-import { ChessRules } from "@/base_rules";
+import { ChessRules, Move, PiPo } from "@/base_rules";
export class DynamoRules extends ChessRules {
- // TODO
+ // TODO: later, allow to push out pawns on a and h files
+ static get HasEnpassant() {
+ return false;
+ }
+
+ canIplay(side, [x, y]) {
+ // Sometimes opponent's pieces can be moved directly
+ return true;
+ }
+
+ setOtherVariables(fen) {
+ super.setOtherVariables(fen);
+ this.subTurn = 1;
+ // Local stack of "action moves"
+ this.amoves = [];
+ const amove = V.ParseFen(fen).amove;
+ if (amove != "-") {
+ const amoveParts = amove.split("/");
+ let amove = {
+ // No need for start & end
+ appear: [],
+ vanish: []
+ };
+ [0, 1].map(i => {
+ amoveParts[i].split(".").forEach(av => {
+ // Format is "bpe3"
+ const xy = V.SquareToCoords(av.substr(2));
+ move[i == 0 ? "appear" : "vanish"].push(
+ new PiPo({
+ x: xy.x,
+ y: xy.y,
+ c: av[0],
+ p: av[1]
+ })
+ );
+ });
+ });
+ this.amoves.push(move);
+ }
+ // Stack "first moves" (on subTurn 1) to merge and check opposite moves
+ this.firstMove = [];
+ }
+
+ static ParseFen(fen) {
+ return Object.assign(
+ ChessRules.ParseFen(fen),
+ { amove: fen.split(" ")[4] }
+ );
+ }
+
+ static IsGoodFen(fen) {
+ if (!ChessRules.IsGoodFen(fen)) return false;
+ const fenParts = fen.split(" ");
+ if (fenParts.length != 6) return false;
+ if (fenParts[5] != "-" && !fenParts[5].match(/^([a-h][1-8]){2}$/))
+ return false;
+ return true;
+ }
+
+ getFen() {
+ return super.getFen() + " " + this.getAmoveFen();
+ }
+
+ getFenForRepeat() {
+ return super.getFenForRepeat() + "_" + this.getAmoveFen();
+ }
+
+ getAmoveFen() {
+ const L = this.amoves.length;
+ return (
+ ["appear","vanish"].map(
+ mpart => {
+ return (
+ this.amoves[L-1][mpart].map(
+ av => {
+ const square = V.CoordsToSquare({ x: av.x, y: av.y });
+ return av.c + av.p + square;
+ }
+ ).join(".")
+ );
+ }
+ ).join("/")
+ );
+ }
+
+ canTake() {
+ // Captures don't occur (only pulls & pushes)
+ return false;
+ }
+
+ // Step is right, just add (push/pull) moves in this direction
+ // Direction is assumed normalized.
+ getMovesInDirection([x, y], [dx, dy], nbSteps) {
+ nbSteps = nbSteps || 8; //max 8 steps anyway
+ let [i, j] = [x + dx, y + dy];
+ let moves = [];
+ const color = this.getColor(x, y);
+ const piece = this.getPiece(x, y);
+ const lastRank = (color == 'w' ? 0 : 7);
+ while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
+ if (i == lastRank && piece == V.PAWN) {
+ // Promotion by push or pull
+ V.PawnSpecs.promotions.forEach(p => {
+ let move = super.getBasicMove([x, y], [i, j], { c: color, p: p });
+ moves.push(move);
+ });
+ }
+ else moves.push(super.getBasicMove([x, y], [i, j]));
+ }
+ if (!V.OnBoard(i, j) && piece != V.KING) {
+ // Add special "exit" move, by "taking king"
+ moves.push(
+ new Move({
+ start: { x: x, y: y },
+ end: JSON.parse(JSON.stringify(this.kingPos[color])),
+ appear: [],
+ vanish: [{ x: x, y: y, c: color, p: piece }]
+ })
+ );
+ }
+ return moves;
+ }
+
+ // Normalize direction to know the step
+ getNormalizedDirection([dx, dy]) {
+ const absDir = [Math.abs(dx), Math.abs(dy)];
+ let divisor = 0;
+ if (absDir[0] != 0 && absDir[1] != 0 && absDir[0] != absDir[1])
+ // Knight
+ divisor = Math.min(absDir[0], absDir[1]);
+ else
+ // Standard slider (or maybe a pawn or king: same)
+ divisor = Math.max(absDir[0], absDir[1]);
+ return [dx / divisor, dy / divisor];
+ }
+
+ // There is something on x2,y2, maybe our color, pushed/pulled
+ static IsAprioriValidMove([x1, y1], [x2, y2]) {
+ const color1 = this.getColor(x1, y1);
+ const color2 = this.getColor(x2, y2);
+ const pawnShift = (color1 == 'w' ? -1 : 1);
+ const pawnStartRank = (color1 == 'w' ? 6 : 1);
+ const deltaX = Math.abs(x1 - x2);
+ const deltaY = Math.abs(y1 - y2);
+ switch (this.getPiece(x1, y1)) {
+ case V.PAWN:
+ return (
+ (
+ color1 == color2 &&
+ y1 == y2 &&
+ (
+ x1 + pawnShift == x2 ||
+ x1 == pawnStartRank && x1 + 2 * pawnShift == x2
+ )
+ )
+ ||
+ (
+ color1 != color2 &&
+ deltaY == 1 &&
+ x1 + pawnShift == x2
+ )
+ );
+ case V.ROOK:
+ return (x1 == x2 || y1 == y2);
+ case V.KNIGHT: {
+ return (deltaX + deltaY == 3 && (deltaX == 1 || deltaY == 1));
+ }
+ case V.BISHOP:
+ return (deltaX == deltaY);
+ case V.QUEEN:
+ return (
+ (deltaX == 0 || deltaY == 0 || deltaX == deltaY)
+ );
+ case V.KING:
+ return (deltaX <= 1 && deltaY <= 1);
+ }
+ return false;
+ }
+
+ // NOTE: for pushes, play the pushed piece first.
+ // for pulls: play the piece doing the action first
+ // NOTE: to push a piece out of the board, make it slide until its king
+ getPotentialMovesFrom([x, y]) {
+ const color = this.turn;
+ if (this.subTurn == 1) {
+ // Free to play any move:
+ const moves = super.getPotentialMovesFrom([x, y])
+ // Structure to avoid adding moves twice (can be action & move)
+ let hashMoves = {};
+ moves.forEach(m => { hashMoves[getMoveHash(m)] = true; });
+ const getMoveHash = (m) => {
+ return V.CoordsToSquare(m.start) + V.CoordsToSquare(m.end);
+ };
+ const addMoves = (dir, nbSteps) => {
+ const newMoves =
+ this.getMovesInDirection([x, y], [-dir[0], -dir[1]], nbSteps)
+ .filter(m => !movesHash[getMoveHash(m)]);
+ newMoves.forEach(m => { hashMoves[getMoveHash(m)] = true; });
+ Array.prototype.push.apply(moves, newMoves);
+ };
+ const pawnShift = (color == 'w' ? -1 : 1);
+ const pawnStartRank = (color == 'w' ? 6 : 1);
+ // [x, y] is pushed by 'color'
+ for (let step of V.steps[V.KNIGHT]) {
+ const [i, j] = [x + step[0], y + step[1]];
+ if (V.OnBoard(i, j) && this.board[i][j] != V.EMPTY) {
+ // Only can move away from a knight (can pull but must move first)
+ Array.prototype.push.apply(
+ moves,
+ this.getMovesInDirection([x, y], [-step[0], -step[1]], 1)
+ .filter(m => !movesHash[getMoveHash(m)])
+ );
+ }
+ }
+ for (let step in V.steps[V.ROOK].concat(V.steps[V.BISHOP])) {
+ let [i, j] = [x + step[0], y + step[1]];
+ while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
+ i += step[0];
+ j += step[1];
+ }
+ if (
+ V.OnBoard(i, j) &&
+ this.board[i][j] != V.EMPTY &&
+ this.getColor(i, j) == color
+ ) {
+ const deltaX = Math.abs(i - x);
+ const deltaY = Math.abs(j - y);
+ // Can a priori go both ways, except with pawns
+ switch (this.getPiece(i, j)) {
+ case V.PAWN:
+ if (deltaX <= 2 && deltaY <= 1) {
+ const pColor = this.getColor(x, y);
+ if (pColor == color && deltaY == 0) {
+ // Pushed forward
+ const maxSteps = (i == pawnStartRank && deltaX == 1 ? 2 : 1);
+ addMoves(step, maxSteps);
+ }
+ else if (pColor != color && deltaY == 1 && deltaX == 1)
+ // Pushed diagonally
+ addMoves(step, 1);
+ }
+ break;
+ case V.ROOK:
+ if (deltaX == 0 || deltaY == 0) addMoves(step);
+ break;
+ case V.KNIGHT:
+ if (deltaX + deltaY == 3 && (deltaX == 1 || deltaY == 1))
+ addMoves(step, 1);
+ break;
+ case V.BISHOP:
+ if (deltaX == deltaY) addMoves(step);
+ break;
+ case V.QUEEN:
+ if (deltaX == 0 || deltaY == 0 || deltaX == deltaY)
+ addMoves(step);
+ break;
+ case V.KING:
+ if (deltaX <= 1 && deltaY <= 1) addMoves(step, 1);
+ break;
+ }
+ }
+ }
+ return moves;
+ }
+ // If subTurn == 2 then we should have a first move,
+ // which restrict what we can play now: only in the first move direction
+ // NOTE: no need for knight or pawn checks, because the move will be
+ // naturally limited in those cases.
+ const L = this.firstMove.length;
+ const fm = this.firstMove[L-1];
+ if (fm.appear.length == 2 && fm.vanish.length == 2)
+ // Castle: no real move playable then.
+ return [];
+ if (fm.appear.length == 0) {
+ // Piece at subTurn 1 just exited the board.
+ // Can I be a piece which caused the exit?
+ this.undo(fm);
+ const moveOk = V.IsAprioriValidMove([x, y], [fm.start.x, fm.start.y]);
+ this.play(fm);
+ if (moveOk) {
+ // Seems so:
+ const dir = this.getNormalizedDirection(
+ [fm.start.x - x, fm.start.y - y]);
+ return this.getMovesInDirection([x, y], dir);
+ }
+ }
+ else {
+ const dirM = this.getNormalizedDirection(
+ [fm.end.x - fm.start.x, fm.end.y - fm.start.y]);
+ const dir = this.getNormalizedDirection(
+ [fm.start.x - x, fm.start.y - y]);
+ // Normalized directions should match:
+ if (dir[0] == dirM[0] && dir[1] == dirM[1])
+ return this.getMovesInDirection([x, y], dir);
+ }
+ return [];
+ }
+
+ // Does m2 un-do m1 ? (to disallow undoing actions)
+ oppositeMoves(m1, m2) {
+ const isEqual = (av1, av2) => {
+ // Precondition: av1 and av2 length = 2
+ for (let av of av1) {
+ const avInAv2 = av2.find(elt => {
+ return (
+ elt.x == av.x &&
+ elt.y == av.y &&
+ elt.c == av.c &&
+ elt.p == av.p
+ );
+ });
+ if (!avInAv2) return false;
+ }
+ return true;
+ };
+ return (
+ m1.appear.length == 2 &&
+ m2.appear.length == 2 &&
+ m1.vanish.length == 2 &&
+ m2.vanish.length == 2 &&
+ isEqual(m1.appear, m2.vanish) &&
+ isEqual(m1.vanish, m2.appear)
+ );
+ }
+
+ getAmove(move1, move2) {
+ // Just merge (one is action one is move, one may be empty)
+ return {
+ appear: move1.appear.concat(move2.appear),
+ vanish: move1.vanish.concat(move2.vanish)
+ }
+ }
+
+ filterValid(moves) {
+ const color = this.turn;
+ if (this.subTurn == 1) {
+ return moves.filter(m => {
+ // A move is valid either if it doesn't result in a check,
+ // or if a second move is possible to counter the check
+ // (not undoing a potential move + action of the opponent)
+ this.play(m);
+ let res = this.underCheck(color);
+ if (res) {
+ const moves2 = this.getAllPotentialMoves();
+ for (m2 of moves2) {
+ this.play(m2);
+ const res2 = this.underCheck(color);
+ this.undo(m2);
+ if (!res2) {
+ res = false;
+ break;
+ }
+ }
+ }
+ this.undo(m);
+ return !res;
+ });
+ }
+ const Lf = this.firstMove.length;
+ const La = this.amoves.length;
+ if (La == 0) return super.filterValid(moves);
+ return (
+ super.filterValid(
+ moves.filter(m => {
+ // Move shouldn't undo another:
+ const amove = this.getAmove(this.firstMove[Lf-1], m);
+ return !this.oppositeMoves(this.amoves[La-1], amove);
+ })
+ )
+ );
+ }
+
+ isAttackedBySlideNJump([x, y], color, 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 &&
+ this.getColor(rx, ry) == color
+ ) {
+ // Now step in the other direction: if end of the world, then attacked
+ 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)) return true;
+ }
+ }
+ return false;
+ }
+
+ isAttackedByPawn([x, y], color) {
+ const lastRank = (color == 'w' ? 0 : 7);
+ if (y != lastRank)
+ // The king can be pushed out by a pawn only on last rank
+ return false;
+ const pawnShift = (color == "w" ? 1 : -1);
+ for (let i of [-1, 1]) {
+ if (
+ y + i >= 0 &&
+ y + i < V.size.y &&
+ this.getPiece(x + pawnShift, y + i) == V.PAWN &&
+ this.getColor(x + pawnShift, y + i) == color
+ ) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ getCurrentScore() {
+ if (this.subTurn == 2)
+ // Move not over
+ return "*";
+ return super.getCurrentScore();
+ }
+
+ doClick(square) {
+ // If subTurn == 2 && square is empty && !underCheck,
+ // then return an empty move, allowing to "pass" subTurn2
+ if (
+ this.subTurn == 2 &&
+ this.board[square.x][square.y] == V.EMPTY &&
+ !this.underCheck(this.turn)
+ ) {
+ return {
+ appear: [],
+ vanish: []
+ };
+ }
+ return null;
+ }
+
+ play(move) {
+ move.flags = JSON.stringify(this.aggregateFlags());
+ V.PlayOnBoard(this.board, move);
+ if (this.subTurn == 2) {
+ this.turn = V.GetOppCol(this.turn);
+ this.movesCount++;
+ }
+ else this.firstMove.push(move);
+ this.subTurn = 3 - this.subTurn;
+ this.postPlay(move);
+ }
+
+ updateCastleFlags(move, piece) {
+ const c = V.GetOppCol(this.turn);
+ const firstRank = (c == "w" ? V.size.x - 1 : 0);
+ // Update castling flags
+ if (piece == V.KING) this.castleFlags[c] = [V.size.y, V.size.y];
+ for (let v of move.vanish) {
+ if (v.x == firstRank && this.castleFlags[c].includes(v.y)) {
+ const flagIdx = (v.y == this.castleFlags[c][0] ? 0 : 1);
+ this.castleFlags[c][flagIdx] = V.size.y;
+ }
+ }
+ }
+
+ undo(move) {
+ this.disaggregateFlags(JSON.parse(move.flags));
+ V.UndoOnBoard(this.board, move);
+ if (this.subTurn == 1) {
+ this.turn = V.GetOppCol(this.turn);
+ this.movesCount--;
+ }
+ else this.firstMove.pop();
+ this.subTurn = 3 - this.subTurn;
+ this.postUndo(move);
+ }
};
projects / vchess.git / blobdiff