DESCRIPTION:

Change visibility bits for the tristrip.
Currently the following bits are allocted:
0x0001: Lines in front of other elements
0x0002: Lines behind other elements
0x0004: The tristrip label (located at first vertex)
0x0008: Fill triangles, if in front of other elements
0x0010: Fill even if behind
0x0020: Fill with shading (otherwise fill is flat)
0x0040: Cull front sides
0x0080: Cull back sides
0x0100: Use gouraud shading, if normal data is available.
0x0200: Use alpha channel as given in TRISTRIP_ALPHA.