static GetBoard(fen)
{
let rows = fen.split(" ")[0].split("/");
- let [sizeX,sizeY] = VariantRules.size;
+ const [sizeX,sizeY] = VariantRules.size;
let board = doubleArray(sizeX, sizeY, "");
for (let i=0; i<rows.length; i++)
{
return undefined; //default
}
- // can color1 take color2?
- canTake(color1, color2)
+ // can thing on square1 take thing on square2
+ canTake([x1,y1], [x2,y2])
{
- return color1 != color2;
+ return this.getColor(x1,y1) != this.getColor(x2,y2);
}
///////////////////
// All possible moves from selected square (assumption: color is OK)
getPotentialMovesFrom([x,y])
{
- let c = this.getColor(x,y);
- // Fill possible moves according to piece type
switch (this.getPiece(x,y))
{
case VariantRules.PAWN:
- return this.getPotentialPawnMoves(x,y,c);
+ return this.getPotentialPawnMoves([x,y]);
case VariantRules.ROOK:
- return this.getPotentialRookMoves(x,y,c);
+ return this.getPotentialRookMoves([x,y]);
case VariantRules.KNIGHT:
- return this.getPotentialKnightMoves(x,y,c);
+ return this.getPotentialKnightMoves([x,y]);
case VariantRules.BISHOP:
- return this.getPotentialBishopMoves(x,y,c);
+ return this.getPotentialBishopMoves([x,y]);
case VariantRules.QUEEN:
- return this.getPotentialQueenMoves(x,y,c);
+ return this.getPotentialQueenMoves([x,y]);
case VariantRules.KING:
- return this.getPotentialKingMoves(x,y,c);
+ return this.getPotentialKingMoves([x,y]);
}
}
// Build a regular move from its initial and destination squares; tr: transformation
- getBasicMove(sx, sy, ex, ey, tr)
+ getBasicMove([sx,sy], [ex,ey], tr)
{
var mv = new Move({
appear: [
new PiPo({
x: ex,
y: ey,
- c: this.getColor(sx,sy),
- p: !!tr ? tr : this.getPiece(sx,sy)
+ c: !!tr ? tr.c : this.getColor(sx,sy),
+ p: !!tr ? tr.p : this.getPiece(sx,sy)
})
],
vanish: [
}
// Generic method to find possible moves of non-pawn pieces ("sliding or jumping")
- getSlideNJumpMoves(x, y, color, steps, oneStep)
+ getSlideNJumpMoves([x,y], steps, oneStep)
{
+ const color = this.getColor(x,y);
var moves = [];
- let [sizeX,sizeY] = VariantRules.size;
+ const [sizeX,sizeY] = VariantRules.size;
outerLoop:
for (let step of steps)
{
- var i = x + step[0];
- var j = y + step[1];
+ let i = x + step[0];
+ let j = y + step[1];
while (i>=0 && i<sizeX && j>=0 && j<sizeY && this.board[i][j] == VariantRules.EMPTY)
{
- moves.push(this.getBasicMove(x, y, i, j));
+ moves.push(this.getBasicMove([x,y], [i,j]));
if (oneStep !== undefined)
continue outerLoop;
i += step[0];
j += step[1];
}
- if (i>=0 && i<8 && j>=0 && j<8 && this.canTake(color, this.getColor(i,j)))
- moves.push(this.getBasicMove(x, y, i, j));
+ if (i>=0 && i<8 && j>=0 && j<8 && this.canTake([x,y], [i,j]))
+ moves.push(this.getBasicMove([x,y], [i,j]));
}
return moves;
}
// What are the pawn moves from square x,y considering color "color" ?
- getPotentialPawnMoves(x, y, color)
+ getPotentialPawnMoves([x,y])
{
+ const color = this.getColor(x,y);
var moves = [];
var V = VariantRules;
- let [sizeX,sizeY] = VariantRules.size;
+ const [sizeX,sizeY] = VariantRules.size;
let shift = (color == "w" ? -1 : 1);
let startRank = (color == "w" ? sizeY-2 : 1);
let lastRank = (color == "w" ? 0 : sizeY-1);
// Normal moves
if (this.board[x+shift][y] == V.EMPTY)
{
- moves.push(this.getBasicMove(x, y, x+shift, y));
+ moves.push(this.getBasicMove([x,y], [x+shift,y]));
if (x==startRank && this.board[x+2*shift][y] == V.EMPTY)
{
// Two squares jump
- moves.push(this.getBasicMove(x, y, x+2*shift, y));
+ moves.push(this.getBasicMove([x,y], [x+2*shift,y]));
}
}
// Captures
- if (y>0 && this.canTake(this.getColor(x,y), this.getColor(x+shift,y-1))
- && this.board[x+shift][y-1] != V.EMPTY)
- {
- moves.push(this.getBasicMove(x, y, x+shift, y-1));
- }
- if (y<sizeY-1 && this.canTake(this.getColor(x,y), this.getColor(x+shift,y+1))
- && this.board[x+shift][y+1] != V.EMPTY)
- {
- moves.push(this.getBasicMove(x, y, x+shift, y+1));
- }
+ 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]));
+ if (y<sizeY-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]));
}
if (x+shift == lastRank)
promotionPieces.forEach(p => {
// Normal move
if (this.board[x+shift][y] == V.EMPTY)
- moves.push(this.getBasicMove(x, y, x+shift, y, p));
+ moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:p}));
// Captures
- if (y>0 && this.canTake(this.getColor(x,y), this.getColor(x+shift,y-1))
- && this.board[x+shift][y-1] != V.EMPTY)
- {
- moves.push(this.getBasicMove(x, y, x+shift, y-1, p));
- }
- if (y<sizeY-1 && this.canTake(this.getColor(x,y), this.getColor(x+shift,y+1))
- && this.board[x+shift][y+1] != V.EMPTY)
- {
- moves.push(this.getBasicMove(x, y, x+shift, y+1, p));
- }
+ 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:p}));
+ if (y<sizeY-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:p}));
});
}
if (!!epSquare && epSquare.x == x+shift && Math.abs(epSquare.y - y) == 1)
{
let epStep = epSquare.y - y;
- var enpassantMove = this.getBasicMove(x, y, x+shift, y+epStep);
+ var enpassantMove = this.getBasicMove([x,y], [x+shift,y+epStep]);
enpassantMove.vanish.push({
x: x,
y: y+epStep,
}
// What are the rook moves from square x,y ?
- getPotentialRookMoves(x, y, color)
+ getPotentialRookMoves(sq)
{
- return this.getSlideNJumpMoves(
- x, y, color, VariantRules.steps[VariantRules.ROOK]);
+ return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.ROOK]);
}
// What are the knight moves from square x,y ?
- getPotentialKnightMoves(x, y, color)
+ getPotentialKnightMoves(sq)
{
- return this.getSlideNJumpMoves(
- x, y, color, VariantRules.steps[VariantRules.KNIGHT], "oneStep");
+ return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.KNIGHT], "oneStep");
}
// What are the bishop moves from square x,y ?
- getPotentialBishopMoves(x, y, color)
+ getPotentialBishopMoves(sq)
{
- return this.getSlideNJumpMoves(
- x, y, color, VariantRules.steps[VariantRules.BISHOP]);
+ return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.BISHOP]);
}
// What are the queen moves from square x,y ?
- getPotentialQueenMoves(x, y, color)
+ getPotentialQueenMoves(sq)
{
- return this.getSlideNJumpMoves(
- x, y, color, VariantRules.steps[VariantRules.QUEEN]);
+ return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.QUEEN]);
}
// What are the king moves from square x,y ?
- getPotentialKingMoves(x, y, c)
+ getPotentialKingMoves(sq)
{
// Initialize with normal moves
- var moves = this.getSlideNJumpMoves(x, y, c,
- VariantRules.steps[VariantRules.QUEEN], "oneStep");
-
- return moves.concat(this.getCastleMoves(x,y,c));
+ let moves = this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.QUEEN], "oneStep");
+ return moves.concat(this.getCastleMoves(sq));
}
- getCastleMoves(x,y,c)
+ getCastleMoves([x,y])
{
+ const c = this.getColor(x,y);
if (x != (c=="w" ? 7 : 0) || y != this.INIT_COL_KING[c])
return []; //x isn't first rank, or king has moved (shortcut)
///////////////////
// MOVES VALIDATION
- canIplay(color, sq)
+ canIplay(side, [x,y])
{
- return ((color=='w' && this.moves.length%2==0)
- || (color=='b' && this.moves.length%2==1))
- && this.getColor(sq[0], sq[1]) == color;
+ return ((side=='w' && this.moves.length%2==0) || (side=='b' && this.moves.length%2==1))
+ && this.getColor(x,y) == side;
}
getPossibleMovesFrom(sq)
{
if (moves.length == 0)
return [];
- let color = this.getColor( moves[0].start.x, moves[0].start.y );
- return moves.filter(m => {
- return !this.underCheck(m, color);
- });
+ let color = this.turn;
+ return moves.filter(m => { return !this.underCheck(m, color); });
}
// Search for all valid moves considering current turn (for engine and game end)
- getAllValidMoves(color)
+ getAllValidMoves()
{
+ const color = this.turn;
const oppCol = this.getOppCol(color);
var potentialMoves = [];
let [sizeX,sizeY] = VariantRules.size;
}
// Stop at the first move found
- atLeastOneMove(color)
+ atLeastOneMove()
{
+ const color = this.turn;
const oppCol = this.getOppCol(color);
let [sizeX,sizeY] = VariantRules.size;
for (var i=0; i<sizeX; i++)
return false;
}
- // Check if pieces of color 'color' are attacking square x,y
- isAttacked(sq, color)
+ // Check if pieces of color 'colors' are attacking square x,y
+ isAttacked(sq, colors)
{
- return (this.isAttackedByPawn(sq, color)
- || this.isAttackedByRook(sq, color)
- || this.isAttackedByKnight(sq, color)
- || this.isAttackedByBishop(sq, color)
- || this.isAttackedByQueen(sq, color)
- || this.isAttackedByKing(sq, color));
+ return (this.isAttackedByPawn(sq, colors)
+ || this.isAttackedByRook(sq, colors)
+ || this.isAttackedByKnight(sq, colors)
+ || this.isAttackedByBishop(sq, colors)
+ || this.isAttackedByQueen(sq, colors)
+ || this.isAttackedByKing(sq, colors));
}
// Is square x,y attacked by pawns of color c ?
- isAttackedByPawn([x,y], c)
+ isAttackedByPawn([x,y], colors)
{
- let pawnShift = (c=="w" ? 1 : -1);
- if (x+pawnShift>=0 && x+pawnShift<8)
+ for (let c of colors)
{
- for (let i of [-1,1])
+ let pawnShift = (c=="w" ? 1 : -1);
+ if (x+pawnShift>=0 && x+pawnShift<8)
{
- if (y+i>=0 && y+i<8 && this.getPiece(x+pawnShift,y+i)==VariantRules.PAWN
- && this.getColor(x+pawnShift,y+i)==c)
+ for (let i of [-1,1])
{
- return true;
+ if (y+i>=0 && y+i<8 && this.getPiece(x+pawnShift,y+i)==VariantRules.PAWN
+ && this.getColor(x+pawnShift,y+i)==c)
+ {
+ return true;
+ }
}
}
}
}
// Is square x,y attacked by rooks of color c ?
- isAttackedByRook(sq, color)
+ isAttackedByRook(sq, colors)
{
- return this.isAttackedBySlideNJump(sq, color,
+ return this.isAttackedBySlideNJump(sq, colors,
VariantRules.ROOK, VariantRules.steps[VariantRules.ROOK]);
}
// Is square x,y attacked by knights of color c ?
- isAttackedByKnight(sq, color)
+ isAttackedByKnight(sq, colors)
{
- return this.isAttackedBySlideNJump(sq, color,
+ return this.isAttackedBySlideNJump(sq, colors,
VariantRules.KNIGHT, VariantRules.steps[VariantRules.KNIGHT], "oneStep");
}
// Is square x,y attacked by bishops of color c ?
- isAttackedByBishop(sq, color)
+ isAttackedByBishop(sq, colors)
{
- return this.isAttackedBySlideNJump(sq, color,
+ return this.isAttackedBySlideNJump(sq, colors,
VariantRules.BISHOP, VariantRules.steps[VariantRules.BISHOP]);
}
// Is square x,y attacked by queens of color c ?
- isAttackedByQueen(sq, color)
+ isAttackedByQueen(sq, colors)
{
- return this.isAttackedBySlideNJump(sq, color,
+ return this.isAttackedBySlideNJump(sq, colors,
VariantRules.QUEEN, VariantRules.steps[VariantRules.QUEEN]);
}
// Is square x,y attacked by king of color c ?
- isAttackedByKing(sq, color)
+ isAttackedByKing(sq, colors)
{
- return this.isAttackedBySlideNJump(sq, color,
+ return this.isAttackedBySlideNJump(sq, colors,
VariantRules.KING, VariantRules.steps[VariantRules.QUEEN], "oneStep");
}
// Generic method for non-pawn pieces ("sliding or jumping"): is x,y attacked by piece != color ?
- isAttackedBySlideNJump([x,y], c,piece,steps,oneStep)
+ isAttackedBySlideNJump([x,y], colors, piece, steps, oneStep)
{
for (let step of steps)
{
ry += step[1];
}
if (rx>=0 && rx<8 && ry>=0 && ry<8 && this.board[rx][ry] != VariantRules.EMPTY
- && this.getPiece(rx,ry) == piece && this.getColor(rx,ry) == c)
+ && this.getPiece(rx,ry) == piece && colors.includes(this.getColor(rx,ry)))
{
return true;
}
}
// Is color c under check after move ?
- underCheck(move, c)
+ underCheck(move)
{
+ const color = this.turn;
this.play(move);
- let res = this.isAttacked(this.kingPos[c], this.getOppCol(c));
+ let res = this.isAttacked(this.kingPos[color], this.getOppCol(color));
this.undo(move);
return res;
}
// On which squares is color c under check (after move) ?
- getCheckSquares(move, c)
+ getCheckSquares(move)
{
this.play(move);
- let res = this.isAttacked(this.kingPos[c], this.getOppCol(c))
- ? [ JSON.parse(JSON.stringify(this.kingPos[c])) ] //need to duplicate!
+ const color = this.turn;
+ let res = this.isAttacked(this.kingPos[color], this.getOppCol(color))
+ ? [ JSON.parse(JSON.stringify(this.kingPos[color])) ] //need to duplicate!
: [ ];
this.undo(move);
return res;
//////////////
// END OF GAME
- checkGameOver(color)
+ checkGameOver()
{
// Check for 3 repetitions
if (this.moves.length >= 8)
}
}
- if (this.atLeastOneMove(color))
+ if (this.atLeastOneMove())
{
// game not over
return "*";
}
// Game over
- return this.checkGameEnd(color);
+ return this.checkGameEnd();
}
- // Useful stand-alone for engine
- checkGameEnd(color)
+ // No moves are possible: compute score
+ checkGameEnd()
{
+ const color = this.turn;
// No valid move: stalemate or checkmate?
if (!this.isAttacked(this.kingPos[color], this.getOppCol(color)))
return "1/2";
}
// Assumption: at least one legal move
- getComputerMove(color)
+ getComputerMove()
{
- const oppCol = this.getOppCol(color);
+ const color = this.turn;
// Rank moves using a min-max at depth 2
- let moves1 = this.getAllValidMoves(color);
+ let moves1 = this.getAllValidMoves();
for (let i=0; i<moves1.length; i++)
{
let eval2 = (color=="w" ? 1 : -1) * 1000; //initialized with very high (checkmate) value
this.play(moves1[i]);
// Second half-move:
- let moves2 = this.getAllValidMoves(oppCol);
+ let moves2 = this.getAllValidMoves();
// If no possible moves AND underCheck, eval2 is correct.
// If !underCheck, eval2 is 0 (stalemate).
- if (moves2.length == 0 && this.checkGameEnd(oppCol) == "1/2")
+ if (moves2.length == 0 && this.checkGameEnd() == "1/2")
eval2 = 0;
for (let j=0; j<moves2.length; j++)
{
{
this.play(moves1[i]);
// 0.1 * oldEval : heuristic to avoid some bad moves (not all...)
- moves1[i].eval = 0.1*moves1[i].eval + this.alphabeta(oppCol, color, 2, -1000, 1000);
+ moves1[i].eval = 0.1*moves1[i].eval + this.alphabeta(2, -1000, 1000);
this.undo(moves1[i]);
}
moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); });
return moves1[_.sample(candidates, 1)];
}
- alphabeta(color, oppCol, depth, alpha, beta)
+ alphabeta(depth, alpha, beta)
{
- if (!this.atLeastOneMove(color))
+ const color = this.turn;
+ if (!this.atLeastOneMove())
{
- switch (this.checkGameEnd(color))
+ switch (this.checkGameEnd())
{
case "1/2": return 0;
default: return color=="w" ? -1000 : 1000;
}
if (depth == 0)
return this.evalPosition();
- const moves = this.getAllValidMoves(color);
+ const moves = this.getAllValidMoves();
let v = color=="w" ? -1000 : 1000;
if (color == "w")
{
for (let i=0; i<moves.length; i++)
{
this.play(moves[i]);
- v = Math.max(v, this.alphabeta(oppCol, color, depth-1, alpha, beta));
+ v = Math.max(v, this.alphabeta(depth-1, alpha, beta));
this.undo(moves[i]);
alpha = Math.max(alpha, v);
if (alpha >= beta)
for (let i=0; i<moves.length; i++)
{
this.play(moves[i]);
- v = Math.min(v, this.alphabeta(oppCol, color, depth-1, alpha, beta));
+ v = Math.min(v, this.alphabeta(depth-1, alpha, beta));
this.undo(moves[i]);
beta = Math.min(beta, v);
if (alpha >= beta)
projects / vchess.git / blobdiff