2738 lines
72 KiB
JavaScript
2738 lines
72 KiB
JavaScript
/*
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This Chess AI comes from here
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https://github.com/glinscott/Garbochess-JS
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Copyright (c) 2011 Gary Linscott
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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1. Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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3. The name of the author may not be used to endorse or promote products
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derived from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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// Perf TODO:
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// Merge material updating with psq values
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// Put move scoring inline in generator
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// Remove need for fliptable in psq tables. Access them by color
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// Optimize pawn move generation
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// Non-perf todo:
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// Checks in first q?
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// Pawn eval.
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// Better king evaluation
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// Better move sorting in PV nodes (especially root)
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// ECMAScript 5 strict mode
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/* jshint globalstrict: true*/
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/* jslint newcap: true */
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/* global postMessage, self */
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"use strict";
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var g_debug = false;
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var g_timeout = 40;
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var g_maxply = 99;
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var worker = false;
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try {
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// not sure this will work on any browser
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// and since it's just for debug,
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// a try catch should be good enough
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if ( self.constructor.name === "DedicatedWorkerContext") {
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worker = true;
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}
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} catch(e) {}
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debug ("worker = "+worker);
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function GetFen() {
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var result = "";
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for (var row = 0; row < 8; row++) {
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if (row !== 0) {
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result += '/';
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}
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var empty = 0;
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for (var col = 0; col < 8; col++) {
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var piece = g_board[((row + 2) << 4) + col + 4];
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if (piece === 0) {
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empty++;
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} else {
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if (empty !== 0) {
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result += empty;
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}
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empty = 0;
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var pieceChar = [" ", "p", "n", "b", "r", "q", "k", " "][(piece & 0x7)];
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result += ((piece & colorWhite) !== 0) ? pieceChar.toUpperCase() : pieceChar;
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}
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}
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if (empty !== 0) {
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result += empty;
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}
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}
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result += g_toMove == colorWhite ? " w" : " b";
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result += " ";
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if (g_castleRights === 0) {
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result += "-";
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}
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else {
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if ((g_castleRights & 1) !== 0)
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result += "K";
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if ((g_castleRights & 2) !== 0)
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result += "Q";
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if ((g_castleRights & 4) !== 0)
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result += "k";
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if ((g_castleRights & 8) !== 0)
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result += "q";
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}
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result += " ";
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if (g_enPassentSquare == -1) {
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result += '-';
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}
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else {
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result += FormatSquare(g_enPassentSquare);
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}
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return result;
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}
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function GetMoveSAN(move, validMoves) {
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var from = move & 0xFF;
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var to = (move >> 8) & 0xFF;
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if (move & moveflagCastleKing) return "O-O";
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if (move & moveflagCastleQueen) return "O-O-O";
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var pieceType = g_board[from] & 0x7;
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var result = ["", "", "N", "B", "R", "Q", "K", ""][pieceType];
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var dupe = false, rowDiff = true, colDiff = true;
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if (validMoves === undefined) {
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validMoves = GenerateValidMoves();
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}
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for (var i = 0; i < validMoves.length; i++) {
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var moveFrom = validMoves[i] & 0xFF;
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var moveTo = (validMoves[i] >> 8) & 0xFF;
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if (moveFrom != from &&
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moveTo == to &&
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(g_board[moveFrom] & 0x7) == pieceType) {
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dupe = true;
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if ((moveFrom & 0xF0) == (from & 0xF0)) {
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rowDiff = false;
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}
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if ((moveFrom & 0x0F) == (from & 0x0F)) {
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colDiff = false;
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}
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}
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}
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if (dupe) {
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if (colDiff) {
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result += FormatSquare(from).charAt(0);
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} else if (rowDiff) {
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result += FormatSquare(from).charAt(1);
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} else {
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result += FormatSquare(from);
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}
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} else if (pieceType === piecePawn && (g_board[to] !== 0 || (move & moveflagEPC))) {
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result += FormatSquare(from).charAt(0);
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}
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if (g_board[to] !== 0 || (move & moveflagEPC)) {
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result += "x";
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}
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result += FormatSquare(to);
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if (move & moveflagPromotion) {
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if (move & moveflagPromoteBishop) result += "=B";
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else if (move & moveflagPromoteKnight) result += "=N";
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else if (move & moveflagPromoteQueen) result += "=Q";
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else result += "=R";
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}
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MakeMove(move);
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if (g_inCheck) {
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result += GenerateValidMoves().length === 0 ? "#" : "+";
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}
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UnmakeMove(move);
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return result;
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}
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function FormatSquare(square) {
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var letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'];
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return letters[(square & 0xF) - 4] + ((9 - (square >> 4)) + 1);
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}
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function FormatMove(move) {
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var result = FormatSquare(move & 0xFF) + FormatSquare((move >> 8) & 0xFF);
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if (move & moveflagPromotion) {
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if (move & moveflagPromoteBishop) result += "b";
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else if (move & moveflagPromoteKnight) result += "n";
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else if (move & moveflagPromoteQueen) result += "q";
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else result += "r";
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}
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return result;
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}
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function GetMoveFromString(moveString) {
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var moves = GenerateValidMoves();
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for (var i = 0; i < moves.length; i++) {
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if (FormatMove(moves[i]) == moveString) {
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return moves[i];
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}
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}
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alert("busted! ->" + moveString + " fen:" + GetFen());
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}
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function PVFromHash(move, ply) {
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if (ply === 0)
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return "";
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if (move === 0) {
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if (g_inCheck) return "checkmate";
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return "stalemate";
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}
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var pvString = " " + GetMoveSAN(move);
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MakeMove(move);
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var hashNode = g_hashTable[g_hashKeyLow & g_hashMask];
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if (hashNode !== undefined && hashNode.lock === g_hashKeyHigh && hashNode.bestMove !== undefined) {
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pvString += PVFromHash(hashNode.bestMove, ply - 1);
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}
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UnmakeMove(move);
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return pvString;
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}
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//
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// Searching code
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//
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var g_startTime;
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var g_nodeCount;
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var g_qNodeCount;
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var g_searchValid;
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var g_globalPly = 0;
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function Search(finishMoveCallback, maxPly, finishPlyCallback) {
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debug("start search with maxPly:"+maxPly+" and timeout "+g_timeout);
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if (GenerateValidMoves().length === 0) {
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debug( g_inCheck ? 'Checkmate' : 'Stalemate' );
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return false;
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}
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var lastEval;
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var alpha = minEval;
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var beta = maxEval;
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g_globalPly++;
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g_nodeCount = 0;
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g_qNodeCount = 0;
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g_searchValid = true;
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var bestMove = 0;
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var value;
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g_startTime = (new Date()).getTime();
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var i;
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for (i = 1; i <= maxPly && g_searchValid; i++) {
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var tmp = AlphaBeta(i, 0, alpha, beta);
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if (!g_searchValid) break;
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value = tmp;
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if (value > alpha && value < beta) {
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alpha = value - 500;
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beta = value + 500;
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if (alpha < minEval) alpha = minEval;
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if (beta > maxEval) beta = maxEval;
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} else if (alpha != minEval) {
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alpha = minEval;
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beta = maxEval;
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i--;
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}
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if (g_hashTable[g_hashKeyLow & g_hashMask] !== undefined) {
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bestMove = g_hashTable[g_hashKeyLow & g_hashMask].bestMove;
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}
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if (finishPlyCallback !== undefined) {
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finishPlyCallback(bestMove, value, (new Date()).getTime() - g_startTime, i);
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}
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}
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if (finishMoveCallback !== undefined) {
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finishMoveCallback(bestMove, value, (new Date()).getTime() - g_startTime, i - 1);
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}
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}
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var minEval = -2000000;
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var maxEval = +2000000;
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var minMateBuffer = minEval + 2000;
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var maxMateBuffer = maxEval - 2000;
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var materialTable = [0, 800, 3350, 3450, 5000, 9750, 600000];
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var pawnAdj =
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[
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0, 0, 0, 0, 0, 0, 0, 0,
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-25, 105, 135, 270, 270, 135, 105, -25,
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-80, 0, 30, 176, 176, 30, 0, -80,
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-85, -5, 25, 175, 175, 25, -5, -85,
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-90, -10, 20, 125, 125, 20, -10, -90,
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-95, -15, 15, 75, 75, 15, -15, -95,
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-100, -20, 10, 70, 70, 10, -20, -100,
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0, 0, 0, 0, 0, 0, 0, 0
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];
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var knightAdj =
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[
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-200, -100, -50, -50, -50, -50, -100, -200,
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-100, 0, 0, 0, 0, 0, 0, -100,
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-50, 0, 60, 60, 60, 60, 0, -50,
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-50, 0, 30, 60, 60, 30, 0, -50,
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-50, 0, 30, 60, 60, 30, 0, -50,
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-50, 0, 30, 30, 30, 30, 0, -50,
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-100, 0, 0, 0, 0, 0, 0, -100,
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-200, -50, -25, -25, -25, -25, -50, -200
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];
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var bishopAdj =
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[
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-50,-50,-25,-10,-10,-25,-50,-50,
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-50,-25,-10, 0, 0,-10,-25,-50,
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-25,-10, 0, 25, 25, 0,-10,-25,
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-10, 0, 25, 40, 40, 25, 0,-10,
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-10, 0, 25, 40, 40, 25, 0,-10,
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-25,-10, 0, 25, 25, 0,-10,-25,
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-50,-25,-10, 0, 0,-10,-25,-50,
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-50,-50,-25,-10,-10,-25,-50,-50
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];
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var rookAdj =
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[
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-60, -30, -10, 20, 20, -10, -30, -60,
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40, 70, 90,120,120, 90, 70, 40,
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-60, -30, -10, 20, 20, -10, -30, -60,
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-60, -30, -10, 20, 20, -10, -30, -60,
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-60, -30, -10, 20, 20, -10, -30, -60,
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-60, -30, -10, 20, 20, -10, -30, -60,
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-60, -30, -10, 20, 20, -10, -30, -60,
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-60, -30, -10, 20, 20, -10, -30, -60
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];
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var kingAdj =
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[
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50, 150, -25, -125, -125, -25, 150, 50,
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50, 150, -25, -125, -125, -25, 150, 50,
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50, 150, -25, -125, -125, -25, 150, 50,
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50, 150, -25, -125, -125, -25, 150, 50,
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50, 150, -25, -125, -125, -25, 150, 50,
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50, 150, -25, -125, -125, -25, 150, 50,
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50, 150, -25, -125, -125, -25, 150, 50,
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150, 250, 75, -25, -25, 75, 250, 150
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];
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var emptyAdj =
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[
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0
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];
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var pieceSquareAdj = new Array(8);
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// Returns the square flipped
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var flipTable = new Array(256);
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function PawnEval(color) {
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var pieceIdx = (color | 1) << 4;
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var from = g_pieceList[pieceIdx++];
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while (from !== 0) {
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from = g_pieceList[pieceIdx++];
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}
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}
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function Mobility(color) {
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var result = 0;
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var from, to, mob, pieceIdx;
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var enemy = color == 8 ? 0x10 : 0x8;
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var mobUnit = color == 8 ? g_mobUnit[0] : g_mobUnit[1];
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// Knight mobility
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mob = -3;
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pieceIdx = (color | 2) << 4;
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from = g_pieceList[pieceIdx++];
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while (from !== 0) {
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mob += mobUnit[g_board[from + 31]];
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mob += mobUnit[g_board[from + 33]];
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mob += mobUnit[g_board[from + 14]];
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mob += mobUnit[g_board[from - 14]];
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mob += mobUnit[g_board[from - 31]];
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mob += mobUnit[g_board[from - 33]];
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mob += mobUnit[g_board[from + 18]];
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mob += mobUnit[g_board[from - 18]];
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from = g_pieceList[pieceIdx++];
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}
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result += 65 * mob;
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// Bishop mobility
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mob = -4;
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pieceIdx = (color | 3) << 4;
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from = g_pieceList[pieceIdx++];
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while (from !== 0) {
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to = from - 15;
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while (g_board[to] === 0) { to -= 15; mob++; }
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if (g_board[to] & enemy) {
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mob++;
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if (!(g_board[to] & piecePawn)) {
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to -= 15;
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while (g_board[to] === 0) to -= 15;
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mob += mobUnit[g_board[to]] << 2;
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}
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}
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to = from - 17;
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while (g_board[to] === 0) { to -= 17; mob++; }
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if (g_board[to] & enemy) {
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mob++;
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if (!(g_board[to] & piecePawn)) {
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to -= 17;
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while (g_board[to] === 0) to -= 17;
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mob += mobUnit[g_board[to]] << 2;
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}
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}
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to = from + 15;
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while (g_board[to] === 0) { to += 15; mob++; }
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if (g_board[to] & enemy) {
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mob++;
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if (!(g_board[to] & piecePawn)) {
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to += 15;
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while (g_board[to] === 0) to += 15;
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mob += mobUnit[g_board[to]] << 2;
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}
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}
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to = from + 17;
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while (g_board[to] === 0) { to += 17; mob++; }
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if (g_board[to] & enemy) {
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mob++;
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if (!(g_board[to] & piecePawn)) {
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to += 17;
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while (g_board[to] === 0) to += 17;
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mob += mobUnit[g_board[to]] << 2;
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}
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}
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from = g_pieceList[pieceIdx++];
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}
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result += 44 * mob;
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// Rook mobility
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mob = -4;
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pieceIdx = (color | 4) << 4;
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from = g_pieceList[pieceIdx++];
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while (from !== 0) {
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to = from - 1;
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while (g_board[to] === 0) { to--; mob++;}
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if (g_board[to] & enemy) mob++;
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to = from + 1;
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while (g_board[to] === 0) { to++; mob++; }
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if (g_board[to] & enemy) mob++;
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to = from + 16;
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while (g_board[to] === 0) { to += 16; mob++; }
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if (g_board[to] & enemy) mob++;
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to = from - 16;
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while (g_board[to] === 0) { to -= 16; mob++; }
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if (g_board[to] & enemy) mob++;
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from = g_pieceList[pieceIdx++];
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}
|
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result += 25 * mob;
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// Queen mobility
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mob = -2;
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pieceIdx = (color | 5) << 4;
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from = g_pieceList[pieceIdx++];
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while (from !== 0) {
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to = from - 15;
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while (g_board[to] === 0) { to -= 15; mob++; }
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if (g_board[to] & enemy) mob++;
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to = from - 17;
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while (g_board[to] === 0) { to -= 17; mob++; }
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if (g_board[to] & enemy) mob++;
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to = from + 15;
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while (g_board[to] === 0) { to += 15; mob++; }
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if (g_board[to] & enemy) mob++;
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to = from + 17;
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while (g_board[to] === 0) { to += 17; mob++; }
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if (g_board[to] & enemy) mob++;
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to = from - 1;
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|
while (g_board[to] === 0) { to--; mob++; }
|
|
if (g_board[to] & enemy) mob++;
|
|
to = from + 1;
|
|
while (g_board[to] === 0) { to++; mob++; }
|
|
if (g_board[to] & enemy) mob++;
|
|
to = from + 16;
|
|
while (g_board[to] === 0) { to += 16; mob++; }
|
|
if (g_board[to] & enemy) mob++;
|
|
to = from - 16;
|
|
while (g_board[to] === 0) { to -= 16; mob++; }
|
|
if (g_board[to] & enemy) mob++;
|
|
from = g_pieceList[pieceIdx++];
|
|
}
|
|
result += 22 * mob;
|
|
|
|
return result;
|
|
}
|
|
|
|
function Evaluate() {
|
|
var curEval = g_baseEval;
|
|
|
|
var evalAdjust = 0;
|
|
// Black queen gone, then cancel white's penalty for king movement
|
|
if (g_pieceList[pieceQueen << 4] === 0)
|
|
evalAdjust -= pieceSquareAdj[pieceKing][g_pieceList[(colorWhite | pieceKing) << 4]];
|
|
// White queen gone, then cancel black's penalty for king movement
|
|
if (g_pieceList[(colorWhite | pieceQueen) << 4] === 0)
|
|
evalAdjust += pieceSquareAdj[pieceKing][flipTable[g_pieceList[pieceKing << 4]]];
|
|
|
|
// Black bishop pair
|
|
if (g_pieceCount[pieceBishop] >= 2)
|
|
evalAdjust -= 500;
|
|
// White bishop pair
|
|
if (g_pieceCount[pieceBishop | colorWhite] >= 2)
|
|
evalAdjust += 500;
|
|
|
|
var mobility = Mobility(8) - Mobility(0);
|
|
|
|
if (g_toMove === 0) {
|
|
// Black
|
|
curEval -= mobility;
|
|
curEval -= evalAdjust;
|
|
}
|
|
else {
|
|
curEval += mobility;
|
|
curEval += evalAdjust;
|
|
}
|
|
|
|
return curEval;
|
|
}
|
|
|
|
function ScoreMove(move){
|
|
var moveTo = (move >> 8) & 0xFF;
|
|
var captured = g_board[moveTo] & 0x7;
|
|
var piece = g_board[move & 0xFF];
|
|
var score;
|
|
if (captured !== 0) {
|
|
var pieceType = piece & 0x7;
|
|
score = (captured << 5) - pieceType;
|
|
} else {
|
|
score = historyTable[piece & 0xF][moveTo];
|
|
}
|
|
return score;
|
|
}
|
|
|
|
function QSearch(alpha, beta, ply) {
|
|
g_qNodeCount++;
|
|
|
|
var realEval = g_inCheck ? (minEval + 1) : Evaluate();
|
|
|
|
if (realEval >= beta)
|
|
return realEval;
|
|
|
|
if (realEval > alpha)
|
|
alpha = realEval;
|
|
|
|
var moves = [];
|
|
var moveScores = [];
|
|
var wasInCheck = g_inCheck;
|
|
var i;
|
|
|
|
if (wasInCheck) {
|
|
// TODO: Fast check escape generator and fast checking moves generator
|
|
GenerateCaptureMoves(moves, null);
|
|
GenerateAllMoves(moves);
|
|
|
|
for (i = 0; i < moves.length; i++) {
|
|
moveScores[i] = ScoreMove(moves[i]);
|
|
}
|
|
} else {
|
|
GenerateCaptureMoves(moves, null);
|
|
|
|
for (i = 0; i < moves.length; i++) {
|
|
var captured = g_board[(moves[i] >> 8) & 0xFF] & 0x7;
|
|
var pieceType = g_board[moves[i] & 0xFF] & 0x7;
|
|
|
|
moveScores[i] = (captured << 5) - pieceType;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < moves.length; i++) {
|
|
var bestMove = i;
|
|
for (var j = moves.length - 1; j > i; j--) {
|
|
if (moveScores[j] > moveScores[bestMove]) {
|
|
bestMove = j;
|
|
}
|
|
}
|
|
|
|
var tmpMove = moves[i];
|
|
moves[i] = moves[bestMove];
|
|
moves[bestMove] = tmpMove;
|
|
|
|
var tmpScore = moveScores[i];
|
|
moveScores[i] = moveScores[bestMove];
|
|
moveScores[bestMove] = tmpScore;
|
|
|
|
if (!wasInCheck && !See(moves[i])) {
|
|
continue;
|
|
}
|
|
|
|
if (!MakeMove(moves[i])) {
|
|
continue;
|
|
}
|
|
|
|
var value = -QSearch(-beta, -alpha, ply - 1);
|
|
|
|
UnmakeMove(moves[i]);
|
|
|
|
if (value > realEval) {
|
|
if (value >= beta)
|
|
return value;
|
|
|
|
if (value > alpha)
|
|
alpha = value;
|
|
|
|
realEval = value;
|
|
}
|
|
}
|
|
|
|
/* Disable checks... Too slow currently
|
|
|
|
if (ply == 0 && !wasInCheck) {
|
|
moves = [];
|
|
GenerateAllMoves(moves);
|
|
|
|
for (var i = 0; i < moves.length; i++) {
|
|
moveScores[i] = ScoreMove(moves[i]);
|
|
}
|
|
|
|
for (var i = 0; i < moves.length; i++) {
|
|
var bestMove = i;
|
|
for (var j = moves.length - 1; j > i; j--) {
|
|
if (moveScores[j] > moveScores[bestMove]) {
|
|
bestMove = j;
|
|
}
|
|
}
|
|
{
|
|
var tmpMove = moves[i];
|
|
moves[i] = moves[bestMove];
|
|
moves[bestMove] = tmpMove;
|
|
|
|
var tmpScore = moveScores[i];
|
|
moveScores[i] = moveScores[bestMove];
|
|
moveScores[bestMove] = tmpScore;
|
|
}
|
|
|
|
if (!MakeMove(moves[i])) {
|
|
continue;
|
|
}
|
|
var checking = g_inCheck;
|
|
UnmakeMove(moves[i]);
|
|
|
|
if (!checking) {
|
|
continue;
|
|
}
|
|
|
|
if (!See(moves[i])) {
|
|
continue;
|
|
}
|
|
|
|
MakeMove(moves[i]);
|
|
|
|
var value = -QSearch(-beta, -alpha, ply - 1);
|
|
|
|
UnmakeMove(moves[i]);
|
|
|
|
if (value > realEval) {
|
|
if (value >= beta)
|
|
return value;
|
|
|
|
if (value > alpha)
|
|
alpha = value;
|
|
|
|
realEval = value;
|
|
}
|
|
}
|
|
}
|
|
*/
|
|
|
|
return realEval;
|
|
}
|
|
|
|
function StoreHash(value, flags, ply, move, depth) {
|
|
if (value >= maxMateBuffer)
|
|
value += depth;
|
|
else if (value <= minMateBuffer)
|
|
value -= depth;
|
|
g_hashTable[g_hashKeyLow & g_hashMask] = new HashEntry(g_hashKeyHigh, value, flags, ply, move);
|
|
}
|
|
|
|
function IsHashMoveValid(hashMove) {
|
|
var from = hashMove & 0xFF;
|
|
var to = (hashMove >> 8) & 0xFF;
|
|
var ourPiece = g_board[from];
|
|
var pieceType = ourPiece & 0x7;
|
|
if (pieceType < piecePawn || pieceType > pieceKing) return false;
|
|
// Can't move a piece we don't control
|
|
if (g_toMove != (ourPiece & 0x8))
|
|
return false;
|
|
// Can't move to a square that has something of the same color
|
|
if (g_board[to] !== 0 && (g_toMove == (g_board[to] & 0x8)))
|
|
return false;
|
|
if (pieceType == piecePawn) {
|
|
if (hashMove & moveflagEPC) {
|
|
return false;
|
|
}
|
|
|
|
// Valid moves are push, capture, double push, promotions
|
|
var dir = to - from;
|
|
if ((g_toMove == colorWhite) != (dir < 0)) {
|
|
// Pawns have to move in the right direction
|
|
return false;
|
|
}
|
|
|
|
var row = to & 0xF0;
|
|
if (((row == 0x90 && !g_toMove) ||
|
|
(row == 0x20 && g_toMove)) !== (hashMove & moveflagPromotion)) {
|
|
// Handle promotions
|
|
return false;
|
|
}
|
|
|
|
if (dir === -16 || dir === 16) {
|
|
// White/Black push
|
|
return g_board[to] === 0;
|
|
} else if (dir === -15 || dir === -17 || dir === 15 || dir === 17) {
|
|
// White/Black capture
|
|
return g_board[to] !== 0;
|
|
} else if (dir === -32) {
|
|
// Double white push
|
|
if (row !== 0x60) return false;
|
|
if (g_board[to] !== 0) return false;
|
|
if (g_board[from - 16] !== 0) return false;
|
|
} else if (dir == 32) {
|
|
// Double black push
|
|
if (row !== 0x50) return false;
|
|
if (g_board[to] !== 0) return false;
|
|
if (g_board[from + 16] !== 0) return false;
|
|
} else {
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
} else {
|
|
// This validates that this piece type can actually make the attack
|
|
if (hashMove >> 16) return false;
|
|
return IsSquareAttackableFrom(to, from);
|
|
}
|
|
}
|
|
|
|
function IsRepDraw() {
|
|
var stop = g_moveCount - 1 - g_move50;
|
|
stop = stop < 0 ? 0 : stop;
|
|
for (var i = g_moveCount - 5; i >= stop; i -= 2) {
|
|
if (g_repMoveStack[i] == g_hashKeyLow)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
function MovePicker(hashMove, depth, killer1, killer2) {
|
|
this.hashMove = hashMove;
|
|
this.depth = depth;
|
|
this.killer1 = killer1;
|
|
this.killer2 = killer2;
|
|
|
|
this.moves = [];
|
|
this.losingCaptures = null;
|
|
this.moveCount = 0;
|
|
this.atMove = -1;
|
|
this.moveScores = null;
|
|
this.stage = 0;
|
|
|
|
this.nextMove = function () {
|
|
var i;
|
|
if (++this.atMove == this.moveCount) {
|
|
this.stage++;
|
|
if (this.stage == 1) {
|
|
if (this.hashMove !== undefined && IsHashMoveValid(hashMove)) {
|
|
this.moves[0] = hashMove;
|
|
this.moveCount = 1;
|
|
}
|
|
if (this.moveCount != 1) {
|
|
this.hashMove = undefined;
|
|
this.stage++;
|
|
}
|
|
}
|
|
|
|
if (this.stage == 2) {
|
|
GenerateCaptureMoves(this.moves, null);
|
|
this.moveCount = this.moves.length;
|
|
this.moveScores = new Array(this.moveCount);
|
|
// Move ordering
|
|
for (i = this.atMove; i < this.moveCount; i++) {
|
|
var captured = g_board[(this.moves[i] >> 8) & 0xFF] & 0x7;
|
|
var pieceType = g_board[this.moves[i] & 0xFF] & 0x7;
|
|
this.moveScores[i] = (captured << 5) - pieceType;
|
|
}
|
|
// No moves, onto next stage
|
|
if (this.atMove == this.moveCount) this.stage++;
|
|
}
|
|
|
|
if (this.stage == 3) {
|
|
if (IsHashMoveValid(this.killer1) &&
|
|
this.killer1 != this.hashMove) {
|
|
this.moves[this.moves.length] = this.killer1;
|
|
this.moveCount = this.moves.length;
|
|
} else {
|
|
this.killer1 = 0;
|
|
this.stage++;
|
|
}
|
|
}
|
|
|
|
if (this.stage == 4) {
|
|
if (IsHashMoveValid(this.killer2) &&
|
|
this.killer2 != this.hashMove) {
|
|
this.moves[this.moves.length] = this.killer2;
|
|
this.moveCount = this.moves.length;
|
|
} else {
|
|
this.killer2 = 0;
|
|
this.stage++;
|
|
}
|
|
}
|
|
|
|
if (this.stage == 5) {
|
|
GenerateAllMoves(this.moves);
|
|
this.moveCount = this.moves.length;
|
|
// Move ordering
|
|
for (i = this.atMove; i < this.moveCount; i++) this.moveScores[i] = ScoreMove(this.moves[i]);
|
|
// No moves, onto next stage
|
|
if (this.atMove === this.moveCount) this.stage++;
|
|
}
|
|
|
|
if (this.stage === 6) {
|
|
// Losing captures
|
|
if (this.losingCaptures !== null) {
|
|
for (i = 0; i < this.losingCaptures.length; i++) {
|
|
this.moves[this.moves.length] = this.losingCaptures[i];
|
|
}
|
|
for (i = this.atMove; i < this.moveCount; i++) this.moveScores[i] = ScoreMove(this.moves[i]);
|
|
this.moveCount = this.moves.length;
|
|
}
|
|
// No moves, onto next stage
|
|
if (this.atMove === this.moveCount) this.stage++;
|
|
}
|
|
|
|
if (this.stage === 7)
|
|
return 0;
|
|
}
|
|
|
|
var bestMove = this.atMove;
|
|
for (var j = this.atMove + 1; j < this.moveCount; j++) {
|
|
if (this.moveScores[j] > this.moveScores[bestMove]) {
|
|
bestMove = j;
|
|
}
|
|
}
|
|
|
|
if (bestMove != this.atMove) {
|
|
var tmpMove = this.moves[this.atMove];
|
|
this.moves[this.atMove] = this.moves[bestMove];
|
|
this.moves[bestMove] = tmpMove;
|
|
|
|
var tmpScore = this.moveScores[this.atMove];
|
|
this.moveScores[this.atMove] = this.moveScores[bestMove];
|
|
this.moveScores[bestMove] = tmpScore;
|
|
}
|
|
|
|
var candidateMove = this.moves[this.atMove];
|
|
if ((this.stage > 1 && candidateMove == this.hashMove) ||
|
|
(this.stage > 3 && candidateMove == this.killer1) ||
|
|
(this.stage > 4 && candidateMove == this.killer2)) {
|
|
return this.nextMove();
|
|
}
|
|
|
|
if (this.stage === 2 && !See(candidateMove)) {
|
|
if (this.losingCaptures === null) {
|
|
this.losingCaptures = [];
|
|
}
|
|
this.losingCaptures[this.losingCaptures.length] = candidateMove;
|
|
return this.nextMove();
|
|
}
|
|
|
|
return this.moves[this.atMove];
|
|
};
|
|
}
|
|
|
|
function AllCutNode(ply, depth, beta, allowNull) {
|
|
if (ply <= 0) {
|
|
return QSearch(beta - 1, beta, 0);
|
|
}
|
|
|
|
if ((g_nodeCount & 127) == 127) {
|
|
if ((new Date()).getTime() - g_startTime > g_timeout) {
|
|
// Time cutoff
|
|
g_searchValid = false;
|
|
return beta - 1;
|
|
}
|
|
}
|
|
|
|
g_nodeCount++;
|
|
|
|
if (IsRepDraw())
|
|
return 0;
|
|
|
|
// Mate distance pruning
|
|
if (minEval + depth >= beta)
|
|
return beta;
|
|
|
|
if (maxEval - (depth + 1) < beta)
|
|
return beta - 1;
|
|
|
|
var hashMove = null;
|
|
var hashNode = g_hashTable[g_hashKeyLow & g_hashMask];
|
|
if (hashNode !== undefined && hashNode.lock === g_hashKeyHigh) {
|
|
hashMove = hashNode.bestMove;
|
|
if (hashNode.hashDepth >= ply) {
|
|
var hashValue = hashNode.value;
|
|
|
|
// Fixup mate scores
|
|
if (hashValue >= maxMateBuffer)
|
|
hashValue -= depth;
|
|
else if (hashValue <= minMateBuffer)
|
|
hashValue += depth;
|
|
|
|
if (hashNode.flags === hashflagExact)
|
|
return hashValue;
|
|
if (hashNode.flags === hashflagAlpha && hashValue < beta)
|
|
return hashValue;
|
|
if (hashNode.flags === hashflagBeta && hashValue >= beta)
|
|
return hashValue;
|
|
}
|
|
}
|
|
|
|
// TODO - positional gain?
|
|
var value;
|
|
if (!g_inCheck &&
|
|
allowNull &&
|
|
beta > minMateBuffer &&
|
|
beta < maxMateBuffer) {
|
|
// Try some razoring
|
|
if (hashMove === undefined &&
|
|
ply < 4) {
|
|
var razorMargin = 2500 + 200 * ply;
|
|
if (g_baseEval < beta - razorMargin) {
|
|
var razorBeta = beta - razorMargin;
|
|
var v = QSearch(razorBeta - 1, razorBeta, 0);
|
|
if (v < razorBeta)
|
|
return v;
|
|
}
|
|
}
|
|
|
|
// TODO - static null move
|
|
|
|
// Null move
|
|
if (ply > 1 &&
|
|
g_baseEval >= beta - (ply >= 4 ? 2500 : 0) &&
|
|
// Disable null move if potential zugzwang (no big pieces)
|
|
(g_pieceCount[pieceBishop | g_toMove] !== 0 ||
|
|
g_pieceCount[pieceKnight | g_toMove] !== 0 ||
|
|
g_pieceCount[pieceRook | g_toMove] !== 0 ||
|
|
g_pieceCount[pieceQueen | g_toMove] !== 0)) {
|
|
var r = 3 + (ply >= 5 ? 1 : ply / 4);
|
|
if (g_baseEval - beta > 1500) r++;
|
|
|
|
g_toMove = 8 - g_toMove;
|
|
g_baseEval = -g_baseEval;
|
|
g_hashKeyLow ^= g_zobristBlackLow;
|
|
g_hashKeyHigh ^= g_zobristBlackHigh;
|
|
|
|
value = -AllCutNode(ply - r, depth + 1, -(beta - 1), false);
|
|
|
|
g_hashKeyLow ^= g_zobristBlackLow;
|
|
g_hashKeyHigh ^= g_zobristBlackHigh;
|
|
g_toMove = 8 - g_toMove;
|
|
g_baseEval = -g_baseEval;
|
|
|
|
if (value >= beta)
|
|
return beta;
|
|
}
|
|
}
|
|
|
|
var moveMade = false;
|
|
var realEval = minEval - 1;
|
|
var inCheck = g_inCheck;
|
|
|
|
var movePicker = new MovePicker(hashMove, depth, g_killers[depth][0], g_killers[depth][1]);
|
|
|
|
for (;;) {
|
|
var currentMove = movePicker.nextMove();
|
|
if (currentMove === 0) {
|
|
break;
|
|
}
|
|
|
|
var plyToSearch = ply - 1;
|
|
|
|
if (!MakeMove(currentMove)) {
|
|
continue;
|
|
}
|
|
|
|
value = null;
|
|
var doFullSearch = true;
|
|
|
|
if (g_inCheck) {
|
|
// Check extensions
|
|
plyToSearch++;
|
|
} else {
|
|
var reduced = plyToSearch - (movePicker.atMove > 14 ? 2 : 1);
|
|
|
|
// Futility pruning
|
|
/* if (movePicker.stage == 5 && !inCheck) {
|
|
if (movePicker.atMove >= (15 + (1 << (5 * ply) >> 2)) &&
|
|
realEval > minMateBuffer) {
|
|
UnmakeMove(currentMove);
|
|
continue;
|
|
}
|
|
|
|
if (ply < 7) {
|
|
var reducedPly = reduced <= 0 ? 0 : reduced;
|
|
var futilityValue = -g_baseEval + (900 * (reducedPly + 2)) - (movePicker.atMove * 10);
|
|
if (futilityValue < beta) {
|
|
if (futilityValue > realEval) {
|
|
realEval = futilityValue;
|
|
}
|
|
UnmakeMove(currentMove);
|
|
continue;
|
|
}
|
|
}
|
|
}*/
|
|
|
|
// Late move reductions
|
|
if (movePicker.stage == 5 && movePicker.atMove > 5 && ply >= 3) {
|
|
value = -AllCutNode(reduced, depth + 1, -(beta - 1), true);
|
|
doFullSearch = (value >= beta);
|
|
}
|
|
}
|
|
|
|
if (doFullSearch) {
|
|
value = -AllCutNode(plyToSearch, depth + 1, -(beta - 1), true);
|
|
}
|
|
|
|
moveMade = true;
|
|
|
|
UnmakeMove(currentMove);
|
|
|
|
if (!g_searchValid) {
|
|
return beta - 1;
|
|
}
|
|
|
|
if (value > realEval) {
|
|
if (value >= beta) {
|
|
var histTo = (currentMove >> 8) & 0xFF;
|
|
if (g_board[histTo] === 0) {
|
|
var histPiece = g_board[currentMove & 0xFF] & 0xF;
|
|
historyTable[histPiece][histTo] += ply * ply;
|
|
if (historyTable[histPiece][histTo] > 32767) {
|
|
historyTable[histPiece][histTo] >>= 1;
|
|
}
|
|
|
|
if (g_killers[depth][0] != currentMove) {
|
|
g_killers[depth][1] = g_killers[depth][0];
|
|
g_killers[depth][0] = currentMove;
|
|
}
|
|
}
|
|
|
|
StoreHash(value, hashflagBeta, ply, currentMove, depth);
|
|
return value;
|
|
}
|
|
|
|
realEval = value;
|
|
hashMove = currentMove;
|
|
}
|
|
}
|
|
|
|
if (!moveMade) {
|
|
// If we have no valid moves it's either stalemate or checkmate
|
|
if (g_inCheck)
|
|
// Checkmate.
|
|
return minEval + depth;
|
|
else
|
|
// Stalemate
|
|
return 0;
|
|
}
|
|
|
|
StoreHash(realEval, hashflagAlpha, ply, hashMove, depth);
|
|
|
|
return realEval;
|
|
}
|
|
|
|
function AlphaBeta(ply, depth, alpha, beta) {
|
|
if (ply <= 0) {
|
|
return QSearch(alpha, beta, 0);
|
|
}
|
|
|
|
g_nodeCount++;
|
|
|
|
if (depth > 0 && IsRepDraw())
|
|
return 0;
|
|
|
|
// Mate distance pruning
|
|
var oldAlpha = alpha;
|
|
alpha = alpha < minEval + depth ? alpha : minEval + depth;
|
|
beta = beta > maxEval - (depth + 1) ? beta : maxEval - (depth + 1);
|
|
if (alpha >= beta)
|
|
return alpha;
|
|
|
|
var hashMove = null;
|
|
var hashFlag = hashflagAlpha;
|
|
var hashNode = g_hashTable[g_hashKeyLow & g_hashMask];
|
|
if (hashNode !== undefined && hashNode.lock === g_hashKeyHigh) {
|
|
hashMove = hashNode.bestMove;
|
|
}
|
|
|
|
var inCheck = g_inCheck;
|
|
|
|
var moveMade = false;
|
|
var realEval = minEval;
|
|
|
|
var movePicker = new MovePicker(hashMove, depth, g_killers[depth][0], g_killers[depth][1]);
|
|
|
|
for (;;) {
|
|
var currentMove = movePicker.nextMove();
|
|
if (currentMove === 0) {
|
|
break;
|
|
}
|
|
|
|
var plyToSearch = ply - 1;
|
|
|
|
if (!MakeMove(currentMove)) {
|
|
continue;
|
|
}
|
|
|
|
if (g_inCheck) {
|
|
// Check extensions
|
|
plyToSearch++;
|
|
}
|
|
|
|
var value;
|
|
if (moveMade) {
|
|
value = -AllCutNode(plyToSearch, depth + 1, -alpha, true);
|
|
if (value > alpha) {
|
|
value = -AlphaBeta(plyToSearch, depth + 1, -beta, -alpha);
|
|
}
|
|
} else {
|
|
value = -AlphaBeta(plyToSearch, depth + 1, -beta, -alpha);
|
|
}
|
|
|
|
moveMade = true;
|
|
|
|
UnmakeMove(currentMove);
|
|
|
|
if (!g_searchValid) {
|
|
return alpha;
|
|
}
|
|
|
|
if (value > realEval) {
|
|
if (value >= beta) {
|
|
var histTo = (currentMove >> 8) & 0xFF;
|
|
if (g_board[histTo] === 0) {
|
|
var histPiece = g_board[currentMove & 0xFF] & 0xF;
|
|
historyTable[histPiece][histTo] += ply * ply;
|
|
if (historyTable[histPiece][histTo] > 32767) {
|
|
historyTable[histPiece][histTo] >>= 1;
|
|
}
|
|
|
|
if (g_killers[depth][0] !== currentMove) {
|
|
g_killers[depth][1] = g_killers[depth][0];
|
|
g_killers[depth][0] = currentMove;
|
|
}
|
|
}
|
|
|
|
StoreHash(value, hashflagBeta, ply, currentMove, depth);
|
|
return value;
|
|
}
|
|
|
|
if (value > oldAlpha) {
|
|
hashFlag = hashflagExact;
|
|
alpha = value;
|
|
}
|
|
|
|
realEval = value;
|
|
hashMove = currentMove;
|
|
}
|
|
}
|
|
|
|
if (!moveMade) {
|
|
// If we have no valid moves it's either stalemate or checkmate
|
|
if (inCheck)
|
|
// Checkmate.
|
|
return minEval + depth;
|
|
else
|
|
// Stalemate
|
|
return 0;
|
|
}
|
|
|
|
StoreHash(realEval, hashFlag, ply, hashMove, depth);
|
|
|
|
return realEval;
|
|
}
|
|
|
|
//
|
|
// Board code
|
|
//
|
|
|
|
// This somewhat funky scheme means that a piece is indexed by it's lower 4 bits when accessing in arrays. The fifth bit (black bit)
|
|
// is used to allow quick edge testing on the board.
|
|
var colorBlack = 0x10;
|
|
var colorWhite = 0x08;
|
|
|
|
var pieceEmpty = 0x00;
|
|
var piecePawn = 0x01;
|
|
var pieceKnight = 0x02;
|
|
var pieceBishop = 0x03;
|
|
var pieceRook = 0x04;
|
|
var pieceQueen = 0x05;
|
|
var pieceKing = 0x06;
|
|
|
|
var g_vectorDelta = new Array(256);
|
|
|
|
var g_bishopDeltas = [-15, -17, 15, 17];
|
|
var g_knightDeltas = [31, 33, 14, -14, -31, -33, 18, -18];
|
|
var g_rookDeltas = [-1, +1, -16, +16];
|
|
var g_queenDeltas = [-1, +1, -15, +15, -17, +17, -16, +16];
|
|
|
|
var g_castleRightsMask = [
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 7,15,15,15, 3,15,15,11, 0, 0, 0, 0,
|
|
0, 0, 0, 0,15,15,15,15,15,15,15,15, 0, 0, 0, 0,
|
|
0, 0, 0, 0,15,15,15,15,15,15,15,15, 0, 0, 0, 0,
|
|
0, 0, 0, 0,15,15,15,15,15,15,15,15, 0, 0, 0, 0,
|
|
0, 0, 0, 0,15,15,15,15,15,15,15,15, 0, 0, 0, 0,
|
|
0, 0, 0, 0,15,15,15,15,15,15,15,15, 0, 0, 0, 0,
|
|
0, 0, 0, 0,15,15,15,15,15,15,15,15, 0, 0, 0, 0,
|
|
0, 0, 0, 0,13,15,15,15,12,15,15,14, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
|
|
];
|
|
|
|
var moveflagEPC = 0x2 << 16;
|
|
var moveflagCastleKing = 0x4 << 16;
|
|
var moveflagCastleQueen = 0x8 << 16;
|
|
var moveflagPromotion = 0x10 << 16;
|
|
var moveflagPromoteRook = 0x00 << 16;
|
|
var moveflagPromoteKnight = 0x20 << 16;
|
|
var moveflagPromoteQueen = 0x40 << 16;
|
|
var moveflagPromoteBishop = 0x80 << 16;
|
|
|
|
function MT() {
|
|
var N = 624;
|
|
var M = 397;
|
|
var MAG01 = [0x0, 0x9908b0df];
|
|
|
|
this.mt = new Array(N);
|
|
this.mti = N + 1;
|
|
|
|
this.setSeed = function()
|
|
{
|
|
var a = arguments;
|
|
var i,s,k;
|
|
switch (a.length) {
|
|
case 1:
|
|
if (a[0].constructor === Number) {
|
|
this.mt[0]= a[0];
|
|
for (i = 1; i < N; ++i) {
|
|
s = this.mt[i - 1] ^ (this.mt[i - 1] >>> 30);
|
|
this.mt[i] = (
|
|
(1812433253 * ((s & 0xffff0000) >>> 16))
|
|
<< 16
|
|
) +
|
|
1812433253 * (s & 0x0000ffff) +
|
|
i;
|
|
}
|
|
this.mti = N;
|
|
return;
|
|
}
|
|
|
|
this.setSeed(19650218);
|
|
|
|
var l = a[0].length;
|
|
var j = 0;
|
|
i = 1;
|
|
|
|
for (k = N > l ? N : l; k !== 0; --k) {
|
|
s = this.mt[i - 1] ^ (this.mt[i - 1] >>> 30);
|
|
this.mt[i] = (
|
|
this.mt[i] ^
|
|
(
|
|
((1664525 * ((s & 0xffff0000) >>> 16)) << 16) +
|
|
1664525 * (s & 0x0000ffff)
|
|
)
|
|
) + a[0][j] + j;
|
|
if (++i >= N) {
|
|
this.mt[0] = this.mt[N - 1];
|
|
i = 1;
|
|
}
|
|
if (++j >= l) {
|
|
j = 0;
|
|
}
|
|
}
|
|
|
|
for (k = N - 1; k !== 0; --k) {
|
|
s = this.mt[i - 1] ^ (this.mt[i - 1] >>> 30);
|
|
this.mt[i] = (
|
|
this.mt[i] ^
|
|
(
|
|
((1566083941 * ((s & 0xffff0000) >>> 16)) << 16) +
|
|
1566083941 * (s & 0x0000ffff)
|
|
)
|
|
) - i;
|
|
|
|
if (++i >= N) {
|
|
this.mt[0] = this.mt[N-1];
|
|
i = 1;
|
|
}
|
|
}
|
|
|
|
this.mt[0] = 0x80000000;
|
|
return;
|
|
default:
|
|
var seeds = [];
|
|
for (i = 0; i < a.length; ++i) {
|
|
seeds.push(a[i]);
|
|
}
|
|
this.setSeed(seeds);
|
|
return;
|
|
}
|
|
};
|
|
|
|
this.setSeed(0x1BADF00D);
|
|
|
|
this.next = function (bits)
|
|
{
|
|
var k;
|
|
if (this.mti >= N) {
|
|
var x = 0;
|
|
|
|
for (k = 0; k < N - M; ++k) {
|
|
x = (this.mt[k] & 0x80000000) | (this.mt[k + 1] & 0x7fffffff);
|
|
this.mt[k] = this.mt[k + M] ^ (x >>> 1) ^ MAG01[x & 0x1];
|
|
}
|
|
for (k = N - M; k < N - 1; ++k) {
|
|
x = (this.mt[k] & 0x80000000) | (this.mt[k + 1] & 0x7fffffff);
|
|
this.mt[k] = this.mt[k + (M - N)] ^ (x >>> 1) ^ MAG01[x & 0x1];
|
|
}
|
|
x = (this.mt[N - 1] & 0x80000000) | (this.mt[0] & 0x7fffffff);
|
|
this.mt[N - 1] = this.mt[M - 1] ^ (x >>> 1) ^ MAG01[x & 0x1];
|
|
|
|
this.mti = 0;
|
|
}
|
|
|
|
var y = this.mt[this.mti++];
|
|
y ^= y >>> 11;
|
|
y ^= (y << 7) & 0x9d2c5680;
|
|
y ^= (y << 15) & 0xefc60000;
|
|
y ^= y >>> 18;
|
|
return (y >>> (32 - bits)) & 0xFFFFFFFF;
|
|
};
|
|
}
|
|
|
|
// Position variables
|
|
var g_board = new Array(256); // Sentinel 0x80, pieces are in low 4 bits, 0x8 for color, 0x7 bits for piece type
|
|
var g_toMove; // side to move, 0 or 8, 0 = black, 8 = white
|
|
var g_castleRights; // bitmask representing castling rights, 1 = wk, 2 = wq, 4 = bk, 8 = bq
|
|
var g_enPassentSquare;
|
|
var g_baseEval;
|
|
var g_hashKeyLow, g_hashKeyHigh;
|
|
var g_inCheck;
|
|
|
|
// Utility variables
|
|
var g_moveCount = 0;
|
|
var g_moveUndoStack = [];
|
|
|
|
var g_move50 = 0;
|
|
var g_repMoveStack = [];
|
|
|
|
var g_hashSize = 1 << 22;
|
|
var g_hashMask = g_hashSize - 1;
|
|
var g_hashTable;
|
|
|
|
var g_killers;
|
|
var historyTable = new Array(32);
|
|
|
|
var g_zobristLow;
|
|
var g_zobristHigh;
|
|
var g_zobristBlackLow;
|
|
var g_zobristBlackHigh;
|
|
|
|
// Evaulation variables
|
|
var g_mobUnit;
|
|
|
|
var hashflagAlpha = 1;
|
|
var hashflagBeta = 2;
|
|
var hashflagExact = 3;
|
|
|
|
function HashEntry(lock, value, flags, hashDepth, bestMove, globalPly) {
|
|
this.lock = lock;
|
|
this.value = value;
|
|
this.flags = flags;
|
|
this.hashDepth = hashDepth;
|
|
this.bestMove = bestMove;
|
|
}
|
|
|
|
function MakeSquare(row, column) {
|
|
return ((row + 2) << 4) | (column + 4);
|
|
}
|
|
|
|
function MakeTable(table) {
|
|
var result = new Array(256);
|
|
for (var i = 0; i < 256; i++) {
|
|
result[i] = 0;
|
|
}
|
|
for (var row = 0; row < 8; row++) {
|
|
for (var col = 0; col < 8; col++) {
|
|
result[MakeSquare(row, col)] = table[row * 8 + col];
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
function ResetGame(fen) {
|
|
var i,j;
|
|
var row, col;
|
|
var square;
|
|
g_killers = new Array(128);
|
|
|
|
for (i = 0; i < 128; i++) {
|
|
g_killers[i] = [0, 0];
|
|
}
|
|
|
|
g_hashTable = new Array(g_hashSize);
|
|
|
|
for (i = 0; i < 32; i++) {
|
|
historyTable[i] = new Array(256);
|
|
for (j = 0; j < 256; j++)
|
|
historyTable[i][j] = 0;
|
|
}
|
|
|
|
var mt = new MT(0x1badf00d);
|
|
|
|
g_zobristLow = new Array(256);
|
|
g_zobristHigh = new Array(256);
|
|
for (i = 0; i < 256; i++) {
|
|
g_zobristLow[i] = new Array(16);
|
|
g_zobristHigh[i] = new Array(16);
|
|
for (j = 0; j < 16; j++) {
|
|
g_zobristLow[i][j] = mt.next(32);
|
|
g_zobristHigh[i][j] = mt.next(32);
|
|
}
|
|
}
|
|
g_zobristBlackLow = mt.next(32);
|
|
g_zobristBlackHigh = mt.next(32);
|
|
|
|
for (row = 0; row < 8; row++) {
|
|
for (col = 0; col < 8; col++) {
|
|
square = MakeSquare(row, col);
|
|
flipTable[square] = MakeSquare(7 - row, col);
|
|
}
|
|
}
|
|
|
|
pieceSquareAdj[piecePawn] = MakeTable(pawnAdj);
|
|
pieceSquareAdj[pieceKnight] = MakeTable(knightAdj);
|
|
pieceSquareAdj[pieceBishop] = MakeTable(bishopAdj);
|
|
pieceSquareAdj[pieceRook] = MakeTable(rookAdj);
|
|
pieceSquareAdj[pieceQueen] = MakeTable(emptyAdj);
|
|
pieceSquareAdj[pieceKing] = MakeTable(kingAdj);
|
|
|
|
var pieceDeltas = [[], [], g_knightDeltas, g_bishopDeltas, g_rookDeltas, g_queenDeltas, g_queenDeltas];
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
g_vectorDelta[i] = {};
|
|
g_vectorDelta[i].delta = 0;
|
|
g_vectorDelta[i].pieceMask = new Array(2);
|
|
g_vectorDelta[i].pieceMask[0] = 0;
|
|
g_vectorDelta[i].pieceMask[1] = 0;
|
|
}
|
|
|
|
// Initialize the vector delta table
|
|
for (row = 0; row < 0x80; row += 0x10)
|
|
for (col = 0; col < 0x8; col++) {
|
|
square = row | col;
|
|
// Pawn moves
|
|
var index = square - (square - 17) + 128;
|
|
g_vectorDelta[index].pieceMask[colorWhite >> 3] |= (1 << piecePawn);
|
|
index = square - (square - 15) + 128;
|
|
g_vectorDelta[index].pieceMask[colorWhite >> 3] |= (1 << piecePawn);
|
|
|
|
index = square - (square + 17) + 128;
|
|
g_vectorDelta[index].pieceMask[0] |= (1 << piecePawn);
|
|
index = square - (square + 15) + 128;
|
|
g_vectorDelta[index].pieceMask[0] |= (1 << piecePawn);
|
|
|
|
for (i = pieceKnight; i <= pieceKing; i++) {
|
|
for (var dir = 0; dir < pieceDeltas[i].length; dir++) {
|
|
var target = square + pieceDeltas[i][dir];
|
|
while (!(target & 0x88)) {
|
|
index = square - target + 128;
|
|
|
|
g_vectorDelta[index].pieceMask[colorWhite >> 3] |= (1 << i);
|
|
g_vectorDelta[index].pieceMask[0] |= (1 << i);
|
|
|
|
var flip = -1;
|
|
if (square < target)
|
|
flip = 1;
|
|
|
|
if ((square & 0xF0) == (target & 0xF0)) {
|
|
// On the same row
|
|
g_vectorDelta[index].delta = flip * 1;
|
|
} else if ((square & 0x0F) == (target & 0x0F)) {
|
|
// On the same column
|
|
g_vectorDelta[index].delta = flip * 16;
|
|
} else if ((square % 15) == (target % 15)) {
|
|
g_vectorDelta[index].delta = flip * 15;
|
|
} else if ((square % 17) == (target % 17)) {
|
|
g_vectorDelta[index].delta = flip * 17;
|
|
}
|
|
|
|
if (i == pieceKnight) {
|
|
g_vectorDelta[index].delta = pieceDeltas[i][dir];
|
|
break;
|
|
}
|
|
|
|
if (i == pieceKing)
|
|
break;
|
|
|
|
target += pieceDeltas[i][dir];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
InitializeEval();
|
|
InitializeFromFen("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1");
|
|
}
|
|
|
|
function InitializeEval() {
|
|
g_mobUnit = new Array(2);
|
|
for (var i = 0; i < 2; i++) {
|
|
g_mobUnit[i] = [];
|
|
var enemy = i === 0 ? 0x10 : 8;
|
|
var friend = i === 0 ? 8 : 0x10;
|
|
g_mobUnit[i][0] = 1;
|
|
g_mobUnit[i][0x80] = 0;
|
|
g_mobUnit[i][enemy | piecePawn] = 1;
|
|
g_mobUnit[i][enemy | pieceBishop] = 2;
|
|
g_mobUnit[i][enemy | pieceKnight] = 2;
|
|
g_mobUnit[i][enemy | pieceRook] = 4;
|
|
g_mobUnit[i][enemy | pieceQueen] = 6;
|
|
g_mobUnit[i][enemy | pieceKing] = 6;
|
|
g_mobUnit[i][friend | piecePawn] = 0;
|
|
g_mobUnit[i][friend | pieceBishop] = 0;
|
|
g_mobUnit[i][friend | pieceKnight] = 0;
|
|
g_mobUnit[i][friend | pieceRook] = 0;
|
|
g_mobUnit[i][friend | pieceQueen] = 0;
|
|
g_mobUnit[i][friend | pieceKing] = 0;
|
|
}
|
|
}
|
|
|
|
function SetHash() {
|
|
var result = {};
|
|
result.hashKeyLow = 0;
|
|
result.hashKeyHigh = 0;
|
|
|
|
for (var i = 0; i < 256; i++) {
|
|
var piece = g_board[i];
|
|
if (piece & 0x18) {
|
|
result.hashKeyLow ^= g_zobristLow[i][piece & 0xF];
|
|
result.hashKeyHigh ^= g_zobristHigh[i][piece & 0xF];
|
|
}
|
|
}
|
|
|
|
if (!g_toMove) {
|
|
result.hashKeyLow ^= g_zobristBlackLow;
|
|
result.hashKeyHigh ^= g_zobristBlackHigh;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
function InitializeFromFen(fen) {
|
|
var i;
|
|
var row = 0;
|
|
var col = 0;
|
|
var chunks = fen.split(' ');
|
|
|
|
for (i = 0; i < 256; i++)
|
|
g_board[i] = 0x80;
|
|
|
|
|
|
var pieces = chunks[0];
|
|
for (i = 0; i < pieces.length; i++) {
|
|
var c = pieces.charAt(i);
|
|
|
|
if (c == '/') {
|
|
row++;
|
|
col = 0;
|
|
}
|
|
else {
|
|
if (c >= '0' && c <= '9') {
|
|
for (var j = 0; j < parseInt(c,10); j++) {
|
|
g_board[MakeSquare(row, col)] = 0;
|
|
col++;
|
|
}
|
|
}
|
|
else {
|
|
var isBlack = c >= 'a' && c <= 'z';
|
|
var piece = isBlack ? colorBlack : colorWhite;
|
|
if (!isBlack)
|
|
c = pieces.toLowerCase().charAt(i);
|
|
switch (c) {
|
|
case 'p':
|
|
piece |= piecePawn;
|
|
break;
|
|
case 'b':
|
|
piece |= pieceBishop;
|
|
break;
|
|
case 'n':
|
|
piece |= pieceKnight;
|
|
break;
|
|
case 'r':
|
|
piece |= pieceRook;
|
|
break;
|
|
case 'q':
|
|
piece |= pieceQueen;
|
|
break;
|
|
case 'k':
|
|
piece |= pieceKing;
|
|
break;
|
|
}
|
|
|
|
g_board[MakeSquare(row, col)] = piece;
|
|
col++;
|
|
}
|
|
}
|
|
}
|
|
|
|
InitializePieceList();
|
|
|
|
g_toMove = chunks[1].charAt(0) == 'w' ? colorWhite : 0;
|
|
var them = 8 - g_toMove;
|
|
|
|
g_castleRights = 0;
|
|
if (chunks[2].indexOf('K') != -1) {
|
|
if (g_board[MakeSquare(7, 4)] != (pieceKing | colorWhite) ||
|
|
g_board[MakeSquare(7, 7)] != (pieceRook | colorWhite)) {
|
|
return 'Invalid FEN: White kingside castling not allowed';
|
|
}
|
|
g_castleRights |= 1;
|
|
}
|
|
if (chunks[2].indexOf('Q') != -1) {
|
|
if (g_board[MakeSquare(7, 4)] != (pieceKing | colorWhite) ||
|
|
g_board[MakeSquare(7, 0)] != (pieceRook | colorWhite)) {
|
|
return 'Invalid FEN: White queenside castling not allowed';
|
|
}
|
|
g_castleRights |= 2;
|
|
}
|
|
if (chunks[2].indexOf('k') != -1) {
|
|
if (g_board[MakeSquare(0, 4)] != (pieceKing | colorBlack) ||
|
|
g_board[MakeSquare(0, 7)] != (pieceRook | colorBlack)) {
|
|
return 'Invalid FEN: Black kingside castling not allowed';
|
|
}
|
|
g_castleRights |= 4;
|
|
}
|
|
if (chunks[2].indexOf('q') != -1) {
|
|
if (g_board[MakeSquare(0, 4)] != (pieceKing | colorBlack) ||
|
|
g_board[MakeSquare(0, 0)] != (pieceRook | colorBlack)) {
|
|
return 'Invalid FEN: Black queenside castling not allowed';
|
|
}
|
|
g_castleRights |= 8;
|
|
}
|
|
|
|
g_enPassentSquare = -1;
|
|
if (chunks[3].indexOf('-') == -1) {
|
|
col = chunks[3].charAt(0).charCodeAt() - 'a'.charCodeAt();
|
|
row = 8 - (chunks[3].charAt(1).charCodeAt() - '0'.charCodeAt());
|
|
g_enPassentSquare = MakeSquare(row, col);
|
|
}
|
|
|
|
var hashResult = SetHash();
|
|
g_hashKeyLow = hashResult.hashKeyLow;
|
|
g_hashKeyHigh = hashResult.hashKeyHigh;
|
|
|
|
g_baseEval = 0;
|
|
for (i = 0; i < 256; i++) {
|
|
if (g_board[i] & colorWhite) {
|
|
g_baseEval += pieceSquareAdj[g_board[i] & 0x7][i];
|
|
g_baseEval += materialTable[g_board[i] & 0x7];
|
|
} else if (g_board[i] & colorBlack) {
|
|
g_baseEval -= pieceSquareAdj[g_board[i] & 0x7][flipTable[i]];
|
|
g_baseEval -= materialTable[g_board[i] & 0x7];
|
|
}
|
|
}
|
|
if (!g_toMove) g_baseEval = -g_baseEval;
|
|
|
|
g_move50 = 0;
|
|
g_inCheck = IsSquareAttackable(g_pieceList[(g_toMove | pieceKing) << 4], them);
|
|
|
|
// Check for king capture (invalid FEN)
|
|
if (IsSquareAttackable(g_pieceList[(them | pieceKing) << 4], g_toMove)) {
|
|
return 'Invalid FEN: Can capture king';
|
|
}
|
|
|
|
// Checkmate/stalemate
|
|
if (GenerateValidMoves().length === 0) {
|
|
return g_inCheck ? 'Checkmate' : 'Stalemate';
|
|
}
|
|
|
|
return '';
|
|
}
|
|
|
|
var g_pieceIndex = new Array(256);
|
|
var g_pieceList = new Array(2 * 8 * 16);
|
|
var g_pieceCount = new Array(2 * 8);
|
|
|
|
function InitializePieceList() {
|
|
var i;
|
|
for (i = 0; i < 16; i++) {
|
|
g_pieceCount[i] = 0;
|
|
for (var j = 0; j < 16; j++) {
|
|
// 0 is used as the terminator for piece lists
|
|
g_pieceList[(i << 4) | j] = 0;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
g_pieceIndex[i] = 0;
|
|
if (g_board[i] & (colorWhite | colorBlack)) {
|
|
var piece = g_board[i] & 0xF;
|
|
|
|
g_pieceList[(piece << 4) | g_pieceCount[piece]] = i;
|
|
g_pieceIndex[i] = g_pieceCount[piece];
|
|
g_pieceCount[piece]++;
|
|
}
|
|
}
|
|
}
|
|
|
|
function MakeMove(move){
|
|
// move format:
|
|
// --flags-- ---to---- --from---
|
|
// 0000 0000 0000 0000 0000 0000
|
|
|
|
// g_board is a 256x256 array
|
|
// representing the chess board
|
|
// right in the middle of it
|
|
|
|
// moveflagEPC = 0000 0010 0000 0000 0000 0000
|
|
// moveflagCastleKing = 0000 0100 0000 0000 0000 0000
|
|
// moveflagCastleQueen = 0000 1000 0000 0000 0000 0000
|
|
|
|
// moveflagPromotion = 0001 0000 0000 0000 0000 0000
|
|
// moveflagPromoteRook = 0000 0000 0000 0000 0000 0000
|
|
// moveflagPromoteKnight = 0010 0000 0000 0000 0000 0000
|
|
// moveflagPromoteQueen = 0100 0000 0000 0000 0000 0000
|
|
// moveflagPromoteBishop = 1000 0000 0000 0000 0000 0000
|
|
|
|
|
|
var me = g_toMove >> 3;
|
|
var otherColor = 8 - g_toMove;
|
|
|
|
var flags = move & 0xFF0000;
|
|
var to = (move >> 8) & 0xFF;
|
|
var from = move & 0xFF;
|
|
var captured = g_board[to];
|
|
var piece = g_board[from];
|
|
var epcEnd = to;
|
|
var rook, rookIndex;
|
|
|
|
if (flags & moveflagEPC) {
|
|
epcEnd = me ? (to + 0x10) : (to - 0x10);
|
|
captured = g_board[epcEnd];
|
|
g_board[epcEnd] = pieceEmpty;
|
|
}
|
|
|
|
g_moveUndoStack[g_moveCount] = new UndoHistory(g_enPassentSquare, g_castleRights, g_inCheck, g_baseEval, g_hashKeyLow, g_hashKeyHigh, g_move50, captured);
|
|
g_moveCount++;
|
|
|
|
g_enPassentSquare = -1;
|
|
|
|
if (flags) {
|
|
if (flags & moveflagCastleKing) {
|
|
if (IsSquareAttackable(from + 1, otherColor) ||
|
|
IsSquareAttackable(from + 2, otherColor)) {
|
|
g_moveCount--;
|
|
return false;
|
|
}
|
|
|
|
rook = g_board[to + 1];
|
|
|
|
g_hashKeyLow ^= g_zobristLow[to + 1][rook & 0xF];
|
|
g_hashKeyHigh ^= g_zobristHigh[to + 1][rook & 0xF];
|
|
g_hashKeyLow ^= g_zobristLow[to - 1][rook & 0xF];
|
|
g_hashKeyHigh ^= g_zobristHigh[to - 1][rook & 0xF];
|
|
|
|
g_board[to - 1] = rook;
|
|
g_board[to + 1] = pieceEmpty;
|
|
|
|
g_baseEval -= pieceSquareAdj[rook & 0x7][me === 0 ? flipTable[to + 1] : (to + 1)];
|
|
g_baseEval += pieceSquareAdj[rook & 0x7][me === 0 ? flipTable[to - 1] : (to - 1)];
|
|
|
|
rookIndex = g_pieceIndex[to + 1];
|
|
g_pieceIndex[to - 1] = rookIndex;
|
|
g_pieceList[((rook & 0xF) << 4) | rookIndex] = to - 1;
|
|
} else if (flags & moveflagCastleQueen) {
|
|
if (IsSquareAttackable(from - 1, otherColor) ||
|
|
IsSquareAttackable(from - 2, otherColor)) {
|
|
g_moveCount--;
|
|
return false;
|
|
}
|
|
|
|
rook = g_board[to - 2];
|
|
|
|
g_hashKeyLow ^= g_zobristLow[to -2][rook & 0xF];
|
|
g_hashKeyHigh ^= g_zobristHigh[to - 2][rook & 0xF];
|
|
g_hashKeyLow ^= g_zobristLow[to + 1][rook & 0xF];
|
|
g_hashKeyHigh ^= g_zobristHigh[to + 1][rook & 0xF];
|
|
|
|
g_board[to + 1] = rook;
|
|
g_board[to - 2] = pieceEmpty;
|
|
|
|
g_baseEval -= pieceSquareAdj[rook & 0x7][me === 0 ? flipTable[to - 2] : (to - 2)];
|
|
g_baseEval += pieceSquareAdj[rook & 0x7][me === 0 ? flipTable[to + 1] : (to + 1)];
|
|
|
|
rookIndex = g_pieceIndex[to - 2];
|
|
g_pieceIndex[to + 1] = rookIndex;
|
|
g_pieceList[((rook & 0xF) << 4) | rookIndex] = to + 1;
|
|
}
|
|
}
|
|
|
|
if ((captured & 0x7) > 0) {
|
|
// Remove our piece from the piece list
|
|
var capturedType = captured & 0xF;
|
|
g_pieceCount[capturedType]--;
|
|
var lastPieceSquare = g_pieceList[(capturedType << 4) | g_pieceCount[capturedType]];
|
|
g_pieceIndex[lastPieceSquare] = g_pieceIndex[epcEnd];
|
|
g_pieceList[(capturedType << 4) | g_pieceIndex[lastPieceSquare]] = lastPieceSquare;
|
|
g_pieceList[(capturedType << 4) | g_pieceCount[capturedType]] = 0;
|
|
|
|
g_baseEval += materialTable[captured & 0x7];
|
|
g_baseEval += pieceSquareAdj[captured & 0x7][me ? flipTable[epcEnd] : epcEnd];
|
|
|
|
g_hashKeyLow ^= g_zobristLow[epcEnd][capturedType];
|
|
g_hashKeyHigh ^= g_zobristHigh[epcEnd][capturedType];
|
|
g_move50 = 0;
|
|
} else if ((piece & 0x7) == piecePawn) {
|
|
var diff = to - from;
|
|
if (diff < 0) diff = -diff;
|
|
if (diff > 16) {
|
|
g_enPassentSquare = me ? (to + 0x10) : (to - 0x10);
|
|
}
|
|
g_move50 = 0;
|
|
}
|
|
|
|
g_hashKeyLow ^= g_zobristLow[from][piece & 0xF];
|
|
g_hashKeyHigh ^= g_zobristHigh[from][piece & 0xF];
|
|
g_hashKeyLow ^= g_zobristLow[to][piece & 0xF];
|
|
g_hashKeyHigh ^= g_zobristHigh[to][piece & 0xF];
|
|
g_hashKeyLow ^= g_zobristBlackLow;
|
|
g_hashKeyHigh ^= g_zobristBlackHigh;
|
|
|
|
g_castleRights &= g_castleRightsMask[from] & g_castleRightsMask[to];
|
|
|
|
g_baseEval -= pieceSquareAdj[piece & 0x7][me === 0 ? flipTable[from] : from];
|
|
|
|
// Move our piece in the piece list
|
|
g_pieceIndex[to] = g_pieceIndex[from];
|
|
g_pieceList[((piece & 0xF) << 4) | g_pieceIndex[to]] = to;
|
|
|
|
if (flags & moveflagPromotion) {
|
|
var newPiece = piece & (~0x7);
|
|
if (flags & moveflagPromoteKnight)
|
|
newPiece |= pieceKnight;
|
|
else if (flags & moveflagPromoteQueen)
|
|
newPiece |= pieceQueen;
|
|
else if (flags & moveflagPromoteBishop)
|
|
newPiece |= pieceBishop;
|
|
else
|
|
newPiece |= pieceRook;
|
|
|
|
g_hashKeyLow ^= g_zobristLow[to][piece & 0xF];
|
|
g_hashKeyHigh ^= g_zobristHigh[to][piece & 0xF];
|
|
g_board[to] = newPiece;
|
|
g_hashKeyLow ^= g_zobristLow[to][newPiece & 0xF];
|
|
g_hashKeyHigh ^= g_zobristHigh[to][newPiece & 0xF];
|
|
|
|
g_baseEval += pieceSquareAdj[newPiece & 0x7][me === 0 ? flipTable[to] : to];
|
|
g_baseEval -= materialTable[piecePawn];
|
|
g_baseEval += materialTable[newPiece & 0x7];
|
|
|
|
var pawnType = piece & 0xF;
|
|
var promoteType = newPiece & 0xF;
|
|
|
|
g_pieceCount[pawnType]--;
|
|
|
|
var lastPawnSquare = g_pieceList[(pawnType << 4) | g_pieceCount[pawnType]];
|
|
g_pieceIndex[lastPawnSquare] = g_pieceIndex[to];
|
|
g_pieceList[(pawnType << 4) | g_pieceIndex[lastPawnSquare]] = lastPawnSquare;
|
|
g_pieceList[(pawnType << 4) | g_pieceCount[pawnType]] = 0;
|
|
g_pieceIndex[to] = g_pieceCount[promoteType];
|
|
g_pieceList[(promoteType << 4) | g_pieceIndex[to]] = to;
|
|
g_pieceCount[promoteType]++;
|
|
} else {
|
|
g_board[to] = g_board[from];
|
|
|
|
g_baseEval += pieceSquareAdj[piece & 0x7][me === 0 ? flipTable[to] : to];
|
|
}
|
|
g_board[from] = pieceEmpty;
|
|
|
|
g_toMove = otherColor;
|
|
g_baseEval = -g_baseEval;
|
|
|
|
if ((piece & 0x7) == pieceKing || g_inCheck) {
|
|
if (IsSquareAttackable(g_pieceList[(pieceKing | (8 - g_toMove)) << 4], otherColor)) {
|
|
UnmakeMove(move);
|
|
return false;
|
|
}
|
|
} else {
|
|
var kingPos = g_pieceList[(pieceKing | (8 - g_toMove)) << 4];
|
|
|
|
if (ExposesCheck(from, kingPos)) {
|
|
UnmakeMove(move);
|
|
return false;
|
|
}
|
|
|
|
if (epcEnd != to) {
|
|
if (ExposesCheck(epcEnd, kingPos)) {
|
|
UnmakeMove(move);
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
g_inCheck = false;
|
|
|
|
if (flags <= moveflagEPC) {
|
|
var theirKingPos = g_pieceList[(pieceKing | g_toMove) << 4];
|
|
|
|
// First check if the piece we moved can attack the enemy king
|
|
g_inCheck = IsSquareAttackableFrom(theirKingPos, to);
|
|
|
|
if (!g_inCheck) {
|
|
// Now check if the square we moved from exposes check on the enemy king
|
|
g_inCheck = ExposesCheck(from, theirKingPos);
|
|
|
|
if (!g_inCheck) {
|
|
// Finally, ep. capture can cause another square to be exposed
|
|
if (epcEnd != to) {
|
|
g_inCheck = ExposesCheck(epcEnd, theirKingPos);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
// Castle or promotion, slow check
|
|
g_inCheck = IsSquareAttackable(g_pieceList[(pieceKing | g_toMove) << 4], 8 - g_toMove);
|
|
}
|
|
|
|
g_repMoveStack[g_moveCount - 1] = g_hashKeyLow;
|
|
g_move50++;
|
|
|
|
return true;
|
|
}
|
|
|
|
function UnmakeMove(move){
|
|
|
|
g_toMove = 8 - g_toMove;
|
|
g_baseEval = -g_baseEval;
|
|
|
|
g_moveCount--;
|
|
g_enPassentSquare = g_moveUndoStack[g_moveCount].ep;
|
|
g_castleRights = g_moveUndoStack[g_moveCount].castleRights;
|
|
g_inCheck = g_moveUndoStack[g_moveCount].inCheck;
|
|
g_baseEval = g_moveUndoStack[g_moveCount].baseEval;
|
|
g_hashKeyLow = g_moveUndoStack[g_moveCount].hashKeyLow;
|
|
g_hashKeyHigh = g_moveUndoStack[g_moveCount].hashKeyHigh;
|
|
g_move50 = g_moveUndoStack[g_moveCount].move50;
|
|
|
|
var otherColor = 8 - g_toMove;
|
|
var me = g_toMove >> 3;
|
|
var them = otherColor >> 3;
|
|
|
|
var flags = move & 0xFF0000;
|
|
var captured = g_moveUndoStack[g_moveCount].captured;
|
|
var to = (move >> 8) & 0xFF;
|
|
var from = move & 0xFF;
|
|
|
|
var piece = g_board[to];
|
|
var rook,rookIndex;
|
|
|
|
if (flags) {
|
|
if (flags & moveflagCastleKing) {
|
|
rook = g_board[to - 1];
|
|
g_board[to + 1] = rook;
|
|
g_board[to - 1] = pieceEmpty;
|
|
|
|
rookIndex = g_pieceIndex[to - 1];
|
|
g_pieceIndex[to + 1] = rookIndex;
|
|
g_pieceList[((rook & 0xF) << 4) | rookIndex] = to + 1;
|
|
}
|
|
else if (flags & moveflagCastleQueen) {
|
|
rook = g_board[to + 1];
|
|
g_board[to - 2] = rook;
|
|
g_board[to + 1] = pieceEmpty;
|
|
|
|
rookIndex = g_pieceIndex[to + 1];
|
|
g_pieceIndex[to - 2] = rookIndex;
|
|
g_pieceList[((rook & 0xF) << 4) | rookIndex] = to - 2;
|
|
}
|
|
}
|
|
|
|
if (flags & moveflagPromotion) {
|
|
piece = (g_board[to] & (~0x7)) | piecePawn;
|
|
g_board[from] = piece;
|
|
|
|
var pawnType = g_board[from] & 0xF;
|
|
var promoteType = g_board[to] & 0xF;
|
|
|
|
g_pieceCount[promoteType]--;
|
|
|
|
var lastPromoteSquare = g_pieceList[(promoteType << 4) | g_pieceCount[promoteType]];
|
|
g_pieceIndex[lastPromoteSquare] = g_pieceIndex[to];
|
|
g_pieceList[(promoteType << 4) | g_pieceIndex[lastPromoteSquare]] = lastPromoteSquare;
|
|
g_pieceList[(promoteType << 4) | g_pieceCount[promoteType]] = 0;
|
|
g_pieceIndex[to] = g_pieceCount[pawnType];
|
|
g_pieceList[(pawnType << 4) | g_pieceIndex[to]] = to;
|
|
g_pieceCount[pawnType]++;
|
|
}
|
|
else {
|
|
g_board[from] = g_board[to];
|
|
}
|
|
|
|
var epcEnd = to;
|
|
if (flags & moveflagEPC) {
|
|
if (g_toMove == colorWhite)
|
|
epcEnd = to + 0x10;
|
|
else
|
|
epcEnd = to - 0x10;
|
|
g_board[to] = pieceEmpty;
|
|
}
|
|
|
|
g_board[epcEnd] = captured;
|
|
|
|
// Move our piece in the piece list
|
|
g_pieceIndex[from] = g_pieceIndex[to];
|
|
g_pieceList[((piece & 0xF) << 4) | g_pieceIndex[from]] = from;
|
|
|
|
if (captured) {
|
|
// Restore our piece to the piece list
|
|
var captureType = captured & 0xF;
|
|
g_pieceIndex[epcEnd] = g_pieceCount[captureType];
|
|
g_pieceList[(captureType << 4) | g_pieceCount[captureType]] = epcEnd;
|
|
g_pieceCount[captureType]++;
|
|
}
|
|
}
|
|
|
|
function ExposesCheck(from, kingPos){
|
|
var index = kingPos - from + 128;
|
|
// If a queen can't reach it, nobody can!
|
|
if ((g_vectorDelta[index].pieceMask[0] & (1 << (pieceQueen))) !== 0) {
|
|
var delta = g_vectorDelta[index].delta;
|
|
var pos = kingPos + delta;
|
|
while (g_board[pos] === 0) pos += delta;
|
|
|
|
var piece = g_board[pos];
|
|
if (((piece & (g_board[kingPos] ^ 0x18)) & 0x18) === 0)
|
|
return false;
|
|
|
|
// Now see if the piece can actually attack the king
|
|
var backwardIndex = pos - kingPos + 128;
|
|
return (g_vectorDelta[backwardIndex].pieceMask[(piece >> 3) & 1] & (1 << (piece & 0x7))) !== 0;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
function IsSquareOnPieceLine(target, from) {
|
|
var index = from - target + 128;
|
|
var piece = g_board[from];
|
|
return (g_vectorDelta[index].pieceMask[(piece >> 3) & 1] & (1 << (piece & 0x7))) ? true : false;
|
|
}
|
|
|
|
function IsSquareAttackableFrom(target, from){
|
|
var index = from - target + 128;
|
|
var piece = g_board[from];
|
|
if (g_vectorDelta[index].pieceMask[(piece >> 3) & 1] & (1 << (piece & 0x7))) {
|
|
// Yes, this square is pseudo-attackable. Now, check for real attack
|
|
var inc = g_vectorDelta[index].delta;
|
|
do {
|
|
from += inc;
|
|
if (from == target)
|
|
return true;
|
|
} while (g_board[from] === 0);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
function IsSquareAttackable(target, color) {
|
|
// Attackable by pawns?
|
|
var inc = color ? -16 : 16;
|
|
var pawn = (color ? colorWhite : colorBlack) | 1;
|
|
if (g_board[target - (inc - 1)] == pawn)
|
|
return true;
|
|
if (g_board[target - (inc + 1)] == pawn)
|
|
return true;
|
|
|
|
// Attackable by pieces?
|
|
for (var i = 2; i <= 6; i++) {
|
|
var index = (color | i) << 4;
|
|
var square = g_pieceList[index];
|
|
while (square !== 0) {
|
|
if (IsSquareAttackableFrom(target, square))
|
|
return true;
|
|
square = g_pieceList[++index];
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
function GenerateMove(from, to) {
|
|
return from | (to << 8);
|
|
}
|
|
|
|
function GenerateMove(from, to, flags){
|
|
return from | (to << 8) | flags;
|
|
}
|
|
|
|
function GenerateValidMoves() {
|
|
var moveList = [];
|
|
var allMoves = [];
|
|
GenerateCaptureMoves(allMoves, null);
|
|
GenerateAllMoves(allMoves);
|
|
|
|
for (var i = allMoves.length - 1; i >= 0; i--) {
|
|
if (MakeMove(allMoves[i])) {
|
|
moveList[moveList.length] = allMoves[i];
|
|
UnmakeMove(allMoves[i]);
|
|
} else {
|
|
}
|
|
}
|
|
|
|
return moveList;
|
|
}
|
|
|
|
function GenerateAllMoves(moveStack) {
|
|
var from, to, piece, pieceIdx;
|
|
|
|
// Pawn quiet moves
|
|
pieceIdx = (g_toMove | 1) << 4;
|
|
from = g_pieceList[pieceIdx++];
|
|
while (from !== 0) {
|
|
GeneratePawnMoves(moveStack, from);
|
|
from = g_pieceList[pieceIdx++];
|
|
}
|
|
|
|
// Knight quiet moves
|
|
pieceIdx = (g_toMove | 2) << 4;
|
|
from = g_pieceList[pieceIdx++];
|
|
while (from !== 0) {
|
|
to = from + 31;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 33;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 14;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 14;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 31;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 33;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 18;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 18;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
from = g_pieceList[pieceIdx++];
|
|
}
|
|
|
|
// Bishop quiet moves
|
|
pieceIdx = (g_toMove | 3) << 4;
|
|
from = g_pieceList[pieceIdx++];
|
|
while (from !== 0) {
|
|
to = from - 15;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to -= 15; }
|
|
to = from - 17;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to -= 17; }
|
|
to = from + 15;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to += 15; }
|
|
to = from + 17;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to += 17; }
|
|
from = g_pieceList[pieceIdx++];
|
|
}
|
|
|
|
// Rook quiet moves
|
|
pieceIdx = (g_toMove | 4) << 4;
|
|
from = g_pieceList[pieceIdx++];
|
|
while (from !== 0) {
|
|
to = from - 1;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to--; }
|
|
to = from + 1;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to++; }
|
|
to = from + 16;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to += 16; }
|
|
to = from - 16;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to -= 16; }
|
|
from = g_pieceList[pieceIdx++];
|
|
}
|
|
|
|
// Queen quiet moves
|
|
pieceIdx = (g_toMove | 5) << 4;
|
|
from = g_pieceList[pieceIdx++];
|
|
while (from !== 0) {
|
|
to = from - 15;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to -= 15; }
|
|
to = from - 17;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to -= 17; }
|
|
to = from + 15;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to += 15; }
|
|
to = from + 17;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to += 17; }
|
|
to = from - 1;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to--; }
|
|
to = from + 1;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to++; }
|
|
to = from + 16;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to += 16; }
|
|
to = from - 16;
|
|
while (g_board[to] === 0) { moveStack[moveStack.length] = GenerateMove(from, to); to -= 16; }
|
|
from = g_pieceList[pieceIdx++];
|
|
}
|
|
|
|
// King quiet moves
|
|
pieceIdx = (g_toMove | 6) << 4;
|
|
from = g_pieceList[pieceIdx];
|
|
to = from - 15;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 17;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 15;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 17;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 1;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 1;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 16;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 16;
|
|
if (g_board[to] === 0) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
|
|
if (!g_inCheck) {
|
|
var castleRights = g_castleRights;
|
|
if (!g_toMove)
|
|
castleRights >>= 2;
|
|
if (castleRights & 1) {
|
|
// Kingside castle
|
|
if (g_board[from + 1] == pieceEmpty && g_board[from + 2] == pieceEmpty) {
|
|
moveStack[moveStack.length] = GenerateMove(from, from + 0x02, moveflagCastleKing);
|
|
}
|
|
}
|
|
if (castleRights & 2) {
|
|
// Queenside castle
|
|
if (g_board[from - 1] == pieceEmpty && g_board[from - 2] == pieceEmpty && g_board[from - 3] == pieceEmpty) {
|
|
moveStack[moveStack.length] = GenerateMove(from, from - 0x02, moveflagCastleQueen);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
function GenerateCaptureMoves(moveStack, moveScores) {
|
|
var from, to, piece, pieceIdx;
|
|
var inc = (g_toMove == 8) ? -16 : 16;
|
|
var enemy = g_toMove == 8 ? 0x10 : 0x8;
|
|
|
|
// Pawn captures
|
|
pieceIdx = (g_toMove | 1) << 4;
|
|
from = g_pieceList[pieceIdx++];
|
|
while (from !== 0) {
|
|
to = from + inc - 1;
|
|
if (g_board[to] & enemy) {
|
|
MovePawnTo(moveStack, from, to);
|
|
}
|
|
|
|
to = from + inc + 1;
|
|
if (g_board[to] & enemy) {
|
|
MovePawnTo(moveStack, from, to);
|
|
}
|
|
|
|
from = g_pieceList[pieceIdx++];
|
|
}
|
|
|
|
if (g_enPassentSquare !== -1) {
|
|
inc = (g_toMove === colorWhite) ? -16 : 16;
|
|
var pawn = g_toMove | piecePawn;
|
|
|
|
from = g_enPassentSquare - (inc + 1);
|
|
if ((g_board[from] & 0xF) === pawn) {
|
|
moveStack[moveStack.length] = GenerateMove(from, g_enPassentSquare, moveflagEPC);
|
|
}
|
|
|
|
from = g_enPassentSquare - (inc - 1);
|
|
if ((g_board[from] & 0xF) === pawn) {
|
|
moveStack[moveStack.length] = GenerateMove(from, g_enPassentSquare, moveflagEPC);
|
|
}
|
|
}
|
|
|
|
// Knight captures
|
|
pieceIdx = (g_toMove | 2) << 4;
|
|
from = g_pieceList[pieceIdx++];
|
|
while (from !== 0) {
|
|
to = from + 31;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 33;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 14;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 14;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 31;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 33;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 18;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 18;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
from = g_pieceList[pieceIdx++];
|
|
}
|
|
|
|
// Bishop captures
|
|
pieceIdx = (g_toMove | 3) << 4;
|
|
from = g_pieceList[pieceIdx++];
|
|
while (from !== 0) {
|
|
to = from;
|
|
do { to -= 15; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to -= 17; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to += 15; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to += 17; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
from = g_pieceList[pieceIdx++];
|
|
}
|
|
|
|
// Rook captures
|
|
pieceIdx = (g_toMove | 4) << 4;
|
|
from = g_pieceList[pieceIdx++];
|
|
while (from !== 0) {
|
|
to = from;
|
|
do { to--; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to++; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to -= 16; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to += 16; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
from = g_pieceList[pieceIdx++];
|
|
}
|
|
|
|
// Queen captures
|
|
pieceIdx = (g_toMove | 5) << 4;
|
|
from = g_pieceList[pieceIdx++];
|
|
while (from !== 0) {
|
|
to = from;
|
|
do { to -= 15; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to -= 17; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to += 15; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to += 17; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to--; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to++; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to -= 16; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from;
|
|
do { to += 16; } while (g_board[to] === 0);
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
from = g_pieceList[pieceIdx++];
|
|
}
|
|
|
|
// King captures
|
|
pieceIdx = (g_toMove | 6) << 4;
|
|
from = g_pieceList[pieceIdx];
|
|
to = from - 15;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 17;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 15;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 17;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 1;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 1;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from - 16;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
to = from + 16;
|
|
if (g_board[to] & enemy) moveStack[moveStack.length] = GenerateMove(from, to);
|
|
}
|
|
|
|
function MovePawnTo(moveStack, start, square) {
|
|
var row = square & 0xF0;
|
|
if ((row == 0x90) || (row == 0x20)) {
|
|
moveStack[moveStack.length] = GenerateMove(start, square, moveflagPromotion | moveflagPromoteQueen);
|
|
moveStack[moveStack.length] = GenerateMove(start, square, moveflagPromotion | moveflagPromoteKnight);
|
|
moveStack[moveStack.length] = GenerateMove(start, square, moveflagPromotion | moveflagPromoteBishop);
|
|
moveStack[moveStack.length] = GenerateMove(start, square, moveflagPromotion);
|
|
}
|
|
else {
|
|
moveStack[moveStack.length] = GenerateMove(start, square, 0);
|
|
}
|
|
}
|
|
|
|
function GeneratePawnMoves(moveStack, from) {
|
|
var piece = g_board[from];
|
|
var color = piece & colorWhite;
|
|
var inc = (color === colorWhite) ? -16 : 16;
|
|
|
|
// Quiet pawn moves
|
|
var to = from + inc;
|
|
if (g_board[to] === 0) {
|
|
MovePawnTo(moveStack, from, to, pieceEmpty);
|
|
|
|
// Check if we can do a 2 square jump
|
|
if ((((from & 0xF0) === 0x30) && color !== colorWhite) ||
|
|
(((from & 0xF0) === 0x80) && color === colorWhite)) {
|
|
to += inc;
|
|
if (g_board[to] === 0) {
|
|
moveStack[moveStack.length] = GenerateMove(from, to);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
function UndoHistory(ep, castleRights, inCheck, baseEval, hashKeyLow, hashKeyHigh, move50, captured) {
|
|
this.ep = ep;
|
|
this.castleRights = castleRights;
|
|
this.inCheck = inCheck;
|
|
this.baseEval = baseEval;
|
|
this.hashKeyLow = hashKeyLow;
|
|
this.hashKeyHigh = hashKeyHigh;
|
|
this.move50 = move50;
|
|
this.captured = captured;
|
|
}
|
|
|
|
var g_seeValues = [ 0, 1, 3, 3, 5, 9, 900, 0,
|
|
0, 1, 3, 3, 5, 9, 900, 0];
|
|
|
|
function See(move) {
|
|
var from = move & 0xFF;
|
|
var to = (move >> 8) & 0xFF;
|
|
|
|
var fromPiece = g_board[from];
|
|
|
|
var fromValue = g_seeValues[fromPiece & 0xF];
|
|
var toValue = g_seeValues[g_board[to] & 0xF];
|
|
var pieceType,pieceValue,i;
|
|
|
|
if (fromValue <= toValue) {
|
|
return true;
|
|
}
|
|
|
|
if (move >> 16) {
|
|
// Castles, promotion, ep are always good
|
|
return true;
|
|
}
|
|
|
|
var us = (fromPiece & colorWhite) ? colorWhite : 0;
|
|
var them = 8 - us;
|
|
|
|
// Pawn attacks
|
|
// If any opponent pawns can capture back, this capture is probably not worthwhile (as we must be using knight or above).
|
|
var inc = (fromPiece & colorWhite) ? -16 : 16; // Note: this is capture direction from to, so reversed from normal move direction
|
|
if (((g_board[to + inc + 1] & 0xF) == (piecePawn | them)) ||
|
|
((g_board[to + inc - 1] & 0xF) == (piecePawn | them))) {
|
|
return false;
|
|
}
|
|
|
|
var themAttacks = [];
|
|
|
|
// Knight attacks
|
|
// If any opponent knights can capture back, and the deficit we have to make up is greater than the knights value,
|
|
// it's not worth it. We can capture on this square again, and the opponent doesn't have to capture back.
|
|
var captureDeficit = fromValue - toValue;
|
|
SeeAddKnightAttacks(to, them, themAttacks);
|
|
if (themAttacks.length !== 0 && captureDeficit > g_seeValues[pieceKnight]) {
|
|
return false;
|
|
}
|
|
|
|
// Slider attacks
|
|
g_board[from] = 0;
|
|
for (pieceType = pieceBishop; pieceType <= pieceQueen; pieceType++) {
|
|
if (SeeAddSliderAttacks(to, them, themAttacks, pieceType)) {
|
|
if (captureDeficit > g_seeValues[pieceType]) {
|
|
g_board[from] = fromPiece;
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Pawn defenses
|
|
// At this point, we are sure we are making a "losing" capture. The opponent can not capture back with a
|
|
// pawn. They cannot capture back with a minor/major and stand pat either. So, if we can capture with
|
|
// a pawn, it's got to be a winning or equal capture.
|
|
if (((g_board[to - inc + 1] & 0xF) === (piecePawn | us)) ||
|
|
((g_board[to - inc - 1] & 0xF) === (piecePawn | us))) {
|
|
g_board[from] = fromPiece;
|
|
return true;
|
|
}
|
|
|
|
// King attacks
|
|
SeeAddSliderAttacks(to, them, themAttacks, pieceKing);
|
|
|
|
// Our attacks
|
|
var usAttacks = [];
|
|
SeeAddKnightAttacks(to, us, usAttacks);
|
|
for (pieceType = pieceBishop; pieceType <= pieceKing; pieceType++) {
|
|
SeeAddSliderAttacks(to, us, usAttacks, pieceType);
|
|
}
|
|
|
|
g_board[from] = fromPiece;
|
|
|
|
// We are currently winning the amount of material of the captured piece, time to see if the opponent
|
|
// can get it back somehow. We assume the opponent can capture our current piece in this score, which
|
|
// simplifies the later code considerably.
|
|
var seeValue = toValue - fromValue;
|
|
|
|
for (; ; ) {
|
|
var capturingPieceValue = 1000;
|
|
var capturingPieceIndex = -1;
|
|
|
|
// Find the least valuable piece of the opponent that can attack the square
|
|
for (i = 0; i < themAttacks.length; i++) {
|
|
if (themAttacks[i] !== 0) {
|
|
pieceValue = g_seeValues[g_board[themAttacks[i]] & 0x7];
|
|
if (pieceValue < capturingPieceValue) {
|
|
capturingPieceValue = pieceValue;
|
|
capturingPieceIndex = i;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (capturingPieceIndex == -1) {
|
|
// Opponent can't capture back, we win
|
|
return true;
|
|
}
|
|
|
|
// Now, if seeValue < 0, the opponent is winning. If even after we take their piece,
|
|
// we can't bring it back to 0, then we have lost this battle.
|
|
seeValue += capturingPieceValue;
|
|
if (seeValue < 0) {
|
|
return false;
|
|
}
|
|
|
|
var capturingPieceSquare = themAttacks[capturingPieceIndex];
|
|
themAttacks[capturingPieceIndex] = 0;
|
|
|
|
// Add any x-ray attackers
|
|
SeeAddXrayAttack(to, capturingPieceSquare, us, usAttacks, themAttacks);
|
|
|
|
// Our turn to capture
|
|
capturingPieceValue = 1000;
|
|
capturingPieceIndex = -1;
|
|
|
|
// Find our least valuable piece that can attack the square
|
|
for (i = 0; i < usAttacks.length; i++) {
|
|
if (usAttacks[i] !== 0) {
|
|
pieceValue = g_seeValues[g_board[usAttacks[i]] & 0x7];
|
|
if (pieceValue < capturingPieceValue) {
|
|
capturingPieceValue = pieceValue;
|
|
capturingPieceIndex = i;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (capturingPieceIndex == -1) {
|
|
// We can't capture back, we lose :(
|
|
return false;
|
|
}
|
|
|
|
// Assume our opponent can capture us back, and if we are still winning, we can stand-pat
|
|
// here, and assume we've won.
|
|
seeValue -= capturingPieceValue;
|
|
if (seeValue >= 0) {
|
|
return true;
|
|
}
|
|
|
|
capturingPieceSquare = usAttacks[capturingPieceIndex];
|
|
usAttacks[capturingPieceIndex] = 0;
|
|
|
|
// Add any x-ray attackers
|
|
SeeAddXrayAttack(to, capturingPieceSquare, us, usAttacks, themAttacks);
|
|
}
|
|
}
|
|
|
|
function SeeAddXrayAttack(target, square, us, usAttacks, themAttacks) {
|
|
var index = square - target + 128;
|
|
var delta = -g_vectorDelta[index].delta;
|
|
if (delta === 0)
|
|
return;
|
|
square += delta;
|
|
while (g_board[square] === 0) {
|
|
square += delta;
|
|
}
|
|
|
|
if ((g_board[square] & 0x18) && IsSquareOnPieceLine(target, square)) {
|
|
if ((g_board[square] & 8) == us) {
|
|
usAttacks[usAttacks.length] = square;
|
|
} else {
|
|
themAttacks[themAttacks.length] = square;
|
|
}
|
|
}
|
|
}
|
|
|
|
// target = attacking square, us = color of knights to look for, attacks = array to add squares to
|
|
function SeeAddKnightAttacks(target, us, attacks) {
|
|
var pieceIdx = (us | pieceKnight) << 4;
|
|
var attackerSq = g_pieceList[pieceIdx++];
|
|
|
|
while (attackerSq !== 0) {
|
|
if (IsSquareOnPieceLine(target, attackerSq)) {
|
|
attacks[attacks.length] = attackerSq;
|
|
}
|
|
attackerSq = g_pieceList[pieceIdx++];
|
|
}
|
|
}
|
|
|
|
function SeeAddSliderAttacks(target, us, attacks, pieceType) {
|
|
var pieceIdx = (us | pieceType) << 4;
|
|
var attackerSq = g_pieceList[pieceIdx++];
|
|
var hit = false;
|
|
|
|
while (attackerSq !== 0) {
|
|
if (IsSquareAttackableFrom(target, attackerSq)) {
|
|
attacks[attacks.length] = attackerSq;
|
|
hit = true;
|
|
}
|
|
attackerSq = g_pieceList[pieceIdx++];
|
|
}
|
|
|
|
return hit;
|
|
}
|
|
|
|
function BuildPVMessage(bestMove, value, timeTaken, ply) {
|
|
var totalNodes = g_nodeCount + g_qNodeCount;
|
|
return "Ply:" + ply + " Score:" + value + " Nodes:" + totalNodes + " NPS:" + ((totalNodes / (timeTaken / 1000)) | 0) + " " + PVFromHash(bestMove, 15);
|
|
}
|
|
|
|
//////////////////////////////////////////////////
|
|
// Test Harness
|
|
//////////////////////////////////////////////////
|
|
function FinishPlyCallback(bestMove, value, timeTaken, ply) {
|
|
postMessage("pv " + BuildPVMessage(bestMove, value, timeTaken, ply));
|
|
}
|
|
|
|
function FinishMoveLocalTesting(bestMove, value, timeTaken, ply) {
|
|
if (bestMove !== undefined) {
|
|
MakeMove(bestMove);
|
|
postMessage(FormatMove(bestMove));
|
|
}
|
|
}
|
|
|
|
var needsReset = true;
|
|
self.onmessage = function (e) {
|
|
if (e.data == "go" || needsReset) {
|
|
ResetGame();
|
|
needsReset = false;
|
|
if (e.data == "go") return;
|
|
}
|
|
if (e.data.match("^position") == "position") {
|
|
ResetGame();
|
|
var result = InitializeFromFen(e.data.substr(9, e.data.length - 9));
|
|
if (result.length !== 0) {
|
|
postMessage("message " + result);
|
|
}
|
|
} else if (e.data.match("^search") == "search") {
|
|
var level = e.data.substr(7,e.data.length-7).split(",");
|
|
g_timeout = parseInt(level[0], 10);
|
|
g_maxply = parseInt(level[1], 10);
|
|
Search(FinishMoveLocalTesting, g_maxply, FinishPlyCallback);
|
|
} else if (e.data == "analyze") {
|
|
g_timeout = 99999999999;
|
|
Search(null, g_maxply, FinishPlyCallback);
|
|
} else {
|
|
MakeMove(GetMoveFromString(e.data));
|
|
}
|
|
};
|
|
|
|
function debug(msg) {
|
|
if (g_debug) {
|
|
if(worker) {
|
|
postMessage("console: "+msg);
|
|
} else {
|
|
console.log(msg);
|
|
}
|
|
}
|
|
} |