/// <summary> <p>When Data Matrix Codes use multiple data blocks, they actually interleave the bytes of each of them.
/// That is, the first byte of data block 1 to n is written, then the second bytes, and so on. This
/// method will separate the data into original blocks.</p>
///
/// </summary>
/// <param name="rawCodewords">bytes as read directly from the Data Matrix Code
/// </param>
/// <param name="version">version of the Data Matrix Code
/// </param>
/// <returns> {@link DataBlock}s containing original bytes, "de-interleaved" from representation in the
/// Data Matrix Code
/// </returns>
internal static DataBlock[] getDataBlocks(sbyte[] rawCodewords, Version version)
{
// Figure out the number and size of data blocks used by this version
Version.ECBlocks ecBlocks = version.getECBlocks();
// First count the total number of data blocks
int totalBlocks = 0;
Version.ECB[] ecBlockArray = ecBlocks.getECBlocks();
for (int i = 0; i < ecBlockArray.Length; i++)
{
totalBlocks += ecBlockArray[i].Count;
}
// Now establish DataBlocks of the appropriate size and number of data codewords
DataBlock[] result = new DataBlock[totalBlocks];
int numResultBlocks = 0;
for (int j = 0; j < ecBlockArray.Length; j++)
{
Version.ECB ecBlock = ecBlockArray[j];
for (int i = 0; i < ecBlock.Count; i++)
{
int numDataCodewords = ecBlock.DataCodewords;
int numBlockCodewords = ecBlocks.ECCodewords + numDataCodewords;
result[numResultBlocks++] = new DataBlock(numDataCodewords, new sbyte[numBlockCodewords]);
}
}
// All blocks have the same amount of data, except that the last n
// (where n may be 0) have 1 less byte. Figure out where these start.
// TODO(bbrown): There is only one case where there is a difference for Data Matrix for size 144
int longerBlocksTotalCodewords = result[0].codewords.Length;
//int shorterBlocksTotalCodewords = longerBlocksTotalCodewords - 1;
int longerBlocksNumDataCodewords = longerBlocksTotalCodewords - ecBlocks.ECCodewords;
int shorterBlocksNumDataCodewords = longerBlocksNumDataCodewords - 1;
// The last elements of result may be 1 element shorter for 144 matrix
// first fill out as many elements as all of them have minus 1
int rawCodewordsOffset = 0;
for (int i = 0; i < shorterBlocksNumDataCodewords; i++)
{
for (int j = 0; j < numResultBlocks; j++)
{
result[j].codewords[i] = rawCodewords[rawCodewordsOffset++];
}
}
// Fill out the last data block in the longer ones
bool specialVersion = version.VersionNumber == 24;
int numLongerBlocks = specialVersion?8:numResultBlocks;
for (int j = 0; j < numLongerBlocks; j++)
{
result[j].codewords[longerBlocksNumDataCodewords - 1] = rawCodewords[rawCodewordsOffset++];
}
// Now add in error correction blocks
int max = result[0].codewords.Length;
for (int i = longerBlocksNumDataCodewords; i < max; i++)
{
for (int j = 0; j < numResultBlocks; j++)
{
int iOffset = (specialVersion && j > 7)?i - 1:i;
result[j].codewords[iOffset] = rawCodewords[rawCodewordsOffset++];
}
}
if (rawCodewordsOffset != rawCodewords.Length)
{
throw new System.ArgumentException();
}
return result;
}
