Paper/Spigot-Server-Patches/0142-Make-entities-look-for-hoppers.patch

From 85cc2d8515551c826977868bf3c68b1d78cccead Mon Sep 17 00:00:00 2001
From: Techcable <Techcable@outlook.com>
Date: Sat, 18 Jun 2016 01:01:37 -0500
Subject: [PATCH] Make entities look for hoppers

Every tick hoppers try and find an block-inventory to extract from.
If no tile entity is above the hopper (which there often isn't) it will do a bounding box search for minecart chests and minecart hoppers.
If it can't find an inventory, it will then look for a dropped item, which is another bounding box search.
This patch eliminates that expensive check by having dropped items and minecart hoppers/chests look for hoppers instead.
Hoppers are tile entities meaning you can do a simple tile entity lookup to find the nearest hopper in range.
Pushing out of hoppers causes a bouding box lookup, which this patch replaces with a tile entity lookup.

This patch may causes a decrease in the performance of dropped items, which is why it can be disabled in the configuration.

diff --git a/src/main/java/com/destroystokyo/paper/HopperPusher.java b/src/main/java/com/destroystokyo/paper/HopperPusher.java
new file mode 100644
index 000000000..52457e3d8
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/HopperPusher.java
@@ -0,0 +1,60 @@
+package com.destroystokyo.paper;
+
+import net.minecraft.server.AxisAlignedBB;
+import net.minecraft.server.BlockPosition;
+import net.minecraft.server.MCUtil;
+import net.minecraft.server.TileEntityHopper;
+import net.minecraft.server.World;
+
+public interface HopperPusher {
+
+    default TileEntityHopper findHopper() {
+        BlockPosition pos = new BlockPosition(getX(), getY(), getZ());
+        int startX = pos.getX() - 1;
+        int endX = pos.getX() + 1;
+        int startY = Math.max(0, pos.getY() - 1);
+        int endY = Math.min(255, pos.getY() + 1);
+        int startZ = pos.getZ() - 1;
+        int endZ = pos.getZ() + 1;
+        BlockPosition.PooledBlockPosition adjacentPos = BlockPosition.PooledBlockPosition.aquire();
+        for (int x = startX; x <= endX; x++) {
+            for (int y = startY; y <= endY; y++) {
+                for (int z = startZ; z <= endZ; z++) {
+                    adjacentPos.setValues(x, y, z);
+                    TileEntityHopper hopper = MCUtil.getHopper(getWorld(), adjacentPos);
+                    if (hopper == null) continue; // Avoid playing with the bounding boxes, if at all possible
+                    AxisAlignedBB hopperBoundingBox = hopper.getHopperLookupBoundingBox();
+                    /*
+                     * Check if the entity's bounding box intersects with the hopper's lookup box.
+                     * This operation doesn't work both ways!
+                     * Make sure you check if the entity's box intersects the hopper's box, not vice versa!
+                     */
+                    AxisAlignedBB boundingBox = this.getBoundingBox().shrink(0.1); // Imitate vanilla behavior
+                    if (boundingBox.intersects(hopperBoundingBox)) {
+                        return hopper;
+                    }
+                }
+            }
+        }
+        adjacentPos.free();
+        return null;
+    }
+
+    boolean acceptItem(TileEntityHopper hopper);
+
+    default boolean tryPutInHopper() {
+        if (!getWorld().paperConfig.isHopperPushBased) return false;
+        TileEntityHopper hopper = findHopper();
+        return hopper != null && hopper.canAcceptItems() && acceptItem(hopper);
+    }
+
+    AxisAlignedBB getBoundingBox();
+
+    World getWorld();
+
+    double getX();
+
+    double getY();
+
+    double getZ();
+}
diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index 600e603bd..ce43e7bb7 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -339,4 +339,9 @@ public class PaperWorldConfig {
     private void altFallingBlockOnGround() {
         altFallingBlockOnGround = getBoolean("use-alternate-fallingblock-onGround-detection", false);
     }
+
+    public boolean isHopperPushBased;
+    private void isHopperPushBased() {
+        isHopperPushBased = getBoolean("hopper.push-based", false);
+    }
 }
diff --git a/src/main/java/net/minecraft/server/AxisAlignedBB.java b/src/main/java/net/minecraft/server/AxisAlignedBB.java
index 1eb9c2da8..c88b76a79 100644
--- a/src/main/java/net/minecraft/server/AxisAlignedBB.java
+++ b/src/main/java/net/minecraft/server/AxisAlignedBB.java
@@ -235,6 +235,7 @@ public class AxisAlignedBB {
         }
     }
 
+    public final boolean intersects(AxisAlignedBB intersecting) { return this.c(intersecting); } // Paper - OBFHELPER
     public boolean c(AxisAlignedBB axisalignedbb) {
         return this.a(axisalignedbb.a, axisalignedbb.b, axisalignedbb.c, axisalignedbb.d, axisalignedbb.e, axisalignedbb.f);
     }
diff --git a/src/main/java/net/minecraft/server/BlockPosition.java b/src/main/java/net/minecraft/server/BlockPosition.java
index 008ed206d..b3c1f550c 100644
--- a/src/main/java/net/minecraft/server/BlockPosition.java
+++ b/src/main/java/net/minecraft/server/BlockPosition.java
@@ -250,6 +250,7 @@ public class BlockPosition extends BaseBlockPosition {
             super(i, j, k);
         }
 
+        public static BlockPosition.PooledBlockPosition aquire() { return s(); } // Paper - OBFHELPER
         public static BlockPosition.PooledBlockPosition s() {
             return e(0, 0, 0);
         }
@@ -276,6 +277,7 @@ public class BlockPosition extends BaseBlockPosition {
             return new BlockPosition.PooledBlockPosition(i, j, k);
         }
 
+        public void free() { t(); } // Paper - OBFHELPER
         public void t() {
             List list = BlockPosition.PooledBlockPosition.g;
 
@@ -393,6 +395,7 @@ public class BlockPosition extends BaseBlockPosition {
             return this.d;
         }
 
+        public void setValues(int x, int y, int z) { c(x, y, z); } // Paper - OBFHELPER
         public BlockPosition.MutableBlockPosition c(int i, int j, int k) {
             this.b = i;
             this.c = j;
diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index 0a62ebf4a..0950c315f 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -93,6 +93,19 @@ public abstract class Entity implements ICommandListener, KeyedObject { // Paper
     public double locX;
     public double locY;
     public double locZ;
+    // Paper start - getters to implement HopperPusher
+    public double getX() {
+        return locX;
+    }
+
+    public double getY() {
+        return locY;
+    }
+
+    public double getZ() {
+        return locZ;
+    }
+    // Paper end
     public double motX;
     public double motY;
     public double motZ;
diff --git a/src/main/java/net/minecraft/server/EntityItem.java b/src/main/java/net/minecraft/server/EntityItem.java
index 4d3aef96b..6593fc633 100644
--- a/src/main/java/net/minecraft/server/EntityItem.java
+++ b/src/main/java/net/minecraft/server/EntityItem.java
@@ -8,8 +8,15 @@ import org.apache.logging.log4j.Logger;
 import org.bukkit.event.entity.EntityPickupItemEvent;
 import org.bukkit.event.player.PlayerPickupItemEvent;
 // CraftBukkit end
+import com.destroystokyo.paper.HopperPusher; // Paper
 
-public class EntityItem extends Entity {
+// Paper start - implement HopperPusher
+public class EntityItem extends Entity implements HopperPusher {
+    @Override
+    public boolean acceptItem(TileEntityHopper hopper) {
+        return TileEntityHopper.putDropInInventory(null, hopper, this);
+    }
+// Paper end
 
     private static final Logger b = LogManager.getLogger();
     private static final DataWatcherObject<ItemStack> c = DataWatcher.a(EntityItem.class, DataWatcherRegistry.f);
@@ -59,6 +66,7 @@ public class EntityItem extends Entity {
             this.die();
         } else {
             super.B_();
+            if (tryPutInHopper()) return; // Paper
             // CraftBukkit start - Use wall time for pickup and despawn timers
             int elapsedTicks = MinecraftServer.currentTick - this.lastTick;
             if (this.pickupDelay != 32767) this.pickupDelay -= elapsedTicks;
@@ -146,6 +154,7 @@ public class EntityItem extends Entity {
     // Spigot start - copied from above
     @Override
     public void inactiveTick() {
+        if (tryPutInHopper()) return; // Paper
         // CraftBukkit start - Use wall time for pickup and despawn timers
         int elapsedTicks = MinecraftServer.currentTick - this.lastTick;
         if (this.pickupDelay != 32767) this.pickupDelay -= elapsedTicks;
diff --git a/src/main/java/net/minecraft/server/EntityMinecartContainer.java b/src/main/java/net/minecraft/server/EntityMinecartContainer.java
index 50d7d34b8..15f392d23 100644
--- a/src/main/java/net/minecraft/server/EntityMinecartContainer.java
+++ b/src/main/java/net/minecraft/server/EntityMinecartContainer.java
@@ -7,6 +7,7 @@ import javax.annotation.Nullable;
 import java.util.List;
 import org.bukkit.Location;
 
+import com.destroystokyo.paper.HopperPusher; // Paper
 import com.destroystokyo.paper.loottable.CraftLootableInventoryData; // Paper
 import com.destroystokyo.paper.loottable.CraftLootableInventory; // Paper
 import com.destroystokyo.paper.loottable.LootableInventory; // Paper
@@ -15,7 +16,25 @@ import org.bukkit.entity.HumanEntity;
 import org.bukkit.inventory.InventoryHolder;
 // CraftBukkit end
 
-public abstract class EntityMinecartContainer extends EntityMinecartAbstract implements ITileInventory, ILootable, CraftLootableInventory { // Paper
+// Paper start - push into hoppers
+public abstract class EntityMinecartContainer extends EntityMinecartAbstract implements ITileInventory, ILootable, CraftLootableInventory, HopperPusher { // Paper - CraftLootableInventory
+    @Override
+    public boolean acceptItem(TileEntityHopper hopper) {
+        return TileEntityHopper.acceptItem(hopper, this);
+    }
+
+    @Override
+    public void B_() {
+        super.B_();
+        tryPutInHopper();
+    }
+
+    @Override
+    public void inactiveTick() {
+        super.inactiveTick();
+        tryPutInHopper();
+    }
+    // Paper end
 
     private NonNullList<ItemStack> items;
     private boolean b;
diff --git a/src/main/java/net/minecraft/server/IHopper.java b/src/main/java/net/minecraft/server/IHopper.java
index 804215a1c..e830d8390 100644
--- a/src/main/java/net/minecraft/server/IHopper.java
+++ b/src/main/java/net/minecraft/server/IHopper.java
@@ -4,9 +4,9 @@ public interface IHopper extends IInventory {
 
     World getWorld();
 
-    double E();
+    double E(); default double getX() { return E(); } // Paper - OBFHELPER
 
-    double F();
+    double F(); default double getY() { return F(); } // Paper - OBFHELPER
 
-    double G();
+    double G(); default double getZ() { return G(); } // Paper - OBFHELPER
 }
diff --git a/src/main/java/net/minecraft/server/TileEntityHopper.java b/src/main/java/net/minecraft/server/TileEntityHopper.java
index 985513511..e9315f2d5 100644
--- a/src/main/java/net/minecraft/server/TileEntityHopper.java
+++ b/src/main/java/net/minecraft/server/TileEntityHopper.java
@@ -126,6 +126,7 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
     }
 
     private boolean o() {
+        mayAcceptItems = false; // Paper - at the beginning of a tick, assume we can't accept items
         if (this.world != null && !this.world.isClientSide) {
             if (!this.J() && BlockHopper.f(this.v())) {
                 boolean flag = false;
@@ -135,6 +136,7 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
                 }
 
                 if (!this.r()) {
+                    mayAcceptItems = true; // Paper - flag this hopper to be able to accept items
                     flag = a((IHopper) this) || flag;
                 }
 
@@ -150,6 +152,14 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
         }
     }
 
+    // Paper start
+    private boolean mayAcceptItems = false;
+
+    public boolean canAcceptItems() {
+        return mayAcceptItems;
+    }
+    // Paper end
+
     private boolean p() {
         Iterator iterator = this.items.iterator();
 
@@ -300,8 +310,15 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
         return true;
     }
 
+    // Paper start - split methods, and only do entity lookup if in pull mode
     public static boolean a(IHopper ihopper) {
-        IInventory iinventory = b(ihopper);
+        IInventory iinventory = getInventory(ihopper, !(ihopper instanceof TileEntityHopper) || !ihopper.getWorld().paperConfig.isHopperPushBased);
+
+        return acceptItem(ihopper, iinventory);
+    }
+
+    public static boolean acceptItem(IHopper ihopper, IInventory iinventory) {
+        // Paper end
 
         if (iinventory != null) {
             EnumDirection enumdirection = EnumDirection.DOWN;
@@ -332,8 +349,8 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
                     }
                 }
             }
-        } else {
-            Iterator iterator = a(ihopper.getWorld(), ihopper.E(), ihopper.F(), ihopper.G()).iterator();
+        } else if (!ihopper.getWorld().paperConfig.isHopperPushBased || !(ihopper instanceof TileEntityHopper)) { // Paper - only search for entities in 'pull mode'
+            Iterator iterator = a(ihopper.getWorld(), ihopper.E(), ihopper.F(), ihopper.G()).iterator(); // Change getHopperLookupBoundingBox() if this ever changes
 
             while (iterator.hasNext()) {
                 EntityItem entityitem = (EntityItem) iterator.next();
@@ -397,6 +414,7 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
         return false;
     }
 
+    public static boolean putDropInInventory(IInventory iinventory, IInventory iinventory1, EntityItem entityitem) { return a(iinventory, iinventory1, entityitem); } // Paper - OBFHELPER
     public static boolean a(IInventory iinventory, IInventory iinventory1, EntityItem entityitem) {
         boolean flag = false;
 
@@ -500,18 +518,44 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
     private IInventory I() {
         EnumDirection enumdirection = BlockHopper.b(this.v());
 
-        return b(this.getWorld(), this.E() + (double) enumdirection.getAdjacentX(), this.F() + (double) enumdirection.getAdjacentY(), this.G() + (double) enumdirection.getAdjacentZ());
+        // Paper start - don't search for entities in push mode
+        World world = getWorld();
+        return getInventory(world, this.E() + (double) enumdirection.getAdjacentX(), this.F() + (double) enumdirection.getAdjacentY(), this.G() + (double) enumdirection.getAdjacentZ(), !world.paperConfig.isHopperPushBased);
+        // Paper end
     }
 
-    public static IInventory b(IHopper ihopper) {
-        return b(ihopper.getWorld(), ihopper.E(), ihopper.F() + 1.0D, ihopper.G());
+    // Paper start - add option to search for entities
+    public static IInventory b(IHopper hopper) {
+        return getInventory(hopper, true);
+    }
+
+    public static IInventory getInventory(IHopper ihopper, boolean searchForEntities) {
+        return getInventory(ihopper.getWorld(), ihopper.E(), ihopper.F() + 1.0D, ihopper.G(), searchForEntities);
+        // Paper end
     }
 
     public static List<EntityItem> a(World world, double d0, double d1, double d2) {
-        return world.a(EntityItem.class, new AxisAlignedBB(d0 - 0.5D, d1, d2 - 0.5D, d0 + 0.5D, d1 + 1.5D, d2 + 0.5D), IEntitySelector.a);
+        return world.a(EntityItem.class, new AxisAlignedBB(d0 - 0.5D, d1, d2 - 0.5D, d0 + 0.5D, d1 + 1.5D, d2 + 0.5D), IEntitySelector.a); // Change getHopperLookupBoundingBox(double, double, double) if the bounding box calculation is ever changed
+    }
+
+    // Paper start
+    public AxisAlignedBB getHopperLookupBoundingBox() {
+        return getHopperLookupBoundingBox(this.getX(), this.getY(), this.getZ());
     }
 
+    private static AxisAlignedBB getHopperLookupBoundingBox(double d0, double d1, double d2) {
+        // Change this if a(World, double, double, double) above ever changes
+        return new AxisAlignedBB(d0 - 0.5D, d1, d2 - 0.5D, d0 + 0.5D, d1 + 1.5D, d2 + 0.5D);
+    }
+    // Paper end
+
+    // Paper start - add option to searchForEntities
     public static IInventory b(World world, double d0, double d1, double d2) {
+        return getInventory(world, d0, d1, d2, true);
+    }
+
+    public static IInventory getInventory(World world, double d0, double d1, double d2, boolean searchForEntities) {
+        // Paper end
         Object object = null;
         int i = MathHelper.floor(d0);
         int j = MathHelper.floor(d1);
@@ -531,7 +575,7 @@ public class TileEntityHopper extends TileEntityLootable implements IHopper, ITi
             }
         }
 
-        if (object == null) {
+        if (object == null && searchForEntities) { // Paper - only if searchForEntities
             List list = world.getEntities((Entity) null, new AxisAlignedBB(d0 - 0.5D, d1 - 0.5D, d2 - 0.5D, d0 + 0.5D, d1 + 0.5D, d2 + 0.5D), IEntitySelector.c);
 
             if (!list.isEmpty()) {
-- 
2.18.0