patterns — contour

def g02_contour(rng):
    """A long ramp on a warped mesh — contour lines fall out of the quantiser."""
    steps = rng.randint(10, 12)
    c = Canvas(rng.choice([40, 50]), _pal(rng), steps, "contour", "mosaic")
    c.ground_from(Field(rng, "mesh", warp=rng.uniform(0.35, 0.7), steps=steps))
    return c