calculate ambient, diffuse and specular

src/Geometry.cc

@@ -9,6 +9,7 @@ Vector3f Geometry::ambient() const { return ca; }
 float Geometry::coefDiffuse() const { return kd; }
 float Geometry::coefSpecular() const { return ks; }
 float Geometry::coefAmbient() const { return ka; }
+float Geometry::getPhong() const { return phong; }
 
 void Geometry::setTransform(const Matrix4f &transform) {
   this->transform = transform;

src/Geometry.h

@@ -39,6 +39,7 @@ public:
   float coefDiffuse() const;
   float coefSpecular() const;
   float coefAmbient() const;
+  float getPhong() const;
   void setTransform(const Matrix4f &);
 };
 

src/HitRecord.cc

@@ -10,6 +10,10 @@ Vector3f HitRecord::getPoint() const {
   return r.getOrigin() + t * r.getDirection();
 }
 
+Vector3f HitRecord::viewDirection() const {
+  return -r.getDirection().normalized();
+}
+
 Vector3f HitRecord::normal() const { return n; }
 
 void HitRecord::calcNormal() { n = g->getNormal(getPoint()); }

src/HitRecord.h

@@ -21,6 +21,7 @@ private:
 public:
   Geometry *geometry() const;
   Vector3f getPoint() const;
+  Vector3f viewDirection() const;
   Vector3f normal() const;
   void calcNormal();
 };

src/Light.cc

@@ -1,4 +1,6 @@
 #include "Light.h"
+#include <algorithm>
+#include <cmath>
 
 void Light::setTransform(const Matrix4f &transform) {
   this->transform = transform;
@@ -19,7 +21,18 @@ Vector3f PointLight::illumination(const HitRecord &hit,
     if (g != geometry && g->intersect(shadowRay).hasValue())
       return Vector3f::Zero();
 
-  return Vector3f::Zero();
+  float distance = (center - shadingPoint).norm();
+  float att = 1.0f / distance / distance;
+
+  Vector3f ambient_ = geometry->coefAmbient() * geometry->ambient();
+  Vector3f diffuse_ = att * geometry->coefDiffuse() * diffuse *
+                      std::max(0.0f, hit.normal().dot(rayDirection));
+
+  Vector3f halfWay = (hit.viewDirection() + rayDirection).normalized();
+  Vector3f specular_ =
+      att * geometry->coefSpecular() * specular *
+      pow(std::max(0.0f, hit.normal().dot(halfWay)), geometry->getPhong());
+  return ambient_ + diffuse_ + specular_;
 }
 
 Vector3f AreaLight::illumination(const HitRecord &hit,