Added presentations from EVI 2017

EVI - 2017/EVI 21/EVIray/phong_brdf.hpp

@@ -0,0 +1,16 @@
+#pragma once
+#ifndef PHONG_BRDF_HPP
+#define PHONG_BRDF_HPP
+
+#include "brdf.hpp"
+
+class PhongBRDF: public BRDF {
+public:
+  PhongBRDF() { }
+  virtual ~PhongBRDF() { }
+  
+  virtual vec3 diffuse(vec3 light_dir, vec3 surface_normal, Ray & incident_ray, vec3 intersection_point, vec3 light_diff_color) const;
+  virtual vec3 specular(vec3 light_dir, vec3 surface_normal, Ray & incident_ray, vec3 intersection_point, vec3 light_spec_color, float shininess) const;
+};
+
+#endif