From bc2c531e1fa970f5a4cfb14f58da2cc055357b02 Mon Sep 17 00:00:00 2001
From: DBotThePony <dbotthepony@yandex.ru>
Date: Mon, 3 Mar 2025 12:20:29 +0700
Subject: [PATCH] Attach CMWC random to Level class, as alternative random to
 be used in OTM

---
 .../dbotthepony/mc/otm/mixin/LevelMixin.java   | 18 ++++++++++++++++++
 .../dbotthepony/mc/otm/core/IMatteryWorld.kt   | 16 ++++++++++++++++
 .../overdrive_that_matters.mixins.json         |  3 ++-
 3 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/ru/dbotthepony/mc/otm/mixin/LevelMixin.java
 create mode 100644 src/main/kotlin/ru/dbotthepony/mc/otm/core/IMatteryWorld.kt

diff --git a/src/main/java/ru/dbotthepony/mc/otm/mixin/LevelMixin.java b/src/main/java/ru/dbotthepony/mc/otm/mixin/LevelMixin.java
new file mode 100644
index 000000000..cee3aabab
--- /dev/null
+++ b/src/main/java/ru/dbotthepony/mc/otm/mixin/LevelMixin.java
@@ -0,0 +1,18 @@
+package ru.dbotthepony.mc.otm.mixin;
+
+import net.minecraft.util.RandomSource;
+import net.minecraft.world.level.Level;
+import org.jetbrains.annotations.NotNull;
+import org.spongepowered.asm.mixin.Mixin;
+import ru.dbotthepony.mc.otm.core.IMatteryWorld;
+import ru.dbotthepony.mc.otm.core.util.CMWCRandom;
+
+@Mixin(Level.class)
+public abstract class LevelMixin implements IMatteryWorld {
+	public final RandomSource otm_random = new CMWCRandom();
+
+	@Override
+	public @NotNull RandomSource getOtmRandom() {
+		return otm_random;
+	}
+}
diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/core/IMatteryWorld.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/core/IMatteryWorld.kt
new file mode 100644
index 000000000..137f222e2
--- /dev/null
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/core/IMatteryWorld.kt
@@ -0,0 +1,16 @@
+package ru.dbotthepony.mc.otm.core
+
+import net.minecraft.util.RandomSource
+import net.minecraft.world.level.Level
+
+interface IMatteryWorld {
+	/**
+	 * OTM provided [RandomSource], which has better statistical parameters
+	 *
+	 * Original Minecraft use LCG, which may show bad behavior when repeatedly sampled *a lot*,
+	 * which is what [Level]'s random is used for. OTM provided PRNG should behave better in this scenario.
+	 */
+	val otmRandom: RandomSource
+}
+
+val Level.otmRandom: RandomSource get() = (this as IMatteryWorld).otmRandom
diff --git a/src/main/resources/overdrive_that_matters.mixins.json b/src/main/resources/overdrive_that_matters.mixins.json
index 934ead87e..f317fa83a 100644
--- a/src/main/resources/overdrive_that_matters.mixins.json
+++ b/src/main/resources/overdrive_that_matters.mixins.json
@@ -18,7 +18,8 @@
     "HopperBlockEntityMixin",
     "DispenserBlockEntityMixin",
     "GuiGraphicsMixin",
-    "BlockStateBaseMixin"
+    "BlockStateBaseMixin",
+    "LevelMixin"
   ],
   "client": [
     "MixinGameRenderer",