This is a first version without any safeguards and without any settings.
A player who has any meta data for 'nocheat.exempt' is regarded exempt
from all checks. Suggestion is a boolean value (true), but setting
anything will do for the moment. Later String values or List<String>
might be supported to allow some kind of generic categories for
exemption (to be discussed with skill plugin developers).
This is not meant for permanent marking, but rather for "extra" events
like area damage with entity.damage(amount, damagerPlayer). The plugin
setting the metadata should also remove the metadata. In order not to
remove all protection by NoCheatPlus, plugins should fire extra events
or cancel events on a higher priority level than EventPriority.LOWEST.
To be continued:
* Relating to the 'allowed base distance' for horizontal moving allows
to judge speed without taking friction or bunny-hopping into account.
* Make use in bunny hop (seems to make 2-high ceiling + sprint jump a
little better).
* Later more workarounds should be confined to a minimum, using
MoveData.
* Namely walkSpeed, downStream.
* SurvivalFly: Alter method signatures to use thisMove rather.
* MoveData: Only initialize the necessary minimum.
* Add MoveData.alwaysInvalidated, to indicate random future purpose.
Should only be possible to happen, if an actions entry doesn't use 'ncp
delay ...' for teleporting, or if a hook teleports the player (both
discouraged).
Does break use of MovingData for last coordinates and distances (not
officially exposed API).
Other changes:
* Position resetting on teleport events has been altered.
* Some blocks/methods are guarded by checking for lastMove.toIsValid.
* Possibly other.
Also:
* Rename the walkSpeed constant to WALK_SPEED (nuisance to mix up).
* Alter conditions slightly in some places by using
thisMove/lastMove.headObstructed.
Issues remaining:
* Moderate speed increase with yDist 0 and hDist like 0.35 -> 0.45.
* Transitions head blocked -> not, can trigger hspeed violations.
* Remove extra conditions for from.isHeadObstructed in vDistAir.
* Account for yDistance in more places. Use the maximum of the default
margin and yDistance.
* Add a tag for not setting low jump, due to the head being obstructed.
Fixes:
* Issues with 2-high ceiling with normal ground.
Issues remaining:
* Ice floor + 2-high ceiling.
* Jump/bunny with head blocked, moving to where the head is not blocked.
There is a small chance that other plugin cancel these events. Since the
server ignores event.setFrom for cancelled events and also won't fire a
teleport event, this remains a problematic case.
Represents the first "simplistic" approach to block change tracking,
only attempting to make vertical push/pull work.
It seems that we need to add on-ground checking accounting for piston
moves as well, otherwise anything with pistons retracting will lead to
survivalfly violations. Pistons extending and retracting may also
randomly move around players, including dragging them into the piston
block with the bounding box (not center of player).
In order to make on-ground work, we might need to check in another
place, possibly check where resetFrom an resetTo are set. Performance
questions might remain, there might also be a slight redesign necessary,
in order to run some sub-routines more side-effect free, to check
several branches, including after-failure checking.
* Default order: order of first put (first put is first on iteration).
* Fix order being done right for all cases.
* Fix linking.
* Override clear.
* Add more tests.
* Below 1.7 allow ground-to-ground hop with moderate speed. Might be
there is more speed possible, shortly tested on 1.6.4.
* From 1.7.10 on, hitting the jump envelope or having the head
obstructed is demanded.
* The GROUND_HEIGHT flag indicates, that players are on ground (and can
walk on) from getGroundMinHeight on, once a block collides. Thus an
extra case for isPassableWorkaround is necessary.
* Set GROUND_HEIGHT for ENDER_PORTAL_FRAME, return the minimal height of
the ENDER_PORTAL_FRAME block for getGroundMinHeight. (Also add XZ100,
just to be sure.)
