Physics.h

#ifndef PHYSICS_H
#define PHYSICS_H

#include "Creature.h"
#include <list>
#include <SDL_timer.h>

struct State
{
    double x;      // position
    double v;      // velocity
};

struct Derivative
{
    double dx;      // dx/dt = velocity
    double dv;      // dv/dt = acceleration
};

class Physics
{
public:
    Physics(int boundaryWidth, int boundaryHeight);

    Physics(Physics const&) = delete;
    
    ~Physics();
    
    double update(std::list<Object*>& objectList);

    Physics& operator=(Physics const&) = delete; 
    
private:
    double t;
    
    const double dt;
    
    double currentTime;

    double accumulator;

    int boundaryWidth;
    
    int boundaryHeight;

    void integrate(State& state, double t, double dt, bool isY);
    
    Derivative evaluate(State const& initial, double t, double dt, Derivative const& d, bool isY);

    double acceleration(const State &state, double t);

    void checkCollision(std::list<Object*>& objectList);
};

#endif // PHYSICS_H