pub fn join_centered_multibonds(bonds: &mut [DrawnBond])Expand description
Mitre acyclic doubles and triples to their single-bond neighbors.
Each parallel stroke is an infinite line; each neighboring single is another. Junction ends are line–line intersections (no fixed-length stubs), so acute and obtuse angles both close cleanly.
One single: extend it to the far parallel line; both multiple-bond strokes stop on that single.
Two singles: leave them meeting at the atom; extend each multiple-bond stroke past the atom until its end lies on a single (closes the vertex angle gap).