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use crate::calculus::calculus::{deg2rad, sample_square, Point3, Ray, Vec3};
use crate::common::{get_image_height, Color, DisplayBuffer, Pixel, ASPECT_RATIO, DEFOCUS_ANGLE, FOCUS_DIST, IMG_WIDTH, LOOK_AT, LOOK_FROM, MAX_DEPTH, SAMPLES_PER_PIXEL, VFOV, VUP};
use crate::interval::Interval;
use crate::object::{HitRecord, Hittable, HittableList};
pub struct Camera {
pub aspect_ratio: f32,
pub image_width: usize,
pub samples_per_pixel: usize,
pub vfov: f32,
pub look_from: Point3,
pub look_at: Point3,
pub vup: Vec3,
image_height: usize,
center: Point3,
pixel_upper_left: Point3,
delta_pixel_u: Vec3,
delta_pixel_v: Vec3,
pixel_samples_scale: f32,
max_depth: usize,
pub defocus_angle: f32,
pub focus_dist: f32,
pub defocus_disk_u: Vec3,
pub defocus_disk_v: Vec3,
}
impl Default for Camera {
fn default() -> Self {
let aspect_ratio = ASPECT_RATIO;
let image_width = IMG_WIDTH;
let image_height = get_image_height(image_width, aspect_ratio);
let vfov = VFOV;
let look_from = LOOK_FROM;
let look_at = LOOK_AT;
let vup = VUP;
let center = look_from;
// let focal_length = look_from.sub(&look_at).mag();
let theta = deg2rad(vfov);
let h = (theta / 2.0).tan();
let w = look_from.sub(&look_at).unit();
let u = vup.cross_prod(&w).unit();
let v = w.cross_prod(&u).unit();
let samples_per_pixel = SAMPLES_PER_PIXEL;
let pixel_samples_scale = 1.0 / samples_per_pixel as f32;
let focus_dist = FOCUS_DIST;
let defocus_angle = DEFOCUS_ANGLE;
let viewport_height = 2.0 * h * focus_dist;
let viewport_width = viewport_height * (image_width as f32 / image_height as f32);
let viewport_u = u.scalar_mul(viewport_width);
let viewport_v = v.scalar_mul(-1.0).scalar_mul(viewport_height);
let delta_pixel_u = viewport_u.scalar_mul(1.0 / image_width as f32);
let delta_pixel_v = viewport_v.scalar_mul(1.0 / image_height as f32);
let viewport_upper_left = center
.sub(&w.scalar_mul(focus_dist))
.sub(&viewport_u.scalar_mul(0.5))
.sub(&viewport_v.scalar_mul(0.5));
let pixel_upper_left = viewport_upper_left.add(
&delta_pixel_u.add(&delta_pixel_v).scalar_mul(0.5)
);
let defocus_radius = focus_dist * deg2rad(defocus_angle / 2.0).tan();
let defocus_disk_u = u.scalar_mul(defocus_radius);
let defocus_disk_v = v.scalar_mul(defocus_radius);
let max_depth = MAX_DEPTH;
Self {
aspect_ratio,
image_width,
image_height,
center,
pixel_upper_left,
delta_pixel_u,
delta_pixel_v,
samples_per_pixel,
pixel_samples_scale,
max_depth,
vfov,
look_from,
look_at,
vup,
defocus_angle,
focus_dist,
defocus_disk_u,
defocus_disk_v,
}
}
}
impl Camera {
fn get_ray(&self, i: usize, j: usize) -> Ray {
let offset = sample_square();
let pixel_sample = self.pixel_upper_left
.add(&self.delta_pixel_u.scalar_mul(i as f32 + offset.x))
.add(&self.delta_pixel_v.scalar_mul(j as f32 + offset.y));
let ray_origin = if self.defocus_angle <= 0.0 { self.center } else { self.defocus_disk_sample() };
let ray_direction = pixel_sample.sub(&ray_origin);
Ray {
origin: ray_origin,
direction: ray_direction,
}
}
fn defocus_disk_sample(&self) -> Point3 {
let p = Vec3::random_in_unit_disk();
self.center
.add(&self.defocus_disk_u.scalar_mul(p.x))
.add(&self.defocus_disk_v.scalar_mul(p.y))
}
fn ray_color(&self, ray: &Ray, world: &HittableList, depth: usize) -> Color {
if depth <= 0 {
return Color::new(0.0, 0.0, 0.0);
}
let mut rec = HitRecord::default();
let ray_t = Interval::new(0.001, f32::INFINITY);
if world.hit(ray, ray_t, &mut rec) {
let mut scattered: Ray = Ray {
origin: Vec3::random_unit(),
direction: Vec3::random_unit(),
};
let mut attenuation: Color = Color::new(0.0, 0.0, 0.0);
if rec.material.scatter(ray, &rec, &mut attenuation, &mut scattered) {
return attenuation.elem_prod(&self.ray_color(&mut scattered, &world, depth - 1));
}
return Color::new(0.0, 0.0, 0.0);
}
let unit_direction = ray.direction.unit();
let a = 0.5 * (unit_direction.y + 1.0);
let color1 = Color::new(1.0, 1.0, 1.0).mul_scalar(1.0 - a);
let color2 = Color::new(0.5, 0.7, 1.0).mul_scalar(a);
color1.add(&color2)
}
pub fn render(&self, display_buffer: &mut DisplayBuffer, world: &HittableList) {
(0..self.image_height).for_each(|j| {
(0..self.image_width).for_each(|i| {
println!("Processing line {} col {}", j, i);
let mut pixel_color = Color::new(0.0, 0.0, 0.0);
(0..self.samples_per_pixel).for_each(|_| {
let r = self.get_ray(i, j);
let ray_color = self.ray_color(&r, world, self.max_depth);
pixel_color = pixel_color.add(&ray_color);
});
pixel_color = pixel_color.mul_scalar(self.pixel_samples_scale);
display_buffer[j][i] = Pixel::from_color(&pixel_color);
})
})
}
}
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