imath: Integer Math functions

This modules provides some integer-only math functions. More...

Detailed Description

This modules provides some integer-only math functions.

They can be used when no FPU is available or no exact precision is needed.

Author

Karl Fessel karl..nosp@m.fess.nosp@m.el@ov.nosp@m.gu.d.nosp@m.e

Macros
#define	SINI_PERIOD   0x8000
	Period of the fast_sini() function.
#define	SINI_MAX   0x1000
	Max value of the fast_sini() function.
#define	SINI_MIN   -0x1000
	Min value of the fast_sini() function.

Functions
static int32_t	_ihelp (int32_t x)
	Internal fast_sini/fast_cosi helper function.
static int32_t	fast_sini (int32_t x)
	A sine approximation via a fourth-order cosine approx.
static int32_t	fast_cosi (int32_t x)
	A a fourth-order cosine approx.
static unsigned	sqrti (unsigned x)
	Square root of an integer.
static uint32_t	powi (unsigned x, unsigned y)
	Returns the value of x to the power of y.

Macro Definition Documentation

SINI_MAX

#define SINI_MAX   0x1000

Max value of the fast_sini() function.

Definition at line 31 of file imath.h.

SINI_MIN

#define SINI_MIN   -0x1000

Min value of the fast_sini() function.

Definition at line 32 of file imath.h.

SINI_PERIOD

#define SINI_PERIOD   0x8000

Period of the fast_sini() function.

Definition at line 30 of file imath.h.

Function Documentation

_ihelp()

static int32_t _ihelp ( int32_t  x )

inlinestatic

Internal fast_sini/fast_cosi helper function.

Definition at line 43 of file imath.h.

fast_cosi()

static int32_t fast_cosi ( int32_t  x )

inlinestatic

A a fourth-order cosine approx.

source: https://www.coranac.com/2009/07/sines/

Parameters

x	angle (with 2^15 units/circle)

Returns

sine value (-2^12 ≤ y ≤ 2^12)

Definition at line 86 of file imath.h.

fast_sini()

static int32_t fast_sini ( int32_t  x )

inlinestatic

A sine approximation via a fourth-order cosine approx.

source: https://www.coranac.com/2009/07/sines/

Parameters

x	angle (with 2^15 units/circle)

Returns

sine value (-2^12 ≤ y ≤ 2^12)

Definition at line 69 of file imath.h.

powi()

static uint32_t powi ( unsigned  x, unsigned  y  )

inlinestatic

Returns the value of x to the power of y.

Parameters

x	base
y	exponent

Returns

x^y

Definition at line 128 of file imath.h.

sqrti()

static unsigned sqrti ( unsigned  x )

inlinestatic

Square root of an integer.

Parameters

x	unsigned integer value

Returns

square root of x

Definition at line 102 of file imath.h.