Add Fugue variant
[vchess.git] / client / src / variants / Checkered2.js
CommitLineData
68e19a44 1import { ChessRules, Move, PiPo } from "@/base_rules";
0c3fe8a6 2
af34341d 3export class Checkered2Rules extends ChessRules {
7e8a7ea1 4
6808d7a1 5 static board2fen(b) {
dac39588 6 const checkered_codes = {
6808d7a1
BA
7 p: "s",
8 q: "t",
9 r: "u",
10 b: "c",
11 n: "o"
dac39588 12 };
6808d7a1 13 if (b[0] == "c") return checkered_codes[b[1]];
dac39588
BA
14 return ChessRules.board2fen(b);
15 }
16
6808d7a1 17 static fen2board(f) {
dac39588
BA
18 // Tolerate upper-case versions of checkered pieces (why not?)
19 const checkered_pieces = {
6808d7a1
BA
20 s: "p",
21 S: "p",
22 t: "q",
23 T: "q",
24 u: "r",
25 U: "r",
26 c: "b",
27 C: "b",
28 o: "n",
29 O: "n"
dac39588
BA
30 };
31 if (Object.keys(checkered_pieces).includes(f))
6808d7a1 32 return "c" + checkered_pieces[f];
dac39588
BA
33 return ChessRules.fen2board(f);
34 }
35
6808d7a1
BA
36 static get PIECES() {
37 return ChessRules.PIECES.concat(["s", "t", "u", "c", "o"]);
dac39588 38 }
7931e479 39
241bf8f2 40 getPpath(b) {
d1be8046 41 return (b[0] == "c" ? "Checkered/" : "") + b;
241bf8f2
BA
42 }
43
6808d7a1 44 setOtherVariables(fen) {
03cff0f7
BA
45 super.setOtherVariables(fen);
46 // Local stack of non-capturing checkered moves:
47 this.cmoves = [];
3a2a7b5f 48 const cmove = V.ParseFen(fen).cmove;
6808d7a1
BA
49 if (cmove == "-") this.cmoves.push(null);
50 else {
03cff0f7 51 this.cmoves.push({
6808d7a1
BA
52 start: ChessRules.SquareToCoords(cmove.substr(0, 2)),
53 end: ChessRules.SquareToCoords(cmove.substr(2))
03cff0f7
BA
54 });
55 }
56 }
57
6808d7a1
BA
58 static IsGoodFen(fen) {
59 if (!ChessRules.IsGoodFen(fen)) return false;
03cff0f7 60 const fenParts = fen.split(" ");
6808d7a1 61 if (fenParts.length != 6) return false;
03cff0f7
BA
62 if (fenParts[5] != "-" && !fenParts[5].match(/^([a-h][1-8]){2}$/))
63 return false;
64 return true;
65 }
66
6808d7a1 67 static IsGoodFlags(flags) {
dac39588 68 // 4 for castle + 16 for pawns
3a2a7b5f 69 return !!flags.match(/^[a-z]{4,4}[01]{16,16}$/);
dac39588
BA
70 }
71
6808d7a1 72 setFlags(fenflags) {
dac39588 73 super.setFlags(fenflags); //castleFlags
6808d7a1 74 this.pawnFlags = {
305ede7e
BA
75 w: [...Array(8)], //pawns can move 2 squares?
76 b: [...Array(8)]
dac39588 77 };
3a2a7b5f 78 const flags = fenflags.substr(4); //skip first 4 letters, for castle
6808d7a1
BA
79 for (let c of ["w", "b"]) {
80 for (let i = 0; i < 8; i++)
81 this.pawnFlags[c][i] = flags.charAt((c == "w" ? 0 : 8) + i) == "1";
dac39588
BA
82 }
83 }
84
6808d7a1 85 aggregateFlags() {
dac39588
BA
86 return [this.castleFlags, this.pawnFlags];
87 }
88
6808d7a1 89 disaggregateFlags(flags) {
dac39588
BA
90 this.castleFlags = flags[0];
91 this.pawnFlags = flags[1];
92 }
1d184b4c 93
e727fe31 94 getEpSquare(moveOrSquare) {
bbf66837 95 if (typeof moveOrSquare !== "object" || moveOrSquare.appear[0].c != 'c')
e727fe31
BA
96 return super.getEpSquare(moveOrSquare);
97 // Checkered move: no en-passant
98 return undefined;
99 }
100
6808d7a1
BA
101 getCmove(move) {
102 if (move.appear[0].c == "c" && move.vanish.length == 1)
103 return { start: move.start, end: move.end };
03cff0f7
BA
104 return null;
105 }
106
6808d7a1
BA
107 canTake([x1, y1], [x2, y2]) {
108 const color1 = this.getColor(x1, y1);
109 const color2 = this.getColor(x2, y2);
dac39588 110 // Checkered aren't captured
6808d7a1
BA
111 return (
112 color1 != color2 &&
113 color2 != "c" &&
114 (color1 != "c" || color2 != this.turn)
115 );
dac39588
BA
116 }
117
118 // Post-processing: apply "checkerization" of standard moves
6808d7a1
BA
119 getPotentialMovesFrom([x, y]) {
120 let standardMoves = super.getPotentialMovesFrom([x, y]);
dac39588 121 const lastRank = this.turn == "w" ? 0 : 7;
32f6285e 122 // King is treated differently: it never turn checkered
71ef1664 123 if (this.getPiece(x, y) == V.KING) return standardMoves;
dac39588
BA
124 let moves = [];
125 standardMoves.forEach(m => {
6808d7a1
BA
126 if (m.vanish[0].p == V.PAWN) {
127 if (
128 Math.abs(m.end.x - m.start.x) == 2 &&
129 !this.pawnFlags[this.turn][m.start.y]
32f6285e 130 ) {
dac39588 131 return; //skip forbidden 2-squares jumps
32f6285e 132 }
6808d7a1
BA
133 if (
134 this.board[m.end.x][m.end.y] == V.EMPTY &&
135 m.vanish.length == 2 &&
136 this.getColor(m.start.x, m.start.y) == "c"
137 ) {
dac39588
BA
138 return; //checkered pawns cannot take en-passant
139 }
140 }
32f6285e
BA
141 if (m.vanish.length == 1)
142 // No capture
143 moves.push(m);
6808d7a1 144 else {
dac39588
BA
145 // A capture occured (m.vanish.length == 2)
146 m.appear[0].c = "c";
147 moves.push(m);
6808d7a1 148 if (
32f6285e
BA
149 // Avoid promotions (already treated):
150 m.appear[0].p != m.vanish[1].p &&
6808d7a1
BA
151 (m.vanish[0].p != V.PAWN || m.end.x != lastRank)
152 ) {
dac39588
BA
153 // Add transformation into captured piece
154 let m2 = JSON.parse(JSON.stringify(m));
155 m2.appear[0].p = m.vanish[1].p;
156 moves.push(m2);
157 }
158 }
159 });
160 return moves;
161 }
162
e727fe31 163 getPotentialPawnMoves([x, y]) {
32f6285e
BA
164 let moves = super.getPotentialPawnMoves([x, y]);
165 // Post-process: set right color for checkered moves
af34341d 166 if (this.getColor(x, y) == 'c') {
32f6285e
BA
167 moves.forEach(m => {
168 m.appear[0].c = 'c'; //may be done twice if capture
169 m.vanish[0].c = 'c';
e727fe31 170 });
af34341d 171 }
68e19a44
BA
172 return moves;
173 }
174
6808d7a1
BA
175 canIplay(side, [x, y]) {
176 return side == this.turn && [side, "c"].includes(this.getColor(x, y));
dac39588
BA
177 }
178
179 // Does m2 un-do m1 ? (to disallow undoing checkered moves)
6808d7a1
BA
180 oppositeMoves(m1, m2) {
181 return (
61656127 182 !!m1 &&
6808d7a1
BA
183 m2.appear[0].c == "c" &&
184 m2.appear.length == 1 &&
185 m2.vanish.length == 1 &&
186 m1.start.x == m2.end.x &&
187 m1.end.x == m2.start.x &&
188 m1.start.y == m2.end.y &&
189 m1.end.y == m2.start.y
190 );
dac39588
BA
191 }
192
6808d7a1
BA
193 filterValid(moves) {
194 if (moves.length == 0) return [];
dac39588 195 const color = this.turn;
241bf8f2 196 const L = this.cmoves.length; //at least 1: init from FEN
dac39588 197 return moves.filter(m => {
6808d7a1 198 if (this.oppositeMoves(this.cmoves[L - 1], m)) return false;
dac39588
BA
199 this.play(m);
200 const res = !this.underCheck(color);
201 this.undo(m);
202 return res;
203 });
204 }
205
d1be8046
BA
206 getAllValidMoves() {
207 const oppCol = V.GetOppCol(this.turn);
208 let potentialMoves = [];
209 for (let i = 0; i < V.size.x; i++) {
210 for (let j = 0; j < V.size.y; j++) {
af34341d 211 // NOTE: just testing == color isn't enough because of checkered pieces
d1be8046
BA
212 if (this.board[i][j] != V.EMPTY && this.getColor(i, j) != oppCol) {
213 Array.prototype.push.apply(
214 potentialMoves,
215 this.getPotentialMovesFrom([i, j])
216 );
217 }
218 }
219 }
220 return this.filterValid(potentialMoves);
221 }
222
223 atLeastOneMove() {
224 const oppCol = V.GetOppCol(this.turn);
225 for (let i = 0; i < V.size.x; i++) {
226 for (let j = 0; j < V.size.y; j++) {
b83a675a 227 // NOTE: just testing == color isn't enough because of checkered pieces
d1be8046
BA
228 if (this.board[i][j] != V.EMPTY && this.getColor(i, j) != oppCol) {
229 const moves = this.getPotentialMovesFrom([i, j]);
230 if (moves.length > 0) {
231 for (let k = 0; k < moves.length; k++) {
232 if (this.filterValid([moves[k]]).length > 0) return true;
233 }
234 }
235 }
236 }
237 }
238 return false;
239 }
240
68e19a44
BA
241 // colors: array, generally 'w' and 'c' or 'b' and 'c'
242 isAttacked(sq, colors) {
32f6285e 243 if (!Array.isArray(colors)) colors = [colors];
68e19a44
BA
244 return (
245 this.isAttackedByPawn(sq, colors) ||
246 this.isAttackedByRook(sq, colors) ||
247 this.isAttackedByKnight(sq, colors) ||
248 this.isAttackedByBishop(sq, colors) ||
249 this.isAttackedByQueen(sq, colors) ||
250 this.isAttackedByKing(sq, colors)
251 );
252 }
253
6808d7a1
BA
254 isAttackedByPawn([x, y], colors) {
255 for (let c of colors) {
68e19a44 256 const color = (c == "c" ? this.turn : c);
6808d7a1
BA
257 let pawnShift = color == "w" ? 1 : -1;
258 if (x + pawnShift >= 0 && x + pawnShift < 8) {
259 for (let i of [-1, 1]) {
260 if (
261 y + i >= 0 &&
262 y + i < 8 &&
263 this.getPiece(x + pawnShift, y + i) == V.PAWN &&
264 this.getColor(x + pawnShift, y + i) == c
265 ) {
dac39588
BA
266 return true;
267 }
268 }
269 }
270 }
271 return false;
272 }
273
68e19a44
BA
274 isAttackedBySlideNJump([x, y], colors, piece, steps, oneStep) {
275 for (let step of steps) {
276 let rx = x + step[0],
277 ry = y + step[1];
278 while (V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && !oneStep) {
279 rx += step[0];
280 ry += step[1];
281 }
282 if (
283 V.OnBoard(rx, ry) &&
284 this.getPiece(rx, ry) === piece &&
285 colors.includes(this.getColor(rx, ry))
286 ) {
287 return true;
288 }
289 }
290 return false;
291 }
292
293 isAttackedByRook(sq, colors) {
294 return this.isAttackedBySlideNJump(sq, colors, V.ROOK, V.steps[V.ROOK]);
295 }
296
297 isAttackedByKnight(sq, colors) {
298 return this.isAttackedBySlideNJump(
299 sq,
300 colors,
301 V.KNIGHT,
302 V.steps[V.KNIGHT],
303 "oneStep"
304 );
305 }
306
307 isAttackedByBishop(sq, colors) {
2c5d7b20
BA
308 return this.isAttackedBySlideNJump(
309 sq, colors, V.BISHOP, V.steps[V.BISHOP]);
68e19a44
BA
310 }
311
312 isAttackedByQueen(sq, colors) {
313 return this.isAttackedBySlideNJump(
314 sq,
315 colors,
316 V.QUEEN,
317 V.steps[V.ROOK].concat(V.steps[V.BISHOP])
318 );
319 }
320
321 isAttackedByKing(sq, colors) {
322 return this.isAttackedBySlideNJump(
323 sq,
324 colors,
325 V.KING,
326 V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
327 "oneStep"
328 );
329 }
330
6808d7a1
BA
331 underCheck(color) {
332 return this.isAttacked(this.kingPos[color], [V.GetOppCol(color), "c"]);
dac39588
BA
333 }
334
af34341d
BA
335 getCheckSquares() {
336 const color = this.turn;
dac39588
BA
337 // Artifically change turn, for checkered pawns
338 this.turn = V.GetOppCol(color);
af34341d
BA
339 const kingAttacked =
340 this.isAttacked(
341 this.kingPos[color],
342 [this.turn, 'c']
343 );
dac39588 344 let res = kingAttacked
2c5d7b20 345 ? [JSON.parse(JSON.stringify(this.kingPos[color]))]
dac39588
BA
346 : [];
347 this.turn = color;
348 return res;
349 }
350
3a2a7b5f
BA
351 postPlay(move) {
352 super.postPlay(move);
dac39588 353 // Does this move turn off a 2-squares pawn flag?
3a2a7b5f 354 if ([1, 6].includes(move.start.x) && move.vanish[0].p == V.PAWN)
6808d7a1 355 this.pawnFlags[move.start.x == 6 ? "w" : "b"][move.start.y] = false;
3a2a7b5f
BA
356 this.cmoves.push(this.getCmove(move));
357 }
358
359 postUndo(move) {
360 super.postUndo(move);
361 this.cmoves.pop();
dac39588
BA
362 }
363
6808d7a1 364 getCurrentScore() {
bb688df5 365 if (this.atLeastOneMove()) return "*";
0c3fe8a6 366 const color = this.turn;
dac39588
BA
367 // Artifically change turn, for checkered pawns
368 this.turn = V.GetOppCol(this.turn);
6808d7a1
BA
369 const res = this.isAttacked(this.kingPos[color], [V.GetOppCol(color), "c"])
370 ? color == "w"
371 ? "0-1"
372 : "1-0"
dac39588
BA
373 : "1/2";
374 this.turn = V.GetOppCol(this.turn);
375 return res;
376 }
377
6808d7a1 378 evalPosition() {
dac39588 379 let evaluation = 0;
d1be8046 380 // Just count material for now, considering checkered neutral (...)
6808d7a1
BA
381 for (let i = 0; i < V.size.x; i++) {
382 for (let j = 0; j < V.size.y; j++) {
383 if (this.board[i][j] != V.EMPTY) {
384 const sqColor = this.getColor(i, j);
d1be8046
BA
385 if (["w","b"].includes(sqColor)) {
386 const sign = sqColor == "w" ? 1 : -1;
387 evaluation += sign * V.VALUES[this.getPiece(i, j)];
388 }
dac39588
BA
389 }
390 }
391 }
392 return evaluation;
393 }
394
7ba4a5bc 395 static GenRandInitFen(randomness) {
3a2a7b5f 396 // Add 16 pawns flags + empty cmove:
7ba4a5bc 397 return ChessRules.GenRandInitFen(randomness)
3a2a7b5f 398 .slice(0, -2) + "1111111111111111 - -";
dac39588 399 }
1d184b4c 400
6808d7a1 401 static ParseFen(fen) {
6f2f9437
BA
402 return Object.assign(
403 ChessRules.ParseFen(fen),
404 { cmove: fen.split(" ")[5] }
405 );
03cff0f7
BA
406 }
407
af34341d 408 getCmoveFen() {
03cff0f7 409 const L = this.cmoves.length;
af34341d 410 return (
305ede7e
BA
411 !this.cmoves[L - 1]
412 ? "-"
413 : ChessRules.CoordsToSquare(this.cmoves[L - 1].start) +
af34341d
BA
414 ChessRules.CoordsToSquare(this.cmoves[L - 1].end)
415 );
416 }
417
418 getFen() {
419 return super.getFen() + " " + this.getCmoveFen();
420 }
421
422 getFenForRepeat() {
423 return super.getFenForRepeat() + "_" + this.getCmoveFen();
03cff0f7
BA
424 }
425
6808d7a1 426 getFlagsFen() {
dac39588
BA
427 let fen = super.getFlagsFen();
428 // Add pawns flags
305ede7e
BA
429 for (let c of ["w", "b"])
430 for (let i = 0; i < 8; i++) fen += (this.pawnFlags[c][i] ? "1" : "0");
dac39588
BA
431 return fen;
432 }
1d184b4c 433
b83a675a
BA
434 static get SEARCH_DEPTH() {
435 return 2;
436 }
437
6808d7a1
BA
438 getNotation(move) {
439 if (move.appear.length == 2) {
dac39588 440 // Castle
6808d7a1
BA
441 if (move.end.y < move.start.y) return "0-0-0";
442 return "0-0";
dac39588
BA
443 }
444
dac39588 445 const finalSquare = V.CoordsToSquare(move.end);
dac39588 446 const piece = this.getPiece(move.start.x, move.start.y);
57d9b2c4 447 let notation = "";
6808d7a1 448 if (piece == V.PAWN) {
dac39588 449 // Pawn move
6808d7a1 450 if (move.vanish.length > 1) {
dac39588
BA
451 // Capture
452 const startColumn = V.CoordToColumn(move.start.y);
57d9b2c4
BA
453 notation = startColumn + "x" + finalSquare;
454 } else notation = finalSquare;
455 } else {
456 // Piece movement
457 notation =
458 piece.toUpperCase() +
459 (move.vanish.length > 1 ? "x" : "") +
460 finalSquare;
dac39588 461 }
57d9b2c4
BA
462 if (move.appear[0].p != move.vanish[0].p)
463 notation += "=" + move.appear[0].p.toUpperCase();
464 return notation;
dac39588 465 }
7e8a7ea1 466
6808d7a1 467};