Add an event that allows to modify the looting level based on damage source

patches/minecraft/net/minecraft/entity/EntityLivingBase.java.patch

@@ -76,9 +76,11 @@
          if (!this.field_70729_aU)
          {
              Entity entity = p_70645_1_.func_76346_g();
-@@ -1070,11 +1076,24 @@
+@@ -1069,12 +1075,26 @@
+                 {
                      i = EnchantmentHelper.func_185283_h((EntityLivingBase)entity);
                  }
++                i = net.minecraftforge.common.ForgeHooks.getLootingLevel(this, p_70645_1_, i);
  
 +                captureDrops = true;
 +                capturedDrops.clear();

src/main/java/net/minecraftforge/common/ForgeHooks.java

@@ -109,6 +109,7 @@ import net.minecraftforge.event.entity.living.LivingEvent.LivingUpdateEvent;
 import net.minecraftforge.event.entity.living.LivingFallEvent;
 import net.minecraftforge.event.entity.living.LivingHurtEvent;
 import net.minecraftforge.event.entity.living.LivingSetAttackTargetEvent;
+import net.minecraftforge.event.entity.living.LootingLevelEvent;
 import net.minecraftforge.event.entity.player.AnvilRepairEvent;
 import net.minecraftforge.event.entity.player.AttackEntityEvent;
 import net.minecraftforge.event.entity.player.PlayerInteractEvent;
@@ -515,6 +516,12 @@ public class ForgeHooks
         return (MinecraftForge.EVENT_BUS.post(event) ? null : new float[]{event.getDistance(), event.getDamageMultiplier()});
     }
 
+    public static int getLootingLevel(EntityLivingBase target, DamageSource cause, int level) {
+        LootingLevelEvent event = new LootingLevelEvent(target, cause, level);
+        MinecraftForge.EVENT_BUS.post(event);
+        return event.getLootingLevel();
+    }
+
     public static boolean isLivingOnLadder(IBlockState state, World world, BlockPos pos, EntityLivingBase entity)
     {
         boolean isSpectator = (entity instanceof EntityPlayer && ((EntityPlayer)entity).isSpectator());

src/main/java/net/minecraftforge/event/entity/living/LootingLevelEvent.java

@@ -0,0 +1,29 @@
+package net.minecraftforge.event.entity.living;
+
+import net.minecraft.entity.EntityLivingBase;
+import net.minecraft.util.DamageSource;
+
+public class LootingLevelEvent extends LivingEvent {
+
+    private final DamageSource damageSource;
+
+    private int lootingLevel;
+
+    public LootingLevelEvent(EntityLivingBase entity, DamageSource damageSource, int lootingLevel) {
+        super(entity);
+        this.damageSource = damageSource;
+        this.lootingLevel = lootingLevel;
+    }
+
+    public DamageSource getDamageSource() {
+        return damageSource;
+    }
+
+    public int getLootingLevel() {
+        return lootingLevel;
+    }
+
+    public void setLootingLevel(int lootingLevel) {
+        this.lootingLevel = lootingLevel;
+    }
+}

src/test/java/net/minecraftforge/debug/LootTablesDebug.java

@@ -1,6 +1,9 @@
 package net.minecraftforge.debug;
 
+import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.entity.projectile.EntityArrow;
 import net.minecraft.init.Items;
+import net.minecraft.util.DamageSource;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.world.storage.loot.LootEntryItem;
 import net.minecraft.world.storage.loot.LootPool;
@@ -9,6 +12,7 @@ import net.minecraft.world.storage.loot.conditions.LootCondition;
 import net.minecraft.world.storage.loot.functions.LootFunction;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.event.LootTableLoadEvent;
+import net.minecraftforge.event.entity.living.LootingLevelEvent;
 import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.event.FMLInitializationEvent;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
@@ -39,4 +43,13 @@ public class LootTablesDebug {
         // Get rid of all building mats. Which is pool #3, index starts at 0, but 0 is named "main"
         event.getTable().removePool("pool3");
     }
+
+    @SubscribeEvent
+    public void lootingEvent(LootingLevelEvent event) {
+        // if the player shoots something with a projectile, use looting 3
+        DamageSource damageSource = event.getDamageSource();
+        if(damageSource.isProjectile() && damageSource.getEntity() instanceof EntityPlayer && damageSource.getSourceOfDamage() instanceof EntityArrow) {
+            event.setLootingLevel(3);
+        }
+    }
 }