FallingBlock.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\object;
 
use pocketmine\block\Block;
use pocketmine\block\RuntimeBlockStateRegistry;
use pocketmine\block\utils\Fallable;
use pocketmine\data\bedrock\block\BlockStateDeserializeException;
use pocketmine\data\SavedDataLoadingException;
use pocketmine\entity\Entity;
use pocketmine\entity\EntitySizeInfo;
use pocketmine\entity\Living;
use pocketmine\entity\Location;
use pocketmine\event\entity\EntityBlockChangeEvent;
use pocketmine\event\entity\EntityDamageByEntityEvent;
use pocketmine\event\entity\EntityDamageEvent;
use pocketmine\math\Vector3;
use pocketmine\nbt\tag\ByteTag;
use pocketmine\nbt\tag\CompoundTag;
use pocketmine\nbt\tag\IntTag;
use pocketmine\network\mcpe\convert\TypeConverter;
use pocketmine\network\mcpe\protocol\types\entity\EntityIds;
use pocketmine\network\mcpe\protocol\types\entity\EntityMetadataCollection;
use pocketmine\network\mcpe\protocol\types\entity\EntityMetadataProperties;
use pocketmine\world\format\io\GlobalBlockStateHandlers;
use pocketmine\world\sound\BlockBreakSound;
use function abs;
use function min;
use function round;
 
class FallingBlock extends Entity{
    private const TAG_FALLING_BLOCK = "FallingBlock"; //TAG_Compound
    private const TAG_TILE_ID = "TileID"; //TAG_Int
    private const TAG_TILE = "Tile"; //TAG_Byte
    private const TAG_DATA = "Data"; //TAG_Byte
 
    public static function getNetworkTypeId() : string{ return EntityIds::FALLING_BLOCK; }
 
    protected Block $block;
 
    public function __construct(Location $location, Block $block, ?CompoundTag $nbt = null){
        $this->block = $block;
        parent::__construct($location, $nbt);
    }
 
    protected function getInitialSizeInfo() : EntitySizeInfo{ return new EntitySizeInfo(0.98, 0.98); }
 
    protected function getInitialDragMultiplier() : float{ return 0.02; }
 
    protected function getInitialGravity() : float{ return 0.04; }
 
    public static function parseBlockNBT(RuntimeBlockStateRegistry $factory, CompoundTag $nbt) : Block{
 
        //TODO: 1.8+ save format
        $blockDataUpgrader = GlobalBlockStateHandlers::getUpgrader();
        if(($fallingBlockTag = $nbt->getCompoundTag(self::TAG_FALLING_BLOCK)) !== null){
            try{
                $blockStateData = $blockDataUpgrader->upgradeBlockStateNbt($fallingBlockTag);
            }catch(BlockStateDeserializeException $e){
                throw new SavedDataLoadingException("Invalid falling block blockstate: " . $e->getMessage(), 0, $e);
            }
        }else{
            if(($tileIdTag = $nbt->getTag(self::TAG_TILE_ID)) instanceof IntTag){
                $blockId = $tileIdTag->getValue();
            }elseif(($tileTag = $nbt->getTag(self::TAG_TILE)) instanceof ByteTag){
                $blockId = $tileTag->getValue();
            }else{
                throw new SavedDataLoadingException("Missing legacy falling block info");
            }
            $damage = $nbt->getByte(self::TAG_DATA, 0);
 
            try{
                $blockStateData = $blockDataUpgrader->upgradeIntIdMeta($blockId, $damage);
            }catch(BlockStateDeserializeException $e){
                throw new SavedDataLoadingException("Invalid legacy falling block data: " . $e->getMessage(), 0, $e);
            }
        }
 
        try{
            $blockStateId = GlobalBlockStateHandlers::getDeserializer()->deserialize($blockStateData);
        }catch(BlockStateDeserializeException $e){
            throw new SavedDataLoadingException($e->getMessage(), 0, $e);
        }
 
        return $factory->fromStateId($blockStateId);
    }
 
    public function canCollideWith(Entity $entity) : bool{
        return false;
    }
 
    public function canBeMovedByCurrents() : bool{
        return false;
    }
 
    public function attack(EntityDamageEvent $source) : void{
        if($source->getCause() === EntityDamageEvent::CAUSE_VOID){
            parent::attack($source);
        }
    }
 
    protected function entityBaseTick(int $tickDiff = 1) : bool{
        if($this->closed){
            return false;
        }
 
        $hasUpdate = parent::entityBaseTick($tickDiff);
 
        if(!$this->isFlaggedForDespawn()){
            $world = $this->getWorld();
            $pos = $this->location->add(-$this->size->getWidth() / 2, $this->size->getHeight(), -$this->size->getWidth() / 2)->floor();
 
            $this->block->position($world, $pos->x, $pos->y, $pos->z);
 
            $blockTarget = null;
            if($this->block instanceof Fallable){
                $blockTarget = $this->block->tickFalling();
            }
 
            if($this->onGround || $blockTarget !== null){
                $this->flagForDespawn();
 
                $blockResult = $blockTarget ?? $this->block;
                $block = $world->getBlock($pos);
                if(!$block->canBeReplaced() || !$world->isInWorld($pos->getFloorX(), $pos->getFloorY(), $pos->getFloorZ()) || ($this->onGround && abs($this->location->y - $this->location->getFloorY()) > 0.001)){
                    $world->dropItem($this->location, $this->block->asItem());
                    $world->addSound($pos->add(0.5, 0.5, 0.5), new BlockBreakSound($blockResult));
                }else{
                    $ev = new EntityBlockChangeEvent($this, $block, $blockResult);
                    $ev->call();
                    if(!$ev->isCancelled()){
                        $b = $ev->getTo();
                        $world->setBlock($pos, $b);
                        if($this->onGround && $b instanceof Fallable && ($sound = $b->getLandSound()) !== null){
                            $world->addSound($pos->add(0.5, 0.5, 0.5), $sound);
                        }
                    }
                }
                $hasUpdate = true;
            }
        }
 
        return $hasUpdate;
    }
 
    protected function onHitGround() : ?float{
        if($this->block instanceof Fallable){
            $damagePerBlock = $this->block->getFallDamagePerBlock();
            if($damagePerBlock > 0 && ($fallenBlocks = round($this->fallDistance) - 1) > 0){
                $damage = min($fallenBlocks * $damagePerBlock, $this->block->getMaxFallDamage());
                foreach($this->getWorld()->getCollidingEntities($this->getBoundingBox()) as $entity){
                    if($entity instanceof Living){
                        $ev = new EntityDamageByEntityEvent($this, $entity, EntityDamageEvent::CAUSE_FALLING_BLOCK, $damage);
                        $entity->attack($ev);
                    }
                }
            }
            if(!$this->block->onHitGround($this)){
                $this->flagForDespawn();
            }
        }
        return null;
    }
 
    public function getBlock() : Block{
        return $this->block;
    }
 
    public function saveNBT() : CompoundTag{
        $nbt = parent::saveNBT();
        $nbt->setTag(self::TAG_FALLING_BLOCK, GlobalBlockStateHandlers::getSerializer()->serialize($this->block->getStateId())->toNbt());
 
        return $nbt;
    }
 
    protected function syncNetworkData(EntityMetadataCollection $properties) : void{
        parent::syncNetworkData($properties);
 
        $properties->setInt(EntityMetadataProperties::VARIANT, TypeConverter::getInstance()->getBlockTranslator()->internalIdToNetworkId($this->block->getStateId()));
    }
 
    public function getOffsetPosition(Vector3 $vector3) : Vector3{
        return $vector3->add(0, 0.49, 0); //TODO: check if height affects this
    }
}