client/src/variants/Antiking.js

   1 import { ChessRules } from "@/base_rules";
   2 import { ArrayFun } from "@/utils/array";
   3 import { randInt } from "@/utils/alea";
   4
   5 export const VariantRules = class AntikingRules extends ChessRules {
   6   static get ANTIKING() {
   7     return "a";
   8   }
   9
  10   static get PIECES() {
  11     return ChessRules.PIECES.concat([V.ANTIKING]);
  12   }
  13
  14   getPpath(b) {
  15     return b[1] == "a" ? "Antiking/" + b : b;
  16   }
  17
  18   setOtherVariables(fen) {
  19     super.setOtherVariables(fen);
  20     this.antikingPos = { w: [-1, -1], b: [-1, -1] };
  21     const rows = V.ParseFen(fen).position.split("/");
  22     for (let i = 0; i < rows.length; i++) {
  23       let k = 0;
  24       for (let j = 0; j < rows[i].length; j++) {
  25         switch (rows[i].charAt(j)) {
  26           case "a":
  27             this.antikingPos["b"] = [i, k];
  28             break;
  29           case "A":
  30             this.antikingPos["w"] = [i, k];
  31             break;
  32           default: {
  33             const num = parseInt(rows[i].charAt(j));
  34             if (!isNaN(num)) k += num - 1;
  35           }
  36         }
  37         k++;
  38       }
  39     }
  40   }
  41
  42   canTake([x1, y1], [x2, y2]) {
  43     const piece1 = this.getPiece(x1, y1);
  44     const piece2 = this.getPiece(x2, y2);
  45     const color1 = this.getColor(x1, y1);
  46     const color2 = this.getColor(x2, y2);
  47     return (
  48       piece2 != "a" &&
  49       ((piece1 != "a" && color1 != color2) ||
  50         (piece1 == "a" && color1 == color2))
  51     );
  52   }
  53
  54   getPotentialMovesFrom([x, y]) {
  55     switch (this.getPiece(x, y)) {
  56       case V.ANTIKING:
  57         return this.getPotentialAntikingMoves([x, y]);
  58       default:
  59         return super.getPotentialMovesFrom([x, y]);
  60     }
  61   }
  62
  63   getPotentialAntikingMoves(sq) {
  64     return this.getSlideNJumpMoves(
  65       sq,
  66       V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
  67       "oneStep"
  68     );
  69   }
  70
  71   isAttacked(sq, colors) {
  72     return (
  73       super.isAttacked(sq, colors) || this.isAttackedByAntiking(sq, colors)
  74     );
  75   }
  76
  77   isAttackedByKing([x, y], colors) {
  78     if (this.getPiece(x, y) == V.ANTIKING) return false; //antiking is not attacked by king
  79     return this.isAttackedBySlideNJump(
  80       [x, y],
  81       colors,
  82       V.KING,
  83       V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
  84       "oneStep"
  85     );
  86   }
  87
  88   isAttackedByAntiking([x, y], colors) {
  89     if ([V.KING, V.ANTIKING].includes(this.getPiece(x, y))) return false; //(anti)king is not attacked by antiking
  90     return this.isAttackedBySlideNJump(
  91       [x, y],
  92       colors,
  93       V.ANTIKING,
  94       V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
  95       "oneStep"
  96     );
  97   }
  98
  99   underCheck(color) {
 100     const oppCol = V.GetOppCol(color);
 101     let res =
 102       this.isAttacked(this.kingPos[color], [oppCol]) ||
 103       !this.isAttacked(this.antikingPos[color], [oppCol]);
 104     return res;
 105   }
 106
 107   getCheckSquares(color) {
 108     let res = super.getCheckSquares(color);
 109     if (!this.isAttacked(this.antikingPos[color], [V.GetOppCol(color)]))
 110       res.push(JSON.parse(JSON.stringify(this.antikingPos[color])));
 111     return res;
 112   }
 113
 114   postPlay(move) {
 115     super.postPlay(move);
 116     const piece = move.vanish[0].p;
 117     const c = move.vanish[0].c;
 118     // Update antiking position
 119     if (piece == V.ANTIKING) {
 120       this.antikingPos[c][0] = move.appear[0].x;
 121       this.antikingPos[c][1] = move.appear[0].y;
 122     }
 123   }
 124
 125   postUndo(move) {
 126     super.postUndo(move);
 127     const c = move.vanish[0].c;
 128     if (move.vanish[0].p == V.ANTIKING)
 129       this.antikingPos[c] = [move.start.x, move.start.y];
 130   }
 131
 132   getCurrentScore() {
 133     if (this.atLeastOneMove())
 134       return "*";
 135
 136     const color = this.turn;
 137     const oppCol = V.GetOppCol(color);
 138     if (
 139       !this.isAttacked(this.kingPos[color], [oppCol]) &&
 140       this.isAttacked(this.antikingPos[color], [oppCol])
 141     ) {
 142       return "1/2";
 143     }
 144     return color == "w" ? "0-1" : "1-0";
 145   }
 146
 147   static get VALUES() {
 148     return Object.assign(
 149       { a: 1000 },
 150       ChessRules.VALUES
 151     );
 152   }
 153
 154   static GenRandInitFen(randomness) {
 155     if (randomness == 0)
 156       return "rnbqkbnr/pppppppp/3A4/8/8/3a4/PPPPPPPP/RNBQKBNR w 0 ahah -";
 157
 158     let pieces = { w: new Array(8), b: new Array(8) };
 159     let flags = "";
 160     let antikingPos = { w: -1, b: -1 };
 161     for (let c of ["w", "b"]) {
 162       if (c == 'b' && randomness == 1) {
 163         pieces['b'] = pieces['w'];
 164         antikingPos['b'] = antikingPos['w'];
 165         flags += flags;
 166         break;
 167       }
 168
 169       let positions = ArrayFun.range(8);
 170
 171       // Get random squares for bishops, but avoid corners; because,
 172       // if an antiking blocks a cornered bishop, it can never be checkmated
 173       let randIndex = 2 * randInt(1, 4);
 174       const bishop1Pos = positions[randIndex];
 175       let randIndex_tmp = 2 * randInt(3) + 1;
 176       const bishop2Pos = positions[randIndex_tmp];
 177       positions.splice(Math.max(randIndex, randIndex_tmp), 1);
 178       positions.splice(Math.min(randIndex, randIndex_tmp), 1);
 179
 180       randIndex = randInt(6);
 181       const knight1Pos = positions[randIndex];
 182       positions.splice(randIndex, 1);
 183       randIndex = randInt(5);
 184       const knight2Pos = positions[randIndex];
 185       positions.splice(randIndex, 1);
 186
 187       randIndex = randInt(4);
 188       const queenPos = positions[randIndex];
 189       positions.splice(randIndex, 1);
 190
 191       const rook1Pos = positions[0];
 192       const kingPos = positions[1];
 193       const rook2Pos = positions[2];
 194
 195       // Random squares for antikings
 196       antikingPos[c] = randInt(8);
 197
 198       pieces[c][rook1Pos] = "r";
 199       pieces[c][knight1Pos] = "n";
 200       pieces[c][bishop1Pos] = "b";
 201       pieces[c][queenPos] = "q";
 202       pieces[c][kingPos] = "k";
 203       pieces[c][bishop2Pos] = "b";
 204       pieces[c][knight2Pos] = "n";
 205       pieces[c][rook2Pos] = "r";
 206       flags += V.CoordToColumn(rook1Pos) + V.CoordToColumn(rook2Pos);
 207     }
 208     const ranks23_black =
 209       "pppppppp/" +
 210       (antikingPos["w"] > 0 ? antikingPos["w"] : "") +
 211       "A" +
 212       (antikingPos["w"] < 7 ? 7 - antikingPos["w"] : "");
 213     const ranks23_white =
 214       (antikingPos["b"] > 0 ? antikingPos["b"] : "") +
 215       "a" +
 216       (antikingPos["b"] < 7 ? 7 - antikingPos["b"] : "") +
 217       "/PPPPPPPP";
 218     return (
 219       pieces["b"].join("") +
 220       "/" +
 221       ranks23_black +
 222       "/8/8/" +
 223       ranks23_white +
 224       "/" +
 225       pieces["w"].join("").toUpperCase() +
 226       " w 0 " + flags + " -"
 227     );
 228   }
 229
 230   static get SEARCH_DEPTH() {
 231     return 2;
 232   }
 233 };