Thing t;
Attractor a;
boolean showVectors = true;

void setup() {
  size(900,400);
  framerate(30);
  background(0);
  colorMode(RGB,255,255,255,100);
  Vector3D ac = new Vector3D(0.0,0.0);
  Vector3D ve = new Vector3D(0.0,1.0);
  Vector3D lo = new Vector3D(50,50);
  t = new Thing(ac,ve,lo,1);
  a = new Attractor(new Vector3D(width/2,height/2),20,0.4);
}

void draw() {
  background(0);
  smooth();
  a.rollover(mouseX,mouseY);
  Vector3D f = a.calcGravForce(t);
  t.add_force(f);
  t.go();
  a.go();

}

void mousePressed() {
  a.clicked(mouseX,mouseY);
}

void mouseReleased() {
  a.stopDragging();
}

void keyPressed() {
  showVectors = !showVectors;
}
void drawVector(Vector3D v, Vector3D loc, float scab) {
  if (v.magnitude() > 0.0) {
    pushMatrix();
    translate(loc.x,loc.y);
    stroke(255);
    rotate(v.heading2D());

    float len = v.magnitude()*scab;
    popMatrix();
  }
}