use crate::ray::Ray; use crate::util::degrees_to_radians; use crate::vec3::{Point3, Vec3}; pub struct Camera { origin: Point3, lower_left_corner: Point3, horizontal: Vec3, vertical: Vec3, w: Vec3, u: Vec3, v: Vec3, lens_radius: f64, time_start: f64, time_end: f64, } impl Camera { pub fn new( lookfrom: Point3, lookat: Point3, vup: Vec3, vfov: f64, aspect_ratio: f64, aperture: f64, focus_dist: f64, time_start: f64, time_end: f64, ) -> Camera { let theta = degrees_to_radians(vfov); let h = (theta / 2.0).tan(); let viewport_height = 2.0 * h; let viewport_width = aspect_ratio * viewport_height; let w = (&lookfrom - &lookat).unit_vector(); let u = vup.cross(&w).unit_vector(); let v = w.cross(&u); let origin = lookfrom; let horizontal = focus_dist * viewport_width * &u; let vertical = focus_dist * viewport_height * &v; Camera { lower_left_corner: &origin - &horizontal / 2.0 - &vertical / 2.0 - focus_dist * &w, origin, horizontal, vertical, w, u, v, lens_radius: aperture / 2.0, time_start, time_end, } } pub fn get_ray(&self, s: f64, t: f64) -> Ray { let rd = self.lens_radius * Vec3::random_in_unit_disk(); let offset = &self.u * rd.x + &self.v * rd.y; Ray { origin: &self.origin + &offset, direction: &self.lower_left_corner + s * &self.horizontal + t * &self.vertical - &self.origin - &offset, time: self.time_start + (self.time_end - self.time_start) * rand::random::(), } } }