Separated BRDF from light source.

phong_brdf.cpp

@@ -0,0 +1,19 @@
+#include "glm/glm.hpp"
+
+#include "phong_brdf.hpp"
+
+using glm::reflect;
+using glm::pow;
+using glm::max;
+using glm::dot;
+
+vec3 PhongBRDF::diffuse(vec3 light_dir, vec3 surface_normal, Ray & incident_ray, vec3 light_diff_color) const {
+  float n_dot_l = max(dot(surface_normal, light_dir), 0.0f);
+  return light_diff_color * n_dot_l;
+}
+
+vec3 PhongBRDF::specular(vec3 light_dir, vec3 surface_normal, Ray & incident_ray, vec3 light_spec_color, float shininess) const {
+  vec3 ref = reflect(light_dir, surface_normal);
+  float r_dot_l = pow(max(dot(ref, incident_ray.m_direction), 0.0f), shininess);
+  return light_spec_color * r_dot_l;
+}