1 class UltimaRules
extends ChessRules
5 if (b
[1] == "m") //'m' for Immobilizer (I is too similar to 1)
7 return b
; //usual piece
12 this.kingPos
= {'w':[-1,-1], 'b':[-1,-1]};
13 const fenParts
= fen
.split(" ");
14 const position
= fenParts
[0].split("/");
15 for (let i
=0; i
<position
.length
; i
++)
18 for (let j
=0; j
<position
[i
].length
; j
++)
20 switch (position
[i
].charAt(j
))
23 this.kingPos
['b'] = [i
,k
];
26 this.kingPos
['w'] = [i
,k
];
29 let num
= parseInt(position
[i
].charAt(j
));
36 this.epSquares
= []; //no en-passant here
41 // TODO: for compatibility?
42 this.castleFlags
= {"w":[false,false], "b":[false,false]};
45 static get IMMOBILIZER() { return 'm'; }
46 // Although other pieces keep their names here for coding simplicity,
48 // - a "rook" is a coordinator, capturing by coordinating with the king
49 // - a "knight" is a long-leaper, capturing as in draughts
50 // - a "bishop" is a chameleon, capturing as its prey
51 // - a "queen" is a withdrawer, capturing by moving away from pieces
53 getPotentialMovesFrom([x
,y
])
55 // Pre-check: is thing on this square immobilized?
56 // In this case add potential suicide as a move "taking the immobilizer"
57 const piece
= this.getPiece(x
,y
);
58 const color
= this.getColor(x
,y
);
59 const oppCol
= this.getOppCol(color
);
60 const V
= VariantRules
;
61 const adjacentSteps
= V
.steps
[V
.ROOK
].concat(V
.steps
[V
.BISHOP
]);
62 const [sizeX
,sizeY
] = V
.size
;
63 for (let step
of adjacentSteps
)
65 const [i
,j
] = [x
+step
[0],y
+step
[1]];
66 if (i
>=0 && i
<sizeX
&& j
>=0 && j
<sizeY
&& this.board
[i
][j
] != V
.EMPTY
67 && this.getColor(i
,j
) == oppCol
)
69 const oppPiece
= this.getPiece(i
,j
);
70 if (oppPiece
== V
.IMMOBILIZER
71 || (oppPiece
== V
.BISHOP
&& piece
== V
.IMMOBILIZER
))
75 vanish: [new PiPo({x:x
,y:y
,p:piece
,c:color
})],
82 switch (this.getPiece(x
,y
))
84 case VariantRules
.IMMOBILIZER:
85 return this.getPotentialImmobilizerMoves([x
,y
]);
87 return super.getPotentialMovesFrom([x
,y
]);
91 getSlideNJumpMoves([x
,y
], steps
, oneStep
)
93 const color
= this.getColor(x
,y
);
94 const piece
= this.getPiece(x
,y
);
96 const [sizeX
,sizeY
] = VariantRules
.size
;
98 for (let step
of steps
)
102 while (i
>=0 && i
<sizeX
&& j
>=0 && j
<sizeY
103 && this.board
[i
][j
] == VariantRules
.EMPTY
)
105 moves
.push(this.getBasicMove([x
,y
], [i
,j
]));
106 if (oneStep
!== undefined)
111 // Only king can take on occupied square:
112 if (piece
==VariantRules
.KING
&& i
>=0 && i
<sizeX
&& j
>=0
113 && j
<sizeY
&& this.canTake([x
,y
], [i
,j
]))
115 moves
.push(this.getBasicMove([x
,y
], [i
,j
]));
121 // Modify capturing moves among listed pawn moves
122 addPawnCaptures(moves
, byChameleon
)
124 const steps
= VariantRules
.steps
[VariantRules
.ROOK
];
125 const [sizeX
,sizeY
] = VariantRules
.size
;
126 const color
= this.turn
;
127 const oppCol
= this.getOppCol(color
);
129 if (!!byChameleon
&& m
.start
.x
!=m
.end
.x
&& m
.start
.y
!=m
.end
.y
)
130 return; //chameleon not moving as pawn
131 // Try capturing in every direction
132 for (let step
of steps
)
134 const sq2
= [m
.end
.x
+2*step
[0],m
.end
.y
+2*step
[1]];
135 if (sq2
[0]>=0 && sq2
[0]<sizeX
&& sq2
[1]>=0 && sq2
[1]<sizeY
136 && this.board
[sq2
[0]][sq2
[1]] != VariantRules
.EMPTY
137 && this.getColor(sq2
[0],sq2
[1]) == color
)
140 const sq1
= [m
.end
.x
+step
[0],m
.end
.y
+step
[1]];
141 if (this.board
[sq1
[0]][sq1
[1]] != VariantRules
.EMPTY
142 && this.getColor(sq1
[0],sq1
[1]) == oppCol
)
144 const piece1
= this.getPiece(sq1
[0],sq1
[1]);
145 if (!byChameleon
|| piece1
== VariantRules
.PAWN
)
147 m
.vanish
.push(new PiPo({
161 getPotentialPawnMoves([x
,y
])
163 let moves
= super.getPotentialRookMoves([x
,y
]);
164 this.addPawnCaptures(moves
);
168 addRookCaptures(moves
, byChameleon
)
170 const color
= this.turn
;
171 const oppCol
= this.getOppCol(color
);
172 const kp
= this.kingPos
[color
];
174 // Check piece-king rectangle (if any) corners for enemy pieces
175 if (m
.end
.x
== kp
[0] || m
.end
.y
== kp
[1])
176 return; //"flat rectangle"
177 const corner1
= [Math
.max(m
.end
.x
,kp
[0]), Math
.min(m
.end
.y
,kp
[1])];
178 const corner2
= [Math
.min(m
.end
.x
,kp
[0]), Math
.max(m
.end
.y
,kp
[1])];
179 for (let [i
,j
] of [corner1
,corner2
])
181 if (this.board
[i
][j
] != VariantRules
.EMPTY
&& this.getColor(i
,j
) == oppCol
)
183 const piece
= this.getPiece(i
,j
);
184 if (!byChameleon
|| piece
== VariantRules
.ROOK
)
186 m
.vanish
.push( new PiPo({
199 getPotentialRookMoves(sq
)
201 let moves
= super.getPotentialQueenMoves(sq
);
202 this.addRookCaptures(moves
);
207 getKnightCaptures(startSquare
, byChameleon
)
209 // Look in every direction for captures
210 const V
= VariantRules
;
211 const steps
= V
.steps
[V
.ROOK
].concat(V
.steps
[V
.BISHOP
]);
212 const [sizeX
,sizeY
] = V
.size
;
213 const color
= this.turn
;
214 const oppCol
= this.getOppCol(color
);
216 const [x
,y
] = [startSquare
[0],startSquare
[1]];
217 const piece
= this.getPiece(x
,y
); //might be a chameleon!
219 for (let step
of steps
)
221 let [i
,j
] = [x
+step
[0], y
+step
[1]];
222 while (i
>=0 && i
<sizeX
&& j
>=0 && j
<sizeY
&& this.board
[i
][j
]==V
.EMPTY
)
227 if (i
<0 || i
>=sizeX
|| j
<0 || j
>=sizeY
|| this.getColor(i
,j
)==color
228 || (!!byChameleon
&& this.getPiece(i
,j
)!=V
.KNIGHT
))
232 // last(thing), cur(thing) : stop if "cur" is our color, or beyond board limits,
233 // or if "last" isn't empty and cur neither. Otherwise, if cur is empty then
234 // add move until cur square; if cur is occupied then stop if !!byChameleon and
235 // the square not occupied by a leaper.
237 let cur
= [i
+step
[0],j
+step
[1]];
238 let vanished
= [ new PiPo({x:x
,y:y
,c:color
,p:piece
}) ];
239 while (cur
[0]>=0 && cur
[0]<sizeX
&& cur
[1]>=0 && cur
[1]<sizeY
)
241 if (this.board
[last
[0]][last
[1]] != V
.EMPTY
)
243 const oppPiece
= this.getPiece(last
[0],last
[1]);
244 if (!!byChameleon
&& oppPiece
!= V
.KNIGHT
)
247 vanished
.push( new PiPo({x:last
[0],y:last
[1],c:oppCol
,p:oppPiece
}) );
249 if (this.board
[cur
[0]][cur
[1]] != V
.EMPTY
)
251 if (this.getColor(cur
[0],cur
[1]) == color
252 || this.board
[last
[0]][last
[1]] != V
.EMPTY
) //TODO: redundant test
259 moves
.push(new Move({
260 appear: [ new PiPo({x:cur
[0],y:cur
[1],c:color
,p:piece
}) ],
261 vanish: JSON
.parse(JSON
.stringify(vanished
)), //TODO: required?
263 end: {x:cur
[0],y:cur
[1]}
266 last
= [last
[0]+step
[0],last
[1]+step
[1]];
267 cur
= [cur
[0]+step
[0],cur
[1]+step
[1]];
274 getPotentialKnightMoves(sq
)
276 return super.getPotentialQueenMoves(sq
).concat(this.getKnightCaptures(sq
));
279 getPotentialBishopMoves([x
,y
])
281 let moves
= super.getPotentialQueenMoves([x
,y
])
282 .concat(this.getKnightCaptures([x
,y
],"asChameleon"));
283 this.addPawnCaptures(moves
, "asChameleon");
284 this.addRookCaptures(moves
, "asChameleon");
285 this.addQueenCaptures(moves
, "asChameleon");
286 // Add king capture if it's within range
287 const oppKp
= this.kingPos
[this.getOppCol(this.turn
)];
288 if (Math
.abs(x
-oppKp
[0]) <= 1 && Math
.abs(y
-oppKp
[1]) <= 1)
289 moves
.push(this.getBasicMove([x
,y
],oppKp
));
290 // Post-processing: merge similar moves, concatenating vanish arrays
291 let mergedMoves
= {};
292 const [sizeX
,sizeY
] = VariantRules
.size
;
294 const key
= m
.end
.x
+ sizeX
* m
.end
.y
;
295 if (!mergedMoves
[key
])
296 mergedMoves
[key
] = m
;
299 for (let i
=1; i
<m
.vanish
.length
; i
++)
300 mergedMoves
[key
].vanish
.push(m
.vanish
[i
]);
303 // Finally return an array
305 Object
.keys(mergedMoves
).forEach(k
=> { moves
.push(mergedMoves
[k
]); });
310 addQueenCaptures(moves
, byChameleon
)
312 if (moves
.length
== 0)
314 const [x
,y
] = [moves
[0].start
.x
,moves
[0].start
.y
];
315 const V
= VariantRules
;
316 const adjacentSteps
= V
.steps
[V
.ROOK
].concat(V
.steps
[V
.BISHOP
]);
317 let capturingDirections
= [];
318 const color
= this.turn
;
319 const oppCol
= this.getOppCol(color
);
320 const [sizeX
,sizeY
] = V
.size
;
321 adjacentSteps
.forEach(step
=> {
322 const [i
,j
] = [x
+step
[0],y
+step
[1]];
323 if (i
>=0 && i
<sizeX
&& j
>=0 && j
<sizeY
324 && this.board
[i
][j
] != V
.EMPTY
&& this.getColor(i
,j
) == oppCol
325 && (!byChameleon
|| this.getPiece(i
,j
) == V
.QUEEN
))
327 capturingDirections
.push(step
);
332 m
.end
.x
!=x
? (m
.end
.x
-x
)/Math
.abs(m
.end
.x
-x
) : 0,
333 m
.end
.y
!=y
? (m
.end
.y
-y
)/Math
.abs(m
.end
.y
-y
) : 0
335 // NOTE: includes() and even _.isEqual() functions fail...
336 // TODO: this test should be done only once per direction
337 if (capturingDirections
.some(dir
=>
338 { return (dir
[0]==-step
[0] && dir
[1]==-step
[1]); }))
340 const [i
,j
] = [x
-step
[0],y
-step
[1]];
341 m
.vanish
.push(new PiPo({
344 p:this.getPiece(i
,j
),
351 getPotentialQueenMoves(sq
)
353 let moves
= super.getPotentialQueenMoves(sq
);
354 this.addQueenCaptures(moves
);
358 getPotentialImmobilizerMoves(sq
)
360 // Immobilizer doesn't capture
361 return super.getPotentialQueenMoves(sq
);
364 getPotentialKingMoves(sq
)
366 const V
= VariantRules
;
367 return this.getSlideNJumpMoves(sq
,
368 V
.steps
[V
.ROOK
].concat(V
.steps
[V
.BISHOP
]), "oneStep");
371 // TODO: verify this assertion
374 return true; //always at least one possible move
379 return false; //there is no check
382 getCheckSquares(move)
384 const c
= this.getOppCol(this.turn
); //opponent
385 const saveKingPos
= this.kingPos
[c
]; //king might be taken
387 // The only way to be "under check" is to have lost the king (thus game over)
388 let res
= this.kingPos
[c
][0] < 0
389 ? [ JSON
.parse(JSON
.stringify(saveKingPos
)) ]
395 updateVariables(move)
397 // Just update king(s) position(s)
398 const piece
= this.getPiece(move.start
.x
,move.start
.y
);
399 const c
= this.getColor(move.start
.x
,move.start
.y
);
400 if (piece
== VariantRules
.KING
&& move.appear
.length
> 0)
402 this.kingPos
[c
][0] = move.appear
[0].x
;
403 this.kingPos
[c
][1] = move.appear
[0].y
;
405 // Does this move takes opponent's king?
406 const oppCol
= this.getOppCol(c
);
407 for (let psq
of move.vanish
)
409 if (psq
.p
== VariantRules
.KING
)
411 this.kingPos
[oppCol
] = [-1,-1];
417 unupdateVariables(move)
419 super.unupdateVariables(move);
420 const c
= this.getColor(move.start
.x
,move.start
.y
);
421 const oppCol
= this.getOppCol(c
);
422 if (this.kingPos
[oppCol
][0] < 0)
424 // Last move took opponent's king
425 for (let psq
of move.vanish
)
429 this.kingPos
[oppCol
] = [psq
.x
, psq
.y
];
438 if (this.checkRepetition())
441 const color
= this.turn
;
442 // TODO: do we need "atLeastOneMove()"?
443 if (this.atLeastOneMove() && this.kingPos
[color
][0] >= 0)
446 return this.checkGameEnd();
451 // No valid move: our king disappeared
452 return this.turn
== "w" ? "0-1" : "1-0";
455 static get VALUES() { //TODO: totally experimental!
467 static get SEARCH_DEPTH() { return 2; } //TODO?
469 static get THRESHOLD_MATE() {
470 return 500; //checkmates evals may be slightly below 1000
473 static GenRandInitFen()
475 let pieces
= { "w": new Array(8), "b": new Array(8) };
476 // Shuffle pieces on first and last rank
477 for (let c
of ["w","b"])
479 let positions
= _
.range(8);
480 // Get random squares for every piece, totally freely
482 let randIndex
= _
.random(7);
483 const bishop1Pos
= positions
[randIndex
];
484 positions
.splice(randIndex
, 1);
486 randIndex
= _
.random(6);
487 const bishop2Pos
= positions
[randIndex
];
488 positions
.splice(randIndex
, 1);
490 randIndex
= _
.random(5);
491 const knight1Pos
= positions
[randIndex
];
492 positions
.splice(randIndex
, 1);
494 randIndex
= _
.random(4);
495 const knight2Pos
= positions
[randIndex
];
496 positions
.splice(randIndex
, 1);
498 randIndex
= _
.random(3);
499 const queenPos
= positions
[randIndex
];
500 positions
.splice(randIndex
, 1);
502 randIndex
= _
.random(2);
503 const kingPos
= positions
[randIndex
];
504 positions
.splice(randIndex
, 1);
506 randIndex
= _
.random(1);
507 const rookPos
= positions
[randIndex
];
508 positions
.splice(randIndex
, 1);
509 const immobilizerPos
= positions
[0];
511 pieces
[c
][bishop1Pos
] = 'b';
512 pieces
[c
][bishop2Pos
] = 'b';
513 pieces
[c
][knight1Pos
] = 'n';
514 pieces
[c
][knight2Pos
] = 'n';
515 pieces
[c
][queenPos
] = 'q';
516 pieces
[c
][kingPos
] = 'k';
517 pieces
[c
][rookPos
] = 'r';
518 pieces
[c
][immobilizerPos
] = 'm';
520 return pieces
["b"].join("") +
521 "/pppppppp/8/8/8/8/PPPPPPPP/" +
522 pieces
["w"].join("").toUpperCase() +
523 " 0000"; //TODO: flags?!
528 return "0000"; //TODO: or "-" ?
533 if (move.appear
.length
== 0)
536 String
.fromCharCode(97 + move.start
.y
) + (VariantRules
.size
[0]-move.start
.x
);
537 return "^" + startSquare
; //suicide
539 return super.getNotation(move);