variants/Baroque/class.js

   1 import ChessRules from "/base_rules.js";
   2 import GiveawayRules from "/variants/Giveaway/class.js";
   3 import {Random} from "/utils/alea.js";
   4 import PiPo from "/utils/PiPo.js";
   5 import Move from "/utils/Move.js";
   6
   7 export default class BaroqueRules extends ChessRules {
   8
   9   static get Options() {
  10     return {
  11       select: C.Options.Select,
  12       input: [
  13         {
  14           label: "Capture king",
  15           variable: "taking",
  16           type: "checkbox",
  17           defaut: false
  18         }
  19       ],
  20       styles: [
  21         "balance",
  22         "capture",
  23         "crazyhouse",
  24         "cylinder",
  25         "doublemove",
  26         "progressive",
  27         "recycle",
  28         "teleport"
  29       ]
  30     };
  31   }
  32
  33   get hasFlags() {
  34     return false;
  35   }
  36   get hasEnpassant() {
  37     return false;
  38   }
  39
  40   genRandInitBaseFen() {
  41     if (this.options["randomness"] == 0)
  42       return "rnbkqbnm/pppppppp/8/8/8/8/PPPPPPPP/MNBQKBNR";
  43     const options = Object.assign({mode: "suicide"}, this.options);
  44     const gr = new GiveawayRules({options: options, genFenOnly: true});
  45     let res = gr.genRandInitBaseFen();
  46     let immPos = {};
  47     for (let c of ['w', 'b']) {
  48       const rookChar = (c == 'w' ? 'R' : 'r');
  49       switch (Random.randInt(2)) {
  50         case 0:
  51           immPos[c] = res.fen.indexOf(rookChar);
  52           break;
  53         case 1:
  54           immPos[c] = res.fen.lastIndexOf(rookChar);
  55           break;
  56       }
  57     }
  58     res.fen = res.fen.substring(0, immPos['b']) + 'i' +
  59               res.fen.substring(immPos['b'] + 1, immPos['w']) + 'I' +
  60               res.fen.substring(immPos['w'] + 1);
  61     return res;
  62   }
  63
  64   // Although other pieces keep their names here for coding simplicity,
  65   // keep in mind that:
  66   //  - a "rook" is a coordinator, capturing by coordinating with the king
  67   //  - a "knight" is a long-leaper, capturing as in draughts
  68   //  - a "bishop" is a chameleon, capturing as its prey
  69   //  - a "queen" is a withdrawer, capturing by moving away from pieces
  70
  71   pieces() {
  72     return Object.assign({},
  73       super.pieces(),
  74       {
  75         'p': {
  76           "class": "pawn",
  77           moves: [
  78             {steps: [[0, 1], [0, -1], [1, 0], [-1, 0]]}
  79           ]
  80         },
  81         'r': {
  82           "class": "rook",
  83           moves: [
  84             {
  85               steps: [
  86                 [1, 0], [0, 1], [-1, 0], [0, -1],
  87                 [1, 1], [1, -1], [-1, 1], [-1, -1]
  88               ]
  89             }
  90           ]
  91         },
  92         'n': {
  93           "class": "knight",
  94           moveas: 'r'
  95         },
  96         'b': {
  97           "class": "bishop",
  98           moveas: 'r'
  99         },
 100         'q': {
 101           "class": "queen",
 102           moveas: 'r'
 103         },
 104         'i': {
 105           "class": "immobilizer",
 106           moveas: 'q'
 107         }
 108       }
 109     );
 110   }
 111
 112   // Is piece on square (x,y) immobilized?
 113   isImmobilized([x, y]) {
 114     const piece = this.getPiece(x, y);
 115     const color = this.getColor(x, y);
 116     const oppCol = C.GetOppCol(color);
 117     const adjacentSteps = this.pieces()['k'].moves[0].steps;
 118     for (let step of adjacentSteps) {
 119       const [i, j] = [x + step[0], this.getY(y + step[1])];
 120       if (
 121         this.onBoard(i, j) &&
 122         this.board[i][j] != "" &&
 123         this.getColor(i, j) == oppCol
 124       ) {
 125         const oppPiece = this.getPiece(i, j);
 126         if (oppPiece == 'i') {
 127           // Moving is possible only if this immobilizer is neutralized
 128           for (let step2 of adjacentSteps) {
 129             const [i2, j2] = [i + step2[0], this.getY(j + step2[1])];
 130             if (i2 == x && j2 == y)
 131               continue; //skip initial piece!
 132             if (
 133               this.onBoard(i2, j2) &&
 134               this.board[i2][j2] != "" &&
 135               this.getColor(i2, j2) == color
 136             ) {
 137               if (['b', 'i'].includes(this.getPiece(i2, j2)))
 138                 return false;
 139             }
 140           }
 141           return true; //immobilizer isn't neutralized
 142         }
 143         // Chameleons can't be immobilized twice,
 144         // because there is only one immobilizer
 145         if (oppPiece == 'b' && piece == 'i')
 146           return true;
 147       }
 148     }
 149     return false;
 150   }
 151
 152   canTake([x1, y1], [x2, y2]) {
 153     // Deactivate standard captures, except for king:
 154     return (
 155       this.getPiece(x1, y1) == 'k' &&
 156       this.getColor(x1, y1) != this.getColor(x2, y2)
 157     );
 158   }
 159
 160   postProcessPotentialMoves(moves) {
 161     if (moves.length == 0)
 162       return [];
 163     switch (moves[0].vanish[0].p) {
 164       case 'p':
 165         this.addPawnCaptures(moves);
 166         break;
 167       case 'r':
 168         this.addRookCaptures(moves);
 169         break;
 170       case 'n':
 171         const [x, y] = [moves[0].start.x, moves[0].start.y];
 172         moves = moves.concat(this.getKnightCaptures([x, y]));
 173         break;
 174       case 'b':
 175         moves = this.getBishopCaptures(moves);
 176         break;
 177       case 'q':
 178         this.addQueenCaptures(moves);
 179         break;
 180     }
 181     return moves;
 182   }
 183
 184   // Modify capturing moves among listed pawn moves
 185   addPawnCaptures(moves, byChameleon) {
 186     const steps = this.pieces()['p'].moves[0].steps;
 187     const color = this.turn;
 188     const oppCol = C.GetOppCol(color);
 189     moves.forEach(m => {
 190       if (byChameleon && m.start.x != m.end.x && m.start.y != m.end.y)
 191         // Chameleon not moving as pawn
 192         return;
 193       // Try capturing in every direction
 194       for (let step of steps) {
 195         const sq2 = [m.end.x + 2 * step[0], this.getY(m.end.y + 2 * step[1])];
 196         if (
 197           this.onBoard(sq2[0], sq2[1]) &&
 198           this.board[sq2[0]][sq2[1]] != "" &&
 199           this.getColor(sq2[0], sq2[1]) == color
 200         ) {
 201           // Potential capture
 202           const sq1 = [m.end.x + step[0], this.getY(m.end.y + step[1])];
 203           if (
 204             this.board[sq1[0]][sq1[1]] != "" &&
 205             this.getColor(sq1[0], sq1[1]) == oppCol
 206           ) {
 207             const piece1 = this.getPiece(sq1[0], sq1[1]);
 208             if (!byChameleon || piece1 == 'p') {
 209               m.vanish.push(
 210                 new PiPo({
 211                   x: sq1[0],
 212                   y: sq1[1],
 213                   c: oppCol,
 214                   p: piece1
 215                 })
 216               );
 217             }
 218           }
 219         }
 220       }
 221     });
 222   }
 223
 224   addRookCaptures(moves, byChameleon) {
 225     const color = this.turn;
 226     const oppCol = V.GetOppCol(color);
 227     const kp = this.searchKingPos(color)[0];
 228     moves.forEach(m => {
 229       // Check piece-king rectangle (if any) corners for enemy pieces
 230       if (m.end.x == kp[0] || m.end.y == kp[1])
 231         return; //"flat rectangle"
 232       const corner1 = [m.end.x, kp[1]];
 233       const corner2 = [kp[0], m.end.y];
 234       for (let [i, j] of [corner1, corner2]) {
 235         if (this.board[i][j] != "" && this.getColor(i, j) == oppCol) {
 236           const piece = this.getPiece(i, j);
 237           if (!byChameleon || piece == 'r') {
 238             m.vanish.push(
 239               new PiPo({
 240                 x: i,
 241                 y: j,
 242                 p: piece,
 243                 c: oppCol
 244               })
 245             );
 246           }
 247         }
 248       }
 249     });
 250   }
 251
 252   getKnightCaptures(startSquare, byChameleon) {
 253     // Look in every direction for captures
 254     const steps = this.pieces()['r'].moves[0].steps;
 255     const color = this.turn;
 256     const oppCol = C.GetOppCol(color);
 257     let moves = [];
 258     const [x, y] = [startSquare[0], startSquare[1]];
 259     const piece = this.getPiece(x, y); //might be a chameleon!
 260     outerLoop: for (let step of steps) {
 261       let [i, j] = [x + step[0], this.getY(y + step[1])];
 262       while (this.onBoard(i, j) && this.board[i][j] == "")
 263         [i, j] = [i + step[0], this.getY(j + step[1])];
 264       if (
 265         !this.onBoard(i, j) ||
 266         this.getColor(i, j) == color ||
 267         (byChameleon && this.getPiece(i, j) != 'n')
 268       ) {
 269         continue;
 270       }
 271       // last(thing), cur(thing) : stop if "cur" is our color,
 272       // or beyond board limits, or if "last" isn't empty and cur neither.
 273       // Otherwise, if cur is empty then add move until cur square;
 274       // if cur is occupied then stop if !!byChameleon and the square not
 275       // occupied by a leaper.
 276       let last = [i, j];
 277       let cur = [i + step[0], this.getY(j + step[1])];
 278       let vanished = [new PiPo({x: x, y: y, c: color, p: piece})];
 279       while (this.onBoard(cur[0], cur[1])) {
 280         if (this.board[last[0]][last[1]] != "") {
 281           const oppPiece = this.getPiece(last[0], last[1]);
 282           if (!!byChameleon && oppPiece != 'n')
 283             continue outerLoop;
 284           // Something to eat:
 285           vanished.push(
 286             new PiPo({x: last[0], y: last[1], c: oppCol, p: oppPiece})
 287           );
 288         }
 289         if (this.board[cur[0]][cur[1]] != "") {
 290           if (
 291             this.getColor(cur[0], cur[1]) == color ||
 292             this.board[last[0]][last[1]] != ""
 293           ) {
 294             //TODO: redundant test
 295             continue outerLoop;
 296           }
 297         }
 298         else {
 299           moves.push(
 300             new Move({
 301               appear: [new PiPo({x: cur[0], y: cur[1], c: color, p: piece})],
 302               vanish: JSON.parse(JSON.stringify(vanished)), //TODO: required?
 303               start: {x: x, y: y},
 304               end: {x: cur[0], y: cur[1]}
 305             })
 306           );
 307         }
 308         last = [last[0] + step[0], this.getY(last[1] + step[1])];
 309         cur = [cur[0] + step[0], this.getY(cur[1] + step[1])];
 310       }
 311     }
 312     return moves;
 313   }
 314
 315   // Chameleon
 316   getBishopCaptures(moves) {
 317     const [x, y] = [moves[0].start.x, moves[0].start.y];
 318     moves = moves.concat(this.getKnightCaptures([x, y], "asChameleon"));
 319     // No "king capture" because king cannot remain under check
 320     this.addPawnCaptures(moves, "asChameleon");
 321     this.addRookCaptures(moves, "asChameleon");
 322     this.addQueenCaptures(moves, "asChameleon");
 323     // Post-processing: merge similar moves, concatenating vanish arrays
 324     let mergedMoves = {};
 325     moves.forEach(m => {
 326       const key = m.end.x + this.size.x * m.end.y;
 327       if (!mergedMoves[key])
 328         mergedMoves[key] = m;
 329       else {
 330         for (let i = 1; i < m.vanish.length; i++)
 331           mergedMoves[key].vanish.push(m.vanish[i]);
 332       }
 333     });
 334     return Object.values(mergedMoves);
 335   }
 336
 337   addQueenCaptures(moves, byChameleon) {
 338     if (moves.length == 0)
 339       return;
 340     const [x, y] = [moves[0].start.x, moves[0].start.y];
 341     const adjacentSteps = this.pieces()['r'].moves[0].steps;
 342     let capturingDirections = {};
 343     const color = this.turn;
 344     const oppCol = C.GetOppCol(color);
 345     adjacentSteps.forEach(step => {
 346       const [i, j] = [x - step[0], this.getY(y - step[1])];
 347       if (
 348         this.onBoard(i, j) &&
 349         this.board[i][j] != "" &&
 350         this.getColor(i, j) == oppCol &&
 351         (!byChameleon || this.getPiece(i, j) == 'q')
 352       ) {
 353         capturingDirections[step[0] + "." + step[1]] = true;
 354       }
 355     });
 356     moves.forEach(m => {
 357       const step = [
 358         m.end.x != x ? (m.end.x - x) / Math.abs(m.end.x - x) : 0,
 359         m.end.y != y ? (m.end.y - y) / Math.abs(m.end.y - y) : 0
 360       ];
 361       if (capturingDirections[step[0] + "." + step[1]]) {
 362         const [i, j] = [x - step[0], this.getY(y - step[1])];
 363         m.vanish.push(
 364           new PiPo({
 365             x: i,
 366             y: j,
 367             p: this.getPiece(i, j),
 368             c: oppCol
 369           })
 370         );
 371       }
 372     });
 373   }
 374
 375   underAttack([x, y], oppCol) {
 376     // Generate all potential opponent moves, check if king captured.
 377     // TODO: do it more efficiently.
 378     const color = this.getColor(x, y);
 379     for (let i = 0; i < this.size.x; i++) {
 380       for (let j = 0; j < this.size.y; j++) {
 381         if (
 382           this.board[i][j] != "" && this.getColor(i, j) == oppCol &&
 383           this.getPotentialMovesFrom([i, j]).some(m => {
 384             return (
 385               m.vanish.length >= 2 &&
 386               [1, m.vanish.length - 1].some(k => m.vanish[k].p == 'k')
 387             );
 388           })
 389         ) {
 390           return true;
 391         }
 392       }
 393     }
 394     return false;
 395   }
 396
 397 };