public/javascripts/variants/Grand.js

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