PK_VERTEX_ask_shells

PK_ERROR_code_t    PK_VERTEX_ask_shells
(
--- received arguments ---
PK_VERTEX_t        vertex,            --- a vertex

--- returned arguments ---
int         *const n_shells,          --- number of shells (>= 1)
PK_SHELL_t **const shells             --- shells (optional)
)


This function returns the set of shells at the given vertex.


The output array 'shells' is optional. If it is set to NULL, the function will
only compute the number of shells at the vertex.