PK_LOOP_ask_vertices

PK_ERROR_code_t     PK_LOOP_ask_vertices
(
--- received arguments ---
PK_LOOP_t           loop,              --- a loop

--- returned arguments ---
int          *const n_vertices,        --- number of vertices (>= 0)
PK_VERTEX_t **const vertices           --- vertices (optional)
)


This function returns an ordered list of vertices around the given loop.


The vertices are returned in the order that they appear moving round
the loop, possibly with repeats.

The output array 'vertices' is optional. If it is set to NULL, the function
will only compute the number of vertices in the loop (counting repeats).