float_math.h File Reference

Floating Point Math Utilities. More...

#include <math.h>
#include <stdint.h>

Go to the source code of this file.

Classes
union	f32_t
struct	f32pair_t

Macros
Constants
#define	M_E   2.718281828459045f
#define	M_LOG2E   1.44269504088896f
#define	M_LOG10E   0.4342944819032518f
#define	M_LN2   0.6931471805599453094f
#define	M_LN10   2.30258509299404568402f
#define	M_PI   3.141592653589793f
#define	M_TWOPI   6.283185307179586f
#define	M_PI_2   1.5707963267948966f
#define	M_PI_4   0.7853981633974483f
#define	M_1_PI   0.3183098861837907f
#define	M_2_PI   0.6366197723675814f
#define	M_4_PI   1.2732395447351627f
#define	M_1_TWOPI   0.15915494309189534f
#define	M_2_SQRTPI   1.1283791670955126f
#define	M_4_PI2   0.40528473456935109f
#define	M_SQRT2   1.41421356237309504880f
#define	M_1_SQRT2   0.7071067811865475f
Macros
#define	F32_FRAC_MASK   ((1L<<23)-1)
#define	F32_EXP_MASK   (((1L<<9)-1)<<23)
#define	F32_SIGN_MASK   (0x80000000)
#define	f32_frac_bits(f)   ((f) & F32_FRAC_MASK)
#define	f32_exp_bits(f)   ((f) & F32_EXP_MASK)
#define	f32_sign_bit(f)   ((f) & F32_SIGN_MASK)

Functions
Types
static f32pair_t	f32pair (const float a, const float b)
	Make a float pair.
Operations
static float	fsel (const float a, const float b, const float c)
	FSEL construct.
static uint8_t	fselb (const float a)
	FSEL boolean construct.
static uint8_t	float_is_neg (const f32_t f)
	Sign bit check.
static int32_t	float_mantissa (f32_t f)
	Obtain mantissa.
static int32_t	float_exponent (f32_t f)
	Obtain exponent.
static f32pair_t	f32pair_add (const f32pair_t p0, const f32pair_t p1)
	Pair-wise addition.
static f32pair_t	f32pair_sub (const f32pair_t p0, const f32pair_t p1)
	Pair-wise subtraction.
static f32pair_t	f32pair_addscal (const f32pair_t p, const float scl)
	Pair-wise scalar addition.
static f32pair_t	f32pair_mul (const f32pair_t p0, const f32pair_t p1)
	Pair-wise product.
static f32pair_t	f32pair_mulscal (const f32pair_t p, const float scl)
	Pair-wise scalar product.
static f32pair_t	f32pair_linint (const float fr, const f32pair_t p0, const f32pair_t p1)
	Pair-wise linear interpolation.
static float	si_copysignf (const float x, const float y)
	Return x with sign of y applied.
static float	si_fabsf (float x)
	Absolute value.
static float	si_floorf (float x)
	Floor function.
static float	si_ceilf (float x)
	Ceiling function.
static float	si_roundf (float x)
	Round to nearest integer.
static float	clampfsel (const float min, float x, const float max)
static float	clampminfsel (const float min, const float x)
static float	clampmaxfsel (const float x, const float max)
static float	clipmaxf (const float x, const float m)
	Clip upper bound of x to m (inclusive)
static float	clipminf (const float m, const float x)
	Clip lower bound of x to m (inclusive)
static float	clipminmaxf (const float min, const float x, const float max)
	Clip x to min and max (inclusive)
static float	clip0f (const float x)
	Clip lower bound of x to 0.f (inclusive)
static float	clip1f (const float x)
	Clip upper bound of x to 1.f (inclusive)
static float	clip01f (const float x)
	Clip x to [0.f, 1.f] (inclusive)
static float	clipm1f (const float x)
	Clip lower bound of x to -1.f (inclusive)
static float	clip1m1f (const float x)
	Clip x to [-1.f, 1.f] (inclusive)
Faster direct approximations of common trigonometric functions
Note Use with care. Depending on optimizations and targets these can provide little benefit over libc versions.
static float	fastsinf (float x)
	"Fast" sine approximation, valid for x in [-M_PI, M_PI] More...
static float	fastersinf (float x)
	"Faster" sine approximation, valid for x in [-M_PI, M_PI] More...
static float	fastsinfullf (float x)
	"Fast" sine approximation, valid on full x domain More...
static float	fastersinfullf (float x)
	"Faster" sine approximation, valid on full x domain More...
static float	fastcosf (float x)
	"Fast" cosine approximation, valid for x in [-M_PI, M_PI] More...
static float	fastercosf (float x)
	"Faster" cosine approximation, valid for x in [-M_PI, M_PI] More...
static float	fastcosfullf (float x)
	"Fast" cosine approximation, valid on full x domain More...
static float	fastercosfullf (float x)
	"Faster" cosine approximation, valid on full x domain More...
static float	fasttanf (float x)
	"Fast" tangent approximation, valid for x in [-M_PI_2, M_PI_2] More...
static float	fastertanf (float x)
	"Faster" tangent approximation, valid for x in [-M_PI_2, M_PI_2] More...
static float	fasttanfullf (float x)
	"Fast" tangent approximation, valid on full x domain, except where tangent diverges. More...
static float	fastertanfullf (float x)
	"Faster" tangent approximation, valid on full x domain, except where tangent diverges. More...
static float	fastlog2f (float x)
	"Fast" log base 2 approximation, valid for positive x as precision allows. More...
static float	fasterlog2f (float x)
	"Faster" log base 2 approximation, valid for positive x as precision allows. More...
static float	fastlogf (float x)
	"Fast" natural logarithm approximation, valid for positive x as precision allows. More...
static float	fasterlogf (float x)
	"Fast" natural logarithm approximation, valid for positive x as precision allows. More...
static float	fastpow2f (float p)
	"Fast" power of 2 approximation, valid for x in [ -126, ... More...
static float	fasterpow2f (float p)
	"Faster" power of 2 approximation, valid for x in [ -126, ... More...
static float	fastpowf (float x, float p)
	"Fast" x to the power of p approximation More...
static float	fasterpowf (float x, float p)
	"Faster" x to the power of p approximation More...
static float	fastexpf (float p)
	"Fast" exponential approximation, valid for x in [ ~ -87, ... More...
static float	fasterexpf (float p)
	"Faster" exponential approximation, valid for x in [ ~ -87, ... More...
static float	fasteratan2f (float y, float x)
	atan2 approximation More...
static float	fastertanhf (float x)
	Hyperbolic tangent approximation. More...
Useful Conversions
Note These can be very slow, use with caution. Should use table lookups in performance critical sections.
static float	ampdbf (const float amp)
	Amplitude to dB. More...
static float	fasterampdbf (const float amp)
	"Faster" Amplitude to dB
static float	dbampf (const float db)
	dB to ampltitude
static float	fasterdbampf (const float db)
	"Faster" dB to ampltitude
Interpolations
Todo: Add cubic/spline interpolations
static float	linintf (const float fr, const float x0, const float x1)
	Linear interpolation.
static float	cosintf (const float fr, const float x0, const float x1)
	Cosine interpolation.

Detailed Description

Floating Point Math Utilities.

Definition in file float_math.h.