+ // TODO: find a more general way to describe pawn movements to avoid
+ // re-writing almost the same function for several variants.
+ getPotentialPawnMoves([x, y]) {
+ const color = this.turn;
+ const piece = this.getPiece(x, y);
+ 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 finalPieces =
+ x + shiftX == lastRank
+ ? piece == V.PAWN
+ ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN]
+ : [V.QUEEN] //hidden queen revealed
+ : piece;
+ if (this.board[x + shiftX][y] == V.EMPTY) {
+ // One square forward
+ for (let p of finalPieces) {
+ moves.push(
+ this.getBasicMove([x, y], [x + shiftX, y], {
+ c: color,
+ p: p
+ })
+ );
+ }
+ 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 p of finalPieces) {
+ moves.push(
+ this.getBasicMove([x, y], [x + shiftX, y + shiftY], {
+ c: color,
+ p: p
+ })
+ );
+ }
+ }
+ }
+
+ if (V.HasEnpassant) {
+ // 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;
+ }
+
projects / vchess.git / commitdiff