private JPSNode[] getJPSNeighbours(JPSNode current, List<IObstacle> obsList) {
double x = current.getX();
double y = current.getY();
LinkedList<JPSNode> nodes = new LinkedList<JPSNode>();
JPSNode parent = current.came_from;
if (parent != null) { // determines whether to prune neighbors
JPSNode norm = normalizeDirection(x, y, parent.getX(), parent.getY());
double dx = norm.getX() * coordinateScaling;
double dy = norm.getY() * coordinateScaling;
JPSNode temp = new JPSNode(current);
if (((int) dx & (int) dy) != 0) { // diagonal direction
// check straight directions in the direction of the diagonal move
if (walkable(temp.setPosition(x, y + dy))) nodes.add(new JPSNode(temp));
if (walkable(temp.setPosition(x + dx, y))) nodes.add(new JPSNode(temp));
if (walkable(temp.setPosition(x + dx, y + dy))) nodes.add(new JPSNode(temp));
// forced neighbor checks
if (!walkable(temp.setPosition(x - dx, y))) nodes.add(new JPSNode(temp.shift(0, dy)));
if (!walkable(temp.setPosition(x, y - dy))) nodes.add(new JPSNode(temp.shift(dx, 0)));
} else { // straight direction
if (walkable(temp.setPosition(x + dx, y + dy))) {
nodes.add(new JPSNode(temp));
// forced neighbor checks
if (!walkable(temp.setPosition(x + dy, y + dx)))
nodes.add(new JPSNode(temp.shift(dx, dy)));
if (!walkable(temp.setPosition(x - dy, y - dx)))
nodes.add(new JPSNode(temp.shift(dx, dy)));
}
}
} else {
// no parent, return all that aren't blocked
JPSNode[] ns =
new JPSNode[] {
new JPSNode(x, y - coordinateScaling),
new JPSNode(x + coordinateScaling, y - coordinateScaling),
new JPSNode(x + coordinateScaling, y),
new JPSNode(x + coordinateScaling, y + coordinateScaling),
new JPSNode(x, y + coordinateScaling),
new JPSNode(x - coordinateScaling, y + coordinateScaling),
new JPSNode(x - coordinateScaling, y),
new JPSNode(x - coordinateScaling, y - coordinateScaling)
};
for (int i = 0; i < ns.length; i++) {
if (walkable(ns[i])) nodes.add(ns[i]);
}
}
return nodes.toArray(new JPSNode[nodes.size()]);
}
