float ax1,ax2,bx1,bx2,cx1,cx2;
float x;  // Kreis

void setup() { 
  size(200,200); 
  noStroke();
  ellipseMode(CENTER_DIAMETER);
  
  ax1=-42;
  x=(width)+30;


}

void loop() {
  background(255,255,255);
  ax2=ax1+20;

stroke(0,0,0);
line(ax1,65, ax2,65);
  ax1=ax1+2;
if(ax1>width) {
  ax1=-42;  
}
line(bx1,90, bx2,90);
  bx1=ax1;
  bx2=ax2;
line(cx1,115, cx2,115);
  cx1=ax1;
  cx2=ax2;

  noFill();
  stroke(0,0,0);  
ellipse(x,90, 15,15);
  x=x-2;
if(x<-10) {
x=(width)+30;
}
}