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use crate::math::*;
#[derive(Clone, Copy)]
pub struct Camera {
pub eye: P3,
pub look_at: P3,
pub up: Vec3,
pub aspect_ratio: f32,
pub fov: f32,
pub near: f32,
pub far: f32,
pub perspective: Mat4,
}
impl Camera {
pub fn new(eye: P3, look_at: P3, aspect_ratio: f32) -> Self {
let mut camera = Self {
eye,
look_at,
up: Vec3::new(0., 1., 0.),
aspect_ratio,
fov: std::f32::consts::FRAC_PI_2,
near: 0.1,
far: 100.,
perspective: Mat4::identity(),
};
camera.perspective = camera.perspective_transform();
camera
}
pub fn from_tiles(tile_width: u32) -> Self {
let screen_width = 1920.;
let screen_height = 1080.;
let tiles_per_x = screen_width / tile_width as f32;
let r = screen_height / screen_width;
let n = tiles_per_x as f32 * 0.5;
let d = n * r / std::f32::consts::FRAC_PI_4.tan();
let h = n * r;
let camera_eye = P3::new(n, h, d);
let camera_target = P3::new(n, h, 0.);
Camera::new(camera_eye, camera_target, screen_width / screen_height)
}
pub fn perspective_transform(&self) -> Mat4 {
cgmath::perspective(
cgmath::Rad(self.fov),
self.aspect_ratio,
self.near,
self.far,
)
}
pub fn look_at_transform(&self) -> Mat4 {
Mat4::look_at(self.eye, self.look_at, self.up)
}
pub fn build_transform(&self) -> Mat4 {
self.perspective * self.look_at_transform()
}
}