client/src/variants/Capablanca.js

   1 import { ChessRules } from "@/base_rules";
   2 import { ArrayFun } from "@/utils/array";
   3 import { randInt } from "@/utils/alea";
   4
   5 export class CapablancaRules extends ChessRules {
   6
   7   static get PawnSpecs() {
   8     return Object.assign(
   9       {},
  10       ChessRules.PawnSpecs,
  11       {
  12         promotions:
  13           ChessRules.PawnSpecs.promotions
  14           .concat([V.EMPRESS, V.PRINCESS])
  15       }
  16     );
  17   }
  18
  19   getPpath(b) {
  20     return ([V.EMPRESS, V.PRINCESS].includes(b[1]) ? "Capablanca/" : "") + b;
  21   }
  22
  23   static get size() {
  24     return { x: 8, y: 10 };
  25   }
  26
  27   // Rook + knight:
  28   static get EMPRESS() {
  29     return "e";
  30   }
  31
  32   // Bishop + knight
  33   static get PRINCESS() {
  34     return "s";
  35   }
  36
  37   static get PIECES() {
  38     return ChessRules.PIECES.concat([V.EMPRESS, V.PRINCESS]);
  39   }
  40
  41   getPotentialMovesFrom([x, y]) {
  42     switch (this.getPiece(x, y)) {
  43       case V.EMPRESS:
  44         return this.getPotentialEmpressMoves([x, y]);
  45       case V.PRINCESS:
  46         return this.getPotentialPrincessMoves([x, y]);
  47       default:
  48         return super.getPotentialMovesFrom([x, y]);
  49     }
  50   }
  51
  52   getPotentialEmpressMoves(sq) {
  53     return this.getSlideNJumpMoves(sq, V.steps[V.ROOK]).concat(
  54       this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], 1)
  55     );
  56   }
  57
  58   getPotentialPrincessMoves(sq) {
  59     return this.getSlideNJumpMoves(sq, V.steps[V.BISHOP]).concat(
  60       this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], 1)
  61     );
  62   }
  63
  64   isAttacked(sq, color) {
  65     return (
  66       super.isAttacked(sq, color) ||
  67       this.isAttackedByEmpress(sq, color) ||
  68       this.isAttackedByPrincess(sq, color)
  69     );
  70   }
  71
  72   isAttackedByEmpress(sq, color) {
  73     return (
  74       this.isAttackedBySlideNJump(sq, color, V.EMPRESS, V.steps[V.ROOK]) ||
  75       this.isAttackedBySlideNJump(sq, color, V.EMPRESS, V.steps[V.KNIGHT], 1)
  76     );
  77   }
  78
  79   isAttackedByPrincess(sq, color) {
  80     return (
  81       this.isAttackedBySlideNJump(sq, color, V.PRINCESS, V.steps[V.BISHOP]) ||
  82       this.isAttackedBySlideNJump(sq, color, V.PRINCESS, V.steps[V.KNIGHT], 1)
  83     );
  84   }
  85
  86   static get VALUES() {
  87     return Object.assign(
  88       { s: 5, e: 7 },
  89       ChessRules.VALUES
  90     );
  91   }
  92
  93   static get SEARCH_DEPTH() {
  94     return 2;
  95   }
  96
  97   static GenRandInitFen(options) {
  98     if (options.randomness == 0) {
  99       return (
 100         "rnsbqkbenr/pppppppppp/91/91/91/91/PPPPPPPPPP/RNSBQKBENR w 0 ajaj -"
 101       );
 102     }
 103
 104     let pieces = { w: new Array(10), b: new Array(10) };
 105     let flags = "";
 106     for (let c of ["w", "b"]) {
 107       if (c == 'b' && options.randomness == 1) {
 108         pieces['b'] = pieces['w'];
 109         flags += flags;
 110         break;
 111       }
 112
 113       let positions = ArrayFun.range(10);
 114
 115       // Get random squares for bishops
 116       let randIndex = 2 * randInt(5);
 117       const bishop1Pos = positions[randIndex];
 118       // The second bishop must be on a square of different color
 119       let randIndex_tmp = 2 * randInt(5) + 1;
 120       const bishop2Pos = positions[randIndex_tmp];
 121       // Remove chosen squares
 122       positions.splice(Math.max(randIndex, randIndex_tmp), 1);
 123       positions.splice(Math.min(randIndex, randIndex_tmp), 1);
 124
 125       // Get random square for empress
 126       randIndex = randInt(8);
 127       const empressPos = positions[randIndex];
 128       positions.splice(randIndex, 1);
 129
 130       // Get random square for princess
 131       randIndex = randInt(7);
 132       const princessPos = positions[randIndex];
 133       positions.splice(randIndex, 1);
 134
 135       // Get random squares for knights
 136       randIndex = randInt(6);
 137       const knight1Pos = positions[randIndex];
 138       positions.splice(randIndex, 1);
 139       randIndex = randInt(5);
 140       const knight2Pos = positions[randIndex];
 141       positions.splice(randIndex, 1);
 142
 143       // Get random square for queen
 144       randIndex = randInt(4);
 145       const queenPos = positions[randIndex];
 146       positions.splice(randIndex, 1);
 147
 148       // Now rooks + king positions are fixed:
 149       const rook1Pos = positions[0];
 150       const kingPos = positions[1];
 151       const rook2Pos = positions[2];
 152
 153       // Finally put the shuffled pieces in the board array
 154       pieces[c][rook1Pos] = "r";
 155       pieces[c][knight1Pos] = "n";
 156       pieces[c][bishop1Pos] = "b";
 157       pieces[c][queenPos] = "q";
 158       pieces[c][empressPos] = "e";
 159       pieces[c][princessPos] = "s";
 160       pieces[c][kingPos] = "k";
 161       pieces[c][bishop2Pos] = "b";
 162       pieces[c][knight2Pos] = "n";
 163       pieces[c][rook2Pos] = "r";
 164       flags += V.CoordToColumn(rook1Pos) + V.CoordToColumn(rook2Pos);
 165     }
 166     return (
 167       pieces["b"].join("") + "/pppppppppp/91/91/91/91/PPPPPPPPPP/" +
 168       pieces["w"].join("").toUpperCase() + " w 0 " + flags + " - -"
 169     );
 170   }
 171
 172 };