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