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feat(math): added a few more interpolation functions

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lisk77 2025-07-29 15:45:01 +02:00
parent 05764965b3
commit 92055d62a5
1 changed files with 46 additions and 12 deletions
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34
crates/comet_math/src/interpolation.rs
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@ -1,33 +1,67 @@
use std::f32::consts::PI;
#[inline(always)]
pub fn lerp(a: f32, b: f32, t: f32) -> f32 {
a * (1.0 - t) + b * t
}
#[inline(always)]
pub fn inverse_lerp(a: f32, b: f32, x: f32) -> f32 {
(x - a) / (b - a)
}
#[inline(always)]
pub fn smoothstep(edge0: f32, edge1: f32, x: f32) -> f32 {
let t = ((x - edge0) / (edge1 - edge0)).clamp(0.0, 1.0);
t * t * (3.0 - 2.0 * t)
}
#[inline(always)]
pub fn inverse_smoothstep(v: f32) -> f32 {
(0.5 - (0.5 - v.sqrt()).sqrt()).clamp(0.0, 1.0)
}
#[inline(always)]
pub fn smootherstep(edge0: f32, edge1: f32, x: f32) -> f32 {
let t = ((x - edge0) / (edge1 - edge0)).clamp(0.0, 1.0);
t * t * t * (t * (t * 6.0 - 15.0) + 10.0)
}
#[inline(always)]
pub fn cosine_interpolate(a: f32, b: f32, x: f32) -> f32 {
let ft = x * PI;
let f = (1.0 - ft.cos()) * 0.5;
a * (1.0 - f) + b * f
}
#[inline(always)]
pub fn inverse_cosine_interpolate(a: f32, b: f32, v: f32) -> f32 {
((1.0 - 2.0 * (v - a) / (b - a)).acos()) / PI
}
#[inline(always)]
pub fn cubic_interpolate(a: f32, b: f32, c: f32, d: f32, t: f32) -> f32 {
let p = (d - c) - (a - b);
let q = (a - b) - p;
let r = c - a;
let s = b;
p * t.powi(3) + q * t.powi(2) + r * t + s
}
#[inline(always)]
pub fn hermite_interpolate(p0: f32, p1: f32, m0: f32, m1: f32, t: f32) -> f32 {
let t2 = t * t;
let t3 = t2 * t;
(2.0 * t3 - 3.0 * t2 + 1.0) * p0
+ (t3 - 2.0 * t2 + t) * m0
+ (-2.0 * t3 + 3.0 * t2) * p1
+ (t3 - t2) * m1
}
#[inline(always)]
pub fn catmull_rom_interpolate(p0: f32, p1: f32, p2: f32, p3: f32, t: f32) -> f32 {
0.5 * ((2.0 * p1)
+ (-p0 + p2) * t
+ (2.0 * p0 - 5.0 * p1 + 4.0 * p2 - p3) * t * t
+ (-p0 + 3.0 * p1 - 3.0 * p2 + p3) * t * t * t)
}