Commit | Line | Data |
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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 | ||
1d184b4c BA |
4 | class PiPo //Piece+Position |
5 | { | |
6 | // o: {piece[p], color[c], posX[x], posY[y]} | |
7 | constructor(o) | |
8 | { | |
9 | this.p = o.p; | |
10 | this.c = o.c; | |
11 | this.x = o.x; | |
12 | this.y = o.y; | |
13 | } | |
14 | } | |
15 | ||
098e8468 | 16 | // TODO: for animation, moves should contains "moving" and "fading" maybe... |
1d184b4c BA |
17 | class Move |
18 | { | |
19 | // o: {appear, vanish, [start,] [end,]} | |
20 | // appear,vanish = arrays of PiPo | |
21 | // start,end = coordinates to apply to trigger move visually (think castle) | |
22 | constructor(o) | |
23 | { | |
24 | this.appear = o.appear; | |
25 | this.vanish = o.vanish; | |
26 | this.start = !!o.start ? o.start : {x:o.vanish[0].x, y:o.vanish[0].y}; | |
27 | this.end = !!o.end ? o.end : {x:o.appear[0].x, y:o.appear[0].y}; | |
28 | } | |
29 | } | |
30 | ||
31 | // NOTE: x coords = top to bottom; y = left to right (from white player perspective) | |
32 | class ChessRules | |
33 | { | |
34 | // Path to pieces | |
35 | static getPpath(b) | |
36 | { | |
37 | return b; //usual pieces in pieces/ folder | |
38 | } | |
39 | // Turn "wb" into "B" (for FEN) | |
40 | static board2fen(b) | |
41 | { | |
42 | return b[0]=='w' ? b[1].toUpperCase() : b[1]; | |
43 | } | |
44 | // Turn "p" into "bp" (for board) | |
45 | static fen2board(f) | |
46 | { | |
47 | return f.charCodeAt()<=90 ? "w"+f.toLowerCase() : "b"+f; | |
48 | } | |
49 | ||
50 | ///////////////// | |
51 | // INITIALIZATION | |
52 | ||
d3334c3a | 53 | // fen == "position flags" |
dfb4afc1 | 54 | constructor(fen, moves) |
1d184b4c | 55 | { |
dfb4afc1 | 56 | this.moves = moves; |
331fc58c | 57 | this.hashStates = {}; //for repetitions detection |
1d184b4c | 58 | // Use fen string to initialize variables, flags and board |
1d184b4c | 59 | this.board = VariantRules.GetBoard(fen); |
2526c041 | 60 | this.setFlags(fen); |
ffbae57a | 61 | this.initVariables(fen); |
1d184b4c BA |
62 | } |
63 | ||
64 | initVariables(fen) | |
65 | { | |
66 | this.INIT_COL_KING = {'w':-1, 'b':-1}; | |
67 | this.INIT_COL_ROOK = {'w':[-1,-1], 'b':[-1,-1]}; | |
92342261 | 68 | this.kingPos = {'w':[-1,-1], 'b':[-1,-1]}; //squares of white and black king |
1d184b4c BA |
69 | const fenParts = fen.split(" "); |
70 | const position = fenParts[0].split("/"); | |
71 | for (let i=0; i<position.length; i++) | |
72 | { | |
6037f1d8 BA |
73 | let k = 0; //column index on board |
74 | for (let j=0; j<position[i].length; j++) | |
1d184b4c BA |
75 | { |
76 | switch (position[i].charAt(j)) | |
77 | { | |
78 | case 'k': | |
6037f1d8 BA |
79 | this.kingPos['b'] = [i,k]; |
80 | this.INIT_COL_KING['b'] = k; | |
1d184b4c BA |
81 | break; |
82 | case 'K': | |
6037f1d8 BA |
83 | this.kingPos['w'] = [i,k]; |
84 | this.INIT_COL_KING['w'] = k; | |
1d184b4c BA |
85 | break; |
86 | case 'r': | |
87 | if (this.INIT_COL_ROOK['b'][0] < 0) | |
6037f1d8 | 88 | this.INIT_COL_ROOK['b'][0] = k; |
1d184b4c | 89 | else |
6037f1d8 | 90 | this.INIT_COL_ROOK['b'][1] = k; |
1d184b4c BA |
91 | break; |
92 | case 'R': | |
93 | if (this.INIT_COL_ROOK['w'][0] < 0) | |
6037f1d8 | 94 | this.INIT_COL_ROOK['w'][0] = k; |
1d184b4c | 95 | else |
6037f1d8 | 96 | this.INIT_COL_ROOK['w'][1] = k; |
1d184b4c BA |
97 | break; |
98 | default: | |
99 | let num = parseInt(position[i].charAt(j)); | |
100 | if (!isNaN(num)) | |
6037f1d8 | 101 | k += (num-1); |
1d184b4c | 102 | } |
6037f1d8 | 103 | k++; |
1d184b4c BA |
104 | } |
105 | } | |
f3802fcd | 106 | const epSq = this.moves.length > 0 ? this.getEpSquare(this.lastMove) : undefined; |
1d184b4c | 107 | this.epSquares = [ epSq ]; |
1d184b4c BA |
108 | } |
109 | ||
110 | // Turn diagram fen into double array ["wb","wp","bk",...] | |
111 | static GetBoard(fen) | |
112 | { | |
113 | let rows = fen.split(" ")[0].split("/"); | |
46302e64 | 114 | const [sizeX,sizeY] = VariantRules.size; |
1d184b4c BA |
115 | let board = doubleArray(sizeX, sizeY, ""); |
116 | for (let i=0; i<rows.length; i++) | |
117 | { | |
118 | let j = 0; | |
119 | for (let indexInRow = 0; indexInRow < rows[i].length; indexInRow++) | |
120 | { | |
121 | let character = rows[i][indexInRow]; | |
122 | let num = parseInt(character); | |
123 | if (!isNaN(num)) | |
124 | j += num; //just shift j | |
125 | else //something at position i,j | |
126 | board[i][j++] = VariantRules.fen2board(character); | |
127 | } | |
128 | } | |
129 | return board; | |
130 | } | |
131 | ||
dda21a71 | 132 | // Extract (relevant) flags from fen |
2526c041 | 133 | setFlags(fen) |
1d184b4c BA |
134 | { |
135 | // white a-castle, h-castle, black a-castle, h-castle | |
2526c041 BA |
136 | this.castleFlags = {'w': new Array(2), 'b': new Array(2)}; |
137 | let flags = fen.split(" ")[1]; //flags right after position | |
1d184b4c | 138 | for (let i=0; i<4; i++) |
2526c041 | 139 | this.castleFlags[i < 2 ? 'w' : 'b'][i%2] = (flags.charAt(i) == '1'); |
1d184b4c BA |
140 | } |
141 | ||
142 | /////////////////// | |
143 | // GETTERS, SETTERS | |
144 | ||
1d184b4c BA |
145 | static get size() { return [8,8]; } |
146 | // Two next functions return 'undefined' if called on empty square | |
147 | getColor(i,j) { return this.board[i][j].charAt(0); } | |
148 | getPiece(i,j) { return this.board[i][j].charAt(1); } | |
149 | ||
150 | // Color | |
151 | getOppCol(color) { return color=="w" ? "b" : "w"; } | |
152 | ||
153 | get lastMove() { | |
154 | const L = this.moves.length; | |
155 | return L>0 ? this.moves[L-1] : null; | |
156 | } | |
157 | get turn() { | |
d3334c3a | 158 | return this.moves.length%2==0 ? 'w' : 'b'; |
1d184b4c BA |
159 | } |
160 | ||
161 | // Pieces codes | |
162 | static get PAWN() { return 'p'; } | |
163 | static get ROOK() { return 'r'; } | |
164 | static get KNIGHT() { return 'n'; } | |
165 | static get BISHOP() { return 'b'; } | |
166 | static get QUEEN() { return 'q'; } | |
167 | static get KING() { return 'k'; } | |
168 | ||
169 | // Empty square | |
170 | static get EMPTY() { return ''; } | |
171 | ||
172 | // Some pieces movements | |
173 | static get steps() { | |
174 | return { | |
175 | 'r': [ [-1,0],[1,0],[0,-1],[0,1] ], | |
176 | 'n': [ [-1,-2],[-1,2],[1,-2],[1,2],[-2,-1],[-2,1],[2,-1],[2,1] ], | |
177 | 'b': [ [-1,-1],[-1,1],[1,-1],[1,1] ], | |
1d184b4c BA |
178 | }; |
179 | } | |
180 | ||
2526c041 BA |
181 | // Aggregates flags into one object |
182 | get flags() { | |
183 | return this.castleFlags; | |
184 | } | |
185 | ||
186 | // Reverse operation | |
187 | parseFlags(flags) | |
188 | { | |
189 | this.castleFlags = flags; | |
190 | } | |
191 | ||
1d184b4c BA |
192 | // En-passant square, if any |
193 | getEpSquare(move) | |
194 | { | |
195 | const [sx,sy,ex] = [move.start.x,move.start.y,move.end.x]; | |
196 | if (this.getPiece(sx,sy) == VariantRules.PAWN && Math.abs(sx - ex) == 2) | |
197 | { | |
198 | return { | |
199 | x: (sx + ex)/2, | |
200 | y: sy | |
201 | }; | |
202 | } | |
203 | return undefined; //default | |
204 | } | |
205 | ||
dda21a71 | 206 | // Can thing on square1 take thing on square2 |
46302e64 | 207 | canTake([x1,y1], [x2,y2]) |
1d184b4c | 208 | { |
46302e64 | 209 | return this.getColor(x1,y1) != this.getColor(x2,y2); |
1d184b4c BA |
210 | } |
211 | ||
212 | /////////////////// | |
213 | // MOVES GENERATION | |
214 | ||
215 | // All possible moves from selected square (assumption: color is OK) | |
216 | getPotentialMovesFrom([x,y]) | |
217 | { | |
1d184b4c BA |
218 | switch (this.getPiece(x,y)) |
219 | { | |
220 | case VariantRules.PAWN: | |
46302e64 | 221 | return this.getPotentialPawnMoves([x,y]); |
1d184b4c | 222 | case VariantRules.ROOK: |
46302e64 | 223 | return this.getPotentialRookMoves([x,y]); |
1d184b4c | 224 | case VariantRules.KNIGHT: |
46302e64 | 225 | return this.getPotentialKnightMoves([x,y]); |
1d184b4c | 226 | case VariantRules.BISHOP: |
46302e64 | 227 | return this.getPotentialBishopMoves([x,y]); |
1d184b4c | 228 | case VariantRules.QUEEN: |
46302e64 | 229 | return this.getPotentialQueenMoves([x,y]); |
1d184b4c | 230 | case VariantRules.KING: |
46302e64 | 231 | return this.getPotentialKingMoves([x,y]); |
1d184b4c BA |
232 | } |
233 | } | |
234 | ||
235 | // Build a regular move from its initial and destination squares; tr: transformation | |
46302e64 | 236 | getBasicMove([sx,sy], [ex,ey], tr) |
1d184b4c | 237 | { |
2526c041 | 238 | let mv = new Move({ |
1d184b4c BA |
239 | appear: [ |
240 | new PiPo({ | |
241 | x: ex, | |
242 | y: ey, | |
46302e64 BA |
243 | c: !!tr ? tr.c : this.getColor(sx,sy), |
244 | p: !!tr ? tr.p : this.getPiece(sx,sy) | |
1d184b4c BA |
245 | }) |
246 | ], | |
247 | vanish: [ | |
248 | new PiPo({ | |
249 | x: sx, | |
250 | y: sy, | |
251 | c: this.getColor(sx,sy), | |
252 | p: this.getPiece(sx,sy) | |
253 | }) | |
254 | ] | |
255 | }); | |
256 | ||
257 | // The opponent piece disappears if we take it | |
258 | if (this.board[ex][ey] != VariantRules.EMPTY) | |
259 | { | |
260 | mv.vanish.push( | |
261 | new PiPo({ | |
262 | x: ex, | |
263 | y: ey, | |
264 | c: this.getColor(ex,ey), | |
265 | p: this.getPiece(ex,ey) | |
266 | }) | |
267 | ); | |
268 | } | |
269 | return mv; | |
270 | } | |
271 | ||
272 | // Generic method to find possible moves of non-pawn pieces ("sliding or jumping") | |
46302e64 | 273 | getSlideNJumpMoves([x,y], steps, oneStep) |
1d184b4c | 274 | { |
46302e64 | 275 | const color = this.getColor(x,y); |
2526c041 | 276 | let moves = []; |
46302e64 | 277 | const [sizeX,sizeY] = VariantRules.size; |
1d184b4c BA |
278 | outerLoop: |
279 | for (let step of steps) | |
280 | { | |
46302e64 BA |
281 | let i = x + step[0]; |
282 | let j = y + step[1]; | |
1221ac47 BA |
283 | while (i>=0 && i<sizeX && j>=0 && j<sizeY |
284 | && this.board[i][j] == VariantRules.EMPTY) | |
1d184b4c | 285 | { |
46302e64 | 286 | moves.push(this.getBasicMove([x,y], [i,j])); |
1d184b4c BA |
287 | if (oneStep !== undefined) |
288 | continue outerLoop; | |
289 | i += step[0]; | |
290 | j += step[1]; | |
291 | } | |
efb20746 | 292 | if (i>=0 && i<sizeX && j>=0 && j<sizeY && this.canTake([x,y], [i,j])) |
46302e64 | 293 | moves.push(this.getBasicMove([x,y], [i,j])); |
1d184b4c BA |
294 | } |
295 | return moves; | |
296 | } | |
297 | ||
dda21a71 | 298 | // What are the pawn moves from square x,y ? |
46302e64 | 299 | getPotentialPawnMoves([x,y]) |
1d184b4c | 300 | { |
2526c041 BA |
301 | const color = this.turn; |
302 | let moves = []; | |
303 | const V = VariantRules; | |
1221ac47 | 304 | const [sizeX,sizeY] = V.size; |
2526c041 | 305 | const shift = (color == "w" ? -1 : 1); |
cf130369 BA |
306 | const firstRank = (color == 'w' ? sizeX-1 : 0); |
307 | const startRank = (color == "w" ? sizeX-2 : 1); | |
308 | const lastRank = (color == "w" ? 0 : sizeX-1); | |
1d184b4c BA |
309 | |
310 | if (x+shift >= 0 && x+shift < sizeX && x+shift != lastRank) | |
311 | { | |
312 | // Normal moves | |
313 | if (this.board[x+shift][y] == V.EMPTY) | |
314 | { | |
46302e64 | 315 | moves.push(this.getBasicMove([x,y], [x+shift,y])); |
1221ac47 | 316 | // Next condition because variants with pawns on 1st rank allow them to jump |
2526c041 | 317 | if ([startRank,firstRank].includes(x) && this.board[x+2*shift][y] == V.EMPTY) |
1d184b4c BA |
318 | { |
319 | // Two squares jump | |
46302e64 | 320 | moves.push(this.getBasicMove([x,y], [x+2*shift,y])); |
1d184b4c BA |
321 | } |
322 | } | |
323 | // Captures | |
1221ac47 BA |
324 | if (y>0 && this.canTake([x,y], [x+shift,y-1]) |
325 | && this.board[x+shift][y-1] != V.EMPTY) | |
326 | { | |
46302e64 | 327 | moves.push(this.getBasicMove([x,y], [x+shift,y-1])); |
1221ac47 BA |
328 | } |
329 | if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1]) | |
330 | && this.board[x+shift][y+1] != V.EMPTY) | |
331 | { | |
46302e64 | 332 | moves.push(this.getBasicMove([x,y], [x+shift,y+1])); |
1221ac47 | 333 | } |
1d184b4c BA |
334 | } |
335 | ||
336 | if (x+shift == lastRank) | |
337 | { | |
338 | // Promotion | |
68f5ccc8 | 339 | const pawnColor = this.getColor(x,y); //can be different for checkered |
1d184b4c BA |
340 | let promotionPieces = [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN]; |
341 | promotionPieces.forEach(p => { | |
342 | // Normal move | |
343 | if (this.board[x+shift][y] == V.EMPTY) | |
68f5ccc8 | 344 | moves.push(this.getBasicMove([x,y], [x+shift,y], {c:pawnColor,p:p})); |
1d184b4c | 345 | // Captures |
1221ac47 BA |
346 | if (y>0 && this.canTake([x,y], [x+shift,y-1]) |
347 | && this.board[x+shift][y-1] != V.EMPTY) | |
348 | { | |
68f5ccc8 | 349 | moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:pawnColor,p:p})); |
1221ac47 BA |
350 | } |
351 | if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1]) | |
352 | && this.board[x+shift][y+1] != V.EMPTY) | |
353 | { | |
68f5ccc8 | 354 | moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:pawnColor,p:p})); |
1221ac47 | 355 | } |
1d184b4c BA |
356 | }); |
357 | } | |
358 | ||
359 | // En passant | |
360 | const Lep = this.epSquares.length; | |
361 | const epSquare = Lep>0 ? this.epSquares[Lep-1] : undefined; | |
362 | if (!!epSquare && epSquare.x == x+shift && Math.abs(epSquare.y - y) == 1) | |
363 | { | |
364 | let epStep = epSquare.y - y; | |
46302e64 | 365 | var enpassantMove = this.getBasicMove([x,y], [x+shift,y+epStep]); |
1d184b4c BA |
366 | enpassantMove.vanish.push({ |
367 | x: x, | |
368 | y: y+epStep, | |
369 | p: 'p', | |
370 | c: this.getColor(x,y+epStep) | |
371 | }); | |
372 | moves.push(enpassantMove); | |
373 | } | |
374 | ||
375 | return moves; | |
376 | } | |
377 | ||
378 | // What are the rook moves from square x,y ? | |
46302e64 | 379 | getPotentialRookMoves(sq) |
1d184b4c | 380 | { |
46302e64 | 381 | return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.ROOK]); |
1d184b4c BA |
382 | } |
383 | ||
384 | // What are the knight moves from square x,y ? | |
46302e64 | 385 | getPotentialKnightMoves(sq) |
1d184b4c | 386 | { |
92342261 BA |
387 | return this.getSlideNJumpMoves( |
388 | sq, VariantRules.steps[VariantRules.KNIGHT], "oneStep"); | |
1d184b4c BA |
389 | } |
390 | ||
391 | // What are the bishop moves from square x,y ? | |
46302e64 | 392 | getPotentialBishopMoves(sq) |
1d184b4c | 393 | { |
46302e64 | 394 | return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.BISHOP]); |
1d184b4c BA |
395 | } |
396 | ||
397 | // What are the queen moves from square x,y ? | |
46302e64 | 398 | getPotentialQueenMoves(sq) |
1d184b4c | 399 | { |
a37076f1 BA |
400 | const V = VariantRules; |
401 | return this.getSlideNJumpMoves(sq, V.steps[V.ROOK].concat(V.steps[V.BISHOP])); | |
1d184b4c BA |
402 | } |
403 | ||
404 | // What are the king moves from square x,y ? | |
46302e64 | 405 | getPotentialKingMoves(sq) |
1d184b4c | 406 | { |
a37076f1 | 407 | const V = VariantRules; |
1d184b4c | 408 | // Initialize with normal moves |
a37076f1 BA |
409 | let moves = this.getSlideNJumpMoves(sq, |
410 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep"); | |
46302e64 | 411 | return moves.concat(this.getCastleMoves(sq)); |
1d184b4c BA |
412 | } |
413 | ||
46302e64 | 414 | getCastleMoves([x,y]) |
1d184b4c | 415 | { |
46302e64 | 416 | const c = this.getColor(x,y); |
c6052161 BA |
417 | const [sizeX,sizeY] = VariantRules.size; |
418 | if (x != (c=="w" ? sizeX-1 : 0) || y != this.INIT_COL_KING[c]) | |
1d184b4c BA |
419 | return []; //x isn't first rank, or king has moved (shortcut) |
420 | ||
421 | const V = VariantRules; | |
422 | ||
423 | // Castling ? | |
424 | const oppCol = this.getOppCol(c); | |
425 | let moves = []; | |
426 | let i = 0; | |
c6052161 | 427 | const finalSquares = [ [2,3], [sizeY-2,sizeY-3] ]; //king, then rook |
1d184b4c BA |
428 | castlingCheck: |
429 | for (let castleSide=0; castleSide < 2; castleSide++) //large, then small | |
430 | { | |
2526c041 | 431 | if (!this.castleFlags[c][castleSide]) |
1d184b4c BA |
432 | continue; |
433 | // If this code is reached, rooks and king are on initial position | |
434 | ||
435 | // Nothing on the path of the king (and no checks; OK also if y==finalSquare)? | |
436 | let step = finalSquares[castleSide][0] < y ? -1 : 1; | |
437 | for (i=y; i!=finalSquares[castleSide][0]; i+=step) | |
438 | { | |
cf130369 | 439 | if (this.isAttacked([x,i], [oppCol]) || (this.board[x][i] != V.EMPTY && |
1d184b4c BA |
440 | // NOTE: next check is enough, because of chessboard constraints |
441 | (this.getColor(x,i) != c || ![V.KING,V.ROOK].includes(this.getPiece(x,i))))) | |
442 | { | |
443 | continue castlingCheck; | |
444 | } | |
445 | } | |
446 | ||
447 | // Nothing on the path to the rook? | |
448 | step = castleSide == 0 ? -1 : 1; | |
449 | for (i = y + step; i != this.INIT_COL_ROOK[c][castleSide]; i += step) | |
450 | { | |
451 | if (this.board[x][i] != V.EMPTY) | |
452 | continue castlingCheck; | |
453 | } | |
454 | const rookPos = this.INIT_COL_ROOK[c][castleSide]; | |
455 | ||
456 | // Nothing on final squares, except maybe king and castling rook? | |
457 | for (i=0; i<2; i++) | |
458 | { | |
459 | if (this.board[x][finalSquares[castleSide][i]] != V.EMPTY && | |
460 | this.getPiece(x,finalSquares[castleSide][i]) != V.KING && | |
461 | finalSquares[castleSide][i] != rookPos) | |
462 | { | |
463 | continue castlingCheck; | |
464 | } | |
465 | } | |
466 | ||
467 | // If this code is reached, castle is valid | |
468 | moves.push( new Move({ | |
469 | appear: [ | |
470 | new PiPo({x:x,y:finalSquares[castleSide][0],p:V.KING,c:c}), | |
471 | new PiPo({x:x,y:finalSquares[castleSide][1],p:V.ROOK,c:c})], | |
472 | vanish: [ | |
473 | new PiPo({x:x,y:y,p:V.KING,c:c}), | |
474 | new PiPo({x:x,y:rookPos,p:V.ROOK,c:c})], | |
475 | end: Math.abs(y - rookPos) <= 2 | |
476 | ? {x:x, y:rookPos} | |
477 | : {x:x, y:y + 2 * (castleSide==0 ? -1 : 1)} | |
478 | }) ); | |
479 | } | |
480 | ||
481 | return moves; | |
482 | } | |
483 | ||
484 | /////////////////// | |
485 | // MOVES VALIDATION | |
486 | ||
46302e64 | 487 | canIplay(side, [x,y]) |
1d184b4c | 488 | { |
92342261 BA |
489 | return ((side=='w' && this.moves.length%2==0) |
490 | || (side=='b' && this.moves.length%2==1)) | |
46302e64 | 491 | && this.getColor(x,y) == side; |
1d184b4c BA |
492 | } |
493 | ||
494 | getPossibleMovesFrom(sq) | |
495 | { | |
496 | // Assuming color is right (already checked) | |
497 | return this.filterValid( this.getPotentialMovesFrom(sq) ); | |
498 | } | |
499 | ||
92342261 | 500 | // TODO: promotions (into R,B,N,Q) should be filtered only once |
1d184b4c BA |
501 | filterValid(moves) |
502 | { | |
503 | if (moves.length == 0) | |
504 | return []; | |
b8121223 | 505 | return moves.filter(m => { return !this.underCheck(m); }); |
1d184b4c BA |
506 | } |
507 | ||
508 | // Search for all valid moves considering current turn (for engine and game end) | |
46302e64 | 509 | getAllValidMoves() |
1d184b4c | 510 | { |
46302e64 | 511 | const color = this.turn; |
1d184b4c | 512 | const oppCol = this.getOppCol(color); |
c6052161 BA |
513 | let potentialMoves = []; |
514 | const [sizeX,sizeY] = VariantRules.size; | |
a6abf094 | 515 | for (let i=0; i<sizeX; i++) |
1d184b4c | 516 | { |
a6abf094 | 517 | for (let j=0; j<sizeY; j++) |
1d184b4c | 518 | { |
92342261 | 519 | // Next condition "!= oppCol" = harmless hack to work with checkered variant |
1d184b4c BA |
520 | if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) != oppCol) |
521 | Array.prototype.push.apply(potentialMoves, this.getPotentialMovesFrom([i,j])); | |
522 | } | |
523 | } | |
524 | // NOTE: prefer lazy undercheck tests, letting the king being taken? | |
525 | // No: if happen on last 1/2 move, could lead to forbidden moves, wrong evals | |
526 | return this.filterValid(potentialMoves); | |
527 | } | |
9de73b71 | 528 | |
e64a4eff | 529 | // Stop at the first move found |
46302e64 | 530 | atLeastOneMove() |
e64a4eff | 531 | { |
46302e64 | 532 | const color = this.turn; |
e64a4eff | 533 | const oppCol = this.getOppCol(color); |
c6052161 | 534 | const [sizeX,sizeY] = VariantRules.size; |
9de73b71 | 535 | for (let i=0; i<sizeX; i++) |
e64a4eff | 536 | { |
9de73b71 | 537 | for (let j=0; j<sizeY; j++) |
e64a4eff BA |
538 | { |
539 | if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) != oppCol) | |
540 | { | |
541 | const moves = this.getPotentialMovesFrom([i,j]); | |
542 | if (moves.length > 0) | |
543 | { | |
9de73b71 | 544 | for (let k=0; k<moves.length; k++) |
e64a4eff | 545 | { |
9de73b71 | 546 | if (this.filterValid([moves[k]]).length > 0) |
e64a4eff BA |
547 | return true; |
548 | } | |
549 | } | |
550 | } | |
551 | } | |
552 | } | |
553 | return false; | |
554 | } | |
1d184b4c | 555 | |
dda21a71 | 556 | // Check if pieces of color in array 'colors' are attacking square x,y |
46302e64 | 557 | isAttacked(sq, colors) |
1d184b4c | 558 | { |
46302e64 BA |
559 | return (this.isAttackedByPawn(sq, colors) |
560 | || this.isAttackedByRook(sq, colors) | |
561 | || this.isAttackedByKnight(sq, colors) | |
562 | || this.isAttackedByBishop(sq, colors) | |
563 | || this.isAttackedByQueen(sq, colors) | |
564 | || this.isAttackedByKing(sq, colors)); | |
1d184b4c BA |
565 | } |
566 | ||
dda21a71 | 567 | // Is square x,y attacked by 'colors' pawns ? |
46302e64 | 568 | isAttackedByPawn([x,y], colors) |
1d184b4c | 569 | { |
efb20746 | 570 | const [sizeX,sizeY] = VariantRules.size; |
46302e64 | 571 | for (let c of colors) |
1d184b4c | 572 | { |
46302e64 | 573 | let pawnShift = (c=="w" ? 1 : -1); |
efb20746 | 574 | if (x+pawnShift>=0 && x+pawnShift<sizeX) |
1d184b4c | 575 | { |
46302e64 | 576 | for (let i of [-1,1]) |
1d184b4c | 577 | { |
efb20746 | 578 | if (y+i>=0 && y+i<sizeY && this.getPiece(x+pawnShift,y+i)==VariantRules.PAWN |
46302e64 BA |
579 | && this.getColor(x+pawnShift,y+i)==c) |
580 | { | |
581 | return true; | |
582 | } | |
1d184b4c BA |
583 | } |
584 | } | |
585 | } | |
586 | return false; | |
587 | } | |
588 | ||
dda21a71 | 589 | // Is square x,y attacked by 'colors' rooks ? |
46302e64 | 590 | isAttackedByRook(sq, colors) |
1d184b4c | 591 | { |
46302e64 | 592 | return this.isAttackedBySlideNJump(sq, colors, |
1d184b4c BA |
593 | VariantRules.ROOK, VariantRules.steps[VariantRules.ROOK]); |
594 | } | |
595 | ||
dda21a71 | 596 | // Is square x,y attacked by 'colors' knights ? |
46302e64 | 597 | isAttackedByKnight(sq, colors) |
1d184b4c | 598 | { |
46302e64 | 599 | return this.isAttackedBySlideNJump(sq, colors, |
1d184b4c BA |
600 | VariantRules.KNIGHT, VariantRules.steps[VariantRules.KNIGHT], "oneStep"); |
601 | } | |
602 | ||
dda21a71 | 603 | // Is square x,y attacked by 'colors' bishops ? |
46302e64 | 604 | isAttackedByBishop(sq, colors) |
1d184b4c | 605 | { |
46302e64 | 606 | return this.isAttackedBySlideNJump(sq, colors, |
1d184b4c BA |
607 | VariantRules.BISHOP, VariantRules.steps[VariantRules.BISHOP]); |
608 | } | |
609 | ||
dda21a71 | 610 | // Is square x,y attacked by 'colors' queens ? |
46302e64 | 611 | isAttackedByQueen(sq, colors) |
1d184b4c | 612 | { |
a37076f1 BA |
613 | const V = VariantRules; |
614 | return this.isAttackedBySlideNJump(sq, colors, V.QUEEN, | |
615 | V.steps[V.ROOK].concat(V.steps[V.BISHOP])); | |
1d184b4c BA |
616 | } |
617 | ||
dda21a71 | 618 | // Is square x,y attacked by 'colors' king(s) ? |
46302e64 | 619 | isAttackedByKing(sq, colors) |
1d184b4c | 620 | { |
a37076f1 BA |
621 | const V = VariantRules; |
622 | return this.isAttackedBySlideNJump(sq, colors, V.KING, | |
623 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep"); | |
1d184b4c BA |
624 | } |
625 | ||
1221ac47 | 626 | // Generic method for non-pawn pieces ("sliding or jumping"): |
dda21a71 | 627 | // is x,y attacked by a piece of color in array 'colors' ? |
46302e64 | 628 | isAttackedBySlideNJump([x,y], colors, piece, steps, oneStep) |
1d184b4c | 629 | { |
efb20746 | 630 | const [sizeX,sizeY] = VariantRules.size; |
1d184b4c BA |
631 | for (let step of steps) |
632 | { | |
633 | let rx = x+step[0], ry = y+step[1]; | |
efb20746 BA |
634 | while (rx>=0 && rx<sizeX && ry>=0 && ry<sizeY |
635 | && this.board[rx][ry] == VariantRules.EMPTY && !oneStep) | |
1d184b4c BA |
636 | { |
637 | rx += step[0]; | |
638 | ry += step[1]; | |
639 | } | |
efb20746 BA |
640 | if (rx>=0 && rx<sizeX && ry>=0 && ry<sizeY |
641 | && this.board[rx][ry] != VariantRules.EMPTY | |
46302e64 | 642 | && this.getPiece(rx,ry) == piece && colors.includes(this.getColor(rx,ry))) |
1d184b4c BA |
643 | { |
644 | return true; | |
645 | } | |
646 | } | |
647 | return false; | |
648 | } | |
649 | ||
dda21a71 | 650 | // Is current player under check after his move ? |
46302e64 | 651 | underCheck(move) |
1d184b4c | 652 | { |
46302e64 | 653 | const color = this.turn; |
1d184b4c | 654 | this.play(move); |
cf130369 | 655 | let res = this.isAttacked(this.kingPos[color], [this.getOppCol(color)]); |
1d184b4c BA |
656 | this.undo(move); |
657 | return res; | |
658 | } | |
659 | ||
dda21a71 | 660 | // On which squares is opponent under check after our move ? |
46302e64 | 661 | getCheckSquares(move) |
4b5fe306 BA |
662 | { |
663 | this.play(move); | |
204e289b | 664 | const color = this.turn; //opponent |
cf130369 | 665 | let res = this.isAttacked(this.kingPos[color], [this.getOppCol(color)]) |
46302e64 | 666 | ? [ JSON.parse(JSON.stringify(this.kingPos[color])) ] //need to duplicate! |
4b5fe306 BA |
667 | : [ ]; |
668 | this.undo(move); | |
669 | return res; | |
670 | } | |
671 | ||
1d184b4c BA |
672 | // Apply a move on board |
673 | static PlayOnBoard(board, move) | |
674 | { | |
675 | for (let psq of move.vanish) | |
676 | board[psq.x][psq.y] = VariantRules.EMPTY; | |
677 | for (let psq of move.appear) | |
678 | board[psq.x][psq.y] = psq.c + psq.p; | |
679 | } | |
680 | // Un-apply the played move | |
681 | static UndoOnBoard(board, move) | |
682 | { | |
683 | for (let psq of move.appear) | |
684 | board[psq.x][psq.y] = VariantRules.EMPTY; | |
685 | for (let psq of move.vanish) | |
686 | board[psq.x][psq.y] = psq.c + psq.p; | |
687 | } | |
688 | ||
d3334c3a | 689 | // Before move is played, update variables + flags |
1d184b4c BA |
690 | updateVariables(move) |
691 | { | |
692 | const piece = this.getPiece(move.start.x,move.start.y); | |
693 | const c = this.getColor(move.start.x,move.start.y); | |
c6052161 BA |
694 | const [sizeX,sizeY] = VariantRules.size; |
695 | const firstRank = (c == "w" ? sizeX-1 : 0); | |
1d184b4c BA |
696 | |
697 | // Update king position + flags | |
698 | if (piece == VariantRules.KING && move.appear.length > 0) | |
699 | { | |
700 | this.kingPos[c][0] = move.appear[0].x; | |
701 | this.kingPos[c][1] = move.appear[0].y; | |
2526c041 | 702 | this.castleFlags[c] = [false,false]; |
1d184b4c BA |
703 | return; |
704 | } | |
705 | const oppCol = this.getOppCol(c); | |
c6052161 | 706 | const oppFirstRank = (sizeX-1) - firstRank; |
1d184b4c BA |
707 | if (move.start.x == firstRank //our rook moves? |
708 | && this.INIT_COL_ROOK[c].includes(move.start.y)) | |
709 | { | |
2526c041 BA |
710 | const flagIdx = (move.start.y == this.INIT_COL_ROOK[c][0] ? 0 : 1); |
711 | this.castleFlags[c][flagIdx] = false; | |
1d184b4c BA |
712 | } |
713 | else if (move.end.x == oppFirstRank //we took opponent rook? | |
aea1443e | 714 | && this.INIT_COL_ROOK[oppCol].includes(move.end.y)) |
1d184b4c | 715 | { |
2526c041 BA |
716 | const flagIdx = (move.end.y == this.INIT_COL_ROOK[oppCol][0] ? 0 : 1); |
717 | this.castleFlags[oppCol][flagIdx] = false; | |
1d184b4c BA |
718 | } |
719 | } | |
720 | ||
dda21a71 BA |
721 | // After move is undo-ed, un-update variables (flags are reset) |
722 | // TODO: more symmetry, by storing flags increment in move... | |
d3334c3a | 723 | unupdateVariables(move) |
1d184b4c | 724 | { |
d3334c3a BA |
725 | // (Potentially) Reset king position |
726 | const c = this.getColor(move.start.x,move.start.y); | |
727 | if (this.getPiece(move.start.x,move.start.y) == VariantRules.KING) | |
728 | this.kingPos[c] = [move.start.x, move.start.y]; | |
729 | } | |
1d184b4c | 730 | |
331fc58c BA |
731 | // Store a hash of the position + flags + turn after a move is played |
732 | // (for repetitions detection) | |
733 | addHashState() | |
734 | { | |
735 | const strToHash = this.getFen() + " " + this.turn; | |
736 | const hash = hex_md5(strToHash); | |
737 | if (!this.hashStates[hash]) | |
738 | this.hashStates[hash] = 1; | |
739 | else | |
740 | this.hashStates[hash]++; | |
741 | } | |
742 | ||
d3334c3a BA |
743 | play(move, ingame) |
744 | { | |
a3c86ec9 BA |
745 | // DEBUG: |
746 | // if (!this.states) this.states = []; | |
747 | // if (!ingame) this.states.push(JSON.stringify(this.board)); | |
748 | ||
dfb4afc1 | 749 | if (!!ingame) |
6752407b | 750 | move.notation = [this.getNotation(move), this.getLongNotation(move)]; |
dfb4afc1 | 751 | |
2526c041 | 752 | move.flags = JSON.stringify(this.flags); //save flags (for undo) |
d3334c3a BA |
753 | this.updateVariables(move); |
754 | this.moves.push(move); | |
1d184b4c BA |
755 | this.epSquares.push( this.getEpSquare(move) ); |
756 | VariantRules.PlayOnBoard(this.board, move); | |
331fc58c BA |
757 | |
758 | if (!!ingame) | |
759 | this.addHashState(); | |
1d184b4c BA |
760 | } |
761 | ||
cd4cad04 | 762 | undo(move) |
1d184b4c BA |
763 | { |
764 | VariantRules.UndoOnBoard(this.board, move); | |
765 | this.epSquares.pop(); | |
d3334c3a BA |
766 | this.moves.pop(); |
767 | this.unupdateVariables(move); | |
2526c041 | 768 | this.parseFlags(JSON.parse(move.flags)); |
a3c86ec9 BA |
769 | |
770 | // DEBUG: | |
771 | // if (JSON.stringify(this.board) != this.states[this.states.length-1]) | |
772 | // debugger; | |
773 | // this.states.pop(); | |
1d184b4c BA |
774 | } |
775 | ||
776 | ////////////// | |
777 | // END OF GAME | |
778 | ||
331fc58c | 779 | // Check for 3 repetitions (position + flags + turn) |
1af36beb | 780 | checkRepetition() |
1d184b4c | 781 | { |
331fc58c | 782 | return Object.values(this.hashStates).some(elt => { return (elt >= 3); }); |
1af36beb | 783 | } |
1d184b4c | 784 | |
dda21a71 | 785 | // Is game over ? And if yes, what is the score ? |
1af36beb BA |
786 | checkGameOver() |
787 | { | |
788 | if (this.checkRepetition()) | |
789 | return "1/2"; | |
790 | ||
791 | if (this.atLeastOneMove()) // game not over | |
1d184b4c | 792 | return "*"; |
1d184b4c BA |
793 | |
794 | // Game over | |
46302e64 | 795 | return this.checkGameEnd(); |
1d184b4c BA |
796 | } |
797 | ||
46302e64 BA |
798 | // No moves are possible: compute score |
799 | checkGameEnd() | |
1d184b4c | 800 | { |
46302e64 | 801 | const color = this.turn; |
1d184b4c | 802 | // No valid move: stalemate or checkmate? |
cf130369 | 803 | if (!this.isAttacked(this.kingPos[color], [this.getOppCol(color)])) |
1d184b4c BA |
804 | return "1/2"; |
805 | // OK, checkmate | |
806 | return color == "w" ? "0-1" : "1-0"; | |
807 | } | |
808 | ||
809 | //////// | |
810 | //ENGINE | |
811 | ||
812 | // Pieces values | |
813 | static get VALUES() { | |
814 | return { | |
815 | 'p': 1, | |
816 | 'r': 5, | |
817 | 'n': 3, | |
818 | 'b': 3, | |
819 | 'q': 9, | |
820 | 'k': 1000 | |
821 | }; | |
822 | } | |
823 | ||
9e42b4dd BA |
824 | static get INFINITY() { |
825 | return 9999; //"checkmate" (unreachable eval) | |
826 | } | |
827 | ||
828 | static get THRESHOLD_MATE() { | |
829 | // At this value or above, the game is over | |
830 | return VariantRules.INFINITY; | |
831 | } | |
832 | ||
3c09dc49 BA |
833 | static get SEARCH_DEPTH() { |
834 | return 3; //2 for high branching factor, 4 for small (Loser chess) | |
835 | } | |
836 | ||
1d184b4c | 837 | // Assumption: at least one legal move |
a6abf094 BA |
838 | // NOTE: works also for extinction chess because depth is 3... |
839 | getComputerMove() | |
1d184b4c | 840 | { |
9e42b4dd | 841 | const maxeval = VariantRules.INFINITY; |
46302e64 | 842 | const color = this.turn; |
15952ada BA |
843 | // Some variants may show a bigger moves list to the human (Switching), |
844 | // thus the argument "computer" below (which is generally ignored) | |
845 | let moves1 = this.getAllValidMoves("computer"); | |
a6abf094 BA |
846 | |
847 | // Can I mate in 1 ? (for Magnetic & Extinction) | |
848 | for (let i of _.shuffle(_.range(moves1.length))) | |
849 | { | |
850 | this.play(moves1[i]); | |
851 | const finish = (Math.abs(this.evalPosition()) >= VariantRules.THRESHOLD_MATE); | |
852 | this.undo(moves1[i]); | |
853 | if (finish) | |
854 | return moves1[i]; | |
855 | } | |
1d184b4c | 856 | |
06ddfe34 | 857 | // Rank moves using a min-max at depth 2 |
1d184b4c BA |
858 | for (let i=0; i<moves1.length; i++) |
859 | { | |
9e42b4dd | 860 | moves1[i].eval = (color=="w" ? -1 : 1) * maxeval; //very low, I'm checkmated |
1d184b4c | 861 | this.play(moves1[i]); |
68f5ccc8 BA |
862 | let eval2 = undefined; |
863 | if (this.atLeastOneMove()) | |
1d184b4c | 864 | { |
68f5ccc8 BA |
865 | eval2 = (color=="w" ? 1 : -1) * maxeval; //initialized with checkmate value |
866 | // Second half-move: | |
15952ada | 867 | let moves2 = this.getAllValidMoves("computer"); |
68f5ccc8 BA |
868 | for (let j=0; j<moves2.length; j++) |
869 | { | |
870 | this.play(moves2[j]); | |
871 | let evalPos = undefined; | |
872 | if (this.atLeastOneMove()) | |
873 | evalPos = this.evalPosition() | |
874 | else | |
875 | { | |
876 | // Work with scores for Loser variant | |
877 | const score = this.checkGameEnd(); | |
878 | evalPos = (score=="1/2" ? 0 : (score=="1-0" ? 1 : -1) * maxeval); | |
879 | } | |
880 | if ((color == "w" && evalPos < eval2) || (color=="b" && evalPos > eval2)) | |
881 | eval2 = evalPos; | |
882 | this.undo(moves2[j]); | |
883 | } | |
884 | } | |
885 | else | |
886 | { | |
887 | const score = this.checkGameEnd(); | |
888 | eval2 = (score=="1/2" ? 0 : (score=="1-0" ? 1 : -1) * maxeval); | |
1d184b4c | 889 | } |
92342261 BA |
890 | if ((color=="w" && eval2 > moves1[i].eval) |
891 | || (color=="b" && eval2 < moves1[i].eval)) | |
892 | { | |
1d184b4c | 893 | moves1[i].eval = eval2; |
92342261 | 894 | } |
1d184b4c BA |
895 | this.undo(moves1[i]); |
896 | } | |
897 | moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); }); | |
11a31682 | 898 | //console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; })); |
1d184b4c | 899 | |
3c09dc49 BA |
900 | let candidates = [0]; //indices of candidates moves |
901 | for (let j=1; j<moves1.length && moves1[j].eval == moves1[0].eval; j++) | |
902 | candidates.push(j); | |
903 | let currentBest = moves1[_.sample(candidates, 1)]; | |
904 | ||
e82cd979 BA |
905 | // From here, depth >= 3: may take a while, so we control time |
906 | const timeStart = Date.now(); | |
907 | ||
a6abf094 | 908 | // Skip depth 3+ if we found a checkmate (or if we are checkmated in 1...) |
3c09dc49 BA |
909 | if (VariantRules.SEARCH_DEPTH >= 3 |
910 | && Math.abs(moves1[0].eval) < VariantRules.THRESHOLD_MATE) | |
e64a4eff | 911 | { |
9e42b4dd BA |
912 | for (let i=0; i<moves1.length; i++) |
913 | { | |
e82cd979 BA |
914 | if (Date.now()-timeStart >= 5000) //more than 5 seconds |
915 | return currentBest; //depth 2 at least | |
9e42b4dd BA |
916 | this.play(moves1[i]); |
917 | // 0.1 * oldEval : heuristic to avoid some bad moves (not all...) | |
3c09dc49 BA |
918 | moves1[i].eval = 0.1*moves1[i].eval + |
919 | this.alphabeta(VariantRules.SEARCH_DEPTH-1, -maxeval, maxeval); | |
9e42b4dd BA |
920 | this.undo(moves1[i]); |
921 | } | |
922 | moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); }); | |
e64a4eff | 923 | } |
3c09dc49 BA |
924 | else |
925 | return currentBest; | |
68f5ccc8 | 926 | //console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; })); |
1d184b4c | 927 | |
3c09dc49 | 928 | candidates = [0]; |
1d184b4c BA |
929 | for (let j=1; j<moves1.length && moves1[j].eval == moves1[0].eval; j++) |
930 | candidates.push(j); | |
1d184b4c BA |
931 | return moves1[_.sample(candidates, 1)]; |
932 | } | |
933 | ||
46302e64 | 934 | alphabeta(depth, alpha, beta) |
1d184b4c | 935 | { |
9e42b4dd | 936 | const maxeval = VariantRules.INFINITY; |
46302e64 BA |
937 | const color = this.turn; |
938 | if (!this.atLeastOneMove()) | |
1d184b4c | 939 | { |
46302e64 | 940 | switch (this.checkGameEnd()) |
1d184b4c | 941 | { |
68f5ccc8 BA |
942 | case "1/2": |
943 | return 0; | |
944 | default: | |
945 | const score = this.checkGameEnd(); | |
946 | return (score=="1/2" ? 0 : (score=="1-0" ? 1 : -1) * maxeval); | |
1d184b4c BA |
947 | } |
948 | } | |
949 | if (depth == 0) | |
950 | return this.evalPosition(); | |
15952ada | 951 | const moves = this.getAllValidMoves("computer"); |
9e42b4dd | 952 | let v = color=="w" ? -maxeval : maxeval; |
1d184b4c BA |
953 | if (color == "w") |
954 | { | |
955 | for (let i=0; i<moves.length; i++) | |
956 | { | |
957 | this.play(moves[i]); | |
46302e64 | 958 | v = Math.max(v, this.alphabeta(depth-1, alpha, beta)); |
1d184b4c BA |
959 | this.undo(moves[i]); |
960 | alpha = Math.max(alpha, v); | |
961 | if (alpha >= beta) | |
962 | break; //beta cutoff | |
963 | } | |
964 | } | |
965 | else //color=="b" | |
966 | { | |
967 | for (let i=0; i<moves.length; i++) | |
968 | { | |
969 | this.play(moves[i]); | |
46302e64 | 970 | v = Math.min(v, this.alphabeta(depth-1, alpha, beta)); |
1d184b4c BA |
971 | this.undo(moves[i]); |
972 | beta = Math.min(beta, v); | |
973 | if (alpha >= beta) | |
974 | break; //alpha cutoff | |
975 | } | |
976 | } | |
977 | return v; | |
978 | } | |
979 | ||
980 | evalPosition() | |
981 | { | |
982 | const [sizeX,sizeY] = VariantRules.size; | |
983 | let evaluation = 0; | |
a6abf094 | 984 | // Just count material for now |
1d184b4c BA |
985 | for (let i=0; i<sizeX; i++) |
986 | { | |
987 | for (let j=0; j<sizeY; j++) | |
988 | { | |
989 | if (this.board[i][j] != VariantRules.EMPTY) | |
990 | { | |
991 | const sign = this.getColor(i,j) == "w" ? 1 : -1; | |
992 | evaluation += sign * VariantRules.VALUES[this.getPiece(i,j)]; | |
993 | } | |
994 | } | |
995 | } | |
996 | return evaluation; | |
997 | } | |
998 | ||
999 | //////////// | |
1000 | // FEN utils | |
1001 | ||
dda21a71 | 1002 | // Setup the initial random (assymetric) position |
1d184b4c BA |
1003 | static GenRandInitFen() |
1004 | { | |
32cfcea4 | 1005 | let pieces = { "w": new Array(8), "b": new Array(8) }; |
1d184b4c | 1006 | // Shuffle pieces on first and last rank |
32cfcea4 | 1007 | for (let c of ["w","b"]) |
1d184b4c BA |
1008 | { |
1009 | let positions = _.range(8); | |
1010 | ||
1011 | // Get random squares for bishops | |
1012 | let randIndex = 2 * _.random(3); | |
1013 | let bishop1Pos = positions[randIndex]; | |
1014 | // The second bishop must be on a square of different color | |
1015 | let randIndex_tmp = 2 * _.random(3) + 1; | |
1016 | let bishop2Pos = positions[randIndex_tmp]; | |
1017 | // Remove chosen squares | |
1018 | positions.splice(Math.max(randIndex,randIndex_tmp), 1); | |
1019 | positions.splice(Math.min(randIndex,randIndex_tmp), 1); | |
1020 | ||
1021 | // Get random squares for knights | |
1022 | randIndex = _.random(5); | |
1023 | let knight1Pos = positions[randIndex]; | |
1024 | positions.splice(randIndex, 1); | |
1025 | randIndex = _.random(4); | |
1026 | let knight2Pos = positions[randIndex]; | |
1027 | positions.splice(randIndex, 1); | |
1028 | ||
1029 | // Get random square for queen | |
1030 | randIndex = _.random(3); | |
1031 | let queenPos = positions[randIndex]; | |
1032 | positions.splice(randIndex, 1); | |
1033 | ||
1034 | // Rooks and king positions are now fixed, because of the ordering rook-king-rook | |
1035 | let rook1Pos = positions[0]; | |
1036 | let kingPos = positions[1]; | |
1037 | let rook2Pos = positions[2]; | |
1038 | ||
1039 | // Finally put the shuffled pieces in the board array | |
1040 | pieces[c][rook1Pos] = 'r'; | |
1041 | pieces[c][knight1Pos] = 'n'; | |
1042 | pieces[c][bishop1Pos] = 'b'; | |
1043 | pieces[c][queenPos] = 'q'; | |
1044 | pieces[c][kingPos] = 'k'; | |
1045 | pieces[c][bishop2Pos] = 'b'; | |
1046 | pieces[c][knight2Pos] = 'n'; | |
1047 | pieces[c][rook2Pos] = 'r'; | |
1048 | } | |
2eef6db6 | 1049 | return pieces["b"].join("") + |
1d184b4c | 1050 | "/pppppppp/8/8/8/8/PPPPPPPP/" + |
32cfcea4 | 1051 | pieces["w"].join("").toUpperCase() + |
f3802fcd | 1052 | " 1111"; //add flags |
1d184b4c BA |
1053 | } |
1054 | ||
1055 | // Return current fen according to pieces+colors state | |
1056 | getFen() | |
1057 | { | |
f3802fcd | 1058 | return this.getBaseFen() + " " + this.getFlagsFen(); |
1d184b4c BA |
1059 | } |
1060 | ||
dda21a71 | 1061 | // Position part of the FEN string |
1d184b4c BA |
1062 | getBaseFen() |
1063 | { | |
1064 | let fen = ""; | |
1065 | let [sizeX,sizeY] = VariantRules.size; | |
1066 | for (let i=0; i<sizeX; i++) | |
1067 | { | |
1068 | let emptyCount = 0; | |
1069 | for (let j=0; j<sizeY; j++) | |
1070 | { | |
1071 | if (this.board[i][j] == VariantRules.EMPTY) | |
1072 | emptyCount++; | |
1073 | else | |
1074 | { | |
1075 | if (emptyCount > 0) | |
1076 | { | |
1077 | // Add empty squares in-between | |
1078 | fen += emptyCount; | |
1079 | emptyCount = 0; | |
1080 | } | |
1081 | fen += VariantRules.board2fen(this.board[i][j]); | |
1082 | } | |
1083 | } | |
1084 | if (emptyCount > 0) | |
1085 | { | |
1086 | // "Flush remainder" | |
1087 | fen += emptyCount; | |
1088 | } | |
1089 | if (i < sizeX - 1) | |
1090 | fen += "/"; //separate rows | |
1091 | } | |
1092 | return fen; | |
1093 | } | |
1094 | ||
dda21a71 | 1095 | // Flags part of the FEN string |
1d184b4c BA |
1096 | getFlagsFen() |
1097 | { | |
1098 | let fen = ""; | |
1099 | // Add castling flags | |
1100 | for (let i of ['w','b']) | |
1101 | { | |
1102 | for (let j=0; j<2; j++) | |
77e1ec78 | 1103 | fen += (this.castleFlags[i][j] ? '1' : '0'); |
1d184b4c BA |
1104 | } |
1105 | return fen; | |
1106 | } | |
1107 | ||
1108 | // Context: just before move is played, turn hasn't changed | |
1109 | getNotation(move) | |
1110 | { | |
15952ada BA |
1111 | if (move.appear.length == 2 && move.appear[0].p == VariantRules.KING) //castle |
1112 | return (move.end.y < move.start.y ? "0-0-0" : "0-0"); | |
1d184b4c BA |
1113 | |
1114 | // Translate final square | |
270968d6 | 1115 | const finalSquare = |
1d184b4c BA |
1116 | String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x); |
1117 | ||
270968d6 | 1118 | const piece = this.getPiece(move.start.x, move.start.y); |
1d184b4c BA |
1119 | if (piece == VariantRules.PAWN) |
1120 | { | |
1121 | // Pawn move | |
1122 | let notation = ""; | |
5bfb0956 | 1123 | if (move.vanish.length > move.appear.length) |
1d184b4c BA |
1124 | { |
1125 | // Capture | |
270968d6 | 1126 | const startColumn = String.fromCharCode(97 + move.start.y); |
1d184b4c BA |
1127 | notation = startColumn + "x" + finalSquare; |
1128 | } | |
1129 | else //no capture | |
1130 | notation = finalSquare; | |
1131 | if (move.appear.length > 0 && piece != move.appear[0].p) //promotion | |
1132 | notation += "=" + move.appear[0].p.toUpperCase(); | |
1133 | return notation; | |
1134 | } | |
1135 | ||
1136 | else | |
1137 | { | |
1138 | // Piece movement | |
f3c10e18 BA |
1139 | return piece.toUpperCase() + |
1140 | (move.vanish.length > move.appear.length ? "x" : "") + finalSquare; | |
1d184b4c BA |
1141 | } |
1142 | } | |
dfb4afc1 | 1143 | |
6752407b BA |
1144 | // Complete the usual notation, may be required for de-ambiguification |
1145 | getLongNotation(move) | |
1146 | { | |
1147 | const startSquare = | |
1148 | String.fromCharCode(97 + move.start.y) + (VariantRules.size[0]-move.start.x); | |
1149 | const finalSquare = | |
1150 | String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x); | |
1151 | return startSquare + finalSquare; //not encoding move. But short+long is enough | |
1152 | } | |
1153 | ||
dfb4afc1 | 1154 | // The score is already computed when calling this function |
01a135e2 | 1155 | getPGN(mycolor, score, fenStart, mode) |
dfb4afc1 | 1156 | { |
16984853 | 1157 | const zeroPad = x => { return (x<10 ? "0" : "") + x; }; |
dfb4afc1 BA |
1158 | let pgn = ""; |
1159 | pgn += '[Site "vchess.club"]<br>'; | |
1160 | const d = new Date(); | |
5e622704 | 1161 | const opponent = mode=="human" ? "Anonymous" : "Computer"; |
0f51ef98 | 1162 | pgn += '[Variant "' + variant + '"]<br>'; |
92342261 BA |
1163 | pgn += '[Date "' + d.getFullYear() + '-' + (d.getMonth()+1) + |
1164 | '-' + zeroPad(d.getDate()) + '"]<br>'; | |
01a135e2 BA |
1165 | pgn += '[White "' + (mycolor=='w'?'Myself':opponent) + '"]<br>'; |
1166 | pgn += '[Black "' + (mycolor=='b'?'Myself':opponent) + '"]<br>'; | |
04449c97 BA |
1167 | pgn += '[FenStart "' + fenStart + '"]<br>'; |
1168 | pgn += '[Fen "' + this.getFen() + '"]<br>'; | |
762b7c9c | 1169 | pgn += '[Result "' + score + '"]<br><br>'; |
dfb4afc1 | 1170 | |
6752407b | 1171 | // Standard PGN |
dfb4afc1 BA |
1172 | for (let i=0; i<this.moves.length; i++) |
1173 | { | |
1174 | if (i % 2 == 0) | |
1175 | pgn += ((i/2)+1) + "."; | |
6752407b | 1176 | pgn += this.moves[i].notation[0] + " "; |
dfb4afc1 | 1177 | } |
97fc8bf7 | 1178 | pgn += "<br><br>"; |
dfb4afc1 | 1179 | |
6752407b BA |
1180 | // "Complete moves" PGN (helping in ambiguous cases) |
1181 | for (let i=0; i<this.moves.length; i++) | |
1182 | { | |
1183 | if (i % 2 == 0) | |
1184 | pgn += ((i/2)+1) + "."; | |
1185 | pgn += this.moves[i].notation[1] + " "; | |
1186 | } | |
6752407b | 1187 | |
dfb4afc1 BA |
1188 | return pgn; |
1189 | } | |
1d184b4c | 1190 | } |