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 Notoodark() {
  20     return true;
  21   }
  22
  23   static get PawnSpecs() {
  24     return Object.assign(
  25       {},
  26       ChessRules.PawnSpecs,
  27       { promotions: [V.QUEEN] }
  28     );
  29   }
  30
  31   static get PIECES() {
  32     return ChessRules.PIECES.concat(V.PROMOTED);
  33   }
  34
  35   static get PROMOTED() {
  36     return 'f';
  37   }
  38
  39   static GenRandInitFen(randomness) {
  40     if (randomness == 0)
  41       return "rnbqkbnr/8/pppppppp/8/8/PPPPPPPP/8/RNBKQBNR w 0";
  42
  43     let pieces = { w: new Array(8), b: new Array(8) };
  44     for (let c of ["w", "b"]) {
  45       if (c == 'b' && randomness == 1) {
  46         pieces['b'] = pieces['w'];
  47         break;
  48       }
  49
  50       // Get random squares for every piece, totally freely (no castling)
  51       let positions = shuffle(ArrayFun.range(8));
  52       const composition = ['b', 'b', 'r', 'r', 'n', 'n', 'k', 'q'];
  53       for (let i = 0; i < 8; i++) pieces[c][positions[i]] = composition[i];
  54     }
  55     return (
  56       pieces["b"].join("") +
  57       "/8/pppppppp/8/8/PPPPPPPP/8/" +
  58       pieces["w"].join("").toUpperCase() +
  59       " w 0"
  60     );
  61   }
  62
  63   getPpath(b) {
  64     return "Makruk/" + b;
  65   }
  66
  67   getPotentialMovesFrom([x, y]) {
  68     if (this.getPiece(x, y) == V.PROMOTED)
  69       return this.getPotentialQueenMoves([x, y]);
  70     return super.getPotentialMovesFrom([x, y]);
  71   }
  72
  73   getPotentialPawnMoves([x, y]) {
  74     const color = this.turn;
  75     const shiftX = V.PawnSpecs.directions[color];
  76     const sixthRank = (color == 'w' ? 2 : 5);
  77     const tr = (x + shiftX == sixthRank ? { p: V.PROMOTED, c: color } : null);
  78     let moves = [];
  79     if (this.board[x + shiftX][y] == V.EMPTY)
  80       // One square forward
  81       moves.push(this.getBasicMove([x, y], [x + shiftX, y], tr));
  82     // Captures
  83     for (let shiftY of [-1, 1]) {
  84       if (
  85         y + shiftY >= 0 && y + shiftY < 8 &&
  86         this.board[x + shiftX][y + shiftY] != V.EMPTY &&
  87         this.canTake([x, y], [x + shiftX, y + shiftY])
  88       ) {
  89         moves.push(this.getBasicMove([x, y], [x + shiftX, y + shiftY], tr));
  90       }
  91     }
  92     return moves;
  93   }
  94
  95   getPotentialBishopMoves(sq) {
  96     const forward = (this.turn == 'w' ? -1 : 1);
  97     return this.getSlideNJumpMoves(
  98       sq,
  99       V.steps[V.BISHOP].concat([ [forward, 0] ]),
 100       "oneStep"
 101     );
 102   }
 103
 104   getPotentialQueenMoves(sq) {
 105     return this.getSlideNJumpMoves(
 106       sq,
 107       V.steps[V.BISHOP],
 108       "oneStep"
 109     );
 110   }
 111
 112   isAttacked(sq, color) {
 113     return (
 114       super.isAttacked(sq, color) || this.isAttackedByPromoted(sq, color)
 115     );
 116   }
 117
 118   isAttackedByBishop(sq, color) {
 119     const forward = (color == 'w' ? 1 : -1);
 120     return this.isAttackedBySlideNJump(
 121       sq,
 122       color,
 123       V.BISHOP,
 124       V.steps[V.BISHOP].concat([ [forward, 0] ]),
 125       "oneStep"
 126     );
 127   }
 128
 129   isAttackedByQueen(sq, color) {
 130     return this.isAttackedBySlideNJump(
 131       sq,
 132       color,
 133       V.QUEEN,
 134       V.steps[V.BISHOP],
 135       "oneStep"
 136     );
 137   }
 138
 139   isAttackedByPromoted(sq, color) {
 140     return super.isAttackedBySlideNJump(
 141       sq,
 142       color,
 143       V.PROMOTED,
 144       V.steps[V.BISHOP],
 145       "oneStep"
 146     );
 147   }
 148
 149   static get VALUES() {
 150     return {
 151       p: 1,
 152       r: 5,
 153       n: 3,
 154       b: 3,
 155       q: 2,
 156       f: 2,
 157       k: 1000
 158     };
 159   }
 160
 161 };