1 import { ChessRules
, PiPo
, Move
} from "@/base_rules";
3 export const VariantRules
= class AllmateRules
extends ChessRules
{
4 static get HasEnpassant() {
9 return false; //Captures handled differently
17 static GenRandInitFen() {
18 return ChessRules
.GenRandInitFen().replace(/ -$/, "");
21 getPotentialMovesFrom([x
, y
]) {
22 let moves
= super.getPotentialMovesFrom([x
, y
]);
24 // Augment moves with "mate-captures":
25 // TODO: this is coded in a highly inefficient way...
26 const color
= this.turn
;
27 const oppCol
= V
.GetOppCol(this.turn
);
31 // 1) What is attacked?
33 for (let i
=0; i
<V
.size
.x
; i
++) {
34 for (let j
=0; j
<V
.size
.y
; j
++) {
35 if (this.getColor(i
,j
) == oppCol
&& this.isAttacked([i
,j
], [color
]))
36 attacked
[i
+"_"+j
] = [i
,j
];
40 // 2) Among attacked pieces, which cannot escape capture?
41 // Avoid "oppMoves = this.getAllValidMoves();" => infinite recursion
42 outerLoop: for (let i
=0; i
<V
.size
.x
; i
++) {
43 for (let j
=0; j
<V
.size
.y
; j
++) {
44 if (this.getColor(i
,j
) == oppCol
) {
46 switch (this.getPiece(i
, j
)) {
48 oppMoves
= this.getPotentialPawnMoves([i
, j
]);
51 oppMoves
= this.getPotentialRookMoves([i
, j
]);
54 oppMoves
= this.getPotentialKnightMoves([i
, j
]);
57 oppMoves
= this.getPotentialBishopMoves([i
, j
]);
60 oppMoves
= this.getPotentialQueenMoves([i
, j
]);
63 oppMoves
= this.getPotentialKingMoves([i
, j
]);
66 for (let om
of oppMoves
) {
67 V
.PlayOnBoard(this.board
, om
);
68 Object
.values(attacked
).forEach(sq
=> {
69 const origSq
= [sq
[0], sq
[1]];
70 if (om
.start
.x
== sq
[0] && om
.start
.y
== sq
[1])
72 sq
= [om
.appear
[0].x
, om
.appear
[0].y
];
73 if (!this.isAttacked(sq
, [color
]))
74 delete attacked
[origSq
[0]+"_"+origSq
[1]];
76 V
.UndoOnBoard(this.board
, om
);
77 if (Object
.keys(attacked
).length
== 0)
78 // No need to explore more moves
85 // 3) Add mate-captures:
86 Object
.values(attacked
).forEach(sq
=> {
87 m
.vanish
.push(new PiPo({
91 p: this.getPiece(sq
[0], sq
[1])
101 // No "under check" conditions in castling
102 getCastleMoves([x
, y
]) {
103 const c
= this.getColor(x
, y
);
104 if (x
!= (c
== "w" ? V
.size
.x
- 1 : 0) || y
!= this.INIT_COL_KING
[c
])
105 return []; //x isn't first rank, or king has moved (shortcut)
108 const oppCol
= V
.GetOppCol(c
);
112 const finalSquares
= [
114 [V
.size
.y
- 2, V
.size
.y
- 3]
119 castleSide
++ //large, then small
121 if (!this.castleFlags
[c
][castleSide
]) continue;
122 // If this code is reached, rooks and king are on initial position
124 // Nothing on the path of the king ? (and no checks)
125 const finDist
= finalSquares
[castleSide
][0] - y
;
126 let step
= finDist
/ Math
.max(1, Math
.abs(finDist
));
127 for (let i
= y
; i
!= finalSquares
[castleSide
][0]; i
+= step
) {
129 this.board
[x
][i
] != V
.EMPTY
&&
130 // NOTE: next check is enough, because of chessboard constraints
131 (this.getColor(x
, i
) != c
||
132 ![V
.KING
, V
.ROOK
].includes(this.getPiece(x
, i
)))
134 continue castlingCheck
;
138 // Nothing on the path to the rook?
139 step
= castleSide
== 0 ? -1 : 1;
140 for (i
= y
+ step
; i
!= this.INIT_COL_ROOK
[c
][castleSide
]; i
+= step
) {
141 if (this.board
[x
][i
] != V
.EMPTY
) continue castlingCheck
;
143 const rookPos
= this.INIT_COL_ROOK
[c
][castleSide
];
145 // Nothing on final squares, except maybe king and castling rook?
146 for (i
= 0; i
< 2; i
++) {
148 this.board
[x
][finalSquares
[castleSide
][i
]] != V
.EMPTY
&&
149 this.getPiece(x
, finalSquares
[castleSide
][i
]) != V
.KING
&&
150 finalSquares
[castleSide
][i
] != rookPos
152 continue castlingCheck
;
156 // If this code is reached, castle is valid
160 new PiPo({ x: x
, y: finalSquares
[castleSide
][0], p: V
.KING
, c: c
}),
161 new PiPo({ x: x
, y: finalSquares
[castleSide
][1], p: V
.ROOK
, c: c
})
164 new PiPo({ x: x
, y: y
, p: V
.KING
, c: c
}),
165 new PiPo({ x: x
, y: rookPos
, p: V
.ROOK
, c: c
})
168 Math
.abs(y
- rookPos
) <= 2
169 ? { x: x
, y: rookPos
}
170 : { x: x
, y: y
+ 2 * (castleSide
== 0 ? -1 : 1) }
178 // TODO: allow pieces to "commit suicide"? (Currently yes except king)
180 // Remove moves which let the king mate-captured:
181 if (moves
.length
== 0) return [];
182 const color
= this.turn
;
183 const oppCol
= V
.GetOppCol(color
);
184 return moves
.filter(m
=> {
187 if (this.underCheck(color
)) {
189 const attacked
= this.kingPos
[color
];
190 // Try to find a move to escape check
191 // TODO: very inefficient method.
192 outerLoop: for (let i
=0; i
<V
.size
.x
; i
++) {
193 for (let j
=0; j
<V
.size
.y
; j
++) {
194 if (this.getColor(i
,j
) == color
) {
196 // Artficial turn change to "play twice":
198 switch (this.getPiece(i
, j
)) {
200 emoves
= this.getPotentialPawnMoves([i
, j
]);
203 emoves
= this.getPotentialRookMoves([i
, j
]);
206 emoves
= this.getPotentialKnightMoves([i
, j
]);
209 emoves
= this.getPotentialBishopMoves([i
, j
]);
212 emoves
= this.getPotentialQueenMoves([i
, j
]);
215 emoves
= this.getPotentialKingMoves([i
, j
]);
219 for (let em
of emoves
) {
220 V
.PlayOnBoard(this.board
, em
);
222 if (em
.start
.x
== attacked
[0] && em
.start
.y
== attacked
[1])
224 sq
= [em
.appear
[0].x
, em
.appear
[0].y
];
225 if (!this.isAttacked(sq
, [oppCol
]))
227 V
.UndoOnBoard(this.board
, em
);
229 // No need to explore more moves
241 updateVariables(move) {
242 super.updateVariables(move);
243 const color
= V
.GetOppCol(this.turn
);
244 if (move.vanish
.length
>= 2 && move.appear
.length
== 1) {
245 move.vanish
.forEach(v
=> {
248 // Did opponent king disappeared?
250 this.kingPos
[this.turn
] = [-1, -1];
252 else if (v
.p
== V
.ROOK
) {
253 if (v
.y
< this.INIT_COL_KING
[v
.c
])
254 this.castleFlags
[v
.c
][0] = false;
256 // v.y > this.INIT_COL_KING[v.c]
257 this.castleFlags
[v
.c
][1] = false;
263 unupdateVariables(move) {
264 super.unupdateVariables(move);
265 const color
= this.turn
;
266 if (move.vanish
.length
>= 2 && move.appear
.length
== 1) {
267 // Did opponent king disappeared?
268 const psq
= move.vanish
.find(v
=> v
.p
== V
.KING
&& v
.c
!= color
)
270 this.kingPos
[psq
.c
] = [psq
.x
, psq
.y
];
275 const color
= this.turn
;
276 const kp
= this.kingPos
[color
];
279 return color
== "w" ? "0-1" : "1-0";
280 if (this.atLeastOneMove())
282 // Kings still there, no moves:
286 static get SEARCH_DEPTH() {
291 let notation
= super.getNotation(move);
292 // Add a capture mark (not describing what is captured...):
293 if (move.vanish
.length
> 1 && move.appear
[0].p
!= V
.KING
) {
294 if (notation
.match(/^[a-h]/))
295 // Pawn capture: remove "bx" in bxc4 for example
296 notation
= notation
.substr(2);
298 notation
= notation
.replace("x","") + "X";