drm_hwcomposer: add scene flattening
Flattening of a scene is triggered if it doesn't change for a while.
As of now there is a separate thread which triggers flattening if the
scene did not change in last 60 vsyncs.
There are two options for flattening a scene:
* Serial, by using a writeback connector attached to the same crtc as
the one driving the display. This happens only if possible_clones
mask reports that the display encoder and writeback encoder could
work simultaneously.
The steps for achieving this are:
1. Build a commit that enables writeback connector, we don't need to
build a commit that contains the entire active_composition, just
set the writeback specific properties a let the kernel duplicate
the rest of the state.
2. Commit and wait for writeback_fence to fire.
3. Setup a composition with just one plane enabled.
4. Apply the composition if a new one has not been applied meanwhile.
* Concurrent, by comitting the scene to a new unused crtc (state !=
DRM_MODE_CONNECTED) and getting the result back through a writeback
connector.
The steps for achieving this are:
1. Copy layers from active composition.
2. Plan layers of copy on the unused crtc. This is realized by using a
newly created DrmDisplayCompositor object.
3. Commit copy to the unsed crtc and get the result as a drmhwclayer.
4. Setup a composition with just one plane enabled. Re-importing the
buffers might be needed since we might have been using a different
dri node.
5. Apply the composition if a new one has not been applied while doing
the flattening
Signed-off-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe@arm.com>
diff --git a/drmframebuffer.h b/drmframebuffer.h
index 897589c..d4d00bc 100644
--- a/drmframebuffer.h
+++ b/drmframebuffer.h
@@ -65,7 +65,7 @@
}
Clear();
}
- buffer_ = new GraphicBuffer(w, h, PIXEL_FORMAT_RGBA_8888,
+ buffer_ = new GraphicBuffer(w, h, PIXEL_FORMAT_RGB_888,
GRALLOC_USAGE_HW_FB | GRALLOC_USAGE_HW_RENDER |
GRALLOC_USAGE_HW_COMPOSER);
release_fence_fd_ = -1;