HullHider gets a hideEntities parameter: the fight still hides entities inside
hidden hulls, /hullhider only hides blocks. As the TechHider also dropped
spawn packets at hidden positions, ForPlayer#canAccessEntitySpawn decides
about them now, which the BauTechHider always allows.
/hullhider hides the inside of the build area hull of a region from the
players who toggle it, like the hull hider of a fight. Each region gets its
own hull while somebody uses it; it is rebuilt every time somebody enables it,
as WorldEdit and Axiom changes do not update it. /techhider, /xray and
/hullhider exclude each other per player and region.
Which players may see the hull contents is now decided by Viewers, a sealed
class with HiddenByDefault (fight) and VisibleByDefault (bau). Added players
are stored in a set; isViewer alone defines what being added means.
The new TechHider registers a permanent global filter, so BauSystem now uses
a single BauTechHider that combines the hiding rules of the spectator
techhider, /techhider and /xray per player. To support the different
obfuscation blocks of these rules, ForPlayer now provides the obfuscation
block per position.
The ChunkHider now also checks single valued chunk sections, which were sent
unfiltered before, and recalculates their block count if they change.
Unhandled packet types are logged once; statistics, debug samples and ping
responses are passed through.
The legacy TechHider and its access widener entries are removed.