struct PK_TOPOL_fctab_vertex_normal_s
       {
       int        *normal;
       int        length;
       };
typedef struct PK_TOPOL_fctab_vertex_normal_s
               PK_TOPOL_fctab_vertex_normal_t;


This is a support structure for PK_TOPOL_facet_r_t. It structure represents a
one column table which maps vertex indices (topology) into a table of 'normal'
indices.