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 {
   7   static getPpath(b)
   8   {
   9     return b[1]=='a' ? "Antiking/"+b : b;
  10   }
  11
  12   static get ANTIKING() { return 'a'; }
  13
  14   static get PIECES()
  15   {
  16     return ChessRules.PIECES.concat([V.ANTIKING]);
  17   }
  18
  19   setOtherVariables(fen)
  20   {
  21     super.setOtherVariables(fen);
  22     this.antikingPos = {'w':[-1,-1], 'b':[-1,-1]};
  23     const rows = V.ParseFen(fen).position.split("/");
  24     for (let i=0; i<rows.length; i++)
  25     {
  26       let k = 0;
  27       for (let j=0; j<rows[i].length; j++)
  28       {
  29         switch (rows[i].charAt(j))
  30         {
  31           case 'a':
  32             this.antikingPos['b'] = [i,k];
  33             break;
  34           case 'A':
  35             this.antikingPos['w'] = [i,k];
  36             break;
  37           default:
  38             const num = parseInt(rows[i].charAt(j));
  39             if (!isNaN(num))
  40               k += (num-1);
  41         }
  42         k++;
  43       }
  44     }
  45   }
  46
  47   canTake([x1,y1], [x2,y2])
  48   {
  49     const piece1 = this.getPiece(x1,y1);
  50     const piece2 = this.getPiece(x2,y2);
  51     const color1 = this.getColor(x1,y1);
  52     const color2 = this.getColor(x2,y2);
  53     return piece2 != "a" &&
  54       ((piece1 != "a" && color1 != color2) || (piece1 == "a" && color1 == color2));
  55   }
  56
  57   getPotentialMovesFrom([x,y])
  58   {
  59     switch (this.getPiece(x,y))
  60     {
  61       case V.ANTIKING:
  62         return this.getPotentialAntikingMoves([x,y]);
  63       default:
  64         return super.getPotentialMovesFrom([x,y]);
  65     }
  66   }
  67
  68   getPotentialAntikingMoves(sq)
  69   {
  70     return this.getSlideNJumpMoves(sq,
  71       V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
  72   }
  73
  74   isAttacked(sq, colors)
  75   {
  76     return (super.isAttacked(sq, colors) || this.isAttackedByAntiking(sq, colors));
  77   }
  78
  79   isAttackedByKing([x,y], colors)
  80   {
  81     if (this.getPiece(x,y) == V.ANTIKING)
  82       return false; //antiking is not attacked by king
  83     return this.isAttackedBySlideNJump([x,y], colors, V.KING,
  84       V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
  85   }
  86
  87   isAttackedByAntiking([x,y], colors)
  88   {
  89     if ([V.KING,V.ANTIKING].includes(this.getPiece(x,y)))
  90       return false; //(anti)king is not attacked by antiking
  91     return this.isAttackedBySlideNJump([x,y], colors, V.ANTIKING,
  92       V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
  93   }
  94
  95   underCheck(color)
  96   {
  97     const oppCol = V.GetOppCol(color);
  98     let res = this.isAttacked(this.kingPos[color], [oppCol])
  99       || !this.isAttacked(this.antikingPos[color], [oppCol]);
 100     return res;
 101   }
 102
 103   getCheckSquares(color)
 104   {
 105     let res = super.getCheckSquares(color);
 106     if (!this.isAttacked(this.antikingPos[color], [V.GetOppCol(color)]))
 107       res.push(JSON.parse(JSON.stringify(this.antikingPos[color])));
 108     return res;
 109   }
 110
 111   updateVariables(move)
 112   {
 113     super.updateVariables(move);
 114     const piece = move.vanish[0].p;
 115     const c = move.vanish[0].c;
 116     // Update antiking position
 117     if (piece == V.ANTIKING)
 118     {
 119       this.antikingPos[c][0] = move.appear[0].x;
 120       this.antikingPos[c][1] = move.appear[0].y;
 121     }
 122   }
 123
 124   unupdateVariables(move)
 125   {
 126     super.unupdateVariables(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   {
 134     if (this.atLeastOneMove()) // game not over
 135       return "*";
 136
 137     const color = this.turn;
 138     const oppCol = V.GetOppCol(color);
 139     if (!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       ChessRules.VALUES,
 150       { 'a': 1000 }
 151     );
 152   }
 153
 154   static GenRandInitFen()
 155   {
 156     let pieces = { "w": new Array(8), "b": new Array(8) };
 157     let antikingPos = { "w": -1, "b": -1 };
 158     for (let c of ["w","b"])
 159     {
 160       let positions = ArrayFun.range(8);
 161
 162       // Get random squares for bishops, but avoid corners; because,
 163       // if an antiking blocks a cornered bishop, it can never be checkmated
 164       let randIndex = 2 * randInt(1,4);
 165       const bishop1Pos = positions[randIndex];
 166       let randIndex_tmp = 2 * randInt(3) + 1;
 167       const bishop2Pos = positions[randIndex_tmp];
 168       positions.splice(Math.max(randIndex,randIndex_tmp), 1);
 169       positions.splice(Math.min(randIndex,randIndex_tmp), 1);
 170
 171       randIndex = randInt(6);
 172       const knight1Pos = positions[randIndex];
 173       positions.splice(randIndex, 1);
 174       randIndex = randInt(5);
 175       const knight2Pos = positions[randIndex];
 176       positions.splice(randIndex, 1);
 177
 178       randIndex = randInt(4);
 179       const queenPos = positions[randIndex];
 180       positions.splice(randIndex, 1);
 181
 182       const rook1Pos = positions[0];
 183       const kingPos = positions[1];
 184       const rook2Pos = positions[2];
 185
 186       // Random squares for antikings
 187       antikingPos[c] = randInt(8);
 188
 189       pieces[c][rook1Pos] = 'r';
 190       pieces[c][knight1Pos] = 'n';
 191       pieces[c][bishop1Pos] = 'b';
 192       pieces[c][queenPos] = 'q';
 193       pieces[c][kingPos] = 'k';
 194       pieces[c][bishop2Pos] = 'b';
 195       pieces[c][knight2Pos] = 'n';
 196       pieces[c][rook2Pos] = 'r';
 197     }
 198     const ranks23_black = "pppppppp/" + (antikingPos["w"]>0?antikingPos["w"]:"")
 199       + "A" + (antikingPos["w"]<7?7-antikingPos["w"]:"");
 200     const ranks23_white = (antikingPos["b"]>0?antikingPos["b"]:"") + "a"
 201       + (antikingPos["b"]<7?7-antikingPos["b"]:"") + "/PPPPPPPP";
 202     return pieces["b"].join("") + "/" + ranks23_black +
 203       "/8/8/" +
 204       ranks23_white + "/" + pieces["w"].join("").toUpperCase() +
 205       " w 0 1111 -";
 206   }
 207 }