X-Git-Url: https://git.auder.net/assets/icon_close.svg?a=blobdiff_plain;f=public%2Fjavascripts%2Fbase_rules.js;h=42775dab1553cae4d181eb522f28353cada25f1b;hb=efb20746c30ac26f258f9c5de6dfb70b91980de4;hp=f466624d653ebc5ec50e46036c7c3785ecb4b82d;hpb=a37076f1ac8f4c19d9b34a60cbe89df86b88fa0b;p=vchess.git

diff --git a/public/javascripts/base_rules.js b/public/javascripts/base_rules.js
index f466624d..42775dab 100644
--- a/public/javascripts/base_rules.js
+++ b/public/javascripts/base_rules.js
@@ -284,7 +284,7 @@ class ChessRules
 				i += step[0];
 				j += step[1];
 			}
-			if (i>=0 && i<8 && j>=0 && j<8 && this.canTake([x,y], [i,j]))
+			if (i>=0 && i<sizeX && j>=0 && j<sizeY && this.canTake([x,y], [i,j]))
 				moves.push(this.getBasicMove([x,y], [i,j]));
 		}
 		return moves;
@@ -395,7 +395,8 @@ class ChessRules
 	getCastleMoves([x,y])
 	{
 		const c = this.getColor(x,y);
-		if (x != (c=="w" ? 7 : 0) || y != this.INIT_COL_KING[c])
+		const [sizeX,sizeY] = VariantRules.size;
+		if (x != (c=="w" ? sizeX-1 : 0) || y != this.INIT_COL_KING[c])
 			return []; //x isn't first rank, or king has moved (shortcut)
 
 		const V = VariantRules;
@@ -404,7 +405,7 @@ class ChessRules
 		const oppCol = this.getOppCol(c);
 		let moves = [];
 		let i = 0;
-		const finalSquares = [ [2,3], [6,5] ]; //king, then rook
+		const finalSquares = [ [2,3], [sizeY-2,sizeY-3] ]; //king, then rook
 		castlingCheck:
 		for (let castleSide=0; castleSide < 2; castleSide++) //large, then small
 		{
@@ -489,8 +490,8 @@ class ChessRules
 	{
 		const color = this.turn;
 		const oppCol = this.getOppCol(color);
-		var potentialMoves = [];
-		let [sizeX,sizeY] = VariantRules.size;
+		let potentialMoves = [];
+		const [sizeX,sizeY] = VariantRules.size;
 		for (var i=0; i<sizeX; i++)
 		{
 			for (var j=0; j<sizeY; j++)
@@ -510,7 +511,7 @@ class ChessRules
 	{
 		const color = this.turn;
 		const oppCol = this.getOppCol(color);
-		let [sizeX,sizeY] = VariantRules.size;
+		const [sizeX,sizeY] = VariantRules.size;
 		for (let i=0; i<sizeX; i++)
 		{
 			for (let j=0; j<sizeY; j++)
@@ -546,14 +547,15 @@ class ChessRules
 	// Is square x,y attacked by pawns of color c ?
 	isAttackedByPawn([x,y], colors)
 	{
+		const [sizeX,sizeY] = VariantRules.size;
 		for (let c of colors)
 		{
 			let pawnShift = (c=="w" ? 1 : -1);
-			if (x+pawnShift>=0 && x+pawnShift<8)
+			if (x+pawnShift>=0 && x+pawnShift<sizeX)
 			{
 				for (let i of [-1,1])
 				{
-					if (y+i>=0 && y+i<8 && this.getPiece(x+pawnShift,y+i)==VariantRules.PAWN
+					if (y+i>=0 && y+i<sizeY && this.getPiece(x+pawnShift,y+i)==VariantRules.PAWN
 						&& this.getColor(x+pawnShift,y+i)==c)
 					{
 						return true;
@@ -604,16 +606,18 @@ class ChessRules
 	// Generic method for non-pawn pieces ("sliding or jumping"): is x,y attacked by piece != color ?
 	isAttackedBySlideNJump([x,y], colors, piece, steps, oneStep)
 	{
+		const [sizeX,sizeY] = VariantRules.size;
 		for (let step of steps)
 		{
 			let rx = x+step[0], ry = y+step[1];
-			while (rx>=0 && rx<8 && ry>=0 && ry<8 && this.board[rx][ry] == VariantRules.EMPTY
-				&& !oneStep)
+			while (rx>=0 && rx<sizeX && ry>=0 && ry<sizeY
+				&& this.board[rx][ry] == VariantRules.EMPTY && !oneStep)
 			{
 				rx += step[0];
 				ry += step[1];
 			}
-			if (rx>=0 && rx<8 && ry>=0 && ry<8 && this.board[rx][ry] != VariantRules.EMPTY
+			if (rx>=0 && rx<sizeX && ry>=0 && ry<sizeY
+				&& this.board[rx][ry] != VariantRules.EMPTY
 				&& this.getPiece(rx,ry) == piece && colors.includes(this.getColor(rx,ry)))
 			{
 				return true;
@@ -666,7 +670,8 @@ class ChessRules
 	{
 		const piece = this.getPiece(move.start.x,move.start.y);
 		const c = this.getColor(move.start.x,move.start.y);
-		const firstRank = (c == "w" ? 7 : 0);
+		const [sizeX,sizeY] = VariantRules.size;
+		const firstRank = (c == "w" ? sizeX-1 : 0);
 
 		// Update king position + flags
 		if (piece == VariantRules.KING && move.appear.length > 0)
@@ -677,7 +682,7 @@ class ChessRules
 			return;
 		}
 		const oppCol = this.getOppCol(c);
-		const oppFirstRank = 7 - firstRank;
+		const oppFirstRank = (sizeX-1) - firstRank;
 		if (move.start.x == firstRank //our rook moves?
 			&& this.INIT_COL_ROOK[c].includes(move.start.y))
 		{
@@ -798,9 +803,14 @@ class ChessRules
 		return VariantRules.INFINITY;
 	}
 
+	static get SEARCH_DEPTH() {
+		return 3; //2 for high branching factor, 4 for small (Loser chess)
+	}
+
 	// Assumption: at least one legal move
 	getComputerMove(moves1) //moves1 might be precomputed (Magnetic chess)
 	{
+		this.shouldReturn = false;
 		const maxeval = VariantRules.INFINITY;
 		const color = this.turn;
 		if (!moves1)
@@ -832,21 +842,32 @@ class ChessRules
 		}
 		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);
+		let currentBest = moves1[_.sample(candidates, 1)];
+
 		// Skip depth 3 if we found a checkmate (or if we are checkmated in 1...)
-		if (Math.abs(moves1[0].eval) < VariantRules.THRESHOLD_MATE)
+		if (VariantRules.SEARCH_DEPTH >= 3
+			&& Math.abs(moves1[0].eval) < VariantRules.THRESHOLD_MATE)
 		{
 			// TODO: show current analyzed move for depth 3, allow stopping eval (return moves1[0])
 			for (let i=0; i<moves1.length; i++)
 			{
+				if (this.shouldReturn)
+					return currentBest; //depth-2, minimum
 				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);
+				moves1[i].eval = 0.1*moves1[i].eval +
+					this.alphabeta(VariantRules.SEARCH_DEPTH-1, -maxeval, maxeval);
 				this.undo(moves1[i]);
 			}
 			moves1.sort( (a,b) => { return (color=="w" ? 1 : -1) * (b.eval - a.eval); });
 		}
+		else
+			return currentBest;
 
-		let candidates = [0]; //indices of candidates moves
+		candidates = [0];
 		for (let j=1; j<moves1.length && moves1[j].eval == moves1[0].eval; j++)
 			candidates.push(j);
 //		console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; }));