Added direct diffuse lighting.

tracer.cpp

@@ -1,3 +1,4 @@
+#include <iostream>
 #include <limits>
 #include <cstdlib>
 #include <cmath>
@@ -8,8 +9,17 @@
 
 using namespace std;
 
+using std::numeric_limits;
+using glm::normalize;
+using glm::radians;
+using glm::dot;
+
 static const vec3 BCKG_COLOR = vec3(0.16f, 0.66f, 0.72f);
 
+static inline float max(float a, float b) {
+  return a >= b ? a : b;
+}
+
 static inline float random01() {
   return static_cast<float>(rand()) / static_cast<float>(RAND_MAX);
 }
@@ -35,23 +45,32 @@ vec2 Tracer::sample_pixel(int i, int j) const {
 }
 
 vec3 Tracer::trace_ray(Ray & r, vector<Figure *> & vf, vector<Light *> & vl, unsigned int rec_level) const {
-  float t;
-  float _t;
+  float t, _t, n_dot_l;
   Figure * _f;
-  vec3 n;
+  vec3 n, color, i_pos;
+  vec3 light_dir;
 
   t = numeric_limits<float>::max();
   _f = NULL;
   
   for (size_t f = 0; f < vf.size(); f++) {
-    if (vf[f]->intersect(r, _t, n) && _t < t) {
+    if (vf[f]->intersect(r, _t) && _t < t) {
       t = _t;
       _f = vf[f];
     }
   }
   
-  if (_f != NULL)
-    return _f->color;
-  else
+  i_pos = r.m_origin + (t * r.m_direction);
+
+  if (_f != NULL) {
+    for (size_t l = 0; l < vl.size(); l++) {
+      n = _f->normal_at_int(r, t);
+      light_dir = vl[l]->m_position;
+      n_dot_l = max(dot(n, light_dir), 0.0);
+      color += (_f->color / 3.1416f) * vl[l]->m_diffuse * n_dot_l;
+    }
+
+    return color;
+  } else
     return vec3(BCKG_COLOR);
 }