public SearchResult GetBestMove(SearchArgs settings)
{
return(search.GetBestMove(Board, settings));
}
public void AnalyzePosition(Position position, int depth, string file)
{
Semaphore s = new Semaphore(1, 1);
using (StreamWriter w = new StreamWriter(file, false))
{
w.WriteLine("Last Move,Best Move,Move Score,Primary Variation,Depth,Evaluations,Seconds");
}
// Create a list of positions so we can process in parallel
List <Position> positions = new List <Position>();
positions.Add(position);
foreach (Move move in position.GetValidMoves())
{
Position copy = position.Clone();
copy.MakeMove(move);
positions.Add(copy);
}
// Create a list of actions to run in parallel
List <Action> actions = new List <Action>();
foreach (Position p in positions)
{
actions.Add(() =>
{
Stopwatch timer = Stopwatch.StartNew();
Search search = new Search();
SearchArgs args = new SearchArgs(depth, -1, false);
SearchResult best = search.GetBestMove(p, args);
timer.Stop();
s.WaitOne();
using (StreamWriter w = new StreamWriter(file, true))
{
string history = "";
if (!string.IsNullOrEmpty(p.MovesHistory))
{
string move = p.MovesHistory;
if (move.Contains(" "))
{
move = move.Split(' ')[0];
}
history = "After " + move;
}
else
{
history = "Starting Position";
}
w.WriteLine(history + "," + best.BestMove.ToString() + "," + best.Score + "," + best.PrimaryVariation + "," + depth + "," + best.Evaluations + "," + (timer.ElapsedMilliseconds / 1000.0).ToString("0.000"));
}
s.Release();
});
}
// Analyze all positions in parallel
actions.ForEach(a => Task.Run(a));
}
public SearchResult GetBestMove(Position position, SearchArgs settings)
{
SearchResult result = new SearchResult();
initiatingPlayer = position.PlayerToMove;
timer = Stopwatch.StartNew();
cutoff = false;
evaluations = 0;
hashLookups = 0;
useCache = settings.EnableCaching;
timeLimitMilliseconds = settings.MaxSeconds < 0 ? long.MaxValue : settings.MaxSeconds * 1000;
List <Move> moves = null;
List <int> depths = new List <int>();
// Instead of creating some complicated for loop, just store up the depths we intend to search ahead of time
if (settings.MaxSeconds < 0)
{
if (settings.MaxDepth != 1)
{
// If we're searching deeper than 3 (6 half moves) then do a fast two level deep search to help with move ordering
depths.Add(4);
}
else if (settings.MaxDepth > 1)
{
// If we're searching deeper than 1 (2 half moves) then do a super fast one level deep search to help with move ordering
depths.Add(2);
}
depths.Add(settings.MaxDepth * 2);
}
else
{
// All the depths we intend to search, in order
for (int depth = 2; depth <= settings.MaxDepth * 2; depth += 2)
{
depths.Add(depth);
}
}
// Iterative deepening
// Increment depth by 2 since we always want to consider pairs of move (our move and opponent's move)
foreach (int depth in depths)
{
// Need to re-initialize hash table at each depth
hashtable = new Dictionary <ulong, SearchResult>();
currentDepth = depth;
SearchResult nextDepth = AlphaBetaSearch(position, int.MinValue, int.MaxValue, depth, 1, 1, ref moves);
// Move ordering for next iteration
if (initiatingPlayer == Player.Red)
{
moves.Sort((c, n) => c.Evaluation.CompareTo(n.Evaluation));
}
else
{
moves.Sort((c, n) => n.Evaluation.CompareTo(c.Evaluation));
}
if (!cutoff)
{
result = nextDepth;
}
}
result.Evaluations = evaluations;
result.HashLookups = hashLookups;
return(result);
}