function circle_point(c, r, alpha) = [ c[0] + r * cos(alpha),
c[1] + r * sin(alpha) ];
-function tangent_intersect(a,c,r) =
#define d (dist(a,c))
#define alpha (atan2(a[1]-c[1],a[0]-c[0]))
#define gamma (asin(r / d))
#define beta (alpha + 90 - gamma)
+
+function tangent_intersect_beta(c,r,a) =
+ beta;
+
+function tangent_intersect_b(c,r,a) =
circle_point(c, r, beta);
#undef d
#undef alpha
#undef gamma
#undef beta
+
+function reflect_in_y(p) = [-p[0], p[1]];
+