I've run into this several times trying to use and understand other people's code.  Since the code was posted, I assume it used to work, but won't now.  What does this mean and how can I fix it?


/**
 * a very light wrapper around a PImage that tracks the mouse
 */
class MouseImage {
  PImage img;
  MouseImage(String filename) {
    img = loadImage(filename);
  }
  void draw() {
    translate(mouseX-img.width/2f, mouseY-img.height/2f, 0.1f);
    image(img, 0, 0);
  }
}