X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=base_rules.js;h=1b22ae5e256588eb4d8731e37e7ace4df68eaa31;hb=554e3ad3773a3123701bd894db1df4c1843283b8;hp=df49f841d1bbce53205e4d09db153c594809f0af;hpb=9db5050a189571c9f3018d4d25c7d304ca1a22dc;p=xogo.git

diff --git a/base_rules.js b/base_rules.js
index df49f84..1b22ae5 100644
--- a/base_rules.js
+++ b/base_rules.js
@@ -29,16 +29,18 @@ export default class ChessRules {
           {label: "Asymmetric random", value: 2}
         ]
       }],
-      check: [
+      input: [
         {
           label: "Capture king",
-          defaut: false,
-          variable: "taking"
+          variable: "taking",
+          type: "checkbox",
+          defaut: false
         },
         {
           label: "Falling pawn",
-          defaut: false,
-          variable: "pawnfall"
+          variable: "pawnfall",
+          type: "checkbox",
+          defaut: false
         }
       ],
       // Game modifiers (using "elementary variants"). Default: false
@@ -85,6 +87,10 @@ 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"];
@@ -98,7 +104,7 @@ export default class ChessRules {
       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({
@@ -108,9 +114,10 @@ export default class ChessRules {
             p: this.captured.p
           })
         ],
-        vanish: [],
-        drag: {c: this.captured.c, p: this.captured.p}
+        vanish: []
       });
+      res.drag = {c: this.captured.c, p: this.captured.p};
+      return res;
     }
     return null;
   }
@@ -172,8 +179,6 @@ export default class ChessRules {
 
   // Setup the initial random-or-not (asymmetric-or-not) position
   genRandInitFen(seed) {
-    Random.setSeed(seed);
-
     let fen, flags = "0707";
     if (!this.options.randomness)
       // Deterministic:
@@ -181,7 +186,8 @@ export default class ChessRules {
 
     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"]) {
@@ -280,7 +286,7 @@ export default class ChessRules {
       parts.push(`"flags":"${this.getFlagsFen()}"`);
     if (this.hasEnpassant)
       parts.push(`"enpassant":"${this.getEnpassantFen()}"`);
-    if (this.hasReserve)
+    if (this.hasReserveFen)
       parts.push(`"reserve":"${this.getReserveFen()}"`);
     if (this.options["crazyhouse"])
       parts.push(`"ispawn":"${this.getIspawnFen()}"`);
@@ -289,19 +295,20 @@ export default class ChessRules {
     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
   getPosition() {
-    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);
-    };
     let position = "";
     for (let i = 0; i < this.size.y; i++) {
       let emptyCount = 0;
@@ -311,7 +318,7 @@ export default class ChessRules {
         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]);
@@ -319,7 +326,7 @@ export default class ChessRules {
       }
       if (emptyCount > 0)
         // "Flush remainder"
-        position += format(emptyCount);
+        position += C.FenEmptySquares(emptyCount);
       if (i < this.size.y - 1)
         position += "/"; //separate rows
     }
@@ -370,6 +377,14 @@ export default class ChessRules {
 
   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; //trigger some actions after playing a move
 
@@ -455,7 +470,7 @@ export default class ChessRules {
     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 &&
@@ -519,6 +534,22 @@ 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();
@@ -526,7 +557,6 @@ export default class ChessRules {
     this.initMouseEvents();
     const chessboard =
       document.getElementById(this.containerId).querySelector(".chessboard");
-    new ResizeObserver(this.rescale).observe(chessboard);
   }
 
   re_drawBoardElements() {
@@ -549,7 +579,7 @@ export default class ChessRules {
       cbHeight = Math.min(window.innerHeight, 767);
       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.
@@ -581,8 +611,7 @@ export default class ChessRules {
     let board = `
       <svg
         viewBox="0 0 80 80"
-        class="chessboard_SVG">
-      <g>`;
+        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);
@@ -591,16 +620,18 @@ export default class ChessRules {
         if (this.enlightened && !this.enlightened[ii][jj])
           classes += " in-shadow";
         // NOTE: x / y reversed because coordinates system is reversed.
-        board += `<rect
-          class="${classes}"
-          id="${this.coordsToId({x: ii, y: 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;
   }
 
@@ -634,7 +665,7 @@ export default class ChessRules {
           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"]);
+          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";
@@ -648,28 +679,21 @@ export default class ChessRules {
         }
       }
     }
-    if (this.reserve)
+    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
@@ -678,6 +702,9 @@ export default class ChessRules {
     if (!r)
       r = container.querySelector(".chessboard").getBoundingClientRect();
     for (let c of colors) {
+      let reservesDiv = document.getElementById("reserves_" + c);
+      if (reservesDiv)
+        reservesDiv.remove();
       if (!this.reserve[c])
         continue;
       const nbR = this.getNbReservePieces(c);
@@ -706,8 +733,7 @@ export default class ChessRules {
         r_cell.style.height = sqResSize + "px";
         rcontainer.appendChild(r_cell);
         let piece = document.createElement("piece");
-        const pieceSpec = this.pieces()[p];
-        piece.classList.add(pieceSpec["class"]);
+        C.AddClass_es(piece, this.pieces()[p]["class"]);
         piece.classList.add(C.GetColorClass(c));
         piece.style.width = "100%";
         piece.style.height = "100%";
@@ -764,44 +790,48 @@ export default class ChessRules {
     }
   }
 
-  // After resize event: no need to destroy/recreate pieces
-  rescale() {
-    const container = document.getElementById(this.containerId);
-    if (!container)
-      return; //useful at initial loading
-    let chessboard = container.querySelector(".chessboard");
+  // Resize board: no need to destroy/recreate pieces
+  rescale(mode) {
+    let chessboard =
+      document.getElementById(this.containerId).querySelector(".chessboard");
     const r = chessboard.getBoundingClientRect();
-    const newRatio = r.width / r.height;
-    let newWidth = r.width,
-        newHeight = r.height;
-    if (newRatio > this.size.ratio) {
-      newWidth = r.height * this.size.ratio;
-      chessboard.style.width = newWidth + "px";
+    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;
     }
-    else if (newRatio < this.size.ratio) {
-      newHeight = r.width / this.size.ratio;
-      chessboard.style.height = newHeight + "px";
+    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;
     chessboard.style.left = newX + "px";
     const newY = (window.innerHeight - newHeight) / 2;
     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.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)`;
+    // 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)
+    if (this.hasReserve)
       this.rescaleReserve(newR);
   }
 
@@ -932,11 +962,6 @@ export default class ChessRules {
     };
 
     const mouseup = (e) => {
-      const newR = chessboard.getBoundingClientRect();
-      if (newR.width != r.width || newR.height != r.height) {
-        this.rescale();
-        return;
-      }
       if (!start)
         return;
       const [x, y] = [start.x, start.y];
@@ -965,6 +990,8 @@ 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) {
       // https://stackoverflow.com/a/42509310/12660887
@@ -980,6 +1007,8 @@ export default class ChessRules {
     let chessboard = container.querySelector(".chessboard");
     let choices = document.createElement("div");
     choices.id = "choices";
+    if (!r)
+      r = chessboard.getBoundingClientRect();
     choices.style.width = r.width + "px";
     choices.style.height = r.height + "px";
     choices.style.left = r.x + "px";
@@ -1005,8 +1034,8 @@ export default class ChessRules {
       choice.style.backgroundColor = "lightyellow";
       choice.onclick = () => callback(moves[i]);
       const piece = document.createElement("piece");
-      const pieceSpec = this.pieces()[moves[i].appear[0].p];
-      piece.classList.add(pieceSpec["class"]);
+      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%";
@@ -1034,7 +1063,11 @@ export default class ChessRules {
   }
 
   static GetColorClass(c) {
-    return (c == 'w' ? "white" : "black");
+    if (c == 'w')
+      return "white";
+    if (c == 'b')
+      return "black";
+    return "other-color"; //unidentified color
   }
 
   // Assume square i,j isn't empty
@@ -1159,7 +1192,7 @@ export default class ChessRules {
   // MOVES GENERATION
 
   // For Cylinder: get Y coordinate
-  computeY(y) {
+  getY(y) {
     if (!this.options["cylinder"])
       return y;
     let res = y % this.size.y;
@@ -1180,13 +1213,13 @@ export default class ChessRules {
           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.computeY(j + step[1])];
+              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.computeY(jj + step[1]);
+                jj = this.getY(jj + step[1]);
               }
               if (
                 this.onBoard(ii, jj) &&
@@ -1207,7 +1240,7 @@ export default class ChessRules {
 
   getDropMovesFrom([c, p]) {
     // NOTE: by design, this.reserve[c][p] >= 1 on user click
-    // (but not necessarily otherwise)
+    // (but not necessarily otherwise: atLeastOneMove() etc)
     if (this.reserve[c][p] == 0)
       return [];
     let moves = [];
@@ -1323,7 +1356,7 @@ export default class ChessRules {
         ];
         for (let step of steps) {
           let x = m.end.x + step[0];
-          let y = this.computeY(m.end.y + step[1]);
+          let y = this.getY(m.end.y + step[1]);
           if (
             this.onBoard(x, y) &&
             this.board[x][y] != "" &&
@@ -1455,7 +1488,7 @@ export default class ChessRules {
           if (a.range <= stepCounter++)
             continue outerLoop;
           i += step[0];
-          j = this.computeY(j + step[1]);
+          j = this.getY(j + step[1]);
         }
         if (
           this.onBoard(i, j) &&
@@ -1469,28 +1502,59 @@ export default class ChessRules {
     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, x, y)[piece];
     let moves = [];
-    let explored = {}; //for Cylinder mode
+    // 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]]]);
+      }
+      moves.push(newMove);
+    };
 
     const findAddMoves = (type, stepArray) => {
       for (let s of stepArray) {
-        // TODO: if jump in y (computeY, Cylinder), move.segments
         outerLoop: for (let step of s.steps) {
-          let [i, j] = [x + step[0], this.computeY(y + step[1])];
-          let stepCounter = 1;
-          while (this.onBoard(i, j) && this.board[i][j] == "") {
-            if (type != "attack" && !explored[i + "." + j]) {
+          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;
-              moves.push(this.getBasicMove([x, y], [i, j]));
+              addMove([x, y], [i, j]);
             }
             if (s.range <= stepCounter++)
               continue outerLoop;
+            const oldIJ = [i, j];
             i += step[0];
-            j = this.computeY(j + step[1]);
+            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;
@@ -1511,7 +1575,7 @@ export default class ChessRules {
             )
           ) {
             explored[i + "." + j] = true;
-            moves.push(this.getBasicMove([x, y], [i, j]));
+            addMove([x, y], [i, j]);
           }
         }
       }
@@ -1521,26 +1585,29 @@ export default class ChessRules {
     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], true));
+    if (this.options["zen"]) {
+      Array.prototype.push.apply(moves,
+                                 this.findCapturesOn([x, y], {zen: true}));
+    }
     return moves;
   }
 
-  findCapturesOn([x, y], zen) {
+  // 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 = C.GetOppCol(color);
+    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.board[i][j] != "" &&
-          this.canTake([i, j], [x, y]) &&
+          this.getColor(i, j) == args.oppCol &&
           !this.isImmobilized([i, j])
         ) {
-          if (zen && this.isKing(this.getPiece(i, j)))
+          if (args.zen && this.isKing(this.getPiece(i, j)))
             continue; //king not captured in this way
-          const stepSpec = this.pieces(oppCol, i, j)[this.getPieceType(i, j)];
+          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) {
@@ -1548,15 +1615,23 @@ export default class ChessRules {
               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.computeY(j + s[1])];
+              let [ii, jj] = [i + s[0], this.getY(j + s[1])];
               let stepCounter = 1;
-              while (this.onBoard(ii, jj) && this.board[ii][jj] == "") {
+              while (
+                this.onBoard(ii, jj) &&
+                this.board[ii][jj] == "" &&
+                (ii != x || jj != y) //condition to attack empty squares too
+              ) {
                 ii += s[0];
-                jj = this.computeY(jj + s[1]);
+                jj = this.getY(jj + s[1]);
               }
               if (ii == x && jj == y) {
-                moves.push(this.getBasicMove([x, y], [i, j]));
-                if (!zen)
+                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
               }
             }
@@ -1695,7 +1770,7 @@ export default class ChessRules {
     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];
@@ -1813,11 +1888,13 @@ export default class ChessRules {
   ////////////////////
   // MOVES VALIDATION
 
-  // Is (king at) given position under check by "color" ?
-  underCheck([x, y], color) {
+  // 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]).length >= 1);
+    return (
+      this.findCapturesOn([x, y], {oppCol: oppCol, one: true}).length >= 1
+    );
   }
 
   // Stop at first king found (TODO: multi-kings)
@@ -1831,10 +1908,12 @@ export default class ChessRules {
     return [-1, -1]; //king not found
   }
 
-  filterValid(moves) {
+  // Some variants (e.g. Refusal) may need to check opponent moves too
+  filterValid(moves, color) {
     if (moves.length == 0)
       return [];
-    const color = this.turn;
+    if (!color)
+      color = this.turn;
     const oppCol = C.GetOppCol(color);
     if (this.options["balance"] && [1, 3].includes(this.movesCount)) {
       // Forbid moves either giving check or exploding opponent's king:
@@ -2099,9 +2178,7 @@ export default class ChessRules {
 
   playVisual(move, r) {
     move.vanish.forEach(v => {
-      // TODO: next "if" shouldn't be required
-      if (this.g_pieces[v.x][v.y])
-        this.g_pieces[v.x][v.y].remove();
+      this.g_pieces[v.x][v.y].remove();
       this.g_pieces[v.x][v.y] = null;
     });
     let chessboard =
@@ -2111,8 +2188,8 @@ export default class ChessRules {
     const pieceWidth = this.getPieceWidth(r.width);
     move.appear.forEach(a => {
       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);
@@ -2148,22 +2225,24 @@ export default class ChessRules {
       return;
     }
     let initPiece = this.getDomPiece(move.start.x, move.start.y);
-    if (!initPiece) { //TODO this shouldn't be required
-      callback();
-      return;
-    }
     // 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);
-      movingPiece.classList.remove(pieces[startCode]["class"]);
-      movingPiece.classList.add(pieces[move.drag.p]["class"]);
+      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));
@@ -2185,7 +2264,7 @@ export default class ChessRules {
       // TODO: unclear why we need this new delay below:
       setTimeout(() => {
         movingPiece.style.transitionDuration = duration + "s";
-        // movingPiece is child of container: no need to adjust cordinates
+        // 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);