Method Encode

czxing/src/main/cpp/zxing/src/aztec/AZEncoder.cpp:165–302

* Encodes the given binary content as an Aztec symbol * * @param data input data string * @param minECCPercent minimal percentage of error check words (According to ISO/IEC 24778:2008, * a minimum of 23% + 3 words is recommended) * @param userSpecifiedLayers if non-zero, a user-specified value for the number of layers * @return Aztec symbol matrix with metadata */

* @return Aztec symbol matrix with metadata
*/
EncodeResult
Encoder::Encode(const std::string& data, int minECCPercent, int userSpecifiedLayers)
{
	// High-level encode
	BitArray bits = HighLevelEncoder::Encode(data);

	// stuff bits and choose symbol size
	int eccBits = bits.size() * minECCPercent / 100 + 11;
	int totalSizeBits = bits.size() + eccBits;
	bool compact;
	int layers;
	int totalBitsInLayer;
	int wordSize;
	BitArray stuffedBits;
	if (userSpecifiedLayers != DEFAULT_AZTEC_LAYERS) {
		compact = userSpecifiedLayers < 0;
		layers = std::abs(userSpecifiedLayers);
		if (layers > (compact ? MAX_NB_BITS_COMPACT : MAX_NB_BITS)) {
			throw std::invalid_argument("Illegal value for layers: " + std::to_string(userSpecifiedLayers));
		}
		totalBitsInLayer = TotalBitsInLayer(layers, compact);
		wordSize = WORD_SIZE[layers];
		int usableBitsInLayers = totalBitsInLayer - (totalBitsInLayer % wordSize);
		StuffBits(bits, wordSize, stuffedBits);
		if (stuffedBits.size() + eccBits > usableBitsInLayers) {
			throw std::invalid_argument("Data to large for user specified layer");
		}
		if (compact && stuffedBits.size() > wordSize * 64) {
			// Compact format only allows 64 data words, though C4 can hold more words than that
			throw std::invalid_argument("Data to large for user specified layer");
		}
	}
	else {
		wordSize = 0;
		// We look at the possible table sizes in the order Compact1, Compact2, Compact3,
		// Compact4, Normal4,...  Normal(i) for i < 4 isn't typically used since Compact(i+1)
		// is the same size, but has more data.
		for (int i = 0; ; i++) {
			if (i > MAX_NB_BITS) {
				throw std::invalid_argument("Data too large for an Aztec code");
			}
			compact = i <= 3;
			layers = compact ? i + 1 : i;
			totalBitsInLayer = TotalBitsInLayer(layers, compact);
			if (totalSizeBits > totalBitsInLayer) {
				continue;
			}
			// [Re]stuff the bits if this is the first opportunity, or if the
			// wordSize has changed
			if (wordSize != WORD_SIZE[layers]) {
				wordSize = WORD_SIZE[layers];
				StuffBits(bits, wordSize, stuffedBits);
			}
			int usableBitsInLayers = totalBitsInLayer - (totalBitsInLayer % wordSize);
			if (compact && stuffedBits.size() > wordSize * 64) {
				// Compact format only allows 64 data words, though C4 can hold more words than that
				continue;
			}