class CheckeredRules extends ChessRules
{
- // Path to pieces
static getPpath(b)
{
return b[0]=='c' ? "Checkered/"+b : b;
}
+
static board2fen(b)
{
const checkered_codes = {
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 GetFlags(fen)
+ static get PIECES()
{
- let flags = [
- ChessRules.GetFlags(fen), //castle
- {
- "w": new Array(8), //pawns can move 2 squares
- "b": new Array(8)
- }
- ];
- const fenFlags = fen.split(" ")[1].substr(4); //skip first 4 digits, for castle
- for (let c of ['w','b'])
- {
- for (let i=0; i<8; i++)
- flags[1][c][i] = (fenFlags.charAt((c=='w'?0:8)+i) == '1');
- }
- return flags;
+ return ChessRules.PIECES.concat(['s','t','u','c','o']);
}
- canTake([x1,y1], [x2,y2])
+ static IsGoodFlags(flags)
{
- 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);
+ // 4 for castle + 16 for pawns
+ return !!flags.match(/^[01]{20,20}$/);
}
- addCaptures([sx,sy], [ex,ey], moves)
+ setFlags(fenflags)
{
- const piece = this.getPiece(sx,sy);
- if (piece != VariantRules.KING)
+ 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'])
{
- moves.push(this.getBasicMove([sx,sy], [ex,ey], {c:'c',p:piece}));
- const takePiece = this.getPiece(ex,ey);
- if (takePiece != piece)
- moves.push(this.getBasicMove([sx,sy], [ex,ey], {c:'c',p:takePiece}));
+ for (let i=0; i<8; i++)
+ this.pawnFlags[c][i] = (flags.charAt((c=='w'?0:8)+i) == '1');
}
- else
- moves.push(this.getBasicMove([sx,sy], [ex,ey]));
}
- // Generic method to find possible moves of non-pawn pieces ("sliding or jumping")
- getSlideNJumpMoves([x,y], steps, oneStep)
+ aggregateFlags()
{
- const color = this.getColor(x,y);
- let moves = [];
- const [sizeX,sizeY] = VariantRules.size;
- outerLoop:
- for (var loop=0; loop<steps.length; loop++)
- {
- let step = steps[loop];
- let i = x + step[0];
- let j = y + step[1];
- while (i>=0 && i<sizeX && j>=0 && j<sizeY && this.board[i][j] == VariantRules.EMPTY)
- {
- moves.push(this.getBasicMove([x,y], [i,j])); //no capture
- if (oneStep !== undefined)
- continue outerLoop;
- i += step[0];
- j += step[1];
- }
- if (i>=0 && i<8 && j>=0 && j<8 && this.canTake([x,y], [i,j]))
- this.addCaptures([x,y], [i,j], moves);
- }
- return moves;
+ return [this.castleFlags, this.pawnFlags];
}
- // What are the pawn moves from square x,y considering color "color" ?
- getPotentialPawnMoves([x,y])
+ disaggregateFlags(flags)
{
- const color = this.getColor(x,y);
- var moves = [];
- var V = VariantRules;
- let [sizeX,sizeY] = VariantRules.size;
- const c = (color == 'c' ? this.turn : color);
- const shift = (c == "w" ? -1 : 1);
- let startRank = (c == "w" ? sizeY-2 : 1);
- let lastRank = (c == "w" ? 0 : sizeY-1);
-
- if (x+shift >= 0 && x+shift < sizeX && x+shift != lastRank)
- {
- // Normal moves
- if (this.board[x+shift][y] == V.EMPTY)
- {
- moves.push(this.getBasicMove([x,y], [x+shift,y]));
- if (x==startRank && this.board[x+2*shift][y] == V.EMPTY && this.flags[1][c][y])
- {
- // Two squares jump
- moves.push(this.getBasicMove([x,y], [x+2*shift,y]));
- }
- }
- // Captures
- if (y>0 && this.canTake([x,y], [x+shift,y-1]) && this.board[x+shift][y-1] != V.EMPTY)
- this.addCaptures([x,y], [x+shift,y-1], moves);
- if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1]) && this.board[x+shift][y+1] != V.EMPTY)
- this.addCaptures([x,y], [x+shift,y+1], moves);
- }
-
- if (x+shift == lastRank)
- {
- // Promotion
- let promotionPieces = [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN];
- 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:'c',p:p}));
- 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], {c:'c',p:p}));
- });
- }
-
- // En passant
- const Lep = this.epSquares.length;
- const epSquare = Lep>0 ? this.epSquares[Lep-1] : undefined;
- if (!!epSquare && epSquare.x == x+shift && Math.abs(epSquare.y - y) == 1)
- {
- let epStep = epSquare.y - y;
- var enpassantMove = this.getBasicMove([x,y], [x+shift,y+epStep]);
- enpassantMove.vanish.push({
- x: x,
- y: y+epStep,
- p: 'p',
- c: this.getColor(x,y+epStep)
- });
- enpassantMove.appear[0].c = 'c';
- moves.push(enpassantMove);
- }
-
- return moves;
+ this.castleFlags = flags[0];
+ this.pawnFlags = flags[1];
}
- getCastleMoves([x,y])
+ canTake([x1,y1], [x2,y2])
{
- const c = this.getColor(x,y);
- if (x != (c=="w" ? 7 : 0) || y != this.INIT_COL_KING[c])
- return []; //x isn't first rank, or king has moved (shortcut)
-
- const V = VariantRules;
+ 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);
+ }
- // Castling ?
- const oppCol = this.getOppCol(c);
+ // 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 = [];
- let i = 0;
- const finalSquares = [ [2,3], [6,5] ]; //king, then rook
- castlingCheck:
- for (let castleSide=0; castleSide < 2; castleSide++) //large, then small
- {
- if (!this.flags[0][c][castleSide])
- continue;
- // If this code is reached, rooks and king are on initial position
-
- // Nothing on the path of the king (and no checks; OK also if y==finalSquare)?
- let step = finalSquares[castleSide][0] < y ? -1 : 1;
- for (i=y; i!=finalSquares[castleSide][0]; i+=step)
+ standardMoves.forEach(m => {
+ if (m.vanish[0].p == V.PAWN)
{
- if (this.isAttacked([x,i], oppCol) || (this.board[x][i] != V.EMPTY &&
- // NOTE: next check is enough, because of chessboard constraints
- (this.getColor(x,i) != c || ![V.KING,V.ROOK].includes(this.getPiece(x,i)))))
+ 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')
{
- continue castlingCheck;
+ return; //checkered pawns cannot take en-passant
}
}
-
- // Nothing on the path to the rook?
- step = castleSide == 0 ? -1 : 1;
- for (i = y + step; i != this.INIT_COL_ROOK[c][castleSide]; i += step)
- {
- if (this.board[x][i] != V.EMPTY)
- continue castlingCheck;
- }
- const rookPos = this.INIT_COL_ROOK[c][castleSide];
-
- // Nothing on final squares, except maybe king and castling rook?
- for (i=0; i<2; i++)
+ if (m.vanish.length == 1)
+ moves.push(m); //no capture
+ else
{
- if (this.board[x][finalSquares[castleSide][i]] != V.EMPTY &&
- this.getPiece(x,finalSquares[castleSide][i]) != V.KING &&
- finalSquares[castleSide][i] != rookPos)
+ // 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))
{
- continue castlingCheck;
+ // Add transformation into captured piece
+ let m2 = JSON.parse(JSON.stringify(m));
+ m2.appear[0].p = m.vanish[1].p;
+ moves.push(m2);
}
}
-
- // If this code is reached, castle is valid
- moves.push( new Move({
- appear: [
- new PiPo({x:x,y:finalSquares[castleSide][0],p:V.KING,c:c}),
- new PiPo({x:x,y:finalSquares[castleSide][1],p:V.ROOK,c:c})],
- vanish: [
- new PiPo({x:x,y:y,p:V.KING,c:c}),
- new PiPo({x:x,y:rookPos,p:V.ROOK,c:c})],
- end: Math.abs(y - rookPos) <= 2
- ? {x:x, y:rookPos}
- : {x:x, y:y + 2 * (castleSide==0 ? -1 : 1)}
- }) );
- }
-
+ });
return moves;
}
canIplay(side, [x,y])
{
- return ((side=='w' && this.moves.length%2==0) || (side=='b' && this.moves.length%2==1))
- && [side,'c'].includes(this.getColor(x,y));
+ return (side == this.turn && [side,'c'].includes(this.getColor(x,y)));
}
// Does m2 un-do m1 ? (to disallow undoing checkered moves)
{
for (let i of [-1,1])
{
- if (y+i>=0 && y+i<8 && this.getPiece(x+pawnShift,y+i)==VariantRules.PAWN
+ if (y+i>=0 && y+i<8 && this.getPiece(x+pawnShift,y+i)==V.PAWN
&& this.getColor(x+pawnShift,y+i)==c)
{
return true;
{
this.play(move);
const color = this.turn;
- this.moves.push(move); //artifically change turn, for checkered pawns (TODO)
- const kingAttacked = this.isAttacked(this.kingPos[color], [this.getOppCol(color),'c']);
+ // Artifically change turn, for checkered pawns
+ this.turn = this.getOppCol(color);
+ const kingAttacked = this.isAttacked(
+ this.kingPos[color], [this.getOppCol(color),'c']);
let res = kingAttacked
- ? [ JSON.parse(JSON.stringify(this.kingPos[color])) ] //need to duplicate!
- : [ ];
- this.moves.pop();
+ ? [JSON.parse(JSON.stringify(this.kingPos[color]))] //need to duplicate!
+ : [];
+ this.turn = color;
this.undo(move);
return res;
}
updateVariables(move)
{
- const piece = this.getPiece(move.start.x,move.start.y);
- const c = this.getColor(move.start.x,move.start.y);
-
- if (c != 'c') //checkered not concerned by castle flags
- {
- const firstRank = (c == "w" ? 7 : 0);
- // Update king position + flags
- if (piece == VariantRules.KING && move.appear.length > 0)
- {
- this.kingPos[c][0] = move.appear[0].x;
- this.kingPos[c][1] = move.appear[0].y;
- this.flags[0][c] = [false,false];
- return;
- }
- const oppCol = this.getOppCol(c);
- const oppFirstRank = 7 - firstRank;
- if (move.start.x == firstRank //our rook moves?
- && this.INIT_COL_ROOK[c].includes(move.start.y))
- {
- const flagIdx = move.start.y == this.INIT_COL_ROOK[c][0] ? 0 : 1;
- this.flags[0][c][flagIdx] = false;
- }
- else if (move.end.x == oppFirstRank //we took opponent rook?
- && this.INIT_COL_ROOK[c].includes(move.end.y))
- {
- const flagIdx = move.end.y == this.INIT_COL_ROOK[oppCol][0] ? 0 : 1;
- this.flags[0][oppCol][flagIdx] = false;
- }
- }
-
- // Does it turn off a 2-squares pawn flag?
+ 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 == VariantRules.PAWN)
- this.flags[1][move.start.x==6 ? "w" : "b"][move.start.y] = false;
+ 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;
- if (!this.isAttacked(this.kingPos[color], this.getOppCol(color))
- && !this.isAttacked(this.kingPos[color], 'c'))
- {
- return "1/2";
- }
- // OK, checkmate
- return color == "w" ? "0-1" : "1-0";
+ // Artifically change turn, for checkered pawns
+ this.turn = this.getOppCol(this.turn);
+ const res = this.isAttacked(this.kingPos[color], [this.getOppCol(color),'c'])
+ ? (color == "w" ? "0-1" : "1-0")
+ : "1/2";
+ this.turn = this.getOppCol(this.turn);
+ return res;
}
evalPosition()
{
- const [sizeX,sizeY] = VariantRules.size;
let evaluation = 0;
//Just count material for now, considering checkered neutral (...)
- for (let i=0; i<sizeX; i++)
+ for (let i=0; i<V.size.x; i++)
{
- for (let j=0; j<sizeY; j++)
+ for (let j=0; j<V.size.y; j++)
{
- if (this.board[i][j] != VariantRules.EMPTY)
+ if (this.board[i][j] != V.EMPTY)
{
const sqColor = this.getColor(i,j);
const sign = sqColor == "w" ? 1 : (sqColor=="b" ? -1 : 0);
- evaluation += sign * VariantRules.VALUES[this.getPiece(i,j)];
+ evaluation += sign * V.VALUES[this.getPiece(i,j)];
}
}
}
static GenRandInitFen()
{
- return ChessRules.GenRandInitFen() + "1111111111111111"; //add 16 pawns flags
+ const randFen = ChessRules.GenRandInitFen();
+ // Add 16 pawns flags:
+ return randFen.replace(" w 1111", " w 11111111111111111111");
}
getFlagsFen()
{
- let fen = "";
- // Add castling flags
- for (let c of ['w','b'])
- {
- for (let i=0; i<2; i++)
- fen += this.flags[0][c][i] ? '1' : '0';
- }
+ let fen = super.getFlagsFen();
// Add pawns flags
for (let c of ['w','b'])
{
for (let i=0; i<8; i++)
- fen += this.flags[1][c][i] ? '1' : '0';
+ fen += this.pawnFlags[c][i] ? '1' : '0';
}
return fen;
}
}
// Translate final square
- let finalSquare =
- String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x);
+ const finalSquare = V.CoordsToSquare(move.end);
- let piece = this.getPiece(move.start.x, move.start.y);
- if (piece == VariantRules.PAWN)
+ const piece = this.getPiece(move.start.x, move.start.y);
+ if (piece == V.PAWN)
{
// Pawn move
let notation = "";
if (move.vanish.length > 1)
{
// Capture
- let startColumn = String.fromCharCode(97 + move.start.y);
- notation = startColumn + "x" + finalSquare + "=" + move.appear[0].p.toUpperCase();
+ const startColumn = V.GetColumn(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();
+ if (move.appear.length > 0 && piece != move.appear[0].p) //promotion
+ notation += "=" + move.appear[0].p.toUpperCase();
+ }
return notation;
}
}
}
}
+
+const VariantRules = CheckeredRules;