New skin API, add support for custom capes & custom geometry (#1416)

* Added support for changing skins ingame, custom capes & geometry
* Use PlayerSkinPacket for setting Human skin instead of PlayerList hack

src/pocketmine/entity/Skin.php

@@ -0,0 +1,90 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+declare(strict_types=1);
+
+namespace pocketmine\entity;
+
+class Skin{
+
+	/** @var string */
+	private $skinId;
+	/** @var string */
+	private $skinData;
+	/** @var string */
+	private $capeData;
+	/** @var string */
+	private $geometryName;
+	/** @var string */
+	private $geometryData;
+
+	public function __construct(string $skinId, string $skinData, string $capeData = "", string $geometryName = "", string $geometryData = ""){
+		$this->skinId = $skinId;
+		$this->skinData = $skinData;
+		$this->capeData = $capeData;
+		$this->geometryName = $geometryName;
+		$this->geometryData = $geometryData;
+	}
+
+	public function isValid() : bool{
+		return (
+			$this->skinId !== "" and
+			(($s = strlen($this->skinData)) === 16384 or $s === 8192) and
+			($this->capeData === "" or strlen($this->capeData) === 8192)
+		);
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getSkinId() : string{
+		return $this->skinId;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getSkinData() : string{
+		return $this->skinData;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getCapeData() : string{
+		return $this->capeData;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getGeometryName() : string{
+		return $this->geometryName;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getGeometryData() : string{
+		return $this->geometryData;
+	}
+
+}