Add the missing feedback flags to the Presentation extension protocol
specification.
These flags are slightly different from the previous RFCv3.1 definition:
http://lists.freedesktop.org/archives/wayland-devel/2014-March/013598.html
Now, all compositors are safe to use 0 as the flags if they don't bother
setting them properly. 0 is the "worst case" with the least guarantees.
The meaning of ZERO_COPY is not exactly the opposite of the old COPY
flag. ZERO_COPY is more strict, but applies only to that one surface.
Therefore it can be used to verify a zero-copy video playback pipeline,
also to a hardware overlay.
There is no longer a flag to clearly indicate if the final presentation
was done by a copy or a page flip. ZERO_COPY forbids the copy, but VSYNC
alone does allow copy in case it cannot tear. It is possible to have
first a compositing pass, and then another copy into the frontbuffer,
and still set VSYNC if it cannot tear. Usually "cannot tear" is too
hard to guarantee with a copy, so it often implies a page flip.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Tested-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Pekka Paalanen
0de22a38e6