use crate::types::{Ray, Vec3};

pub struct Camera {
    pub origin: Vec3,
    pub horizontal: Vec3,
    pub vertical: Vec3,
    pub lower_left_corner: Vec3,
}

impl Camera {
    pub const fn new(
        origin: Vec3,
        horizontal: Vec3,
        vertical: Vec3,
        lower_left_corner: Vec3,
    ) -> Self {
        Self {
            origin,
            horizontal,
            vertical,
            lower_left_corner,
        }
    }

    pub fn get_ray(&self, u: f32, v: f32) -> Ray {
        Ray::new(
            self.origin,
            self.lower_left_corner + self.horizontal * u + self.vertical * v - self.origin,
        )
    }
}

impl std::default::Default for Camera {
    fn default() -> Self {
        Camera {
            origin: Vec3::new(0.0, 0.0, 0.0),
            // Because canvas is in 2:1 ratio
            horizontal: Vec3::new(4.0, 0.0, 0.0),
            vertical: Vec3::new(0.0, 2.0, 0.0),
            lower_left_corner: Vec3::new(-2.0, -1.0, -1.0),
        }
    }
}