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FelsFels

std.math

f32 vectors, rects and scalar helpers for games; v2_/v3_ prefixes

PI

Section titled “PI”
pub PI      :: 3.14159265f32

constants

TAU

Section titled “TAU”
pub TAU     :: 6.28318531f32

DEG2RAD

Section titled “DEG2RAD”
pub DEG2RAD :: 0.01745329f32

RAD2DEG

Section titled “RAD2DEG”
pub RAD2DEG :: 57.2957795f32

lerp

Section titled “lerp”
pub lerp :: fn(a: f32, b: f32, t: f32) -> f32

a at t=0, b at t=1

approach

Section titled “approach”
pub approach :: fn(cur: f32, tgt: f32, step: f32) -> f32

toward tgt by at most step; no overshoot

signf

Section titled “signf”
pub signf :: fn(x: f32) -> f32

-1, 0 or +1

deg2rad

Section titled “deg2rad”
pub deg2rad :: fn(deg: f32) -> f32

rad2deg

Section titled “rad2deg”
pub rad2deg :: fn(rad: f32) -> f32

sin

Section titled “sin”
pub sin :: fn(x: f32) -> f32

cos

Section titled “cos”
pub cos :: fn(x: f32) -> f32

tan

Section titled “tan”
pub tan :: fn(x: f32) -> f32

wrapf

Section titled “wrapf”
pub wrapf :: fn(x: f32, lo: f32, hi: f32) -> f32

into [lo, hi)

Vec2

Section titled “Vec2”
pub Vec2 :: struct {
    x: f32,
    y: f32,
}

v2

Section titled “v2”
pub v2 :: fn(x: f32, y: f32) -> Vec2

v2_zero

Section titled “v2_zero”
pub v2_zero :: fn() -> Vec2

v2_splat

Section titled “v2_splat”
pub v2_splat :: fn(s: f32) -> Vec2

v2_add

Section titled “v2_add”
pub v2_add :: fn(a: Vec2, b: Vec2) -> Vec2

v2_sub

Section titled “v2_sub”
pub v2_sub :: fn(a: Vec2, b: Vec2) -> Vec2

v2_mul

Section titled “v2_mul”
pub v2_mul :: fn(a: Vec2, b: Vec2) -> Vec2

v2_scale

Section titled “v2_scale”
pub v2_scale :: fn(a: Vec2, s: f32) -> Vec2

v2_neg

Section titled “v2_neg”
pub v2_neg :: fn(a: Vec2) -> Vec2

v2_dot

Section titled “v2_dot”
pub v2_dot :: fn(a: Vec2, b: Vec2) -> f32

v2_len2

Section titled “v2_len2”
pub v2_len2 :: fn(a: Vec2) -> f32

v2_len

Section titled “v2_len”
pub v2_len :: fn(a: Vec2) -> f32

v2_dist2

Section titled “v2_dist2”
pub v2_dist2 :: fn(a: Vec2, b: Vec2) -> f32

v2_dist

Section titled “v2_dist”
pub v2_dist :: fn(a: Vec2, b: Vec2) -> f32

v2_normalize

Section titled “v2_normalize”
pub v2_normalize :: fn(a: Vec2) -> Vec2

zero vector if a is ~zero

v2_lerp

Section titled “v2_lerp”
pub v2_lerp :: fn(a: Vec2, b: Vec2, t: f32) -> Vec2

v2_perp

Section titled “v2_perp”
pub v2_perp :: fn(a: Vec2) -> Vec2

90 deg counter-clockwise

v2_rotate

Section titled “v2_rotate”
pub v2_rotate :: fn(a: Vec2, rad: f32) -> Vec2

by rad radians

v2_from_angle

Section titled “v2_from_angle”
pub v2_from_angle :: fn(rad: f32) -> Vec2

unit vector at rad; 0 = +x

Vec3

Section titled “Vec3”
pub Vec3 :: struct {
    x: f32,
    y: f32,
    z: f32,
}

v3

Section titled “v3”
pub v3 :: fn(x: f32, y: f32, z: f32) -> Vec3

v3_add

Section titled “v3_add”
pub v3_add :: fn(a: Vec3, b: Vec3) -> Vec3

v3_sub

Section titled “v3_sub”
pub v3_sub :: fn(a: Vec3, b: Vec3) -> Vec3

v3_scale

Section titled “v3_scale”
pub v3_scale :: fn(a: Vec3, s: f32) -> Vec3

v3_dot

Section titled “v3_dot”
pub v3_dot :: fn(a: Vec3, b: Vec3) -> f32

v3_len

Section titled “v3_len”
pub v3_len :: fn(a: Vec3) -> f32

v3_cross

Section titled “v3_cross”
pub v3_cross :: fn(a: Vec3, b: Vec3) -> Vec3

v3_normalize

Section titled “v3_normalize”
pub v3_normalize :: fn(a: Vec3) -> Vec3

Rect

Section titled “Rect”
pub Rect :: struct {
    x: f32,
    y: f32,
    w: f32,
    h: f32,
}

axis-aligned rect for sprites, UI, collisions

rect

Section titled “rect”
pub rect :: fn(x: f32, y: f32, w: f32, h: f32) -> Rect

rect_contains

Section titled “rect_contains”
pub rect_contains :: fn(r: Rect, px: f32, py: f32) -> bool

rect_overlaps

Section titled “rect_overlaps”
pub rect_overlaps :: fn(a: Rect, b: Rect) -> bool

AABB overlap

rect_center

Section titled “rect_center”
pub rect_center :: fn(r: Rect) -> Vec2

gcd

Section titled “gcd”
pub gcd :: fn(a: u64, b: u64) -> u64

gcd(0, 0) is 0

lcm

Section titled “lcm”
pub lcm :: fn(a: u64, b: u64) -> ?u64

0 when either is 0; null on u64 overflow

ipow

Section titled “ipow”
pub ipow :: fn(base: u64, exp: u32) -> ?u64

null on u64 overflow

isqrt

Section titled “isqrt”
pub isqrt :: fn(n: u64) -> u64

floor(sqrt(n))

div_ceil

Section titled “div_ceil”
pub div_ceil :: fn(a: u64, b: u64) -> u64

rounds up; b != 0

align_up

Section titled “align_up”
pub align_up :: fn(x: u64, align: u64) -> u64

align must be a power of two

align_down

Section titled “align_down”
pub align_down :: fn(x: u64, align: u64) -> u64

align must be a power of two

log2_floor

Section titled “log2_floor”
pub log2_floor :: fn(x: u64) -> u32

floor(log2(x)); 0 for 0

next_power_of_two

Section titled “next_power_of_two”
pub next_power_of_two :: fn(x: u64) -> ?u64

smallest power of two >= x (1 for 0); null past 2^63

mod_floor

Section titled “mod_floor”
pub mod_floor :: fn(a: i64, b: i64) -> i64

remainder with the sign of b: mod_floor(-7, 3) == 2; b != 0