Block::readStateFromWorld() now returns the block object that should be used for the target position

this enables changing the block type completely if the situation calls for it.

src/block/BaseBanner.php

@@ -53,13 +53,15 @@ abstract class BaseBanner extends Transparent{
 		parent::__construct($idInfo, $name, $breakInfo);
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		$tile = $this->position->getWorld()->getTile($this->position);
 		if($tile instanceof TileBanner){
 			$this->color = $tile->getBaseColor();
 			$this->setPatterns($tile->getPatterns());
 		}
+
+		return $this;
 	}
 
 	public function writeStateToWorld() : void{

src/block/BaseSign.php

@@ -58,13 +58,15 @@ abstract class BaseSign extends Transparent{
 		$this->asItemCallback = $asItemCallback;
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		$tile = $this->position->getWorld()->getTile($this->position);
 		if($tile instanceof TileSign){
 			$this->text = $tile->getText();
 			$this->editorEntityRuntimeId = $tile->getEditorEntityRuntimeId();
 		}
+
+		return $this;
 	}
 
 	public function writeStateToWorld() : void{

src/block/Bed.php

@@ -68,13 +68,15 @@ class Bed extends Transparent{
 		$w->writeBool($this->head);
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		//read extra state information from the tile - this is an ugly hack
 		$tile = $this->position->getWorld()->getTile($this->position);
 		if($tile instanceof TileBed){
 			$this->color = $tile->getColor();
 		}
+
+		return $this;
 	}
 
 	public function writeStateToWorld() : void{

src/block/Block.php

@@ -189,9 +189,14 @@ class Block{
 	 *
 	 * Clears any cached precomputed objects, such as bounding boxes. Remove any outdated precomputed things such as
 	 * AABBs and force recalculation.
+	 *
+	 * A replacement block may be returned. This is useful if the block type changed due to reading of world data (e.g.
+	 * data from a block entity).
 	 */
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		$this->collisionBoxes = null;
+
+		return $this;
 	}
 
 	public function writeStateToWorld() : void{

src/block/Door.php

@@ -58,7 +58,7 @@ class Door extends Transparent{
 		$w->writeBool($this->open);
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 
 		//copy door properties from other half
@@ -71,6 +71,8 @@ class Door extends Transparent{
 				$this->hingeRight = $other->hingeRight;
 			}
 		}
+
+		return $this;
 	}
 
 	public function isTop() : bool{ return $this->top; }

src/block/Fence.php

@@ -37,7 +37,7 @@ class Fence extends Transparent{
 		return 0.25;
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 
 		foreach(Facing::HORIZONTAL as $facing){
@@ -48,6 +48,8 @@ class Fence extends Transparent{
 				unset($this->connections[$facing]);
 			}
 		}
+
+		return $this;
 	}
 
 	/**

src/block/FlowerPot.php

@@ -36,7 +36,7 @@ class FlowerPot extends Flowable{
 
 	protected ?Block $plant = null;
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		$tile = $this->position->getWorld()->getTile($this->position);
 		if($tile instanceof TileFlowerPot){
@@ -44,6 +44,8 @@ class FlowerPot extends Flowable{
 		}else{
 			$this->setPlant(null);
 		}
+
+		return $this;
 	}
 
 	public function writeStateToWorld() : void{

src/block/ItemFrame.php

@@ -71,7 +71,7 @@ class ItemFrame extends Flowable{
 		$w->writeBool($this->hasMap);
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		$tile = $this->position->getWorld()->getTile($this->position);
 		if($tile instanceof TileItemFrame){
@@ -82,6 +82,8 @@ class ItemFrame extends Flowable{
 			$this->itemRotation = $tile->getItemRotation() % self::ROTATIONS;
 			$this->itemDropChance = $tile->getItemDropChance();
 		}
+
+		return $this;
 	}
 
 	public function writeStateToWorld() : void{

src/block/Jukebox.php

@@ -96,12 +96,14 @@ class Jukebox extends Opaque{
 		return $drops;
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		$jukebox = $this->position->getWorld()->getTile($this->position);
 		if($jukebox instanceof JukeboxTile){
 			$this->record = $jukebox->getRecord();
 		}
+
+		return $this;
 	}
 
 	public function writeStateToWorld() : void{

src/block/Lectern.php

@@ -59,13 +59,15 @@ class Lectern extends Transparent{
 		$w->writeBool($this->producingSignal);
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		$tile = $this->position->getWorld()->getTile($this->position);
 		if($tile instanceof TileLectern){
 			$this->viewedPage = $tile->getViewedPage();
 			$this->book = $tile->getBook();
 		}
+
+		return $this;
 	}
 
 	public function writeStateToWorld() : void{

src/block/Liquid.php

@@ -160,9 +160,11 @@ abstract class Liquid extends Transparent{
 		return $block->falling ? 0 : $block->decay;
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		$this->flowVector = null;
+
+		return $this;
 	}
 
 	public function getFlowVector() : Vector3{

src/block/Note.php

@@ -32,7 +32,7 @@ class Note extends Opaque{
 
 	private int $pitch = self::MIN_PITCH;
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		$tile = $this->position->getWorld()->getTile($this->position);
 		if($tile instanceof TileNote){
@@ -40,6 +40,8 @@ class Note extends Opaque{
 		}else{
 			$this->pitch = self::MIN_PITCH;
 		}
+
+		return $this;
 	}
 
 	public function writeStateToWorld() : void{

src/block/RedstoneComparator.php

@@ -60,12 +60,14 @@ class RedstoneComparator extends Flowable{
 		$w->writeBool($this->powered);
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		$tile = $this->position->getWorld()->getTile($this->position);
 		if($tile instanceof Comparator){
 			$this->signalStrength = $tile->getSignalStrength();
 		}
+
+		return $this;
 	}
 
 	public function writeStateToWorld() : void{

src/block/RedstoneWire.php

@@ -41,9 +41,11 @@ class RedstoneWire extends Flowable{
 		return false;
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		//TODO: check connections to nearby redstone components
+
+		return $this;
 	}
 
 	public function onNearbyBlockChange() : void{

src/block/ShulkerBox.php

@@ -53,12 +53,14 @@ class ShulkerBox extends Opaque{
 		}
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		$shulker = $this->position->getWorld()->getTile($this->position);
 		if($shulker instanceof TileShulkerBox){
 			$this->facing = $shulker->getFacing();
 		}
+
+		return $this;
 	}
 
 	public function getMaxStackSize() : int{

src/block/Skull.php

@@ -77,13 +77,15 @@ class Skull extends Flowable{
 		$w->writeFacing($this->facing);
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 		$tile = $this->position->getWorld()->getTile($this->position);
 		if($tile instanceof TileSkull){
 			$this->skullType = $tile->getSkullType();
 			$this->rotation = $tile->getRotation();
 		}
+
+		return $this;
 	}
 
 	public function writeStateToWorld() : void{

src/block/Stair.php

@@ -59,7 +59,7 @@ class Stair extends Transparent{
 		$w->writeBool($this->upsideDown);
 	}
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 
 		$clockwise = Facing::rotateY($this->facing, true);
@@ -70,6 +70,8 @@ class Stair extends Transparent{
 		}else{
 			$this->shape = StairShape::STRAIGHT();
 		}
+
+		return $this;
 	}
 
 	public function isUpsideDown() : bool{ return $this->upsideDown; }

src/block/Thin.php

@@ -33,7 +33,7 @@ class Thin extends Transparent{
 	/** @var bool[] facing => dummy */
 	protected array $connections = [];
 
-	public function readStateFromWorld() : void{
+	public function readStateFromWorld() : Block{
 		parent::readStateFromWorld();
 
 		foreach(Facing::HORIZONTAL as $facing){
@@ -44,6 +44,8 @@ class Thin extends Transparent{
 				unset($this->connections[$facing]);
 			}
 		}
+
+		return $this;
 	}
 
 	protected function recalculateCollisionBoxes() : array{

src/world/World.php

@@ -824,7 +824,11 @@ class World implements ChunkManager{
 			}
 
 			$block = $this->getBlockAt($x, $y, $z);
-			$block->readStateFromWorld(); //for blocks like fences, force recalculation of connected AABBs
+			$replacement = $block->readStateFromWorld(); //for blocks like fences, force recalculation of connected AABBs
+			if($replacement !== $block){
+				$replacement->position($this, $x, $y, $z);
+				$block = $replacement;
+			}
 
 			$ev = new BlockUpdateEvent($block);
 			$ev->call();
@@ -1548,7 +1552,11 @@ class World implements ChunkManager{
 			$addToCache = false;
 		}else{
 			$dynamicStateRead = true;
-			$block->readStateFromWorld();
+			$replacement = $block->readStateFromWorld();
+			if($replacement !== $block){
+				$replacement->position($this, $x, $y, $z);
+				$block = $replacement;
+			}
 			$dynamicStateRead = false;
 		}