Refraction seems to work. Still need to do a nice scene.

source/include/intersection.h

@@ -18,14 +18,16 @@ class Intersect;
 struct Computation
 {
     Computation(Shape *object, double t, Tuple point, Tuple eyev, Tuple normalv, Tuple overHitP,
-                bool inside, Tuple reflectV = Vector(0, 0, 0), double n1 = 1.0, double n2 = 1.0) :
+                bool inside, Tuple reflectV = Vector(0, 0, 0), double n1 = 1.0, double n2 = 1.0,
+                Tuple underHitP = Point(0, 0, 0)) :
           object(object), t(t), hitPoint(point), eyeVector(eyev), normalVector(normalv), inside(inside),
-          overHitPoint(overHitP),  reflectVector(reflectV), n1(n1), n2(n2) { };
+          overHitPoint(overHitP), underHitPoint(underHitP), reflectVector(reflectV), n1(n1), n2(n2) { };
 
     Shape *object;
     double t;
     Tuple hitPoint;
     Tuple overHitPoint;
+    Tuple underHitPoint;
     Tuple eyeVector;
     Tuple normalVector;
     Tuple reflectVector;

source/include/list.h

@@ -44,13 +44,31 @@ public:
     {
         ChainList *p = this->head;
         if (p == nullptr) { return; }
+
+        if ((p->next == nullptr) && (p->shape == s))
+        {
+            /* First element */
+            this->tail = nullptr;
+            free(this->head);
+            this->head = nullptr;
+            this->count = 0;
+
+            return;
+        }
+
         while(p->next != nullptr)
         {
             if (p->next->shape == s)
             {
-                this->count --;
+                ChainList *found = p->next;
+
                 p->next = p->next->next;
-                free(p->next);
+
+                free(found);
+
+                if (p->next == NULL) { this->tail = p; }
+
+                this->count --;
                 return;
             }
             p = p->next;
@@ -64,10 +82,10 @@ public:
         theNew->shape = s;
 
         ChainList *p = this->tail;
-        tail = theNew;
+        this->tail = theNew;
 
         if (p != nullptr) { p->next = theNew; }
-        else { head = theNew; } /* If the tail is empty, it mean the list IS empty. */
+        else { this->head = theNew; } /* If the tail is empty, it mean the list IS empty. */
 
         this->count ++;
     }

source/include/world.h

@@ -47,6 +47,7 @@ public:
     bool isShadowed(Tuple point);
 
     Colour reflectColour(Computation comps, uint32_t depthCount = 4);
+    Colour refractedColour(Computation comps, uint32_t depthCount = 0);
 
     Intersect intersect(Ray r);