if (fenParsed.enpassant != "-")
{
const ep = V.SquareToCoords(fenParsed.enpassant);
- if (ep.y < 0 || ep.y > V.size.y || isNaN(ep.x) || ep.x < 0 || ep.x > V.size.x)
+ if (isNaN(ep.x) || !V.OnBoard(ep))
return false;
}
}
return !!flags.match(/^[01]{4,4}$/);
}
- // 3 --> d (column letter from number)
- static GetColumn(colnum)
+ // 3 --> d (column number to letter)
+ static CoordToColumn(colnum)
+ {
+ return String.fromCharCode(97 + colnum);
+ }
+
+ // d --> 3 (column letter to number)
+ static ColumnToCoord(colnum)
{
return String.fromCharCode(97 + colnum);
}
static SquareToCoords(sq)
{
return {
+ // NOTE: column is always one char => max 26 columns
+ // row is counted from black side => subtraction
x: V.size.x - parseInt(sq.substr(1)),
y: sq[0].charCodeAt() - 97
};
// {x:0,y:4} --> e8
static CoordsToSquare(coords)
{
- return V.GetColumn(coords.y) + (V.size.x - coords.x);
+ return V.CoordToColumn(coords.y) + (V.size.x - coords.x);
}
// Aggregates flags into one object
// Get random squares for bishops
let randIndex = 2 * _.random(3);
- let bishop1Pos = positions[randIndex];
+ const 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];
+ const 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];
+ const knight1Pos = positions[randIndex];
positions.splice(randIndex, 1);
randIndex = _.random(4);
- let knight2Pos = positions[randIndex];
+ const knight2Pos = positions[randIndex];
positions.splice(randIndex, 1);
// Get random square for queen
randIndex = _.random(3);
- let queenPos = positions[randIndex];
+ const queenPos = positions[randIndex];
positions.splice(randIndex, 1);
- // Rooks and king positions are now fixed, because of the ordering rook-king-rook
- let rook1Pos = positions[0];
- let kingPos = positions[1];
- let rook2Pos = positions[2];
+ // Rooks and king positions are now fixed,
+ // because of the ordering rook-king-rook
+ const rook1Pos = positions[0];
+ const kingPos = positions[1];
+ const rook2Pos = positions[2];
// Finally put the shuffled pieces in the board array
pieces[c][rook1Pos] = 'r';
}
}
- // Build a regular move from its initial and destination squares; tr: transformation
+ // Build a regular move from its initial and destination squares.
+ // tr: transformation
getBasicMove([sx,sy], [ex,ey], tr)
{
let mv = new Move({
return mv;
}
- // Generic method to find possible moves of non-pawn pieces ("sliding or jumping")
+ // Generic method to find possible moves of non-pawn pieces:
+ // "sliding or jumping"
getSlideNJumpMoves([x,y], steps, oneStep)
{
const color = this.getColor(x,y);
// What are the queen moves from square x,y ?
getPotentialQueenMoves(sq)
{
- return this.getSlideNJumpMoves(sq, V.steps[V.ROOK].concat(V.steps[V.BISHOP]));
+ return this.getSlideNJumpMoves(sq,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP]));
}
// What are the king moves from square x,y ?
continue;
// If this code is reached, rooks and king are on initial position
- // Nothing on the path of the king (and no checks; OK also if y==finalSquare)?
+ // Nothing on the path of the king ?
+ // (And no checks; OK also if y==finalSquare)
let step = finalSquares[castleSide][0] < y ? -1 : 1;
for (i=y; i!=finalSquares[castleSide][0]; i+=step)
{
if (this.isAttacked([x,i], [oppCol]) || (this.board[x][i] != V.EMPTY &&
// NOTE: next check is enough, because of chessboard constraints
- (this.getColor(x,i) != c || ![V.KING,V.ROOK].includes(this.getPiece(x,i)))))
+ (this.getColor(x,i) != c
+ || ![V.KING,V.ROOK].includes(this.getPiece(x,i)))))
{
continue castlingCheck;
}
});
}
- // Search for all valid moves considering current turn (for engine and game end)
+ // Search for all valid moves considering current turn
+ // (for engine and game end)
getAllValidMoves()
{
const color = this.turn;
{
for (let j=0; j<V.size.y; j++)
{
- // Next condition "!= oppCol" = harmless hack to work with checkered variant
+ // Next condition "!= oppCol" to work with checkered variant
if (this.board[i][j] != V.EMPTY && this.getColor(i,j) != oppCol)
- Array.prototype.push.apply(potentialMoves, this.getPotentialMovesFrom([i,j]));
+ {
+ Array.prototype.push.apply(potentialMoves,
+ this.getPotentialMovesFrom([i,j]));
+ }
}
}
- // NOTE: prefer lazy undercheck tests, letting the king being taken?
- // No: if happen on last 1/2 move, could lead to forbidden moves, wrong evals
return this.filterValid(potentialMoves);
}
return false;
}
- // Check if pieces of color in array 'colors' are attacking (king) on square x,y
+ // Check if pieces of color in 'colors' are attacking (king) on square x,y
isAttacked(sq, colors)
{
return (this.isAttackedByPawn(sq, colors)
play(move, ingame)
{
// DEBUG:
-// console.log("DO");
// if (!this.states) this.states = [];
// if (!ingame) this.states.push(this.getFen());
this.unupdateVariables(move);
// DEBUG:
-// console.log("UNDO "+this.getNotation(move));
// if (this.getFen() != this.states[this.states.length-1])
// debugger;
// this.states.pop();
// Rank moves using a min-max at depth 2
for (let i=0; i<moves1.length; i++)
{
- moves1[i].eval = (color=="w" ? -1 : 1) * maxeval; //very low, I'm checkmated
+ // Initial self evaluation is very low: "I'm checkmated"
+ moves1[i].eval = (color=="w" ? -1 : 1) * maxeval;
this.play(moves1[i]);
let eval2 = undefined;
if (this.atLeastOneMove())
{
- eval2 = (color=="w" ? 1 : -1) * maxeval; //initialized with checkmate value
+ // Initial enemy evaluation is very low too, for him
+ eval2 = (color=="w" ? 1 : -1) * maxeval;
// Second half-move:
let moves2 = this.getAllValidMoves("computer");
for (let j=0; j<moves2.length; j++)
const score = this.checkGameEnd();
evalPos = (score=="1/2" ? 0 : (score=="1-0" ? 1 : -1) * maxeval);
}
- if ((color == "w" && evalPos < eval2) || (color=="b" && evalPos > eval2))
+ if ((color == "w" && evalPos < eval2)
+ || (color=="b" && evalPos > eval2))
+ {
eval2 = evalPos;
+ }
this.undo(moves2[j]);
}
}
this.alphabeta(V.SEARCH_DEPTH-1, -maxeval, maxeval);
this.undo(moves1[i]);
}
- moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); });
+ moves1.sort( (a,b) => {
+ return (color=="w" ? 1 : -1) * (b.eval - a.eval); });
}
else
return currentBest;
if (move.vanish.length > move.appear.length)
{
// Capture
- const startColumn = String.fromCharCode(97 + move.start.y);
+ const startColumn = V.CoordToColumn(move.start.y);
notation = startColumn + "x" + finalSquare;
}
else //no capture
notation = finalSquare;
- if (move.appear.length > 0 && piece != move.appear[0].p) //promotion
+ if (move.appear.length > 0 && move.appear[0].p != V.PAWN) //promotion
notation += "=" + move.appear[0].p.toUpperCase();
return notation;
}
projects / vchess.git / blobdiff