/*
* 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_OT_LAYOUT_OPEN_PRIVATE_H
#define HB_OT_LAYOUT_OPEN_PRIVATE_H
#ifndef HB_OT_LAYOUT_CC
#error "This file should only be included from hb-ot-layout.cc"
#endif
#include "hb-ot-layout-private.h"
#define NO_INDEX ((unsigned int) 0xFFFF)
#define NO_CONTEXT ((unsigned int) 0x110000)
#define NOT_COVERED ((unsigned int) 0x110000)
#define MAX_NESTING_LEVEL 8
/*
* Array types
*/
/* get_len() is a method returning the number of items in an array-like object */
#define DEFINE_LEN(Type, array, num) \
inline unsigned int get_len(void) const { return num; } \
/* An array type is one that contains a variable number of objects
* as its last item. An array object is extended with get_len()
* methods, as well as overloaded [] operator. */
#define DEFINE_ARRAY_TYPE(Type, array, num) \
DEFINE_INDEX_OPERATOR(Type, array, num) \
DEFINE_LEN(Type, array, num)
#define DEFINE_INDEX_OPERATOR(Type, array, num) \
inline const Type& operator[] (unsigned int i) const \
{ \
if (HB_UNLIKELY (i >= num)) return Null(Type); \
return array[i]; \
}
/* An offset array type is like an array type, but it contains a table
* of offsets to the objects, relative to the beginning of the current
* object. */
#define DEFINE_OFFSET_ARRAY_TYPE(Type, array, num) \
DEFINE_OFFSET_INDEX_OPERATOR(Type, array, num) \
DEFINE_LEN(Offset, array, num)
#define DEFINE_OFFSET_INDEX_OPERATOR(Type, array, num) \
inline const Type& operator[] (unsigned int i) const \
{ \
if (HB_UNLIKELY (i >= num)) return Null(Type); \
if (HB_UNLIKELY (!array[i])) return Null(Type); \
return *(const Type)((const char*)this + array[i]); \
}
#define DEFINE_ARRAY_INTERFACE(Type, name) \
inline const Type& get_##name (unsigned int i) const { return (*this)[i]; } \
inline unsigned int get_##name##_count (void) const { return this->get_len (); }
#define DEFINE_INDEX_ARRAY_INTERFACE(name) \
inline unsigned int get_##name##_index (unsigned int i) const \
{ \
if (HB_UNLIKELY (i >= get_len ())) return NO_INDEX; \
return (*this)[i]; \
} \
inline unsigned int get_##name##_count (void) const { return get_len (); }
/*
* List types
*/
#define DEFINE_LIST_INTERFACE(Type, name) \
inline const Type& get_##name (unsigned int i) const { return (this+name##List)[i]; } \
inline unsigned int get_##name##_count (void) const { return (this+name##List).len; }
/*
* Tag types
*/
#define DEFINE_TAG_ARRAY_INTERFACE(Type, name) \
DEFINE_ARRAY_INTERFACE (Type, name); \
inline const Tag& get_##name##_tag (unsigned int i) const { return (*this)[i].tag; }
#define DEFINE_TAG_LIST_INTERFACE(Type, name) \
DEFINE_LIST_INTERFACE (Type, name); \
inline const Tag& get_##name##_tag (unsigned int i) const { return (this+name##List).get_tag (i); }
#define DEFINE_TAG_FIND_INTERFACE(Type, name) \
inline bool find_##name##_index (hb_tag_t tag, unsigned int *index) const { \
const Tag t = tag; \
for (unsigned int i = 0; i < get_##name##_count (); i++) \
{ \
if (t == get_##name##_tag (i)) \
{ \
if (index) *index = i; \
return true; \
} \
} \
if (index) *index = NO_INDEX; \
return false; \
} \
inline const Type& get_##name##_by_tag (hb_tag_t tag) const \
{ \
unsigned int i; \
if (find_##name##_index (tag, &i)) \
return get_##name (i); \
else \
return Null(Type); \
}
/*
* Class features
*/
/* Null objects */
/* Global nul-content Null pool. Enlarge as necessary. */
static const char NullPool[16] = "";
/* Generic template for nul-content sizeof-sized Null objects. */
template <typename Type>
struct Null
{
ASSERT_STATIC (sizeof (Type) <= sizeof (NullPool));
static inline const Type &get () { return *(const Type*)NullPool; }
};
/* Specializaiton for arbitrary-content arbitrary-sized Null objects. */
#define DEFINE_NULL_DATA(Type, size, data) \
static const char _Null##Type[size] = data; \
template <> \
struct Null <Type> \
{ \
static inline const Type &get () { return *(const Type*)_Null##Type; } \
}
/* Accessor macro. */
#define Null(Type) (Null<Type>::get())
#define ASSERT_SIZE_DATA(Type, size, data) \
ASSERT_SIZE (Type, size); \
DEFINE_NULL_DATA (Type, size, data)
/* get_for_data() is a static class method returning a reference to an
* instance of Type located at the input data location. It's just a
* fancy, NULL-safe, cast! */
#define STATIC_DEFINE_GET_FOR_DATA(Type) \
static inline const Type& get_for_data (const char *data) \
{ \
if (HB_UNLIKELY (data == NULL)) return Null(Type); \
return *(const Type*)data; \
}
/* Like get_for_data(), but checks major version first. */
#define STATIC_DEFINE_GET_FOR_DATA_CHECK_MAJOR_VERSION(Type, Major) \
static inline const Type& get_for_data (const char *data) \
{ \
if (HB_UNLIKELY (data == NULL)) return Null(Type); \
const Type& t = *(const Type*)data; \
if (HB_UNLIKELY (!t.version.major || t.version.major > Major)) return Null(Type); \
return t; \
}
/*
*
* The OpenType Font File
*
*/
/*
* Data Types
*/
/* "The following data types are used in the OpenType font file.
* All OpenType fonts use Motorola-style byte ordering (Big Endian):" */
/*
* Int types
*/
/* TODO On machines that do not allow unaligned access, fix the accessors. */
#define DEFINE_INT_TYPE1(NAME, TYPE, BIG_ENDIAN, BYTES) \
struct NAME \
{ \
inline NAME& operator = (TYPE i) { (TYPE&) v = BIG_ENDIAN (i); return *this; } \
inline operator TYPE(void) const { return BIG_ENDIAN ((TYPE&) v); } \
inline bool operator== (NAME o) const { return (TYPE&) v == (TYPE&) o.v; } \
private: char v[BYTES]; \
}; \
ASSERT_SIZE (NAME, BYTES)
#define DEFINE_INT_TYPE0(NAME, type, b) DEFINE_INT_TYPE1 (NAME, type, hb_be_##type, b)
#define DEFINE_INT_TYPE(NAME, u, w) DEFINE_INT_TYPE0 (NAME, u##int##w##_t, (w / 8))
DEFINE_INT_TYPE (USHORT, u, 16); /* 16-bit unsigned integer. */
DEFINE_INT_TYPE (SHORT, , 16); /* 16-bit signed integer. */
DEFINE_INT_TYPE (ULONG, u, 32); /* 32-bit unsigned integer. */
DEFINE_INT_TYPE (LONG, , 32); /* 32-bit signed integer. */
/* Array of four uint8s (length = 32 bits) used to identify a script, language
* system, feature, or baseline */
struct Tag : ULONG
{
inline Tag (const Tag &o) { *(ULONG*)this = (ULONG&) o; }
inline Tag (uint32_t i) { *(ULONG*)this = i; }
inline Tag (const char *c) { *(ULONG*)this = *(ULONG*)c; }
inline bool operator== (const char *c) const { return *(ULONG*)this == *(ULONG*)c; }
/* What the char* converters return is NOT nul-terminated. Print using "%.4s" */
inline operator const char* (void) const { return (const char *)this; }
inline operator char* (void) { return (char *)this; }
};
ASSERT_SIZE (Tag, 4);
#define _NULL_TAG_INIT {' ', ' ', ' ', ' '}
DEFINE_NULL_DATA (Tag, 4, _NULL_TAG_INIT);
#undef _NULL_TAG_INIT
/* Glyph index number, same as uint16 (length = 16 bits) */
typedef USHORT GlyphID;
/* Offset to a table, same as uint16 (length = 16 bits), Null offset = 0x0000 */
typedef USHORT Offset;
/* LongOffset to a table, same as uint32 (length = 32 bits), Null offset = 0x00000000 */
typedef ULONG LongOffset;
/* Template subclasses of Offset and LongOffset that do the dereferencing. Use: (this+memberName) */
template <typename Type>
struct OffsetTo : Offset
{
inline const Type& operator() (const void *base) const
{
unsigned int offset = *this;
if (HB_UNLIKELY (!offset)) return Null(Type);
return *(const Type*)((const char *) base + offset);
}
};
template <typename Base, typename Type>
inline const Type& operator + (const Base &base, OffsetTo<Type> offset) { return offset (base); }
template <typename Type>
struct LongOffsetTo : LongOffset
{
inline const Type& operator() (const void *base) const
{
unsigned int offset = *this;
if (HB_UNLIKELY (!offset)) return Null(Type);
return *(const Type*)((const char *) base + offset);
}
};
template <typename Base, typename Type>
inline const Type& operator + (const Base &base, LongOffsetTo<Type> offset) { return offset (base); }
/* CheckSum */
struct CheckSum : ULONG
{
static uint32_t CalcTableChecksum (ULONG *Table, uint32_t Length)
{
uint32_t Sum = 0L;
ULONG *EndPtr = Table+((Length+3) & ~3) / sizeof(ULONG);
while (Table < EndPtr)
Sum += *Table++;
return Sum;
}
};
ASSERT_SIZE (CheckSum, 4);
/*
* Version Numbers
*/
struct FixedVersion
{
inline operator uint32_t (void) const { return (major << 16) + minor; }
USHORT major;
USHORT minor;
};
ASSERT_SIZE (FixedVersion, 4);
/*
* Array Types
*/
/* An array with a USHORT number of elements. */
template <typename Type>
struct ArrayOf
{
inline const Type& operator [] (unsigned int i) const
{
if (HB_UNLIKELY (i >= len)) return Null(Type);
return array[i];
}
inline unsigned int get_size () const
{ return sizeof (len) + len * sizeof (array[0]); }
USHORT len;
Type array[];
};
/* An array with a USHORT number of elements,
* starting at second element. */
template <typename Type>
struct HeadlessArrayOf
{
inline const Type& operator [] (unsigned int i) const
{
if (HB_UNLIKELY (i >= len || !i)) return Null(Type);
return array[i-1];
}
inline unsigned int get_size () const
{ return sizeof (len) + (len ? len - 1 : 0) * sizeof (array[0]); }
USHORT len;
Type array[];
};
/* An array with a ULONG number of elements. */
template <typename Type>
struct LongArrayOf
{
inline const Type& operator [] (unsigned int i) const
{
if (HB_UNLIKELY (i >= len)) return Null(Type);
return array[i];
}
inline unsigned int get_size () const
{ return sizeof (len) + len * sizeof (array[0]); }
ULONG len;
Type array[];
};
/* Array of Offset's */
template <typename Type>
struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {};
/* Array of LongOffset's */
template <typename Type>
struct LongOffsetArrayOf : ArrayOf<LongOffsetTo<Type> > {};
/* LongArray of LongOffset's */
template <typename Type>
struct LongOffsetLongArrayOf : LongArrayOf<LongOffsetTo<Type> > {};
/* An array type is one that contains a variable number of objects
* as its last item. An array object is extended with get_len()
* methods, as well as overloaded [] operator. */
#define DEFINE_ARRAY_TYPE(Type, array, num) \
DEFINE_INDEX_OPERATOR(Type, array, num) \
DEFINE_LEN(Type, array, num)
#define DEFINE_INDEX_OPERATOR(Type, array, num) \
inline const Type& operator[] (unsigned int i) const \
{ \
if (HB_UNLIKELY (i >= num)) return Null(Type); \
return array[i]; \
}
/*
* Organization of an OpenType Font
*/
struct OpenTypeFontFile;
struct OffsetTable;
struct TTCHeader;
typedef struct TableDirectory
{
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;
DEFINE_TAG_ARRAY_INTERFACE (OpenTypeTable, table); /* get_table_count(), get_table(i), get_table_tag(i) */
DEFINE_TAG_FIND_INTERFACE (OpenTypeTable, table); /* find_table_index(tag), get_table_by_tag(tag) */
private:
/* OpenTypeTables, in no particular order */
DEFINE_ARRAY_TYPE (TableDirectory, tableDir, 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. */
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, 2);
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);
unsigned int get_face_count (void) const
{
switch (tag) {
default: return 0;
case TrueTypeTag: case CFFTag: return 1;
case TTCTag: return TTCHeader::get_for_data ((const char *) this).table.len;
}
}
const OpenTypeFontFace& get_face (unsigned int i) const
{
if (HB_UNLIKELY (i >= get_face_count ())) return Null(OpenTypeFontFace);
switch (tag) {
default: /* Never happens because of the if above */
case TrueTypeTag: case CFFTag: return *(const OffsetTable*)this;
case TTCTag: return this+TTCHeader::get_for_data ((const char *) this).table[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;
}
Tag tag; /* 4-byte identifier. */
};
ASSERT_SIZE (OpenTypeFontFile, 4);
#endif /* HB_OT_LAYOUT_OPEN_PRIVATE_H */
