Chunk: move protocol-specific getSubChunkSendCount() to network chunk serializer

src/network/mcpe/ChunkRequestTask.php

@@ -61,7 +61,7 @@ class ChunkRequestTask extends AsyncTask{
 
 	public function onRun() : void{
 		$chunk = FastChunkSerializer::deserialize($this->chunk);
-		$subCount = $chunk->getSubChunkSendCount();
+		$subCount = ChunkSerializer::getSubChunkCount($chunk);
 		$payload = ChunkSerializer::serialize($chunk, $this->tiles);
 		$this->setResult(Zlib::compress(PacketBatch::fromPackets(LevelChunkPacket::withoutCache($this->chunkX, $this->chunkZ, $subCount, $payload))->getBuffer(), $this->compressionLevel));
 	}

src/network/mcpe/serializer/ChunkSerializer.php

@@ -35,6 +35,24 @@ final class ChunkSerializer{
 		//NOOP
 	}
 
+	/**
+	 * Returns the number of subchunks that will be sent from the given chunk.
+	 * Chunks are sent in a stack, so every chunk below the top non-empty one must be sent.
+	 * @param Chunk $chunk
+	 *
+	 * @return int
+	 */
+	public static function getSubChunkCount(Chunk $chunk) : int{
+		for($count = $chunk->getSubChunks()->count(); $count > 0; --$count){
+			if($chunk->getSubChunk($count - 1)->isEmptyFast()){
+				continue;
+			}
+			break;
+		}
+
+		return $count;
+	}
+
 	/**
 	 * @param Chunk       $chunk
 	 *
@@ -44,7 +62,7 @@ final class ChunkSerializer{
 	 */
 	public static function serialize(Chunk $chunk, ?string $tiles = null) : string{
 		$stream = new NetworkBinaryStream();
-		$subChunkCount = $chunk->getSubChunkSendCount();
+		$subChunkCount = self::getSubChunkCount($chunk);
 		for($y = 0; $y < $subChunkCount; ++$y){
 			$layers = $chunk->getSubChunk($y)->getBlockLayers();
 			$stream->putByte(8); //version

src/world/format/Chunk.php

@@ -682,22 +682,6 @@ class Chunk{
 		return $this->subChunks;
 	}
 
-	/**
-	 * Returns the count of subchunks that need sending to players
-	 *
-	 * @return int
-	 */
-	public function getSubChunkSendCount() : int{
-		for($count = $this->subChunks->count(); $count > 0; --$count){
-			if($this->subChunks[$count - 1]->isEmptyFast()){
-				continue;
-			}
-			break;
-		}
-
-		return $count;
-	}
-
 	/**
 	 * Disposes of empty subchunks and frees data where possible
 	 */