along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
-////
-//// Includes
-////
-
#include <cassert>
#include <cstring>
#include <map>
using namespace std;
-
-////
-//// Local definitions
-////
-
namespace {
// Values modified by Joona Kiiski
&& pos.non_pawn_material(Us) >= RookValueMidgame;
}
- template<Color Us> bool is_KBPsK(const Position& pos) {
+ template<Color Us> bool is_KBPsKs(const Position& pos) {
return pos.non_pawn_material(Us) == BishopValueMidgame
&& pos.piece_count(Us, BISHOP) == 1
&& pos.piece_count(Us, PAWN) >= 1;
}
-////
-//// Classes
-////
-
/// EndgameFunctions class stores endgame evaluation and scaling functions
/// in two std::map. Because STL library is not guaranteed to be thread
/// safe even for read access, the maps, although with identical content,
template<> const SFMap& EndgameFunctions::get<SF>() const { return maps.second; }
-////
-//// Functions
-////
+/// MaterialInfoTable c'tor and d'tor allocate and free the space for EndgameFunctions
MaterialInfoTable::MaterialInfoTable() { funcs = new EndgameFunctions(); }
MaterialInfoTable::~MaterialInfoTable() { delete funcs; }
-/// MaterialInfoTable::game_phase() calculates the phase given the current
-/// position. Because the phase is strictly a function of the material, it
-/// is stored in MaterialInfo.
-
-Phase MaterialInfoTable::game_phase(const Position& pos) {
-
- Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK);
-
- if (npm >= MidgameLimit)
- return PHASE_MIDGAME;
-
- if (npm <= EndgameLimit)
- return PHASE_ENDGAME;
-
- return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
-}
/// MaterialInfoTable::get_material_info() takes a position object as input,
/// computes or looks up a MaterialInfo object, and returns a pointer to it.
/// is stored there, so we don't have to recompute everything when the
/// same material configuration occurs again.
-MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
+MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) const {
Key key = pos.get_material_key();
MaterialInfo* mi = find(key);
if (mi->key == key)
return mi;
- // Clear the MaterialInfo object, and set its key
+ // Initialize MaterialInfo entry
memset(mi, 0, sizeof(MaterialInfo));
- mi->factor[WHITE] = mi->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
mi->key = key;
+ mi->factor[WHITE] = mi->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
// Store game phase
mi->gamePhase = MaterialInfoTable::game_phase(pos);
if ((mi->evaluationFunction = funcs->get<EF>(key)) != NULL)
return mi;
- if (is_KXK<WHITE>(pos) || is_KXK<BLACK>(pos))
+ if (is_KXK<WHITE>(pos))
{
- mi->evaluationFunction = is_KXK<WHITE>(pos) ? &EvaluateKXK[WHITE] : &EvaluateKXK[BLACK];
+ mi->evaluationFunction = &EvaluateKXK[WHITE];
return mi;
}
- if ( pos.pieces(PAWN) == EmptyBoardBB
- && pos.pieces(ROOK) == EmptyBoardBB
- && pos.pieces(QUEEN) == EmptyBoardBB)
+ if (is_KXK<BLACK>(pos))
+ {
+ mi->evaluationFunction = &EvaluateKXK[BLACK];
+ return mi;
+ }
+
+ if (!pos.pieces(PAWN) && !pos.pieces(ROOK) && !pos.pieces(QUEEN))
{
// Minor piece endgame with at least one minor piece per side and
// no pawns. Note that the case KmmK is already handled by KXK.
// Generic scaling functions that refer to more then one material
// distribution. Should be probed after the specialized ones.
// Note that these ones don't return after setting the function.
- if (is_KBPsK<WHITE>(pos))
+ if (is_KBPsKs<WHITE>(pos))
mi->scalingFunction[WHITE] = &ScaleKBPsK[WHITE];
- if (is_KBPsK<BLACK>(pos))
+ if (is_KBPsKs<BLACK>(pos))
mi->scalingFunction[BLACK] = &ScaleKBPsK[BLACK];
if (is_KQKRPs<WHITE>(pos))
}
}
+ // No pawns makes it difficult to win, even with a material advantage
+ for (Color c = WHITE; c <= BLACK; c++)
+ if ( pos.piece_count(c, PAWN) == 0
+ && pos.non_pawn_material(c) - pos.non_pawn_material(opposite_color(c)) <= BishopValueMidgame)
+ {
+ if ( pos.non_pawn_material(c) == pos.non_pawn_material(opposite_color(c))
+ || pos.non_pawn_material(c) < RookValueMidgame)
+ mi->factor[c] = 0;
+ else
+ {
+ switch (pos.piece_count(c, BISHOP)) {
+ case 2:
+ mi->factor[c] = 32;
+ break;
+ case 1:
+ mi->factor[c] = 12;
+ break;
+ case 0:
+ mi->factor[c] = 6;
+ break;
+ }
+ }
+ }
+
// Compute the space weight
if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >=
2*QueenValueMidgame + 4*RookValueMidgame + 2*KnightValueMidgame)
{
int minorPieceCount = pos.piece_count(WHITE, KNIGHT)
- + pos.piece_count(BLACK, KNIGHT)
+ pos.piece_count(WHITE, BISHOP)
+ + pos.piece_count(BLACK, KNIGHT)
+ pos.piece_count(BLACK, BISHOP);
mi->spaceWeight = minorPieceCount * minorPieceCount;
}
- // Evaluate the material balance
+ // Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder
+ // for the bishop pair "extended piece", this allow us to be more flexible
+ // in defining bishop pair bonuses.
const int pieceCount[2][8] = {
{ pos.piece_count(WHITE, BISHOP) > 1, pos.piece_count(WHITE, PAWN), pos.piece_count(WHITE, KNIGHT),
pos.piece_count(WHITE, BISHOP), pos.piece_count(WHITE, ROOK), pos.piece_count(WHITE, QUEEN) },
{ pos.piece_count(BLACK, BISHOP) > 1, pos.piece_count(BLACK, PAWN), pos.piece_count(BLACK, KNIGHT),
pos.piece_count(BLACK, BISHOP), pos.piece_count(BLACK, ROOK), pos.piece_count(BLACK, QUEEN) } };
- Color c, them;
- int sign, pt1, pt2, pc;
- int v, vv, matValue = 0;
+ mi->value = (int16_t)(imbalance<WHITE>(pieceCount) - imbalance<BLACK>(pieceCount)) / 16;
+ return mi;
+}
- for (c = WHITE, sign = 1; c <= BLACK; c++, sign = -sign)
- {
- // No pawns makes it difficult to win, even with a material advantage
- if ( pos.piece_count(c, PAWN) == 0
- && pos.non_pawn_material(c) - pos.non_pawn_material(opposite_color(c)) <= BishopValueMidgame)
- {
- if ( pos.non_pawn_material(c) == pos.non_pawn_material(opposite_color(c))
- || pos.non_pawn_material(c) < RookValueMidgame)
- mi->factor[c] = 0;
- else
- {
- switch (pos.piece_count(c, BISHOP)) {
- case 2:
- mi->factor[c] = 32;
- break;
- case 1:
- mi->factor[c] = 12;
- break;
- case 0:
- mi->factor[c] = 6;
- break;
- }
- }
- }
- // Redundancy of major pieces, formula based on Kaufman's paper
- // "The Evaluation of Material Imbalances in Chess"
- // http://mywebpages.comcast.net/danheisman/Articles/evaluation_of_material_imbalance.htm
- if (pieceCount[c][ROOK] >= 1)
- matValue -= sign * ((pieceCount[c][ROOK] - 1) * RedundantRookPenalty + pieceCount[c][QUEEN] * RedundantQueenPenalty);
+/// MaterialInfoTable::imbalance() calculates imbalance comparing piece count of each
+/// piece type for both colors.
- them = opposite_color(c);
- v = 0;
+template<Color Us>
+int MaterialInfoTable::imbalance(const int pieceCount[][8]) {
- // Second-degree polynomial material imbalance by Tord Romstad
- //
- // We use PIECE_TYPE_NONE as a place holder for the bishop pair "extended piece",
- // this allow us to be more flexible in defining bishop pair bonuses.
- for (pt1 = PIECE_TYPE_NONE; pt1 <= QUEEN; pt1++)
- {
- pc = pieceCount[c][pt1];
- if (!pc)
- continue;
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
- vv = LinearCoefficients[pt1];
+ int pt1, pt2, pc, vv;
+ int value = 0;
- for (pt2 = PIECE_TYPE_NONE; pt2 <= pt1; pt2++)
- vv += pieceCount[c][pt2] * QuadraticCoefficientsSameColor[pt1][pt2]
- + pieceCount[them][pt2] * QuadraticCoefficientsOppositeColor[pt1][pt2];
+ // Redundancy of major pieces, formula based on Kaufman's paper
+ // "The Evaluation of Material Imbalances in Chess"
+ if (pieceCount[Us][ROOK] > 0)
+ value -= RedundantRookPenalty * (pieceCount[Us][ROOK] - 1)
+ + RedundantQueenPenalty * pieceCount[Us][QUEEN];
- v += pc * vv;
- }
- matValue += sign * v;
+ // Second-degree polynomial material imbalance by Tord Romstad
+ for (pt1 = PIECE_TYPE_NONE; pt1 <= QUEEN; pt1++)
+ {
+ pc = pieceCount[Us][pt1];
+ if (!pc)
+ continue;
+
+ vv = LinearCoefficients[pt1];
+
+ for (pt2 = PIECE_TYPE_NONE; pt2 <= pt1; pt2++)
+ vv += QuadraticCoefficientsSameColor[pt1][pt2] * pieceCount[Us][pt2]
+ + QuadraticCoefficientsOppositeColor[pt1][pt2] * pieceCount[Them][pt2];
+
+ value += pc * vv;
}
- mi->value = (int16_t)(matValue / 16);
- return mi;
+ return value;
+}
+
+
+/// MaterialInfoTable::game_phase() calculates the phase given the current
+/// position. Because the phase is strictly a function of the material, it
+/// is stored in MaterialInfo.
+
+Phase MaterialInfoTable::game_phase(const Position& pos) {
+
+ Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK);
+
+ if (npm >= MidgameLimit)
+ return PHASE_MIDGAME;
+
+ if (npm <= EndgameLimit)
+ return PHASE_ENDGAME;
+
+ return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
}
projects / stockfish / commitdiff