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Fixed Point Arithmetic

include/math/fixed.h View source View on GitHub

Functions

Section titled “Functions”

fx_parse

Section titled “fx_parse”
fx32_32_t fx_parse(const char *str, char **endptr)
source

strtol style

fx_add

Section titled “fx_add”
fx32_32_t fx_add(fx32_32_t a, fx32_32_t b)
source

fx_sub

Section titled “fx_sub”
fx32_32_t fx_sub(fx32_32_t a, fx32_32_t b)
source

fx_mul

Section titled “fx_mul”
fx32_32_t fx_mul(fx32_32_t a, fx32_32_t b)
source

fx_div

Section titled “fx_div”
fx32_32_t fx_div(fx32_32_t a, fx32_32_t b)
source

fx_from_int

Section titled “fx_from_int”
fx32_32_t fx_from_int(int64_t x)
source

fx_to_int

Section titled “fx_to_int”
int64_t fx_to_int(fx32_32_t x)
source

fx_min

Section titled “fx_min”
fx32_32_t fx_min(fx32_32_t a, fx32_32_t b)
source

fx_max

Section titled “fx_max”
fx32_32_t fx_max(fx32_32_t a, fx32_32_t b)
source

fx_clamp

Section titled “fx_clamp”
fx32_32_t fx_clamp(fx32_32_t x, fx32_32_t lo, fx32_32_t hi)
source

fx_pow_i32

Section titled “fx_pow_i32”
fx32_32_t fx_pow_i32(fx32_32_t base, int exp)
source

fx_sqrt

Section titled “fx_sqrt”
fx32_32_t fx_sqrt(fx32_32_t x)
source

fx_ceil

Section titled “fx_ceil”
fx32_32_t fx_ceil(fx32_32_t x)
source

Use two’s complement to branchlessly floor for both signs

fx_floor

Section titled “fx_floor”
fx32_32_t fx_floor(fx32_32_t x)
source

fx_map

Section titled “fx_map”
fx32_32_t fx_map(
    fx32_32_t value,
    fx32_32_t from_low,
    fx32_32_t from_high,
    fx32_32_t to_low,
    fx32_32_t to_high
)
source

fx_lerp

Section titled “fx_lerp”
fx32_32_t fx_lerp(fx32_32_t a, fx32_32_t b, fx32_32_t t)
source

fx_round_up

Section titled “fx_round_up”
fx32_32_t fx_round_up(fx32_32_t x, fx32_32_t multiple)
source

fx_round_down

Section titled “fx_round_down”
fx32_32_t fx_round_down(fx32_32_t x, fx32_32_t multiple)
source

fx_poly_eval

Section titled “fx_poly_eval”
fx32_32_t fx_poly_eval(fx32_32_t x, const fx32_32_t *c, int n)
source

Extended fixed-point math functions implemented in kernel/math/fixed.c

fx_exp

Section titled “fx_exp”
fx32_32_t fx_exp(fx32_32_t x)
source

fx_ln

Section titled “fx_ln”
fx32_32_t fx_ln(fx32_32_t x)
source

fx_sin

Section titled “fx_sin”
fx32_32_t fx_sin(fx32_32_t angle)
source

fx_cos

Section titled “fx_cos”
fx32_32_t fx_cos(fx32_32_t angle)
source

fx_sincos

Section titled “fx_sincos”
void fx_sincos(
    fx32_32_t angle,
    fx32_32_t *sin_out,
    fx32_32_t *cos_out
)
source

fx_exp_series

Section titled “fx_exp_series”
fx32_32_t fx_exp_series(fx32_32_t x)
source

fx_ln_series

Section titled “fx_ln_series”
fx32_32_t fx_ln_series(fx32_32_t x)
source

fx_sin_series

Section titled “fx_sin_series”
fx32_32_t fx_sin_series(fx32_32_t angle)
source

fx_cos_series

Section titled “fx_cos_series”
fx32_32_t fx_cos_series(fx32_32_t angle)
source

fx_sincos_series

Section titled “fx_sincos_series”
void fx_sincos_series(
    fx32_32_t angle,
    fx32_32_t *sin_out,
    fx32_32_t *cos_out
)
source

Macros

Section titled “Macros”

FX_ZERO

Section titled “FX_ZERO”
#define FX_ZERO ((fx32_32_t) 0)
source

FX_ONE

Section titled “FX_ONE”
#define FX_ONE ((fx32_32_t) (1LL << 32))
source

FX_HALF

Section titled “FX_HALF”
#define FX_HALF ((fx32_32_t) (1LL << 31))
source

FP_PI

Section titled “FP_PI”
#define FP_PI 3.14159265358979323846
source

FX_PI

Section titled “FX_PI”
#define FX_PI FX(3.14159265358979323846)
source

FX_E

Section titled “FX_E”
#define FX_E FX(2.71828182845045235360)
source

FX

Section titled “FX”
#define FX(x)
source

Cast truncates towards zero, so we need to round

Expansion
#define FX(x) ((fx32_32_t) ((x) * 4294967296.0 + ((x) < 0 ? -0.5 : 0.5)))

FX_FROM_RATIO

Section titled “FX_FROM_RATIO”
#define FX_FROM_RATIO(n, d)
source
Expansion
#define FX_FROM_RATIO(n, d) ((fx32_32_t) (((__int128) (n) << 32) / (d)))