<?php

/*

 * PHP QR Code encoder

 *

 * Masking

 *

 * Based on libqrencode C library distributed under LGPL 2.1

 * Copyright (C) 2006, 2007, 2008, 2009 Kentaro Fukuchi <fukuchi@megaui.net>

 *

 * PHP QR Code is distributed under LGPL 3

 * Copyright (C) 2010 Dominik Dzienia <deltalab at poczta dot fm>

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 3 of the License, or any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

 */

 

	define('N1', 3);

	define('N2', 3);

	define('N3', 40);

	define('N4', 10);



	class QRmask {

	

		public $runLength = array();

		

		//----------------------------------------------------------------------

		public function __construct() 

        {

            $this->runLength = array_fill(0, QRSPEC_WIDTH_MAX + 1, 0);

        }

        

        //----------------------------------------------------------------------

        public function writeFormatInformation($width, &$frame, $mask, $level)

        {

            $blacks = 0;

            $format =  QRspec::getFormatInfo($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;

        }

        

        //----------------------------------------------------------------------

        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;     }

        

        //----------------------------------------------------------------------

        private function generateMaskNo($maskNo, $width, $frame)

        {

            $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 {

                        $maskFunc = call_user_func(array($this, 'mask'.$maskNo), $x, $y);

                        $bitMask[$y][$x] = ($maskFunc == 0)?1:0;

                    }

                    

                }

            }

            

            return $bitMask;

        }

        

        //----------------------------------------------------------------------

        public static function serial($bitFrame)

        {

            $codeArr = array();

            

            foreach ($bitFrame as $line)

                $codeArr[] = join('', $line);

                

            return gzcompress(join("\n", $codeArr), 9);

        }

        

        //----------------------------------------------------------------------

        public static function unserial($code)

        {

            $codeArr = array();

            

            $codeLines = explode("\n", gzuncompress($code));

            foreach ($codeLines as $line)

                $codeArr[] = str_split($line);

            

            return $codeArr;

        }

        

        //----------------------------------------------------------------------

        public function makeMaskNo($maskNo, $width, $s, &$d, $maskGenOnly = false) 

        {

            $b = 0;

            $bitMask = array();

            

            $fileName = QR_CACHE_DIR.'mask_'.$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;

                

            $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;

        }

        

        //----------------------------------------------------------------------

        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;

        }

        

        //----------------------------------------------------------------------

        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;

                            } else if((($i+3) >= $length) || ($this->runLength[$i+3] >= (4 * $fact))) {

                                $demerit += N3;

                            }

                        }

                    }

                }

            }

            return $demerit;

        }

        

        //----------------------------------------------------------------------

        public function evaluateSymbol($width, $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;

                    } else if($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;

                    } else if($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;

        }

        

        

        //----------------------------------------------------------------------

        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;

        }

        

        //----------------------------------------------------------------------

    }

