class CheckeredRules extends ChessRules
{
- // Path to pieces
static getPpath(b)
{
return b[0]=='c' ? "Checkered/"+b : b;
return ChessRules.fen2board(f);
}
- initVariables(fen)
+ setFlags(fen)
{
- super.initVariables(fen);
- // Decode last non-capturing checkered move (if any)
- const cmove = fen.split(" ")[4];
- if (cmove != "-")
+ super.setFlags(fen); //castleFlags
+ this.pawnFlags =
{
- const piece = cmove.charAt(0);
- const startEnd = cmove.substr(1).split(";");
- const start = startEnd[0].split(",");
- const end = startEnd[1].split(",");
- this.moves.push(new Move({
- appear: [ new PiPo({c:"c", p:piece, x:end[0], y:end[1]}) ],
- vanish: [ new PiPo({c:"c", p:piece, x:start[0], y:start[1]}) ]
- }));
- }
- }
-
- static GetFlags(fen)
- {
- 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
+ "w": new Array(8), //pawns can move 2 squares?
+ "b": new Array(8)
+ };
+ const flags = 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');
+ this.pawnFlags[c][i] = (flags.charAt((c=='w'?0:8)+i) == '1');
}
- return flags;
}
- // can color1 take color2?
- canTake(color1, color2)
- {
- // Checkered aren't captured
- return color1 != color2 && color2 != 'c' && (color1 != 'c' || color2 != this.turn);
- }
-
- // Build regular move(s) from its initial and destination squares; tr: transformation
- getBasicMove(sx, sy, ex, ey, tr)
- {
- if (this.board[ex][ey] == VariantRules.EMPTY)
- {
- // No capture, standard move construction
- return [super.getBasicMove(sx,sy,ex,ey,tr)];
- }
- let moves = []; //captures: generally 2 choices, unless 'tr' is specified or piece==king
- const startPiece = this.getPiece(sx,sy);
- const endPiece = this.getPiece(ex,ey);
- const startColor = this.getColor(sx,sy);
- const endColor = this.getColor(ex,ey);
- for (let piece of !!tr ? [tr] :
- (startPiece==VariantRules.KING ? VariantRules.KING : _.uniq([startPiece,endPiece])))
- {
- var mv = new Move({
- appear: [
- new PiPo({
- x: ex,
- y: ey,
- c: startPiece==VariantRules.KING ? startColor : 'c',
- p: piece
- })
- ],
- vanish: [
- new PiPo({
- x: sx,
- y: sy,
- c: startColor,
- p: startPiece
- }),
- new PiPo({
- x: ex,
- y: ey,
- c: endColor,
- p: endPiece
- })
- ]
- });
- moves.push(mv);
- }
- return moves;
+ // Aggregates flags into one object
+ get flags() {
+ return [this.castleFlags, this.pawnFlags];
}
- // Generic method to find possible moves of non-pawn pieces ("sliding or jumping")
- getSlideNJumpMoves(x, y, color, steps, oneStep)
+ // Reverse operation
+ parseFlags(flags)
{
- var moves = [];
- let [sizeX,sizeY] = VariantRules.size;
- outerLoop:
- for (var loop=0; loop<steps.length; loop++)
- {
- var step = steps[loop];
- var i = x + step[0];
- var 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)[0]); //no capture
- if (oneStep !== undefined)
- continue outerLoop;
- i += step[0];
- j += step[1];
- }
- if (i>=0 && i<8 && j>=0 && j<8 && this.canTake(color, this.getColor(i,j)))
- moves = moves.concat(this.getBasicMove(x, y, i, j));
- }
- return moves;
+ this.castleFlags = flags[0];
+ this.pawnFlags = flags[1];
}
- // What are the pawn moves from square x,y considering color "color" ?
- getPotentialPawnMoves(x, y, color)
+ canTake([x1,y1], [x2,y2])
{
- 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)[0]);
- 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)[0]);
- }
- }
- // Captures
- if (y>0 && this.canTake(this.getColor(x,y), this.getColor(x+shift,y-1))
- && this.board[x+shift][y-1] != V.EMPTY)
- {
- moves = moves.concat(this.getBasicMove(x, y, x+shift, y-1));
- }
- if (y<sizeY-1 && this.canTake(this.getColor(x,y), this.getColor(x+shift,y+1))
- && this.board[x+shift][y+1] != V.EMPTY)
- {
- moves = moves.concat(this.getBasicMove(x, y, x+shift, y+1));
- }
- }
-
- 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, p)[0]);
- // Captures
- if (y>0 && this.canTake(this.getColor(x,y), this.getColor(x+shift,y-1))
- && this.board[x+shift][y-1] != V.EMPTY)
- {
- moves = moves.concat(this.getBasicMove(x, y, x+shift, y-1, p));
- }
- if (y<sizeY-1 && this.canTake(this.getColor(x,y), this.getColor(x+shift,y+1))
- && this.board[x+shift][y+1] != V.EMPTY)
- {
- moves = moves.concat(this.getBasicMove(x, y, x+shift, y+1, 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)[0];
- 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;
+ 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);
}
- getCastleMoves(x,y,c)
+ // Post-processing: apply "checkerization" of standard moves
+ getPotentialMovesFrom([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;
-
- // Castling ?
- const oppCol = this.getOppCol(c);
+ let standardMoves = super.getPotentialMovesFrom([x,y]);
+ const lastRank = this.turn == "w" ? 0 : 7;
+ if (this.getPiece(x,y) == VariantRules.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 == VariantRules.PAWN && Math.abs(m.end.x-m.start.x)==2
+ && !this.pawnFlags[this.turn][m.start.y])
{
- 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)))))
- {
- continue castlingCheck;
- }
+ return; //skip forbidden 2-squares jumps
}
-
- // 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:
+ && (m.vanish[0].p != VariantRules.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(color, sq)
+ canIplay(side, [x,y])
{
- return ((color=='w' && this.movesCount%2==0) || color=='c'
- || (color=='b' && this.movesCount%2==1))
- && [color,'c'].includes(this.getColor(sq[0], sq[1]));
+ return ((side=='w' && this.moves.length%2==0) || (side=='b' && this.moves.length%2==1))
+ && [side,'c'].includes(this.getColor(x,y));
}
// Does m2 un-do m1 ? (to disallow undoing checkered moves)
{
return m1.appear.length == 1 && m2.appear.length == 1
&& m1.vanish.length == 1 && m2.vanish.length == 1
-// && _.isEqual(m1.appear[0], m2.vanish[0]) //fails in HH case
-// && _.isEqual(m1.vanish[0], m2.appear[0]);
&& m1.start.x == m2.end.x && m1.end.x == m2.start.x
&& m1.start.y == m2.end.y && m1.end.y == m2.start.y
&& m1.appear[0].c == m2.vanish[0].c && m1.appear[0].p == m2.vanish[0].p
{
if (moves.length == 0)
return [];
- let color = this.getColor( moves[0].start.x, moves[0].start.y );
+ const color = this.turn;
return moves.filter(m => {
const L = this.moves.length;
if (L > 0 && this.oppositeMoves(this.moves[L-1], m))
return false;
- return !this.underCheck(m, color);
+ return !this.underCheck(m);
});
}
- isAttackedByPawn([x,y], c)
- {
- const color = (c=="c" ? this.turn : c);
- let pawnShift = (color=="w" ? 1 : -1);
- if (x+pawnShift>=0 && x+pawnShift<8)
- {
- for (let i of [-1,1])
- {
- if (y+i>=0 && y+i<8 && this.getPiece(x+pawnShift,y+i)==VariantRules.PAWN
- && this.getColor(x+pawnShift,y+i)==c)
- {
- return true;
- }
- }
- }
- return false;
- }
+ isAttackedByPawn([x,y], colors)
+ {
+ for (let c of colors)
+ {
+ const color = (c=="c" ? this.turn : c);
+ let pawnShift = (color=="w" ? 1 : -1);
+ if (x+pawnShift>=0 && x+pawnShift<8)
+ {
+ for (let i of [-1,1])
+ {
+ if (y+i>=0 && y+i<8 && this.getPiece(x+pawnShift,y+i)==VariantRules.PAWN
+ && this.getColor(x+pawnShift,y+i)==c)
+ {
+ return true;
+ }
+ }
+ }
+ }
+ return false;
+ }
+
+ underCheck(move)
+ {
+ const color = this.turn;
+ this.play(move);
+ let res = this.isAttacked(this.kingPos[color], [this.getOppCol(color),'c']);
+ this.undo(move);
+ return res;
+ }
- underCheck(move, c)
+ getCheckSquares(move)
{
- const color = c == 'c' ? this.turn : c;
this.play(move);
- let res = this.isAttacked(this.kingPos[color], this.getOppCol(color))
- || this.isAttacked(this.kingPos[color], 'c'); //TODO: quite inefficient...
+ 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']);
+ let res = kingAttacked
+ ? [ JSON.parse(JSON.stringify(this.kingPos[color])) ] //need to duplicate!
+ : [ ];
+ this.moves.pop();
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;
- }
- }
+ super.updateVariables(move);
// Does it 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;
- }
-
- play(move, ingame)
- {
- super.play(move, ingame);
- if (!ingame)
- this.moves.push(move); //needed for turn indication for checkered pieces
+ this.pawnFlags[move.start.x==6 ? "w" : "b"][move.start.y] = false;
}
- undo(move)
- {
- super.undo(move);
- this.moves.pop();
- }
-
- checkGameEnd(color)
+ checkGameEnd()
{
+ const color = this.turn;
if (!this.isAttacked(this.kingPos[color], this.getOppCol(color))
&& !this.isAttacked(this.kingPos[color], 'c'))
{
static GenRandInitFen()
{
- let fen = ChessRules.GenRandInitFen();
- return fen.replace(/ - 0$/, "1111111111111111 - 0 -");
- }
-
- getFen()
- {
- let fen = super.getFen() + " ";
- const L = this.moves.length;
- if (L > 0 && this.moves[L-1].vanish.length==1 && this.moves[L-1].appear[0].c=="c")
- {
- // Ok, un-cancellable checkered move
- fen += this.moves[L-1].appear[0].p
- + this.moves[L-1].start.x + "," + this.moves[L-1].start.y + ";"
- + this.moves[L-1].end.x + "," + this.moves[L-1].end.y;
- }
- else fen += "-";
- return fen;
+ return ChessRules.GenRandInitFen() + "1111111111111111"; //add 16 pawns flags
}
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;
}