public static List <Entity> AdjacentHostiles(EncounterState state, FactionName parentFaction, EncounterPosition position) { var adjacentHostiles = new List <Entity>(); foreach (var newpos in state.AdjacentPositions(position)) { adjacentHostiles.AddRange(AIUtils.HostilesInPosition(state, parentFaction, newpos.X, newpos.Y)); } return(adjacentHostiles); }
// PERF: If this ends up being slow, we can mark with a dirty bit /** * Returns a path from start to end, exclusive - that is, the start and end nodes are *not* listed in the path. Does a full * naive search every time. */ public static List <EncounterPosition> AStarWithNewGrid( EncounterPosition start, EncounterPosition end, EncounterState state, int maxAreaToExplore = 950 ) { SimplePriorityQueue <EncounterPosition> frontier = new SimplePriorityQueue <EncounterPosition>(); frontier.Enqueue(start, 0f); var cameFrom = new Dictionary <EncounterPosition, EncounterPosition>(); var costSoFar = new Dictionary <EncounterPosition, float>(); costSoFar[start] = 0f; while (frontier.Count > 0 && cameFrom.Count < maxAreaToExplore) { var currentPosition = frontier.Dequeue(); var adjacentPositions = state.AdjacentPositions(currentPosition); if (adjacentPositions.Contains(end)) { var path = new List <EncounterPosition>() { currentPosition }; EncounterPosition cameFromPos; while (cameFrom.TryGetValue(path[path.Count - 1], out cameFromPos) && (cameFromPos != start)) { path.Add(cameFromPos); } path.Reverse(); return(path); } var adjacentUnblocked = adjacentPositions.Where(adjacent => !state.IsPositionBlocked(adjacent)).ToList(); adjacentUnblocked.ForEach(adjacent => { var newNextPositionCost = costSoFar[currentPosition] + 1f; if (!costSoFar.ContainsKey(adjacent) || newNextPositionCost < costSoFar[adjacent]) { costSoFar[adjacent] = newNextPositionCost; // Uses straight-line distance as heuristic float priority = newNextPositionCost + adjacent.DistanceTo(end); frontier.Enqueue(adjacent, priority); cameFrom[adjacent] = currentPosition; } }); } return(null); }