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