<?php
namespace Zxing\Qrcode\Decoder;
use Zxing\Common\BitMatrix;
/**
* <p>Encapsulates data masks for the data bits in a QR code, per ISO 18004:2006 6.8. Implementations
* of this class can un-mask a raw BitMatrix. For simplicity, they will unmask the entire BitMatrix,
* including areas used for finder patterns, timing patterns, etc. These areas should be unused
* after the point they are unmasked anyway.</p>
*
* <p>Note that the diagram in section 6.8.1 is misleading since it indicates that i is column position
* and j is row position. In fact, as the text says, i is row position and j is column position.</p>
*
* @author Sean Owen
*/
abstract class DataMask
{
private static array $DATA_MASKS = [];
public function __construct()
{
}
public static function Init(): void
{
self::$DATA_MASKS = [
new DataMask000(),
new DataMask001(),
new DataMask010(),
new DataMask011(),
new DataMask100(),
new DataMask101(),
new DataMask110(),
new DataMask111(),
];
}
public static function forReference($reference)
{
if ($reference < 0 || $reference > 7) {
throw new \InvalidArgumentException();
}
return self::$DATA_MASKS[$reference];
}
/**
* <p>Implementations of this method reverse the data masking process applied to a QR Code and
* make its bits ready to read.</p>
*
* @param representation $bits of QR Code bits
* @param dimension $dimension of QR Code, represented by bits, being unmasked
*/
final public function unmaskBitMatrix($bits, $dimension): void
{
for ($i = 0; $i < $dimension; $i++) {
for ($j = 0; $j < $dimension; $j++) {
if ($this->isMasked($i, $j)) {
$bits->flip($j, $i);
}
}
}
}
abstract public function isMasked($i, $j);
}
DataMask::Init();
final class DataMask000 extends DataMask
{
public function isMasked($i, $j)
{
return (($i + $j) & 0x01) == 0;
}
}
final class DataMask001 extends DataMask
{
public function isMasked($i, $j)
{
return ($i & 0x01) == 0;
}
}
final class DataMask010 extends DataMask
{
public function isMasked($i, $j)
{
return $j % 3 == 0;
}
}
final class DataMask011 extends DataMask
{
public function isMasked($i, $j)
{
return ($i + $j) % 3 == 0;
}
}
final class DataMask100 extends DataMask
{
public function isMasked($i, $j)
{
return (int)(((int)($i / 2) + (int)($j / 3)) & 0x01) == 0;
}
}
final class DataMask101 extends DataMask
{
public function isMasked($i, $j)
{
$temp = $i * $j;
return ($temp & 0x01) + ($temp % 3) == 0;
}
}
final class DataMask110 extends DataMask
{
public function isMasked($i, $j)
{
$temp = $i * $j;
return ((($temp & 0x01) + ($temp % 3)) & 0x01) == 0;
}
}
final class DataMask111 extends DataMask
{
public function isMasked($i, $j)
{
return (((($i + $j) & 0x01) + (($i * $j) % 3)) & 0x01) == 0;
}
}