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1d184b4c BA |
1 | class PiPo //Piece+Position |
2 | { | |
3 | // o: {piece[p], color[c], posX[x], posY[y]} | |
4 | constructor(o) | |
5 | { | |
6 | this.p = o.p; | |
7 | this.c = o.c; | |
8 | this.x = o.x; | |
9 | this.y = o.y; | |
10 | } | |
11 | } | |
12 | ||
13 | class Move | |
14 | { | |
15 | // o: {appear, vanish, [start,] [end,]} | |
16 | // appear,vanish = arrays of PiPo | |
17 | // start,end = coordinates to apply to trigger move visually (think castle) | |
18 | constructor(o) | |
19 | { | |
20 | this.appear = o.appear; | |
21 | this.vanish = o.vanish; | |
22 | this.start = !!o.start ? o.start : {x:o.vanish[0].x, y:o.vanish[0].y}; | |
23 | this.end = !!o.end ? o.end : {x:o.appear[0].x, y:o.appear[0].y}; | |
24 | } | |
25 | } | |
26 | ||
27 | // NOTE: x coords = top to bottom; y = left to right (from white player perspective) | |
28 | class ChessRules | |
29 | { | |
30 | // Path to pieces | |
31 | static getPpath(b) | |
32 | { | |
33 | return b; //usual pieces in pieces/ folder | |
34 | } | |
35 | // Turn "wb" into "B" (for FEN) | |
36 | static board2fen(b) | |
37 | { | |
38 | return b[0]=='w' ? b[1].toUpperCase() : b[1]; | |
39 | } | |
40 | // Turn "p" into "bp" (for board) | |
41 | static fen2board(f) | |
42 | { | |
43 | return f.charCodeAt()<=90 ? "w"+f.toLowerCase() : "b"+f; | |
44 | } | |
45 | ||
46 | ///////////////// | |
47 | // INITIALIZATION | |
48 | ||
d3334c3a | 49 | // fen == "position flags" |
dfb4afc1 | 50 | constructor(fen, moves) |
1d184b4c | 51 | { |
dfb4afc1 | 52 | this.moves = moves; |
1d184b4c | 53 | // Use fen string to initialize variables, flags and board |
1d184b4c | 54 | this.board = VariantRules.GetBoard(fen); |
2526c041 | 55 | this.setFlags(fen); |
ffbae57a | 56 | this.initVariables(fen); |
1d184b4c BA |
57 | } |
58 | ||
59 | initVariables(fen) | |
60 | { | |
61 | this.INIT_COL_KING = {'w':-1, 'b':-1}; | |
62 | this.INIT_COL_ROOK = {'w':[-1,-1], 'b':[-1,-1]}; | |
63 | this.kingPos = {'w':[-1,-1], 'b':[-1,-1]}; //respective squares of white and black king | |
64 | const fenParts = fen.split(" "); | |
65 | const position = fenParts[0].split("/"); | |
66 | for (let i=0; i<position.length; i++) | |
67 | { | |
6037f1d8 BA |
68 | let k = 0; //column index on board |
69 | for (let j=0; j<position[i].length; j++) | |
1d184b4c BA |
70 | { |
71 | switch (position[i].charAt(j)) | |
72 | { | |
73 | case 'k': | |
6037f1d8 BA |
74 | this.kingPos['b'] = [i,k]; |
75 | this.INIT_COL_KING['b'] = k; | |
1d184b4c BA |
76 | break; |
77 | case 'K': | |
6037f1d8 BA |
78 | this.kingPos['w'] = [i,k]; |
79 | this.INIT_COL_KING['w'] = k; | |
1d184b4c BA |
80 | break; |
81 | case 'r': | |
82 | if (this.INIT_COL_ROOK['b'][0] < 0) | |
6037f1d8 | 83 | this.INIT_COL_ROOK['b'][0] = k; |
1d184b4c | 84 | else |
6037f1d8 | 85 | this.INIT_COL_ROOK['b'][1] = k; |
1d184b4c BA |
86 | break; |
87 | case 'R': | |
88 | if (this.INIT_COL_ROOK['w'][0] < 0) | |
6037f1d8 | 89 | this.INIT_COL_ROOK['w'][0] = k; |
1d184b4c | 90 | else |
6037f1d8 | 91 | this.INIT_COL_ROOK['w'][1] = k; |
1d184b4c BA |
92 | break; |
93 | default: | |
94 | let num = parseInt(position[i].charAt(j)); | |
95 | if (!isNaN(num)) | |
6037f1d8 | 96 | k += (num-1); |
1d184b4c | 97 | } |
6037f1d8 | 98 | k++; |
1d184b4c BA |
99 | } |
100 | } | |
f3802fcd | 101 | const epSq = this.moves.length > 0 ? this.getEpSquare(this.lastMove) : undefined; |
1d184b4c | 102 | this.epSquares = [ epSq ]; |
1d184b4c BA |
103 | } |
104 | ||
105 | // Turn diagram fen into double array ["wb","wp","bk",...] | |
106 | static GetBoard(fen) | |
107 | { | |
108 | let rows = fen.split(" ")[0].split("/"); | |
46302e64 | 109 | const [sizeX,sizeY] = VariantRules.size; |
1d184b4c BA |
110 | let board = doubleArray(sizeX, sizeY, ""); |
111 | for (let i=0; i<rows.length; i++) | |
112 | { | |
113 | let j = 0; | |
114 | for (let indexInRow = 0; indexInRow < rows[i].length; indexInRow++) | |
115 | { | |
116 | let character = rows[i][indexInRow]; | |
117 | let num = parseInt(character); | |
118 | if (!isNaN(num)) | |
119 | j += num; //just shift j | |
120 | else //something at position i,j | |
121 | board[i][j++] = VariantRules.fen2board(character); | |
122 | } | |
123 | } | |
124 | return board; | |
125 | } | |
126 | ||
dda21a71 | 127 | // Extract (relevant) flags from fen |
2526c041 | 128 | setFlags(fen) |
1d184b4c BA |
129 | { |
130 | // white a-castle, h-castle, black a-castle, h-castle | |
2526c041 BA |
131 | this.castleFlags = {'w': new Array(2), 'b': new Array(2)}; |
132 | let flags = fen.split(" ")[1]; //flags right after position | |
1d184b4c | 133 | for (let i=0; i<4; i++) |
2526c041 | 134 | this.castleFlags[i < 2 ? 'w' : 'b'][i%2] = (flags.charAt(i) == '1'); |
1d184b4c BA |
135 | } |
136 | ||
137 | /////////////////// | |
138 | // GETTERS, SETTERS | |
139 | ||
1d184b4c BA |
140 | static get size() { return [8,8]; } |
141 | // Two next functions return 'undefined' if called on empty square | |
142 | getColor(i,j) { return this.board[i][j].charAt(0); } | |
143 | getPiece(i,j) { return this.board[i][j].charAt(1); } | |
144 | ||
145 | // Color | |
146 | getOppCol(color) { return color=="w" ? "b" : "w"; } | |
147 | ||
148 | get lastMove() { | |
149 | const L = this.moves.length; | |
150 | return L>0 ? this.moves[L-1] : null; | |
151 | } | |
152 | get turn() { | |
d3334c3a | 153 | return this.moves.length%2==0 ? 'w' : 'b'; |
1d184b4c BA |
154 | } |
155 | ||
156 | // Pieces codes | |
157 | static get PAWN() { return 'p'; } | |
158 | static get ROOK() { return 'r'; } | |
159 | static get KNIGHT() { return 'n'; } | |
160 | static get BISHOP() { return 'b'; } | |
161 | static get QUEEN() { return 'q'; } | |
162 | static get KING() { return 'k'; } | |
163 | ||
164 | // Empty square | |
165 | static get EMPTY() { return ''; } | |
166 | ||
167 | // Some pieces movements | |
168 | static get steps() { | |
169 | return { | |
170 | 'r': [ [-1,0],[1,0],[0,-1],[0,1] ], | |
171 | 'n': [ [-1,-2],[-1,2],[1,-2],[1,2],[-2,-1],[-2,1],[2,-1],[2,1] ], | |
172 | 'b': [ [-1,-1],[-1,1],[1,-1],[1,1] ], | |
1d184b4c BA |
173 | }; |
174 | } | |
175 | ||
2526c041 BA |
176 | // Aggregates flags into one object |
177 | get flags() { | |
178 | return this.castleFlags; | |
179 | } | |
180 | ||
181 | // Reverse operation | |
182 | parseFlags(flags) | |
183 | { | |
184 | this.castleFlags = flags; | |
185 | } | |
186 | ||
1d184b4c BA |
187 | // En-passant square, if any |
188 | getEpSquare(move) | |
189 | { | |
190 | const [sx,sy,ex] = [move.start.x,move.start.y,move.end.x]; | |
191 | if (this.getPiece(sx,sy) == VariantRules.PAWN && Math.abs(sx - ex) == 2) | |
192 | { | |
193 | return { | |
194 | x: (sx + ex)/2, | |
195 | y: sy | |
196 | }; | |
197 | } | |
198 | return undefined; //default | |
199 | } | |
200 | ||
dda21a71 | 201 | // Can thing on square1 take thing on square2 |
46302e64 | 202 | canTake([x1,y1], [x2,y2]) |
1d184b4c | 203 | { |
46302e64 | 204 | return this.getColor(x1,y1) != this.getColor(x2,y2); |
1d184b4c BA |
205 | } |
206 | ||
207 | /////////////////// | |
208 | // MOVES GENERATION | |
209 | ||
210 | // All possible moves from selected square (assumption: color is OK) | |
211 | getPotentialMovesFrom([x,y]) | |
212 | { | |
1d184b4c BA |
213 | switch (this.getPiece(x,y)) |
214 | { | |
215 | case VariantRules.PAWN: | |
46302e64 | 216 | return this.getPotentialPawnMoves([x,y]); |
1d184b4c | 217 | case VariantRules.ROOK: |
46302e64 | 218 | return this.getPotentialRookMoves([x,y]); |
1d184b4c | 219 | case VariantRules.KNIGHT: |
46302e64 | 220 | return this.getPotentialKnightMoves([x,y]); |
1d184b4c | 221 | case VariantRules.BISHOP: |
46302e64 | 222 | return this.getPotentialBishopMoves([x,y]); |
1d184b4c | 223 | case VariantRules.QUEEN: |
46302e64 | 224 | return this.getPotentialQueenMoves([x,y]); |
1d184b4c | 225 | case VariantRules.KING: |
46302e64 | 226 | return this.getPotentialKingMoves([x,y]); |
1d184b4c BA |
227 | } |
228 | } | |
229 | ||
230 | // Build a regular move from its initial and destination squares; tr: transformation | |
46302e64 | 231 | getBasicMove([sx,sy], [ex,ey], tr) |
1d184b4c | 232 | { |
2526c041 | 233 | let mv = new Move({ |
1d184b4c BA |
234 | appear: [ |
235 | new PiPo({ | |
236 | x: ex, | |
237 | y: ey, | |
46302e64 BA |
238 | c: !!tr ? tr.c : this.getColor(sx,sy), |
239 | p: !!tr ? tr.p : this.getPiece(sx,sy) | |
1d184b4c BA |
240 | }) |
241 | ], | |
242 | vanish: [ | |
243 | new PiPo({ | |
244 | x: sx, | |
245 | y: sy, | |
246 | c: this.getColor(sx,sy), | |
247 | p: this.getPiece(sx,sy) | |
248 | }) | |
249 | ] | |
250 | }); | |
251 | ||
252 | // The opponent piece disappears if we take it | |
253 | if (this.board[ex][ey] != VariantRules.EMPTY) | |
254 | { | |
255 | mv.vanish.push( | |
256 | new PiPo({ | |
257 | x: ex, | |
258 | y: ey, | |
259 | c: this.getColor(ex,ey), | |
260 | p: this.getPiece(ex,ey) | |
261 | }) | |
262 | ); | |
263 | } | |
264 | return mv; | |
265 | } | |
266 | ||
267 | // Generic method to find possible moves of non-pawn pieces ("sliding or jumping") | |
46302e64 | 268 | getSlideNJumpMoves([x,y], steps, oneStep) |
1d184b4c | 269 | { |
46302e64 | 270 | const color = this.getColor(x,y); |
2526c041 | 271 | let moves = []; |
46302e64 | 272 | const [sizeX,sizeY] = VariantRules.size; |
1d184b4c BA |
273 | outerLoop: |
274 | for (let step of steps) | |
275 | { | |
46302e64 BA |
276 | let i = x + step[0]; |
277 | let j = y + step[1]; | |
1221ac47 BA |
278 | while (i>=0 && i<sizeX && j>=0 && j<sizeY |
279 | && this.board[i][j] == VariantRules.EMPTY) | |
1d184b4c | 280 | { |
46302e64 | 281 | moves.push(this.getBasicMove([x,y], [i,j])); |
1d184b4c BA |
282 | if (oneStep !== undefined) |
283 | continue outerLoop; | |
284 | i += step[0]; | |
285 | j += step[1]; | |
286 | } | |
efb20746 | 287 | if (i>=0 && i<sizeX && j>=0 && j<sizeY && this.canTake([x,y], [i,j])) |
46302e64 | 288 | moves.push(this.getBasicMove([x,y], [i,j])); |
1d184b4c BA |
289 | } |
290 | return moves; | |
291 | } | |
292 | ||
dda21a71 | 293 | // What are the pawn moves from square x,y ? |
46302e64 | 294 | getPotentialPawnMoves([x,y]) |
1d184b4c | 295 | { |
2526c041 BA |
296 | const color = this.turn; |
297 | let moves = []; | |
298 | const V = VariantRules; | |
1221ac47 | 299 | const [sizeX,sizeY] = V.size; |
2526c041 | 300 | const shift = (color == "w" ? -1 : 1); |
cf130369 BA |
301 | const firstRank = (color == 'w' ? sizeX-1 : 0); |
302 | const startRank = (color == "w" ? sizeX-2 : 1); | |
303 | const lastRank = (color == "w" ? 0 : sizeX-1); | |
1d184b4c BA |
304 | |
305 | if (x+shift >= 0 && x+shift < sizeX && x+shift != lastRank) | |
306 | { | |
307 | // Normal moves | |
308 | if (this.board[x+shift][y] == V.EMPTY) | |
309 | { | |
46302e64 | 310 | moves.push(this.getBasicMove([x,y], [x+shift,y])); |
1221ac47 | 311 | // Next condition because variants with pawns on 1st rank allow them to jump |
2526c041 | 312 | if ([startRank,firstRank].includes(x) && this.board[x+2*shift][y] == V.EMPTY) |
1d184b4c BA |
313 | { |
314 | // Two squares jump | |
46302e64 | 315 | moves.push(this.getBasicMove([x,y], [x+2*shift,y])); |
1d184b4c BA |
316 | } |
317 | } | |
318 | // Captures | |
1221ac47 BA |
319 | if (y>0 && this.canTake([x,y], [x+shift,y-1]) |
320 | && this.board[x+shift][y-1] != V.EMPTY) | |
321 | { | |
46302e64 | 322 | moves.push(this.getBasicMove([x,y], [x+shift,y-1])); |
1221ac47 BA |
323 | } |
324 | if (y<sizeY-1 && 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 | 328 | } |
1d184b4c BA |
329 | } |
330 | ||
331 | if (x+shift == lastRank) | |
332 | { | |
333 | // Promotion | |
334 | let promotionPieces = [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN]; | |
335 | promotionPieces.forEach(p => { | |
336 | // Normal move | |
337 | if (this.board[x+shift][y] == V.EMPTY) | |
46302e64 | 338 | moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:p})); |
1d184b4c | 339 | // Captures |
1221ac47 BA |
340 | if (y>0 && this.canTake([x,y], [x+shift,y-1]) |
341 | && this.board[x+shift][y-1] != V.EMPTY) | |
342 | { | |
46302e64 | 343 | moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:color,p:p})); |
1221ac47 BA |
344 | } |
345 | if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1]) | |
346 | && this.board[x+shift][y+1] != V.EMPTY) | |
347 | { | |
46302e64 | 348 | moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:color,p:p})); |
1221ac47 | 349 | } |
1d184b4c BA |
350 | }); |
351 | } | |
352 | ||
353 | // En passant | |
354 | const Lep = this.epSquares.length; | |
355 | const epSquare = Lep>0 ? this.epSquares[Lep-1] : undefined; | |
356 | if (!!epSquare && epSquare.x == x+shift && Math.abs(epSquare.y - y) == 1) | |
357 | { | |
358 | let epStep = epSquare.y - y; | |
46302e64 | 359 | var enpassantMove = this.getBasicMove([x,y], [x+shift,y+epStep]); |
1d184b4c BA |
360 | enpassantMove.vanish.push({ |
361 | x: x, | |
362 | y: y+epStep, | |
363 | p: 'p', | |
364 | c: this.getColor(x,y+epStep) | |
365 | }); | |
366 | moves.push(enpassantMove); | |
367 | } | |
368 | ||
369 | return moves; | |
370 | } | |
371 | ||
372 | // What are the rook moves from square x,y ? | |
46302e64 | 373 | getPotentialRookMoves(sq) |
1d184b4c | 374 | { |
46302e64 | 375 | return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.ROOK]); |
1d184b4c BA |
376 | } |
377 | ||
378 | // What are the knight moves from square x,y ? | |
46302e64 | 379 | getPotentialKnightMoves(sq) |
1d184b4c | 380 | { |
46302e64 | 381 | return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.KNIGHT], "oneStep"); |
1d184b4c BA |
382 | } |
383 | ||
384 | // What are the bishop moves from square x,y ? | |
46302e64 | 385 | getPotentialBishopMoves(sq) |
1d184b4c | 386 | { |
46302e64 | 387 | return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.BISHOP]); |
1d184b4c BA |
388 | } |
389 | ||
390 | // What are the queen moves from square x,y ? | |
46302e64 | 391 | getPotentialQueenMoves(sq) |
1d184b4c | 392 | { |
a37076f1 BA |
393 | const V = VariantRules; |
394 | return this.getSlideNJumpMoves(sq, V.steps[V.ROOK].concat(V.steps[V.BISHOP])); | |
1d184b4c BA |
395 | } |
396 | ||
397 | // What are the king moves from square x,y ? | |
46302e64 | 398 | getPotentialKingMoves(sq) |
1d184b4c | 399 | { |
a37076f1 | 400 | const V = VariantRules; |
1d184b4c | 401 | // Initialize with normal moves |
a37076f1 BA |
402 | let moves = this.getSlideNJumpMoves(sq, |
403 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep"); | |
46302e64 | 404 | return moves.concat(this.getCastleMoves(sq)); |
1d184b4c BA |
405 | } |
406 | ||
46302e64 | 407 | getCastleMoves([x,y]) |
1d184b4c | 408 | { |
46302e64 | 409 | const c = this.getColor(x,y); |
c6052161 BA |
410 | const [sizeX,sizeY] = VariantRules.size; |
411 | if (x != (c=="w" ? sizeX-1 : 0) || y != this.INIT_COL_KING[c]) | |
1d184b4c BA |
412 | return []; //x isn't first rank, or king has moved (shortcut) |
413 | ||
414 | const V = VariantRules; | |
415 | ||
416 | // Castling ? | |
417 | const oppCol = this.getOppCol(c); | |
418 | let moves = []; | |
419 | let i = 0; | |
c6052161 | 420 | const finalSquares = [ [2,3], [sizeY-2,sizeY-3] ]; //king, then rook |
1d184b4c BA |
421 | castlingCheck: |
422 | for (let castleSide=0; castleSide < 2; castleSide++) //large, then small | |
423 | { | |
2526c041 | 424 | if (!this.castleFlags[c][castleSide]) |
1d184b4c BA |
425 | continue; |
426 | // If this code is reached, rooks and king are on initial position | |
427 | ||
428 | // Nothing on the path of the king (and no checks; OK also if y==finalSquare)? | |
429 | let step = finalSquares[castleSide][0] < y ? -1 : 1; | |
430 | for (i=y; i!=finalSquares[castleSide][0]; i+=step) | |
431 | { | |
cf130369 | 432 | if (this.isAttacked([x,i], [oppCol]) || (this.board[x][i] != V.EMPTY && |
1d184b4c BA |
433 | // NOTE: next check is enough, because of chessboard constraints |
434 | (this.getColor(x,i) != c || ![V.KING,V.ROOK].includes(this.getPiece(x,i))))) | |
435 | { | |
436 | continue castlingCheck; | |
437 | } | |
438 | } | |
439 | ||
440 | // Nothing on the path to the rook? | |
441 | step = castleSide == 0 ? -1 : 1; | |
442 | for (i = y + step; i != this.INIT_COL_ROOK[c][castleSide]; i += step) | |
443 | { | |
444 | if (this.board[x][i] != V.EMPTY) | |
445 | continue castlingCheck; | |
446 | } | |
447 | const rookPos = this.INIT_COL_ROOK[c][castleSide]; | |
448 | ||
449 | // Nothing on final squares, except maybe king and castling rook? | |
450 | for (i=0; i<2; i++) | |
451 | { | |
452 | if (this.board[x][finalSquares[castleSide][i]] != V.EMPTY && | |
453 | this.getPiece(x,finalSquares[castleSide][i]) != V.KING && | |
454 | finalSquares[castleSide][i] != rookPos) | |
455 | { | |
456 | continue castlingCheck; | |
457 | } | |
458 | } | |
459 | ||
460 | // If this code is reached, castle is valid | |
461 | moves.push( new Move({ | |
462 | appear: [ | |
463 | new PiPo({x:x,y:finalSquares[castleSide][0],p:V.KING,c:c}), | |
464 | new PiPo({x:x,y:finalSquares[castleSide][1],p:V.ROOK,c:c})], | |
465 | vanish: [ | |
466 | new PiPo({x:x,y:y,p:V.KING,c:c}), | |
467 | new PiPo({x:x,y:rookPos,p:V.ROOK,c:c})], | |
468 | end: Math.abs(y - rookPos) <= 2 | |
469 | ? {x:x, y:rookPos} | |
470 | : {x:x, y:y + 2 * (castleSide==0 ? -1 : 1)} | |
471 | }) ); | |
472 | } | |
473 | ||
474 | return moves; | |
475 | } | |
476 | ||
477 | /////////////////// | |
478 | // MOVES VALIDATION | |
479 | ||
46302e64 | 480 | canIplay(side, [x,y]) |
1d184b4c | 481 | { |
46302e64 BA |
482 | return ((side=='w' && this.moves.length%2==0) || (side=='b' && this.moves.length%2==1)) |
483 | && this.getColor(x,y) == side; | |
1d184b4c BA |
484 | } |
485 | ||
486 | getPossibleMovesFrom(sq) | |
487 | { | |
488 | // Assuming color is right (already checked) | |
489 | return this.filterValid( this.getPotentialMovesFrom(sq) ); | |
490 | } | |
491 | ||
492 | // TODO: once a promotion is filtered, the others results are same: useless computations | |
493 | filterValid(moves) | |
494 | { | |
495 | if (moves.length == 0) | |
496 | return []; | |
b8121223 | 497 | return moves.filter(m => { return !this.underCheck(m); }); |
1d184b4c BA |
498 | } |
499 | ||
500 | // Search for all valid moves considering current turn (for engine and game end) | |
46302e64 | 501 | getAllValidMoves() |
1d184b4c | 502 | { |
46302e64 | 503 | const color = this.turn; |
1d184b4c | 504 | const oppCol = this.getOppCol(color); |
c6052161 BA |
505 | let potentialMoves = []; |
506 | const [sizeX,sizeY] = VariantRules.size; | |
a6abf094 | 507 | for (let i=0; i<sizeX; i++) |
1d184b4c | 508 | { |
a6abf094 | 509 | for (let j=0; j<sizeY; j++) |
1d184b4c BA |
510 | { |
511 | // Next condition ... != oppCol is a little HACK to work with checkered variant | |
512 | if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) != oppCol) | |
513 | Array.prototype.push.apply(potentialMoves, this.getPotentialMovesFrom([i,j])); | |
514 | } | |
515 | } | |
516 | // NOTE: prefer lazy undercheck tests, letting the king being taken? | |
517 | // No: if happen on last 1/2 move, could lead to forbidden moves, wrong evals | |
518 | return this.filterValid(potentialMoves); | |
519 | } | |
9de73b71 | 520 | |
e64a4eff | 521 | // Stop at the first move found |
46302e64 | 522 | atLeastOneMove() |
e64a4eff | 523 | { |
46302e64 | 524 | const color = this.turn; |
e64a4eff | 525 | const oppCol = this.getOppCol(color); |
c6052161 | 526 | const [sizeX,sizeY] = VariantRules.size; |
9de73b71 | 527 | for (let i=0; i<sizeX; i++) |
e64a4eff | 528 | { |
9de73b71 | 529 | for (let j=0; j<sizeY; j++) |
e64a4eff BA |
530 | { |
531 | if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) != oppCol) | |
532 | { | |
533 | const moves = this.getPotentialMovesFrom([i,j]); | |
534 | if (moves.length > 0) | |
535 | { | |
9de73b71 | 536 | for (let k=0; k<moves.length; k++) |
e64a4eff | 537 | { |
9de73b71 | 538 | if (this.filterValid([moves[k]]).length > 0) |
e64a4eff BA |
539 | return true; |
540 | } | |
541 | } | |
542 | } | |
543 | } | |
544 | } | |
545 | return false; | |
546 | } | |
1d184b4c | 547 | |
dda21a71 | 548 | // Check if pieces of color in array 'colors' are attacking square x,y |
46302e64 | 549 | isAttacked(sq, colors) |
1d184b4c | 550 | { |
46302e64 BA |
551 | return (this.isAttackedByPawn(sq, colors) |
552 | || this.isAttackedByRook(sq, colors) | |
553 | || this.isAttackedByKnight(sq, colors) | |
554 | || this.isAttackedByBishop(sq, colors) | |
555 | || this.isAttackedByQueen(sq, colors) | |
556 | || this.isAttackedByKing(sq, colors)); | |
1d184b4c BA |
557 | } |
558 | ||
dda21a71 | 559 | // Is square x,y attacked by 'colors' pawns ? |
46302e64 | 560 | isAttackedByPawn([x,y], colors) |
1d184b4c | 561 | { |
efb20746 | 562 | const [sizeX,sizeY] = VariantRules.size; |
46302e64 | 563 | for (let c of colors) |
1d184b4c | 564 | { |
46302e64 | 565 | let pawnShift = (c=="w" ? 1 : -1); |
efb20746 | 566 | if (x+pawnShift>=0 && x+pawnShift<sizeX) |
1d184b4c | 567 | { |
46302e64 | 568 | for (let i of [-1,1]) |
1d184b4c | 569 | { |
efb20746 | 570 | if (y+i>=0 && y+i<sizeY && this.getPiece(x+pawnShift,y+i)==VariantRules.PAWN |
46302e64 BA |
571 | && this.getColor(x+pawnShift,y+i)==c) |
572 | { | |
573 | return true; | |
574 | } | |
1d184b4c BA |
575 | } |
576 | } | |
577 | } | |
578 | return false; | |
579 | } | |
580 | ||
dda21a71 | 581 | // Is square x,y attacked by 'colors' rooks ? |
46302e64 | 582 | isAttackedByRook(sq, colors) |
1d184b4c | 583 | { |
46302e64 | 584 | return this.isAttackedBySlideNJump(sq, colors, |
1d184b4c BA |
585 | VariantRules.ROOK, VariantRules.steps[VariantRules.ROOK]); |
586 | } | |
587 | ||
dda21a71 | 588 | // Is square x,y attacked by 'colors' knights ? |
46302e64 | 589 | isAttackedByKnight(sq, colors) |
1d184b4c | 590 | { |
46302e64 | 591 | return this.isAttackedBySlideNJump(sq, colors, |
1d184b4c BA |
592 | VariantRules.KNIGHT, VariantRules.steps[VariantRules.KNIGHT], "oneStep"); |
593 | } | |
594 | ||
dda21a71 | 595 | // Is square x,y attacked by 'colors' bishops ? |
46302e64 | 596 | isAttackedByBishop(sq, colors) |
1d184b4c | 597 | { |
46302e64 | 598 | return this.isAttackedBySlideNJump(sq, colors, |
1d184b4c BA |
599 | VariantRules.BISHOP, VariantRules.steps[VariantRules.BISHOP]); |
600 | } | |
601 | ||
dda21a71 | 602 | // Is square x,y attacked by 'colors' queens ? |
46302e64 | 603 | isAttackedByQueen(sq, colors) |
1d184b4c | 604 | { |
a37076f1 BA |
605 | const V = VariantRules; |
606 | return this.isAttackedBySlideNJump(sq, colors, V.QUEEN, | |
607 | V.steps[V.ROOK].concat(V.steps[V.BISHOP])); | |
1d184b4c BA |
608 | } |
609 | ||
dda21a71 | 610 | // Is square x,y attacked by 'colors' king(s) ? |
46302e64 | 611 | isAttackedByKing(sq, colors) |
1d184b4c | 612 | { |
a37076f1 BA |
613 | const V = VariantRules; |
614 | return this.isAttackedBySlideNJump(sq, colors, V.KING, | |
615 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep"); | |
1d184b4c BA |
616 | } |
617 | ||
1221ac47 | 618 | // Generic method for non-pawn pieces ("sliding or jumping"): |
dda21a71 | 619 | // is x,y attacked by a piece of color in array 'colors' ? |
46302e64 | 620 | isAttackedBySlideNJump([x,y], colors, piece, steps, oneStep) |
1d184b4c | 621 | { |
efb20746 | 622 | const [sizeX,sizeY] = VariantRules.size; |
1d184b4c BA |
623 | for (let step of steps) |
624 | { | |
625 | let rx = x+step[0], ry = y+step[1]; | |
efb20746 BA |
626 | while (rx>=0 && rx<sizeX && ry>=0 && ry<sizeY |
627 | && this.board[rx][ry] == VariantRules.EMPTY && !oneStep) | |
1d184b4c BA |
628 | { |
629 | rx += step[0]; | |
630 | ry += step[1]; | |
631 | } | |
efb20746 BA |
632 | if (rx>=0 && rx<sizeX && ry>=0 && ry<sizeY |
633 | && this.board[rx][ry] != VariantRules.EMPTY | |
46302e64 | 634 | && this.getPiece(rx,ry) == piece && colors.includes(this.getColor(rx,ry))) |
1d184b4c BA |
635 | { |
636 | return true; | |
637 | } | |
638 | } | |
639 | return false; | |
640 | } | |
641 | ||
dda21a71 | 642 | // Is current player under check after his move ? |
46302e64 | 643 | underCheck(move) |
1d184b4c | 644 | { |
46302e64 | 645 | const color = this.turn; |
1d184b4c | 646 | this.play(move); |
cf130369 | 647 | let res = this.isAttacked(this.kingPos[color], [this.getOppCol(color)]); |
1d184b4c BA |
648 | this.undo(move); |
649 | return res; | |
650 | } | |
651 | ||
dda21a71 | 652 | // On which squares is opponent under check after our move ? |
46302e64 | 653 | getCheckSquares(move) |
4b5fe306 BA |
654 | { |
655 | this.play(move); | |
204e289b | 656 | const color = this.turn; //opponent |
cf130369 | 657 | let res = this.isAttacked(this.kingPos[color], [this.getOppCol(color)]) |
46302e64 | 658 | ? [ JSON.parse(JSON.stringify(this.kingPos[color])) ] //need to duplicate! |
4b5fe306 BA |
659 | : [ ]; |
660 | this.undo(move); | |
661 | return res; | |
662 | } | |
663 | ||
1d184b4c BA |
664 | // Apply a move on board |
665 | static PlayOnBoard(board, move) | |
666 | { | |
667 | for (let psq of move.vanish) | |
668 | board[psq.x][psq.y] = VariantRules.EMPTY; | |
669 | for (let psq of move.appear) | |
670 | board[psq.x][psq.y] = psq.c + psq.p; | |
671 | } | |
672 | // Un-apply the played move | |
673 | static UndoOnBoard(board, move) | |
674 | { | |
675 | for (let psq of move.appear) | |
676 | board[psq.x][psq.y] = VariantRules.EMPTY; | |
677 | for (let psq of move.vanish) | |
678 | board[psq.x][psq.y] = psq.c + psq.p; | |
679 | } | |
680 | ||
d3334c3a | 681 | // Before move is played, update variables + flags |
1d184b4c BA |
682 | updateVariables(move) |
683 | { | |
684 | const piece = this.getPiece(move.start.x,move.start.y); | |
685 | const c = this.getColor(move.start.x,move.start.y); | |
c6052161 BA |
686 | const [sizeX,sizeY] = VariantRules.size; |
687 | const firstRank = (c == "w" ? sizeX-1 : 0); | |
1d184b4c BA |
688 | |
689 | // Update king position + flags | |
690 | if (piece == VariantRules.KING && move.appear.length > 0) | |
691 | { | |
692 | this.kingPos[c][0] = move.appear[0].x; | |
693 | this.kingPos[c][1] = move.appear[0].y; | |
2526c041 | 694 | this.castleFlags[c] = [false,false]; |
1d184b4c BA |
695 | return; |
696 | } | |
697 | const oppCol = this.getOppCol(c); | |
c6052161 | 698 | const oppFirstRank = (sizeX-1) - firstRank; |
1d184b4c BA |
699 | if (move.start.x == firstRank //our rook moves? |
700 | && this.INIT_COL_ROOK[c].includes(move.start.y)) | |
701 | { | |
2526c041 BA |
702 | const flagIdx = (move.start.y == this.INIT_COL_ROOK[c][0] ? 0 : 1); |
703 | this.castleFlags[c][flagIdx] = false; | |
1d184b4c BA |
704 | } |
705 | else if (move.end.x == oppFirstRank //we took opponent rook? | |
aea1443e | 706 | && this.INIT_COL_ROOK[oppCol].includes(move.end.y)) |
1d184b4c | 707 | { |
2526c041 BA |
708 | const flagIdx = (move.end.y == this.INIT_COL_ROOK[oppCol][0] ? 0 : 1); |
709 | this.castleFlags[oppCol][flagIdx] = false; | |
1d184b4c BA |
710 | } |
711 | } | |
712 | ||
dda21a71 BA |
713 | // After move is undo-ed, un-update variables (flags are reset) |
714 | // TODO: more symmetry, by storing flags increment in move... | |
d3334c3a | 715 | unupdateVariables(move) |
1d184b4c | 716 | { |
d3334c3a BA |
717 | // (Potentially) Reset king position |
718 | const c = this.getColor(move.start.x,move.start.y); | |
719 | if (this.getPiece(move.start.x,move.start.y) == VariantRules.KING) | |
720 | this.kingPos[c] = [move.start.x, move.start.y]; | |
721 | } | |
1d184b4c | 722 | |
d3334c3a BA |
723 | play(move, ingame) |
724 | { | |
dfb4afc1 | 725 | if (!!ingame) |
6752407b | 726 | move.notation = [this.getNotation(move), this.getLongNotation(move)]; |
dfb4afc1 | 727 | |
2526c041 | 728 | move.flags = JSON.stringify(this.flags); //save flags (for undo) |
d3334c3a BA |
729 | this.updateVariables(move); |
730 | this.moves.push(move); | |
1d184b4c BA |
731 | this.epSquares.push( this.getEpSquare(move) ); |
732 | VariantRules.PlayOnBoard(this.board, move); | |
1d184b4c BA |
733 | } |
734 | ||
cd4cad04 | 735 | undo(move) |
1d184b4c BA |
736 | { |
737 | VariantRules.UndoOnBoard(this.board, move); | |
738 | this.epSquares.pop(); | |
d3334c3a BA |
739 | this.moves.pop(); |
740 | this.unupdateVariables(move); | |
2526c041 | 741 | this.parseFlags(JSON.parse(move.flags)); |
1d184b4c BA |
742 | } |
743 | ||
744 | ////////////// | |
745 | // END OF GAME | |
746 | ||
dda21a71 | 747 | // Basic check for 3 repetitions (in the last moves only) |
1af36beb | 748 | checkRepetition() |
1d184b4c | 749 | { |
1d184b4c BA |
750 | if (this.moves.length >= 8) |
751 | { | |
1d184b4c BA |
752 | const L = this.moves.length; |
753 | if (_.isEqual(this.moves[L-1], this.moves[L-5]) && | |
754 | _.isEqual(this.moves[L-2], this.moves[L-6]) && | |
755 | _.isEqual(this.moves[L-3], this.moves[L-7]) && | |
756 | _.isEqual(this.moves[L-4], this.moves[L-8])) | |
757 | { | |
1af36beb | 758 | return true; |
1d184b4c BA |
759 | } |
760 | } | |
1af36beb BA |
761 | return false; |
762 | } | |
1d184b4c | 763 | |
dda21a71 | 764 | // Is game over ? And if yes, what is the score ? |
1af36beb BA |
765 | checkGameOver() |
766 | { | |
767 | if (this.checkRepetition()) | |
768 | return "1/2"; | |
769 | ||
770 | if (this.atLeastOneMove()) // game not over | |
1d184b4c | 771 | return "*"; |
1d184b4c BA |
772 | |
773 | // Game over | |
46302e64 | 774 | return this.checkGameEnd(); |
1d184b4c BA |
775 | } |
776 | ||
46302e64 BA |
777 | // No moves are possible: compute score |
778 | checkGameEnd() | |
1d184b4c | 779 | { |
46302e64 | 780 | const color = this.turn; |
1d184b4c | 781 | // No valid move: stalemate or checkmate? |
cf130369 | 782 | if (!this.isAttacked(this.kingPos[color], [this.getOppCol(color)])) |
1d184b4c BA |
783 | return "1/2"; |
784 | // OK, checkmate | |
785 | return color == "w" ? "0-1" : "1-0"; | |
786 | } | |
787 | ||
788 | //////// | |
789 | //ENGINE | |
790 | ||
791 | // Pieces values | |
792 | static get VALUES() { | |
793 | return { | |
794 | 'p': 1, | |
795 | 'r': 5, | |
796 | 'n': 3, | |
797 | 'b': 3, | |
798 | 'q': 9, | |
799 | 'k': 1000 | |
800 | }; | |
801 | } | |
802 | ||
9e42b4dd BA |
803 | static get INFINITY() { |
804 | return 9999; //"checkmate" (unreachable eval) | |
805 | } | |
806 | ||
807 | static get THRESHOLD_MATE() { | |
808 | // At this value or above, the game is over | |
809 | return VariantRules.INFINITY; | |
810 | } | |
811 | ||
3c09dc49 BA |
812 | static get SEARCH_DEPTH() { |
813 | return 3; //2 for high branching factor, 4 for small (Loser chess) | |
814 | } | |
815 | ||
1d184b4c | 816 | // Assumption: at least one legal move |
a6abf094 BA |
817 | // NOTE: works also for extinction chess because depth is 3... |
818 | getComputerMove() | |
1d184b4c | 819 | { |
3c09dc49 | 820 | this.shouldReturn = false; |
9e42b4dd | 821 | const maxeval = VariantRules.INFINITY; |
46302e64 | 822 | const color = this.turn; |
a6abf094 BA |
823 | let moves1 = this.getAllValidMoves(); |
824 | ||
825 | // Can I mate in 1 ? (for Magnetic & Extinction) | |
826 | for (let i of _.shuffle(_.range(moves1.length))) | |
827 | { | |
828 | this.play(moves1[i]); | |
829 | const finish = (Math.abs(this.evalPosition()) >= VariantRules.THRESHOLD_MATE); | |
830 | this.undo(moves1[i]); | |
831 | if (finish) | |
832 | return moves1[i]; | |
833 | } | |
1d184b4c | 834 | |
06ddfe34 | 835 | // Rank moves using a min-max at depth 2 |
1d184b4c BA |
836 | for (let i=0; i<moves1.length; i++) |
837 | { | |
9e42b4dd BA |
838 | moves1[i].eval = (color=="w" ? -1 : 1) * maxeval; //very low, I'm checkmated |
839 | let eval2 = (color=="w" ? 1 : -1) * maxeval; //initialized with checkmate value | |
1d184b4c BA |
840 | this.play(moves1[i]); |
841 | // Second half-move: | |
46302e64 | 842 | let moves2 = this.getAllValidMoves(); |
1d184b4c BA |
843 | // If no possible moves AND underCheck, eval2 is correct. |
844 | // If !underCheck, eval2 is 0 (stalemate). | |
46302e64 | 845 | if (moves2.length == 0 && this.checkGameEnd() == "1/2") |
1d184b4c BA |
846 | eval2 = 0; |
847 | for (let j=0; j<moves2.length; j++) | |
848 | { | |
849 | this.play(moves2[j]); | |
850 | let evalPos = this.evalPosition(); | |
851 | if ((color == "w" && evalPos < eval2) || (color=="b" && evalPos > eval2)) | |
852 | eval2 = evalPos; | |
853 | this.undo(moves2[j]); | |
854 | } | |
855 | if ((color=="w" && eval2 > moves1[i].eval) || (color=="b" && eval2 < moves1[i].eval)) | |
856 | moves1[i].eval = eval2; | |
857 | this.undo(moves1[i]); | |
858 | } | |
859 | moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); }); | |
860 | ||
3c09dc49 BA |
861 | let candidates = [0]; //indices of candidates moves |
862 | for (let j=1; j<moves1.length && moves1[j].eval == moves1[0].eval; j++) | |
863 | candidates.push(j); | |
864 | let currentBest = moves1[_.sample(candidates, 1)]; | |
865 | ||
a6abf094 | 866 | // Skip depth 3+ if we found a checkmate (or if we are checkmated in 1...) |
3c09dc49 BA |
867 | if (VariantRules.SEARCH_DEPTH >= 3 |
868 | && Math.abs(moves1[0].eval) < VariantRules.THRESHOLD_MATE) | |
e64a4eff | 869 | { |
9e42b4dd BA |
870 | for (let i=0; i<moves1.length; i++) |
871 | { | |
3c09dc49 BA |
872 | if (this.shouldReturn) |
873 | return currentBest; //depth-2, minimum | |
9e42b4dd BA |
874 | this.play(moves1[i]); |
875 | // 0.1 * oldEval : heuristic to avoid some bad moves (not all...) | |
3c09dc49 BA |
876 | moves1[i].eval = 0.1*moves1[i].eval + |
877 | this.alphabeta(VariantRules.SEARCH_DEPTH-1, -maxeval, maxeval); | |
9e42b4dd BA |
878 | this.undo(moves1[i]); |
879 | } | |
880 | moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); }); | |
e64a4eff | 881 | } |
3c09dc49 BA |
882 | else |
883 | return currentBest; | |
1d184b4c | 884 | |
3c09dc49 | 885 | candidates = [0]; |
1d184b4c BA |
886 | for (let j=1; j<moves1.length && moves1[j].eval == moves1[0].eval; j++) |
887 | candidates.push(j); | |
9de73b71 | 888 | // console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; })); |
1d184b4c BA |
889 | return moves1[_.sample(candidates, 1)]; |
890 | } | |
891 | ||
dda21a71 | 892 | // TODO: some optimisations, understand why CH get mated in 2 |
46302e64 | 893 | alphabeta(depth, alpha, beta) |
1d184b4c | 894 | { |
9e42b4dd | 895 | const maxeval = VariantRules.INFINITY; |
46302e64 BA |
896 | const color = this.turn; |
897 | if (!this.atLeastOneMove()) | |
1d184b4c | 898 | { |
46302e64 | 899 | switch (this.checkGameEnd()) |
1d184b4c BA |
900 | { |
901 | case "1/2": return 0; | |
9e42b4dd | 902 | default: return color=="w" ? -maxeval : maxeval; |
1d184b4c BA |
903 | } |
904 | } | |
905 | if (depth == 0) | |
906 | return this.evalPosition(); | |
46302e64 | 907 | const moves = this.getAllValidMoves(); |
9e42b4dd | 908 | let v = color=="w" ? -maxeval : maxeval; |
1d184b4c BA |
909 | if (color == "w") |
910 | { | |
911 | for (let i=0; i<moves.length; i++) | |
912 | { | |
913 | this.play(moves[i]); | |
46302e64 | 914 | v = Math.max(v, this.alphabeta(depth-1, alpha, beta)); |
1d184b4c BA |
915 | this.undo(moves[i]); |
916 | alpha = Math.max(alpha, v); | |
917 | if (alpha >= beta) | |
918 | break; //beta cutoff | |
919 | } | |
920 | } | |
921 | else //color=="b" | |
922 | { | |
923 | for (let i=0; i<moves.length; i++) | |
924 | { | |
925 | this.play(moves[i]); | |
46302e64 | 926 | v = Math.min(v, this.alphabeta(depth-1, alpha, beta)); |
1d184b4c BA |
927 | this.undo(moves[i]); |
928 | beta = Math.min(beta, v); | |
929 | if (alpha >= beta) | |
930 | break; //alpha cutoff | |
931 | } | |
932 | } | |
933 | return v; | |
934 | } | |
935 | ||
936 | evalPosition() | |
937 | { | |
938 | const [sizeX,sizeY] = VariantRules.size; | |
939 | let evaluation = 0; | |
a6abf094 | 940 | // Just count material for now |
1d184b4c BA |
941 | for (let i=0; i<sizeX; i++) |
942 | { | |
943 | for (let j=0; j<sizeY; j++) | |
944 | { | |
945 | if (this.board[i][j] != VariantRules.EMPTY) | |
946 | { | |
947 | const sign = this.getColor(i,j) == "w" ? 1 : -1; | |
948 | evaluation += sign * VariantRules.VALUES[this.getPiece(i,j)]; | |
949 | } | |
950 | } | |
951 | } | |
952 | return evaluation; | |
953 | } | |
954 | ||
955 | //////////// | |
956 | // FEN utils | |
957 | ||
dda21a71 | 958 | // Setup the initial random (assymetric) position |
1d184b4c BA |
959 | static GenRandInitFen() |
960 | { | |
961 | let pieces = [new Array(8), new Array(8)]; | |
962 | // Shuffle pieces on first and last rank | |
963 | for (let c = 0; c <= 1; c++) | |
964 | { | |
965 | let positions = _.range(8); | |
966 | ||
967 | // Get random squares for bishops | |
968 | let randIndex = 2 * _.random(3); | |
969 | let bishop1Pos = positions[randIndex]; | |
970 | // The second bishop must be on a square of different color | |
971 | let randIndex_tmp = 2 * _.random(3) + 1; | |
972 | let bishop2Pos = positions[randIndex_tmp]; | |
973 | // Remove chosen squares | |
974 | positions.splice(Math.max(randIndex,randIndex_tmp), 1); | |
975 | positions.splice(Math.min(randIndex,randIndex_tmp), 1); | |
976 | ||
977 | // Get random squares for knights | |
978 | randIndex = _.random(5); | |
979 | let knight1Pos = positions[randIndex]; | |
980 | positions.splice(randIndex, 1); | |
981 | randIndex = _.random(4); | |
982 | let knight2Pos = positions[randIndex]; | |
983 | positions.splice(randIndex, 1); | |
984 | ||
985 | // Get random square for queen | |
986 | randIndex = _.random(3); | |
987 | let queenPos = positions[randIndex]; | |
988 | positions.splice(randIndex, 1); | |
989 | ||
990 | // Rooks and king positions are now fixed, because of the ordering rook-king-rook | |
991 | let rook1Pos = positions[0]; | |
992 | let kingPos = positions[1]; | |
993 | let rook2Pos = positions[2]; | |
994 | ||
995 | // Finally put the shuffled pieces in the board array | |
996 | pieces[c][rook1Pos] = 'r'; | |
997 | pieces[c][knight1Pos] = 'n'; | |
998 | pieces[c][bishop1Pos] = 'b'; | |
999 | pieces[c][queenPos] = 'q'; | |
1000 | pieces[c][kingPos] = 'k'; | |
1001 | pieces[c][bishop2Pos] = 'b'; | |
1002 | pieces[c][knight2Pos] = 'n'; | |
1003 | pieces[c][rook2Pos] = 'r'; | |
1004 | } | |
1005 | let fen = pieces[0].join("") + | |
1006 | "/pppppppp/8/8/8/8/PPPPPPPP/" + | |
1007 | pieces[1].join("").toUpperCase() + | |
f3802fcd | 1008 | " 1111"; //add flags |
1d184b4c BA |
1009 | return fen; |
1010 | } | |
1011 | ||
1012 | // Return current fen according to pieces+colors state | |
1013 | getFen() | |
1014 | { | |
f3802fcd | 1015 | return this.getBaseFen() + " " + this.getFlagsFen(); |
1d184b4c BA |
1016 | } |
1017 | ||
dda21a71 | 1018 | // Position part of the FEN string |
1d184b4c BA |
1019 | getBaseFen() |
1020 | { | |
1021 | let fen = ""; | |
1022 | let [sizeX,sizeY] = VariantRules.size; | |
1023 | for (let i=0; i<sizeX; i++) | |
1024 | { | |
1025 | let emptyCount = 0; | |
1026 | for (let j=0; j<sizeY; j++) | |
1027 | { | |
1028 | if (this.board[i][j] == VariantRules.EMPTY) | |
1029 | emptyCount++; | |
1030 | else | |
1031 | { | |
1032 | if (emptyCount > 0) | |
1033 | { | |
1034 | // Add empty squares in-between | |
1035 | fen += emptyCount; | |
1036 | emptyCount = 0; | |
1037 | } | |
1038 | fen += VariantRules.board2fen(this.board[i][j]); | |
1039 | } | |
1040 | } | |
1041 | if (emptyCount > 0) | |
1042 | { | |
1043 | // "Flush remainder" | |
1044 | fen += emptyCount; | |
1045 | } | |
1046 | if (i < sizeX - 1) | |
1047 | fen += "/"; //separate rows | |
1048 | } | |
1049 | return fen; | |
1050 | } | |
1051 | ||
dda21a71 | 1052 | // Flags part of the FEN string |
1d184b4c BA |
1053 | getFlagsFen() |
1054 | { | |
1055 | let fen = ""; | |
1056 | // Add castling flags | |
1057 | for (let i of ['w','b']) | |
1058 | { | |
1059 | for (let j=0; j<2; j++) | |
2526c041 | 1060 | fen += this.castleFlags[i][j] ? '1' : '0'; |
1d184b4c BA |
1061 | } |
1062 | return fen; | |
1063 | } | |
1064 | ||
1065 | // Context: just before move is played, turn hasn't changed | |
1066 | getNotation(move) | |
1067 | { | |
aea1443e | 1068 | if (move.appear.length == 2 && move.appear[0].p == VariantRules.KING) |
1d184b4c BA |
1069 | { |
1070 | // Castle | |
1071 | if (move.end.y < move.start.y) | |
1072 | return "0-0-0"; | |
1073 | else | |
1074 | return "0-0"; | |
1075 | } | |
1076 | ||
1077 | // Translate final square | |
270968d6 | 1078 | const finalSquare = |
1d184b4c BA |
1079 | String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x); |
1080 | ||
270968d6 | 1081 | const piece = this.getPiece(move.start.x, move.start.y); |
1d184b4c BA |
1082 | if (piece == VariantRules.PAWN) |
1083 | { | |
1084 | // Pawn move | |
1085 | let notation = ""; | |
5bfb0956 | 1086 | if (move.vanish.length > move.appear.length) |
1d184b4c BA |
1087 | { |
1088 | // Capture | |
270968d6 | 1089 | const startColumn = String.fromCharCode(97 + move.start.y); |
1d184b4c BA |
1090 | notation = startColumn + "x" + finalSquare; |
1091 | } | |
1092 | else //no capture | |
1093 | notation = finalSquare; | |
1094 | if (move.appear.length > 0 && piece != move.appear[0].p) //promotion | |
1095 | notation += "=" + move.appear[0].p.toUpperCase(); | |
1096 | return notation; | |
1097 | } | |
1098 | ||
1099 | else | |
1100 | { | |
1101 | // Piece movement | |
f3c10e18 BA |
1102 | return piece.toUpperCase() + |
1103 | (move.vanish.length > move.appear.length ? "x" : "") + finalSquare; | |
1d184b4c BA |
1104 | } |
1105 | } | |
dfb4afc1 | 1106 | |
6752407b BA |
1107 | // Complete the usual notation, may be required for de-ambiguification |
1108 | getLongNotation(move) | |
1109 | { | |
1110 | const startSquare = | |
1111 | String.fromCharCode(97 + move.start.y) + (VariantRules.size[0]-move.start.x); | |
1112 | const finalSquare = | |
1113 | String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x); | |
1114 | return startSquare + finalSquare; //not encoding move. But short+long is enough | |
1115 | } | |
1116 | ||
dfb4afc1 | 1117 | // The score is already computed when calling this function |
01a135e2 | 1118 | getPGN(mycolor, score, fenStart, mode) |
dfb4afc1 BA |
1119 | { |
1120 | let pgn = ""; | |
1121 | pgn += '[Site "vchess.club"]<br>'; | |
1122 | const d = new Date(); | |
5e622704 | 1123 | const opponent = mode=="human" ? "Anonymous" : "Computer"; |
0f51ef98 | 1124 | pgn += '[Variant "' + variant + '"]<br>'; |
f61349e6 | 1125 | pgn += '[Date "' + d.getFullYear() + '-' + (d.getMonth()+1) + '-' + d.getDate() + '"]<br>'; |
01a135e2 BA |
1126 | pgn += '[White "' + (mycolor=='w'?'Myself':opponent) + '"]<br>'; |
1127 | pgn += '[Black "' + (mycolor=='b'?'Myself':opponent) + '"]<br>'; | |
762b7c9c BA |
1128 | pgn += '[Fen "' + fenStart + '"]<br>'; |
1129 | pgn += '[Result "' + score + '"]<br><br>'; | |
dfb4afc1 | 1130 | |
6752407b | 1131 | // Standard PGN |
dfb4afc1 BA |
1132 | for (let i=0; i<this.moves.length; i++) |
1133 | { | |
1134 | if (i % 2 == 0) | |
1135 | pgn += ((i/2)+1) + "."; | |
6752407b | 1136 | pgn += this.moves[i].notation[0] + " "; |
dfb4afc1 | 1137 | } |
6752407b | 1138 | pgn += score + "<br><br>"; |
dfb4afc1 | 1139 | |
6752407b BA |
1140 | // "Complete moves" PGN (helping in ambiguous cases) |
1141 | for (let i=0; i<this.moves.length; i++) | |
1142 | { | |
1143 | if (i % 2 == 0) | |
1144 | pgn += ((i/2)+1) + "."; | |
1145 | pgn += this.moves[i].notation[1] + " "; | |
1146 | } | |
dfb4afc1 | 1147 | pgn += score; |
6752407b | 1148 | |
dfb4afc1 BA |
1149 | return pgn; |
1150 | } | |
1d184b4c | 1151 | } |