public int EvaluatePawns(ref Position position, int color)
{
int score = 0;
Bitboard myPawns = position.GetPieceBitboard(color, Position.PAWN);
Bitboard myPieces = position.GetPieceBitboard(color, Position.ALL_PIECES);
Bitboard opponentPawns =
position.GetPieceBitboard(color == Position.WHITE ? Position.BLACK : Position.WHITE, Position.PAWN);
Bitboard allPawns = myPawns | opponentPawns;
Bitboard pawns = myPawns;
while (pawns != 0)
{
score += materialValues[Position.PAWN];
int currSquare = pawns.BitScanForward();
Bitboards.PopLsb(ref pawns);
// Add bonus based on file of pawn (to promote taking towards the center)
score += pawnFileBonus[Bitboards.GetColumn(currSquare)];
// Analyze stacked pawns
Bitboard filePawns = Bitboards.ColumnBitboards[currSquare] & myPawns;
if ((filePawns & (filePawns - 1)) != 0) // More than 1 pawn in this rank
{
score -= stackedPawnPenalty;
}
// Analyze isolated pawns
if ((Bitboards.IsolatedPawnBitboards[currSquare] & myPawns) == 0)
{
score -= isolatedPawnPenalty;
}
// Analyze passed pawns
if ((Bitboards.PassedPawnBitboards[color, currSquare] & allPawns) == 0)
{
score += passedPawnBonus[color, Bitboards.GetRow(currSquare)];
}
Bitboard pawnAttacks = Bitboards.PawnBitboards[color, currSquare];
while (pawnAttacks != 0)
{
int attackSquare = pawnAttacks.BitScanForward();
Bitboards.PopLsb(ref pawnAttacks);
int attackedPiece = position.GetPieceSquares()[attackSquare];
if (attackedPiece == Position.EMPTY || (myPieces & Bitboards.SquareBitboards[attackSquare]) != 0)
{
continue;
}
score += attackBonus[attackedPiece];
}
}
return(score);
}
public int EvaluatePawnStructure(Position position, int color)
{
int score = 0;
Bitboard myPawns = position.GetPieceBitboard(color, Position.PAWN);
Bitboard opponentPawns =
position.GetPieceBitboard(color == Position.WHITE ? Position.BLACK : Position.WHITE, Position.PAWN);
Bitboard allPawns = myPawns | opponentPawns;
Bitboard pawns = myPawns;
while (pawns != 0)
{
int currSquare = pawns.BitScanForward();
Bitboards.PopLsb(ref pawns);
// Add bonus based on file of pawn (to promote taking towards the center)
score += pawnFileBonus[Bitboards.GetColumn(currSquare)];
// Analyze stacked pawns
Bitboard filePawns = Bitboards.ColumnBitboards[currSquare] & myPawns;
if ((filePawns & (filePawns - 1)) != 0) // More than 1 pawn in this rank
{
score -= stackedPawnPenalty;
}
// Analyze isolated pawns
if ((Bitboards.IsolatedPawnBitboards[currSquare] & myPawns) == 0)
{
score -= isolatedPawnPenalty;
}
// Analyze passed pawns
if ((Bitboards.PassedPawnBitboards[color, currSquare] & allPawns) == 0)
{
score += passedPawnBonus[color, Bitboards.GetRow(currSquare)];
}
}
return(score);
}
