Steps done:
* Add more velocity with less preconditions.
* Handle push with the player being just above the block where a slime
block is pushed to.
* Exception for vdistrel.
* Breaking:Move verVelUsed from MovingData to PlayerMoveData.
Gameplay issues remaining:
* Still too often fall damage is dealt.
* Friction envelope gets hidden with past-ground being set too often
(vdistsb).
* Potential for more edge cases.
Missing abuse prevention:
* Reinstate invalidation of past entries (currently turned off to
progress at all, will need another iteration).
* More confined preconditions.
* More/better invalidation conditions for velocity set for bounce
effects.
* Less fall damage.
* Flag all velocity added due to slime bouncing appropriately.
* Experimental concept for splitting up velocity, likely to be altered /
removed.
* Add a flag for (faked) pvp velocity.
NOTE: Invalidation of past entries has been deactivated to progress on detecting the stupid past bouncing at all. This will need another iteration.
Lots of issues remain, but vertical push/bounce with pistons is much
improved. Still there are show stoppers (false positives remain, as well
as occasional fall damage).
Use same/similar entry points, like static/classic bounce checking in
MovingListener. SurvivalFly still keeps one exception with the
after-failure Y_POS block move check.
Also check: https://github.com/NoCheatPlus/Issues/issues/5
There are typical cases to cover:
* Extra falling height.
* Fall damage where a slime block had been.
Thus adding a specialized method for bounce (just foot position) instead
of using the full bounds would be better, preferably just check within
the MovingListener (set bounce / adjust velocity there).
Still incomplete, could contain bugs (endless loops, perhaps).
Invalidation
mechanics may need to be refined.
Not covered:
* Exemption for moves resulting from horizontal push/pull.
*
* In case of non-full bounds + variable, allow ground to be found
underneath. Can concern fences (tested on 1.11).
* There has been a probably misplaced/leftover check assuming the block
above to be passable, without checking for it (iMaxY). Since the
access.getMaxBlockY() has already been checked, this part appears to be
not of use, thus iMaxY has been removed from the signature together with
this exception.
If this causes something, please provide debug logs / circumstances :).
This is unfinished, but gives an outlook on what we may be able to do
with this.
* Double doors are not covered (upper/lower half are).
* Interaction with levers / directly with doors is not covered.
* Only doors + gates (not sure what else there is).
* More fine grained configurability is missing (+ only register
listeners if needed).
* Possibly other things.
Tracking BlockRedstone seems to be more promising than BlockPhysics, as
long as we don't have to inspect neighbour blocks to check for door like
blocks at all.
Currently the oldest available entries are used, as if the player had
the maximum allowed latency always. Later on, at least attempting to hit
a global latency estimate (+window) should be attempted.
We'll still have a (moderate) fast-forward implementation to see what
opportunistic checking can do on live servers (elevators, doors etc.).
Intention is to work towards passing stored IBlockCacheNode instances to
methods in BlockProperties, i.e. to have
isOnGroundInAnOverlyOpportunisticWay implemented.
If you need one of the old BlockProperties signatures (or a more
simplified one), just open a GitHub issue.
This is a slightly peculiar change.
* Passing node and nodeAbove is a little bit odd, despite seemingly
efficient at present.
* Later we might need a BlockCache instance that busies about past
states (currently too complicated to implement).
* Uncertain impact (could perform better, could perform worse).
* Possibly left out a couple of places.
* Might have introduced bugs (fast forward).
On the other hand there may be a lot of other types of changes, if we
ever go for a less opportunistic implementation, which can not be
estimated simply, so this may be about the best that can be done, to get
a quick step in.
Already have the signature use IBlockCacheNode for node+nodeAbove, like
it will be done with other methods like collidesBlock.
This will allow calling this with past block states, once other methods
have been adapted as well.
