/// <summary>
/// 목적지에서 가까운 갈수있는 타일을 찾는다.
/// </summary>
/// <param name="unit">목적지에 가는 주체</param>
/// <param name="dest">목적지</param>
/// <returns></returns>
public static Tile GetClosestReachableDest(Unit unit, Vector2Int dest)
{
Tile curTile = FieldManager.GetTileClamp(dest);
List <Tile> frontier = new List <Tile>()
{
curTile
};
List <Tile> visited = new List <Tile>();
Vector2Int [] directions = { Vector2Int.up, Vector2Int.down, Vector2Int.right, Vector2Int.left };
int loop_count = 0;
while (true)
{
InfiniteLoopDebug.Run("Pathfind", "GetClosestReachableDest", 140);
// 무한루프 방지용
loop_count++;
if (frontier.Count == 0 || loop_count > 1000)
{
Debug.Log("갈수 없거나 계산이 너무 오래걸립니다!");
return(null);
}
curTile = frontier[0];
visited.Add(curTile);
frontier.RemoveAt(0);
// if (curTile.IsPositionable(unit))
if (PathFindAlgorithm(/*unit,*/ unit.MoveSkill, unit.Position, curTile.position) != null)
{
return(curTile);
}
foreach (Vector2Int direction in directions)
{
Tile tile = FieldManager.GetTile(curTile.position + direction);
if (tile != null && !visited.Contains(tile))
{
frontier.Add(tile);
}
}
}
}
/// <summary>
/// 유닛의 이동경로를 찾는 알고리즘.
/// </summary>
/// <param name="unit">이동 유닛</param>
/// <param name="from">출발 위치</param>
/// <param name="to">도착 위치</param>
/// <returns></returns>
public static List <Vector2Int> PathFindAlgorithm(Model.Unit agent, Vector2Int from, Vector2Int to)
{
if (FieldManager.GetTile(to) == null || FieldManager.GetTile(to).HasUnit())
{
Debug.LogWarning("길찾기 알고리즘 오류");
return(null);
}
Node node = new Node(from, to);
List <Node> frontier = new List <Node>(); // priority queue ordered by Path-Cost, with node as the only element
List <Node> explored = new List <Node>(); // an empty set
frontier.Add(node);
while (true)
{
InfiniteLoopDebug.Run("Pathfind", "GetClosestReachableDest", 258);
if (frontier.Count == 0)
{
Debug.Log("목적지에 갈수 있는 길이 존재하지 않습니다.");
return(null); // 답이 없음.
}
node = Node.PopSmallestCostNode(frontier);
frontier.Remove(node);
if (node.unitPosition.Equals(to)) // goal test
{
return(Node.RebuildPath(node));
}
explored.Add(node); // add node.State to explored
foreach (var child in Node.GetAvilableNeighbor(agent, node))
{
bool isExplored = false;
foreach (var item in explored)
{
if (item.unitPosition == child.unitPosition)
{
isExplored = true;
}
}
if (isExplored.Equals(true))
{
continue;
}
bool isFrontiered = false;
for (int i = frontier.Count - 1; i >= 0; i--)
{
if (frontier[i].unitPosition.Equals(child.unitPosition))
{
isFrontiered = true;
if (child.unitPosition == frontier[i].unitPosition &&
child.evaluationCost < frontier[i].evaluationCost)
{
frontier.Remove(frontier[i]);
frontier.Add(child);
}
}
}
if (isFrontiered.Equals(false))
{
frontier.Add(child);
}
}
}
}
