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1 | import { ChessRules } from "@/base_rules"; |
2 | ||
3 | export const VariantRules = class CheckeredRules extends ChessRules | |
1d184b4c | 4 | { |
dac39588 BA |
5 | static getPpath(b) |
6 | { | |
7 | return b[0]=='c' ? "Checkered/"+b : b; | |
8 | } | |
9 | ||
10 | static board2fen(b) | |
11 | { | |
12 | const checkered_codes = { | |
13 | 'p': 's', | |
14 | 'q': 't', | |
15 | 'r': 'u', | |
16 | 'b': 'c', | |
17 | 'n': 'o', | |
18 | }; | |
19 | if (b[0]=="c") | |
20 | return checkered_codes[b[1]]; | |
21 | return ChessRules.board2fen(b); | |
22 | } | |
23 | ||
24 | static fen2board(f) | |
25 | { | |
26 | // Tolerate upper-case versions of checkered pieces (why not?) | |
27 | const checkered_pieces = { | |
28 | 's': 'p', | |
29 | 'S': 'p', | |
30 | 't': 'q', | |
31 | 'T': 'q', | |
32 | 'u': 'r', | |
33 | 'U': 'r', | |
34 | 'c': 'b', | |
35 | 'C': 'b', | |
36 | 'o': 'n', | |
37 | 'O': 'n', | |
38 | }; | |
39 | if (Object.keys(checkered_pieces).includes(f)) | |
40 | return 'c'+checkered_pieces[f]; | |
41 | return ChessRules.fen2board(f); | |
42 | } | |
43 | ||
44 | static get PIECES() | |
45 | { | |
46 | return ChessRules.PIECES.concat(['s','t','u','c','o']); | |
47 | } | |
7931e479 | 48 | |
03cff0f7 BA |
49 | setOtherVariables(fen) |
50 | { | |
51 | super.setOtherVariables(fen); | |
52 | // Local stack of non-capturing checkered moves: | |
53 | this.cmoves = []; | |
54 | const cmove = fen.split(" ")[5]; | |
55 | if (cmove == "-") | |
56 | this.cmoves.push(null); | |
57 | else | |
58 | { | |
59 | this.cmoves.push({ | |
60 | start: ChessRules.SquareToCoords(cmove.substr(0,2)), | |
61 | end: ChessRules.SquareToCoords(cmove.substr(2)), | |
62 | }); | |
63 | } | |
64 | } | |
65 | ||
66 | static IsGoodFen(fen) | |
67 | { | |
dac39588 | 68 | if (!ChessRules.IsGoodFen(fen)) |
03cff0f7 BA |
69 | return false; |
70 | const fenParts = fen.split(" "); | |
71 | if (fenParts.length != 6) | |
72 | return false; | |
73 | if (fenParts[5] != "-" && !fenParts[5].match(/^([a-h][1-8]){2}$/)) | |
74 | return false; | |
75 | return true; | |
76 | } | |
77 | ||
dac39588 BA |
78 | static IsGoodFlags(flags) |
79 | { | |
80 | // 4 for castle + 16 for pawns | |
81 | return !!flags.match(/^[01]{20,20}$/); | |
82 | } | |
83 | ||
84 | setFlags(fenflags) | |
85 | { | |
86 | super.setFlags(fenflags); //castleFlags | |
87 | this.pawnFlags = | |
88 | { | |
89 | "w": [...Array(8).fill(true)], //pawns can move 2 squares? | |
90 | "b": [...Array(8).fill(true)], | |
91 | }; | |
92 | if (!fenflags) | |
93 | return; | |
94 | const flags = fenflags.substr(4); //skip first 4 digits, for castle | |
95 | for (let c of ['w','b']) | |
96 | { | |
97 | for (let i=0; i<8; i++) | |
98 | this.pawnFlags[c][i] = (flags.charAt((c=='w'?0:8)+i) == '1'); | |
99 | } | |
100 | } | |
101 | ||
102 | aggregateFlags() | |
103 | { | |
104 | return [this.castleFlags, this.pawnFlags]; | |
105 | } | |
106 | ||
107 | disaggregateFlags(flags) | |
108 | { | |
109 | this.castleFlags = flags[0]; | |
110 | this.pawnFlags = flags[1]; | |
111 | } | |
1d184b4c | 112 | |
03cff0f7 BA |
113 | getCmove(move) |
114 | { | |
115 | if (move.appear[0].c == 'c' && move.vanish.length == 1) | |
116 | return {start: move.start, end: move.end}; | |
117 | return null; | |
118 | } | |
119 | ||
dac39588 BA |
120 | canTake([x1,y1], [x2,y2]) |
121 | { | |
122 | const color1 = this.getColor(x1,y1); | |
123 | const color2 = this.getColor(x2,y2); | |
124 | // Checkered aren't captured | |
125 | return color1 != color2 && color2 != 'c' && (color1 != 'c' || color2 != this.turn); | |
126 | } | |
127 | ||
128 | // Post-processing: apply "checkerization" of standard moves | |
129 | getPotentialMovesFrom([x,y]) | |
130 | { | |
131 | let standardMoves = super.getPotentialMovesFrom([x,y]); | |
132 | const lastRank = this.turn == "w" ? 0 : 7; | |
133 | if (this.getPiece(x,y) == V.KING) | |
134 | return standardMoves; //king has to be treated differently (for castles) | |
135 | let moves = []; | |
136 | standardMoves.forEach(m => { | |
137 | if (m.vanish[0].p == V.PAWN) | |
138 | { | |
139 | if (Math.abs(m.end.x-m.start.x)==2 && !this.pawnFlags[this.turn][m.start.y]) | |
140 | return; //skip forbidden 2-squares jumps | |
141 | if (this.board[m.end.x][m.end.y] == V.EMPTY && m.vanish.length==2 | |
142 | && this.getColor(m.start.x,m.start.y) == 'c') | |
143 | { | |
144 | return; //checkered pawns cannot take en-passant | |
145 | } | |
146 | } | |
147 | if (m.vanish.length == 1) | |
148 | moves.push(m); //no capture | |
149 | else | |
150 | { | |
151 | // A capture occured (m.vanish.length == 2) | |
152 | m.appear[0].c = "c"; | |
153 | moves.push(m); | |
154 | if (m.appear[0].p != m.vanish[1].p //avoid promotions (already treated): | |
155 | && (m.vanish[0].p != V.PAWN || m.end.x != lastRank)) | |
156 | { | |
157 | // Add transformation into captured piece | |
158 | let m2 = JSON.parse(JSON.stringify(m)); | |
159 | m2.appear[0].p = m.vanish[1].p; | |
160 | moves.push(m2); | |
161 | } | |
162 | } | |
163 | }); | |
164 | return moves; | |
165 | } | |
166 | ||
167 | canIplay(side, [x,y]) | |
168 | { | |
169 | return (side == this.turn && [side,'c'].includes(this.getColor(x,y))); | |
170 | } | |
171 | ||
172 | // Does m2 un-do m1 ? (to disallow undoing checkered moves) | |
173 | oppositeMoves(m1, m2) | |
174 | { | |
175 | return (!!m1 && m2.appear[0].c == 'c' | |
03cff0f7 | 176 | && m2.appear.length == 1 && m2.vanish.length == 1 |
dac39588 BA |
177 | && m1.start.x == m2.end.x && m1.end.x == m2.start.x |
178 | && m1.start.y == m2.end.y && m1.end.y == m2.start.y); | |
179 | } | |
180 | ||
181 | filterValid(moves) | |
182 | { | |
183 | if (moves.length == 0) | |
184 | return []; | |
185 | const color = this.turn; | |
186 | return moves.filter(m => { | |
187 | const L = this.cmoves.length; //at least 1: init from FEN | |
188 | if (this.oppositeMoves(this.cmoves[L-1], m)) | |
189 | return false; | |
190 | this.play(m); | |
191 | const res = !this.underCheck(color); | |
192 | this.undo(m); | |
193 | return res; | |
194 | }); | |
195 | } | |
196 | ||
197 | isAttackedByPawn([x,y], colors) | |
198 | { | |
199 | for (let c of colors) | |
200 | { | |
201 | const color = (c=="c" ? this.turn : c); | |
202 | let pawnShift = (color=="w" ? 1 : -1); | |
203 | if (x+pawnShift>=0 && x+pawnShift<8) | |
204 | { | |
205 | for (let i of [-1,1]) | |
206 | { | |
207 | if (y+i>=0 && y+i<8 && this.getPiece(x+pawnShift,y+i)==V.PAWN | |
208 | && this.getColor(x+pawnShift,y+i)==c) | |
209 | { | |
210 | return true; | |
211 | } | |
212 | } | |
213 | } | |
214 | } | |
215 | return false; | |
216 | } | |
217 | ||
218 | underCheck(color) | |
219 | { | |
220 | return this.isAttacked(this.kingPos[color], [V.GetOppCol(color),'c']); | |
221 | } | |
222 | ||
223 | getCheckSquares(color) | |
224 | { | |
225 | // Artifically change turn, for checkered pawns | |
226 | this.turn = V.GetOppCol(color); | |
227 | const kingAttacked = this.isAttacked( | |
228 | this.kingPos[color], [V.GetOppCol(color),'c']); | |
229 | let res = kingAttacked | |
230 | ? [JSON.parse(JSON.stringify(this.kingPos[color]))] //need to duplicate! | |
231 | : []; | |
232 | this.turn = color; | |
233 | return res; | |
234 | } | |
235 | ||
236 | updateVariables(move) | |
237 | { | |
238 | super.updateVariables(move); | |
239 | // Does this move turn off a 2-squares pawn flag? | |
240 | const secondRank = [1,6]; | |
241 | if (secondRank.includes(move.start.x) && move.vanish[0].p == V.PAWN) | |
242 | this.pawnFlags[move.start.x==6 ? "w" : "b"][move.start.y] = false; | |
243 | } | |
244 | ||
245 | getCurrentScore() | |
246 | { | |
0c3fe8a6 BA |
247 | if (this.atLeastOneMove()) // game not over |
248 | return "*"; | |
249 | ||
250 | const color = this.turn; | |
dac39588 BA |
251 | // Artifically change turn, for checkered pawns |
252 | this.turn = V.GetOppCol(this.turn); | |
253 | const res = this.isAttacked(this.kingPos[color], [V.GetOppCol(color),'c']) | |
254 | ? (color == "w" ? "0-1" : "1-0") | |
255 | : "1/2"; | |
256 | this.turn = V.GetOppCol(this.turn); | |
257 | return res; | |
258 | } | |
259 | ||
260 | evalPosition() | |
261 | { | |
262 | let evaluation = 0; | |
263 | //Just count material for now, considering checkered neutral (...) | |
264 | for (let i=0; i<V.size.x; i++) | |
265 | { | |
266 | for (let j=0; j<V.size.y; j++) | |
267 | { | |
268 | if (this.board[i][j] != V.EMPTY) | |
269 | { | |
270 | const sqColor = this.getColor(i,j); | |
271 | const sign = sqColor == "w" ? 1 : (sqColor=="b" ? -1 : 0); | |
272 | evaluation += sign * V.VALUES[this.getPiece(i,j)]; | |
273 | } | |
274 | } | |
275 | } | |
276 | return evaluation; | |
277 | } | |
278 | ||
279 | static GenRandInitFen() | |
280 | { | |
281 | const randFen = ChessRules.GenRandInitFen(); | |
282 | // Add 16 pawns flags + empty cmove: | |
283 | return randFen.replace(" w 0 1111", " w 0 11111111111111111111 -"); | |
284 | } | |
1d184b4c | 285 | |
03cff0f7 BA |
286 | static ParseFen(fen) |
287 | { | |
288 | const fenParsed = ChessRules.ParseFen(fen); | |
289 | return Object.assign({}, | |
290 | ChessRules.ParseFen(fen), | |
291 | {cmove: fen.split(" ")[5]}); | |
292 | } | |
293 | ||
294 | getFen() | |
295 | { | |
296 | const L = this.cmoves.length; | |
297 | const cmoveFen = (!this.cmoves[L-1] | |
298 | ? "-" | |
299 | : ChessRules.CoordsToSquare(this.cmoves[L-1].start) | |
300 | + ChessRules.CoordsToSquare(this.cmoves[L-1].end)); | |
301 | return super.getFen() + " " + cmoveFen; | |
302 | } | |
303 | ||
dac39588 BA |
304 | getFlagsFen() |
305 | { | |
306 | let fen = super.getFlagsFen(); | |
307 | // Add pawns flags | |
308 | for (let c of ['w','b']) | |
309 | { | |
310 | for (let i=0; i<8; i++) | |
311 | fen += this.pawnFlags[c][i] ? '1' : '0'; | |
312 | } | |
313 | return fen; | |
314 | } | |
1d184b4c | 315 | |
03cff0f7 BA |
316 | // TODO (design): this cmove update here or in (un)updateVariables ? |
317 | play(move) | |
318 | { | |
319 | this.cmoves.push( this.getCmove(move) ); | |
320 | super.play(move); | |
321 | } | |
322 | ||
323 | undo(move) | |
324 | { | |
325 | this.cmoves.pop(); | |
326 | super.undo(move); | |
327 | } | |
328 | ||
dac39588 BA |
329 | getNotation(move) |
330 | { | |
331 | if (move.appear.length == 2) | |
332 | { | |
333 | // Castle | |
334 | if (move.end.y < move.start.y) | |
335 | return "0-0-0"; | |
336 | else | |
337 | return "0-0"; | |
338 | } | |
339 | ||
340 | // Translate final square | |
341 | const finalSquare = V.CoordsToSquare(move.end); | |
342 | ||
343 | const piece = this.getPiece(move.start.x, move.start.y); | |
344 | if (piece == V.PAWN) | |
345 | { | |
346 | // Pawn move | |
347 | let notation = ""; | |
348 | if (move.vanish.length > 1) | |
349 | { | |
350 | // Capture | |
351 | const startColumn = V.CoordToColumn(move.start.y); | |
352 | notation = startColumn + "x" + finalSquare + | |
353 | "=" + move.appear[0].p.toUpperCase(); | |
354 | } | |
355 | else //no capture | |
356 | { | |
357 | notation = finalSquare; | |
358 | if (move.appear.length > 0 && piece != move.appear[0].p) //promotion | |
359 | notation += "=" + move.appear[0].p.toUpperCase(); | |
360 | } | |
361 | return notation; | |
362 | } | |
363 | ||
364 | else | |
365 | { | |
366 | // Piece movement | |
367 | return piece.toUpperCase() + (move.vanish.length > 1 ? "x" : "") + finalSquare | |
368 | + (move.vanish.length > 1 ? "=" + move.appear[0].p.toUpperCase() : ""); | |
369 | } | |
370 | } | |
1d184b4c | 371 | } |