public/javascripts/components/game.js

   1 Vue.component('my-game', {
   2     data: function() {
   3         return {
   4             vr: null, //object to check moves, store them, FEN..
   5             mycolor: "w",
   6             possibleMoves: [], //filled after each valid click/dragstart
   7             choices: [], //promotion pieces, or checkered captures... (contain possible pieces)
   8             start: {}, //pixels coordinates + id of starting square (click or drag)
   9             selectedPiece: null, //moving piece (or clicked piece)
  10             conn: null, //socket messages
  11             score: "*", //'*' means 'unfinished'
  12             mode: "idle", //human, computer or idle (when not playing)
  13             oppid: "", //opponent ID in case of HH game
  14             oppConnected: false,
  15             seek: false,
  16             fenStart: "",
  17             incheck: [],
  18             pgnTxt: "",
  19             expert: document.cookie.length>0 ? document.cookie.substr(-1)=="1" : false,
  20             gameId: "", //used to limit computer moves' time
  21         };
  22     },
  23     render(h) {
  24         const [sizeX,sizeY] = VariantRules.size;
  25         // Precompute hints squares to facilitate rendering
  26         let hintSquares = doubleArray(sizeX, sizeY, false);
  27         this.possibleMoves.forEach(m => { hintSquares[m.end.x][m.end.y] = true; });
  28         // Also precompute in-check squares
  29         let incheckSq = doubleArray(sizeX, sizeY, false);
  30         this.incheck.forEach(sq => { incheckSq[sq[0]][sq[1]] = true; });
  31         let elementArray = [];
  32         const playingHuman = (this.mode == "human");
  33         const playingComp = (this.mode == "computer");
  34         let actionArray = [
  35             h('button',
  36                 {
  37                     on: { click: this.clickGameSeek },
  38                     attrs: { "aria-label": 'New game VS human' },
  39                     'class': {
  40                         "tooltip": true,
  41                         "bottom": true, //display below
  42                         "seek": this.seek,
  43                         "playing": playingHuman,
  44                     },
  45                 },
  46                 [h('i', { 'class': { "material-icons": true } }, "accessibility")]),
  47             h('button',
  48                 {
  49                     on: { click: this.clickComputerGame },
  50                     attrs: { "aria-label": 'New game VS computer' },
  51                     'class': {
  52                         "tooltip":true,
  53                         "bottom": true,
  54                         "playing": playingComp,
  55                     },
  56                 },
  57                 [h('i', { 'class': { "material-icons": true } }, "computer")])
  58         ];
  59         if (!!this.vr)
  60         {
  61             const square00 = document.getElementById("sq-0-0");
  62             const squareWidth = !!square00
  63                 ? parseFloat(window.getComputedStyle(square00).width.slice(0,-2))
  64                 : 0;
  65             const indicWidth = (squareWidth>0 ? squareWidth/2 : 20);
  66             if (this.mode == "human")
  67             {
  68                 let connectedIndic = h(
  69                     'div',
  70                     {
  71                         "class": {
  72                             "topindicator": true,
  73                             "indic-left": true,
  74                             "connected": this.oppConnected,
  75                             "disconnected": !this.oppConnected,
  76                         },
  77                         style: {
  78                             "width": indicWidth + "px",
  79                             "height": indicWidth + "px",
  80                         },
  81                     }
  82                 );
  83                 elementArray.push(connectedIndic);
  84             }
  85             let turnIndic = h(
  86                 'div',
  87                 {
  88                     "class": {
  89                         "topindicator": true,
  90                         "indic-right": true,
  91                         "white-turn": this.vr.turn=="w",
  92                         "black-turn": this.vr.turn=="b",
  93                     },
  94                     style: {
  95                         "width": indicWidth + "px",
  96                         "height": indicWidth + "px",
  97                     },
  98                 }
  99             );
 100             elementArray.push(turnIndic);
 101             let expertSwitch = h(
 102                 'button',
 103                 {
 104                     on: { click: this.toggleExpertMode },
 105                     attrs: { "aria-label": 'Toggle expert mode' },
 106                     'class': {
 107                         "tooltip":true,
 108                         "topindicator": true,
 109                         "indic-right": true,
 110                         "expert-switch": true,
 111                         "expert-mode": this.expert,
 112                     },
 113                 },
 114                 [h('i', { 'class': { "material-icons": true } }, "remove_red_eye")]
 115             );
 116             elementArray.push(expertSwitch);
 117             let choices = h('div',
 118                 {
 119                     attrs: { "id": "choices" },
 120                     'class': { 'row': true },
 121                     style: {
 122                         "display": this.choices.length>0?"block":"none",
 123                         "top": "-" + ((sizeY/2)*squareWidth+squareWidth/2) + "px",
 124                         "width": (this.choices.length * squareWidth) + "px",
 125                         "height": squareWidth + "px",
 126                     },
 127                 },
 128                 this.choices.map( m => { //a "choice" is a move
 129                     return h('div',
 130                         {
 131                             'class': {
 132                                 'board': true,
 133                                 ['board'+sizeY]: true,
 134                             },
 135                             style: {
 136                                 'width': (100/this.choices.length) + "%",
 137                                 'padding-bottom': (100/this.choices.length) + "%",
 138                             },
 139                         },
 140                         [h('img',
 141                             {
 142                                 attrs: { "src": '/images/pieces/' +
 143                                     VariantRules.getPpath(m.appear[0].c+m.appear[0].p) + '.svg' },
 144                                 'class': { 'choice-piece': true },
 145                                 on: { "click": e => { this.play(m); this.choices=[]; } },
 146                             })
 147                         ]
 148                     );
 149                 })
 150             );
 151             // Create board element (+ reserves if needed by variant or mode)
 152             let gameDiv = h('div',
 153                 {
 154                     'class': { 'game': true },
 155                 },
 156                 [_.range(sizeX).map(i => {
 157                     let ci = this.mycolor=='w' ? i : sizeX-i-1;
 158                     return h(
 159                         'div',
 160                         {
 161                             'class': {
 162                                 'row': true,
 163                             },
 164                             style: { 'opacity': this.choices.length>0?"0.5":"1" },
 165                         },
 166                         _.range(sizeY).map(j => {
 167                             let cj = this.mycolor=='w' ? j : sizeY-j-1;
 168                             let elems = [];
 169                             if (this.vr.board[ci][cj] != VariantRules.EMPTY)
 170                             {
 171                                 elems.push(
 172                                     h(
 173                                         'img',
 174                                         {
 175                                             'class': {
 176                                                 'piece': true,
 177                                                 'ghost': !!this.selectedPiece
 178                                                     && this.selectedPiece.parentNode.id == "sq-"+ci+"-"+cj,
 179                                             },
 180                                             attrs: {
 181                                                 src: "/images/pieces/" +
 182                                                     VariantRules.getPpath(this.vr.board[ci][cj]) + ".svg",
 183                                             },
 184                                         }
 185                                     )
 186                                 );
 187                             }
 188                             if (!this.expert && hintSquares[ci][cj])
 189                             {
 190                                 elems.push(
 191                                     h(
 192                                         'img',
 193                                         {
 194                                             'class': {
 195                                                 'mark-square': true,
 196                                             },
 197                                             attrs: {
 198                                                 src: "/images/mark.svg",
 199                                             },
 200                                         }
 201                                     )
 202                                 );
 203                             }
 204                             const lm = this.vr.lastMove;
 205                             const highlight = !!lm && _.isMatch(lm.end, {x:ci,y:cj});
 206                             return h(
 207                                 'div',
 208                                 {
 209                                     'class': {
 210                                         'board': true,
 211                                         ['board'+sizeY]: true,
 212                                         'light-square': (i+j)%2==0 && (this.expert || !highlight),
 213                                         'dark-square': (i+j)%2==1 && (this.expert || !highlight),
 214                                         'highlight': !this.expert && highlight,
 215                                         'incheck': !this.expert && incheckSq[ci][cj],
 216                                     },
 217                                     attrs: {
 218                                         id: this.getSquareId({x:ci,y:cj}),
 219                                     },
 220                                 },
 221                                 elems
 222                             );
 223                         })
 224                     );
 225                 }), choices]
 226             );
 227             if (this.mode != "idle")
 228             {
 229                 actionArray.push(
 230                     h('button',
 231                         {
 232                             on: { click: this.resign },
 233                             attrs: { "aria-label": 'Resign' },
 234                             'class': {
 235                                 "tooltip":true,
 236                                 "bottom": true,
 237                             },
 238                         },
 239                         [h('i', { 'class': { "material-icons": true } }, "flag")])
 240                 );
 241             }
 242             elementArray.push(gameDiv);
 243             if (!!this.vr.reserve) //TODO: table, show counts for reserve pieces
 244                 //<tr style="padding:0">
 245                 //    <td style="padding:0;font-size:10px">3</td>
 246             {
 247                 let reservePiecesArray = [];
 248                 for (let i=0; i<VariantRules.RESERVE_PIECES.length; i++)
 249                 {
 250                     reservePiecesArray.push(h('img',
 251                         {
 252                             'class': {"piece":true},
 253                             attrs: {
 254                                 "src": "/images/pieces/" +
 255                                     this.vr.getReservePpath(this.mycolor,i) + ".svg",
 256                                 id: this.getSquareId({x:sizeX,y:i}),
 257                             }
 258                         })
 259                     );
 260                 }
 261                 let reserve = h('div',
 262                     {'class':{'game':true}}, [
 263                         h('div',
 264                             { 'class': { 'row': true }},
 265                             [
 266                                 h('div',
 267                                     {'class':{'board':true, ['board'+sizeY]:true}},
 268                                     reservePiecesArray
 269                                 )
 270                             ]
 271                         )
 272                     ],
 273                 );
 274                 elementArray.push(reserve);
 275             }
 276             const eogMessage = this.getEndgameMessage(this.score);
 277             const modalEog = [
 278                 h('input',
 279                     {
 280                         attrs: { "id": "modal-eog", type: "checkbox" },
 281                         "class": { "modal": true },
 282                     }),
 283                 h('div',
 284                     {
 285                         attrs: { "role": "dialog", "aria-labelledby": "dialog-title" },
 286                     },
 287                     [
 288                         h('div',
 289                             {
 290                                 "class": { "card": true, "smallpad": true },
 291                             },
 292                             [
 293                                 h('label',
 294                                     {
 295                                         attrs: { "for": "modal-eog" },
 296                                         "class": { "modal-close": true },
 297                                     }
 298                                 ),
 299                                 h('h3',
 300                                     {
 301                                         "class": { "section": true },
 302                                         domProps: { innerHTML: eogMessage },
 303                                     }
 304                                 )
 305                             ]
 306                         )
 307                     ]
 308                 )
 309             ];
 310             elementArray = elementArray.concat(modalEog);
 311         }
 312         const modalNewgame = [
 313             h('input',
 314                 {
 315                     attrs: { "id": "modal-newgame", type: "checkbox" },
 316                     "class": { "modal": true },
 317                 }),
 318             h('div',
 319                 {
 320                     attrs: { "role": "dialog", "aria-labelledby": "dialog-title" },
 321                 },
 322                 [
 323                     h('div',
 324                         {
 325                             "class": { "card": true, "smallpad": true },
 326                         },
 327                         [
 328                             h('label',
 329                                 {
 330                                     attrs: { "id": "close-newgame", "for": "modal-newgame" },
 331                                     "class": { "modal-close": true },
 332                                 }
 333                             ),
 334                             h('h3',
 335                                 {
 336                                     "class": { "section": true },
 337                                     domProps: { innerHTML: "New game" },
 338                                 }
 339                             ),
 340                             h('p',
 341                                 {
 342                                     "class": { "section": true },
 343                                     domProps: { innerHTML: "Waiting for opponent..." },
 344                                 }
 345                             )
 346                         ]
 347                     )
 348                 ]
 349             )
 350         ];
 351         elementArray = elementArray.concat(modalNewgame);
 352         const actions = h('div',
 353             {
 354                 attrs: { "id": "actions" },
 355                 'class': { 'text-center': true },
 356             },
 357             actionArray
 358         );
 359         elementArray.push(actions);
 360         if (this.score != "*")
 361         {
 362             elementArray.push(
 363                 h('div',
 364                     { attrs: { id: "pgn-div" } },
 365                     [
 366                         h('a',
 367                             {
 368                                 attrs: {
 369                                     id: "download",
 370                                     href: "#",
 371                                 }
 372                             }
 373                         ),
 374                         h('p',
 375                             {
 376                                 attrs: { id: "pgn-game" },
 377                                 on: { click: this.download },
 378                                 domProps: {
 379                                     innerHTML: this.pgnTxt
 380                                 }
 381                             }
 382                         )
 383                     ]
 384                 )
 385             );
 386         }
 387         return h(
 388             'div',
 389             {
 390                 'class': {
 391                     "col-sm-12":true,
 392                     "col-md-8":true,
 393                     "col-md-offset-2":true,
 394                     "col-lg-6":true,
 395                     "col-lg-offset-3":true,
 396                 },
 397                 // NOTE: click = mousedown + mouseup --> what about smartphone?!
 398                 on: {
 399                     mousedown: this.mousedown,
 400                     mousemove: this.mousemove,
 401                     mouseup: this.mouseup,
 402                     touchdown: this.mousedown,
 403                     touchmove: this.mousemove,
 404                     touchup: this.mouseup,
 405                 },
 406             },
 407             elementArray
 408         );
 409     },
 410     created: function() {
 411         const url = socketUrl;
 412         const continuation = (localStorage.getItem("variant") === variant);
 413         this.myid = continuation
 414             ? localStorage.getItem("myid")
 415             // random enough (TODO: function)
 416             : (Date.now().toString(36) + Math.random().toString(36).substr(2, 7)).toUpperCase();
 417         if (!continuation)
 418         {
 419             // HACK: play a small silent sound to allow "new game" sound later if tab not focused
 420             new Audio("/sounds/silent.mp3").play().then(() => {}).catch(err => {});
 421         }
 422         this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 423         const socketOpenListener = () => {
 424             if (continuation)
 425             {
 426                 const fen = localStorage.getItem("fen");
 427                 const mycolor = localStorage.getItem("mycolor");
 428                 const oppid = localStorage.getItem("oppid");
 429                 const moves = JSON.parse(localStorage.getItem("moves"));
 430                 this.newGame("human", fen, mycolor, oppid, moves, true);
 431                 // Send ping to server (answer pong if opponent is connected)
 432                 this.conn.send(JSON.stringify({code:"ping",oppid:this.oppid}));
 433             }
 434             else if (localStorage.getItem("newgame") === variant)
 435             {
 436                 // New game request has been cancelled on disconnect
 437                 this.seek = true;
 438                 this.newGame("human", undefined, undefined, undefined, undefined, "reconnect");
 439             }
 440         };
 441         const socketMessageListener = msg => {
 442             const data = JSON.parse(msg.data);
 443             switch (data.code)
 444             {
 445                 case "newgame": //opponent found
 446                     this.newGame("human", data.fen, data.color, data.oppid); //oppid: opponent socket ID
 447                     break;
 448                 case "newmove": //..he played!
 449                     this.play(data.move, "animate");
 450                     break;
 451                 case "pong": //received if we sent a ping (game still alive on our side)
 452                     this.oppConnected = true;
 453                     const L = this.vr.moves.length;
 454                     // Send our "last state" informations to opponent
 455                     this.conn.send(JSON.stringify({
 456                         code:"lastate",
 457                         oppid:this.oppid,
 458                         lastMove:L>0?this.vr.moves[L-1]:undefined,
 459                         movesCount:L,
 460                     }));
 461                     break;
 462                 case "lastate": //got opponent infos about last move (we might have resigned)
 463                     if (this.mode!="human" || this.oppid!=data.oppid)
 464                     {
 465                         // OK, we resigned
 466                         this.conn.send(JSON.stringify({
 467                             code:"lastate",
 468                             oppid:this.oppid,
 469                             lastMove:undefined,
 470                             movesCount:-1,
 471                         }));
 472                     }
 473                     else if (data.movesCount < 0)
 474                     {
 475                         // OK, he resigned
 476                         this.endGame(this.mycolor=="w"?"1-0":"0-1");
 477                     }
 478                     else if (data.movesCount < this.vr.moves.length)
 479                     {
 480                         // We must tell last move to opponent
 481                         const L = this.vr.moves.length;
 482                         this.conn.send(JSON.stringify({
 483                             code:"lastate",
 484                             oppid:this.oppid,
 485                             lastMove:this.vr.moves[L-1],
 486                             movesCount:L,
 487                         }));
 488                     }
 489                     else if (data.movesCount > this.vr.moves.length) //just got last move from him
 490                         this.play(data.lastMove, "animate");
 491                     break;
 492                 case "resign": //..you won!
 493                     this.endGame(this.mycolor=="w"?"1-0":"0-1");
 494                     break;
 495                 // TODO: also use (dis)connect info to count online players?
 496                 case "connect":
 497                 case "disconnect":
 498                     if (this.mode == "human" && this.oppid == data.id)
 499                         this.oppConnected = (data.code == "connect");
 500                     break;
 501             }
 502         };
 503         const socketCloseListener = () => {
 504             this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 505             this.conn.addEventListener('open', socketOpenListener);
 506             this.conn.addEventListener('message', socketMessageListener);
 507             this.conn.addEventListener('close', socketCloseListener);
 508         };
 509         this.conn.onopen = socketOpenListener;
 510         this.conn.onmessage = socketMessageListener;
 511         this.conn.onclose = socketCloseListener;
 512     },
 513     methods: {
 514         download: function() {
 515             let content = document.getElementById("pgn-game").innerHTML;
 516             content = content.replace(/<br>/g, "\n");
 517             // Prepare and trigger download link
 518             let downloadAnchor = document.getElementById("download");
 519             downloadAnchor.setAttribute("download", "game.pgn");
 520             downloadAnchor.href = "data:text/plain;charset=utf-8," + encodeURIComponent(content);
 521             downloadAnchor.click();
 522         },
 523         endGame: function(score) {
 524             this.score = score;
 525             let modalBox = document.getElementById("modal-eog");
 526             modalBox.checked = true;
 527             // Variants may have special PGN structure (so next function isn't defined here)
 528             this.pgnTxt = this.vr.getPGN(this.mycolor, this.score, this.fenStart, this.mode);
 529             setTimeout(() => { modalBox.checked = false; }, 2000);
 530             if (this.mode == "human")
 531                 this.clearStorage();
 532             this.mode = "idle";
 533             this.oppid = "";
 534         },
 535         getEndgameMessage: function(score) {
 536             let eogMessage = "Unfinished";
 537             switch (this.score)
 538             {
 539                 case "1-0":
 540                     eogMessage = "White win";
 541                     break;
 542                 case "0-1":
 543                     eogMessage = "Black win";
 544                     break;
 545                 case "1/2":
 546                     eogMessage = "Draw";
 547                     break;
 548             }
 549             return eogMessage;
 550         },
 551         toggleExpertMode: function() {
 552             this.expert = !this.expert;
 553             document.cookie = "expert=" + (this.expert ? "1" : "0");
 554         },
 555         resign: function() {
 556             if (this.mode == "human" && this.oppConnected)
 557             {
 558                 try {
 559                     this.conn.send(JSON.stringify({code: "resign", oppid: this.oppid}));
 560                 } catch (INVALID_STATE_ERR) {
 561                     return; //socket is not ready (and not yet reconnected)
 562                 }
 563             }
 564             this.endGame(this.mycolor=="w"?"0-1":"1-0");
 565         },
 566         setStorage: function() {
 567             localStorage.setItem("myid", this.myid);
 568             localStorage.setItem("variant", variant);
 569             localStorage.setItem("mycolor", this.mycolor);
 570             localStorage.setItem("oppid", this.oppid);
 571             localStorage.setItem("fenStart", this.fenStart);
 572             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 573             localStorage.setItem("fen", this.vr.getFen());
 574         },
 575         updateStorage: function() {
 576             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 577             localStorage.setItem("fen", this.vr.getFen());
 578         },
 579         clearStorage: function() {
 580             delete localStorage["variant"];
 581             delete localStorage["myid"];
 582             delete localStorage["mycolor"];
 583             delete localStorage["oppid"];
 584             delete localStorage["fenStart"];
 585             delete localStorage["fen"];
 586             delete localStorage["moves"];
 587         },
 588         clickGameSeek: function() {
 589             if (this.mode == "human")
 590                 return; //no newgame while playing
 591             if (this.seek)
 592             {
 593                 delete localStorage["newgame"]; //cancel game seek
 594                 this.seek = false;
 595             }
 596             else
 597                 this.newGame("human");
 598         },
 599         clickComputerGame: function() {
 600             if (this.mode == "human")
 601                 return; //no newgame while playing
 602             this.newGame("computer");
 603         },
 604         newGame: function(mode, fenInit, color, oppId, moves, continuation) {
 605             const fen = fenInit || VariantRules.GenRandInitFen();
 606             console.log(fen); //DEBUG
 607             this.score = "*";
 608             if (mode=="human" && !oppId)
 609             {
 610                 const storageVariant = localStorage.getItem("variant");
 611                 if (!!storageVariant && storageVariant !== variant)
 612                 {
 613                     alert("Finish your " + storageVariant + " game first!");
 614                     return;
 615                 }
 616                 // Send game request and wait..
 617                 localStorage["newgame"] = variant;
 618                 this.seek = true;
 619                 this.clearStorage(); //in case of
 620                 try {
 621                     this.conn.send(JSON.stringify({code:"newgame", fen:fen}));
 622                 } catch (INVALID_STATE_ERR) {
 623                     return; //nothing achieved
 624                 }
 625                 if (continuation !== "reconnect") //TODO: bad HACK...
 626                 {
 627                     let modalBox = document.getElementById("modal-newgame");
 628                     modalBox.checked = true;
 629                     setTimeout(() => { modalBox.checked = false; }, 2000);
 630                 }
 631                 return;
 632             }
 633             // random enough (TODO: function)
 634             this.gameId = (Date.now().toString(36) + Math.random().toString(36).substr(2, 7)).toUpperCase();
 635             this.vr = new VariantRules(fen, moves || []);
 636             this.pgnTxt = ""; //redundant with this.score = "*", but cleaner
 637             this.mode = mode;
 638             this.incheck = []; //in case of
 639             this.fenStart = continuation
 640                 ? localStorage.getItem("fenStart")
 641                 : fen.split(" ")[0]; //Only the position matters
 642             if (mode=="human")
 643             {
 644                 // Opponent found!
 645                 if (!continuation)
 646                 {
 647                     // Not playing sound on game continuation:
 648                     new Audio("/sounds/newgame.mp3").play().then(() => {}).catch(err => {});
 649                     document.getElementById("modal-newgame").checked = false;
 650                 }
 651                 this.oppid = oppId;
 652                 this.oppConnected = true;
 653                 this.mycolor = color;
 654                 this.seek = false;
 655                 if (!!moves && moves.length > 0) //imply continuation
 656                 {
 657                     const lastMove = moves[moves.length-1];
 658                     this.vr.undo(lastMove);
 659                     this.incheck = this.vr.getCheckSquares(lastMove);
 660                     this.vr.play(lastMove, "ingame");
 661                 }
 662                 delete localStorage["newgame"];
 663                 this.setStorage(); //in case of interruptions
 664             }
 665             else //against computer
 666             {
 667                 this.mycolor = Math.random() < 0.5 ? 'w' : 'b';
 668                 if (this.mycolor == 'b')
 669                     setTimeout(this.playComputerMove, 500);
 670             }
 671         },
 672         playComputerMove: function() {
 673             const timeStart = Date.now();
 674             const nbMoves = this.vr.moves.length; //using played moves to know if search finished
 675             const gameId = this.gameId; //to know if game was reset before timer end
 676             setTimeout(
 677                 () => {
 678                     if (gameId != this.gameId)
 679                         return; //game stopped
 680                     const L = this.vr.moves.length;
 681                     if (nbMoves == L || !this.vr.moves[L-1].notation) //move search didn't finish
 682                         this.vr.shouldReturn = true;
 683                 }, 5000);
 684             const compMove = this.vr.getComputerMove();
 685             // (first move) HACK: avoid selecting elements before they appear on page:
 686             const delay = Math.max(500-(Date.now()-timeStart), 0);
 687             setTimeout(() => this.play(compMove, "animate"), delay);
 688         },
 689         // Get the identifier of a HTML table cell from its numeric coordinates o.x,o.y.
 690         getSquareId: function(o) {
 691             // NOTE: a separator is required to allow any size of board
 692             return  "sq-" + o.x + "-" + o.y;
 693         },
 694         // Inverse function
 695         getSquareFromId: function(id) {
 696             let idParts = id.split('-');
 697             return [parseInt(idParts[1]), parseInt(idParts[2])];
 698         },
 699         mousedown: function(e) {
 700             e = e || window.event;
 701             e.preventDefault(); //disable native drag & drop
 702             if (!this.selectedPiece && e.target.classList.contains("piece"))
 703             {
 704                 // Next few lines to center the piece on mouse cursor
 705                 let rect = e.target.parentNode.getBoundingClientRect();
 706                 this.start = {
 707                     x: rect.x + rect.width/2,
 708                     y: rect.y + rect.width/2,
 709                     id: e.target.parentNode.id
 710                 };
 711                 this.selectedPiece = e.target.cloneNode();
 712                 this.selectedPiece.style.position = "absolute";
 713                 this.selectedPiece.style.top = 0;
 714                 this.selectedPiece.style.display = "inline-block";
 715                 this.selectedPiece.style.zIndex = 3000;
 716                 let startSquare = this.getSquareFromId(e.target.parentNode.id);
 717                 this.possibleMoves = this.mode!="idle" && this.vr.canIplay(this.mycolor,startSquare)
 718                     ? this.vr.getPossibleMovesFrom(startSquare)
 719                     : [];
 720                 e.target.parentNode.appendChild(this.selectedPiece);
 721             }
 722         },
 723         mousemove: function(e) {
 724             if (!this.selectedPiece)
 725                 return;
 726             e = e || window.event;
 727             // If there is an active element, move it around
 728             if (!!this.selectedPiece)
 729             {
 730                 this.selectedPiece.style.left = (e.clientX-this.start.x) + "px";
 731                 this.selectedPiece.style.top = (e.clientY-this.start.y) + "px";
 732             }
 733         },
 734         mouseup: function(e) {
 735             if (!this.selectedPiece)
 736                 return;
 737             e = e || window.event;
 738             // Read drop target (or parentElement, parentNode... if type == "img")
 739             this.selectedPiece.style.zIndex = -3000; //HACK to find square from final coordinates
 740             let landing = document.elementFromPoint(e.clientX, e.clientY);
 741             this.selectedPiece.style.zIndex = 3000;
 742             while (landing.tagName == "IMG") //classList.contains(piece) fails because of mark/highlight
 743                 landing = landing.parentNode;
 744             if (this.start.id == landing.id) //a click: selectedPiece and possibleMoves already filled
 745                 return;
 746             // OK: process move attempt
 747             let endSquare = this.getSquareFromId(landing.id);
 748             let moves = this.findMatchingMoves(endSquare);
 749             this.possibleMoves = [];
 750             if (moves.length > 1)
 751                 this.choices = moves;
 752             else if (moves.length==1)
 753                 this.play(moves[0]);
 754             // Else: impossible move
 755             this.selectedPiece.parentNode.removeChild(this.selectedPiece);
 756             delete this.selectedPiece;
 757             this.selectedPiece = null;
 758         },
 759         findMatchingMoves: function(endSquare) {
 760             // Run through moves list and return the matching set (if promotions...)
 761             let moves = [];
 762             this.possibleMoves.forEach(function(m) {
 763                 if (endSquare[0] == m.end.x && endSquare[1] == m.end.y)
 764                     moves.push(m);
 765             });
 766             return moves;
 767         },
 768         animateMove: function(move) {
 769             let startSquare = document.getElementById(this.getSquareId(move.start));
 770             let endSquare = document.getElementById(this.getSquareId(move.end));
 771             let rectStart = startSquare.getBoundingClientRect();
 772             let rectEnd = endSquare.getBoundingClientRect();
 773             let translation = {x:rectEnd.x-rectStart.x, y:rectEnd.y-rectStart.y};
 774             let movingPiece =
 775                 document.querySelector("#" + this.getSquareId(move.start) + " > img.piece");
 776             // HACK for animation (with positive translate, image slides "under background"...)
 777             // Possible improvement: just alter squares on the piece's way...
 778             squares = document.getElementsByClassName("board");
 779             for (let i=0; i<squares.length; i++)
 780             {
 781                 let square = squares.item(i);
 782                 if (square.id != this.getSquareId(move.start))
 783                     square.style.zIndex = "-1";
 784             }
 785             movingPiece.style.transform = "translate(" + translation.x + "px," + translation.y + "px)";
 786             movingPiece.style.transitionDuration = "0.2s";
 787             movingPiece.style.zIndex = "3000";
 788             setTimeout( () => {
 789                 for (let i=0; i<squares.length; i++)
 790                     squares.item(i).style.zIndex = "auto";
 791                 movingPiece.style = {}; //required e.g. for 0-0 with KR swap
 792                 this.play(move);
 793             }, 200);
 794         },
 795         play: function(move, programmatic) {
 796             if (!!programmatic) //computer or human opponent
 797             {
 798                 this.animateMove(move);
 799                 return;
 800             }
 801             this.incheck = this.vr.getCheckSquares(move); //is opponent in check?
 802             // Not programmatic, or animation is over
 803             if (this.mode == "human" && this.vr.turn == this.mycolor)
 804                 this.conn.send(JSON.stringify({code:"newmove", move:move, oppid:this.oppid}));
 805             new Audio("/sounds/chessmove1.mp3").play().then(() => {}).catch(err => {});
 806             this.vr.play(move, "ingame");
 807             if (this.mode == "human")
 808                 this.updateStorage(); //after our moves and opponent moves
 809             const eog = this.vr.checkGameOver();
 810             if (eog != "*")
 811                 this.endGame(eog);
 812             else if (this.mode == "computer" && this.vr.turn != this.mycolor)
 813                 setTimeout(this.playComputerMove, 500);
 814         },
 815     },
 816 })