private static void UciGo(string[] tokens)
{
if (TryParse(tokens, "movetime", out int timePerMove))
{
//Fixed move time e.g. 5 Minutes per Move = go movetime 300000
TryParse(tokens, "depth", out int searchDepth, int.MaxValue);
_engine.Go(timePerMove, searchDepth);
}
else if (TryParse(tokens, "btime", out int blackTime) && TryParse(tokens, "wtime", out int whiteTime))
{
//Searching on a budget that may increase at certain intervals
//40 Moves in 5 Minutes = go wtime 300000 btime 300000 movestogo 40
//40 Moves in 5 Minutes, 1 second increment per Move = go wtime 300000 btime 300000 movestogo 40 winc 1000 binc 1000 movestogo 40
//5 Minutes total, no increment (sudden death) = go wtime 300000 btime 300000
TryParse(tokens, "binc", out int blackIncrement);
TryParse(tokens, "winc", out int whiteIncrement);
TryParse(tokens, "movestogo", out int movesToGo, 40); //assuming 30 e.g. spend 1/30th of total budget on the move
TryParse(tokens, "depth", out int searchDepth, int.MaxValue);
_engine.Go(blackTime, whiteTime, blackIncrement, whiteIncrement, movesToGo, searchDepth);
}
else if (TryParse(tokens, "depth", out int searchDepth))
{
_engine.Go(searchDepth);
}
else if (IsDefined(tokens, "infinite"))
{
//Infinite = go infinite
_engine.Go();
}
else
{
Uci.Log("'go' parameters missing or not understood. Stop the search using 'stop'.");
_engine.Go();
}
}
private static void UciPosition(string[] tokens)
{
//position [fen <fenstring> | startpos ] moves <move1> .... <movei>
if (tokens[1] == "startpos")
{
_engine.SetupPosition();
}
else if (tokens[1] == "fen") //rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
{
string fen = string.Join(' ', tokens, 2, tokens.Length - 2);
_engine.SetupPosition(fen);
}
else
{
Uci.Log("'position' parameters missing or not understood. Assuming 'startpos'.");
_engine.SetupPosition();
}
int firstMove = Array.IndexOf(tokens, "moves") + 1;
if (firstMove == 0)
{
return;
}
for (int i = firstMove; i < tokens.Length; i++)
{
Move move = MoveFromUciNotation(tokens[i]);
_engine.Play(move);
}
}
//*****************
//*** INTERNALS ***
//*****************
private void Search()
{
_tN = Now;
_search.StartSearch(() => RemainingTimeBudget < 0);
_best = _search.bestMove;
Uci.BestMove(_best);
_search = null;
return;
}
internal void Go(int blackTime, int whiteTime, int blackIncrement, int whiteIncrement, int movesToGo, int maxSearchDepth)
{
Stop();
_searchDepth = maxSearchDepth;
int myTime = _board.WhiteToMove ? whiteTime : blackTime;
int myIncrement = _board.WhiteToMove ? whiteIncrement : blackIncrement;
int totalTime = myTime + myIncrement * (movesToGo - 1) - MOVE_TIME_MARGIN;
_timeBudget = totalTime / movesToGo;
Uci.Log($"Search budget set to {_timeBudget}ms!");
StartSearch();
}
private void Collect()
{
_best = _search.PrincipalVariation[0];
Uci.Info(
depth: _search.Depth,
score: (int)SideToMove * _search.Score,
nodes: _search.NodesVisited,
timeMs: _time.Elapsed,
pv: GetPrintablePV(_search.PrincipalVariation, _search.Depth)
);
}
private void Search()
{
while (CanSearchDeeper())
{
_time.StartInterval();
_search.SearchDeeper(_time.CheckTimeBudget);
//aborted?
if (_search.Aborted)
{
break;
}
//collect PV
Collect();
}
//Done searching!
Uci.BestMove(_best);
_search = null;
}
//*****************
//*** INTERNALS ***
//*****************
private void StartSearch(int maxDepth, long maxNodes)
{
//do the first iteration. it's cheap, no time check, no thread
Uci.Log($"Search scheduled to take {_time.TimePerMoveWithMargin}ms!");
//add all history positions with a score of 0 (Draw through 3-fold repetition) and freeze them by setting a depth that is never going to be overwritten
foreach (var position in _history)
{
Transpositions.Store(position.ZobristHash, Transpositions.HISTORY, 0, SearchWindow.Infinite, 0, default);
}
_search = new IterativeSearch(_board, maxNodes);
_time.StartInterval();
_search.SearchDeeper();
Collect();
//start the search thread
_maxSearchDepth = maxDepth;
_searching = new Thread(Search)
{
Priority = ThreadPriority.Highest
};
_searching.Start();
}