From fcec612718174f6de545605cd2dcda0cd81f7a3e Mon Sep 17 00:00:00 2001
From: DBotThePony <dbotthepony@yandex.ru>
Date: Mon, 3 Mar 2025 22:19:57 +0700
Subject: [PATCH] Lock CMWC state size to 256 WORDs, improving performance of
 nextInt()

---
 .../mc/otm/core/util/CMWCRandom.kt            | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/CMWCRandom.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/CMWCRandom.kt
index aec7fc452..ae291f2d1 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/CMWCRandom.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/CMWCRandom.kt
@@ -7,8 +7,8 @@ import net.minecraft.world.level.levelgen.PositionalRandomFactory
 import java.lang.StringBuilder
 import java.util.random.RandomGenerator
 
-class CMWCRandom(seed: Long = System.nanoTime(), private val stateSize: Int = CMWC_DEFAULT_STATE_SIZE) : RandomGenerator, RandomSource {
-	private val state = IntArray(stateSize)
+class CMWCRandom(seed: Long = System.nanoTime()) : RandomGenerator, RandomSource {
+	private val state = IntArray(CMWC_STATE_SIZE)
 	private var carry = 0
 	private var stateIndex = 0
 	private val gaussian = MarsagliaPolarGaussian(this)
@@ -37,7 +37,7 @@ class CMWCRandom(seed: Long = System.nanoTime(), private val stateSize: Int = CM
 	}
 
 	override fun nextInt(): Int {
-		stateIndex = (stateIndex + 1) % state.size
+		stateIndex = (stateIndex + 1).and(CMWC_STATE_SIZE - 1)
 		val t = 18782L * state[stateIndex] + carry
 
 		carry = t.ushr(32).toInt()
@@ -83,24 +83,24 @@ class CMWCRandom(seed: Long = System.nanoTime(), private val stateSize: Int = CM
 	}
 
 	override fun fork(): RandomSource {
-		return CMWCRandom(nextLong(), stateSize)
+		return CMWCRandom(nextLong())
 	}
 
 	override fun forkPositional(): PositionalRandomFactory {
-		return Positional(nextLong(), stateSize)
+		return Positional(nextLong())
 	}
 
-	class Positional(val seed: Long, val stateSize: Int = CMWC_DEFAULT_STATE_SIZE) : PositionalRandomFactory {
+	class Positional(val seed: Long) : PositionalRandomFactory {
 		override fun at(x: Int, y: Int, z: Int): RandomSource {
-			return CMWCRandom(Mth.getSeed(x, y, z).xor(seed), stateSize)
+			return CMWCRandom(Mth.getSeed(x, y, z).xor(seed))
 		}
 
 		override fun fromHashOf(name: String): RandomSource {
-			return CMWCRandom(name.hashCode().toLong().xor(seed), stateSize)
+			return CMWCRandom(name.hashCode().toLong().xor(seed))
 		}
 
 		override fun fromSeed(seed: Long): RandomSource {
-			return CMWCRandom(seed, stateSize)
+			return CMWCRandom(seed)
 		}
 
 		override fun parityConfigString(builder: StringBuilder) {
@@ -109,7 +109,7 @@ class CMWCRandom(seed: Long = System.nanoTime(), private val stateSize: Int = CM
 	}
 
 	companion object {
-		const val CMWC_DEFAULT_STATE_SIZE = 256 // 4096
+		const val CMWC_STATE_SIZE = 256 // 4096
 		const val CMWC_CARRY_MAX = 809430660
 	}
 }