Moved area light base class to it's own file.

area_light.hpp

@@ -0,0 +1,86 @@
+#pragma once
+#ifndef AREA_LIGHT_HPP
+#define AREA_LIGHT_HPP
+
+#include "light.hpp"
+
+using glm::length;
+using glm::normalize;
+using glm::dot;
+
+class AreaLight: public Light {
+public:
+  float m_const_att;
+  float m_lin_att;
+  float m_quad_att;
+  Figure * m_figure;
+
+  AreaLight():
+    Light(AREA),
+    m_const_att(1.0),
+    m_lin_att(0.0),
+    m_quad_att(0.0),
+    m_figure(NULL),
+    m_last_sample(vec3()),
+    m_n_at_last_sample(vec3())
+  { }
+
+  AreaLight(Figure * _f, float _c = 1.0, float _l = 0.0, float _q = 0.0):
+    Light(AREA),
+    m_const_att(_c),
+    m_lin_att(_l),
+    m_quad_att(_q),
+    m_figure(_f),
+    m_last_sample(vec3()),
+    m_n_at_last_sample(vec3())
+  { }
+
+  virtual vec3 direction(vec3 point) const {
+    return normalize(m_last_sample - point);
+  }
+
+  virtual float distance(vec3 point) const {
+    return length(m_last_sample - point);
+  }
+
+  vec3 diffuse(vec3 normal, Ray & r, vec3 i_pos, Material & m) const {
+    float d, att, ln_dot_d, d2, g;
+    vec3 l_dir, ref;
+
+    l_dir = normalize(direction(i_pos));
+    ln_dot_d = dot(m_n_at_last_sample, l_dir);
+    if (ln_dot_d > 0.0f) {
+      d2 = distance(i_pos);
+      d2 *= d2;
+      g = ln_dot_d / d2;
+      d = distance(i_pos);
+      att = 1.0f / (m_const_att + (m_lin_att * d) + (m_quad_att * (d * d)));
+      return (att * m.m_brdf->diffuse(l_dir, normal, r, i_pos, m_figure->m_mat->m_emission) * g) / m_figure->pdf();
+
+    } else
+      return vec3(0.0f);
+  }
+
+  vec3 specular(vec3 normal, Ray & r, vec3 i_pos, Material & m) const {
+    float d, att, ln_dot_d;
+    vec3 l_dir, ref;
+
+    l_dir = normalize(direction(i_pos));
+    ln_dot_d = dot(m_n_at_last_sample, l_dir);
+    if (ln_dot_d > 0.0f) {
+      d = distance(i_pos);
+      att = 1.0f / (m_const_att + (m_lin_att * d) + (m_quad_att * (d * d)));
+      return (att * m.m_brdf->specular(l_dir, normal, r, i_pos, m_figure->m_mat->m_emission, m.m_shininess)) / m_figure->pdf();
+
+    } else
+      return vec3(0.0f);
+  }
+
+  virtual void sample_at_surface(vec3 point) = 0;
+
+protected:
+  vec3 m_last_sample;
+  vec3 m_n_at_last_sample;
+};
+
+#endif