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