From: James Simmons <jsimmons@edgeglobal.com>
  To  : ggi-develop@eskimo.com
  Date: Mon, 9 Aug 1999 09:36:46 -0400 (EDT)

Re: Matrox GGI accellerator

> > > That is one point, where the SGI HW helps ... Individual windows have tags
> > > in the graphics RAM that can be regarded as a kind of "stencil-mask" for
> > > such clipping purposes.
> 
> > That would be the hardest part to work. Like I said this is far down the
> > road. 
> 
> It cannot be done without hardware support. You have only two choices on
> that matter:
> 
> 1. Do not allow direct mapping of video RAM. Always go through an accel
> protocol, which you can clip in software.
> 
> 2. Accept the possibility of "crosstalk" between the windows and eventually
> between the window and the root window. As I outlined, this is not a real 
> concern with X windows anyway, as one can mess up the screen "legally" by
> creating new windows or drawing on the root window as well.
>


Then how do you suggest we handle the following situation. I'm running two
OpenGL programs in X windows. I don't want process one being able to
write into process two z buffer.