if (!V.IsGoodPosition(fenParsed.position))
return false;
// 2) Check turn
- if (!fenParsed.turn || !["w","b"].includes(fenParsed.turn))
+ if (!fenParsed.turn || !V.IsGoodTurn(fenParsed.turn))
return false;
// 3) Check flags
if (V.HasFlags && (!fenParsed.flags || !V.IsGoodFlags(fenParsed.flags)))
return false;
// 4) Check enpassant
- if (V.HasEnpassant)
+ if (V.HasEnpassant &&
+ (!fenParsed.enpassant || !V.IsGoodEnpassant(fenParsed.enpassant)))
{
- if (!fenParsed.enpassant)
- return false;
- if (fenParsed.enpassant != "-")
- {
- const ep = V.SquareToCoords(fenParsed.enpassant);
- if (isNaN(ep.x) || !V.OnBoard(ep))
- return false;
- }
+ return false;
}
return true;
}
return true;
}
+ // For FEN checking
+ static IsGoodTurn(turn)
+ {
+ return ["w","b"].includes(turn);
+ }
+
// For FEN checking
static IsGoodFlags(flags)
{
return !!flags.match(/^[01]{4,4}$/);
}
+ static IsGoodEnpassant(enpassant)
+ {
+ if (enpassant != "-")
+ {
+ const ep = V.SquareToCoords(fenParsed.enpassant);
+ if (isNaN(ep.x) || !V.OnBoard(ep))
+ return false;
+ }
+ return true;
+ }
+
// 3 --> d (column number to letter)
static CoordToColumn(colnum)
{
// Return current fen (game state)
getFen()
{
- return this.getBaseFen() + " " + this.turn +
+ return this.getBaseFen() + " " + this.getTurnFen() +
(V.HasFlags ? (" " + this.getFlagsFen()) : "") +
(V.HasEnpassant ? (" " + this.getEnpassantFen()) : "");
}
return position;
}
+ getTurnFen()
+ {
+ return this.turn;
+ }
+
// Flags part of the FEN string
getFlagsFen()
{
this.moves = moves;
const fenParsed = V.ParseFen(fen);
this.board = V.GetBoard(fenParsed.position);
- this.turn = (fenParsed.turn || "w");
+ this.turn = fenParsed.turn[0]; //[0] to work with MarseilleRules
this.setOtherVariables(fen);
}
updateVariables(move)
{
const piece = move.vanish[0].p;
- const c = this.getOppCol(this.turn); //'move.vanish[0].c' doesn't work for Checkered
+ let c = move.vanish[0].c;
+ if (c == "c") //if (!["w","b"].includes(c))
+ {
+ // 'c = move.vanish[0].c' doesn't work for Checkered
+ c = this.getOppCol(this.turn);
+ }
const firstRank = (c == "w" ? V.size.x-1 : 0);
// Update king position + flags
if (!this.isAttacked(this.kingPos[color], [this.getOppCol(color)]))
return "1/2";
// OK, checkmate
- return color == "w" ? "0-1" : "1-0";
+ return (color == "w" ? "0-1" : "1-0");
}
///////////////
-//TODO:
-//adapter alphabeta (dans baserules ? --> basé sur turn OK)
-// le reste == standard
-
class MarseilleRules extends ChessRules
{
- // TODO: fen indication pour turn : w1, w2 ou b1, ou b2 (about to play 1st or 2nd sub-turn)
- // + quelque chose pour indiquer si c'est le tout premier coup ("w" sans + d'indications)
- //
- // this.turn == "w" ou "b"
- // this.subTurn == 0 ou 1 (ou 1 et 2)
- //
- // Alpha-beta ?
+ 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;
+ }
+
+ getTurnFen()
+ {
+ if (this.startAtFirstMove && this.moves.length==0)
+ return "w";
+ return this.turn + this.subTurn;
+ }
+
+ // There may be 2 enPassant squares (if 2 pawns jump 2 squares in same turn)
+ getEnpassantFen()
+ {
+ const L = this.epSquares.length;
+ if (this.epSquares[L-1].every(epsq => epsq === undefined))
+ return "-"; //no en-passant
+ let res = "";
+ this.epSquares[L-1].forEach(epsq => {
+ if (!!epsq)
+ res += V.CoordsToSquare(epsq) + ",";
+ });
+ return res.slice(0,-1); //remove last comma
+ }
+
+ setOtherVariables(fen)
+ {
+ const parsedFen = V.ParseFen(fen);
+ this.setFlags(parsedFen.flags);
+ if (parsedFen.enpassant == "-")
+ this.epSquares = [ [undefined,undefined] ];
+ else
+ {
+ let res = [];
+ const squares = parsedFen.enpassant.split(",");
+ for (let sq of squares)
+ res.push(V.SquareToCoords(sq));
+ if (res.length == 1)
+ res.push(undefined); //always 2 slots in epSquares[i]
+ this.epSquares = [ res ];
+ }
+ this.scanKingsRooks(fen);
+ // Extract subTurn from turn indicator: "w" (first move), or
+ // "w1" or "w2" white subturn 1 or 2, and same for black
+ const fullTurn = V.ParseFen(fen).turn;
+ this.startAtFirstMove = (fullTurn == "w");
+ this.turn = fullTurn[0];
+ this.subTurn = (fullTurn[1] || 1);
+ }
+
+ getPotentialPawnMoves([x,y])
+ {
+ const color = this.turn;
+ let moves = [];
+ const [sizeX,sizeY] = [V.size.x,V.size.y];
+ const shiftX = (color == "w" ? -1 : 1);
+ const firstRank = (color == 'w' ? sizeX-1 : 0);
+ const startRank = (color == "w" ? sizeX-2 : 1);
+ const lastRank = (color == "w" ? 0 : sizeX-1);
+ const pawnColor = this.getColor(x,y); //can be different for checkered
+
+ if (x+shiftX >= 0 && x+shiftX < sizeX) //TODO: always true
+ {
+ const finalPieces = x + shiftX == lastRank
+ ? [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN]
+ : [V.PAWN]
+ // One square forward
+ if (this.board[x+shiftX][y] == V.EMPTY)
+ {
+ for (let piece of finalPieces)
+ {
+ moves.push(this.getBasicMove([x,y], [x+shiftX,y],
+ {c:pawnColor,p:piece}));
+ }
+ // Next condition because pawns on 1st rank can generally jump
+ if ([startRank,firstRank].includes(x)
+ && this.board[x+2*shiftX][y] == V.EMPTY)
+ {
+ // Two squares jump
+ moves.push(this.getBasicMove([x,y], [x+2*shiftX,y]));
+ }
+ }
+ // Captures
+ for (let shiftY of [-1,1])
+ {
+ 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+shiftX,y+shiftY],
+ {c:pawnColor,p:piece}));
+ }
+ }
+ }
+ }
+
+ // En passant: always OK if subturn 1,
+ // OK on subturn 2 only if enPassant was played at subturn 1
+ // (and if there are two e.p. squares available).
+ const Lep = this.epSquares.length;
+ const epSquares = this.epSquares[Lep-1]; //always at least one element
+ let epSqs = [];
+ epSquares.forEach(sq => {
+ if (!!sq)
+ epSqs.push(sq);
+ });
+ if (epSqs.length == 0)
+ return moves;
+ for (let sq of epSqs)
+ {
+ if (this.subTurn == 1 || (epSqs.length == 2 &&
+ // Was this en-passant capture already played at subturn 1 ?
+ this.board[epSqs[0].x][epSqs[0].y] != V.EMPTY))
+ {
+ if (sq.x == x+shiftX && Math.abs(sq.y - y) == 1)
+ {
+ let epMove = this.getBasicMove([x,y], [sq.x,sq.y]);
+ epMove.vanish.push({
+ x: x,
+ y: sq.y,
+ p: 'p',
+ c: this.getColor(x,sq.y)
+ });
+ moves.push(epMove);
+ }
+ }
+ }
+
+ return moves;
+ }
+
+ play(move, ingame)
+ {
+// console.log("play " + this.getNotation(move));
+// console.log(this.turn + " "+ this.subTurn);
+ if (!!ingame)
+ move.notation = [this.getNotation(move), this.getLongNotation(move)];
+ move.flags = JSON.stringify(this.aggregateFlags());
+ let lastEpsq = this.epSquares[this.epSquares.length-1];
+ const epSq = this.getEpSquare(move);
+ if (lastEpsq.length == 1)
+ lastEpsq.push(epSq);
+ else
+ {
+ // New turn
+ let newEpsqs = [epSq];
+ if (this.startAtFirstMove && this.moves.length == 0)
+ newEpsqs.push(undefined); //at first move, to force length==2 (TODO)
+ this.epSquares.push(newEpsqs);
+ }
+ V.PlayOnBoard(this.board, move);
+ if (this.startAtFirstMove && this.moves.length == 0)
+ this.turn = "b";
+ // Does this move give check on subturn 1? If yes, skip subturn 2
+ else if (this.subTurn==1 && this.underCheck(this.getOppCol(this.turn)))
+ {
+ this.epSquares[this.epSquares.length-1].push(undefined);
+ this.turn = this.getOppCol(this.turn);
+ move.checkOnSubturn1 = true;
+ }
+ else
+ {
+ if (this.subTurn == 2)
+ this.turn = this.getOppCol(this.turn);
+ this.subTurn = 3 - this.subTurn;
+ }
+ this.moves.push(move);
+ this.updateVariables(move);
+ if (!!ingame)
+ move.hash = hex_md5(this.getFen());
+ //console.log(move.checkOnSubturn1 + " " +this.turn + " "+ this.subTurn);
+ }
+
+ undo(move)
+ {
+ this.disaggregateFlags(JSON.parse(move.flags));
+ let lastEpsq = this.epSquares[this.epSquares.length-1];
+ if (lastEpsq.length == 2)
+ {
+ if (!!move.checkOnSubturn1 ||
+ (this.startAtFirstMove && this.moves.length == 1))
+ {
+ this.epSquares.pop(); //remove real + artificial e.p. squares
+ }
+ else
+ lastEpsq.pop();
+ }
+ else
+ this.epSquares.pop();
+ V.UndoOnBoard(this.board, move);
+ if (this.startAtFirstMove && this.moves.length == 1)
+ this.turn = "w";
+ else if (move.checkOnSubturn1)
+ {
+ this.turn = this.getOppCol(this.turn);
+ this.subTurn = 1;
+ }
+ else
+ {
+ if (this.subTurn == 1)
+ this.turn = this.getOppCol(this.turn);
+ this.subTurn = 3 - this.subTurn;
+ }
+ this.moves.pop();
+ this.unupdateVariables(move);
+// console.log("UNDO " + this.getNotation(move));
+// console.log(this.turn + " "+ this.subTurn);
+ }
+
+ // NOTE: GenRandInitFen() is OK,
+ // since at first move turn indicator is just "w"
+
+ // No alpha-beta here, just adapted min-max at depth 2(+1)
+ getComputerMove()
+ {
+ const maxeval = V.INFINITY;
+ const color = this.turn;
+ const oppCol = this.getOppCol(this.turn);
+
+ // Search best (half) move for opponent turn
+ const getBestMoveEval = () => {
+ let moves = this.getAllValidMoves();
+ if (moves.length == 0)
+ {
+ const score = this.checkGameEnd();
+ if (score == "1/2")
+ return 0;
+ return maxeval * (score == "1-0" ? 1 : -1);
+ }
+ let res = (oppCol == "w" ? -maxeval : maxeval);
+ for (let m of moves)
+ {
+ this.play(m);
+ this.turn = color; //very artificial...
+ if (!this.atLeastOneMove())
+ {
+ const score = this.checkGameEnd();
+ if (score == "1/2")
+ res = (oppCol == "w" ? Math.max(res, 0) : Math.min(res, 0));
+ else
+ {
+ // Found a mate
+ this.turn = oppCol;
+ this.undo(m);
+ return maxeval * (score == "1-0" ? 1 : -1);
+ }
+ }
+ const evalPos = this.evalPosition();
+ res = (oppCol == "w" ? Math.max(res, evalPos) : Math.min(res, evalPos));
+ this.turn = oppCol;
+ this.undo(m);
+ }
+ return res;
+ };
+
+ let moves11 = this.getAllValidMoves();
+ let doubleMoves = [];
+ // Rank moves using a min-max at depth 2
+ for (let i=0; i<moves11.length; i++)
+ {
+ moves11[i].eval = (color=="w" ? -1 : 1) * maxeval;
+ this.play(moves11[i]);
+ if (this.turn != color)
+ {
+ // We gave check with last move: search the best opponent move
+ doubleMoves.push({moves:[moves11[i]], eval:getBestMoveEval()});
+ }
+ else
+ {
+ let moves12 = this.getAllValidMoves();
+ for (let j=0; j<moves12.length; j++)
+ {
+ this.play(moves12[j]);
+ doubleMoves.push({
+ moves:[moves11[i],moves12[j]],
+ eval:getBestMoveEval()});
+ this.undo(moves12[j]);
+ }
+ }
+ this.undo(moves11[i]);
+ }
+
+ doubleMoves.sort( (a,b) => {
+ return (color=="w" ? 1 : -1) * (b.eval - a.eval); });
+ let candidates = [0]; //indices of candidates moves
+ for (let i=1;
+ i<doubleMoves.length && doubleMoves[i].eval == doubleMoves[0].eval;
+ i++)
+ {
+ candidates.push(i);
+ }
+ const selected = doubleMoves[_.sample(candidates, 1)].moves;
+ if (selected.length == 1)
+ return selected[0];
+ return selected;
+ }
}
const VariantRules = MarseilleRules;
projects / vchess.git / commitdiff