rustracer/src/rect.rs

89 lines
2.9 KiB
Rust

use std::sync::Arc;
use crate::hittable::{HitRecord, Hittable};
use crate::{Aabb, Material, Point3, Ray, Vec3};
pub enum Plane {
XY,
XZ,
YZ
}
pub struct Rect2D {
plane: Plane,
a0: f64,
a1: f64,
b0: f64,
b1: f64,
k: f64,
material: Arc<Material>
}
impl Rect2D {
pub fn new(plane: Plane, a0: f64, a1: f64, b0: f64, b1: f64, k: f64, material: Arc<Material>) -> Self {
Self { plane, a0, a1, b0, b1, k, material }
}
}
impl Hittable for Rect2D {
fn hit(&self, ray: &Ray, t_min: f64, t_max: f64) -> Option<HitRecord> {
let t = match &self.plane {
Plane::XY => (self.k - ray.origin().z()) / ray.direction().z(),
Plane::XZ => (self.k - ray.origin().y()) / ray.direction().y(),
Plane::YZ => (self.k - ray.origin().x()) / ray.direction().x(),
};
let (a, b) = match &self.plane {
Plane::XY => (
ray.origin().x() + t * ray.direction().x(),
ray.origin().y() + t * ray.direction().y()),
Plane::XZ => (
ray.origin().x() + t * ray.direction().x(),
ray.origin().z() + t * ray.direction().z()),
Plane::YZ => (
ray.origin().y() + t * ray.direction().y(),
ray.origin().z() + t * ray.direction().z()),
};
if t < t_min || t > t_max {
return None;
}
if a < self.a0 || a > self.a1 || b < self.b0 || b > self.b1 {
return None;
}
let normal = match &self.plane {
Plane::XY => Vec3::new(0.0, 0.0, 1.0),
Plane::XZ => Vec3::new(0.0, 1.0, 0.0),
Plane::YZ => Vec3::new(1.0, 0.0, 0.0),
};
let dot = ray.direction().dot(&normal);
let front_face = dot < 0.0;
let normal = if front_face { normal } else { -normal };
Some(HitRecord {
point: ray.at(t),
normal,
t,
u: (a-self.a0)/(self.a1 -self.a0),
v: (b-self.b0)/(self.b1 -self.b0),
front_face,
material: &self.material
})
}
fn bounding_box(&self, _time0: f64, _time1: f64) -> Option<Aabb> {
// The bounding box must have non-zero width in each dimension, so pad the Z
// dimension a small amount.
match &self.plane {
Plane::XY => Some(Aabb {
minimum: Point3::new(self.a0, self.b0, self.k-0.0001),
maximum: Point3::new(self.a1, self.b1, self.k+0.0001),
}),
Plane::XZ=> Some(Aabb {
minimum: Point3::new(self.a0, self.k-0.0001, self.b0),
maximum: Point3::new(self.a1, self.k+0.0001, self.b1),
}),
Plane::YZ => Some(Aabb {
minimum: Point3::new(self.k-0.0001, self.a0, self.b0),
maximum: Point3::new(self.k+0.0001, self.a1, self.b1),
})
}
}
}