use super::functions::ImplicitSurface;
use super::functions::{clamp, mix, normalize};
use super::types::CsgSmoothUnion;
impl ImplicitSurface for CsgSmoothUnion {
fn sdf(&self, p: [f64; 3]) -> f64 {
let da = self.a.sdf(p);
let db = self.b.sdf(p);
let h = clamp(0.5 + 0.5 * (db - da) / self.k, 0.0, 1.0);
mix(db, da, h) - self.k * h * (1.0 - h)
}
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])
}
}