/* we are interested in the angle subtended at the rim, from the
* rim's point of view. */
K distance[k]= vertices[v][k] - oncircle[k];
- double distance_positive_z= distance[3];
+ double distance_positive_z= distance[2];
double distance_radial_outwards= dotprod(distance, oncircle);
rim_vertex_angles[v]= atan2(distance_positive_z, distance_radial_outwards);
}