From: Steinar H. Gunderson Date: Sun, 25 Dec 2022 12:43:36 +0000 (+0100) Subject: chess.js: Skip legality checking during disambiguation if not needed. X-Git-Url: https://git.sesse.net/?a=commitdiff_plain;h=1770f13ae85fae334e7f680e244ad531970a514e;hp=ed195fa00ccd9cceb58184d2a9e332d52fed26ad;p=remoteglot chess.js: Skip legality checking during disambiguation if not needed. --- diff --git a/www/js/chess.js b/www/js/chess.js index af27558..91f6c1d 100644 --- a/www/js/chess.js +++ b/www/js/chess.js @@ -1120,7 +1120,14 @@ var Chess = function(fen) { return ''; } - let moves = find_attacking_moves(move.to, piece, move.color, sloppy); + let moves = find_attacking_moves(move.to, piece, move.color); + if (moves.length <= 1) { + // There can be no ambiguity, so don't bother checking legality + // (we assume the move has already been found legal). + return ''; + } + + moves = possibly_filter_moves(moves, move.color, !sloppy); var ambiguities = 0; var same_rank = 0; @@ -1169,11 +1176,12 @@ var Chess = function(fen) { return ''; } - // Find all moves featuring the given piece attacking the given square - // (using symmetry of all non-pawn-or-castle moves, we simply generate - // moves backwards). Does not support kings or pawns. Assumes there's - // not already a piece of our own color on the destination square. - function find_attacking_moves(to, piece, us, sloppy) { + // Find all pseudolegal moves featuring the given piece attacking + // the given square (using symmetry of all non-pawn-or-castle moves, + // we simply generate // moves backwards). Does not support kings + // or pawns. Assumes there's // not already a piece of our own color + // on the destination square. + function find_attacking_moves(to, piece, us) { let moves = []; function add_move(board, moves, from, to, flags, rook_sq) { @@ -1201,7 +1209,7 @@ var Chess = function(fen) { } } - return possibly_filter_moves(moves, us, !sloppy); + return moves; } function ascii() {