Engine Restructure

My suggestion would be to componentize everything.

For example your character collision. You should have a character collision class, it's a part of your physics library. By instantiating one of these objects and registering it with the physics engine, the character collision object will interact with the world.

Then in your character object class, you maintain one of these character collision objects and extract and inject data into it as necessary.

For ex:

struct CharacterObj {   CharacterPhys physicsBody;  GraphicsMesh graphics;  CharacterObj() {    //you're gonna wanna register it to a specific system    PhysicsSystem::RegisterBody(&physicsBody);    RenderingSystem::RegisterRenderable(&graphics);  }    void Update(float dt) {    //very simple example    graphics.Transform = physicsBody.Transform;  }};

As you can see, CharacterObj has no idea about how to do collision, or wether or not the physics body is even being updated. All it knows is that the resultant transform from the physics representation is where the graphics representation should be.

You could very easily add more components to the CharacterObj for stats as you mentioned, and network presence, input system. The character object should be thought of as an Entity and could be written like this:

struct Entity {  std::vector<Component*> Components;};

Merely a collection of components which are all simply "keys" into their respective system. The CharacterPhys is just a key into the physics system. The GraphicsMesh is just a key into the graphics system, likewise for input, networking, scripting, sound, effects, animation, etc. All that would get very complicated if it were all implemented in the character.

When you compose things with components it's like building blocks that can be reused as often or as little as you want.