client/src/variants/Knightmate.js

   1 import { ChessRules } from "@/base_rules";
   2 import { ArrayFun } from "@/utils/array";
   3 import { randInt } from "@/utils/alea";
   4
   5 export const VariantRules = class KnightmateRules extends ChessRules {
   6   static get COMMONER() {
   7     return "c";
   8   }
   9
  10   static get PIECES() {
  11     return ChessRules.PIECES.concat([V.COMMONER]);
  12   }
  13
  14   getPpath(b) {
  15     return ([V.KING, V.COMMONER].includes(b[1]) ? "Knightmate/" : "") + b;
  16   }
  17
  18   static GenRandInitFen() {
  19     let pieces = { w: new Array(8), b: new Array(8) };
  20     // Shuffle pieces on first and last rank
  21     for (let c of ["w", "b"]) {
  22       let positions = ArrayFun.range(8);
  23
  24       // Get random squares for bishops
  25       let randIndex = 2 * randInt(4);
  26       const bishop1Pos = positions[randIndex];
  27       let randIndex_tmp = 2 * randInt(4) + 1;
  28       const bishop2Pos = positions[randIndex_tmp];
  29       positions.splice(Math.max(randIndex, randIndex_tmp), 1);
  30       positions.splice(Math.min(randIndex, randIndex_tmp), 1);
  31
  32       // Get random squares for commoners
  33       randIndex = randInt(6);
  34       const commoner1Pos = positions[randIndex];
  35       positions.splice(randIndex, 1);
  36       randIndex = randInt(5);
  37       const commoner2Pos = positions[randIndex];
  38       positions.splice(randIndex, 1);
  39
  40       // Get random square for queen
  41       randIndex = randInt(4);
  42       const queenPos = positions[randIndex];
  43       positions.splice(randIndex, 1);
  44
  45       // Rooks and king positions are now fixed,
  46       // because of the ordering rook-king-rook
  47       const rook1Pos = positions[0];
  48       const kingPos = positions[1];
  49       const rook2Pos = positions[2];
  50
  51       // Finally put the shuffled pieces in the board array
  52       pieces[c][rook1Pos] = "r";
  53       pieces[c][commoner1Pos] = "c";
  54       pieces[c][bishop1Pos] = "b";
  55       pieces[c][queenPos] = "q";
  56       pieces[c][kingPos] = "k";
  57       pieces[c][bishop2Pos] = "b";
  58       pieces[c][commoner2Pos] = "c";
  59       pieces[c][rook2Pos] = "r";
  60     }
  61     // Add turn + flags + enpassant
  62     return (
  63       pieces["b"].join("") +
  64       "/pppppppp/8/8/8/8/PPPPPPPP/" +
  65       pieces["w"].join("").toUpperCase() +
  66       " w 0 1111 -"
  67     );
  68   }
  69
  70   getPotentialMovesFrom([x, y]) {
  71     switch (this.getPiece(x, y)) {
  72       case V.COMMONER:
  73         return this.getPotentialCommonerMoves([x, y]);
  74       default:
  75         return super.getPotentialMovesFrom([x, y]);
  76     }
  77   }
  78
  79   getPotentialCommonerMoves(sq) {
  80     return this.getSlideNJumpMoves(
  81       sq,
  82       V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
  83       "oneStep"
  84     );
  85   }
  86
  87   getPotentialKingMoves(sq) {
  88     return super.getPotentialKnightMoves(sq).concat(super.getCastleMoves(sq));
  89   }
  90
  91   isAttacked(sq, colors) {
  92     return (
  93       this.isAttackedByCommoner(sq, colors) ||
  94       this.isAttackedByPawn(sq, colors) ||
  95       this.isAttackedByRook(sq, colors) ||
  96       this.isAttackedByBishop(sq, colors) ||
  97       this.isAttackedByQueen(sq, colors) ||
  98       this.isAttackedByKing(sq, colors)
  99     );
 100   }
 101
 102   isAttackedByKing(sq, colors) {
 103     return this.isAttackedBySlideNJump(
 104       sq,
 105       colors,
 106       V.KING,
 107       V.steps[V.KNIGHT],
 108       "oneStep"
 109     );
 110   }
 111
 112   isAttackedByCommoner(sq, colors) {
 113     return this.isAttackedBySlideNJump(
 114       sq,
 115       colors,
 116       V.COMMONER,
 117       V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
 118       "oneStep"
 119     );
 120   }
 121
 122   static get VALUES() {
 123     return {
 124       p: 1,
 125       r: 5,
 126       c: 5, //the commoner is valuable
 127       b: 3,
 128       q: 9,
 129       k: 1000
 130     };
 131   }
 132 };