client/src/variants/Titan.js

   1 import { ChessRules, Move, PiPo } from "@/base_rules";
   2
   3 export class TitanRules extends ChessRules {
   4
   5   static get IMAGE_EXTENSION() {
   6     // Temporarily, for the time SVG pieces are being designed:
   7     return ".png";
   8   }
   9
  10   // Decode if normal piece, or + bishop or knight
  11   getPiece(x, y) {
  12     const piece = this.board[x][y].charAt(1);
  13     if (ChessRules.PIECES.includes(piece)) return piece;
  14     // Augmented piece:
  15     switch (piece) {
  16       case 'a':
  17       case 'c':
  18         return 'b';
  19       case 'j':
  20       case 'l':
  21         return 'k';
  22       case 'm':
  23       case 'o':
  24         return 'n';
  25       case 's':
  26       case 't':
  27         return 'q';
  28       case 'u':
  29       case 'v':
  30         return 'r';
  31     }
  32   }
  33
  34   // Code: a/c = bishop + knight/bishop j/l for king,
  35   // m/o for knight, s/t for queen, u/v for rook
  36   static get AUGMENTED_PIECES() {
  37     return [
  38       'a',
  39       'c',
  40       'j',
  41       'l',
  42       'm',
  43       'o',
  44       's',
  45       't',
  46       'u',
  47       'v'
  48     ];
  49   }
  50
  51   getPpath(b) {
  52     return "Titan/" + b;
  53   }
  54
  55   // Decode above notation into additional piece
  56   getExtraPiece(symbol) {
  57     if (['a','j','m','s','u'].includes(symbol))
  58       return 'n';
  59     return 'b';
  60   }
  61
  62   // Inverse operation: augment piece
  63   getAugmented(piece) {
  64     const knight = this.movesCount <= 1;
  65     switch (piece) {
  66       case V.ROOK: return (knight ? 'u' : 'v');
  67       case V.KNIGHT: return (knight ? 'm' : 'o');
  68       case V.BISHOP: return (knight ? 'a' : 'c');
  69       case V.QUEEN: return (knight ? 's' : 't');
  70       case V.KING: return (knight ? 'j' : 'l');
  71     }
  72     return '_'; //never reached
  73   }
  74
  75   static IsGoodPosition(position) {
  76     if (position.length == 0) return false;
  77     const rows = position.split("/");
  78     if (rows.length != V.size.x) return false;
  79     let kings = { "w": 0, "b": 0 };
  80     const allPiecesCodes = V.PIECES.concat(V.AUGMENTED_PIECES);
  81     const kingBlackCodes = ['j','k','l'];
  82     const kingWhiteCodes = ['J','K','L'];
  83     for (let row of rows) {
  84       let sumElts = 0;
  85       for (let i = 0; i < row.length; i++) {
  86         if (kingBlackCodes.includes(row[i])) kings['b']++;
  87         else if (kingWhiteCodes.includes(row[i])) kings['w']++;
  88         if (allPiecesCodes.includes(row[i].toLowerCase())) sumElts++;
  89         else {
  90           const num = parseInt(row[i], 10);
  91           if (isNaN(num)) return false;
  92           sumElts += num;
  93         }
  94       }
  95       if (sumElts != V.size.y) return false;
  96     }
  97     // Both kings should be on board, only one of each color:
  98     if (Object.values(kings).some(v => v != 1)) return false;
  99     return true;
 100   }
 101
 102   // Kings may be augmented:
 103   scanKings(fen) {
 104     this.kingPos = { w: [-1, -1], b: [-1, -1] };
 105     const rows = V.ParseFen(fen).position.split("/");
 106     for (let i = 0; i < rows.length; i++) {
 107       let k = 0; //column index on board
 108       for (let j = 0; j < rows[i].length; j++) {
 109         const piece = rows[i].charAt(j);
 110         if (['j','k','l'].includes(piece.toLowerCase())) {
 111           const color = (piece.charCodeAt(0) <= 90 ? 'w' : 'b');
 112           this.kingPos[color] = [i, k];
 113         }
 114         else {
 115           const num = parseInt(rows[i].charAt(j), 10);
 116           if (!isNaN(num)) k += num - 1;
 117         }
 118         k++;
 119       }
 120     }
 121   }
 122
 123   // If piece not in usual list, bishop or knight appears.
 124   getPotentialMovesFrom([x, y]) {
 125     if (this.movesCount <= 3) {
 126       // Setup stage
 127       const color = this.getColor(x, y);
 128       const firstRank = (color == 'w' ? 7 : 0);
 129       if (x != firstRank || V.AUGMENTED_PIECES.includes(this.board[x][y][1]))
 130         return [];
 131       const piece = this.getPiece(x, y);
 132       const move = new Move({
 133         appear: [
 134           new PiPo({ x: x, y: y, c: color, p: this.getAugmented(piece) })
 135         ],
 136         vanish: [
 137           new PiPo({ x: x, y: y, c: color, p: piece })
 138         ],
 139         start: { x: x, y: y },
 140         end: { x: x, y: y }
 141       });
 142       return [move];
 143     }
 144     let moves = super.getPotentialMovesFrom([x, y]);
 145     const initialPiece = this.getPiece(x, y);
 146     const color = this.turn;
 147     if (
 148       V.AUGMENTED_PIECES.includes(this.board[x][y][1]) &&
 149       ((color == 'w' && x == 7) || (color == "b" && x == 0))
 150     ) {
 151       const newPiece = this.getExtraPiece(this.board[x][y][1]);
 152       moves.forEach(m => {
 153         m.appear[0].p = initialPiece;
 154         m.appear.push(
 155           new PiPo({
 156             p: newPiece,
 157             c: color,
 158             x: x,
 159             y: y
 160           })
 161         );
 162       });
 163     }
 164     moves.forEach(m => {
 165       if (m.vanish.length <= 1) return;
 166       const [vx, vy] = [m.vanish[1].x, m.vanish[1].y];
 167       if (
 168         m.appear.length >= 2 && //3 if the king was also augmented
 169         m.vanish.length == 2 &&
 170         m.vanish[1].c == color &&
 171         V.AUGMENTED_PIECES.includes(this.board[vx][vy][1])
 172       ) {
 173         // Castle, rook is an "augmented piece"
 174         m.appear[1].p = V.ROOK;
 175         m.appear.push(
 176           new PiPo({
 177             p: this.getExtraPiece(this.board[vx][vy][1]),
 178             c: color,
 179             x: vx,
 180             y: vy
 181           })
 182         );
 183       }
 184     });
 185     return moves;
 186   }
 187
 188   // Special case of move 1 = choose squares, knight first, then bishop
 189   doClick(square) {
 190     if (this.movesCount >= 4) return null;
 191     const color = this.turn;
 192     const [x, y] = [square[0], square[1]];
 193     if ((color == 'w' && x != 7) || (color == 'b' && x != 0)) return null;
 194     const selectedPiece = this.board[x][y][1];
 195     return new Move({
 196       appear: [
 197         new PiPo({
 198           x: x,
 199           y: y,
 200           c: color,
 201           p: this.getAugmented(selectedPiece)
 202         })
 203       ],
 204       vanish: [
 205         new PiPo({
 206           x: x,
 207           y: y,
 208           c: color,
 209           p: selectedPiece
 210         })
 211       ],
 212       start: { x: x, y: y },
 213       end: { x: x, y: y }
 214     });
 215   }
 216
 217   postPlay(move) {
 218     if (this.movesCount > 4) super.postPlay(move);
 219   }
 220
 221   postUndo(move) {
 222     if (this.movesCount >= 4) super.postUndo(move);
 223   }
 224
 225   evalPosition() {
 226     let evaluation = 0;
 227     for (let i = 0; i < V.size.x; i++) {
 228       for (let j = 0; j < V.size.y; j++) {
 229         if (this.board[i][j] != V.EMPTY) {
 230           const sign = this.getColor(i, j) == "w" ? 1 : -1;
 231           const piece = this.getPiece(i, j);
 232           evaluation += sign * V.VALUES[piece];
 233           const symbol = this.board[i][j][1];
 234           if (V.AUGMENTED_PIECES.includes(symbol)) {
 235             const extraPiece = this.getExtraPiece(symbol);
 236             evaluation += sign * V.VALUES[extraPiece]
 237           }
 238         }
 239       }
 240     }
 241     return evaluation;
 242   }
 243
 244   getNotation(move) {
 245     if (
 246       move.appear[0].x != move.vanish[0].x ||
 247       move.appear[0].y != move.vanish[0].y
 248     ) {
 249       if (
 250         V.AUGMENTED_PIECES.includes(move.vanish[0].p) ||
 251         (
 252           move.vanish.length >= 2 &&
 253           V.AUGMENTED_PIECES.includes(move.vanish[1].p)
 254         )
 255       ) {
 256         // Simplify move before calling super.getNotation()
 257         let smove = JSON.parse(JSON.stringify(move));
 258         if (ChessRules.PIECES.includes(move.vanish[0].p)) {
 259           // Castle with an augmented rook
 260           smove.appear.pop();
 261           smove.vanish[1].p = smove.appear[1].p;
 262         }
 263         else {
 264           // Moving an augmented piece
 265           smove.appear.pop();
 266           smove.vanish[0].p = smove.appear[0].p;
 267           if (
 268             smove.vanish.length == 2 &&
 269             smove.vanish[0].c == smove.vanish[1].c &&
 270             V.AUGMENTED_PIECES.includes(move.vanish[1].p)
 271           ) {
 272             // Castle with an augmented rook
 273             smove.appear.pop();
 274             smove.vanish[1].p = smove.appear[1].p;
 275           }
 276         }
 277         return super.getNotation(smove);
 278       }
 279       // Else, more common case:
 280       return super.getNotation(move);
 281     }
 282     // First moves in game, placements:
 283     const square = V.CoordsToSquare(move.appear[0]);
 284     const reserve =
 285       (['a','j','m','s','u'].includes(move.appear[0].p) ? 'N' : 'B');
 286     return '+' + reserve + '@' + square;
 287   }
 288
 289 };