Added RegisterClientReloadListenersEvent which lets you register reload listeners with appropriate timing.

Added new entity rendering events.
- EntityRenderersEvent.RegisterLayerDefinitions: Used to register layer definitions for entity models.
- EntityRenderersEvent.RegisterRenderers: Used to register entity renderers.
- EntityRenderersEvent.AddLayers: Called during resource reload after all renderers have been constructed and it's safe to add layers.
Removed RenderingRegistry, which is now not necessary.
Removed a few unused things.
Fixes #7920

src/main/java/net/minecraftforge/client/ForgeHooksClient.java

@@ -20,8 +20,12 @@
 package net.minecraftforge.client;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.mojang.blaze3d.vertex.PoseStack;
 import com.mojang.blaze3d.vertex.VertexConsumer;
+import net.minecraft.client.model.geom.ModelLayerLocation;
+import net.minecraft.client.model.geom.builders.LayerDefinition;
+import net.minecraft.client.renderer.entity.EntityRendererProvider;
 import net.minecraft.world.effect.MobEffectInstance;
 import net.minecraft.world.level.block.state.BlockState;
 import com.mojang.blaze3d.platform.Window;
@@ -112,11 +116,13 @@ import java.io.File;
 import java.lang.reflect.Field;
 import java.nio.Buffer;
 import java.nio.ByteBuffer;
+import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Random;
 import java.util.Set;
+import java.util.function.Supplier;
 import java.util.stream.Stream;
 
 import static net.minecraftforge.client.event.RenderGameOverlayEvent.ElementType.BOSSINFO;
@@ -840,4 +846,17 @@ public class ForgeHooksClient
         ForgeTextureMetadata metadata = ForgeTextureMetadata.forResource(resource);
         return metadata.getLoader() == null ? null : metadata.getLoader().load(textureAtlas, resourceManager, textureInfo, resource, atlasWidth, atlasHeight, spriteX, spriteY, mipmapLevel, image);
     }
+
+
+    private static final Map<ModelLayerLocation, Supplier<LayerDefinition>> layerDefinitions = new HashMap<>();
+
+    public static void registerLayerDefinition(ModelLayerLocation layerLocation, Supplier<LayerDefinition> supplier)
+    {
+        layerDefinitions.put(layerLocation, supplier);
+    }
+
+    public static void loadLayerDefinitions(ImmutableMap.Builder<ModelLayerLocation, LayerDefinition> builder) {
+        layerDefinitions.forEach((k, v) -> builder.put(k, v.get()));
+    }
+
 }

src/main/java/net/minecraftforge/client/event/EntityRenderersEvent.java

@@ -0,0 +1,132 @@
+/*
+ * 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.event;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.model.EntityModel;
+import net.minecraft.client.model.geom.EntityModelSet;
+import net.minecraft.client.model.geom.ModelLayerLocation;
+import net.minecraft.client.model.geom.builders.LayerDefinition;
+import net.minecraft.client.renderer.entity.EntityRenderer;
+import net.minecraft.client.renderer.entity.EntityRendererProvider;
+import net.minecraft.client.renderer.entity.EntityRenderers;
+import net.minecraft.client.renderer.entity.LivingEntityRenderer;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.entity.EntityType;
+import net.minecraft.world.entity.LivingEntity;
+import net.minecraft.world.entity.player.Player;
+import net.minecraftforge.client.ForgeHooksClient;
+import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.fml.event.IModBusEvent;
+
+import javax.annotation.Nullable;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Supplier;
+
+public class EntityRenderersEvent extends Event implements IModBusEvent
+{
+    public static class RegisterLayerDefinitions extends EntityRenderersEvent
+    {
+        /**
+         * Registers a layer definition supplier with the given {@link ModelLayerLocation}.
+         * These will be inserted into the main layer definition map for entity model layers at the appropriate time.
+         *
+         * @param layerLocation The model layer location, which should be used in conjunction with {@link EntityRendererProvider.Context#bakeLayer(ModelLayerLocation)}
+         * @param supplier A supplier to create a {@link LayerDefinition}, generally a static method reference in the entity model class
+         */
+        public void registerLayerDefinition(ModelLayerLocation layerLocation, Supplier<LayerDefinition> supplier)
+        {
+            ForgeHooksClient.registerLayerDefinition(layerLocation, supplier);
+        }
+    }
+
+    /**
+     * Provides a safe place to register entity renderers and layer renderers.
+     */
+    public static class RegisterRenderers extends EntityRenderersEvent
+    {
+        /**
+         * Registers an entity renderer.
+         *
+         * @param entityType The EntityType to register a renderer for
+         * @param entityRendererProvider The renderer provider, can be a lambda like MyRenderer::new
+         */
+        public <T extends Entity> void registerEntityRenderer(EntityType<? extends T> entityType, EntityRendererProvider<T> entityRendererProvider)
+        {
+            EntityRenderers.register(entityType, entityRendererProvider);
+        }
+    }
+
+    /**
+     * Provides a safe place to register entity renderer layers.
+     */
+    public static class AddLayers extends EntityRenderersEvent
+    {
+        private final Map<EntityType<?>, EntityRenderer<?>> renderers;
+        private final Map<String, EntityRenderer<? extends Player>> skinMap;
+        private final EntityModelSet entityModels = Minecraft.getInstance().getEntityModels();
+
+        public AddLayers(Map<EntityType<?>, EntityRenderer<?>> renderers, Map<String, EntityRenderer<? extends Player>> playerRenderers)
+        {
+            this.renderers = renderers;
+            this.skinMap = playerRenderers;
+        }
+
+        /**
+         * Returns the list of skins.
+         */
+        public Set<String> getSkins()
+        {
+            return skinMap.keySet();
+        }
+
+        /**
+         * Returns a player skin renderer. Vanilla skins are "default" and "slim".
+         * @param skinName The name of the skin renderer to return
+         * @param <R> The type of the skin renderer, usually PlayerRenderer
+         * @return The skin renderer, or null if not found
+         */
+        @Nullable
+        @SuppressWarnings("unchecked")
+        public <R extends LivingEntityRenderer<? extends Player, ? extends EntityModel<? extends Player>>> R getSkin(String skinName)
+        {
+            return (R) skinMap.get(skinName);
+        }
+
+        /**
+         * Returns an entity renderer for the given entity type.
+         * @param entityType The entity to return a renderer for
+         * @param <T> The type of entity the renderer is for
+         * @param <R> The renderer type
+         * @return The renderer
+         */
+        @Nullable
+        @SuppressWarnings("unchecked")
+        public <T extends LivingEntity, R extends LivingEntityRenderer<T, ? extends EntityModel<T>>> R getRenderer(EntityType<? extends T> entityType) {
+            return (R) renderers.get(entityType);
+        }
+
+        public EntityModelSet getEntityModels()
+        {
+            return entityModels;
+        }
+    }
+}

src/main/java/net/minecraftforge/client/event/RegisterClientReloadListenersEvent.java

@@ -17,13 +17,24 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.fmlclient.registry;
+package net.minecraftforge.client.event;
 
-import net.minecraft.client.renderer.entity.EntityRenderer;
-import net.minecraft.client.renderer.entity.EntityRenderDispatcher;
-import net.minecraft.world.entity.Entity;
+import net.minecraft.server.packs.resources.PreparableReloadListener;
+import net.minecraft.server.packs.resources.ReloadableResourceManager;
+import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.fml.event.IModBusEvent;
 
-public interface IRenderFactory<T extends Entity>
+public class RegisterClientReloadListenersEvent extends Event implements IModBusEvent
 {
-    EntityRenderer<? super T> createRenderFor(EntityRenderDispatcher manager);
+    private final ReloadableResourceManager resourceManager;
+
+    public RegisterClientReloadListenersEvent(ReloadableResourceManager resourceManager)
+    {
+        this.resourceManager = resourceManager;
+    }
+
+    public void registerReloadListener(PreparableReloadListener reloadListener)
+    {
+        resourceManager.registerReloadListener(reloadListener);
+    }
 }

src/main/java/net/minecraftforge/fmlclient/ClientModLoader.java

@@ -39,7 +39,6 @@ import net.minecraft.server.packs.repository.Pack;
 import net.minecraft.server.packs.repository.PackRepository;
 import net.minecraft.world.level.DataPackConfig;
 import net.minecraftforge.fml.*;
-import net.minecraftforge.fmlclient.registry.RenderingRegistry;
 import net.minecraftforge.fmllegacy.BrandingControl;
 import net.minecraftforge.fmllegacy.CrashReportExtender;
 import net.minecraftforge.fmllegacy.LogicalSidedProvider;
@@ -137,15 +136,6 @@ public class ClientModLoader
         createRunnableWithCatch(() -> ModLoader.get().loadMods(syncExecutor, parallelExecutor, new SpacedRunnable(earlyLoaderGUI::renderTick))).run();
     }
 
-    private static void postSidedRunnable() {
-        LOGGER.debug(LOADING, "Running post client event work");
-        RenderingRegistry.loadEntityRenderers();
-    }
-
-    private static void preSidedRunnable() {
-        LOGGER.debug(LOADING, "Running pre client event work");
-    }
-
     private static void finishModLoading(ModWorkManager.DrivenExecutor syncExecutor, Executor parallelExecutor)
     {
         createRunnableWithCatch(() -> ModLoader.get().finishMods(syncExecutor, parallelExecutor, new SpacedRunnable(earlyLoaderGUI::renderTick))).run();

src/main/java/net/minecraftforge/fmlclient/registry/RenderingRegistry.java

@@ -1,120 +0,0 @@
-/*
- * 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.fmlclient.registry;
-
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.function.Supplier;
-
-import com.google.common.collect.ImmutableMap;
-import net.minecraft.client.model.geom.ModelLayerLocation;
-import net.minecraft.client.model.geom.builders.LayerDefinition;
-import net.minecraft.client.renderer.entity.EntityRendererProvider;
-import net.minecraft.client.renderer.entity.EntityRenderers;
-import net.minecraft.resources.ResourceLocation;
-import net.minecraft.world.entity.Entity;
-import net.minecraft.world.entity.EntityType;
-
-public class RenderingRegistry
-{
-    private static final RenderingRegistry INSTANCE = new RenderingRegistry();
-
-    private final Map<EntityType<? extends Entity>, EntityRendererProvider<? extends Entity>> entityRenderers = new ConcurrentHashMap<>();
-    private final Map<ModelLayerLocation, Supplier<LayerDefinition>> layerDefinitions = new ConcurrentHashMap<>();
-
-    /**
-     * Register an entity rendering handler. This will, after mod initialization, be inserted into the main
-     * render map for entities.
-     * Call this during {@link net.minecraftforge.fml.event.lifecycle.FMLClientSetupEvent}.
-     * This method is safe to call during parallel mod loading.
-     */
-    public static <T extends Entity> void registerEntityRenderingHandler(EntityType<T> entityClass, EntityRendererProvider<? super T> renderProvider)
-    {
-        INSTANCE.entityRenderers.put(entityClass, renderProvider);
-    }
-
-    /**
-     * Registers a layer definition supplier with the given {@link ModelLayerLocation}. This will, after mod
-     * initialization, be inserted into the main layer definition map for entity model layers.
-     * <p>
-     * Call this during {@link net.minecraftforge.fml.event.lifecycle.FMLClientSetupEvent}.
-     * This method is safe to call during parallel mod loading.
-     * @param layerLocation The model layer location, which should be used in conjunction with {@link EntityRendererProvider.Context#bakeLayer(ModelLayerLocation)}
-     * @param supplier A supplier to create a {@link LayerDefinition}, generally a static method reference in the entity model class
-     */
-    public static void registerLayerDefinition(ModelLayerLocation layerLocation, Supplier<LayerDefinition> supplier)
-    {
-        INSTANCE.layerDefinitions.put(layerLocation, supplier);
-    }
-
-    public static void loadEntityRenderers()
-    {
-        INSTANCE.entityRenderers.forEach(RenderingRegistry::register);
-        EntityRenderers.validateRegistrations();
-    }
-
-    public static void loadLayerDefinitions(ImmutableMap.Builder<ModelLayerLocation, LayerDefinition> builder) {
-        INSTANCE.layerDefinitions.forEach((k, v) -> builder.put(k, v.get()));
-    }
-
-    @SuppressWarnings("unchecked")
-    private static <T extends Entity> void register(EntityType<T> entityType, EntityRendererProvider<?> renderProvider)
-    {
-        EntityRenderers.register(entityType, ((EntityRendererProvider<T>)renderProvider));
-    }
-
-    private static ModelLayerLocation registerModelLayer(ResourceLocation model, String layer)
-    {
-        return new ModelLayerLocation(model, layer);
-    }
-
-    /**
-     * Registers a model layer location for the main layer definition of an entity.
-     *
-     * @param model The model {@link ResourceLocation}
-     * @return A main model layer location
-     */
-    public static ModelLayerLocation registerMainModelLayer(ResourceLocation model)
-    {
-        return registerModelLayer(model, "main");
-    }
-
-    /**
-     * Registers a model layer location for the inner armor layer definition of an entity.
-     *
-     * @param model The model {@link ResourceLocation}
-     * @return An inner armor model layer location
-     */
-    public static ModelLayerLocation registerInnerArmorModelLayer(ResourceLocation model)
-    {
-        return registerModelLayer(model, "inner_armor");
-    }
-
-    /**
-     * Registers a model layer location for the outer armor layer definition of an entity.
-     *
-     * @param model The model {@link ResourceLocation}
-     * @return An outer armor model layer location
-     */
-    public static ModelLayerLocation registerOuterArmorModelLayer(ResourceLocation model)
-    {
-        return registerModelLayer(model, "outer_armor");
-    }
-}