Add empty implementation for ray intersection

kdtree.h

@@ -37,11 +37,21 @@ struct Point {
     Triangle *triangle;
 };
 
+struct Ray {
+    Ray(float origin[3], float direction[3]) : origin(origin), direction(direction) {}
+
+    float *origin;
+
+    float *direction;
+};
+
 class KDTree {
   public:
     KDTree(std::vector<Point *> points) { root = build(points, 0); }
 
-    ~KDTree() = default;
+    ~KDTree() = default; // TODO: Delete all allocated Nodes
+
+    Point *intersect_ray(Ray ray) { return intersect_ray_recurse(ray, root); }
 
     std::string to_string() {
         std::string str = "";
@@ -105,6 +115,14 @@ class KDTree {
                         build(right_of_median, depth + 1));
     }
 
+    Point *intersect_ray_recurse(Ray ray, Node *node) {
+        // Intersect ray with the point's splitting plane
+        // If there is an intersection: Recurse to both children (but the nearer one first)
+        // Otherwise: Recurse only to the nearer one
+
+        return node->point; // TODO
+    }
+
     void to_string_recurse(std::string &str, Node *node, int depth) {
         if (node == nullptr) { return; }