chessy/src/Evaluate.cpp

#include "Evaluate.h"

#include "ChessGame.h"

using namespace chessy;



namespace chessy
{
    namespace values
    {
        const MoveValue PAWN =      1.0f;
        const MoveValue KNIGHT =    3.0f;
        const MoveValue BISHOP =    3.0f;
        const MoveValue ROOK =      5.0f;
        const MoveValue QUEEN =     9.0f;
    }
}


#include <random>
static typename std::mt19937 e(1034345);
static std::uniform_real_distribution<MoveValue> ee(0, 0.001);

template<Side side>
MoveValue chessy::evaluatePositives(const ChessGame& game)
{
    MoveValue piecePoints = 0;
    const Board& bd = game.getBoard();
    Bitboard p = bd.getPawns<side>();
    Bitboard n = bd.getKnights<side>();
    Bitboard b = bd.getBishops<side>();
    Bitboard r = bd.getRooks<side>();
    Bitboard q = bd.getQueens<side>();
    Bitboard k = bd.getKing<side>();
    piecePoints += values::PAWN *   p.popcount();
    piecePoints += values::KNIGHT * n.popcount();
    piecePoints += values::BISHOP * b.popcount();
    piecePoints += values::ROOK *   r.popcount();
    piecePoints += values::QUEEN *  q.popcount();

    for (auto knight : PositionSet{ n })
        piecePoints += KnightMoveGenerator{ knight, bd.get<side>() }.getBitboard().popcount() * 0.05;
    for (auto bishop : PositionSet{ b })
        piecePoints += PrimitiveBishopMoveGenerator{ bishop, bd.get<otherSide(side)>(), bd.get<side>() }.getBitboard().popcount() * 0.03;
    for (auto rook : PositionSet{ r })
        piecePoints += PrimitiveRookMoveGenerator{ rook, bd.get<otherSide(side)>(), bd.get<side>() }.getBitboard().popcount() * 0.03;
    for (auto queen : PositionSet{ q })
        piecePoints += PrimitiveQueenMoveGenerator{ queen, bd.get<otherSide(side)>(), bd.get<side>() }.getBitboard().popcount() * 0.012;

    return piecePoints;// +ee(e);
    /*
    constexpr Side other = otherSide(side);
    p = bd.getPawns<other>();
    n = bd.getKnights<other>();
    b = bd.getBishops<other>();
    r = bd.getRooks<other>();
    q = bd.getQueens<other>();
    k = bd.getKing<other>();
    piecePoints -= 1 * p.popcount();
    piecePoints -= 3 * n.popcount();
    piecePoints -= 3 * b.popcount();
    piecePoints -= 5 * r.popcount();
    piecePoints -= 9 * q.popcount();

    //for (auto knight : PositionSet{ n })
    //    piecePoints -= KnightMoveGenerator{ knight, bd.get<otherSide(side)>() }.getBitboard().popcount() * 0.2;
    for (auto bishop : PositionSet{ b })
    piecePoints -= PrimitiveBishopMoveGenerator{ bishop, bd.get<side>(), bd.get<otherSide(side)>() }.getBitboard().popcount() * 0.2;
    */
}


MoveValue chessy::evaluate(const ChessGame& game)
{
    if (game.getTurn() == WHITE_SIDE)
        return evaluatePositives<WHITE_SIDE>(game) -
        evaluatePositives<BLACK_SIDE>(game);
    else
        return evaluatePositives<BLACK_SIDE>(game) -
        evaluatePositives<WHITE_SIDE>(game);
}