Entity.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\Water;
use pocketmine\entity\animation\Animation;
use pocketmine\event\entity\EntityDamageEvent;
use pocketmine\event\entity\EntityDespawnEvent;
use pocketmine\event\entity\EntityMotionEvent;
use pocketmine\event\entity\EntityRegainHealthEvent;
use pocketmine\event\entity\EntitySpawnEvent;
use pocketmine\event\entity\EntityTeleportEvent;
use pocketmine\item\Item;
use pocketmine\math\AxisAlignedBB;
use pocketmine\math\Facing;
use pocketmine\math\Vector2;
use pocketmine\math\Vector3;
use pocketmine\nbt\tag\CompoundTag;
use pocketmine\nbt\tag\DoubleTag;
use pocketmine\nbt\tag\FloatTag;
use pocketmine\nbt\tag\ListTag;
use pocketmine\nbt\tag\StringTag;
use pocketmine\network\mcpe\EntityEventBroadcaster;
use pocketmine\network\mcpe\NetworkBroadcastUtils;
use pocketmine\network\mcpe\protocol\AddActorPacket;
use pocketmine\network\mcpe\protocol\MoveActorAbsolutePacket;
use pocketmine\network\mcpe\protocol\SetActorMotionPacket;
use pocketmine\network\mcpe\protocol\types\entity\Attribute as NetworkAttribute;
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\network\mcpe\protocol\types\entity\MetadataProperty;
use pocketmine\network\mcpe\protocol\types\entity\PropertySyncData;
use pocketmine\player\Player;
use pocketmine\Server;
use pocketmine\timings\Timings;
use pocketmine\timings\TimingsHandler;
use pocketmine\utils\Utils;
use pocketmine\VersionInfo;
use pocketmine\world\format\Chunk;
use pocketmine\world\Position;
use pocketmine\world\sound\Sound;
use pocketmine\world\World;
use function abs;
use function array_map;
use function assert;
use function cos;
use function count;
use function deg2rad;
use function floor;
use function fmod;
use function get_class;
use function sin;
use function spl_object_id;
use const M_PI_2;
 
abstract class Entity{
 
    public const MOTION_THRESHOLD = 0.00001;
    protected const STEP_CLIP_MULTIPLIER = 0.4;
 
    private const TAG_FIRE = "Fire"; //TAG_Short
    private const TAG_ON_GROUND = "OnGround"; //TAG_Byte
    private const TAG_FALL_DISTANCE = "FallDistance"; //TAG_Float
    private const TAG_CUSTOM_NAME = "CustomName"; //TAG_String
    private const TAG_CUSTOM_NAME_VISIBLE = "CustomNameVisible"; //TAG_Byte
    public const TAG_POS = "Pos"; //TAG_List<TAG_Double>|TAG_List<TAG_Float>
    public const TAG_MOTION = "Motion"; //TAG_List<TAG_Double>|TAG_List<TAG_Float>
    public const TAG_ROTATION = "Rotation"; //TAG_List<TAG_Float>
 
    private static int $entityCount = 1;
 
    public static function nextRuntimeId() : int{
        return self::$entityCount++;
    }
 
    protected array $hasSpawned = [];
 
    protected int $id;
 
    private EntityMetadataCollection $networkProperties;
 
    protected ?EntityDamageEvent $lastDamageCause = null;
 
    protected ?array $blocksAround = null;
 
    protected Location $location;
    protected Location $lastLocation;
    protected Vector3 $motion;
    protected Vector3 $lastMotion;
    protected bool $forceMovementUpdate = false;
    private bool $checkBlockIntersectionsNextTick = true;
 
    public AxisAlignedBB $boundingBox;
    public bool $onGround = false;
 
    public EntitySizeInfo $size;
 
    private float $health = 20.0;
    private int $maxHealth = 20;
 
    protected float $ySize = 0.0;
    protected float $stepHeight = 0.0;
    public bool $keepMovement = false;
 
    public float $fallDistance = 0.0;
    public int $ticksLived = 0;
    public int $lastUpdate;
    protected int $fireTicks = 0;
 
    private bool $savedWithChunk = true;
 
    public bool $isCollided = false;
    public bool $isCollidedHorizontally = false;
    public bool $isCollidedVertically = false;
 
    public int $noDamageTicks = 0;
    protected bool $justCreated = true;
 
    protected AttributeMap $attributeMap;
 
    protected float $gravity;
    protected float $drag;
    protected bool $gravityEnabled = true;
 
    protected Server $server;
 
    protected bool $closed = false;
    private bool $closeInFlight = false;
    private bool $needsDespawn = false;
 
    protected TimingsHandler $timings;
 
    protected bool $networkPropertiesDirty = false;
 
    protected string $nameTag = "";
    protected bool $nameTagVisible = true;
    protected bool $alwaysShowNameTag = false;
    protected string $scoreTag = "";
    protected float $scale = 1.0;
 
    protected bool $canClimb = false;
    protected bool $canClimbWalls = false;
    protected bool $noClientPredictions = false;
    protected bool $invisible = false;
    protected bool $silent = false;
 
    protected ?int $ownerId = null;
    protected ?int $targetId = null;
 
    private bool $constructorCalled = false;
 
    public function __construct(Location $location, ?CompoundTag $nbt = null){
        if($this->constructorCalled){
            throw new \LogicException("Attempted to call constructor for an Entity multiple times");
        }
        $this->constructorCalled = true;
        Utils::checkLocationNotInfOrNaN($location);
 
        $this->timings = Timings::getEntityTimings($this);
 
        $this->size = $this->getInitialSizeInfo();
        $this->drag = $this->getInitialDragMultiplier();
        $this->gravity = $this->getInitialGravity();
 
        $this->id = self::nextRuntimeId();
        $this->server = $location->getWorld()->getServer();
 
        $this->location = $location->asLocation();
 
        $this->boundingBox = new AxisAlignedBB(0, 0, 0, 0, 0, 0);
        $this->recalculateBoundingBox();
 
        if($nbt !== null){
            $this->motion = EntityDataHelper::parseVec3($nbt, self::TAG_MOTION, true);
        }else{
            $this->motion = Vector3::zero();
        }
 
        $this->resetLastMovements();
 
        $this->networkProperties = new EntityMetadataCollection();
 
        $this->attributeMap = new AttributeMap();
        $this->addAttributes();
 
        $this->initEntity($nbt ?? new CompoundTag());
 
        $this->getWorld()->addEntity($this);
 
        $this->lastUpdate = $this->server->getTick();
 
        $this->scheduleUpdate();
    }
 
    abstract protected function getInitialSizeInfo() : EntitySizeInfo;
 
    abstract protected function getInitialDragMultiplier() : float;
 
    abstract protected function getInitialGravity() : float;
 
    public function getNameTag() : string{
        return $this->nameTag;
    }
 
    public function isNameTagVisible() : bool{
        return $this->nameTagVisible;
    }
 
    public function isNameTagAlwaysVisible() : bool{
        return $this->alwaysShowNameTag;
    }
 
    public function canBeRenamed() : bool{
        return false;
    }
 
    public function setNameTag(string $name) : void{
        $this->nameTag = $name;
        $this->networkPropertiesDirty = true;
    }
 
    public function setNameTagVisible(bool $value = true) : void{
        $this->nameTagVisible = $value;
        $this->networkPropertiesDirty = true;
    }
 
    public function setNameTagAlwaysVisible(bool $value = true) : void{
        $this->alwaysShowNameTag = $value;
        $this->networkPropertiesDirty = true;
    }
 
    public function getScoreTag() : ?string{
        return $this->scoreTag; //TODO: maybe this shouldn't be nullable?
    }
 
    public function setScoreTag(string $score) : void{
        $this->scoreTag = $score;
        $this->networkPropertiesDirty = true;
    }
 
    public function getScale() : float{
        return $this->scale;
    }
 
    public function setScale(float $value) : void{
        if($value <= 0){
            throw new \InvalidArgumentException("Scale must be greater than 0");
        }
        $this->scale = $value;
        $this->setSize($this->getInitialSizeInfo()->scale($value));
    }
 
    public function getBoundingBox() : AxisAlignedBB{
        return $this->boundingBox;
    }
 
    protected function recalculateBoundingBox() : void{
        $halfWidth = $this->size->getWidth() / 2;
 
        $this->boundingBox = new AxisAlignedBB(
            $this->location->x - $halfWidth,
            $this->location->y + $this->ySize,
            $this->location->z - $halfWidth,
            $this->location->x + $halfWidth,
            $this->location->y + $this->size->getHeight() + $this->ySize,
            $this->location->z + $halfWidth
        );
    }
 
    public function getSize() : EntitySizeInfo{
        return $this->size;
    }
 
    protected function setSize(EntitySizeInfo $size) : void{
        $this->size = $size;
        $this->recalculateBoundingBox();
        $this->networkPropertiesDirty = true;
    }
 
    public function hasNoClientPredictions() : bool{
        return $this->noClientPredictions;
    }
 
    public function setNoClientPredictions(bool $value = true) : void{
        $this->noClientPredictions = $value;
        $this->networkPropertiesDirty = true;
    }
 
    public function isInvisible() : bool{
        return $this->invisible;
    }
 
    public function setInvisible(bool $value = true) : void{
        $this->invisible = $value;
        $this->networkPropertiesDirty = true;
    }
 
    public function isSilent() : bool{
        return $this->silent;
    }
 
    public function setSilent(bool $value = true) : void{
        $this->silent = $value;
        $this->networkPropertiesDirty = true;
    }
 
    public function canClimb() : bool{
        return $this->canClimb;
    }
 
    public function setCanClimb(bool $value = true) : void{
        $this->canClimb = $value;
        $this->networkPropertiesDirty = true;
    }
 
    public function canClimbWalls() : bool{
        return $this->canClimbWalls;
    }
 
    public function setCanClimbWalls(bool $value = true) : void{
        $this->canClimbWalls = $value;
        $this->networkPropertiesDirty = true;
    }
 
    public function getOwningEntityId() : ?int{
        return $this->ownerId;
    }
 
    public function getOwningEntity() : ?Entity{
        return $this->ownerId !== null ? $this->server->getWorldManager()->findEntity($this->ownerId) : null;
    }
 
    public function setOwningEntity(?Entity $owner) : void{
        if($owner === null){
            $this->ownerId = null;
        }elseif($owner->closed){
            throw new \InvalidArgumentException("Supplied owning entity is garbage and cannot be used");
        }else{
            $this->ownerId = $owner->getId();
        }
        $this->networkPropertiesDirty = true;
    }
 
    public function getTargetEntityId() : ?int{
        return $this->targetId;
    }
 
    public function getTargetEntity() : ?Entity{
        return $this->targetId !== null ? $this->server->getWorldManager()->findEntity($this->targetId) : null;
    }
 
    public function setTargetEntity(?Entity $target) : void{
        if($target === null){
            $this->targetId = null;
        }elseif($target->closed){
            throw new \InvalidArgumentException("Supplied target entity is garbage and cannot be used");
        }else{
            $this->targetId = $target->getId();
        }
        $this->networkPropertiesDirty = true;
    }
 
    public function canSaveWithChunk() : bool{
        return $this->savedWithChunk;
    }
 
    public function setCanSaveWithChunk(bool $value) : void{
        $this->savedWithChunk = $value;
    }
 
    public function saveNBT() : CompoundTag{
        $nbt = CompoundTag::create()
            ->setTag(self::TAG_POS, new ListTag([
                new DoubleTag($this->location->x),
                new DoubleTag($this->location->y),
                new DoubleTag($this->location->z)
            ]))
            ->setTag(self::TAG_MOTION, new ListTag([
                new DoubleTag($this->motion->x),
                new DoubleTag($this->motion->y),
                new DoubleTag($this->motion->z)
            ]))
            ->setTag(self::TAG_ROTATION, new ListTag([
                new FloatTag($this->location->yaw),
                new FloatTag($this->location->pitch)
            ]));
 
        if(!($this instanceof Player)){
            EntityFactory::getInstance()->injectSaveId(get_class($this), $nbt);
 
            if($this->getNameTag() !== ""){
                $nbt->setString(self::TAG_CUSTOM_NAME, $this->getNameTag());
                $nbt->setByte(self::TAG_CUSTOM_NAME_VISIBLE, $this->isNameTagVisible() ? 1 : 0);
            }
        }
 
        $nbt->setFloat(self::TAG_FALL_DISTANCE, $this->fallDistance);
        $nbt->setShort(self::TAG_FIRE, $this->fireTicks);
        $nbt->setByte(self::TAG_ON_GROUND, $this->onGround ? 1 : 0);
 
        $nbt->setLong(VersionInfo::TAG_WORLD_DATA_VERSION, VersionInfo::WORLD_DATA_VERSION);
 
        return $nbt;
    }
 
    protected function initEntity(CompoundTag $nbt) : void{
        $this->fireTicks = $nbt->getShort(self::TAG_FIRE, 0);
 
        $this->onGround = $nbt->getByte(self::TAG_ON_GROUND, 0) !== 0;
 
        $this->fallDistance = $nbt->getFloat(self::TAG_FALL_DISTANCE, 0.0);
 
        if(($customNameTag = $nbt->getTag(self::TAG_CUSTOM_NAME)) instanceof StringTag){
            $this->setNameTag($customNameTag->getValue());
 
            if(($customNameVisibleTag = $nbt->getTag(self::TAG_CUSTOM_NAME_VISIBLE)) instanceof StringTag){
                //Older versions incorrectly saved this as a string (see 890f72dbf23a77f294169b79590770470041adc4)
                $this->setNameTagVisible($customNameVisibleTag->getValue() !== "");
            }else{
                $this->setNameTagVisible($nbt->getByte(self::TAG_CUSTOM_NAME_VISIBLE, 1) !== 0);
            }
        }
    }
 
    protected function addAttributes() : void{
 
    }
 
    public function attack(EntityDamageEvent $source) : void{
        if($this->isFireProof() && (
                $source->getCause() === EntityDamageEvent::CAUSE_FIRE ||
                $source->getCause() === EntityDamageEvent::CAUSE_FIRE_TICK ||
                $source->getCause() === EntityDamageEvent::CAUSE_LAVA
            )
        ){
            $source->cancel();
        }
        $source->call();
        if($source->isCancelled()){
            return;
        }
 
        $this->setLastDamageCause($source);
 
        $this->setHealth($this->getHealth() - $source->getFinalDamage());
    }
 
    public function heal(EntityRegainHealthEvent $source) : void{
        $source->call();
        if($source->isCancelled()){
            return;
        }
 
        $this->setHealth($this->getHealth() + $source->getAmount());
    }
 
    public function kill() : void{
        if($this->isAlive()){
            $this->health = 0;
            $this->onDeath();
            $this->scheduleUpdate();
        }
    }
 
    protected function onDeath() : void{
 
    }
 
    protected function onDeathUpdate(int $tickDiff) : bool{
        return true;
    }
 
    public function isAlive() : bool{
        return $this->health > 0;
    }
 
    public function getHealth() : float{
        return $this->health;
    }
 
    public function setHealth(float $amount) : void{
        if($amount == $this->health){
            return;
        }
 
        if($amount <= 0){
            if($this->isAlive()){
                if(!$this->justCreated){
                    $this->kill();
                }else{
                    $this->health = 0;
                }
            }
        }elseif($amount <= $this->getMaxHealth() || $amount < $this->health){
            $this->health = $amount;
        }else{
            $this->health = $this->getMaxHealth();
        }
    }
 
    public function getMaxHealth() : int{
        return $this->maxHealth;
    }
 
    public function setMaxHealth(int $amount) : void{
        $this->maxHealth = $amount;
    }
 
    public function setLastDamageCause(EntityDamageEvent $type) : void{
        $this->lastDamageCause = $type;
    }
 
    public function getLastDamageCause() : ?EntityDamageEvent{
        return $this->lastDamageCause;
    }
 
    public function getAttributeMap() : AttributeMap{
        return $this->attributeMap;
    }
 
    public function getNetworkProperties() : EntityMetadataCollection{
        return $this->networkProperties;
    }
 
    protected function entityBaseTick(int $tickDiff = 1) : bool{
        //TODO: check vehicles
 
        if($this->justCreated){
            $this->justCreated = false;
            if(!$this->isAlive()){
                $this->kill();
            }
        }
 
        $changedProperties = $this->getDirtyNetworkData();
        if(count($changedProperties) > 0){
            $this->sendData(null, $changedProperties);
            $this->networkProperties->clearDirtyProperties();
        }
 
        $hasUpdate = false;
 
        if($this->checkBlockIntersectionsNextTick){
            $this->checkBlockIntersections();
        }
        $this->checkBlockIntersectionsNextTick = true;
 
        if($this->location->y <= World::Y_MIN - 16 && $this->isAlive()){
            $ev = new EntityDamageEvent($this, EntityDamageEvent::CAUSE_VOID, 10);
            $this->attack($ev);
            $hasUpdate = true;
        }
 
        if($this->isOnFire() && $this->doOnFireTick($tickDiff)){
            $hasUpdate = true;
        }
 
        if($this->noDamageTicks > 0){
            $this->noDamageTicks -= $tickDiff;
            if($this->noDamageTicks < 0){
                $this->noDamageTicks = 0;
            }
        }
 
        $this->ticksLived += $tickDiff;
 
        return $hasUpdate;
    }
 
    public function isOnFire() : bool{
        return $this->fireTicks > 0;
    }
 
    public function setOnFire(int $seconds) : void{
        $ticks = $seconds * 20;
        if($ticks > $this->getFireTicks()){
            $this->setFireTicks($ticks);
        }
        $this->networkPropertiesDirty = true;
    }
 
    public function getFireTicks() : int{
        return $this->fireTicks;
    }
 
    public function setFireTicks(int $fireTicks) : void{
        if($fireTicks < 0 || $fireTicks > 0x7fff){
            throw new \InvalidArgumentException("Fire ticks must be in range 0 ... " . 0x7fff . ", got $fireTicks");
        }
        if(!$this->isFireProof()){
            $this->fireTicks = $fireTicks;
            $this->networkPropertiesDirty = true;
        }
    }
 
    public function extinguish() : void{
        $this->fireTicks = 0;
        $this->networkPropertiesDirty = true;
    }
 
    public function isFireProof() : bool{
        return false;
    }
 
    protected function doOnFireTick(int $tickDiff = 1) : bool{
        if($this->isFireProof() && $this->isOnFire()){
            $this->extinguish();
            return false;
        }
 
        $this->fireTicks -= $tickDiff;
 
        if(($this->fireTicks % 20 === 0) || $tickDiff > 20){
            $this->dealFireDamage();
        }
 
        if(!$this->isOnFire()){
            $this->extinguish();
        }else{
            return true;
        }
 
        return false;
    }
 
    protected function dealFireDamage() : void{
        $ev = new EntityDamageEvent($this, EntityDamageEvent::CAUSE_FIRE_TICK, 1);
        $this->attack($ev);
    }
 
    public function canCollideWith(Entity $entity) : bool{
        return !$this->justCreated && $entity !== $this;
    }
 
    public function canBeCollidedWith() : bool{
        return $this->isAlive();
    }
 
    protected function updateMovement(bool $teleport = false) : void{
        $diffPosition = $this->location->distanceSquared($this->lastLocation);
        $diffRotation = ($this->location->yaw - $this->lastLocation->yaw) ** 2 + ($this->location->pitch - $this->lastLocation->pitch) ** 2;
 
        $diffMotion = $this->motion->subtractVector($this->lastMotion)->lengthSquared();
 
        $still = $this->motion->lengthSquared() == 0.0;
        $wasStill = $this->lastMotion->lengthSquared() == 0.0;
        if($wasStill !== $still){
            //TODO: hack for client-side AI interference: prevent client sided movement when motion is 0
            $this->setNoClientPredictions($still);
        }
 
        if($teleport || $diffPosition > 0.0001 || $diffRotation > 1.0 || (!$wasStill && $still)){
            $this->lastLocation = $this->location->asLocation();
 
            $this->broadcastMovement($teleport);
        }
 
        if($diffMotion > 0.0025 || $wasStill !== $still){ //0.05 ** 2
            $this->lastMotion = clone $this->motion;
 
            $this->broadcastMotion();
        }
    }
 
    public function getOffsetPosition(Vector3 $vector3) : Vector3{
        return $vector3;
    }
 
    protected function broadcastMovement(bool $teleport = false) : void{
        NetworkBroadcastUtils::broadcastPackets($this->hasSpawned, [MoveActorAbsolutePacket::create(
            $this->id,
            $this->getOffsetPosition($this->location),
            $this->location->pitch,
            $this->location->yaw,
            $this->location->yaw,
            (
                //TODO: We should be setting FLAG_TELEPORT here to disable client-side movement interpolation, but it
                //breaks player teleporting (observers see the player rubberband back to the pre-teleport position while
                //the teleported player sees themselves at the correct position), and does nothing whatsoever for
                //non-player entities (movement is still interpolated). Both of these are client bugs.
                //See https://github.com/pmmp/PocketMine-MP/issues/4394
                ($this->onGround ? MoveActorAbsolutePacket::FLAG_GROUND : 0)
            )
        )]);
    }
 
    protected function broadcastMotion() : void{
        NetworkBroadcastUtils::broadcastPackets($this->hasSpawned, [SetActorMotionPacket::create($this->id, $this->getMotion(), tick: 0)]);
    }
 
    public function getGravity() : float{
        return $this->gravity;
    }
 
    public function setGravity(float $gravity) : void{
        Utils::checkFloatNotInfOrNaN("gravity", $gravity);
        $this->gravity = $gravity;
    }
 
    public function hasGravity() : bool{
        return $this->gravityEnabled;
    }
 
    public function setHasGravity(bool $v = true) : void{
        $this->gravityEnabled = $v;
    }
 
    protected function applyDragBeforeGravity() : bool{
        return false;
    }
 
    protected function tryChangeMovement() : void{
        $friction = 1 - $this->drag;
 
        $mY = $this->motion->y;
 
        if($this->applyDragBeforeGravity()){
            $mY *= $friction;
        }
 
        if($this->gravityEnabled){
            $mY -= $this->gravity;
        }
 
        if(!$this->applyDragBeforeGravity()){
            $mY *= $friction;
        }
 
        if($this->onGround){
            $friction *= $this->getWorld()->getBlockAt((int) floor($this->location->x), (int) floor($this->location->y - 1), (int) floor($this->location->z))->getFrictionFactor();
        }
 
        $this->motion = new Vector3($this->motion->x * $friction, $mY, $this->motion->z * $friction);
    }
 
    protected function checkObstruction(float $x, float $y, float $z) : bool{
        $world = $this->getWorld();
        if(count($world->getBlockCollisionBoxes($this->boundingBox)) === 0){
            return false;
        }
 
        $floorX = (int) floor($x);
        $floorY = (int) floor($y);
        $floorZ = (int) floor($z);
 
        $diffX = $x - $floorX;
        $diffY = $y - $floorY;
        $diffZ = $z - $floorZ;
 
        if($world->getBlockAt($floorX, $floorY, $floorZ)->isSolid()){
            $westNonSolid = !$world->getBlockAt($floorX - 1, $floorY, $floorZ)->isSolid();
            $eastNonSolid = !$world->getBlockAt($floorX + 1, $floorY, $floorZ)->isSolid();
            $downNonSolid = !$world->getBlockAt($floorX, $floorY - 1, $floorZ)->isSolid();
            $upNonSolid = !$world->getBlockAt($floorX, $floorY + 1, $floorZ)->isSolid();
            $northNonSolid = !$world->getBlockAt($floorX, $floorY, $floorZ - 1)->isSolid();
            $southNonSolid = !$world->getBlockAt($floorX, $floorY, $floorZ + 1)->isSolid();
 
            $direction = -1;
            $limit = 9999;
 
            if($westNonSolid){
                $limit = $diffX;
                $direction = Facing::WEST;
            }
 
            if($eastNonSolid && 1 - $diffX < $limit){
                $limit = 1 - $diffX;
                $direction = Facing::EAST;
            }
 
            if($downNonSolid && $diffY < $limit){
                $limit = $diffY;
                $direction = Facing::DOWN;
            }
 
            if($upNonSolid && 1 - $diffY < $limit){
                $limit = 1 - $diffY;
                $direction = Facing::UP;
            }
 
            if($northNonSolid && $diffZ < $limit){
                $limit = $diffZ;
                $direction = Facing::NORTH;
            }
 
            if($southNonSolid && 1 - $diffZ < $limit){
                $direction = Facing::SOUTH;
            }
 
            if($direction === -1){
                return false;
            }
 
            $force = Utils::getRandomFloat() * 0.2 + 0.1;
 
            $this->motion = match($direction){
                Facing::WEST => $this->motion->withComponents(-$force, null, null),
                Facing::EAST => $this->motion->withComponents($force, null, null),
                Facing::DOWN => $this->motion->withComponents(null, -$force, null),
                Facing::UP => $this->motion->withComponents(null, $force, null),
                Facing::NORTH => $this->motion->withComponents(null, null, -$force),
                Facing::SOUTH => $this->motion->withComponents(null, null, $force),
            };
            return true;
        }
 
        return false;
    }
 
    public function getHorizontalFacing() : int{
        $angle = fmod($this->location->yaw, 360);
        if($angle < 0){
            $angle += 360.0;
        }
 
        if((0 <= $angle && $angle < 45) || (315 <= $angle && $angle < 360)){
            return Facing::SOUTH;
        }
        if(45 <= $angle && $angle < 135){
            return Facing::WEST;
        }
        if(135 <= $angle && $angle < 225){
            return Facing::NORTH;
        }
 
        return Facing::EAST;
    }
 
    public function getDirectionVector() : Vector3{
        $y = -sin(deg2rad($this->location->pitch));
        $xz = cos(deg2rad($this->location->pitch));
        $x = -$xz * sin(deg2rad($this->location->yaw));
        $z = $xz * cos(deg2rad($this->location->yaw));
 
        return (new Vector3($x, $y, $z))->normalize();
    }
 
    public function getDirectionPlane() : Vector2{
        return (new Vector2(-cos(deg2rad($this->location->yaw) - M_PI_2), -sin(deg2rad($this->location->yaw) - M_PI_2)))->normalize();
    }
 
    protected function onFirstUpdate(int $currentTick) : void{
        (new EntitySpawnEvent($this))->call();
    }
 
    public function onUpdate(int $currentTick) : bool{
        if($this->closed){
            return false;
        }
 
        $tickDiff = $currentTick - $this->lastUpdate;
        if($tickDiff <= 0){
            if(!$this->justCreated){
                $this->server->getLogger()->debug("Expected tick difference of at least 1, got $tickDiff for " . get_class($this));
            }
 
            return true;
        }
 
        $this->lastUpdate = $currentTick;
 
        if($this->justCreated){
            $this->onFirstUpdate($currentTick);
        }
 
        if(!$this->isAlive()){
            if($this->onDeathUpdate($tickDiff)){
                $this->flagForDespawn();
            }
 
            return true;
        }
 
        $this->timings->startTiming();
 
        if($this->hasMovementUpdate()){
            $this->tryChangeMovement();
 
            $this->motion = $this->motion->withComponents(
                abs($this->motion->x) <= self::MOTION_THRESHOLD ? 0 : null,
                abs($this->motion->y) <= self::MOTION_THRESHOLD ? 0 : null,
                abs($this->motion->z) <= self::MOTION_THRESHOLD ? 0 : null
            );
 
            if($this->motion->x != 0 || $this->motion->y != 0 || $this->motion->z != 0){
                $this->move($this->motion->x, $this->motion->y, $this->motion->z);
            }
 
            $this->forceMovementUpdate = false;
        }
 
        $this->updateMovement();
 
        Timings::$entityBaseTick->startTiming();
        $hasUpdate = $this->entityBaseTick($tickDiff);
        Timings::$entityBaseTick->stopTiming();
 
        $this->timings->stopTiming();
 
        return ($hasUpdate || $this->hasMovementUpdate());
    }
 
    final public function scheduleUpdate() : void{
        if($this->closed){
            throw new \LogicException("Cannot schedule update on garbage entity " . get_class($this));
        }
        $this->getWorld()->updateEntities[$this->id] = $this;
    }
 
    public function onNearbyBlockChange() : void{
        $this->setForceMovementUpdate();
        $this->scheduleUpdate();
    }
 
    public function onRandomUpdate() : void{
        $this->scheduleUpdate();
    }
 
    final public function setForceMovementUpdate(bool $value = true) : void{
        $this->forceMovementUpdate = $value;
 
        $this->blocksAround = null;
    }
 
    public function hasMovementUpdate() : bool{
        return (
            $this->forceMovementUpdate ||
            $this->motion->x != 0 ||
            $this->motion->y != 0 ||
            $this->motion->z != 0 ||
            !$this->onGround
        );
    }
 
    public function getFallDistance() : float{ return $this->fallDistance; }
 
    public function setFallDistance(float $fallDistance) : void{
        $this->fallDistance = $fallDistance;
    }
 
    public function resetFallDistance() : void{
        $this->fallDistance = 0.0;
    }
 
    protected function updateFallState(float $distanceThisTick, bool $onGround) : ?float{
        if($distanceThisTick < $this->fallDistance){
            //we've fallen some distance (distanceThisTick is negative)
            //or we ascended back towards where fall distance was measured from initially (distanceThisTick is positive but less than existing fallDistance)
            $this->fallDistance -= $distanceThisTick;
        }else{
            //we ascended past the apex where fall distance was originally being measured from
            //reset it so it will be measured starting from the new, higher position
            $this->fallDistance = 0;
        }
        if($onGround && $this->fallDistance > 0){
            $newVerticalVelocity = $this->onHitGround();
            $this->resetFallDistance();
            return $newVerticalVelocity;
        }
        return null;
    }
 
    protected function onHitGround() : ?float{
        return null;
    }
 
    public function getEyeHeight() : float{
        return $this->size->getEyeHeight();
    }
 
    public function getEyePos() : Vector3{
        return new Vector3($this->location->x, $this->location->y + $this->getEyeHeight(), $this->location->z);
    }
 
    public function onCollideWithPlayer(Player $player) : void{
 
    }
 
    public function onInteract(Player $player, Vector3 $clickPos) : bool{
        return false;
    }
 
    public function isUnderwater() : bool{
        $block = $this->getWorld()->getBlockAt((int) floor($this->location->x), $blockY = (int) floor($y = ($this->location->y + $this->getEyeHeight())), (int) floor($this->location->z));
 
        if($block instanceof Water){
            $f = ($blockY + 1) - ($block->getFluidHeightPercent() - 0.1111111);
            return $y < $f;
        }
 
        return false;
    }
 
    public function isInsideOfSolid() : bool{
        $block = $this->getWorld()->getBlockAt((int) floor($this->location->x), (int) floor($y = ($this->location->y + $this->getEyeHeight())), (int) floor($this->location->z));
 
        return $block->isSolid() && !$block->isTransparent() && $block->collidesWithBB($this->getBoundingBox());
    }
 
    protected function move(float $dx, float $dy, float $dz) : void{
        $this->blocksAround = null;
 
        Timings::$entityMove->startTiming();
        Timings::$entityMoveCollision->startTiming();
 
        $wantedX = $dx;
        $wantedY = $dy;
        $wantedZ = $dz;
 
        if($this->keepMovement){
            $this->boundingBox->offset($dx, $dy, $dz);
        }else{
            $this->ySize *= self::STEP_CLIP_MULTIPLIER;
 
            $moveBB = clone $this->boundingBox;
 
            assert(abs($dx) <= 20 && abs($dy) <= 20 && abs($dz) <= 20, "Movement distance is excessive: dx=$dx, dy=$dy, dz=$dz");
 
            $list = $this->getWorld()->getBlockCollisionBoxes($moveBB->addCoord($dx, $dy, $dz));
 
            foreach($list as $bb){
                $dy = $bb->calculateYOffset($moveBB, $dy);
            }
 
            $moveBB->offset(0, $dy, 0);
 
            $fallingFlag = ($this->onGround || ($dy != $wantedY && $wantedY < 0));
 
            foreach($list as $bb){
                $dx = $bb->calculateXOffset($moveBB, $dx);
            }
 
            $moveBB->offset($dx, 0, 0);
 
            foreach($list as $bb){
                $dz = $bb->calculateZOffset($moveBB, $dz);
            }
 
            $moveBB->offset(0, 0, $dz);
 
            if($this->stepHeight > 0 && $fallingFlag && ($wantedX != $dx || $wantedZ != $dz)){
                $cx = $dx;
                $cy = $dy;
                $cz = $dz;
                $dx = $wantedX;
                $dy = $this->stepHeight;
                $dz = $wantedZ;
 
                $stepBB = clone $this->boundingBox;
 
                $list = $this->getWorld()->getBlockCollisionBoxes($stepBB->addCoord($dx, $dy, $dz));
                foreach($list as $bb){
                    $dy = $bb->calculateYOffset($stepBB, $dy);
                }
 
                $stepBB->offset(0, $dy, 0);
 
                foreach($list as $bb){
                    $dx = $bb->calculateXOffset($stepBB, $dx);
                }
 
                $stepBB->offset($dx, 0, 0);
 
                foreach($list as $bb){
                    $dz = $bb->calculateZOffset($stepBB, $dz);
                }
 
                $stepBB->offset(0, 0, $dz);
 
                $reverseDY = -$dy;
                foreach($list as $bb){
                    $reverseDY = $bb->calculateYOffset($stepBB, $reverseDY);
                }
                $dy += $reverseDY;
                $stepBB->offset(0, $reverseDY, 0);
 
                if(($cx ** 2 + $cz ** 2) >= ($dx ** 2 + $dz ** 2)){
                    $dx = $cx;
                    $dy = $cy;
                    $dz = $cz;
                }else{
                    $moveBB = $stepBB;
                    $this->ySize += $dy;
                }
            }
 
            $this->boundingBox = $moveBB;
        }
        Timings::$entityMoveCollision->stopTiming();
 
        $this->location = new Location(
            ($this->boundingBox->minX + $this->boundingBox->maxX) / 2,
            $this->boundingBox->minY - $this->ySize,
            ($this->boundingBox->minZ + $this->boundingBox->maxZ) / 2,
            $this->location->world,
            $this->location->yaw,
            $this->location->pitch
        );
 
        $this->getWorld()->onEntityMoved($this);
        $this->checkBlockIntersections();
        $this->checkGroundState($wantedX, $wantedY, $wantedZ, $dx, $dy, $dz);
        $postFallVerticalVelocity = $this->updateFallState($dy, $this->onGround);
 
        $this->motion = $this->motion->withComponents(
            $wantedX != $dx ? 0 : null,
            $postFallVerticalVelocity ?? ($wantedY != $dy ? 0 : null),
            $wantedZ != $dz ? 0 : null
        );
 
        //TODO: vehicle collision events (first we need to spawn them!)
 
        Timings::$entityMove->stopTiming();
    }
 
    protected function checkGroundState(float $wantedX, float $wantedY, float $wantedZ, float $dx, float $dy, float $dz) : void{
        $this->isCollidedVertically = $wantedY != $dy;
        $this->isCollidedHorizontally = ($wantedX != $dx || $wantedZ != $dz);
        $this->isCollided = ($this->isCollidedHorizontally || $this->isCollidedVertically);
        $this->onGround = ($wantedY != $dy && $wantedY < 0);
    }
 
    protected function getBlocksIntersected(float $inset) : \Generator{
        $minX = (int) floor($this->boundingBox->minX + $inset);
        $minY = (int) floor($this->boundingBox->minY + $inset);
        $minZ = (int) floor($this->boundingBox->minZ + $inset);
        $maxX = (int) floor($this->boundingBox->maxX - $inset);
        $maxY = (int) floor($this->boundingBox->maxY - $inset);
        $maxZ = (int) floor($this->boundingBox->maxZ - $inset);
 
        $world = $this->getWorld();
 
        for($z = $minZ; $z <= $maxZ; ++$z){
            for($x = $minX; $x <= $maxX; ++$x){
                for($y = $minY; $y <= $maxY; ++$y){
                    yield $world->getBlockAt($x, $y, $z);
                }
            }
        }
    }
 
    protected function getBlocksAroundWithEntityInsideActions() : array{
        if($this->blocksAround === null){
            $this->blocksAround = [];
 
            $inset = 0.001; //Offset against floating-point errors
            foreach($this->getBlocksIntersected($inset) as $block){
                if($block->hasEntityCollision()){
                    $this->blocksAround[] = $block;
                }
            }
        }
 
        return $this->blocksAround;
    }
 
    public function canBeMovedByCurrents() : bool{
        return true;
    }
 
    protected function checkBlockIntersections() : void{
        $this->checkBlockIntersectionsNextTick = false;
        $vectors = [];
 
        foreach($this->getBlocksAroundWithEntityInsideActions() as $block){
            if(!$block->onEntityInside($this)){
                $this->blocksAround = null;
            }
            if(($v = $block->addVelocityToEntity($this)) !== null){
                $vectors[] = $v;
            }
        }
 
        if(count($vectors) > 0){
            $vector = Vector3::sum(...$vectors);
            if($vector->lengthSquared() > 0){
                $d = 0.014;
                $this->motion = $this->motion->addVector($vector->normalize()->multiply($d));
            }
        }
    }
 
    public function getPosition() : Position{
        return $this->location->asPosition();
    }
 
    public function getLocation() : Location{
        return $this->location->asLocation();
    }
 
    public function getWorld() : World{
        return $this->location->getWorld();
    }
 
    protected function setPosition(Vector3 $pos) : bool{
        if($this->closed){
            return false;
        }
 
        $oldWorld = $this->getWorld();
        $newWorld = $pos instanceof Position ? $pos->getWorld() : $oldWorld;
        if($oldWorld !== $newWorld){
            $this->despawnFromAll();
            $oldWorld->removeEntity($this);
        }
 
        $this->location = Location::fromObject(
            $pos,
            $newWorld,
            $this->location->yaw,
            $this->location->pitch
        );
 
        $this->recalculateBoundingBox();
 
        $this->blocksAround = null;
 
        if($oldWorld !== $newWorld){
            $newWorld->addEntity($this);
        }else{
            $newWorld->onEntityMoved($this);
        }
 
        return true;
    }
 
    public function setRotation(float $yaw, float $pitch) : void{
        Utils::checkFloatNotInfOrNaN("yaw", $yaw);
        Utils::checkFloatNotInfOrNaN("pitch", $pitch);
        $this->location->yaw = $yaw;
        $this->location->pitch = $pitch;
        $this->scheduleUpdate();
    }
 
    protected function setPositionAndRotation(Vector3 $pos, float $yaw, float $pitch) : bool{
        if($this->setPosition($pos)){
            $this->setRotation($yaw, $pitch);
 
            return true;
        }
 
        return false;
    }
 
    protected function resetLastMovements() : void{
        $this->lastLocation = $this->location->asLocation();
        $this->lastMotion = clone $this->motion;
    }
 
    public function getMotion() : Vector3{
        return clone $this->motion;
    }
 
    public function setMotion(Vector3 $motion) : bool{
        Utils::checkVector3NotInfOrNaN($motion);
        if(!$this->justCreated){
            $ev = new EntityMotionEvent($this, $motion);
            $ev->call();
            if($ev->isCancelled()){
                return false;
            }
        }
 
        $this->motion = clone $motion;
 
        if(!$this->justCreated){
            $this->updateMovement();
        }
 
        return true;
    }
 
    public function addMotion(float $x, float $y, float $z) : void{
        Utils::checkFloatNotInfOrNaN("x", $x);
        Utils::checkFloatNotInfOrNaN("y", $y);
        Utils::checkFloatNotInfOrNaN("z", $z);
        $this->motion = $this->motion->add($x, $y, $z);
    }
 
    public function isOnGround() : bool{
        return $this->onGround;
    }
 
    public function teleport(Vector3 $pos, ?float $yaw = null, ?float $pitch = null) : bool{
        Utils::checkVector3NotInfOrNaN($pos);
        if($pos instanceof Location){
            $yaw = $yaw ?? $pos->yaw;
            $pitch = $pitch ?? $pos->pitch;
        }
        if($yaw !== null){
            Utils::checkFloatNotInfOrNaN("yaw", $yaw);
        }
        if($pitch !== null){
            Utils::checkFloatNotInfOrNaN("pitch", $pitch);
        }
 
        $from = $this->location->asPosition();
        $to = Position::fromObject($pos, $pos instanceof Position ? $pos->getWorld() : $this->getWorld());
        $ev = new EntityTeleportEvent($this, $from, $to);
        $ev->call();
        if($ev->isCancelled()){
            return false;
        }
        $this->ySize = 0;
        $pos = $ev->getTo();
 
        $this->setMotion(new Vector3(0, 0, 0));
        if($this->setPositionAndRotation($pos, $yaw ?? $this->location->yaw, $pitch ?? $this->location->pitch)){
            $this->resetFallDistance();
            $this->setForceMovementUpdate();
 
            $this->updateMovement(true);
 
            return true;
        }
 
        return false;
    }
 
    public function getId() : int{
        return $this->id;
    }
 
    public function getViewers() : array{
        return $this->hasSpawned;
    }
 
    abstract public static function getNetworkTypeId() : string;
 
    protected function sendSpawnPacket(Player $player) : void{
        $player->getNetworkSession()->sendDataPacket(AddActorPacket::create(
            $this->getId(), //TODO: actor unique ID
            $this->getId(),
            static::getNetworkTypeId(),
            $this->location->asVector3(),
            $this->getMotion(),
            $this->location->pitch,
            $this->location->yaw,
            $this->location->yaw, //TODO: head yaw
            $this->location->yaw, //TODO: body yaw (wtf mojang?)
            array_map(function(Attribute $attr) : NetworkAttribute{
                return new NetworkAttribute($attr->getId(), $attr->getMinValue(), $attr->getMaxValue(), $attr->getValue(), $attr->getDefaultValue(), []);
            }, $this->attributeMap->getAll()),
            $this->getAllNetworkData(),
            new PropertySyncData([], []),
            [] //TODO: entity links
        ));
    }
 
    public function spawnTo(Player $player) : void{
        $id = spl_object_id($player);
        //TODO: this will cause some visible lag during chunk resends; if the player uses a spawn egg in a chunk, the
        //created entity won't be visible until after the resend arrives. However, this is better than possibly crashing
        //the player by sending them entities too early.
        if(!isset($this->hasSpawned[$id]) && $player->getWorld() === $this->getWorld() && $player->hasReceivedChunk($this->location->getFloorX() >> Chunk::COORD_BIT_SIZE, $this->location->getFloorZ() >> Chunk::COORD_BIT_SIZE)){
            $this->hasSpawned[$id] = $player;
 
            $this->sendSpawnPacket($player);
        }
    }
 
    public function spawnToAll() : void{
        if($this->closed){
            return;
        }
        foreach($this->getWorld()->getViewersForPosition($this->location) as $player){
            $this->spawnTo($player);
        }
    }
 
    public function respawnToAll() : void{
        foreach($this->hasSpawned as $key => $player){
            unset($this->hasSpawned[$key]);
            $this->spawnTo($player);
        }
    }
 
    public function despawnFrom(Player $player, bool $send = true) : void{
        $id = spl_object_id($player);
        if(isset($this->hasSpawned[$id])){
            if($send){
                $player->getNetworkSession()->getEntityEventBroadcaster()->onEntityRemoved([$player->getNetworkSession()], $this);
            }
            unset($this->hasSpawned[$id]);
        }
    }
 
    public function despawnFromAll() : void{
        NetworkBroadcastUtils::broadcastEntityEvent(
            $this->hasSpawned,
            fn(EntityEventBroadcaster $broadcaster, array $recipients) => $broadcaster->onEntityRemoved($recipients, $this)
        );
        $this->hasSpawned = [];
    }
 
    public function getPickedItem() : ?Item{
        return null;
    }
 
    public function flagForDespawn() : void{
        $this->needsDespawn = true;
        $this->scheduleUpdate();
    }
 
    public function isFlaggedForDespawn() : bool{
        return $this->needsDespawn;
    }
 
    public function isClosed() : bool{
        return $this->closed;
    }
 
    final public function close() : void{
        if($this->closeInFlight){
            return;
        }
 
        if(!$this->closed){
            $this->closeInFlight = true;
            (new EntityDespawnEvent($this))->call();
 
            $this->onDispose();
            $this->closed = true;
            $this->destroyCycles();
            $this->closeInFlight = false;
        }
    }
 
    protected function onDispose() : void{
        $this->despawnFromAll();
        if($this->location->isValid()){
            $this->getWorld()->removeEntity($this);
        }
    }
 
    protected function destroyCycles() : void{
        $this->lastDamageCause = null;
    }
 
    public function sendData(?array $targets, ?array $data = null) : void{
        $targets = $targets ?? $this->hasSpawned;
        $data = $data ?? $this->getAllNetworkData();
 
        NetworkBroadcastUtils::broadcastEntityEvent($targets, fn(EntityEventBroadcaster $broadcaster, array $recipients) => $broadcaster->syncActorData($recipients, $this, $data));
    }
 
    final protected function getDirtyNetworkData() : array{
        if($this->networkPropertiesDirty){
            $this->syncNetworkData($this->networkProperties);
            $this->networkPropertiesDirty = false;
        }
        return $this->networkProperties->getDirty();
    }
 
    final protected function getAllNetworkData() : array{
        if($this->networkPropertiesDirty){
            $this->syncNetworkData($this->networkProperties);
            $this->networkPropertiesDirty = false;
        }
        return $this->networkProperties->getAll();
    }
 
    protected function syncNetworkData(EntityMetadataCollection $properties) : void{
        $properties->setByte(EntityMetadataProperties::ALWAYS_SHOW_NAMETAG, $this->alwaysShowNameTag ? 1 : 0);
        $properties->setFloat(EntityMetadataProperties::BOUNDING_BOX_HEIGHT, $this->size->getHeight() / $this->scale);
        $properties->setFloat(EntityMetadataProperties::BOUNDING_BOX_WIDTH, $this->size->getWidth() / $this->scale);
        $properties->setFloat(EntityMetadataProperties::SCALE, $this->scale);
        $properties->setLong(EntityMetadataProperties::LEAD_HOLDER_EID, -1);
        $properties->setLong(EntityMetadataProperties::OWNER_EID, $this->ownerId ?? -1);
        $properties->setLong(EntityMetadataProperties::TARGET_EID, $this->targetId ?? 0);
        $properties->setString(EntityMetadataProperties::NAMETAG, $this->nameTag);
        $properties->setString(EntityMetadataProperties::SCORE_TAG, $this->scoreTag);
        $properties->setByte(EntityMetadataProperties::COLOR, 0);
 
        $properties->setGenericFlag(EntityMetadataFlags::AFFECTED_BY_GRAVITY, $this->gravityEnabled);
        $properties->setGenericFlag(EntityMetadataFlags::CAN_CLIMB, $this->canClimb);
        $properties->setGenericFlag(EntityMetadataFlags::CAN_SHOW_NAMETAG, $this->nameTagVisible);
        $properties->setGenericFlag(EntityMetadataFlags::HAS_COLLISION, true);
        $properties->setGenericFlag(EntityMetadataFlags::NO_AI, $this->noClientPredictions);
        $properties->setGenericFlag(EntityMetadataFlags::INVISIBLE, $this->invisible);
        $properties->setGenericFlag(EntityMetadataFlags::SILENT, $this->silent);
        $properties->setGenericFlag(EntityMetadataFlags::ONFIRE, $this->isOnFire());
        $properties->setGenericFlag(EntityMetadataFlags::WALLCLIMBING, $this->canClimbWalls);
    }
 
    public function broadcastAnimation(Animation $animation, ?array $targets = null) : void{
        NetworkBroadcastUtils::broadcastPackets($targets ?? $this->getViewers(), $animation->encode());
    }
 
    public function broadcastSound(Sound $sound, ?array $targets = null) : void{
        if(!$this->silent){
            $this->getWorld()->addSound($this->location->asVector3(), $sound, $targets ?? $this->getViewers());
        }
    }
 
    public function __destruct(){
        $this->close();
    }
 
    public function __toString(){
        return (new \ReflectionClass($this))->getShortName() . "(" . $this->getId() . ")";
    }
}