be-graphes/be-graphes-algos/src/main/java/org/insa/graphs/algorithm/shortestpath/AStarAlgorithm.java

package org.insa.graphs.algorithm.shortestpath;

import org.insa.graphs.algorithm.AbstractInputData.Mode;
import org.insa.graphs.model.Node;
import org.insa.graphs.model.Point;

public class AStarAlgorithm extends DijkstraAlgorithm {

    Node arrivee;
    Mode mode;
    double max_speed;

    class LabelStar extends Label {

        Node arrivee;
        double heuristiqueArrive;

        public LabelStar(Node sommet_courant, Node pere, double cout, Node arrivee) {
            super(sommet_courant, pere, cout);
            this.arrivee = arrivee;

            switch (mode) {
                case TIME:
                    this.heuristiqueArrive = this.sommet_courant.getPoint().distanceTo(arrivee.getPoint()) / max_speed;
                    break;
                case LENGTH:
                    this.heuristiqueArrive = Point.distance(super.sommet_courant.getPoint(), arrivee.getPoint());
                    break;
            }
        }

        @Override
        public int compareTo(Label other) throws IllegalArgumentException {
            return Double.compare(
                this.cout + heuristiqueArrive, 
                other.cout + ((LabelStar)other).heuristiqueArrive);
        }
    }

    public AStarAlgorithm(ShortestPathData data) {
        super(data);
        this.arrivee = data.getDestination();
        this.mode = data.getMode();
        this.max_speed = (double) data.getMaximumSpeed()/3.6;
        if (this.max_speed < 0){
            this.max_speed = (double) data.getGraph().getGraphInformation().getMaximumSpeed() / 3.6;                
        }
    }

    @Override
    public Label createLabel(Node n) {
        return new LabelStar(n, null, Float.MAX_VALUE, arrivee);
    }

    public Label createLabel(Node n, double cout) {
        return new LabelStar(n, null, cout, arrivee);
    }
}