class Leaf {
    int x, y;  //the leaf's position
    PImage picture;  //an image object
    int rate;  //rate of waiting to be redrawn
  
    Leaf(){   //constructor
      x = int(random(width));  //get an initial location
      y = int(random(height));
      picture = loadImage("maple_leaf.gif");  //get the image
    }
  
  int k=0;   //a counter 
    void draw() {
      if(k==rate){  //if the counter is as the rate then draw
        x += int(random(-5,5));  //random tremblings
        y += int(random(-5,5));
        k=0;  //reset the counter
        }
      k++;  //increate the counter; during every increment there is no draw 
        image(picture,x,y);  //now draw the image
      }
    }