public static MagicContainer[] GenerateRookAttacks(ulong[] keys = null)
{
var masks = new ulong[64];
var permutations = new ulong[64][];
var attacks = new ulong[64][];
for (var fieldIndex = 0; fieldIndex < 64; fieldIndex++)
{
masks[fieldIndex] = (FilePatternGenerator.GetPatternForField(fieldIndex) & ~BoardConstants.TopBottomEdge) |
(RankPatternGenerator.GetPatternForField(fieldIndex) & ~BoardConstants.RightLeftEdge);
permutations[fieldIndex] = new ulong[1 << MagicShifts.RookShifts[fieldIndex]];
attacks[fieldIndex] = new ulong[1 << MagicShifts.RookShifts[fieldIndex]];
for (var permutationIndex = 0; permutationIndex < permutations[fieldIndex].Length; permutationIndex++)
{
permutations[fieldIndex][permutationIndex] = PermutationsGenerator.GetPermutation(masks[fieldIndex], permutationIndex);
attacks[fieldIndex][permutationIndex] = AttacksGenerator.GetFileRankAttacks(permutations[fieldIndex][permutationIndex], fieldIndex);
}
}
return(_rookMagicArray = GenerateAttacks(masks, permutations, attacks, MagicShifts.RookShifts, keys));
}
public static int Evaluate(BoardState board, int color, int openingPhase, int endingPhase)
{
var doubledRooks = 0;
var rooksOnOpenFile = 0;
var enemyColor = ColorOperations.Invert(color);
var rooks = board.Pieces[color][Piece.Rook];
while (rooks != 0)
{
var lsb = BitOperations.GetLsb(rooks);
var field = BitOperations.BitScan(lsb);
rooks = BitOperations.PopLsb(rooks);
var file = FilePatternGenerator.GetPatternForField(field) | lsb;
var rooksOnFile = file & board.Pieces[color][Piece.Rook];
var friendlyPawnsOnFile = file & board.Pieces[color][Piece.Pawn];
var enemyPawnsOnFile = file & board.Pieces[enemyColor][Piece.Pawn];
if (BitOperations.Count(rooksOnFile) > 1)
{
// We don't assume that there will be more than two rooks - even if, then this color is probably anyway winning
doubledRooks = 1;
}
if (friendlyPawnsOnFile == 0 && enemyPawnsOnFile == 0)
{
rooksOnOpenFile++;
}
}
var doubledRooksOpeningScore = doubledRooks * EvaluationConstants.DoubledRooks;
var rooksOnOpenFileOpeningScore = rooksOnOpenFile * EvaluationConstants.RookOnOpenFile;
var openingScore = doubledRooksOpeningScore + rooksOnOpenFileOpeningScore;
return(TaperedEvaluation.AdjustToPhase(openingScore, 0, openingPhase, endingPhase));
}
