struct PK_FACE_change_replace_o_s
    {
    int                   o_t_version;  --- version number of option structure
    PK_replace_merge_t    merge;        --- whether changed faces are to be
                                        --- merged with their neighbours if
                                        --- feasible (PK_replace_merge_no_c)
    };
typedef struct PK_FACE_change_replace_o_s PK_FACE_change_replace_o_t;


This structure contains replace-surface-specific optional controls for
PK_FACE_change


Description of fields:


merge     Adjacent faces may become mergeable when the surface of one or
            both faces is replaced.  Permitted values are:

            PK_replace_merge_no_c
            PK_replace_merge_in_c
            PK_replace_merge_out_c

            The default value is PK_replace_merge_no_c