--- /dev/null
+import { ChessRules, Move, PiPo } from "@/base_rules";
+
+export class Checkered2Rules extends ChessRules {
+ static board2fen(b) {
+ const checkered_codes = {
+ p: "s",
+ q: "t",
+ r: "u",
+ b: "c",
+ n: "o"
+ };
+ if (b[0] == "c") return checkered_codes[b[1]];
+ return ChessRules.board2fen(b);
+ }
+
+ static fen2board(f) {
+ // Tolerate upper-case versions of checkered pieces (why not?)
+ const checkered_pieces = {
+ s: "p",
+ S: "p",
+ t: "q",
+ T: "q",
+ u: "r",
+ U: "r",
+ c: "b",
+ C: "b",
+ o: "n",
+ O: "n"
+ };
+ if (Object.keys(checkered_pieces).includes(f))
+ return "c" + checkered_pieces[f];
+ return ChessRules.fen2board(f);
+ }
+
+ static get PIECES() {
+ return ChessRules.PIECES.concat(["s", "t", "u", "c", "o"]);
+ }
+
+ getPpath(b) {
+ return (b[0] == "c" ? "Checkered/" : "") + b;
+ }
+
+ setOtherVariables(fen) {
+ super.setOtherVariables(fen);
+ // Local stack of non-capturing checkered moves:
+ this.cmoves = [];
+ const cmove = V.ParseFen(fen).cmove;
+ if (cmove == "-") this.cmoves.push(null);
+ else {
+ this.cmoves.push({
+ start: ChessRules.SquareToCoords(cmove.substr(0, 2)),
+ end: ChessRules.SquareToCoords(cmove.substr(2))
+ });
+ }
+ }
+
+ static IsGoodFen(fen) {
+ if (!ChessRules.IsGoodFen(fen)) return false;
+ const fenParts = fen.split(" ");
+ if (fenParts.length != 6) return false;
+ if (fenParts[5] != "-" && !fenParts[5].match(/^([a-h][1-8]){2}$/))
+ return false;
+ return true;
+ }
+
+ static IsGoodFlags(flags) {
+ // 4 for castle + 16 for pawns
+ return !!flags.match(/^[a-z]{4,4}[01]{16,16}$/);
+ }
+
+ setFlags(fenflags) {
+ super.setFlags(fenflags); //castleFlags
+ this.pawnFlags = {
+ w: [...Array(8)], //pawns can move 2 squares?
+ b: [...Array(8)]
+ };
+ const flags = fenflags.substr(4); //skip first 4 letters, for castle
+ for (let c of ["w", "b"]) {
+ for (let i = 0; i < 8; i++)
+ this.pawnFlags[c][i] = flags.charAt((c == "w" ? 0 : 8) + i) == "1";
+ }
+ }
+
+ aggregateFlags() {
+ return [this.castleFlags, this.pawnFlags];
+ }
+
+ disaggregateFlags(flags) {
+ this.castleFlags = flags[0];
+ this.pawnFlags = flags[1];
+ }
+
+ getEpSquare(moveOrSquare) {
+ if (typeof moveOrSquare !== "object" || moveOrSquare.appear[0].c != 'c')
+ return super.getEpSquare(moveOrSquare);
+ // Checkered move: no en-passant
+ return undefined;
+ }
+
+ getCmove(move) {
+ if (move.appear[0].c == "c" && move.vanish.length == 1)
+ return { start: move.start, end: move.end };
+ return null;
+ }
+
+ canTake([x1, y1], [x2, y2]) {
+ const color1 = this.getColor(x1, y1);
+ const color2 = this.getColor(x2, y2);
+ // Checkered aren't captured
+ return (
+ color1 != color2 &&
+ color2 != "c" &&
+ (color1 != "c" || color2 != this.turn)
+ );
+ }
+
+ // Post-processing: apply "checkerization" of standard moves
+ getPotentialMovesFrom([x, y]) {
+ let standardMoves = super.getPotentialMovesFrom([x, y]);
+ const lastRank = this.turn == "w" ? 0 : 7;
+ // King is treated differently: it never turn checkered
+ if (this.getPiece(x, y) == V.KING) return standardMoves;
+ let moves = [];
+ standardMoves.forEach(m => {
+ if (m.vanish[0].p == V.PAWN) {
+ if (
+ Math.abs(m.end.x - m.start.x) == 2 &&
+ !this.pawnFlags[this.turn][m.start.y]
+ ) {
+ return; //skip forbidden 2-squares jumps
+ }
+ if (
+ this.board[m.end.x][m.end.y] == V.EMPTY &&
+ m.vanish.length == 2 &&
+ this.getColor(m.start.x, m.start.y) == "c"
+ ) {
+ return; //checkered pawns cannot take en-passant
+ }
+ }
+ if (m.vanish.length == 1)
+ // No capture
+ moves.push(m);
+ else {
+ // A capture occured (m.vanish.length == 2)
+ m.appear[0].c = "c";
+ moves.push(m);
+ if (
+ // Avoid promotions (already treated):
+ m.appear[0].p != m.vanish[1].p &&
+ (m.vanish[0].p != V.PAWN || m.end.x != lastRank)
+ ) {
+ // Add transformation into captured piece
+ let m2 = JSON.parse(JSON.stringify(m));
+ m2.appear[0].p = m.vanish[1].p;
+ moves.push(m2);
+ }
+ }
+ });
+ return moves;
+ }
+
+ getPotentialPawnMoves([x, y]) {
+ let moves = super.getPotentialPawnMoves([x, y]);
+ // Post-process: set right color for checkered moves
+ if (this.getColor(x, y) == 'c') {
+ moves.forEach(m => {
+ m.appear[0].c = 'c'; //may be done twice if capture
+ m.vanish[0].c = 'c';
+ });
+ }
+ return moves;
+ }
+
+ canIplay(side, [x, y]) {
+ return side == this.turn && [side, "c"].includes(this.getColor(x, y));
+ }
+
+ // Does m2 un-do m1 ? (to disallow undoing checkered moves)
+ oppositeMoves(m1, m2) {
+ return (
+ !!m1 &&
+ m2.appear[0].c == "c" &&
+ m2.appear.length == 1 &&
+ m2.vanish.length == 1 &&
+ m1.start.x == m2.end.x &&
+ m1.end.x == m2.start.x &&
+ m1.start.y == m2.end.y &&
+ m1.end.y == m2.start.y
+ );
+ }
+
+ filterValid(moves) {
+ if (moves.length == 0) return [];
+ const color = this.turn;
+ const L = this.cmoves.length; //at least 1: init from FEN
+ return moves.filter(m => {
+ if (this.oppositeMoves(this.cmoves[L - 1], m)) return false;
+ this.play(m);
+ const res = !this.underCheck(color);
+ this.undo(m);
+ return res;
+ });
+ }
+
+ getAllValidMoves() {
+ const oppCol = V.GetOppCol(this.turn);
+ let potentialMoves = [];
+ for (let i = 0; i < V.size.x; i++) {
+ for (let j = 0; j < V.size.y; j++) {
+ // NOTE: just testing == color isn't enough because of checkered pieces
+ if (this.board[i][j] != V.EMPTY && this.getColor(i, j) != oppCol) {
+ Array.prototype.push.apply(
+ potentialMoves,
+ this.getPotentialMovesFrom([i, j])
+ );
+ }
+ }
+ }
+ return this.filterValid(potentialMoves);
+ }
+
+ atLeastOneMove() {
+ const oppCol = V.GetOppCol(this.turn);
+ for (let i = 0; i < V.size.x; i++) {
+ for (let j = 0; j < V.size.y; j++) {
+ // NOTE: just testing == color isn't enough because of checkered pieces
+ if (this.board[i][j] != V.EMPTY && this.getColor(i, j) != oppCol) {
+ const moves = this.getPotentialMovesFrom([i, j]);
+ if (moves.length > 0) {
+ for (let k = 0; k < moves.length; k++) {
+ if (this.filterValid([moves[k]]).length > 0) return true;
+ }
+ }
+ }
+ }
+ }
+ return false;
+ }
+
+ // colors: array, generally 'w' and 'c' or 'b' and 'c'
+ isAttacked(sq, colors) {
+ if (!Array.isArray(colors)) colors = [colors];
+ return (
+ this.isAttackedByPawn(sq, colors) ||
+ this.isAttackedByRook(sq, colors) ||
+ this.isAttackedByKnight(sq, colors) ||
+ this.isAttackedByBishop(sq, colors) ||
+ this.isAttackedByQueen(sq, colors) ||
+ this.isAttackedByKing(sq, colors)
+ );
+ }
+
+ isAttackedByPawn([x, y], colors) {
+ for (let c of colors) {
+ const color = (c == "c" ? this.turn : c);
+ let pawnShift = color == "w" ? 1 : -1;
+ if (x + pawnShift >= 0 && x + pawnShift < 8) {
+ for (let i of [-1, 1]) {
+ if (
+ y + i >= 0 &&
+ y + i < 8 &&
+ this.getPiece(x + pawnShift, y + i) == V.PAWN &&
+ this.getColor(x + pawnShift, y + i) == c
+ ) {
+ return true;
+ }
+ }
+ }
+ }
+ return false;
+ }
+
+ isAttackedBySlideNJump([x, y], colors, piece, steps, oneStep) {
+ for (let step of steps) {
+ let rx = x + step[0],
+ ry = y + step[1];
+ while (V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && !oneStep) {
+ rx += step[0];
+ ry += step[1];
+ }
+ if (
+ V.OnBoard(rx, ry) &&
+ this.getPiece(rx, ry) === piece &&
+ colors.includes(this.getColor(rx, ry))
+ ) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ isAttackedByRook(sq, colors) {
+ return this.isAttackedBySlideNJump(sq, colors, V.ROOK, V.steps[V.ROOK]);
+ }
+
+ isAttackedByKnight(sq, colors) {
+ return this.isAttackedBySlideNJump(
+ sq,
+ colors,
+ V.KNIGHT,
+ V.steps[V.KNIGHT],
+ "oneStep"
+ );
+ }
+
+ isAttackedByBishop(sq, colors) {
+ return this.isAttackedBySlideNJump(
+ sq, colors, V.BISHOP, V.steps[V.BISHOP]);
+ }
+
+ isAttackedByQueen(sq, colors) {
+ return this.isAttackedBySlideNJump(
+ sq,
+ colors,
+ V.QUEEN,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP])
+ );
+ }
+
+ isAttackedByKing(sq, colors) {
+ return this.isAttackedBySlideNJump(
+ sq,
+ colors,
+ V.KING,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
+ "oneStep"
+ );
+ }
+
+ underCheck(color) {
+ return this.isAttacked(this.kingPos[color], [V.GetOppCol(color), "c"]);
+ }
+
+ getCheckSquares() {
+ const color = this.turn;
+ // Artifically change turn, for checkered pawns
+ this.turn = V.GetOppCol(color);
+ const kingAttacked =
+ this.isAttacked(
+ this.kingPos[color],
+ [this.turn, 'c']
+ );
+ let res = kingAttacked
+ ? [JSON.parse(JSON.stringify(this.kingPos[color]))]
+ : [];
+ this.turn = color;
+ return res;
+ }
+
+ postPlay(move) {
+ super.postPlay(move);
+ // Does this move turn off a 2-squares pawn flag?
+ if ([1, 6].includes(move.start.x) && move.vanish[0].p == V.PAWN)
+ this.pawnFlags[move.start.x == 6 ? "w" : "b"][move.start.y] = false;
+ this.cmoves.push(this.getCmove(move));
+ }
+
+ postUndo(move) {
+ super.postUndo(move);
+ this.cmoves.pop();
+ }
+
+ getCurrentScore() {
+ if (this.atLeastOneMove()) return "*";
+ const color = this.turn;
+ // Artifically change turn, for checkered pawns
+ this.turn = V.GetOppCol(this.turn);
+ const res = this.isAttacked(this.kingPos[color], [V.GetOppCol(color), "c"])
+ ? color == "w"
+ ? "0-1"
+ : "1-0"
+ : "1/2";
+ this.turn = V.GetOppCol(this.turn);
+ return res;
+ }
+
+ evalPosition() {
+ let evaluation = 0;
+ // Just count material for now, considering checkered neutral (...)
+ for (let i = 0; i < V.size.x; i++) {
+ for (let j = 0; j < V.size.y; j++) {
+ if (this.board[i][j] != V.EMPTY) {
+ const sqColor = this.getColor(i, j);
+ if (["w","b"].includes(sqColor)) {
+ const sign = sqColor == "w" ? 1 : -1;
+ evaluation += sign * V.VALUES[this.getPiece(i, j)];
+ }
+ }
+ }
+ }
+ return evaluation;
+ }
+
+ static GenRandInitFen(randomness) {
+ // Add 16 pawns flags + empty cmove:
+ return ChessRules.GenRandInitFen(randomness)
+ .slice(0, -2) + "1111111111111111 - -";
+ }
+
+ static ParseFen(fen) {
+ return Object.assign(
+ ChessRules.ParseFen(fen),
+ { cmove: fen.split(" ")[5] }
+ );
+ }
+
+ getCmoveFen() {
+ const L = this.cmoves.length;
+ return (
+ !this.cmoves[L - 1]
+ ? "-"
+ : ChessRules.CoordsToSquare(this.cmoves[L - 1].start) +
+ ChessRules.CoordsToSquare(this.cmoves[L - 1].end)
+ );
+ }
+
+ getFen() {
+ return super.getFen() + " " + this.getCmoveFen();
+ }
+
+ getFenForRepeat() {
+ return super.getFenForRepeat() + "_" + this.getCmoveFen();
+ }
+
+ getFlagsFen() {
+ let fen = super.getFlagsFen();
+ // Add pawns flags
+ for (let c of ["w", "b"])
+ for (let i = 0; i < 8; i++) fen += (this.pawnFlags[c][i] ? "1" : "0");
+ return fen;
+ }
+
+ static get SEARCH_DEPTH() {
+ return 2;
+ }
+
+ getNotation(move) {
+ if (move.appear.length == 2) {
+ // Castle
+ if (move.end.y < move.start.y) return "0-0-0";
+ return "0-0";
+ }
+
+ const finalSquare = V.CoordsToSquare(move.end);
+ const piece = this.getPiece(move.start.x, move.start.y);
+ let notation = "";
+ if (piece == V.PAWN) {
+ // Pawn move
+ if (move.vanish.length > 1) {
+ // Capture
+ const startColumn = V.CoordToColumn(move.start.y);
+ notation = startColumn + "x" + finalSquare;
+ } else notation = finalSquare;
+ } else {
+ // Piece movement
+ notation =
+ piece.toUpperCase() +
+ (move.vanish.length > 1 ? "x" : "") +
+ finalSquare;
+ }
+ if (move.appear[0].p != move.vanish[0].p)
+ notation += "=" + move.appear[0].p.toUpperCase();
+ return notation;
+ }
+};
projects / vchess.git / blobdiff