Example usage for com.badlogic.gdx.utils BinaryHeap BinaryHeap

Introduction

In this page you can find the example usage for com.badlogic.gdx.utils BinaryHeap BinaryHeap.

Prototype

public BinaryHeap() 

Source Link

Usage

From source file:com.vlaaad.dice.game.world.util.AStar.java

License:Open Source License

public static Array<Coordinate> search(World grid, WorldObject startObject, WorldObject endObject,
        boolean near) {
    Node start = Pools.obtain(Node.class).set(startObject.getX(), startObject.getY());
    Node end = Pools.obtain(Node.class).set(endObject.getX(), endObject.getY());
    nodes.put(start.x, start.y, start);/*from   w  ww  . j a  v  a  2  s .  c  o m*/
    nodes.put(end.x, end.y, end);

    BinaryHeap<Node> openHeap = new BinaryHeap<Node>();
    openHeap.add(start);

    List<Node> neighbours = new LinkedList<Node>();
    Node nearNode = null;
    boolean searchNear = true;
    while (openHeap.size > 0) {
        Node current = openHeap.pop();
        int cx = current.x - end.x;
        int cy = current.y - end.y;
        if (cx == 0 && cy == 0) {
            Array<Coordinate> result = new Array<Coordinate>();
            while (current.parent != null) {
                result.add(Coordinate.obtain(current.x, current.y));
                current = current.parent;
            }
            result.reverse();
            cleanUp();
            return result;
        }
        if (near && searchNear && !isValid(grid, end.x, end.y)) {
            nearNode = current;
            if (Math.abs(cx) <= 1 && Math.abs(cy) <= 1) {
                searchNear = false;
            }
        }

        current.closed = true;
        neighbours.clear();
        int gScore = current.g + 1;
        addNeighbours(grid, neighbours, current);
        for (Node neighbour : neighbours) {
            if (neighbour.closed)
                continue;
            if (!neighbour.visited || gScore < neighbour.g) {

                neighbour.parent = current;
                int dx = neighbour.x - end.x;
                int dy = neighbour.y - end.y;
                neighbour.h = (float) (Math.sqrt(dx * dx + dy * dy));
                neighbour.g = gScore;
                neighbour.f = neighbour.g + neighbour.h;
                if (!neighbour.visited) {
                    openHeap.add(neighbour);
                }
                openHeap.setValue(neighbour, neighbour.f);
                neighbour.visited = true;
            }
        }
    }
    if (nearNode != null && !searchNear) {
        Array<Coordinate> result = new Array<Coordinate>();
        while (nearNode.parent != null) {
            result.add(Coordinate.obtain(nearNode.x, nearNode.y));
            nearNode = nearNode.parent;
        }
        result.reverse();
        cleanUp();
        return result;
    }
    cleanUp();
    return null;
}

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