-
-let fen, flags = "0707";
- if (!this.options.randomness)
- // Deterministic:
- fen = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR";
-
- else {
- // Randomize
- let pieces = {w: new Array(8), b: new Array(8)};
- flags = "";
- // Shuffle pieces on first (and last rank if randomness == 2)
- for (let c of ["w", "b"]) {
- if (c == 'b' && this.options.randomness == 1) {
- pieces['b'] = pieces['w'];
- flags += flags;
- break;
- }
- let positions = ArrayFun.range(8);
- // Get random squares for bishops
- let randIndex = 2 * Random.randInt(4);
- const bishop1Pos = positions[randIndex];
- // The second bishop must be on a square of different color
- let randIndex_tmp = 2 * Random.randInt(4) + 1;
- const bishop2Pos = positions[randIndex_tmp];
- // Remove chosen squares
- positions.splice(Math.max(randIndex, randIndex_tmp), 1);
- positions.splice(Math.min(randIndex, randIndex_tmp), 1);
- // Get random squares for knights
- randIndex = Random.randInt(6);
- const knight1Pos = positions[randIndex];
- positions.splice(randIndex, 1);
- randIndex = Random.randInt(5);
- const knight2Pos = positions[randIndex];
- positions.splice(randIndex, 1);
- // Get random square for queen
- randIndex = Random.randInt(4);
- const queenPos = positions[randIndex];
- positions.splice(randIndex, 1);
- // Rooks and king positions are now fixed,
- // because of the ordering rook-king-rook
- const rook1Pos = positions[0];
- const kingPos = positions[1];
- const rook2Pos = positions[2];
- // Finally put the shuffled pieces in the board array
- 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";
- flags += rook1Pos.toString() + rook2Pos.toString();
- }
- fen = (
- pieces["b"].join("") +
- "/pppppppp/8/8/8/8/PPPPPPPP/" +
- pieces["w"].join("").toUpperCase()
- );
- }
- return { fen: fen, o: {flags: flags} };