RuntimeBlockStateRegistry.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\block;
 
use pocketmine\block\BlockBreakInfo as BreakInfo;
use pocketmine\block\BlockIdentifier as BID;
use pocketmine\utils\AssumptionFailedError;
use pocketmine\utils\SingletonTrait;
use pocketmine\world\light\LightUpdate;
use function count;
use function min;
 
class RuntimeBlockStateRegistry{
    use SingletonTrait;
 
    public const COLLISION_CUSTOM = 0;
    public const COLLISION_CUBE = 1;
    public const COLLISION_NONE = 2;
    public const COLLISION_MAY_OVERFLOW = 3;
 
    private array $fullList = [];
 
    private array $typeIndex = [];
 
    public array $light = [];
    public array $lightFilter = [];
    public array $blocksDirectSkyLight = [];
    public array $blastResistance = [];
 
    public array $collisionInfo = [];
 
    public function __construct(){
        foreach(VanillaBlocks::getAll() as $block){
            $this->register($block);
        }
    }
 
    public function register(Block $block) : void{
        $typeId = $block->getTypeId();
 
        if(isset($this->typeIndex[$typeId])){
            throw new \InvalidArgumentException("Block ID $typeId is already used by another block");
        }
 
        $this->typeIndex[$typeId] = clone $block;
 
        foreach($block->generateStatePermutations() as $v){
            $this->fillStaticArrays($v->getStateId(), $v);
        }
    }
 
    private static function overridesBlockMethod(\Closure $closure) : bool{
        $declarer = (new \ReflectionFunction($closure))->getClosureScopeClass();
        return $declarer !== null && $declarer->getName() !== Block::class;
    }
 
    private static function calculateCollisionInfo(Block $block) : int{
        if(
            self::overridesBlockMethod($block->getModelPositionOffset(...)) ||
            self::overridesBlockMethod($block->readStateFromWorld(...))
        ){
            //getModelPositionOffset() might cause AABBs to shift outside the cell
            //readStateFromWorld() might cause overflow in ways we can't predict just by looking at known states
            //TODO: excluding overriders of readStateFromWorld() also excludes blocks with tiles that don't do anything
            //weird with their AABBs, but for now this is the best we can do.
            return self::COLLISION_MAY_OVERFLOW;
        }
 
        //TODO: this could blow up if any recalculateCollisionBoxes() uses the world
        //it shouldn't, but that doesn't mean that custom blocks won't...
        $boxes = $block->getCollisionBoxes();
        if(count($boxes) === 0){
            return self::COLLISION_NONE;
        }
 
        if(
            count($boxes) === 1 &&
            $boxes[0]->minX === 0.0 &&
            $boxes[0]->minY === 0.0 &&
            $boxes[0]->minZ === 0.0 &&
            $boxes[0]->maxX === 1.0 &&
            $boxes[0]->maxY === 1.0 &&
            $boxes[0]->maxZ === 1.0
        ){
            return self::COLLISION_CUBE;
        }
 
        foreach($boxes as $box){
            if(
                $box->minX < 0 || $box->maxX > 1 ||
                $box->minY < 0 || $box->maxY > 1 ||
                $box->minZ < 0 || $box->maxZ > 1
            ){
                return self::COLLISION_MAY_OVERFLOW;
            }
        }
 
        return self::COLLISION_CUSTOM;
    }
 
    private function fillStaticArrays(int $index, Block $block) : void{
        $fullId = $block->getStateId();
        if($index !== $fullId){
            throw new AssumptionFailedError("Cannot fill static arrays for an invalid blockstate");
        }else{
            $this->fullList[$index] = $block;
            $this->blastResistance[$index] = $block->getBreakInfo()->getBlastResistance();
            $this->light[$index] = $block->getLightLevel();
            $this->lightFilter[$index] = min(15, $block->getLightFilter() + LightUpdate::BASE_LIGHT_FILTER);
            if($block->blocksDirectSkyLight()){
                $this->blocksDirectSkyLight[$index] = true;
            }
 
            $this->collisionInfo[$index] = self::calculateCollisionInfo($block);
        }
    }
 
    public function fromStateId(int $stateId) : Block{
        if($stateId < 0){
            throw new \InvalidArgumentException("Block state ID cannot be negative");
        }
        if(isset($this->fullList[$stateId])) { //hot
            $block = clone $this->fullList[$stateId];
        }else{
            $typeId = $stateId >> Block::INTERNAL_STATE_DATA_BITS;
            $stateData = ($stateId ^ $typeId) & Block::INTERNAL_STATE_DATA_MASK;
            $block = new UnknownBlock(new BID($typeId), new BlockTypeInfo(BreakInfo::instant()), $stateData);
        }
 
        return $block;
    }
 
    public function getAllKnownStates() : array{
        return $this->fullList;
    }
}