ref: bd6c2aad586814b091ce5aca9d41cf2c51adb37b
dir: /libfreetype/ttcmap0.c/
/***************************************************************************/
/* */
/* ttcmap0.c */
/* */
/* TrueType new character mapping table (cmap) support (body). */
/* */
/* Copyright 2002 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
/* modified, and distributed under the terms of the FreeType project */
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
/* this file you indicate that you have read the license and */
/* understand and accept it fully. */
/* */
/***************************************************************************/
#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_OBJECTS_H
#include FT_INTERNAL_STREAM_H
#include "ttload.h"
#include "ttcmap0.h"
#include "sferrors.h"
/*************************************************************************/
/* */
/* The macro FT_COMPONENT is used in trace mode. It is an implicit */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
/* messages during execution. */
/* */
#undef FT_COMPONENT
#define FT_COMPONENT trace_ttcmap
#define TT_PEEK_SHORT FT_PEEK_SHORT
#define TT_PEEK_USHORT FT_PEEK_USHORT
#define TT_PEEK_LONG FT_PEEK_LONG
#define TT_PEEK_ULONG FT_PEEK_ULONG
#define TT_NEXT_SHORT FT_NEXT_SHORT
#define TT_NEXT_USHORT FT_NEXT_USHORT
#define TT_NEXT_LONG FT_NEXT_LONG
#define TT_NEXT_ULONG FT_NEXT_ULONG
FT_CALLBACK_DEF( FT_Error )
tt_cmap_init( TT_CMap cmap,
FT_Byte* table )
{
cmap->data = table;
return 0;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** FORMAT 0 *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* */
/* TABLE OVERVIEW */
/* -------------- */
/* */
/* NAME OFFSET TYPE DESCRIPTION */
/* */
/* format 0 USHORT must be 0 */
/* length 2 USHORT table length in bytes */
/* language 4 USHORT Mac language code */
/* glyph_ids 6 BYTE[256] array of glyph indices */
/* 262 */
/* */
#ifdef TT_CONFIG_CMAP_FORMAT_0
FT_CALLBACK_DEF( void )
tt_cmap0_validate( FT_Byte* table,
FT_Validator valid )
{
FT_Byte* p = table + 2;
FT_UInt length = TT_NEXT_USHORT( p );
if ( table + length > valid->limit || length < 262 )
FT_INVALID_TOO_SHORT;
/* check glyph indices whenever necessary */
if ( valid->level >= FT_VALIDATE_TIGHT )
{
FT_UInt n, idx;
p = table + 6;
for ( n = 0; n < 256; n++ )
{
idx = *p++;
if ( idx >= TT_VALID_GLYPH_COUNT( valid ) )
FT_INVALID_GLYPH_ID;
}
}
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap0_char_index( TT_CMap cmap,
FT_UInt32 char_code )
{
FT_Byte* table = cmap->data;
return char_code < 256 ? table[6 + char_code] : 0;
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap0_char_next( TT_CMap cmap,
FT_UInt32 *pchar_code )
{
FT_Byte* table = cmap->data;
FT_UInt32 charcode = *pchar_code;
FT_UInt32 result = 0;
FT_UInt gindex = 0;
table += 6; /* go to glyph ids */
while ( ++charcode < 256 )
{
gindex = table[charcode];
if ( gindex != 0 )
{
result = charcode;
break;
}
}
*pchar_code = result;
return gindex;
}
FT_CALLBACK_TABLE_DEF
const TT_CMap_ClassRec tt_cmap0_class_rec =
{
{
sizeof( TT_CMapRec ),
(FT_CMap_InitFunc) tt_cmap_init,
(FT_CMap_DoneFunc) NULL,
(FT_CMap_CharIndexFunc)tt_cmap0_char_index,
(FT_CMap_CharNextFunc) tt_cmap0_char_next
},
0,
(TT_CMap_ValidateFunc) tt_cmap0_validate
};
#endif /* TT_CONFIG_CMAP_FORMAT_0 */
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** FORMAT 2 *****/
/***** *****/
/***** This is used for certain CJK encodings that encode text in a *****/
/***** mixed 8/16 bits encoding along the following lines: *****/
/***** *****/
/***** * Certain byte values correspond to an 8-bit character code *****/
/***** (typically in the range 0..127 for ASCII compatibility). *****/
/***** *****/
/***** * Certain byte values signal the first byte of a 2-byte *****/
/***** character code (but these values are also valid as the *****/
/***** second byte of a 2-byte character). *****/
/***** *****/
/***** The following charmap lookup and iteration functions all *****/
/***** assume that the value "charcode" correspond to following: *****/
/***** *****/
/***** - For one byte characters, "charcode" is simply the *****/
/***** character code. *****/
/***** *****/
/***** - For two byte characters, "charcode" is the 2-byte *****/
/***** character code in big endian format. More exactly: *****/
/***** *****/
/***** (charcode >> 8) is the first byte value *****/
/***** (charcode & 0xFF) is the second byte value *****/
/***** *****/
/***** Note that not all values of "charcode" are valid according *****/
/***** to these rules, and the function moderately check the *****/
/***** arguments. *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* */
/* TABLE OVERVIEW */
/* -------------- */
/* */
/* NAME OFFSET TYPE DESCRIPTION */
/* */
/* format 0 USHORT must be 2 */
/* length 2 USHORT table length in bytes */
/* language 4 USHORT Mac language code */
/* keys 6 USHORT[256] sub-header keys */
/* subs 518 SUBHEAD[NSUBS] sub-headers array */
/* glyph_ids 518+NSUB*8 USHORT[] glyph id array */
/* */
/* The `keys' table is used to map charcode high-bytes to sub-headers. */
/* The value of `NSUBS' is the number of sub-headers defined in the */
/* table and is computed by finding the maximum of the `keys' table. */
/* */
/* Note that for any n, `keys[n]' is a byte offset within the `subs' */
/* table, i.e., it is the corresponding sub-header index multiplied */
/* by 8. */
/* */
/* Each sub-header has the following format: */
/* */
/* NAME OFFSET TYPE DESCRIPTION */
/* */
/* first 0 USHORT first valid low-byte */
/* count 2 USHORT number of valid low-bytes */
/* delta 4 SHORT see below */
/* offset 6 USHORT see below */
/* */
/* A sub-header defines, for each high-byte, the range of valid */
/* low-bytes within the charmap. Note that the range defined by `first' */
/* and `count' must be completely included in the interval [0..255] */
/* according to the specification. */
/* */
/* If a character code is contained within a given sub-header, then */
/* mapping it to a glyph index is done as follows: */
/* */
/* * The value of `offset' is read. This is a _byte_ distance from the */
/* location of the `offset' field itself into a slice of the */
/* `glyph_ids' table. Let's call it `slice' (it's a USHORT[] too). */
/* */
/* * The value `slice[char.lo - first]' is read. If it is 0, there is */
/* no glyph for the charcode. Otherwise, the value of `delta' is */
/* added to it (modulo 65536) to form a new glyph index. */
/* */
/* It is up to the validation routine to check that all offsets fall */
/* within the glyph ids table (and not within the `subs' table itself or */
/* outside of the CMap). */
/* */
#ifdef TT_CONFIG_CMAP_FORMAT_2
FT_CALLBACK_DEF( void )
tt_cmap2_validate( FT_Byte* table,
FT_Validator valid )
{
FT_Byte* p = table + 2; /* skip format */
FT_UInt length = TT_PEEK_USHORT( p );
FT_UInt n, max_subs;
FT_Byte* keys; /* keys table */
FT_Byte* subs; /* sub-headers */
FT_Byte* glyph_ids; /* glyph id array */
if ( table + length > valid->limit || length < 6 + 512 )
FT_INVALID_TOO_SHORT;
keys = table + 6;
/* parse keys to compute sub-headers count */
p = keys;
max_subs = 0;
for ( n = 0; n < 256; n++ )
{
FT_UInt idx = TT_NEXT_USHORT( p );
/* value must be multiple of 8 */
if ( valid->level >= FT_VALIDATE_PARANOID && ( idx & 7 ) != 0 )
FT_INVALID_DATA;
idx >>= 3;
if ( idx > max_subs )
max_subs = idx;
}
FT_ASSERT( p == table + 518 );
subs = p;
glyph_ids = subs + (max_subs + 1) * 8;
if ( glyph_ids > valid->limit )
FT_INVALID_TOO_SHORT;
/* parse sub-headers */
for ( n = 0; n <= max_subs; n++ )
{
FT_UInt first_code, code_count, offset;
FT_Int delta;
FT_Byte* ids;
first_code = TT_NEXT_USHORT( p );
code_count = TT_NEXT_USHORT( p );
delta = TT_NEXT_SHORT( p );
offset = TT_NEXT_USHORT( p );
/* check range within 0..255 */
if ( valid->level >= FT_VALIDATE_PARANOID )
{
if ( first_code >= 256 || first_code + code_count > 256 )
FT_INVALID_DATA;
}
/* check offset */
if ( offset != 0 )
{
ids = p - 2 + offset;
if ( ids < glyph_ids || ids + code_count*2 > table + length )
FT_INVALID_OFFSET;
/* check glyph ids */
if ( valid->level >= FT_VALIDATE_TIGHT )
{
FT_Byte* limit = p + code_count * 2;
FT_UInt idx;
for ( ; p < limit; )
{
idx = TT_NEXT_USHORT( p );
if ( idx != 0 )
{
idx = ( idx + delta ) & 0xFFFFU;
if ( idx >= TT_VALID_GLYPH_COUNT( valid ) )
FT_INVALID_GLYPH_ID;
}
}
}
}
}
}
/* return sub header corresponding to a given character code */
/* NULL on invalid charcode */
static FT_Byte*
tt_cmap2_get_subheader( FT_Byte* table,
FT_UInt32 char_code )
{
FT_Byte* result = NULL;
if ( char_code < 0x10000UL )
{
FT_UInt char_lo = (FT_UInt)( char_code & 0xFF );
FT_UInt char_hi = (FT_UInt)( char_code >> 8 );
FT_Byte* p = table + 6; /* keys table */
FT_Byte* subs = table + 518; /* subheaders table */
FT_Byte* sub;
if ( char_hi == 0 )
{
/* an 8-bit character code -- we use subHeader 0 in this case */
/* to test whether the character code is in the charmap */
/* */
sub = subs; /* jump to first sub-header */
/* check that the sub-header for this byte is 0, which */
/* indicates that it's really a valid one-byte value */
/* Otherwise, return 0 */
/* */
p += char_lo * 2;
if ( TT_PEEK_USHORT( p ) != 0 )
goto Exit;
}
else
{
/* a 16-bit character code */
p += char_hi * 2; /* jump to key entry */
sub = subs + ( TT_PEEK_USHORT( p ) & -8 ); /* jump to sub-header */
/* check that the hi byte isn't a valid one-byte value */
if ( sub == subs )
goto Exit;
}
result = sub;
}
Exit:
return result;
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap2_char_index( TT_CMap cmap,
FT_UInt32 char_code )
{
FT_Byte* table = cmap->data;
FT_UInt result = 0;
FT_Byte* subheader;
subheader = tt_cmap2_get_subheader( table, char_code );
if ( subheader )
{
FT_Byte* p = subheader;
FT_UInt idx = (FT_UInt)(char_code & 0xFF);
FT_UInt start, count;
FT_Int delta;
FT_UInt offset;
start = TT_NEXT_USHORT( p );
count = TT_NEXT_USHORT( p );
delta = TT_NEXT_SHORT ( p );
offset = TT_PEEK_USHORT( p );
idx -= start;
if ( idx < count && offset != 0 )
{
p += offset + 2 * idx;
idx = TT_PEEK_USHORT( p );
if ( idx != 0 )
result = (FT_UInt)( idx + delta ) & 0xFFFFU;
}
}
return result;
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap2_char_next( TT_CMap cmap,
FT_UInt32 *pcharcode )
{
FT_Byte* table = cmap->data;
FT_UInt gindex = 0;
FT_UInt32 result = 0;
FT_UInt32 charcode = *pcharcode + 1;
FT_Byte* subheader;
while ( charcode < 0x10000UL )
{
subheader = tt_cmap2_get_subheader( table, charcode );
if ( subheader )
{
FT_Byte* p = subheader;
FT_UInt start = TT_NEXT_USHORT( p );
FT_UInt count = TT_NEXT_USHORT( p );
FT_Int delta = TT_NEXT_SHORT ( p );
FT_UInt offset = TT_PEEK_USHORT( p );
FT_UInt char_lo = (FT_UInt)( charcode & 0xFF );
FT_UInt pos, idx;
if ( offset == 0 )
goto Next_SubHeader;
if ( char_lo < start )
{
char_lo = start;
pos = 0;
}
else
pos = (FT_UInt)( char_lo - start );
p += offset + pos * 2;
charcode = ( charcode & -256 ) + char_lo;
for ( ; pos < count; pos++, charcode++ )
{
idx = TT_NEXT_USHORT( p );
if ( idx != 0 )
{
gindex = ( idx + delta ) & 0xFFFFU;
if ( gindex != 0 )
{
result = charcode;
goto Exit;
}
}
}
}
/* jump to next sub-header, i.e. higher byte value */
Next_SubHeader:
charcode = ( charcode & -256 ) + 256;
}
Exit:
*pcharcode = result;
return gindex;
}
FT_CALLBACK_TABLE_DEF
const TT_CMap_ClassRec tt_cmap2_class_rec =
{
{
sizeof( TT_CMapRec ),
(FT_CMap_InitFunc) tt_cmap_init,
(FT_CMap_DoneFunc) NULL,
(FT_CMap_CharIndexFunc)tt_cmap2_char_index,
(FT_CMap_CharNextFunc) tt_cmap2_char_next
},
2,
(TT_CMap_ValidateFunc) tt_cmap2_validate
};
#endif /* TT_CONFIG_CMAP_FORMAT_2 */
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** FORMAT 4 *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* */
/* TABLE OVERVIEW */
/* -------------- */
/* */
/* NAME OFFSET TYPE DESCRIPTION */
/* */
/* format 0 USHORT must be 4 */
/* length 2 USHORT table length */
/* in bytes */
/* language 4 USHORT Mac language code */
/* */
/* segCountX2 6 USHORT 2*NUM_SEGS */
/* searchRange 8 USHORT 2*(1 << LOG_SEGS) */
/* entrySelector 10 USHORT LOG_SEGS */
/* rangeShift 12 USHORT segCountX2 - */
/* searchRange */
/* */
/* endCount 14 USHORT[NUM_SEGS] end charcode for */
/* each segment; last */
/* is 0xFFFF */
/* */
/* pad 14+NUM_SEGS*2 USHORT padding */
/* */
/* startCount 16+NUM_SEGS*2 USHORT[NUM_SEGS] first charcode for */
/* each segment */
/* */
/* idDelta 16+NUM_SEGS*4 SHORT[NUM_SEGS] delta for each */
/* segment */
/* idOffset 16+NUM_SEGS*6 SHORT[NUM_SEGS] range offset for */
/* each segment; can be */
/* zero */
/* */
/* glyphIds 16+NUM_SEGS*8 USHORT[] array of glyph id */
/* ranges */
/* */
/* Character codes are modelled by a series of ordered (increasing) */
/* intervals called segments. Each segment has start and end codes, */
/* provided by the `startCount' and `endCount' arrays. Segments must */
/* not be overlapping and the last segment should always contain the */
/* `0xFFFF' endCount. */
/* */
/* The fields `searchRange', `entrySelector' and `rangeShift' are better */
/* ignored (they are traces of over-engineering in the TrueType */
/* specification). */
/* */
/* Each segment also has a signed `delta', as well as an optional offset */
/* within the `glyphIds' table. */
/* */
/* If a segment's idOffset is 0, the glyph index corresponding to any */
/* charcode within the segment is obtained by adding the value of */
/* `idDelta' directly to the charcode, modulo 65536. */
/* */
/* Otherwise, a glyph index is taken from the glyph ids sub-array for */
/* the segment, and the value of `idDelta' is added to it. */
/* */
/* */
/* Finally, note that certain fonts contain invalid charmaps that */
/* contain end=0xFFFF, start=0xFFFF, delta=0x0001, offset=0xFFFF at the */
/* of their charmaps (e.g. opens___.ttf which comes with OpenOffice.org) */
/* we need special code to deal with them correctly... */
/* */
#ifdef TT_CONFIG_CMAP_FORMAT_4
FT_CALLBACK_DEF( void )
tt_cmap4_validate( FT_Byte* table,
FT_Validator valid )
{
FT_Byte* p = table + 2; /* skip format */
FT_UInt length = TT_NEXT_USHORT( p );
FT_Byte *ends, *starts, *offsets, *deltas, *glyph_ids;
FT_UInt num_segs;
/* in certain fonts, the `length' field is invalid and goes */
/* out of bound. We try to correct this here... */
if ( length < 16 )
FT_INVALID_TOO_SHORT;
if ( table + length > valid->limit )
{
if ( valid->level >= FT_VALIDATE_TIGHT )
FT_INVALID_TOO_SHORT;
length = (FT_UInt)( valid->limit - table );
}
p = table + 6;
num_segs = TT_NEXT_USHORT( p ); /* read segCountX2 */
if ( valid->level >= FT_VALIDATE_PARANOID )
{
/* check that we have an even value here */
if ( num_segs & 1 )
FT_INVALID_DATA;
}
num_segs /= 2;
/* check the search parameters - even though we never use them */
/* */
if ( valid->level >= FT_VALIDATE_PARANOID )
{
/* check the values of 'searchRange', 'entrySelector', 'rangeShift' */
FT_UInt search_range = TT_NEXT_USHORT( p );
FT_UInt entry_selector = TT_NEXT_USHORT( p );
FT_UInt range_shift = TT_NEXT_USHORT( p );
if ( ( search_range | range_shift ) & 1 ) /* must be even values */
FT_INVALID_DATA;
search_range /= 2;
range_shift /= 2;
/* `search range' is the greatest power of 2 that is <= num_segs */
if ( search_range > num_segs ||
search_range * 2 < num_segs ||
search_range + range_shift != num_segs ||
search_range != ( 1U << entry_selector ) )
FT_INVALID_DATA;
}
ends = table + 14;
starts = table + 16 + num_segs * 2;
deltas = starts + num_segs * 2;
offsets = deltas + num_segs * 2;
glyph_ids = offsets + num_segs * 2;
if ( glyph_ids > table + length )
FT_INVALID_TOO_SHORT;
/* check last segment, its end count must be FFFF */
if ( valid->level >= FT_VALIDATE_PARANOID )
{
p = ends + ( num_segs - 1 ) * 2;
if ( TT_PEEK_USHORT( p ) != 0xFFFFU )
FT_INVALID_DATA;
}
/* check that segments are sorted in increasing order and do not */
/* overlap; check also the offsets */
{
FT_UInt start, end, last = 0, offset, n;
FT_Int delta;
for ( n = 0; n < num_segs; n++ )
{
p = starts + n * 2;
start = TT_PEEK_USHORT( p );
p = ends + n * 2;
end = TT_PEEK_USHORT( p );
p = deltas + n * 2;
delta = TT_PEEK_SHORT( p );
p = offsets + n * 2;
offset = TT_PEEK_USHORT( p );
if ( start > end )
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 && offset != 0xFFFFU )
{
p += offset; /* start of glyph id array */
/* check that we point within the glyph ids table only */
if ( p < glyph_ids ||
p + ( end - start + 1 ) * 2 > table + length )
FT_INVALID_DATA;
/* check glyph indices within the segment range */
if ( valid->level >= FT_VALIDATE_TIGHT )
{
FT_UInt i, idx;
for ( i = start; i < end; i++ )
{
idx = FT_NEXT_USHORT( p );
if ( idx != 0 )
{
idx = (FT_UInt)( idx + delta ) & 0xFFFFU;
if ( idx >= TT_VALID_GLYPH_COUNT( valid ) )
FT_INVALID_GLYPH_ID;
}
}
}
}
else if ( offset == 0xFFFFU )
{
/* Some fonts (erroneously?) use a range offset of 0xFFFF */
/* to mean missing glyph in cmap table */
/* */
if ( valid->level >= FT_VALIDATE_PARANOID ||
n != num_segs - 1 ||
!( start == 0xFFFFU && end == 0xFFFFU && delta == 0x1U ) )
FT_INVALID_DATA;
}
last = end;
}
}
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap4_char_index( TT_CMap cmap,
FT_UInt32 char_code )
{
FT_Byte* table = cmap->data;
FT_UInt result = 0;
if ( char_code < 0x10000UL )
{
FT_UInt idx, num_segs2;
FT_Int delta;
FT_UInt code = (FT_UInt)char_code;
FT_Byte* p;
p = table + 6;
num_segs2 = TT_PEEK_USHORT( p ) & -2; /* be paranoid! */
#if 1
/* Some fonts have more than 170 segments in their charmaps! */
/* We changed this function to use a more efficient binary */
/* search for improving performance */
{
FT_UInt min = 0;
FT_UInt max = num_segs2 >> 1;
FT_UInt mid, start, end, offset;
while ( min < max )
{
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
{
/* we found the segment */
idx = code;
p += num_segs2;
delta = TT_PEEK_SHORT( p );
p += num_segs2;
offset = TT_PEEK_USHORT( p );
if ( offset == 0xFFFFU )
goto Exit;
if ( offset != 0 )
{
p += offset + 2 * ( idx - start );
idx = TT_PEEK_USHORT( p );
}
if ( idx != 0 )
result = (FT_UInt)( idx + delta ) & 0xFFFFU;
goto Exit;
}
}
}
#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 == 0xFFFFU )
goto Exit;
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;
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap4_char_next( TT_CMap cmap,
FT_UInt32 *pchar_code )
{
FT_Byte* table = cmap->data;
FT_UInt32 result = 0;
FT_UInt32 char_code = *pchar_code + 1;
FT_UInt gindex = 0;
FT_Byte* p;
FT_Byte* q;
FT_UInt code, num_segs2;
if ( char_code >= 0x10000UL )
goto Exit;
code = (FT_UInt)char_code;
p = table + 6;
num_segs2 = TT_PEEK_USHORT(p) & -2; /* ensure even-ness */
for (;;)
{
FT_UInt offset, n;
FT_Int delta;
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 );
if ( code < start )
code = start;
if ( code <= end )
{
p = q + num_segs2 - 2;
delta = TT_PEEK_SHORT( p );
p += num_segs2;
offset = TT_PEEK_USHORT( p );
if ( offset != 0 && offset != 0xFFFFU )
{
/* parse the glyph ids array for non-0 index */
p += offset + ( code - start ) * 2;
while ( code <= end )
{
gindex = TT_NEXT_USHORT( p );
if ( gindex != 0 )
{
gindex = (FT_UInt)( gindex + delta ) & 0xFFFFU;
if ( gindex != 0 )
break;
}
code++;
}
}
else if ( offset == 0xFFFFU )
{
/* an offset of 0xFFFF means an empty glyph in certain fonts! */
code = end;
break;
}
else
gindex = (FT_UInt)( code + delta ) & 0xFFFFU;
if ( gindex == 0 )
break;
result = code;
goto Exit;
}
}
/* loop to next trial charcode */
if ( code >= 0xFFFFU )
break;
code++;
}
return (FT_UInt)result;
Exit:
*pchar_code = result;
return gindex;
}
FT_CALLBACK_TABLE_DEF
const TT_CMap_ClassRec tt_cmap4_class_rec =
{
{
sizeof ( TT_CMapRec ),
(FT_CMap_InitFunc) tt_cmap_init,
(FT_CMap_DoneFunc) NULL,
(FT_CMap_CharIndexFunc)tt_cmap4_char_index,
(FT_CMap_CharNextFunc) tt_cmap4_char_next
},
4,
(TT_CMap_ValidateFunc) tt_cmap4_validate
};
#endif /* TT_CONFIG_CMAP_FORMAT_4 */
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** FORMAT 6 *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* */
/* TABLE OVERVIEW */
/* -------------- */
/* */
/* NAME OFFSET TYPE DESCRIPTION */
/* */
/* format 0 USHORT must be 4 */
/* length 2 USHORT table length in bytes */
/* language 4 USHORT Mac language code */
/* */
/* first 6 USHORT first segment code */
/* count 8 USHORT segment size in chars */
/* glyphIds 10 USHORT[count] glyph ids */
/* */
/* A very simplified segment mapping. */
/* */
#ifdef TT_CONFIG_CMAP_FORMAT_6
FT_CALLBACK_DEF( void )
tt_cmap6_validate( FT_Byte* table,
FT_Validator valid )
{
FT_Byte* p;
FT_UInt length, start, count;
if ( table + 10 > valid->limit )
FT_INVALID_TOO_SHORT;
p = table + 2;
length = TT_NEXT_USHORT( p );
p = table + 6; /* skip language */
start = TT_NEXT_USHORT( p );
count = TT_NEXT_USHORT( p );
if ( table + length > valid->limit || length < 10 + count * 2 )
FT_INVALID_TOO_SHORT;
/* check glyph indices */
if ( valid->level >= FT_VALIDATE_TIGHT )
{
FT_UInt gindex;
for ( ; count > 0; count-- )
{
gindex = TT_NEXT_USHORT( p );
if ( gindex >= TT_VALID_GLYPH_COUNT( valid ) )
FT_INVALID_GLYPH_ID;
}
}
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap6_char_index( TT_CMap cmap,
FT_UInt32 char_code )
{
FT_Byte* table = cmap->data;
FT_UInt result = 0;
FT_Byte* p = table + 6;
FT_UInt start = TT_NEXT_USHORT( p );
FT_UInt count = TT_NEXT_USHORT( p );
FT_UInt idx = (FT_UInt)( char_code - start );
if ( idx < count )
{
p += 2 * idx;
result = TT_PEEK_USHORT( p );
}
return result;
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap6_char_next( TT_CMap cmap,
FT_UInt32 *pchar_code )
{
FT_Byte* table = cmap->data;
FT_UInt32 result = 0;
FT_UInt32 char_code = *pchar_code + 1;
FT_UInt gindex = 0;
FT_Byte* p = table + 6;
FT_UInt start = TT_NEXT_USHORT( p );
FT_UInt count = TT_NEXT_USHORT( p );
FT_UInt idx;
if ( char_code >= 0x10000UL )
goto Exit;
if ( char_code < start )
char_code = start;
idx = (FT_UInt)( char_code - start );
p += 2 * idx;
for ( ; idx < count; idx++ )
{
gindex = TT_NEXT_USHORT( p );
if ( gindex != 0 )
{
result = char_code;
break;
}
char_code++;
}
Exit:
*pchar_code = result;
return gindex;
}
FT_CALLBACK_TABLE_DEF
const TT_CMap_ClassRec tt_cmap6_class_rec =
{
{
sizeof ( TT_CMapRec ),
(FT_CMap_InitFunc) tt_cmap_init,
(FT_CMap_DoneFunc) NULL,
(FT_CMap_CharIndexFunc)tt_cmap6_char_index,
(FT_CMap_CharNextFunc) tt_cmap6_char_next
},
6,
(TT_CMap_ValidateFunc) tt_cmap6_validate
};
#endif /* TT_CONFIG_CMAP_FORMAT_6 */
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** FORMAT 8 *****/
/***** *****/
/***** It's hard to completely understand what the OpenType spec *****/
/***** says about this format, but here is my conclusion. *****/
/***** *****/
/***** The purpose of this format is to easily map UTF-16 text to *****/
/***** glyph indices. Basically, the `char_code' must be in one of *****/
/***** the following formats: *****/
/***** *****/
/***** - A 16-bit value that isn't part of the Unicode Surrogates *****/
/***** Area (i.e. U+D800-U+DFFF). *****/
/***** *****/
/***** - A 32-bit value, made of two surrogate values, i.e.. if *****/
/***** `char_code = (char_hi << 16) | char_lo', then both *****/
/***** `char_hi' and `char_lo' must be in the Surrogates Area. *****/
/***** Area. *****/
/***** *****/
/***** The 'is32' table embedded in the charmap indicates whether a *****/
/***** given 16-bit value is in the surrogates area or not. *****/
/***** *****/
/***** So, for any given `char_code', we can assert the following: *****/
/***** *****/
/***** If `char_hi == 0' then we must have `is32[char_lo] == 0'. *****/
/***** *****/
/***** If `char_hi != 0' then we must have both *****/
/***** `is32[char_hi] != 0' and `is32[char_lo] != 0'. *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* */
/* TABLE OVERVIEW */
/* -------------- */
/* */
/* NAME OFFSET TYPE DESCRIPTION */
/* */
/* format 0 USHORT must be 8 */
/* reseved 2 USHORT reserved */
/* length 4 ULONG length in bytes */
/* language 8 ULONG Mac language code */
/* is32 12 BYTE[8192] 32-bitness bitmap */
/* count 8204 ULONG number of groups */
/* */
/* This header is followed by 'count' groups of the following format: */
/* */
/* start 0 ULONG first charcode */
/* end 4 ULONG last charcode */
/* startId 8 ULONG start glyph id for the group */
/* */
#ifdef TT_CONFIG_CMAP_FORMAT_8
FT_CALLBACK_DEF( void )
tt_cmap8_validate( FT_Byte* table,
FT_Validator valid )
{
FT_Byte* p = table + 4;
FT_Byte* is32;
FT_UInt32 length;
FT_UInt32 num_groups;
if ( table + 16 + 8192 > valid->limit )
FT_INVALID_TOO_SHORT;
length = TT_NEXT_ULONG( p );
if ( table + length > valid->limit || length < 8208 )
FT_INVALID_TOO_SHORT;
is32 = table + 12;
p = is32 + 8192; /* skip `is32' array */
num_groups = TT_NEXT_ULONG( p );
if ( p + num_groups * 12 > valid->limit )
FT_INVALID_TOO_SHORT;
/* check groups, they must be in increasing order */
{
FT_UInt32 n, start, end, start_id, count, last = 0;
for ( n = 0; n < num_groups; n++ )
{
FT_UInt hi, lo;
start = TT_NEXT_ULONG( p );
end = TT_NEXT_ULONG( p );
start_id = TT_NEXT_ULONG( p );
if ( start > end )
FT_INVALID_DATA;
if ( n > 0 && start <= last )
FT_INVALID_DATA;
if ( valid->level >= FT_VALIDATE_TIGHT )
{
if ( start_id + end - start >= TT_VALID_GLYPH_COUNT( valid ) )
FT_INVALID_GLYPH_ID;
count = (FT_UInt32)( end - start + 1 );
if ( start & ~0xFFFFU )
{
/* start_hi != 0; check that is32[i] is 1 for each i in */
/* the `hi' and `lo' of the range [start..end] */
for ( ; count > 0; count--, start++ )
{
hi = (FT_UInt)( start >> 16 );
lo = (FT_UInt)( start & 0xFFFFU );
if ( (is32[hi >> 3] & ( 0x80 >> ( hi & 7 ) ) ) == 0 )
FT_INVALID_DATA;
if ( (is32[lo >> 3] & ( 0x80 >> ( lo & 7 ) ) ) == 0 )
FT_INVALID_DATA;
}
}
else
{
/* start_hi == 0; check that is32[i] is 0 for each i in */
/* the range [start..end] */
/* end_hi cannot be != 0! */
if ( end & ~0xFFFFU )
FT_INVALID_DATA;
for ( ; count > 0; count--, start++ )
{
lo = (FT_UInt)( start & 0xFFFFU );
if ( (is32[lo >> 3] & ( 0x80 >> ( lo & 7 ) ) ) != 0 )
FT_INVALID_DATA;
}
}
}
last = end;
}
}
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap8_char_index( TT_CMap cmap,
FT_UInt32 char_code )
{
FT_Byte* table = cmap->data;
FT_UInt result = 0;
FT_Byte* p = table + 8204;
FT_UInt32 num_groups = TT_NEXT_ULONG( p );
FT_UInt32 start, end, start_id;
for ( ; num_groups > 0; num_groups-- )
{
start = TT_NEXT_ULONG( p );
end = TT_NEXT_ULONG( p );
start_id = TT_NEXT_ULONG( p );
if ( char_code < start )
break;
if ( char_code <= end )
{
result = (FT_UInt)( start_id + char_code - start );
break;
}
}
return result;
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap8_char_next( TT_CMap cmap,
FT_UInt32 *pchar_code )
{
FT_UInt32 result = 0;
FT_UInt32 char_code = *pchar_code + 1;
FT_UInt gindex = 0;
FT_Byte* table = cmap->data;
FT_Byte* p = table + 8204;
FT_UInt32 num_groups = TT_NEXT_ULONG( p );
FT_UInt32 start, end, start_id;
p = table + 8208;
for ( ; num_groups > 0; num_groups-- )
{
start = TT_NEXT_ULONG( p );
end = TT_NEXT_ULONG( p );
start_id = TT_NEXT_ULONG( p );
if ( char_code < start )
char_code = start;
if ( char_code <= end )
{
gindex = (FT_UInt)( char_code - start + start_id );
if ( gindex != 0 )
{
result = char_code;
goto Exit;
}
}
}
Exit:
*pchar_code = result;
return gindex;
}
FT_CALLBACK_TABLE_DEF
const TT_CMap_ClassRec tt_cmap8_class_rec =
{
{
sizeof ( TT_CMapRec ),
(FT_CMap_InitFunc) tt_cmap_init,
(FT_CMap_DoneFunc) NULL,
(FT_CMap_CharIndexFunc)tt_cmap8_char_index,
(FT_CMap_CharNextFunc) tt_cmap8_char_next
},
8,
(TT_CMap_ValidateFunc) tt_cmap8_validate
};
#endif /* TT_CONFIG_CMAP_FORMAT_8 */
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** FORMAT 10 *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* */
/* TABLE OVERVIEW */
/* -------------- */
/* */
/* NAME OFFSET TYPE DESCRIPTION */
/* */
/* format 0 USHORT must be 10 */
/* reserved 2 USHORT reserved */
/* length 4 ULONG length in bytes */
/* language 8 ULONG Mac language code */
/* */
/* start 12 ULONG first char in range */
/* count 16 ULONG number of chars in range */
/* glyphIds 20 USHORT[count] glyph indices covered */
/* */
#ifdef TT_CONFIG_CMAP_FORMAT_10
FT_CALLBACK_DEF( void )
tt_cmap10_validate( FT_Byte* table,
FT_Validator valid )
{
FT_Byte* p = table + 4;
FT_ULong length, start, count;
if ( table + 20 > valid->limit )
FT_INVALID_TOO_SHORT;
length = TT_NEXT_ULONG( p );
p = table + 12;
start = TT_NEXT_ULONG( p );
count = TT_NEXT_ULONG( p );
if ( table + length > valid->limit || length < 20 + count * 2 )
FT_INVALID_TOO_SHORT;
/* check glyph indices */
if ( valid->level >= FT_VALIDATE_TIGHT )
{
FT_UInt gindex;
for ( ; count > 0; count-- )
{
gindex = TT_NEXT_USHORT( p );
if ( gindex >= TT_VALID_GLYPH_COUNT( valid ) )
FT_INVALID_GLYPH_ID;
}
}
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap10_char_index( TT_CMap cmap,
FT_UInt32 char_code )
{
FT_Byte* table = cmap->data;
FT_UInt result = 0;
FT_Byte* p = table + 12;
FT_UInt32 start = TT_NEXT_ULONG( p );
FT_UInt32 count = TT_NEXT_ULONG( p );
FT_UInt32 idx = (FT_ULong)( char_code - start );
if ( idx < count )
{
p += 2 * idx;
result = TT_PEEK_USHORT( p );
}
return result;
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap10_char_next( TT_CMap cmap,
FT_UInt32 *pchar_code )
{
FT_Byte* table = cmap->data;
FT_UInt32 result = 0;
FT_UInt32 char_code = *pchar_code + 1;
FT_UInt gindex = 0;
FT_Byte* p = table + 12;
FT_UInt32 start = TT_NEXT_ULONG( p );
FT_UInt32 count = TT_NEXT_ULONG( p );
FT_UInt32 idx;
if ( char_code < start )
char_code = start;
idx = (FT_UInt32)( char_code - start );
p += 2 * idx;
for ( ; idx < count; idx++ )
{
gindex = TT_NEXT_USHORT( p );
if ( gindex != 0 )
{
result = char_code;
break;
}
char_code++;
}
*pchar_code = char_code;
return gindex;
}
FT_CALLBACK_TABLE_DEF
const TT_CMap_ClassRec tt_cmap10_class_rec =
{
{
sizeof ( TT_CMapRec ),
(FT_CMap_InitFunc) tt_cmap_init,
(FT_CMap_DoneFunc) NULL,
(FT_CMap_CharIndexFunc)tt_cmap10_char_index,
(FT_CMap_CharNextFunc) tt_cmap10_char_next
},
10,
(TT_CMap_ValidateFunc) tt_cmap10_validate
};
#endif /* TT_CONFIG_CMAP_FORMAT_10 */
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** FORMAT 12 *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/* */
/* TABLE OVERVIEW */
/* -------------- */
/* */
/* NAME OFFSET TYPE DESCRIPTION */
/* */
/* format 0 USHORT must be 12 */
/* reserved 2 USHORT reserved */
/* length 4 ULONG length in bytes */
/* language 8 ULONG Mac language code */
/* count 12 ULONG number of groups */
/* 16 */
/* */
/* This header is followed by `count' groups of the following format: */
/* */
/* start 0 ULONG first charcode */
/* end 4 ULONG last charcode */
/* startId 8 ULONG start glyph id for the group */
/* */
#ifdef TT_CONFIG_CMAP_FORMAT_12
FT_CALLBACK_DEF( void )
tt_cmap12_validate( FT_Byte* table,
FT_Validator valid )
{
FT_Byte* p;
FT_ULong length;
FT_ULong num_groups;
if ( table + 16 > valid->limit )
FT_INVALID_TOO_SHORT;
p = table + 4;
length = TT_NEXT_ULONG( p );
p = table + 12;
num_groups = TT_NEXT_ULONG( p );
if ( table + length > valid->limit || length < 16 + 12 * num_groups )
FT_INVALID_TOO_SHORT;
/* check groups, they must be in increasing order */
{
FT_ULong n, start, end, start_id, last = 0;
for ( n = 0; n < num_groups; n++ )
{
start = TT_NEXT_ULONG( p );
end = TT_NEXT_ULONG( p );
start_id = TT_NEXT_ULONG( p );
if ( start > end )
FT_INVALID_DATA;
if ( n > 0 && start <= last )
FT_INVALID_DATA;
if ( valid->level >= FT_VALIDATE_TIGHT )
{
if ( start_id + end - start >= TT_VALID_GLYPH_COUNT( valid ) )
FT_INVALID_GLYPH_ID;
}
last = end;
}
}
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap12_char_index( TT_CMap cmap,
FT_UInt32 char_code )
{
FT_UInt result = 0;
FT_Byte* table = cmap->data;
FT_Byte* p = table + 12;
FT_UInt32 num_groups = TT_NEXT_ULONG( p );
FT_UInt32 start, end, start_id;
for ( ; num_groups > 0; num_groups-- )
{
start = TT_NEXT_ULONG( p );
end = TT_NEXT_ULONG( p );
start_id = TT_NEXT_ULONG( p );
if ( char_code < start )
break;
if ( char_code <= end )
{
result = (FT_UInt)( start_id + char_code - start );
break;
}
}
return result;
}
FT_CALLBACK_DEF( FT_UInt )
tt_cmap12_char_next( TT_CMap cmap,
FT_UInt32 *pchar_code )
{
FT_Byte* table = cmap->data;
FT_UInt32 result = 0;
FT_UInt32 char_code = *pchar_code + 1;
FT_UInt gindex = 0;
FT_Byte* p = table + 12;
FT_UInt32 num_groups = TT_NEXT_ULONG( p );
FT_UInt32 start, end, start_id;
p = table + 16;
for ( ; num_groups > 0; num_groups-- )
{
start = TT_NEXT_ULONG( p );
end = TT_NEXT_ULONG( p );
start_id = TT_NEXT_ULONG( p );
if ( char_code < start )
char_code = start;
if ( char_code <= end )
{
gindex = (FT_UInt)(char_code - start + start_id);
if ( gindex != 0 )
{
result = char_code;
goto Exit;
}
}
}
Exit:
*pchar_code = result;
return gindex;
}
FT_CALLBACK_TABLE_DEF
const TT_CMap_ClassRec tt_cmap12_class_rec =
{
{
sizeof ( TT_CMapRec ),
(FT_CMap_InitFunc) tt_cmap_init,
(FT_CMap_DoneFunc) NULL,
(FT_CMap_CharIndexFunc)tt_cmap12_char_index,
(FT_CMap_CharNextFunc) tt_cmap12_char_next
},
12,
(TT_CMap_ValidateFunc) tt_cmap12_validate
};
#endif /* TT_CONFIG_CMAP_FORMAT_12 */
static const TT_CMap_Class tt_cmap_classes[] =
{
#ifdef TT_CONFIG_CMAP_FORMAT_0
&tt_cmap0_class_rec,
#endif
#ifdef TT_CONFIG_CMAP_FORMAT_2
&tt_cmap2_class_rec,
#endif
#ifdef TT_CONFIG_CMAP_FORMAT_4
&tt_cmap4_class_rec,
#endif
#ifdef TT_CONFIG_CMAP_FORMAT_6
&tt_cmap6_class_rec,
#endif
#ifdef TT_CONFIG_CMAP_FORMAT_8
&tt_cmap8_class_rec,
#endif
#ifdef TT_CONFIG_CMAP_FORMAT_10
&tt_cmap10_class_rec,
#endif
#ifdef TT_CONFIG_CMAP_FORMAT_12
&tt_cmap12_class_rec,
#endif
NULL,
};
/* parse the `cmap' table and build the corresponding TT_CMap objects */
/* in the current face */
/* */
FT_LOCAL_DEF( FT_Error )
tt_face_build_cmaps( TT_Face face )
{
FT_Byte* table = face->cmap_table;
FT_Byte* limit = table + face->cmap_size;
FT_UInt volatile num_cmaps;
FT_Byte* volatile p = table;
if ( p + 4 > limit )
return FT_Err_Invalid_Table;
/* only recognize format 0 */
if ( TT_NEXT_USHORT( p ) != 0 )
{
p -= 2;
FT_ERROR(( "tt_face_build_cmaps: unsupported `cmap' table format = %d\n",
TT_PEEK_USHORT( p ) ));
return FT_Err_Invalid_Table;
}
num_cmaps = TT_NEXT_USHORT( p );
for ( ; num_cmaps > 0 && p + 8 <= limit; num_cmaps-- )
{
FT_CharMapRec charmap;
FT_UInt32 offset;
charmap.platform_id = TT_NEXT_USHORT( p );
charmap.encoding_id = TT_NEXT_USHORT( p );
charmap.face = FT_FACE( face );
charmap.encoding = FT_ENCODING_NONE; /* will be filled later */
offset = TT_NEXT_ULONG( p );
if ( offset && table + offset + 2 < limit )
{
FT_Byte* cmap = table + offset;
FT_UInt format = TT_PEEK_USHORT( cmap );
const TT_CMap_Class* volatile pclazz = tt_cmap_classes;
TT_CMap_Class clazz;
for ( ; *pclazz; pclazz++ )
{
clazz = *pclazz;
if ( clazz->format == format )
{
volatile TT_ValidatorRec valid;
ft_validator_init( FT_VALIDATOR( &valid ), cmap, limit,
FT_VALIDATE_DEFAULT );
valid.num_glyphs = (FT_UInt)face->root.num_glyphs;
if ( ft_setjmp( FT_VALIDATOR( &valid )->jump_buffer ) == 0 )
{
/* validate this cmap sub-table */
clazz->validate( cmap, FT_VALIDATOR( &valid ) );
}
if ( valid.validator.error == 0 )
(void)FT_CMap_New( (FT_CMap_Class)clazz, cmap, &charmap, NULL );
else
{
FT_ERROR(( "tt_face_build_cmaps:" ));
FT_ERROR(( " broken cmap sub-table ignored!\n" ));
}
}
}
}
}
return 0;
}
/* END */