Add EntityLootGenerateEvent

paper-api/src/main/java/io/papermc/paper/event/entity/EntityLootGenerateEvent.java

@@ -0,0 +1,104 @@
+package io.papermc.paper.event.entity;
+
+import org.bukkit.entity.Entity;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.entity.EntityEvent;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.loot.LootContext;
+import org.bukkit.loot.LootTable;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.NullMarked;
+import java.util.Collection;
+import java.util.List;
+
+/**
+ * Called when a {@link LootTable} is generated for an {@link Entity}.
+ * <br>
+ * For example: When an entity dies, an armadillo sheds, etc.
+ */
+@NullMarked
+public class EntityLootGenerateEvent extends EntityEvent implements Cancellable {
+
+    private static final HandlerList HANDLER_LIST = new HandlerList();
+
+    private final LootTable lootTable;
+    private final LootContext lootContext;
+    private final List<ItemStack> loot;
+
+    private boolean cancelled;
+
+    @ApiStatus.Internal
+    public EntityLootGenerateEvent(Entity entity, LootTable lootTable, LootContext lootContext, List<ItemStack> loot) {
+        super(entity);
+        this.lootTable = lootTable;
+        this.lootContext = lootContext;
+        this.loot = loot;
+    }
+
+    /**
+     * Get the loot table used to generate loot.
+     *
+     * @return the loot table
+     */
+    public LootTable getLootTable() {
+        return this.lootTable;
+    }
+
+    /**
+     * Get the loot context used to provide context to the loot table's loot
+     * generation.
+     *
+     * @return the loot context
+     */
+    public LootContext getLootContext() {
+        return this.lootContext;
+    }
+
+    /**
+     * Set the loot to be generated. {@code null} items will be treated as air.
+     * <br>
+     * Note: the set collection is not the one which will be returned by
+     * {@link #getLoot()}.
+     *
+     * @param loot the loot to generate, {@code null} to clear all loot
+     */
+    public void setLoot(@Nullable Collection<ItemStack> loot) {
+        this.loot.clear();
+        if (loot != null) {
+            this.loot.addAll(loot);
+        }
+    }
+
+    /**
+     * Get a mutable list of all loot to be generated.
+     * <p>
+     * Any items added or removed from the returned list will be reflected in
+     * the loot generation. {@code null} items will be treated as air.
+     *
+     * @return the loot to generate
+     */
+    public List<ItemStack> getLoot() {
+        return this.loot;
+    }
+
+    @Override
+    public void setCancelled(boolean cancel) {
+        this.cancelled = cancel;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return this.cancelled;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return HANDLER_LIST;
+    }
+
+    public static HandlerList getHandlerList() {
+        return HANDLER_LIST;
+    }
+}

paper-api/src/main/java/org/bukkit/event/world/LootGenerateEvent.java

@@ -2,6 +2,7 @@
 
 import java.util.Collection;
 import java.util.List;
+import io.papermc.paper.event.entity.EntityLootGenerateEvent;
 import org.bukkit.World;
 import org.bukkit.entity.Entity;
 import org.bukkit.event.Cancellable;
@@ -19,8 +20,8 @@
  * Called when a {@link LootTable} is generated in the world for an
  * {@link InventoryHolder}.
  * <p>
- * This event is NOT currently called when an entity's loot table has been
- * generated (use {@link EntityDeathEvent#getDrops()}), but WILL be called by
+ * This event is NOT called when an entity's loot table has been
+ * generated (use {@link EntityLootGenerateEvent} or {@link EntityDeathEvent#getDrops()}), but WILL be called by
  * plugins invoking
  * {@link LootTable#fillInventory(org.bukkit.inventory.Inventory, java.util.Random, LootContext)}.
  */

paper-server/patches/features/0005-Entity-Activation-Range-2.0.patch

@@ -354,7 +354,7 @@ index 0000000000000000000000000000000000000000..ce6b57eeeeb1bd652f4bb53c19dcfbc0
 +    }
 +}
 diff --git a/net/minecraft/server/level/ServerLevel.java b/net/minecraft/server/level/ServerLevel.java
-index 89da20b0682708ba8bfc0d10381eb9784d80c395..b5d63d7b848c11ed322d512adeee102886cbb6fd 100644
+index 0fabe7fe4d302695505bed2cef4ce580358b8b82..9fc39230f52f4cf6b44edd34aa9542b9d500538e 100644
 --- a/net/minecraft/server/level/ServerLevel.java
 +++ b/net/minecraft/server/level/ServerLevel.java
 @@ -864,6 +864,7 @@ public class ServerLevel extends Level implements WorldGenLevel, ServerEntityGet
@@ -462,7 +462,7 @@ index 0df8332933203a904bd9ef9efb3c9bce21e65441..1a502cbd8acea9420fa6dd8d716018b5
      public void tick() {
          super.tick();
 diff --git a/net/minecraft/world/entity/Entity.java b/net/minecraft/world/entity/Entity.java
-index 593265d78564b60bacbb4899f18a6e74bf56601d..84c664711658eb83b5ff9d4c8470fd8ec54a5473 100644
+index e5d56fdb5cfd4aa291dbdb879e478134a85c9beb..196a15d3761eab416cb519fd52c86cc100b8080a 100644
 --- a/net/minecraft/world/entity/Entity.java
 +++ b/net/minecraft/world/entity/Entity.java
 @@ -382,6 +382,15 @@ public abstract class Entity
@@ -521,10 +521,10 @@ index 593265d78564b60bacbb4899f18a6e74bf56601d..84c664711658eb83b5ff9d4c8470fd8e
              delta = this.maybeBackOffFromEdge(delta, moverType);
              Vec3 movement = this.collide(delta);
 diff --git a/net/minecraft/world/entity/LivingEntity.java b/net/minecraft/world/entity/LivingEntity.java
-index f62e535b62d249dd3be19d7c1b02fae8dad31c10..6eb95b979ffe37d78fd68eb57ebe71891beb0d28 100644
+index e90339ef63c535c7a376747fcedcd49275612ae3..fdd9ed362c68932a5c3dd7856108243004636d05 100644
 --- a/net/minecraft/world/entity/LivingEntity.java
 +++ b/net/minecraft/world/entity/LivingEntity.java
-@@ -3380,6 +3380,14 @@ public abstract class LivingEntity extends Entity implements Attackable, Waypoin
+@@ -3398,6 +3398,14 @@ public abstract class LivingEntity extends Entity implements Attackable, Waypoin
      protected void playAttackSound() {
      }
 
@@ -818,7 +818,7 @@ index f46cca0467bb4da5511bc953ce5b43fa606bf978..445c5cafad71028171c1f26193966177
 +
  }
 diff --git a/net/minecraft/world/level/Level.java b/net/minecraft/world/level/Level.java
-index cc492445307ddc08446484d272866f01646cf7b3..a5d46832d4f8a13b0bf67b523c21d5c3b44209a9 100644
+index 46ca14a186f23a05bd0e6437adcb67dc09d94d8b..00bfadc908cfa9f1600c4bcc3cd21cca579cdc4f 100644
 --- a/net/minecraft/world/level/Level.java
 +++ b/net/minecraft/world/level/Level.java
 @@ -155,6 +155,12 @@ public abstract class Level implements LevelAccessor, AutoCloseable, ca.spottedl

paper-server/patches/sources/net/minecraft/world/entity/LivingEntity.java.patch

@@ -966,6 +966,41 @@
      }
 
      protected void dropCustomDeathLoot(final ServerLevel level, final DamageSource source, final boolean killedByPlayer) {
+@@ -1546,8 +_,18 @@
+             builder = builder.withParameter(LootContextParams.LAST_DAMAGE_PLAYER, killerPlayer).withLuck(killerPlayer.getLuck());
+         }
+
++        // Paper start - EntityLootGenerateEvent
++        List<ItemStack> drops = new it.unimi.dsi.fastutil.objects.ObjectArrayList<>();
+         LootParams params = builder.create(LootContextParamSets.ENTITY);
+-        table.getRandomItems(params, this.getLootTableSeed(), itemStackConsumer);
++        table.getRandomItems(params, this.getLootTableSeed(), drops::add);
++
++        List<org.bukkit.inventory.ItemStack> bukkitLoot = drops.stream().map(CraftItemStack::asCraftMirror).collect(java.util.stream.Collectors.toCollection(java.util.ArrayList::new));
++        io.papermc.paper.event.entity.EntityLootGenerateEvent event = new io.papermc.paper.event.entity.EntityLootGenerateEvent(this.getBukkitEntity(), table.craftLootTable, org.bukkit.craftbukkit.CraftLootTable.convertParams(params), bukkitLoot);
++        if (!event.callEvent()) {
++            return;
++        }
++        event.getLoot().stream().map(org.bukkit.craftbukkit.inventory.CraftItemStack::asNMSCopy).forEach(itemStackConsumer);
++        // Paper end
+     }
+
+     public boolean dropFromEntityInteractLootTable(
+@@ -1602,6 +_,14 @@
+         LootTable lootTable = level.getServer().reloadableRegistries().getLootTable(key);
+         LootParams params = paramsBuilder.apply(new LootParams.Builder(level));
+         List<ItemStack> drops = lootTable.getRandomItems(params);
++        // Paper start - EntityLootGenerateEvent
++        List<org.bukkit.inventory.ItemStack> bukkitLoot = drops.stream().map(CraftItemStack::asCraftMirror).collect(java.util.stream.Collectors.toCollection(java.util.ArrayList::new));
++        io.papermc.paper.event.entity.EntityLootGenerateEvent event = new io.papermc.paper.event.entity.EntityLootGenerateEvent(this.getBukkitEntity(), lootTable.craftLootTable, org.bukkit.craftbukkit.CraftLootTable.convertParams(params), bukkitLoot);
++        if (!event.callEvent()) {
++            return false;
++        }
++        drops = event.getLoot().stream().map(org.bukkit.craftbukkit.inventory.CraftItemStack::asNMSCopy).collect(it.unimi.dsi.fastutil.objects.ObjectArrayList.toList());
++        // Paper end
+         if (!drops.isEmpty()) {
+             drops.forEach(stack -> consumer.accept(level, stack));
+             return true;
 @@ -1611,9 +_,14 @@
      }
 

paper-server/src/main/java/org/bukkit/craftbukkit/CraftLootTable.java

@@ -148,6 +148,29 @@ private <T> void setMaybe(LootParams.Builder builder, ContextKey<T> param, T val
         }
     }
 
+    public static LootContext convertParams(net.minecraft.world.level.storage.loot.LootParams info) {
+        Vec3 position = info.contextMap().getOptional(LootContextParams.ORIGIN);
+        if (position == null) {
+            position = info.contextMap().getOptional(LootContextParams.THIS_ENTITY).position(); // Every vanilla context has origin or this_entity, see LootContextParamSets
+        }
+        Location location = CraftLocation.toBukkit(position, info.getLevel());
+        LootContext.Builder contextBuilder = new LootContext.Builder(location);
+
+        if (info.contextMap().has(LootContextParams.ATTACKING_ENTITY)) {
+            CraftEntity killer = info.contextMap().getOptional(LootContextParams.ATTACKING_ENTITY).getBukkitEntity();
+            if (killer instanceof CraftHumanEntity) {
+                contextBuilder.killer((CraftHumanEntity) killer);
+            }
+        }
+
+        if (info.contextMap().has(LootContextParams.THIS_ENTITY)) {
+            contextBuilder.lootedEntity(info.contextMap().getOptional(LootContextParams.THIS_ENTITY).getBukkitEntity());
+        }
+
+        contextBuilder.luck(info.getLuck());
+        return contextBuilder.build();
+    }
+
     public static LootContext convertContext(net.minecraft.world.level.storage.loot.LootContext info) {
         Vec3 position = info.getOptionalParameter(LootContextParams.ORIGIN);
         if (position == null) {