fix octree corruption bug because of node vector reallocation

include/config.hpp

@@ -4,8 +4,8 @@
 #include <raylib.h>
 
 #define PRINT_TIMINGS
-// #define WEB // Disables multithreading
 #define BARNES_HUT // Use octree BH instead of uniform grid
+// #define WEB        // Disables multithreading
 
 // Window
 constexpr int INITIAL_WIDTH = 800;
@@ -31,7 +31,7 @@ constexpr float ROT_SPEED = 1.0;
 
 // Physics Engine
 constexpr float SIM_SPEED = 4.0;          // How large each update should be
-constexpr float TIMESTEP = 1.0 / 60;      // Do 60 physics updates per second
+constexpr float TIMESTEP = 1.0 / 90;      // Do 90 physics updates per second
 constexpr float MASS = 1.0;               // Mass spring system
 constexpr float SPRING_CONSTANT = 5.0;    // Mass spring system
 constexpr float DAMPENING_CONSTANT = 1.0; // Mass spring system

include/octree.hpp

@@ -20,7 +20,8 @@ public:
       : mass_center(Vector3Zero()), mass_total(0.0),
         children(-1, -1, -1, -1, -1, -1, -1, -1), mass_id(-1), leaf(true) {}
 
-  ~OctreeNode() {}
+public:
+  auto ChildCount() const -> int;
 };
 
 class Octree {
@@ -35,8 +36,6 @@ public:
   Octree(Octree &&move) = delete;
   Octree &operator=(Octree &&move) = delete;
 
-  ~Octree() {}
-
 public:
   auto CreateNode(const Vector3 &box_min, const Vector3 &box_max) -> int;
 
@@ -47,7 +46,9 @@ public:
   auto Insert(int node_idx, int mass_id, const Vector3 &pos, float mass)
       -> void;
 
-  auto CalculateForce(int node_idx, const Vector3 &pos) -> Vector3;
+  auto CalculateForce(int node_idx, const Vector3 &pos) const -> Vector3;
+
+  auto Print() const -> void;
 };
 
 #endif

include/physics.hpp

@@ -106,8 +106,6 @@ public:
   MassSpringSystem(MassSpringSystem &move) = delete;
   MassSpringSystem &operator=(MassSpringSystem &&move) = delete;
 
-  ~MassSpringSystem() {};
-
 private:
 #ifdef BARNES_HUT
   auto BuildOctree() -> void;