+++ /dev/null
-class MarseilleRules extends ChessRules
-{
- 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()
- {
- 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] ];
- else
- {
- let res = [];
- const squares = parsedFen.enpassant.split(",");
- for (let sq of squares)
- res.push(V.SquareToCoords(sq));
- 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.turn = fullTurn[0];
- this.subTurn = (fullTurn[1] || 0); //"w0" = special code for first move in game
- }
-
- 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 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:color,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:color,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;
- const oppCol = V.GetOppCol(color);
- for (let sq of epSqs)
- {
- if (this.subTurn == 1 || (epSqs.length == 2 &&
- // Was this en-passant capture already played at subturn 1 ?
- // (Or maybe the opponent filled the en-passant square with a piece)
- this.board[epSqs[0].x][epSqs[0].y] != V.EMPTY))
- {
- if (sq.x == x+shiftX && Math.abs(sq.y - y) == 1
- // Add condition "enemy pawn must be present"
- && this.getPiece(x,sq.y) == V.PAWN && this.getColor(x,sq.y) == oppCol)
- {
- let epMove = this.getBasicMove([x,y], [sq.x,sq.y]);
- epMove.vanish.push({
- x: x,
- y: sq.y,
- p: 'p',
- c: oppCol
- });
- moves.push(epMove);
- }
- }
- }
-
- return moves;
- }
-
- play(move)
- {
- move.flags = JSON.stringify(this.aggregateFlags());
- move.turn = this.turn + this.subturn;
- V.PlayOnBoard(this.board, move);
- const epSq = this.getEpSquare(move);
- if (this.subTurn == 0) //first move in game
- {
- this.turn = "b";
- this.epSquares.push([epSq]);
- }
- // Does this move give check on subturn 1? If yes, skip subturn 2
- else if (this.subTurn==1 && this.underCheck(V.GetOppCol(this.turn)))
- {
- this.turn = V.GetOppCol(this.turn);
- this.epSquares.push([epSq]);
- move.checkOnSubturn1 = true;
- }
- else
- {
- if (this.subTurn == 2)
- {
- this.turn = V.GetOppCol(this.turn);
- let lastEpsq = this.epSquares[this.epSquares.length-1];
- lastEpsq.push(epSq);
- }
- else
- this.epSquares.push([epSq]);
- this.subTurn = 3 - this.subTurn;
- }
- this.updateVariables(move);
- }
-
- undo(move)
- {
- this.disaggregateFlags(JSON.parse(move.flags));
- V.UndoOnBoard(this.board, move);
- if (move.turn[1] == '0' || move.checkOnSubturn1 || this.subTurn == 2)
- this.epSquares.pop();
- else //this.subTurn == 1
- {
- let lastEpsq = this.epSquares[this.epSquares.length-1];
- lastEpsq.pop();
- }
- this.turn = move.turn[0];
- this.subTurn = parseInt(move.turn[1]);
- this.unupdateVariables(move);
- }
-
- // NOTE: GenRandInitFen() is OK,
- // since at first move turn indicator is just "w"
-
- static get VALUES()
- {
- return {
- 'p': 1,
- 'r': 5,
- 'n': 3,
- 'b': 3,
- 'q': 7, //slightly less than in orthodox game
- 'k': 1000
- };
- }
-
- // No alpha-beta here, just adapted min-max at depth 2(+1)
- getComputerMove()
- {
- if (this.subTurn == 2)
- return null; //TODO: imperfect interface setup
-
- const maxeval = V.INFINITY;
- const color = this.turn;
- const oppCol = V.GetOppCol(this.turn);
-
- // Search best (half) move for opponent turn
- const getBestMoveEval = () => {
- const turnBefore = this.turn + this.subTurn;
- 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);
- // Now turn is oppCol,2 if m doesn't give check
- // Otherwise it's color,1. In both cases the next test makes sense
- 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.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.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++)
- {
- 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;
- }
-}
projects / vchess.git / blobdiff