From fcf34927ee0a09db8755a8bff558a72be6a2d624 Mon Sep 17 00:00:00 2001
From: Byteflux <byte@byteflux.net>
Date: Tue, 1 Mar 2016 23:45:08 -0600
Subject: [PATCH] Entity Origin API


diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index f5647a171d..205376f6af 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -163,6 +163,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     public org.bukkit.projectiles.ProjectileSource projectileSource; // For projectiles only
     public boolean forceExplosionKnockback; // SPIGOT-949
     public Timing tickTimer = MinecraftTimings.getEntityTimings(this); // Paper
+    public Location origin; // Paper
     // Spigot start
     public final org.spigotmc.ActivationRange.ActivationType activationType = org.spigotmc.ActivationRange.initializeEntityActivationType(this);
     public final boolean defaultActivationState;
@@ -1546,6 +1547,11 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
                 this.bukkitEntity.storeBukkitValues(nbttagcompound);
             }
             // CraftBukkit end
+            // Paper start - Save the entity's origin location
+            if (this.origin != null) {
+                nbttagcompound.set("Paper.Origin", this.createList(origin.getX(), origin.getY(), origin.getZ()));
+            }
+            // Paper end
             return nbttagcompound;
         } catch (Throwable throwable) {
             CrashReport crashreport = CrashReport.a(throwable, "Saving entity NBT");
@@ -1668,6 +1674,13 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
             this.getBukkitEntity().readBukkitValues(nbttagcompound);
             // CraftBukkit end
 
+            // Paper start - Restore the entity's origin location
+            NBTTagList originTag = nbttagcompound.getList("Paper.Origin", 6);
+            if (!originTag.isEmpty()) {
+                origin = new Location(world.getWorld(), originTag.getDoubleAt(0), originTag.getDoubleAt(1), originTag.getDoubleAt(2));
+            }
+            // Paper end
+
         } catch (Throwable throwable) {
             CrashReport crashreport = CrashReport.a(throwable, "Loading entity NBT");
             CrashReportSystemDetails crashreportsystemdetails = crashreport.a("Entity being loaded");
@@ -1745,6 +1758,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
 
     protected abstract void b(NBTTagCompound nbttagcompound);
 
+    protected NBTTagList createList(double... adouble) { return a(adouble); } // Paper - OBFHELPER
     protected NBTTagList a(double... adouble) {
         NBTTagList nbttaglist = new NBTTagList();
         double[] adouble1 = adouble;
diff --git a/src/main/java/net/minecraft/server/EntityFallingBlock.java b/src/main/java/net/minecraft/server/EntityFallingBlock.java
index a4984aa9a8..23a1f8c77c 100644
--- a/src/main/java/net/minecraft/server/EntityFallingBlock.java
+++ b/src/main/java/net/minecraft/server/EntityFallingBlock.java
@@ -253,6 +253,14 @@ public class EntityFallingBlock extends Entity {
             this.block = Blocks.SAND.getBlockData();
         }
 
+        // Paper start - Try and load origin location from the old NBT tags for backwards compatibility
+        if (nbttagcompound.hasKey("SourceLoc_x")) {
+            int srcX = nbttagcompound.getInt("SourceLoc_x");
+            int srcY = nbttagcompound.getInt("SourceLoc_y");
+            int srcZ = nbttagcompound.getInt("SourceLoc_z");
+            origin = new org.bukkit.Location(world.getWorld(), srcX, srcY, srcZ);
+        }
+        // Paper end
     }
 
     public void a(boolean flag) {
diff --git a/src/main/java/net/minecraft/server/EntityTNTPrimed.java b/src/main/java/net/minecraft/server/EntityTNTPrimed.java
index e3001570f9..e0535604b6 100644
--- a/src/main/java/net/minecraft/server/EntityTNTPrimed.java
+++ b/src/main/java/net/minecraft/server/EntityTNTPrimed.java
@@ -104,6 +104,14 @@ public class EntityTNTPrimed extends Entity {
     @Override
     protected void a(NBTTagCompound nbttagcompound) {
         this.setFuseTicks(nbttagcompound.getShort("Fuse"));
+        // Paper start - Try and load origin location from the old NBT tags for backwards compatibility
+        if (nbttagcompound.hasKey("SourceLoc_x")) {
+            int srcX = nbttagcompound.getInt("SourceLoc_x");
+            int srcY = nbttagcompound.getInt("SourceLoc_y");
+            int srcZ = nbttagcompound.getInt("SourceLoc_z");
+            origin = new org.bukkit.Location(world.getWorld(), srcX, srcY, srcZ);
+        }
+        // Paper end
     }
 
     @Nullable
diff --git a/src/main/java/net/minecraft/server/NBTTagList.java b/src/main/java/net/minecraft/server/NBTTagList.java
index ce510c4867..b7c94fe238 100644
--- a/src/main/java/net/minecraft/server/NBTTagList.java
+++ b/src/main/java/net/minecraft/server/NBTTagList.java
@@ -161,6 +161,7 @@ public class NBTTagList extends NBTList<NBTBase> {
         return new int[0];
     }
 
+    public final double getDoubleAt(int i) { return this.h(i); } // Paper - OBFHELPER
     public double h(int i) {
         if (i >= 0 && i < this.list.size()) {
             NBTBase nbtbase = (NBTBase) this.list.get(i);
diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
index 089468835b..fc582fead6 100644
--- a/src/main/java/net/minecraft/server/WorldServer.java
+++ b/src/main/java/net/minecraft/server/WorldServer.java
@@ -1095,6 +1095,11 @@ public class WorldServer extends World {
                 this.I.add(((EntityInsentient) entity).getNavigation());
             }
             entity.valid = true; // CraftBukkit
+            // Paper start - Set origin location when the entity is being added to the world
+            if (entity.origin == null) {
+                entity.origin = entity.getBukkitEntity().getLocation();
+            }
+            // Paper end
         }
 
     }
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
index a98f6f3389..d1d37c06bf 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
@@ -1009,4 +1009,12 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
         return spigot;
     }
     // Spigot end
+
+    // Paper start
+    @Override
+    public Location getOrigin() {
+        Location origin = getHandle().origin;
+        return origin == null ? null : origin.clone();
+    }
+    // Paper end
 }
-- 
2.22.0

