X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=client%2Fsrc%2Fcomponents%2FBoard.vue;h=639938b2b4b14ead23db62715fe46f7c811be27e;hb=5f918a278904266a2a66a3c8e2a3655f37c2d2a7;hp=51632312d2dc473d52dc368dde0c57abefeb036c;hpb=24340cae41e916d91088cc6988d8838b342a9c42;p=vchess.git

diff --git a/client/src/components/Board.vue b/client/src/components/Board.vue
index 51632312..639938b2 100644
--- a/client/src/components/Board.vue
+++ b/client/src/components/Board.vue
@@ -1,153 +1,183 @@
 <script>
-// This can work for squared boards (2 or 4 players), with some adaptations (TODO)
-// TODO: for 3 players, write a "board3.js"
+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...
-  // mode: HH, HC or analyze
-  // userColor: for mode HH or HC
-  props: ["vr","lastMove","mode","orientation","userColor"],
-  data: function () {
+  // userColor is left undefined for an external observer
+  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)
       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: { x: -1, y: -1 },
+      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 = doubleArray(sizeX, sizeY, false);
-    this.possibleMoves.forEach(m => { hintSquares[m.end.x][m.end.y] = true; });
+    let hintSquares = ArrayFun.init(sizeX, sizeY, false);
+    this.possibleMoves.forEach(m => {
+      hintSquares[m.end.x][m.end.y] = true;
+    });
     // Also precompute in-check squares
-    let incheckSq = doubleArray(sizeX, sizeY, false);
-    this.incheck.forEach(sq => { incheckSq[sq[0]][sq[1]] = true; });
-    const squareWidth = 40; //TODO: compute this
-    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=[]; },
-              },
-            })
-          ]
-        );
-      })
-    );
-    // Create board element (+ reserves if needed by variant or mode)
+    let incheckSq = ArrayFun.init(sizeX, sizeY, false);
+    this.incheck.forEach(sq => {
+      incheckSq[sq[0]][sq[1]] = true;
+    });
+
     const lm = this.lastMove;
-    const showLight = this.hints && variant.name != "Dark";
+    const showLight = (
+      this.settings.highlight &&
+      ["all","highlight"].includes(V.ShowMoves)
+    );
+    const showCheck = (
+      this.settings.highlight &&
+      ["all","highlight","byrow"].includes(V.ShowMoves)
+    );
+    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 && !!lm && (
+        (lm.end.x == x && lm.end.y == y) ||
+        (lm.start.x == x && lm.start.y == 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,
-        },
+        "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 && (variant.name!="Dark"
-              || this.gameOver || this.mode == "analyze"
-              || this.vr.enlightened[this.userColor][ci][cj]))
-            {
+            if (showPiece(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": {
+                    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.hints && hintSquares[ci][cj])
-            {
+            if (this.settings.hints && hintSquares[ci][cj]) {
               elems.push(
-                h(
-                  'img',
-                  {
-                    'class': {
-                      'mark-square': true,
-                    },
-                    attrs: {
-                      src: "/images/mark.svg",
-                    },
+                h("img", {
+                  "class": {
+                    "mark-square": true
+                  },
+                  attrs: {
+                    src: "/images/mark.svg"
                   }
-                )
+                })
+              );
+            }
+            if (!!this.circles[squareId]) {
+              elems.push(
+                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': variant.name=="Dark" && !this.gameOver
-                    && this.mode != "analyze"
-                    && !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": lightSquare,
+                  "dark-square": !lightSquare,
+                  [this.settings.bcolor]: true,
+                  "in-shadow": inShadow(ci, cj),
+                  "highlight-light": inHighlight(ci, cj) && lightSquare,
+                  "highlight-dark": inHighlight(ci, cj) && !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
             );
@@ -155,206 +185,610 @@ export default {
         );
       })
     );
-    let elementArray = [choices, gameDiv];
-    if (!!this.vr.reserve)
-    {
-      const shiftIdx = (this.userColor=="w" ? 0 : 1);
+    if (!!this.vr.reserve) {
+      const playingColor = this.userColor || "w"; //default for an observer
+      const shiftIdx = playingColor == "w" ? 0 : 1;
       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(this.userColor,i) + ".svg",
-            }
-          }),
-          h('sup',
-            {"class": { "reserve-count": true } },
-            [ this.vr.reserve[this.userColor][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" + sizeY]: true },
+              attrs: { id: getSquareId({ x: sizeX + 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, playingColor) +
+                    ".svg"
+                }
+              }),
+              h("sup", { "class": { "reserve-count": true } }, [ qty ])
+            ]
           )
-        ]));
+        );
       }
       let oppReservePiecesArray = [];
-      const oppCol = V.GetOppCol(this.userColor);
-      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',
+      const oppCol = V.GetOppCol(playingColor);
+      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" + sizeY]: 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) +
+                    ".svg"
+                }
+              }),
+              h("sup", { "class": { "reserve-count": true } }, [ 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 / sizeY)) / 2) + "%";
+      const reserveTop =
+        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 ? myReservePiecesArray : oppReservePiecesArray
+            )
+          ]
+        );
+      var reserveBottom =
+        h(
+          "div",
+          {
+            "class": {
+              game: true,
+              "reserve-div": true
+            },
+            style: {
+              "margin-left": marginLeft
+            }
+          },
+          [
+            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.querySelector(".game");
+    // boardElt might be undefine (at first drawing),
+    // but it won't be used in this case.
+    const squareWidth = (!!boardElt ? boardElt.offsetWidth / sizeY : 42);
+    if (this.choices.length > 0 && !!boardElt) {
+      // No choices to show at first drawing
+      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.unshift(choices);
+    }
+    if (
+      !this.mobileBrowser &&
+      (this.arrows.length > 0 || this.movingArrow.x >= 0)
+    ) {
+      let svgArrows = [];
+      const arrowWidth = squareWidth / 4;
+      this.arrows.forEach(a => {
+        const endPoint = this.adjustEndArrow(a.start, a.end, squareWidth);
+        svgArrows.push(
+          h(
+            "path",
+            {
+              "class": { "svg-arrow": true },
+              attrs: {
+                d: (
+                  "M" + a.start.x + "," + a.start.y + " " +
+                  "L" + endPoint.x + "," + endPoint.y
+                ),
+                style: "stroke-width:" + arrowWidth + "px"
+              }
+            }
+          )
+        );
+      });
+      if (this.movingArrow.x >= 0) {
+        const endPoint =
+          this.adjustEndArrow(this.startArrow, this.movingArrow, squareWidth);
+        svgArrows.push(
+          h(
+            "path",
+            {
+              "class": { "svg-arrow": true },
+              attrs: {
+                d: (
+                  "M" + this.startArrow.x + "," + this.startArrow.y + " " +
+                  "L" + endPoint.x + "," + endPoint.y
+                ),
+                style: "stroke-width:" + arrowWidth + "px"
+              }
+            }
           )
-        ]
+        );
+      }
+      // Add SVG element for drawing arrows
+      elementArray.push(
+        h(
+          "svg",
+          {
+            attrs: {
+              id: "arrowCanvas",
+              stroke: "none"
+            }
+          },
+          [
+            h(
+              "defs",
+              {},
+              [
+                h(
+                  "marker",
+                  {
+                    attrs: {
+                      id: "arrow",
+                      markerWidth: (2 * arrowWidth) + "px",
+                      markerHeight: (3 * arrowWidth) + "px",
+                      markerUnits: "userSpaceOnUse",
+                      refX: "0",
+                      refY: (1.5 * arrowWidth) + "px",
+                      orient: "auto"
+                    }
+                  },
+                  [
+                    h(
+                      "path",
+                      {
+                        "class": { "arrow-head": true },
+                        attrs: {
+                          d: (
+                            "M0,0 L0," + (3 * arrowWidth) + " L" +
+                            (2 * arrowWidth) + "," + (1.5 * arrowWidth) + " z"
+                          )
+                        }
+                      }
+                    )
+                  ]
+                )
+              ]
+            )
+          ].concat(svgArrows)
+        )
       );
-      elementArray.push(reserves);
     }
-    return h(
-      'div',
-      {
-        'class': {
-          "col-sm-12":true,
-          "col-md-10":true,
-          "col-md-offset-1":true,
-          "col-lg-8":true,
-          "col-lg-offset-2":true,
-        },
-        // 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", onEvents, elementArray);
   },
   methods: {
+    blockContextMenu: function(e) {
+      e.preventDefault();
+      e.stopPropagation();
+      return false;
+    },
+    cancelResetArrows: function() {
+      this.startArrow = null;
+      this.arrows = [];
+      this.circles = {};
+    },
+    adjustEndArrow: function(start, end, squareWidth) {
+      // Simple heuristic for now, just remove 1/3 square.
+      // TODO: should depend on the orientation.
+      const delta = [end.x - start.x, end.y - start.y];
+      const dist = Math.sqrt(delta[0] * delta[0] + delta[1] * delta[1]);
+      const fracSqWidth = squareWidth / 3;
+      return {
+        x: end.x - delta[0] * fracSqWidth / dist,
+        y: end.y - delta[1] * fracSqWidth / dist
+      };
+    },
     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;
+      if (!([1, 3].includes(e.which))) return;
+      e.preventDefault();
+      if (e.which != 3)
+        // Cancel current drawing and circles, if any
+        this.cancelResetArrows();
+      if (e.which == 1 || this.mobileBrowser) {
+        // Mouse left button
+        if (!this.start) {
+          // 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
+      } else {
+        // e.which == 3 : mouse right button
+        let elem = e.target;
+        // Next loop because of potential marks
+        while (elem.tagName == "IMG") elem = elem.parentNode;
+        // To center the arrow in square:
+        const rect = elem.getBoundingClientRect();
+        this.startArrow = {
+          x: rect.x + rect.width / 2,
+          y: rect.y + rect.width / 2,
+          id: elem.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.mode=="analyze" || this.gameOver
-          ? 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);
       }
     },
     mousemove: function(e) {
-      if (!this.selectedPiece)
-        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";
+      if (!this.selectedPiece && !this.startArrow) return;
+      e.preventDefault();
+      if (!!this.selectedPiece) {
+        // There is an active element: move it around
+        const [offsetX, offsetY] =
+          this.mobileBrowser
+            ? [e.changedTouches[0].pageX, e.changedTouches[0].pageY]
+            : [e.clientX, e.clientY];
+        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:
+        if (elem.id != this.startArrow.id) {
+          const rect = elem.getBoundingClientRect();
+          this.movingArrow = {
+            x: rect.x + rect.width / 2,
+            y: rect.y + rect.width / 2
+          };
+        }
       }
     },
     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];
+      if (!([1, 3].includes(e.which))) return;
+      e.preventDefault();
+      if (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 {
+        // Mouse right button (e.which == 3)
+        this.movingArrow = { x: -1, y: -1 };
+        this.processArrowAttempt(e);
+      }
+    },
+    processMoveAttempt: function(e) {
+      // Obtain the move from start and end squares
+      const [offsetX, offsetY] =
+        this.mobileBrowser
+          ? [e.changedTouches[0].pageX, e.changedTouches[0].pageY]
+          : [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;
+      if (this.startArrow.id == landing.id)
+        // 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 rect = landing.getBoundingClientRect();
+        this.arrows.push({
+          start: {
+            x: this.startArrow.x,
+            y: this.startArrow.y
+          },
+          end: {
+            x: rect.x + rect.width / 2,
+            y: rect.y + rect.width / 2
+          }
+        });
+      }
+      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" scoped>
+// NOTE: no variants with reserve of size != 8
+.game.reserve-div
+  margin-bottom: 18px
+.reserve-count
+  padding-left: 40%
+.reserve-row
+  margin-bottom: 15px
+
+.full-width
+  width: 100%
+
+.game
+  user-select: none
+  width: 100%
+  margin: 0
+  .board
+    cursor: pointer
+
+#choices
+  user-select: none
+  margin: 0
+  position: absolute
+  z-index: 300
+  overflow-y: inherit
+  background-color: rgba(0,0,0,0)
+  img
+    cursor: pointer
+    background-color: #e6ee9c
+    &:hover
+      background-color: skyblue
+    &.choice-piece
+      width: 100%
+      height: auto
+      display: block
+
+img.ghost
+  position: absolute
+  opacity: 0.5
+  top: 0
+
+#arrowCanvas
+  pointer-events: none
+  position: absolute
+  top: 0
+  left: 0
+  width: 100%
+  height: 100%
+
+.svg-arrow
+  opacity: 0.65
+  stroke: #5f0e78
+  fill: none
+  marker-end: url(#arrow)
+
+.arrow-head
+  fill: #5f0e78
+
+.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;
+.dark-square.lichess
+  background-color: #b58863;
+
+.light-square.chesscom
+  background-color: #e5e5ca;
+.dark-square.chesscom
+  background-color: #6f8f57;
+
+.light-square.chesstempo
+  background-color: #dfdfdf;
+.dark-square.chesstempo
+  background-color: #7287b6;
+
+// 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>