X-Git-Url: https://git.auder.net/?p=xogo.git;a=blobdiff_plain;f=base_rules.js;h=8ad0894e2972c074d8474844e15d52511fefc7d8;hp=eb01442da0132185abeeac5ed6b56c851c1707fe;hb=3b641716d7e86d9f1b39d1e046ce197e6b5a8075;hpb=21e8e7122487ae9417c5e7e72c25aa642b7a1226

diff --git a/base_rules.js b/base_rules.js
index eb01442..8ad0894 100644
--- a/base_rules.js
+++ b/base_rules.js
@@ -4,8 +4,13 @@ import PiPo from "/utils/PiPo.js";
 import Move from "/utils/Move.js";
 
 // NOTE: x coords: top to bottom (white perspective); y: left to right
+// NOTE: ChessRules is aliased as window.C, and variants as window.V
 export default class ChessRules {
 
+  static get Aliases() {
+    return {'C': ChessRules};
+  }
+
   /////////////////////////
   // VARIANT SPECIFICATIONS
 
@@ -14,22 +19,30 @@ export default class ChessRules {
   // Users can generally select a randomness level from 0 to 2.
   static get Options() {
     return {
-      // NOTE: some options are required for FEN generation, some aren't.
       select: [{
         label: "Randomness",
         variable: "randomness",
         defaut: 0,
         options: [
-          { label: "Deterministic", value: 0 },
-          { label: "Symmetric random", value: 1 },
-          { label: "Asymmetric random", value: 2 }
+          {label: "Deterministic", value: 0},
+          {label: "Symmetric random", value: 1},
+          {label: "Asymmetric random", value: 2}
         ]
       }],
-      check: [{
-        label: "Capture king?",
-        defaut: false,
-        variable: "taking"
-      }],
+      input: [
+        {
+          label: "Capture king",
+          variable: "taking",
+          type: "checkbox",
+          defaut: false
+        },
+        {
+          label: "Falling pawn",
+          variable: "pawnfall",
+          type: "checkbox",
+          defaut: false
+        }
+      ],
       // Game modifiers (using "elementary variants"). Default: false
       styles: [
         "atomic",
@@ -50,18 +63,8 @@ export default class ChessRules {
     };
   }
 
-  // Pawns specifications
-  get pawnSpecs() {
-    return {
-      directions: { 'w': -1, 'b': 1 },
-      initShift: { w: 1, b: 1 },
-      twoSquares: true,
-      threeSquares: false,
-      canCapture: true,
-      captureBackward: false,
-      bidirectional: false,
-      promotions: ['r', 'n', 'b', 'q']
-    };
+  get pawnPromotions() {
+    return ['q', 'r', 'n', 'b'];
   }
 
   // Some variants don't have flags:
@@ -84,30 +87,37 @@ export default class ChessRules {
       (!!this.options["recycle"] && !this.options["teleport"])
     );
   }
+  // Some variants do not store reserve state (Align4, Chakart...)
+  get hasReserveFen() {
+    return this.hasReserve;
+  }
 
   get noAnimate() {
     return !!this.options["dark"];
   }
 
   // Some variants use click infos:
-  doClick([x, y]) {
-    if (typeof x != "number") return null; //click on reserves
+  doClick(coords) {
+    if (typeof coords.x != "number")
+      return null; //click on reserves
     if (
-      this.options["teleport"] && this.subTurn == 2 &&
-      this.board[x][y] == ""
+      this.options["teleport"] && this.subTurnTeleport == 2 &&
+      this.board[coords.x][coords.y] == ""
     ) {
-      return new Move({
+      let res = new Move({
         start: {x: this.captured.x, y: this.captured.y},
         appear: [
           new PiPo({
-            x: x,
-            y: y,
+            x: coords.x,
+            y: coords.y,
             c: this.captured.c, //this.turn,
             p: this.captured.p
           })
         ],
         vanish: []
       });
+      res.drag = {c: this.captured.c, p: this.captured.p};
+      return res;
     }
     return null;
   }
@@ -115,52 +125,30 @@ export default class ChessRules {
   ////////////////////
   // COORDINATES UTILS
 
-  // 3 --> d (column number to letter)
-  static CoordToColumn(colnum) {
-    return String.fromCharCode(97 + colnum);
-  }
-
-  // d --> 3 (column letter to number)
-  static ColumnToCoord(columnStr) {
-    return columnStr.charCodeAt(0) - 97;
-  }
-
-  // 7 (numeric) --> 1 (str) [from black viewpoint].
-  static CoordToRow(rownum) {
-    return rownum;
-  }
-
-  // NOTE: wrong row index (1 should be 7 ...etc). But OK for the usage.
-  static RowToCoord(rownumStr) {
-    // NOTE: 30 is way more than enough (allow up to 29 rows on one character)
-    return parseInt(rownumStr, 30);
-  }
-
-  // a2 --> {x:2,y:0} (this is in fact a6)
+  // 3a --> {x:3, y:10}
   static SquareToCoords(sq) {
-    return {
-      x: ChessRules.RowToCoord(sq[1]),
-      // NOTE: column is always one char => max 26 columns
-      y: ChessRules.ColumnToCoord(sq[0])
-    };
+    return ArrayFun.toObject(["x", "y"],
+                             [0, 1].map(i => parseInt(sq[i], 36)));
   }
 
-  // {x:0,y:4} --> e0 (should be e8)
-  static CoordsToSquare(coords) {
-    return (
-      ChessRules.CoordToColumn(coords.y) + ChessRules.CoordToRow(coords.x)
-    );
+  // {x:11, y:12} --> bc
+  static CoordsToSquare(cd) {
+    return Object.values(cd).map(c => c.toString(36)).join("");
   }
 
-  coordsToId([x, y]) {
-    if (typeof x == "number")
-      return `${this.containerId}|sq-${x.toString(30)}-${y.toString(30)}`;
+  coordsToId(cd) {
+    if (typeof cd.x == "number") {
+      return (
+        `${this.containerId}|sq-${cd.x.toString(36)}-${cd.y.toString(36)}`
+      );
+    }
     // Reserve :
-    return `${this.containerId}|rsq-${x}-${y}`;
+    return `${this.containerId}|rsq-${cd.x}-${cd.y}`;
   }
 
   idToCoords(targetId) {
-    if (!targetId) return null; //outside page, maybe...
+    if (!targetId)
+      return null; //outside page, maybe...
     const idParts = targetId.split('|'); //prefix|sq-2-3 (start at 0 => 3,4)
     if (
       idParts.length < 2 ||
@@ -171,9 +159,9 @@ export default class ChessRules {
     }
     const squares = idParts[1].split('-');
     if (squares[0] == "sq")
-      return [ parseInt(squares[1], 30), parseInt(squares[2], 30) ];
-    // squares[0] == "rsq" : reserve, 'c' + 'p' (letters)
-    return [squares[1], squares[2]];
+      return {x: parseInt(squares[1], 36), y: parseInt(squares[2], 36)};
+    // squares[0] == "rsq" : reserve, 'c' + 'p' (letters color & piece)
+    return {x: squares[1], y: squares[2]};
   }
 
   /////////////
@@ -181,26 +169,25 @@ export default class ChessRules {
 
   // Turn "wb" into "B" (for FEN)
   board2fen(b) {
-    return b[0] == "w" ? b[1].toUpperCase() : b[1];
+    return (b[0] == "w" ? b[1].toUpperCase() : b[1]);
   }
 
   // Turn "p" into "bp" (for board)
   fen2board(f) {
-    return f.charCodeAt(0) <= 90 ? "w" + f.toLowerCase() : "b" + f;
+    return (f.charCodeAt(0) <= 90 ? "w" + f.toLowerCase() : "b" + f);
   }
 
   // Setup the initial random-or-not (asymmetric-or-not) position
   genRandInitFen(seed) {
-    Random.setSeed(seed);
-
     let fen, flags = "0707";
-    if (this.options.randomness == 0 || !this.options.randomness)
+    if (!this.options.randomness)
       // Deterministic:
       fen = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w 0";
 
     else {
       // Randomize
-      let pieces = { w: new Array(8), b: new Array(8) };
+      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"]) {
@@ -261,11 +248,16 @@ export default class ChessRules {
     }
     // Add turn + flags + enpassant (+ reserve)
     let parts = [];
-    if (this.hasFlags) parts.push(`"flags":"${flags}"`);
-    if (this.hasEnpassant) parts.push('"enpassant":"-"');
-    if (this.hasReserve) parts.push('"reserve":"000000000000"');
-    if (this.options["crazyhouse"]) parts.push('"ispawn":"-"');
-    if (parts.length >= 1) fen += " {" + parts.join(",") + "}";
+    if (this.hasFlags)
+      parts.push(`"flags":"${flags}"`);
+    if (this.hasEnpassant)
+      parts.push('"enpassant":"-"');
+    if (this.hasReserve)
+      parts.push('"reserve":"000000000000"');
+    if (this.options["crazyhouse"])
+      parts.push('"ispawn":"-"');
+    if (parts.length >= 1)
+      fen += " {" + parts.join(",") + "}";
     return fen;
   }
 
@@ -277,48 +269,56 @@ export default class ChessRules {
       turn: fenParts[1],
       movesCount: fenParts[2]
     };
-    if (fenParts.length > 3) res = Object.assign(res, JSON.parse(fenParts[3]));
+    if (fenParts.length > 3)
+      res = Object.assign(res, JSON.parse(fenParts[3]));
     return res;
   }
 
   // Return current fen (game state)
   getFen() {
     let fen = (
-      this.getBaseFen() + " " +
+      this.getPosition() + " " +
       this.getTurnFen() + " " +
       this.movesCount
     );
     let parts = [];
-    if (this.hasFlags) parts.push(`"flags":"${this.getFlagsFen()}"`);
+    if (this.hasFlags)
+      parts.push(`"flags":"${this.getFlagsFen()}"`);
     if (this.hasEnpassant)
       parts.push(`"enpassant":"${this.getEnpassantFen()}"`);
-    if (this.hasReserve) parts.push(`"reserve":"${this.getReserveFen()}"`);
+    if (this.hasReserveFen)
+      parts.push(`"reserve":"${this.getReserveFen()}"`);
     if (this.options["crazyhouse"])
       parts.push(`"ispawn":"${this.getIspawnFen()}"`);
-    if (parts.length >= 1) fen += " {" + parts.join(",") + "}";
+    if (parts.length >= 1)
+      fen += " {" + parts.join(",") + "}";
     return fen;
   }
 
+  static FenEmptySquares(count) {
+    // if more than 9 consecutive free spaces, break the integer,
+    // otherwise FEN parsing will fail.
+    if (count <= 9)
+      return count;
+    // Most boards of size < 18:
+    if (count <= 18)
+      return "9" + (count - 9);
+    // Except Gomoku:
+    return "99" + (count - 18);
+  }
+
   // Position part of the FEN string
-  getBaseFen() {
-    const format = (count) => {
-      // if more than 9 consecutive free spaces, break the integer,
-      // otherwise FEN parsing will fail.
-      if (count <= 9) return count;
-      // Most boards of size < 18:
-      if (count <= 18) return "9" + (count - 9);
-      // Except Gomoku:
-      return "99" + (count - 18);
-    };
+  getPosition() {
     let position = "";
     for (let i = 0; i < this.size.y; i++) {
       let emptyCount = 0;
       for (let j = 0; j < this.size.x; j++) {
-        if (this.board[i][j] == "") emptyCount++;
+        if (this.board[i][j] == "")
+          emptyCount++;
         else {
           if (emptyCount > 0) {
             // Add empty squares in-between
-            position += format(emptyCount);
+            position += C.FenEmptySquares(emptyCount);
             emptyCount = 0;
           }
           position += this.board2fen(this.board[i][j]);
@@ -326,8 +326,9 @@ export default class ChessRules {
       }
       if (emptyCount > 0)
         // "Flush remainder"
-        position += format(emptyCount);
-      if (i < this.size.y - 1) position += "/"; //separate rows
+        position += C.FenEmptySquares(emptyCount);
+      if (i < this.size.y - 1)
+        position += "/"; //separate rows
     }
     return position;
   }
@@ -339,14 +340,15 @@ export default class ChessRules {
   // Flags part of the FEN string
   getFlagsFen() {
     return ["w", "b"].map(c => {
-      return this.castleFlags[c].map(x => x.toString(30)).join("");
+      return this.castleFlags[c].map(x => x.toString(36)).join("");
     }).join("");
   }
 
   // Enpassant part of the FEN string
   getEnpassantFen() {
-    if (!this.epSquare) return "-"; //no en-passant
-    return ChessRules.CoordsToSquare(this.epSquare);
+    if (!this.epSquare)
+      return "-"; //no en-passant
+    return C.CoordsToSquare(this.epSquare);
   }
 
   getReserveFen() {
@@ -356,30 +358,39 @@ export default class ChessRules {
   }
 
   getIspawnFen() {
-    const coords = Object.keys(this.ispawn);
-    if (coords.length == 0) return "-";
-    return coords.map(ChessRules.CoordsToSquare).join(",");
+    const squares = Object.keys(this.ispawn);
+    if (squares.length == 0)
+      return "-";
+    return squares.join(",");
   }
 
   // Set flags from fen (castle: white a,h then black a,h)
   setFlags(fenflags) {
     this.castleFlags = {
-      w: [0, 1].map(i => parseInt(fenflags.charAt(i), 30)),
-      b: [2, 3].map(i => parseInt(fenflags.charAt(i), 30))
+      w: [0, 1].map(i => parseInt(fenflags.charAt(i), 36)),
+      b: [2, 3].map(i => parseInt(fenflags.charAt(i), 36))
     };
   }
 
   //////////////////
   // INITIALIZATION
 
-  // Fen string fully describes the game state
   constructor(o) {
     this.options = o.options;
+    // Fill missing options (always the case if random challenge)
+    (V.Options.select || []).concat(V.Options.input || []).forEach(opt => {
+      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;
     this.playerColor = o.color;
-    this.afterPlay = o.afterPlay;
+    this.afterPlay = o.afterPlay; //trigger some actions after playing a move
 
-    // FEN-related:
-    if (!o.fen) o.fen = this.genRandInitFen(o.seed);
+    // Fen string fully describes the game state
+    if (!o.fen)
+      o.fen = this.genRandInitFen(o.seed);
     const fenParsed = this.parseFen(o.fen);
     this.board = this.getBoard(fenParsed.position);
     this.turn = fenParsed.turn;
@@ -401,9 +412,11 @@ export default class ChessRules {
         const character = rows[i][indexInRow];
         const num = parseInt(character, 10);
         // If num is a number, just shift j:
-        if (!isNaN(num)) j += num;
+        if (!isNaN(num))
+          j += num;
         // Else: something at position i,j
-        else board[i][j++] = this.fen2board(character);
+        else
+          board[i][j++] = this.fen2board(character);
       }
     }
     return board;
@@ -412,123 +425,82 @@ export default class ChessRules {
   // Some additional variables from FEN (variant dependant)
   setOtherVariables(fenParsed) {
     // Set flags and enpassant:
-    if (this.hasFlags) this.setFlags(fenParsed.flags);
+    if (this.hasFlags)
+      this.setFlags(fenParsed.flags);
     if (this.hasEnpassant)
       this.epSquare = this.getEpSquare(fenParsed.enpassant);
-    if (this.hasReserve) this.initReserves(fenParsed.reserve);
-    if (this.options["crazyhouse"]) this.initIspawn(fenParsed.ispawn);
+    if (this.hasReserve)
+      this.initReserves(fenParsed.reserve);
+    if (this.options["crazyhouse"])
+      this.initIspawn(fenParsed.ispawn);
     this.subTurn = 1; //may be unused
-    if (this.options["teleport"]) this.captured = null;
+    if (this.options["teleport"]) {
+      this.subTurnTeleport = 1;
+      this.captured = null;
+    }
     if (this.options["dark"]) {
-      this.enlightened = ArrayFun.init(this.size.x, this.size.y);
       // Setup enlightened: squares reachable by player side
-      this.updateEnlightened(false);
+      this.enlightened = ArrayFun.init(this.size.x, this.size.y, false);
+      this.updateEnlightened();
     }
   }
 
-  updateEnlightened(withGraphics) {
-    let newEnlightened = ArrayFun.init(this.size.x, this.size.y, false);
-    const pawnShift = { w: -1, b: 1 };
+  updateEnlightened() {
+    this.oldEnlightened = this.enlightened;
+    this.enlightened = ArrayFun.init(this.size.x, this.size.y, false);
     // Add pieces positions + all squares reachable by moves (includes Zen):
-    // (watch out special pawns case)
     for (let x=0; x<this.size.x; x++) {
       for (let y=0; y<this.size.y; y++) {
         if (this.board[x][y] != "" && this.getColor(x, y) == this.playerColor)
         {
-          newEnlightened[x][y] = true;
-          const piece = this.getPiece(x, y);
-          if (piece == ChessRules.PAWN) {
-            // Attacking squares wouldn't be highlighted if no captures:
-            this.pieces(this.playerColor)[piece].attack.forEach(step => {
-              const [i, j] = [x + step[0], this.computeY(y + step[1])];
-              if (this.onBoard(i, j) && this.board[i][j] == "")
-                newEnlightened[i][j] = true;
-            });
-          }
+          this.enlightened[x][y] = true;
           this.getPotentialMovesFrom([x, y]).forEach(m => {
-            newEnlightened[m.end.x][m.end.y] = true;
+            this.enlightened[m.end.x][m.end.y] = true;
           });
         }
       }
     }
-    if (this.epSquare) this.enlightEnpassant(newEnlightened);
-    if (withGraphics) this.graphUpdateEnlightened(newEnlightened);
-    this.enlightened = newEnlightened;
+    if (this.epSquare)
+      this.enlightEnpassant();
   }
 
-  // Include en-passant capturing square if any:
-  enlightEnpassant(newEnlightened) {
-    const steps = this.pieces(this.playerColor)[ChessRules.PAWN].attack;
+  // 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;
     for (let step of steps) {
       const x = this.epSquare.x - step[0],
-            y = this.computeY(this.epSquare.y - step[1]);
+            y = this.getY(this.epSquare.y - step[1]);
       if (
         this.onBoard(x, y) &&
         this.getColor(x, y) == this.playerColor &&
-        this.getPiece(x, y) == ChessRules.PAWN
+        this.getPieceType(x, y) == "p"
       ) {
-        newEnlightened[x][this.epSquare.y] = true;
+        this.enlightened[x][this.epSquare.y] = true;
         break;
       }
     }
   }
 
-  // Apply diff this.enlightened --> newEnlightened on board
-  graphUpdateEnlightened(newEnlightened) {
-    let container = document.getElementById(this.containerId);
-    const r = container.getBoundingClientRect();
-    const pieceWidth = this.getPieceWidth(r.width);
-    for (let x=0; x<this.size.x; x++) {
-      for (let y=0; y<this.size.y; y++) {
-        if (this.enlightened[x][y] && !newEnlightened[x][y]) {
-          let elt = document.getElementById(this.coordsToId([x, y]));
-          elt.style.fillOpacity = "0.5";
-          if (this.g_pieces[x][y]) {
-            this.g_pieces[x][y].remove();
-            this.g_pieces[x][y] = null;
-          }
-        }
-        else if (!this.enlightened[x][y] && newEnlightened[x][y]) {
-          let elt = document.getElementById(this.coordsToId([x, y]));
-          elt.style.fillOpacity = "1";
-          if (this.board[x][y] != "") {
-            const piece = this.getPiece(x, y);
-            const color = this.getColor(x, y);
-            this.g_pieces[x][y] = document.createElement("piece");
-            let newClasses = [
-              this.pieces()[piece]["class"],
-              color == "w" ? "white" : "black"
-            ];
-            newClasses.forEach(cl => this.g_pieces[x][y].classList.add(cl));
-            this.g_pieces[x][y].style.width = pieceWidth + "px";
-            this.g_pieces[x][y].style.height = pieceWidth + "px";
-            const [ip, jp] = this.getPixelPosition(x, y, r);
-            this.g_pieces[x][y].style.transform =
-              `translate(${ip}px,${jp}px)`;
-            container.appendChild(this.g_pieces[x][y]);
-          }
-        }
-      }
-    }
-  }
-
-  // ordering p,r,n,b,q,k (most general + count in base 30 if needed)
+  // ordering as in pieces() p,r,n,b,q,k (+ count in base 30 if needed)
   initReserves(reserveStr) {
     const counts = reserveStr.split("").map(c => parseInt(c, 30));
     this.reserve = { w: {}, b: {} };
-    const pieceName = Object.keys(this.pieces());
-    for (let i of ArrayFun.range(12)) {
-      if (i < 6) this.reserve['w'][pieceName[i]] = counts[i];
-      else this.reserve['b'][pieceName[i-6]] = counts[i];
+    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];
     }
   }
 
   initIspawn(ispawnStr) {
-    if (ispawnStr != "-") {
-      this.ispawn = ispawnStr.split(",").map(ChessRules.SquareToCoords)
-                    .reduce((o, key) => ({ ...o, [key]: true}), {});
-    }
-    else this.ispawn = {};
+    if (ispawnStr != "-")
+      this.ispawn = ArrayFun.toObject(ispawnStr.split(","), true);
+    else
+      this.ispawn = {};
   }
 
   getNbReservePieces(color) {
@@ -538,6 +510,14 @@ export default class ChessRules {
     );
   }
 
+  getRankInReserve(c, p) {
+    const pieces = Object.keys(this.pieces());
+    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);
+  }
+
   //////////////
   // VISUAL PART
 
@@ -545,12 +525,8 @@ export default class ChessRules {
     return (rwidth / this.size.y);
   }
 
-  getSquareWidth(rwidth) {
-    return this.getPieceWidth(rwidth);
-  }
-
   getReserveSquareSize(rwidth, nbR) {
-    const sqSize = this.getSquareWidth(rwidth);
+    const sqSize = this.getPieceWidth(rwidth);
     return Math.min(sqSize, rwidth / nbR);
   }
 
@@ -558,51 +534,67 @@ export default class ChessRules {
     return `${this.containerId}|rnum-${color}${piece}`;
   }
 
+  static AddClass_es(piece, class_es) {
+    if (!Array.isArray(class_es))
+      class_es = [class_es];
+    class_es.forEach(cl => {
+      piece.classList.add(cl);
+    });
+  }
+
+  static RemoveClass_es(piece, class_es) {
+    if (!Array.isArray(class_es))
+      class_es = [class_es];
+    class_es.forEach(cl => {
+      piece.classList.remove(cl);
+    });
+  }
+
   graphicalInit() {
     // NOTE: not window.onresize = this.re_drawBoardElts because scope (this)
     window.onresize = () => this.re_drawBoardElements();
     this.re_drawBoardElements();
     this.initMouseEvents();
-    const container = document.getElementById(this.containerId);
-    new ResizeObserver(this.rescale).observe(container);
+    const chessboard =
+      document.getElementById(this.containerId).querySelector(".chessboard");
   }
 
   re_drawBoardElements() {
     const board = this.getSvgChessboard();
-    const oppCol = ChessRules.GetOppCol(this.playerColor);
-    let container = document.getElementById(this.containerId);
-    container.innerHTML = "";
-    container.insertAdjacentHTML('beforeend', board);
-    let cb = container.querySelector("#" + this.containerId + "_SVG");
-    const aspectRatio = this.size.y / this.size.x;
+    const oppCol = C.GetOppCol(this.playerColor);
+    let chessboard =
+      document.getElementById(this.containerId).querySelector(".chessboard");
+    chessboard.innerHTML = "";
+    chessboard.insertAdjacentHTML('beforeend', board);
     // Compare window ratio width / height to aspectRatio:
     const windowRatio = window.innerWidth / window.innerHeight;
     let cbWidth, cbHeight;
-    if (windowRatio <= aspectRatio) {
+    if (windowRatio <= this.size.ratio) {
       // Limiting dimension is width:
       cbWidth = Math.min(window.innerWidth, 767);
-      cbHeight = cbWidth / aspectRatio;
+      cbHeight = cbWidth / this.size.ratio;
     }
     else {
       // Limiting dimension is height:
       cbHeight = Math.min(window.innerHeight, 767);
-      cbWidth = cbHeight * aspectRatio;
+      cbWidth = cbHeight * this.size.ratio;
     }
-    if (this.reserve) {
+    if (this.hasReserve) {
       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);
-        cbWidth = cbHeight * aspectRatio;
+        cbWidth = cbHeight * this.size.ratio;
       }
     }
-    container.style.width = cbWidth + "px";
-    container.style.height = cbHeight + "px";
+    chessboard.style.width = cbWidth + "px";
+    chessboard.style.height = cbHeight + "px";
     // Center chessboard:
     const spaceLeft = (window.innerWidth - cbWidth) / 2,
           spaceTop = (window.innerHeight - cbHeight) / 2;
-    container.style.left = spaceLeft + "px";
-    container.style.top = spaceTop + "px";
+    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({
@@ -615,39 +607,37 @@ export default class ChessRules {
 
   // Get SVG board (background, no pieces)
   getSvgChessboard() {
-    const [sizeX, sizeY] = [this.size.x, this.size.y];
     const flipped = (this.playerColor == 'b');
     let board = `
       <svg
         viewBox="0 0 80 80"
-        version="1.1"
-        id="${this.containerId}_SVG">
-      <g>`;
-    for (let i=0; i < sizeX; i++) {
-      for (let j=0; j < sizeY; j++) {
+        class="chessboard_SVG">`;
+    for (let i=0; i < this.size.x; i++) {
+      for (let j=0; j < this.size.y; j++) {
         const ii = (flipped ? this.size.x - 1 - i : i);
         const jj = (flipped ? this.size.y - 1 - j : j);
-        let fillOpacity = '1';
-        if (this.options["dark"] && !this.enlightened[ii][jj])
-          fillOpacity = '0.5';
+        let classes = this.getSquareColorClass(ii, jj);
+        if (this.enlightened && !this.enlightened[ii][jj])
+          classes += " in-shadow";
         // NOTE: x / y reversed because coordinates system is reversed.
-        // TODO: CSS "wood" style, rect --> style --> background-image ?
-        board += `<rect style="fill-opacity:${fillOpacity};
-                               fill:#${this.getSquareColor(ii, jj)}"
-          id="${this.coordsToId([ii, jj])}"
-          width="10"
-          height="10"
-          x="${10*j}"
-          y="${10*i}" />`;
+        board += `
+          <rect
+            class="${classes}"
+            id="${this.coordsToId({x: ii, y: jj})}"
+            width="10"
+            height="10"
+            x="${10*j}"
+            y="${10*i}"
+          />`;
       }
     }
-    board += "</g></svg>";
+    board += "</svg>";
     return board;
   }
 
-  // Generally light square bottom-right; TODO: user-defined colors at least
-  getSquareColor(i, j) {
-    return ((i+j) % 2 == 0 ? "f0d9b5": "b58863");
+  // Generally light square bottom-right
+  getSquareColorClass(x, y) {
+    return ((x+y) % 2 == 0 ? "light-square": "dark-square");
   }
 
   setupPieces(r) {
@@ -662,60 +652,64 @@ export default class ChessRules {
         }
       }
     }
-    else this.g_pieces = ArrayFun.init(this.size.x, this.size.y, null);
-    let container = document.getElementById(this.containerId);
-    if (!r) r = container.getBoundingClientRect();
+    else
+      this.g_pieces = ArrayFun.init(this.size.x, this.size.y, null);
+    let chessboard =
+      document.getElementById(this.containerId).querySelector(".chessboard");
+    if (!r)
+      r = chessboard.getBoundingClientRect();
     const pieceWidth = this.getPieceWidth(r.width);
     for (let i=0; i < this.size.x; i++) {
       for (let j=0; j < this.size.y; j++) {
-        if (
-          this.board[i][j] != "" &&
-          (!this.options["dark"] || this.enlightened[i][j])
-        ) {
-          const piece = this.getPiece(i, 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");
-          this.g_pieces[i][j].classList.add(this.pieces()[piece]["class"]);
-          this.g_pieces[i][j].classList.add(color == "w" ? "white" : "black");
+          C.AddClass_es(this.g_pieces[i][j], this.pieces()[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";
-          const [ip, jp] = this.getPixelPosition(i, j, r);
-          this.g_pieces[i][j].style.transform = `translate(${ip}px,${jp}px)`;
-          container.appendChild(this.g_pieces[i][j]);
+          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)`;
+          if (this.enlightened && !this.enlightened[i][j])
+            this.g_pieces[i][j].classList.add("hidden");
+          chessboard.appendChild(this.g_pieces[i][j]);
         }
       }
     }
-    if (this.reserve) this.re_drawReserve(['w', 'b'], r);
+    if (this.hasReserve)
+      this.re_drawReserve(['w', 'b'], r);
   }
 
-  // NOTE: assume !!this.reserve
+  // NOTE: assume this.reserve != null
   re_drawReserve(colors, r) {
     if (this.r_pieces) {
       // Remove (old) reserve pieces
       for (let c of colors) {
-        if (!this.reserve[c]) continue;
-        Object.keys(this.reserve[c]).forEach(p => {
-          if (this.r_pieces[c][p]) {
-            this.r_pieces[c][p].remove();
-            delete this.r_pieces[c][p];
-            const numId = this.getReserveNumId(c, p);
-            document.getElementById(numId).remove();
-          }
+        Object.keys(this.r_pieces[c]).forEach(p => {
+          this.r_pieces[c][p].remove();
+          delete this.r_pieces[c][p];
+          const numId = this.getReserveNumId(c, p);
+          document.getElementById(numId).remove();
         });
-        let reservesDiv = document.getElementById("reserves_" + c);
-        if (reservesDiv) reservesDiv.remove();
       }
     }
-    else this.r_pieces = { 'w': {}, 'b': {} };
-    if (!r) {
-      const container = document.getElementById(this.containerId);
-      r = container.getBoundingClientRect();
-    }
-    const epsilon = 1e-4; //fix display bug on Firefox at least
+    else
+      this.r_pieces = { w: {}, b: {} };
+    let container = document.getElementById(this.containerId);
+    if (!r)
+      r = container.querySelector(".chessboard").getBoundingClientRect();
     for (let c of colors) {
-      if (!this.reserve[c]) continue;
+      let reservesDiv = document.getElementById("reserves_" + c);
+      if (reservesDiv)
+        reservesDiv.remove();
+      if (!this.reserve[c])
+        continue;
       const nbR = this.getNbReservePieces(c);
-      if (nbR == 0) continue;
+      if (nbR == 0)
+        continue;
       const sqResSize = this.getReserveSquareSize(r.width, nbR);
       let ridx = 0;
       const vShift = (c == this.playerColor ? r.height + 5 : -sqResSize - 5);
@@ -725,21 +719,22 @@ export default class ChessRules {
       rcontainer.classList.add("reserves");
       rcontainer.style.left = i0 + "px";
       rcontainer.style.top = j0 + "px";
-      rcontainer.style.width = (nbR * sqResSize) + "px";
+      // NOTE: +1 fix display bug on Firefox at least
+      rcontainer.style.width = (nbR * sqResSize + 1) + "px";
       rcontainer.style.height = sqResSize + "px";
-      document.getElementById("boardContainer").appendChild(rcontainer);
+      container.appendChild(rcontainer);
       for (let p of Object.keys(this.reserve[c])) {
-        if (this.reserve[c][p] == 0) continue;
+        if (this.reserve[c][p] == 0)
+          continue;
         let r_cell = document.createElement("div");
-        r_cell.id = this.coordsToId([c, p]);
+        r_cell.id = this.coordsToId({x: c, y: p});
         r_cell.classList.add("reserve-cell");
-        r_cell.style.width = (sqResSize - epsilon) + "px";
-        r_cell.style.height = (sqResSize - epsilon) + "px";
+        r_cell.style.width = sqResSize + "px";
+        r_cell.style.height = sqResSize + "px";
         rcontainer.appendChild(r_cell);
         let piece = document.createElement("piece");
-        const pieceSpec = this.pieces(c)[p];
-        piece.classList.add(pieceSpec["class"]);
-        piece.classList.add(c == 'w' ? "white" : "black");
+        C.AddClass_es(piece, this.pieces()[p]["class"]);
+        piece.classList.add(C.GetColorClass(c));
         piece.style.width = "100%";
         piece.style.height = "100%";
         this.r_pieces[c][p] = piece;
@@ -758,59 +753,95 @@ export default class ChessRules {
   }
 
   updateReserve(color, piece, count) {
+    if (this.options["cannibal"] && C.CannibalKings[piece])
+      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)) this.re_drawReserve([color]);
+    if ([oldCount, count].includes(0))
+      this.re_drawReserve([color]);
     else {
       const numId = this.getReserveNumId(color, piece);
       document.getElementById(numId).textContent = count;
     }
   }
 
-  // After resize event: no need to destroy/recreate pieces
-  rescale() {
-    let container = document.getElementById(this.containerId);
-    if (!container) return; //useful at initial loading
-    const r = container.getBoundingClientRect();
-    const newRatio = r.width / r.height;
-    const aspectRatio = this.size.y / this.size.x;
-    let newWidth = r.width,
-        newHeight = r.height;
-    if (newRatio > aspectRatio) {
-      newWidth = r.height * aspectRatio;
-      container.style.width = newWidth + "px";
-    }
-    else if (newRatio < aspectRatio) {
-      newHeight = r.width / aspectRatio;
-      container.style.height = newHeight + "px";
+  // Apply diff this.enlightened --> oldEnlightened on board
+  graphUpdateEnlightened() {
+    let chessboard =
+      document.getElementById(this.containerId).querySelector(".chessboard");
+    const r = chessboard.getBoundingClientRect();
+    const pieceWidth = this.getPieceWidth(r.width);
+    for (let x=0; x<this.size.x; x++) {
+      for (let y=0; y<this.size.y; y++) {
+        if (!this.enlightened[x][y] && this.oldEnlightened[x][y]) {
+          let elt = document.getElementById(this.coordsToId({x: x, y: y}));
+          elt.classList.add("in-shadow");
+          if (this.g_pieces[x][y])
+            this.g_pieces[x][y].classList.add("hidden");
+        }
+        else if (this.enlightened[x][y] && !this.oldEnlightened[x][y]) {
+          let elt = document.getElementById(this.coordsToId({x: x, y: y}));
+          elt.classList.remove("in-shadow");
+          if (this.g_pieces[x][y])
+            this.g_pieces[x][y].classList.remove("hidden");
+        }
+      }
     }
+  }
+
+  // Resize board: no need to destroy/recreate pieces
+  rescale(mode) {
+    let chessboard =
+      document.getElementById(this.containerId).querySelector(".chessboard");
+    const r = chessboard.getBoundingClientRect();
+    const multFact = (mode == "up" ? 1.05 : 0.95);
+    let [newWidth, newHeight] = [multFact * r.width, multFact * r.height];
+    // Stay in window:
+    if (newWidth > window.innerWidth) {
+      newWidth = window.innerWidth;
+      newHeight = newWidth / this.size.ratio;
+    }
+    if (newHeight > window.innerHeight) {
+      newHeight = window.innerHeight;
+      newWidth = newHeight * this.size.ratio;
+    }
+    chessboard.style.width = newWidth + "px";
+    chessboard.style.height = newHeight + "px";
     const newX = (window.innerWidth - newWidth) / 2;
-    container.style.left = newX + "px";
+    chessboard.style.left = newX + "px";
     const newY = (window.innerHeight - newHeight) / 2;
-    container.style.top = newY + "px";
-    const newR = { x: newX, y: newY, width: newWidth, height: newHeight };
+    chessboard.style.top = newY + "px";
+    const newR = {x: newX, y: newY, width: newWidth, height: newHeight};
     const pieceWidth = this.getPieceWidth(newWidth);
-    for (let i=0; i < this.size.x; i++) {
-      for (let j=0; j < this.size.y; j++) {
-        if (this.board[i][j] != "") {
-          // NOTE: could also use CSS transform "scale"
-          this.g_pieces[i][j].style.width = pieceWidth + "px";
-          this.g_pieces[i][j].style.height = pieceWidth + "px";
-          const [ip, jp] = this.getPixelPosition(i, j, newR);
-          this.g_pieces[i][j].style.transform = `translate(${ip}px,${jp}px)`;
+    // NOTE: next "if" for variants which use squares filling
+    // instead of "physical", moving pieces
+    if (this.g_pieces) {
+      for (let i=0; i < this.size.x; i++) {
+        for (let j=0; j < this.size.y; j++) {
+          if (this.g_pieces[i][j]) {
+            // NOTE: could also use CSS transform "scale"
+            this.g_pieces[i][j].style.width = pieceWidth + "px";
+            this.g_pieces[i][j].style.height = pieceWidth + "px";
+            const [ip, jp] = this.getPixelPosition(i, j, newR);
+            // Translate coordinates to use chessboard as reference:
+            this.g_pieces[i][j].style.transform =
+              `translate(${ip - newX}px,${jp - newY}px)`;
+          }
         }
       }
     }
-    if (this.reserve) this.rescaleReserve(newR);
+    if (this.hasReserve)
+      this.rescaleReserve(newR);
   }
 
   rescaleReserve(r) {
-    const epsilon = 1e-4;
     for (let c of ['w','b']) {
-      if (!this.reserve[c]) continue;
+      if (!this.reserve[c])
+        continue;
       const nbR = this.getNbReservePieces(c);
-      if (nbR == 0) continue;
+      if (nbR == 0)
+        continue;
       // Resize container first
       const sqResSize = this.getReserveSquareSize(r.width, nbR);
       const vShift = (c == this.playerColor ? r.height + 5 : -sqResSize - 5);
@@ -818,15 +849,16 @@ export default class ChessRules {
       let rcontainer = document.getElementById("reserves_" + c);
       rcontainer.style.left = i0 + "px";
       rcontainer.style.top = j0 + "px";
-      rcontainer.style.width = (nbR * sqResSize) + "px";
+      rcontainer.style.width = (nbR * sqResSize + 1) + "px";
       rcontainer.style.height = sqResSize + "px";
       // And then reserve cells:
       const rpieceWidth = this.getReserveSquareSize(r.width, nbR);
       Object.keys(this.reserve[c]).forEach(p => {
-        if (this.reserve[c][p] == 0) return;
-        let r_cell = document.getElementById(this.coordsToId([c, p]));
-        r_cell.style.width = (sqResSize - epsilon) + "px";
-        r_cell.style.height = (sqResSize - epsilon) + "px";
+        if (this.reserve[c][p] == 0)
+          return;
+        let r_cell = document.getElementById(this.coordsToId({x: c, y: p}));
+        r_cell.style.width = sqResSize + "px";
+        r_cell.style.height = sqResSize + "px";
       });
     }
   }
@@ -835,19 +867,33 @@ export default class ChessRules {
   // Our coordinate system differs from CSS one (x <--> y).
   // We return here the CSS coordinates (more useful).
   getPixelPosition(i, j, r) {
-    const sqSize = this.getSquareWidth(r.width);
-    if (i < 0 || j < 0) return [0, 0]; //piece vanishes
-    const flipped = (this.playerColor == 'b');
-    const x = (flipped ? this.size.y - 1 - j : j) * sqSize;
-    const y = (flipped ? this.size.x - 1 - i : i) * sqSize;
-    return [x, y];
+    if (i < 0 || j < 0)
+      return [0, 0]; //piece vanishes
+    let x, y;
+    if (typeof i == "string") {
+      // Reserves: need to know the rank of piece
+      const nbR = this.getNbReservePieces(i);
+      const rsqSize = this.getReserveSquareSize(r.width, nbR);
+      x = this.getRankInReserve(i, j) * rsqSize;
+      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;
+      y = (flipped ? this.size.x - 1 - i : i) * sqSize;
+    }
+    return [r.x + x, r.y + y];
   }
 
   initMouseEvents() {
     let container = document.getElementById(this.containerId);
+    let chessboard = container.querySelector(".chessboard");
 
     const getOffset = e => {
-      if (e.clientX) return {x: e.clientX, y: e.clientY}; //Mouse
+      if (e.clientX)
+        // Mouse
+        return {x: e.clientX, y: e.clientY};
       let touchLocation = null;
       if (e.targetTouches && e.targetTouches.length >= 1)
         // Touch screen, dragstart
@@ -856,12 +902,12 @@ export default class ChessRules {
         // Touch screen, dragend
         touchLocation = e.changedTouches[0];
       if (touchLocation)
-        return {x: touchLocation.pageX, y: touchLocation.pageY};
-      return [0, 0]; //Big trouble here =)
+        return {x: touchLocation.clientX, y: touchLocation.clientY};
+      return {x: 0, y: 0}; //shouldn't reach here =)
     }
 
     const centerOnCursor = (piece, e) => {
-      const centerShift = sqSize / 2;
+      const centerShift = this.getPieceWidth(r.width) / 2;
       const offset = getOffset(e);
       piece.style.left = (offset.x - centerShift) + "px";
       piece.style.top = (offset.y - centerShift) + "px";
@@ -870,30 +916,36 @@ export default class ChessRules {
     let start = null,
         r = null,
         startPiece, curPiece = null,
-        sqSize;
+        pieceWidth;
     const mousedown = (e) => {
-      r = container.getBoundingClientRect();
-      sqSize = this.getSquareWidth(r.width);
-      const square = this.idToCoords(e.target.id);
-      if (square) {
-        const [i, j] = square;
-        const move = this.doClick([i, j]);
-        if (move) this.playPlusVisual(move);
+      // Disable zoom on smartphones:
+      if (e.touches && e.touches.length > 1)
+        e.preventDefault();
+      r = chessboard.getBoundingClientRect();
+      pieceWidth = this.getPieceWidth(r.width);
+      const cd = this.idToCoords(e.target.id);
+      if (cd) {
+        const move = this.doClick(cd);
+        if (move)
+          this.playPlusVisual(move);
         else {
-          if (typeof i != "number") startPiece = this.r_pieces[i][j];
-          else if (this.g_pieces[i][j]) startPiece = this.g_pieces[i][j];
-          if (startPiece && this.canIplay(i, j)) {
+          const [x, y] = Object.values(cd);
+          if (typeof x != "number")
+            startPiece = this.r_pieces[x][y];
+          else
+            startPiece = this.g_pieces[x][y];
+          if (startPiece && this.canIplay(x, y)) {
             e.preventDefault();
-            start = { x: i, y: j };
+            start = cd;
             curPiece = startPiece.cloneNode();
             curPiece.style.transform = "none";
             curPiece.style.zIndex = 5;
-            curPiece.style.width = sqSize + "px";
-            curPiece.style.height = sqSize + "px";
+            curPiece.style.width = pieceWidth + "px";
+            curPiece.style.height = pieceWidth + "px";
             centerOnCursor(curPiece, e);
-            document.getElementById("boardContainer").appendChild(curPiece);
+            container.appendChild(curPiece);
             startPiece.style.opacity = "0.4";
-            container.style.cursor = "none";
+            chessboard.style.cursor = "none";
           }
         }
       }
@@ -904,31 +956,32 @@ export default class ChessRules {
         e.preventDefault();
         centerOnCursor(curPiece, e);
       }
+      else if (e.changedTouches && e.changedTouches.length >= 1)
+        // Attempt to prevent horizontal swipe...
+        e.preventDefault();
     };
 
     const mouseup = (e) => {
-      const newR = container.getBoundingClientRect();
-      if (newR.width != r.width || newR.height != r.height) {
-        this.rescale();
+      if (!start)
         return;
-      }
-      if (!start) return;
       const [x, y] = [start.x, start.y];
       start = null;
       e.preventDefault();
-      container.style.cursor = "pointer";
+      chessboard.style.cursor = "pointer";
       startPiece.style.opacity = "1";
       const offset = getOffset(e);
       const landingElt = document.elementFromPoint(offset.x, offset.y);
-      const sq = this.idToCoords(landingElt.id);
-      if (sq) {
-        const [i, j] = sq;
+      const cd =
+        (landingElt ? this.idToCoords(landingElt.id) : undefined);
+      if (cd) {
         // NOTE: clearly suboptimal, but much easier, and not a big deal.
         const potentialMoves = this.getPotentialMovesFrom([x, y])
-          .filter(m => m.end.x == i && m.end.y == j);
+          .filter(m => m.end.x == cd.x && m.end.y == cd.y);
         const moves = this.filterValid(potentialMoves);
-        if (moves.length >= 2) this.showChoices(moves, r);
-        else if (moves.length == 1) this.playPlusVisual(moves[0], r);
+        if (moves.length >= 2)
+          this.showChoices(moves, r);
+        else if (moves.length == 1)
+          this.playPlusVisual(moves[0], r);
       }
       curPiece.remove();
     };
@@ -937,32 +990,36 @@ export default class ChessRules {
       document.addEventListener("mousedown", mousedown);
       document.addEventListener("mousemove", mousemove);
       document.addEventListener("mouseup", mouseup);
+      document.addEventListener("wheel",
+        (e) => this.rescale(e.deltaY < 0 ? "up" : "down"));
     }
     if ('ontouchstart' in window) {
-      document.addEventListener("touchstart", mousedown);
-      document.addEventListener("touchmove", mousemove);
-      document.addEventListener("touchend", mouseup);
+      // https://stackoverflow.com/a/42509310/12660887
+      document.addEventListener("touchstart", mousedown, {passive: false});
+      document.addEventListener("touchmove", mousemove, {passive: false});
+      document.addEventListener("touchend", mouseup, {passive: false});
     }
+    // TODO: onpointerdown/move/up ? See reveal.js /controllers/touch.js
   }
 
   showChoices(moves, r) {
     let container = document.getElementById(this.containerId);
+    let chessboard = container.querySelector(".chessboard");
     let choices = document.createElement("div");
     choices.id = "choices";
     choices.style.width = r.width + "px";
     choices.style.height = r.height + "px";
     choices.style.left = r.x + "px";
     choices.style.top = r.y + "px";
-    container.style.opacity = "0.5";
-    let boardContainer = document.getElementById("boardContainer");
-    boardContainer.appendChild(choices);
-    const squareWidth = this.getSquareWidth(r.width);
+    chessboard.style.opacity = "0.5";
+    container.appendChild(choices);
+    const squareWidth = r.width / this.size.y;
     const firstUpLeft = (r.width - (moves.length * squareWidth)) / 2;
     const firstUpTop = (r.height - squareWidth) / 2;
     const color = moves[0].appear[0].c;
     const callback = (m) => {
-      container.style.opacity = "1";
-      boardContainer.removeChild(choices);
+      chessboard.style.opacity = "1";
+      container.removeChild(choices);
       this.playPlusVisual(m, r);
     }
     for (let i=0; i < moves.length; i++) {
@@ -975,9 +1032,9 @@ export default class ChessRules {
       choice.style.backgroundColor = "lightyellow";
       choice.onclick = () => callback(moves[i]);
       const piece = document.createElement("piece");
-      const pieceSpec = this.pieces(color)[moves[i].appear[0].p];
-      piece.classList.add(pieceSpec["class"]);
-      piece.classList.add(color == 'w' ? "white" : "black");
+      const cdisp = moves[i].choice || moves[i].appear[0].p;
+      C.AddClass_es(piece, this.pieces()[cdisp]["class"]);
+      piece.classList.add(C.GetColorClass(color));
       piece.style.width = "100%";
       piece.style.height = "100%";
       choice.appendChild(piece);
@@ -989,149 +1046,188 @@ export default class ChessRules {
   // BASIC UTILS
 
   get size() {
-    return { "x": 8, "y": 8 };
+    return {
+      x: 8,
+      y: 8,
+      ratio: 1 //for rectangular board = y / x
+    };
   }
 
   // Color of thing on square (i,j). 'undefined' if square is empty
   getColor(i, j) {
+    if (typeof i == "string")
+      return i; //reserves
     return this.board[i][j].charAt(0);
   }
 
-  // Piece type on square (i,j). 'undefined' if square is empty
+  static GetColorClass(c) {
+    if (c == 'w')
+      return "white";
+    if (c == 'b')
+      return "black";
+    return "other-color"; //unidentified color
+  }
+
+  // Assume square i,j isn't empty
   getPiece(i, j) {
+    if (typeof j == "string")
+      return j; //reserves
     return this.board[i][j].charAt(1);
   }
 
+  // Piece type on square (i,j)
+  getPieceType(i, j) {
+    const p = this.getPiece(i, j);
+    return C.CannibalKings[p] || p; //a cannibal king move as...
+  }
+
   // Get opponent color
   static GetOppCol(color) {
     return (color == "w" ? "b" : "w");
   }
 
-  // Can thing on square1 take thing on square2
+  // Can thing on square1 capture (no return) thing on square2?
   canTake([x1, y1], [x2, y2]) {
-    return (
-      (
-        (this.options["recycle"] || this.options["teleport"]) &&
-        this.getPiece(x2, y2) != ChessRules.KING
-      ) ||
-      (this.getColor(x1, y1) !== this.getColor(x2, y2))
-    );
+    return (this.getColor(x1, y1) !== this.getColor(x2, y2));
   }
 
   // Is (x,y) on the chessboard?
   onBoard(x, y) {
-    return x >= 0 && x < this.size.x && y >= 0 && y < this.size.y;
+    return (x >= 0 && x < this.size.x &&
+            y >= 0 && y < this.size.y);
   }
 
-  // Used in interface: 'side' arg == player color
+  // Am I allowed to move thing at square x,y ?
   canIplay(x, y) {
-    return (
-      this.playerColor == this.turn &&
-      (
-        (typeof x == "number" && this.getColor(x, y) == this.turn) ||
-        (typeof x == "string" && x == this.turn) //reserve
-      )
-    );
+    return (this.playerColor == this.turn && this.getColor(x, y) == this.turn);
   }
 
   ////////////////////////
   // PIECES SPECIFICATIONS
 
-  pieces(color) {
+  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));
     return {
       'p': {
         "class": "pawn",
-        steps: [[pawnShift, 0]],
-        range: 1,
-        attack: [[pawnShift, 1], [pawnShift, -1]]
+        moves: [
+          {
+            steps: [[pawnShift, 0]],
+            range: (initRank ? 2 : 1)
+          }
+        ],
+        attack: [
+          {
+            steps: [[pawnShift, 1], [pawnShift, -1]],
+            range: 1
+          }
+        ]
       },
       // rook
       'r': {
         "class": "rook",
-        steps: [[0, 1], [0, -1], [1, 0], [-1, 0]]
+        moves: [
+          {steps: [[0, 1], [0, -1], [1, 0], [-1, 0]]}
+        ]
       },
       // knight
       'n': {
         "class": "knight",
-        steps: [
-          [1, 2], [1, -2], [-1, 2], [-1, -2],
-          [2, 1], [-2, 1], [2, -1], [-2, -1]
-        ],
-        range: 1
+        moves: [
+          {
+            steps: [
+              [1, 2], [1, -2], [-1, 2], [-1, -2],
+              [2, 1], [-2, 1], [2, -1], [-2, -1]
+            ],
+            range: 1
+          }
+        ]
       },
       // bishop
       'b': {
         "class": "bishop",
-        steps: [[1, 1], [1, -1], [-1, 1], [-1, -1]]
+        moves: [
+          {steps: [[1, 1], [1, -1], [-1, 1], [-1, -1]]}
+        ]
       },
       // queen
       'q': {
         "class": "queen",
-        steps: [
-          [0, 1], [0, -1], [1, 0], [-1, 0],
-          [1, 1], [1, -1], [-1, 1], [-1, -1]
+        moves: [
+          {
+            steps: [
+              [0, 1], [0, -1], [1, 0], [-1, 0],
+              [1, 1], [1, -1], [-1, 1], [-1, -1]
+            ]
+          }
         ]
       },
       // king
       'k': {
         "class": "king",
-        steps: [
-          [0, 1], [0, -1], [1, 0], [-1, 0],
-          [1, 1], [1, -1], [-1, 1], [-1, -1]
-        ],
-        range: 1
-      }
+        moves: [
+          {
+            steps: [
+              [0, 1], [0, -1], [1, 0], [-1, 0],
+              [1, 1], [1, -1], [-1, 1], [-1, -1]
+            ],
+            range: 1
+          }
+        ]
+      },
+      // Cannibal kings:
+      '!': {"class": "king-pawn", moveas: "p"},
+      '#': {"class": "king-rook", moveas: "r"},
+      '$': {"class": "king-knight", moveas: "n"},
+      '%': {"class": "king-bishop", moveas: "b"},
+      '*': {"class": "king-queen", moveas: "q"}
     };
   }
 
-  // Some pieces codes (for a clearer code)
-  static get PAWN() {
-    return "p";
-  }
-  static get QUEEN() {
-    return "q";
-  }
-  static get KING() {
-    return "k";
-  }
-
   ////////////////////
   // MOVES GENERATION
 
   // For Cylinder: get Y coordinate
-  computeY(y) {
-    if (!this.options["cylinder"]) return y;
+  getY(y) {
+    if (!this.options["cylinder"])
+      return y;
     let res = y % this.size.y;
-    if (res < 0) res += this.size.y;
+    if (res < 0)
+      res += this.size.y;
     return res;
   }
 
   // Stop at the first capture found
   atLeastOneCapture(color) {
     color = color || this.turn;
-    const oppCol = ChessRules.GetOppCol(color);
+    const oppCol = C.GetOppCol(color);
     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) {
-          const specs = this.pieces(color)[this.getPiece(i, j)];
-          const steps = specs.attack || specs.steps;
-          outerLoop: for (let step of steps) {
-            let [ii, jj] = [i + step[0], this.computeY(j + step[1])];
-            let stepCounter = 1;
-            while (this.onBoard(ii, jj) && this.board[ii][jj] == "") {
-              if (specs.range <= stepCounter++) continue outerLoop;
-              ii += step[0];
-              jj = this.computeY(jj + step[1]);
-            }
-            if (
-              this.onBoard(ii, jj) &&
-              this.getColor(ii, jj) == oppCol &&
-              this.filterValid(
-                [this.getBasicMove([i, j], [ii, jj])]
-              ).length >= 1
-            ) {
-              return true;
+          const allSpecs = this.pieces(color, i, j)
+          let specs = allSpecs[this.getPieceType(i, j)];
+          const attacks = specs.attack || specs.moves;
+          for (let a of attacks) {
+            outerLoop: for (let step of a.steps) {
+              let [ii, jj] = [i + step[0], this.getY(j + step[1])];
+              let stepCounter = 1;
+              while (this.onBoard(ii, jj) && this.board[ii][jj] == "") {
+                if (a.range <= stepCounter++)
+                  continue outerLoop;
+                ii += step[0];
+                jj = this.getY(jj + step[1]);
+              }
+              if (
+                this.onBoard(ii, jj) &&
+                this.getColor(ii, jj) == oppCol &&
+                this.filterValid(
+                  [this.getBasicMove([i, j], [ii, jj])]
+                ).length >= 1
+              ) {
+                return true;
+              }
             }
           }
         }
@@ -1142,17 +1238,17 @@ export default class ChessRules {
 
   getDropMovesFrom([c, p]) {
     // NOTE: by design, this.reserve[c][p] >= 1 on user click
-    // (but not necessarily otherwise)
-    if (!this.reserve[c][p] || this.reserve[c][p] == 0) return [];
+    // (but not necessarily otherwise: atLeastOneMove() etc)
+    if (this.reserve[c][p] == 0)
+      return [];
     let moves = [];
     for (let i=0; i<this.size.x; i++) {
       for (let j=0; j<this.size.y; j++) {
-        // TODO: rather simplify this "if" and add post-condition: more general
         if (
           this.board[i][j] == "" &&
-          (!this.options["dark"] || this.enlightened[i][j]) &&
+          (!this.enlightened || this.enlightened[i][j]) &&
           (
-            p != ChessRules.PAWN ||
+            p != "p" ||
             (c == 'w' && i < this.size.x - 1) ||
             (c == 'b' && i > 0)
           )
@@ -1172,15 +1268,24 @@ export default class ChessRules {
   }
 
   // All possible moves from selected square
-  getPotentialMovesFrom(sq) {
-    if (typeof sq[0] == "string") return this.getDropMovesFrom(sq);
-    if (this.options["madrasi"] && this.isImmobilized(sq)) return [];
-    const piece = this.getPiece(sq[0], sq[1]);
-    let moves;
-    if (piece == ChessRules.PAWN) moves = this.getPotentialPawnMoves(sq);
-    else moves = this.getPotentialMovesOf(piece, sq);
+  getPotentialMovesFrom(sq, color) {
+    if (this.subTurnTeleport == 2)
+      return [];
+    if (typeof sq[0] == "string")
+      return this.getDropMovesFrom(sq);
+    if (this.isImmobilized(sq))
+      return [];
+    const piece = this.getPieceType(sq[0], sq[1]);
+    let moves = this.getPotentialMovesOf(piece, sq);
     if (
-      piece == ChessRules.KING &&
+      piece == "p" &&
+      this.hasEnpassant &&
+      this.epSquare
+    ) {
+      Array.prototype.push.apply(moves, this.getEnpassantCaptures(sq));
+    }
+    if (
+      piece == "k" &&
       this.hasCastle &&
       this.castleFlags[color || this.turn].some(v => v < this.size.y)
     ) {
@@ -1190,175 +1295,381 @@ export default class ChessRules {
   }
 
   postProcessPotentialMoves(moves) {
-    if (moves.length == 0) return [];
+    if (moves.length == 0)
+      return [];
     const color = this.getColor(moves[0].start.x, moves[0].start.y);
-    const oppCol = ChessRules.GetOppCol(color);
+    const oppCol = C.GetOppCol(color);
 
-    if (this.options["capture"] && this.atLeastOneCapture()) {
-      // Filter out non-capturing moves (not using m.vanish because of
-      // self captures of Recycle and Teleport).
-      moves = moves.filter(m => {
-        return (
-          this.board[m.end.x][m.end.y] != "" &&
-          this.getColor(m.end.x, m.end.y) == oppCol
-        );
-      });
+    if (this.options["capture"] && this.atLeastOneCapture())
+      moves = this.capturePostProcess(moves, oppCol);
+
+    if (this.options["atomic"])
+      this.atomicPostProcess(moves, oppCol);
+
+    if (
+      moves.length > 0 &&
+      this.getPieceType(moves[0].start.x, moves[0].start.y) == "p"
+    ) {
+      this.pawnPostProcess(moves, color, oppCol);
     }
 
-    if (this.options["atomic"]) {
-      moves.forEach(m => {
-        if (
-          this.board[m.end.x][m.end.y] != "" &&
-          this.getColor(m.end.x, m.end.y) == oppCol
-        ) {
-          // Explosion!
-          let steps = [
-            [-1, -1],
-            [-1, 0],
-            [-1, 1],
-            [0, -1],
-            [0, 1],
-            [1, -1],
-            [1, 0],
-            [1, 1]
-          ];
-          for (let step of steps) {
-            let x = m.end.x + step[0];
-            let y = this.computeY(m.end.y + step[1]);
-            if (
-              this.onBoard(x, y) &&
-              this.board[x][y] != "" &&
-              this.getPiece(x, y) != ChessRules.PAWN
-            ) {
-              m.vanish.push(
-                new PiPo({
-                  p: this.getPiece(x, y),
-                  c: this.getColor(x, y),
-                  x: x,
-                  y: y
-                })
-              );
-            }
-          }
-          if (!this.options["rifle"]) m.appear.pop(); //nothin appears
-        }
-      });
+    if (
+      this.options["cannibal"] &&
+      this.options["rifle"]
+    ) {
+      // In this case a rifle-capture from last rank may promote a pawn
+      this.riflePromotePostProcess(moves, color);
     }
+
     return moves;
   }
 
+  capturePostProcess(moves, oppCol) {
+    // 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
+      );
+    });
+  }
+
+  atomicPostProcess(moves, oppCol) {
+    moves.forEach(m => {
+      if (
+        this.board[m.end.x][m.end.y] != "" &&
+        this.getColor(m.end.x, m.end.y) == oppCol
+      ) {
+        // Explosion!
+        let steps = [
+          [-1, -1],
+          [-1, 0],
+          [-1, 1],
+          [0, -1],
+          [0, 1],
+          [1, -1],
+          [1, 0],
+          [1, 1]
+        ];
+        for (let step of steps) {
+          let x = m.end.x + step[0];
+          let y = this.getY(m.end.y + step[1]);
+          if (
+            this.onBoard(x, y) &&
+            this.board[x][y] != "" &&
+            this.getPieceType(x, y) != "p"
+          ) {
+            m.vanish.push(
+              new PiPo({
+                p: this.getPiece(x, y),
+                c: this.getColor(x, y),
+                x: x,
+                y: y
+              })
+            );
+          }
+        }
+        if (!this.options["rifle"])
+          m.appear.pop(); //nothing appears
+      }
+    });
+  }
+
+  pawnPostProcess(moves, color, oppCol) {
+    let moreMoves = [];
+    const lastRank = (color == "w" ? 0 : this.size.x - 1);
+    const initPiece = this.getPiece(moves[0].start.x, moves[0].start.y);
+    moves.forEach(m => {
+      const [x1, y1] = [m.start.x, m.start.y];
+      const [x2, y2] = [m.end.x, m.end.y];
+      const promotionOk = (
+        x2 == lastRank &&
+        (!this.options["rifle"] || this.board[x2][y2] == "")
+      );
+      if (!promotionOk)
+        return; //nothing to do
+      if (this.options["pawnfall"]) {
+        m.appear.shift();
+        return;
+      }
+      let finalPieces = ["p"];
+      if (
+        this.options["cannibal"] &&
+        this.board[x2][y2] != "" &&
+        this.getColor(x2, y2) == oppCol
+      ) {
+        finalPieces = [this.getPieceType(x2, y2)];
+      }
+      else
+        finalPieces = this.pawnPromotions;
+      m.appear[0].p = finalPieces[0];
+      if (initPiece == "!") //cannibal king-pawn
+        m.appear[0].p = C.CannibalKingCode[finalPieces[0]];
+      for (let i=1; i<finalPieces.length; i++) {
+        const piece = finalPieces[i];
+        const tr = {
+          c: color,
+          p: (initPiece != "!" ? piece : C.CannibalKingCode[piece])
+        };
+        let newMove = this.getBasicMove([x1, y1], [x2, y2], tr);
+        moreMoves.push(newMove);
+      }
+    });
+    Array.prototype.push.apply(moves, moreMoves);
+  }
+
+  riflePromotePostProcess(moves, color) {
+    const lastRank = (color == "w" ? 0 : this.size.x - 1);
+    let newMoves = [];
+    moves.forEach(m => {
+      if (
+        m.start.x == lastRank &&
+        m.appear.length >= 1 &&
+        m.appear[0].p == "p" &&
+        m.appear[0].x == m.start.x &&
+        m.appear[0].y == m.start.y
+      ) {
+        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];
+          newMoves.push(newMv);
+        }
+      }
+    });
+    Array.prototype.push.apply(moves, newMoves);
+  }
+
+  // NOTE: using special symbols to not interfere with variants' pieces codes
+  static get CannibalKings() {
+    return {
+      "!": "p",
+      "#": "r",
+      "$": "n",
+      "%": "b",
+      "*": "q",
+      "k": "k"
+    };
+  }
+
+  static get CannibalKingCode() {
+    return {
+      "p": "!",
+      "r": "#",
+      "n": "$",
+      "b": "%",
+      "q": "*",
+      "k": "k"
+    };
+  }
+
+  isKing(symbol) {
+    return !!C.CannibalKings[symbol];
+  }
+
   // For Madrasi:
   // (redefined in Baroque etc, where Madrasi condition doesn't make sense)
   isImmobilized([x, y]) {
+    if (!this.options["madrasi"])
+      return false;
     const color = this.getColor(x, y);
-    const oppCol = ChessRules.GetOppCol(color);
-    const piece = this.getPiece(x, y);
-    const stepSpec = this.pieces(color)[piece];
-    let [steps, range] = [stepSpec.attack || stepSpec.steps, stepSpec.range];
-    outerLoop: for (let step of steps) {
-      let [i, j] = [x + step[0], y + step[1]];
-      let stepCounter = 1;
-      while (this.onBoard(i, j) && this.board[i][j] == "") {
-        if (range <= stepCounter++) continue outerLoop;
-        i += step[0];
-        j = this.computeY(j + step[1]);
-      }
-      if (
-        this.onBoard(i, j) &&
-        this.getColor(i, j) == oppCol &&
-        this.getPiece(i, j) == piece
-      ) {
-        return true;
+    const oppCol = C.GetOppCol(color);
+    const piece = this.getPieceType(x, y); //ok not cannibal king
+    const stepSpec = this.pieces(color, x, y)[piece];
+    const attacks = stepSpec.attack || stepSpec.moves;
+    for (let a of attacks) {
+      outerLoop: for (let step of a.steps) {
+        let [i, j] = [x + step[0], y + step[1]];
+        let stepCounter = 1;
+        while (this.onBoard(i, j) && this.board[i][j] == "") {
+          if (a.range <= stepCounter++)
+            continue outerLoop;
+          i += step[0];
+          j = this.getY(j + step[1]);
+        }
+        if (
+          this.onBoard(i, j) &&
+          this.getColor(i, j) == oppCol &&
+          this.getPieceType(i, j) == piece
+        ) {
+          return true;
+        }
       }
     }
     return false;
   }
 
+  canStepOver(i, j) {
+    // In some variants, objects on boards don't stop movement (Chakart)
+    return this.board[i][j] == "";
+  }
+
   // Generic method to find possible moves of "sliding or jumping" pieces
   getPotentialMovesOf(piece, [x, y]) {
     const color = this.getColor(x, y);
-    const stepSpec = this.pieces(color)[piece];
-    let [steps, range] = [stepSpec.steps, stepSpec.range];
+    const stepSpec = this.pieces(color, x, y)[piece];
     let moves = [];
-    let explored = {}; //for Cylinder mode
-    outerLoop: for (let step of steps) {
-      let [i, j] = [x + step[0], this.computeY(y + step[1])];
-      let stepCounter = 1;
-      while (
-        this.onBoard(i, j) &&
-        this.board[i][j] == "" &&
-        !explored[i + "." + j]
-      ) {
-        explored[i + "." + j] = true;
-        moves.push(this.getBasicMove([x, y], [i, j]));
-        if (range <= stepCounter++) continue outerLoop;
-        i += step[0];
-        j = this.computeY(j + step[1]);
+    // Next 3 for Cylinder mode:
+    let explored = {};
+    let segments = [];
+    let segStart = [];
+
+    const addMove = (start, end) => {
+      let newMove = this.getBasicMove(start, end);
+      if (segments.length > 0) {
+        newMove.segments = JSON.parse(JSON.stringify(segments));
+        newMove.segments.push([[segStart[0], segStart[1]], [end[0], end[1]]]);
       }
-      if (
-        this.onBoard(i, j) &&
-        (
-          !this.options["zen"] ||
-          this.getPiece(i, j) == ChessRules.KING ||
-          this.getColor(i, j) == color //OK for Recycle and Teleport
-        ) &&
-        this.canTake([x, y], [i, j]) &&
-        !explored[i + "." + j]
-      ) {
-        explored[i + "." + j] = true;
-        moves.push(this.getBasicMove([x, y], [i, j]));
+      moves.push(newMove);
+    };
+
+    const findAddMoves = (type, stepArray) => {
+      for (let s of stepArray) {
+        outerLoop: for (let step of s.steps) {
+          segments = [];
+          segStart = [x, y];
+          let [i, j] = [x, y];
+          let stepCounter = 0;
+          while (
+            this.onBoard(i, j) &&
+            (this.canStepOver(i, j) || (i == x && j == y))
+          ) {
+            if (
+              type != "attack" &&
+              !explored[i + "." + j] &&
+              (i != x || j != y)
+            ) {
+              explored[i + "." + j] = true;
+              addMove([x, y], [i, j]);
+            }
+            if (s.range <= stepCounter++)
+              continue outerLoop;
+            const oldIJ = [i, j];
+            i += step[0];
+            j = this.getY(j + step[1]);
+            if (Math.abs(j - oldIJ[1]) > 1) {
+              // Boundary between segments (cylinder mode)
+              segments.push([[segStart[0], segStart[1]], oldIJ]);
+              segStart = [i, j];
+            }
+          }
+          if (!this.onBoard(i, j))
+            continue;
+          const pieceIJ = this.getPieceType(i, j);
+          if (
+            type != "moveonly" &&
+            !explored[i + "." + j] &&
+            (
+              !this.options["zen"] ||
+              pieceIJ == "k"
+            ) &&
+            (
+              this.canTake([x, y], [i, j]) ||
+              (
+                (this.options["recycle"] || this.options["teleport"]) &&
+                pieceIJ != "k"
+              )
+            )
+          ) {
+            explored[i + "." + j] = true;
+            addMove([x, y], [i, j]);
+          }
+        }
       }
+    };
+
+    const specialAttack = !!stepSpec.attack;
+    if (specialAttack)
+      findAddMoves("attack", stepSpec.attack);
+    findAddMoves(specialAttack ? "moveonly" : "all", stepSpec.moves);
+    if (this.options["zen"]) {
+      Array.prototype.push.apply(moves,
+                                 this.findCapturesOn([x, y], {zen: true}));
     }
-    if (this.options["zen"])
-      Array.prototype.push.apply(moves, this.getZenCaptures(x, y));
     return moves;
   }
 
-  getZenCaptures(x, y) {
+  // Search for enemy (or not) pieces attacking [x, y]
+  findCapturesOn([x, y], args) {
     let moves = [];
-    // Find reverse captures (opponent takes)
-    const color = this.getColor(x, y);
-    const oppCol = ChessRules.GetOppCol(color);
-    const pieces = this.pieces(oppCol);
-    Object.keys(pieces).forEach(p => {
-      if (p == ChessRules.KING) return; //king isn't captured this way
-      const steps = pieces[p].attack || pieces[p].steps;
-      const range = pieces[p].range;
-      steps.forEach(s => {
-        // From x,y: revert step
-        let [i, j] = [x - s[0], this.computeY(y - s[1])];
-        let stepCounter = 1;
-        while (this.onBoard(i, j) && this.board[i][j] == "") {
-          if (range <= stepCounter++) return;
-          i -= s[0];
-          j = this.computeY(j - s[1]);
-        }
+    if (!args.oppCol)
+      args.oppCol = C.GetOppCol(this.getColor(x, y) || this.turn);
+    for (let i=0; i<this.size.x; i++) {
+      for (let j=0; j<this.size.y; j++) {
         if (
-          this.onBoard(i, j) &&
-          this.getPiece(i, j) == p &&
-          this.getColor(i, j) == oppCol && //condition for Recycle & Teleport
-          this.canTake([i, j], [x, y])
+          this.board[i][j] != "" &&
+          this.getColor(i, j) == args.oppCol &&
+          !this.isImmobilized([i, j])
         ) {
-          if (this.getPiece(x, y) != ChessRules.PAWN)
-            moves.push(this.getBasicMove([x, y], [i, j]));
-          else this.addPawnMoves([x, y], [i, j], moves);
+          if (args.zen && this.isKing(this.getPiece(i, j)))
+            continue; //king not captured in this way
+          const stepSpec =
+            this.pieces(args.oppCol, i, j)[this.getPieceType(i, j)];
+          const attacks = stepSpec.attack || stepSpec.moves;
+          for (let a of attacks) {
+            for (let s of a.steps) {
+              // Quick check: if step isn't compatible, don't even try
+              if (!C.CompatibleStep([i, j], [x, y], s, a.range))
+                continue;
+              // Finally verify that nothing stand in-between
+              let [ii, jj] = [i + s[0], this.getY(j + s[1])];
+              let stepCounter = 1;
+              while (
+                this.onBoard(ii, jj) &&
+                this.board[ii][jj] == "" &&
+                (ii != x || jj != y) //condition to attack empty squares too
+              ) {
+                ii += s[0];
+                jj = this.getY(jj + s[1]);
+              }
+              if (ii == x && jj == y) {
+                if (args.zen)
+                  // Reverse capture:
+                  moves.push(this.getBasicMove([x, y], [i, j]));
+                else
+                  moves.push(this.getBasicMove([i, j], [x, y]));
+                if (args.one)
+                  return moves; //test for underCheck
+              }
+            }
+          }
         }
-      });
-    });
+      }
+    }
     return moves;
   }
 
+  static CompatibleStep([x1, y1], [x2, y2], step, range) {
+    const rx = (x2 - x1) / step[0],
+          ry = (y2 - y1) / step[1];
+    if (
+      (!Number.isFinite(rx) && !Number.isNaN(rx)) ||
+      (!Number.isFinite(ry) && !Number.isNaN(ry))
+    ) {
+      return false;
+    }
+    let distance = (Number.isNaN(rx) ? ry : rx);
+    // TODO: 1e-7 here is totally arbitrary
+    if (Math.abs(distance - Math.round(distance)) > 1e-7)
+      return false;
+    distance = Math.round(distance); //in case of (numerical...)
+    if (range < distance)
+      return false;
+    return true;
+  }
+
   // Build a regular move from its initial and destination squares.
   // tr: transformation
   getBasicMove([sx, sy], [ex, ey], tr) {
     const initColor = this.getColor(sx, sy);
-    const initPiece = this.board[sx][sy].charAt(1);
+    const initPiece = this.getPiece(sx, sy);
     const destColor = (this.board[ex][ey] != "" ? this.getColor(ex, ey) : "");
     let mv = new Move({
       appear: [],
       vanish: [],
-      start: {x:sx, y:sy},
-      end: {x:ex, y:ey}
+      start: {x: sx, y: sy},
+      end: {x: ex, y: ey}
     });
     if (
       !this.options["rifle"] ||
@@ -1388,23 +1699,23 @@ export default class ChessRules {
           x: ex,
           y: ey,
           c: this.getColor(ex, ey),
-          p: this.board[ex][ey].charAt(1)
+          p: this.getPiece(ex, ey)
         })
       );
-      if (this.options["rifle"])
-        // Rifle captures are tricky in combination with Atomic etc,
-        // so it's useful to mark the move :
-        mv.capture = true;
       if (this.options["cannibal"] && destColor != initColor) {
         const lastIdx = mv.vanish.length - 1;
-        if (mv.appear.length >= 1) mv.appear[0].p = mv.vanish[lastIdx].p;
+        let trPiece = mv.vanish[lastIdx].p;
+        if (this.isKing(this.getPiece(sx, sy)))
+          trPiece = C.CannibalKingCode[trPiece];
+        if (mv.appear.length >= 1)
+          mv.appear[0].p = trPiece;
         else if (this.options["rifle"]) {
           mv.appear.unshift(
             new PiPo({
               x: sx,
               y: sy,
               c: initColor,
-              p: mv.vanish[lastIdx].p
+              p: trPiece
             })
           );
           mv.vanish.unshift(
@@ -1425,8 +1736,9 @@ export default class ChessRules {
   getEpSquare(moveOrSquare) {
     if (typeof moveOrSquare === "string") {
       const square = moveOrSquare;
-      if (square == "-") return undefined;
-      return ChessRules.SquareToCoords(square);
+      if (square == "-")
+        return undefined;
+      return C.SquareToCoords(square);
     }
     // Argument is a move:
     const move = moveOrSquare;
@@ -1436,8 +1748,8 @@ export default class ChessRules {
       s.y == e.y &&
       Math.abs(s.x - e.x) == 2 &&
       // Next conditions for variants like Atomic or Rifle, Recycle...
-      (move.appear.length > 0 && move.appear[0].p == ChessRules.PAWN) &&
-      (move.vanish.length > 0 && move.vanish[0].p == ChessRules.PAWN)
+      (move.appear.length > 0 && move.appear[0].p == "p") &&
+      (move.vanish.length > 0 && move.vanish[0].p == "p")
     ) {
       return {
         x: (s.x + e.x) / 2,
@@ -1448,14 +1760,15 @@ export default class ChessRules {
   }
 
   // Special case of en-passant captures: treated separately
-  getEnpassantCaptures([x, y], shiftX) {
+  getEnpassantCaptures([x, y]) {
     const color = this.getColor(x, y);
-    const oppCol = ChessRules.GetOppCol(color);
+    const shiftX = (color == 'w' ? -1 : 1);
+    const oppCol = C.GetOppCol(color);
     let enpassantMove = null;
     if (
       !!this.epSquare &&
       this.epSquare.x == x + shiftX &&
-      Math.abs(this.computeY(this.epSquare.y - y)) == 1 &&
+      Math.abs(this.getY(this.epSquare.y - y)) == 1 &&
       this.getColor(x, this.epSquare.y) == oppCol //Doublemove guard...
     ) {
       const [epx, epy] = [this.epSquare.x, this.epSquare.y];
@@ -1468,149 +1781,29 @@ export default class ChessRules {
     return !!enpassantMove ? [enpassantMove] : [];
   }
 
-  // Consider all potential promotions:
-  addPawnMoves([x1, y1], [x2, y2], moves, promotions) {
-    let finalPieces = [ChessRules.PAWN];
-    const color = this.getColor(x1, y1);
-    const lastRank = (color == "w" ? 0 : this.size.x - 1);
-    if (x2 == lastRank && (!this.options["rifle"] || this.board[x2][y2] == ""))
-    {
-      // promotions arg: special override for Hiddenqueen variant
-      if (promotions) finalPieces = promotions;
-      else if (this.pawnSpecs.promotions)
-        finalPieces = this.pawnSpecs.promotions;
-    }
-    for (let piece of finalPieces) {
-      const tr = (piece != ChessRules.PAWN ? { c: color, p: piece } : null);
-      moves.push(this.getBasicMove([x1, y1], [x2, y2], tr));
-    }
-  }
-
-  // What are the pawn moves from square x,y ?
-  getPotentialPawnMoves([x, y], promotions) {
-    const color = this.getColor(x, y); //this.turn doesn't work for Dark mode
-    const [sizeX, sizeY] = [this.size.x, this.size.y];
-    const pawnShiftX = this.pawnSpecs.directions[color];
-    const firstRank = (color == "w" ? sizeX - 1 : 0);
-    const forward = (color == 'w' ? -1 : 1);
-
-    // Pawn movements in shiftX direction:
-    const getPawnMoves = (shiftX) => {
-      let moves = [];
-      // NOTE: next condition is generally true (no pawn on last rank)
-      if (x + shiftX >= 0 && x + shiftX < sizeX) {
-        if (this.board[x + shiftX][y] == "") {
-          // One square forward (or backward)
-          this.addPawnMoves([x, y], [x + shiftX, y], moves, promotions);
-          // Next condition because pawns on 1st rank can generally jump
-          if (
-            this.pawnSpecs.twoSquares &&
-            (
-              (
-                color == 'w' &&
-                x >= this.size.x - 1 - this.pawnSpecs.initShift['w']
-              )
-              ||
-              (color == 'b' && x <= this.pawnSpecs.initShift['b'])
-            )
-          ) {
-            if (
-              shiftX == forward &&
-              this.board[x + 2 * shiftX][y] == ""
-            ) {
-              // Two squares jump
-              moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
-              if (
-                this.pawnSpecs.threeSquares &&
-                this.board[x + 3 * shiftX, y] == ""
-              ) {
-                // Three squares jump
-                moves.push(this.getBasicMove([x, y], [x + 3 * shiftX, y]));
-              }
-            }
-          }
-        }
-        // Captures
-        if (this.pawnSpecs.canCapture) {
-          for (let shiftY of [-1, 1]) {
-            const yCoord = this.computeY(y + shiftY);
-            if (yCoord >= 0 && yCoord < sizeY) {
-              if (
-                this.board[x + shiftX][yCoord] != "" &&
-                this.canTake([x, y], [x + shiftX, yCoord]) &&
-                (
-                  !this.options["zen"] ||
-                  this.getPiece(x + shiftX, yCoord) == ChessRules.KING
-                )
-              ) {
-                this.addPawnMoves(
-                  [x, y], [x + shiftX, yCoord],
-                  moves, promotions
-                );
-              }
-              if (
-                this.pawnSpecs.captureBackward && shiftX == forward &&
-                x - shiftX >= 0 && x - shiftX < this.size.x &&
-                this.board[x - shiftX][yCoord] != "" &&
-                this.canTake([x, y], [x - shiftX, yCoord]) &&
-                (
-                  !this.options["zen"] ||
-                  this.getPiece(x + shiftX, yCoord) == ChessRules.KING
-                )
-              ) {
-                this.addPawnMoves(
-                  [x, y], [x - shiftX, yCoord],
-                  moves, promotions
-                );
-              }
-            }
-          }
-        }
-      }
-      return moves;
-    }
-
-    let pMoves = getPawnMoves(pawnShiftX);
-    if (this.pawnSpecs.bidirectional)
-      pMoves = pMoves.concat(getPawnMoves(-pawnShiftX));
-
-    if (this.hasEnpassant) {
-      // NOTE: backward en-passant captures are not considered
-      // because no rules define them (for now).
-      Array.prototype.push.apply(
-        pMoves,
-        this.getEnpassantCaptures([x, y], pawnShiftX)
-      );
-    }
-
-    if (this.options["zen"])
-      Array.prototype.push.apply(pMoves, this.getZenCaptures(x, y));
-
-    return pMoves;
-  }
-
   // "castleInCheck" arg to let some variants castle under check
   getCastleMoves([x, y], finalSquares, castleInCheck, castleWith) {
     const c = this.getColor(x, y);
 
     // Castling ?
-    const oppCol = ChessRules.GetOppCol(c);
+    const oppCol = C.GetOppCol(c);
     let moves = [];
     // King, then rook:
     finalSquares =
       finalSquares || [ [2, 3], [this.size.y - 2, this.size.y - 3] ];
-    const castlingKing = this.board[x][y].charAt(1);
+    const castlingKing = this.getPiece(x, y);
     castlingCheck: for (
       let castleSide = 0;
       castleSide < 2;
       castleSide++ //large, then small
     ) {
-      if (this.castleFlags[c][castleSide] >= this.size.y) continue;
+      if (this.castleFlags[c][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 castlingPiece = this.board[x][rookPos].charAt(1);
+      const castlingPiece = this.getPiece(x, rookPos);
       if (
         this.board[x][rookPos] == "" ||
         this.getColor(x, rookPos) != c ||
@@ -1639,7 +1832,8 @@ export default class ChessRules {
       // Nothing on the path to the rook?
       step = (castleSide == 0 ? -1 : 1);
       for (i = y + step; i != rookPos; i += step) {
-        if (this.board[x][i] != "") continue castlingCheck;
+        if (this.board[x][i] != "")
+          continue castlingCheck;
       }
 
       // Nothing on final squares, except maybe king and castling rook?
@@ -1680,8 +1874,8 @@ export default class ChessRules {
           ],
           end:
             Math.abs(y - rookPos) <= 2
-              ? { x: x, y: rookPos }
-              : { x: x, y: y + 2 * (castleSide == 0 ? -1 : 1) }
+              ? {x: x, y: rookPos}
+              : {x: x, y: y + 2 * (castleSide == 0 ? -1 : 1)}
         })
       );
     }
@@ -1692,68 +1886,38 @@ export default class ChessRules {
   ////////////////////
   // MOVES VALIDATION
 
-  // Is (king at) given position under check by "color" ?
-  underCheck([x, y], color) {
-    if (this.taking || this.options["dark"]) return false;
-    color = color || ChessRules.GetOppCol(this.getColor(x, y));
-    const pieces = this.pieces(color);
-    return Object.keys(pieces).some(p => {
-      return this.isAttackedBy([x, y], p, color, pieces[p]);
-    });
-  }
-
-  isAttackedBy([x, y], piece, color, stepSpec) {
-    const steps = stepSpec.attack || stepSpec.steps;
-    const range = stepSpec.range;
-    let explored = {}; //for Cylinder mode
-    outerLoop: for (let step of steps) {
-      let rx = x - step[0],
-          ry = this.computeY(y - step[1]);
-      let stepCounter = 1;
-      while (
-        this.onBoard(rx, ry) &&
-        this.board[rx][ry] == "" &&
-        !explored[rx + "." + ry]
-      ) {
-        explored[rx + "." + ry] = true;
-        if (range <= stepCounter++) continue outerLoop;
-        rx -= step[0];
-        ry = this.computeY(ry - step[1]);
-      }
-      if (
-        this.onBoard(rx, ry) &&
-        this.board[rx][ry] != "" &&
-        this.getPiece(rx, ry) == piece &&
-        this.getColor(rx, ry) == color &&
-        (!this.options["madrasi"] || !this.isImmobilized([rx, ry]))
-      ) {
-        return true;
-      }
-    }
-    return false;
+  // Is (king at) given position under check by "oppCol" ?
+  underCheck([x, y], oppCol) {
+    if (this.options["taking"] || this.options["dark"])
+      return false;
+    return (
+      this.findCapturesOn([x, y], {oppCol: oppCol, one: true}).length >= 1
+    );
   }
 
   // Stop at first king found (TODO: multi-kings)
   searchKingPos(color) {
     for (let i=0; i < this.size.x; i++) {
       for (let j=0; j < this.size.y; j++) {
-        if (this.board[i][j] == color + 'k') return [i, j];
+        if (this.getColor(i, j) == color && this.isKing(this.getPiece(i, j)))
+          return [i, j];
       }
     }
     return [-1, -1]; //king not found
   }
 
   filterValid(moves) {
-    if (moves.length == 0) return [];
+    if (moves.length == 0)
+      return [];
     const color = this.turn;
-    const oppCol = ChessRules.GetOppCol(color);
+    const oppCol = C.GetOppCol(color);
     if (this.options["balance"] && [1, 3].includes(this.movesCount)) {
       // Forbid moves either giving check or exploding opponent's king:
       const oppKingPos = this.searchKingPos(oppCol);
       moves = moves.filter(m => {
         if (
-          m.vanish.some(v => v.c == oppCol && v.p == ChessRules.KING) &&
-          m.appear.every(a => a.c != oppCol || a.p != ChessRUles.KING)
+          m.vanish.some(v => v.c == oppCol && v.p == "k") &&
+          m.appear.every(a => a.c != oppCol || a.p != "k")
         )
           return false;
         this.playOnBoard(m);
@@ -1762,7 +1926,8 @@ export default class ChessRules {
         return res;
       });
     }
-    if (this.taking || this.options["dark"]) return moves;
+    if (this.options["taking"] || this.options["dark"])
+      return moves;
     const kingPos = this.searchKingPos(color);
     let filtered = {}; //avoid re-checking similar moves (promotions...)
     return moves.filter(m => {
@@ -1771,13 +1936,18 @@ export default class ChessRules {
         this.playOnBoard(m);
         let square = kingPos,
             res = true; //a priori valid
-        if (m.vanish.some(v => v.p == ChessRules.KING && v.c == color)) {
+        if (m.vanish.some(v => {
+          return C.CannibalKings[v.p] && v.c == color;
+        })) {
           // Search king in appear array:
           const newKingIdx =
-            m.appear.findIndex(a => a.p == ChessRules.KING && a.c == color);
+            m.appear.findIndex(a => {
+              return C.CannibalKings[a.p] && a.c == color;
+            });
           if (newKingIdx >= 0)
             square = [m.appear[newKingIdx].x, m.appear[newKingIdx].y];
-          else res = false;
+          else
+            res = false;
         }
         res &&= !this.underCheck(square, oppCol);
         this.undoOnBoard(m);
@@ -1803,13 +1973,17 @@ export default class ChessRules {
 
   // Apply a move on board
   playOnBoard(move) {
-    for (let psq of move.vanish) this.board[psq.x][psq.y] = "";
-    for (let psq of move.appear) this.board[psq.x][psq.y] = psq.c + psq.p;
+    for (let psq of move.vanish)
+      this.board[psq.x][psq.y] = "";
+    for (let psq of move.appear)
+      this.board[psq.x][psq.y] = psq.c + psq.p;
   }
   // Un-apply the played move
   undoOnBoard(move) {
-    for (let psq of move.appear) this.board[psq.x][psq.y] = "";
-    for (let psq of move.vanish) this.board[psq.x][psq.y] = psq.c + psq.p;
+    for (let psq of move.appear)
+      this.board[psq.x][psq.y] = "";
+    for (let psq of move.vanish)
+      this.board[psq.x][psq.y] = psq.c + psq.p;
   }
 
   updateCastleFlags(move) {
@@ -1817,95 +1991,115 @@ export default class ChessRules {
     move.appear.concat(move.vanish).forEach(psq => {
       if (
         this.board[psq.x][psq.y] != "" &&
-        this.getPiece(psq.x, psq.y) == ChessRules.KING
+        this.getPieceType(psq.x, psq.y) == "k"
       ) {
         this.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) c = 'b';
-      else if (psq.x == this.size.x - 1) c = 'w';
-      if (c != '') {
+      let c = "";
+      if (psq.x == 0)
+        c = "b";
+      else if (psq.x == this.size.x - 1)
+        c = "w";
+      if (c != "") {
         const fidx = this.castleFlags[c].findIndex(f => f == psq.y);
-        if (fidx >= 0) this.castleFlags[c][fidx] = this.size.y;
+        if (fidx >= 0)
+          this.castleFlags[c][fidx] = this.size.y;
       }
     });
   }
 
   prePlay(move) {
     if (
-      typeof move.start.x == "number" &&
-      (!this.options["teleport"] || this.subTurn == 1)
+      this.hasCastle &&
+      // If flags already off, no need to re-check:
+      Object.keys(this.castleFlags).some(c => {
+        return this.castleFlags[c].some(val => val < this.size.y)})
     ) {
-      // OK, not a drop move
-      if (
-        this.hasCastle &&
-        // If flags already off, no need to re-check:
-        Object.keys(this.castleFlags).some(c => {
-          return this.castleFlags[c].some(val => val < this.size.y)})
-      ) {
-        this.updateCastleFlags(move);
-      }
-      const initSquare = ChessRules.CoordsToSquare(move.start);
-      if (
-        this.options["crazyhouse"] &&
-        (!this.options["rifle"] || !move.capture)
-      ) {
-        if (this.ispawn[initSquare]) {
-          delete this.ispawn[initSquare];
-          this.ispawn[ChessRules.CoordsToSquare(move.end)] = true;
+      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);
+        const destSquare = C.CoordsToSquare(move.end);
+        if (
+          this.ispawn[initSquare] ||
+          (move.vanish[0].p == "p" && move.appear[0].p != "p")
+        ) {
+          this.ispawn[destSquare] = true;
         }
         else if (
-          move.vanish[0].p == ChessRules.PAWN &&
-          move.appear[0].p != ChessRules.PAWN
+          this.ispawn[destSquare] &&
+          this.getColor(move.end.x, move.end.y) != move.vanish[0].c
         ) {
-          this.ispawn[ChessRules.CoordsToSquare(move.end)] = true;
+          move.vanish[1].p = "p";
+          delete this.ispawn[destSquare];
         }
       }
     }
     const minSize = Math.min(move.appear.length, move.vanish.length);
-    if (this.hasReserve) {
+    if (
+      this.hasReserve &&
+      // Warning; atomic pawn removal isn't a capture
+      (!this.options["atomic"] || !this.rempawn || this.movesCount >= 1)
+    ) {
       const color = this.turn;
       for (let i=minSize; i<move.appear.length; i++) {
         // Something appears = dropped on board (some exceptions, Chakart...)
-        const piece = move.appear[i].p;
-        this.updateReserve(color, piece, this.reserve[color][piece] - 1);
+        if (move.appear[i].c == color) {
+          const piece = move.appear[i].p;
+          this.updateReserve(color, piece, this.reserve[color][piece] - 1);
+        }
       }
       for (let i=minSize; i<move.vanish.length; i++) {
         // Something vanish: add to reserve except if recycle & opponent
-        const piece = move.vanish[i].p;
-        if (this.options["crazyhouse"] || move.vanish[i].c == color)
+        if (
+          this.options["crazyhouse"] ||
+          (this.options["recycle"] && move.vanish[i].c == color)
+        ) {
+          const piece = move.vanish[i].p;
           this.updateReserve(color, piece, this.reserve[color][piece] + 1);
+        }
       }
     }
   }
 
   play(move) {
     this.prePlay(move);
-    if (this.hasEnpassant) this.epSquare = this.getEpSquare(move);
+    if (this.hasEnpassant)
+      this.epSquare = this.getEpSquare(move);
     this.playOnBoard(move);
     this.postPlay(move);
   }
 
   postPlay(move) {
     const color = this.turn;
-    const oppCol = ChessRules.GetOppCol(color);
-    if (this.options["dark"]) this.updateEnlightened(true);
+    const oppCol = C.GetOppCol(color);
+    if (this.options["dark"])
+      this.updateEnlightened();
     if (this.options["teleport"]) {
       if (
-        this.subTurn == 1 &&
+        this.subTurnTeleport == 1 &&
         move.vanish.length > move.appear.length &&
         move.vanish[move.vanish.length - 1].c == color
       ) {
         const v = move.vanish[move.vanish.length - 1];
         this.captured = {x: v.x, y: v.y, c: v.c, p: v.p};
-        this.subTurn = 2;
+        this.subTurnTeleport = 2;
         return;
       }
+      this.subTurnTeleport = 1;
       this.captured = null;
     }
     if (this.options["balance"]) {
-      if (![1, 3].includes(this.movesCount)) this.turn = oppCol;
+      if (![1, 3].includes(this.movesCount))
+        this.turn = oppCol;
     }
     else {
       if (
@@ -1917,7 +2111,13 @@ export default class ChessRules {
         (this.options["progressive"] && this.subTurn <= this.movesCount)
       ) {
         const oppKingPos = this.searchKingPos(oppCol);
-        if (oppKingPos[0] >= 0 && !this.underCheck(oppKingPos, color)) {
+        if (
+          oppKingPos[0] >= 0 &&
+          (
+            this.options["taking"] ||
+            !this.underCheck(oppKingPos, color)
+          )
+        ) {
           this.subTurn++;
           return;
         }
@@ -1934,16 +2134,19 @@ export default class ChessRules {
     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) {
-          // TODO?: do not search all possible moves here
+          // 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]);
-          if (moves.some(m => this.filterValid([m]).length >= 1)) return true;
+          if (moves.some(m => this.filterValid([m]).length >= 1))
+            return true;
         }
       }
     }
     if (this.hasReserve && this.reserve[color]) {
       for (let p of Object.keys(this.reserve[color])) {
         const moves = this.getDropMovesFrom([color, p]);
-        if (moves.some(m => this.filterValid([m]).length >= 1)) return true;
+        if (moves.some(m => this.filterValid([m]).length >= 1))
+          return true;
       }
     }
     return false;
@@ -1952,152 +2155,169 @@ export default class ChessRules {
   // What is the score ? (Interesting if game is over)
   getCurrentScore(move) {
     const color = this.turn;
-    const oppCol = ChessRules.GetOppCol(color);
+    const oppCol = C.GetOppCol(color);
     const kingPos = [this.searchKingPos(color), this.searchKingPos(oppCol)];
-    if (kingPos[0][0] < 0 && kingPos[1][0] < 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()) return "*";
+    if (kingPos[0][0] < 0 && kingPos[1][0] < 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())
+      return "*";
     // No valid move: stalemate or checkmate?
-    if (!this.underCheck(kingPos, color)) return "1/2";
+    if (!this.underCheck(kingPos[0], color))
+      return "1/2";
     // OK, checkmate
     return (color == "w" ? "0-1" : "1-0");
   }
 
-  // NOTE: quite suboptimal for eg. Benedict (TODO?)
   playVisual(move, r) {
     move.vanish.forEach(v => {
-      if (!this.enlightened || this.enlightened[v.x][v.y]) {
-        this.g_pieces[v.x][v.y].remove();
-        this.g_pieces[v.x][v.y] = null;
-      }
+      this.g_pieces[v.x][v.y].remove();
+      this.g_pieces[v.x][v.y] = null;
     });
-    let container = document.getElementById(this.containerId);
-    if (!r) r = container.getBoundingClientRect();
+    let chessboard =
+      document.getElementById(this.containerId).querySelector(".chessboard");
+    if (!r)
+      r = chessboard.getBoundingClientRect();
     const pieceWidth = this.getPieceWidth(r.width);
     move.appear.forEach(a => {
-      if (this.enlightened && !this.enlightened[a.x][a.y]) return;
       this.g_pieces[a.x][a.y] = document.createElement("piece");
-      this.g_pieces[a.x][a.y].classList.add(this.pieces()[a.p]["class"]);
-      this.g_pieces[a.x][a.y].classList.add(a.c == "w" ? "white" : "black");
+      C.AddClass_es(this.g_pieces[a.x][a.y], this.pieces()[a.p]["class"]);
+      this.g_pieces[a.x][a.y].classList.add(C.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);
-      this.g_pieces[a.x][a.y].style.transform = `translate(${ip}px,${jp}px)`;
-      container.appendChild(this.g_pieces[a.x][a.y]);
+      // Translate coordinates to use chessboard as reference:
+      this.g_pieces[a.x][a.y].style.transform =
+        `translate(${ip - r.x}px,${jp - r.y}px)`;
+      if (this.enlightened && !this.enlightened[a.x][a.y])
+        this.g_pieces[a.x][a.y].classList.add("hidden");
+      chessboard.appendChild(this.g_pieces[a.x][a.y]);
     });
+    if (this.options["dark"])
+      this.graphUpdateEnlightened();
   }
 
   playPlusVisual(move, r) {
-    this.playVisual(move, r);
     this.play(move);
+    this.playVisual(move, r);
     this.afterPlay(move); //user method
   }
 
-  // Assumes reserve on top (usage case otherwise? TODO?)
-  getReserveShift(c, p, r) {
-    let nbR = 0,
-        ridx = 0;
-    for (let pi of Object.keys(this.reserve[c])) {
-      if (this.reserve[c][pi] == 0) continue;
-      if (pi == p) ridx = nbR;
-      nbR++;
-    }
-    const rsqSize = this.getReserveSquareSize(r.width, nbR);
-    return [ridx * rsqSize, rsqSize]; //slightly inaccurate... TODO?
+  getMaxDistance(rwidth) {
+    // Works for all rectangular boards:
+    return Math.sqrt(rwidth ** 2 + (rwidth / this.size.ratio) ** 2);
+  }
+
+  getDomPiece(x, y) {
+    return (typeof x == "string" ? this.r_pieces : this.g_pieces)[x][y];
   }
 
   animate(move, callback) {
-    if (this.noAnimate) {
+    if (this.noAnimate || move.noAnimate) {
       callback();
       return;
     }
-    const [i1, j1] = [move.start.x, move.start.y];
-    const dropMove = (typeof i1 == "string");
-    const startArray = (dropMove ? this.r_pieces : this.g_pieces);
-    let startPiece = startArray[i1][j1];
-    let container = document.getElementById(this.containerId);
-    const clonePiece = (
-      !dropMove &&
-      this.options["rifle"] ||
-      (this.options["teleport"] && this.subTurn == 2)
-    );
-    if (clonePiece) {
-      startPiece = startPiece.cloneNode();
-      if (this.options["rifle"]) startArray[i1][j1].style.opacity = "0";
-      if (this.options["teleport"] && this.subTurn == 2) {
-        const pieces = this.pieces();
-        const startCode = (dropMove ? j1 : this.getPiece(i1, j1));
-        startPiece.classList.remove(pieces[startCode]["class"]);
-        startPiece.classList.add(pieces[this.captured.p]["class"]);
-        // Color: OK
+    let initPiece = this.getDomPiece(move.start.x, move.start.y);
+    // NOTE: cloning generally not required, but light enough, and simpler
+    let movingPiece = initPiece.cloneNode();
+    initPiece.style.opacity = "0";
+    let container =
+      document.getElementById(this.containerId)
+    const r = container.querySelector(".chessboard").getBoundingClientRect();
+    if (typeof move.start.x == "string") {
+      // Need to bound width/height (was 100% for reserve pieces)
+      const pieceWidth = this.getPieceWidth(r.width);
+      movingPiece.style.width = pieceWidth + "px";
+      movingPiece.style.height = pieceWidth + "px";
+    }
+    const maxDist = this.getMaxDistance(r.width);
+    const pieces = this.pieces();
+    if (move.drag) {
+      const startCode = this.getPiece(move.start.x, move.start.y);
+      C.RemoveClass_es(movingPiece, pieces[startCode]["class"]);
+      C.AddClass_es(movingPiece, pieces[move.drag.p]["class"]);
+      const apparentColor = this.getColor(move.start.x, move.start.y);
+      if (apparentColor != move.drag.c) {
+        movingPiece.classList.remove(C.GetColorClass(apparentColor));
+        movingPiece.classList.add(C.GetColorClass(move.drag.c));
       }
-      container.appendChild(startPiece);
-    }
-    const [i2, j2] = [move.end.x, move.end.y];
-    let startCoords;
-    if (dropMove) {
-      startCoords = [
-        i1 == this.playerColor ? this.size.x : 0,
-        this.size.y / 2 //not trying to be accurate here... (TODO?)
+    }
+    container.appendChild(movingPiece);
+    const animateSegment = (index, cb) => {
+      // NOTE: move.drag could be generalized per-segment (usage?)
+      const [i1, j1] = move.segments[index][0];
+      const [i2, j2] = move.segments[index][1];
+      const dep = this.getPixelPosition(i1, j1, r);
+      const arr = this.getPixelPosition(i2, j2, r);
+      movingPiece.style.transitionDuration = "0s";
+      movingPiece.style.transform = `translate(${dep[0]}px, ${dep[1]}px)`;
+      const distance =
+        Math.sqrt((arr[0] - dep[0]) ** 2 + (arr[1] - dep[1]) ** 2);
+      const duration = 0.2 + (distance / maxDist) * 0.3;
+      // TODO: unclear why we need this new delay below:
+      setTimeout(() => {
+        movingPiece.style.transitionDuration = duration + "s";
+        // movingPiece is child of container: no need to adjust coordinates
+        movingPiece.style.transform = `translate(${arr[0]}px, ${arr[1]}px)`;
+        setTimeout(cb, duration * 1000);
+      }, 50);
+    };
+    if (!move.segments) {
+      move.segments = [
+        [[move.start.x, move.start.y], [move.end.x, move.end.y]]
       ];
     }
-    else startCoords = [i1, j1];
-    const r = container.getBoundingClientRect();
-    const arrival = this.getPixelPosition(i2, j2, r); //TODO: arrival on drop?
-    let rs = [0, 0];
-    if (dropMove) rs = this.getReserveShift(i1, j1, r);
-    const distance =
-      Math.sqrt((startCoords[0] - i2) ** 2 + (startCoords[1] - j2) ** 2);
-    const maxDist = Math.sqrt((this.size.x - 1)** 2 + (this.size.y - 1) ** 2);
-    const multFact = (distance - 1) / (maxDist - 1); //1 == minDist
-    const duration = 0.2 + multFact * 0.3;
-    startPiece.style.transform =
-      `translate(${arrival[0] + rs[0]}px, ${arrival[1] + rs[1]}px)`;
-    startPiece.style.transitionDuration = duration + "s";
-    setTimeout(
-      () => {
-        if (clonePiece) {
-          if (this.options["rifle"]) startArray[i1][j1].style.opacity = "1";
-          startPiece.remove();
-        }
+    let index = 0;
+    const animateSegmentCallback = () => {
+      if (index < move.segments.length)
+        animateSegment(index++, animateSegmentCallback);
+      else {
+        movingPiece.remove();
+        initPiece.style.opacity = "1";
         callback();
-      },
-      duration * 1000
-    );
+      }
+    };
+    animateSegmentCallback();
   }
 
   playReceivedMove(moves, callback) {
     const launchAnimation = () => {
-      const r =
-        document.getElementById(this.containerId).getBoundingClientRect();
+      const r = container.querySelector(".chessboard").getBoundingClientRect();
       const animateRec = i => {
         this.animate(moves[i], () => {
-          this.playVisual(moves[i], r);
           this.play(moves[i]);
-          if (i < moves.length - 1) setTimeout(() => animateRec(i+1), 300);
-          else callback();
+          this.playVisual(moves[i], r);
+          if (i < moves.length - 1)
+            setTimeout(() => animateRec(i+1), 300);
+          else
+            callback();
         });
       };
       animateRec(0);
     };
-    const checkDisplayThenAnimate = () => {
-      if (boardContainer.style.display == "none") {
+    // 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";
-        boardContainer.style.display = "block";
+        container.style.display = "block";
         setTimeout(launchAnimation, 700);
       }
-      else launchAnimation(); //focused user!
+      else
+        setTimeout(launchAnimation, delay || 0);
     };
-    let boardContainer = document.getElementById("boardContainer");
-    if (!document.hasFocus()) {
-      window.onfocus = () => {
-        window.onfocus = undefined;
-        checkDisplayThenAnimate();
+    let container = document.getElementById(this.containerId);
+    if (document.hidden) {
+      document.onvisibilitychange = () => {
+        document.onvisibilitychange = undefined;
+        checkDisplayThenAnimate(700);
       };
     }
-    else checkDisplayThenAnimate();
+    else
+      checkDisplayThenAnimate();
   }
 
 };