void setup(){
  size(200,200);
  background(255);
  framerate(30);
}
void draw(){
  smooth();
  int posx = int(random(0,200));
  // Calcul de la position posY
  int posy;
  if (posx > 50 && posx < 150){
    posy = (round(random(50,100))*((round(random(1))*2)-1))+100;
  }
  else {
    posy = int(random(0,200));
  }
  stroke(random(255),random(255),random(255));
  strokeWeight(random(3));
  line(random(50,150),random(50,150),posx,posy);
}