public AStar(ArrayList<ASPoint> invalid, int width, int height, ASPoint start, ASPoint finish, boolean details, int riverID) {
		this.width = width;
		this.height = height;
		this.finish = finish;
		this.start = start;
		this.details = details;
		this.riverID = riverID;
		
		//Remember which tiles are unpassable.
		fillInvalidNodes(invalid);
	}