Method mask

text-to-qr/lib/phpqrcode/phpqrcode.php:2757–2797

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($width, $frame, $level)

        
        //----------------------------------------------------------------------
        public function mask($width, $frame, $level)
        {
            $minDemerit = PHP_INT_MAX;
            $bestMaskNum = 0;
            $bestMask = array();
            
            $checked_masks = array(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;
        }
        
        //----------------------------------------------------------------------
    }