Function polygon_to_polygon_distance

nodedb-spatial/src/predicates/distance.rs:212–247

(ra: &[Vec<[f64; 2]>], rb: &[Vec<[f64; 2]>])

}

fn polygon_to_polygon_distance(ra: &[Vec<[f64; 2]>], rb: &[Vec<[f64; 2]>]) -> f64 {
    let Some(ext_a) = ra.first() else {
        return f64::INFINITY;
    };
    let Some(ext_b) = rb.first() else {
        return f64::INFINITY;
    };

    // If any vertex of B is inside A (or vice versa), distance is 0.
    for pt in ext_b {
        if point_in_polygon(pt[0], pt[1], ext_a) || point_on_ring_boundary(*pt, ext_a) {
            return 0.0;
        }
    }
    for pt in ext_a {
        if point_in_polygon(pt[0], pt[1], ext_b) || point_on_ring_boundary(*pt, ext_b) {
            return 0.0;
        }
    }

    // Min edge-to-edge distance.
    let mut min_dist = f64::INFINITY;
    let a_edges = ring_edges(ext_a);
    let b_edges = ring_edges(ext_b);
    for &(a1, a2) in &a_edges {
        for &(b1, b2) in &b_edges {
            let d_sq = segment_to_segment_dist_sq(a1, a2, b1, b2);
            if d_sq < 1e-20 {
                return 0.0;
            }
            let d = coord_dist_to_meters(d_sq.sqrt(), a1, b1);
            min_dist = min_dist.min(d);
        }
    }
    min_dist
}

/// Point to segment distance in meters.
///