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         };
  21     },
  22     render(h) {
  23         let [sizeX,sizeY] = VariantRules.size;
  24         // Precompute hints squares to facilitate rendering
  25         let hintSquares = doubleArray(sizeX, sizeY, false);
  26         this.possibleMoves.forEach(m => { hintSquares[m.end.x][m.end.y] = true; });
  27         // Also precompute in-check squares
  28         let incheckSq = doubleArray(sizeX, sizeY, false);
  29         this.incheck.forEach(sq => { incheckSq[sq[0]][sq[1]] = true; });
  30         let elementArray = [];
  31         const playingHuman = (this.mode == "human");
  32         const playingComp = (this.mode == "computer");
  33         let actionArray = [
  34             h('button',
  35                 {
  36                     on: { click: this.clickGameSeek },
  37                     attrs: { "aria-label": 'New game VS human' },
  38                     'class': {
  39                         "tooltip": true,
  40                         "bottom": true, //display below
  41                         "seek": this.seek,
  42                         "playing": playingHuman,
  43                     },
  44                 },
  45                 [h('i', { 'class': { "material-icons": true } }, "accessibility")]),
  46             h('button',
  47                 {
  48                     on: { click: this.clickComputerGame },
  49                     attrs: { "aria-label": 'New game VS computer' },
  50                     'class': {
  51                         "tooltip":true,
  52                         "bottom": true,
  53                         "playing": playingComp,
  54                     },
  55                 },
  56                 [h('i', { 'class': { "material-icons": true } }, "computer")])
  57         ];
  58         if (!!this.vr)
  59         {
  60             const square00 = document.getElementById("sq-0-0");
  61             const squareWidth = !!square00
  62                 ? parseFloat(window.getComputedStyle(square00).width.slice(0,-2))
  63                 : 0;
  64             const indicWidth = (squareWidth>0 ? squareWidth/2 : 20);
  65             if (this.mode == "human")
  66             {
  67                 let connectedIndic = h(
  68                     'div',
  69                     {
  70                         "class": {
  71                             "topindicator": true,
  72                             "indic-left": true,
  73                             "connected": this.oppConnected,
  74                             "disconnected": !this.oppConnected,
  75                         },
  76                         style: {
  77                             "width": indicWidth + "px",
  78                             "height": indicWidth + "px",
  79                         },
  80                     }
  81                 );
  82                 elementArray.push(connectedIndic);
  83             }
  84             let turnIndic = h(
  85                 'div',
  86                 {
  87                     "class": {
  88                         "topindicator": true,
  89                         "indic-right": true,
  90                         "white-turn": this.vr.turn=="w",
  91                         "black-turn": this.vr.turn=="b",
  92                     },
  93                     style: {
  94                         "width": indicWidth + "px",
  95                         "height": indicWidth + "px",
  96                     },
  97                 }
  98             );
  99             elementArray.push(turnIndic);
 100             let expertSwitch = h(
 101                 'button',
 102                 {
 103                     on: { click: this.toggleExpertMode },
 104                     attrs: { "aria-label": 'Toggle expert mode' },
 105                     'class': {
 106                         "tooltip":true,
 107                         "topindicator": true,
 108                         "indic-right": true,
 109                         "expert-switch": true,
 110                         "expert-mode": this.expert,
 111                     },
 112                 },
 113                 [h('i', { 'class': { "material-icons": true } }, "remove_red_eye")]
 114             );
 115             elementArray.push(expertSwitch);
 116             let choices = h('div',
 117                 {
 118                     attrs: { "id": "choices" },
 119                     'class': { 'row': true },
 120                     style: {
 121                         "display": this.choices.length>0?"block":"none",
 122                         "top": "-" + ((sizeY/2)*squareWidth+squareWidth/2) + "px",
 123                         "width": (this.choices.length * squareWidth) + "px",
 124                         "height": squareWidth + "px",
 125                     },
 126                 },
 127                 this.choices.map( m => { //a "choice" is a move
 128                     return h('div',
 129                         {
 130                             'class': { 'board': true },
 131                             style: {
 132                                 'width': (100/this.choices.length) + "%",
 133                                 'padding-bottom': (100/this.choices.length) + "%",
 134                             },
 135                         },
 136                         [h('img',
 137                             {
 138                                 attrs: { "src": '/images/pieces/' +
 139                                     VariantRules.getPpath(m.appear[0].c+m.appear[0].p) + '.svg' },
 140                                 'class': { 'choice-piece': true, 'board': true },
 141                                 on: { "click": e => { this.play(m); this.choices=[]; } },
 142                             })
 143                         ]
 144                     );
 145                 })
 146             );
 147             // Create board element (+ reserves if needed by variant or mode)
 148             let gameDiv = h('div',
 149                 {
 150                     'class': { 'game': true },
 151                 },
 152                 [_.range(sizeX).map(i => {
 153                     let ci = this.mycolor=='w' ? i : sizeX-i-1;
 154                     return h(
 155                         'div',
 156                         {
 157                             'class': {
 158                                 'row': true,
 159                             },
 160                             style: { 'opacity': this.choices.length>0?"0.5":"1" },
 161                         },
 162                         _.range(sizeY).map(j => {
 163                             let cj = this.mycolor=='w' ? j : sizeY-j-1;
 164                             let elems = [];
 165                             if (this.vr.board[ci][cj] != VariantRules.EMPTY)
 166                             {
 167                                 elems.push(
 168                                     h(
 169                                         'img',
 170                                         {
 171                                             'class': {
 172                                                 'piece': true,
 173                                                 'ghost': !!this.selectedPiece
 174                                                     && this.selectedPiece.parentNode.id == "sq-"+ci+"-"+cj,
 175                                             },
 176                                             attrs: {
 177                                                 src: "/images/pieces/" +
 178                                                     VariantRules.getPpath(this.vr.board[ci][cj]) + ".svg",
 179                                             },
 180                                         }
 181                                     )
 182                                 );
 183                             }
 184                             if (!this.expert && hintSquares[ci][cj])
 185                             {
 186                                 elems.push(
 187                                     h(
 188                                         'img',
 189                                         {
 190                                             'class': {
 191                                                 'mark-square': true,
 192                                             },
 193                                             attrs: {
 194                                                 src: "/images/mark.svg",
 195                                             },
 196                                         }
 197                                     )
 198                                 );
 199                             }
 200                             const lm = this.vr.lastMove;
 201                             const highlight = !!lm && _.isMatch(lm.end, {x:ci,y:cj});
 202                             return h(
 203                                 'div',
 204                                 {
 205                                     'class': {
 206                                         'board': true,
 207                                         'light-square': (i+j)%2==0 && (this.expert || !highlight),
 208                                         'dark-square': (i+j)%2==1 && (this.expert || !highlight),
 209                                         'highlight': !this.expert && highlight,
 210                                         'incheck': !this.expert && incheckSq[ci][cj],
 211                                     },
 212                                     attrs: {
 213                                         id: this.getSquareId({x:ci,y:cj}),
 214                                     },
 215                                 },
 216                                 elems
 217                             );
 218                         })
 219                     );
 220                 }), choices]
 221             );
 222             if (this.mode != "idle")
 223             {
 224                 actionArray.push(
 225                     h('button',
 226                         {
 227                             on: { click: this.resign },
 228                             attrs: { "aria-label": 'Resign' },
 229                             'class': {
 230                                 "tooltip":true,
 231                                 "bottom": true,
 232                             },
 233                         },
 234                         [h('i', { 'class': { "material-icons": true } }, "flag")])
 235                 );
 236             }
 237             elementArray.push(gameDiv);
 238     //          if (!!vr.reserve)
 239     //          {
 240     //              let reserve = h('div',
 241     //                  {'class':{'game':true}}, [
 242     //                      h('div',
 243     //                          { 'class': { 'row': true }},
 244     //                          [
 245     //                              h('div',
 246     //                                  {'class':{'board':true}},
 247     //                                  [h('img',{'class':{"piece":true},attrs:{"src":"/images/pieces/wb.svg"}})]
 248     //                              )
 249     //                          ]
 250     //                      )
 251     //                  ],
 252     //              );
 253     //              elementArray.push(reserve);
 254     //          }
 255             const eogMessage = this.getEndgameMessage(this.score);
 256             const modalEog = [
 257                 h('input',
 258                     {
 259                         attrs: { "id": "modal-eog", type: "checkbox" },
 260                         "class": { "modal": true },
 261                     }),
 262                 h('div',
 263                     {
 264                         attrs: { "role": "dialog", "aria-labelledby": "dialog-title" },
 265                     },
 266                     [
 267                         h('div',
 268                             {
 269                                 "class": { "card": true, "smallpad": true },
 270                             },
 271                             [
 272                                 h('label',
 273                                     {
 274                                         attrs: { "for": "modal-eog" },
 275                                         "class": { "modal-close": true },
 276                                     }
 277                                 ),
 278                                 h('h3',
 279                                     {
 280                                         "class": { "section": true },
 281                                         domProps: { innerHTML: eogMessage },
 282                                     }
 283                                 )
 284                             ]
 285                         )
 286                     ]
 287                 )
 288             ];
 289             elementArray = elementArray.concat(modalEog);
 290         }
 291         const modalNewgame = [
 292             h('input',
 293                 {
 294                     attrs: { "id": "modal-newgame", type: "checkbox" },
 295                     "class": { "modal": true },
 296                 }),
 297             h('div',
 298                 {
 299                     attrs: { "role": "dialog", "aria-labelledby": "dialog-title" },
 300                 },
 301                 [
 302                     h('div',
 303                         {
 304                             "class": { "card": true, "smallpad": true },
 305                         },
 306                         [
 307                             h('label',
 308                                 {
 309                                     attrs: { "id": "close-newgame", "for": "modal-newgame" },
 310                                     "class": { "modal-close": true },
 311                                 }
 312                             ),
 313                             h('h3',
 314                                 {
 315                                     "class": { "section": true },
 316                                     domProps: { innerHTML: "New game" },
 317                                 }
 318                             ),
 319                             h('p',
 320                                 {
 321                                     "class": { "section": true },
 322                                     domProps: { innerHTML: "Waiting for opponent..." },
 323                                 }
 324                             )
 325                         ]
 326                     )
 327                 ]
 328             )
 329         ];
 330         elementArray = elementArray.concat(modalNewgame);
 331         const actions = h('div',
 332             {
 333                 attrs: { "id": "actions" },
 334                 'class': { 'text-center': true },
 335             },
 336             actionArray
 337         );
 338         elementArray.push(actions);
 339         if (this.score != "*")
 340         {
 341             elementArray.push(
 342                 h('div',
 343                     { attrs: { id: "pgn-div" } },
 344                     [
 345                         h('a',
 346                             {
 347                                 attrs: {
 348                                     id: "download",
 349                                     href: "#",
 350                                 }
 351                             }
 352                         ),
 353                         h('p',
 354                             {
 355                                 attrs: { id: "pgn-game" },
 356                                 on: { click: this.download },
 357                                 domProps: {
 358                                     innerHTML: this.pgnTxt
 359                                 }
 360                             }
 361                         )
 362                     ]
 363                 )
 364             );
 365         }
 366         return h(
 367             'div',
 368             {
 369                 'class': {
 370                     "col-sm-12":true,
 371                     "col-md-8":true,
 372                     "col-md-offset-2":true,
 373                     "col-lg-6":true,
 374                     "col-lg-offset-3":true,
 375                 },
 376                 // NOTE: click = mousedown + mouseup --> what about smartphone?!
 377                 on: {
 378                     mousedown: this.mousedown,
 379                     mousemove: this.mousemove,
 380                     mouseup: this.mouseup,
 381                     touchdown: this.mousedown,
 382                     touchmove: this.mousemove,
 383                     touchup: this.mouseup,
 384                 },
 385             },
 386             elementArray
 387         );
 388     },
 389     created: function() {
 390         const url = socketUrl;
 391         const continuation = (localStorage.getItem("variant") === variant);
 392         this.myid = continuation
 393             ? localStorage.getItem("myid")
 394             // random enough (TODO: function)
 395             : (Date.now().toString(36) + Math.random().toString(36).substr(2, 7)).toUpperCase();
 396         if (!continuation)
 397         {
 398             // HACK: play a small silent sound to allow "new game" sound later if tab not focused
 399             new Audio("/sounds/silent.mp3").play().then(() => {}).catch(err => {});
 400         }
 401         this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 402         const socketOpenListener = () => {
 403             if (continuation)
 404             {
 405                 const fen = localStorage.getItem("fen");
 406                 const mycolor = localStorage.getItem("mycolor");
 407                 const oppid = localStorage.getItem("oppid");
 408                 const moves = JSON.parse(localStorage.getItem("moves"));
 409                 this.newGame("human", fen, mycolor, oppid, moves, true);
 410                 // Send ping to server (answer pong if opponent is connected)
 411                 this.conn.send(JSON.stringify({code:"ping",oppid:this.oppid}));
 412             }
 413             else if (localStorage.getItem("newgame") === variant)
 414             {
 415                 // New game request has been cancelled on disconnect
 416                 this.seek = true;
 417                 this.newGame("human", undefined, undefined, undefined, undefined, "reconnect");
 418             }
 419         };
 420         const socketMessageListener = msg => {
 421             const data = JSON.parse(msg.data);
 422             switch (data.code)
 423             {
 424                 case "newgame": //opponent found
 425                     this.newGame("human", data.fen, data.color, data.oppid); //oppid: opponent socket ID
 426                     break;
 427                 case "newmove": //..he played!
 428                     this.play(data.move, "animate");
 429                     break;
 430                 case "pong": //received if we sent a ping (game still alive on our side)
 431                     this.oppConnected = true;
 432                     const L = this.vr.moves.length;
 433                     // Send our "last state" informations to opponent
 434                     this.conn.send(JSON.stringify({
 435                         code:"lastate",
 436                         oppid:this.oppid,
 437                         lastMove:L>0?this.vr.moves[L-1]:undefined,
 438                         movesCount:L,
 439                     }));
 440                     break;
 441                 case "lastate": //got opponent infos about last move (we might have resigned)
 442                     if (this.mode!="human" || this.oppid!=data.oppid)
 443                     {
 444                         // OK, we resigned
 445                         this.conn.send(JSON.stringify({
 446                             code:"lastate",
 447                             oppid:this.oppid,
 448                             lastMove:undefined,
 449                             movesCount:-1,
 450                         }));
 451                     }
 452                     else if (data.movesCount < 0)
 453                     {
 454                         // OK, he resigned
 455                         this.endGame(this.mycolor=="w"?"1-0":"0-1");
 456                     }
 457                     else if (data.movesCount < this.vr.moves.length)
 458                     {
 459                         // We must tell last move to opponent
 460                         const L = this.vr.moves.length;
 461                         this.conn.send(JSON.stringify({
 462                             code:"lastate",
 463                             oppid:this.oppid,
 464                             lastMove:this.vr.moves[L-1],
 465                             movesCount:L,
 466                         }));
 467                     }
 468                     else if (data.movesCount > this.vr.moves.length) //just got last move from him
 469                         this.play(data.lastMove, "animate");
 470                     break;
 471                 case "resign": //..you won!
 472                     this.endGame(this.mycolor=="w"?"1-0":"0-1");
 473                     break;
 474                 // TODO: also use (dis)connect info to count online players?
 475                 case "connect":
 476                 case "disconnect":
 477                     if (this.mode == "human" && this.oppid == data.id)
 478                         this.oppConnected = (data.code == "connect");
 479                     break;
 480             }
 481         };
 482         const socketCloseListener = () => {
 483             this.conn = new WebSocket(url + "/?sid=" + this.myid + "&page=" + variant);
 484             this.conn.addEventListener('open', socketOpenListener);
 485             this.conn.addEventListener('message', socketMessageListener);
 486             this.conn.addEventListener('close', socketCloseListener);
 487         };
 488         this.conn.onopen = socketOpenListener;
 489         this.conn.onmessage = socketMessageListener;
 490         this.conn.onclose = socketCloseListener;
 491     },
 492     methods: {
 493         download: function() {
 494             let content = document.getElementById("pgn-game").innerHTML;
 495             content = content.replace(/<br>/g, "\n");
 496             // Prepare and trigger download link
 497             let downloadAnchor = document.getElementById("download");
 498             downloadAnchor.setAttribute("download", "game.pgn");
 499             downloadAnchor.href = "data:text/plain;charset=utf-8," + encodeURIComponent(content);
 500             downloadAnchor.click();
 501         },
 502         endGame: function(score) {
 503             this.score = score;
 504             let modalBox = document.getElementById("modal-eog");
 505             modalBox.checked = true;
 506             // Variants may have special PGN structure (so next function isn't defined here)
 507             this.pgnTxt = this.vr.getPGN(this.mycolor, this.score, this.fenStart, this.mode);
 508             setTimeout(() => { modalBox.checked = false; }, 2000);
 509             if (this.mode == "human")
 510                 this.clearStorage();
 511             this.mode = "idle";
 512             this.oppid = "";
 513         },
 514         getEndgameMessage: function(score) {
 515             let eogMessage = "Unfinished";
 516             switch (this.score)
 517             {
 518                 case "1-0":
 519                     eogMessage = "White win";
 520                     break;
 521                 case "0-1":
 522                     eogMessage = "Black win";
 523                     break;
 524                 case "1/2":
 525                     eogMessage = "Draw";
 526                     break;
 527             }
 528             return eogMessage;
 529         },
 530         toggleExpertMode: function() {
 531             this.expert = !this.expert;
 532             document.cookie = "expert=" + (this.expert ? "1" : "0");
 533         },
 534         resign: function() {
 535             if (this.mode == "human" && this.oppConnected)
 536             {
 537                 try {
 538                     this.conn.send(JSON.stringify({code: "resign", oppid: this.oppid}));
 539                 } catch (INVALID_STATE_ERR) {
 540                     return; //socket is not ready (and not yet reconnected)
 541                 }
 542             }
 543             this.endGame(this.mycolor=="w"?"0-1":"1-0");
 544         },
 545         setStorage: function() {
 546             localStorage.setItem("myid", this.myid);
 547             localStorage.setItem("variant", variant);
 548             localStorage.setItem("mycolor", this.mycolor);
 549             localStorage.setItem("oppid", this.oppid);
 550             localStorage.setItem("fenStart", this.fenStart);
 551             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 552             localStorage.setItem("fen", this.vr.getFen());
 553         },
 554         updateStorage: function() {
 555             localStorage.setItem("moves", JSON.stringify(this.vr.moves));
 556             localStorage.setItem("fen", this.vr.getFen());
 557         },
 558         clearStorage: function() {
 559             delete localStorage["variant"];
 560             delete localStorage["myid"];
 561             delete localStorage["mycolor"];
 562             delete localStorage["oppid"];
 563             delete localStorage["fenStart"];
 564             delete localStorage["fen"];
 565             delete localStorage["moves"];
 566         },
 567         clickGameSeek: function() {
 568             if (this.mode == "human")
 569                 return; //no newgame while playing
 570             if (this.seek)
 571             {
 572                 delete localStorage["newgame"]; //cancel game seek
 573                 this.seek = false;
 574             }
 575             else
 576                 this.newGame("human");
 577         },
 578         clickComputerGame: function() {
 579             if (this.mode == "human")
 580                 return; //no newgame while playing
 581             this.newGame("computer");
 582         },
 583         newGame: function(mode, fenInit, color, oppId, moves, continuation) {
 584             //const fen = "1n2T1n0/p2pO2p/1s1k1s2/8/3S2p1/2U2cO1/P3PuPP/3K1BR1 0100";
 585             const fen = fenInit || VariantRules.GenRandInitFen();
 586             console.log(fen); //DEBUG
 587             this.score = "*";
 588             if (mode=="human" && !oppId)
 589             {
 590                 const storageVariant = localStorage.getItem("variant");
 591                 if (!!storageVariant && storageVariant !== variant)
 592                 {
 593                     alert("Finish your " + storageVariant + " game first!");
 594                     return;
 595                 }
 596                 // Send game request and wait..
 597                 localStorage["newgame"] = variant;
 598                 this.seek = true;
 599                 this.clearStorage(); //in case of
 600                 try {
 601                     this.conn.send(JSON.stringify({code:"newgame", fen:fen}));
 602                 } catch (INVALID_STATE_ERR) {
 603                     return; //nothing achieved
 604                 }
 605                 if (continuation !== "reconnect") //TODO: bad HACK...
 606                 {
 607                     let modalBox = document.getElementById("modal-newgame");
 608                     modalBox.checked = true;
 609                     setTimeout(() => { modalBox.checked = false; }, 2000);
 610                 }
 611                 return;
 612             }
 613             this.vr = new VariantRules(fen, moves || []);
 614             this.pgnTxt = ""; //redundant with this.score = "*", but cleaner
 615             this.mode = mode;
 616             this.incheck = []; //in case of
 617             this.fenStart = continuation
 618                 ? localStorage.getItem("fenStart")
 619                 : fen.split(" ")[0]; //Only the position matters
 620             if (mode=="human")
 621             {
 622                 // Opponent found!
 623                 if (!continuation)
 624                 {
 625                     // Not playing sound on game continuation:
 626                     new Audio("/sounds/newgame.mp3").play().then(() => {}).catch(err => {});
 627                     document.getElementById("modal-newgame").checked = false;
 628                 }
 629                 this.oppid = oppId;
 630                 this.oppConnected = true;
 631                 this.mycolor = color;
 632                 this.seek = false;
 633                 if (!!moves && moves.length > 0) //imply continuation
 634                 {
 635                     const lastMove = moves[moves.length-1];
 636                     this.vr.undo(lastMove);
 637                     this.incheck = this.vr.getCheckSquares(lastMove);
 638                     this.vr.play(lastMove, "ingame");
 639                 }
 640                 delete localStorage["newgame"];
 641                 this.setStorage(); //in case of interruptions
 642             }
 643             else //against computer
 644             {
 645                 this.mycolor = Math.random() < 0.5 ? 'w' : 'b';
 646                 if (this.mycolor == 'b')
 647                     setTimeout(this.playComputerMove, 500);
 648             }
 649         },
 650         playComputerMove: function() {
 651             const timeStart = Date.now();
 652             const nbMoves = this.vr.moves.length; //using played moves to know if search finished
 653             setTimeout(
 654                 () => {
 655                     const L = this.vr.moves.length;
 656                     if (nbMoves == L || !this.vr.moves[L-1].notation) //move search didn't finish
 657                         this.vr.shouldReturn = true;
 658                 }, 5000);
 659             const compMove = this.vr.getComputerMove();
 660             // (first move) HACK: avoid selecting elements before they appear on page:
 661             const delay = Math.max(500-(Date.now()-timeStart), 0);
 662             setTimeout(() => this.play(compMove, "animate"), delay);
 663         },
 664         // Get the identifier of a HTML table cell from its numeric coordinates o.x,o.y.
 665         getSquareId: function(o) {
 666             // NOTE: a separator is required to allow any size of board
 667             return  "sq-" + o.x + "-" + o.y;
 668         },
 669         // Inverse function
 670         getSquareFromId: function(id) {
 671             let idParts = id.split('-');
 672             return [parseInt(idParts[1]), parseInt(idParts[2])];
 673         },
 674         mousedown: function(e) {
 675             e = e || window.event;
 676             e.preventDefault(); //disable native drag & drop
 677             if (!this.selectedPiece && e.target.classList.contains("piece"))
 678             {
 679                 // Next few lines to center the piece on mouse cursor
 680                 let rect = e.target.parentNode.getBoundingClientRect();
 681                 this.start = {
 682                     x: rect.x + rect.width/2,
 683                     y: rect.y + rect.width/2,
 684                     id: e.target.parentNode.id
 685                 };
 686                 this.selectedPiece = e.target.cloneNode();
 687                 this.selectedPiece.style.position = "absolute";
 688                 this.selectedPiece.style.top = 0;
 689                 this.selectedPiece.style.display = "inline-block";
 690                 this.selectedPiece.style.zIndex = 3000;
 691                 let startSquare = this.getSquareFromId(e.target.parentNode.id);
 692                 this.possibleMoves = this.mode!="idle" && this.vr.canIplay(this.mycolor,startSquare)
 693                     ? this.vr.getPossibleMovesFrom(startSquare)
 694                     : [];
 695                 e.target.parentNode.appendChild(this.selectedPiece);
 696             }
 697         },
 698         mousemove: function(e) {
 699             if (!this.selectedPiece)
 700                 return;
 701             e = e || window.event;
 702             // If there is an active element, move it around
 703             if (!!this.selectedPiece)
 704             {
 705                 this.selectedPiece.style.left = (e.clientX-this.start.x) + "px";
 706                 this.selectedPiece.style.top = (e.clientY-this.start.y) + "px";
 707             }
 708         },
 709         mouseup: function(e) {
 710             if (!this.selectedPiece)
 711                 return;
 712             e = e || window.event;
 713             // Read drop target (or parentElement, parentNode... if type == "img")
 714             this.selectedPiece.style.zIndex = -3000; //HACK to find square from final coordinates
 715             let landing = document.elementFromPoint(e.clientX, e.clientY);
 716             this.selectedPiece.style.zIndex = 3000;
 717             while (landing.tagName == "IMG") //classList.contains(piece) fails because of mark/highlight
 718                 landing = landing.parentNode;
 719             if (this.start.id == landing.id) //a click: selectedPiece and possibleMoves already filled
 720                 return;
 721             // OK: process move attempt
 722             let endSquare = this.getSquareFromId(landing.id);
 723             let moves = this.findMatchingMoves(endSquare);
 724             this.possibleMoves = [];
 725             if (moves.length > 1)
 726                 this.choices = moves;
 727             else if (moves.length==1)
 728                 this.play(moves[0]);
 729             // Else: impossible move
 730             this.selectedPiece.parentNode.removeChild(this.selectedPiece);
 731             delete this.selectedPiece;
 732             this.selectedPiece = null;
 733         },
 734         findMatchingMoves: function(endSquare) {
 735             // Run through moves list and return the matching set (if promotions...)
 736             let moves = [];
 737             this.possibleMoves.forEach(function(m) {
 738                 if (endSquare[0] == m.end.x && endSquare[1] == m.end.y)
 739                     moves.push(m);
 740             });
 741             return moves;
 742         },
 743         animateMove: function(move) {
 744             let startSquare = document.getElementById(this.getSquareId(move.start));
 745             let endSquare = document.getElementById(this.getSquareId(move.end));
 746             let rectStart = startSquare.getBoundingClientRect();
 747             let rectEnd = endSquare.getBoundingClientRect();
 748             let translation = {x:rectEnd.x-rectStart.x, y:rectEnd.y-rectStart.y};
 749             let movingPiece =
 750                 document.querySelector("#" + this.getSquareId(move.start) + " > img.piece");
 751             // HACK for animation (with positive translate, image slides "under background"...)
 752             // Possible improvement: just alter squares on the piece's way...
 753             squares = document.getElementsByClassName("board");
 754             for (let i=0; i<squares.length; i++)
 755             {
 756                 let square = squares.item(i);
 757                 if (square.id != this.getSquareId(move.start))
 758                     square.style.zIndex = "-1";
 759             }
 760             movingPiece.style.transform = "translate(" + translation.x + "px," + translation.y + "px)";
 761             movingPiece.style.transitionDuration = "0.2s";
 762             movingPiece.style.zIndex = "3000";
 763             setTimeout( () => {
 764                 for (let i=0; i<squares.length; i++)
 765                     squares.item(i).style.zIndex = "auto";
 766                 movingPiece.style = {}; //required e.g. for 0-0 with KR swap
 767                 this.play(move);
 768             }, 200);
 769         },
 770         play: function(move, programmatic) {
 771             if (!!programmatic) //computer or human opponent
 772             {
 773                 this.animateMove(move);
 774                 return;
 775             }
 776             this.incheck = this.vr.getCheckSquares(move); //is opponent in check?
 777             // Not programmatic, or animation is over
 778             if (this.mode == "human" && this.vr.turn == this.mycolor)
 779                 this.conn.send(JSON.stringify({code:"newmove", move:move, oppid:this.oppid}));
 780             new Audio("/sounds/chessmove1.mp3").play().then(() => {}).catch(err => {});
 781             this.vr.play(move, "ingame");
 782             if (this.mode == "human")
 783                 this.updateStorage(); //after our moves and opponent moves
 784             const eog = this.vr.checkGameOver();
 785             if (eog != "*")
 786                 this.endGame(eog);
 787             else if (this.mode == "computer" && this.vr.turn != this.mycolor)
 788                 setTimeout(this.playComputerMove, 500);
 789         },
 790     },
 791 })