1 /*
2 * QR Code generator library (C++)
3 *
4 * Copyright (c) Project Nayuki. (MIT License)
5 * https://www.nayuki.io/page/qr-code-generator-library
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy of
8 * this software and associated documentation files (the "Software"), to deal in
9 * the Software without restriction, including without limitation the rights to
10 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
11 * the Software, and to permit persons to whom the Software is furnished to do so,
12 * subject to the following conditions:
13 * - The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 * - The Software is provided "as is", without warranty of any kind, express or
16 * implied, including but not limited to the warranties of merchantability,
17 * fitness for a particular purpose and noninfringement. In no event shall the
18 * authors or copyright holders be liable for any claim, damages or other
19 * liability, whether in an action of contract, tort or otherwise, arising from,
20 * out of or in connection with the Software or the use or other dealings in the
21 * Software.
22 */
23
24 #include <algorithm>
25 #include <climits>
26 #include <cstddef>
27 #include <cstdlib>
28 #include <sstream>
29 #include <utility>
30 #include "BitBuffer.hpp"
31 #include "QrCode.hpp"
32
33 using std::int8_t;
34 using std::uint8_t;
35 using std::size_t;
36 using std::vector;
37
38
39 namespace qrcodegen {
40
getFormatBits(Ecc ecl)41 int QrCode::getFormatBits(Ecc ecl) {
42 switch (ecl) {
43 case Ecc::LOW : return 1;
44 case Ecc::MEDIUM : return 0;
45 case Ecc::QUARTILE: return 3;
46 case Ecc::HIGH : return 2;
47 default: throw std::logic_error("Assertion error");
48 }
49 }
50
51
encodeText(const char * text,Ecc ecl)52 QrCode QrCode::encodeText(const char *text, Ecc ecl) {
53 vector<QrSegment> segs = QrSegment::makeSegments(text);
54 return encodeSegments(segs, ecl);
55 }
56
57
encodeBinary(const vector<uint8_t> & data,Ecc ecl)58 QrCode QrCode::encodeBinary(const vector<uint8_t> &data, Ecc ecl) {
59 vector<QrSegment> segs{QrSegment::makeBytes(data)};
60 return encodeSegments(segs, ecl);
61 }
62
63
encodeSegments(const vector<QrSegment> & segs,Ecc ecl,int minVersion,int maxVersion,int mask,bool boostEcl)64 QrCode QrCode::encodeSegments(const vector<QrSegment> &segs, Ecc ecl,
65 int minVersion, int maxVersion, int mask, bool boostEcl) {
66 if (!(MIN_VERSION <= minVersion && minVersion <= maxVersion && maxVersion <= MAX_VERSION) || mask < -1 || mask > 7)
67 throw std::invalid_argument("Invalid value");
68
69 // Find the minimal version number to use
70 int version, dataUsedBits;
71 for (version = minVersion; ; version++) {
72 int dataCapacityBits = getNumDataCodewords(version, ecl) * 8; // Number of data bits available
73 dataUsedBits = QrSegment::getTotalBits(segs, version);
74 if (dataUsedBits != -1 && dataUsedBits <= dataCapacityBits)
75 break; // This version number is found to be suitable
76 if (version >= maxVersion) { // All versions in the range could not fit the given data
77 std::ostringstream sb;
78 if (dataUsedBits == -1)
79 sb << "Segment too long";
80 else {
81 sb << "Data length = " << dataUsedBits << " bits, ";
82 sb << "Max capacity = " << dataCapacityBits << " bits";
83 }
84 throw data_too_long(sb.str());
85 }
86 }
87 if (dataUsedBits == -1)
88 throw std::logic_error("Assertion error");
89
90 // Increase the error correction level while the data still fits in the current version number
91 for (Ecc newEcl : vector<Ecc>{Ecc::MEDIUM, Ecc::QUARTILE, Ecc::HIGH}) { // From low to high
92 if (boostEcl && dataUsedBits <= getNumDataCodewords(version, newEcl) * 8)
93 ecl = newEcl;
94 }
95
96 // Concatenate all segments to create the data bit string
97 BitBuffer bb;
98 for (const QrSegment &seg : segs) {
99 bb.appendBits(static_cast<uint32_t>(seg.getMode().getModeBits()), 4);
100 bb.appendBits(static_cast<uint32_t>(seg.getNumChars()), seg.getMode().numCharCountBits(version));
101 bb.insert(bb.end(), seg.getData().begin(), seg.getData().end());
102 }
103 if (bb.size() != static_cast<unsigned int>(dataUsedBits))
104 throw std::logic_error("Assertion error");
105
106 // Add terminator and pad up to a byte if applicable
107 size_t dataCapacityBits = static_cast<size_t>(getNumDataCodewords(version, ecl)) * 8;
108 if (bb.size() > dataCapacityBits)
109 throw std::logic_error("Assertion error");
110 bb.appendBits(0, std::min(4, static_cast<int>(dataCapacityBits - bb.size())));
111 bb.appendBits(0, (8 - static_cast<int>(bb.size() % 8)) % 8);
112 if (bb.size() % 8 != 0)
113 throw std::logic_error("Assertion error");
114
115 // Pad with alternating bytes until data capacity is reached
116 for (uint8_t padByte = 0xEC; bb.size() < dataCapacityBits; padByte ^= 0xEC ^ 0x11)
117 bb.appendBits(padByte, 8);
118
119 // Pack bits into bytes in big endian
120 vector<uint8_t> dataCodewords(bb.size() / 8);
121 for (size_t i = 0; i < bb.size(); i++)
122 dataCodewords[i >> 3] |= (bb.at(i) ? 1 : 0) << (7 - (i & 7));
123
124 // Create the QR Code object
125 return QrCode(version, ecl, dataCodewords, mask);
126 }
127
128
QrCode(int ver,Ecc ecl,const vector<uint8_t> & dataCodewords,int msk)129 QrCode::QrCode(int ver, Ecc ecl, const vector<uint8_t> &dataCodewords, int msk) :
130 // Initialize fields and check arguments
131 version(ver),
132 errorCorrectionLevel(ecl) {
133 if (ver < MIN_VERSION || ver > MAX_VERSION)
134 throw std::domain_error("Version value out of range");
135 if (msk < -1 || msk > 7)
136 throw std::domain_error("Mask value out of range");
137 size = ver * 4 + 17;
138 size_t sz = static_cast<size_t>(size);
139 modules = vector<vector<bool> >(sz, vector<bool>(sz)); // Initially all white
140 isFunction = vector<vector<bool> >(sz, vector<bool>(sz));
141
142 // Compute ECC, draw modules
143 drawFunctionPatterns();
144 const vector<uint8_t> allCodewords = addEccAndInterleave(dataCodewords);
145 drawCodewords(allCodewords);
146
147 // Do masking
148 if (msk == -1) { // Automatically choose best mask
149 long minPenalty = LONG_MAX;
150 for (int i = 0; i < 8; i++) {
151 applyMask(i);
152 drawFormatBits(i);
153 long penalty = getPenaltyScore();
154 if (penalty < minPenalty) {
155 msk = i;
156 minPenalty = penalty;
157 }
158 applyMask(i); // Undoes the mask due to XOR
159 }
160 }
161 if (msk < 0 || msk > 7)
162 throw std::logic_error("Assertion error");
163 this->mask = msk;
164 applyMask(msk); // Apply the final choice of mask
165 drawFormatBits(msk); // Overwrite old format bits
166
167 isFunction.clear();
168 isFunction.shrink_to_fit();
169 }
170
171
getVersion() const172 int QrCode::getVersion() const {
173 return version;
174 }
175
176
getSize() const177 int QrCode::getSize() const {
178 return size;
179 }
180
181
getErrorCorrectionLevel() const182 QrCode::Ecc QrCode::getErrorCorrectionLevel() const {
183 return errorCorrectionLevel;
184 }
185
186
getMask() const187 int QrCode::getMask() const {
188 return mask;
189 }
190
191
getModule(int x,int y) const192 bool QrCode::getModule(int x, int y) const {
193 return 0 <= x && x < size && 0 <= y && y < size && module(x, y);
194 }
195
196
toSvgString(int border) const197 std::string QrCode::toSvgString(int border) const {
198 if (border < 0)
199 throw std::domain_error("Border must be non-negative");
200 if (border > INT_MAX / 2 || border * 2 > INT_MAX - size)
201 throw std::overflow_error("Border too large");
202
203 std::ostringstream sb;
204 sb << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
205 sb << "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n";
206 sb << "<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" viewBox=\"0 0 ";
207 sb << (size + border * 2) << " " << (size + border * 2) << "\" stroke=\"none\">\n";
208 sb << "\t<rect width=\"100%\" height=\"100%\" fill=\"#FFFFFF\"/>\n";
209 sb << "\t<path d=\"";
210 for (int y = 0; y < size; y++) {
211 for (int x = 0; x < size; x++) {
212 if (getModule(x, y)) {
213 if (x != 0 || y != 0)
214 sb << " ";
215 sb << "M" << (x + border) << "," << (y + border) << "h1v1h-1z";
216 }
217 }
218 }
219 sb << "\" fill=\"#000000\"/>\n";
220 sb << "</svg>\n";
221 return sb.str();
222 }
223
224
drawFunctionPatterns()225 void QrCode::drawFunctionPatterns() {
226 // Draw horizontal and vertical timing patterns
227 for (int i = 0; i < size; i++) {
228 setFunctionModule(6, i, i % 2 == 0);
229 setFunctionModule(i, 6, i % 2 == 0);
230 }
231
232 // Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules)
233 drawFinderPattern(3, 3);
234 drawFinderPattern(size - 4, 3);
235 drawFinderPattern(3, size - 4);
236
237 // Draw numerous alignment patterns
238 const vector<int> alignPatPos = getAlignmentPatternPositions();
239 size_t numAlign = alignPatPos.size();
240 for (size_t i = 0; i < numAlign; i++) {
241 for (size_t j = 0; j < numAlign; j++) {
242 // Don't draw on the three finder corners
243 if (!((i == 0 && j == 0) || (i == 0 && j == numAlign - 1) || (i == numAlign - 1 && j == 0)))
244 drawAlignmentPattern(alignPatPos.at(i), alignPatPos.at(j));
245 }
246 }
247
248 // Draw configuration data
249 drawFormatBits(0); // Dummy mask value; overwritten later in the constructor
250 drawVersion();
251 }
252
253
drawFormatBits(int msk)254 void QrCode::drawFormatBits(int msk) {
255 // Calculate error correction code and pack bits
256 int data = getFormatBits(errorCorrectionLevel) << 3 | msk; // errCorrLvl is uint2, msk is uint3
257 int rem = data;
258 for (int i = 0; i < 10; i++)
259 rem = (rem << 1) ^ ((rem >> 9) * 0x537);
260 int bits = (data << 10 | rem) ^ 0x5412; // uint15
261 if (bits >> 15 != 0)
262 throw std::logic_error("Assertion error");
263
264 // Draw first copy
265 for (int i = 0; i <= 5; i++)
266 setFunctionModule(8, i, getBit(bits, i));
267 setFunctionModule(8, 7, getBit(bits, 6));
268 setFunctionModule(8, 8, getBit(bits, 7));
269 setFunctionModule(7, 8, getBit(bits, 8));
270 for (int i = 9; i < 15; i++)
271 setFunctionModule(14 - i, 8, getBit(bits, i));
272
273 // Draw second copy
274 for (int i = 0; i < 8; i++)
275 setFunctionModule(size - 1 - i, 8, getBit(bits, i));
276 for (int i = 8; i < 15; i++)
277 setFunctionModule(8, size - 15 + i, getBit(bits, i));
278 setFunctionModule(8, size - 8, true); // Always black
279 }
280
281
drawVersion()282 void QrCode::drawVersion() {
283 if (version < 7)
284 return;
285
286 // Calculate error correction code and pack bits
287 int rem = version; // version is uint6, in the range [7, 40]
288 for (int i = 0; i < 12; i++)
289 rem = (rem << 1) ^ ((rem >> 11) * 0x1F25);
290 long bits = static_cast<long>(version) << 12 | rem; // uint18
291 if (bits >> 18 != 0)
292 throw std::logic_error("Assertion error");
293
294 // Draw two copies
295 for (int i = 0; i < 18; i++) {
296 bool bit = getBit(bits, i);
297 int a = size - 11 + i % 3;
298 int b = i / 3;
299 setFunctionModule(a, b, bit);
300 setFunctionModule(b, a, bit);
301 }
302 }
303
304
drawFinderPattern(int x,int y)305 void QrCode::drawFinderPattern(int x, int y) {
306 for (int dy = -4; dy <= 4; dy++) {
307 for (int dx = -4; dx <= 4; dx++) {
308 int dist = std::max(std::abs(dx), std::abs(dy)); // Chebyshev/infinity norm
309 int xx = x + dx, yy = y + dy;
310 if (0 <= xx && xx < size && 0 <= yy && yy < size)
311 setFunctionModule(xx, yy, dist != 2 && dist != 4);
312 }
313 }
314 }
315
316
drawAlignmentPattern(int x,int y)317 void QrCode::drawAlignmentPattern(int x, int y) {
318 for (int dy = -2; dy <= 2; dy++) {
319 for (int dx = -2; dx <= 2; dx++)
320 setFunctionModule(x + dx, y + dy, std::max(std::abs(dx), std::abs(dy)) != 1);
321 }
322 }
323
324
setFunctionModule(int x,int y,bool isBlack)325 void QrCode::setFunctionModule(int x, int y, bool isBlack) {
326 size_t ux = static_cast<size_t>(x);
327 size_t uy = static_cast<size_t>(y);
328 modules .at(uy).at(ux) = isBlack;
329 isFunction.at(uy).at(ux) = true;
330 }
331
332
module(int x,int y) const333 bool QrCode::module(int x, int y) const {
334 return modules.at(static_cast<size_t>(y)).at(static_cast<size_t>(x));
335 }
336
337
addEccAndInterleave(const vector<uint8_t> & data) const338 vector<uint8_t> QrCode::addEccAndInterleave(const vector<uint8_t> &data) const {
339 if (data.size() != static_cast<unsigned int>(getNumDataCodewords(version, errorCorrectionLevel)))
340 throw std::invalid_argument("Invalid argument");
341
342 // Calculate parameter numbers
343 int numBlocks = NUM_ERROR_CORRECTION_BLOCKS[static_cast<int>(errorCorrectionLevel)][version];
344 int blockEccLen = ECC_CODEWORDS_PER_BLOCK [static_cast<int>(errorCorrectionLevel)][version];
345 int rawCodewords = getNumRawDataModules(version) / 8;
346 int numShortBlocks = numBlocks - rawCodewords % numBlocks;
347 int shortBlockLen = rawCodewords / numBlocks;
348
349 // Split data into blocks and append ECC to each block
350 vector<vector<uint8_t> > blocks;
351 const vector<uint8_t> rsDiv = reedSolomonComputeDivisor(blockEccLen);
352 for (int i = 0, k = 0; i < numBlocks; i++) {
353 vector<uint8_t> dat(data.cbegin() + k, data.cbegin() + (k + shortBlockLen - blockEccLen + (i < numShortBlocks ? 0 : 1)));
354 k += static_cast<int>(dat.size());
355 const vector<uint8_t> ecc = reedSolomonComputeRemainder(dat, rsDiv);
356 if (i < numShortBlocks)
357 dat.push_back(0);
358 dat.insert(dat.end(), ecc.cbegin(), ecc.cend());
359 blocks.push_back(std::move(dat));
360 }
361
362 // Interleave (not concatenate) the bytes from every block into a single sequence
363 vector<uint8_t> result;
364 for (size_t i = 0; i < blocks.at(0).size(); i++) {
365 for (size_t j = 0; j < blocks.size(); j++) {
366 // Skip the padding byte in short blocks
367 if (i != static_cast<unsigned int>(shortBlockLen - blockEccLen) || j >= static_cast<unsigned int>(numShortBlocks))
368 result.push_back(blocks.at(j).at(i));
369 }
370 }
371 if (result.size() != static_cast<unsigned int>(rawCodewords))
372 throw std::logic_error("Assertion error");
373 return result;
374 }
375
376
drawCodewords(const vector<uint8_t> & data)377 void QrCode::drawCodewords(const vector<uint8_t> &data) {
378 if (data.size() != static_cast<unsigned int>(getNumRawDataModules(version) / 8))
379 throw std::invalid_argument("Invalid argument");
380
381 size_t i = 0; // Bit index into the data
382 // Do the funny zigzag scan
383 for (int right = size - 1; right >= 1; right -= 2) { // Index of right column in each column pair
384 if (right == 6)
385 right = 5;
386 for (int vert = 0; vert < size; vert++) { // Vertical counter
387 for (int j = 0; j < 2; j++) {
388 size_t x = static_cast<size_t>(right - j); // Actual x coordinate
389 bool upward = ((right + 1) & 2) == 0;
390 size_t y = static_cast<size_t>(upward ? size - 1 - vert : vert); // Actual y coordinate
391 if (!isFunction.at(y).at(x) && i < data.size() * 8) {
392 modules.at(y).at(x) = getBit(data.at(i >> 3), 7 - static_cast<int>(i & 7));
393 i++;
394 }
395 // If this QR Code has any remainder bits (0 to 7), they were assigned as
396 // 0/false/white by the constructor and are left unchanged by this method
397 }
398 }
399 }
400 if (i != data.size() * 8)
401 throw std::logic_error("Assertion error");
402 }
403
404
applyMask(int msk)405 void QrCode::applyMask(int msk) {
406 if (msk < 0 || msk > 7)
407 throw std::domain_error("Mask value out of range");
408 size_t sz = static_cast<size_t>(size);
409 for (size_t y = 0; y < sz; y++) {
410 for (size_t x = 0; x < sz; x++) {
411 bool invert;
412 switch (msk) {
413 case 0: invert = (x + y) % 2 == 0; break;
414 case 1: invert = y % 2 == 0; break;
415 case 2: invert = x % 3 == 0; break;
416 case 3: invert = (x + y) % 3 == 0; break;
417 case 4: invert = (x / 3 + y / 2) % 2 == 0; break;
418 case 5: invert = x * y % 2 + x * y % 3 == 0; break;
419 case 6: invert = (x * y % 2 + x * y % 3) % 2 == 0; break;
420 case 7: invert = ((x + y) % 2 + x * y % 3) % 2 == 0; break;
421 default: throw std::logic_error("Assertion error");
422 }
423 modules.at(y).at(x) = modules.at(y).at(x) ^ (invert & !isFunction.at(y).at(x));
424 }
425 }
426 }
427
428
getPenaltyScore() const429 long QrCode::getPenaltyScore() const {
430 long result = 0;
431
432 // Adjacent modules in row having same color, and finder-like patterns
433 for (int y = 0; y < size; y++) {
434 bool runColor = false;
435 int runX = 0;
436 std::array<int,7> runHistory = {};
437 int padRun = size; // Add white border to initial run
438 for (int x = 0; x < size; x++) {
439 if (module(x, y) == runColor) {
440 runX++;
441 if (runX == 5)
442 result += PENALTY_N1;
443 else if (runX > 5)
444 result++;
445 } else {
446 finderPenaltyAddHistory(runX + padRun, runHistory);
447 padRun = 0;
448 if (!runColor)
449 result += finderPenaltyCountPatterns(runHistory) * PENALTY_N3;
450 runColor = module(x, y);
451 runX = 1;
452 }
453 }
454 result += finderPenaltyTerminateAndCount(runColor, runX + padRun, runHistory) * PENALTY_N3;
455 }
456 // Adjacent modules in column having same color, and finder-like patterns
457 for (int x = 0; x < size; x++) {
458 bool runColor = false;
459 int runY = 0;
460 std::array<int,7> runHistory = {};
461 int padRun = size; // Add white border to initial run
462 for (int y = 0; y < size; y++) {
463 if (module(x, y) == runColor) {
464 runY++;
465 if (runY == 5)
466 result += PENALTY_N1;
467 else if (runY > 5)
468 result++;
469 } else {
470 finderPenaltyAddHistory(runY + padRun, runHistory);
471 padRun = 0;
472 if (!runColor)
473 result += finderPenaltyCountPatterns(runHistory) * PENALTY_N3;
474 runColor = module(x, y);
475 runY = 1;
476 }
477 }
478 result += finderPenaltyTerminateAndCount(runColor, runY + padRun, runHistory) * PENALTY_N3;
479 }
480
481 // 2*2 blocks of modules having same color
482 for (int y = 0; y < size - 1; y++) {
483 for (int x = 0; x < size - 1; x++) {
484 bool color = module(x, y);
485 if ( color == module(x + 1, y) &&
486 color == module(x, y + 1) &&
487 color == module(x + 1, y + 1))
488 result += PENALTY_N2;
489 }
490 }
491
492 // Balance of black and white modules
493 int black = 0;
494 for (const vector<bool> &row : modules) {
495 for (bool color : row) {
496 if (color)
497 black++;
498 }
499 }
500 int total = size * size; // Note that size is odd, so black/total != 1/2
501 // Compute the smallest integer k >= 0 such that (45-5k)% <= black/total <= (55+5k)%
502 int k = static_cast<int>((std::abs(black * 20L - total * 10L) + total - 1) / total) - 1;
503 result += k * PENALTY_N4;
504 return result;
505 }
506
507
getAlignmentPatternPositions() const508 vector<int> QrCode::getAlignmentPatternPositions() const {
509 if (version == 1)
510 return vector<int>();
511 else {
512 int numAlign = version / 7 + 2;
513 int step = (version == 32) ? 26 :
514 (version*4 + numAlign*2 + 1) / (numAlign*2 - 2) * 2;
515 vector<int> result;
516 for (int i = 0, pos = size - 7; i < numAlign - 1; i++, pos -= step)
517 result.insert(result.begin(), pos);
518 result.insert(result.begin(), 6);
519 return result;
520 }
521 }
522
523
getNumRawDataModules(int ver)524 int QrCode::getNumRawDataModules(int ver) {
525 if (ver < MIN_VERSION || ver > MAX_VERSION)
526 throw std::domain_error("Version number out of range");
527 int result = (16 * ver + 128) * ver + 64;
528 if (ver >= 2) {
529 int numAlign = ver / 7 + 2;
530 result -= (25 * numAlign - 10) * numAlign - 55;
531 if (ver >= 7)
532 result -= 36;
533 }
534 if (!(208 <= result && result <= 29648))
535 throw std::logic_error("Assertion error");
536 return result;
537 }
538
539
getNumDataCodewords(int ver,Ecc ecl)540 int QrCode::getNumDataCodewords(int ver, Ecc ecl) {
541 return getNumRawDataModules(ver) / 8
542 - ECC_CODEWORDS_PER_BLOCK [static_cast<int>(ecl)][ver]
543 * NUM_ERROR_CORRECTION_BLOCKS[static_cast<int>(ecl)][ver];
544 }
545
546
reedSolomonComputeDivisor(int degree)547 vector<uint8_t> QrCode::reedSolomonComputeDivisor(int degree) {
548 if (degree < 1 || degree > 255)
549 throw std::domain_error("Degree out of range");
550 // Polynomial coefficients are stored from highest to lowest power, excluding the leading term which is always 1.
551 // For example the polynomial x^3 + 255x^2 + 8x + 93 is stored as the uint8 array {255, 8, 93}.
552 vector<uint8_t> result(static_cast<size_t>(degree));
553 result.at(result.size() - 1) = 1; // Start off with the monomial x^0
554
555 // Compute the product polynomial (x - r^0) * (x - r^1) * (x - r^2) * ... * (x - r^{degree-1}),
556 // and drop the highest monomial term which is always 1x^degree.
557 // Note that r = 0x02, which is a generator element of this field GF(2^8/0x11D).
558 uint8_t root = 1;
559 for (int i = 0; i < degree; i++) {
560 // Multiply the current product by (x - r^i)
561 for (size_t j = 0; j < result.size(); j++) {
562 result.at(j) = reedSolomonMultiply(result.at(j), root);
563 if (j + 1 < result.size())
564 result.at(j) ^= result.at(j + 1);
565 }
566 root = reedSolomonMultiply(root, 0x02);
567 }
568 return result;
569 }
570
571
reedSolomonComputeRemainder(const vector<uint8_t> & data,const vector<uint8_t> & divisor)572 vector<uint8_t> QrCode::reedSolomonComputeRemainder(const vector<uint8_t> &data, const vector<uint8_t> &divisor) {
573 vector<uint8_t> result(divisor.size());
574 for (uint8_t b : data) { // Polynomial division
575 uint8_t factor = b ^ result.at(0);
576 result.erase(result.begin());
577 result.push_back(0);
578 for (size_t i = 0; i < result.size(); i++)
579 result.at(i) ^= reedSolomonMultiply(divisor.at(i), factor);
580 }
581 return result;
582 }
583
584
reedSolomonMultiply(uint8_t x,uint8_t y)585 uint8_t QrCode::reedSolomonMultiply(uint8_t x, uint8_t y) {
586 // Russian peasant multiplication
587 int z = 0;
588 for (int i = 7; i >= 0; i--) {
589 z = (z << 1) ^ ((z >> 7) * 0x11D);
590 z ^= ((y >> i) & 1) * x;
591 }
592 if (z >> 8 != 0)
593 throw std::logic_error("Assertion error");
594 return static_cast<uint8_t>(z);
595 }
596
597
finderPenaltyCountPatterns(const std::array<int,7> & runHistory) const598 int QrCode::finderPenaltyCountPatterns(const std::array<int,7> &runHistory) const {
599 int n = runHistory.at(1);
600 if (n > size * 3)
601 throw std::logic_error("Assertion error");
602 bool core = n > 0 && runHistory.at(2) == n && runHistory.at(3) == n * 3 && runHistory.at(4) == n && runHistory.at(5) == n;
603 return (core && runHistory.at(0) >= n * 4 && runHistory.at(6) >= n ? 1 : 0)
604 + (core && runHistory.at(6) >= n * 4 && runHistory.at(0) >= n ? 1 : 0);
605 }
606
607
finderPenaltyTerminateAndCount(bool currentRunColor,int currentRunLength,std::array<int,7> & runHistory) const608 int QrCode::finderPenaltyTerminateAndCount(bool currentRunColor, int currentRunLength, std::array<int,7> &runHistory) const {
609 if (currentRunColor) { // Terminate black run
610 finderPenaltyAddHistory(currentRunLength, runHistory);
611 currentRunLength = 0;
612 }
613 currentRunLength += size; // Add white border to final run
614 finderPenaltyAddHistory(currentRunLength, runHistory);
615 return finderPenaltyCountPatterns(runHistory);
616 }
617
618
finderPenaltyAddHistory(int currentRunLength,std::array<int,7> & runHistory)619 void QrCode::finderPenaltyAddHistory(int currentRunLength, std::array<int,7> &runHistory) {
620 std::copy_backward(runHistory.cbegin(), runHistory.cend() - 1, runHistory.end());
621 runHistory.at(0) = currentRunLength;
622 }
623
624
getBit(long x,int i)625 bool QrCode::getBit(long x, int i) {
626 return ((x >> i) & 1) != 0;
627 }
628
629
630 /*---- Tables of constants ----*/
631
632 const int QrCode::PENALTY_N1 = 3;
633 const int QrCode::PENALTY_N2 = 3;
634 const int QrCode::PENALTY_N3 = 40;
635 const int QrCode::PENALTY_N4 = 10;
636
637
638 const int8_t QrCode::ECC_CODEWORDS_PER_BLOCK[4][41] = {
639 // Version: (note that index 0 is for padding, and is set to an illegal value)
640 //0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 Error correction level
641 {-1, 7, 10, 15, 20, 26, 18, 20, 24, 30, 18, 20, 24, 26, 30, 22, 24, 28, 30, 28, 28, 28, 28, 30, 30, 26, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30}, // Low
642 {-1, 10, 16, 26, 18, 24, 16, 18, 22, 22, 26, 30, 22, 22, 24, 24, 28, 28, 26, 26, 26, 26, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28}, // Medium
643 {-1, 13, 22, 18, 26, 18, 24, 18, 22, 20, 24, 28, 26, 24, 20, 30, 24, 28, 28, 26, 30, 28, 30, 30, 30, 30, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30}, // Quartile
644 {-1, 17, 28, 22, 16, 22, 28, 26, 26, 24, 28, 24, 28, 22, 24, 24, 30, 28, 28, 26, 28, 30, 24, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30}, // High
645 };
646
647 const int8_t QrCode::NUM_ERROR_CORRECTION_BLOCKS[4][41] = {
648 // Version: (note that index 0 is for padding, and is set to an illegal value)
649 //0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 Error correction level
650 {-1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 4, 4, 6, 6, 6, 6, 7, 8, 8, 9, 9, 10, 12, 12, 12, 13, 14, 15, 16, 17, 18, 19, 19, 20, 21, 22, 24, 25}, // Low
651 {-1, 1, 1, 1, 2, 2, 4, 4, 4, 5, 5, 5, 8, 9, 9, 10, 10, 11, 13, 14, 16, 17, 17, 18, 20, 21, 23, 25, 26, 28, 29, 31, 33, 35, 37, 38, 40, 43, 45, 47, 49}, // Medium
652 {-1, 1, 1, 2, 2, 4, 4, 6, 6, 8, 8, 8, 10, 12, 16, 12, 17, 16, 18, 21, 20, 23, 23, 25, 27, 29, 34, 34, 35, 38, 40, 43, 45, 48, 51, 53, 56, 59, 62, 65, 68}, // Quartile
653 {-1, 1, 1, 2, 4, 4, 4, 5, 6, 8, 8, 11, 11, 16, 16, 18, 16, 19, 21, 25, 25, 25, 34, 30, 32, 35, 37, 40, 42, 45, 48, 51, 54, 57, 60, 63, 66, 70, 74, 77, 81}, // High
654 };
655
656
data_too_long(const std::string & msg)657 data_too_long::data_too_long(const std::string &msg) :
658 std::length_error(msg) {}
659
660 }
661