/// <summary>
/// Constructs an instance of this class with the value of the argument.
/// </summary>
/// <param name="value">A <b>float</b> value.</param>
public glFloat16(float value)
{
#if !SLOW_BUT_PLATTFORM_INDEPENDENT_FLOAT_CONVERSION
// Get bits as uint
SingleUInt32Union union = new SingleUInt32Union();
union.single = value;
uint ivalue = union.uint32;
// Signed zero?
if ((ivalue & 0x7FFFFFFF) == 0)
{
Value = (ushort)(ivalue >> 16); // Set signed zero
return;
}
uint maskedSign = ivalue & 0x80000000;
uint maskedExpo = ivalue & 0x7F800000;
// Denormalized number? (this would underflow anyway)
if (maskedExpo == 0)
{
Value = (ushort)(maskedSign >> 16); // Set signed zero
return;
}
uint maskedMant = ivalue & 0x007FFFFF;
// Infinity or NaN? (all exponent bits set)
if (maskedExpo == 0x7F800000)
{
// NaN?
if (maskedMant != 0)
{
Value = NaN;
}
else
{
Value = (ushort)((maskedSign >> 16) | ExponentMask); // Set signed infinity
}
return;
}
// Normalized number
Value = (ushort)(maskedSign >> 16);
int iExponent = ((int)maskedExpo >> 23) - 127 + 15; // Convert exponent from float range to 16-bit float range
// Overflow? (exponent out of range)
if (iExponent >= 0x1F)
{
Value |= ExponentMask; // Set signed infinity
return;
}
// Underflow? (exponent out of range)
if (iExponent <= 0)
{
// No mantissa bits left
if ((14 - iExponent) > 24)
{
return;
}
// Make denormalized number
maskedMant |= 0x00800000; // Add the leading one digit
ushort denormMantissa = (ushort)(maskedMant >> (14 - iExponent));
// Check for rounding
if (((maskedMant >> (13 - iExponent)) & 1) != 0)
{
denormMantissa++;
}
Value |= denormMantissa;
return;
}
Value |= (ushort)(iExponent << 10);
Value |= (ushort)(maskedMant >> 13);
// Check for rounding
if ((maskedMant & 0x00001000) != 0)
{
Value++;
}
#else
if (float.IsNaN(value))
{
Value = NaN;
return;
}
if (float.IsPositiveInfinity(value))
{
Value = PositiveInfinity;
return;
}
if (float.IsNegativeInfinity(value))
{
Value = NegativeInfinity;
return;
}
if (value < MinValue)
{
value = MinValue;
}
else if (value > MaxValue)
{
value = MaxValue;
}
Value = 0;
if (value < 0)
{
value = Math.Abs(value);
Value = SignMask;
}
int exp = (int)(Math.Log(value, 2) + 15);
if (exp <= 0)
{
Value |= (ushort)(value * (1 << 24) + 0.5f);
}
else if (exp > 25)
{
Value |= (ushort)((exp << 10) + (int)(value / (1 << (exp - 25)) - 1023.5f));
}
else
{
Value |= (ushort)((exp << 10) + (int)(value * (1 << (25 - exp)) - 1023.5f));
}
#endif
}
/// <summary>
/// Constructs an instance of this class with the value of the argument.
/// </summary>
/// <param name="value">A <b>float</b> value.</param>
public glUFloat10(float value)
{
#if !SLOW_BUT_PLATTFORM_INDEPENDENT_FLOAT_CONVERSION
// Get bits as uint
SingleUInt32Union union = new SingleUInt32Union();
union.single = value;
uint ivalue = union.uint32;
Value = 0;
// Zero?
if ((ivalue & 0x7FFFFFFF) == 0)
{
return;
}
uint maskedExpo = ivalue & 0x7F800000;
// Denormalized number? (this would underflow anyway)
if (maskedExpo == 0)
{
return;
}
uint maskedMant = ivalue & 0x007FFFFF;
// Infinity or NaN? (all exponent bits set)
if (maskedExpo == 0x7F800000)
{
// NaN?
if (maskedMant != 0)
{
Value = NaN;
}
else if ((ivalue & 0x80000000) == 0)
{
Value = Infinity; // Negative infinity => 0
}
return;
}
// Negative?
if ((ivalue & 0x80000000) != 0)
{
return;
}
// Normalized number
int iExponent = ((int)maskedExpo >> 23) - 127 + 15; // Convert exponent from float range to 16-bit float range
// Overflow? (exponent out of range)
if (iExponent >= 0x1F)
{
Value = Infinity;
return;
}
// Underflow? (exponent out of range)
if (iExponent <= 0)
{
// No mantissa bits left
if ((19 - iExponent) > 24)
{
return;
}
// Make denormalized number
maskedMant |= 0x00800000; // Add the leading one digit
ushort denormMantissa = (ushort)(maskedMant >> (19 - iExponent));
// Check for rounding
if (((maskedMant >> (18 - iExponent)) & 1) != 0)
{
denormMantissa++;
}
Value |= denormMantissa;
return;
}
Value |= (ushort)(iExponent << 5);
Value |= (ushort)(maskedMant >> 18);
// Check for rounding
if ((maskedMant & 0x00020000) != 0)
{
Value++;
}
#else
if (float.IsNaN(value))
{
Value = NaN;
return;
}
if (float.IsInfinity(value))
{
Value = Infinity;
return;
}
if (value < MinValue)
{
value = MinValue;
}
else if (value > MaxValue)
{
value = MaxValue;
}
int exp = (int)(Math.Log(value, 2) + 15);
if (exp <= 0)
{
Value = (ushort)(value * (1 << 19) + 0.5f);
}
else if (exp > 20)
{
Value = (ushort)((exp << 5) + (int)(value / (1 << (exp - 20)) - 31.5f));
}
else
{
Value = (ushort)((exp << 5) + (int)(value * (1 << (20 - exp)) - 31.5f));
}
#endif
}
