[compiz] Fragment interface on Intel

[David Reveman]

On Tue, 2007-05-15 at 07:36 +0800, Sam Spilsbury wrote:
> OK. Just to let you know - it most likely IS the fragment interface
> 
> - Water fragmentation worked before the fragment interface was out

OK, I guess those extra instructions that fragment interface adds might
be the cause of this or it could be the changes made to the water
fragment program to make it work with the fragment interface. Whatever
it is, it can be fixed. What someone needs to do is to compare the
different fragment programs generated with and without the fragment
interface and track down what's causing it not to work.

> - Blur seems to be doing something as my framerate slows down to about
> 5fps which sounds about right. (No visible blurring however)

Yes, it's likely doing the framebuffer to texture copying but the actual
fragment shading that produce the blur effect is not possible.

> 
> Is it possible to have water and blur and/or the fragment interface
> not generate more than this limit of fragment operations or is that
> out of the scope?

As the water effect worked before, it should be possible for that effect
but to make the blur fragment code work might not be possible. Either
way, it's not very interesting to try and make the blur code work as
long as glCopyTexSubImage2D isn't accelerated as you wont be able to get
any decent performance without that anyhow.

- David