Package net.minecraft.world.gen.random

Class ChunkRandom

java.lang.Object

java.util.Random

net.minecraft.world.gen.random.ChunkRandom

All Implemented Interfaces:

Serializable, RandomGenerator, AbstractRandom

public class ChunkRandom
extends Random
implements AbstractRandom

See Also:

• Serialized Form

Mappings:

Namespace	Name
official	cua
intermediary	net/minecraft/class_2919
named	net/minecraft/world/gen/random/ChunkRandom

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	ChunkRandom.RandomProvider

Nested classes/interfaces inherited from interface java.util.random.RandomGenerator

RandomGenerator.ArbitrarilyJumpableGenerator, RandomGenerator.JumpableGenerator, RandomGenerator.LeapableGenerator, RandomGenerator.SplittableGenerator, RandomGenerator.StreamableGenerator

Field Summary

Fields

Modifier and Type	Field	Description
private final AbstractRandom	baseRandom
private int	sampleCount

Constructor Summary

Constructors

Constructor	Description
ChunkRandom(AbstractRandom baseRandom)

Method Summary

Modifier and Type	Method	Description
RandomDeriver	createRandomDeriver()
AbstractRandom	derive()
int	getSampleCount()
static Random	getSlimeRandom(int chunkX, int chunkZ, long worldSeed, long scrambler)
int	next(int count)
void	setCarverSeed(long worldSeed, int chunkX, int chunkZ)	Seeds the randomizer to generate larger features such as caves, ravines, mineshafts and strongholds.
void	setDecoratorSeed(long populationSeed, int index, int step)	Seeds the randomizer to generate a given feature.
long	setPopulationSeed(long worldSeed, int blockX, int blockZ)	Seeds the randomizer to create population features such as decorators and animals.
void	setRegionSeed(long worldSeed, int regionX, int regionZ, int salt)	Seeds the randomizer to determine the start position of structure features such as temples, monuments and buried treasures within a region.
void	setSeed(long seed)

Methods inherited from class java.util.Random

doubles, doubles, doubles, doubles, ints, ints, ints, ints, longs, longs, longs, longs, nextBoolean, nextBytes, nextDouble, nextFloat, nextGaussian, nextInt, nextInt, nextLong

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface net.minecraft.world.gen.random.AbstractRandom

nextBetween, nextBoolean, nextDouble, nextFloat, nextGaussian, nextInt, nextInt, nextLong, skip

Methods inherited from interface java.util.random.RandomGenerator

isDeprecated, nextDouble, nextDouble, nextExponential, nextFloat, nextFloat, nextGaussian, nextInt, nextLong, nextLong

Field Details

baseRandom

private final AbstractRandom baseRandom

Mappings:

Namespace	Name	Mixin selector
official	a	Lcua;a:Lctq;
intermediary	field_35141	Lnet/minecraft/class_2919;field_35141:Lnet/minecraft/class_5819;
named	baseRandom	Lnet/minecraft/world/gen/random/ChunkRandom;baseRandom:Lnet/minecraft/world/gen/random/AbstractRandom;

sampleCount

private int sampleCount

Mappings:

Namespace	Name	Mixin selector
official	b	Lcua;b:I
intermediary	field_28768	Lnet/minecraft/class_2919;field_28768:I
named	sampleCount	Lnet/minecraft/world/gen/random/ChunkRandom;sampleCount:I

Constructor Details

ChunkRandom

public ChunkRandom(AbstractRandom baseRandom)

Mappings:

Namespace	Name	Mixin selector
official	<init>	Lcua;<init>(Lctq;)V
intermediary	<init>	Lnet/minecraft/class_2919;<init>(Lnet/minecraft/class_5819;)V
named	<init>	Lnet/minecraft/world/gen/random/ChunkRandom;<init>(Lnet/minecraft/world/gen/random/AbstractRandom;)V

Method Details

getSampleCount

public int getSampleCount()

Mappings:

Namespace	Name	Mixin selector
official	c	Lcua;c()I
intermediary	method_35335	Lnet/minecraft/class_2919;method_35335()I
named	getSampleCount	Lnet/minecraft/world/gen/random/ChunkRandom;getSampleCount()I

derive

public AbstractRandom derive()

Specified by:

derive in interface AbstractRandom

Mappings:

Namespace	Name	Mixin selector
official	a	Lctq;a()Lctq;
intermediary	method_38420	Lnet/minecraft/class_5819;method_38420()Lnet/minecraft/class_5819;
named	derive	Lnet/minecraft/world/gen/random/AbstractRandom;derive()Lnet/minecraft/world/gen/random/AbstractRandom;

createRandomDeriver

public RandomDeriver createRandomDeriver()

Specified by:

createRandomDeriver in interface AbstractRandom

Mappings:

Namespace	Name	Mixin selector
official	b	Lctq;b()Lctp;
intermediary	method_38421	Lnet/minecraft/class_5819;method_38421()Lnet/minecraft/class_6574;
named	createRandomDeriver	Lnet/minecraft/world/gen/random/AbstractRandom;createRandomDeriver()Lnet/minecraft/world/gen/random/RandomDeriver;

next

public int next(int count)

Overrides:

next in class Random

Mappings:

Namespace	Name	Mixin selector
official	next	Lcua;next(I)I
intermediary	next	Lnet/minecraft/class_2919;next(I)I
named	next	Lnet/minecraft/world/gen/random/ChunkRandom;next(I)I

setSeed

public void setSeed(long seed)

Specified by:

setSeed in interface AbstractRandom

Overrides:

setSeed in class Random

Mappings:

Namespace	Name	Mixin selector
official	setSeed	Lctq;setSeed(J)V
intermediary	setSeed	Lnet/minecraft/class_5819;setSeed(J)V
named	setSeed	Lnet/minecraft/world/gen/random/AbstractRandom;setSeed(J)V

setPopulationSeed

public long setPopulationSeed(long worldSeed,
 int blockX,
 int blockZ)

Seeds the randomizer to create population features such as decorators and animals.

This method takes in the world seed and the negative-most block coordinates of the chunk. The coordinate pair provided is equivalent to (chunkX * 16, chunkZ * 16). The three values are mixed together through some layers of hashing to produce the population seed.

This function has been proved to be reversible through some exploitation of the underlying nextLong() weaknesses. It is also important to remember that since setSeed() truncates the 16 upper bits of world seed, only the 48 lowest bits affect the population seed output.

Mappings:

Namespace	Name	Mixin selector
official	a	Lcua;a(JII)J
intermediary	method_12661	Lnet/minecraft/class_2919;method_12661(JII)J
named	setPopulationSeed	Lnet/minecraft/world/gen/random/ChunkRandom;setPopulationSeed(JII)J

setDecoratorSeed

public void setDecoratorSeed(long populationSeed,
 int index,
 int step)

Seeds the randomizer to generate a given feature. The salt, in the form of index + 10000 * step assures that each feature is seeded differently, making the decoration feel more random. Even though it does a good job at doing so, many entropy issues arise from the salt being so small and result in weird alignments between features that have an index close apart.

Parameters:

populationSeed - the population seed computed in setPopulationSeed(long, int, int)

index - the index of the feature in the feature list

step - the generation step's ordinal for this feature

Mappings:

Namespace	Name	Mixin selector
official	b	Lcua;b(JII)V
intermediary	method_12664	Lnet/minecraft/class_2919;method_12664(JII)V
named	setDecoratorSeed	Lnet/minecraft/world/gen/random/ChunkRandom;setDecoratorSeed(JII)V

setCarverSeed

public void setCarverSeed(long worldSeed,
 int chunkX,
 int chunkZ)

Seeds the randomizer to generate larger features such as caves, ravines, mineshafts and strongholds. It is also used to initiate structure start behavior such as rotation.

Similar to the population seed, only the 48 lowest bits of the world seed affect the output since it the upper 16 bits are truncated in the setSeed() call.

Mappings:

Namespace	Name	Mixin selector
official	c	Lcua;c(JII)V
intermediary	method_12663	Lnet/minecraft/class_2919;method_12663(JII)V
named	setCarverSeed	Lnet/minecraft/world/gen/random/ChunkRandom;setCarverSeed(JII)V

setRegionSeed

public void setRegionSeed(long worldSeed,
 int regionX,
 int regionZ,
 int salt)

Seeds the randomizer to determine the start position of structure features such as temples, monuments and buried treasures within a region.

The region coordinates pair corresponds to the coordinates of the region the seeded chunk lies in. For example, a swamp hut region is 32 by 32 chunks meaning that all chunks that lie within that region get seeded the same way.

Similarly, the upper 16 bits of world seed also do not affect the region seed because they get truncated in the setSeed() call.

Mappings:

Namespace	Name	Mixin selector
official	a	Lcua;a(JIII)V
intermediary	method_12665	Lnet/minecraft/class_2919;method_12665(JIII)V
named	setRegionSeed	Lnet/minecraft/world/gen/random/ChunkRandom;setRegionSeed(JIII)V

getSlimeRandom

public static Random getSlimeRandom(int chunkX,
 int chunkZ,
 long worldSeed,
 long scrambler)

Mappings:

Namespace	Name	Mixin selector
official	a	Lcua;a(IIJJ)Ljava/util/Random;
intermediary	method_12662	Lnet/minecraft/class_2919;method_12662(IIJJ)Ljava/util/Random;
named	getSlimeRandom	Lnet/minecraft/world/gen/random/ChunkRandom;getSlimeRandom(IIJJ)Ljava/util/Random;