void polyfill_flat(struct pvertex *v, int vnum, unsigned char col);
int clip_line(int *x0, int *y0, int *x1, int *y1, int xmin, int ymin, int xmax, int ymax);
void polyfill_flat(struct pvertex *v, int vnum, unsigned char col);
int clip_line(int *x0, int *y0, int *x1, int *y1, int xmin, int ymin, int xmax, int ymax);