X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=public%2Fjavascripts%2Fbase_rules.js;h=26c744777c1b4a4b77f311363e372ce2dd63a3bb;hb=3c09dc498791ac478679bf2f42f441342c4fa22c;hp=f466624d653ebc5ec50e46036c7c3785ecb4b82d;hpb=a37076f1ac8f4c19d9b34a60cbe89df86b88fa0b;p=vchess.git

diff --git a/public/javascripts/base_rules.js b/public/javascripts/base_rules.js
index f466624d..26c74477 100644
--- a/public/javascripts/base_rules.js
+++ b/public/javascripts/base_rules.js
@@ -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++)
@@ -666,7 +667,8 @@ 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 +679,7 @@ 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 +800,14 @@ 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 +839,32 @@ 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]; }));