/// <summary> Interleave "bits" with corresponding error correction bytes. On success, store the result in
/// "result". The interleave rule is complicated. See 8.6 of JISX0510:2004 (p.37) for details.
/// </summary>
internal static void interleaveWithECBytes(BitVector bits, int numTotalBytes, int numDataBytes, int numRSBlocks,
BitVector result)
{
// "bits" must have "getNumDataBytes" bytes of data.
if (bits.sizeInBytes() != numDataBytes)
{
throw new WriterException("Number of bits and data bytes does not match");
}
// Step 1. Divide data bytes into blocks and generate error correction bytes for them. We'll
// store the divided data bytes blocks and error correction bytes blocks into "blocks".
int dataBytesOffset = 0;
int maxNumDataBytes = 0;
int maxNumEcBytes = 0;
// Since, we know the number of reedsolmon blocks, we can initialize the vector with the number.
var blocks = new List<BlockPair>(numRSBlocks);
for (int i = 0; i < numRSBlocks; ++i)
{
var numDataBytesInBlock = new int[1];
var numEcBytesInBlock = new int[1];
getNumDataBytesAndNumECBytesForBlockID(numTotalBytes, numDataBytes, numRSBlocks, i, numDataBytesInBlock,
numEcBytesInBlock);
var dataBytes = new ByteArray();
dataBytes.set_Renamed(bits.Array, dataBytesOffset, numDataBytesInBlock[0]);
ByteArray ecBytes = generateECBytes(dataBytes, numEcBytesInBlock[0]);
blocks.Add(new BlockPair(dataBytes, ecBytes));
maxNumDataBytes = Math.Max(maxNumDataBytes, dataBytes.size());
maxNumEcBytes = Math.Max(maxNumEcBytes, ecBytes.size());
dataBytesOffset += numDataBytesInBlock[0];
}
if (numDataBytes != dataBytesOffset)
{
throw new WriterException("Data bytes does not match offset");
}
// First, place data blocks.
for (int i = 0; i < maxNumDataBytes; ++i)
{
for (int j = 0; j < blocks.Count; ++j)
{
ByteArray dataBytes = ((BlockPair) blocks[j]).DataBytes;
if (i < dataBytes.size())
{
result.appendBits(dataBytes.at(i), 8);
}
}
}
// Then, place error correction blocks.
for (int i = 0; i < maxNumEcBytes; ++i)
{
for (int j = 0; j < blocks.Count; ++j)
{
ByteArray ecBytes = ((BlockPair) blocks[j]).ErrorCorrectionBytes;
if (i < ecBytes.size())
{
result.appendBits(ecBytes.at(i), 8);
}
}
}
if (numTotalBytes != result.sizeInBytes())
{
// Should be same.
throw new WriterException("Interleaving error: " + numTotalBytes + " and " + result.sizeInBytes() +
" differ.");
}
}
public static void encode(String content, ErrorCorrectionLevel ecLevel, Dictionary<EncodeHintType, Object> hints,
QRCode qrCode)
{
String encoding = hints == null ? null : (String) hints[EncodeHintType.CHARACTER_SET];
if (encoding == null)
{
encoding = DEFAULT_BYTE_MODE_ENCODING;
}
// Step 1: Choose the mode (encoding).
Mode mode = chooseMode(content, encoding);
// Step 2: Append "bytes" into "dataBits" in appropriate encoding.
var dataBits = new BitVector();
appendBytes(content, mode, dataBits, encoding);
// Step 3: Initialize QR code that can contain "dataBits".
int numInputBytes = dataBits.sizeInBytes();
initQRCode(numInputBytes, ecLevel, mode, qrCode);
// Step 4: Build another bit vector that contains header and data.
var headerAndDataBits = new BitVector();
// Step 4.5: Append ECI message if applicable
if (mode == Mode.BYTE && !DEFAULT_BYTE_MODE_ENCODING.Equals(encoding))
{
CharacterSetECI eci = CharacterSetECI.getCharacterSetECIByName(encoding);
if (eci != null)
{
appendECI(eci, headerAndDataBits);
}
}
appendModeInfo(mode, headerAndDataBits);
int numLetters = mode.Equals(Mode.BYTE) ? dataBits.sizeInBytes() : content.Length;
appendLengthInfo(numLetters, qrCode.Version, mode, headerAndDataBits);
headerAndDataBits.appendBitVector(dataBits);
// Step 5: Terminate the bits properly.
terminateBits(qrCode.NumDataBytes, headerAndDataBits);
// Step 6: Interleave data bits with error correction code.
var finalBits = new BitVector();
interleaveWithECBytes(headerAndDataBits, qrCode.NumTotalBytes, qrCode.NumDataBytes, qrCode.NumRSBlocks,
finalBits);
// Step 7: Choose the mask pattern and set to "qrCode".
var matrix = new ByteMatrix(qrCode.MatrixWidth, qrCode.MatrixWidth);
qrCode.MaskPattern = chooseMaskPattern(finalBits, qrCode.ECLevel, qrCode.Version, matrix);
// Step 8. Build the matrix and set it to "qrCode".
MatrixUtil.buildMatrix(finalBits, qrCode.ECLevel, qrCode.Version, qrCode.MaskPattern, matrix);
qrCode.Matrix = matrix;
// Step 9. Make sure we have a valid QR Code.
if (!qrCode.Valid)
{
throw new WriterException("Invalid QR code: " + qrCode);
}
}
/// <summary> Terminate bits as described in 8.4.8 and 8.4.9 of JISX0510:2004 (p.24).</summary>
internal static void terminateBits(int numDataBytes, BitVector bits)
{
int capacity = numDataBytes << 3;
if (bits.size() > capacity)
{
throw new WriterException("data bits cannot fit in the QR Code" + bits.size() + " > " + capacity);
}
// Append termination bits. See 8.4.8 of JISX0510:2004 (p.24) for details.
// TODO: srowen says we can remove this for loop, since the 4 terminator bits are optional if
// the last byte has less than 4 bits left. So it amounts to padding the last byte with zeroes
// either way.
for (int i = 0; i < 4 && bits.size() < capacity; ++i)
{
bits.appendBit(0);
}
int numBitsInLastByte = bits.size()%8;
// If the last byte isn't 8-bit aligned, we'll add padding bits.
if (numBitsInLastByte > 0)
{
int numPaddingBits = 8 - numBitsInLastByte;
for (int i = 0; i < numPaddingBits; ++i)
{
bits.appendBit(0);
}
}
// Should be 8-bit aligned here.
if (bits.size()%8 != 0)
{
throw new WriterException("Number of bits is not a multiple of 8");
}
// If we have more space, we'll fill the space with padding patterns defined in 8.4.9 (p.24).
int numPaddingBytes = numDataBytes - bits.sizeInBytes();
for (int i = 0; i < numPaddingBytes; ++i)
{
if (i%2 == 0)
{
bits.appendBits(0xec, 8);
}
else
{
bits.appendBits(0x11, 8);
}
}
if (bits.size() != capacity)
{
throw new WriterException("Bits size does not equal capacity");
}
}
