class field {
  Vector3D loc,force;
  float size;
  float magnitude;
  float x,y, degree;
  field(Vector3D loc_, Vector3D vel_, float size_) {
    loc = loc_;
    //vel = vel_;
    size = size_;
    // cal

  }

  void draw() {
    rectMode(CORNER);
    fill(100,10);
   // rect(loc.x,loc.y,size,size);
    stroke(255);
   // line(loc.x,loc.y,loc.x+force.x,loc.y+force.y);
  }

  public void calcForce(Vector3D v) {
     float theta = Vector3D.angleBetween(v,loc);
      degree = radians(theta);
     float magnitude = Vector3D.distance(v,loc);
     x = magnitude * cos(degree);
     y = magnitude * sin(degree);
     
    // println(x);
    
    force = Vector3D.sub(v,loc);
   // println(force);
    force.normalize();
   force.mult(2);
  }

  public boolean isParticleInside(Particle p) {
    float dist = Vector3D.distance(p.getLoc(),loc);
    if (dist < size) {
      return true;
    } 
    else {
      return false;
    }
  }


}