From 925c7526ee36fb5d280ab16ecf7d2d6cd37f7b2c Mon Sep 17 00:00:00 2001
From: embeddedt <42941056+embeddedt@users.noreply.github.com>
Date: Sun, 1 Mar 2026 15:46:52 -0500
Subject: [PATCH] Reduce memory usage of ImposterProtoChunks

---
 .../ChunkAccessMixin.java                     | 22 +++++++++++++++++++
 .../ImposterProtoChunkMixin.java              | 22 +++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 src/main/java/org/embeddedt/modernfix/common/mixin/perf/compact_imposterprotochunks/ChunkAccessMixin.java
 create mode 100644 src/main/java/org/embeddedt/modernfix/common/mixin/perf/compact_imposterprotochunks/ImposterProtoChunkMixin.java

diff --git a/src/main/java/org/embeddedt/modernfix/common/mixin/perf/compact_imposterprotochunks/ChunkAccessMixin.java b/src/main/java/org/embeddedt/modernfix/common/mixin/perf/compact_imposterprotochunks/ChunkAccessMixin.java
new file mode 100644
index 00000000..0343f25b
--- /dev/null
+++ b/src/main/java/org/embeddedt/modernfix/common/mixin/perf/compact_imposterprotochunks/ChunkAccessMixin.java
@@ -0,0 +1,22 @@
+package org.embeddedt.modernfix.common.mixin.perf.compact_imposterprotochunks;
+
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+import net.minecraft.world.level.lighting.ChunkSkyLightSources;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+
+@Mixin(ChunkAccess.class)
+public class ChunkAccessMixin {
+    @Shadow
+    @Final
+    @Mutable
+    protected LevelChunkSection[] sections;
+
+    @Shadow
+    protected ChunkSkyLightSources skyLightSources;
+}
diff --git a/src/main/java/org/embeddedt/modernfix/common/mixin/perf/compact_imposterprotochunks/ImposterProtoChunkMixin.java b/src/main/java/org/embeddedt/modernfix/common/mixin/perf/compact_imposterprotochunks/ImposterProtoChunkMixin.java
new file mode 100644
index 00000000..36829c70
--- /dev/null
+++ b/src/main/java/org/embeddedt/modernfix/common/mixin/perf/compact_imposterprotochunks/ImposterProtoChunkMixin.java
@@ -0,0 +1,22 @@
+package org.embeddedt.modernfix.common.mixin.perf.compact_imposterprotochunks;
+
+import net.minecraft.world.level.chunk.ImposterProtoChunk;
+import net.minecraft.world.level.chunk.LevelChunk;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(ImposterProtoChunk.class)
+public abstract class ImposterProtoChunkMixin extends ChunkAccessMixin {
+    /**
+     * @author embeddedt
+     * @reason ImposterProtoChunks allocate their own LevelChunkSection objects etc. which wastes quite
+     * a bit of memory
+     */
+    @Inject(method = "<init>", at = @At("RETURN"))
+    private void replaceDuplicateObjects(LevelChunk wrapped, boolean allowWrites, CallbackInfo ci) {
+        this.sections = wrapped.getSections();
+        this.skyLightSources = wrapped.getSkyLightSources();
+    }
+}