Added MultipartBakedModel.getModelData(). (#7595)

This allows custom IBakedModel implementations to use the IModelData provided by their IBakedModel.getModelData() when used in the context of a multipart model.

patches/minecraft/net/minecraft/client/renderer/model/MultipartBakedModel.java.patch

@@ -37,7 +37,7 @@
           for(int j = 0; j < bitset.length(); ++j) {
              if (bitset.get(j)) {
 -               list.addAll(this.field_188626_f.get(j).getRight().func_200117_a(p_200117_1_, p_200117_2_, new Random(k)));
-+               list.addAll(this.field_188626_f.get(j).getRight().getQuads(p_200117_1_, p_200117_2_, new Random(k), modelData));
++               list.addAll(this.field_188626_f.get(j).getRight().getQuads(p_200117_1_, p_200117_2_, new Random(k), net.minecraftforge.client.model.data.MultipartModelData.resolve(this.field_188626_f.get(j).getRight(), modelData)));
              }
           }
  
@@ -52,7 +52,7 @@
     public boolean func_177556_c() {
        return this.field_188622_b;
     }
-@@ -86,14 +93,24 @@
+@@ -86,18 +93,33 @@
        return false;
     }
  
@@ -77,3 +77,12 @@
     public ItemOverrideList func_188617_f() {
        return this.field_188625_e;
     }
+ 
++   @Override
++   public net.minecraftforge.client.model.data.IModelData getModelData(net.minecraft.world.IBlockDisplayReader world, net.minecraft.util.math.BlockPos pos, BlockState state, net.minecraftforge.client.model.data.IModelData tileData) {
++      return net.minecraftforge.client.model.data.MultipartModelData.create(field_188626_f, world, pos, state, tileData);
++   }
++
+    @OnlyIn(Dist.CLIENT)
+    public static class Builder {
+       private final List<Pair<Predicate<BlockState>, IBakedModel>> field_188649_a = Lists.newArrayList();

src/main/java/net/minecraftforge/client/model/data/MultipartModelData.java

@@ -0,0 +1,105 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2021.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.client.model.data;
+
+import net.minecraft.block.BlockState;
+import net.minecraft.client.renderer.model.IBakedModel;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.IBlockDisplayReader;
+import org.apache.commons.lang3.tuple.Pair;
+
+import javax.annotation.Nullable;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Predicate;
+
+public class MultipartModelData implements IModelData
+{
+    public static final ModelProperty<MultipartModelData> MULTIPART_DATA = new ModelProperty<>();
+
+    public static IModelData create(List<Pair<Predicate<BlockState>, IBakedModel>> selectors, IBlockDisplayReader world, BlockPos pos, BlockState state, IModelData tileData)
+    {
+        MultipartModelData multipartData = new MultipartModelData(tileData);
+        for (Pair<Predicate<BlockState>, IBakedModel> selector : selectors)
+        {
+            if (selector.getLeft().test(state))
+            {
+                IBakedModel part = selector.getRight();
+                IModelData partData = part.getModelData(world, pos, state, tileData);
+                multipartData.setPartData(part, partData);
+            }
+        }
+        return multipartData;
+    }
+
+    public static IModelData resolve(IBakedModel part, IModelData modelData)
+    {
+        MultipartModelData multipartData = modelData.getData(MultipartModelData.MULTIPART_DATA);
+        if (multipartData != null)
+            return multipartData.getPartData(part, modelData);
+        return modelData;
+    }
+
+    private final IModelData tileData;
+    private final Map<IBakedModel, IModelData> partData = new HashMap<>();
+
+    public MultipartModelData(IModelData tileData)
+    {
+        this.tileData = tileData;
+    }
+
+    public void setPartData(IBakedModel part, IModelData data)
+    {
+        partData.put(part, data);
+    }
+
+    @Nullable
+    public IModelData getPartData(IBakedModel part, final IModelData defaultData)
+    {
+        return partData.getOrDefault(part, defaultData);
+    }
+
+    @Override
+    public boolean hasProperty(ModelProperty<?> prop)
+    {
+        return prop == MULTIPART_DATA || tileData.hasProperty(prop);
+    }
+
+    @SuppressWarnings("unchecked")
+    @Nullable
+    @Override
+    public <T> T getData(ModelProperty<T> prop)
+    {
+        if (prop == MULTIPART_DATA)
+            return (T)this;
+        return tileData.getData(prop);
+    }
+
+    @SuppressWarnings("unchecked")
+    @Nullable
+    @Override
+    public <T> T setData(ModelProperty<T> prop, T data)
+    {
+        if (prop == MULTIPART_DATA)
+            return (T)this;
+        return tileData.setData(prop, data);
+    }
+}