[Bug 34166] Fullscreen flickering on Mac

http://bugs.winehq.org/show_bug.cgi?id=34166

--- Comment #25 from Henri Verbeet  ---
(In reply to comment #15)
> (In reply to comment #13)
>
> Now Apple is asking me this: "Are you rendering to the front buffer but
> expect it to be defined?"

Well yes, I don't think rendering to the front buffer is somehow inherently
unreasonable. (Or why even bother providing single buffered contexts?) I think
Ken explained the issue pretty well in comment 4, but here's another try:

For the affected applications, we have a double buffered GL context, but only
ever render to the front buffer. For some reason the (uninitialized) contents
of the back buffer get copied to the front buffer without us calling
[NSOpenGLContext flushBuffer] / CGLFlushDrawable(). This seems to only happen
while in fullscreen mode.

For good measure I'll also explicitly mention that we're not reading from the
front buffer and expecting any particular result, expecting the back buffer
contents to be defined after a buffer swap, or anything silly like that, and
that this all works fine on every single other OpenGL implementation we're
aware of, including MacOS versions before Lion.