// Returns neighbouring tiles of the parameter tile (N,E,S,W)
public List <BaseTile> GetNeighbours(BaseTile baseTile)
{
var neighbours = new List <BaseTile>();
for (int x = -1; x <= 1; x++)
{
for (int y = -1; y <= 1; y++)
{
if (x == 0 && y == 0)
{
continue;
}
int checkX = baseTile.gridX + x;
int checkY = baseTile.gridY + y;
if (checkX != baseTile.gridX && checkY != baseTile.gridY)
{
continue;
}
if (checkX >= 0 && checkX < BoardSize && checkY >= 0 && checkY < BoardSize)
{
neighbours.Add(tileArray[checkX, checkY]);
}
}
}
return(neighbours);
}
private int GetDistance(BaseTile a, BaseTile b)
{
var dstX = Mathf.Abs(a.gridX - b.gridX);
var dstY = Mathf.Abs(a.gridY - b.gridY);
if (dstX > dstY)
{
return(14 * dstY + 10 * (dstX - dstY));
}
return(14 * dstX + 10 * (dstY - dstX));
}
private List <BaseTile> RetracePath(BaseTile start, BaseTile end)
{
var path = new List <BaseTile>();
var current = end;
while (current != start)
{
path.Add(current);
current = current.parent;
}
path.Reverse();
return(path);
}
public List <BaseTile> FindPath(BaseTile start, BaseTile target)
{
var openSet = new List <BaseTile>();
var closedSet = new HashSet <BaseTile>();
openSet.Add(start);
while (openSet.Count > 0)
{
BaseTile current = openSet[0];
for (var i = 1; i < openSet.Count; i++)
{
if (openSet[i].fCost < current.fCost || openSet[i].fCost == current.fCost && openSet[i].hCost < current.hCost)
{
current = openSet[i];
}
}
openSet.Remove(current);
closedSet.Add(current);
if (current == target)
{
return(RetracePath(start, target));
}
foreach (BaseTile neighbour in boardCalculator.GetNeighbours(current))
{
if (!neighbour.IsWalkable() || closedSet.Contains(neighbour))
{
continue;
}
var newMovementCostToNeighbour = current.gCost + GetDistance(current, neighbour);
if (newMovementCostToNeighbour >= neighbour.gCost && openSet.Contains(neighbour))
{
continue;
}
neighbour.gCost = newMovementCostToNeighbour;
neighbour.hCost = GetDistance(neighbour, target);
neighbour.parent = current;
if (!openSet.Contains(neighbour))
{
openSet.Add(neighbour);
}
}
}
return(null);
}