+// TODO: debug, and forbid self-capture of king.
+
import { ChessRules } from "@/base_rules";
+import { randInt } from "@/utils/alea";
export class SynchroneRules extends ChessRules {
- // TODO: getNotation retourne "?" si turn == "w"
- // ==> byrows disparait, juste "showAll" et "None".
- //
- // play: si turn == "w", enregistrer le coup (whiteMove),
- // mais ne rien faire ==> résolution après le coup noir.
- //
- // ==> un coup sur deux (coups blancs) est "vide" du point de vue de l'exécution.
+ static get CanAnalyze() {
+ return true; //false;
+ }
+
+ static get ShowMoves() {
+ return "byrow";
+ }
+
+ static IsGoodFen(fen) {
+ if (!ChessRules.IsGoodFen(fen)) return false;
+ const fenParsed = V.ParseFen(fen);
+ // 5) Check whiteMove
+ if (
+ (
+ fenParsed.turn == "w" &&
+ // NOTE: do not check really JSON stringified move...
+ (!fenParsed.whiteMove || fenParsed.whiteMove == "-")
+ )
+ ||
+ (fenParsed.turn == "b" && fenParsed.whiteMove != "-")
+ ) {
+ return false;
+ }
+ return true;
+ }
+
+ static IsGoodEnpassant(enpassant) {
+ const epArray = enpassant.split(",");
+ if (![2, 3].includes(epArray.length)) return false;
+ epArray.forEach(epsq => {
+ if (epsq != "-") {
+ const ep = V.SquareToCoords(epsq);
+ if (isNaN(ep.x) || !V.OnBoard(ep)) return false;
+ }
+ });
+ return true;
+ }
+
+ static ParseFen(fen) {
+ const fenParts = fen.split(" ");
+ return Object.assign(
+ ChessRules.ParseFen(fen),
+ { whiteMove: fenParts[5] }
+ );
+ }
+
+ static GenRandInitFen(randomness) {
+ return ChessRules.GenRandInitFen(randomness).slice(0, -1) + "-,- -";
+ }
+
+ getFen() {
+ return super.getFen() + " " + this.getWhitemoveFen();
+ }
+
+ getFenForRepeat() {
+ return super.getFenForRepeat() + "_" + this.getWhitemoveFen();
+ }
+
+ setOtherVariables(fen) {
+ const parsedFen = V.ParseFen(fen);
+ this.setFlags(parsedFen.flags);
+ const epArray = parsedFen.enpassant.split(",");
+ this.epSquares = [];
+ epArray.forEach(epsq => this.epSquares.push(this.getEpSquare(epsq)));
+ super.scanKings(fen);
+ // Also init whiteMove
+ this.whiteMove =
+ parsedFen.whiteMove != "-"
+ ? JSON.parse(parsedFen.whiteMove)
+ : null;
+ }
+
+ // After undo(): no need to re-set INIT_COL_KING
+ scanKings() {
+ this.kingPos = { w: [-1, -1], b: [-1, -1] };
+ for (let i = 0; i < V.size.x; i++) {
+ for (let j = 0; j < V.size.y; j++) {
+ if (this.getPiece(i, j) == V.KING)
+ this.kingPos[this.getColor(i, j)] = [i, j];
+ }
+ }
+ }
+
+ getEnpassantFen() {
+ const L = this.epSquares.length;
+ let res = "";
+ const start = L - 2 - (this.turn == 'b' ? 1 : 0);
+ for (let i=start; i < L; i++) {
+ if (!this.epSquares[i]) res += "-,";
+ else res += V.CoordsToSquare(this.epSquares[i]) + ",";
+ }
+ return res.slice(0, -1);
+ }
+
+ getWhitemoveFen() {
+ if (!this.whiteMove) return "-";
+ return JSON.stringify({
+ start: this.whiteMove.start,
+ end: this.whiteMove.end,
+ appear: this.whiteMove.appear,
+ vanish: this.whiteMove.vanish
+ });
+ }
+
+ // NOTE: lazy unefficient implementation (for now. TODO?)
+ getPossibleMovesFrom([x, y]) {
+ const moves = this.getAllValidMoves();
+ return moves.filter(m => {
+ return m.start.x == x && m.start.y == y;
+ });
+ }
+
+ getCaptures(x, y) {
+ const color = this.turn;
+ const sliderAttack = (xx, yy, allowedSteps) => {
+ const deltaX = xx - x,
+ absDeltaX = Math.abs(deltaX);
+ const deltaY = yy - y,
+ absDeltaY = Math.abs(deltaY);
+ const step = [ deltaX / absDeltaX || 0, deltaY / absDeltaY || 0 ];
+ if (
+ // Check that the step is a priori valid:
+ (absDeltaX != absDeltaY && deltaX != 0 && deltaY != 0) ||
+ allowedSteps.every(st => st[0] != step[0] || st[1] != step[1])
+ ) {
+ return null;
+ }
+ let sq = [ x + step[0], y + step[1] ];
+ while (sq[0] != xx || sq[1] != yy) {
+ // NOTE: no need to check OnBoard in this special case
+ if (this.board[sq[0]][sq[1]] != V.EMPTY) return null;
+ sq[0] += step[0];
+ sq[1] += step[1];
+ }
+ return this.getBasicMove([xx, yy], [x, y]);
+ };
+ // Can I take on the square [x, y] ?
+ // If yes, return the (list of) capturing move(s)
+ let moves = [];
+ for (let i=0; i<8; i++) {
+ for (let j=0; j<8; j++) {
+ if (this.getColor(i, j) == color) {
+ switch (this.getPiece(i, j)) {
+ case V.PAWN: {
+ // Pushed pawns move as enemy pawns
+ const shift = (color == 'w' ? 1 : -1);
+ if (x + shift == i && Math.abs(y - j) == 1)
+ moves.push(this.getBasicMove([i, j], [x, y]));
+ break;
+ }
+ case V.KNIGHT: {
+ const deltaX = Math.abs(i - x);
+ const deltaY = Math.abs(j - y);
+ if (
+ deltaX + deltaY == 3 &&
+ [1, 2].includes(deltaX) &&
+ [1, 2].includes(deltaY)
+ ) {
+ moves.push(this.getBasicMove([i, j], [x, y]));
+ }
+ break;
+ }
+ case V.KING:
+ if (Math.abs(i - x) <= 1 && Math.abs(j - y) <= 1)
+ moves.push(this.getBasicMove([i, j], [x, y]));
+ break;
+ case V.ROOK: {
+ const mv = sliderAttack(i, j, V.steps[V.ROOK]);
+ if (!!mv) moves.push(mv);
+ break;
+ }
+ case V.BISHOP: {
+ const mv = sliderAttack(i, j, V.steps[V.BISHOP]);
+ if (!!mv) moves.push(mv);
+ break;
+ }
+ case V.QUEEN: {
+ const mv = sliderAttack(
+ i, j, V.steps[V.ROOK].concat(V.steps[V.BISHOP]));
+ if (!!mv) moves.push(mv);
+ break;
+ }
+ }
+ }
+ }
+ }
+ return this.filterValid(moves);
+ }
+
+ getAllValidMoves() {
+ const color = this.turn;
+ // 0) Generate our possible moves
+ let myMoves = super.getAllValidMoves();
+ // Lookup table to quickly decide if a move is already in list:
+ let moveSet = {};
+ const getMoveHash = (move) => {
+ return (
+ "m" + move.start.x + move.start.y +
+ move.end.x + move.end.y +
+ // Also use m.appear[0].p for pawn promotions
+ move.appear[0].p
+ );
+ };
+ myMoves.forEach(m => moveSet[getMoveHash(m)] = true);
+ // 1) Generate all opponent's moves
+ this.turn = V.GetOppCol(color);
+ const oppMoves = super.getAllValidMoves();
+ this.turn = color;
+ // 2) Play each opponent's move, and see if captures are possible:
+ // --> capturing moving unit only (otherwise some issues)
+ oppMoves.forEach(m => {
+ V.PlayOnBoard(this.board, m);
+ // Can I take on [m.end.x, m.end.y] ?
+ // If yes and not already in list, add it (without the capturing part)
+ let capturingMoves = this.getCaptures(m.end.x, m.end.y);
+ capturingMoves.forEach(cm => {
+ const cmHash = getMoveHash(cm);
+ if (!moveSet[cmHash]) {
+ // The captured unit hasn't moved yet, so temporarily cancel capture
+ cm.vanish.pop();
+ // If m is itself a capturing move: then replace by self-capture
+ if (m.vanish.length == 2) cm.vanish.push(m.vanish[1]);
+ myMoves.push(cm);
+ moveSet[cmHash] = true;
+ }
+ });
+ V.UndoOnBoard(this.board, m);
+ });
+ return myMoves;
+ }
+
+ filterValid(moves) {
+ if (moves.length == 0) return [];
+ // filterValid can be called when it's "not our turn":
+ const color = moves[0].vanish[0].c;
+ return moves.filter(m => {
+ const piece = m.vanish[0].p;
+ if (piece == V.KING) {
+ this.kingPos[color][0] = m.appear[0].x;
+ this.kingPos[color][1] = m.appear[0].y;
+ }
+ V.PlayOnBoard(this.board, m);
+ let res = !this.underCheck(color);
+ V.UndoOnBoard(this.board, m);
+ if (piece == V.KING) this.kingPos[color] = [m.start.x, m.start.y];
+ return res;
+ });
+ }
+
+ atLeastOneMove(color) {
+ const curTurn = this.turn;
+ this.turn = color;
+ const res = super.atLeastOneMove();
+ this.turn = curTurn;
+ return res;
+ }
+
+ // White and black (partial) moves were played: merge
+ resolveSynchroneMove(move) {
+ const m1 = this.whiteMove;
+ const m2 = move;
+ // For PlayOnBoard (no need for start / end, irrelevant)
+ let smove = {
+ appear: [],
+ vanish: [
+ m1.vanish[0],
+ m2.vanish[0]
+ ]
+ };
+ if ((m1.end.x != m2.end.x) || (m1.end.y != m2.end.y)) {
+ // Easy case: two independant moves (which may (self-)capture)
+ smove.appear.push(m1.appear[0]);
+ smove.appear.push(m2.appear[0]);
+ // "Captured" pieces may have moved:
+ if (
+ m1.vanish.length == 2 &&
+ (
+ m2.end.x != m1.vanish[1].x ||
+ m2.end.y != m1.vanish[1].y
+ )
+ ) {
+ smove.vanish.push(m1.vanish[1]);
+ }
+ if (
+ m2.vanish.length == 2 &&
+ (
+ m1.end.x != m2.vanish[1].x ||
+ m1.end.y != m2.vanish[1].y
+ )
+ ) {
+ smove.vanish.push(m2.vanish[1]);
+ }
+ } else {
+ // Collision:
+ if (m1.vanish.length == 1 && m2.vanish.length == 1) {
+ // Easy case: both disappear except if one is a king
+ const p1 = m1.vanish[0].p;
+ const p2 = m2.vanish[0].p;
+ if ([p1, p2].includes(V.KING)) {
+ smove.appear.push({
+ x: m1.end.x,
+ y: m1.end.y,
+ p: V.KING,
+ c: (p1 == V.KING ? 'w' : 'b')
+ });
+ }
+ } else {
+ // One move is a self-capture and the other a normal capture:
+ // only the self-capture appears
+ console.log(m1);
+ console.log(m2);
+ const selfCaptureMove =
+ m1.vanish[1].c == m1.vanish[0].c
+ ? m1
+ : m2;
+ smove.appear.push({
+ x: m1.end.x,
+ y: m1.end.y,
+ p: selfCaptureMove.appear[0].p,
+ c: selfCaptureMove.vanish[0].c
+ });
+ }
+ }
+ return smove;
+ }
+
+ play(move) {
+ move.flags = JSON.stringify(this.aggregateFlags()); //save flags (for undo)
+ this.epSquares.push(this.getEpSquare(move));
+ // Do not play on board (would reveal the move...)
+ this.turn = V.GetOppCol(this.turn);
+ this.movesCount++;
+ this.postPlay(move);
+ }
+
+ updateCastleFlags(move) {
+ const firstRank = { 'w': V.size.x - 1, 'b': 0 };
+ move.appear.concat(move.vanish).forEach(av => {
+ for (let c of ['w', 'b']) {
+ if (av.x == firstRank[c] && this.castleFlags[c].includes(av.y)) {
+ const flagIdx = (av.y == this.castleFlags[c][0] ? 0 : 1);
+ this.castleFlags[c][flagIdx] = 8;
+ }
+ }
+ });
+ }
+
+ postPlay(move) {
+ if (this.turn == 'b') {
+ // NOTE: whiteMove is used read-only, so no need to copy
+ this.whiteMove = move;
+ return;
+ }
+
+ // A full turn just ended:
+ const smove = this.resolveSynchroneMove(move);
+ V.PlayOnBoard(this.board, smove);
+ this.whiteMove = null;
+
+ // Update king position + flags
+ let kingAppear = { 'w': false, 'b': false };
+ for (let i=0; i<smove.appear.length; i++) {
+ if (smove.appear[i].p == V.KING) {
+ const c = smove.appear[i].c;
+ kingAppear[c] = true;
+ this.kingPos[c][0] = smove.appear[i].x;
+ this.kingPos[c][1] = smove.appear[i].y;
+ }
+ }
+ for (let i=0; i<smove.vanish.length; i++) {
+ if (smove.vanish[i].p == V.KING) {
+ const c = smove.vanish[i].c;
+ if (!kingAppear[c]) {
+ this.kingPos[c][0] = -1;
+ this.kingPos[c][1] = -1;
+ }
+ break;
+ }
+ }
+ this.updateCastleFlags(smove);
+ move.smove = smove;
+ }
+
+ undo(move) {
+ this.epSquares.pop();
+ this.disaggregateFlags(JSON.parse(move.flags));
+ if (this.turn == 'w')
+ // Back to the middle of the move
+ V.UndoOnBoard(this.board, move.smove);
+ this.turn = V.GetOppCol(this.turn);
+ this.movesCount--;
+ this.postUndo(move);
+ }
+
+ postUndo(move) {
+ if (this.turn == 'w')
+ // Reset king positions: scan board
+ this.scanKings();
+ }
+
+ getCheckSquares(color) {
+ if (color == 'b') return [];
+ let res = [];
+ if (this.underCheck('w'))
+ res.push(JSON.parse(JSON.stringify(this.kingPos['w'])));
+ if (this.underCheck('b'))
+ res.push(JSON.parse(JSON.stringify(this.kingPos['b'])));
+ return res;
+ }
+
+ getCurrentScore() {
+ if (this.turn == 'b')
+ // Turn (white + black) not over yet
+ return "*";
+ // Was a king captured?
+ if (this.kingPos['w'][0] < 0) return "0-1";
+ if (this.kingPos['b'][0] < 0) return "1-0";
+ const whiteCanMove = this.atLeastOneMove('w');
+ const blackCanMove = this.atLeastOneMove('b');
+ if (whiteCanMove && blackCanMove) return "*";
+ // Game over
+ const whiteInCheck = this.underCheck('w');
+ const blackInCheck = this.underCheck('b');
+ if (
+ (whiteCanMove && !this.underCheck('b')) ||
+ (blackCanMove && !this.underCheck('w'))
+ ) {
+ return "1/2";
+ }
+ // Checkmate: could be mutual
+ if (!whiteCanMove && !blackCanMove) return "1/2";
+ return (whiteCanMove ? "1-0" : "0-1");
+ }
+
+ getComputerMove() {
+ const maxeval = V.INFINITY;
+ const color = this.turn;
+ let moves = this.getAllValidMoves();
+ if (moves.length == 0)
+ // TODO: this situation should not happen
+ return null;
+
+ if (Math.random() < 0.5)
+ // Return a random move
+ return moves[randInt(moves.length)];
+
+ // Rank moves at depth 1:
+ // try to capture something (not re-capturing)
+ moves.forEach(m => {
+ V.PlayOnBoard(this.board, m);
+ m.eval = this.evalPosition();
+ V.UndoOnBoard(this.board, m);
+ });
+ moves.sort((a, b) => {
+ return (color == "w" ? 1 : -1) * (b.eval - a.eval);
+ });
+ let candidates = [0];
+ for (let i = 1; i < moves.length && moves[i].eval == moves[0].eval; i++)
+ candidates.push(i);
+ return moves[candidates[randInt(candidates.length)]];
+ }
};
projects / vchess.git / blobdiff