/**
* Singleton pattern
*
* @return QR_Math Singleton
*/
public static function getInstance()
{
if (!self::$instance) {
self::$instance = new self();
}
return self::$instance;
}
/**
* Return error correction polynom
*
* @param int $errorCorrectLength
* @return QR_Polynominal
*/
public function getErrorCorrectPolynominal($errorCorrectLength)
{
$a = new QR_Polynominal(array(1), 0);
for ($i = 0; $i < $errorCorrectLength; $i++) {
$a = $a->multiply(new QR_Polynominal(array(1, QR_Math::getInstance()->gexp($i)), 0));
}
return $a;
}
/**
* Perform modulus against another polynom
*
* @param QR_Polynominal $e
*
* @return QR_Polynominal
*/
public function mod(QR_Polynominal $e)
{
if ($this->getLength() - $e->getLength() < 0) {
return $this;
}
$ratio = QR_Math::getInstance()->glog($this->get(0)) - QR_Math::getInstance()->glog($e->get(0));
$num = QR_Util::getInstance()->createEmptyArray($this->getLength());
for ($i = 0; $i < $this->getLength(); $i++) {
$num[$i] = $this->get($i);
}
for ($i = 0; $i < $e->getLength(); $i++) {
$num[$i] ^= QR_Math::getInstance()->gexp(QR_Math::getInstance()->glog($e->get($i)) + $ratio);
}
$result = new QR_Polynominal($num, 0);
$result = $result->mod($e);
return $result;
}
