1 files changed, 22 insertions, 18 deletions

diff --git a/racer-tracer/src/camera.rs b/racer-tracer/src/camera.rs
index 31c2391..e6396e8 100644
--- a/racer-tracer/src/camera.rs
+++ b/racer-tracer/src/camera.rs
@@ -1,13 +1,12 @@
 use crate::image::Image;
 use crate::ray::Ray;
-use crate::util::degrees_to_radians;
+use crate::util::{degrees_to_radians, random_in_unit_disk};
 use crate::vec3::Vec3;
 
 #[derive(Clone)]
 pub struct Camera {
     pub viewport_height: f64,
     pub viewport_width: f64,
-    pub focal_length: f64,
     pub origin: Vec3,
     pub horizontal: Vec3,
     pub vertical: Vec3,
@@ -15,6 +14,8 @@ pub struct Camera {
     pub forward: Vec3,
     pub right: Vec3,
     pub up: Vec3,
+    pub lens_radius: f64,
+    pub focus_distance: f64,
 }
 
 impl Camera {
@@ -24,7 +25,8 @@ impl Camera {
         up: Vec3,
         vfov: f64,
         image: &Image,
-        focal_length: f64,
+        aperture: f64,
+        focus_distance: f64,
     ) -> Camera {
         let h = (degrees_to_radians(vfov) / 2.0).tan();
         let viewport_height = 2.0 * h;
@@ -34,45 +36,47 @@ impl Camera {
         let right = up.cross(&forward).unit_vector();
         let up = forward.cross(&right);
 
-        let horizontal = viewport_width * right;
-        let vertical = viewport_height * up;
-
+        let horizontal = focus_distance * viewport_width * right;
+        let vertical = focus_distance * viewport_height * up;
         Camera {
             viewport_height,
             viewport_width,
-            focal_length,
             origin: look_from,
             horizontal,
             vertical,
-            upper_left_corner: look_from + vertical / 2.0 - horizontal / 2.0 - forward,
+            upper_left_corner: look_from + vertical / 2.0
+                - horizontal / 2.0
+                - focus_distance * forward,
             forward,
             right,
             up,
+            lens_radius: aperture * 0.5,
+            focus_distance,
         }
     }
 
     pub fn get_ray(&self, u: f64, v: f64) -> Ray {
+        let ray_direction = self.lens_radius * random_in_unit_disk();
+        let offset = self.right * ray_direction.x() + self.up * ray_direction.y();
         Ray::new(
-            self.origin,
-            self.upper_left_corner + u * self.horizontal - v * self.vertical - self.origin,
+            self.origin + offset,
+            self.upper_left_corner + u * self.horizontal - v * self.vertical - self.origin - offset,
         )
     }
 
-    // TODO: Add support for rotation
-
-    // TODO: Use forward facing vector
     pub fn go_forward(&mut self, go: f64) {
         self.origin += self.forward * go;
 
-        self.upper_left_corner =
-            self.origin + self.vertical / 2.0 - self.horizontal / 2.0 - self.forward;
+        self.upper_left_corner = self.origin + self.vertical / 2.0
+            - self.horizontal / 2.0
+            - self.focus_distance * self.forward;
     }
 
-    // TODO: Use right facing vector
     pub fn go_right(&mut self, go: f64) {
         self.origin += self.right * go;
 
-        self.upper_left_corner =
-            self.origin + self.vertical / 2.0 - self.horizontal / 2.0 - self.forward;
+        self.upper_left_corner = self.origin + self.vertical / 2.0
+            - self.horizontal / 2.0
+            - self.focus_distance * self.forward;
     }
 }