Emulate the vanilla block/item -> model maps for Fabric mods

common/src/main/java/org/embeddedt/modernfix/common/mixin/perf/dynamic_resources/BlockModelShaperMixin.java

@@ -6,10 +6,13 @@ import net.minecraft.client.resources.model.ModelManager;
 import net.minecraft.world.level.block.state.BlockState;
 import org.embeddedt.modernfix.annotation.ClientOnlyMixin;
 import org.embeddedt.modernfix.dynamicresources.ModelLocationCache;
-import org.spongepowered.asm.mixin.Final;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Overwrite;
-import org.spongepowered.asm.mixin.Shadow;
+import org.embeddedt.modernfix.util.DynamicMap;
+import org.spongepowered.asm.mixin.*;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.Map;
 
 
 @Mixin(BlockModelShaper.class)
@@ -17,6 +20,15 @@ import org.spongepowered.asm.mixin.Shadow;
 public class BlockModelShaperMixin {
     @Shadow @Final private ModelManager modelManager;
 
+    @Shadow @Final @Mutable
+    private Map<BlockState, BakedModel> modelByStateCache;
+
+    @Inject(method = "<init>", at = @At("RETURN"))
+    private void replaceModelMap(CallbackInfo ci) {
+        // replace the backing map for mods which will access it
+        this.modelByStateCache = new DynamicMap<>(state -> modelManager.getModel(ModelLocationCache.get(state)));
+    }
+
     /**
      * @author embeddedt
      * @reason no need to rebuild model cache, and location cache is done elsewhere

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

@@ -1,11 +1,13 @@
 package org.embeddedt.modernfix.common.mixin.perf.dynamic_resources;
 
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import net.minecraft.client.renderer.ItemModelShaper;
 import net.minecraft.client.resources.model.BakedModel;
 import net.minecraft.client.resources.model.ModelManager;
 import net.minecraft.client.resources.model.ModelResourceLocation;
 import net.minecraft.world.item.Item;
 import org.embeddedt.modernfix.dynamicresources.ModelLocationCache;
+import org.embeddedt.modernfix.util.DynamicInt2ObjectMap;
 import org.spongepowered.asm.mixin.*;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
@@ -19,6 +21,8 @@ public abstract class ItemModelShaperMixin {
 
     @Shadow public abstract ModelManager getModelManager();
 
+    @Shadow @Final @Mutable private Int2ObjectMap<BakedModel> shapesCache;
+
     private Map<Item, ModelResourceLocation> overrideLocationsVanilla;
 
     public ItemModelShaperMixin() {
@@ -30,6 +34,7 @@ public abstract class ItemModelShaperMixin {
     @Inject(method = "<init>", at = @At("RETURN"))
     private void replaceLocationMap(CallbackInfo ci) {
         overrideLocationsVanilla = new HashMap<>();
+        this.shapesCache = new DynamicInt2ObjectMap<>(index -> getModelManager().getModel(ModelLocationCache.get(Item.byId(index))));
     }
 
     @Unique

common/src/main/java/org/embeddedt/modernfix/util/DynamicInt2ObjectMap.java

@@ -0,0 +1,61 @@
+package org.embeddedt.modernfix.util;
+
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.IntSet;
+import it.unimi.dsi.fastutil.objects.ObjectCollection;
+import it.unimi.dsi.fastutil.objects.ObjectSet;
+
+import java.util.Map;
+import java.util.function.Function;
+
+public class DynamicInt2ObjectMap<V> extends DynamicMap<Integer, V> implements Int2ObjectMap<V> {
+    public DynamicInt2ObjectMap(Function<Integer, V> function) {
+        super(function);
+    }
+
+    @Override
+    public IntSet keySet() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public ObjectCollection<V> values() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public ObjectSet<Map.Entry<Integer, V>> entrySet() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void defaultReturnValue(V rv) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public V defaultReturnValue() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public ObjectSet<Int2ObjectMap.Entry<V>> int2ObjectEntrySet() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public V getOrDefault(int key, V defaultValue) {
+        V value = get(key);
+        return value == null ? defaultValue :  value;
+    }
+
+    @Override
+    public V get(int key) {
+        return function.apply(key);
+    }
+
+    @Override
+    public boolean containsKey(int key) {
+        return true;
+    }
+}

common/src/main/java/org/embeddedt/modernfix/util/DynamicMap.java

@@ -0,0 +1,81 @@
+package org.embeddedt.modernfix.util;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Function;
+
+public class DynamicMap<K, V> implements Map<K, V> {
+    protected final Function<K, V> function;
+
+    public DynamicMap(Function<K, V> function) {
+        this.function = function;
+    }
+
+    @Override
+    public int size() {
+        return 0;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return false;
+    }
+
+    @Override
+    public boolean containsKey(Object o) {
+        return true;
+    }
+
+    @Override
+    public boolean containsValue(Object o) {
+        return true;
+    }
+
+    @Override
+    public V get(Object o) {
+        return function.apply((K)o);
+    }
+
+    @Nullable
+    @Override
+    public V put(K k, V v) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public V remove(Object o) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void putAll(@NotNull Map<? extends K, ? extends V> map) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void clear() {
+        throw new UnsupportedOperationException();
+    }
+
+    @NotNull
+    @Override
+    public Set<K> keySet() {
+        throw new UnsupportedOperationException();
+    }
+
+    @NotNull
+    @Override
+    public Collection<V> values() {
+        throw new UnsupportedOperationException();
+    }
+
+    @NotNull
+    @Override
+    public Set<Entry<K, V>> entrySet() {
+        throw new UnsupportedOperationException();
+    }
+}