static Rect growRect(Rect r, int pixels) {
  ret new Rect(r.x-pixels, r.y-pixels, r.w+pixels*2, r.h+pixels*2);
}

static Rect growRect(Rect r, int x, int y) {
  ret new Rect(r.x-x, r.y-y, r.w+x*2, r.h+y*2);
}