/* * 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 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 \ { \ static inline const Type &get () { return *(const Type*)_Null##Type; } \ } /* Accessor macro. */ #define Null(Type) (Null::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##_t, hb_be_##type, b) #define DEFINE_INT_TYPE(NAME, u, w) DEFINE_INT_TYPE0 (NAME, u##int##w, (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 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 inline const Type& operator + (const Base &base, OffsetTo offset) { return offset (base); } template 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 inline const Type& operator + (const Base &base, LongOffsetTo 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 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 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 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 struct OffsetArrayOf : ArrayOf > {}; /* Array of LongOffset's */ template struct LongOffsetArrayOf : ArrayOf > {}; /* LongArray of LongOffset's */ template struct LongOffsetLongArrayOf : LongArrayOf > {}; /* 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 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 { 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 *(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 */