/// <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.
System.Collections.ArrayList blocks = System.Collections.ArrayList.Synchronized(new System.Collections.ArrayList(numRSBlocks));
for (int i = 0; i < numRSBlocks; ++i)
{
int[] numDataBytesInBlock = new int[1];
int[] numEcBytesInBlock = new int[1];
getNumDataBytesAndNumECBytesForBlockID(numTotalBytes, numDataBytes, numRSBlocks, i, numDataBytesInBlock, numEcBytesInBlock);
ByteArray dataBytes = new ByteArray();
dataBytes.set_Renamed(bits.Array, dataBytesOffset, numDataBytesInBlock[0]);
ByteArray ecBytes = generateECBytes(dataBytes, numEcBytesInBlock[0]);
blocks.Add(new BlockPair(dataBytes, ecBytes));
maxNumDataBytes = System.Math.Max(maxNumDataBytes, dataBytes.size());
maxNumEcBytes = System.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.");
}
}
internal BlockPair(ByteArray data, ByteArray errorCorrection)
{
dataBytes = data;
errorCorrectionBytes = errorCorrection;
}
internal static ByteArray generateECBytes(ByteArray dataBytes, int numEcBytesInBlock)
{
int numDataBytes = dataBytes.size();
int[] toEncode = new int[numDataBytes + numEcBytesInBlock];
for (int i = 0; i < numDataBytes; i++)
{
toEncode[i] = dataBytes.at(i);
}
new ReedSolomonEncoder(GF256.QR_CODE_FIELD).encode(toEncode, numEcBytesInBlock);
ByteArray ecBytes = new ByteArray(numEcBytesInBlock);
for (int i = 0; i < numEcBytesInBlock; i++)
{
ecBytes.set_Renamed(i, toEncode[numDataBytes + i]);
}
return ecBytes;
}