int Evaluation::evaluateMobility(int color, Position& position) {
assert(Color::isValid(color));
int knightMobility = 0;
for (auto squares = position.pieces[color][PieceType::KNIGHT].squares; squares != 0; squares = Bitboard::remainder(squares)) {
int square = Bitboard::next(squares);
knightMobility += evaluateMobility(color, position, square, Square::knightDirections);
}
int bishopMobility = 0;
for (auto squares = position.pieces[color][PieceType::BISHOP].squares; squares != 0; squares = Bitboard::remainder(squares)) {
int square = Bitboard::next(squares);
bishopMobility += evaluateMobility(color, position, square, Square::bishopDirections);
}
int rookMobility = 0;
for (auto squares = position.pieces[color][PieceType::ROOK].squares; squares != 0; squares = Bitboard::remainder(squares)) {
int square = Bitboard::next(squares);
rookMobility += evaluateMobility(color, position, square, Square::rookDirections);
}
int queenMobility = 0;
for (auto squares = position.pieces[color][PieceType::QUEEN].squares; squares != 0; squares = Bitboard::remainder(squares)) {
int square = Bitboard::next(squares);
queenMobility += evaluateMobility(color, position, square, Square::queenDirections);
}
return knightMobility * 4
+ bishopMobility * 5
+ rookMobility * 2
+ queenMobility;
}
/**
* Evaluates the position.
*
* @param position the position.
* @return the evaluation value in centipawns.
*/
int Evaluation::evaluate(Position& position) {
// Initialize
int myColor = position.activeColor;
int oppositeColor = Color::opposite(myColor);
int value = 0;
// Evaluate material
int materialScore = (evaluateMaterial(myColor, position) - evaluateMaterial(oppositeColor, position))
* materialWeight / MAX_WEIGHT;
value += materialScore;
// Evaluate mobility
int mobilityScore = (evaluateMobility(myColor, position) - evaluateMobility(oppositeColor, position))
* mobilityWeight / MAX_WEIGHT;
value += mobilityScore;
// Add Tempo
value += TEMPO;
assert(std::abs(value) < Value::CHECKMATE_THRESHOLD);
return value;
}
int Evaluation::evaluate(Position& position, bool heavy, int beta, bool dumpoutput) {
// Initialize
int myColor = position.activeColor;
int oppositeColor = Color::opposite(myColor);
int value = 0;
// Evaluate material
int mymaterial = evaluateMaterial(myColor, position);
int materialScore = (mymaterial - evaluateMaterial(oppositeColor, position))
* materialWeight / MAX_WEIGHT;
value += materialScore;
if (dumpoutput) {
std::cout << " materialscore: " << mymaterial * materialWeight / MAX_WEIGHT << " " << materialScore;
}
if (value >= beta + BETA_THRESHOLD) {
return value;
}
if (heavy) {
double materialRatio =(double) mymaterial / maxMaterial;
// Evaluate mobility
int mymobility = evaluateMobility(myColor, position);
int mobilityScore = (mymobility - evaluateMobility(oppositeColor, position))
* mobilityWeight / MAX_WEIGHT;
value += mobilityScore;
if (dumpoutput) {
std::cout << " mobilityscore: " << mymobility * mobilityWeight / MAX_WEIGHT << " " << mobilityScore;
}
// Evaluate center control
int mycentre = evaluateCenter(myColor, position);
int centerScore = (mycentre - evaluateCenter(oppositeColor, position))
* materialRatio * centerWeight / MAX_WEIGHT;
value += centerScore;
if (dumpoutput) {
std::cout << " centrescore: " << int (mycentre * materialRatio * centerWeight / MAX_WEIGHT) << " " << centerScore;
}
// Evaluate Pawn structure
int mypawn = evaluatePawn(myColor, position);
int pawnScore = (mypawn - evaluatePawn(oppositeColor, position))
* pawnStructureWeight / MAX_WEIGHT;
value += pawnScore;
if (dumpoutput) {
std::cout << " pawnscore: " << int(mypawn * pawnStructureWeight / MAX_WEIGHT) << " " << pawnScore;
}
// Evaluate King Safety
int myking = evaluateKingSafety(myColor, position);
int kingSafetyScore = (myking - evaluateKingSafety(oppositeColor, position))
* materialRatio * kingSafetyWeight / MAX_WEIGHT;
value += kingSafetyScore;
if (dumpoutput) {
std::cout << " kingscore: " << int(myking * materialRatio * kingSafetyWeight / MAX_WEIGHT) << " " << kingSafetyScore;
}
}
// Add Tempo
value += TEMPO;
assert(std::abs(value) < Value::CHECKMATE_THRESHOLD);
return value;
}
