2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2009 Marco Costalba
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
34 #include "ucioption.h"
38 //// Local definitions
43 const int Sign[2] = { 1, -1 };
45 // Evaluation grain size, must be a power of 2
46 const int GrainSize = 8;
48 // Evaluation weights, initialized from UCI options
49 int WeightMobilityMidgame, WeightMobilityEndgame;
50 int WeightPawnStructureMidgame, WeightPawnStructureEndgame;
51 int WeightPassedPawnsMidgame, WeightPassedPawnsEndgame;
52 int WeightKingSafety[2];
55 // Internal evaluation weights. These are applied on top of the evaluation
56 // weights read from UCI parameters. The purpose is to be able to change
57 // the evaluation weights while keeping the default values of the UCI
58 // parameters at 100, which looks prettier.
60 // Values modified by Joona Kiiski
61 const int WeightMobilityMidgameInternal = 248;
62 const int WeightMobilityEndgameInternal = 271;
63 const int WeightPawnStructureMidgameInternal = 233;
64 const int WeightPawnStructureEndgameInternal = 201;
65 const int WeightPassedPawnsMidgameInternal = 252;
66 const int WeightPassedPawnsEndgameInternal = 259;
67 const int WeightKingSafetyInternal = 247;
68 const int WeightKingOppSafetyInternal = 259;
69 const int WeightSpaceInternal = 46;
71 // Mobility and outposts bonus modified by Joona Kiiski
73 // Visually better to define tables constants
76 // Knight mobility bonus in middle game and endgame, indexed by the number
77 // of attacked squares not occupied by friendly piecess.
78 const Value MidgameKnightMobilityBonus[] = {
80 V(-38), V(-25),V(-12), V(0), V(12), V(25), V(31), V(38), V(38)
83 const Value EndgameKnightMobilityBonus[] = {
85 V(-33), V(-23),V(-13), V(-3), V(7), V(17), V(22), V(27), V(27)
88 // Bishop mobility bonus in middle game and endgame, indexed by the number
89 // of attacked squares not occupied by friendly pieces. X-ray attacks through
90 // queens are also included.
91 const Value MidgameBishopMobilityBonus[] = {
93 V(-25), V(-11), V(3), V(17), V(31), V(45), V(57), V(65),
94 // 8 9 10 11 12 13 14 15
95 V( 71), V( 74), V(76), V(78), V(79), V(80), V(81), V(81)
98 const Value EndgameBishopMobilityBonus[] = {
100 V(-30), V(-16), V(-2), V(12), V(26), V(40), V(52), V(60),
101 // 8 9 10 11 12 13 14 15
102 V( 65), V( 69), V(71), V(73), V(74), V(75), V(76), V(76)
105 // Rook mobility bonus in middle game and endgame, indexed by the number
106 // of attacked squares not occupied by friendly pieces. X-ray attacks through
107 // queens and rooks are also included.
108 const Value MidgameRookMobilityBonus[] = {
110 V(-20), V(-14), V(-8), V(-2), V(4), V(10), V(14), V(19),
111 // 8 9 10 11 12 13 14 15
112 V( 23), V( 26), V(27), V(28), V(29), V(30), V(31), V(32)
115 const Value EndgameRookMobilityBonus[] = {
117 V(-36), V(-19), V(-3), V(13), V(29), V(46), V(62), V(79),
118 // 8 9 10 11 12 13 14 15
119 V( 95), V(106),V(111),V(114),V(116),V(117),V(118),V(118)
122 // Queen mobility bonus in middle game and endgame, indexed by the number
123 // of attacked squares not occupied by friendly pieces.
124 const Value MidgameQueenMobilityBonus[] = {
126 V(-10), V(-8), V(-6), V(-3), V(-1), V( 1), V( 3), V( 5),
127 // 8 9 10 11 12 13 14 15
128 V( 8), V(10), V(12), V(15), V(16), V(17), V(18), V(20),
129 // 16 17 18 19 20 21 22 23
130 V( 20), V(20), V(20), V(20), V(20), V(20), V(20), V(20),
131 // 24 25 26 27 28 29 30 31
132 V( 20), V(20), V(20), V(20), V(20), V(20), V(20), V(20)
135 const Value EndgameQueenMobilityBonus[] = {
137 V(-18),V(-13), V(-7), V(-2), V( 3), V (8), V(13), V(19),
138 // 8 9 10 11 12 13 14 15
139 V( 23), V(27), V(32), V(34), V(35), V(35), V(35), V(35),
140 // 16 17 18 19 20 21 22 23
141 V( 35), V(35), V(35), V(35), V(35), V(35), V(35), V(35),
142 // 24 25 26 27 28 29 30 31
143 V( 35), V(35), V(35), V(35), V(35), V(35), V(35), V(35)
146 // Outpost bonuses for knights and bishops, indexed by square (from white's
148 const Value KnightOutpostBonus[64] = {
150 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 1
151 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 2
152 V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0), // 3
153 V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0), // 4
154 V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0), // 5
155 V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0), // 6
156 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 7
157 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8
160 const Value BishopOutpostBonus[64] = {
162 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 1
163 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 2
164 V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0), // 3
165 V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0), // 4
166 V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0), // 5
167 V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0), // 6
168 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 7
169 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8
172 // Bonus for unstoppable passed pawns
173 const Value UnstoppablePawnValue = Value(0x500);
175 // Rooks and queens on the 7th rank (modified by Joona Kiiski)
176 const Value MidgameRookOn7thBonus = Value(47);
177 const Value EndgameRookOn7thBonus = Value(98);
178 const Value MidgameQueenOn7thBonus = Value(27);
179 const Value EndgameQueenOn7thBonus = Value(54);
181 // Rooks on open files (modified by Joona Kiiski)
182 const Value RookOpenFileBonus = Value(43);
183 const Value RookHalfOpenFileBonus = Value(19);
185 // Penalty for rooks trapped inside a friendly king which has lost the
187 const Value TrappedRookPenalty = Value(180);
189 // Penalty for a bishop on a7/h7 (a2/h2 for black) which is trapped by
191 const Value TrappedBishopA7H7Penalty = Value(300);
193 // Bitboard masks for detecting trapped bishops on a7/h7 (a2/h2 for black)
194 const Bitboard MaskA7H7[2] = {
195 ((1ULL << SQ_A7) | (1ULL << SQ_H7)),
196 ((1ULL << SQ_A2) | (1ULL << SQ_H2))
199 // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
200 // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
201 // happen in Chess960 games.
202 const Value TrappedBishopA1H1Penalty = Value(100);
204 // Bitboard masks for detecting trapped bishops on a1/h1 (a8/h8 for black)
205 const Bitboard MaskA1H1[2] = {
206 ((1ULL << SQ_A1) | (1ULL << SQ_H1)),
207 ((1ULL << SQ_A8) | (1ULL << SQ_H8))
210 // The SpaceMask[color] contains area of the board which is consdered by
211 // the space evaluation. In the middle game, each side is given a bonus
212 // based on how many squares inside this area are safe and available for
213 // friendly minor pieces.
214 const Bitboard SpaceMask[2] = {
215 (1ULL<<SQ_C2) | (1ULL<<SQ_D2) | (1ULL<<SQ_E2) | (1ULL<<SQ_F2) |
216 (1ULL<<SQ_C3) | (1ULL<<SQ_D3) | (1ULL<<SQ_E3) | (1ULL<<SQ_F3) |
217 (1ULL<<SQ_C4) | (1ULL<<SQ_D4) | (1ULL<<SQ_E4) | (1ULL<<SQ_F4),
218 (1ULL<<SQ_C7) | (1ULL<<SQ_D7) | (1ULL<<SQ_E7) | (1ULL<<SQ_F7) |
219 (1ULL<<SQ_C6) | (1ULL<<SQ_D6) | (1ULL<<SQ_E6) | (1ULL<<SQ_F6) |
220 (1ULL<<SQ_C5) | (1ULL<<SQ_D5) | (1ULL<<SQ_E5) | (1ULL<<SQ_F5)
223 /// King safety constants and variables. The king safety scores are taken
224 /// from the array SafetyTable[]. Various little "meta-bonuses" measuring
225 /// the strength of the attack are added up into an integer, which is used
226 /// as an index to SafetyTable[].
228 // Attack weights for each piece type
229 const int QueenAttackWeight = 5;
230 const int RookAttackWeight = 3;
231 const int BishopAttackWeight = 2;
232 const int KnightAttackWeight = 2;
234 // Bonuses for safe checks, initialized from UCI options
235 int QueenContactCheckBonus, DiscoveredCheckBonus;
236 int QueenCheckBonus, RookCheckBonus, BishopCheckBonus, KnightCheckBonus;
238 // Scan for queen contact mates?
239 const bool QueenContactMates = true;
241 // Bonus for having a mate threat, initialized from UCI options
244 // InitKingDanger[] contains bonuses based on the position of the defending
246 const int InitKingDanger[64] = {
247 2, 0, 2, 5, 5, 2, 0, 2,
248 2, 2, 4, 8, 8, 4, 2, 2,
249 7, 10, 12, 12, 12, 12, 10, 7,
250 15, 15, 15, 15, 15, 15, 15, 15,
251 15, 15, 15, 15, 15, 15, 15, 15,
252 15, 15, 15, 15, 15, 15, 15, 15,
253 15, 15, 15, 15, 15, 15, 15, 15,
254 15, 15, 15, 15, 15, 15, 15, 15
257 // SafetyTable[] contains the actual king safety scores. It is initialized
259 Value SafetyTable[100];
261 // Pawn and material hash tables, indexed by the current thread id
262 PawnInfoTable* PawnTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
263 MaterialInfoTable* MaterialTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
265 // Sizes of pawn and material hash tables
266 const int PawnTableSize = 16384;
267 const int MaterialTableSize = 1024;
269 // Function prototypes
270 template<bool HasPopCnt>
271 Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID);
273 template<Color Us, bool HasPopCnt>
274 void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei);
276 template<Color Us, bool HasPopCnt>
277 void evaluate_king(const Position& p, EvalInfo &ei);
279 void evaluate_passed_pawns(const Position &pos, EvalInfo &ei);
280 void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us,
282 void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us,
284 template<bool HasPopCnt>
285 void evaluate_space(const Position &p, Color us, EvalInfo &ei);
286 inline Value apply_weight(Value v, int w);
287 Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]);
289 int compute_weight(int uciWeight, int internalWeight);
290 int weight_option(const std::string& opt, int weight);
300 /// evaluate() is the main evaluation function. It always computes two
301 /// values, an endgame score and a middle game score, and interpolates
302 /// between them based on the remaining material.
303 Value evaluate(const Position& pos, EvalInfo& ei, int threadID) {
305 return CpuHasPOPCNT ? do_evaluate<true>(pos, ei, threadID)
306 : do_evaluate<false>(pos, ei, threadID);
311 template<bool HasPopCnt>
312 Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
315 assert(threadID >= 0 && threadID < THREAD_MAX);
317 memset(&ei, 0, sizeof(EvalInfo));
319 // Initialize by reading the incrementally updated scores included in the
320 // position object (material + piece square tables)
321 ei.mgValue = pos.mg_value();
322 ei.egValue = pos.eg_value();
324 // Probe the material hash table
325 ei.mi = MaterialTable[threadID]->get_material_info(pos);
326 ei.mgValue += ei.mi->material_value();
327 ei.egValue += ei.mi->material_value();
329 // If we have a specialized evaluation function for the current material
330 // configuration, call it and return
331 if (ei.mi->specialized_eval_exists())
332 return ei.mi->evaluate(pos);
334 // After get_material_info() call that modifies them
335 ScaleFactor factor[2];
336 factor[WHITE] = ei.mi->scale_factor(pos, WHITE);
337 factor[BLACK] = ei.mi->scale_factor(pos, BLACK);
339 // Probe the pawn hash table
340 ei.pi = PawnTable[threadID]->get_pawn_info(pos);
341 ei.mgValue += apply_weight(ei.pi->mg_value(), WeightPawnStructureMidgame);
342 ei.egValue += apply_weight(ei.pi->eg_value(), WeightPawnStructureEndgame);
344 // Initialize king attack bitboards and king attack zones for both sides
345 ei.attackedBy[WHITE][KING] = pos.attacks_from<KING>(pos.king_square(WHITE));
346 ei.attackedBy[BLACK][KING] = pos.attacks_from<KING>(pos.king_square(BLACK));
347 ei.kingZone[WHITE] = ei.attackedBy[BLACK][KING] | (ei.attackedBy[BLACK][KING] >> 8);
348 ei.kingZone[BLACK] = ei.attackedBy[WHITE][KING] | (ei.attackedBy[WHITE][KING] << 8);
350 // Initialize pawn attack bitboards for both sides
351 ei.attackedBy[WHITE][PAWN] = ((pos.pieces(PAWN, WHITE) << 9) & ~FileABB) | ((pos.pieces(PAWN, WHITE) << 7) & ~FileHBB);
352 ei.attackedBy[BLACK][PAWN] = ((pos.pieces(PAWN, BLACK) >> 7) & ~FileABB) | ((pos.pieces(PAWN, BLACK) >> 9) & ~FileHBB);
353 Bitboard b1 = ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING];
354 Bitboard b2 = ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING];
356 ei.kingAttackersCount[WHITE] = count_1s_max_15<HasPopCnt>(b1)/2;
359 ei.kingAttackersCount[BLACK] = count_1s_max_15<HasPopCnt>(b2)/2;
362 evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei);
363 evaluate_pieces_of_color<BLACK, HasPopCnt>(pos, ei);
365 // Kings. Kings are evaluated after all other pieces for both sides,
366 // because we need complete attack information for all pieces when computing
367 // the king safety evaluation.
368 evaluate_king<WHITE, HasPopCnt>(pos, ei);
369 evaluate_king<BLACK, HasPopCnt>(pos, ei);
371 // Evaluate passed pawns. We evaluate passed pawns for both sides at once,
372 // because we need to know which side promotes first in positions where
373 // both sides have an unstoppable passed pawn.
374 if (ei.pi->passed_pawns())
375 evaluate_passed_pawns(pos, ei);
377 Phase phase = pos.game_phase();
379 // Middle-game specific evaluation terms
380 if (phase > PHASE_ENDGAME)
382 // Pawn storms in positions with opposite castling.
383 if ( square_file(pos.king_square(WHITE)) >= FILE_E
384 && square_file(pos.king_square(BLACK)) <= FILE_D)
386 ei.mgValue += ei.pi->queenside_storm_value(WHITE)
387 - ei.pi->kingside_storm_value(BLACK);
389 else if ( square_file(pos.king_square(WHITE)) <= FILE_D
390 && square_file(pos.king_square(BLACK)) >= FILE_E)
392 ei.mgValue += ei.pi->kingside_storm_value(WHITE)
393 - ei.pi->queenside_storm_value(BLACK);
395 // Evaluate space for both sides
396 if (ei.mi->space_weight() > 0)
398 evaluate_space<HasPopCnt>(pos, WHITE, ei);
399 evaluate_space<HasPopCnt>(pos, BLACK, ei);
404 ei.mgValue += apply_weight(ei.mgMobility, WeightMobilityMidgame);
405 ei.egValue += apply_weight(ei.egMobility, WeightMobilityEndgame);
407 // If we don't already have an unusual scale factor, check for opposite
408 // colored bishop endgames, and use a lower scale for those
409 if ( phase < PHASE_MIDGAME
410 && pos.opposite_colored_bishops()
411 && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && ei.egValue > Value(0))
412 || (factor[BLACK] == SCALE_FACTOR_NORMAL && ei.egValue < Value(0))))
416 // Only the two bishops ?
417 if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
418 && pos.non_pawn_material(BLACK) == BishopValueMidgame)
420 // Check for KBP vs KB with only a single pawn that is almost
421 // certainly a draw or at least two pawns.
422 bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
423 sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
426 // Endgame with opposite-colored bishops, but also other pieces. Still
427 // a bit drawish, but not as drawish as with only the two bishops.
428 sf = ScaleFactor(50);
430 if (factor[WHITE] == SCALE_FACTOR_NORMAL)
432 if (factor[BLACK] == SCALE_FACTOR_NORMAL)
436 // Interpolate between the middle game and the endgame score, and
438 Color stm = pos.side_to_move();
440 Value v = Sign[stm] * scale_by_game_phase(ei.mgValue, ei.egValue, phase, factor);
442 return (ei.mateThreat[stm] == MOVE_NONE ? v : 8 * QueenValueMidgame - v);
447 /// quick_evaluate() does a very approximate evaluation of the current position.
448 /// It currently considers only material and piece square table scores. Perhaps
449 /// we should add scores from the pawn and material hash tables?
451 Value quick_evaluate(const Position &pos) {
456 ScaleFactor sf[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL};
458 Value mgv = pos.mg_value();
459 Value egv = pos.eg_value();
460 Phase ph = pos.game_phase();
461 Color stm = pos.side_to_move();
463 return Sign[stm] * scale_by_game_phase(mgv, egv, ph, sf);
467 /// init_eval() initializes various tables used by the evaluation function.
469 void init_eval(int threads) {
471 assert(threads <= THREAD_MAX);
473 for (int i = 0; i < THREAD_MAX; i++)
478 delete MaterialTable[i];
480 MaterialTable[i] = NULL;
484 PawnTable[i] = new PawnInfoTable(PawnTableSize);
485 if (!MaterialTable[i])
486 MaterialTable[i] = new MaterialInfoTable(MaterialTableSize);
491 /// quit_eval() releases heap-allocated memory at program termination.
495 for (int i = 0; i < THREAD_MAX; i++)
498 delete MaterialTable[i];
500 MaterialTable[i] = NULL;
505 /// read_weights() reads evaluation weights from the corresponding UCI
508 void read_weights(Color us) {
510 WeightMobilityMidgame = weight_option("Mobility (Middle Game)", WeightMobilityMidgameInternal);
511 WeightMobilityEndgame = weight_option("Mobility (Endgame)", WeightMobilityEndgameInternal);
512 WeightPawnStructureMidgame = weight_option("Pawn Structure (Middle Game)", WeightPawnStructureMidgameInternal);
513 WeightPawnStructureEndgame = weight_option("Pawn Structure (Endgame)", WeightPawnStructureEndgameInternal);
514 WeightPassedPawnsMidgame = weight_option("Passed Pawns (Middle Game)", WeightPassedPawnsMidgameInternal);
515 WeightPassedPawnsEndgame = weight_option("Passed Pawns (Endgame)", WeightPassedPawnsEndgameInternal);
517 Color them = opposite_color(us);
519 WeightKingSafety[us] = weight_option("Cowardice", WeightKingSafetyInternal);
520 WeightKingSafety[them] = weight_option("Aggressiveness", WeightKingOppSafetyInternal);
521 // If running in analysis mode, make sure we use symmetrical king safety.
522 // We do this by replacing both WeightKingSafety[us] and
523 // WeightKingSafety[them] by their average.
524 if (get_option_value_bool("UCI_AnalyseMode")) {
525 WeightKingSafety[us] = (WeightKingSafety[us] + WeightKingSafety[them]) / 2;
526 WeightKingSafety[them] = WeightKingSafety[us];
529 WeightSpace = weight_option("Space", WeightSpaceInternal);
537 // evaluate_mobility() computes mobility and attacks for every piece
539 template<PieceType Piece, Color Us, bool HasPopCnt>
540 int evaluate_mobility(const Position& p, const Bitboard& b, EvalInfo& ei) {
542 const Color Them = (Us == WHITE ? BLACK : WHITE);
543 static const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight };
544 static const Value* MgBonus[] = { 0, 0, MidgameKnightMobilityBonus, MidgameBishopMobilityBonus, MidgameRookMobilityBonus, MidgameQueenMobilityBonus };
545 static const Value* EgBonus[] = { 0, 0, EndgameKnightMobilityBonus, EndgameBishopMobilityBonus, EndgameRookMobilityBonus, EndgameQueenMobilityBonus };
547 // Update attack info
548 ei.attackedBy[Us][Piece] |= b;
551 if (b & ei.kingZone[Us])
553 ei.kingAttackersCount[Us]++;
554 ei.kingAttackersWeight[Us] += AttackWeight[Piece];
555 Bitboard bb = (b & ei.attackedBy[Them][KING]);
557 ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15<HasPopCnt>(bb);
560 // Remove squares protected by enemy pawns
561 Bitboard bb = (b & ~ei.attackedBy[Them][PAWN]);
564 int mob = (Piece != QUEEN ? count_1s_max_15<HasPopCnt>(bb & ~p.pieces_of_color(Us))
565 : count_1s<HasPopCnt>(bb & ~p.pieces_of_color(Us)));
567 ei.mgMobility += Sign[Us] * MgBonus[Piece][mob];
568 ei.egMobility += Sign[Us] * EgBonus[Piece][mob];
573 // evaluate_outposts() evaluates bishop and knight outposts squares
575 template<PieceType Piece, Color Us>
576 void evaluate_outposts(const Position& p, EvalInfo& ei, Square s) {
578 const Color Them = (Us == WHITE ? BLACK : WHITE);
580 // Initial bonus based on square
581 Value bonus = (Piece == BISHOP ? BishopOutpostBonus[relative_square(Us, s)]
582 : KnightOutpostBonus[relative_square(Us, s)]);
584 // Increase bonus if supported by pawn, especially if the opponent has
585 // no minor piece which can exchange the outpost piece
586 if (bonus && (p.attacks_from<PAWN>(s, Them) & p.pieces(PAWN, Us)))
588 if ( p.pieces(KNIGHT, Them) == EmptyBoardBB
589 && (SquaresByColorBB[square_color(s)] & p.pieces(BISHOP, Them)) == EmptyBoardBB)
590 bonus += bonus + bonus / 2;
594 ei.mgValue += Sign[Us] * bonus;
595 ei.egValue += Sign[Us] * bonus;
599 // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given
602 template<PieceType Piece, Color Us, bool HasPopCnt>
603 void evaluate_pieces(const Position& pos, EvalInfo& ei) {
610 const Color Them = (Us == WHITE ? BLACK : WHITE);
611 const Square* ptr = pos.piece_list_begin(Us, Piece);
613 while ((s = *ptr++) != SQ_NONE)
615 if (Piece == KNIGHT || Piece == QUEEN)
616 b = pos.attacks_from<Piece>(s);
617 else if (Piece == BISHOP)
618 b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us));
619 else if (Piece == ROOK)
620 b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us));
624 // Attacks and mobility
625 mob = evaluate_mobility<Piece, Us, HasPopCnt>(pos, b, ei);
627 // Bishop and knight outposts squares
628 if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Them))
629 evaluate_outposts<Piece, Us>(pos, ei, s);
631 // Special patterns: trapped bishops on a7/h7/a2/h2
632 // and trapped bishops on a1/h1/a8/h8 in Chess960.
635 if (bit_is_set(MaskA7H7[Us], s))
636 evaluate_trapped_bishop_a7h7(pos, s, Us, ei);
638 if (Chess960 && bit_is_set(MaskA1H1[Us], s))
639 evaluate_trapped_bishop_a1h1(pos, s, Us, ei);
642 if (Piece == ROOK || Piece == QUEEN)
644 // Queen or rook on 7th rank
645 if ( relative_rank(Us, s) == RANK_7
646 && relative_rank(Us, pos.king_square(Them)) == RANK_8)
648 ei.mgValue += Sign[Us] * (Piece == ROOK ? MidgameRookOn7thBonus : MidgameQueenOn7thBonus);
649 ei.egValue += Sign[Us] * (Piece == ROOK ? EndgameRookOn7thBonus : EndgameQueenOn7thBonus);
653 // Special extra evaluation for rooks
656 // Open and half-open files
658 if (ei.pi->file_is_half_open(Us, f))
660 if (ei.pi->file_is_half_open(Them, f))
662 ei.mgValue += Sign[Us] * RookOpenFileBonus;
663 ei.egValue += Sign[Us] * RookOpenFileBonus;
667 ei.mgValue += Sign[Us] * RookHalfOpenFileBonus;
668 ei.egValue += Sign[Us] * RookHalfOpenFileBonus;
672 // Penalize rooks which are trapped inside a king. Penalize more if
673 // king has lost right to castle.
674 if (mob > 6 || ei.pi->file_is_half_open(Us, f))
677 ksq = pos.king_square(Us);
679 if ( square_file(ksq) >= FILE_E
680 && square_file(s) > square_file(ksq)
681 && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
683 // Is there a half-open file between the king and the edge of the board?
684 if (!ei.pi->has_open_file_to_right(Us, square_file(ksq)))
685 ei.mgValue -= pos.can_castle(Us)? Sign[Us] * ((TrappedRookPenalty - mob * 16) / 2)
686 : Sign[Us] * (TrappedRookPenalty - mob * 16);
688 else if ( square_file(ksq) <= FILE_D
689 && square_file(s) < square_file(ksq)
690 && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
692 // Is there a half-open file between the king and the edge of the board?
693 if (!ei.pi->has_open_file_to_left(Us, square_file(ksq)))
694 ei.mgValue -= pos.can_castle(Us)? Sign[Us] * ((TrappedRookPenalty - mob * 16) / 2)
695 : Sign[Us] * (TrappedRookPenalty - mob * 16);
701 // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the pieces of a given
704 template<Color Us, bool HasPopCnt>
705 void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei) {
707 evaluate_pieces<KNIGHT, Us, HasPopCnt>(pos, ei);
708 evaluate_pieces<BISHOP, Us, HasPopCnt>(pos, ei);
709 evaluate_pieces<ROOK, Us, HasPopCnt>(pos, ei);
710 evaluate_pieces<QUEEN, Us, HasPopCnt>(pos, ei);
712 // Sum up all attacked squares
713 ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
714 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
715 | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
718 // evaluate_king<>() assigns bonuses and penalties to a king of a given color.
720 template<Color Us, bool HasPopCnt>
721 void evaluate_king(const Position& p, EvalInfo& ei) {
723 const Color Them = (Us == WHITE ? BLACK : WHITE);
724 const Square s = p.king_square(Us);
728 if (relative_rank(Us, s) <= RANK_4)
730 shelter = ei.pi->get_king_shelter(p, Us, s);
731 ei.mgValue += Sign[Us] * Value(shelter);
734 // King safety. This is quite complicated, and is almost certainly far
735 // from optimally tuned.
736 if ( p.piece_count(Them, QUEEN) >= 1
737 && ei.kingAttackersCount[Them] >= 2
738 && p.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame
739 && ei.kingAdjacentZoneAttacksCount[Them])
741 // Is it the attackers turn to move?
742 bool sente = (Them == p.side_to_move());
744 // Find the attacked squares around the king which has no defenders
745 // apart from the king itself
746 Bitboard undefended =
747 ei.attacked_by(Them) & ~ei.attacked_by(Us, PAWN)
748 & ~ei.attacked_by(Us, KNIGHT) & ~ei.attacked_by(Us, BISHOP)
749 & ~ei.attacked_by(Us, ROOK) & ~ei.attacked_by(Us, QUEEN)
750 & ei.attacked_by(Us, KING);
752 Bitboard occ = p.occupied_squares(), b, b2;
754 // Initialize the 'attackUnits' variable, which is used later on as an
755 // index to the SafetyTable[] array. The initial value is based on the
756 // number and types of the attacking pieces, the number of attacked and
757 // undefended squares around the king, the square of the king, and the
758 // quality of the pawn shelter.
760 Min((ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2, 25)
761 + (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15<HasPopCnt>(undefended)) * 3
762 + InitKingDanger[relative_square(Us, s)] - (shelter >> 5);
764 // Analyse safe queen contact checks
765 b = undefended & ei.attacked_by(Them, QUEEN) & ~p.pieces_of_color(Them);
768 Bitboard attackedByOthers =
769 ei.attacked_by(Them, PAWN) | ei.attacked_by(Them, KNIGHT)
770 | ei.attacked_by(Them, BISHOP) | ei.attacked_by(Them, ROOK);
772 b &= attackedByOthers;
775 // The bitboard b now contains the squares available for safe queen
777 int count = count_1s_max_15<HasPopCnt>(b);
778 attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1);
780 // Is there a mate threat?
781 if (QueenContactMates && !p.is_check())
783 Bitboard escapeSquares =
784 p.attacks_from<KING>(s) & ~p.pieces_of_color(Us) & ~attackedByOthers;
788 Square from, to = pop_1st_bit(&b);
789 if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[s])))
791 // We have a mate, unless the queen is pinned or there
792 // is an X-ray attack through the queen.
793 for (int i = 0; i < p.piece_count(Them, QUEEN); i++)
795 from = p.piece_list(Them, QUEEN, i);
796 if ( bit_is_set(p.attacks_from<QUEEN>(from), to)
797 && !bit_is_set(p.pinned_pieces(Them), from)
798 && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & p.pieces(ROOK, QUEEN, Us))
799 && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & p.pieces(BISHOP, QUEEN, Us)))
801 ei.mateThreat[Them] = make_move(from, to);
809 // Analyse safe distance checks
810 if (QueenCheckBonus > 0 || RookCheckBonus > 0)
812 b = p.attacks_from<ROOK>(s) & ~p.pieces_of_color(Them) & ~ei.attacked_by(Us);
815 b2 = b & ei.attacked_by(Them, QUEEN);
817 attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b2);
820 b2 = b & ei.attacked_by(Them, ROOK);
822 attackUnits += RookCheckBonus * count_1s_max_15<HasPopCnt>(b2);
824 if (QueenCheckBonus > 0 || BishopCheckBonus > 0)
826 b = p.attacks_from<BISHOP>(s) & ~p.pieces_of_color(Them) & ~ei.attacked_by(Us);
829 b2 = b & ei.attacked_by(Them, QUEEN);
831 attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b2);
834 b2 = b & ei.attacked_by(Them, BISHOP);
836 attackUnits += BishopCheckBonus * count_1s_max_15<HasPopCnt>(b2);
838 if (KnightCheckBonus > 0)
840 b = p.attacks_from<KNIGHT>(s) & ~p.pieces_of_color(Them) & ~ei.attacked_by(Us);
843 b2 = b & ei.attacked_by(Them, KNIGHT);
845 attackUnits += KnightCheckBonus * count_1s_max_15<HasPopCnt>(b2);
848 // Analyse discovered checks (only for non-pawns right now, consider
849 // adding pawns later).
850 if (DiscoveredCheckBonus)
852 b = p.discovered_check_candidates(Them) & ~p.pieces(PAWN);
854 attackUnits += DiscoveredCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
857 // Has a mate threat been found? We don't do anything here if the
858 // side with the mating move is the side to move, because in that
859 // case the mating side will get a huge bonus at the end of the main
860 // evaluation function instead.
861 if (ei.mateThreat[Them] != MOVE_NONE)
862 attackUnits += MateThreatBonus;
864 // Ensure that attackUnits is between 0 and 99, in order to avoid array
865 // out of bounds errors:
869 if (attackUnits >= 100)
872 // Finally, extract the king safety score from the SafetyTable[] array.
873 // Add the score to the evaluation, and also to ei.futilityMargin. The
874 // reason for adding the king safety score to the futility margin is
875 // that the king safety scores can sometimes be very big, and that
876 // capturing a single attacking piece can therefore result in a score
877 // change far bigger than the value of the captured piece.
878 Value v = apply_weight(SafetyTable[attackUnits], WeightKingSafety[Us]);
880 ei.mgValue -= Sign[Us] * v;
882 if (Us == p.side_to_move())
883 ei.futilityMargin += v;
888 // evaluate_passed_pawns() evaluates the passed pawns for both sides.
890 void evaluate_passed_pawns(const Position &pos, EvalInfo &ei) {
892 bool hasUnstoppable[2] = {false, false};
893 int movesToGo[2] = {100, 100};
895 for (Color us = WHITE; us <= BLACK; us++)
897 Color them = opposite_color(us);
898 Square ourKingSq = pos.king_square(us);
899 Square theirKingSq = pos.king_square(them);
900 Bitboard b = ei.pi->passed_pawns() & pos.pieces(PAWN, us), b2, b3, b4;
904 Square s = pop_1st_bit(&b);
906 assert(pos.piece_on(s) == piece_of_color_and_type(us, PAWN));
907 assert(pos.pawn_is_passed(us, s));
909 int r = int(relative_rank(us, s) - RANK_2);
910 int tr = Max(0, r * (r - 1));
911 Square blockSq = s + pawn_push(us);
913 // Base bonus based on rank
914 Value mbonus = Value(20 * tr);
915 Value ebonus = Value(10 + r * r * 10);
917 // Adjust bonus based on king proximity
920 ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr);
921 ebonus -= Value(square_distance(ourKingSq, blockSq + pawn_push(us)) * 1 * tr);
922 ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr);
924 // If the pawn is free to advance, increase bonus
925 if (pos.square_is_empty(blockSq))
927 b2 = squares_in_front_of(us, s);
928 b3 = b2 & ei.attacked_by(them);
929 b4 = b2 & ei.attacked_by(us);
931 // If there is an enemy rook or queen attacking the pawn from behind,
932 // add all X-ray attacks by the rook or queen.
933 if ( bit_is_set(ei.attacked_by(them,ROOK) | ei.attacked_by(them,QUEEN),s)
934 && (squares_behind(us, s) & pos.pieces(ROOK, QUEEN, them)))
937 // Squares attacked or occupied by enemy pieces
938 b3 |= (b2 & pos.pieces_of_color(them));
940 // There are no enemy pawns in the pawn's path
941 assert((b2 & pos.pieces(PAWN, them)) == EmptyBoardBB);
943 // Are any of the squares in the pawn's path attacked or occupied by the enemy?
944 if (b3 == EmptyBoardBB)
945 // No enemy attacks or pieces, huge bonus!
946 ebonus += Value(tr * (b2 == b4 ? 17 : 15));
948 // OK, there are enemy attacks or pieces (but not pawns). Are those
949 // squares which are attacked by the enemy also attacked by us?
950 // If yes, big bonus (but smaller than when there are no enemy attacks),
951 // if no, somewhat smaller bonus.
952 ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8));
954 // At last, add a small bonus when there are no *friendly* pieces
955 // in the pawn's path.
956 if ((b2 & pos.pieces_of_color(us)) == EmptyBoardBB)
961 // If the pawn is supported by a friendly pawn, increase bonus
962 b2 = pos.pieces(PAWN, us) & neighboring_files_bb(s);
964 ebonus += Value(r * 20);
965 else if (pos.attacks_from<PAWN>(s, them) & b2)
966 ebonus += Value(r * 12);
968 // If the other side has only a king, check whether the pawn is
970 if (pos.non_pawn_material(them) == Value(0))
975 qsq = relative_square(us, make_square(square_file(s), RANK_8));
976 d = square_distance(s, qsq)
977 - square_distance(theirKingSq, qsq)
978 + (us != pos.side_to_move());
982 int mtg = RANK_8 - relative_rank(us, s);
983 int blockerCount = count_1s_max_15(squares_in_front_of(us,s) & pos.occupied_squares());
988 hasUnstoppable[us] = true;
989 movesToGo[us] = Min(movesToGo[us], mtg);
993 // Rook pawns are a special case: They are sometimes worse, and
994 // sometimes better than other passed pawns. It is difficult to find
995 // good rules for determining whether they are good or bad. For now,
996 // we try the following: Increase the value for rook pawns if the
997 // other side has no pieces apart from a knight, and decrease the
998 // value if the other side has a rook or queen.
999 if (square_file(s) == FILE_A || square_file(s) == FILE_H)
1001 if ( pos.non_pawn_material(them) <= KnightValueMidgame
1002 && pos.piece_count(them, KNIGHT) <= 1)
1003 ebonus += ebonus / 4;
1004 else if (pos.pieces(ROOK, QUEEN, them))
1005 ebonus -= ebonus / 4;
1008 // Add the scores for this pawn to the middle game and endgame eval.
1009 ei.mgValue += apply_weight(Sign[us] * mbonus, WeightPassedPawnsMidgame);
1010 ei.egValue += apply_weight(Sign[us] * ebonus, WeightPassedPawnsEndgame);
1014 // Does either side have an unstoppable passed pawn?
1015 if (hasUnstoppable[WHITE] && !hasUnstoppable[BLACK])
1016 ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]);
1017 else if (hasUnstoppable[BLACK] && !hasUnstoppable[WHITE])
1018 ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]);
1019 else if (hasUnstoppable[BLACK] && hasUnstoppable[WHITE])
1021 // Both sides have unstoppable pawns! Try to find out who queens
1022 // first. We begin by transforming 'movesToGo' to the number of
1023 // plies until the pawn queens for both sides.
1024 movesToGo[WHITE] *= 2;
1025 movesToGo[BLACK] *= 2;
1026 movesToGo[pos.side_to_move()]--;
1028 // If one side queens at least three plies before the other, that
1030 if (movesToGo[WHITE] <= movesToGo[BLACK] - 3)
1031 ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2));
1032 else if(movesToGo[BLACK] <= movesToGo[WHITE] - 3)
1033 ei.egValue -= UnstoppablePawnValue - Value(0x40 * (movesToGo[BLACK]/2));
1035 // We could also add some rules about the situation when one side
1036 // queens exactly one ply before the other: Does the first queen
1037 // check the opponent's king, or attack the opponent's queening square?
1038 // This is slightly tricky to get right, because it is possible that
1039 // the opponent's king has moved somewhere before the first pawn queens.
1044 // evaluate_trapped_bishop_a7h7() determines whether a bishop on a7/h7
1045 // (a2/h2 for black) is trapped by enemy pawns, and assigns a penalty
1048 void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us,
1050 assert(square_is_ok(s));
1051 assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP));
1053 Square b6 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B6 : SQ_G6);
1054 Square b8 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B8 : SQ_G8);
1056 if ( pos.piece_on(b6) == piece_of_color_and_type(opposite_color(us), PAWN)
1057 && pos.see(s, b6) < 0
1058 && pos.see(s, b8) < 0)
1060 ei.mgValue -= Sign[us] * TrappedBishopA7H7Penalty;
1061 ei.egValue -= Sign[us] * TrappedBishopA7H7Penalty;
1066 // evaluate_trapped_bishop_a1h1() determines whether a bishop on a1/h1
1067 // (a8/h8 for black) is trapped by a friendly pawn on b2/g2 (b7/g7 for
1068 // black), and assigns a penalty if it is. This pattern can obviously
1069 // only occur in Chess960 games.
1071 void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us,
1073 Piece pawn = piece_of_color_and_type(us, PAWN);
1077 assert(square_is_ok(s));
1078 assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP));
1080 if (square_file(s) == FILE_A)
1082 b2 = relative_square(us, SQ_B2);
1083 b3 = relative_square(us, SQ_B3);
1084 c3 = relative_square(us, SQ_C3);
1088 b2 = relative_square(us, SQ_G2);
1089 b3 = relative_square(us, SQ_G3);
1090 c3 = relative_square(us, SQ_F3);
1093 if (pos.piece_on(b2) == pawn)
1097 if (!pos.square_is_empty(b3))
1098 penalty = 2*TrappedBishopA1H1Penalty;
1099 else if (pos.piece_on(c3) == pawn)
1100 penalty = TrappedBishopA1H1Penalty;
1102 penalty = TrappedBishopA1H1Penalty / 2;
1104 ei.mgValue -= Sign[us] * penalty;
1105 ei.egValue -= Sign[us] * penalty;
1110 // evaluate_space() computes the space evaluation for a given side. The
1111 // space evaluation is a simple bonus based on the number of safe squares
1112 // available for minor pieces on the central four files on ranks 2--4. Safe
1113 // squares one, two or three squares behind a friendly pawn are counted
1114 // twice. Finally, the space bonus is scaled by a weight taken from the
1115 // material hash table.
1116 template<bool HasPopCnt>
1117 void evaluate_space(const Position &pos, Color us, EvalInfo &ei) {
1119 Color them = opposite_color(us);
1121 // Find the safe squares for our pieces inside the area defined by
1122 // SpaceMask[us]. A square is unsafe it is attacked by an enemy
1123 // pawn, or if it is undefended and attacked by an enemy piece.
1125 Bitboard safeSquares = SpaceMask[us]
1126 & ~pos.pieces(PAWN, us)
1127 & ~ei.attacked_by(them, PAWN)
1128 & ~(~ei.attacked_by(us) & ei.attacked_by(them));
1130 // Find all squares which are at most three squares behind some friendly
1132 Bitboard behindFriendlyPawns = pos.pieces(PAWN, us);
1135 behindFriendlyPawns |= (behindFriendlyPawns >> 8);
1136 behindFriendlyPawns |= (behindFriendlyPawns >> 16);
1140 behindFriendlyPawns |= (behindFriendlyPawns << 8);
1141 behindFriendlyPawns |= (behindFriendlyPawns << 16);
1144 int space = count_1s_max_15<HasPopCnt>(safeSquares)
1145 + count_1s_max_15<HasPopCnt>(behindFriendlyPawns & safeSquares);
1147 ei.mgValue += Sign[us] * apply_weight(Value(space * ei.mi->space_weight()), WeightSpace);
1151 // apply_weight() applies an evaluation weight to a value
1153 inline Value apply_weight(Value v, int w) {
1154 return (v*w) / 0x100;
1158 // scale_by_game_phase() interpolates between a middle game and an endgame
1159 // score, based on game phase. It also scales the return value by a
1160 // ScaleFactor array.
1162 Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]) {
1164 assert(mv > -VALUE_INFINITE && mv < VALUE_INFINITE);
1165 assert(ev > -VALUE_INFINITE && ev < VALUE_INFINITE);
1166 assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
1168 ev = apply_scale_factor(ev, sf[(ev > Value(0) ? WHITE : BLACK)]);
1170 Value result = Value(int((mv * ph + ev * (128 - ph)) / 128));
1171 return Value(int(result) & ~(GrainSize - 1));
1175 // compute_weight() computes the value of an evaluation weight, by combining
1176 // an UCI-configurable weight with an internal weight.
1178 int compute_weight(int uciWeight, int internalWeight) {
1180 uciWeight = (uciWeight * 0x100) / 100;
1181 return (uciWeight * internalWeight) / 0x100;
1185 // helper used in read_weights()
1186 int weight_option(const std::string& opt, int weight) {
1188 return compute_weight(get_option_value_int(opt), weight);
1192 // init_safety() initizes the king safety evaluation, based on UCI
1193 // parameters. It is called from read_weights().
1195 void init_safety() {
1197 QueenContactCheckBonus = get_option_value_int("Queen Contact Check Bonus");
1198 QueenCheckBonus = get_option_value_int("Queen Check Bonus");
1199 RookCheckBonus = get_option_value_int("Rook Check Bonus");
1200 BishopCheckBonus = get_option_value_int("Bishop Check Bonus");
1201 KnightCheckBonus = get_option_value_int("Knight Check Bonus");
1202 DiscoveredCheckBonus = get_option_value_int("Discovered Check Bonus");
1203 MateThreatBonus = get_option_value_int("Mate Threat Bonus");
1205 int maxSlope = get_option_value_int("King Safety Max Slope");
1206 int peak = get_option_value_int("King Safety Max Value") * 256 / 100;
1207 double a = get_option_value_int("King Safety Coefficient") / 100.0;
1208 double b = get_option_value_int("King Safety X Intercept");
1209 bool quad = (get_option_value_string("King Safety Curve") == "Quadratic");
1210 bool linear = (get_option_value_string("King Safety Curve") == "Linear");
1212 for (int i = 0; i < 100; i++)
1215 SafetyTable[i] = Value(0);
1217 SafetyTable[i] = Value((int)(a * (i - b) * (i - b)));
1219 SafetyTable[i] = Value((int)(100 * a * (i - b)));
1222 for (int i = 0; i < 100; i++)
1224 if (SafetyTable[i+1] - SafetyTable[i] > maxSlope)
1225 for (int j = i + 1; j < 100; j++)
1226 SafetyTable[j] = SafetyTable[j-1] + Value(maxSlope);
1228 if (SafetyTable[i] > Value(peak))
1229 SafetyTable[i] = Value(peak);