1 class CheckeredRules
extends ChessRules
6 return b
[0]=='c' ? "Checkered/"+b : b
;
10 const checkered_codes
= {
18 return checkered_codes
[b
[1]];
19 return ChessRules
.board2fen(b
);
23 const checkered_pieces
= {
30 if (Object
.keys(checkered_pieces
).includes(f
))
31 return 'c'+checkered_pieces
[f
];
32 return ChessRules
.fen2board(f
);
37 super.setFlags(fen
); //castleFlags
40 "w": new Array(8), //pawns can move 2 squares?
43 const flags
= fen
.split(" ")[1].substr(4); //skip first 4 digits, for castle
44 for (let c
of ['w','b'])
46 for (let i
=0; i
<8; i
++)
47 this.pawnFlags
[c
][i
] = (flags
.charAt((c
=='w'?0:8)+i
) == '1');
51 // Aggregates flags into one object
53 return [this.castleFlags
, this.pawnFlags
];
59 this.castleFlags
= flags
[0];
60 this.pawnFlags
= flags
[1];
63 canTake([x1
,y1
], [x2
,y2
])
65 const color1
= this.getColor(x1
,y1
);
66 const color2
= this.getColor(x2
,y2
);
67 // Checkered aren't captured
68 return color1
!= color2
&& color2
!= 'c' && (color1
!= 'c' || color2
!= this.turn
);
71 // Post-processing: apply "checkerization" of standard moves
72 getPotentialMovesFrom([x
,y
])
74 let standardMoves
= super.getPotentialMovesFrom([x
,y
]);
75 if (this.getPiece(x
,y
) == VariantRules
.KING
)
76 return standardMoves
; //king has to be treated differently (for castles)
78 standardMoves
.forEach(m
=> {
79 if (m
.vanish
[0].p
== VariantRules
.PAWN
&& Math
.abs(m
.end
.x
-m
.start
.x
)==2
80 && !this.pawnFlags
[this.turn
][m
.start
.y
])
82 return; //skip forbidden 2-squares jumps
84 if (m
.vanish
.length
== 1)
85 moves
.push(m
); //no capture
88 // A capture occured (m.vanish.length == 2)
90 moves
.push(JSON
.parse(JSON
.stringify(m
)));
91 if (m
.appear
[0].p
!= m
.vanish
[1].p
)
93 // Add transformation into captured piece
94 let m2
= JSON
.parse(JSON
.stringify(m
));
95 m2
.vanish
[1].p
= m
.appear
[0].p
;
103 canIplay(side
, [x
,y
])
105 return ((side
=='w' && this.moves
.length
%2==0) || (side
=='b' && this.moves
.length
%2==1))
106 && [side
,'c'].includes(this.getColor(x
,y
));
109 // Does m2 un-do m1 ? (to disallow undoing checkered moves)
110 oppositeMoves(m1
, m2
)
112 return m1
.appear
.length
== 1 && m2
.appear
.length
== 1
113 && m1
.vanish
.length
== 1 && m2
.vanish
.length
== 1
114 && m1
.start
.x
== m2
.end
.x
&& m1
.end
.x
== m2
.start
.x
115 && m1
.start
.y
== m2
.end
.y
&& m1
.end
.y
== m2
.start
.y
116 && m1
.appear
[0].c
== m2
.vanish
[0].c
&& m1
.appear
[0].p
== m2
.vanish
[0].p
117 && m1
.vanish
[0].c
== m2
.appear
[0].c
&& m1
.vanish
[0].p
== m2
.appear
[0].p
;
122 if (moves
.length
== 0)
124 const color
= this.turn
;
125 return moves
.filter(m
=> {
126 const L
= this.moves
.length
;
127 if (L
> 0 && this.oppositeMoves(this.moves
[L
-1], m
))
129 return !this.underCheck(m
);
133 isAttackedByPawn([x
,y
], colors
)
135 for (let c
of colors
)
137 const color
= (c
=="c" ? this.turn : c
);
138 let pawnShift
= (color
=="w" ? 1 : -1);
139 if (x
+pawnShift
>=0 && x
+pawnShift
<8)
141 for (let i
of [-1,1])
143 if (y
+i
>=0 && y
+i
<8 && this.getPiece(x
+pawnShift
,y
+i
)==VariantRules
.PAWN
144 && this.getColor(x
+pawnShift
,y
+i
)==c
)
156 const color
= this.turn
;
158 let res
= this.isAttacked(this.kingPos
[color
], [this.getOppCol(color
),'c']);
163 getCheckSquares(move)
166 const color
= this.turn
;
167 this.moves
.push(move); //artifically change turn, for checkered pawns (TODO)
168 const kingAttacked
= this.isAttacked(this.kingPos
[color
], [this.getOppCol(color
),'c']);
169 let res
= kingAttacked
170 ? [ JSON
.parse(JSON
.stringify(this.kingPos
[color
])) ] //need to duplicate!
177 updateVariables(move)
179 const c
= this.getColor(move.start
.x
,move.start
.y
);
180 if (c
!= 'c') //checkered not concerned by castle flags
181 super.updateVariables(move);
183 // Does it turn off a 2-squares pawn flag?
184 const secondRank
= [1,6];
185 if (secondRank
.includes(move.start
.x
) && move.vanish
[0].p
== VariantRules
.PAWN
)
186 this.pawnFlags
[move.start
.x
==6 ? "w" : "b"][move.start
.y
] = false;
191 const color
= this.turn
;
192 if (!this.isAttacked(this.kingPos
[color
], this.getOppCol(color
))
193 && !this.isAttacked(this.kingPos
[color
], 'c'))
198 return color
== "w" ? "0-1" : "1-0";
203 const [sizeX
,sizeY
] = VariantRules
.size
;
205 //Just count material for now, considering checkered neutral (...)
206 for (let i
=0; i
<sizeX
; i
++)
208 for (let j
=0; j
<sizeY
; j
++)
210 if (this.board
[i
][j
] != VariantRules
.EMPTY
)
212 const sqColor
= this.getColor(i
,j
);
213 const sign
= sqColor
== "w" ? 1 : (sqColor
=="b" ? -1 : 0);
214 evaluation
+= sign
* VariantRules
.VALUES
[this.getPiece(i
,j
)];
221 static GenRandInitFen()
223 return ChessRules
.GenRandInitFen() + "1111111111111111"; //add 16 pawns flags
228 let fen
= super.getFlagsFen();
230 for (let c
of ['w','b'])
232 for (let i
=0; i
<8; i
++)
233 fen
+= this.pawnFlags
[c
][i
] ? '1' : '0';
240 if (move.appear
.length
== 2)
243 if (move.end
.y
< move.start
.y
)
249 // Translate final square
251 String
.fromCharCode(97 + move.end
.y
) + (VariantRules
.size
[0]-move.end
.x
);
253 let piece
= this.getPiece(move.start
.x
, move.start
.y
);
254 if (piece
== VariantRules
.PAWN
)
258 if (move.vanish
.length
> 1)
261 let startColumn
= String
.fromCharCode(97 + move.start
.y
);
262 notation
= startColumn
+ "x" + finalSquare
+ "=" + move.appear
[0].p
.toUpperCase();
265 notation
= finalSquare
;
266 if (move.appear
.length
> 0 && piece
!= move.appear
[0].p
) //promotion
267 notation
+= "=" + move.appear
[0].p
.toUpperCase();
274 return piece
.toUpperCase() + (move.vanish
.length
> 1 ? "x" : "") + finalSquare
275 + (move.vanish
.length
> 1 ? "=" + move.appear
[0].p
.toUpperCase() : "");