PK_ERROR_code_t      PK_EDGE_is_planar
(
--- received arguments ---
PK_EDGE_t            edge,       --- edge
PK_LOGICAL_t         want_plane, --- whether plane is wanted

--- returned arguments ---
PK_LOGICAL_t *const is_planar,   --- whether edge is planar
PK_PLANE_t   *const plane        --- plane if is_planar and want_plane
                                 --- otherwise PK_ENTITY_null
)


This function detects whether an edge lies in a plane.


Specific Errors:
    PK_ERROR_missing_geom           edge has no curve


is_planar is returned as PK_LOGICAL_true if the function detects that the
edge lies in a plane, otherwise it is returned as PK_LOGICAL_false.  If the
application sets want_plane to PK_LOGICAL_true and is_planar is
PK_LOGICAL_true, then Parasolid will also return a plane in which the edge
lies.  The plane will be orphan geometry of the current partition.
If want_plane is PK_LOGICAL_false or is_planar is PK_LOGICAL_false then
plane will be returned as PK_ENTITY_null.

Parasolid will not claim that an edge is planar if it is not, but it is not
guaranteed to detect that an edge is planar even if it is.