[PATCH 1/2] opengl: don't create a tmp context for glCopyTexImage2D

[Matteo Bruni]

Ah, I think I see now why this is using a temporary context: there is
no guarantee that the current GL context is compatible with the
pbuffer.
That means a glXMakeCurrent() for the pbuffer and the current context
might fail thus a temporary context is probably necessary in the
general case after all.

There is no reason to create a new context each time
wglBindTexImageARB is called though. You could store the temporary GL
context into struct wgl_pbuffer and reuse it for all the following
calls with the same pbuffer (as long as the current context stays the
same - if it changes the temporary context needs to be recreated so
that it's shared with the "new" current context). The temporary
context will have to be destroyed when the (WGL) pbuffer is destroyed.

When you're resending please change the patch subject to something
like "winex11: Don't create a temporary context each time
X11DRV_wglBindTexImageARB is called."