+ getPotentialPawnMoves([x, y]) {
+ const color = this.getColor(x, y);
+ let moves = [];
+ const [sizeX, sizeY] = [V.size.x, V.size.y];
+ let shiftX = (color == "w" ? -1 : 1);
+ if (this.subTurn == 2) shiftX *= -1;
+ const firstRank = color == "w" ? sizeX - 1 : 0;
+ const startRank = color == "w" ? sizeX - 2 : 1;
+ const lastRank = color == "w" ? 0 : sizeX - 1;
+
+ // Pawns might be pushed on 1st rank and attempt to move again:
+ if (!V.OnBoard(x + shiftX, y)) return [];
+
+ // A push cannot put a pawn on last rank (it goes backward)
+ let finalPieces = [V.PAWN];
+ if (x + shiftX == lastRank) {
+ // Only allow direction facing inside board:
+ const allowedLancerDirs =
+ lastRank == 0
+ ? ['e', 'f', 'g', 'h', 'm']
+ : ['c', 'd', 'e', 'm', 'o'];
+ finalPieces =
+ allowedLancerDirs
+ .concat([V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN, V.SENTRY, V.JAILER]);
+ }
+ 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: color,
+ p: piece
+ })
+ );
+ }
+ if (
+ // 2-squares jumps forbidden if pawn push
+ this.subTurn == 1 &&
+ [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: only on subTurn == 1
+ const Lep = this.epSquares.length;
+ const epSquare = this.epSquares[Lep - 1];
+ if (
+ this.subTurn == 1 &&
+ !!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;
+ }
+
+ doClick(square) {
+ if (isNaN(square[0])) return null;
+ const L = this.sentryPush.length;
+ const [x, y] = [square[0], square[1]];
+ const color = this.turn;
+ if (
+ this.subTurn == 2 ||
+ this.board[x][y] == V.EMPTY ||
+ this.getPiece(x, y) != V.LANCER ||
+ this.getColor(x, y) != color ||
+ !!this.sentryPush[L-1]
+ ) {
+ return null;
+ }
+ // Stuck lancer?
+ const orientation = this.board[x][y][1];
+ const step = V.LANCER_DIRS[orientation];
+ if (!V.OnBoard(x + step[0], y + step[1])) {
+ let choices = [];
+ Object.keys(V.LANCER_DIRS).forEach(k => {
+ const dir = V.LANCER_DIRS[k];
+ if (
+ (dir[0] != step[0] || dir[1] != step[1]) &&
+ V.OnBoard(x + dir[0], y + dir[1])
+ ) {
+ choices.push(
+ new Move({
+ vanish: [
+ new PiPo({
+ x: x,
+ y: y,
+ c: color,
+ p: orientation
+ })
+ ],
+ appear: [
+ new PiPo({
+ x: x,
+ y: y,
+ c: color,
+ p: k
+ })
+ ],
+ start: { x: x, y : y },
+ end: { x: -1, y: -1 }
+ })
+ );
+ }
+ });
+ return choices;
+ }
+ return null;
+ }
+
+ // Obtain all lancer moves in "step" direction
+ getPotentialLancerMoves_aux([x, y], step, tr) {
+ let moves = [];
+ // Add all moves to vacant squares until opponent is met:
+ const color = this.getColor(x, y);
+ const oppCol =
+ this.subTurn == 1
+ ? V.GetOppCol(color)
+ // at subTurn == 2, consider own pieces as opponent
+ : color;
+ let sq = [x + step[0], y + step[1]];
+ while (V.OnBoard(sq[0], sq[1]) && this.getColor(sq[0], sq[1]) != oppCol) {
+ if (this.board[sq[0]][sq[1]] == V.EMPTY)
+ moves.push(this.getBasicMove([x, y], sq, tr));
+ sq[0] += step[0];
+ sq[1] += step[1];
+ }
+ if (V.OnBoard(sq[0], sq[1]))
+ // Add capturing move
+ moves.push(this.getBasicMove([x, y], sq, tr));
+ return moves;