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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 {
Self::new(
ASPECT_RATIO,
IMG_WIDTH,
VFOV,
LOOK_FROM,
LOOK_AT,
VUP,
SAMPLES_PER_PIXEL,
FOCUS_DIST,
DEFOCUS_ANGLE,
MAX_DEPTH
)
}
}
impl Camera {
pub fn new(
aspect_ratio: f32,
image_width: usize,
vfov: f32,
look_from: Point3,
look_at: Point3,
vup: Vec3,
samples_per_pixel: usize,
focus_dist: f32,
defocus_angle: f32,
max_depth: usize,
) -> Self {
let mut new_camera = Self {
aspect_ratio,
image_width,
image_height: 1,
center: Point3::new(0.0, 0.0, 0.0),
pixel_upper_left: Point3::new(0.0, 0.0, 0.0),
delta_pixel_u: Vec3::new(0.0, 0.0, 0.0),
delta_pixel_v: Vec3::new(0.0, 0.0, 0.0),
samples_per_pixel,
pixel_samples_scale: 1.0,
max_depth,
vfov,
look_from,
look_at,
vup,
defocus_angle,
focus_dist,
defocus_disk_u: Vec3::new(0.0, 0.0, 0.0),
defocus_disk_v: Vec3::new(0.0, 0.0, 0.0),
};
new_camera.compute_dependent_fields();
new_camera
}
fn compute_dependent_fields(&mut self) {
self.image_height = get_image_height(self.image_width, self.aspect_ratio);
self.center = self.look_from;
self.pixel_samples_scale = 1.0 / self.samples_per_pixel as f32;
let theta = deg2rad(self.vfov);
let h = (theta / 2.0).tan();
let w = self.look_from.sub(&self.look_at).unit();
let u = self.vup.cross_prod(&w).unit();
let v = w.cross_prod(&u).unit();
let viewport_height = 2.0 * h * self.focus_dist;
let viewport_width = viewport_height * (self.image_width as f32 / self.image_height as f32);
let viewport_u = u.scalar_mul(viewport_width);
let viewport_v = v.scalar_mul(-1.0).scalar_mul(viewport_height);
self.delta_pixel_u = viewport_u.scalar_mul(1.0 / self.image_width as f32);
self.delta_pixel_v = viewport_v.scalar_mul(1.0 / self.image_height as f32);
let viewport_upper_left = self.center
.sub(&w.scalar_mul(self.focus_dist))
.sub(&viewport_u.scalar_mul(0.5))
.sub(&viewport_v.scalar_mul(0.5));
self.pixel_upper_left = viewport_upper_left.add(
&self.delta_pixel_u.add(&self.delta_pixel_v).scalar_mul(0.5)
);
let defocus_radius = self.focus_dist * deg2rad(self.defocus_angle / 2.0).tan();
self.defocus_disk_u = u.scalar_mul(defocus_radius);
self.defocus_disk_v = v.scalar_mul(defocus_radius);
}
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);
})
})
}
}
|
