public class PhysicsObject {
  public float x;
  public float y;
  public float v_x;
  public float v_y;

  public static int width = 0;
  public static int height = 0;
  public static float max_speed = 0;

  public void simulate() {
    v_x = clamp(v_x, -max_speed, max_speed) * 0.998f;
    v_y = clamp(v_y, -max_speed, max_speed) * 0.998f;

    x += v_x;
    y += v_y;
    while (x < 0) {
      x += width;
    }
    while (y < 0) {
      y += height;
    }
    x %= width;
    y %= height;
  }

  private float clamp(float f, float min, float max) {
    return Math.min(max, Math.max(f, min));
  }

  public void apply_force(float x, float y, float factor) {
    if ((x == 0 && y == 0) || factor == 0)
      return;
    double len = Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
    v_x += (x / len) * factor;
    v_y += (y / len) * factor;
  }

  public PhysicsObject(int x, int y, float v_x, float v_y) {
    this.x = x;
    this.y = y;
    this.v_x = v_x;
    this.v_y = v_y;
  }

  public double get_sqr_distance(PhysicsObject obj) {
    return Math.pow(obj.x - x, 2) + Math.pow(obj.y - y, 2);
  }
}