Defocus blur & randow scene generation

1 files changed, 20 insertions, 10 deletions

diff --git a/src/camera.cpp b/src/camera.cpp
index 520cc1e..c7866d6 100644
--- a/src/camera.cpp
+++ b/src/camera.cpp
@@ -2,27 +2,37 @@
 
 #include "rt.hpp"
 
-camera::camera(point3 position, point3 target, double v_fov, double aspect_ratio)
-    : position(position) {
+camera::camera(
+        point3 position,
+        point3 target,
+        double v_fov,
+        double aspect_ratio,
+        double aperture,
+        double focus_dist
+    ) : position(position), lens_radius(aperture / 2.0) {
 
-    auto forward = (position - target).unit();
-    auto right = vec3{ 0.0, 1.0, 0.0 }.cross(forward).unit();
-    auto up = forward.cross(right).unit();
+    forward = (position - target).unit();
+    right = vec3{ 0.0, 1.0, 0.0 }.cross(forward).unit();
+    up = forward.cross(right).unit();
 
     auto h = tan(deg_to_rad(v_fov) / 2.0);
     auto viewport_height = 2.0 * h;
     auto viewport_width = viewport_height * aspect_ratio;
 
-    horizontal = viewport_width * right;
-    vertical = viewport_height * up;
+    horizontal  = focus_dist * viewport_width * right;
+    vertical    = focus_dist * viewport_height * up;
 
-    bottom_left_pixel = position - horizontal / 2.0 - vertical / 2.0 - forward;
+    bottom_left_pixel = position - horizontal / 2.0 - vertical / 2.0 - forward * focus_dist;
 }
 
 ray camera::get_ray(double u, double v) const {
+    vec3 rd = lens_radius * random_in_unit_disk();
+    vec3 offset = rd.x * right + rd.y * up;
+
     point3 viewport_pixel = bottom_left_pixel + u * horizontal + v * vertical;
+
     return ray {
-        position,
-        viewport_pixel - position
+        position + offset,
+        viewport_pixel - position - offset
     };
 }