BaseNcoding.BaseN.AddBits64 C# (CSharp) Метод

        private static void AddBits64(byte[] data, ulong value, int bitPos, int bitsCount)
        {
            unchecked
            {
                int currentBytePos = bitPos / 8;
                int currentBitInBytePos = bitPos % 8;

                int xLength = Math.Min(bitsCount, 8 - currentBitInBytePos);
                if (xLength != 0)
                {
                    byte x1 = (byte)(value << 64 - bitsCount >> 56 + currentBitInBytePos);
                    data[currentBytePos] |= x1;

                    currentBytePos += (currentBitInBytePos + xLength) / 8;
                    currentBitInBytePos = (currentBitInBytePos + xLength) % 8;

                    int x2Length = bitsCount - xLength;
                    if (x2Length > 8)
                        x2Length = 8;

                    while (x2Length > 0)
                    {
                        xLength += x2Length;
                        byte x2 = (byte)(value >> bitsCount - xLength << 8 - x2Length);
                        data[currentBytePos] |= x2;

                        currentBytePos += (currentBitInBytePos + x2Length) / 8;
                        currentBitInBytePos = (currentBitInBytePos + x2Length) % 8;

                        x2Length = bitsCount - xLength;
                        if (x2Length > 8)
                            x2Length = 8;
                    }
                }
            }
        }