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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 | ||
127 | // Overridable: flags can change a lot | |
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 | ||
140 | // Simple useful getters | |
141 | static get size() { return [8,8]; } | |
142 | // Two next functions return 'undefined' if called on empty square | |
143 | getColor(i,j) { return this.board[i][j].charAt(0); } | |
144 | getPiece(i,j) { return this.board[i][j].charAt(1); } | |
145 | ||
146 | // Color | |
147 | getOppCol(color) { return color=="w" ? "b" : "w"; } | |
148 | ||
149 | get lastMove() { | |
150 | const L = this.moves.length; | |
151 | return L>0 ? this.moves[L-1] : null; | |
152 | } | |
153 | get turn() { | |
d3334c3a | 154 | return this.moves.length%2==0 ? 'w' : 'b'; |
1d184b4c BA |
155 | } |
156 | ||
157 | // Pieces codes | |
158 | static get PAWN() { return 'p'; } | |
159 | static get ROOK() { return 'r'; } | |
160 | static get KNIGHT() { return 'n'; } | |
161 | static get BISHOP() { return 'b'; } | |
162 | static get QUEEN() { return 'q'; } | |
163 | static get KING() { return 'k'; } | |
164 | ||
165 | // Empty square | |
166 | static get EMPTY() { return ''; } | |
167 | ||
168 | // Some pieces movements | |
169 | static get steps() { | |
170 | return { | |
171 | 'r': [ [-1,0],[1,0],[0,-1],[0,1] ], | |
172 | 'n': [ [-1,-2],[-1,2],[1,-2],[1,2],[-2,-1],[-2,1],[2,-1],[2,1] ], | |
173 | 'b': [ [-1,-1],[-1,1],[1,-1],[1,1] ], | |
1d184b4c BA |
174 | }; |
175 | } | |
176 | ||
2526c041 BA |
177 | // Aggregates flags into one object |
178 | get flags() { | |
179 | return this.castleFlags; | |
180 | } | |
181 | ||
182 | // Reverse operation | |
183 | parseFlags(flags) | |
184 | { | |
185 | this.castleFlags = flags; | |
186 | } | |
187 | ||
1d184b4c BA |
188 | // En-passant square, if any |
189 | getEpSquare(move) | |
190 | { | |
191 | const [sx,sy,ex] = [move.start.x,move.start.y,move.end.x]; | |
192 | if (this.getPiece(sx,sy) == VariantRules.PAWN && Math.abs(sx - ex) == 2) | |
193 | { | |
194 | return { | |
195 | x: (sx + ex)/2, | |
196 | y: sy | |
197 | }; | |
198 | } | |
199 | return undefined; //default | |
200 | } | |
201 | ||
46302e64 BA |
202 | // can thing on square1 take thing on square2 |
203 | canTake([x1,y1], [x2,y2]) | |
1d184b4c | 204 | { |
46302e64 | 205 | return this.getColor(x1,y1) != this.getColor(x2,y2); |
1d184b4c BA |
206 | } |
207 | ||
208 | /////////////////// | |
209 | // MOVES GENERATION | |
210 | ||
211 | // All possible moves from selected square (assumption: color is OK) | |
212 | getPotentialMovesFrom([x,y]) | |
213 | { | |
1d184b4c BA |
214 | switch (this.getPiece(x,y)) |
215 | { | |
216 | case VariantRules.PAWN: | |
46302e64 | 217 | return this.getPotentialPawnMoves([x,y]); |
1d184b4c | 218 | case VariantRules.ROOK: |
46302e64 | 219 | return this.getPotentialRookMoves([x,y]); |
1d184b4c | 220 | case VariantRules.KNIGHT: |
46302e64 | 221 | return this.getPotentialKnightMoves([x,y]); |
1d184b4c | 222 | case VariantRules.BISHOP: |
46302e64 | 223 | return this.getPotentialBishopMoves([x,y]); |
1d184b4c | 224 | case VariantRules.QUEEN: |
46302e64 | 225 | return this.getPotentialQueenMoves([x,y]); |
1d184b4c | 226 | case VariantRules.KING: |
46302e64 | 227 | return this.getPotentialKingMoves([x,y]); |
1d184b4c BA |
228 | } |
229 | } | |
230 | ||
231 | // Build a regular move from its initial and destination squares; tr: transformation | |
46302e64 | 232 | getBasicMove([sx,sy], [ex,ey], tr) |
1d184b4c | 233 | { |
2526c041 | 234 | let mv = new Move({ |
1d184b4c BA |
235 | appear: [ |
236 | new PiPo({ | |
237 | x: ex, | |
238 | y: ey, | |
46302e64 BA |
239 | c: !!tr ? tr.c : this.getColor(sx,sy), |
240 | p: !!tr ? tr.p : this.getPiece(sx,sy) | |
1d184b4c BA |
241 | }) |
242 | ], | |
243 | vanish: [ | |
244 | new PiPo({ | |
245 | x: sx, | |
246 | y: sy, | |
247 | c: this.getColor(sx,sy), | |
248 | p: this.getPiece(sx,sy) | |
249 | }) | |
250 | ] | |
251 | }); | |
252 | ||
253 | // The opponent piece disappears if we take it | |
254 | if (this.board[ex][ey] != VariantRules.EMPTY) | |
255 | { | |
256 | mv.vanish.push( | |
257 | new PiPo({ | |
258 | x: ex, | |
259 | y: ey, | |
260 | c: this.getColor(ex,ey), | |
261 | p: this.getPiece(ex,ey) | |
262 | }) | |
263 | ); | |
264 | } | |
265 | return mv; | |
266 | } | |
267 | ||
268 | // Generic method to find possible moves of non-pawn pieces ("sliding or jumping") | |
46302e64 | 269 | getSlideNJumpMoves([x,y], steps, oneStep) |
1d184b4c | 270 | { |
46302e64 | 271 | const color = this.getColor(x,y); |
2526c041 | 272 | let moves = []; |
46302e64 | 273 | const [sizeX,sizeY] = VariantRules.size; |
1d184b4c BA |
274 | outerLoop: |
275 | for (let step of steps) | |
276 | { | |
46302e64 BA |
277 | let i = x + step[0]; |
278 | let j = y + step[1]; | |
818ede16 | 279 | while (i>=0 && i<sizeX && j>=0 && j<sizeY && 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 | } | |
46302e64 BA |
287 | if (i>=0 && i<8 && j>=0 && j<8 && this.canTake([x,y], [i,j])) |
288 | moves.push(this.getBasicMove([x,y], [i,j])); | |
1d184b4c BA |
289 | } |
290 | return moves; | |
291 | } | |
292 | ||
293 | // What are the pawn moves from square x,y considering color "color" ? | |
46302e64 | 294 | getPotentialPawnMoves([x,y]) |
1d184b4c | 295 | { |
2526c041 BA |
296 | const color = this.turn; |
297 | let moves = []; | |
298 | const V = VariantRules; | |
46302e64 | 299 | const [sizeX,sizeY] = VariantRules.size; |
2526c041 BA |
300 | const shift = (color == "w" ? -1 : 1); |
301 | const firstRank = (color == 'w' ? sizeY-1 : 0); | |
302 | const startRank = (color == "w" ? sizeY-2 : 1); | |
303 | const lastRank = (color == "w" ? 0 : sizeY-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])); |
2526c041 BA |
311 | // Next condition because variants with pawns on 1st rank generally allow them to jump |
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 | |
46302e64 BA |
319 | if (y>0 && this.canTake([x,y], [x+shift,y-1]) && this.board[x+shift][y-1] != V.EMPTY) |
320 | moves.push(this.getBasicMove([x,y], [x+shift,y-1])); | |
321 | if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1]) && this.board[x+shift][y+1] != V.EMPTY) | |
322 | moves.push(this.getBasicMove([x,y], [x+shift,y+1])); | |
1d184b4c BA |
323 | } |
324 | ||
325 | if (x+shift == lastRank) | |
326 | { | |
327 | // Promotion | |
328 | let promotionPieces = [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN]; | |
329 | promotionPieces.forEach(p => { | |
330 | // Normal move | |
331 | if (this.board[x+shift][y] == V.EMPTY) | |
46302e64 | 332 | moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:p})); |
1d184b4c | 333 | // Captures |
46302e64 BA |
334 | if (y>0 && this.canTake([x,y], [x+shift,y-1]) && this.board[x+shift][y-1] != V.EMPTY) |
335 | moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:color,p:p})); | |
336 | if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1]) && this.board[x+shift][y+1] != V.EMPTY) | |
337 | moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:color,p:p})); | |
1d184b4c BA |
338 | }); |
339 | } | |
340 | ||
341 | // En passant | |
342 | const Lep = this.epSquares.length; | |
343 | const epSquare = Lep>0 ? this.epSquares[Lep-1] : undefined; | |
344 | if (!!epSquare && epSquare.x == x+shift && Math.abs(epSquare.y - y) == 1) | |
345 | { | |
346 | let epStep = epSquare.y - y; | |
46302e64 | 347 | var enpassantMove = this.getBasicMove([x,y], [x+shift,y+epStep]); |
1d184b4c BA |
348 | enpassantMove.vanish.push({ |
349 | x: x, | |
350 | y: y+epStep, | |
351 | p: 'p', | |
352 | c: this.getColor(x,y+epStep) | |
353 | }); | |
354 | moves.push(enpassantMove); | |
355 | } | |
356 | ||
357 | return moves; | |
358 | } | |
359 | ||
360 | // What are the rook moves from square x,y ? | |
46302e64 | 361 | getPotentialRookMoves(sq) |
1d184b4c | 362 | { |
46302e64 | 363 | return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.ROOK]); |
1d184b4c BA |
364 | } |
365 | ||
366 | // What are the knight moves from square x,y ? | |
46302e64 | 367 | getPotentialKnightMoves(sq) |
1d184b4c | 368 | { |
46302e64 | 369 | return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.KNIGHT], "oneStep"); |
1d184b4c BA |
370 | } |
371 | ||
372 | // What are the bishop moves from square x,y ? | |
46302e64 | 373 | getPotentialBishopMoves(sq) |
1d184b4c | 374 | { |
46302e64 | 375 | return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.BISHOP]); |
1d184b4c BA |
376 | } |
377 | ||
378 | // What are the queen moves from square x,y ? | |
46302e64 | 379 | getPotentialQueenMoves(sq) |
1d184b4c | 380 | { |
a37076f1 BA |
381 | const V = VariantRules; |
382 | return this.getSlideNJumpMoves(sq, V.steps[V.ROOK].concat(V.steps[V.BISHOP])); | |
1d184b4c BA |
383 | } |
384 | ||
385 | // What are the king moves from square x,y ? | |
46302e64 | 386 | getPotentialKingMoves(sq) |
1d184b4c | 387 | { |
a37076f1 | 388 | const V = VariantRules; |
1d184b4c | 389 | // Initialize with normal moves |
a37076f1 BA |
390 | let moves = this.getSlideNJumpMoves(sq, |
391 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep"); | |
46302e64 | 392 | return moves.concat(this.getCastleMoves(sq)); |
1d184b4c BA |
393 | } |
394 | ||
46302e64 | 395 | getCastleMoves([x,y]) |
1d184b4c | 396 | { |
46302e64 | 397 | const c = this.getColor(x,y); |
1d184b4c BA |
398 | if (x != (c=="w" ? 7 : 0) || y != this.INIT_COL_KING[c]) |
399 | return []; //x isn't first rank, or king has moved (shortcut) | |
400 | ||
401 | const V = VariantRules; | |
402 | ||
403 | // Castling ? | |
404 | const oppCol = this.getOppCol(c); | |
405 | let moves = []; | |
406 | let i = 0; | |
407 | const finalSquares = [ [2,3], [6,5] ]; //king, then rook | |
408 | castlingCheck: | |
409 | for (let castleSide=0; castleSide < 2; castleSide++) //large, then small | |
410 | { | |
2526c041 | 411 | if (!this.castleFlags[c][castleSide]) |
1d184b4c BA |
412 | continue; |
413 | // If this code is reached, rooks and king are on initial position | |
414 | ||
415 | // Nothing on the path of the king (and no checks; OK also if y==finalSquare)? | |
416 | let step = finalSquares[castleSide][0] < y ? -1 : 1; | |
417 | for (i=y; i!=finalSquares[castleSide][0]; i+=step) | |
418 | { | |
419 | if (this.isAttacked([x,i], oppCol) || (this.board[x][i] != V.EMPTY && | |
420 | // NOTE: next check is enough, because of chessboard constraints | |
421 | (this.getColor(x,i) != c || ![V.KING,V.ROOK].includes(this.getPiece(x,i))))) | |
422 | { | |
423 | continue castlingCheck; | |
424 | } | |
425 | } | |
426 | ||
427 | // Nothing on the path to the rook? | |
428 | step = castleSide == 0 ? -1 : 1; | |
429 | for (i = y + step; i != this.INIT_COL_ROOK[c][castleSide]; i += step) | |
430 | { | |
431 | if (this.board[x][i] != V.EMPTY) | |
432 | continue castlingCheck; | |
433 | } | |
434 | const rookPos = this.INIT_COL_ROOK[c][castleSide]; | |
435 | ||
436 | // Nothing on final squares, except maybe king and castling rook? | |
437 | for (i=0; i<2; i++) | |
438 | { | |
439 | if (this.board[x][finalSquares[castleSide][i]] != V.EMPTY && | |
440 | this.getPiece(x,finalSquares[castleSide][i]) != V.KING && | |
441 | finalSquares[castleSide][i] != rookPos) | |
442 | { | |
443 | continue castlingCheck; | |
444 | } | |
445 | } | |
446 | ||
447 | // If this code is reached, castle is valid | |
448 | moves.push( new Move({ | |
449 | appear: [ | |
450 | new PiPo({x:x,y:finalSquares[castleSide][0],p:V.KING,c:c}), | |
451 | new PiPo({x:x,y:finalSquares[castleSide][1],p:V.ROOK,c:c})], | |
452 | vanish: [ | |
453 | new PiPo({x:x,y:y,p:V.KING,c:c}), | |
454 | new PiPo({x:x,y:rookPos,p:V.ROOK,c:c})], | |
455 | end: Math.abs(y - rookPos) <= 2 | |
456 | ? {x:x, y:rookPos} | |
457 | : {x:x, y:y + 2 * (castleSide==0 ? -1 : 1)} | |
458 | }) ); | |
459 | } | |
460 | ||
461 | return moves; | |
462 | } | |
463 | ||
464 | /////////////////// | |
465 | // MOVES VALIDATION | |
466 | ||
46302e64 | 467 | canIplay(side, [x,y]) |
1d184b4c | 468 | { |
46302e64 BA |
469 | return ((side=='w' && this.moves.length%2==0) || (side=='b' && this.moves.length%2==1)) |
470 | && this.getColor(x,y) == side; | |
1d184b4c BA |
471 | } |
472 | ||
473 | getPossibleMovesFrom(sq) | |
474 | { | |
475 | // Assuming color is right (already checked) | |
476 | return this.filterValid( this.getPotentialMovesFrom(sq) ); | |
477 | } | |
478 | ||
479 | // TODO: once a promotion is filtered, the others results are same: useless computations | |
480 | filterValid(moves) | |
481 | { | |
482 | if (moves.length == 0) | |
483 | return []; | |
b8121223 | 484 | return moves.filter(m => { return !this.underCheck(m); }); |
1d184b4c BA |
485 | } |
486 | ||
487 | // Search for all valid moves considering current turn (for engine and game end) | |
46302e64 | 488 | getAllValidMoves() |
1d184b4c | 489 | { |
46302e64 | 490 | const color = this.turn; |
1d184b4c BA |
491 | const oppCol = this.getOppCol(color); |
492 | var potentialMoves = []; | |
493 | let [sizeX,sizeY] = VariantRules.size; | |
494 | for (var i=0; i<sizeX; i++) | |
495 | { | |
496 | for (var j=0; j<sizeY; j++) | |
497 | { | |
498 | // Next condition ... != oppCol is a little HACK to work with checkered variant | |
499 | if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) != oppCol) | |
500 | Array.prototype.push.apply(potentialMoves, this.getPotentialMovesFrom([i,j])); | |
501 | } | |
502 | } | |
503 | // NOTE: prefer lazy undercheck tests, letting the king being taken? | |
504 | // No: if happen on last 1/2 move, could lead to forbidden moves, wrong evals | |
505 | return this.filterValid(potentialMoves); | |
506 | } | |
9de73b71 | 507 | |
e64a4eff | 508 | // Stop at the first move found |
46302e64 | 509 | atLeastOneMove() |
e64a4eff | 510 | { |
46302e64 | 511 | const color = this.turn; |
e64a4eff BA |
512 | const oppCol = this.getOppCol(color); |
513 | let [sizeX,sizeY] = VariantRules.size; | |
9de73b71 | 514 | for (let i=0; i<sizeX; i++) |
e64a4eff | 515 | { |
9de73b71 | 516 | for (let j=0; j<sizeY; j++) |
e64a4eff BA |
517 | { |
518 | if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) != oppCol) | |
519 | { | |
520 | const moves = this.getPotentialMovesFrom([i,j]); | |
521 | if (moves.length > 0) | |
522 | { | |
9de73b71 | 523 | for (let k=0; k<moves.length; k++) |
e64a4eff | 524 | { |
9de73b71 | 525 | if (this.filterValid([moves[k]]).length > 0) |
e64a4eff BA |
526 | return true; |
527 | } | |
528 | } | |
529 | } | |
530 | } | |
531 | } | |
532 | return false; | |
533 | } | |
1d184b4c | 534 | |
46302e64 BA |
535 | // Check if pieces of color 'colors' are attacking square x,y |
536 | isAttacked(sq, colors) | |
1d184b4c | 537 | { |
46302e64 BA |
538 | return (this.isAttackedByPawn(sq, colors) |
539 | || this.isAttackedByRook(sq, colors) | |
540 | || this.isAttackedByKnight(sq, colors) | |
541 | || this.isAttackedByBishop(sq, colors) | |
542 | || this.isAttackedByQueen(sq, colors) | |
543 | || this.isAttackedByKing(sq, colors)); | |
1d184b4c BA |
544 | } |
545 | ||
546 | // Is square x,y attacked by pawns of color c ? | |
46302e64 | 547 | isAttackedByPawn([x,y], colors) |
1d184b4c | 548 | { |
46302e64 | 549 | for (let c of colors) |
1d184b4c | 550 | { |
46302e64 BA |
551 | let pawnShift = (c=="w" ? 1 : -1); |
552 | if (x+pawnShift>=0 && x+pawnShift<8) | |
1d184b4c | 553 | { |
46302e64 | 554 | for (let i of [-1,1]) |
1d184b4c | 555 | { |
46302e64 BA |
556 | if (y+i>=0 && y+i<8 && this.getPiece(x+pawnShift,y+i)==VariantRules.PAWN |
557 | && this.getColor(x+pawnShift,y+i)==c) | |
558 | { | |
559 | return true; | |
560 | } | |
1d184b4c BA |
561 | } |
562 | } | |
563 | } | |
564 | return false; | |
565 | } | |
566 | ||
567 | // Is square x,y attacked by rooks of color c ? | |
46302e64 | 568 | isAttackedByRook(sq, colors) |
1d184b4c | 569 | { |
46302e64 | 570 | return this.isAttackedBySlideNJump(sq, colors, |
1d184b4c BA |
571 | VariantRules.ROOK, VariantRules.steps[VariantRules.ROOK]); |
572 | } | |
573 | ||
574 | // Is square x,y attacked by knights of color c ? | |
46302e64 | 575 | isAttackedByKnight(sq, colors) |
1d184b4c | 576 | { |
46302e64 | 577 | return this.isAttackedBySlideNJump(sq, colors, |
1d184b4c BA |
578 | VariantRules.KNIGHT, VariantRules.steps[VariantRules.KNIGHT], "oneStep"); |
579 | } | |
580 | ||
581 | // Is square x,y attacked by bishops of color c ? | |
46302e64 | 582 | isAttackedByBishop(sq, colors) |
1d184b4c | 583 | { |
46302e64 | 584 | return this.isAttackedBySlideNJump(sq, colors, |
1d184b4c BA |
585 | VariantRules.BISHOP, VariantRules.steps[VariantRules.BISHOP]); |
586 | } | |
587 | ||
588 | // Is square x,y attacked by queens of color c ? | |
46302e64 | 589 | isAttackedByQueen(sq, colors) |
1d184b4c | 590 | { |
a37076f1 BA |
591 | const V = VariantRules; |
592 | return this.isAttackedBySlideNJump(sq, colors, V.QUEEN, | |
593 | V.steps[V.ROOK].concat(V.steps[V.BISHOP])); | |
1d184b4c BA |
594 | } |
595 | ||
596 | // Is square x,y attacked by king of color c ? | |
46302e64 | 597 | isAttackedByKing(sq, colors) |
1d184b4c | 598 | { |
a37076f1 BA |
599 | const V = VariantRules; |
600 | return this.isAttackedBySlideNJump(sq, colors, V.KING, | |
601 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep"); | |
1d184b4c BA |
602 | } |
603 | ||
604 | // Generic method for non-pawn pieces ("sliding or jumping"): is x,y attacked by piece != color ? | |
46302e64 | 605 | isAttackedBySlideNJump([x,y], colors, piece, steps, oneStep) |
1d184b4c BA |
606 | { |
607 | for (let step of steps) | |
608 | { | |
609 | let rx = x+step[0], ry = y+step[1]; | |
610 | while (rx>=0 && rx<8 && ry>=0 && ry<8 && this.board[rx][ry] == VariantRules.EMPTY | |
611 | && !oneStep) | |
612 | { | |
613 | rx += step[0]; | |
614 | ry += step[1]; | |
615 | } | |
616 | if (rx>=0 && rx<8 && ry>=0 && ry<8 && this.board[rx][ry] != VariantRules.EMPTY | |
46302e64 | 617 | && this.getPiece(rx,ry) == piece && colors.includes(this.getColor(rx,ry))) |
1d184b4c BA |
618 | { |
619 | return true; | |
620 | } | |
621 | } | |
622 | return false; | |
623 | } | |
624 | ||
4b5fe306 | 625 | // Is color c under check after move ? |
46302e64 | 626 | underCheck(move) |
1d184b4c | 627 | { |
46302e64 | 628 | const color = this.turn; |
1d184b4c | 629 | this.play(move); |
46302e64 | 630 | let res = this.isAttacked(this.kingPos[color], this.getOppCol(color)); |
1d184b4c BA |
631 | this.undo(move); |
632 | return res; | |
633 | } | |
634 | ||
4b5fe306 | 635 | // On which squares is color c under check (after move) ? |
46302e64 | 636 | getCheckSquares(move) |
4b5fe306 BA |
637 | { |
638 | this.play(move); | |
204e289b | 639 | const color = this.turn; //opponent |
46302e64 BA |
640 | let res = this.isAttacked(this.kingPos[color], this.getOppCol(color)) |
641 | ? [ JSON.parse(JSON.stringify(this.kingPos[color])) ] //need to duplicate! | |
4b5fe306 BA |
642 | : [ ]; |
643 | this.undo(move); | |
644 | return res; | |
645 | } | |
646 | ||
1d184b4c BA |
647 | // Apply a move on board |
648 | static PlayOnBoard(board, move) | |
649 | { | |
650 | for (let psq of move.vanish) | |
651 | board[psq.x][psq.y] = VariantRules.EMPTY; | |
652 | for (let psq of move.appear) | |
653 | board[psq.x][psq.y] = psq.c + psq.p; | |
654 | } | |
655 | // Un-apply the played move | |
656 | static UndoOnBoard(board, move) | |
657 | { | |
658 | for (let psq of move.appear) | |
659 | board[psq.x][psq.y] = VariantRules.EMPTY; | |
660 | for (let psq of move.vanish) | |
661 | board[psq.x][psq.y] = psq.c + psq.p; | |
662 | } | |
663 | ||
d3334c3a | 664 | // Before move is played, update variables + flags |
1d184b4c BA |
665 | updateVariables(move) |
666 | { | |
667 | const piece = this.getPiece(move.start.x,move.start.y); | |
668 | const c = this.getColor(move.start.x,move.start.y); | |
669 | const firstRank = (c == "w" ? 7 : 0); | |
670 | ||
671 | // Update king position + flags | |
672 | if (piece == VariantRules.KING && move.appear.length > 0) | |
673 | { | |
674 | this.kingPos[c][0] = move.appear[0].x; | |
675 | this.kingPos[c][1] = move.appear[0].y; | |
2526c041 | 676 | this.castleFlags[c] = [false,false]; |
1d184b4c BA |
677 | return; |
678 | } | |
679 | const oppCol = this.getOppCol(c); | |
680 | const oppFirstRank = 7 - firstRank; | |
681 | if (move.start.x == firstRank //our rook moves? | |
682 | && this.INIT_COL_ROOK[c].includes(move.start.y)) | |
683 | { | |
2526c041 BA |
684 | const flagIdx = (move.start.y == this.INIT_COL_ROOK[c][0] ? 0 : 1); |
685 | this.castleFlags[c][flagIdx] = false; | |
1d184b4c BA |
686 | } |
687 | else if (move.end.x == oppFirstRank //we took opponent rook? | |
aea1443e | 688 | && this.INIT_COL_ROOK[oppCol].includes(move.end.y)) |
1d184b4c | 689 | { |
2526c041 BA |
690 | const flagIdx = (move.end.y == this.INIT_COL_ROOK[oppCol][0] ? 0 : 1); |
691 | this.castleFlags[oppCol][flagIdx] = false; | |
1d184b4c BA |
692 | } |
693 | } | |
694 | ||
d3334c3a | 695 | unupdateVariables(move) |
1d184b4c | 696 | { |
d3334c3a BA |
697 | // (Potentially) Reset king position |
698 | const c = this.getColor(move.start.x,move.start.y); | |
699 | if (this.getPiece(move.start.x,move.start.y) == VariantRules.KING) | |
700 | this.kingPos[c] = [move.start.x, move.start.y]; | |
701 | } | |
1d184b4c | 702 | |
d3334c3a BA |
703 | play(move, ingame) |
704 | { | |
a0f5dbaa BA |
705 | // DEBUG: |
706 | // if (!this.states) this.states = []; | |
707 | // if (!ingame) this.states.push(JSON.stringify(this.board)); | |
708 | ||
dfb4afc1 | 709 | if (!!ingame) |
dfb4afc1 | 710 | move.notation = this.getNotation(move); |
dfb4afc1 | 711 | |
2526c041 | 712 | move.flags = JSON.stringify(this.flags); //save flags (for undo) |
d3334c3a BA |
713 | this.updateVariables(move); |
714 | this.moves.push(move); | |
1d184b4c BA |
715 | this.epSquares.push( this.getEpSquare(move) ); |
716 | VariantRules.PlayOnBoard(this.board, move); | |
1d184b4c BA |
717 | } |
718 | ||
cd4cad04 | 719 | undo(move) |
1d184b4c BA |
720 | { |
721 | VariantRules.UndoOnBoard(this.board, move); | |
722 | this.epSquares.pop(); | |
d3334c3a BA |
723 | this.moves.pop(); |
724 | this.unupdateVariables(move); | |
2526c041 | 725 | this.parseFlags(JSON.parse(move.flags)); |
a0f5dbaa BA |
726 | |
727 | // DEBUG: | |
728 | // let state = this.states.pop(); | |
729 | // if (JSON.stringify(this.board) != state) | |
730 | // debugger; | |
1d184b4c BA |
731 | } |
732 | ||
733 | ////////////// | |
734 | // END OF GAME | |
735 | ||
1af36beb | 736 | checkRepetition() |
1d184b4c BA |
737 | { |
738 | // Check for 3 repetitions | |
739 | if (this.moves.length >= 8) | |
740 | { | |
741 | // NOTE: crude detection, only moves repetition | |
742 | const L = this.moves.length; | |
743 | if (_.isEqual(this.moves[L-1], this.moves[L-5]) && | |
744 | _.isEqual(this.moves[L-2], this.moves[L-6]) && | |
745 | _.isEqual(this.moves[L-3], this.moves[L-7]) && | |
746 | _.isEqual(this.moves[L-4], this.moves[L-8])) | |
747 | { | |
1af36beb | 748 | return true; |
1d184b4c BA |
749 | } |
750 | } | |
1af36beb BA |
751 | return false; |
752 | } | |
1d184b4c | 753 | |
1af36beb BA |
754 | checkGameOver() |
755 | { | |
756 | if (this.checkRepetition()) | |
757 | return "1/2"; | |
758 | ||
759 | if (this.atLeastOneMove()) // game not over | |
1d184b4c | 760 | return "*"; |
1d184b4c BA |
761 | |
762 | // Game over | |
46302e64 | 763 | return this.checkGameEnd(); |
1d184b4c BA |
764 | } |
765 | ||
46302e64 BA |
766 | // No moves are possible: compute score |
767 | checkGameEnd() | |
1d184b4c | 768 | { |
46302e64 | 769 | const color = this.turn; |
1d184b4c BA |
770 | // No valid move: stalemate or checkmate? |
771 | if (!this.isAttacked(this.kingPos[color], this.getOppCol(color))) | |
772 | return "1/2"; | |
773 | // OK, checkmate | |
774 | return color == "w" ? "0-1" : "1-0"; | |
775 | } | |
776 | ||
777 | //////// | |
778 | //ENGINE | |
779 | ||
780 | // Pieces values | |
781 | static get VALUES() { | |
782 | return { | |
783 | 'p': 1, | |
784 | 'r': 5, | |
785 | 'n': 3, | |
786 | 'b': 3, | |
787 | 'q': 9, | |
788 | 'k': 1000 | |
789 | }; | |
790 | } | |
791 | ||
9e42b4dd BA |
792 | static get INFINITY() { |
793 | return 9999; //"checkmate" (unreachable eval) | |
794 | } | |
795 | ||
796 | static get THRESHOLD_MATE() { | |
797 | // At this value or above, the game is over | |
798 | return VariantRules.INFINITY; | |
799 | } | |
800 | ||
1d184b4c | 801 | // Assumption: at least one legal move |
9e42b4dd | 802 | getComputerMove(moves1) //moves1 might be precomputed (Magnetic chess) |
1d184b4c | 803 | { |
9e42b4dd | 804 | const maxeval = VariantRules.INFINITY; |
46302e64 | 805 | const color = this.turn; |
9e42b4dd BA |
806 | if (!moves1) |
807 | moves1 = this.getAllValidMoves(); | |
1d184b4c | 808 | |
06ddfe34 | 809 | // Rank moves using a min-max at depth 2 |
1d184b4c BA |
810 | for (let i=0; i<moves1.length; i++) |
811 | { | |
9e42b4dd BA |
812 | moves1[i].eval = (color=="w" ? -1 : 1) * maxeval; //very low, I'm checkmated |
813 | let eval2 = (color=="w" ? 1 : -1) * maxeval; //initialized with checkmate value | |
1d184b4c BA |
814 | this.play(moves1[i]); |
815 | // Second half-move: | |
46302e64 | 816 | let moves2 = this.getAllValidMoves(); |
1d184b4c BA |
817 | // If no possible moves AND underCheck, eval2 is correct. |
818 | // If !underCheck, eval2 is 0 (stalemate). | |
46302e64 | 819 | if (moves2.length == 0 && this.checkGameEnd() == "1/2") |
1d184b4c BA |
820 | eval2 = 0; |
821 | for (let j=0; j<moves2.length; j++) | |
822 | { | |
823 | this.play(moves2[j]); | |
824 | let evalPos = this.evalPosition(); | |
825 | if ((color == "w" && evalPos < eval2) || (color=="b" && evalPos > eval2)) | |
826 | eval2 = evalPos; | |
827 | this.undo(moves2[j]); | |
828 | } | |
829 | if ((color=="w" && eval2 > moves1[i].eval) || (color=="b" && eval2 < moves1[i].eval)) | |
830 | moves1[i].eval = eval2; | |
831 | this.undo(moves1[i]); | |
832 | } | |
833 | moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); }); | |
834 | ||
9e42b4dd BA |
835 | // Skip depth 3 if we found a checkmate (or if we are checkmated in 1...) |
836 | if (Math.abs(moves1[0].eval) < VariantRules.THRESHOLD_MATE) | |
e64a4eff | 837 | { |
9e42b4dd BA |
838 | // TODO: show current analyzed move for depth 3, allow stopping eval (return moves1[0]) |
839 | for (let i=0; i<moves1.length; i++) | |
840 | { | |
841 | this.play(moves1[i]); | |
842 | // 0.1 * oldEval : heuristic to avoid some bad moves (not all...) | |
843 | moves1[i].eval = 0.1*moves1[i].eval + this.alphabeta(2, -maxeval, maxeval); | |
844 | this.undo(moves1[i]); | |
845 | } | |
846 | moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); }); | |
e64a4eff | 847 | } |
1d184b4c BA |
848 | |
849 | let candidates = [0]; //indices of candidates moves | |
850 | for (let j=1; j<moves1.length && moves1[j].eval == moves1[0].eval; j++) | |
851 | candidates.push(j); | |
9de73b71 | 852 | // console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; })); |
1d184b4c BA |
853 | return moves1[_.sample(candidates, 1)]; |
854 | } | |
855 | ||
46302e64 | 856 | alphabeta(depth, alpha, beta) |
1d184b4c | 857 | { |
9e42b4dd | 858 | const maxeval = VariantRules.INFINITY; |
46302e64 BA |
859 | const color = this.turn; |
860 | if (!this.atLeastOneMove()) | |
1d184b4c | 861 | { |
46302e64 | 862 | switch (this.checkGameEnd()) |
1d184b4c BA |
863 | { |
864 | case "1/2": return 0; | |
9e42b4dd | 865 | default: return color=="w" ? -maxeval : maxeval; |
1d184b4c BA |
866 | } |
867 | } | |
868 | if (depth == 0) | |
869 | return this.evalPosition(); | |
46302e64 | 870 | const moves = this.getAllValidMoves(); |
9e42b4dd | 871 | let v = color=="w" ? -maxeval : maxeval; |
1d184b4c BA |
872 | if (color == "w") |
873 | { | |
874 | for (let i=0; i<moves.length; i++) | |
875 | { | |
876 | this.play(moves[i]); | |
46302e64 | 877 | v = Math.max(v, this.alphabeta(depth-1, alpha, beta)); |
1d184b4c BA |
878 | this.undo(moves[i]); |
879 | alpha = Math.max(alpha, v); | |
880 | if (alpha >= beta) | |
881 | break; //beta cutoff | |
882 | } | |
883 | } | |
884 | else //color=="b" | |
885 | { | |
886 | for (let i=0; i<moves.length; i++) | |
887 | { | |
888 | this.play(moves[i]); | |
46302e64 | 889 | v = Math.min(v, this.alphabeta(depth-1, alpha, beta)); |
1d184b4c BA |
890 | this.undo(moves[i]); |
891 | beta = Math.min(beta, v); | |
892 | if (alpha >= beta) | |
893 | break; //alpha cutoff | |
894 | } | |
895 | } | |
896 | return v; | |
897 | } | |
898 | ||
899 | evalPosition() | |
900 | { | |
901 | const [sizeX,sizeY] = VariantRules.size; | |
902 | let evaluation = 0; | |
903 | //Just count material for now | |
904 | for (let i=0; i<sizeX; i++) | |
905 | { | |
906 | for (let j=0; j<sizeY; j++) | |
907 | { | |
908 | if (this.board[i][j] != VariantRules.EMPTY) | |
909 | { | |
910 | const sign = this.getColor(i,j) == "w" ? 1 : -1; | |
911 | evaluation += sign * VariantRules.VALUES[this.getPiece(i,j)]; | |
912 | } | |
913 | } | |
914 | } | |
915 | return evaluation; | |
916 | } | |
917 | ||
918 | //////////// | |
919 | // FEN utils | |
920 | ||
921 | // Overridable.. | |
922 | static GenRandInitFen() | |
923 | { | |
924 | let pieces = [new Array(8), new Array(8)]; | |
925 | // Shuffle pieces on first and last rank | |
926 | for (let c = 0; c <= 1; c++) | |
927 | { | |
928 | let positions = _.range(8); | |
929 | ||
930 | // Get random squares for bishops | |
931 | let randIndex = 2 * _.random(3); | |
932 | let bishop1Pos = positions[randIndex]; | |
933 | // The second bishop must be on a square of different color | |
934 | let randIndex_tmp = 2 * _.random(3) + 1; | |
935 | let bishop2Pos = positions[randIndex_tmp]; | |
936 | // Remove chosen squares | |
937 | positions.splice(Math.max(randIndex,randIndex_tmp), 1); | |
938 | positions.splice(Math.min(randIndex,randIndex_tmp), 1); | |
939 | ||
940 | // Get random squares for knights | |
941 | randIndex = _.random(5); | |
942 | let knight1Pos = positions[randIndex]; | |
943 | positions.splice(randIndex, 1); | |
944 | randIndex = _.random(4); | |
945 | let knight2Pos = positions[randIndex]; | |
946 | positions.splice(randIndex, 1); | |
947 | ||
948 | // Get random square for queen | |
949 | randIndex = _.random(3); | |
950 | let queenPos = positions[randIndex]; | |
951 | positions.splice(randIndex, 1); | |
952 | ||
953 | // Rooks and king positions are now fixed, because of the ordering rook-king-rook | |
954 | let rook1Pos = positions[0]; | |
955 | let kingPos = positions[1]; | |
956 | let rook2Pos = positions[2]; | |
957 | ||
958 | // Finally put the shuffled pieces in the board array | |
959 | pieces[c][rook1Pos] = 'r'; | |
960 | pieces[c][knight1Pos] = 'n'; | |
961 | pieces[c][bishop1Pos] = 'b'; | |
962 | pieces[c][queenPos] = 'q'; | |
963 | pieces[c][kingPos] = 'k'; | |
964 | pieces[c][bishop2Pos] = 'b'; | |
965 | pieces[c][knight2Pos] = 'n'; | |
966 | pieces[c][rook2Pos] = 'r'; | |
967 | } | |
968 | let fen = pieces[0].join("") + | |
969 | "/pppppppp/8/8/8/8/PPPPPPPP/" + | |
970 | pieces[1].join("").toUpperCase() + | |
f3802fcd | 971 | " 1111"; //add flags |
1d184b4c BA |
972 | return fen; |
973 | } | |
974 | ||
975 | // Return current fen according to pieces+colors state | |
976 | getFen() | |
977 | { | |
f3802fcd | 978 | return this.getBaseFen() + " " + this.getFlagsFen(); |
1d184b4c BA |
979 | } |
980 | ||
981 | getBaseFen() | |
982 | { | |
983 | let fen = ""; | |
984 | let [sizeX,sizeY] = VariantRules.size; | |
985 | for (let i=0; i<sizeX; i++) | |
986 | { | |
987 | let emptyCount = 0; | |
988 | for (let j=0; j<sizeY; j++) | |
989 | { | |
990 | if (this.board[i][j] == VariantRules.EMPTY) | |
991 | emptyCount++; | |
992 | else | |
993 | { | |
994 | if (emptyCount > 0) | |
995 | { | |
996 | // Add empty squares in-between | |
997 | fen += emptyCount; | |
998 | emptyCount = 0; | |
999 | } | |
1000 | fen += VariantRules.board2fen(this.board[i][j]); | |
1001 | } | |
1002 | } | |
1003 | if (emptyCount > 0) | |
1004 | { | |
1005 | // "Flush remainder" | |
1006 | fen += emptyCount; | |
1007 | } | |
1008 | if (i < sizeX - 1) | |
1009 | fen += "/"; //separate rows | |
1010 | } | |
1011 | return fen; | |
1012 | } | |
1013 | ||
1014 | // Overridable.. | |
1015 | getFlagsFen() | |
1016 | { | |
1017 | let fen = ""; | |
1018 | // Add castling flags | |
1019 | for (let i of ['w','b']) | |
1020 | { | |
1021 | for (let j=0; j<2; j++) | |
2526c041 | 1022 | fen += this.castleFlags[i][j] ? '1' : '0'; |
1d184b4c BA |
1023 | } |
1024 | return fen; | |
1025 | } | |
1026 | ||
1027 | // Context: just before move is played, turn hasn't changed | |
1028 | getNotation(move) | |
1029 | { | |
aea1443e | 1030 | if (move.appear.length == 2 && move.appear[0].p == VariantRules.KING) |
1d184b4c BA |
1031 | { |
1032 | // Castle | |
1033 | if (move.end.y < move.start.y) | |
1034 | return "0-0-0"; | |
1035 | else | |
1036 | return "0-0"; | |
1037 | } | |
1038 | ||
1039 | // Translate final square | |
270968d6 | 1040 | const finalSquare = |
1d184b4c BA |
1041 | String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x); |
1042 | ||
270968d6 | 1043 | const piece = this.getPiece(move.start.x, move.start.y); |
1d184b4c BA |
1044 | if (piece == VariantRules.PAWN) |
1045 | { | |
1046 | // Pawn move | |
1047 | let notation = ""; | |
5bfb0956 | 1048 | if (move.vanish.length > move.appear.length) |
1d184b4c BA |
1049 | { |
1050 | // Capture | |
270968d6 | 1051 | const startColumn = String.fromCharCode(97 + move.start.y); |
1d184b4c BA |
1052 | notation = startColumn + "x" + finalSquare; |
1053 | } | |
1054 | else //no capture | |
1055 | notation = finalSquare; | |
1056 | if (move.appear.length > 0 && piece != move.appear[0].p) //promotion | |
1057 | notation += "=" + move.appear[0].p.toUpperCase(); | |
1058 | return notation; | |
1059 | } | |
1060 | ||
1061 | else | |
1062 | { | |
1063 | // Piece movement | |
f3c10e18 BA |
1064 | return piece.toUpperCase() + |
1065 | (move.vanish.length > move.appear.length ? "x" : "") + finalSquare; | |
1d184b4c BA |
1066 | } |
1067 | } | |
dfb4afc1 BA |
1068 | |
1069 | // The score is already computed when calling this function | |
01a135e2 | 1070 | getPGN(mycolor, score, fenStart, mode) |
dfb4afc1 BA |
1071 | { |
1072 | let pgn = ""; | |
1073 | pgn += '[Site "vchess.club"]<br>'; | |
1074 | const d = new Date(); | |
5e622704 | 1075 | const opponent = mode=="human" ? "Anonymous" : "Computer"; |
0f51ef98 | 1076 | pgn += '[Variant "' + variant + '"]<br>'; |
f61349e6 | 1077 | pgn += '[Date "' + d.getFullYear() + '-' + (d.getMonth()+1) + '-' + d.getDate() + '"]<br>'; |
01a135e2 BA |
1078 | pgn += '[White "' + (mycolor=='w'?'Myself':opponent) + '"]<br>'; |
1079 | pgn += '[Black "' + (mycolor=='b'?'Myself':opponent) + '"]<br>'; | |
762b7c9c BA |
1080 | pgn += '[Fen "' + fenStart + '"]<br>'; |
1081 | pgn += '[Result "' + score + '"]<br><br>'; | |
dfb4afc1 BA |
1082 | |
1083 | for (let i=0; i<this.moves.length; i++) | |
1084 | { | |
1085 | if (i % 2 == 0) | |
1086 | pgn += ((i/2)+1) + "."; | |
1087 | pgn += this.moves[i].notation + " "; | |
1088 | } | |
1089 | ||
1090 | pgn += score; | |
1091 | return pgn; | |
1092 | } | |
1d184b4c | 1093 | } |