9 pts2line(const point_t *p1, const point_t *p2, line_t *l);
12 proj_pt_line(const point_t * p, const line_t * l, point_t * p_out);
15 intersect_line(const line_t *l1, const line_t *l2, point_t *p);
18 intersect_segment(const point_t *s1, const point_t *s2,
19 const point_t *t1, const point_t *t2,