static int gen_torus(struct mesh *mesh, float rad, float ringrad, int usub, int vsub);
static void zsort(struct mesh *m);
static void draw_lowres_raster(void);
static int gen_torus(struct mesh *mesh, float rad, float ringrad, int usub, int vsub);
static void zsort(struct mesh *m);
static void draw_lowres_raster(void);