harfbuzz/src/hb-open-file-private.hh

258 lines
7.2 KiB
C++

/*
* Copyright © 2007,2008,2009 Red Hat, Inc.
* Copyright © 2012 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Red Hat Author(s): Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_OPEN_FILE_PRIVATE_HH
#define HB_OPEN_FILE_PRIVATE_HH
#include "hb-open-type-private.hh"
/*
*
* The OpenType Font File
*
*/
/*
* Organization of an OpenType Font
*/
struct OpenTypeFontFile;
struct OffsetTable;
struct TTCHeader;
typedef struct TableRecord
{
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
return TRACE_RETURN (c->check_struct (this));
}
Tag tag; /* 4-byte identifier. */
CheckSum checkSum; /* CheckSum for this table. */
ULONG offset; /* Offset from beginning of TrueType font
* file. */
ULONG length; /* Length of this table. */
public:
DEFINE_SIZE_STATIC (16);
} OpenTypeTable;
typedef struct OffsetTable
{
friend struct OpenTypeFontFile;
inline unsigned int get_table_count (void) const
{ return numTables; }
inline const TableRecord& get_table (unsigned int i) const
{
if (unlikely (i >= numTables)) return Null(TableRecord);
return tables[i];
}
inline bool find_table_index (hb_tag_t tag, unsigned int *table_index) const
{
Tag t;
t.set (tag);
unsigned int count = numTables;
for (unsigned int i = 0; i < count; i++)
{
if (t == tables[i].tag)
{
if (table_index) *table_index = i;
return true;
}
}
if (table_index) *table_index = Index::NOT_FOUND_INDEX;
return false;
}
inline const TableRecord& get_table_by_tag (hb_tag_t tag) const
{
unsigned int table_index;
find_table_index (tag, &table_index);
return get_table (table_index);
}
public:
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
return TRACE_RETURN (c->check_struct (this) && c->check_array (tables, TableRecord::static_size, numTables));
}
private:
Tag sfnt_version; /* '\0\001\0\00' if TrueType / 'OTTO' if CFF */
USHORT numTables; /* Number of tables. */
USHORT searchRange; /* (Maximum power of 2 <= numTables) x 16 */
USHORT entrySelector; /* Log2(maximum power of 2 <= numTables). */
USHORT rangeShift; /* NumTables x 16-searchRange. */
TableRecord tables[VAR]; /* TableRecord entries. numTables items */
public:
DEFINE_SIZE_ARRAY (12, tables);
} OpenTypeFontFace;
/*
* TrueType Collections
*/
struct TTCHeaderVersion1
{
friend struct TTCHeader;
inline unsigned int get_face_count (void) const { return table.len; }
inline const OpenTypeFontFace& get_face (unsigned int i) const { return this+table[i]; }
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
return TRACE_RETURN (table.sanitize (c, this));
}
private:
Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
FixedVersion version; /* Version of the TTC Header (1.0),
* 0x00010000 */
LongOffsetLongArrayOf<OffsetTable>
table; /* Array of offsets to the OffsetTable for each font
* from the beginning of the file */
public:
DEFINE_SIZE_ARRAY (12, table);
};
struct TTCHeader
{
friend struct OpenTypeFontFile;
private:
inline unsigned int get_face_count (void) const
{
switch (u.header.version.major) {
case 2: /* version 2 is compatible with version 1 */
case 1: return u.version1.get_face_count ();
default:return 0;
}
}
inline const OpenTypeFontFace& get_face (unsigned int i) const
{
switch (u.header.version.major) {
case 2: /* version 2 is compatible with version 1 */
case 1: return u.version1.get_face (i);
default:return Null(OpenTypeFontFace);
}
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
if (unlikely (!u.header.version.sanitize (c))) return TRACE_RETURN (false);
switch (u.header.version.major) {
case 2: /* version 2 is compatible with version 1 */
case 1: return TRACE_RETURN (u.version1.sanitize (c));
default:return TRACE_RETURN (true);
}
}
private:
union {
struct {
Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
FixedVersion version; /* Version of the TTC Header (1.0 or 2.0),
* 0x00010000 or 0x00020000 */
} header;
TTCHeaderVersion1 version1;
} u;
};
/*
* OpenType Font File
*/
struct OpenTypeFontFile
{
static const hb_tag_t CFFTag = HB_TAG ('O','T','T','O'); /* OpenType with Postscript outlines */
static const hb_tag_t TrueTypeTag = HB_TAG ( 0 , 1 , 0 , 0 ); /* OpenType with TrueType outlines */
static const hb_tag_t TTCTag = HB_TAG ('t','t','c','f'); /* TrueType Collection */
static const hb_tag_t TrueTag = HB_TAG ('t','r','u','e'); /* Obsolete Apple TrueType */
static const hb_tag_t Typ1Tag = HB_TAG ('t','y','p','1'); /* Obsolete Apple Type1 font in SFNT container */
inline hb_tag_t get_tag (void) const { return u.tag; }
inline unsigned int get_face_count (void) const
{
switch (u.tag) {
case CFFTag: /* All the non-collection tags */
case TrueTag:
case Typ1Tag:
case TrueTypeTag: return 1;
case TTCTag: return u.ttcHeader.get_face_count ();
default: return 0;
}
}
inline const OpenTypeFontFace& get_face (unsigned int i) const
{
switch (u.tag) {
/* Note: for non-collection SFNT data we ignore index. This is because
* Apple dfont container is a container of SFNT's. So each SFNT is a
* non-TTC, but the index is more than zero. */
case CFFTag: /* All the non-collection tags */
case TrueTag:
case Typ1Tag:
case TrueTypeTag: return u.fontFace;
case TTCTag: return u.ttcHeader.get_face (i);
default: return Null(OpenTypeFontFace);
}
}
inline bool sanitize (hb_sanitize_context_t *c) {
TRACE_SANITIZE ();
if (unlikely (!u.tag.sanitize (c))) return TRACE_RETURN (false);
switch (u.tag) {
case CFFTag: /* All the non-collection tags */
case TrueTag:
case Typ1Tag:
case TrueTypeTag: return TRACE_RETURN (u.fontFace.sanitize (c));
case TTCTag: return TRACE_RETURN (u.ttcHeader.sanitize (c));
default: return TRACE_RETURN (true);
}
}
private:
union {
Tag tag; /* 4-byte identifier. */
OpenTypeFontFace fontFace;
TTCHeader ttcHeader;
} u;
public:
DEFINE_SIZE_UNION (4, tag);
};
#endif /* HB_OPEN_FILE_PRIVATE_HH */