variants/Diamond/class.js

   1 import ChessRules from "/base_rules.js";
   2 import {ArrayFun} from "/utils/array.js";
   3 import {Random} from "/utils/alea.js";
   4
   5 export default class DiamondRules extends ChessRules {
   6
   7   get hasFlags() {
   8     return false;
   9   }
  10
  11   get hasEnpassant() {
  12     return false;
  13   }
  14
  15   getSvgChessboard() {
  16     const diagonal = 10 * this.size.y * Math.sqrt(2);
  17     const halfDiag = 0.5 * diagonal;
  18     const deltaTrans = 10 * this.size.y * (Math.sqrt(2) - 1) / 2;
  19     let board = `
  20       <svg
  21         viewBox="0 0 ${diagonal} ${diagonal}"
  22         class="chessboard_SVG">`;
  23     board += `<g transform="rotate(45 ${halfDiag} ${halfDiag})
  24                  translate(${deltaTrans} ${deltaTrans})">`;
  25     board += this.getBaseSvgChessboard();
  26     board += "</g></svg>";
  27     return board;
  28   }
  29
  30   getPieceWidth(rwidth) {
  31     return (0.95 * rwidth / (Math.sqrt(2) * this.size.y));
  32   }
  33
  34   getPixelPosition(i, j, r) {
  35     if (i < 0 || j < 0 || typeof i == "string")
  36       return super.getPixelPosition(i, j, r);
  37     const sqSize = this.getPieceWidth(r.width) / 0.95;
  38     const flipped = this.flippedBoard;
  39     i = (flipped ? this.size.x - 1 - i : i);
  40     j = (flipped ? this.size.y - 1 - j : j);
  41     const sq2 = Math.sqrt(2);
  42     const shift = [- sqSize / 2, sqSize * (sq2 - 1) / 2];
  43     const x = (j - i) * sqSize / sq2 + shift[0] + r.width / 2;
  44     const y = (i + j) * sqSize / sq2 + shift[1];
  45     return [r.x + x, r.y + y];
  46   }
  47
  48   genRandInitBaseFen() {
  49     if (this.options["randomness"] == 0) {
  50       return {
  51         fen: "krbp4/rqnp4/nbpp4/pppp4/4PPPP/4PPBN/4PNQR/4PBRK",
  52         o: {}
  53       };
  54     }
  55     let pieces = { w: new Array(8), b: new Array(8) };
  56     for (let c of ["w", "b"]) {
  57       if (c == 'b' && options.randomness == 1) {
  58         pieces['b'] = pieces['w'];
  59         break;
  60       }
  61       // Get random squares for every piece, totally freely
  62       let positions = Random.shuffle(ArrayFun.range(8));
  63       const composition = ['b', 'b', 'r', 'r', 'n', 'n', 'k', 'q'];
  64       const rem2 = positions[0] % 2;
  65       if (rem2 == positions[1] % 2) {
  66         // Fix bishops (on different colors)
  67         for (let i=2; i<8; i++) {
  68           if (positions[i] % 2 != rem2) {
  69             [positions[1], positions[i]] = [positions[i], positions[1]];
  70             break;
  71           }
  72         }
  73       }
  74       for (let i = 0; i < 8; i++)
  75         pieces[c][positions[i]] = composition[i];
  76     }
  77     const fen = (
  78       pieces["b"].slice(0, 3).join("") + "p4/" +
  79       pieces["b"].slice(3, 6).join("") + "p4/" +
  80       pieces["b"].slice(6, 8).join("") + "pp4/" +
  81       "pppp4/4PPPP/" +
  82       "4PP" + pieces["w"].slice(6, 8).reverse().join("").toUpperCase() + "/" +
  83       "4P" + pieces["w"].slice(3, 6).reverse().join("").toUpperCase() + "/" +
  84       "4P" + pieces["w"].slice(0, 3).reverse().join("").toUpperCase());
  85     return { fen: fen, o: {} };
  86   }
  87
  88   pieces(color, x, y) {
  89     let res = super.pieces(color, x, y);
  90     const pawnShift = this.getPawnShift(color || 'w');
  91     res['p'].moves = [{steps: [[pawnShift, pawnShift]], range: 1}];
  92     res['p'].attack = [{steps: [[0, pawnShift], [pawnShift, 0]], range: 1}];
  93     return res;
  94   }
  95
  96 };