From 0a68a6923a5f28a97fbc59cbbac1bb8ec87a370f Mon Sep 17 00:00:00 2001
From: embeddedt <42941056+embeddedt@users.noreply.github.com>
Date: Sun, 28 Dec 2025 19:02:46 -0500
Subject: [PATCH] Reimplement deduplicate_wall_shapes

---
 TODO.txt                                      |  1 -
 .../WallBlockMixin.java                       | 54 +++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/org/embeddedt/modernfix/common/mixin/perf/deduplicate_wall_shapes/WallBlockMixin.java

diff --git a/TODO.txt b/TODO.txt
index 93057ed1..4807259e 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -4,4 +4,3 @@
 - Check if BlockStateData patch is still needed in compact_mojang_registries
 - Check if faster_texture_stitching is still worthwhile with 21.x changes to the stitcher
 - Sculk deadlock fix looks unnecessary since Mojang is careful about when they send the event
-- Rewrite deduplicate_wall_shapes
diff --git a/src/main/java/org/embeddedt/modernfix/common/mixin/perf/deduplicate_wall_shapes/WallBlockMixin.java b/src/main/java/org/embeddedt/modernfix/common/mixin/perf/deduplicate_wall_shapes/WallBlockMixin.java
new file mode 100644
index 00000000..14ecba4c
--- /dev/null
+++ b/src/main/java/org/embeddedt/modernfix/common/mixin/perf/deduplicate_wall_shapes/WallBlockMixin.java
@@ -0,0 +1,54 @@
+package org.embeddedt.modernfix.common.mixin.perf.deduplicate_wall_shapes;
+
+import com.llamalad7.mixinextras.injector.wrapoperation.Operation;
+import com.llamalad7.mixinextras.injector.wrapoperation.WrapOperation;
+import com.mojang.datafixers.util.Pair;
+import net.minecraft.core.Direction;
+import net.minecraft.world.level.block.WallBlock;
+import net.minecraft.world.phys.shapes.VoxelShape;
+import org.joml.Vector3d;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * @author embeddedt
+ * @reason Avoid excessive memory usage in modpacks that add many variations of wall blocks. The strategy here requires
+ * multiple memoization maps, but is also the simplest way to do it without having to literally replicate the vanilla
+ * logic (as that uses blockstates rather than property maps).
+ */
+@Mixin(WallBlock.class)
+public class WallBlockMixin {
+    @Unique
+    private static final ConcurrentHashMap<Vector3d, VoxelShape> COLUMN_CACHE = new ConcurrentHashMap<>();
+    @Unique
+    private static final ConcurrentHashMap<List<Double>, VoxelShape> BOX_Z_CACHE = new ConcurrentHashMap<>();
+    @Unique
+    private static final ConcurrentHashMap<VoxelShape, Map<Direction, VoxelShape>> ROTATE_HORZ_CACHE = new ConcurrentHashMap<>();
+    @Unique
+    private static final ConcurrentHashMap<Pair<VoxelShape, VoxelShape>, VoxelShape> OR_CACHE = new ConcurrentHashMap<>();
+
+    @WrapOperation(method = "makeShapes", at = @At(value = "INVOKE", target = "Lnet/minecraft/world/level/block/Block;column(DDD)Lnet/minecraft/world/phys/shapes/VoxelShape;"))
+    private VoxelShape memoizeColumn(double sizeXZ, double minY, double postHeight, Operation<VoxelShape> original) {
+        return COLUMN_CACHE.computeIfAbsent(new Vector3d(sizeXZ, minY, postHeight), l -> original.call(sizeXZ, minY, postHeight));
+    }
+
+    @WrapOperation(method = "makeShapes", at = @At(value = "INVOKE", target = "Lnet/minecraft/world/level/block/Block;boxZ(DDDDD)Lnet/minecraft/world/phys/shapes/VoxelShape;"))
+    private VoxelShape memoizeBoxZ(double sizeX, double minY, double maxY, double minZ, double maxZ, Operation<VoxelShape> original) {
+        return BOX_Z_CACHE.computeIfAbsent(List.of(sizeX, minY, maxY, minZ, maxZ), l -> original.call(sizeX, minY, maxY, minZ, maxZ));
+    }
+
+    @WrapOperation(method = "makeShapes", at = @At(value = "INVOKE", target = "Lnet/minecraft/world/phys/shapes/Shapes;rotateHorizontal(Lnet/minecraft/world/phys/shapes/VoxelShape;)Ljava/util/Map;"))
+    private Map<Direction, VoxelShape> memoizeRotateHorizontal(VoxelShape north, Operation<Map<Direction, VoxelShape>> original) {
+        return ROTATE_HORZ_CACHE.computeIfAbsent(north, l -> original.call(north));
+    }
+
+    @WrapOperation(method = "lambda$makeShapes$0", at = @At(value = "INVOKE", target = "Lnet/minecraft/world/phys/shapes/Shapes;or(Lnet/minecraft/world/phys/shapes/VoxelShape;Lnet/minecraft/world/phys/shapes/VoxelShape;)Lnet/minecraft/world/phys/shapes/VoxelShape;"))
+    private static VoxelShape memoizeOr(VoxelShape one, VoxelShape two, Operation<VoxelShape> original) {
+        return OR_CACHE.computeIfAbsent(Pair.of(one, two), l -> original.call(one, two));
+    }
+}