import { ChessRules } from "@/base_rules";
import { randInt } from "@/utils/alea";
-export const VariantRules = class MarseilleRules extends ChessRules {
+export class MarseilleRules extends ChessRules {
static IsGoodEnpassant(enpassant) {
- if (enpassant != "-") {
- const squares = enpassant.split(",");
- if (squares.length > 2) return false;
- for (let sq of squares) {
+ const squares = enpassant.split(",");
+ if (squares.length > 2) return false;
+ for (let sq of squares) {
+ if (sq != "-") {
const ep = V.SquareToCoords(sq);
if (isNaN(ep.x) || !V.OnBoard(ep)) return false;
}
// There may be 2 enPassant squares (if 2 pawns jump 2 squares in same turn)
getEnpassantFen() {
- const L = this.epSquares.length;
- if (this.epSquares[L - 1].every(epsq => epsq === undefined)) return "-"; //no en-passant
- let res = "";
- this.epSquares[L - 1].forEach(epsq => {
- if (epsq) res += V.CoordsToSquare(epsq) + ",";
- });
- return res.slice(0, -1); //remove last comma
+ return this.epSquares[this.epSquares.length - 1].map(
+ epsq => epsq === undefined
+ ? "-" //no en-passant
+ : V.CoordsToSquare(epsq)
+ ).join(",");
}
setOtherVariables(fen) {
const parsedFen = V.ParseFen(fen);
this.setFlags(parsedFen.flags);
- if (parsedFen.enpassant == "-") this.epSquares = [[undefined]];
- else {
- let res = [];
- const squares = parsedFen.enpassant.split(",");
- for (let sq of squares) res.push(V.SquareToCoords(sq));
- this.epSquares = [res];
- }
- this.scanKingsRooks(fen);
+ this.epSquares = [parsedFen.enpassant.split(",").map(sq => {
+ if (sq != "-") return V.SquareToCoords(sq);
+ return undefined;
+ })];
+ this.scanKings(fen);
// Extract subTurn from turn indicator: "w" (first move), or
// "w1" or "w2" white subturn 1 or 2, and same for black
const fullTurn = V.ParseFen(fen).turn;
this.turn = fullTurn[0];
- this.subTurn = fullTurn[1] || 0; //"w0" = special code for first move in game
+ // At move 1, the subTurn doesn't need to be specified:
+ this.subTurn = fullTurn[1] || 1;
}
- getPotentialPawnMoves([x, y]) {
- const color = this.turn;
+ getEnpassantCaptures([x, y], shiftX) {
let moves = [];
- const [sizeX, sizeY] = [V.size.x, V.size.y];
- const shiftX = color == "w" ? -1 : 1;
- const firstRank = color == "w" ? sizeX - 1 : 0;
- const startRank = color == "w" ? sizeX - 2 : 1;
- const lastRank = color == "w" ? 0 : sizeX - 1;
- const finalPieces =
- x + shiftX == lastRank ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN] : [V.PAWN];
-
- // One square forward
- if (this.board[x + shiftX][y] == V.EMPTY) {
- for (let piece of finalPieces) {
- moves.push(
- this.getBasicMove([x, y], [x + shiftX, y], { c: color, p: piece })
- );
- }
- // Next condition because pawns on 1st rank can generally jump
- if (
- [startRank, firstRank].includes(x) &&
- 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: color,
- p: piece
- })
- );
- }
- }
- }
-
// En passant: always OK if subturn 1,
// OK on subturn 2 only if enPassant was played at subturn 1
// (and if there are two e.p. squares available).
if (sq) epSqs.push(sq);
});
if (epSqs.length == 0) return moves;
- const oppCol = V.GetOppCol(color);
+ const oppCol = V.GetOppCol(this.getColor(x, y));
for (let sq of epSqs) {
if (
this.subTurn == 1 ||
}
}
}
-
return moves;
}
move.turn = this.turn + this.subTurn;
V.PlayOnBoard(this.board, move);
const epSq = this.getEpSquare(move);
- if (this.subTurn == 0) {
- //first move in game
+ if (this.movesCount == 0) {
+ // First move in game
this.turn = "b";
- this.subTurn = 1;
this.epSquares.push([epSq]);
+ this.movesCount = 1;
}
// Does this move give check on subturn 1? If yes, skip subturn 2
else if (this.subTurn == 1 && this.underCheck(V.GetOppCol(this.turn))) {
this.turn = V.GetOppCol(this.turn);
this.epSquares.push([epSq]);
move.checkOnSubturn1 = true;
+ this.movesCount++;
} else {
if (this.subTurn == 2) {
this.turn = V.GetOppCol(this.turn);
let lastEpsq = this.epSquares[this.epSquares.length - 1];
lastEpsq.push(epSq);
- } else this.epSquares.push([epSq]);
+ } else {
+ this.epSquares.push([epSq]);
+ this.movesCount++;
+ }
this.subTurn = 3 - this.subTurn;
}
- this.updateVariables(move);
+ this.postPlay(move);
+ }
+
+ postPlay(move) {
+ const c = move.turn.charAt(0);
+ const piece = move.vanish[0].p;
+ const firstRank = c == "w" ? V.size.x - 1 : 0;
+
+ if (piece == V.KING && move.appear.length > 0) {
+ this.kingPos[c][0] = move.appear[0].x;
+ this.kingPos[c][1] = move.appear[0].y;
+ this.castleFlags[c] = [V.size.y, V.size.y];
+ return;
+ }
+ const oppCol = V.GetOppCol(c);
+ const oppFirstRank = V.size.x - 1 - firstRank;
+ if (
+ move.start.x == firstRank && //our rook moves?
+ this.castleFlags[c].includes(move.start.y)
+ ) {
+ const flagIdx = (move.start.y == this.castleFlags[c][0] ? 0 : 1);
+ this.castleFlags[c][flagIdx] = V.size.y;
+ } else if (
+ move.end.x == oppFirstRank && //we took opponent rook?
+ this.castleFlags[oppCol].includes(move.end.y)
+ ) {
+ const flagIdx = (move.end.y == this.castleFlags[oppCol][0] ? 0 : 1);
+ this.castleFlags[oppCol][flagIdx] = V.size.y;
+ }
}
undo(move) {
this.disaggregateFlags(JSON.parse(move.flags));
V.UndoOnBoard(this.board, move);
- if (move.turn[1] == "0" || move.checkOnSubturn1 || this.subTurn == 2)
+ if (this.movesCount == 1 || !!move.checkOnSubturn1 || this.subTurn == 2) {
+ // The move may not be full, but is fully undone:
this.epSquares.pop();
- //this.subTurn == 1
- else {
+ // Moves counter was just incremented:
+ this.movesCount--;
+ } else {
+ // Undo the second half of a move
let lastEpsq = this.epSquares[this.epSquares.length - 1];
lastEpsq.pop();
}
this.turn = move.turn[0];
this.subTurn = parseInt(move.turn[1]);
- this.unupdateVariables(move);
+ super.postUndo(move);
}
// NOTE: GenRandInitFen() is OK,
// No alpha-beta here, just adapted min-max at depth 2(+1)
getComputerMove() {
- if (this.subTurn == 2) return null; //TODO: imperfect interface setup
-
const maxeval = V.INFINITY;
const color = this.turn;
const oppCol = V.GetOppCol(this.turn);