104 lines
2.6 KiB
Java
104 lines
2.6 KiB
Java
package net.lax1dude.eaglercraft.v1_8;
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/**
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* Copyright (c) 2022 LAX1DUDE. All Rights Reserved.
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*
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* WITH THE EXCEPTION OF PATCH FILES, MINIFIED JAVASCRIPT, AND ALL FILES
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* NORMALLY FOUND IN AN UNMODIFIED MINECRAFT RESOURCE PACK, YOU ARE NOT ALLOWED
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* TO SHARE, DISTRIBUTE, OR REPURPOSE ANY FILE USED BY OR PRODUCED BY THE
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* SOFTWARE IN THIS REPOSITORY WITHOUT PRIOR PERMISSION FROM THE PROJECT AUTHOR.
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*
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* NOT FOR COMMERCIAL OR MALICIOUS USE
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*
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* (please read the 'LICENSE' file this repo's root directory for more info)
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*
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*/
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public class EaglercraftRandom {
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private static final long multiplier = 0x5DEECE66DL;
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private static final long addend = 0xBL;
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private static final long mask = (1L << 48) - 1;
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private static final double DOUBLE_UNIT = 0x1.0p-53;
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private long seed = 69;
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private static int yee = 0;
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public EaglercraftRandom() {
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this(System.currentTimeMillis() + (++yee));
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}
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public EaglercraftRandom(long seed) {
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setSeed(seed);
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}
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public void setSeed(long yeed) {
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seed = yeed;
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}
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protected int next(int bits) {
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seed = (seed * multiplier + addend) & mask;
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return (int) (seed >>> (48 - bits));
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}
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public void nextBytes(byte[] bytes) {
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for (int i = 0, len = bytes.length; i < len;)
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for (int rnd = nextInt(), n = Math.min(len - i, Integer.SIZE / Byte.SIZE); n-- > 0; rnd >>= Byte.SIZE)
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bytes[i++] = (byte) rnd;
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}
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public int nextInt() {
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return next(32);
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}
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public int nextInt(int bound) {
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int r = next(31);
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int m = bound - 1;
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if ((bound & m) == 0) // i.e., bound is a power of 2
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r = (int) ((bound * (long) r) >> 31);
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else {
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for (int u = r; u - (r = u % bound) + m < 0; u = next(31))
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;
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}
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return r;
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}
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public long nextLong() {
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return ((long) (next(32)) << 32) + next(32);
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}
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public boolean nextBoolean() {
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return next(1) != 0;
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}
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public float nextFloat() {
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return next(24) / ((float) (1 << 24));
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}
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public double nextDouble() {
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return (((long) (next(26)) << 27) + next(27)) * DOUBLE_UNIT;
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}
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private double nextNextGaussian;
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private boolean haveNextNextGaussian = false;
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public double nextGaussian() {
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// See Knuth, ACP, Section 3.4.1 Algorithm C.
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if (haveNextNextGaussian) {
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haveNextNextGaussian = false;
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return nextNextGaussian;
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} else {
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double v1, v2, s;
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do {
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v1 = 2 * nextDouble() - 1; // between -1 and 1
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v2 = 2 * nextDouble() - 1; // between -1 and 1
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s = v1 * v1 + v2 * v2;
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} while (s >= 1 || s == 0);
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double multiplier = StrictMath.sqrt(-2 * StrictMath.log(s) / s);
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nextNextGaussian = v2 * multiplier;
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haveNextNextGaussian = true;
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return v1 * multiplier;
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}
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}
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}
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