struct PK_TOPOL_fctab_normal_vec_s
       {
       PK_VECTOR_t *vec;
       int       length;
       };
typedef struct PK_TOPOL_fctab_normal_vec_s  PK_TOPOL_fctab_normal_vec_t;


This is a support structure for PK_TOPOL_facet_r_t.
It represents a one column table of vertex normals.