X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=public%2Fjavascripts%2Fvariants%2FUltima.js;h=d6fecb70d49d5c74eb7f1509ee7358190176393c;hb=7931e479adf93c87771ded1892a0873af72ae46d;hp=c98822dcbf0e85aa68889faf0f4c338194dd79ef;hpb=9d218497ab97bc0e94ec4c1f0a40cf02df3ea0d4;p=vchess.git

diff --git a/public/javascripts/variants/Ultima.js b/public/javascripts/variants/Ultima.js
index c98822dc..d6fecb70 100644
--- a/public/javascripts/variants/Ultima.js
+++ b/public/javascripts/variants/Ultima.js
@@ -7,6 +7,15 @@ class UltimaRules extends ChessRules
 		return b; //usual piece
 	}
 
+	static get PIECES() {
+		return ChessRules.PIECES.concat([V.IMMOBILIZER]);
+	}
+
+	static IsGoodFlags(flags)
+	{
+		return true; //anything is good: no flags
+	}
+
 	initVariables(fen)
 	{
 		this.kingPos = {'w':[-1,-1], 'b':[-1,-1]};
@@ -50,46 +59,54 @@ class UltimaRules extends ChessRules
 	//  - a "bishop" is a chameleon, capturing as its prey
 	//  - a "queen" is a withdrawer, capturing by moving away from pieces
 
-	getPotentialMovesFrom([x,y])
+	// Is piece on square (x,y) immobilized?
+	isImmobilized([x,y])
 	{
-		// Pre-check: is thing on this square immobilized?
 		const piece = this.getPiece(x,y);
 		const color = this.getColor(x,y);
 		const oppCol = this.getOppCol(color);
-		const V = VariantRules;
 		const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
-		const [sizeX,sizeY] = V.size;
 		outerLoop:
 		for (let step of adjacentSteps)
 		{
 			const [i,j] = [x+step[0],y+step[1]];
-			if (i>=0 && i<sizeX && j>=0 && j<sizeY && this.board[i][j] != V.EMPTY
+			if (V.OnBoard(i,j) && this.board[i][j] != V.EMPTY
 				&& this.getColor(i,j) == oppCol)
 			{
 				const oppPiece = this.getPiece(i,j);
-				if (oppPiece == V.BISHOP && piece == V.IMMOBILIZER)
-					return [];
-				if (oppPiece == V.IMMOBILIZER && ![V.BISHOP,V.IMMOBILIZER].includes(piece))
+				if (oppPiece == V.IMMOBILIZER)
 				{
 					// Moving is impossible only if this immobilizer is not neutralized
 					for (let step2 of adjacentSteps)
 					{
 						const [i2,j2] = [i+step2[0],j+step2[1]];
-						if (i2>=0 && i2<sizeX && j2>=0 && j2<sizeY
-							&& this.board[i2][j2] != V.EMPTY && this.getColor(i2,j2) == color)
+						if (i2 == x && j2 == y)
+							continue; //skip initial piece!
+						if (V.OnBoard(i2,j2) && this.board[i2][j2] != V.EMPTY
+							&& this.getColor(i2,j2) == color)
 						{
-							const friendlyPiece = this.getPiece(i2,j2);
-							if ([V.BISHOP,V.IMMOBILIZER].includes(friendlyPiece))
-								break outerLoop;
+							if ([V.BISHOP,V.IMMOBILIZER].includes(this.getPiece(i2,j2)))
+								return false;
 						}
 					}
-					return []; //immobilizer isn't neutralized
+					return true; //immobilizer isn't neutralized
 				}
+				// Chameleons can't be immobilized twice, because there is only one immobilizer
+				if (oppPiece == V.BISHOP && piece == V.IMMOBILIZER)
+					return true;
 			}
 		}
+		return false;
+	}
+
+	getPotentialMovesFrom([x,y])
+	{
+		// Pre-check: is thing on this square immobilized?
+		if (this.isImmobilized([x,y]))
+			return [];
 		switch (this.getPiece(x,y))
 		{
-			case VariantRules.IMMOBILIZER:
+			case V.IMMOBILIZER:
 				return this.getPotentialImmobilizerMoves([x,y]);
 			default:
 				return super.getPotentialMovesFrom([x,y]);
@@ -101,14 +118,12 @@ class UltimaRules extends ChessRules
 		const color = this.getColor(x,y);
 		const piece = this.getPiece(x,y);
 		let moves = [];
-		const [sizeX,sizeY] = VariantRules.size;
 		outerLoop:
 		for (let step of steps)
 		{
 			let i = x + step[0];
 			let j = y + step[1];
-			while (i>=0 && i<sizeX && j>=0 && j<sizeY
-				&& this.board[i][j] == VariantRules.EMPTY)
+			while (V.OnBoard(i,j) && this.board[i][j] == V.EMPTY)
 			{
 				moves.push(this.getBasicMove([x,y], [i,j]));
 				if (oneStep !== undefined)
@@ -117,11 +132,8 @@ class UltimaRules extends ChessRules
 				j += step[1];
 			}
 			// Only king can take on occupied square:
-			if (piece==VariantRules.KING && i>=0 && i<sizeX && j>=0
-				&& j<sizeY && this.canTake([x,y], [i,j]))
-			{
+			if (piece==V.KING && V.OnBoard(i,j) && this.canTake([x,y], [i,j]))
 				moves.push(this.getBasicMove([x,y], [i,j]));
-			}
 		}
 		return moves;
 	}
@@ -129,8 +141,7 @@ class UltimaRules extends ChessRules
 	// Modify capturing moves among listed pawn moves
 	addPawnCaptures(moves, byChameleon)
 	{
-		const steps = VariantRules.steps[VariantRules.ROOK];
-		const [sizeX,sizeY] = VariantRules.size;
+		const steps = V.steps[V.ROOK];
 		const color = this.turn;
 		const oppCol = this.getOppCol(color);
 		moves.forEach(m => {
@@ -140,17 +151,16 @@ class UltimaRules extends ChessRules
 			for (let step of steps)
 			{
 				const sq2 = [m.end.x+2*step[0],m.end.y+2*step[1]];
-				if (sq2[0]>=0 && sq2[0]<sizeX && sq2[1]>=0 && sq2[1]<sizeY
-					&& this.board[sq2[0]][sq2[1]] != VariantRules.EMPTY
+				if (V.OnBoard(sq2[0],sq2[1]) && this.board[sq2[0]][sq2[1]] != V.EMPTY
 					&& this.getColor(sq2[0],sq2[1]) == color)
 				{
 					// Potential capture
 					const sq1 = [m.end.x+step[0],m.end.y+step[1]];
-					if (this.board[sq1[0]][sq1[1]] != VariantRules.EMPTY
+					if (this.board[sq1[0]][sq1[1]] != V.EMPTY
 						&& this.getColor(sq1[0],sq1[1]) == oppCol)
 					{
 						const piece1 = this.getPiece(sq1[0],sq1[1]);
-						if (!byChameleon || piece1 == VariantRules.PAWN)
+						if (!byChameleon || piece1 == V.PAWN)
 						{
 							m.vanish.push(new PiPo({
 								x:sq1[0],
@@ -182,14 +192,14 @@ class UltimaRules extends ChessRules
 			// Check piece-king rectangle (if any) corners for enemy pieces
 			if (m.end.x == kp[0] || m.end.y == kp[1])
 				return; //"flat rectangle"
-			const corner1 = [Math.max(m.end.x,kp[0]), Math.min(m.end.y,kp[1])];
-			const corner2 = [Math.min(m.end.x,kp[0]), Math.max(m.end.y,kp[1])];
+			const corner1 = [m.end.x, kp[1]];
+			const corner2 = [kp[0], m.end.y];
 			for (let [i,j] of [corner1,corner2])
 			{
-				if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) == oppCol)
+				if (this.board[i][j] != V.EMPTY && this.getColor(i,j) == oppCol)
 				{
 					const piece = this.getPiece(i,j);
-					if (!byChameleon || piece == VariantRules.ROOK)
+					if (!byChameleon || piece == V.ROOK)
 					{
 						m.vanish.push( new PiPo({
 							x:i,
@@ -215,9 +225,7 @@ class UltimaRules extends ChessRules
 	getKnightCaptures(startSquare, byChameleon)
 	{
 		// Look in every direction for captures
-		const V = VariantRules;
 		const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
-		const [sizeX,sizeY] = V.size;
 		const color = this.turn;
 		const oppCol = this.getOppCol(color);
 		let moves = [];
@@ -227,12 +235,12 @@ class UltimaRules extends ChessRules
 		for (let step of steps)
 		{
 			let [i,j] = [x+step[0], y+step[1]];
-			while (i>=0 && i<sizeX && j>=0 && j<sizeY && this.board[i][j]==V.EMPTY)
+			while (V.OnBoard(i,j) && this.board[i][j]==V.EMPTY)
 			{
 				i += step[0];
 				j += step[1];
 			}
-			if (i<0 || i>=sizeX || j<0 || j>=sizeY || this.getColor(i,j)==color
+			if (!V.OnBoard(i,j) || this.getColor(i,j)==color
 				|| (!!byChameleon && this.getPiece(i,j)!=V.KNIGHT))
 			{
 				continue;
@@ -244,7 +252,7 @@ class UltimaRules extends ChessRules
 			let last = [i,j];
 			let cur = [i+step[0],j+step[1]];
 			let vanished = [ new PiPo({x:x,y:y,c:color,p:piece}) ];
-			while (cur[0]>=0 && cur[0]<sizeX && cur[1]>=0 && cur[1]<sizeY)
+			while (V.OnBoard(cur[0],cur[1]))
 			{
 				if (this.board[last[0]][last[1]] != V.EMPTY)
 				{
@@ -288,18 +296,14 @@ class UltimaRules extends ChessRules
 	{
 		let moves = super.getPotentialQueenMoves([x,y])
 			.concat(this.getKnightCaptures([x,y],"asChameleon"));
+		// No "king capture" because king cannot remain under check
 		this.addPawnCaptures(moves, "asChameleon");
 		this.addRookCaptures(moves, "asChameleon");
 		this.addQueenCaptures(moves, "asChameleon");
-		// Add king capture if it's within range
-		const oppKp = this.kingPos[this.getOppCol(this.turn)];
-		if (Math.abs(x-oppKp[0]) <= 1 && Math.abs(y-oppKp[1]) <= 1)
-			moves.push(this.getBasicMove([x,y],oppKp));
 		// Post-processing: merge similar moves, concatenating vanish arrays
 		let mergedMoves = {};
-		const [sizeX,sizeY] = VariantRules.size;
 		moves.forEach(m => {
-			const key = m.end.x + sizeX * m.end.y;
+			const key = m.end.x + V.size.x * m.end.y;
 			if (!mergedMoves[key])
 				mergedMoves[key] = m;
 			else
@@ -320,16 +324,13 @@ class UltimaRules extends ChessRules
 		if (moves.length == 0)
 			return;
 		const [x,y] = [moves[0].start.x,moves[0].start.y];
-		const V = VariantRules;
 		const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
 		let capturingDirections = [];
 		const color = this.turn;
 		const oppCol = this.getOppCol(color);
-		const [sizeX,sizeY] = V.size;
 		adjacentSteps.forEach(step => {
 			const [i,j] = [x+step[0],y+step[1]];
-			if (i>=0 && i<sizeX && j>=0 && j<sizeY
-				&& this.board[i][j] != V.EMPTY && this.getColor(i,j) == oppCol
+			if (V.OnBoard(i,j) && this.board[i][j] != V.EMPTY && this.getColor(i,j) == oppCol
 				&& (!byChameleon || this.getPiece(i,j) == V.QUEEN))
 			{
 				capturingDirections.push(step);
@@ -371,82 +372,176 @@ class UltimaRules extends ChessRules
 
 	getPotentialKingMoves(sq)
 	{
-		const V = VariantRules;
 		return this.getSlideNJumpMoves(sq,
 			V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
 	}
 
-	atLeastOneMove()
-	{
-		if (this.kingPos[this.turn][0] < 0)
-			return false;
-		return super.atLeastOneMove();
-	}
+	// isAttacked() is OK because the immobilizer doesn't take
 
-	underCheck(move)
+	isAttackedByPawn([x,y], colors)
 	{
-		return false; //there is no check
+		// Square (x,y) must be surroundable by two enemy pieces,
+		// and one of them at least should be a pawn (moving).
+		const dirs = [ [1,0],[0,1] ];
+		const steps = V.steps[V.ROOK];
+		for (let dir of dirs)
+		{
+			const [i1,j1] = [x-dir[0],y-dir[1]]; //"before"
+			const [i2,j2] = [x+dir[0],y+dir[1]]; //"after"
+			if (V.OnBoard(i1,j1) && V.OnBoard(i2,j2))
+			{
+				if ((this.board[i1][j1]!=V.EMPTY && colors.includes(this.getColor(i1,j1))
+					&& this.board[i2][j2]==V.EMPTY)
+						||
+					(this.board[i2][j2]!=V.EMPTY && colors.includes(this.getColor(i2,j2))
+					&& this.board[i1][j1]==V.EMPTY))
+				{
+					// Search a movable enemy pawn landing on the empty square
+					for (let step of steps)
+					{
+						let [ii,jj] = (this.board[i1][j1]==V.EMPTY ? [i1,j1] : [i2,j2]);
+						let [i3,j3] = [ii+step[0],jj+step[1]];
+						while (V.OnBoard(i3,j3) && this.board[i3][j3]==V.EMPTY)
+						{
+							i3 += step[0];
+							j3 += step[1];
+						}
+						if (V.OnBoard(i3,j3) && colors.includes(this.getColor(i3,j3))
+							&& this.getPiece(i3,j3) == V.PAWN && !this.isImmobilized([i3,j3]))
+						{
+							return true;
+						}
+					}
+				}
+			}
+		}
+		return false;
 	}
 
-	getCheckSquares(move)
+	isAttackedByRook([x,y], colors)
 	{
-		const c = this.getOppCol(this.turn); //opponent
-		const saveKingPos = this.kingPos[c]; //king might be taken
-		this.play(move);
-		// The only way to be "under check" is to have lost the king (thus game over)
-		let res = this.kingPos[c][0] < 0
-			? [ JSON.parse(JSON.stringify(saveKingPos)) ]
-			: [ ];
-		this.undo(move);
-		return res;
+		// King must be on same column or row,
+		// and a rook should be able to reach a capturing square
+		// colors contains only one element, giving the oppCol and thus king position
+		const sameRow = (x == this.kingPos[colors[0]][0]);
+		const sameColumn = (y == this.kingPos[colors[0]][1]);
+		if (sameRow || sameColumn)
+		{
+			// Look for the enemy rook (maximum 1)
+			for (let i=0; i<V.size.x; i++)
+			{
+				for (let j=0; j<V.size.y; j++)
+				{
+					if (this.board[i][j] != V.EMPTY && colors.includes(this.getColor(i,j))
+						&& this.getPiece(i,j) == V.ROOK)
+					{
+						if (this.isImmobilized([i,j]))
+							return false; //because only one rook
+						// Can it reach a capturing square?
+						// Easy but quite suboptimal way (TODO): generate all moves (turn is OK)
+						const moves = this.getPotentialMovesFrom([i,j]);
+						for (let move of moves)
+						{
+							if (sameRow && move.end.y == y || sameColumn && move.end.x == x)
+								return true;
+						}
+					}
+				}
+			}
+		}
+		return false;
 	}
 
-	updateVariables(move)
+	isAttackedByKnight([x,y], colors)
 	{
-		// Just update king(s) position(s)
-		const piece = this.getPiece(move.start.x,move.start.y);
-		const c = this.getColor(move.start.x,move.start.y);
-		if (piece == VariantRules.KING && move.appear.length > 0)
+		// Square (x,y) must be on same line as a knight,
+		// and there must be empty square(s) behind.
+		const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+		outerLoop:
+		for (let step of steps)
 		{
-			this.kingPos[c][0] = move.appear[0].x;
-			this.kingPos[c][1] = move.appear[0].y;
+			const [i0,j0] = [x+step[0],y+step[1]];
+			if (V.OnBoard(i0,j0) && this.board[i0][j0] == V.EMPTY)
+			{
+				// Try in opposite direction:
+				let [i,j] = [x-step[0],y-step[1]];
+				while (V.OnBoard(i,j))
+				{
+					while (V.OnBoard(i,j) && this.board[i][j] == V.EMPTY)
+					{
+						i -= step[0];
+						j -= step[1];
+					}
+					if (V.OnBoard(i,j))
+					{
+						if (colors.includes(this.getColor(i,j)))
+						{
+							if (this.getPiece(i,j) == V.KNIGHT && !this.isImmobilized([i,j]))
+								return true;
+							continue outerLoop;
+						}
+						// [else] Our color, could be captured *if there was an empty space*
+						if (this.board[i+step[0]][j+step[1]] != V.EMPTY)
+							continue outerLoop;
+						i -= step[0];
+						j -= step[1];
+					}
+				}
+			}
 		}
-		// Does this move takes opponent's king?
-		const oppCol = this.getOppCol(c);
-		for (let i=1; i<move.vanish.length; i++)
+		return false;
+	}
+
+	isAttackedByBishop([x,y], colors)
+	{
+		// We cheat a little here: since this function is used exclusively for king,
+		// it's enough to check the immediate surrounding of the square.
+		const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+		for (let step of adjacentSteps)
 		{
-			if (move.vanish[i].p == VariantRules.KING)
+			const [i,j] = [x+step[0],y+step[1]];
+			if (V.OnBoard(i,j) && this.board[i][j]!=V.EMPTY
+				&& colors.includes(this.getColor(i,j)) && this.getPiece(i,j) == V.BISHOP)
 			{
-				this.kingPos[oppCol] = [-1,-1];
-				break;
+				return true; //bishops are never immobilized
 			}
 		}
+		return false;
 	}
 
-	unupdateVariables(move)
+	isAttackedByQueen([x,y], colors)
 	{
-		super.unupdateVariables(move);
-		const c = this.getColor(move.start.x,move.start.y);
-		const oppCol = this.getOppCol(c);
-		if (this.kingPos[oppCol][0] < 0)
+		// Square (x,y) must be adjacent to a queen, and the queen must have
+		// some free space in the opposite direction from (x,y)
+		const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+		for (let step of adjacentSteps)
 		{
-			// Last move took opponent's king
-			for (let i=1; i<move.vanish.length; i++)
+			const sq2 = [x+2*step[0],y+2*step[1]];
+			if (V.OnBoard(sq2[0],sq2[1]) && this.board[sq2[0]][sq2[1]] == V.EMPTY)
 			{
-				const psq = move.vanish[i];
-				if (psq.p == 'k')
+				const sq1 = [x+step[0],y+step[1]];
+				if (this.board[sq1[0]][sq1[1]] != V.EMPTY
+					&& colors.includes(this.getColor(sq1[0],sq1[1]))
+					&& this.getPiece(sq1[0],sq1[1]) == V.QUEEN
+					&& !this.isImmobilized(sq1))
 				{
-					this.kingPos[oppCol] = [psq.x, psq.y];
-					break;
+					return true;
 				}
 			}
 		}
+		return false;
 	}
 
-	checkGameEnd()
+	updateVariables(move)
 	{
-		// Stalemate, or our king disappeared
-		return this.turn == "w" ? "0-1" : "1-0";
+		// Just update king(s) position(s)
+		const piece = this.getPiece(move.start.x,move.start.y);
+		const c = this.getColor(move.start.x,move.start.y);
+		if (piece == V.KING && move.appear.length > 0)
+		{
+			this.kingPos[c][0] = move.appear[0].x;
+			this.kingPos[c][1] = move.appear[0].y;
+		}
 	}
 
 	static get VALUES() { //TODO: totally experimental!
@@ -463,10 +558,6 @@ class UltimaRules extends ChessRules
 
 	static get SEARCH_DEPTH() { return 2; } //TODO?
 
-	static get THRESHOLD_MATE() {
-		return 500; //checkmates evals may be slightly below 1000
-	}
-
 	static GenRandInitFen()
 	{
 		let pieces = { "w": new Array(8), "b": new Array(8) };
@@ -524,4 +615,24 @@ class UltimaRules extends ChessRules
 	{
 		return "0000"; //TODO: or "-" ?
 	}
+
+	getNotation(move)
+	{
+		const initialSquare =
+			String.fromCharCode(97 + move.start.y) + (V.size.x-move.start.x);
+		const finalSquare = String.fromCharCode(97 + move.end.y) + (V.size.x-move.end.x);
+		let notation = undefined;
+		if (move.appear[0].p == V.PAWN)
+		{
+			// Pawn: generally ambiguous short notation, so we use full description
+			notation = "P" + initialSquare + finalSquare;
+		}
+		else if (move.appear[0].p == V.KING)
+			notation = "K" + (move.vanish.length>1 ? "x" : "") + finalSquare;
+		else
+			notation = move.appear[0].p.toUpperCase() + finalSquare;
+		if (move.vanish.length > 1 && move.appear[0].p != V.KING)
+			notation += "X"; //capture mark (not describing what is captured...)
+		return notation;
+	}
 }