Module topology_section 

.10d Topology section — half-edge graph + CSR adjacency + connectivity summary serialized as a self-describing section (P2.8).

Layout:

[TopologyMiniHeader: 32 bytes]
[half_edges:  N * 16 bytes  (HalfEdge = 4 × u32)]
[v_offsets:   (V+1) * 4 bytes]
[v_neighbours: N * 4 bytes]
[f_offsets:   (F+1) * 4 bytes]
[f_neighbours: N * 4 bytes]

All arrays are little-endian, 4-byte aligned. The section is deterministic: identical input yields byte-identical output. Per-section CRC-32C is handled by the container’s section-table encoder.

Structs

TopologyMiniHeader

The 32-byte Topology-section mini-header.

TopologySectionData

Decoded topology section data.

Enums

TopologySectionError

Topology-section encode/decode error.

Constants

MAX_HALF_EDGE_COUNT

Maximum half-edge count (bounded by 42MB Sentinel: 42MB / 16B = 2.75M).

TOPOLOGY_MINI_HEADER_SIZE

Mini-header size in bytes.

Functions

decode_topology_section

Decode a .10d Topology section payload.

encode_topology_section

Encode a topology section from a half-edge array.

encoded_len

Compute the encoded byte length for a topology section.