import { ArrayFun } from "@/utils/array";
import { randInt, shuffle } from "@/utils/alea";
-export const PiPo = class PiPo //Piece+Position
-{
+export const PiPo = class PiPo {
+ //Piece+Position
// o: {piece[p], color[c], posX[x], posY[y]}
- constructor(o)
- {
+ constructor(o) {
this.p = o.p;
this.c = o.c;
this.x = o.x;
this.y = o.y;
}
-}
+};
// TODO: for animation, moves should contains "moving" and "fading" maybe...
-export const Move = class Move
-{
+export const Move = class Move {
// o: {appear, vanish, [start,] [end,]}
// appear,vanish = arrays of PiPo
// start,end = coordinates to apply to trigger move visually (think castle)
- constructor(o)
- {
+ constructor(o) {
this.appear = o.appear;
this.vanish = o.vanish;
- this.start = !!o.start ? o.start : {x:o.vanish[0].x, y:o.vanish[0].y};
- this.end = !!o.end ? o.end : {x:o.appear[0].x, y:o.appear[0].y};
+ this.start = o.start ? o.start : { x: o.vanish[0].x, y: o.vanish[0].y };
+ this.end = o.end ? o.end : { x: o.appear[0].x, y: o.appear[0].y };
}
-}
+};
// NOTE: x coords = top to bottom; y = left to right (from white player perspective)
-export const ChessRules = class ChessRules
-{
+export const ChessRules = class ChessRules {
//////////////
// MISC UTILS
- static get HasFlags() { return true; } //some variants don't have flags
+ static get HasFlags() {
+ return true;
+ } //some variants don't have flags
- static get HasEnpassant() { return true; } //some variants don't have ep.
+ static get HasEnpassant() {
+ return true;
+ } //some variants don't have ep.
// Path to pieces
- static getPpath(b)
- {
+ static getPpath(b) {
return b; //usual pieces in pieces/ folder
}
// Turn "wb" into "B" (for FEN)
- static board2fen(b)
- {
- return (b[0]=='w' ? b[1].toUpperCase() : b[1]);
+ static board2fen(b) {
+ return b[0] == "w" ? b[1].toUpperCase() : b[1];
}
// Turn "p" into "bp" (for board)
- static fen2board(f)
- {
- return (f.charCodeAt()<=90 ? "w"+f.toLowerCase() : "b"+f);
+ static fen2board(f) {
+ return f.charCodeAt() <= 90 ? "w" + f.toLowerCase() : "b" + f;
}
// Check if FEN describe a board situation correctly
- static IsGoodFen(fen)
- {
+ static IsGoodFen(fen) {
const fenParsed = V.ParseFen(fen);
// 1) Check position
- if (!V.IsGoodPosition(fenParsed.position))
- return false;
+ if (!V.IsGoodPosition(fenParsed.position)) return false;
// 2) Check turn
- if (!fenParsed.turn || !V.IsGoodTurn(fenParsed.turn))
- return false;
+ if (!fenParsed.turn || !V.IsGoodTurn(fenParsed.turn)) return false;
// 3) Check moves count
if (!fenParsed.movesCount || !(parseInt(fenParsed.movesCount) >= 0))
return false;
if (V.HasFlags && (!fenParsed.flags || !V.IsGoodFlags(fenParsed.flags)))
return false;
// 5) Check enpassant
- if (V.HasEnpassant &&
- (!fenParsed.enpassant || !V.IsGoodEnpassant(fenParsed.enpassant)))
- {
+ if (
+ V.HasEnpassant &&
+ (!fenParsed.enpassant || !V.IsGoodEnpassant(fenParsed.enpassant))
+ ) {
return false;
}
return true;
}
// Is position part of the FEN a priori correct?
- static IsGoodPosition(position)
- {
- if (position.length == 0)
- return false;
+ static IsGoodPosition(position) {
+ if (position.length == 0) return false;
const rows = position.split("/");
- if (rows.length != V.size.x)
- return false;
- for (let row of rows)
- {
+ if (rows.length != V.size.x) return false;
+ for (let row of rows) {
let sumElts = 0;
- for (let i=0; i<row.length; i++)
- {
- if (V.PIECES.includes(row[i].toLowerCase()))
- sumElts++;
- else
- {
+ for (let i = 0; i < row.length; i++) {
+ if (V.PIECES.includes(row[i].toLowerCase())) sumElts++;
+ else {
const num = parseInt(row[i]);
- if (isNaN(num))
- return false;
+ if (isNaN(num)) return false;
sumElts += num;
}
}
- if (sumElts != V.size.y)
- return false;
+ if (sumElts != V.size.y) return false;
}
return true;
}
// For FEN checking
- static IsGoodTurn(turn)
- {
- return ["w","b"].includes(turn);
+ static IsGoodTurn(turn) {
+ return ["w", "b"].includes(turn);
}
// For FEN checking
- static IsGoodFlags(flags)
- {
+ static IsGoodFlags(flags) {
return !!flags.match(/^[01]{4,4}$/);
}
- static IsGoodEnpassant(enpassant)
- {
- if (enpassant != "-")
- {
- const ep = V.SquareToCoords(fenParsed.enpassant);
- if (isNaN(ep.x) || !V.OnBoard(ep))
- return false;
+ static IsGoodEnpassant(enpassant) {
+ if (enpassant != "-") {
+ const ep = V.SquareToCoords(enpassant);
+ if (isNaN(ep.x) || !V.OnBoard(ep)) return false;
}
return true;
}
// 3 --> d (column number to letter)
- static CoordToColumn(colnum)
- {
+ static CoordToColumn(colnum) {
return String.fromCharCode(97 + colnum);
}
// d --> 3 (column letter to number)
- static ColumnToCoord(column)
- {
+ static ColumnToCoord(column) {
return column.charCodeAt(0) - 97;
}
// a4 --> {x:3,y:0}
- static SquareToCoords(sq)
- {
+ static SquareToCoords(sq) {
return {
// NOTE: column is always one char => max 26 columns
// row is counted from black side => subtraction
}
// {x:0,y:4} --> e8
- static CoordsToSquare(coords)
- {
+ static CoordsToSquare(coords) {
return V.CoordToColumn(coords.y) + (V.size.x - coords.x);
}
// Aggregates flags into one object
- aggregateFlags()
- {
+ aggregateFlags() {
return this.castleFlags;
}
// Reverse operation
- disaggregateFlags(flags)
- {
+ disaggregateFlags(flags) {
this.castleFlags = flags;
}
// En-passant square, if any
- getEpSquare(moveOrSquare)
- {
- if (!moveOrSquare)
- return undefined;
- if (typeof moveOrSquare === "string")
- {
+ getEpSquare(moveOrSquare) {
+ if (!moveOrSquare) return undefined;
+ if (typeof moveOrSquare === "string") {
const square = moveOrSquare;
- if (square == "-")
- return undefined;
+ if (square == "-") return undefined;
return V.SquareToCoords(square);
}
// Argument is a move:
const move = moveOrSquare;
- const [sx,sy,ex] = [move.start.x,move.start.y,move.end.x];
+ const [sx, sy, ex] = [move.start.x, move.start.y, move.end.x];
// NOTE: next conditions are first for Atomic, and last for Checkered
- if (move.appear.length > 0 && Math.abs(sx - ex) == 2
- && move.appear[0].p == V.PAWN && ["w","b"].includes(move.appear[0].c))
- {
+ if (
+ move.appear.length > 0 &&
+ Math.abs(sx - ex) == 2 &&
+ move.appear[0].p == V.PAWN &&
+ ["w", "b"].includes(move.appear[0].c)
+ ) {
return {
- x: (sx + ex)/2,
+ x: (sx + ex) / 2,
y: sy
};
}
}
// Can thing on square1 take thing on square2
- canTake([x1,y1], [x2,y2])
- {
- return this.getColor(x1,y1) !== this.getColor(x2,y2);
+ canTake([x1, y1], [x2, y2]) {
+ return this.getColor(x1, y1) !== this.getColor(x2, y2);
}
// Is (x,y) on the chessboard?
- static OnBoard(x,y)
- {
- return (x>=0 && x<V.size.x && y>=0 && y<V.size.y);
+ static OnBoard(x, y) {
+ return x >= 0 && x < V.size.x && y >= 0 && y < V.size.y;
}
// Used in interface: 'side' arg == player color
- canIplay(side, [x,y])
- {
- return (this.turn == side && this.getColor(x,y) == side);
+ canIplay(side, [x, y]) {
+ return this.turn == side && this.getColor(x, y) == side;
}
// On which squares is color under check ? (for interface)
- getCheckSquares(color)
- {
+ getCheckSquares(color) {
return this.isAttacked(this.kingPos[color], [V.GetOppCol(color)])
? [JSON.parse(JSON.stringify(this.kingPos[color]))] //need to duplicate!
: [];
// FEN UTILS
// Setup the initial random (assymetric) position
- static GenRandInitFen()
- {
- let pieces = { "w": new Array(8), "b": new Array(8) };
+ 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"])
- {
+ for (let c of ["w", "b"]) {
let positions = ArrayFun.range(8);
// Get random squares for bishops
let randIndex_tmp = 2 * randInt(4) + 1;
const bishop2Pos = positions[randIndex_tmp];
// Remove chosen squares
- positions.splice(Math.max(randIndex,randIndex_tmp), 1);
- positions.splice(Math.min(randIndex,randIndex_tmp), 1);
+ positions.splice(Math.max(randIndex, randIndex_tmp), 1);
+ positions.splice(Math.min(randIndex, randIndex_tmp), 1);
// Get random squares for knights
randIndex = randInt(6);
const rook2Pos = positions[2];
// 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';
+ 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("") +
+ return (
+ pieces["b"].join("") +
"/pppppppp/8/8/8/8/PPPPPPPP/" +
pieces["w"].join("").toUpperCase() +
- " w 0 1111 -"; //add turn + flags + enpassant
+ " w 0 1111 -"
+ ); //add turn + flags + enpassant
}
// "Parse" FEN: just return untransformed string data
- static ParseFen(fen)
- {
+ static ParseFen(fen) {
const fenParts = fen.split(" ");
- let res =
- {
+ let res = {
position: fenParts[0],
turn: fenParts[1],
- movesCount: fenParts[2],
+ movesCount: fenParts[2]
};
let nextIdx = 3;
- if (V.HasFlags)
- Object.assign(res, {flags: fenParts[nextIdx++]});
- if (V.HasEnpassant)
- Object.assign(res, {enpassant: fenParts[nextIdx]});
+ if (V.HasFlags) Object.assign(res, { flags: fenParts[nextIdx++] });
+ if (V.HasEnpassant) Object.assign(res, { enpassant: fenParts[nextIdx] });
return res;
}
// Return current fen (game state)
- getFen()
- {
- return this.getBaseFen() + " " +
- this.getTurnFen() + " " + this.movesCount +
- (V.HasFlags ? (" " + this.getFlagsFen()) : "") +
- (V.HasEnpassant ? (" " + this.getEnpassantFen()) : "");
+ getFen() {
+ return (
+ this.getBaseFen() +
+ " " +
+ this.getTurnFen() +
+ " " +
+ this.movesCount +
+ (V.HasFlags ? " " + this.getFlagsFen() : "") +
+ (V.HasEnpassant ? " " + this.getEnpassantFen() : "")
+ );
}
// Position part of the FEN string
- getBaseFen()
- {
+ getBaseFen() {
let position = "";
- for (let i=0; i<V.size.x; i++)
- {
+ for (let i = 0; i < V.size.x; i++) {
let emptyCount = 0;
- for (let j=0; j<V.size.y; j++)
- {
- if (this.board[i][j] == V.EMPTY)
- emptyCount++;
- else
- {
- if (emptyCount > 0)
- {
+ for (let j = 0; j < V.size.y; j++) {
+ if (this.board[i][j] == V.EMPTY) emptyCount++;
+ else {
+ if (emptyCount > 0) {
// Add empty squares in-between
position += emptyCount;
emptyCount = 0;
position += V.board2fen(this.board[i][j]);
}
}
- if (emptyCount > 0)
- {
+ if (emptyCount > 0) {
// "Flush remainder"
position += emptyCount;
}
- if (i < V.size.x - 1)
- position += "/"; //separate rows
+ if (i < V.size.x - 1) position += "/"; //separate rows
}
return position;
}
- getTurnFen()
- {
+ getTurnFen() {
return this.turn;
}
// Flags part of the FEN string
- getFlagsFen()
- {
+ getFlagsFen() {
let flags = "";
// Add castling flags
- for (let i of ['w','b'])
- {
- for (let j=0; j<2; j++)
- flags += (this.castleFlags[i][j] ? '1' : '0');
+ for (let i of ["w", "b"]) {
+ for (let j = 0; j < 2; j++) flags += this.castleFlags[i][j] ? "1" : "0";
}
return flags;
}
// Enpassant part of the FEN string
- getEnpassantFen()
- {
+ getEnpassantFen() {
const L = this.epSquares.length;
- if (!this.epSquares[L-1])
- return "-"; //no en-passant
- return V.CoordsToSquare(this.epSquares[L-1]);
+ if (!this.epSquares[L - 1]) return "-"; //no en-passant
+ return V.CoordsToSquare(this.epSquares[L - 1]);
}
// Turn position fen into double array ["wb","wp","bk",...]
- static GetBoard(position)
- {
+ static GetBoard(position) {
const rows = position.split("/");
let board = ArrayFun.init(V.size.x, V.size.y, "");
- for (let i=0; i<rows.length; i++)
- {
+ for (let i = 0; i < rows.length; i++) {
let j = 0;
- for (let indexInRow = 0; indexInRow < rows[i].length; indexInRow++)
- {
+ for (let indexInRow = 0; indexInRow < rows[i].length; indexInRow++) {
const character = rows[i][indexInRow];
const num = parseInt(character);
- if (!isNaN(num))
- j += num; //just shift j
- else //something at position i,j
- board[i][j++] = V.fen2board(character);
+ if (!isNaN(num)) j += num;
+ //just shift j
+ //something at position i,j
+ else board[i][j++] = V.fen2board(character);
}
}
return board;
}
// Extract (relevant) flags from fen
- setFlags(fenflags)
- {
+ setFlags(fenflags) {
// white a-castle, h-castle, black a-castle, h-castle
- this.castleFlags = {'w': [true,true], 'b': [true,true]};
- if (!fenflags)
- return;
- for (let i=0; i<4; i++)
- this.castleFlags[i < 2 ? 'w' : 'b'][i%2] = (fenflags.charAt(i) == '1');
+ this.castleFlags = { w: [true, true], b: [true, true] };
+ if (!fenflags) return;
+ for (let i = 0; i < 4; i++)
+ this.castleFlags[i < 2 ? "w" : "b"][i % 2] = fenflags.charAt(i) == "1";
}
//////////////////
// INITIALIZATION
- constructor(fen)
- {
+ constructor(fen) {
this.re_init(fen);
}
// Fen string fully describes the game state
- re_init(fen)
- {
+ re_init(fen) {
const fenParsed = V.ParseFen(fen);
this.board = V.GetBoard(fenParsed.position);
this.turn = fenParsed.turn[0]; //[0] to work with MarseilleRules
}
// Scan board for kings and rooks positions
- scanKingsRooks(fen)
- {
- 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]}; //squares of white and black king
+ scanKingsRooks(fen) {
+ 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] }; //squares of white and black king
const fenRows = V.ParseFen(fen).position.split("/");
- for (let i=0; i<fenRows.length; i++)
- {
+ for (let i = 0; i < fenRows.length; i++) {
let k = 0; //column index on board
- for (let j=0; j<fenRows[i].length; j++)
- {
- switch (fenRows[i].charAt(j))
- {
- case 'k':
- this.kingPos['b'] = [i,k];
- this.INIT_COL_KING['b'] = k;
+ for (let j = 0; j < fenRows[i].length; j++) {
+ switch (fenRows[i].charAt(j)) {
+ case "k":
+ this.kingPos["b"] = [i, k];
+ this.INIT_COL_KING["b"] = k;
break;
- case 'K':
- this.kingPos['w'] = [i,k];
- this.INIT_COL_KING['w'] = k;
+ case "K":
+ this.kingPos["w"] = [i, k];
+ this.INIT_COL_KING["w"] = k;
break;
- case 'r':
- if (this.INIT_COL_ROOK['b'][0] < 0)
- this.INIT_COL_ROOK['b'][0] = k;
- else
- this.INIT_COL_ROOK['b'][1] = k;
+ case "r":
+ if (this.INIT_COL_ROOK["b"][0] < 0) this.INIT_COL_ROOK["b"][0] = k;
+ else this.INIT_COL_ROOK["b"][1] = k;
break;
- case 'R':
- if (this.INIT_COL_ROOK['w'][0] < 0)
- this.INIT_COL_ROOK['w'][0] = k;
- else
- this.INIT_COL_ROOK['w'][1] = k;
+ case "R":
+ if (this.INIT_COL_ROOK["w"][0] < 0) this.INIT_COL_ROOK["w"][0] = k;
+ else this.INIT_COL_ROOK["w"][1] = k;
break;
- default:
+ default: {
const num = parseInt(fenRows[i].charAt(j));
- if (!isNaN(num))
- k += (num-1);
+ if (!isNaN(num)) k += num - 1;
+ }
}
k++;
}
}
// Some additional variables from FEN (variant dependant)
- setOtherVariables(fen)
- {
+ setOtherVariables(fen) {
// Set flags and enpassant:
const parsedFen = V.ParseFen(fen);
- if (V.HasFlags)
- this.setFlags(parsedFen.flags);
- if (V.HasEnpassant)
- {
- const epSq = parsedFen.enpassant != "-"
- ? V.SquareToCoords(parsedFen.enpassant)
- : undefined;
- this.epSquares = [ epSq ];
+ if (V.HasFlags) this.setFlags(parsedFen.flags);
+ if (V.HasEnpassant) {
+ const epSq =
+ parsedFen.enpassant != "-"
+ ? V.SquareToCoords(parsedFen.enpassant)
+ : undefined;
+ this.epSquares = [epSq];
}
// Search for king and rooks positions:
this.scanKingsRooks(fen);
/////////////////////
// GETTERS & SETTERS
- static get size()
- {
- return {x:8, y:8};
+ static get size() {
+ return { x: 8, y: 8 };
}
// Color of thing on suqare (i,j). 'undefined' if square is empty
- getColor(i,j)
- {
+ getColor(i, j) {
return this.board[i][j].charAt(0);
}
// Piece type on square (i,j). 'undefined' if square is empty
- getPiece(i,j)
- {
+ getPiece(i, j) {
return this.board[i][j].charAt(1);
}
// Get opponent color
- static GetOppCol(color)
- {
- return (color=="w" ? "b" : "w");
+ static GetOppCol(color) {
+ return color == "w" ? "b" : "w";
}
// Pieces codes (for a clearer code)
- static get PAWN() { return 'p'; }
- static get ROOK() { return 'r'; }
- static get KNIGHT() { return 'n'; }
- static get BISHOP() { return 'b'; }
- static get QUEEN() { return 'q'; }
- static get KING() { return 'k'; }
+ static get PAWN() {
+ return "p";
+ }
+ static get ROOK() {
+ return "r";
+ }
+ static get KNIGHT() {
+ return "n";
+ }
+ static get BISHOP() {
+ return "b";
+ }
+ static get QUEEN() {
+ return "q";
+ }
+ static get KING() {
+ return "k";
+ }
// For FEN checking:
- static get PIECES()
- {
- return [V.PAWN,V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN,V.KING];
+ static get PIECES() {
+ return [V.PAWN, V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN, V.KING];
}
// Empty square
- static get EMPTY() { return ""; }
+ static get EMPTY() {
+ return "";
+ }
// Some pieces movements
- static get steps()
- {
+ static get steps() {
return {
- 'r': [ [-1,0],[1,0],[0,-1],[0,1] ],
- 'n': [ [-1,-2],[-1,2],[1,-2],[1,2],[-2,-1],[-2,1],[2,-1],[2,1] ],
- 'b': [ [-1,-1],[-1,1],[1,-1],[1,1] ],
+ r: [
+ [-1, 0],
+ [1, 0],
+ [0, -1],
+ [0, 1]
+ ],
+ n: [
+ [-1, -2],
+ [-1, 2],
+ [1, -2],
+ [1, 2],
+ [-2, -1],
+ [-2, 1],
+ [2, -1],
+ [2, 1]
+ ],
+ b: [
+ [-1, -1],
+ [-1, 1],
+ [1, -1],
+ [1, 1]
+ ]
};
}
// MOVES GENERATION
// All possible moves from selected square (assumption: color is OK)
- getPotentialMovesFrom([x,y])
- {
- switch (this.getPiece(x,y))
- {
+ getPotentialMovesFrom([x, y]) {
+ switch (this.getPiece(x, y)) {
case V.PAWN:
- return this.getPotentialPawnMoves([x,y]);
+ return this.getPotentialPawnMoves([x, y]);
case V.ROOK:
- return this.getPotentialRookMoves([x,y]);
+ return this.getPotentialRookMoves([x, y]);
case V.KNIGHT:
- return this.getPotentialKnightMoves([x,y]);
+ return this.getPotentialKnightMoves([x, y]);
case V.BISHOP:
- return this.getPotentialBishopMoves([x,y]);
+ return this.getPotentialBishopMoves([x, y]);
case V.QUEEN:
- return this.getPotentialQueenMoves([x,y]);
+ return this.getPotentialQueenMoves([x, y]);
case V.KING:
- return this.getPotentialKingMoves([x,y]);
+ return this.getPotentialKingMoves([x, y]);
}
+ return []; //never reached
}
// Build a regular move from its initial and destination squares.
// tr: transformation
- getBasicMove([sx,sy], [ex,ey], tr)
- {
+ getBasicMove([sx, sy], [ex, ey], tr) {
let mv = new Move({
appear: [
new PiPo({
x: ex,
y: ey,
- c: !!tr ? tr.c : this.getColor(sx,sy),
- p: !!tr ? tr.p : this.getPiece(sx,sy)
+ c: tr ? tr.c : this.getColor(sx, sy),
+ p: tr ? tr.p : this.getPiece(sx, sy)
})
],
vanish: [
new PiPo({
x: sx,
y: sy,
- c: this.getColor(sx,sy),
- p: this.getPiece(sx,sy)
+ c: this.getColor(sx, sy),
+ p: this.getPiece(sx, sy)
})
]
});
// The opponent piece disappears if we take it
- if (this.board[ex][ey] != V.EMPTY)
- {
+ if (this.board[ex][ey] != V.EMPTY) {
mv.vanish.push(
new PiPo({
x: ex,
y: ey,
- c: this.getColor(ex,ey),
- p: this.getPiece(ex,ey)
+ c: this.getColor(ex, ey),
+ p: this.getPiece(ex, ey)
})
);
}
// Generic method to find possible moves of non-pawn pieces:
// "sliding or jumping"
- getSlideNJumpMoves([x,y], steps, oneStep)
- {
- const color = this.getColor(x,y);
+ getSlideNJumpMoves([x, y], steps, oneStep) {
let moves = [];
- outerLoop:
- for (let step of steps)
- {
+ outerLoop: for (let step of steps) {
let i = x + step[0];
let j = y + step[1];
- while (V.OnBoard(i,j) && this.board[i][j] == V.EMPTY)
- {
- moves.push(this.getBasicMove([x,y], [i,j]));
- if (oneStep !== undefined)
- continue outerLoop;
+ while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
+ moves.push(this.getBasicMove([x, y], [i, j]));
+ if (oneStep !== undefined) continue outerLoop;
i += step[0];
j += step[1];
}
- if (V.OnBoard(i,j) && this.canTake([x,y], [i,j]))
- moves.push(this.getBasicMove([x,y], [i,j]));
+ if (V.OnBoard(i, j) && 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 ?
- getPotentialPawnMoves([x,y])
- {
+ getPotentialPawnMoves([x, y]) {
const color = this.turn;
let moves = [];
- const [sizeX,sizeY] = [V.size.x,V.size.y];
- const shiftX = (color == "w" ? -1 : 1);
- const firstRank = (color == 'w' ? sizeX-1 : 0);
- const startRank = (color == "w" ? sizeX-2 : 1);
- const lastRank = (color == "w" ? 0 : sizeX-1);
- const pawnColor = this.getColor(x,y); //can be different for checkered
+ const [sizeX, sizeY] = [V.size.x, V.size.y];
+ const shiftX = color == "w" ? -1 : 1;
+ const firstRank = color == "w" ? sizeX - 1 : 0;
+ const startRank = color == "w" ? sizeX - 2 : 1;
+ const lastRank = color == "w" ? 0 : sizeX - 1;
+ const pawnColor = this.getColor(x, y); //can be different for checkered
// NOTE: next condition is generally true (no pawn on last rank)
- if (x+shiftX >= 0 && x+shiftX < sizeX)
- {
- const finalPieces = x + shiftX == lastRank
- ? [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN]
- : [V.PAWN]
+ if (x + shiftX >= 0 && x + shiftX < sizeX) {
+ const finalPieces =
+ x + shiftX == lastRank
+ ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN]
+ : [V.PAWN];
// One square forward
- if (this.board[x+shiftX][y] == V.EMPTY)
- {
- for (let piece of finalPieces)
- {
- moves.push(this.getBasicMove([x,y], [x+shiftX,y],
- {c:pawnColor,p:piece}));
+ if (this.board[x + shiftX][y] == V.EMPTY) {
+ for (let piece of finalPieces) {
+ moves.push(
+ this.getBasicMove([x, y], [x + shiftX, y], {
+ c: pawnColor,
+ p: piece
+ })
+ );
}
// Next condition because pawns on 1st rank can generally jump
- if ([startRank,firstRank].includes(x)
- && this.board[x+2*shiftX][y] == V.EMPTY)
- {
+ if (
+ [startRank, firstRank].includes(x) &&
+ this.board[x + 2 * shiftX][y] == V.EMPTY
+ ) {
// Two squares jump
- moves.push(this.getBasicMove([x,y], [x+2*shiftX,y]));
+ moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
}
}
// Captures
- for (let shiftY of [-1,1])
- {
- if (y + shiftY >= 0 && y + shiftY < sizeY
- && this.board[x+shiftX][y+shiftY] != V.EMPTY
- && this.canTake([x,y], [x+shiftX,y+shiftY]))
- {
- for (let piece of finalPieces)
- {
- moves.push(this.getBasicMove([x,y], [x+shiftX,y+shiftY],
- {c:pawnColor,p:piece}));
+ for (let shiftY of [-1, 1]) {
+ if (
+ y + shiftY >= 0 &&
+ y + shiftY < sizeY &&
+ this.board[x + shiftX][y + shiftY] != V.EMPTY &&
+ this.canTake([x, y], [x + shiftX, y + shiftY])
+ ) {
+ for (let piece of finalPieces) {
+ moves.push(
+ this.getBasicMove([x, y], [x + shiftX, y + shiftY], {
+ c: pawnColor,
+ p: piece
+ })
+ );
}
}
}
}
- if (V.HasEnpassant)
- {
+ if (V.HasEnpassant) {
// En passant
const Lep = this.epSquares.length;
- const epSquare = this.epSquares[Lep-1]; //always at least one element
- if (!!epSquare && epSquare.x == x+shiftX && Math.abs(epSquare.y - y) == 1)
- {
- let enpassantMove = this.getBasicMove([x,y], [epSquare.x,epSquare.y]);
+ const epSquare = this.epSquares[Lep - 1]; //always at least one element
+ if (
+ !!epSquare &&
+ epSquare.x == x + shiftX &&
+ Math.abs(epSquare.y - y) == 1
+ ) {
+ let enpassantMove = this.getBasicMove([x, y], [epSquare.x, epSquare.y]);
enpassantMove.vanish.push({
x: x,
y: epSquare.y,
- p: 'p',
- c: this.getColor(x,epSquare.y)
+ p: "p",
+ c: this.getColor(x, epSquare.y)
});
moves.push(enpassantMove);
}
}
// What are the rook moves from square x,y ?
- getPotentialRookMoves(sq)
- {
+ getPotentialRookMoves(sq) {
return this.getSlideNJumpMoves(sq, V.steps[V.ROOK]);
}
// What are the knight moves from square x,y ?
- getPotentialKnightMoves(sq)
- {
+ getPotentialKnightMoves(sq) {
return this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT], "oneStep");
}
// What are the bishop moves from square x,y ?
- getPotentialBishopMoves(sq)
- {
+ getPotentialBishopMoves(sq) {
return this.getSlideNJumpMoves(sq, V.steps[V.BISHOP]);
}
// What are the queen moves from square x,y ?
- getPotentialQueenMoves(sq)
- {
- return this.getSlideNJumpMoves(sq,
- V.steps[V.ROOK].concat(V.steps[V.BISHOP]));
+ getPotentialQueenMoves(sq) {
+ return this.getSlideNJumpMoves(
+ sq,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP])
+ );
}
// What are the king moves from square x,y ?
- getPotentialKingMoves(sq)
- {
+ getPotentialKingMoves(sq) {
// Initialize with normal moves
- let moves = this.getSlideNJumpMoves(sq,
- V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
+ let moves = this.getSlideNJumpMoves(
+ sq,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
+ "oneStep"
+ );
return moves.concat(this.getCastleMoves(sq));
}
- getCastleMoves([x,y])
- {
- const c = this.getColor(x,y);
- if (x != (c=="w" ? V.size.x-1 : 0) || y != this.INIT_COL_KING[c])
+ getCastleMoves([x, y]) {
+ const c = this.getColor(x, y);
+ if (x != (c == "w" ? V.size.x - 1 : 0) || y != this.INIT_COL_KING[c])
return []; //x isn't first rank, or king has moved (shortcut)
// Castling ?
const oppCol = V.GetOppCol(c);
let moves = [];
let i = 0;
- const finalSquares = [ [2,3], [V.size.y-2,V.size.y-3] ]; //king, then rook
- castlingCheck:
- for (let castleSide=0; castleSide < 2; castleSide++) //large, then small
- {
- if (!this.castleFlags[c][castleSide])
- continue;
+ const finalSquares = [
+ [2, 3],
+ [V.size.y - 2, V.size.y - 3]
+ ]; //king, then rook
+ castlingCheck: for (
+ let castleSide = 0;
+ castleSide < 2;
+ castleSide++ //large, then small
+ ) {
+ if (!this.castleFlags[c][castleSide]) continue;
// If this code is reached, rooks and king are on initial position
// Nothing on the path of the king ? (and no checks)
const finDist = finalSquares[castleSide][0] - y;
let step = finDist / Math.max(1, Math.abs(finDist));
i = y;
- do
- {
- 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)))))
- {
+ do {
+ 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))))
+ ) {
continue castlingCheck;
}
i += step;
- }
- while (i!=finalSquares[castleSide][0]);
+ } while (i != finalSquares[castleSide][0]);
// Nothing on the path to the rook?
- step = (castleSide == 0 ? -1 : 1);
- for (i = y + step; i != this.INIT_COL_ROOK[c][castleSide]; i += step)
- {
- if (this.board[x][i] != V.EMPTY)
- continue castlingCheck;
+ step = castleSide == 0 ? -1 : 1;
+ for (i = y + step; i != this.INIT_COL_ROOK[c][castleSide]; i += step) {
+ if (this.board[x][i] != V.EMPTY) continue castlingCheck;
}
const rookPos = this.INIT_COL_ROOK[c][castleSide];
// Nothing on final squares, except maybe king and castling rook?
- for (i=0; i<2; i++)
- {
- if (this.board[x][finalSquares[castleSide][i]] != V.EMPTY &&
- this.getPiece(x,finalSquares[castleSide][i]) != V.KING &&
- finalSquares[castleSide][i] != rookPos)
- {
+ for (i = 0; i < 2; i++) {
+ if (
+ this.board[x][finalSquares[castleSide][i]] != V.EMPTY &&
+ this.getPiece(x, finalSquares[castleSide][i]) != V.KING &&
+ finalSquares[castleSide][i] != rookPos
+ ) {
continue castlingCheck;
}
}
// If this code is reached, castle is valid
- moves.push( new Move({
- appear: [
- new PiPo({x:x,y:finalSquares[castleSide][0],p:V.KING,c:c}),
- new PiPo({x:x,y:finalSquares[castleSide][1],p:V.ROOK,c:c})],
- vanish: [
- new PiPo({x:x,y:y,p:V.KING,c:c}),
- new PiPo({x:x,y:rookPos,p:V.ROOK,c:c})],
- end: Math.abs(y - rookPos) <= 2
- ? {x:x, y:rookPos}
- : {x:x, y:y + 2 * (castleSide==0 ? -1 : 1)}
- }) );
+ moves.push(
+ new Move({
+ appear: [
+ new PiPo({ x: x, y: finalSquares[castleSide][0], p: V.KING, c: c }),
+ new PiPo({ x: x, y: finalSquares[castleSide][1], p: V.ROOK, c: c })
+ ],
+ vanish: [
+ new PiPo({ x: x, y: y, p: V.KING, c: c }),
+ new PiPo({ x: x, y: rookPos, p: V.ROOK, c: c })
+ ],
+ end:
+ Math.abs(y - rookPos) <= 2
+ ? { x: x, y: rookPos }
+ : { x: x, y: y + 2 * (castleSide == 0 ? -1 : 1) }
+ })
+ );
}
return moves;
// MOVES VALIDATION
// For the interface: possible moves for the current turn from square sq
- getPossibleMovesFrom(sq)
- {
- return this.filterValid( this.getPotentialMovesFrom(sq) );
+ getPossibleMovesFrom(sq) {
+ return this.filterValid(this.getPotentialMovesFrom(sq));
}
// TODO: promotions (into R,B,N,Q) should be filtered only once
- filterValid(moves)
- {
- if (moves.length == 0)
- return [];
+ filterValid(moves) {
+ if (moves.length == 0) return [];
const color = this.turn;
return moves.filter(m => {
this.play(m);
// Search for all valid moves considering current turn
// (for engine and game end)
- getAllValidMoves()
- {
+ getAllValidMoves() {
const color = this.turn;
const oppCol = V.GetOppCol(color);
let potentialMoves = [];
- for (let i=0; i<V.size.x; i++)
- {
- for (let j=0; j<V.size.y; j++)
- {
+ for (let i = 0; i < V.size.x; i++) {
+ for (let j = 0; j < V.size.y; j++) {
// 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]));
+ if (this.board[i][j] != V.EMPTY && this.getColor(i, j) != oppCol) {
+ Array.prototype.push.apply(
+ potentialMoves,
+ this.getPotentialMovesFrom([i, j])
+ );
}
}
}
}
// Stop at the first move found
- atLeastOneMove()
- {
+ atLeastOneMove() {
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 (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) != oppCol) {
+ const moves = this.getPotentialMovesFrom([i, j]);
+ if (moves.length > 0) {
+ for (let k = 0; k < moves.length; k++) {
+ if (this.filterValid([moves[k]]).length > 0) return true;
}
}
}
}
// Check if pieces of color in 'colors' are attacking (king) on square x,y
- isAttacked(sq, colors)
- {
- 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));
+ isAttacked(sq, colors) {
+ 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 'colors' pawns ?
- isAttackedByPawn([x,y], colors)
- {
- for (let c of colors)
- {
- let pawnShift = (c=="w" ? 1 : -1);
- if (x+pawnShift>=0 && x+pawnShift<V.size.x)
- {
- for (let i of [-1,1])
- {
- if (y+i>=0 && y+i<V.size.y && this.getPiece(x+pawnShift,y+i)==V.PAWN
- && this.getColor(x+pawnShift,y+i)==c)
- {
+ isAttackedByPawn([x, y], colors) {
+ for (let c of colors) {
+ let pawnShift = c == "w" ? 1 : -1;
+ if (x + pawnShift >= 0 && x + pawnShift < V.size.x) {
+ for (let i of [-1, 1]) {
+ if (
+ y + i >= 0 &&
+ y + i < V.size.y &&
+ this.getPiece(x + pawnShift, y + i) == V.PAWN &&
+ this.getColor(x + pawnShift, y + i) == c
+ ) {
return true;
}
}
}
// Is square x,y attacked by 'colors' rooks ?
- isAttackedByRook(sq, colors)
- {
+ isAttackedByRook(sq, colors) {
return this.isAttackedBySlideNJump(sq, colors, V.ROOK, V.steps[V.ROOK]);
}
// Is square x,y attacked by 'colors' knights ?
- isAttackedByKnight(sq, colors)
- {
- return this.isAttackedBySlideNJump(sq, colors,
- V.KNIGHT, V.steps[V.KNIGHT], "oneStep");
+ isAttackedByKnight(sq, colors) {
+ return this.isAttackedBySlideNJump(
+ sq,
+ colors,
+ V.KNIGHT,
+ V.steps[V.KNIGHT],
+ "oneStep"
+ );
}
// Is square x,y attacked by 'colors' bishops ?
- isAttackedByBishop(sq, colors)
- {
+ isAttackedByBishop(sq, colors) {
return this.isAttackedBySlideNJump(sq, colors, V.BISHOP, V.steps[V.BISHOP]);
}
// Is square x,y attacked by 'colors' queens ?
- isAttackedByQueen(sq, colors)
- {
- return this.isAttackedBySlideNJump(sq, colors, V.QUEEN,
- V.steps[V.ROOK].concat(V.steps[V.BISHOP]));
+ isAttackedByQueen(sq, colors) {
+ return this.isAttackedBySlideNJump(
+ sq,
+ colors,
+ V.QUEEN,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP])
+ );
}
// Is square x,y attacked by 'colors' king(s) ?
- isAttackedByKing(sq, colors)
- {
- return this.isAttackedBySlideNJump(sq, colors, V.KING,
- V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
+ isAttackedByKing(sq, colors) {
+ return this.isAttackedBySlideNJump(
+ sq,
+ colors,
+ V.KING,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
+ "oneStep"
+ );
}
// Generic method for non-pawn pieces ("sliding or jumping"):
// is x,y attacked by a piece of color in array 'colors' ?
- isAttackedBySlideNJump([x,y], colors, piece, steps, oneStep)
- {
- for (let step of steps)
- {
- let rx = x+step[0], ry = y+step[1];
- while (V.OnBoard(rx,ry) && this.board[rx][ry] == V.EMPTY && !oneStep)
- {
+ isAttackedBySlideNJump([x, y], colors, piece, steps, oneStep) {
+ for (let step of steps) {
+ let rx = x + step[0],
+ ry = y + step[1];
+ while (V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && !oneStep) {
rx += step[0];
ry += step[1];
}
- if (V.OnBoard(rx,ry) && this.getPiece(rx,ry) === piece
- && colors.includes(this.getColor(rx,ry)))
- {
+ if (
+ V.OnBoard(rx, ry) &&
+ this.getPiece(rx, ry) === piece &&
+ colors.includes(this.getColor(rx, ry))
+ ) {
return true;
}
}
}
// Is color under check after his move ?
- underCheck(color)
- {
+ underCheck(color) {
return this.isAttacked(this.kingPos[color], [V.GetOppCol(color)]);
}
// MOVES PLAYING
// Apply a move on board
- static PlayOnBoard(board, move)
- {
- for (let psq of move.vanish)
- board[psq.x][psq.y] = V.EMPTY;
- for (let psq of move.appear)
- board[psq.x][psq.y] = psq.c + psq.p;
+ static PlayOnBoard(board, move) {
+ for (let psq of move.vanish) board[psq.x][psq.y] = V.EMPTY;
+ for (let psq of move.appear) board[psq.x][psq.y] = psq.c + psq.p;
}
// Un-apply the played move
- static UndoOnBoard(board, move)
- {
- for (let psq of move.appear)
- board[psq.x][psq.y] = V.EMPTY;
- for (let psq of move.vanish)
- board[psq.x][psq.y] = psq.c + psq.p;
+ static UndoOnBoard(board, move) {
+ for (let psq of move.appear) board[psq.x][psq.y] = V.EMPTY;
+ for (let psq of move.vanish) board[psq.x][psq.y] = psq.c + psq.p;
}
// After move is played, update variables + flags
- updateVariables(move)
- {
+ updateVariables(move) {
let piece = undefined;
let c = undefined;
- if (move.vanish.length >= 1)
- {
+ if (move.vanish.length >= 1) {
// Usual case, something is moved
piece = move.vanish[0].p;
c = move.vanish[0].c;
- }
- else
- {
+ } else {
// Crazyhouse-like variants
piece = move.appear[0].p;
c = move.appear[0].c;
}
- if (c == "c") //if (!["w","b"].includes(c))
- {
+ if (c == "c") {
+ //if (!["w","b"].includes(c))
// 'c = move.vanish[0].c' doesn't work for Checkered
c = V.GetOppCol(this.turn);
}
- const firstRank = (c == "w" ? V.size.x-1 : 0);
+ const firstRank = c == "w" ? V.size.x - 1 : 0;
// Update king position + flags
- if (piece == V.KING && move.appear.length > 0)
- {
+ if (piece == V.KING && move.appear.length > 0) {
this.kingPos[c][0] = move.appear[0].x;
this.kingPos[c][1] = move.appear[0].y;
- if (V.HasFlags)
- this.castleFlags[c] = [false,false];
+ if (V.HasFlags) this.castleFlags[c] = [false, false];
return;
}
- if (V.HasFlags)
- {
+ if (V.HasFlags) {
// Update castling flags if rooks are moved
const oppCol = V.GetOppCol(c);
- const oppFirstRank = (V.size.x-1) - firstRank;
- if (move.start.x == firstRank //our rook moves?
- && this.INIT_COL_ROOK[c].includes(move.start.y))
- {
- const flagIdx = (move.start.y == this.INIT_COL_ROOK[c][0] ? 0 : 1);
+ const oppFirstRank = V.size.x - 1 - firstRank;
+ if (
+ move.start.x == firstRank && //our rook moves?
+ this.INIT_COL_ROOK[c].includes(move.start.y)
+ ) {
+ const flagIdx = move.start.y == this.INIT_COL_ROOK[c][0] ? 0 : 1;
this.castleFlags[c][flagIdx] = false;
- }
- else if (move.end.x == oppFirstRank //we took opponent rook?
- && this.INIT_COL_ROOK[oppCol].includes(move.end.y))
- {
- const flagIdx = (move.end.y == this.INIT_COL_ROOK[oppCol][0] ? 0 : 1);
+ } else if (
+ move.end.x == oppFirstRank && //we took opponent rook?
+ this.INIT_COL_ROOK[oppCol].includes(move.end.y)
+ ) {
+ const flagIdx = move.end.y == this.INIT_COL_ROOK[oppCol][0] ? 0 : 1;
this.castleFlags[oppCol][flagIdx] = false;
}
}
// After move is undo-ed *and flags resetted*, un-update other variables
// TODO: more symmetry, by storing flags increment in move (?!)
- unupdateVariables(move)
- {
+ unupdateVariables(move) {
// (Potentially) Reset king position
- const c = this.getColor(move.start.x,move.start.y);
- if (this.getPiece(move.start.x,move.start.y) == V.KING)
+ const c = this.getColor(move.start.x, move.start.y);
+ if (this.getPiece(move.start.x, move.start.y) == V.KING)
this.kingPos[c] = [move.start.x, move.start.y];
}
- play(move)
- {
+ play(move) {
// DEBUG:
-// if (!this.states) this.states = [];
-// const stateFen = this.getBaseFen() + this.getTurnFen() + this.getFlagsFen();
-// this.states.push(stateFen);
-
- if (V.HasFlags)
- move.flags = JSON.stringify(this.aggregateFlags()); //save flags (for undo)
- if (V.HasEnpassant)
- this.epSquares.push( this.getEpSquare(move) );
+ // if (!this.states) this.states = [];
+ // const stateFen = this.getBaseFen() + this.getTurnFen() + this.getFlagsFen();
+ // this.states.push(stateFen);
+
+ if (V.HasFlags) move.flags = JSON.stringify(this.aggregateFlags()); //save flags (for undo)
+ if (V.HasEnpassant) this.epSquares.push(this.getEpSquare(move));
V.PlayOnBoard(this.board, move);
this.turn = V.GetOppCol(this.turn);
this.movesCount++;
this.updateVariables(move);
}
- undo(move)
- {
- if (V.HasEnpassant)
- this.epSquares.pop();
- if (V.HasFlags)
- this.disaggregateFlags(JSON.parse(move.flags));
+ undo(move) {
+ if (V.HasEnpassant) this.epSquares.pop();
+ if (V.HasFlags) this.disaggregateFlags(JSON.parse(move.flags));
V.UndoOnBoard(this.board, move);
this.turn = V.GetOppCol(this.turn);
this.movesCount--;
this.unupdateVariables(move);
// DEBUG:
-// const stateFen = this.getBaseFen() + this.getTurnFen() + this.getFlagsFen();
-// if (stateFen != this.states[this.states.length-1]) debugger;
-// this.states.pop();
+ // const stateFen = this.getBaseFen() + this.getTurnFen() + this.getFlagsFen();
+ // if (stateFen != this.states[this.states.length-1]) debugger;
+ // this.states.pop();
}
///////////////
// END OF GAME
// What is the score ? (Interesting if game is over)
- getCurrentScore()
- {
- if (this.atLeastOneMove()) // game not over
+ getCurrentScore() {
+ if (this.atLeastOneMove())
+ // game not over
return "*";
// Game over
if (!this.isAttacked(this.kingPos[color], [V.GetOppCol(color)]))
return "1/2";
// OK, checkmate
- return (color == "w" ? "0-1" : "1-0");
+ return color == "w" ? "0-1" : "1-0";
}
///////////////
// ENGINE PLAY
// Pieces values
- static get VALUES()
- {
+ static get VALUES() {
return {
- 'p': 1,
- 'r': 5,
- 'n': 3,
- 'b': 3,
- 'q': 9,
- 'k': 1000
+ p: 1,
+ r: 5,
+ n: 3,
+ b: 3,
+ q: 9,
+ k: 1000
};
}
// "Checkmate" (unreachable eval)
- static get INFINITY() { return 9999; }
+ static get INFINITY() {
+ return 9999;
+ }
// At this value or above, the game is over
- static get THRESHOLD_MATE() { return V.INFINITY; }
+ static get THRESHOLD_MATE() {
+ return V.INFINITY;
+ }
// Search depth: 2 for high branching factor, 4 for small (Loser chess, eg.)
- static get SEARCH_DEPTH() { return 3; }
+ static get SEARCH_DEPTH() {
+ return 3;
+ }
// NOTE: works also for extinction chess because depth is 3...
- getComputerMove()
- {
+ getComputerMove() {
const maxeval = V.INFINITY;
const color = this.turn;
// 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");
- if (moves1.length == 0) //TODO: this situation should not happen
+ if (moves1.length == 0)
+ //TODO: this situation should not happen
return null;
// Can I mate in 1 ? (for Magnetic & Extinction)
- for (let i of shuffle(ArrayFun.range(moves1.length)))
- {
+ for (let i of shuffle(ArrayFun.range(moves1.length))) {
this.play(moves1[i]);
- let finish = (Math.abs(this.evalPosition()) >= V.THRESHOLD_MATE);
- if (!finish)
- {
+ let finish = Math.abs(this.evalPosition()) >= V.THRESHOLD_MATE;
+ if (!finish) {
const score = this.getCurrentScore();
- if (["1-0","0-1"].includes(score))
- finish = true;
+ if (["1-0", "0-1"].includes(score)) finish = true;
}
this.undo(moves1[i]);
- if (finish)
- return moves1[i];
+ if (finish) return moves1[i];
}
// Rank moves using a min-max at depth 2
- for (let i=0; i<moves1.length; i++)
- {
+ for (let i = 0; i < moves1.length; i++) {
// Initial self evaluation is very low: "I'm checkmated"
- moves1[i].eval = (color=="w" ? -1 : 1) * maxeval;
+ moves1[i].eval = (color == "w" ? -1 : 1) * maxeval;
this.play(moves1[i]);
const score1 = this.getCurrentScore();
let eval2 = undefined;
- if (score1 == "*")
- {
+ if (score1 == "*") {
// Initial enemy evaluation is very low too, for him
- eval2 = (color=="w" ? 1 : -1) * maxeval;
+ eval2 = (color == "w" ? 1 : -1) * maxeval;
// Second half-move:
let moves2 = this.getAllValidMoves("computer");
- for (let j=0; j<moves2.length; j++)
- {
+ for (let j = 0; j < moves2.length; j++) {
this.play(moves2[j]);
const score2 = this.getCurrentScore();
- const evalPos = score2 == "*"
- ? this.evalPosition()
- : (score2=="1/2" ? 0 : (score2=="1-0" ? 1 : -1) * maxeval);
- if ((color == "w" && evalPos < eval2)
- || (color=="b" && evalPos > eval2))
- {
+ let evalPos = 0; //1/2 value
+ switch (score2) {
+ case "*":
+ evalPos = this.evalPosition();
+ break;
+ case "1-0":
+ evalPos = maxeval;
+ break;
+ case "0-1":
+ evalPos = -maxeval;
+ break;
+ }
+ if (
+ (color == "w" && evalPos < eval2) ||
+ (color == "b" && evalPos > eval2)
+ ) {
eval2 = evalPos;
}
this.undo(moves2[j]);
}
- }
- else
- eval2 = (score1=="1/2" ? 0 : (score1=="1-0" ? 1 : -1) * maxeval);
- if ((color=="w" && eval2 > moves1[i].eval)
- || (color=="b" && eval2 < moves1[i].eval))
- {
+ } else eval2 = score1 == "1/2" ? 0 : (score1 == "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); });
+ moves1.sort((a, b) => {
+ return (color == "w" ? 1 : -1) * (b.eval - a.eval);
+ });
let candidates = [0]; //indices of candidates moves
- for (let j=1; j<moves1.length && moves1[j].eval == moves1[0].eval; j++)
+ for (let j = 1; j < moves1.length && moves1[j].eval == moves1[0].eval; j++)
candidates.push(j);
let currentBest = moves1[candidates[randInt(candidates.length)]];
// Skip depth 3+ if we found a checkmate (or if we are checkmated in 1...)
- if (V.SEARCH_DEPTH >= 3 && Math.abs(moves1[0].eval) < V.THRESHOLD_MATE)
- {
+ if (V.SEARCH_DEPTH >= 3 && Math.abs(moves1[0].eval) < V.THRESHOLD_MATE) {
// From here, depth >= 3: may take a while, so we control time
const timeStart = Date.now();
- for (let i=0; i<moves1.length; i++)
- {
- if (Date.now()-timeStart >= 5000) //more than 5 seconds
+ for (let i = 0; i < moves1.length; i++) {
+ if (Date.now() - timeStart >= 5000)
+ //more than 5 seconds
return currentBest; //depth 2 at least
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(V.SEARCH_DEPTH-1, -maxeval, maxeval);
+ moves1[i].eval =
+ 0.1 * moves1[i].eval +
+ 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); });
- }
- else
- return currentBest;
-// console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; }));
+ moves1.sort((a, b) => {
+ return (color == "w" ? 1 : -1) * (b.eval - a.eval);
+ });
+ } 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++)
+ for (let j = 1; j < moves1.length && moves1[j].eval == moves1[0].eval; j++)
candidates.push(j);
return moves1[candidates[randInt(candidates.length)]];
}
- alphabeta(depth, alpha, beta)
- {
+ alphabeta(depth, alpha, beta) {
const maxeval = V.INFINITY;
const color = this.turn;
const score = this.getCurrentScore();
if (score != "*")
- return (score=="1/2" ? 0 : (score=="1-0" ? 1 : -1) * maxeval);
- if (depth == 0)
- return this.evalPosition();
+ return score == "1/2" ? 0 : (score == "1-0" ? 1 : -1) * maxeval;
+ if (depth == 0) return this.evalPosition();
const moves = this.getAllValidMoves("computer");
- let v = color=="w" ? -maxeval : maxeval;
- if (color == "w")
- {
- for (let i=0; i<moves.length; i++)
- {
+ let v = color == "w" ? -maxeval : maxeval;
+ if (color == "w") {
+ for (let i = 0; i < moves.length; i++) {
this.play(moves[i]);
- v = Math.max(v, this.alphabeta(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)
- break; //beta cutoff
+ if (alpha >= beta) break; //beta cutoff
}
- }
- else //color=="b"
- {
- for (let i=0; i<moves.length; i++)
- {
+ } //color=="b"
+ else {
+ for (let i = 0; i < moves.length; i++) {
this.play(moves[i]);
- v = Math.min(v, this.alphabeta(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)
- break; //alpha cutoff
+ if (alpha >= beta) break; //alpha cutoff
}
}
return v;
}
- evalPosition()
- {
+ evalPosition() {
let evaluation = 0;
// Just count material for now
- 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)
- {
- const sign = this.getColor(i,j) == "w" ? 1 : -1;
- evaluation += sign * V.VALUES[this.getPiece(i,j)];
+ 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) {
+ const sign = this.getColor(i, j) == "w" ? 1 : -1;
+ evaluation += sign * V.VALUES[this.getPiece(i, j)];
}
}
}
// Context: just before move is played, turn hasn't changed
// TODO: un-ambiguous notation (switch on piece type, check directions...)
- getNotation(move)
- {
- if (move.appear.length == 2 && move.appear[0].p == V.KING) //castle
- return (move.end.y < move.start.y ? "0-0-0" : "0-0");
+ getNotation(move) {
+ if (move.appear.length == 2 && move.appear[0].p == V.KING)
+ //castle
+ return move.end.y < move.start.y ? "0-0-0" : "0-0";
// Translate final square
const finalSquare = V.CoordsToSquare(move.end);
const piece = this.getPiece(move.start.x, move.start.y);
- if (piece == V.PAWN)
- {
+ if (piece == V.PAWN) {
// Pawn move
let notation = "";
- if (move.vanish.length > move.appear.length)
- {
+ if (move.vanish.length > move.appear.length) {
// Capture
const startColumn = V.CoordToColumn(move.start.y);
notation = startColumn + "x" + finalSquare;
- }
- else //no capture
- notation = finalSquare;
- if (move.appear.length > 0 && move.appear[0].p != V.PAWN) //promotion
+ } //no capture
+ else notation = finalSquare;
+ if (move.appear.length > 0 && move.appear[0].p != V.PAWN)
+ //promotion
notation += "=" + move.appear[0].p.toUpperCase();
return notation;
}
-
- else
- {
- // Piece movement
- return piece.toUpperCase() +
- (move.vanish.length > move.appear.length ? "x" : "") + finalSquare;
- }
- }
-}
+ // Piece movement
+ return (
+ piece.toUpperCase() +
+ (move.vanish.length > move.appear.length ? "x" : "") +
+ finalSquare
+ );
+ }
+};
projects / vchess.git / blobdiff