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

221 lines
6.5 KiB
C++

/*
* Copyright (C) 2007,2008,2009 Red Hat, Inc.
*
* This is part of HarfBuzz, an OpenType Layout engine 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
*/
#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 TableDirectory
{
inline bool sanitize (SANITIZE_ARG_DEF, const void *base) {
TRACE_SANITIZE ();
return SANITIZE_SELF () && SANITIZE (tag) &&
SANITIZE_MEM (CONST_CHARP(base) + (unsigned long) offset, length);
}
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. */
} OpenTypeTable;
ASSERT_SIZE (TableDirectory, 16);
typedef struct OffsetTable
{
friend struct OpenTypeFontFile;
friend struct TTCHeader;
STATIC_DEFINE_GET_FOR_DATA (OffsetTable);
inline unsigned int get_table_count (void) const
{ return numTables; }
inline const Tag& get_table_tag (unsigned int i) const
{
if (HB_UNLIKELY (i >= numTables)) return Null(Tag);
return tableDir[i].tag;
}
inline const TableDirectory& get_table (unsigned int i) const
{
if (HB_UNLIKELY (i >= numTables)) return Null(TableDirectory);
return tableDir[i];
}
inline bool find_table_index (hb_tag_t tag, unsigned int *table_index) const
{
const Tag t = tag;
// TODO bsearch
unsigned int count = numTables;
for (unsigned int i = 0; i < count; i++)
{
if (t == tableDir[i].tag)
{
if (table_index) *table_index = i;
return true;
}
}
if (table_index) *table_index = NO_INDEX;
return false;
}
inline const TableDirectory& get_table_by_tag (hb_tag_t tag) const
{
unsigned int table_index;
find_table_index (tag, &table_index);
return get_table (table_index);
}
inline unsigned int get_face_count (void) const { return 1; }
public:
inline bool sanitize (SANITIZE_ARG_DEF, const void *base) {
TRACE_SANITIZE ();
if (!(SANITIZE_SELF () && SANITIZE_MEM (tableDir, sizeof (tableDir[0]) * numTables))) return false;
unsigned int count = numTables;
for (unsigned int i = 0; i < count; i++)
if (!SANITIZE_BASE (tableDir[i], base))
return false;
return true;
}
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. */
TableDirectory tableDir[]; /* TableDirectory entries. numTables items */
} OpenTypeFontFace;
ASSERT_SIZE (OffsetTable, 12);
/*
* TrueType Collections
*/
struct TTCHeader
{
friend struct OpenTypeFontFile;
STATIC_DEFINE_GET_FOR_DATA_CHECK_MAJOR_VERSION (TTCHeader, 1, 2);
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 (SANITIZE_ARG_DEF) {
TRACE_SANITIZE ();
if (!SANITIZE (version)) return false;
if (version.major < 1 || version.major > 2) return true;
/* TODO Maybe we shouldn't NEUTER these offsets, they may cause a full copy
* of the whole font right now. */
return table.sanitize (SANITIZE_ARG, CONST_CHARP(this), CONST_CHARP(this));
}
private:
Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
FixedVersion version; /* Version of the TTC Header (1.0 or 2.0),
* 0x00010000 or 0x00020000 */
LongOffsetLongArrayOf<OffsetTable>
table; /* Array of offsets to the OffsetTable for each font
* from the beginning of the file */
};
ASSERT_SIZE (TTCHeader, 12);
/*
* OpenType Font File
*/
struct OpenTypeFontFile
{
static const hb_tag_t TrueTypeTag = HB_TAG ( 0 , 1 , 0 , 0 );
static const hb_tag_t CFFTag = HB_TAG ('O','T','T','O');
static const hb_tag_t TTCTag = HB_TAG ('t','t','c','f');
STATIC_DEFINE_GET_FOR_DATA (OpenTypeFontFile);
inline unsigned int get_face_count (void) const
{
switch (tag) {
default: return 0;
case TrueTypeTag: case CFFTag: return OffsetTable::get_for_data (CONST_CHARP(this)).get_face_count ();
case TTCTag: return TTCHeader::get_for_data (CONST_CHARP(this)).get_face_count ();
}
}
inline const OpenTypeFontFace& get_face (unsigned int i) const
{
switch (tag) {
default: return Null(OpenTypeFontFace);
/* 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 TrueTypeTag: case CFFTag: return OffsetTable::get_for_data (CONST_CHARP(this));
case TTCTag: return TTCHeader::get_for_data (CONST_CHARP(this)).get_face (i);
}
}
/* This is how you get a table */
inline const char* get_table_data (const OpenTypeTable& table) const
{
if (HB_UNLIKELY (table.offset == 0)) return NULL;
return ((const char*) this) + table.offset;
}
inline bool sanitize (SANITIZE_ARG_DEF) {
TRACE_SANITIZE ();
if (!SANITIZE_SELF ()) return false;
switch (tag) {
default: return true;
case TrueTypeTag: case CFFTag: return SANITIZE_THIS (CAST (OffsetTable, *this, 0));
case TTCTag: return SANITIZE (CAST (TTCHeader, *this, 0));
}
}
Tag tag; /* 4-byte identifier. */
};
ASSERT_SIZE (OpenTypeFontFile, 4);
#endif /* HB_OPEN_FILE_PRIVATE_HH */