4 #define dsq(i) (a[i]-b[i])*(a[i]-b[i])
8 function circle_point(c, r, alpha) = [ c[0] + r * cos(alpha),
9 c[1] + r * sin(alpha) ];
12 #define alpha (atan2(a[1]-c[1],a[0]-c[0]))
13 #define gamma (asin(r / d))
14 #define beta (alpha + 90 - gamma)
16 function tangent_intersect_beta(c,r,a) =
19 function tangent_intersect_b(c,r,a) =
20 circle_point(c, r, beta);
26 function reflect_in_y(p) = [-p[0], p[1]];