private void computeEdgeRefs(DDEdge edge, RefGroup rg, int level, int dist) {
if (!edge.isDistanceKnown(level)) return;
int distance = edge.getDistance(level);
if (distance < 0) distance = -distance;
if (distance > dist) return;
long[] ddinfo = edge.getDDInfo();
for (int k = 0; k < ddinfo.length; k++)
if ((k != level)
&& DDInfo.isDistanceKnown(ddinfo[k])
&& (DDInfo.getDistance(ddinfo[k]) != 0)) {
rg.add(edge);
break;
}
}
