Move geometry structs to own file

Also, the Ray got an unimplemented `intersects_triangle` method, so the kdtree intersection function should be complete.

geometry.h

@@ -0,0 +1,57 @@
+// Forward declarations
+struct Point;
+
+struct Node {
+    Node(int axis, Point *point, Node *left, Node *right)
+        : axis(axis), point(point), left(left), right(right) {}
+
+    int axis;
+
+    Point *point;
+
+    Node *left;
+    Node *right;
+};
+
+struct Triangle {
+    Triangle(Point *p1, Point *p2, Point *p3) : p1(p1), p2(p2), p3(p3) {}
+
+    Point *p1;
+    Point *p2;
+    Point *p3;
+};
+
+struct Point {
+    Point(float coordinates[3], Triangle *triangle)
+        : coordinates(coordinates), triangle(triangle) {}
+
+    Point operator+(const Point &other) const {
+        return Point(new float[3]{coordinates[0] + other.coordinates[0],
+                                  coordinates[1] + other.coordinates[1],
+                                  coordinates[2] + other.coordinates[2]},
+                     nullptr);
+    }
+
+    Point operator*(float scalar) const {
+        return Point(
+            new float[3]{coordinates[0] * scalar, coordinates[1] * scalar, coordinates[2] * scalar},
+            nullptr);
+    }
+
+    float *coordinates;
+
+    Triangle *triangle;
+};
+
+struct Ray {
+    Ray(float origin[3], float direction[3]) : origin(origin), direction(direction) {}
+
+    float *origin;
+
+    float *direction;
+
+    bool intersects_triangle(Triangle *triangle) {
+        // TODO
+        return false;
+    }
+};

kdtree.h

@@ -1,64 +1,10 @@
+#include "geometry.h"
 #include <algorithm>
 #include <glm/glm.hpp>
 #include <iostream>
 #include <string>
 #include <vector>
 
-// Forward declarations
-struct Node;
-struct Point;
-struct Triangle;
-
-struct Node {
-    Node(int axis, Point *point, Node *left, Node *right)
-        : axis(axis), point(point), left(left), right(right) {}
-
-    int axis;
-
-    Point *point;
-
-    Node *left;
-    Node *right;
-};
-
-struct Triangle {
-    Triangle(Point *p1, Point *p2, Point *p3) : p1(p1), p2(p2), p3(p3) {}
-
-    Point *p1;
-    Point *p2;
-    Point *p3;
-};
-
-struct Point {
-    Point(float coordinates[3], Triangle *triangle)
-        : coordinates(coordinates), triangle(triangle) {}
-
-    Point operator+(const Point &other) const {
-        return Point(new float[3]{coordinates[0] + other.coordinates[0],
-                                  coordinates[1] + other.coordinates[1],
-                                  coordinates[2] + other.coordinates[2]},
-                     nullptr);
-    }
-
-    Point operator*(float scalar) const {
-        return Point(
-            new float[3]{coordinates[0] * scalar, coordinates[1] * scalar, coordinates[2] * scalar},
-            nullptr);
-    }
-
-    float *coordinates;
-
-    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); }
@@ -160,8 +106,10 @@ class KDTree {
         if (near_result != nullptr) { return near_result; }
 
         // No collision in the nearer side, so check for a collision directly here
-        Point *collision_here = nullptr;
-        // TODO: Ray-triangle-intersection here
+        if (ray.intersects_triangle(node->point->triangle)) {
+            // We do have a collision here, so we're done and can return this point!
+            return node->point;
+        }
 
         // No collision here either. Does it make sense to also check the far node?
         // Only if the axes are not parallel and if that area is not behind us