X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=client%2Fsrc%2Fcomponents%2FBoard.vue;h=7f2e43e4c343ee1cc9810eb41f869c022daeeed5;hb=ffeaef854d80445ef87f2cdf4fe71d60347a81bf;hp=914b3c3f36769adbceddc588ac3ab34ca8e34a97;hpb=06e79b0783d6e9962ca6b2a25f62d46f46fa5c8b;p=vchess.git

diff --git a/client/src/components/Board.vue b/client/src/components/Board.vue
index 914b3c3f..7f2e43e4 100644
--- a/client/src/components/Board.vue
+++ b/client/src/components/Board.vue
@@ -1,157 +1,198 @@
 <script>
 import { getSquareId, getSquareFromId } from "@/utils/squareId";
 import { ArrayFun } from "@/utils/array";
-
+import { store } from "@/store";
 export default {
-  name: 'my-board',
-  // Last move cannot be guessed from here, and is required to highlight squares
+  name: "my-board",
+  // Last move cannot be guessed from here, and is required for highlights.
   // vr: object to check moves, print board...
   // userColor is left undefined for an external observer
-  props: ["vr","lastMove","analyze","orientation","userColor","vname"],
-  data: function () {
+  props: [
+    "vr",
+    "lastMove",
+    "analyze",
+    "score",
+    "incheck",
+    "orientation",
+    "userColor",
+    "vname"
+  ],
+  data: function() {
     return {
-      hints: (!localStorage["hints"] ? true : localStorage["hints"] === "1"),
-      bcolor: localStorage["bcolor"] || "lichess", //lichess, chesscom or chesstempo
+      mobileBrowser: ("ontouchstart" in window),
       possibleMoves: [], //filled after each valid click/dragstart
       choices: [], //promotion pieces, or checkered captures... (as moves)
+      containerPos: null,
       selectedPiece: null, //moving piece (or clicked piece)
-      incheck: [],
-      start: {}, //pixels coordinates + id of starting square (click or drag)
+      start: null, //pixels coordinates + id of starting square (click or drag)
+      startArrow: null,
+      movingArrow: null,
+      arrows: [], //object of {start: x,y / end: x,y}
+      circles: {}, //object of squares' ID --> true (TODO: use a set?)
+      click: "",
+      clickTime: 0,
+      settings: store.state.settings
     };
   },
   render(h) {
-    if (!this.vr)
-      return;
-    const [sizeX,sizeY] = [V.size.x,V.size.y];
+    if (!this.vr) {
+      // Return empty div of class 'game' to avoid error when setting size
+      return h(
+        "div",
+        { "class": { game: true } }
+      );
+    }
+    const [sizeX, sizeY] = [V.size.x, V.size.y];
     // Precompute hints squares to facilitate rendering
     let hintSquares = ArrayFun.init(sizeX, sizeY, false);
-    this.possibleMoves.forEach(m => { hintSquares[m.end.x][m.end.y] = true; });
+    this.possibleMoves.forEach(m => {
+      hintSquares[m.end.x][m.end.y] = true;
+    });
     // Also precompute in-check squares
     let incheckSq = ArrayFun.init(sizeX, sizeY, false);
-    this.incheck.forEach(sq => { incheckSq[sq[0]][sq[1]] = true; });
+    this.incheck.forEach(sq => {
+      incheckSq[sq[0]][sq[1]] = true;
+    });
 
-    let firstRow = document.querySelector(".game > .row");
-    const squareWidth = (!!firstRow
-      ? document.querySelector(".game > .row").offsetWidth / sizeY
-      : 40); //arbitrary value (not relevant)
-    const choices = h(
-      'div',
-      {
-        attrs: { "id": "choices" },
-        'class': { 'row': true },
-        style: {
-          "display": (this.choices.length > 0 ? "block" : "none"),
-          "top": ((sizeY/2)*squareWidth+squareWidth/2) + "px",
-          "width": (this.choices.length * squareWidth) + "px",
-          "height": squareWidth + "px",
-        },
-      },
-      this.choices.map(m => { //a "choice" is a move
-        return h('div',
-          {
-            'class': {
-              'board': true,
-              ['board'+sizeY]: true,
-            },
-            style: {
-              'width': (100/this.choices.length) + "%",
-              'padding-bottom': (100/this.choices.length) + "%",
-            },
-          },
-          [h('img',
-            {
-              attrs: { "src": '/images/pieces/' +
-                V.getPpath(m.appear[0].c+m.appear[0].p) + '.svg' },
-              'class': { 'choice-piece': true },
-              on: {
-                "click": e => { this.play(m); this.choices=[]; },
-                // NOTE: add 'touchstart' event to fix a problem on smartphones
-                "touchstart": e => { this.play(m); this.choices=[]; },
-              },
-            })
-          ]
-        );
-      })
+    let lm = this.lastMove;
+    // Precompute lastMove highlighting squares
+    const lmHighlights = {};
+    if (!!lm) {
+      if (!Array.isArray(lm)) lm = [lm];
+      lm.forEach(m => {
+        if (V.OnBoard(m.start.x, m.start.y))
+          lmHighlights[m.start.x + sizeX * m.start.y] = true;
+        if (V.OnBoard(m.end.x, m.end.y))
+          lmHighlights[m.end.x + sizeX * m.end.y] = true;
+      });
+    }
+    const showLight = (
+      this.settings.highlight &&
+      ["all","highlight"].includes(V.ShowMoves)
+    );
+    const showCheck = (
+      this.settings.highlight &&
+      ["all","highlight","byrow"].includes(V.ShowMoves)
     );
-    // Create board element (+ reserves if needed by variant or mode)
-    const lm = this.lastMove;
-    const showLight = this.hints && this.vname != "Dark";
+    const orientation = !V.CanFlip ? "w" : this.orientation;
+    // Ensure that squares colors do not change when board is flipped
+    const lightSquareMod = (sizeX + sizeY) % 2;
+    const showPiece = (x, y) => {
+      return (
+        this.vr.board[x][y] != V.EMPTY &&
+        (!this.vr.enlightened || this.analyze || this.score != "*" ||
+          (!!this.userColor && this.vr.enlightened[this.userColor][x][y]))
+      );
+    };
+    const inHighlight = (x, y) => {
+      return showLight && !!lmHighlights[x + sizeX * y];
+    };
+    const inShadow = (x, y) => {
+      return (
+        !this.analyze &&
+        this.score == "*" &&
+        this.vr.enlightened &&
+        (!this.userColor || !this.vr.enlightened[this.userColor][x][y])
+      );
+    };
+    // Create board element (+ reserves if needed by variant)
+    let elementArray = [];
     const gameDiv = h(
-      'div',
+      "div",
       {
-        'class': {
-          'game': true,
-          'clearer': true,
-        },
+        attrs: { id: "gamePosition" },
+        "class": {
+          game: true,
+          clearer: true
+        }
       },
       [...Array(sizeX).keys()].map(i => {
-        let ci = (this.orientation=='w' ? i : sizeX-i-1);
+        const ci = orientation == "w" ? i : sizeX - i - 1;
         return h(
-          'div',
+          "div",
           {
-            'class': {
-              'row': true,
+            "class": {
+              row: true
             },
-            style: { 'opacity': this.choices.length>0?"0.5":"1" },
+            style: { opacity: this.choices.length > 0 ? "0.5" : "1" }
           },
           [...Array(sizeY).keys()].map(j => {
-            let cj = (this.orientation=='w' ? j : sizeY-j-1);
+            const cj = orientation == "w" ? j : sizeY - j - 1;
+            const squareId = "sq-" + ci + "-" + cj;
             let elems = [];
-            if (this.vr.board[ci][cj] != V.EMPTY && (this.vname!="Dark"
-              || this.analyze || (!!this.userColor
-                && this.vr.enlightened[this.userColor][ci][cj])))
-            {
+            if (showPiece(ci, cj)) {
+              let pieceSpecs = {
+                "class": {
+                  piece: true,
+                  ghost:
+                    !!this.selectedPiece &&
+                    this.selectedPiece.parentNode.id == squareId
+                },
+                attrs: {
+                  src:
+                    "/images/pieces/" +
+                    this.vr.getPpath(
+                      this.vr.board[ci][cj],
+                      // Extra args useful for some variants:
+                      this.userColor,
+                      this.score,
+                      this.orientation) +
+                    V.IMAGE_EXTENSION
+                }
+              };
+              if (this.arrows.length == 0)
+                pieceSpecs["style"] = { position: "absolute" };
+              elems.push(h("img", pieceSpecs));
+            }
+            if (this.settings.hints && hintSquares[ci][cj]) {
               elems.push(
-                h(
-                  'img',
-                  {
-                    'class': {
-                      'piece': true,
-                      'ghost': !!this.selectedPiece
-                        && this.selectedPiece.parentNode.id == "sq-"+ci+"-"+cj,
-                    },
-                    attrs: {
-                      src: "/images/pieces/" +
-                        V.getPpath(this.vr.board[ci][cj]) + ".svg",
-                    },
+                h("img", {
+                  "class": {
+                    "mark-square": true
+                  },
+                  attrs: {
+                    src: "/images/mark.svg"
                   }
-                )
+                })
               );
             }
-            if (this.hints && hintSquares[ci][cj])
-            {
+            if (!!this.circles[squareId]) {
               elems.push(
-                h(
-                  'img',
-                  {
-                    'class': {
-                      'mark-square': true,
-                    },
-                    attrs: {
-                      src: "/images/mark.svg",
-                    },
+                h("img", {
+                  "class": {
+                    "circle-square": true
+                  },
+                  attrs: {
+                    src: "/images/circle.svg"
                   }
-                )
+                })
               );
             }
+            const lightSquare = (ci + cj) % 2 == lightSquareMod;
             return h(
-              'div',
+              "div",
               {
-                'class': {
-                  'board': true,
-                  ['board'+sizeY]: true,
-                  'light-square': (i+j)%2==0,
-                  'dark-square': (i+j)%2==1,
-                  [this.bcolor]: true,
-                  'in-shadow': this.vname=="Dark" && !this.analyze
-                    && (!this.userColor
-                      || !this.vr.enlightened[this.userColor][ci][cj]),
-                  'highlight': showLight && !!lm && lm.end.x == ci && lm.end.y == cj,
-                  'incheck': showLight && incheckSq[ci][cj],
+                "class": {
+                  board: true,
+                  ["board" + sizeY]: true,
+                  "light-square":
+                    !V.Notoodark && lightSquare && !V.Monochrome,
+                  "dark-square":
+                    !V.Notoodark && (!lightSquare || !!V.Monochrome),
+                  "middle-square": V.Notoodark,
+                  [this.settings.bcolor]: true,
+                  "in-shadow": inShadow(ci, cj),
+                  "highlight-light": inHighlight(ci, cj) && lightSquare,
+                  "highlight-dark":
+                    inHighlight(ci, cj) && (V.Monochrome || !lightSquare),
+                  "incheck-light":
+                    showCheck && lightSquare && incheckSq[ci][cj],
+                  "incheck-dark":
+                    showCheck && !lightSquare && incheckSq[ci][cj]
                 },
                 attrs: {
-                  id: getSquareId({x:ci,y:cj}),
-                },
+                  id: getSquareId({ x: ci, y: cj })
+                }
               },
               elems
             );
@@ -159,244 +200,683 @@ export default {
         );
       })
     );
-    const playingColor = this.userColor || "w"; //default for an observer
-    let elementArray = [choices, gameDiv];
-    if (!!this.vr.reserve)
-    {
-      const shiftIdx = (playingColor=="w" ? 0 : 1);
+    if (!!this.vr.reserve) {
+      const playingColor = this.userColor || "w"; //default for an observer
+      const shiftIdx = playingColor == "w" ? 0 : 1;
+      // Some variants have more than sizeY reserve pieces (Clorange: 10)
+      const reserveSquareNb = Math.max(sizeY, V.RESERVE_PIECES.length);
       let myReservePiecesArray = [];
-      for (let i=0; i<V.RESERVE_PIECES.length; i++)
-      {
-        myReservePiecesArray.push(h('div',
-        {
-          'class': {'board':true, ['board'+sizeY]:true},
-          attrs: { id: getSquareId({x:sizeX+shiftIdx,y:i}) }
-        },
-        [
-          h('img',
-          {
-            'class': {"piece":true, "reserve":true},
-            attrs: {
-              "src": "/images/pieces/" +
-                this.vr.getReservePpath(playingColor,i) + ".svg",
-            }
-          }),
-          h('sup',
-            {"class": { "reserve-count": true } },
-            [ this.vr.reserve[playingColor][V.RESERVE_PIECES[i]] ]
+      for (let i = 0; i < V.RESERVE_PIECES.length; i++) {
+        const qty = this.vr.reserve[playingColor][V.RESERVE_PIECES[i]];
+        myReservePiecesArray.push(
+          h(
+            "div",
+            {
+              "class": { board: true, ["board" + reserveSquareNb]: true },
+              attrs: { id: getSquareId({ x: sizeX + shiftIdx, y: i }) },
+              style: { opacity: qty > 0 ? 1 : 0.35 }
+            },
+            [
+              h("img", {
+                // NOTE: class "reserve" not used currently
+                "class": { piece: true, reserve: true },
+                attrs: {
+                  src:
+                    "/images/pieces/" +
+                    this.vr.getReservePpath(i, playingColor, orientation) +
+                    ".svg"
+                }
+              }),
+              h(
+                "sup",
+                {
+                  "class": { "reserve-count": true },
+                  style: { top: "calc(100% + 5px)" }
+                },
+                [ qty ]
+              )
+            ]
           )
-        ]));
+        );
       }
       let oppReservePiecesArray = [];
       const oppCol = V.GetOppCol(playingColor);
-      for (let i=0; i<V.RESERVE_PIECES.length; i++)
-      {
-        oppReservePiecesArray.push(h('div',
-        {
-          'class': {'board':true, ['board'+sizeY]:true},
-          attrs: { id: getSquareId({x:sizeX+(1-shiftIdx),y:i}) }
-        },
-        [
-          h('img',
+      for (let i = 0; i < V.RESERVE_PIECES.length; i++) {
+        const qty = this.vr.reserve[oppCol][V.RESERVE_PIECES[i]];
+        oppReservePiecesArray.push(
+          h(
+            "div",
+            {
+              "class": { board: true, ["board" + reserveSquareNb]: true },
+              attrs: { id: getSquareId({ x: sizeX + (1 - shiftIdx), y: i }) },
+              style: { opacity: qty > 0 ? 1 : 0.35 }
+            },
+            [
+              h("img", {
+                "class": { piece: true, reserve: true },
+                attrs: {
+                  src:
+                    "/images/pieces/" +
+                    this.vr.getReservePpath(i, oppCol, orientation) +
+                    ".svg"
+                }
+              }),
+              h(
+                "sup",
+                {
+                  "class": { "reserve-count": true },
+                  style: { top: "calc(100% + 5px)" }
+                },
+                [ qty ]
+              )
+            ]
+          )
+        );
+      }
+      const myReserveTop = (
+        (playingColor == 'w' && orientation == 'b') ||
+        (playingColor == 'b' && orientation == 'w')
+      );
+      // Center reserves, assuming same number of pieces for each side:
+      const nbReservePieces = myReservePiecesArray.length;
+      const marginLeft =
+        ((100 - nbReservePieces * (100 / reserveSquareNb)) / 2) + "%";
+      const reserveTop =
+        h(
+          "div",
+          {
+            "class": {
+              game: true,
+              "reserve-div": true
+            },
+            style: {
+              "margin-left": marginLeft
+            }
+          },
+          [
+            h(
+              "div",
+              {
+                "class": {
+                  row: true,
+                  "reserve-row": true
+                }
+              },
+              myReserveTop ? myReservePiecesArray : oppReservePiecesArray
+            )
+          ]
+        );
+      var reserveBottom =
+        h(
+          "div",
           {
-            'class': {"piece":true, "reserve":true},
-            attrs: {
-              "src": "/images/pieces/" +
-                this.vr.getReservePpath(oppCol,i) + ".svg",
+            "class": {
+              game: true,
+              "reserve-div": true
+            },
+            style: {
+              "margin-left": marginLeft
             }
-          }),
-          h('sup',
-            {"class": { "reserve-count": true } },
-            [ this.vr.reserve[oppCol][V.RESERVE_PIECES[i]] ]
-          )
-        ]));
+          },
+          [
+            h(
+              "div",
+              {
+                "class": {
+                  row: true,
+                  "reserve-row": true
+                }
+              },
+              myReserveTop ? oppReservePiecesArray : myReservePiecesArray
+            )
+          ]
+        );
+      elementArray.push(reserveTop);
+    }
+    elementArray.push(gameDiv);
+    if (!!this.vr.reserve) elementArray.push(reserveBottom);
+    const boardElt = document.getElementById("gamePosition");
+    // boardElt might be undefine (at first drawing)
+    if (this.choices.length > 0 && !!boardElt) {
+      const squareWidth = boardElt.offsetWidth / sizeY;
+      const offset = [boardElt.offsetTop, boardElt.offsetLeft];
+      const maxNbeltsPerRow = Math.min(this.choices.length, sizeY);
+      let topOffset = offset[0] + (sizeY / 2) * squareWidth - squareWidth / 2;
+      let choicesHeight = squareWidth;
+      if (this.choices.length >= sizeY) {
+        // A second row is required (Eightpieces variant)
+        topOffset -= squareWidth / 2;
+        choicesHeight *= 2;
       }
-      let reserves = h('div',
+      const choices = h(
+        "div",
         {
-          'class':{
-            'game': true,
-            "reserve-div": true,
-          },
+          attrs: { id: "choices" },
+          "class": { row: true },
+          style: {
+            top: topOffset + "px",
+            left:
+              offset[1] +
+              (squareWidth * Math.max(sizeY - this.choices.length, 0)) / 2 +
+              "px",
+            width: (maxNbeltsPerRow * squareWidth) + "px",
+            height: choicesHeight + "px"
+          }
         },
-        [
-          h('div',
-            {
-              'class': {
-                'row': true,
-                "reserve-row-1": true,
+        [ h(
+          "div",
+          {
+            "class": { "full-width": true }
+          },
+          this.choices.map(m => {
+            // A "choice" is a move
+            const applyMove = (e) => {
+              e.stopPropagation();
+              // Force a delay between move is shown and clicked
+              // (otherwise a "double-click" bug might occur)
+              if (Date.now() - this.clickTime < 200) return;
+              this.choices = [];
+              this.play(m);
+            };
+            const onClick =
+              this.mobileBrowser
+                ? { touchend: applyMove }
+                : { mouseup: applyMove };
+            return h(
+              "div",
+              {
+                "class": {
+                  board: true,
+                  ["board" + sizeY]: true
+                },
+                style: {
+                  width: (100 / maxNbeltsPerRow) + "%",
+                  "padding-bottom": (100 / maxNbeltsPerRow) + "%"
+                }
               },
-            },
-            myReservePiecesArray
-          ),
-          h('div',
-            { 'class': { 'row': true }},
-            oppReservePiecesArray
-          )
-        ]
+              [
+                h("img", {
+                  attrs: {
+                    src:
+                      "/images/pieces/" +
+                      // orientation: extra arg useful for some variants:
+                      this.vr.getPPpath(m, this.orientation) +
+                      V.IMAGE_EXTENSION
+                  },
+                  "class": { "choice-piece": true },
+                  on: onClick
+                })
+              ]
+            );
+          })
+        ) ]
       );
-      elementArray.push(reserves);
+      elementArray.unshift(choices);
     }
-    return h(
-      'div',
-      {
-        // NOTE: click = mousedown + mouseup
+    let onEvents = {};
+    // NOTE: click = mousedown + mouseup
+    if (this.mobileBrowser) {
+      onEvents = {
+        on: {
+          touchstart: this.mousedown,
+          touchmove: this.mousemove,
+          touchend: this.mouseup
+        }
+      };
+    } else {
+      onEvents = {
         on: {
           mousedown: this.mousedown,
           mousemove: this.mousemove,
           mouseup: this.mouseup,
-          touchstart: this.mousedown,
-          touchmove: this.mousemove,
-          touchend: this.mouseup,
-        },
-      },
-      elementArray
+          contextmenu: this.blockContextMenu
+        }
+      };
+    }
+    return (
+      h(
+        "div",
+        Object.assign({ attrs: { id: "rootBoardElement" } }, onEvents),
+        elementArray
+      )
     );
   },
+  updated: function() {
+    this.re_setDrawings();
+  },
   methods: {
+    blockContextMenu: function(e) {
+      e.preventDefault();
+      e.stopPropagation();
+      return false;
+    },
+    cancelResetArrows: function() {
+      this.startArrow = null;
+      this.arrows = [];
+      this.circles = {};
+      const curCanvas = document.getElementById("arrowCanvas");
+      if (!!curCanvas) curCanvas.parentNode.removeChild(curCanvas);
+    },
+    coordsToXY: function(coords, top, left, squareWidth) {
+      return {
+        // [1] for x and [0] for y because conventions in rules are inversed.
+        x: (
+          left + window.scrollX +
+          (
+            squareWidth *
+            (this.orientation == 'w' ? coords[1] : (V.size.y - coords[1]))
+          )
+        ),
+        y: (
+          top + window.scrollY +
+          (
+            squareWidth *
+            (this.orientation == 'w' ? coords[0] : (V.size.x - coords[0]))
+          )
+        )
+      };
+    },
+    computeEndArrow: function(start, end, top, left, squareWidth) {
+      const endCoords = this.coordsToXY(end, top, left, squareWidth);
+      const delta = [endCoords.x - start.x, endCoords.y - start.y];
+      const dist = Math.sqrt(delta[0] * delta[0] + delta[1] * delta[1]);
+      // Simple heuristic for now, just remove 1/3 square.
+      // TODO: should depend on the orientation.
+      const fracSqWidth = squareWidth / 3;
+      return {
+        x: endCoords.x - delta[0] * fracSqWidth / dist,
+        y: endCoords.y - delta[1] * fracSqWidth / dist
+      };
+    },
+    drawCurrentArrow: function() {
+      const boardElt = document.getElementById("gamePosition");
+      const squareWidth = boardElt.offsetWidth / V.size.y;
+      const bPos = boardElt.getBoundingClientRect();
+      const aStart =
+        this.coordsToXY(
+          [this.startArrow[0] + 0.5, this.startArrow[1] + 0.5],
+          bPos.top, bPos.left, squareWidth);
+      const aEnd =
+        this.computeEndArrow(
+          aStart, [this.movingArrow[0] + 0.5, this.movingArrow[1] + 0.5],
+          bPos.top, bPos.left, squareWidth);
+      let currentArrow = document.getElementById("currentArrow");
+      const d =
+        "M" + aStart.x + "," + aStart.y + " " + "L" + aEnd.x + "," + aEnd.y;
+      const arrowWidth = squareWidth / 4;
+      if (!!currentArrow) currentArrow.setAttribute("d", d);
+      else {
+        let domArrow =
+          document.createElementNS("http://www.w3.org/2000/svg", "path");
+        domArrow.classList.add("svg-arrow");
+        domArrow.id = "currentArrow";
+        domArrow.setAttribute("d", d);
+        domArrow.style = "stroke-width:" + arrowWidth + "px";
+        document.getElementById("arrowCanvas")
+          .insertAdjacentElement("beforeend", domArrow);
+      }
+    },
+    addArrow: function(arrow) {
+      this.arrows.push(arrow);
+      // Also add to DOM:
+      const boardElt = document.getElementById("gamePosition");
+      const squareWidth = boardElt.offsetWidth / V.size.y;
+      const bPos = boardElt.getBoundingClientRect();
+      const newArrow =
+        this.getSvgArrow(arrow, bPos.top, bPos.left, squareWidth);
+      document.getElementById("arrowCanvas")
+        .insertAdjacentElement("beforeend", newArrow);
+    },
+    getSvgArrow: function(arrow, top, left, squareWidth) {
+      const aStart =
+        this.coordsToXY(
+          [arrow.start[0] + 0.5, arrow.start[1] + 0.5],
+          top, left, squareWidth);
+      const aEnd =
+        this.computeEndArrow(
+          aStart, [arrow.end[0] + 0.5, arrow.end[1] + 0.5],
+          top, left, squareWidth);
+      const arrowWidth = squareWidth / 4;
+      let path =
+        document.createElementNS("http://www.w3.org/2000/svg", "path");
+      path.classList.add("svg-arrow");
+      path.setAttribute(
+        "d",
+        "M" + aStart.x + "," + aStart.y + " " + "L" + aEnd.x + "," + aEnd.y
+      );
+      path.style = "stroke-width:" + arrowWidth + "px";
+      return path;
+    },
+    re_setDrawings: function() {
+      // Remove current canvas, if any
+      const curCanvas = document.getElementById("arrowCanvas");
+      if (!!curCanvas) curCanvas.parentNode.removeChild(curCanvas);
+      // Add some drawing on board (for some variants + arrows and circles)
+      const boardElt = document.getElementById("gamePosition");
+      const squareWidth = boardElt.offsetWidth / V.size.y;
+      const bPos = boardElt.getBoundingClientRect();
+      let svgArrows = [];
+      this.arrows.forEach(a => {
+        svgArrows.push(this.getSvgArrow(a, bPos.top, bPos.left, squareWidth));
+      });
+      let vLines = [];
+      if (!!V.Lines) {
+        V.Lines.forEach(line => {
+          const lStart =
+            this.coordsToXY(line[0], bPos.top, bPos.left, squareWidth);
+          const lEnd =
+            this.coordsToXY(line[1], bPos.top, bPos.left, squareWidth);
+          let path =
+            document.createElementNS("http://www.w3.org/2000/svg", "path");
+          path.classList.add("svg-line");
+          path.setAttribute(
+            "d",
+            "M" + lStart.x + "," + lStart.y + " " +
+              "L" + lEnd.x + "," + lEnd.y
+          );
+          vLines.push(path);
+        });
+      }
+      let arrowCanvas =
+        document.createElementNS("http://www.w3.org/2000/svg", "svg");
+      arrowCanvas.id = "arrowCanvas";
+      arrowCanvas.setAttribute("stroke", "none");
+      let defs =
+        document.createElementNS("http://www.w3.org/2000/svg", "defs");
+      const arrowWidth = squareWidth / 4;
+      let marker =
+        document.createElementNS("http://www.w3.org/2000/svg", "marker");
+      marker.id = "arrow";
+      marker.setAttribute("markerWidth", (2 * arrowWidth) + "px");
+      marker.setAttribute("markerHeight", (3 * arrowWidth) + "px");
+      marker.setAttribute("markerUnits", "userSpaceOnUse");
+      marker.setAttribute("refX", "0");
+      marker.setAttribute("refY", (1.5 * arrowWidth) + "px");
+      marker.setAttribute("orient", "auto");
+      let head =
+        document.createElementNS("http://www.w3.org/2000/svg", "path");
+      head.classList.add("arrow-head");
+      head.setAttribute(
+        "d",
+        "M0,0 L0," + (3 * arrowWidth) + " L" +
+          (2 * arrowWidth) + "," + (1.5 * arrowWidth) + " z"
+      );
+      marker.appendChild(head);
+      defs.appendChild(marker);
+      arrowCanvas.appendChild(defs);
+      svgArrows.concat(vLines).forEach(av => arrowCanvas.appendChild(av));
+      document.getElementById("rootBoardElement").appendChild(arrowCanvas);
+    },
     mousedown: function(e) {
-      e = e || window.event;
-      let ingame = false;
-      let elem = e.target;
-      while (!ingame && elem !== null)
-      {
-        if (elem.classList.contains("game"))
-        {
-          ingame = true;
-          break;
+      e.preventDefault();
+      if (!this.mobileBrowser && e.which != 3)
+        // Cancel current drawing and circles, if any
+        this.cancelResetArrows();
+      if (this.mobileBrowser || e.which == 1) {
+        // Mouse left button
+        if (!this.start) {
+          this.containerPos =
+            document.getElementById("boardContainer").getBoundingClientRect();
+          // NOTE: classList[0] is enough: 'piece' is the first assigned class
+          const withPiece = (e.target.classList[0] == "piece");
+          // Emit the click event which could be used by some variants
+          this.$emit(
+            "click-square",
+            getSquareFromId(withPiece ? e.target.parentNode.id : e.target.id)
+          );
+          // Start square must contain a piece.
+          if (!withPiece) return;
+          let parent = e.target.parentNode; //surrounding square
+          // Show possible moves if current player allowed to play
+          const startSquare = getSquareFromId(parent.id);
+          this.possibleMoves = [];
+          const color = this.analyze ? this.vr.turn : this.userColor;
+          if (this.vr.canIplay(color, startSquare))
+            this.possibleMoves = this.vr.getPossibleMovesFrom(startSquare);
+          // For potential drag'n drop, remember start coordinates
+          // (to center the piece on mouse cursor)
+          const rect = parent.getBoundingClientRect();
+          this.start = {
+            x: rect.x + rect.width / 2,
+            y: rect.y + rect.width / 2,
+            id: parent.id
+          };
+          // Add the moving piece to the board, just after current image
+          this.selectedPiece = e.target.cloneNode();
+          Object.assign(
+            this.selectedPiece.style,
+            {
+              position: "absolute",
+              top: 0,
+              display: "inline-block",
+              zIndex: 3000
+            }
+          );
+          parent.insertBefore(this.selectedPiece, e.target.nextSibling);
+        } else {
+          this.processMoveAttempt(e);
         }
-        elem = elem.parentElement;
-      }
-      if (!ingame) //let default behavior (click on button...)
-        return;
-      e.preventDefault(); //disable native drag & drop
-      if (!this.selectedPiece && e.target.classList.contains("piece"))
-      {
-        // Next few lines to center the piece on mouse cursor
-        let rect = e.target.parentNode.getBoundingClientRect();
-        this.start = {
-          x: rect.x + rect.width/2,
-          y: rect.y + rect.width/2,
-          id: e.target.parentNode.id
-        };
-        this.selectedPiece = e.target.cloneNode();
-        this.selectedPiece.style.position = "absolute";
-        this.selectedPiece.style.top = 0;
-        this.selectedPiece.style.display = "inline-block";
-        this.selectedPiece.style.zIndex = 3000;
-        const startSquare = getSquareFromId(e.target.parentNode.id);
-        this.possibleMoves = [];
-        const color = (this.analyze ? this.vr.turn : this.userColor);
-        if (this.vr.canIplay(color,startSquare))
-          this.possibleMoves = this.vr.getPossibleMovesFrom(startSquare);
-        // Next line add moving piece just after current image
-        // (required for Crazyhouse reserve)
-        e.target.parentNode.insertBefore(this.selectedPiece, e.target.nextSibling);
+      } else if (e.which == 3) {
+        // Mouse right button
+        this.containerPos =
+          document.getElementById("gamePosition").getBoundingClientRect();
+        let elem = e.target;
+        // Next loop because of potential marks
+        while (elem.tagName == "IMG") elem = elem.parentNode;
+        this.startArrow = getSquareFromId(elem.id);
       }
     },
     mousemove: function(e) {
-      if (!this.selectedPiece)
+      if (!this.selectedPiece && !this.startArrow) return;
+      // Cancel if off boardContainer
+      const [offsetX, offsetY] =
+        this.mobileBrowser
+          ?
+            [
+              e.changedTouches[0].pageX,
+              // TODO: fixing attempt for smartphones, removing window.scrollY
+              e.changedTouches[0].pageY - window.scrollY
+            ]
+          : [e.clientX, e.clientY];
+      if (
+        offsetX < this.containerPos.left ||
+        offsetX > this.containerPos.right ||
+        offsetY < this.containerPos.top ||
+        offsetY > this.containerPos.bottom
+      ) {
+        if (!!this.selectedPiece) {
+          this.selectedPiece.parentNode.removeChild(this.selectedPiece);
+          delete this.selectedPiece;
+          this.selectedPiece = null;
+          this.start = null;
+          this.possibleMoves = []; //in case of
+          this.click = "";
+          let selected = document.querySelector(".ghost");
+          if (!!selected) selected.classList.remove("ghost");
+        }
+        else {
+          this.startArrow = null;
+          this.movingArrow = null;
+          const currentArrow = document.getElementById("currentArrow");
+          if (!!currentArrow)
+            currentArrow.parentNode.removeChild(currentArrow);
+        }
         return;
-      e = e || window.event;
-      // If there is an active element, move it around
-      if (!!this.selectedPiece)
-      {
-        const [offsetX,offsetY] = !!e.clientX
-          ? [e.clientX,e.clientY] //desktop browser
-          : [e.changedTouches[0].pageX, e.changedTouches[0].pageY]; //smartphone
-        this.selectedPiece.style.left = (offsetX-this.start.x) + "px";
-        this.selectedPiece.style.top = (offsetY-this.start.y) + "px";
+      }
+      e.preventDefault();
+      if (!!this.selectedPiece) {
+        // There is an active element: move it around
+        Object.assign(
+          this.selectedPiece.style,
+          {
+            left: offsetX - this.start.x + "px",
+            top: offsetY - this.start.y + "px"
+          }
+        );
+      }
+      else {
+        let elem = e.target;
+        // Next loop because of potential marks
+        while (elem.tagName == "IMG") elem = elem.parentNode;
+        // To center the arrow in square:
+        const movingCoords = getSquareFromId(elem.id);
+        if (
+          movingCoords[0] != this.startArrow[0] ||
+          movingCoords[1] != this.startArrow[1]
+        ) {
+          this.movingArrow = movingCoords;
+          this.drawCurrentArrow();
+        }
       }
     },
     mouseup: function(e) {
-      if (!this.selectedPiece)
-        return;
-      e = e || window.event;
-      // Read drop target (or parentElement, parentNode... if type == "img")
-      this.selectedPiece.style.zIndex = -3000; //HACK to find square from final coords
-      const [offsetX,offsetY] = !!e.clientX
-        ? [e.clientX,e.clientY]
-        : [e.changedTouches[0].pageX, e.changedTouches[0].pageY];
+      e.preventDefault();
+      if (this.mobileBrowser || e.which == 1) {
+        if (!this.selectedPiece) return;
+        // Drag'n drop. Selected piece is no longer needed:
+        this.selectedPiece.parentNode.removeChild(this.selectedPiece);
+        delete this.selectedPiece;
+        this.selectedPiece = null;
+        this.processMoveAttempt(e);
+      } else if (e.which == 3) {
+        if (!this.startArrow) return;
+        // Mouse right button
+        this.movingArrow = null;
+        this.processArrowAttempt(e);
+      }
+    },
+    // Called by BaseGame after partially undoing multi-moves:
+    resetCurrentAttempt: function() {
+      this.possibleMoves = [];
+      this.start = null;
+      this.click = "";
+      this.selectedPiece = null;
+    },
+    processMoveAttempt: function(e) {
+      // Obtain the move from start and end squares
+      const [offsetX, offsetY] =
+        this.mobileBrowser
+          ?
+            [
+              e.changedTouches[0].pageX,
+              e.changedTouches[0].pageY - window.scrollY
+            ]
+          : [e.clientX, e.clientY];
       let landing = document.elementFromPoint(offsetX, offsetY);
-      this.selectedPiece.style.zIndex = 3000;
       // Next condition: classList.contains(piece) fails because of marks
-      while (landing.tagName == "IMG")
-        landing = landing.parentNode;
-      if (this.start.id == landing.id)
-      {
-        // A click: selectedPiece and possibleMoves are already filled
+      while (landing.tagName == "IMG") landing = landing.parentNode;
+      if (this.start.id == landing.id) {
+        if (this.click == landing.id) {
+          // Second click on same square: cancel current move
+          this.possibleMoves = [];
+          this.start = null;
+          this.click = "";
+        } else this.click = landing.id;
         return;
       }
-      // OK: process move attempt
+      this.start = null;
+      // OK: process move attempt, landing is a square node
       let endSquare = getSquareFromId(landing.id);
       let moves = this.findMatchingMoves(endSquare);
       this.possibleMoves = [];
-      if (moves.length > 1)
+      if (moves.length > 1) {
+        this.clickTime = Date.now();
         this.choices = moves;
-      else if (moves.length==1)
-        this.play(moves[0]);
-      // Else: impossible move
-      this.selectedPiece.parentNode.removeChild(this.selectedPiece);
-      delete this.selectedPiece;
-      this.selectedPiece = null;
+      } else if (moves.length == 1) this.play(moves[0]);
+      // else: forbidden move attempt
+    },
+    processArrowAttempt: function(e) {
+      // Obtain the arrow from start and end squares
+      const [offsetX, offsetY] = [e.clientX, e.clientY];
+      let landing = document.elementFromPoint(offsetX, offsetY);
+      // Next condition: classList.contains(piece) fails because of marks
+      while (landing.tagName == "IMG") landing = landing.parentNode;
+      const landingCoords = getSquareFromId(landing.id);
+      if (
+        this.startArrow[0] == landingCoords[0] &&
+        this.startArrow[1] == landingCoords[1]
+      ) {
+        // Draw (or erase) a circle
+        this.$set(this.circles, landing.id, !this.circles[landing.id]);
+      }
+      else {
+        // OK: add arrow, landing is a new square
+        const currentArrow = document.getElementById("currentArrow");
+        currentArrow.parentNode.removeChild(currentArrow);
+        this.addArrow({
+          start: this.startArrow,
+          end: landingCoords
+        });
+      }
+      this.startArrow = null;
     },
     findMatchingMoves: function(endSquare) {
       // Run through moves list and return the matching set (if promotions...)
-      let moves = [];
-      this.possibleMoves.forEach(function(m) {
-        if (endSquare[0] == m.end.x && endSquare[1] == m.end.y)
-          moves.push(m);
-      });
-      return moves;
+      return (
+        this.possibleMoves.filter(m => {
+          return (endSquare[0] == m.end.x && endSquare[1] == m.end.y);
+        })
+      );
     },
     play: function(move) {
-      this.$emit('play-move', move);
-    },
-  },
+      this.$emit("play-move", move);
+    }
+  }
 };
 </script>
 
 <style lang="sass">
-.game.reserve-div
-  margin-bottom: 18px
-
-.reserve-count
-  padding-left: 40%
+// SVG dynamically added, so not scoped
+#arrowCanvas
+  pointer-events: none
+  position: absolute
+  top: 0
+  left: 0
+  width: 100%
+  height: 100%
 
-.reserve-row-1
-  margin-bottom: 15px
+.svg-arrow
+  opacity: 0.65
+  stroke: #5f0e78
+  fill: none
+  marker-end: url(#arrow)
 
-// NOTE: no variants with reserve of size != 8
+.svg-line
+  stroke: black
 
-div.board
-  float: left
-  height: 0
-  display: inline-block
-  position: relative
+.arrow-head
+  fill: #5f0e78
+</style>
 
-div.board8
-  width: 12.5%
-  padding-bottom: 12.5%
+<style lang="sass" scoped>
+@import "@/styles/_board_squares_img.sass";
 
-div.board10
-  width: 10%
-  padding-bottom: 10%
+//.game.reserve-div
+  // TODO: would be cleaner to restrict width so that it doesn't overflow
+  // Commented out because pieces would disappear over the board otherwise:
+  //overflow: hidden
+.reserve-count
+  width: 100%
+  text-align: center
+  display: inline-block
+  position: absolute
+.reserve-row
+  margin-bottom: 15px
 
-div.board11
-  width: 9.09%
-  padding-bottom: 9.1%
+.full-width
+  width: 100%
 
 .game
-  width: #{'min(80vw, 500px)'}
-  margin: 0 auto
+  user-select: none
+  width: 100%
+  margin: 0
   .board
     cursor: pointer
-  @media screen and (max-width: 767px)
-    width: 100%
-    margin: 0
 
 #choices
-  margin: 0 auto 0 auto
-  position: relative
+  user-select: none
+  margin: 0
+  position: absolute
   z-index: 300
   overflow-y: inherit
   background-color: rgba(0,0,0,0)
@@ -410,48 +890,55 @@ div.board11
       height: auto
       display: block
 
-img.piece
-  width: 100%
-
-img.piece, img.mark-square
-  max-width: 100%
-  height: auto
-  display: block
-
-img.mark-square
-  opacity: 0.6
-  width: 76%
-  position: absolute
-  top: 12%
-  left: 12%
-  opacity: .7
-
 img.ghost
+  // NOTE: no need to set z-index here, since opacity is low
   position: absolute
-  opacity: 0.4
+  opacity: 0.5
   top: 0
 
-.highlight
-  background-color: #00cc66 !important
-
-.in-shadow
-  filter: brightness(50%)
-
-.incheck
-  background-color: #cc3300 !important
+.incheck-light
+  background-color: rgba(204, 51, 0, 0.7) !important
+.incheck-dark
+  background-color: rgba(204, 51, 0, 0.9) !important
 
 .light-square.lichess
-  background-color: #f0d9b5;
+  background-color: #f0d9b5
 .dark-square.lichess
-  background-color: #b58863;
+  background-color: #b58863
 
 .light-square.chesscom
-  background-color: #e5e5ca;
+  background-color: #e5e5ca
 .dark-square.chesscom
-  background-color: #6f8f57;
+  background-color: #6f8f57
 
 .light-square.chesstempo
-  background-color: #fdfdfd;
+  background-color: #dfdfdf
 .dark-square.chesstempo
-  background-color: #88a0a8;
+  background-color: #7287b6
+
+.middle-square.lichess
+  background-color: #D3B18C
+
+.middle-square.chesscom
+  background-color: #AABA91
+
+.middle-square.chesstempo
+  background-color: #A9B3CB
+
+// TODO: no predefined highlight colors, but layers. How?
+
+.light-square.lichess.highlight-light
+  background-color: #cdd26a
+.dark-square.lichess.highlight-dark
+  background-color: #aaa23a
+
+.light-square.chesscom.highlight-light
+  background-color: #f7f783
+.dark-square.chesscom.highlight-dark
+  background-color: #bacb44
+
+.light-square.chesstempo.highlight-light
+  background-color: #9f9fff
+.dark-square.chesstempo.highlight-dark
+  background-color: #557fff
 </style>