public AlgoDirectrix(Construction cons, String label, GeoConic c) {
super(cons);
this.c = c;
eigenvec = c.eigenvec;
b = c.b;
directrix = new GeoLine(cons);
P = new GeoPoint(cons);
directrix.setStartPoint(P);
setInputOutput(); // for AlgoElement
compute();
directrix.setLabel(label);
}
public AlgoTangentFunctionPoint(Construction cons, String label, GeoPoint2 P, GeoFunction f) {
this(cons, P, f);
tangent.setLabel(label);
}