import { ChessRules } from "@/base_rules";
-import { randInt } from "@/utils/alea";
export class Doublemove1Rules extends ChessRules {
+
static IsGoodEnpassant(enpassant) {
const squares = enpassant.split(",");
if (squares.length > 2) return false;
return moves;
}
+ atLeastOneMove() {
+ const color = this.turn;
+ for (let i = 0; i < V.size.x; i++) {
+ for (let j = 0; j < V.size.y; j++) {
+ if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == color) {
+ const moves = this.getPotentialMovesFrom([i, j]);
+ if (moves.length > 0) {
+ for (let k = 0; k < moves.length; k++) {
+ const m = moves[k];
+ // NOTE: not using play() here (=> infinite loop)
+ V.PlayOnBoard(this.board, m);
+ if (m.vanish[0].p == V.KING)
+ this.kingPos[color] = [m.appear[0].x, m.appear[0].y];
+ const res = !this.underCheck(color);
+ V.UndoOnBoard(this.board, m);
+ if (m.vanish[0].p == V.KING)
+ this.kingPos[color] = [m.start.x, m.start.y];
+ if (res) return true;
+ }
+ }
+ }
+ }
+ }
+ return false;
+ }
+
play(move) {
move.flags = JSON.stringify(this.aggregateFlags());
move.turn = [this.turn, this.subTurn];
V.PlayOnBoard(this.board, move);
const epSq = this.getEpSquare(move);
+ const oppCol = V.GetOppCol(this.turn);
if (this.movesCount == 0) {
// First move in game
this.turn = "b";
this.epSquares.push([epSq]);
this.movesCount = 1;
}
- // Does this move give check on subturn 1? If yes, skip subturn 2
- else if (this.subTurn == 1 && this.underCheck(V.GetOppCol(this.turn))) {
- this.turn = V.GetOppCol(this.turn);
+ // Does this move give check on subturn 1 or reach stalemate?
+ // If yes, skip subturn 2
+ else if (
+ this.subTurn == 1 &&
+ (
+ this.underCheck(V.GetOppCol(this.turn)) ||
+ !this.atLeastOneMove()
+ )
+ ) {
+ this.turn = oppCol;
this.epSquares.push([epSq]);
move.checkOnSubturn1 = true;
this.movesCount++;
}
else {
if (this.subTurn == 2) {
- this.turn = V.GetOppCol(this.turn);
+ this.turn = oppCol;
let lastEpsq = this.epSquares[this.epSquares.length - 1];
lastEpsq.push(epSq);
}
const piece = move.vanish[0].p;
const firstRank = c == "w" ? V.size.x - 1 : 0;
- if (piece == V.KING && move.appear.length > 0) {
- this.kingPos[c][0] = move.appear[0].x;
- this.kingPos[c][1] = move.appear[0].y;
+ if (piece == V.KING) {
+ this.kingPos[c] = [move.appear[0].x, move.appear[0].y];
this.castleFlags[c] = [V.size.y, V.size.y];
return;
}
const flagIdx = (move.start.y == this.castleFlags[c][0] ? 0 : 1);
this.castleFlags[c][flagIdx] = V.size.y;
}
- else if (
+ if (
move.end.x == oppFirstRank && //we took opponent rook?
this.castleFlags[oppCol].includes(move.end.y)
) {
};
const moves11 = this.getAllValidMoves();
- let doubleMoves = [];
+ let doubleMove = null;
+ let bestEval = Number.POSITIVE_INFINITY * (color == 'w' ? -1 : 1);
// Rank moves using a min-max at depth 2
for (let i = 0; i < moves11.length; i++) {
this.play(moves11[i]);
if (this.turn != color) {
// We gave check with last move: search the best opponent move
- doubleMoves.push({ moves: [moves11[i]], eval: getBestMoveEval() });
+ const evalM = getBestMoveEval() + 0.05 - Math.random() / 10;
+ if (
+ (color == 'w' && evalM > bestEval) ||
+ (color == 'b' && evalM < bestEval)
+ ) {
+ doubleMove = moves11[i];
+ bestEval = evalM;
+ }
}
else {
let moves12 = this.getAllValidMoves();
for (let j = 0; j < moves12.length; j++) {
this.play(moves12[j]);
- doubleMoves.push({
- moves: [moves11[i], moves12[j]],
- eval: getBestMoveEval() + 0.05 - Math.random() / 10
- });
+ const evalM = getBestMoveEval() + 0.05 - Math.random() / 10
+ if (
+ (color == 'w' && evalM > bestEval) ||
+ (color == 'b' && evalM < bestEval)
+ ) {
+ doubleMove = [moves11[i], moves12[j]];
+ bestEval = evalM;
+ }
this.undo(moves12[j]);
}
}
this.undo(moves11[i]);
}
-
- // TODO: array + sort + candidates logic not required when adding small
- // fluctuations to the eval function (could also be generalized).
- doubleMoves.sort((a, b) => {
- return (color == "w" ? 1 : -1) * (b.eval - a.eval);
- });
- let candidates = [0]; //indices of candidates moves
- for (
- let i = 1;
- i < doubleMoves.length && doubleMoves[i].eval == doubleMoves[0].eval;
- i++
- ) {
- candidates.push(i);
- }
- const selected = doubleMoves[randInt(candidates.length)].moves;
- if (selected.length == 1) return selected[0];
- return selected;
+ return doubleMove;
}
+
};