X-Git-Url: https://git.auder.net/?p=xogo.git;a=blobdiff_plain;f=base_rules.js;h=88197ea0bed834c970659b95068aa5bec6f0b1aa;hp=a2e5f61f4f78b4fb524263406c612b5a7016e6ca;hb=HEAD;hpb=ca8a399316d2496c069ea9c6ccf2dc241aeb70ef

diff --git a/base_rules.js b/base_rules.js
index a2e5f61..3d8e463 100644
--- a/base_rules.js
+++ b/base_rules.js
@@ -1,5 +1,6 @@
-import { Random } from "/utils/alea.js";
-import { ArrayFun } from "/utils/array.js";
+import {Random} from "/utils/alea.js";
+import {ArrayFun} from "/utils/array.js";
+import {FenUtil} from "/utils/setupPieces.js";
 import PiPo from "/utils/PiPo.js";
 import Move from "/utils/Move.js";
 
@@ -96,6 +97,14 @@ export default class ChessRules {
     return true;
   }
 
+  // Allow to take (moving: not disappearing) own pieces?
+  get hasSelfCaptures() {
+    return (
+      this.options["recycle"] ||
+      (this.options["teleport"] && this.subTurnTeleport == 1)
+    );
+  }
+
   get hasReserve() {
     return (
       !!this.options["crazyhouse"] ||
@@ -111,6 +120,21 @@ export default class ChessRules {
     return !!this.options["dark"];
   }
 
+  // Some variants use only click information
+  get clickOnly() {
+    return false;
+  }
+
+  // Some variants reveal moves only after both players played
+  get hideMoves() {
+    return false;
+  }
+
+  // Some variants do not flip board as black
+  get flippedBoard() {
+    return (this.playerColor == 'b');
+  }
+
   // Some variants use click infos:
   doClick(coords) {
     if (typeof coords.x != "number")
@@ -151,6 +175,22 @@ export default class ChessRules {
     return Object.values(cd).map(c => c.toString(36)).join("");
   }
 
+  // c10 --> 02 (assuming 10 rows)
+  static SquareFromUsual(sq) {
+    return (
+      (this.size.x - parseInt(sq.substring(1), 10)).toString(36) +
+      (sq.charCodeAt(0) - 97).toString(36)
+    );
+  }
+
+  // 02 --> c10
+  static UsualFromSquare(sq) {
+    return (
+      String.fromCharCode(parseInt(sq.charAt(1), 36) + 97) +
+      (this.size.x - parseInt(sq.charAt(0), 36)).toString(10)
+    );
+  }
+
   coordsToId(cd) {
     if (typeof cd.x == "number") {
       return (
@@ -192,88 +232,33 @@ export default class ChessRules {
     return (f.charCodeAt(0) <= 90 ? "w" + f.toLowerCase() : "b" + f);
   }
 
-  // Setup the initial random-or-not (asymmetric-or-not) position
   genRandInitFen(seed) {
-    let fen, flags = "0707";
-    if (!this.options.randomness)
-      // Deterministic:
-      fen = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w 0";
-
-    else {
-      // Randomize
-      Random.setSeed(seed);
-      let pieces = {w: new Array(8), b: new Array(8)};
-      flags = "";
-      // Shuffle pieces on first (and last rank if randomness == 2)
-      for (let c of ["w", "b"]) {
-        if (c == 'b' && this.options.randomness == 1) {
-          pieces['b'] = pieces['w'];
-          flags += flags;
-          break;
-        }
+    Random.setSeed(seed); //may be unused
+    let baseFen = this.genRandInitBaseFen();
+    baseFen.o = Object.assign({init: true}, baseFen.o);
+    const parts = this.getPartFen(baseFen.o);
+    return (
+      baseFen.fen + " w 0" +
+      (Object.keys(parts).length > 0 ? (" " + JSON.stringify(parts)) : "")
+    );
+  }
 
-        let positions = ArrayFun.range(8);
-
-        // Get random squares for bishops
-        let randIndex = 2 * Random.randInt(4);
-        const bishop1Pos = positions[randIndex];
-        // The second bishop must be on a square of different color
-        let randIndex_tmp = 2 * Random.randInt(4) + 1;
-        const bishop2Pos = positions[randIndex_tmp];
-        // Remove chosen squares
-        positions.splice(Math.max(randIndex, randIndex_tmp), 1);
-        positions.splice(Math.min(randIndex, randIndex_tmp), 1);
-
-        // Get random squares for knights
-        randIndex = Random.randInt(6);
-        const knight1Pos = positions[randIndex];
-        positions.splice(randIndex, 1);
-        randIndex = Random.randInt(5);
-        const knight2Pos = positions[randIndex];
-        positions.splice(randIndex, 1);
-
-        // Get random square for queen
-        randIndex = Random.randInt(4);
-        const queenPos = positions[randIndex];
-        positions.splice(randIndex, 1);
-
-        // Rooks and king positions are now fixed,
-        // because of the ordering rook-king-rook
-        const rook1Pos = positions[0];
-        const kingPos = positions[1];
-        const rook2Pos = positions[2];
-
-        // Finally put the shuffled pieces in the board array
-        pieces[c][rook1Pos] = "r";
-        pieces[c][knight1Pos] = "n";
-        pieces[c][bishop1Pos] = "b";
-        pieces[c][queenPos] = "q";
-        pieces[c][kingPos] = "k";
-        pieces[c][bishop2Pos] = "b";
-        pieces[c][knight2Pos] = "n";
-        pieces[c][rook2Pos] = "r";
-        flags += rook1Pos.toString() + rook2Pos.toString();
+  // Setup the initial random-or-not (asymmetric-or-not) position
+  genRandInitBaseFen() {
+    const s = FenUtil.setupPieces(
+      ['r', 'n', 'b', 'q', 'k', 'b', 'n', 'r'],
+      {
+        randomness: this.options["randomness"],
+        between: [{p1: 'k', p2: 'r'}],
+        diffCol: ['b'],
+        flags: ['r']
       }
-      fen = (
-        pieces["b"].join("") +
-        "/pppppppp/8/8/8/8/PPPPPPPP/" +
-        pieces["w"].join("").toUpperCase() +
-        " w 0"
-      );
-    }
-    // Add turn + flags + enpassant (+ reserve)
-    let parts = [];
-    if (this.hasFlags)
-      parts.push(`"flags":"${flags}"`);
-    if (this.hasEnpassant)
-      parts.push('"enpassant":"-"');
-    if (this.hasReserveFen)
-      parts.push('"reserve":"000000000000"');
-    if (this.options["crazyhouse"])
-      parts.push('"ispawn":"-"');
-    if (parts.length >= 1)
-      fen += " {" + parts.join(",") + "}";
-    return fen;
+    );
+    return {
+      fen: s.b.join("") + "/pppppppp/8/8/8/8/PPPPPPPP/" +
+           s.w.join("").toUpperCase(),
+      o: {flags: s.flags}
+    };
   }
 
   // "Parse" FEN: just return untransformed string data
@@ -291,23 +276,28 @@ export default class ChessRules {
 
   // Return current fen (game state)
   getFen() {
-    let fen = (
-      this.getPosition() + " " +
-      this.getTurnFen() + " " +
-      this.movesCount
+    const parts = this.getPartFen({});
+    return (
+      this.getBaseFen() +
+      (Object.keys(parts).length > 0 ? (" " + JSON.stringify(parts)) : "")
     );
-    let parts = [];
+  }
+
+  getBaseFen() {
+    return this.getPosition() + " " + this.turn + " " + this.movesCount;
+  }
+
+  getPartFen(o) {
+    let parts = {};
     if (this.hasFlags)
-      parts.push(`"flags":"${this.getFlagsFen()}"`);
+      parts["flags"] = o.init ? o.flags : this.getFlagsFen();
     if (this.hasEnpassant)
-      parts.push(`"enpassant":"${this.getEnpassantFen()}"`);
+      parts["enpassant"] = o.init ? "-" : this.getEnpassantFen();
     if (this.hasReserveFen)
-      parts.push(`"reserve":"${this.getReserveFen()}"`);
+      parts["reserve"] = this.getReserveFen(o);
     if (this.options["crazyhouse"])
-      parts.push(`"ispawn":"${this.getIspawnFen()}"`);
-    if (parts.length >= 1)
-      fen += " {" + parts.join(",") + "}";
-    return fen;
+      parts["ispawn"] = this.getIspawnFen(o);
+    return parts;
   }
 
   static FenEmptySquares(count) {
@@ -325,9 +315,9 @@ export default class ChessRules {
   // Position part of the FEN string
   getPosition() {
     let position = "";
-    for (let i = 0; i < this.size.y; i++) {
+    for (let i = 0; i < this.size.x; i++) {
       let emptyCount = 0;
-      for (let j = 0; j < this.size.x; j++) {
+      for (let j = 0; j < this.size.y; j++) {
         if (this.board[i][j] == "")
           emptyCount++;
         else {
@@ -342,19 +332,15 @@ export default class ChessRules {
       if (emptyCount > 0)
         // "Flush remainder"
         position += C.FenEmptySquares(emptyCount);
-      if (i < this.size.y - 1)
+      if (i < this.size.x - 1)
         position += "/"; //separate rows
     }
     return position;
   }
 
-  getTurnFen() {
-    return this.turn;
-  }
-
   // Flags part of the FEN string
   getFlagsFen() {
-    return ["w", "b"].map(c => {
+    return ['w', 'b'].map(c => {
       return this.castleFlags[c].map(x => x.toString(36)).join("");
     }).join("");
   }
@@ -362,17 +348,22 @@ export default class ChessRules {
   // Enpassant part of the FEN string
   getEnpassantFen() {
     if (!this.epSquare)
-      return "-"; //no en-passant
+      return "-";
     return C.CoordsToSquare(this.epSquare);
   }
 
-  getReserveFen() {
+  getReserveFen(o) {
+    if (o.init)
+      return Array(2 * V.ReserveArray.length).fill('0').join("");
     return (
-      ["w","b"].map(c => Object.values(this.reserve[c]).join("")).join("")
+      ['w', 'b'].map(c => Object.values(this.reserve[c]).join("")).join("")
     );
   }
 
-  getIspawnFen() {
+  getIspawnFen(o) {
+    if (o.init)
+      // NOTE: cannot merge because this.ispawn doesn't exist yet
+      return "-";
     const squares = Object.keys(this.ispawn);
     if (squares.length == 0)
       return "-";
@@ -397,19 +388,18 @@ export default class ChessRules {
       if (this.options[opt.variable] === undefined)
         this.options[opt.variable] = opt.defaut;
     });
-    if (o.genFenOnly)
-      // This object will be used only for initial FEN generation
-      return;
+
+    // Some variables
     this.playerColor = o.color;
     this.afterPlay = o.afterPlay; //trigger some actions after playing a move
+    this.containerId = o.element;
+    this.isDiagram = o.diagram;
+    this.marks = o.marks;
 
-    // Fen string fully describes the game state
+    // Initializations
     if (!o.fen)
       o.fen = this.genRandInitFen(o.seed);
     this.re_initFromFen(o.fen);
-
-    // Graphical (can use variables defined above)
-    this.containerId = o.element;
     this.graphicalInit();
   }
 
@@ -448,7 +438,7 @@ export default class ChessRules {
       this.setFlags(fenParsed.flags);
     if (this.hasEnpassant)
       this.epSquare = this.getEpSquare(fenParsed.enpassant);
-    if (this.hasReserve)
+    if (this.hasReserve && !this.isDiagram)
       this.initReserves(fenParsed.reserve);
     if (this.options["crazyhouse"])
       this.initIspawn(fenParsed.ispawn);
@@ -467,17 +457,17 @@ export default class ChessRules {
   }
 
   // ordering as in pieces() p,r,n,b,q,k
+  static get ReserveArray() {
+    return ['p', 'r', 'n', 'b', 'q', 'k'];
+  }
+
   initReserves(reserveStr) {
     const counts = reserveStr.split("").map(c => parseInt(c, 36));
-    this.reserve = { w: {}, b: {} };
-    const pieceName = ['p', 'r', 'n', 'b', 'q', 'k'];
-    const L = pieceName.length;
-    for (let i of ArrayFun.range(2 * L)) {
-      if (i < L)
-        this.reserve['w'][pieceName[i]] = counts[i];
-      else
-        this.reserve['b'][pieceName[i-L]] = counts[i];
-    }
+    const L = V.ReserveArray.length;
+    this.reserve = {
+      w: ArrayFun.toObject(V.ReserveArray, counts.slice(0, L)),
+      b: ArrayFun.toObject(V.ReserveArray, counts.slice(L, 2 * L))
+    };
   }
 
   initIspawn(ispawnStr) {
@@ -491,7 +481,7 @@ export default class ChessRules {
   // VISUAL UTILS
 
   getPieceWidth(rwidth) {
-    return (rwidth / this.size.y);
+    return (rwidth / Math.max(this.size.x, this.size.y));
   }
 
   getReserveSquareSize(rwidth, nbR) {
@@ -511,27 +501,23 @@ export default class ChessRules {
   }
 
   getRankInReserve(c, p) {
-    const pieces = Object.keys(this.pieces());
+    const pieces = Object.keys(this.pieces(c, c, p));
     const lastIndex = pieces.findIndex(pp => pp == p)
     let toTest = pieces.slice(0, lastIndex);
     return toTest.reduce(
       (oldV,newV) => oldV + (this.reserve[c][newV] > 0 ? 1 : 0), 0);
   }
 
-  static AddClass_es(piece, class_es) {
+  static AddClass_es(elt, class_es) {
     if (!Array.isArray(class_es))
       class_es = [class_es];
-    class_es.forEach(cl => {
-      piece.classList.add(cl);
-    });
+    class_es.forEach(cl => elt.classList.add(cl));
   }
 
-  static RemoveClass_es(piece, class_es) {
+  static RemoveClass_es(elt, class_es) {
     if (!Array.isArray(class_es))
       class_es = [class_es];
-    class_es.forEach(cl => {
-      piece.classList.remove(cl);
-    });
+    class_es.forEach(cl => elt.classList.remove(cl));
   }
 
   // Generally light square bottom-right
@@ -552,54 +538,56 @@ export default class ChessRules {
   // VISUAL METHODS
 
   graphicalInit() {
-    // NOTE: not window.onresize = this.re_drawBoardElts because scope (this)
-    window.onresize = () => this.re_drawBoardElements();
-    this.re_drawBoardElements();
-    this.initMouseEvents();
-    const chessboard =
-      document.getElementById(this.containerId).querySelector(".chessboard");
+    const g_init = () => {
+      this.re_drawBoardElements();
+      if (!this.isDiagram && !this.mouseListeners && !this.touchListeners)
+        this.initMouseEvents();
+    };
+    let container = document.getElementById(this.containerId);
+    this.windowResizeObs = new ResizeObserver(g_init);
+    this.windowResizeObs.observe(container);
   }
 
   re_drawBoardElements() {
     const board = this.getSvgChessboard();
-    const oppCol = C.GetOppCol(this.playerColor);
-    let chessboard =
-      document.getElementById(this.containerId).querySelector(".chessboard");
+    const container = document.getElementById(this.containerId);
+    const rc = container.getBoundingClientRect();
+    let chessboard = container.querySelector(".chessboard");
     chessboard.innerHTML = "";
     chessboard.insertAdjacentHTML('beforeend', board);
     // Compare window ratio width / height to aspectRatio:
-    const windowRatio = window.innerWidth / window.innerHeight;
+    const windowRatio = rc.width / rc.height;
     let cbWidth, cbHeight;
     const vRatio = this.size.ratio || 1;
     if (windowRatio <= vRatio) {
       // Limiting dimension is width:
-      cbWidth = Math.min(window.innerWidth, 767);
+      cbWidth = Math.min(rc.width, 767);
       cbHeight = cbWidth / vRatio;
     }
     else {
       // Limiting dimension is height:
-      cbHeight = Math.min(window.innerHeight, 767);
+      cbHeight = Math.min(rc.height, 767);
       cbWidth = cbHeight * vRatio;
     }
-    if (this.hasReserve) {
+    if (this.hasReserve && !this.isDiagram) {
       const sqSize = cbWidth / this.size.y;
       // NOTE: allocate space for reserves (up/down) even if they are empty
       // Cannot use getReserveSquareSize() here, but sqSize is an upper bound.
-      if ((window.innerHeight - cbHeight) / 2 < sqSize + 5) {
-        cbHeight = window.innerHeight - 2 * (sqSize + 5);
+      if ((rc.height - cbHeight) / 2 < sqSize + 5) {
+        cbHeight = rc.height - 2 * (sqSize + 5);
         cbWidth = cbHeight * vRatio;
       }
     }
     chessboard.style.width = cbWidth + "px";
     chessboard.style.height = cbHeight + "px";
     // Center chessboard:
-    const spaceLeft = (window.innerWidth - cbWidth) / 2,
-          spaceTop = (window.innerHeight - cbHeight) / 2;
+    const spaceLeft = (rc.width - cbWidth) / 2,
+          spaceTop = (rc.height - cbHeight) / 2;
     chessboard.style.left = spaceLeft + "px";
     chessboard.style.top = spaceTop + "px";
     // Give sizes instead of recomputing them,
     // because chessboard might not be drawn yet.
-    this.setupPieces({
+    this.setupVisualPieces({
       width: cbWidth,
       height: cbHeight,
       x: spaceLeft,
@@ -609,13 +597,22 @@ export default class ChessRules {
 
   // Get SVG board (background, no pieces)
   getSvgChessboard() {
-    const flipped = (this.playerColor == 'b');
     let board = `
       <svg
         viewBox="0 0 ${10*this.size.y} ${10*this.size.x}"
         class="chessboard_SVG">`;
+    board += this.getBaseSvgChessboard();
+    board += "</svg>";
+    return board;
+  }
+
+  getBaseSvgChessboard() {
+    let board = "";
+    const flipped = this.flippedBoard;
     for (let i=0; i < this.size.x; i++) {
       for (let j=0; j < this.size.y; j++) {
+        if (!this.onBoard(i, j))
+          continue;
         const ii = (flipped ? this.size.x - 1 - i : i);
         const jj = (flipped ? this.size.y - 1 - j : j);
         let classes = this.getSquareColorClass(ii, jj);
@@ -633,51 +630,70 @@ export default class ChessRules {
           />`;
       }
     }
-    board += "</svg>";
     return board;
   }
 
-  setupPieces(r) {
-    if (this.g_pieces) {
-      // Refreshing: delete old pieces first
-      for (let i=0; i<this.size.x; i++) {
-        for (let j=0; j<this.size.y; j++) {
-          if (this.g_pieces[i][j]) {
-            this.g_pieces[i][j].remove();
-            this.g_pieces[i][j] = null;
-          }
-        }
-      }
-    }
-    else
-      this.g_pieces = ArrayFun.init(this.size.x, this.size.y, null);
+  setupVisualPieces(r) {
     let chessboard =
       document.getElementById(this.containerId).querySelector(".chessboard");
     if (!r)
       r = chessboard.getBoundingClientRect();
     const pieceWidth = this.getPieceWidth(r.width);
+    const addPiece = (i, j, arrName, classes) => {
+      this[arrName][i][j] = document.createElement("piece");
+      C.AddClass_es(this[arrName][i][j], classes);
+      this[arrName][i][j].style.width = pieceWidth + "px";
+      this[arrName][i][j].style.height = pieceWidth + "px";
+      let [ip, jp] = this.getPixelPosition(i, j, r);
+      // Translate coordinates to use chessboard as reference:
+      this[arrName][i][j].style.transform =
+        `translate(${ip - r.x}px,${jp - r.y}px)`;
+      chessboard.appendChild(this[arrName][i][j]);
+    };
+    const conditionalReset = (arrName) => {
+      if (this[arrName]) {
+        // Refreshing: delete old pieces first. This isn't necessary,
+        // but simpler (this method isn't called many times)
+        for (let i=0; i<this.size.x; i++) {
+          for (let j=0; j<this.size.y; j++) {
+            if (this[arrName][i][j]) {
+              this[arrName][i][j].remove();
+              this[arrName][i][j] = null;
+            }
+          }
+        }
+      }
+      else
+        this[arrName] = ArrayFun.init(this.size.x, this.size.y, null);
+      if (arrName == "d_pieces")
+        this.marks.forEach((m) => {
+          const formattedSquare = C.SquareFromUsual(m);
+          const mCoords = C.SquareToCoords(formattedSquare);
+          addPiece(mCoords.x, mCoords.y, arrName, "mark");
+        });
+    };
+    if (this.marks)
+      conditionalReset("d_pieces");
+    conditionalReset("g_pieces");
     for (let i=0; i < this.size.x; i++) {
       for (let j=0; j < this.size.y; j++) {
         if (this.board[i][j] != "") {
           const color = this.getColor(i, j);
           const piece = this.getPiece(i, j);
-          this.g_pieces[i][j] = document.createElement("piece");
-          C.AddClass_es(this.g_pieces[i][j],
-                        this.pieces(color, i, j)[piece]["class"]);
-          this.g_pieces[i][j].classList.add(C.GetColorClass(color));
-          this.g_pieces[i][j].style.width = pieceWidth + "px";
-          this.g_pieces[i][j].style.height = pieceWidth + "px";
-          let [ip, jp] = this.getPixelPosition(i, j, r);
-          // Translate coordinates to use chessboard as reference:
-          this.g_pieces[i][j].style.transform =
-            `translate(${ip - r.x}px,${jp - r.y}px)`;
+          addPiece(i, j, "g_pieces", this.pieces(color, i, j)[piece]["class"]);
+          this.g_pieces[i][j].classList.add(V.GetColorClass(color));
           if (this.enlightened && !this.enlightened[i][j])
             this.g_pieces[i][j].classList.add("hidden");
-          chessboard.appendChild(this.g_pieces[i][j]);
+        }
+        if (this.marks && this.d_pieces[i][j]) {
+          let classes = ["mark"];
+          if (this.board[i][j] != "")
+            classes.push("transparent");
+          addPiece(i, j, "d_pieces", classes);
         }
       }
     }
-    if (this.hasReserve)
+    if (this.hasReserve && !this.isDiagram)
       this.re_drawReserve(['w', 'b'], r);
   }
 
@@ -732,7 +748,7 @@ export default class ChessRules {
         rcontainer.appendChild(r_cell);
         let piece = document.createElement("piece");
         C.AddClass_es(piece, this.pieces(c, c, p)[p]["class"]);
-        piece.classList.add(C.GetColorClass(c));
+        piece.classList.add(V.GetColorClass(c));
         piece.style.width = "100%";
         piece.style.height = "100%";
         this.r_pieces[c][p] = piece;
@@ -755,8 +771,8 @@ export default class ChessRules {
       piece = "k"; //capturing cannibal king: back to king form
     const oldCount = this.reserve[color][piece];
     this.reserve[color][piece] = count;
-    // Redrawing is much easier if count==0
-    if ([oldCount, count].includes(0))
+    // Redrawing is much easier if count==0 (or undefined)
+    if ([oldCount, count].some(item => !item))
       this.re_drawReserve([color]);
     else {
       const numId = this.getReserveNumId(color, piece);
@@ -766,26 +782,27 @@ export default class ChessRules {
 
   // Resize board: no need to destroy/recreate pieces
   rescale(mode) {
-    let chessboard =
-      document.getElementById(this.containerId).querySelector(".chessboard");
-    const r = chessboard.getBoundingClientRect();
+    const container = document.getElementById(this.containerId);
+    let chessboard = container.querySelector(".chessboard");
+    const rc = container.getBoundingClientRect(),
+          r = chessboard.getBoundingClientRect();
     const multFact = (mode == "up" ? 1.05 : 0.95);
     let [newWidth, newHeight] = [multFact * r.width, multFact * r.height];
     // Stay in window:
     const vRatio = this.size.ratio || 1;
-    if (newWidth > window.innerWidth) {
-      newWidth = window.innerWidth;
+    if (newWidth > rc.width) {
+      newWidth = rc.width;
       newHeight = newWidth / vRatio;
     }
-    if (newHeight > window.innerHeight) {
-      newHeight = window.innerHeight;
+    if (newHeight > rc.height) {
+      newHeight = rc.height;
       newWidth = newHeight * vRatio;
     }
     chessboard.style.width = newWidth + "px";
     chessboard.style.height = newHeight + "px";
-    const newX = (window.innerWidth - newWidth) / 2;
+    const newX = (rc.width - newWidth) / 2;
     chessboard.style.left = newX + "px";
-    const newY = (window.innerHeight - newHeight) / 2;
+    const newY = (rc.height - newHeight) / 2;
     chessboard.style.top = newY + "px";
     const newR = {x: newX, y: newY, width: newWidth, height: newHeight};
     const pieceWidth = this.getPieceWidth(newWidth);
@@ -853,9 +870,10 @@ export default class ChessRules {
       y = (this.playerColor == i ? y = r.height + 5 : - 5 - rsqSize);
     }
     else {
-      const sqSize = r.width / this.size.y;
-      const flipped = (this.playerColor == 'b');
-      x = (flipped ? this.size.y - 1 - j : j) * sqSize;
+      const sqSize = r.width / Math.max(this.size.x, this.size.y);
+      const flipped = this.flippedBoard;
+      x = (flipped ? this.size.y - 1 - j : j) * sqSize +
+          Math.abs(this.size.x - this.size.y) * sqSize / 2;
       y = (flipped ? this.size.x - 1 - i : i) * sqSize;
     }
     return [r.x + x, r.y + y];
@@ -903,7 +921,7 @@ export default class ChessRules {
         const move = this.doClick(cd);
         if (move)
           this.buildMoveStack(move, r);
-        else {
+        else if (!this.clickOnly) {
           const [x, y] = Object.values(cd);
           if (typeof x != "number")
             startPiece = this.r_pieces[x][y];
@@ -961,22 +979,50 @@ export default class ChessRules {
       curPiece.remove();
     };
 
+    const resize = (e) => this.rescale(e.deltaY < 0 ? "up" : "down");
+
     if ('onmousedown' in window) {
-      document.addEventListener("mousedown", mousedown);
-      document.addEventListener("mousemove", mousemove);
-      document.addEventListener("mouseup", mouseup);
-      document.addEventListener("wheel",
-        (e) => this.rescale(e.deltaY < 0 ? "up" : "down"));
+      this.mouseListeners = [
+        {type: "mousedown", listener: mousedown},
+        {type: "mousemove", listener: mousemove},
+        {type: "mouseup", listener: mouseup},
+        {type: "wheel", listener: resize}
+      ];
+      this.mouseListeners.forEach(ml => {
+        document.addEventListener(ml.type, ml.listener);
+      });
     }
     if ('ontouchstart' in window) {
-      // https://stackoverflow.com/a/42509310/12660887
-      document.addEventListener("touchstart", mousedown, {passive: false});
-      document.addEventListener("touchmove", mousemove, {passive: false});
-      document.addEventListener("touchend", mouseup, {passive: false});
+      this.touchListeners = [
+        {type: "touchstart", listener: mousedown},
+        {type: "touchmove", listener: mousemove},
+        {type: "touchend", listener: mouseup}
+      ];
+      this.touchListeners.forEach(tl => {
+        // https://stackoverflow.com/a/42509310/12660887
+        document.addEventListener(tl.type, tl.listener, {passive: false});
+      });
     }
     // TODO: onpointerdown/move/up ? See reveal.js /controllers/touch.js
   }
 
+  // NOTE: not called if isDiagram
+  removeListeners() {
+    let container = document.getElementById(this.containerId);
+    this.windowResizeObs.unobserve(container);
+    if ('onmousedown' in window) {
+      this.mouseListeners.forEach(ml => {
+        document.removeEventListener(ml.type, ml.listener);
+      });
+    }
+    if ('ontouchstart' in window) {
+      this.touchListeners.forEach(tl => {
+        // https://stackoverflow.com/a/42509310/12660887
+        document.removeEventListener(tl.type, tl.listener);
+      });
+    }
+  }
+
   showChoices(moves, r) {
     let container = document.getElementById(this.containerId);
     let chessboard = container.querySelector(".chessboard");
@@ -1012,7 +1058,7 @@ export default class ChessRules {
       const cdisp = moves[i].choice || moves[i].appear[0].p;
       C.AddClass_es(piece,
         this.pieces(color, moves[i].end.x, moves[i].end.y)[cdisp]["class"]);
-      piece.classList.add(C.GetColorClass(color));
+      piece.classList.add(V.GetColorClass(color));
       piece.style.width = "100%";
       piece.style.height = "100%";
       choice.appendChild(piece);
@@ -1020,6 +1066,21 @@ export default class ChessRules {
     }
   }
 
+  displayMessage(elt, msg, classe_s, timeout) {
+    if (elt)
+      // Fixed element, e.g. for Dice Chess
+      elt.innerHTML = msg;
+    else {
+      // Temporary div (Chakart, Apocalypse...)
+      let divMsg = document.createElement("div");
+      C.AddClass_es(divMsg, classe_s);
+      divMsg.innerHTML = msg;
+      let container = document.getElementById(this.containerId);
+      container.appendChild(divMsg);
+      setTimeout(() => container.removeChild(divMsg), timeout);
+    }
+  }
+
   ////////////////
   // DARK METHODS
 
@@ -1045,9 +1106,10 @@ export default class ChessRules {
   // Include square of the en-passant capturing square:
   enlightEnpassant() {
     // NOTE: shortcut, pawn has only one attack type, doesn't depend on square
-    const steps = this.pieces(this.playerColor)["p"].attack[0].steps;
+    // TODO: (0, 0) is wrong, would need to place an attacker here...
+    const steps = this.pieces(this.playerColor, 0, 0)["p"].attack[0].steps;
     for (let step of steps) {
-      const x = this.epSquare.x - step[0],
+      const x = this.epSquare.x - step[0], //NOTE: epSquare.x not on edge
             y = this.getY(this.epSquare.y - step[1]);
       if (
         this.onBoard(x, y) &&
@@ -1118,14 +1180,26 @@ export default class ChessRules {
   }
 
   // Piece type on square (i,j)
-  getPieceType(i, j, p) {
+  getPieceType(x, y, p) {
     if (!p)
-      p = this.getPiece(i, j);
-    return C.CannibalKings[p] || p; //a cannibal king move as...
+      p = this.getPiece(x, y);
+    return this.pieces(this.getColor(x, y), x, y)[p].moveas || p;
+  }
+
+  isKing(x, y, p) {
+    if (!p)
+      p = this.getPiece(x, y);
+    if (!this.options["cannibal"])
+      return p == 'k';
+    return !!C.CannibalKings[p];
+  }
+
+  static GetOppTurn(color) {
+    return (color == 'w' ? 'b' : 'w');
   }
 
-  // Get opponent color
-  static GetOppCol(color) {
+  // Get opponent color(s): may differ from turn (e.g. Checkered)
+  getOppCols(color) {
     return (color == "w" ? "b" : "w");
   }
 
@@ -1143,17 +1217,22 @@ export default class ChessRules {
   ////////////////////////
   // PIECES SPECIFICATIONS
 
+  getPawnShift(color) {
+    return (color == "w" ? -1 : 1);
+  }
+  isPawnInitRank(x, color) {
+    return (color == 'w' && x >= 6) || (color == 'b' && x <= 1);
+  }
+
   pieces(color, x, y) {
-    const pawnShift = (color == "w" ? -1 : 1);
-    // NOTE: jump 2 squares from first rank (pawns can be here sometimes)
-    const initRank = ((color == 'w' && x >= 6) || (color == 'b' && x <= 1));
+    const pawnShift = this.getPawnShift(color || 'w');
     return {
       'p': {
         "class": "pawn",
         moves: [
           {
             steps: [[pawnShift, 0]],
-            range: (initRank ? 2 : 1)
+            range: (this.isPawnInitRank(x, color) ? 2 : 1)
           }
         ],
         attack: [
@@ -1165,13 +1244,13 @@ export default class ChessRules {
       },
       'r': {
         "class": "rook",
-        moves: [
+        both: [
           {steps: [[0, 1], [0, -1], [1, 0], [-1, 0]]}
         ]
       },
       'n': {
         "class": "knight",
-        moves: [
+        both: [
           {
             steps: [
               [1, 2], [1, -2], [-1, 2], [-1, -2],
@@ -1183,13 +1262,13 @@ export default class ChessRules {
       },
       'b': {
         "class": "bishop",
-        moves: [
+        both: [
           {steps: [[1, 1], [1, -1], [-1, 1], [-1, -1]]}
         ]
       },
       'q': {
         "class": "queen",
-        moves: [
+        both: [
           {
             steps: [
               [0, 1], [0, -1], [1, 0], [-1, 0],
@@ -1200,7 +1279,7 @@ export default class ChessRules {
       },
       'k': {
         "class": "king",
-        moves: [
+        both: [
           {
             steps: [
               [0, 1], [0, -1], [1, 0], [-1, 0],
@@ -1254,6 +1333,17 @@ export default class ChessRules {
       res += this.size.y;
     return res;
   }
+  // Circular?
+  getX(x) {
+    return x; //generally, no
+  }
+
+  increment([x, y], step) {
+    return [
+      this.getX(x + step[0]),
+      this.getY(y + step[1])
+    ];
+  }
 
   getSegments(curSeg, segStart, segEnd) {
     if (curSeg.length == 0)
@@ -1263,12 +1353,21 @@ export default class ChessRules {
     return segments;
   }
 
-  getStepSpec(color, x, y) {
-    const allSpecs = this.pieces(color, x, y);
-    let stepSpec = allSpecs[piece];
-    if (stepSpec.moveas)
-      stepSpec = allSpecs[stepSpec.moveas];
-    return stepSpec;
+  getStepSpec(color, x, y, piece) {
+    let pieceType = piece;
+    let allSpecs = this.pieces(color, x, y);
+    if (!piece)
+      pieceType = this.getPieceType(x, y);
+    else if (allSpecs[piece].moveas)
+      pieceType = allSpecs[piece].moveas;
+    let res = allSpecs[pieceType];
+    if (!res["both"])
+      res.both = [];
+    if (!res["moves"])
+      res.moves = [];
+    if (!res["attack"])
+      res.attack = [];
+    return res;
   }
 
   // Can thing on square1 capture thing on square2?
@@ -1276,6 +1375,11 @@ export default class ChessRules {
     return this.getColor(x1, y1) !== this.getColor(x2, y2);
   }
 
+  // Teleport & Recycle. Assumption: color(x1,y1) == color(x2,y2)
+  canSelfTake([x1, y1], [x2, y2]) {
+    return !this.isKing(x2, y2);
+  }
+
   canStepOver(i, j, p) {
     // In some variants, objects on boards don't stop movement (Chakart)
     return this.board[i][j] == "";
@@ -1299,23 +1403,22 @@ export default class ChessRules {
     if (!this.options["madrasi"])
       return false;
     const color = this.getColor(x, y);
-    const oppCol = C.GetOppCol(color);
-    const piece = this.getPieceType(x, y); //ok not cannibal king
-    const stepSpec = this.getStepSpec(color, x, y);
-    const attacks = stepSpec.attack || stepSpec.moves;
+    const oppCols = this.getOppCols(color);
+    const piece = this.getPieceType(x, y);
+    const stepSpec = this.getStepSpec(color, x, y, piece);
+    const attacks = stepSpec.both.concat(stepSpec.attack);
     for (let a of attacks) {
       outerLoop: for (let step of a.steps) {
-        let [i, j] = [x + step[0], y + step[1]];
-        let stepCounter = 1;
+        let [i, j] = this.increment([x, y], step);
+        let stepCounter = 0;
         while (this.onBoard(i, j) && this.board[i][j] == "") {
           if (a.range <= stepCounter++)
             continue outerLoop;
-          i += step[0];
-          j = this.getY(j + step[1]);
+          [i, j] = this.increment([i, j], step);
         }
         if (
           this.onBoard(i, j) &&
-          this.getColor(i, j) == oppCol &&
+          oppCols.includes(this.getColor(i, j)) &&
           this.getPieceType(i, j) == piece
         ) {
           return true;
@@ -1327,19 +1430,41 @@ export default class ChessRules {
 
   // Stop at the first capture found
   atLeastOneCapture(color) {
-    const oppCol = C.GetOppCol(color);
-    const allowed = ([x, y]) => {
-      this.getColor(x, y) == oppCol &&
-      this.filterValid([this.getBasicMove([i, j], [x, y])]).length >= 1
+    const allowed = (sq1, sq2) => {
+      return (
+        // NOTE: canTake is reversed for Zen.
+        // Generally ok because of the symmetry. TODO?
+        this.canTake(sq1, sq2) &&
+        this.filterValid(
+          [this.getBasicMove(sq1, sq2)]).length >= 1
+      );
     };
     for (let i=0; i<this.size.x; i++) {
       for (let j=0; j<this.size.y; j++) {
         if (this.getColor(i, j) == color) {
           if (
-            (!this.options["zen"] && this.findDestSquares(
-              [i, j], {attackOnly: true, one: true}, allowed).length == 1) ||
-            (this.options["zen"] && this.findCapturesOn(
-              [i, j], {one: true}, allowed).length == 1)
+            (
+              !this.options["zen"] &&
+              this.findDestSquares(
+                [i, j],
+                {
+                  attackOnly: true,
+                  one: true,
+                },
+                allowed
+              )
+            )
+            ||
+            (
+              (
+                this.options["zen"] &&
+                this.findCapturesOn(
+                  [i, j],
+                  {one: true},
+                  allowed
+                )
+              )
+            )
           ) {
             return true;
           }
@@ -1350,6 +1475,7 @@ export default class ChessRules {
   }
 
   compatibleStep([x1, y1], [x2, y2], step, range) {
+    const epsilon = 1e-7; //arbitrary small value
     let shifts = [0];
     if (this.options["cylinder"])
       Array.prototype.push.apply(shifts, [-this.size.y, this.size.y]);
@@ -1357,17 +1483,21 @@ export default class ChessRules {
       const rx = (x2 - x1) / step[0],
             ry = (y2 + sh - y1) / step[1];
       if (
+        // Zero step but non-zero interval => impossible
         (!Number.isFinite(rx) && !Number.isNaN(rx)) ||
-        (!Number.isFinite(ry) && !Number.isNaN(ry))
+        (!Number.isFinite(ry) && !Number.isNaN(ry)) ||
+        // Negative number of step (impossible)
+        (rx < 0 || ry < 0) ||
+        // Not the same number of steps in both directions:
+        (!Number.isNaN(rx) && !Number.isNaN(ry) && Math.abs(rx - ry) > epsilon)
       ) {
         continue;
       }
       let distance = (Number.isNaN(rx) ? ry : rx);
-      // TODO: 1e-7 here is totally arbitrary
-      if (Math.abs(distance - Math.round(distance)) > 1e-7)
+      if (Math.abs(distance - Math.round(distance)) > epsilon)
         continue;
       distance = Math.round(distance); //in case of (numerical...)
-      if (range >= distance)
+      if (!range || range >= distance)
         return true;
     }
     return false;
@@ -1384,7 +1514,7 @@ export default class ChessRules {
     let moves = [];
     for (let i=0; i<this.size.x; i++) {
       for (let j=0; j<this.size.y; j++) {
-        if (this.canDrop([c, p], [i, j])) {
+        if (this.onBoard(i, j) && this.canDrop([c, p], [i, j])) {
           let mv = new Move({
             start: {x: c, y: p},
             end: {x: i, y: j},
@@ -1407,6 +1537,7 @@ export default class ChessRules {
   }
 
   // All possible moves from selected square
+  // TODO: generalize usage if arg "color" (e.g. Checkered)
   getPotentialMovesFrom([x, y], color) {
     if (this.subTurnTeleport == 2)
       return [];
@@ -1418,12 +1549,8 @@ export default class ChessRules {
     let moves = this.getPotentialMovesOf(piece, [x, y]);
     if (piece == "p" && this.hasEnpassant && this.epSquare)
       Array.prototype.push.apply(moves, this.getEnpassantCaptures([x, y]));
-    if (
-      piece == "k" && this.hasCastle &&
-      this.castleFlags[color || this.turn].some(v => v < this.size.y)
-    ) {
+    if (this.isKing(0, 0, piece) && this.hasCastle)
       Array.prototype.push.apply(moves, this.getCastleMoves([x, y]));
-    }
     return this.postProcessPotentialMoves(moves);
   }
 
@@ -1431,48 +1558,44 @@ export default class ChessRules {
     if (moves.length == 0)
       return [];
     const color = this.getColor(moves[0].start.x, moves[0].start.y);
-    const oppCol = C.GetOppCol(color);
+    const oppCols = this.getOppCols(color);
 
-    if (this.options["capture"] && this.atLeastOneCapture())
-      moves = this.capturePostProcess(moves, oppCol);
+    if (this.options["capture"] && this.atLeastOneCapture(color))
+      moves = this.capturePostProcess(moves, oppCols);
 
     if (this.options["atomic"])
-      this.atomicPostProcess(moves, color, oppCol);
+      moves = this.atomicPostProcess(moves, color, oppCols);
 
     if (
       moves.length > 0 &&
       this.getPieceType(moves[0].start.x, moves[0].start.y) == "p"
     ) {
-      this.pawnPostProcess(moves, color, oppCol);
+      moves = this.pawnPostProcess(moves, color, oppCols);
     }
 
-    if (
-      this.options["cannibal"] &&
-      this.options["rifle"]
-    ) {
+    if (this.options["cannibal"] && this.options["rifle"])
       // In this case a rifle-capture from last rank may promote a pawn
-      this.riflePromotePostProcess(moves, color);
-    }
+      moves = this.riflePromotePostProcess(moves, color);
 
     return moves;
   }
 
-  capturePostProcess(moves, oppCol) {
+  capturePostProcess(moves, oppCols) {
     // Filter out non-capturing moves (not using m.vanish because of
     // self captures of Recycle and Teleport).
     return moves.filter(m => {
       return (
         this.board[m.end.x][m.end.y] != "" &&
-        this.getColor(m.end.x, m.end.y) == oppCol
+        oppCols.includes(this.getColor(m.end.x, m.end.y))
       );
     });
   }
 
-  atomicPostProcess(moves, color, oppCol) {
+  atomicPostProcess(moves, color, oppCols) {
     moves.forEach(m => {
       if (
         this.board[m.end.x][m.end.y] != "" &&
-        this.getColor(m.end.x, m.end.y) == oppCol
+        oppCols.includes(this.getColor(m.end.x, m.end.y))
       ) {
         // Explosion!
         let steps = [
@@ -1492,8 +1615,7 @@ export default class ChessRules {
           vanish: []
         });
         for (let step of steps) {
-          let x = m.end.x + step[0];
-          let y = this.getY(m.end.y + step[1]);
+          let [x, y] = this.increment([m.end.x, m.end.y], step);
           if (
             this.onBoard(x, y) &&
             this.board[x][y] != "" &&
@@ -1524,9 +1646,10 @@ export default class ChessRules {
         m.next = mNext;
       }
     });
+    return moves;
   }
 
-  pawnPostProcess(moves, color, oppCol) {
+  pawnPostProcess(moves, color, oppCols) {
     let moreMoves = [];
     const lastRank = (color == "w" ? 0 : this.size.x - 1);
     const initPiece = this.getPiece(moves[0].start.x, moves[0].start.y);
@@ -1543,11 +1666,11 @@ export default class ChessRules {
         m.appear.shift();
         return;
       }
-      let finalPieces = ["p"];
+      let finalPieces;
       if (
         this.options["cannibal"] &&
         this.board[x2][y2] != "" &&
-        this.getColor(x2, y2) == oppCol
+        oppCols.includes(this.getColor(x2, y2))
       ) {
         finalPieces = [this.getPieceType(x2, y2)];
       }
@@ -1557,16 +1680,13 @@ export default class ChessRules {
       if (initPiece == "!") //cannibal king-pawn
         m.appear[0].p = C.CannibalKingCode[finalPieces[0]];
       for (let i=1; i<finalPieces.length; i++) {
+        let newMove = JSON.parse(JSON.stringify(m));
         const piece = finalPieces[i];
-        const tr = {
-          c: color,
-          p: (initPiece != "!" ? piece : C.CannibalKingCode[piece])
-        };
-        let newMove = this.getBasicMove([x1, y1], [x2, y2], tr);
+        m.appear[0].p = (initPiece != "!" ? piece : C.CannibalKingCode[piece]);
         moreMoves.push(newMove);
       }
     });
-    Array.prototype.push.apply(moves, moreMoves);
+    return moves.concat(moreMoves);
   }
 
   riflePromotePostProcess(moves, color) {
@@ -1583,30 +1703,30 @@ export default class ChessRules {
         m.appear[0].p = this.pawnPromotions[0];
         for (let i=1; i<this.pawnPromotions.length; i++) {
           let newMv = JSON.parse(JSON.stringify(m));
-          newMv.appear[0].p = this.pawnSpecs.promotions[i];
+          newMv.appear[0].p = this.pawnPromotions[i];
           newMoves.push(newMv);
         }
       }
     });
-    Array.prototype.push.apply(moves, newMoves);
+    return moves.concat(newMoves);
   }
 
   // Generic method to find possible moves of "sliding or jumping" pieces
-  getPotentialMovesOf(piece, [x, y], color) {
+  getPotentialMovesOf(piece, [x, y]) {
     const color = this.getColor(x, y);
-    const specialAttack = !!this.getStepSpec(color, x, y).attack;
+    const stepSpec = this.getStepSpec(color, x, y, piece);
     let squares = [];
-    if (specialAttack) {
+    if (stepSpec.attack) {
       squares = this.findDestSquares(
         [x, y],
         {
           attackOnly: true,
-          segments: this.options["cylinder"]
+          stepSpec: stepSpec
         },
-        ([i, j]) => {
+        ([i1, j1], [i2, j2]) => {
           return (
-            (!this.options["zen"] || this.getPieceType(i, j) == 'k') &&
-            this.canTake([x, y], [i, j])
+            (!this.options["zen"] || this.isKing(i2, j2)) &&
+            this.canTake([i1, j1], [i2, j2])
           );
         }
       );
@@ -1614,44 +1734,44 @@ export default class ChessRules {
     const noSpecials = this.findDestSquares(
       [x, y],
       {
-        moveOnly: specialAttack || this.options["zen"],
-        segments: this.options["cylinder"]
-      },
-      ([i, j]) => this.board[i][j] == "" || this.canTake([x, y], [i, j])
+        moveOnly: !!stepSpec.attack || this.options["zen"],
+        stepSpec: stepSpec
+      }
     );
     Array.prototype.push.apply(squares, noSpecials);
     if (this.options["zen"]) {
       let zenCaptures = this.findCapturesOn(
         [x, y],
-        {},
-        ([i, j]) => this.getPieceType(i, j) != 'k'
+        {}, //byCol: default is ok
+        ([i1, j1], [i2, j2]) =>
+          !this.isKing(i1, j1) && this.canTake([i2, j2], [i1, j1])
       );
       // Technical step: segments (if any) are reversed
-      if (this.options["cylinder"]) {
-        zenCaptures.forEach(z => {
+      zenCaptures.forEach(z => {
+        if (!!z.segments)
           z.segments = z.segments.reverse().map(s => s.reverse())
-        });
-      }
+      });
       Array.prototype.push.apply(squares, zenCaptures);
     }
-    if (
-      this.options["recycle"] ||
-      (this.options["teleport"] && this.subTurnTeleport == 1)
-    ) {
+    if (this.hasSelfCaptures) {
       const selfCaptures = this.findDestSquares(
         [x, y],
         {
           attackOnly: true,
-          segments: this.options["cylinder"]
+          stepSpec: stepSpec
         },
-        ([i, j]) =>
-          this.getColor(i, j) == color && this.getPieceType(i, j) != 'k'
+        ([i1, j1], [i2, j2]) => {
+          return (
+            this.getColor(i2, j2) == color &&
+            this.canSelfTake([i1, j1], [i2, j2])
+          );
+        }
       );
       Array.prototype.push.apply(squares, selfCaptures);
     }
     return squares.map(s => {
       let mv = this.getBasicMove([x, y], s.sq);
-      if (this.options["cylinder"] && s.segments.length >= 2)
+      if (!!s.segments)
         mv.segments = s.segments;
       return mv;
     });
@@ -1659,45 +1779,39 @@ export default class ChessRules {
 
   findDestSquares([x, y], o, allowed) {
     if (!allowed)
-      allowed = () => true;
+      allowed = (sq1, sq2) => this.canTake(sq1, sq2);
     const apparentPiece = this.getPiece(x, y); //how it looks
     let res = [];
-    // Next 3 for Cylinder mode: (unused if !o.segments)
+    // Next 3 for Cylinder mode or circular (useless otherwise)
     let explored = {};
     let segments = [];
     let segStart = [];
     const addSquare = ([i, j]) => {
       let elt = {sq: [i, j]};
-      if (o.segments)
-        elt.segments = this.getSegments(segments, segStart, end);
+      if (segments.length >= 1)
+        elt.segments = this.getSegments(segments, segStart, [i, j]);
       res.push(elt);
     };
-    const exploreSteps = (stepArray) => {
+    const exploreSteps = (stepArray, mode) => {
       for (let s of stepArray) {
         outerLoop: for (let step of s.steps) {
-          if (o.segments) {
-            segments = [];
-            segStart = [x, y];
-          }
+          segments = [];
+          segStart = [x, y];
           let [i, j] = [x, y];
           let stepCounter = 0;
           while (
             this.onBoard(i, j) &&
             ((i == x && j == y) || this.canStepOver(i, j, apparentPiece))
           ) {
-            if (!explored[i + "." + j] && (i != x || j != y))
-            {
+            if (!explored[i + "." + j] && (i != x || j != y)) {
               explored[i + "." + j] = true;
               if (
-                allowed([i, j]) &&
-                (
-                  !o.captureTarget ||
-                  (o.captureTarget[0] == i && o.captureTarget[1] == j)
-                )
+                !o.captureTarget ||
+                (o.captureTarget[0] == i && o.captureTarget[1] == j)
               ) {
-                if (o.one && !o.attackOnly)
+                if (o.one && mode != "attack")
                   return true;
-                if (!o.attackOnly)
+                if (mode != "attack")
                   addSquare(!o.captureTarget ? [i, j] : [x, y]);
                 if (o.captureTarget)
                   return res[0];
@@ -1706,10 +1820,12 @@ export default class ChessRules {
             if (s.range <= stepCounter++)
               continue outerLoop;
             const oldIJ = [i, j];
-            i += step[0];
-            j = this.getY(j + step[1]);
-            if (o.segments && Math.abs(j - oldIJ[1]) > 1) {
-              // Boundary between segments (cylinder mode)
+            [i, j] = this.increment([i, j], step);
+            if (
+              Math.abs(i - oldIJ[0]) != Math.abs(step[0]) ||
+              Math.abs(j - oldIJ[1]) != Math.abs(step[1])
+            ) {
+              // Boundary between segments (cylinder or circular mode)
               segments.push([[segStart[0], segStart[1]], oldIJ]);
               segStart = [i, j];
             }
@@ -1719,10 +1835,10 @@ export default class ChessRules {
           const pieceIJ = this.getPieceType(i, j);
           if (!explored[i + "." + j]) {
             explored[i + "." + j] = true;
-            if (allowed([i, j])) {
-              if (o.one && !o.moveOnly)
+            if (allowed([x, y], [i, j])) {
+              if (o.one && mode != "moves")
                 return true;
-              if (!o.moveOnly)
+              if (mode != "moves")
                 addSquare(!o.captureTarget ? [i, j] : [x, y]);
               if (
                 o.captureTarget &&
@@ -1734,25 +1850,26 @@ export default class ChessRules {
           }
         }
       }
+      return undefined; //default, but let's explicit it
     };
     if (o.captureTarget)
-      exploreSteps(o.captureSteps)
+      return exploreSteps(o.captureSteps, "attack");
     else {
-      const stepSpec = this.getStepSpec(this.getColor(x, y), x, y);
-      if (!o.attackOnly || !stepSpec.attack)
-        exploreSteps(stepSpec.moves);
-      if (!o.moveOnly && !!stepSpec.attack)
-        exploreSteps(stepSpec.attack);
+      const stepSpec =
+        o.stepSpec || this.getStepSpec(this.getColor(x, y), x, y);
+      let outOne = false;
+      if (!o.attackOnly)
+        outOne = exploreSteps(stepSpec.both.concat(stepSpec.moves), "moves");
+      if (!outOne && !o.moveOnly)
+        outOne = exploreSteps(stepSpec.both.concat(stepSpec.attack), "attack");
+      return (o.one ? outOne : res);
     }
-    return o.captureTarget ? null : (o.one ? false : res);
   }
 
   // Search for enemy (or not) pieces attacking [x, y]
   findCapturesOn([x, y], o, allowed) {
-    if (!allowed)
-      allowed = () => true;
     if (!o.byCol)
-      o.byCol = [C.GetOppCol(this.getColor(x, y) || this.turn)];
+      o.byCol = this.getOppCols(this.getColor(x, y) || this.turn);
     let res = [];
     for (let i=0; i<this.size.x; i++) {
       for (let j=0; j<this.size.y; j++) {
@@ -1767,34 +1884,32 @@ export default class ChessRules {
           if (this.canStepOver(x, y, apparentPiece))
             continue;
           const stepSpec = this.getStepSpec(colIJ, i, j);
-          const attacks = stepSpec.attack || stepSpec.moves;
+          const attacks = stepSpec.attack.concat(stepSpec.both);
           for (let a of attacks) {
             for (let s of a.steps) {
               // Quick check: if step isn't compatible, don't even try
               if (!this.compatibleStep([i, j], [x, y], s, a.range))
                 continue;
               // Finally verify that nothing stand in-between
-              const newSquare = this.findDestSquares(
+              const out = this.findDestSquares(
                 [i, j],
                 {
                   captureTarget: [x, y],
                   captureSteps: [{steps: [s], range: a.range}],
-                  segments: this.options["cylinder"],
-                  attackOnly: true
                 },
-                ([ii, jj]) => this.canTake([ii, jj], [x, y])
+                allowed
               );
-              if (newSquare) {
+              if (out) {
                 if (o.one)
                   return true;
-                res.push(newSquare);
+                res.push(out);
               }
             }
           }
         }
       }
     }
-    return (one ? false : res);
+    return (o.one ? false : res);
   }
 
   // Build a regular move from its initial and destination squares.
@@ -1841,9 +1956,9 @@ export default class ChessRules {
         })
       );
       if (this.options["cannibal"] && destColor != initColor) {
-        const lastIdx = mv.vanish.length - 1;
+        const lastIdx = mv.vanish.length - 1; //think "Rifle+Cannibal"
         let trPiece = mv.vanish[lastIdx].p;
-        if (this.getPieceType(sx, sy) == 'k')
+        if (this.isKing(sx, sy))
           trPiece = C.CannibalKingCode[trPiece];
         if (mv.appear.length >= 1)
           mv.appear[0].p = trPiece;
@@ -1908,17 +2023,17 @@ export default class ChessRules {
   getEnpassantCaptures([x, y]) {
     const color = this.getColor(x, y);
     const shiftX = (color == 'w' ? -1 : 1);
-    const oppCol = C.GetOppCol(color);
+    const oppCols = this.getOppCols(color);
     if (
       this.epSquare &&
-      this.epSquare.x == x + shiftX &&
+      this.epSquare.x == x + shiftX && //NOTE: epSquare.x not on edge
       Math.abs(this.getY(this.epSquare.y - y)) == 1 &&
       // Doublemove (and Progressive?) guards:
       this.board[this.epSquare.x][this.epSquare.y] == "" &&
-      this.getColor(x, this.epSquare.y) == oppCol
+      oppCols.includes(this.getColor(x, this.epSquare.y))
     ) {
       const [epx, epy] = [this.epSquare.x, this.epSquare.y];
-      this.board[epx][epy] = oppCol + 'p';
+      this.board[epx][epy] = this.board[x][this.epSquare.y];
       let enpassantMove = this.getBasicMove([x, y], [epx, epy]);
       this.board[epx][epy] = "";
       const lastIdx = enpassantMove.vanish.length - 1; //think Rifle
@@ -1928,11 +2043,12 @@ export default class ChessRules {
     return [];
   }
 
-  getCastleMoves([x, y], finalSquares, castleWith) {
+  getCastleMoves([x, y], finalSquares, castleWith, castleFlags) {
     const c = this.getColor(x, y);
+    castleFlags = castleFlags || this.castleFlags[c];
 
     // Castling ?
-    const oppCol = C.GetOppCol(c);
+    const oppCols = this.getOppCols(c);
     let moves = [];
     // King, then rook:
     finalSquares =
@@ -1943,12 +2059,12 @@ export default class ChessRules {
       castleSide < 2;
       castleSide++ //large, then small
     ) {
-      if (this.castleFlags[c][castleSide] >= this.size.y)
+      if (castleFlags[castleSide] >= this.size.y)
         continue;
       // If this code is reached, rook and king are on initial position
 
       // NOTE: in some variants this is not a rook
-      const rookPos = this.castleFlags[c][castleSide];
+      const rookPos = castleFlags[castleSide];
       const castlingPiece = this.getPiece(x, rookPos);
       if (
         this.board[x][rookPos] == "" ||
@@ -1968,7 +2084,7 @@ export default class ChessRules {
           // will be executed in filterValid() later.
           (
             i != finalSquares[castleSide][0] &&
-            this.underCheck([x, i], oppCol)
+            this.underCheck([[x, i]], oppCols)
           )
           ||
           (
@@ -2038,75 +2154,98 @@ export default class ChessRules {
   ////////////////////
   // MOVES VALIDATION
 
-  // Is piece (or square) at given position attacked by "oppCol" ?
-  underAttack([x, y], oppCol) {
-    const king = this.getPieceType(x, y) == 'k';
+  // Is piece (or square) at given position attacked by "oppCol(s)" ?
+  underAttack([x, y], oppCols) {
+    // An empty square is considered as king,
+    // since it's used only in getCastleMoves (TODO?)
+    const king = this.board[x][y] == "" || this.isKing(x, y);
     return (
       (
         (!this.options["zen"] || king) &&
-        this.findCapturesOn([x, y],
-          {byCol: [oppCol], segments: this.options["cylinder"], one: true},
-          ([i, j]) => this.canTake([i, j], [x, y]))
+        this.findCapturesOn(
+          [x, y],
+          {
+            byCol: oppCols,
+            one: true
+          }
+        )
       )
       ||
       (
-        (this.options["zen"] && !king) &&
-        this.findDestSquares([x, y],
-          {attackOnly: true, segments: this.options["cylinder"], one: true},
-          ([i, j]) => this.canTake([i, j], [x, y]))
+        (!!this.options["zen"] && !king) &&
+        this.findDestSquares(
+          [x, y],
+          {
+            attackOnly: true,
+            one: true
+          },
+          ([i1, j1], [i2, j2]) => oppCols.includes(this.getColor(i2, j2))
+        )
       )
     );
   }
 
-  underCheck([x, y], oppCol) {
+  // Argument is (very generally) an array of squares (= arrays)
+  underCheck(square_s, oppCols) {
     if (this.options["taking"] || this.options["dark"])
       return false;
-    return this.underAttack([x, y], oppCol);
+    return square_s.some(sq => this.underAttack(sq, oppCols));
   }
 
-  // Stop at first king found (TODO: multi-kings)
+  // Scan board for king(s)
   searchKingPos(color) {
+    let res = [];
     for (let i=0; i < this.size.x; i++) {
       for (let j=0; j < this.size.y; j++) {
-        if (this.getColor(i, j) == color && this.getPieceType(i, j) == 'k')
-          return [i, j];
+        if (this.getColor(i, j) == color && this.isKing(i, j))
+          res.push([i, j]);
       }
     }
-    return [-1, -1]; //king not found
+    return res;
+  }
+
+  // cb: callback returning a boolean (false if king missing)
+  trackKingWrap(move, kingPos, cb) {
+    if (move.appear.length == 0 && move.vanish.length == 0)
+      return true;
+    const color =
+      (move.vanish.length > 0 ? move.vanish[0].c : move.appear[0].c);
+    let newKingPP = null,
+        sqIdx = 0,
+        res = true; //a priori valid
+    const oldKingPP =
+      move.vanish.find(v => this.isKing(0, 0, v.p) && v.c == color);
+    if (oldKingPP) {
+      // Search king in appear array:
+      newKingPP =
+        move.appear.find(a => this.isKing(0, 0, a.p) && a.c == color);
+      if (newKingPP) {
+        sqIdx = kingPos.findIndex(kp =>
+          kp[0] == oldKingPP.x && kp[1] == oldKingPP.y);
+        kingPos[sqIdx] = [newKingPP.x, newKingPP.y];
+      }
+      else
+        res = false; //king vanished
+    }
+    res &&= cb(kingPos);
+    if (oldKingPP && newKingPP)
+      kingPos[sqIdx] = [oldKingPP.x, oldKingPP.y];
+    return res;
   }
 
   // 'color' arg because some variants (e.g. Refusal) check opponent moves
   filterValid(moves, color) {
     if (!color)
       color = this.turn;
-    const oppCol = C.GetOppCol(color);
-    const kingPos = this.searchKingPos(color);
-    let filtered = {}; //avoid re-checking similar moves (promotions...)
+    const oppCols = this.getOppCols(color);
+    let kingPos = this.searchKingPos(color);
     return moves.filter(m => {
-      const key = m.start.x + m.start.y + '.' + m.end.x + m.end.y;
-      if (!filtered[key]) {
-        this.playOnBoard(m);
-        let square = kingPos,
-            res = true; //a priori valid
-        if (m.vanish.some(v => {
-          return this.getPieceType(0, 0, v.p) == 'k' && v.c == color;
-        })) {
-          // Search king in appear array:
-          const newKingIdx =
-            m.appear.findIndex(a => {
-              return this.getPieceType(0, 0, a.p) == 'k' && a.c == color;
-            });
-          if (newKingIdx >= 0)
-            square = [m.appear[newKingIdx].x, m.appear[newKingIdx].y];
-          else
-            res = false;
-        }
-        res &&= !this.underCheck(square, oppCol);
-        this.undoOnBoard(m);
-        filtered[key] = res;
-        return res;
-      }
-      return filtered[key];
+      this.playOnBoard(m);
+      const res = this.trackKingWrap(m, kingPos, (kp) => {
+        return !this.underCheck(kp, oppCols);
+      });
+      this.undoOnBoard(m);
+      return res;
     });
   }
 
@@ -2128,15 +2267,20 @@ export default class ChessRules {
       this.board[psq.x][psq.y] = psq.c + psq.p;
   }
 
-  updateCastleFlags(move) {
+  // NOTE: arg "castleFlags" for Coregal or Twokings
+  updateCastleFlags(move, castleFlags, king) {
+    castleFlags = castleFlags || this.castleFlags;
+    // If flags already off, no need to re-check:
+    if (
+      Object.values(castleFlags).every(cvals =>
+        cvals.every(val => val >= this.size.y))
+    ) {
+      return;
+    }
     // Update castling flags if start or arrive from/at rook/king locations
     move.appear.concat(move.vanish).forEach(psq => {
-      if (
-        this.board[psq.x][psq.y] != "" &&
-        this.getPieceType(psq.x, psq.y) == "k"
-      ) {
-        this.castleFlags[psq.c] = [this.size.y, this.size.y];
-      }
+      if ((king && psq.p == king) || (!king && this.isKing(0, 0, psq.p)))
+        castleFlags[psq.c] = [this.size.y, this.size.y];
       // NOTE: not "else if" because king can capture enemy rook...
       let c = "";
       if (psq.x == 0)
@@ -2144,28 +2288,17 @@ export default class ChessRules {
       else if (psq.x == this.size.x - 1)
         c = "w";
       if (c != "") {
-        const fidx = this.castleFlags[c].findIndex(f => f == psq.y);
+        const fidx = castleFlags[c].findIndex(f => f == psq.y);
         if (fidx >= 0)
-          this.castleFlags[c][fidx] = this.size.y;
+          castleFlags[c][fidx] = this.size.y;
       }
     });
   }
 
   prePlay(move) {
-    if (
-      this.hasCastle &&
-      // If flags already off, no need to re-check:
-      Object.values(this.castleFlags).some(cvals =>
-        cvals.some(val => val < this.size.y))
-    ) {
+    if (this.hasCastle)
       this.updateCastleFlags(move);
-    }
     if (this.options["crazyhouse"]) {
-      move.vanish.forEach(v => {
-        const square = C.CoordsToSquare({x: v.x, y: v.y});
-        if (this.ispawn[square])
-          delete this.ispawn[square];
-      });
       if (move.appear.length > 0 && move.vanish.length > 0) {
         // Assumption: something is moving
         const initSquare = C.CoordsToSquare(move.start);
@@ -2184,6 +2317,11 @@ export default class ChessRules {
           delete this.ispawn[destSquare];
         }
       }
+      move.vanish.forEach(v => {
+        const square = C.CoordsToSquare({x: v.x, y: v.y});
+        if (this.ispawn[square])
+          delete this.ispawn[square];
+      });
     }
     const minSize = Math.min(move.appear.length, move.vanish.length);
     if (
@@ -2221,16 +2359,16 @@ export default class ChessRules {
   }
 
   postPlay(move) {
-    const color = this.turn;
     if (this.options["dark"])
       this.updateEnlightened();
     if (this.options["teleport"]) {
       if (
         this.subTurnTeleport == 1 &&
-        move.vanish.length > move.appear.length &&
-        move.vanish[1].c == color
+        move.vanish.length == 2 &&
+        move.appear.length == 1 &&
+        move.vanish[1].c == this.turn
       ) {
-        const v = move.vanish[move.vanish.length - 1];
+        const v = move.vanish[1];
         this.captured = {x: v.x, y: v.y, c: v.c, p: v.p};
         this.subTurnTeleport = 2;
         return;
@@ -2238,8 +2376,12 @@ export default class ChessRules {
       this.subTurnTeleport = 1;
       this.captured = null;
     }
+    this.tryChangeTurn(move);
+  }
+
+  tryChangeTurn(move) {
     if (this.isLastMove(move)) {
-      this.turn = oppCol;
+      this.turn = C.GetOppTurn(this.turn);
       this.movesCount++;
       this.subTurn = 1;
     }
@@ -2251,14 +2393,14 @@ export default class ChessRules {
     if (move.next)
       return false;
     const color = this.turn;
-    const oppCol = C.GetOppCol(color);
-    const oppKingPos = this.searchKingPos(oppCol);
-    if (oppKingPos[0] < 0 || this.underCheck(oppKingPos, color))
+    const oppKingPos = this.searchKingPos(C.GetOppTurn(color));
+    if (oppKingPos.length == 0 || this.underCheck(oppKingPos, [color]))
       return true;
     return (
       (
         !this.options["balance"] ||
-        ![1, 3].includes(this.movesCount)
+        ![1, 2].includes(this.movesCount) ||
+        this.subTurn == 2
       )
       &&
       (
@@ -2276,13 +2418,12 @@ export default class ChessRules {
 
   // "Stop at the first move found"
   atLeastOneMove(color) {
-    color = color || this.turn;
     for (let i = 0; i < this.size.x; i++) {
       for (let j = 0; j < this.size.y; j++) {
         if (this.board[i][j] != "" && this.getColor(i, j) == color) {
           // NOTE: in fact searching for all potential moves from i,j.
           //       I don't believe this is an issue, for now at least.
-          const moves = this.getPotentialMovesFrom([i, j]);
+          const moves = this.getPotentialMovesFrom([i, j], color);
           if (moves.some(m => this.filterValid([m]).length >= 1))
             return true;
         }
@@ -2299,28 +2440,35 @@ export default class ChessRules {
   }
 
   // What is the score ? (Interesting if game is over)
-  getCurrentScore(move) {
-    const color = this.turn;
-    const oppCol = C.GetOppCol(color);
-    const kingPos = [this.searchKingPos(color), this.searchKingPos(oppCol)];
-    if (kingPos[0][0] < 0 && kingPos[1][0] < 0)
+  getCurrentScore(move_s) {
+    const move = move_s[move_s.length - 1];
+    // Shortcut in case the score was computed before:
+    if (move.result)
+      return move.result;
+    const oppTurn = C.GetOppTurn(this.turn);
+    const kingPos = {
+      w: this.searchKingPos('w'),
+      b: this.searchKingPos('b')
+    };
+    if (kingPos[this.turn].length == 0 && kingPos[oppTurn].length == 0)
       return "1/2";
-    if (kingPos[0][0] < 0)
-      return (color == "w" ? "0-1" : "1-0");
-    if (kingPos[1][0] < 0)
-      return (color == "w" ? "1-0" : "0-1");
-    if (this.atLeastOneMove())
+    if (kingPos[this.turn].length == 0)
+      return (this.turn == "w" ? "0-1" : "1-0");
+    if (kingPos[oppTurn].length == 0)
+      return (this.turn == "w" ? "1-0" : "0-1");
+    if (this.atLeastOneMove(this.turn))
       return "*";
     // No valid move: stalemate or checkmate?
-    if (!this.underCheck(kingPos[0], color))
+    if (!this.underCheck(kingPos[this.turn], this.getOppCols(this.turn)))
       return "1/2";
     // OK, checkmate
-    return (color == "w" ? "0-1" : "1-0");
+    return (this.turn == "w" ? "0-1" : "1-0");
   }
 
   playVisual(move, r) {
     move.vanish.forEach(v => {
-      this.g_pieces[v.x][v.y].remove();
+      if (this.g_pieces[v.x][v.y]) //can be null (e.g. Apocalypse)
+        this.g_pieces[v.x][v.y].remove();
       this.g_pieces[v.x][v.y] = null;
     });
     let chessboard =
@@ -2332,7 +2480,7 @@ export default class ChessRules {
       this.g_pieces[a.x][a.y] = document.createElement("piece");
       C.AddClass_es(this.g_pieces[a.x][a.y],
                     this.pieces(a.c, a.x, a.y)[a.p]["class"]);
-      this.g_pieces[a.x][a.y].classList.add(C.GetColorClass(a.c));
+      this.g_pieces[a.x][a.y].classList.add(V.GetColorClass(a.c));
       this.g_pieces[a.x][a.y].style.width = pieceWidth + "px";
       this.g_pieces[a.x][a.y].style.height = pieceWidth + "px";
       const [ip, jp] = this.getPixelPosition(a.x, a.y, r);
@@ -2351,32 +2499,37 @@ export default class ChessRules {
   buildMoveStack(move, r) {
     this.moveStack.push(move);
     this.computeNextMove(move);
-    this.play(move);
-    const newTurn = this.turn;
-    if (this.moveStack.length == 1)
-      this.playVisual(move, r);
-    if (move.next) {
-      this.gameState = {
-        fen: this.getFen(),
-        board: JSON.parse(JSON.stringify(this.board)) //easier
-      };
-      this.buildMoveStack(move.next, r);
-    }
-    else {
-      if (this.moveStack.length == 1) {
-        // Usual case (one normal move)
-        this.afterPlay(this.moveStack, newTurn, {send: true, res: true});
-        this.moveStack = []
+    const then = () => {
+      const newTurn = this.turn;
+      if (this.moveStack.length == 1 && !this.hideMoves)
+        this.playVisual(move, r);
+      if (move.next) {
+        this.gameState = {
+          fen: this.getFen(),
+          board: JSON.parse(JSON.stringify(this.board)) //easier
+        };
+        this.buildMoveStack(move.next, r);
       }
       else {
-        this.afterPlay(this.moveStack, newTurn, {send: true, res: false});
-        this.re_initFromFen(this.gameState.fen, this.gameState.board);
-        this.playReceivedMove(this.moveStack.slice(1), () => {
-          this.afterPlay(this.moveStack, newTurn, {send: false, res: true});
-          this.moveStack = []
-        });
+        if (this.moveStack.length == 1) {
+          // Usual case (one normal move)
+          this.afterPlay(this.moveStack, newTurn, {send: true, res: true});
+          this.moveStack = [];
+        }
+        else {
+          this.afterPlay(this.moveStack, newTurn, {send: true, res: false});
+          this.re_initFromFen(this.gameState.fen, this.gameState.board);
+          this.playReceivedMove(this.moveStack.slice(1), () => {
+            this.afterPlay(this.moveStack, newTurn, {send: false, res: true});
+            this.moveStack = [];
+          });
+        }
       }
-    }
+    };
+    // If hiding moves, then they are revealed in play() with callback
+    this.play(move, this.hideMoves ? then : null);
+    if (!this.hideMoves)
+      then();
   }
 
   // Implemented in variants using (automatic) moveStack
@@ -2384,6 +2537,10 @@ export default class ChessRules {
 
   animateMoving(start, end, drag, segments, cb) {
     let initPiece = this.getDomPiece(start.x, start.y);
+    if (!initPiece) { //TODO: shouldn't occur!
+      cb();
+      return;
+    }
     // NOTE: cloning often not required, but light enough, and simpler
     let movingPiece = initPiece.cloneNode();
     initPiece.style.opacity = "0";
@@ -2404,8 +2561,8 @@ export default class ChessRules {
       C.RemoveClass_es(movingPiece, pieces[startCode]["class"]);
       C.AddClass_es(movingPiece, pieces[drag.p]["class"]);
       if (apparentColor != drag.c) {
-        movingPiece.classList.remove(C.GetColorClass(apparentColor));
-        movingPiece.classList.add(C.GetColorClass(drag.c));
+        movingPiece.classList.remove(V.GetColorClass(apparentColor));
+        movingPiece.classList.add(V.GetColorClass(drag.c));
       }
     }
     container.appendChild(movingPiece);
@@ -2475,46 +2632,80 @@ export default class ChessRules {
         this.animateFading(arr, () => targetObj.increment());
       }
     }
+    targetObj.target +=
+      this.tryAnimateCastle(move, () => targetObj.increment());
     targetObj.target +=
       this.customAnimate(move, segments, () => targetObj.increment());
     if (targetObj.target == 0)
       callback();
   }
 
+  tryAnimateCastle(move, cb) {
+    if (
+      this.hasCastle &&
+      move.vanish.length == 2 &&
+      move.appear.length == 2 &&
+      this.isKing(0, 0, move.vanish[0].p) &&
+      this.isKing(0, 0, move.appear[0].p)
+    ) {
+      const start = {x: move.vanish[1].x, y: move.vanish[1].y},
+            end = {x: move.appear[1].x, y: move.appear[1].y};
+      const segments = [ [[start.x, start.y], [end.x, end.y]] ];
+      this.animateMoving(start, end, null, segments, cb);
+      return 1;
+    }
+    return 0;
+  }
+
   // Potential other animations (e.g. for Suction variant)
   customAnimate(move, segments, cb) {
     return 0; //nb of targets
   }
 
-  playReceivedMove(moves, callback) {
-    const launchAnimation = () => {
-      const r = container.querySelector(".chessboard").getBoundingClientRect();
-      const animateRec = i => {
-        this.animate(moves[i], () => {
-          this.play(moves[i]);
-          this.playVisual(moves[i], r);
-          if (i < moves.length - 1)
-            setTimeout(() => animateRec(i+1), 300);
-          else
-            callback();
-        });
-      };
-      animateRec(0);
+  launchAnimation(moves, container, callback) {
+    if (this.hideMoves) {
+      for (let i=0; i<moves.length; i++)
+        // If hiding moves, they are revealed into play():
+        this.play(moves[i], i == moves.length - 1 ? callback : () => {});
+      return;
+    }
+    const r = container.querySelector(".chessboard").getBoundingClientRect();
+    const animateRec = i => {
+      this.animate(moves[i], () => {
+        this.play(moves[i]);
+        this.playVisual(moves[i], r);
+        if (i < moves.length - 1)
+          setTimeout(() => animateRec(i+1), 300);
+        else
+          callback();
+      });
     };
+    animateRec(0);
+  }
+
+  playReceivedMove(moves, callback) {
     // Delay if user wasn't focused:
     const checkDisplayThenAnimate = (delay) => {
       if (container.style.display == "none") {
         alert("New move! Let's go back to game...");
         document.getElementById("gameInfos").style.display = "none";
         container.style.display = "block";
-        setTimeout(launchAnimation, 700);
+        setTimeout(
+          () => this.launchAnimation(moves, container, callback),
+          700
+        );
+      }
+      else {
+        setTimeout(
+          () => this.launchAnimation(moves, container, callback),
+          delay || 0
+        );
       }
-      else
-        setTimeout(launchAnimation, delay || 0);
     };
     let container = document.getElementById(this.containerId);
     if (document.hidden) {
       document.onvisibilitychange = () => {
+        // TODO here: page reload ?! (some issues if tab changed...)
         document.onvisibilitychange = undefined;
         checkDisplayThenAnimate(700);
       };