import { ArrayFun } from "@/utils/array";
-import { randInt, shuffle } from "@/utils/alea";
+import { randInt } from "@/utils/alea";
import { ChessRules, PiPo, Move } from "@/base_rules";
export const VariantRules = class EightpiecesRules extends ChessRules {
return ChessRules.PIECES.concat([V.JAILER, V.SENTRY, V.LANCER]);
}
+ // Lancer directions *from white perspective*
static get LANCER_DIRS() {
return {
'c': [-1, 0], //north
super.setOtherVariables(fen);
// subTurn == 2 only when a sentry moved, and is about to push something
this.subTurn = 1;
+ // Sentry position just after a "capture" (subTurn from 1 to 2)
+ this.sentryPos = null;
// Stack pieces' forbidden squares after a sentry move at each turn
const parsedFen = V.ParseFen(fen);
if (parsedFen.sentrypush == "-") this.sentryPush = [null];
}
}
- canTake([x1,y1], [x2, y2]) {
- if (this.subTurn == 2)
- // Sentry push: pieces can capture own color (only)
- return this.getColor(x1, y1) == this.getColor(x2, y2);
- return super.canTake([x1,y1], [x2, y2]);
- }
-
static GenRandInitFen(randomness) {
- // TODO: special conditions for 960
- return "jsfqkbnr/pppppppp/8/8/8/8/PPPPPPPP/JSDQKBNR w 0 1111 - -";
+ if (randomness == 0)
+ // Deterministic:
+ return "jsfqkbnr/pppppppp/8/8/8/8/PPPPPPPP/JSDQKBNR w 0 1111 - -";
+
+ let pieces = { w: new Array(8), b: new Array(8) };
+ // Shuffle pieces on first (and last rank if randomness == 2)
+ for (let c of ["w", "b"]) {
+ if (c == 'b' && randomness == 1) {
+ const lancerIdx = pieces['w'].findIndex(p => {
+ return Object.keys(V.LANCER_DIRS).includes(p);
+ });
+ pieces['b'] =
+ pieces['w'].slice(0, lancerIdx)
+ .concat(['g'])
+ .concat(pieces['w'].slice(lancerIdx + 1));
+ break;
+ }
+
+ let positions = ArrayFun.range(8);
+
+ // Get random squares for bishop and sentry
+ let randIndex = 2 * randInt(4);
+ let bishopPos = positions[randIndex];
+ // The sentry must be on a square of different color
+ let randIndex_tmp = 2 * randInt(4) + 1;
+ let sentryPos = positions[randIndex_tmp];
+ if (c == 'b') {
+ // Check if white sentry is on the same color as ours.
+ // If yes: swap bishop and sentry positions.
+ if ((pieces['w'].indexOf('s') - sentryPos) % 2 == 0)
+ [bishopPos, sentryPos] = [sentryPos, bishopPos];
+ }
+ positions.splice(Math.max(randIndex, randIndex_tmp), 1);
+ positions.splice(Math.min(randIndex, randIndex_tmp), 1);
+
+ // Get random squares for knight and lancer
+ randIndex = randInt(6);
+ const knightPos = positions[randIndex];
+ positions.splice(randIndex, 1);
+ randIndex = randInt(5);
+ const lancerPos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ // Get random square for queen
+ randIndex = randInt(4);
+ const queenPos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ // Rook, jailer and king positions are now almost fixed,
+ // only the ordering rook-> jailer or jailer->rook must be decided.
+ let rookPos = positions[0];
+ let jailerPos = positions[2];
+ const kingPos = positions[1];
+ if (Math.random() < 0.5) [rookPos, jailerPos] = [jailerPos, rookPos];
+
+ pieces[c][rookPos] = "r";
+ pieces[c][knightPos] = "n";
+ pieces[c][bishopPos] = "b";
+ pieces[c][queenPos] = "q";
+ pieces[c][kingPos] = "k";
+ pieces[c][sentryPos] = "s";
+ // Lancer faces north for white, and south for black:
+ pieces[c][lancerPos] = c == 'w' ? 'c' : 'g';
+ pieces[c][jailerPos] = "j";
+ }
+ return (
+ pieces["b"].join("") +
+ "/pppppppp/8/8/8/8/PPPPPPPP/" +
+ pieces["w"].join("").toUpperCase() +
+ " w 0 1111 - -"
+ );
}
// Scan kings, rooks and jailers
this.board[i][j] != V.EMPTY &&
this.getColor(i, j) == oppCol
) {
- const oppPiece = this.getPiece(i, j);
- if (oppPiece == V.JAILER) return [i, j];
+ if (this.getPiece(i, j) == V.JAILER) return [i, j];
}
}
return null;
}
- getPotentialMovesFrom_aux([x, y]) {
- switch (this.getPiece(x, y)) {
- case V.JAILER:
- return this.getPotentialJailerMoves([x, y]);
- case V.SENTRY:
- return this.getPotentialSentryMoves([x, y]);
- case V.LANCER
- return this.getPotentialLancerMoves([x, y]);
- default:
- return super.getPotentialMovesFrom([x, y]);
- }
- }
+ // Because of the lancers, getPiece() could be wrong:
+ // use board[x][y][1] instead (always valid).
+ getBasicMove([sx, sy], [ex, ey], tr) {
+ let mv = new Move({
+ appear: [
+ new PiPo({
+ x: ex,
+ y: ey,
+ c: tr ? tr.c : this.getColor(sx, sy),
+ p: tr ? tr.p : this.board[sx][sy].charAt(1)
+ })
+ ],
+ vanish: [
+ new PiPo({
+ x: sx,
+ y: sy,
+ c: this.getColor(sx, sy),
+ p: this.board[sx][sy].charAt(1)
+ })
+ ]
+ });
- getPotentialMovesFrom([x,y]) {
- if (this.subTurn == 1) {
- if (!!this.isImmobilized([x, y])) return [];
- return this.getPotentialMovesFrom_aux([x, y]);
+ // The opponent piece disappears if we take it
+ if (this.board[ex][ey] != V.EMPTY) {
+ mv.vanish.push(
+ new PiPo({
+ x: ex,
+ y: ey,
+ c: this.getColor(ex, ey),
+ p: this.board[ex][ey].charAt(1)
+ })
+ );
}
- // subTurn == 2: only the piece pushed by the sentry is allowed to move,
- // as if the sentry didn't exist
- if (x != this.sentryPos.x && y != this.sentryPos.y) return [];
- return this.getPotentialMovesFrom_aux([x,y]);
+
+ return mv;
}
- getAllValidMoves() {
- let moves = super.getAllValidMoves().filter(m =>
- // Remove jailer captures
- m.vanish[0].p != V.JAILER || m.vanish.length == 1;
+ canIplay(side, [x, y]) {
+ return (
+ (this.subTurn == 1 && this.turn == side && this.getColor(x, y) == side) ||
+ (this.subTurn == 2 && x == this.sentryPos.x && y == this.sentryPos.y)
);
+ }
+
+ getPotentialMovesFrom([x,y]) {
+ // At subTurn == 2, jailers aren't effective (Jeff K)
+ if (this.subTurn == 1 && !!this.isImmobilized([x, y])) return [];
+ if (this.subTurn == 2) {
+ // Temporarily change pushed piece color.
+ // (Not using getPiece() because of lancers)
+ var oppCol = this.getColor(x, y);
+ var color = V.GetOppCol(oppCol);
+ var saveXYstate = this.board[x][y];
+ this.board[x][y] = color + this.board[x][y].charAt(1);
+ }
+ let moves = [];
+ switch (this.getPiece(x, y)) {
+ case V.JAILER:
+ moves = this.getPotentialJailerMoves([x, y]);
+ break;
+ case V.SENTRY:
+ moves = this.getPotentialSentryMoves([x, y]);
+ break;
+ case V.LANCER:
+ moves = this.getPotentialLancerMoves([x, y]);
+ break;
+ default:
+ moves = super.getPotentialMovesFrom([x, y]);
+ break;
+ }
const L = this.sentryPush.length;
- if (!!this.sentryPush[L-1] && this.subTurn == 1) {
+ if (!!this.sentryPush[L-1]) {
// Delete moves walking back on sentry push path
moves = moves.filter(m => {
if (
return true;
});
}
+ else if (this.subTurn == 2) {
+ // Don't forget to re-add the sentry on the board:
+ // Also fix color of pushed piece afterward:
+ moves.forEach(m => {
+ m.appear.push({x: x, y: y, p: V.SENTRY, c: color});
+ m.appear[0].c = oppCol;
+ m.vanish[0].c = oppCol;
+ });
+ }
return moves;
}
- filterValid(moves) {
- // Disable check tests when subTurn == 2, because the move isn't finished
- if (this.subTurn == 2) return moves;
- return super.filterValid(moves);
+ getPotentialPawnMoves([x, y]) {
+ const color = this.getColor(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 =
+ // No promotions after pushes!
+ x + shiftX == lastRank && this.subTurn == 1
+ ?
+ Object.keys(V.LANCER_DIRS).concat(
+ [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN, V.SENTRY, V.JAILER])
+ : [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: color,
+ 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: color,
+ 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;
+ }
+
+ // Obtain all lancer moves in "step" direction,
+ // without final re-orientation.
+ getPotentialLancerMoves_aux([x, y], step, tr) {
+ let moves = [];
+ // Add all moves to vacant squares until opponent is met:
+ const oppCol = V.GetOppCol(this.getColor(x, y));
+ 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;
}
getPotentialLancerMoves([x, y]) {
- // TODO: add all lancer possible orientations same as pawn promotions,
- // except if just after a push: allow all movements from init square then
- return [];
+ let moves = [];
+ // Add all lancer possible orientations, similar to pawn promotions.
+ // Except if just after a push: allow all movements from init square then
+ const L = this.sentryPush.length;
+ if (!!this.sentryPush[L-1]) {
+ // Maybe I was pushed
+ const pl = this.sentryPush[L-1].length;
+ if (
+ this.sentryPush[L-1][pl-1].x == x &&
+ this.sentryPush[L-1][pl-1].y == y
+ ) {
+ // I was pushed: allow all directions (for this move only), but
+ // do not change direction after moving.
+ const color = this.getColor(x, y);
+ Object.values(V.LANCER_DIRS).forEach(step => {
+ const dirCode = Object.keys(V.LANCER_DIRS).find(k => {
+ return (V.LANCER_DIRS[k][0] == step[0] && V.LANCER_DIRS[k][1] == step[1]);
+ });
+ Array.prototype.push.apply(
+ moves,
+ this.getPotentialLancerMoves_aux([x, y], step, { p: dirCode, c: color })
+ );
+ });
+ return moves;
+ }
+ }
+ // I wasn't pushed: standard lancer move
+ const dirCode = this.board[x][y][1];
+ const monodirMoves =
+ this.getPotentialLancerMoves_aux([x, y], V.LANCER_DIRS[dirCode]);
+ // Add all possible orientations aftermove except if I'm being pushed
+ if (this.subTurn == 1) {
+ monodirMoves.forEach(m => {
+ Object.keys(V.LANCER_DIRS).forEach(k => {
+ let mk = JSON.parse(JSON.stringify(m));
+ mk.appear[0].p = k;
+ moves.push(mk);
+ });
+ });
+ return moves;
+ } else return monodirMoves;
}
getPotentialSentryMoves([x, y]) {
// The sentry moves a priori like a bishop:
let moves = super.getPotentialBishopMoves([x, y]);
- // ...but captures are replaced by special move
- // "appear = [], vanish = init square" to let the pushed piece move then.
- // TODO
+ // ...but captures are replaced by special move, if and only if
+ // "captured" piece can move now, considered as the capturer unit.
+ // --> except is subTurn == 2, in this case I don't push anything.
+ if (this.subTurn == 2) return moves.filter(m => m.vanish.length == 1);
+ moves.forEach(m => {
+ if (m.vanish.length == 2) {
+ // Temporarily cancel the sentry capture:
+ m.appear.pop();
+ m.vanish.pop();
+ }
+ });
+ // Can the pushed unit make any move? ...resulting in a non-self-check?
+ const color = this.getColor(x, y);
+ const fMoves = moves.filter(m => {
+ // Sentry push?
+ if (m.appear.length == 0) {
+ let res = false;
+ this.play(m);
+ let moves2 = this.filterValid(
+ this.getPotentialMovesFrom([m.end.x, m.end.y]));
+ for (let m2 of moves2) {
+ this.play(m2);
+ res = !this.underCheck(color);
+ this.undo(m2);
+ if (res) break;
+ }
+ this.undo(m);
+ return res;
+ }
+ return true;
+ });
+ return fMoves;
}
getPotentialJailerMoves([x, y]) {
- // Captures are removed afterward:
- return super.getPotentialRookMoves([x, y]);
+ return super.getPotentialRookMoves([x, y]).filter(m => {
+ // Remove jailer captures
+ return m.vanish[0].p != V.JAILER || m.vanish.length == 1;
+ });
}
getPotentialKingMoves([x, y]) {
// Augment with pass move is the king is immobilized:
const jsq = this.isImmobilized([x, y]);
if (!!jsq) {
- moves.push(new Move({
- appear: [],
- vanish: [],
- start: { x: x, y: y },
- end: { x: jsq[0], y: jsq[1] }
- });
+ moves.push(
+ new Move({
+ appear: [],
+ vanish: [],
+ start: { x: x, y: y },
+ end: { x: jsq[0], y: jsq[1] }
+ })
+ );
}
return moves;
}
return moves;
}
+ filterValid(moves) {
+ // Disable check tests for sentry pushes,
+ // because in this case the move isn't finished
+ let movesWithoutSentryPushes = [];
+ let movesWithSentryPushes = [];
+ moves.forEach(m => {
+ if (m.appear.length > 0) movesWithoutSentryPushes.push(m);
+ else movesWithSentryPushes.push(m);
+ });
+ const filteredMoves = super.filterValid(movesWithoutSentryPushes);
+ // If at least one full move made, everything is allowed:
+ if (this.movesCount >= 2)
+ return filteredMoves.concat(movesWithSentryPushes);
+ // Else, forbid checks and captures:
+ const oppCol = V.GetOppCol(this.turn);
+ return filteredMoves.filter(m => {
+ if (m.vanish.length == 2 && m.appear.length == 1) return false;
+ this.play(m);
+ const res = !this.underCheck(oppCol);
+ this.undo(m);
+ return res;
+ }).concat(movesWithSentryPushes);
+ }
+
+ getAllValidMoves() {
+ if (this.subTurn == 1) return super.getAllValidMoves();
+ // Sentry push:
+ const sentrySq = [this.sentryPos.x, this.sentryPos.y];
+ return this.filterValid(this.getPotentialMovesFrom(sentrySq));
+ }
+
updateVariables(move) {
- super.updateVariables(move);
- if (this.subTurn == 2) {
- // A piece is pushed:
- // TODO: push array of squares between start and end of move, included
- // (except if it's a pawn)
- this.sentryPush.push([]); //TODO
- this.subTurn = 1;
- } else {
- if (move.appear.length == 0 && move.vanish.length == 1) {
- // Special sentry move: subTurn <- 2, and then move pushed piece
- this.subTurn = 2;
- }
- // Else: normal move.
+ const c = this.turn;
+ const piece = move.vanish[0].p;
+ const firstRank = (c == "w" ? V.size.x - 1 : 0);
+
+ // Update king position + flags
+ if (piece == V.KING) {
+ this.kingPos[c][0] = move.appear[0].x;
+ this.kingPos[c][1] = move.appear[0].y;
+ this.castleFlags[c] = [false, false];
+ return;
}
+
+ // Update castling flags if rook or jailer moved (or is captured)
+ const oppCol = V.GetOppCol(c);
+ const oppFirstRank = V.size.x - 1 - firstRank;
+ let flagIdx = 0;
+ if (
+ // Our rook moves?
+ move.start.x == firstRank &&
+ this.INIT_COL_ROOK[c] == move.start.y
+ ) {
+ if (this.INIT_COL_ROOK[c] > this.INIT_COL_JAILER[c]) flagIdx++;
+ this.castleFlags[c][flagIdx] = false;
+ } else if (
+ // Our jailer moves?
+ move.start.x == firstRank &&
+ this.INIT_COL_JAILER[c] == move.start.y
+ ) {
+ if (this.INIT_COL_JAILER[c] > this.INIT_COL_ROOK[c]) flagIdx++;
+ this.castleFlags[c][flagIdx] = false;
+ } else if (
+ // We took opponent's rook?
+ move.end.x == oppFirstRank &&
+ this.INIT_COL_ROOK[oppCol] == move.end.y
+ ) {
+ if (this.INIT_COL_ROOK[oppCol] > this.INIT_COL_JAILER[oppCol]) flagIdx++;
+ this.castleFlags[oppCol][flagIdx] = false;
+ } else if (
+ // We took opponent's jailer?
+ move.end.x == oppFirstRank &&
+ this.INIT_COL_JAILER[oppCol] == move.end.y
+ ) {
+ if (this.INIT_COL_JAILER[oppCol] > this.INIT_COL_ROOK[oppCol]) flagIdx++;
+ this.castleFlags[oppCol][flagIdx] = false;
+ }
+
+ if (move.appear.length == 0 && move.vanish.length == 1) {
+ // The sentry is about to push a piece: subTurn goes from 1 to 2
+ this.sentryPos = { x: move.end.x, y: move.end.y };
+ } else if (this.subTurn == 2) {
+ // A piece is pushed: forbid array of squares between start and end
+ // of move, included (except if it's a pawn)
+ let squares = [];
+ if (move.vanish[0].p != V.PAWN) {
+ if ([V.KNIGHT,V.KING].includes(move.vanish[0].p))
+ // short-range pieces: just forbid initial square
+ squares.push(move.start);
+ else {
+ const deltaX = move.end.x - move.start.x;
+ const deltaY = move.end.y - move.start.y;
+ const step = [
+ deltaX / Math.abs(deltaX) || 0,
+ deltaY / Math.abs(deltaY) || 0
+ ];
+ for (
+ let sq = {x: move.start.x, y: move.start.y};
+ sq.x != move.end.x && sq.y != move.end.y;
+ sq.x += step[0], sq.y += step[1]
+ ) {
+ squares.push(sq);
+ }
+ }
+ // Add end square as well, to know if I was pushed (useful for lancers)
+ squares.push(move.end);
+ }
+ this.sentryPush.push(squares);
+ } else this.sentryPush.push(null);
+ }
+
+ // TODO: cleaner (global) update/unupdate variables logic, rename...
+ unupdateVariables(move) {
+ super.unupdateVariables(move);
+ this.sentryPush.pop();
}
play(move) {
move.flags = JSON.stringify(this.aggregateFlags());
this.epSquares.push(this.getEpSquare(move));
V.PlayOnBoard(this.board, move);
- // TODO: turn changes only if not a sentry push or subTurn == 2
- //this.turn = V.GetOppCol(this.turn);
- this.movesCount++;
this.updateVariables(move);
+ // Is it a sentry push? (useful for undo)
+ move.sentryPush = (this.subTurn == 2);
+ if (this.subTurn == 1) this.movesCount++;
+ if (move.appear.length == 0 && move.vanish.length == 1) this.subTurn = 2;
+ else {
+ // Turn changes only if not a sentry "pre-push"
+ this.turn = V.GetOppCol(this.turn);
+ this.subTurn = 1;
+ }
}
undo(move) {
this.epSquares.pop();
this.disaggregateFlags(JSON.parse(move.flags));
V.UndoOnBoard(this.board, move);
- // TODO: here too, take care of turn. If undoing when subTurn == 2,
- // do not change turn (this shouldn't happen anyway).
- // ==> normal undo() should be ok.
- //this.turn = V.GetOppCol(this.turn);
- this.movesCount--;
+ const L = this.sentryPush.length;
+ // Decrement movesCount except if the move is a sentry push
+ if (!move.sentryPush) this.movesCount--;
+ // Turn changes only if not undoing second part of a sentry push
+ if (!move.sentryPush || this.subTurn == 1)
+ this.turn = V.GetOppCol(this.turn);
this.unupdateVariables(move);
}
+ isAttacked(sq, colors) {
+ return (
+ super.isAttacked(sq, colors) ||
+ this.isAttackedByLancer(sq, colors) ||
+ this.isAttackedBySentry(sq, colors)
+ );
+ }
+
+ isAttackedByLancer([x, y], colors) {
+ for (let step of V.steps[V.ROOK].concat(V.steps[V.BISHOP])) {
+ // If in this direction there are only enemy pieces and empty squares,
+ // and we meet a lancer: can he reach us?
+ // NOTE: do not stop at first lancer, there might be several!
+ let coord = { x: x + step[0], y: y + step[1] };
+ let lancerPos = [];
+ while (
+ V.OnBoard(coord.x, coord.y) &&
+ (
+ this.board[coord.x][coord.y] == V.EMPTY ||
+ colors.includes(this.getColor(coord.x, coord.y))
+ )
+ ) {
+ lancerPos.push(coord);
+ }
+ for (let xy of lancerPos) {
+ const dir = V.LANCER_DIRS[this.board[xy.x][xy.y].charAt(1)];
+ if (dir[0] == -step[0] && dir[1] == -step[1]) return true;
+ }
+ }
+ return false;
+ }
+
+ // Helper to check sentries attacks:
+ selfAttack([x1, y1], [x2, y2]) {
+ const color = this.getColor(x1, y1);
+ const sliderAttack = (allowedSteps, lancer) => {
+ const deltaX = x2 - x1;
+ const deltaY = y2 - y1;
+ const step = [ deltaX / Math.abs(deltaX), deltaY / Math.abs(deltaY) ];
+ if (allowedStep.every(st => st[0] != step[0] || st[1] != step[1]))
+ return false;
+ let sq = [ x1 = step[0], y1 + step[1] ];
+ while (sq[0] != x2 && sq[1] != y2) {
+ if (
+ (!lancer && this.board[sq[0]][sq[1]] != V.EMPTY) ||
+ (!!lancer && this.getColor(sq[0], sq[1]) != color)
+ ) {
+ return false;
+ }
+ }
+ return true;
+ };
+ switch (this.getPiece(x1, y1)) {
+ case V.PAWN: {
+ // Pushed pawns move as enemy pawns
+ const shift = (color == 'w' ? 1 : -1);
+ return (x1 + shift == x2 && Math.abs(y1 - y2) == 1);
+ }
+ case V.KNIGHT: {
+ const deltaX = Math.abs(x1 - x2);
+ const deltaY = Math.abs(y1 - y2);
+ return (
+ deltaX + deltaY == 3 &&
+ [1, 2].includes(deltaX) &&
+ [1, 2].includes(deltaY)
+ );
+ }
+ case V.ROOK:
+ return sliderAttack(V.steps[V.ROOK]);
+ case V.BISHOP:
+ return sliderAttack(V.steps[V.BISHOP]);
+ case V.QUEEN:
+ return sliderAttack(V.steps[V.ROOK].concat(V.steps[V.BISHOP]));
+ case V.LANCER: {
+ // Special case: as long as no enemy units stands in-between, it attacks
+ // (if it points toward the king).
+ const allowedStep = V.LANCER_DIRS[this.board[x1][y1].charAt(1)];
+ return sliderAttack([allowedStep], "lancer");
+ }
+ // No sentries or jailer tests: they cannot self-capture
+ }
+ return false;
+ }
+
+ isAttackedBySentry([x, y], colors) {
+ // Attacked by sentry means it can self-take our king.
+ // Just check diagonals of enemy sentry(ies), and if it reaches
+ // one of our pieces: can I self-take?
+ const color = V.GetOppCol(colors[0]);
+ let candidates = [];
+ for (let i=0; i<V.size.x; i++) {
+ for (let j=0; j<V.size.y; j++) {
+ if (
+ this.getPiece(i,j) == V.SENTRY &&
+ colors.includes(this.getColor(i,j))
+ ) {
+ for (let step of V.steps[V.BISHOP]) {
+ let sq = [ i + step[0], j + step[1] ];
+ while (
+ V.OnBoard(sq[0], sq[1]) &&
+ this.board[sq[0]][sq[1]] == V.EMPTY
+ ) {
+ sq[0] += step[0];
+ sq[1] += step[1];
+ }
+ if (
+ V.OnBoard(sq[0], sq[1]) &&
+ this.getColor(sq[0], sq[1]) == color
+ ) {
+ candidates.push(sq);
+ }
+ }
+ }
+ }
+ }
+ for (let c of candidates)
+ if (this.selfAttack(c, [x, y])) return true;
+ return false;
+ }
+
+ // Jailer doesn't capture or give check
+
static get VALUES() {
return Object.assign(
{ l: 4.8, s: 2.8, j: 3.8 }, //Jeff K. estimations
);
}
+ getComputerMove() {
+ const maxeval = V.INFINITY;
+ const color = this.turn;
+ let moves1 = this.getAllValidMoves();
+
+ if (moves1.length == 0)
+ // TODO: this situation should not happen
+ return null;
+
+ const setEval = (move) => {
+ const score = this.getCurrentScore();
+ if (score != "*") {
+ move.eval =
+ score == "1/2"
+ ? 0
+ : (score == "1-0" ? 1 : -1) * maxeval;
+ } else move[i].eval = this.evalPosition();
+ };
+
+ // Just search_depth == 1 (because of sentries. TODO: can do better...)
+ moves1.forEach(m1 => {
+ this.play(m1);
+ if (this.subTurn == 1) setEval(m1);
+ else {
+ // Need to play every pushes and count:
+ const moves2 = this.getAllValidMoves();
+ moves2.forEach(m2 => {
+ this.play(m2);
+ setEval(m1);
+ this.undo(m2);
+ });
+ }
+ this.undo(m1);
+ });
+
+ moves1.sort((a, b) => {
+ return (color == "w" ? 1 : -1) * (b.eval - a.eval);
+ });
+ let candidates = [0];
+ for (let j = 1; j < moves1.length && moves1[j].eval == moves1[0].eval; j++)
+ candidates.push(j);
+ return moves1[candidates[randInt(candidates.length)]];
+ }
+
getNotation(move) {
// Special case "king takes jailer" is a pass move
if (move.appear.length == 0 && move.vanish.length == 0) return "pass";
projects / vchess.git / blobdiff