--- /dev/null
+class LosersRules extends ChessRules
+{
+ static get HasFlags() { return false; }
+
+ 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");
+ }
+
+ // Stop at the first capture found (if any)
+ 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;
+ }
+ }
+ }
+ }
+ }
+ 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);
+ return moves;
+ }
+
+ getAllValidMoves()
+ {
+ let moves = super.getAllValidMoves();
+ if (moves.some(m => { return m.vanish.length == 2; }))
+ moves = 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) { }
+
+ checkGameEnd()
+ {
+ // No valid move: you win!
+ 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
+ };
+ }
+
+ static get SEARCH_DEPTH() { return 4; }
+
+ evalPosition()
+ {
+ return - super.evalPosition(); //better with less material
+ }
+
+ 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 = _.range(8);
+
+ // Get random squares for bishops
+ let randIndex = 2 * _.random(3);
+ let bishop1Pos = positions[randIndex];
+ // The second bishop must be on a square of different color
+ let randIndex_tmp = 2 * _.random(3) + 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 = _.random(5);
+ let knight1Pos = positions[randIndex];
+ positions.splice(randIndex, 1);
+ randIndex = _.random(4);
+ let knight2Pos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ // Get random square for queen
+ randIndex = _.random(3);
+ let queenPos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ // Random square for king (no castle)
+ randIndex = _.random(2);
+ 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 -"; //no en-passant
+ }
+}
projects / vchess.git / blobdiff