X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=public%2Fjavascripts%2Fbase_rules.js;h=a10a43ca270f405ff5dde22e0c7ba04170f577c6;hb=331fc58c932d6d7055b202d0c6dc0d77212a89f8;hp=860495a4236c3109bf77874172f353b7b878be2b;hpb=098e8468ae7a52a55850c09f90506f52b8133567;p=vchess.git

diff --git a/public/javascripts/base_rules.js b/public/javascripts/base_rules.js
index 860495a4..a10a43ca 100644
--- a/public/javascripts/base_rules.js
+++ b/public/javascripts/base_rules.js
@@ -1,3 +1,6 @@
+// (Orthodox) Chess rules are defined in ChessRules class.
+// Variants generally inherit from it, and modify some parts.
+
 class PiPo //Piece+Position
 {
 	// o: {piece[p], color[c], posX[x], posY[y]}
@@ -51,6 +54,7 @@ class ChessRules
 	constructor(fen, moves)
 	{
 		this.moves = moves;
+		this.hashStates = {}; //for repetitions detection
 		// Use fen string to initialize variables, flags and board
 		this.board = VariantRules.GetBoard(fen);
 		this.setFlags(fen);
@@ -61,7 +65,7 @@ class ChessRules
 	{
 		this.INIT_COL_KING = {'w':-1, 'b':-1};
 		this.INIT_COL_ROOK = {'w':[-1,-1], 'b':[-1,-1]};
-		this.kingPos = {'w':[-1,-1], 'b':[-1,-1]}; //respective squares of white and black king
+		this.kingPos = {'w':[-1,-1], 'b':[-1,-1]}; //squares of white and black king
 		const fenParts = fen.split(" ");
 		const position = fenParts[0].split("/");
 		for (let i=0; i<position.length; i++)
@@ -380,7 +384,8 @@ class ChessRules
 	// What are the knight moves from square x,y ?
 	getPotentialKnightMoves(sq)
 	{
-		return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.KNIGHT], "oneStep");
+		return this.getSlideNJumpMoves(
+			sq, VariantRules.steps[VariantRules.KNIGHT], "oneStep");
 	}
 
 	// What are the bishop moves from square x,y ?
@@ -481,7 +486,8 @@ class ChessRules
 
 	canIplay(side, [x,y])
 	{
-		return ((side=='w' && this.moves.length%2==0) || (side=='b' && this.moves.length%2==1))
+		return ((side=='w' && this.moves.length%2==0)
+				|| (side=='b' && this.moves.length%2==1))
 			&& this.getColor(x,y) == side;
 	}
 
@@ -491,7 +497,7 @@ class ChessRules
 		return this.filterValid( this.getPotentialMovesFrom(sq) );
 	}
 
-	// TODO: once a promotion is filtered, the others results are same: useless computations
+	// TODO: promotions (into R,B,N,Q) should be filtered only once
 	filterValid(moves)
 	{
 		if (moves.length == 0)
@@ -510,7 +516,7 @@ class ChessRules
 		{
 			for (let j=0; j<sizeY; j++)
 			{
-				// Next condition ... != oppCol is a little HACK to work with checkered variant
+				// Next condition "!= oppCol" = harmless hack to work with checkered variant
 				if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) != oppCol)
 					Array.prototype.push.apply(potentialMoves, this.getPotentialMovesFrom([i,j]));
 			}
@@ -722,8 +728,24 @@ class ChessRules
 			this.kingPos[c] = [move.start.x, move.start.y];
 	}
 
+	// Store a hash of the position + flags + turn after a move is played
+	// (for repetitions detection)
+	addHashState()
+	{
+		const strToHash = this.getFen() + " " + this.turn;
+		const hash = hex_md5(strToHash);
+		if (!this.hashStates[hash])
+			this.hashStates[hash] = 1;
+		else
+			this.hashStates[hash]++;
+	}
+
 	play(move, ingame)
 	{
+		// DEBUG:
+//		if (!this.states) this.states = [];
+//		if (!ingame) this.states.push(JSON.stringify(this.board));
+
 		if (!!ingame)
 			move.notation = [this.getNotation(move), this.getLongNotation(move)];
 
@@ -732,6 +754,9 @@ class ChessRules
 		this.moves.push(move);
 		this.epSquares.push( this.getEpSquare(move) );
 		VariantRules.PlayOnBoard(this.board, move);
+
+		if (!!ingame)
+			this.addHashState();
 	}
 
 	undo(move)
@@ -741,26 +766,20 @@ class ChessRules
 		this.moves.pop();
 		this.unupdateVariables(move);
 		this.parseFlags(JSON.parse(move.flags));
+
+		// DEBUG:
+//		if (JSON.stringify(this.board) != this.states[this.states.length-1])
+//			debugger;
+//		this.states.pop();
 	}
 
 	//////////////
 	// END OF GAME
 
-	// Basic check for 3 repetitions (in the last moves only)
+	// Check for 3 repetitions (position + flags + turn)
 	checkRepetition()
 	{
-		if (this.moves.length >= 8)
-		{
-			const L = this.moves.length;
-			if (_.isEqual(this.moves[L-1], this.moves[L-5]) &&
-				_.isEqual(this.moves[L-2], this.moves[L-6]) &&
-				_.isEqual(this.moves[L-3], this.moves[L-7]) &&
-				_.isEqual(this.moves[L-4], this.moves[L-8]))
-			{
-				return true;
-			}
-		}
-		return false;
+		return Object.values(this.hashStates).some(elt => { return (elt >= 3); });
 	}
 
 	// Is game over ? And if yes, what is the score ?
@@ -819,7 +838,6 @@ class ChessRules
 	// NOTE: works also for extinction chess because depth is 3...
 	getComputerMove()
 	{
-		this.shouldReturn = false;
 		const maxeval = VariantRules.INFINITY;
 		const color = this.turn;
 		// Some variants may show a bigger moves list to the human (Switching),
@@ -869,8 +887,11 @@ class ChessRules
 				const score = this.checkGameEnd();
 				eval2 = (score=="1/2" ? 0 : (score=="1-0" ? 1 : -1) * maxeval);
 			}
-			if ((color=="w" && eval2 > moves1[i].eval) || (color=="b" && eval2 < moves1[i].eval))
+			if ((color=="w" && eval2 > moves1[i].eval)
+				|| (color=="b" && eval2 < moves1[i].eval))
+			{
 				moves1[i].eval = eval2;
+			}
 			this.undo(moves1[i]);
 		}
 		moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); });
@@ -881,14 +902,17 @@ class ChessRules
 			candidates.push(j);
 		let currentBest = moves1[_.sample(candidates, 1)];
 
+		// From here, depth >= 3: may take a while, so we control time
+		const timeStart = Date.now();
+
 		// Skip depth 3+ if we found a checkmate (or if we are checkmated in 1...)
 		if (VariantRules.SEARCH_DEPTH >= 3
 			&& Math.abs(moves1[0].eval) < VariantRules.THRESHOLD_MATE)
 		{
 			for (let i=0; i<moves1.length; i++)
 			{
-				if (this.shouldReturn)
-					return currentBest; //depth-2, minimum
+				if (Date.now()-timeStart >= 5000) //more than 5 seconds
+					return currentBest; //depth 2 at least
 				this.play(moves1[i]);
 				// 0.1 * oldEval : heuristic to avoid some bad moves (not all...)
 				moves1[i].eval = 0.1*moves1[i].eval +
@@ -978,9 +1002,9 @@ class ChessRules
 	// Setup the initial random (assymetric) position
 	static GenRandInitFen()
 	{
-		let pieces = [new Array(8), new Array(8)];
+		let pieces = { "w": new Array(8), "b": new Array(8) };
 		// Shuffle pieces on first and last rank
-		for (let c = 0; c <= 1; c++)
+		for (let c of ["w","b"])
 		{
 			let positions = _.range(8);
 
@@ -1022,11 +1046,10 @@ class ChessRules
 			pieces[c][knight2Pos] = 'n';
 			pieces[c][rook2Pos] = 'r';
 		}
-		let fen = pieces[0].join("") +
+		return pieces["b"].join("") +
 			"/pppppppp/8/8/8/8/PPPPPPPP/" +
-			pieces[1].join("").toUpperCase() +
+			pieces["w"].join("").toUpperCase() +
 			" 1111"; //add flags
-		return fen;
 	}
 
 	// Return current fen according to pieces+colors state
@@ -1137,7 +1160,8 @@ class ChessRules
 		const d = new Date();
 		const opponent = mode=="human" ? "Anonymous" : "Computer";
 		pgn += '[Variant "' + variant + '"]<br>';
-		pgn += '[Date "' + d.getFullYear() + '-' + (d.getMonth()+1) + '-' + zeroPad(d.getDate()) + '"]<br>';
+		pgn += '[Date "' + d.getFullYear() + '-' + (d.getMonth()+1) +
+			'-' + zeroPad(d.getDate()) + '"]<br>';
 		pgn += '[White "' + (mycolor=='w'?'Myself':opponent) + '"]<br>';
 		pgn += '[Black "' + (mycolor=='b'?'Myself':opponent) + '"]<br>';
 		pgn += '[FenStart "' + fenStart + '"]<br>';