Stable Hilbert curve

A stabilized version of a Hilbert curve, more suitable for Hilbert treemaps. Odd orders are rotated by 90 degrees and flipped along Y, making each curve overlappable to each other (click the canvas to see it).

Classical Hilbert curves of even order cannot be overlapped with Hilbert curves of odd order (see this example showing it). Peano curves are not affected by this problem (see here).