src/QR_Code/Encoder/Mask.php
<?php
namespace QR_Code\Encoder;
use QR_Code\Config\Specifications;
/**
* Class Mask
*
* Based on PHP QR Code distributed under LGPL 3
* Copyright (C) 2010 Dominik Dzienia <deltalab at poczta dot fm>
*
* QR Code Generator for PHP is distributed under MIT
* Copyright (C) 2018 Bruno Vaula Werneck <brunovaulawerneck at gmail dot com>
*
* @package QR_Code\Encoder
*/
class Mask
{
public $runLength = [];
/**
* Mask constructor.
*/
public function __construct ()
{
$this->runLength = array_fill(0, QRSPEC_WIDTH_MAX + 1, 0);
}
/**
* @param int $width
* @param array $frame
* @param int $mask
* @param int $level
* @return int
*/
public function writeFormatInformation (int $width, array &$frame, int $mask, int $level) : int
{
$blacks = 0;
$format = Specifications::getFormatInfo($mask, $level);
for ($i = 0; $i < 8; $i++) {
if ($format & 1) {
$blacks += 2;
$v = 0x85;
} else {
$v = 0x84;
}
$frame[8][$width - 1 - $i] = chr($v);
if ($i < 6) {
$frame[$i][8] = chr($v);
} else {
$frame[$i + 1][8] = chr($v);
}
$format = $format >> 1;
}
for ($i = 0; $i < 7; $i++) {
if ($format & 1) {
$blacks += 2;
$v = 0x85;
} else {
$v = 0x84;
}
$frame[$width - 7 + $i][8] = chr($v);
if ($i == 0) {
$frame[8][7] = chr($v);
} else {
$frame[8][6 - $i] = chr($v);
}
$format = $format >> 1;
}
return $blacks;
}
/**
* @param $x
* @param $y
* @return int
*/
public function mask0 ($x, $y) { return ($x + $y) & 1; }
public function mask1 ($x, $y) { return ($y & 1); }
public function mask2 ($x, $y) { return ($x % 3); }
public function mask3 ($x, $y) { return ($x + $y) % 3; }
public function mask4 ($x, $y) { return (((int) ($y / 2)) + ((int) ($x / 3))) & 1; }
public function mask5 ($x, $y) { return (($x * $y) & 1) + ($x * $y) % 3; }
public function mask6 ($x, $y) { return ((($x * $y) & 1) + ($x * $y) % 3) & 1; }
public function mask7 ($x, $y) { return ((($x * $y) % 3) + (($x + $y) & 1)) & 1; }
/**
* @param mixed $maskNo
* @param int $width
* @param array $frame
* @return array
*/
private function generateMaskNo ($maskNo, int $width, array $frame) : array
{
$bitMask = array_fill(0, $width, array_fill(0, $width, 0));
for ($y = 0; $y < $width; $y++) {
for ($x = 0; $x < $width; $x++) {
if (ord($frame[$y][$x]) & 0x80) {
$bitMask[$y][$x] = 0;
} else {
$maskFunc = call_user_func([$this, 'mask' . $maskNo], $x, $y);
$bitMask[$y][$x] = ($maskFunc == 0) ? 1 : 0;
}
}
}
return $bitMask;
}
/**
* @param array $bitFrame
* @return string
*/
public static function serial (array $bitFrame) : string
{
$codeArr = [];
foreach ($bitFrame as $line)
$codeArr[] = join('', $line);
return gzcompress(join("\n", $codeArr), 9);
}
/**
* @param string $code
* @return array
*/
public static function unserial (string $code) : array
{
$codeArr = [];
$codeLines = explode("\n", gzuncompress($code));
foreach ($codeLines as $line)
$codeArr[] = str_split($line);
return $codeArr;
}
/**
* @param $maskNo
* @param $width
* @param $s
* @param $d
* @param bool $maskGenOnly
* @return int|null
*/
public function makeMaskNo ($maskNo, $width, $s, &$d, $maskGenOnly = false)
{
$b = 0;
$bitMask = [];
$fileName = QR_CACHE_DIR . 'mask_' . $maskNo . DIRECTORY_SEPARATOR . 'mask_' . $width . '_' . $maskNo . '.dat';
if (QR_CACHEABLE) {
if (file_exists($fileName)) {
$bitMask = self::unserial(file_get_contents($fileName));
} else {
$bitMask = $this->generateMaskNo($maskNo, $width, $s, $d);
if (!file_exists(QR_CACHE_DIR . 'mask_' . $maskNo))
mkdir(QR_CACHE_DIR . 'mask_' . $maskNo);
file_put_contents($fileName, self::serial($bitMask));
}
} else {
$bitMask = $this->generateMaskNo($maskNo, $width, $s, $d);
}
if ($maskGenOnly)
return null;
$d = $s;
for ($y = 0; $y < $width; $y++) {
for ($x = 0; $x < $width; $x++) {
if ($bitMask[$y][$x] == 1) {
$d[$y][$x] = chr(ord($s[$y][$x]) ^ (int) $bitMask[$y][$x]);
}
$b += (int) (ord($d[$y][$x]) & 1);
}
}
return $b;
}
/**
* @param $width
* @param $frame
* @param $maskNo
* @param $level
* @return array
*/
public function makeMask ($width, $frame, $maskNo, $level)
{
$masked = array_fill(0, $width, str_repeat("\0", $width));
$this->makeMaskNo($maskNo, $width, $frame, $masked);
$this->writeFormatInformation($width, $masked, $maskNo, $level);
return $masked;
}
/**
* @param $length
* @return int|mixed
*/
public function calcN1N3 ($length)
{
$demerit = 0;
for ($i = 0; $i < $length; $i++) {
if ($this->runLength[$i] >= 5) {
$demerit += (N1 + ($this->runLength[$i] - 5));
}
if ($i & 1) {
if (($i >= 3) && ($i < ($length - 2)) && ($this->runLength[$i] % 3 == 0)) {
$fact = (int) ($this->runLength[$i] / 3);
if (($this->runLength[$i - 2] == $fact) &&
($this->runLength[$i - 1] == $fact) &&
($this->runLength[$i + 1] == $fact) &&
($this->runLength[$i + 2] == $fact)) {
if (($this->runLength[$i - 3] < 0) || ($this->runLength[$i - 3] >= (4 * $fact))) {
$demerit += N3;
} elseif ((($i + 3) >= $length) || ($this->runLength[$i + 3] >= (4 * $fact))) {
$demerit += N3;
}
}
}
}
}
return $demerit;
}
/**
* @param int $width
* @param array $frame
* @return int|mixed
*/
public function evaluateSymbol (int $width, array $frame)
{
$head = 0;
$demerit = 0;
for ($y = 0; $y < $width; $y++) {
$head = 0;
$this->runLength[0] = 1;
$frameY = $frame[$y];
if ($y > 0)
$frameYM = $frame[$y - 1];
for ($x = 0; $x < $width; $x++) {
if (($x > 0) && ($y > 0)) {
$b22 = ord($frameY[$x]) & ord($frameY[$x - 1]) & ord($frameYM[$x]) & ord($frameYM[$x - 1]);
$w22 = ord($frameY[$x]) | ord($frameY[$x - 1]) | ord($frameYM[$x]) | ord($frameYM[$x - 1]);
if (($b22 | ($w22 ^ 1)) & 1) {
$demerit += N2;
}
}
if (($x == 0) && (ord($frameY[$x]) & 1)) {
$this->runLength[0] = -1;
$head = 1;
$this->runLength[$head] = 1;
} elseif ($x > 0) {
if ((ord($frameY[$x]) ^ ord($frameY[$x - 1])) & 1) {
$head++;
$this->runLength[$head] = 1;
} else {
$this->runLength[$head]++;
}
}
}
$demerit += $this->calcN1N3($head + 1);
}
for ($x = 0; $x < $width; $x++) {
$head = 0;
$this->runLength[0] = 1;
for ($y = 0; $y < $width; $y++) {
if ($y == 0 && (ord($frame[$y][$x]) & 1)) {
$this->runLength[0] = -1;
$head = 1;
$this->runLength[$head] = 1;
} elseif ($y > 0) {
if ((ord($frame[$y][$x]) ^ ord($frame[$y - 1][$x])) & 1) {
$head++;
$this->runLength[$head] = 1;
} else {
$this->runLength[$head]++;
}
}
}
$demerit += $this->calcN1N3($head + 1);
}
return $demerit;
}
/**
* @param int $width
* @param array $frame
* @param int $level
* @return array
*/
public function mask (int $width, array $frame, int $level) : array
{
$minDemerit = PHP_INT_MAX;
$bestMaskNum = 0;
$bestMask = [];
$checked_masks = [0, 1, 2, 3, 4, 5, 6, 7];
if (QR_FIND_FROM_RANDOM !== false) {
$howManuOut = 8 - (QR_FIND_FROM_RANDOM % 9);
for ($i = 0; $i < $howManuOut; $i++) {
$remPos = rand(0, count($checked_masks) - 1);
unset($checked_masks[$remPos]);
$checked_masks = array_values($checked_masks);
}
}
$bestMask = $frame;
foreach ($checked_masks as $i) {
$mask = array_fill(0, $width, str_repeat("\0", $width));
$demerit = 0;
$blacks = 0;
$blacks = $this->makeMaskNo($i, $width, $frame, $mask);
$blacks += $this->writeFormatInformation($width, $mask, $i, $level);
$blacks = (int) (100 * $blacks / ($width * $width));
$demerit = (int) ((int) (abs($blacks - 50) / 5) * N4);
$demerit += $this->evaluateSymbol($width, $mask);
if ($demerit < $minDemerit) {
$minDemerit = $demerit;
$bestMask = $mask;
$bestMaskNum = $i;
}
}
return $bestMask;
}
}