[HOpenGL] Extension problem (narrowed)

[Sven Panne]

Yann Morvan wrote:
> I have been playing around with the extension wrapper and I feel like I am
> missing something. [...]

Me too... :-( Some months ago the extension mechanism definitely worked on
WinDoze, but I haven't tried this for a long time. Is there anybody on this
list with a GHC from HEAD on WinDoze who can comment on this issue? I'll try
this for myself, but I'm currently quite busy with my "real" job, so don't
hold your breath for this...

> I was wary of the unsafePerformIO in there,
> I hope the difference is irrelevent. If it is, tell me why. [...]

The unsafePerformIO is a performance hack, ensuring that for any extension entry
is only queried once, not for any call. Technically this is a bit incorrect,
because queries for an extension entry might depend on the current OpenGL context
(of which there could be many), but unless you use a multihead configuration I'm
not aware of any driver actually returning different addresses in different contexts.
Perhaps I'll revise this hack some day... Nevertheless, this doesn't seem to be
the cause of your problem, because you use getProcAddress correctly.

Cheers,
    S.