/src/pocketmine/level/Explosion.php

<?php
/**
 * src/pocketmine/level/Explosion.php
 *
 * @package default
 */


/*
 *
 *  _                       _           _ __  __ _
 * (_)                     (_)         | |  \/  (_)
 *  _ _ __ ___   __ _  __ _ _  ___ __ _| | \  / |_ _ __   ___
 * | | '_ ` _ \ / _` |/ _` | |/ __/ _` | | |\/| | | '_ \ / _ \
 * | | | | | | | (_| | (_| | | (_| (_| | | |  | | | | | |  __/
 * |_|_| |_| |_|\__,_|\__, |_|\___\__,_|_|_|  |_|_|_| |_|\___|
 *                     __/ |
 *                    |___/
 *
 * This program is a third party build by ImagicalMine.
 *
 * PocketMine 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 ImagicalMine Team
 * @link http://forums.imagicalcorp.ml/
 *
 *
*/

namespace pocketmine\level;

use pocketmine\block\Block;
use pocketmine\entity\Entity;
use pocketmine\event\entity\EntityDamageByBlockEvent;
use pocketmine\event\entity\EntityDamageByEntityEvent;
use pocketmine\event\entity\EntityDamageEvent;
use pocketmine\event\entity\EntityExplodeEvent;
use pocketmine\event\block\BlockUpdateEvent;
use pocketmine\item\Item;
use pocketmine\math\AxisAlignedBB;
use pocketmine\math\Math;
use pocketmine\math\Vector3;
use pocketmine\nbt\tag\ListTag;
use pocketmine\nbt\tag\DoubleTag;
use pocketmine\nbt\tag\FloatTag;
use pocketmine\nbt\tag\ByteTag;
use pocketmine\nbt\tag\CompoundTag;
use pocketmine\network\protocol\ExplodePacket;
use pocketmine\block\Redstone;
use pocketmine\block\RedstoneTools;
use pocketmine\utils\Random;

class Explosion
{

    private $rays = 16; //Rays
    public $level;
    public $source;
    public $size;

    /**
     *
     * @var Block[]
     */
    public $affectedBlocks = [];
    public $stepLen = 0.3;
    /** @var Entity|Block */
    private $what;

    /**
     *
     * @param Position $center
     * @param unknown  $size
     * @param unknown  $what   (optional)
     */
    public function __construct(Position $center, $size, $what = null)
    {
        $this->level = $center->getLevel();
        $this->source = $center;
        $this->size = max($size, 0);
        $this->what = $what;
    }


    /**
     *
     * @deprecated
     * @return bool
     */
    public function explode()
    {
        if ($this->explodeA()) {
            return $this->explodeB();
        }

        return false;
    }


    /**
     *
     * @return bool
     */
    public function explodeA()
    {
        if ($this->size < 0.1) {
            return false;
        }

        $vector = new Vector3(0, 0, 0);
        $vBlock = new Vector3(0, 0, 0);

        $mRays = intval($this->rays - 1);
        for ($i = 0; $i < $this->rays; ++$i) {
            for ($j = 0; $j < $this->rays; ++$j) {
                for ($k = 0; $k < $this->rays; ++$k) {
                    if ($i === 0 or $i === $mRays or $j === 0 or $j === $mRays or $k === 0 or $k === $mRays) {
                        $vector->setComponents($i / $mRays * 2 - 1, $j / $mRays * 2 - 1, $k / $mRays * 2 - 1);
                        $vector->setComponents(($vector->x / ($len = $vector->length())) * $this->stepLen, ($vector->y / $len) * $this->stepLen, ($vector->z / $len) * $this->stepLen);
                        $pointerX = $this->source->x;
                        $pointerY = $this->source->y;
                        $pointerZ = $this->source->z;

                        for ($blastForce = $this->size * (mt_rand(700, 1300) / 1000); $blastForce > 0; $blastForce -= $this->stepLen * 0.75) {
                            $x = (int) $pointerX;
                            $y = (int) $pointerY;
                            $z = (int) $pointerZ;
                            $vBlock->x = $pointerX >= $x ? $x : $x - 1;
                            $vBlock->y = $pointerY >= $y ? $y : $y - 1;
                            $vBlock->z = $pointerZ >= $z ? $z : $z - 1;
                            if ($vBlock->y < 0 or $vBlock->y > 127) {
                                break;
                            }
                            $block = $this->level->getBlock($vBlock);

                            if ($block->getId() !== 0) {
                                $blastForce -= ($block->getResistance() / 5 + 0.3) * $this->stepLen;
                                if ($blastForce > 0) {
                                    if (!isset($this->affectedBlocks[$index = Level::blockHash($block->x, $block->y, $block->z)])) {
                                        $this->affectedBlocks[$index] = $block;
                                    }
                                }
                            }
                            $pointerX += $vector->x;
                            $pointerY += $vector->y;
                            $pointerZ += $vector->z;
                        }
                    }
                }
            }
        }

        return true;
    }


    /**
     *
     * @return unknown
     */
    public function explodeB()
    {
        $send = [];
        $updateBlocks = [];

        $source = (new Vector3($this->source->x, $this->source->y, $this->source->z))->floor();
        $yield = (1 / $this->size) * 100;

        if ($this->what instanceof Entity) {
            $this->level->getServer()->getPluginManager()->callEvent($ev = new EntityExplodeEvent($this->what, $this->source, $this->affectedBlocks, $yield));
            if ($ev->isCancelled()) {
                return false;
            } else {
                $yield = $ev->getYield();
                $this->affectedBlocks = $ev->getBlockList();
            }
        }

        $explosionSize = $this->size * 2;
        $minX = Math::floorFloat($this->source->x - $explosionSize - 1);
        $maxX = Math::ceilFloat($this->source->x + $explosionSize + 1);
        $minY = Math::floorFloat($this->source->y - $explosionSize - 1);
        $maxY = Math::ceilFloat($this->source->y + $explosionSize + 1);
        $minZ = Math::floorFloat($this->source->z - $explosionSize - 1);
        $maxZ = Math::ceilFloat($this->source->z + $explosionSize + 1);

        $explosionBB = new AxisAlignedBB($minX, $minY, $minZ, $maxX, $maxY, $maxZ);

        $list = $this->level->getNearbyEntities($explosionBB, $this->what instanceof Entity ? $this->what : null);
        foreach ($list as $entity) {
            $distance = $entity->distance($this->source) / $explosionSize;

            if ($distance <= 1) {
                $motion = $entity->subtract($this->source)->normalize();

                $impact = (1 - $distance) * ($exposure = 1);

                $damage = (int) ((($impact * $impact + $impact) / 2) * 8 * $explosionSize + 1);

                if ($this->what instanceof Entity) {
                    $ev = new EntityDamageByEntityEvent($this->what, $entity, EntityDamageEvent::CAUSE_ENTITY_EXPLOSION, $damage);
                } elseif ($this->what instanceof Block) {
                    $ev = new EntityDamageByBlockEvent($this->what, $entity, EntityDamageEvent::CAUSE_BLOCK_EXPLOSION, $damage);
                } else {
                    $ev = new EntityDamageEvent($entity, EntityDamageEvent::CAUSE_BLOCK_EXPLOSION, $damage);
                }

                $entity->attack($ev->getFinalDamage(), $ev);
                $entity->setMotion($motion->multiply($impact));
            }
        }


        $air = Item::get(Item::AIR);

        foreach ($this->affectedBlocks as $block) {
            if ($block->getId() === Block::TNT) {
                $mot = (new Random())->nextSignedFloat() * M_PI * 2;
                $tnt = Entity::createEntity("PrimedTNT", $this->level->getChunk($block->x >> 4, $block->z >> 4), new CompoundTag("", [
                            "Pos" => new ListTag("Pos", [
                                    new DoubleTag("", $block->x + 0.5),
                                    new DoubleTag("", $block->y),
                                    new DoubleTag("", $block->z + 0.5)
                                ]),
                            "Motion" => new ListTag("Motion", [
                                    new DoubleTag("", -sin($mot) * 0.02),
                                    new DoubleTag("", 0.2),
                                    new DoubleTag("", -cos($mot) * 0.02)
                                ]),
                            "Rotation" => new ListTag("Rotation", [
                                    new FloatTag("", 0),
                                    new FloatTag("", 0)
                                ]),
                            "Fuse" => new ByteTag("Fuse", mt_rand(10, 30))
                        ]));
                $tnt->spawnToAll();
            } elseif (mt_rand(0, 100) < $yield) {
                foreach ($block->getDrops($air) as $drop) {
                    $this->level->dropItem($block->add(0.5, 0.5, 0.5), Item::get(...$drop));
                }
            }

            $this->level->setBlockIdAt($block->x, $block->y, $block->z, 0);

            $pos = new Vector3($block->x, $block->y, $block->z);

            for ($side = 0; $side < 5; $side++) {
                $sideBlock = $pos->getSide($side);
                if (!isset($this->affectedBlocks[$index = Level::blockHash($sideBlock->x, $sideBlock->y, $sideBlock->z)]) and !isset($updateBlocks[$index])) {
                    $this->level->getServer()->getPluginManager()->callEvent($ev = new BlockUpdateEvent($this->level->getBlock($sideBlock)));
                    if (!$ev->isCancelled()) {
                        $targetBlock=$ev->getBlock();
                        $targetBlock->onUpdate(Level::BLOCK_UPDATE_NORMAL);
                        if ($targetBlock instanceof Redstone) {
                            $targetBlock->onRedstoneUpdate(Level::REDSTONE_UPDATE_BREAK, 0);
                        }
                    }
                    $updateBlocks[$index] = true;
                }
            }
            $send[] = new Vector3($block->x - $source->x, $block->y - $source->y, $block->z - $source->z);
        }

        $pk = new ExplodePacket();
        $pk->x = $this->source->x;
        $pk->y = $this->source->y;
        $pk->z = $this->source->z;
        $pk->radius = $this->size;
        $pk->records = $send;
        $this->level->addChunkPacket($source->x >> 4, $source->z >> 4, $pk);

        return true;
    }
}