this used to be necessary to trigger subchunk creation so that light arrays would be available for use. With 02ff8d671b93ec5911576643e9b03f2049f31c81, this is no longer necessary.
recalculateHeightMapColumn is stateless, so it can't make any assumptions about which subchunks to check for blocks. However, in most the average case (6 allocated subchunks), this causes 2500+ useless SubChunk->getHighestBlockAt() calls (10 per column). Since we're calculating in bulk, we can figure out which subchunks are empty one time and ignore them for all 256 columns.
In the average case, this produced a 50-60% performance improvement for heightmap calculation (~1.1 ms -> 0.5 ms).
In extreme cases where the height is extremely varied, this produces no observable performance benefit, but for most cases with flattish terrain, it's an improvement.
It can likely be further improved, but further performance improvements are outside the scope of this commit and will likely result in more complexity increases.
typically this is a state that only lasts for a tick or so, but it's a race condition that is regardless very commonly encountered.
If you were very unlucky, you might have noticed grass randomly dying when you were spawning or flying around, even though it was in full sky light.
opcache preloading doesn't store non-class constants, but it does store class constants. Class constants that reference non-class constants are pre-resolved into values before storing in opcache SHM, so class constants are OK to use, but non-class constants will come back as undefined.
this was degraded whenever it was I decided to make chunks always be allocated. This commit uses a fast path for light filling in subchunks which are completely clear of the heightmap, which returns the performance back to its old fast levels.
ChunkListeners are less dangerous, and also make more sense considering the usages.
Ideally we want to not have to care if a listener is a Player at all, but that's still some work away yet.
in pretty much every case, these usages really wanted to read the tag's contents anyway, which can be combined with a getTag() and instanceof call for more concise and static analysis friendly code.
In the few cases where the tag contents wasn't needed, it still wanted to check the type, which, again, can be done in a more static analysis friendly way by just using getTag() and instanceof.
this commit removes the ability to replace centrally registered entity classes in favour of using constructors directly.
In future commits I may introduce a dedicated factory interface which allows an _actual_ factory pattern (e.g. factory->createArrow(world, pos, shooter, isCritical) with proper static analysability) but for now it's peripheral to my intended objective.
The purpose of this change is to facilitate untangling of NBT from entity constructors so that they can be properly created without using NBT at all, and instead use nice APIs.
Spawn eggs now support arbitrary entity creation functions like EntityFactory does, allowing much more flexibility in what can be passed to an entity's constructor (e.g. a Plugin reference can be injected by use()ing it in a closure or via traditional DI.
