PK_MESH_facet_t   

struct PK_MESH_facet_s
    {
    PK_MESH_facet_type_t           facet_type; --- The type of facet data
                                               --- being conveyed
    union
        {
        PK_MESH_facet_index_t     *index;
        PK_MESH_facet_strip_t     *strip;
        PK_MESH_facet_fan_t       *fan;
        PK_MESH_facet_vector_t    *vector;
        }
                                   facet;      --- Data
    };
typedef struct PK_MESH_facet_s PK_MESH_facet_t;

Used in:

PK_MESH_facet_cb_f_t
PK_MESH_facet_f