Function hilbert_2d::h2xy_continuous_f64

pub fn h2xy_continuous_f64(h: f64, variant: Variant) -> (f64, f64)

Maps from a 1D value to an approximate 2D coordinate, using the closest approachable limit of the Hilbert curve. Recommended for real-valued calculations.

Given a value h, this method calculates an approximation of it’s corresponding limit point (x, y), in the Hilbert curve of the highest achievable order for the target platform.

The value of h must be in the range 0.0 <= h < 1.0. A value h >= 1.0 can be given, but functionally, it will be clipped to the closest value to one possible. The coordinates returned will be in the range 0.0 <= x/y < 1.0.

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

Internally, this method uses h2xy_discrete for the calculation, coupled with a trick using the fractional parts of binary/quaternary numbers. In short, the precision of the calculation, as well as the closest approximation possible, both depend on the number of bits in a usize for the target platform. See h2xy_discrete for more details.

Examples

Basic usage:

use hilbert_2d::{h2xy_continuous_f64, Variant};

// In the traditional pattern, the edges of the Hilbert curve are horizontally distant...
let (x_a, _) = h2xy_continuous_f64(0.0, Variant::Hilbert);
let (x_b, _) = h2xy_continuous_f64(1.0, Variant::Hilbert);
assert!(x_b - x_a > 0.999);

// ...but in the Moore pattern, the edges of the curve close up.
let (x_a, _) = h2xy_continuous_f64(0.0, Variant::Moore);
let (x_b, _) = h2xy_continuous_f64(1.0, Variant::Moore);
assert!(x_b - x_a < 0.001);