public Engine(string[] args)
{
inOut.WriteLine(Misc.engine_info(), MutexAction.ATOMIC);
Uci.init(Options);
BitBoard.init();
Position.init();
Bitbases.init_kpk();
Search.init();
Pawns.init();
Eval.init();
Threads.init();
TT.resize((ulong)Options["Hash"].getInt());
Uci.loop(args);
Threads.exit();
}
/// init() computes evaluation weights from the corresponding UCI parameters
/// and setup king tables.
public static void init()
{
Weights[EvalWeightS.Mobility] = weight_option("Mobility (Midgame)", "Mobility (Endgame)", WeightsInternal[EvalWeightS.Mobility]);
Weights[EvalWeightS.PawnStructure] = weight_option("Pawn Structure (Midgame)", "Pawn Structure (Endgame)", WeightsInternal[EvalWeightS.PawnStructure]);
Weights[EvalWeightS.PassedPawns] = weight_option("Passed Pawns (Midgame)", "Passed Pawns (Endgame)", WeightsInternal[EvalWeightS.PassedPawns]);
Weights[EvalWeightS.Space] = weight_option("Space", "Space", WeightsInternal[EvalWeightS.Space]);
Weights[EvalWeightS.KingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[EvalWeightS.KingDangerUs]);
Weights[EvalWeightS.KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[EvalWeightS.KingDangerThem]);
const int MaxSlope = 30;
const int Peak = 1280;
for (int t = 0, i = 1; i < 100; ++i)
{
t = Math.Min(Peak, Math.Min((int)(0.4 * i * i), t + MaxSlope));
KingDanger[1][i] = Eval.apply_weight(Types.make_score(t, 0), Weights[EvalWeightS.KingDangerUs]);
KingDanger[0][i] = Eval.apply_weight(Types.make_score(t, 0), Weights[EvalWeightS.KingDangerThem]);
}
}
// do_evaluate() is the evaluation entry point, called directly from evaluate()
public static Value do_evaluate(Position pos, bool Trace)
{
Debug.Assert(0 == pos.checkers());
EvalInfo ei = new EvalInfo();
Score score;
Score[] mobility = new Score[] { ScoreS.SCORE_ZERO, ScoreS.SCORE_ZERO };
Thread thisThread = pos.this_thread();
// Initialize score by reading the incrementally updated scores included
// in the position object (material + piece square tables) and adding a
// Tempo bonus. Score is computed from the point of view of white.
score = pos.psq_score() + (pos.side_to_move() == ColorS.WHITE ? Tempo : -Tempo);
// Probe the material hash table
ei.mi = Material.probe(pos, thisThread.materialTable, thisThread.endgames);
score += ei.mi.material_value();
// If we have a specialized evaluation function for the current material
// configuration, call it and return.
if (ei.mi.specialized_eval_exists())
{
return(ei.mi.evaluate(pos));
}
// Probe the pawn hash table
ei.pi = Pawns.probe(pos, thisThread.pawnsTable);
score += apply_weight(ei.pi.pawns_value(), Weights[EvalWeightS.PawnStructure]);
// Initialize attack and king safety bitboards
init_eval_info(pos, ei, ColorS.WHITE);
init_eval_info(pos, ei, ColorS.BLACK);
ei.attackedBy[ColorS.WHITE][PieceTypeS.ALL_PIECES] |= ei.attackedBy[ColorS.WHITE][PieceTypeS.KING];
ei.attackedBy[ColorS.BLACK][PieceTypeS.ALL_PIECES] |= ei.attackedBy[ColorS.BLACK][PieceTypeS.KING];
// Do not include in mobility squares protected by enemy pawns or occupied by our pawns or king
Bitboard[] mobilityArea = new Bitboard[] { ~(ei.attackedBy[ColorS.BLACK][PieceTypeS.PAWN] | pos.pieces_color_piecetype(ColorS.WHITE, PieceTypeS.PAWN, PieceTypeS.KING)),
~(ei.attackedBy[ColorS.WHITE][PieceTypeS.PAWN] | pos.pieces_color_piecetype(ColorS.BLACK, PieceTypeS.PAWN, PieceTypeS.KING)) };
// Evaluate pieces and mobility
score += evaluate_pieces(pos, ei, mobility, mobilityArea, PieceTypeS.KNIGHT, ColorS.WHITE, Trace);
score += Eval.apply_weight(mobility[ColorS.WHITE] - mobility[ColorS.BLACK], Weights[EvalWeightS.Mobility]);
// Evaluate kings after all other pieces because we need complete attack
// information when computing the king safety evaluation.
score += evaluate_king(pos, ei, ColorS.WHITE, Trace)
- evaluate_king(pos, ei, ColorS.BLACK, Trace);
// Evaluate tactical threats, we need full attack information including king
score += evaluate_threats(pos, ei, ColorS.WHITE, Trace)
- evaluate_threats(pos, ei, ColorS.BLACK, Trace);
// Evaluate passed pawns, we need full attack information including king
score += evaluate_passed_pawns(pos, ei, ColorS.WHITE, Trace)
- evaluate_passed_pawns(pos, ei, ColorS.BLACK, Trace);
// If one side has only a king, check whether exists any unstoppable passed pawn
if (0 == pos.non_pawn_material(ColorS.WHITE) || 0 == pos.non_pawn_material(ColorS.BLACK))
{
score += evaluate_unstoppable_pawns(pos, ColorS.WHITE, ei)
- evaluate_unstoppable_pawns(pos, ColorS.BLACK, ei);
}
// Evaluate space for both sides, only in middle-game.
if (ei.mi.space_weight() != 0)
{
int s = evaluate_space(pos, ei, ColorS.WHITE) - evaluate_space(pos, ei, ColorS.BLACK);
score += Eval.apply_weight(s * ei.mi.space_weight(), Weights[EvalWeightS.Space]);
}
// Scale winning side if position is more drawish that what it appears
ScaleFactor sf = Types.eg_value(score) > ValueS.VALUE_DRAW ? ei.mi.scale_factor(pos, ColorS.WHITE)
: ei.mi.scale_factor(pos, ColorS.BLACK);
// If we don't already have an unusual scale factor, check for opposite
// colored bishop endgames, and use a lower scale for those.
if (ei.mi.game_phase() < PhaseS.PHASE_MIDGAME &&
pos.opposite_bishops() &&
(sf == ScaleFactorS.SCALE_FACTOR_NORMAL || sf == ScaleFactorS.SCALE_FACTOR_ONEPAWN))
{
// Ignoring any pawns, do both sides only have a single bishop and no
// other pieces?
if (pos.non_pawn_material(ColorS.WHITE) == ValueS.BishopValueMg &&
pos.non_pawn_material(ColorS.BLACK) == ValueS.BishopValueMg)
{
// Check for KBP vs KB with only a single pawn that is almost
// certainly a draw or at least two pawns.
bool one_pawn = (pos.count(ColorS.WHITE, PieceTypeS.PAWN) + pos.count(ColorS.BLACK, PieceTypeS.PAWN) == 1);
sf = one_pawn ? (8) : (32);
}
else
{
// Endgame with opposite-colored bishops, but also other pieces. Still
// a bit drawish, but not as drawish as with only the two bishops.
sf = (50 * sf / ScaleFactorS.SCALE_FACTOR_NORMAL);
}
}
// Interpolate between a middlegame and a (scaled by 'sf') endgame score
Value v = Types.mg_value(score) * (ei.mi.game_phase())
+ Types.eg_value(score) * (PhaseS.PHASE_MIDGAME - ei.mi.game_phase()) * sf / ScaleFactorS.SCALE_FACTOR_NORMAL;
v /= (PhaseS.PHASE_MIDGAME);
// In case of tracing add all single evaluation contributions for both white and black
if (Trace)
{
//Tracing.add_term(Tracing.PST, pos.psq_score());
//Tracing.add_term(Tracing.IMBALANCE, ei.mi.material_value());
//Tracing.add_term(PAWN, ei.pi.pawns_value());
//Tracing.add_term(Tracing.MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility])
// , apply_weight(mobility[BLACK], Weights[Mobility]));
//Score w = ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei);
//Score b = ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei);
//Tracing.add_term(Tracing.SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
//Tracing.add_term(Tracing.TOTAL, score);
//Tracing.ei = ei;
//Tracing.sf = sf;
}
return(pos.side_to_move() == ColorS.WHITE ? v : -v);
}
// evaluate_passed_pawns() evaluates the passed pawns of the given color
public static Score evaluate_passed_pawns(Position pos, EvalInfo ei, Color Us, bool Trace)
{
Color Them = (Us == ColorS.WHITE ? ColorS.BLACK : ColorS.WHITE);
Bitboard b, squaresToQueen, defendedSquares, unsafeSquares;
Score score = ScoreS.SCORE_ZERO;
b = ei.pi.passed_pawns(Us);
while (b != 0)
{
Square s = BitBoard.pop_lsb(ref b);
Debug.Assert(pos.pawn_passed(Us, s));
int r = (int)(Types.relative_rank_square(Us, s) - RankS.RANK_2);
int rr = r * (r - 1);
// Base bonus based on rank
Value mbonus = (17 * rr), ebonus = (7 * (rr + r + 1));
if (rr != 0)
{
Square blockSq = s + Types.pawn_push(Us);
// Adjust bonus based on kings proximity
ebonus += (BitBoard.square_distance(pos.king_square(Them), blockSq) * 5 * rr)
- (BitBoard.square_distance(pos.king_square(Us), blockSq) * 2 * rr);
// If blockSq is not the queening square then consider also a second push
if (Types.relative_rank_square(Us, blockSq) != RankS.RANK_8)
{
ebonus -= (BitBoard.square_distance(pos.king_square(Us), blockSq + Types.pawn_push(Us)) * rr);
}
// If the pawn is free to advance, increase bonus
if (pos.empty(blockSq))
{
squaresToQueen = BitBoard.forward_bb(Us, s);
// If there is an enemy rook or queen attacking the pawn from behind,
// add all X-ray attacks by the rook or queen. Otherwise consider only
// the squares in the pawn's path attacked or occupied by the enemy.
if ((BitBoard.forward_bb(Them, s) & pos.pieces_color_piecetype(Them, PieceTypeS.ROOK, PieceTypeS.QUEEN)) != 0 &&
(BitBoard.forward_bb(Them, s) & pos.pieces_color_piecetype(Them, PieceTypeS.ROOK, PieceTypeS.QUEEN) & pos.attacks_from_square_piecetype(s, PieceTypeS.ROOK)) != 0)
{
unsafeSquares = squaresToQueen;
}
else
{
unsafeSquares = squaresToQueen & (ei.attackedBy[Them][PieceTypeS.ALL_PIECES] | pos.pieces_color(Them));
}
if ((BitBoard.forward_bb(Them, s) & pos.pieces_color_piecetype(Us, PieceTypeS.ROOK, PieceTypeS.QUEEN)) != 0 &&
(BitBoard.forward_bb(Them, s) & pos.pieces_color_piecetype(Us, PieceTypeS.ROOK, PieceTypeS.QUEEN) & pos.attacks_from_square_piecetype(s, PieceTypeS.ROOK)) != 0)
{
defendedSquares = squaresToQueen;
}
else
{
defendedSquares = squaresToQueen & ei.attackedBy[Us][PieceTypeS.ALL_PIECES];
}
// If there aren't any enemy attacks, assign a big bonus. Otherwise
// assign a smaller bonus if the block square isn't attacked.
int k = 0 == unsafeSquares? 15 : 0 == (unsafeSquares & BitBoard.SquareBB[blockSq]) ? 9 : 0;
// If the path to queen is fully defended, assign a big bonus.
// Otherwise assign a smaller bonus if the block square is defended.
if (defendedSquares == squaresToQueen)
{
k += 6;
}
else if ((defendedSquares & BitBoard.SquareBB[blockSq]) != 0)
{
k += 4;
}
mbonus += (k * rr); ebonus += (k * rr);
}
} // rr != 0
if (pos.count(Us, PieceTypeS.PAWN) < pos.count(Them, PieceTypeS.PAWN))
{
ebonus += ebonus / 4;
}
score += Types.make_score(mbonus, ebonus);
}
if (Trace)
{
Tracing.terms[Us][TermsS.PASSED] = apply_weight(score, Weights[EvalWeightS.PassedPawns]);
}
// Add the scores to the middle game and endgame eval
return(Eval.apply_weight(score, Weights[EvalWeightS.PassedPawns]));
}
