1 files changed, 58 insertions, 0 deletions
diff --git a/src/camera.rs b/src/camera.rs
new file mode 100644
index 0000000..55bf387
--- /dev/null
+++ b/src/camera.rs
@@ -0,0 +1,58 @@
+use crate::ray::Ray;
+use crate::vec3::{Point3, Vec3};
+use crate::util::degrees_to_radians;
+
+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::<f64>(),
+        }
+    }
+}