Living.php

<?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;
 
use pocketmine\block\Block;
use pocketmine\block\BlockTypeIds;
use pocketmine\block\VanillaBlocks;
use pocketmine\block\Water;
use pocketmine\data\bedrock\EffectIdMap;
use pocketmine\entity\animation\DeathAnimation;
use pocketmine\entity\animation\HurtAnimation;
use pocketmine\entity\animation\RespawnAnimation;
use pocketmine\entity\effect\EffectInstance;
use pocketmine\entity\effect\EffectManager;
use pocketmine\entity\effect\VanillaEffects;
use pocketmine\event\entity\EntityDamageByChildEntityEvent;
use pocketmine\event\entity\EntityDamageByEntityEvent;
use pocketmine\event\entity\EntityDamageEvent;
use pocketmine\event\entity\EntityDeathEvent;
use pocketmine\event\entity\EntityFrostWalkerEvent;
use pocketmine\inventory\ArmorInventory;
use pocketmine\inventory\CallbackInventoryListener;
use pocketmine\inventory\Inventory;
use pocketmine\item\Armor;
use pocketmine\item\Durable;
use pocketmine\item\enchantment\Enchantment;
use pocketmine\item\enchantment\VanillaEnchantments;
use pocketmine\item\Item;
use pocketmine\math\AxisAlignedBB;
use pocketmine\math\Vector3;
use pocketmine\math\VoxelRayTrace;
use pocketmine\nbt\tag\CompoundTag;
use pocketmine\nbt\tag\FloatTag;
use pocketmine\nbt\tag\ListTag;
use pocketmine\nbt\tag\ShortTag;
use pocketmine\network\mcpe\EntityEventBroadcaster;
use pocketmine\network\mcpe\NetworkBroadcastUtils;
use pocketmine\network\mcpe\protocol\types\entity\EntityMetadataCollection;
use pocketmine\network\mcpe\protocol\types\entity\EntityMetadataFlags;
use pocketmine\network\mcpe\protocol\types\entity\EntityMetadataProperties;
use pocketmine\player\Player;
use pocketmine\timings\Timings;
use pocketmine\utils\Binary;
use pocketmine\utils\Utils;
use pocketmine\world\sound\BurpSound;
use pocketmine\world\sound\EntityLandSound;
use pocketmine\world\sound\EntityLongFallSound;
use pocketmine\world\sound\EntityShortFallSound;
use pocketmine\world\sound\ItemBreakSound;
use function abs;
use function array_shift;
use function atan2;
use function ceil;
use function count;
use function floor;
use function ksort;
use function max;
use function min;
use function mt_getrandmax;
use function mt_rand;
use function round;
use function sqrt;
use const M_PI;
use const SORT_NUMERIC;
 
abstract class Living extends Entity{
    protected const DEFAULT_BREATH_TICKS = 300;
 
    public const DEFAULT_KNOCKBACK_FORCE = 0.4;
    public const DEFAULT_KNOCKBACK_VERTICAL_LIMIT = 0.4;
 
    private const TAG_LEGACY_HEALTH = "HealF"; //TAG_Float
    private const TAG_HEALTH = "Health"; //TAG_Float
    private const TAG_BREATH_TICKS = "Air"; //TAG_Short
    private const TAG_ACTIVE_EFFECTS = "ActiveEffects"; //TAG_List<TAG_Compound>
    private const TAG_EFFECT_ID = "Id"; //TAG_Byte
    private const TAG_EFFECT_DURATION = "Duration"; //TAG_Int
    private const TAG_EFFECT_AMPLIFIER = "Amplifier"; //TAG_Byte
    private const TAG_EFFECT_SHOW_PARTICLES = "ShowParticles"; //TAG_Byte
    private const TAG_EFFECT_AMBIENT = "Ambient"; //TAG_Byte
 
    protected int $attackTime = 0;
 
    public int $deadTicks = 0;
    protected int $maxDeadTicks = 25;
 
    protected float $jumpVelocity = 0.42;
 
    protected EffectManager $effectManager;
 
    protected ArmorInventory $armorInventory;
 
    protected bool $breathing = true;
    protected int $breathTicks = self::DEFAULT_BREATH_TICKS;
    protected int $maxBreathTicks = self::DEFAULT_BREATH_TICKS;
 
    protected Attribute $healthAttr;
    protected Attribute $absorptionAttr;
    protected Attribute $knockbackResistanceAttr;
    protected Attribute $moveSpeedAttr;
 
    protected bool $sprinting = false;
    protected bool $sneaking = false;
    protected bool $gliding = false;
    protected bool $swimming = false;
 
    private ?int $frostWalkerLevel = null;
 
    protected function getInitialDragMultiplier() : float{ return 0.02; }
 
    protected function getInitialGravity() : float{ return 0.08; }
 
    abstract public function getName() : string;
 
    public function canBeRenamed() : bool{
        return true;
    }
 
    protected function initEntity(CompoundTag $nbt) : void{
        parent::initEntity($nbt);
 
        $this->effectManager = new EffectManager($this);
        $this->effectManager->getEffectAddHooks()->add(function() : void{ $this->networkPropertiesDirty = true; });
        $this->effectManager->getEffectRemoveHooks()->add(function() : void{ $this->networkPropertiesDirty = true; });
 
        $this->armorInventory = new ArmorInventory($this);
        //TODO: load/save armor inventory contents
        $this->armorInventory->getListeners()->add(CallbackInventoryListener::onAnyChange(fn() => NetworkBroadcastUtils::broadcastEntityEvent(
            $this->getViewers(),
            fn(EntityEventBroadcaster $broadcaster, array $recipients) => $broadcaster->onMobArmorChange($recipients, $this)
        )));
        $this->armorInventory->getListeners()->add(new CallbackInventoryListener(
            onSlotChange: function(Inventory $inventory, int $slot) : void{
                if($slot === ArmorInventory::SLOT_FEET){
                    $this->frostWalkerLevel = null;
                }
            },
            onContentChange: function() : void{ $this->frostWalkerLevel = null; }
        ));
 
        $health = $this->getMaxHealth();
 
        if(($healFTag = $nbt->getTag(self::TAG_LEGACY_HEALTH)) instanceof FloatTag){
            $health = $healFTag->getValue();
        }elseif(($healthTag = $nbt->getTag(self::TAG_HEALTH)) instanceof ShortTag){
            $health = $healthTag->getValue(); //Older versions of PocketMine-MP incorrectly saved this as a short instead of a float
        }elseif($healthTag instanceof FloatTag){
            $health = $healthTag->getValue();
        }
 
        $this->setHealth($health);
 
        $this->setAirSupplyTicks($nbt->getShort(self::TAG_BREATH_TICKS, self::DEFAULT_BREATH_TICKS));
 
        $activeEffectsTag = $nbt->getListTag(self::TAG_ACTIVE_EFFECTS);
        if($activeEffectsTag !== null){
            foreach($activeEffectsTag as $e){
                $effect = EffectIdMap::getInstance()->fromId($e->getByte(self::TAG_EFFECT_ID));
                if($effect === null){
                    continue;
                }
 
                $this->effectManager->add(new EffectInstance(
                    $effect,
                    $e->getInt(self::TAG_EFFECT_DURATION),
                    Binary::unsignByte($e->getByte(self::TAG_EFFECT_AMPLIFIER)),
                    $e->getByte(self::TAG_EFFECT_SHOW_PARTICLES, 1) !== 0,
                    $e->getByte(self::TAG_EFFECT_AMBIENT, 0) !== 0
                ));
            }
        }
    }
 
    protected function addAttributes() : void{
        $this->attributeMap->add($this->healthAttr = AttributeFactory::getInstance()->mustGet(Attribute::HEALTH));
        $this->attributeMap->add(AttributeFactory::getInstance()->mustGet(Attribute::FOLLOW_RANGE));
        $this->attributeMap->add($this->knockbackResistanceAttr = AttributeFactory::getInstance()->mustGet(Attribute::KNOCKBACK_RESISTANCE));
        $this->attributeMap->add($this->moveSpeedAttr = AttributeFactory::getInstance()->mustGet(Attribute::MOVEMENT_SPEED));
        $this->attributeMap->add(AttributeFactory::getInstance()->mustGet(Attribute::ATTACK_DAMAGE));
        $this->attributeMap->add($this->absorptionAttr = AttributeFactory::getInstance()->mustGet(Attribute::ABSORPTION));
    }
 
    public function getDisplayName() : string{
        return $this->nameTag !== "" ? $this->nameTag : $this->getName();
    }
 
    public function setHealth(float $amount) : void{
        $wasAlive = $this->isAlive();
        parent::setHealth($amount);
        $this->healthAttr->setValue(ceil($this->getHealth()), true);
        if($this->isAlive() && !$wasAlive){
            $this->broadcastAnimation(new RespawnAnimation($this));
        }
    }
 
    public function getMaxHealth() : int{
        return (int) $this->healthAttr->getMaxValue();
    }
 
    public function setMaxHealth(int $amount) : void{
        $this->healthAttr->setMaxValue($amount)->setDefaultValue($amount);
    }
 
    public function getAbsorption() : float{
        return $this->absorptionAttr->getValue();
    }
 
    public function setAbsorption(float $absorption) : void{
        $this->absorptionAttr->setValue($absorption);
    }
 
    public function isSneaking() : bool{
        return $this->sneaking;
    }
 
    public function setSneaking(bool $value = true) : void{
        $this->sneaking = $value;
        $this->networkPropertiesDirty = true;
        $this->recalculateSize();
    }
 
    public function isSprinting() : bool{
        return $this->sprinting;
    }
 
    public function setSprinting(bool $value = true) : void{
        if($value !== $this->isSprinting()){
            $this->sprinting = $value;
            $this->networkPropertiesDirty = true;
            $moveSpeed = $this->getMovementSpeed();
            $this->setMovementSpeed($value ? ($moveSpeed * 1.3) : ($moveSpeed / 1.3));
            $this->moveSpeedAttr->markSynchronized(false); //TODO: reevaluate this hack
        }
    }
 
    public function isGliding() : bool{
        return $this->gliding;
    }
 
    public function setGliding(bool $value = true) : void{
        $this->gliding = $value;
        $this->networkPropertiesDirty = true;
        $this->recalculateSize();
    }
 
    public function isSwimming() : bool{
        return $this->swimming;
    }
 
    public function setSwimming(bool $value = true) : void{
        $this->swimming = $value;
        $this->networkPropertiesDirty = true;
        $this->recalculateSize();
    }
 
    private function recalculateSize() : void{
        $size = $this->getInitialSizeInfo();
        if($this->isSwimming() || $this->isGliding()){
            $width = $size->getWidth();
            $this->setSize((new EntitySizeInfo($width, $width, $width * 0.9))->scale($this->getScale()));
        }elseif($this->isSneaking()){
            $this->setSize((new EntitySizeInfo(3 / 4 * $size->getHeight(), $size->getWidth(), 3 / 4 * $size->getEyeHeight()))->scale($this->getScale()));
        }else{
            $this->setSize($size->scale($this->getScale()));
        }
    }
 
    public function getMovementSpeed() : float{
        return $this->moveSpeedAttr->getValue();
    }
 
    public function setMovementSpeed(float $v, bool $fit = false) : void{
        $this->moveSpeedAttr->setValue($v, $fit);
    }
 
    public function saveNBT() : CompoundTag{
        $nbt = parent::saveNBT();
        $nbt->setFloat(self::TAG_HEALTH, $this->getHealth());
 
        $nbt->setShort(self::TAG_BREATH_TICKS, $this->getAirSupplyTicks());
 
        if(count($this->effectManager->all()) > 0){
            $effects = [];
            foreach($this->effectManager->all() as $effect){
                $effects[] = CompoundTag::create()
                    ->setByte(self::TAG_EFFECT_ID, EffectIdMap::getInstance()->toId($effect->getType()))
                    ->setByte(self::TAG_EFFECT_AMPLIFIER, Binary::signByte($effect->getAmplifier()))
                    ->setInt(self::TAG_EFFECT_DURATION, $effect->getDuration())
                    ->setByte(self::TAG_EFFECT_AMBIENT, $effect->isAmbient() ? 1 : 0)
                    ->setByte(self::TAG_EFFECT_SHOW_PARTICLES, $effect->isVisible() ? 1 : 0);
            }
 
            $nbt->setTag(self::TAG_ACTIVE_EFFECTS, new ListTag($effects));
        }
 
        return $nbt;
    }
 
    public function getEffects() : EffectManager{
        return $this->effectManager;
    }
 
    public function consumeObject(Consumable $consumable) : bool{
        $this->applyConsumptionResults($consumable);
        return true;
    }
 
    protected function applyConsumptionResults(Consumable $consumable) : void{
        foreach($consumable->getAdditionalEffects() as $effect){
            $this->effectManager->add($effect);
        }
        if($consumable instanceof FoodSource){
            $this->broadcastSound(new BurpSound());
        }
 
        $consumable->onConsume($this);
    }
 
    public function getJumpVelocity() : float{
        return $this->jumpVelocity + ((($jumpBoost = $this->effectManager->get(VanillaEffects::JUMP_BOOST())) !== null ? $jumpBoost->getEffectLevel() : 0) / 10);
    }
 
    public function jump() : void{
        if($this->onGround){
            $this->motion = $this->motion->withComponents(null, $this->getJumpVelocity(), null); //Y motion should already be 0 if we're jumping from the ground.
        }
    }
 
    protected function calculateFallDamage(float $fallDistance) : float{
        return ceil($fallDistance - 3 - (($jumpBoost = $this->effectManager->get(VanillaEffects::JUMP_BOOST())) !== null ? $jumpBoost->getEffectLevel() : 0));
    }
 
    protected function onHitGround() : ?float{
        $fallBlockPos = $this->location->floor();
        $fallBlock = $this->getWorld()->getBlock($fallBlockPos);
        if(count($fallBlock->getCollisionBoxes()) === 0){
            $fallBlockPos = $fallBlockPos->down();
            $fallBlock = $this->getWorld()->getBlock($fallBlockPos);
        }
        $newVerticalVelocity = $fallBlock->onEntityLand($this);
 
        $damage = $this->calculateFallDamage($this->fallDistance);
        if($damage > 0){
            $ev = new EntityDamageEvent($this, EntityDamageEvent::CAUSE_FALL, $damage);
            $this->attack($ev);
 
            $this->broadcastSound($damage > 4 ?
                new EntityLongFallSound($this) :
                new EntityShortFallSound($this)
            );
        }elseif($fallBlock->getTypeId() !== BlockTypeIds::AIR){
            $this->broadcastSound(new EntityLandSound($this, $fallBlock));
        }
        return $newVerticalVelocity;
    }
 
    public function getArmorPoints() : int{
        $total = 0;
        foreach($this->armorInventory->getContents() as $item){
            $total += $item->getDefensePoints();
        }
 
        return $total;
    }
 
    public function getHighestArmorEnchantmentLevel(Enchantment $enchantment) : int{
        $result = 0;
        foreach($this->armorInventory->getContents() as $item){
            $result = max($result, $item->getEnchantmentLevel($enchantment));
        }
 
        return $result;
    }
 
    public function getArmorInventory() : ArmorInventory{
        return $this->armorInventory;
    }
 
    public function setOnFire(int $seconds) : void{
        parent::setOnFire($seconds - (int) min($seconds, $seconds * $this->getHighestArmorEnchantmentLevel(VanillaEnchantments::FIRE_PROTECTION()) * 0.15));
    }
 
    public function applyDamageModifiers(EntityDamageEvent $source) : void{
        if($this->lastDamageCause !== null && $this->attackTime > 0){
            if($this->lastDamageCause->getBaseDamage() >= $source->getBaseDamage()){
                $source->cancel();
            }
            $source->setModifier(-$this->lastDamageCause->getBaseDamage(), EntityDamageEvent::MODIFIER_PREVIOUS_DAMAGE_COOLDOWN);
        }
        if($source->canBeReducedByArmor()){
            //MCPE uses the same system as PC did pre-1.9
            $source->setModifier(-$source->getFinalDamage() * $this->getArmorPoints() * 0.04, EntityDamageEvent::MODIFIER_ARMOR);
        }
 
        $cause = $source->getCause();
        if(($resistance = $this->effectManager->get(VanillaEffects::RESISTANCE())) !== null && $cause !== EntityDamageEvent::CAUSE_VOID && $cause !== EntityDamageEvent::CAUSE_SUICIDE){
            $source->setModifier(-$source->getFinalDamage() * min(1, 0.2 * $resistance->getEffectLevel()), EntityDamageEvent::MODIFIER_RESISTANCE);
        }
 
        $totalEpf = 0;
        foreach($this->armorInventory->getContents() as $item){
            if($item instanceof Armor){
                $totalEpf += $item->getEnchantmentProtectionFactor($source);
            }
        }
        $source->setModifier(-$source->getFinalDamage() * min(ceil(min($totalEpf, 25) * (mt_rand(50, 100) / 100)), 20) * 0.04, EntityDamageEvent::MODIFIER_ARMOR_ENCHANTMENTS);
 
        $source->setModifier(-min($this->getAbsorption(), $source->getFinalDamage()), EntityDamageEvent::MODIFIER_ABSORPTION);
 
        if($cause === EntityDamageEvent::CAUSE_FALLING_BLOCK && $this->armorInventory->getHelmet() instanceof Armor){
            $source->setModifier(-($source->getFinalDamage() / 4), EntityDamageEvent::MODIFIER_ARMOR_HELMET);
        }
    }
 
    protected function applyPostDamageEffects(EntityDamageEvent $source) : void{
        $this->setAbsorption(max(0, $this->getAbsorption() + $source->getModifier(EntityDamageEvent::MODIFIER_ABSORPTION)));
        if($source->canBeReducedByArmor()){
            $this->damageArmor($source->getBaseDamage());
        }
 
        if($source instanceof EntityDamageByEntityEvent && ($attacker = $source->getDamager()) !== null){
            $damage = 0;
            foreach($this->armorInventory->getContents() as $k => $item){
                if($item instanceof Armor && ($thornsLevel = $item->getEnchantmentLevel(VanillaEnchantments::THORNS())) > 0){
                    if(mt_rand(0, 99) < $thornsLevel * 15){
                        $this->damageItem($item, 3);
                        $damage += ($thornsLevel > 10 ? $thornsLevel - 10 : 1 + mt_rand(0, 3));
                    }else{
                        $this->damageItem($item, 1); //thorns causes an extra +1 durability loss even if it didn't activate
                    }
 
                    $this->armorInventory->setItem($k, $item);
                }
            }
 
            if($damage > 0){
                $attacker->attack(new EntityDamageByEntityEvent($this, $attacker, EntityDamageEvent::CAUSE_MAGIC, $damage));
            }
 
            if($source->getModifier(EntityDamageEvent::MODIFIER_ARMOR_HELMET) < 0){
                $helmet = $this->armorInventory->getHelmet();
                if($helmet instanceof Armor){
                    $finalDamage = $source->getFinalDamage();
                    $this->damageItem($helmet, (int) round($finalDamage * 4 + Utils::getRandomFloat() * $finalDamage * 2));
                    $this->armorInventory->setHelmet($helmet);
                }
            }
        }
    }
 
    public function damageArmor(float $damage) : void{
        $durabilityRemoved = (int) max(floor($damage / 4), 1);
 
        $armor = $this->armorInventory->getContents();
        foreach($armor as $slotId => $item){
            if($item instanceof Armor){
                $oldItem = clone $item;
                $this->damageItem($item, $durabilityRemoved);
                if(!$item->equalsExact($oldItem)){
                    $this->armorInventory->setItem($slotId, $item);
                }
            }
        }
    }
 
    private function damageItem(Durable $item, int $durabilityRemoved) : void{
        $item->applyDamage($durabilityRemoved);
        if($item->isBroken()){
            $this->broadcastSound(new ItemBreakSound());
        }
    }
 
    public function attack(EntityDamageEvent $source) : void{
        if($this->noDamageTicks > 0 && $source->getCause() !== EntityDamageEvent::CAUSE_SUICIDE){
            $source->cancel();
        }
 
        if($this->effectManager->has(VanillaEffects::FIRE_RESISTANCE()) && (
                $source->getCause() === EntityDamageEvent::CAUSE_FIRE
                || $source->getCause() === EntityDamageEvent::CAUSE_FIRE_TICK
                || $source->getCause() === EntityDamageEvent::CAUSE_LAVA
            )
        ){
            $source->cancel();
        }
 
        if($source->getCause() !== EntityDamageEvent::CAUSE_SUICIDE){
            $this->applyDamageModifiers($source);
        }
 
        if($source instanceof EntityDamageByEntityEvent && (
            $source->getCause() === EntityDamageEvent::CAUSE_BLOCK_EXPLOSION ||
            $source->getCause() === EntityDamageEvent::CAUSE_ENTITY_EXPLOSION)
        ){
            //TODO: knockback should not just apply for entity damage sources
            //this doesn't matter for TNT right now because the PrimedTNT entity is considered the source, not the block.
            $base = $source->getKnockBack();
            $source->setKnockBack($base - min($base, $base * $this->getHighestArmorEnchantmentLevel(VanillaEnchantments::BLAST_PROTECTION()) * 0.15));
        }
 
        parent::attack($source);
 
        if($source->isCancelled()){
            return;
        }
 
        if($this->attackTime <= 0){
            //this logic only applies if the entity was cold attacked
 
            $this->attackTime = $source->getAttackCooldown();
 
            if($source instanceof EntityDamageByChildEntityEvent){
                $e = $source->getChild();
                if($e !== null){
                    $motion = $e->getMotion();
                    $this->knockBack($motion->x, $motion->z, $source->getKnockBack(), $source->getVerticalKnockBackLimit());
                }
            }elseif($source instanceof EntityDamageByEntityEvent){
                $e = $source->getDamager();
                if($e !== null){
                    $deltaX = $this->location->x - $e->location->x;
                    $deltaZ = $this->location->z - $e->location->z;
                    $this->knockBack($deltaX, $deltaZ, $source->getKnockBack(), $source->getVerticalKnockBackLimit());
                }
            }
 
            if($this->isAlive()){
                $this->doHitAnimation();
            }
        }
 
        if($this->isAlive()){
            $this->applyPostDamageEffects($source);
        }
    }
 
    protected function doHitAnimation() : void{
        $this->broadcastAnimation(new HurtAnimation($this));
    }
 
    public function knockBack(float $x, float $z, float $force = self::DEFAULT_KNOCKBACK_FORCE, ?float $verticalLimit = self::DEFAULT_KNOCKBACK_VERTICAL_LIMIT) : void{
        $f = sqrt($x * $x + $z * $z);
        if($f <= 0){
            return;
        }
        if(mt_rand() / mt_getrandmax() > $this->knockbackResistanceAttr->getValue()){
            $f = 1 / $f;
 
            $motionX = $this->motion->x / 2;
            $motionY = $this->motion->y / 2;
            $motionZ = $this->motion->z / 2;
            $motionX += $x * $f * $force;
            $motionY += $force;
            $motionZ += $z * $f * $force;
 
            $verticalLimit ??= $force;
            if($motionY > $verticalLimit){
                $motionY = $verticalLimit;
            }
 
            $this->setMotion(new Vector3($motionX, $motionY, $motionZ));
        }
    }
 
    protected function onDeath() : void{
        $ev = new EntityDeathEvent($this, $this->getDrops(), $this->getXpDropAmount());
        $ev->call();
        foreach($ev->getDrops() as $item){
            $this->getWorld()->dropItem($this->location, $item);
        }
 
        //TODO: check death conditions (must have been damaged by player < 5 seconds from death)
        $this->getWorld()->dropExperience($this->location, $ev->getXpDropAmount());
 
        $this->startDeathAnimation();
    }
 
    protected function onDeathUpdate(int $tickDiff) : bool{
        if($this->deadTicks < $this->maxDeadTicks){
            $this->deadTicks += $tickDiff;
            if($this->deadTicks >= $this->maxDeadTicks){
                $this->endDeathAnimation();
            }
        }
 
        return $this->deadTicks >= $this->maxDeadTicks;
    }
 
    protected function startDeathAnimation() : void{
        $this->broadcastAnimation(new DeathAnimation($this));
    }
 
    protected function endDeathAnimation() : void{
        $this->despawnFromAll();
    }
 
    protected function entityBaseTick(int $tickDiff = 1) : bool{
        Timings::$livingEntityBaseTick->startTiming();
 
        $hasUpdate = parent::entityBaseTick($tickDiff);
 
        if($this->isAlive()){
            if($this->effectManager->tick($tickDiff)){
                $hasUpdate = true;
            }
 
            if($this->isInsideOfSolid()){
                $hasUpdate = true;
                $ev = new EntityDamageEvent($this, EntityDamageEvent::CAUSE_SUFFOCATION, 1);
                $this->attack($ev);
            }
 
            if($this->doAirSupplyTick($tickDiff)){
                $hasUpdate = true;
            }
 
            foreach($this->armorInventory->getContents() as $index => $item){
                $oldItem = clone $item;
                if($item->onTickWorn($this)){
                    $hasUpdate = true;
                    if(!$item->equalsExact($oldItem)){
                        $this->armorInventory->setItem($index, $item);
                    }
                }
            }
        }
 
        if($this->attackTime > 0){
            $this->attackTime -= $tickDiff;
        }
 
        Timings::$livingEntityBaseTick->stopTiming();
 
        return $hasUpdate;
    }
 
    protected function move(float $dx, float $dy, float $dz) : void{
        $oldX = $this->location->x;
        $oldZ = $this->location->z;
 
        parent::move($dx, $dy, $dz);
 
        $frostWalkerLevel = $this->getFrostWalkerLevel();
        if($frostWalkerLevel > 0 && (abs($this->location->x - $oldX) > self::MOTION_THRESHOLD || abs($this->location->z - $oldZ) > self::MOTION_THRESHOLD)){
            $this->applyFrostWalker($frostWalkerLevel);
        }
    }
 
    protected function applyFrostWalker(int $level) : void{
        $radius = $level + 2;
        $world = $this->getWorld();
 
        $baseX = $this->location->getFloorX();
        $y = $this->location->getFloorY() - 1;
        $baseZ = $this->location->getFloorZ();
 
        $liquid = VanillaBlocks::WATER();
        $targetBlock = VanillaBlocks::FROSTED_ICE();
        if(EntityFrostWalkerEvent::hasHandlers()){
            $ev = new EntityFrostWalkerEvent($this, $radius, $liquid, $targetBlock);
            $ev->call();
            if($ev->isCancelled()){
                return;
            }
            $radius = $ev->getRadius();
            $liquid = $ev->getLiquid();
            $targetBlock = $ev->getTargetBlock();
        }
 
        for($x = $baseX - $radius; $x <= $baseX + $radius; $x++){
            for($z = $baseZ - $radius; $z <= $baseZ + $radius; $z++){
                $block = $world->getBlockAt($x, $y, $z);
                if(
                    !$block->isSameState($liquid) ||
                    $world->getBlockAt($x, $y + 1, $z)->getTypeId() !== BlockTypeIds::AIR ||
                    count($world->getNearbyEntities(AxisAlignedBB::one()->offset($x, $y, $z))) !== 0
                ){
                    continue;
                }
                $world->setBlockAt($x, $y, $z, $targetBlock);
            }
        }
    }
 
    public function getFrostWalkerLevel() : int{
        return $this->frostWalkerLevel ??= $this->armorInventory->getBoots()->getEnchantmentLevel(VanillaEnchantments::FROST_WALKER());
    }
 
    protected function doAirSupplyTick(int $tickDiff) : bool{
        $ticks = $this->getAirSupplyTicks();
        $oldTicks = $ticks;
        if(!$this->canBreathe()){
            $this->setBreathing(false);
 
            if(($respirationLevel = $this->armorInventory->getHelmet()->getEnchantmentLevel(VanillaEnchantments::RESPIRATION())) <= 0 ||
                Utils::getRandomFloat() <= (1 / ($respirationLevel + 1))
            ){
                $ticks -= $tickDiff;
                if($ticks <= -20){
                    $ticks = 0;
                    $this->onAirExpired();
                }
            }
        }elseif(!$this->isBreathing()){
            if($ticks < ($max = $this->getMaxAirSupplyTicks())){
                $ticks += $tickDiff * 5;
            }
            if($ticks >= $max){
                $ticks = $max;
                $this->setBreathing(true);
            }
        }
 
        if($ticks !== $oldTicks){
            $this->setAirSupplyTicks($ticks);
        }
 
        return $ticks !== $oldTicks;
    }
 
    public function canBreathe() : bool{
        return $this->effectManager->has(VanillaEffects::WATER_BREATHING()) || $this->effectManager->has(VanillaEffects::CONDUIT_POWER()) || !$this->isUnderwater();
    }
 
    public function isBreathing() : bool{
        return $this->breathing;
    }
 
    public function setBreathing(bool $value = true) : void{
        $this->breathing = $value;
        $this->networkPropertiesDirty = true;
    }
 
    public function getAirSupplyTicks() : int{
        return $this->breathTicks;
    }
 
    public function setAirSupplyTicks(int $ticks) : void{
        $this->breathTicks = $ticks;
        $this->networkPropertiesDirty = true;
    }
 
    public function getMaxAirSupplyTicks() : int{
        return $this->maxBreathTicks;
    }
 
    public function setMaxAirSupplyTicks(int $ticks) : void{
        $this->maxBreathTicks = $ticks;
        $this->networkPropertiesDirty = true;
    }
 
    public function onAirExpired() : void{
        $ev = new EntityDamageEvent($this, EntityDamageEvent::CAUSE_DROWNING, 2);
        $this->attack($ev);
    }
 
    public function getDrops() : array{
        return [];
    }
 
    public function getXpDropAmount() : int{
        return 0;
    }
 
    public function getLineOfSight(int $maxDistance, int $maxLength = 0, array $transparent = []) : array{
        if($maxDistance > 120){
            $maxDistance = 120;
        }
 
        if(count($transparent) === 0){
            $transparent = null;
        }
 
        $blocks = [];
        $nextIndex = 0;
 
        foreach(VoxelRayTrace::inDirection($this->location->add(0, $this->size->getEyeHeight(), 0), $this->getDirectionVector(), $maxDistance) as $vector3){
            $block = $this->getWorld()->getBlockAt($vector3->x, $vector3->y, $vector3->z);
            $blocks[$nextIndex++] = $block;
 
            if($maxLength !== 0 && count($blocks) > $maxLength){
                array_shift($blocks);
                --$nextIndex;
            }
 
            $id = $block->getTypeId();
 
            if($transparent === null){
                if($id !== BlockTypeIds::AIR){
                    break;
                }
            }else{
                if(!isset($transparent[$id])){
                    break;
                }
            }
        }
 
        return $blocks;
    }
 
    public function getTargetBlock(int $maxDistance, array $transparent = []) : ?Block{
        $line = $this->getLineOfSight($maxDistance, 1, $transparent);
        if(count($line) > 0){
            return array_shift($line);
        }
 
        return null;
    }
 
    public function lookAt(Vector3 $target) : void{
        $horizontal = sqrt(($target->x - $this->location->x) ** 2 + ($target->z - $this->location->z) ** 2);
        $vertical = $target->y - ($this->location->y + $this->getEyeHeight());
        $pitch = -atan2($vertical, $horizontal) / M_PI * 180; //negative is up, positive is down
 
        $xDist = $target->x - $this->location->x;
        $zDist = $target->z - $this->location->z;
 
        $yaw = atan2($zDist, $xDist) / M_PI * 180 - 90;
        if($yaw < 0){
            $yaw += 360.0;
        }
 
        $this->setRotation($yaw, $pitch);
    }
 
    protected function sendSpawnPacket(Player $player) : void{
        parent::sendSpawnPacket($player);
 
        $networkSession = $player->getNetworkSession();
        $networkSession->getEntityEventBroadcaster()->onMobArmorChange([$networkSession], $this);
    }
 
    protected function syncNetworkData(EntityMetadataCollection $properties) : void{
        parent::syncNetworkData($properties);
 
        $visibleEffects = [];
        foreach ($this->effectManager->all() as $effect) {
            if (!$effect->isVisible() || !$effect->getType()->hasBubbles()) {
                continue;
            }
            $visibleEffects[EffectIdMap::getInstance()->toId($effect->getType())] = $effect->isAmbient();
        }
 
        //TODO: HACK! the client may not be able to identify effects if they are not sorted.
        ksort($visibleEffects, SORT_NUMERIC);
 
        $effectsData = 0;
        $packedEffectsCount = 0;
        foreach ($visibleEffects as $effectId => $isAmbient) {
            $effectsData = ($effectsData << 7) |
                (($effectId & 0x3f) << 1) | //Why not use 7 bits instead of only 6? mojang...
                ($isAmbient ? 1 : 0);
 
            if (++$packedEffectsCount >= 8) {
                break;
            }
        }
        $properties->setLong(EntityMetadataProperties::VISIBLE_MOB_EFFECTS, $effectsData);
 
        $properties->setShort(EntityMetadataProperties::AIR, $this->breathTicks);
        $properties->setShort(EntityMetadataProperties::MAX_AIR, $this->maxBreathTicks);
 
        $properties->setGenericFlag(EntityMetadataFlags::BREATHING, $this->breathing);
        $properties->setGenericFlag(EntityMetadataFlags::SNEAKING, $this->sneaking);
        $properties->setGenericFlag(EntityMetadataFlags::SPRINTING, $this->sprinting);
        $properties->setGenericFlag(EntityMetadataFlags::GLIDING, $this->gliding);
        $properties->setGenericFlag(EntityMetadataFlags::SWIMMING, $this->swimming);
    }
 
    protected function onDispose() : void{
        $this->armorInventory->removeAllViewers();
        $this->effectManager->getEffectAddHooks()->clear();
        $this->effectManager->getEffectRemoveHooks()->clear();
        parent::onDispose();
    }
 
    protected function destroyCycles() : void{
        unset(
            $this->armorInventory,
            $this->effectManager
        );
        parent::destroyCycles();
    }
}