58 lines
1.3 KiB
Rust
58 lines
1.3 KiB
Rust
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use super::Point3;
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use super::Ray;
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use super::Vec3;
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pub struct HitRecord {
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p: Point3,
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normal: Vec3,
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t: f64,
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}
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pub struct Sphere {
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center: Point3,
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radius: f64,
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}
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pub trait Hittable {
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fn hit(&self, r: Ray, t_min: f64, t_max: f64, rec: &mut HitRecord) -> bool;
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}
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impl Sphere {
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fn new(cen: Point3, r: f64) -> Self {
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Sphere {
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center: cen,
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radius: r,
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}
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}
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}
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impl Hittable for Sphere {
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fn hit(&self, r: Ray, t_min: f64, t_max: f64, rec: &mut HitRecord) -> bool {
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let oc = r.origin() - self.center;
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let a = r.direction().length_squared(); // gleiches Ergebnis wie Skalarprodukt
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let b = 2.0 * Vec3::dot(oc, r.direction());
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let c = oc.length_squared() - self.radius * self.radius;
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let discriminant = b * b - 4.0 * a * c;
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if discriminant < 0.0 {
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return false;
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}
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let sqrtd = discriminant.sqrt();
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let root = (-b / 2.0 - sqrtd) / a;
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if root < t_min || t_max < root {
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let root2 = (-b / 2.0 + sqrtd) / a;
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if root2 < t_min || t_max < root {
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return false;
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}
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}
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rec.t = root;
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rec.p = r.at(rec.t);
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rec.normal = (rec.p - self.center) / self.radius;
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return true;
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}
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}
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