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Added comments and renamed variables in QrCode.appendErrorCorrection() in all language versions.

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Nayuki Minase
2016-04-21 01:57:58 +00:00
parent 1fb0283189
commit 4fcf02d1f9
4 changed files with 45 additions and 25 deletions
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cpp/QrCode.cpp
+11 -6
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@@ -301,19 +301,22 @@ void qrcodegen::QrCode::setFunctionModule(int x, int y, bool isBlack) {
std::vector<uint8_t> qrcodegen::QrCode::appendErrorCorrection(const std::vector<uint8_t> &data) const {
if (data.size() != static_cast<unsigned int>(getNumDataCodewords(version, errorCorrectionLevel)))
throw "Invalid argument";
// Calculate parameter numbers
int numBlocks = NUM_ERROR_CORRECTION_BLOCKS[errorCorrectionLevel.ordinal][version];
int numEcc = NUM_ERROR_CORRECTION_CODEWORDS[errorCorrectionLevel.ordinal][version];
if (numEcc % numBlocks != 0)
int totalEcc = NUM_ERROR_CORRECTION_CODEWORDS[errorCorrectionLevel.ordinal][version];
if (totalEcc % numBlocks != 0)
throw "Assertion error";
int eccLen = numEcc / numBlocks;
int blockEccLen = totalEcc / numBlocks;
int numShortBlocks = numBlocks - getNumRawDataModules(version) / 8 % numBlocks;
int shortBlockLen = getNumRawDataModules(version) / 8 / numBlocks;
// Split data into blocks and append ECC to each block
std::vector<std::vector<uint8_t>> blocks;
const ReedSolomonGenerator rs(eccLen);
const ReedSolomonGenerator rs(blockEccLen);
for (int i = 0, k = 0; i < numBlocks; i++) {
std::vector<uint8_t> dat;
dat.insert(dat.begin(), data.begin() + k, data.begin() + (k + shortBlockLen - eccLen + (i < numShortBlocks ? 0 : 1)));
dat.insert(dat.begin(), data.begin() + k, data.begin() + (k + shortBlockLen - blockEccLen + (i < numShortBlocks ? 0 : 1)));
k += dat.size();
const std::vector<uint8_t> ecc(rs.getRemainder(dat));
if (i < numShortBlocks)
@@ -322,10 +325,12 @@ std::vector<uint8_t> qrcodegen::QrCode::appendErrorCorrection(const std::vector<
blocks.push_back(dat);
}
// Interleave (not concatenate) the bytes from every block into a single sequence
std::vector<uint8_t> result;
for (int i = 0; static_cast<unsigned int>(i) < blocks.at(0).size(); i++) {
for (int j = 0; static_cast<unsigned int>(j) < blocks.size(); j++) {
if (i != shortBlockLen - eccLen || j >= numShortBlocks)
// Skip the padding byte in short blocks
if (i != shortBlockLen - blockEccLen || j >= numShortBlocks)
result.push_back(blocks.at(j).at(i));
}
}