Implement crawling

src/entity/Living.php

@@ -124,6 +124,7 @@ abstract class Living extends Entity{
 	protected bool $sneaking = false;
 	protected bool $gliding = false;
 	protected bool $swimming = false;
+	protected bool $crawling = false;
 
 	protected function getInitialDragMultiplier() : float{ return 0.02; }
 
@@ -268,11 +269,21 @@ public function setSwimming(bool $value = true) : void{
 		$this->recalculateSize();
 	}
 
+	public function isCrawling() : bool{
+		return $this->crawling;
+	}
+
+	public function setCrawling(bool $value = true) : void{
+		$this->crawling = $value;
+		$this->networkPropertiesDirty = true;
+		$this->recalculateSize();
+	}
+
 	private function recalculateSize() : void{
 		$size = $this->getInitialSizeInfo();
-		if($this->isSwimming() || $this->isGliding()){
+		if($this->isSwimming() || $this->isGliding() || $this->isCrawling()){
 			$width = $size->getWidth();
-			$this->setSize((new EntitySizeInfo($width, $width, $width * 0.9))->scale($this->getScale()));
+			$this->setSize((new EntitySizeInfo(5 / 8, $width, 5 / 8 * 0.9))->scale($this->getScale()));
 		}elseif($this->isSneaking()){
 			$this->setSize((new EntitySizeInfo(3 / 4 * $size->getHeight(), $size->getWidth(), 3 / 4 * $size->getEyeHeight()))->scale($this->getScale()));
 		}else{
@@ -894,6 +905,7 @@ protected function syncNetworkData(EntityMetadataCollection $properties) : void{
 		$properties->setGenericFlag(EntityMetadataFlags::SPRINTING, $this->sprinting);
 		$properties->setGenericFlag(EntityMetadataFlags::GLIDING, $this->gliding);
 		$properties->setGenericFlag(EntityMetadataFlags::SWIMMING, $this->swimming);
+		$properties->setGenericFlag(EntityMetadataFlags::CRAWLING, $this->crawling);
 	}
 
 	protected function onDispose() : void{

src/event/player/PlayerToggleCrawlEvent.php

@@ -0,0 +1,40 @@
+<?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\event\player;
+
+use pocketmine\event\Cancellable;
+use pocketmine\event\CancellableTrait;
+use pocketmine\player\Player;
+
+class PlayerToggleCrawlEvent extends PlayerEvent implements Cancellable{
+	use CancellableTrait;
+
+	public function __construct(Player $player, protected bool $isCrawling){
+		$this->player = $player;
+	}
+
+	public function isCrawling() : bool{
+		return $this->isCrawling;
+	}
+}

src/player/Player.php

@@ -72,6 +72,7 @@
 use pocketmine\event\player\PlayerPostChunkSendEvent;
 use pocketmine\event\player\PlayerQuitEvent;
 use pocketmine\event\player\PlayerRespawnEvent;
+use pocketmine\event\player\PlayerToggleCrawlEvent;
 use pocketmine\event\player\PlayerToggleFlightEvent;
 use pocketmine\event\player\PlayerToggleGlideEvent;
 use pocketmine\event\player\PlayerToggleSneakEvent;
@@ -1994,10 +1995,6 @@ public function toggleFlight(bool $fly) : bool{
 		return true;
 	}
 
-	public function toggleCrawl(bool $crawl) : bool{
-		return false;
-	}
-
 	public function toggleGlide(bool $glide) : bool{
 		if($glide === $this->gliding){
 			return true;
@@ -2024,6 +2021,19 @@ public function toggleSwim(bool $swim) : bool{
 		return true;
 	}
 
+	public function toggleCrawl(bool $crawl) : bool{
+		if($crawl === $this->crawling){
+			return true;
+		}
+		$ev = new PlayerToggleCrawlEvent($this, $crawl);
+		$ev->call();
+		if($ev->isCancelled()){
+			return false;
+		}
+		$this->setCrawling($crawl);
+		return true;
+	}
+
 	public function emote(string $emoteId) : void{
 		$currentTick = $this->server->getTick();
 		if($currentTick - $this->lastEmoteTick > 5){