Implemented Sharpness, Fire Aspect and Knockback enchantments

src/pocketmine/item/enchantment/Enchantment.php

@@ -117,6 +117,12 @@ class Enchantment{
 		self::registerEnchantment(new Enchantment(self::THORNS, "%enchantment.thorns", self::RARITY_MYTHIC, self::SLOT_TORSO, self::SLOT_HEAD | self::SLOT_LEGS | self::SLOT_FEET, 3));
 		self::registerEnchantment(new Enchantment(self::RESPIRATION, "%enchantment.oxygen", self::RARITY_RARE, self::SLOT_HEAD, self::SLOT_NONE, 3));
 
+		self::registerEnchantment(new SharpnessEnchantment(self::SHARPNESS, "%enchantment.damage.all", self::RARITY_COMMON, self::SLOT_SWORD, self::SLOT_AXE, 5));
+		//TODO: smite, bane of arthropods (these don't make sense now because their applicable mobs don't exist yet)
+
+		self::registerEnchantment(new KnockbackEnchantment(self::KNOCKBACK, "%enchantment.knockback", self::RARITY_UNCOMMON, self::SLOT_SWORD, self::SLOT_NONE, 2));
+		self::registerEnchantment(new FireAspectEnchantment(self::FIRE_ASPECT, "%enchantment.fire", self::RARITY_RARE, self::SLOT_SWORD, self::SLOT_NONE, 2));
+
 		self::registerEnchantment(new Enchantment(self::EFFICIENCY, "%enchantment.digging", self::RARITY_COMMON, self::SLOT_DIG, self::SLOT_SHEARS, 5));
 		self::registerEnchantment(new Enchantment(self::SILK_TOUCH, "%enchantment.untouching", self::RARITY_MYTHIC, self::SLOT_DIG, self::SLOT_SHEARS, 1));
 		self::registerEnchantment(new Enchantment(self::UNBREAKING, "%enchantment.durability", self::RARITY_UNCOMMON, self::SLOT_DIG | self::SLOT_ARMOR | self::SLOT_FISHING_ROD | self::SLOT_BOW, self::SLOT_TOOL | self::SLOT_CARROT_STICK | self::SLOT_ELYTRA, 3));

src/pocketmine/item/enchantment/FireAspectEnchantment.php

@@ -0,0 +1,41 @@
+<?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\item\enchantment;
+
+use pocketmine\entity\Entity;
+
+class FireAspectEnchantment extends MeleeWeaponEnchantment{
+
+	public function isApplicableTo(Entity $victim) : bool{
+		return true;
+	}
+
+	public function getDamageBonus(int $enchantmentLevel) : float{
+		return 0;
+	}
+
+	public function onPostAttack(Entity $attacker, Entity $victim, int $enchantmentLevel) : void{
+		$victim->setOnFire($enchantmentLevel * 4);
+	}
+}

src/pocketmine/item/enchantment/KnockbackEnchantment.php

@@ -0,0 +1,44 @@
+<?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\item\enchantment;
+
+use pocketmine\entity\Entity;
+use pocketmine\entity\Living;
+
+class KnockbackEnchantment extends MeleeWeaponEnchantment{
+
+	public function isApplicableTo(Entity $victim) : bool{
+		return $victim instanceof Living;
+	}
+
+	public function getDamageBonus(int $enchantmentLevel) : float{
+		return 0;
+	}
+
+	public function onPostAttack(Entity $attacker, Entity $victim, int $enchantmentLevel) : void{
+		if($victim instanceof Living){
+			$victim->knockBack($attacker, 0, $victim->x - $attacker->x, $victim->z - $attacker->z, $enchantmentLevel * 0.5);
+		}
+	}
+}

src/pocketmine/item/enchantment/MeleeWeaponEnchantment.php

@@ -0,0 +1,63 @@
+<?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\item\enchantment;
+
+use pocketmine\entity\Entity;
+
+/**
+ * Classes extending this class can be applied to weapons and activate when used by a mob to attack another mob in melee
+ * combat.
+ */
+abstract class MeleeWeaponEnchantment extends Enchantment{
+
+	/**
+	 * Returns whether this melee enchantment has an effect on the target entity. For example, Smite only applies to
+	 * undead mobs.
+	 *
+	 * @param Entity $victim
+	 *
+	 * @return bool
+	 */
+	abstract public function isApplicableTo(Entity $victim) : bool;
+
+	/**
+	 * Returns the amount of additional damage caused by this enchantment to applicable targets.
+	 *
+	 * @param int $enchantmentLevel
+	 *
+	 * @return float
+	 */
+	abstract public function getDamageBonus(int $enchantmentLevel) : float;
+
+	/**
+	 * Called after damaging the entity to apply any post damage effects to the target.
+	 *
+	 * @param Entity $attacker
+	 * @param Entity $victim
+	 * @param int    $enchantmentLevel
+	 */
+	public function onPostAttack(Entity $attacker, Entity $victim, int $enchantmentLevel) : void{
+
+	}
+}

src/pocketmine/item/enchantment/SharpnessEnchantment.php

@@ -0,0 +1,37 @@
+<?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\item\enchantment;
+
+use pocketmine\entity\Entity;
+
+class SharpnessEnchantment extends MeleeWeaponEnchantment{
+
+	public function isApplicableTo(Entity $victim) : bool{
+		return true;
+	}
+
+	public function getDamageBonus(int $enchantmentLevel) : float{
+		return 0.5 * ($enchantmentLevel + 1);
+	}
+}