Implement cauldrons (#5163)

the following things are currently not implemented:

- particle/sound effects when an entity extinguishes itself
- particle/sound effects when mixing different stuff in a cauldron
- powder snow cauldron

both of these things are contingent on #5169, but for the time being, the PR is functionally complete and I want to move on to something else without being stalled by the particle+sound problem (which I haven't yet decided how to solve).

src/block/PotionCauldron.php

@@ -0,0 +1,108 @@
+<?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\block;
+
+use pocketmine\block\tile\Cauldron as TileCauldron;
+use pocketmine\item\Item;
+use pocketmine\item\ItemTypeIds;
+use pocketmine\item\VanillaItems;
+use pocketmine\math\Vector3;
+use pocketmine\player\Player;
+use pocketmine\world\sound\CauldronEmptyPotionSound;
+use pocketmine\world\sound\CauldronFillPotionSound;
+use pocketmine\world\sound\Sound;
+use function assert;
+
+final class PotionCauldron extends FillableCauldron{
+	public const POTION_FILL_AMOUNT = 2;
+
+	private ?Item $potionItem = null;
+
+	public function __construct(BlockIdentifier $idInfo, string $name, BlockBreakInfo $breakInfo){
+		parent::__construct($idInfo, $name, $breakInfo);
+	}
+
+	public function readStateFromWorld() : Block{
+		parent::readStateFromWorld();
+		$tile = $this->position->getWorld()->getTile($this->position);
+		$this->potionItem = $tile instanceof TileCauldron ? $tile->getPotionItem() : null;
+
+		return $this;
+	}
+
+	public function writeStateToWorld() : void{
+		parent::writeStateToWorld();
+		$tile = $this->position->getWorld()->getTile($this->position);
+		assert($tile instanceof TileCauldron);
+		$tile->setCustomWaterColor(null);
+		$tile->setPotionItem($this->potionItem);
+	}
+
+	public function getPotionItem() : ?Item{ return $this->potionItem === null ? null : clone $this->potionItem; }
+
+	/** @return $this */
+	public function setPotionItem(?Item $potionItem) : self{
+		$this->potionItem = $potionItem !== null ? (clone $potionItem)->setCount(1) : null;
+		return $this;
+	}
+
+	public function getFillSound() : Sound{
+		return new CauldronFillPotionSound();
+	}
+
+	public function getEmptySound() : Sound{
+		return new CauldronEmptyPotionSound();
+	}
+
+	/**
+	 * @param Item[] &$returnedItems
+	 */
+	protected function addFillLevelsOrMix(int $amount, Item $usedItem, Item $returnedItem, array &$returnedItems) : void{
+		if($this->potionItem !== null && !$usedItem->equals($this->potionItem, true, false)){
+			$this->mix($usedItem, $returnedItem, $returnedItems);
+		}else{
+			$this->addFillLevels($amount, $usedItem, $returnedItem, $returnedItems);
+		}
+	}
+
+	public function onInteract(Item $item, int $face, Vector3 $clickVector, ?Player $player = null, array &$returnedItems = []) : bool{
+		match($item->getTypeId()){
+			ItemTypeIds::LINGERING_POTION, ItemTypeIds::POTION, ItemTypeIds::SPLASH_POTION => $this->addFillLevelsOrMix(self::POTION_FILL_AMOUNT, $item, VanillaItems::GLASS_BOTTLE(), $returnedItems),
+			ItemTypeIds::GLASS_BOTTLE => $this->potionItem === null ? null : $this->removeFillLevels(self::POTION_FILL_AMOUNT, $item, clone $this->potionItem, $returnedItems),
+			ItemTypeIds::LAVA_BUCKET, ItemTypeIds::POWDER_SNOW_BUCKET, ItemTypeIds::WATER_BUCKET => $this->mix($item, VanillaItems::BUCKET(), $returnedItems),
+			//TODO: tipped arrows
+			default => null
+		};
+		return true;
+	}
+
+	public function onNearbyBlockChange() : void{
+		$world = $this->position->getWorld();
+		if($world->getBlock($this->position->up())->getTypeId() === BlockTypeIds::WATER){
+			$cauldron = VanillaBlocks::WATER_CAULDRON()->setFillLevel(FillableCauldron::MAX_FILL_LEVEL);
+			$world->setBlock($this->position, $cauldron);
+			$world->addSound($this->position->add(0.5, 0.5, 0.5), $cauldron->getFillSound());
+		}
+	}
+}