HLine h1 = new HLine(); 
float[] speeds = new float[3]; 
float ypos; 
 
void setup() { 
  size(200, 200); 
  speeds[0] = 0.1; 
  speeds[1] = 2.0; 
  speeds[2] = 0.5; 
} 
 
void draw() { 
  ypos += speeds[int(random(3))]; 
  if (ypos > width) { 
    ypos = 0; 
  } 
  h1.update(ypos); 
} 
 
class HLine { 
  void update(float y) { 
    line(0, y, width, y); 
  } 
}