Better menu ordering ?

[vchess.git] / client / src / variants / Upsidedown.js

import { ChessRules } from "@/base_rules";
import { randInt } from "@/utils/alea";
import { ArrayFun } from "@/utils/array";

export const VariantRules = class UpsidedownRules extends ChessRules
{
  static get HasFlags() { return false; }

  static get HasEnpassant() { return false; }

  getPotentialKingMoves(sq)
  {
    // No castle
    return this.getSlideNJumpMoves(sq,
      V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
  }

  static GenRandInitFen()
  {
    let pieces = { "w": new Array(8), "b": new Array(8) };
    for (let c of ["w","b"])
    {
      let positions = ArrayFun.range(8);

      let randIndex = randInt(8);
      const kingPos = positions[randIndex];
      positions.splice(randIndex, 1);

      // At least a knight must be next to the king:
      let knight1Pos = undefined;
      if (kingPos == 0)
        knight1Pos = 1;
      else if (kingPos == V.size.y-1)
        knight1Pos = V.size.y-2;
      else
        knight1Pos = kingPos + (Math.random() < 0.5 ? 1 : -1);
      // Search for knight1Pos index in positions and remove it
      const knight1Index = positions.indexOf(knight1Pos);
      positions.splice(knight1Index, 1);

      // King+knight1 are on two consecutive squares: one light, one dark
      randIndex = 2 * randInt(3);
      const bishop1Pos = positions[randIndex];
      let randIndex_tmp = 2 * randInt(3) + 1;
      const bishop2Pos = positions[randIndex_tmp];
      positions.splice(Math.max(randIndex,randIndex_tmp), 1);
      positions.splice(Math.min(randIndex,randIndex_tmp), 1);

      randIndex = randInt(4);
      const knight2Pos = positions[randIndex];
      positions.splice(randIndex, 1);

      randIndex = randInt(3);
      const queenPos = positions[randIndex];
      positions.splice(randIndex, 1);

      const rook1Pos = positions[0];
      const rook2Pos = positions[1];

      pieces[c][rook1Pos] = 'r';
      pieces[c][knight1Pos] = 'n';
      pieces[c][bishop1Pos] = 'b';
      pieces[c][queenPos] = 'q';
      pieces[c][kingPos] = 'k';
      pieces[c][bishop2Pos] = 'b';
      pieces[c][knight2Pos] = 'n';
      pieces[c][rook2Pos] = 'r';
    }
    return pieces["w"].join("").toUpperCase() +
      "/PPPPPPPP/8/8/8/8/pppppppp/" +
      pieces["b"].join("") +
      " w 0"; //no castle, no en-passant
  }
}