Reintroduce BeforeBake and AfterBake model modifiers (#4320)

fabric-model-loading-api-v1/src/client/java/net/fabricmc/fabric/api/client/model/loading/v1/ModelLoadingPlugin.java

@@ -82,12 +82,38 @@ interface Context {
 
 		/**
 		 * Event access to monitor unbaked model loads and replace the loaded model.
+		 *
+		 * <p>Replacements done by listeners of this callback <b>do</b> affect child models (that is, models whose
+		 * parent hierarchy contains the replaced model), unlike {@link #modifyModelBeforeBake}.
 		 */
 		Event<ModelModifier.OnLoad> modifyModelOnLoad();
 
+		/**
+		 * Event access to replace the unbaked model used for baking without replacing the cached model.
+		 *
+		 * <p>Replacements done by listeners of this callback <b>do not</b> affect child models (that is, models whose
+		 * parent hierarchy contains the replaced model), unlike {@link #modifyModelOnLoad}.
+		 */
+		Event<ModelModifier.BeforeBake> modifyModelBeforeBake();
+
+		/**
+		 * Event access to replace the baked model.
+		 */
+		Event<ModelModifier.AfterBake> modifyModelAfterBake();
+
 		/**
 		 * Event access to monitor unbaked block model loads and replace the loaded model.
 		 */
 		Event<ModelModifier.OnLoadBlock> modifyBlockModelOnLoad();
+
+		/**
+		 * Event access to replace the unbaked block model used for baking.
+		 */
+		Event<ModelModifier.BeforeBakeBlock> modifyBlockModelBeforeBake();
+
+		/**
+		 * Event access to replace the baked block model.
+		 */
+		Event<ModelModifier.AfterBakeBlock> modifyBlockModelAfterBake();
 	}
 }

fabric-model-loading-api-v1/src/client/java/net/fabricmc/fabric/api/client/model/loading/v1/ModelModifier.java

@@ -20,7 +20,10 @@
 import org.jetbrains.annotations.Nullable;
 
 import net.minecraft.block.BlockState;
+import net.minecraft.client.render.model.BakedModel;
+import net.minecraft.client.render.model.Baker;
 import net.minecraft.client.render.model.GroupableModel;
+import net.minecraft.client.render.model.ModelBakeSettings;
 import net.minecraft.client.render.model.ResolvableModel;
 import net.minecraft.client.render.model.UnbakedModel;
 import net.minecraft.client.util.ModelIdentifier;
@@ -44,7 +47,7 @@
  * and separate phases are provided for mods that wrap their own models and mods that need to wrap models of other mods
  * or wrap models arbitrarily.
  *
- * <p>These callbacks are invoked for <b>every single model that is loaded</b>, so implementations should be
+ * <p>These callbacks are invoked for <b>every single model that is loaded or baked</b>, so implementations should be
  * as efficient as possible.
  */
 public final class ModelModifier {
@@ -75,7 +78,11 @@ public interface OnLoad {
 		 * <p>If the given model is {@code null}, its corresponding identifier was requested during
 		 * {@linkplain ResolvableModel#resolve resolution} but the model was not loaded normally; i.e. through a JSON
 		 * file, possibly because that file did not exist. If a non-{@code null} model is returned in this case,
-		 * resolution will continue without warnings or errors.
+		 * resolution will continue without warnings or errors. This callback can return a {@code null} model, which
+		 * has the same meaning as described earlier, so it is unlikely that an implementor should need to return
+		 * {@code null} unless directly returning the given model.
+		 *
+		 * <p>For further information, see the docs of {@link ModelLoadingPlugin.Context#modifyModelOnLoad()}.
 		 *
 		 * @param model the current unbaked model instance
 		 * @param context context with additional information about the model/loader
@@ -97,6 +104,86 @@ interface Context {
 		}
 	}
 
+	@FunctionalInterface
+	public interface BeforeBake {
+		/**
+		 * This handler is invoked to allow modification of the unbaked model instance right before it is baked.
+		 *
+		 * <p>For further information, see the docs of {@link ModelLoadingPlugin.Context#modifyModelBeforeBake()}.
+		 *
+		 * @param model the current unbaked model instance
+		 * @param context context with additional information about the model/loader
+		 * @return the model that should be used in this scenario. If no changes are needed, just return {@code model} as-is.
+		 * @see ModelLoadingPlugin.Context#modifyModelBeforeBake
+		 */
+		UnbakedModel modifyModelBeforeBake(UnbakedModel model, Context context);
+
+		/**
+		 * The context for a before bake model modification event.
+		 */
+		@ApiStatus.NonExtendable
+		interface Context {
+			/**
+			 * The identifier of the model being baked.
+			 */
+			Identifier id();
+
+			/**
+			 * The settings this model is being baked with.
+			 */
+			ModelBakeSettings settings();
+
+			/**
+			 * The baker being used to bake this model. It can be used to {@linkplain Baker#bake bake models} and
+			 * {@linkplain Baker#getSpriteGetter get sprites}. Note that baking a model which was not previously
+			 * {@linkplain ResolvableModel.Resolver#resolve resolved} will log a warning and return the missing model.
+			 */
+			Baker baker();
+		}
+	}
+
+	@FunctionalInterface
+	public interface AfterBake {
+		/**
+		 * This handler is invoked to allow modification of the baked model instance right after it is baked and before
+		 * it is cached.
+		 *
+		 * @param model the current baked model instance
+		 * @param context context with additional information about the model/loader
+		 * @return the model that should be used in this scenario. If no changes are needed, just return {@code model} as-is.
+		 * @see ModelLoadingPlugin.Context#modifyModelAfterBake
+		 */
+		BakedModel modifyModelAfterBake(BakedModel model, Context context);
+
+		/**
+		 * The context for an after bake model modification event.
+		 */
+		@ApiStatus.NonExtendable
+		interface Context {
+			/**
+			 * The identifier of the model being baked.
+			 */
+			Identifier id();
+
+			/**
+			 * The unbaked model that is being baked.
+			 */
+			UnbakedModel sourceModel();
+
+			/**
+			 * The settings this model is being baked with.
+			 */
+			ModelBakeSettings settings();
+
+			/**
+			 * The baker being used to bake this model. It can be used to {@linkplain Baker#bake bake models} and
+			 * {@linkplain Baker#getSpriteGetter get sprites}. Note that baking a model which was not previously
+			 * {@linkplain ResolvableModel.Resolver#resolve resolved} will log a warning and return the missing model.
+			 */
+			Baker baker();
+		}
+	}
+
 	@FunctionalInterface
 	public interface OnLoadBlock {
 		/**
@@ -126,5 +213,72 @@ interface Context {
 		}
 	}
 
+	@FunctionalInterface
+	public interface BeforeBakeBlock {
+		/**
+		 * This handler is invoked to allow modification of the unbaked block model instance right before it is baked.
+		 *
+		 * @param model the current unbaked model instance
+		 * @param context context with additional information about the model/loader
+		 * @return the model that should be used in this scenario. If no changes are needed, just return {@code model} as-is.
+		 * @see ModelLoadingPlugin.Context#modifyBlockModelBeforeBake
+		 */
+		GroupableModel modifyModelBeforeBake(GroupableModel model, Context context);
+
+		/**
+		 * The context for a before bake block model modification event.
+		 */
+		@ApiStatus.NonExtendable
+		interface Context {
+			/**
+			 * The identifier of the model being baked.
+			 */
+			ModelIdentifier id();
+
+			/**
+			 * The baker being used to bake this model. It can be used to {@linkplain Baker#bake bake models} and
+			 * {@linkplain Baker#getSpriteGetter get sprites}. Note that baking a model which was not previously
+			 * {@linkplain ResolvableModel.Resolver#resolve resolved} will log a warning and return the missing model.
+			 */
+			Baker baker();
+		}
+	}
+
+	@FunctionalInterface
+	public interface AfterBakeBlock {
+		/**
+		 * This handler is invoked to allow modification of the baked block model instance right after it is baked.
+		 *
+		 * @param model the current baked model instance
+		 * @param context context with additional information about the model/loader
+		 * @return the model that should be used in this scenario. If no changes are needed, just return {@code model} as-is.
+		 * @see ModelLoadingPlugin.Context#modifyBlockModelAfterBake
+		 */
+		BakedModel modifyModelAfterBake(BakedModel model, Context context);
+
+		/**
+		 * The context for an after bake block model modification event.
+		 */
+		@ApiStatus.NonExtendable
+		interface Context {
+			/**
+			 * The identifier of the model being baked.
+			 */
+			ModelIdentifier id();
+
+			/**
+			 * The unbaked model that is being baked.
+			 */
+			GroupableModel sourceModel();
+
+			/**
+			 * The baker being used to bake this model. It can be used to {@linkplain Baker#bake bake models} and
+			 * {@linkplain Baker#getSpriteGetter get sprites}. Note that baking a model which was not previously
+			 * {@linkplain ResolvableModel.Resolver#resolve resolved} will log a warning and return the missing model.
+			 */
+			Baker baker();
+		}
+	}
+
 	private ModelModifier() { }
 }

fabric-model-loading-api-v1/src/client/java/net/fabricmc/fabric/impl/client/model/loading/ModelBakerHooks.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.fabric.impl.client.model.loading;
+
+import org.jetbrains.annotations.Nullable;
+
+public interface ModelBakerHooks {
+	@Nullable
+	ModelLoadingEventDispatcher fabric_getDispatcher();
+}