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

[Miklós Máté]

On 02/25/2016 01:23 PM, Matteo Bruni wrote:
> 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."
Actually, GL contexts are quite flexible at working with different draw 
buffers, but you're right, it might be incompatible (however, this is 
extremely unlikely). I was afraid that going back to using a tmp context 
would re-introduce the MSAA problem, but it seems that was fixed by my 
patch to Mesa, and not this one :) I should have tested it better. I'll 
post the new patch shortly.

MM