Function hilbert_2d::usize::h2xy_discrete

pub const fn h2xy_discrete(
    h: usize,
    order: usize,
    variant: Variant
) -> (usize, usize)

Maps from a 1D index to a 2D coordinate, using a discrete approximation of the Hilbert curve. Recommended for images and matrices.

Given h, this method calculates the (x, y) coordinates for that index, in the Hilbert curve approximation of order.

The value of h must be in the range 0 <= h < 2^(2 * order). The coordinates returned will be in the range 0 <= x/y < 2^order.

With b being the number of bits in a usize for the target platform, the highest approximation order achievable by this method is b / 2. Therefore, the parameter order must be in the range 1 <= order <= b / 2.

The pattern of the Hilbert curve to be constructed must be indicated by the variant parameter. See Variant for more details.

Examples

Basic usage:

use hilbert_2d::{Variant, usize::h2xy_discrete};

// Hilbert curve of order 2:
//  5 ―― 6    9 ― 10
//  |    |    |    |
//  4    7 ―― 8   11
//  |              |
//  3 ―― 2   13 ― 12
//       |    |
//  0 ―― 1   14 ― 15
let (x, y) = h2xy_discrete(7, 2, Variant::Hilbert);

assert_eq!(x, 1);
assert_eq!(y, 2);