// more complex 1 or 2 bit header (possible values are 1b, 01b and 00b) smallest header used for most common
// length range where bits <= 16
static void Example2_2Divisions()
{
MemoryStream packedData = new MemoryStream();
BitStreamWriter bitWriter = new BitStreamWriter();
const int MAX_BITS = 32;
const int MED_BITS = 16;
const int MIN_BITS = 13;
// let's pack them into a stream!
foreach (uint v in values)
{
uint size = CountBits(v);
// if there are 16 bits or fewer, write only 16+1 bits
if (size <= MED_BITS)
{
if (size <= MIN_BITS)
{
bitWriter.WriteBits(1, 1, packedData);
bitWriter.WriteBits(v, MIN_BITS, packedData);
}
else
{
bitWriter.WriteBits(2, 2, packedData);
bitWriter.WriteBits(v, MED_BITS, packedData);
}
}
else
{
bitWriter.WriteBits(0, 2, packedData);
bitWriter.WriteBits(v, MAX_BITS, packedData);
}
}
bitWriter.WriteFlush(packedData);
Console.WriteLine("Original size = {0}, packed size = {1}", values.Length * sizeof(uint), packedData.Length);
// now read the data back
//
// rewind our stream so we can read it back
packedData.Seek(0, SeekOrigin.Begin);
BitStreamReader bitReader = new BitStreamReader();
uint[] output = new uint[values.Length];
for (int i = 0; i < output.Length; ++i)
{
uint header = bitReader.ReadBits(1, packedData);
switch (header)
{
case 1:
output[i] = bitReader.ReadBits(MIN_BITS, packedData);
break;
// if the bit is 0, there is a second bit with length subsections
case 0:
uint secondBit = bitReader.ReadBits(1, packedData);
if (secondBit == 0)
{
output[i] = bitReader.ReadBits(MAX_BITS, packedData);
}
else
{
output[i] = bitReader.ReadBits(MED_BITS, packedData);
}
break;
}
if (output[i] == values[i])
{
Console.WriteLine("Position {0} matches!", i);
}
}
}
