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 Monochrome() {
  15     return true;
  16   }
  17
  18   static get PawnSpecs() {
  19     return Object.assign(
  20       {},
  21       ChessRules.PawnSpecs,
  22       { promotions: [V.QUEEN] }
  23     );
  24   }
  25
  26   static get PIECES() {
  27     return ChessRules.PIECES.concat(V.PROMOTED);
  28   }
  29
  30   static get PROMOTED() {
  31     return 'f';
  32   }
  33
  34   static GenRandInitFen(randomness) {
  35     if (randomness == 0)
  36       return "rnbqkbnr/8/pppppppp/8/8/PPPPPPPP/8/RNBKQBNR w 0";
  37
  38     let pieces = { w: new Array(8), b: new Array(8) };
  39     for (let c of ["w", "b"]) {
  40       if (c == 'b' && randomness == 1) {
  41         pieces['b'] = pieces['w'];
  42         break;
  43       }
  44
  45       // Get random squares for every piece, totally freely (no castling)
  46       let positions = shuffle(ArrayFun.range(8));
  47       const composition = ['b', 'b', 'r', 'r', 'n', 'n', 'k', 'q'];
  48       for (let i = 0; i < 8; i++) pieces[c][positions[i]] = composition[i];
  49     }
  50     return (
  51       pieces["b"].join("") +
  52       "/8/pppppppp/8/8/PPPPPPPP/8/" +
  53       pieces["w"].join("").toUpperCase() +
  54       " w 0"
  55     );
  56   }
  57
  58   getPpath(b) {
  59     return "Makruk/" + b;
  60   }
  61
  62   getPotentialMovesFrom([x, y]) {
  63     if (this.getPiece(x, y) == V.PROMOTED)
  64       return this.getPotentialQueenMoves([x, y]);
  65     return super.getPotentialMovesFrom([x, y]);
  66   }
  67
  68   getPotentialPawnMoves([x, y]) {
  69     const color = this.turn;
  70     const shiftX = V.PawnSpecs.directions[color];
  71     const sixthRank = (color == 'w' ? 2 : 5);
  72     const tr = (x + shiftX == sixthRank ? { p: V.PROMOTED, c: color } : null);
  73     let moves = [];
  74     if (this.board[x + shiftX][y] == V.EMPTY)
  75       // One square forward
  76       moves.push(this.getBasicMove([x, y], [x + shiftX, y], tr));
  77     // Captures
  78     for (let shiftY of [-1, 1]) {
  79       if (
  80         y + shiftY >= 0 && y + shiftY < 8 &&
  81         this.board[x + shiftX][y + shiftY] != V.EMPTY &&
  82         this.canTake([x, y], [x + shiftX, y + shiftY])
  83       ) {
  84         moves.push(this.getBasicMove([x, y], [x + shiftX, y + shiftY], tr));
  85       }
  86     }
  87     return moves;
  88   }
  89
  90   getPotentialBishopMoves(sq) {
  91     const forward = (this.turn == 'w' ? -1 : 1);
  92     return this.getSlideNJumpMoves(
  93       sq,
  94       V.steps[V.BISHOP].concat([ [forward, 0] ]),
  95       "oneStep"
  96     );
  97   }
  98
  99   getPotentialQueenMoves(sq) {
 100     return this.getSlideNJumpMoves(
 101       sq,
 102       V.steps[V.BISHOP],
 103       "oneStep"
 104     );
 105   }
 106
 107   isAttackedByBishop(sq, color) {
 108     const forward = (color == 'w' ? 1 : -1);
 109     return this.isAttackedBySlideNJump(
 110       sq,
 111       color,
 112       V.BISHOP,
 113       V.steps[V.BISHOP].concat([ [forward, 0] ]),
 114       "oneStep"
 115     );
 116   }
 117
 118   isAttackedByQueen(sq, color) {
 119     return this.isAttackedBySlideNJump(
 120       sq,
 121       color,
 122       V.QUEEN,
 123       V.steps[V.BISHOP],
 124       "oneStep"
 125     );
 126   }
 127
 128   static get VALUES() {
 129     return {
 130       p: 1,
 131       r: 5,
 132       n: 3,
 133       b: 3,
 134       q: 2,
 135       f: 2,
 136       k: 1000
 137     };
 138   }
 139 };