Separated BRDF from light source.

Makefile

@@ -1,6 +1,6 @@
 CXX = g++
 TARGET = ray
-OBJECTS = main.o disk.o plane.o sphere.o directional_light.o point_light.o tracer.o path_tracer.o whitted_tracer.o
+OBJECTS = main.o disk.o plane.o sphere.o directional_light.o point_light.o tracer.o path_tracer.o whitted_tracer.o phong_brdf.o
 DEPENDS = $(OBJECTS:.o=.d)
 CXXFLAGS = -ansi -pedantic -Wall -DGLM_FORCE_RADIANS -fopenmp
 LDLIBS = -lfreeimage

brdf.hpp

@@ -0,0 +1,20 @@
+#pragma once
+#ifndef BRDF_HPP
+#define BRDF_HPP
+
+#include <glm/vec3.hpp>
+
+#include "ray.hpp"
+#include "material.hpp"
+
+using glm::vec3;
+
+class BRDF {
+public:
+  virtual ~BRDF() { }
+  
+  virtual vec3 diffuse(vec3 light_dir, vec3 surface_normal, Ray & incident_ray, vec3 light_diff_color) const = 0;
+  virtual vec3 specular(vec3 light_dir, vec3 surface_normal, Ray & incident_ray, vec3 light_spec_color, float shininess) const = 0;
+};
+
+#endif

directional_light.cpp

@@ -20,23 +20,10 @@ inline float DirectionalLight::distance(vec3 point) {
   return numeric_limits<float>::max();
 }
 
-vec3 DirectionalLight::diffuse(vec3 normal, Ray & r, float t, Material & m) const {
-  float n_dot_l;
-  vec3 color;
-
-  n_dot_l = max(dot(normal, m_position), 0.0f);
-  color += m_diffuse * n_dot_l;
-
-  return color;
+vec3 DirectionalLight::diffuse(vec3 normal, Ray & r, vec3 i_pos, Material & m) const {
+  return m_brdf->diffuse(m_position, normal, r, m_diffuse);
 }
 
-vec3 DirectionalLight::specular(vec3 normal, Ray & r, float t, Material & m) const {
-  float r_dot_l;
-  vec3 color, ref;
-
-  ref = reflect(m_position, normal);
-  r_dot_l = pow(max(dot(ref, r.m_direction), 0.0f), m.m_shininess);
-  color += m.m_specular * m_specular * r_dot_l;
-
-  return color;
+vec3 DirectionalLight::specular(vec3 normal, Ray & r, vec3 i_pos, Material & m) const {
+  return m.m_specular * m_brdf->specular(m_position, normal, r, m_specular, m.m_shininess);
 }

directional_light.hpp

@@ -6,22 +6,14 @@
 
 class DirectionalLight: public Light {
 public:
-  DirectionalLight() {
-    m_position = vec3(0.0f);
-    m_diffuse = vec3(1.0f);
-    m_specular = vec3(1.0f);
-  }
+  DirectionalLight(): Light() { }
 
-  DirectionalLight(vec3 _p, vec3 _d, vec3 _s) {
-    m_position = _p;
-    m_diffuse = _d;
-    m_specular = _s;
-  }
+  DirectionalLight(BRDF * _brdf, vec3 _p, vec3 _d, vec3 _s): Light(_brdf, _p, _d, _s) { }
 
   virtual vec3 direction(vec3 point);
   virtual float distance(vec3 point);
-  virtual vec3 diffuse(vec3 normal, Ray & r, float t, Material & m) const;
-  virtual vec3 specular(vec3 normal, Ray & r, float t, Material & m) const;
+  virtual vec3 diffuse(vec3 normal, Ray & r, vec3 i_pos, Material & m) const;
+  virtual vec3 specular(vec3 normal, Ray & r, vec3 i_pos, Material & m) const;
 };
 
 #endif

light.hpp

@@ -4,6 +4,8 @@
 
 #include <glm/vec3.hpp>
 
+#include "brdf.hpp"
+#include "phong_brdf.hpp"
 #include "ray.hpp"
 #include "material.hpp"
 
@@ -11,16 +13,23 @@ using glm::vec3;
 
 class Light {
 public:
+  BRDF * m_brdf;
   vec3 m_position;
   vec3 m_diffuse;
   vec3 m_specular;
 
-  virtual ~Light() { }
+  Light(): m_brdf(static_cast<BRDF *>(new PhongBRDF())), m_position(vec3(0.0f)), m_diffuse(vec3(1.0f)), m_specular(vec3(1.0f)) { }
+
+  Light(BRDF * _brdf, vec3 _p, vec3 _d, vec3 _s): m_brdf(_brdf), m_position(_p), m_diffuse(_d), m_specular(_s) { }
+  
+  virtual ~Light() {
+    delete m_brdf;
+  }
 
   virtual vec3 direction(vec3 point) = 0;
   virtual float distance(vec3 point) = 0;
-  virtual vec3 diffuse(vec3 normal, Ray & r, float t, Material & m) const = 0;
-  virtual vec3 specular(vec3 normal, Ray & r, float t, Material & m) const = 0;
+  virtual vec3 diffuse(vec3 normal, Ray & r, vec3 i_pos, Material & m) const = 0;
+  virtual vec3 specular(vec3 normal, Ray & r, vec3 i_pos, Material & m) const = 0;
 };
 
 #endif

main.cpp

@@ -20,6 +20,8 @@
 #include "point_light.hpp"
 #include "tracer.hpp"
 #include "path_tracer.hpp"
+#include "brdf.hpp"
+#include "phong_brdf.hpp"
 
 using namespace std;
 using namespace glm;

path_tracer.cpp

@@ -53,8 +53,8 @@ vec3 PathTracer::trace_ray(Ray & r, vector<Figure *> & v_figures, vector<Light *
 	}
 
 	// Evaluate the shading model accounting for visibility.
-	dir_diff_color += vis ? v_lights[l]->diffuse(n, r, t, _f->m_mat) : vec3(0.0f);
-	dir_spec_color += vis ? v_lights[l]->specular(n, r, t, _f->m_mat) : vec3(0.0f);
+	dir_diff_color += vis ? v_lights[l]->diffuse(n, r, i_pos, _f->m_mat) : vec3(0.0f);
+	dir_spec_color += vis ? v_lights[l]->specular(n, r, i_pos, _f->m_mat) : vec3(0.0f);
       }
 
       // Calculate indirect lighting contribution.

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;
+}

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 light_diff_color) const;
+  virtual vec3 specular(vec3 light_dir, vec3 surface_normal, Ray & incident_ray, vec3 light_spec_color, float shininess) const;
+};
+
+#endif

point_light.cpp

@@ -19,35 +19,26 @@ inline float PointLight::distance(vec3 point) {
   return length(m_position - point);
 }
 
-vec3 PointLight::diffuse(vec3 normal, Ray & r, float t, Material & m) const {
-  float d, att, n_dot_l;
-  vec3 color, i_pos, l_dir, ref;
+vec3 PointLight::diffuse(vec3 normal, Ray & r, vec3 i_pos, Material & m) const {
+  float d, att;
+  vec3 l_dir, ref;
 
-  i_pos = r.m_origin + t * r.m_direction;
   l_dir = m_position - i_pos;
   d = length(l_dir);
   l_dir = normalize(l_dir);
   att = 1.0f / (m_const_att + (m_lin_att * d) + (m_quad_att * (d * d)));
 
-  n_dot_l = max(dot(normal, l_dir), 0.0f);
-  color += att * m_diffuse * n_dot_l;
-
-  return color;
+  return att * m_brdf->diffuse(l_dir, normal, r, m_diffuse);
 }
 
-vec3 PointLight::specular(vec3 normal, Ray & r, float t, Material & m) const {
-  float d, att, r_dot_l;
-  vec3 color, i_pos, l_dir, ref;
+vec3 PointLight::specular(vec3 normal, Ray & r, vec3 i_pos, Material & m) const {
+  float d, att;
+  vec3 l_dir, ref;
 
-  i_pos = r.m_origin + t * r.m_direction;
   l_dir = m_position - i_pos;
   d = length(l_dir);
   l_dir = normalize(l_dir);
   att = 1.0f / (m_const_att + (m_lin_att * d) + (m_quad_att * (d * d)));
 
-  ref = reflect(l_dir, normal);
-  r_dot_l = pow(max(dot(ref, r.m_direction), 0.0f), m.m_shininess);
-  color += att * m.m_specular * m_specular * r_dot_l; 
-
-  return color;
+  return att * m.m_specular * m_brdf->specular(l_dir, normal, r, m_specular, m.m_shininess);
 }

point_light.hpp

@@ -10,22 +10,14 @@ public:
   float m_lin_att;
   float m_quad_att;
 
-  PointLight(): m_const_att(1.0f), m_lin_att(0.0f), m_quad_att(0.0f) {
-    m_position = vec3(0.0f);
-    m_diffuse = vec3(1.0f);
-    m_specular = vec3(1.0f);
-  }
+  PointLight(): Light(), m_const_att(1.0f), m_lin_att(0.0f), m_quad_att(0.0f) { }
 
-  PointLight(vec3 _p, vec3 _d, vec3 _s, float _c, float _l, float _q): m_const_att(_c), m_lin_att(_l), m_quad_att(_q) {
-    m_position = _p;
-    m_diffuse = _d;
-    m_specular = _s;
-  }
+  PointLight(BRDF * _brdf, vec3 _p, vec3 _d, vec3 _s, float _c, float _l, float _q): Light(_brdf, _p, _d, _s), m_const_att(_c), m_lin_att(_l), m_quad_att(_q) { }
 
   virtual vec3 direction(vec3 point);
   virtual float distance(vec3 point);
-  virtual vec3 diffuse(vec3 normal, Ray & r, float t, Material & m) const;
-  virtual vec3 specular(vec3 normal, Ray & r, float t, Material & m) const;
+  virtual vec3 diffuse(vec3 normal, Ray & r, vec3 i_pos, Material & m) const;
+  virtual vec3 specular(vec3 normal, Ray & r, vec3 i_pos, Material & m) const;
 };
 
 #endif

whitted_tracer.cpp

@@ -51,8 +51,8 @@ vec3 WhittedTracer::trace_ray(Ray & r, vector<Figure *> & v_figures, vector<Ligh
 	}
 
 	// Evaluate the shading model accounting for visibility.
-	dir_diff_color += vis ? v_lights[l]->diffuse(n, r, t, _f->m_mat) : vec3(0.0f);
-	dir_spec_color += vis ? v_lights[l]->specular(n, r, t, _f->m_mat) : vec3(0.0f);
+	dir_diff_color += vis ? v_lights[l]->diffuse(n, r, i_pos, _f->m_mat) : vec3(0.0f);
+	dir_spec_color += vis ? v_lights[l]->specular(n, r, i_pos, _f->m_mat) : vec3(0.0f);
       }
       
       color += (dir_diff_color * (_f->m_mat.m_diffuse / pi<float>())) + dir_spec_color;