Kodi Documentation 22.0
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MathUtils Namespace Reference

Math utility class. Note that the test() routine should return true for all implementations. More...

Functions

int round_int (double x)
 Round to nearest integer. This routine does fast rounding to the nearest integer. In the case (k + 0.5 for any integer k) we round up to k+1, and in all other instances we should return the nearest integer. Thus, { -1.5, -0.5, 0.5, 1.5 } is rounded to { -1, 0, 1, 2 }. It preserves the property that round(k) - round(k-1) = 1 for all doubles k.
 
int round_int (float x)
 Round to nearest integer.
 
int truncate_int (double x)
 Truncate to nearest integer. This routine does fast truncation to an integer. It should simply drop the fractional portion of the floating point number.
 
int64_t abs (int64_t a)
 
unsigned bitcount (unsigned v)
 
void hack ()
 
template<typename FloatT >
bool FloatEquals (FloatT f1, FloatT f2, FloatT maxDelta)
 
template<typename T , std::enable_if_t< std::is_floating_point< T >::value, bool > = true>
RoundF (const T value, const T multiple)
 Round a floating point number to nearest multiple.
 

Detailed Description

Math utility class. Note that the test() routine should return true for all implementations.

See http://ldesoras.free.fr/doc/articles/rounding_en.pdf for an explanation of the technique used on x86.

Function Documentation

◆ abs()

int64_t MathUtils::abs ( int64_t a)
inline

◆ bitcount()

unsigned MathUtils::bitcount ( unsigned v)
inline

◆ FloatEquals()

template<typename FloatT >
bool MathUtils::FloatEquals ( FloatT f1,
FloatT f2,
FloatT maxDelta )
inline

Compare two floating-point numbers for equality and regard them as equal if their difference is below a given threshold.

It is usually not useful to compare float numbers for equality with the standard operator== since very close numbers might have different representations.

◆ hack()

void MathUtils::hack ( )
inline

◆ round_int() [1/2]

int MathUtils::round_int ( double x)
inline

Round to nearest integer. This routine does fast rounding to the nearest integer. In the case (k + 0.5 for any integer k) we round up to k+1, and in all other instances we should return the nearest integer. Thus, { -1.5, -0.5, 0.5, 1.5 } is rounded to { -1, 0, 1, 2 }. It preserves the property that round(k) - round(k-1) = 1 for all doubles k.

Make sure MathUtils::test() returns true for each implementation.

See also
truncate_int, test

◆ round_int() [2/2]

int MathUtils::round_int ( float x)
inline

Round to nearest integer.

See also
truncate_int, test

◆ RoundF()

template<typename T , std::enable_if_t< std::is_floating_point< T >::value, bool > = true>
T MathUtils::RoundF ( const T value,
const T multiple )
inline

Round a floating point number to nearest multiple.

Parameters
valueThe value to round
multipleThe multiple
Returns
The rounded value

◆ truncate_int()

int MathUtils::truncate_int ( double x)
inline

Truncate to nearest integer. This routine does fast truncation to an integer. It should simply drop the fractional portion of the floating point number.

Make sure MathUtils::test() returns true for each implementation.

See also
round_int, test