Snake S = new Snake(4);
float dim=400;
class Snake {
   int maxnb=100;  
   int nb=0;  // number of balls
   int b=0; // index of picked ball
   float r[] = new float [maxnb];  // radii of balls
   pt C[] = new pt [maxnb];    // centers of balls 
   Snake() {for (int i=0; i<maxnb; i++) C[i]=new pt();}
   Snake(int n) {for (int i=0; i<maxnb; i++) C[i]=new pt(); nb=n; for (int i=0; i<nb; i++) {C[i].setTo(0,-80.*i,0); r[i]=10*i+random(20);};}
 
  void reset() {nb=0;}
  void add(pt P, float pr) {C[nb].setTo(P); r[nb++]=pr; }
  void changeRadius() {r[b]+=(mouseX-pmouseX)/10.; if(r[b]<1) r[b]=1;  }
 
  void showBalls() { for (int i=0; i<nb; i++)  C[i].show(r[i]); };    

  boolean pickBall (pt M) {boolean picked = false; float dm=10000.0; 
    for (int i=0; i<nb; i++)  {
      float dd = M.disTo(C[i]); 
      if((dd<r[i]*1.1)&&(dd<dm)) {picked=true; dm=M.disTo(C[i]); b=i; };  }; return picked;}
 
  void showCaplets(int s) {for (int i=0; i<nb-1; i++)  showCone(C[i],r[i],C[i+1],r[i+1],s);}
 
   }  // end Snake class