client/src/variants/Grand.js

   1 import { ChessRules } from "@/base_rules";
   2 import { ArrayFun } from "@/utils/array";
   3 import { randInt } from "@/utils/alea";
   4
   5 // NOTE: initial setup differs from the original; see
   6 // https://www.chessvariants.com/large.dir/freeling.html
   7 export const VariantRules = class GrandRules extends ChessRules {
   8   static IsGoodFen(fen) {
   9     if (!ChessRules.IsGoodFen(fen)) return false;
  10     const fenParsed = V.ParseFen(fen);
  11     // 5) Check captures
  12     if (!fenParsed.captured || !fenParsed.captured.match(/^[0-9]{14,14}$/))
  13       return false;
  14     return true;
  15   }
  16
  17   static IsGoodEnpassant(enpassant) {
  18     if (enpassant != "-") {
  19       const squares = enpassant.split(",");
  20       if (squares.length > 2) return false;
  21       for (let sq of squares) {
  22         const ep = V.SquareToCoords(sq);
  23         if (isNaN(ep.x) || !V.OnBoard(ep)) return false;
  24       }
  25     }
  26     return true;
  27   }
  28
  29   static ParseFen(fen) {
  30     const fenParts = fen.split(" ");
  31     return Object.assign(ChessRules.ParseFen(fen), { captured: fenParts[5] });
  32   }
  33
  34   getPpath(b) {
  35     return ([V.MARSHALL, V.CARDINAL].includes(b[1]) ? "Grand/" : "") + b;
  36   }
  37
  38   getFen() {
  39     return super.getFen() + " " + this.getCapturedFen();
  40   }
  41
  42   getFenForRepeat() {
  43     return super.getFenForRepeat() + "_" + this.getCapturedFen();
  44   }
  45
  46   getCapturedFen() {
  47     let counts = [...Array(14).fill(0)];
  48     let i = 0;
  49     for (let j = 0; j < V.PIECES.length; j++) {
  50       if (V.PIECES[j] == V.KING)
  51         //no king captured
  52         continue;
  53       counts[i] = this.captured["w"][V.PIECES[i]];
  54       counts[7 + i] = this.captured["b"][V.PIECES[i]];
  55       i++;
  56     }
  57     return counts.join("");
  58   }
  59
  60   setOtherVariables(fen) {
  61     super.setOtherVariables(fen);
  62     const fenParsed = V.ParseFen(fen);
  63     // Initialize captured pieces' counts from FEN
  64     this.captured = {
  65       w: {
  66         [V.PAWN]: parseInt(fenParsed.captured[0]),
  67         [V.ROOK]: parseInt(fenParsed.captured[1]),
  68         [V.KNIGHT]: parseInt(fenParsed.captured[2]),
  69         [V.BISHOP]: parseInt(fenParsed.captured[3]),
  70         [V.QUEEN]: parseInt(fenParsed.captured[4]),
  71         [V.MARSHALL]: parseInt(fenParsed.captured[5]),
  72         [V.CARDINAL]: parseInt(fenParsed.captured[6])
  73       },
  74       b: {
  75         [V.PAWN]: parseInt(fenParsed.captured[7]),
  76         [V.ROOK]: parseInt(fenParsed.captured[8]),
  77         [V.KNIGHT]: parseInt(fenParsed.captured[9]),
  78         [V.BISHOP]: parseInt(fenParsed.captured[10]),
  79         [V.QUEEN]: parseInt(fenParsed.captured[11]),
  80         [V.MARSHALL]: parseInt(fenParsed.captured[12]),
  81         [V.CARDINAL]: parseInt(fenParsed.captured[13])
  82       }
  83     };
  84   }
  85
  86   static get size() {
  87     return { x: 10, y: 10 };
  88   }
  89
  90   static get MARSHALL() {
  91     return "m";
  92   } //rook+knight
  93   static get CARDINAL() {
  94     return "c";
  95   } //bishop+knight
  96
  97   static get PIECES() {
  98     return ChessRules.PIECES.concat([V.MARSHALL, V.CARDINAL]);
  99   }
 100
 101   // There may be 2 enPassant squares (if pawn jump 3 squares)
 102   getEnpassantFen() {
 103     const L = this.epSquares.length;
 104     if (!this.epSquares[L - 1]) return "-"; //no en-passant
 105     let res = "";
 106     this.epSquares[L - 1].forEach(sq => {
 107       res += V.CoordsToSquare(sq) + ",";
 108     });
 109     return res.slice(0, -1); //remove last comma
 110   }
 111
 112   // En-passant after 2-sq or 3-sq jumps
 113   getEpSquare(moveOrSquare) {
 114     if (!moveOrSquare) return undefined;
 115     if (typeof moveOrSquare === "string") {
 116       const square = moveOrSquare;
 117       if (square == "-") return undefined;
 118       let res = [];
 119       square.split(",").forEach(sq => {
 120         res.push(V.SquareToCoords(sq));
 121       });
 122       return res;
 123     }
 124     // Argument is a move:
 125     const move = moveOrSquare;
 126     const [sx, sy, ex] = [move.start.x, move.start.y, move.end.x];
 127     if (this.getPiece(sx, sy) == V.PAWN && Math.abs(sx - ex) >= 2) {
 128       const step = (ex - sx) / Math.abs(ex - sx);
 129       let res = [
 130         {
 131           x: sx + step,
 132           y: sy
 133         }
 134       ];
 135       if (sx + 2 * step != ex) {
 136         //3-squares move
 137         res.push({
 138           x: sx + 2 * step,
 139           y: sy
 140         });
 141       }
 142       return res;
 143     }
 144     return undefined; //default
 145   }
 146
 147   getPotentialMovesFrom([x, y]) {
 148     switch (this.getPiece(x, y)) {
 149       case V.MARSHALL:
 150         return this.getPotentialMarshallMoves([x, y]);
 151       case V.CARDINAL:
 152         return this.getPotentialCardinalMoves([x, y]);
 153       default:
 154         return super.getPotentialMovesFrom([x, y]);
 155     }
 156   }
 157
 158   // Special pawn rules: promotions to captured friendly pieces,
 159   // optional on ranks 8-9 and mandatory on rank 10.
 160   getPotentialPawnMoves([x, y]) {
 161     const color = this.turn;
 162     let moves = [];
 163     const [sizeX, sizeY] = [V.size.x, V.size.y];
 164     const shiftX = color == "w" ? -1 : 1;
 165     const startRanks = color == "w" ? [sizeX - 2, sizeX - 3] : [1, 2];
 166     const lastRanks =
 167       color == "w" ? [0, 1, 2] : [sizeX - 1, sizeX - 2, sizeX - 3];
 168     const promotionPieces = [
 169       V.ROOK,
 170       V.KNIGHT,
 171       V.BISHOP,
 172       V.QUEEN,
 173       V.MARSHALL,
 174       V.CARDINAL
 175     ];
 176
 177     // Always x+shiftX >= 0 && x+shiftX < sizeX, because no pawns on last rank
 178     let finalPieces = undefined;
 179     if (lastRanks.includes(x + shiftX)) {
 180       finalPieces = promotionPieces.filter(p => this.captured[color][p] > 0);
 181       if (x + shiftX != lastRanks[0]) finalPieces.push(V.PAWN);
 182     } else finalPieces = [V.PAWN];
 183     if (this.board[x + shiftX][y] == V.EMPTY) {
 184       // One square forward
 185       for (let piece of finalPieces)
 186         moves.push(
 187           this.getBasicMove([x, y], [x + shiftX, y], { c: color, p: piece })
 188         );
 189       if (startRanks.includes(x)) {
 190         if (this.board[x + 2 * shiftX][y] == V.EMPTY) {
 191           // Two squares jump
 192           moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
 193           if (x == startRanks[0] && this.board[x + 3 * shiftX][y] == V.EMPTY) {
 194             // Three squares jump
 195             moves.push(this.getBasicMove([x, y], [x + 3 * shiftX, y]));
 196           }
 197         }
 198       }
 199     }
 200     // Captures
 201     for (let shiftY of [-1, 1]) {
 202       if (
 203         y + shiftY >= 0 &&
 204         y + shiftY < sizeY &&
 205         this.board[x + shiftX][y + shiftY] != V.EMPTY &&
 206         this.canTake([x, y], [x + shiftX, y + shiftY])
 207       ) {
 208         for (let piece of finalPieces) {
 209           moves.push(
 210             this.getBasicMove([x, y], [x + shiftX, y + shiftY], {
 211               c: color,
 212               p: piece
 213             })
 214           );
 215         }
 216       }
 217     }
 218
 219     // En passant
 220     const Lep = this.epSquares.length;
 221     const epSquare = this.epSquares[Lep - 1];
 222     if (epSquare) {
 223       for (let epsq of epSquare) {
 224         // TODO: some redundant checks
 225         if (epsq.x == x + shiftX && Math.abs(epsq.y - y) == 1) {
 226           var enpassantMove = this.getBasicMove([x, y], [epsq.x, epsq.y]);
 227           // WARNING: the captured pawn may be diagonally behind us,
 228           // if it's a 3-squares jump and we take on 1st passing square
 229           const px = this.board[x][epsq.y] != V.EMPTY ? x : x - shiftX;
 230           enpassantMove.vanish.push({
 231             x: px,
 232             y: epsq.y,
 233             p: "p",
 234             c: this.getColor(px, epsq.y)
 235           });
 236           moves.push(enpassantMove);
 237         }
 238       }
 239     }
 240
 241     return moves;
 242   }
 243
 244   // TODO: different castle?
 245
 246   getPotentialMarshallMoves(sq) {
 247     return this.getSlideNJumpMoves(sq, V.steps[V.ROOK]).concat(
 248       this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep")
 249     );
 250   }
 251
 252   getPotentialCardinalMoves(sq) {
 253     return this.getSlideNJumpMoves(sq, V.steps[V.BISHOP]).concat(
 254       this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep")
 255     );
 256   }
 257
 258   isAttacked(sq, colors) {
 259     return (
 260       super.isAttacked(sq, colors) ||
 261       this.isAttackedByMarshall(sq, colors) ||
 262       this.isAttackedByCardinal(sq, colors)
 263     );
 264   }
 265
 266   isAttackedByMarshall(sq, colors) {
 267     return (
 268       this.isAttackedBySlideNJump(sq, colors, V.MARSHALL, V.steps[V.ROOK]) ||
 269       this.isAttackedBySlideNJump(
 270         sq,
 271         colors,
 272         V.MARSHALL,
 273         V.steps[V.KNIGHT],
 274         "oneStep"
 275       )
 276     );
 277   }
 278
 279   isAttackedByCardinal(sq, colors) {
 280     return (
 281       this.isAttackedBySlideNJump(sq, colors, V.CARDINAL, V.steps[V.BISHOP]) ||
 282       this.isAttackedBySlideNJump(
 283         sq,
 284         colors,
 285         V.CARDINAL,
 286         V.steps[V.KNIGHT],
 287         "oneStep"
 288       )
 289     );
 290   }
 291
 292   updateVariables(move) {
 293     super.updateVariables(move);
 294     if (move.vanish.length == 2 && move.appear.length == 1) {
 295       // Capture: update this.captured
 296       this.captured[move.vanish[1].c][move.vanish[1].p]++;
 297     }
 298     if (move.vanish[0].p != move.appear[0].p) {
 299       // Promotion: update this.captured
 300       this.captured[move.vanish[0].c][move.appear[0].p]--;
 301     }
 302   }
 303
 304   unupdateVariables(move) {
 305     super.unupdateVariables(move);
 306     if (move.vanish.length == 2 && move.appear.length == 1)
 307       this.captured[move.vanish[1].c][move.vanish[1].p]--;
 308     if (move.vanish[0].p != move.appear[0].p)
 309       this.captured[move.vanish[0].c][move.appear[0].p]++;
 310   }
 311
 312   static get VALUES() {
 313     return Object.assign(
 314       { c: 5, m: 7 }, //experimental
 315       ChessRules.VALUES
 316     );
 317   }
 318
 319   static get SEARCH_DEPTH() {
 320     return 2;
 321   }
 322
 323   static GenRandInitFen(randomness) {
 324     if (randomness == 0) {
 325       // No castling in the official initial setup
 326       return "r8r/1nbqkmcbn1/pppppppppp/10/10/10/10/PPPPPPPPPP/1NBQKMCBN1/R8R " +
 327         "w 0 0000 - 00000000000000";
 328     }
 329
 330     let pieces = { w: new Array(10), b: new Array(10) };
 331     // Shuffle pieces on first and last rank
 332     for (let c of ["w", "b"]) {
 333       if (c == 'b' && randomness == 1) {
 334         pieces['b'] = pieces['w'];
 335         break;
 336       }
 337
 338       let positions = ArrayFun.range(10);
 339
 340       // Get random squares for bishops
 341       let randIndex = 2 * randInt(5);
 342       let bishop1Pos = positions[randIndex];
 343       // The second bishop must be on a square of different color
 344       let randIndex_tmp = 2 * randInt(5) + 1;
 345       let bishop2Pos = positions[randIndex_tmp];
 346       // Remove chosen squares
 347       positions.splice(Math.max(randIndex, randIndex_tmp), 1);
 348       positions.splice(Math.min(randIndex, randIndex_tmp), 1);
 349
 350       // Get random squares for knights
 351       randIndex = randInt(8);
 352       let knight1Pos = positions[randIndex];
 353       positions.splice(randIndex, 1);
 354       randIndex = randInt(7);
 355       let knight2Pos = positions[randIndex];
 356       positions.splice(randIndex, 1);
 357
 358       // Get random square for queen
 359       randIndex = randInt(6);
 360       let queenPos = positions[randIndex];
 361       positions.splice(randIndex, 1);
 362
 363       // ...random square for marshall
 364       randIndex = randInt(5);
 365       let marshallPos = positions[randIndex];
 366       positions.splice(randIndex, 1);
 367
 368       // ...random square for cardinal
 369       randIndex = randInt(4);
 370       let cardinalPos = positions[randIndex];
 371       positions.splice(randIndex, 1);
 372
 373       // Rooks and king positions are now fixed, because of the ordering rook-king-rook
 374       let rook1Pos = positions[0];
 375       let kingPos = positions[1];
 376       let rook2Pos = positions[2];
 377
 378       // Finally put the shuffled pieces in the board array
 379       pieces[c][rook1Pos] = "r";
 380       pieces[c][knight1Pos] = "n";
 381       pieces[c][bishop1Pos] = "b";
 382       pieces[c][queenPos] = "q";
 383       pieces[c][marshallPos] = "m";
 384       pieces[c][cardinalPos] = "c";
 385       pieces[c][kingPos] = "k";
 386       pieces[c][bishop2Pos] = "b";
 387       pieces[c][knight2Pos] = "n";
 388       pieces[c][rook2Pos] = "r";
 389     }
 390     return (
 391       pieces["b"].join("") +
 392       "/pppppppppp/10/10/10/10/10/10/PPPPPPPPPP/" +
 393       pieces["w"].join("").toUpperCase() +
 394       " w 0 1111 - 00000000000000"
 395     );
 396   }
 397 };