支持封装空物品

core/src/main/java/net/momirealms/craftengine/core/entity/player/Player.java

@@ -8,6 +8,7 @@ import net.momirealms.craftengine.core.plugin.network.NetWorkUser;
 import net.momirealms.craftengine.core.sound.SoundSource;
 import net.momirealms.craftengine.core.util.Key;
 import net.momirealms.craftengine.core.world.BlockPos;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
@@ -17,7 +18,7 @@ public abstract class Player extends AbstractEntity implements NetWorkUser {
 
     public abstract boolean isSecondaryUseActive();
 
-    @Nullable
+    @NotNull
     public abstract Item<?> getItemInHand(InteractionHand hand);
 
     @Override

core/src/main/java/net/momirealms/craftengine/core/item/AbstractItem.java

@@ -23,6 +23,11 @@ public class AbstractItem<W extends ItemWrapper<I>, I> implements Item<I> {
         this.item = item;
     }
 
+    @Override
+    public boolean isEmpty() {
+        return this.factory.isEmpty(this.item);
+    }
+
     @Override
     public Item<I> itemModel(String data) {
         this.factory.itemModel(this.item, data);

core/src/main/java/net/momirealms/craftengine/core/item/Item.java

@@ -24,6 +24,8 @@ import java.util.Optional;
  */
 public interface Item<I> {
 
+    boolean isEmpty();
+
     Optional<CustomItem<I>> getCustomItem();
 
     Optional<List<ItemBehavior>> getItemBehavior();

core/src/main/java/net/momirealms/craftengine/core/item/ItemFactory.java

@@ -202,4 +202,6 @@ public abstract class ItemFactory<W extends ItemWrapper<I>, I> {
     protected abstract W transmuteCopy(W item, Key newItem, int amount);
 
     protected abstract W unsafeTransmuteCopy(W item, Object newItem, int count);
+
+    protected abstract boolean isEmpty(W item);
 }

core/src/main/java/net/momirealms/craftengine/core/item/ItemManager.java

@@ -13,6 +13,7 @@ import net.momirealms.craftengine.core.registry.Holder;
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 import net.momirealms.craftengine.core.util.Key;
 import org.incendo.cloud.suggestion.Suggestion;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.*;
@@ -36,14 +37,17 @@ public interface ItemManager<T> extends Manageable, ModelGenerator {
 
     Collection<Key> vanillaItems();
 
+    @Nullable
     T buildCustomItemStack(Key id, @Nullable Player player);
 
+    @Nullable
     T buildItemStack(Key id, @Nullable Player player);
 
     Item<T> createCustomWrappedItem(Key id, @Nullable Player player);
 
     Item<T> createWrappedItem(Key id, @Nullable Player player);
 
+    @NotNull
     Item<T> wrap(T itemStack);
 
     Item<T> fromByteArray(byte[] bytes);

core/src/main/java/net/momirealms/craftengine/core/item/context/UseOnContext.java

@@ -8,6 +8,8 @@ import net.momirealms.craftengine.core.world.BlockHitResult;
 import net.momirealms.craftengine.core.world.BlockPos;
 import net.momirealms.craftengine.core.world.Vec3d;
 import net.momirealms.craftengine.core.world.World;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class UseOnContext {
     private final Player player;
@@ -24,7 +26,7 @@ public class UseOnContext {
         this(player.world(), player, hand, stack, hit);
     }
 
-    public UseOnContext(World world, Player player, InteractionHand hand, Item<?> stack, BlockHitResult hit) {
+    public UseOnContext(@NotNull World world, Player player, InteractionHand hand, @NotNull Item<?> stack, BlockHitResult hit) {
         this.player = player;
         this.hand = hand;
         this.hitResult = hit;
@@ -52,6 +54,7 @@ public class UseOnContext {
         return this.hitResult.isInside();
     }
 
+    @NotNull
     public Item<?> getItem() {
         return this.itemStack;
     }

core/src/main/java/net/momirealms/craftengine/core/item/recipe/CraftingRecipeCategory.java

@@ -4,5 +4,11 @@ public enum CraftingRecipeCategory {
     BUILDING,
     REDSTONE,
     EQUIPMENT,
-    MISC
+    MISC;
+
+    public static final CraftingRecipeCategory[] VALUES = CraftingRecipeCategory.values();
+
+    public static CraftingRecipeCategory byId(final int id) {
+        return VALUES[id];
+    }
 }

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/legacy/LegacyIngredient.java

@@ -0,0 +1,33 @@
+package net.momirealms.craftengine.core.item.recipe.network.legacy;
+
+import net.momirealms.craftengine.core.entity.player.Player;
+import net.momirealms.craftengine.core.item.Item;
+import net.momirealms.craftengine.core.plugin.CraftEngine;
+import net.momirealms.craftengine.core.util.FriendlyByteBuf;
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.Obsolete
+public class LegacyIngredient {
+    private final Item<Object>[] items;
+
+    public LegacyIngredient(Item<Object>[] items) {
+        this.items = items;
+    }
+
+    public Item<?>[] items() {
+        return items;
+    }
+
+    @SuppressWarnings("unchecked")
+    public static LegacyIngredient read(FriendlyByteBuf buf) {
+        Item<Object>[] items = buf.readArray(byteBuf -> CraftEngine.instance().itemManager().decode(byteBuf), Item.class);
+        return new LegacyIngredient(items);
+    }
+
+    public void applyClientboundData(Player player) {
+        for (int i = 0; i < items.length; i++) {
+            Item<Object> item = items[i];
+            this.items[i] = CraftEngine.instance().itemManager().s2c(item, player);
+        }
+    }
+}

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/legacy/LegacyRecipe.java

@@ -0,0 +1,34 @@
+package net.momirealms.craftengine.core.item.recipe.network.legacy;
+
+import net.momirealms.craftengine.core.registry.BuiltInRegistries;
+import net.momirealms.craftengine.core.util.FriendlyByteBuf;
+import net.momirealms.craftengine.core.util.Key;
+import net.momirealms.craftengine.core.util.VersionHelper;
+import org.jetbrains.annotations.ApiStatus;
+
+import java.util.function.Function;
+
+@ApiStatus.Obsolete
+public interface LegacyRecipe {
+
+    void write(FriendlyByteBuf buf);
+
+    static LegacyRecipe read(FriendlyByteBuf buf) {
+        if (VersionHelper.isOrAbove1_20_5()) {
+            Key id = buf.readKey();
+            Key type = buf.readKey();
+            return BuiltInRegistries.LEGACY_RECIPE_TYPE.getValue(type).read(id, buf);
+        } else {
+            Key type = buf.readKey();
+            Key id = buf.readKey();
+            return BuiltInRegistries.LEGACY_RECIPE_TYPE.getValue(type).read(id, buf);
+        }
+    }
+
+    record Type(Function<FriendlyByteBuf, LegacyRecipe> reader) {
+
+        public LegacyRecipe read(Key id, FriendlyByteBuf buf) {
+            return this.reader.apply(buf);
+        }
+    }
+}

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/legacy/LegacyRecipeTypes.java

@@ -0,0 +1,34 @@
+package net.momirealms.craftengine.core.item.recipe.network.legacy;
+
+import net.momirealms.craftengine.core.util.Key;
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.Obsolete
+public final class LegacyRecipeTypes {
+    private LegacyRecipeTypes() {}
+
+    public static final Key SHAPED_RECIPE = Key.of("crafting_shaped");
+    public static final Key SHAPELESS_RECIPE = Key.of("crafting_shapeless");
+    public static final Key ARMOR_DYE = Key.of("crafting_special_armordye");
+    public static final Key BOOK_CLONING = Key.of("crafting_special_bookcloning");
+    public static final Key MAP_CLONING = Key.of("crafting_special_mapcloning");
+    public static final Key MAP_EXTENDING = Key.of("crafting_special_mapextending");
+    public static final Key FIREWORK_ROCKET = Key.of("crafting_special_firework_rocket");
+    public static final Key FIREWORK_STAR = Key.of("crafting_special_firework_star");
+    public static final Key FIREWORK_STAR_FADE = Key.of("crafting_special_firework_star_fade");
+    public static final Key TIPPED_ARROW = Key.of("crafting_special_tippedarrow");
+    public static final Key BANNER_DUPLICATE = Key.of("crafting_special_bannerduplicate");
+    public static final Key SHIELD_DECORATION = Key.of("crafting_special_shielddecoration");
+    public static final Key SHULKER_BOX_COLORING = Key.of("crafting_special_shulkerboxcoloring");
+    public static final Key SUSPICIOUS_STEW = Key.of("crafting_special_suspiciousstew");
+    public static final Key REPAIR_ITEM = Key.of("crafting_special_repairitem");
+    public static final Key SMELTING_RECIPE = Key.of("smelting");
+    public static final Key BLASTING_RECIPE = Key.of("blasting");
+    public static final Key SMOKING_RECIPE = Key.of("smoking");
+    public static final Key CAMPFIRE_COOKING_RECIPE = Key.of("campfire_cooking");
+    public static final Key STONECUTTER = Key.of("stonecutting");
+    public static final Key SMITHING_TRANSFORM = Key.of("smithing_transform");
+    public static final Key SMITHING_TRIM = Key.of("smithing_trim");
+    public static final Key DECORATED_POT_RECIPE = Key.of("crafting_decorated_pot");
+
+}

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/legacy/LegacyShapedRecipe.java

@@ -0,0 +1,75 @@
+package net.momirealms.craftengine.core.item.recipe.network.legacy;
+
+import net.momirealms.craftengine.core.item.Item;
+import net.momirealms.craftengine.core.item.recipe.CraftingRecipeCategory;
+import net.momirealms.craftengine.core.plugin.CraftEngine;
+import net.momirealms.craftengine.core.util.FriendlyByteBuf;
+import net.momirealms.craftengine.core.util.Key;
+import net.momirealms.craftengine.core.util.VersionHelper;
+import org.jetbrains.annotations.ApiStatus;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.BiFunction;
+
+@ApiStatus.Obsolete
+public class LegacyShapedRecipe implements LegacyRecipe {
+    private final int width;
+    private final int height;
+    private final List<LegacyIngredient> ingredients;
+    private final Item<?> result;
+    private final Key id;
+    private final String group;
+    private final CraftingRecipeCategory category;
+    private final boolean showNotification;
+
+    public LegacyShapedRecipe(int width, int height, List<LegacyIngredient> ingredients, Item<?> result, Key id, String group, CraftingRecipeCategory category, boolean showNotification) {
+        this.category = category;
+        this.width = width;
+        this.height = height;
+        this.ingredients = ingredients;
+        this.result = result;
+        this.id = id;
+        this.group = group;
+        this.showNotification = showNotification;
+    }
+
+    private static final BiFunction<Key, FriendlyByteBuf, LegacyShapedRecipe> READER = VersionHelper.isOrAbove1_20_3() ?
+            (id, buf) -> {
+                String group = buf.readUtf();
+                int category = buf.readVarInt();
+                int width = buf.readVarInt();
+                int height = buf.readVarInt();
+                int size = width * height;
+                List<LegacyIngredient> ingredients = new ArrayList<>(size);
+                for (int i = 0; i < size; i++) {
+                    ingredients.set(i, LegacyIngredient.read(buf));
+                }
+                Item<?> result = CraftEngine.instance().itemManager().decode(buf);
+                boolean flag = buf.readBoolean();
+                return new LegacyShapedRecipe(width, height, ingredients, result, id, group, CraftingRecipeCategory.byId(category), flag);
+            } :
+            (id, buf) -> {
+                int width = buf.readVarInt();
+                int height = buf.readVarInt();
+                String group = buf.readUtf();
+                int category = buf.readVarInt();
+                int size = width * height;
+                List<LegacyIngredient> ingredients = new ArrayList<>(size);
+                for (int i = 0; i < size; i++) {
+                    ingredients.set(i, LegacyIngredient.read(buf));
+                }
+                Item<?> result = CraftEngine.instance().itemManager().decode(buf);
+                boolean flag = buf.readBoolean();
+                return new LegacyShapedRecipe(width, height, ingredients, result, id, group, CraftingRecipeCategory.byId(category), flag);
+            };
+
+    public static LegacyShapedRecipe read(Key id, FriendlyByteBuf buf) {
+        return READER.apply(id, buf);
+    }
+
+    @Override
+    public void write(FriendlyByteBuf buf) {
+
+    }
+}

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/RecipeBookDisplayEntry.java

@@ -1,8 +1,8 @@
-package net.momirealms.craftengine.core.item.recipe.network;
+package net.momirealms.craftengine.core.item.recipe.network.modern;
 
 import com.mojang.datafixers.util.Either;
 import net.momirealms.craftengine.core.entity.player.Player;
-import net.momirealms.craftengine.core.item.recipe.network.display.RecipeDisplay;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.RecipeDisplay;
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 import net.momirealms.craftengine.core.util.Key;
 import org.jetbrains.annotations.NotNull;

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/RecipeBookEntry.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network;
+package net.momirealms.craftengine.core.item.recipe.network.modern;
 
 import net.momirealms.craftengine.core.entity.player.Player;
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/RecipeDisplayId.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network;
+package net.momirealms.craftengine.core.item.recipe.network.modern;
 
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 import org.jetbrains.annotations.NotNull;

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/FurnaceRecipeDisplay.java

@@ -1,7 +1,7 @@
-package net.momirealms.craftengine.core.item.recipe.network.display;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display;
 
 import net.momirealms.craftengine.core.entity.player.Player;
-import net.momirealms.craftengine.core.item.recipe.network.display.slot.SlotDisplay;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.slot.SlotDisplay;
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 import org.jetbrains.annotations.NotNull;
 

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/RecipeDisplay.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display;
 
 import net.momirealms.craftengine.core.entity.player.Player;
 import net.momirealms.craftengine.core.registry.BuiltInRegistries;

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/RecipeDisplays.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display;
 
 import net.momirealms.craftengine.core.registry.BuiltInRegistries;
 import net.momirealms.craftengine.core.registry.Holder;
@@ -8,6 +8,8 @@ import net.momirealms.craftengine.core.util.Key;
 import net.momirealms.craftengine.core.util.ResourceKey;
 
 public final class RecipeDisplays {
+    private RecipeDisplays() {}
+
     public static final Key CRAFTING_SHAPELESS = Key.of("crafting_shapeless");
     public static final Key CRAFTING_SHAPED = Key.of("crafting_shaped");
     public static final Key FURNACE = Key.of("furnace");

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/ShapedCraftingRecipeDisplay.java

@@ -1,7 +1,7 @@
-package net.momirealms.craftengine.core.item.recipe.network.display;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display;
 
 import net.momirealms.craftengine.core.entity.player.Player;
-import net.momirealms.craftengine.core.item.recipe.network.display.slot.SlotDisplay;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.slot.SlotDisplay;
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 import org.jetbrains.annotations.NotNull;
 

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/ShapelessCraftingRecipeDisplay.java

@@ -1,7 +1,7 @@
-package net.momirealms.craftengine.core.item.recipe.network.display;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display;
 
 import net.momirealms.craftengine.core.entity.player.Player;
-import net.momirealms.craftengine.core.item.recipe.network.display.slot.SlotDisplay;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.slot.SlotDisplay;
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 import org.jetbrains.annotations.NotNull;
 

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/SmithingRecipeDisplay.java

@@ -1,7 +1,7 @@
-package net.momirealms.craftengine.core.item.recipe.network.display;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display;
 
 import net.momirealms.craftengine.core.entity.player.Player;
-import net.momirealms.craftengine.core.item.recipe.network.display.slot.SlotDisplay;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.slot.SlotDisplay;
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 import org.jetbrains.annotations.NotNull;
 

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/StonecutterRecipeDisplay.java

@@ -1,7 +1,7 @@
-package net.momirealms.craftengine.core.item.recipe.network.display;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display;
 
 import net.momirealms.craftengine.core.entity.player.Player;
-import net.momirealms.craftengine.core.item.recipe.network.display.slot.SlotDisplay;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.slot.SlotDisplay;
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 import org.jetbrains.annotations.NotNull;
 

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/slot/AnyFuelDisplay.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display.slot;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display.slot;
 
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/slot/CompositeSlotDisplay.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display.slot;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display.slot;
 
 import net.momirealms.craftengine.core.entity.player.Player;
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/slot/EmptySlotDisplay.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display.slot;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display.slot;
 
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/slot/ItemSlotDisplay.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display.slot;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display.slot;
 
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/slot/ItemStackSlotDisplay.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display.slot;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display.slot;
 
 import net.momirealms.craftengine.core.entity.player.Player;
 import net.momirealms.craftengine.core.item.Item;

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/slot/SlotDisplay.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display.slot;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display.slot;
 
 import net.momirealms.craftengine.core.entity.player.Player;
 import net.momirealms.craftengine.core.registry.BuiltInRegistries;

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/slot/SlotDisplays.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display.slot;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display.slot;
 
 import net.momirealms.craftengine.core.registry.BuiltInRegistries;
 import net.momirealms.craftengine.core.registry.Holder;
@@ -8,6 +8,8 @@ import net.momirealms.craftengine.core.util.Key;
 import net.momirealms.craftengine.core.util.ResourceKey;
 
 public final class SlotDisplays {
+    private SlotDisplays() {}
+
     public static final Key EMPTY = Key.of("empty");
     public static final Key ANY_FUEL = Key.of("any_fuel");
     public static final Key ITEM = Key.of("item");

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/slot/SmithingTrimDemoSlotDisplay.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display.slot;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display.slot;
 
 import com.mojang.datafixers.util.Either;
 import net.kyori.adventure.text.Component;

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/slot/TagSlotDisplay.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display.slot;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display.slot;
 
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 import net.momirealms.craftengine.core.util.Key;

core/src/main/java/net/momirealms/craftengine/core/item/recipe/network/modern/display/slot/WithRemainderSlotDisplay.java

@@ -1,4 +1,4 @@
-package net.momirealms.craftengine.core.item.recipe.network.display.slot;
+package net.momirealms.craftengine.core.item.recipe.network.modern.display.slot;
 
 import net.momirealms.craftengine.core.util.FriendlyByteBuf;
 

core/src/main/java/net/momirealms/craftengine/core/plugin/CraftEngine.java

@@ -7,8 +7,8 @@ import net.momirealms.craftengine.core.entity.projectile.ProjectileManager;
 import net.momirealms.craftengine.core.font.FontManager;
 import net.momirealms.craftengine.core.item.ItemManager;
 import net.momirealms.craftengine.core.item.recipe.RecipeManager;
-import net.momirealms.craftengine.core.item.recipe.network.display.RecipeDisplays;
-import net.momirealms.craftengine.core.item.recipe.network.display.slot.SlotDisplays;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.RecipeDisplays;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.slot.SlotDisplays;
 import net.momirealms.craftengine.core.loot.VanillaLootManager;
 import net.momirealms.craftengine.core.pack.PackManager;
 import net.momirealms.craftengine.core.plugin.classpath.ClassPathAppender;

core/src/main/java/net/momirealms/craftengine/core/registry/BuiltInRegistries.java

@@ -8,8 +8,9 @@ import net.momirealms.craftengine.core.item.behavior.ItemBehaviorFactory;
 import net.momirealms.craftengine.core.item.equipment.EquipmentFactory;
 import net.momirealms.craftengine.core.item.recipe.CustomSmithingTransformRecipe;
 import net.momirealms.craftengine.core.item.recipe.RecipeFactory;
-import net.momirealms.craftengine.core.item.recipe.network.display.RecipeDisplay;
-import net.momirealms.craftengine.core.item.recipe.network.display.slot.SlotDisplay;
+import net.momirealms.craftengine.core.item.recipe.network.legacy.LegacyRecipe;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.RecipeDisplay;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.slot.SlotDisplay;
 import net.momirealms.craftengine.core.loot.LootContext;
 import net.momirealms.craftengine.core.loot.entry.LootEntryContainerFactory;
 import net.momirealms.craftengine.core.loot.function.ApplyBonusCountFunction;
@@ -74,6 +75,7 @@ public class BuiltInRegistries {
     public static final Registry<EquipmentFactory> EQUIPMENT_FACTORY = createRegistry(Registries.EQUIPMENT_FACTORY);
     public static final Registry<SlotDisplay.Type> SLOT_DISPLAY_TYPE = createRegistry(Registries.SLOT_DISPLAY_TYPE);
     public static final Registry<RecipeDisplay.Type> RECIPE_DISPLAY_TYPE = createRegistry(Registries.RECIPE_DISPLAY_TYPE);
+    public static final Registry<LegacyRecipe.Type> LEGACY_RECIPE_TYPE = createRegistry(Registries.LEGACY_RECIPE_TYPE);
 
     private static <T> Registry<T> createRegistry(ResourceKey<? extends Registry<T>> key) {
         return new MappedRegistry<>(key);

core/src/main/java/net/momirealms/craftengine/core/registry/Registries.java

@@ -8,8 +8,9 @@ import net.momirealms.craftengine.core.item.behavior.ItemBehaviorFactory;
 import net.momirealms.craftengine.core.item.equipment.EquipmentFactory;
 import net.momirealms.craftengine.core.item.recipe.CustomSmithingTransformRecipe;
 import net.momirealms.craftengine.core.item.recipe.RecipeFactory;
-import net.momirealms.craftengine.core.item.recipe.network.display.RecipeDisplay;
-import net.momirealms.craftengine.core.item.recipe.network.display.slot.SlotDisplay;
+import net.momirealms.craftengine.core.item.recipe.network.legacy.LegacyRecipe;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.RecipeDisplay;
+import net.momirealms.craftengine.core.item.recipe.network.modern.display.slot.SlotDisplay;
 import net.momirealms.craftengine.core.loot.LootContext;
 import net.momirealms.craftengine.core.loot.entry.LootEntryContainerFactory;
 import net.momirealms.craftengine.core.loot.function.ApplyBonusCountFunction;
@@ -75,4 +76,5 @@ public class Registries {
     public static final ResourceKey<Registry<EquipmentFactory>> EQUIPMENT_FACTORY = new ResourceKey<>(ROOT_REGISTRY, Key.withDefaultNamespace("equipment_factory"));
     public static final ResourceKey<Registry<SlotDisplay.Type>> SLOT_DISPLAY_TYPE = new ResourceKey<>(ROOT_REGISTRY, Key.withDefaultNamespace("slot_display_type"));
     public static final ResourceKey<Registry<RecipeDisplay.Type>> RECIPE_DISPLAY_TYPE = new ResourceKey<>(ROOT_REGISTRY, Key.withDefaultNamespace("recipe_display_type"));
+    public static final ResourceKey<Registry<LegacyRecipe.Type>> LEGACY_RECIPE_TYPE = new ResourceKey<>(ROOT_REGISTRY, Key.withDefaultNamespace("legacy_recipe_type"));
 }

core/src/main/java/net/momirealms/craftengine/core/util/FriendlyByteBuf.java

@@ -21,6 +21,7 @@ import org.jetbrains.annotations.Nullable;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.lang.reflect.Array;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.nio.channels.FileChannel;
@@ -48,20 +49,34 @@ public class FriendlyByteBuf extends ByteBuf {
 
     public <T, C extends Collection<T>> C readCollection(IntFunction<C> collectionFactory, Reader<T> reader) {
         int i = this.readVarInt();
-        C c0 = (C)(collectionFactory.apply(i));
-
+        C collection = collectionFactory.apply(i);
         for(int j = 0; j < i; ++j) {
-            c0.add(reader.apply(this));
+            collection.add(reader.apply(this));
         }
-
-        return c0;
+        return collection;
     }
 
     public <T> void writeCollection(Collection<T> collection, Writer<T> writer) {
         this.writeVarInt(collection.size());
+        for (T t : collection) {
+            writer.accept(this, t);
+        }
+    }
 
-        for (T t0 : collection) {
-            writer.accept(this, t0);
+    @SuppressWarnings("unchecked")
+    public <T> T[] readArray(Reader<T> reader, Class<T> type) {
+        int i = this.readVarInt();
+        T[] array = (T[]) Array.newInstance(type, i);
+        for(int j = 0; j < i; ++j) {
+            array[j] = reader.apply(this);
+        }
+        return array;
+    }
+
+    public <T> void writeArray(T[] array, Writer<T> writer) {
+        this.writeVarInt(array.length);
+        for(T t : array) {
+            writer.accept(this, t);
         }
     }
 

core/src/main/java/net/momirealms/craftengine/core/util/ItemUtils.java

@@ -0,0 +1,12 @@
+package net.momirealms.craftengine.core.util;
+
+import net.momirealms.craftengine.core.item.Item;
+
+public final class ItemUtils {
+    private ItemUtils() {
+    }
+
+    public static boolean isEmpty(Item<?> item) {
+        return item == null || item.isEmpty();
+    }
+}