fn splice_hops(points: &[Pos2], crossings: &[Crossing]) -> Vec<Pos2>Expand description
Splice a small flat-topped bump into points at each crossing that lies on
an axis-aligned run: two 45° segments with a flat top, bulging perpendicular
to the run (up for a horizontal wire, right for a vertical one). Diagonal
chamfer runs never match a crossing and pass through untouched.