Update points_lines_vectors.cpp

2020-06-24 11:27:41 -05:00 · 2020-06-24 11:27:41 -05:00 · 53d3373f17
commit 53d3373f17
parent b49b694fa8
1 changed files with 1 additions and 0 deletions
--- a/Geometry/points_lines_vectors.cpp
+++ b/Geometry/points_lines_vectors.cpp
@ -27,6 +27,7 @@ double angle(point a, point o, point b) {
 	return acos(dot(oa, ob) / sqrt(norm_sq(oa) * norm_sq(ob)));
 }

+// (q.x - p.x) * (r.y - p.y) - (r.x - p.x) * (q.y - p.y)
 bool ccw(point p, point q, point r) { return cross(vec(p, q), vec(p, r)) > 0; }

 struct line {