use super::functions::ImplicitSurface;
use super::functions::normalize;
#[allow(unused_imports)]
use super::functions::*;
use super::types::SdfTorus;
impl ImplicitSurface for SdfTorus {
fn sdf(&self, p: [f64; 3]) -> f64 {
let q0 = (p[0] * p[0] + p[2] * p[2]).sqrt() - self.major_radius;
(q0 * q0 + p[1] * p[1]).sqrt() - self.minor_radius
}
fn gradient(&self, p: [f64; 3]) -> [f64; 3] {
const EPS: f64 = 1e-5;
let dx = self.sdf([p[0] + EPS, p[1], p[2]]) - self.sdf([p[0] - EPS, p[1], p[2]]);
let dy = self.sdf([p[0], p[1] + EPS, p[2]]) - self.sdf([p[0], p[1] - EPS, p[2]]);
let dz = self.sdf([p[0], p[1], p[2] + EPS]) - self.sdf([p[0], p[1], p[2] - EPS]);
normalize([dx, dy, dz])
}
}