wxWidgets/interface/wx/math.h
Vadim Zeitlin 7c6f290995 Document wxMulDivInt32() and add a test for it
This function exists since always and is probably already used outside
wx, so make it officially public and add at least a trivial unit test
for it.
2021-07-13 23:05:16 +01:00

130 lines
3.5 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: math.h
// Purpose: interface of global functions
// Author: wxWidgets team
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
/** @addtogroup group_funcmacro_math */
//@{
/**
Returns a non-zero value if @a x is neither infinite nor NaN (not a
number), returns 0 otherwise.
@header{wx/math.h}
*/
int wxFinite(double x);
/**
Returns the greatest common divisor of the two given numbers.
@since 3.1.0
@header{wx/math.h}
*/
unsigned int wxGCD(unsigned int u, unsigned int v);
/**
Returns a non-zero value if x is NaN (not a number), returns 0 otherwise.
@header{wx/math.h}
*/
bool wxIsNaN(double x);
/**
Converts the given array of 10 bytes (corresponding to 80 bits) to
a float number according to the IEEE floating point standard format
(aka IEEE standard 754).
@see wxConvertToIeeeExtended() to perform the opposite operation
*/
wxFloat64 wxConvertFromIeeeExtended(const wxInt8 *bytes);
/**
Converts the given floating number @a num in a sequence of 10 bytes
which are stored in the given array @a bytes (which must be large enough)
according to the IEEE floating point standard format
(aka IEEE standard 754).
@see wxConvertFromIeeeExtended() to perform the opposite operation
*/
void wxConvertToIeeeExtended(wxFloat64 num, wxInt8 *bytes);
/**
Convert degrees to radians.
This function simply returns its argument multiplied by @c M_PI/180 but is
more readable than writing this expression directly.
@see wxRadToDeg()
@since 3.1.0
*/
double wxDegToRad(double deg);
/**
Convert radians to degrees.
This function simply returns its argument multiplied by @c 180/M_PI but is
more readable than writing this expression directly.
@see wxDegToRad()
@since 3.1.0
*/
double wxRadToDeg(double rad);
/**
Count the number of trailing zeros.
This function returns the number of trailing zeros in the binary notation
of its argument @a x. E.g. for @a x equal to 4, or 0b100, the return value
is 2.
@param x Strictly positive, i.e. non-zero, 32 bit number.
@since 3.1.2
*/
unsigned int wxCTZ(wxUint32 x);
/**
Small wrapper around std::lround().
This function exists for compatibility, as it was more convenient than
std::round() before C++11. Use std::lround() in the new code.
It is defined for all floating point types @c T and can be also used with
integer types for compatibility, but such use is deprecated -- simply
remove the calls to wxRound() from your code if you're using it with
integer types, it is unnecessary in this case.
*/
template <typename T>
int wxRound(T x);
/**
Returns true if both double values are identical. This is
only reliable if both values have been assigned the same
value.
*/
bool wxIsSameDouble(double x, double y);
/**
Return true of @a x is exactly zero. This is only reliable
if it has been assigned 0.
*/
bool wxIsNullDouble(double x);
/**
Computes the product of a number with a fraction with rounding.
This function returns @c n*numerator/denominator rounding the result. It is
similar to the standard Win32 @c MulDiv() function and, in fact, is
implemented by calling it under MSW, where @c wx/msw/wrapwin.h must be
included in addition to @c wx/math.h for it to be used.
*/
int wxMulDivInt32(int n, int numerator, int denominator);
//@}