+import { ChessRules } from "@/base_rules";
+import { ArrayFun } from "@/utils/array";
+import { randInt } from "@/utils/alea";
+
// NOTE: initial setup differs from the original; see
// https://www.chessvariants.com/large.dir/freeling.html
-class GrandRules extends ChessRules
-{
- static getPpath(b)
- {
- return ([V.MARSHALL,V.CARDINAL].includes(b[1]) ? "Grand/" : "") + b;
- }
-
- static IsGoodFen(fen)
- {
- if (!ChessRules.IsGoodFen(fen))
- return false;
- const fenParsed = V.ParseFen(fen);
- // 5) Check captures
- if (!fenParsed.captured || !fenParsed.captured.match(/^[0-9]{14,14}$/))
- return false;
- return true;
- }
-
- static IsGoodEnpassant(enpassant)
- {
- if (enpassant != "-")
- {
- const squares = enpassant.split(",");
- if (squares.length > 2)
- return false;
- for (let sq of squares)
- {
- const ep = V.SquareToCoords(sq);
- if (isNaN(ep.x) || !V.OnBoard(ep))
- return false;
- }
- }
- return true;
- }
-
- static ParseFen(fen)
- {
- const fenParts = fen.split(" ");
- return Object.assign(
- ChessRules.ParseFen(fen),
- { captured: fenParts[5] }
- );
- }
-
- getFen()
- {
- return super.getFen() + " " + this.getCapturedFen();
- }
-
- getCapturedFen()
- {
- let counts = [...Array(14).fill(0)];
- let i = 0;
- for (let j=0; j<V.PIECES.length; j++)
- {
- if (V.PIECES[j] == V.KING) //no king captured
- continue;
- counts[i] = this.captured["w"][V.PIECES[i]];
- counts[7+i] = this.captured["b"][V.PIECES[i]];
- i++;
- }
- return counts.join("");
- }
-
- setOtherVariables(fen)
- {
- super.setOtherVariables(fen);
- const fenParsed = V.ParseFen(fen);
- // Initialize captured pieces' counts from FEN
- this.captured =
- {
- "w":
- {
- [V.PAWN]: parseInt(fenParsed.captured[0]),
- [V.ROOK]: parseInt(fenParsed.captured[1]),
- [V.KNIGHT]: parseInt(fenParsed.captured[2]),
- [V.BISHOP]: parseInt(fenParsed.captured[3]),
- [V.QUEEN]: parseInt(fenParsed.captured[4]),
- [V.MARSHALL]: parseInt(fenParsed.captured[5]),
- [V.CARDINAL]: parseInt(fenParsed.captured[6]),
- },
- "b":
- {
- [V.PAWN]: parseInt(fenParsed.captured[7]),
- [V.ROOK]: parseInt(fenParsed.captured[8]),
- [V.KNIGHT]: parseInt(fenParsed.captured[9]),
- [V.BISHOP]: parseInt(fenParsed.captured[10]),
- [V.QUEEN]: parseInt(fenParsed.captured[11]),
- [V.MARSHALL]: parseInt(fenParsed.captured[12]),
- [V.CARDINAL]: parseInt(fenParsed.captured[13]),
- }
- };
- }
-
- static get size() { return {x:10,y:10}; }
-
- static get MARSHALL() { return 'm'; } //rook+knight
- static get CARDINAL() { return 'c'; } //bishop+knight
-
- static get PIECES()
- {
- return ChessRules.PIECES.concat([V.MARSHALL,V.CARDINAL]);
- }
-
- // There may be 2 enPassant squares (if pawn jump 3 squares)
- getEnpassantFen()
- {
- const L = this.epSquares.length;
- if (!this.epSquares[L-1])
- return "-"; //no en-passant
- let res = "";
- this.epSquares[L-1].forEach(sq => {
- res += V.CoordsToSquare(sq) + ",";
- });
- return res.slice(0,-1); //remove last comma
- }
-
- // En-passant after 2-sq or 3-sq jumps
- getEpSquare(moveOrSquare)
- {
- if (!moveOrSquare)
- return undefined;
- if (typeof moveOrSquare === "string")
- {
- const square = moveOrSquare;
- if (square == "-")
- return undefined;
- let res = [];
- square.split(",").forEach(sq => {
- res.push(V.SquareToCoords(sq));
- });
- return res;
- }
- // Argument is a move:
- const move = moveOrSquare;
- const [sx,sy,ex] = [move.start.x,move.start.y,move.end.x];
- if (this.getPiece(sx,sy) == V.PAWN && Math.abs(sx - ex) >= 2)
- {
- const step = (ex-sx) / Math.abs(ex-sx);
- let res = [{
- x: sx + step,
- y: sy
- }];
- if (sx + 2*step != ex) //3-squares move
- {
- res.push({
- x: sx + 2*step,
- y: sy
- });
- }
- return res;
- }
- return undefined; //default
- }
-
- getPotentialMovesFrom([x,y])
- {
- switch (this.getPiece(x,y))
- {
- case V.MARSHALL:
- return this.getPotentialMarshallMoves([x,y]);
- case V.CARDINAL:
- return this.getPotentialCardinalMoves([x,y]);
- default:
- return super.getPotentialMovesFrom([x,y])
- }
- }
-
- // Special pawn rules: promotions to captured friendly pieces,
- // optional on ranks 8-9 and mandatory on rank 10.
- getPotentialPawnMoves([x,y])
- {
- const color = this.turn;
- let moves = [];
- const [sizeX,sizeY] = [V.size.x,V.size.y];
- const shiftX = (color == "w" ? -1 : 1);
- const startRanks = (color == "w" ? [sizeX-2,sizeX-3] : [1,2]);
- const lastRanks = (color == "w" ? [0,1,2] : [sizeX-1,sizeX-2,sizeX-3]);
- const promotionPieces =
- [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN,V.MARSHALL,V.CARDINAL];
-
- // Always x+shiftX >= 0 && x+shiftX < sizeX, because no pawns on last rank
- let finalPieces = undefined;
- if (lastRanks.includes(x + shiftX))
- {
- finalPieces = promotionPieces.filter(p => this.captured[color][p] > 0);
- if (x + shiftX != lastRanks[0])
- finalPieces.push(V.PAWN);
- }
- else
- finalPieces = [V.PAWN];
- if (this.board[x+shiftX][y] == V.EMPTY)
- {
- // One square forward
- for (let piece of finalPieces)
- moves.push(this.getBasicMove([x,y], [x+shiftX,y], {c:color,p:piece}));
- if (startRanks.includes(x))
- {
- if (this.board[x+2*shiftX][y] == V.EMPTY)
- {
- // Two squares jump
- moves.push(this.getBasicMove([x,y], [x+2*shiftX,y]));
- if (x==startRanks[0] && this.board[x+3*shiftX][y] == V.EMPTY)
- {
- // Three squares jump
- moves.push(this.getBasicMove([x,y], [x+3*shiftX,y]));
- }
- }
- }
- }
- // Captures
- for (let shiftY of [-1,1])
- {
- if (y + shiftY >= 0 && y + shiftY < sizeY
- && this.board[x+shiftX][y+shiftY] != V.EMPTY
- && this.canTake([x,y], [x+shiftX,y+shiftY]))
- {
- for (let piece of finalPieces)
- {
- moves.push(this.getBasicMove([x,y], [x+shiftX,y+shiftY],
- {c:color,p:piece}));
- }
- }
- }
-
- // En passant
- const Lep = this.epSquares.length;
- const epSquare = this.epSquares[Lep-1];
- if (!!epSquare)
- {
- for (let epsq of epSquare)
- {
- // TODO: some redundant checks
- if (epsq.x == x+shiftX && Math.abs(epsq.y - y) == 1)
- {
- var enpassantMove = this.getBasicMove([x,y], [epsq.x,epsq.y]);
- // WARNING: the captured pawn may be diagonally behind us,
- // if it's a 3-squares jump and we take on 1st passing square
- const px = (this.board[x][epsq.y] != V.EMPTY ? x : x - shiftX);
- enpassantMove.vanish.push({
- x: px,
- y: epsq.y,
- p: 'p',
- c: this.getColor(px,epsq.y)
- });
- moves.push(enpassantMove);
- }
- }
- }
-
- return moves;
- }
-
- // TODO: different castle?
-
- getPotentialMarshallMoves(sq)
- {
- return this.getSlideNJumpMoves(sq, V.steps[V.ROOK]).concat(
- this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep"));
- }
-
- getPotentialCardinalMoves(sq)
- {
- return this.getSlideNJumpMoves(sq, V.steps[V.BISHOP]).concat(
- this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep"));
- }
-
- isAttacked(sq, colors)
- {
- return super.isAttacked(sq, colors)
- || this.isAttackedByMarshall(sq, colors)
- || this.isAttackedByCardinal(sq, colors);
- }
-
- isAttackedByMarshall(sq, colors)
- {
- return this.isAttackedBySlideNJump(sq, colors, V.MARSHALL, V.steps[V.ROOK])
- || this.isAttackedBySlideNJump(
- sq, colors, V.MARSHALL, V.steps[V.KNIGHT], "oneStep");
- }
-
- isAttackedByCardinal(sq, colors)
- {
- return this.isAttackedBySlideNJump(sq, colors, V.CARDINAL, V.steps[V.BISHOP])
- || this.isAttackedBySlideNJump(
- sq, colors, V.CARDINAL, V.steps[V.KNIGHT], "oneStep");
- }
-
- updateVariables(move)
- {
- super.updateVariables(move);
- if (move.vanish.length == 2 && move.appear.length == 1)
- {
- // Capture: update this.captured
- this.captured[move.vanish[1].c][move.vanish[1].p]++;
- }
- if (move.vanish[0].p != move.appear[0].p)
- {
- // Promotion: update this.captured
- this.captured[move.vanish[0].c][move.appear[0].p]--;
- }
- }
-
- unupdateVariables(move)
- {
- super.unupdateVariables(move);
- if (move.vanish.length == 2 && move.appear.length == 1)
- this.captured[move.vanish[1].c][move.vanish[1].p]--;
- if (move.vanish[0].p != move.appear[0].p)
- this.captured[move.vanish[0].c][move.appear[0].p]++;
- }
-
- static get VALUES()
- {
- return Object.assign(
- ChessRules.VALUES,
- {'c': 5, 'm': 7} //experimental
- );
- }
-
- static get SEARCH_DEPTH() { return 2; }
-
- // TODO: this function could be generalized and shared better (how ?!...)
- static GenRandInitFen()
- {
- let pieces = { "w": new Array(10), "b": new Array(10) };
- // Shuffle pieces on first and last rank
- for (let c of ["w","b"])
- {
- let positions = range(10);
-
- // Get random squares for bishops
- let randIndex = 2 * randInt(5);
- let bishop1Pos = positions[randIndex];
- // The second bishop must be on a square of different color
- let randIndex_tmp = 2 * randInt(5) + 1;
- let 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 = randInt(8);
- let knight1Pos = positions[randIndex];
- positions.splice(randIndex, 1);
- randIndex = randInt(7);
- let knight2Pos = positions[randIndex];
- positions.splice(randIndex, 1);
-
- // Get random square for queen
- randIndex = randInt(6);
- let queenPos = positions[randIndex];
- positions.splice(randIndex, 1);
-
- // ...random square for marshall
- randIndex = randInt(5);
- let marshallPos = positions[randIndex];
- positions.splice(randIndex, 1);
-
- // ...random square for cardinal
- randIndex = randInt(4);
- let cardinalPos = positions[randIndex];
- positions.splice(randIndex, 1);
-
- // Rooks and king positions are now fixed, because of the ordering rook-king-rook
- let rook1Pos = positions[0];
- let kingPos = positions[1];
- let 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][marshallPos] = 'm';
- pieces[c][cardinalPos] = 'c';
- pieces[c][kingPos] = 'k';
- pieces[c][bishop2Pos] = 'b';
- pieces[c][knight2Pos] = 'n';
- pieces[c][rook2Pos] = 'r';
- }
- return pieces["b"].join("") +
- "/pppppppppp/10/10/10/10/10/10/PPPPPPPPPP/" +
- pieces["w"].join("").toUpperCase() +
- " w 1111 - 00000000000000";
- }
-}
+export const VariantRules = class GrandRules extends ChessRules {
+ static IsGoodFen(fen) {
+ if (!ChessRules.IsGoodFen(fen)) return false;
+ const fenParsed = V.ParseFen(fen);
+ // 5) Check captures
+ if (!fenParsed.captured || !fenParsed.captured.match(/^[0-9]{14,14}$/))
+ return false;
+ return true;
+ }
+
+ static IsGoodEnpassant(enpassant) {
+ if (enpassant != "-") {
+ const squares = enpassant.split(",");
+ if (squares.length > 2) return false;
+ for (let sq of squares) {
+ const ep = V.SquareToCoords(sq);
+ if (isNaN(ep.x) || !V.OnBoard(ep)) return false;
+ }
+ }
+ return true;
+ }
+
+ static ParseFen(fen) {
+ const fenParts = fen.split(" ");
+ return Object.assign(ChessRules.ParseFen(fen), { captured: fenParts[5] });
+ }
+
+ getPpath(b) {
+ return ([V.MARSHALL, V.CARDINAL].includes(b[1]) ? "Grand/" : "") + b;
+ }
+
+ getFen() {
+ return super.getFen() + " " + this.getCapturedFen();
+ }
+
+ getFenForRepeat() {
+ return super.getFenForRepeat() + "_" + this.getCapturedFen();
+ }
+
+ getCapturedFen() {
+ let counts = [...Array(14).fill(0)];
+ let i = 0;
+ for (let j = 0; j < V.PIECES.length; j++) {
+ if (V.PIECES[j] == V.KING)
+ //no king captured
+ continue;
+ counts[i] = this.captured["w"][V.PIECES[i]];
+ counts[7 + i] = this.captured["b"][V.PIECES[i]];
+ i++;
+ }
+ return counts.join("");
+ }
+
+ setOtherVariables(fen) {
+ super.setOtherVariables(fen);
+ const fenParsed = V.ParseFen(fen);
+ // Initialize captured pieces' counts from FEN
+ this.captured = {
+ w: {
+ [V.PAWN]: parseInt(fenParsed.captured[0]),
+ [V.ROOK]: parseInt(fenParsed.captured[1]),
+ [V.KNIGHT]: parseInt(fenParsed.captured[2]),
+ [V.BISHOP]: parseInt(fenParsed.captured[3]),
+ [V.QUEEN]: parseInt(fenParsed.captured[4]),
+ [V.MARSHALL]: parseInt(fenParsed.captured[5]),
+ [V.CARDINAL]: parseInt(fenParsed.captured[6])
+ },
+ b: {
+ [V.PAWN]: parseInt(fenParsed.captured[7]),
+ [V.ROOK]: parseInt(fenParsed.captured[8]),
+ [V.KNIGHT]: parseInt(fenParsed.captured[9]),
+ [V.BISHOP]: parseInt(fenParsed.captured[10]),
+ [V.QUEEN]: parseInt(fenParsed.captured[11]),
+ [V.MARSHALL]: parseInt(fenParsed.captured[12]),
+ [V.CARDINAL]: parseInt(fenParsed.captured[13])
+ }
+ };
+ }
+
+ static get size() {
+ return { x: 10, y: 10 };
+ }
+
+ static get MARSHALL() {
+ return "m";
+ } //rook+knight
+ static get CARDINAL() {
+ return "c";
+ } //bishop+knight
+
+ static get PIECES() {
+ return ChessRules.PIECES.concat([V.MARSHALL, V.CARDINAL]);
+ }
+
+ // There may be 2 enPassant squares (if pawn jump 3 squares)
+ getEnpassantFen() {
+ const L = this.epSquares.length;
+ if (!this.epSquares[L - 1]) return "-"; //no en-passant
+ let res = "";
+ this.epSquares[L - 1].forEach(sq => {
+ res += V.CoordsToSquare(sq) + ",";
+ });
+ return res.slice(0, -1); //remove last comma
+ }
+
+ // En-passant after 2-sq or 3-sq jumps
+ getEpSquare(moveOrSquare) {
+ if (!moveOrSquare) return undefined;
+ if (typeof moveOrSquare === "string") {
+ const square = moveOrSquare;
+ if (square == "-") return undefined;
+ let res = [];
+ square.split(",").forEach(sq => {
+ res.push(V.SquareToCoords(sq));
+ });
+ return res;
+ }
+ // Argument is a move:
+ const move = moveOrSquare;
+ const [sx, sy, ex] = [move.start.x, move.start.y, move.end.x];
+ if (this.getPiece(sx, sy) == V.PAWN && Math.abs(sx - ex) >= 2) {
+ const step = (ex - sx) / Math.abs(ex - sx);
+ let res = [
+ {
+ x: sx + step,
+ y: sy
+ }
+ ];
+ if (sx + 2 * step != ex) {
+ //3-squares move
+ res.push({
+ x: sx + 2 * step,
+ y: sy
+ });
+ }
+ return res;
+ }
+ return undefined; //default
+ }
+
+ getPotentialMovesFrom([x, y]) {
+ switch (this.getPiece(x, y)) {
+ case V.MARSHALL:
+ return this.getPotentialMarshallMoves([x, y]);
+ case V.CARDINAL:
+ return this.getPotentialCardinalMoves([x, y]);
+ default:
+ return super.getPotentialMovesFrom([x, y]);
+ }
+ }
+
+ // Special pawn rules: promotions to captured friendly pieces,
+ // optional on ranks 8-9 and mandatory on rank 10.
+ getPotentialPawnMoves([x, y]) {
+ const color = this.turn;
+ let moves = [];
+ const [sizeX, sizeY] = [V.size.x, V.size.y];
+ const shiftX = color == "w" ? -1 : 1;
+ const startRanks = color == "w" ? [sizeX - 2, sizeX - 3] : [1, 2];
+ const lastRanks =
+ color == "w" ? [0, 1, 2] : [sizeX - 1, sizeX - 2, sizeX - 3];
+ const promotionPieces = [
+ V.ROOK,
+ V.KNIGHT,
+ V.BISHOP,
+ V.QUEEN,
+ V.MARSHALL,
+ V.CARDINAL
+ ];
+
+ // Always x+shiftX >= 0 && x+shiftX < sizeX, because no pawns on last rank
+ let finalPieces = undefined;
+ if (lastRanks.includes(x + shiftX)) {
+ finalPieces = promotionPieces.filter(p => this.captured[color][p] > 0);
+ if (x + shiftX != lastRanks[0]) finalPieces.push(V.PAWN);
+ } else finalPieces = [V.PAWN];
+ if (this.board[x + shiftX][y] == V.EMPTY) {
+ // One square forward
+ for (let piece of finalPieces)
+ moves.push(
+ this.getBasicMove([x, y], [x + shiftX, y], { c: color, p: piece })
+ );
+ if (startRanks.includes(x)) {
+ if (this.board[x + 2 * shiftX][y] == V.EMPTY) {
+ // Two squares jump
+ moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
+ if (x == startRanks[0] && this.board[x + 3 * shiftX][y] == V.EMPTY) {
+ // Three squares jump
+ moves.push(this.getBasicMove([x, y], [x + 3 * shiftX, y]));
+ }
+ }
+ }
+ }
+ // Captures
+ for (let shiftY of [-1, 1]) {
+ if (
+ y + shiftY >= 0 &&
+ y + shiftY < sizeY &&
+ this.board[x + shiftX][y + shiftY] != V.EMPTY &&
+ this.canTake([x, y], [x + shiftX, y + shiftY])
+ ) {
+ for (let piece of finalPieces) {
+ moves.push(
+ this.getBasicMove([x, y], [x + shiftX, y + shiftY], {
+ c: color,
+ p: piece
+ })
+ );
+ }
+ }
+ }
+
+ // En passant
+ const Lep = this.epSquares.length;
+ const epSquare = this.epSquares[Lep - 1];
+ if (epSquare) {
+ for (let epsq of epSquare) {
+ // TODO: some redundant checks
+ if (epsq.x == x + shiftX && Math.abs(epsq.y - y) == 1) {
+ var enpassantMove = this.getBasicMove([x, y], [epsq.x, epsq.y]);
+ // WARNING: the captured pawn may be diagonally behind us,
+ // if it's a 3-squares jump and we take on 1st passing square
+ const px = this.board[x][epsq.y] != V.EMPTY ? x : x - shiftX;
+ enpassantMove.vanish.push({
+ x: px,
+ y: epsq.y,
+ p: "p",
+ c: this.getColor(px, epsq.y)
+ });
+ moves.push(enpassantMove);
+ }
+ }
+ }
+
+ return moves;
+ }
+
+ // TODO: different castle?
+
+ getPotentialMarshallMoves(sq) {
+ return this.getSlideNJumpMoves(sq, V.steps[V.ROOK]).concat(
+ this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep")
+ );
+ }
+
+ getPotentialCardinalMoves(sq) {
+ return this.getSlideNJumpMoves(sq, V.steps[V.BISHOP]).concat(
+ this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep")
+ );
+ }
+
+ isAttacked(sq, colors) {
+ return (
+ super.isAttacked(sq, colors) ||
+ this.isAttackedByMarshall(sq, colors) ||
+ this.isAttackedByCardinal(sq, colors)
+ );
+ }
+
+ isAttackedByMarshall(sq, colors) {
+ return (
+ this.isAttackedBySlideNJump(sq, colors, V.MARSHALL, V.steps[V.ROOK]) ||
+ this.isAttackedBySlideNJump(
+ sq,
+ colors,
+ V.MARSHALL,
+ V.steps[V.KNIGHT],
+ "oneStep"
+ )
+ );
+ }
+
+ isAttackedByCardinal(sq, colors) {
+ return (
+ this.isAttackedBySlideNJump(sq, colors, V.CARDINAL, V.steps[V.BISHOP]) ||
+ this.isAttackedBySlideNJump(
+ sq,
+ colors,
+ V.CARDINAL,
+ V.steps[V.KNIGHT],
+ "oneStep"
+ )
+ );
+ }
+
+ postPlay(move) {
+ super.postPlay(move);
+ if (move.vanish.length == 2 && move.appear.length == 1) {
+ // Capture: update this.captured
+ this.captured[move.vanish[1].c][move.vanish[1].p]++;
+ }
+ if (move.vanish[0].p != move.appear[0].p) {
+ // Promotion: update this.captured
+ this.captured[move.vanish[0].c][move.appear[0].p]--;
+ }
+ }
+
+ postUndo(move) {
+ super.postUndo(move);
+ if (move.vanish.length == 2 && move.appear.length == 1)
+ this.captured[move.vanish[1].c][move.vanish[1].p]--;
+ if (move.vanish[0].p != move.appear[0].p)
+ this.captured[move.vanish[0].c][move.appear[0].p]++;
+ }
+
+ static get VALUES() {
+ return Object.assign(
+ { c: 5, m: 7 }, //experimental
+ ChessRules.VALUES
+ );
+ }
+
+ static get SEARCH_DEPTH() {
+ return 2;
+ }
+
+ static GenRandInitFen(randomness) {
+ if (randomness == 0) {
+ // No castling in the official initial setup
+ return "r8r/1nbqkmcbn1/pppppppppp/10/10/10/10/PPPPPPPPPP/1NBQKMCBN1/R8R " +
+ "w 0 zzzz - 00000000000000";
+ }
+
+ let pieces = { w: new Array(10), b: new Array(10) };
+ // Shuffle pieces on first and last rank
+ for (let c of ["w", "b"]) {
+ if (c == 'b' && randomness == 1) {
+ pieces['b'] = pieces['w'];
+ break;
+ }
+
+ let positions = ArrayFun.range(10);
+
+ // Get random squares for bishops
+ let randIndex = 2 * randInt(5);
+ let bishop1Pos = positions[randIndex];
+ // The second bishop must be on a square of different color
+ let randIndex_tmp = 2 * randInt(5) + 1;
+ let 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 = randInt(8);
+ let knight1Pos = positions[randIndex];
+ positions.splice(randIndex, 1);
+ randIndex = randInt(7);
+ let knight2Pos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ // Get random square for queen
+ randIndex = randInt(6);
+ let queenPos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ // ...random square for marshall
+ randIndex = randInt(5);
+ let marshallPos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ // ...random square for cardinal
+ randIndex = randInt(4);
+ let cardinalPos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ // Rooks and king positions are now fixed, because of the ordering rook-king-rook
+ let rook1Pos = positions[0];
+ let kingPos = positions[1];
+ let 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][marshallPos] = "m";
+ pieces[c][cardinalPos] = "c";
+ pieces[c][kingPos] = "k";
+ pieces[c][bishop2Pos] = "b";
+ pieces[c][knight2Pos] = "n";
+ pieces[c][rook2Pos] = "r";
+ }
+ return (
+ pieces["b"].join("") +
+ "/pppppppppp/10/10/10/10/10/10/PPPPPPPPPP/" +
+ pieces["w"].join("").toUpperCase() +
+ " w 0 1111 - 00000000000000"
+ );
+ }
+};