Files
veloren/world/src/util/fast_noise.rs
2024-02-24 23:09:02 +01:00

119 lines
3.8 KiB
Rust

use super::{RandomField, Sampler};
use std::{f32, ops::Add};
use vek::*;
pub struct FastNoise {
noise: RandomField,
}
impl FastNoise {
pub const fn new(seed: u32) -> Self {
Self {
noise: RandomField::new(seed),
}
}
#[allow(clippy::excessive_precision)] // TODO: Pending review in #587
fn noise_at(&self, pos: Vec3<i32>) -> f32 {
(self.noise.get(pos) & 4095) as f32 * 0.000244140625
}
}
impl Sampler<'static> for FastNoise {
type Index = Vec3<f64>;
type Sample = f32;
fn get(&self, pos: Self::Index) -> Self::Sample {
// let align_pos = pos.map(|e| e.floor());
// let near_pos = align_pos.map(|e| e as i32);
// let v000 = self.noise_at(near_pos + Vec3::new(0, 0, 0));
// let v100 = self.noise_at(near_pos + Vec3::new(1, 0, 0));
// let v010 = self.noise_at(near_pos + Vec3::new(0, 1, 0));
// let v110 = self.noise_at(near_pos + Vec3::new(1, 1, 0));
// let v001 = self.noise_at(near_pos + Vec3::new(0, 0, 1));
// let v101 = self.noise_at(near_pos + Vec3::new(1, 0, 1));
// let v011 = self.noise_at(near_pos + Vec3::new(0, 1, 1));
// let v111 = self.noise_at(near_pos + Vec3::new(1, 1, 1));
// let factor = (pos - align_pos).map(|e| e as f32);
// let v00 = v000 + factor.z * (v001 - v000);
// let v10 = v010 + factor.z * (v011 - v010);
// let v01 = v100 + factor.z * (v101 - v100);
// let v11 = v110 + factor.z * (v111 - v110);
// let v0 = v00 + factor.y * (v01 - v00);
// let v1 = v10 + factor.y * (v11 - v10);
// (v0 + factor.x * (v1 - v0)) * 2.0 - 1.0
let near_pos = pos.map(|e| e.floor() as i32);
let v000 = self.noise_at(near_pos + Vec3::new(0, 0, 0));
let v100 = self.noise_at(near_pos + Vec3::new(1, 0, 0));
let v010 = self.noise_at(near_pos + Vec3::new(0, 1, 0));
let v110 = self.noise_at(near_pos + Vec3::new(1, 1, 0));
let v001 = self.noise_at(near_pos + Vec3::new(0, 0, 1));
let v101 = self.noise_at(near_pos + Vec3::new(1, 0, 1));
let v011 = self.noise_at(near_pos + Vec3::new(0, 1, 1));
let v111 = self.noise_at(near_pos + Vec3::new(1, 1, 1));
let factor = pos.map(|e| {
let f = e.fract().add(1.0).fract() as f32;
f.powi(2) * (3.0 - 2.0 * f)
});
let x00 = v000 + factor.x * (v100 - v000);
let x10 = v010 + factor.x * (v110 - v010);
let x01 = v001 + factor.x * (v101 - v001);
let x11 = v011 + factor.x * (v111 - v011);
let y0 = x00 + factor.y * (x10 - x00);
let y1 = x01 + factor.y * (x11 - x01);
(y0 + factor.z * (y1 - y0)) * 2.0 - 1.0
}
}
pub struct FastNoise2d {
noise: RandomField,
}
impl FastNoise2d {
pub const fn new(seed: u32) -> Self {
Self {
noise: RandomField::new(seed),
}
}
#[allow(clippy::excessive_precision)] // TODO: Pending review in #587
fn noise_at(&self, pos: Vec2<i32>) -> f32 {
(self.noise.get(Vec3::new(pos.x, pos.y, 0)) & 4095) as f32 * 0.000244140625
}
}
impl Sampler<'static> for FastNoise2d {
type Index = Vec2<f64>;
type Sample = f32;
fn get(&self, pos: Self::Index) -> Self::Sample {
let near_pos = pos.map(|e| e.floor() as i32);
let v00 = self.noise_at(near_pos + Vec2::new(0, 0));
let v10 = self.noise_at(near_pos + Vec2::new(1, 0));
let v01 = self.noise_at(near_pos + Vec2::new(0, 1));
let v11 = self.noise_at(near_pos + Vec2::new(1, 1));
let factor = pos.map(|e| {
let f = e.fract().add(1.0).fract() as f32;
f.powi(2) * (3.0 - 2.0 * f)
});
let v0 = v00 + factor.x * (v10 - v00);
let v1 = v01 + factor.x * (v11 - v01);
(v0 + factor.y * (v1 - v0)) * 2.0 - 1.0
}
}