pocketmine\utils\VectorIterator::__construct PHP Method

    public function __construct(ChunkManager $level, Vector3 $from, Vector3 $to)
    {
        if ($from->equals($to)) {
            $this->end = true;
            $this->currentBlock = -1;
            return;
        }
        $direction = $to->subtract($from)->normalize();
        $maxDistance = $from->distance($to);
        $this->level = $level;
        $this->maxDistance = (int) $maxDistance;
        $this->positionQueue = new \SplFixedArray(3);
        $startClone = new Vector3($from->x, $from->y, $from->z);
        $this->currentDistance = 0;
        $mainDirection = 0;
        $secondDirection = 0;
        $thirdDirection = 0;
        $mainPosition = 0;
        $secondPosition = 0;
        $thirdPosition = 0;
        $pos = new Vector3($startClone->x, $startClone->y, $startClone->z);
        $startBlock = new Vector3(floor($pos->x), floor($pos->y), floor($pos->z));
        if ($this->getXLength($direction) > $mainDirection) {
            $this->mainFace = $this->getXFace($direction);
            $mainDirection = $this->getXLength($direction);
            $mainPosition = $this->getXPosition($direction, $startClone, $startBlock);
            $this->secondFace = $this->getYFace($direction);
            $secondDirection = $this->getYLength($direction);
            $secondPosition = $this->getYPosition($direction, $startClone, $startBlock);
            $this->thirdFace = $this->getZFace($direction);
            $thirdDirection = $this->getZLength($direction);
            $thirdPosition = $this->getZPosition($direction, $startClone, $startBlock);
        }
        if ($this->getYLength($direction) > $mainDirection) {
            $this->mainFace = $this->getYFace($direction);
            $mainDirection = $this->getYLength($direction);
            $mainPosition = $this->getYPosition($direction, $startClone, $startBlock);
            $this->secondFace = $this->getZFace($direction);
            $secondDirection = $this->getZLength($direction);
            $secondPosition = $this->getZPosition($direction, $startClone, $startBlock);
            $this->thirdFace = $this->getXFace($direction);
            $thirdDirection = $this->getXLength($direction);
            $thirdPosition = $this->getXPosition($direction, $startClone, $startBlock);
        }
        if ($this->getZLength($direction) > $mainDirection) {
            $this->mainFace = $this->getZFace($direction);
            $mainDirection = $this->getZLength($direction);
            $mainPosition = $this->getZPosition($direction, $startClone, $startBlock);
            $this->secondFace = $this->getXFace($direction);
            $secondDirection = $this->getXLength($direction);
            $secondPosition = $this->getXPosition($direction, $startClone, $startBlock);
            $this->thirdFace = $this->getYFace($direction);
            $thirdDirection = $this->getYLength($direction);
            $thirdPosition = $this->getYPosition($direction, $startClone, $startBlock);
        }
        $d = $mainPosition / $mainDirection;
        $secondd = $secondPosition - $secondDirection * $d;
        $thirdd = $thirdPosition - $thirdDirection * $d;
        $this->secondError = floor($secondd * self::$gridSize);
        $this->secondStep = round($secondDirection / $mainDirection * self::$gridSize);
        $this->thirdError = floor($thirdd * self::$gridSize);
        $this->thirdStep = round($thirdDirection / $mainDirection * self::$gridSize);
        if ($this->secondError + $this->secondStep <= 0) {
            $this->secondError = -$this->secondStep + 1;
        }
        if ($this->thirdError + $this->thirdStep <= 0) {
            $this->thirdError = -$this->thirdStep + 1;
        }
        $lastBlock = $startBlock->getSide(Vector3::getOppositeSide($this->mainFace));
        if ($this->secondError < 0) {
            $this->secondError += self::$gridSize;
            $lastBlock = $lastBlock->getSide(Vector3::getOppositeSide($this->secondFace));
        }
        if ($this->thirdError < 0) {
            $this->thirdError += self::$gridSize;
            $lastBlock = $lastBlock->getSide(Vector3::getOppositeSide($this->thirdFace));
        }
        $this->secondError -= self::$gridSize;
        $this->thirdError -= self::$gridSize;
        $this->positionQueue[0] = $lastBlock;
        $this->currentBlock = -1;
        $this->scan();
        $startBlockFound = false;
        for ($cnt = $this->currentBlock; $cnt >= 0; --$cnt) {
            if ($this->posEquals($this->positionQueue[$cnt], $startBlock)) {
                $this->currentBlock = $cnt;
                $startBlockFound = true;
                break;
            }
        }
        if (!$startBlockFound) {
            throw new \InvalidStateException("Start block missed in BlockIterator");
        }
        $this->maxDistanceInt = round($maxDistance / (sqrt($mainDirection ** 2 + $secondDirection ** 2 + $thirdDirection ** 2) / $mainDirection));
    }