--- /dev/null
+class CheckeredRules extends ChessRules
+{
+ static getPpath(b)
+ {
+ return b[0]=='c' ? "Checkered/"+b : b;
+ }
+
+ static board2fen(b)
+ {
+ const checkered_codes = {
+ 'p': 's',
+ 'q': 't',
+ 'r': 'u',
+ 'b': 'c',
+ 'n': 'o',
+ };
+ if (b[0]=="c")
+ return checkered_codes[b[1]];
+ return ChessRules.board2fen(b);
+ }
+
+ static fen2board(f)
+ {
+ // Tolerate upper-case versions of checkered pieces (why not?)
+ const checkered_pieces = {
+ 's': 'p',
+ 'S': 'p',
+ 't': 'q',
+ 'T': 'q',
+ 'u': 'r',
+ 'U': 'r',
+ 'c': 'b',
+ 'C': 'b',
+ 'o': 'n',
+ 'O': 'n',
+ };
+ if (Object.keys(checkered_pieces).includes(f))
+ return 'c'+checkered_pieces[f];
+ return ChessRules.fen2board(f);
+ }
+
+ static get PIECES()
+ {
+ return ChessRules.PIECES.concat(['s','t','u','c','o']);
+ }
+
+ static IsGoodFlags(flags)
+ {
+ // 4 for castle + 16 for pawns
+ return !!flags.match(/^[01]{20,20}$/);
+ }
+
+ setFlags(fenflags)
+ {
+ super.setFlags(fenflags); //castleFlags
+ this.pawnFlags =
+ {
+ "w": _.map(_.range(8), i => true), //pawns can move 2 squares?
+ "b": _.map(_.range(8), i => true)
+ };
+ if (!fenflags)
+ return;
+ const flags = fenflags.substr(4); //skip first 4 digits, for castle
+ for (let c of ['w','b'])
+ {
+ for (let i=0; i<8; i++)
+ this.pawnFlags[c][i] = (flags.charAt((c=='w'?0:8)+i) == '1');
+ }
+ }
+
+ aggregateFlags()
+ {
+ return [this.castleFlags, this.pawnFlags];
+ }
+
+ disaggregateFlags(flags)
+ {
+ this.castleFlags = flags[0];
+ this.pawnFlags = flags[1];
+ }
+
+ canTake([x1,y1], [x2,y2])
+ {
+ const color1 = this.getColor(x1,y1);
+ const color2 = this.getColor(x2,y2);
+ // Checkered aren't captured
+ return color1 != color2 && color2 != 'c' && (color1 != 'c' || color2 != this.turn);
+ }
+
+ // Post-processing: apply "checkerization" of standard moves
+ getPotentialMovesFrom([x,y])
+ {
+ let standardMoves = super.getPotentialMovesFrom([x,y]);
+ const lastRank = this.turn == "w" ? 0 : 7;
+ if (this.getPiece(x,y) == V.KING)
+ return standardMoves; //king has to be treated differently (for castles)
+ let moves = [];
+ standardMoves.forEach(m => {
+ if (m.vanish[0].p == V.PAWN)
+ {
+ if (Math.abs(m.end.x-m.start.x)==2 && !this.pawnFlags[this.turn][m.start.y])
+ return; //skip forbidden 2-squares jumps
+ if (this.board[m.end.x][m.end.y] == V.EMPTY && m.vanish.length==2
+ && this.getColor(m.start.x,m.start.y) == 'c')
+ {
+ return; //checkered pawns cannot take en-passant
+ }
+ }
+ if (m.vanish.length == 1)
+ moves.push(m); //no capture
+ else
+ {
+ // A capture occured (m.vanish.length == 2)
+ m.appear[0].c = "c";
+ moves.push(m);
+ if (m.appear[0].p != m.vanish[1].p //avoid promotions (already treated):
+ && (m.vanish[0].p != V.PAWN || m.end.x != lastRank))
+ {
+ // Add transformation into captured piece
+ let m2 = JSON.parse(JSON.stringify(m));
+ m2.appear[0].p = m.vanish[1].p;
+ moves.push(m2);
+ }
+ }
+ });
+ return moves;
+ }
+
+ canIplay(side, [x,y])
+ {
+ return (side == this.turn && [side,'c'].includes(this.getColor(x,y)));
+ }
+
+ // Does m2 un-do m1 ? (to disallow undoing checkered moves)
+ oppositeMoves(m1, m2)
+ {
+ return m1.appear.length == 1 && m2.appear.length == 1
+ && m1.vanish.length == 1 && m2.vanish.length == 1
+ && m1.start.x == m2.end.x && m1.end.x == m2.start.x
+ && m1.start.y == m2.end.y && m1.end.y == m2.start.y
+ && m1.appear[0].c == m2.vanish[0].c && m1.appear[0].p == m2.vanish[0].p
+ && m1.vanish[0].c == m2.appear[0].c && m1.vanish[0].p == m2.appear[0].p;
+ }
+
+ filterValid(moves)
+ {
+ if (moves.length == 0)
+ return [];
+ const color = this.turn;
+ return moves.filter(m => {
+ const L = this.moves.length;
+ if (L > 0 && this.oppositeMoves(this.moves[L-1], m))
+ return false;
+ this.play(m);
+ const res = !this.underCheck(color);
+ this.undo(m);
+ return res;
+ });
+ }
+
+ isAttackedByPawn([x,y], colors)
+ {
+ for (let c of colors)
+ {
+ const color = (c=="c" ? this.turn : c);
+ let pawnShift = (color=="w" ? 1 : -1);
+ if (x+pawnShift>=0 && x+pawnShift<8)
+ {
+ for (let i of [-1,1])
+ {
+ if (y+i>=0 && y+i<8 && this.getPiece(x+pawnShift,y+i)==V.PAWN
+ && this.getColor(x+pawnShift,y+i)==c)
+ {
+ return true;
+ }
+ }
+ }
+ }
+ return false;
+ }
+
+ underCheck(color)
+ {
+ return this.isAttacked(this.kingPos[color], [V.GetOppCol(color),'c']);
+ }
+
+ getCheckSquares(color)
+ {
+ // Artifically change turn, for checkered pawns
+ this.turn = V.GetOppCol(color);
+ const kingAttacked = this.isAttacked(
+ this.kingPos[color], [V.GetOppCol(color),'c']);
+ let res = kingAttacked
+ ? [JSON.parse(JSON.stringify(this.kingPos[color]))] //need to duplicate!
+ : [];
+ this.turn = color;
+ return res;
+ }
+
+ updateVariables(move)
+ {
+ super.updateVariables(move);
+ // Does this move turn off a 2-squares pawn flag?
+ const secondRank = [1,6];
+ if (secondRank.includes(move.start.x) && move.vanish[0].p == V.PAWN)
+ this.pawnFlags[move.start.x==6 ? "w" : "b"][move.start.y] = false;
+ }
+
+ checkGameEnd()
+ {
+ const color = this.turn;
+ // Artifically change turn, for checkered pawns
+ this.turn = V.GetOppCol(this.turn);
+ const res = this.isAttacked(this.kingPos[color], [V.GetOppCol(color),'c'])
+ ? (color == "w" ? "0-1" : "1-0")
+ : "1/2";
+ this.turn = V.GetOppCol(this.turn);
+ return res;
+ }
+
+ evalPosition()
+ {
+ let evaluation = 0;
+ //Just count material for now, considering checkered neutral (...)
+ for (let i=0; i<V.size.x; i++)
+ {
+ for (let j=0; j<V.size.y; j++)
+ {
+ if (this.board[i][j] != V.EMPTY)
+ {
+ const sqColor = this.getColor(i,j);
+ const sign = sqColor == "w" ? 1 : (sqColor=="b" ? -1 : 0);
+ evaluation += sign * V.VALUES[this.getPiece(i,j)];
+ }
+ }
+ }
+ return evaluation;
+ }
+
+ static GenRandInitFen()
+ {
+ const randFen = ChessRules.GenRandInitFen();
+ // Add 16 pawns flags:
+ return randFen.replace(" w 1111", " w 11111111111111111111");
+ }
+
+ getFlagsFen()
+ {
+ let fen = super.getFlagsFen();
+ // Add pawns flags
+ for (let c of ['w','b'])
+ {
+ for (let i=0; i<8; i++)
+ fen += this.pawnFlags[c][i] ? '1' : '0';
+ }
+ return fen;
+ }
+
+ getNotation(move)
+ {
+ if (move.appear.length == 2)
+ {
+ // Castle
+ if (move.end.y < move.start.y)
+ return "0-0-0";
+ else
+ return "0-0";
+ }
+
+ // Translate final square
+ const finalSquare = V.CoordsToSquare(move.end);
+
+ const piece = this.getPiece(move.start.x, move.start.y);
+ if (piece == V.PAWN)
+ {
+ // Pawn move
+ let notation = "";
+ if (move.vanish.length > 1)
+ {
+ // Capture
+ const startColumn = V.CoordToColumn(move.start.y);
+ notation = startColumn + "x" + finalSquare +
+ "=" + move.appear[0].p.toUpperCase();
+ }
+ else //no capture
+ {
+ notation = finalSquare;
+ if (move.appear.length > 0 && piece != move.appear[0].p) //promotion
+ notation += "=" + move.appear[0].p.toUpperCase();
+ }
+ return notation;
+ }
+
+ else
+ {
+ // Piece movement
+ return piece.toUpperCase() + (move.vanish.length > 1 ? "x" : "") + finalSquare
+ + (move.vanish.length > 1 ? "=" + move.appear[0].p.toUpperCase() : "");
+ }
+ }
+}
projects / vchess.git / blobdiff