/// <summary>
/// Reads the given number of bits into the value and returns whether the stream could be read from or not.
/// </summary>
/// <param name="value">The value of the read bits.</param>
/// <param name="bits">The number of bits to read.</param>
/// <returns>Whether the stream could be read from or not.</returns>
public bool ReadBits(out byte value, BitNum bits)
{
if (BitPosition == BitNum.MaxValue && bits == BitNum.MaxValue)
{
var readByte = stream.ReadByte();
value = (byte)(readByte < 0 ? 0 : readByte);
currentByte = value;
return(!(readByte < 0));
}
value = 0;
for (byte i = 1; i <= bits; ++i)
{
if (BitPosition == BitNum.MaxValue)
{
var readByte = stream.ReadByte();
if (readByte < 0)
{
return(i > 1);
}
currentByte = (byte)readByte;
}
advanceBitPosition();
value |= getAdjustedValue(currentByte, BitPosition, (BitNum)i);
}
return(true);
}
private BitNum(byte value, bool overide)
{
if (!overide)
{
this = new BitNum(value);
}
else
{
this.value = value;
}
}
private static byte getAdjustedValue(byte value, BitNum currentPosition, BitNum targetPosition)
{
value &= currentPosition.GetBitPos();
if (currentPosition > targetPosition)
{
return((byte)(value >> (currentPosition - targetPosition)));
}
else if (currentPosition < targetPosition)
{
return((byte)(value << (targetPosition - currentPosition)));
}
else
{
return(value);
}
}
/// <summary>
/// Writes the given number of bits from the value.
/// </summary>
/// <param name="value">The value to write from.</param>
/// <param name="bits">The number of bits to write.</param>
public void WriteBits(byte value, BitNum bits)
{
if (BitPosition == BitNum.MaxValue && bits == BitNum.MaxValue)
{
stream.WriteByte(value);
currentByte = 0;
return;
}
for (byte i = 1; i <= bits; ++i)
{
advanceBitPosition();
currentByte |= getAdjustedValue(value, (BitNum)i, BitPosition);
if (BitPosition == BitNum.MaxValue)
{
stream.WriteByte(currentByte);
currentByte = 0;
}
}
}
