From c51c8ae700e82722d617e6d3c820ffd765051c10 Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Wed, 10 May 2017 10:48:53 +0100
Subject: [PATCH] Standardised attributes encoding

---
 .../network/mcpe/protocol/AddEntityPacket.php |  8 +--
 .../network/mcpe/protocol/DataPacket.php      | 49 +++++++++++++++++++
 .../mcpe/protocol/UpdateAttributesPacket.php  | 10 +---
 3 files changed, 51 insertions(+), 16 deletions(-)

diff --git a/src/pocketmine/network/mcpe/protocol/AddEntityPacket.php b/src/pocketmine/network/mcpe/protocol/AddEntityPacket.php
index 09c47f7ba..b3e0c63c0 100644
--- a/src/pocketmine/network/mcpe/protocol/AddEntityPacket.php
+++ b/src/pocketmine/network/mcpe/protocol/AddEntityPacket.php
@@ -57,13 +57,7 @@ class AddEntityPacket extends DataPacket{
 		$this->putVector3f($this->speedX, $this->speedY, $this->speedZ);
 		$this->putLFloat($this->pitch);
 		$this->putLFloat($this->yaw);
-		$this->putUnsignedVarInt(count($this->attributes));
-		foreach($this->attributes as $entry){
-			$this->putString($entry->getName());
-			$this->putLFloat($entry->getMinValue());
-			$this->putLFloat($entry->getValue());
-			$this->putLFloat($entry->getMaxValue());
-		}
+		$this->putAttributeList(...$this->attributes);
 		$this->putEntityMetadata($this->metadata);
 		$this->putUnsignedVarInt(count($this->links));
 		foreach($this->links as $link){
diff --git a/src/pocketmine/network/mcpe/protocol/DataPacket.php b/src/pocketmine/network/mcpe/protocol/DataPacket.php
index f530eb179..a41a83aaf 100644
--- a/src/pocketmine/network/mcpe/protocol/DataPacket.php
+++ b/src/pocketmine/network/mcpe/protocol/DataPacket.php
@@ -23,6 +23,7 @@ namespace pocketmine\network\mcpe\protocol;
 
 #include <rules/DataPacket.h>
 
+use pocketmine\entity\Attribute;
 use pocketmine\entity\Entity;
 use pocketmine\item\Item;
 use pocketmine\network\mcpe\NetworkSession;
@@ -201,6 +202,54 @@ abstract class DataPacket extends BinaryStream{
 		}
 	}
 
+	/**
+	 * Reads a list of Attributes from the stream.
+	 * @return Attribute[]
+	 *
+	 * @throws \UnexpectedValueException if reading an attribute with an unrecognized name
+	 */
+	public function getAttributeList() : array{
+		$list = [];
+		$count = $this->getUnsignedVarInt();
+
+		for($i = 0; $i < $count; ++$i){
+			$min = $this->getLFloat();
+			$max = $this->getLFloat();
+			$current = $this->getLFloat();
+			$default = $this->getLFloat();
+			$name = $this->getString();
+
+			$attr = Attribute::getAttributeByName($name);
+			if($attr !== null){
+				$attr->setMinValue($min);
+				$attr->setMaxValue($max);
+				$attr->setValue($current);
+				$attr->setDefaultValue($default);
+
+				$list[] = $attr;
+			}else{
+				throw new \UnexpectedValueException("Unknown attribute type \"$name\"");
+			}
+		}
+
+		return $list;
+	}
+
+	/**
+	 * Writes a list of Attributes to the packet buffer using the standard format.
+	 * @param Attribute[] ...$attributes
+	 */
+	public function putAttributeList(Attribute ...$attributes){
+		$this->putUnsignedVarInt(count($attributes));
+		foreach($attributes as $attribute){
+			$this->putLFloat($attribute->getMinValue());
+			$this->putLFloat($attribute->getMaxValue());
+			$this->putLFloat($attribute->getValue());
+			$this->putLFloat($attribute->getDefaultValue());
+			$this->putString($attribute->getName());
+		}
+	}
+
 	/**
 	 * Reads and returns an EntityUniqueID
 	 * @return int|string
diff --git a/src/pocketmine/network/mcpe/protocol/UpdateAttributesPacket.php b/src/pocketmine/network/mcpe/protocol/UpdateAttributesPacket.php
index 9f369579f..68cd90e72 100644
--- a/src/pocketmine/network/mcpe/protocol/UpdateAttributesPacket.php
+++ b/src/pocketmine/network/mcpe/protocol/UpdateAttributesPacket.php
@@ -30,7 +30,6 @@ use pocketmine\network\mcpe\NetworkSession;
 class UpdateAttributesPacket extends DataPacket{
 	const NETWORK_ID = ProtocolInfo::UPDATE_ATTRIBUTES_PACKET;
 
-
 	public $entityId;
 	/** @var Attribute[] */
 	public $entries = [];
@@ -42,14 +41,7 @@ class UpdateAttributesPacket extends DataPacket{
 	public function encode(){
 		$this->reset();
 		$this->putEntityRuntimeId($this->entityId);
-		$this->putUnsignedVarInt(count($this->entries));
-		foreach($this->entries as $entry){
-			$this->putLFloat($entry->getMinValue());
-			$this->putLFloat($entry->getMaxValue());
-			$this->putLFloat($entry->getValue());
-			$this->putLFloat($entry->getDefaultValue());
-			$this->putString($entry->getName());
-		}
+		$this->putAttributeList(...$this->entries);
 	}
 
 	public function handle(NetworkSession $session) : bool{