Function Encode

czxing/src/main/cpp/zxing/src/qrcode/QREncoder.cpp:483–569

}

EncodeResult Encode(const std::wstring& content, ErrorCorrectionLevel ecLevel, CharacterSet charset, int versionNumber,
					bool useGs1Format, int maskPattern)
{
	bool charsetWasUnknown = charset == CharacterSet::Unknown;
	if (charsetWasUnknown) {
		charset = DEFAULT_BYTE_MODE_ENCODING;
	}

	// Pick an encoding mode appropriate for the content. Note that this will not attempt to use
	// multiple modes / segments even if that were more efficient. Twould be nice.
	CodecMode mode = ChooseMode(content, charset);

	// This will store the header information, like mode and
	// length, as well as "header" segments like an ECI segment.
	BitArray headerBits;

	// Append ECI segment if applicable
	if (mode == CodecMode::BYTE && !charsetWasUnknown) {
		AppendECI(charset, headerBits);
	}

	// Append the FNC1 mode header for GS1 formatted data if applicable
	if (useGs1Format) {
		// GS1 formatted codes are prefixed with a FNC1 in first position mode header
		AppendModeInfo(CodecMode::FNC1_FIRST_POSITION, headerBits);
	}

	// (With ECI in place,) Write the mode marker
	AppendModeInfo(mode, headerBits);

	// Collect data within the main segment, separately, to count its size if needed. Don't add it to
	// main payload yet.
	BitArray dataBits;
	AppendBytes(content, mode, charset, dataBits);

	const Version* version;
	if (versionNumber > 0) {
		version = Version::FromNumber(versionNumber);
		if (version != nullptr) {
			int bitsNeeded = CalculateBitsNeeded(mode, headerBits, dataBits, *version);
			if (!WillFit(bitsNeeded, *version, ecLevel)) {
				throw std::invalid_argument("Data too big for requested version");
			}
		}
		else {
			version = &RecommendVersion(ecLevel, mode, headerBits, dataBits);
		}
	}
	else {
		version = &RecommendVersion(ecLevel, mode, headerBits, dataBits);
	}

	BitArray headerAndDataBits;
	headerAndDataBits.appendBitArray(headerBits);
	// Find "length" of main segment and write it
	int numLetters = mode == CodecMode::BYTE ? dataBits.sizeInBytes() : Size(content);
	AppendLengthInfo(numLetters, *version, mode, headerAndDataBits);
	// Put data together into the overall payload