ref: effa96496e7f103678b3ae93089b7ae1afdec59a
dir: /src/sfnt/ttcmap0.c/
/***************************************************************************/
/* */
/* ttcmap.c */
/* */
/* TrueType character mapping table (cmap) support (body). */
/* */
/* Copyright 1996-2001 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, index;
p = table + 6;
for ( n = 0; n < 256; n++ )
{
index = *p++;
if ( index >= 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( FT_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 along the following lines: *****/
/***** *****/
/***** * certain byte values correspond to an 8-bit character code *****/
/***** (typicall 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 function 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 index = TT_NEXT_USHORT(p);
/* value must be multiple of 8 */
if ( valid->level >= FT_VALIDATE_PARANOID && ( index & 7 ) != 0 )
FT_INVALID_DATA;
index >>= 3;
if ( index > max_subs )
max_subs = index;
}
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 index;
for ( ; p < limit; )
{
index = TT_NEXT_USHORT(p);
if ( index != 0 )
{
index = (index + delta) & 0xFFFFU;
if ( index >= 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 < 0x10000 )
{
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 wheteher 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 index = (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);
index -= start;
if ( index < count && offset != 0 )
{
p += offset + 2*index;
index = TT_PEEK_USHORT(p);
if ( index != 0 )
result = (FT_UInt)( index + 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 < 0x10000U )
{
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, index;
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++ )
{
index = TT_NEXT_USHORT(p);
if ( index != 0 )
{
gindex = ( index + 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( FT_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 0
*
* glyphIds 16+NUM_SEGS*8 USHORT[] array og glyph id ranges
*
*
* Charcodes 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 over-lapping
* and the last segment should always contain the '0xFFFF' endCount.
*
* The fields 'searchRange', 'entrySelector' and 'rangeShift' are better
* ignored (they're traces of over-engineering in the TT 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, then 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..
*/
#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;
if ( table + length > valid->limit || length < 16 )
FT_INVALID_TOO_SHORT;
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 ( end > start )
FT_INVALID_DATA;
if ( n > 0 && start <= last )
FT_INVALID_DATA;
if ( offset )
{
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 index;
for ( ; start < end; )
{
index = FT_NEXT_USHORT(p);
if ( index != 0 )
{
index = (FT_UInt)(index + delta) & 0xFFFFU;
if ( index >= TT_VALID_GLYPH_COUNT(valid) )
FT_INVALID_GLYPH_ID;
}
}
}
}
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 < 0x10000U )
{
FT_Byte* p;
FT_Byte* q;
FT_UInt index, num_segs2;
FT_Int delta;
FT_UInt n, code = (FT_UInt)char_code;
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 )
{
FT_UInt end = TT_NEXT_USHORT(p);
FT_UInt start = TT_NEXT_USHORT(q);
FT_UInt offset;
if ( code < start )
break;
if ( code <= end )
{
index = (FT_UInt)( char_code - start );
p = q + num_segs2 - 2; delta = TT_PEEK_SHORT(p);
p += num_segs2; offset = TT_PEEK_USHORT(p);
if ( offset != 0 )
{
p += offset + 2*index;
index = TT_PEEK_USHORT(p);
}
if ( index != 0 )
result = (FT_UInt)( index + delta ) & 0xFFFFU;
}
}
}
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 >= 0x10000U )
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 )
{
/* 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
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 result;
Exit:
*pchar_code = result;
return gindex;
}
FT_CALLBACK_TABLE_DEF const TT_CMap_ClassRec tt_cmap4_class_rec =
{
{
sizeof( FT_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 index = (FT_UInt)( char_code - start );
if ( index < count )
{
p += 2*index;
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 index;
if ( char_code >= 0x10000U )
goto Exit;
if ( char_code < start )
char_code = start;
index = (FT_UInt)( char_code - start );
p += 2*index;
for ( ; index < count; index++ )
{
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( FT_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 are 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. *****/
/***** *****/
/***** The 'is32' table embedded in the charmap indicates *****/
/***** wether 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 = 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_UInt *agindex )
{
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 n, start, end, start_id;
p = table + 8208;
for ( n = 0; n < num_groups++; n++ )
{
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( FT_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
* reseved 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 index = (FT_ULong)( char_code - start );
if ( index < count )
{
p += 2*index;
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 index;
if ( char_code < start )
char_code = start;
index = (FT_UInt32)( char_code - start );
p += 2*index;
for ( ; index < count; index++ )
{
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( FT_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
* reseved 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 = 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 n, start, end, start_id;
p = table + 8208;
for ( n = 0; n < num_groups++; n++ )
{
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 */
#ifdef FT_CONFIG_OPTION_USE_CMAPS
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_Build_CMaps( TT_Face face )
{
TT_CMap_Class clazz;
FT_ValidatorRec valid;
FT_UInt num_cmaps;
FT_Byte* table = face->cmap_table;
FT_Byte* limit = table + face->cmap_size;
FT_Byte* p = table;
FT_UInt format;
if ( p + 4 < limit )
return FT_Err_Invalid_Table;
/* only recognize format 0 */
if ( TT_NEXT_USHORT(p) != 0 )
{
p -= 2;
FT_ERROR(( "%s: unsupported 'cmap' table format = %d\n",
"TT_Build_CMaps", 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);
offset = TT_NEXT_ULONG(p);
if ( offset && table + offset + 2 < limit )
{
FT_Byte* cmap = table + offset;
FT_UInt format = TT_PEEK_USHORT(cmap);
TT_CMap_Class* pclazz = tt_cmap_classes;
TT_CMap_Class clazz;
for ( ; *pclazz; pclazz++ )
{
clazz = *pclazz;
if ( clazz->format == format )
{
volatile TT_Validator valid;
valid.num_glyphs = face->root.num_glyphs;
if ( ft_validator_init( FT_VALIDATOR(&valid), cmap, limit,
FT_VALIDATE_LEVEL_DEFAULT ) == 0 )
{
/* validate this cmap sub-table */
clazz->validate( cmap, FT_VALIDATOR(&valid) );
}
if ( valid.error == 0 )
(void)FT_CMap_New( clazz, cmap, face, NULL );
else
FT_ERROR(( "%s: broken cmap sub-table ignored !!\n",
"TT_Build_CMaps" ));
}
}
}
}
return 0;
}
#else /* !FT_CONFIG_OPTION_USE_CMAPS */
FT_LOCAL_DEF( FT_Error )
TT_Build_CMaps( TT_Face face )
{
FT_ERROR(( "TT_Build_CMaps should _not_ be called !!\n" ));
return 0;
}
#endif /* !FT_CONFIG_OPTION_USE_CMAPS */
/* END */