client/src/components/Board.vue

   1 <script>
   2 import { getSquareId, getSquareFromId } from "@/utils/squareId";
   3 import { ArrayFun } from "@/utils/array";
   4 import { store } from "@/store";
   5 export default {
   6   name: "my-board",
   7   // Last move cannot be guessed from here, and is required for highlights.
   8   // vr: object to check moves, print board...
   9   // userColor is left undefined for an external observer
  10   props: [
  11     "vr",
  12     "lastMove",
  13     "analyze",
  14     "score",
  15     "incheck",
  16     "orientation",
  17     "userColor",
  18     "vname"
  19   ],
  20   data: function() {
  21     return {
  22       mobileBrowser: ("ontouchstart" in window),
  23       possibleMoves: [], //filled after each valid click/dragstart
  24       choices: [], //promotion pieces, or checkered captures... (as moves)
  25       selectedPiece: null, //moving piece (or clicked piece)
  26       start: null, //pixels coordinates + id of starting square (click or drag)
  27       startArrow: null,
  28       movingArrow: { x: -1, y: -1 },
  29       arrows: [], //object of {start: x,y / end: x,y}
  30       circles: {}, //object of squares' ID --> true (TODO: use a set?)
  31       click: "",
  32       clickTime: 0,
  33       settings: store.state.settings
  34     };
  35   },
  36   render(h) {
  37     if (!this.vr) {
  38       // Return empty div of class 'game' to avoid error when setting size
  39       return h("div", {
  40         class: {
  41           game: true
  42         }
  43       });
  44     }
  45     const [sizeX, sizeY] = [V.size.x, V.size.y];
  46     // Precompute hints squares to facilitate rendering
  47     let hintSquares = ArrayFun.init(sizeX, sizeY, false);
  48     this.possibleMoves.forEach(m => {
  49       hintSquares[m.end.x][m.end.y] = true;
  50     });
  51     // Also precompute in-check squares
  52     let incheckSq = ArrayFun.init(sizeX, sizeY, false);
  53     this.incheck.forEach(sq => {
  54       incheckSq[sq[0]][sq[1]] = true;
  55     });
  56
  57     let lm = this.lastMove;
  58     // Precompute lastMove highlighting squares
  59     const lmHighlights = {};
  60     if (!!lm) {
  61       if (!Array.isArray(lm)) lm = [lm];
  62       lm.forEach(m => {
  63         if (V.OnBoard(m.start.x, m.start.y))
  64           lmHighlights[m.start.x + sizeX * m.start.y] = true;
  65         if (V.OnBoard(m.end.x, m.end.y))
  66           lmHighlights[m.end.x + sizeX * m.end.y] = true;
  67       });
  68     }
  69     const showLight = (
  70       this.settings.highlight &&
  71       ["all","highlight"].includes(V.ShowMoves)
  72     );
  73     const showCheck = (
  74       this.settings.highlight &&
  75       ["all","highlight","byrow"].includes(V.ShowMoves)
  76     );
  77     const orientation = !V.CanFlip ? "w" : this.orientation;
  78     // Ensure that squares colors do not change when board is flipped
  79     const lightSquareMod = (sizeX + sizeY) % 2;
  80     const showPiece = (x, y) => {
  81       return (
  82         this.vr.board[x][y] != V.EMPTY &&
  83         (!this.vr.enlightened || this.analyze || this.score != "*" ||
  84           (!!this.userColor && this.vr.enlightened[this.userColor][x][y]))
  85       );
  86     };
  87     const inHighlight = (x, y) => {
  88       return showLight && !!lmHighlights[x + sizeX * y];
  89     };
  90     const inShadow = (x, y) => {
  91       return (
  92         !this.analyze &&
  93         this.score == "*" &&
  94         this.vr.enlightened &&
  95         (!this.userColor || !this.vr.enlightened[this.userColor][x][y])
  96       );
  97     };
  98     // Create board element (+ reserves if needed by variant)
  99     let elementArray = [];
 100     const gameDiv = h(
 101       "div",
 102       {
 103         "class": {
 104           game: true,
 105           clearer: true
 106         }
 107       },
 108       [...Array(sizeX).keys()].map(i => {
 109         const ci = orientation == "w" ? i : sizeX - i - 1;
 110         return h(
 111           "div",
 112           {
 113             "class": {
 114               row: true
 115             },
 116             style: { opacity: this.choices.length > 0 ? "0.5" : "1" }
 117           },
 118           [...Array(sizeY).keys()].map(j => {
 119             const cj = orientation == "w" ? j : sizeY - j - 1;
 120             const squareId = "sq-" + ci + "-" + cj;
 121             let elems = [];
 122             if (showPiece(ci, cj)) {
 123               elems.push(
 124                 h("img", {
 125                   "class": {
 126                     piece: true,
 127                     ghost:
 128                       !!this.selectedPiece &&
 129                       this.selectedPiece.parentNode.id == squareId
 130                   },
 131                   attrs: {
 132                     src:
 133                       "/images/pieces/" +
 134                       this.vr.getPpath(
 135                         this.vr.board[ci][cj],
 136                         // Extra args useful for some variants:
 137                         this.userColor,
 138                         this.score,
 139                         this.orientation) +
 140                       V.IMAGE_EXTENSION
 141                   }
 142                 })
 143               );
 144             }
 145             if (this.settings.hints && hintSquares[ci][cj]) {
 146               elems.push(
 147                 h("img", {
 148                   "class": {
 149                     "mark-square": true
 150                   },
 151                   attrs: {
 152                     src: "/images/mark.svg"
 153                   }
 154                 })
 155               );
 156             }
 157             if (!!this.circles[squareId]) {
 158               elems.push(
 159                 h("img", {
 160                   "class": {
 161                     "circle-square": true
 162                   },
 163                   attrs: {
 164                     src: "/images/circle.svg"
 165                   }
 166                 })
 167               );
 168             }
 169             const lightSquare = (ci + cj) % 2 == lightSquareMod;
 170             return h(
 171               "div",
 172               {
 173                 "class": {
 174                   board: true,
 175                   ["board" + sizeY]: true,
 176                   "light-square": lightSquare,
 177                   "dark-square": !lightSquare,
 178                   [this.settings.bcolor]: true,
 179                   "in-shadow": inShadow(ci, cj),
 180                   "highlight-light": inHighlight(ci, cj) && lightSquare,
 181                   "highlight-dark": inHighlight(ci, cj) && !lightSquare,
 182                   "incheck-light":
 183                     showCheck && lightSquare && incheckSq[ci][cj],
 184                   "incheck-dark":
 185                     showCheck && !lightSquare && incheckSq[ci][cj]
 186                 },
 187                 attrs: {
 188                   id: getSquareId({ x: ci, y: cj })
 189                 }
 190               },
 191               elems
 192             );
 193           })
 194         );
 195       })
 196     );
 197     if (!!this.vr.reserve) {
 198       const playingColor = this.userColor || "w"; //default for an observer
 199       const shiftIdx = playingColor == "w" ? 0 : 1;
 200       let myReservePiecesArray = [];
 201       for (let i = 0; i < V.RESERVE_PIECES.length; i++) {
 202         const qty = this.vr.reserve[playingColor][V.RESERVE_PIECES[i]];
 203         myReservePiecesArray.push(
 204           h(
 205             "div",
 206             {
 207               "class": { board: true, ["board" + sizeY]: true },
 208               attrs: { id: getSquareId({ x: sizeX + shiftIdx, y: i }) },
 209               style: { opacity: qty > 0 ? 1 : 0.35 }
 210             },
 211             [
 212               h("img", {
 213                 "class": { piece: true, reserve: true },
 214                 attrs: {
 215                   src:
 216                     "/images/pieces/" +
 217                     this.vr.getReservePpath(i, playingColor) +
 218                     ".svg"
 219                 }
 220               }),
 221               h("sup", { "class": { "reserve-count": true } }, [ qty ])
 222             ]
 223           )
 224         );
 225       }
 226       let oppReservePiecesArray = [];
 227       const oppCol = V.GetOppCol(playingColor);
 228       for (let i = 0; i < V.RESERVE_PIECES.length; i++) {
 229         const qty = this.vr.reserve[oppCol][V.RESERVE_PIECES[i]];
 230         oppReservePiecesArray.push(
 231           h(
 232             "div",
 233             {
 234               "class": { board: true, ["board" + sizeY]: true },
 235               attrs: { id: getSquareId({ x: sizeX + (1 - shiftIdx), y: i }) },
 236               style: { opacity: qty > 0 ? 1 : 0.35 }
 237             },
 238             [
 239               h("img", {
 240                 "class": { piece: true, reserve: true },
 241                 attrs: {
 242                   src:
 243                     "/images/pieces/" +
 244                     this.vr.getReservePpath(i, oppCol) +
 245                     ".svg"
 246                 }
 247               }),
 248               h("sup", { "class": { "reserve-count": true } }, [ qty ])
 249             ]
 250           )
 251         );
 252       }
 253       const myReserveTop = (
 254         (playingColor == 'w' && orientation == 'b') ||
 255         (playingColor == 'b' && orientation == 'w')
 256       );
 257       // Center reserves, assuming same number of pieces for each side:
 258       const nbReservePieces = myReservePiecesArray.length;
 259       const marginLeft = ((100 - nbReservePieces * (100 / sizeY)) / 2) + "%";
 260       const reserveTop =
 261         h(
 262           "div",
 263           {
 264             "class": {
 265               game: true,
 266               "reserve-div": true
 267             },
 268             style: {
 269               "margin-left": marginLeft
 270             }
 271           },
 272           [
 273             h(
 274               "div",
 275               {
 276                 "class": {
 277                   row: true,
 278                   "reserve-row": true
 279                 }
 280               },
 281               myReserveTop ? myReservePiecesArray : oppReservePiecesArray
 282             )
 283           ]
 284         );
 285       var reserveBottom =
 286         h(
 287           "div",
 288           {
 289             "class": {
 290               game: true,
 291               "reserve-div": true
 292             },
 293             style: {
 294               "margin-left": marginLeft
 295             }
 296           },
 297           [
 298             h(
 299               "div",
 300               {
 301                 "class": {
 302                   row: true,
 303                   "reserve-row": true
 304                 }
 305               },
 306               myReserveTop ? oppReservePiecesArray : myReservePiecesArray
 307             )
 308           ]
 309         );
 310       elementArray.push(reserveTop);
 311     }
 312     elementArray.push(gameDiv);
 313     if (!!this.vr.reserve) elementArray.push(reserveBottom);
 314     const boardElt = document.querySelector(".game");
 315     // boardElt might be undefine (at first drawing),
 316     // but it won't be used in this case.
 317     const squareWidth = (!!boardElt ? boardElt.offsetWidth / sizeY : 42);
 318     if (this.choices.length > 0 && !!boardElt) {
 319       // No choices to show at first drawing
 320       const offset = [boardElt.offsetTop, boardElt.offsetLeft];
 321       const maxNbeltsPerRow = Math.min(this.choices.length, sizeY);
 322       let topOffset = offset[0] + (sizeY / 2) * squareWidth - squareWidth / 2;
 323       let choicesHeight = squareWidth;
 324       if (this.choices.length >= sizeY) {
 325         // A second row is required (Eightpieces variant)
 326         topOffset -= squareWidth / 2;
 327         choicesHeight *= 2;
 328       }
 329       const choices = h(
 330         "div",
 331         {
 332           attrs: { id: "choices" },
 333           "class": { row: true },
 334           style: {
 335             top: topOffset + "px",
 336             left:
 337               offset[1] +
 338               (squareWidth * Math.max(sizeY - this.choices.length, 0)) / 2 +
 339               "px",
 340             width: (maxNbeltsPerRow * squareWidth) + "px",
 341             height: choicesHeight + "px"
 342           }
 343         },
 344         [ h(
 345           "div",
 346           {
 347             "class": { "full-width": true }
 348           },
 349           this.choices.map(m => {
 350             // A "choice" is a move
 351             const applyMove = (e) => {
 352               e.stopPropagation();
 353               // Force a delay between move is shown and clicked
 354               // (otherwise a "double-click" bug might occur)
 355               if (Date.now() - this.clickTime < 200) return;
 356               this.choices = [];
 357               this.play(m);
 358             };
 359             const onClick =
 360               this.mobileBrowser
 361                 ? { touchend: applyMove }
 362                 : { mouseup: applyMove };
 363             return h(
 364               "div",
 365               {
 366                 "class": {
 367                   board: true,
 368                   ["board" + sizeY]: true
 369                 },
 370                 style: {
 371                   width: (100 / maxNbeltsPerRow) + "%",
 372                   "padding-bottom": (100 / maxNbeltsPerRow) + "%"
 373                 }
 374               },
 375               [
 376                 h("img", {
 377                   attrs: {
 378                     src:
 379                       "/images/pieces/" +
 380                       // orientation: extra arg useful for some variants:
 381                       this.vr.getPPpath(m, this.orientation) +
 382                       V.IMAGE_EXTENSION
 383                   },
 384                   "class": { "choice-piece": true },
 385                   on: onClick
 386                 })
 387               ]
 388             );
 389           })
 390         ) ]
 391       );
 392       elementArray.unshift(choices);
 393     }
 394     if (
 395       !this.mobileBrowser &&
 396       (this.arrows.length > 0 || this.movingArrow.x >= 0)
 397     ) {
 398       let svgArrows = [];
 399       const arrowWidth = squareWidth / 4;
 400       this.arrows.forEach(a => {
 401         const endPoint = this.adjustEndArrow(a.start, a.end, squareWidth);
 402         svgArrows.push(
 403           h(
 404             "path",
 405             {
 406               "class": { "svg-arrow": true },
 407               attrs: {
 408                 d: (
 409                   "M" + a.start.x + "," + a.start.y + " " +
 410                   "L" + endPoint.x + "," + endPoint.y
 411                 ),
 412                 style: "stroke-width:" + arrowWidth + "px"
 413               }
 414             }
 415           )
 416         );
 417       });
 418       if (this.movingArrow.x >= 0) {
 419         const endPoint =
 420           this.adjustEndArrow(this.startArrow, this.movingArrow, squareWidth);
 421         svgArrows.push(
 422           h(
 423             "path",
 424             {
 425               "class": { "svg-arrow": true },
 426               attrs: {
 427                 d: (
 428                   "M" + this.startArrow.x + "," + this.startArrow.y + " " +
 429                   "L" + endPoint.x + "," + endPoint.y
 430                 ),
 431                 style: "stroke-width:" + arrowWidth + "px"
 432               }
 433             }
 434           )
 435         );
 436       }
 437       // Add SVG element for drawing arrows
 438       elementArray.push(
 439         h(
 440           "svg",
 441           {
 442             attrs: {
 443               id: "arrowCanvas",
 444               stroke: "none"
 445             }
 446           },
 447           [
 448             h(
 449               "defs",
 450               {},
 451               [
 452                 h(
 453                   "marker",
 454                   {
 455                     attrs: {
 456                       id: "arrow",
 457                       markerWidth: (2 * arrowWidth) + "px",
 458                       markerHeight: (3 * arrowWidth) + "px",
 459                       markerUnits: "userSpaceOnUse",
 460                       refX: "0",
 461                       refY: (1.5 * arrowWidth) + "px",
 462                       orient: "auto"
 463                     }
 464                   },
 465                   [
 466                     h(
 467                       "path",
 468                       {
 469                         "class": { "arrow-head": true },
 470                         attrs: {
 471                           d: (
 472                             "M0,0 L0," + (3 * arrowWidth) + " L" +
 473                             (2 * arrowWidth) + "," + (1.5 * arrowWidth) + " z"
 474                           )
 475                         }
 476                       }
 477                     )
 478                   ]
 479                 )
 480               ]
 481             )
 482           ].concat(svgArrows)
 483         )
 484       );
 485     }
 486     let onEvents = {};
 487     // NOTE: click = mousedown + mouseup
 488     if (this.mobileBrowser) {
 489       onEvents = {
 490         on: {
 491           touchstart: this.mousedown,
 492           touchmove: this.mousemove,
 493           touchend: this.mouseup
 494         }
 495       };
 496     } else {
 497       onEvents = {
 498         on: {
 499           mousedown: this.mousedown,
 500           mousemove: this.mousemove,
 501           mouseup: this.mouseup,
 502           contextmenu: this.blockContextMenu
 503         }
 504       };
 505     }
 506     return h("div", onEvents, elementArray);
 507   },
 508   methods: {
 509     blockContextMenu: function(e) {
 510       e.preventDefault();
 511       e.stopPropagation();
 512       return false;
 513     },
 514     cancelResetArrows: function() {
 515       this.startArrow = null;
 516       this.arrows = [];
 517       this.circles = {};
 518     },
 519     adjustEndArrow: function(start, end, squareWidth) {
 520       // Simple heuristic for now, just remove 1/3 square.
 521       // TODO: should depend on the orientation.
 522       const delta = [end.x - start.x, end.y - start.y];
 523       const dist = Math.sqrt(delta[0] * delta[0] + delta[1] * delta[1]);
 524       const fracSqWidth = squareWidth / 3;
 525       return {
 526         x: end.x - delta[0] * fracSqWidth / dist,
 527         y: end.y - delta[1] * fracSqWidth / dist
 528       };
 529     },
 530     mousedown: function(e) {
 531       e.preventDefault();
 532       if (!this.mobileBrowser && e.which != 3)
 533         // Cancel current drawing and circles, if any
 534         this.cancelResetArrows();
 535       if (this.mobileBrowser || e.which == 1) {
 536         // Mouse left button
 537         if (!this.start) {
 538           // NOTE: classList[0] is enough: 'piece' is the first assigned class
 539           const withPiece = (e.target.classList[0] == "piece");
 540           // Emit the click event which could be used by some variants
 541           this.$emit(
 542             "click-square",
 543             getSquareFromId(withPiece ? e.target.parentNode.id : e.target.id)
 544           );
 545           // Start square must contain a piece.
 546           if (!withPiece) return;
 547           let parent = e.target.parentNode; //surrounding square
 548           // Show possible moves if current player allowed to play
 549           const startSquare = getSquareFromId(parent.id);
 550           this.possibleMoves = [];
 551           const color = this.analyze ? this.vr.turn : this.userColor;
 552           if (this.vr.canIplay(color, startSquare))
 553             this.possibleMoves = this.vr.getPossibleMovesFrom(startSquare);
 554           // For potential drag'n drop, remember start coordinates
 555           // (to center the piece on mouse cursor)
 556           const rect = parent.getBoundingClientRect();
 557           this.start = {
 558             x: rect.x + rect.width / 2,
 559             y: rect.y + rect.width / 2,
 560             id: parent.id
 561           };
 562           // Add the moving piece to the board, just after current image
 563           this.selectedPiece = e.target.cloneNode();
 564           Object.assign(
 565             this.selectedPiece.style,
 566             {
 567               position: "absolute",
 568               top: 0,
 569               display: "inline-block",
 570               zIndex: 3000
 571             }
 572           );
 573           parent.insertBefore(this.selectedPiece, e.target.nextSibling);
 574         } else {
 575           this.processMoveAttempt(e);
 576         }
 577       } else if (e.which == 3) {
 578         // Mouse right button
 579         let elem = e.target;
 580         // Next loop because of potential marks
 581         while (elem.tagName == "IMG") elem = elem.parentNode;
 582         // To center the arrow in square:
 583         const rect = elem.getBoundingClientRect();
 584         this.startArrow = {
 585           x: rect.x + rect.width / 2,
 586           y: rect.y + rect.width / 2,
 587           id: elem.id
 588         };
 589       }
 590     },
 591     mousemove: function(e) {
 592       if (!this.selectedPiece && !this.startArrow) return;
 593       e.preventDefault();
 594       if (!!this.selectedPiece) {
 595         // There is an active element: move it around
 596         const [offsetX, offsetY] =
 597           this.mobileBrowser
 598             ? [e.changedTouches[0].pageX, e.changedTouches[0].pageY]
 599             : [e.clientX, e.clientY];
 600         Object.assign(
 601           this.selectedPiece.style,
 602           {
 603             left: offsetX - this.start.x + "px",
 604             top: offsetY - this.start.y + "px"
 605           }
 606         );
 607       }
 608       else {
 609         let elem = e.target;
 610         // Next loop because of potential marks
 611         while (elem.tagName == "IMG") elem = elem.parentNode;
 612         // To center the arrow in square:
 613         if (elem.id != this.startArrow.id) {
 614           const rect = elem.getBoundingClientRect();
 615           this.movingArrow = {
 616             x: rect.x + rect.width / 2,
 617             y: rect.y + rect.width / 2
 618           };
 619         }
 620       }
 621     },
 622     mouseup: function(e) {
 623       e.preventDefault();
 624       if (this.mobileBrowser || e.which == 1) {
 625         if (!this.selectedPiece) return;
 626         // Drag'n drop. Selected piece is no longer needed:
 627         this.selectedPiece.parentNode.removeChild(this.selectedPiece);
 628         delete this.selectedPiece;
 629         this.selectedPiece = null;
 630         this.processMoveAttempt(e);
 631       } else if (e.which == 3) {
 632         // Mouse right button
 633         this.movingArrow = { x: -1, y: -1 };
 634         this.processArrowAttempt(e);
 635       }
 636     },
 637     // Called by BaseGame after partially undoing multi-moves:
 638     resetCurrentAttempt: function() {
 639       this.possibleMoves = [];
 640       this.start = null;
 641       this.click = "";
 642       this.selectedPiece = null;
 643     },
 644     processMoveAttempt: function(e) {
 645       // Obtain the move from start and end squares
 646       const [offsetX, offsetY] =
 647         this.mobileBrowser
 648           ? [e.changedTouches[0].pageX, e.changedTouches[0].pageY]
 649           : [e.clientX, e.clientY];
 650       let landing = document.elementFromPoint(offsetX, offsetY);
 651       // Next condition: classList.contains(piece) fails because of marks
 652       while (landing.tagName == "IMG") landing = landing.parentNode;
 653       if (this.start.id == landing.id) {
 654         if (this.click == landing.id) {
 655           // Second click on same square: cancel current move
 656           this.possibleMoves = [];
 657           this.start = null;
 658           this.click = "";
 659         } else this.click = landing.id;
 660         return;
 661       }
 662       this.start = null;
 663       // OK: process move attempt, landing is a square node
 664       let endSquare = getSquareFromId(landing.id);
 665       let moves = this.findMatchingMoves(endSquare);
 666       this.possibleMoves = [];
 667       if (moves.length > 1) {
 668         this.clickTime = Date.now();
 669         this.choices = moves;
 670       } else if (moves.length == 1) this.play(moves[0]);
 671       // else: forbidden move attempt
 672     },
 673     processArrowAttempt: function(e) {
 674       // Obtain the arrow from start and end squares
 675       const [offsetX, offsetY] = [e.clientX, e.clientY];
 676       let landing = document.elementFromPoint(offsetX, offsetY);
 677       // Next condition: classList.contains(piece) fails because of marks
 678       while (landing.tagName == "IMG") landing = landing.parentNode;
 679       if (this.startArrow.id == landing.id)
 680         // Draw (or erase) a circle
 681         this.$set(this.circles, landing.id, !this.circles[landing.id]);
 682       else {
 683         // OK: add arrow, landing is a new square
 684         const rect = landing.getBoundingClientRect();
 685         this.arrows.push({
 686           start: {
 687             x: this.startArrow.x,
 688             y: this.startArrow.y
 689           },
 690           end: {
 691             x: rect.x + rect.width / 2,
 692             y: rect.y + rect.width / 2
 693           }
 694         });
 695       }
 696       this.startArrow = null;
 697     },
 698     findMatchingMoves: function(endSquare) {
 699       // Run through moves list and return the matching set (if promotions...)
 700       return (
 701         this.possibleMoves.filter(m => {
 702           return (endSquare[0] == m.end.x && endSquare[1] == m.end.y);
 703         })
 704       );
 705     },
 706     play: function(move) {
 707       this.$emit("play-move", move);
 708     }
 709   }
 710 };
 711 </script>
 712
 713 <style lang="sass" scoped>
 714 @import "@/styles/_board_squares_img.sass";
 715
 716 // NOTE: no variants with reserve of size != 8
 717 .game.reserve-div
 718   margin-bottom: 18px
 719 .reserve-count
 720   padding-left: 40%
 721 .reserve-row
 722   margin-bottom: 15px
 723
 724 .full-width
 725   width: 100%
 726
 727 .game
 728   user-select: none
 729   width: 100%
 730   margin: 0
 731   .board
 732     cursor: pointer
 733
 734 #choices
 735   user-select: none
 736   margin: 0
 737   position: absolute
 738   z-index: 300
 739   overflow-y: inherit
 740   background-color: rgba(0,0,0,0)
 741   img
 742     cursor: pointer
 743     background-color: #e6ee9c
 744     &:hover
 745       background-color: skyblue
 746     &.choice-piece
 747       width: 100%
 748       height: auto
 749       display: block
 750
 751 img.ghost
 752   position: absolute
 753   opacity: 0.5
 754   top: 0
 755
 756 #arrowCanvas
 757   pointer-events: none
 758   position: absolute
 759   top: 0
 760   left: 0
 761   width: 100%
 762   height: 100%
 763
 764 .svg-arrow
 765   opacity: 0.65
 766   stroke: #5f0e78
 767   fill: none
 768   marker-end: url(#arrow)
 769
 770 .arrow-head
 771   fill: #5f0e78
 772
 773 .incheck-light
 774   background-color: rgba(204, 51, 0, 0.7) !important
 775 .incheck-dark
 776   background-color: rgba(204, 51, 0, 0.9) !important
 777
 778 .light-square.lichess
 779   background-color: #f0d9b5;
 780 .dark-square.lichess
 781   background-color: #b58863;
 782
 783 .light-square.chesscom
 784   background-color: #e5e5ca;
 785 .dark-square.chesscom
 786   background-color: #6f8f57;
 787
 788 .light-square.chesstempo
 789   background-color: #dfdfdf;
 790 .dark-square.chesstempo
 791   background-color: #7287b6;
 792
 793 // TODO: no predefined highlight colors, but layers. How?
 794
 795 .light-square.lichess.highlight-light
 796   background-color: #cdd26a
 797 .dark-square.lichess.highlight-dark
 798   background-color: #aaa23a
 799
 800 .light-square.chesscom.highlight-light
 801   background-color: #f7f783
 802 .dark-square.chesscom.highlight-dark
 803   background-color: #bacb44
 804
 805 .light-square.chesstempo.highlight-light
 806   background-color: #9f9fff
 807 .dark-square.chesstempo.highlight-dark
 808   background-color: #557fff
 809 </style>