pocketmine\level\generator\object\BigTree::getAvailableBlockSpace PHP Метод

    private function getAvailableBlockSpace(ChunkManager $level, Vector3 $from, Vector3 $to)
    {
        $count = 0;
        $iter = new VectorIterator($level, $from, $to);
        while ($iter->valid()) {
            $iter->next();
            $pos = $iter->current();
            if (!isset($this->overridable[$level->getBlockIdAt($pos->x, $pos->y, $pos->z)])) {
                return $count;
            }
            $count++;
        }
        return -1;
    }