public static MetricWeights ReadMetricWeightsXml(XmlReader xmlReader)
{
if (null == xmlReader)
{
throw new ArgumentNullException("xmlReader");
}
MetricWeights mw = new MetricWeights();
while (xmlReader.Read())
{
if (xmlReader.IsStartElement() && !xmlReader.Name.EndsWith("MetricWeights"))
{
string key = xmlReader.Name;
double value = xmlReader.ReadElementContentAsDouble();
BugType bugType;
BugTypeWeight bugTypeWeight;
if (TryParseKeyName(key, out bugType, out bugTypeWeight))
{
mw.Set(bugType, bugTypeWeight, value + mw.Get(bugType, bugTypeWeight));
}
}
}
return(mw);
}
public GameAI()
{
StartMetricWeights = new MetricWeights();
EndMetricWeights = new MetricWeights();
TranspositionTable = new TranspositionTable();
}
public GameAI(GameAIConfig config)
{
if (null == config)
{
throw new ArgumentNullException("config");
}
StartMetricWeights = config.StartMetricWeights?.Clone() ?? new MetricWeights();
EndMetricWeights = config.EndMetricWeights?.Clone() ?? new MetricWeights();
if (config.TranspositionTableSizeMB.HasValue)
{
if (config.TranspositionTableSizeMB.Value <= 0)
{
throw new ArgumentOutOfRangeException("config.TranspositionTableSizeMB");
}
_transpositionTable = new TranspositionTable(config.TranspositionTableSizeMB.Value * 1024 * 1024);
}
else
{
_transpositionTable = new TranspositionTable();
}
if (config.MaxBranchingFactor.HasValue)
{
if (config.MaxBranchingFactor.Value <= 0)
{
throw new ArgumentOutOfRangeException("config.MaxBranchingFactor");
}
_maxBranchingFactor = config.MaxBranchingFactor.Value;
}
}
private void DeltaFromTransTable(GameBoard gameBoard, HashSet <ulong> visitedKeys, CancellationToken token, out MetricWeights deltaStart, out MetricWeights deltaEnd)
{
MetricWeights ds = new MetricWeights();
MetricWeights de = new MetricWeights();
ulong key = gameBoard.ZobristKey;
bool newKey = visitedKeys.Add(key);
if (newKey && TranspositionTable.TryLookup(key, out TranspositionTableEntry tEntry) && tEntry.Depth > 1 && !token.IsCancellationRequested)
{
double colorValue = gameBoard.CurrentTurnColor == PlayerColor.White ? 1.0 : -1.0;
double boardScore = colorValue * TruncateBounds(CalculateBoardScore(gameBoard));
double storedValue = TruncateBounds(tEntry.Value);
BoardMetrics boardMetrics = gameBoard.GetBoardMetrics();
MetricWeights startGradient = GetGradient(boardMetrics);
MetricWeights endGradient = startGradient.Clone();
double scaleFactor = TreeStrapStepConstant * (storedValue - boardScore);
double startRatio = boardMetrics.PiecesInHand / (double)(boardMetrics.PiecesInHand + boardMetrics.PiecesInPlay);
double endRatio = 1 - startRatio;
startGradient.Scale(scaleFactor * startRatio * colorValue);
endGradient.Scale(scaleFactor * endRatio * colorValue);
if ((tEntry.Type == TranspositionTableEntryType.LowerBound || tEntry.Type == TranspositionTableEntryType.Exact) && storedValue > boardScore)
{
ds.Add(startGradient);
de.Add(endGradient);
}
if ((tEntry.Type == TranspositionTableEntryType.UpperBound || tEntry.Type == TranspositionTableEntryType.Exact) && storedValue < boardScore)
{
ds.Add(startGradient);
de.Add(endGradient);
}
foreach (Move move in GetValidMoves(gameBoard))
{
if (token.IsCancellationRequested)
{
break;
}
gameBoard.TrustedPlay(move);
DeltaFromTransTable(gameBoard, visitedKeys, token, out MetricWeights ds1, out MetricWeights de1);
ds.Add(ds1);
de.Add(de1);
gameBoard.UndoLastMove();
}
}
deltaStart = ds;
deltaEnd = de;
}
public MetricWeights Clone()
{
MetricWeights clone = new MetricWeights();
clone.CopyFrom(this);
return(clone);
}
public void CopyFrom(MetricWeights source)
{
if (null == source)
{
throw new ArgumentNullException("source");
}
Array.Copy(source._bugTypeWeights, _bugTypeWeights, source._bugTypeWeights.Length);
}
public void Add(MetricWeights a)
{
if (null == a)
{
throw new ArgumentNullException("a");
}
for (int i = 0; i < _bugTypeWeights.Length; i++)
{
_bugTypeWeights[i] += a._bugTypeWeights[i];
}
}
private static double CalculateBoardScore(BoardMetrics boardMetrics, MetricWeights startMetricWeights, MetricWeights endMetricWeights)
{
double endScore = CalculateBoardScore(boardMetrics, endMetricWeights);
if (boardMetrics.PiecesInHand == 0)
{
// In "end-game", no need to blend
return(endScore);
}
else
{
// Pieces still in hand, blend start and end scores
double startScore = CalculateBoardScore(boardMetrics, startMetricWeights);
double startRatio = boardMetrics.PiecesInHand / (double)(boardMetrics.PiecesInHand + boardMetrics.PiecesInPlay);
double endRatio = 1 - startRatio;
return((startRatio * startScore) + (endRatio * endScore));
}
}
private MetricWeights GetGradient(BoardMetrics boardMetrics)
{
MetricWeights gradient = new MetricWeights();
foreach (PieceName pieceName in EnumUtils.PieceNames)
{
BugType bugType = EnumUtils.GetBugType(pieceName);
double colorValue = EnumUtils.GetColor(pieceName) == PlayerColor.White ? 1.0 : -1.0;
gradient.Set(bugType, BugTypeWeight.InPlayWeight, gradient.Get(bugType, BugTypeWeight.InPlayWeight) + colorValue * boardMetrics[pieceName].InPlay);
gradient.Set(bugType, BugTypeWeight.IsPinnedWeight, gradient.Get(bugType, BugTypeWeight.IsPinnedWeight) + colorValue * boardMetrics[pieceName].IsPinned);
gradient.Set(bugType, BugTypeWeight.IsCoveredWeight, gradient.Get(bugType, BugTypeWeight.IsCoveredWeight) + colorValue * boardMetrics[pieceName].IsCovered);
gradient.Set(bugType, BugTypeWeight.NoisyMoveWeight, gradient.Get(bugType, BugTypeWeight.NoisyMoveWeight) + colorValue * boardMetrics[pieceName].NoisyMoveCount);
gradient.Set(bugType, BugTypeWeight.QuietMoveWeight, gradient.Get(bugType, BugTypeWeight.QuietMoveWeight) + colorValue * boardMetrics[pieceName].QuietMoveCount);
gradient.Set(bugType, BugTypeWeight.FriendlyNeighborWeight, gradient.Get(bugType, BugTypeWeight.FriendlyNeighborWeight) + colorValue * boardMetrics[pieceName].FriendlyNeighborCount);
gradient.Set(bugType, BugTypeWeight.EnemyNeighborWeight, gradient.Get(bugType, BugTypeWeight.EnemyNeighborWeight) + colorValue * boardMetrics[pieceName].EnemyNeighborCount);
}
return(gradient);
}
private static double CalculateBoardScore(BoardMetrics boardMetrics, MetricWeights metricWeights)
{
double score = 0;
foreach (PieceName pieceName in EnumUtils.PieceNames)
{
BugType bugType = EnumUtils.GetBugType(pieceName);
double colorValue = EnumUtils.GetColor(pieceName) == PlayerColor.White ? 1.0 : -1.0;
score += colorValue * metricWeights.Get(bugType, BugTypeWeight.InPlayWeight) * boardMetrics[pieceName].InPlay;
score += colorValue * metricWeights.Get(bugType, BugTypeWeight.IsPinnedWeight) * boardMetrics[pieceName].IsPinned;
score += colorValue * metricWeights.Get(bugType, BugTypeWeight.IsCoveredWeight) * boardMetrics[pieceName].IsCovered;
score += colorValue * metricWeights.Get(bugType, BugTypeWeight.NoisyMoveWeight) * boardMetrics[pieceName].NoisyMoveCount;
score += colorValue * metricWeights.Get(bugType, BugTypeWeight.QuietMoveWeight) * boardMetrics[pieceName].QuietMoveCount;
score += colorValue * metricWeights.Get(bugType, BugTypeWeight.FriendlyNeighborWeight) * boardMetrics[pieceName].FriendlyNeighborCount;
score += colorValue * metricWeights.Get(bugType, BugTypeWeight.EnemyNeighborWeight) * boardMetrics[pieceName].EnemyNeighborCount;
}
return(score);
}
public MetricWeights GetNormalized(double targetMaxValue = 100.0, bool round = true, int decimals = 6)
{
if (targetMaxValue <= 0.0)
{
throw new ArgumentOutOfRangeException("targetMaxValue");
}
MetricWeights clone = Clone();
// Copy bug weights into local array
double[] dblWeights = new double[clone._bugTypeWeights.Length];
Array.Copy(clone._bugTypeWeights, dblWeights, clone._bugTypeWeights.Length);
double max = double.MinValue;
foreach (double weight in dblWeights)
{
max = Math.Max(max, Math.Abs(weight));
}
// Normalize to new range
for (int i = 0; i < dblWeights.Length; i++)
{
double value = dblWeights[i];
int sign = Math.Sign(value);
double absValue = Math.Abs(value);
dblWeights[i] = sign * (absValue / max) * targetMaxValue;
}
// Populate clone with normalized weights
for (int i = 0; i < clone._bugTypeWeights.Length; i++)
{
clone._bugTypeWeights[i] = round ? Math.Round(dblWeights[i], decimals) : dblWeights[i];
}
return(clone);
}
