client/src/variants/Diamond.js

   1 import { ChessRules } from "@/base_rules";
   2 import { ArrayFun } from "@/utils/array";
   3 import { shuffle } from "@/utils/alea";
   4
   5 export class DiamondRules extends ChessRules {
   6
   7   static get HasFlags() {
   8     return false;
   9   }
  10
  11   static get HasEnpassant() {
  12     return false;
  13   }
  14
  15   static GenRandInitFen(randomness) {
  16     if (randomness == 0)
  17       return "krbp4/rqnp4/nbpp4/pppp4/4PPPP/4PPBN/4PNQR/4PBRK w 0";
  18     let pieces = { w: new Array(8), b: new Array(8) };
  19     for (let c of ["w", "b"]) {
  20       if (c == 'b' && randomness == 1) {
  21         pieces['b'] = pieces['w'];
  22         break;
  23       }
  24       // Get random squares for every piece, totally freely
  25       let positions = shuffle(ArrayFun.range(8));
  26       const composition = ['b', 'b', 'r', 'r', 'n', 'n', 'k', 'q'];
  27       const rem2 = positions[0] % 2;
  28       if (rem2 == positions[1] % 2) {
  29         // Fix bishops (on different colors)
  30         for (let i=2; i<8; i++) {
  31           if (positions[i] % 2 != rem2)
  32             [positions[1], positions[i]] = [positions[i], positions[1]];
  33         }
  34       }
  35       for (let i = 0; i < 8; i++) pieces[c][positions[i]] = composition[i];
  36     }
  37     return (
  38       pieces["b"].slice(0, 3).join("") + "p4/" +
  39       pieces["b"].slice(3, 6).join("") + "p4/" +
  40       pieces["b"].slice(6, 8).join("") + "pp4/" +
  41       "pppp4/4PPPP/" +
  42       "4PP" + pieces["w"].slice(6, 8).reverse().join("").toUpperCase() + "/" +
  43       "4P" + pieces["w"].slice(3, 6).reverse().join("").toUpperCase() + "/" +
  44       "4P" + pieces["w"].slice(0, 3).reverse().join("").toUpperCase() +
  45       " w 0"
  46     );
  47   }
  48
  49   // Special pawns movements
  50   getPotentialPawnMoves([x, y]) {
  51     const color = this.turn;
  52     let moves = [];
  53     const [sizeX, sizeY] = [V.size.x, V.size.y];
  54     const shift = (color == "w" ? -1 : 1);
  55     const lastRank = (color == "w" ? 0 : 7);
  56
  57     // One square forward (diagonally along h1-a8)
  58     if (this.board[x + shift][y + shift] == V.EMPTY) {
  59       const finalPieces =
  60         [x + shift, y + shift].includes(lastRank)
  61           ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN]
  62           : [V.PAWN];
  63       for (let piece of finalPieces) {
  64         moves.push(
  65           this.getBasicMove(
  66             [x, y], [x + shift, y + shift], { c: color, p: piece })
  67         );
  68       }
  69     }
  70     // Capture
  71     for (let pShift of [[0, shift], [shift, 0]]) {
  72       if (
  73         this.board[x + pShift[0]][y + pShift[1]] != V.EMPTY &&
  74         this.canTake([x, y], [x + pShift[0], y + pShift[1]])
  75       ) {
  76         const finalPieces =
  77           [x + pShift[0], y + pShift[1]].includes(lastRank)
  78             ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN]
  79             : [V.PAWN];
  80         for (let piece of finalPieces) {
  81           moves.push(
  82             this.getBasicMove(
  83               [x, y],
  84               [x + pShift[0], y + pShift[1]],
  85               {
  86                 c: color,
  87                 p: piece
  88               }
  89             )
  90           );
  91         }
  92       }
  93     }
  94
  95     return moves;
  96   }
  97
  98   isAttackedByPawn([x, y], color) {
  99     let pawnShift = (color == "w" ? 1 : -1);
 100     return (
 101       (
 102         x + pawnShift >= 0 && x + pawnShift < V.size.x &&
 103         this.getPiece(x + pawnShift, y) == V.PAWN &&
 104         this.getColor(x + pawnShift, y) == color
 105       )
 106       ||
 107       (
 108         y + pawnShift >= 0 && y + pawnShift < V.size.y &&
 109         this.getPiece(x, y + pawnShift) == V.PAWN &&
 110         this.getColor(x, y + pawnShift) == color
 111       )
 112     );
 113   }
 114
 115   static get SEARCH_DEPTH() {
 116     return 2;
 117   }
 118
 119   getNotation(move) {
 120     const piece = this.getPiece(move.start.x, move.start.y);
 121     if (piece == V.PAWN) {
 122       // Pawn move
 123       const finalSquare = V.CoordsToSquare(move.end);
 124       let notation = "";
 125       if (move.vanish.length == 2)
 126         // Capture
 127         notation = "Px" + finalSquare;
 128       else {
 129         // No capture: indicate the initial square for potential ambiguity
 130         const startSquare = V.CoordsToSquare(move.start);
 131         notation = startSquare + finalSquare;
 132       }
 133       if (move.appear[0].p != V.PAWN)
 134         // Promotion
 135         notation += "=" + move.appear[0].p.toUpperCase();
 136       return notation;
 137     }
 138     return super.getNotation(move); //all other pieces are orthodox
 139   }
 140
 141 };