typedef struct
    {
    PK_VECTOR_t         direction;        --- taper direction
    double              angle;            --- taper angle (radian)
    int                 n_refs;           --- number of reference entities
    const PK_ENTITY_t  *references;       --- taper reference entities
    } PK_FACE_change_data_taper_t;


Parameters of change operation taper. For more details about the signification
of these parameters, please see PK_FACE_taper.


Description of fields:



direction              Taper direction.


angle                  Taper angle (in radians).


n_refs                 Size the references array.


references             Array of the taper reference entities
                         (cf PK_FACE_taper).