PK_ERROR_code_t  PK_LOOP_euler_make_edge_loop
(
--- received arguments ---
PK_LOOP_t        loop,      --- Loop of face
PK_FIN_t         fin1,      --- Fin at first vertex to join
PK_FIN_t         fin2,      --- Fin at second vertex to join

--- returned arguments ---
PK_LOOP_t *const new_loop   --- New loop created
)


This function joins two vertices in the same loop of a face, creating a new
loop.


Specific Errors:
    PK_ERROR_fin_not_in_loop    One of the fins is not in loop
    PK_ERROR_edge_is_ring       There are no vertices in loop


loop may be isolated in which case fin1 and fin2 must be PK_ENTITY_null.
Otherwise the forward fin of fin1 will be a fin of the new edge.  new_loop
will be on the right of the new edge.

The new edge will not have any geometry attached and therefore the
result of this operation will be an invalid body.

The inverse of this function is PK_EDGE_euler_delete_with_loop.