import { ArrayFun } from "@/utils/array";
import { randInt } from "@/utils/alea";
-export const VariantRules = class LosersRules extends ChessRules
-{
- static get HasFlags() { return false; }
+export class LosersRules extends ChessRules {
- getPotentialPawnMoves([x,y])
- {
- let moves = super.getPotentialPawnMoves([x,y]);
-
- // Complete with promotion(s) into king, if possible
- const color = this.turn;
- const shift = (color == "w" ? -1 : 1);
- const lastRank = (color == "w" ? 0 : V.size.x-1);
- if (x+shift == lastRank)
- {
- // Normal move
- if (this.board[x+shift][y] == V.EMPTY)
- moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:V.KING}));
- // Captures
- if (y>0 && this.canTake([x,y], [x+shift,y-1])
- && this.board[x+shift][y-1] != V.EMPTY)
- {
- moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:color,p:V.KING}));
- }
- if (y<V.size.y-1 && this.canTake([x,y], [x+shift,y+1])
- && this.board[x+shift][y+1] != V.EMPTY)
- {
- moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:color,p:V.KING}));
- }
- }
-
- return moves;
- }
-
- getPotentialKingMoves(sq)
- {
- // No castle:
- return this.getSlideNJumpMoves(sq,
- V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
+ // Trim all non-capturing moves
+ static KeepCaptures(moves) {
+ return moves.filter(m => m.vanish.length == 2 && m.appear.length == 1);
}
// Stop at the first capture found (if any)
- atLeastOneCapture()
- {
+ atLeastOneCapture() {
const color = this.turn;
- const oppCol = V.GetOppCol(color);
- 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) != oppCol)
- {
- const moves = this.getPotentialMovesFrom([i,j]);
- if (moves.length > 0)
- {
- for (let k=0; k<moves.length; k++)
- {
- if (moves[k].vanish.length==2 && this.filterValid([moves[k]]).length > 0)
- return true;
- }
- }
+ 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 &&
+ this.getPotentialMovesFrom([i, j]).some(m => {
+ return (
+ // Warning: discard castle moves
+ m.vanish.length == 2 && m.appear.length == 1 &&
+ this.filterValid([m]).length == 1
+ );
+ })
+ ) {
+ return true;
}
}
}
return false;
}
- // Trim all non-capturing moves
- static KeepCaptures(moves)
- {
- return moves.filter(m => { return m.vanish.length == 2; });
- }
-
- getPossibleMovesFrom(sq)
- {
- let moves = this.filterValid( this.getPotentialMovesFrom(sq) );
- // This is called from interface: we need to know if a capture is possible
- if (this.atLeastOneCapture())
- moves = V.KeepCaptures(moves);
+ getPossibleMovesFrom(sq) {
+ let moves = this.filterValid(this.getPotentialMovesFrom(sq));
+ const captureMoves = V.KeepCaptures(moves);
+ if (captureMoves.length > 0) return captureMoves;
+ if (this.atLeastOneCapture()) return [];
return moves;
}
- getAllValidMoves()
- {
- let moves = super.getAllValidMoves();
- if (moves.some(m => { return m.vanish.length == 2; }))
- moves = V.KeepCaptures(moves);
+ getAllValidMoves() {
+ const moves = super.getAllValidMoves();
+ if (moves.some(m => m.vanish.length == 2 && m.appear.length == 1))
+ return V.KeepCaptures(moves);
return moves;
}
- underCheck(color)
- {
- return false; //No notion of check
- }
-
- getCheckSquares(move)
- {
- return [];
- }
-
- // No variables update because no royal king + no castling
- updateVariables(move) { }
- unupdateVariables(move) { }
-
- getCurrentScore()
- {
- if (this.atLeastOneMove()) // game not over
- return "*";
-
- // No valid move: the side who cannot move wins
- return (this.turn == "w" ? "1-0" : "0-1");
- }
-
- static get VALUES()
- {
- // Experimental...
- return {
- 'p': 1,
- 'r': 7,
- 'n': 3,
- 'b': 3,
- 'q': 5,
- 'k': 5
- };
+ getCurrentScore() {
+ // If only my king remains, I win
+ const color = this.turn;
+ let onlyKing = true;
+ outerLoop: 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 &&
+ this.getPiece(i,j) != V.KING
+ ) {
+ onlyKing = false;
+ break outerLoop;
+ }
+ }
+ }
+ if (onlyKing) return color == "w" ? "1-0" : "0-1";
+ if (this.atLeastOneMove()) return "*";
+ // No valid move: the side who cannot move (or is checkmated) wins
+ return this.turn == "w" ? "1-0" : "0-1";
}
- static get SEARCH_DEPTH() { return 4; }
-
- evalPosition()
- {
- return - super.evalPosition(); //better with less material
+ evalPosition() {
+ // Less material is better (more subtle in fact but...)
+ return -super.evalPosition();
}
- static GenRandInitFen()
- {
- let pieces = { "w": new Array(8), "b": new Array(8) };
- // Shuffle pieces on first and last rank
- for (let c of ["w","b"])
- {
- let positions = ArrayFun.range(8);
-
- // Get random squares for bishops
- let randIndex = 2 * randInt(4);
- let bishop1Pos = positions[randIndex];
- // The second bishop must be on a square of different color
- let randIndex_tmp = 2 * randInt(4) + 1;
- let bishop2Pos = positions[randIndex_tmp];
- // Remove chosen squares
- positions.splice(Math.max(randIndex,randIndex_tmp), 1);
- positions.splice(Math.min(randIndex,randIndex_tmp), 1);
-
- // Get random squares for knights
- randIndex = randInt(6);
- let knight1Pos = positions[randIndex];
- positions.splice(randIndex, 1);
- randIndex = randInt(5);
- let knight2Pos = positions[randIndex];
- positions.splice(randIndex, 1);
-
- // Get random square for queen
- randIndex = randInt(4);
- let queenPos = positions[randIndex];
- positions.splice(randIndex, 1);
-
- // Random square for king (no castle)
- randIndex = randInt(3);
- let kingPos = positions[randIndex];
- positions.splice(randIndex, 1);
-
- // Rooks positions are now fixed
- let rook1Pos = positions[0];
- let rook2Pos = positions[1];
-
- // Finally put the shuffled pieces in the board array
- pieces[c][rook1Pos] = 'r';
- pieces[c][knight1Pos] = 'n';
- pieces[c][bishop1Pos] = 'b';
- pieces[c][queenPos] = 'q';
- pieces[c][kingPos] = 'k';
- pieces[c][bishop2Pos] = 'b';
- pieces[c][knight2Pos] = 'n';
- pieces[c][rook2Pos] = 'r';
- }
- return pieces["b"].join("") +
- "/pppppppp/8/8/8/8/PPPPPPPP/" +
- pieces["w"].join("").toUpperCase() +
- " w 0 -"; //en-passant allowed, but no flags
- }
-}
+};
projects / vchess.git / blobdiff