5 * Version of this script. If the server returns a version larger than
6 * this, it is a sign we should reload to upgrade ourselves.
11 let SCRIPT_VERSION = 2023122700;
14 * The current backend URL.
19 let backend_url = "/analysis.pl";
20 let backend_hash_url = "/hash";
22 /** @type {window.ChessBoard} @private */
25 /** @type {boolean} @private */
26 let board_is_animating = false;
29 * The most recent analysis data we have from the server
30 * (about the most recent position).
34 let current_analysis_data = null;
37 * If we are displaying previous analysis or from hash, this is non-null,
38 * and will override most of current_analysis_data.
43 let displayed_analysis_data = null;
46 * Games currently in progress, if any.
58 let current_games = null;
73 /** @type {Array.<Array.<boolean>>} */
74 let occupied_by_arrows = [];
76 /** Currently displayed refutation lines (on-screen).
77 * Can either come from the current_analysis_data, displayed_analysis_data,
78 * or hash_refutation_lines.
80 * TODO: This is a mess, and we should probably just let update_refutation_lines()
81 * decide anew every time instead of storing the state here in multiple global
92 let refutation_lines = [];
94 /** Refutation lines from current hash probe.
96 * If non-null, will override refutation lines from the base position.
97 * Note that these are relative to display_fen, not base_fen.
99 let hash_refutation_lines = null;
102 * What FEN refutation_lines is relative to. Will usually be base_fen,
103 * but if another move gets loaded while we are looking, they can diverge.
105 let refutation_lines_base_fen = null;
107 /** @type {number} @private */
110 /** @type {boolean} @private */
111 let truncate_display_history = true;
113 /** @type {!string|undefined} @private */
114 let highlight_from = undefined;
116 /** @type {!string|undefined} @private */
117 let highlight_to = undefined;
119 /** The HTML object of the move currently being highlighted (in red).
122 let highlighted_move = null;
124 /** Currently suggested/recommended move when dragging.
125 * @type {?{from: !string, to: !string}}
128 let recommended_move = null;
130 /** If reverse-dragging (dragging from the destination square to the
131 * source square), the destination square.
135 let reverse_dragging_from = null;
137 /** @type {?number} @private */
140 /** @type {?string} @private */
141 let admin_password = null;
143 /** @type {boolean} @private */
144 let enable_sound = false;
146 /** @type {!number} @private */
150 * Our best estimate of how many milliseconds we need to add to
151 * new Date() to get the true UTC time. Calibrated against the
157 let client_clock_offset_ms = null;
159 let clock_timer = null;
161 /** The current position being analyzed, represented as a FEN string.
162 * Note that this is not necessarily the same as display_fen.
168 /** The current position on the board, represented as a FEN string.
169 * Note that board.fen() does not contain e.g. who is to play.
173 let display_fen = null;
177 * pv: Array.<string>,
178 * scores: Array<{first_move: number, score: Object}>,
179 * start_display_move_num: number
182 * "start_display_move_num" is the (half-)move number to start displaying the PV at.
183 * "score" is also evaluated at this point.
187 /** All PVs that we currently know of.
189 * Element 0 is history (or null if no history).
190 * Element 1 is current main PV, or explored line if nowhere else on the screen.
191 * All remaining elements are refutation lines (multi-PV).
193 * @type {Array.<DisplayLine>}
196 let display_lines = [];
198 /** @type {?DisplayLine} @private */
199 let current_display_line = null;
201 /** @type {boolean} @private */
202 let current_display_line_is_history = false;
204 /** @type {?number} @private */
205 let current_display_move = null;
208 * The current backend request to get main analysis (not history), if any,
209 * so that we can abort it.
211 * @type {?AbortController}
214 let current_analysis_xhr = null;
217 * The current timer to fire off a request to get main analysis (not history),
218 * if any, so that we can abort it.
223 let current_analysis_request_timer = null;
226 * The current backend request to get historic data, if any.
228 * @type {?AbortController}
231 let current_historic_xhr = null;
234 * The current backend request to get hash probes, if any, so that we can abort it.
236 * @type {?AbortController}
239 let current_hash_xhr = null;
242 * The current timer to display hash probe information (it could be waiting on the
243 * board to stop animating), if any, so that we can abort it.
248 let current_hash_display_timer = null;
250 function supports_html5_storage() {
252 return 'localStorage' in window && window['localStorage'] !== null;
258 // Make the unique token persistent so people refreshing the page won't count twice.
259 // Of course, you can never fully protect against people deliberately wanting to spam.
260 function get_unique() {
261 let use_local_storage = supports_html5_storage();
262 if (use_local_storage && window['localStorage']['unique']) {
263 return window['localStorage']['unique'];
265 let unique = Math.random();
266 if (use_local_storage) {
267 window['localStorage']['unique'] = unique;
272 function request_update() {
273 current_analysis_request_timer = null;
275 let handle_err = () => {
276 // Backend error or similar. Wait ten seconds, then try again.
277 current_analysis_request_timer = setTimeout(function() { request_update(); }, 10000);
280 current_analysis_xhr = new AbortController();
281 const signal = current_analysis_xhr.signal;
282 fetch(backend_url + "?ims=" + ims + "&unique=" + unique, { signal })
283 .then((response) => response.json().then(data => ({ok: response.ok, headers: response.headers, json: data}))) // ick
290 if (delay_ms === 0) {
291 process_update_response(obj.json, obj.headers);
293 setTimeout(function() { process_update_response(obj.json, obj.headers); }, delay_ms);
297 if (!backend_url.match(/history/)) {
299 current_analysis_request_timer = setTimeout(function() { request_update(); }, timeout);
303 if (err.name === 'AbortError') {
304 // Aborted because we are switching backends. Abandon and don't retry,
305 // because another one is already started for us.
313 document.body.style.opacity = null;
318 function process_update_response(data, headers) {
319 sync_server_clock(headers.get('Date'));
320 ims = headers.get('X-RGLM');
321 let num_viewers = headers.get('X-RGNV');
323 if (Array.isArray(data)) {
324 new_data = JSON.parse(JSON.stringify(current_analysis_data));
325 JSON_delta.patch(new_data, data);
330 let minimum_version = headers.get('X-RGMV');
331 if (minimum_version && minimum_version > SCRIPT_VERSION) {
332 // Upgrade to latest version with a force-reload.
333 location.reload(true);
336 // Verify that the PV makes sense.
338 if (new_data['pv']) {
339 let hiddenboard = new Chess(new_data['position']['fen']);
340 for (let i = 0; i < new_data['pv'].length; ++i) {
341 if (hiddenboard.move(new_data['pv'][i]) === null) {
349 possibly_play_sound(current_analysis_data, new_data);
350 current_analysis_data = new_data;
352 update_num_viewers(num_viewers);
354 console.log("Received invalid update, waiting five seconds and trying again.");
355 setTimeout(function() { location.reload(true); }, 5000);
359 function possibly_play_sound(old_data, new_data) {
363 if (old_data === null) {
366 let ding = document.getElementById('ding');
367 if (ding && ding.play) {
368 if (old_data['position'] && old_data['position']['fen'] &&
369 new_data['position'] && new_data['position']['fen'] &&
370 old_data['position']['fen'] !== new_data['position']['fen']) {
377 * @type {!string} server_date_string
379 function sync_server_clock(server_date_string) {
380 let server_time_ms = new Date(server_date_string).getTime();
381 let client_time_ms = new Date().getTime();
382 let estimated_offset_ms = server_time_ms - client_time_ms;
384 // In order not to let the noise move us too much back and forth
385 // (the server only has one-second resolution anyway), we only
386 // change an existing skew if we are at least five seconds off.
387 if (client_clock_offset_ms === null ||
388 Math.abs(estimated_offset_ms - client_clock_offset_ms) > 5000) {
389 client_clock_offset_ms = estimated_offset_ms;
393 function clear_arrows() {
394 for (let i = 0; i < arrows.length; ++i) {
396 arrows[i].svg.remove();
397 delete arrows[i].svg;
402 occupied_by_arrows = [];
403 for (let y = 0; y < 8; ++y) {
404 occupied_by_arrows.push([false, false, false, false, false, false, false, false]);
408 function redraw_arrows() {
409 for (let i = 0; i < arrows.length; ++i) {
410 position_arrow(arrows[i]);
414 /** @param {!string} fen
417 * Return whose side it is to play (w or b), given a FEN.
419 function find_toplay(fen) {
420 return fen.split(' ')[1];
423 /** @param {!string} fen
426 * Return the move clock, starting from 1. See also find_toplay().
428 function find_move_num(fen) {
429 return parseInt(fen.split(' ')[5]);
432 /** @param {!number} x
445 /** See if drawing this arrow on the board would cause unduly amount of confusion.
446 * @param {!string} from The square the arrow is from (e.g. e4).
447 * @param {!string} to The square the arrow is to (e.g. e4).
450 function interfering_arrow(from, to) {
451 let from_col = from.charCodeAt(0) - "a1".charCodeAt(0);
452 let from_row = from.charCodeAt(1) - "a1".charCodeAt(1);
453 let to_col = to.charCodeAt(0) - "a1".charCodeAt(0);
454 let to_row = to.charCodeAt(1) - "a1".charCodeAt(1);
456 occupied_by_arrows[from_row][from_col] = true;
458 // Knight move: Just check that we haven't been at the destination before.
459 if ((Math.abs(to_col - from_col) == 2 && Math.abs(to_row - from_row) == 1) ||
460 (Math.abs(to_col - from_col) == 1 && Math.abs(to_row - from_row) == 2)) {
461 return occupied_by_arrows[to_row][to_col];
464 // Sliding piece: Check if anything except the from-square is seen before.
465 let dx = sign(to_col - from_col);
466 let dy = sign(to_row - from_row);
472 if (occupied_by_arrows[y][x]) {
475 occupied_by_arrows[y][x] = true;
476 } while (x != to_col || y != to_row);
481 /** Find a point along the coordinate system given by the given line,
482 * <t> units forward from the start of the line, <u> units to the right of it.
483 * @param {!number} x1
484 * @param {!number} x2
485 * @param {!number} y1
486 * @param {!number} y2
489 * @return {!string} The point in "x y" form, suitable for SVG paths.
491 function point_from_start(x1, y1, x2, y2, t, u) {
495 let norm = 1.0 / Math.sqrt(dx * dx + dy * dy);
499 let x = x1 + dx * t + dy * u;
500 let y = y1 + dy * t - dx * u;
504 /** Find a point along the coordinate system given by the given line,
505 * <t> units forward from the end of the line, <u> units to the right of it.
506 * @param {!number} x1
507 * @param {!number} x2
508 * @param {!number} y1
509 * @param {!number} y2
512 * @return {!string} The point in "x y" form, suitable for SVG paths.
514 function point_from_end(x1, y1, x2, y2, t, u) {
518 let norm = 1.0 / Math.sqrt(dx * dx + dy * dy);
522 let x = x2 + dx * t + dy * u;
523 let y = y2 + dy * t - dx * u;
527 function position_arrow(arrow) {
529 if (arrow.svg.parentElement) {
530 arrow.svg.parentElement.removeChild(arrow.svg);
534 if (current_display_line !== null && !current_display_line_is_history) {
538 // We always draw as if the board is 400x400, the viewBox will adjust that for us
539 let line_width = arrow.line_width;
540 let arrow_size = arrow.arrow_size;
542 let square_width = 400 / 8;
543 let from_y, to_y, from_x, to_x;
544 if (board.orientation() === 'black') {
545 from_y = (arrow.from_row + 0.5)*square_width;
546 to_y = (arrow.to_row + 0.5)*square_width;
547 from_x = (7 - arrow.from_col + 0.5)*square_width;
548 to_x = (7 - arrow.to_col + 0.5)*square_width;
550 from_y = (7 - arrow.from_row + 0.5)*square_width;
551 to_y = (7 - arrow.to_row + 0.5)*square_width;
552 from_x = (arrow.from_col + 0.5)*square_width;
553 to_x = (arrow.to_col + 0.5)*square_width;
556 let SVG_NS = "http://www.w3.org/2000/svg";
557 let XHTML_NS = "http://www.w3.org/1999/xhtml";
558 let svg = document.createElementNS(SVG_NS, "svg");
559 svg.setAttribute("width", "100%");
560 svg.setAttribute("height", "100%");
561 svg.setAttribute("viewBox", "0 0 400 400");
562 svg.setAttribute("version", "1.1");
563 svg.setAttribute("class", "c1");
564 svg.setAttribute("xmlns", XHTML_NS);
572 let outline = document.createElementNS(SVG_NS, "path");
573 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));
574 outline.setAttribute("xmlns", XHTML_NS);
575 outline.setAttribute("stroke", "#666");
576 outline.setAttribute("stroke-width", line_width + 2);
577 outline.setAttribute("fill", "none");
578 svg.appendChild(outline);
580 let path = document.createElementNS(SVG_NS, "path");
581 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));
582 path.setAttribute("xmlns", XHTML_NS);
583 path.setAttribute("stroke", arrow.fg_color);
584 path.setAttribute("stroke-width", line_width);
585 path.setAttribute("fill", "none");
586 svg.appendChild(path);
588 // Then the arrow head.
589 let head = document.createElementNS(SVG_NS, "path");
590 head.setAttribute("d",
591 "M " + point_from_end(x1, y1, x2, y2, 0, 0) +
592 " L " + point_from_end(x1, y1, x2, y2, -arrow_size, -arrow_size / 2) +
593 " L " + point_from_end(x1, y1, x2, y2, -arrow_size * .623, 0.0) +
594 " L " + point_from_end(x1, y1, x2, y2, -arrow_size, arrow_size / 2) +
595 " L " + point_from_end(x1, y1, x2, y2, 0, 0));
596 head.setAttribute("xmlns", XHTML_NS);
597 head.setAttribute("stroke", "#000");
598 head.setAttribute("stroke-width", "1");
599 head.setAttribute("fill", arrow.fg_color);
600 svg.appendChild(head);
602 svg.style.position = 'absolute';
603 svg.style.top = '0px'; /* Border for .board-b72b1. */
604 svg.style.left = '0px';
605 svg.style.pointerEvents = 'none';
606 document.getElementById('board').appendChild(svg);
611 * @param {!string} from_square
612 * @param {!string} to_square
613 * @param {!string} fg_color
614 * @param {number} line_width
615 * @param {number} arrow_size
617 function create_arrow(from_square, to_square, fg_color, line_width, arrow_size) {
618 let from_col = from_square.charCodeAt(0) - "a1".charCodeAt(0);
619 let from_row = from_square.charCodeAt(1) - "a1".charCodeAt(1);
620 let to_col = to_square.charCodeAt(0) - "a1".charCodeAt(0);
621 let to_row = to_square.charCodeAt(1) - "a1".charCodeAt(1);
629 line_width: line_width,
630 arrow_size: arrow_size,
634 position_arrow(arrow);
638 function compare_by_score(refutation_lines, invert, a, b) {
639 let sa = compute_score_sort_key(refutation_lines[b]['score'], refutation_lines[b]['depth'], invert);
640 let sb = compute_score_sort_key(refutation_lines[a]['score'], refutation_lines[a]['depth'], invert);
645 * Fake multi-PV using the refutation lines. Find all “relevant” moves,
646 * sorted by quality, descending.
648 * @param {!Object} data
649 * @param {number} margin The maximum number of centipawns worse than the
650 * best move can be and still be included.
651 * @param {boolean} invert Whether black is to play.
652 * @return {Array.<string>} The FEN representation (e.g. Ne4) of all
653 * moves, in score order.
655 function find_nonstupid_moves(data, margin, invert) {
656 // First of all, if there are any moves that are more than 0.5 ahead of
657 // the primary move, the refutation lines are probably bunk, so just
659 let best_score = undefined;
660 let pv_score = undefined;
661 for (let move in data['refutation_lines']) {
662 let line = data['refutation_lines'][move];
663 let score = compute_score_sort_key(line['score'], line['depth'], invert);
664 if (move == data['pv'][0]) {
667 if (best_score === undefined || score > best_score) {
670 if (line['depth'] < 8) {
675 if (best_score - pv_score > 50) {
679 // Now find all moves that are within “margin” of the best score.
680 // The PV move will always be first.
682 for (let move in data['refutation_lines']) {
683 let line = data['refutation_lines'][move];
684 let score = compute_score_sort_key(line['score'], line['depth'], invert);
685 if (move != data['pv'][0] && best_score - score <= margin) {
689 let toplay = find_toplay(data['position']['fen']);
690 moves = moves.sort(function(a, b) { return compare_by_score(data['refutation_lines'], toplay, a, b) });
691 moves.unshift(data['pv'][0]);
700 function thousands(x) {
701 return String(x).split('').reverse().join('').replace(/(\d{3}\B)/g, '$1,').split('').reverse().join('');
705 * @param {!string} start_fen
706 * @param {Array.<string>} pv
707 * @param {Array<{ first_move: number, score: Object }>} scores
708 * @param {number} start_display_move_num
709 * @param {number=} opt_limit
710 * @param {boolean=} opt_showlast
712 function add_pv(start_fen, pv, scores, start_display_move_num, opt_limit, opt_showlast) {
714 start_fen: start_fen,
717 start_display_move_num: start_display_move_num
719 let splicepos = null;
720 if (scores !== null && scores.length >= 1 &&
721 scores[scores.length - 1].score !== undefined &&
722 scores[scores.length - 1].score !== null &&
723 (scores[scores.length - 1].score[0] === 'T' ||
724 scores[scores.length - 1].score[0] === 't')) {
725 splicepos = scores[scores.length - 1].score[1];
727 return print_pv(display_lines.length - 1, splicepos, opt_limit, opt_showlast);
731 * @param {number} line_num
732 * @param {?number} splicepos If non-null, where the tablebase-spliced portion of the TB starts.
733 * @param {number=} opt_limit If set, show at most this number of moves.
734 * @param {boolean=} opt_showlast If limit is set, show the last moves instead of the first ones.
736 function print_pv(line_num, splicepos, opt_limit, opt_showlast) {
737 let display_line = display_lines[line_num];
738 let pv = display_line.pv;
739 let move_num = find_move_num(display_line.start_fen);
740 let toplay = find_toplay(display_line.start_fen);
742 // Truncate PV at the start if needed.
743 let start_display_move_num = display_line.start_display_move_num;
744 if (start_display_move_num > 0) {
745 pv = pv.slice(start_display_move_num);
746 let to_add = start_display_move_num;
747 if (toplay === 'b') {
752 if (to_add % 2 == 1) {
756 move_num += to_add / 2;
757 if (splicepos !== null && splicepos > 0) {
762 let ret = document.createDocumentFragment();
765 if (opt_limit && opt_showlast && pv.length > opt_limit) {
766 // Truncate the PV at the beginning (instead of at the end).
767 // We assume here that toplay is 'w'. We also assume that if
768 // opt_showlast is set, then it is the history, and thus,
769 // the UI should be to expand the history.
770 ret.appendChild(document.createTextNode('('));
771 let link = document.createElement('a');
772 link.className = 'move';
773 link.href = 'javascript:collapse_history(false)';
774 link.textContent = '…';
775 ret.appendChild(link);
776 ret.appendChild(document.createTextNode(') '));
777 i = pv.length - opt_limit;
782 } else if (toplay == 'b' && pv.length > 0) {
783 ret.appendChild(document.createTextNode(move_num + '. … '));
785 for (; i < pv.length; ++i) {
787 if (splicepos === i) {
792 if (toplay == 'b' && i == 0) {
795 } else if (toplay == 'w') {
796 if (i > opt_limit && !opt_showlast) {
800 ret.appendChild(document.createTextNode(prefix + ' (…)'));
803 prefix += ' ' + move_num + '. ';
810 ret.appendChild(document.createTextNode(prefix));
812 let link = document.createElement('a');
813 link.className = 'move';
814 link.setAttribute('id', 'automove' + line_num + '-' + i);
815 link.textContent = pv[i];
816 link.href = 'javascript:show_line(' + line_num + ', ' + i + ');';
817 ret.appendChild(link);
820 ret.appendChild(document.createTextNode(')'));
825 /** Update the highlighted to/from squares on the board.
826 * Based on the global "highlight_from" and "highlight_to" letiables.
828 function update_board_highlight() {
829 document.getElementById("board").querySelectorAll('.square-55d63').forEach((square) => square.classList.remove('nonuglyhighlight'));
830 if ((current_display_line === null || current_display_line_is_history) &&
831 highlight_from !== undefined && highlight_to !== undefined) {
832 document.getElementById("board").querySelector('.square-' + highlight_from).classList.add('nonuglyhighlight');
833 document.getElementById("board").querySelector('.square-' + highlight_to).classList.add('nonuglyhighlight');
837 function update_history() {
838 let history = document.getElementById('history');
839 if (display_lines[0] === null || display_lines[0].pv.length == 0) {
840 history.textContent = 'No history';
841 } else if (truncate_display_history) {
842 history.replaceChildren(print_pv(0, null, 8, true));
844 history.textContent = '(';
845 let link = document.createElement('a');
846 link.className = 'move';
847 link.href = 'javascript:collapse_history(true)';
848 link.textContent = 'collapse';
849 history.appendChild(link);
850 history.appendChild(document.createTextNode(') '));
851 history.append(print_pv(0, null));
856 * @param {!boolean} truncate_history
858 function collapse_history(truncate_history) {
859 truncate_display_history = truncate_history;
862 window['collapse_history'] = collapse_history;
864 /** Update the HTML display of multi-PV from the global "refutation_lines".
866 * Also recreates the global "display_lines".
868 function update_refutation_lines() {
869 if (refutation_lines_base_fen === null) {
872 if (display_lines.length > 2) {
873 // Truncate so that only the history and PV is left.
874 display_lines = [ display_lines[0], display_lines[1] ];
876 let tbl = document.getElementById("refutationlines");
877 tbl.replaceChildren();
879 if (display_lines.length < 2) {
880 // Update the move highlight, as we've rewritten all the HTML.
881 update_move_highlight();
885 // Find out where the lines start from.
887 let base_scores = display_lines[1].scores;
888 let start_display_move_num = 0;
889 if (hash_refutation_lines) {
890 base_line = current_display_line.pv.slice(0, current_display_move + 1);
891 base_scores = current_display_line.scores;
892 start_display_move_num = base_line.length;
896 for (let move in refutation_lines) {
900 let invert = (find_toplay(refutation_lines_base_fen) === 'b');
901 if (current_display_line && current_display_move % 2 == 0 && !current_display_line_is_history) {
904 moves = moves.sort(function(a, b) { return compare_by_score(refutation_lines, invert, a, b) });
905 for (let i = 0; i < moves.length; ++i) {
906 let line = refutation_lines[moves[i]];
908 let tr = document.createElement("tr");
910 let move_td = document.createElement("td");
911 tr.appendChild(move_td);
912 move_td.classList.add("move");
914 let scores = base_scores.concat([{ first_move: start_display_move_num, score: line['score'] }]);
916 if (line['pv'].length == 0) {
917 // Not found, so just make a one-move PV.
918 let link = document.createElement('a');
919 link.className = 'move';
920 link.href = 'javascript:show_line(' + display_lines.length + ', ' + 0 + ')';
921 link.textContent = line['move'];
922 move_td.replaceChildren(link);
924 let score_td = document.createElement("td");
925 score_td.classList.add("score");
926 score_td.textContent = "—";
927 tr.appendChild(score_td);
929 let depth_td = document.createElement("td");
930 tr.appendChild(depth_td);
931 depth_td.classList.add("depth");
932 depth_td.textContent = "—";
934 let pv_td = document.createElement("td");
935 tr.appendChild(pv_td);
936 pv_td.classList.add("pv");
937 pv_td.append(add_pv(refutation_lines_base_fen, base_line.concat([ line['move'] ]), scores, start_display_move_num));
943 let move_link = document.createElement("a");
944 move_link.classList.add("move");
945 move_link.setAttribute("href", "javascript:show_line(" + display_lines.length + ", 0)");
946 move_link.textContent = line['move'];
947 move_td.appendChild(move_link);
949 let score_td = document.createElement("td");
950 tr.appendChild(score_td);
951 score_td.classList.add("score");
952 score_td.textContent = format_short_score(line['score']);
954 let depth_td = document.createElement("td");
955 tr.appendChild(depth_td);
956 depth_td.classList.add("depth");
957 if (line['depth'] && line['depth'] >= 0) {
958 depth_td.textContent = "d" + line['depth'];
960 depth_td.textContent = "—";
963 let pv_td = document.createElement("td");
964 tr.appendChild(pv_td);
965 pv_td.classList.add("pv");
966 pv_td.append(add_pv(refutation_lines_base_fen, base_line.concat(line['pv']), scores, start_display_move_num, 10));
971 // Update the move highlight, as we've rewritten all the HTML.
972 update_move_highlight();
976 * Create a Chess.js board object, containing the given position plus the given moves,
977 * up to the given limit.
979 * @param {?string} fen
980 * @param {Array.<string>} moves
981 * @param {number} last_move
983 function chess_from(fen, moves, last_move) {
984 let hiddenboard = new Chess();
985 if (fen !== null && fen !== undefined) {
986 hiddenboard.load(fen);
988 for (let i = 0; i <= last_move; ++i) {
989 if (moves[i] === '0-0') {
990 hiddenboard.move('O-O');
991 } else if (moves[i] === '0-0-0') {
992 hiddenboard.move('O-O-O');
994 hiddenboard.move(moves[i]);
1000 function update_game_list(games) {
1001 document.getElementById("games").textContent = "";
1002 if (games === null) {
1006 let games_div = document.getElementById('games');
1007 for (let game_num = 0; game_num < games.length; ++game_num) {
1008 let game = games[game_num];
1009 let game_span = document.createElement("span");
1010 game_span.setAttribute("class", "game");
1012 let game_name = document.createTextNode(game['name']);
1013 if (game['url'] === backend_url) {
1015 game_span.appendChild(game_name);
1017 if (current_analysis_data && current_analysis_data['position']) {
1019 if (current_analysis_data['position']['result']) {
1020 score = " (" + current_analysis_data['position']['result'] + ")";
1022 score = " (" + format_short_score(current_analysis_data['score']) + ")";
1024 game_span.appendChild(document.createTextNode(score));
1028 let game_a = document.createElement("a");
1029 game_a.setAttribute("href", "#" + game['id']);
1030 game_a.appendChild(game_name);
1031 game_span.appendChild(game_a);
1034 if (game['result']) {
1035 score = " (" + game['result'] + ")";
1037 score = " (" + format_short_score(game['score']) + ")";
1039 game_span.appendChild(document.createTextNode(score));
1042 games_div.appendChild(game_span);
1047 * Try to find a running game that matches with the current hash,
1048 * and switch to it if we're not already displaying it.
1050 function possibly_switch_game_from_hash() {
1051 let history_match = window.location.hash.match(/^#history=([a-zA-Z0-9_-]+)/);
1052 if (history_match !== null) {
1053 let game_id = history_match[1];
1055 url: '/history/' + game_id + '.json',
1057 id: 'history=' + game_id
1059 switch_backend(fake_game);
1063 if (current_games === null) {
1067 let hash = window.location.hash.replace(/^#/,'');
1068 for (let i = 0; i < current_games.length; ++i) {
1069 if (current_games[i]['id'] === hash) {
1070 if (backend_url !== current_games[i]['url']) {
1071 switch_backend(current_games[i]);
1079 * If this is a Chess960 castling which doesn't move the king,
1080 * move the rook instead.
1082 function patch_move(move) {
1083 if (move === null) return null;
1084 if (move.from !== move.to) return move;
1086 let f = move.rook_sq & 15;
1087 let r = move.rook_sq >> 4;
1088 let from = ('abcdefgh'.substring(f,f+1) + '87654321'.substring(r,r+1));
1091 if (move.to === 'g1') {
1093 } else if (move.to === 'g8') {
1095 } else if (move.to === 'b1') {
1097 } else if (move.to === 'b8') {
1101 return { from: from, to: to };
1104 /** Update all the HTML on the page, based on current global state.
1106 function update_board() {
1107 document.body.style.opacity = null;
1109 let data = displayed_analysis_data || current_analysis_data;
1110 let current_data = current_analysis_data; // Convenience alias.
1114 // Print the history. This is pretty much the only thing that's
1115 // unconditionally taken from current_data (we're not interested in
1116 // historic history).
1117 if (current_data['position']['history']) {
1118 let start = (current_data['position'] && current_data['position']['start_fen']) ? current_data['position']['start_fen'] : 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1';
1119 add_pv(start, current_data['position']['history'], null, 0, 8, true);
1121 display_lines.push(null);
1125 // Games currently in progress, if any.
1126 if (current_data['games']) {
1127 current_games = current_data['games'];
1128 possibly_switch_game_from_hash();
1130 current_games = null;
1132 update_game_list(current_games);
1134 // The headline. Names are always fetched from current_data;
1135 // the rest can depend a bit.
1138 current_data['position']['player_w'] && current_data['position']['player_b']) {
1139 headline = current_data['position']['player_w'] + '–' +
1140 current_data['position']['player_b'] + ', analysis';
1142 headline = 'Analysis';
1145 // Credits: The engine name/version.
1146 if (current_data['engine'] && current_data['engine']['name'] !== null) {
1147 document.getElementById("engineid").textContent = current_data['engine']['name'];
1150 // Credits: The engine URL.
1151 if (current_data['engine'] && current_data['engine']['url']) {
1152 document.getElementById("engineid").setAttribute("href", current_data['engine']['url']);
1154 document.getElementById("engineid").removeAttribute("href");
1157 // Credits: Engine details.
1158 if (current_data['engine'] && current_data['engine']['details']) {
1159 document.getElementById("enginedetails").textContent = " (" + current_data['engine']['details'] + ")";
1161 document.getElementById("enginedetails").textContent = "";
1164 // Credits: Move source, possibly with URL.
1165 if (current_data['move_source'] && current_data['move_source_url']) {
1166 document.getElementById("movesource").textContent = "Moves provided by ";
1167 let movesource_a = document.createElement("a");
1168 movesource_a.setAttribute("href", current_data['move_source_url']);
1169 let movesource_text = document.createTextNode(current_data['move_source']);
1170 movesource_a.appendChild(movesource_text);
1171 let movesource_period = document.createTextNode(".");
1172 document.getElementById("movesource").appendChild(movesource_a);
1173 document.getElementById("movesource").appendChild(movesource_period);
1174 } else if (current_data['move_source']) {
1175 document.getElementById("movesource").textContent = "Moves provided by " + current_data['move_source'] + ".";
1177 document.getElementById("movesource").textContent = "";
1181 if (displayed_analysis_data) {
1182 // Displaying some non-current position, pick out the last move
1183 // from the history. This will work even if the fetch failed.
1184 if (current_display_move !== -1) {
1185 last_move = format_halfmove_with_number(
1186 current_display_line.pv[current_display_move],
1187 current_display_move);
1188 headline += ' after ' + last_move;
1190 } else if (data['position']['last_move'] !== 'none') {
1191 // Find the previous move.
1192 let previous_move_num, previous_toplay;
1193 let fen = data['position']['fen'];
1194 if (find_toplay(fen) === 'b') {
1195 previous_move_num = find_move_num(fen);
1196 previous_toplay = 'w';
1198 previous_move_num = find_move_num(fen) - 1;
1199 previous_toplay = 'b';
1202 last_move = format_move_with_number(
1203 data['position']['last_move'],
1205 previous_toplay == 'w');
1206 headline += ' after ' + last_move;
1210 document.getElementById("headline").textContent = headline;
1212 // The <title> contains a very brief headline.
1213 let title_elems = [];
1214 if (data['position'] && data['position']['result']) {
1215 title_elems.push(data['position']['result']);
1216 } else if (data['score']) {
1217 title_elems.push(format_short_score(data['score']));
1219 if (last_move !== null) {
1220 title_elems.push(last_move);
1223 if (title_elems.length != 0) {
1224 document.title = '(' + title_elems.join(', ') + ') analysis.sesse.net';
1226 document.title = 'analysis.sesse.net';
1229 // The last move (shown by highlighting the from and to squares).
1230 if (data['position'] && data['position']['last_move_uci']) {
1231 highlight_from = data['position']['last_move_uci'].substr(0, 2);
1232 highlight_to = data['position']['last_move_uci'].substr(2, 2);
1233 } else if (current_display_line_is_history && current_display_line && current_display_move >= 0) {
1234 // We don't have historic analysis for this position, but we
1235 // can reconstruct what the last move was by just replaying
1237 let position = (data['position'] && data['position']['start_fen']) ? data['position']['start_fen'] : null;
1238 let hiddenboard = chess_from(position, current_display_line.pv, current_display_move);
1239 let moves = hiddenboard.history({ verbose: true });
1240 last_move = moves.pop();
1241 highlight_from = last_move.from;
1242 highlight_to = last_move.to;
1244 highlight_from = highlight_to = undefined;
1246 update_board_highlight();
1248 if (data['failed']) {
1249 document.getElementById("score").textContent = "No analysis for this move";
1250 document.getElementById("pvtitle").textContent = "PV:";
1251 document.getElementById("pv").replaceChildren();
1252 document.getElementById("searchstats").innerHTML = " ";
1253 document.getElementById("refutationlines").replaceChildren();
1254 document.getElementById("whiteclock").replaceChildren();
1255 document.getElementById("blackclock").replaceChildren();
1256 refutation_lines = [];
1257 refutation_lines_base_fen = null;
1258 update_refutation_lines();
1260 update_displayed_line();
1261 update_move_highlight();
1265 if (clock_timer !== null) {
1266 clearTimeout(clock_timer);
1271 if (current_display_line && !current_display_line_is_history) {
1273 if (current_display_line.scores && current_display_line.scores.length > 0) {
1274 for (let i = 0; i < current_display_line.scores.length; ++i) {
1275 if (current_display_move < current_display_line.scores[i].first_move) {
1278 score = current_display_line.scores[i].score;
1282 document.getElementById("score").textContent = format_long_score(score);
1284 document.getElementById("score").textContent = "No score for this line";
1286 } else if (data['score']) {
1287 document.getElementById("score").textContent = format_long_score(data['score']);
1290 // The search stats.
1291 if (data['searchstats']) {
1292 document.getElementById("searchstats").textContent = data['searchstats'];
1293 } else if (data['nodes'] && data['nps'] && data['depth']) {
1294 let stats = thousands(data['nodes']) + ' nodes, ' + thousands(data['nps']) + ' nodes/sec, depth ' + data['depth'] + ' ply';
1295 if (data['seldepth']) {
1296 stats += ' (' + data['seldepth'] + ' selective)';
1298 if (data['tbhits'] && data['tbhits'] > 0) {
1299 if (data['tbhits'] == 1) {
1300 stats += ', one Syzygy hit';
1302 stats += ', ' + thousands(data['tbhits']) + ' Syzygy hits';
1306 document.getElementById("searchstats").textContent = stats;
1308 document.getElementById("searchstats").textContent = "";
1310 if (admin_password !== null) {
1311 document.getElementById("searchstats").innerHTML += " | <span style=\"color: red;\">ADMIN MODE (if password is right)</span>";
1314 // Update the board itself.
1315 base_fen = data['position']['fen'];
1316 update_displayed_line();
1319 document.getElementById("pvtitle").textContent = "PV:";
1321 let scores = [{ first_move: -1, score: data['score'] }];
1322 document.getElementById("pv").replaceChildren(add_pv(data['position']['fen'], data['pv'], scores, 0));
1324 // Update the PV arrow.
1326 let toplay = find_toplay(data['position']['fen']);
1327 if (data['pv'].length >= 1) {
1328 let hiddenboard = new Chess(base_fen);
1330 // draw a continuation arrow as long as it's the same piece
1332 for (let i = 0; i < data['pv'].length; i += 2) {
1333 let move = patch_move(hiddenboard.move(data['pv'][i]));
1335 if ((i >= 2 && move.from != last_to) ||
1336 interfering_arrow(move.from, move.to)) {
1339 create_arrow(move.from, move.to, '#f66', 6, 20);
1341 hiddenboard.move(data['pv'][i + 1]); // To keep continuity.
1344 let alt_moves = find_nonstupid_moves(data, 30, toplay === 'b');
1345 for (let i = 1; i < alt_moves.length && i < 3; ++i) {
1346 hiddenboard = new Chess(base_fen);
1347 let move = patch_move(hiddenboard.move(alt_moves[i]));
1348 if (move !== null) {
1349 create_arrow(move.from, move.to, '#f66', 1, 10);
1354 // See if all semi-reasonable moves have only one possible response.
1355 if (data['pv'].length >= 2) {
1356 let nonstupid_moves = find_nonstupid_moves(data, 300, toplay === 'b');
1357 let hiddenboard = new Chess(base_fen);
1358 hiddenboard.move(data['pv'][0]);
1359 let response = hiddenboard.move(data['pv'][1]);
1360 for (let i = 0; i < nonstupid_moves.length; ++i) {
1361 if (nonstupid_moves[i] == data['pv'][0]) {
1362 // ignore the PV move for refutation lines.
1365 if (!data['refutation_lines'] ||
1366 !data['refutation_lines'][nonstupid_moves[i]] ||
1367 !data['refutation_lines'][nonstupid_moves[i]]['pv'] ||
1368 data['refutation_lines'][nonstupid_moves[i]]['pv'].length < 2) {
1369 // Incomplete PV, abort.
1370 response = undefined;
1373 let line = data['refutation_lines'][nonstupid_moves[i]];
1374 hiddenboard = new Chess(base_fen);
1375 hiddenboard.move(line['pv'][0]);
1376 let this_response = hiddenboard.move(line['pv'][1]);
1377 if (this_response === null) {
1378 console.log("BUG: ", i);
1380 console.log(line['pv']);
1382 if (response.from !== this_response.from || response.to !== this_response.to) {
1383 // Different response depending on lines, abort.
1384 response = undefined;
1389 if (nonstupid_moves.length > 0 && response !== undefined) {
1390 create_arrow(response.from, response.to, '#66f', 6, 20);
1394 // Update the refutation lines.
1395 base_fen = data['position']['fen'];
1396 if (hash_refutation_lines === null) {
1397 refutation_lines = data['refutation_lines'];
1398 refutation_lines_base_fen = base_fen;
1400 update_refutation_lines();
1402 // Update the sparkline last, since its size depends on how everything else reflowed.
1403 update_sparkline(data);
1406 function update_sparkline(data) {
1407 let scorespark = document.getElementById('scoresparkcontainer');
1408 scorespark.textContent = '';
1409 if (data && data['score_history']) {
1410 let first_move_num = undefined;
1411 for (let halfmove_num in data['score_history']) {
1412 halfmove_num = parseInt(halfmove_num);
1413 if (first_move_num === undefined || halfmove_num < first_move_num) {
1414 first_move_num = halfmove_num;
1417 if (first_move_num !== undefined) {
1418 let fen = data['position']['fen'];
1419 let last_move_num = find_move_num(fen) * 2 - 3;
1420 if (find_toplay(fen) === 'b') {
1424 // Possibly truncate some moves if we don't have enough width.
1425 let max_moves = Math.floor(scorespark.getBoundingClientRect().width / 5) - 3;
1426 if (last_move_num - first_move_num > max_moves) {
1427 first_move_num = last_move_num - max_moves;
1432 let last_score = null;
1434 for (let halfmove_num = first_move_num; halfmove_num <= last_move_num; ++halfmove_num) {
1435 if (data['score_history'][halfmove_num]) {
1436 let score = compute_plot_score(data['score_history'][halfmove_num]);
1438 if (score < min_score) min_score = score;
1439 if (score > max_score) max_score = score;
1441 scores.push(last_score);
1443 if (data['score']) {
1444 let score = compute_plot_score(data['score']);
1446 if (score < min_score) min_score = score;
1447 if (score > max_score) max_score = score;
1449 if (max_score - min_score < 100) {
1450 if (Math.abs(max_score) >= Math.abs(min_score)) {
1451 max_score = min_score + 100;
1453 min_score = max_score - 100;
1457 const h = scorespark.getBoundingClientRect().height;
1459 let base_y = h - h * min_score / (min_score - max_score);
1460 for (let i = 0; i < scores.length; ++i) {
1461 let rect = document.createElementNS('http://www.w3.org/2000/svg', 'rect');
1462 //rect.setAttributeNS(null, 'stroke', "#000000");
1463 rect.setAttributeNS(null, 'x', i * 5)
1464 rect.setAttributeNS(null, 'width', 4);
1465 let extent = scores[i] * h / (max_score - min_score);
1466 if (extent > 0 && extent < 1) {
1468 } else if (extent < 0 && extent > -1) {
1473 if (scores[i] === 0) {
1474 color = [0.5, 0.5, 0.5];
1475 rect.setAttributeNS(null, 'y', base_y);
1476 rect.setAttributeNS(null, 'height', 1);
1477 } else if (scores[i] > 0) {
1478 color = [0.2, 0.4, 0.8];
1479 rect.setAttributeNS(null, 'y', base_y - extent);
1480 rect.setAttributeNS(null, 'height', extent + 1);
1482 color = [1.0, 0.267, 0.267];
1483 rect.setAttributeNS(null, 'y', base_y);
1484 rect.setAttributeNS(null, 'height', -extent + 1);
1486 let hlcolor = [color[0], color[1], color[2]];
1487 if (scores[i] !== 0) {
1488 hlcolor[0] = Math.min(hlcolor[0] * 1.4, 1.0);
1489 hlcolor[1] = Math.min(hlcolor[1] * 1.4, 1.0);
1490 hlcolor[2] = Math.min(hlcolor[2] * 1.4, 1.0);
1492 rect.style.fill = 'rgb(' + color[0]*100.0 + '%, ' + color[1]*100.0 + '%, ' + color[2]*100.0 + '%)';
1494 // score_history contains the Nth _position_, but format_tooltip
1495 // wants to format the Nth _move_; thus the -1.
1496 const tooltip = format_tooltip(data, i + first_move_num - 1);
1497 rect.addEventListener('mouseenter', (e) => draw_hover(e, hlcolor, tooltip));
1498 rect.addEventListener('mousemove', (e) => draw_hover(e, hlcolor, tooltip));
1499 rect.addEventListener('mouseleave', (e) => hide_hover(e, color));
1500 rect.addEventListener('click', (e) => { hide_hover(e, color); show_line(0, i + first_move_num - 1) });
1501 scorespark.appendChild(rect);
1507 function draw_hover(e, color, tooltip) {
1508 e.target.style.fill = 'rgb(' + color[0]*100.0 + '%, ' + color[1]*100.0 + '%, ' + color[2]*100.0 + '%)';
1510 let hover = document.getElementById('sparklinehover');
1511 hover.textContent = tooltip;
1512 hover.style.display = 'initial';
1514 let left = Math.max(e.pageX + 10, window.pageXOffset);
1515 let top = Math.max(e.pageY - hover.getBoundingClientRect().height, window.pageYOffset);
1516 left = Math.min(left, window.pageXOffset + document.documentElement.clientWidth - hover.getBoundingClientRect().width);
1518 hover.style.left = left + 'px';
1519 hover.style.top = top + 'px';
1522 function hide_hover(e, color) {
1523 e.target.style.fill = 'rgb(' + color[0]*100.0 + '%, ' + color[1]*100.0 + '%, ' + color[2]*100.0 + '%)';
1524 document.getElementById('sparklinehover').style.display = 'none';
1528 * @param {number} num_viewers
1530 function update_num_viewers(num_viewers) {
1532 if (num_viewers === null) {
1534 } else if (num_viewers == 1) {
1535 text = "You are the only current viewer";
1537 text = num_viewers + " current viewers";
1539 if (display_fen !== null) {
1540 let counter = Math.floor(display_fen.split(" ")[4] / 2);
1541 if (counter >= 20) {
1542 text = text.replace("current ", "");
1543 text += " | 50-move rule: " + counter;
1546 document.getElementById("numviewers").textContent = text;
1549 function update_clock() {
1552 let data = displayed_analysis_data || current_analysis_data;
1555 if (data['position']) {
1556 let result = data['position']['result'];
1557 if (result === '1-0') {
1558 document.getElementById("whiteclock").textContent = "1";
1559 document.getElementById("blackclock").textContent = "0";
1560 document.getElementById("whiteclock").classList.remove("running-clock");
1561 document.getElementById("blackclock").classList.remove("running-clock");
1564 if (result === '1/2-1/2') {
1565 document.getElementById("whiteclock").textContent = "1/2";
1566 document.getElementById("blackclock").textContent = "1/2";
1567 document.getElementById("whiteclock").classList.remove("running-clock");
1568 document.getElementById("blackclock").classList.remove("running-clock");
1571 if (result === '0-1') {
1572 document.getElementById("whiteclock").textContent = "0";
1573 document.getElementById("blackclock").textContent = "1";
1574 document.getElementById("whiteclock").classList.remove("running-clock");
1575 document.getElementById("blackclock").classList.remove("running-clock");
1580 let white_clock_ms = null;
1581 let black_clock_ms = null;
1584 if (data['position'] &&
1585 data['position']['white_clock'] &&
1586 data['position']['black_clock']) {
1587 white_clock_ms = data['position']['white_clock'] * 1000;
1588 black_clock_ms = data['position']['black_clock'] * 1000;
1591 // Dynamic clock (only one, obviously).
1593 if (data['position']['white_clock_target']) {
1595 document.getElementById("whiteclock").classList.add("running-clock");
1596 document.getElementById("blackclock").classList.remove("running-clock");
1597 } else if (data['position']['black_clock_target']) {
1599 document.getElementById("whiteclock").classList.remove("running-clock");
1600 document.getElementById("blackclock").classList.add("running-clock");
1602 document.getElementById("whiteclock").classList.remove("running-clock");
1603 document.getElementById("blackclock").classList.remove("running-clock");
1607 let now = new Date().getTime() + client_clock_offset_ms;
1608 remaining_ms = data['position'][color + '_clock_target'] * 1000 - now;
1609 if (color === "white") {
1610 white_clock_ms = remaining_ms;
1612 black_clock_ms = remaining_ms;
1616 if (white_clock_ms === null || black_clock_ms === null) {
1617 document.getElementById("whiteclock").replaceChildren();
1618 document.getElementById("blackclock").replaceChildren();
1622 // If either player has twenty minutes or less left, add the second counters.
1623 // This matches what DGT clocks do.
1624 let show_seconds = (white_clock_ms < 60 * 20 * 1000 || black_clock_ms < 60 * 20 * 1000);
1626 if (color && remaining_ms > 0) {
1627 // See when the clock will change next, and update right after that.
1630 next_update_ms = remaining_ms % 1000 + 100;
1632 next_update_ms = remaining_ms % 60000 + 100;
1634 clock_timer = setTimeout(update_clock, next_update_ms);
1637 document.getElementById("whiteclock").textContent = format_clock(white_clock_ms, show_seconds);
1638 document.getElementById("blackclock").textContent = format_clock(black_clock_ms, show_seconds);
1642 * @param {number} remaining_ms
1643 * @param {boolean} show_seconds
1645 function format_clock(remaining_ms, show_seconds) {
1646 if (remaining_ms <= 0) {
1654 let remaining = Math.floor(remaining_ms / 1000);
1655 let seconds = remaining % 60;
1656 remaining = (remaining - seconds) / 60;
1657 let minutes = remaining % 60;
1658 remaining = (remaining - minutes) / 60;
1659 let hours = remaining;
1661 return format_2d(hours) + ":" + format_2d(minutes) + ":" + format_2d(seconds);
1663 return format_2d(hours) + ":" + format_2d(minutes);
1670 function format_2d(x) {
1679 * @param {string} move
1680 * @param {number} move_num Move number of this move.
1681 * @param {boolean} white_to_play Whether white is to play this move.
1683 function format_move_with_number(move, move_num, white_to_play) {
1685 if (white_to_play) {
1686 ret = move_num + '. ';
1688 ret = move_num + '… ';
1695 * @param {string} move
1696 * @param {number} halfmove_num Half-move number that is to be played,
1699 function format_halfmove_with_number(move, halfmove_num) {
1700 return format_move_with_number(
1702 Math.floor(halfmove_num / 2) + 1,
1703 halfmove_num % 2 == 0);
1707 * @param {Object} data
1708 * @param {number} halfmove_num
1710 function format_tooltip(data, halfmove_num) {
1711 if (data['score_history'][halfmove_num + 1] ||
1712 (halfmove_num + 1) === data['position']['history'].length) {
1713 // Position is in the history, or it is the current position
1714 // (which is implicitly tacked onto the history).
1717 if ((halfmove_num + 1) === data['position']['history'].length) {
1718 move = data['position']['last_move'];
1719 short_score = format_short_score(data['score']);
1721 move = data['position']['history'][halfmove_num];
1722 short_score = format_short_score(data['score_history'][halfmove_num + 1]);
1724 if (halfmove_num === -1) {
1725 return "Start position: " + short_score;
1727 let move_with_number = format_halfmove_with_number(move, halfmove_num);
1728 return "After " + move_with_number + ": " + short_score;
1731 for (let i = halfmove_num; i --> -1; ) {
1732 if (data['score_history'][i]) {
1733 let move = data['position']['history'][i];
1735 return "[Analysis kept from start position]";
1737 return "[Analysis kept from " + format_halfmove_with_number(move, i) + "]";
1745 * @param {boolean} truncate_history
1747 function set_truncate_history(truncate_history) {
1748 truncate_display_history = truncate_history;
1749 update_refutation_lines();
1751 window['set_truncate_history'] = set_truncate_history;
1754 * @param {number} line_num
1755 * @param {number} move_num
1757 function show_line(line_num, move_num) {
1758 if (line_num == -1) {
1759 current_display_line = null;
1760 current_display_move = null;
1761 hash_refutation_lines = null;
1762 refutation_lines_base_fen = base_fen;
1763 if (displayed_analysis_data) {
1764 // TODO: Support exiting to history position if we are in an
1765 // analysis line of a history position.
1766 displayed_analysis_data = null;
1771 current_display_line = {...display_lines[line_num]}; // Shallow clone.
1772 current_display_move = move_num + current_display_line.start_display_move_num;
1774 current_display_line_is_history = (line_num == 0);
1776 update_historic_analysis();
1777 update_displayed_line();
1778 update_board_highlight();
1779 update_move_highlight();
1782 window['show_line'] = show_line;
1784 function prev_move() {
1785 if (current_display_line &&
1786 current_display_move >= current_display_line.start_display_move_num) {
1787 --current_display_move;
1789 update_historic_analysis();
1790 update_displayed_line();
1791 update_move_highlight();
1793 window['prev_move'] = prev_move;
1795 function next_move() {
1796 if (current_display_line &&
1797 current_display_move < current_display_line.pv.length - 1) {
1798 ++current_display_move;
1800 update_historic_analysis();
1801 update_displayed_line();
1802 update_move_highlight();
1804 window['next_move'] = next_move;
1806 function next_game() {
1807 if (current_games === null) {
1811 // Try to find the game we are currently looking at.
1812 for (let game_num = 0; game_num < current_games.length; ++game_num) {
1813 let game = current_games[game_num];
1814 if (game['url'] === backend_url) {
1815 let next_game_num = (game_num + 1) % current_games.length;
1816 switch_backend(current_games[next_game_num]);
1821 // Couldn't find it; give up.
1824 function update_historic_analysis() {
1825 if (!current_display_line_is_history) {
1828 if (current_display_move == current_display_line.pv.length - 1) {
1829 displayed_analysis_data = null;
1833 // Fetch old analysis for this line if it exists.
1834 let hiddenboard = chess_from(current_display_line.start_fen, current_display_line.pv, current_display_move);
1835 let filename = "/history/move" + (current_display_move + 1) + "-" +
1836 hiddenboard.fen().replace(/ /g, '_').replace(/\//g, '-') + ".json";
1838 let handle_err = () => {
1839 displayed_analysis_data = {'failed': true};
1843 current_historic_xhr = new AbortController();
1844 const signal = current_analysis_xhr.signal;
1845 fetch(filename, { signal })
1846 .then((response) => response.json().then(data => ({ok: response.ok, json: data}))) // ick
1852 displayed_analysis_data = obj.json;
1856 if (err.name === 'AbortError') {
1857 // Aborted because we are switching backends. Abandon and don't retry,
1858 // because another one is already started for us.
1867 * @param {string} fen
1869 function update_imbalance(fen) {
1870 let imbalance = {'k': 0, 'q': 0, 'r': 0, 'b': 0, 'n': 0, 'p': 0};
1871 for (const c of fen) {
1876 if (c != c.toUpperCase()) {
1878 } else if (c != c.toLowerCase()) {
1879 ++imbalance[c.toLowerCase()];
1883 let white_imbalance = document.getElementById('whiteimbalance');
1884 let black_imbalance = document.getElementById('blackimbalance');
1885 white_imbalance.textContent = '';
1886 black_imbalance.textContent = '';
1887 for (let piece in imbalance) {
1888 for (let i = 0; i < imbalance[piece]; ++i) {
1889 let i1 = document.createElement('img');
1890 i1.src = svg_pieces['w' + piece.toUpperCase()];
1891 i1.setAttribute('alt', piece.toUpperCase());
1892 i1.classList.add('imbalance-piece');
1893 white_imbalance.appendChild(i1);
1895 let i2 = document.createElement('img');
1896 i2.src = svg_pieces['b' + piece.toUpperCase()];
1897 i2.setAttribute('alt', piece.toUpperCase());
1898 i2.classList.add('imbalance-inverted-piece');
1899 white_imbalance.appendChild(i2);
1901 for (let i = 0; i < -imbalance[piece]; ++i) {
1902 let i1 = document.createElement('img');
1903 i1.src = svg_pieces['b' + piece.toUpperCase()];
1904 i1.setAttribute('alt', piece.toUpperCase());
1905 i1.classList.add('imbalance-piece');
1906 black_imbalance.appendChild(i1);
1908 let i2 = document.createElement('img');
1909 i2.src = svg_pieces['w' + piece.toUpperCase()];
1910 i2.setAttribute('alt', piece.toUpperCase());
1911 i2.classList.add('imbalance-inverted-piece');
1912 black_imbalance.appendChild(i2);
1917 /** Mark the currently selected move in red.
1918 * Also replaces the PV with the current displayed line if it's not shown
1919 * anywhere else on the screen.
1921 function update_move_highlight() {
1922 if (highlighted_move !== null) {
1923 highlighted_move.classList.remove('highlight');
1925 if (current_display_line) {
1926 let display_line_num = find_display_line_matching_num();
1927 if (display_line_num === null) {
1928 // Replace the PV with the (complete) line.
1929 document.getElementById("pvtitle").textContent = "Exploring:";
1930 current_display_line.start_display_move_num = 0;
1931 display_lines.push(current_display_line);
1932 document.getElementById("pv").replaceChildren(print_pv(display_lines.length - 1, null)); // FIXME
1933 display_line_num = display_lines.length - 1;
1935 // Clear out the PV, so it's not selected by anything later.
1936 display_lines[1].pv = [];
1939 highlighted_move = document.getElementById("automove" + display_line_num + "-" + (current_display_move - current_display_line.start_display_move_num));
1940 if (highlighted_move !== null) {
1941 highlighted_move.classList.add('highlight');
1947 * See if the current displayed line is identical to any of the ones
1948 * we have on screen. (It might not be if e.g. the analysis reloaded
1949 * since we started looking.)
1953 function find_display_line_matching_num() {
1954 for (let i = 0; i < display_lines.length; ++i) {
1955 let line = display_lines[i];
1956 if (line.start_display_move_num > 0) continue;
1957 if (current_display_line.start_fen !== line.start_fen) continue;
1958 if (current_display_line.pv.length !== line.pv.length) continue;
1960 for (let j = 0; j < line.pv.length; ++j) {
1961 if (current_display_line.pv[j] !== line.pv[j]) {
1973 /** Update the board based on the currently displayed line.
1975 * TODO: This should really be called only whenever something changes,
1976 * instead of all the time.
1978 function update_displayed_line() {
1979 if (current_display_line === null) {
1980 document.getElementById("linenav").style.display = 'none';
1981 document.getElementById("linemsg").style.display = 'revert';
1982 display_fen = base_fen;
1983 set_board_position(base_fen);
1984 update_imbalance(base_fen);
1988 document.getElementById("linenav").style.display = 'revert';
1989 document.getElementById("linemsg").style.display = 'none';
1991 if (current_display_move <= 0) {
1992 document.getElementById("prevmove").textContent = "Previous";
1994 document.getElementById("prevmove").innerHTML = "<a href=\"javascript:prev_move();\">Previous</a></span>";
1996 if (current_display_move == current_display_line.pv.length - 1) {
1997 document.getElementById("nextmove").textContent = "Next";
1999 document.getElementById("nextmove").innerHTML = "<a href=\"javascript:next_move();\">Next</a></span>";
2002 let hiddenboard = chess_from(current_display_line.start_fen, current_display_line.pv, current_display_move);
2003 set_board_position(hiddenboard.fen());
2004 if (display_fen !== hiddenboard.fen() && !current_display_line_is_history) {
2005 // Fire off a hash request, since we're now off the main position
2006 // and it just changed.
2007 explore_hash(hiddenboard.fen());
2009 display_fen = hiddenboard.fen();
2010 update_imbalance(hiddenboard.fen());
2013 function set_board_position(new_fen) {
2014 board_is_animating = true;
2015 let old_fen = board.fen();
2016 let animate = old_fen !== '8/8/8/8/8/8/8/';
2017 board.position(new_fen, animate);
2018 if (board.fen() === old_fen) {
2019 board_is_animating = false;
2024 * @param {boolean} param_enable_sound
2026 function set_sound(param_enable_sound) {
2027 enable_sound = param_enable_sound;
2029 document.getElementById("soundon").innerHTML = "<strong>On</strong>";
2030 document.getElementById("soundoff").innerHTML = "<a href=\"javascript:set_sound(false)\">Off</a>";
2032 // Seemingly at least Firefox prefers MP3 over Opus; tell it otherwise,
2033 // and also preload the file since the user has selected audio.
2034 let ding = document.getElementById('ding');
2035 if (ding && ding.canPlayType && ding.canPlayType('audio/ogg; codecs="opus"') === 'probably') {
2036 ding.src = 'ding.opus';
2040 document.getElementById("soundon").innerHTML = "<a href=\"javascript:set_sound(true)\">On</a>";
2041 document.getElementById("soundoff").innerHTML = "<strong>Off</strong>";
2043 if (supports_html5_storage()) {
2044 window['localStorage']['enable_sound'] = enable_sound ? 1 : 0;
2047 window['set_sound'] = set_sound;
2049 /** Send off a hash probe request to the backend.
2050 * @param {string} fen
2052 function explore_hash(fen) {
2053 // If we already have a backend response going, abort it.
2054 if (current_hash_xhr) {
2055 current_hash_xhr.abort();
2057 if (current_hash_display_timer) {
2058 clearTimeout(current_hash_display_timer);
2059 current_hash_display_timer = null;
2061 document.getElementById("refutationlines").replaceChildren();
2063 current_hash_xhr = new AbortController();
2064 const signal = current_analysis_xhr.signal;
2065 fetch(backend_hash_url + "?fen=" + fen, { signal })
2066 .then((response) => response.json())
2067 .then((data) => { show_explore_hash_results(data, fen); })
2069 // Truncate the lines, since we already cleared the display.
2070 display_lines = [ display_lines[0], display_lines[1] ];
2071 update_move_highlight();
2075 /** Process the JSON response from a hash probe request.
2076 * @param {!Object} data
2077 * @param {string} fen
2079 function show_explore_hash_results(data, fen) {
2080 if (board_is_animating) {
2081 // Updating while the animation is still going causes
2082 // the animation to jerk. This is pretty crude, but it will do.
2083 current_hash_display_timer = setTimeout(function() { show_explore_hash_results(data, fen); }, 100);
2086 current_hash_display_timer = null;
2087 hash_refutation_lines = data['lines'];
2088 refutation_lines_base_fen = fen;
2092 // almost all of this stuff comes from the chessboard.js example page
2093 function onDragStart(source, piece, position, orientation) {
2094 let pseudogame = new Chess(display_fen);
2095 if (pseudogame.game_over() === true ||
2096 (pseudogame.turn() === 'w' && piece.search(/^b/) !== -1) ||
2097 (pseudogame.turn() === 'b' && piece.search(/^w/) !== -1)) {
2101 recommended_move = get_best_move(pseudogame, source, null, pseudogame.turn() === 'b');
2102 if (recommended_move) {
2103 let squareEl = document.querySelector('#board .square-' + recommended_move.to);
2104 squareEl.classList.add('highlight1-32417');
2109 function mousedownSquare(e) {
2110 if (!e.target || !e.target.getAttribute('data-square')) {
2114 reverse_dragging_from = null;
2115 let square = e.target.getAttribute('data-square');
2117 let pseudogame = new Chess(display_fen);
2118 if (pseudogame.game_over() === true) {
2122 // If the square is empty, or has a piece of the side not to move,
2123 // we handle it. If not, normal piece dragging will take it.
2124 let position = board.position();
2125 if (!position.hasOwnProperty(square) ||
2126 (pseudogame.turn() === 'w' && position[square].search(/^b/) !== -1) ||
2127 (pseudogame.turn() === 'b' && position[square].search(/^w/) !== -1)) {
2128 reverse_dragging_from = square;
2129 recommended_move = get_best_move(pseudogame, null, square, pseudogame.turn() === 'b');
2130 if (recommended_move) {
2131 let squareEl = document.querySelector('#board .square-' + recommended_move.from);
2132 squareEl.classList.add('highlight1-32417');
2133 squareEl = document.querySelector('#board .square-' + recommended_move.to);
2134 squareEl.classList.add('highlight1-32417');
2139 function mouseupSquare(e) {
2140 if (!e.target || !e.target.getAttribute('data-square')) {
2143 if (reverse_dragging_from === null) {
2146 let source = e.target.getAttribute('data-square');
2147 let target = reverse_dragging_from;
2148 reverse_dragging_from = null;
2149 if (onDrop(source, target) !== 'snapback') {
2150 onSnapEnd(source, target);
2152 document.getElementById("board").querySelectorAll('.square-55d63.highlight1-32417').forEach((square) => {
2153 square.classList.remove('highlight1-32417');
2157 function get_best_move(game, source, target, invert) {
2158 let moves = game.moves({ verbose: true });
2159 if (source !== null) {
2160 moves = moves.filter(function(move) { return move.from == source; });
2162 if (target !== null) {
2163 moves = moves.filter(function(move) { return move.to == target; });
2165 if (moves.length == 0) {
2168 if (moves.length == 1) {
2172 // More than one move. Use the display lines (if we have them)
2173 // to disambiguate; otherwise, we have no information.
2175 for (let i = 0; i < moves.length; ++i) {
2176 move_hash[moves[i].san] = moves[i];
2179 // See if we're already exploring some line.
2180 if (current_display_line &&
2181 current_display_move < current_display_line.pv.length - 1) {
2182 let first_move = current_display_line.pv[current_display_move + 1];
2183 if (move_hash[first_move]) {
2184 return move_hash[first_move];
2188 // History and PV take priority over the display lines.
2189 for (let i = 0; i < 2; ++i) {
2190 let line = display_lines[i];
2191 let first_move = line.pv[line.start_display_move_num];
2192 if (move_hash[first_move]) {
2193 return move_hash[first_move];
2197 let best_move = null;
2198 let best_move_score = null;
2200 for (let move in refutation_lines) {
2201 let line = refutation_lines[move];
2202 if (!line['score']) {
2205 let first_move = line['pv'][0];
2206 if (move_hash[first_move]) {
2207 let score = compute_score_sort_key(line['score'], line['depth'], invert);
2208 if (best_move_score === null || score > best_move_score) {
2209 best_move = move_hash[first_move];
2210 best_move_score = score;
2217 function onDrop(source, target) {
2218 if (source === target) {
2219 if (recommended_move === null) {
2222 // Accept the move. It will be changed in onSnapEnd.
2226 // Suggestion not asked for.
2227 recommended_move = null;
2230 // see if the move is legal
2231 let pseudogame = new Chess(display_fen);
2232 let move = pseudogame.move({
2235 promotion: 'q' // NOTE: always promote to a queen for example simplicity
2239 if (move === null) return 'snapback';
2243 * If we are in admin mode, send this move to the backend.
2245 * @param {string} fen
2246 * @param {string} move
2248 function send_chosen_move(fen, move) {
2249 if (admin_password !== null) {
2250 let history = current_analysis_data['position']['history'];
2251 let url = '/manual-override.pl';
2252 url += '?fen=' + encodeURIComponent(fen);
2253 url += '&history=' + encodeURIComponent(JSON.stringify(history));
2254 url += '&move=' + encodeURIComponent(move);
2255 url += '&player_w=' + encodeURIComponent(current_analysis_data['position']['player_w']);
2256 url += '&player_b=' + encodeURIComponent(current_analysis_data['position']['player_b']);
2257 url += '&password=' + encodeURIComponent(admin_password);
2259 console.log(fen, history);
2260 fetch(url); // Ignore the result.
2264 function onSnapEnd(source, target) {
2265 if (source === target && recommended_move !== null) {
2266 source = recommended_move.from;
2267 target = recommended_move.to;
2269 recommended_move = null;
2270 let pseudogame = new Chess(display_fen);
2271 let move = pseudogame.move({
2274 promotion: 'q' // NOTE: always promote to a queen for example simplicity
2277 if (admin_password !== null) {
2278 send_chosen_move(display_fen, move.san);
2282 // Move ahead on the line we're on -- this includes history if we've
2284 if (current_display_line &&
2285 current_display_move < current_display_line.pv.length - 1 &&
2286 current_display_line.pv[current_display_move + 1] === move.san) {
2291 // Walk down the displayed lines until we find one that starts with
2292 // this move, then select that. Note that this gives us a good priority
2293 // order (PV, then multi-PV lines; history was already dealt with above,
2294 // as it's the only line that originates backwards).
2295 for (let i = 1; i < display_lines.length; ++i) {
2296 if (i == 1 && current_display_line) {
2297 // Do not choose PV if not on it.
2300 let line = display_lines[i];
2301 if (line.pv[line.start_display_move_num] === move.san) {
2307 // Shouldn't really be here if we have hash probes, but there's really
2308 // nothing we can do.
2309 // FIXME: Just make a new line, probably (even if we don't have hash moves).
2310 // As it is, we can actually drag (but not click) such a move in the UI,
2311 // but it has no effect on what we're probing.
2313 // End of dragging-related code.
2315 function fmt_cp(v) {
2319 return "+" + (v / 100).toFixed(2);
2322 return "-" + (v / 100).toFixed(2);
2326 function format_short_score(score) {
2330 if (score[0] === 'T' || score[0] === 't') {
2331 let ret = "TB\u00a0";
2332 if (score[2]) { // Is a bound.
2333 ret = score[2] + "\u00a0TB\u00a0";
2335 if (score[0] === 'T') {
2336 return ret + Math.ceil(score[1] / 2);
2338 return ret + "-" + Math.ceil(score[1] / 2);
2340 } else if (score[0] === 'M' || score[0] === 'm') {
2341 let sign = (score[0] === 'm') ? '-' : '';
2342 if (score[2]) { // Is a bound.
2343 return score[2] + "\u00a0M " + sign + score[1];
2345 return "M " + sign + score[1];
2347 } else if (score[0] === 'd') {
2349 } else if (score[0] === 'cp') {
2350 if (score[2]) { // Is a bound.
2351 return score[2] + "\u00a0" + fmt_cp(score[1]);
2353 return fmt_cp(score[1]);
2359 function format_long_score(score) {
2363 if (score[0] === 'T') {
2364 if (score[1] == 0) {
2365 return "Won for white (tablebase)";
2367 return "White wins in " + Math.ceil(score[1] / 2);
2369 } else if (score[0] === 't') {
2370 if (score[1] == -1) {
2371 return "Won for black (tablebase)";
2373 return "Black wins in " + Math.ceil(score[1] / 2);
2375 } else if (score[0] === 'M') {
2376 if (score[1] == 0) {
2377 return "White wins by checkmate";
2379 return "White mates in " + score[1];
2381 } else if (score[0] === 'm') {
2382 if (score[1] == 0) {
2383 return "Black wins by checkmate";
2385 return "Black mates in " + score[1];
2387 } else if (score[0] === 'd') {
2388 return "Theoretical draw";
2389 } else if (score[0] === 'cp') {
2390 return "Score: " + format_short_score(score);
2395 function compute_plot_score(score) {
2396 if (score[0] === 'M' || score[0] === 'T') {
2398 } else if (score[0] === 'm' || score[0] === 't') {
2400 } else if (score[0] === 'd') {
2402 } else if (score[0] === 'cp') {
2403 if (score[1] > 500) {
2405 } else if (score[1] < -500) {
2415 * @param score The score digest tuple.
2416 * @param {?number} depth Depth the move has been computed to, or null.
2417 * @param {boolean} invert Whether black is to play.
2420 function compute_score_sort_key(score, depth, invert) {
2425 if (score[0] === 'T') {
2426 // White reaches TB win.
2427 s = 89999 - score[1];
2428 } else if (score[0] === 't') {
2429 // Black reaches TB win.
2430 s = -(89999 - score[1]);
2431 } else if (score[0] === 'M') {
2433 s = 99999 - score[1];
2434 } else if (score[0] === 'm') {
2436 s = -(99999 - score[1]);
2437 } else if (score[0] === 'd') {
2439 } else if (score[0] === 'cp') {
2451 * @param {Object} game
2453 function switch_backend(game) {
2454 // Stop looking at historic data.
2455 current_display_line = null;
2456 current_display_move = null;
2457 displayed_analysis_data = null;
2458 if (current_historic_xhr) {
2459 current_historic_xhr.abort();
2462 // If we already have a backend response going, abort it.
2463 if (current_analysis_xhr) {
2464 current_analysis_xhr.abort();
2466 if (current_hash_xhr) {
2467 current_hash_xhr.abort();
2470 // Otherwise, we should have a timer going to start a new one.
2472 if (current_analysis_request_timer) {
2473 clearTimeout(current_analysis_request_timer);
2474 current_analysis_request_timer = null;
2476 if (current_hash_display_timer) {
2477 clearTimeout(current_hash_display_timer);
2478 current_hash_display_timer = null;
2481 // Request an immediate fetch with the new backend.
2482 backend_url = game['url'];
2483 backend_hash_url = game['hashurl'];
2484 window.location.hash = '#' + game['id'];
2485 current_analysis_data = null;
2489 window['switch_backend'] = switch_backend;
2491 window['flip'] = function() { board.flip(); redraw_arrows(); };
2492 window['set_delay_ms'] = function(ms) { delay_ms = ms; console.log('Delay is now ' + ms + ' ms.'); };
2494 // Mostly from Wikipedia's chess set as of October 2022, but some pieces are from
2495 // the 2013 version, as I like those better (and it matches the 2014 PNGs; nobody
2496 // really likes change, do they?). That is wK, bK, bQ. wQ is also slightly different,
2497 // but not enough to notice.
2498 const svg_pieces = {
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2500 'wQ': 'data:image/svg+xml,<?xml version=%221.0%22 encoding=%22UTF-8%22 standalone=%22no%22?>%0A<!DOCTYPE svg PUBLIC %22-//W3C//DTD SVG 1.1//EN%22 %22http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd%22>%0A<svg xmlns=%22http://www.w3.org/2000/svg%22 version=%221.1%22 width=%2245%22 height=%2245%22><g style=%22fill:%23ffffff;stroke:%23000000;stroke-width:1.5;stroke-linejoin:round%22><path d=%22M 9,26 C 17.5,24.5 30,24.5 36,26 L 38.5,13.5 L 31,25 L 30.7,10.9 L 25.5,24.5 L 22.5,10 L 19.5,24.5 L 14.3,10.9 L 14,25 L 6.5,13.5 L 9,26 z%22/><path d=%22M 9,26 C 9,28 10.5,28 11.5,30 C 12.5,31.5 12.5,31 12,33.5 C 10.5,34.5 11,36 11,36 C 9.5,37.5 11,38.5 11,38.5 C 17.5,39.5 27.5,39.5 34,38.5 C 34,38.5 35.5,37.5 34,36 C 34,36 34.5,34.5 33,33.5 C 32.5,31 32.5,31.5 33.5,30 C 34.5,28 36,28 36,26 C 27.5,24.5 17.5,24.5 9,26 z%22/><path d=%22M 11.5,30 C 15,29 30,29 33.5,30%22 style=%22fill:none%22/><path d=%22M 12,33.5 C 18,32.5 27,32.5 33,33.5%22 style=%22fill:none%22/><circle cx=%226%22 cy=%2212%22 r=%222%22/><circle cx=%2214%22 cy=%229%22 r=%222%22/><circle cx=%2222.5%22 cy=%228%22 r=%222%22/><circle cx=%2231%22 cy=%229%22 r=%222%22/><circle cx=%2239%22 cy=%2212%22 r=%222%22/></g></svg>',
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2503 'wN': 'data:image/svg+xml,<?xml version=%221.0%22 encoding=%22UTF-8%22 standalone=%22no%22?>%0A<!DOCTYPE svg PUBLIC %22-//W3C//DTD SVG 1.1//EN%22 %22http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd%22>%0A<svg xmlns=%22http://www.w3.org/2000/svg%22 version=%221.1%22 width=%2245%22 height=%2245%22><g style=%22opacity:1;fill:none;fill-opacity:1;fill-rule:evenodd;stroke:%23000000;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22 transform=%22translate(0,0.3)%22><path d=%22M 22,10 C 32.5,11 38.5,18 38,39 L 15,39 C 15,30 25,32.5 23,18%22 style=%22fill:%23ffffff;stroke:%23000000%22/><path d=%22M 24,18 C 24.38,20.91 18.45,25.37 16,27 C 13,29 13.18,31.34 11,31 C 9.958,30.06 12.41,27.96 11,28 C 10,28 11.19,29.23 10,30 C 9,30 5.997,31 6,26 C 6,24 12,14 12,14 C 12,14 13.89,12.1 14,10.5 C 13.27,9.506 13.5,8.5 13.5,7.5 C 14.5,6.5 16.5,10 16.5,10 L 18.5,10 C 18.5,10 19.28,8.008 21,7 C 22,7 22,10 22,10%22 style=%22fill:%23ffffff;stroke:%23000000%22/><path d=%22M 9.5 25.5 A 0.5 0.5 0 1 1 8.5,25.5 A 0.5 0.5 0 1 1 9.5 25.5 z%22 style=%22fill:%23000000;stroke:%23000000%22/><path d=%22M 15 15.5 A 0.5 1.5 0 1 1 14,15.5 A 0.5 1.5 0 1 1 15 15.5 z%22 transform=%22matrix(0.866,0.5,-0.5,0.866,9.693,-5.173)%22 style=%22fill:%23000000;stroke:%23000000%22/></g></svg>',
2504 'wP': 'data:image/svg+xml,<?xml version=%221.0%22 encoding=%22UTF-8%22 standalone=%22no%22?>%0A<!DOCTYPE svg PUBLIC %22-//W3C//DTD SVG 1.1//EN%22 %22http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd%22>%0A<svg xmlns=%22http://www.w3.org/2000/svg%22 version=%221.1%22 width=%2245%22 height=%2245%22><path d=%22m 22.5,9 c -2.21,0 -4,1.79 -4,4 0,0.89 0.29,1.71 0.78,2.38 C 17.33,16.5 16,18.59 16,21 c 0,2.03 0.94,3.84 2.41,5.03 C 15.41,27.09 11,31.58 11,39.5 H 34 C 34,31.58 29.59,27.09 26.59,26.03 28.06,24.84 29,23.03 29,21 29,18.59 27.67,16.5 25.72,15.38 26.21,14.71 26.5,13.89 26.5,13 c 0,-2.21 -1.79,-4 -4,-4 z%22 style=%22opacity:1;fill:%23ffffff;fill-opacity:1;fill-rule:nonzero;stroke:%23000000;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22/></svg>',
2505 'bK': 'data:image/svg+xml,<?xml version=%221.0%22 encoding=%22UTF-8%22 standalone=%22no%22?>%0A<!DOCTYPE svg PUBLIC %22-//W3C//DTD SVG 1.1//EN%22 %22http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd%22>%0A<svg xmlns=%22http://www.w3.org/2000/svg%22 version=%221.1%22 width=%2245%22 height=%2245%22><g style=%22fill:none;fill-opacity:1;fill-rule:evenodd;stroke:%23000000;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22><path d=%22M 22.5,11.63 L 22.5,6%22 style=%22fill:none;stroke:%23000000;stroke-linejoin:miter%22 id=%22path6570%22/><path d=%22M 22.5,25 C 22.5,25 27,17.5 25.5,14.5 C 25.5,14.5 24.5,12 22.5,12 C 20.5,12 19.5,14.5 19.5,14.5 C 18,17.5 22.5,25 22.5,25%22 style=%22fill:%23000000;fill-opacity:1;stroke-linecap:butt;stroke-linejoin:miter%22/><path d=%22M 11.5,37 C 17,40.5 27,40.5 32.5,37 L 32.5,30 C 32.5,30 41.5,25.5 38.5,19.5 C 34.5,13 25,16 22.5,23.5 L 22.5,27 L 22.5,23.5 C 19,16 9.5,13 6.5,19.5 C 3.5,25.5 11.5,29.5 11.5,29.5 L 11.5,37 z %22 style=%22fill:%23000000;stroke:%23000000%22/><path d=%22M 20,8 L 25,8%22 style=%22fill:none;stroke:%23000000;stroke-linejoin:miter%22/><path d=%22M 32,29.5 C 32,29.5 40.5,25.5 38.03,19.85 C 34.15,14 25,18 22.5,24.5 L 22.51,26.6 L 22.5,24.5 C 20,18 9.906,14 6.997,19.85 C 4.5,25.5 11.85,28.85 11.85,28.85%22 style=%22fill:none;stroke:%23ffffff%22/><path d=%22M 11.5,30 C 17,27 27,27 32.5,30 M 11.5,33.5 C 17,30.5 27,30.5 32.5,33.5 M 11.5,37 C 17,34 27,34 32.5,37%22 style=%22fill:none;stroke:%23ffffff%22/></g></svg>',
2506 'bQ': 'data:image/svg+xml,<?xml version=%221.0%22 encoding=%22UTF-8%22 standalone=%22no%22?>%0A<!DOCTYPE svg PUBLIC %22-//W3C//DTD SVG 1.1//EN%22 %22http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd%22>%0A<svg xmlns:svg=%22http://www.w3.org/2000/svg%22 xmlns=%22http://www.w3.org/2000/svg%22 version=%221.1%22 width=%2245%22 height=%2245%22 id=%22svg3128%22><defs/><g id=%22layer1%22><path d=%22M 8 12 A 2 2 0 1 1 4,12 A 2 2 0 1 1 8 12 z%22 style=%22opacity:1;fill:%23000000;fill-opacity:1;stroke:%23000000;stroke-width:1;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22 id=%22path5571%22/><path d=%22M 9 13 A 2 2 0 1 1 5,13 A 2 2 0 1 1 9 13 z%22 transform=%22translate(15.5,-5.5)%22 style=%22opacity:1;fill:%23000000;fill-opacity:1;stroke:%23000000;stroke-width:1;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22 id=%22path5573%22/><path d=%22M 9 13 A 2 2 0 1 1 5,13 A 2 2 0 1 1 9 13 z%22 transform=%22translate(32,-1)%22 style=%22opacity:1;fill:%23000000;fill-opacity:1;stroke:%23000000;stroke-width:1;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22 id=%22path5575%22/><path d=%22M 9 13 A 2 2 0 1 1 5,13 A 2 2 0 1 1 9 13 z%22 transform=%22translate(7,-4.5)%22 style=%22opacity:1;fill:%23000000;fill-opacity:1;stroke:%23000000;stroke-width:1;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22 id=%22path5577%22/><path d=%22M 9 13 A 2 2 0 1 1 5,13 A 2 2 0 1 1 9 13 z%22 transform=%22translate(24,-4)%22 style=%22opacity:1;fill:%23000000;fill-opacity:1;stroke:%23000000;stroke-width:1;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22 id=%22path5579%22/><path d=%22M 9,26 C 17.5,24.5 30,24.5 36,26 L 38,14 L 31,25 L 31,11 L 25.5,24.5 L 22.5,9.5 L 19.5,24.5 L 14,10.5 L 14,25 L 7,14 L 9,26 z %22 style=%22fill:%23000000;fill-opacity:1;fill-rule:evenodd;stroke:%23000000;stroke-width:1px;stroke-linecap:butt;stroke-linejoin:round;stroke-opacity:1%22 id=%22path5581%22/><path d=%22M 9,26 C 9,28 10.5,28 11.5,30 C 12.5,31.5 12.5,31 12,33.5 C 10.5,34.5 10.5,36 10.5,36 C 9,37.5 11,38.5 11,38.5 C 17.5,39.5 27.5,39.5 34,38.5 C 34,38.5 35.5,37.5 34,36 C 34,36 34.5,34.5 33,33.5 C 32.5,31 32.5,31.5 33.5,30 C 34.5,28 36,28 36,26 C 27.5,24.5 17.5,24.5 9,26 z %22 style=%22fill:%23000000;fill-opacity:1;fill-rule:evenodd;stroke:%23000000;stroke-width:1px;stroke-linecap:butt;stroke-linejoin:round;stroke-opacity:1%22 id=%22path5583%22/><path d=%22M 11.5,30 C 15,29 30,29 33.5,30%22 style=%22fill:none;fill-opacity:0.75;fill-rule:evenodd;stroke:%23ffffff;stroke-width:1px;stroke-linecap:round;stroke-linejoin:round;stroke-opacity:1%22 id=%22path5585%22/><path d=%22M 12,33.5 C 18,32.5 27,32.5 33,33.5%22 style=%22fill:none;fill-opacity:0.75;fill-rule:evenodd;stroke:%23ffffff;stroke-width:1px;stroke-linecap:round;stroke-linejoin:round;stroke-opacity:1%22 id=%22path5587%22/><path d=%22M 10.5,36 C 15.5,35 29,35 34,36%22 style=%22fill:none;fill-opacity:0.75;fill-rule:evenodd;stroke:%23ffffff;stroke-width:1px;stroke-linecap:round;stroke-linejoin:round;stroke-opacity:1%22 id=%22path5589%22/></g></svg>',
2507 'bR': 'data:image/svg+xml,<?xml version=%221.0%22 encoding=%22UTF-8%22 standalone=%22no%22?>%0A<!DOCTYPE svg PUBLIC %22-//W3C//DTD SVG 1.1//EN%22 %22http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd%22>%0A<svg xmlns=%22http://www.w3.org/2000/svg%22 version=%221.1%22 width=%2245%22 height=%2245%22><g style=%22opacity:1;fill:%23000000;fill-opacity:1;fill-rule:evenodd;stroke:%23000000;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22 transform=%22translate(0,0.3)%22><path d=%22M 9,39 L 36,39 L 36,36 L 9,36 L 9,39 z %22 style=%22stroke-linecap:butt%22/><path d=%22M 12.5,32 L 14,29.5 L 31,29.5 L 32.5,32 L 12.5,32 z %22 style=%22stroke-linecap:butt%22/><path d=%22M 12,36 L 12,32 L 33,32 L 33,36 L 12,36 z %22 style=%22stroke-linecap:butt%22/><path d=%22M 14,29.5 L 14,16.5 L 31,16.5 L 31,29.5 L 14,29.5 z %22 style=%22stroke-linecap:butt;stroke-linejoin:miter%22/><path d=%22M 14,16.5 L 11,14 L 34,14 L 31,16.5 L 14,16.5 z %22 style=%22stroke-linecap:butt%22/><path d=%22M 11,14 L 11,9 L 15,9 L 15,11 L 20,11 L 20,9 L 25,9 L 25,11 L 30,11 L 30,9 L 34,9 L 34,14 L 11,14 z %22 style=%22stroke-linecap:butt%22/><path d=%22M 12,35.5 L 33,35.5 L 33,35.5%22 style=%22fill:none;stroke:%23ffffff;stroke-width:1;stroke-linejoin:miter%22/><path d=%22M 13,31.5 L 32,31.5%22 style=%22fill:none;stroke:%23ffffff;stroke-width:1;stroke-linejoin:miter%22/><path d=%22M 14,29.5 L 31,29.5%22 style=%22fill:none;stroke:%23ffffff;stroke-width:1;stroke-linejoin:miter%22/><path d=%22M 14,16.5 L 31,16.5%22 style=%22fill:none;stroke:%23ffffff;stroke-width:1;stroke-linejoin:miter%22/><path d=%22M 11,14 L 34,14%22 style=%22fill:none;stroke:%23ffffff;stroke-width:1;stroke-linejoin:miter%22/></g></svg>',
2508 'bB': 'data:image/svg+xml,<?xml version=%221.0%22 encoding=%22UTF-8%22 standalone=%22no%22?>%0A<!DOCTYPE svg PUBLIC %22-//W3C//DTD SVG 1.1//EN%22 %22http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd%22>%0A<svg xmlns=%22http://www.w3.org/2000/svg%22 version=%221.1%22 width=%2245%22 height=%2245%22><g style=%22opacity:1;fill:none;fill-rule:evenodd;fill-opacity:1;stroke:%23000000;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22 transform=%22translate(0,0.6)%22><g style=%22fill:%23000000;stroke:%23000000;stroke-linecap:butt%22><path d=%22M 9,36 C 12.39,35.03 19.11,36.43 22.5,34 C 25.89,36.43 32.61,35.03 36,36 C 36,36 37.65,36.54 39,38 C 38.32,38.97 37.35,38.99 36,38.5 C 32.61,37.53 25.89,38.96 22.5,37.5 C 19.11,38.96 12.39,37.53 9,38.5 C 7.65,38.99 6.68,38.97 6,38 C 7.35,36.54 9,36 9,36 z%22/><path d=%22M 15,32 C 17.5,34.5 27.5,34.5 30,32 C 30.5,30.5 30,30 30,30 C 30,27.5 27.5,26 27.5,26 C 33,24.5 33.5,14.5 22.5,10.5 C 11.5,14.5 12,24.5 17.5,26 C 17.5,26 15,27.5 15,30 C 15,30 14.5,30.5 15,32 z%22/><path d=%22M 25 8 A 2.5 2.5 0 1 1 20,8 A 2.5 2.5 0 1 1 25 8 z%22/></g><path d=%22M 17.5,26 L 27.5,26 M 15,30 L 30,30 M 22.5,15.5 L 22.5,20.5 M 20,18 L 25,18%22 style=%22fill:none;stroke:%23ffffff;stroke-linejoin:miter%22/></g></svg>',
2509 'bN': 'data:image/svg+xml,<?xml version=%221.0%22 encoding=%22UTF-8%22 standalone=%22no%22?>%0A<!DOCTYPE svg PUBLIC %22-//W3C//DTD SVG 1.1//EN%22 %22http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd%22>%0A<svg xmlns=%22http://www.w3.org/2000/svg%22 version=%221.1%22 width=%2245%22 height=%2245%22><g style=%22opacity:1;fill:none;fill-opacity:1;fill-rule:evenodd;stroke:%23000000;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22 transform=%22translate(0,0.3)%22><path d=%22M 22,10 C 32.5,11 38.5,18 38,39 L 15,39 C 15,30 25,32.5 23,18%22 style=%22fill:%23000000;stroke:%23000000%22/><path d=%22M 24,18 C 24.38,20.91 18.45,25.37 16,27 C 13,29 13.18,31.34 11,31 C 9.958,30.06 12.41,27.96 11,28 C 10,28 11.19,29.23 10,30 C 9,30 5.997,31 6,26 C 6,24 12,14 12,14 C 12,14 13.89,12.1 14,10.5 C 13.27,9.506 13.5,8.5 13.5,7.5 C 14.5,6.5 16.5,10 16.5,10 L 18.5,10 C 18.5,10 19.28,8.008 21,7 C 22,7 22,10 22,10%22 style=%22fill:%23000000;stroke:%23000000%22/><path d=%22M 9.5 25.5 A 0.5 0.5 0 1 1 8.5,25.5 A 0.5 0.5 0 1 1 9.5 25.5 z%22 style=%22fill:%23ffffff;stroke:%23ffffff%22/><path d=%22M 15 15.5 A 0.5 1.5 0 1 1 14,15.5 A 0.5 1.5 0 1 1 15 15.5 z%22 transform=%22matrix(0.866,0.5,-0.5,0.866,9.693,-5.173)%22 style=%22fill:%23ffffff;stroke:%23ffffff%22/><path d=%22M 24.55,10.4 L 24.1,11.85 L 24.6,12 C 27.75,13 30.25,14.49 32.5,18.75 C 34.75,23.01 35.75,29.06 35.25,39 L 35.2,39.5 L 37.45,39.5 L 37.5,39 C 38,28.94 36.62,22.15 34.25,17.66 C 31.88,13.17 28.46,11.02 25.06,10.5 L 24.55,10.4 z %22 style=%22fill:%23ffffff;stroke:none%22/></g></svg>',
2510 'bP': 'data:image/svg+xml,<?xml version=%221.0%22 encoding=%22UTF-8%22 standalone=%22no%22?>%0A<!DOCTYPE svg PUBLIC %22-//W3C//DTD SVG 1.1//EN%22 %22http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd%22>%0A<svg xmlns=%22http://www.w3.org/2000/svg%22 version=%221.1%22 width=%2245%22 height=%2245%22><path d=%22m 22.5,9 c -2.21,0 -4,1.79 -4,4 0,0.89 0.29,1.71 0.78,2.38 C 17.33,16.5 16,18.59 16,21 c 0,2.03 0.94,3.84 2.41,5.03 C 15.41,27.09 11,31.58 11,39.5 H 34 C 34,31.58 29.59,27.09 26.59,26.03 28.06,24.84 29,23.03 29,21 29,18.59 27.67,16.5 25.72,15.38 26.21,14.71 26.5,13.89 26.5,13 c 0,-2.21 -1.79,-4 -4,-4 z%22 style=%22opacity:1;fill:%23000000;fill-opacity:1;fill-rule:nonzero;stroke:%23000000;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1%22/></svg>',
2513 function svg_piece_theme(piece) {
2514 return svg_pieces[piece];
2518 unique = get_unique();
2520 // Load settings from HTML5 local storage if available.
2521 if (supports_html5_storage() && window['localStorage']['enable_sound']) {
2522 set_sound(parseInt(window['localStorage']['enable_sound']));
2527 let admin_match = window.location.href.match(/\?password=([a-zA-Z0-9_-]+)/);
2528 if (admin_match !== null) {
2529 admin_password = admin_match[1];
2533 board = new window.ChessBoard('board', {
2534 onMoveEnd: function() { board_is_animating = false; },
2537 pieceTheme: svg_piece_theme,
2538 onDragStart: onDragStart,
2540 onSnapEnd: onSnapEnd
2542 document.getElementById("board").addEventListener('mousedown', mousedownSquare);
2543 document.getElementById("board").addEventListener('mouseup', mouseupSquare);
2545 if (window['inline_json']) {
2546 let j = window['inline_json'];
2547 process_update_response(j['data'], { 'get': (h) => j['headers'][h] });
2548 delete window['inline_json'];
2551 window.addEventListener('resize', function() {
2553 update_sparkline(displayed_analysis_data || current_analysis_data);
2554 update_board_highlight();
2557 new ResizeObserver(() => update_sparkline(displayed_analysis_data || current_analysis_data)).observe(document.getElementById('scoresparkcontainer'));
2558 window.addEventListener('keyup', function(event) {
2559 if (event.which == 39) { // Left arrow.
2561 } else if (event.which == 37) { // Right arrow.
2563 } else if (event.which >= 49 && event.which <= 57) { // 1-9.
2564 let num = event.which - 49;
2565 if (current_games && current_games.length >= num) {
2566 switch_backend(current_games[num]);
2568 } else if (event.which == 78) { // N.
2572 window.addEventListener('hashchange', possibly_switch_game_from_hash, false);
2573 possibly_switch_game_from_hash();
2575 document.addEventListener('DOMContentLoaded', init);