// generate some objects
Random rnd = new Random();
// addEntity(new GoalEntity(this, width/2, height/2, 1), 300);
addEntity( new JointAttractor(this, (int)(width * 0.5), (int)(height * 0.2) ));
addEntity( new JointAttractor(this, (int)(width * 0.2), (int)(height * 0.7) ));
addEntity( new JointAttractor(this, (int)(width * 0.2), (int)(height * 0.8) ));
// repulsors
for (int i = 0; i < 3; i++)
addEntity(new BigRepulsor(this, rnd.nextInt(width), rnd
.nextInt(height)));