Package net.minecraft.world.gen

Class ChunkRandom

java.lang.Object
java.util.Random
net.minecraft.world.gen.ChunkRandom
All Implemented Interfaces:
Serializable, WorldGenRandom
public class ChunkRandom
extends Random
implements WorldGenRandom
See Also:
Serialized Form
Mappings:
Namespace Name
official cmz
intermediary net/minecraft/class_2919
named net/minecraft/world/gen/ChunkRandom

  • Field Details

    • sampleCount

      private int sampleCount
      Mappings:
      Namespace Name Mixin selector
      official a Lcmz;a:I
      intermediary field_28768 Lnet/minecraft/class_2919;field_28768:I
      named sampleCount Lnet/minecraft/world/gen/ChunkRandom;sampleCount:I

  • Constructor Details

    • ChunkRandom

      public ChunkRandom()

    • ChunkRandom

      public ChunkRandom​(long seed)
      Mappings:
      Namespace Name Mixin selector
      official <init> Lcmz;<init>(J)V
      intermediary <init> Lnet/minecraft/class_2919;<init>(J)V
      named <init> Lnet/minecraft/world/gen/ChunkRandom;<init>(J)V

  • Method Details

    • next

      public int next​(int count)
      Overrides:
      next in class Random
      Mappings:
      Namespace Name Mixin selector
      official next Lcmz;next(I)I
      intermediary next Lnet/minecraft/class_2919;next(I)I
      named next Lnet/minecraft/world/gen/ChunkRandom;next(I)I

    • setTerrainSeed

      public long setTerrainSeed​(int chunkX, int chunkZ)
      Seeds the randomizer to generate the surface terrain blocks (such as grass, sand, etc.) and the bedrock patterns.

      Note that the terrain seed does not depend on the world seed and only gets affected by chunk coordinates.

      Mappings:
      Namespace Name Mixin selector
      official a Lcmz;a(II)J
      intermediary method_12659 Lnet/minecraft/class_2919;method_12659(II)J
      named setTerrainSeed Lnet/minecraft/world/gen/ChunkRandom;setTerrainSeed(II)J

    • 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 Lcmz;a(JII)J
      intermediary method_12661 Lnet/minecraft/class_2919;method_12661(JII)J
      named setPopulationSeed Lnet/minecraft/world/gen/ChunkRandom;setPopulationSeed(JII)J

    • setDecoratorSeed

      public long 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().
      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 Lcmz;b(JII)J
      intermediary method_12664 Lnet/minecraft/class_2919;method_12664(JII)J
      named setDecoratorSeed Lnet/minecraft/world/gen/ChunkRandom;setDecoratorSeed(JII)J

    • setCarverSeed

      public long 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 Lcmz;c(JII)J
      intermediary method_12663 Lnet/minecraft/class_2919;method_12663(JII)J
      named setCarverSeed Lnet/minecraft/world/gen/ChunkRandom;setCarverSeed(JII)J

    • setRegionSeed

      public long 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 Lcmz;a(JIII)J
      intermediary method_12665 Lnet/minecraft/class_2919;method_12665(JIII)J
      named setRegionSeed Lnet/minecraft/world/gen/ChunkRandom;setRegionSeed(JIII)J

    • getSlimeRandom

      public static Random getSlimeRandom​(int chunkX, int chunkZ, long worldSeed, long scrambler)
      Mappings:
      Namespace Name Mixin selector
      official a Lcmz;a(IIJJ)Ljava/util/Random;
      intermediary method_12662 Lnet/minecraft/class_2919;method_12662(IIJJ)Ljava/util/Random;
      named getSlimeRandom Lnet/minecraft/world/gen/ChunkRandom;getSlimeRandom(IIJJ)Ljava/util/Random;