client/src/variants/Makruk.js

   1 import { ChessRules, Move, PiPo } from "@/base_rules";
   2 import { ArrayFun } from "@/utils/array";
   3 import { randInt, shuffle } from "@/utils/alea";
   4
   5 export class MakrukRules extends ChessRules {
   6   static get HasFlags() {
   7     return false;
   8   }
   9
  10   static get HasEnpassant() {
  11     return false;
  12   }
  13
  14   static get PawnSpecs() {
  15     return Object.assign(
  16       {},
  17       ChessRules.PawnSpecs,
  18       {
  19         twoSquares: false,
  20         promotions: [V.QUEEN]
  21       }
  22     );
  23   }
  24
  25   static get PIECES() {
  26     return ChessRules.PIECES.concat(V.PROMOTED);
  27   }
  28
  29   static get PROMOTED() {
  30     return 'f';
  31   }
  32
  33   static GenRandInitFen(randomness) {
  34     if (randomness == 0)
  35       return "rnbqkbnr/8/pppppppp/8/8/PPPPPPPP/8/RNBKQBNR w 0";
  36
  37     let pieces = { w: new Array(8), b: new Array(8) };
  38     for (let c of ["w", "b"]) {
  39       if (c == 'b' && randomness == 1) {
  40         pieces['b'] = pieces['w'];
  41         break;
  42       }
  43
  44       // Get random squares for every piece, totally freely (no castling)
  45       let positions = shuffle(ArrayFun.range(8));
  46       const composition = ['b', 'b', 'r', 'r', 'n', 'n', 'k', 'q'];
  47       for (let i = 0; i < 8; i++) pieces[c][positions[i]] = composition[i];
  48     }
  49     return (
  50       pieces["b"].join("") +
  51       "/8/pppppppp/8/8/PPPPPPPP/8/" +
  52       pieces["w"].join("").toUpperCase() +
  53       " w 0"
  54     );
  55   }
  56
  57   getPpath(b) {
  58     return "Makruk/" + b;
  59   }
  60
  61   getPotentialMovesFrom([x, y]) {
  62     if (this.getPiece(x, y) == V.PROMOTED)
  63       return this.getPotentialQueenMoves([x, y]);
  64     return super.getPotentialMovesFrom([x, y]);
  65   }
  66
  67   getPotentialPawnMoves([x, y]) {
  68     const color = this.turn;
  69     const shiftX = V.PawnSpecs.directions[color];
  70     const sixthRank = (color == 'w' ? 2 : 5);
  71     const tr = (x + shiftX == sixthRank ? { p: V.PROMOTED, c: color } : null);
  72     let moves = [];
  73     if (this.board[x + shiftX][y] == V.EMPTY)
  74       // One square forward
  75       moves.push(this.getBasicMove([x, y], [x + shiftX, y], tr));
  76     // Captures
  77     for (let shiftY of [-1, 1]) {
  78       if (
  79         y + shiftY >= 0 && y + shiftY < 8 &&
  80         this.board[x + shiftX][y + shiftY] != V.EMPTY &&
  81         this.canTake([x, y], [x + shiftX, y + shiftY])
  82       ) {
  83         moves.push(this.getBasicMove([x, y], [x + shiftX, y + shiftY], tr));
  84       }
  85     }
  86     return moves;
  87   }
  88
  89   getPotentialBishopMoves(sq) {
  90     const forward = (this.turn == 'w' ? -1 : 1);
  91     return this.getSlideNJumpMoves(
  92       sq,
  93       V.steps[V.BISHOP].concat([ [forward, 0] ]),
  94       "oneStep"
  95     );
  96   }
  97
  98   getPotentialQueenMoves(sq) {
  99     return this.getSlideNJumpMoves(
 100       sq,
 101       V.steps[V.BISHOP],
 102       "oneStep"
 103     );
 104   }
 105
 106   isAttackedByBishop(sq, color) {
 107     const forward = (color == 'w' ? 1 : -1);
 108     return this.isAttackedBySlideNJump(
 109       sq,
 110       color,
 111       V.BISHOP,
 112       V.steps[V.BISHOP].concat([ [forward, 0] ]),
 113       "oneStep"
 114     );
 115   }
 116
 117   isAttackedByQueen(sq, color) {
 118     return this.isAttackedBySlideNJump(
 119       sq,
 120       color,
 121       V.QUEEN,
 122       V.steps[V.BISHOP],
 123       "oneStep"
 124     );
 125   }
 126
 127   static get VALUES() {
 128     return {
 129       p: 1,
 130       r: 5,
 131       n: 3,
 132       b: 3,
 133       q: 2,
 134       f: 2,
 135       k: 1000
 136     };
 137   }
 138 };