-import { ChessRules } from "@/base_rules";
+import { ChessRules, Move, PiPo } from "@/base_rules";
export const VariantRules = class CheckeredRules extends ChessRules {
static board2fen(b) {
super.setOtherVariables(fen);
// Local stack of non-capturing checkered moves:
this.cmoves = [];
- const cmove = fen.split(" ")[5];
+ const cmove = V.ParseFen(fen).cmove;
if (cmove == "-") this.cmoves.push(null);
else {
this.cmoves.push({
static IsGoodFlags(flags) {
// 4 for castle + 16 for pawns
- return !!flags.match(/^[01]{20,20}$/);
+ return !!flags.match(/^[a-z]{4,4}[01]{16,16}$/);
}
setFlags(fenflags) {
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
+ 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";
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 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;
+ }
+
+ // Same as in base_rules but with an array given to isAttacked:
+ getCastleMoves([x, y]) {
+ const c = this.getColor(x, y);
+ if (x != (c == "w" ? V.size.x - 1 : 0) || y != this.INIT_COL_KING[c])
+ return []; //x isn't first rank, or king has moved (shortcut)
+
+ // Castling ?
+ const oppCol = V.GetOppCol(c);
+ let moves = [];
+ let i = 0;
+ // King, then rook:
+ const finalSquares = [
+ [2, 3],
+ [V.size.y - 2, V.size.y - 3]
+ ];
+ castlingCheck: for (
+ let castleSide = 0;
+ castleSide < 2;
+ castleSide++ //large, then small
+ ) {
+ if (this.castleFlags[c][castleSide] >= V.size.y) continue;
+ // If this code is reached, rooks and king are on initial position
+
+ // Nothing on the path of the king ? (and no checks)
+ const finDist = finalSquares[castleSide][0] - y;
+ let step = finDist / Math.max(1, Math.abs(finDist));
+ i = y;
+ do {
+ if (
+ this.isAttacked([x, i], [oppCol]) ||
+ (this.board[x][i] != V.EMPTY &&
+ // NOTE: next check is enough, because of chessboard constraints
+ (this.getColor(x, i) != c ||
+ ![V.KING, V.ROOK].includes(this.getPiece(x, i))))
+ ) {
+ continue castlingCheck;
+ }
+ i += step;
+ } while (i != finalSquares[castleSide][0]);
+
+ // Nothing on the path to the rook?
+ step = castleSide == 0 ? -1 : 1;
+ const rookPos = this.castleFlags[c][castleSide];
+ for (i = y + step; i != rookPos; i += step) {
+ if (this.board[x][i] != V.EMPTY) continue castlingCheck;
+ }
+
+ // Nothing on final squares, except maybe king and castling rook?
+ for (i = 0; i < 2; i++) {
+ if (
+ this.board[x][finalSquares[castleSide][i]] != V.EMPTY &&
+ this.getPiece(x, finalSquares[castleSide][i]) != V.KING &&
+ finalSquares[castleSide][i] != rookPos
+ ) {
+ continue castlingCheck;
+ }
+ }
+
+ // If this code is reached, castle is valid
+ moves.push(
+ new Move({
+ appear: [
+ new PiPo({ x: x, y: finalSquares[castleSide][0], p: V.KING, c: c }),
+ new PiPo({ x: x, y: finalSquares[castleSide][1], p: V.ROOK, c: c })
+ ],
+ vanish: [
+ new PiPo({ x: x, y: y, p: V.KING, c: c }),
+ new PiPo({ x: x, y: rookPos, p: V.ROOK, c: c })
+ ],
+ end:
+ Math.abs(y - rookPos) <= 2
+ ? { x: x, y: rookPos }
+ : { x: x, y: y + 2 * (castleSide == 0 ? -1 : 1) }
+ })
+ );
+ }
+
+ return moves;
+ }
+
canIplay(side, [x, y]) {
return side == this.turn && [side, "c"].includes(this.getColor(x, y));
}
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 checkred pieces
+ // 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) {
return false;
}
+ // colors: array, generally 'w' and 'c' or 'b' and 'c'
+ isAttacked(sq, 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;
+ 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]) {
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"]);
}
return res;
}
- updateVariables(move) {
- super.updateVariables(move);
+ postPlay(move) {
+ super.postPlay(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)
+ 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() {
return evaluation;
}
- static GenRandInitFen() {
- const randFen = ChessRules.GenRandInitFen();
+ static GenRandInitFen(randomness) {
// Add 16 pawns flags + empty cmove:
- return randFen.replace(" w 0 1111", " w 0 11111111111111111111 -");
+ return ChessRules.GenRandInitFen(randomness)
+ .slice(0, -2) + "1111111111111111 - -";
}
static ParseFen(fen) {
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) {