public Direction BestMove(Location location, Direction currentDirection, IEnumerable <Ghost> ghosts)
{
if (_lastX == location.CellX && _lastY == location.CellY)
{
return(currentDirection);
}
_lastX = location.CellX;
_lastY = location.CellY;
// Get the distance to each cell
var x = Math.Min(Math.Max(0, location.CellX), _aiMap.Width - 1);
var y = Math.Min(Math.Max(0, location.CellY), _aiMap.Height - 1);
_aiMap.CalcDistance(x, y);
// Find the closest pill
var cell = _aiMap.ClosestPill();
// Find the closest frightened ghost
var frightenedDistances = ghosts.Where(g => g.Frightened)
.Select(g => new GhostDistance(g, _aiMap.Cell(g.Location.CellX, g.Location.CellY).Distance))
.OrderBy(gd => gd.Distance).ToList();
// Change direction if there is one and it's a short distance away
if (frightenedDistances.Count > 0 && frightenedDistances[0].Distance < 8)
{
cell = _aiMap.Cell(frightenedDistances[0].Ghost.Location.CellX,
frightenedDistances[0].Ghost.Location.CellY);
}
// Get list of available moves
var pacMan = _aiMap.Cell(location.CellX, location.CellY);
var moves = new[] { Direction.Up, Direction.Down, Direction.Left, Direction.Right }
.Where(d => pacMan.CellInDirection(d).IsPlayArea)
.ToList();
if (_counter > 0)
{
_counter--;
}
if (moves.Count > 1 && _counter > 0)
{
// Don't swap back on self if moved recently
moves.Remove(currentDirection.Opposite());
}
// Work out which direction the pill/firghtened ghost is in
var idealDirection = _aiMap.WorkBackTo(cell.X, cell.Y, x, y);
// Get the distances of each alive ghost
var ghostDistances = ghosts.Where(AvoidGhost)
.Select(g => new GhostDistance(g, _aiMap.Cell(g.Location.CellX, g.Location.CellY).Distance))
.OrderBy(gd => gd.Distance);
// Avoid the direction of the ghost
foreach (var ghostDistance in ghostDistances.Where(g => g.Distance < 11))
{
var nextTarget = ghostDistance.Ghost.NextTarget;
var nextDistance = _aiMap.Cell(nextTarget.CellX, nextTarget.CellY).Distance;
// Check if ghost is moving closer or is very close
if (nextDistance < ghostDistance.Distance || ghostDistance.Distance < 11)
{
var ghostDirection = _aiMap.WorkBackTo(ghostDistance.Ghost.Location.CellX,
ghostDistance.Ghost.Location.CellY, x, y);
if (moves.Contains(ghostDirection) && moves.Count > 1)
{
moves.Remove(ghostDirection);
}
}
}
// Go in direction of pill if safe
var bestDirection = moves.Contains(idealDirection) ? idealDirection : moves[0];
if (bestDirection != _last)
{
_counter = 2;
}
_last = bestDirection;
return(bestDirection);
}
public AiMapCell CellInDirection(Direction direction) => _map.Cell(X + direction.Dx(), Y + direction.Dy());
