static BWImage bwImageFromFunction(int w, int h default w, IF2<Int, Int, Double> f) {
  BWImage img = new(w, h);
  for y to h:
    for x to w:
      img.setPixel(x, y, (float) f.get(x, y));
  ret img;
}

static BWImage bwImageFromFunction(int w, int h default w, IF0<Double> f) {
  ret bwImageFromFunction(w, toIF2(f));
}