| 1 | class UltimaRules extends ChessRules |
| 2 | { |
| 3 | static getPpath(b) |
| 4 | { |
| 5 | if (b[1] == "m") //'m' for Immobilizer (I is too similar to 1) |
| 6 | return "Ultima/" + b; |
| 7 | return b; //usual piece |
| 8 | } |
| 9 | |
| 10 | initVariables(fen) |
| 11 | { |
| 12 | this.kingPos = {'w':[-1,-1], 'b':[-1,-1]}; |
| 13 | const fenParts = fen.split(" "); |
| 14 | const position = fenParts[0].split("/"); |
| 15 | for (let i=0; i<position.length; i++) |
| 16 | { |
| 17 | let k = 0; |
| 18 | for (let j=0; j<position[i].length; j++) |
| 19 | { |
| 20 | switch (position[i].charAt(j)) |
| 21 | { |
| 22 | case 'k': |
| 23 | this.kingPos['b'] = [i,k]; |
| 24 | break; |
| 25 | case 'K': |
| 26 | this.kingPos['w'] = [i,k]; |
| 27 | break; |
| 28 | default: |
| 29 | let num = parseInt(position[i].charAt(j)); |
| 30 | if (!isNaN(num)) |
| 31 | k += (num-1); |
| 32 | } |
| 33 | k++; |
| 34 | } |
| 35 | } |
| 36 | this.epSquares = []; //no en-passant here |
| 37 | } |
| 38 | |
| 39 | setFlags(fen) |
| 40 | { |
| 41 | // TODO: for compatibility? |
| 42 | this.castleFlags = {"w":[false,false], "b":[false,false]}; |
| 43 | } |
| 44 | |
| 45 | static get IMMOBILIZER() { return 'm'; } |
| 46 | // Although other pieces keep their names here for coding simplicity, |
| 47 | // keep in mind that: |
| 48 | // - a "rook" is a coordinator, capturing by coordinating with the king |
| 49 | // - a "knight" is a long-leaper, capturing as in draughts |
| 50 | // - a "bishop" is a chameleon, capturing as its prey |
| 51 | // - a "queen" is a withdrawer, capturing by moving away from pieces |
| 52 | |
| 53 | getPotentialMovesFrom([x,y]) |
| 54 | { |
| 55 | // Pre-check: is thing on this square immobilized? |
| 56 | // In this case add potential suicide as a move "taking the immobilizer" |
| 57 | const piece = this.getPiece(x,y); |
| 58 | const color = this.getColor(x,y); |
| 59 | const oppCol = this.getOppCol(color); |
| 60 | const V = VariantRules; |
| 61 | const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]); |
| 62 | const [sizeX,sizeY] = V.size; |
| 63 | for (let step of adjacentSteps) |
| 64 | { |
| 65 | const [i,j] = [x+step[0],y+step[1]]; |
| 66 | if (i>=0 && i<sizeX && j>=0 && j<sizeY && this.board[i][j] != V.EMPTY |
| 67 | && this.getColor(i,j) == oppCol) |
| 68 | { |
| 69 | const oppPiece = this.getPiece(i,j); |
| 70 | if (oppPiece == V.IMMOBILIZER |
| 71 | || (oppPiece == V.BISHOP && piece == V.IMMOBILIZER)) |
| 72 | { |
| 73 | return [ new Move({ |
| 74 | appear: [], |
| 75 | vanish: [new PiPo({x:x,y:y,p:piece,c:color})], |
| 76 | start: {x:x,y:y}, |
| 77 | end: {x:i,y:j} |
| 78 | }) ]; |
| 79 | } |
| 80 | } |
| 81 | } |
| 82 | switch (this.getPiece(x,y)) |
| 83 | { |
| 84 | case VariantRules.IMMOBILIZER: |
| 85 | return this.getPotentialImmobilizerMoves([x,y]); |
| 86 | default: |
| 87 | return super.getPotentialMovesFrom([x,y]); |
| 88 | } |
| 89 | } |
| 90 | |
| 91 | getSlideNJumpMoves([x,y], steps, oneStep) |
| 92 | { |
| 93 | const color = this.getColor(x,y); |
| 94 | const piece = this.getPiece(x,y); |
| 95 | let moves = []; |
| 96 | const [sizeX,sizeY] = VariantRules.size; |
| 97 | outerLoop: |
| 98 | for (let step of steps) |
| 99 | { |
| 100 | let i = x + step[0]; |
| 101 | let j = y + step[1]; |
| 102 | while (i>=0 && i<sizeX && j>=0 && j<sizeY |
| 103 | && this.board[i][j] == VariantRules.EMPTY) |
| 104 | { |
| 105 | moves.push(this.getBasicMove([x,y], [i,j])); |
| 106 | if (oneStep !== undefined) |
| 107 | continue outerLoop; |
| 108 | i += step[0]; |
| 109 | j += step[1]; |
| 110 | } |
| 111 | // Only king can take on occupied square: |
| 112 | if (piece==VariantRules.KING && i>=0 && i<sizeX && j>=0 |
| 113 | && j<sizeY && this.canTake([x,y], [i,j])) |
| 114 | { |
| 115 | moves.push(this.getBasicMove([x,y], [i,j])); |
| 116 | } |
| 117 | } |
| 118 | return moves; |
| 119 | } |
| 120 | |
| 121 | // Modify capturing moves among listed pawn moves |
| 122 | addPawnCaptures(moves, byChameleon) |
| 123 | { |
| 124 | const steps = VariantRules.steps[VariantRules.ROOK]; |
| 125 | const [sizeX,sizeY] = VariantRules.size; |
| 126 | const color = this.turn; |
| 127 | const oppCol = this.getOppCol(color); |
| 128 | moves.forEach(m => { |
| 129 | if (!!byChameleon && m.start.x!=m.end.x && m.start.y!=m.end.y) |
| 130 | return; //chameleon not moving as pawn |
| 131 | // Try capturing in every direction |
| 132 | for (let step of steps) |
| 133 | { |
| 134 | const sq2 = [m.end.x+2*step[0],m.end.y+2*step[1]]; |
| 135 | if (sq2[0]>=0 && sq2[0]<sizeX && sq2[1]>=0 && sq2[1]<sizeY |
| 136 | && this.board[sq2[0]][sq2[1]] != VariantRules.EMPTY |
| 137 | && this.getColor(sq2[0],sq2[1]) == color) |
| 138 | { |
| 139 | // Potential capture |
| 140 | const sq1 = [m.end.x+step[0],m.end.y+step[1]]; |
| 141 | if (this.board[sq1[0]][sq1[1]] != VariantRules.EMPTY |
| 142 | && this.getColor(sq1[0],sq1[1]) == oppCol) |
| 143 | { |
| 144 | const piece1 = this.getPiece(sq1[0],sq1[1]); |
| 145 | if (!byChameleon || piece1 == VariantRules.PAWN) |
| 146 | { |
| 147 | m.vanish.push(new PiPo({ |
| 148 | x:sq1[0], |
| 149 | y:sq1[1], |
| 150 | c:oppCol, |
| 151 | p:piece1 |
| 152 | })); |
| 153 | } |
| 154 | } |
| 155 | } |
| 156 | } |
| 157 | }); |
| 158 | } |
| 159 | |
| 160 | // "Pincher" |
| 161 | getPotentialPawnMoves([x,y]) |
| 162 | { |
| 163 | let moves = super.getPotentialRookMoves([x,y]); |
| 164 | this.addPawnCaptures(moves); |
| 165 | return moves; |
| 166 | } |
| 167 | |
| 168 | addRookCaptures(moves, byChameleon) |
| 169 | { |
| 170 | const color = this.turn; |
| 171 | const oppCol = this.getOppCol(color); |
| 172 | const kp = this.kingPos[color]; |
| 173 | moves.forEach(m => { |
| 174 | // Check piece-king rectangle (if any) corners for enemy pieces |
| 175 | if (m.end.x == kp[0] || m.end.y == kp[1]) |
| 176 | return; //"flat rectangle" |
| 177 | const corner1 = [Math.max(m.end.x,kp[0]), Math.min(m.end.y,kp[1])]; |
| 178 | const corner2 = [Math.min(m.end.x,kp[0]), Math.max(m.end.y,kp[1])]; |
| 179 | for (let [i,j] of [corner1,corner2]) |
| 180 | { |
| 181 | if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) == oppCol) |
| 182 | { |
| 183 | const piece = this.getPiece(i,j); |
| 184 | if (!byChameleon || piece == VariantRules.ROOK) |
| 185 | { |
| 186 | m.vanish.push( new PiPo({ |
| 187 | x:i, |
| 188 | y:j, |
| 189 | p:piece, |
| 190 | c:oppCol |
| 191 | }) ); |
| 192 | } |
| 193 | } |
| 194 | } |
| 195 | }); |
| 196 | } |
| 197 | |
| 198 | // Coordinator |
| 199 | getPotentialRookMoves(sq) |
| 200 | { |
| 201 | let moves = super.getPotentialQueenMoves(sq); |
| 202 | this.addRookCaptures(moves); |
| 203 | return moves; |
| 204 | } |
| 205 | |
| 206 | // Long-leaper |
| 207 | getKnightCaptures(startSquare, byChameleon) |
| 208 | { |
| 209 | // Look in every direction for captures |
| 210 | const V = VariantRules; |
| 211 | const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]); |
| 212 | const [sizeX,sizeY] = V.size; |
| 213 | const color = this.turn; |
| 214 | const oppCol = this.getOppCol(color); |
| 215 | let moves = []; |
| 216 | const [x,y] = [startSquare[0],startSquare[1]]; |
| 217 | const piece = this.getPiece(x,y); //might be a chameleon! |
| 218 | outerLoop: |
| 219 | for (let step of steps) |
| 220 | { |
| 221 | let [i,j] = [x+step[0], y+step[1]]; |
| 222 | while (i>=0 && i<sizeX && j>=0 && j<sizeY && this.board[i][j]==V.EMPTY) |
| 223 | { |
| 224 | i += step[0]; |
| 225 | j += step[1]; |
| 226 | } |
| 227 | if (i<0 || i>=sizeX || j<0 || j>=sizeY || this.getColor(i,j)==color |
| 228 | || (!!byChameleon && this.getPiece(i,j)!=V.KNIGHT)) |
| 229 | { |
| 230 | continue; |
| 231 | } |
| 232 | // last(thing), cur(thing) : stop if "cur" is our color, or beyond board limits, |
| 233 | // or if "last" isn't empty and cur neither. Otherwise, if cur is empty then |
| 234 | // add move until cur square; if cur is occupied then stop if !!byChameleon and |
| 235 | // the square not occupied by a leaper. |
| 236 | let last = [i,j]; |
| 237 | let cur = [i+step[0],j+step[1]]; |
| 238 | let vanished = [ new PiPo({x:x,y:y,c:color,p:piece}) ]; |
| 239 | while (cur[0]>=0 && cur[0]<sizeX && cur[1]>=0 && cur[1]<sizeY) |
| 240 | { |
| 241 | if (this.board[last[0]][last[1]] != V.EMPTY) |
| 242 | { |
| 243 | const oppPiece = this.getPiece(last[0],last[1]); |
| 244 | if (!!byChameleon && oppPiece != V.KNIGHT) |
| 245 | continue outerLoop; |
| 246 | // Something to eat: |
| 247 | vanished.push( new PiPo({x:last[0],y:last[1],c:oppCol,p:oppPiece}) ); |
| 248 | } |
| 249 | if (this.board[cur[0]][cur[1]] != V.EMPTY) |
| 250 | { |
| 251 | if (this.getColor(cur[0],cur[1]) == color |
| 252 | || this.board[last[0]][last[1]] != V.EMPTY) //TODO: redundant test |
| 253 | { |
| 254 | continue outerLoop; |
| 255 | } |
| 256 | } |
| 257 | else |
| 258 | { |
| 259 | moves.push(new Move({ |
| 260 | appear: [ new PiPo({x:cur[0],y:cur[1],c:color,p:piece}) ], |
| 261 | vanish: JSON.parse(JSON.stringify(vanished)), //TODO: required? |
| 262 | start: {x:x,y:y}, |
| 263 | end: {x:cur[0],y:cur[1]} |
| 264 | })); |
| 265 | } |
| 266 | last = [last[0]+step[0],last[1]+step[1]]; |
| 267 | cur = [cur[0]+step[0],cur[1]+step[1]]; |
| 268 | } |
| 269 | } |
| 270 | return moves; |
| 271 | } |
| 272 | |
| 273 | // Long-leaper |
| 274 | getPotentialKnightMoves(sq) |
| 275 | { |
| 276 | return super.getPotentialQueenMoves(sq).concat(this.getKnightCaptures(sq)); |
| 277 | } |
| 278 | |
| 279 | getPotentialBishopMoves([x,y]) |
| 280 | { |
| 281 | let moves = super.getPotentialQueenMoves([x,y]) |
| 282 | .concat(this.getKnightCaptures([x,y],"asChameleon")); |
| 283 | this.addPawnCaptures(moves, "asChameleon"); |
| 284 | this.addRookCaptures(moves, "asChameleon"); |
| 285 | this.addQueenCaptures(moves, "asChameleon"); |
| 286 | // Add king capture if it's within range |
| 287 | const oppKp = this.kingPos[this.getOppCol(this.turn)]; |
| 288 | if (Math.abs(x-oppKp[0]) <= 1 && Math.abs(y-oppKp[1]) <= 1) |
| 289 | moves.push(this.getBasicMove([x,y],oppKp)); |
| 290 | // Post-processing: merge similar moves, concatenating vanish arrays |
| 291 | let mergedMoves = {}; |
| 292 | const [sizeX,sizeY] = VariantRules.size; |
| 293 | moves.forEach(m => { |
| 294 | const key = m.end.x + sizeX * m.end.y; |
| 295 | if (!mergedMoves[key]) |
| 296 | mergedMoves[key] = m; |
| 297 | else |
| 298 | { |
| 299 | for (let i=1; i<m.vanish.length; i++) |
| 300 | mergedMoves[key].vanish.push(m.vanish[i]); |
| 301 | } |
| 302 | }); |
| 303 | // Finally return an array |
| 304 | moves = []; |
| 305 | Object.keys(mergedMoves).forEach(k => { moves.push(mergedMoves[k]); }); |
| 306 | return moves; |
| 307 | } |
| 308 | |
| 309 | // Withdrawer |
| 310 | addQueenCaptures(moves, byChameleon) |
| 311 | { |
| 312 | if (moves.length == 0) |
| 313 | return; |
| 314 | const [x,y] = [moves[0].start.x,moves[0].start.y]; |
| 315 | const V = VariantRules; |
| 316 | const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]); |
| 317 | let capturingDirections = []; |
| 318 | const color = this.turn; |
| 319 | const oppCol = this.getOppCol(color); |
| 320 | const [sizeX,sizeY] = V.size; |
| 321 | adjacentSteps.forEach(step => { |
| 322 | const [i,j] = [x+step[0],y+step[1]]; |
| 323 | if (i>=0 && i<sizeX && j>=0 && j<sizeY |
| 324 | && this.board[i][j] != V.EMPTY && this.getColor(i,j) == oppCol |
| 325 | && (!byChameleon || this.getPiece(i,j) == V.QUEEN)) |
| 326 | { |
| 327 | capturingDirections.push(step); |
| 328 | } |
| 329 | }); |
| 330 | moves.forEach(m => { |
| 331 | const step = [ |
| 332 | m.end.x!=x ? (m.end.x-x)/Math.abs(m.end.x-x) : 0, |
| 333 | m.end.y!=y ? (m.end.y-y)/Math.abs(m.end.y-y) : 0 |
| 334 | ]; |
| 335 | // NOTE: includes() and even _.isEqual() functions fail... |
| 336 | // TODO: this test should be done only once per direction |
| 337 | if (capturingDirections.some(dir => |
| 338 | { return (dir[0]==-step[0] && dir[1]==-step[1]); })) |
| 339 | { |
| 340 | const [i,j] = [x-step[0],y-step[1]]; |
| 341 | m.vanish.push(new PiPo({ |
| 342 | x:i, |
| 343 | y:j, |
| 344 | p:this.getPiece(i,j), |
| 345 | c:oppCol |
| 346 | })); |
| 347 | } |
| 348 | }); |
| 349 | } |
| 350 | |
| 351 | getPotentialQueenMoves(sq) |
| 352 | { |
| 353 | let moves = super.getPotentialQueenMoves(sq); |
| 354 | this.addQueenCaptures(moves); |
| 355 | return moves; |
| 356 | } |
| 357 | |
| 358 | getPotentialImmobilizerMoves(sq) |
| 359 | { |
| 360 | // Immobilizer doesn't capture |
| 361 | return super.getPotentialQueenMoves(sq); |
| 362 | } |
| 363 | |
| 364 | getPotentialKingMoves(sq) |
| 365 | { |
| 366 | const V = VariantRules; |
| 367 | return this.getSlideNJumpMoves(sq, |
| 368 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep"); |
| 369 | } |
| 370 | |
| 371 | // TODO: verify this assertion |
| 372 | atLeastOneMove() |
| 373 | { |
| 374 | return true; //always at least one possible move |
| 375 | } |
| 376 | |
| 377 | underCheck(move) |
| 378 | { |
| 379 | return false; //there is no check |
| 380 | } |
| 381 | |
| 382 | getCheckSquares(move) |
| 383 | { |
| 384 | const c = this.getOppCol(this.turn); //opponent |
| 385 | const saveKingPos = this.kingPos[c]; //king might be taken |
| 386 | this.play(move); |
| 387 | // The only way to be "under check" is to have lost the king (thus game over) |
| 388 | let res = this.kingPos[c][0] < 0 |
| 389 | ? [ JSON.parse(JSON.stringify(saveKingPos)) ] |
| 390 | : [ ]; |
| 391 | this.undo(move); |
| 392 | return res; |
| 393 | } |
| 394 | |
| 395 | updateVariables(move) |
| 396 | { |
| 397 | // Just update king(s) position(s) |
| 398 | const piece = this.getPiece(move.start.x,move.start.y); |
| 399 | const c = this.getColor(move.start.x,move.start.y); |
| 400 | if (piece == VariantRules.KING && move.appear.length > 0) |
| 401 | { |
| 402 | this.kingPos[c][0] = move.appear[0].x; |
| 403 | this.kingPos[c][1] = move.appear[0].y; |
| 404 | } |
| 405 | // Does this move takes opponent's king? |
| 406 | const oppCol = this.getOppCol(c); |
| 407 | for (let psq of move.vanish) |
| 408 | { |
| 409 | if (psq.p == VariantRules.KING) |
| 410 | { |
| 411 | this.kingPos[oppCol] = [-1,-1]; |
| 412 | break; |
| 413 | } |
| 414 | } |
| 415 | } |
| 416 | |
| 417 | unupdateVariables(move) |
| 418 | { |
| 419 | super.unupdateVariables(move); |
| 420 | const c = this.getColor(move.start.x,move.start.y); |
| 421 | const oppCol = this.getOppCol(c); |
| 422 | if (this.kingPos[oppCol][0] < 0) |
| 423 | { |
| 424 | // Last move took opponent's king |
| 425 | for (let psq of move.vanish) |
| 426 | { |
| 427 | if (psq.p == 'k') |
| 428 | { |
| 429 | this.kingPos[oppCol] = [psq.x, psq.y]; |
| 430 | break; |
| 431 | } |
| 432 | } |
| 433 | } |
| 434 | } |
| 435 | |
| 436 | checkGameOver() |
| 437 | { |
| 438 | if (this.checkRepetition()) |
| 439 | return "1/2"; |
| 440 | |
| 441 | const color = this.turn; |
| 442 | // TODO: do we need "atLeastOneMove()"? |
| 443 | if (this.atLeastOneMove() && this.kingPos[color][0] >= 0) |
| 444 | return "*"; |
| 445 | |
| 446 | return this.checkGameEnd(); |
| 447 | } |
| 448 | |
| 449 | checkGameEnd() |
| 450 | { |
| 451 | // No valid move: our king disappeared |
| 452 | return this.turn == "w" ? "0-1" : "1-0"; |
| 453 | } |
| 454 | |
| 455 | static get VALUES() { //TODO: totally experimental! |
| 456 | return { |
| 457 | 'p': 1, |
| 458 | 'r': 2, |
| 459 | 'n': 5, |
| 460 | 'b': 3, |
| 461 | 'q': 3, |
| 462 | 'm': 5, |
| 463 | 'k': 1000 |
| 464 | }; |
| 465 | } |
| 466 | |
| 467 | static get SEARCH_DEPTH() { return 2; } //TODO? |
| 468 | |
| 469 | static get THRESHOLD_MATE() { |
| 470 | return 500; //checkmates evals may be slightly below 1000 |
| 471 | } |
| 472 | |
| 473 | static GenRandInitFen() |
| 474 | { |
| 475 | let pieces = { "w": new Array(8), "b": new Array(8) }; |
| 476 | // Shuffle pieces on first and last rank |
| 477 | for (let c of ["w","b"]) |
| 478 | { |
| 479 | let positions = _.range(8); |
| 480 | // Get random squares for every piece, totally freely |
| 481 | |
| 482 | let randIndex = _.random(7); |
| 483 | const bishop1Pos = positions[randIndex]; |
| 484 | positions.splice(randIndex, 1); |
| 485 | |
| 486 | randIndex = _.random(6); |
| 487 | const bishop2Pos = positions[randIndex]; |
| 488 | positions.splice(randIndex, 1); |
| 489 | |
| 490 | randIndex = _.random(5); |
| 491 | const knight1Pos = positions[randIndex]; |
| 492 | positions.splice(randIndex, 1); |
| 493 | |
| 494 | randIndex = _.random(4); |
| 495 | const knight2Pos = positions[randIndex]; |
| 496 | positions.splice(randIndex, 1); |
| 497 | |
| 498 | randIndex = _.random(3); |
| 499 | const queenPos = positions[randIndex]; |
| 500 | positions.splice(randIndex, 1); |
| 501 | |
| 502 | randIndex = _.random(2); |
| 503 | const kingPos = positions[randIndex]; |
| 504 | positions.splice(randIndex, 1); |
| 505 | |
| 506 | randIndex = _.random(1); |
| 507 | const rookPos = positions[randIndex]; |
| 508 | positions.splice(randIndex, 1); |
| 509 | const immobilizerPos = positions[0]; |
| 510 | |
| 511 | pieces[c][bishop1Pos] = 'b'; |
| 512 | pieces[c][bishop2Pos] = 'b'; |
| 513 | pieces[c][knight1Pos] = 'n'; |
| 514 | pieces[c][knight2Pos] = 'n'; |
| 515 | pieces[c][queenPos] = 'q'; |
| 516 | pieces[c][kingPos] = 'k'; |
| 517 | pieces[c][rookPos] = 'r'; |
| 518 | pieces[c][immobilizerPos] = 'm'; |
| 519 | } |
| 520 | return pieces["b"].join("") + |
| 521 | "/pppppppp/8/8/8/8/PPPPPPPP/" + |
| 522 | pieces["w"].join("").toUpperCase() + |
| 523 | " 0000"; //TODO: flags?! |
| 524 | } |
| 525 | |
| 526 | getFlagsFen() |
| 527 | { |
| 528 | return "0000"; //TODO: or "-" ? |
| 529 | } |
| 530 | |
| 531 | getNotation(move) |
| 532 | { |
| 533 | if (move.appear.length == 0) |
| 534 | { |
| 535 | const startSquare = |
| 536 | String.fromCharCode(97 + move.start.y) + (VariantRules.size[0]-move.start.x); |
| 537 | return "^" + startSquare; //suicide |
| 538 | } |
| 539 | return super.getNotation(move); |
| 540 | } |
| 541 | } |