qrrscode.php (8485B)
1 <?php 2 /* 3 * PHP QR Code encoder 4 * 5 * Reed-Solomon error correction support 6 * 7 * Copyright (C) 2002, 2003, 2004, 2006 Phil Karn, KA9Q 8 * (libfec is released under the GNU Lesser General Public License.) 9 * 10 * Based on libqrencode C library distributed under LGPL 2.1 11 * Copyright (C) 2006, 2007, 2008, 2009 Kentaro Fukuchi <fukuchi@megaui.net> 12 * 13 * PHP QR Code is distributed under LGPL 3 14 * Copyright (C) 2010 Dominik Dzienia <deltalab at poczta dot fm> 15 * 16 * This library is free software; you can redistribute it and/or 17 * modify it under the terms of the GNU Lesser General Public 18 * License as published by the Free Software Foundation; either 19 * version 3 of the License, or any later version. 20 * 21 * This library is distributed in the hope that it will be useful, 22 * but WITHOUT ANY WARRANTY; without even the implied warranty of 23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 24 * Lesser General Public License for more details. 25 * 26 * You should have received a copy of the GNU Lesser General Public 27 * License along with this library; if not, write to the Free Software 28 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 29 */ 30 31 class QRrsItem { 32 33 public $mm; // Bits per symbol 34 public $nn; // Symbols per block (= (1<<mm)-1) 35 public $alpha_to = array(); // log lookup table 36 public $index_of = array(); // Antilog lookup table 37 public $genpoly = array(); // Generator polynomial 38 public $nroots; // Number of generator roots = number of parity symbols 39 public $fcr; // First consecutive root, index form 40 public $prim; // Primitive element, index form 41 public $iprim; // prim-th root of 1, index form 42 public $pad; // Padding bytes in shortened block 43 public $gfpoly; 44 45 //---------------------------------------------------------------------- 46 public function modnn($x) 47 { 48 while ($x >= $this->nn) { 49 $x -= $this->nn; 50 $x = ($x >> $this->mm) + ($x & $this->nn); 51 } 52 53 return $x; 54 } 55 56 //---------------------------------------------------------------------- 57 public static function init_rs_char($symsize, $gfpoly, $fcr, $prim, $nroots, $pad) 58 { 59 // Common code for intializing a Reed-Solomon control block (char or int symbols) 60 // Copyright 2004 Phil Karn, KA9Q 61 // May be used under the terms of the GNU Lesser General Public License (LGPL) 62 63 $rs = null; 64 65 // Check parameter ranges 66 if($symsize < 0 || $symsize > 8) return $rs; 67 if($fcr < 0 || $fcr >= (1<<$symsize)) return $rs; 68 if($prim <= 0 || $prim >= (1<<$symsize)) return $rs; 69 if($nroots < 0 || $nroots >= (1<<$symsize)) return $rs; // Can't have more roots than symbol values! 70 if($pad < 0 || $pad >= ((1<<$symsize) -1 - $nroots)) return $rs; // Too much padding 71 72 $rs = new QRrsItem(); 73 $rs->mm = $symsize; 74 $rs->nn = (1<<$symsize)-1; 75 $rs->pad = $pad; 76 77 $rs->alpha_to = array_fill(0, $rs->nn+1, 0); 78 $rs->index_of = array_fill(0, $rs->nn+1, 0); 79 80 // PHP style macro replacement ;) 81 $NN =& $rs->nn; 82 $A0 =& $NN; 83 84 // Generate Galois field lookup tables 85 $rs->index_of[0] = $A0; // log(zero) = -inf 86 $rs->alpha_to[$A0] = 0; // alpha**-inf = 0 87 $sr = 1; 88 89 for($i=0; $i<$rs->nn; $i++) { 90 $rs->index_of[$sr] = $i; 91 $rs->alpha_to[$i] = $sr; 92 $sr <<= 1; 93 if($sr & (1<<$symsize)) { 94 $sr ^= $gfpoly; 95 } 96 $sr &= $rs->nn; 97 } 98 99 if($sr != 1){ 100 // field generator polynomial is not primitive! 101 $rs = NULL; 102 return $rs; 103 } 104 105 /* Form RS code generator polynomial from its roots */ 106 $rs->genpoly = array_fill(0, $nroots+1, 0); 107 108 $rs->fcr = $fcr; 109 $rs->prim = $prim; 110 $rs->nroots = $nroots; 111 $rs->gfpoly = $gfpoly; 112 113 /* Find prim-th root of 1, used in decoding */ 114 for($iprim=1;($iprim % $prim) != 0;$iprim += $rs->nn) 115 ; // intentional empty-body loop! 116 117 $rs->iprim = (int)($iprim / $prim); 118 $rs->genpoly[0] = 1; 119 120 for ($i = 0,$root=$fcr*$prim; $i < $nroots; $i++, $root += $prim) { 121 $rs->genpoly[$i+1] = 1; 122 123 // Multiply rs->genpoly[] by @**(root + x) 124 for ($j = $i; $j > 0; $j--) { 125 if ($rs->genpoly[$j] != 0) { 126 $rs->genpoly[$j] = $rs->genpoly[$j-1] ^ $rs->alpha_to[$rs->modnn($rs->index_of[$rs->genpoly[$j]] + $root)]; 127 } else { 128 $rs->genpoly[$j] = $rs->genpoly[$j-1]; 129 } 130 } 131 // rs->genpoly[0] can never be zero 132 $rs->genpoly[0] = $rs->alpha_to[$rs->modnn($rs->index_of[$rs->genpoly[0]] + $root)]; 133 } 134 135 // convert rs->genpoly[] to index form for quicker encoding 136 for ($i = 0; $i <= $nroots; $i++) 137 $rs->genpoly[$i] = $rs->index_of[$rs->genpoly[$i]]; 138 139 return $rs; 140 } 141 142 //---------------------------------------------------------------------- 143 public function encode_rs_char($data, &$parity) 144 { 145 $MM =& $this->mm; 146 $NN =& $this->nn; 147 $ALPHA_TO =& $this->alpha_to; 148 $INDEX_OF =& $this->index_of; 149 $GENPOLY =& $this->genpoly; 150 $NROOTS =& $this->nroots; 151 $FCR =& $this->fcr; 152 $PRIM =& $this->prim; 153 $IPRIM =& $this->iprim; 154 $PAD =& $this->pad; 155 $A0 =& $NN; 156 157 $parity = array_fill(0, $NROOTS, 0); 158 159 for($i=0; $i< ($NN-$NROOTS-$PAD); $i++) { 160 161 $feedback = $INDEX_OF[$data[$i] ^ $parity[0]]; 162 if($feedback != $A0) { 163 // feedback term is non-zero 164 165 // This line is unnecessary when GENPOLY[NROOTS] is unity, as it must 166 // always be for the polynomials constructed by init_rs() 167 $feedback = $this->modnn($NN - $GENPOLY[$NROOTS] + $feedback); 168 169 for($j=1;$j<$NROOTS;$j++) { 170 $parity[$j] ^= $ALPHA_TO[$this->modnn($feedback + $GENPOLY[$NROOTS-$j])]; 171 } 172 } 173 174 // Shift 175 array_shift($parity); 176 if($feedback != $A0) { 177 array_push($parity, $ALPHA_TO[$this->modnn($feedback + $GENPOLY[0])]); 178 } else { 179 array_push($parity, 0); 180 } 181 } 182 } 183 } 184 185 //########################################################################## 186 187 class QRrs { 188 189 public static $items = array(); 190 191 //---------------------------------------------------------------------- 192 public static function init_rs($symsize, $gfpoly, $fcr, $prim, $nroots, $pad) 193 { 194 foreach(self::$items as $rs) { 195 if($rs->pad != $pad) continue; 196 if($rs->nroots != $nroots) continue; 197 if($rs->mm != $symsize) continue; 198 if($rs->gfpoly != $gfpoly) continue; 199 if($rs->fcr != $fcr) continue; 200 if($rs->prim != $prim) continue; 201 202 return $rs; 203 } 204 205 $rs = QRrsItem::init_rs_char($symsize, $gfpoly, $fcr, $prim, $nroots, $pad); 206 array_unshift(self::$items, $rs); 207 208 return $rs; 209 } 210 }