+/*
+ * Compute the fastest distance and angle speeds matching the radius
+ * from current traj_speed
+ */
+/* static */void circle_get_da_speed_from_radius(struct trajectory *traj,
+ double radius_mm,
+ double *speed_d,
+ double *speed_a)
+{
+ /* speed_d = coef * speed_a */
+ double coef;
+ double speed_d2, speed_a2;
+
+ coef = 2. * radius_mm / traj->position->phys.track_mm;
+
+ speed_d2 = traj->a_speed * coef;
+ if (speed_d2 < traj->d_speed) {
+ *speed_d = speed_d2;
+ *speed_a = traj->a_speed;
+ }
+ else {
+ speed_a2 = traj->d_speed / coef;
+ *speed_d = traj->d_speed;
+ *speed_a = speed_a2;
+ }
+}
+