client/src/variants/Ball.js

   1 import { ChessRules, Move, PiPo } from "@/base_rules";
   2 import { ArrayFun } from "@/utils/array";
   3 import { shuffle } from "@/utils/alea";
   4
   5 export class BallRules extends ChessRules {
   6
   7   static get Lines() {
   8     return [
   9       // White goal:
  10       [[0, 3], [0, 6]],
  11       [[0, 6], [1, 6]],
  12       [[1, 6], [1, 3]],
  13       [[1, 3], [0, 3]],
  14       // Black goal:
  15       [[9, 3], [9, 6]],
  16       [[9, 6], [8, 6]],
  17       [[8, 6], [8, 3]],
  18       [[8, 3], [9, 3]]
  19     ];
  20   }
  21
  22   static get PawnSpecs() {
  23     return Object.assign(
  24       {},
  25       ChessRules.PawnSpecs,
  26       { promotions: ChessRules.PawnSpecs.promotions.concat([V.PHOENIX]) }
  27     );
  28   }
  29
  30   static get HasFlags() {
  31     return false;
  32   }
  33
  34   static get PHOENIX() {
  35     return 'h';
  36   }
  37
  38   static get BALL() {
  39     // 'b' is already taken:
  40     return "aa";
  41   }
  42
  43   static get HAS_BALL_CODE() {
  44     return {
  45       'p': 's',
  46       'r': 'u',
  47       'n': 'o',
  48       'b': 'c',
  49       'q': 't',
  50       'k': 'l',
  51       'h': 'i'
  52     };
  53   }
  54
  55   static get HAS_BALL_DECODE() {
  56     return {
  57       's': 'p',
  58       'u': 'r',
  59       'o': 'n',
  60       'c': 'b',
  61       't': 'q',
  62       'l': 'k',
  63       'i': 'h'
  64     };
  65   }
  66
  67   static get PIECES() {
  68     return ChessRules.PIECES
  69       .concat([V.PHOENIX])
  70       .concat(Object.keys(V.HAS_BALL_DECODE))
  71       .concat(['a']);
  72   }
  73
  74   static board2fen(b) {
  75     if (b == V.BALL) return 'a';
  76     return ChessRules.board2fen(b);
  77   }
  78
  79   static fen2board(f) {
  80     if (f == 'a') return V.BALL;
  81     return ChessRules.fen2board(f);
  82   }
  83
  84   static ParseFen(fen) {
  85     return Object.assign(
  86       ChessRules.ParseFen(fen),
  87       { pmove: fen.split(" ")[4] }
  88     );
  89   }
  90
  91   // Check that exactly one ball is on the board
  92   // + at least one piece per color.
  93   static IsGoodPosition(position) {
  94     if (position.length == 0) return false;
  95     const rows = position.split("/");
  96     if (rows.length != V.size.x) return false;
  97     let pieces = { "w": 0, "b": 0 };
  98     const withBall = Object.keys(V.HAS_BALL_DECODE).concat(['a']);
  99     let ballCount = 0;
 100     for (let row of rows) {
 101       let sumElts = 0;
 102       for (let i = 0; i < row.length; i++) {
 103         const lowerRi = row[i].toLowerCase();
 104         if (V.PIECES.includes(lowerRi)) {
 105           if (lowerRi != 'a') pieces[row[i] == lowerRi ? "b" : "w"]++;
 106           if (withBall.includes(lowerRi)) ballCount++;
 107           sumElts++;
 108         }
 109         else {
 110           const num = parseInt(row[i], 10);
 111           if (isNaN(num)) return false;
 112           sumElts += num;
 113         }
 114       }
 115       if (sumElts != V.size.y) return false;
 116     }
 117     if (ballCount != 1 || Object.values(pieces).some(v => v == 0))
 118       return false;
 119     return true;
 120   }
 121
 122   static IsGoodFen(fen) {
 123     if (!ChessRules.IsGoodFen(fen)) return false;
 124     const fenParts = fen.split(" ");
 125     if (fenParts.length != 5) return false;
 126     if (
 127       fenParts[4] != "-" &&
 128       !fenParts[4].match(/^([a-i][1-9]){2,2}$/)
 129     ) {
 130       return false;
 131     }
 132     return true;
 133   }
 134
 135   getPpath(b) {
 136     let prefix = "";
 137     const withPrefix =
 138       Object.keys(V.HAS_BALL_DECODE)
 139       .concat([V.PHOENIX])
 140       .concat(['a']);
 141     if (withPrefix.includes(b[1])) prefix = "Ball/";
 142     return prefix + b;
 143   }
 144
 145   getPPpath(m) {
 146     if (
 147       m.vanish.length == 2 &&
 148       m.appear.length == 2 &&
 149       m.appear[0].c != m.appear[1].c
 150     ) {
 151       // Take ball in place (from opponent)
 152       return "Ball/inplace";
 153     }
 154     return super.getPPpath(m);
 155   }
 156
 157   canTake([x1, y1], [x2, y2]) {
 158     if (this.getColor(x1, y1) !== this.getColor(x2, y2)) {
 159       // The piece holding the ball cannot capture:
 160       return (
 161         !(Object.keys(V.HAS_BALL_DECODE)
 162           .includes(this.board[x1][y1].charAt(1)))
 163       );
 164     }
 165     // Pass: possible only if one of the friendly pieces has the ball
 166     return (
 167       Object.keys(V.HAS_BALL_DECODE).includes(this.board[x1][y1].charAt(1)) ||
 168       Object.keys(V.HAS_BALL_DECODE).includes(this.board[x2][y2].charAt(1))
 169     );
 170   }
 171
 172   getFen() {
 173     return super.getFen() + " " + this.getPmoveFen();
 174   }
 175
 176   getFenForRepeat() {
 177     return super.getFenForRepeat() + "_" + this.getPmoveFen();
 178   }
 179
 180   getPmoveFen() {
 181     const L = this.pmoves.length;
 182     if (!this.pmoves[L-1]) return "-";
 183     return (
 184       V.CoordsToSquare(this.pmoves[L-1].start) +
 185       V.CoordsToSquare(this.pmoves[L-1].end)
 186     );
 187   }
 188
 189   static GenRandInitFen(randomness) {
 190     if (randomness == 0)
 191       return "hbnrqrnhb/ppppppppp/9/9/4a4/9/9/PPPPPPPPP/HBNRQRNHB w 0 - -";
 192
 193     let pieces = { w: new Array(9), b: new Array(9) };
 194     for (let c of ["w", "b"]) {
 195       if (c == 'b' && randomness == 1) {
 196         pieces['b'] = pieces['w'];
 197         break;
 198       }
 199
 200       // Get random squares for every piece, with bishops and phoenixes
 201       // on different colors:
 202       let positions = shuffle(ArrayFun.range(9));
 203       const composition = ['b', 'b', 'h', 'h', 'n', 'n', 'r', 'r', 'q'];
 204       let rem2 = positions[0] % 2;
 205       if (rem2 == positions[1] % 2) {
 206         // Fix bishops (on different colors)
 207         for (let i=4; i<9; i++) {
 208           if (positions[i] % 2 != rem2) {
 209             [positions[1], positions[i]] = [positions[i], positions[1]];
 210             break;
 211           }
 212         }
 213       }
 214       rem2 = positions[2] % 2;
 215       if (rem2 == positions[3] % 2) {
 216         // Fix phoenixes too:
 217         for (let i=4; i<9; i++) {
 218           if (positions[i] % 2 != rem2)
 219             [positions[3], positions[i]] = [positions[i], positions[3]];
 220         }
 221       }
 222       for (let i = 0; i < 9; i++) pieces[c][positions[i]] = composition[i];
 223     }
 224     return (
 225       pieces["b"].join("") +
 226       "/ppppppppp/9/9/4a4/9/9/PPPPPPPPP/" +
 227       pieces["w"].join("").toUpperCase() +
 228       " w 0 - -"
 229     );
 230   }
 231
 232   scanKings() {}
 233
 234   setOtherVariables(fen) {
 235     super.setOtherVariables(fen);
 236     const pmove = V.ParseFen(fen).pmove;
 237     // Local stack of "pass moves" (no need for appear & vanish)
 238     this.pmoves = [
 239       pmove != "-"
 240         ?
 241           {
 242             start: V.SquareToCoords(pmove.substr(0, 2)),
 243             end: V.SquareToCoords(pmove.substr(2))
 244           }
 245         : null
 246     ];
 247   }
 248
 249   static get size() {
 250     return { x: 9, y: 9 };
 251   }
 252
 253   getPiece(i, j) {
 254     const p = this.board[i][j].charAt(1);
 255     if (Object.keys(V.HAS_BALL_DECODE).includes(p))
 256       return V.HAS_BALL_DECODE[p];
 257     return p;
 258   }
 259
 260   static get steps() {
 261     return Object.assign(
 262       {},
 263       ChessRules.steps,
 264       // Add phoenix moves
 265       {
 266         h: [
 267           [-2, -2],
 268           [-2, 2],
 269           [2, -2],
 270           [2, 2],
 271           [-1, 0],
 272           [1, 0],
 273           [0, -1],
 274           [0, 1]
 275         ]
 276       }
 277     );
 278   }
 279
 280   // Because of the ball, getPiece() could be wrong:
 281   // use board[x][y][1] instead (always valid).
 282   getBasicMove([sx, sy], [ex, ey], tr) {
 283     const initColor = this.getColor(sx, sy);
 284     const initPiece = this.board[sx][sy].charAt(1);
 285     let mv = new Move({
 286       appear: [
 287         new PiPo({
 288           x: ex,
 289           y: ey,
 290           c: tr ? tr.c : initColor,
 291           p: tr ? tr.p : initPiece
 292         })
 293       ],
 294       vanish: [
 295         new PiPo({
 296           x: sx,
 297           y: sy,
 298           c: initColor,
 299           p: initPiece
 300         })
 301       ]
 302     });
 303
 304     // Fix "ball holding" indication in case of promotions:
 305     if (!!tr && Object.keys(V.HAS_BALL_DECODE).includes(initPiece))
 306       mv.appear[0].p = V.HAS_BALL_CODE[tr.p];
 307
 308     // The opponent piece disappears if we take it
 309     if (this.board[ex][ey] != V.EMPTY) {
 310       mv.vanish.push(
 311         new PiPo({
 312           x: ex,
 313           y: ey,
 314           c: this.getColor(ex, ey),
 315           p: this.board[ex][ey].charAt(1)
 316         })
 317       );
 318     }
 319
 320     // Post-processing: maybe the ball was taken, or a piece + ball,
 321     // or maybe a pass (ball <--> piece)
 322     if (mv.vanish.length == 2) {
 323       if (
 324         // Take the ball?
 325         mv.vanish[1].c == 'a' ||
 326         // Capture a ball-holding piece? If friendly one, then adjust
 327         Object.keys(V.HAS_BALL_DECODE).includes(mv.vanish[1].p)
 328       ) {
 329         mv.appear[0].p = V.HAS_BALL_CODE[mv.appear[0].p];
 330         if (mv.vanish[1].c == mv.vanish[0].c) {
 331           // "Capturing" self => pass
 332           mv.appear[0].x = mv.start.x;
 333           mv.appear[0].y = mv.start.y;
 334           mv.appear.push(
 335             new PiPo({
 336               x: mv.end.x,
 337               y: mv.end.y,
 338               p: V.HAS_BALL_DECODE[mv.vanish[1].p],
 339               c: mv.vanish[0].c
 340             })
 341           );
 342         }
 343       }
 344       else if (mv.vanish[1].c == mv.vanish[0].c) {
 345         // Pass the ball: the passing unit does not disappear
 346         mv.appear.push(JSON.parse(JSON.stringify(mv.vanish[0])));
 347         mv.appear[0].p = V.HAS_BALL_CODE[mv.vanish[1].p];
 348         mv.appear[1].p = V.HAS_BALL_DECODE[mv.appear[1].p];
 349       }
 350       // Else: standard capture
 351     }
 352
 353     return mv;
 354   }
 355
 356   // NOTE: if a pawn captures en-passant, he doesn't hold the ball
 357   // So base implementation is fine.
 358
 359   getPotentialMovesFrom([x, y]) {
 360     let moves = undefined;
 361     const piece = this.getPiece(x, y);
 362     if (piece == V.PHOENIX)
 363       moves = this.getPotentialPhoenixMoves([x, y]);
 364     else moves = super.getPotentialMovesFrom([x, y]);
 365     // Add "taking ball in place" move (at most one in list)
 366     for (let m of moves) {
 367       if (
 368         m.vanish.length == 2 &&
 369         m.vanish[1].p != 'a' &&
 370         m.vanish[0].c != m.vanish[1].c &&
 371         Object.keys(V.HAS_BALL_DECODE).includes(m.appear[0].p)
 372       ) {
 373         const color = this.turn;
 374         const oppCol = V.GetOppCol(color);
 375         moves.push(
 376           new Move({
 377             appear: [
 378               new PiPo({
 379                 x: x,
 380                 y: y,
 381                 c: color,
 382                 p: m.appear[0].p
 383               }),
 384               new PiPo({
 385                 x: m.vanish[1].x,
 386                 y: m.vanish[1].y,
 387                 c: oppCol,
 388                 p: V.HAS_BALL_DECODE[m.vanish[1].p]
 389               })
 390             ],
 391             vanish: [
 392               new PiPo({
 393                 x: x,
 394                 y: y,
 395                 c: color,
 396                 p: piece
 397               }),
 398               new PiPo({
 399                 x: m.vanish[1].x,
 400                 y: m.vanish[1].y,
 401                 c: oppCol,
 402                 p: m.vanish[1].p
 403               })
 404             ],
 405             end: { x: m.end.x, y: m.end.y }
 406           })
 407         );
 408         break;
 409       }
 410     }
 411     return moves;
 412   }
 413
 414   // "Sliders": at most 3 steps
 415   getSlideNJumpMoves([x, y], steps, oneStep) {
 416     let moves = [];
 417     outerLoop: for (let step of steps) {
 418       let i = x + step[0];
 419       let j = y + step[1];
 420       let stepCount = 1;
 421       while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
 422         moves.push(this.getBasicMove([x, y], [i, j]));
 423         if (oneStep || stepCount == 3) continue outerLoop;
 424         i += step[0];
 425         j += step[1];
 426         stepCount++;
 427       }
 428       if (V.OnBoard(i, j) && this.canTake([x, y], [i, j]))
 429         moves.push(this.getBasicMove([x, y], [i, j]));
 430     }
 431     return moves;
 432   }
 433
 434   getPotentialPhoenixMoves(sq) {
 435     return this.getSlideNJumpMoves(sq, V.steps[V.PHOENIX], "oneStep");
 436   }
 437
 438   getPmove(move) {
 439     if (
 440       move.vanish.length == 2 &&
 441       move.appear.length == 2 &&
 442       move.appear[0].c != move.appear[1].c
 443     ) {
 444       // In-place pass:
 445       return {
 446         start: move.start,
 447         end: move.end
 448       };
 449     }
 450     return null;
 451   }
 452
 453   oppositePasses(m1, m2) {
 454     return (
 455       m1.start.x == m2.end.x &&
 456       m1.start.y == m2.end.y &&
 457       m1.end.x == m2.start.x &&
 458       m1.end.y == m2.start.y
 459     );
 460   }
 461
 462   filterValid(moves) {
 463     const L = this.pmoves.length;
 464     const lp = this.pmoves[L-1];
 465     if (!lp) return moves;
 466     return moves.filter(m => {
 467       return (
 468         m.vanish.length == 1 ||
 469         m.appear.length == 1 ||
 470         m.appear[0].c == m.appear[1].c ||
 471         !this.oppositePasses(lp, m)
 472       );
 473     });
 474   }
 475
 476   // isAttacked: unused here (no checks)
 477
 478   postPlay(move) {
 479     this.pmoves.push(this.getPmove(move));
 480   }
 481
 482   postUndo() {
 483     this.pmoves.pop();
 484   }
 485
 486   getCheckSquares() {
 487     return [];
 488   }
 489
 490   getCurrentScore() {
 491     // Turn has changed:
 492     const color = V.GetOppCol(this.turn);
 493     const lastRank = (color == "w" ? 0 : 8);
 494     if ([3,4,5].some(
 495       i => {
 496         return (
 497           Object.keys(V.HAS_BALL_DECODE).includes(
 498             this.board[lastRank][i].charAt(1)) &&
 499           this.getColor(lastRank, i) == color
 500         );
 501       }
 502     )) {
 503       // Goal scored!
 504       return color == "w" ? "1-0" : "0-1";
 505     }
 506     if (this.atLeastOneMove()) return "*";
 507     // Stalemate (quite unlikely?)
 508     return "1/2";
 509   }
 510
 511   static get VALUES() {
 512     return {
 513       p: 1,
 514       r: 3,
 515       n: 3,
 516       b: 2,
 517       q: 5,
 518       h: 3,
 519       a: 0 //ball: neutral
 520     };
 521   }
 522
 523   static get SEARCH_DEPTH() {
 524     return 2;
 525   }
 526
 527   evalPosition() {
 528     // Count material:
 529     let evaluation = super.evalPosition();
 530     if (this.board[4][4] == V.BALL)
 531       // Ball not captured yet
 532       return evaluation;
 533     // Ponder depending on ball position
 534     for (let i=0; i<9; i++) {
 535       for (let j=0; j<9; j++) {
 536         if (Object.keys(V.HAS_BALL_DECODE).includes(this.board[i][j][1]))
 537           return evaluation/2 + (this.getColor(i, j) == "w" ? 8 - i : -i);
 538       }
 539     }
 540     return 0; //never reached
 541   }
 542
 543   getNotation(move) {
 544     const finalSquare = V.CoordsToSquare(move.end);
 545     if (move.appear.length == 2)
 546       // A pass: special notation
 547       return V.CoordsToSquare(move.start) + "P" + finalSquare;
 548     const piece = this.getPiece(move.start.x, move.start.y);
 549     if (piece == V.PAWN) {
 550       // Pawn move
 551       let notation = "";
 552       if (move.vanish.length > move.appear.length) {
 553         // Capture
 554         const startColumn = V.CoordToColumn(move.start.y);
 555         notation = startColumn + "x" + finalSquare;
 556       }
 557       else notation = finalSquare;
 558       if (![V.PAWN, V.HAS_BALL_CODE[V.PAWN]].includes(move.appear[0].p)) {
 559         // Promotion
 560         const promotePiece =
 561           V.HAS_BALL_DECODE[move.appear[0].p] || move.appear[0].p;
 562         notation += "=" + promotePiece.toUpperCase();
 563       }
 564       return notation;
 565     }
 566     // Piece movement
 567     return (
 568       piece.toUpperCase() +
 569       (move.vanish.length > move.appear.length ? "x" : "") +
 570       finalSquare
 571     );
 572   }
 573
 574 };