/// <summary> Initialize "qrCode" according to "numInputBytes", "ecLevel", and "mode". On success, /// modify "qrCode". /// </summary> private static void initQRCode(int numInputBytes, ErrorCorrectionLevel ecLevel, Mode mode, QRCode qrCode) { qrCode.ECLevel = ecLevel; qrCode.Mode = mode; // In the following comments, we use numbers of Version 7-H. for (int versionNum = 1; versionNum <= 40; versionNum++) { Version version = Version.getVersionForNumber(versionNum); // numBytes = 196 int numBytes = version.TotalCodewords; // getNumECBytes = 130 Version.ECBlocks ecBlocks = version.getECBlocksForLevel(ecLevel); int numEcBytes = ecBlocks.TotalECCodewords; // getNumRSBlocks = 5 int numRSBlocks = ecBlocks.NumBlocks; // getNumDataBytes = 196 - 130 = 66 int numDataBytes = numBytes - numEcBytes; // We want to choose the smallest version which can contain data of "numInputBytes" + some // extra bits for the header (mode info and length info). The header can be three bytes // (precisely 4 + 16 bits) at most. Hence we do +3 here. if (numDataBytes >= numInputBytes + 3) { // Yay, we found the proper rs block info! qrCode.Version = versionNum; qrCode.NumTotalBytes = numBytes; qrCode.NumDataBytes = numDataBytes; qrCode.NumRSBlocks = numRSBlocks; // getNumECBytes = 196 - 66 = 130 qrCode.NumECBytes = numEcBytes; // matrix width = 21 + 6 * 4 = 45 qrCode.MatrixWidth = version.DimensionForVersion; return ; } } throw new WriterException("Cannot find proper rs block info (input data too big?)"); }
/// <summary> Append length info. On success, store the result in "bits".</summary> internal static void appendLengthInfo(int numLetters, int version, Mode mode, BitVector bits) { int numBits = mode.getCharacterCountBits(Version.getVersionForNumber(version)); if (numLetters > ((1 << numBits) - 1)) { throw new WriterException(numLetters + "is bigger than" + ((1 << numBits) - 1)); } bits.appendBits(numLetters, numBits); }
/// <summary> Append mode info. On success, store the result in "bits".</summary> internal static void appendModeInfo(Mode mode, BitVector bits) { bits.appendBits(mode.Bits, 4); }
/// <summary> Append "bytes" in "mode" mode (encoding) into "bits". On success, store the result in "bits".</summary> internal static void appendBytes(System.String content, Mode mode, BitVector bits, System.String encoding) { if (mode.Equals(Mode.NUMERIC)) { appendNumericBytes(content, bits); } else if (mode.Equals(Mode.ALPHANUMERIC)) { appendAlphanumericBytes(content, bits); } else if (mode.Equals(Mode.BYTE)) { append8BitBytes(content, bits, encoding); } else if (mode.Equals(Mode.KANJI)) { appendKanjiBytes(content, bits); } else { throw new WriterException("Invalid mode: " + mode); } }