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;
+ }
+
canIplay(side, [x, y]) {
return side == this.turn && [side, "c"].includes(this.getColor(x, y));
}