AlgoTangentCurve(Construction cons, String label, GeoPoint P, GeoCurveCartesian f) {
super(cons);
this.P = P;
this.f = f;
tangent = new GeoLine(cons);
// check if P is defined as a point of the curve's graph
pointOnCurve = false;
if (P.getParentAlgorithm() instanceof AlgoPointOnPath) {
AlgoPointOnPath algo = (AlgoPointOnPath) P.getParentAlgorithm();
pointOnCurve = algo.getPath() == f;
}
if (pointOnCurve) T = P;
else T = new GeoPoint(cons);
tangent.setStartPoint(T);
// First derivative of curve f
AlgoDerivative algo = new AlgoDerivative(cons, f);
this.df = (GeoCurveCartesian) algo.getDerivative();
cons.removeFromConstructionList(algo);
setInputOutput(); // for AlgoElement
compute();
tangent.setLabel(label);
}
