Function polygons_intersect

nodedb-spatial/src/predicates/intersects.rs:174–208

Two polygons intersect — edge crossing or containment.

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

/// Two polygons intersect — edge crossing or containment.
fn polygons_intersect(ra: &[Vec<[f64; 2]>], rb: &[Vec<[f64; 2]>]) -> bool {
    let Some(ext_a) = ra.first() else {
        return false;
    };
    let Some(ext_b) = rb.first() else {
        return false;
    };

    // Check if any vertex of B is inside/on A.
    for pt in ext_b {
        if point_intersects_polygon(*pt, ra) {
            return true;
        }
    }

    // Check if any vertex of A is inside/on B.
    for pt in ext_a {
        if point_intersects_polygon(*pt, rb) {
            return true;
        }
    }

    // Check edge crossings between exteriors.
    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 {
            if segments_intersect(a1, a2, b1, b2) {
                return true;
            }
        }
    }

    false
}

#[cfg(test)]
mod tests {