geo-repair 0.13.0

Fix invalid GIS geometries in parallel using rewritten GEOS/JTS repair module
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44

//! Shared utility functions used across the crate.

use geo::Coord;

pub(crate) fn shoelace_sum(ring: &[Coord<f64>]) -> f64 {
    let mut sum = 0.0;
    for window in ring.windows(2) {
        sum += window[0].x * window[1].y - window[1].x * window[0].y;
    }
    sum
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_shoelace_sum_ccw() {
        let ring = vec![
            Coord { x: 0.0, y: 0.0 },
            Coord { x: 1.0, y: 0.0 },
            Coord { x: 1.0, y: 1.0 },
            Coord { x: 0.0, y: 1.0 },
            Coord { x: 0.0, y: 0.0 },
        ];
        let sum = shoelace_sum(&ring);
        assert!(sum > 0.0);
        assert!((sum - 2.0).abs() < 1e-12);
    }

    #[test]
    fn test_shoelace_sum_cw() {
        let ring = vec![
            Coord { x: 0.0, y: 0.0 },
            Coord { x: 0.0, y: 1.0 },
            Coord { x: 1.0, y: 1.0 },
            Coord { x: 1.0, y: 0.0 },
            Coord { x: 0.0, y: 0.0 },
        ];
        let sum = shoelace_sum(&ring);
        assert!(sum < 0.0);
        assert!((sum + 2.0).abs() < 1e-12);
    }
}