const parsedFen = V.ParseFen(fen);
this.setFlags(parsedFen.flags);
if (parsedFen.enpassant == "-")
- this.epSquares = [ [undefined,undefined] ];
+ this.epSquares = [ [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);
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
+ const finalPieces = x + shiftX == lastRank
+ ? [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN]
+ : [V.PAWN];
- if (x+shiftX >= 0 && x+shiftX < sizeX) //TODO: always true
+ // One square forward
+ if (this.board[x+shiftX][y] == V.EMPTY)
{
- 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)
{
- 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]));
- }
+ moves.push(this.getBasicMove([x,y], [x+shiftX,y],
+ {c:pawnColor,p:piece}));
}
- // Captures
- for (let shiftY of [-1,1])
+ // Next condition because pawns on 1st rank can generally jump
+ if ([startRank,firstRank].includes(x)
+ && this.board[x+2*shiftX][y] == 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]))
+ // 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)
{
- for (let piece of finalPieces)
- {
- moves.push(this.getBasicMove([x,y], [x+shiftX,y+shiftY],
- {c:pawnColor,p:piece}));
- }
+ moves.push(this.getBasicMove([x,y], [x+shiftX,y+shiftY],
+ {c:pawnColor,p:piece}));
}
}
}
{
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)
move.color = this.turn;
}
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);
+ const epSq = this.getEpSquare(move);
if (this.startAtFirstMove && this.moves.length == 0)
+ {
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(this.getOppCol(this.turn)))
{
- this.epSquares[this.epSquares.length-1].push(undefined);
this.turn = this.getOppCol(this.turn);
+ this.epSquares.push([epSq]);
move.checkOnSubturn1 = true;
}
else
{
if (this.subTurn == 2)
+ {
this.turn = this.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.moves.push(move);
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";
+ this.epSquares.pop();
+ }
else if (move.checkOnSubturn1)
{
this.turn = this.getOppCol(this.turn);
this.subTurn = 1;
+ this.epSquares.pop();
}
else
{
if (this.subTurn == 1)
+ {
this.turn = this.getOppCol(this.turn);
+ let lastEpsq = this.epSquares[this.epSquares.length-1];
+ lastEpsq.pop();
+ }
+ else
+ this.epSquares.pop();
this.subTurn = 3 - this.subTurn;
}
this.moves.pop();
// Search best (half) move for opponent turn
const getBestMoveEval = () => {
+ const turnBefore = this.turn + this.subTurn;
let moves = this.getAllValidMoves();
if (moves.length == 0)
{
for (let m of moves)
{
this.play(m);
- this.turn = color; //very artificial...
+ // 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();
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;
// 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)
{
return pgn;
}
-
}
const VariantRules = MarseilleRules;
projects / vchess.git / blobdiff