This story dates back to the days when getVariantBitmask() was introduced. The purpose of this function was to allow the variant info to be extracted from the metadata, for use with item drops. This was later changed to state bitmask for reasons I don't clearly recall.
In the great 4.0 refactor, we now store variant magic numbers separately, so we don't need any generic bitmask to split up variant and state information anymore. Variant is now only ever serialized and never deserialized. The same thing goes for blockIDs. States are read from the world by matching the full stateID against a table of prefilled known blocks, so the variant doesn't need to be deserialized - only the state does, and the state metadata readers already do bit fuckery by themselves and don't need this mask - notice how little actual changes were required to get rid of this?
This is better for performance because these then don't need to be reevaluated every time they are called.
When encountering an unqualified function or constant reference, PHP will first try to locate a symbol in the current namespace by that name, and then fall back to the global namespace.
This short-circuits the check, which has substantial performance effects in some cases - in particular, ord(), chr() and strlen() show ~1500x faster calls when they are fully qualified.
However, this doesn't mean that PM is getting a massive amount faster. In real world terms, this translates to about 10-15% performance improvement.
But before anyone gets excited, you should know that the CodeOptimizer in the PreProcessor repo has been applying fully-qualified symbol optimizations to Jenkins builds for years, which is one of the reasons why Jenkins builds have better performance than home-built or source installations.
We're choosing to do this for the sake of future SafePHP integration and also to be able to get rid of the buggy CodeOptimizer, so that phar and source are more consistent.
This filters out over 200 invalid states which were previously considered just fine, including zero-width cakes, buttons with broken facing values, furnace/chest with crazy values, and more.
The cause of this was the flow decay of falling water changing, but the flow decay is ignored for falling water. This caused the block to be repeatedly set to itself, triggering local block updates, causing the disease to spread in large falling water bodies and cause immense amounts of lag.
this parameter was previously used to send blocks with a different set of flags, immediately, to players. However, the flags have been demonstrated useless and the direct sending is pointless now since packets are buffered now per session, so we might as well take advantage of the batched block update sending.
This is a major change to the way block metadata is handled within the PM core. This separates variant metadata (which really ought to be part of the ID) from state metadata, and in a couple of cases flattens separate states of blocks together.
The result of this is that invalid variants can be much more easily detected, and additionally state handling is much cleaner since meta is only needed at the serialize layer instead of throughout the code.
This allows the removal of lots of ugly code, and also exposes lots of similarities with how this update type was handled. This can be further improved in the future to more generically handle cases.
I realized in the process of changing this, that it might actually be simpler to treat to treat scheduled updates and neighbour updates as one and the same. They use the same mechanism for being saved on chunks (TileTicks),
and doing that would make updating only require one queue instead of two.
RedstoneOre: use onActivate() to trigger glowing
this is not technically correct behaviour, but this preserves the current behaviour.
getDrops() should now be overridden only for special cases. There are some non-trivial overrides left that are going to need some extra work to clean up.
* Added Liquid->getLiquidLevelDecreasePerBlock()
* Fixed lava turning into cobblestone when flowing over water
* Cache liquid flow vectors for faster entity movement
* Removed a condition that made lava impossible to get rid of
In the PC code, the equivalent code makes the delay between scheduled ticks 4 times longer. Here, it just breaks the code. I don't know what the 4x stuff is about, but this code does not produce the expected behaviour and lava works fine regardless.
* Fixed strange behaviour with liquids trying to flow into other liquids
Liquids should consider other liquids as a path of least resistance. However, they should not actually flow into them. This fixes a variety of CPU leak issues with falling water in large water bodies such as oceans.
This also fixes the plus-shape effect that liquid is supposed to produce when a source is placed above ground.
* Removed a bad optimization making liquids flowing down slopes behave undesirably
* Optimize performance of slope searching by limiting recursion depth based on previous path lengths
If we already found a step down on a previous run after 2 blocks, it doesn't make sense to continue allowing checking 4 blocks because the results will just be ignored. This allows limiting the number of recursion steps, which significantly improves the performance when flowing down slopes.
However, this will still be just as bad for performance on flat terrain as it was to start with.
* Make some Liquid methods only accept Blocks as parameters
these are only ever passed blocks anyway, doesn't make sense to allow vectors.
* Moved some things to local variables
these are each only used in one function, so it doesn't make sense for them to be class members.
* Fixed water flow down slopes going everywhere, but degraded performance again
* Lava should only search 2 blocks for a slope
* Stop wasting CPU calculating optimal flow directions for liquids with too-high decay
It calculates the flow directions and THEN doesn't use them when it
realizes the flow decay is too high. This is completely pointless.
* Use a less hacky method to handle lava flowing into water
* Doubled flow performance on flat terrain
Since calculateFlowCost() usually ends up visiting the same blocks about 6 times when on flat terrain, it makes sense to cache some stuff for when blocks get revisited so expensive dumb checks don't need to keep on being done. On my machine this produces a 50-60% performance improvement when flowing on flat terrain.
* Fixed missing return values in Liquid->onUpdate()
these return values aren't used anywhere, but we should be consistent
* Don't allow flowing back in the same direction we just came from
This reduces the recursions by about 30%, providing about the same percentage performance improvement.
* Remove Liquid's temporalVector (it's not used anymore)
primitive types for the win!
* Move liquid collide to its own method
* add sound for lava/water mix
Most of these methods are called from onUpdate(). It's unreasonable to
assume that the level might be null during a tick (unless a plugin
messes with a block update event or something, but that's undefined
behaviour anyway). Using getLevel() simply wastes processing time by
constantly checking if the level is closed.
This should only execute if the current liquid block is actually still existent. When decay is negative, it means the water block doesn't exist anymore.
