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92342261 BA |
1 | // (Orthodox) Chess rules are defined in ChessRules class. |
2 | // Variants generally inherit from it, and modify some parts. | |
3 | ||
e2732923 | 4 | import { ArrayFun } from "@/utils/array"; |
0c3fe8a6 | 5 | import { randInt, shuffle } from "@/utils/alea"; |
e2732923 | 6 | |
910d631b | 7 | // class "PiPo": Piece + Position |
6808d7a1 | 8 | export const PiPo = class PiPo { |
1c9f093d | 9 | // o: {piece[p], color[c], posX[x], posY[y]} |
6808d7a1 | 10 | constructor(o) { |
1c9f093d BA |
11 | this.p = o.p; |
12 | this.c = o.c; | |
13 | this.x = o.x; | |
14 | this.y = o.y; | |
15 | } | |
6808d7a1 | 16 | }; |
1d184b4c | 17 | |
6808d7a1 | 18 | export const Move = class Move { |
1c9f093d BA |
19 | // o: {appear, vanish, [start,] [end,]} |
20 | // appear,vanish = arrays of PiPo | |
21 | // start,end = coordinates to apply to trigger move visually (think castle) | |
6808d7a1 | 22 | constructor(o) { |
1c9f093d BA |
23 | this.appear = o.appear; |
24 | this.vanish = o.vanish; | |
2da551a3 BA |
25 | this.start = o.start || { x: o.vanish[0].x, y: o.vanish[0].y }; |
26 | this.end = o.end || { x: o.appear[0].x, y: o.appear[0].y }; | |
1c9f093d | 27 | } |
6808d7a1 | 28 | }; |
1d184b4c | 29 | |
2c5d7b20 BA |
30 | // NOTE: x coords = top to bottom; y = left to right |
31 | // (from white player perspective) | |
6808d7a1 | 32 | export const ChessRules = class ChessRules { |
7e8a7ea1 | 33 | |
1c9f093d BA |
34 | ////////////// |
35 | // MISC UTILS | |
36 | ||
eb2d61de BA |
37 | static get Options() { |
38 | return { | |
39 | select: [ | |
40 | { | |
41 | label: "Randomness", | |
42 | variable: "randomness", | |
4313762d | 43 | defaut: 0, |
eb2d61de BA |
44 | options: [ |
45 | { label: "Deterministic", value: 0 }, | |
46 | { label: "Symmetric random", value: 1 }, | |
47 | { label: "Asymmetric random", value: 2 } | |
48 | ] | |
49 | } | |
50 | ], | |
51 | check: [] | |
52 | }; | |
53 | } | |
54 | ||
55 | static AbbreviateOptions(opts) { | |
56 | return ""; | |
57 | // Randomness is a special option: (TODO?) | |
58 | //return "R" + opts.randomness; | |
59 | } | |
60 | ||
4313762d BA |
61 | static IsValidOptions(opts) { |
62 | return true; | |
63 | } | |
64 | ||
20620465 | 65 | // Some variants don't have flags: |
6808d7a1 BA |
66 | static get HasFlags() { |
67 | return true; | |
20620465 | 68 | } |
1c9f093d | 69 | |
3a2a7b5f BA |
70 | // Or castle |
71 | static get HasCastle() { | |
72 | return V.HasFlags; | |
73 | } | |
74 | ||
32f6285e BA |
75 | // Pawns specifications |
76 | static get PawnSpecs() { | |
77 | return { | |
78 | directions: { 'w': -1, 'b': 1 }, | |
472c0c4f | 79 | initShift: { w: 1, b: 1 }, |
32f6285e | 80 | twoSquares: true, |
472c0c4f | 81 | threeSquares: false, |
32f6285e BA |
82 | promotions: [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN], |
83 | canCapture: true, | |
84 | captureBackward: false, | |
85 | bidirectional: false | |
86 | }; | |
87 | } | |
88 | ||
89 | // En-passant captures need a stack of squares: | |
6808d7a1 BA |
90 | static get HasEnpassant() { |
91 | return true; | |
20620465 BA |
92 | } |
93 | ||
94 | // Some variants cannot have analyse mode | |
8477e53d | 95 | static get CanAnalyze() { |
20620465 BA |
96 | return true; |
97 | } | |
933fd1f9 BA |
98 | // Patch: issues with javascript OOP, objects can't access static fields. |
99 | get canAnalyze() { | |
100 | return V.CanAnalyze; | |
101 | } | |
20620465 BA |
102 | |
103 | // Some variants show incomplete information, | |
104 | // and thus show only a partial moves list or no list at all. | |
105 | static get ShowMoves() { | |
106 | return "all"; | |
107 | } | |
933fd1f9 BA |
108 | get showMoves() { |
109 | return V.ShowMoves; | |
110 | } | |
1c9f093d | 111 | |
00eef1ca BA |
112 | // Sometimes moves must remain hidden until game ends |
113 | static get SomeHiddenMoves() { | |
114 | return false; | |
115 | } | |
116 | get someHiddenMoves() { | |
117 | return V.SomeHiddenMoves; | |
118 | } | |
119 | ||
ad030c7d BA |
120 | // Generally true, unless the variant includes random effects |
121 | static get CorrConfirm() { | |
122 | return true; | |
123 | } | |
124 | ||
5246b49d BA |
125 | // Used for Monochrome variant (TODO: harmonize: !canFlip ==> showFirstTurn) |
126 | get showFirstTurn() { | |
127 | return false; | |
128 | } | |
129 | ||
71ef1664 BA |
130 | // Some variants always show the same orientation |
131 | static get CanFlip() { | |
132 | return true; | |
133 | } | |
134 | get canFlip() { | |
135 | return V.CanFlip; | |
136 | } | |
137 | ||
107dc1bd BA |
138 | // For (generally old) variants without checkered board |
139 | static get Monochrome() { | |
140 | return false; | |
141 | } | |
142 | ||
173f11dc | 143 | // Some games are drawn unusually (bottom right corner is black) |
157a72c8 BA |
144 | static get DarkBottomRight() { |
145 | return false; | |
146 | } | |
147 | ||
107dc1bd BA |
148 | // Some variants require lines drawing |
149 | static get Lines() { | |
150 | if (V.Monochrome) { | |
151 | let lines = []; | |
152 | // Draw all inter-squares lines | |
153 | for (let i = 0; i <= V.size.x; i++) | |
154 | lines.push([[i, 0], [i, V.size.y]]); | |
155 | for (let j = 0; j <= V.size.y; j++) | |
156 | lines.push([[0, j], [V.size.x, j]]); | |
157 | return lines; | |
158 | } | |
159 | return null; | |
160 | } | |
161 | ||
9a1e3abe BA |
162 | // In some variants, the player who repeat a position loses |
163 | static get LoseOnRepetition() { | |
d2af3400 BA |
164 | return false; |
165 | } | |
f0a812b7 BA |
166 | // And in some others (Iceage), repetitions should be ignored: |
167 | static get IgnoreRepetition() { | |
168 | return false; | |
169 | } | |
809ab1a8 BA |
170 | loseOnRepetition() { |
171 | // In some variants, result depends on the position: | |
172 | return V.LoseOnRepetition; | |
173 | } | |
d2af3400 BA |
174 | |
175 | // At some stages, some games could wait clicks only: | |
176 | onlyClick() { | |
9a1e3abe BA |
177 | return false; |
178 | } | |
179 | ||
61656127 BA |
180 | // Some variants use click infos: |
181 | doClick() { | |
182 | return null; | |
183 | } | |
184 | ||
90df90bc BA |
185 | // Some variants may need to highlight squares on hover (Hamilton, Weiqi...) |
186 | hoverHighlight() { | |
187 | return false; | |
188 | } | |
189 | ||
14edde72 BA |
190 | static get IMAGE_EXTENSION() { |
191 | // All pieces should be in the SVG format | |
192 | return ".svg"; | |
193 | } | |
194 | ||
1c9f093d | 195 | // Turn "wb" into "B" (for FEN) |
6808d7a1 BA |
196 | static board2fen(b) { |
197 | return b[0] == "w" ? b[1].toUpperCase() : b[1]; | |
1c9f093d BA |
198 | } |
199 | ||
200 | // Turn "p" into "bp" (for board) | |
6808d7a1 | 201 | static fen2board(f) { |
6cc34165 | 202 | return f.charCodeAt(0) <= 90 ? "w" + f.toLowerCase() : "b" + f; |
1c9f093d BA |
203 | } |
204 | ||
68e19a44 | 205 | // Check if FEN describes a board situation correctly |
6808d7a1 | 206 | static IsGoodFen(fen) { |
1c9f093d BA |
207 | const fenParsed = V.ParseFen(fen); |
208 | // 1) Check position | |
6808d7a1 | 209 | if (!V.IsGoodPosition(fenParsed.position)) return false; |
1c9f093d | 210 | // 2) Check turn |
6808d7a1 | 211 | if (!fenParsed.turn || !V.IsGoodTurn(fenParsed.turn)) return false; |
1c9f093d | 212 | // 3) Check moves count |
e50a8025 | 213 | if (!fenParsed.movesCount || !(parseInt(fenParsed.movesCount, 10) >= 0)) |
1c9f093d BA |
214 | return false; |
215 | // 4) Check flags | |
216 | if (V.HasFlags && (!fenParsed.flags || !V.IsGoodFlags(fenParsed.flags))) | |
217 | return false; | |
218 | // 5) Check enpassant | |
6808d7a1 BA |
219 | if ( |
220 | V.HasEnpassant && | |
221 | (!fenParsed.enpassant || !V.IsGoodEnpassant(fenParsed.enpassant)) | |
222 | ) { | |
1c9f093d BA |
223 | return false; |
224 | } | |
225 | return true; | |
226 | } | |
227 | ||
228 | // Is position part of the FEN a priori correct? | |
6808d7a1 BA |
229 | static IsGoodPosition(position) { |
230 | if (position.length == 0) return false; | |
1c9f093d | 231 | const rows = position.split("/"); |
6808d7a1 | 232 | if (rows.length != V.size.x) return false; |
6f2f9437 | 233 | let kings = { "k": 0, "K": 0 }; |
6808d7a1 | 234 | for (let row of rows) { |
1c9f093d | 235 | let sumElts = 0; |
6808d7a1 | 236 | for (let i = 0; i < row.length; i++) { |
6f2f9437 | 237 | if (['K','k'].includes(row[i])) kings[row[i]]++; |
6808d7a1 BA |
238 | if (V.PIECES.includes(row[i].toLowerCase())) sumElts++; |
239 | else { | |
e50a8025 | 240 | const num = parseInt(row[i], 10); |
173f11dc | 241 | if (isNaN(num) || num <= 0) return false; |
1c9f093d BA |
242 | sumElts += num; |
243 | } | |
244 | } | |
6808d7a1 | 245 | if (sumElts != V.size.y) return false; |
1c9f093d | 246 | } |
6f2f9437 BA |
247 | // Both kings should be on board. Exactly one per color. |
248 | if (Object.values(kings).some(v => v != 1)) return false; | |
1c9f093d BA |
249 | return true; |
250 | } | |
251 | ||
252 | // For FEN checking | |
6808d7a1 BA |
253 | static IsGoodTurn(turn) { |
254 | return ["w", "b"].includes(turn); | |
1c9f093d BA |
255 | } |
256 | ||
257 | // For FEN checking | |
6808d7a1 | 258 | static IsGoodFlags(flags) { |
3a2a7b5f BA |
259 | // NOTE: a little too permissive to work with more variants |
260 | return !!flags.match(/^[a-z]{4,4}$/); | |
1c9f093d BA |
261 | } |
262 | ||
472c0c4f | 263 | // NOTE: not with regexp to adapt to different board sizes. (TODO?) |
6808d7a1 BA |
264 | static IsGoodEnpassant(enpassant) { |
265 | if (enpassant != "-") { | |
266 | const ep = V.SquareToCoords(enpassant); | |
267 | if (isNaN(ep.x) || !V.OnBoard(ep)) return false; | |
1c9f093d BA |
268 | } |
269 | return true; | |
270 | } | |
271 | ||
272 | // 3 --> d (column number to letter) | |
6808d7a1 | 273 | static CoordToColumn(colnum) { |
1c9f093d BA |
274 | return String.fromCharCode(97 + colnum); |
275 | } | |
276 | ||
277 | // d --> 3 (column letter to number) | |
6808d7a1 | 278 | static ColumnToCoord(column) { |
1c9f093d BA |
279 | return column.charCodeAt(0) - 97; |
280 | } | |
281 | ||
282 | // a4 --> {x:3,y:0} | |
6808d7a1 | 283 | static SquareToCoords(sq) { |
1c9f093d BA |
284 | return { |
285 | // NOTE: column is always one char => max 26 columns | |
286 | // row is counted from black side => subtraction | |
e50a8025 | 287 | x: V.size.x - parseInt(sq.substr(1), 10), |
1c9f093d BA |
288 | y: sq[0].charCodeAt() - 97 |
289 | }; | |
290 | } | |
291 | ||
292 | // {x:0,y:4} --> e8 | |
6808d7a1 | 293 | static CoordsToSquare(coords) { |
1c9f093d BA |
294 | return V.CoordToColumn(coords.y) + (V.size.x - coords.x); |
295 | } | |
296 | ||
305ede7e | 297 | // Path to pieces (standard ones in pieces/ folder) |
241bf8f2 | 298 | getPpath(b) { |
305ede7e | 299 | return b; |
241bf8f2 BA |
300 | } |
301 | ||
3a2a7b5f | 302 | // Path to promotion pieces (usually the same) |
c7550017 BA |
303 | getPPpath(m) { |
304 | return this.getPpath(m.appear[0].c + m.appear[0].p); | |
3a2a7b5f BA |
305 | } |
306 | ||
1c9f093d | 307 | // Aggregates flags into one object |
6808d7a1 | 308 | aggregateFlags() { |
1c9f093d BA |
309 | return this.castleFlags; |
310 | } | |
311 | ||
312 | // Reverse operation | |
6808d7a1 | 313 | disaggregateFlags(flags) { |
1c9f093d BA |
314 | this.castleFlags = flags; |
315 | } | |
316 | ||
317 | // En-passant square, if any | |
6808d7a1 | 318 | getEpSquare(moveOrSquare) { |
4a209313 | 319 | if (!moveOrSquare) return undefined; //TODO: necessary line?! |
6808d7a1 | 320 | if (typeof moveOrSquare === "string") { |
1c9f093d | 321 | const square = moveOrSquare; |
6808d7a1 | 322 | if (square == "-") return undefined; |
1c9f093d BA |
323 | return V.SquareToCoords(square); |
324 | } | |
325 | // Argument is a move: | |
326 | const move = moveOrSquare; | |
1c5bfdf2 BA |
327 | const s = move.start, |
328 | e = move.end; | |
6808d7a1 | 329 | if ( |
1c5bfdf2 | 330 | s.y == e.y && |
0d5335de BA |
331 | Math.abs(s.x - e.x) == 2 && |
332 | // Next conditions for variants like Atomic or Rifle, Recycle... | |
333 | (move.appear.length > 0 && move.appear[0].p == V.PAWN) && | |
334 | (move.vanish.length > 0 && move.vanish[0].p == V.PAWN) | |
6808d7a1 | 335 | ) { |
1c9f093d | 336 | return { |
1c5bfdf2 BA |
337 | x: (s.x + e.x) / 2, |
338 | y: s.y | |
1c9f093d BA |
339 | }; |
340 | } | |
341 | return undefined; //default | |
342 | } | |
343 | ||
344 | // Can thing on square1 take thing on square2 | |
6808d7a1 BA |
345 | canTake([x1, y1], [x2, y2]) { |
346 | return this.getColor(x1, y1) !== this.getColor(x2, y2); | |
1c9f093d BA |
347 | } |
348 | ||
349 | // Is (x,y) on the chessboard? | |
6808d7a1 BA |
350 | static OnBoard(x, y) { |
351 | return x >= 0 && x < V.size.x && y >= 0 && y < V.size.y; | |
1c9f093d BA |
352 | } |
353 | ||
354 | // Used in interface: 'side' arg == player color | |
6808d7a1 BA |
355 | canIplay(side, [x, y]) { |
356 | return this.turn == side && this.getColor(x, y) == side; | |
1c9f093d BA |
357 | } |
358 | ||
359 | // On which squares is color under check ? (for interface) | |
af34341d BA |
360 | getCheckSquares() { |
361 | const color = this.turn; | |
b0a0468a BA |
362 | return ( |
363 | this.underCheck(color) | |
2c5d7b20 BA |
364 | // kingPos must be duplicated, because it may change: |
365 | ? [JSON.parse(JSON.stringify(this.kingPos[color]))] | |
b0a0468a BA |
366 | : [] |
367 | ); | |
1c9f093d BA |
368 | } |
369 | ||
370 | ///////////// | |
371 | // FEN UTILS | |
372 | ||
7ba4a5bc | 373 | // Setup the initial random (asymmetric) position |
eb2d61de | 374 | static GenRandInitFen(options) { |
4313762d | 375 | if (!options.randomness || options.randomness == 0) |
7ba4a5bc | 376 | // Deterministic: |
3a2a7b5f | 377 | return "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w 0 ahah -"; |
7ba4a5bc | 378 | |
6808d7a1 | 379 | let pieces = { w: new Array(8), b: new Array(8) }; |
3a2a7b5f | 380 | let flags = ""; |
7ba4a5bc | 381 | // Shuffle pieces on first (and last rank if randomness == 2) |
6808d7a1 | 382 | for (let c of ["w", "b"]) { |
eb2d61de | 383 | if (c == 'b' && options.randomness == 1) { |
7ba4a5bc | 384 | pieces['b'] = pieces['w']; |
3a2a7b5f | 385 | flags += flags; |
7ba4a5bc BA |
386 | break; |
387 | } | |
388 | ||
1c9f093d BA |
389 | let positions = ArrayFun.range(8); |
390 | ||
391 | // Get random squares for bishops | |
656b1878 | 392 | let randIndex = 2 * randInt(4); |
1c9f093d BA |
393 | const bishop1Pos = positions[randIndex]; |
394 | // The second bishop must be on a square of different color | |
656b1878 | 395 | let randIndex_tmp = 2 * randInt(4) + 1; |
1c9f093d BA |
396 | const bishop2Pos = positions[randIndex_tmp]; |
397 | // Remove chosen squares | |
6808d7a1 BA |
398 | positions.splice(Math.max(randIndex, randIndex_tmp), 1); |
399 | positions.splice(Math.min(randIndex, randIndex_tmp), 1); | |
1c9f093d BA |
400 | |
401 | // Get random squares for knights | |
656b1878 | 402 | randIndex = randInt(6); |
1c9f093d BA |
403 | const knight1Pos = positions[randIndex]; |
404 | positions.splice(randIndex, 1); | |
656b1878 | 405 | randIndex = randInt(5); |
1c9f093d BA |
406 | const knight2Pos = positions[randIndex]; |
407 | positions.splice(randIndex, 1); | |
408 | ||
409 | // Get random square for queen | |
656b1878 | 410 | randIndex = randInt(4); |
1c9f093d BA |
411 | const queenPos = positions[randIndex]; |
412 | positions.splice(randIndex, 1); | |
413 | ||
414 | // Rooks and king positions are now fixed, | |
415 | // because of the ordering rook-king-rook | |
416 | const rook1Pos = positions[0]; | |
417 | const kingPos = positions[1]; | |
418 | const rook2Pos = positions[2]; | |
419 | ||
420 | // Finally put the shuffled pieces in the board array | |
6808d7a1 BA |
421 | pieces[c][rook1Pos] = "r"; |
422 | pieces[c][knight1Pos] = "n"; | |
423 | pieces[c][bishop1Pos] = "b"; | |
424 | pieces[c][queenPos] = "q"; | |
425 | pieces[c][kingPos] = "k"; | |
426 | pieces[c][bishop2Pos] = "b"; | |
427 | pieces[c][knight2Pos] = "n"; | |
428 | pieces[c][rook2Pos] = "r"; | |
3a2a7b5f | 429 | flags += V.CoordToColumn(rook1Pos) + V.CoordToColumn(rook2Pos); |
1c9f093d | 430 | } |
e3e2cc44 | 431 | // Add turn + flags + enpassant |
6808d7a1 BA |
432 | return ( |
433 | pieces["b"].join("") + | |
1c9f093d BA |
434 | "/pppppppp/8/8/8/8/PPPPPPPP/" + |
435 | pieces["w"].join("").toUpperCase() + | |
3a2a7b5f | 436 | " w 0 " + flags + " -" |
e3e2cc44 | 437 | ); |
1c9f093d BA |
438 | } |
439 | ||
440 | // "Parse" FEN: just return untransformed string data | |
6808d7a1 | 441 | static ParseFen(fen) { |
1c9f093d | 442 | const fenParts = fen.split(" "); |
6808d7a1 | 443 | let res = { |
1c9f093d BA |
444 | position: fenParts[0], |
445 | turn: fenParts[1], | |
6808d7a1 | 446 | movesCount: fenParts[2] |
1c9f093d BA |
447 | }; |
448 | let nextIdx = 3; | |
6808d7a1 BA |
449 | if (V.HasFlags) Object.assign(res, { flags: fenParts[nextIdx++] }); |
450 | if (V.HasEnpassant) Object.assign(res, { enpassant: fenParts[nextIdx] }); | |
1c9f093d BA |
451 | return res; |
452 | } | |
453 | ||
454 | // Return current fen (game state) | |
6808d7a1 BA |
455 | getFen() { |
456 | return ( | |
f9c36b2d BA |
457 | this.getBaseFen() + " " + |
458 | this.getTurnFen() + " " + | |
6808d7a1 BA |
459 | this.movesCount + |
460 | (V.HasFlags ? " " + this.getFlagsFen() : "") + | |
461 | (V.HasEnpassant ? " " + this.getEnpassantFen() : "") | |
462 | ); | |
1c9f093d BA |
463 | } |
464 | ||
f9c36b2d BA |
465 | getFenForRepeat() { |
466 | // Omit movesCount, only variable allowed to differ | |
467 | return ( | |
468 | this.getBaseFen() + "_" + | |
469 | this.getTurnFen() + | |
470 | (V.HasFlags ? "_" + this.getFlagsFen() : "") + | |
471 | (V.HasEnpassant ? "_" + this.getEnpassantFen() : "") | |
472 | ); | |
473 | } | |
474 | ||
1c9f093d | 475 | // Position part of the FEN string |
6808d7a1 | 476 | getBaseFen() { |
6f2f9437 BA |
477 | const format = (count) => { |
478 | // if more than 9 consecutive free spaces, break the integer, | |
479 | // otherwise FEN parsing will fail. | |
480 | if (count <= 9) return count; | |
7c05a5f2 BA |
481 | // Most boards of size < 18: |
482 | if (count <= 18) return "9" + (count - 9); | |
483 | // Except Gomoku: | |
484 | return "99" + (count - 18); | |
6f2f9437 | 485 | }; |
1c9f093d | 486 | let position = ""; |
6808d7a1 | 487 | for (let i = 0; i < V.size.x; i++) { |
1c9f093d | 488 | let emptyCount = 0; |
6808d7a1 BA |
489 | for (let j = 0; j < V.size.y; j++) { |
490 | if (this.board[i][j] == V.EMPTY) emptyCount++; | |
491 | else { | |
492 | if (emptyCount > 0) { | |
1c9f093d | 493 | // Add empty squares in-between |
6f2f9437 | 494 | position += format(emptyCount); |
1c9f093d BA |
495 | emptyCount = 0; |
496 | } | |
497 | position += V.board2fen(this.board[i][j]); | |
498 | } | |
499 | } | |
6808d7a1 | 500 | if (emptyCount > 0) { |
1c9f093d | 501 | // "Flush remainder" |
6f2f9437 | 502 | position += format(emptyCount); |
1c9f093d | 503 | } |
6808d7a1 | 504 | if (i < V.size.x - 1) position += "/"; //separate rows |
1c9f093d BA |
505 | } |
506 | return position; | |
507 | } | |
508 | ||
6808d7a1 | 509 | getTurnFen() { |
1c9f093d BA |
510 | return this.turn; |
511 | } | |
512 | ||
513 | // Flags part of the FEN string | |
6808d7a1 | 514 | getFlagsFen() { |
1c9f093d | 515 | let flags = ""; |
3a2a7b5f BA |
516 | // Castling flags |
517 | for (let c of ["w", "b"]) | |
518 | flags += this.castleFlags[c].map(V.CoordToColumn).join(""); | |
1c9f093d BA |
519 | return flags; |
520 | } | |
521 | ||
522 | // Enpassant part of the FEN string | |
6808d7a1 | 523 | getEnpassantFen() { |
1c9f093d | 524 | const L = this.epSquares.length; |
6808d7a1 BA |
525 | if (!this.epSquares[L - 1]) return "-"; //no en-passant |
526 | return V.CoordsToSquare(this.epSquares[L - 1]); | |
1c9f093d BA |
527 | } |
528 | ||
529 | // Turn position fen into double array ["wb","wp","bk",...] | |
6808d7a1 | 530 | static GetBoard(position) { |
1c9f093d BA |
531 | const rows = position.split("/"); |
532 | let board = ArrayFun.init(V.size.x, V.size.y, ""); | |
6808d7a1 | 533 | for (let i = 0; i < rows.length; i++) { |
1c9f093d | 534 | let j = 0; |
6808d7a1 | 535 | for (let indexInRow = 0; indexInRow < rows[i].length; indexInRow++) { |
1c9f093d | 536 | const character = rows[i][indexInRow]; |
e50a8025 | 537 | const num = parseInt(character, 10); |
a13cbc0f | 538 | // If num is a number, just shift j: |
6808d7a1 | 539 | if (!isNaN(num)) j += num; |
a13cbc0f | 540 | // Else: something at position i,j |
6808d7a1 | 541 | else board[i][j++] = V.fen2board(character); |
1c9f093d BA |
542 | } |
543 | } | |
544 | return board; | |
545 | } | |
546 | ||
547 | // Extract (relevant) flags from fen | |
6808d7a1 | 548 | setFlags(fenflags) { |
1c9f093d | 549 | // white a-castle, h-castle, black a-castle, h-castle |
bb688df5 | 550 | this.castleFlags = { w: [-1, -1], b: [-1, -1] }; |
3a2a7b5f BA |
551 | for (let i = 0; i < 4; i++) { |
552 | this.castleFlags[i < 2 ? "w" : "b"][i % 2] = | |
553 | V.ColumnToCoord(fenflags.charAt(i)); | |
554 | } | |
1c9f093d BA |
555 | } |
556 | ||
557 | ////////////////// | |
558 | // INITIALIZATION | |
559 | ||
37cdcbf3 | 560 | // Fen string fully describes the game state |
b627d118 BA |
561 | constructor(fen) { |
562 | if (!fen) | |
563 | // In printDiagram() fen isn't supply because only getPpath() is used | |
564 | // TODO: find a better solution! | |
565 | return; | |
1c9f093d BA |
566 | const fenParsed = V.ParseFen(fen); |
567 | this.board = V.GetBoard(fenParsed.position); | |
af34341d | 568 | this.turn = fenParsed.turn; |
e50a8025 | 569 | this.movesCount = parseInt(fenParsed.movesCount, 10); |
1c9f093d BA |
570 | this.setOtherVariables(fen); |
571 | } | |
572 | ||
3a2a7b5f | 573 | // Scan board for kings positions |
9d15c433 | 574 | // TODO: should be done from board, no need for the complete FEN |
3a2a7b5f | 575 | scanKings(fen) { |
2c5d7b20 BA |
576 | // Squares of white and black king: |
577 | this.kingPos = { w: [-1, -1], b: [-1, -1] }; | |
1c9f093d | 578 | const fenRows = V.ParseFen(fen).position.split("/"); |
6808d7a1 | 579 | for (let i = 0; i < fenRows.length; i++) { |
1c9f093d | 580 | let k = 0; //column index on board |
6808d7a1 BA |
581 | for (let j = 0; j < fenRows[i].length; j++) { |
582 | switch (fenRows[i].charAt(j)) { | |
583 | case "k": | |
584 | this.kingPos["b"] = [i, k]; | |
1c9f093d | 585 | break; |
6808d7a1 BA |
586 | case "K": |
587 | this.kingPos["w"] = [i, k]; | |
1c9f093d | 588 | break; |
6808d7a1 | 589 | default: { |
e50a8025 | 590 | const num = parseInt(fenRows[i].charAt(j), 10); |
6808d7a1 BA |
591 | if (!isNaN(num)) k += num - 1; |
592 | } | |
1c9f093d BA |
593 | } |
594 | k++; | |
595 | } | |
596 | } | |
597 | } | |
598 | ||
599 | // Some additional variables from FEN (variant dependant) | |
6808d7a1 | 600 | setOtherVariables(fen) { |
1c9f093d BA |
601 | // Set flags and enpassant: |
602 | const parsedFen = V.ParseFen(fen); | |
6808d7a1 BA |
603 | if (V.HasFlags) this.setFlags(parsedFen.flags); |
604 | if (V.HasEnpassant) { | |
605 | const epSq = | |
606 | parsedFen.enpassant != "-" | |
9bd6786b | 607 | ? this.getEpSquare(parsedFen.enpassant) |
6808d7a1 BA |
608 | : undefined; |
609 | this.epSquares = [epSq]; | |
1c9f093d | 610 | } |
3a2a7b5f BA |
611 | // Search for kings positions: |
612 | this.scanKings(fen); | |
1c9f093d BA |
613 | } |
614 | ||
615 | ///////////////////// | |
616 | // GETTERS & SETTERS | |
617 | ||
6808d7a1 BA |
618 | static get size() { |
619 | return { x: 8, y: 8 }; | |
1c9f093d BA |
620 | } |
621 | ||
0ba6420d | 622 | // Color of thing on square (i,j). 'undefined' if square is empty |
6808d7a1 | 623 | getColor(i, j) { |
1c9f093d BA |
624 | return this.board[i][j].charAt(0); |
625 | } | |
626 | ||
627 | // Piece type on square (i,j). 'undefined' if square is empty | |
6808d7a1 | 628 | getPiece(i, j) { |
1c9f093d BA |
629 | return this.board[i][j].charAt(1); |
630 | } | |
631 | ||
632 | // Get opponent color | |
6808d7a1 BA |
633 | static GetOppCol(color) { |
634 | return color == "w" ? "b" : "w"; | |
1c9f093d BA |
635 | } |
636 | ||
1c9f093d | 637 | // Pieces codes (for a clearer code) |
6808d7a1 BA |
638 | static get PAWN() { |
639 | return "p"; | |
640 | } | |
641 | static get ROOK() { | |
642 | return "r"; | |
643 | } | |
644 | static get KNIGHT() { | |
645 | return "n"; | |
646 | } | |
647 | static get BISHOP() { | |
648 | return "b"; | |
649 | } | |
650 | static get QUEEN() { | |
651 | return "q"; | |
652 | } | |
653 | static get KING() { | |
654 | return "k"; | |
655 | } | |
1c9f093d BA |
656 | |
657 | // For FEN checking: | |
6808d7a1 BA |
658 | static get PIECES() { |
659 | return [V.PAWN, V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN, V.KING]; | |
1c9f093d BA |
660 | } |
661 | ||
662 | // Empty square | |
6808d7a1 BA |
663 | static get EMPTY() { |
664 | return ""; | |
665 | } | |
1c9f093d BA |
666 | |
667 | // Some pieces movements | |
6808d7a1 | 668 | static get steps() { |
1c9f093d | 669 | return { |
6808d7a1 BA |
670 | r: [ |
671 | [-1, 0], | |
672 | [1, 0], | |
673 | [0, -1], | |
674 | [0, 1] | |
675 | ], | |
676 | n: [ | |
677 | [-1, -2], | |
678 | [-1, 2], | |
679 | [1, -2], | |
680 | [1, 2], | |
681 | [-2, -1], | |
682 | [-2, 1], | |
683 | [2, -1], | |
684 | [2, 1] | |
685 | ], | |
686 | b: [ | |
687 | [-1, -1], | |
688 | [-1, 1], | |
689 | [1, -1], | |
690 | [1, 1] | |
691 | ] | |
1c9f093d BA |
692 | }; |
693 | } | |
694 | ||
695 | //////////////////// | |
696 | // MOVES GENERATION | |
697 | ||
0ba6420d | 698 | // All possible moves from selected square |
173f11dc BA |
699 | getPotentialMovesFrom(sq) { |
700 | switch (this.getPiece(sq[0], sq[1])) { | |
701 | case V.PAWN: return this.getPotentialPawnMoves(sq); | |
702 | case V.ROOK: return this.getPotentialRookMoves(sq); | |
703 | case V.KNIGHT: return this.getPotentialKnightMoves(sq); | |
704 | case V.BISHOP: return this.getPotentialBishopMoves(sq); | |
705 | case V.QUEEN: return this.getPotentialQueenMoves(sq); | |
706 | case V.KING: return this.getPotentialKingMoves(sq); | |
1c9f093d | 707 | } |
2a0672a9 | 708 | return []; //never reached (but some variants may use it: Bario...) |
1c9f093d BA |
709 | } |
710 | ||
711 | // Build a regular move from its initial and destination squares. | |
712 | // tr: transformation | |
6808d7a1 | 713 | getBasicMove([sx, sy], [ex, ey], tr) { |
1c58eb76 | 714 | const initColor = this.getColor(sx, sy); |
7e8a7ea1 | 715 | const initPiece = this.board[sx][sy].charAt(1); |
1c9f093d BA |
716 | let mv = new Move({ |
717 | appear: [ | |
718 | new PiPo({ | |
719 | x: ex, | |
720 | y: ey, | |
173f11dc BA |
721 | c: !!tr ? tr.c : initColor, |
722 | p: !!tr ? tr.p : initPiece | |
1c9f093d BA |
723 | }) |
724 | ], | |
725 | vanish: [ | |
726 | new PiPo({ | |
727 | x: sx, | |
728 | y: sy, | |
1c58eb76 BA |
729 | c: initColor, |
730 | p: initPiece | |
1c9f093d BA |
731 | }) |
732 | ] | |
733 | }); | |
734 | ||
735 | // The opponent piece disappears if we take it | |
6808d7a1 | 736 | if (this.board[ex][ey] != V.EMPTY) { |
1c9f093d BA |
737 | mv.vanish.push( |
738 | new PiPo({ | |
739 | x: ex, | |
740 | y: ey, | |
6808d7a1 | 741 | c: this.getColor(ex, ey), |
7e8a7ea1 | 742 | p: this.board[ex][ey].charAt(1) |
1c9f093d BA |
743 | }) |
744 | ); | |
745 | } | |
1c5bfdf2 | 746 | |
1c9f093d BA |
747 | return mv; |
748 | } | |
749 | ||
750 | // Generic method to find possible moves of non-pawn pieces: | |
751 | // "sliding or jumping" | |
4313762d | 752 | getSlideNJumpMoves([x, y], steps, nbSteps) { |
1c9f093d | 753 | let moves = []; |
6808d7a1 | 754 | outerLoop: for (let step of steps) { |
1c9f093d BA |
755 | let i = x + step[0]; |
756 | let j = y + step[1]; | |
4313762d | 757 | let stepCounter = 0; |
6808d7a1 BA |
758 | while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) { |
759 | moves.push(this.getBasicMove([x, y], [i, j])); | |
4313762d | 760 | if (nbSteps && ++stepCounter >= nbSteps) continue outerLoop; |
1c9f093d BA |
761 | i += step[0]; |
762 | j += step[1]; | |
763 | } | |
6808d7a1 BA |
764 | if (V.OnBoard(i, j) && this.canTake([x, y], [i, j])) |
765 | moves.push(this.getBasicMove([x, y], [i, j])); | |
1c9f093d BA |
766 | } |
767 | return moves; | |
768 | } | |
769 | ||
32f6285e BA |
770 | // Special case of en-passant captures: treated separately |
771 | getEnpassantCaptures([x, y], shiftX) { | |
772 | const Lep = this.epSquares.length; | |
773 | const epSquare = this.epSquares[Lep - 1]; //always at least one element | |
774 | let enpassantMove = null; | |
775 | if ( | |
776 | !!epSquare && | |
777 | epSquare.x == x + shiftX && | |
778 | Math.abs(epSquare.y - y) == 1 | |
779 | ) { | |
780 | enpassantMove = this.getBasicMove([x, y], [epSquare.x, epSquare.y]); | |
781 | enpassantMove.vanish.push({ | |
782 | x: x, | |
783 | y: epSquare.y, | |
7e8a7ea1 | 784 | p: this.board[x][epSquare.y].charAt(1), |
32f6285e BA |
785 | c: this.getColor(x, epSquare.y) |
786 | }); | |
787 | } | |
788 | return !!enpassantMove ? [enpassantMove] : []; | |
789 | } | |
790 | ||
1c58eb76 BA |
791 | // Consider all potential promotions: |
792 | addPawnMoves([x1, y1], [x2, y2], moves, promotions) { | |
793 | let finalPieces = [V.PAWN]; | |
af34341d | 794 | const color = this.turn; //this.getColor(x1, y1); |
1c58eb76 BA |
795 | const lastRank = (color == "w" ? 0 : V.size.x - 1); |
796 | if (x2 == lastRank) { | |
797 | // promotions arg: special override for Hiddenqueen variant | |
798 | if (!!promotions) finalPieces = promotions; | |
15d69043 | 799 | else if (!!V.PawnSpecs.promotions) finalPieces = V.PawnSpecs.promotions; |
1c58eb76 | 800 | } |
1c58eb76 | 801 | for (let piece of finalPieces) { |
3b98a861 | 802 | const tr = (piece != V.PAWN ? { c: color, p: piece } : null); |
1c58eb76 BA |
803 | moves.push(this.getBasicMove([x1, y1], [x2, y2], tr)); |
804 | } | |
805 | } | |
806 | ||
1c9f093d | 807 | // What are the pawn moves from square x,y ? |
32f6285e | 808 | getPotentialPawnMoves([x, y], promotions) { |
af34341d | 809 | const color = this.turn; //this.getColor(x, y); |
6808d7a1 | 810 | const [sizeX, sizeY] = [V.size.x, V.size.y]; |
32f6285e | 811 | const pawnShiftX = V.PawnSpecs.directions[color]; |
1c58eb76 | 812 | const firstRank = (color == "w" ? sizeX - 1 : 0); |
0b8bd121 | 813 | const forward = (color == 'w' ? -1 : 1); |
32f6285e BA |
814 | |
815 | // Pawn movements in shiftX direction: | |
816 | const getPawnMoves = (shiftX) => { | |
817 | let moves = []; | |
818 | // NOTE: next condition is generally true (no pawn on last rank) | |
819 | if (x + shiftX >= 0 && x + shiftX < sizeX) { | |
820 | if (this.board[x + shiftX][y] == V.EMPTY) { | |
0b8bd121 | 821 | // One square forward (or backward) |
1c58eb76 | 822 | this.addPawnMoves([x, y], [x + shiftX, y], moves, promotions); |
32f6285e BA |
823 | // Next condition because pawns on 1st rank can generally jump |
824 | if ( | |
825 | V.PawnSpecs.twoSquares && | |
472c0c4f BA |
826 | ( |
827 | (color == 'w' && x >= V.size.x - 1 - V.PawnSpecs.initShift['w']) | |
828 | || | |
829 | (color == 'b' && x <= V.PawnSpecs.initShift['b']) | |
830 | ) | |
32f6285e | 831 | ) { |
0b8bd121 BA |
832 | if ( |
833 | shiftX == forward && | |
834 | this.board[x + 2 * shiftX][y] == V.EMPTY | |
835 | ) { | |
472c0c4f BA |
836 | // Two squares jump |
837 | moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y])); | |
838 | if ( | |
839 | V.PawnSpecs.threeSquares && | |
840 | this.board[x + 3 * shiftX][y] == V.EMPTY | |
841 | ) { | |
842 | // Three squares jump | |
843 | moves.push(this.getBasicMove([x, y], [x + 3 * shiftX, y])); | |
844 | } | |
845 | } | |
32f6285e BA |
846 | } |
847 | } | |
848 | // Captures | |
849 | if (V.PawnSpecs.canCapture) { | |
850 | for (let shiftY of [-1, 1]) { | |
15d69043 | 851 | if (y + shiftY >= 0 && y + shiftY < sizeY) { |
32f6285e BA |
852 | if ( |
853 | this.board[x + shiftX][y + shiftY] != V.EMPTY && | |
854 | this.canTake([x, y], [x + shiftX, y + shiftY]) | |
855 | ) { | |
1c58eb76 BA |
856 | this.addPawnMoves( |
857 | [x, y], [x + shiftX, y + shiftY], | |
858 | moves, promotions | |
859 | ); | |
32f6285e BA |
860 | } |
861 | if ( | |
0b8bd121 | 862 | V.PawnSpecs.captureBackward && shiftX == forward && |
32f6285e BA |
863 | x - shiftX >= 0 && x - shiftX < V.size.x && |
864 | this.board[x - shiftX][y + shiftY] != V.EMPTY && | |
865 | this.canTake([x, y], [x - shiftX, y + shiftY]) | |
866 | ) { | |
1c58eb76 | 867 | this.addPawnMoves( |
0b8bd121 | 868 | [x, y], [x - shiftX, y + shiftY], |
1c58eb76 BA |
869 | moves, promotions |
870 | ); | |
32f6285e BA |
871 | } |
872 | } | |
1c9f093d BA |
873 | } |
874 | } | |
875 | } | |
32f6285e | 876 | return moves; |
1c9f093d BA |
877 | } |
878 | ||
32f6285e BA |
879 | let pMoves = getPawnMoves(pawnShiftX); |
880 | if (V.PawnSpecs.bidirectional) | |
881 | pMoves = pMoves.concat(getPawnMoves(-pawnShiftX)); | |
882 | ||
6808d7a1 | 883 | if (V.HasEnpassant) { |
32f6285e BA |
884 | // NOTE: backward en-passant captures are not considered |
885 | // because no rules define them (for now). | |
886 | Array.prototype.push.apply( | |
887 | pMoves, | |
888 | this.getEnpassantCaptures([x, y], pawnShiftX) | |
889 | ); | |
1c9f093d | 890 | } |
294fe29f | 891 | |
32f6285e | 892 | return pMoves; |
1c9f093d BA |
893 | } |
894 | ||
895 | // What are the rook moves from square x,y ? | |
6808d7a1 | 896 | getPotentialRookMoves(sq) { |
1c9f093d BA |
897 | return this.getSlideNJumpMoves(sq, V.steps[V.ROOK]); |
898 | } | |
899 | ||
900 | // What are the knight moves from square x,y ? | |
6808d7a1 | 901 | getPotentialKnightMoves(sq) { |
4313762d | 902 | return this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], 1); |
1c9f093d BA |
903 | } |
904 | ||
905 | // What are the bishop moves from square x,y ? | |
6808d7a1 | 906 | getPotentialBishopMoves(sq) { |
1c9f093d BA |
907 | return this.getSlideNJumpMoves(sq, V.steps[V.BISHOP]); |
908 | } | |
909 | ||
910 | // What are the queen moves from square x,y ? | |
6808d7a1 BA |
911 | getPotentialQueenMoves(sq) { |
912 | return this.getSlideNJumpMoves( | |
4313762d | 913 | sq, V.steps[V.ROOK].concat(V.steps[V.BISHOP])); |
1c9f093d BA |
914 | } |
915 | ||
916 | // What are the king moves from square x,y ? | |
6808d7a1 | 917 | getPotentialKingMoves(sq) { |
1c9f093d | 918 | // Initialize with normal moves |
c583ef1c | 919 | let moves = this.getSlideNJumpMoves( |
4313762d | 920 | sq, V.steps[V.ROOK].concat(V.steps[V.BISHOP]), 1); |
7e8a7ea1 BA |
921 | if (V.HasCastle && this.castleFlags[this.turn].some(v => v < V.size.y)) |
922 | moves = moves.concat(this.getCastleMoves(sq)); | |
c583ef1c | 923 | return moves; |
1c9f093d BA |
924 | } |
925 | ||
a6836242 | 926 | // "castleInCheck" arg to let some variants castle under check |
7e8a7ea1 | 927 | getCastleMoves([x, y], finalSquares, castleInCheck, castleWith) { |
6808d7a1 | 928 | const c = this.getColor(x, y); |
1c9f093d BA |
929 | |
930 | // Castling ? | |
931 | const oppCol = V.GetOppCol(c); | |
932 | let moves = []; | |
9bd6786b | 933 | // King, then rook: |
7e8a7ea1 BA |
934 | finalSquares = finalSquares || [ [2, 3], [V.size.y - 2, V.size.y - 3] ]; |
935 | const castlingKing = this.board[x][y].charAt(1); | |
6808d7a1 BA |
936 | castlingCheck: for ( |
937 | let castleSide = 0; | |
938 | castleSide < 2; | |
939 | castleSide++ //large, then small | |
940 | ) { | |
3a2a7b5f | 941 | if (this.castleFlags[c][castleSide] >= V.size.y) continue; |
3f22c2c3 | 942 | // If this code is reached, rook and king are on initial position |
1c9f093d | 943 | |
2c5d7b20 | 944 | // NOTE: in some variants this is not a rook |
32f6285e | 945 | const rookPos = this.castleFlags[c][castleSide]; |
7e8a7ea1 | 946 | const castlingPiece = this.board[x][rookPos].charAt(1); |
85a1dcba BA |
947 | if ( |
948 | this.board[x][rookPos] == V.EMPTY || | |
949 | this.getColor(x, rookPos) != c || | |
7e8a7ea1 | 950 | (!!castleWith && !castleWith.includes(castlingPiece)) |
85a1dcba | 951 | ) { |
61656127 | 952 | // Rook is not here, or changed color (see Benedict) |
32f6285e | 953 | continue; |
85a1dcba | 954 | } |
32f6285e | 955 | |
2beba6db BA |
956 | // Nothing on the path of the king ? (and no checks) |
957 | const finDist = finalSquares[castleSide][0] - y; | |
958 | let step = finDist / Math.max(1, Math.abs(finDist)); | |
059f0aa2 | 959 | let i = y; |
6808d7a1 BA |
960 | do { |
961 | if ( | |
7e8a7ea1 BA |
962 | (!castleInCheck && this.isAttacked([x, i], oppCol)) || |
963 | ( | |
964 | this.board[x][i] != V.EMPTY && | |
6808d7a1 | 965 | // NOTE: next check is enough, because of chessboard constraints |
7e8a7ea1 BA |
966 | (this.getColor(x, i) != c || ![y, rookPos].includes(i)) |
967 | ) | |
6808d7a1 | 968 | ) { |
1c9f093d BA |
969 | continue castlingCheck; |
970 | } | |
2beba6db | 971 | i += step; |
6808d7a1 | 972 | } while (i != finalSquares[castleSide][0]); |
1c9f093d BA |
973 | |
974 | // Nothing on the path to the rook? | |
6808d7a1 | 975 | step = castleSide == 0 ? -1 : 1; |
3a2a7b5f | 976 | for (i = y + step; i != rookPos; i += step) { |
6808d7a1 | 977 | if (this.board[x][i] != V.EMPTY) continue castlingCheck; |
1c9f093d | 978 | } |
1c9f093d BA |
979 | |
980 | // Nothing on final squares, except maybe king and castling rook? | |
6808d7a1 BA |
981 | for (i = 0; i < 2; i++) { |
982 | if ( | |
5e1bc651 | 983 | finalSquares[castleSide][i] != rookPos && |
6808d7a1 | 984 | this.board[x][finalSquares[castleSide][i]] != V.EMPTY && |
5e1bc651 | 985 | ( |
7e8a7ea1 | 986 | finalSquares[castleSide][i] != y || |
5e1bc651 BA |
987 | this.getColor(x, finalSquares[castleSide][i]) != c |
988 | ) | |
6808d7a1 | 989 | ) { |
1c9f093d BA |
990 | continue castlingCheck; |
991 | } | |
992 | } | |
993 | ||
994 | // If this code is reached, castle is valid | |
6808d7a1 BA |
995 | moves.push( |
996 | new Move({ | |
997 | appear: [ | |
2c5d7b20 BA |
998 | new PiPo({ |
999 | x: x, | |
1000 | y: finalSquares[castleSide][0], | |
7e8a7ea1 | 1001 | p: castlingKing, |
2c5d7b20 BA |
1002 | c: c |
1003 | }), | |
1004 | new PiPo({ | |
1005 | x: x, | |
1006 | y: finalSquares[castleSide][1], | |
1007 | p: castlingPiece, | |
1008 | c: c | |
1009 | }) | |
6808d7a1 BA |
1010 | ], |
1011 | vanish: [ | |
7e8a7ea1 | 1012 | // King might be initially disguised (Titan...) |
a19caec0 | 1013 | new PiPo({ x: x, y: y, p: castlingKing, c: c }), |
a6836242 | 1014 | new PiPo({ x: x, y: rookPos, p: castlingPiece, c: c }) |
6808d7a1 BA |
1015 | ], |
1016 | end: | |
1017 | Math.abs(y - rookPos) <= 2 | |
1018 | ? { x: x, y: rookPos } | |
1019 | : { x: x, y: y + 2 * (castleSide == 0 ? -1 : 1) } | |
1020 | }) | |
1021 | ); | |
1c9f093d BA |
1022 | } |
1023 | ||
1024 | return moves; | |
1025 | } | |
1026 | ||
1027 | //////////////////// | |
1028 | // MOVES VALIDATION | |
1029 | ||
1030 | // For the interface: possible moves for the current turn from square sq | |
6808d7a1 BA |
1031 | getPossibleMovesFrom(sq) { |
1032 | return this.filterValid(this.getPotentialMovesFrom(sq)); | |
1c9f093d BA |
1033 | } |
1034 | ||
1035 | // TODO: promotions (into R,B,N,Q) should be filtered only once | |
6808d7a1 BA |
1036 | filterValid(moves) { |
1037 | if (moves.length == 0) return []; | |
1c9f093d BA |
1038 | const color = this.turn; |
1039 | return moves.filter(m => { | |
1040 | this.play(m); | |
1041 | const res = !this.underCheck(color); | |
1042 | this.undo(m); | |
1043 | return res; | |
1044 | }); | |
1045 | } | |
1046 | ||
5e1bc651 | 1047 | getAllPotentialMoves() { |
1c9f093d | 1048 | const color = this.turn; |
1c9f093d | 1049 | let potentialMoves = []; |
6808d7a1 BA |
1050 | for (let i = 0; i < V.size.x; i++) { |
1051 | for (let j = 0; j < V.size.y; j++) { | |
156986e6 | 1052 | if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == color) { |
6808d7a1 BA |
1053 | Array.prototype.push.apply( |
1054 | potentialMoves, | |
1055 | this.getPotentialMovesFrom([i, j]) | |
1056 | ); | |
1c9f093d BA |
1057 | } |
1058 | } | |
1059 | } | |
5e1bc651 BA |
1060 | return potentialMoves; |
1061 | } | |
1062 | ||
1063 | // Search for all valid moves considering current turn | |
1064 | // (for engine and game end) | |
1065 | getAllValidMoves() { | |
1066 | return this.filterValid(this.getAllPotentialMoves()); | |
1c9f093d BA |
1067 | } |
1068 | ||
1069 | // Stop at the first move found | |
2c5d7b20 | 1070 | // TODO: not really, it explores all moves from a square (one is enough). |
cdab5663 BA |
1071 | // Possible fix: add extra arg "oneMove" to getPotentialMovesFrom, |
1072 | // and then return only boolean true at first move found | |
1073 | // (in all getPotentialXXXMoves() ... for all variants ...) | |
6808d7a1 | 1074 | atLeastOneMove() { |
1c9f093d | 1075 | const color = this.turn; |
6808d7a1 BA |
1076 | for (let i = 0; i < V.size.x; i++) { |
1077 | for (let j = 0; j < V.size.y; j++) { | |
665eed90 | 1078 | if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == color) { |
6808d7a1 BA |
1079 | const moves = this.getPotentialMovesFrom([i, j]); |
1080 | if (moves.length > 0) { | |
107dc1bd | 1081 | for (let k = 0; k < moves.length; k++) |
6808d7a1 | 1082 | if (this.filterValid([moves[k]]).length > 0) return true; |
1c9f093d BA |
1083 | } |
1084 | } | |
1085 | } | |
1086 | } | |
1087 | return false; | |
1088 | } | |
1089 | ||
68e19a44 BA |
1090 | // Check if pieces of given color are attacking (king) on square x,y |
1091 | isAttacked(sq, color) { | |
6808d7a1 | 1092 | return ( |
68e19a44 BA |
1093 | this.isAttackedByPawn(sq, color) || |
1094 | this.isAttackedByRook(sq, color) || | |
1095 | this.isAttackedByKnight(sq, color) || | |
1096 | this.isAttackedByBishop(sq, color) || | |
1097 | this.isAttackedByQueen(sq, color) || | |
1098 | this.isAttackedByKing(sq, color) | |
6808d7a1 | 1099 | ); |
1c9f093d BA |
1100 | } |
1101 | ||
d1be8046 | 1102 | // Generic method for non-pawn pieces ("sliding or jumping"): |
68e19a44 | 1103 | // is x,y attacked by a piece of given color ? |
4313762d | 1104 | isAttackedBySlideNJump([x, y], color, piece, steps, nbSteps) { |
d1be8046 BA |
1105 | for (let step of steps) { |
1106 | let rx = x + step[0], | |
1107 | ry = y + step[1]; | |
4313762d BA |
1108 | let stepCounter = 1; |
1109 | while ( | |
1110 | V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && | |
1111 | (!nbSteps || stepCounter < nbSteps) | |
1112 | ) { | |
d1be8046 BA |
1113 | rx += step[0]; |
1114 | ry += step[1]; | |
4313762d | 1115 | stepCounter++; |
d1be8046 BA |
1116 | } |
1117 | if ( | |
1118 | V.OnBoard(rx, ry) && | |
3cf54395 | 1119 | this.board[rx][ry] != V.EMPTY && |
68e19a44 | 1120 | this.getPiece(rx, ry) == piece && |
da9e846e | 1121 | this.getColor(rx, ry) == color |
d1be8046 BA |
1122 | ) { |
1123 | return true; | |
1124 | } | |
1125 | } | |
1126 | return false; | |
1127 | } | |
1128 | ||
68e19a44 | 1129 | // Is square x,y attacked by 'color' pawns ? |
107dc1bd | 1130 | isAttackedByPawn(sq, color) { |
68e19a44 | 1131 | const pawnShift = (color == "w" ? 1 : -1); |
107dc1bd BA |
1132 | return this.isAttackedBySlideNJump( |
1133 | sq, | |
1134 | color, | |
1135 | V.PAWN, | |
1136 | [[pawnShift, 1], [pawnShift, -1]], | |
1137 | "oneStep" | |
1138 | ); | |
1c9f093d BA |
1139 | } |
1140 | ||
68e19a44 BA |
1141 | // Is square x,y attacked by 'color' rooks ? |
1142 | isAttackedByRook(sq, color) { | |
1143 | return this.isAttackedBySlideNJump(sq, color, V.ROOK, V.steps[V.ROOK]); | |
1c9f093d BA |
1144 | } |
1145 | ||
68e19a44 BA |
1146 | // Is square x,y attacked by 'color' knights ? |
1147 | isAttackedByKnight(sq, color) { | |
6808d7a1 BA |
1148 | return this.isAttackedBySlideNJump( |
1149 | sq, | |
68e19a44 | 1150 | color, |
6808d7a1 BA |
1151 | V.KNIGHT, |
1152 | V.steps[V.KNIGHT], | |
1153 | "oneStep" | |
1154 | ); | |
1c9f093d BA |
1155 | } |
1156 | ||
68e19a44 BA |
1157 | // Is square x,y attacked by 'color' bishops ? |
1158 | isAttackedByBishop(sq, color) { | |
1159 | return this.isAttackedBySlideNJump(sq, color, V.BISHOP, V.steps[V.BISHOP]); | |
1c9f093d BA |
1160 | } |
1161 | ||
68e19a44 BA |
1162 | // Is square x,y attacked by 'color' queens ? |
1163 | isAttackedByQueen(sq, color) { | |
6808d7a1 BA |
1164 | return this.isAttackedBySlideNJump( |
1165 | sq, | |
68e19a44 | 1166 | color, |
6808d7a1 BA |
1167 | V.QUEEN, |
1168 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]) | |
1169 | ); | |
1c9f093d BA |
1170 | } |
1171 | ||
68e19a44 BA |
1172 | // Is square x,y attacked by 'color' king(s) ? |
1173 | isAttackedByKing(sq, color) { | |
6808d7a1 BA |
1174 | return this.isAttackedBySlideNJump( |
1175 | sq, | |
68e19a44 | 1176 | color, |
6808d7a1 BA |
1177 | V.KING, |
1178 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), | |
1179 | "oneStep" | |
1180 | ); | |
1c9f093d BA |
1181 | } |
1182 | ||
1c9f093d | 1183 | // Is color under check after his move ? |
6808d7a1 | 1184 | underCheck(color) { |
1c58eb76 | 1185 | return this.isAttacked(this.kingPos[color], V.GetOppCol(color)); |
1c9f093d BA |
1186 | } |
1187 | ||
1188 | ///////////////// | |
1189 | // MOVES PLAYING | |
1190 | ||
1191 | // Apply a move on board | |
6808d7a1 BA |
1192 | static PlayOnBoard(board, move) { |
1193 | for (let psq of move.vanish) board[psq.x][psq.y] = V.EMPTY; | |
1194 | for (let psq of move.appear) board[psq.x][psq.y] = psq.c + psq.p; | |
1c9f093d BA |
1195 | } |
1196 | // Un-apply the played move | |
6808d7a1 BA |
1197 | static UndoOnBoard(board, move) { |
1198 | for (let psq of move.appear) board[psq.x][psq.y] = V.EMPTY; | |
1199 | for (let psq of move.vanish) board[psq.x][psq.y] = psq.c + psq.p; | |
1c9f093d BA |
1200 | } |
1201 | ||
3a2a7b5f BA |
1202 | prePlay() {} |
1203 | ||
1204 | play(move) { | |
1205 | // DEBUG: | |
1206 | // if (!this.states) this.states = []; | |
1c58eb76 | 1207 | // const stateFen = this.getFen() + JSON.stringify(this.kingPos); |
3a2a7b5f BA |
1208 | // this.states.push(stateFen); |
1209 | ||
1210 | this.prePlay(move); | |
2c5d7b20 BA |
1211 | // Save flags (for undo) |
1212 | if (V.HasFlags) move.flags = JSON.stringify(this.aggregateFlags()); | |
3a2a7b5f BA |
1213 | if (V.HasEnpassant) this.epSquares.push(this.getEpSquare(move)); |
1214 | V.PlayOnBoard(this.board, move); | |
1215 | this.turn = V.GetOppCol(this.turn); | |
1216 | this.movesCount++; | |
1217 | this.postPlay(move); | |
1218 | } | |
1219 | ||
a9e1202b | 1220 | updateCastleFlags(move, piece, color) { |
4258b58c | 1221 | // TODO: check flags. If already off, no need to always re-evaluate |
a9e1202b | 1222 | const c = color || V.GetOppCol(this.turn); |
1c58eb76 BA |
1223 | const firstRank = (c == "w" ? V.size.x - 1 : 0); |
1224 | // Update castling flags if rooks are moved | |
c7550017 | 1225 | const oppCol = this.turn; |
1c58eb76 | 1226 | const oppFirstRank = V.size.x - 1 - firstRank; |
bb688df5 BA |
1227 | if (piece == V.KING && move.appear.length > 0) |
1228 | this.castleFlags[c] = [V.size.y, V.size.y]; | |
1229 | else if ( | |
1c58eb76 BA |
1230 | move.start.x == firstRank && //our rook moves? |
1231 | this.castleFlags[c].includes(move.start.y) | |
1232 | ) { | |
1233 | const flagIdx = (move.start.y == this.castleFlags[c][0] ? 0 : 1); | |
1234 | this.castleFlags[c][flagIdx] = V.size.y; | |
305ede7e BA |
1235 | } |
1236 | // NOTE: not "else if" because a rook could take an opposing rook | |
1237 | if ( | |
1c58eb76 BA |
1238 | move.end.x == oppFirstRank && //we took opponent rook? |
1239 | this.castleFlags[oppCol].includes(move.end.y) | |
1240 | ) { | |
1241 | const flagIdx = (move.end.y == this.castleFlags[oppCol][0] ? 0 : 1); | |
1242 | this.castleFlags[oppCol][flagIdx] = V.size.y; | |
1243 | } | |
1244 | } | |
1245 | ||
1c9f093d | 1246 | // After move is played, update variables + flags |
3a2a7b5f BA |
1247 | postPlay(move) { |
1248 | const c = V.GetOppCol(this.turn); | |
1c9f093d | 1249 | let piece = undefined; |
3a2a7b5f | 1250 | if (move.vanish.length >= 1) |
1c9f093d BA |
1251 | // Usual case, something is moved |
1252 | piece = move.vanish[0].p; | |
3a2a7b5f | 1253 | else |
1c9f093d BA |
1254 | // Crazyhouse-like variants |
1255 | piece = move.appear[0].p; | |
1c9f093d BA |
1256 | |
1257 | // Update king position + flags | |
964eda04 BA |
1258 | if (piece == V.KING && move.appear.length > 0) |
1259 | this.kingPos[c] = [move.appear[0].x, move.appear[0].y]; | |
bb688df5 | 1260 | if (V.HasCastle) this.updateCastleFlags(move, piece); |
1c9f093d BA |
1261 | } |
1262 | ||
3a2a7b5f | 1263 | preUndo() {} |
1c9f093d | 1264 | |
6808d7a1 | 1265 | undo(move) { |
3a2a7b5f | 1266 | this.preUndo(move); |
6808d7a1 BA |
1267 | if (V.HasEnpassant) this.epSquares.pop(); |
1268 | if (V.HasFlags) this.disaggregateFlags(JSON.parse(move.flags)); | |
1c9f093d BA |
1269 | V.UndoOnBoard(this.board, move); |
1270 | this.turn = V.GetOppCol(this.turn); | |
1271 | this.movesCount--; | |
3a2a7b5f | 1272 | this.postUndo(move); |
1c9f093d BA |
1273 | |
1274 | // DEBUG: | |
1c58eb76 | 1275 | // const stateFen = this.getFen() + JSON.stringify(this.kingPos); |
9bd6786b BA |
1276 | // if (stateFen != this.states[this.states.length-1]) debugger; |
1277 | // this.states.pop(); | |
1c9f093d BA |
1278 | } |
1279 | ||
3a2a7b5f BA |
1280 | // After move is undo-ed *and flags resetted*, un-update other variables |
1281 | // TODO: more symmetry, by storing flags increment in move (?!) | |
1282 | postUndo(move) { | |
1283 | // (Potentially) Reset king position | |
1284 | const c = this.getColor(move.start.x, move.start.y); | |
1285 | if (this.getPiece(move.start.x, move.start.y) == V.KING) | |
1286 | this.kingPos[c] = [move.start.x, move.start.y]; | |
1287 | } | |
1288 | ||
1c9f093d BA |
1289 | /////////////// |
1290 | // END OF GAME | |
1291 | ||
1292 | // What is the score ? (Interesting if game is over) | |
6808d7a1 | 1293 | getCurrentScore() { |
bb688df5 | 1294 | if (this.atLeastOneMove()) return "*"; |
1c9f093d BA |
1295 | // Game over |
1296 | const color = this.turn; | |
1297 | // No valid move: stalemate or checkmate? | |
bb688df5 | 1298 | if (!this.underCheck(color)) return "1/2"; |
1c9f093d | 1299 | // OK, checkmate |
68e19a44 | 1300 | return (color == "w" ? "0-1" : "1-0"); |
1c9f093d BA |
1301 | } |
1302 | ||
1303 | /////////////// | |
1304 | // ENGINE PLAY | |
1305 | ||
1306 | // Pieces values | |
6808d7a1 | 1307 | static get VALUES() { |
1c9f093d | 1308 | return { |
6808d7a1 BA |
1309 | p: 1, |
1310 | r: 5, | |
1311 | n: 3, | |
1312 | b: 3, | |
1313 | q: 9, | |
1314 | k: 1000 | |
1c9f093d BA |
1315 | }; |
1316 | } | |
1317 | ||
1318 | // "Checkmate" (unreachable eval) | |
6808d7a1 BA |
1319 | static get INFINITY() { |
1320 | return 9999; | |
1321 | } | |
1c9f093d BA |
1322 | |
1323 | // At this value or above, the game is over | |
6808d7a1 BA |
1324 | static get THRESHOLD_MATE() { |
1325 | return V.INFINITY; | |
1326 | } | |
1c9f093d | 1327 | |
2c5d7b20 | 1328 | // Search depth: 1,2 for e.g. higher branching factor, 4 for smaller |
6808d7a1 BA |
1329 | static get SEARCH_DEPTH() { |
1330 | return 3; | |
1331 | } | |
1c9f093d | 1332 | |
af34341d BA |
1333 | // 'movesList' arg for some variants to provide a custom list |
1334 | getComputerMove(movesList) { | |
1c9f093d BA |
1335 | const maxeval = V.INFINITY; |
1336 | const color = this.turn; | |
af34341d | 1337 | let moves1 = movesList || this.getAllValidMoves(); |
c322a844 | 1338 | |
6808d7a1 | 1339 | if (moves1.length == 0) |
e71161fb | 1340 | // TODO: this situation should not happen |
41cb9b94 | 1341 | return null; |
1c9f093d | 1342 | |
b83a675a | 1343 | // Rank moves using a min-max at depth 2 (if search_depth >= 2!) |
6808d7a1 | 1344 | for (let i = 0; i < moves1.length; i++) { |
afbf3ca7 BA |
1345 | this.play(moves1[i]); |
1346 | const score1 = this.getCurrentScore(); | |
1347 | if (score1 != "*") { | |
1348 | moves1[i].eval = | |
1349 | score1 == "1/2" | |
1350 | ? 0 | |
1351 | : (score1 == "1-0" ? 1 : -1) * maxeval; | |
1352 | } | |
1353 | if (V.SEARCH_DEPTH == 1 || score1 != "*") { | |
1354 | if (!moves1[i].eval) moves1[i].eval = this.evalPosition(); | |
1355 | this.undo(moves1[i]); | |
b83a675a BA |
1356 | continue; |
1357 | } | |
1c9f093d | 1358 | // Initial self evaluation is very low: "I'm checkmated" |
6808d7a1 | 1359 | moves1[i].eval = (color == "w" ? -1 : 1) * maxeval; |
afbf3ca7 BA |
1360 | // Initial enemy evaluation is very low too, for him |
1361 | let eval2 = (color == "w" ? 1 : -1) * maxeval; | |
1362 | // Second half-move: | |
1363 | let moves2 = this.getAllValidMoves(); | |
1364 | for (let j = 0; j < moves2.length; j++) { | |
1365 | this.play(moves2[j]); | |
1366 | const score2 = this.getCurrentScore(); | |
1367 | let evalPos = 0; //1/2 value | |
1368 | switch (score2) { | |
1369 | case "*": | |
1370 | evalPos = this.evalPosition(); | |
1371 | break; | |
1372 | case "1-0": | |
1373 | evalPos = maxeval; | |
1374 | break; | |
1375 | case "0-1": | |
1376 | evalPos = -maxeval; | |
1377 | break; | |
1c9f093d | 1378 | } |
afbf3ca7 BA |
1379 | if ( |
1380 | (color == "w" && evalPos < eval2) || | |
1381 | (color == "b" && evalPos > eval2) | |
1382 | ) { | |
1383 | eval2 = evalPos; | |
1384 | } | |
1385 | this.undo(moves2[j]); | |
1386 | } | |
6808d7a1 BA |
1387 | if ( |
1388 | (color == "w" && eval2 > moves1[i].eval) || | |
1389 | (color == "b" && eval2 < moves1[i].eval) | |
1390 | ) { | |
1c9f093d BA |
1391 | moves1[i].eval = eval2; |
1392 | } | |
1393 | this.undo(moves1[i]); | |
1394 | } | |
6808d7a1 BA |
1395 | moves1.sort((a, b) => { |
1396 | return (color == "w" ? 1 : -1) * (b.eval - a.eval); | |
1397 | }); | |
a97bdbda | 1398 | // console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; })); |
1c9f093d | 1399 | |
1c9f093d | 1400 | // Skip depth 3+ if we found a checkmate (or if we are checkmated in 1...) |
6808d7a1 | 1401 | if (V.SEARCH_DEPTH >= 3 && Math.abs(moves1[0].eval) < V.THRESHOLD_MATE) { |
6808d7a1 | 1402 | for (let i = 0; i < moves1.length; i++) { |
1c9f093d BA |
1403 | this.play(moves1[i]); |
1404 | // 0.1 * oldEval : heuristic to avoid some bad moves (not all...) | |
6808d7a1 BA |
1405 | moves1[i].eval = |
1406 | 0.1 * moves1[i].eval + | |
1407 | this.alphabeta(V.SEARCH_DEPTH - 1, -maxeval, maxeval); | |
1c9f093d BA |
1408 | this.undo(moves1[i]); |
1409 | } | |
6808d7a1 BA |
1410 | moves1.sort((a, b) => { |
1411 | return (color == "w" ? 1 : -1) * (b.eval - a.eval); | |
1412 | }); | |
b83a675a | 1413 | } |
1c9f093d | 1414 | |
b83a675a | 1415 | let candidates = [0]; |
d54f6261 BA |
1416 | for (let i = 1; i < moves1.length && moves1[i].eval == moves1[0].eval; i++) |
1417 | candidates.push(i); | |
656b1878 | 1418 | return moves1[candidates[randInt(candidates.length)]]; |
1c9f093d BA |
1419 | } |
1420 | ||
6808d7a1 | 1421 | alphabeta(depth, alpha, beta) { |
1c9f093d BA |
1422 | const maxeval = V.INFINITY; |
1423 | const color = this.turn; | |
1424 | const score = this.getCurrentScore(); | |
1425 | if (score != "*") | |
6808d7a1 BA |
1426 | return score == "1/2" ? 0 : (score == "1-0" ? 1 : -1) * maxeval; |
1427 | if (depth == 0) return this.evalPosition(); | |
a97bdbda | 1428 | const moves = this.getAllValidMoves(); |
6808d7a1 BA |
1429 | let v = color == "w" ? -maxeval : maxeval; |
1430 | if (color == "w") { | |
1431 | for (let i = 0; i < moves.length; i++) { | |
1c9f093d | 1432 | this.play(moves[i]); |
6808d7a1 | 1433 | v = Math.max(v, this.alphabeta(depth - 1, alpha, beta)); |
1c9f093d BA |
1434 | this.undo(moves[i]); |
1435 | alpha = Math.max(alpha, v); | |
6808d7a1 | 1436 | if (alpha >= beta) break; //beta cutoff |
1c9f093d | 1437 | } |
1c5bfdf2 | 1438 | } |
6808d7a1 | 1439 | else { |
1c5bfdf2 | 1440 | // color=="b" |
6808d7a1 | 1441 | for (let i = 0; i < moves.length; i++) { |
1c9f093d | 1442 | this.play(moves[i]); |
6808d7a1 | 1443 | v = Math.min(v, this.alphabeta(depth - 1, alpha, beta)); |
1c9f093d BA |
1444 | this.undo(moves[i]); |
1445 | beta = Math.min(beta, v); | |
6808d7a1 | 1446 | if (alpha >= beta) break; //alpha cutoff |
1c9f093d BA |
1447 | } |
1448 | } | |
1449 | return v; | |
1450 | } | |
1451 | ||
6808d7a1 | 1452 | evalPosition() { |
1c9f093d BA |
1453 | let evaluation = 0; |
1454 | // Just count material for now | |
6808d7a1 BA |
1455 | for (let i = 0; i < V.size.x; i++) { |
1456 | for (let j = 0; j < V.size.y; j++) { | |
1457 | if (this.board[i][j] != V.EMPTY) { | |
1458 | const sign = this.getColor(i, j) == "w" ? 1 : -1; | |
1459 | evaluation += sign * V.VALUES[this.getPiece(i, j)]; | |
1c9f093d BA |
1460 | } |
1461 | } | |
1462 | } | |
1463 | return evaluation; | |
1464 | } | |
1465 | ||
1466 | ///////////////////////// | |
1467 | // MOVES + GAME NOTATION | |
1468 | ///////////////////////// | |
1469 | ||
1470 | // Context: just before move is played, turn hasn't changed | |
1471 | // TODO: un-ambiguous notation (switch on piece type, check directions...) | |
6808d7a1 BA |
1472 | getNotation(move) { |
1473 | if (move.appear.length == 2 && move.appear[0].p == V.KING) | |
1cd3e362 | 1474 | // Castle |
6808d7a1 | 1475 | return move.end.y < move.start.y ? "0-0-0" : "0-0"; |
1c9f093d BA |
1476 | |
1477 | // Translate final square | |
1478 | const finalSquare = V.CoordsToSquare(move.end); | |
1479 | ||
1480 | const piece = this.getPiece(move.start.x, move.start.y); | |
6808d7a1 | 1481 | if (piece == V.PAWN) { |
1c9f093d BA |
1482 | // Pawn move |
1483 | let notation = ""; | |
6808d7a1 | 1484 | if (move.vanish.length > move.appear.length) { |
1c9f093d BA |
1485 | // Capture |
1486 | const startColumn = V.CoordToColumn(move.start.y); | |
1487 | notation = startColumn + "x" + finalSquare; | |
78d64531 | 1488 | } |
6808d7a1 BA |
1489 | else notation = finalSquare; |
1490 | if (move.appear.length > 0 && move.appear[0].p != V.PAWN) | |
78d64531 | 1491 | // Promotion |
1c9f093d BA |
1492 | notation += "=" + move.appear[0].p.toUpperCase(); |
1493 | return notation; | |
1494 | } | |
6808d7a1 BA |
1495 | // Piece movement |
1496 | return ( | |
1497 | piece.toUpperCase() + | |
1498 | (move.vanish.length > move.appear.length ? "x" : "") + | |
1499 | finalSquare | |
1500 | ); | |
1501 | } | |
2c5d7b20 BA |
1502 | |
1503 | static GetUnambiguousNotation(move) { | |
1504 | // Machine-readable format with all the informations about the move | |
1505 | return ( | |
1506 | (!!move.start && V.OnBoard(move.start.x, move.start.y) | |
1507 | ? V.CoordsToSquare(move.start) | |
1508 | : "-" | |
1509 | ) + "." + | |
1510 | (!!move.end && V.OnBoard(move.end.x, move.end.y) | |
1511 | ? V.CoordsToSquare(move.end) | |
1512 | : "-" | |
1513 | ) + " " + | |
1514 | (!!move.appear && move.appear.length > 0 | |
1515 | ? move.appear.map(a => | |
1516 | a.c + a.p + V.CoordsToSquare({ x: a.x, y: a.y })).join(".") | |
1517 | : "-" | |
1518 | ) + "/" + | |
1519 | (!!move.vanish && move.vanish.length > 0 | |
1520 | ? move.vanish.map(a => | |
1521 | a.c + a.p + V.CoordsToSquare({ x: a.x, y: a.y })).join(".") | |
1522 | : "-" | |
1523 | ) | |
1524 | ); | |
1525 | } | |
7e8a7ea1 | 1526 | |
6808d7a1 | 1527 | }; |