public/javascripts/variants/Wildebeest.js

   1 class WildebeestRules extends ChessRules
   2 {
   3     static getPpath(b)
   4     {
   5         return ([V.CAMEL,V.WILDEBEEST].includes(b[1]) ? "Wildebeest/" : "") + b;
   6     }
   7
   8     static get size() { return {x:10,y:11}; }
   9
  10     static get CAMEL() { return 'c'; }
  11     static get WILDEBEEST() { return 'w'; }
  12
  13     static get PIECES()
  14     {
  15         return ChessRules.PIECES.concat([V.CAMEL,V.WILDEBEEST]);
  16     }
  17
  18     static get steps()
  19     {
  20         return Object.assign(
  21             ChessRules.steps, //add camel moves:
  22             {'c': [ [-3,-1],[-3,1],[-1,-3],[-1,3],[1,-3],[1,3],[3,-1],[3,1] ]}
  23         );
  24     }
  25
  26     static IsGoodEnpassant(enpassant)
  27     {
  28         if (enpassant != "-")
  29         {
  30             const squares = enpassant.split(",");
  31             if (squares.length > 2)
  32                 return false;
  33             for (let sq of squares)
  34             {
  35                 const ep = V.SquareToCoords(sq);
  36                 if (isNaN(ep.x) || !V.OnBoard(ep))
  37                     return false;
  38             }
  39         }
  40         return true;
  41     }
  42
  43     // There may be 2 enPassant squares (if pawn jump 3 squares)
  44     getEnpassantFen()
  45     {
  46         const L = this.epSquares.length;
  47         if (!this.epSquares[L-1])
  48             return "-"; //no en-passant
  49         let res = "";
  50         this.epSquares[L-1].forEach(sq => {
  51             res += V.CoordsToSquare(sq) + ",";
  52         });
  53         return res.slice(0,-1); //remove last comma
  54     }
  55
  56     // En-passant after 2-sq or 3-sq jumps
  57     getEpSquare(moveOrSquare)
  58     {
  59         if (!moveOrSquare)
  60             return undefined;
  61         if (typeof moveOrSquare === "string")
  62         {
  63             const square = moveOrSquare;
  64             if (square == "-")
  65                 return undefined;
  66             let res = [];
  67             square.split(",").forEach(sq => {
  68                 res.push(V.SquareToCoords(sq));
  69             });
  70             return res;
  71         }
  72         // Argument is a move:
  73         const move = moveOrSquare;
  74         const [sx,sy,ex] = [move.start.x,move.start.y,move.end.x];
  75         if (this.getPiece(sx,sy) == V.PAWN && Math.abs(sx - ex) >= 2)
  76         {
  77             const step = (ex-sx) / Math.abs(ex-sx);
  78             let res = [{
  79                 x: sx + step,
  80                 y: sy
  81             }];
  82             if (sx + 2*step != ex) //3-squares move
  83             {
  84                 res.push({
  85                     x: sx + 2*step,
  86                     y: sy
  87                 });
  88             }
  89             return res;
  90         }
  91         return undefined; //default
  92     }
  93
  94     getPotentialMovesFrom([x,y])
  95     {
  96         switch (this.getPiece(x,y))
  97         {
  98             case V.CAMEL:
  99                 return this.getPotentialCamelMoves([x,y]);
 100             case V.WILDEBEEST:
 101                 return this.getPotentialWildebeestMoves([x,y]);
 102             default:
 103                 return super.getPotentialMovesFrom([x,y])
 104         }
 105     }
 106
 107     // Pawns jump 2 or 3 squares, and promote to queen or wildebeest
 108     getPotentialPawnMoves([x,y])
 109     {
 110         const color = this.turn;
 111         let moves = [];
 112         const [sizeX,sizeY] = [V.size.x,V.size.y];
 113         const shift = (color == "w" ? -1 : 1);
 114         const startRanks = (color == "w" ? [sizeX-2,sizeX-3] : [1,2]);
 115         const lastRank = (color == "w" ? 0 : sizeX-1);
 116
 117         if (x+shift >= 0 && x+shift < sizeX && x+shift != lastRank)
 118         {
 119             // Normal moves
 120             if (this.board[x+shift][y] == V.EMPTY)
 121             {
 122                 moves.push(this.getBasicMove([x,y], [x+shift,y]));
 123                 if (startRanks.includes(x) && this.board[x+2*shift][y] == V.EMPTY)
 124                 {
 125                     // Two squares jump
 126                     moves.push(this.getBasicMove([x,y], [x+2*shift,y]));
 127                     if (x == startRanks[0] && this.board[x+3*shift][y] == V.EMPTY)
 128                     {
 129                         // 3-squares jump
 130                         moves.push(this.getBasicMove([x,y], [x+3*shift,y]));
 131                     }
 132                 }
 133             }
 134             // Captures
 135             if (y>0 && this.canTake([x,y], [x+shift,y-1])
 136                 && this.board[x+shift][y-1] != V.EMPTY)
 137             {
 138                 moves.push(this.getBasicMove([x,y], [x+shift,y-1]));
 139             }
 140             if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1])
 141                 && this.board[x+shift][y+1] != V.EMPTY)
 142             {
 143                 moves.push(this.getBasicMove([x,y], [x+shift,y+1]));
 144             }
 145         }
 146
 147         if (x+shift == lastRank)
 148         {
 149             // Promotion
 150             let promotionPieces = [V.QUEEN,V.WILDEBEEST];
 151             promotionPieces.forEach(p => {
 152                 // Normal move
 153                 if (this.board[x+shift][y] == V.EMPTY)
 154                     moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:p}));
 155                 // Captures
 156                 if (y>0 && this.canTake([x,y], [x+shift,y-1])
 157                     && this.board[x+shift][y-1] != V.EMPTY)
 158                 {
 159                     moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:color,p:p}));
 160                 }
 161                 if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1])
 162                     && this.board[x+shift][y+1] != V.EMPTY)
 163                 {
 164                     moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:color,p:p}));
 165                 }
 166             });
 167         }
 168
 169         // En passant
 170         const Lep = this.epSquares.length;
 171         const epSquare = Lep>0 ? this.epSquares[Lep-1] : undefined;
 172         if (!!epSquare)
 173         {
 174             for (let epsq of epSquare)
 175             {
 176                 // TODO: some redundant checks
 177                 if (epsq.x == x+shift && Math.abs(epsq.y - y) == 1)
 178                 {
 179                     var enpassantMove = this.getBasicMove([x,y], [x+shift,epsq.y]);
 180                     enpassantMove.vanish.push({
 181                         x: x,
 182                         y: epsq.y,
 183                         p: 'p',
 184                         c: this.getColor(x,epsq.y)
 185                     });
 186                     moves.push(enpassantMove);
 187                 }
 188             }
 189         }
 190
 191         return moves;
 192     }
 193
 194     // TODO: wildebeest castle
 195
 196     getPotentialCamelMoves(sq)
 197     {
 198         return this.getSlideNJumpMoves(sq, V.steps[V.CAMEL], "oneStep");
 199     }
 200
 201     getPotentialWildebeestMoves(sq)
 202     {
 203         return this.getSlideNJumpMoves(
 204             sq, V.steps[V.KNIGHT].concat(V.steps[V.CAMEL]), "oneStep");
 205     }
 206
 207     isAttacked(sq, colors)
 208     {
 209         return super.isAttacked(sq, colors)
 210             || this.isAttackedByCamel(sq, colors)
 211             || this.isAttackedByWildebeest(sq, colors);
 212     }
 213
 214     isAttackedByCamel(sq, colors)
 215     {
 216         return this.isAttackedBySlideNJump(sq, colors,
 217             V.CAMEL, V.steps[V.CAMEL], "oneStep");
 218     }
 219
 220     isAttackedByWildebeest(sq, colors)
 221     {
 222         return this.isAttackedBySlideNJump(sq, colors, V.WILDEBEEST,
 223             V.steps[V.KNIGHT].concat(V.steps[V.CAMEL]), "oneStep");
 224     }
 225
 226     checkGameEnd()
 227     {
 228         // No valid move: game is lost (stalemate is a win)
 229         return this.turn == "w" ? "0-1" : "1-0";
 230     }
 231
 232     static get VALUES() {
 233         return Object.assign(
 234             ChessRules.VALUES,
 235             {'c': 3, 'w': 7} //experimental
 236         );
 237     }
 238
 239     static get SEARCH_DEPTH() { return 2; }
 240
 241     static GenRandInitFen()
 242     {
 243         let pieces = { "w": new Array(10), "b": new Array(10) };
 244         for (let c of ["w","b"])
 245         {
 246             let positions = _.range(11);
 247
 248             // Get random squares for bishops + camels (different colors)
 249             let randIndexes = _.sample(_.range(6), 2).map(i => { return 2*i; });
 250             let bishop1Pos = positions[randIndexes[0]];
 251             let camel1Pos = positions[randIndexes[1]];
 252             // The second bishop (camel) must be on a square of different color
 253             let randIndexes_tmp = _.sample(_.range(5), 2).map(i => { return 2*i+1; });
 254             let bishop2Pos = positions[randIndexes_tmp[0]];
 255             let camel2Pos = positions[randIndexes_tmp[1]];
 256             for (let idx of randIndexes.concat(randIndexes_tmp)
 257                 .sort((a,b) => { return b-a; })) //largest indices first
 258             {
 259                 positions.splice(idx, 1);
 260             }
 261
 262             let randIndex = _.random(6);
 263             let knight1Pos = positions[randIndex];
 264             positions.splice(randIndex, 1);
 265             randIndex = _.random(5);
 266             let knight2Pos = positions[randIndex];
 267             positions.splice(randIndex, 1);
 268
 269             randIndex = _.random(4);
 270             let queenPos = positions[randIndex];
 271             positions.splice(randIndex, 1);
 272
 273             // Random square for wildebeest
 274             randIndex = _.random(3);
 275             let wildebeestPos = positions[randIndex];
 276             positions.splice(randIndex, 1);
 277
 278             let rook1Pos = positions[0];
 279             let kingPos = positions[1];
 280             let rook2Pos = positions[2];
 281
 282             pieces[c][rook1Pos] = 'r';
 283             pieces[c][knight1Pos] = 'n';
 284             pieces[c][bishop1Pos] = 'b';
 285             pieces[c][queenPos] = 'q';
 286             pieces[c][camel1Pos] = 'c';
 287             pieces[c][camel2Pos] = 'c';
 288             pieces[c][wildebeestPos] = 'w';
 289             pieces[c][kingPos] = 'k';
 290             pieces[c][bishop2Pos] = 'b';
 291             pieces[c][knight2Pos] = 'n';
 292             pieces[c][rook2Pos] = 'r';
 293         }
 294         return pieces["b"].join("") +
 295             "/ppppppppppp/11/11/11/11/11/11/PPPPPPPPPPP/" +
 296             pieces["w"].join("").toUpperCase() +
 297             " w 1111 -";
 298     }
 299 }
 300
 301 const VariantRules = WildebeestRules;