Tile: Removed cyclic dependence on Chunks

Chunks were used by tiles for a couple of things:
- 1. for coordinates - which can be gotten using bitshifts
- 2. setChanged() - which is unnecessary as seen in the previous commit

Removing this circular dependency was actually remarkably easy to do.

src/pocketmine/level/Level.php

@@ -2388,7 +2388,6 @@ class Level implements ChunkManager, Metadatable{
 			foreach($oldTiles as $tile){
 				$chunk->addTile($tile);
 				$oldChunk->removeTile($tile);
-				$tile->chunk = $chunk;
 			}
 		}
 
@@ -2600,8 +2599,18 @@ class Level implements ChunkManager, Metadatable{
 		if($tile->getLevel() !== $this){
 			throw new LevelException("Invalid Tile level");
 		}
+
+		$chunkX = $tile->getFloorX() >> 4;
+		$chunkZ = $tile->getFloorZ() >> 4;
+
+		if(isset($this->chunks[$hash = Level::chunkHash($chunkX, $chunkZ)])){
+			$this->chunks[$hash]->addTile($tile);
+		}else{
+			throw new \InvalidStateException("Attempted to create tile " . get_class($tile) . " in unloaded chunk $chunkX $chunkZ");
+		}
+
 		$this->tiles[$tile->getId()] = $tile;
-		$this->clearChunkCache($tile->getFloorX() >> 4, $tile->getFloorZ() >> 4);
+		$this->clearChunkCache($chunkX, $chunkZ);
 	}
 
 	/**
@@ -2614,9 +2623,15 @@ class Level implements ChunkManager, Metadatable{
 			throw new LevelException("Invalid Tile level");
 		}
 
-		unset($this->tiles[$tile->getId()]);
+		unset($this->tiles[$tile->getId()], $this->updateTiles[$tile->getId()]);
-		unset($this->updateTiles[$tile->getId()]);
+
-		$this->clearChunkCache($tile->getFloorX() >> 4, $tile->getFloorZ() >> 4);
+		$chunkX = $tile->getFloorX() >> 4;
+		$chunkZ = $tile->getFloorZ() >> 4;
+
+		if(isset($this->chunks[$hash = Level::chunkHash($chunkX, $chunkZ)])){
+			$this->chunks[$hash]->removeTile($tile);
+		}
+		$this->clearChunkCache($chunkX, $chunkZ);
 	}
 
 	/**

src/pocketmine/tile/Spawnable.php

@@ -67,7 +67,7 @@ abstract class Spawnable extends Tile{
 		}
 
 		$pk = $this->createSpawnPacket();
-		$this->level->addChunkPacket($this->chunk->getX(), $this->chunk->getZ(), $pk);
+		$this->level->addChunkPacket($this->getFloorX() >> 4, $this->getFloorZ() >> 4, $pk);
 	}
 
 	/**
@@ -78,9 +78,7 @@ abstract class Spawnable extends Tile{
 		$this->spawnCompoundCache = null;
 		$this->spawnToAll();
 
-		if($this->chunk !== null){
+		$this->level->clearChunkCache($this->getFloorX() >> 4, $this->getFloorZ() >> 4);
-			$this->level->clearChunkCache($this->chunk->getX(), $this->chunk->getZ());
-		}
 	}
 
 	/**

src/pocketmine/tile/Tile.php

@@ -31,7 +31,6 @@ use pocketmine\block\Block;
 use pocketmine\event\Timings;
 use pocketmine\event\TimingsHandler;
 use pocketmine\item\Item;
-use pocketmine\level\format\Chunk;
 use pocketmine\level\Level;
 use pocketmine\level\Position;
 use pocketmine\math\Vector3;
@@ -69,8 +68,6 @@ abstract class Tile extends Position{
 	/** @var string[][] */
 	private static $saveNames = [];
 
-	/** @var Chunk */
-	public $chunk;
 	/** @var string */
 	public $name;
 	/** @var int */
@@ -161,10 +158,6 @@ abstract class Tile extends Position{
 		$this->namedtag = $nbt;
 		$this->server = $level->getServer();
 		$this->setLevel($level);
-		$this->chunk = $level->getChunk($this->namedtag->getInt(self::TAG_X) >> 4, $this->namedtag->getInt(self::TAG_Z) >> 4, false);
-		if($this->chunk === null){
-			throw new \InvalidStateException("Cannot create tiles in unloaded chunks");
-		}
 
 		$this->name = "";
 		$this->id = Tile::$tileCount++;
@@ -172,7 +165,6 @@ abstract class Tile extends Position{
 		$this->y = $this->namedtag->getInt(self::TAG_Y);
 		$this->z = $this->namedtag->getInt(self::TAG_Z);
 
-		$this->chunk->addTile($this);
 		$this->getLevel()->addTile($this);
 	}
 
@@ -276,11 +268,7 @@ abstract class Tile extends Position{
 	public function close() : void{
 		if(!$this->closed){
 			$this->closed = true;
-			unset($this->level->updateTiles[$this->id]);
+
-			if($this->chunk instanceof Chunk){
-				$this->chunk->removeTile($this);
-				$this->chunk = null;
-			}
 			if(($level = $this->getLevel()) instanceof Level){
 				$level->removeTile($this);
 				$this->setLevel(null);