Added Xoroshiro

src/main/java/kaptainwutax/seedutils/rand/IRand.java

@@ -0,0 +1,11 @@
+package kaptainwutax.seedutils.rand;
+
+public interface IRand {
+	int nextInt();
+	int nextInt(int bound);
+	boolean nextBoolean();
+	float nextFloat();
+	long nextLong();
+	double nextDouble();
+	double nextGaussian();
+}

src/main/java/kaptainwutax/seedutils/rand/JRand.java

@@ -7,7 +7,8 @@
 import java.util.Random;
 import java.util.RandomAccess;
 
-public class JRand extends Rand {
+@SuppressWarnings("unused")
+public class JRand extends Rand implements IRand {
 
 	private static final double DOUBLE_UNIT = 0x1.0p-53;
 

src/main/java/kaptainwutax/seedutils/rand/Xoroshiro128PlusPlus.java

@@ -0,0 +1,130 @@
+package kaptainwutax.seedutils.rand;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+@SuppressWarnings("unused")
+public class Xoroshiro128PlusPlus implements IRand {
+	public Seed128 seed;
+	public static final long GOLDEN_RATIO_64 = -7046029254386353131L;
+	public static final long SILVER_RATIO_64 = 7640891576956012809L;
+	private static final AtomicLong SEED_UNIQUIFIER = new AtomicLong(8682522807148012L);
+	private double nextNextGaussian;
+	private boolean haveNextNextGaussian;
+
+	// http://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html
+	// Also named mix64variant13 which is David Stafford’s Mix13 variant of the
+	// MurmurHash3 finalizer
+	public static long mixStafford13(long l) {
+		l = (l ^ l >>> 30) * -4658895280553007687L;
+		l = (l ^ l >>> 27) * -7723592293110705685L;
+		return l ^ l >>> 31;
+	}
+
+	public static Seed128 upgradeSeedTo128bit(long seed) {
+		long silverSeed = seed ^ SILVER_RATIO_64;
+		long goldenSeed = silverSeed + GOLDEN_RATIO_64;
+		return new Seed128(mixStafford13(silverSeed), mixStafford13(goldenSeed));
+	}
+
+	public static long seedUniquifier() {
+		return SEED_UNIQUIFIER.updateAndGet(l -> l * 1181783497276652981L) ^ System.nanoTime();
+	}
+
+	public Xoroshiro128PlusPlus(long loSeed, long hiSeed) {
+		this.seed = new Seed128(loSeed, hiSeed);
+		if ((loSeed | hiSeed) == 0L) {
+			//  the fractional parts of square roots of squarefree numbers *2^64.
+			this.seed = new Seed128(-7046029254386353131L, 7640891576956012809L);
+		}
+	}
+
+	public Xoroshiro128PlusPlus(long seed) {
+		this.seed = upgradeSeedTo128bit(seed);
+	}
+
+	public int nextInt() {
+		return (int) this.nextLong();
+	}
+
+
+	public int nextInt(int n) {
+		if (n <= 0) {
+			throw new IllegalArgumentException("Bound must be positive");
+		}
+		return Math.abs((int) (this.nextLong() % (long) n));
+	}
+
+
+	public boolean nextBoolean() {
+		return (this.nextLong() & 1L) != 0L;
+	}
+
+
+	public float nextFloat() {
+		return (float) this.nextBits(24) * 5.9604645E-8f;
+	}
+
+
+	public double nextDouble() {
+		return (double) this.nextBits(53) * 1.1102230246251565E-16;
+	}
+
+
+	public void consumeCount(int n) {
+		for (int i = 0; i < n; ++i) {
+			this.nextLong();
+		}
+	}
+
+	public double nextGaussian() {
+		if (this.haveNextNextGaussian) {
+			this.haveNextNextGaussian = false;
+			return this.nextNextGaussian;
+		} else {
+			double s;
+			double v1;
+			double v2;
+			do {
+				v1 = 2.0 * this.nextDouble() - 1.0; // between -1 and 1
+				v2 = 2.0 * this.nextDouble() - 1.0; // between -1 and 1
+				s = v1 * v1 + v2 * v2;
+			} while (s >= 1.0 || s == 0.0);
+			double multiplier = StrictMath.sqrt(-2.0 * StrictMath.log(s) / s);
+			this.nextNextGaussian = v2 * multiplier;
+			this.haveNextNextGaussian = true;
+			return v1 * multiplier;
+		}
+	}
+
+	private long nextBits(int n) {
+		return this.nextLong() >>> 64 - n;
+	}
+
+	public long nextLong() {
+		long lowSeed = this.seed.loSeed;
+		long hiSeed = this.seed.hiSeed;
+		long res = Long.rotateLeft(lowSeed + hiSeed, 17) + lowSeed;
+
+		this.seed.loSeed = Long.rotateLeft(lowSeed, 49) ^ (hiSeed ^= lowSeed) ^ (hiSeed << 21);
+		this.seed.hiSeed = Long.rotateLeft(hiSeed, 28);
+		return res;
+	}
+
+	public static class Seed128 {
+		public long hiSeed;
+		public long loSeed;
+
+		public Seed128(long lo, long hi) {
+			loSeed = lo;
+			hiSeed = hi;
+		}
+
+		@Override
+		public String toString() {
+			return "Seed128{" +
+					"hiSeed=" + hiSeed +
+					", loSeed=" + loSeed +
+					'}';
+		}
+	}
+}