client/src/variants/Antiking1.js

   1 import { ChessRules } from "@/base_rules";
   2 import { BerolinaRules } from "@/variants/Berolina";
   3 import { ArrayFun } from "@/utils/array";
   4 import { randInt } from "@/utils/alea";
   5
   6 export class Antiking1Rules extends BerolinaRules {
   7   static get PawnSpecs() {
   8     return Object.assign(
   9       {},
  10       ChessRules.PawnSpecs,
  11       { twoSquares: false }
  12     );
  13   }
  14
  15   static get HasCastle() {
  16     return false;
  17   }
  18
  19   static get ANTIKING() {
  20     return "a";
  21   }
  22
  23   static get PIECES() {
  24     return ChessRules.PIECES.concat([V.ANTIKING]);
  25   }
  26
  27   getPpath(b) {
  28     return b[1] == "a" ? "Antiking/" + b : b;
  29   }
  30
  31   static IsGoodPosition(position) {
  32     if (!ChessRules.IsGoodPosition(position)) return false;
  33     const rows = position.split("/");
  34     // Check that exactly one antiking of each color is there:
  35     let antikings = { 'a': 0, 'A': 0 };
  36     for (let row of rows) {
  37       for (let i = 0; i < row.length; i++)
  38         if (['A','a'].includes(row[i])) antikings[row[i]]++;
  39     }
  40     if (Object.values(antikings).some(v => v != 1)) return false;
  41     return true;
  42   }
  43
  44   setOtherVariables(fen) {
  45     super.setOtherVariables(fen);
  46     this.antikingPos = { w: [-1, -1], b: [-1, -1] };
  47     const rows = V.ParseFen(fen).position.split("/");
  48     for (let i = 0; i < rows.length; i++) {
  49       let k = 0;
  50       for (let j = 0; j < rows[i].length; j++) {
  51         switch (rows[i].charAt(j)) {
  52           case "a":
  53             this.antikingPos["b"] = [i, k];
  54             break;
  55           case "A":
  56             this.antikingPos["w"] = [i, k];
  57             break;
  58           default: {
  59             const num = parseInt(rows[i].charAt(j), 10);
  60             if (!isNaN(num)) k += num - 1;
  61           }
  62         }
  63         k++;
  64       }
  65     }
  66   }
  67
  68   // (Anti)King flags at 1 (true) if they can knight-jump
  69   setFlags(fenflags) {
  70     this.kingFlags = {
  71       // King then antiking
  72       w: [...Array(2).fill(false)],
  73       b: [...Array(2).fill(false)]
  74     };
  75     for (let c of ["w", "b"]) {
  76       for (let i = 0; i < 2; i++)
  77         this.kingFlags[c][i] = fenflags.charAt((c == "w" ? 0 : 2) + i) == "1";
  78     }
  79   }
  80
  81   aggregateFlags() {
  82     return this.kingFlags;
  83   }
  84
  85   disaggregateFlags(flags) {
  86     this.kingFlags = flags;
  87   }
  88
  89   getFlagsFen() {
  90     // Return kings flags
  91     let flags = "";
  92     for (let c of ["w", "b"]) {
  93       for (let i = 0; i < 2; i++) flags += this.kingFlags[c][i] ? "1" : "0";
  94     }
  95     return flags;
  96   }
  97
  98   canTake([x1, y1], [x2, y2]) {
  99     const piece1 = this.getPiece(x1, y1);
 100     const piece2 = this.getPiece(x2, y2);
 101     const color1 = this.getColor(x1, y1);
 102     const color2 = this.getColor(x2, y2);
 103     return (
 104       piece2 != "a" &&
 105       ((piece1 != "a" && color1 != color2) ||
 106         (piece1 == "a" && color1 == color2))
 107     );
 108   }
 109
 110   getPotentialMovesFrom([x, y]) {
 111     let moves = [];
 112     let addKnightJumps = false;
 113     const piece = this.getPiece(x, y);
 114     const color = this.getColor(x, y);
 115     if (piece == V.ANTIKING) {
 116       moves = this.getPotentialAntikingMoves([x, y]);
 117       addKnightJumps = this.kingFlags[color][1];
 118     } else {
 119       moves = super.getPotentialMovesFrom([x, y]);
 120       if (piece == V.KING) addKnightJumps = this.kingFlags[color][0];
 121     }
 122     if (addKnightJumps) {
 123       // Add potential knight jump to (anti)kings
 124       const knightJumps = super.getPotentialKnightMoves([x, y]);
 125       // Remove captures (TODO: could be done more efficiently...)
 126       moves = moves.concat(knightJumps.filter(m => m.vanish.length == 1));
 127     }
 128     return moves;
 129   }
 130
 131   getPotentialAntikingMoves(sq) {
 132     // The antiking moves like a king (only captured colors differ)
 133     return this.getSlideNJumpMoves(
 134       sq,
 135       V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
 136       "oneStep"
 137     );
 138   }
 139
 140   isAttacked(sq, color) {
 141     return (
 142       super.isAttacked(sq, color) ||
 143       this.isAttackedByAntiking(sq, color)
 144     );
 145   }
 146
 147   isAttackedByKing([x, y], color) {
 148     // Antiking is not attacked by king:
 149     if (this.getPiece(x, y) == V.ANTIKING) return false;
 150     return this.isAttackedBySlideNJump(
 151       [x, y],
 152       color,
 153       V.KING,
 154       V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
 155       "oneStep"
 156     );
 157   }
 158
 159   isAttackedByAntiking([x, y], color) {
 160     // (Anti)King is not attacked by antiking
 161     if ([V.KING, V.ANTIKING].includes(this.getPiece(x, y))) return false;
 162     return this.isAttackedBySlideNJump(
 163       [x, y],
 164       color,
 165       V.ANTIKING,
 166       V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
 167       "oneStep"
 168     );
 169   }
 170
 171   underCheck(color) {
 172     const oppCol = V.GetOppCol(color);
 173     let res =
 174       this.isAttacked(this.kingPos[color], oppCol) ||
 175       !this.isAttacked(this.antikingPos[color], oppCol);
 176     return res;
 177   }
 178
 179   getCheckSquares() {
 180     const color = this.turn;
 181     let res = [];
 182     const oppCol = V.GetOppCol(color);
 183     if (this.isAttacked(this.kingPos[color], oppCol))
 184       res.push(JSON.parse(JSON.stringify(this.kingPos[color])));
 185     if (!this.isAttacked(this.antikingPos[color], oppCol))
 186       res.push(JSON.parse(JSON.stringify(this.antikingPos[color])));
 187     return res;
 188   }
 189
 190   postPlay(move) {
 191     super.postPlay(move);
 192     const piece = move.vanish[0].p;
 193     const c = move.vanish[0].c;
 194     // Update antiking position, and kings flags
 195     if (piece == V.ANTIKING) {
 196       this.antikingPos[c][0] = move.appear[0].x;
 197       this.antikingPos[c][1] = move.appear[0].y;
 198       this.kingFlags[c][1] = false;
 199     } else if (piece == V.KING) this.kingFlags[c][0] = false;
 200   }
 201
 202   postUndo(move) {
 203     super.postUndo(move);
 204     const c = move.vanish[0].c;
 205     if (move.vanish[0].p == V.ANTIKING)
 206       this.antikingPos[c] = [move.start.x, move.start.y];
 207   }
 208
 209   static get VALUES() {
 210     return Object.assign(
 211       { a: 1000 },
 212       ChessRules.VALUES
 213     );
 214   }
 215
 216   static GenRandInitFen() {
 217     // Always deterministic setup
 218     return "2prbkqA/2p1nnbr/2pppppp/8/8/PPPPPP2/RBNN1P2/aQKBRP2 w 0 1111";
 219   }
 220
 221   static get SEARCH_DEPTH() {
 222     return 2;
 223   }
 224 };