Add a new mode, which attempts to construct a scene exclusively using planes. This is a building block for incrementally testing and constructing state: in the plane-only mode, we test the state exactly once, when we have constructed a full set of planes and want to know if it works or not.
When using the renderer, we need to incrementally test views one by one to see if they will work on planes, falling back to the renderer if not. This test is different, since the scanout plane will be occupied by the renderer's buffer. Testing using the renderer or client buffers may have completely different characteristics, so we need two passes: first, constructing a state with only planes and testing if that succeeds, falling back later to a mixed renderer/plane mode which tests incrementally.
This implements the first mode, and preferentially attempts to use it.
d12e5164 compositor-drm: Add planes-only mode to state proposal
libweston/compositor-drm.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)