public BitLattice Encode()
{
// --- Sign ---
BitLattice b = new BitLattice(size);
b.AddField(SignField, size - 1, 1);
b.SetBool(SignField, sign); // writing sign
// --- Regime ---
int regimeSize;
if (regime >= 0)
{
regimeSize = regime + 1;
}
else
{
regimeSize = -regime;
}
int regimePosition = size - 1 - regimeSize;
int regimeTerminatorPosition = regimePosition - 1;
b.AddField(RegimeField, regimePosition, regimeSize);
for (int i = 0; i < regimeSize; ++i)
{
b[regimePosition + i] = regime >= 0; // writing regime
}
b.AddField(TerminatorField, regimeTerminatorPosition, 1);
b[regimeTerminatorPosition] = regime < 0; // writing regime terminator
// --- Exponent ---
int exponentSize = Math.Min(es, size - 2 - regimeSize);
if (exponentSize > 0)
{
int exponentPosition = regimeTerminatorPosition - exponentSize;
b.AddField(ExponentField, exponentPosition, exponentSize);
b.SetUint(ExponentField, (uint)exponent);
}
// --- Fraction ---
int fractionSize = Math.Max(0, size - 2 - regimeSize - exponentSize);
if (fractionSize > 0)
{
b.AddField(FractionField, 0, fractionSize);
b.SetUint(FractionField, (uint)fraction);
}
return(b);
}
public float ToFloat(out BitLattice fbits)
{
inexact = false;
fbits = new BitLattice(32);
// IEEE 754
int floatExpSize = 8;
int floatFracSize = 23;
fbits.AddField(SignField, fbits.Size - 1, 1);
fbits.AddField(ExponentField, fbits.Size - floatExpSize - 1, floatExpSize);
fbits.AddField(FractionField, 0, floatFracSize);
int floatExpBias = 1 - (2 << (fbits.GetFieldLength(ExponentField) - 2)); // -127
int floatExp = FullExponent - floatExpBias;
if (floatExp > (1 << floatExpSize) - 1)
{
floatExp = (1 << floatExpSize) - 1;
inexact = true;
}
fbits.SetBool(SignField, sign);
fbits.SetUint(ExponentField, (uint)floatExp);
int fracResize = floatFracSize - FractionSize;
uint floatFrac = fraction;
if (fracResize < 0)
{
inexact = true;
floatFrac >>= (-fracResize);
}
else if (fracResize > 0)
{
floatFrac <<= fracResize;
}
fbits.SetUint(FractionField, (uint)floatFrac);
return(BitConverter.ToSingle(fbits.ToBytes()));
}
