From 97c267c70cc2e5df25a147482b36e8825250b4c6 Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Sat, 23 Jun 2018 17:40:01 +0100
Subject: [PATCH] Implemented Punch enchantment

---
 src/pocketmine/entity/projectile/Arrow.php    | 28 +++++++++++++++++++
 src/pocketmine/item/Bow.php                   |  9 ++++--
 .../item/enchantment/Enchantment.php          |  2 +-
 3 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/src/pocketmine/entity/projectile/Arrow.php b/src/pocketmine/entity/projectile/Arrow.php
index 5842149a96..3db4e26a50 100644
--- a/src/pocketmine/entity/projectile/Arrow.php
+++ b/src/pocketmine/entity/projectile/Arrow.php
@@ -31,6 +31,7 @@ use pocketmine\item\Item;
 use pocketmine\item\ItemFactory;
 use pocketmine\level\Level;
 use pocketmine\math\RayTraceResult;
+use pocketmine\math\Vector3;
 use pocketmine\nbt\tag\CompoundTag;
 use pocketmine\network\mcpe\protocol\EntityEventPacket;
 use pocketmine\network\mcpe\protocol\LevelSoundEventPacket;
@@ -58,6 +59,9 @@ class Arrow extends Projectile{
 	/** @var int */
 	protected $pickupMode = self::PICKUP_ANY;
 
+	/** @var float */
+	protected $punchKnockback = 0.0;
+
 	public function __construct(Level $level, CompoundTag $nbt, ?Entity $shootingEntity = null, bool $critical = false){
 		parent::__construct($level, $nbt, $shootingEntity);
 		$this->setCritical($critical);
@@ -92,6 +96,20 @@ class Arrow extends Projectile{
 		}
 	}
 
+	/**
+	 * @return float
+	 */
+	public function getPunchKnockback() : float{
+		return $this->punchKnockback;
+	}
+
+	/**
+	 * @param float $punchKnockback
+	 */
+	public function setPunchKnockback(float $punchKnockback) : void{
+		$this->punchKnockback = $punchKnockback;
+	}
+
 	public function entityBaseTick(int $tickDiff = 1) : bool{
 		if($this->closed){
 			return false;
@@ -117,6 +135,16 @@ class Arrow extends Projectile{
 		$this->broadcastEntityEvent(EntityEventPacket::ARROW_SHAKE, 7); //7 ticks
 	}
 
+	protected function onHitEntity(Entity $entityHit, RayTraceResult $hitResult) : void{
+		parent::onHitEntity($entityHit, $hitResult);
+		if($this->punchKnockback > 0){
+			$mot = $entityHit->getMotion();
+			$multiplier = $this->punchKnockback * 0.6 / $mot->length();
+
+			$entityHit->setMotion($mot->add($mot->x * $multiplier, 0.1, $mot->z * $multiplier));
+		}
+	}
+
 	/**
 	 * @return int
 	 */
diff --git a/src/pocketmine/item/Bow.php b/src/pocketmine/item/Bow.php
index fb0c382043..3e785c71d7 100644
--- a/src/pocketmine/item/Bow.php
+++ b/src/pocketmine/item/Bow.php
@@ -67,8 +67,13 @@ class Bow extends Tool{
 		$entity = Entity::createEntity("Arrow", $player->getLevel(), $nbt, $player, $force == 2);
 		if($entity instanceof Projectile){
 			$infinity = $this->hasEnchantment(Enchantment::INFINITY);
-			if($infinity and $entity instanceof ArrowEntity){
-				$entity->setPickupMode(ArrowEntity::PICKUP_CREATIVE);
+			if($entity instanceof ArrowEntity){
+				if($infinity){
+					$entity->setPickupMode(ArrowEntity::PICKUP_CREATIVE);
+				}
+				if(($punchLevel = $this->getEnchantmentLevel(Enchantment::PUNCH)) > 0){
+					$entity->setPunchKnockback($punchLevel);
+				}
 			}
 			if(($powerLevel = $this->getEnchantmentLevel(Enchantment::POWER)) > 0){
 				$entity->setBaseDamage($entity->getBaseDamage() + (($powerLevel + 1) / 2));
diff --git a/src/pocketmine/item/enchantment/Enchantment.php b/src/pocketmine/item/enchantment/Enchantment.php
index f92937a79f..9b4e7f461f 100644
--- a/src/pocketmine/item/enchantment/Enchantment.php
+++ b/src/pocketmine/item/enchantment/Enchantment.php
@@ -122,7 +122,7 @@ class Enchantment{
 		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));
 
 		self::registerEnchantment(new Enchantment(self::POWER, "%enchantment.arrowDamage", self::RARITY_COMMON, self::SLOT_BOW, self::SLOT_NONE, 5));
-
+		self::registerEnchantment(new Enchantment(self::PUNCH, "%enchantment.arrowKnockback", self::RARITY_RARE, self::SLOT_BOW, self::SLOT_NONE, 2));
 		self::registerEnchantment(new Enchantment(self::FLAME, "%enchantment.arrowFire", self::RARITY_RARE, self::SLOT_BOW, self::SLOT_NONE, 1));
 		self::registerEnchantment(new Enchantment(self::INFINITY, "%enchantment.arrowInfinite", self::RARITY_MYTHIC, self::SLOT_BOW, self::SLOT_NONE, 1));