1 import { ChessRules
, PiPo
} from "@/base_rules";
3 export class MagneticRules
extends ChessRules
{
5 static get HasEnpassant() {
9 getPotentialMovesFrom([x
, y
]) {
10 let standardMoves
= super.getPotentialMovesFrom([x
, y
]);
12 standardMoves
.forEach(m
=> {
13 let newMove_s
= this.applyMagneticLaws(m
);
14 if (newMove_s
.length
== 1) moves
.push(newMove_s
[0]);
16 else moves
= moves
.concat(newMove_s
);
21 // Complete a move with magnetic actions
22 // TODO: job is done multiple times for (normal) promotions.
23 applyMagneticLaws(move) {
24 // Exception: kings are not charged
25 if (move.appear
[0].p
== V
.KING
&& move.appear
.length
== 1) return [move];
26 // If castling, rook is charged:
27 const aIdx
= move.appear
[0].p
!= V
.KING
? 0 : 1;
28 const [x
, y
] = [move.appear
[aIdx
].x
, move.appear
[aIdx
].y
];
29 const color
= this.turn
;
30 const lastRank
= color
== "w" ? 0 : 7;
31 const standardMove
= JSON
.parse(JSON
.stringify(move));
32 this.play(standardMove
);
39 let [i
, j
] = [x
+ step
[0], y
+ step
[1]];
40 while (V
.OnBoard(i
, j
)) {
41 if (this.board
[i
][j
] != V
.EMPTY
) {
42 // Found something. Same color or not?
43 if (this.getColor(i
, j
) != color
) {
46 (Math
.abs(i
- x
) >= 2 || Math
.abs(j
- y
) >= 2) &&
47 this.getPiece(i
, j
) != V
.KING
51 p: this.getPiece(i
, j
),
52 c: this.getColor(i
, j
),
59 p: this.getPiece(i
, j
),
60 c: this.getColor(i
, j
),
68 if (this.getPiece(i
, j
) != V
.KING
) {
69 // Push it until we meet an obstacle or edge of the board
70 let [ii
, jj
] = [i
+ step
[0], j
+ step
[1]];
71 while (V
.OnBoard(ii
, jj
)) {
72 if (this.board
[ii
][jj
] != V
.EMPTY
) break;
78 if (Math
.abs(ii
- i
) >= 1 || Math
.abs(jj
- j
) >= 1) {
81 p: this.getPiece(i
, j
),
82 c: this.getColor(i
, j
),
89 p: this.getPiece(i
, j
),
90 c: this.getColor(i
, j
),
104 this.undo(standardMove
);
106 // Scan move for pawn (max 1) on 8th rank
107 for (let i
= 1; i
< move.appear
.length
; i
++) {
109 move.appear
[i
].p
== V
.PAWN
&&
110 move.appear
[i
].c
== color
&&
111 move.appear
[i
].x
== lastRank
113 move.appear
[i
].p
= V
.ROOK
;
115 for (let piece
of [V
.KNIGHT
, V
.BISHOP
, V
.QUEEN
]) {
116 let cmove
= JSON
.parse(JSON
.stringify(move));
117 cmove
.appear
[i
].p
= piece
;
120 // Swap appear[i] and appear[0] for moves presentation
121 // (TODO: this is awkward)
123 let tmp
= m
.appear
[0];
124 m
.appear
[0] = m
.appear
[i
];
130 if (moves
.length
== 0)
131 //no pawn on 8th rank
137 if (this.kingPos
[this.turn
][0] < 0) return false;
138 return true; //TODO: is it right?
142 // There are no checks
151 super.postPlay(move);
152 const c
= move.vanish
[0].c
;
153 if (move.vanish
.length
>= 2 && move.vanish
[1].p
== V
.KING
) {
154 // We took opponent king !
155 const oppCol
= V
.GetOppCol(c
);
156 this.kingPos
[oppCol
] = [-1, -1];
157 this.castleFlags
[oppCol
] = [8, 8];
159 // Did we magnetically move our (init) rooks or opponents' ones ?
160 const firstRank
= c
== "w" ? 7 : 0;
161 const oppFirstRank
= 7 - firstRank
;
162 const oppCol
= V
.GetOppCol(c
);
163 move.vanish
.forEach(psq
=> {
165 psq
.x
== firstRank
&&
166 this.castleFlags
[c
].includes(psq
.y
)
168 this.castleFlags
[c
][psq
.y
== this.castleFlags
[c
][0] ? 0 : 1] = 8;
171 psq
.x
== oppFirstRank
&&
172 this.castleFlags
[oppCol
].includes(psq
.y
)
174 const flagIdx
= (psq
.y
== this.castleFlags
[oppCol
][0] ? 0 : 1);
175 this.castleFlags
[oppCol
][flagIdx
] = 8;
181 super.postUndo(move);
182 const c
= move.vanish
[0].c
;
183 const oppCol
= V
.GetOppCol(c
);
184 if (this.kingPos
[oppCol
][0] < 0) {
185 // Last move took opponent's king
186 for (let psq
of move.vanish
) {
188 this.kingPos
[oppCol
] = [psq
.x
, psq
.y
];
196 const color
= this.turn
;
197 const kp
= this.kingPos
[color
];
200 return color
== "w" ? "0-1" : "1-0";
201 if (this.atLeastOneMove())
204 return "1/2"; //no moves but kings still there
207 static get THRESHOLD_MATE() {
208 return 500; //checkmates evals may be slightly below 1000
211 static get SEARCH_DEPTH() {