static int area(Rect r) {
  ret rectArea(r);
}

static double area(DoubleRect r) {
  ret r == null ? 0 : r.w*r.h;
}

ifclass WidthAndHeight
static int area(WidthAndHeight img) {
  ret img == null ? 0 : img.getWidth()*img.getHeight();
}
endif

static int area(BufferedImage img) {
  ret img == null ? 0 : img.getWidth()*img.getHeight();
}