From e397ee9ad9187b102bdcf7b1b9913b6f6b499287 Mon Sep 17 00:00:00 2001
From: Jean-Michel Gorius <jean-michel.gorius@protonmail.com>
Date: Fri, 11 Nov 2022 09:48:49 +0100
Subject: [PATCH] Use true Lambertian diffusion

---
 main.c | 2 +-
 vec3.c | 4 ++++
 vec3.h | 1 +
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/main.c b/main.c
index 2d972ab..d78b555 100644
--- a/main.c
+++ b/main.c
@@ -18,7 +18,7 @@ Color ray_color(Ray r, Hittable world, int depth) {
   HitRecord record;
   if (hittable_hit(&world, r, 0.001, DBL_MAX, &record)) {
     Point3 target = point3_add(
-        record.p, vec3_add(record.normal, vec3_random_in_unit_sphere()));
+        record.p, vec3_add(record.normal, vec3_random_unit_vector()));
     return color_mul(0.5,
                      ray_color((Ray){record.p, point3_sub(target, record.p)},
                                world, depth - 1));
diff --git a/vec3.c b/vec3.c
index 3d148d8..4dda89a 100644
--- a/vec3.c
+++ b/vec3.c
@@ -59,3 +59,7 @@ Vec3 vec3_random_in_unit_sphere(void) {
     return result;
   }
 }
+
+Vec3 vec3_random_unit_vector(void) {
+  return vec3_normalize(vec3_random_in_unit_sphere());
+}
diff --git a/vec3.h b/vec3.h
index d4400c9..1bbd53b 100644
--- a/vec3.h
+++ b/vec3.h
@@ -22,5 +22,6 @@ Vec3 vec3_cross(Vec3 v1, Vec3 v2);
 Vec3 vec3_random(void);
 Vec3 vec3_random_in_range(double min, double max);
 Vec3 vec3_random_in_unit_sphere(void);
+Vec3 vec3_random_unit_vector(void);
 
 #endif /* INCLUDED_VEC3_H */