private void CopySourceBitsIntoLeftArray(byte[] sourceBits, int sourceArrayBitIndex,
int destinationBitIndex, int numBits)
{
var leftByteIndex = GetByteIndexFromBitIndex(destinationBitIndex);
var startingBitIndexOfFirstSourceByte = sourceArrayBitIndex % 8;
// Number of bit positions to shift the source bits to fill the unused positions in the last
// destination byte:
var numBitPositionsToShiftSourceBy = duoBitArrayUtilities
.GetNumBitsInUseInLastByte(destinationBitIndex) - startingBitIndexOfFirstSourceByte;
var firstByteIndexInSource = GetByteIndexFromBitIndex(sourceArrayBitIndex);
var lastSourceBitIndex = sourceArrayBitIndex + numBits - 1;
var lastByteIndexInSource = GetByteIndexFromBitIndex(lastSourceBitIndex);
var sourceBitsCopy = GetOnlyRelevantSourceBytes(sourceBits, sourceArrayBitIndex, numBits,
firstByteIndexInSource, lastByteIndexInSource, lastSourceBitIndex, numBitPositionsToShiftSourceBy);
for (var sourceByteIndex = 0;
sourceByteIndex < sourceBitsCopy.Length + (numBitPositionsToShiftSourceBy > 0 ? 1 : 0);
sourceByteIndex++, leftByteIndex++)
{
var sourceByteShiftedIntoPositionWithBorrowedBits = duoBitArrayUtilities
.ShiftBitsInOneByte(sourceBitsCopy, sourceByteIndex, numBitPositionsToShiftSourceBy);
bitArray[leftByteIndex] |= sourceByteShiftedIntoPositionWithBorrowedBits;
}
}
private byte[] GetMaskForConsecutiveLeftBits(int numBits)
{
var numBytes = duoBitArrayUtilities.GetMinNumBytesToStoreBits(numBits);
var generatedMask = new byte[numBytes];
generatedMask[numBytes - 1] =
duoBitArrayUtilities.GetByteMsbMask(duoBitArrayUtilities.GetNumBitsInUseInLastByte(numBits));
for (var i = 0; i < numBytes - 2; i++)
{
generatedMask[i] = 0xFF;
}
return(generatedMask);
}
