static get CAMEL() { return 'c'; }
static get WILDEBEEST() { return 'w'; }
- static get PIECES() {
+ static get PIECES()
+ {
return ChessRules.PIECES.concat([V.CAMEL,V.WILDEBEEST]);
}
- static get steps() {
+ static get steps()
+ {
return Object.assign(
ChessRules.steps, //add camel moves:
{'c': [ [-3,-1],[-3,1],[-1,-3],[-1,3],[1,-3],[1,3],[3,-1],[3,1] ]}
);
}
+ static IsGoodEnpassant(enpassant)
+ {
+ if (enpassant != "-")
+ {
+ const squares = enpassant.split(",");
+ if (squares.length > 2)
+ return false;
+ for (let sq of squares)
+ {
+ const ep = V.SquareToCoords(sq);
+ if (isNaN(ep.x) || !V.OnBoard(ep))
+ return false;
+ }
+ }
+ return true;
+ }
+
+ // There may be 2 enPassant squares (if pawn jump 3 squares)
+ getEnpassantFen()
+ {
+ const L = this.epSquares.length;
+ if (!this.epSquares[L-1])
+ return "-"; //no en-passant
+ let res = "";
+ this.epSquares[L-1].forEach(sq => {
+ res += V.CoordsToSquare(sq) + ",";
+ });
+ return res.slice(0,-1); //remove last comma
+ }
+
// En-passant after 2-sq or 3-sq jumps
- getEpSquare(move)
+ getEpSquare(moveOrSquare)
{
+ if (!moveOrSquare)
+ return undefined;
+ if (typeof moveOrSquare === "string")
+ {
+ const square = moveOrSquare;
+ if (square == "-")
+ return undefined;
+ let res = [];
+ square.split(",").forEach(sq => {
+ res.push(V.SquareToCoords(sq));
+ });
+ return res;
+ }
+ // Argument is a move:
+ const move = moveOrSquare;
const [sx,sy,ex] = [move.start.x,move.start.y,move.end.x];
if (this.getPiece(sx,sy) == V.PAWN && Math.abs(sx - ex) >= 2)
{
const color = this.turn;
let moves = [];
const [sizeX,sizeY] = [V.size.x,V.size.y];
- const shift = (color == "w" ? -1 : 1);
+ const shiftX = (color == "w" ? -1 : 1);
const startRanks = (color == "w" ? [sizeX-2,sizeX-3] : [1,2]);
const lastRank = (color == "w" ? 0 : sizeX-1);
+ const finalPieces = x + shiftX == lastRank
+ ? [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN]
+ : [V.PAWN];
- if (x+shift >= 0 && x+shift < sizeX && x+shift != lastRank)
+ if (this.board[x+shiftX][y] == V.EMPTY)
{
- // Normal moves
- if (this.board[x+shift][y] == V.EMPTY)
+ // One square forward
+ for (let piece of finalPieces)
+ moves.push(this.getBasicMove([x,y], [x+shiftX,y], {c:color,p:piece}));
+ if (startRanks.includes(x))
{
- moves.push(this.getBasicMove([x,y], [x+shift,y]));
- if (startRanks.includes(x) && this.board[x+2*shift][y] == V.EMPTY)
+ if (this.board[x+2*shiftX][y] == V.EMPTY)
{
// Two squares jump
- moves.push(this.getBasicMove([x,y], [x+2*shift,y]));
- if (x == startRanks[0] && this.board[x+3*shift][y] == V.EMPTY)
+ moves.push(this.getBasicMove([x,y], [x+2*shiftX,y]));
+ if (x==startRanks[0] && this.board[x+3*shiftX][y] == V.EMPTY)
{
- // 3-squares jump
- moves.push(this.getBasicMove([x,y], [x+3*shift,y]));
+ // Three squares jump
+ moves.push(this.getBasicMove([x,y], [x+3*shiftX,y]));
}
}
}
- // Captures
- if (y>0 && this.canTake([x,y], [x+shift,y-1])
- && this.board[x+shift][y-1] != V.EMPTY)
- {
- moves.push(this.getBasicMove([x,y], [x+shift,y-1]));
- }
- if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1])
- && this.board[x+shift][y+1] != V.EMPTY)
- {
- moves.push(this.getBasicMove([x,y], [x+shift,y+1]));
- }
}
-
- if (x+shift == lastRank)
+ // Captures
+ for (let shiftY of [-1,1])
{
- // Promotion
- let promotionPieces = [V.QUEEN,V.WILDEBEEST];
- promotionPieces.forEach(p => {
- // Normal move
- if (this.board[x+shift][y] == V.EMPTY)
- moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:p}));
- // Captures
- if (y>0 && this.canTake([x,y], [x+shift,y-1])
- && this.board[x+shift][y-1] != V.EMPTY)
- {
- moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:color,p:p}));
- }
- if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1])
- && this.board[x+shift][y+1] != V.EMPTY)
+ if (y + shiftY >= 0 && y + shiftY < sizeY
+ && this.board[x+shiftX][y+shiftY] != V.EMPTY
+ && this.canTake([x,y], [x+shiftX,y+shiftY]))
+ {
+ for (let piece of finalPieces)
{
- moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:color,p:p}));
+ moves.push(this.getBasicMove([x,y], [x+shiftX,y+shiftY],
+ {c:color,p:piece}));
}
- });
+ }
}
// En passant
const Lep = this.epSquares.length;
- const epSquare = Lep>0 ? this.epSquares[Lep-1] : undefined;
+ const epSquare = this.epSquares[Lep-1];
if (!!epSquare)
{
for (let epsq of epSquare)
{
// TODO: some redundant checks
- if (epsq.x == x+shift && Math.abs(epsq.y - y) == 1)
+ if (epsq.x == x+shiftX && Math.abs(epsq.y - y) == 1)
{
- let epStep = epsq.y - y;
- var enpassantMove = this.getBasicMove([x,y], [x+shift,y+epStep]);
+ var enpassantMove = this.getBasicMove([x,y], [epsq.x,epsq.y]);
+ // WARNING: the captured pawn may be diagonally behind us,
+ // if it's a 3-squares jump and we take on 1st passing square
+ const px = (this.board[x][epsq.y] != V.EMPTY ? x : x - shiftX);
enpassantMove.vanish.push({
- x: x,
- y: y+epStep,
+ x: px,
+ y: epsq.y,
p: 'p',
- c: this.getColor(x,y+epStep)
+ c: this.getColor(px,epsq.y)
});
moves.push(enpassantMove);
}
pieces[c][knight2Pos] = 'n';
pieces[c][rook2Pos] = 'r';
}
- let fen = pieces["b"].join("") +
+ return pieces["b"].join("") +
"/ppppppppppp/11/11/11/11/11/11/PPPPPPPPPPP/" +
pieces["w"].join("").toUpperCase() +
- " 1111";
- return fen;
+ " w 1111 -";
}
}
+
+const VariantRules = WildebeestRules;