Function intersect

code/geometry/circles.cpp:2–11

#include "lines.cpp"
int intersect(C(A, rA), C(B, rB), point &r1, point &r2) {
  double d = abs(B - A);
  if ((rA + rB) <  (d - EPS) || d < abs(rA - rB) - EPS)
    return 0;
  double a = (rA*rA - rB*rB + d*d) / 2 / d,
         h = sqrt(rA*rA - a*a);
  point v = normalize(B - A, a),
        u = normalize(rotate(B-A), h);
  r1 = A + v + u, r2 = A + v - u;
  return 1 + (abs(u) >= EPS); }
int intersect(L(A, B), C(O, r), point &r1, point &r2) {
  point H = proj(B-A, O-A) + A; double h = abs(H-O);
  if (r < h - EPS) return 0;