Hacker's Delight

14-6. Other Space-Filling Curves

As was mentioned, Peano was first, in 1890, to discover a space-filling curve. The many variations discovered since then are often called “Peano curves.” One interesting variation of Hilbert’s curve was discovered by Eliakim Hastings Moore in 1900. It is “cyclic” in the sense that the end point is one step away from the starting point. The Peano curve of order 3, and the Moore curve of order 4, are shown in Figure 14-13. Moore’s curve has an irregularity in that the order 1 curve is up-right-down but this shape does not appear in the higher-order curves. Except for this minor exception, the algorithms for dealing ...