Initial implementation

src/main/java/ru/dbotthepony/mc/prng/GJRAND64RandomSource.java

@@ -0,0 +1,142 @@
+package ru.dbotthepony.mc.prng;
+
+import it.unimi.dsi.fastutil.HashCommon;
+import net.minecraft.util.Mth;
+import net.minecraft.util.RandomSource;
+import net.minecraft.world.level.levelgen.MarsagliaPolarGaussian;
+import net.minecraft.world.level.levelgen.PositionalRandomFactory;
+import net.minecraft.world.level.levelgen.RandomSupport;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.random.RandomGenerator;
+
+public final class GJRAND64RandomSource implements RandomGenerator, RandomSource {
+	private long s0;
+	private long s1;
+	private long s2;
+	private long s3;
+
+	private final MarsagliaPolarGaussian gaussian = new MarsagliaPolarGaussian(this);
+
+	public GJRAND64RandomSource() {
+		reinitialize(RandomSupport.generateUniqueSeed(), RandomSupport.generateUniqueSeed());
+	}
+
+	public GJRAND64RandomSource(long seed) {
+		reinitialize(seed);
+	}
+
+	public GJRAND64RandomSource(long seed0, long seed1) {
+		reinitialize(seed0, seed1);
+	}
+
+	private void reinitialize(long seed) {
+		reinitialize(seed, 0L);
+	}
+
+	private void reinitialize(long seed0, long seed1) {
+		s0 = seed0;
+		s1 = seed1;
+		s2 = 2000001L;
+		s3 = 0L;
+	}
+
+	@Override
+	public @NotNull RandomSource fork() {
+		return new GJRAND64RandomSource(nextLong(), nextLong());
+	}
+
+	@Override
+	public @NotNull PositionalRandomFactory forkPositional() {
+		return new Positional(nextLong(), nextLong());
+	}
+
+	@Override
+	public void setSeed(long l) {
+		reinitialize(l);
+		gaussian.reset();
+	}
+
+	@Override
+	public int nextInt() {
+		return RandomGenerator.super.nextInt();
+	}
+
+	@Override
+	public int nextInt(int bound) {
+		return RandomGenerator.super.nextInt(bound);
+	}
+
+	@Override
+	public int nextInt(int origin, int bound) {
+		return RandomGenerator.super.nextInt(origin, bound);
+	}
+
+	@Override
+	public float nextFloat() {
+		return RandomGenerator.super.nextFloat();
+	}
+
+	@Override
+	public boolean nextBoolean() {
+		return RandomGenerator.super.nextBoolean();
+	}
+
+	@Override
+	public double nextDouble() {
+		return RandomGenerator.super.nextDouble();
+	}
+
+	@Override
+	public double nextGaussian() {
+		return gaussian.nextGaussian();
+	}
+
+	@Override
+	public long nextLong() {
+		s1 += s2;
+		s0 = Long.rotateLeft(s0, 32);
+		s2 ^= s1;
+		s3 += 0x55aa96a5L;
+		s0 += s1;
+		s2 = Long.rotateLeft(s2, 23);
+		s1 ^= s0;
+		s0 += s2;
+		s1 = Long.rotateLeft(s1, 19);
+		s2 += s0;
+		s1 += s3;
+		return s0;
+	}
+
+	public static class Positional implements PositionalRandomFactory {
+		private final long seed0;
+		private final long seed1;
+
+		public Positional(long seed0, long seed1) {
+			this.seed0 = seed0;
+			this.seed1 = seed1;
+		}
+
+		@Override
+		public @NotNull RandomSource fromHashOf(@NotNull String s) {
+			long seed = HashCommon.murmurHash3((long) s.hashCode() & 0xFFFFFFFFL);
+			return new GJRAND64RandomSource(seed0 ^ Long.rotateLeft(seed, 32), seed1 ^ seed);
+		}
+
+		@Override
+		public @NotNull RandomSource fromSeed(long l) {
+			return new GJRAND64RandomSource(l);
+		}
+
+		@Override
+		public @NotNull RandomSource at(int x, int y, int z) {
+			long seed = Mth.getSeed(x, y, z);
+			return new GJRAND64RandomSource(seed0 ^ Long.rotateLeft(seed, 32), seed1 ^ seed);
+		}
+
+		@Override
+		public void parityConfigString(@NotNull StringBuilder stringBuilder) {
+			throw new UnsupportedOperationException();
+		}
+	}
+}

src/main/java/ru/dbotthepony/mc/prng/mixin/RandomSourceMixin.java

@@ -0,0 +1,19 @@
+package ru.dbotthepony.mc.prng.mixin;
+
+import net.minecraft.util.RandomSource;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Overwrite;
+import ru.dbotthepony.mc.prng.GJRAND64RandomSource;
+
+@Mixin(RandomSource.class)
+public interface RandomSourceMixin {
+	@Overwrite
+	static RandomSource create() {
+		return new GJRAND64RandomSource();
+	}
+
+	@Overwrite
+	static RandomSource create(long seed) {
+		return new GJRAND64RandomSource(seed);
+	}
+}

src/main/resources/better_random.mixins.json

@@ -0,0 +1,11 @@
+
+{
+  "required": true,
+  "package": "ru.dbotthepony.mc.prng.mixin",
+  "compatibilityLevel": "JAVA_21",
+  "minVersion": "0.8",
+  "mixins": [
+    "RandomSourceMixin"
+  ],
+  "client": []
+}

src/main/templates/META-INF/neoforge.mods.toml

@@ -47,8 +47,8 @@ authors="${mod_authors}" #optional
 description='''${mod_description}'''
 
 # The [[mixins]] block allows you to declare your mixin config to FML so that it gets loaded.
-#[[mixins]]
-#config="${mod_id}.mixins.json"
+[[mixins]]
+config="${mod_id}.mixins.json"
 
 # The [[accessTransformers]] block allows you to declare where your AT file is.
 # If this block is omitted, a fallback attempt will be made to load an AT from META-INF/accesstransformer.cfg