+++ /dev/null
-import { ChessRules } from "@/base_rules";
-
-export const VariantRules = class CheckeredRules 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 = fen.split(" ")[5];
- 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}$/))
- return false;
- return true;
- }
-
- static IsGoodFlags(flags) {
- // 4 for castle + 16 for pawns
- return !!flags.match(/^[01]{20,20}$/);
- }
-
- setFlags(fenflags) {
- super.setFlags(fenflags); //castleFlags
- this.pawnFlags = {
- w: [...Array(8).fill(true)], //pawns can move 2 squares?
- b: [...Array(8).fill(true)]
- };
- const flags = fenflags.substr(4); //skip first 4 digits, 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 has to be treated differently (for castles)
- 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) moves.push(m);
- // No capture
- else {
- // A capture occured (m.vanish.length == 2)
- m.appear[0].c = "c";
- moves.push(m);
- if (
- m.appear[0].p != m.vanish[1].p && //avoid promotions (already treated):
- (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]) {
- const color = this.turn;
- let moves = [];
- const [sizeX, sizeY] = [V.size.x, V.size.y];
- const shiftX = color == "w" ? -1 : 1;
- const startRank = color == "w" ? sizeX - 2 : 1;
- const lastRank = color == "w" ? 0 : sizeX - 1;
- const pawnColor = this.getColor(x, y); //can be checkered
-
- const finalPieces =
- x + shiftX == lastRank
- ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN]
- : [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: pawnColor,
- p: piece
- })
- );
- }
- if (
- x == startRank &&
- this.board[x + 2 * shiftX][y] == V.EMPTY
- ) {
- // Two squares jump
- moves.push(this.getBasicMove([x, y], [x + 2 * 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: pawnColor,
- p: piece
- })
- );
- }
- }
- }
-
- // En passant
- const Lep = this.epSquares.length;
- const epSquare = this.epSquares[Lep - 1]; //always at least one element
- if (
- !!epSquare &&
- epSquare.x == x + shiftX &&
- Math.abs(epSquare.y - y) == 1
- ) {
- let enpassantMove = this.getBasicMove([x, y], [epSquare.x, epSquare.y]);
- enpassantMove.vanish.push({
- x: x,
- y: epSquare.y,
- p: "p",
- c: this.getColor(x, epSquare.y)
- });
- moves.push(enpassantMove);
- }
-
- 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 checkred 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;
- }
-
- 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;
- }
-
- underCheck(color) {
- return this.isAttacked(this.kingPos[color], [V.GetOppCol(color), "c"]);
- }
-
- getCheckSquares(color) {
- // Artifically change turn, for checkered pawns
- this.turn = V.GetOppCol(color);
- const kingAttacked = this.isAttacked(this.kingPos[color], [
- V.GetOppCol(color),
- "c"
- ]);
- let res = kingAttacked
- ? [JSON.parse(JSON.stringify(this.kingPos[color]))] //need to duplicate!
- : [];
- this.turn = color;
- return res;
- }
-
- updateVariables(move) {
- super.updateVariables(move);
- // Does this move turn off a 2-squares pawn flag?
- const secondRank = [1, 6];
- if (secondRank.includes(move.start.x) && move.vanish[0].p == V.PAWN)
- this.pawnFlags[move.start.x == 6 ? "w" : "b"][move.start.y] = false;
- }
-
- getCurrentScore() {
- if (this.atLeastOneMove())
- // game not over
- 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) {
- return ChessRules.GenRandInitFen(randomness)
- // Add 16 pawns flags + empty cmove:
- .replace(" w 0 1111", " w 0 11111111111111111111 -");
- }
-
- static ParseFen(fen) {
- return Object.assign({}, ChessRules.ParseFen(fen), {
- cmove: fen.split(" ")[5]
- });
- }
-
- getFen() {
- const L = this.cmoves.length;
- const cmoveFen = !this.cmoves[L - 1]
- ? "-"
- : ChessRules.CoordsToSquare(this.cmoves[L - 1].start) +
- ChessRules.CoordsToSquare(this.cmoves[L - 1].end);
- return super.getFen() + " " + cmoveFen;
- }
-
- 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;
- }
-
- // TODO (design): this cmove update here or in (un)updateVariables ?
- play(move) {
- this.cmoves.push(this.getCmove(move));
- super.play(move);
- }
-
- undo(move) {
- this.cmoves.pop();
- super.undo(move);
- }
-
- 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";
- }
-
- // Translate final square
- const finalSquare = V.CoordsToSquare(move.end);
-
- const piece = this.getPiece(move.start.x, move.start.y);
- if (piece == V.PAWN) {
- // Pawn move
- let notation = "";
- if (move.vanish.length > 1) {
- // Capture
- const startColumn = V.CoordToColumn(move.start.y);
- notation =
- startColumn +
- "x" +
- finalSquare +
- "=" +
- move.appear[0].p.toUpperCase();
- } //no capture
- else {
- notation = finalSquare;
- if (move.appear.length > 0 && piece != move.appear[0].p)
- //promotion
- notation += "=" + move.appear[0].p.toUpperCase();
- }
- return notation;
- }
- // Piece movement
- return (
- piece.toUpperCase() +
- (move.vanish.length > 1 ? "x" : "") +
- finalSquare +
- (move.vanish.length > 1 ? "=" + move.appear[0].p.toUpperCase() : "")
- );
- }
-};