pocketmine\block\RedstoneWire::calcSignal PHP Method

    public function calcSignal($strength = 15, $type = self::ON, array $hasUpdated = [])
    {
        //This algorithm is provided by Stary and written by PeratX
        $hash = Level::blockHash($this->x, $this->y, $this->z);
        if (!in_array($hash, $hasUpdated)) {
            $hasUpdated[] = $hash;
            if ($type == self::DESTROY or $type == self::OFF) {
                $this->meta = $strength;
                $this->getLevel()->setBlock($this, $this, true, false);
                if ($type == self::DESTROY) {
                    $this->getLevel()->setBlock($this, new Air(), true, false);
                }
                if ($strength <= 0) {
                    $this->deactivate();
                }
                $powers = $this->getPowerSources($this, [], [], true);
                /** @var RedstoneSource $power */
                foreach ($powers[0] as $power) {
                    $power->activate();
                }
            } else {
                if ($strength <= 0) {
                    return $hasUpdated;
                }
                if ($type == self::PLACE) {
                    $strength = $this->getHighestStrengthAround() - 1;
                }
                if ($type == self::ON) {
                    $type = self::PLACE;
                }
                if ($this->getStrength() < $strength) {
                    $this->meta = $strength;
                    $this->getLevel()->setBlock($this, $this, true, false);
                    $this->activate();
                    $hasChecked = [Vector3::SIDE_WEST => false, Vector3::SIDE_EAST => false, Vector3::SIDE_NORTH => false, Vector3::SIDE_SOUTH => false];
                    foreach ($hasChecked as $side => $bool) {
                        $needUpdate = $this->getSide($side);
                        if (!in_array(Level::blockHash($needUpdate->x, $needUpdate->y, $needUpdate->z), $hasUpdated)) {
                            $result = $this->updateNormalWire($needUpdate, $strength - 1, $type, $hasUpdated);
                            if (count($result) != count($hasUpdated)) {
                                $hasUpdated = $result;
                                $hasChecked[$side] = true;
                            }
                        }
                    }
                    $baseBlock = $this->add(0, 1, 0);
                    foreach ($hasChecked as $side => $bool) {
                        if (!$bool) {
                            $needUpdate = $this->getLevel()->getBlock($baseBlock->getSide($side));
                            if (!in_array(Level::blockHash($needUpdate->x, $needUpdate->y, $needUpdate->z), $hasUpdated)) {
                                $result = $this->updateNormalWire($needUpdate, $strength - 1, $type, $hasUpdated);
                                if (count($result) != count($hasUpdated)) {
                                    $hasUpdated = $result;
                                    $hasChecked[$side] = true;
                                }
                            }
                        }
                    }
                    $baseBlock = $this->add(0, -1, 0);
                    foreach ($hasChecked as $side => $bool) {
                        if (!$bool) {
                            $needUpdate = $this->getLevel()->getBlock($baseBlock->getSide($side));
                            if (!in_array(Level::blockHash($needUpdate->x, $needUpdate->y, $needUpdate->z), $hasUpdated)) {
                                $result = $this->updateNormalWire($needUpdate, $strength - 1, $type, $hasUpdated);
                                if (count($result) != count($hasUpdated)) {
                                    $hasUpdated = $result;
                                    $hasChecked[$side] = true;
                                }
                            }
                        }
                    }
                }
            }
        }
        return $hasUpdated;
    }