Dynamically generate item model location cache

src/main/java/org/embeddedt/modernfix/dynamicresources/ModelLocationCache.java

@@ -10,8 +10,10 @@ import net.minecraft.Util;
 import net.minecraft.client.renderer.block.BlockModelShaper;
 import net.minecraft.client.resources.model.ModelResourceLocation;
 import net.minecraft.core.Registry;
+import net.minecraft.world.item.Item;
 import net.minecraft.world.level.block.Block;
 import net.minecraft.world.level.block.state.BlockState;
+import net.minecraftforge.registries.IRegistryDelegate;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -20,7 +22,7 @@ import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 
 public class ModelLocationCache {
-    private static final LoadingCache<BlockState, ModelResourceLocation> locationCache = CacheBuilder.newBuilder()
+    private static final LoadingCache<BlockState, ModelResourceLocation> blockLocationCache = CacheBuilder.newBuilder()
             .maximumSize(10000)
             .build(new CacheLoader<BlockState, ModelResourceLocation>() {
                 @Override
@@ -29,9 +31,26 @@ public class ModelLocationCache {
                 }
             });
 
+    private static final LoadingCache<Item, ModelResourceLocation> itemLocationCache = CacheBuilder.newBuilder()
+            .maximumSize(10000)
+            .build(new CacheLoader<Item, ModelResourceLocation>() {
+                @Override
+                public ModelResourceLocation load(Item key) throws Exception {
+                    return new ModelResourceLocation(Registry.ITEM.getKey(key), "inventory");
+                }
+            });
+
     public static ModelResourceLocation get(BlockState state) {
         try {
-            return locationCache.get(state);
+            return blockLocationCache.get(state);
+        } catch(ExecutionException e) {
+            throw new RuntimeException(e.getCause());
+        }
+    }
+
+    public static ModelResourceLocation get(Item item) {
+        try {
+            return itemLocationCache.get(item);
         } catch(ExecutionException e) {
             throw new RuntimeException(e.getCause());
         }

src/main/java/org/embeddedt/modernfix/mixin/perf/dynamic_resources/ItemModelShaperMixin.java

@@ -7,6 +7,7 @@ import net.minecraft.client.resources.model.ModelResourceLocation;
 import net.minecraft.world.item.Item;
 import net.minecraftforge.client.ItemModelMesherForge;
 import net.minecraftforge.registries.IRegistryDelegate;
+import org.embeddedt.modernfix.dynamicresources.ModelLocationCache;
 import org.spongepowered.asm.mixin.Final;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Overwrite;
@@ -22,6 +23,8 @@ public abstract class ItemModelShaperMixin extends ItemModelShaper {
         super(arg);
     }
 
+    private static final ModelResourceLocation SENTINEL = new ModelResourceLocation("modernfix", "sentinel");
+
     /**
      * @reason Get the stored location for that item and meta, and get the model
      * from that location from the model manager.
@@ -29,7 +32,11 @@ public abstract class ItemModelShaperMixin extends ItemModelShaper {
     @Overwrite
     @Override
     public BakedModel getItemModel(Item item) {
-        ModelResourceLocation map = locations.get(item.delegate);
+        ModelResourceLocation map = locations.getOrDefault(item.delegate, SENTINEL);
+        if(map == SENTINEL) {
+            /* generate the appropriate location from our cache */
+            map = ModelLocationCache.get(item);
+        }
         return map == null ? null : getModelManager().getModel(map);
     }
 

src/main/java/org/embeddedt/modernfix/mixin/perf/dynamic_resources/ItemRendererMixin.java

@@ -0,0 +1,20 @@
+package org.embeddedt.modernfix.mixin.perf.dynamic_resources;
+
+import net.minecraft.client.renderer.ItemModelShaper;
+import net.minecraft.client.renderer.entity.ItemRenderer;
+import net.minecraft.client.resources.model.ModelResourceLocation;
+import net.minecraft.world.item.Item;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+@Mixin(ItemRenderer.class)
+public class ItemRendererMixin {
+    /**
+     * Don't waste space putting all these locations into the cache, compute them on demand later.
+     */
+    @Redirect(method = "<init>", at = @At(value = "INVOKE", target = "Lnet/minecraft/client/renderer/ItemModelShaper;register(Lnet/minecraft/world/item/Item;Lnet/minecraft/client/resources/model/ModelResourceLocation;)V"))
+    private void skipDefaultRegistration(ItemModelShaper shaper, Item item, ModelResourceLocation mrl) {
+
+    }
+}

src/main/resources/modernfix.mixins.json

@@ -92,6 +92,7 @@
     "perf.dynamic_resources.BlockElementFaceDeserializerMixin",
     "perf.dynamic_resources.BlockModelShaperMixin",
     "perf.dynamic_resources.ItemModelShaperMixin",
+    "perf.dynamic_resources.ItemRendererMixin",
     "perf.dynamic_resources.ModelBakeryMixin",
     "perf.dynamic_resources.ae2.RegistrationMixin",
     "perf.dynamic_resources.ctm.TextureMetadataHandlerMixin",