variants/Alice/class.js

   1 import ChessRules from "/base_rules.js";
   2 import {ArrayFun} from "/utils/array.js";
   3
   4 export default class AliceRules extends ChessRules {
   5
   6   static get Options() {
   7     return {
   8       select: C.Options.select,
   9       input: C.Options.input,
  10       styles: [
  11         "balance",
  12         "capture",
  13         "cylinder",
  14         "dark",
  15         "doublemove",
  16         "progressive",
  17         "zen"
  18       ]
  19     };
  20   }
  21
  22   // To the other side of the mirror and back...
  23   static get ALICE_PIECES() {
  24     return {
  25       s: "p",
  26       u: "r",
  27       o: "n",
  28       c: "b",
  29       t: "q",
  30       l: "k"
  31     };
  32   }
  33   static get ALICE_CODES() {
  34     return {
  35       p: "s",
  36       r: "u",
  37       n: "o",
  38       b: "c",
  39       q: "t",
  40       k: "l"
  41     };
  42   }
  43
  44   isKing(x, y, p) {
  45     if (!p)
  46       p = this.getPiece(x, y);
  47     return ['k', 'l'].includes(p);
  48   }
  49
  50   pieces(color, x, y) {
  51     let alices = {
  52       's': {"class": "alice-pawn", moveas: 'p'},
  53       'u': {"class": "alice-rook", moveas: 'r'},
  54       'o': {"class": "alice-knight", moveas: 'n'},
  55       'c': {"class": "alice-bishop", moveas: 'b'},
  56       't': {"class": "alice-queen", moveas: 'q'},
  57       'l': {"class": "alice-king", moveas: 'k'}
  58     };
  59     return Object.assign(alices, super.pieces(color, x, y));
  60   }
  61
  62   fromSameWorld(p1, p2) {
  63     return (
  64       (V.ALICE_PIECES[p1] && V.ALICE_PIECES[p2]) ||
  65       (V.ALICE_CODES[p1] && V.ALICE_CODES[p2])
  66     );
  67   }
  68
  69   // Step of p over i,j ?
  70   canStepOver(i, j, p) {
  71     return (
  72       this.board[i][j] == "" || !this.fromSameWorld(this.getPiece(i, j), p));
  73   }
  74
  75   getPotentialMovesFrom([x, y]) {
  76     return super.getPotentialMovesFrom([x, y]).filter(m => {
  77       // Remove moves landing on occupied square on other board
  78       return (
  79         this.board[m.end.x][m.end.y] == "" ||
  80         this.fromSameWorld(m.vanish[0].p, m.vanish[1].p)
  81       );
  82     }).map(m => {
  83       // Apply Alice rule: go to the other side of the mirror
  84       if (Object.keys(V.ALICE_CODES).includes(m.vanish[0].p))
  85         // Board 1
  86         m.appear.forEach(a => a.p = V.ALICE_CODES[a.p])
  87       else
  88         // Board 2
  89         m.appear.forEach(a => a.p = V.ALICE_PIECES[a.p])
  90       return m;
  91     });
  92   }
  93
  94   // helper for filterValid
  95   toggleWorld(x, y) {
  96     const piece = this.getPiece(x, y);
  97     if (V.ALICE_PIECES[piece])
  98       // From the other side of the mirror
  99       this.board[x][y] = this.getColor(x, y) + V.ALICE_PIECES[piece];
 100     else
 101       // From the other other side :)
 102       this.board[x][y] = this.getColor(x, y) + V.ALICE_CODES[piece];
 103   }
 104
 105   filterValid(moves) {
 106     const color = this.turn;
 107     const oppCol = C.GetOppTurn(color);
 108     const kingPos = this.searchKingPos(color)[0];
 109     const kingPiece = this.getPiece(kingPos[0], kingPos[1]);
 110     return super.filterValid(moves).filter(m => {
 111       // A move must also be legal on the board it is played:
 112       // Shortcut if the moving piece and king are on different sides
 113       if (
 114         !this.isKing(0, 0, m.vanish[0].p) &&
 115         !this.fromSameWorld(kingPiece, m.vanish[0].p)
 116       ) {
 117         return true;
 118       }
 119       this.playOnBoard(m);
 120       m.appear.forEach(a => this.toggleWorld(a.x, a.y));
 121       const kingAppear = m.appear.find(a => this.isKing(0, 0, a.p));
 122       const target = [kingAppear ? [kingAppear.x, kingAppear.y] : kingPos];
 123       const res = this.underCheck(target, oppCol);
 124       m.appear.forEach(a => this.toggleWorld(a.x, a.y));
 125       this.undoOnBoard(m);
 126       return !res;
 127     });
 128   }
 129
 130 };