4 * Version of this script. If the server returns a version larger than
5 * this, it is a sign we should reload to upgrade ourselves.
10 var SCRIPT_VERSION = 2016113008;
13 * The current backend URL.
18 var backend_url = "/analysis.pl";
19 var backend_hash_url = "/hash";
21 /** @type {window.ChessBoard} @private */
24 /** @type {boolean} @private */
25 var board_is_animating = false;
28 * The most recent analysis data we have from the server
29 * (about the most recent position).
33 var current_analysis_data = null;
36 * If we are displaying previous analysis or from hash, this is non-null,
37 * and will override most of current_analysis_data.
42 var displayed_analysis_data = null;
45 * Games currently in progress, if any.
57 var current_games = null;
72 /** @type {Array.<Array.<boolean>>} */
73 var occupied_by_arrows = [];
75 /** Currently displayed refutation lines (on-screen).
76 * Can either come from the current_analysis_data, displayed_analysis_data,
77 * or hash_refutation_lines.
79 var refutation_lines = [];
81 /** Refutation lines from current hash probe.
83 * If non-null, will override refutation lines from the base position.
84 * Note that these are relative to display_fen, not base_fen.
86 var hash_refutation_lines = null;
88 /** @type {!number} @private */
91 /** @type {!string} @private */
94 /** @type {number} @private */
97 /** @type {boolean} @private */
98 var truncate_display_history = true;
100 /** @type {!string|undefined} @private */
101 var highlight_from = undefined;
103 /** @type {!string|undefined} @private */
104 var highlight_to = undefined;
106 /** The HTML object of the move currently being highlighted (in red).
109 var highlighted_move = null;
111 /** Currently suggested/recommended move when dragging.
112 * @type {?{from: !string, to: !string}}
115 var recommended_move = null;
117 /** If reverse-dragging (dragging from the destination square to the
118 * source square), the destination square.
122 var reverse_dragging_from = null;
124 /** @type {?number} @private */
127 /** @type {boolean} @private */
128 var enable_sound = false;
131 * Our best estimate of how many milliseconds we need to add to
132 * new Date() to get the true UTC time. Calibrated against the
138 var client_clock_offset_ms = null;
140 var clock_timer = null;
142 /** The current position being analyzed, represented as a FEN string.
143 * Note that this is not necessarily the same as display_fen.
149 /** The current position on the board, represented as a FEN string.
150 * Note that board.fen() does not contain e.g. who is to play.
154 var display_fen = null;
158 * pv: Array.<string>,
161 * scores: Array<{first_move: number, score: Object}>,
162 * start_display_move_num: number
165 * "start_display_move_num" is the (half-)move number to start displaying the PV at.
166 * "score" is also evaluated at this point.
169 /** All PVs that we currently know of.
171 * Element 0 is history (or null if no history).
172 * Element 1 is current main PV, or explored line if nowhere else on the screen.
173 * All remaining elements are refutation lines (multi-PV).
175 * @type {Array.<DisplayLine>}
178 var display_lines = [];
180 /** @type {?DisplayLine} @private */
181 var current_display_line = null;
183 /** @type {boolean} @private */
184 var current_display_line_is_history = false;
186 /** @type {?number} @private */
187 var current_display_move = null;
190 * The current backend request to get main analysis (not history), if any,
191 * so that we can abort it.
196 var current_analysis_xhr = null;
199 * The current timer to fire off a request to get main analysis (not history),
200 * if any, so that we can abort it.
205 var current_analysis_request_timer = null;
208 * The current backend request to get historic data, if any.
213 var current_historic_xhr = null;
216 * The current backend request to get hash probes, if any, so that we can abort it.
221 var current_hash_xhr = null;
224 * The current timer to display hash probe information (it could be waiting on the
225 * board to stop animating), if any, so that we can abort it.
230 var current_hash_display_timer = null;
232 var supports_html5_storage = function() {
234 return 'localStorage' in window && window['localStorage'] !== null;
240 // Make the unique token persistent so people refreshing the page won't count twice.
241 // Of course, you can never fully protect against people deliberately wanting to spam.
242 var get_unique = function() {
243 var use_local_storage = supports_html5_storage();
244 if (use_local_storage && localStorage['unique']) {
245 return localStorage['unique'];
247 var unique = Math.random();
248 if (use_local_storage) {
249 localStorage['unique'] = unique;
254 var request_update = function() {
255 current_analysis_request_timer = null;
257 current_analysis_xhr = $.ajax({
258 url: backend_url + "?ims=" + ims + "&unique=" + unique
259 }).done(function(data, textstatus, xhr) {
260 sync_server_clock(xhr.getResponseHeader('Date'));
261 ims = xhr.getResponseHeader('X-RGLM');
262 var num_viewers = xhr.getResponseHeader('X-RGNV');
264 if (Array.isArray(data)) {
265 new_data = JSON.parse(JSON.stringify(current_analysis_data));
266 JSON_delta.patch(new_data, data);
271 var minimum_version = xhr.getResponseHeader('X-RGMV');
272 if (minimum_version && minimum_version > SCRIPT_VERSION) {
273 // Upgrade to latest version with a force-reload.
274 location.reload(true);
277 // Verify that the PV makes sense.
279 if (new_data['pv']) {
280 var hiddenboard = new Chess(new_data['position']['fen']);
281 for (var i = 0; i < new_data['pv'].length; ++i) {
282 if (hiddenboard.move(new_data['pv'][i]) === null) {
291 possibly_play_sound(current_analysis_data, new_data);
292 current_analysis_data = new_data;
294 update_num_viewers(num_viewers);
296 console.log("Received invalid update, waiting five seconds and trying again.");
297 setTimeout(function() { location.reload(true); }, 5000);
301 if (!backend_url.match(/history/)) {
302 current_analysis_request_timer = setTimeout(function() { request_update(); }, timeout);
304 }).fail(function(jqXHR, textStatus, errorThrown) {
305 if (textStatus === "abort") {
306 // Aborted because we are switching backends. Abandon and don't retry,
307 // because another one is already started for us.
309 // Backend error or similar. Wait ten seconds, then try again.
310 current_analysis_request_timer = setTimeout(function() { request_update(); }, 10000);
315 var possibly_play_sound = function(old_data, new_data) {
319 if (old_data === null) {
322 var ding = document.getElementById('ding');
323 if (ding && ding.play) {
324 if (old_data['position'] && old_data['position']['fen'] &&
325 new_data['position'] && new_data['position']['fen'] &&
326 (old_data['position']['fen'] !== new_data['position']['fen'] ||
327 old_data['position']['move_num'] !== new_data['position']['move_num'])) {
334 * @type {!string} server_date_string
336 var sync_server_clock = function(server_date_string) {
337 var server_time_ms = new Date(server_date_string).getTime();
338 var client_time_ms = new Date().getTime();
339 var estimated_offset_ms = server_time_ms - client_time_ms;
341 // In order not to let the noise move us too much back and forth
342 // (the server only has one-second resolution anyway), we only
343 // change an existing skew if we are at least five seconds off.
344 if (client_clock_offset_ms === null ||
345 Math.abs(estimated_offset_ms - client_clock_offset_ms) > 5000) {
346 client_clock_offset_ms = estimated_offset_ms;
350 var clear_arrows = function() {
351 for (var i = 0; i < arrows.length; ++i) {
353 if (arrows[i].svg.parentElement) {
354 arrows[i].svg.parentElement.removeChild(arrows[i].svg);
356 delete arrows[i].svg;
361 occupied_by_arrows = [];
362 for (var y = 0; y < 8; ++y) {
363 occupied_by_arrows.push([false, false, false, false, false, false, false, false]);
367 var redraw_arrows = function() {
368 for (var i = 0; i < arrows.length; ++i) {
369 position_arrow(arrows[i]);
373 /** @param {!number} x
376 var sign = function(x) {
386 /** See if drawing this arrow on the board would cause unduly amount of confusion.
387 * @param {!string} from The square the arrow is from (e.g. e4).
388 * @param {!string} to The square the arrow is to (e.g. e4).
391 var interfering_arrow = function(from, to) {
392 var from_col = from.charCodeAt(0) - "a1".charCodeAt(0);
393 var from_row = from.charCodeAt(1) - "a1".charCodeAt(1);
394 var to_col = to.charCodeAt(0) - "a1".charCodeAt(0);
395 var to_row = to.charCodeAt(1) - "a1".charCodeAt(1);
397 occupied_by_arrows[from_row][from_col] = true;
399 // Knight move: Just check that we haven't been at the destination before.
400 if ((Math.abs(to_col - from_col) == 2 && Math.abs(to_row - from_row) == 1) ||
401 (Math.abs(to_col - from_col) == 1 && Math.abs(to_row - from_row) == 2)) {
402 return occupied_by_arrows[to_row][to_col];
405 // Sliding piece: Check if anything except the from-square is seen before.
406 var dx = sign(to_col - from_col);
407 var dy = sign(to_row - from_row);
413 if (occupied_by_arrows[y][x]) {
416 occupied_by_arrows[y][x] = true;
417 } while (x != to_col || y != to_row);
422 /** Find a point along the coordinate system given by the given line,
423 * <t> units forward from the start of the line, <u> units to the right of it.
424 * @param {!number} x1
425 * @param {!number} x2
426 * @param {!number} y1
427 * @param {!number} y2
430 * @return {!string} The point in "x y" form, suitable for SVG paths.
432 var point_from_start = function(x1, y1, x2, y2, t, u) {
436 var norm = 1.0 / Math.sqrt(dx * dx + dy * dy);
440 var x = x1 + dx * t + dy * u;
441 var y = y1 + dy * t - dx * u;
445 /** Find a point along the coordinate system given by the given line,
446 * <t> units forward from the end of the line, <u> units to the right of it.
447 * @param {!number} x1
448 * @param {!number} x2
449 * @param {!number} y1
450 * @param {!number} y2
453 * @return {!string} The point in "x y" form, suitable for SVG paths.
455 var point_from_end = function(x1, y1, x2, y2, t, u) {
459 var norm = 1.0 / Math.sqrt(dx * dx + dy * dy);
463 var x = x2 + dx * t + dy * u;
464 var y = y2 + dy * t - dx * u;
468 var position_arrow = function(arrow) {
470 if (arrow.svg.parentElement) {
471 arrow.svg.parentElement.removeChild(arrow.svg);
475 if (current_display_line !== null && !current_display_line_is_history) {
479 var zoom_factor = $("#board").width() / 400.0;
480 var line_width = arrow.line_width * zoom_factor;
481 var arrow_size = arrow.arrow_size * zoom_factor;
483 var square_width = $(".square-a8").width();
484 var pos, from_y, to_y, from_x, to_x;
485 if (board.orientation() === 'black') {
486 pos = $(".square-h1").position();
487 from_y = (arrow.from_row + 0.5)*square_width;
488 to_y = (arrow.to_row + 0.5)*square_width;
489 from_x = (7 - arrow.from_col + 0.5)*square_width;
490 to_x = (7 - arrow.to_col + 0.5)*square_width;
492 pos = $(".square-a8").position();
493 from_y = (7 - arrow.from_row + 0.5)*square_width;
494 to_y = (7 - arrow.to_row + 0.5)*square_width;
495 from_x = (arrow.from_col + 0.5)*square_width;
496 to_x = (arrow.to_col + 0.5)*square_width;
499 var SVG_NS = "http://www.w3.org/2000/svg";
500 var XHTML_NS = "http://www.w3.org/1999/xhtml";
501 var svg = document.createElementNS(SVG_NS, "svg");
502 svg.setAttribute("width", /** @type{number} */ ($("#board").width()));
503 svg.setAttribute("height", /** @type{number} */ ($("#board").height()));
504 svg.setAttribute("style", "position: absolute");
505 svg.setAttribute("position", "absolute");
506 svg.setAttribute("version", "1.1");
507 svg.setAttribute("class", "c1");
508 svg.setAttribute("xmlns", XHTML_NS);
516 var outline = document.createElementNS(SVG_NS, "path");
517 outline.setAttribute("d", "M " + point_from_start(x1, y1, x2, y2, arrow_size / 2, 0) + " L " + point_from_end(x1, y1, x2, y2, -arrow_size / 2, 0));
518 outline.setAttribute("xmlns", XHTML_NS);
519 outline.setAttribute("stroke", "#666");
520 outline.setAttribute("stroke-width", line_width + 2);
521 outline.setAttribute("fill", "none");
522 svg.appendChild(outline);
524 var path = document.createElementNS(SVG_NS, "path");
525 path.setAttribute("d", "M " + point_from_start(x1, y1, x2, y2, arrow_size / 2, 0) + " L " + point_from_end(x1, y1, x2, y2, -arrow_size / 2, 0));
526 path.setAttribute("xmlns", XHTML_NS);
527 path.setAttribute("stroke", arrow.fg_color);
528 path.setAttribute("stroke-width", line_width);
529 path.setAttribute("fill", "none");
530 svg.appendChild(path);
532 // Then the arrow head.
533 var head = document.createElementNS(SVG_NS, "path");
534 head.setAttribute("d",
535 "M " + point_from_end(x1, y1, x2, y2, 0, 0) +
536 " L " + point_from_end(x1, y1, x2, y2, -arrow_size, -arrow_size / 2) +
537 " L " + point_from_end(x1, y1, x2, y2, -arrow_size * .623, 0.0) +
538 " L " + point_from_end(x1, y1, x2, y2, -arrow_size, arrow_size / 2) +
539 " L " + point_from_end(x1, y1, x2, y2, 0, 0));
540 head.setAttribute("xmlns", XHTML_NS);
541 head.setAttribute("stroke", "#000");
542 head.setAttribute("stroke-width", "1");
543 head.setAttribute("fill", arrow.fg_color);
544 svg.appendChild(head);
546 $(svg).css({ top: pos.top, left: pos.left, 'pointer-events': 'none' });
547 document.body.appendChild(svg);
552 * @param {!string} from_square
553 * @param {!string} to_square
554 * @param {!string} fg_color
555 * @param {number} line_width
556 * @param {number} arrow_size
558 var create_arrow = function(from_square, to_square, fg_color, line_width, arrow_size) {
559 var from_col = from_square.charCodeAt(0) - "a1".charCodeAt(0);
560 var from_row = from_square.charCodeAt(1) - "a1".charCodeAt(1);
561 var to_col = to_square.charCodeAt(0) - "a1".charCodeAt(0);
562 var to_row = to_square.charCodeAt(1) - "a1".charCodeAt(1);
570 line_width: line_width,
571 arrow_size: arrow_size,
575 position_arrow(arrow);
579 var compare_by_score = function(refutation_lines, invert, a, b) {
580 var sa = compute_score_sort_key(refutation_lines[b]['score'], refutation_lines[b]['depth'], invert);
581 var sb = compute_score_sort_key(refutation_lines[a]['score'], refutation_lines[a]['depth'], invert);
586 * Fake multi-PV using the refutation lines. Find all “relevant” moves,
587 * sorted by quality, descending.
589 * @param {!Object} data
590 * @param {number} margin The maximum number of centipawns worse than the
591 * best move can be and still be included.
592 * @param {boolean} invert Whether black is to play.
593 * @return {Array.<string>} The FEN representation (e.g. Ne4) of all
594 * moves, in score order.
596 var find_nonstupid_moves = function(data, margin, invert) {
597 // First of all, if there are any moves that are more than 0.5 ahead of
598 // the primary move, the refutation lines are probably bunk, so just
600 var best_score = undefined;
601 var pv_score = undefined;
602 for (var move in data['refutation_lines']) {
603 var line = data['refutation_lines'][move];
604 var score = compute_score_sort_key(line['score'], line['depth'], invert, false);
605 if (move == data['pv'][0]) {
608 if (best_score === undefined || score > best_score) {
611 if (line['depth'] < 8) {
616 if (best_score - pv_score > 50) {
620 // Now find all moves that are within “margin” of the best score.
621 // The PV move will always be first.
623 for (var move in data['refutation_lines']) {
624 var line = data['refutation_lines'][move];
625 var score = compute_score_sort_key(line['score'], line['depth'], invert);
626 if (move != data['pv'][0] && best_score - score <= margin) {
630 moves = moves.sort(function(a, b) { return compare_by_score(data['refutation_lines'], data['position']['toplay'] === 'B', a, b) });
631 moves.unshift(data['pv'][0]);
640 var thousands = function(x) {
641 return String(x).split('').reverse().join('').replace(/(\d{3}\B)/g, '$1,').split('').reverse().join('');
645 * @param {!string} start_fen
646 * @param {Array.<string>} pv
647 * @param {number} move_num
648 * @param {!string} toplay
649 * @param {Array<{ first_move: integer, score: Object }>} scores
650 * @param {number} start_display_move_num
651 * @param {number=} opt_limit
652 * @param {boolean=} opt_showlast
654 var add_pv = function(start_fen, pv, move_num, toplay, scores, start_display_move_num, opt_limit, opt_showlast) {
656 start_fen: start_fen,
658 move_num: parseInt(move_num),
661 start_display_move_num: start_display_move_num
663 return print_pv(display_lines.length - 1, opt_limit, opt_showlast);
667 * @param {number} line_num
668 * @param {number=} opt_limit If set, show at most this number of moves.
669 * @param {boolean=} opt_showlast If limit is set, show the last moves instead of the first ones.
671 var print_pv = function(line_num, opt_limit, opt_showlast) {
672 var display_line = display_lines[line_num];
673 var pv = display_line.pv;
674 var move_num = display_line.move_num;
675 var toplay = display_line.toplay;
677 // Truncate PV at the start if needed.
678 var start_display_move_num = display_line.start_display_move_num;
679 if (start_display_move_num > 0) {
680 pv = pv.slice(start_display_move_num);
681 var to_add = start_display_move_num;
682 if (toplay === 'B') {
687 if (to_add % 2 == 1) {
691 move_num += to_add / 2;
696 if (opt_limit && opt_showlast && pv.length > opt_limit) {
697 // Truncate the PV at the beginning (instead of at the end).
698 // We assume here that toplay is 'W'. We also assume that if
699 // opt_showlast is set, then it is the history, and thus,
700 // the UI should be to expand the history.
701 ret = '(<a class="move" href="javascript:collapse_history(false)">…</a>) ';
702 i = pv.length - opt_limit;
707 } else if (toplay == 'B' && pv.length > 0) {
708 var move = "<a class=\"move\" id=\"automove" + line_num + "-0\" href=\"javascript:show_line(" + line_num + ", " + 0 + ");\">" + pv[0] + "</a>";
709 ret = move_num + '. … ' + move;
714 for ( ; i < pv.length; ++i) {
715 var move = "<a class=\"move\" id=\"automove" + line_num + "-" + i + "\" href=\"javascript:show_line(" + line_num + ", " + i + ");\">" + pv[i] + "</a>";
718 if (i > opt_limit && !opt_showlast) {
724 ret += move_num + '. ' + move;
735 /** Update the highlighted to/from squares on the board.
736 * Based on the global "highlight_from" and "highlight_to" variables.
738 var update_board_highlight = function() {
739 $("#board").find('.square-55d63').removeClass('nonuglyhighlight');
740 if ((current_display_line === null || current_display_line_is_history) &&
741 highlight_from !== undefined && highlight_to !== undefined) {
742 $("#board").find('.square-' + highlight_from).addClass('nonuglyhighlight');
743 $("#board").find('.square-' + highlight_to).addClass('nonuglyhighlight');
747 var update_history = function() {
748 if (display_lines[0] === null || display_lines[0].pv.length == 0) {
749 $("#history").html("No history");
750 } else if (truncate_display_history) {
751 $("#history").html(print_pv(0, 8, true));
754 '(<a class="move" href="javascript:collapse_history(true)">collapse</a>) ' +
760 * @param {!boolean} truncate_history
762 var collapse_history = function(truncate_history) {
763 truncate_display_history = truncate_history;
766 window['collapse_history'] = collapse_history;
768 /** Update the HTML display of multi-PV from the global "refutation_lines".
770 * Also recreates the global "display_lines".
772 var update_refutation_lines = function() {
773 if (base_fen === null) {
776 if (display_lines.length > 2) {
777 // Truncate so that only the history and PV is left.
778 display_lines = [ display_lines[0], display_lines[1] ];
780 var tbl = $("#refutationlines");
783 if (display_lines.length < 2) {
787 // Find out where the lines start from.
789 var base_scores = display_lines[1].scores;
790 var start_display_move_num = 0;
791 if (hash_refutation_lines) {
792 base_line = current_display_line.pv.slice(0, current_display_move + 1);
793 base_scores = current_display_line.scores;
794 start_display_move_num = base_line.length;
798 for (var move in refutation_lines) {
802 var invert = (toplay === 'B');
803 if (current_display_line && current_display_move % 2 == 0 && !current_display_line_is_history) {
806 moves = moves.sort(function(a, b) { return compare_by_score(refutation_lines, invert, a, b) });
807 for (var i = 0; i < moves.length; ++i) {
808 var line = refutation_lines[moves[i]];
810 var tr = document.createElement("tr");
812 var move_td = document.createElement("td");
813 tr.appendChild(move_td);
814 $(move_td).addClass("move");
816 var scores = base_scores.concat([{ first_move: start_display_move_num, score: line['score'] }]);
818 if (line['pv'].length == 0) {
819 // Not found, so just make a one-move PV.
820 var move = "<a class=\"move\" href=\"javascript:show_line(" + display_lines.length + ", " + 0 + ");\">" + line['move'] + "</a>";
821 $(move_td).html(move);
822 var score_td = document.createElement("td");
824 $(score_td).addClass("score");
825 $(score_td).text("—");
826 tr.appendChild(score_td);
828 var depth_td = document.createElement("td");
829 tr.appendChild(depth_td);
830 $(depth_td).addClass("depth");
831 $(depth_td).text("—");
833 var pv_td = document.createElement("td");
834 tr.appendChild(pv_td);
835 $(pv_td).addClass("pv");
836 $(pv_td).html(add_pv(base_fen, base_line.concat([ line['move'] ]), move_num, toplay, scores, start_display_move_num));
842 var move = "<a class=\"move\" href=\"javascript:show_line(" + display_lines.length + ", " + 0 + ");\">" + line['move'] + "</a>";
843 $(move_td).html(move);
845 var score_td = document.createElement("td");
846 tr.appendChild(score_td);
847 $(score_td).addClass("score");
848 $(score_td).text(format_short_score(line['score']));
850 var depth_td = document.createElement("td");
851 tr.appendChild(depth_td);
852 $(depth_td).addClass("depth");
853 if (line['depth'] && line['depth'] >= 0) {
854 $(depth_td).text("d" + line['depth']);
856 $(depth_td).text("—");
859 var pv_td = document.createElement("td");
860 tr.appendChild(pv_td);
861 $(pv_td).addClass("pv");
862 $(pv_td).html(add_pv(base_fen, base_line.concat(line['pv']), move_num, toplay, scores, start_display_move_num, 10));
867 // Update the move highlight, as we've rewritten all the HTML.
868 update_move_highlight();
872 * Create a Chess.js board object, containing the given position plus the given moves,
873 * up to the given limit.
875 * @param {?string} fen
876 * @param {Array.<string>} moves
877 * @param {number} last_move
879 var chess_from = function(fen, moves, last_move) {
880 var hiddenboard = new Chess();
881 if (fen !== null && fen !== undefined) {
882 hiddenboard.load(fen);
884 for (var i = 0; i <= last_move; ++i) {
885 if (moves[i] === '0-0') {
886 hiddenboard.move('O-O');
887 } else if (moves[i] === '0-0-0') {
888 hiddenboard.move('O-O-O');
890 hiddenboard.move(moves[i]);
896 var update_game_list = function(games) {
897 $("#games").text("");
898 if (games === null) {
902 var games_div = document.getElementById('games');
903 for (var game_num = 0; game_num < games.length; ++game_num) {
904 var game = games[game_num];
905 var game_span = document.createElement("span");
906 game_span.setAttribute("class", "game");
908 var game_name = document.createTextNode(game['name']);
909 if (game['url'] === backend_url) {
911 game_span.appendChild(game_name);
913 if (current_analysis_data && current_analysis_data['position']) {
915 if (current_analysis_data['position']['result']) {
916 score = " (" + current_analysis_data['position']['result'] + ")";
918 score = " (" + format_short_score(current_analysis_data['score']) + ")";
920 game_span.appendChild(document.createTextNode(score));
924 var game_a = document.createElement("a");
925 game_a.setAttribute("href", "#" + game['id']);
926 game_a.appendChild(game_name);
927 game_span.appendChild(game_a);
930 if (game['result']) {
931 score = " (" + game['result'] + ")";
933 score = " (" + format_short_score(game['score']) + ")";
935 game_span.appendChild(document.createTextNode(score));
938 games_div.appendChild(game_span);
943 * Try to find a running game that matches with the current hash,
944 * and switch to it if we're not already displaying it.
946 var possibly_switch_game_from_hash = function() {
947 var history_match = window.location.hash.match(/^#history=([a-zA-Z0-9_-]+)/);
948 if (history_match !== null) {
949 var game_id = history_match[1];
951 url: '/history/' + game_id + '.json',
953 id: 'history=' + game_id
955 switch_backend(fake_game);
959 if (current_games === null) {
963 var hash = window.location.hash.replace(/^#/,'');
964 for (var i = 0; i < current_games.length; ++i) {
965 if (current_games[i]['id'] === hash) {
966 if (backend_url !== current_games[i]['url']) {
967 switch_backend(current_games[i]);
975 * If this is a Chess960 castling which doesn't move the king,
976 * move the rook instead.
978 var patch_move = function(move) {
979 if (move === null) return null;
980 if (move.from !== move.to) return move;
982 var f = move.rook_sq & 15;
983 var r = move.rook_sq >> 4;
984 var from = ('abcdefgh'.substring(f,f+1) + '87654321'.substring(r,r+1));
987 if (move.to === 'g1') {
989 } else if (move.to === 'g8') {
991 } else if (move.to === 'b1') {
993 } else if (move.to === 'b8') {
997 return { from: from, to: to };
1000 /** Update all the HTML on the page, based on current global state.
1002 var update_board = function() {
1003 var data = displayed_analysis_data || current_analysis_data;
1004 var current_data = current_analysis_data; // Convenience alias.
1008 // Print the history. This is pretty much the only thing that's
1009 // unconditionally taken from current_data (we're not interested in
1010 // historic history).
1011 if (current_data['position']['history']) {
1012 var start = (current_data['position'] && current_data['position']['start_fen']) ? current_data['position']['start_fen'] : 'start';
1013 add_pv(start, current_data['position']['history'], 1, 'W', null, 0, 8, true);
1015 display_lines.push(null);
1019 // Games currently in progress, if any.
1020 if (current_data['games']) {
1021 current_games = current_data['games'];
1022 possibly_switch_game_from_hash();
1024 current_games = null;
1026 update_game_list(current_games);
1028 // The headline. Names are always fetched from current_data;
1029 // the rest can depend a bit.
1032 current_data['position']['player_w'] && current_data['position']['player_b']) {
1033 headline = current_data['position']['player_w'] + '–' +
1034 current_data['position']['player_b'] + ', analysis';
1036 headline = 'Analysis';
1039 // Credits, where applicable. Note that we don't want the footer to change a lot
1040 // when e.g. viewing history, so if any of these changed during the game,
1041 // use the current one still.
1042 if (current_data['using_lomonosov']) {
1043 $("#lomonosov").show();
1045 $("#lomonosov").hide();
1048 // Credits: The engine name/version.
1049 if (current_data['engine'] && current_data['engine']['name'] !== null) {
1050 $("#engineid").text(current_data['engine']['name']);
1053 // Credits: The engine URL.
1054 if (current_data['engine'] && current_data['engine']['url']) {
1055 $("#engineid").attr("href", current_data['engine']['url']);
1057 $("#engineid").removeAttr("href");
1060 // Credits: Engine details.
1061 if (current_data['engine'] && current_data['engine']['details']) {
1062 $("#enginedetails").text(" (" + current_data['engine']['details'] + ")");
1064 $("#enginedetails").text("");
1067 // Credits: Move source, possibly with URL.
1068 if (current_data['move_source'] && current_data['move_source_url']) {
1069 $("#movesource").text("Moves provided by ");
1070 var movesource_a = document.createElement("a");
1071 movesource_a.setAttribute("href", current_data['move_source_url']);
1072 var movesource_text = document.createTextNode(current_data['move_source']);
1073 movesource_a.appendChild(movesource_text);
1074 var movesource_period = document.createTextNode(".");
1075 document.getElementById("movesource").appendChild(movesource_a);
1076 document.getElementById("movesource").appendChild(movesource_period);
1077 } else if (current_data['move_source']) {
1078 $("#movesource").text("Moves provided by " + current_data['move_source'] + ".");
1080 $("#movesource").text("");
1084 if (displayed_analysis_data) {
1085 // Displaying some non-current position, pick out the last move
1086 // from the history. This will work even if the fetch failed.
1087 if (current_display_move !== -1) {
1088 last_move = format_halfmove_with_number(
1089 current_display_line.pv[current_display_move],
1090 current_display_move);
1091 headline += ' after ' + last_move;
1093 } else if (data['position']['last_move'] !== 'none') {
1094 // Find the previous move.
1095 var previous_move_num, previous_toplay;
1096 if (data['position']['toplay'] == 'B') {
1097 previous_move_num = data['position']['move_num'];
1098 previous_toplay = 'W';
1100 previous_move_num = data['position']['move_num'] - 1;
1101 previous_toplay = 'B';
1104 last_move = format_move_with_number(
1105 data['position']['last_move'],
1107 previous_toplay == 'W');
1108 headline += ' after ' + last_move;
1112 $("#headline").text(headline);
1114 // The <title> contains a very brief headline.
1115 var title_elems = [];
1116 if (data['position'] && data['position']['result']) {
1117 title_elems.push(data['position']['result']);
1118 } else if (data['score']) {
1119 title_elems.push(format_short_score(data['score']));
1121 if (last_move !== null) {
1122 title_elems.push(last_move);
1125 if (title_elems.length != 0) {
1126 document.title = '(' + title_elems.join(', ') + ') analysis.sesse.net';
1128 document.title = 'analysis.sesse.net';
1131 // The last move (shown by highlighting the from and to squares).
1132 if (data['position'] && data['position']['last_move_uci']) {
1133 highlight_from = data['position']['last_move_uci'].substr(0, 2);
1134 highlight_to = data['position']['last_move_uci'].substr(2, 2);
1135 } else if (current_display_line_is_history && current_display_line && current_display_move >= 0) {
1136 // We don't have historic analysis for this position, but we
1137 // can reconstruct what the last move was by just replaying
1139 var position = (data['position'] && data['position']['start_fen']) ? data['position']['start_fen'] : null;
1140 var hiddenboard = chess_from(position, current_display_line.pv, current_display_move);
1141 var moves = hiddenboard.history({ verbose: true });
1142 last_move = moves.pop();
1143 highlight_from = last_move.from;
1144 highlight_to = last_move.to;
1146 highlight_from = highlight_to = undefined;
1148 update_board_highlight();
1150 if (data['failed']) {
1151 $("#score").text("No analysis for this move");
1152 $("#pvtitle").text("PV:");
1154 $("#searchstats").html(" ");
1155 $("#refutationlines").empty();
1156 $("#whiteclock").empty();
1157 $("#blackclock").empty();
1158 refutation_lines = [];
1159 update_refutation_lines();
1161 update_displayed_line();
1162 update_move_highlight();
1169 if (current_display_line && !current_display_line_is_history) {
1171 if (current_display_line.scores && current_display_line.scores.length > 0) {
1172 for (var i = 0; i < current_display_line.scores.length; ++i) {
1173 if (current_display_move < current_display_line.scores[i].first_move) {
1176 score = current_display_line.scores[i].score;
1180 $("#score").text(format_long_score(score));
1182 $("#score").text("No score for this line");
1184 } else if (data['score']) {
1185 $("#score").text(format_long_score(data['score']));
1188 // The search stats.
1189 if (data['searchstats']) {
1190 $("#searchstats").html(data['searchstats']);
1191 } else if (data['tablebase'] == 1) {
1192 $("#searchstats").text("Tablebase result");
1193 } else if (data['nodes'] && data['nps'] && data['depth']) {
1194 var stats = thousands(data['nodes']) + ' nodes, ' + thousands(data['nps']) + ' nodes/sec, depth ' + data['depth'] + ' ply';
1195 if (data['seldepth']) {
1196 stats += ' (' + data['seldepth'] + ' selective)';
1198 if (data['tbhits'] && data['tbhits'] > 0) {
1199 if (data['tbhits'] == 1) {
1200 stats += ', one Syzygy hit';
1202 stats += ', ' + thousands(data['tbhits']) + ' Syzygy hits';
1206 $("#searchstats").text(stats);
1208 $("#searchstats").text("");
1211 // Update the board itself.
1212 base_fen = data['position']['fen'];
1213 update_displayed_line();
1216 $("#pvtitle").text("PV:");
1218 var scores = [{ first_move: -1, score: data['score'] }];
1219 $("#pv").html(add_pv(data['position']['fen'], data['pv'], data['position']['move_num'], data['position']['toplay'], scores, 0));
1221 // Update the PV arrow.
1223 if (data['pv'].length >= 1) {
1224 var hiddenboard = new Chess(base_fen);
1226 // draw a continuation arrow as long as it's the same piece
1228 for (var i = 0; i < data['pv'].length; i += 2) {
1229 var move = patch_move(hiddenboard.move(data['pv'][i]));
1231 if ((i >= 2 && move.from != last_to) ||
1232 interfering_arrow(move.from, move.to)) {
1235 create_arrow(move.from, move.to, '#f66', 6, 20);
1237 hiddenboard.move(data['pv'][i + 1]); // To keep continuity.
1240 var alt_moves = find_nonstupid_moves(data, 30, data['position']['toplay'] === 'B');
1241 for (var i = 1; i < alt_moves.length && i < 3; ++i) {
1242 hiddenboard = new Chess(base_fen);
1243 var move = patch_move(hiddenboard.move(alt_moves[i]));
1244 if (move !== null) {
1245 create_arrow(move.from, move.to, '#f66', 1, 10);
1250 // See if all semi-reasonable moves have only one possible response.
1251 if (data['pv'].length >= 2) {
1252 var nonstupid_moves = find_nonstupid_moves(data, 300, data['position']['toplay'] === 'B');
1255 var hiddenboard = new Chess(base_fen);
1256 hiddenboard.move(data['pv'][0]);
1257 response = hiddenboard.move(data['pv'][1]);
1259 for (var i = 0; i < nonstupid_moves.length; ++i) {
1260 if (nonstupid_moves[i] == data['pv'][0]) {
1261 // ignore the PV move for refutation lines.
1264 if (!data['refutation_lines'] ||
1265 !data['refutation_lines'][nonstupid_moves[i]] ||
1266 !data['refutation_lines'][nonstupid_moves[i]]['pv'] ||
1267 data['refutation_lines'][nonstupid_moves[i]]['pv'].length < 2) {
1268 // Incomplete PV, abort.
1269 response = undefined;
1272 var line = data['refutation_lines'][nonstupid_moves[i]];
1273 hiddenboard = new Chess(base_fen);
1274 hiddenboard.move(line['pv'][0]);
1275 var this_response = hiddenboard.move(line['pv'][1]);
1276 if (response.from !== this_response.from || response.to !== this_response.to) {
1277 // Different response depending on lines, abort.
1278 response = undefined;
1283 if (nonstupid_moves.length > 0 && response !== undefined) {
1284 create_arrow(response.from, response.to, '#66f', 6, 20);
1288 // Update the refutation lines.
1289 base_fen = data['position']['fen'];
1290 move_num = parseInt(data['position']['move_num']);
1291 toplay = data['position']['toplay'];
1292 refutation_lines = hash_refutation_lines || data['refutation_lines'];
1293 update_refutation_lines();
1295 // Update the sparkline last, since its size depends on how everything else reflowed.
1296 update_sparkline(data);
1299 var update_sparkline = function(data) {
1300 if (data && data['score_history']) {
1301 var first_move_num = undefined;
1302 for (var halfmove_num in data['score_history']) {
1303 halfmove_num = parseInt(halfmove_num);
1304 if (first_move_num === undefined || halfmove_num < first_move_num) {
1305 first_move_num = halfmove_num;
1308 if (first_move_num !== undefined) {
1309 var last_move_num = data['position']['move_num'] * 2 - 3;
1310 if (data['position']['toplay'] === 'B') {
1314 // Possibly truncate some moves if we don't have enough width.
1315 // FIXME: Sometimes width() for #scorecontainer (and by extent,
1316 // #scoresparkcontainer) on Chrome for mobile seems to start off
1317 // at something very small, and then suddenly snap back into place.
1319 var max_moves = Math.floor($("#scoresparkcontainer").width() / 5) - 5;
1320 if (last_move_num - first_move_num > max_moves) {
1321 first_move_num = last_move_num - max_moves;
1324 var min_score = -100;
1325 var max_score = 100;
1326 var last_score = null;
1328 for (var halfmove_num = first_move_num; halfmove_num <= last_move_num; ++halfmove_num) {
1329 if (data['score_history'][halfmove_num]) {
1330 var score = compute_plot_score(data['score_history'][halfmove_num]);
1332 if (score < min_score) min_score = score;
1333 if (score > max_score) max_score = score;
1335 scores.push(last_score);
1337 if (data['score']) {
1338 scores.push(compute_plot_score(data['score']));
1340 // FIXME: at some widths, calling sparkline() seems to push
1341 // #scorecontainer under the board.
1342 $("#scorespark").sparkline(scores, {
1345 chartRangeMin: min_score,
1346 chartRangeMax: max_score,
1347 tooltipFormatter: function(sparkline, options, fields) {
1348 // score_history contains the Nth _position_, but format_tooltip
1349 // wants to format the Nth _move_; thus the -1.
1350 return format_tooltip(data, fields[0].offset + first_move_num - 1);
1353 $('#scorespark').bind('sparklineClick', function(event) {
1354 var sparkline = event.sparklines[0];
1355 var region = sparkline.getCurrentRegionFields();
1356 if (region[0].offset !== undefined) {
1357 show_line(0, first_move_num + region[0].offset - 1);
1361 $("#scorespark").text("");
1364 $("#scorespark").text("");
1369 * @param {number} num_viewers
1371 var update_num_viewers = function(num_viewers) {
1372 if (num_viewers === null) {
1373 $("#numviewers").text("");
1374 } else if (num_viewers == 1) {
1375 $("#numviewers").text("You are the only current viewer");
1377 $("#numviewers").text(num_viewers + " current viewers");
1381 var update_clock = function() {
1382 clearTimeout(clock_timer);
1384 var data = displayed_analysis_data || current_analysis_data;
1387 if (data['position']) {
1388 var result = data['position']['result'];
1389 if (result === '1-0') {
1390 $("#whiteclock").text("1");
1391 $("#blackclock").text("0");
1392 $("#whiteclock").removeClass("running-clock");
1393 $("#blackclock").removeClass("running-clock");
1396 if (result === '1/2-1/2') {
1397 $("#whiteclock").text("1/2");
1398 $("#blackclock").text("1/2");
1399 $("#whiteclock").removeClass("running-clock");
1400 $("#blackclock").removeClass("running-clock");
1403 if (result === '0-1') {
1404 $("#whiteclock").text("0");
1405 $("#blackclock").text("1");
1406 $("#whiteclock").removeClass("running-clock");
1407 $("#blackclock").removeClass("running-clock");
1412 var white_clock_ms = null;
1413 var black_clock_ms = null;
1416 if (data['position'] &&
1417 data['position']['white_clock'] &&
1418 data['position']['black_clock']) {
1419 white_clock_ms = data['position']['white_clock'] * 1000;
1420 black_clock_ms = data['position']['black_clock'] * 1000;
1423 // Dynamic clock (only one, obviously).
1425 if (data['position']['white_clock_target']) {
1427 $("#whiteclock").addClass("running-clock");
1428 $("#blackclock").removeClass("running-clock");
1429 } else if (data['position']['black_clock_target']) {
1431 $("#whiteclock").removeClass("running-clock");
1432 $("#blackclock").addClass("running-clock");
1434 $("#whiteclock").removeClass("running-clock");
1435 $("#blackclock").removeClass("running-clock");
1439 var now = new Date().getTime() + client_clock_offset_ms;
1440 remaining_ms = data['position'][color + '_clock_target'] * 1000 - now;
1441 if (color === "white") {
1442 white_clock_ms = remaining_ms;
1444 black_clock_ms = remaining_ms;
1448 if (white_clock_ms === null || black_clock_ms === null) {
1449 $("#whiteclock").empty();
1450 $("#blackclock").empty();
1454 // If either player has twenty minutes or less left, add the second counters.
1455 // This matches what DGT clocks do.
1456 var show_seconds = (white_clock_ms < 60 * 20 * 1000 || black_clock_ms < 60 * 20 * 1000);
1459 // See when the clock will change next, and update right after that.
1462 next_update_ms = remaining_ms % 1000 + 100;
1464 next_update_ms = remaining_ms % 60000 + 100;
1466 clock_timer = setTimeout(update_clock, next_update_ms);
1469 $("#whiteclock").text(format_clock(white_clock_ms, show_seconds));
1470 $("#blackclock").text(format_clock(black_clock_ms, show_seconds));
1474 * @param {Number} remaining_ms
1475 * @param {boolean} show_seconds
1477 var format_clock = function(remaining_ms, show_seconds) {
1478 if (remaining_ms <= 0) {
1486 var remaining = Math.floor(remaining_ms / 1000);
1487 var seconds = remaining % 60;
1488 remaining = (remaining - seconds) / 60;
1489 var minutes = remaining % 60;
1490 remaining = (remaining - minutes) / 60;
1491 var hours = remaining;
1493 return format_2d(hours) + ":" + format_2d(minutes) + ":" + format_2d(seconds);
1495 return format_2d(hours) + ":" + format_2d(minutes);
1502 var format_2d = function(x) {
1511 * @param {string} move
1512 * @param {Number} move_num Move number of this move.
1513 * @param {boolean} white_to_play Whether white is to play this move.
1515 var format_move_with_number = function(move, move_num, white_to_play) {
1517 if (white_to_play) {
1518 ret = move_num + '. ';
1520 ret = move_num + '… ';
1527 * @param {string} move
1528 * @param {Number} halfmove_num Half-move number that is to be played,
1531 var format_halfmove_with_number = function(move, halfmove_num) {
1532 return format_move_with_number(
1534 Math.floor(halfmove_num / 2) + 1,
1535 halfmove_num % 2 == 0);
1539 * @param {Object} data
1540 * @param {Number} halfmove_num
1542 var format_tooltip = function(data, halfmove_num) {
1543 if (data['score_history'][halfmove_num + 1] ||
1544 (halfmove_num + 1) === data['position']['history'].length) {
1545 // Position is in the history, or it is the current position
1546 // (which is implicitly tacked onto the history).
1549 if ((halfmove_num + 1) === data['position']['history'].length) {
1550 move = data['position']['last_move'];
1551 short_score = format_short_score(data['score']);
1553 move = data['position']['history'][halfmove_num];
1554 short_score = format_short_score(data['score_history'][halfmove_num + 1]);
1556 if (halfmove_num === -1) {
1557 return "Start position: " + short_score;
1559 var move_with_number = format_halfmove_with_number(move, halfmove_num);
1560 return "After " + move_with_number + ": " + short_score;
1563 for (var i = halfmove_num; i --> -1; ) {
1564 if (data['score_history'][i]) {
1565 var move = data['position']['history'][i];
1567 return "[Analysis kept from start position]";
1569 return "[Analysis kept from " + format_halfmove_with_number(move, i) + "]";
1577 * @param {boolean} truncate_history
1579 var set_truncate_history = function(truncate_history) {
1580 truncate_display_history = truncate_history;
1581 update_refutation_lines();
1583 window['set_truncate_history'] = set_truncate_history;
1586 * @param {number} line_num
1587 * @param {number} move_num
1589 var show_line = function(line_num, move_num) {
1590 if (line_num == -1) {
1591 current_display_line = null;
1592 current_display_move = null;
1593 hash_refutation_lines = null;
1594 if (displayed_analysis_data) {
1595 // TODO: Support exiting to history position if we are in an
1596 // analysis line of a history position.
1597 displayed_analysis_data = null;
1602 current_display_line = jQuery.extend({}, display_lines[line_num]); // Shallow clone.
1603 current_display_move = move_num + current_display_line.start_display_move_num;
1605 current_display_line_is_history = (line_num == 0);
1607 update_historic_analysis();
1608 update_displayed_line();
1609 update_board_highlight();
1610 update_move_highlight();
1613 window['show_line'] = show_line;
1615 var prev_move = function() {
1616 if (current_display_line &&
1617 current_display_move >= current_display_line.start_display_move_num) {
1618 --current_display_move;
1620 update_historic_analysis();
1621 update_displayed_line();
1622 update_move_highlight();
1624 window['prev_move'] = prev_move;
1626 var next_move = function() {
1627 if (current_display_line &&
1628 current_display_move < current_display_line.pv.length - 1) {
1629 ++current_display_move;
1631 update_historic_analysis();
1632 update_displayed_line();
1633 update_move_highlight();
1635 window['next_move'] = next_move;
1637 var next_game = function() {
1638 if (current_games === null) {
1642 // Try to find the game we are currently looking at.
1643 for (var game_num = 0; game_num < current_games.length; ++game_num) {
1644 var game = current_games[game_num];
1645 if (game['url'] === backend_url) {
1646 var next_game_num = (game_num + 1) % current_games.length;
1647 switch_backend(current_games[next_game_num]);
1652 // Couldn't find it; give up.
1655 var update_historic_analysis = function() {
1656 if (!current_display_line_is_history) {
1659 if (current_display_move == current_display_line.pv.length - 1) {
1660 displayed_analysis_data = null;
1664 // Fetch old analysis for this line if it exists.
1665 var hiddenboard = chess_from(current_display_line.start_fen, current_display_line.pv, current_display_move);
1666 var filename = "/history/move" + (current_display_move + 1) + "-" +
1667 hiddenboard.fen().replace(/ /g, '_').replace(/\//g, '-') + ".json";
1669 current_historic_xhr = $.ajax({
1671 }).done(function(data, textstatus, xhr) {
1672 displayed_analysis_data = data;
1674 }).fail(function(jqXHR, textStatus, errorThrown) {
1675 if (textStatus === "abort") {
1676 // Aborted because we are switching backends. Don't do anything;
1677 // we will already have been cleared.
1679 displayed_analysis_data = {'failed': true};
1686 * @param {string} fen
1688 var update_imbalance = function(fen) {
1689 var hiddenboard = new Chess(fen);
1690 var imbalance = {'k': 0, 'q': 0, 'r': 0, 'b': 0, 'n': 0, 'p': 0};
1691 for (var row = 0; row < 8; ++row) {
1692 for (var col = 0; col < 8; ++col) {
1693 var col_text = String.fromCharCode('a1'.charCodeAt(0) + col);
1694 var row_text = String.fromCharCode('a1'.charCodeAt(1) + row);
1695 var square = col_text + row_text;
1696 var contents = hiddenboard.get(square);
1697 if (contents !== null) {
1698 if (contents.color === 'w') {
1699 ++imbalance[contents.type];
1701 --imbalance[contents.type];
1706 var white_imbalance = '';
1707 var black_imbalance = '';
1708 for (var piece in imbalance) {
1709 for (var i = 0; i < imbalance[piece]; ++i) {
1710 white_imbalance += '<img src="img/chesspieces/wikipedia/w' + piece.toUpperCase() + '.png" alt="" style="width: 15px;height: 15px;">';
1712 for (var i = 0; i < -imbalance[piece]; ++i) {
1713 black_imbalance += '<img src="img/chesspieces/wikipedia/b' + piece.toUpperCase() + '.png" alt="" style="width: 15px;height: 15px;">';
1716 $('#whiteimbalance').html(white_imbalance);
1717 $('#blackimbalance').html(black_imbalance);
1720 /** Mark the currently selected move in red.
1721 * Also replaces the PV with the current displayed line if it's not shown
1722 * anywhere else on the screen.
1724 var update_move_highlight = function() {
1725 if (highlighted_move !== null) {
1726 highlighted_move.removeClass('highlight');
1728 if (current_display_line) {
1729 var display_line_num = find_display_line_matching_num();
1730 if (display_line_num === null) {
1731 // Replace the PV with the (complete) line.
1732 $("#pvtitle").text("Exploring:");
1733 current_display_line.start_display_move_num = 0;
1734 display_lines.push(current_display_line);
1735 $("#pv").html(print_pv(display_lines.length - 1));
1736 display_line_num = display_lines.length - 1;
1738 // Clear out the PV, so it's not selected by anything later.
1739 display_lines[1].pv = [];
1742 highlighted_move = $("#automove" + display_line_num + "-" + (current_display_move - current_display_line.start_display_move_num));
1743 highlighted_move.addClass('highlight');
1748 * See if the current displayed line is identical to any of the ones
1749 * we have on screen. (It might not be if e.g. the analysis reloaded
1750 * since we started looking.)
1754 var find_display_line_matching_num = function() {
1755 for (var i = 0; i < display_lines.length; ++i) {
1756 var line = display_lines[i];
1757 if (line.start_display_move_num > 0) continue;
1758 if (current_display_line.start_fen !== line.start_fen) continue;
1759 if (current_display_line.pv.length !== line.pv.length) continue;
1761 for (var j = 0; j < line.pv.length; ++j) {
1762 if (current_display_line.pv[j] !== line.pv[j]) {
1774 /** Update the board based on the currently displayed line.
1776 * TODO: This should really be called only whenever something changes,
1777 * instead of all the time.
1779 var update_displayed_line = function() {
1780 if (current_display_line === null) {
1781 $("#linenav").hide();
1782 $("#linemsg").show();
1783 display_fen = base_fen;
1784 set_board_position(base_fen);
1785 update_imbalance(base_fen);
1789 $("#linenav").show();
1790 $("#linemsg").hide();
1792 if (current_display_move <= 0) {
1793 $("#prevmove").html("Previous");
1795 $("#prevmove").html("<a href=\"javascript:prev_move();\">Previous</a></span>");
1797 if (current_display_move == current_display_line.pv.length - 1) {
1798 $("#nextmove").html("Next");
1800 $("#nextmove").html("<a href=\"javascript:next_move();\">Next</a></span>");
1803 var hiddenboard = chess_from(current_display_line.start_fen, current_display_line.pv, current_display_move);
1804 set_board_position(hiddenboard.fen());
1805 if (display_fen !== hiddenboard.fen() && !current_display_line_is_history) {
1806 // Fire off a hash request, since we're now off the main position
1807 // and it just changed.
1808 explore_hash(hiddenboard.fen());
1810 display_fen = hiddenboard.fen();
1811 update_imbalance(hiddenboard.fen());
1814 var set_board_position = function(new_fen) {
1815 board_is_animating = true;
1816 var old_fen = board.fen();
1817 board.position(new_fen);
1818 if (board.fen() === old_fen) {
1819 board_is_animating = false;
1824 * @param {boolean} param_enable_sound
1826 var set_sound = function(param_enable_sound) {
1827 enable_sound = param_enable_sound;
1829 $("#soundon").html("<strong>On</strong>");
1830 $("#soundoff").html("<a href=\"javascript:set_sound(false)\">Off</a>");
1832 // Seemingly at least Firefox prefers MP3 over Opus; tell it otherwise,
1833 // and also preload the file since the user has selected audio.
1834 var ding = document.getElementById('ding');
1835 if (ding && ding.canPlayType && ding.canPlayType('audio/ogg; codecs="opus"') === 'probably') {
1836 ding.src = 'ding.opus';
1840 $("#soundon").html("<a href=\"javascript:set_sound(true)\">On</a>");
1841 $("#soundoff").html("<strong>Off</strong>");
1843 if (supports_html5_storage()) {
1844 localStorage['enable_sound'] = enable_sound ? 1 : 0;
1847 window['set_sound'] = set_sound;
1849 /** Send off a hash probe request to the backend.
1850 * @param {string} fen
1852 var explore_hash = function(fen) {
1853 // If we already have a backend response going, abort it.
1854 if (current_hash_xhr) {
1855 current_hash_xhr.abort();
1857 if (current_hash_display_timer) {
1858 clearTimeout(current_hash_display_timer);
1859 current_hash_display_timer = null;
1861 $("#refutationlines").empty();
1862 current_hash_xhr = $.ajax({
1863 url: backend_hash_url + "?fen=" + fen
1864 }).done(function(data, textstatus, xhr) {
1865 show_explore_hash_results(data, fen);
1869 /** Process the JSON response from a hash probe request.
1870 * @param {!Object} data
1871 * @param {string} fen
1873 var show_explore_hash_results = function(data, fen) {
1874 if (board_is_animating) {
1875 // Updating while the animation is still going causes
1876 // the animation to jerk. This is pretty crude, but it will do.
1877 current_hash_display_timer = setTimeout(function() { show_explore_hash_results(data, fen); }, 100);
1880 current_hash_display_timer = null;
1881 hash_refutation_lines = data['lines'];
1885 // almost all of this stuff comes from the chessboard.js example page
1886 var onDragStart = function(source, piece, position, orientation) {
1887 var pseudogame = new Chess(display_fen);
1888 if (pseudogame.game_over() === true ||
1889 (pseudogame.turn() === 'w' && piece.search(/^b/) !== -1) ||
1890 (pseudogame.turn() === 'b' && piece.search(/^w/) !== -1)) {
1894 recommended_move = get_best_move(pseudogame, source, null, pseudogame.turn() === 'b');
1895 if (recommended_move) {
1896 var squareEl = $('#board .square-' + recommended_move.to);
1897 squareEl.addClass('highlight1-32417');
1902 var mousedownSquare = function(e) {
1903 reverse_dragging_from = null;
1904 var square = $(this).attr('data-square');
1906 var pseudogame = new Chess(display_fen);
1907 if (pseudogame.game_over() === true) {
1911 // If the square is empty, or has a piece of the side not to move,
1912 // we handle it. If not, normal piece dragging will take it.
1913 var position = board.position();
1914 if (!position.hasOwnProperty(square) ||
1915 (pseudogame.turn() === 'w' && position[square].search(/^b/) !== -1) ||
1916 (pseudogame.turn() === 'b' && position[square].search(/^w/) !== -1)) {
1917 reverse_dragging_from = square;
1918 recommended_move = get_best_move(pseudogame, null, square, pseudogame.turn() === 'b');
1919 if (recommended_move) {
1920 var squareEl = $('#board .square-' + recommended_move.from);
1921 squareEl.addClass('highlight1-32417');
1922 squareEl = $('#board .square-' + recommended_move.to);
1923 squareEl.addClass('highlight1-32417');
1928 var mouseupSquare = function(e) {
1929 if (reverse_dragging_from === null) {
1932 var source = $(this).attr('data-square');
1933 var target = reverse_dragging_from;
1934 reverse_dragging_from = null;
1935 if (onDrop(source, target) !== 'snapback') {
1936 onSnapEnd(source, target);
1938 $("#board").find('.square-55d63').removeClass('highlight1-32417');
1941 var get_best_move = function(game, source, target, invert) {
1942 var moves = game.moves({ verbose: true });
1943 if (source !== null) {
1944 moves = moves.filter(function(move) { return move.from == source; });
1946 if (target !== null) {
1947 moves = moves.filter(function(move) { return move.to == target; });
1949 if (moves.length == 0) {
1952 if (moves.length == 1) {
1956 // More than one move. Use the display lines (if we have them)
1957 // to disambiguate; otherwise, we have no information.
1959 for (var i = 0; i < moves.length; ++i) {
1960 move_hash[moves[i].san] = moves[i];
1963 // See if we're already exploring some line.
1964 if (current_display_line &&
1965 current_display_move < current_display_line.pv.length - 1) {
1966 var first_move = current_display_line.pv[current_display_move + 1];
1967 if (move_hash[first_move]) {
1968 return move_hash[first_move];
1972 // History and PV take priority over the display lines.
1973 for (var i = 0; i < 2; ++i) {
1974 var line = display_lines[i];
1975 var first_move = line.pv[line.start_display_move_num];
1976 if (move_hash[first_move]) {
1977 return move_hash[first_move];
1981 var best_move = null;
1982 var best_move_score = null;
1984 for (var move in refutation_lines) {
1985 var line = refutation_lines[move];
1986 if (!line['score']) {
1989 var first_move = line['pv'][0];
1990 if (move_hash[first_move]) {
1991 var score = compute_score_sort_key(line['score'], line['depth'], invert);
1992 if (best_move_score === null || score > best_move_score) {
1993 best_move = move_hash[first_move];
1994 best_move_score = score;
2001 var onDrop = function(source, target) {
2002 if (source === target) {
2003 if (recommended_move === null) {
2006 // Accept the move. It will be changed in onSnapEnd.
2010 // Suggestion not asked for.
2011 recommended_move = null;
2014 // see if the move is legal
2015 var pseudogame = new Chess(display_fen);
2016 var move = pseudogame.move({
2019 promotion: 'q' // NOTE: always promote to a queen for example simplicity
2023 if (move === null) return 'snapback';
2026 var onSnapEnd = function(source, target) {
2027 if (source === target && recommended_move !== null) {
2028 source = recommended_move.from;
2029 target = recommended_move.to;
2031 recommended_move = null;
2032 var pseudogame = new Chess(display_fen);
2033 var move = pseudogame.move({
2036 promotion: 'q' // NOTE: always promote to a queen for example simplicity
2039 if (current_display_line &&
2040 current_display_move < current_display_line.pv.length - 1 &&
2041 current_display_line.pv[current_display_move + 1] === move.san) {
2046 // Walk down the displayed lines until we find one that starts with
2047 // this move, then select that. Note that this gives us a good priority
2048 // order (history first, then PV, then multi-PV lines).
2049 for (var i = 0; i < display_lines.length; ++i) {
2050 if (i == 1 && current_display_line) {
2051 // Do not choose PV if not on it.
2054 var line = display_lines[i];
2055 if (line.pv[line.start_display_move_num] === move.san) {
2061 // Shouldn't really be here if we have hash probes, but there's really
2062 // nothing we can do.
2064 // End of dragging-related code.
2066 var fmt_cp = function(v) {
2070 return "+" + (v / 100).toFixed(2);
2073 return "-" + (v / 100).toFixed(2);
2077 var format_short_score = function(score) {
2081 if (score[0] === 'm') {
2082 if (score[2]) { // Is a bound.
2083 return score[2] + "\u00a0M " + score[1];
2085 return "M " + score[1];
2087 } else if (score[0] === 'd') {
2089 } else if (score[0] === 'cp') {
2090 if (score[2]) { // Is a bound.
2091 return score[2] + "\u00a0" + fmt_cp(score[1]);
2093 return fmt_cp(score[1]);
2099 var format_long_score = function(score) {
2103 if (score[0] === 'm') {
2105 return "White mates in " + score[1];
2107 return "Black mates in " + (-score[1]);
2109 } else if (score[0] === 'd') {
2110 return "Theoretical draw";
2111 } else if (score[0] === 'cp') {
2112 return "Score: " + format_short_score(score);
2117 var compute_plot_score = function(score) {
2118 if (score[0] === 'm') {
2124 } else if (score[0] === 'd') {
2126 } else if (score[0] === 'cp') {
2127 if (score[1] > 500) {
2129 } else if (score[1] < -500) {
2139 * @param score The score digest tuple.
2140 * @param {?number} depth Depth the move has been computed to, or null.
2141 * @param {boolean} invert Whether black is to play.
2142 * @param {boolean=} depth_secondary_key
2145 var compute_score_sort_key = function(score, depth, invert, depth_secondary_key) {
2150 if (score[0] === 'm') {
2153 s = 99999 - score[1];
2155 // Black mates (note the double negative for score[1]).
2156 s = -99999 - score[1];
2158 } else if (score[0] === 'd') {
2160 } else if (score[0] === 'cp') {
2165 if (depth_secondary_key) {
2166 return s * 200 + (depth || 0);
2176 * @param {Object} game
2178 var switch_backend = function(game) {
2179 // Stop looking at historic data.
2180 current_display_line = null;
2181 current_display_move = null;
2182 displayed_analysis_data = null;
2183 if (current_historic_xhr) {
2184 current_historic_xhr.abort();
2187 // If we already have a backend response going, abort it.
2188 if (current_analysis_xhr) {
2189 current_analysis_xhr.abort();
2191 if (current_hash_xhr) {
2192 current_hash_xhr.abort();
2195 // Otherwise, we should have a timer going to start a new one.
2197 if (current_analysis_request_timer) {
2198 clearTimeout(current_analysis_request_timer);
2199 current_analysis_request_timer = null;
2201 if (current_hash_display_timer) {
2202 clearTimeout(current_hash_display_timer);
2203 current_hash_display_timer = null;
2206 // Request an immediate fetch with the new backend.
2207 backend_url = game['url'];
2208 backend_hash_url = game['hashurl'];
2209 window.location.hash = '#' + game['id'];
2210 current_analysis_data = null;
2214 window['switch_backend'] = switch_backend;
2216 window['flip'] = function() { board.flip(); redraw_arrows(); };
2218 var init = function() {
2219 unique = get_unique();
2221 // Load settings from HTML5 local storage if available.
2222 if (supports_html5_storage() && localStorage['enable_sound']) {
2223 set_sound(parseInt(localStorage['enable_sound']));
2229 board = new window.ChessBoard('board', {
2230 onMoveEnd: function() { board_is_animating = false; },
2233 onDragStart: onDragStart,
2235 onSnapEnd: onSnapEnd
2237 $("#board").on('mousedown', '.square-55d63', mousedownSquare);
2238 $("#board").on('mouseup', '.square-55d63', mouseupSquare);
2241 $(window).resize(function() {
2243 update_sparkline(displayed_analysis_data || current_analysis_data);
2244 update_board_highlight();
2247 $(window).keyup(function(event) {
2248 if (event.which == 39) { // Left arrow.
2250 } else if (event.which == 37) { // Right arrow.
2252 } else if (event.which >= 49 && event.which <= 57) { // 1-9.
2253 var num = event.which - 49;
2254 if (current_games && current_games.length >= num) {
2255 switch_backend(current_games[num]);
2257 } else if (event.which == 78) { // N.
2261 window.addEventListener('hashchange', possibly_switch_game_from_hash, false);
2262 possibly_switch_game_from_hash();
2264 $(document).ready(init);