+ vector<Real> solutions;
+
+ // Possible solutions are:
+ // t = 0 or 1, or...
+ solutions.push_back (0);
+ solutions.push_back (1);
+
+ // t is a critical point for the other-axis polynomial, or...
+ Polynomial p_prime (polynomial (other));
+ p_prime.differentiate ();
+ vector<Real> criticals = p_prime.solve ();
+ solutions.insert (solutions.end (), criticals.begin (), criticals.end ());
+
+ // t solves curve_coordinate(t, X_AXIS) = l or r.