+// (Orthodox) Chess rules are defined in ChessRules class.
+// Variants generally inherit from it, and modify some parts.
+
class PiPo //Piece+Position
{
// o: {piece[p], color[c], posX[x], posY[y]}
}
}
+// TODO: for animation, moves should contains "moving" and "fading" maybe...
class Move
{
// o: {appear, vanish, [start,] [end,]}
{
this.INIT_COL_KING = {'w':-1, 'b':-1};
this.INIT_COL_ROOK = {'w':[-1,-1], 'b':[-1,-1]};
- this.kingPos = {'w':[-1,-1], 'b':[-1,-1]}; //respective squares of white and black king
+ this.kingPos = {'w':[-1,-1], 'b':[-1,-1]}; //squares of white and black king
const fenParts = fen.split(" ");
const position = fenParts[0].split("/");
for (let i=0; i<position.length; i++)
return board;
}
- // Overridable: flags can change a lot
+ // Extract (relevant) flags from fen
setFlags(fen)
{
// white a-castle, h-castle, black a-castle, h-castle
///////////////////
// GETTERS, SETTERS
- // Simple useful getters
static get size() { return [8,8]; }
// Two next functions return 'undefined' if called on empty square
getColor(i,j) { return this.board[i][j].charAt(0); }
return undefined; //default
}
- // can thing on square1 take thing on square2
+ // Can thing on square1 take thing on square2
canTake([x1,y1], [x2,y2])
{
return this.getColor(x1,y1) != this.getColor(x2,y2);
return moves;
}
- // What are the pawn moves from square x,y considering color "color" ?
+ // What are the pawn moves from square x,y ?
getPotentialPawnMoves([x,y])
{
const color = this.turn;
if (x+shift == lastRank)
{
// Promotion
+ const pawnColor = this.getColor(x,y); //can be different for checkered
let promotionPieces = [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN];
promotionPieces.forEach(p => {
// Normal move
if (this.board[x+shift][y] == V.EMPTY)
- moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:p}));
+ moves.push(this.getBasicMove([x,y], [x+shift,y], {c:pawnColor,p:p}));
// 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:p}));
+ moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:pawnColor,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}));
+ moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:pawnColor,p:p}));
}
});
}
// What are the knight moves from square x,y ?
getPotentialKnightMoves(sq)
{
- return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.KNIGHT], "oneStep");
+ return this.getSlideNJumpMoves(
+ sq, VariantRules.steps[VariantRules.KNIGHT], "oneStep");
}
// What are the bishop moves from square x,y ?
canIplay(side, [x,y])
{
- return ((side=='w' && this.moves.length%2==0) || (side=='b' && this.moves.length%2==1))
+ return ((side=='w' && this.moves.length%2==0)
+ || (side=='b' && this.moves.length%2==1))
&& this.getColor(x,y) == side;
}
return this.filterValid( this.getPotentialMovesFrom(sq) );
}
- // TODO: once a promotion is filtered, the others results are same: useless computations
+ // TODO: promotions (into R,B,N,Q) should be filtered only once
filterValid(moves)
{
if (moves.length == 0)
{
for (let j=0; j<sizeY; j++)
{
- // Next condition ... != oppCol is a little HACK to work with checkered variant
+ // Next condition "!= oppCol" = harmless hack to work with checkered variant
if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) != oppCol)
Array.prototype.push.apply(potentialMoves, this.getPotentialMovesFrom([i,j]));
}
return false;
}
- // Check if pieces of color 'colors' are attacking square x,y
+ // Check if pieces of color in array 'colors' are attacking square x,y
isAttacked(sq, colors)
{
return (this.isAttackedByPawn(sq, colors)
|| this.isAttackedByKing(sq, colors));
}
- // Is square x,y attacked by pawns of color c ?
+ // Is square x,y attacked by 'colors' pawns ?
isAttackedByPawn([x,y], colors)
{
const [sizeX,sizeY] = VariantRules.size;
return false;
}
- // Is square x,y attacked by rooks of color c ?
+ // Is square x,y attacked by 'colors' rooks ?
isAttackedByRook(sq, colors)
{
return this.isAttackedBySlideNJump(sq, colors,
VariantRules.ROOK, VariantRules.steps[VariantRules.ROOK]);
}
- // Is square x,y attacked by knights of color c ?
+ // Is square x,y attacked by 'colors' knights ?
isAttackedByKnight(sq, colors)
{
return this.isAttackedBySlideNJump(sq, colors,
VariantRules.KNIGHT, VariantRules.steps[VariantRules.KNIGHT], "oneStep");
}
- // Is square x,y attacked by bishops of color c ?
+ // Is square x,y attacked by 'colors' bishops ?
isAttackedByBishop(sq, colors)
{
return this.isAttackedBySlideNJump(sq, colors,
VariantRules.BISHOP, VariantRules.steps[VariantRules.BISHOP]);
}
- // Is square x,y attacked by queens of color c ?
+ // Is square x,y attacked by 'colors' queens ?
isAttackedByQueen(sq, colors)
{
const V = VariantRules;
V.steps[V.ROOK].concat(V.steps[V.BISHOP]));
}
- // Is square x,y attacked by king of color c ?
+ // Is square x,y attacked by 'colors' king(s) ?
isAttackedByKing(sq, colors)
{
const V = VariantRules;
}
// Generic method for non-pawn pieces ("sliding or jumping"):
- // is x,y attacked by piece !of color in colors?
+ // is x,y attacked by a piece of color in array 'colors' ?
isAttackedBySlideNJump([x,y], colors, piece, steps, oneStep)
{
const [sizeX,sizeY] = VariantRules.size;
return false;
}
- // Is color c under check after move ?
+ // Is current player under check after his move ?
underCheck(move)
{
const color = this.turn;
return res;
}
- // On which squares is color c under check (after move) ?
+ // On which squares is opponent under check after our move ?
getCheckSquares(move)
{
this.play(move);
}
}
+ // After move is undo-ed, un-update variables (flags are reset)
+ // TODO: more symmetry, by storing flags increment in move...
unupdateVariables(move)
{
// (Potentially) Reset king position
play(move, ingame)
{
- // DEBUG:
-// if (!this.states) this.states = [];
-// if (!ingame) this.states.push(JSON.stringify(this.board));
-
if (!!ingame)
move.notation = [this.getNotation(move), this.getLongNotation(move)];
this.moves.pop();
this.unupdateVariables(move);
this.parseFlags(JSON.parse(move.flags));
-
- // DEBUG:
-// let state = this.states.pop();
-// if (JSON.stringify(this.board) != state)
-// debugger;
}
//////////////
// END OF GAME
+ // Basic check for 3 repetitions (in the last moves only)
checkRepetition()
{
- // Check for 3 repetitions
if (this.moves.length >= 8)
{
- // NOTE: crude detection, only moves repetition
const L = this.moves.length;
if (_.isEqual(this.moves[L-1], this.moves[L-5]) &&
_.isEqual(this.moves[L-2], this.moves[L-6]) &&
return false;
}
+ // Is game over ? And if yes, what is the score ?
checkGameOver()
{
if (this.checkRepetition())
this.shouldReturn = false;
const maxeval = VariantRules.INFINITY;
const color = this.turn;
- let moves1 = this.getAllValidMoves();
+ // Some variants may show a bigger moves list to the human (Switching),
+ // thus the argument "computer" below (which is generally ignored)
+ let moves1 = this.getAllValidMoves("computer");
// Can I mate in 1 ? (for Magnetic & Extinction)
for (let i of _.shuffle(_.range(moves1.length)))
for (let i=0; i<moves1.length; i++)
{
moves1[i].eval = (color=="w" ? -1 : 1) * maxeval; //very low, I'm checkmated
- let eval2 = (color=="w" ? 1 : -1) * maxeval; //initialized with checkmate value
this.play(moves1[i]);
- // Second half-move:
- 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() == "1/2")
- eval2 = 0;
- for (let j=0; j<moves2.length; j++)
+ let eval2 = undefined;
+ if (this.atLeastOneMove())
{
- this.play(moves2[j]);
- let evalPos = this.evalPosition();
- if ((color == "w" && evalPos < eval2) || (color=="b" && evalPos > eval2))
- eval2 = evalPos;
- this.undo(moves2[j]);
+ eval2 = (color=="w" ? 1 : -1) * maxeval; //initialized with checkmate value
+ // Second half-move:
+ let moves2 = this.getAllValidMoves("computer");
+ for (let j=0; j<moves2.length; j++)
+ {
+ this.play(moves2[j]);
+ let evalPos = undefined;
+ if (this.atLeastOneMove())
+ evalPos = this.evalPosition()
+ else
+ {
+ // Work with scores for Loser variant
+ const score = this.checkGameEnd();
+ evalPos = (score=="1/2" ? 0 : (score=="1-0" ? 1 : -1) * maxeval);
+ }
+ if ((color == "w" && evalPos < eval2) || (color=="b" && evalPos > eval2))
+ eval2 = evalPos;
+ this.undo(moves2[j]);
+ }
}
- if ((color=="w" && eval2 > moves1[i].eval) || (color=="b" && eval2 < moves1[i].eval))
+ else
+ {
+ const score = this.checkGameEnd();
+ eval2 = (score=="1/2" ? 0 : (score=="1-0" ? 1 : -1) * maxeval);
+ }
+ if ((color=="w" && eval2 > moves1[i].eval)
+ || (color=="b" && eval2 < moves1[i].eval))
+ {
moves1[i].eval = eval2;
+ }
this.undo(moves1[i]);
}
moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); });
+ //console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; }));
let candidates = [0]; //indices of candidates moves
for (let j=1; j<moves1.length && moves1[j].eval == moves1[0].eval; j++)
}
else
return currentBest;
+ //console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; }));
candidates = [0];
for (let j=1; j<moves1.length && moves1[j].eval == moves1[0].eval; j++)
candidates.push(j);
-// console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; }));
return moves1[_.sample(candidates, 1)];
}
{
switch (this.checkGameEnd())
{
- case "1/2": return 0;
- default: return color=="w" ? -maxeval : maxeval;
+ case "1/2":
+ return 0;
+ default:
+ const score = this.checkGameEnd();
+ return (score=="1/2" ? 0 : (score=="1-0" ? 1 : -1) * maxeval);
}
}
if (depth == 0)
return this.evalPosition();
- const moves = this.getAllValidMoves();
+ const moves = this.getAllValidMoves("computer");
let v = color=="w" ? -maxeval : maxeval;
if (color == "w")
{
////////////
// FEN utils
- // Overridable..
+ // Setup the initial random (assymetric) position
static GenRandInitFen()
{
let pieces = [new Array(8), new Array(8)];
return this.getBaseFen() + " " + this.getFlagsFen();
}
+ // Position part of the FEN string
getBaseFen()
{
let fen = "";
return fen;
}
- // Overridable..
+ // Flags part of the FEN string
getFlagsFen()
{
let fen = "";
for (let i of ['w','b'])
{
for (let j=0; j<2; j++)
- fen += this.castleFlags[i][j] ? '1' : '0';
+ fen += (this.castleFlags[i][j] ? '1' : '0');
}
return fen;
}
// Context: just before move is played, turn hasn't changed
getNotation(move)
{
- if (move.appear.length == 2 && move.appear[0].p == VariantRules.KING)
- {
- // Castle
- if (move.end.y < move.start.y)
- return "0-0-0";
- else
- return "0-0";
- }
+ if (move.appear.length == 2 && move.appear[0].p == VariantRules.KING) //castle
+ return (move.end.y < move.start.y ? "0-0-0" : "0-0");
// Translate final square
const finalSquare =
// The score is already computed when calling this function
getPGN(mycolor, score, fenStart, mode)
{
+ const zeroPad = x => { return (x<10 ? "0" : "") + x; };
let pgn = "";
pgn += '[Site "vchess.club"]<br>';
const d = new Date();
const opponent = mode=="human" ? "Anonymous" : "Computer";
pgn += '[Variant "' + variant + '"]<br>';
- pgn += '[Date "' + d.getFullYear() + '-' + (d.getMonth()+1) + '-' + d.getDate() + '"]<br>';
+ pgn += '[Date "' + d.getFullYear() + '-' + (d.getMonth()+1) +
+ '-' + zeroPad(d.getDate()) + '"]<br>';
pgn += '[White "' + (mycolor=='w'?'Myself':opponent) + '"]<br>';
pgn += '[Black "' + (mycolor=='b'?'Myself':opponent) + '"]<br>';
- pgn += '[Fen "' + fenStart + '"]<br>';
+ pgn += '[FenStart "' + fenStart + '"]<br>';
+ pgn += '[Fen "' + this.getFen() + '"]<br>';
pgn += '[Result "' + score + '"]<br><br>';
// Standard PGN
pgn += ((i/2)+1) + ".";
pgn += this.moves[i].notation[0] + " ";
}
- pgn += score + "<br><br>";
+ pgn += "<br><br>";
// "Complete moves" PGN (helping in ambiguous cases)
for (let i=0; i<this.moves.length; i++)
pgn += ((i/2)+1) + ".";
pgn += this.moves[i].notation[1] + " ";
}
- pgn += score;
return pgn;
}
projects / vchess.git / blobdiff