Default implementation of NSOpenglView::update is not safe because it
just calls update on the opengl context whereas we are not in the gl thread.
Also fix the white flickering when resizing, because now we need to call
the draw callback manually when resizing.
- All gstglwindow members are now modified only in the gl thread
to avoid thread concurrency
- OpenGL context is now properly clean
- fix a couple of things in implementation of xoverlay interface
It works with both gst-launch and a cocoa app (non-embedded and embedded)
But there is still some problems:
- sometimes crash when closing
- flickering when resizing
- embedded mode not perfect
I will first make the CMake build work with cocoa backend
in order to generate a XCode project.
Then it should be easier to fix those issues.
The external opengl context must be specify when creating
our OpenGL context (glx) or just after (wgl).
When calling glXCreateContext or wglShareLists, the
external opengl context must not be current.
Then our gl context can be current in the gl thread while
the external gl context is current in an other thread.
See tests/examples/clutter/cluttershare.c
