update

BasicEngine.cpp

@@ -0,0 +1,22 @@
+#include <iostream>
+#include "BasicEngine.hpp"
+#include "Search.hpp"
+
+std::string BasicEngine::name() const {
+    return mName;
+}
+std::string BasicEngine::version() const {
+    return mVersion;
+}
+std::string BasicEngine::author() const {
+    return mAuthor;
+}
+void BasicEngine::newGame() {
+
+}
+PrincipalVariation BasicEngine::pv(const Board &board, const TimeInfo::Optional &timeInfo) {
+    (void)board;
+    (void)timeInfo;
+    auto pv =Search::start(board);
+    return pv;
+}

BasicEngine.hpp

@@ -0,0 +1,23 @@
+#ifndef CHESS_ENGINE_BASICENGINE_HPP
+#define CHESS_ENGINE_BASICENGINE_HPP
+
+#include "Engine.hpp"
+class BasicEngine final : public Engine {
+
+public:
+
+    std::string name() const override;
+    std::string version() const override;
+    std::string author() const override;
+    void newGame() override;
+    PrincipalVariation pv(const Board &board, const TimeInfo::Optional &timeInfo) override;
+
+private:
+
+    std::string mName = "Egon++";
+    std::string mVersion = "1.0~Egon+C";
+    std::string mAuthor = "Bols";
+
+};
+
+#endif //CHESS_ENGINE_BASICENGINE_HPP

BitBoard.cpp

@@ -25,13 +25,6 @@ std::ostream &operator<<(std::ostream &os, const BitBoard &board) {
     return os;
 }
 
-BitBoard BitBoard::getRank(int r) {
-    return (genShift(1ULL, (r + 1) * 8) - 1) & genShift(~1ULL, r * 8 - 1);
-}
-BitBoard BitBoard::genShift(BitBoard x, const int s) {
-    return (s < 0) ? (x >> -s) : (s > 63) ? x : (x << s);
-}
-
 BitBoard BitBoard::northFill() const {
     BitBoard result(mBoard);
     result |= (result << 8);
@@ -52,11 +45,88 @@ BitBoard BitBoard::fileFill() const {
     return northFill() | southFill();
 }
 
-BitBoard BitBoard::kingAttacks(const BitBoard bb) {
-    BitBoard result = bb.east() | bb.west() | bb;
+BitBoard BitBoard::kingMoves(const BitBoard kings) {
+    BitBoard result = kings.east() | kings.west() | kings;
     result |= (result.north() | result.south());
-    result ^= bb;
+    result ^= kings;
 
     return result;
-
+}
+
+BitBoard BitBoard::castlingMoves(BitBoard kings, BitBoard rooks, BitBoard empty) {
+    kings |= (kings.east() | kings.west()) & empty;
+    kings |= (kings.east() | kings.west()) & empty;
+    kings |= kings.west() & empty;
+    rooks |= (rooks.east() | rooks.west()) & empty;
+    rooks |= (rooks.east() | rooks.west()) & empty;
+    rooks |= (rooks.east()) & empty;
+
+    return kings & rooks & CastlingSquares;
+}
+
+BitBoard BitBoard::bishopAttacks(BitBoard bishops, BitBoard empty) {
+    BitBoard result = 0;
+    empty ^= bishops;
+
+    BitBoard diag1 = (bishops.northWest() | bishops.southEast() | bishops) & empty;
+    BitBoard diag2 = (bishops.northEast() | bishops.southWest() | bishops) & empty;
+
+    for (int i = 0; i < 6; i++) {
+        result |= (diag1 | diag2);
+        diag1 = (diag1.northWest() | diag1.southEast()) & empty;
+        diag2 = (diag2.northEast() | diag2.southWest()) & empty;
+    }
+
+    return (result | diag1.northWest() | diag1.southEast() | diag2.northEast() | diag2.southWest()) & ~bishops;
+}
+
+BitBoard BitBoard::rookAttacks(BitBoard rooks, BitBoard empty) {
+    BitBoard result = 0;
+    empty ^= rooks;
+
+    BitBoard dir1 = (rooks.north() | rooks.south() | rooks) & empty;
+    BitBoard dir2 = (rooks.east() | rooks.west() | rooks) & empty;
+
+    for (int i = 0; i < 6; i++) {
+        result |= (dir1 | dir2);
+        dir1 = (dir1.north() | dir1.south()) & empty;
+        dir2 = (dir2.east() | dir2.west()) & empty;
+    }
+
+    return (result | dir1.north() | dir1.south() | dir2.east() | dir2.west()) & ~rooks;
+}
+
+BitBoard BitBoard::queenAttacks(BitBoard queens, BitBoard empty) {
+    return rookAttacks(queens, empty) | bishopAttacks(queens, empty);
+}
+
+BitBoard BitBoard::knightMoves(BitBoard knights) {
+    BitBoard east, west, result;
+
+    east = knights.east();
+    west = knights.west();
+    result = (east | west) << 16;
+    result |= (east | west) >> 16;
+    east = east.east();
+    west = west.west();
+    result |= (east | west) << 8;
+    result |= (east | west) >> 8;
+
+    return result;
+}
+
+BitBoard BitBoard::pawnNorthAttacks(BitBoard pawns, BitBoard targets) {
+    return (pawns.northEast() | pawns.northWest()) & targets;
+}
+BitBoard BitBoard::pawnNorthMoves(BitBoard pawns, BitBoard empty) {
+    pawns = pawns.north() & empty;
+    return (pawns | (pawns.north() & Rank4)) & empty;
+}
+
+BitBoard BitBoard::pawnSouthAttacks(BitBoard pawns, BitBoard targets) {
+    return (pawns.southEast() | pawns.southWest()) & targets;
+}
+BitBoard BitBoard::pawnSouthMoves(BitBoard pawns, BitBoard empty) {
+    pawns = pawns.south() & empty;
+    return (pawns | (pawns.south() & Rank5)) & empty;
 }

BitBoard.hpp

@@ -14,6 +14,14 @@ enum DefinedBoards : uint64_t {
     FFile = AFile << 5,
     GFile = AFile << 6,
     HFile = AFile << 7,
+    Rank1 = 0x00000000000000FF,
+    Rank2 = Rank1 << 8,
+    Rank3 = Rank1 << 16,
+    Rank4 = Rank1 << 24,
+    Rank5 = Rank1 << 32,
+    Rank6 = Rank1 << 40,
+    Rank7 = Rank1 << 48,
+    Rank8 = Rank1 << 56,
     WhiteCastlingRank = (1ULL << A2) - 1,
     BlackCastlingRank = (~1ULL << H7),
     CastlingRanks = WhiteCastlingRank | BlackCastlingRank,
@@ -31,6 +39,9 @@ public:
     explicit constexpr operator bool() const {
         return mBoard != 0;
     }
+    explicit constexpr operator unsigned int() const {
+        return mBoard;
+    }
     explicit constexpr operator unsigned long() const {
         return mBoard;
     }
@@ -98,20 +109,29 @@ public:
     BitBoard southFill() const;
     BitBoard fileFill() const;
 
-    static BitBoard kingAttacks(BitBoard bb);
+    static BitBoard bishopAttacks(BitBoard pos, BitBoard empty);
+    static BitBoard rookAttacks(BitBoard rooks, BitBoard empty);
+    static BitBoard queenAttacks(BitBoard queens, BitBoard empty);
+    static BitBoard kingMoves(const BitBoard kings);
+    static BitBoard castlingMoves(BitBoard kings, BitBoard rooks, BitBoard empty);
+    static BitBoard knightMoves(BitBoard knights);
+
+    static BitBoard pawnNorthAttacks(BitBoard pawns, BitBoard targets);
+    static BitBoard pawnSouthAttacks(BitBoard pawns, BitBoard targets);
+
+    static BitBoard pawnNorthMoves(BitBoard pawns, BitBoard empty);
+    static BitBoard pawnSouthMoves(BitBoard pawns, BitBoard empty);
 
     static BitBoard fromIndex(unsigned i);
 
-    static BitBoard getRank(int r);
-
     // Returns the number of trailing 0-bits in b.
     // WARN: Check for 0!
-    int lsb() const;
+    unsigned lsb() const;
+    unsigned pop();
+    constexpr int count() const;
 
 private:
-    U64 mBoard = {};
-
-    static BitBoard genShift(BitBoard x, int s);
+    U64 mBoard = 0;
 };
 
 // Relational operators
@@ -255,8 +275,20 @@ inline BitBoard BitBoard::southEast() const {
 inline BitBoard BitBoard::southWest() const {
     return (mBoard >> 9) & ~HFile;
 }
-inline int BitBoard::lsb() const {
+
+inline unsigned BitBoard::lsb() const {
     return __builtin_ctzll(mBoard);
 }
+inline unsigned BitBoard::pop() {
+    unsigned i = lsb();
+    mBoard &= mBoard - 1;
+
+    return i;
+}
+
+constexpr int BitBoard::count() const {
+    return __builtin_popcountll(mBoard);
+}
+
 
 #endif //CHESS_ENGINE_BITBOARD_HPP

Board.cpp

@@ -1,22 +1,19 @@
 #include "Board.hpp"
+#include "BoardState.hpp"
 
 #include <ostream>
 #include <cassert>
 #include <cmath>
 #include <bitset>
 #include <algorithm>
-#include <iostream>
-
-Board::Board() {
-}
 
 void Board::setPiece(const Square &square, const Piece::Optional &piece) {
     if (!piece.has_value())
         return;
 
     auto index = square.index();
-    for (auto &bb : mPieceBBs) {
-        bb.clear(index);
+    for (int i = 0; i < BB_NUM; i++) {
+        mPieceBBs[i].clear(index);
     }
 
     mPieceBBs[toIndex(piece->type())].set(index);
@@ -35,6 +32,42 @@ Piece::Optional Board::piece(const Square &square) const {
     return Piece(c, t);
 }
 
+int Board::evaluate() const {
+    int score = evaluate(mTurn);
+    score -= evaluate(!mTurn);
+
+    return score;
+}
+
+int Board::evaluate(const PieceColor color) const {
+    int score = 0;
+
+    BitBoard bb;
+    BitBoard colorMask = mPieceBBs[toIndex(color)];
+    for (int i = 0; i < 6; i++) {
+        bb = mPieceBBs[i+2] & colorMask;
+        score += Piece::PieceValue[i] * bb.count();
+    }
+
+//    BoardState bs = BoardState(&mPieceBBs, mOccupiedBB, mTurn, mCR, mEPS);
+//    score += round(mMobilityWeight * MoveGenerator::Mobility(bs, color));
+
+    return score;
+}
+
+bool Board::isCheckMate() const {
+    auto moves = MoveVec();
+    pseudoLegalMoves(moves);
+
+    if (!moves.empty())
+        return false;
+
+    BoardState bs = BoardState(&mPieceBBs, mOccupiedBB, mTurn, mCR, mEPS);
+    auto attacked = MoveGenerator::generateAttackedSquares(bs, ~mOccupiedBB, !mTurn);
+
+    return attacked & mPieceBBs[toIndex(PieceType::King)] & mPieceBBs[toIndex(mTurn)];
+}
+
 void Board::setTurn(PieceColor turn) {
     mTurn = turn;
 }
@@ -146,12 +179,37 @@ void Board::handlePawnDoubleAdvance(const Move &move, BitBoard bb, const Piece &
 }
 
 void Board::pseudoLegalMoves(MoveVec &moves) const {
-    (void) moves;
+    auto pieces = mPieceBBs[toIndex(mTurn)];
+
+    while (pieces) {
+        auto sq = Square(pieces.pop());
+        pseudoLegalMovesFrom(sq, moves);
+    }
 }
 
 void Board::pseudoLegalMovesFrom(const Square &from, Board::MoveVec &moves) const {
-    (void) from;
-    (void) moves;
+    auto fromBB = BitBoard::fromIndex(from.index());
+
+    if (!(fromBB & mPieceBBs[toIndex(mTurn)])) {
+        return;
+    }
+
+    BoardState bs = BoardState(&mPieceBBs, mOccupiedBB, mTurn, mCR, mEPS);
+
+    switch (pieceType(fromBB)) {
+    case PieceType::Pawn: MoveGenerator::generatePawnMoves(bs, from, moves);
+        break;
+    case PieceType::Knight: MoveGenerator::generateKnightMoves(bs, from, moves);
+        break;
+    case PieceType::Bishop: MoveGenerator::generateBishopMoves(bs, from, moves);
+        break;
+    case PieceType::Rook: MoveGenerator::generateRookMoves(bs, from, moves);
+        break;
+    case PieceType::Queen: MoveGenerator::generateQueenMoves(bs, from, moves);
+        break;
+    case PieceType::King: MoveGenerator::generateKingMoves(bs, from, moves);
+        break;
+    }
 }
 void Board::handleCastlingRights(const Piece &piece, const BitBoard &bb) {
     if (piece.type() != PieceType::King && piece.type() != PieceType::Rook) {

Board.hpp

@@ -6,6 +6,7 @@
 #include "Move.hpp"
 #include "CastlingRights.hpp"
 #include "BitBoard.hpp"
+#include "MoveGenerator.hpp"
 
 #include <optional>
 #include <iosfwd>
@@ -19,10 +20,12 @@ public:
     using Optional = std::optional<Board>;
     using MoveVec = std::vector<Move>;
 
-    Board();
+    Board() = default;
 
     void setPiece(const Square &square, const Piece::Optional &piece);
     Piece::Optional piece(const Square &square) const;
+    std::vector<Piece> pieces(PieceColor color) const;
+    int evaluate() const;
     void setTurn(PieceColor turn);
     PieceColor turn() const;
     void setCastlingRights(CastlingRights cr);
@@ -35,26 +38,32 @@ public:
     void pseudoLegalMoves(MoveVec &moves) const;
     void pseudoLegalMovesFrom(const Square &from, MoveVec &moves) const;
 
+    static constexpr int toIndex(PieceType t) {
+        return static_cast<int>(t);
+    }
+    static constexpr int toIndex(PieceColor c) {
+        return static_cast<int>(c);
+    }
+
+
+    bool isCheckMate() const;
+
 private:
 
     BitBoard mPieceBBs[BB_NUM] = {};
-    BitBoard mOccupiedBB = 0;
+    BitBoard mOccupiedBB = BitBoard(0);
 
-    PieceColor mTurn = PieceColor::White;
+    PieceColor mTurn = PieceColor(PieceColor::White);
     CastlingRights mCR = CastlingRights::None;
     std::optional<Square> mEPS;
 
+    constexpr static const double mMobilityWeight = 0.1;
+
     void handleCastlingRights(const Piece &piece, const BitBoard &bb);
+
     // Check if the move is castling without checking the rights or validity.
     static bool isMoveCastling(const BitBoard &from, const BitBoard &to, const Piece &piece);
 
-    static inline int toIndex(PieceType t) {
-        return static_cast<int>(t);
-    }
-    static inline int toIndex(PieceColor c) {
-        return static_cast<int>(c);
-    }
-
     inline PieceColor pieceColor(const BitBoard &mask) const {
         auto color = PieceColor::White;
         if (!(mPieceBBs[static_cast<unsigned>(color)] & mask)) {
@@ -77,8 +86,8 @@ private:
 
     void handlePawnDoubleAdvance(const Move &move, BitBoard bb, const Piece &movedPiece);
     void handleEnPassant(const Move &move, const Piece &movedPiece);
+    int evaluate(const PieceColor color) const;
 };
 
 std::ostream &operator<<(std::ostream &os, const Board &board);
-
 #endif

BoardState.hpp

@@ -0,0 +1,42 @@
+#ifndef CHESS_ENGINE_BOARDSTATE_HPP
+#define CHESS_ENGINE_BOARDSTATE_HPP
+
+#include "Piece.hpp"
+#include "BitBoard.hpp"
+#include "Board.hpp"
+
+#define BB_NUM 8
+
+struct BoardState {
+    BoardState(const BitBoard (*const pieceBBs)[8],
+               const BitBoard occupiedBB,
+               const PieceColor turn,
+               const CastlingRights cr,
+               const std::optional<Square> eps)
+            : pieceBBs(pieceBBs),
+              occupiedBB(occupiedBB),
+              turn(turn),
+              cr(cr),
+              eps(eps) {
+
+    }
+
+    const BitBoard (*const pieceBBs)[8];
+    const BitBoard occupiedBB;
+    const PieceColor turn;
+    const CastlingRights cr;
+    const std::optional<Square> eps;
+
+    inline PieceType pieceType(const BitBoard &mask) const {
+        for (int i = 2; i < BB_NUM; i++) {
+            if ((*pieceBBs)[i] & mask) {
+                return static_cast<PieceType>(i);
+            }
+        }
+
+        // Should not happen
+        return static_cast<PieceType>(0);
+    }
+};
+
+#endif //CHESS_ENGINE_BOARDSTATE_HPP

CMakeLists.txt

@@ -24,6 +24,10 @@ else ()
     add_compile_options(-Wall -Wextra -pedantic -Werror)
 endif ()
 
+if (CMAKE_BUILD_TYPE STREQUAL "Release")
+    add_compile_options(-O3 -march=native -funroll-loops)
+endif()
+
 add_library(cplchess_lib OBJECT
     Square.cpp
     Move.cpp
@@ -36,6 +40,9 @@ add_library(cplchess_lib OBJECT
     EngineFactory.cpp
     Uci.cpp
     BitBoard.cpp
+    MoveGenerator.cpp
+    Search.cpp
+    BasicEngine.cpp
 )
 
 target_include_directories(cplchess_lib PUBLIC .)

CastlingRights.hpp

@@ -11,6 +11,8 @@ enum class CastlingRights {
     BlackQueenside = 1 << 3,
     White = WhiteKingside | WhiteQueenside,
     Black = BlackKingside | BlackQueenside,
+    KingSide = BlackKingside | WhiteKingside,
+    QueenSide = BlackQueenside | WhiteQueenside,
     All = White | Black
 };
 

EngineFactory.cpp

@@ -1,5 +1,8 @@
 #include "EngineFactory.hpp"
 
+#include <memory>
+#include "BasicEngine.hpp"
+
 std::unique_ptr<Engine> EngineFactory::createEngine() {
-    return nullptr;
+    return std::make_unique<BasicEngine>();
 }

Move.cpp

@@ -3,10 +3,21 @@
 #include <ostream>
 #include <iostream>
 
-Move::Move(const Square &from, const Square &to, const std::optional<PieceType> &promotion)
-        : mFrom(from), mTo(to), mPromotion(promotion) {
+
+Move::Move(const Square &from, const Square &to) : mFrom(from), mTo(to) {
+
 }
 
+Move::Move(const Square &from, const Square &to, const std::optional<PieceType> &promotion, unsigned score)
+        : mFrom(from), mTo(to), mPromotion(promotion) {
+    mScore -= score;
+}
+
+Move::Move(const Square &from, const Square &to, unsigned int score) : mFrom(from), mTo(to) {
+    mScore -= score;
+}
+
+
 Move::Optional Move::fromUci(const std::string &uci) {
     if (uci.length() < 4 || uci.length() > 5)
         return std::nullopt;
@@ -48,17 +59,31 @@ std::ostream &operator<<(std::ostream &os, const Move &move) {
 }
 
 bool operator<(const Move &lhs, const Move &rhs) {
-    if (!(lhs.from() == rhs.from()))
-        return lhs.from() < rhs.from();
+    if (lhs.mScore != rhs.mScore) {
+        return lhs.mScore < rhs.mScore;
+    }
 
-    if (!(lhs.to() == rhs.to()))
-        return lhs.to() < rhs.to();
+    if (lhs.mFrom.index() != rhs.mFrom.index()) {
+        return lhs.mFrom.index() < rhs.mFrom.index();
+    }
+    if (lhs.mTo.index() != rhs.mTo.index()) {
+        return lhs.mTo.index() < rhs.mTo.index();
+    }
 
     return lhs.promotion() < rhs.promotion();
 }
 
 bool operator==(const Move &lhs, const Move &rhs) {
-    return lhs.from() == rhs.from()
+    return lhs.score() == rhs.score()
+           && lhs.from() == rhs.from()
            && lhs.to() == rhs.to()
            && lhs.promotion() == rhs.promotion();
 }
+
+unsigned int Move::score() const {
+    return mScore;
+}
+
+void Move::setScore(unsigned int score) {
+    mScore = score;
+}

Move.hpp

@@ -7,14 +7,17 @@
 #include <iosfwd>
 #include <optional>
 #include <string>
+#include <limits>
 
 class Move {
 public:
 
     using Optional = std::optional<Move>;
 
-    Move(const Square &from, const Square &to,
-         const std::optional<PieceType> &promotion = std::nullopt);
+    explicit Move(const Square &from, const Square &to);
+    explicit Move(const Square &from, const Square &to,
+         const std::optional<PieceType> &promotion, unsigned score = 0);
+    explicit Move(const Square &from, const Square &to, unsigned score);
 
     static Optional fromUci(const std::string &uci);
 
@@ -22,16 +25,23 @@ public:
     Square to() const;
     std::optional<PieceType> promotion() const;
 
+
+    friend bool operator<(const Move &lhs, const Move &rhs);
+    friend bool operator==(const Move &lhs, const Move &rhs);
+
 private:
-    const Square mFrom;
-    const Square mTo;
-    const std::optional<PieceType> mPromotion;
+    Square mFrom;
+    Square mTo;
+    std::optional<PieceType> mPromotion = std::nullopt;
+    unsigned mScore = std::numeric_limits<unsigned>::max();
+public:
+    unsigned int score() const;
+
+    void setScore(unsigned int mScore);
 };
 
 std::ostream &operator<<(std::ostream &os, const Move &move);
 
 // Needed for std::map, std::set
-bool operator<(const Move &lhs, const Move &rhs);
-bool operator==(const Move &lhs, const Move &rhs);
 
 #endif

MoveGenerator.cpp

@@ -0,0 +1,233 @@
+#include <iostream>
+#include "MoveGenerator.hpp"
+#include "Board.hpp"
+#include "BoardState.hpp"
+
+void MoveGenerator::generatePawnMoves(const BoardState &bs, const Square &from, MoveVec &moves) {
+
+    BitBoard targets = 0;
+    if (bs.eps.has_value()) {
+        targets |= BitBoard::fromIndex(bs.eps.value().index());
+    }
+
+    generatePawnMoves(bs, from, targets, moves);
+}
+
+void MoveGenerator::generatePawnMoves(const BoardState &bs, const Square &from, BitBoard targets, MoveVec &moves) {
+
+    auto fromBB = BitBoard::fromIndex(from.index());
+    targets |= (*bs.pieceBBs)[Board::toIndex(!bs.turn)];
+
+    BitBoard movesBB;
+    if (bs.turn == PieceColor::White) {
+        movesBB = BitBoard::pawnNorthAttacks(fromBB, targets) & ~(*bs.pieceBBs)[Board::toIndex(bs.turn)];
+        movesBB |= BitBoard::pawnNorthMoves(fromBB, ~bs.occupiedBB);
+    } else {
+        movesBB = BitBoard::pawnSouthAttacks(fromBB, targets) & ~(*bs.pieceBBs)[Board::toIndex(bs.turn)];
+        movesBB |= BitBoard::pawnSouthMoves(fromBB, ~bs.occupiedBB);
+    }
+
+    bool isPromotion = movesBB & (Rank1 | Rank8);
+    if (isPromotion) {
+        generateMovesWithPromotion(bs, from, movesBB, moves);
+    } else {
+        generateMoves(bs, from, movesBB, PieceType::Pawn, moves);
+    }
+}
+
+void MoveGenerator::generateBishopMoves(const BoardState &bs, const Square &from, MoveVec &moves) {
+    auto fromBB = BitBoard::fromIndex(from.index());
+    auto movesBB = BitBoard::bishopAttacks(fromBB, ~bs.occupiedBB) & ~(*bs.pieceBBs)[Board::toIndex(bs.turn)];
+
+    generateMoves(bs, from, movesBB, PieceType::Bishop, moves);
+}
+
+void
+MoveGenerator::generateMoves(const BoardState &bs, const Square &from, BitBoard movesBB, PieceType pt, MoveVec &moves) {
+    auto fromBB = BitBoard::fromIndex(from.index());
+    while (movesBB) {
+        auto to = Square(movesBB.pop());
+        auto toBB = BitBoard::fromIndex(to.index());
+        if (isCheck(bs, fromBB, toBB)) {
+            continue;
+        }
+
+
+        moves.emplace_back(from, to, score(bs, toBB, pt));
+    }
+}
+
+void
+MoveGenerator::generateMovesWithPromotion(const BoardState &bs, const Square &from, BitBoard movesBB, MoveVec &moves) {
+    auto fromBB = BitBoard::fromIndex(from.index());
+    while (movesBB) {
+        auto to = Square(movesBB.pop());
+        auto toBB = BitBoard::fromIndex(to.index());
+        if (isCheck(bs, fromBB, toBB)) {
+            continue;
+        }
+
+        for (const auto &kItem: Piece::PromotionTypes) {
+
+            unsigned s = Piece::PromotionScore[Board::toIndex(kItem) - 2] + score(bs, toBB, PieceType::Pawn);
+            moves.emplace_back(from, to, static_cast<PieceType>(kItem), s);
+        }
+    }
+}
+
+void MoveGenerator::generateKingMoves(const BoardState &bs, const Square &from, MoveGenerator::MoveVec &moves) {
+    auto fromBB = BitBoard::fromIndex(from.index());
+    auto movesBB = BitBoard::kingMoves(fromBB) & ~(*bs.pieceBBs)[Board::toIndex(bs.turn)];
+
+    if ((bs.cr & CastlingRights::All) != CastlingRights::None) {
+
+        auto checkCR = CastlingRights::White;
+        auto castlingRank = WhiteCastlingRank;
+        if (bs.turn == PieceColor::Black) {
+            checkCR = CastlingRights::Black;
+            castlingRank = BlackCastlingRank;
+        }
+
+        checkCR &= bs.cr;
+
+        if (checkCR != CastlingRights::None) {
+            // Generate attacked squares
+            BitBoard target = CastlingRanks | bs.occupiedBB;
+            auto attacked = generateAttackedSquares(bs, ~target, !bs.turn);
+
+            movesBB |= BitBoard::castlingMoves(fromBB & ~attacked,
+                                               (*bs.pieceBBs)[Board::toIndex(PieceType::Rook)],
+                                               ~bs.occupiedBB) & castlingRank;
+
+            if ((checkCR & CastlingRights::KingSide) == CastlingRights::None) {
+                movesBB &= ~GFile;
+            }
+            if ((checkCR & CastlingRights::QueenSide) == CastlingRights::None) {
+                movesBB &= ~CFile;
+            }
+        }
+    }
+
+    generateMoves(bs, from, movesBB, PieceType::King, moves);
+}
+
+void MoveGenerator::generateRookMoves(const BoardState &bs, const Square &from, MoveVec &moves) {
+    auto fromBB = BitBoard::fromIndex(from.index());
+    auto movesBB = BitBoard::rookAttacks(fromBB, ~bs.occupiedBB) & ~(*bs.pieceBBs)[Board::toIndex(bs.turn)];
+
+    generateMoves(bs, from, movesBB, PieceType::Rook, moves);
+}
+
+void MoveGenerator::generateQueenMoves(const BoardState &bs, const Square &from, MoveVec &moves) {
+    auto fromBB = BitBoard::fromIndex(from.index());
+    auto movesBB = BitBoard::queenAttacks(fromBB, ~bs.occupiedBB) & ~(*bs.pieceBBs)[Board::toIndex(bs.turn)];
+
+    generateMoves(bs, from, movesBB, PieceType::Queen, moves);
+}
+
+void MoveGenerator::generateKnightMoves(const BoardState &bs, const Square &from, MoveVec &moves) {
+
+    auto fromBB = BitBoard::fromIndex(from.index());
+    auto movesBB = BitBoard::knightMoves(fromBB) & ~(*bs.pieceBBs)[Board::toIndex(bs.turn)];
+    generateMoves(bs, from, movesBB, PieceType::Knight, moves);
+}
+
+BitBoard MoveGenerator::generateAttackedSquares(const BoardState &bs, BitBoard target, PieceColor opColor) {
+    auto opponentBB = (*bs.pieceBBs)[Board::toIndex(opColor)];
+    BitBoard attacked = 0;
+
+    // pawns
+    if (opColor == PieceColor::White) {
+        attacked |= BitBoard::pawnNorthAttacks((*bs.pieceBBs)[Board::toIndex(PieceType::Pawn)] & opponentBB, target);
+    } else {
+        attacked |= BitBoard::pawnSouthAttacks((*bs.pieceBBs)[Board::toIndex(PieceType::Pawn)] & opponentBB, target);
+    }
+
+    // knights
+    attacked |= BitBoard::knightMoves((*bs.pieceBBs)[Board::toIndex(PieceType::Knight)] & opponentBB) & ~target;
+
+    // Bishop
+    attacked |= BitBoard::bishopAttacks((*bs.pieceBBs)[Board::toIndex(PieceType::Bishop)] & opponentBB, target);
+
+    // Rook
+    attacked |= BitBoard::rookAttacks((*bs.pieceBBs)[Board::toIndex(PieceType::Rook)] & opponentBB, target);
+
+    // Queen
+    attacked |= BitBoard::queenAttacks((*bs.pieceBBs)[Board::toIndex(PieceType::Queen)] & opponentBB, target);
+
+    // King
+    attacked |= BitBoard::kingMoves((*bs.pieceBBs)[Board::toIndex(PieceType::Queen)] & opponentBB) & ~target;
+
+    return attacked;
+}
+
+inline bool MoveGenerator::isCheck(const BoardState &bs, const BitBoard &fromBB, const BitBoard &toBB) {
+    auto kingBB = (*bs.pieceBBs)[Board::toIndex(bs.turn)] & (*bs.pieceBBs)[Board::toIndex(PieceType::King)];
+    auto changeBB = (fromBB ^ toBB);
+    auto target = bs.occupiedBB ^ changeBB;
+
+    if (kingBB & fromBB) {
+
+        if (toBB & bs.occupiedBB) {
+            target ^= toBB;
+        }
+        if ((toBB & ~bs.occupiedBB)) {
+            kingBB ^= changeBB;
+        }
+    }
+
+
+    auto attacked = generateAttackedSquares(bs, ~target, !bs.turn);
+
+    return attacked & kingBB;
+}
+
+inline unsigned MoveGenerator::score(const BoardState &bs, const BitBoard &toBB, const PieceType moved) {
+
+    unsigned score = 0;
+    auto opponentBB = bs.occupiedBB & ~(*bs.pieceBBs)[Board::toIndex(bs.turn)];
+
+
+    // Check Capture
+    auto captureBB = toBB & opponentBB;
+    if (captureBB) {
+        auto captured = bs.pieceType(captureBB);
+        score = Piece::MVV_LVA[Board::toIndex(captured)][Board::toIndex(moved)];
+    }
+
+    return score;
+}
+
+unsigned MoveGenerator::Mobility(const BoardState &bs, PieceColor color) {
+    unsigned count = 0;
+    auto colorMask = (*bs.pieceBBs)[Board::toIndex(color)];
+    auto targets = (*bs.pieceBBs)[Board::toIndex(!color)];
+
+    // Pawns
+    auto pawnsBB = (*bs.pieceBBs)[Board::toIndex(PieceType::Pawn)] & colorMask;
+    if (color == PieceColor::White) {
+        auto movesBB = BitBoard::pawnNorthAttacks(pawnsBB, targets) & ~colorMask;
+        movesBB |= BitBoard::pawnNorthMoves(pawnsBB, ~bs.occupiedBB);
+        count += movesBB.count();
+    } else {
+        auto movesBB = BitBoard::pawnSouthAttacks(pawnsBB, targets) & ~colorMask;
+        movesBB |= BitBoard::pawnSouthMoves(pawnsBB, ~bs.occupiedBB);
+        count += movesBB.count();
+    }
+    // Bishops
+    count += (BitBoard::bishopAttacks((*bs.pieceBBs)[Board::toIndex(PieceType::Bishop)] & colorMask, ~bs.occupiedBB) &
+              ~colorMask).count();
+    // Knights
+    count += (BitBoard::knightMoves((*bs.pieceBBs)[Board::toIndex(PieceType::Knight)] & colorMask) &
+              ~colorMask).count();
+    // Rook
+    count += (BitBoard::rookAttacks((*bs.pieceBBs)[Board::toIndex(PieceType::Rook)] & colorMask, ~bs.occupiedBB) &
+              ~colorMask).count();
+    // Queen
+    count += (BitBoard::queenAttacks((*bs.pieceBBs)[Board::toIndex(PieceType::Queen)] & colorMask, ~bs.occupiedBB) &
+              ~colorMask).count();
+    // King
+    count += (BitBoard::kingMoves((*bs.pieceBBs)[Board::toIndex(PieceType::King)] & colorMask) & ~colorMask).count();
+
+    return count;
+}

MoveGenerator.hpp

@@ -0,0 +1,40 @@
+#ifndef CHESS_ENGINE_MOVEGENERATOR_HPP
+#define CHESS_ENGINE_MOVEGENERATOR_HPP
+
+#include "Piece.hpp"
+#include "Square.hpp"
+#include "Move.hpp"
+#include "CastlingRights.hpp"
+#include "BitBoard.hpp"
+#include "BoardState.hpp"
+
+#include <optional>
+#include <iosfwd>
+#include <vector>
+#include <memory>
+
+class MoveGenerator {
+public:
+    using MoveVec = std::vector<Move>;
+
+    static void generatePawnMoves(const BoardState &bs, const Square &from, MoveVec &moves);
+    static void generateBishopMoves(const BoardState &bs, const Square &from, MoveVec &moves);
+    static void generateKingMoves(const BoardState &bs, const Square &from, MoveVec &moves);
+    static void generateRookMoves(const BoardState &bs, const Square &from, MoveVec &moves);
+    static void generateQueenMoves(const BoardState &bs, const Square &from, MoveVec &moves);
+    static void generateKnightMoves(const BoardState &bs, const Square &from, MoveVec &moves);
+    static BitBoard generateAttackedSquares(const BoardState &bs, BitBoard target, PieceColor opColor);
+
+    static unsigned int Mobility(const BoardState &bs, PieceColor color);
+
+private:
+    static void generatePawnMoves(const BoardState &bs, const Square &from, BitBoard targets, MoveVec &moves);
+
+    static void generateMoves(const BoardState &bs, const Square &from, BitBoard movesBB, PieceType pt, MoveVec &moves);
+    static void generateMovesWithPromotion(const BoardState &bs, const Square &from, BitBoard movesBB, MoveVec &moves);
+
+    inline static bool isCheck(const BoardState &bs, const BitBoard &fromBB, const BitBoard &toBB);
+    inline static unsigned score(const BoardState &bs, const BitBoard &toBB, PieceType moved);
+};
+
+#endif //CHESS_ENGINE_MOVEGENERATOR_HPP

Piece.hpp

@@ -24,17 +24,34 @@ class Piece {
 
 public:
 
+    constexpr static const PieceType PromotionTypes[4] = {PieceType::Knight, PieceType::Bishop, PieceType::Rook,
+                                                          PieceType::Queen};
+    constexpr static const unsigned PieceValue[6] = {100, 350, 350, 525, 1000, 10000};
+    constexpr static const unsigned PromotionScore[6] = {0, 26, 36, 46, 56, 0};
+
+    constexpr static const unsigned MVV_LVA[6][6] = {
+            {15, 14, 13, 12, 11, 10}, // Pawn
+            {25, 24, 23, 22, 21, 20}, // Knight
+            {35, 34, 33, 32, 31, 30}, // Bishop
+            {45, 44, 43, 42, 41, 40}, // Rook
+            {55, 54, 53, 52, 51, 50}, // Queen
+            {65, 64, 63, 62, 61, 60}, // King
+    };
+
     using Optional = std::optional<Piece>;
 
     Piece(PieceColor color, PieceType type);
 
     static Optional fromSymbol(char symbol);
+
     static char toSymbol(PieceType type);
 
     static std::optional<PieceType> pieceTypeFromSymbol(char symbol);
 
     PieceColor color() const;
+
     PieceType type() const;
+
     char toSymbol() const;
 
 private:
@@ -43,6 +60,7 @@ private:
 };
 
 bool operator==(const Piece &lhs, const Piece &rhs);
+
 std::ostream &operator<<(std::ostream &os, const Piece &piece);
 
 // Invert a color (White becomes Black and vice versa)

PrincipalVariation.cpp

@@ -1,29 +1,53 @@
 #include "PrincipalVariation.hpp"
 
 #include <ostream>
+#include <vector>
+
+
+PrincipalVariation::PrincipalVariation(const std::vector<Move> &v, bool isMate): mMoves(v), mIsMate(isMate) {
+
+}
+
+PrincipalVariation::PrincipalVariation(const std::vector<Move> &v, Board &board): mMoves(v) {
+    for (const auto &kMove : v) {
+        board.makeMove(kMove);
+    }
+
+    mIsMate = board.isCheckMate();
+    if (mIsMate || v.empty()) {
+        mScore = static_cast<int>(v.size());
+    } else {
+        mScore = board.evaluate();
+    }
+}
 
 
 bool PrincipalVariation::isMate() const {
-    return false;
+    return mIsMate;
 }
 
 int PrincipalVariation::score() const {
-    return 0;
+    return mScore;
 }
 
 std::size_t PrincipalVariation::length() const {
-    return 0;
+    return mMoves.size();
 }
 
 PrincipalVariation::MoveIter PrincipalVariation::begin() const {
-    return nullptr;
+    return mMoves.begin();
 }
 
 PrincipalVariation::MoveIter PrincipalVariation::end() const {
-    return nullptr;
+    return mMoves.end();
 }
-
 std::ostream &operator<<(std::ostream &os, const PrincipalVariation &pv) {
-    (void)pv;
+    os << "isMate=" << pv.isMate();
+    os << " score=" << pv.score();
+    os << " length=" << pv.length() << std::endl;
+    os << "Moves:" << std::endl;
+    for (const auto &item : pv) {
+        os << item << std::endl;
+    }
     return os;
 }

PrincipalVariation.hpp

@@ -3,21 +3,31 @@
 
 #include "Move.hpp"
 #include "Piece.hpp"
+#include "Board.hpp"
 
 #include <iosfwd>
 #include <cstddef>
+#include <vector>
 
 class PrincipalVariation {
 public:
 
-    using MoveIter = Move*;
+    using MoveIter = std::vector<Move>::const_iterator;
 
+    PrincipalVariation() = default;
+    PrincipalVariation(const std::vector<Move> &v, bool isMate);
+    PrincipalVariation(const std::vector<Move> &v, Board &board);
     bool isMate() const;
     int score() const;
 
     std::size_t length() const;
     MoveIter begin() const;
     MoveIter end() const;
+
+private:
+    std::vector<Move> mMoves;
+    bool mIsMate = false;
+    int mScore = 0;
 };
 
 std::ostream &operator<<(std::ostream &os, const PrincipalVariation &pv);

Search.cpp

@@ -0,0 +1,86 @@
+#include <iostream>
+#include "Search.hpp"
+#include "Move.hpp"
+#include "Board.hpp"
+
+#include <algorithm>
+
+int Search::search(Node *node, const Board &board, unsigned depth, int alpha, int beta) {
+
+    if (depth == 0) {
+        return evaluate(board);
+    }
+
+    auto moves = Board::MoveVec();
+    board.pseudoLegalMoves(moves);
+    if (moves.empty()) {
+        return evaluate(board);
+    }
+    std::stable_sort(moves.begin(), moves.end());
+
+    int maxValue = kNegInfinity;
+    for (auto &kMove: moves) {
+        Board nodeBoard = board;
+        nodeBoard.makeMove(kMove);
+
+        Node child(kMove);
+        child.value = search(&child, nodeBoard, depth - 1, -beta, -alpha);
+
+        auto value = -child.value;
+        if (value > maxValue) {
+            maxValue = value;
+            node->next = std::make_unique<Node>(child);
+        }
+
+        alpha = std::max(alpha, value);
+        if (alpha >= beta) {
+            break;
+        }
+    }
+
+    node->value = maxValue;
+
+    return maxValue;
+}
+
+int Search::evaluate(const Board &board) {
+
+    return board.evaluate();
+}
+
+
+PrincipalVariation Search::start(const Board &board) {
+    auto rootMoves = Board::MoveVec();
+    board.pseudoLegalMoves(rootMoves);
+    std::stable_sort(rootMoves.begin(), rootMoves.end());
+
+    if (rootMoves.size() <= 1) {
+        auto b = board;
+        return PrincipalVariation(rootMoves, b);
+    }
+
+    std::unique_ptr<RootNode> best = std::make_unique<RootNode>();
+    for (const auto &kMove: rootMoves) {
+
+        auto node = Node(kMove);
+
+        Board nodeBoard = board;
+        nodeBoard.makeMove(kMove);
+
+        auto value = -search(&node, nodeBoard, 5, kNegInfinity, kPosInfinity);
+        if (value > best->value) {
+            best->child = std::make_unique<Node>(node);
+            best->board = nodeBoard;
+            best->value = value;
+        }
+    }
+
+    auto moves = std::vector<Move>();
+    auto current = std::move(best->child);
+    do {
+        moves.push_back(current->move);
+        current = std::move(current->next);
+    } while (current);
+
+    return PrincipalVariation(moves, best->board);
+}

Search.hpp

@@ -0,0 +1,39 @@
+#ifndef CHESS_ENGINE_SEARCH_HPP
+#define CHESS_ENGINE_SEARCH_HPP
+
+#include "PrincipalVariation.hpp"
+#include "Board.hpp"
+
+#include <vector>
+#include <limits>
+
+namespace Search {
+
+const int kPosInfinity = std::numeric_limits<int>::max();
+const int kNegInfinity = std::numeric_limits<int>::min();
+
+struct Node {
+    explicit Node(const Move &move) : move(move) {
+    }
+
+    Node(Node &node) : move(node.move) {
+        next = std::move(node.next);
+        value = node.value;
+    }
+    std::unique_ptr<Node> next;
+    Move move;
+    int value = kNegInfinity;
+};
+
+struct RootNode {
+    std::unique_ptr<Node> child;
+    Board board;
+    int value = kNegInfinity;
+};
+
+int search(Node *node, const Board &board, unsigned depth, int alpha, int beta);
+PrincipalVariation start(const Board &board);
+int evaluate(const Board &board);
+}
+
+#endif //CHESS_ENGINE_SEARCH_HPP

Square.hpp

@@ -26,6 +26,9 @@ public:
     static Optional fromIndex(Index index);
     static Optional fromName(const std::string &name);
 
+    Square(Index index);
+
+
     Coordinate file() const;
     Coordinate rank() const;
     Index index() const;
@@ -40,9 +43,6 @@ public:
     static const Square A8, B8, C8, D8, E8, F8, G8, H8;
 
 private:
-
-    Square(Index index);
-
     Index mIndex;
 };
 

Tests/BitBoardTest.cpp

@@ -11,7 +11,7 @@ TEST_CASE("King attacks are correctly generated", "[Board][Fundamental]") {
     auto board = BitBoard::fromIndex(G2);
     board |= BitBoard::fromIndex(B7);
 
-    BitBoard ka = BitBoard::kingAttacks(board);
+    BitBoard ka = BitBoard::kingMoves(board);
     REQUIRE((ka == (
             BitBoard::fromIndex(G1) | BitBoard::fromIndex(G3) | BitBoard::fromIndex(H1) | BitBoard::fromIndex(H2)
                     | BitBoard::fromIndex(H3) | BitBoard::fromIndex(F1) | BitBoard::fromIndex(F2)

Tests/BoardTests.cpp

@@ -224,6 +224,18 @@ TEST_CASE_PSEUDO_MOVES("Pseudo-legal bishop moves, empty board", "[Bishop]") {
     );
 }
 
+TEST_CASE_PSEUDO_MOVES("Pseudo-legal bishop moves, empty board side", "[Bishop]") {
+    testPseudoLegalMoves(
+            // https://lichess.org/editor/B7/8/8/8/8/8/8/8_w_-_-_0_1
+            "B7/8/8/8/8/8/8/8 w - - 0 1",
+            "a8",
+            {
+                    "b7", "c6", "d5",
+                    "e4", "f3", "g2", "h1"
+            }
+    );
+}
+
 TEST_CASE_PSEUDO_MOVES("Pseudo-legal bishop moves, captures", "[Bishop]") {
     testPseudoLegalMoves(
         // https://lichess.org/editor/8/8/1p3P2/8/3B4/8/8/8_w_-_-_0_1
@@ -252,6 +264,41 @@ TEST_CASE_PSEUDO_MOVES("Pseudo-legal rook moves, empty board", "[Rook]") {
     );
 }
 
+TEST_CASE_PSEUDO_MOVES("Pseudo-legal rook moves, empty board side", "[Rook]") {
+    testPseudoLegalMoves(
+            // https://lichess.org/editor/3R4/8/8/8/8/8/8/8_w_-_-_0_1
+            "3R4/8/8/8/8/8/8/8 w - - 0 1",
+            "d8",
+            {
+                    "d1", "d2", "d3", "d4", "d5", "d6", "d7",
+                    "a8", "b8", "c8",
+                    "e8", "f8", "g8",
+                    "h8"
+            }
+    );
+}
+
+
+
+TEST_CASE_PSEUDO_MOVES("legal rook moves, king check", "[Rook]") {
+    testPseudoLegalMoves(
+// https://lichess.org/editor/5R1k/6pp/8/8/8/8/8/K7_b_-_-_0_1
+            "5R1k/6pp/8/8/8/8/8/K7 b - - 0 1",
+            "g7",
+            {}
+    );
+}
+
+TEST_CASE_PSEUDO_MOVES("legal king moves, king stale", "[Rook]") {
+    testPseudoLegalMoves(
+// https://lichess.org/editor/k7/8/8/6n1/r7/4K3/2q5/8_w_-_-_0_1
+            "k7/8/8/6n1/r7/4K3/2q5/8 w - - 0 1",
+            "e3",
+            {}
+    );
+}
+
+
 TEST_CASE_PSEUDO_MOVES("Pseudo-legal rook moves, captures", "[Rook]") {
     testPseudoLegalMoves(
         // https://lichess.org/editor/8/8/3p4/8/3R1P2/8/8/8_w_-_-_0_1

Tests/EngineTests.cpp

@@ -25,6 +25,23 @@ static void testGameEnd(const char* fen, bool isMate) {
     REQUIRE(pv.length() == 0);
 }
 
+static void testMove(const char *fen, const std::vector<std::string> &expectedMoves) {
+    auto engine = createEngine();
+    REQUIRE(engine != nullptr);
+
+    auto board = Fen::createBoard(fen);
+    REQUIRE(board.has_value());
+
+    for (const auto &moveName : expectedMoves) {
+        auto pv = engine->pv(board.value());
+        Move move = *pv.begin();
+        move.setScore(0);
+        REQUIRE(move == Move::fromUci(moveName));
+        board->makeMove(move);
+    }
+
+}
+
 TEST_CASE("Engine detects checkmate", "[Engine][Checkmate]") {
     auto fen = GENERATE(
         // https://lichess.org/editor/4R2k/6pp/8/8/8/8/8/K7_b_-_-_0_1
@@ -46,3 +63,13 @@ TEST_CASE("Engine detects stalemate", "[Engine][Stalemate]") {
 
     testGameEnd(fen, false);
 }
+
+TEST_CASE("Puzzles mateIn1_simple", "[Engine][Puzzle]") {
+    auto [fen, moves] = GENERATE(table<const char*, std::vector<std::string>>({
+        {"2bQ1k1r/1p3p2/p4b1p/4pNp1/2q5/8/PPP2PPP/1K1RR3 b - - 3 23",{"f6d8", "d1d8"}}, // https://lichess.org/gQa01loO/black#46
+        {"5rk1/ppp5/2n4p/3b2p1/6R1/P1B1P2P/1Pq5/R2Q2K1 b - - 3 29",{"c2f2"}}, // https://lichess.org/haKJxadR#57
+        {"r1b1k2r/ppp2pp1/2p5/2b1q1Bp/3PP1n1/2P5/PP2BPPP/RN1Q1RK1 b kq - 0 10",{"e5h2"}},
+        {"r3rk2/5ppQ/b1pp1q1p/p5n1/P1P5/2N5/1PB2PP1/R3R1K1 w - - 6 24", {"h7h8"}},
+    }));
+    testMove(fen, moves);
+}

Tests/FenTests.cpp

@@ -104,7 +104,7 @@ TEST_CASE("En passant square is correctly parsed", "[Fen][EnPassant]") {
         {
             "rnbqkbnr/ppppp1pp/8/8/2PPPp2/8/PP3PPP/RNBQKBNR b KQkq e3 0 3",
             Square::E3
-        }
+        },
     }));
 
     CAPTURE(fen, ep);