From 06cb7e884069d625b958f9d61863b84c8cae6278 Mon Sep 17 00:00:00 2001
From: Miguel Angel Astor Romero <sonofgrendel@gmail.com>
Date: Tue, 28 Mar 2017 10:31:39 -0400
Subject: [PATCH] Photon tracer ready (I think).

---
 photon_tracer.cpp  | 40 ++++++++++++++++++++++++----------------
 scenes/scene5.json | 14 ++++++++++++--
 2 files changed, 36 insertions(+), 18 deletions(-)

diff --git a/photon_tracer.cpp b/photon_tracer.cpp
index b150f6a..53a71be 100644
--- a/photon_tracer.cpp
+++ b/photon_tracer.cpp
@@ -32,9 +32,9 @@ using namespace glm;
 PhotonTracer::~PhotonTracer() { }
 
 vec3 PhotonTracer::trace_ray(Ray & r, Scene * s, unsigned int rec_level) const {
-  float t, _t, red, green, blue, kr, radius;
+  float t, _t, red, green, blue, kr, radius, r1, r2;
   Figure * _f;
-  vec3 n, color, i_pos, ref, dir_diff_color, dir_spec_color, p_contrib;
+  vec3 n, color, i_pos, ref, dir_diff_color, dir_spec_color, p_contrib, sample, amb_color;
   Ray mv_r, sr, rr;
   bool vis, is_area_light;
   AreaLight * al;
@@ -110,17 +110,7 @@ vec3 PhotonTracer::trace_ray(Ray & r, Scene * s, unsigned int rec_level) const {
 	dir_spec_color += vis ? s->m_lights[l]->specular(n, r, i_pos, *_f->m_mat) : vec3(0.0f);
       }
 
-      // TODO: Change photon map search method for hemisphere search.
-      // radius = m_h_radius;
-      // mn = Vec3(i_pos.x - radius, i_pos.y - radius, i_pos.z - radius);
-      // mx = Vec3(i_pos.x + radius, i_pos.y + radius, i_pos.z + radius);
-
-      // while((photons =  m_photon_map.findInRange(mn, mx)).size() == 0 && radius < 5.0) {
-      // 	radius *= 2;
-      // 	mn = Vec3(i_pos.x - radius, i_pos.y - radius, i_pos.z - radius);
-      // 	mx = Vec3(i_pos.x + radius, i_pos.y + radius, i_pos.z + radius);
-      // }
-
+      // Calculate photon map contribution
       radius = m_h_radius;
       m_photon_map.find_by_distance(photons, i_pos, n, m_h_radius, 1000);
       while(photons.size() == 0 && radius < 5.0) {
@@ -142,10 +132,28 @@ vec3 PhotonTracer::trace_ray(Ray & r, Scene * s, unsigned int rec_level) const {
       }
 
       p_contrib /= (1.0f - (2.0f / (3.0f * m_cone_filter_k))) * pi<float>() * (radius * radius);
+
+      // Calculate environment light contribution
+      vis = true;
+
+      r1 = random01();
+      r2 = random01();
+      sample = sample_hemisphere(r1, r2);
+      rotate_sample(sample, n);
+      rr = Ray(normalize(sample), i_pos + (sample * BIAS));
+
+      // Cast a shadow ray to determine visibility.
+      for (size_t f = 0; f < s->m_figures.size(); f++) {
+	if (s->m_figures[f]->intersect(rr, _t)) {
+	  vis = false;
+	  break;
+	}
+      }
+
+      amb_color = vis ? s->m_env->get_color(rr) * max(dot(n, rr.m_direction), 0.0f) / PDF : vec3(0.0f);
       
-      // color += (1.0f - _f->m_mat->m_rho) * ((dir_diff_color * (_f->m_mat->m_diffuse / pi<float>())) +
-      // 					    (_f->m_mat->m_specular * dir_spec_color)  + p_contrib);
-      color += (1.0f - _f->m_mat->m_rho) * p_contrib;
+      color += (1.0f - _f->m_mat->m_rho) * (((dir_diff_color + p_contrib + amb_color) * (_f->m_mat->m_diffuse / pi<float>())) +
+      					    (_f->m_mat->m_specular * dir_spec_color));
 
       // Determine the specular reflection color.
       if (_f->m_mat->m_rho > 0.0f && rec_level < m_max_depth) {
diff --git a/scenes/scene5.json b/scenes/scene5.json
index 65d0c96..aa84804 100644
--- a/scenes/scene5.json
+++ b/scenes/scene5.json
@@ -7,12 +7,22 @@
 	"position": [0.0, 0.0, -2.0],
 	"radius": 0.5,
 	"material": {
-	    "diffuse": [1.0, 1.0, 0.0],
+	    "diffuse": [1.0, 1.0, 1.0],
 	    "transmissive": true,
 	    "ref_index": 1.33
 	}
     },
 
+    "sphere": {
+	"position": [0.0, 0.0, -2.0],
+	"radius": 0.25,
+	"material": {
+	    "diffuse": [1.0, 1.0, 1.0],
+	    "transmissive": true,
+	    "ref_index": 1.0
+	}
+    },
+
     "disk_area_light": {
 	"position": [0.0, 1.0, -2.0],
 	"normal": [0.0, -1.0, 0.0],
@@ -26,7 +36,7 @@
 	"position": [0.0, -1.0, 0.0],
 	"normal": [0.0, 1.0, 0.0],
 	"material": {
-	    "diffuse": [0.0, 0.5, 1.0],
+	    "diffuse": [1.0, 1.0, 0.2],
 	    "specular": [0.0, 0.0, 0.0]
 	}
     }