#include "magnetism.h"
#include "consts.h"
#include "vec_utils.h"
#include <math.h>

#define EPSILON 8.85418782E-12

void magnetism(universe_t* uni){
  mass_body_t body_1;
  mass_body_t body_2;
  Vector2 diff, force;
  for (unsigned int i = 0; i < uni->num_bodies-1; i++) {
    body_1 = uni->bodies[i];
      for (unsigned int y = i + 1; y < uni->num_bodies; y++) {
        body_2 = uni->bodies[y];
        diff=vec2_diff(body_2.position,body_1.position);
        force = vec2_scale(diff,body_1.charge*body_2.charge/(4*PI*EPSILON*vec2_len(diff)));
        body_1.speed=vec2_sum(body_1.speed,vec2_scale(force,1/body_1.mass));
        body_2.speed=vec2_diff(body_2.speed,vec2_scale(force,1/body_2.mass));
        uni->bodies[y] = body_2;
    }
    uni->bodies[i] = body_1;
  }
}