mirror of
https://github.com/sockspls/badfish
synced 2025-07-11 19:49:14 +00:00
152f3b13b7
It is like a never finished painting. Everyday a little touch more. But this time it is very little ;-) No functional change. Signed-off-by: Marco Costalba <mcostalba@gmail.com>
422 lines
14 KiB
C++
422 lines
14 KiB
C++
/*
|
|
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
|
|
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
|
|
Copyright (C) 2008-2009 Marco Costalba
|
|
|
|
Stockfish is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
Stockfish is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
|
|
////
|
|
//// Includes
|
|
////
|
|
|
|
#include <cassert>
|
|
#include <sstream>
|
|
#include <map>
|
|
|
|
#include "material.h"
|
|
|
|
using namespace std;
|
|
|
|
////
|
|
//// Local definitions
|
|
////
|
|
|
|
namespace {
|
|
|
|
// Values modified by Joona Kiiski
|
|
const Value BishopPairMidgameBonus = Value(109);
|
|
const Value BishopPairEndgameBonus = Value(97);
|
|
|
|
// Polynomial material balance parameters
|
|
const Value RedundantQueenPenalty = Value(358);
|
|
const Value RedundantRookPenalty = Value(536);
|
|
const int LinearCoefficients[6] = { 1740, -146, -1246, -197, 206, -7 };
|
|
|
|
const int QuadraticCoefficientsSameColor[][6] = {
|
|
{ 0, 0, 0, 0, 0, 0 }, { 31, -4, 0, 0, 0, 0 }, { 14, 267, -21, 0, 0, 0 },
|
|
{ 0, 7, -26, 0, 0, 0 }, { -3, -1, 69, 162, 80, 0 }, { 40, 27, 119, 174, -64, -49 } };
|
|
|
|
const int QuadraticCoefficientsOppositeColor[][6] = {
|
|
{ 0, 0, 0, 0, 0, 0 }, { -9, 0, 0, 0, 0, 0 }, { 49, 32, 0, 0, 0, 0 },
|
|
{ -25, 19, -5, 0, 0, 0 }, { 97, -6, 39, -88, 0, 0 }, { 77, 69, -42, 104, 116, 0 } };
|
|
|
|
// Unmapped endgame evaluation and scaling functions, these
|
|
// are accessed direcly and not through the function maps.
|
|
EvaluationFunction<KmmKm> EvaluateKmmKm(WHITE);
|
|
EvaluationFunction<KXK> EvaluateKXK(WHITE), EvaluateKKX(BLACK);
|
|
ScalingFunction<KBPK> ScaleKBPK(WHITE), ScaleKKBP(BLACK);
|
|
ScalingFunction<KQKRP> ScaleKQKRP(WHITE), ScaleKRPKQ(BLACK);
|
|
ScalingFunction<KPsK> ScaleKPsK(WHITE), ScaleKKPs(BLACK);
|
|
ScalingFunction<KPKP> ScaleKPKPw(WHITE), ScaleKPKPb(BLACK);
|
|
|
|
Key KNNKMaterialKey, KKNNMaterialKey;
|
|
}
|
|
|
|
|
|
////
|
|
//// Classes
|
|
////
|
|
|
|
typedef EndgameEvaluationFunctionBase EF;
|
|
typedef EndgameScalingFunctionBase SF;
|
|
|
|
/// See header for a class description. It is declared here to avoid
|
|
/// to include <map> in the header file.
|
|
|
|
class EndgameFunctions {
|
|
public:
|
|
EndgameFunctions();
|
|
~EndgameFunctions();
|
|
template<class T> T* get(Key key) const;
|
|
|
|
private:
|
|
template<class T> void add(const string& keyCode);
|
|
|
|
static Key buildKey(const string& keyCode);
|
|
static const string swapColors(const string& keyCode);
|
|
|
|
// Here we store two maps, one for evaluate and one for scaling
|
|
pair<map<Key, EF*>, map<Key, SF*> > maps;
|
|
|
|
// Maps accessing functions for const and non-const references
|
|
template<typename T> const map<Key, T*>& get() const { return maps.first; }
|
|
template<typename T> map<Key, T*>& get() { return maps.first; }
|
|
};
|
|
|
|
// Explicit specializations of a member function shall be declared in
|
|
// the namespace of which the class template is a member.
|
|
template<> const map<Key, SF*>&
|
|
EndgameFunctions::get<SF>() const { return maps.second; }
|
|
|
|
template<> map<Key, SF*>&
|
|
EndgameFunctions::get<SF>() { return maps.second; }
|
|
|
|
|
|
////
|
|
//// Functions
|
|
////
|
|
|
|
|
|
/// Constructor for the MaterialInfoTable class
|
|
|
|
MaterialInfoTable::MaterialInfoTable(unsigned int numOfEntries) {
|
|
|
|
size = numOfEntries;
|
|
entries = new MaterialInfo[size];
|
|
funcs = new EndgameFunctions();
|
|
if (!entries || !funcs)
|
|
{
|
|
cerr << "Failed to allocate " << (numOfEntries * sizeof(MaterialInfo))
|
|
<< " bytes for material hash table." << endl;
|
|
Application::exit_with_failure();
|
|
}
|
|
}
|
|
|
|
|
|
/// Destructor for the MaterialInfoTable class
|
|
|
|
MaterialInfoTable::~MaterialInfoTable() {
|
|
|
|
delete funcs;
|
|
delete [] entries;
|
|
}
|
|
|
|
|
|
/// MaterialInfoTable::get_material_info() takes a position object as input,
|
|
/// computes or looks up a MaterialInfo object, and returns a pointer to it.
|
|
/// If the material configuration is not already present in the table, 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) {
|
|
|
|
Key key = pos.get_material_key();
|
|
int index = key & (size - 1);
|
|
MaterialInfo* mi = entries + index;
|
|
|
|
// If mi->key matches the position's material hash key, it means that we
|
|
// have analysed this material configuration before, and we can simply
|
|
// return the information we found the last time instead of recomputing it.
|
|
if (mi->key == key)
|
|
return mi;
|
|
|
|
// Clear the MaterialInfo object, and set its key
|
|
mi->clear();
|
|
mi->key = key;
|
|
|
|
// A special case before looking for a specialized evaluation function
|
|
// KNN vs K is a draw.
|
|
if (key == KNNKMaterialKey || key == KKNNMaterialKey)
|
|
{
|
|
mi->factor[WHITE] = mi->factor[BLACK] = 0;
|
|
return mi;
|
|
}
|
|
|
|
// Let's look if we have a specialized evaluation function for this
|
|
// particular material configuration. First we look for a fixed
|
|
// configuration one, then a generic one if previous search failed.
|
|
if ((mi->evaluationFunction = funcs->get<EF>(key)) != NULL)
|
|
return mi;
|
|
|
|
else if ( pos.non_pawn_material(BLACK) == Value(0)
|
|
&& pos.piece_count(BLACK, PAWN) == 0
|
|
&& pos.non_pawn_material(WHITE) >= RookValueMidgame)
|
|
{
|
|
mi->evaluationFunction = &EvaluateKXK;
|
|
return mi;
|
|
}
|
|
else if ( pos.non_pawn_material(WHITE) == Value(0)
|
|
&& pos.piece_count(WHITE, PAWN) == 0
|
|
&& pos.non_pawn_material(BLACK) >= RookValueMidgame)
|
|
{
|
|
mi->evaluationFunction = &EvaluateKKX;
|
|
return mi;
|
|
}
|
|
else if ( pos.pawns() == EmptyBoardBB
|
|
&& pos.rooks() == EmptyBoardBB
|
|
&& pos.queens() == EmptyBoardBB)
|
|
{
|
|
// Minor piece endgame with at least one minor piece per side,
|
|
// and no pawns.
|
|
assert(pos.knights(WHITE) | pos.bishops(WHITE));
|
|
assert(pos.knights(BLACK) | pos.bishops(BLACK));
|
|
|
|
if ( pos.piece_count(WHITE, BISHOP) + pos.piece_count(WHITE, KNIGHT) <= 2
|
|
&& pos.piece_count(BLACK, BISHOP) + pos.piece_count(BLACK, KNIGHT) <= 2)
|
|
{
|
|
mi->evaluationFunction = &EvaluateKmmKm;
|
|
return mi;
|
|
}
|
|
}
|
|
|
|
// OK, we didn't find any special evaluation function for the current
|
|
// material configuration. Is there a suitable scaling function?
|
|
//
|
|
// The code below is rather messy, and it could easily get worse later,
|
|
// if we decide to add more special cases. We face problems when there
|
|
// are several conflicting applicable scaling functions and we need to
|
|
// decide which one to use.
|
|
SF* sf;
|
|
|
|
if ((sf = funcs->get<SF>(key)) != NULL)
|
|
{
|
|
mi->scalingFunction[sf->color()] = sf;
|
|
return mi;
|
|
}
|
|
|
|
if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
|
|
&& pos.piece_count(WHITE, BISHOP) == 1
|
|
&& pos.piece_count(WHITE, PAWN) >= 1)
|
|
mi->scalingFunction[WHITE] = &ScaleKBPK;
|
|
|
|
if ( pos.non_pawn_material(BLACK) == BishopValueMidgame
|
|
&& pos.piece_count(BLACK, BISHOP) == 1
|
|
&& pos.piece_count(BLACK, PAWN) >= 1)
|
|
mi->scalingFunction[BLACK] = &ScaleKKBP;
|
|
|
|
if ( pos.piece_count(WHITE, PAWN) == 0
|
|
&& pos.non_pawn_material(WHITE) == QueenValueMidgame
|
|
&& pos.piece_count(WHITE, QUEEN) == 1
|
|
&& pos.piece_count(BLACK, ROOK) == 1
|
|
&& pos.piece_count(BLACK, PAWN) >= 1)
|
|
mi->scalingFunction[WHITE] = &ScaleKQKRP;
|
|
|
|
else if ( pos.piece_count(BLACK, PAWN) == 0
|
|
&& pos.non_pawn_material(BLACK) == QueenValueMidgame
|
|
&& pos.piece_count(BLACK, QUEEN) == 1
|
|
&& pos.piece_count(WHITE, ROOK) == 1
|
|
&& pos.piece_count(WHITE, PAWN) >= 1)
|
|
mi->scalingFunction[BLACK] = &ScaleKRPKQ;
|
|
|
|
if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0))
|
|
{
|
|
if (pos.piece_count(BLACK, PAWN) == 0)
|
|
{
|
|
assert(pos.piece_count(WHITE, PAWN) >= 2);
|
|
mi->scalingFunction[WHITE] = &ScaleKPsK;
|
|
}
|
|
else if (pos.piece_count(WHITE, PAWN) == 0)
|
|
{
|
|
assert(pos.piece_count(BLACK, PAWN) >= 2);
|
|
mi->scalingFunction[BLACK] = &ScaleKKPs;
|
|
}
|
|
else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1)
|
|
{
|
|
mi->scalingFunction[WHITE] = &ScaleKPKPw;
|
|
mi->scalingFunction[BLACK] = &ScaleKPKPb;
|
|
}
|
|
}
|
|
|
|
// 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, BISHOP);
|
|
|
|
mi->spaceWeight = minorPieceCount * minorPieceCount;
|
|
}
|
|
|
|
// Evaluate the material balance
|
|
|
|
const int bishopsPair_count[2] = { pos.piece_count(WHITE, BISHOP) > 1, pos.piece_count(BLACK, BISHOP) > 1 };
|
|
Color c, them;
|
|
int sign;
|
|
int matValue = 0;
|
|
|
|
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 (pos.piece_count(c, ROOK) >= 1)
|
|
matValue -= sign * ((pos.piece_count(c, ROOK) - 1) * RedundantRookPenalty + pos.piece_count(c, QUEEN) * RedundantQueenPenalty);
|
|
|
|
// Second-degree polynomial material imbalance by Tord Romstad
|
|
//
|
|
// We use NO_PIECE_TYPE as a place holder for the bishop pair "extended piece",
|
|
// this allow us to be more flexible in defining bishop pair bonuses.
|
|
them = opposite_color(c);
|
|
for (PieceType pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
|
|
{
|
|
int c1, c2, c3;
|
|
c1 = sign * (pt1 != NO_PIECE_TYPE ? pos.piece_count(c, pt1) : bishopsPair_count[c]);
|
|
if (!c1)
|
|
continue;
|
|
|
|
matValue += c1 * LinearCoefficients[pt1];
|
|
|
|
for (PieceType pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
|
|
{
|
|
c2 = (pt2 != NO_PIECE_TYPE ? pos.piece_count(c, pt2) : bishopsPair_count[c]);
|
|
c3 = (pt2 != NO_PIECE_TYPE ? pos.piece_count(them, pt2) : bishopsPair_count[them]);
|
|
matValue += c1 * c2 * QuadraticCoefficientsSameColor[pt1][pt2];
|
|
matValue += c1 * c3 * QuadraticCoefficientsOppositeColor[pt1][pt2];
|
|
}
|
|
}
|
|
}
|
|
|
|
mi->value = int16_t(matValue / 16);
|
|
return mi;
|
|
}
|
|
|
|
|
|
/// EndgameFunctions member definitions. This class is used to store the maps
|
|
/// of end game and scaling functions that MaterialInfoTable will query for
|
|
/// each key. The maps are constant and are populated only at construction,
|
|
/// but are per-thread instead of globals to avoid expensive locks needed
|
|
/// because std::map is not guaranteed to be thread-safe even if accessed
|
|
/// only for a lookup.
|
|
|
|
EndgameFunctions::EndgameFunctions() {
|
|
|
|
KNNKMaterialKey = buildKey("KNNK");
|
|
KKNNMaterialKey = buildKey("KKNN");
|
|
|
|
add<EvaluationFunction<KPK> >("KPK");
|
|
add<EvaluationFunction<KBNK> >("KBNK");
|
|
add<EvaluationFunction<KRKP> >("KRKP");
|
|
add<EvaluationFunction<KRKB> >("KRKB");
|
|
add<EvaluationFunction<KRKN> >("KRKN");
|
|
add<EvaluationFunction<KQKR> >("KQKR");
|
|
add<EvaluationFunction<KBBKN> >("KBBKN");
|
|
|
|
add<ScalingFunction<KNPK> >("KNPK");
|
|
add<ScalingFunction<KRPKR> >("KRPKR");
|
|
add<ScalingFunction<KBPKB> >("KBPKB");
|
|
add<ScalingFunction<KBPPKB> >("KBPPKB");
|
|
add<ScalingFunction<KBPKN> >("KBPKN");
|
|
add<ScalingFunction<KRPPKRP> >("KRPPKRP");
|
|
add<ScalingFunction<KRPPKRP> >("KRPPKRP");
|
|
}
|
|
|
|
EndgameFunctions::~EndgameFunctions() {
|
|
|
|
for (map<Key, EF*>::iterator it = maps.first.begin(); it != maps.first.end(); ++it)
|
|
delete (*it).second;
|
|
|
|
for (map<Key, SF*>::iterator it = maps.second.begin(); it != maps.second.end(); ++it)
|
|
delete (*it).second;
|
|
}
|
|
|
|
Key EndgameFunctions::buildKey(const string& keyCode) {
|
|
|
|
assert(keyCode.length() > 0 && keyCode[0] == 'K');
|
|
assert(keyCode.length() < 8);
|
|
|
|
stringstream s;
|
|
bool upcase = false;
|
|
|
|
// Build up a fen substring with the given pieces, note
|
|
// that the fen string could be of an illegal position.
|
|
for (size_t i = 0; i < keyCode.length(); i++)
|
|
{
|
|
if (keyCode[i] == 'K')
|
|
upcase = !upcase;
|
|
|
|
s << char(upcase? toupper(keyCode[i]) : tolower(keyCode[i]));
|
|
}
|
|
s << 8 - keyCode.length() << "/8/8/8/8/8/8/8 w -";
|
|
return Position(s.str()).get_material_key();
|
|
}
|
|
|
|
const string EndgameFunctions::swapColors(const string& keyCode) {
|
|
|
|
// Build corresponding key for the opposite color: "KBPKN" -> "KNKBP"
|
|
size_t idx = keyCode.find("K", 1);
|
|
return keyCode.substr(idx) + keyCode.substr(0, idx);
|
|
}
|
|
|
|
template<class T>
|
|
void EndgameFunctions::add(const string& keyCode) {
|
|
|
|
typedef typename T::Base F;
|
|
|
|
get<F>().insert(pair<Key, F*>(buildKey(keyCode), new T(WHITE)));
|
|
get<F>().insert(pair<Key, F*>(buildKey(swapColors(keyCode)), new T(BLACK)));
|
|
}
|
|
|
|
template<class T>
|
|
T* EndgameFunctions::get(Key key) const {
|
|
|
|
typename map<Key, T*>::const_iterator it(get<T>().find(key));
|
|
return (it != get<T>().end() ? it->second : NULL);
|
|
}
|