neo::math::HalfFloat Class Reference

#include <math/half.h>

List of all members.

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Detailed Description

Type HalfFloat can represent positive and negative numbers, whose magnitude is between roughly 6.1e-5 and 6.5e+4, with a relative error of 9.8e-4; numbers smaller than 6.1e-5 can be represented with an absolute error of 6.0e-8. All integers from -2048 to +2048 can be represented exactly.

Type HalfFloat behaves (almost) like the built-in C++ floating point types. In arithmetic expressions, HalfFloat, float and double can be mixed freely. Here are a few examples:

HalfFloat a (3.5); float b (a + sqrt (a)); a += b; b += a; b = a + 7;

Conversions from HalfFloat to float are lossless; all HalfFloat numbers are exactly representable as floats.

Conversions from float to HalfFloat may not preserve the float's value exactly. If a float is not representable as a HalfFloat, the float value is rounded to the nearest representable HalfFloat. If a float value is exactly in the middle between the two closest representable HalfFloat values, then the float value is rounded to the HalfFloat with the greater magnitude.

Overflows during float-to-HalfFloat conversions cause arithmetic exceptions. An overflow occurs when the float value to be converted is too large to be represented as a HalfFloat, or if the float value is an infinity or a NAN.

The implementation of type HalfFloat makes the following assumptions about the implementation of the built-in C++ types:

float is an IEEE 754 single-precision number sizeof (float) == 4 sizeof (unsigned int) == sizeof (float) alignof (unsigned int) == alignof (float) sizeof (unsigned short) == 2

Public Member Functions
	HalfFloat ()
	Construct uninitialized number.
	HalfFloat (float val)
	Construct from 32-bit floating point number.
	operator float () const
	Convert to 32-bit floating point number.

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Constructor & Destructor Documentation

neo::math::HalfFloat::HalfFloat

(

float

val

)

[inline]

Parameters:

val

Value

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The documentation for this class was generated from the following file:

• half.h

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