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
   7   static get HasFlags() {
   8     return false;
   9   }
  10
  11   static get HasEnpassant() {
  12     return false;
  13   }
  14
  15   static get Monochrome() {
  16     return true;
  17   }
  18
  19   static get PawnSpecs() {
  20     return Object.assign(
  21       {},
  22       ChessRules.PawnSpecs,
  23       { promotions: [V.QUEEN] }
  24     );
  25   }
  26
  27   static get PIECES() {
  28     return ChessRules.PIECES.concat(V.PROMOTED);
  29   }
  30
  31   static get PROMOTED() {
  32     return 'f';
  33   }
  34
  35   static GenRandInitFen(randomness) {
  36     if (randomness == 0)
  37       return "rnbqkbnr/8/pppppppp/8/8/PPPPPPPP/8/RNBKQBNR w 0";
  38
  39     let pieces = { w: new Array(8), b: new Array(8) };
  40     for (let c of ["w", "b"]) {
  41       if (c == 'b' && randomness == 1) {
  42         pieces['b'] = pieces['w'];
  43         break;
  44       }
  45
  46       // Get random squares for every piece, totally freely (no castling)
  47       let positions = shuffle(ArrayFun.range(8));
  48       const composition = ['b', 'b', 'r', 'r', 'n', 'n', 'k', 'q'];
  49       for (let i = 0; i < 8; i++) pieces[c][positions[i]] = composition[i];
  50     }
  51     return (
  52       pieces["b"].join("") +
  53       "/8/pppppppp/8/8/PPPPPPPP/8/" +
  54       pieces["w"].join("").toUpperCase() +
  55       " w 0"
  56     );
  57   }
  58
  59   getPpath(b) {
  60     return "Makruk/" + b;
  61   }
  62
  63   getPotentialMovesFrom([x, y]) {
  64     if (this.getPiece(x, y) == V.PROMOTED)
  65       return this.getPotentialQueenMoves([x, y]);
  66     return super.getPotentialMovesFrom([x, y]);
  67   }
  68
  69   getPotentialPawnMoves([x, y]) {
  70     const color = this.turn;
  71     const shiftX = V.PawnSpecs.directions[color];
  72     const sixthRank = (color == 'w' ? 2 : 5);
  73     const tr = (x + shiftX == sixthRank ? { p: V.PROMOTED, c: color } : null);
  74     let moves = [];
  75     if (this.board[x + shiftX][y] == V.EMPTY)
  76       // One square forward
  77       moves.push(this.getBasicMove([x, y], [x + shiftX, y], tr));
  78     // Captures
  79     for (let shiftY of [-1, 1]) {
  80       if (
  81         y + shiftY >= 0 && y + shiftY < 8 &&
  82         this.board[x + shiftX][y + shiftY] != V.EMPTY &&
  83         this.canTake([x, y], [x + shiftX, y + shiftY])
  84       ) {
  85         moves.push(this.getBasicMove([x, y], [x + shiftX, y + shiftY], tr));
  86       }
  87     }
  88     return moves;
  89   }
  90
  91   getPotentialBishopMoves(sq) {
  92     const forward = (this.turn == 'w' ? -1 : 1);
  93     return this.getSlideNJumpMoves(
  94       sq,
  95       V.steps[V.BISHOP].concat([ [forward, 0] ]),
  96       "oneStep"
  97     );
  98   }
  99
 100   getPotentialQueenMoves(sq) {
 101     return this.getSlideNJumpMoves(
 102       sq,
 103       V.steps[V.BISHOP],
 104       "oneStep"
 105     );
 106   }
 107
 108   isAttackedByBishop(sq, color) {
 109     const forward = (color == 'w' ? 1 : -1);
 110     return this.isAttackedBySlideNJump(
 111       sq,
 112       color,
 113       V.BISHOP,
 114       V.steps[V.BISHOP].concat([ [forward, 0] ]),
 115       "oneStep"
 116     );
 117   }
 118
 119   isAttackedByQueen(sq, color) {
 120     return this.isAttackedBySlideNJump(
 121       sq,
 122       color,
 123       V.QUEEN,
 124       V.steps[V.BISHOP],
 125       "oneStep"
 126     );
 127   }
 128
 129   static get VALUES() {
 130     return {
 131       p: 1,
 132       r: 5,
 133       n: 3,
 134       b: 3,
 135       q: 2,
 136       f: 2,
 137       k: 1000
 138     };
 139   }
 140
 141 };