public/javascripts/variants/Grand.js

   1 //https://www.chessvariants.com/large.dir/freeling.html
   2 class GrandRules extends ChessRules
   3 {
   4     static getPpath(b)
   5     {
   6         const V = VariantRules;
   7         return ([V.MARSHALL,V.CARDINAL].includes(b[1]) ? "Grand/" : "") + b;
   8     }
   9
  10     initVariables(fen)
  11     {
  12         super.initVariables(fen);
  13         this.captures = { "w": {}, "b": {} }; //for promotions
  14     }
  15
  16     static get size() { return [10,10]; }
  17
  18     static get MARSHALL() { return 'm'; } //rook+knight
  19     static get CARDINAL() { return 'c'; } //bishop+knight
  20
  21     // En-passant after 2-sq or 3-sq jumps
  22     getEpSquare(move)
  23     {
  24         const [sx,sy,ex] = [move.start.x,move.start.y,move.end.x];
  25         if (this.getPiece(sx,sy) == VariantRules.PAWN && Math.abs(sx - ex) >= 2)
  26         {
  27             const step = (ex-sx) / Math.abs(ex-sx);
  28             let res = [{
  29                 x: sx + step,
  30                 y: sy
  31             }];
  32             if (sx + 2*step != ex) //3-squares move
  33             {
  34                 res.push({
  35                     x: sx + 2*step,
  36                     y: sy
  37                 });
  38             }
  39             return res;
  40         }
  41         return undefined; //default
  42     }
  43
  44     getPotentialMovesFrom([x,y])
  45     {
  46         switch (this.getPiece(x,y))
  47         {
  48             case VariantRules.MARSHALL:
  49                 return this.getPotentialMarshallMoves([x,y]);
  50             case VariantRules.CARDINAL:
  51                 return this.getPotentialCardinalMoves([x,y]);
  52             default:
  53                 return super.getPotentialMovesFrom([x,y])
  54         }
  55     }
  56
  57     // Special pawn rules: promotions to captured friendly pieces,
  58     // optional on ranks 8-9 and mandatory on rank 10.
  59     getPotentialPawnMoves([x,y])
  60     {
  61         const color = this.turn;
  62         let moves = [];
  63         const V = VariantRules;
  64         const [sizeX,sizeY] = VariantRules.size;
  65         const shift = (color == "w" ? -1 : 1);
  66         const startRanks = (color == "w" ? [sizeX-2,sizeX-3] : [1,2]);
  67         const lastRanks = (color == "w" ? [0,1,2] : [sizeX-1,sizeX-2,sizeX-3]);
  68
  69         if (x+shift >= 0 && x+shift < sizeX && x+shift != lastRanks[0])
  70         {
  71             // Normal moves
  72             if (this.board[x+shift][y] == V.EMPTY)
  73             {
  74                 moves.push(this.getBasicMove([x,y], [x+shift,y]));
  75                 if (startRanks.includes(x) && this.board[x+2*shift][y] == V.EMPTY)
  76                 {
  77                     // Two squares jump
  78                     moves.push(this.getBasicMove([x,y], [x+2*shift,y]));
  79                     if (x == startRanks[0] && this.board[x+3*shift][y] == V.EMPTY)
  80                     {
  81                         // 3-squares jump
  82                         moves.push(this.getBasicMove([x,y], [x+3*shift,y]));
  83                     }
  84                 }
  85             }
  86             // Captures
  87             if (y>0 && this.canTake([x,y], [x+shift,y-1]) && this.board[x+shift][y-1] != V.EMPTY)
  88                 moves.push(this.getBasicMove([x,y], [x+shift,y-1]));
  89             if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1]) && this.board[x+shift][y+1] != V.EMPTY)
  90                 moves.push(this.getBasicMove([x,y], [x+shift,y+1]));
  91         }
  92
  93         if (lastRanks.includes(x+shift))
  94         {
  95             // Promotion
  96             let promotionPieces = [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN,V.MARSHALL,V.CARDINAL];
  97             promotionPieces.forEach(p => {
  98                 if (!this.captures[color][p] || this.captures[color][p]==0)
  99                     return;
 100                 // Normal move
 101                 if (this.board[x+shift][y] == V.EMPTY)
 102                     moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:p}));
 103                 // Captures
 104                 if (y>0 && this.canTake([x,y], [x+shift,y-1]) && this.board[x+shift][y-1] != V.EMPTY)
 105                     moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:color,p:p}));
 106                 if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1]) && this.board[x+shift][y+1] != V.EMPTY)
 107                     moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:color,p:p}));
 108             });
 109         }
 110
 111         // En passant
 112         const Lep = this.epSquares.length;
 113         const epSquare = Lep>0 ? this.epSquares[Lep-1] : undefined;
 114         if (!!epSquare)
 115         {
 116             for (let epsq of epSquare)
 117             {
 118                 // TODO: some redundant checks
 119                 if (epsq.x == x+shift && Math.abs(epsq.y - y) == 1)
 120                 {
 121                     let epStep = epsq.y - y;
 122                     var enpassantMove = this.getBasicMove([x,y], [x+shift,y+epStep]);
 123                     enpassantMove.vanish.push({
 124                         x: x,
 125                         y: y+epStep,
 126                         p: 'p',
 127                         c: this.getColor(x,y+epStep)
 128                     });
 129                     moves.push(enpassantMove);
 130                 }
 131             }
 132         }
 133
 134         return moves;
 135     }
 136
 137     // TODO: different castle?
 138
 139     getPotentialMarshallMoves(sq)
 140     {
 141         const V = VariantRules;
 142         return this.getSlideNJumpMoves(sq, V.steps[V.ROOK]).concat(
 143             this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep"));
 144     }
 145
 146     getPotentialCardinalMoves(sq)
 147     {
 148         const V = VariantRules;
 149         return this.getSlideNJumpMoves(sq, V.steps[V.BISHOP]).concat(
 150             this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep"));
 151     }
 152
 153     isAttacked(sq, colors)
 154     {
 155         return super.isAttacked(sq, colors)
 156             || this.isAttackedByMarshall(sq, colors)
 157             || this.isAttackedByCardinal(sq, colors);
 158     }
 159
 160     isAttackedByMarshall(sq, colors)
 161     {
 162         const V = VariantRules;
 163         return this.isAttackedBySlideNJump(sq, colors, V.MARSHALL, V.steps[V.ROOK])
 164             || this.isAttackedBySlideNJump(sq, colors, V.MARSHALL, V.steps[V.KNIGHT], "oneStep");
 165     }
 166
 167     isAttackedByCardinal(sq, colors)
 168     {
 169         const V = VariantRules;
 170         return this.isAttackedBySlideNJump(sq, colors, V.CARDINAL, V.steps[V.BISHOP])
 171             || this.isAttackedBySlideNJump(sq, colors, V.CARDINAL, V.steps[V.KNIGHT], "oneStep");
 172     }
 173
 174     updateVariables(move)
 175     {
 176         super.updateVariables(move);
 177         if (move.vanish.length==2 && move.appear.length==1
 178             && move.vanish[1].p != VariantRules.PAWN)
 179         {
 180             // Capture: update this.captures
 181             if (!this.captures[move.vanish[1].c][move.vanish[1].p])
 182                 this.captures[move.vanish[1].c][move.vanish[1].p] = 1;
 183             else
 184                 this.captures[move.vanish[1].c][move.vanish[1].p]++;
 185         }
 186     }
 187
 188     unupdateVariables(move)
 189     {
 190         super.unupdateVariables(move);
 191         if (move.vanish.length==2 && move.appear.length==1
 192             && move.vanish[1].p != VariantRules.PAWN)
 193         {
 194             this.captures[move.vanish[1].c][move.vanish[1].p] =
 195                 Math.max(0, this.captures[move.vanish[1].c][move.vanish[1].p]-1);
 196         }
 197     }
 198
 199     static get VALUES() {
 200         return Object.assign(
 201             ChessRules.VALUES,
 202             {'c': 5, 'm': 7} //experimental
 203         );
 204     }
 205
 206     static get SEARCH_DEPTH() { return 2; }
 207
 208     // TODO: this function could be generalized and shared better
 209     static GenRandInitFen()
 210     {
 211         let pieces = [new Array(10), new Array(10)];
 212         // Shuffle pieces on first and last rank
 213         for (let c = 0; c <= 1; c++)
 214         {
 215             let positions = _.range(10);
 216
 217             // Get random squares for bishops
 218             let randIndex = 2 * _.random(4);
 219             let bishop1Pos = positions[randIndex];
 220             // The second bishop must be on a square of different color
 221             let randIndex_tmp = 2 * _.random(4) + 1;
 222             let bishop2Pos = positions[randIndex_tmp];
 223             // Remove chosen squares
 224             positions.splice(Math.max(randIndex,randIndex_tmp), 1);
 225             positions.splice(Math.min(randIndex,randIndex_tmp), 1);
 226
 227             // Get random squares for knights
 228             randIndex = _.random(7);
 229             let knight1Pos = positions[randIndex];
 230             positions.splice(randIndex, 1);
 231             randIndex = _.random(6);
 232             let knight2Pos = positions[randIndex];
 233             positions.splice(randIndex, 1);
 234
 235             // Get random square for queen
 236             randIndex = _.random(5);
 237             let queenPos = positions[randIndex];
 238             positions.splice(randIndex, 1);
 239
 240             // ...random square for marshall
 241             randIndex = _.random(4);
 242             let marshallPos = positions[randIndex];
 243             positions.splice(randIndex, 1);
 244
 245             // ...random square for cardinal
 246             randIndex = _.random(3);
 247             let cardinalPos = positions[randIndex];
 248             positions.splice(randIndex, 1);
 249
 250             // Rooks and king positions are now fixed, because of the ordering rook-king-rook
 251             let rook1Pos = positions[0];
 252             let kingPos = positions[1];
 253             let rook2Pos = positions[2];
 254
 255             // Finally put the shuffled pieces in the board array
 256             pieces[c][rook1Pos] = 'r';
 257             pieces[c][knight1Pos] = 'n';
 258             pieces[c][bishop1Pos] = 'b';
 259             pieces[c][queenPos] = 'q';
 260             pieces[c][marshallPos] = 'm';
 261             pieces[c][cardinalPos] = 'c';
 262             pieces[c][kingPos] = 'k';
 263             pieces[c][bishop2Pos] = 'b';
 264             pieces[c][knight2Pos] = 'n';
 265             pieces[c][rook2Pos] = 'r';
 266         }
 267         let fen = pieces[0].join("") +
 268             "/pppppppppp/10/10/10/10/10/10/PPPPPPPPPP/" +
 269             pieces[1].join("").toUpperCase() +
 270             " 1111";
 271         return fen;
 272     }
 273 }