/// <summary>
/// Decrements or increments the parameter score, in regard to the pieces position on the board.
/// Method should be used for pawns.
/// </summary>
private static void AddPawnScores(Board.Board board, int colour,
ref int score)
{
var pceType = colour == (int)Colour.WHITE ? (int)Piece.wP : (int)Piece.bP;
for (var i = 0; i < board.PceNum[pceType]; ++i)
{
var sq = board.PList[pceType, i];
Debug.Assert(Validators.SqOnBoard(sq));
var sq64 = Conversion.getSq120ToSq64(sq);
var value = colour == (int)Colour.WHITE
? Evaluate.pawnTable[sq64]
: -Evaluate.pawnTable[Data.mirror64Table[sq64]];
score += value;
// If pawn we need to consider whether it's isolated and on what rank.
if (colour == (int)Colour.WHITE)
{
if ((EvalBitMask.GetIsolatedMask(sq64) & board.Pawns[(int)Colour.WHITE]) ==
0)
{
score += Evaluate.PAWN_ISOLATED_VAL;
}
if ((EvalBitMask.GetWhitePassedMask(sq64) &
board.Pawns[(int)Colour.BLACK]) == 0)
{
var rank = Conversion.getRanksBrd(sq);
Debug.Assert(Validators.FileOrRankValid(rank));
score += Evaluate.PAWN_PASSED_VAL[rank];
}
}
else
{
if ((EvalBitMask.GetIsolatedMask(sq64) & board.Pawns[(int)Colour.BLACK]) ==
0)
{
score -= Evaluate.PAWN_ISOLATED_VAL;
}
if ((EvalBitMask.GetBlackPassedMask(sq64) &
board.Pawns[(int)Colour.WHITE]) == 0)
{
var rank = Conversion.getRanksBrd(sq);
Debug.Assert(Validators.FileOrRankValid(rank));
score -= Evaluate.PAWN_PASSED_VAL[7 - rank];
}
}
}
}
/// <summary>
/// Decrements or increments the parameter score, in regard to the pieces position on the board.
/// Method should be used for queens and rooks.
/// </summary>
private static void AddRookOrQueenScores(Board.Board board, int pceType, ref int score)
{
Debug.Assert(Data.IsPieceRookQueen(pceType));
var colour = (int)Data.PIECE_COLOURS[pceType];
for (var i = 0; i < board.PceNum[pceType]; ++i)
{
var sq = board.PList[pceType, i];
Debug.Assert(Validators.SqOnBoard(sq));
var sq64 = Conversion.getSq120ToSq64(sq);
var value = colour == (int)Colour.WHITE
? Evaluate.pawnTable[sq64]
: -Evaluate.pawnTable[Data.mirror64Table[sq64]];
score += value;
var file = Conversion.getFilesBrd(sq);
var fileValue = 0;
if ((EvalBitMask.GetFilesMask(file) & board.Pawns[(int)Colour.BOTH]) == 0)
{
// Is piece Rook
if (!Data.IsPieceBishopQueen(pceType) && Data.IsPieceRookQueen(pceType))
{
fileValue = Evaluate.ROOK_OPEN_FILE_VAL;
}
else
{
// Else piece is queen
fileValue = Evaluate.QUEEN_OPEN_FILE_VAL;
}
}
else if ((EvalBitMask.GetFilesMask(file) & board.Pawns[colour]) == 0)
{
if (!Data.IsPieceBishopQueen(pceType) && Data.IsPieceRookQueen(pceType))
{
fileValue = Evaluate.ROOK_SEMI_OPEN_FILE_VAL;
}
else
{
// Piece is queen
fileValue = Evaluate.QUEEN_SEMI_OPEN_FILE_VAL;
}
}
fileValue = colour == (int)Colour.WHITE ? fileValue : -fileValue;
score += fileValue;
}
}