From 3c5a3e45c959de4b17daecb63d3aab92a6741256 Mon Sep 17 00:00:00 2001 From: David Turner Date: Wed, 1 May 2002 08:40:32 +0000 Subject: [PATCH] * src/sfnt/ttcmap0.c (tt_cmap4_validate): fixed over-restrictive validation test. the charmap validator now accepts overlapping ranges in format 4 charmaps. * src/sfnt/ttcmap0.c (tt_cmap4_char_index): switched to a binary search algorithm. Certain fonts contain more than 170 distinct segments !! --- src/sfnt/ttcmap0.c | 128 ++++++++++++++++++++++++++++++++++----------- 1 file changed, 97 insertions(+), 31 deletions(-) diff --git a/src/sfnt/ttcmap0.c b/src/sfnt/ttcmap0.c index be318c139..b464a5b68 100644 --- a/src/sfnt/ttcmap0.c +++ b/src/sfnt/ttcmap0.c @@ -638,7 +638,7 @@ offsets = deltas + num_segs * 2; glyph_ids = offsets + num_segs * 2; - if ( glyph_ids >= table + length ) + if ( glyph_ids > table + length ) FT_INVALID_TOO_SHORT; /* check last segment, its end count must be FFFF */ @@ -670,8 +670,15 @@ if ( start > end ) FT_INVALID_DATA; - if ( n > 0 && start <= last ) - FT_INVALID_DATA; + /* this test should be performed at default validation level */ + /* unfortunately, some popular asian fonts present overlapping */ + /* ranges in their charmaps.. */ + /* */ + if ( valid->level >= FT_VALIDATE_TIGHT ) + { + if ( n > 0 && start <= last ) + FT_INVALID_DATA; + } if ( offset ) { @@ -718,49 +725,108 @@ if ( char_code < 0x10000UL ) { - FT_Byte* p; - FT_Byte* q; FT_UInt idx, num_segs2; FT_Int delta; - FT_UInt n, code = (FT_UInt)char_code; + FT_UInt code = (FT_UInt)char_code; + FT_Byte* p; p = table + 6; num_segs2 = TT_PEEK_USHORT( p ) & -2; /* be paranoid! */ - p = table + 14; /* ends table */ - q = table + 16 + num_segs2; /* starts table */ - - for ( n = 0; n < num_segs2; n += 2 ) +#if 1 + /* some fonts have more than 170 segments in their charmaps !! */ + /* we changed this function to use a more efficient binary */ + /* search to boost its performance */ { - FT_UInt end = TT_NEXT_USHORT( p ); - FT_UInt start = TT_NEXT_USHORT( q ); - FT_UInt offset; + FT_UInt min = 0; + FT_UInt max = num_segs2 >> 1; + FT_UInt mid, start, end, offset; + - - if ( code < start ) - break; - - if ( code <= end ) + while ( min < max ) { - idx = code; - - p = q + num_segs2 - 2; - delta = TT_PEEK_SHORT( p ); - p += num_segs2; - offset = TT_PEEK_USHORT( p ); - - if ( offset != 0 ) + mid = ( min + max ) >> 1; + p = table + 14 + mid*2; + end = TT_NEXT_USHORT( p ); + p += num_segs2; + start = TT_PEEK_USHORT( p); + + if ( code < start ) + max = mid; + + else if ( code > end ) + min = mid+1; + + else { - p += offset + 2 * ( idx - start ); - idx = TT_PEEK_USHORT( p ); + /* we found the segment */ + idx = code; + + p += num_segs2; + delta = TT_PEEK_SHORT( p ); + + p += num_segs2; + offset = TT_PEEK_USHORT( p ); + + if ( offset != 0 ) + { + p += offset + 2*( idx - start ); + idx = TT_PEEK_USHORT( p ); + } + + if ( idx != 0 ) + result = (FT_UInt)( idx + delta ) & 0xFFFU; + + goto Exit; } - - if ( idx != 0 ) - result = (FT_UInt)( idx + delta ) & 0xFFFFU; } } + +#else /* 0 - old code */ + { + FT_UInt n; + FT_Byte* q; + + + p = table + 14; /* ends table */ + q = table + 16 + num_segs2; /* starts table */ + + + for ( n = 0; n < num_segs2; n += 2 ) + { + FT_UInt end = TT_NEXT_USHORT( p ); + FT_UInt start = TT_NEXT_USHORT( q ); + FT_UInt offset; + + + if ( code < start ) + break; + + if ( code <= end ) + { + idx = code; + + p = q + num_segs2 - 2; + delta = TT_PEEK_SHORT( p ); + p += num_segs2; + offset = TT_PEEK_USHORT( p ); + + if ( offset != 0 ) + { + p += offset + 2 * ( idx - start ); + idx = TT_PEEK_USHORT( p ); + } + + if ( idx != 0 ) + result = (FT_UInt)( idx + delta ) & 0xFFFFU; + } + } + } +#endif /* 0 */ } + + Exit: return result; }