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Chess.hpp

The chess.hpp is a nice library from disservin

https://disservin.github.io/chess-library/

This wiki is complement of the Disservin's documentation with more examples.

The file chess.hpp is to include in you project and contains all the code.

You don't need to make and compile a library

Board

Board b(constants::STARTPOS)

generate a Board initalized as regular game

You can debug a board for example with one of the two functions, the first one display chess board from Black player, the other from White player.

These functions I have added are for test purpose.

The library is usefull to manipulate Chess Board objects.

void printBoardBlack(  Board &p )
{
 cout <<"--------"<<endl;
 for ( int i=0; i<64; i++) {
           cout << std::string(p.at(Square(i)))   ;
           if ( (i+1)%8 == 0 ) cout << endl;
        }
 cout <<"--------"<<endl;
}

void printBoardWhite(  Board &p )
{
 cout <<"--------"<<endl;
 for ( int line=7; line>=0; line--) 
 {
 for ( int col=0; col<=7; col++) {
      cout << std::string(p.at(Square(line*8+col)))   ;
        }
  cout <<endl;
 }
 cout <<"--------"<<endl;
}

The second function will display

--------
rnbqkbnr
pppppppp
........
........
........
........
PPPPPPPP
RNBQKBNR
--------

You can generate a Board from a FEN by the method

Board::Board(std::string_view fen)

or

void setFen(std::string_view fen);

From a Board you can generate a FEN by the function

std::string getFen(bool moveCounters = true);

Bitboard

BitBoard is use to see the presence of piece on a square :

• 0 : no piece
• 1 : a piece

The value 1 can be 1 black or 1 white piece on the square

BitBoard are construct from Board with one on the following methods

• us(Color color)
• them(Color color)
• all to see the non empty cases
• pieces show the presence of a piece ( with or without color, you have the choice with 2 functions.

Bitboard c= b.pieces(PieceType::ROOK);

us Color black is same a them color white

cout<<b.us(Color::WHITE)<<endl;

The us method gives the chessboard with 1 where you have pieces

00000000
00000000
00000000
00000000
00001000
00000000
11110111
11111111

The them method gives the chessboard with 1 whee your oppenent has pieces

The methods to produce Bitboard are all() and occ()

PackedBoard

The are also Packboard a concurent of FEN not readable but more compact.

Moves

Presentation

You can make a move on the board with makeMove(move)

Board b(constants::STARTPOS)
Move m;
m.uci::uciToMove(board,"e2e4");
b.makemove(move)

uciToMove read the move in e2e4 syntax without any information about the piece unless the piece on the departure square : e2 ie a pawn.

The Move will be seen with the method printBoardWhite

You can add many moves :

m=uci::uciToMove(b,"d7d5");b.makeMove(m);list.add(m);
m=uci::uciToMove(b,"e4d5");b.makeMove(m);list.add(m);

But wih this method you will not be able to suppress moves or to suppress a move.

We will see Movelist who is a list of moves.

If you add an erroneous move you will have a error message.

You can unmake a move by the function unmakeMove(const Move move);

Functions with moves

• isCapture : check if a move is a capture, enpassant moves are also considered captures.

bool isCapture(const Move move);

Miscellaneous

• Color sideToMove() give the side to move
• bool isRepetition(int count = 2); move is a repetition ?
• bool isInsufficientMaterial();

cout<<b.isInsufficientMaterial()<<endl;

• Square : at

Square s(Rank::RANK_1,File::FILE_A);
cout<<"ok :"<<b.at(s)<<endl;

• CastlingRights castlingRights();

cout<<b.getCastleString()<<endl;

Return KQk for example to inform : King white side castle is possible, Queen black side castle is possible and King black side is also possible but not Queen black side