14-1. A Recursive Algorithm for Generating the Hilbert Curve
To see how to generate a Hilbert curve, examine the curves in Figure 14-2. The order 1 curve goes up, right, and down. The order 2 curve follows this overall pattern. First, it makes a U-shaped curve that goes up, in net effect. Second, it takes a unit step up. Third, it takes a U-shaped curve, a step, and another U, all to the right. Finally, it takes a step down, followed by a U that goes down, in net effect.
Figure 14-2. Hilbert curves of orders 1-6.
The order 1 inverted U is converted into the order 2 Y-shaped curve.
We can regard the Hilbert curve of any order as a series of ...