Files
rust-raytracer/src/camera.rs
2023-11-16 01:30:35 -05:00

87 lines
2.6 KiB
Rust

use crate::ray::Ray;
use crate::{EPSILON, INFINITY};
use nalgebra as nm;
use nalgebra::Matrix4;
use nalgebra::Point3;
use nalgebra::Vector3;
#[rustfmt::skip]
pub const OPENGL_TO_WGPU_MATRIX: Matrix4<f32> = Matrix4::new(
1.0, 0.0, 0.0, 0.0,
0.0, 1.0, 0.0, 0.0,
0.0, 0.0, 0.5, 0.5,
0.0, 0.0, 0.0, 1.0,
);
pub struct Camera {
eye: Point3<f32>,
target: Point3<f32>,
up: Vector3<f32>,
fovy: f32,
aspect: f32,
znear: f32,
zfar: f32,
matrix: Matrix4<f32>,
inverse: Matrix4<f32>,
}
impl Camera {
pub fn new(
eye: Point3<f32>,
target: Point3<f32>,
up: Vector3<f32>,
fovy: f32,
aspect: f32,
) -> Self {
let znear = EPSILON;
let zfar = INFINITY;
let matrix = self.build_view_projection_matrix(eye, target, up, aspect, fovy, znear, zfar);
let inverse = self.build_inverse_view_projection_matrix(eye, target, up, aspect, fovy, znear, zfar);
Camera {
eye,
target,
up,
fovy,
aspect,
znear,
zfar,
}
}
pub fn build_view_projection_matrix(eye: Point3<f32>, target: Point3<f32>, up: Vector3<f32>, aspect: f32, fovy: f32, znear: f32, zfar: f32) -> Matrix4<f32> {
let view = Matrix4::look_at_lh(eye, target, up);
let proj = Matrix4::new_perspective(aspect, fovy,znear, zfar);
proj * view
}
pub fn build_inverse_view_projection_matrix(eye: Point3<f32>, target: Point3<f32>, up: Vector3<f32>, aspect: f32, fovy: f32, znear: f32, zfar: f32) -> Matrix4<f32> {
let view_proj = self.build_view_projection_matrix(eye, target, up, aspect, fovy, znear, zfar);
view_proj.try_inverse().expect("Cannot invert!")
}
pub fn cast_rays(&self, width: u32, height: u32) -> Vec<Ray> {
let inverse_matrix = self.build_inverse_view_projection_matrix();
let dx = 2.0 / width as f32;
let dy = 2.0 / height as f32;
let mut rays = Vec::with_capacity(width as usize * height as usize);
for i in 0..width {
for j in 0..height {
let x = -1.0 + i as f32 * dx;
let y = 1.0 - j as f32 * dy;
let a = inverse_matrix.transform_point(&Point3::new(x, y, -1.0));
let b = inverse_matrix.transform_vector(&Vector3::new(0.0, 0.0, 1.0));
let ray = Ray { a, b };
rays.push(ray);
}
}
rays
}
pub fn cast_ray(&self, width: u32, height: u32, x: u32, y: u32) -> Ray {
let dx = 2.0 / width as f32;
let dy = 2.0 / height as f32;
}
}