raytracers/rtiow/renderer/src/rect.rs

// There are many math functions in this file, so we allow single letter variable names.
#![allow(clippy::many_single_char_names)]
use crate::aabb::AABB;
use crate::hitable::Hit;
use crate::hitable::HitRecord;
use crate::material::Material;
use crate::ray::Ray;
use crate::vec3::Vec3;

pub struct XYRect<M>
where
    M: Material,
{
    x0: f32,
    x1: f32,
    y0: f32,
    y1: f32,
    k: f32,
    material: M,
}

impl<M> XYRect<M>
where
    M: Material,
{
    pub fn new(x0: f32, x1: f32, y0: f32, y1: f32, k: f32, material: M) -> XYRect<M> {
        XYRect {
            x0,
            x1,
            y0,
            y1,
            k,
            material,
        }
    }
}

impl<M> Hit for XYRect<M>
where
    M: Material,
{
    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
        let t = (self.k - r.origin.z) / r.direction.z;
        if t < t_min || t > t_max {
            return None;
        }
        let x = r.origin.x + t * r.direction.x;
        let y = r.origin.y + t * r.direction.y;
        if x < self.x0 || x > self.x1 || y < self.y0 || y > self.y1 {
            return None;
        }
        let u = (x - self.x0) / (self.x1 - self.x0);
        let v = (y - self.y0) / (self.y1 - self.y0);
        Some(HitRecord {
            t,
            uv: (u, v),
            p: r.point_at_parameter(t),
            normal: Vec3::new(0., 0., 1.),
            material: &self.material,
        })
    }

    fn bounding_box(&self, _t_min: f32, _t_max: f32) -> Option<AABB> {
        Some(AABB::new(
            Vec3::new(self.x0, self.y0, self.k - 0.0001),
            Vec3::new(self.x1, self.y1, self.k + 0.0001),
        ))
    }
}

pub struct XZRect<M>
where
    M: Material,
{
    x0: f32,
    x1: f32,
    z0: f32,
    z1: f32,
    k: f32,
    material: M,
}

impl<M> XZRect<M>
where
    M: Material,
{
    pub fn new(x0: f32, x1: f32, z0: f32, z1: f32, k: f32, material: M) -> XZRect<M> {
        XZRect {
            x0,
            x1,
            z0,
            z1,
            k,
            material,
        }
    }
}

impl<M> Hit for XZRect<M>
where
    M: Material,
{
    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
        let t = (self.k - r.origin.y) / r.direction.y;
        if t < t_min || t > t_max {
            return None;
        }
        let x = r.origin.x + t * r.direction.x;
        let z = r.origin.z + t * r.direction.z;
        if x < self.x0 || x > self.x1 || z < self.z0 || z > self.z1 {
            return None;
        }
        let u = (x - self.x0) / (self.x1 - self.x0);
        let v = (z - self.z0) / (self.z1 - self.z0);
        Some(HitRecord {
            t,
            uv: (u, v),
            p: r.point_at_parameter(t),
            normal: Vec3::new(0., 1., 0.),
            material: &self.material,
        })
    }

    fn bounding_box(&self, _t_min: f32, _t_max: f32) -> Option<AABB> {
        Some(AABB::new(
            Vec3::new(self.x0, self.k - 0.0001, self.z0),
            Vec3::new(self.x1, self.k + 0.0001, self.z1),
        ))
    }
}

pub struct YZRect<M>
where
    M: Material,
{
    y0: f32,
    y1: f32,
    k: f32,
    z0: f32,
    z1: f32,
    material: M,
}

impl<M> YZRect<M>
where
    M: Material,
{
    pub fn new(y0: f32, y1: f32, z0: f32, z1: f32, k: f32, material: M) -> YZRect<M> {
        YZRect {
            y0,
            y1,
            z0,
            z1,
            k,
            material,
        }
    }
}

impl<M> Hit for YZRect<M>
where
    M: Material,
{
    fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
        let t = (self.k - r.origin.x) / r.direction.x;
        if t < t_min || t > t_max {
            return None;
        }
        let y = r.origin.y + t * r.direction.y;
        let z = r.origin.z + t * r.direction.z;
        if y < self.y0 || y > self.y1 || z < self.z0 || z > self.z1 {
            return None;
        }
        let u = (y - self.y0) / (self.y1 - self.y0);
        let v = (z - self.z0) / (self.z1 - self.z0);
        Some(HitRecord {
            t,
            uv: (u, v),
            p: r.point_at_parameter(t),
            normal: Vec3::new(1., 0., 0.),
            material: &self.material,
        })
    }

    fn bounding_box(&self, _t_min: f32, _t_max: f32) -> Option<AABB> {
        Some(AABB::new(
            Vec3::new(self.k - 0.0001, self.y0, self.z0),
            Vec3::new(self.k + 0.0001, self.y1, self.z1),
        ))
    }
}