X-Git-Url: https://git.auder.net/?p=vchess.git;a=blobdiff_plain;f=public%2Fjavascripts%2Fvariants%2FSwitching.js;h=cc2febd1e646f64fbdec59e520e9a94fa7ee1243;hp=a7d678791e801f788d846ca77b19ccdf8d27f50c;hb=1221ac47836806efb287b0323b92957d9129c653;hpb=a6abf094c35a26019e47fea21302c4be32ff030b

diff --git a/public/javascripts/variants/Switching.js b/public/javascripts/variants/Switching.js
index a7d67879..cc2febd1 100644
--- a/public/javascripts/variants/Switching.js
+++ b/public/javascripts/variants/Switching.js
@@ -1,10 +1,73 @@
-//https://www.chessvariants.com/diffmove.dir/switching.html
 class SwitchingRules extends ChessRules
 {
-	//TODO:
-	// Move completion: promote switched pawns (as in Magnetic)
+	// Build switch move between squares x1,y1 and x2,y2
+	getSwitchMove_s([x1,y1],[x2,y2])
+	{
 
-	// To every piece potential moves: add switchings
+		const c = this.getColor(x1,y1); //same as color at square 2
+		const p1 = this.getPiece(x1,y1);
+		const p2 = this.getPiece(x2,y2);
+		let move = new Move({
+			appear: [
+				new PiPo({x:x2,y:y2,c:c,p:p1}),
+				new PiPo({x:x1,y:y1,c:c,p:p2})
+			],
+			vanish: [
+				new PiPo({x:x1,y:y1,c:c,p:p1}),
+				new PiPo({x:x2,y:y2,c:c,p:p2})
+			],
+			start: {x:x1,y:y1},
+			end: {x:x2,y:y2}
+		});
+		// Move completion: promote switched pawns (as in Magnetic)
+		const sizeX = VariantRules.size[0];
+		const lastRank = (c == "w" ? 0 : sizeX-1);
+		const V = VariantRules;
+		let moves = [];
+		if (p1==V.PAWN && x2==lastRank) //TODO: also the case p2==V.PAWN and x1==lastRank! see Magnetic chess
+		{
+			move.appear[0].p = V.ROOK;
+			moves.push(move);
+			for (let piece of [V.KNIGHT, V.BISHOP, V.QUEEN])
+			{
+				let cmove = JSON.parse(JSON.stringify(move));
+				cmove.appear[0].p = piece;
+				moves.push(cmove);
+			}
+		}
+		else //other cases
+			moves.push(move);
+		return moves;
+	}
 
-	// Prevent king switching if under check
+	getPotentialMovesFrom([x,y])
+	{
+		let moves = super.getPotentialMovesFrom([x,y]);
+		// Add switches:
+		const V = VariantRules;
+		const color = this.turn;
+		const piece = this.getPiece(x,y);
+		const [sizeX,sizeY] = V.size;
+		const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+		const kp = this.kingPos[color];
+		const oppCol = this.getOppCol(color);
+		for (let step of steps)
+		{
+			let [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)==color && this.getPiece(i,j)!=piece
+				// No switching under check (theoretically non-king pieces could, but not)
+				&& !this.isAttacked(kp, [oppCol]))
+			{
+				let switchMove_s = this.getSwitchMove_s([x,y],[i,j]);
+				if (switchMove_s.length == 1)
+					moves.push(switchMove_s[0]);
+				else //promotion
+					moves = moves.concat(switchMove_s);
+			}
+		}
+		return moves;
+	}
+
+	static get SEARCH_DEPTH() { return 2; } //branching factor is quite high
 }