Example #1
0
  /*
   * Helper for A*
   * Finds passable neighbors for any tile
   */
  private static Set<Node> passableNeighbors(
      Node[][] board, Node t, Master m, Iterable<? extends Sprite> spriteSet) {
    Set<Node> neighs = new HashSet<Node>();
    Vec2i loc = t.getCoords();
    for (int i = -1; i < 2; i++) {
      for (int j = -1; j < 2; j++) {
        if (j == i || (j != 0 && i != 0)) {
          continue;
        } else if (loc.x + i >= 0
            && loc.x + i < board[0].length
            && loc.y + j >= 0
            && loc.y + j < board.length
            && !board[(loc.x + i)][(loc.y + j)].impassible()) {
          neighs.add(board[loc.x + i][loc.y + j]);
        }
      }
    }

    for (Sprite s : spriteSet) {
      if (s.getPlayer() != m.whoseTurn()
          && neighs.contains(board[s.getLocation().y][s.getLocation().x])) {
        neighs.remove(board[s.getLocation().y][s.getLocation().x]);
      }
    }

    return neighs;
  }
Example #2
0
  /**
   * A* implementation over Tile graph
   *
   * @param start : coordinates of start
   * @param fin : coordinates of end
   * @return LinkedList<Tile> representing path
   */
  private static LinkedList<? extends Node> getPath(
      Node[][] board, Vec2i start, Vec2i fin, Master m, Iterable<? extends Sprite> spriteSet) {
    LinkedList<Node> path = new LinkedList<Node>();
    PriorityQueue<Node> open = new PriorityQueue<Node>();
    open.add(board[start.x][start.y]);
    HashSet<Node> done = new HashSet<Node>();
    if (board[fin.x][fin.y].impassible()) {
      return null;
    }
    for (Sprite s : spriteSet) {
      if (s.getPlayer() == m.whoseTurn() && s.getLocation().equals(new Vec2i(fin.y, fin.x))) {
        return null;
      }
    }

    board[start.x][start.y].setDistance(0);
    while (!open.isEmpty()) {
      Node curr = open.poll();
      if (fin.x == curr.getCoords().x && fin.y == curr.getCoords().y) {
        Node t = curr;
        while (t.getPrev() != null) {
          path.addFirst(t);
          t = t.getPrev();
        }

        return path;
      }

      done.add(curr);

      for (Node neigh : Pathfinding.passableNeighbors(board, curr, m, spriteSet)) {
        if (done.contains(neigh)) {
          continue;
        }

        if (neigh.getDistance() > curr.getDistance() + 1) {
          neigh.setDistance(curr.getDistance() + 1);
          neigh.setPrev(curr);
          neigh.setEstimate(board[fin.x][fin.y]);
        }
        open.add(neigh);
      }
    }
    return null;
  }