int nsprings = 4;
MySpring [] s = new MySpring[nsprings];
void setup() {
  size(200, 200);
  for(int i=0; i<nsprings; i++){
    s[i] = new MySpring();
    s[i].xpos = random(width);
    s[i].ypos = random(height);
    s[i].Rx = s[i].xpos;
    s[i].Ry = s[i].ypos;
  }
}
void draw() {
  background(200);
  for(int i=0; i<nsprings; i++){
    if(s[i].released)s[i].move();
    ellipse(s[i].xpos, s[i].ypos , 10,10);
  }
  for(int i=0; i<nsprings-1; i++)
    line(s[i].xpos, s[i].ypos ,s[i+1].xpos, s[i+1].ypos);
}
void mouseDragged() {
  for(int i=0; i<nsprings; i++)
    if(dist(mouseX,mouseY,s[i].xpos,s[i].ypos)<10){
      s[i].released = false;
      s[i].xpos = mouseX;
      s[i].ypos = mouseY;
    }
}
void mouseReleased(){
  for(int i=0; i<nsprings; i++)
    s[i].released = true;
}