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