X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=public%2Fjavascripts%2Fvariants%2FUltima.js;h=d5b9f88435d6173204e14ed34669e27a0a2d7177;hb=f4fd6580a227a352f6e0e95870954bc2fa2ce97f;hp=d6676436a24f21641ae57783ebd656a4bad85fff;hpb=a3c86ec9b60326a8ae3d8f237493fb09627aed95;p=vchess.git

diff --git a/public/javascripts/variants/Ultima.js b/public/javascripts/variants/Ultima.js
index d6676436..d5b9f884 100644
--- a/public/javascripts/variants/Ultima.js
+++ b/public/javascripts/variants/Ultima.js
@@ -50,16 +50,16 @@ 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?
-		// In this case add potential suicide as a move "taking the immobilizer"
 		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]];
@@ -67,18 +67,33 @@ class UltimaRules extends ChessRules
 				&& this.getColor(i,j) == oppCol)
 			{
 				const oppPiece = this.getPiece(i,j);
-				if (oppPiece == V.IMMOBILIZER
-					|| (oppPiece == V.BISHOP && piece == V.IMMOBILIZER))
+				if (oppPiece == V.BISHOP && piece == V.IMMOBILIZER)
+					return true;
+				if (oppPiece == V.IMMOBILIZER && ![V.BISHOP,V.IMMOBILIZER].includes(piece))
 				{
-					return [ new Move({
-						appear: [],
-						vanish: [new PiPo({x:x,y:y,p:piece,c:color})],
-						start: {x:x,y:y},
-						end: {x:i,y:j}
-					}) ];
+					// 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 ([V.BISHOP,V.IMMOBILIZER].includes(this.getPiece(i2,j2)))
+								return false;
+						}
+					}
+					return true; //immobilizer isn't neutralized
 				}
 			}
 		}
+		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:
@@ -276,11 +291,11 @@ class UltimaRules extends ChessRules
 		return super.getPotentialQueenMoves(sq).concat(this.getKnightCaptures(sq));
 	}
 
-	getPotentialBishopMoves(sq)
+	getPotentialBishopMoves([x,y])
 	{
-		let moves = super.getPotentialQueenMoves(sq)
-			.concat(this.getKnightCaptures(sq,"asChameleon"));
-		// NOTE: no "addKingCaptures" because the king isn't captured
+		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");
@@ -369,42 +384,165 @@ class UltimaRules extends ChessRules
 
 	isAttackedByPawn([x,y], colors)
 	{
-		// Square (x,y) must be surrounded by two enemy pieces,
-		// and one of them at least should be a pawn
+		// 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],[1,1],[-1,1] ];
+		const steps = VariantRules.steps[VariantRules.ROOK]
+			.concat(VariantRules.steps[VariantRules.BISHOP]);
+		const [sizeX,sizeY] = VariantRules.size;
+		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 (i1>=0 && i1<sizeX && i2>=0 && i2<sizeX
+				&& j1>=0 && j1<sizeY && j2>=0 && j2<sizeY)
+			{
+				if ((this.board[i1][j1]!=VariantRules.EMPTY
+					&& colors.includes(this.getColor(i1,j1))
+					&& this.board[i2][j2]==VariantRules.EMPTY)
+						||
+					(this.board[i2][j2]!=VariantRules.EMPTY
+					&& colors.includes(this.getColor(i2,j2))
+					&& this.board[i1][j1]==VariantRules.EMPTY))
+				{
+					// Search a movable enemy pawn landing on the empty square
+					for (let step of steps)
+					{
+						let [ii,jj] = (this.board[i1][j1]==VariantRules.EMPTY ? [i1,j1] : [i2,j2]);
+						let [i3,j3] = [ii+step[0],jj+step[1]];
+						while (i3>=0 && i3<sizeX && j3>=0 && j3<sizeY
+							&& this.board[i3][j3]==VariantRules.EMPTY)
+						{
+							i3 += step[0];
+							j3 += step[1];
+						}
+						if (i3>=0 && i3<sizeX && j3>=0 && j3<sizeY
+							&& this.getPiece(i3,j3) == VariantRules.PAWN
+							&& !this.isImmobilized([i3,j3]))
+						{
+							return true;
+						}
+					}
+				}
+			}
+		}
 		return false;
 	}
 
-	isAttackedByRook(sq, colors)
+	isAttackedByRook([x,y], colors)
 	{
-		// Enemy king must be on same file and a rook on same row (or reverse)
+		// King must be on same column or row,
+		// and a rook should be able to reach a capturing square
+		const [sizeX,sizeY] = VariantRules.size;
+		// 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<sizeX; i++)
+			{
+				for (let j=0; j<sizeY; j++)
+				{
+					if (this.board[i][j] != VariantRules.EMPTY
+						&& this.getPiece(i,j) == VariantRules.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;
 	}
 
-	isAttackedByKnight(sq, colors)
+	isAttackedByKnight([x,y], colors)
 	{
 		// Square (x,y) must be on same line as a knight,
 		// and there must be empty square(s) behind.
+		const V = VariantRules;
+		const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+		const [sizeX,sizeY] = V.size;
+		outerLoop:
+		for (let step of steps)
+		{
+			const [i0,j0] = [x+step[0],y+step[1]];
+			if (i0>=0 && i0<sizeX && j0>=0 && j0<sizeY && this.board[i0][j0] == V.EMPTY)
+			{
+				// Try in opposite direction:
+				let [i,j] = [x-step[0],y-step[1]];
+				while (i>=0 && i<sizeX && j>=0 && j<sizeY && this.board[i][j] == V.EMPTY)
+				{
+					i -= step[0];
+					j -= step[1];
+				}
+				if (i>=0 && i<sizeX && j>=0 && j<sizeY && colors.includes(this.getColor(i,j))
+					&& this.getPiece(i,j) == V.KNIGHT)
+				{
+					if (!this.isImmobilized([i,j]))
+						return true;
+				}
+			}
+		}
 		return false;
 	}
 
-	isAttackedByBishop(sq, colors)
+	isAttackedByBishop([x,y], colors)
 	{
-		// switch on piece nature on square sq: a chameleon attack as this piece
-		// ==> call the appropriate isAttackedBy... (exception of immobilizers)
-		// Other exception: a chameleon cannot attack a chameleon (seemingly...)
+		// 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 V = VariantRules;
+		const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+		const [sizeX,sizeY] = V.size;
+		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
+				&& colors.includes(this.getColor(i,j)) && this.getPiece(i,j) == V.BISHOP)
+			{
+				return true; //bishops are never immobilized
+			}
+		}
 		return false;
 	}
 
-	isAttackedByQueen(sq, colors)
+	isAttackedByQueen([x,y], colors)
 	{
 		// 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 V = VariantRules;
+		const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+		const [sizeX,sizeY] = V.size;
+		for (let step of adjacentSteps)
+		{
+			const sq2 = [x+2*step[0],y+2*step[1]];
+			if (sq2[0]>=0 && sq2[0]<sizeX && sq2[1]>=0 && sq2[1]<sizeY
+				&& this.board[sq2[0]][sq2[1]] == V.EMPTY)
+			{
+				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))
+				{
+					return true;
+				}
+			}
+		}
 		return false;
 	}
 
 	updateVariables(move)
 	{
-		// Just update king position
+		// 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)
@@ -414,12 +552,6 @@ class UltimaRules extends ChessRules
 		}
 	}
 
-	checkGameEnd()
-	{
-		// No valid move: game is lost (stalemate is a win)
-		return this.turn == "w" ? "0-1" : "1-0";
-	}
-
 	static get VALUES() { //TODO: totally experimental!
 		return {
 			'p': 1,
@@ -491,15 +623,4 @@ class UltimaRules extends ChessRules
 	{
 		return "0000"; //TODO: or "-" ?
 	}
-
-	getNotation(move)
-	{
-		if (move.appear.length == 0)
-		{
-			const startSquare =
-				String.fromCharCode(97 + move.start.y) + (VariantRules.size[0]-move.start.x);
-			return "^" + startSquare; //suicide
-		}
-		return super.getNotation(move);
-	}
 }