[Xorg] Re: X on OpenGL

[Ian Romanick]

Andy Sy wrote:

> My main worries are that 2D operations might be klunkier or less
> efficient (considering the horror stories I've heard about the
> performance of glXXXXPixels()) to execute using the OpenGL API.

Basically we have a chicken and egg problem.  People are hesitant to use 
OpenGL for the windowing system becuase certain parts of it are slow. 
Other people are hesitant to make certain parts of OpenGL fast because 
they're rarely used.  Keep three things in mind:

1. As the windowing system develops, we can make whatever optimizations 
are needed in the windowing system or in the open-source 3D drivers to 
make things fast.

2. Which paths are fast in a particular vendor's driver is 100% market 
driven.  If the market starts demanding fast glDrawPixels or fast 
convolution filters, the IHVs *will* implement it.  They may not do it 
right away, but if it will give them a competitive advantage in a given 
market, they'll do it.

3. If we get some distance down the path of doing the windowing system 
on OpenGL and realize that OpenGL is missing some feature that would 
make things faster / easier / better, we can make an extension that 
implements that feature.  If you're worried about IHVs supporting it, 
see point #2. :)

This really *is* a tractable problem.  If our only worry is about being 
able to use some API to access functionality of the hardware, the only 
variable is how much code we want to write to do it.