Paper/patches/server/0033-Entity-Origin-API.patch

From 0000000000000000000000000000000000000000 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/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index 0653b5abc89d0c5a54566e3e518cfd29db076b86..bc2111031f277dc27b8ae673259a10999df1ec43 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -2399,6 +2399,15 @@ public class ServerLevel extends Level implements WorldGenLevel {
             entity.updateDynamicGameEventListener(DynamicGameEventListener::add);
             entity.inWorld = true; // CraftBukkit - Mark entity as in world
             entity.valid = true; // CraftBukkit
+            // Paper start - Set origin location when the entity is being added to the world
+            if (entity.getOriginVector() == null) {
+                entity.setOrigin(entity.getBukkitEntity().getLocation());
+            }
+            // Default to current world if unknown, gross assumption but entities rarely change world
+            if (entity.getOriginWorld() == null) {
+                entity.setOrigin(entity.getOriginVector().toLocation(getWorld()));
+            }
+            // Paper end
         }
 
         public void onTrackingEnd(Entity entity) {
diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index fa3d294b36eb0c23b293466fc72bd2970a452b55..9f3598371c854ec74f3b5752c9779d6c0d99ec39 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -317,7 +317,27 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, S
     public long activatedTick = Integer.MIN_VALUE;
     public void inactiveTick() { }
     // Spigot end
+    // Paper start
+    @javax.annotation.Nullable
+    private org.bukkit.util.Vector origin;
+    @javax.annotation.Nullable
+    private UUID originWorld;
+
+    public void setOrigin(@javax.annotation.Nonnull Location location) {
+        this.origin = location.toVector();
+        this.originWorld = location.getWorld().getUID();
+    }
 
+    @javax.annotation.Nullable
+    public org.bukkit.util.Vector getOriginVector() {
+        return this.origin != null ? this.origin.clone() : null;
+    }
+
+    @javax.annotation.Nullable
+    public UUID getOriginWorld() {
+        return this.originWorld;
+    }
+    // Paper end
     public float getBukkitYaw() {
         return this.yRot;
     }
@@ -2093,6 +2113,15 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, S
                 this.bukkitEntity.storeBukkitValues(nbttagcompound);
             }
             // CraftBukkit end
+            // Paper start - Save the entity's origin location
+            if (this.origin != null) {
+                UUID originWorld = this.originWorld != null ? this.originWorld : this.level != null ? this.level.getWorld().getUID() : null;
+                if (originWorld != null) {
+                    nbttagcompound.putUUID("Paper.OriginWorld", originWorld);
+                }
+                nbttagcompound.put("Paper.Origin", this.newDoubleList(origin.getX(), origin.getY(), origin.getZ()));
+            }
+            // Paper end
             return nbttagcompound;
         } catch (Throwable throwable) {
             CrashReport crashreport = CrashReport.forThrowable(throwable, "Saving entity NBT");
@@ -2220,6 +2249,20 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, S
             }
             // CraftBukkit end
 
+            // Paper start - Restore the entity's origin location
+            ListTag originTag = nbt.getList("Paper.Origin", 6);
+            if (!originTag.isEmpty()) {
+                UUID originWorld = null;
+                if (nbt.contains("Paper.OriginWorld")) {
+                    originWorld = nbt.getUUID("Paper.OriginWorld");
+                } else if (this.level != null) {
+                    originWorld = this.level.getWorld().getUID();
+                }
+                this.originWorld = originWorld;
+                origin = new org.bukkit.util.Vector(originTag.getDouble(0), originTag.getDouble(1), originTag.getDouble(2));
+            }
+            // Paper end
+
         } catch (Throwable throwable) {
             CrashReport crashreport = CrashReport.forThrowable(throwable, "Loading entity NBT");
             CrashReportCategory crashreportsystemdetails = crashreport.addCategory("Entity being loaded");
diff --git a/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java b/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java
index 5d09790876c3c50d126678565001645f6aece16f..6c4224e4752b655710c5b992d9acf9563b183483 100644
--- a/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java
+++ b/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java
@@ -343,6 +343,14 @@ public class FallingBlockEntity extends Entity {
             this.blockState = Blocks.SAND.defaultBlockState();
         }
 
+        // Paper start - Try and load origin location from the old NBT tags for backwards compatibility
+        if (nbt.contains("SourceLoc_x")) {
+            int srcX = nbt.getInt("SourceLoc_x");
+            int srcY = nbt.getInt("SourceLoc_y");
+            int srcZ = nbt.getInt("SourceLoc_z");
+            this.setOrigin(new org.bukkit.Location(this.level().getWorld(), srcX, srcY, srcZ));
+        }
+        // Paper end
     }
 
     public void setHurtsEntities(float fallHurtAmount, int fallHurtMax) {
diff --git a/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java b/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
index f08c021f867c00611139a17db48352944eb2aa99..5c3b86e2301079e775971aa4da6a8f2dc6a40d1f 100644
--- a/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
+++ b/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
@@ -132,6 +132,14 @@ public class PrimedTnt extends Entity implements TraceableEntity {
             this.setBlockState(NbtUtils.readBlockState(this.level().holderLookup(Registries.BLOCK), nbt.getCompound("block_state")));
         }
 
+        // Paper start - Try and load origin location from the old NBT tags for backwards compatibility
+        if (nbt.contains("SourceLoc_x")) {
+            int srcX = nbt.getInt("SourceLoc_x");
+            int srcY = nbt.getInt("SourceLoc_y");
+            int srcZ = nbt.getInt("SourceLoc_z");
+            this.setOrigin(new org.bukkit.Location(this.level().getWorld(), srcX, srcY, srcZ));
+        }
+        // Paper end
     }
 
     @Nullable
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
index 9efb4615d6d196a658940a2211c73af46e1c54b5..beae7b8cf726f61b25c5afb553da8c34dce1dd37 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
@@ -1316,5 +1316,20 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
 
         return ret;
     }
+
+    @Override
+    public Location getOrigin() {
+        Vector originVector = this.getHandle().getOriginVector();
+        if (originVector == null) {
+            return null;
+        }
+        World world = this.getWorld();
+        if (this.getHandle().getOriginWorld() != null) {
+            world = org.bukkit.Bukkit.getWorld(this.getHandle().getOriginWorld());
+        }
+
+        //noinspection ConstantConditions
+        return originVector.toLocation(world);
+    }
     // Paper end
 }