X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=client%2Fsrc%2Fvariants%2FBaroque.js;h=4ff23a00abd1c3a8944ffed20eb7ac9c997ee772;hb=e50a802531b99829c533f22ecd21e359e7e1e049;hp=ce9e66727be0e995656770bc40b7e78ed1283d83;hpb=656b187886e5187e52fafe44b7dc0fb45ccd9222;p=vchess.git

diff --git a/client/src/variants/Baroque.js b/client/src/variants/Baroque.js
index ce9e6672..4ff23a00 100644
--- a/client/src/variants/Baroque.js
+++ b/client/src/variants/Baroque.js
@@ -1,616 +1,589 @@
-class BaroqueRules extends ChessRules
-{
-	static get HasFlags() { return false; }
-
-	static get HasEnpassant() { return false; }
-
-	static getPpath(b)
-	{
-		if (b[1] == "m") //'m' for Immobilizer (I is too similar to 1)
-			return "Baroque/" + b;
-		return b; //usual piece
-	}
-
-	static get PIECES()
-	{
-		return ChessRules.PIECES.concat([V.IMMOBILIZER]);
-	}
-
-	// No castling, but checks, so keep track of kings
-	setOtherVariables(fen)
-	{
-		this.kingPos = {'w':[-1,-1], 'b':[-1,-1]};
-		const fenParts = fen.split(" ");
-		const position = fenParts[0].split("/");
-		for (let i=0; i<position.length; i++)
-		{
-			let k = 0;
-			for (let j=0; j<position[i].length; j++)
-			{
-				switch (position[i].charAt(j))
-				{
-					case 'k':
-						this.kingPos['b'] = [i,k];
-						break;
-					case 'K':
-						this.kingPos['w'] = [i,k];
-						break;
-					default:
-						let num = parseInt(position[i].charAt(j));
-						if (!isNaN(num))
-							k += (num-1);
-				}
-				k++;
-			}
-		}
-	}
-
-	static get IMMOBILIZER() { return 'm'; }
-	// Although other pieces keep their names here for coding simplicity,
-	// keep in mind that:
-	//  - a "rook" is a coordinator, capturing by coordinating with the king
-	//  - a "knight" is a long-leaper, capturing as in draughts
-	//  - a "bishop" is a chameleon, capturing as its prey
-	//  - a "queen" is a withdrawer, capturing by moving away from pieces
-
-	// Is piece on square (x,y) immobilized?
-	isImmobilized([x,y])
-	{
-		const piece = this.getPiece(x,y);
-		const color = this.getColor(x,y);
-		const oppCol = V.GetOppCol(color);
-		const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
-		outerLoop:
-		for (let step of adjacentSteps)
-		{
-			const [i,j] = [x+step[0],y+step[1]];
-			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.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 == x && j2 == y)
-							continue; //skip initial piece!
-						if (V.OnBoard(i2,j2) && 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
-				}
-				// 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 V.IMMOBILIZER:
-				return this.getPotentialImmobilizerMoves([x,y]);
-			default:
-				return super.getPotentialMovesFrom([x,y]);
-		}
-	}
-
-	getSlideNJumpMoves([x,y], steps, oneStep)
-	{
-		const color = this.getColor(x,y);
-		const piece = this.getPiece(x,y);
-		let moves = [];
-		outerLoop:
-		for (let step of steps)
-		{
-			let i = x + step[0];
-			let j = y + step[1];
-			while (V.OnBoard(i,j) && this.board[i][j] == V.EMPTY)
-			{
-				moves.push(this.getBasicMove([x,y], [i,j]));
-				if (oneStep !== undefined)
-					continue outerLoop;
-				i += step[0];
-				j += step[1];
-			}
-			// Only king can take on occupied square:
-			if (piece==V.KING && V.OnBoard(i,j) && this.canTake([x,y], [i,j]))
-				moves.push(this.getBasicMove([x,y], [i,j]));
-		}
-		return moves;
-	}
-
-	// Modify capturing moves among listed pawn moves
-	addPawnCaptures(moves, byChameleon)
-	{
-		const steps = V.steps[V.ROOK];
-		const color = this.turn;
-		const oppCol = V.GetOppCol(color);
-		moves.forEach(m => {
-			if (!!byChameleon && m.start.x!=m.end.x && m.start.y!=m.end.y)
-				return; //chameleon not moving as pawn
-			// Try capturing in every direction
-			for (let step of steps)
-			{
-				const sq2 = [m.end.x+2*step[0],m.end.y+2*step[1]];
-				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]] != V.EMPTY
-						&& this.getColor(sq1[0],sq1[1]) == oppCol)
-					{
-						const piece1 = this.getPiece(sq1[0],sq1[1]);
-						if (!byChameleon || piece1 == V.PAWN)
-						{
-							m.vanish.push(new PiPo({
-								x:sq1[0],
-								y:sq1[1],
-								c:oppCol,
-								p:piece1
-							}));
-						}
-					}
-				}
-			}
-		});
-	}
-
-	// "Pincer"
-	getPotentialPawnMoves([x,y])
-	{
-		let moves = super.getPotentialRookMoves([x,y]);
-		this.addPawnCaptures(moves);
-		return moves;
-	}
-
-	addRookCaptures(moves, byChameleon)
-	{
-		const color = this.turn;
-		const oppCol = V.GetOppCol(color);
-		const kp = this.kingPos[color];
-		moves.forEach(m => {
-			// 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 = [m.end.x, kp[1]];
-			const corner2 = [kp[0], m.end.y];
-			for (let [i,j] of [corner1,corner2])
-			{
-				if (this.board[i][j] != V.EMPTY && this.getColor(i,j) == oppCol)
-				{
-					const piece = this.getPiece(i,j);
-					if (!byChameleon || piece == V.ROOK)
-					{
-						m.vanish.push( new PiPo({
-							x:i,
-							y:j,
-							p:piece,
-							c:oppCol
-						}) );
-					}
-				}
-			}
-		});
-	}
-
-	// Coordinator
-	getPotentialRookMoves(sq)
-	{
-		let moves = super.getPotentialQueenMoves(sq);
-		this.addRookCaptures(moves);
-		return moves;
-	}
-
-	// Long-leaper
-	getKnightCaptures(startSquare, byChameleon)
-	{
-		// Look in every direction for captures
-		const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
-		const color = this.turn;
-		const oppCol = V.GetOppCol(color);
-		let moves = [];
-		const [x,y] = [startSquare[0],startSquare[1]];
-		const piece = this.getPiece(x,y); //might be a chameleon!
-		outerLoop:
-		for (let step of steps)
-		{
-			let [i,j] = [x+step[0], y+step[1]];
-			while (V.OnBoard(i,j) && this.board[i][j]==V.EMPTY)
-			{
-				i += step[0];
-				j += step[1];
-			}
-			if (!V.OnBoard(i,j) || this.getColor(i,j)==color
-				|| (!!byChameleon && this.getPiece(i,j)!=V.KNIGHT))
-			{
-				continue;
-			}
-			// last(thing), cur(thing) : stop if "cur" is our color, or beyond board limits,
-			// or if "last" isn't empty and cur neither. Otherwise, if cur is empty then
-			// add move until cur square; if cur is occupied then stop if !!byChameleon and
-			// the square not occupied by a leaper.
-			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 (V.OnBoard(cur[0],cur[1]))
-			{
-				if (this.board[last[0]][last[1]] != V.EMPTY)
-				{
-					const oppPiece = this.getPiece(last[0],last[1]);
-					if (!!byChameleon && oppPiece != V.KNIGHT)
-						continue outerLoop;
-					// Something to eat:
-					vanished.push( new PiPo({x:last[0],y:last[1],c:oppCol,p:oppPiece}) );
-				}
-				if (this.board[cur[0]][cur[1]] != V.EMPTY)
-				{
-					if (this.getColor(cur[0],cur[1]) == color
-						|| this.board[last[0]][last[1]] != V.EMPTY) //TODO: redundant test
-					{
-						continue outerLoop;
-					}
-				}
-				else
-				{
-					moves.push(new Move({
-						appear: [ new PiPo({x:cur[0],y:cur[1],c:color,p:piece}) ],
-						vanish: JSON.parse(JSON.stringify(vanished)), //TODO: required?
-						start: {x:x,y:y},
-						end: {x:cur[0],y:cur[1]}
-					}));
-				}
-				last = [last[0]+step[0],last[1]+step[1]];
-				cur = [cur[0]+step[0],cur[1]+step[1]];
-			}
-		}
-		return moves;
-	}
-
-	// Long-leaper
-	getPotentialKnightMoves(sq)
-	{
-		return super.getPotentialQueenMoves(sq).concat(this.getKnightCaptures(sq));
-	}
-
-	getPotentialBishopMoves([x,y])
-	{
-		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");
-		// Post-processing: merge similar moves, concatenating vanish arrays
-		let mergedMoves = {};
-		moves.forEach(m => {
-			const key = m.end.x + V.size.x * m.end.y;
-			if (!mergedMoves[key])
-				mergedMoves[key] = m;
-			else
-			{
-				for (let i=1; i<m.vanish.length; i++)
-					mergedMoves[key].vanish.push(m.vanish[i]);
-			}
-		});
-		// Finally return an array
-		moves = [];
-		Object.keys(mergedMoves).forEach(k => { moves.push(mergedMoves[k]); });
-		return moves;
-	}
-
-	// Withdrawer
-	addQueenCaptures(moves, byChameleon)
-	{
-		if (moves.length == 0)
-			return;
-		const [x,y] = [moves[0].start.x,moves[0].start.y];
-		const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
-		let capturingDirections = [];
-		const color = this.turn;
-		const oppCol = V.GetOppCol(color);
-		adjacentSteps.forEach(step => {
-			const [i,j] = [x+step[0],y+step[1]];
-			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);
-			}
-		});
-		moves.forEach(m => {
-			const step = [
-				m.end.x!=x ? (m.end.x-x)/Math.abs(m.end.x-x) : 0,
-				m.end.y!=y ? (m.end.y-y)/Math.abs(m.end.y-y) : 0
-			];
-			// NOTE: includes() and even _.isEqual() functions fail...
-			// TODO: this test should be done only once per direction
-			if (capturingDirections.some(dir =>
-				{ return (dir[0]==-step[0] && dir[1]==-step[1]); }))
-			{
-				const [i,j] = [x-step[0],y-step[1]];
-				m.vanish.push(new PiPo({
-					x:i,
-					y:j,
-					p:this.getPiece(i,j),
-					c:oppCol
-				}));
-			}
-		});
-	}
-
-	getPotentialQueenMoves(sq)
-	{
-		let moves = super.getPotentialQueenMoves(sq);
-		this.addQueenCaptures(moves);
-		return moves;
-	}
-
-	getPotentialImmobilizerMoves(sq)
-	{
-		// Immobilizer doesn't capture
-		return super.getPotentialQueenMoves(sq);
-	}
-
-	getPotentialKingMoves(sq)
-	{
-		return this.getSlideNJumpMoves(sq,
-			V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
-	}
-
-	// isAttacked() is OK because the immobilizer doesn't take
-
-	isAttackedByPawn([x,y], colors)
-	{
-		// 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;
-	}
-
-	isAttackedByRook([x,y], colors)
-	{
-		// 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;
-	}
-
-	isAttackedByKnight([x,y], colors)
-	{
-		// 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)
-		{
-			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];
-					}
-				}
-			}
-		}
-		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)
-		{
-			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)
-			{
-				return true; //bishops are never immobilized
-			}
-		}
-		return false;
-	}
-
-	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 adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
-		for (let step of adjacentSteps)
-		{
-			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 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;
-	}
-
-	static get VALUES()
-	{
-		// TODO: totally experimental!
-		return {
-			'p': 1,
-			'r': 2,
-			'n': 5,
-			'b': 3,
-			'q': 3,
-			'm': 5,
-			'k': 1000
-		};
-	}
-
-	static get SEARCH_DEPTH() { return 2; } //TODO?
-
-	static GenRandInitFen()
-	{
-		let pieces = { "w": new Array(8), "b": new Array(8) };
-		// Shuffle pieces on first and last rank
-		for (let c of ["w","b"])
-		{
-			let positions = range(8);
-			// Get random squares for every piece, totally freely
-
-			let randIndex = randInt(8);
-			const bishop1Pos = positions[randIndex];
-			positions.splice(randIndex, 1);
-
-			randIndex = randInt(7);
-			const bishop2Pos = positions[randIndex];
-			positions.splice(randIndex, 1);
-
-			randIndex = randInt(6);
-			const knight1Pos = positions[randIndex];
-			positions.splice(randIndex, 1);
-
-			randIndex = randInt(5);
-			const knight2Pos = positions[randIndex];
-			positions.splice(randIndex, 1);
-
-			randIndex = randInt(4);
-			const queenPos = positions[randIndex];
-			positions.splice(randIndex, 1);
-
-			randIndex = randInt(3);
-			const kingPos = positions[randIndex];
-			positions.splice(randIndex, 1);
-
-			randIndex = randInt(2);
-			const rookPos = positions[randIndex];
-			positions.splice(randIndex, 1);
-			const immobilizerPos = positions[0];
-
-			pieces[c][bishop1Pos] = 'b';
-			pieces[c][bishop2Pos] = 'b';
-			pieces[c][knight1Pos] = 'n';
-			pieces[c][knight2Pos] = 'n';
-			pieces[c][queenPos] = 'q';
-			pieces[c][kingPos] = 'k';
-			pieces[c][rookPos] = 'r';
-			pieces[c][immobilizerPos] = 'm';
-		}
-		return pieces["b"].join("") +
-			"/pppppppp/8/8/8/8/PPPPPPPP/" +
-			pieces["w"].join("").toUpperCase() +
-			" w";
-	}
-
-	getNotation(move)
-	{
-		const initialSquare = V.CoordsToSquare(move.start);
-		const finalSquare = V.CoordsToSquare(move.end);
-		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;
-	}
-}
+import { ChessRules, PiPo, Move } from "@/base_rules";
+import { ArrayFun } from "@/utils/array";
+import { shuffle } from "@/utils/alea";
+
+export class BaroqueRules extends ChessRules {
+  static get HasFlags() {
+    return false;
+  }
+
+  static get HasEnpassant() {
+    return false;
+  }
+
+  static get PIECES() {
+    return ChessRules.PIECES.concat([V.IMMOBILIZER]);
+  }
+
+  getPpath(b) {
+    if (b[1] == "m")
+      //'m' for Immobilizer (I is too similar to 1)
+      return "Baroque/" + b;
+    return b; //usual piece
+  }
+
+  // No castling, but checks, so keep track of kings
+  setOtherVariables(fen) {
+    this.kingPos = { w: [-1, -1], b: [-1, -1] };
+    const fenParts = fen.split(" ");
+    const position = fenParts[0].split("/");
+    for (let i = 0; i < position.length; i++) {
+      let k = 0;
+      for (let j = 0; j < position[i].length; j++) {
+        switch (position[i].charAt(j)) {
+          case "k":
+            this.kingPos["b"] = [i, k];
+            break;
+          case "K":
+            this.kingPos["w"] = [i, k];
+            break;
+          default: {
+            const num = parseInt(position[i].charAt(j), 10);
+            if (!isNaN(num)) k += num - 1;
+          }
+        }
+        k++;
+      }
+    }
+  }
+
+  static get IMMOBILIZER() {
+    return "m";
+  }
+  // Although other pieces keep their names here for coding simplicity,
+  // keep in mind that:
+  //  - a "rook" is a coordinator, capturing by coordinating with the king
+  //  - a "knight" is a long-leaper, capturing as in draughts
+  //  - a "bishop" is a chameleon, capturing as its prey
+  //  - a "queen" is a withdrawer, capturing by moving away from pieces
+
+  // Is piece on square (x,y) immobilized?
+  isImmobilized([x, y]) {
+    const piece = this.getPiece(x, y);
+    const color = this.getColor(x, y);
+    const oppCol = V.GetOppCol(color);
+    const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+    for (let step of adjacentSteps) {
+      const [i, j] = [x + step[0], y + step[1]];
+      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.IMMOBILIZER) {
+          // Moving is possible only if this immobilizer is neutralized
+          for (let step2 of adjacentSteps) {
+            const [i2, j2] = [i + step2[0], j + step2[1]];
+            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
+            ) {
+              if ([V.BISHOP, V.IMMOBILIZER].includes(this.getPiece(i2, j2)))
+                return false;
+            }
+          }
+          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 V.IMMOBILIZER:
+        return this.getPotentialImmobilizerMoves([x, y]);
+      default:
+        return super.getPotentialMovesFrom([x, y]);
+    }
+  }
+
+  getSlideNJumpMoves([x, y], steps, oneStep) {
+    const piece = this.getPiece(x, y);
+    let moves = [];
+    outerLoop: for (let step of steps) {
+      let i = x + step[0];
+      let j = y + step[1];
+      while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
+        moves.push(this.getBasicMove([x, y], [i, j]));
+        if (oneStep !== undefined) continue outerLoop;
+        i += step[0];
+        j += step[1];
+      }
+      // Only king can take on occupied square:
+      if (piece == V.KING && V.OnBoard(i, j) && this.canTake([x, y], [i, j]))
+        moves.push(this.getBasicMove([x, y], [i, j]));
+    }
+    return moves;
+  }
+
+  // Modify capturing moves among listed pawn moves
+  addPawnCaptures(moves, byChameleon) {
+    const steps = V.steps[V.ROOK];
+    const color = this.turn;
+    const oppCol = V.GetOppCol(color);
+    moves.forEach(m => {
+      if (!!byChameleon && m.start.x != m.end.x && m.start.y != m.end.y)
+        // Chameleon not moving as pawn
+        return;
+      // Try capturing in every direction
+      for (let step of steps) {
+        const sq2 = [m.end.x + 2 * step[0], m.end.y + 2 * step[1]];
+        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]] != V.EMPTY &&
+            this.getColor(sq1[0], sq1[1]) == oppCol
+          ) {
+            const piece1 = this.getPiece(sq1[0], sq1[1]);
+            if (!byChameleon || piece1 == V.PAWN) {
+              m.vanish.push(
+                new PiPo({
+                  x: sq1[0],
+                  y: sq1[1],
+                  c: oppCol,
+                  p: piece1
+                })
+              );
+            }
+          }
+        }
+      }
+    });
+  }
+
+  // "Pincer"
+  getPotentialPawnMoves([x, y]) {
+    let moves = super.getPotentialRookMoves([x, y]);
+    this.addPawnCaptures(moves);
+    return moves;
+  }
+
+  addRookCaptures(moves, byChameleon) {
+    const color = this.turn;
+    const oppCol = V.GetOppCol(color);
+    const kp = this.kingPos[color];
+    moves.forEach(m => {
+      // 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 = [m.end.x, kp[1]];
+      const corner2 = [kp[0], m.end.y];
+      for (let [i, j] of [corner1, corner2]) {
+        if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == oppCol) {
+          const piece = this.getPiece(i, j);
+          if (!byChameleon || piece == V.ROOK) {
+            m.vanish.push(
+              new PiPo({
+                x: i,
+                y: j,
+                p: piece,
+                c: oppCol
+              })
+            );
+          }
+        }
+      }
+    });
+  }
+
+  // Coordinator
+  getPotentialRookMoves(sq) {
+    let moves = super.getPotentialQueenMoves(sq);
+    this.addRookCaptures(moves);
+    return moves;
+  }
+
+  getKnightCaptures(startSquare, byChameleon) {
+    // Look in every direction for captures
+    const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+    const color = this.turn;
+    const oppCol = V.GetOppCol(color);
+    let moves = [];
+    const [x, y] = [startSquare[0], startSquare[1]];
+    const piece = this.getPiece(x, y); //might be a chameleon!
+    outerLoop: for (let step of steps) {
+      let [i, j] = [x + step[0], y + step[1]];
+      while (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY) {
+        i += step[0];
+        j += step[1];
+      }
+      if (
+        !V.OnBoard(i, j) ||
+        this.getColor(i, j) == color ||
+        (!!byChameleon && this.getPiece(i, j) != V.KNIGHT)
+      ) {
+        continue;
+      }
+      // last(thing), cur(thing) : stop if "cur" is our color,
+      // or beyond board limits, or if "last" isn't empty and cur neither.
+      // Otherwise, if cur is empty then add move until cur square;
+      // if cur is occupied then stop if !!byChameleon and the square not
+      // occupied by a leaper.
+      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 (V.OnBoard(cur[0], cur[1])) {
+        if (this.board[last[0]][last[1]] != V.EMPTY) {
+          const oppPiece = this.getPiece(last[0], last[1]);
+          if (!!byChameleon && oppPiece != V.KNIGHT) continue outerLoop;
+          // Something to eat:
+          vanished.push(
+            new PiPo({ x: last[0], y: last[1], c: oppCol, p: oppPiece })
+          );
+        }
+        if (this.board[cur[0]][cur[1]] != V.EMPTY) {
+          if (
+            this.getColor(cur[0], cur[1]) == color ||
+            this.board[last[0]][last[1]] != V.EMPTY
+          ) {
+            //TODO: redundant test
+            continue outerLoop;
+          }
+        } else {
+          moves.push(
+            new Move({
+              appear: [new PiPo({ x: cur[0], y: cur[1], c: color, p: piece })],
+              vanish: JSON.parse(JSON.stringify(vanished)), //TODO: required?
+              start: { x: x, y: y },
+              end: { x: cur[0], y: cur[1] }
+            })
+          );
+        }
+        last = [last[0] + step[0], last[1] + step[1]];
+        cur = [cur[0] + step[0], cur[1] + step[1]];
+      }
+    }
+    return moves;
+  }
+
+  // Long-leaper
+  getPotentialKnightMoves(sq) {
+    return super.getPotentialQueenMoves(sq).concat(this.getKnightCaptures(sq));
+  }
+
+  // Chameleon
+  getPotentialBishopMoves([x, y]) {
+    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");
+    // Post-processing: merge similar moves, concatenating vanish arrays
+    let mergedMoves = {};
+    moves.forEach(m => {
+      const key = m.end.x + V.size.x * m.end.y;
+      if (!mergedMoves[key]) mergedMoves[key] = m;
+      else {
+        for (let i = 1; i < m.vanish.length; i++)
+          mergedMoves[key].vanish.push(m.vanish[i]);
+      }
+    });
+    return Object.values(mergedMoves);
+  }
+
+  addQueenCaptures(moves, byChameleon) {
+    if (moves.length == 0) return;
+    const [x, y] = [moves[0].start.x, moves[0].start.y];
+    const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+    let capturingDirections = [];
+    const color = this.turn;
+    const oppCol = V.GetOppCol(color);
+    adjacentSteps.forEach(step => {
+      const [i, j] = [x + step[0], y + step[1]];
+      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);
+      }
+    });
+    moves.forEach(m => {
+      const step = [
+        m.end.x != x ? (m.end.x - x) / Math.abs(m.end.x - x) : 0,
+        m.end.y != y ? (m.end.y - y) / Math.abs(m.end.y - y) : 0
+      ];
+      // NOTE: includes() and even _.isEqual() functions fail...
+      // TODO: this test should be done only once per direction
+      if (
+        capturingDirections.some(dir => {
+          return dir[0] == -step[0] && dir[1] == -step[1];
+        })
+      ) {
+        const [i, j] = [x - step[0], y - step[1]];
+        m.vanish.push(
+          new PiPo({
+            x: i,
+            y: j,
+            p: this.getPiece(i, j),
+            c: oppCol
+          })
+        );
+      }
+    });
+  }
+
+  // Withdrawer
+  getPotentialQueenMoves(sq) {
+    let moves = super.getPotentialQueenMoves(sq);
+    this.addQueenCaptures(moves);
+    return moves;
+  }
+
+  getPotentialImmobilizerMoves(sq) {
+    // Immobilizer doesn't capture
+    return super.getPotentialQueenMoves(sq);
+  }
+
+  // isAttacked() is OK because the immobilizer doesn't take
+
+  isAttackedByPawn([x, y], color) {
+    // 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 &&
+            this.getColor(i1, j1) == color &&
+            this.board[i2][j2] == V.EMPTY
+          )
+          ||
+          (
+            this.board[i2][j2] != V.EMPTY &&
+            this.getColor(i2, j2) == color &&
+            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) &&
+              this.getColor(i3, j3) == color &&
+              this.getPiece(i3, j3) == V.PAWN &&
+              !this.isImmobilized([i3, j3])
+            ) {
+              return true;
+            }
+          }
+        }
+      }
+    }
+    return false;
+  }
+
+  isAttackedByRook([x, y], color) {
+    // King must be on same column or row,
+    // and a rook should be able to reach a capturing square
+    const sameRow = x == this.kingPos[color][0];
+    const sameColumn = y == this.kingPos[color][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 &&
+            this.getColor(i, j) == color &&
+            this.getPiece(i, j) == V.ROOK
+          ) {
+            if (this.isImmobilized([i, j]))
+              // Because only one rook:
+              return false;
+            // 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([x, y], color) {
+    // 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) {
+      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 (this.getColor(i, j) == color) {
+              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];
+          }
+        }
+      }
+    }
+    return false;
+  }
+
+  isAttackedByBishop([x, y], color) {
+    // We cheat a little here: since this function is used exclusively for
+    // the 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) {
+      const [i, j] = [x + step[0], y + step[1]];
+      if (
+        V.OnBoard(i, j) &&
+        this.board[i][j] != V.EMPTY &&
+        this.getColor(i, j) == color &&
+        this.getPiece(i, j) == V.BISHOP &&
+        !this.isImmobilized([i, j])
+      ) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  isAttackedByQueen([x, y], color) {
+    // 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) {
+      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 sq1 = [x + step[0], y + step[1]];
+        if (
+          this.board[sq1[0]][sq1[1]] != V.EMPTY &&
+          this.getColor(sq1[0], sq1[1]) == color &&
+          this.getPiece(sq1[0], sq1[1]) == V.QUEEN &&
+          !this.isImmobilized(sq1)
+        ) {
+          return true;
+        }
+      }
+    }
+    return false;
+  }
+
+  isAttackedByKing([x, y], color) {
+    const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+    for (let step of steps) {
+      let rx = x + step[0],
+          ry = y + step[1];
+      if (
+        V.OnBoard(rx, ry) &&
+        this.getPiece(rx, ry) === V.KING &&
+        this.getColor(rx, ry) == color &&
+        !this.isImmobilized([rx, ry])
+      ) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  static GenRandInitFen(randomness) {
+    if (randomness == 0)
+      // Deterministic:
+      return "rnbkqbnm/pppppppp/8/8/8/8/PPPPPPPP/MNBQKBNR w 0";
+
+    let pieces = { w: new Array(8), b: new Array(8) };
+    // Shuffle pieces on first and last rank
+    for (let c of ["w", "b"]) {
+      if (c == 'b' && randomness == 1) {
+        pieces['b'] = pieces['w'];
+        break;
+      }
+
+      // Get random squares for every piece, totally freely
+      let positions = shuffle(ArrayFun.range(8));
+      const composition = ['r', 'n', 'b', 'q', 'k', 'b', 'n', 'm'];
+      for (let i = 0; i < 8; i++) pieces[c][positions[i]] = composition[i];
+    }
+    return (
+      pieces["b"].join("") +
+      "/pppppppp/8/8/8/8/PPPPPPPP/" +
+      pieces["w"].join("").toUpperCase() +
+      " w 0"
+    );
+  }
+
+  static get VALUES() {
+    return {
+      p: 1,
+      r: 2,
+      n: 5,
+      b: 3,
+      q: 3,
+      m: 5,
+      k: 1000
+    };
+  }
+
+  static get SEARCH_DEPTH() {
+    return 2;
+  }
+
+  getNotation(move) {
+    const initialSquare = V.CoordsToSquare(move.start);
+    const finalSquare = V.CoordsToSquare(move.end);
+    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;
+    // Add a capture mark (not describing what is captured...):
+    if (move.vanish.length > 1 && move.appear[0].p != V.KING) notation += "X";
+    return notation;
+  }
+};