| 1 |
<?php |
| 2 |
/** |
| 3 |
* QR Code SVG Generator |
| 4 |
* |
| 5 |
* Minimal QR code generator for TOTP URIs. Outputs SVG. |
| 6 |
* Supports byte mode, ECL L, versions 1-10. |
| 7 |
* No external dependencies, pure PHP. |
| 8 |
* |
| 9 |
* @package Vigilante |
| 10 |
*/ |
| 11 |
|
| 12 |
// Prevent direct access |
| 13 |
if ( ! defined( 'ABSPATH' ) ) { |
| 14 |
exit; |
| 15 |
} |
| 16 |
|
| 17 |
/** |
| 18 |
* Class Vigilante_QR_SVG |
| 19 |
* |
| 20 |
* Generates QR code as inline SVG string |
| 21 |
*/ |
| 22 |
class Vigilante_QR_SVG { |
| 23 |
|
| 24 |
/** |
| 25 |
* GF(2^8) exponential table |
| 26 |
* |
| 27 |
* @var array |
| 28 |
*/ |
| 29 |
private $gf_exp = array(); |
| 30 |
|
| 31 |
/** |
| 32 |
* GF(2^8) logarithm table |
| 33 |
* |
| 34 |
* @var array |
| 35 |
*/ |
| 36 |
private $gf_log = array(); |
| 37 |
|
| 38 |
/** |
| 39 |
* QR modules matrix |
| 40 |
* |
| 41 |
* @var array |
| 42 |
*/ |
| 43 |
private $modules = array(); |
| 44 |
|
| 45 |
/** |
| 46 |
* Function pattern mask (true = reserved module) |
| 47 |
* |
| 48 |
* @var array |
| 49 |
*/ |
| 50 |
private $reserved = array(); |
| 51 |
|
| 52 |
/** |
| 53 |
* QR code size (modules per side) |
| 54 |
* |
| 55 |
* @var int |
| 56 |
*/ |
| 57 |
private $size = 0; |
| 58 |
|
| 59 |
/** |
| 60 |
* Data capacity per version at ECL L (byte mode) |
| 61 |
* |
| 62 |
* @var array |
| 63 |
*/ |
| 64 |
private static $capacity = array( |
| 65 |
1 => 17, |
| 66 |
2 => 32, |
| 67 |
3 => 53, |
| 68 |
4 => 78, |
| 69 |
5 => 106, |
| 70 |
6 => 134, |
| 71 |
7 => 154, |
| 72 |
8 => 192, |
| 73 |
9 => 230, |
| 74 |
10 => 271, |
| 75 |
); |
| 76 |
|
| 77 |
/** |
| 78 |
* Total data codewords per version at ECL L |
| 79 |
* |
| 80 |
* @var array |
| 81 |
*/ |
| 82 |
private static $total_codewords = array( |
| 83 |
1 => 19, |
| 84 |
2 => 34, |
| 85 |
3 => 55, |
| 86 |
4 => 80, |
| 87 |
5 => 108, |
| 88 |
6 => 136, |
| 89 |
7 => 156, |
| 90 |
8 => 194, |
| 91 |
9 => 232, |
| 92 |
10 => 274, |
| 93 |
); |
| 94 |
|
| 95 |
/** |
| 96 |
* EC codewords per block at ECL L |
| 97 |
* |
| 98 |
* @var array |
| 99 |
*/ |
| 100 |
private static $ec_codewords = array( |
| 101 |
1 => 7, |
| 102 |
2 => 10, |
| 103 |
3 => 15, |
| 104 |
4 => 20, |
| 105 |
5 => 26, |
| 106 |
6 => 18, |
| 107 |
7 => 20, |
| 108 |
8 => 24, |
| 109 |
9 => 30, |
| 110 |
10 => 18, |
| 111 |
); |
| 112 |
|
| 113 |
/** |
| 114 |
* Block structure at ECL L: array( [num_blocks_group1, dc_per_block_g1, num_blocks_group2, dc_per_block_g2] ) |
| 115 |
* |
| 116 |
* @var array |
| 117 |
*/ |
| 118 |
private static $blocks = array( |
| 119 |
1 => array( 1, 19, 0, 0 ), |
| 120 |
2 => array( 1, 34, 0, 0 ), |
| 121 |
3 => array( 1, 55, 0, 0 ), |
| 122 |
4 => array( 1, 80, 0, 0 ), |
| 123 |
5 => array( 1, 108, 0, 0 ), |
| 124 |
6 => array( 2, 68, 0, 0 ), |
| 125 |
7 => array( 2, 78, 0, 0 ), |
| 126 |
8 => array( 2, 97, 0, 0 ), |
| 127 |
9 => array( 2, 116, 0, 0 ), |
| 128 |
10 => array( 2, 68, 2, 69 ), |
| 129 |
); |
| 130 |
|
| 131 |
/** |
| 132 |
* Alignment pattern center positions per version |
| 133 |
* |
| 134 |
* @var array |
| 135 |
*/ |
| 136 |
private static $alignment = array( |
| 137 |
2 => array( 6, 18 ), |
| 138 |
3 => array( 6, 22 ), |
| 139 |
4 => array( 6, 26 ), |
| 140 |
5 => array( 6, 30 ), |
| 141 |
6 => array( 6, 34 ), |
| 142 |
7 => array( 6, 22, 38 ), |
| 143 |
8 => array( 6, 24, 42 ), |
| 144 |
9 => array( 6, 26, 46 ), |
| 145 |
10 => array( 6, 28, 52 ), |
| 146 |
); |
| 147 |
|
| 148 |
/** |
| 149 |
* Constructor - initialize GF(2^8) tables |
| 150 |
*/ |
| 151 |
public function __construct() { |
| 152 |
$this->init_galois_field(); |
| 153 |
} |
| 154 |
|
| 155 |
/** |
| 156 |
* Generate QR code as SVG string |
| 157 |
* |
| 158 |
* @param string $data Data to encode. |
| 159 |
* @param int $px_size Pixel size per module (default 4). |
| 160 |
* @param int $margin Quiet zone modules (default 4). |
| 161 |
* @return string SVG markup or empty string on failure. |
| 162 |
*/ |
| 163 |
public function generate( $data, $px_size = 4, $margin = 4 ) { |
| 164 |
if ( empty( $data ) ) { |
| 165 |
return ''; |
| 166 |
} |
| 167 |
|
| 168 |
// Select version |
| 169 |
$version = $this->select_version( strlen( $data ) ); |
| 170 |
if ( ! $version ) { |
| 171 |
return ''; |
| 172 |
} |
| 173 |
|
| 174 |
$this->size = 17 + $version * 4; |
| 175 |
|
| 176 |
// Initialize matrix |
| 177 |
$this->modules = array_fill( 0, $this->size, array_fill( 0, $this->size, null ) ); |
| 178 |
$this->reserved = array_fill( 0, $this->size, array_fill( 0, $this->size, false ) ); |
| 179 |
|
| 180 |
// Place function patterns |
| 181 |
$this->place_finder_patterns(); |
| 182 |
$this->place_alignment_patterns( $version ); |
| 183 |
$this->place_timing_patterns(); |
| 184 |
$this->reserve_format_area(); |
| 185 |
|
| 186 |
if ( $version >= 7 ) { |
| 187 |
$this->reserve_version_area(); |
| 188 |
} |
| 189 |
|
| 190 |
// Encode data |
| 191 |
$encoded = $this->encode_data( $data, $version ); |
| 192 |
if ( empty( $encoded ) ) { |
| 193 |
return ''; |
| 194 |
} |
| 195 |
|
| 196 |
// Add error correction |
| 197 |
$final_data = $this->add_error_correction( $encoded, $version ); |
| 198 |
|
| 199 |
// Place data bits |
| 200 |
$this->place_data_bits( $final_data ); |
| 201 |
|
| 202 |
// Apply best mask |
| 203 |
$best_mask = $this->apply_best_mask(); |
| 204 |
|
| 205 |
// Place format information |
| 206 |
$this->place_format_info( $best_mask ); |
| 207 |
|
| 208 |
// Place version information |
| 209 |
if ( $version >= 7 ) { |
| 210 |
$this->place_version_info( $version ); |
| 211 |
} |
| 212 |
|
| 213 |
// Generate SVG |
| 214 |
return $this->render_svg( $px_size, $margin ); |
| 215 |
} |
| 216 |
|
| 217 |
/** |
| 218 |
* Initialize GF(2^8) exp and log tables with polynomial 0x11D |
| 219 |
*/ |
| 220 |
private function init_galois_field() { |
| 221 |
$x = 1; |
| 222 |
for ( $i = 0; $i < 255; $i++ ) { |
| 223 |
$this->gf_exp[ $i ] = $x; |
| 224 |
$this->gf_log[ $x ] = $i; |
| 225 |
$x <<= 1; |
| 226 |
if ( $x & 0x100 ) { |
| 227 |
$x ^= 0x11d; |
| 228 |
} |
| 229 |
} |
| 230 |
// Extend exp table for convenience |
| 231 |
for ( $i = 255; $i < 512; $i++ ) { |
| 232 |
$this->gf_exp[ $i ] = $this->gf_exp[ $i - 255 ]; |
| 233 |
} |
| 234 |
} |
| 235 |
|
| 236 |
/** |
| 237 |
* Multiply two values in GF(2^8) |
| 238 |
* |
| 239 |
* @param int $a First value. |
| 240 |
* @param int $b Second value. |
| 241 |
* @return int Product. |
| 242 |
*/ |
| 243 |
private function gf_mul( $a, $b ) { |
| 244 |
if ( 0 === $a || 0 === $b ) { |
| 245 |
return 0; |
| 246 |
} |
| 247 |
return $this->gf_exp[ $this->gf_log[ $a ] + $this->gf_log[ $b ] ]; |
| 248 |
} |
| 249 |
|
| 250 |
/** |
| 251 |
* Generate Reed-Solomon generator polynomial |
| 252 |
* |
| 253 |
* @param int $num_ec Number of EC codewords. |
| 254 |
* @return array Generator polynomial coefficients. |
| 255 |
*/ |
| 256 |
private function rs_generator( $num_ec ) { |
| 257 |
$gen = array( 1 ); |
| 258 |
for ( $i = 0; $i < $num_ec; $i++ ) { |
| 259 |
$new_gen = array_fill( 0, count( $gen ) + 1, 0 ); |
| 260 |
for ( $j = 0; $j < count( $gen ); $j++ ) { |
| 261 |
$new_gen[ $j ] ^= $gen[ $j ]; |
| 262 |
$new_gen[ $j + 1 ] ^= $this->gf_mul( $gen[ $j ], $this->gf_exp[ $i ] ); |
| 263 |
} |
| 264 |
$gen = $new_gen; |
| 265 |
} |
| 266 |
return $gen; |
| 267 |
} |
| 268 |
|
| 269 |
/** |
| 270 |
* Reed-Solomon encode a data block |
| 271 |
* |
| 272 |
* @param array $data Data codewords. |
| 273 |
* @param int $num_ec Number of EC codewords. |
| 274 |
* @return array EC codewords. |
| 275 |
*/ |
| 276 |
private function rs_encode( $data, $num_ec ) { |
| 277 |
$gen = $this->rs_generator( $num_ec ); |
| 278 |
$enc = array_merge( $data, array_fill( 0, $num_ec, 0 ) ); |
| 279 |
|
| 280 |
for ( $i = 0; $i < count( $data ); $i++ ) { |
| 281 |
$coef = $enc[ $i ]; |
| 282 |
if ( 0 !== $coef ) { |
| 283 |
for ( $j = 0; $j < count( $gen ); $j++ ) { |
| 284 |
$enc[ $i + $j ] ^= $this->gf_mul( $gen[ $j ], $coef ); |
| 285 |
} |
| 286 |
} |
| 287 |
} |
| 288 |
|
| 289 |
return array_slice( $enc, count( $data ) ); |
| 290 |
} |
| 291 |
|
| 292 |
/** |
| 293 |
* Select minimum QR version for data length |
| 294 |
* |
| 295 |
* @param int $length Data length in bytes. |
| 296 |
* @return int|false Version number or false. |
| 297 |
*/ |
| 298 |
private function select_version( $length ) { |
| 299 |
foreach ( self::$capacity as $v => $cap ) { |
| 300 |
if ( $length <= $cap ) { |
| 301 |
return $v; |
| 302 |
} |
| 303 |
} |
| 304 |
return false; |
| 305 |
} |
| 306 |
|
| 307 |
/** |
| 308 |
* Encode data in byte mode |
| 309 |
* |
| 310 |
* @param string $data Raw data string. |
| 311 |
* @param int $version QR version. |
| 312 |
* @return array Codewords array. |
| 313 |
*/ |
| 314 |
private function encode_data( $data, $version ) { |
| 315 |
$bits = ''; |
| 316 |
|
| 317 |
// Mode indicator: 0100 (byte mode) |
| 318 |
$bits .= '0100'; |
| 319 |
|
| 320 |
// Character count indicator |
| 321 |
$cc_bits = $version <= 9 ? 8 : 16; |
| 322 |
$bits .= str_pad( decbin( strlen( $data ) ), $cc_bits, '0', STR_PAD_LEFT ); |
| 323 |
|
| 324 |
// Data bytes |
| 325 |
for ( $i = 0; $i < strlen( $data ); $i++ ) { |
| 326 |
$bits .= str_pad( decbin( ord( $data[ $i ] ) ), 8, '0', STR_PAD_LEFT ); |
| 327 |
} |
| 328 |
|
| 329 |
// Terminator (up to 4 bits) |
| 330 |
// $total_codewords already contains DATA codewords count (EC excluded) |
| 331 |
$total_dc = self::$total_codewords[ $version ]; |
| 332 |
$max_bits = $total_dc * 8; |
| 333 |
|
| 334 |
$term_len = max( 0, min( 4, $max_bits - strlen( $bits ) ) ); |
| 335 |
$bits .= str_repeat( '0', $term_len ); |
| 336 |
|
| 337 |
// Pad to byte boundary |
| 338 |
if ( strlen( $bits ) % 8 !== 0 ) { |
| 339 |
$bits .= str_repeat( '0', 8 - ( strlen( $bits ) % 8 ) ); |
| 340 |
} |
| 341 |
|
| 342 |
// Convert to codewords |
| 343 |
$codewords = array(); |
| 344 |
for ( $i = 0; $i < strlen( $bits ); $i += 8 ) { |
| 345 |
$codewords[] = intval( substr( $bits, $i, 8 ), 2 ); |
| 346 |
} |
| 347 |
|
| 348 |
// Pad with alternating 236/17 to fill capacity |
| 349 |
$pad = array( 236, 17 ); |
| 350 |
$pad_idx = 0; |
| 351 |
while ( count( $codewords ) < $total_dc ) { |
| 352 |
$codewords[] = $pad[ $pad_idx % 2 ]; |
| 353 |
$pad_idx++; |
| 354 |
} |
| 355 |
|
| 356 |
return $codewords; |
| 357 |
} |
| 358 |
|
| 359 |
/** |
| 360 |
* Get total number of blocks for a version |
| 361 |
* |
| 362 |
* @param int $version QR version. |
| 363 |
* @return int Total blocks. |
| 364 |
*/ |
| 365 |
private function get_total_blocks( $version ) { |
| 366 |
$b = self::$blocks[ $version ]; |
| 367 |
return $b[0] + $b[2]; |
| 368 |
} |
| 369 |
|
| 370 |
/** |
| 371 |
* Add error correction and interleave blocks |
| 372 |
* |
| 373 |
* @param array $data Data codewords. |
| 374 |
* @param int $version QR version. |
| 375 |
* @return array Final codeword sequence. |
| 376 |
*/ |
| 377 |
private function add_error_correction( $data, $version ) { |
| 378 |
$b = self::$blocks[ $version ]; |
| 379 |
$ec_per = self::$ec_codewords[ $version ]; |
| 380 |
|
| 381 |
$data_blocks = array(); |
| 382 |
$ec_blocks = array(); |
| 383 |
$offset = 0; |
| 384 |
|
| 385 |
// Group 1 |
| 386 |
for ( $i = 0; $i < $b[0]; $i++ ) { |
| 387 |
$block = array_slice( $data, $offset, $b[1] ); |
| 388 |
$data_blocks[] = $block; |
| 389 |
$ec_blocks[] = $this->rs_encode( $block, $ec_per ); |
| 390 |
$offset += $b[1]; |
| 391 |
} |
| 392 |
|
| 393 |
// Group 2 |
| 394 |
for ( $i = 0; $i < $b[2]; $i++ ) { |
| 395 |
$block = array_slice( $data, $offset, $b[3] ); |
| 396 |
$data_blocks[] = $block; |
| 397 |
$ec_blocks[] = $this->rs_encode( $block, $ec_per ); |
| 398 |
$offset += $b[3]; |
| 399 |
} |
| 400 |
|
| 401 |
// Interleave data codewords |
| 402 |
$result = array(); |
| 403 |
$max_data = max( $b[1], $b[3] ); |
| 404 |
for ( $i = 0; $i < $max_data; $i++ ) { |
| 405 |
foreach ( $data_blocks as $block ) { |
| 406 |
if ( $i < count( $block ) ) { |
| 407 |
$result[] = $block[ $i ]; |
| 408 |
} |
| 409 |
} |
| 410 |
} |
| 411 |
|
| 412 |
// Interleave EC codewords |
| 413 |
for ( $i = 0; $i < $ec_per; $i++ ) { |
| 414 |
foreach ( $ec_blocks as $block ) { |
| 415 |
if ( $i < count( $block ) ) { |
| 416 |
$result[] = $block[ $i ]; |
| 417 |
} |
| 418 |
} |
| 419 |
} |
| 420 |
|
| 421 |
// Add remainder bits (version-dependent) |
| 422 |
$remainder_bits = array( 0, 0, 7, 7, 7, 7, 0, 0, 0, 0, 0 ); |
| 423 |
// Not added as codewords, but as bits during placement |
| 424 |
|
| 425 |
return $result; |
| 426 |
} |
| 427 |
|
| 428 |
/** |
| 429 |
* Place finder patterns at three corners |
| 430 |
*/ |
| 431 |
private function place_finder_patterns() { |
| 432 |
$positions = array( |
| 433 |
array( 0, 0 ), |
| 434 |
array( 0, $this->size - 7 ), |
| 435 |
array( $this->size - 7, 0 ), |
| 436 |
); |
| 437 |
|
| 438 |
foreach ( $positions as $pos ) { |
| 439 |
$r = $pos[0]; |
| 440 |
$c = $pos[1]; |
| 441 |
for ( $dr = 0; $dr < 7; $dr++ ) { |
| 442 |
for ( $dc = 0; $dc < 7; $dc++ ) { |
| 443 |
$dark = ( 0 === $dr || 6 === $dr || 0 === $dc || 6 === $dc ) |
| 444 |
|| ( $dr >= 2 && $dr <= 4 && $dc >= 2 && $dc <= 4 ); |
| 445 |
$this->set_module( $r + $dr, $c + $dc, $dark, true ); |
| 446 |
} |
| 447 |
} |
| 448 |
} |
| 449 |
|
| 450 |
// Separators |
| 451 |
for ( $i = 0; $i < 8; $i++ ) { |
| 452 |
// Top-left |
| 453 |
$this->set_module( 7, $i, false, true ); |
| 454 |
$this->set_module( $i, 7, false, true ); |
| 455 |
// Top-right |
| 456 |
$this->set_module( 7, $this->size - 8 + $i, false, true ); |
| 457 |
$this->set_module( $i, $this->size - 8, false, true ); |
| 458 |
// Bottom-left |
| 459 |
$this->set_module( $this->size - 8, $i, false, true ); |
| 460 |
$this->set_module( $this->size - 8 + $i, 7, false, true ); |
| 461 |
} |
| 462 |
} |
| 463 |
|
| 464 |
/** |
| 465 |
* Place alignment patterns |
| 466 |
* |
| 467 |
* @param int $version QR version. |
| 468 |
*/ |
| 469 |
private function place_alignment_patterns( $version ) { |
| 470 |
if ( ! isset( self::$alignment[ $version ] ) ) { |
| 471 |
return; |
| 472 |
} |
| 473 |
|
| 474 |
$positions = self::$alignment[ $version ]; |
| 475 |
$combos = array(); |
| 476 |
|
| 477 |
foreach ( $positions as $r ) { |
| 478 |
foreach ( $positions as $c ) { |
| 479 |
$combos[] = array( $r, $c ); |
| 480 |
} |
| 481 |
} |
| 482 |
|
| 483 |
foreach ( $combos as $pos ) { |
| 484 |
$r = $pos[0]; |
| 485 |
$c = $pos[1]; |
| 486 |
|
| 487 |
// Skip if overlapping finder pattern |
| 488 |
if ( $this->reserved[ $r ][ $c ] ) { |
| 489 |
continue; |
| 490 |
} |
| 491 |
|
| 492 |
for ( $dr = -2; $dr <= 2; $dr++ ) { |
| 493 |
for ( $dc = -2; $dc <= 2; $dc++ ) { |
| 494 |
$dark = ( abs( $dr ) === 2 || abs( $dc ) === 2 || ( 0 === $dr && 0 === $dc ) ); |
| 495 |
$this->set_module( $r + $dr, $c + $dc, $dark, true ); |
| 496 |
} |
| 497 |
} |
| 498 |
} |
| 499 |
} |
| 500 |
|
| 501 |
/** |
| 502 |
* Place timing patterns |
| 503 |
*/ |
| 504 |
private function place_timing_patterns() { |
| 505 |
for ( $i = 8; $i < $this->size - 8; $i++ ) { |
| 506 |
if ( ! $this->reserved[ 6 ][ $i ] ) { |
| 507 |
$this->set_module( 6, $i, 0 === $i % 2, true ); |
| 508 |
} |
| 509 |
if ( ! $this->reserved[ $i ][ 6 ] ) { |
| 510 |
$this->set_module( $i, 6, 0 === $i % 2, true ); |
| 511 |
} |
| 512 |
} |
| 513 |
} |
| 514 |
|
| 515 |
/** |
| 516 |
* Reserve format information area |
| 517 |
*/ |
| 518 |
private function reserve_format_area() { |
| 519 |
// Around top-left finder |
| 520 |
for ( $i = 0; $i <= 8; $i++ ) { |
| 521 |
if ( $i !== 6 ) { |
| 522 |
$this->reserve( 8, $i ); |
| 523 |
} |
| 524 |
if ( $i !== 6 && $i < 8 ) { |
| 525 |
$this->reserve( $i, 8 ); |
| 526 |
} |
| 527 |
} |
| 528 |
$this->reserve( 8, 8 ); |
| 529 |
|
| 530 |
// Bottom-left |
| 531 |
for ( $i = $this->size - 7; $i < $this->size; $i++ ) { |
| 532 |
$this->reserve( $i, 8 ); |
| 533 |
} |
| 534 |
|
| 535 |
// Top-right |
| 536 |
for ( $i = $this->size - 8; $i < $this->size; $i++ ) { |
| 537 |
$this->reserve( 8, $i ); |
| 538 |
} |
| 539 |
|
| 540 |
// Dark module |
| 541 |
$this->set_module( $this->size - 8, 8, true, true ); |
| 542 |
} |
| 543 |
|
| 544 |
/** |
| 545 |
* Reserve version information area (version >= 7) |
| 546 |
*/ |
| 547 |
private function reserve_version_area() { |
| 548 |
for ( $i = 0; $i < 6; $i++ ) { |
| 549 |
for ( $j = $this->size - 11; $j < $this->size - 8; $j++ ) { |
| 550 |
$this->reserve( $i, $j ); |
| 551 |
$this->reserve( $j, $i ); |
| 552 |
} |
| 553 |
} |
| 554 |
} |
| 555 |
|
| 556 |
/** |
| 557 |
* Place format information bits |
| 558 |
* |
| 559 |
* @param int $mask Mask pattern (0-7). |
| 560 |
*/ |
| 561 |
private function place_format_info( $mask ) { |
| 562 |
// ECL L = 01, mask pattern 3 bits |
| 563 |
$format_data = ( 1 << 3 ) | $mask; // ECL L = 01 |
| 564 |
$format_ecc = $this->calc_format_ecc( $format_data ); |
| 565 |
$format_bits = ( $format_data << 10 ) | $format_ecc; |
| 566 |
$format_bits ^= 0x5412; // XOR with mask pattern 101010000010010 |
| 567 |
|
| 568 |
// Position sequences for format info |
| 569 |
$positions_a = array( |
| 570 |
array( 0, 8 ), array( 1, 8 ), array( 2, 8 ), array( 3, 8 ), |
| 571 |
array( 4, 8 ), array( 5, 8 ), array( 7, 8 ), array( 8, 8 ), |
| 572 |
array( 8, 7 ), array( 8, 5 ), array( 8, 4 ), array( 8, 3 ), |
| 573 |
array( 8, 2 ), array( 8, 1 ), array( 8, 0 ), |
| 574 |
); |
| 575 |
|
| 576 |
$positions_b = array(); |
| 577 |
for ( $i = $this->size - 1; $i >= $this->size - 7; $i-- ) { |
| 578 |
$positions_b[] = array( 8, $i ); |
| 579 |
} |
| 580 |
$positions_b[] = array( 8, $this->size - 8 ); |
| 581 |
for ( $i = $this->size - 7; $i < $this->size; $i++ ) { |
| 582 |
$positions_b[] = array( $i, 8 ); |
| 583 |
} |
| 584 |
|
| 585 |
for ( $i = 0; $i < 15; $i++ ) { |
| 586 |
$bit = ( $format_bits >> ( 14 - $i ) ) & 1; |
| 587 |
$this->modules[ $positions_a[ $i ][0] ][ $positions_a[ $i ][1] ] = (bool) $bit; |
| 588 |
$this->modules[ $positions_b[ $i ][0] ][ $positions_b[ $i ][1] ] = (bool) $bit; |
| 589 |
} |
| 590 |
} |
| 591 |
|
| 592 |
/** |
| 593 |
* Calculate format ECC (BCH(15,5)) |
| 594 |
* |
| 595 |
* @param int $data 5-bit format data. |
| 596 |
* @return int 10-bit ECC. |
| 597 |
*/ |
| 598 |
private function calc_format_ecc( $data ) { |
| 599 |
$g = 0x537; // Generator polynomial |
| 600 |
$bits = $data << 10; |
| 601 |
for ( $i = 4; $i >= 0; $i-- ) { |
| 602 |
if ( $bits & ( 1 << ( $i + 10 ) ) ) { |
| 603 |
$bits ^= $g << $i; |
| 604 |
} |
| 605 |
} |
| 606 |
return $bits; |
| 607 |
} |
| 608 |
|
| 609 |
/** |
| 610 |
* Place version information bits (version >= 7) |
| 611 |
* |
| 612 |
* @param int $version QR version. |
| 613 |
*/ |
| 614 |
private function place_version_info( $version ) { |
| 615 |
$ver_data = $this->calc_version_ecc( $version ); |
| 616 |
|
| 617 |
for ( $i = 0; $i < 18; $i++ ) { |
| 618 |
$bit = ( $ver_data >> $i ) & 1; |
| 619 |
$r = intval( $i / 3 ); |
| 620 |
$c = $this->size - 11 + ( $i % 3 ); |
| 621 |
$this->modules[ $r ][ $c ] = (bool) $bit; |
| 622 |
$this->modules[ $c ][ $r ] = (bool) $bit; |
| 623 |
} |
| 624 |
} |
| 625 |
|
| 626 |
/** |
| 627 |
* Calculate version ECC (BCH(18,6)) |
| 628 |
* |
| 629 |
* @param int $version Version number. |
| 630 |
* @return int 18-bit version info. |
| 631 |
*/ |
| 632 |
private function calc_version_ecc( $version ) { |
| 633 |
$g = 0x1F25; // Generator polynomial |
| 634 |
$bits = $version << 12; |
| 635 |
$tmp = $bits; |
| 636 |
for ( $i = 5; $i >= 0; $i-- ) { |
| 637 |
if ( $tmp & ( 1 << ( $i + 12 ) ) ) { |
| 638 |
$tmp ^= $g << $i; |
| 639 |
} |
| 640 |
} |
| 641 |
return $bits | $tmp; |
| 642 |
} |
| 643 |
|
| 644 |
/** |
| 645 |
* Place data bits in zigzag pattern |
| 646 |
* |
| 647 |
* @param array $codewords Data and EC codewords. |
| 648 |
*/ |
| 649 |
private function place_data_bits( $codewords ) { |
| 650 |
$bits = ''; |
| 651 |
foreach ( $codewords as $cw ) { |
| 652 |
$bits .= str_pad( decbin( $cw ), 8, '0', STR_PAD_LEFT ); |
| 653 |
} |
| 654 |
|
| 655 |
$bit_idx = 0; |
| 656 |
$col = $this->size - 1; |
| 657 |
|
| 658 |
while ( $col > 0 ) { |
| 659 |
// Skip vertical timing pattern column |
| 660 |
if ( 6 === $col ) { |
| 661 |
$col--; |
| 662 |
} |
| 663 |
|
| 664 |
for ( $row = 0; $row < $this->size; $row++ ) { |
| 665 |
// Determine actual row based on direction |
| 666 |
$upward = ( ( ( $this->size - 1 - $col ) >> 1 ) & 1 ) === 0; |
| 667 |
$actual_row = $upward ? $this->size - 1 - $row : $row; |
| 668 |
|
| 669 |
for ( $c_offset = 0; $c_offset <= 1; $c_offset++ ) { |
| 670 |
$actual_col = $col - $c_offset; |
| 671 |
|
| 672 |
if ( $actual_col < 0 || $actual_col >= $this->size ) { |
| 673 |
continue; |
| 674 |
} |
| 675 |
|
| 676 |
if ( $this->reserved[ $actual_row ][ $actual_col ] ) { |
| 677 |
continue; |
| 678 |
} |
| 679 |
|
| 680 |
if ( $bit_idx < strlen( $bits ) ) { |
| 681 |
$this->modules[ $actual_row ][ $actual_col ] = '1' === $bits[ $bit_idx ]; |
| 682 |
$bit_idx++; |
| 683 |
} else { |
| 684 |
$this->modules[ $actual_row ][ $actual_col ] = false; |
| 685 |
} |
| 686 |
} |
| 687 |
} |
| 688 |
|
| 689 |
$col -= 2; |
| 690 |
} |
| 691 |
} |
| 692 |
|
| 693 |
/** |
| 694 |
* Apply best mask pattern |
| 695 |
* |
| 696 |
* @return int Best mask index (0-7). |
| 697 |
*/ |
| 698 |
private function apply_best_mask() { |
| 699 |
$best_mask = 0; |
| 700 |
$best_penalty = PHP_INT_MAX; |
| 701 |
$original = $this->modules; |
| 702 |
|
| 703 |
for ( $mask = 0; $mask < 8; $mask++ ) { |
| 704 |
$this->modules = $this->deep_copy( $original ); |
| 705 |
$this->apply_mask( $mask ); |
| 706 |
$this->place_format_info( $mask ); |
| 707 |
|
| 708 |
$penalty = $this->calc_penalty(); |
| 709 |
|
| 710 |
if ( $penalty < $best_penalty ) { |
| 711 |
$best_penalty = $penalty; |
| 712 |
$best_mask = $mask; |
| 713 |
} |
| 714 |
} |
| 715 |
|
| 716 |
// Apply the best mask |
| 717 |
$this->modules = $this->deep_copy( $original ); |
| 718 |
$this->apply_mask( $best_mask ); |
| 719 |
|
| 720 |
return $best_mask; |
| 721 |
} |
| 722 |
|
| 723 |
/** |
| 724 |
* Apply a specific mask pattern to data modules |
| 725 |
* |
| 726 |
* @param int $mask Mask index (0-7). |
| 727 |
*/ |
| 728 |
private function apply_mask( $mask ) { |
| 729 |
for ( $r = 0; $r < $this->size; $r++ ) { |
| 730 |
for ( $c = 0; $c < $this->size; $c++ ) { |
| 731 |
if ( $this->reserved[ $r ][ $c ] ) { |
| 732 |
continue; |
| 733 |
} |
| 734 |
$invert = false; |
| 735 |
switch ( $mask ) { |
| 736 |
case 0: |
| 737 |
$invert = ( ( $r + $c ) % 2 === 0 ); |
| 738 |
break; |
| 739 |
case 1: |
| 740 |
$invert = ( $r % 2 === 0 ); |
| 741 |
break; |
| 742 |
case 2: |
| 743 |
$invert = ( $c % 3 === 0 ); |
| 744 |
break; |
| 745 |
case 3: |
| 746 |
$invert = ( ( $r + $c ) % 3 === 0 ); |
| 747 |
break; |
| 748 |
case 4: |
| 749 |
$invert = ( ( intval( $r / 2 ) + intval( $c / 3 ) ) % 2 === 0 ); |
| 750 |
break; |
| 751 |
case 5: |
| 752 |
$invert = ( ( ( $r * $c ) % 2 ) + ( ( $r * $c ) % 3 ) === 0 ); |
| 753 |
break; |
| 754 |
case 6: |
| 755 |
$invert = ( ( ( ( $r * $c ) % 2 ) + ( ( $r * $c ) % 3 ) ) % 2 === 0 ); |
| 756 |
break; |
| 757 |
case 7: |
| 758 |
$invert = ( ( ( ( $r + $c ) % 2 ) + ( ( $r * $c ) % 3 ) ) % 2 === 0 ); |
| 759 |
break; |
| 760 |
} |
| 761 |
if ( $invert ) { |
| 762 |
$this->modules[ $r ][ $c ] = ! $this->modules[ $r ][ $c ]; |
| 763 |
} |
| 764 |
} |
| 765 |
} |
| 766 |
} |
| 767 |
|
| 768 |
/** |
| 769 |
* Calculate penalty score for current matrix |
| 770 |
* |
| 771 |
* Simplified: evaluates rule 1 (runs) and rule 3 (finder-like patterns) |
| 772 |
* |
| 773 |
* @return int Penalty score. |
| 774 |
*/ |
| 775 |
private function calc_penalty() { |
| 776 |
$penalty = 0; |
| 777 |
$n = $this->size; |
| 778 |
|
| 779 |
// Rule 1: Adjacent modules in row/column of same color (>=5) |
| 780 |
for ( $r = 0; $r < $n; $r++ ) { |
| 781 |
$run_len = 1; |
| 782 |
for ( $c = 1; $c < $n; $c++ ) { |
| 783 |
if ( $this->modules[ $r ][ $c ] === $this->modules[ $r ][ $c - 1 ] ) { |
| 784 |
$run_len++; |
| 785 |
} else { |
| 786 |
if ( $run_len >= 5 ) { |
| 787 |
$penalty += $run_len - 2; |
| 788 |
} |
| 789 |
$run_len = 1; |
| 790 |
} |
| 791 |
} |
| 792 |
if ( $run_len >= 5 ) { |
| 793 |
$penalty += $run_len - 2; |
| 794 |
} |
| 795 |
} |
| 796 |
|
| 797 |
for ( $c = 0; $c < $n; $c++ ) { |
| 798 |
$run_len = 1; |
| 799 |
for ( $r = 1; $r < $n; $r++ ) { |
| 800 |
if ( $this->modules[ $r ][ $c ] === $this->modules[ $r - 1 ][ $c ] ) { |
| 801 |
$run_len++; |
| 802 |
} else { |
| 803 |
if ( $run_len >= 5 ) { |
| 804 |
$penalty += $run_len - 2; |
| 805 |
} |
| 806 |
$run_len = 1; |
| 807 |
} |
| 808 |
} |
| 809 |
if ( $run_len >= 5 ) { |
| 810 |
$penalty += $run_len - 2; |
| 811 |
} |
| 812 |
} |
| 813 |
|
| 814 |
// Rule 2: 2x2 blocks of same color |
| 815 |
for ( $r = 0; $r < $n - 1; $r++ ) { |
| 816 |
for ( $c = 0; $c < $n - 1; $c++ ) { |
| 817 |
$val = $this->modules[ $r ][ $c ]; |
| 818 |
if ( $val === $this->modules[ $r ][ $c + 1 ] |
| 819 |
&& $val === $this->modules[ $r + 1 ][ $c ] |
| 820 |
&& $val === $this->modules[ $r + 1 ][ $c + 1 ] ) { |
| 821 |
$penalty += 3; |
| 822 |
} |
| 823 |
} |
| 824 |
} |
| 825 |
|
| 826 |
// Rule 4: Proportion of dark modules |
| 827 |
$dark = 0; |
| 828 |
for ( $r = 0; $r < $n; $r++ ) { |
| 829 |
for ( $c = 0; $c < $n; $c++ ) { |
| 830 |
if ( $this->modules[ $r ][ $c ] ) { |
| 831 |
$dark++; |
| 832 |
} |
| 833 |
} |
| 834 |
} |
| 835 |
$total = $n * $n; |
| 836 |
$percent = ( $dark * 100 ) / $total; |
| 837 |
$prev_five = intval( $percent / 5 ) * 5; |
| 838 |
$next_five = $prev_five + 5; |
| 839 |
$penalty += min( abs( $prev_five - 50 ), abs( $next_five - 50 ) ) * 2; |
| 840 |
|
| 841 |
return $penalty; |
| 842 |
} |
| 843 |
|
| 844 |
/** |
| 845 |
* Render the QR matrix as SVG markup |
| 846 |
* |
| 847 |
* @param int $px_size Pixel size per module. |
| 848 |
* @param int $margin Quiet zone in modules. |
| 849 |
* @return string SVG markup. |
| 850 |
*/ |
| 851 |
private function render_svg( $px_size, $margin ) { |
| 852 |
$total = ( $this->size + $margin * 2 ) * $px_size; |
| 853 |
|
| 854 |
$svg = '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 ' . $total . ' ' . $total . '" width="' . $total . '" height="' . $total . '">'; |
| 855 |
$svg .= '<rect width="100%" height="100%" fill="#ffffff"/>'; |
| 856 |
$svg .= '<path d="'; |
| 857 |
|
| 858 |
for ( $r = 0; $r < $this->size; $r++ ) { |
| 859 |
for ( $c = 0; $c < $this->size; $c++ ) { |
| 860 |
if ( $this->modules[ $r ][ $c ] ) { |
| 861 |
$x = ( $c + $margin ) * $px_size; |
| 862 |
$y = ( $r + $margin ) * $px_size; |
| 863 |
$svg .= 'M' . $x . ',' . $y . 'h' . $px_size . 'v' . $px_size . 'h-' . $px_size . 'z'; |
| 864 |
} |
| 865 |
} |
| 866 |
} |
| 867 |
|
| 868 |
$svg .= '" fill="#000000"/>'; |
| 869 |
$svg .= '</svg>'; |
| 870 |
|
| 871 |
return $svg; |
| 872 |
} |
| 873 |
|
| 874 |
/** |
| 875 |
* Set a module value and optionally mark as reserved |
| 876 |
* |
| 877 |
* @param int $row Row index. |
| 878 |
* @param int $col Column index. |
| 879 |
* @param bool $dark True for dark module. |
| 880 |
* @param bool $reserved Mark as function pattern. |
| 881 |
*/ |
| 882 |
private function set_module( $row, $col, $dark, $reserved = false ) { |
| 883 |
if ( $row >= 0 && $row < $this->size && $col >= 0 && $col < $this->size ) { |
| 884 |
$this->modules[ $row ][ $col ] = (bool) $dark; |
| 885 |
if ( $reserved ) { |
| 886 |
$this->reserved[ $row ][ $col ] = true; |
| 887 |
} |
| 888 |
} |
| 889 |
} |
| 890 |
|
| 891 |
/** |
| 892 |
* Reserve a module position without setting value |
| 893 |
* |
| 894 |
* @param int $row Row index. |
| 895 |
* @param int $col Column index. |
| 896 |
*/ |
| 897 |
private function reserve( $row, $col ) { |
| 898 |
if ( $row >= 0 && $row < $this->size && $col >= 0 && $col < $this->size ) { |
| 899 |
$this->reserved[ $row ][ $col ] = true; |
| 900 |
} |
| 901 |
} |
| 902 |
|
| 903 |
/** |
| 904 |
* Deep copy a 2D array |
| 905 |
* |
| 906 |
* @param array $arr Original array. |
| 907 |
* @return array Copy. |
| 908 |
*/ |
| 909 |
private function deep_copy( $arr ) { |
| 910 |
$copy = array(); |
| 911 |
foreach ( $arr as $r => $row ) { |
| 912 |
$copy[ $r ] = $row; // PHP arrays are copied by value |
| 913 |
} |
| 914 |
return $copy; |
| 915 |
} |
| 916 |
} |
| 917 |
|
