At 10:14 AM 10/21/99 -0700, [EMAIL PROTECTED] wrote:
>
>Good question. If everyone is convinced that context-independent
>pointers can be supported with acceptable cost (for driver development
>and for execution at runtime), then we're done; we can take the
>details offline. If there's a sizeable group of people who are not
>convinced, then we need to keep going a while longer.
My concern is not whether or not we can implement a context-independent
dispatch with minimal overhead, since I'm fairly sure we have the
collective brainpower to accomplish this. My concern is more with the fact
that we need to devote energy to minimizing the performance impact, and
must concoct an elaborate and potentially error prone scheme to accomplish
this, and that context independence isn't a large enough win to justify
this distraction.
Further, I am interested in a scheme which can work cross-platform, and it
has already been demonstrated that context independence cannot (reasonably)
be achieved on Windows.
On a related note, Allen pointed out yesterday that my sample
application-level per-context data structure which contains such things as
the per-context extension pointers is not accessible from a general purpose
rendering library. While this is true, I must point out that (and I think
Steve Baker mentioned this first) the library itself needs to know whether
or not an extension is supported before it can call a context-independent
function pointer, and therefore is required to maintain similar per-context
state. I still don't see how context independent pointers solves this
problem, and if we cannot solve the whole problem its fruitless, nay, even
misleading, to solve half of it.
Perhaps, Allen, its time we go to lunch and work this out. Anyone else for
a cheesesteak? =)
-- Michael
