shm: support textures of 3 bytes-per-pixel
Adds support for BGR888 and RGB888. Some clients use it and we just fail to render them, making devs thinking that kwin is broken.
Signed-off-by: Victoria Fischer victoria.fischer@mbition.io
Tested with (needs to be newer than 1.22):
gst-launch-1.0 videotestsrc pattern=red ! "video/x-raw, format=RGB" ! waylandsink
gst-launch-1.0 videotestsrc pattern=red ! "video/x-raw, format=BGR" ! waylandsink
Edited by Aleix Pol Gonzalez