Bill Thiede
4066bf4b85
Fixed bug in kdtree that this uncovered. Marked Hit and it's dependencies as needing to implement the Debug trait.
85 lines
2.2 KiB
Rust
85 lines
2.2 KiB
Rust
use std;
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use rand::{self, Rng};
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use crate::{
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aabb::AABB,
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hitable::{Hit, HitRecord},
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material::Isotropic,
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ray::Ray,
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texture::Texture,
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vec3::Vec3,
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};
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#[derive(Debug)]
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pub struct ConstantMedium<H, T>
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where
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H: Hit,
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T: Texture,
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{
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density: f32,
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material: Isotropic<T>,
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hitable: H,
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}
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impl<H, T> ConstantMedium<H, T>
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where
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H: Hit,
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T: Texture,
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{
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pub fn new(hitable: H, density: f32, texture: T) -> ConstantMedium<H, T>
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where
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T: Texture,
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{
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ConstantMedium {
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density,
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material: Isotropic::new(texture),
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hitable,
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}
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}
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}
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impl<H, T> Hit for ConstantMedium<H, T>
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where
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H: Hit,
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T: Texture,
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{
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fn hit(&self, r: Ray, t_min: f32, t_max: f32) -> Option<HitRecord> {
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let mut rng = rand::thread_rng();
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if let Some(mut rec1) = self.hitable.hit(r, std::f32::MIN, std::f32::MAX) {
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if let Some(mut rec2) = self.hitable.hit(r, rec1.t + 0.001, std::f32::MAX) {
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if rec1.t < t_min {
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rec1.t = t_min;
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}
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if rec2.t > t_max {
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rec2.t = t_max;
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}
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if rec1.t >= rec2.t {
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return None;
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}
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if rec1.t < 0. {
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rec1.t = 0.;
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}
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let distance_inside_boundary = (rec2.t - rec1.t) * r.direction.length();
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let hit_distance: f32 = -(1. / self.density) * rng.gen::<f32>().ln();
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if hit_distance < distance_inside_boundary {
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let t = rec1.t + hit_distance / r.direction.length();
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let normal = Vec3::new(rng.gen(), rng.gen(), rng.gen()).unit_vector();
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return Some(HitRecord {
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t,
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p: r.point_at_parameter(t),
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normal,
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material: &self.material,
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uv: (0., 0.),
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});
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}
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}
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}
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None
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}
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fn bounding_box(&self, t_min: f32, t_max: f32) -> Option<AABB> {
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self.hitable.bounding_box(t_min, t_max)
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}
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}
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