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/* | |
* QR Code generator library (C++) | |
* | |
* Copyright (c) Project Nayuki. (MIT License) | |
* https://www.nayuki.io/page/qr-code-generator-library | |
* | |
* Permission is hereby granted, free of charge, to any person obtaining a copy of | |
* this software and associated documentation files (the "Software"), to deal in | |
* the Software without restriction, including without limitation the rights to | |
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of | |
* the Software, and to permit persons to whom the Software is furnished to do so, | |
* subject to the following conditions: | |
* - The above copyright notice and this permission notice shall be included in | |
* all copies or substantial portions of the Software. | |
* - The Software is provided "as is", without warranty of any kind, express or | |
* implied, including but not limited to the warranties of merchantability, | |
* fitness for a particular purpose and noninfringement. In no event shall the | |
* authors or copyright holders be liable for any claim, damages or other | |
* liability, whether in an action of contract, tort or otherwise, arising from, | |
* out of or in connection with the Software or the use or other dealings in the | |
* Software. | |
*/ | |
#include <algorithm> | |
#include <climits> | |
#include <cstddef> | |
#include <cstdlib> | |
#include <cstring> | |
#include <sstream> | |
#include <stdexcept> | |
#include <utility> | |
#include "QrCode.hpp" | |
using std::int8_t; | |
using std::uint8_t; | |
using std::size_t; | |
using std::vector; | |
namespace qrcodegen { | |
QrSegment::Mode::Mode(int mode, int cc0, int cc1, int cc2) : | |
modeBits(mode) { | |
numBitsCharCount[0] = cc0; | |
numBitsCharCount[1] = cc1; | |
numBitsCharCount[2] = cc2; | |
} | |
int QrSegment::Mode::getModeBits() const { | |
return modeBits; | |
} | |
int QrSegment::Mode::numCharCountBits(int ver) const { | |
return numBitsCharCount[(ver + 7) / 17]; | |
} | |
const QrSegment::Mode QrSegment::Mode::NUMERIC (0x1, 10, 12, 14); | |
const QrSegment::Mode QrSegment::Mode::ALPHANUMERIC(0x2, 9, 11, 13); | |
const QrSegment::Mode QrSegment::Mode::BYTE (0x4, 8, 16, 16); | |
const QrSegment::Mode QrSegment::Mode::KANJI (0x8, 8, 10, 12); | |
const QrSegment::Mode QrSegment::Mode::ECI (0x7, 0, 0, 0); | |
QrSegment QrSegment::makeBytes(const vector<uint8_t> &data) { | |
if (data.size() > static_cast<unsigned int>(INT_MAX)) | |
throw std::length_error("Data too long"); | |
BitBuffer bb; | |
for (uint8_t b : data) | |
bb.appendBits(b, 8); | |
return QrSegment(Mode::BYTE, static_cast<int>(data.size()), std::move(bb)); | |
} | |
QrSegment QrSegment::makeNumeric(const char *digits) { | |
BitBuffer bb; | |
int accumData = 0; | |
int accumCount = 0; | |
int charCount = 0; | |
for (; *digits != '\0'; digits++, charCount++) { | |
char c = *digits; | |
if (c < '0' || c > '9') | |
throw std::domain_error("String contains non-numeric characters"); | |
accumData = accumData * 10 + (c - '0'); | |
accumCount++; | |
if (accumCount == 3) { | |
bb.appendBits(static_cast<uint32_t>(accumData), 10); | |
accumData = 0; | |
accumCount = 0; | |
} | |
} | |
if (accumCount > 0) // 1 or 2 digits remaining | |
bb.appendBits(static_cast<uint32_t>(accumData), accumCount * 3 + 1); | |
return QrSegment(Mode::NUMERIC, charCount, std::move(bb)); | |
} | |
QrSegment QrSegment::makeAlphanumeric(const char *text) { | |
BitBuffer bb; | |
int accumData = 0; | |
int accumCount = 0; | |
int charCount = 0; | |
for (; *text != '\0'; text++, charCount++) { | |
const char *temp = std::strchr(ALPHANUMERIC_CHARSET, *text); | |
if (temp == nullptr) | |
throw std::domain_error("String contains unencodable characters in alphanumeric mode"); | |
accumData = accumData * 45 + static_cast<int>(temp - ALPHANUMERIC_CHARSET); | |
accumCount++; | |
if (accumCount == 2) { | |
bb.appendBits(static_cast<uint32_t>(accumData), 11); | |
accumData = 0; | |
accumCount = 0; | |
} | |
} | |
if (accumCount > 0) // 1 character remaining | |
bb.appendBits(static_cast<uint32_t>(accumData), 6); | |
return QrSegment(Mode::ALPHANUMERIC, charCount, std::move(bb)); | |
} | |
vector<QrSegment> QrSegment::makeSegments(const char *text) { | |
// Select the most efficient segment encoding automatically | |
vector<QrSegment> result; | |
if (*text == '\0'); // Leave result empty | |
else if (isNumeric(text)) | |
result.push_back(makeNumeric(text)); | |
else if (isAlphanumeric(text)) | |
result.push_back(makeAlphanumeric(text)); | |
else { | |
vector<uint8_t> bytes; | |
for (; *text != '\0'; text++) | |
bytes.push_back(static_cast<uint8_t>(*text)); | |
result.push_back(makeBytes(bytes)); | |
} | |
return result; | |
} | |
QrSegment QrSegment::makeEci(long assignVal) { | |
BitBuffer bb; | |
if (assignVal < 0) | |
throw std::domain_error("ECI assignment value out of range"); | |
else if (assignVal < (1 << 7)) | |
bb.appendBits(static_cast<uint32_t>(assignVal), 8); | |
else if (assignVal < (1 << 14)) { | |
bb.appendBits(2, 2); | |
bb.appendBits(static_cast<uint32_t>(assignVal), 14); | |
} else if (assignVal < 1000000L) { | |
bb.appendBits(6, 3); | |
bb.appendBits(static_cast<uint32_t>(assignVal), 21); | |
} else | |
throw std::domain_error("ECI assignment value out of range"); | |
return QrSegment(Mode::ECI, 0, std::move(bb)); | |
} | |
QrSegment::QrSegment(Mode md, int numCh, const std::vector<bool> &dt) : | |
mode(md), | |
numChars(numCh), | |
data(dt) { | |
if (numCh < 0) | |
throw std::domain_error("Invalid value"); | |
} | |
QrSegment::QrSegment(Mode md, int numCh, std::vector<bool> &&dt) : | |
mode(md), | |
numChars(numCh), | |
data(std::move(dt)) { | |
if (numCh < 0) | |
throw std::domain_error("Invalid value"); | |
} | |
int QrSegment::getTotalBits(const vector<QrSegment> &segs, int version) { | |
int result = 0; | |
for (const QrSegment &seg : segs) { | |
int ccbits = seg.mode.numCharCountBits(version); | |
if (seg.numChars >= (1L << ccbits)) | |
return -1; // The segment's length doesn't fit the field's bit width | |
if (4 + ccbits > INT_MAX - result) | |
return -1; // The sum will overflow an int type | |
result += 4 + ccbits; | |
if (seg.data.size() > static_cast<unsigned int>(INT_MAX - result)) | |
return -1; // The sum will overflow an int type | |
result += static_cast<int>(seg.data.size()); | |
} | |
return result; | |
} | |
bool QrSegment::isAlphanumeric(const char *text) { | |
for (; *text != '\0'; text++) { | |
if (std::strchr(ALPHANUMERIC_CHARSET, *text) == nullptr) | |
return false; | |
} | |
return true; | |
} | |
bool QrSegment::isNumeric(const char *text) { | |
for (; *text != '\0'; text++) { | |
char c = *text; | |
if (c < '0' || c > '9') | |
return false; | |
} | |
return true; | |
} | |
QrSegment::Mode QrSegment::getMode() const { | |
return mode; | |
} | |
int QrSegment::getNumChars() const { | |
return numChars; | |
} | |
const std::vector<bool> &QrSegment::getData() const { | |
return data; | |
} | |
const char *QrSegment::ALPHANUMERIC_CHARSET = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:"; | |
int QrCode::getFormatBits(Ecc ecl) { | |
switch (ecl) { | |
case Ecc::LOW : return 1; | |
case Ecc::MEDIUM : return 0; | |
case Ecc::QUARTILE: return 3; | |
case Ecc::HIGH : return 2; | |
default: throw std::logic_error("Assertion error"); | |
} | |
} | |
QrCode QrCode::encodeText(const char *text, Ecc ecl) { | |
vector<QrSegment> segs = QrSegment::makeSegments(text); | |
return encodeSegments(segs, ecl); | |
} | |
QrCode QrCode::encodeBinary(const vector<uint8_t> &data, Ecc ecl) { | |
vector<QrSegment> segs{QrSegment::makeBytes(data)}; | |
return encodeSegments(segs, ecl); | |
} | |
QrCode QrCode::encodeSegments(const vector<QrSegment> &segs, Ecc ecl, | |
int minVersion, int maxVersion, int mask, bool boostEcl) { | |
if (!(MIN_VERSION <= minVersion && minVersion <= maxVersion && maxVersion <= MAX_VERSION) || mask < -1 || mask > 7) | |
throw std::invalid_argument("Invalid value"); | |
// Find the minimal version number to use | |
int version, dataUsedBits; | |
for (version = minVersion; ; version++) { | |
int dataCapacityBits = getNumDataCodewords(version, ecl) * 8; // Number of data bits available | |
dataUsedBits = QrSegment::getTotalBits(segs, version); | |
if (dataUsedBits != -1 && dataUsedBits <= dataCapacityBits) | |
break; // This version number is found to be suitable | |
if (version >= maxVersion) { // All versions in the range could not fit the given data | |
std::ostringstream sb; | |
if (dataUsedBits == -1) | |
sb << "Segment too long"; | |
else { | |
sb << "Data length = " << dataUsedBits << " bits, "; | |
sb << "Max capacity = " << dataCapacityBits << " bits"; | |
} | |
throw data_too_long(sb.str()); | |
} | |
} | |
if (dataUsedBits == -1) | |
throw std::logic_error("Assertion error"); | |
// Increase the error correction level while the data still fits in the current version number | |
for (Ecc newEcl : vector<Ecc>{Ecc::MEDIUM, Ecc::QUARTILE, Ecc::HIGH}) { // From low to high | |
if (boostEcl && dataUsedBits <= getNumDataCodewords(version, newEcl) * 8) | |
ecl = newEcl; | |
} | |
// Concatenate all segments to create the data bit string | |
BitBuffer bb; | |
for (const QrSegment &seg : segs) { | |
bb.appendBits(static_cast<uint32_t>(seg.getMode().getModeBits()), 4); | |
bb.appendBits(static_cast<uint32_t>(seg.getNumChars()), seg.getMode().numCharCountBits(version)); | |
bb.insert(bb.end(), seg.getData().begin(), seg.getData().end()); | |
} | |
if (bb.size() != static_cast<unsigned int>(dataUsedBits)) | |
throw std::logic_error("Assertion error"); | |
// Add terminator and pad up to a byte if applicable | |
size_t dataCapacityBits = static_cast<size_t>(getNumDataCodewords(version, ecl)) * 8; | |
if (bb.size() > dataCapacityBits) | |
throw std::logic_error("Assertion error"); | |
bb.appendBits(0, std::min(4, static_cast<int>(dataCapacityBits - bb.size()))); | |
bb.appendBits(0, (8 - static_cast<int>(bb.size() % 8)) % 8); | |
if (bb.size() % 8 != 0) | |
throw std::logic_error("Assertion error"); | |
// Pad with alternating bytes until data capacity is reached | |
for (uint8_t padByte = 0xEC; bb.size() < dataCapacityBits; padByte ^= 0xEC ^ 0x11) | |
bb.appendBits(padByte, 8); | |
// Pack bits into bytes in big endian | |
vector<uint8_t> dataCodewords(bb.size() / 8); | |
for (size_t i = 0; i < bb.size(); i++) | |
dataCodewords[i >> 3] |= (bb.at(i) ? 1 : 0) << (7 - (i & 7)); | |
// Create the QR Code object | |
return QrCode(version, ecl, dataCodewords, mask); | |
} | |
QrCode::QrCode(int ver, Ecc ecl, const vector<uint8_t> &dataCodewords, int msk) : | |
// Initialize fields and check arguments | |
version(ver), | |
errorCorrectionLevel(ecl) { | |
if (ver < MIN_VERSION || ver > MAX_VERSION) | |
throw std::domain_error("Version value out of range"); | |
if (msk < -1 || msk > 7) | |
throw std::domain_error("Mask value out of range"); | |
size = ver * 4 + 17; | |
size_t sz = static_cast<size_t>(size); | |
modules = vector<vector<bool> >(sz, vector<bool>(sz)); // Initially all white | |
isFunction = vector<vector<bool> >(sz, vector<bool>(sz)); | |
// Compute ECC, draw modules | |
drawFunctionPatterns(); | |
const vector<uint8_t> allCodewords = addEccAndInterleave(dataCodewords); | |
drawCodewords(allCodewords); | |
// Do masking | |
if (msk == -1) { // Automatically choose best mask | |
long minPenalty = LONG_MAX; | |
for (int i = 0; i < 8; i++) { | |
applyMask(i); | |
drawFormatBits(i); | |
long penalty = getPenaltyScore(); | |
if (penalty < minPenalty) { | |
msk = i; | |
minPenalty = penalty; | |
} | |
applyMask(i); // Undoes the mask due to XOR | |
} | |
} | |
if (msk < 0 || msk > 7) | |
throw std::logic_error("Assertion error"); | |
this->mask = msk; | |
applyMask(msk); // Apply the final choice of mask | |
drawFormatBits(msk); // Overwrite old format bits | |
isFunction.clear(); | |
isFunction.shrink_to_fit(); | |
} | |
int QrCode::getVersion() const { | |
return version; | |
} | |
int QrCode::getSize() const { | |
return size; | |
} | |
QrCode::Ecc QrCode::getErrorCorrectionLevel() const { | |
return errorCorrectionLevel; | |
} | |
int QrCode::getMask() const { | |
return mask; | |
} | |
bool QrCode::getModule(int x, int y) const { | |
return 0 <= x && x < size && 0 <= y && y < size && module(x, y); | |
} | |
std::string QrCode::toSvgString(int border) const { | |
if (border < 0) | |
throw std::domain_error("Border must be non-negative"); | |
if (border > INT_MAX / 2 || border * 2 > INT_MAX - size) | |
throw std::overflow_error("Border too large"); | |
std::ostringstream sb; | |
sb << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"; | |
sb << "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n"; | |
sb << "<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" viewBox=\"0 0 "; | |
sb << (size + border * 2) << " " << (size + border * 2) << "\" stroke=\"none\">\n"; | |
sb << "\t<rect width=\"100%\" height=\"100%\" fill=\"#FFFFFF\"/>\n"; | |
sb << "\t<path d=\""; | |
for (int y = 0; y < size; y++) { | |
for (int x = 0; x < size; x++) { | |
if (getModule(x, y)) { | |
if (x != 0 || y != 0) | |
sb << " "; | |
sb << "M" << (x + border) << "," << (y + border) << "h1v1h-1z"; | |
} | |
} | |
} | |
sb << "\" fill=\"#000000\"/>\n"; | |
sb << "</svg>\n"; | |
return sb.str(); | |
} | |
void QrCode::drawFunctionPatterns() { | |
// Draw horizontal and vertical timing patterns | |
for (int i = 0; i < size; i++) { | |
setFunctionModule(6, i, i % 2 == 0); | |
setFunctionModule(i, 6, i % 2 == 0); | |
} | |
// Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules) | |
drawFinderPattern(3, 3); | |
drawFinderPattern(size - 4, 3); | |
drawFinderPattern(3, size - 4); | |
// Draw numerous alignment patterns | |
const vector<int> alignPatPos = getAlignmentPatternPositions(); | |
size_t numAlign = alignPatPos.size(); | |
for (size_t i = 0; i < numAlign; i++) { | |
for (size_t j = 0; j < numAlign; j++) { | |
// Don't draw on the three finder corners | |
if (!((i == 0 && j == 0) || (i == 0 && j == numAlign - 1) || (i == numAlign - 1 && j == 0))) | |
drawAlignmentPattern(alignPatPos.at(i), alignPatPos.at(j)); | |
} | |
} | |
// Draw configuration data | |
drawFormatBits(0); // Dummy mask value; overwritten later in the constructor | |
drawVersion(); | |
} | |
void QrCode::drawFormatBits(int msk) { | |
// Calculate error correction code and pack bits | |
int data = getFormatBits(errorCorrectionLevel) << 3 | msk; // errCorrLvl is uint2, msk is uint3 | |
int rem = data; | |
for (int i = 0; i < 10; i++) | |
rem = (rem << 1) ^ ((rem >> 9) * 0x537); | |
int bits = (data << 10 | rem) ^ 0x5412; // uint15 | |
if (bits >> 15 != 0) | |
throw std::logic_error("Assertion error"); | |
// Draw first copy | |
for (int i = 0; i <= 5; i++) | |
setFunctionModule(8, i, getBit(bits, i)); | |
setFunctionModule(8, 7, getBit(bits, 6)); | |
setFunctionModule(8, 8, getBit(bits, 7)); | |
setFunctionModule(7, 8, getBit(bits, 8)); | |
for (int i = 9; i < 15; i++) | |
setFunctionModule(14 - i, 8, getBit(bits, i)); | |
// Draw second copy | |
for (int i = 0; i < 8; i++) | |
setFunctionModule(size - 1 - i, 8, getBit(bits, i)); | |
for (int i = 8; i < 15; i++) | |
setFunctionModule(8, size - 15 + i, getBit(bits, i)); | |
setFunctionModule(8, size - 8, true); // Always black | |
} | |
void QrCode::drawVersion() { | |
if (version < 7) | |
return; | |
// Calculate error correction code and pack bits | |
int rem = version; // version is uint6, in the range [7, 40] | |
for (int i = 0; i < 12; i++) | |
rem = (rem << 1) ^ ((rem >> 11) * 0x1F25); | |
long bits = static_cast<long>(version) << 12 | rem; // uint18 | |
if (bits >> 18 != 0) | |
throw std::logic_error("Assertion error"); | |
// Draw two copies | |
for (int i = 0; i < 18; i++) { | |
bool bit = getBit(bits, i); | |
int a = size - 11 + i % 3; | |
int b = i / 3; | |
setFunctionModule(a, b, bit); | |
setFunctionModule(b, a, bit); | |
} | |
} | |
void QrCode::drawFinderPattern(int x, int y) { | |
for (int dy = -4; dy <= 4; dy++) { | |
for (int dx = -4; dx <= 4; dx++) { | |
int dist = std::max(std::abs(dx), std::abs(dy)); // Chebyshev/infinity norm | |
int xx = x + dx, yy = y + dy; | |
if (0 <= xx && xx < size && 0 <= yy && yy < size) | |
setFunctionModule(xx, yy, dist != 2 && dist != 4); | |
} | |
} | |
} | |
void QrCode::drawAlignmentPattern(int x, int y) { | |
for (int dy = -2; dy <= 2; dy++) { | |
for (int dx = -2; dx <= 2; dx++) | |
setFunctionModule(x + dx, y + dy, std::max(std::abs(dx), std::abs(dy)) != 1); | |
} | |
} | |
void QrCode::setFunctionModule(int x, int y, bool isBlack) { | |
size_t ux = static_cast<size_t>(x); | |
size_t uy = static_cast<size_t>(y); | |
modules .at(uy).at(ux) = isBlack; | |
isFunction.at(uy).at(ux) = true; | |
} | |
bool QrCode::module(int x, int y) const { | |
return modules.at(static_cast<size_t>(y)).at(static_cast<size_t>(x)); | |
} | |
vector<uint8_t> QrCode::addEccAndInterleave(const vector<uint8_t> &data) const { | |
if (data.size() != static_cast<unsigned int>(getNumDataCodewords(version, errorCorrectionLevel))) | |
throw std::invalid_argument("Invalid argument"); | |
// Calculate parameter numbers | |
int numBlocks = NUM_ERROR_CORRECTION_BLOCKS[static_cast<int>(errorCorrectionLevel)][version]; | |
int blockEccLen = ECC_CODEWORDS_PER_BLOCK [static_cast<int>(errorCorrectionLevel)][version]; | |
int rawCodewords = getNumRawDataModules(version) / 8; | |
int numShortBlocks = numBlocks - rawCodewords % numBlocks; | |
int shortBlockLen = rawCodewords / numBlocks; | |
// Split data into blocks and append ECC to each block | |
vector<vector<uint8_t> > blocks; | |
const vector<uint8_t> rsDiv = reedSolomonComputeDivisor(blockEccLen); | |
for (int i = 0, k = 0; i < numBlocks; i++) { | |
vector<uint8_t> dat(data.cbegin() + k, data.cbegin() + (k + shortBlockLen - blockEccLen + (i < numShortBlocks ? 0 : 1))); | |
k += static_cast<int>(dat.size()); | |
const vector<uint8_t> ecc = reedSolomonComputeRemainder(dat, rsDiv); | |
if (i < numShortBlocks) | |
dat.push_back(0); | |
dat.insert(dat.end(), ecc.cbegin(), ecc.cend()); | |
blocks.push_back(std::move(dat)); | |
} | |
// Interleave (not concatenate) the bytes from every block into a single sequence | |
vector<uint8_t> result; | |
for (size_t i = 0; i < blocks.at(0).size(); i++) { | |
for (size_t j = 0; j < blocks.size(); j++) { | |
// Skip the padding byte in short blocks | |
if (i != static_cast<unsigned int>(shortBlockLen - blockEccLen) || j >= static_cast<unsigned int>(numShortBlocks)) | |
result.push_back(blocks.at(j).at(i)); | |
} | |
} | |
if (result.size() != static_cast<unsigned int>(rawCodewords)) | |
throw std::logic_error("Assertion error"); | |
return result; | |
} | |
void QrCode::drawCodewords(const vector<uint8_t> &data) { | |
if (data.size() != static_cast<unsigned int>(getNumRawDataModules(version) / 8)) | |
throw std::invalid_argument("Invalid argument"); | |
size_t i = 0; // Bit index into the data | |
// Do the funny zigzag scan | |
for (int right = size - 1; right >= 1; right -= 2) { // Index of right column in each column pair | |
if (right == 6) | |
right = 5; | |
for (int vert = 0; vert < size; vert++) { // Vertical counter | |
for (int j = 0; j < 2; j++) { | |
size_t x = static_cast<size_t>(right - j); // Actual x coordinate | |
bool upward = ((right + 1) & 2) == 0; | |
size_t y = static_cast<size_t>(upward ? size - 1 - vert : vert); // Actual y coordinate | |
if (!isFunction.at(y).at(x) && i < data.size() * 8) { | |
modules.at(y).at(x) = getBit(data.at(i >> 3), 7 - static_cast<int>(i & 7)); | |
i++; | |
} | |
// If this QR Code has any remainder bits (0 to 7), they were assigned as | |
// 0/false/white by the constructor and are left unchanged by this method | |
} | |
} | |
} | |
if (i != data.size() * 8) | |
throw std::logic_error("Assertion error"); | |
} | |
void QrCode::applyMask(int msk) { | |
if (msk < 0 || msk > 7) | |
throw std::domain_error("Mask value out of range"); | |
size_t sz = static_cast<size_t>(size); | |
for (size_t y = 0; y < sz; y++) { | |
for (size_t x = 0; x < sz; x++) { | |
bool invert; | |
switch (msk) { | |
case 0: invert = (x + y) % 2 == 0; break; | |
case 1: invert = y % 2 == 0; break; | |
case 2: invert = x % 3 == 0; break; | |
case 3: invert = (x + y) % 3 == 0; break; | |
case 4: invert = (x / 3 + y / 2) % 2 == 0; break; | |
case 5: invert = x * y % 2 + x * y % 3 == 0; break; | |
case 6: invert = (x * y % 2 + x * y % 3) % 2 == 0; break; | |
case 7: invert = ((x + y) % 2 + x * y % 3) % 2 == 0; break; | |
default: throw std::logic_error("Assertion error"); | |
} | |
modules.at(y).at(x) = modules.at(y).at(x) ^ (invert & !isFunction.at(y).at(x)); | |
} | |
} | |
} | |
long QrCode::getPenaltyScore() const { | |
long result = 0; | |
// Adjacent modules in row having same color, and finder-like patterns | |
for (int y = 0; y < size; y++) { | |
bool runColor = false; | |
int runX = 0; | |
std::array<int,7> runHistory = {}; | |
for (int x = 0; x < size; x++) { | |
if (module(x, y) == runColor) { | |
runX++; | |
if (runX == 5) | |
result += PENALTY_N1; | |
else if (runX > 5) | |
result++; | |
} else { | |
finderPenaltyAddHistory(runX, runHistory); | |
if (!runColor) | |
result += finderPenaltyCountPatterns(runHistory) * PENALTY_N3; | |
runColor = module(x, y); | |
runX = 1; | |
} | |
} | |
result += finderPenaltyTerminateAndCount(runColor, runX, runHistory) * PENALTY_N3; | |
} | |
// Adjacent modules in column having same color, and finder-like patterns | |
for (int x = 0; x < size; x++) { | |
bool runColor = false; | |
int runY = 0; | |
std::array<int,7> runHistory = {}; | |
for (int y = 0; y < size; y++) { | |
if (module(x, y) == runColor) { | |
runY++; | |
if (runY == 5) | |
result += PENALTY_N1; | |
else if (runY > 5) | |
result++; | |
} else { | |
finderPenaltyAddHistory(runY, runHistory); | |
if (!runColor) | |
result += finderPenaltyCountPatterns(runHistory) * PENALTY_N3; | |
runColor = module(x, y); | |
runY = 1; | |
} | |
} | |
result += finderPenaltyTerminateAndCount(runColor, runY, runHistory) * PENALTY_N3; | |
} | |
// 2*2 blocks of modules having same color | |
for (int y = 0; y < size - 1; y++) { | |
for (int x = 0; x < size - 1; x++) { | |
bool color = module(x, y); | |
if ( color == module(x + 1, y) && | |
color == module(x, y + 1) && | |
color == module(x + 1, y + 1)) | |
result += PENALTY_N2; | |
} | |
} | |
// Balance of black and white modules | |
int black = 0; | |
for (const vector<bool> &row : modules) { | |
for (bool color : row) { | |
if (color) | |
black++; | |
} | |
} | |
int total = size * size; // Note that size is odd, so black/total != 1/2 | |
// Compute the smallest integer k >= 0 such that (45-5k)% <= black/total <= (55+5k)% | |
int k = static_cast<int>((std::abs(black * 20L - total * 10L) + total - 1) / total) - 1; | |
result += k * PENALTY_N4; | |
return result; | |
} | |
vector<int> QrCode::getAlignmentPatternPositions() const { | |
if (version == 1) | |
return vector<int>(); | |
else { | |
int numAlign = version / 7 + 2; | |
int step = (version == 32) ? 26 : | |
(version*4 + numAlign*2 + 1) / (numAlign*2 - 2) * 2; | |
vector<int> result; | |
for (int i = 0, pos = size - 7; i < numAlign - 1; i++, pos -= step) | |
result.insert(result.begin(), pos); | |
result.insert(result.begin(), 6); | |
return result; | |
} | |
} | |
int QrCode::getNumRawDataModules(int ver) { | |
if (ver < MIN_VERSION || ver > MAX_VERSION) | |
throw std::domain_error("Version number out of range"); | |
int result = (16 * ver + 128) * ver + 64; | |
if (ver >= 2) { | |
int numAlign = ver / 7 + 2; | |
result -= (25 * numAlign - 10) * numAlign - 55; | |
if (ver >= 7) | |
result -= 36; | |
} | |
if (!(208 <= result && result <= 29648)) | |
throw std::logic_error("Assertion error"); | |
return result; | |
} | |
int QrCode::getNumDataCodewords(int ver, Ecc ecl) { | |
return getNumRawDataModules(ver) / 8 | |
- ECC_CODEWORDS_PER_BLOCK [static_cast<int>(ecl)][ver] | |
* NUM_ERROR_CORRECTION_BLOCKS[static_cast<int>(ecl)][ver]; | |
} | |
vector<uint8_t> QrCode::reedSolomonComputeDivisor(int degree) { | |
if (degree < 1 || degree > 255) | |
throw std::domain_error("Degree out of range"); | |
// Polynomial coefficients are stored from highest to lowest power, excluding the leading term which is always 1. | |
// For example the polynomial x^3 + 255x^2 + 8x + 93 is stored as the uint8 array {255, 8, 93}. | |
vector<uint8_t> result(static_cast<size_t>(degree)); | |
result.at(result.size() - 1) = 1; // Start off with the monomial x^0 | |
// Compute the product polynomial (x - r^0) * (x - r^1) * (x - r^2) * ... * (x - r^{degree-1}), | |
// and drop the highest monomial term which is always 1x^degree. | |
// Note that r = 0x02, which is a generator element of this field GF(2^8/0x11D). | |
uint8_t root = 1; | |
for (int i = 0; i < degree; i++) { | |
// Multiply the current product by (x - r^i) | |
for (size_t j = 0; j < result.size(); j++) { | |
result.at(j) = reedSolomonMultiply(result.at(j), root); | |
if (j + 1 < result.size()) | |
result.at(j) ^= result.at(j + 1); | |
} | |
root = reedSolomonMultiply(root, 0x02); | |
} | |
return result; | |
} | |
vector<uint8_t> QrCode::reedSolomonComputeRemainder(const vector<uint8_t> &data, const vector<uint8_t> &divisor) { | |
vector<uint8_t> result(divisor.size()); | |
for (uint8_t b : data) { // Polynomial division | |
uint8_t factor = b ^ result.at(0); | |
result.erase(result.begin()); | |
result.push_back(0); | |
for (size_t i = 0; i < result.size(); i++) | |
result.at(i) ^= reedSolomonMultiply(divisor.at(i), factor); | |
} | |
return result; | |
} | |
uint8_t QrCode::reedSolomonMultiply(uint8_t x, uint8_t y) { | |
// Russian peasant multiplication | |
int z = 0; | |
for (int i = 7; i >= 0; i--) { | |
z = (z << 1) ^ ((z >> 7) * 0x11D); | |
z ^= ((y >> i) & 1) * x; | |
} | |
if (z >> 8 != 0) | |
throw std::logic_error("Assertion error"); | |
return static_cast<uint8_t>(z); | |
} | |
int QrCode::finderPenaltyCountPatterns(const std::array<int,7> &runHistory) const { | |
int n = runHistory.at(1); | |
if (n > size * 3) | |
throw std::logic_error("Assertion error"); | |
bool core = n > 0 && runHistory.at(2) == n && runHistory.at(3) == n * 3 && runHistory.at(4) == n && runHistory.at(5) == n; | |
return (core && runHistory.at(0) >= n * 4 && runHistory.at(6) >= n ? 1 : 0) | |
+ (core && runHistory.at(6) >= n * 4 && runHistory.at(0) >= n ? 1 : 0); | |
} | |
int QrCode::finderPenaltyTerminateAndCount(bool currentRunColor, int currentRunLength, std::array<int,7> &runHistory) const { | |
if (currentRunColor) { // Terminate black run | |
finderPenaltyAddHistory(currentRunLength, runHistory); | |
currentRunLength = 0; | |
} | |
currentRunLength += size; // Add white border to final run | |
finderPenaltyAddHistory(currentRunLength, runHistory); | |
return finderPenaltyCountPatterns(runHistory); | |
} | |
void QrCode::finderPenaltyAddHistory(int currentRunLength, std::array<int,7> &runHistory) const { | |
if (runHistory.at(0) == 0) | |
currentRunLength += size; // Add white border to initial run | |
std::copy_backward(runHistory.cbegin(), runHistory.cend() - 1, runHistory.end()); | |
runHistory.at(0) = currentRunLength; | |
} | |
bool QrCode::getBit(long x, int i) { | |
return ((x >> i) & 1) != 0; | |
} | |
/*---- Tables of constants ----*/ | |
const int QrCode::PENALTY_N1 = 3; | |
const int QrCode::PENALTY_N2 = 3; | |
const int QrCode::PENALTY_N3 = 40; | |
const int QrCode::PENALTY_N4 = 10; | |
const int8_t QrCode::ECC_CODEWORDS_PER_BLOCK[4][41] = { | |
// Version: (note that index 0 is for padding, and is set to an illegal value) | |
//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 | |
{-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 | |
{-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 | |
{-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 | |
{-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 | |
}; | |
const int8_t QrCode::NUM_ERROR_CORRECTION_BLOCKS[4][41] = { | |
// Version: (note that index 0 is for padding, and is set to an illegal value) | |
//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 | |
{-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 | |
{-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 | |
{-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 | |
{-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 | |
}; | |
data_too_long::data_too_long(const std::string &msg) : | |
std::length_error(msg) {} | |
BitBuffer::BitBuffer() | |
: std::vector<bool>() {} | |
void BitBuffer::appendBits(std::uint32_t val, int len) { | |
if (len < 0 || len > 31 || val >> len != 0) | |
throw std::domain_error("Value out of range"); | |
for (int i = len - 1; i >= 0; i--) // Append bit by bit | |
this->push_back(((val >> i) & 1) != 0); | |
} | |
} |