Function block_connection_matrix 

pub fn block_connection_matrix(
    blocks: &[Block],
    outer_faces: &[FaceRecord],
    tol: Float,
    options: BlockConnectionOptions,
) -> (Vec<Vec<i8>>, Vec<Vec<i8>>, Vec<Vec<i8>>, Vec<Vec<i8>>)

Connectivity matrices describing which faces touch between blocks.

Arguments

• blocks - Original block list.
• outer_faces - Optional pre-computed outer faces (face records).
• tol - Compatibility parameter maintained for parity with Python (unused).
• options - Node matching thresholds and sampling strides.

Returns

Four symmetric adjacency matrices for overall connectivity and each axis-specific match.