> be done in a week or so (plus Thanksgiving time) by utilizing people already
> familiar with the code. keithp/brian might be best for #1. brian for #2, keithw
> for #3. And I'll do #4. EricA can help keithw and I out with the DRM changes.
> Other people might chip in with hardware support for other cards.

I'll try to find some time to look into pbuffers for miniglx/Mesa.  No 
guarantees though.

-Brian