Merge commit '801d0b33e845648866472263263a7001b528c3f4' * commit '801d0b33e845648866472263263a7001b528c3f4': keep a list of visible sorted surfaces
Merge commit '801d0b33e845648866472263263a7001b528c3f4' * commit '801d0b33e845648866472263263a7001b528c3f4': keep a list of visible sorted surfaces