pub fn planar_embedding_data(graph: &Graph) -> Option<PlanarEmbeddingData>Expand description
Build the planar embedding (per-node clockwise neighbour orders) for a
planar graph, mirroring networkx/algorithms/planarity.py’s embedding
phases exactly: sign(e) resolves each edge’s absolute side through the
ref/side chains, the oriented adjacency lists are re-sorted by the
signed nesting depth, the initial ccw chain is laid down per node, and
dfs_embedding then places tree half-edges first and back edges per the
resolved side (rc-planar-embedding-kernel-07rh8, milestone 1). Returns
None for non-planar graphs.
Self-loops are ignored (they do not affect planarity or the rotation).