eval.cpp

#include "eval.h"
#include <position.h>
#include <cstring>
#include <vector>
using namespace chess;
using namespace engine::eval;
namespace engine::eval{
    constexpr Value PawnValue = 100, KnightValue = 325, BishopValue = 350, RookValue = 500, QueenValue = 900;

    Value mg_pawn_table[64] = {
          0,   0,   0,   0,   0,   0,  0,   0,
         98, 134,  61,  95,  68, 126, 34, -11,
         -6,   7,  26,  31,  65,  56, 25, -20,
        -14,  13,   6,  21,  23,  12, 17, -23,
        -27,  -2,  -5,  12,  17,   6, 10, -25,
        -26,  -4,  -4, -10,   3,   3, 33, -12,
        -35,  -1, -20, -23, -15,  24, 38, -22,
          0,   0,   0,   0,   0,   0,  0,   0,
    };

    Value eg_pawn_table[64] = {
          0,   0,   0,   0,   0,   0,   0,   0,
        178, 173, 158, 134, 147, 132, 165, 187,
         94, 100,  85,  67,  56,  53,  82,  84,
         32,  24,  13,   5,  -2,   4,  17,  17,
         13,   9,  -3,  -7,  -7,  -8,   3,  -1,
          4,   7,  -6,   1,   0,  -5,  -1,  -8,
         13,   8,   8,  10,  13,   0,   2,  -7,
          0,   0,   0,   0,   0,   0,   0,   0,
    };

    Value mg_knight_table[64] = {
        -167, -89, -34, -49,  61, -97, -15, -107,
         -73, -41,  72,  36,  23,  62,   7,  -17,
         -47,  60,  37,  65,  84, 129,  73,   44,
          -9,  17,  19,  53,  37,  69,  18,   22,
         -13,   4,  16,  13,  28,  19,  21,   -8,
         -23,  -9,  12,  10,  19,  17,  25,  -16,
         -29, -53, -12,  -3,  -1,  18, -14,  -19,
        -105, -21, -58, -33, -17, -28, -19,  -23,
    };

    Value eg_knight_table[64] = {
        -58, -38, -13, -28, -31, -27, -63, -99,
        -25,  -8, -25,  -2,  -9, -25, -24, -52,
        -24, -20,  10,   9,  -1,  -9, -19, -41,
        -17,   3,  22,  22,  22,  11,   8, -18,
        -18,  -6,  16,  25,  16,  17,   4, -18,
        -23,  -3,  -1,  15,  10,  -3, -20, -22,
        -42, -20, -10,  -5,  -2, -20, -23, -44,
        -29, -51, -23, -15, -22, -18, -50, -64,
    };

    Value mg_bishop_table[64] = {
        -29,   4, -82, -37, -25, -42,   7,  -8,
        -26,  16, -18, -13,  30,  59,  18, -47,
        -16,  37,  43,  40,  35,  50,  37,  -2,
         -4,   5,  19,  50,  37,  37,   7,  -2,
         -6,  13,  13,  26,  34,  12,  10,   4,
          0,  15,  15,  15,  14,  27,  18,  10,
          4,  15,  16,   0,   7,  21,  33,   1,
        -33,  -3, -14, -21, -13, -12, -39, -21,
    };

    Value eg_bishop_table[64] = {
        -14, -21, -11,  -8, -7,  -9, -17, -24,
         -8,  -4,   7, -12, -3, -13,  -4, -14,
          2,  -8,   0,  -1, -2,   6,   0,   4,
         -3,   9,  12,   9, 14,  10,   3,   2,
         -6,   3,  13,  19,  7,  10,  -3,  -9,
        -12,  -3,   8,  10, 13,   3,  -7, -15,
        -14, -18,  -7,  -1,  4,  -9, -15, -27,
        -23,  -9, -23,  -5, -9, -16,  -5, -17,
    };

    Value mg_rook_table[64] = {
         32,  42,  32,  51, 63,  9,  31,  43,
         27,  32,  58,  62, 80, 67,  26,  44,
         -5,  19,  26,  36, 17, 45,  61,  16,
        -24, -11,   7,  26, 24, 35,  -8, -20,
        -36, -26, -12,  -1,  9, -7,   6, -23,
        -45, -25, -16, -17,  3,  0,  -5, -33,
        -44, -16, -20,  -9, -1, 11,  -6, -71,
        -19, -13,   1,  17, 16,  7, -37, -26,
    };

    Value eg_rook_table[64] = {
        13, 10, 18, 15, 12,  12,   8,   5,
        11, 13, 13, 11, -3,   3,   8,   3,
         7,  7,  7,  5,  4,  -3,  -5,  -3,
         4,  3, 13,  1,  2,   1,  -1,   2,
         3,  5,  8,  4, -5,  -6,  -8, -11,
        -4,  0, -5, -1, -7, -12,  -8, -16,
        -6, -6,  0,  2, -9,  -9, -11,  -3,
        -9,  2,  3, -1, -5, -13,   4, -20,
    };

    Value mg_queen_table[64] = {
        -28,   0,  29,  12,  59,  44,  43,  45,
        -24, -39,  -5,   1, -16,  57,  28,  54,
        -13, -17,   7,   8,  29,  56,  47,  57,
        -27, -27, -16, -16,  -1,  17,  -2,   1,
         -9, -26,  -9, -10,  -2,  -4,   3,  -3,
        -14,   2, -11,  -2,  -5,   2,  14,   5,
        -35,  -8,  11,   2,   8,  15,  -3,   1,
         -1, -18,  -9,  10, -15, -25, -31, -50,
    };

    Value eg_queen_table[64] = {
         -9,  22,  22,  27,  27,  19,  10,  20,
        -17,  20,  32,  41,  58,  25,  30,   0,
        -20,   6,   9,  49,  47,  35,  19,   9,
          3,  22,  24,  45,  57,  40,  57,  36,
        -18,  28,  19,  47,  31,  34,  39,  23,
        -16, -27,  15,   6,   9,  17,  10,   5,
        -22, -23, -30, -16, -16, -23, -36, -32,
        -33, -28, -22, -43,  -5, -32, -20, -41,
    };

    Value mg_king_table[64] = {
        -65,  23,  16, -15, -56, -34,   2,  13,
         29,  -1, -20,  -7,  -8,  -4, -38, -29,
         -9,  24,   2, -16, -20,   6,  22, -22,
        -17, -20, -12, -27, -30, -25, -14, -36,
        -49,  -1, -27, -39, -46, -44, -33, -51,
        -14, -14, -22, -46, -44, -30, -15, -27,
          1,   7,  -8, -64, -43, -16,   9,   8,
        -15,  36,  12, -54,   8, -28,  24,  14,
    };

    Value eg_king_table[64] = {
        -74, -35, -18, -18, -11,  15,   4, -17,
        -12,  17,  14,  17,  17,  38,  23,  11,
         10,  17,  23,  15,  20,  45,  44,  13,
         -8,  22,  24,  27,  26,  33,  26,   3,
        -18,  -4,  21,  24,  27,  23,   9, -11,
        -19,  -3,  11,  21,  23,  16,   7,  -9,
        -27, -11,   4,  13,  14,   4,  -5, -17,
        -53, -34, -21, -11, -28, -14, -24, -43
    };

    Value *mg_pesto_table[] =
    {
        {0},
        mg_pawn_table,
        mg_knight_table,
        mg_bishop_table,
        mg_rook_table,
        mg_queen_table,
        mg_king_table
    };

    Value *eg_pesto_table[] =
    {
        {0},
        eg_pawn_table,
        eg_knight_table,
        eg_bishop_table,
        eg_rook_table,
        eg_queen_table,
        eg_king_table
    };

    Value eval(const chess::Board &board){
        int pieceCount[10] = {
            board.count<PAWN,WHITE>(),
            board.count<KNIGHT,WHITE>(),
            board.count<BISHOP,WHITE>(),
            board.count<ROOK,WHITE>(),
            board.count<QUEEN,WHITE>(),
            board.count<PAWN,BLACK>(),
            board.count<KNIGHT,BLACK>(),
            board.count<BISHOP,BLACK>(),
            board.count<ROOK,BLACK>(),
            board.count<QUEEN,BLACK>(),
        };
        Value material = (pieceCount[0] * PawnValue + pieceCount[1] * KnightValue + pieceCount[2] * BishopValue + pieceCount[3] * RookValue + pieceCount[4] * QueenValue)
                     - (pieceCount[5] * PawnValue + pieceCount[6] * KnightValue + pieceCount[7] * BishopValue + pieceCount[8] * RookValue + pieceCount[9] * QueenValue);
        constexpr int KnightPhase = 1;
        constexpr int BishopPhase = 1;
        constexpr int RookPhase = 2;
        constexpr int QueenPhase = 4;
        constexpr int TotalPhase = KnightPhase * 4 + BishopPhase * 4 + RookPhase * 4 + QueenPhase * 2;

        int phase = (pieceCount[1] + pieceCount[6]) * KnightPhase +
                    (pieceCount[2] + pieceCount[7]) * BishopPhase +
                    (pieceCount[3] + pieceCount[8]) * RookPhase +
                    (pieceCount[4] + pieceCount[9]) * QueenPhase;

        phase = (phase * 256 + TotalPhase / 2) / TotalPhase;
        const int sign = board.sideToMove() == chess::Color::WHITE ? 1 : -1;

        int mgScore = material;
        int egScore = material;
        {
            Bitboard occ = board.occ();
            while (occ) {
                Square i = (Square)pop_lsb(occ);
                auto p = board.at(i);
                int _sign=1;
                if (color_of(p)==BLACK){
                    _sign=-1;
                    i = square_mirror(i);
                }
                mgScore += _sign*mg_pesto_table[piece_of(p)][i];
                egScore += _sign*eg_pesto_table[piece_of(p)][i];
            }
        }
        Value finalScore = ((mgScore * phase) + (egScore * (256 - phase))) / 256 * sign;
        return finalScore;
    }
    Value piece_value(PieceType pt){
        Value pieces[]={0,PawnValue,KnightValue,BishopValue,RookValue,QueenValue};
        return pieces[pt];
    }
}