static int unit_gear (ModeInfo *, GLfloat color[4]);
static int draw_ground (ModeInfo *, GLfloat color[4]);
static void init_walker (ModeInfo *, walker *);
static int unit_gear (ModeInfo *, GLfloat color[4]);
static int draw_ground (ModeInfo *, GLfloat color[4]);
static void init_walker (ModeInfo *, walker *);