X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=public%2Fjavascripts%2Fbase_rules.js;h=f466624d653ebc5ec50e46036c7c3785ecb4b82d;hb=a37076f1ac8f4c19d9b34a60cbe89df86b88fa0b;hp=d63806752f726e2f686b23e7ea2516f293418cd5;hpb=5bfb09560aa346d132e829a7c63558407bcc8091;p=vchess.git

diff --git a/public/javascripts/base_rules.js b/public/javascripts/base_rules.js
index d6380675..f466624d 100644
--- a/public/javascripts/base_rules.js
+++ b/public/javascripts/base_rules.js
@@ -171,7 +171,6 @@ class ChessRules
 			'r': [ [-1,0],[1,0],[0,-1],[0,1] ],
 			'n': [ [-1,-2],[-1,2],[1,-2],[1,2],[-2,-1],[-2,1],[2,-1],[2,1] ],
 			'b': [ [-1,-1],[-1,1],[1,-1],[1,1] ],
-			'q': [ [-1,0],[1,0],[0,-1],[0,1],[-1,-1],[-1,1],[1,-1],[1,1] ]
 		};
 	}
 
@@ -379,14 +378,17 @@ class ChessRules
 	// What are the queen moves from square x,y ?
 	getPotentialQueenMoves(sq)
 	{
-		return this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.QUEEN]);
+		const V = VariantRules;
+		return this.getSlideNJumpMoves(sq, V.steps[V.ROOK].concat(V.steps[V.BISHOP]));
 	}
 
 	// What are the king moves from square x,y ?
 	getPotentialKingMoves(sq)
 	{
+		const V = VariantRules;
 		// Initialize with normal moves
-		let moves = this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.QUEEN], "oneStep");
+		let moves = this.getSlideNJumpMoves(sq,
+			V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
 		return moves.concat(this.getCastleMoves(sq));
 	}
 
@@ -479,8 +481,7 @@ class ChessRules
 	{
 		if (moves.length == 0)
 			return [];
-		let color = this.turn;
-		return moves.filter(m => { return !this.underCheck(m, color); });
+		return moves.filter(m => { return !this.underCheck(m); });
 	}
 
 	// Search for all valid moves considering current turn (for engine and game end)
@@ -503,25 +504,25 @@ class ChessRules
 		// No: if happen on last 1/2 move, could lead to forbidden moves, wrong evals
 		return this.filterValid(potentialMoves);
 	}
-	
+
 	// Stop at the first move found
 	atLeastOneMove()
 	{
 		const color = this.turn;
 		const oppCol = this.getOppCol(color);
 		let [sizeX,sizeY] = VariantRules.size;
-		for (var i=0; i<sizeX; i++)
+		for (let i=0; i<sizeX; i++)
 		{
-			for (var j=0; j<sizeY; j++)
+			for (let j=0; j<sizeY; j++)
 			{
 				if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) != oppCol)
 				{
 					const moves = this.getPotentialMovesFrom([i,j]);
 					if (moves.length > 0)
 					{
-						for (let i=0; i<moves.length; i++)
+						for (let k=0; k<moves.length; k++)
 						{
-							if (this.filterValid([moves[i]]).length > 0)
+							if (this.filterValid([moves[k]]).length > 0)
 								return true;
 						}
 					}
@@ -587,15 +588,17 @@ class ChessRules
 	// Is square x,y attacked by queens of color c ?
 	isAttackedByQueen(sq, colors)
 	{
-		return this.isAttackedBySlideNJump(sq, colors,
-			VariantRules.QUEEN, VariantRules.steps[VariantRules.QUEEN]);
+		const V = VariantRules;
+		return this.isAttackedBySlideNJump(sq, colors, V.QUEEN,
+			V.steps[V.ROOK].concat(V.steps[V.BISHOP]));
 	}
 
 	// Is square x,y attacked by king of color c ?
 	isAttackedByKing(sq, colors)
 	{
-		return this.isAttackedBySlideNJump(sq, colors,
-			VariantRules.KING, VariantRules.steps[VariantRules.QUEEN], "oneStep");
+		const V = VariantRules;
+		return this.isAttackedBySlideNJump(sq, colors, V.KING,
+			V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
 	}
 
 	// Generic method for non-pawn pieces ("sliding or jumping"): is x,y attacked by piece != color ?
@@ -699,6 +702,10 @@ class ChessRules
 
 	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);
 
@@ -716,6 +723,11 @@ class ChessRules
 		this.moves.pop();
 		this.unupdateVariables(move);
 		this.parseFlags(JSON.parse(move.flags));
+
+		// DEBUG:
+//		let state = this.states.pop();
+//		if (JSON.stringify(this.board) != state)
+//			debugger;
 	}
 
 	//////////////
@@ -777,18 +789,28 @@ class ChessRules
 		};
 	}
 
+	static get INFINITY() {
+		return 9999; //"checkmate" (unreachable eval)
+	}
+
+	static get THRESHOLD_MATE() {
+		// At this value or above, the game is over
+		return VariantRules.INFINITY;
+	}
+
 	// Assumption: at least one legal move
-	getComputerMove()
+	getComputerMove(moves1) //moves1 might be precomputed (Magnetic chess)
 	{
+		const maxeval = VariantRules.INFINITY;
 		const color = this.turn;
+		if (!moves1)
+			moves1 = this.getAllValidMoves();
 
 		// Rank moves using a min-max at depth 2
-		let moves1 = this.getAllValidMoves();
-
 		for (let i=0; i<moves1.length; i++)
 		{
-			moves1[i].eval = (color=="w" ? -1 : 1) * 1000; //very low, I'm checkmated
-			let eval2 = (color=="w" ? 1 : -1) * 1000; //initialized with very high (checkmate) value
+			moves1[i].eval = (color=="w" ? -1 : 1) * maxeval; //very low, I'm checkmated
+			let eval2 = (color=="w" ? 1 : -1) * maxeval; //initialized with checkmate value
 			this.play(moves1[i]);
 			// Second half-move:
 			let moves2 = this.getAllValidMoves();
@@ -810,39 +832,43 @@ class ChessRules
 		}
 		moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); });
 
-		// TODO: show current analyzed move for depth 3, allow stopping eval (return moves1[0])
-		for (let i=0; i<moves1.length; i++)
+		// Skip depth 3 if we found a checkmate (or if we are checkmated in 1...)
+		if (Math.abs(moves1[0].eval) < VariantRules.THRESHOLD_MATE)
 		{
-			this.play(moves1[i]);
-			// 0.1 * oldEval : heuristic to avoid some bad moves (not all...)
-			moves1[i].eval = 0.1*moves1[i].eval + this.alphabeta(2, -1000, 1000);
-			this.undo(moves1[i]);
+			// TODO: show current analyzed move for depth 3, allow stopping eval (return moves1[0])
+			for (let i=0; i<moves1.length; i++)
+			{
+				this.play(moves1[i]);
+				// 0.1 * oldEval : heuristic to avoid some bad moves (not all...)
+				moves1[i].eval = 0.1*moves1[i].eval + this.alphabeta(2, -maxeval, maxeval);
+				this.undo(moves1[i]);
+			}
+			moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); });
 		}
-		moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); });
 
 		let candidates = [0]; //indices of candidates moves
 		for (let j=1; j<moves1.length && moves1[j].eval == moves1[0].eval; j++)
 			candidates.push(j);
-
-		//console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; }));
+//		console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; }));
 		return moves1[_.sample(candidates, 1)];
 	}
 
 	alphabeta(depth, alpha, beta)
   {
+		const maxeval = VariantRules.INFINITY;
 		const color = this.turn;
 		if (!this.atLeastOneMove())
 		{
 			switch (this.checkGameEnd())
 			{
 				case "1/2": return 0;
-				default: return color=="w" ? -1000 : 1000;
+				default: return color=="w" ? -maxeval : maxeval;
 			}
 		}
 		if (depth == 0)
       return this.evalPosition();
 		const moves = this.getAllValidMoves();
-    let v = color=="w" ? -1000 : 1000;
+    let v = color=="w" ? -maxeval : maxeval;
 		if (color == "w")
 		{
 			for (let i=0; i<moves.length; i++)
@@ -1011,10 +1037,10 @@ class ChessRules
 		}
 
 		// Translate final square
-		let finalSquare =
+		const finalSquare =
 			String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x);
 
-		let piece = this.getPiece(move.start.x, move.start.y);
+		const piece = this.getPiece(move.start.x, move.start.y);
 		if (piece == VariantRules.PAWN)
 		{
 			// Pawn move
@@ -1022,7 +1048,7 @@ class ChessRules
 			if (move.vanish.length > move.appear.length)
 			{
 				// Capture
-				let startColumn = String.fromCharCode(97 + move.start.y);
+				const startColumn = String.fromCharCode(97 + move.start.y);
 				notation = startColumn + "x" + finalSquare;
 			}
 			else //no capture
@@ -1035,7 +1061,8 @@ class ChessRules
 		else
 		{
 			// Piece movement
-			return piece.toUpperCase() + (move.vanish.length > 1 ? "x" : "") + finalSquare;
+			return piece.toUpperCase() +
+				(move.vanish.length > move.appear.length ? "x" : "") + finalSquare;
 		}
 	}
 
@@ -1046,6 +1073,7 @@ class ChessRules
 		pgn += '[Site "vchess.club"]<br>';
 		const d = new Date();
 		const opponent = mode=="human" ? "Anonymous" : "Computer";
+		pgn += '[Variant "' + variant + '"]<br>';
 		pgn += '[Date "' + d.getFullYear() + '-' + (d.getMonth()+1) + '-' + d.getDate() + '"]<br>';
 		pgn += '[White "' + (mycolor=='w'?'Myself':opponent) + '"]<br>';
 		pgn += '[Black "' + (mycolor=='b'?'Myself':opponent) + '"]<br>';