Function compute_orientation 

pub fn compute_orientation(
    entity_type: ReferenceCellType,
    vertices: &[usize],
) -> i32

Compute a 32-bit integer that encodes the orientation differences between the reference cell and a cell with vertices numbered as input

From right to left, the bits of this function’s output encode:

• 1 bit for each edge - set to 1 if the edge needs reversing
• 3 bits for each face - two rightmost bits encode number of rotations that need to be applied to face; left bit encodes whether it needs reflecting